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In JoVE (1)
Other Publications (169)
- Di 1 Jun Yi Da Xue Xue Bao = Academic Journal of the First Medical College of PLA
- Zhonghua Zhong Liu Za Zhi [Chinese Journal of Oncology]
- Sheng Li Ke Xue Jin Zhan [Progress in Physiology]
- Biochemical and Biophysical Research Communications
- Sheng Li Xue Bao : [Acta Physiologica Sinica]
- Journal of Neurophysiology
- Statistics in Medicine
- Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi = Chinese Journal of Cellular and Molecular Immunology
- Journal of Immunology (Baltimore, Md. : 1950)
- Statistics in Medicine
- Zhonghua Gan Zang Bing Za Zhi = Zhonghua Ganzangbing Zazhi = Chinese Journal of Hepatology
- IEEE Transactions on Neural Systems and Rehabilitation Engineering : a Publication of the IEEE Engineering in Medicine and Biology Society
- The Journal of Experimental Medicine
- Journal of Cell Science
- Zhongguo Zhong Xi Yi Jie He Za Zhi Zhongguo Zhongxiyi Jiehe Zazhi = Chinese Journal of Integrated Traditional and Western Medicine / Zhongguo Zhong Xi Yi Jie He Xue Hui, Zhongguo Zhong Yi Yan Jiu Yuan Zhu Ban
- Zhonghua Gan Zang Bing Za Zhi = Zhonghua Ganzangbing Zazhi = Chinese Journal of Hepatology
- Neuroscience Letters
- Conference Proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference
- The International Journal of Biochemistry & Cell Biology
- Cancer Research
- Experimental Cell Research
- Journal of Immunology (Baltimore, Md. : 1950)
- Liver International : Official Journal of the International Association for the Study of the Liver
- The Journal of Biological Chemistry
- Digestive Diseases and Sciences
- Clinical Biochemistry
- Biomedical Chromatography : BMC
- The American Journal of Gastroenterology
- Se Pu = Chinese Journal of Chromatography / Zhongguo Hua Xue Hui
- American Journal of Infection Control
- Journal of Clinical Virology : the Official Publication of the Pan American Society for Clinical Virology
- Journal of Pharmaceutical and Biomedical Analysis
- International Journal of Pharmaceutics
- Frontiers in Bioscience : a Journal and Virtual Library
- The Journal of Organic Chemistry
- Protein Expression and Purification
- Journal of Clinical Microbiology
- Yao Xue Xue Bao = Acta Pharmaceutica Sinica
- Nan Fang Yi Ke Da Xue Xue Bao = Journal of Southern Medical University
- The European Journal of Neuroscience
- Cellular Physiology and Biochemistry : International Journal of Experimental Cellular Physiology, Biochemistry, and Pharmacology
- Digestive Diseases and Sciences
- Biochemical Pharmacology
- Acta Crystallographica. Section E, Structure Reports Online
- DNA Sequence : the Journal of DNA Sequencing and Mapping
- Biophysical Journal
- Bioresource Technology
- Structure (London, England : 1993)
- The Journal of Pediatrics
- Journal of Structural Biology
- Journal of Virology
- The Pediatric Infectious Disease Journal
- The Journal of Neuroscience : the Official Journal of the Society for Neuroscience
- Journal of the American Chemical Society
- Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
- PloS One
- Journal of Pharmaceutical and Biomedical Analysis
- PloS One
- Pancreatology : Official Journal of the International Association of Pancreatology (IAP) ... [et Al.]
- Toxicon : Official Journal of the International Society on Toxinology
- BMC Bioinformatics
- Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi = Zhonghua Laodong Weisheng Zhiyebing Zazhi = Chinese Journal of Industrial Hygiene and Occupational Diseases
- Human Genetics
- The Annals of Thoracic Surgery
- Zhejiang Da Xue Xue Bao. Yi Xue Ban = Journal of Zhejiang University. Medical Sciences
- Human Genetics
- Journal of Structural Biology
- The Review of Scientific Instruments
- Bioresource Technology
- Journal of Nanoscience and Nanotechnology
- Hepatology Research : the Official Journal of the Japan Society of Hepatology
- Medical Science Monitor : International Medical Journal of Experimental and Clinical Research
- ACS Nano
- PloS One
- Interactive Cardiovascular and Thoracic Surgery
- Cancer Research
- Journal of Zhejiang University. Science. B
- Chemical Communications (Cambridge, England)
- Bioresource Technology
- Zhonghua Liu Xing Bing Xue Za Zhi = Zhonghua Liuxingbingxue Zazhi
- The Journal of Experimental Medicine
- Nan Fang Yi Ke Da Xue Xue Bao = Journal of Southern Medical University
- Plant Physiology
- Sheng Li Xue Bao : [Acta Physiologica Sinica]
- Tobacco Control
- Journal of Nanoscience and Nanotechnology
- Anesthesia and Analgesia
- Tobacco Control
- Molecular Plant
- Clinica Chimica Acta; International Journal of Clinical Chemistry
- The Review of Scientific Instruments
- The Journal of Physiology
- Liver International : Official Journal of the International Association for the Study of the Liver
- BMC Bioinformatics
- Lab on a Chip
- The Journal of Clinical Investigation
- ACS Applied Materials & Interfaces
- Drug Delivery
- Liver Transplantation : Official Publication of the American Association for the Study of Liver Diseases and the International Liver Transplantation Society
- American Journal of Physiology. Cell Physiology
- Journal of Medical Virology
- The Journal of Organic Chemistry
- Analytical Biochemistry
- Physical Chemistry Chemical Physics : PCCP
- Experimental Neurology
- PloS One
- International Journal of Cancer. Journal International Du Cancer
- Langmuir : the ACS Journal of Surfaces and Colloids
- Biology of the Cell / Under the Auspices of the European Cell Biology Organization
- Journal of Gastroenterology and Hepatology
- Journal of Immunology (Baltimore, Md. : 1950)
- Journal of Environmental Sciences (China)
- Bioresource Technology
- Bioresource Technology
- Nano Letters
- Bioresource Technology
- Bioresource Technology
- Bioresource Technology
- Journal of Immunology (Baltimore, Md. : 1950)
- The New Phytologist
- Statistics in Medicine
- Chemistry (Weinheim an Der Bergstrasse, Germany)
- Nano Letters
- Antonie Van Leeuwenhoek
- Organic Letters
- Chemistry (Weinheim an Der Bergstrasse, Germany)
- PloS One
- Bioresource Technology
- Bioresource Technology
- Bioresource Technology
- Bioresource Technology
- Analytical and Bioanalytical Chemistry
- Statistics in Medicine
- Radiotherapy and Oncology : Journal of the European Society for Therapeutic Radiology and Oncology
- Bioresource Technology
- Bioresource Technology
- PLoS Genetics
- Lab on a Chip
- Bioresource Technology
- The EMBO Journal
- Chemical Communications (Cambridge, England)
- Bioresource Technology
- Journal of Materials Chemistry
- Nano Letters
- The European Journal of Contraception & Reproductive Health Care : the Official Journal of the European Society of Contraception
- Journal of Nanoscience and Nanotechnology
- Zhejiang Da Xue Xue Bao. Yi Xue Ban = Journal of Zhejiang University. Medical Sciences
- Gastrointestinal Endoscopy
- Hypertension Research : Official Journal of the Japanese Society of Hypertension
- Nano Letters
- Yi Chuan = Hereditas / Zhongguo Yi Chuan Xue Hui Bian Ji
- Zhongguo Zhong Yao Za Zhi = Zhongguo Zhongyao Zazhi = China Journal of Chinese Materia Medica
- Zhonghua Bing Li Xue Za Zhi Chinese Journal of Pathology
- Zhonghua Yi Xue Za Zhi
- Journal of Neuroinflammation
- Bioresource Technology
- Small (Weinheim an Der Bergstrasse, Germany)
- Angewandte Chemie (International Ed. in English)
- Journal of Digestive Diseases
- Surgical Endoscopy
- FASEB Journal : Official Publication of the Federation of American Societies for Experimental Biology
Articles by Jian Shi in JoVE
Electron Cryotomography of Bacterial Cells
Songye Chen1, Alasdair McDowall1,2, Megan J. Dobro1, Ariane Briegel1,2, Mark Ladinsky1,2, Jian Shi2, Elitza I. Tocheva1, Morgan Beeby1,2, Martin Pilhofer1,2, H. Jane Ding1, Zhuo Li1,2, Lu Gan1, Dylan M. Morris1, Grant J. Jensen1,2
1Division of Biology, California Institute of Technology - Caltech, 2Howard Hughes Medical Institute, California Institute of Technology - Caltech
We illustrate here how to use electron cryotomography (ECT) to study the ultrastructure of bacterial cells in near-native states, to "macromolecular" (~4 nm) resolution.
Other articles by Jian Shi on PubMed
Di 1 Jun Yi Da Xue Xue Bao = Academic Journal of the First Medical College of PLA. May, 2002 | Pubmed ID: 12390710
To study the effective implementation of rehabilitation therapy for nervous system impairment in neonates with perinatal brain injury.
Zhonghua Zhong Liu Za Zhi [Chinese Journal of Oncology]. Jul, 2002 | Pubmed ID: 12408772
To evaluate the clinical effect, CT image changes and side-effects of percutaneous microwave coagulation therapy for lung cancer.
Sheng Li Ke Xue Jin Zhan [Progress in Physiology]. Oct, 2002 | Pubmed ID: 12650066
Neurotrophic factors includes nerve growth factors (NGF) family, glial cell line-derived neurotrophic factors (GDNF) family and other neurotrophic factors. NGF, BDNF, NT-3, NT-4/5 and NT-6 constitute NGF family (the neurotrophins), which may enhance both survival and differentiation of neurons from the EGF-responsive hippocampal and the subventricular zone neural stem cells. GDNF family includes GDNF, NTN, PSP and ART, whose major role is in peripheral neurodevelopment. This family enhance proliferation and survival of enteric neural crest precursor cells and is critical for the development of peripheral sensory nerve. Other growth factors such as bFGF and EGF can enhance proliferation and survival of neural stem cell. CNTF and LIF are critical for differentiation of neural stem cells.
Biochemical and Biophysical Research Communications. Jun, 2003 | Pubmed ID: 12804577
We report the isolation and characterization of two sucrose transporter cDNAs (CitSUT1 and CitSUT2) from citrus. CitSUT1 and CitSUT2 encode putative proteins (CitSUT1 and CitSUT2) of 528 and 607 amino acids, respectively. CitSUT1 and CitSUT2 share high similarities with sucrose transporters isolated from other plants. The expression of CitSUT1 in mature leaf discs is repressed by exogenous sucrose, glucose, mannose, and the glucose analog 2-deoxyglucose but not by another glucose analog 3-O-methylglucose, indicating a hexokinase (HXK)-mediated signaling pathway. CitSUT2 expression is not affected by exogenous sugars. Whereas CitSUT1 expresses strongly in source, sugar exporting organs, CitSUT2 expresses more strongly in sink, sugar importing organs, suggesting different physiological roles for these sucrose transporters.
[Effects of Embryonic Neural Stem Cells and Glial Cell Line-derived Neurotrophic Factor in the Repair of Spinal Cord Injury]
Sheng Li Xue Bao : [Acta Physiologica Sinica]. Jun, 2003 | Pubmed ID: 12817305
The ability of implanted embryonic neural stem cells (NSCs) to improve survival, migration, and functional recovery following a compression spinal cord injury (SCI) was tested in adult rats. NSCs were isolated from E14-16 rat cerebral cortex and SCI was produced by using an aneurysm clip applicator applied to the 8th thoracic spinal cord according to method of Dolan and Tator. Two weeks after the injury, NSCs (4 microl of 1 x 10(4) cells/microl) were injected into the lesion site. The grafted NSCs were noted to survive and integrate with the host spinal cord 1 month after transplantation, which was demonstrated by the presence of Hoechst 33342 (a nuclear dye) pre-labeled NSCs within and surrounding the lesion site. Some of these cells remained undifferentiated and were stained with nestin, a marker for NSCs. Transplanted NSCs migrated for at least 3 mm from the injury epicenter towards both the rostral and caudal directions. Significant reduction in the lesion area (P<0.05) and improvement in inclined plane (P<0.05) and BBB locomotor rating scale (P<0.05) were found in the cases that received implantation of NSCs, as compared with those that received vehicle injection. More importantly, when glial cell line-derived neurotrophic factor (GDNF; 1.5 microg/microl) was added to the transplants, further reduction in lesion area (P<0.01) and improvement in the function were observed in the combined treatment group as compared with the vehicle infused group. Our results suggest that intraspinal treatment with NSCs and GDNF synergistically reduced lesion size and improved functional outcome after a compressive SCI in adult rats.
Chronic NMDA Receptor Blockade from Birth Delays the Maturation of NMDA Currents, but Does Not Affect AMPA/kainate Currents
Journal of Neurophysiology. Jan, 2003 | Pubmed ID: 12522159
The activity of the N-methyl-D-aspartate receptor (NR) regulates the composition of excitatory synapses and mediates multiple forms of synaptic and structural plasticity. In the superficial superior colliculus (sSC) of the rat, NR activity is essential for the full refinement of retinotopy during development. We have examined the NR's role in synaptic development by chronically treating the sSC from birth with the competitive antagonist (+/-)-2-amino-5-phosphonopentanoic acid (AP5) released by the slow-release polymer Elvax. Whole-cell voltage-clamp recordings were used to characterize excitatory postsynaptic potentials (EPSCs) in slices from postnatal day (P)12-20 sSC. Chronic NR blockade reduced the ratio of AMPA/kainate receptor (AMPAR) to NR peak current amplitudes of both spontaneous (s)EPSCs and evoked EPSCs. Spontaneous NR current amplitude was increased following treatment, while spontaneous AMPAR currents were identical to those of controls, indicating that the ratio change was due to an increased NR current. Comparison of sEPSC frequency, AMPAR current rectification, and quantitative Western blots indicated that the characteristics of AMPARs at the synapse are normal following AP5 treatment. In the sSC, NR currents show a rapid decrease in decay time on P11 and previous studies in slices indicate this change results from a NR-mediated activation of the phosphatase calcineurin. Consistent with this in vitro finding, the down-regulation failed to occur in sSC chronically treated with AP5 in vivo. Together the present data show that NR function is necessary for subsequent NR current regulation in vivo, but it is not essential for the developmental expression of normal AMPAR currents.
Marginal Versus Joint Box-Cox Transformation with Applications to Percentile Curve Construction for IgG Subclasses and Blood Pressures
Statistics in Medicine. Feb, 2003 | Pubmed ID: 12529871
When age-specific percentile curves are constructed for several correlated variables, the marginal method of handling one variable at a time has typically been used. We address the question, frequently asked by practitioners, of whether we can achieve efficiency gains by joint estimation. We focus on a simple but common method of Box-Cox transformation and assess the statistical impact of a joint transformation to multivariate normality on the percentile curve estimation for correlated variables. We find that there is little gain from the joint transformation for estimating percentiles around the median but a noticeable reduction in variances is possible for estimating extreme percentiles that are usually of main interest in medical and biological applications. Our study is motivated by problems in constructing percentile charts for IgG subclasses of children and for blood pressures in adult populations, both of which are discussed in the paper as examples, and yet our general findings are applicable to a wide range of other problems.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi = Chinese Journal of Cellular and Molecular Immunology. Sep, 2003 | Pubmed ID: 15169659
To explore the relationship between inflammatory reaction and coronary heart disease (CHD).
Germline Transcription and Switch Recombination of a Transgene Containing the Entire H Chain Constant Region Locus: Effect of a Mutation in a STAT6 Binding Site in the Gamma 1 Promoter
Journal of Immunology (Baltimore, Md. : 1950). Nov, 2004 | Pubmed ID: 15494502
The switch (S) in H chain class is preceded by germline transcription and then mediated by a DNA recombination event. One of the impediments toward understanding the mechanism is the lack of a system in which a recombinant DNA molecule undergoes cytokine-regulated class S recombination. To study class S recombination, we used transgenic mice with a 230-kb bacterial artificial chromosome that included a rearranged VDJ gene and the entire murine H chain constant region locus. We found that both germline transcription and S recombination to the transgenic gamma1 H chain gene were regulated by IL-4 like that of the endogenous genes. In mice with two or more copies of the H chain locus transgene, both germline transcripts and S recombination took place at levels comparable to those from the endogenous loci. We also prepared a version of the transgene with a 4-bp mutation in a STAT6 binding site in the gamma1 promoter region. On the average, this mutation reduced germline transcription by 80%, but did not change the amount of S recombination in vitro. Among both the wild-type and mutant transgenes, we found no significant correlation between the amount of germline transcripts and the amount of S recombination. We infer that the physiologic level of germline transcription of the gamma1 gene is in excess over the amount required for efficient S recombination.
Statistics in Medicine. Jan, 2004 | Pubmed ID: 14695636
Grouped dose measures, heterogeneity and publication bias are three major problems for meta-analysis in trend estimation. In this paper, we propose a model that allows for arbitrarily aggregated dose levels, and show that the resulting estimates and standard errors can be quite different from those given by the usual assigned value method. Based on fitting a model to the funnel plot, we discuss a method for random-effects sensitivity analysis that deals with the problems of heterogeneity and publication bias. A meta-analysis of epidemiological studies on the effect of alcohol on the risk of breast cancer is used to illustrate the method. Our analysis suggests that the rate of increase in risk with alcohol consumption is substantially less than has been previously suggested.
Zhonghua Gan Zang Bing Za Zhi = Zhonghua Ganzangbing Zazhi = Chinese Journal of Hepatology. Jan, 2005 | Pubmed ID: 15670493
IEEE Transactions on Neural Systems and Rehabilitation Engineering : a Publication of the IEEE Engineering in Medicine and Biology Society. Mar, 2005 | Pubmed ID: 15813405
This paper presents analysis of the standing-up manoeuvre in paraplegia considering the body supportive forces as a potential feedback source in functional electrical stimulation (FES)-assisted standing-up. The analysis investigates the significance of arm, feet, and seat reaction signals to the human body center-of-mass (COM) trajectory reconstruction. The standing-up behavior of eight paraplegic subjects was analyzed, measuring the motion kinematics and reaction forces to provide the data for modeling. Two nonlinear empirical modeling methods are implemented--Gaussian process (GP) priors and multilayer perceptron artificial neural networks (ANN)--and their performance in vertical and horizontal COM component reconstruction is compared. As the input, ten sensory configurations that incorporated different number of sensors were evaluated trading off the modeling performance for variables chosen and ease-of-use in everyday application. For the purpose of evaluation, the root-mean-square difference was calculated between the model output and the kinematics-based COM trajectory. Results show that the force feedback in COM assessment in FES assisted standing-up is comparable alternative to the kinematics measurement systems. It was demonstrated that the GP provided better modeling performance, at higher computational cost. Moreover, on the basis of averaged results, the use of a sensory system incorporating a six-dimensional handle force sensor and an instrumented foot insole is recommended. The configuration is practical for realization and with the GP model achieves an average accuracy of COM estimation 16+/-1.8 mm in horizontal and 39+/-3.7 mm in vertical direction. Some other configurations analyzed in the study exhibit better modeling accuracy, but are less practical for everyday usage.
The 3' End of the Heavy Chain Constant Region Locus Enhances Germline Transcription and Switch Recombination of the Four Gamma Genes
The Journal of Experimental Medicine. May, 2005 | Pubmed ID: 15851486
The switch in immunoglobulin (Ig) heavy chain class is preceded by germline transcription and then mediated by a DNA recombination event. To study germline transcription and class switch recombination we used transgenic mice with a 230-kilobase bacterial artificial chromosome that included a rearranged VDJ gene and the entire heavy chain constant region locus. In addition to several lines with intact transgenes, we identified two lines in which the heavy chain locus transgene lacked Calpha and everything 3' of it, including the regulatory elements HS3a, HS1-2, HS3b, and HS4. B cells from both lines with the truncated transgenes make abundant transgenic (Tg) VDJCmu transcripts and IgM protein. Deletion of the 3' end of the locus results in dramatically reduced expression of both germline transcripts and switched VDJCH transcripts of the gamma3, gamma2b, gamma2a, and epsilon genes. In addition, the transgenes lacking the 3' end of the locus express reduced amounts of gamma1 germline transcripts and 2-3% of the amount of Tg IgG1 in tissue culture compared with intact transgenes. Finally, switch recombination to gamma1 is undetectable in the transgenes lacking the 3' elements, as measured by digestion circularization-polymerase chain reaction or by the expression of VDJCgamma1 transcripts.
Localization of All Seven Messenger RNAs for the Actin-polymerization Nucleator Arp2/3 Complex in the Protrusions of Fibroblasts
Journal of Cell Science. Jun, 2005 | Pubmed ID: 15923655
The actin-related protein 2/3 (Arp2/3) complex is a crucial actin polymerization nucleator and is localized to the leading protrusions of migrating cells. However, how the multiprotein complex is targeted to the protrusions remains unknown. Here, we demonstrate that mRNAs for the seven subunits of the Arp2/3 complex are localized to the protrusions in fibroblasts, supporting a hypothesis that the Arp2/3 complex is targeted to its site of function by mRNA localization. Depletion of serum from culture medium inhibits Arp2/3-complex mRNA localization to the protrusion, whereas serum stimulation leads to significant mRNA localization within 30 minutes. The effect of serum suggests that Arp2/3-complex mRNA localization is a cellular response to extracellular stimuli. The localization of the Arp2/3 complex mRNAs is dependent on both actin filaments and microtubules, because disruption of either cytoskeletal system (with cytochalasin D and colchicine, respectively) inhibited the localization of all seven subunit mRNAs. In addition, myosin inhibitors significantly inhibit Arp2 mRNA localization in chicken embryo fibroblasts, suggesting a myosin motor dependent mechanism for Arp2/3-complex mRNA localization.
