Intraneuronal Localization of Nogo-A in the Rat

The Journal of Comparative Neurology. Mar, 2003  |  Pubmed ID: 12577319

Nogo-A is known to be a myelin-associated protein with strong inhibitory effect on neurite outgrowth and has been considered one of the major factors that hinder fiber regeneration in the central nervous system. Recent studies have demonstrated widespread occurrence of nogo-A mRNA and Nogo-A protein in neurons. Our concurrent immunohistochemical study substantiated the widespread distribution of neuronal Nogo-A. The present study was thus focused on its intraneuronal distribution in the central nervous system, using Western blotting, immunohistochemical, and immunogold electron microscopic techniques. Western blotting of the nucleus, cytoplasm, and membrane subcellular fractions of the cerebellum and spinal cord tissues demonstrated that all three fractions contained Nogo-A. Nogo-A immunoreactivity could be identified under confocal microscope in the nucleus, perikayon, and proximal dendrite and along the cell membrane. Under the electron microscope, the perikaryonal Nogo-A immunogold particles were mainly distributed at polyribosomes and rough endoplasmic reticulum, suggesting its relationship with translation process. The immunogold particles could also be found beneath or on the plasma membrane. In the nucleus, the Nogo-A immunogold particles were found to be localized at the chromatins of the nucleus, indicating its possible involvement in gene transcription. The presence of Nogo-A in the nucleus was further supported by transfection of COS-7L cells with nogo-A. This study provides the first immunocytochemical evidence for intraneuronal distribution of Nogo-A. Apparently, the significance of Nogo-A in the central nervous system is far more complex than what has been envisioned.

Effects of Valsartan with or Without Benazepril on Blood Pressure, Angiotensin II, and Endoxin in Patients with Essential Hypertension

Acta Pharmacologica Sinica. Apr, 2003  |  Pubmed ID: 12676074

To evaluate the effects of valsartan (Val) with or without benazepril (Ben) on blood pressure and plasma levels of angiotensin (Ang II) and digoxin-immunoreactive factors (endoxin) in patients with essential hypertension.

[Expression and Biological Activity of Human Neurotrophin-3 in Olfactory Ensheathing Cells Mediated by Retroviral Vector]

Shi Yan Sheng Wu Xue Bao. Feb, 2003  |  Pubmed ID: 12751203

We successfully constructed a retrovirus expression vector pRev-TRE-NT3. The supernatant with highest retroviral titers was obtained by transfection of two retrovirus vector, pRev-TRE-NT3 and pRev-Tet-On, into an ecotropic Ecopack-293 cells. Primarily cultured rat olfactory ensheathing cells (OECs) were co-infected with retrovirus following pRev-TRE-NT-3 and pRev-Tet-On system of produced retrovirus. By adding different concentrations of Doxycline, genetically modified OECs were induced to secrete human NT-3. The secreted NT-3 in OEC culture supernatant was detected with western-blot, and its biological activity was confirmed by the growth bioassay of dorsal root ganglion (DRG) cells. The results are as follows: (1) 0.78 kb hNT-3 cDNA was harvested and successfully cloned into pRev-TRE vector by PCR and restriction enzyme digestion methods. The constructed plasmid was identified with electrophoresis, and the direction of hNT-3 cDNA inserting pRev-TRE vector was integrated correctly; (2) NT-3-modified OEC culture supernatant contained 28 kd NT-3 which can bind NT-3 antibody in western-blotting assay, and NT-3 expression was concentration-dependent on Doxycline. NT-3 was not detected in control groups; and (3) Numerous DRG cells migrated from DRG tissue mass in NT-3-modified OECs experimental groups, and these cells had long and thin processes with strong dioptre. These processes formed complicated networks. As for unmodified OEC control groups, a few DRG cells migrated from the tissue mass, and the processes of these cells were rather short. In blank groups, no cells migrated and grew. And their processes in control groups are significantly shorter than NT-3-modified OECs experimental groups. Our results indicate that Tet-On-regulated NT-3 expression in OECs was efficient, offering novel material of in vivo transplantation for the repair of CNS injury.

Differentiation-inducing and Protective Effects of Adult Rat Olfactory Ensheathing Cell Conditioned Medium on PC12 Cells

Neuroscience Letters. Jul, 2003  |  Pubmed ID: 12850535

Transplantation of olfactory ensheathing cells has been one of the promising strategies in enhancing central nerve fiber regeneration. Membrane surface molecules on olfactory ensheathing cells mediating cell-cell interactions as well as various factors released from them are thought to be important for nerve regeneration. The latter, however, has not been fully substantiated by experimental data, particularly regarding the olfactory ensheathing cells of the adult animals. In the present study, the effects of adult olfactory ensheathing cell conditioned medium on PC12 cells were examined. The results show that the factors secreted by the adult olfactory ensheathing cells can promote PC12 cell differentiation and protect it from Zn(2+) insult.

[A Simulation Study on Brain Hematoma Real Time Monitoring by Use of Electrical Impedance Tomography]

Sheng Wu Yi Xue Gong Cheng Xue Za Zhi = Journal of Biomedical Engineering = Shengwu Yixue Gongchengxue Zazhi. Jun, 2003  |  Pubmed ID: 12856589

It is significant to develop a new set of medical equipment in which electrical impedance tomography is applied to brain hematoma real time monitor. This paper describes some progress in reconstruction algorithm of EIT. The methods make it possible to improve the precision as well as computation speed dramatically. In addition, intensive simulation describes all the process for real time monitoring of brain hematoma by exploiting EIT.

[Noninvasive Monitoring of Hypertensive Intracerebral Hemorrhage and Perihematomal Tissue Edema]

Zhonghua Yi Xue Za Zhi. Mar, 2003  |  Pubmed ID: 12887759

To investigate the dynamic change regularity of intracerebral hemorrhage and perihematomal tissue edema.

[Physiotherapy with Drugs for Acute Lymphadenitis of Face and Neck]

Hunan Yi Ke Da Xue Xue Bao = Hunan Yike Daxue Xuebao = Bulletin of Hunan Medical University. Jun, 2003  |  Pubmed ID: 14653099

To observe the clinical efficacy of acute lymphadenitis of face and neck treated by physiotherapy with drugs.

[Study of Correlation Dimension on EEG]

Sheng Wu Yi Xue Gong Cheng Xue Za Zhi = Journal of Biomedical Engineering = Shengwu Yixue Gongchengxue Zazhi. Feb, 2004  |  Pubmed ID: 15022471

The study of non-linear EEG is of great significance in clinical practice and research work. This paper has gone into the feasibility of calculating the correlation dimension and has developed some subjects with the characters of correlation dimension and the difference under four conditions: (1) passive eyes closed(PEC); (2) mental arithmetic with eyes closed(MAEC); (3) passive eyes open(PEO); (4) mental reasoning with eyes open (MRED). The results show it is feasible and meaningful to calculate correlation dimension and the correlation dimension can reflect the regular patterns of mental activity.

[The Prevention and Treatment of Tuberculosis in China: the Present and the Future]

Zhonghua Jie He He Hu Xi Za Zhi = Zhonghua Jiehe He Huxi Zazhi = Chinese Journal of Tuberculosis and Respiratory Diseases. Jul, 2004  |  Pubmed ID: 15312551

[Recovery of CO from an Ammonia Plant Tail Gas with Pressure Swing Adsorption Process]

Huan Jing Ke Xue= Huanjing Kexue / [bian Ji, Zhongguo Ke Xue Yuan Huan Jing Ke Xue Wei Yuan Hui "Huan Jing Ke Xue" Bian Ji Wei Yuan Hui.]. Sep, 2004  |  Pubmed ID: 15623018

Ammonia plant tail gas is an important CO source for C1 chemistry if an efficient separation/purification technology is available. Presented is pressure swing adsorption using a home made catalyst PU1 for recovery of CO from ammonia plant tail gas. A performance comparison of PU1 with a commercial zeolite was also presented. The pilot plant experiments were carried out in an intermission one-bed PSA unit with ammonia plant tail gas and a feed flow rate of 0.2-0.8 m3/h. The purity and recovery of CO was studied under various operating conditions. The operating conditions for the process were optimized and an optimum cyclic sequence of operation steps was proposed. A good performance of PU1 in the process was experimentally demonstrated. Product gas with a CO purity over 98% could be produced at a CO recovery of 75% for a feed gas CO concentration of 30% and gas pressure of 0.3 MPa.

Nonlinear Analysis in Cognition Process

Conference Proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference. 2004  |  Pubmed ID: 17271740

Cognition process is directly related to the brain functionality and is a dynamically changing system. Nonlinear analysis of EEG signals has been used as a means for studying the dynamical changes in cortical networks. In the course of cognition process, the activity complexity of the neuronal units is continually shifting. This phenomenon can be viewed with the topographic map and nonlinear EEG measures. The surrogate data method was used to show that EEG signals during cognitive activity are nonlinear. Additionally, we employ the compressed spectral array method to show that the gammaband EEG is closely related to cognitive processes.

Correlation Dimensions of EEG Changes During Mental Tasks

Conference Proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference. 2004  |  Pubmed ID: 17271752

Nonlinear analysis of electroencephalogram (EEG) signals provides a means for studying the dynamical changes in cortical networks related to brain electrical activity. In this study, the correlation dimension (D2) and point correlation dimension (PD2) were used to investigate the quantitative complexity of EEG during cognitive processes. EEGs were recorded in 30 normal subjects under seven conditions: two resting states and five mental activities. Results show that D2 and PD2 are significantly correlated. Compared to D2, PD2 is more sensitive to EEG data and less computationally intensive.

Study on Correlative Dimension of HRV Signals and Its Clinical Applications

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: 17281244

In this paper an advanced algorithm based on G-P algorithm is introduced to calculate the Correlative Dimension (CD) of HRV signals. Moreover, Theiler's Correction is considered to avoid the autocorrelation effect of the time serials. It will reduce the possibility to get spurious dimension. The algorithm is applied to clinical HRV data which are collected from twelve young healthy subjects under two conditions: 1) normal state; 2) autonomic nervous system (ANS) being blocked by certain acute selective blocking drug: Atropine or Metoprolol. The result sufficiently shows that the values of CD decrease after blockade, whether Atropine or Metoprolol, is given to the subjects. The reason is that these two kinds of autonomic blocking drug lead to ANS dysfunction. Then the complexity of the heart system decreases. So we can draw a conclusion that the CD value of HRV signals can reflex the complexity of the heart system and the state of ANS.

Dynamic Analysis of Heart Rate Variability Based on Orthogonal Wavelet Transform

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: 17281511

The analysis of heart rate variability (HRV) has become a tool for noninvasively detecting the cardiovascular modulation of autonomic nervous system (ANS). Traditional analysis in frequency-domain mainly includes calculating the power and the peak frequency of each physiological frequency component. Whether employing the non-parametric or parametric method to estimate the power spectrum density (PSD), the approximate stationarity of HRV is presupposed. However, only in short-term analysis can data meet this condition. With the increase of the record time, the nonstationarity of HRV notably appears. A dynamic analysis method based on orthogonal wavelet transform was proposed in this paper, which not only can obtain the traditional indices in frequency-domain, but can compute their dynamic values varying with time, called short-time power and short-time LF/HF ratio. The latter can evaluate the activity of autonomic nervous system. Finally the method was applied to trace the balance of ANS in Atropin drug experiment.

[Experimental Study on Repairing Segmental Bone Defects with Three Bio-bone Derived Materials]

Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi = Zhongguo Xiufu Chongjian Waike Zazhi = Chinese Journal of Reparative and Reconstructive Surgery. Feb, 2005  |  Pubmed ID: 15759926

To evaluate the osteogenesis of three bio-bone derived materials in repairing segmental bone defects.

[Study on the Effect of Composite of Basic Fibroblast Growth Factor and Partially Deproteinized Bone on the Repair of Femoral Head Defects]

Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi = Zhongguo Xiufu Chongjian Waike Zazhi = Chinese Journal of Reparative and Reconstructive Surgery. Mar, 2005  |  Pubmed ID: 15828470

To evaluate the effect of composite (bFGF/PDPB) of basic fibroblast growth factor (bFGF) and partially deproteinized bone (PDPB) on the repair of femoral head defect.

Association Between Mannose-binding Lectin Gene Polymorphisms and Susceptibility to Severe Acute Respiratory Syndrome Coronavirus Infection

The Journal of Infectious Diseases. Oct, 2005  |  Pubmed ID: 16170752

Genetic determinants of susceptibility to severe acute respiratory syndrome coronavirus (SARS-CoV) infection remain unknown. We assessed whether mannose-binding lectin (MBL) gene polymorphisms were associated with susceptibility to SARS-CoV infection or disease severity in an ethnically homogeneous population born in northern China.

[Culture, Purification and Biological Characters of Olfactory Ensheathing Cells from Adult Transgenic Mice]

Shi Yan Sheng Wu Xue Bao. Aug, 2005  |  Pubmed ID: 16231701

Several studies have demonstrated the potential of olfactory ensheathing cells (OECs) for the repair of central and peripheral nerve injury. In this work, ensheathing cells that express the receptor gene coding for enhanced green fluorescent protein (eGFP) from adult mice were isolated and purified, and then, its biological characters were examined in vitro. The work was based on combinations of fluorescence confocal, phase contrast, cell proliferation assay and immunolabeling identification. The results showed that (1) two major morphologically and immunohistochemically distinct types of cells were present after 15 days in the primary cultures of adult transgenic mice olfactory nerves and glomerular layers of the olfactory bulb. One cell type was bipolar or multipolar OECs and strained positively for P75 low affinity neurotrophic receptor (P75N), S100, and glial fibrillary acidic protein(GFAP). The other type was fibroblasts with flat or endothelial-like shape, and reacted with antibody against Thy1.1. (2) A simple, inexpensive method for purifying ensheathing cells, in which various harvested cell types showed different rates of attachment to the uncoated culture ware, was developed. This technique neither binds any antibodies nor requires any costly equipment, and yields a large number of highly purified cells. (3) In sequential observations over 22 days in culture, the population of purified cells was maintained and continued to proliferate for longer. This experiment not only supported and advanced the ensheathing cell research but also offered ideal materials of in vivo transplantation for the repair of CNS injury.

3-D Model-based Vehicle Tracking

IEEE Transactions on Image Processing : a Publication of the IEEE Signal Processing Society. Oct, 2005  |  Pubmed ID: 16238061

This paper aims at tracking vehicles from monocular intensity image sequences and presents an efficient and robust approach to three-dimensional (3-D) model-based vehicle tracking. Under the weak perspective assumption and the ground-plane constraint, the movements of model projection in the two-dimensional image plane can be decomposed into two motions: translation and rotation. They are the results of the corresponding movements of 3-D translation on the ground plane (GP) and rotation around the normal of the GP, which can be determined separately. A new metric based on point-to-line segment distance is proposed to evaluate the similarity between an image region and an instantiation of a 3-D vehicle model under a given pose. Based on this, we provide an efficient pose refinement method to refine the vehicle's pose parameters. An improved EKF is also proposed to track and to predict vehicle motion with a precise kinematics model. Experimental results with both indoor and outdoor data show that the algorithm obtains desirable performance even under severe occlusion and clutter.

[Determination of Amino Acids in Isatis Indigotica Fort by Reversed-phase High Performance Liquid Chromatography with Pre-column Derivatization]

Se Pu = Chinese Journal of Chromatography / Zhongguo Hua Xue Hui. Jul, 2005  |  Pubmed ID: 16250454

A reversed-phase high performance liquid chromatographic method with pre-column derivatization for the determination of amino acids, which were known as the characteristic constituents of Isatis indigotica Fort was established. The amino acids in alkalescence were derivatized with 2, 4-dinitro-fluorobenzene (DNFB). A reproducible method for simultaneous qualitative analysis of glutamic acid (Glu), argirine (Arg) and proline (Pro) and quantitative analysis of Arg and Pro in Isatis indigotica Fort has been established. NaAc buffer (pH 6.4) acetonitrile (85:15, v/v) as mobile phase and a Sinochrom ODS-BP column were used. The detector was operated at 360 nm. The linear regressions of the standard curves were determined for Arg and for Pro. The method was carried out over the range of 0. 627 - 5.016 microg for Arg and 0. 874 - 7.000 microg for Pro. The recoveries were 98.5% and 98.4% with the relative standard deviations of 2.5% and 2.3% for Arg and Pro respectively. The results indicate that among the three amino acids in Isatis indigotica Fort, Arg content was the highest, Pro the second and Glu the lowest. The method has good accuracy and repeatability and it can be used for the quality control of Isatis indigotica Fort.

[Changes of Tight Junction and Cx43 Expression in Microvessel Endothelial Cells of Mouse Lung Induced by Bleomycin]

Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi = Zhonghua Laodong Weisheng Zhiyebing Zazhi = Chinese Journal of Industrial Hygiene and Occupational Diseases. Feb, 2006  |  Pubmed ID: 16600115

To investigate the changes of expression of connexin-43 (Cx43) and the tight junction of microvessel endothelial cells (EC) to approach the effects in bleomycin (BLM) induced pulmonary fibrosis (PF).

Study of the Antifungal Ability of Bacillus Subtilis Strain PY-1 in Vitro and Identification of Its Antifungal Substance (iturin A)

Acta Biochimica Et Biophysica Sinica. Apr, 2006  |  Pubmed ID: 16604262

A Bacillus strain, denoted as PY-1, was isolated from the vascular bundle of cotton. Biochemical, physiological and 16S rDNA sequence analysis proved that it should belong to Bacillus subtilis. The PY-1 strain showed strong ability against many common plant fungal pathogens in vitro. The antibiotics produced by this strain were stable in neutral and basic conditions, and not sensitive to high temperature. From the culture broth of PY-1 strain, five antifungal compounds were isolated by acidic precipitation, methanol extraction, gel filtration and reverse-phase HPLC. Advanced identification was performed by mass spectrometry and nuclear magnetic resonance spectroscopy. These five antifungal compounds were proved to be the isomers of iturin A: A2, A3, A4, A6 and A7. In fast atom bombardment mass spectrometry/mass spectrometry collision-induced dissociation spectra, fragmentation ions from two prior linear acylium ions were observed, and the prior ion, Tyr-Asn-Gln-Pro-Asn-Ser-betaAA-Asn-CO+, was first reported.

[Effects of Sense Vascular Endothelial Growth Factor CDNA Transfection on Mononuclear Chemotaxis Protein-1 Expression in Rat Pulmonary Microvessel Endothelial Cells]

Zhonghua Jie He He Hu Xi Za Zhi = Zhonghua Jiehe He Huxi Zazhi = Chinese Journal of Tuberculosis and Respiratory Diseases. Jan, 2006  |  Pubmed ID: 16638301

To study the transformation characteristics of tight junction of microvessel endothelial cells in bleomycin (BLM) induced pulmonary fibrosis (PF), and the effects of vascular endothelial growth factor (VEGF) on mononuclear chemotaxis protein-1 (MCP-1) mRNA expression in pulmonary microvessel endothelial cells (EC).

A Glutathione S-transferase Catalyzes the Dehalogenation of Inhibitory Metabolites of Polychlorinated Biphenyls

Journal of Bacteriology. Jun, 2006  |  Pubmed ID: 16740949

BphK is a glutathione S-transferase of unclear physiological function that occurs in some bacterial biphenyl catabolic (bph) pathways. We demonstrated that BphK of Burkholderia xenovorans strain LB400 catalyzes the dehalogenation of 3-chloro 2-hydroxy-6-oxo-6-phenyl-2,4-dienoates (HOPDAs), compounds that are produced by the cometabolism of polychlorinated biphenyls (PCBs) by the bph pathway and that inhibit the pathway's hydrolase. A one-column protocol was developed to purify heterologously produced BphK. The purified enzyme had the greatest specificity for 3-Cl HOPDA (kcat/Km, approximately 10(4) M(-1) s(-1)), which it dechlorinated approximately 3 orders of magnitude more efficiently than 4-chlorobenzoate, a previously proposed substrate of BphK. The enzyme also catalyzed the dechlorination of 5-Cl HOPDA and 3,9,11-triCl HOPDA. By contrast, BphK did not detectably transform HOPDA, 4-Cl HOPDA, or chlorinated 2,3-dihydroxybiphenyls. The BphK-catalyzed dehalogenation proceeded via a ternary-complex mechanism and consumed 2 equivalents of glutathione (GSH) (Km for GSH in the presence of 3-Cl HOPDA, approximately 0.1 mM). A reaction mechanism consistent with the enzyme's specificity is proposed. The ability of BphK to dehalogenate inhibitory PCB metabolites supports the hypothesis that this enzyme was recruited to facilitate PCB degradation by the bph pathway.

