In JoVE (3)

Other Publications (126)

Articles by Yan Gu in JoVE

Other articles by Yan Gu on PubMed

Chaotic Electronic Scattering with He(+)

Chaos (Woodbury, N.Y.). Oct, 1993  |  Pubmed ID: 12780062

We investigate classical electronic collisions with a He(+) ion. Scattering functions, such as the scattering angle, collisional time, or energy of the outgoing electron, all exhibit an interesting hierarchial self-similar structure, which can be interpreted in terms of the indefinite number of electronic returns to the vicinity of the nucleus, encounters between electrons, and Keplerian excursions of electrons during the collisional processes. Based on this mechanism a binary coding is introduced to organize the dynamics of this three-body system and to provide an understanding of the self-similarity among generations of scale magnification, which yields escape rates that vary with the sectional cut into the parameter space. The self-similarity displayed within a single generation, on the other hand, can be simply tied to the periods of the two independent electronic excursions. The physical interpretation and the symbolic dynamics introduced here are generally useful for three-body collisional systems, including atomic, molecular, or stellar collisions.

Antisense to Cyclin D1 Reverses the Transformed Phenotype of Human Gastric Cancer Cells

World Journal of Gastroenterology : WJG. Feb, 1999  |  Pubmed ID: 11819376

AIM:To further investigate the effect of cyclin D1 on the biologic behavior of cancer cells and its potential role in gene therapy of tumor.METHODS:A cyclin D1 subcloning plasmid termed BKSD1 was constructed by subcloning the human cyclin D1 cDNA into Bluescript-KS, a plasmid vector with a pair of T7 and T3 promoters, with recombinant DNA technology of molecular biology. So,it is easy to generate digoxigenin (DIG)-labeled RNA probes of antisense and sense to cyclin D1 using RKSD1 as a template vector. PDORD1AS, an eukaryotic expression vector containing the full-length human cyclin D1 cDNA in its antisense orientation cloned into the retroviral vector pDOR-neo, was successfully constructed with BKSD1 to change restriction sites. A gastric cancer cell line, SGC7901/VCR, was transfected with pDORD1AS by Lipofect Amine-mediated introduction and a subline termed SGC7901/VCRD1AS, which had stable overexpression of antisense RNA to cyclin D1, was obtained by selection in G418. The subline, control subline transfected pDOR-neo and SGC7901/VCR were evaluated by methods of immunohistochemistry, flow cytometry, molecular hybridization, morphology and cell biology.RESULTS:Compared with control cell lines, SGC7901/VCRD1AS had a reduced expression of cyclin D1 (inhibition rate was about 36%), increased cell size and cytoplasm to nucleus ratio, increased doubling time (42.2h to 26.8h and 26.4h), decreased saturation density (18.9X10(4) to 4.8X10(5) and 4.8X10(5)), increased percentage of cells in the G(1)/G(0) phase (80.9%-64.6% and 63.8%), reacquired serum dependence, and a loss of tumorigenicity in nude mice (0/4 to 4/4 and 4/4).CONCLUSION: Stable overexpression of antisense RNA to cyclin D1 can reverse the transformed phenotype of human gastric cancer cells and may provide an approach of gene therapy for gastric cancer.

Differential Inhibition of Hsc70 Activities by Two Hsc70-binding Peptides

Biochemistry. Mar, 2002  |  Pubmed ID: 11888292

The ability of two high-affinity Hsc70-binding peptides [FYQLALT (peptide-Phi) and NIVRKKK (peptide-K)] to differentially inhibit Hsc70-dependent processes in rabbit reticulocyte lysate (RRL) was examined. Both peptide-Phi and peptide-K inhibited chaperone-dependent renaturation of luciferase in RRL. Peptide-Phi, but not peptide-K, blocked Hsp90/Hsc70-dependent transformation of the heme-regulated eIF2 alpha kinase (HRI) into an active, heme-regulatable kinase. In contrast, peptide-K, but not peptide-Phi, inhibited Hsc70-mediated suppression of the activation of mature-transformed HRI. Furthermore, HDJ2 (Human DnaJ homologue 2), but not HDJ1, potentiated the ability of Hsc70 to suppress the activation of HRI in RRL. Mechanistically, peptide-K inhibited, while peptide-Phi enhanced, HDJ2-induced stimulation of Hsc70 ATPase activity in vitro. The data presented support the hypotheses that peptide-Phi acts to inhibit Hsc70 function by binding to the hydrophobic peptide-binding cleft of Hsc70, while peptide-K acts through binding to a site that modulates the interaction of Hsc70 with DnaJ homologues. Overall, the data indicate that peptide-Phi and peptide-K have differential effects on Hsc70 functions under quasi-physiological conditions in RRL, and suggest that therapeutically valuable peptide mimetics can be designed to inhibit specific functions of Hsc70.

The Anabolic Effects of Recombinant Human Growth Hormone and Glutamine on Parenterally Fed, Short Bowel Rats

World Journal of Gastroenterology : WJG. Aug, 2002  |  Pubmed ID: 12174391

To evaluate the metabolic effects associated with administration of rhGH and/or Gln in parenterally fed, short-bowel rats.

Improved Renal Transplantation in the Rat with a Nonsplinted Ureteroureterostomy

Microsurgery. 2002  |  Pubmed ID: 12210967

Orthotopic renal transplantation in the rat is a widely used model in immunology and transplantation-related research. Although numerous modifications of the surgical technique of ureteric reconstruction were evaluated, ureter complications following this reconstruction still occurred frequently. Instead of dividing the ureter in the middle between kidney and bladder (method 1), the anastomosis was performed close to the renal pelvis after cutting the ureter obliquely (method 2), which enlarged the diameter of the ureteral anastomosis 2-fold. The incidence of stenosis of ureteric anastomosis was 12.5% (3/24) using method 1, whereas this complication was avoided completely (0/45) using method 2. Furthermore, the risk of injury to the ureter was reduced, as isolation of the ureter was limited. These modifications improved the last delicate step in the procedure of rat kidney transplantation.

Substitution of Porcine Small Intestinal Submucosa for Rabbit Achilles Tendon, an Experimental Study

Zhonghua Yi Xue Za Zhi. Sep, 2002  |  Pubmed ID: 12425812

To study the effect of substitution of porcine small intestinal submucosa (SIS) for rabbit Achilles tendon.

The Characteristics of Pseudo Class III Malocclusion in Mixed Dentition

Zhonghua Kou Qiang Yi Xue Za Zhi = Zhonghua Kouqiang Yixue Zazhi = Chinese Journal of Stomatology. Sep, 2002  |  Pubmed ID: 12425855

To find the dentoskeletal characteristics of pseudo Class III malocclusion in mixed dentition.

Crystal Structure of an Inactive Akt2 Kinase Domain

Structure (London, England : 1993). Jan, 2003  |  Pubmed ID: 12517337

Akt/PKB represents a subfamily of three isoforms from the AGC serine/threonine kinase family. Amplification of Akt activity has been implicated in diseases that involve inappropriate cell survival, including a number of human malignancies. The structure of an inactive and unliganded Akt2 kinase domain reveals several features that distinguish it from other kinases. Most of the alpha helix C is disordered. The activation loop in this structure adopts a conformation that appears to sterically hinder the binding of both ATP and peptide substrate. In addition, an intramolecular disulfide bond is observed between two cysteines in the activation loop. Residues within the linker region between the N- and C-terminal lobes also contribute to the inactive conformation by partially occupying the ATP binding site.

Decidual Activin: Its Role in the Apoptotic Process and Its Regulation by Prolactin

Biology of Reproduction. May, 2003  |  Pubmed ID: 12606360

Successful pregnancy requires profound differentiation and reorganization of the uterine tissues including, as pregnancy progresses, extensive apoptosis of decidual tissue to accommodate the developing conceptus. We have previously shown a positive correlation between expression of activin A and apoptosis in the decidua and have also shown that expression of activin A occurs at the time when prolactin (PRL) receptors disappear from decidual cells. The goals of this study were to examine whether activin A plays a role in decidual apoptosis and whether expression of activin A in the decidua is regulated by PRL and placental lactogens. Studies were carried out using primary rat decidual cells, a decidual cell line (GG-AD), and PRL null mice. Treatment of decidual cells with activin A significantly increased DNA degradation, caspase 3 activity, and caspase 3 mRNA expression. However, this effect was observed only in the absence of endogenous activin production by these cells. Addition of follistatin to decidual cells that were producing activin A decreased both caspase 3 activity and mRNA expression. Similarly, addition of activin-blocking antibodies to cultures of GG-AD cells, which also produce activin A, caused a reduction in both DNA degradation and caspase 3 activity. PRL and placental lactogens caused an inhibition of activin A mRNA expression in primary decidual cells. Even more convincingly, decidua of PRL null mice expressed abundant activin A at a time when no expression of this hormone is detected in wild-type mice and treatment of PRL null mice with PRL caused a profound inhibition of activin A mRNA expression. In summary, our investigations into the role and regulation of decidual activin have revealed that activin A can induce cell death in the decidua and that its expression is under tight regulation by PRL and placental lactogens.

Beta-adrenergic Receptor Blockade Modulates Bcl-X(S) Expression and Reduces Apoptosis in Failing Myocardium

Journal of Molecular and Cellular Cardiology. May, 2003  |  Pubmed ID: 12738230

The mechanisms by which beta-adrenergic receptor (beta-AR) blockade modulates apoptosis in heart failure (HF) are unclear. We examined the impact of beta-AR blockade with metoprolol on myocardial remodeling, apoptosis, pro-apoptotic (Fas, Fas ligand, Bax, and Bcl-X(S)) and anti-apoptotic (Bcl-X(L)and Bcl-2) gene expression, and Bcl-X(L) and Bcl-X(S) protein in post-infarction HF in rats. In untreated rats, there was significant (P < 0.001) LV dilatation and systolic dysfunction compared to sham. Myocardial apoptosis was significantly increased (P < 0.005). Fas, Bax, and Bcl-2 mRNA expression was unchanged. However, Fas ligand mRNA and Bcl-X(S) mRNA and protein, all undetectable in sham, were markedly elevated (P < 0.001), whereas Bcl-X(L) mRNA and protein was unchanged. Immunohistochemistry confirmed increased Bcl-X(S) staining in failing myocardium, with unchanged Bcl-X(L). Metoprolol treatment resulted in: (1) improved LV remodeling (P < 0.025), (2) reduced myocardial apoptosis (P < 0.005), and (3) selective reduction in myocardial Bcl-X(S) expression (P < 0.001) without change in Fas, Fas ligand, Bax, Bcl-2, or Bcl-X(L). Studies in isolated rat myocytes revealed that prolonged isoproterenol (ISO) stimulation significantly increased Bcl-X(S) protein, reducing the Bcl-X(L)/X(S) ratio and myocyte survival (P < 0.005). ISO-induced Bcl-X(S) expression was significantly attenuated (P < 0.001) by both metoprolol and CGP20712A, a beta1-AR selective antagonist, but not by ICI118,551, a beta2-AR selective antagonist. We conclude that adrenergic activation, such as occurs in HF, increases pro-apoptotic Bcl-X(S) expression via the beta1-AR. beta-AR blockade in HF reduces myocardial apoptosis; attenuation of Bcl-X(S) expression may be one mechanism underlying this effect.

Preliminary Investigation of Nonsurgical Treatment of Severe Skeletal Class III Malocclusion in the Permanent Dentition

The Angle Orthodontist. Aug, 2003  |  Pubmed ID: 12940561

The purpose of the study was to analyze the effects of nonsurgical treatment on subjects with a severe skeletal Class III deformity and to directly evaluate dental and facial profile changes. Eighteen patients with severe skeletal Class III malocclusions (5 males, 13 females), diagnosed as indication for orthognathic surgery, were included in the study. The average age was 13.7 +/- 2.5 years. All the cases were treated with Tip-Edge straight-wire technique or Begg light wire technique. Lateral cephalometric films taken at the beginning and at the end of treatment were analyzed with the Pancherz analysis and traditional cephalometric analysis. The arithmetic mean and standard deviation were calculated for each variable and paired t-test was performed. A mean reduction of 6.5 mm in the overjet was noted (P < .001), with skeletal changes and dental changes contributing 20% and 80% to the overjet correction, respectively. The inclination of the upper incisors to the SN plane was increased 5.9 degrees (P < .01). The inclination of the lower incisors to the mandibular plane was decreased 6.6 degrees (P < .001). The difference between the distance of the upper lip and lower lip to Sn-Pg' at the beginning of treatment changed from a negative value to a positive value with a significant difference (P < .001). Successful treatment effects can be obtained with nonsurgical therapy in severe skeletal Class III malocclusions in the permanent dentition. A remarkable soft tissue change was noted after the treatment, and the concave facial profile changed to a straight profile (see two case reports).