Zhongguo Zhong Xi Yi Jie He Za Zhi Zhongguo Zhongxiyi Jiehe Zazhi = Chinese Journal of Integrated Traditional and Western Medicine / Zhongguo Zhong Xi Yi Jie He Xue Hui, Zhongguo Zhong Yi Yan Jiu Yuan Zhu Ban. May, 2005 | Pubmed ID: 15957843
To investigate the therapeutic effects of Aiyishu Injection (AYSI) on cancerous hydrothorax, quality of life (QOF), and cellular immune function of patients.
Zhonghua Gan Zang Bing Za Zhi = Zhonghua Ganzangbing Zazhi = Chinese Journal of Hepatology. Jul, 2005 | Pubmed ID: 16042906
The Modulation Effects of BmK I, an Alpha-like Scorpion Neurotoxin, on Voltage-gated Na(+) Currents in Rat Dorsal Root Ganglion Neurons
Neuroscience Letters. Dec, 2005 | Pubmed ID: 16129561
The present study investigated the effects of BmK I, a Na(+) channel receptor site 3 modulator purified from the Buthus martensi Karsch (BmK) venom, on the voltage-gated sodium currents in dorsal root ganglion (DRG) neurons. Whole-cell patch-clamping was used to record the tetrodotoxin-sensitive (TTX-S) and tetrodotoxin-resistant (TTX-R) components of voltage-gated Na(+) currents in small DRG neurons. It was found that the inhibitory effect of BmK I on open-state inactivation of TTX-S Na(+) currents was stronger than that of TTX-R Na(+) currents. In addition, BmK I exhibited a selective enhancing effect on voltage-dependent activation of TTX-S currents, and an opposite effect on time-dependent activation of TTX-S and TTX-R Na(+) currents. The results suggested that the inhibitory effect of BmK I on open-state inactivation might contribute to the increase of peak TTX-S and TTX-R currents, and the enhancing effect of BmK I on time-dependent activation might also contribute to the increase of peak TTX-S currents. It was further suggested that a combined effect of BmK I including inhibiting the inactivation of TTX-S and TTX-R channels, accelerating activation and decreasing the activation threshold of TTX-S channels, might produce a hyperexcitability of small DRG neurons, and thus contribute to the BmK I-induced hyperalgesia.
Chemosphere. Nov, 2005 | Pubmed ID: 16219507
Recent tests have detected high lead (Pb) concentrations in some commercial brands of tea leaves and this finding has raised concerns due to the possible health-related problems associated with Pb poisoning. In present research, we investigated the Pb contamination in tea leaves produced in Zhejiang province in China. Pb concentrations in all tea leaves sampled were below 5 mg/kg, the permissible levels given by Chinese Ministry of Agriculture, indicating that Pb contamination in this province is not excessive. We then investigated the non-edaphic factors that may potentially contribute to Pb accumulation in tea leaves. Pb concentration in tea leaves was found to be positively correlated with the industrialization level of a district (R = 0.83, the significant level at P < 0.05), and greater amounts of Pb were washed from the leaves of plants in districts with more industrial activity. This suggests that Pb accumulation in tea leaves could, in part, be attributed to industrial activity through the precipitation of atmospheric Pb. Furthermore greater amounts of Pb were washed from the leaves of plants growing near road than those growing farther away from road. This trend indicates that automobile activity was another likely contributor to Pb accumulation in tea. Pb content of green tea was also affected by the processing of the leaves in the factory. In particular the twisting and water-removal stages caused increases in Pb content in the tea product. This study suggests that non-edaphic factors also contribute to the Pb accumulation in tea.
Conference Proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference. 2005 | Pubmed ID: 17281381
For diagnosing the colon's pathologies micro-invasively or non-invasively actively, an autonomous prototype of the earthworm-like robot for colonoscopy was designed according with the principle of the bionics and manufactured using precision process technology. In-Vitro experiments in pig colon were made. This micro robot for colonoscopy was drove directly by elecmagnetic linear driver. The mobile cells were joined with two degree-of-freedom joints and the whole body was flexible. The direction of movement and the angle of imaging can be controlled by the shape memory alloy (SMA). In experiments, locomotion efficient was analyzed carefully. In-vitro experiments in pig colon demonstrated that the micro robot can navigate though the colon by itself reliably and freely, which was useful to the application of robot for colonoscopy in the clinic.
The International Journal of Biochemistry & Cell Biology. 2006 | Pubmed ID: 16950644
Protein kinase C (PKC) is a member of serine/threonine protein kinase family that plays important roles in the control of vast variety of cellular functions. Nevertheless, the regulatory effect of PKC on adipogenesis remained not well understood. In this study, we investigated the effect of several PKC isoforms on the adipogenic conversion of 3T3-L1 preadipocytes induced by dexamethasone, isobutylmethylxanthine and insulin. Treatment of cells with broad-spectrum PKC inhibitor Rö318220 suppressed the adipogenesis. Gö6976, a selective inhibitor for PKC isoforms-alpha, -betaI and -mu, also inhibited the adipogenesis of cells. Pretreatment of cells with peroxisomal proliferator activated receptor-gamma (PPARgamma) agonist troglitazone abolished the inhibitory effect of Gö6976 on adipogenesis. The plasmic membrane translocation of PKC-betaI was observed at the first 2 days of differentiation. Whereas no translocation of PKC-alpha and -mu was observed. Overexpression of dominant negative PKC-betaI, but not wild-type PKC-betaI, blocked adipogenesis. This effect of dominant negative PKC-betaI can be reversed by troglitazone, suggesting that PKC-betaI is required for the initiation of adipogenesis. In addition, rottlerin, a specific inhibitor of PKC-delta, can reverse the suppression of adipogenesis mediated by 12-O-tetradecanoyl-phorbol-13-acetate, transforming growth factor-beta1, and epidermal growth factor. These data suggest that PKC-betaI is important in the induction of adipogenesis, while the PKC-delta has an inhibitory role for adipogenesis.
Regulation of Transforming Growth Factor-beta 1-induced Apoptosis and Epithelial-to-mesenchymal Transition by Protein Kinase A and Signal Transducers and Activators of Transcription 3
Cancer Research. Sep, 2006 | Pubmed ID: 16951175
Apoptosis and epithelial-to-mesenchymal transdifferentiation or transition (EMT) are crucial for normal development and body homeostasis. The alterations of these events are closely related to some pathologic processes, such as tumor formation and metastasis, fibrotic diseases of liver and kidney, and abnormal development of embryos. The mechanism that underlies the simultaneously occurring apoptosis and EMT induced by transforming growth factor-beta (TGF-beta) has not been well studied. In this report, we investigated the potential mechanism that underlies TGF-beta1-induced apoptosis and EMT. TGF-beta1-induced apoptosis and EMT were associated with the activation of protein kinase A (PKA) and signal transducers and activators of transcription 3 (STAT3). Inhibition of PKA by specific PKA inhibitor H89 or by PKA inhibitor peptide blocked STAT3 activation and suppressed TGF-beta1-induced apoptosis and EMT. Furthermore, overexpression of a phosphorylation-deficient form of STAT3, but not wild-type STAT3, produced an inhibitory effect on TGF-beta1-induced apoptosis and EMT. The results indicate that PKA is an upstream regulator for TGF-beta1-induced STAT3 activation and plays an important role in TGF-beta1-mediated apoptosis and EMT. These studies provided a new insight into the signaling mechanism underlying the apoptosis and EMT, which could be of importance in understanding some related physiologic and pathologic processes.
Rabbit Embryonic Stem Cell Lines Derived from Fertilized, Parthenogenetic or Somatic Cell Nuclear Transfer Embryos
Experimental Cell Research. Nov, 2006 | Pubmed ID: 16996056
Embryonic stem cells were isolated from rabbit blastocysts derived from fertilization (conventional rbES cells), parthenogenesis (pES cells) and nuclear transfer (ntES cells), and propagated in a serum-free culture system. Rabbit ES (rbES) cells proliferated for a prolonged time in an undifferentiated state and maintained a normal karyotype. These cells grew in a monolayer with a high nuclear/cytoplasm ratio and contained a high level of alkaline phosphate activity. In addition, rbES cells expressed the pluripotent marker Oct-4, as well as EBAF2, FGF4, TDGF1, but not antigens recognized by antibodies against SSEA-1, SSEA-3, SSEA-4, TRA-1-10 and TRA-1-81. All 3 types of ES cells formed embryoid bodies and generated teratoma that contained tissue types of all three germ layers. rbES cells exhibited a high cloning efficiency, were genetically modified readily and were used as nuclear donors to generate a viable rabbit through somatic cell nuclear transfer. In combination with genetic engineering, the ES cell technology should facilitate the creation of new rabbit lines.
Journal of Immunology (Baltimore, Md. : 1950). Oct, 2006 | Pubmed ID: 17015727
IgG2a, with gamma2a H chains, is important for protection against viruses and other intracellular pathogens. Although a large portion of IgG2a expression is dependent upon IFN-gamma, some germline transcription and switch recombination to the murine gamma2a H chain gene expression are independent of IFN-gamma. We found that agonistic anti-CD40 Abs injected into IFN-gamma-deficient mice induce a > 200-fold increase in the amount of serum Ig2a, while other Ig isotypes are increased by 16-fold or less. In vitro, ligation of CD40 on B cells, without the addition of other B cell activators or cytokines, results in germline transcription and switch recombination that are largely restricted to the gamma2a gene. These results suggest that some immune responses to infectious agents can result in large amounts of IgG2a expression through ligation of CD40, without the expression of IFN-gamma by Th1 or other cells.
Liver International : Official Journal of the International Association for the Study of the Liver. Nov, 2006 | Pubmed ID: 17032414
To analyze the gene expression pattern in rat hepatic fibrogenesis and further assess the role of some key genes during the pathological process.
Cryoelectron Microscopy and EPR Analysis of Engineered Symmetric and Polydisperse Hsp16.5 Assemblies Reveals Determinants of Polydispersity and Substrate Binding
The Journal of Biological Chemistry. Dec, 2006 | Pubmed ID: 17079234
We have identified sequence and structural determinants of oligomer size, symmetry, and polydispersity in the small heat shock protein super family. Using an insertion mutagenesis strategy that mimics evolutionary sequence divergence, we induced the ordered oligomer of Methanococcus jannaschii Hsp16.5 to transition to either expanded symmetric or polydisperse assemblies. A hybrid approach combining spin labeling EPR and cryoelectron microscopy imaging at 10A resolution reveals that the underlying plasticity is mediated by a packing interface with minimal contacts and a flexible C-terminal tether between dimers. Twenty-four dimeric building blocks related by octahedral symmetry assemble into the expanded symmetric oligomer. In contrast, the polydisperse variant has an ordered dimeric building block that heterogeneously packs to yield oligomers of various sizes. Increased exposure of the N-terminal region in the Hsp16.5 variants correlates with enhanced binding to destabilized mutants of T4 lysozyme, whereas deletion of this region reduces binding. Transition to larger intermediates with enhanced substrate binding capacity has been observed in other small heat shock proteins including lens alpha-crystallin mutants linked to congenital cataract. Together, these results provide a mechanistic perspective on substrate recognition and binding by the small heat shock protein superfamily.
Digestive Diseases and Sciences. Dec, 2006 | Pubmed ID: 17080243
Our objective was to explore the restorative effect of taurine on experimental nonalcoholic steatohepatitis (NASH). Thirty-six SD rats were randomly divided into three groups, 12 in each group: the normal group was fed standard rat diet; the model group and the treatment group were both fed a high-fat rat diet for 12 weeks, and the rats in the treatment group were simultaneously injected with taurine subcutaneously for 8 weeks. Hepatic histological change was observed; TNF-alpha and TGF-beta(1) protein expression was identified by immunohistochemistry; mRNA expression of TNF-alpha, TGF-beta(1), type I procollagen, and adiponectin was measured by RT-PCR; body weight, weight gain, liver weight, and liver index were measured; and biochemical parameters monitored included serum transaminases, serum lipids, fasting plasma glucose, and hepatic level of oxidative stress. Rats in the model group showed a significant increase in liver weight, liver index, serum transaminase activities, serum triglyceride, fasting plasma glucose, and oxidative stress; the mRNA expression of TNF-alpha, TGF-beta(1), and type I procollagen increased, whereas the expression of adiponectin decreased significantly, compared with that in the normal group. The typical hepatic lesions of NASH were observed histologically in the model group. Taurine treatment resulted in a significant decrease in liver weight, liver index, serum transaminase activities, serum triglyceride, fasting plasma glucose, and oxidative stress; the mRNA expression of TNF-alpha, TGF-beta(1), and type I procollagen decreased, but the expression of adiponectin increased significantly, compared with that in the model group. Histological improvement was observed in the treatment group. In conclusion, taurine could inhibit lipid peroxidation, improve lipid and glucose metabolism, decrease synthesis of TNF-alpha and TGF-beta(1), promote synthesis of adiponectin, and have a restorative effect on experimental NASH.
Clinical Biochemistry. Jan, 2006 | Pubmed ID: 16330012
To establish a modified microarray method for detecting HBV gene mutations in the clinic.
The Anti-nociceptive Effect of BmK AS, a Scorpion Active Polypeptide, and the Possible Mechanism on Specifically Modulating Voltage-gated Na+ Currents in Primary Afferent Neurons
Peptides. Sep, 2006 | Pubmed ID: 16716457
In the present study, we investigated the anti-nociceptive effect and the underlying mechanism of BmK AS, an active peptide purified from scorpion Buthus martensi Karsch. The results showed that BmK AS can significantly relieve formalin-induced two-phase spontaneous flinching response and carrageenan-induced mechanical hyperalgesia. Using the whole-cell patch-clamp recording, exposure of acutely isolated sensory neurons to 500 nM BmK AS produced a one-fold decrease in the number of action potentials (APs) evoked by a ramp of depolarizing current. To investigate the mechanism of action of BmK AS, isolated membrane current and Ca2+ influx on rat primary sensory neurons were examined. BmK AS produced insignificant effect on voltage-dependent I(K) and KCl or caffeine-induced Ca2+ influx, but caused remarkable suppressive effect on tetrodotoxin-resistant (TTX-R) and tetrodotoxin-sensitive (TTX-S) I(Na). Further experiments showed that BmK AS reduced the peak TTX-R and TTX-S Na+ conductance in a dose-dependent manner, prompted the voltage-dependent activation, and caused a negative shift of the steady-state inactivation of TTX-R and TTX-S I(Na). Thus, the present results indicate the anti-nociceptive response of BmK AS may be ascribed to its specific modulation of voltage-gated Na+ channels of sensory neurons.
Application of Microdialysis to Study the in Vivo Release of Pingyangmycin from in Situ Gels in Rabbits
Biomedical Chromatography : BMC. Nov, 2006 | Pubmed ID: 16799932
Microdialysis was used together with HPLC to monitor the local concentration of pingyangmycin hydrochloride (PYM) after embolizing rabbit ear-veins with an injectable sustained release formulation, PYM-Zein/PYM-Zein-sucrose acetate isobutyrate (SAIB), in situ gel. The dialysis probe was perfused at 2 microL/min. The in vivo recovery was 46.6 3.1% (n = 4). The samples were injected directly into HPLC. PYM was detected using UV detector at 291 nm. Separation from other components in the dialysate was performed using a Discovery((R)) RP-Amide C(16) column within 12 min. The response for PYM in the dialysate was linear (r(2) > 0.996) over the range of 2.5-212 microg/mL. The limit of detection and limit of quantitation of PYM in the dialysate were 0.4 and 1.5 microg/mL, respectively. The results demonstrated that the in situ gel of PYM-Zein-SAIB could extend the release of PYM to 4 days. SAIB could significantly cut down the initial burst of PYM from the in situ gels (p < 0.05).
Long-term Effects of Mid-dose Ursodeoxycholic Acid in Primary Biliary Cirrhosis: a Meta-analysis of Randomized Controlled Trials
The American Journal of Gastroenterology. Jul, 2006 | Pubmed ID: 16863557
The effect of ursodeoxycholic acid (UDCA) treatment on survival and liver histological progression of primary biliary cirrhosis (PBC) remains uncertain. The aim of this study is to assess the long-term efficacy of mid-dose UDCA treatment for PBC.
[Determination of Puerarin in Kangshen Granule by Reversed-phase High Performance Liquid Chromatography]
Se Pu = Chinese Journal of Chromatography / Zhongguo Hua Xue Hui. Sep, 2006 | Pubmed ID: 17165545
Kangshen granule, containing 12 kinds of traditional Chinese medicine, has complex composition. A new method for the determination of puerarin in Kangshen granule was developed using reversed-phase high performance liquid chromatography coupled with matrix assisted laser desorption ionization time of flight mass spectrometry and ultraviolet detection (RP-HPLC/MALDI-TOF MS/UV). The sample was separated by RP-HPLC with a non-linear gradient elution, and then was qualitatively detected by mass spectrometry to identify the puerarin peak. The chromatographic process was performed on a YMC-ODS column under the optimized conditions with a mobile phase consisting of methanol, water and 0.1% TFA, and detected at 250 nm. The linear range of puerarin was from 0. 132 to 1.32 microg (r = 0.9997). The recovery was higher than 103% and the relative standard deviation was lower than 2.0% (n=6). The puerarin content in Kangshen granule sample was determined and the puerarin content was 3.09 mg/g. The method is simple and feasible for the determination of puerarin with a good repeatability. The method can be used for quality control of Kangshen granule.
An Analysis of the Current Status of Hospital Emergency Preparedness for Infectious Disease Outbreaks in Beijing, China
American Journal of Infection Control. Feb, 2007 | Pubmed ID: 17276793
In the event of a large-scale infectious disease outbreak, hospitals will play a critical role. The objective of our study is to understand the current status of hospitals preparedness for infectious disease outbreaks in Beijing and to provide basic information for infectious disease prevention and control in hospitals.
The Absence of Enhanced Disease with Wild Type Respiratory Syncytial Virus Infection Occurring After Receipt of Live, Attenuated, Respiratory Syncytial Virus Vaccines
Vaccine. Oct, 2007 | Pubmed ID: 17868959
Early in the development of respiratory syncytial virus (RSV) vaccines severe disease occurred in children after receipt of formalin-inactivated RSV vaccine. Continuing efforts to develop an appropriately attenuated and immunogenic live RSV vaccine have given opportunities to assure that live vaccines are safe through surveillance of children after vaccination. In the present study, the rate of RSV-associated upper respiratory tract illness in 388 children was lower in RSV vaccinated children than in controls (14% versus 20% in a 6-24 month old group and 16% versus 25% in infants). Additionally, there was no evidence that vaccination predisposed to more severe lower respiratory tract illness. Thus infection with a series of live attenuated RSV vaccines did not result in enhanced disease upon infection with wild type RSV. The impact of RSV during this surveillance will inform the design of future efficacy studies with RSV vaccines.
Physical and Intellectual Development in Children with Asymptomatic Congenital Cytomegalovirus Infection: a Longitudinal Cohort Study in Qinba Mountain Area, China
Journal of Clinical Virology : the Official Publication of the Pan American Society for Clinical Virology. Nov, 2007 | Pubmed ID: 17919973
Although about 90% of congenital cytomegalovirus (CMV) infection is asymptomatic in newborn, some of them could show sequelae later in life. Qinba mountain area is a place with high incidence of mental retardation and a high rate of CMV intrauterine transmission in China. The correlation between asymptomatic congenital CMV infection and developmental outcomes of children in this area remain unclear.
Analysis of Binding Interaction Between Puerarin and Bovine Serum Albumin by Multi-spectroscopic Method
Journal of Pharmaceutical and Biomedical Analysis. Nov, 2007 | Pubmed ID: 17942262
The interaction of puerarin and bovine serum albumin (BSA) was investigated by means of fluorescence spectroscopy, resonance light-scattering spectroscopy, infrared spectroscopy, and synchronous fluorescence spectra. The apparent binding constants (K(a)) between puerarin and BSA were 1.13 x 10(4) (20 degrees C), and 1.54 x 10(4) lmol(-1) (30 degrees C), and the binding sites values (n) were 0.95+/-0.02. The experimental results showed that the puerarin could be inserted into the BSA, quenching the inner fluorescence by forming the puerarin-BSA complex. The addition of increasing puerarin to BSA solution leads to the gradual decrease in RLS intensity, exhibiting the formation of the aggregate in solution. It was found that both static quenching and non-radiation energy transfer were the main reasons for the fluorescence quenching. The positive entropy change and enthalpy change indicated that the interaction of puerarin and BSA was driven mainly by hydrophobic forces. The process of binding was a spontaneous process in which Gibbs free energy change was negative. The competing binding reaction with BSA between Fe(3+), Cu(2+) and puerarin was investigated. The effect of Fe(3+) and Cu(2+) on the binding of puerarin with BSA is discussed.
International Journal of Pharmaceutics. Jan, 2007 | Pubmed ID: 16939703
Venous malformations (VM) are common vascular abnormality, and their management remains difficult. Pingyangmycin hydrochloride (PYM) is a useful sclerosant to treat venous malformations. This study was aimed to evaluate the effect of a new drug delivery system, PYM-loaded Zein/Zein-sucrose acetate isobutyrate (SAIB) in situ gels, in gelling and extending the local release of PYM. It was demonstrated that in vitro and in vivo release of PYM from the in situ gels could be extended up to 7 and 4 days, respectively. SAIB could significantly cut down the initial burst of PYM from the in situ gels (P<0.05). The possible gel forming and drug release mechanisms were described according to the morphology analysis by atomic force microscopy (AFM), optical microscopy and SEM. The gel forming efficacy and the viscosity of in situ gel solutions were satisfying.