Estrogen Receptor Alpha Polymorphisms Associated with Susceptibility to Hepatocellular Carcinoma in Hepatitis B Virus Carriers

Gastroenterology. Jun, 2006  |  Pubmed ID: 16762623

Overexpression of estrogen receptors (ESRs) is implicated in the development of hepatocellular carcinoma (HCC) in both animal models and humans. We examined whether the ESR1 polymorphisms were related to HCC risk among chronic hepatitis B virus carriers.

A Simple Parallel Analytical Method of Prenatal Screening

Gynecologic and Obstetric Investigation. 2006  |  Pubmed ID: 16791006

Protein microarray has progressed rapidly in the past few years, but it is still hard to popularize it in many developing countries or small hospitals owing to the technical expertise required in practice. We developed a cheap and easy-to-use protein microarray based on dot immunogold filtration assay for parallel analysis of ToRCH-related antibodies including Toxoplasma gondii, rubella virus, cytomegalovirus and herpes simplex virus type 1 and 2 in sera of pregnant women. It does not require any expensive instruments and the assay results can be clearly recognized by the naked eye. We analyzed 186 random sera of outpatients at the gynecological department with our microarray and commercial ELISA kit, and the results showed there was no significant difference between the two detection methods. Validated by clinical application, the microarray is easy to use and has a unique advantage in cost and time. It is more suitable for mass prenatal screening or epidemiological screening than the ELISA format.

[Evidence for the Presence of Motilin Receptor and a Study on the Mechanism of Motilin Induced Ca2+ Signaling in Rat Myenteric Neurons]

Sichuan Da Xue Xue Bao. Yi Xue Ban = Journal of Sichuan University. Medical Science Edition. Sep, 2006  |  Pubmed ID: 17037727

To observe whether the motilin receptor (MTLR) can be expressed in primarily cultured myenteric neurons of rats and investigate the mechanism of motilin induced Ca2+ signaling in myenteric neurons of rats.

Fusion of Fungicidal Peptide Dhvar4 to Enterococcal Peptide Pheromone Increases Its Bactericidal Activity Against Enterococcus Faecalis

Chemical Biology & Drug Design. Oct, 2006  |  Pubmed ID: 17105486

Bacterial peptide pheromone has a high affinity to its membrane receptor. Fusion of these peptides to pore-forming antimicrobial peptide might enhance its bactericidal activity against pheromone-sensing bacteria. We constructed two chimeric peptides by fusing the pore-forming fungicidal peptide dhvar4 to the C-terminus of enterococcal peptide pheromones cCF10 and cOB1 individually. Comparison on the bactericidal activities against pheromone-sensing bacteria Enterococcus faecalis demonstrates that the chimeric peptides cCF10-dhvar4 and cOB1-dhvar4 are more potent than the parent peptide dhvar4. The LD(50)s of both chimeric peptides (1.0 microm) are 10 times lower than that of dhvar4 (10.8 microm). Free peptide pheromone could inhibit E. faecalis killing mediated by both chimeric peptides. As same as that of the parent peptide, both chimeric peptides kill bacteria by disrupting its cell membrane. These results indicate that fused enterococcal peptide pheromone increases the bactericidal activity of fungicidal peptide against E. faecalis by improving its ability to reach the cell membrane.

[Dynamic Analysis of Heart Rate Variability Based on Wavelet Transform]

Sheng Wu Yi Xue Gong Cheng Xue Za Zhi = Journal of Biomedical Engineering = Shengwu Yixue Gongchengxue Zazhi. Oct, 2006  |  Pubmed ID: 17121332

The analysis of heart rate variability (HRV) has become a tool for noninvasively detecting the cardiovascular modulation of autonomic nervous system. Traditional analysis in frequency domain mainly includes calculating the power and detecting the peak frequency of each physiological frequency band. Whether employing the classical method or AR model to estimate the spectrum, the approximate stationarity of HRV is presupposed. Only in short term analysis can data meet this condition, while in long term the nonstationarity of HRV notably appears. A dynamic analysis method based on wavelet transform was proposed in this paper, which not only can obtain the traditional indices in frequency domain, but can compute their dynamic values varying with time, called short-time power and short-time LF/HF ratio. The latter can dynamically evaluate the activity of autonomic nervous. Finally the method was applied to trace the balance of autonomic nervous in Atropin drag experiment.

Optimized and Efficient Preparation of Astrocyte Cultures from Rat Spinal Cord

Cytotechnology. Oct, 2006  |  Pubmed ID: 19002867

Astrocytes constitute a major class of glial cells in the CNS, and play crucial roles in physiological functioning, performance and maintenance of the CNS, as well as promotion of neuronal migration and maturation. Astrocytes have also been directly and indirectly implicated in the pathophysiology of various trauma occurrences, development of neurodegenerative diseases and nerve regeneration. To further understand mechanisms by which astrocytes elicit these effects, the first critical step in the study of astrocytes is the preparation of purified astrocytes cultures. Here we describe a simple and convenient procedure for producing rat primary astrocyte cultures of high purity, viability and proliferation. For astrocyte culture, we have optimized the isolation procedures and cultivation conditions including coating substrates, enzyme digestion, seeding density and composition of the culture medium. Using immunofluorescent antibodies against GFAP and OX-42 in combination of Hoechst 33342 fluorescent staining, we found that the purity of the astrocyte cultures was >99%. Astrocytes had high viability as measured by 3-(4, 5-dimethyl-2-yl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay. In addition, flow cytometric analysis was used to measure and observe variations in the cell cycle after 1-2 passages and proliferation of astrocytes was detected with a high percentage of cells stand in S+G(2)/M phase. Therefore, the method described here is ideal for experiments, which require highly pure astrocyte cultures.

Spatially Dispersive Finite-difference Time-domain Analysis of Sub-wavelength Imaging by the Wire Medium Slabs

Optics Express. Jun, 2006  |  Pubmed ID: 19516680

In this paper, a spatially dispersive finite-difference time-domain (FDTD) method to model wire media is developed and validated. Sub-wavelength imaging properties of the finite wire medium slabs are examined. It is demonstrated that the slab with its thickness equal to an integer number of half-wavelengths is capable of transporting images with sub-wavelength resolution from one interface of the slab to another. It is also shown that the operation of such transmission devices is not sensitive to their transverse dimensions, which can be made even comparable to the wavelength. In this case, the edge diffractions are negligible and do not disturb the image formation.

Effectiveness of First Eight Methadone Maintenance Treatment Clinics in China

AIDS (London, England). Dec, 2007  |  Pubmed ID: 18172377

To evaluate the effectiveness of the first phase of eight methadone maintenance treatment (MMT) clinics in China.

Epidemiology of Schistosomiasis in the People's Republic of China, 2004

Emerging Infectious Diseases. Oct, 2007  |  Pubmed ID: 18257989

Results from the third nationwide cluster sampling survey on the epidemiology of schistosomiasis in the People's Republic of China, conducted by the Ministry of Health in 2004, are presented. A stratified cluster random sampling technique was used, and 239 villages were selected in 7 provinces where Schistosoma japonicum remains endemic. A total of 250,987 residents 6-65 years of age were included in the survey. Estimated prevalence rates in the provinces of Hunan, Hubei, Jiangxi, Anhui, Yunnan, Sichuan, and Jiangsu were 4.2%, 3.8%, 3.1%, 2.2%, 1.7%, 0.9%, and 0.3%, respectively. The highest prevalence rates were in the lake and marshland region (3.8%) and the lowest rates were in the plain region with waterway networks (0.06%). Extrapolation to all residents in schistosome-endemic areas indicated 726,112 infections. This indicates a reduction of 16.1% compared with a nationwide survey conducted in 1995. However, human infection rates increased by 3.9% in settings where transmission is ongoing.

Ambient Temperature Synthesis of High Enantiopurity N-protected Peptidyl Ketones by Peptidyl Thiol Ester-boronic Acid Cross-coupling

Journal of the American Chemical Society. Feb, 2007  |  Pubmed ID: 17263394

alpha-Amino acid thiol esters derived from N-protected mono-, di-, and tripeptides couple with aryl, pi-electron-rich heteroaryl, or alkenyl boronic acids in the presence of stoichiometric Cu(I) thiophene-2-carboxylate and catalytic Pd(2)(dba)(3)/triethylphosphite to generate the corresponding N-protected peptidyl ketones in good-to-excellent yields and in high enantiopurity. Triethylphosphite plays a key role as a supporting ligand by mitigating an undesired palladium-catalyzed decarbonylation-beta-elimination of the alpha-amino thiol esters. The peptidyl ketone synthesis proceeds at room temperature under nonbasic conditions and demonstrates a high tolerance to functionality.

High Level Expression of His-tagged Colicin 5 in E. Coli and Characterization of Its Narrow-spectrum Bactericidal Activity and Pore-forming Action

Protein Expression and Purification. Aug, 2007  |  Pubmed ID: 17451967

Since antibiotics with a broad spectrum of activity would select for resistance among the normal flora, colicins having a narrow spectrum of activity can potentially be developed as novel antibiotics. Colicin-based bactericidal proteins with modified spectra of activity might also be developed by further gene fusion or gene modification. To achieve these goals, it is necessary to first build an efficient system to produce large amounts of colicin. In the presence of an immunity gene, we successfully constructed an expression vector pQE30-cfa-cfi producing high levels of His-tagged colicin 5 (60-80 mg/L). We found that the purified His-tagged colicin 5 possesses narrow-spectrum bactericidal activity against nonimmune Escherichia coli cells. It is highly toxic to sensitive E. coli cells at a low concentration of 0.01 microg/ml, while it is nontoxic to other tested gram-negative bacteria, gram-positive bacteria and yeast at a high concentration of 1000 microg/ml. His-tagged colicin 5 kills sensitive cells by permeabilizing their cell membranes. It is not hemolytic to rabbit erythrocytes and has no obvious cytotoxicity to other nucleated mammalian cells at a high concentration of 500 microg/ml. The His-tagged colicin 5 is similar to wild-type colicin 5 in spectrum and bactericidal activity against E. coli. It is a potential novel antibiotic particularly for treating human and animal infections caused by pathogenic E. coli. Besides producing high level of colicin 5, the highly efficient expression vector constructed here might also be a useful tool to develop colicin-based artificial bactericidal proteins.

MDM2 Promoter SNP309 is Associated with Risk of Occurrence and Advanced Lymph Node Metastasis of Nasopharyngeal Carcinoma in Chinese Population

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research. May, 2007  |  Pubmed ID: 17473193

Mouse double minute 2 (MDM2) is a key negative regulator of the p53 activity. Recently, a polymorphism in the MDM2 intronic promoter, SNP309, was shown to influence MDM2 expression and p53 activity. We examined whether the SNP309 was related to the risk of developing nasopharyngeal carcinoma (NPC) among Chinese populations.

Accurate Modeling of the Optical Properties of Left-handed Media Using a Finite-difference Time-domain Method

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics. Mar, 2007  |  Pubmed ID: 17500838

This paper contains an important message regarding the numerical modeling of left-handed media (LHM) using the finite-difference time-domain (FDTD) method which remains at the moment one of the main techniques used in studies of these exotic materials. It is shown that conventional implementation of the dispersive FDTD method leads to an inaccurate description of evanescent waves in the LHM. This defect can be corrected using spatial averaging at the interfaces. However, a number of results obtained using the conventional FDTD method have to be reconsidered. For instance, accurate simulation of subwavelength imaging by the finite-sized slabs of left-handed media does not reveal the cavity effect reported by Chen [Phys. Rev. Lett. 92, 107404 (2004)]. Hence the finite transverse dimension of LHM slabs does not have significant effects on the subwavelength image quality, contrary to previous assertions.

Identification of Three Novel Proteins (SGSM1, 2, 3) Which Modulate Small G Protein (RAP and RAB)-mediated Signaling Pathway

Genomics. Aug, 2007  |  Pubmed ID: 17509819

We report a novel protein family consisting of three members, each of which contains RUN and TBC motifs and appears to be associated with small G protein-mediated signal transduction pathway. We named these proteins as small G protein signaling modulators (SGSM1/2/3). Northern blot analysis revealed that human SGSM2/3 are expressed ubiquitously in various tissues, whereas SGSM1 is expressed mainly in brain, heart, and testis. Mouse possessed the same protein family genes, and the in situ hybridization and immunohistochemical staining of tissue sections revealed that mouse Sgsm1/2/3 are expressed in the neurons of central nervous system, indicating the strong association of Sgsm family with neuronal function. Furthermore, endogenous Sgsm1 protein was localized in the trans-Golgi network of mouse Neuro2a cells by immunofluorescence microscopy. Expression of various cDNA constructs followed by immunoprecipitation assay revealed that human SGSM1/2/3 proteins are coprecipitated with RAP and RAB subfamily members of the small G protein superfamily. Based on these results, we postulated that the SGSM family members function as modulators of the small G protein RAP and RAB-mediated neuronal signal transduction and vesicular transportation pathways.

Expression of EphA2 in Human Astrocytic Tumors: Correlation with Pathologic Grade, Proliferation and Apoptosis

Tumour Biology : the Journal of the International Society for Oncodevelopmental Biology and Medicine. 2007  |  Pubmed ID: 17519535

A high expression of EphA2 has been detected in many non-central nervous system tumors; however, the EphA2 expression in brain astrocytic tumors remains unclear. In this study, we investigated the expression of EphA2 mRNA and protein in 90 cases of human astrocytic tumors by reverse transcription polymerase chain reaction and immunohistochemistry, respectively. The proliferative index (PI) of tumor cells was evaluated by Ki-67 immunohistochemistry, and the apoptotic index (AI) was determined by TdT-mediated dUTP nick end labeling assay. The correlation between EphA2 expression, pathologic grade, proliferation and apoptosis of astrocytic tumors was further analyzed. The results showed that 47.8% of cases expressed EphA2 mRNA and 43.3% of cases expressed EphA2 protein. With increasing pathologic grade, the positive rate of EphA2 mRNA and protein, as well as the EphA2 immunoreactivity score (IRS), increased markedly. The PI in the EphA2-positive group was significantly higher than in the EphA2-negative group. In addition, the PI was positively correlated with EphA2 IRS. Although there was no significant difference between the AI in the EphA2-positive group and that in the EphA2-negative group, the AI was inversely correlated with EphA2 IRS. Therefore, EphA2 may be a new biomarker for astrocytic tumors. It may also affect the proliferation and apoptosis of tumor cells and be an attractive therapy target for astrocytic tumors.

Lack of Support for an Association Between CLEC4M Homozygosity and Protection Against SARS Coronavirus Infection

Nature Genetics. Jun, 2007  |  Pubmed ID: 17534355

Functional Polymorphisms and Haplotypes in the Promoter of the MMP2 Gene Are Associated with Risk of Nasopharyngeal Carcinoma

Human Mutation. Nov, 2007  |  Pubmed ID: 17607721

Matrix metalloproteinases (MMPs) play important roles in cancer initiation and development. Several polymorphisms in the promoters of a number of MMP genes, which can affect the respective MMP production in an allele-specific manner, have been well characterized. We examined whether these functional polymorphisms were related to the risk of nasopharyngeal carcinoma (NPC) in Chinese populations. Eight polymorphisms in the promoter of MMP1, MMP2, MMP3, MMP7, MMP9, MMP12, and MMP13 were genotyped in two independent case-control populations; one is from Guangxi province (593 patients with NPC and 480 controls), and the other is from Guangdong province (239 patients and 286 controls). We observed significantly increased susceptibility to NPC for the MMP2 -1306CC (rs243865:C>T) (odds ratio [OR] = 2.01, 95% confidence interval [CI] = 1.30-3.10) and -735CC (rs2285053:C>T) (OR = 1.56, 95% CI = 1.17-2.09) genotype carriers compared with noncarriers in the Guangxi population. This association was confirmed in the Guangdong population (for -1306CC: OR = 2.19, 95% CI = 1.21-3.96; for -735CC: OR = 1.60, 95% CI = 1.13-2.28). The C(-1306)-C(-735) haplotype was also significantly associated with increased susceptibility to NPC in both the Guangxi (OR = 1.64, 95% CI = 1.35-1.99) and Guangdong population (OR = 1.68, 95% CI = 1.29-2.19). Furthermore, stratified analysis indicated that the increased susceptibility to NPC related to the -1306CC and -735CC genotype and the C(-1306)-C(-735) haplotype was more pronounced in heavier smokers. Our findings suggest that the genetic polymorphisms or haplotype in the MMP2 promoter may play a role in mediating the susceptibility to NPC in Chinese populations.

A Concise and Scalable Synthesis of High Enantiopurity (-)-D-erythro-sphingosine Using Peptidyl Thiol Ester-boronic Acid Cross-coupling

Organic Letters. Aug, 2007  |  Pubmed ID: 17608484

A short and efficient synthesis of high enantiopurity (-)-D-erythro-sphingosine has been achieved in 71% yield over 6 steps from N-Boc-L-serine. The key steps are high yield, racemization-free, palladium-catalyzed, copper(I)-mediated coupling of the thiophenyl ester of N-Boc-O-TBS L-serine with E-1-pentadecenyl boronic acid and the highly diastereoselective reduction of the resulting peptidyl ketone with LiAl(O-t-Bu)3H. By using this concise route (-)-D-erythro-sphingosine can be prepared on large scale and in high enantio- and diastereopurity (ee >99%, de up to 99%).

[Expression and Purification of Recombinant Human Cytochrome C in Escherichia Coli]

Sheng Wu Yi Xue Gong Cheng Xue Za Zhi = Journal of Biomedical Engineering = Shengwu Yixue Gongchengxue Zazhi. Jun, 2007  |  Pubmed ID: 17713275

Cytochrome C plays important roles in electron transferring, oxidative stress and apoptosis. In this study, soluble cytochrome C was accumulated in cytoplasm of E. coli by utilizing the co-expression of human cytochrome c and yeast heme lyase from a single plasmid. After ultrasonic disruption of the bacteria, a lot of contaminated proteins were discarded by addition of 350 g/L ammonium sulfate into the supernatant. Then the recombinant human cytochrome C was purified to 80% homogeneity after two times cation exchange chromatography on SP-Sepharose Fast Flow. Yields of cytochrome C greater than 10 mg per liter culture were attained. This efficient system for producing human cytochrome C is helpful for us to understand the roles of this protein in biological processes and therapy of human diseases relevant to apoptosis and oxidative stress.

[The Crystal Behavior of Calcium Carbonate in Water-soluable Chitin]

Guang Pu Xue Yu Guang Pu Fen Xi = Guang Pu. Jul, 2007  |  Pubmed ID: 17944421

Based on the basic principles of biominerlization, the paper analyses calcium carbonate crystallization in waterable chitin solution under the control of chitin, using chitin as the matrix; and analyses the effect on crystals by varying temperature or pH of the system. The obtained calcium carbonate was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electronic microscopy(SEM) and X ray powder diffraction (XRD). As a result, it was found that crystals were different formed in purity water; and the obtained crystals are different in different concentration chitin solution. Calcium carbonate has effect on chitin during the calcium carbonate formation process, so there is the interaction between chitin and calcium carbonate.