Synergistic Effects of a Novel Nanoporous Stent Coating and Tacrolimus on Intima Proliferation in Rabbits

Catheterization and Cardiovascular Interventions : Official Journal of the Society for Cardiac Angiography & Interventions. Nov, 2003  |  Pubmed ID: 14571494

To overcome the problem of in-stent restenosis, the concept of local delivery of antiproliferative or immunosuppressive drugs has been introduced into interventional cardiology. Local drug delivery can be achieved by drug-eluting stents coated with polymer surfaces used for controlled drug release. However, several polymer coatings have shown an induction of inflammatory response and increased neointima formation. In the present study, the effect of a new inorganic ceramic nanoporous aluminum oxide (Al(2)O(3)) coating on neointima proliferation and its suitability as a carrier for the immunosuppressive drug tacrolimus have been investigated. 316 L stainless steel coronary stents were coated with a 500 nm thin nanoporous aluminum oxide layer. This ceramic nanolayer was used as a carrier for tacrolimus. Bare stents (n = 6), ceramic coated stents (n = 6), and ceramic coated stents loaded with 60 (n = 7) and 120 mug (n = 6) tacrolimus were implanted in the common carotid artery of New Zealand rabbits. The ceramic coating caused no significant reduction of neointimal thickness after 28 days. Loading the ceramic stents with tacrolimus led to a significant reduction of neointima thickness by 52% for 60 mug (P = 0.047) and 56% for 120 mug (P = 0.036) as compared to the bare stents. The ceramic coating alone as well as in combination with tacrolimus led to a reduced infiltration of lymphocytes and macrophages in the intima in response to stent implantation. Ceramic coating of coronary stents with a nanoporous layer of aluminum oxide in combination with tacrolimus resulted in a significant reduction in neointima formation and inflammatory response. The synergistic effects of the ceramic coating and tacrolimus suggest that this new approach may have a high potential to translate into clinical benefit.

[Inhibitory Effects of Antisense Focal Adhesion Kinase Oligodeoxynucleotides on the Invasion of Bel 7402 Hepatocellular Carcinoma Cells]

Zhonghua Gan Zang Bing Za Zhi = Zhonghua Ganzangbing Zazhi = Chinese Journal of Hepatology. Oct, 2003  |  Pubmed ID: 14572340

To study the inhibitory effects of antisense focal adhesion kinase (FAK) oligodeoxynucleotides (ODN) on the invasion of Bel 7402 cells, and investigate the mechanisms.

[Effect of Early Hemofiltration on Endotoxin and Cytokines Plasma Levels of Endotoxemic Pigs]

Zhonghua Er Ke Za Zhi. Chinese Journal of Pediatrics. Dec, 2003  |  Pubmed ID: 14723823

Cardiac Toxic Effects of Trans-2-hexenal Are Mediated by Induction of Cardiomyocyte Apoptotic Pathways

Cardiovascular Toxicology. 2003  |  Pubmed ID: 14734831

Aldehydes are ubiquitous pollutants with well-indicated but ill-defined cardiovascular toxicity. To investigate the direct toxic effects of environmental aldehyde exposure on the myocardium, 8-wk-old male ICR (Institute of Cancer Research) strain mice were gavage fed trans-2-hexenal (0.1, 1, 10, or 50 mg/kg/wk) or corn oil (vehicle) for 4 wk, during which cardiac function, myocardial morphology, cardiomyocyte apoptosis, and the cytochrome cmediated caspase activation apoptotic pathway were determined. Quantification by enzyme-linked immunosorbent assay (ELISA) revealed that aldehyde- protein adducts increase in mouse hearts following hexenal treatment, whereas echocardiographic analysis displayed a significant impairment of basal left-ventricular contractile function. Both histological analysis and TUNEL (terminal deoxynucleotidyl transferase-mediated nick-end labeling) staining indicated condensed nuclei and a significant increase in cardiomyocyte apoptosis in these mice, but immunohistochemistry-based confocal microscope revealed no marked myofibril disarray. Release of cytochrome c from mitochondria into the cytosol, concomitant with activation of caspase-3 and -9, was also found in hexenal-treated groups. In addition, isolated cardiac mitochondria formed hexenal-protein adducts when treated with hexenal, providing indirect evidence that the cardiac mitochondrion is one of primary subcellular targets of aldehyde toxins. These findings suggest that trans-2-hexenal exposure results in direct cardiac toxicity through, at least in part, induction of mitochondrial cytochrome c release-mediated apoptosis in cardiomyocytes, indicating that the cardiac mitochondrion is one of principal subcellular targets of aldehyde toxins.

Material Reaction to Suture Anchor

Arthroscopy : the Journal of Arthroscopic & Related Surgery : Official Publication of the Arthroscopy Association of North America and the International Arthroscopy Association. Mar, 2004  |  Pubmed ID: 15007322

The authors present a case of material reaction to suture anchor, which is rarely reported. Leukocyte rate, leukocyte differential, multiple cultures, and gram stain test could not prove infection. A second surgery for exploration of the shoulder joint was performed to reconstruct the rotator cuff without using anchors, and the rotator cuff tear healed after the second surgery. During the second surgery, the bone surrounding the anchors was found to be eroded and substituted with necrotic tissue. The anchors protruded outside the bone. The pathological examination of the necrotic tissue showed multinucleated giant cells of foreign body type, some of which had engulfed minute splinters of particulate foreign material. Either metal- or suture-induced bioreaction is suspected in this case.

Effect of 4-aminopyridine on Synaptic Transmission in Rat Hippocampal Slices

Brain Research. May, 2004  |  Pubmed ID: 15051526

Extracellular field excitatory postsynaptic potentials (fEPSPs) were recorded in area CA1 of rat hippocampal slices in vitro. The responses evoked by spontaneously released glutamate and GABA were recorded from area CA1 pyramidal neurons in rat hippocampal slices in whole-cell mode. The glutamate and GABA receptor-associated ligand-gated currents were obtained from dissociated single hippocampal pyramidal cells. The results showed that 4-aminopyridine (4-AP) had obvious effects on both presynaptic and postsynaptic events. Applications of 4-AP in micromolar concentration resulted in persistent enhancement of the initial slope of fEPSPs with the half-maximal enhancement concentration (EC(50)) of 46.7+/-2.68 microM. At the concentration of 200 microM, 4-AP increased the initial slopes of the total fEPSPs, NMDA- and AMPA-mediated fEPSPs components to 225.6+/-23.8%, 177.4+/-20.1% and 142.3+/-18.9%, respectively, but had no effect on the fiber volley. The half-maximal stimulus intensity to induce responses was reduced from 5.14+/-0.27 to 3.58+/-0.23 V. The frequencies of mEPSCs and mIPSCs were increased to 324.2+/-25.4% and 287.3+/-36.3% by 200 microM 4-AP. The amplitude histograms of mEPSCs and mIPSCs were fitted with Gaussian distributions. After 200 microM 4-AP application, the first and second peaks in Gaussian distributions of mEPSCs were shifted from 8.73+/-0.94 and 17.78+/-2.13pA to 10.48+/-0.82 and 21.14+/-2.45 pA, while those of mIPSCs were shifted from 13.65+/-0.96 and 25.51+/-2.95 pA to 11.21+/-1.04 and 23.08+/-2.37 pA. At 200 microM, 4-AP reduced paired-pulse facilitation and accelerated synaptic fatigue induced by stimulation at 10 Hz (for 1 s) and the ratio of fEPSPs(10)/fEPSPs(1) was decreased from 1.62+/-0.16 to 0.61+/-0.15. At 200 microM, 4-AP inhibited postsynaptic GABA currents induced by 5 microM GABA to 68.2+/-15.5%: by countering the effect of enhanced release of GABA from presynaptic terminals, this could depress the inhibitory pathway. Also at 200 microM, 4-AP increased NMDA currents to 155.3+/-17.8%, but had no significant effect on AMPA currents (94.2+/-15.6%). Our experimental results thus show that 4-AP-induced changes of synaptic transmission in area CA1 of rat hippocampus may be attributed to 4-AP's effects on both presynaptic terminals and postsynaptic receptors.

[Preliminary Study of Non-surgical Treatment of Severe Class III Malocclusion in 18 Patients of 12-20 Years Old]

Zhonghua Kou Qiang Yi Xue Za Zhi = Zhonghua Kouqiang Yixue Zazhi = Chinese Journal of Stomatology. Mar, 2004  |  Pubmed ID: 15061874

To analyze effects of non-surgical treatment on subjects of 12-20 years old with severe skeletal Class III deformity and to directly evaluate dental and facial profile changes.

Identification of the Region in Cdc42 That Confers the Binding Specificity to Activated Cdc42-associated Kinase

The Journal of Biological Chemistry. Jul, 2004  |  Pubmed ID: 15123659

The Rho family small G-protein Cdc42 has been implicated in a diversity of biological functions. Multiple downstream effectors have been identified. How Cdc42 discriminates the interaction with its multiple downstream effectors is not known. Activated Cdc42-associated tyrosine kinase (ACK) is a very specific effector of Cdc42. To delineate the Cdc42 signaling pathway mediated by ACK, we set about to identify the specific ACK-binding region in Cdc42. We utilized TC10, another member of the Rho family of G-proteins that is 66.7% identical to Cdc42, to construct TC10/Cdc42 chimeras for screening the specific ACK-binding region in Cdc42. A region between switch I and switch II has been identified as the specific ACK-binding (AB) region. The replacement of the AB region with the corresponding region in TC10 resulted in the complete loss of ACK-binding ability but did not affect the binding to WASP, suggesting that the AB region confers the binding specificity to ACK. On the other hand, replacement of the corresponding region of TC10 with the AB region enabled TC10 to acquire ACK-binding ability. Eight residues are different between the AB region and the corresponding region of TC10. The mutational analysis indicated that all eight residues contribute to the binding to ACK2. The assays for the Cdc42-mediated activation of ACK2 indicated that the AB region is essential for Cdc42 to activate ACK2 in cells. Thus, our studies have defined a specific ACK-binding region in Cdc42 and have provided a molecular basis for generating ACK binding-defective mutants of Cdc42 to delineate ACK-mediated signaling pathway.

[Detection of IFN-gamma Level in Single CD8+ T Cell]

Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi = Chinese Journal of Cellular and Molecular Immunology. Jan, 2005  |  Pubmed ID: 15629089

To establish a new method capillary electrophoretic immunoassay laser-induced fluorescence (CEIA-LIF), to detect IFN-gamma level in single CD8(+) T cell.

Connexin Interaction Patterns in Keratinocytes Revealed Morphologically and by FRET Analysis

Journal of Cell Science. Apr, 2005  |  Pubmed ID: 15769851

Multiple connexins, the major proteins of gap junctions, have overlapping expression in the human epidermis and are postulated to have a key role in keratinocyte differentiation and homeostasis. The functional importance of connexins in the epidermis is emphasised by the association of mutations in four human connexins with various hyperproliferative skin disorders. As immunohistochemistry demonstrated overlapping expression of specific connexins in keratinocytes, we performed colocalisation analyses and applied a modified FRET methodology to assess possible heteromeric interactions between different combinations of four wild-type (wt) and mutant connexins. The data generated indicate that there is evidence for multiple connexin interactions at the plasma membrane between (wt)Cx26, (wt)Cx30 and (wt)Cx31 in keratinocytes and thus, the potential for the formation of a large number of different channel types each with different channel properties. In addition, we demonstrate that the inherent in vitro trafficking defect of the skin disease mutations (D50N)Cx26 and (G11R)Cx30 can be overcome partially by the coexpression of different wild-type connexins but this rescue does not result in large gap junction aggregates at the plasma membrane. These data indicate that skin disease associated Cx26 or Cx30 mutations are likely to disrupt a number of different channel types important in distinct aspects of keratinocyte biology.

Serine Proteinase Over-expression in Relation to Deltamethrin Resistance in Culex Pipiens Pallens

Archives of Biochemistry and Biophysics. Jun, 2005  |  Pubmed ID: 15876421

Two serine proteinase genes were isolated from Culex pipiens pallens as significantly up-regulated genes in a deltamethrin-resistant strain through a combination of suppression substractive hybridization and gene expression profiling by macroarrays. These two genes were found to be expressed at least threefold higher in the resistant strain than in the susceptible one. By using rapid amplification of cDNA ends to screen the constructed cDNA library, we cloned these two sequences. There were 909 bp with an open reading frame of 786 bp in the sequence of trypsin cDNA (GenBank/NCBI AF468495), the deduced protein had 261 amino acids, which was most similar to the trypsin gene of Anopheles gambiae. There were 992 bp with an open reading frame of 816 bp in the chymotrypsin cDNA (GenBank/NCBI AY034060), and its deduced amino acid sequence had 271 amino acids, which was most similar to the chymotrypsin-like protein from Aedes aegypti. The two genes were stably expressed in mosquito C6/36 cells, and the expected 29 and 30 kDa bands were shown with Western blot, respectively. In these cells, after deltamethrin treatment, they had protective effects on the viability. The results indicate that trypsin and chymotrypsin were more highly expressed in the deltamethrin-resistant strain, and was related to insecticide resistance in mosquitoes, Cx. pipiens pallens.