Intranasal Administration with NAD+ Profoundly Decreases Brain Injury in a Rat Model of Transient Focal Ischemia
Frontiers in Bioscience : a Journal and Virtual Library. 2007 | Pubmed ID: 17127275
Excessive poly(ADP-ribose) polymerase-1 (PARP-1) activation plays a significant role in ischemic brain damage. Increasing evidence has supported the hypothesis that PARP-1 induces cell death by depleting intracellular NAD+. Based on our in vitro finding that NAD+ treatment can abolish PARP-1-mediated cell death, we hypothesized that NAD+ administration may decrease ischemic brain injury. In this study, we used a rat model of transient focal ischemia to test this hypothesis. We observed that intranasal NAD+ delivery significantly increased NAD+ contents in the brains. Intranasal delivery with 10 mg/kg NAD+ at 2 hours after ischemic onset profoundly decreased infarct formation when assessed either at 24 or 72 hours after ischemia. The NAD+ administration also significantly attenuated ischemia-induced neurological deficits. In contrast, intranasal administration with 10 mg/kg nicotinamide did not decrease ischemic brain damage. These results provide the first in vivo evidence that NAD+ metabolism is a new target for treating brain ischemia, and that NAD+ administration may be a novel strategy for decreasing brain damage in cerebral ischemia and possibly other PARP-1-associated neurological diseases.
Enantioselective Cyanosilylation of Alpha,alpha-dialkoxy Ketones Catalyzed by Proline-derived In-situ-prepared N-oxide As Bifunctional Organocatalyst
The Journal of Organic Chemistry. Mar, 2007 | Pubmed ID: 17338569
Bifunctional N,N'-dioxide catalysts have been developed for highly enantioselective cyanosilylation of alpha,alpha-dialkoxy ketones. This process, catalyzed by in-situ-prepared proline-derived N,N'-dioxide 2b, produced the corresponding cyanohydrin trimethylsilyl ethers in excellent yields (up to 99%) with high enantioselectivities (up to 93% ee). A reasonable mechanism was proposed according to the observation of the linear effect, 1H NMR spectra, isolated cyanohydrin, and the roles of the NH and N-oxide moieties of the catalyst.
Protein Expression and Purification. Jul, 2007 | Pubmed ID: 17408968
Catalase is one of the antioxidant enzymes and is involved in many pathophysiologic processes and human diseases. This study focused on high-level expression and purification of recombinant catalase in Pichia pastoris. The cDNA encoding catalase was cloned by RT-PCR from Fetal liver of Homo sapiens. After PCR and construction of expression vector pPIC9K-CAT, human catalase was expressed highly in P. pastoris yeast SMD1168 and secreted into the culture medium. The secreted catalase was purified to a purity of 95% by ammonium sulfate fractionation, anionic exchange-chromatography, and Macro-prep Ceramic Hydroxyapatite with a overall yield of 60%. This study provides a new method for large-scale expression and purification of recombinant protein catalase.
Comparison of Results of Detection of Rhinovirus by PCR and Viral Culture in Human Nasal Wash Specimens from Subjects with and Without Clinical Symptoms of Respiratory Illness
Journal of Clinical Microbiology. Jul, 2007 | Pubmed ID: 17475758
Human rhinoviruses (HRV) cause acute upper respiratory illness. The frequency of HRV-associated illnesses appears greater when PCR assays are used to detect rhinoviruses. The present study performed PCR-based detection of HRV upon entry of subjects into respiratory syncytial virus and parainfluenza type 3 vaccine trials when subjects were symptom-free and upon subsequent development of clinical symptoms of respiratory illness during the trial. The background of HRV PCR positivity in symptom-free individuals (30/139 [22%]) was only slightly lower than in those with respiratory illness (28/77 [36%]). For subjects with multiple samples, it was estimated that HRV was detectable by PCR for approximately 100 days before, during, and after clinical symptoms were documented. PCR is a remarkably more sensitive method of detecting HRV than is tissue culture. The presence of HRV RNA may not always reflect an association with infectious virus production. The limited association of HRV RNA with illness suggests caution in assigning causality of HRV PCR positivity to clinical symptoms of respiratory illness.
[Pharmacokinetics of Pingyangmycin Hydrochloride in Rabbits Determined by Microdialysis Coupled with RP-HPLC]
Yao Xue Xue Bao = Acta Pharmaceutica Sinica. Mar, 2007 | Pubmed ID: 17520830
Microdialysis coupled with RP-HPLC was used to study the blood pharmacokinetics of pingyangmycin hydrochloride in rabbits. Supelco RP-amide C16 column was adopted for the analysis of pingyangmycin hydrochloride. The data was analyzed with 3P87 program. The calibration curve was linear in the concentration range from 1.04 to 66.56 microg x mL(-1) (r2 = 0.999 4). The in vivo recovery of microdialysis probe was (42.8 +/- 3.4)% (n = 4). The concentration-time curve of pingyangmycin hydrochloride was fitted to two-compartment model. T1/2 alpha and T1/2 beta were 14.9 and 60.3 min, respectively. The method is proved to be accurate, simple and suitable for the pharmacokinetics study of pingyangmycin hydrochloride in rabbits.
[Association of P16, P53, Ki-67 Expressions with High-risk Human Papilloma Virus Infection in Cervical Intraepithelial Neoplasia]
Nan Fang Yi Ke Da Xue Xue Bao = Journal of Southern Medical University. Apr, 2007 | Pubmed ID: 17545048
To investigate the association between p16, p53 and Ki-67 expression and high-risk human papilloma virus (HPV) infection in cervical intraepithelial neoplasia (CIN).
Injury-induced Neurogenesis in Bax-deficient Mice: Evidence for Regulation by Voltage-gated Potassium Channels
The European Journal of Neuroscience. Jun, 2007 | Pubmed ID: 17610570
Adult neural stem and progenitor cells may help remodel the brain in response to injury. The pro-apoptotic molecule Bax has recently been identified as a key player in adult neural stem cell survival. In Bax-deficient mice that have undergone traumatic brain injury, we find increased numbers of neural progenitor cells in the dentate gyrus and improved remodeling of the hippocampus. Exogenous potassium chloride mimics spreading depression (SD)-like events in vitro, and Bax-deficient neural stem cells proliferate in response to these events more robustly than wild-type neural stem cells. Selective potassium channel blockers interrupt SD-mediated stimulation of stem cells. In addition, the potassium channel Kv4.1 is expressed within neural stem and progenitor cells in the dentate gyrus and is increased in Bax-deficiency. These data suggest that the neuroprotection observed after injury in Bax-deficiency may be due to increased neurogenesis via activation of the Kv4 family of potassium channels.
Cellular Physiology and Biochemistry : International Journal of Experimental Cellular Physiology, Biochemistry, and Pharmacology. 2007 | Pubmed ID: 17762178
Syncytin-A, a new mouse endogenous retroviral envelope protein expressed in placenta, can mediate cell fusion in vitro. But its physiological function was still unknown. We proposed a role for syncytin-A in syncytiotrophoblast (SynT) formation derived from the differentiation of trophoblast stem (TS) cells during placental development. To evaluate this hypothesis, we analyzed the involvement of syncytin-A in the differentiation of mouse TS cells. After withdrawing fibroblast growth factor 4 (FGF4), TS cells can fuse to form SynT cells. We found syncytin-A mRNA and protein expression are colinear with fusion index increase during TS cell differentiation. Expression of syncytin-A is localized in SynT cells through in situ immunofluorescent staining. By using specific antibody and antisense oligonucleotides, we demonstrated that inhibition of syncytin-A lead to obvious decrease of SynT cell formation. These results present evidence in support of the direct role for syncytin-A in mouse TS cell fusion and differentiation involved in placental development.
Gene Expression Profile Analysis of the Spontaneous Reversal of Rat Hepatic Fibrosis by CDNA Microarray
Digestive Diseases and Sciences. Oct, 2007 | Pubmed ID: 17805973
Our aim was to gain insight into the gene expression profile during hepatic fibrosis autoreversal. Spontaneous recovery from hepatic fibrosis was created in SD rats by CCl(4) exposure for 8 weeks and then withdrawal for 6 weeks. Then differentially expressed genes during regression of fibrosis were analyzed using cDNA microarray. Results obtained were further subjected to hierarchical clustering and validated by semiquantitative RT-PCR. Expression of Mapk1 and Rps6ka1, which are critical members of the mitogen-activated protein kinase (MAPK) signaling pathway, was also investigated by Northern blot and immunohistochemistry. Microarray hybridization identified 254 genes differentially expressed throughout resolution of fibrosis. Being verified by RT-PCR, up- or down-regulated genes were classified into various groups according to clustering and function: (1) metabolic enzymes, (2) facilitated diffusion proteins/transporters/symporters, (3) gastrointestinal hormones/receptors, (4) lipoproteins/fatty acid binding proteins, (5) transcription factors/nuclear factors, and (6) the MAPK signaling pathway. The mRNA level of Mapk1 increased greatly as hepatic fibrosis reversed. Meanwhile Mapk1 and Rps6ka1 were proven to be expressed in hepatocytes and absent from mesenchymal cells. Six groups of genes exhibit a close relation to the recovery of CCl(4)-induced hepatic fibrosis. The MAPK signaling-dependent pathway, representing one of the gene groups, may contribute to the reversal of hepatic fibrosis.
Structure-guided Drug Design: Conferring Selectivity Among Neuronal Nicotinic Receptor and Acetylcholine-binding Protein Subtypes
Biochemical Pharmacology. Oct, 2007 | Pubmed ID: 17826748
Neuronal nicotinic receptors, encoded by nine genes of the alpha and three of the beta type of subunits, and whose gene products assemble in distinct permutations as pentameric molecules, constitute a fertile area for structure-guided drug design. Design strategies are augmented by a wide variety of peptide, alkaloid and terpenoid toxins from various marine and terrestrial species that interact with nicotinic receptors. Also, acetylcholine-binding proteins from mollusks, as structural surrogates of the receptor that mimic its extracellular domain, provide atomic resolution templates for analysis of structure and response. Herein, we describe a structure-guided approach to nicotinic ligand design that employs crystallography of this protein as the basic template, but also takes into consideration the dynamic properties of the receptor molecules in their biological media. We present the crystallographic structures of several complexes of various agonists and antagonists that associate with the agonist site and can competitively block the action of acetylcholine. In so far as the extracellular domain is involved, we identify additional non-competitive sites at those subunit interfaces where agonists do not preferentially bind. Ligand association at these interface sites may modulate receptor function. Ligand binding is also shown by solution-based spectroscopic and spectrometric methods to affect the dynamics of discrete domains of the receptor molecule. The surrogate receptor molecules can then be employed to design ligands selective for receptor subtype through the novel methods of freeze-frame, click chemistry that uses the very structure of the target molecule as a template for synthesis of the inhibitor.
Tetra-kis(μ-phenoxy-acetato-κO:O')bis-[(1,10-phenanthroline-κN,N')manganese(II)] Methanol Hemisolvate
Acta Crystallographica. Section E, Structure Reports Online. 2007 | Pubmed ID: 21200511
The title complex, [Mn(2)(C(8)H(7)O(3))(4)(C(12)H(8)N(2))(2)]·0.5CH(3)OH, is a carboxyl-ate-bridged dinuclear Mn(II) complex with four phenoxy-acetate ions and two 1,10-phenanthroline mol-ecules as ligands. Each of the four phenoxy-acetate anions bridges the pair of Mn atoms. The asymmetric unit is completed by a half-occupancy methanol solvent mol-ecule. Face-to-face π-π stacking inter-actions between the aromatic rings of 1,10-phenanthroline molecules belonging to adjacent Mn(2) complexes, with an inter-planar separation of circa 3.4 Å, and weak C-H⋯O hydrogen bonds connect the dinuclear units into a three-dimensional supra-molecular framework.
DNA Sequence : the Journal of DNA Sequencing and Mapping. Feb, 2008 | Pubmed ID: 17852331
The product of the POUSF1 gene, Oct4, plays an important role both in embryonic development and in the self-renewal and differentiation of totipotent cells. To understand the function of Oct4 in rabbit ES cells, we cloned and sequenced the rabbit POU5F1 gene, as well as the cDNA encoded by the gene. The Oct4 cDNA contains a 1083 bp ORF encoding a 360 aa protein and a 241 bp 3' UTR sequence. Oct4 mRNA was expressed at a high level in rabbit ES cells and was barely detectable in the adult spleen, kidney, brain and muscle tissues. The POU5F1 gene is approximately 6 kb in length and includes five exons and four introns. Gene organization is similar to that of the mouse, human and bovine orthologs. Sequencing of the gene revealed an 82% (mouse), 90% (human) and 89% (bovine) overall identity at the protein level. The rabbit POUSF1 gene was mapped to chromosome 12q1.1 by PCR amplification of DNA from two putative POU5F1-containing BAC clones, which were previously mapped to chromosome 12q1.1. The cloning of the rabbit POU5F1 gene will facilitate studies on its roles in rabbit embryogenesis and ES cells.
Inhibition of Martentoxin on Neuronal BK Channel Subtype (alpha+beta4): Implications for a Novel Interaction Model
Biophysical Journal. May, 2008 | Pubmed ID: 18199674
Martentoxin as a 37-residue peptide was capable of blocking large-conductance Ca(2+)-activated K(+) (BK) channels in adrenal medulla chromaffin cells. This study investigated the pharmacological discrimination of martentoxin on BK channel subtypes. The results showed that the iberiotoxin-insensitive neuronal BK channels (alpha+beta4) could be potently blocked by martentoxin (IC(50) = approximately 80 nM). In contrast, the iberiotoxin-sensitive BK channel consisting of only alpha-subunit was less sensitive to martentoxin. Distinctively, martentoxin inhibited neuronal BK channels (alpha+beta4) with a novel interaction mode. Two possible interaction sites of neuronal BK channels (alpha+beta4) might be responsible for the binding with martentoxin: one for trapping and the other located at the pore region for blocking. In addition, the inhibition of martentoxin on neuronal BK channels (alpha+beta4) depended on cytoplasmic Ca(2+) concentration. On the other hand, in vivo experiments from EEG recordings suggested that neuronal BK channels (alpha+beta4) were the primary target of martentoxin. Therefore, this research not only sheds light on a unique ligand for neuronal BK channels (alpha+beta4), but also highlights a novel model approach for the interaction between K(+) channels and specific-ligands.
Bioresource Technology. Sep, 2008 | Pubmed ID: 18242083
White rot fungi degrade lignin and have biotechnological applications in conversion of lignocellulose to valuable products. Pretreatment is an important processing step to increase the accessibility of cellulosic material in plant biomass, impacting efficiency of subsequent hydrolysis and fermentation. This study investigated microbial pretreatment of cotton stalks by solid state cultivation (SSC) using Phanerochaete chrysosporium to facilitate the conversion into ethanol. The effects of substrate moisture content (M.C.; 65%, 75% and 80% wet-basis), inorganic salt concentration (no salts, modified salts without Mn(2+), modified salts with Mn(2+)) and culture time (0-14 days) on lignin degradation (LD), solids recovery (SR) and availability of carbohydrates (AOC) were examined. Moisture content significantly affected lignin degradation, with 75% and 80% M.C. degrading approximately 6% more lignin than 65% M.C. after 14 days. Within the same moisture content, treatments supplemented with salts were not statistically different than those without salts for LD and AOC. Within the 14day pretreatment, additional time resulted in greater lignin degradation, but indicated a decrease in SR and AOC. Considering cost, solid state cultivation at 75% M.C. without salts was the most preferable pretreatment resulting in 27.6% lignin degradation, 71.1% solids recovery and 41.6% availability of carbohydrates over a period of 14 days. Microbial pretreatment by solid state cultivation has the potential to be a low cost, environmentally friendly alternative to chemical approaches. Moisture relationships will be significant to the design of an effective microbial pretreatment process using SSC technology.
Cryo-EM Structure of the DNA-dependent Protein Kinase Catalytic Subunit at Subnanometer Resolution Reveals Alpha Helices and Insight into DNA Binding
Structure (London, England : 1993). Mar, 2008 | Pubmed ID: 18334221
The DNA-dependent protein kinase catalytic subunit (DNA-PKcs) regulates the nonhomologous end joining pathway for repair of double-stranded DNA (dsDNA) breaks. Here, we present a 7A resolution structure of DNA-PKcs determined by cryo-electron microscopy single-particle reconstruction. This structure is composed of density rods throughout the molecule that are indicative of alpha helices and reveals structural features not observed in lower resolution EM structures. Docking of homology models into the DNA-PKcs structure demonstrates that up to eight helical HEAT repeat motifs fit well within the density. Surprisingly, models for the kinase domain can be docked into either the crown or base of the molecule at this resolution, although real space refinement suggests that the base location is the best fit. We propose a model for the interaction of DNA with DNA-PKcs in which one turn of dsDNA enters the central channel and interacts with a resolved alpha-helical protrusion.
The Journal of Pediatrics. Sep, 2008 | Pubmed ID: 18534242
To evaluate the safety and immunogenicity of an additional birth dose of diphtheria, tetanus, and acellular pertussis vaccine (DTaP).
A Script-Assisted Microscopy (SAM) Package to Improve Data Acquisition Rates on FEI Tecnai Electron Microscopes Equipped with Gatan CCD Cameras
Journal of Structural Biology. Oct, 2008 | Pubmed ID: 18621546
High throughput methods of data acquisition are advantageous for cryoelectron microscopy and single particle reconstruction as high-resolution structure determination requires thousands of particle images. We have developed a semi-automated data collection method that utilizes the scripting languages provided by FEI for their Tecnai User Interface (TUI) and by Gatan for their Digital Micrograph package. Our Script-Assisted Microscopy (SAM) method allows for the selection of multiple locations within a low magnification, search mode, micrograph and for subsequent automated imaging of these locations at a higher exposure magnification. The SAM approach permits the user to retain control over the microscope, while streamlining the most repetitive steps of collecting and evaluating micrographs. With SAM, we have found an average of 1000 micrographs can be collected per day on any grid type, either irregular homemade grids or prefabricated grids with regularly spaced holes. This rate of data collection represents a fivefold improvement over our manual collection rates. SAM provides an example of an individually tailored approach to data acquisition utilizing the scripting interfaces provided by the equipment manufacturers. The SAM method has proven valuable for determination of a subnanometer resolution cryoEM structure of DNA-dependent protein kinase catalytic subunit (DNA-PKcs), a 469kDa protein.
Journal of Virology. Oct, 2008 | Pubmed ID: 18667514
Flexible filamentous viruses make up a large fraction of the known plant viruses, but in comparison with those of other viruses, very little is known about their structures. We have used fiber diffraction, cryo-electron microscopy, and scanning transmission electron microscopy to determine the symmetry of a potyvirus, soybean mosaic virus; to confirm the symmetry of a potexvirus, potato virus X; and to determine the low-resolution structures of both viruses. We conclude that these viruses and, by implication, most or all flexible filamentous plant viruses share a common coat protein fold and helical symmetry, with slightly less than 9 subunits per helical turn.
The Pediatric Infectious Disease Journal. Nov, 2008 | Pubmed ID: 18833023
The frequency and duration of antibody responses after trivalent inactivated influenza vaccine (TIV) in young children are not well defined and assume greater importance with the expanded recommendations for vaccine use in children aged 6 months-5 years.
The Basic Helix-loop-helix Transcription Factor Olig2 is Critical for Reactive Astrocyte Proliferation After Cortical Injury
The Journal of Neuroscience : the Official Journal of the Society for Neuroscience. Oct, 2008 | Pubmed ID: 18945906
The mechanisms underlying the formation of the glial scar after injury are poorly understood. In this report, we demonstrate that after cortical injury Olig2 is upregulated in reactive astrocytes coincident with proliferation of these cells. Short-term lineage tracing studies with glial subtype-restricted transgenic reporter lines indicate that Olig2-expressing cells in the astroglial but not the oligodendroglial lineage are the essential source of reactive astrocytes. In addition, cortical Olig2 ablation results in a decrease in proliferation of reactive astrocytes in response to injury. Cell-type-specific mutagenesis indicates that Olig2 ablation in GFAP+ astrocytes and their precursors rather than in neuronal or oligodendroglial cells is responsible for the reduction of reactive astrocyte proliferation. Thus, our studies suggest that Olig2 is critical for postinjury gliosis.
Asymmetric Carbonyl-ene Reaction Catalyzed by Chiral N,N'-dioxide-nickel(II) Complex: Remarkably Broad Substrate Scope
Journal of the American Chemical Society. Nov, 2008 | Pubmed ID: 18980310
Highly enantioselective carbonyl-ene reaction of glyoxal derivatives and glyoxylate with various alkenes was accomplished using a novel nickel(II)-N,N'-dioxide complex under mild conditions, which facilitated the asymmetric synthesis of biologically interesting alpha-hydroxy carbonyl compounds. Various aromatic, aliphatic, and heteroaromatic glyoxal derivatives, as well as glyoxylate, could be tolerated in this system and afforded the corresponding adducts in excellent enantioselectivities (97->99% ee) with high yields. Moreover, the catalyst loading could even be decreased to 1 mol%, while the enantioselectivity was basically maintained.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics. Oct, 2008 | Pubmed ID: 18999401
We have studied the effect of memory on the evolution of the prisoner's dilemma game in square lattice networks. Based on extensive simulations, we found that the density of cooperators was enhanced by an increasing memory effect for most parameters. However, we also observed that the density of cooperators decreased with an increased memory effect in the case of a large memory and moderate temptation. It is interesting to note that memory makes cooperators immune from temptation. The strength of protection reaches its maximal value only for a moderate memory effect.
PloS One. 2008 | Pubmed ID: 19009021
Since 1999 GHESKIO, a large voluntary counseling and HIV testing center in Port-au-Prince, Haiti, has had an ongoing collaboration with the Haitian Ministry of Health to reduce the rate of mother to child HIV transmission. There are limited data on the ability to administer complex regimens for reducing mother to child transmission and on risk factors for continued transmission and infant mortality within programmatic settings in developing countries.