Self-assembled Epitaxial Nanocomposite BaTiO3-NiFe2O4 Films Prepared by Polymer-assisted Deposition

Journal of the American Chemical Society. Nov, 2007  |  Pubmed ID: 17973388

[A Method Base on Least Square Algorithm for Discriminating Artifacts in Dynamic Electrocardiogram Signals]

Sheng Wu Yi Xue Gong Cheng Xue Za Zhi = Journal of Biomedical Engineering = Shengwu Yixue Gongchengxue Zazhi. Oct, 2007  |  Pubmed ID: 18027690

In this paper are discussed the causes of artifacts appearing in the 24 hours' dynamic electrocardiogram. Then a new method based on the least square algorithm to discriminate the artifacts is proposed. Finally, the artifacts in the electrocardiogram (ECG) data collected from the hospital are analyzed. The results of experiment show that it is possible to quickly and effectively discriminate the artifacts caused by trembling, ill contact of electrode, and motion. The new method is conducive to ensuring clinicians' correct judgment of dynamic electrocardiogram signals.

Diagnosis of Renal Allograft Subclinical Rejection by Urine Protein Fingerprint Analysis

Transplant Immunology. Jan, 2008  |  Pubmed ID: 18047934

This study aimed to find new biomarkers and establish urine protein fingerprint model for diagnosis of renal allograft subclinical rejection (SCR).

Strain Control and Spontaneous Phase Ordering in Vertical Nanocomposite Heteroepitaxial Thin Films

Nature Materials. Apr, 2008  |  Pubmed ID: 18311144

Two-phase, vertical nanocomposite heteroepitaxial films hold great promise for (multi)functional device applications. In order to achieve practical devices, a number of hurdles need to be overcome, including the creation of ordered structures (and their formation on a large scale), achieving different combinations of materials and control of strain coupling between the phases. Here we demonstrate major advances on all these fronts: remarkable spontaneously ordered structures were produced in newly predicted compositions, vertical strain was proven to dominate the strain state in films above 20 nm thickness and strain manipulation was demonstrated by selection of phases with the appropriate elastic moduli. The work opens up a new avenue for strain control in relatively thick films and also promises new forms of ordered nanostructures for multifunctional applications.

Digital Microfluidics for Cell-based Assays

Lab on a Chip. Apr, 2008  |  Pubmed ID: 18369505

We introduce a new method for implementing cell-based assays. The method is based on digital microfluidics (DMF) which is used to actuate nanolitre droplets of reagents and cells on a planar array of electrodes. We demonstrate that this method is advantageous for cell-based assays because of automated manipulation of multiple reagents in addition to reduced reagent use and analysis time. No adverse effects of actuation by DMF were observed in assays for cell viability, proliferation, and biochemistry. A cytotoxicity assay using Jurkat T-cells was performed using the new method, which had approximately 20 times higher sensitivity than a conventional well plate assay. These results suggest that DMF has great potential as a simple yet versatile analytical tool for implementing cell-based assays on the microscale.

A Practical Interface for Microfluidics and Nanoelectrospray Mass Spectrometry

Electrophoresis. May, 2008  |  Pubmed ID: 18393343

We report a new method for fabricating nanospray ionization tips for MS, formed from glass substrates and the inert polymer, parylene-C. Using a single photolithography step, the emitters are formed contiguously with microchannels, such that no dead volumes are observed. In addition, because the devices are very thin (approximately 0.3 mm) and the tips are formed at rectangular corners, the Taylor cone volumes are small, which makes the method attractive for future integration with microfluidic separations. Device performance was demonstrated by evaluating diverse analytes, ranging from synthetic polymers, to peptides, to nucleic acids. For all analytes, performance was similar to that of conventional emitters (pulled-glass capillaries and the Agilent HPLC Chip) with the advantage of rapid, batch fabrication of identical devices.

All-terrain Droplet Actuation

Lab on a Chip. May, 2008  |  Pubmed ID: 18432335

Digital microfluidics has become a popular tool for biochemical and biomedical applications. However, its current format is restricted to actuation of droplets on a single plane. Here, we introduce a new method for fluid handling on flexible devices, which we have termed all-terrain droplet actuation (ATDA). We show that ATDA can be used to manipulate droplets across a wide range of geometries, including inclined, declined, vertical, twisted, and upside-down architectures. These new geometries enable flexible, straightforward integration of distinct physicochemical environments on monolithic devices. To illustrate this capacity, we developed temperature- and oxygen-sensitive colorimetric sensors, as well as an automated method for selective enrichment of DNA from a heterogeneous mixture. We anticipate that ATDA will be a useful new tool in the growing trend toward laboratory miniaturization.

Effect of 1-methyladenine on Double-helical DNA Structures

FEBS Letters. May, 2008  |  Pubmed ID: 18435925

Methylation at the N1 site of adenine leads to the formation of cytotoxic 1-methyladenine (m1A). Since the N1 site of adenine is involved in the hydrogen bonding of T.A and A.T Watson-Crick base pairs, it is expected that the pairing interactions will be disrupted upon 1-methylation. In this study, high-resolution NMR investigations were performed to determine the effect of m1A on double-helical DNA structures. Interestingly, instead of disrupting hydrogen bonding, we found that 1-methylation altered the T.A Watson-Crick base pair to T(anti).m1A(syn) Hoogsteen base pair, providing insights into the observed differences in AlkB-repair efficiency between dsDNA and ssDNA.

The Promotive Effects of Thymosin Beta4 on Neuronal Survival and Neurite Outgrowth by Upregulating L1 Expression

Neurochemical Research. Nov, 2008  |  Pubmed ID: 18461449

Thymosin beta(4) (Tbeta4) is a major actin-sequestering peptide widely distributed in mammalian tissues including the nervous system. The presence of this peptide in the nervous system likely plays a role in synaptogensis, axon growth, cell migration, and plastic changes in dendritic spine. However, the effects of Tbeta4 on the survival of neurons and axonal outgrowth have still not been fully understood. So far it is not clear if the effects of Tbeta4 are associated with L1 functions. In the present study, we hypothesized that Tbeta4-induced up-regulation of L1 synthesis could be involved in the survival and axon outgrowth of cultured spinal cord neurons. To test this hypothesis, primarily cultured neurons were prepared from the mouse spinal cord and treated with various concentrations of Tbeta4 ranging from 0.1 to 10 microg/ml. The analysis of L1 mRNA expression and protein synthesis in neurons was then carried out using RT-PCR and western blot assays, respectively. After the addition of Tbeta4 to cultures, cells were then treated with antibodies against distinct domains of L1-Fc. Subsequently, beta-tubulin III and L1 double-labeled indirect immunofluorescence was carried out. Meanwhile, L1 immunofluorescent reactivity was analyzed and compared in cells treated with Tbeta4. Furthermore, the number of beta-tubulin III-positive cells and neurite lengths were measured. We found that Tbeta4 enhanced L1 expression in a dose-dependent manner, and the highest L1 mRNA and protein synthesis in cells increased by more than 2.1- and 2.3-fold in the presence of Tbeta4 at identical concentrations, respectively. Moreover, it also dose dependently enhanced neurite outgrowth and neuronal survival. Compared to conditions without Tbeta4, the length of neurite and neuronal survival increased markedly in presence of 0.5, 1, and 5 microg/ml Tbeta4, respectively, whereas the effects of Tbeta4 were significantly attenuated or inhibited in the process of L1-Fc antibodies treatment. These above results indicate that the promotive effect of Tbeta4 on the survival and neurite outgrowth of cultured spinal cord neurons might be mediated, at least in part via a stimulation of the production of L1 in the neurons.

Full-wave Finite-difference Time-domain Simulation of Electromagnetic Cloaking Structures

Optics Express. Apr, 2008  |  Pubmed ID: 18545374

This paper proposes a radial dependent dispersive finite-difference time-domain method for the modeling of electromagnetic cloaking structures. The permittivity and permeability of the cloak are mapped to the Drude dispersion model and taken into account in dispersive FDTD simulations. Numerical simulations demonstrate that under ideal conditions, objects placed inside the cloak are 'invisible' to external electromagnetic fields. However for the simplified cloak based on linear transformations, the back scattering has a similar level to the case of a PEC cylinder without any cloak, rendering the object still being 'visible'. It is also demonstrated numerically that the simplified cloak based on high-order transformations can indeed improve the cloaking performance.

Femtosecond Laser-assisted Microinjection into Living Neurons

Journal of Neuroscience Methods. Sep, 2008  |  Pubmed ID: 18687359

A Ti:sapphire femtosecond laser micro-manipulation system was used to perforate vital cells. Propidium iodide was successfully transferred into both astrocytes and PC12 cells via the channel of a femtosecond laser, which induced transiently recoverable opening of the cell membrane. The transfection efficiency reached almost 100%. This method also had the advantage of contact-free, non-disruptive and stable transfection.

[On Recognizing the ECG P-wave Based on Approximating Functions in the Optimum Region]

Sheng Wu Yi Xue Gong Cheng Xue Za Zhi = Journal of Biomedical Engineering = Shengwu Yixue Gongchengxue Zazhi. Jun, 2008  |  Pubmed ID: 18693420

Aiming at the problem that it is difficult to accurately recognize the position and the figure of P wave in the ECGs easily influenced by the diversified interference,a P wave detection algorithm based on approximating functions in the optimum region is proposed in this paper. In the algorithm we use a conic to approach the P wave by means of the least square method in every region, which is shifted in local range. Then we find the optimum approach region of P wave by comparing the approximating error. Finally, we attain the characteristic points of P wave by using the approximating functions to approach P wave in the optimum region. The performance of the algorithm tested using the records of the MIT-BIH database is effective and accurate.

High-level Expression of a Functional Humanized Single-chain Variable Fragment Antibody Against CD25 in Pichia Pastoris

Applied Microbiology and Biotechnology. Nov, 2008  |  Pubmed ID: 18704398

CD25 is a marker molecule expressed on many T and B cell neoplasms and on activated T cells that mediate organ transplant rejection and many autoimmune diseases. Single-chain variable fragments (scFvs) have many advantages over whole antibodies for use in antibody-targeted immunotherapy due to their small size. Daclizumab is an Food and Drug Administration-approved humanized anti-CD25 antibody. We attempted to produce a daclizumab-derived scFv, designated as Dmab(scFv), in Pichia pastoris. The Dmab(scFv) gene was designed based on the variable regions of the heavy and light chains of daclizumab, cloned into the yeast vector pPIC9K, and expressed in P. pastoris strain GS115. Under optimized conditions (culture medium pH, 6.0-6.5; methanol concentration added daily, 3.0%; inoculum density, OD600=60; induction time point, 72-96 h), the yield of soluble recombinant Dmab(scFv) was approximately 80 mg l(-1). Flow cytometry, immunohistochemistry, and Western blotting revealed that the purified Dmab(scFv) could bind strongly to the membrane of CD25-positive cells, including SNT-8 cells, ConA-stimulated human peripheral blood mononuclear cells (hPBMCs), and rat splenocytes, but not to CD25-negative cells, including Raji cells, unstimulated hPBMCs, and rat splenocytes. These results suggest that Dmab(scFv) produced in P. pastoris is active and specific toward CD25-positive cells and has potential for use in CD25-targeted immunotherapy.

Synthesis of High Enantiopurity N-protected Alpha-amino Ketones by Thiol Ester-organostannane Cross-coupling Using PH-neutral Conditions

Organic Letters. Oct, 2008  |  Pubmed ID: 18759432

An efficient synthesis of high enantiopurity N-protected alpha-amino ketones is described. Complementing other studies using boronic acids and thiol esters, this Cu(I) diphenylphosphinate (CuDPP)-mediated, palladium-catalyzed coupling of alpha-amino thiol esters with aryl, heteroaryl, allyl, and alkenyl organostannanes gives N-protected alpha-amino ketones in high yields with high enantiopurity (in almost all cases) under mild and pH-neutral reaction conditions. The viability of pi-deficient heteroarylstannanes is an advantage of this reaction compared to the related boronic acid system.

Regioselective Esterification of Vicinal Diols on Monosaccharide Derivatives Via Mitsunobu Reactions

Organic Letters. Oct, 2008  |  Pubmed ID: 18759436

We have carried out a series of esterification reactions of secondary alcohols derived from d-glucose, d-mannose, and d-galactose via the Mitsunobu reaction. The benzoylation reaction of vicinal diols derived from monosaccharides under Mitsunobu conditions afforded monobenzoates with retention of stereochemistry only. The regioselectivity of these reactions depends on the stereochemistry of the sugar starting material. The Mitsunobu reactions on these diols may be used for the selective protection of other vicinal secondary hydroxyl groups.

No Association of MMP-7, MMP-8, and MMP-21 Polymorphisms with the Risk of Hepatocellular Carcinoma in a Chinese Population

Cancer Epidemiology, Biomarkers & Prevention : a Publication of the American Association for Cancer Research, Cosponsored by the American Society of Preventive Oncology. Sep, 2008  |  Pubmed ID: 18768525

Previous studies have suggested that the functional polymorphisms in the promoters of matrix metalloproteinases (MMP) genes were associated with the risk of cancers, but no study has ever explored these polymorphisms as risk factors for hepatocellular carcinoma. Recently, we firstly examined whether seven functional polymorphisms in the promoters of MMP-1, MMP-2, MMP-3, MMP-9, MMP-12, and MMP-13 have any bearing on the risk of hepatocellular carcinoma, but we found none. In this study, we focused on an additional six MMP polymorphisms, including four functional polymorphisms in the promoters of MMP-7 (A-181G and C-153T) and MMP-8 (C-799T and A-381G), and two nonsynonymous polymorphisms in MMP-10 (A180G) and MMP-21 (C572T). With the polymorphism validation, we found that only MMP-7 A-181G, MMP-8 C-799T, and MMP-21 C572T were polymorphic. These three polymorphisms were then genotyped in 434 patients with hepatocellular carcinoma and 480 controls by PRC-RFLP analysis. The associations between the polymorphisms and hepatocellular carcinoma risk were evaluated while controlling for confounding factors. No significant association with the risk of hepatocellular carcinoma was observed with the three polymorphisms in the overall sample, hepatitis B virus carriers, and non-hepatitis B virus carriers after correction for multiple comparisons. Furthermore, when the analyses were stratified by age, sex, status of smoking and drinking, pack-years of smoking, and family history of hepatocellular carcinoma, there was also no significant association between these polymorphisms and hepatocellular carcinoma risk. Our findings suggest that the polymorphisms MMP-7 A-181G, MMP-8 C-799T, and MMP-21 C572T may not play a major role in mediating susceptibility to hepatocellular carcinoma.

DNA Methylation in ES Cells Requires the Lysine Methyltransferase G9a but Not Its Catalytic Activity

The EMBO Journal. Oct, 2008  |  Pubmed ID: 18818693

Histone H3K9 methylation is required for DNA methylation and silencing of repetitive elements in plants and filamentous fungi. In mammalian cells however, deletion of the H3K9 histone methyltransferases (HMTases) Suv39h1 and Suv39h2 does not affect DNA methylation of the endogenous retrovirus murine leukaemia virus, indicating that H3K9 methylation is dispensable for DNA methylation of retrotransposons, or that a different HMTase is involved. We demonstrate that embryonic stem (ES) cells lacking the H3K9 HMTase G9a show a significant reduction in DNA methylation of retrotransposons, major satellite repeats and densely methylated CpG-rich promoters. Surprisingly, demethylated retrotransposons remain transcriptionally silent in G9a(-/-) cells, and show only a modest decrease in H3K9me2 and no decrease in H3K9me3 or HP1alpha binding, indicating that H3K9 methylation per se is not the relevant trigger for DNA methylation. Indeed, introduction of catalytically inactive G9a transgenes partially 'rescues' the DNA methylation defect observed in G9a(-/-) cells. Taken together, these observations reveal that H3K9me3 and HP1alpha recruitment to retrotransposons occurs independent of DNA methylation in ES cells and that G9a promotes DNA methylation independent of its HMTase activity.

Wireless Body Sensor Networks for Health-monitoring Applications

Physiological Measurement. Nov, 2008  |  Pubmed ID: 18843167

Current wireless technologies, such as wireless body area networks and wireless personal area networks, provide promising applications in medical monitoring systems to measure specified physiological data and also provide location-based information, if required. With the increasing sophistication of wearable and implantable medical devices and their integration with wireless sensors, an ever-expanding range of therapeutic and diagnostic applications is being pursued by research and commercial organizations. This paper aims to provide a comprehensive review of recent developments in wireless sensor technology for monitoring behaviour related to human physiological responses. It presents background information on the use of wireless technology and sensors to develop a wireless physiological measurement system. A generic miniature platform and other available technologies for wireless sensors have been studied in terms of hardware and software structural requirements for a low-cost, low-power, non-invasive and unobtrusive system.

Characterization of Two Glutaminases from the Filamentous Cyanobacterium Anabaena Sp. PCC 7120

FEMS Microbiology Letters. Dec, 2008  |  Pubmed ID: 19054111

The Anabaena genome contains two ORFs that appear to encode glutaminases. The genes were expressed as histidine-tagged fusion proteins in Escherichia coli. The purified proteins possessed glutaminase activity using l-glutamine as the substrate, but differed in biochemical properties. All2934 showed an optimal activity at 20 degrees C and pH 6.0, with a higher affinity for l-glutamine than All4774, which had optimal activity at 37 degrees C and pH 7.5. Remarkably, the glutaminase activity of All2934 was phosphate dependent, while All4774 was phosphate independent. The expression of all2934 and all4774 was analyzed using semi-quantitative reverse transcriptase-PCR. The expression level of all2934 was much higher than that of all4774 under normal and nitrogen-depletion conditions, indicating that All2934 may play an important role in metabolizing glutamine in Anabaena.

Lack of Association Between the Functional Polymorphisms in the Estrogen-metabolizing Genes and Risk for Hepatocellular Carcinoma

Cancer Epidemiology, Biomarkers & Prevention : a Publication of the American Association for Cancer Research, Cosponsored by the American Society of Preventive Oncology. Dec, 2008  |  Pubmed ID: 19064581

Estrogens have been proposed to act as tumor promoters and induce hepatocarcinogenesis. Recently, we observed a significant association between the risk for hepatocellular carcinoma and the polymorphisms of the estrogen receptor (ESR) alpha (ESR1) gene, supporting the hypothesis of involvement for the estrogen-ESR axis in the estrogen-induced hepatocarcinogenesis. In this study, based on another hypothesis in which estrogen metabolites can directly cause DNA damage and affect tumor initiation, we examined whether the polymorphisms of the estrogen-metabolizing enzymes (EME), which are involved in biogenesis (CYP17, CYP19), bioavailability (CYP1A1, CYP1B1), and degradation (catechol-O-methyltransferase) of the estrogens, have any bearing on the risk for hepatocellular carcinoma. Seven functional polymorphisms in five EMEs (CYP17 MspAI site, CYP19 Trp39Arg, Ile462Val and MspI site in CYP1A1, CYP1B1 Val432Leu, and Ala72Ser and Val158Met in catechol-O-methyltransferase) were genotyped in 434 patients with hepatocellular carcinoma and 480 controls by PCR-RFLP analysis. The associations between the polymorphisms and hepatocellular carcinoma risk were evaluated while controlling for confounding factors. No significant association with the risk for hepatocellular carcinoma was observed with the seven polymorphisms in hepatitis B virus carriers and non-hepatitis B virus carriers after correction for multiple comparisons. After stratification by common confounding factors of hepatocellular carcinoma, the EME polymorphism remained no significant association with the hepatocellular carcinoma risk. Furthermore, no signs of gene-gene interactions were observed for each combination of the seven polymorphisms. Our findings suggest that the polymorphisms of EMEs may not contribute significantly to the risk for hepatocellular carcinoma.

[Microstrip Antenna Design and System Research of Radio Frequency Identification Temperature Sensor]

Sheng Wu Yi Xue Gong Cheng Xue Za Zhi = Journal of Biomedical Engineering = Shengwu Yixue Gongchengxue Zazhi. Dec, 2008  |  Pubmed ID: 19166222

Radio frequency identification sensor network, which is a product of integrating radio frequency identification (RFID) with wireless sensor network (WSN), is introduced in this paper. The principle of radio frequency identification sensor is analyzed, and the importance of the antenna is emphasized. Then three kinds of common antennae, namely coil antenna, dipole antenna and microstrip antenna, are discussed. Subsequently, according to requirement, we have designed a microstrip antenna in a wireless temperature-monitoring and controlling system. The measurement of factual effect showed the requirement was fulfilled.