Cloning and Overexpression of CYP6F1, a Cytochrome P450 Gene, from Deltamethrin-resistant Culex Pipiens Pallens

Acta Biochimica Et Biophysica Sinica. May, 2005  |  Pubmed ID: 15880260

CYP6F1 (GenBank/EMBL accession No. AY662654), a novel gene with a complete encoding sequence in the cytochrome P450 family 6, was cloned and sequenced from deltamethrin-resistant 4th instar larvae of Culex pipiens pallens. The cDNA sequence of CYP6F1 has an open reading frame of 1527 bp, which encodes a putative protein of 508 amino acid residues. The deduced amino acid sequence of CYP6F1 indicated that the encoded P450 has conserved domains of a putative membrane-anchoring signal, putative reductase-binding sites, a typical heme-binding site, an ETLR motif and substrate recognition sites. Semi-quantitative RT-PCR analysis indicated that the CYP6F1 gene was expressed to a greater extent in the deltamethrin-resistant strain than in the susceptible strain of Cx. pipiens pallens. The expression levels of the CYP6F1 gene in the deltamethrin-resistant 1st, 2nd, 3rd, 4th instar larvae and adult female mosquitoes differed, with highest expression levels in the 4th instar larvae. In addition, the CYP6F1 gene was stably expressed in mosquito C6/36 cells, and the expected 61.2 kDa band was identified by Western blotting. The cells transfected with CYP6F1 had an increased resistance to deltamethrin as compared with control cells. These results indicate that CYP6F1 is expressed at higher levels in the deltamethrin-resistant strain, and may confer some insecticide resistance in Cx. pipiens pallens.

Recurrent Acute Pancreatitis and Its Relative Factors

World Journal of Gastroenterology : WJG. May, 2005  |  Pubmed ID: 15902746

To evaluate the causes and the relative factors of recurrent acute pancreatitis.

Taurine-induced Modulation of Voltage-sensitive Na+ Channels in Rat Dorsal Root Ganglion Neurons

Brain Research Bulletin. Aug, 2005  |  Pubmed ID: 16023923

The physiological role of taurine, an abundant free amino acid in the neural system, is still poorly understood. The aim of this study was to investigate its effect on TTX-sensitive (TTX-S) and TTX-resistant (TTX-R) Na+ currents in enzymatically dissociated neurons from rat dorsal root ganglion (DRG) with conventional whole-cell recording manner under voltage-clamp conditions. A TTX-S Na+ current was recorded preferentially from large DRG neurons and a TTX-R Na+ current preferentially from small ones. For TTX-S Na+ channel, taurine of the concentration > or = 10 mM shifted the activation curve in the depolarizing direction and the inactivation curve in the hyperpolarizing direction. There was no change in the activation curve for TTX-R Na+ channel and the inactivation curve was shifted in the hyperpolarizing direction slightly in the presence of taurine > or = 20 mM. When the recovery kinetics was examined, the presence of taurine resulted in a slower recovery from inactivation of TTX-S currents and no change of TTX-R ones. All the effects of taurine were weakly concentration-dependent and partly recovered quite slowly after washout. Our data indicate that taurine alters the properties of Na+ currents in intact DRG neurons. These may contribute to the understanding of taurine as a natural neuroprotectant and the potential of taurine as a useful medicine for the treatment of sensory neuropathies.

Preliminary Investigation of Mitoxantrone Coating on Stent-grafts to Inhibit Neointimal Proliferation

Journal of Endovascular Therapy : an Official Journal of the International Society of Endovascular Specialists. Aug, 2005  |  Pubmed ID: 16048380

To investigate the inhibition of neointimal proliferation induced by a stent-graft loaded with mitoxantrone.

Effects of Copper on A-type Potassium Currents in Acutely Dissociated Rat Hippocampal CA1 Neurons

Neuroreport. Sep, 2005  |  Pubmed ID: 16148750

The effects of copper on voltage-gated A-type potassium currents were investigated in acutely dissociated rat hippocampal CA1 neurons using the whole-cell patch-clamp technique. Extracellular application of various concentrations of copper (1-1000 microM) reversibly reduced the amplitude of voltage-gated A-type potassium currents in a dose-dependent manner with a 50% inhibitory concentration value of 130 microM. Copper (300 microM) increased the V1/2 of the activation curve and state-inactivation curve by 17.2 and 9.0 mV, respectively. Thus, copper slowed down the activation and inactivation process of voltage-gated A-type potassium currents. This study indicated that copper reversibly inhibits the hippocampal CA1 neuronal voltage-gated A-type potassium current in a dose-dependent and voltage-dependent manner, and such actions are likely involved in the regulation of the neuronal excitability and the pathophysiology of Wilson's disease.

Anatomic Variations of the Hook of Hamate and the Relationship to Carpal Tunnel Syndrome

The Journal of Hand Surgery. Nov, 2005  |  Pubmed ID: 16344183

To determine the incidence of anatomic variations of the hook of hamate and to evaluate its association with the development of carpal tunnel syndrome (CTS).

Effects of Extracellular Delta-aminolaevulinic Acid on Sodium Currents in Acutely Isolated Rat Hippocampal CA1 Neurons

The European Journal of Neuroscience. Dec, 2005  |  Pubmed ID: 16367778

The effects of delta-aminolaevulinic acid (ALA) on voltage-gated sodium channel (VGSC) currents (I(Na)) in acutely isolated hippocampal CA1 neurons from 10- to 12-day-old Wistar rats were examined by using the whole-cell patch-clamp technique under voltage-clamp conditions. ALA from 0.01 microm to 20 microm was applied to the recorded neurons. Low concentrations of ALA (0.01-1.0 microM) increased I(Na) amplitude, whereas high concentrations of ALA (5.0-20.0 microM) decreased it. The average I(Na) amplitude reached a maximum of 117.4 +/- 3.9% (n = 9, P < 0.05) with 0.1 microM ALA, and decreased to 78.1 +/- 3.8% (n = 13, P < 0.05) with 10 microm ALA. ALA shifted the steady-state activation and inactivation curves of I(Na) in the hyperpolarizing direction with different V0.5, suggesting that ALA could depress the opening threshold of the voltage-gated sodium channel (VGSC) and thus increase the excitability of neurons through facilitating the opening of VGSC. The time course of recovery from inactivation was significantly prolonged at both low and high concentrations of ALA, whereas either low or high concentrations of ALA had no significant effect on the attenuation of I(Na) during stimulation at 5 Hz, indicating that the effect of ALA on VGSC is state-independent. Furthermore, we found that application of ascorbic acid, which blocks pro-oxidative effects in neurons, could prevent the increase of I(Na) amplitude at low concentrations of ALA. Baclofen, an agonist of GABAb receptors, induced some similar effects to ALA on VGSC, whereas bicuculline, an antagonist of GABAa receptors, could not prevent ALA-induced effects on VGSC. These results suggested that ALA regulated VGSC mainly through its pro-oxidative effects and GABAb receptor-mediated effects.

Genistein Inhibits Invasive Potential of Human Hepatocellular Carcinoma by Altering Cell Cycle, Apoptosis, and Angiogenesis

World Journal of Gastroenterology : WJG. Nov, 2005  |  Pubmed ID: 16425425

To study the in vitro and in vivo inhibitory effects of genistein on invasive potential of Bel 7402 hepatocellular carcinoma (HCC) cells and to explore the underlying mechanism.

Prediction of Treatment Outcome Following Correction of Anterior Crossbites in the Mixed Dentition: Orthodontic Versus Orthopaedic Methods

Australian Orthodontic Journal. May, 2005  |  Pubmed ID: 16433078

To separate subjects with anterior crossbite and mild maxillary deficiency into two groups: those that can be treated successfully with a 2 x 4 appliance and those that should be treated with reverse headgear and maxillary expansion.

Rat Decidual Cell Cultures

Methods in Molecular Medicine. 2006  |  Pubmed ID: 16251734

Pregnancy requires profound reorganization of the different tissues forming the uterus. Growth and differentiation of the uterine endometrial cells give rise to the decidual tissue, a transitory organ, which plays a key role in fetal survival. In this chapter, we describe a technique for the dispersion and the separation of the two different decidual cell subpopulations with high yield and viability. We also detail a cell culture method, which allows the maintenance of the function and life span of these highly purified decidual cells when cultured either separately or in a co-culture system.

Prolonged Oxidative Stress Inverts the Cardiac Force-frequency Relation: Role of Altered Calcium Handling and Myofilament Calcium Responsiveness

Journal of Molecular and Cellular Cardiology. Jan, 2006  |  Pubmed ID: 16288776

The normally positive force- and Ca2+ -frequency responses (FFR and CaFR) are inverted in heart failure (HF); whether oxidative stress contributes to these abnormalities is unknown. We evaluated the impact of acute and prolonged oxidative stress on contraction and Ca2+ handling in adult rat cardiomyocytes. Acute (30 min) exposure to H2O2 (100 microM) induced a twofold increase (P<0.025) in intracellular oxyradicals together with contractile depression despite preservation of the Ca2+ transient and the FFR and CaFR to 3 Hz, indicating reduced myofilament Ca2+ responsiveness. In contrast, prolonged (24 h) exposure to the copper-zinc superoxide dismutase inhibitor diethyldithiocarbamic acid (DDC, 1 microM) similarly augmented oxyradicals but also increased cell size, and contraction and Ca2+ transient duration (P<0.025). DDC-treated myocytes displayed inverted FFRs and attenuated (though still positive) CaFRs as compared to control, indicating reduced myofilament Ca2+ responsiveness coupled with altered Ca2+ handling. Protein levels of the Na+ -Ca2+ exchanger (NCX), sarcoplasmic reticular (SR) Ca2+ ATPase (SERCA2), and serine-16 phosphorylated phospholamban (pSer16-PLB) were increased (P<0.025), whereas dihydropyridine receptor abundance was decreased. Total PLB and ryanodine receptor protein expression were unchanged. Caffeine-induced Ca2+ release showed increased NCX activity (P<0.025) without changes in total releasable SR Ca2+, suggesting compensatory changes in SERCA2 and pSer16-PLB to maintain SR Ca2+ load. The superoxide scavenger Tiron attenuated these effects. Thus, acute oxyradical exposure rapidly depresses myofibrillar Ca2+ responsiveness. Prolonged oxidative stress further induces alterations in Ca2+ handling that combined with extant reductions in myofibrillar responsiveness invert the FFR. With regard to Ca2+ handling, reduced transsarcolemmal Ca2+ flux rather than reduced SR Ca2+ uptake was the primary determinant of a negative FFR. Analogous changes may be operative in HF, a state characterized by both oxidative stress and Ca2+ dysregulation.

The Number of Lymph Nodes with Metastasis Predicts Survival in Patients with Esophageal or Esophagogastric Junction Adenocarcinoma Who Receive Preoperative Chemoradiation

Cancer. Mar, 2006  |  Pubmed ID: 16456809

The survival of patients with locoregional adenocarcinoma of the esophagus or the esophagogastric junction (EGJ) who receive preoperative chemoradiation is reported to be better among patients who achieve a pathologic complete response than among patients who have residual tumor, including lymph node (LN) metastasis. However, the prognostic significance of the number of LNs with residual metastasis remains unclear.

[The Criminological Characteristics of Mental Retardation]

Fa Yi Xue Za Zhi. Feb, 2006  |  Pubmed ID: 16524190

To explore the criminological characteristics of mental retardation (MR) in forensic psychiatry.

Lower Second Molar Extraction in Correction of Severe Skeletal Class III Malocclusion

The Angle Orthodontist. Mar, 2006  |  Pubmed ID: 16539545

The purpose of this study was to evaluate dentoskeletal and soft-tissue profile changes after extraction of lower second molars and treatment using the Tip-Edge technique in severe Class III subjects. Thirteen patients with severe skeletal Class III malocclusion (four males, nine females), diagnosed as requiring orthognathic surgery, but who rejected surgical therapy, were included in the study. The average age was 13.2 +/- 0.8 years. Lateral cephalometric films taken at the beginning and the end of treatment were analyzed using the Pancherz analysis and a traditional cephalometric analysis. The arithmetic mean and standard deviation were calculated for each variable. Paired t-test was performed to evaluate significant treatment change. After active treatment, dramatic overjet change was noted, with an average value of 5.5 mm (P < .001). Inclination of lower incisors was decreased 12.0 degrees when measured to the mandibular plane (P < .001). Inclination of upper incisors was increased by 2.1 degrees to the SN plane (P > .05). A negative value of the distance between upper and lower lip position to Sn-Pg' at the beginning of treatment changed to a positive value (P < .001). The results of this preliminary study suggest that success in the treatment of some severe Class III deformity in the permanent dentition can be achieved with fixed appliances and extraction of lower second molars. A remarkable soft-tissue change was noted after the treatment, and concave facial profiles changed to straight profiles.