Sensitive Determination of 20(S)-protopanaxadiol in Rat Plasma Using HPLC-APCI-MS: Application of Pharmacokinetic Study in Rats
Journal of Pharmaceutical and Biomedical Analysis. Dec, 2008 | Pubmed ID: 19022601
20(S)-Protopanaxadiol (PPD), the main metabolite of protopanoxadiol type ginsenosides (e.g. Rg3 and Rh2), is a very promising anti-cancer drug candidate. To evaluate the pharmacokinetic property of PPD, we reported a reliable, sensitive and simple method utilizing liquid chromatography (HPLC)-atmospheric pressure chemical ionization-mass spectrometry (APCI-MS) to determine PPD. PPD and the internal standard, panoxadiol (PD) were extracted from plasma with acetic ether, separated on a C18 reverse column, and then analyzed by APCI-MS. Targeting fragment ion at m/z 425 for both PPD and PD was monitored in selected-ion monitoring (SIM) mode. PPD can be quantitatively determined at the concentration as low as 1 ng/mL using 200 microL plasma. And the sensitive method showed excellent linearity over a range from 1 to 1000 ng/mL, high recovery, accuracy and precision at the concentrations of 2.5, 100.0 and 1000.0 ng/mL, respectively. The method was successfully applied to pharmacokinetic study of PPD in rats. Pharmacokinetic parameters were calculated and absolute bioavailability of PPD was 36.8+/-12.4%, at least ten times higher than that of Rg3 and Rh2, indicating its good absorption in gastrointestinal tract. It was further suggested that PPD be a promising anti-cancer candidate and probably responsible for the observed pharmacological activity of Rg3 and Rh2.
PloS One. 2008 | Pubmed ID: 19050756
Using gene order as a phylogenetic character has the potential to resolve previously unresolved species relationships. This character was used to resolve the evolutionary history within the genus Prochlorococcus, a group of marine cyanobacteria.
A Minimally Invasive Alternative for Managing Large Pancreatic Duct Stones Using a Modified Expandable Metal Mesh Stent
Pancreatology : Official Journal of the International Association of Pancreatology (IAP) ... [et Al.]. 2009 | Pubmed ID: 19077461
Endoscopic clearance of large or impacted stones in the main pancreatic duct (MPD) remains a clinical challenge. In this study, we attempted to technically modify the metallic stent to facilitate the clearance of large pancreatic stones in 4 patients, hoping to lower the operative risks and shorten hospital stay.
Stejnihagin, a Novel Snake Metalloproteinase from Trimeresurus Stejnegeri Venom, Inhibited L-type Ca2+ Channels
Toxicon : Official Journal of the International Society on Toxinology. Feb, 2009 | Pubmed ID: 19114053
Snake venom metalloproteinases (SVMPs) mainly distribute in Crotalid and Viperid snake venom and are classified into the Reprolysin subfamily of the M12 family of metalloproteinases. Previous function investigations have suggested that SVMPs are the key toxins involved in a variety of snake venom-induced pathogenesis including systemic injury, local damage, hemorrhage, edema, hypotension, hypovolemia, inflammation and necrosis. However, up to now, there is no report on ion channels blocking activity about SVMPs. Here, from Trimeresurus stejnegeri venom we purified a component Stejnihagin containing a mixture of Stejnihagin-A and -B, with 86% sequences identity, both as members of SVMPs. In the study, whole-cell patch clamp and vessel tension measurement were employed to identify the effect of Stejnihagin on L-type Ca2+ channels and vessel contraction. The results show that Stejnihagin inhibited L-type Ca2+ channels in A7r5 cells with an IC50 about 37 nM and simultaneously blocked 60 mM K+-induced vessel contraction. Besides, the inhibitory effect of Stejnihagin on L-type Ca2+ channels was also independent of the enzymatic activity. This finding offers new insight into the snake venom metalloproteinase functions and provides a novel pathogenesis of T. stejnegeri venom. Furthermore, it may also provide a clue to study the structure-function relationship of animal toxins and voltage-gated Ca2+ channel.
BMC Bioinformatics. 2009 | Pubmed ID: 19208110
A phylogeny is the evolutionary history of a group of organisms. To date, sequence data is still the most used data type for phylogenetic reconstruction. Before any sequences can be used for phylogeny reconstruction, they must be aligned, and the quality of the multiple sequence alignment has been shown to affect the quality of the inferred phylogeny. At the same time, all the current multiple sequence alignment programs use a guide tree to produce the alignment and experiments showed that good guide trees can significantly improve the multiple alignment quality.
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi = Zhonghua Laodong Weisheng Zhiyebing Zazhi = Chinese Journal of Industrial Hygiene and Occupational Diseases. Jan, 2009 | Pubmed ID: 19224705
FAS -1,377 G/A Polymorphism is Associated with Cancer Susceptibility: Evidence from 10,564 Cases and 12,075 Controls
Human Genetics. May, 2009 | Pubmed ID: 19225810
Published data on the association between FAS -1,377 G/A polymorphism and cancer risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. A total of 17 studies including 10,564 cases and 12,075 controls were involved in this meta-analysis. Overall, significantly elevated cancer risk was associated with AA variant genotype when all the eligible studies were pooled into the meta-analysis (for AA vs GG: OR = 1.19; 95% CI = 1.01-1.40; P (heterogeneity) = 0.05; for recessive model: OR = 1.21; 95% CI = 1.04-1.41; P (heterogeneity) = 0.05). In the subgroup analysis by ethnicity, borderline statistically significantly increased risks were found among Asians for recessive model (OR = 1.20; 95% CI = 1.00-1.45; P (heterogeneity) = 0.01). In the subgroup analysis by population-based controls or hospital-based controls, statistically significantly increased risks were found among groups with population-based controls for AA versus GG (OR = 1.27; 95% CI = 1.02-1.58; P (heterogeneity) = 0.05) and recessive model (OR = 1.25; 95% CI = 1.00-1.59; P (heterogeneity) = 0.01). For breast cancer, borderline statistically significantly increased risks were found for AA versus GG (OR = 1.29; 95% CI = 1.00-1.67; P (heterogeneity) = 0.41). In summary, this meta-analysis suggests that the FAS -1,377 G/A polymorphism is associated with cancer susceptibility.
The Annals of Thoracic Surgery. Mar, 2009 | Pubmed ID: 19231385
There is no agreement whether off-pump coronary artery bypass (OPCAB) can reduce mortality, rates of stroke, myocardial infarction, or revascularization when compared with conventional coronary artery bypass (CCAB). We performed a meta-analysis comparing off-pump coronary artery bypass with conventional coronary artery bypass in randomized controlled trials.
Zhejiang Da Xue Xue Bao. Yi Xue Ban = Journal of Zhejiang University. Medical Sciences. Jan, 2009 | Pubmed ID: 19253431
To investigate the effect of wt p53 gene transfection on the sensitivity of hyperthermia in C6 glioma.
ATG16L1 T300A Polymorphism and Crohn's Disease Susceptibility: Evidence from 13,022 Cases and 17,532 Controls
Human Genetics. Jun, 2009 | Pubmed ID: 19337756
Many studies have reported the association between the autophagy-related 16-like 1 gene (ATG16L1) T300A polymorphism (rs2241880) and Crohn's disease (CD) susceptibility, but the results were inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. A total of 24 studies including 13,022 cases and 17,532 controls were included in this meta-analysis. Logistic regression analysis indicated that the ATG16L1 T300A polymorphism was associated with CD risk in Caucasians (P < 0.01). The pooled estimations of OR(1) (GG vs. AA) and OR(2) (GA vs. AA) in Caucasian studies by Bayesian meta-analysis method was [1.87, 95% confidence interval (CI) 1.69-2.05] and (1.39, 95% CI 1.27-1.51), respectively. The mode of heritance of the G allele was most likely to be co-dominant in Caucasians. However, no significant association was found in Asians. This meta-analysis suggests that the G allele of ATG16L1 T300A is a low-penetrant gene for developing CD in Caucasians.
Journal of Structural Biology. Jul, 2009 | Pubmed ID: 19361558
Electron tomography has become a uniquely powerful tool for investigating the structures of individual cells, viruses, and macromolecules. Data collection is, however, time consuming and requires expensive instruments. To optimize productivity, we have incorporated one of the existing tilt-series acquisition programs, UCSF Tomo, into the well-developed automatic electron microscopy data collection package Leginon to enable fully automatic, sequential tilt-series acquisition. Here we describe how UCSF Tomo was integrated into Leginon, what users must do to set up a data collection session, how the automatic collection proceeds, how archived data about the process can be accessed and used, and how the software has been tested.
A Control Approach to Cross-coupling Compensation of Piezotube Scanners in Tapping-mode Atomic Force Microscope Imaging
The Review of Scientific Instruments. Apr, 2009 | Pubmed ID: 19405668
In this article, an approach based on the recently developed inversion-based iterative control (IIC) to cancel the cross-axis coupling effect of piezoelectric tube scanners (piezoscanners) in tapping-mode atomic force microscope (AFM) imaging is proposed. Cross-axis coupling effect generally exists in piezoscanners used for three-dimensional (x-y-z axes) nanopositioning in applications such as AFM, where the vertical z-axis movement can be generated by the lateral x-y axes scanning. Such x/y-to-z cross-coupling becomes pronounced when the scanning is at large range and/or at high speed. In AFM applications, the coupling-caused position errors, when large, can generate various adverse effects, including large imaging and topography distortions, and damage of the cantilever probe and/or the sample. This paper utilizes the IIC technique to obtain the control input to precisely track the coupling-caused x/y-to-z displacement (with sign-flipped). Then the obtained input is augmented as a feedforward control to the existing feedback control in tapping-mode imaging, resulting in the cancellation of the coupling effect. The proposed approach is illustrated through two exemplary applications in industry, the pole-tip recession examination, and the nanoasperity measurement on hard-disk drive. Experimental results show that the x/y-to-z coupling effect in large-range (20 and 45 microm) tapping-mode imaging at both low to high scan rates (2, 12.2 to 24.4 Hz) can be effectively removed.
Bioresource Technology. Oct, 2009 | Pubmed ID: 19423334
This study used the fungus, Phanerochaete chrysosporium, to pretreat cotton stalks with two methods, shallow stationary and agitated cultivation, at three supplemental salt concentrations. Pretreatment efficiencies were compared by evaluating lignin degradation, solid recovery and carbohydrate availability over a 14-day period. Shallow stationary cultivation with no salts gave 20.7% lignin degradation along with 76.3% solid recovery and 29.0% carbohydrate availability. The highest lignin degradation of 33.9% at a corresponding solid recovery and carbohydrate availability of 67.8% and 18.4%, respectively, was obtained through agitated cultivation with Modified NREL salts. Cultivation beyond 10 days did not significantly increase lignin degradation during 14 days of pretreatment. Manganese addition during shallow stationary and agitated cultivation resulted in higher solid recoveries of over 80% but lower lignin degradation. Although agitated cultivation resulted in better delignification, results indicate that pretreatment under submerged shallow stationary conditions provides a better balance between lignin degradation and carbohydrate availability.
Journal of Nanoscience and Nanotechnology. Feb, 2009 | Pubmed ID: 19441382
Using thermal fluctuation induced oscillation, spring constant of different types of reference cantilevers have been measured by heterodyne laser interferometer with traceable displacement at a resolution of 2.6 x 10(-15) m/(Hz)1/2. This method provides precise measurements of the scanning probe cantilevers with spring constants ranging from mN/m to kN/m. The accuracy of the spring constant was verified by geometric calculation of the reference levers and measurement by electrostatic force balance. Factors that affect the accuracy impact of thermal tune background have been thoroughly investigated.
Ursodeoxycholic Acid in Primary Sclerosing Cholangitis: Meta-analysis of Randomized Controlled Trials
Hepatology Research : the Official Journal of the Japan Society of Hepatology. Sep, 2009 | Pubmed ID: 19467021
Aims: The effect of ursodeoxycholic acid (UDCA) treatment on survival and liver histological progression of primary sclerosing cholangitis (PSC) remains uncertain. The aim of the present study was to evaluate the effect and safety of UDCA in PSC. Methods: Electronic databases including Medline, Embase, Cochrane controlled trials register, Web of Science and PubMed (updated to January 2009) and manual bibliographical searches were carried out. A meta-analysis of all randomized controlled trials (RCT) comparing UDCA with placebo or no treatment was carried out. Results: Eight RCT including 465 patients were assessed. UDCA could significantly improve liver biochemistry, but had no effect on pruritus and fatigue. Meta-analysis of the included RCT showed UDCA had no significant effect on the incidence of death, liver transplantation, and death and/or liver transplantation. However, a significant difference for the incidence of histological improvement was found between the two groups (odds ratio [OR], 9.19; 95% CI: 0.98, 86.15; P = 0.05). Meta-analysis also indicated a reduction trend of histological deterioration and an improvement trend of cholangiographic changes. These trends were constant in the sensitivity analyses. Conclusion: The meta-analysis found that UDCA can improve liver biochemistry and there is a trend towards improvement in liver histology and cholangiography, but has no effect on survival free of transplantation.
Milder Liver Cirrhosis and Loss of Serum HBeAg Do Not Imply Lower Risk for Hepatocellular Carcinoma Development in HBV-related Cirrhosis
Medical Science Monitor : International Medical Journal of Experimental and Clinical Research. Jun, 2009 | Pubmed ID: 19478697
Serum HBeAg status and liver cirrhosis severity at the time of diagnosis of hepatocellular carcinoma (HCC) in hepatitis B virus (HBV)-related cirrhosis remain inconclusive. The aim was to investigate the status of HBeAg and cirrhosis severity at the time of HCC development in the natural history of HBV-related cirrhosis in mainland China.
ACS Nano. Jun, 2009 | Pubmed ID: 19545169
Metal catalysts are widely used for nanowire (NW) growth and are one of the essential parameters that dictate the crystal growth phenomena, thus controlling the NW's morphology. Although extensive research has been conducted on catalyst effects, the catalyst drifting effect is generally underestimated for controlling the morphology of nanostructures grown at a relatively high temperature. In this paper, we report a discovery of Zn cluster drifting phenomenon during ZnO vapor deposition. Because of the deposition of ZnO along the drifting path, the dynamic process of cluster drifting could be visualized after the growth. This phenomenon provides a sound explanation of the formation of randomly orientated ZnO nanowall networks. The cluster drifting direction could be intentionally directed by designing the surface inclination, through which a partially parallel aligned ZnO vertical nanofin array was created. This 3D nanoarchitecture would possibly provide a novel configuration for designing high performance integrated nanodevices. The drifting of Zn clusters could be a general phenomenon for most metal catalysts and would provide a new insight into nanofabrication and nanodevice development.
PloS One. 2009 | Pubmed ID: 19562076
Methanogens are a phylogenetically diverse group belonging to Euryarchaeota. Previously, phylogenetic approaches using large datasets revealed that methanogens can be grouped into two classes, "Class I" and "Class II". However, some deep relationships were not resolved. For instance, the monophyly of "Class I" methanogens, which consist of Methanopyrales, Methanobacteriales and Methanococcales, is disputable due to weak statistical support. In this study, we use MSOAR to identify common orthologous genes from eight methanogen species and a Thermococcale species (outgroup), and apply GRAPPA and FastME to compute distance-based gene order phylogeny. The gene order phylogeny supports two classes of methanogens, but it differs from the original classification of methanogens by placing Methanopyrales and Methanobacteriales together with Methanosarcinales in Class II rather than with Methanococcales. This study suggests a new classification scheme for methanogens. In addition, it indicates that gene order phylogeny can complement traditional sequence-based methods in addressing taxonomic questions for deep relationships.
Skeletonization with an Ultrasonic Scalpel is As Safe As a Non-skeletonized Dissection in Preserving the Endothelial Function of the Human Gastroepiploic Artery
Interactive Cardiovascular and Thoracic Surgery. Feb, 2009 | Pubmed ID: 19000990
The right gastroepiploic artery (GEA) is frequently used as another in situ artery, other than the internal thoracic artery (ITA) in coronary artery bypass grafting (CABG). Skeletonizing the graft with an ultrasonic scalpel is now regarded as a useful technique; however, this technique may damage the endothelial function during harvesting the graft resulting in postoperative graft stenosis or occlusion. In the present study, GEA segments from nine patients were excised in both a skeletonized and non-skeletonized manner with an ultrasonic scalpel, and then were transported to the laboratory. The vessels were trimmed as rings, and were allotted to the group of skeletonized or non-skeletonized, accordingly. The force development in response to 1 mumol/l norepinephrine did not differ between the skeletonized and non-skeletonized groups. Endothelium-dependent relaxation induced by either acetylcholine or bradykinin was not impaired in the skeletonized group in comparison to the non-skeletonized group. No significant difference was observed in endothelium-independent relaxation elicited by sodium nitroprusside. Therefore, the skeletonization of the GEA with an ultrasonic scalpel was thus found to be as safe as a non-skeletonized dissection in preserving the vascular contractile ability or endothelium-dependent and -independent relaxation of the graft.
Insulin Receptor Substrate-1 Suppresses Transforming Growth Factor-beta1-mediated Epithelial-mesenchymal Transition
Cancer Research. Sep, 2009 | Pubmed ID: 19738073
We investigated the regulatory effect of insulin receptor substrate-1 (IRS-1) on transforming growth factor-beta1 (TGF-beta1)-induced epithelial-mesenchymal transition (EMT). TGF-beta1-induced EMT and cell migration in A549 cells are associated with a decrease in IRS-1 tyrosine phosphorylation and protein levels. Tissue microarray analysis of human lung carcinoma shows a correlation between IRS-1 protein levels and E-cadherin protein levels. High IRS-1 levels coexist with high E-cadherin levels, whereas low IRS-1 levels coexist with low E-cadherin levels, implying a possibility that IRS-1 protein levels may be linked with EMT. Surprisingly, overexpression of IRS-1 in A549 cells completely blocked TGF-beta1-induced EMT and cell migration, inhibited TGF-beta1-mediated expression of snail and slug genes, and abolished TGF-beta1-mediated repression of E-cadherin promoter activity. In contrast, IRS-1 knockdown by RNAi increased the expression of snail and slug genes and induced EMT. Inhibition of protein tyrosine phosphatase with sodium vanadate, which greatly increased the levels of tyrosine-phosphorylated IRS-1, suppressed TGF-beta1-induced actin remodeling and cell morphologic changes. These results show for the first time that TGF-beta1 induces EMT through mechanisms involving the modulation of IRS-1 signaling, and that IRS-1 functions as a critical EMT suppressor that suppresses TGF-beta1-induced EMT via inhibition of snail and slug expression.
Journal of Zhejiang University. Science. B. Jul, 2009 | Pubmed ID: 19585674
Granulomatous hypophysitis (GRH) is extremely rare and commonly presents with chronic inflammatory of the enlarged pituitary gland. In our study, 66-year-old and 57-year-old women, both Chinese, were diagnosed with GRH presenting preoperatively definite imageology characters as pituitary adenoma. The 66-year-old woman presented with a year of headache, half a year of gradual decrease of visual acuity, and one month of right ptosis. Serum prolactin level was slightly elevated. Screening computed tomography (CT) scanning revealed typical low density mass found on the enlarged sella, which demonstrated invasive extension from the sella to the right cavernous sinus by contrast enhanced magnetic resonance imaging (MRI). Consequently, the patient was diagnosed with probable invasive pituitary adenoma. The other 57-year-old woman complained a light headache and had been previously treated as nonfunctional pituitary adenoma in other hospital. Finally these two patients underwent transsphenoidal microsurgery and were diagnosed with GRH according to postoperative histopathology. They then were treated with steroid. During the follow-up, the clinical symptoms such as headache, visual damage, and ptosis vanished, and the mass of the sellae dramatically shrank on repeated MR images. Clinically and radiologically, GRH is a rare sellar entity easily to be misdiagnosed as a pituitary adenoma. Trans-sphenoidal surgery can decompress the optical nerve or oculomotornerve as a therapeutic strategy, and support biopsy or further pathological diagnosis. However, the hormonal therapy should be emphasized both as diagnostic and therapeutic strategies. Conservative and tentative steroid treatment should be performed in preoperative period without acute nerve damage.
Enantioselective Michael Addition of Malononitrile to Chalcones Catalyzed by a Simple Quinine-Al(O(i)Pr)(3) Complex: a Simple Method for the Synthesis of a Chiral 4H-pyran Derivative
Chemical Communications (Cambridge, England). Aug, 2009 | Pubmed ID: 19641818
Enantioselective Michael addition of malononitrile to chalcones was catalyzed by a simple quinine and Al(O(i)Pr)(3) complex and products were obtained in good ee as well as high yields, which facilitated the asymmetric synthesis of a biologically active 4H-pyran compound.
Bioresource Technology. Dec, 2009 | Pubmed ID: 19665372
Coastal Bermuda grass (GBG) was pretreated using an autohydrolysis process with different temperatures and times, and the pretreated materials were enzymatically hydrolyzed using a mixture of cellulase, xylanase and beta-glucosidase with different enzyme loadings to evaluate sugar yields. Compared with untreated CBG, autohydrolysis pretreatments at all elevated temperatures and residence times tested enhanced enzymatic digestibility of both cellulose and hemicellulose. Increasing the temperature and residence time also helps to solubilize hemicelluloses, with 83.3% of the hemicelluloses solubilized at 170 degrees C for 60 min treatment. However, higher temperatures and longer times resulted in an overall lower sugar recovery when considering monosaccharides in the prehydrolyzate combined with the enzyme hydrolyzate. Autohydrolysis at 150 degrees C for 60 min provided the highest overall sugar yield for the entire process. A total of 43.3 g of sugars, 70% of the theoretical sugar yield, can be generated from 100g CBG, 15.0 g of monosaccharide in the prehydrolyzate and 28.3 g in the enzyme hydrolyzate. The conversion efficiency could be further improved by optimizing enzyme dosages and xylanases:cellulases ratio and pretreatment conditions to minimize sugar degradation.