A Sensitive and Specific Liquid Chromatography/tandem Mass Spectrometry Method for Determination of Echinacoside and Its Pharmacokinetic Application in Rats

Biomedical Chromatography : BMC. Jun, 2009  |  Pubmed ID: 19277965

A rapid and sensitive method based on liquid chromatography/tandem mass spectrometry (LC/MS/MS) for the determination of echinacoside in rat plasma was established and fully validated. A single step of liquid-liquid extraction with n-butanol was utilized. Chromatographic separation of the analyte and the internal standard (IS), chlorogenic acid, from the sample matrix was performed using a Capcell-MG C(18) analytical column (100 2.0 mm x 5 microm), with a gradient of acetonitrile and water containing 0.1% acetic acid as the mobile phase. Detection was performed on a triple quadrupole tandem mass spectrometer equipped with electrospray ionization source operated in negative ion selected reaction monitoring mode. The method was linear in the concentration range 10-2500 ng/mL. The deviations of both intra- and inter-day precisions (RSD) were 7.1% and the assay accuracies were within 99.2-106.5%. Echinacoside proved to be stable during sample storage, preparation and analysis when an antioxidant solution was used. The method was successfully applied to a pharmacokinetic study in rats after an intragastric administration of echinacoside (100 mg/kg). With the lower limit of quantification at 10 ng/mL, this method proved to have sufficient selectivity, sensitivity and reproducibility for the pharmacokinetic study of echinacoside.

Enhancement of Evanescent Spatial Harmonics Inside Media with Extreme Optical Anisotropy

Optics Letters. Feb, 2009  |  Pubmed ID: 19373363

Significant enhancement of evanescent spatial harmonics inside the slabs of media with extreme optical anisotropy is revealed. This phenomenon results from the pumping of standing waves and has the feature of being weakly sensitive to the material losses. Such characteristics may enable subwavelength imaging at considerable distances away from the objects.

Effect of 1-methyladenine on Thermodynamic Stabilities of Double-helical DNA Structures

FEBS Letters. May, 2009  |  Pubmed ID: 19376116

1-Methyladenine (m1A) alters T.A Watson-Crick to T.m1A Hoogsteen base pair. Owing to its conversion to N6-methyladenine (m6A) at higher temperatures, thermodynamic studies of m1A-containing DNAs using conventional melting methods are subject to the influence of m6A species. In this study, we applied nuclear magnetic resonance spectroscopy to determine the base pairing modes and effect of m1A on thermodynamic stability of double-helical DNA. The observed base pairing modes account for the destabilizing trend which follows the order T.m1A approximately G.m1A

Suppressive Effects of Swainsonine on C6 Glioma Cell in Vitro and in Vivo

Phytomedicine : International Journal of Phytotherapy and Phytopharmacology. Nov, 2009  |  Pubmed ID: 19427771

Swainsonine, an extract from Astragalus membranaceus, is known for its anti-cancer effects and could prevent metastases. In order to investigate the effects and mechanisms of swainsonine in C6 glioma cells, we carry out correlated experiments in vitro and in vivo. After treatment with swainsonine, the effective dose and IC(50) value of swainsonine in the C6 glioma cell were examined using the MTT assay. Cell cycle distribution and apoptotic rates were analyzed using FCM and [Ca(2+)](i) was measured by LSCM. Expressions of p16 and p53 protein were evaluated by immunocytochemical methods. Simultaneously, glioma-bearing rats were administered swainsonine at doses of 2, 4 and 8 mg/kg body wt. The inhibition rate was calculated and pathological sections were observed. The results indicated that the growth of C6 glioma cells is inhibited by swainsonine in vitro, with an IC(50) value within 24h of 0.05 microg/ml. Increases in swainsonine correlate with S phase percentages of 11.3%, 11.6% and 12.4%, respectively. Moreover, the expression of apoptosis inhibiting p53 and p16 protein decreases gradually. Tumor weight in vivo decreased clearly and HE dyeing of tumor tissue showed gray, its texture was soft, with necrosis and hemorrhagic concentrated inward. Swainsonine could inhibit the proliferation of C6 glioma cells in vitro and the growth of C6 glioma in vivo. The mechanisms of swainsonine-induced apoptosis may relate with the expression of apoptosis-related genes and overloading-[Ca(2+)](i)-induced endoplasmic reticulum stress.

Manipulating the Loss in Electromagnetic Cloaks for Perfect Wave Absorption

Optics Express. May, 2009  |  Pubmed ID: 19434181

We examine several ways to manipulate the loss in electro-magnetic cloaks, based on transformation electromagnetics. It is found that, by utilizing inherent electric and magnetic losses of metamaterials, perfect wave absorption can be achieved based on several popular designs of electromagnetic cloaks. A practical implementation of the absorber, consisting of ten discrete layers of metamaterials, is proposed. The new devices demonstrate super-absorptivity over a moderate wideband range, suitable for both microwave and optical applications. It is corroborated that the device is functional with a subwavelength thickness and, hence, advantageous compared to the conventional absorbers.

Synthesis and Characterization of Monosaccharide-derived Carbamates As Low-molecular-weight Gelators

Langmuir : the ACS Journal of Surfaces and Colloids. Aug, 2009  |  Pubmed ID: 19449815

Sugar-based low-molecular-weight gelators are an interesting new class of compounds that are important in supramolecular chemistry and for the preparation of advanced materials. Previously, we synthesized a series of ester and carbamate derivatives of 4,6-O-benzylidene methyl-alpha-D-glucopyranoside and found that monosubstituted alkynyl esters with five to seven carbons and monosubstituted carbamates with saturated five- and seven-carbon chains are good gelators. To understand the structural requirement for the gelation of the carbamate derivatives (O-linked carbamates), a diverse series of analogs, including alkynyl, aryl, and alkyl halide derivatives, were prepared and analyzed. We found that for gelation the O-linked carbamate derivatives have different structural preferences than the ester derivatives. To exhibit gellation, the ester analogs favor alkyl-containing terminal acetylene groups and the carbamoyl derivatives prefer saturated hydrocarbons. Both the esters and the carbamates showed good gelation properties when they were functionalized with aryl side chains. We also synthesized and screened a new series of carbamates (N-linked carbamates) in which the nitrogen atom of the carbamate group is directly attached to the sugar ring. The N-linked carbamates are good gelators for aqueous DMSO and ethanol solutions, and two of the compounds are also able to form gels in pure water. Optical microscopy and scanning electron microscopy were used to characterize several representative gels. In general, long, narrow, uniform fibrous networks were observed for effective gelators. The structure-gelation correlation obtained here can be used in the design of new sugar-based low-molecular-weight gelators.

A World-to-chip Interface for Digital Microfluidics

Analytical Chemistry. Feb, 2009  |  Pubmed ID: 19115860

Digital microfluidics (DMF) is a fluid handling technique that enables manipulation of discrete droplets on an array of electrodes. There is considerable enthusiasm for this method because of the potential for array-based screening applications. A limitation for DMF is nonspecific adsorption of reagents to device surfaces. If a given device is used to actuate multiple reagents, this phenomenon can cause undesirable cross-contamination. A second limitation for DMF (and all other microfluidic systems) is the "world-to-chip" interface; it is notoriously difficult to deliver reagents and samples to such systems without compromising the oft-hyped advantages of rapid analyses and reduced reagent consumption. We introduce a new strategy for digital microfluidics, in which a removable plastic "skin" is used to (a) eliminate cross-contamination and (b) bridge the world-to-chip interface. We demonstrated the utility of this format by implementing on-chip protein digestion on immobilized enzyme depots. This new method has the potential to transform DMF from being a curiosity for aficionados into a technology that is useful for biochemical applications at large.

A Strategy to Control Transmission of Schistosoma Japonicum in China

The New England Journal of Medicine. Jan, 2009  |  Pubmed ID: 19129526

Schistosoma japonicum causes an infection involving humans, livestock, and snails and is a significant cause of morbidity in China.

De-differentiation Response of Cultured Astrocytes to Injury Induced by Scratch or Conditioned Culture Medium of Scratch-insulted Astrocytes

Cellular and Molecular Neurobiology. Jun, 2009  |  Pubmed ID: 19130217

Our previous reports indicated that astrocytes (ASTs) in injured adult rat spinal cord underwent a process of de-differentiation, and may acquire the potential of neural stem cells (NSCs). However, the AST de-differentiation and transitional rejuvenation process following injury is still largely unclear. The aim of the present study was to determine whether injured in vitro ASTs can re-enter the multipotential-like stem cell pool and regain NSC characteristics, and to further understand the mechanism of AST de-differentiation. We used an in vitro scratch-wound model to evoke astrocytic response to mechanical injury. GFAP and nestin double-labeled indirect immunofluorescence were carried out to characterize these scratched cells at various periods. Western-blot analysis was used to determine the changes of GFAP and nestin expression following injury. Furthermore, the rate of proliferation was determined by immunocytochemical detection of BrdU incorporating cells. These scratch-wound ASTs were cultured with stem cells medium to explore their ability to generate neurospheres and examine the self-renewal and multi-potency of such neurospheres. Moreover, scratched AST culture supernatant as conditioned cultured medium (ACM) was used to investigate if some diffusible factors derived from injured ASTs could induce de-differentiation of AST. The results showed: (1) the nestin positivity first appeared in GFAP-positive cells at the edge of the scratch, subsequently, disseminated into un-insulted zone. The expression of nestin in AST was increased with longer culture, while that of GFAP was decreased. Furthermore, these nestin-immunoreactive ASTs could generate neurospheres, which showed self-renewal and could be differentiated into neurons, ASTs and oligodendrocytes. (2) Scratched ASTs culture supernatant can induce astrocytic proliferation and de-differentiation. These results reveal that the in vitro injured ASTs can de-differentiate into nestin-positive stem/precursor cells, the process of de-differentiation may arise from direct injury or some diffusible factors released from injured ASTs.

A Copper-catalyzed, PH-neutral Construction of High-enantiopurity Peptidyl Ketones from Peptidic S-acylthiosalicylamides in Air at Room Temperature

Angewandte Chemie (International Ed. in English). 2009  |  Pubmed ID: 19145620

A copper-catalyzed transformation of peptidic thiol esters and boronic acids gives peptidyl ketones and takes place in DMF or DMF/H(2)O at room temperature in air (see scheme). This aerobic reaction only occurs at a thiol ester group capable of coordinating to Cu through its appendage on the sulfur center and is not hampered by racemization of the reactants or products.

Semen Quality of 1346 Healthy Men, Results from the Chongqing Area of Southwest China

Human Reproduction (Oxford, England). Feb, 2009  |  Pubmed ID: 19049989

Large studies on semen quality of the general healthy population from China are rare.

[Design and Implementation of a New Type Excitation Source and the Optimal Excitation Coil for MIT]

Sheng Wu Yi Xue Gong Cheng Xue Za Zhi = Journal of Biomedical Engineering = Shengwu Yixue Gongchengxue Zazhi. Apr, 2009  |  Pubmed ID: 19499777

This research work was aimed to improve the performance of magnetic induction tomography (MIT) system by designing a high-performance excitation source and the optimal excitation coil. A new type excitation source with adjustable output was designed, and then the power circuit was simulated by the software ICPA. Focused and solenoid coils were designed in accordance with the design principle of coil, then the optimal excitation coil was proved by measuring the magnetic field distribution and the experimentation of phase detection using neuron cell models. At the stated excitation frequency, the parameters of the excitation source are output power 0.035 W-31.4 W, steady output peak current over 1 A, frequency stability 10(-9), and THD amplitude less than -51dB. When compared with other coils, the focused discal excitation coil is most effective for phase detection with the use of neuron cell models. The excitation source can produce the stated frequency sine wave with higher frequency stability, lower THD and wider adjustable output power. The phase difference between normal cell model and edema cell model was more significant by measurement using focused discal coil.

[Experimental Study on Repairing Segmental Bone Defects by Biphasic Ceramic-like Biologic Bone]

Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi = Zhongguo Xiufu Chongjian Waike Zazhi = Chinese Journal of Reparative and Reconstructive Surgery. May, 2009  |  Pubmed ID: 19514587

To evaluate the osteogenesis of biphasic ceramic-like biologic bone (BCBB) with tissue engineering in repairing segmental bone defects.

High-level Expression of a Functional Humanized Anti-CTLA4 Single-chain Variable Fragment Antibody in Pichia Pastoris

Applied Microbiology and Biotechnology. Feb, 2009  |  Pubmed ID: 18936937

The administration of antibodies against the cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) is a promising approach in the upregulation of immune responses in many cancers and infectious diseases. The single-chain variable fragment of antibody against CTLA4 is also useful in developing immunotoxins that might be used in the treatment of cancer, transplant rejection, and autoimmune diseases. Here, we report the production of a soluble and functional scFv antibody against CTLA4 by using Pichia pastoris as the expression system. The gene encoding scFv hS83 with an additional 6His-tag at the 5'-end was inserted into the expression vector pPIC9K. Then, the transformants were double-screened on plates containing 0.25 mg/mL and 1.5 mg/mL of neomycin G418 and many clones with different levels of G418-resistance were selected for further studies on expression. After induction by the addition of methanol, various levels of hS83 were detected in the supernatant of P. pastoris containing pPIC9K-hS83. Clones with low G418-resistance produced more hS83 than those with higher G418-resistance. Under the optimized conditions (initial inoculum, 40 A(600nm) AU/mL; pH 6.0; methanol concentration, 3.0%; induction time, 72 h), approximately 16-20 mg protein could be recovered from 1 L of the culture. The purified hS83 had a stronger binding ability towards CTLA4-positive Raji cells than CTLA4-negative ECV304 cells. This finding indicates that the antibody produced by P. pastoris is functional and may be used in immunotherapy for cancer, infection, transplant rejection, and autoimmune diseases.

[Study of Supercontinuum in Nanofiber]

Guang Pu Xue Yu Guang Pu Fen Xi = Guang Pu. Apr, 2009  |  Pubmed ID: 19626862

Using split-step Fourier transform method, the authors performed the simulation on supercontinuum generation (SCG) of femtosecond laser in nanofiber. The effects of diameter of the nanofiber, peak power and input pulse duration on the supercontinuum generation were analyzed. The results show that the higher the peak power of the input pulse, the easier the supercontinuum generation could be observed; the narrower the input pulse, the wider the light spectrum width. The dimension of the nanofiber plays an very important role in supercontinuum generaion of femtosecond laser pulse, the supercontinuum generation is not inversely proportional to the diameter of nanofiber, and there is a optimum diameter of nanofiber for the certain input laser pulse, so that the supercontinuum generation can be noteworthy. The obtained results in this paper would be helpful for further research on and making use of the supercontinuum generation in nanofiber.

Spontaneous Ordering, Strain Control, and Multifunctionality in Vertical Nanocomposite Heteroepitaxial Films

IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control. Aug, 2009  |  Pubmed ID: 19686968

Two-phase nanocomposite heteroepitaxial films with vertical microstructures hold great promise for various (multi)functional (e.g., multiferroic) electronic device applications. With the aim of creating addressable arrays, it is necessary to form spontaneously ordered structures over large areas. However, such structures have not, so far, been demonstrated. We have recently produced remarkable spontaneously ordered phase assemblies and find that these structures form concomitantly with 2-D vertical strain control, i.e., strain in the 2 phases is controlled along the vertical interface between them rather than being influenced by the substrate. In this paper, we report on our findings in the BiFeO3 and BaTiO3 ferroelectric systems.

China's New Strategy to Block Schistosoma Japonicum Transmission: Experiences and Impact Beyond Schistosomiasis

Tropical Medicine & International Health : TM & IH. Dec, 2009  |  Pubmed ID: 19793080

Despite sustained efforts for its control made over the past 50+ years, the re-emergence of schistosomiasis in China was noted around the turn of the new millennium. Consequently, a new integrated strategy was proposed to stop the contamination of schistosome eggs to the environment, which emphasizes health education, access to clean water and adequate sanitation, mechanization of agriculture and fencing of water buffaloes, along with chemotherapy. Validation of this integrated control strategy in four pilot counties in the provinces of Anhui, Hubei, Hunan and Jiangxi revealed significant reductions in the rate of Schistosoma japonicum infection in humans and intermediate host snails. Importantly, this strategy showed an impact on diseases beyond schistosomiasis, signified by concomitant reductions in the prevalence of soil-transmitted helminth infections. In view of China's new integrated strategy for transmission control of schistosomiasis showing an ancillary benefit on other helminthic diseases, we encourage others to investigate the scope and limits of integrated control of neglected tropical diseases.

[Quantitative Input of Atmospheric Nitrogen to an Agro-ecosystem in a Typical Red Soil Region]

Huan Jing Ke Xue= Huanjing Kexue / [bian Ji, Zhongguo Ke Xue Yuan Huan Jing Ke Xue Wei Yuan Hui "Huan Jing Ke Xue" Bian Ji Wei Yuan Hui.]. Aug, 2009  |  Pubmed ID: 19799278

The atmospheric nitrogen (N) deposition flux and dry deposition N velocities (Vd) were estimated using big leaf resistance analogy model by observations of onflow and factors of farmland microclimate, analysis of nitrides from the atmosphere and rain in an agro-ecosystem, a typical red soil region on Experiment Station of Red Earth Ecology, Chinese Academy (Yingtan, Jiangxi) of Sciences in 2005. The results showed that the dry deposition N was 82.63 kg x hm(-2), accounting for 67.94% of the total N, which was 132.6 kg x hm(-2) in the whole year (2005). In N dry deposition progress, NH3-N and NO3- -N were the main settlement for gas and particle, respectively. NH3-N was made up 43.02% to 89.89% (mean value, 71.05%) of the gaseous N deposition while NO3- -N was accounted for 33.67% to 94.54% (mean value, 61.01%) of the particle N deposition. The N wet deposition fluxes were 0.50-8.45 kg x hm(-2) per month and reached the higher value in July and November.

An Approach to Identifying Sequential Metabolites of a Typical Phenylethanoid Glycoside, Echinacoside, Based on Liquid Chromatography-ion Trap-time of Flight Mass Spectrometry Analysis

Talanta. Dec, 2009  |  Pubmed ID: 19836522

Metabolite identification for the compounds that undergo multiple and sequential metabolism is still a great challenge. Echinacoside (ECH), a typical phenylethanoid glycoside, contains multiple unstable chemical bonds and high reactive functional groups which are susceptible to multiple pathways of degradation and metabolism, leading great difficulties for its metabolite identification. This study proposed a novel approach for rapidly identifying the complicated and unpredictable metabolites of ECH, based on the powerful liquid chromatography hybrid ion trap and time of flight mass spectrometry (LC/MS-IT-TOF) analysis. Four degradation products were rapidly identified via the "fragmentation-degradation" comparisons. Five phase I and phase II metabolites of the degradation products were rapidly characterized via the crossover mass differences comparisons of their quasi-molecular ions with the potential precursors. Four direct phase I and phase II metabolites of the parent compound were identified by the mass differences analysis of the molecular ions between metabolites and the parent compound. Multiple stages of fragmentation patterns were used to confirm the metabolites characterizations. This study provides a novel approach to characterizing the complicated metabolites, and would be widely applicable for the metabolite identification of natural products.

Association of DLC1 Gene Polymorphism with Susceptibility to Hepatocellular Carcinoma in Chinese Hepatitis B Virus Carriers

Cancer Epidemiology. Oct, 2009  |  Pubmed ID: 19766077

Lost or downexpression of the gene deleted in liver cancer 1 (DLC1) has been implicated in the development of hepatocellular carcinoma (HCC). We examined the relationship between DLC1 polymorphisms and HCC risk among Chinese.