Postinfarct Cytokine Therapy Regenerates Cardiac Tissue and Improves Left Ventricular Function

Circulation Research. Apr, 2006  |  Pubmed ID: 16556872

We systematically investigated the comparative efficacy of three different cytokine regimens, administered after a reperfused myocardial infarction, in regenerating cardiac tissue and improving left ventricular (LV) function. Wild-type (WT) mice underwent a 30-minute coronary occlusion followed by reperfusion and received vehicle, granulocyte colony-stimulating factor (G-CSF)+Flt-3 ligand (FL), G-CSF+stem cell factor (SCF), or G-CSF alone starting 4 hours after reperfusion. In separate experiments, chimeric mice generated by reconstitution of radioablated WT mice with bone marrow from enhanced green fluorescent protein (EGFP) transgenic mice underwent identical protocols. Mice were euthanized 5 weeks later. Echocardiographically, LV function was improved in G-CSF+FL- and G-CSF+SCF-treated but not in G-CSF-treated mice, whereas LV end-diastolic dimensions were smaller in all three groups. Morphometrically, cytokine-treated hearts had smaller LV diameter and volume. Numerous EGFP-positive cardiomyocytes, capillaries, and arterioles were noted in the infarcted region in cytokine-treated chimeric mice treated with G-CSF+FL or G-CSF+SCF, but the numbers were much smaller in G-CSF-treated mice. G-CSF+FL therapy mobilized bone marrow-derived cells exhibiting increased expression of surface antigens (CD62L and CD11a) that facilitate homing. We conclude that postinfarct cytokine therapy with G-CSF+FL or G-CSF+SCF limits adverse LV remodeling and improves LV performance by promoting cardiac regeneration and probably also by exerting other beneficial actions unrelated to regeneration, and that G-CSF alone is less effective.

Pb2+ Impairs GABAergic Synaptic Transmission in Rat Hippocampal Slices: a Possible Involvement of Presynaptic Calcium Channels

Brain Research. May, 2006  |  Pubmed ID: 16630593

Pb2+ is a common pollutant that causes a wide variety of detrimental effects on developing central nervous system, including cognitive deficit. However, the mechanisms of Pb2+ neurotoxicity remain to be elucidated. GABAergic synaptic transmission in hippocampus is implicated in learning and memory. In the present study, we examined the effects of Pb2+ on GABA(A)-receptor-mediated inhibitory postsynaptic currents (IPSCs), recorded on CA1 pyramidal neurons in rat hippocampal slices, using whole-cell patch clamp recording. Pb2+ significantly inhibited the peak amplitude of evoked IPSCs and increased paired pulse ratio. In addition, Pb2+ (2-50 microM) significantly diminished the frequency of spontaneous IPSCs in a concentration-dependent manner with an IC(50) of 7.56 microM, without changing the amplitude of spontaneous IPSCs. However, Pb2+ (10 microM) did not alter the frequency and amplitude of miniature IPSCs. It was indicated that Pb2+ impaired GABAergic synaptic transmission via a presynaptic mechanism, inhibiting action potential-dependent GABA release. Interestingly, the inhibition of spontaneous IPSC frequency induced by 10 microM Pb2+ was significantly attenuated either in the presence of 100 muM Cd2+ or in a low-calcium (0.5 mM) bath. It suggested the involvement of voltage-gated calcium channels (VGCC) in Pb2+'s inhibition of GABA release. This study provided electrophysiological evidence from developing hippocampal slices to support that Pb2+ inhibited action potential-dependent GABA release by inhibiting presynaptic VGCC, which might be a mechanism for Pb2+ -induced cognitive deficit.

Inhibitory Effect of Cd2+ on Glycine-induced Chloride Current in Rat Hippocampal Neurons

Brain Research Bulletin. May, 2006  |  Pubmed ID: 16716838

The effects of cadmium (Cd(2+)) on glycine-induced Cl(-) current (I(Gly)) were investigated in acutely dissociated rat hippocampal CA1 neurons using the conventional whole-cell patch-clamp technique in this study. We found that Cd(2+) reversibly and concentration-dependently, reduced the amplitudes of I(Gly), with an IC(50) of 1.27 mM and Hill coefficient of 0.45. The depression of I(Gly) by Cd(2+) was independent of membrane voltage between -60 and +40 mV and did not involve a shift in the reversal potential of the current. A non-competitive inhibition was suggested by a double reciprocal plot of the effects of Cd(2+) on the concentration-response curve of the I(Gly). Since intracellular dialysis with 3mM Cd(2+) failed to modify I(Gly), it was suggested that the site of action of Cd(2+) is extracellular. The suppression of I(Gly) by Zn(2+) was unaffected by 3mM Cd(2+), which indicated that Zn(2+) and Cd(2+) bind to independent sites on glycine receptor. The results show that Cd(2+) decreases I(Gly) in acutely dissociated rat hippocampal neurons and the depression of I(Gly) by Cd(2+) may contribute to worsen the neurotoxicological impairment.

Influence of Stem Cell Mobilization and Liver Regeneration on Hepatic Parenchymal Chimerism in the Rat

Transplantation. Jun, 2006  |  Pubmed ID: 16794536

Despite the newly discovered plasticity of hematopoietic stem cells, their capacity to "transdifferentiate" into parenchymal cells and the regulation of this process is not yet elucidated. The present study was designed to investigate the effect of stem cell mobilization and liver regeneration on this process using a syngeneic rat female-to-male liver transplantation model.

Novel 2-aminopyrimidine Carbamates As Potent and Orally Active Inhibitors of Lck: Synthesis, SAR, and in Vivo Antiinflammatory Activity

Journal of Medicinal Chemistry. Aug, 2006  |  Pubmed ID: 16884310

The lymphocyte-specific kinase (Lck) is a cytoplasmic tyrosine kinase of the Src family expressed in T cells and NK cells. Genetic evidence in both mice and humans demonstrates that Lck kinase activity is critical for signaling mediated by the T cell receptor (TCR), which leads to normal T cell development and activation. A small molecule inhibitor of Lck is expected to be useful in the treatment of T cell-mediated autoimmune and inflammatory disorders and/or organ transplant rejection. In this paper, we describe the synthesis, structure-activity relationships, and pharmacological characterization of 2-aminopyrimidine carbamates, a new class of compounds with potent and selective inhibition of Lck. The most promising compound of this series, 2,6-dimethylphenyl 2-((3,5-bis(methyloxy)-4-((3-(4-methyl-1-piperazinyl)propyl)oxy)phenyl)amino)-4-pyrimidinyl(2,4-bis(methyloxy)phenyl)carbamate (43) exhibits good activity when evaluated in in vitro assays and in an in vivo model of T cell activation.

Administration of Granulocyte Colony Stimulating Factor After Liver Transplantation Leads to an Increased Incidence and Severity of Ischemic Biliary Lesions in the Rat Model

World Journal of Gastroenterology : WJG. Aug, 2006  |  Pubmed ID: 16937499

Recently it has been reported that granulocyte colony stimulating factor (G-CSF) can induce hypercoagulability in healthy bone marrow donors. It is conceivable that the induction of a prothrombotic state in a recipient of an organ graft with already impaired perfusion might cause further deterioration in the transplanted organ. This study evaluated whether G-CSF treatment worsens liver perfusion following liver transplantation in the rat model.

Determination of Conformational Free Energies of Peptides by Multidimensional Adaptive Umbrella Sampling

The Journal of Chemical Physics. Sep, 2006  |  Pubmed ID: 16965119

We improve the multidimensional adaptive umbrella sampling method for the computation of conformational free energies of biomolecules. The conformational transition between the alpha-helical and beta-hairpin conformational states of an alanine decapeptide is used as an example. Convergence properties of the weighted-histogram-analysis-based adaptive umbrella sampling can be improved by using multiple replicas in each adaptive iteration and by using adaptive updating of the bounds of the umbrella potential. Using positional root-mean-square deviations from structures of the alpha-helical and beta-hairpin reference states as reaction coordinates, we obtained well-converged free energy surfaces of both the in-vacuum and in-solution decapeptide systems. From the free energy surfaces well-converged relative free energies between the two conformational states can be derived. Advantages and disadvantages of different methods for obtaining conformational free energies as well as implications of our results in studying conformational transitions of proteins and in improving force field are discussed.

Discovery of Aminoquinazolines As Potent, Orally Bioavailable Inhibitors of Lck: Synthesis, SAR, and in Vivo Anti-inflammatory Activity

Journal of Medicinal Chemistry. Sep, 2006  |  Pubmed ID: 16970394

The lymphocyte-specific kinase (Lck) is a cytoplasmic tyrosine kinase of the Src family expressed in T cells and natural killer (NK) cells. Genetic evidence in both mice and humans demonstrates that Lck kinase activity is critical for signaling mediated by the T cell receptor (TCR), which leads to normal T cell development and activation. Selective inhibition of Lck is expected to offer a new therapy for the treatment of T-cell-mediated autoimmune and inflammatory disease. Screening of our kinase-preferred collection identified aminoquinazoline 1 as a potent, nonselective inhibitor of Lck and T cell proliferation. In this report, we describe the synthesis and structure-activity relationships of a series of novel aminoquinazolines possessing in vitro mechanism-based potency. Optimized, orally bioavailable compounds 32 and 47 exhibit anti-inflammatory activity (ED(50) of 22 and 11 mg/kg, respectively) in the anti-CD3-induced production of interleukin-2 (IL-2) in mice.

[Preliminary Investigation of Lower Second Molar Extraction in Correction of Severe Skeletal Class III Malocclusion]

Zhonghua Kou Qiang Yi Xue Za Zhi = Zhonghua Kouqiang Yixue Zazhi = Chinese Journal of Stomatology. Sep, 2006  |  Pubmed ID: 17129425

To evaluate dento-skeletal and soft-tissue profile changes after extraction of lower second molars and treatment using fixed appliances in severe class III subjects.

[Prophylactic Effect of Matrix Metalloproteinase Inhibitor on Acute Graft-versus-host Disease in a Murine Model]

Zhonghua Xue Ye Xue Za Zhi = Zhonghua Xueyexue Zazhi. Aug, 2006  |  Pubmed ID: 17172122

To explore the prophylactic effect of tissue inhibitor of matrix metalloproteinase (TIMP) on acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in a murine model.

[Early Identification of Non-surgical and Surgical Intervention of Class III Malocclusion]

Zhonghua Kou Qiang Yi Xue Za Zhi = Zhonghua Kouqiang Yixue Zazhi = Chinese Journal of Stomatology. Nov, 2006  |  Pubmed ID: 17331357

To establish a model of cephalometric variables for identification of indication of early treatment of class III malocclusion in mixed dentition.

Physiologic and Aberrant Regulation of Memory T-cell Trafficking by the Costimulatory Molecule CD28

Blood. Apr, 2007  |  Pubmed ID: 17119120

Productive T-cell immunity requires both the activation and the migration of specific T cells to the antigenic tissue. The costimulatory molecule CD28 plays an essential role in the initiation of T-cell-mediated immunity. We investigated the possibility that CD28 may also regulate migration of primed T cells to target tissue. In vitro, CD28-mediated signals enhanced T-cell transendothelial migration, integrin clustering, and integrin-mediated migration. In vivo, T cells bearing a mutation in the CD28 cytoplasmic domain, which abrogates PI3K activation, displayed normal clonal expansion but defective localization to antigenic sites following antigenic rechallenge. Importantly, antibody-mediated CD28 stimulation led to unregulated memory T-cell migration to extra-lymphoid tissue, which occurred independently of T-cell receptor (TCR)-derived signals and homing-receptor expression. Finally, we provide evidence that CD28- and CTLA-4-mediated signals exert opposite effects on T-cell trafficking in vivo. These findings highlight a novel physiologic function of CD28 that has crucial implications for the therapeutic manipulation of this and other costimulatory molecules.

Activated Cdc42-associated Kinase 1 is a Component of EGF Receptor Signaling Complex and Regulates EGF Receptor Degradation

Molecular Biology of the Cell. Mar, 2007  |  Pubmed ID: 17182860

Cdc42-associated tyrosine kinase 1 (ACK1) is a specific down-stream effector of Cdc42, a Rho family small G-protein. Previous studies have shown that ACK1 interacts with clathrin heavy chain and is involved in clathrin-coated vesicle endocytosis. Here we report that ACK1 interacted with epidermal growth factor receptor (EGFR) upon EGF stimulation via a region at carboxy terminus that is highly homologous to Gene-33/Mig-6/RALT. The interaction of ACK1 with EGFR was dependent on the kinase activity or tyrosine phosphorylation of EGFR. Immunofluorescent staining using anti-EGFR and GFP-ACK1 indicates that ACK1 was colocalized with EGFR on EEA-1 positive vesicles upon EGF stimulation. Suppression of the expression of ACK1 by ACK-RNAi inhibited ligand-induced degradation of EGFR upon EGF stimulation, suggesting that ACK1 plays an important role in regulation of EGFR degradation in cells. Furthermore, we identified ACK1 as an ubiquitin-binding protein. Through an ubiquitin-association (Uba) domain at the carboxy terminus, ACK1 binds to both poly- and mono-ubiquitin. Overexpression of the Uba domain-deletion mutant of ACK1 blocked the ligand-dependent degradation of EGFR, suggesting that ACK1 regulates EGFR degradation via its Uba domain. Taken together, our studies suggest that ACK1 senses signal of EGF and regulates ligand-induced degradation of EGFR.