Zhonghua Liu Xing Bing Xue Za Zhi = Zhonghua Liuxingbingxue Zazhi. Nov, 2009 | Pubmed ID: 20193576
To investigate the source of the first human case of avian influenza A (H5N1) infection in Beijing.
The Journal of Experimental Medicine. Nov, 2009 | Pubmed ID: 19887393
Both class switch recombination (CSR) and somatic hypermutation (SHM) require transcription and the trans-acting factor activation-induced cytidine deaminase (AID), and must be up-regulated during antigen-dependent differentiation of B lymphocytes. To test the role of the heavy chain 3' enhancers in both CSR and SHM, we used a BAC transgene of the entire heavy chain constant region locus. Using Cre-loxP recombination to delete a 28-kb region that contains the four known 3' heavy chain enhancers, we isolated lines of BAC transgenic mice with an intact heavy chain locus and paired lines in the same chromosomal insertion site lacking the 3' enhancers. Intact heavy chain transgenes undergo CSR to all heavy chain genes and mutate their transgenic VDJ exon. In paired transgenes lacking the 3' enhancer region, CSR to most heavy chain genes is reduced to approximately 1% of the levels for intact heavy chain loci; SHM is also reduced. Finally, we find that in B cells with a transgene lacking the 3' enhancers, interchromosomal recombination between the transgenic VDJ exon and the endogenous heavy chain C genes is more easily detected than CSR within the transgene.
[Correlation Analysis of Vascular Endothelial Growth Factor-C Expression and Clinicopathology in Breast Cancer]
Nan Fang Yi Ke Da Xue Xue Bao = Journal of Southern Medical University. Nov, 2009 | Pubmed ID: 19923084
To investigate the expressions of vascular endothelial growth factor-C (VEGF-C), C-erbB-2, p53, estrogen receptor (ER), and progesterone receptor (PR) in breast cancer tissue and their clinical significance.
The Arabidopsis DCR Encoding a Soluble BAHD Acyltransferase is Required for Cutin Polyester Formation and Seed Hydration Properties
Plant Physiology. Dec, 2009 | Pubmed ID: 19828672
The cuticle covering every plant aerial organ is largely made of cutin that consists of fatty acids, glycerol, and aromatic monomers. Despite the huge importance of the cuticle to plant development and fitness, our knowledge regarding the assembly of the cutin polymer and its integration in the complete cuticle structure is limited. Cutin composition implies the action of acyltransferase-type enzymes that mediate polymer construction through ester bond formation. Here, we show that a member of the BAHD family of acyltransferases (DEFECTIVE IN CUTICULAR RIDGES [DCR]) is required for incorporation of the most abundant monomer into the polymeric structure of the Arabidopsis (Arabidopsis thaliana) flower cutin. DCR-deficient plants display phenotypes that are typically associated with a defective cuticle, including altered epidermal cell differentiation and postgenital organ fusion. Moreover, levels of the major cutin monomer in flowers, 9(10),16-dihydroxy-hexadecanoic acid, decreased to an almost undetectable amount in the mutants. Interestingly, dcr mutants exhibit changes in the decoration of petal conical cells and mucilage extrusion in the seed coat, both phenotypes formerly not associated with cutin polymer assembly. Excessive root branching displayed by dcr mutants and the DCR expression pattern in roots pointed to the function of DCR belowground, in shaping root architecture by influencing lateral root emergence and growth. In addition, the dcr mutants were more susceptible to salinity, osmotic, and water deprivation stress conditions. Finally, the analysis of DCR protein localization suggested that cutin polymerization, possibly the oligomerization step, is partially carried out in the cytoplasmic space. Therefore, this study extends our knowledge regarding the functionality of the cuticular layer and the formation of its major constituent the polymer cutin.
[Developmental Regulation of Long Term Potentiation at Layer II/III to II/III Synapses of Rat Visual Cortex.]
Sheng Li Xue Bao : [Acta Physiologica Sinica]. Oct, 2009 | Pubmed ID: 19847367
In the present research, patch-clamp whole-cell recording was used to study the developmental changes of the internal horizontal synaptic plasticity in layer II/III of rats' primary visual cortices. Pairing stimulation was used to induce long term potentiation (LTP) of neurons in layer II/III from layer II/III and layer IV. The data indicate that: (1) Responses of layer II/III neurons can be evoked independently at II/III-II/III and IV-II/III synapses by horizontal and vertical stimulations; (2) LTP can be induced from neurons in the layer II/III by horizontal tetanic stimulation at II/III-II/III synapses till postnatal day12 (P12, before eyes open); (3) Meanwhile, only short term potentiation (STP) at IV-II/III synapses can be induced by horizontal tetanic stimulation before eyes open; (4) After P12, a robust LTP at IV-II/III synapses can be induced by horizontal tetanic stimulation; (5) At P14, when vertical and horizontal tetanic stimulations were given to the same neuron, the LTP at IV-II/III synapses was weaker than that induced by vertical stimulation alone, suggesting that vertical synaptic modification was negatively regulated by horizontal inputs when two-direction synaptic inputs were presented at the same time; (6) Spontaneous responses of AMPA receptors (AMPARs) in the layer II/III neuron of rats' primary visual cortices are regulated by the development. The frequency of AMPARs-mediated postsynaptic currents was at a low level before eyes open, increased sharply at P12-P14, and slightly decreased after P18. And the amplitude of spontaneous AMPARs currents slowly decreased after P12. The results demonstrated that both the strength of horizontal synaptic modification and the effects of horizontal inputs on the vertical synaptic connection are regulated by the development. II/III-II/III synaptic communication has dual effects on the IV-II/III synapses, which may be involved in a competitive machinery of neural circuitry maturation and the formation of visual function columns.
Tobacco Control. Feb, 2010 | Pubmed ID: 19850552
To compare the new tobacco tax structure effective from May 2009 with the tax structure before May 2009 and to analyse its potential impact.
Journal of Nanoscience and Nanotechnology. Aug, 2010 | Pubmed ID: 21125915
The Ag-Ga/poly(methyl methacrylate) nanoparticles were prepared in-situ by emulsion polymerization method under ultrasonic irradiation without any initiators or metal reductant. HRTEM, EDS and XRD experiments were performed to characterize the nanoparticles. The results indicated that the nanocomposite particles possessed core-shell structure with diameters of 80-200 nm, as well as excellent monodispersity. The phenomenon that the polymer forms the shell via layer-by-layer self-assembly was found. XRD proved the existence of Ag0.72Ga0.28 and the probability of new Ag-Ga alloy because of two unknown diffraction peaks.
Scientific Publications in Anesthesiology Journals from Mainland China, Taiwan, and Hong Kong: a 10-year Survey of the Literature
Anesthesia and Analgesia. Mar, 2010 | Pubmed ID: 19955511
The past 20 yr have seen significant growth in China's role in the international community. This same growth and international presence is occurring in the field of anesthesiology. The research status in anesthesiology among Chinese individuals in the 3 major regions of China--mainland China, Hong Kong, and Taiwan--is unknown. We analyzed articles published in peer-reviewed international anesthesiology journals cited by both PubMed and Science Citation Index from these 3 regions.
Tobacco Control. Feb, 2010 | Pubmed ID: 20008158
To identify key economic issues involved in raising the tobacco tax and to recommend possible options for tobacco tax reform in China.
The Arabidopsis DSO/ABCG11 Transporter Affects Cutin Metabolism in Reproductive Organs and Suberin in Roots
Molecular Plant. May, 2010 | Pubmed ID: 20035035
Apart from its significance in the protection against stress conditions, the cuticular cover is essential for proper development of the diverse surface structures formed on aerial plant organs. This layer mainly consists of a cutin matrix, embedded and overlaid with cuticular waxes. Following their biosynthesis in epidermal cells, cutin and waxes were suggested to be exported across the plasma membrane by ABCG-type transporters such as DSO/ABCG11 to the cell wall and further to extracellular matrix. Here, additional aspects of DSO/ABCG11 function were investigated, predominantly in reproductive organs, which were not revealed in the previous reports. This was facilitated by the generation of a transgenic DSO/ABCG11 silenced line (dso-4) that displayed relatively subtle morphological and chemical phenotypes. These included altered petal and silique morphology, fusion of seeds, and changes in levels of cutin monomers in flowers and siliques. The dso-4 phenotypes corresponded to the strong DSO/ABCG11 gene expression in the embryo epidermis as well as in the endosperm tissues of the developing seeds. Moreover, the DSO/ABCG11 protein displayed polar localization in the embryo protoderm. Transcriptome analysis of the dso-4 mutant leaves and stems showed that reduced DSO/ABCG11 activity suppressed the expression of a large number of cuticle-associated genes, implying that export of cuticular lipids from the plasma membrane is a rate-limiting step in cuticle metabolism. Surprisingly, root suberin composition of dso-4 was altered, as well as root expression of two suberin biosynthetic genes. Taken together, this study provides new insights into cutin and suberin metabolism and their role in reproductive organs and roots development.
The Genetic Association of Vitamin D Receptor Polymorphisms and Cervical Spondylotic Myelopathy in Chinese Subjects
Clinica Chimica Acta; International Journal of Clinical Chemistry. Jun, 2010 | Pubmed ID: 20144597
The association of vitamin D receptor (VDR) gene polymorphisms to the lumbar degenerative disc disease has been previously studied; however, the role of VDR gene polymorphisms in cervical spondylosis remains unknown.
The Review of Scientific Instruments. Feb, 2010 | Pubmed ID: 20192481
We demonstrated a microfluidic refractometer with an integrated high resolution transmission grating. This grating was fabricated by UV nanoimprinting on the end facet of a multimode optical fiber which was then placed in the plan of the microfluidic device and perpendicular to a microchannel. On the opposite side of the channel, three cleaved optical fibers were added for the light collection of the zeroth and the +/- first diffraction orders. A white light source was used for illumination and the diffraction beams were analyzed with a minispectrometer. The transmission grating was merged in the sample solution of the channel, providing a refractive index-dependent diffraction efficiency. As expected, the diffraction efficiency of the zeroth and the +/- first diffraction orders are different, both being reliable for the refractive index monitoring. Such a white source and multibeam diffraction analysis also allows monitoring the sample absorption or fluorescence, thereby providing a more accurate determination of the sample refraction index.
Ins(1,4,5)P3 Interacts with PIP2 to Regulate Activation of TRPC6/C7 Channels by Diacylglycerol in Native Vascular Myocytes
The Journal of Physiology. May, 2010 | Pubmed ID: 20211974
We investigated synergism between inositol 1,4,5-trisphosphate (Ins(1,4,5)P(3)) and diacylglycerol (DAG) on TRPC6-like channel activity in rabbit portal vein myocytes using single channel recording and immunoprecipitation techniques. Ins(1,4,5)P(3) at 10 microm increased 3-fold TRPC6-like activity induced by 10 microm 1-oleoyl-2-acetyl-sn-glycerol (OAG), a DAG analogue. Ins(1,4,5)P(3) had no effect on OAG-induced TRPC6 activity in mesenteric artery myocytes. Anti-TRPC6 and anti-TRPC7 antibodies blocked channel activity in portal vein but only anti-TRPC6 inhibited activity in mesenteric artery. TRPC6 and TRPC7 proteins strongly associated in portal vein but only weakly associated in mesenteric artery tissue lysates. Therefore in portal vein the conductance consists of TRPC6/C7 subunits, while OAG activates a homomeric TRPC6 channel in mesenteric artery myocytes. Wortmannin at 20 microm reduced phosphatidylinositol 4,5-bisphosphate (PIP(2)) association with TRPC6 and TRPC7, and produced a 40-fold increase in OAG-induced TRPC6/C7 activity. Anti-PIP(2) antibodies evoked TRPC6/C7 activity, which was blocked by U73122, a phospholipase C inhibitor. DiC8-PIP(2), a water-soluble PIP(2) analogue, inhibited OAG-induced TRPC6/C7 activity with an IC(50) of 0.74 microm. Ins(1,4,5)P(3) rescued OAG-induced TRPC6/C7 activity from inhibition by diC8-PIP(2) in portal vein myocytes, and this was not prevented by the Ins(1,4,5)P(3) receptor antagonist heparin. In contrast, Ins(1,4,5)P(3) did not overcome diC8-PIP(2)-induced inhibition of TRPC6 activity in mesenteric artery myocytes. 2,3,6-Tri-O-butyryl-Ins(1,4,5)P(3)/AM (6-Ins(1,4,5)P(3)), a cell-permeant analogue of Ins(1,4,5)P(3), at 10 microm increased TRPC6/C7 activity in portal vein and reduced association between TRPC7 and PIP(2), but not TRPC6 and PIP(2). In contrast, 10 microm OAG reduced association between TRPC6 and PIP(2), but not between TRPC7 and PIP(2). The present work provides the first evidence that Ins(1,4,5)P(3) modulates native TRPC channel activity through removal of the inhibitory action of PIP(2) from TRPC7 subunits.
Transarterial Chemoembolization in Combination with Percutaneous Ablation Therapy in Unresectable Hepatocellular Carcinoma: a Meta-analysis
Liver International : Official Journal of the International Association for the Study of the Liver. May, 2010 | Pubmed ID: 20331507
Recent evidence suggests that transcatheter arterial chemoembolization (TACE) combined with radiofrequency ablation (RFA) or a percutaneous ethanol injection (PEI) may have a synergistic effect in treating hepatocellular carcinoma (HCC). The aim of the current meta-analysis was to identify the survival benefits of TACE combined with percutaneous ablation (PA) therapy (RFA or PEI) for unresectable HCC compared with those of TACE or PA alone.
BMC Bioinformatics. 2010 | Pubmed ID: 20370914
In recent years, gene order data has attracted increasing attention from both biologists and computer scientists as a new type of data for phylogenetic analysis. If gene orders are viewed as one character with a large number of states, traditional bootstrap procedures cannot be applied. Researchers began to use a jackknife resampling method to assess the quality of gene order phylogenies.
Lab on a Chip. May, 2010 | Pubmed ID: 20390138
Cell adhesion and motility depend strongly on the interactions between cells and cell culture substratum. To observe the cell morphology at the interface between cells and artificial substratum or patterned surfaces, we have developed a technique named reversed cell imprinting. After culture and chemical fixation of the cells on a patterned hole array, a liquid polymer was poured on and UV cured, allowing taking off the cell-polymer assembly for a direct observation of the underside cell surface using atomic force microscopy. As expected, we observed local deformation of the cell membrane in the hole area with a penetration depth strongly dependent on the size and depth of the hole as well as the culture time. Quantitative analyses of Hela cells on patterned surfaces of polydimethylsiloxane (PDMS) revealed that the penetration was also position dependent over the cell attachment area due to the non-homogeneous distribution of the membrane stress. With the increase of the culture time, the penetration depth was reduced, in a close correlation with the increase of the cell spreading area. Nevertheless, both cell seeding and adhesion efficiency on high density hole arrays could be significantly increased comparing to that on a smooth surface. Patterned substrates are increasingly required to produce and interrogate new biomaterials for therapeutic benefit. Overall, this work suggests a strategy to endow conventional imaging methods with added functionality to enable easy observation of the underside cell morphology on topographic patterns.
The Journal of Clinical Investigation. May, 2010 | Pubmed ID: 20407211
Brain-derived neurotrophic factor (BDNF) activates the receptor tropomyosin-related kinase B (TrkB) with high potency and specificity, promoting neuronal survival, differentiation, and synaptic function. Correlations between altered BDNF expression and/or function and mechanism(s) underlying numerous neurodegenerative conditions, including Alzheimer disease and traumatic brain injury, suggest that TrkB agonists might have therapeutic potential. Using in silico screening with a BDNF loop-domain pharmacophore, followed by low-throughput in vitro screening in mouse fetal hippocampal neurons, we have efficiently identified small molecules with nanomolar neurotrophic activity specific to TrkB versus other Trk family members. Neurotrophic activity was dependent on TrkB and its downstream targets, although compound-induced signaling activation kinetics differed from those triggered by BDNF. A selected prototype compound demonstrated binding specificity to the extracellular domain of TrkB. In in vitro models of neurodegenerative disease, it prevented neuronal degeneration with efficacy equal to that of BDNF, and when administered in vivo, it caused hippocampal and striatal TrkB activation in mice and improved motor learning after traumatic brain injury in rats. These studies demonstrate the utility of loop modeling in drug discovery and reveal what we believe to be the first reported small molecules derived from a targeted BDNF domain that specifically activate TrkB.We propose that these compounds constitute a novel group of tools for the study of TrkB signaling and may provide leads for developing new therapeutic agents for neurodegenerative diseases.
ACS Applied Materials & Interfaces. Apr, 2010 | Pubmed ID: 20423122
We report a simple but straightforward approach to produce nanofiber scaffolds with incorporated protein gradient for cell culture studies. Standard electrospinning technique was used to fabricate a high-porosity random fiber matrix. Protein molecules were then deposited in the fiber matrix by a controlled filling method, allowing the generation of a concentration gradient on the sample. When cultured with NIH 3T3 cells, it was found that the cell population on the fiber matrix depends strongly on the protein concentration. The cell morphology observation also showed the effect of the hybrid system containing both a fibrillar network and surface-coated protein gradient, revealing a different behavior of cell spreading in comparison with the experimental data of cell culture without fibers or without protein gradient.
Liposome Combined Porous Beta-TCP Scaffold: Preparation, Characterization, and Anti-biofilm Activity
Drug Delivery. Aug, 2010 | Pubmed ID: 20429845
The objective of this study was to design a novel artificial bone scaffold for therapy and prevention of refractory bacterial infection. Porous beta-tricalcium phosphate (beta-TCP) scaffold was combined with liposomal gentamicin (GS) to form a novel complex drug carrier. The liposome combined beta-TCP scaffold (LCS) was characterized for its liposome binding rate, drug loading, and micromorphology. The anti-biofilm activity of LCS was evaluated by Staphylococcus aureus biofilm in vitro. The drug release from LCS was recognized as an initial high dose of liposomal GS released from the matrix and a further sustained release of free GS from the liposome, respectively, and it is an ideal release pattern for treatment and prevention of post-operative osteomyelitis. The release kinetics was influenced by variation of particle size of liposome. LCS displayed a potential anti-biofilm activity even in the lowest GS concentration (2.5 microg/mL), and the regrowth time was extended from 5.0 h to 9.5 h. At a higher dosage range, the highest anti-biofilm activity was achieved by LCS with liposomal particle size of 800 nm. In conclusion, the development of LCS showed a new pathway for controlled delivery of liposomal antibiotics for treatment of osteomyelitis caused by persistent bacterial infection.
Hydrodynamics-based Transfection of Plasmid Encoding Receptor Activator for Nuclear Factor Kappa B-Fc Protects Against Hepatic Ischemia/reperfusion Injury in Mice
Liver Transplantation : Official Publication of the American Association for the Study of Liver Diseases and the International Liver Transplantation Society. May, 2010 | Pubmed ID: 20440770
Hepatic ischemia/reperfusion (I/R) injury is very important in transplant surgery. To study the mechanism of receptor activator for nuclear factor kappa B-Fc (RANK-Fc) in protection against I/R injury, 90 male BALB/c mice were randomly divided into 3 groups: a phosphate-buffered saline (PBS) (sham) group, a pLNCX2-IRES-eGFP+I/R (Negative-control) group (where IRES means internal ribosome entry site and eGFP means enhanced green fluorescent protein), and a pLNCX2-RANK-Fc-IRES-eGFP+I/R (RANK-Fc) group. All mice were injected with 2.5 mL of PBS (with or without plasmids) within 6 seconds via the tail vein. After 3 days, hepatic I/R was induced under warm conditions by partial occlusion of the left and median lobes for 90 minutes followed by various periods of reperfusion. Hepatic injury was assessed by the levels of liver aminotransferases and histopathology. Tumor necrosis factor alpha, interleukin 6, and interleukin 1beta were measured by enzyme-linked immunosorbent assay, whereas RANK-Fc, phospho-c-Jun, c-Jun N-terminal kinase (JNK), hypoxia inducible factor 1 alpha (HIF-1alpha), nuclear p65, and total p65 were assessed with western blotting. Apoptosis was identified by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling. RANK-Fc was efficiently expressed in the liver. In comparison with the negative-control group, RANK-Fc reduced nuclear factor kappa B (NF-kappaB) p65 nuclear translocation, JNK phosphorylation, and HIF-1alpha expression during I/R. RANK-Fc effectively suppressed proinflammatory cytokine expression. The results indicated that RANK-Fc could protect against hepatic I/R injury in mice at least in part via the inhibition of the proinflammatory NF-kappaB pathway as well as proapoptotic JNK and HIF-1alpha pathway activation.
PDZ Protein Mediated Activity-dependent LTP/LTD Developmental Switch at Rat Retinocollicular Synapses
American Journal of Physiology. Cell Physiology. Jun, 2010 | Pubmed ID: 20457829
The insertion of amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors into the plasma membrane and removal via internalization are essential for regulating synaptic strength, which underlies the basic mechanism of learning and memory. The retinocollicular pathway undergoes synaptic refinement during development and shows a wide variety of long-term synaptic changes; however, still little is known about its underlying molecular regulation. Here we report a rapid developmental long-term potentiation (LTP)/long-term depression (LTD) switch and its intracellular mechanism at the rat retinocollicular pathway from postnatal day 5 (P5) to P14. Before P9, neurons always exhibited LTP, whereas LTD was observed only after P10. Blockade of GluR2/3-glutamate receptor-interacting protein (GRIP)/AMPA-receptor-binding protein (ABP)/protein interacting with C kinase 1 (PICK1) interactions with pep2-SVKI could sustain the LTP after P10. This suggests that the LTP/LTD switch relied on PDZ protein activities. Selective interruption of GluR2/3-PICK1 binding by pep2-EVKI blocked the long-lasting effects of both LTP and LTD, suggesting a role for PICK1 in the maintenance of long-term synaptic plasticity. Interestingly, synaptic expression of GRIP increased more than twofold from P7 to P11, whereas ABP and PICK1 expression levels remained stable. Blockade of spontaneous retinal input suppressed this increase and abolished the LTP/LTD switch. These results suggest that the increased GRIP synaptic expression may be a key regulatory factor in mediating the activity-dependent developmental LTP/LTD switch, whereas PICK1 may be required for both LTP and LTD to maintain their long-term effects.