[The Study on Supercontinuum Generation of Femtosecond Pulse Propagating in Fused Silica]

Guang Pu Xue Yu Guang Pu Fen Xi = Guang Pu. Sep, 2009  |  Pubmed ID: 19950659

Starting from Nonlinear Schrodinger's equation and using the split-step Fourier method, the authors studied the characters of the supercontinuum generation of femtosecond laser pulse propagating in fused silica, and many physical factors were included such as propagation distance, input pulse peak power, diffraction effect, dispersion effect andnonlinear effect etc. The results show that when the femtosecond pulse propagated inside the fused silica, the process of supercontinuum generation could be divided into two main stages: the pulse compression stage, which was induced by the self-focus and other third nonlinear effects of the fused silica; and the pulse split stage, which was caused by the self-phase modulation and the group velocity dispersion of the fused silica. When the femtosecond pulse propagated inside the fused silica with high input peak power, the 3rd-order nonlinear effect of material induced pulse compression and then the subpulses were produced, so that new frequency components were introduced. At the same time, the authors also studied the spectral distribution of the pulse at different spacial locations, and there are new frequencies around the central frequency. Finally, some experiments were done to demonstrate the supercontinuum generation.

Brain Tumor Stem-Like Cells Identified by Neural Stem Cell Marker CD15

Translational Oncology. Dec, 2009  |  Pubmed ID: 19956386

In recent years, a small number of cells that have stem cell properties were identified in human gliomas called brain tumor stem cells (BTSCs), which were thought to mainly contribute to the initiation and development of gliomas and could be identified by the surface marker CD133. However, recent studies indicated that the expression of CD133 might be regulated by environmental conditions such as hypoxia and that there might be CD133(-) BTSCs. Genetic mouse models demonstrated that some gliomas originated from transformed neural stem cells (NSCs). Therefore, we investigated the expression of CD15, a surface marker for NSCs, in tumor spheres derived from astrocytoma and ependymoma. CD15(+) cells isolated from these tumor spheres had properties of BTSCs including self-renewal, multidifferentiation, and the ability to recapitulate the phenocopy of primary tumors. CD15 exhibited stable expression in long-term cultured tumor spheres, which sustained BTSCs properties, whereas CD133 expression decreased significantly in late passages. Furthermore, CD15(+)CD133(-) cells isolated from early or late passages of tumor spheres showed similar characteristics of BTSCs. Examination of glioma samples by immunohistochemistry showed that CD15 was expressed in a subset of human brain tumors. Therefore, CD15 can be used as a marker of stem-like cells derived from brain tumors that might contain CD133(-) BTSCs.

Functional Contrast and Kinetic Analysis of Water-dispersible Carbon Black Nanoparticles and MWNTs in Glucose Biosensors

Conference Proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference. 2009  |  Pubmed ID: 19965278

Poly (sodium 4-styrenesulfonate) (PSS) was grafted onto carbon black surface by ambient surface-initiated atom radical transfer polymerization. And the carbon paste electrodes modified by CB-g-PSS and MWNTs were completed. CB-g-PSS and MWNTs had no effect on direct electron transfer based on the carbon paste electrode, but increased the redox speed of Fe [(CN)(6)](3-) / Fe[(CN)(6)](4-) and led to stronger current response. The experimental results indicate that the sensitivity of modified by CB-g-PSS is 2.1 times of no modified, and MWNTs is 4 times. Measurable linear range is 1.1 mmol/L approximately 33.3 mmol/L. For sensors modified by CB-g-PSS, testing of different concentration glucose: RSD<7%; sensors modified by MWNTs, RSD<7.5% (glucose < 15 mmol/L), RSD<10% (glucose > 15 mmol/L) respectively.

Droplet-scale Estrogen Assays in Breast Tissue, Blood, and Serum

Science Translational Medicine. Oct, 2009  |  Pubmed ID: 20368154

Estrogen is a key hormone in human reproductive physiology, controlling ovulation and secondary sexual characteristics. In addition, it plays an important role in the pathogenesis of breast cancer. Indeed, estrogen receptor antagonists and aromatase inhibitors (which block estrogen biosynthesis) are primary drugs used for treatment and prevention in at-risk populations. Despite its importance, tissue concentrations of estrogen are not routinely measured because conventional techniques require large samples of biopsies for analysis. In response to this need, we have developed a digital microfluidic method and applied it to the extraction and quantification of estrogen in 1-microliter samples of breast tissue homogenate (as would be collected with fine-needle aspiration), as well as in whole blood and serum. This method may be broadly applicable to conditions requiring frequent analysis of hormones in clinical samples (for example, infertility and cancer).

A Quick and Parallel Analytical Method Based on Quantum Dots Labeling for ToRCH-Related Antibodies

Nanoscale Research Letters. 2009  |  Pubmed ID: 20652102

Quantum dot is a special kind of nanomaterial composed of periodic groups of II-VI, III-V or IV-VI materials. Their high quantum yield, broad absorption with narrow photoluminescence spectra and high resistance to photobleaching, make them become a promising labeling substance in biological analysis. Here, we report a quick and parallel analytical method based on quantum dots for ToRCH-related antibodies including Toxoplasma gondii, Rubella virus, Cytomegalovirus and Herpes simplex virus type 1 (HSV1) and 2 (HSV2). Firstly, we fabricated the microarrays with the five kinds of ToRCH-related antigens and used CdTe quantum dots to label secondary antibody and then analyzed 100 specimens of randomly selected clinical sera from obstetric outpatients. The currently prevalent enzyme-linked immunosorbent assay (ELISA) kits were considered as "golden standard" for comparison. The results show that the quantum dots labeling-based ToRCH microarrays have comparable sensitivity and specificity with ELISA. Besides, the microarrays hold distinct advantages over ELISA test format in detection time, cost, operation and signal stability. Validated by the clinical assay, our quantum dots-based ToRCH microarrays have great potential in the detection of ToRCH-related pathogens.

7-Chloro-4-phenethyl-2H-1,4-benzoxazin-3(4H)-one

Acta Crystallographica. Section E, Structure Reports Online. 2009  |  Pubmed ID: 21582449

In the crystal structure of title compound, C(16)H(14)ClNO(2), the dihedral angle between the aromatic rings is 4.2 (2)°.

4-Benzyl-7-chloro-2H-1,4-benz-oxazin-3(4H)-one

Acta Crystallographica. Section E, Structure Reports Online. 2009  |  Pubmed ID: 21583841

In the title compound, C(15)H(12)ClNO(2), the two benzene rings are nearly perpendicular to each other [dihedral angle = 89.99 (13)°]. The O atom of the six-membered heterocyclic ring is disordered over two sites in a ratio of 0.46 (4):0.54 (4) and is displaced from the mean plane formed by other five atoms, resulting an envelope conformation of the six-membered hetercycle ring.

Methyl 2-(tert-but-oxy-carbonyl-amino)-1,3-thia-zole-5-carboxyl-ate

Acta Crystallographica. Section E, Structure Reports Online. 2010  |  Pubmed ID: 21588688

The title compound, C(10)H(14)N(2)O(4)S, was synthesized by the reaction of methyl 2-amino-thia-zole-5-carboxyl-ate and di-tert-butyl carbonate. In this structure, the thia-zole ring is planar (mean deviation = 0.0011 Å). Two weak intra-molecular C-H⋯O hydrogen bonds are formed between two of the methyl groups and one carbonyl O atom, resulting in the formation of two twisted six-membered rings. Inter-molecular N-H⋯N hydrogen bonds link the mol-ecules to form centrosymmetric dimeric units, and the hydrogen-bond scheme is completed by inter-molecular C-H⋯O contacts.

Folded Emitters for Nanoelectrospray Ionization Mass Spectrometry

Rapid Communications in Mass Spectrometry : RCM. Dec, 2010  |  Pubmed ID: 21072798

Electrospray ionization (ESI) has revolutionized mass spectrometry (MS), providing a facile method for the ionization of macromolecules for analysis by mass. The development of nanoESI-MS has further extended the utility of ESI-MS, permitting the analysis of small-volume samples with enhanced sensitivity over conventional ESI-MS. Traditional nanoESI-MS experiments use pulled-glass capillary emitters, which are expensive to purchase and require specialized instruments and training to fabricate in-house. Furthermore, these emitters suffer from problems including clogging, sample contamination, and irreproducible spray stability. Here, we report a new emitter for nanoESI-MS, made by folding small pieces of polyimide tape. In comparison with conventional pulled-glass capillary emitters, the new emitters are inexpensive and simple to make. Their low cost makes them disposable after a single use, such that sample contamination or clogging is never a problem. Emitter performance has been evaluated for diverse analytes encompassing a large mass range, including small molecules, peptides, proteins, and synthetic polymers. In all cases, the performance is similar to that of pulled-glass capillary emitters, with the advantages of low cost, ease of use, and disposability.

[The Analysis of Consistency Between HJ-1B and Landsat 5 TM for Retrieving LST Based on the Single-channel Algorithm]

Guang Pu Xue Yu Guang Pu Fen Xi = Guang Pu. Dec, 2010  |  Pubmed ID: 21322224

To ascertain whether the thermal infrared image of HJ-1B which has the similar sensor parameter and setting to Landsat 5 TM6 image is applicable for retrieving the land surface temperature (LST), a comparison of retrieved LST between two types of sensors was conducted. Two scenes of thermal infrared images that came from different sensors were acquired in 5th, Apr 2009, which covered the same region in Beijing. To retrieve LST, a generalized single-channel algorithm developed by Jiménez-Muñoz and Sobrino was applied. The LST of study area for both images was thus generated. Based on the LST mapping results and corresponding statistics, an apparent trend could be observed which indicated the consistency in both LST value and its spatial distribution. Consequently, the performance of HJ-IB IRS serving as the data source for LST retrieval was assessed and illustrated in this study. Besides, a high temporal resolution as well as wide swath of the HJ-IRS data suggested its potential in application.

Detecting Vital Signs with Wearable Wireless Sensors

Sensors (Basel, Switzerland). 2010  |  Pubmed ID: 22163501

The emergence of wireless technologies and advancements in on-body sensor design can enable change in the conventional health-care system, replacing it with wearable health-care systems, centred on the individual. Wearable monitoring systems can provide continuous physiological data, as well as better information regarding the general health of individuals. Thus, such vital-sign monitoring systems will reduce health-care costs by disease prevention and enhance the quality of life with disease management. In this paper, recent progress in non-invasive monitoring technologies for chronic disease management is reviewed. In particular, devices and techniques for monitoring blood pressure, blood glucose levels, cardiac activity and respiratory activity are discussed; in addition, on-body propagation issues for multiple sensors are presented.

[Improved Angiogenesis by P-selectin Glycoprotein Ligand-1 Overexpression in Endothelial Progenitor Cells]

Zhonghua Bing Li Xue Za Zhi Chinese Journal of Pathology. Sep, 2010  |  Pubmed ID: 21092591

To explore whether overexpression of P-selectin glycoprotein ligand-1 (PSGL-1) promotes the adhesive ability of endothelial progenitor cells and functionally facilitates neovascularization in mouse model of hindlimb ischemia.

Contributions of International Cooperation Projects to the HIV/AIDS Response in China

International Journal of Epidemiology. Dec, 2010  |  Pubmed ID: 21113032

For 20 years, China has participated in 267 international cooperation projects against the HIV/AIDS epidemic and received ∼526 million USD from over 40 international organizations. These projects have played an important role by complementing national efforts in the fight against HIV/AIDS in China.

Scaling Up the National Methadone Maintenance Treatment Program in China: Achievements and Challenges

International Journal of Epidemiology. Dec, 2010  |  Pubmed ID: 21113034

China's methadone maintenance treatment program was initiated in 2004 as a small pilot project in just eight sites. It has since expanded into a nationwide program encompassing more than 680 clinics covering 27 provinces and serving some 242 000 heroin users by the end of 2009. The agencies that were tasked with the program's expansion have been confronted with many challenges, including high drop-out rates, poor cooperation between local governing authorities and poor service quality at the counter. In spite of these difficulties, ongoing evaluation has suggested reductions in heroin use, risky injection practices and, importantly, criminal behaviours among clients, which has thus provided the impetus for further expansion. Clinic services have been extended to offer clients a range of ancillary services, including HIV, syphilis and hepatitis C testing, information, education and communication, psychosocial support services and referrals for treatment of HIV, tuberculosis and sexually transmitted diseases. Cooperation between health and public security officials has improved through regular meetings and dialogue. However, institutional capacity building is still needed to deliver sustainable and standardized services that will ultimately improve retention rates. This article documents the steps China made in overcoming the many barriers to success of its methadone program. These lessons might be useful for other countries in the region that are scaling-up their methadone programs.

Design and Implementation of a China Comprehensive AIDS Response Programme (China CARES), 2003-08

International Journal of Epidemiology. Dec, 2010  |  Pubmed ID: 21113037

Prior to 2003, there was limited capacity for an HIV/AIDS response in China. In early 2003, China launched a 5-year China Comprehensive AIDS Response Programme (China CARES) to contain the spread of HIV infection and reduce its impact. This article describes the China CARES' practices and experiences.

Preparation of HIV-1 Env Protein and Establishment of Ultrasensitive Detection Method of HIV-1 Gp41 Antibody

Journal of Nanoscience and Nanotechnology. Oct, 2010  |  Pubmed ID: 21137771

Preparation of HIV-1 Env protein and development of ultrasensitive detection method of HIV-1 gp41 antibody are challengeable tasks for early diagnosis of patients with HIV virus. The env gene fragments were obtained from the plasmid with HIV-1 env by PCR, and were cloned into T vector, and then were sequenced. The linear env gene fragments were prepared by Rapid Translation System (RTS) Linear Template Kit, the Env proteins were obtained by RTS Kit, and were purified by magnetic bead method. The Env protein's bioactivity was identified by Western Blotting. The prepared Env proteins were labeled with CdTe quantum dots (QDs), and the goat anti-HIV-1 gp41 IgG antibodies were detected by CdTe QDs-labeled Env proteins, the fluorescent signals were recorded by photoluminescent spectroscopy. Results show that the prepared Env proteins own bioactivity, the CdTe QDs-labeled Env proteins can combine with anti-HIV-1 gp41 IgG antibodies, and formed the Env-gp41-CdTe QDs complex, the fluorescent intensity of final products were negatively associated with the concentration of anti-HIV-1 gp41 IgG antibodies in sample, the limitation of detection is 100 pg/mL. In conclusion, HIV-1 Env proteins with bioactivity were successfully prepared by RTS, established CdTe QDs labeled Env proteins-based fluorescent immunoassay can successfully detect HIV-1 gp41 IgG antibodies, which has great potential in early diagnosis of HIV.

[Focusing Challenges and Priorities, to Improve the Against-HIV Practice Effectively]

Zhonghua Yu Fang Yi Xue Za Zhi [Chinese Journal of Preventive Medicine]. Nov, 2010  |  Pubmed ID: 21215119

Tuning the Resonance in High-temperature Superconducting Terahertz Metamaterials

Physical Review Letters. Dec, 2010  |  Pubmed ID: 21231556

In this Letter, we present resonance properties in terahertz metamaterials consisting of a split-ring resonator array made from high-temperature superconducting films. By varying the temperature, we observe efficient metamaterial resonance switching and frequency tuning. The results are well reproduced by numerical simulations of metamaterial resonance using the experimentally measured complex conductivity of the superconducting film. We develop a theoretical model that explains the tuning features, which takes into account the resistive resonance damping and additional split-ring inductance contributed from both the real and imaginary parts of the temperature-dependent complex conductivity. The theoretical model further predicts more efficient resonance tuning in metamaterials consisting of a thinner superconducting split-ring resonator array, which are also verified in subsequent experiments.

[Cloning and Recombinant Expression of Human Soluble TRAIL in Pichia Pastoris]

Sheng Wu Yi Xue Gong Cheng Xue Za Zhi = Journal of Biomedical Engineering = Shengwu Yixue Gongchengxue Zazhi. Dec, 2010  |  Pubmed ID: 21374984

TNF-related apoptosis-inducing ligand (TRAIL) is a member of factor TNF family, which could be potentially developed as novel antitumor agent due to its selective and efficient induction of apoptosis in tumor cells. Gene recombinant expression is an important tool for production of pharmaceutical protein. In this paper, the gene encoding human soluble TRAIL (114-281aa fragment) was cloned by PCR and then inserted into the Pichia Pastoris expression vector pPIC9K. The transformants were double-screened on plates containing neomycin G418 and many clones with high levels of G418-resistance were selected for further studies on protein expression. The recombinant human soluble TRAIL was secreted into the BMMY media under the condition of 3% methanol. And the recombinant protein was purified to homogeneity (-80% purity) by using Ni-agarose affinity chromatography. The yield of this protein is about 1-2 mg per liter culture. Cell viability assays demonstrated that human soluble TRAIL was cytotoxic in both leukemia cells Jurkat and lung cancer cells A549. After treatment with 0.05 microg/ml TRAIL, the survival rate of Jurkat cells was about 10%. The expressed TRAIL showed dose-dependent cytotoxicity in A549 cells within the range of 0.1-1 microg/ml. When the protein concentration reached 1 microg/ml, the survival rates of A549 cells were about 30%. However, the recombinant human soluble TRAIL did not show obvious cytotoxicity in human skin fibroblast cells (HSF) at concentrations tested. There results demonstrate that human soluble TRAIL is selectively cytotoxic in tumor cells. The expression system constructed in this experiment might contribute to further production of soluble TRAIL and TRAIL-based novel fusion proteins in large quantities.

A Novel Quantum Dots-based Point of Care Test for Syphilis

Nanoscale Research Letters. 2010  |  Pubmed ID: 20672123

One-step lateral flow test is recommended as the first line screening of syphilis for primary healthcare settings in developing countries. However, it generally shows low sensitivity. We describe here the development of a novel fluorescent POC (Point Of Care) test method to be used for screening for syphilis. The method was designed to combine the rapidness of lateral flow test and sensitiveness of fluorescent method. 50 syphilis-positive specimens and 50 healthy specimens conformed by Treponema pallidum particle agglutination (TPPA) were tested with Quantum Dot-labeled and colloidal gold-labeled lateral flow test strips, respectively. The results showed that both sensitivity and specificity of the quantum dots-based method reached up to 100% (95% confidence interval [CI], 91-100%), while those of the colloidal gold-based method were 82% (95% CI, 68-91%) and 100% (95% CI, 91-100%), respectively. In addition, the naked-eye detection limit of quantum dot-based method could achieve 2 ng/ml of anti-TP47 polyclonal antibodies purified by affinity chromatography with TP47 antigen, which was tenfold higher than that of colloidal gold-based method. In conclusion, the quantum dots were found to be suitable for labels of lateral flow test strip. Its ease of use, sensitiveness and low cost make it well-suited for population-based on-the-site syphilis screening.

Genome-wide Association Study Identifies 1p36.22 As a New Susceptibility Locus for Hepatocellular Carcinoma in Chronic Hepatitis B Virus Carriers

Nature Genetics. Sep, 2010  |  Pubmed ID: 20676096

To identify susceptibility variants for hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC), we conducted a genome-wide association study by genotyping 440,794 SNPs in 355 chronic HBV carriers with HCC and 360 chronic HBV carriers without HCC, all of Chinese ancestry. We identified one intronic SNP (rs17401966) in KIF1B on chromosome 1p36.22 that was highly associated with HBV-related HCC and confirmed this association in five additional independent samples, consisting of 1,962 individuals with HCC, 1,430 control subjects and 159 family trios. Across the six studies, the association with rs17401966 was highly statistically significant (joint odds ratio = 0.61, P = 1.7 x 10(-18)). In addition to KIF1B, the association region tagged two other plausible causative genes, UBE4B and PGD. Our findings provide evidence that the 1p36.22 locus confers susceptibility to HBV-related HCC, and suggest that KIF1B-, UBE4B- or PGD-related pathways might be involved in the pathogenesis of this malignancy.