Evolution of a Highly Selective and Potent 2-(pyridin-2-yl)-1,3,5-triazine Tie-2 Kinase Inhibitor

Journal of Medicinal Chemistry. Feb, 2007  |  Pubmed ID: 17253678

Inhibition of angiogenesis is a promising and clinically validated approach for limiting tumor growth and survival. The receptor tyrosine kinase Tie-2 is expressed almost exclusively in the vascular endothelium and is required for developmental angiogenesis and vessel maturation. However, the significance of Tie-2 signaling in tumor angiogenesis is not well understood. In order to evaluate the therapeutic utility of inhibiting Tie-2 signaling, we developed a series of potent and orally bioavailable small molecule Tie-2 kinase inhibitors with selectivity over other kinases, especially those that are believed to be important for tumor angiogenesis. Our earlier work provided pyridinyl pyrimidine 6 as a potent, nonselective Tie-2 inhibitor that was designed on the basis of X-ray cocrystal structures of KDR inhibitors 34 (triazine) and 35 (nicotinamide). Lead optimization resulted in pyridinyl triazine 63, which exhibited >30-fold selectivity over a panel of kinases, good oral exposure, and in vivo inhibition of Tie-2 phosphorylation.

Alkynylpyrimidine Amide Derivatives As Potent, Selective, and Orally Active Inhibitors of Tie-2 Kinase

Journal of Medicinal Chemistry. Feb, 2007  |  Pubmed ID: 17253679

The recognition that aberrant angiogenesis contributes to the pathology of inflammatory diseases, cancer, and myocardial ischemia has generated considerable interest in the molecular mechanisms that regulate blood vessel growth. The receptor tyrosine kinase Tie-2 is expressed primarily by vascular endothelial cells and is critical for embryonic vasculogenesis. Interference with the Tie-2 pathway by diverse blocking agents such as soluble Tie-2 receptors, anti-Tie-2 intrabodies, anti-Ang-2 antibodies, and peptide-Fc conjugates has been shown to suppress tumor growth in xenograft studies. An alternative strategy for interfering with the Tie-2 signaling pathway involves direct inhibition of the kinase functions of the Tie-2 receptor. Herein we describe the development of alkynylpyrimidine amide derivatives as potent, selective, and orally available ATP-competitive inhibitors of Tie-2 autophosphorylation.

Effects of Pb2+ on Muscarinic Modulation of Glutamatergic Synaptic Transmission in Rat Hippocampal CA1 Area

Neurotoxicology. May, 2007  |  Pubmed ID: 17267040

Lead (Pb(2+)) is a pollutant commonly found in the environment. It causes a wide variety of detrimental effects on developing central nervous system. However, the mechanisms of its neurotoxicity remained to be elucidated. In hippocampus, the muscarinic cholinergic system modulates certain forms of synaptic transmission and plasticity, and plays an important role in learning and memory. In this study, the effects of Pb(2+) on muscarinic modulation of glutamatergic synaptic transmission in hippocampal CA1 area were investigated using the conventional whole-cell patch-clamp technique in rat hippocampal slices. In the presence of nicotinic antagonist mecamylamine, carbachol (CCh), a cholinergic agonist, concentration-dependently inhibited glutamatergic excitatory postsynaptic currents (EPSCs), enhanced paired-pulse facilitation (PPF) and the response to 10-Hz pulse-trains. The analysis of the spontaneous excitatory postsynaptic currents (sEPSCs) showed the activation of muscarinic receptors by CCh decreased the frequency, amplitude and decay time of sEPSCs. The 10 microM Pb(2+) depressed the inhibition of EPSCs by CCh, reduced the CCh-induced enhancement of PPF and the response to 10-Hz pulse-trains, and also affected the modulation of sEPSCs by CCh. The results suggested that the activation of muscarinic acetylcholine (ACh) receptors in hippocampus could modulate glutamatergic synaptic transmission, while Pb(2+) exposure would lead to an alteration of muscarinic modulation, which might be involved in the Pb(2+)-induced impairment of synaptic transmission and plasticity during learning and memory.

Bradykinin-induced Blood-brain Tumor Barrier Permeability Increase is Mediated by Adenosine 5'-triphosphate-sensitive Potassium Channel

Brain Research. May, 2007  |  Pubmed ID: 17331483

Bradykinin has been shown to selectively transiently increase the permeability of the blood-brain barrier (BBB). This study was performed to determine whether ATP-sensitive potassium (K(ATP)) channels mediate the increase in permeability of brain tumor microvessels induced by BK. Using a rat brain glioma (C6) model, we found increased expression of K(ATP) channels at tumor sites via Western blot analysis, after intracarotid infusion of bradykinin at a dose of 10 microg/kg/min for 15 min. A significant increase (73.58%) of the integrated density value (IDV) of the K(ATP) channel Kir6.2 subunit was observed in rats with glioma after 10 min of bradykinin perfusion. The over-expression of K(ATP) channels with bradykinin was significantly attenuated by the K(ATP) channel antagonist glibenclamide. Immunohistochemistry and immunolocalization experiments showed that the over-expression of K(ATP) channels was more obvious near tumor capillaries of 10 microm in diameter. I(KATP) modulation by bradykinin in cultured C6 cells was also studied using the patch-clamp technique in a whole-cell configuration. Administration of bradykinin led to a significant opening of K(ATP) channels in a time-dependent manner. This led to the conclusion that the bradykinin-mediated BBB permeability increase is due to accelerated formation of K(ATP) channels, which are thus as an important target in the biochemical regulation of this process.

Synthesis, Structural Analysis, and SAR Studies of Triazine Derivatives As Potent, Selective Tie-2 Inhibitors

Bioorganic & Medicinal Chemistry Letters. May, 2007  |  Pubmed ID: 17350837

A novel class of selective Tie-2 inhibitors was derived from a multi-kinase inhibitor 1. By reversing the amide connectivity and incorporating aminotriazine or aminopyridine hinge-binding moieties, excellent Tie-2 potency and KDR selectivity could be achieved with 3-substituted terminal aryl rings. X-ray co-crystal structure analysis aided inhibitor design. This series was evaluated on the basis of potency, selectivity, and rat pharmacokinetic parameters.

Downregulation of CuZn-superoxide Dismutase Contributes to Beta-adrenergic Receptor-mediated Oxidative Stress in the Heart

Cardiovascular Research. Jun, 2007  |  Pubmed ID: 17362897

Sustained beta-adrenergic receptor (beta-AR) activation augments oxidative stress in the heart; whether alterations in antioxidant enzymes contribute to this effect is unknown.

IFN-alpha2 Induces Leukocyte Integrin Redistribution, Increased Adhesion, and Migration

Journal of Interferon & Cytokine Research : the Official Journal of the International Society for Interferon and Cytokine Research. Apr, 2007  |  Pubmed ID: 17477817

The human type I Interferon (IFN) family includes 14 closely related cytokines that are produced in response to viral and bacterial infections and mediate the progress of innate immune responses to adaptive immune protection, bind to a common receptor, and have qualitatively similar biologic activities. We have shown previously that IFN-alpha2 can induce human T cell chemotaxis, suggesting that type I IFNs may contribute to the development of an inflammatory environment. We here report that, in addition to promoting T cell chemotaxis, IFN-alpha2 enhances T cell adhesion to integrin ligands, which is associated with integrin clustering on the T cell surface and enhanced conjugate formation with dendritic cells. These effects were prevented by inhibition of mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K). As type I IFN receptor is ubiquitously expressed, this analysis was extended to other human leukocyte populations, including granulocytes and B cells. All leukocyte populations analyzed displayed increased chemotaxis, integrin clustering, and increased integrin-mediated adhesion following exposure to IFN-alpha2, revealing a broad-spectrum proinflammatory activity. These findings have obvious implications for the role of type I IFNs in the development of inflammatory responses leading to the initiation of adaptive immunity.

Design, Synthesis, and Evaluation of Orally Active Benzimidazoles and Benzoxazoles As Vascular Endothelial Growth Factor-2 Receptor Tyrosine Kinase Inhibitors

Journal of Medicinal Chemistry. Sep, 2007  |  Pubmed ID: 17696416

Inhibition of the VEGF signaling pathway has become a valuable approach in the treatment of cancers. Guided by X-ray crystallography and molecular modeling, a series of 2-aminobenzimidazoles and 2-aminobenzoxazoles were identified as potent inhibitors of VEGFR-2 (KDR) in both enzymatic and HUVEC cellular proliferation assays. In this report we describe the synthesis and structure-activity relationship of a series of 2-aminobenzimidazoles and benzoxazoles, culminating in the identification of benzoxazole 22 as a potent and selective VEGFR-2 inhibitor displaying a good pharmacokinetic profile. Compound 22 demonstrated efficacy in both the murine matrigel model for vascular permeability (79% inhibition observed at 100 mg/kg) and the rat corneal angiogenesis model (ED(50) = 16.3 mg/kg).

Mechanisms of Acrolein-induced Myocardial Dysfunction: Implications for Environmental and Endogenous Aldehyde Exposure

American Journal of Physiology. Heart and Circulatory Physiology. Dec, 2007  |  Pubmed ID: 17921335

Aldehydes are ubiquitous pollutants generated during the combustion of organic materials and are present in air, water, and food. Several aldehydes are also endogenous products of lipid peroxidation and by-products of drug metabolism. Despite well-documented high reactivity of unsaturated aldehydes, little is known regarding their cardiovascular effects and their role in cardiac pathology. Accordingly, we examined the myocardial effects of the model unsaturated aldehyde acrolein. In closed-chest mice, intravenous acrolein (0.5 mg/kg) induced rapid but reversible left ventricular dilatation and dysfunction. In mouse myocytes, micromolar acrolein acutely depressed myofilament Ca(2+) responsiveness without altering catecholamine sensitivity, similar to the phenotype of stunned myocardium. Immunoblotting revealed increased acrolein-protein adducts and protein-carbonyls in both acrolein-exposed myocardium (1.8-fold increase, P < 0.002) and myocytes (6.4-fold increase, P < 0.02). Both the contractile dysfunction and adduct formation were markedly attenuated by pretreatment with the thiol donor N-acetylcysteine (5 mM). Two-dimensional gel electrophoresis and mass-assisted laser desorption/ionization time-of-flight mass spectrometry analysis revealed two groups of adducted proteins, sarcomeric/cytoskeletal proteins (cardiac alpha-actin, desmin, myosin light polypeptide 3) and energy metabolism proteins (mitochondrial creatine kinase-2, ATP synthase), indicating site-specific protein modification that was confirmed by immunohistochemical colocalization. We conclude that direct exposure to acrolein induces selective myofilament impairment, which may be, in part, related to the modification of proteins involved in myocardial contraction and energy metabolism. Myocardial dysfunction induced by acrolein and related aldehydes may be symptomatic of toxicological states associated with ambient or occupational exposures or drug toxicity. Moreover, aldehydes such as acrolein may mediate cardiac dysfunction in pathologies characterized by high-oxidative stress.

Liver Transplantation for HELLP Syndrome

The American Surgeon. Oct, 2007  |  Pubmed ID: 17983071

Of the approximately one in 1000 pregnant women who develop the syndrome of hemolysis, elevated liver enzymes, and low platelets (HELLP), 2 to 3 per cent develop hepatic complications, including liver failure for which liver transplantation (LT) may be required. Between February 1, 1984, and December 31, 2006, eight women without a history of liver disease underwent LT for complications of HELLP syndrome. All received cadaveric grafts with a mean interval from delivery to LT of 7 days. The mean admission Child-Turcotte-Pugh score was 13.1 (class C), and the mean model for end-stage liver disease score was 40. Manifestations of liver failure included encephalopathy (seven patients), renal failure (four), disseminated intravascular coagulation (three), and respiratory failure (one). There were no intraoperative deaths. Complications of LT included biliary leaks (three patients), reoperation (three), and retransplantation (two). There was one death from sepsis on postoperative day 91 and one death from cholangitis/sepsis more than 5 years postoperatively. After LT, 1-, 5-, and 10-year patient survival rates were 88 per cent, 88 per cent, and 65 per cent; 1-, 5-, and 10-year graft survival rates were 64 per cent, 64 per cent, and 48 per cent. This is the largest single-center report of LT for HELLP. Early recognition and transfer to a transplant center will yield best results with this challenging complication of pregnancy.

Mandibular Growth Changes and Cervical Vertebral Maturation. a Cephalometric Implant Study

The Angle Orthodontist. Nov, 2007  |  Pubmed ID: 18004911

To evaluate mandibular dimensional changes and regional remodeling occurring during five intervals of circumpubertal growth.