Application of PCR-LDR-nucleic Acid Detection Strip in Detection of YMDD Mutation in Hepatitis B Patients Treated with Lamivudine
Journal of Medical Virology. Jul, 2010 | Pubmed ID: 20513076
Chronic hepatitis B virus (CHBV) infection causes cirrhosis and hepatocellular carcinoma. Lamivudine (LAM) has been successfully used to treat CHBV infections but prolonged use leads to the emergence of drug-resistant variants. This is primarily linked to a mutation in the tyrosine-methionine-aspartate-aspartate (YMDD) motif of the HBV polymerase gene at position 204. Rapid diagnosis of drug-resistant HBV is necessary for a prompt treatment response. Common diagnostic methods such as sequencing and restriction fragment length polymorphism (RFLP) analysis lack sensitivity and require significant processing. The aim of this study was to demonstrate the usefulness of a novel diagnostic method that combines polymerase chain reaction (PCR), ligase detection reaction (LDR) and a nucleic acid detection strip (NADS) in detecting site-specific mutations related to HBV LAM resistance. We compared this method (PLNA) to direct sequencing and RFLP analysis in 50 clinical samples from HBV infected patients. There was 90% concordance between all three results. PLNA detected more samples containing mutant variants than both sequencing and RFLP analysis and was more sensitive in detecting mixed variant populations. Plasmid standards indicated that the sensitivity of PLNA is at or below 3,000 copies per ml and that it can detect a minor variant at 5% of the total viral population. This warrants its further development and suggests that the PLNA method could be a useful tool in detecting LAM resistance.
The Journal of Organic Chemistry. Aug, 2010 | Pubmed ID: 20590136
The asymmetric direct vinylogous aldol reaction of unactivated gamma-butenolide with aldehydes has been developed, giving the corresponding 5-(1'-hydroxy)butenolide derivatives in high yields (up to 93%) and enantioselectivities (up to 83% ee) under mild conditions.
Analytical Biochemistry. Nov, 2010 | Pubmed ID: 20655863
In metabolomic research, blood plasma and serum have been considered to possess similar compositions and properties. Their perceived equivalence has resulted in researchers choosing arbitrarily between serum and plasma for analysis. Here, routine serum and plasma were prepared and their low-molecular-weight compounds were determined using gas chromatography/time-of-flight mass spectrometry. Principal components analysis was applied to process the acquired data, and marked differences in metabolite profiles were observed between serum and plasma. Of the 72 identified compounds, 36 (50%) discriminate serum from plasma, with 29 and 7 metabolites showing a significantly higher abundance (t test, P<0.05) in serum and plasma, respectively. Incubation of blood had distinct effects on the analyte peak areas, with the effects being more pronounced for plasma than for serum and more pronounced for a shorter incubation than for a longer incubation. These results highlight the importance in choosing serum or plasma as the analytical sample and in stipulating the incubation time. Because incubation affected the analyte peak areas less in serum than in plasma, we recommend serum as the sample of choice in metabolomic studies.
Electrogenerated Chemiluminescence Determination of C-reactive Protein with Carboxyl CdSe/ZnS Core/shell Quantum Dots
Physical Chemistry Chemical Physics : PCCP. Sep, 2010 | Pubmed ID: 20683528
Electrogenerated chemiluminescence (ECL) of water-soluble core/shell CdSe/ZnS quantum dots (QDs) coated with carboxylated polyethylene glycol polymers ("Qdot 625") was investigated in aqueous solutions using 2-(dibutylamino)ethanol (DBAE) and tri-n-propylamine (TPrA) as ECL coreactants. In both cases, ECL emissions at glassy carbon (GC) electrode appeared at the same potential of approximately 0.80 V vs. Ag/AgCl (3.0 M KCl), which was approximately 200 and approximately 150 mV more positive compared with the oxidation potentials for DBAE (approximately +0.60 V vs. Ag/AgCl) and TPrA (approximately +0.65 V vs. Ag/AgCl), respectively. The ECL intensity, however, was significantly affected by the type and the concentration of the ECL coreactant used as well as the nature of the working electrode. Under the present experimental conditions, ECL from DBAE was approximately 17 times stronger than that from TPrA. The maximum ECL was obtained at GC electrode when [DBAE] approximately = 53 mM, where a ratio of 11:3:1 in ECL intensity was evaluated for GC, Au, and Pt electrodes, respectively. The ECL emission of the Qdot 625/DBAE system had an apparent peak value of approximately 625 nm that matched well the fluorescence data. The QD as a label for ECL-based immunoassays of C-reactive protein (CRP) was realized by covalent binding of avidin on its surface, which allowed biotinylated anti-CRP to be attached and interacted with solution-phase CRP and the anti-CRP linked to micro-sized magnetic beads. The newly formed sandwich type aggregates were separated magnetically from the solution matrix, followed by the ECL generation at partially transparent Au nanoparticle-coated ITO electrode or Au/CD electrode in the presence of DBAE. Much stronger ECL responses were observed from the Au/CD electrode, at which a dynamic range of 1.0-10.0 microg mL(-1) CRP and a limit of detection of 1.0 microg mL(-1) CRP were obtained, respectively.
Phenotypes and Peripheral Mechanisms Underlying Inflammatory Pain-related Behaviors Induced by BmK I, a Modulator of Sodium Channels
Experimental Neurology. Nov, 2010 | Pubmed ID: 20736005
The integrated mechanisms of dynamic signaling of sodium channels involved in clinical pain are still not yet clear. In this study, a new rat inflammatory pain model was developed by using the unilateral intraplantar injection of BmK I, a receptor site 3-specific modulator of sodium channels from the venom of scorpion Buthus martensi Karsch (BmK). It was found that BmK I could induce several kinds of inflammatory pain-related behaviors including spontaneous pain companied with unique episodic paroxysms, primary thermal hypersensitivity, and mirror-image mechanical hypersensitivity with different time course of development, which could be suppressed by morphine, indomethacin, or bupivacaine to a different extent. The dramatic attenuation by pretreatment with resiniferatoxin (RTX), an ultrapotent analog of capsaicin, on BmK I-induced pain-related behaviors, paw edema, and spinal L4-L5 c-Fos expression demonstrated that capsaicin-sensitive primary afferent neurons played important roles in pain induced by BmK I. Furthermore, the electrophysiological recordings showed that BmK I persistently increased whole-cell and tetrodotoxin-resistant (TTX-R) peak sodium currents and significantly delayed the inactivation phase of whole-cell sodium currents but could not enhance capsaicin-evoked inward currents, in acute isolated small dorsal root ganglion neurons of rat. The results strongly suggested that the dynamic modulation of BmK I on sodium channels located in peripheral primary afferent neurons, especially in capsaicin-sensitive neurons, mediated pain sensation. Thus, BmK I may be a valuable pharmacological tool to understand the sodium channel-involved pain mechanisms.
Chronic Myeloid Leukemia Patients Sensitive and Resistant to Imatinib Treatment Show Different Metabolic Responses
PloS One. 2010 | Pubmed ID: 20949032
The BCR-ABL tyrosine kinase inhibitor imatinib is highly effective for chronic myeloid leukemia (CML). However, some patients gradually develop resistance to imatinib, resulting in therapeutic failure. Metabonomic and genomic profiling of patients' responses to drug interventions can provide novel information about the in vivo metabolism of low-molecular-weight compounds and extend our insight into the mechanism of drug resistance. Based on a multi-platform of high-throughput metabonomics, SNP array analysis, karyotype and mutation, the metabolic phenotypes and genomic polymorphisms of CML patients and their diverse responses to imatinib were characterized. The untreated CML patients (UCML) showed different metabolic patterns from those of healthy controls, and the discriminatory metabolites suggested the perturbed metabolism of the urea cycle, tricarboxylic acid cycle, lipid metabolism, and amino acid turnover in UCML. After imatinib treatment, patients sensitive to imatinib (SCML) and patients resistant to imatinib (RCML) had similar metabolic phenotypes to those of healthy controls and UCML, respectively. SCML showed a significant metabolic response to imatinib, with marked restoration of the perturbed metabolism. Most of the metabolites characterizing CML were adjusted to normal levels, including the intermediates of the urea cycle and tricarboxylic acid cycle (TCA). In contrast, neither cytogenetic nor metabonomic analysis indicated any positive response to imatinib in RCML. We report for the first time the associated genetic and metabonomic responses of CML patients to imatinib and show that the perturbed in vivo metabolism of UCML is independent of imatinib treatment in resistant patients. Thus, metabonomics can potentially characterize patients' sensitivity or resistance to drug intervention.
High Expression Levels of IKKalpha and IKKbeta Are Necessary for the Malignant Properties of Liver Cancer
International Journal of Cancer. Journal International Du Cancer. Mar, 2010 | Pubmed ID: 19728335
IKK-NF-kappaB signaling is regarded as an important factor in hepatocarcinogenesis and a potential target for liver cancer therapy. Therefore, in this study, we analyzed the expression of mRNAs encoding components and targets of NF-kappaB signaling including IKKalpha, IKKbeta, RANK, RANKL, OPG, CyclinD3, mammary serine protease inhibitor (Maspin), CyclinD1, c-FLIP, Bcl-xl, Stat3, Cip1 and Cip2 by real-time PCR in 40 patients with liver cancer. After statistical analysis, 7 indices including IKKalpha, IKKbeta, RANK, Maspin, c-FLIP, Cip2 and cyclinD1 were found to show significant differences between tumor tissue and its corresponding adjacent tissue. When IKKalpha and IKKbeta were downregulated in the hepatocellular carcinoma (HCC) cell lines of MHCC-97L and MHCC-97H in vitro, the numbers of BrdU positive cells were decreased in both IKKalpha and IKKbeta knockdown cells. Levels of apoptosis were also investigated in IKKalpha and IKKbeta knockdown cells. The growth of HCC was inhibited in the subcutaneous implantation model, and lung metastatogenesis was also significantly inhibited in the kidney capsule transplantation model. Downregulation of IKKalpha and IKKbeta in HCC cultured in vitro revealed that increased Maspin, OPG and RANKL expression was associated with metastasis of HCC. These findings were associated with downregulation of Bcl-XL and c-FLIP, which may be the reason for increased apoptosis. The therapeutic effect of IKKalpha and IKKbeta downregulation depends on extent of NF-kappaB inhibition and the malignant nature of the HCC. We anticipate that IKK-targeted gene therapy can be used in the treatment of HCC, a cancer that is notoriously resistant to radiation and chemotherapy.
Langmuir : the ACS Journal of Surfaces and Colloids. Mar, 2010 | Pubmed ID: 19810712
We report on a study of superhydrophobic surfaces submerged in water in a fluidic chamber. A surface-treated transmission grating was used as a superhydrophobic layer that had a well-defined diffraction pattern when a laser beam passed through the water-submerged grating sample, indicating a Cassie-Baxter state with trapped air between the water and grating interfaces. By applying pressure to the water in the fluidic chamber, the diffraction pattern can be changed because of the volume reduction of trapped air or water penetration into the grating. Depending on the maximum value of applied pressure in the fluidic chamber, the diffraction pattern change can be either reversible or irreversible after the release of the pressure. We attribute the irreversible change under high applied pressure to the switching from a Cassie-Baxter state to a Wenzel state.
Signal Transducer and Activator of Transcription 3 (STAT3) Regulates Adipocyte Differentiation Via Peroxisome-proliferator-activated Receptor Gamma (PPARgamma)
Biology of the Cell / Under the Auspices of the European Cell Biology Organization. Jan, 2010 | Pubmed ID: 19566485
STAT3 (signal transducer and activator of transcription 3) is an important transcription factor involved in many biological events, including apoptosis, tumorigenesis, angiogenesis and epithelial-to-mesenchymal transition. However, no direct evidence for a role of STAT3 in 3T3-L1 adipocyte differentiation has been reported.
Journal of Gastroenterology and Hepatology. Apr, 2011 | Pubmed ID: 21054517
Non-alcoholic steatohepatitis (NASH) is one entity in the spectrum of non-alcoholic fatty liver disease (NAFLD). The aim of this study was to explore the prevention and therapeutic effect of sophocarpine on experimental rat NASH.
The Role of Germline Promoters and I Exons in Cytokine-induced Gene-specific Class Switch Recombination
Journal of Immunology (Baltimore, Md. : 1950). Jan, 2011 | Pubmed ID: 21131417
Germline transcription precedes class switch recombination (CSR). The promoter regions and I exons of these germline transcripts include binding sites for activation- and cytokine-induced transcription factors, and the promoter regions/I exons are essential for CSR. Therefore, it is a strong hypothesis that the promoter/I exons regions are responsible for much of cytokine-regulated, gene-specific CSR. We tested this hypothesis by swapping the germline promoter and I exons for the murine γ1 and γ2a H chain genes in a transgene of the entire H chain C-region locus. We found that the promoter/I exon for γ1 germline transcripts can direct robust IL-4-induced recombination to the γ2a gene. In contrast, the promoter/I exon for the γ2a germline transcripts works poorly in the context of the γ1 H chain gene, resulting in expression of γ1 H chains that is <1% the wild-type level. Nevertheless, the small amount of recombination to the chimeric γ1 gene is induced by IFN-γ. These results suggest that cytokine regulation of CSR, but not the magnitude of CSR, is regulated by the promoter/I exons.
Speciation Characterization and Coagulation of Poly-silica-ferric-chloride: the Role of Hydrolyzed Fe(III) and Silica Interaction
Journal of Environmental Sciences (China). 2011 | Pubmed ID: 21790046
The highly efficient inorganic polymer flocculants (IPFs) of the ferric-silica system is a new and promising coagulant. Interactions between ferric species and silica play a large part in the coagulation of suspensions. These effects are quite distinct from those associated with polymeric or colloid silica. However, although these species are key to coagulation efficiency, they have not been comprehensively discussed. A new type of coagulant, poly-silica-ferric-chloride (PFSC), was synthesized by co-polymerization and characterized by time complexation spectroscopy and photon correlation spectroscopy. Compared with traditional ferric salt, the results indicated that PFSC had a higher molecular weight, lesser positive charge, lower Fe(b) and higher Fe(c). The higher the Si/Fe ratio, the higher the silica and lower the silica(c) found. The PFSC with appropriate polysilica acid not only obtained better coagulation/flocculation efficiency in turbidity removal, enhanced the flocculation index (FI) and provided less residual ferric, it also lowered water treatment costs compared to traditional ferric salt. Results showed that PFSC could remove colloid particles in water by charge neutralization and sweeping, adsorption bridging mechanism.
Enhancing the Solid-state Anaerobic Digestion of Fallen Leaves Through Simultaneous Alkaline Treatment
Bioresource Technology. Oct, 2011 | Pubmed ID: 21803572
Previous studies have shown that alkali pretreatment prior to anaerobic digestion (AD) can increase the digestibility of lignocellulosic biomass and methane yield. In order to simplify the process and reduce the capital cost, simultaneous alkali treatment and anaerobic digestion was evaluated for methane production from fallen leaves. The highest methane yield of 82 L/kg volatile solids (VS) was obtained at NaOH loading of 3.5% and substrate-to-inoculum (S/I) ratio of 4.1. The greatest enhancement in methane yield was achieved at S/I ratio of 6.2 with NaOH loading of 3.5% which was 24-fold higher than that of the control (without NaOH addition). Reactors at S/I ratio of 8.2 resulted in failure of the AD process. In addition, increasing the total solid (TS) content from 20% to 26% reduced biogas yield by 35% at S/I ratio of 6.2 and NaOH loading of 3.5%. Cellulose and hemicellulose degradation and methane yields are highly related.
Comparative Data on Effects of Leading Pretreatments and Enzyme Loadings and Formulations on Sugar Yields from Different Switchgrass Sources
Bioresource Technology. Dec, 2011 | Pubmed ID: 21816612
Dilute sulfuric acid (DA), sulfur dioxide (SO(2)), liquid hot water (LHW), soaking in aqueous ammonia (SAA), ammonia fiber expansion (AFEX), and lime pretreatments were applied to Alamo, Dacotah, and Shawnee switchgrass. Application of the same analytical methods and material balance approaches facilitated meaningful comparisons of glucose and xylose yields from combined pretreatment and enzymatic hydrolysis. Use of a common supply of cellulase, beta-glucosidase, and xylanase also eased comparisons. All pretreatments enhanced sugar recovery from pretreatment and subsequent enzymatic hydrolysis substantially compared to untreated switchgrass. Adding beta-glucosidase was effective early in enzymatic hydrolysis while cellobiose levels were high but had limited effect on longer term yields at the enzyme loadings applied. Adding xylanase improved yields most for higher pH pretreatments where more xylan was left in the solids. Harvest time had more impact on performance than switchgrass variety, and microscopy showed changes in different features could impact performance by different pretreatments.
Nano Letters. Sep, 2011 | Pubmed ID: 21823599
Herein we demonstrate that intrinsically fluorescent zinc oxide (ZnO) nanowires (NWs) can be adopted for molecularly targeted imaging of cancer cells, after they are functionalized to render water solubility, biocompatibility, and low cellular toxicity. Optical imaging of integrin α(v)β(3) on U87MG human glioblastoma cells was achieved with RGD peptide-conjugated green fluorescent ZnO NWs, which opened up new avenues of research for investigating ZnO NW-based agents in tumor vasculature-targeted molecular imaging and drug delivery.
Sugar Yields from Dilute Sulfuric Acid and Sulfur Dioxide Pretreatments and Subsequent Enzymatic Hydrolysis of Switchgrass
Bioresource Technology. Oct, 2011 | Pubmed ID: 21835614
Dacotah switchgrass was pretreated with sulfuric acid concentrations of 0.5, 1.0, and 2.0 wt.% at 140, 160, and 180 °C and with 1 and 3 wt.% sulfur dioxide at 180 °C over a range of times. Sulfur dioxide loadings of 0%, 1%, 3%, 5%, and 10%wt.% of dry biomass were also tested at 180 °C for 10 min. Sugar yields were tracked for pretreatment and subsequent enzymatic hydrolysis to identify conditions for the highest total sugar yields. Pretreatment with 1 wt.% dilute sulfuric acid at 140 °C for 40 min followed by enzymatic hydrolysis with 48.6 mg enzyme/g initial glucan in raw biomass resulted in ∼86% of theoretical yield for glucose and xylose combined. For sulfur dioxide pretreatment, the highest total sugar yield of about 87% occurred at 5% SO₂ for 10 min and 180 °C. However, xylose yields were higher at shorter times and glucose yields at longer times.
Bioresource Technology. Oct, 2011 | Pubmed ID: 21852125
The spent wheat straw from horse stall bedding has lower cellulose and hemicellulose contents, but higher volatile fatty acid content than raw wheat straw. Biogas production from solid-state anaerobic digestion (SS-AD) of spent wheat straw and raw wheat straw was compared in this study. The SS-AD tests were conducted at 22% total solids (TS) content using inoculum from a liquid AD system at three feedstock-to-inoculum (F/I) ratios of 2.0, 4.0, and 6.0. Daily methane yields of spent wheat straw peaked 8 and 3 days earlier than those of raw wheat straw at F/I ratios of 2.0 and 4.0, respectively. The highest methane yield of 150.0 L/kg volatile solids (VS) was obtained from spent wheat straw at an F/I ratio of 4.0, which was 56.2% higher than that of raw wheat straw. The corresponding cellulose and hemicellulose degradation of spent wheat straw was 24.1% and 49.4% higher than those of raw wheat straw, respectively.
Process and Technoeconomic Analysis of Leading Pretreatment Technologies for Lignocellulosic Ethanol Production Using Switchgrass
Bioresource Technology. Dec, 2011 | Pubmed ID: 21865030
Six biomass pretreatment processes to convert switchgrass to fermentable sugars and ultimately to cellulosic ethanol are compared on a consistent basis in this technoeconomic analysis. The six pretreatment processes are ammonia fiber expansion (AFEX), dilute acid (DA), lime, liquid hot water (LHW), soaking in aqueous ammonia (SAA), and sulfur dioxide-impregnated steam explosion (SO(2)). Each pretreatment process is modeled in the framework of an existing biochemical design model so that systematic variations of process-related changes are consistently captured. The pretreatment area process design and simulation are based on the research data generated within the Biomass Refining Consortium for Applied Fundamentals and Innovation (CAFI) 3 project. Overall ethanol production, total capital investment, and minimum ethanol selling price (MESP) are reported along with selected sensitivity analysis. The results show limited differentiation between the projected economic performances of the pretreatment options, except for processes that exhibit significantly lower monomer sugar and resulting ethanol yields.
Enhancement of Antibody Class-switch Recombination by the Cumulative Activity of Four Separate Elements
Journal of Immunology (Baltimore, Md. : 1950). Nov, 2011 | Pubmed ID: 21949022
Class-switch recombination of Ab isotype is mediated by a recombinational DNA deletion event and must be robustly upregulated during Ag-driven differentiation of B cells. The enhancer region 3' of the Cα gene is important for the upregulation of switch recombination. Using a transgene of the entire H chain C region locus, we demonstrate in this study that it is the four 3' enhancer elements themselves (a total of 4.7 kb) that are responsible for the upregulation rather than the 24 kb of DNA in between them. Neither allelic exclusion nor transgenic μ expression is reduced by deletion of the four 3' enhancers. We also test deletions of two or three of the 3' enhancers and show that deletion of more 3' enhancers results in a progressive reduction in both switch recombination and germline transcription of all H chain genes. Nevertheless, we find evidence for special roles for some 3' enhancers; different H chain genes are affected by different 3' enhancer deletions. Thus, we find that the dramatic induction of class-switch recombination during Ag-driven differentiation is the result of an interaction among four separated regulatory elements.