Overexpression of P-selectin Glycoprotein Ligand-1 Enhances Adhesive Properties of Endothelial Progenitor Cells Through Syk Activation

Acta Biochimica Et Biophysica Sinica. Aug, 2010  |  Pubmed ID: 20705591

P-selectin glycoprotein ligand-1 (PSGL-1) not only functions as an anchor molecule to capture monocytes and other leukocytes to endothelial cells in ischemic tissue by its interaction with P-selectin, but also transduces signals to initiate firm adhesion. Endothelial progenitor cells are derived from monocytes and play a very important role in neovascularization. Transplantation of endothelial progenitor cells is a promising therapeutic strategy to improve treatment of ischemic disease such as myocardial and cerebral infarction; however, its efficacy is now limited by the fact that few of the transplanted cells adhere to and accumulate in the ischemic tissue. In this study we aimed to investigate whether the overexpression of PSGL-1 gene promotes endothelial progenitor cells adhesion activity and explore the underlying mechanisms. We found that after transfection with human PSGL-1 gene, endothelial progenitor cells exhibited higher affinity to activated human umbilical vein endothelial cells or recombined P-selectin/ICAM-1 monolayer. The overexpression of PSGL-1-enhanced beta2-integrin expression on endothelial progenitor cells surface, and this effect was Syk dependent. The specific Syk inhibitor abolished the elevating effect of overexpression of PSGL-1 on surface beta2-integrin expression and the adhesive affinity of endothelial progenitor cells. These results suggested that Syk plays a key role in signal transduction downstream of PSGL-1 in endothelial progenitor cells, and the overexpression of PSGL-1 improves endothelial progenitor cells adhesive properties through enhanced activation of Syk and following integrin activation.

Broadband Extraordinary Transmission in a Single Sub-wavelength Aperture

Optics Express. Aug, 2010  |  Pubmed ID: 20721084

Coordinate transformation is applied to design an all-dielectric device for Extraordinary Transmission (ET) in a single sub-wavelength slit. The proposed device has a broadband feature and can be applied from microwave to visible frequency bands. Finite-Difference Time-Domain (FDTD) simulations are used to verify the device's performance. The results show that significantly increased transmission is achieved through the sub-wavelength aperture from 4 GHz to 8 GHz when the device is applied. In contrast with previously reported systems, the frequency sensitivity of the new device is very low.

A Multifunctional Ribonuclease-A-conjugated CdTe Quantum Dot Cluster Nanosystem for Synchronous Cancer Imaging and Therapy

Small (Weinheim an Der Bergstrasse, Germany). Nov, 2010  |  Pubmed ID: 20927799

Nucleolar Localization Signals of LIM Kinase 2 Function As a Cell-penetrating Peptide

Protein and Peptide Letters. Dec, 2010  |  Pubmed ID: 20937035

LIM Kinase 2 (LIMK2) is a LIM domain-containing protein kinase which regulates actin polymerization thorough phosphorylation of the actin depolymerizing factor cofilin. It is also known to function as a shuttle between the cytoplasm and nucleus in endothelial cells. A basic amino acid-rich motif in LIMK2 was previously identified to be responsible for this shuttling function, as a nucleolar localization signal (NoLS). Here it is shown that this nucleolar localization signal sequence also has the characteristic function of a cell-penetrating peptide (CPP). We synthesized LIMK2 NoLS-conjugated peptides and a protein and analyzed their cell-penetrating abilities in various types of cells. The BC-box motif of the Von Hippel-Lindau (VHL) protein was used for the peptide. This motif previously has been reported to be involved in the neural differentiation of bone marrow stromal cells and skin-derived precursor cells. Green fluorescence protein (GFP) was used as a large biologically active biomolecule for the protein. The LIMK2 NoLS-conjugated peptides and protein translocated across the cell membranes of fibroblast cells, neural stem cells, and even iPS cells. These results suggest that LIMK2 NoLS acts as a cell-penetrating peptide and its cell-penetrating ability is not restricted by cell type. Moreover, from an in vivo assay using a mouse brain, it was confirmed that NoLS has potential for transporting biomolecules across the blood-brain barrier.

Neuronal Abelson Helper Integration Site-1 (Ahi1) Deficiency in Mice Alters TrkB Signaling with a Depressive Phenotype

Proceedings of the National Academy of Sciences of the United States of America. Nov, 2010  |  Pubmed ID: 20956301

Recent studies suggest that the human Abelson helper integration site-1 (AHI1) gene on chromosome 6 is associated with susceptibility to schizophrenia and autism, two common neuropsychological disorders with depression symptoms. Mouse Ahi1 protein is abundant in the hypothalamus and amygdala, which are important brain regions for controlling emotion. However, the neuronal function of Ahi1 remains unclear. With the Cre-loxP system, we created a mouse model that selectively reduces Ahi1 expression in neuronal cells. Mice with neuronal Ahi1 deficiency show reduced TrkB level in the brain and depressive phenotypes, which can be alleviated by antidepressant drugs or by overexpression of TrkB in the amygdala. Ahi1 deficiency promotes the degradation of endocytic TrkB and reduces TrkB signaling in neuronal cells. Our findings suggest that impaired endocytic sorting and increased degradation of TrkB can induce depression and that this impaired pathway may serve as a previously uncharacterized therapeutic target for depression.

Establishing ¹H Nuclear Magnetic Resonance Based Metabonomics Fingerprinting Profile for Spinal Cord Injury: a Pilot Study

Chinese Medical Journal. Sep, 2010  |  Pubmed ID: 21034541

Spinal cord injury (SCI) is a complex trauma that consists of multiple pathological mechanisms involving cytotoxic, oxidation stress and immune-endocrine. This study aimed to establish plasma metabonomics fingerprinting atlas for SCI using (1)H nuclear magnetic resonance (NMR) based metabonomics methodology and principal component analysis techniques.

Unique Role of Ionic Liquid in Microwave-assisted Synthesis of Monodisperse Magnetite Nanoparticles

Chemical Communications (Cambridge, England). Jun, 2010  |  Pubmed ID: 20449521

A small amount of ionic liquid [bmim][BF(4)] was found to be an efficient aid for microwave heating of nonpolar dibenzyl ether in high temperature solution-phase synthesis of monodisperse magnetite nanoparticles. It was found to act as both microwave absorber and assistant stabilizer in the reactive process and was recovered and reused in successive reactions.

Chondroitin Sulfate As a Molecular Portal That Preferentially Mediates the Apoptotic Killing of Tumor Cells by Penetratin-directed Mitochondria-disrupting Peptides

The Journal of Biological Chemistry. Aug, 2010  |  Pubmed ID: 20484051

The use of cell-penetrating peptides (CPPs) as drug carriers for targeted therapy is limited by the unrestricted cellular translocation of CPPs. The preferential induction of tumor cell death by penetratin (Antp)-directed peptides (PNC27 and PNC28), however, suggests that the CPP Antp may contribute to the preferential cytotoxicity of these peptides. Using PNC27 as a molecular model, we constructed three novel peptides (PT, PR9, and PD3) by replacing the leader peptide Antp with one of three distinct CPPs (TAT, R9, or DPV3), respectively. The IC(50) values of PNC27 in tumor cells were 2-3 times lower than in normal cells. However, all three engineered peptides demonstrated similar cytotoxic effects in tumor and normal cells. Another three chimeric peptides containing the leader peptide Antp with different mitochondria-disrupting peptides (KLA-Antp (KGA), B27-Antp (BA27), and B28-Antp (BA28)), preferentially induced apoptosis in tumor cells. The IC(50) values of these peptides (3-10 microM) were 3-6 times lower in tumor cells than in normal cells. In contrast, TAT-directed peptides (TAT-KLA (TK), TAT-B27 (TB27), and TAT-B28 (TB28)), were cytotoxic to both tumor and normal cells. These data demonstrate that the leader peptide Antp contributes to the preferential cytotoxicity of Antp-directed peptides. Furthermore, Antp-directed peptides bind chondroitin sulfate (CS), and the removal of endogenous CS reduces the cytotoxic effects of Antp-directed peptides in tumor cells. The overexpression of CS in tumor cells is positively correlated to the cell entry and cytotoxicity of Antp- directed peptides. These results suggest that CS overexpression in tumor cells is an important molecular portal that mediates the preferential cytotoxicity of Antp-directed peptides.

Long-term Primary Culture of Highly-pure Rat Embryonic Hippocampal Neurons of Low-density

Neurochemical Research. Sep, 2010  |  Pubmed ID: 20503070

In order to develop a simplified method for long-term primary culture of highly-pure rat embryonic hippocampal neurons of low-density (10(3) cells/cm(2)), we optimized and modified conventional culturing methods. The modifications of our simplified method include: (1) combinational application of two growth substrates, tail collagen and poly-L-lysine, to coat plastic culture dishes and coverslips for a better neuronal attachment; (2) dissociation of hippocampal tissues with combinational use of two milder enzymes (collagenase and dispase) and trypsin of a lower concentration to minimize enzymatic damages to cultured neurons; (3) a cell pre-plating step to preliminarily eliminate the contaminating non-neuronal cells; (4) a modified culture medium as a critical step to promote highly pure neurons of low-density for a long term; and (5) appropriately reduced frequency and volume of refreshment of the culture medium. Using our modified method, the beta-tubulin III-immunostained and Hoechst 33342 counterstained neurons harvested a steady and healthy growth with a longer culture time of over 35 days, and a clear distinction between TAU-1- and MAP2-immunoreactive neurites was apparent at the early culturing period. In addition, the purity of neurons was over 95% at the different time points in comparison with the control culture using conventional serum-free method in which most neurons degenerated and died within 5 days. Thus, our modified method proved to be a simple, feasible as well as time- and resource-saving approach for a long-term survival of pure rat embryonic hippocampal neurons of low-density.

Atmospheric Inorganic Nitrogen in Dry Deposition to a Typical Red Soil Agro-ecosystem in Southeastern China

Journal of Environmental Monitoring : JEM. Jun, 2010  |  Pubmed ID: 20532381

Atmospheric dry deposition is an important pathway of nitrogen (N) sources input to agro-ecosystems. With the knowledge of increasing agricultural effects by dry N deposition, researchers have paid great attention to this topic. Characteristics of dry N deposition were estimated by a big-leaf resistance analogy model and the Auto-Meteorological Experiment Station (AMES) in a typical red soil agro-ecosystem in southeastern China for two years (2005-2006). Monthly dry deposition velocities (V(d)) were in the range of 0.16-0.36, 0.07-0.17 and 0.07-0.24 cm s(-1) for NH(3), NO(2) and aerosol particles (aerosol NH(4)(+) or NO(3)(-)), respectively, and the V(d) were higher in spring and winter than in summer and autumn. Monthly dry N deposition concentration (C(a)) and inferred deposition flux (F(d)) were in the range of 63.38-261.10, 47.21-278.92, 1.56-7.15, 47.21-278.92 microg N m(-3) and of 1.31-8.60, 0.38-3.67, 0-0.08, 0.01-0.23 kg N ha(-2) for NH(3), NO(2), aerosol NH(4)(+) and aerosol NO(3)(-), respectively. During the study period (2005-2006), the total dry N deposition was 70.55 kg N ha(-1) yr(-1) which equivalent to 1.53.8 kg (urea) ha(-1) yr(-1) or 415.0 kg (ammonium bicarbonate) ha(-1) yr(-1) applied in the red soil agro-ecosystems. In addition, the annual mean N depositions, mean sum of the monthly N depositions were 69.44, 1.12, 53.95 and 16.60 kg N ha(-1) yr(-1) for gaseous N, aerosol N, ammonia N and oxidized N, making up 98.42%, 1.58%, 53.95% and 16.60% of the total dry deposition N (70.50 kg ha(-1) yr(-1)).

Nanoporous Thin Films with Controllable Nanopores Processed from Vertically Aligned Nanocomposites

Nanotechnology. Jul, 2010  |  Pubmed ID: 20585164

Porous thin films with ordered nanopores have been processed by thermal treatment on vertically aligned nanocomposites (VAN), e.g., (BiFeO(3))(0.5):(Sm(2)O(3))(0.5) VAN thin films. Uniformly distributed nanopores with an average diameter of 60 nm and 150 nm were formed at the bottom and top of the nanoporous films, respectively. Controllable porosity can be achieved by adjusting the microstructure of VAN (BiFeO(3)):(Sm(2)O(3)) thin films and the annealing parameters. In situ heating experiments within a transmission electron microscope (TEM) column at temperatures from 25 to 850 degrees C, provides significant insights into the phase transformation, evaporation and structure reconstruction during the annealing. The in situ experiments also demonstrate the possibility of processing vertically aligned nanopores (VANP) with one phase stable in a columnar structure. These nanoporous thin films with controllable pore size and density could be promising candidates for thin film membranes and catalysis for fuel cell and gas sensor applications.

Recyclable and Electrically Conducting Carbon Nanotube Composite Films

Nanoscale. Mar, 2010  |  Pubmed ID: 20644826

Carbon nanotube (CNT) composite films possess unique electrical, mechanical and thermal properties. In particular, some research has shown that CNT-polymer composite films greatly enhance the performance of organic light-emitting diodes. Therefore, CNT composite films have been intensively fabricated and applied. However, recent research has shown that CNTs carry carcinogenic risks in vivo. Therefore, how to collect and treat damaged or trashed CNT composite films are considerable tasks for scientists working in this area. From the viewpoint of environmental protection and saving resources, recycling the CNT composite films is the most efficient way to solve these problems. Here, we employ a benign water-soluble polymer, polyethyleneimine (PEI), to disperse CNTs and a general spin-coating process to prepare the homogeneous CNT composite films. The prepared CNT composite films exhibit good water-soluble properties and recyclability, i.e. they can be formed and dissolved in water. In addition, the long CNTs and high loading in the PEI matrix facilitates good electric conductivity in these CNT composite films. A significant improvement in the conductivity of the composite films is observed as the concentration of CNTs in the PEI increases, reaching as high as 43.73 S cm(-1) when the CNT concentration is equal to 3%.

[Research Advances of Techniques for Quantum Dots-based Tumor Marker Detection]

Sheng Wu Yi Xue Gong Cheng Xue Za Zhi = Journal of Biomedical Engineering = Shengwu Yixue Gongchengxue Zazhi. Jun, 2010  |  Pubmed ID: 20649049

Quantum dots, as a new kind of biological fluorescence material, have properties superior to the traditional organic dyes. In the recent decade, researches about the application of quantum dots in biomedicine have made great progress. Tumor markers have vital importance in the diagnosis and treatment of carcinoma; however, they are not widely used for lack of specificity and sensitivity. Researches about applications of quantum dots in the detection of tumor markers are centralized in three aspects, namely the detection of serum/plasma tumor markers, the detection of tissue and cell tumor markers (such as molecular imaging of cell and tissue), and the detection of tumor in vivo animals. A combination of quantum dots and flow cytometry technique for developing a new technique to detect multiple kinds of tumor markers at the same time with greater sensitivity, specificity, rapidity and convenience may have the potential for clinical use of quantum dots.

Periscope-like Endoscope for Transmission of a Near Field in the Infrared Range

Optics Letters. Jan, 2010  |  Pubmed ID: 20081948

A possibility to transmit near field through a periscope-like endoscope formed by an array of bent metallic rods is investigated. This is a first step on the way to development of flexible near-field endoscopes. An effort to tunnel the near field of a crown-shaped object through the periscope with 45 degrees bending angle is made, and a shift in the operating frequency band with respect to that of the straight endoscope is observed. An analysis of transmission coefficient as a function of transverse wave vector has been provided for a better understanding of the device operation. A distinctive nature of surface waves appearing at both interfaces has also been reported.

Selective Apoptotic Killing of Solid and Hematologic Tumor Cells by Bombesin-targeted Delivery of Mitochondria-disrupting Peptides

Molecular Pharmaceutics. Apr, 2010  |  Pubmed ID: 20141196

Tumor-homing peptides are attractive tools for tumor imaging and targeted therapy due to their ability to specifically bind and enter tumor cells and masses. Bombesin and its analogues show promise for the targeted delivery of radioactive and chemotherapeutic agents to a wide variety of solid tumors. Here, we describe the bombesin-targeted delivery of toxic peptides to solid tumor cells and leukemia cells. We found that bombesin specifically bound to solid tumor cells and leukemia cells with similar affinity. Conjugation to bombesin significantly (5-15 times) enhanced the cytotoxicity of three mitochondria-disrupting peptides (KLA, B27, and B28) in solid tumor cells and leukemia cells through improvement of their binding affinity. The bombesin-directed peptides (KB, BB27, and BB28) contained the same bombesin leader sequence but had different mitochondria-disrupting peptides, which selectively induced caspase-dependent apoptosis in solid tumor cells and leukemia cell lines. The IC50 values of these peptides (BB27, 3-5 micromol/L; BB28, 4-6 micromol/L) for solid tumor cells and leukemia cells are approximately 5-10 times lower than the IC50 values for normal cells. BB27 and BB28 also displayed cytotoxicity in primary leukemia cells from patients (n = 4) with acute myeloid leukemia. Intratumoral (10 mg/kg) and intraperitoneal (20 mg/kg) injection of BB27 and BB28 exerted substantial inhibition on K562 tumor xenograft growth without obvious systematic toxicity. Our results suggest that the bombesin-directed mitochondria-disrupting peptides BB27 and BB28 might be used as therapeutic agents not only for solid tumors but also for hematologic tumors.

[Recombinant Expression, Purification and Characterization of Colicin S4]

Sheng Wu Yi Xue Gong Cheng Xue Za Zhi = Journal of Biomedical Engineering = Shengwu Yixue Gongchengxue Zazhi. Feb, 2010  |  Pubmed ID: 20337042

Broad-spectrum of conventional antibiotics is one of the key factors that cause antibiotics-resistance of many bacteria. Bacteriocins are regarded as the next generation of antibiotics on account of their narrow-spectrum bactericidal activities. Many attentions have been paid to colicins because they are believed to be safe in regard to human body. In this paper, the genes encoding colicin S4 and its immunity protein were cloned into pQE30 to produce colicin S4 expression vector pQE30-Col S4. Colicin S4 was highly expressed as soluble form in gE colig M15 containing pQE30-Col S4. The yields ranged from 30 mg/L to 50 mg/L. The recombinant colicin S4 with an additional 6 His-tag at its N-terminus was found being similar to the natural colicin S4 in antibacterial activity. It only showed bactericidal activity against E. coli strains, thus makig it attractive to develop this protein as a novel antibiotic with narrow spectrum.

Death of Axotomized Retinal Ganglion Cells Delayed After Intraoptic Nerve Transplantation of Olfactory Ensheathing Cells in Adult Rats

Cell Transplantation. 2010  |  Pubmed ID: 20350358

Intraorbital transection of the optic nerve (ON) always induces ultimate apoptosis of retinal ganglion cells (RGCs) and consequently irreversible defects of vision function. It was demonstrated that transplanted olfactory ensheathing cells (OECs) in partially injured spinal cord have a distant in vivo neuroprotective effect on descending cortical and brain stem neurons. However, this study gave no answers to the question whether OECs can protect the central sensitive neurons with a closer axonal injury because different neurons respond variously to similar axonal injury and the distance between the neuronal soma and axonal injury site has a definite effect on the severity of neuronal response and apoptosis. In the present study, we investigated the effect of transplanted OECs on RGCs after intraorbital ON transection in adult rats. Green fluorescent protein (GFP)-OECs were injected into the ocular stumps of transected ON and a significantly higher number of surviving RGCs was found together with a consistent marked increase in the mRNA and protein levels of BDNF in the ON stump and retina in the OEC-treated group at 7 days, but not 2 and 14 days, time point when compared to the control group. Our findings suggest that OEC transplantation induces the expression of BDNF in the ocular ON stump and retina and delays the death of axotomized RGCs at a certain survival period.

Dispersive Cylindrical Cloaks Under Nonmonochromatic Illumination

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics. Jan, 2010  |  Pubmed ID: 20365495

Transformation-based cylindrical cloaks and concentrators are illuminated with nonmonochromatic waves and unusual effects are observed with interesting potential applications. The transient responses of the devices are studied numerically with the finite-difference time-domain method and the results are verified with analytical formulas. We compute the effective bandwidth of several cloaking schemes as well as the effect of losses on the performance of the structures. We also find that narrowband behavior, frequency shift effects, time delays, and spatial disturbances of the incoming waves are dominant due to the inherently dispersive nature of the devices. These effects are important and should be taken into account when designing metamaterial-based devices.