C-Met Inhibitors with Novel Binding Mode Show Activity Against Several Hereditary Papillary Renal Cell Carcinoma-related Mutations

The Journal of Biological Chemistry. Feb, 2008  |  Pubmed ID: 18055465

c-Met is a receptor tyrosine kinase often deregulated in human cancers, thus making it an attractive drug target. One mechanism by which c-Met deregulation leads to cancer is through gain-of-function mutations. Therefore, small molecules capable of targeting these mutations could offer therapeutic benefits for affected patients. SU11274 was recently described and reported to inhibit the activity of the wild-type and some mutant forms of c-Met, whereas other mutants are resistant to inhibition. We identified a novel series of c-Met small molecule inhibitors that are active against multiple mutants previously identified in hereditary papillary renal cell carcinoma patients. AM7 is active against wild-type c-Met as well as several mutants, inhibits c-Met-mediated signaling in MKN-45 and U-87 MG cells, and inhibits tumor growth in these two models grown as xenografts. The crystal structures of AM7 and SU11274 bound to unphosphorylated c-Met have been determined. The AM7 structure reveals a novel binding mode compared with other published c-Met inhibitors and SU11274. The molecule binds the kinase linker and then extends into a new hydrophobic binding site. This binding site is created by a significant movement of the C-helix and so represents an inactive conformation of the c-Met kinase. Thus, our results demonstrate that it is possible to identify and design inhibitors that will likely be active against mutants found in different cancers.

Reconstruction of the Abdominal Wall by Using a Combination of the Human Acellular Dermal Matrix Implant and an Interpositional Omentum Flap After Extensive Tumor Resection in Patients with Abdominal Wall Neoplasm: a Preliminary Result

World Journal of Gastroenterology : WJG. Feb, 2008  |  Pubmed ID: 18205267

To present our trial using a combination of the human acellular dermal matrix (HADM) implant and an interpositional omentum flap to repair giant abdominal wall defects after extensive tumor resection.

Structure-based Design of Novel 2-amino-6-phenyl-pyrimido[5',4':5,6]pyrimido[1,2-a]benzimidazol-5(6H)-ones As Potent and Orally Active Inhibitors of Lymphocyte Specific Kinase (Lck): Synthesis, SAR, and in Vivo Anti-inflammatory Activity

Journal of Medicinal Chemistry. Mar, 2008  |  Pubmed ID: 18278858

Lck, or lymphocyte specific kinase, is a cytoplasmic tyrosine kinase of the Src family expressed in T-cells and NK cells. Genetic evidence from knockout mice and human mutations demonstrates that Lck kinase activity is critical for T-cell receptor-mediated signaling, leading to normal T-cell development and activation. A small molecule inhibitor of Lck is expected to be useful in the treatment of T-cell-mediated autoimmune and inflammatory disorders and/or organ transplant rejection. In this paper, we describe the structure-guided design, synthesis, structure-activity relationships, and pharmacological characterization of 2-amino-6-phenylpyrimido[5',4':5,6]pyrimido[1,2- a]benzimidazol-5(6 H)-ones, a new class of compounds that are potent inhibitors of Lck. The most promising compound of this series, 6-(2,6-dimethylphenyl)-2-((4-(4-methyl-1-piperazinyl)phenyl)amino)pyrimido[5',4':5,6]pyrimido-[1,2- a]benzimidazol-5(6 H)-one ( 25), exhibits potent inhibition of Lck kinase activity. This activity translates into inhibition of in vitro cell-based assays and in vivo models of T-cell activation and arthritis, respectively.

Structure-guided Design of Aminopyrimidine Amides As Potent, Selective Inhibitors of Lymphocyte Specific Kinase: Synthesis, Structure-activity Relationships, and Inhibition of in Vivo T Cell Activation

Journal of Medicinal Chemistry. Mar, 2008  |  Pubmed ID: 18321037

The lymphocyte-specific kinase (Lck), a member of the Src family of cytoplasmic tyrosine kinases, is expressed in T cells and natural killer (NK) cells. Genetic evidence, including knockout mice and human mutations, demonstrates that Lck kinase activity is critical for normal T cell development, activation, and signaling. Selective inhibition of Lck is expected to offer a new therapy for the treatment of T-cell-mediated autoimmune and inflammatory disease. With the aid of X-ray structure-based analysis, aminopyrimidine amides 2 and 3 were designed from aminoquinazolines 1, which had previously been demonstrated to exhibit potent inhibition of Lck and T cell proliferation. In this report, we describe the synthesis and structure-activity relationships of a series of novel aminopyrimidine amides 3 possessing improved cellular potency and selectivity profiles relative to their aminoquinazoline predecessors 1. Orally bioavailable compound 13b inhibited the anti-CD3-induced production of interleukin-2 (IL-2) in mice in a dose-dependent manner (ED 50 = 9.4 mg/kg).

Postnatal Intermittent Hypoxia and Developmental Programming of Hypertension in Spontaneously Hypertensive Rats: the Role of Reactive Oxygen Species and L-Ca2+ Channels

Hypertension. Jul, 2008  |  Pubmed ID: 18474836

Obstructive and central apneas during sleep are associated with chronic intermittent hypoxia (CIH) and increased cardiovascular morbidity. Spontaneously hypertensive rats exposed to CIH during postnatal days 4 to 30 develop exaggerated hypertension as adults. We hypothesized that reactive oxygen species and altered L-Ca(2+) channel activity may underlie the postnatal programming of exaggerated blood pressure and cardiac remodeling. Newborn male spontaneously hypertensive rats were exposed to CIH (10% and 21% O(2) alternating every 90 seconds, 12 h/d, for postnatal days 4 to 30) or normoxia (room air). In each condition, spontaneously hypertensive rats received daily (SC) 1 of 3 treatments: L-calcium channel blocker nifedipine (5 mg/kg), superoxide dismutase mimetic MnTMPyP pentachloride (10 mg/kg), or vehicle (polyethylene glycol). Blood pressure was evaluated monthly for 6 months after birth, and echocardiographic assessments were conducted at 6 months of age. CIH vehicle-treated rats presented higher systolic blood pressure (187+/-5 mm Hg) as compared with normoxic vehicle treated controls (163+/-2 mm Hg; P<0.001). Postnatal CIH elicited marked increases in left ventricular wall thickness in a pattern of concentric hypertrophy with augmented systolic contractility. The treatment with nifedipine in the CIH group attenuated blood pressure (159+/-2 mm Hg; P<0.001) and normalized left ventricular wall thickness and systolic function, whereas the treatment with SOD mimetic decreased blood pressure (165+/-2 mm Hg; P<0.001) and reduced left ventricular wall thickness without changes in the systolic function. We conclude that Ca(2+) and reactive oxygen species-mediated signaling during intermittent hypoxia are critical mechanisms underlying postnatal programming of an increased severity of hypertension and hypertrophic cardiac remodeling in a genetically susceptible rodent model.

Interleukin (IL)-17 Promotes Macrophages to Produce IL-8, IL-6 and Tumour Necrosis Factor-alpha in Aplastic Anaemia

British Journal of Haematology. Jul, 2008  |  Pubmed ID: 18477039

Aplastic anaemia (AA) is thought to be an autoimmune-mediated disease with active destruction of haematopoietic cells through a T helper type 1 (Th1) cell response. Interleukin (IL)-17 is a potent proinflammatory cytokine produced by activated memory T cells. Recent studies indicate that IL-17 might be an essential effector cytokine in the T-cell mediated autoimmune process. It can drive the production of tumour necrosis factor-alpha (TNF-alpha), IL-1 beta, IL-6 and IL-8 by a variety of cells. The present study investigated the genetic and protein expression of IL-17 in patients with AA. The effect of IL-17 on IL-6 and IL-8 production by macrophages was also studied. AA patients showed an elevated expression of IL17A mRNA in bone marrow mononuclear cells and peripheral blood mononuclear cells. Higher IL-17 in bone marrow and peripheral blood plasma was also observed in AA patients compared with normal controls. IL-17 induced the production of IL-6 and IL-8 by macrophages both from patients with AA and normal controls. IL-17 stimulation also resulted in the production of TNF-alpha. These results suggested that elevated expression of IL-17 and IL-17-induced IL-6, IL-8 and TNF-alpha may be involved in the mechanisms of AA.

Increased T Cell Immunoglobulin Mucin-3 and Its Ligand in Acquired Aplastic Anemia

European Journal of Haematology. Aug, 2008  |  Pubmed ID: 18485114

T cell immunoglobulin mucin-3 (TIM-3) is recently described as a T helper 1 (Th)1-specific molecule, participating in the regulation of immune responses and the pathogenesis of Th1-driven diseases. The TIM-3 pathway, however, has not been investigated in acquired aplastic anemia (AA). In this study, we examined the expression of TIM-3 and interferon-gamma (IFN-gamma) at both transcript and protein levels in 29 acquired AA patients and in 31 controls. Increased mRNA expression of TIM-3 and IFN-gamma were observed in both peripheral blood mononuclear cells (PBMCs) and bone marrow mononuclear cells from AA patients and controls using quantitative real-time reverse transcriptase-polymerase chain reaction. An increase of TIM-3 expression on PBMCs was detected increased in AA patients by flow cytometry. An overproduction of IFN-gamma was determined in the sera from AA patients by enzyme-linked immunoassay. In addition, the expression of TIM-3 ligand, galectin-9, increased in PBMCs from AA patients. The results are the first human data to demonstrate the increase of TIM-3 expression in AA. The enhanced TIM-3 engagement by its ligand in AA patients may play an important role in the pathogenesis of this disease.

Lymphangiogenesis Induced by VEGF-C and VEGF-D Promotes Metastasis and a Poor Outcome in Breast Carcinoma: a Retrospective Study of 61 Cases

Clinical & Experimental Metastasis. 2008  |  Pubmed ID: 18512120

To evaluate lymphangiogenesis in patients with breast carcinoma, explore the underlying mechanism, and study the relationship between lymphangiogenesis and progression of breast carcinoma.

[Study on the Determination of Bovine Serum Albumin Using O-hydroxyphenylfluorone Reagent with Fluorescence Spectrophotometry]

Guang Pu Xue Yu Guang Pu Fen Xi = Guang Pu. Jun, 2008  |  Pubmed ID: 18800717

The reactions were studied for the determination of bovine serum albumin (BSA) using o-hydroxyphenylfluorone (o-HPF) as fluorescence probe reagent with fluorescence spectrophotometry. In the B-R medium, o-HPF reacts with BSA to form the stable complex compound. The reaction system of o-HPF and BSA was binary system, and the method for the determination of BSA was of good selectivity and stability and simplicity. The linear range of o-HPF fluorescence spectrophotometric method was 1.32-18.54 microg x mL(-1) The quenching constant and thermodynamics constant of the fluorescence effects between BSA and o-HPF were calculated. The results showed that the non-covalent binding forces were the binding force between o-HPF and BSA.

Cephalometric Superimpositions

The Angle Orthodontist. Nov, 2008  |  Pubmed ID: 18947269

To test the hypothesis that there is no difference between the information produced by superimposition of serial lateral headfilms on anatomical structures and that produced by superimposition on metallic implants according to the protocols of Björk.

[Study on Determination of Bovine Serum Albumin Using O-hydroxyphenylfluorone Reagent with Fluorescence Spectrophotometry]

Guang Pu Xue Yu Guang Pu Fen Xi = Guang Pu. Aug, 2008  |  Pubmed ID: 18975826

The reaction conditions for the determination of bovine serum albumin (BSA) using o-hydroxyphenylfluorone (o-HPF) as fluorescence probe reagent were studied. In the B-R medium at pH 7.90, o-HPF could react with BSA, producing a stable complex compound which resulted in fluorescent quenching of this binary system. The quantitative assay was carried out based on the relation between the degree of fluorescent quenching and the additional amount of BSA. The method has advantages of good selectivity, stability and simplicity. The linear range of o-HPF fluorescence spectrophotometric method was 1.32-18.54 microg x mL(-1). Moreover, the mechanism of the reaction BSA and o-HPF was discussed, and the quenching constant, and the ther modynamics constant of the fluorescence effects were calculated. The results showed that the nonconvalent binding forces were the binding force between o-HPF and BSA, and the quenching of BSA to o-HPF was probably a single static quenching process.

Induction of Rejection After Small-for-size Liver Transplantation: Size Matters

Journal of Investigative Surgery : the Official Journal of the Academy of Surgical Research. Sep-Oct, 2008  |  Pubmed ID: 19160137

Reduced-size liver transplantation is associated with liver regeneration. This study was designed to analyze the influence of graft size on liver rejection and liver regeneration.

[Study on Mandibular Rotation in 13 Female Subjects Aged from 9.5 to 15.5]

Hua Xi Kou Qiang Yi Xue Za Zhi = Huaxi Kouqiang Yixue Zazhi = West China Journal of Stomatology. Dec, 2008  |  Pubmed ID: 19186854

To evaluate the mandibular rotation in females aged from 9.5 to 15.5 years.