The Arabidopsis ABCG13 Transporter is Required for Flower Cuticle Secretion and Patterning of the Petal Epidermis
The New Phytologist. Jan, 2011 | Pubmed ID: 21232060
• Previous studies showed that ABCG11 and ABCG12, two ATP-binding-cassette (ABC) transporters, are required for cuticular lipids extracellular secretion. Here, we characterized ABCG13, a third clade member, to widen our limited knowledge regarding assembly of the plant's cuticle. • We isolated an abcg13 knockout mutant and used RNAi and artificial microRNA approaches to study the effect of ABCG13 loss-of-function. These plants were subsequently used to conduct a detailed analysis of cuticular lipids composition and cytological observations. • ABCG13 loss-of-function resulted in cuticle-related phenotypes that were restricted to flowers, including inter-organ post-genital fusions. Apart from a significant reduction in flower cutin monomers, the macromorphology and micromorphology of abcg13 petal epidermis was strongly affected. We also found that ABCG13 is highly expressed in flowers, predominantly in petals and carpels. • The results suggest that ABCG13 is required for the transport of flower cuticular lipids. This work introduces a new component to the recently emerging genetic network that makes the archetypal exterior of Arabidopsis flowers. While the question regarding the substrate specificity of the ABCG12-clade members remains open, these findings will facilitate future investigations regarding the interaction between the half-size ABCG-type transporters that likely take part in cuticle assembly.
Statistics in Medicine. Jan, 2011 | Pubmed ID: 21241041
Multi-arm trials meta-analysis is a methodology used in combining evidence based on a synthesis of different types of comparisons from all possible similar studies and to draw inferences about the effectiveness of multiple compared-treatments. Studies with statistically significant results are potentially more likely to be submitted and selected than studies with non-significant results; this leads to false-positive results. In meta-analysis, combining only the identified selected studies uncritically may lead to an incorrect, usually over-optimistic conclusion. This problem is known asbiselection bias. In this paper, we first define a random-effect meta-analysis model for multi-arm trials by allowing for heterogeneity among studies. This general model is based on a normal approximation for empirical log-odds ratio. We then address the problem of publication bias by using a sensitivity analysis and by defining a selection model to the available data of a meta-analysis. This method allows for different amounts of selection bias and helps to investigate how sensitive the main interest parameter is when compared with the estimates of the standard model. Throughout the paper, we use binary data from Antiplatelet therapy in maintaining vascular patency of patients to illustrate the methods. Copyright © 2011 John Wiley & Sons, Ltd.
Asymmetric Crossed-Conjugate Addition of Nitroalkenes to Enones by a Chiral Bifunctional Diamine Organocatalyst
Chemistry (Weinheim an Der Bergstrasse, Germany). Jan, 2011 | Pubmed ID: 21243633
Nano Letters. Feb, 2011 | Pubmed ID: 21261290
Three-dimensional (3D) nanowire (NW) networks are promising architectures for effectively translating the extraordinary properties of one-dimensional objects into a 3D space. However, to uniformly grow NWs in a 3D confined space is a serious challenge due to the coupling between crystal growth and precursor concentration that is often dictated by the mass flow characteristic of vapor or liquid phase reactants within the high-aspect ratio submicrometer channels in current strategies. We report a pulsed chemical vapor deposition (CVD) process that successfully addressed this issue and grew TiO(2) nanorods uniformly covering the entire inner surface of highly confined nanochannels. We propose a mechanism for the anisotropic growth of anatase TiO(2) based on the surface-reaction-limited CVD process. This strategy would lead to the realization of NW-based 3D nanoarchitectures from various functional materials for the applications of sensors, solar cells, catalysts, energy storage systems, and so forth.
Rhizobium Sphaerophysae Sp. Nov., a Novel Species Isolated from Root Nodules of Sphaerophysa Salsula in China
Antonie Van Leeuwenhoek. May, 2011 | Pubmed ID: 21308410
Four gram-negative, aerobic, motile, non-spore, forming rods with a wide pH and temperature range for growth (pH 7.0-11.0, optimum pH 8.0; 20-45°C, optimum 28°C) strains were isolated from root nodules of Sphaerophysa salsula and characterized by means of a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the four strains formed a new lineage related to the genus Rhizobium and the sequence similarities between the isolate and the most related type strain Rhizobium giardinii was 96.5%. These strains also formed a distinctive group from the reference strains for defined Rhizobium species based on housekeeping gene sequences (atpD and recA), BOX-PCR fingerprinting, phenotypic features and symbiotic properties. The representative strain CCNWGS0238(T) has DNA-DNA relatedness of less than 33.4% with the most closely related species R. giardinii. It is therefore proposed as a new species, Rhizobium sphaerophysae sp. nov., with isolate CCNWGS0238(T) (=ACCC17498(T) = HAMBI3074(T)) as the type strain.
Organocatalytic Sequential Michael Reactions: Stereoselective Synthesis of Multifunctionalized Tetrahydroindan Derivatives
Organic Letters. Mar, 2011 | Pubmed ID: 21309523
Multifunctionalized tetrahydroindan derivatives with four stereocenters were constructed via two sequential Michael reactions between cyclic γ,δ-unsaturated-β-ketoester and nitroalkenes initiated with 0.5-2 mol % of cinchona alkaloid based bifunctional organocatalysts and then with 1 equiv of tetramethylguanidine for cyclization. The desired products could be obtained in high yields (up to 99% yield) with excellent enantioselectivities (95-99% ee) as well as diastereoselectivities (up to >99:1 dr) even on a gram scale.
Chemosphere. Mar, 2011 | Pubmed ID: 21315407
In China, the safety of drinking water becomes a significant issue due to serious aquatic environmental pollution. The genotoxic levels of raw and finished water from seven typical waterworks located in the five basins in China were then evaluated using umu test. Effect of conventional treatment processes (coagulation, filtration and disinfection) on the genotoxicity and the fate of dissolved organic matter (DOM) was discussed. The results showed that most of the selected finished water presented genotoxicity at or lower than 300 mL water sample exposure dose. The genotoxic effects of finished water were significantly higher than those of raw water. It also exhibited that there existed higher correlation between genotoxic effect and Br(-) than the other water quality parameters. The brominated trihalomethanes played a more important role in finished water genotoxicity than brominated haloacetic acids. The treatment processes could increase the genotoxic effects of finished water, especially for the chlorination treatment. The fluorescence spectra and high performance size-exclusion chromatogram analysis of DOM characters indicated that the proportion of low molecular weight acids, nitrogen containing aromatics, proteinaceous and microbially derived organic matters (200-300 Da) increased during purification processes, which indicated probably the release or formation of drinking water genotoxins.
Asymmetric Crossed-conjugate Addition of Nitroalkenes to Enones by a Chiral Bifunctional Diamine Organocatalyst
Chemistry (Weinheim an Der Bergstrasse, Germany). Feb, 2011 | Pubmed ID: 21319233
PloS One. 2011 | Pubmed ID: 21445248
BK channels are usually activated by membrane depolarization and cytoplasmic Ca(2+). Especially,the activity of BK channel (α+β4) can be modulated by martentoxin, a 37 residues peptide, with Ca(2+)-dependent manner. gBK channel (glioma BK channel) and BK channel (α+β1) possessed higher Ca(2+) sensitivity than other known BK channel subtypes.
Nanotechnology. Jun, 2011 | Pubmed ID: 21454935
An aqueous solution-based doping strategy was developed for controlled doping impurity atoms into a ZnO nanowire (NW) lattice. Through this approach, antimony-doped ZnO NWs were successfully synthesized in an aqueous solution containing zinc nitrate and hexamethylenetetramine with antimony acetate as the dopant source. By introducing glycolate ions into the solution, a soluble antimony precursor (antimony glycolate) was formed and a good NW morphology with a controlled antimony doping concentration was successfully achieved. A doping concentration study suggested an antimony glycolate absorption doping mechanism. By fabricating and characterizing NW-based field effect transistors (FETs), stable p-type conductivity was observed. A field effect mobility of 1.2 cm(2) V(-1) s(-1) and a carrier concentration of 6 × 10(17) cm(-3) were achieved. Electrostatic force microscopy (EFM) characterization on doped and undoped ZnO NWs further illustrated the shift of the metal-semiconductor barrier due to Sb doping. This work provided an effective large-scale synthesis strategy for doping ZnO NWs in aqueous solution.
Comparison of Microwaves to Fluidized Sand Baths for Heating Tubular Reactors for Hydrothermal and Dilute Acid Batch Pretreatment of Corn Stover
Bioresource Technology. May, 2011 | Pubmed ID: 21463933
Heating of batch tubular reactors with fluidized sand baths and with microwaves resulted in distinctive sugar yield profiles from pretreatment and subsequent enzymatic hydrolysis of corn stover at the same time, temperature, and dilute sulfuric acid concentration combinations and hydrothermal pretreatment conditions. Microwave heated pretreatment led to faster xylan, lignin, and acetyl removal as well as earlier xylan degradation than sand baths, but maximum sugar recoveries were similar. Solid state CP/MAS NMR revealed that microwave heating was more effective in altering cellulose structural features especially in breakdown of amorphous regions of corn stover than sand bath heating. Enzymatic hydrolysis of pretreated corn stover was improved by microwave heating compared to sand bath heating. Mechanisms were proposed to explain the differences in results for the two systems and provide new insights into pretreatment that can help advance this technology.
Bioresource Technology. Dec, 2011 | Pubmed ID: 21478012
This work studied the benefits of adding different enzyme cocktails (cellulase, xylanase, β-glucosidase) to pretreated switchgrass. Pretreatment methods included ammonia fiber expansion (AFEX), dilute-acid (DA), liquid hot water (LHW), lime, lime+ball-milling, soaking in aqueous ammonia (SAA), and sulfur dioxide (SO(2)). The compositions of the pretreated materials were analyzed and showed a strong correlation between initial xylan composition and the benefits of xylanase addition. Adding xylanase dramatically improved xylan yields for SAA (+8.4%) and AFEX (+6.3%), and showed negligible improvement (0-2%) for the pretreatments with low xylan content (dilute-acid, SO(2)). Xylanase addition also improved overall yields with lime+ball-milling and SO(2) achieving the highest overall yields from pretreated biomass (98.3% and 93.2%, respectively). Lime+ball-milling obtained an enzymatic yield of 92.3kg of sugar digested/kg of protein loaded.
Effects of Enzyme Loading and β-glucosidase Supplementation on Enzymatic Hydrolysis of Switchgrass Processed by Leading Pretreatment Technologies
Bioresource Technology. Dec, 2011 | Pubmed ID: 21507624
The objective of this work is to investigate the effects of cellulase loading and β-glucosidase supplementation on enzymatic hydrolysis of pretreated Dacotah switchgrass. To assess the difference among various pretreatment methods, the profiles of sugars and intermediates were determined for differently treated substrates. For all pretreatments, 72 h glucan/xylan digestibilities increased sharply with enzyme loading up to 25mg protein/g-glucan, after which the response varied depending on the pretreatment method. For a fixed level of enzyme loading, dilute sulfuric acid (DA), SO(2), and Lime pretreatments exhibited higher digestibility than the soaking in aqueous ammonia (SAA) and ammonia fiber expansion (AFEX). Supplementation of Novozyme-188 to Spezyme-CP improved the 72 h glucan digestibility only for the SAA treated samples. The effect of β-glucosidase supplementation was discernible only at the early phase of hydrolysis where accumulation of cellobiose and oligomers is significant. Addition of β-glucosidase increased the xylan digestibility of alkaline treated samples due to the β-xylosidase activity present in Novozyme-188.
Nanotechnology. Jun, 2011 | Pubmed ID: 21508463
Seedless hydrothermal synthesis has been improved by introducing an adequate content of ammonia into the nutrient solution, allowing the fabrication of dense and ultralong ZnO nanowire arrays over large areas on a substrate. The presence of ammonia in the nutrient solution facilitates the high density nucleation of ZnO on the substrate which is critical for the nanowire growth. In order to achieve an optimal growth, the growth conditions have been studied systematically as a function of ammonia content, growth temperature and incubation time. The effect of polyethyleneimine (PEI) has also been studied but shown to be of no benefit to the nucleation of ZnO. Ultradense and ultralong ZnO nanowires could be obtained under optimal growth conditions, showing no fused structure at the foot of the nanowire arrays. Due to different reaction kinetics, four growth regimes could be attributed, including the first fast growth, equilibrium phase, second fast growth and final erosion. Combining this simple method with optical lithography, ZnO nanowires could be grown selectively on patterned areas. In addition, the as-grown ZnO nanowires could be used for the fabrication of a piezoelectric nanogenerator. Compared to the device of ZnO nanowires made by other methods, a more than twice voltage output has been obtained, thereby proving an improved performance of our growth method.
Comparative Material Balances Around Pretreatment Technologies for the Conversion of Switchgrass to Soluble Sugars
Bioresource Technology. Dec, 2011 | Pubmed ID: 21524908
For this project, six chemical pretreatments were compared for the Consortium for Applied Fundamentals and Innovation (CAFI): ammonia fiber expansion (AFEX), dilute sulfuric acid (DA), lime, liquid hot water (LHW), soaking in aqueous ammonia (SAA), and sulfur dioxide (SO(2)). For each pretreatment, a material balance was analyzed around the pretreatment, optional post-washing step, and enzymatic hydrolysis of Dacotah switchgrass. All pretreatments+enzymatic hydrolysis solubilized over two-thirds of the available glucan and xylan. Lime, post-washed LHW, and SO(2) achieved >83% total glucose yields. Lime, post-washed AFEX, and DA achieved >83% total xylose yields. Alkaline pretreatments, except AFEX, solubilized the most lignin and a portion of the xylan as xylo-oligomers. As pretreatment pH decreased, total solubilized xylan and released monomeric xylose increased. Low temperature-long time or high temperature-short time pretreatments are necessary for high glucose release from late-harvest Dacotah switchgrass but high temperatures may cause xylose degradation.
GC-TOFMS Analysis of Metabolites in Adherent MDCK Cells and a Novel Strategy for Identifying Intracellular Metabolic Markers for Use As Cell Amount Indicators in Data Normalization
Analytical and Bioanalytical Chemistry. Jul, 2011 | Pubmed ID: 21533804
Cultured cell lines are useful models in biomedical research that characterize metabolic responses to various stimuli (e.g., pathogens, toxins, or drugs/chemicals) and explore the underlying mechanisms. However, data from cell metabolomic studies must be normalized to the amount of cells, which is dependent on diverse treatments. The currently used methods of cell counting and protein assay involve extra work and delay the quenching of intracellular metabolism. To develop a convenient, alternative approach, in this study, intracellular metabolites were extracted from a series amount of cultured adherent cells and profiled by gas chromatography-time-of-flight mass spectrometry (GC-TOFMS). The GC-TOFMS signal intensities for 11 intracellular markers present in two different cell lines showed good linearity with the protein content, with inositol and pantothenate most promising (correlation coefficient > 0.970). Despite the various amounts of cells, the data normalized to the metabolic markers and protein amounts showed similar effectiveness, resulted in better separation of the two cell lines, closer clustering within each group(cell line) on a principal components analysis scores plot, and had lower relative standard deviations for intracellular metabolites than those of the non-normalized data, suggesting that these markers were effective indicators of cell amounts and independent of cell lines.
Statistics in Medicine. May, 2011 | Pubmed ID: 21538449
Multi-arm trials meta-analysis is a methodology used in combining evidence based on a synthesis of different types of comparisons from all possible similar studies and to draw inferences about the effectiveness of multiple compared-treatments. Studies with statistically significant results are potentially more likely to be submitted and selected than studies with non-significant results; this leads to false-positive results. In meta-analysis, combining only the identified selected studies uncritically may lead to an incorrect, usually over-optimistic conclusion. This problem is known asbiselection bias. In this paper, we first define a random-effect meta-analysis model for multi-arm trials by allowing for heterogeneity among studies. This general model is based on a normal approximation for empirical log-odds ratio. We then address the problem of publication bias by using a sensitivity analysis and by defining a selection model to the available data of a meta-analysis. This method allows for different amounts of selection bias and helps to investigate how sensitive the main interest parameter is when compared with the estimates of the standard model. Throughout the paper, we use binary data from Antiplatelet therapy in maintaining vascular patency of patients to illustrate the methods.
Radiotherapy and Oncology : Journal of the European Society for Therapeutic Radiology and Oncology. May, 2011 | Pubmed ID: 21571383
Whether gemcitabine based chemoradiotherapy (GEM-based CRT) is superior to 5-fluorouracil based chemoradiotherapy (5-FU-based CRT) for locally advanced pancreatic cancer (LAPC) remains uncertain. The aim of the present study was to evaluate the effect of GEM-based CRT compared with 5-FU-based CRT.
Bioresource Technology. Dec, 2011 | Pubmed ID: 21571527
The US Department of Energy-funded Biomass Refining CAFI (Consortium for Applied Fundamentals and Innovation) project has developed leading pretreatment technologies for application to switchgrass and has evaluated their effectiveness in recovering sugars from the coupled operations of pretreatment and enzymatic hydrolysis. Key chemical and physical characteristics have been determined for pretreated switchgrass samples. Several analytical microscopy approaches utilizing instruments in the Biomass Surface Characterization Laboratory (BSCL) at the National Renewable Energy Laboratory (NREL) have been applied to untreated and CAFI-pretreated switchgrass samples. The results of this work have shown that each of the CAFI pretreatment approaches on switchgrass result in different structural impacts at the plant tissue, cellular, and cell wall levels. Some of these structural changes can be related to changes in chemical composition upon pretreatment. There are also apparently different structural mechanisms that are responsible for achieving the highest enzymatic hydrolysis sugar yields.
Application of Cellulase and Hemicellulase to Pure Xylan, Pure Cellulose, and Switchgrass Solids from Leading Pretreatments
Bioresource Technology. Dec, 2011 | Pubmed ID: 21596559
Accellerase 1000 cellulase, Spezyme CP cellulase, β-glucosidase, Multifect xylanase, and beta-xylosidase were evaluated for hydrolysis of pure cellulose, pure xylan, and switchgrass solids from leading pretreatments of dilute sulfuric acid, sulfur dioxide, liquid hot water, lime, soaking in aqueous ammonia, and ammonia fiber expansion. Distinctive sugar release patterns were observed from Avicel, phosphoric acid swollen cellulose (PASC), xylan, and pretreated switchgrass solids, with accumulation of significant amounts of xylooligomers during xylan hydrolysis. The strong inhibition of cellulose hydrolysis by xylooligomers could be partially attributed to the negative impact of xylooligomers on cellulase adsorption. The digestibility of pretreated switchgrass varied with pretreatment but could not be consistently correlated to xylan, lignin, or acetyl removal. Initial hydrolysis rates did correlate well with cellulase adsorption capacities for all pretreatments except lime, but more investigation is needed to relate this behavior to physical and compositional properties of pretreated switchgrass.
SHINE Transcription Factors Act Redundantly to Pattern the Archetypal Surface of Arabidopsis Flower Organs
PLoS Genetics. May, 2011 | Pubmed ID: 21637781
Floral organs display tremendous variation in their exterior that is essential for organogenesis and the interaction with the environment. This diversity in surface characteristics is largely dependent on the composition and structure of their coating cuticular layer. To date, mechanisms of flower organ initiation and identity have been studied extensively, while little is known regarding the regulation of flower organs surface formation, cuticle composition, and its developmental significance. Using a synthetic microRNA approach to simultaneously silence the three SHINE (SHN) clade members, we revealed that these transcription factors act redundantly to shape the surface and morphology of Arabidopsis flowers. It appears that SHNs regulate floral organs' epidermal cell elongation and decoration with nanoridges, particularly in petals. Reduced activity of SHN transcription factors results in floral organs' fusion and earlier abscission that is accompanied by a decrease in cutin load and modified cell wall properties. SHN transcription factors possess target genes within four cutin- and suberin-associated protein families including, CYP86A cytochrome P450s, fatty acyl-CoA reductases, GSDL-motif lipases, and BODYGUARD1-like proteins. The results suggest that alongside controlling cuticular lipids metabolism, SHNs act to modify the epidermis cell wall through altering pectin metabolism and structural proteins. We also provide evidence that surface formation in petals and other floral organs during their growth and elongation or in abscission and dehiscence through SHNs is partially mediated by gibberellin and the DELLA signaling cascade. This study therefore demonstrates the need for a defined composition and structure of the cuticle and cell wall in order to form the archetypal features of floral organs surfaces and control their cell-to-cell separation processes. Furthermore, it will promote future investigation into the relation between the regulation of organ surface patterning and the broader control of flower development and biological functions.
Lab on a Chip. Aug, 2011 | Pubmed ID: 21655556
Currently, most microfluidic devices are fabricated with embedded micro-channels and other elements in a close form with outward connections. Although much functionality has been demonstrated and a large number of applications have been developed, they are not easy for routine operation in biology laboratories where most in vitro cell processing still relies on the use of culture dishes, glass slides, multi-well plates, tubes, pipettes, etc. We report here an open access device which consists of an array of isolated micro-channels plated on a large culture surface, each of them having tiny nozzles for localized drug delivery. In a diffusion dominant regime, steady gradients of molecule concentration could be obtained and varied by changing the flow rate inside the micro-channels. As assay examples, cell staining and drug-induced cell apoptosis were demonstrated, showing fast cell responses in close proximity of the nozzles.