Prices, Availability and Affordability of Essential Medicines in Rural Areas of Hubei Province, China

Health Policy and Planning. May, 2010  |  Pubmed ID: 19955093

To investigate the availability of essential medicines and their prices in Hubei province.

Decreased Neural Stem/progenitor Cell Proliferation in Mice with Chronic/nonremitting Experimental Autoimmune Encephalomyelitis

Neuro-Signals. 2010  |  Pubmed ID: 19786810

It has been reported that autoimmune inflammatory processes in human multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE), may induce an alteration in neurogenesis. Studies with transgenic EAE mice have demonstrated an enhancement of neurogenesis in the subventricular zone (SVZ). In contrast, a reduction of stem cell proliferation in the same region has been observed by Pluchino et al. [Brain 2008;131:2564-2578] in myelin oligodendrocyte glycoprotein (MOG)-induced EAE mice. We immunized female C57BL/6 mice with MOG 35-55 peptide and successfully developed chronic/nonremitting EAE, which is believed to be analogous to the progressive form of MS. On day 21 postimmunization, coronal brain sections were collected and stained with anti-5-bromo-2'-deoxyuridine (BrdU) antibody. By counting the number of BrdU-labeled cells, we demonstrated that the neural stem/progenitor cell (NSC/NPC) proliferation decreased in the SVZ, which basically confirms the study of Pluchino et al. on the changes in the SVZ. A reduction of NSC/NPC proliferation also occurred in the hippocampal subgranular zone of the dentate gyrus. The hippocampus is well known to be an important region involved in learning and memory; thus, our finding may offer a possible explanation for the cognitive impairment in human chronic MS.

Evidence for Heterogeneity of Astrocyte De-differentiation in Vitro: Astrocytes Transform into Intermediate Precursor Cells Following Induction of ACM from Scratch-insulted Astrocytes

Cellular and Molecular Neurobiology. Apr, 2010  |  Pubmed ID: 19885729

Our previous study definitely demonstrated that the mature astrocytes could undergo a de-differentiation process and further transform into pluripotential neural stem cells (NSCs), which might well arise from the effect of diffusible factors released from scratch-insulted astrocytes. However, these neurospheres passaged from one neurosphere-derived from de-differentiated astrocytes possessed a completely distinct characteristic in the differentiation behavior, namely heterogeneity of differentiation. The heterogeneity in cell differentiation has become a crucial but elusive issue. In this study, we show that purified astrocytes could de-differentiate into intermediate precursor cells (IPCs) with addition of scratch-insulted astrocyte-conditioned medium (ACM) to the culture, which can express NG2 and A2B5, the IPCs markers. Apart from the number of NG2(+) and A2B5(+) cells, the percentage of proliferative cells as labeled with BrdU progressively increased with prolonged culture period ranging from 1 to 10 days. Meanwhile, the protein level of A2B5 in cells also increased significantly. These results revealed that not all astrocytes could de-differentiate fully into NSCs directly when induced by ACM, rather they generated intermediate or more restricted precursor cells that might undergo progressive de-differentiation to generate NSCs.

Pyridyl-substituted Corrole Isomers: Synthesis and Their Regulation to G-quadruplex Structures

Chemistry, an Asian Journal. Jan, 2010  |  Pubmed ID: 19937863

G-quadruplex DNA plays an important role in the potential therapeutic target for the design and development of anticancer drugs. As various G-quadruplex sequences in the promoter regions or telomeres can form different secondary structural modes and display a diversity of biology functions, variant G-quadruplex interactive agents may be necessary to cure different disease by differentiating variant types of G-quadruplexes. We synthesize five cationic methylpyridylium corroles and compare the interactions of corroles with different types of G-quadruplexes such as cmyc, htelo, and bcl2 by using surface plasmon resonance. Because of the importance of human telomere G-quadruplex DNA, we focus on the biological properties of the interactions between human telomere G-quadruplex DNA and corrole isomers using CD, T(m), PCR-stop (PCR= polymerase chain reaction), and polymerase-stop assay, which demonstrate the excellent ability of the corrole to induce and stabilize the G-quadruplex. This study provides the first experimental insight into how selectivity might be achieved for different G-quadruplexes by a single group of methylpyridylium corrole isomers that may be optimized for potential selective cancer therapy.

Thymosin-beta4 Attenuates Ethanol-induced Neurotoxicity in Cultured Cerebral Cortical Astrocytes by Inhibiting Apoptosis

Cellular and Molecular Neurobiology. Jan, 2010  |  Pubmed ID: 19688260

Thymosin-beta4 (Tbeta4) is a major actin monomer-binding peptide in mammalian tissues and plays a crucial role in the nervous system in synaptogenesis, neuronal survival and migration, axonal growth, and plastic changes of dendritic spines. However, it is unknown whether Tbeta4 is also involved in challenges with external stress such as ethanol-induced neurotoxicity. In the present study, we investigated the effects of Tbeta4 on ethanol-induced neurotoxicity in cultured cerebral cortical astrocytes and the underlying mechanisms. Primarily cultured astrocytes were treated with 1 microg/ml Tbeta4 2 h prior to administration of 100 mM ethanol for 0.5, 1, 3 and 6 days, respectively. The results showed that ethanol caused neurotoxicity in cultured astrocytes, as shown by declined cell viability, distinct astroglial apoptosis and increased intracellular peroxidation. Tbeta4 markedly promoted cell viability, ameliorated the injury of intracellular glial fibrillary acidic protein-immunopositive cytoskeletal structures, reduced the percentage of apoptotic astrocyte and cellular DNA fragmentation, suppressed caspase-3 activity and upregulated Bcl-2 expression, inhibited the accumulation of reactive oxygen species and production of malondialdehyde in ethanol-treated astrocytes in a time-dependent manner. These data indicated that Tbeta4 attenuates ethanol-induced neurotoxicity in cultured cortical astrocytes through inhibition of apoptosis signaling, and one of the mechanisms underlying the capacity of Tbeta4 to suppress apoptosis may in part be due to its effect of anti-peroxidation.

Design, Synthesis and Biological Activities of New Strobilurin Derivatives Containing Substituted Pyrazoles

Pest Management Science. Jan, 2010  |  Pubmed ID: 19760633

Strobilurins are one of the most important classes of agricultural fungicides. To discover new strobilurin analogues with high activity, a series of new strobilurin derivatives containing substituted pyrazoles in the side chain were synthesised and bioassayed.

Clinical Prognostic Significance of Heart Abnormality and Heart Rate Variability in Patients with Stroke

Neurological Research. Jun, 2010  |  Pubmed ID: 19473556

To investigate the difference of heart rate variability (HRV) and serum creatine kinase isoenzyme (CK-MB) activity between right-sided and left-sided stroke, and the relative impact of cardiac autonomic imbalance and heart abnormality on death by serum CK-MB activity and fractal dimension (FD) detection in patients with stroke.

The Potential of Magnetic Nanocluster and Dual-functional Protein-based Strategy for Noninvasive Detection of HBV Surface Antibodies

The Analyst. Feb, 2011  |  Pubmed ID: 21049106

Magnetic nanoclusters (MNCs) were synthesized in a one-pot process, carboxylic MNCs and dual-functional protein were prepared and used to capture hepatitis B virus surface antibodies (anti-HBs) in simulated diseased oral mucosal transudate (OMT) samples. The specific substrate of dual-functional protein, dual-labeled double-chained DNA molecules, based on Fluorescence Resonance Energy Transfer (FRET), was used to amplify the detection signal and the detection limit of 0.1 ng mL(-1) of anti-HBs monoclonal antibodies was achieved. Combination MNCs with dual-functional protein enables the noninvasive detection of hepatitis B virus (HBV) surface antibodies in OMT samples, showing promise as a diagnostic tool for the OMT diagnosis of infectious diseases with sensitive, specific and facile capabilities.

Synthesis and Self-assembly of 1-deoxyglucose Derivatives As Low Molecular Weight Organogelators

Beilstein Journal of Organic Chemistry. 2011  |  Pubmed ID: 21445371

Low molecular weight gelators are an important class of molecules. The supramolecular gels formed by carbohydrate derived low molecular weight gelators are interesting soft materials that show great potential for many applications. Previously, we have synthesized a series of methyl 4,6-O-benzylidene-α-D-glucopyranoside derivatives and found that several of them are good gelators for water, aqueous mixtures of DMSO, or aqueous mixtures of ethanol. The gelation efficiency of these glycolipid derivatives is dependent upon the structures of their acyl chains. In order to understand the influence of the anomeric position of the sugar headgroup towards self-assembly, we synthesized a series of 1-deoxyglucose analogs, and examined their gelation properties in several solvents. Several long chain esters, including diacetylene containing esters, and aryl esters exhibited gelation in ethanol, aqueous ethanol, or aqueous DMSO. The synthesis and characterization of these novel analogs are reported.

Short-term Continuous Subcutaneous Insulin Infusion Decreases the Plasma Vaspin Levels in Patients with Type 2 Diabetes Mellitus Concomitant with Improvement in Insulin Sensitivity

European Journal of Endocrinology / European Federation of Endocrine Societies. Jun, 2011  |  Pubmed ID: 21471167

To investigate the effects of short-term continuous subcutaneous insulin infusion (CSII) on plasma vaspin levels in patients with newly diagnosed type 2 diabetes mellitus (T2DM).

The Origin of Genetic Instability in CCTG Repeats

Nucleic Acids Research. Aug, 2011  |  Pubmed ID: 21478167

CCTG tetranucleotide repeat expansion is associated with a hereditary neurological disease called myotonic dystrophy type 2 (DM2). The underlying reasons that lead to genetic instability and thus repeat expansion during DNA replication remains elusive. Here, we have shown CCTG repeats have a high propensity to form metastable hairpin and dumbbell structures using high-resolution nuclear magnetic resonance (NMR) spectroscopy. When the repeat length is equal to three, a hairpin with a two-residue CT loop is formed. In addition to the hairpin, a dumbbell structure with two CT-loops is formed when the repeat length is equal to four. Nuclear Overhauser effect (NOE) and chemical shift data reveal both the hairpin and dumbbell structures contain a flexible stem comprising a C-bulge and a T·T mismatch. With the aid of single-site mutation samples, NMR results show these peculiar structures undergo dynamic conformational exchange. In addition to the intrinsic flexibility in the stem region of these structures, the exchange process also serves as an origin of genetic instability that leads to repeat expansion during DNA replication. The structural features provide important drug target information for developing therapeutics to inhibit the expansion process and thus the onset of DM2.

[Enhancement of Cytotoxicity of Cantionic Antimicrobial Peptide in Tumor Cells by Conjugation to Cell-penetrating Peptide]

Sheng Wu Yi Xue Gong Cheng Xue Za Zhi = Journal of Biomedical Engineering = Shengwu Yixue Gongchengxue Zazhi. Feb, 2011  |  Pubmed ID: 21485195

Due to their lower risk for induction of resistance, membrane-active antimicrobial peptides with anticancer effect are attractive in cancer therapy. Because cell binding contributes to the cytotoxicity of peptide, it is possible to enhance the cytotoxicity of antimicrobial peptide in tumor cells by conjugation to a cell-penetrating peptide (CPP). In this paper, a fusion peptide MPGA by conjugation of antimicrobial peptide MP to CPP Antp at its N-terminus was constructed. After compared the cytotoxicity of unconjugated MP with that of the fusion peptide, it was found that MPGA showed higher cytotoxicity than that of unconjugated MP. And the fusion peptide MPGA induced cell death in tumor cells by membrane disruption. These results demonstrated that the cytotoxicity of antimicrobial peptide can be significantly enhanced by conjugation to CPP, which might be an effective way to develop novel anticancer drugs.

A Digital Microfluidic Method for in Situ Formation of Porous Polymer Monoliths with Application to Solid-phase Extraction

Analytical Chemistry. May, 2011  |  Pubmed ID: 21524096

We introduce the marriage of two technologies: digital microfluidics (DMF), a technique in which droplets are manipulated by application of electrostatic forces on an array of electrodes coated by an insulator, and porous polymer monoliths (PPMs), a class of materials that is popular for use for solid-phase extraction and chromatography. In this work, circular PPM discs were formed in situ by dispensing and manipulating droplets of monomer solutions to designated spots on a DMF device followed by UV-initiated polymerization. We used PPM discs formed in this manner to develop a digital microfluidic solid-phase extraction (DMF-SPE) method, in which PPM discs are activated and equilibrated, samples are loaded, PPM discs are washed, and the samples are eluted, all using microliter droplets of samples and reagents. The new method has extraction efficiency (93%) comparable to that of pipet-based ZipTips and is compatible with preparative sample extraction and recovery for on-chip desalting, removal of surfactants, and preconcentration. We anticipate that DMF-SPE may be useful for a wide range of applications requiring preparative sample cleanup and concentration.

Variation in Carbon Isotope Discrimination in Cleistogenes Squarrosa (Trin.) Keng: Patterns and Drivers at Tiller, Local, Catchment, and Regional Scales

Journal of Experimental Botany. Aug, 2011  |  Pubmed ID: 21527626

Understanding the patterns and drivers of carbon isotope discrimination in C(4) species is critical for predicting the effects of global change on C(3)/C(4) ratio of plant community and consequently on ecosystem functioning and services. Cleistogenes squarrosa (Trin.) Keng is a dominant C(4) perennial bunchgrass of arid and semi-arid ecosystems across the Mongolian plateau of the Eurasian steppe. Its carbon isotope discrimination (((13))Δ) during photosynthesis is relatively large among C(4) species and it is variable. Here the ((13))Δ of C. squarrosa and its potential drivers at a nested set of scales were examined. Within cohorts of tillers, ((13))Δ of leaves increased from 5.1‰ to 8.1‰ from old to young leaves. At the local scale, ((13))Δ of mature leaves varied from 5.8‰ to 8.4‰, increasing with decreasing grazing intensity. At the catchment scale, ((13))Δ of mature leaves varied from 6.2‰ to 8.5‰ and increased with topsoil silt content. At the regional scale, ((13))Δ of mature leaves varied from 5.5‰ to 8.9‰, increasing with growing-season precipitation. At all scales, ((13))Δ decreased with increasing leaf nitrogen content (N(leaf)). N(leaf) was positively correlated with grazing intensity and leaf position along tillers, but negatively correlated with precipitation. The presence of the correlations across a range of different environmental contexts strongly implicates N(leaf) as a major driver of ((13))Δ in C. squarrosa and, possibly, other C(4) species.

Production and Characterization of LEA29Y, a Variant of Cytotoxic T-lymphocyte Antigen 4-immunoglobulin, in Pichia Pastoris

Applied Microbiology and Biotechnology. Aug, 2011  |  Pubmed ID: 21533579

Blocking the CD28/B7 costimulatory pathway is a promising strategy in the treatment of graft rejection, graft-versus-host disease and autoimmune diseases. LEA29Y, a high-affinity variant of cytotoxic T-lymphocyte antigen 4-immunoglobulin (CTLA4Ig), is a more potent inhibitor of the interaction between CD28 and B7 than is CTLA4Ig. In a previous study, LEA29Y was produced in a mammalian cell system, which is time-consuming and expensive. To obtain LEA29Y more efficiently and cost effectively, we attempted to produce LEA29Y using a Pichia pastoris expression system. The gene encoding LEA29Y, with an additional 6-His tag at the N-terminus, was cloned into the yeast vector pPIC9K and expressed in the P. pastoris strain GS115. Under the optimized induction conditions for protein expression (inoculum density, OD(600) = 80; methanol concentration added daily, 1.0-3.0%; induction time point, 72-96 h; culture medium pH = 6.0), the yield of purified LEA29Y was approximately 30 mg l(-1) by one-step Ni-agarose affinity chromatography. PNGase F treatment showed the purified LEA29Y to be post-translational modified by N-linked glycosylation. In biological function assays, LEA29Y expressed in P. pastoris demonstrated specific binding to B7-1/B7-2-positive Raji cells and also suppressed lymphocyte proliferation in a dose-dependent manner. These results suggest that LEA29Y produced in P. pastoris is biologically active and will be useful for experimental therapy on immunotherapy for transplant rejection and autoimmune diseases.

In-band Pumped Highly Efficient Ho:YAG Ceramic Laser with 21 W Output Power at 2097 Nm

Optics Letters. May, 2011  |  Pubmed ID: 21540932

We report on the high-power and high-efficiency operation of a polycrystalline Ho:YAG ceramic laser in-band pumped by a Tm fiber laser at ~1907 nm. Lasing characteristics of a 1.5 at.% and a 2.0 at.% Ho³⁺-doped YAG ceramic were investigated and compared. Using an output coupler of 6% transmission, over 21.4 W of cw output power at 2097 nm has been generated with the 1.5 at.% doped Ho:YAG ceramic under 35 W of incident pump power, corresponding to an average slope efficiency with respect to the incident pump power of 63.6% and an optical-to-optical conversion efficiency of 61.1%.

Role of Cellular Uptake in the Reversal of Multidrug Resistance by PEG-b-PLA Polymeric Micelles

Biomaterials. Aug, 2011  |  Pubmed ID: 21546083

Understanding the processes involved in the cellular uptake of nanoparticles is critical for developing effective nano drug delivery systems. In this paper we found that PEG-b-PLA polymeric micelles firstly interacted with cell membrane using atomic force microscopy (AFM) and then released their core-loaded agents into the cell membrane by fluorescence resonance energy transfer (FRET). The released agents were internalized into the cells via lipid raft/caveolae-mediated endocytosis using total internal reflection fluorescence microscopy (TIRFM) and endocytic inhibitors. Further studies revealed that paclitaxel (PTX)-loaded PEG-b-PLA micelles (M-PTX) increased the cellular accumulation of PTX in PTX-resistant human ovarian cell line A2780/T which resulted in more apoptosis as measured by flow cytometry and the cleavage of poly (ADP-ribose) polymerase (PARP) compared with free PTX. PEG-b-PLA micelles inhibited P-glycoprotein (Pgp) function and Pgp ATPase activity but had no effect on Pgp protein expression. The membrane microenvironment studies showed that PEG-b-PLA micelles induced cell membrane depolarization and enhanced membrane microviscosity. These results suggested that PEG-b-PLA micelles might inhibit Pgp function to reverse multidrug resistance (MDR) via interaction with cell membrane to affect the membrane microenvironment. This study provides a foundation for understanding the mechanism of reversing MDR by nanoparticles better and designing more effective nano drug carriers.

A Prototype of Giant Magnetoimpedance-based Biosensing System for Targeted Detection of Gastric Cancer Cells

Biosensors & Bioelectronics. Mar, 2011  |  Pubmed ID: 21239159

A targeted detection of gastric cancer cells is achieved by combining the giant magnetoimpedance (GMI)-based biosensing system and RGD-4C peptide coupled, chitosan covered superparamagnetic iron oxide particles (RGD-Fe(3)O(4)@chitosan). The micro-patterned GMI sensor for targeted detection is made of Co-based ribbon and fabricated by micro electromechanical system (MEMS) technology. Functionalized nanoparticles were designed by coating Fe(3)O(4) with chitosan and conjugating with RGD-4C peptides. The targeted cells were trickled down into the detection area of the system. The detection of each sample is carried out in ten-fold manner and average value is taken as the final result. This system can identify the differences between targeted cells and non-targeted cells. It is of considerable interest due to its potential application in the biomedical field of various specific detections.

Feasibility of Diagnosing Renal Allograft Dysfunction by Oligonucleotide Array: Gene Expression Profile Correlates with Histopathology

Transplant Immunology. Apr, 2011  |  Pubmed ID: 21130165

Effective non-invasive monitoring method to tell histopathology is a big challenge in renal transplantation.

Enhancement of Cytotoxicity of Antimicrobial Peptide Magainin II in Tumor Cells by Bombesin-targeted Delivery

Acta Pharmacologica Sinica. Jan, 2011  |  Pubmed ID: 21131998

To investigate whether the conjugation of magainin II (MG2), an antimicrobial peptides (AMPs), to the tumor-homing peptide bombesin could enhance its cytotoxicity in tumor cells.