Prodrugs of Fluoro-substituted Benzoates of EGC As Tumor Cellular Proteasome Inhibitors and Apoptosis Inducers

International Journal of Molecular Sciences. Jun, 2008  |  Pubmed ID: 19325839

The most potent catechin in green tea is (-)-epigallocatechin-3-gallate [(-)-EGCG], which, however, is unstable under physiological conditions. To discover more stable and more potent polyphenol proteasome inhibitors, we synthesized several novel fluoro-substituted (-)-EGCG analogs, named F-EGCG analogs, as well as their prodrug forms with all of -OH groups protected by acetate. We report that the prodrug form of one F-EGCG analog exhibited greater potency than the previously reported peracetate of (-)-EGCG to inhibit proteasomal activity, suppress cell proliferation, and induce apoptosis in human leukemia Jurkat T cells, demonstrating the potential of these compounds to be developed into novel anti-cancer and cancer-preventive agents.

Pyridyl-pyrimidine Benzimidazole Derivatives As Potent, Selective, and Orally Bioavailable Inhibitors of Tie-2 Kinase

Bioorganic & Medicinal Chemistry Letters. Jan, 2009  |  Pubmed ID: 19062275

Selective small molecule inhibitors of Tie-2 kinase are important tools for the validation of Tie-2 signaling in pathological angiogenesis. Reported herein is the optimization of a nonselective scaffold into a potent and highly selective inhibitor of Tie-2 kinase.

Increased CD4+ and CD8+ Effector Memory T Cells in Patients with Aplastic Anemia

Haematologica. Mar, 2009  |  Pubmed ID: 19181780

Molecular Simulations Elucidate the Substrate Translocation Pathway in a Glutamate Transporter

Proceedings of the National Academy of Sciences of the United States of America. Feb, 2009  |  Pubmed ID: 19202063

Glutamate transporters are membrane proteins found in neurons and glial cells, which play a critical role in regulating cell signaling by clearing glutamate released from synapses. Although extensive biochemical and structural studies have shed light onto different aspects of glutamate transport, the time-resolved molecular mechanism of substrate (glutamate or aspartate) translocation, that is, the sequence of events occurring at the atomic level after substrate binding and before its release intracellularly remain to be elucidated. We identify an energetically preferred permeation pathway of approximately 23 A between the helix HP1b on the hairpin HP1 and the transmembrane helices TM7 and TM8, using the high resolution structure of the transporter from Pyrococcus horikoshii (Glt(Ph)) in steered molecular dynamics simulations. Detailed potential of mean force calculations along the putative pathway reveal 2 energy barriers encountered by the substrate (aspartate) before it reaches the exit. The first barrier is surmounted with the assistance of 2 conserved residues (S278 and N401) and a sodium ion (Na2); and the second, by the electrostatic interactions with D405 and another sodium ion (Na1). The observed critical interactions and mediating role of conserved residues in the core domain, the accompanying conformational changes (in both substrate and transporter) that relieve local strains, and the unique coupling of aspartate transport to Na(+) dislocation provide insights into methods for modulating substrate transport.

Divergent Tumor Necrosis Factor Receptor-related Remodeling Responses in Heart Failure: Role of Nuclear Factor-kappaB and Inflammatory Activation

Circulation. Mar, 2009  |  Pubmed ID: 19255345

Although preclinical data suggested that tumor necrosis factor-alpha (TNF) neutralization in heart failure (HF) would be beneficial, clinical trials of TNF antagonists were paradoxically negative. We hypothesized that TNF induces opposing inflammatory and remodeling responses in HF that are TNF-receptor (TNFR) specific.

[Importance of "Guidelines for Performing Fetal Cardiac Scan" in Prenatal Screening for Fetal Congenital Heart Disease]

Zhonghua Fu Chan Ke Za Zhi. Feb, 2009  |  Pubmed ID: 19570419

To investigate the application of "Guidelines for performing fetal cardiac scan", issued by the International Society of Ultrasound in Obstetrics and Gynecology in 2006, in prenatal screening of fetal congenital heart disease (CHD).

Immediate Repair of Major Abdominal Wall Defect After Extensive Tumor Excision in Patients with Abdominal Wall Neoplasm: a Retrospective Review of 27 Cases [corrected]

Annals of Surgical Oncology. Oct, 2009  |  Pubmed ID: 19597889

The treatment of abdominal wall neoplasm continues to present a challenging problem because it is not easy to repair the giant defect which is resulted from extensive tumor excision. Some techniques and materials have been reported, but most report a certain technique or material for abdominal wall reconstruction. Therefore, we retrospectively reviewed the treatment of such patients in our department and assessed the reconstruction algorithm in such a situation.

More Attention Should Be Paid to Schizophrenic Patients with Risk of Violent Offences

Psychiatry and Clinical Neurosciences. Aug, 2009  |  Pubmed ID: 19659565

Association Between COMT Gene and Chinese Male Schizophrenic Patients with Violent Behavior

Medical Science Monitor : International Medical Journal of Experimental and Clinical Research. Sep, 2009  |  Pubmed ID: 19721400

Haplotype analysis is hypothesized as having better power than individual SNPs in detecting the association between genotype and phenotype, but this approach has rarely been used in studies of the genetics of violent behavior in schizophrenia. The aim of this study was to further examine the role of the COMT gene in violent behavior.

[The Questionnaire Survey of Present Status of Intensive Care Units in Shandong Province]

Zhongguo Wei Zhong Bing Ji Jiu Yi Xue = Chinese Critical Care Medicine = Zhongguo Weizhongbing Jijiuyixue. Sep, 2009  |  Pubmed ID: 19751567

The Beta2 Integrin CD11b Attenuates Polyinosinic:polycytidylic Acid-induced Hepatitis by Negatively Regulating Natural Killer Cell Functions

Hepatology (Baltimore, Md.). Nov, 2009  |  Pubmed ID: 19821527

The beta2 integrins play a key role in inflammation and immune responses. The beta2 integrin CD11b has been shown recently to be important in the maintenance of tolerance; however, the underlying mechanisms remain to be fully understood. Natural killer (NK) cells are an important effector of innate immunity but are also a regulator of adaptive immune response. How the activating and inhibitory signals are balanced to determine NK cell function needs to be further identified. CD11b expression was dramatically up-regulated on NK cells once they matured and became activated; therefore, we investigated the role of inducible CD11b in the regulation of NK cells. Neutralizing anti-CD11b antibody enhanced cytotoxicity, interferon-gamma (IFN-gamma) and granzyme B production of Toll-like receptor 3 (TLR3)-triggered NK cells. CD11b-deficient NK cells stimulated with or without the TLR3 ligand polyinosinic:polycytidylic acid [poly(I:C)] exhibited more potent cytotoxicity, and higher production of IFN-gamma and granzyme B. Through in vivo depletion of NK cells and adoptive transfer of CD11b-deficient NK cells, we demonstrated that CD11b-mediated suppression of NK cell function was responsible for attenuation of poly(I:C)-induced acute hepatitis by CD11b. CONCLUSION: Our findings demonstrate that CD11b negatively regulates NK cell activation and thus attenuates poly(I:C)-induced acute hepatitis. Our study provides a new mechanistic explanation for maintenance of tolerance and control of inflammation by CD11b.

Inhibitory Effects of Genistein on Metastasis of Human Hepatocellular Carcinoma

World Journal of Gastroenterology : WJG. Oct, 2009  |  Pubmed ID: 19842228

To investigate the inhibitory effects of genistein on metastasis of MHCC97-H hepatocellular carcinoma cells and to explore the underlying mechanism.

[Karyotype Analysis of Chorionic Villi from Pregnant Women with Missed Abortion Using Multiplex Ligation-dependent Probe Amplification]

Zhonghua Fu Chan Ke Za Zhi. Jul, 2009  |  Pubmed ID: 19957550

To evaluate the clinical value of multiplex ligation-dependent probe amplification (MLPA) technique used in karyotype analysis of chorionic villi from missed abortion.

[Vascular Endothelial Growth Factor (VEGF)-D in Association with VEGF Receptor-3 in Lymphatic Metastasis of Breast Cancer]

Ai Zheng = Aizheng = Chinese Journal of Cancer. Dec, 2009  |  Pubmed ID: 19958632

Breast carcinoma is the most common malignant tumor in women. For these patients, lymph node metastasis is one of the most important prognostic factors. Recent studies suggest that lymphangiogenesis can contribute to the lymphatic metastasis in tumors. Several members of vascular endothelial growth factor (VEGF) family, such as VEGF-C, VEGF-D, and VEGF receptor-3 (VEGFR-3), have been found to promote lymphangiogenesis in breast cancer. However, there are still some controversy about the prognostic value of VEGF-D and the relation between VEGFR-3 and lymphangiogenesis. This article tried to provide an overview of the research progress of lymphangiogenic factor VEGF-D and its receptor VEGFR-3 in lymphatic metastasis of breast cancer.

[Fluorescence Study on the Interactions Between G3.0 PAMAM Dendrimers and Bovine Serum Albumin]

Guang Pu Xue Yu Guang Pu Fen Xi = Guang Pu. Oct, 2009  |  Pubmed ID: 20038060

The interaction between amine terminated G3.0 PAMAM dendrimers and bovine serum albumin (BSA) under physiological condition was studied by fluorescence spectroscopy. Our experiments demonstrated that the fluorescence intensity of BSA decreased after the addition of G3.0 PAMAM dendrimers and the quenching mechanism was suggested as static quenching according to the Stern-Volmer equation The binding constant of G3.0 PAMAM dendrimers with BSA was calculated to be 1.067 +/- 0.025 L x mmol(-1). At the same time, synchronous fluorescence and red edge excitation shift (REES) were adopted to review the conformational changes of BSA influenced by G3.0 PAMAM dendrimers, which provides important significance for clinical medication And the results indicated that G3.0 PAMAM dendrimers can change the conformation of BSA. Furthermore, this article also examined the influence of pH and ionic strength on the interactions, from which we can conclude that electrostatic interaction played major roles in the binding process. In conclusion, the fluorescence method is a highly sensitive and convenient way to study intermolecular interaction. Further investigation in this field will provide more important information for understanding the pharmacological effects and toxicities of drugs in human body.

1,4a,7-Trimethyl-7-vinyl-1,2,3,4,4a,4b,5,6,7,9,10,10a-dodeca-hydro-phenanthrene-1-carboxylic Acid

Acta Crystallographica. Section E, Structure Reports Online. 2009  |  Pubmed ID: 21583929

The title compound, pimaric acid, C(20)H(30)O(2), was isolated from a mixture of resin acids. There are three rings in the structure. The two cyclo-hexane rings have classical chair conformations with trans-fused ring junctions. The cyclo-hexene ring appears as a semi-chair.

Antitumor Activity of Novel Fluoro-substituted (-)-epigallocatechin-3-gallate Analogs

Cancer Letters. Jun, 2010  |  Pubmed ID: 19962231

Epidemiological studies support the cancer-preventive effects of green tea and its main constituent (-)-epigallocatechin gallate [(-)-EGCG], however, (-)-EGCG is unstable under physiological conditions. Here we report that two novel fluoro-substituted (-)-EGCG analogs inhibited tumor growth with similar potency to that of Pro-EGCG (1) which has improved potency over parental compound (-)-EGCG in human breast cancer MDA-MB-231 xenografts. MDA-MB-231 tumors treated with each fluoro-substituted (-)-EGCG analog showed proteasome inhibition and apoptotic cell death, suggesting that the proteasome might be one of the cellular targets of fluoro-(-)-EGCGs and that proteasome inhibition is partially responsible for the observed antitumor activity.

A Child with Coexistent Juvenile Xanthogranuloma and Langerhans Cell Histiocytosis

Journal of the American Academy of Dermatology. Feb, 2010  |  Pubmed ID: 19969387

A 15-month-old boy was seen because of two distinct types of lesions, namely, yellowish papules on the scalp and face, and hemorrhagic macules and papules on the trunk. A biopsy specimen from one of the yellowish papules showed histopathologic and immunohistochemical changes of both juvenile xanthogranuloma and Langerhans cell histiocytosis. The section from the center of the biopsy specimen showed a proliferation of foamy histiocytes, among them Touton giant cells, which were positive for CD68, but negative for S-100 and CD1a. At the edges of the specimen was a predominantly histiocytic infiltration in the papillary dermis that was positive for S-100 and CD1a, but negative for CD68. The patient died 12 days after hospital admission consequent to disseminated intravascular coagulopathy. We did not biopsy the hemorrhagic lesions; however, this combination of findings suggests a possible relationship between juvenile xanthogranuloma and Langerhans cell histiocytosis, as previously reported.