WITHDRAWN: Comparative Data on Effects of Leading Pretreatments and Enzyme Loadings and Formulations on Sugar Yields from Different Switchgrass Sources
Bioresource Technology. Apr, 2011 | Pubmed ID: 21664813
This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
The EMBO Journal. Jul, 2011 | Pubmed ID: 21673657
The bacterial flagellum is one of nature's most amazing and well-studied nanomachines. Its cell-wall-anchored motor uses chemical energy to rotate a microns-long filament and propel the bacterium towards nutrients and away from toxins. While much is known about flagellar motors from certain model organisms, their diversity across the bacterial kingdom is less well characterized, allowing the occasional misrepresentation of the motor as an invariant, ideal machine. Here, we present an electron cryotomographical survey of flagellar motor architectures throughout the Bacteria. While a conserved structural core was observed in all 11 bacteria imaged, surprisingly novel and divergent structures as well as different symmetries were observed surrounding the core. Correlating the motor structures with the presence and absence of particular motor genes in each organism suggested the locations of five proteins involved in the export apparatus including FliI, whose position below the C-ring was confirmed by imaging a deletion strain. The combination of conserved and specially-adapted structures seen here sheds light on how this complex protein nanomachine has evolved to meet the needs of different species.
Chemical Communications (Cambridge, England). Oct, 2011 | Pubmed ID: 21725530
Hierarchically structured zeolites (HSZs) have attracted increasing attention in the last few years, thanks to their unique hierarchical porous structures combining micro- and mesoporosity and superior material performances, especially in the bulky molecules-involved catalysis and adsorption applications. In this Feature Article, the recent advances in the HSZs synthetic methodologies and material performances in catalysis are overviewed. Further, some perspectives for the future development of HSZs are discussed.
Comparative Study on Enzymatic Digestibility of Switchgrass Varieties and Harvests Processed by Leading Pretreatment Technologies
Bioresource Technology. Dec, 2011 | Pubmed ID: 21741233
Feedstock quality of switchgrass for biofuel production depends on many factors such as morphological types, geographic origins, maturity, environmental and cultivation parameters, and storage. We report variability in compositions and enzymatic digestion efficiencies for three cultivars of switchgrass (Alamo, Dacotah and Shawnee), grown and harvested at different locations and seasons. Saccharification yields of switchgrass processed by different pretreatment technologies (AFEX, dilute sulfuric acid, liquid hot water, lime, and soaking in aqueous ammonia) are compared in regards to switchgrass genotypes and harvest seasons. Despite its higher cellulose content per dry mass, Dacotah switchgrass harvested after wintering consistently gave a lower saccharification yield than the other two varieties harvested in the fall. The recalcitrance of upland cultivars and over-wintered switchgrass may require more severe pretreatment conditions. We discuss the key features of different pretreatment technologies and differences in switchgrass cultivars and harvest seasons on hydrolysis performance for the applied pretreatment methods.
Journal of Materials Chemistry. May, 2011 | Pubmed ID: 21743779
In-depth understanding of the kinetics of the vapor deposition process is substantial for advancing this capable bottom-up nanostructure synthesis approach into a versatile large-scale nanomanufacturing technology. In this paper, we report a systematic study of the vapor deposition kinetics of ZnO nanomaterials under controlled atmosphere and properly refined deposition conditions. The experiments clearly evidenced the self-catalyzed growth of ZnO NWs via the formation of ZnO nanoflowers. This result illustrated how ZnO morphologies were associated with the discrepancy between oxidation rate and condensation rate of Zn. The capability of switching the NW morphologies and possibly mechanisms was demonstrated by kinetically controlling the deposition system. The high Zn composition during the deposition resulted in strongly luminescent NWs, which can be used for optical imaging applications. This research discovered a fundamental kinetics that governs the mechanisms and morphology selection of nanostructures in a non-catalyst growth system.
Three-dimensional High-density Hierarchical Nanowire Architecture for High-performance Photoelectrochemical Electrodes
Nano Letters. Aug, 2011 | Pubmed ID: 21770438
Three-dimensional (3D) nanowire (NW) networks are promising for designing high-performance photoelectrochemical (PEC) electrodes owing to their long optical path for efficient light absorption, high-quality one-dimensional conducting channels for rapid electron-hole separation and charge transportation, as well as high surface areas for fast interfacial charge transfer and electrochemical reactions. By growing titanium dioxide (TiO(2)) nanorods (NRs) uniformly on dense Si NW array backbones, we demonstrated a novel three-dimensional high-density heterogeneous NW architecture that could enhance photoelectrochemical efficiency. A 3D NW architecture consisting of 20 μm long wet-etched Si NWs and dense TiO(2) NRs yielded a photoelectrochemical efficiency of 2.1%, which is three times higher than that of TiO(2) film-Si NWs having a core-shell structure. This result suggests that the 3D NW architecture is superior to straight NW arrays for PEC electrode design. The efficiency could be further improved by optimizing the number of overcoating cycles and the length/density of NW backbones. By implementing these 3D NW networks into electrode design, one may be able to advantageously impact PEC and photovoltaic device performance.
The European Journal of Contraception & Reproductive Health Care : the Official Journal of the European Society of Contraception. Aug, 2011 | Pubmed ID: 21774564
To investigate the occurrence of unwanted pregnancies among renal transplant recipients and to identify major contributing factors.
Journal of Nanoscience and Nanotechnology. Apr, 2011 | Pubmed ID: 21776731
Faceted zinc oxide nanonecklace (ZnO NN) arrays were grown on r-plane sapphires along one direction (ZnO  II sapphire [10-11] and ZnO (-12-10) II sapphire (01-12)) using chemical vapor deposition. After coated with 45 nm gold films and annealed at 250 degrees C for 30 seconds, the coated ZnO NNs exhibit satisfactory and stable surface enhanced Raman scattering (SERS) effects when tested with melamine and other chemicals. The limit of detection of melamine is 10(-5) mol/L and the analytical enhancement factor is 10(4), which is competitive to a commercial substrate. This study indicates that gold coated ZnO NN substrates have a great potential as SERS-active substrates in rapid detection of trace amount food contaminants such as melamine and other chemicals.
Zhejiang Da Xue Xue Bao. Yi Xue Ban = Journal of Zhejiang University. Medical Sciences. Sep, 2011 | Pubmed ID: 21984160
To investigate the aortic elastic properties and its clinical significance in intracranial aneurysms (IAs).
Gastrointestinal Endoscopy. Nov, 2011 | Pubmed ID: 22032315
EUS elastography is a new technique for differentiating benign and malignant lymph nodes (LNs) by describing the mechanical property of the target tissue.
Microfluidic Devices with Disposable Enzyme Electrode for Electrochemical Monitoring of Glucose Concentrations
Electrophoresis. Nov, 2011 | Pubmed ID: 22038673
This article describes the fabrication of tube-like microchannels made of UV curable polymer on a glass substrate and the device assembling with a disposable enzyme-working electrode for high-sensitivity electrochemical detection. While both reference and counter electrodes are patterned on the surface of the glass substrate, the working electrode is flipped on the top of the channel with an open access, providing a face-to-face probing configuration. When the enzyme electrode is contaminated or degraded, it can be easily replaced by a new one, keeping the main body of the device and the detection schema unchanged. Using glucose oxidase-coated gold electrodes, we were able to determine a linear amperometry response to the glucose concentrations in the range of 2-16 mM. By replacing the as-prepared working electrode by the one after thermal treatments, we showed a much more degraded enzyme electrode activity, enabling efficient determination of the electrode quality as well as the whole process optimization.
Hypothalamic Gene Expression in ω-3 PUFA-deficient Male Rats Before, and Following, Development of Hypertension
Hypertension Research : Official Journal of the Japanese Society of Hypertension. Nov, 2011 | Pubmed ID: 22072108
Dietary deficiency of ω-3 fatty acids (ω-3 DEF) produces hypertension in later life. This study examined the effect of ω-3 DEF on blood pressure and hypothalamic gene expression in young rats, before the development of hypertension, and in older rats following the onset of hypertension. Animals were fed experimental diets that were deficient in ω-3 fatty acids, sufficient in short-chain ω-3 fatty acids or sufficient in short- and long-chain ω-3 fatty acids, from the prenatal period until 10 or 36 weeks-of-age. There was no difference in blood pressure between groups at 10 weeks-of-age; however, at 36 weeks-of-age ω-3 DEF animals were hypertensive in relation to sufficient groups. At 10 weeks, expression of angiotensin-II(1A) receptors and dopamine D(3) receptors were significantly increased in the hypothalamic tissue of ω-3 DEF animals. In contrast, at 36 weeks, α(2a) and β(1) adrenergic receptor expression was significantly reduced in the ω-3 DEF group. Brain docosahexaenoic acid was significantly lower in ω-3 DEF group compared with sufficient groups. This study demonstrates that dietary ω-3 DEF causes changes both in the expression of key genes involved in central blood pressure regulation and in blood pressure. The data may indicate that hypertension resulting from ω-3 DEF is mediated by the central adrenergic system.Hypertension Research advance online publication, 10 November 2011; doi:10.1038/hr.2011.194.
Nano Letters. Dec, 2011 | Pubmed ID: 22088237
Through a process of photoelectrochemical (PEC) water splitting, we demonstrated an effective strategy for engineering the barrier height of a heterogeneous semiconductor interface by piezoelectric polarization, known as the piezotronic effect. A consistent enhancement or reduction of photocurrent was observed when tensile or compressive strains were applied to the ZnO anode, respectively. The photocurrent variation is attributed to a changed barrier height at the ZnO/ITO interface, which is a result of the remnant piezoelectric potential across the interface due to a nonideal free charge distribution in the ITO electrode. In our system, ∼1.5 mV barrier height change per 0.1% applied strain was identified, and 0.21% tensile strain yielded a ∼10% improvement of the maximum PEC efficiency. The remnant piezopotential is dictated by the screening length of the materials in contact with piezoelectric component. The difference between this time-independent remnant piezopotential effect and time-dependent piezoelectric effect is also studied in details.
[Generation of Mouse Parthenogenetic Embryonic Stem Cells and Preliminary Study of the Differentiation Ability to Motor Neurons]
Yi Chuan = Hereditas / Zhongguo Yi Chuan Xue Hui Bian Ji. Nov, 2011 | Pubmed ID: 22120079
In this study, we generated embryonic stem cells from parthenogenetic embryos (PESCs), and induced them to differentiate to motor neurons, which could be an alternative source of histocompatible cells for replacement of therapy and theoretical foundation for studying the relationship of genome imprint and neural differentiation. The parthenogenetic activation rate of B6D2F1 mouse oocytes was 93.26%. We established eight parthenogenetic embryonic stem cell lines and the establishment rate from parthenogenetic embryos was 23.53%. The pluripotency marker Oct4, the cell surface marker SSEA-1, and alkaline phosphatase exhibited in PESCs. Karyotype analysis showed normal 40 chromosomes when examined at passages 10 and 30, which was in accordance with their oocyte origins. Three germinal layers were differentiated in vivo and in vitro. Mouse PESCs, which were treated by tretinoin and sonic hedgehog with extracellular matrix, could generate motor neurons that expressed the specific markers such as HB9 and Olig2.
[Clinical Re-evaluation of Effects of Different Treatments to Prevent from Phlebitis Induced by Chansu Injection]
Zhongguo Zhong Yao Za Zhi = Zhongguo Zhongyao Zazhi = China Journal of Chinese Materia Medica. Oct, 2011 | Pubmed ID: 22292370
To re-evaluate the effects of different treatments to prevent from phlebitis induced by Chansu injection.
Zhonghua Bing Li Xue Za Zhi Chinese Journal of Pathology. Oct, 2011 | Pubmed ID: 22321548
To study the clinicopathologic features and histogenesis of calcifying fibrous tumor (CFT).
[Protective Functions of Recombinant Protein Targeted at RANKL Against Hepatic Ischemia/reperfusion Injury Transfected by Retrovirus in Mice]
Zhonghua Yi Xue Za Zhi. Oct, 2011 | Pubmed ID: 22321985
To explore the protective functions of recombinant protein RANK-Fc against hepatic ischemia/reperfusion injury and clarify its possible mechanism.
Microglial Activation Induced by Brain Trauma is Suppressed by Post-injury Treatment with a PARP Inhibitor
Journal of Neuroinflammation. Feb, 2012 | Pubmed ID: 22335939
ABSTRACT: BACKGROUND: Traumatic brain injury (TBI) induces activation of microglia. Activated microglia can in turn increase secondary injury and impair recovery. This innate immune response requires hours to days to become fully manifest, thus providing a clinically relevant window of opportunity for therapeutic intervention. Microglial activation is regulated in part by poly(ADP-ribose) polymerase-1 (PARP-1). Inhibition of PARP-1 activity suppresses NF-kB-dependent gene transcription and thereby blocks several aspects of microglial activation. Here we evaluated the efficacy of a PARP inhibitor, INO-1001, in suppressing microglial activation after cortical impact in the rat. METHODS: Rats were subjected to controlled cortical impact and subsequently treated with 10 mg/kg of INO-1001 (or vehicle alone) beginning 20-24 hours after the TBI. Brains were harvested at several time points for histological evaluation of inflammation and neuronal survival, using markers for microglial activation (morphology and CD11b expression), astrocyte activation (GFAP), and neuronal survival (NeuN). Rats were also evaluated at 8 weeks after TBI using measures of forelimb dexterity: the sticky tape test, cylinder test, and vermicelli test. RESULTS: Peak microglial and astrocyte activation was observed 5 to 7 days after this injury. INO-1001 significantly reduced microglial activation in the peri-lesion cortex and ipsilateral hippocampus. No rebound inflammation was observed in rats that were treated with INO-1001 or vehicle for 12 days followed by 4 days without drug. The reduced inflammation was associated with increased neuronal survival in the peri-lesion cortex and improved performance on tests of forelimb dexterity conducted 8 weeks after TBI. CONCLUSIONS: Treatment with a PARP inhibitor for 12 days after TBI, with the first dose given as long as 20 hours after injury, can reduce inflammation and improve histological and functional outcomes.
Bioresource Technology. Jan, 2012 | Pubmed ID: 22306079
Storage of lignocellulosic biomass is critical for a year-round supply of feedstock for a biorefinery. Compared with dry storage, wet storage is a promising alternative technology, providing several advantages including reduced dry matter loss and fire risk and improved feedstock digestibility after storage. This study investigated the concurrent pretreatment and wet-storage of corn stover with the assistance of NaOH or a lignin-degrading fungus, Ceriporiopsis subvermispora, during a 90-d period. Compared with ensilage, adding NaOH or inoculation with C. subvermispora significantly enhanced the enzymatic degradability of corn stover by 2-3-fold after 90-d wet storage. Lignin and xylan removal during NaOH pretreatment and wet-storage were influenced by NaOH loading and moisture. NaOH pretreatment retarded the production of organic acids during storage and the acetate release correlated with lignin and xylan removal. Further study is needed to reduce cellulose degradation during the late stage of fungal treatment.
Small (Weinheim an Der Bergstrasse, Germany). Feb, 2012 | Pubmed ID: 22144073
Evaluation of systemic biosafety of nanomaterials urgently demands a comprehensive understanding of the mechanisms of the undesirable interference and systemic signaling that arises between man-made nanomaterials and biological systems. It is shown that exosomes may act as signal conveyors for nanoparticle-induced systemic immune responses. Exosomes are extracellularly secreted membrane vesicles which act as Trojan horses for the dissemination and intercellular communication of natural nanosized particles (like viruses). Upon exposure to magnetic iron oxide nanoparticles (MIONs), it is possible to dose-dependently generate a significant number of exosomes in the alveolar region of BALB/c mice. These exosomes are quickly eliminated from alveoli into systemic circulation and largely transfer their signals to the immune system. Maturation of dendritic cells and activation of splenic T cells are significantly induced by these exosomes. Furthermore, exosome-induced T-cell activation is more efficient toward sensitized T cells and in ovalbumin (OVA)-sensitized mice than in the unsensitized counterparts. Activation of systemic T cells reveals a T helper 1 polarization and aggravated inflammation, which poses potential hazards to the deterioration of allergic diseases in OVA-sensitized mice. The studies suggest that exosomes may act as conveyors for extrapulmonary signal transduction in nanoparticle-induced immune systemic responses, which are the key in vivo processes of manufactured nanoparticles executing either biomedical functions or toxic responses.
Production of Renewable Aromatic Compounds by Catalytic Fast Pyrolysis of Lignocellulosic Biomass with Bifunctional Ga/ZSM-5 Catalysts
Angewandte Chemie (International Ed. in English). Feb, 2012 | Pubmed ID: 22213226
Burn, baby, burn! A new bifunctional catalyst (Ga/ZSM-5) displays increased selectivity for the production of aromatic compounds during the catalytic fast pyrolysis of biomass. With this Ga-promoted ZSM-5 catalyst, olefins such as ethylene and propylene, which are produced as intermediates, are more efficiently converted into aromatic compounds, especially benzene. Ga/ZSM-5 also promotes decarbonylation and olefin-aromatization reactions.
Journal of Digestive Diseases. Feb, 2012 | Pubmed ID: 22257481
Self-expanding Metallic Stent As a Bridge to Surgery Versus Emergency Surgery for Obstructive Colorectal Cancer: a Meta-analysis
Surgical Endoscopy. Jan, 2012 | Pubmed ID: 21789642
The use of a colonic stent as a bridge to surgery aims to provide patients with elective one-stage surgical resection while reducing stoma creation and postoperative complications. This study used meta-analytic techniques to compare the outcomes of stent use as a bridge to surgery and emergency surgery in the management of obstructive colorectal cancer.
TRPC1 Proteins Confer PKC and Phosphoinositol Activation on Native Heteromeric TRPC1/C5 Channels in Vascular Smooth Muscle: Comparative Study of Wild-type and TRPC1-/- Mice
FASEB Journal : Official Publication of the Federation of American Societies for Experimental Biology. Jan, 2012 | Pubmed ID: 21968068
Ca(2+)-permeable cation channels consisting of canonical transient receptor potential 1 (TRPC1) proteins mediate Ca(2+) influx pathways in vascular smooth muscle cells (VSMCs), which regulate physiological and pathological functions. We investigated properties conferred by TRPC1 proteins to native single TRPC channels in acutely isolated mesenteric artery VSMCs from wild-type (WT) and TRPC1-deficient (TRPC1(-/-)) mice using patch-clamp techniques. In WT VSMCs, the intracellular Ca(2+) store-depleting agents cyclopiazonic acid (CPA) and 1,2-bis-(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA-AM) both evoked channel currents, which had unitary conductances of ∼2 pS. In TRPC1(-/-) VSMCs, CPA-induced channel currents had 3 subconductance states of 14, 32, and 53 pS. Passive depletion of intracellular Ca(2+) stores activated whole-cell cation currents in WT but not TRPC1(-/-) VSMCs. Differential blocking actions of anti-TRPC antibodies and coimmunoprecipitation studies revealed that CPA induced heteromeric TRPC1/C5 channels in WT VSMCs and TRPC5 channels in TRPC1(-/-) VSMCs. CPA-evoked TRPC1/C5 channel activity was prevented by the protein kinase C (PKC) inhibitor chelerythrine. In addition, the PKC activator phorbol 12,13-dibutyrate (PDBu), a PKC catalytic subunit, and phosphatidylinositol-4,5-bisphosphate (PIP(2)) and phosphatidylinositol-3,4,5-trisphosphate (PIP(3)) activated TRPC1/C5 channel activity, which was prevented by chelerythrine. In contrast, CPA-evoked TRPC5 channel activity was potentiated by chelerythrine, and inhibited by PDBu, PIP(2), and PIP(3). TRPC5 channels in TRPC1(-/-) VSMCs were activated by increasing intracellular Ca(2+) concentrations ([Ca(2+)](i)), whereas increasing [Ca(2+)](i) had no effect in WT VSMCs. We conclude that agents that deplete intracellular Ca(2+) stores activate native heteromeric TRPC1/C5 channels in VSMCs, and that TRPC1 subunits are important in determining unitary conductance and conferring channel activation by PKC, PIP(2), and PIP(3).
Neurosurgery. Feb, 2012 | Pubmed ID: 21826032
BACKGROUND:: The presence of osmotic gradients in the development of cerebral edema and the effectiveness of osmotherapy are well recognized. A modification of ventriculostomy catheters described in this article provides a method of osmotherapy that is not currently available. The reductive ventricular osmotherapy (RVOT) catheter removes free water from ventricular cerebrospinal fluid (CSF) by incorporating hollow fibers that remove water vapor, thereby providing osmotherapy without increasing osmotic load. OBJECTIVE:: To increase osmolarity in the ventricular CSF through use of RVOT in vivo. METHODS:: Twelve Yorkshire swine with contusional injury were randomized to external ventricular drainage (EVD) or RVOT for 12 hours. MR imaging was obtained. Serum, CSF, and brain ultrafiltrate were analyzed. Histology was compared using Fluor-Jade B and hematoxylin and eosin (H & E) stains. RESULTS:: With RVOT, CSF osmolality increased from 292 ± 2.7 to 345 ± 8.0 mOsmol/kg (mean ± SE, P = 0.0006), and the apparent diffusion coefficient (ADC) in the injury region increased from 0.735 ± 0.047 to 1.135 ± .063 (P = 0.004) over 24 hours. With EVD controls, CSF osmolarity and ADC were not significantly changed. Histologically, all RVOT pigs showed no evidence of neuronal degeneration (Grade 1/4) compared to moderate degeneration (Grade 2.6 ± .4/4) seen in EVD treated animals (P = 0.02). The difference in intracranial pressure (ICP) by area under the curve approached significance at P = .065 by Mann Whitney test. CONCLUSION:: RVOT can increase CSF osmolarity in vivo after experimental traumatic brain injury (TBI). In anticipated clinical use, only a slight increase in CSF osmolarity may be required to reduce cerebral edema.