Production of Bioactive, SUMO-modified, and Native-like TNF-α of the Rhesus Monkey, Macaca Mulatta, in Escherichia Coli

Applied Microbiology and Biotechnology. Dec, 2011  |  Pubmed ID: 22207214

Biotechnologically produced tumor necrosis factor alpha (TNF-α) neutralizing agents have proven efficient in patients suffering from disparate autoimmune diseases. The rhesus monkey (Macaca mulatta) could be developed as a model for human autoimmune disease. Consequently, a large amount of M. mulatta TNF-α (mmTNFα) is required to further understand TNF-α-related pathogenesis and evaluate novel human TNF-α (hTNFα) neutralizing agents. We therefore attempted to express mmTNFα by using a small ubiquitin-like modifier (SUMO) fusion system. The synthetic gene, encoding the fusion protein SUMO-mmTNFα, was inserted into a pQE30 plasmid and was transformed into Escherichia coli M15. The fusion protein was expressed as both soluble and insoluble protein in E. coli. Approximately 10-12 mg of SUMO-mmTNFα was obtained from the soluble fraction of 1 L of bacterial culture. Cleavage of the fusion protein with SUMO protease produced native-like mmTNFα. Both native-like and SUMO-modified mmTNFα formed functional trimers and showed excellent cytotoxicity (ED(50), 0.05-0.1 ng/ml) in standard L929 cells. In addition, SUMO-mmTNFα and mmTNFα also exhibited cytotoxicity in human cancer cell types, such as, breast, lung, and liver cancer cells. The hTNFα neutralizing agents, including soluble receptors of hTNFα and antibodies against hTNFα, interacted with the mmTNFα. These results demonstrate that the bioactive mmTNFα produced with the SUMO fusion system is useful for further research, especially for the in vitro preclinical evaluation of biological hTNFα neutralizing agents.

A Whole Body Statistical Shape Model for Radio Frequency Simulation

Conference Proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference. Aug, 2011  |  Pubmed ID: 22255985

The development of ultra low power wireless sensors for customized wearable and implantable medical devices requires patient specific models for radio frequency simulation to understand wave propagation in the body. In practice, the creation of a patient specific whole-body model is difficult and time consuming to create. It is therefore necessary to establish a method for studying a population in a statistical manner. In this paper, we present a statistical shape model for the whole body for RF simulation. It is built from 10 male and 10 female subjects of varying size and height. This model has the ability to instantiate a new surface mesh with the parameters allowed by the training set. This model would provide shapes of varying sizes for studies, without the requirement of obtaining subject specific whole body models. Results from finite-differences time-domain simulation are presented on the extreme shapes from the model and demonstrate the need for a full understanding of the range in body shapes.

Molecular Cloning, Expression and Characterization of the Functional Domain of CTLA4 from the Rhesus Monkey, Macaca Mulatta

Developmental and Comparative Immunology. Jul, 2011  |  Pubmed ID: 21349284

Cytotoxic T lymphocyte-associated antigen 4 (CTLA4) is a potent inhibitor of T cell activation. The genes encoding the membrane and soluble forms of Macaca mulatta CTLA4 (mmCTLA4) were isolated from peripheral blood mononuclear cells (PBMCs). The predicted mmCTLA4 protein is nearly identical to human CTLA4 (hCTLA4), with the exception of a serine instead of an asparagine residue at position 49 and a leucine instead of a methionine residue at position 141 of its extracellular domain. The fusion protein mmCTLA4Ig, containing the extracellular domain of mmCTLA4 and the constant region of the human IgG1 antibody, was expressed in Pichia pastoris. The mmCTLA4Ig produced by P. pastoris exhibited specific binding to human B7-positive Raji cells that could be inhibited by competitive binding of hCTLA4Ig. MmCTLA4Ig and hCTLA4Ig could comparably suppress the proliferation of lymphocytes derived from rhesus monkeys, humans, or mice that had been stimulated either by concanavalin A (Con A) or allogeneic cells. These results suggest that mmCTLA4 is a negative regulator of T cell activation and that mmCTLA4Ig may be useful for immunotherapy of immunologic diseases in the rhesus monkey.

Ghosting Phenomena in Single Photon Counting Imagers with Vernier Anode

The Review of Scientific Instruments. Feb, 2011  |  Pubmed ID: 21361576

We provide the ghosting theory of two-dimensional Vernier anode based imagers. The single photon counting detection system based on Vernier anode is constructed. The ghosting, which occurs during the decoding of two-dimensional Vernier anode, and its possible solutions are described in detail. On the basis of the discussion of the decoding algorithm, the ghosting theoretical model is established. Phase conditions on which imaging ghosting can be avoided and the probability distribution function are proposed; the root causes of ghosting of two-dimensional Vernier anode are also discussed.

Neutralization of BDNF Attenuates the in Vitro Protective Effects of Olfactory Ensheathing Cell-conditioned Medium on Scratch-insulted Retinal Ganglion Cells

Cellular and Molecular Neurobiology. Apr, 2011  |  Pubmed ID: 21082236

Transplantation of olfactory ensheathing cells (OECs) becomes one of the promising strategies in restoring lost functions of injured central nervous system. Elevated level of expressed brain-derived neurotrophic factor (BDNF) was revealed in the previous studies to be related to the protective effects of OECs on injured cortical and brain stem neurons as well as retinal ganglion cells (RGCs), but no evidence has been obtained to demonstrate whether transplanted OECs protect injured central neurons directly by their secreted BDNF. In the present study, the effects of BDNF neutralization on the neuroprotection of adult OEC-conditioned medium (OEC-CM) on scratch-insulted RGCs were examined. The results showed that OEC-CM protected cultured RGCs from scratch insult, and neutralization of BDNF by BDNF neutralizing antibody attenuated such neuroprotection of the medium. It is thus concluded that neurotrophic factors including BDNF secreted by OECs can protect injured OECs in vitro and BDNF plays a major role in such a protection of OECs.

The Protective Effects of Inosine Against Chemical Hypoxia on Cultured Rat Oligodendrocytes

Cellular and Molecular Neurobiology. Nov, 2011  |  Pubmed ID: 21643997

Inosine is a purine nucleoside and is considered protective to neural cells including neurons and astrocytes against hypoxic injury. However, whether oligodendrocytes (OLs) could also be protected from hypoxia by inosine is not known. Here we investigated the effects of inosine on primarily cultured rat OLs injured by rotenone-mediated chemical hypoxia, and the mechanisms of the effects using ATP assay, MTT assay, PI-Hoechst staining, TUNEL, and immunocytochemistry. Results showed that rotenone exposure for 24 h caused cell death and impaired viability in both immature and mature OLs, while pretreatment of 10 mM inosine 30 min before rotenone administration significantly reduced cell death and improved the viability of OLs. The same concentration of inosine given 120 min after rotenone exposure also improved viability of injured mature OLs. Immunocytochemistry for nitrotyrosine and cellular ATP content examination indicated that inosine may protect OLs by providing ATP and scavenging peroxynitrite for cells. In addition, immature OLs were more susceptible to hypoxia than mature OLs; and at the similar degree of injury, inosine protected immature and mature OLs differently. Quantitative real-time PCR revealed that expression of adenosine receptors was different between these two stages of OLs. These data suggest that inosine protect OLs from hypoxic injury as an antioxidant and ATP provider, and the protective effects of inosine on OLs vary with cell differentiation, possibly due to the adenosine receptors expression profile. As OLs form myelin in the central nervous system, inosine could be used as a promising drug to treat demyelination-involved disorders.

A Broadband Zone Plate Lens from Transformation Optics

Optics Express. Jun, 2011  |  Pubmed ID: 21716472

A zone plate lens utilizing a refractive instead of diffractive approach is presented for broadband operation. By utilizing transformation optics, we compress the conventional hyperbolic lens into a flat one with a few zone plates made of all-dielectric materials. Such a transformed lens maintains the broadband performance of the original lens, thus providing a superior alternative to the diffractive Fresnel element which is inherently narrow band.

[Application of Quantum Dots in Biomedical Detection]

Sheng Wu Yi Xue Gong Cheng Xue Za Zhi = Journal of Biomedical Engineering = Shengwu Yixue Gongchengxue Zazhi. Jun, 2011  |  Pubmed ID: 21774239

Semiconductor quantum dots (QDs) are a new kind of biological fluorescence material, which has many advantages, such as broad excitation spectra, tunable emission spectra and good photostability. In the field of biomedical detection, the problems encountered in the traditional organic dye-based biomedical detections, such as short fluorescence lifetime and failure to simultaneous excitation of multiple colors, can be solved by using QDs. Water-soluble QDs combined with specific bio-molecules can label targeting bio-compound, which is useful in bio-molecule detection, cell labeling, tissue imaging, and can be used in fluorescence resonance energy transfer (FRET) technology. Combining QDs and protein chip technology to develop a new technology to detect multiple kinds of tumor markers will be one of the promising clinical applications of QDs with greater sensitivity, specificity, rapidity and convenience.

[Serological Survey of Pandemic Influenza A (H1N1) Virus Infection Among Population in Hunan Province]

Zhonghua Shi Yan He Lin Chuang Bing Du Xue Za Zhi = Zhonghua Shiyan He Linchuang Bingduxue Zazhi = Chinese Journal of Experimental and Clinical Virology. Feb, 2011  |  Pubmed ID: 21789845

To understand the infection condition and analytical methods of Influenza A (H1N1) virus in the population of Hunan Province during different periods.

A Digital Microfluidic Method for Dried Blood Spot Analysis

Lab on a Chip. Oct, 2011  |  Pubmed ID: 21869989

Blood samples stored as dried blood spots (DBSs) are emerging as a useful sampling and storage vehicle for a wide range of applications. Unfortunately, the surging popularity of DBS samples has not yet been accompanied by an improvement in automated techniques for extraction and analysis. As a first step towards overcoming this challenge, we have developed a prototype microfluidic system for quantification of amino acids in dried blood spots, in which analytes are extracted, mixed with internal standards, derivatized, and reconstituted for analysis by (off-line and in-line) tandem mass spectrometry. The new method is fast, robust, precise, and most importantly, compatible with automation. We propose that the new method can potentially contribute to a new generation of analytical techniques for quantifying analytes in DBS samples for a wide range of applications.

ErbB2 Activation Contributes to De-differentiation of Astrocytes into Radial Glial Cells Following Induction of Scratch-insulted Astrocyte Conditioned Medium

Neurochemistry International. Dec, 2011  |  Pubmed ID: 21924310

Radial glial cells play a significant role in the repair of spinal cord injuries as they exert critical role in the neurogenesis and act as a scaffold for neuronal migration. Our previous study showed that mature astrocytes of spinal cord can undergo a de-differentiation process and further transform into pluripotential neural precursors; the occurrence of these complex events arise directly from the induction of diffusible factors released from scratch-insulted astrocytes. However, it is unclear whether astrocytes can also undergo rejuvenation to revert to a radial glial progenitor phenotype after the induction of scratch-insulted astrocytes conditioned medium (ACM). Furthermore, the mechanism of astrocyte de-differentiation to the progenitor cells is still unclear. Here we demonstrate that upon treating mature astrocytes with ACM for 10 days, the astrocytes exhibit progressive morphological and functional conversion to radial glial cells. These changes include the appearance of radial glial progenitor cells, changes in the immunophenotypical profiles, characterized by the co-expression of nestin, paired homeobox protein (Pax6) and RC2 as well as enhanced capability of multipotential differentiation. Concomitantly, ErbB2 protein level was progressively up-regulated. Thereby these results provide a potential mechanism by which ACM could induce mature astrocytes to regain the profile of radial glial progenitors due to activating the ErbB2 signaling pathways.

Atmospheric NO2 and NH3 Deposition into a Typical Agro-ecosystem in Southeast China

Journal of Environmental Monitoring : JEM. Nov, 2011  |  Pubmed ID: 21987178

The dry deposition of atmospheric nitrogen (including NO(2) and NH(3)) into a typical agro-ecosystem in Southeast China during 2006-2007 was estimated. Results indicated that the dry deposition velocities of NO(2) and NH(3) ranged from 0.04-0.24 cm s(-1) and 0.09-0.47 cm s(-1), respectively. The higher values appeared in the non-crop growing period. Concentrations of atmospheric NO(2) and NH(3) ranged from 24.64-104.10 μgN m(-3) and 14.40-389.6 μgN m(-3), respectively. Variation of the NH(3) mixing ratio showed a clear double-peak. NO(2) and NH(3) deposition fluxes were 74.68-80.75 kgN ha(-1), which was equivalent to 162.4 and 175.5 kg ha(-1) of urea applied in 2006-2007. The N deposition fluxes were 13.91-40.38 and 5.33-22.73 kgN ha(-1) in peanut and rice growing periods, accounting for 8.18%-40.38% and 2.13%-23.06% of N fertilizer usages, respectively. NO(2) and NH(3) deposition were significant for the red soil farmland.

Slim Luneburg Lens for Antenna Applications

Optics Express. Oct, 2011  |  Pubmed ID: 21997001

Luneburg lens is a marvellous optical lens but is extremely difficult to be applied in any practical antenna system due to its large spherical shape. In this paper, we propose a transformation that reduces the profile of the original Luneburg lens without affecting its unique properties. The new transformed slim lens is then discretized and simplified for a practical antenna application, where its properties were examined numerically. It is found that the transformed lens can be used to replace conventional antenna systems (i.e. Fabry-Perot resonant antennas) producing a high-directivity beam with low side-lobes. In addition, it provides excellent steering capabilities for wide angles, maintaining the directivity and side-lobes at high and low values respectively.

Extragastrointestinal Stromal Tumor in a Kidney Transplant Recipient

Clinical and Experimental Nephrology. Oct, 2011  |  Pubmed ID: 22009637

The occurrence of de novo malignant neoplasms has been shown in post-transplant recipients receiving immunosuppressive treatment. We present a case of a rare extragastrointestinal stromal tumor (EGIST) located in the pelvic cavity of a kidney transplant patient. A 57-year-old female patient was admitted to our department because of non-specific lower abdominal pain 6 months after renal transplantation. An abdominal computed tomography scan showed a 4.5 cm diameter pelvic tumor mass. The tumor was resected en bloc and confirmed as not being connected to the gastrointestinal wall. Microscopically, the tumor consisted of typical spindle cells with 2-3 mitotic figures per 50 high-power fields. Immunohistochemically, the tumor cells were strongly positive for CD117 (c-kit), and negative for CD34, SMA, s-100 protein, and desmin. Genetically, the tumor showed a silent mutation in exon 18 of the PDGFRA gene at codon 824 GTC > GTT (V824V) [rs2228230]. No recurrence was noted 24 months after the operation. This case draws our attention to the importance of considering EGISTs (including GISTs), even though they are extremely uncommon, in the differential diagnosis of mesenchymal neoplasms, especially in transplant patients.

Toward Sustainable and Comprehensive Control of Schistosomiasis in China: Lessons from Sichuan

PLoS Neglected Tropical Diseases. Oct, 2011  |  Pubmed ID: 22039563

Triggered by a fascinating publication in the New England Journal of Medicine detailing China's new multi-pronged strategy to control and eventually interrupt the transmission of Schistosoma japonicum, this PLoS Neglected Tropical Diseases Debate critically examines the generalizability and financial costs of the studies presented from the marshlands of the lake region. Edmund Seto from the University of California and colleagues emphasize that the epidemiology and control of schistosomiasis varies according to the social-ecological context. They conjecture that the successful intervention packages piloted in the lake region is not fully fit for the hilly and mountainous environments in Sichuan and Yunnan provinces, and hence call for more flexible, setting-specific, and less expensive control strategies. In response, Xiao-Nong Zhou from the National Institute of Parasitic Diseases at the Chinese Center of Disease Control and Prevention and colleagues explain the steps from designing pilot studies to the articulation and implementation of a new national control strategy through a careful process of scaling-up and adaptations. Finally, the two opponents converge. The need for integrated, intersectoral, and setting-specific control measures is stressed, supported by rigorous surveillance and continuous research. Experiences and lessons from China are important for shaping the schistosomiasis elimination agenda.

Genome-wide Functional Screening of MiR-23b As a Pleiotropic Modulator Suppressing Cancer Metastasis

Nature Communications. 2011  |  Pubmed ID: 22109528

miRNA globally deregulates human carcinoma. A critical open question is how many miRNAs functionally participate in cancer development, particularly in metastasis. We systematically evaluate the capability of all known human miRNAs to regulate certain metastasis-relevant cell behaviours. To perform the high-throughput screen of miRNAs, which regulate cell migration, we developed a novel self-assembled cell microarray. Here we show that over 20% of miRNAs have migratory regulation activity in diverse cell types, indicating a general involvement of miRNAs in migratory regulation. MiR-23b, which is downregulated in human colon cancer samples, potently mediates the multiple steps of metastasis, including tumour growth, invasion and angiogenesis in vivo. It regulates a cohort of prometastatic targets, including FZD7 or MAP3k1. These findings provide new insight into the physiological and potential therapeutic importance of miRNAs as a new class of functional modulators.

[Risk Factors of Death Cases of Hand-foot-and-mouth Disease in Hunan Province]

Zhonghua Yu Fang Yi Xue Za Zhi [Chinese Journal of Preventive Medicine]. Oct, 2011  |  Pubmed ID: 22321590

To study risk factors of death cases of hand foot and mouth diseases (HFMD) in Hunan province, so as to provide scientific evidence for further prevention and control.

Influence of Sand Layer Depth on Partial Nitritation As Pretreatment of Anaerobically Digested Swine Wastewater Prior to Anammox

Bioresource Technology. Jan, 2012  |  Pubmed ID: 22153598

This work aimed to investigate the influence of sand layer depth on partial nitritation performance as a preparative step for anaerobic ammonium oxidation (anammox) process in treating anaerobically digested effluent of swine wastewater. A lab-scale biological sand filter system was constructed and partial nitritation was successfully maintained with nitrogen loading rate (NLR) of approximately 50 g NH(4)(+)-N m(-3) d(-1). An average NH(4)(+)-N removal efficiency of 61.34% and conversion efficiency of NH(4)(+)-N to NO(2)(-)-N of 79.77% were achieved with a sand layer depth of 32 cm. An effluent with a NH(4)(+)-N concentration of 242.52 mg L(-1) and a NO(2)(-)-N concentration of 306.39 mg L(-1) was achieved when the sand layer depth was 32 cm, giving a NO(2)(-)-N/NH(4)(+)-N ratio close to 1.32, as required by anammox. Overall, using a biological sand filter system to treat anaerobically digested effluent of swine wastewater by partial nitritation pretreatment prior to anammox is feasible.

III-10, a Newly Synthesized Flavonoid, Induced Differentiation of Human U937 Leukemia Cells Via PKCδ Activation

European Journal of Pharmaceutical Sciences : Official Journal of the European Federation for Pharmaceutical Sciences. Jan, 2012  |  Pubmed ID: 22266210

Flavonoid is an important group of natural products which exerted anticancer effects against various cancers. III-10 is a newly synthesized flavonoid with a pyrrolidinyl and a benzyl group substitution. It shares a same carbon skeleton with flavonoid which indicates that it may also have potential anticancer activity. To investigate whether III-10 could express anticancer effect on human U937 leukemia cells through differentiation induction, a series of experiments were processed. MTT and trypan-blue excluding assays showed that III-10 possessed growth and viability inhibition effects on U937 cells. Giemsa staining was implemented to observe the morphologic changes of U937 cells after III-10 treatment. Nitroblue tetrazolium (NBT) reduction assay and cell surface antigen flow cytometry were carried out to figure out the way III-10 induced U937 cells to differentiate. These experiments revealed that III-10 could induce U937 cells to differentiate into monocyte-like cells. Western blots and immunofluorescence were performed to inspect the possible underlying mechanism. The results revealed that differentiation-related proteins phospholipids scramblase 1 (PLSCR1) and promyelocytic leukemia protein (PML) were up-regulated after III-10 treatment. And III-10 stimulated PLSCR1 and PML probably through activation of protein kinase Cδ (PKCδ). All these results suggested that III-10 was a prospective anticancer compound and was requisite to be proceeded further investigation.