Analysis of Urinary Calculi Composition by Infrared Spectroscopy: a Prospective Study of 625 Patients in Eastern China

Urological Research. Apr, 2010  |  Pubmed ID: 20157702

Urolithiasis is a common urologic disease whose prevalence is about 1-20% and increasing throughout the world. The recurrence rate after treatment is more than 50%. Urinary stone analysis is important in determining the possible etiology and the pathophysiology of stone formation. A better understanding of the stone composition may help prevent urinary stone formation. From March 2007 to December 2008, physical analysis of urolithiasis in patients who lived in eastern China for more than 5 years and underwent surgery or shock wave lithotripsy in our hospital or passed their stones spontaneously was carried out using the Fourier transform infrared spectroscopy (FT-IR). Clinical and demographic findings were evaluated and compared with the stone components. Stone analysis was performed in 625 patients. The FT-IR evaluation showed that 234 (37.4%) were pure, and the most frequent was calcium oxalate (33.9%), followed by calcium phosphate (2.7%), and uric acid (0.8%). 391 (62.6%) were mixed stone, calcium oxalate (43.2%) was the most commonly major component, followed by calcium phosphate (16.3%), cystine (1.3%), uric acid (1.1%), and struvite (0.6%). Uric acid (p = 0.029) was the major component found more frequently in men, while struvite (p = 0.037) was more frequent in women. Uric acid (p = 0.031) was more common in lower urinary tract stones, and its formers with the mean age of 55 years were older than those with other components (p = 0.039). In eastern China, the most commonly found pure stone was calcium oxalate, while the most frequent mixed stone was calcium oxalate and calcium phosphate mixture. Stone location, gender, and age may influence stone component.

Effect of Traditional Chinese Medicine Berberine on Type 2 Diabetes Based on Comprehensive Metabonomics

Talanta. May, 2010  |  Pubmed ID: 20298851

A comprehensive metabonomic method, in combination with fingerprint analysis and target analysis, was performed to reveal potential mechanisms of berberine action in the treatment of patients with type 2 diabetes and dyslipidemia. Serum samples of 60 patients before and after treatment with either berberine or placebo were collected. Ultra-performance liquid chromatography and quadrupole time-of-flight tandem mass spectrometry (UPLC Q-TOF MS) coupled with pattern recognition analysis were used to identify changes in global serum metabolites. Compared with placebo, patients before and after berberine treatment could be separated into distinct clusters as displayed by the orthogonal signal correction filtered partial least-squares discriminant analysis (OSC-PLS-DA) score plot, which indicated changes in circulating metabolites after berberine treatment. Among them, free fatty acids changed markedly. These were further quantified by UPLC combined with single quadrupole mass spectrometry (UPLC SQ MS). There was a highly significant decrease in the concentrations of 13 fatty acids following berberine administration. 10 fatty acids also differed statistically from placebo. These results suggest that berberine might play a pivotal role in the treatment of type 2 diabetes through down-regulating the high level of free fatty acids and that comprehensive metabonomic measurements are potentially very useful for studying the mechanisms of action of traditional Chinese medicines.

Wavelength-dependent Differential Interference Contrast Microscopy: Multiplexing Detection Using Nonfluorescent Nanoparticles

Analytical Chemistry. Aug, 2010  |  Pubmed ID: 20614872

The wavelength dependence of plasmonic nanoparticles' contrasts in differential interference contrast (DIC) microscopy has been exploited previously for unambiguous identification and dynamic tracking of these nanoprobes in complex environments (Anal. Chem. 2009, 81, 9203-9208). In the present study, the suitability of multiplexing detection in DIC microscopy was investigated systematically with 19 kinds of nanoparticles of different materials and/or sizes. A unique DIC contrast spectrum was found for each kind of nanoparticle. Multiplexing detection was accomplished by measuring DIC contrasts at a minimum of two specific illumination wavelengths. The main advantages of DIC microscopy for multiplexing detection over other nonfluorescence techniques, such as dark field microscopy and surface-enhanced Raman scattering, were demonstrated by differentiating four kinds of nanoparticles on the cell membrane while providing high-contrast images of both the nanoprobes and cell features.

Discovery of a Potent, Selective, and Orally Bioavailable Pyridinyl-pyrimidine Phthalazine Aurora Kinase Inhibitor

Journal of Medicinal Chemistry. Sep, 2010  |  Pubmed ID: 20684549

The discovery of aurora kinases as essential regulators of cell division has led to intense interest in identifying small molecule aurora kinase inhibitors for the potential treatment of cancer. A high-throughput screening effort identified pyridinyl-pyrimidine 6a as a moderately potent dual inhibitor of aurora kinases -A and -B. Optimization of this hit resulted in an anthranilamide lead (6j) that possessed improved enzyme and cellular activity and exhibited a high level of kinase selectivity. However, this anthranilamide and subsequent analogues suffered from a lack of oral bioavailability. Converting the internally hydrogen-bonded six-membered pseudo-ring of the anthranilamide to a phthalazine (8a-b) led to a dramatic improvement in oral bioavailability (38-61%F) while maintaining the potency and selectivity characteristics of the anthranilamide series. In a COLO 205 tumor pharmacodynamic assay measuring phosphorylation of the aurora-B substrate histone H3 at serine 10 (p-histone H3), oral administration of 8b at 50 mg/kg demonstrated significant reduction in tumor p-histone H3 for at least 6 h.

Screening for Personality Disorders Among Chinese Prison Inmates

Psychiatric Services (Washington, D.C.). Sep, 2010  |  Pubmed ID: 20810600

Effects of Membrane Cholesterol Depletion and GPI-anchored Protein Reduction on Osteoblastic Mechanotransduction

Journal of Cellular Physiology. Dec, 2010  |  Pubmed ID: 21154586

We previously demonstrated that oscillatory fluid flow activates MC3T3-E1 osteoblastic cell calcium signaling pathways via a mechanism involving ATP releases and P2Y(2) puringeric receptors. However, the molecular mechanisms by which fluid flow initiates cellular responses are still unclear. Accumulating evidence suggests that lipid rafts, one of the important membrane structural components, may play an important role in transducing extracellular fluid shear stress to intracellular responses. Due to the limitations of current techniques, there is no direct approach to study the role of lipid rafts in transmitting fluid shear stress. In this study, we targeted two important membrane components associated with lipid rafts, cholesterol and glycosylphosphatidylinositol-anchored proteins, to disrupt the integrity of cell membrane structures. We first demonstrated that membrane cholesterol depletion with the treatment of methyl-β-cyclodextrin inhibits oscillatory fluid flow induced intracellular calcium mobilization and ERK1/2 phosphorylation in MC3T3-E1 osteoblastic cells. Secondly, we used a novel approach to decrease the levels of glycosylphosphatidylinositol-anchored proteins on cell membranes by overexpressing glycosylphosphatidylinositol specific phospholipase D in MC3T3-E1 osteoblastic cells. This resulted in significant inhibition of intracellular calcium mobilization and ERK1/2 phosphorylation in response to oscillatory fluid flow. Finally, we demonstrated that cholesterol depletion inhibited oscillatory fluid flow induced ATP releases, which were responsible for the activation of calcium signaling pathways in MC3T3-E1 osteoblastic cells. Our findings suggest that cholesterol and GPI-anchored proteins, two membrane structural components related to lipid rafts, may play an important role in osteoblastic cell mechanotransduction. © 2010 Wiley-Liss, Inc.

Factors Contributing to Stability of Protraction Facemask Treatment of Class III Malocclusion

Australian Orthodontic Journal. Nov, 2010  |  Pubmed ID: 21175028

To identify the craniofacial characteristics that contribute to long-term stability of protraction facemask treatment of Class III malocclusion.

P2Y(2) Receptors and GRK2 Are Involved in Oscillatory Fluid Flow Induced ERK1/2 Responses in Chondrocytes

Journal of Orthopaedic Research : Official Publication of the Orthopaedic Research Society. Dec, 2010  |  Pubmed ID: 21184510

Mechanical loading is an important factor regulating cartilage metabolism maintained by chondrocytes. However, some of its underlying mechanisms remain poorly understood. In this study, we employed a chondrogenic cell line ATDC5 to investigate roles of P2Y(2) and GRK2 in chondrocyte mechanotransduction. We first confirmed the expression of chondrocyte markers in differentiated ATDC5 cells. We then exposed both differentiated and undifferentiated ATDC5 cells to oscillatory fluid flow, and found that differentiated ATDC5 cells responded to oscillatory fluid flow by increasing COX-2 and aggrecan expressions. More importantly, fluid flow induced ERK1/2 response in differentiated cells was increased more than 10 times compared to those in undifferentiated cells. Furthermore, we found that P2Y(2) mRNA and protein levels in differentiated ATDC5 cells were significantly higher than those in undifferentiated cells. In contrast, GRK2 protein levels in differentiated cells were significantly lower than those in undifferentiated cells. Finally, overexpressions of P2Y(2) and GRK2 in differentiated ATDC5 cells result in a 34% increase and a 21% decrease of the ERK1/2 phosphorylation, respectively, in response to oscillatory fluid flow, suggesting important roles of P2Y(2) and GRK2 in chondrocyte mechanotransduction. © 2010 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res.

Comparison of Craniofacial Characteristics of Typical Chinese and Caucasian Young Adults

European Journal of Orthodontics. Apr, 2011  |  Pubmed ID: 20709723

The purpose of this study was to determine the cephalometric norms of typical Chinese young adult subjects with normal occlusions and well-balanced faces and to compare these norms with those derived from a matched Caucasian sample. Lateral cephalograms of 65 untreated Chinese adults (25 males, mean age 19.3 ± 3.0 years and 40 females, mean age 20.3 ± 3.4 years) were compared with a sample of 90 untreated Caucasian adults (30 males, mean age 24.1 ± 5.7 years and 60 females, mean age 22.9 ± 5.2 years). Each lateral cephalogram was traced and digitized, and conventional cephalometric analyses were applied. Independent sample t-tests were used to compare the values between the two ethic samples. Smaller midfaces and shorter mandibles were observed in Chinese young adults compared with those of Caucasians. The average value of lower anterior face height (ANS-Me) was longer in the Chinese females than that in the Caucasian females (P < 0.001). A greater vertical dimension also was seen in Chinese males compared with Caucasian males when evaluated by analysis of the facial axis angle (P < 0.05). The upper and lower lips were more protrusive in the Chinese, and a more convex facial profile was seen compared with the Caucasian sample. Significant differences in hard and soft tissue characteristics were found between Chinese and Caucasian young adults with normal occlusions and well-balanced faces. Gender and racial/ethnic differences must be taken into consideration during orthodontic diagnosis and treatment planning for the individual patient.

No Association Between Schizophrenia and Rs27388 of the MEGF10 Gene in Chinese Case-control Sample

Psychiatry Research. Apr, 2011  |  Pubmed ID: 20813413

Characterization of Free Radicals Formed from COX-catalyzed DGLA Peroxidation

Free Radical Biology & Medicine. May, 2011  |  Pubmed ID: 21310230

Like arachidonic acid (AA), dihomo-γ-linolenic acid (DGLA) is a 20-carbon ω-6 polyunsaturated fatty acid and a substrate of cyclooxygenase (COX). Through free radical reactions, COX metabolizes DGLA and AA to form well-known bioactive metabolites, namely, the 1 and 2 series of prostaglandins (PGs1 and PGs2), respectively. Unlike PGs2, which are viewed as proinflammatory, PGs1 possess anti-inflammatory and anticancer activities. However, the mechanisms linking the PGs to their bioactivities are still unclear, and radicals generated in COX-DGLA have not been detected. To better understand PG biology and determine whether different reactions occur in COX-DGLA and COX-AA, we have used LC/ESR/MS with a spin trap, α-(4-pyridyl-1-oxide)-N-tert-butyl nitrone (POBN), to characterize the carbon-centered radicals formed from COX-DGLA in vitro, including cellular peroxidation. A total of five types of DGLA-derived radicals were characterized as POBN adducts: m/z 266, m/z 296, and m/z 550 (same as or similar to COX-AA) and m/z 324 and m/z 354 (exclusively from COX-DGLA). Our results suggest that C-15 oxygenation to form PGGs occurs in both COX-DGLA and COX-AA; however, C-8 oxygenation occurs exclusively in COX-DGLA. This new finding will be further investigated for its association with various bioactivities of PGs, with potential implications for inflammatory diseases.

Antioxidant Activity and Phenolic Compositions of Lentil (Lens Culinaris Var. Morton) Extract and Its Fractions

Journal of Agricultural and Food Chemistry. Mar, 2011  |  Pubmed ID: 21332205

Phenolic compounds were extracted from Morton lentils using acidified aqueous acetone. The crude Morton extract (CME) was applied onto a macroresin column and desorbed by aqueous methanol to obtain a semipurified Morton extract (SPME). The SPME was further fractionated over a Sephadex LH-20 column into five main fractions (I-V). The phytochemical contents such as total phenolic content (TPC), total flavonoid content (TFC), and condensed tannin content (CTC) of the CME, SPME, and its fractions were examined by colorimetric methods. Antioxidant activity of extracts and fractions were screened by DPPH scavenging activity, Trolox equivalent antioxidant capacity (TEAC), ferric reduced antioxidant power (FRAP), and oxygen radical absorbing capacity (ORAC) methods. In addition, the compositions of active fractions were determined by HPLC-DAD and HPLC-MS methods. Results showed that the fraction enriched in condensed tannins (fraction V) exhibited significantly higher values of TPC, CTC, and antioxidant activity as compared to the crude extract, SPME, and low molecular weight fractions (I-IV). Eighteen compounds existed in those fractions, and 17 were tentatively identified by UV and MS spectra. HPLC-MS analysis revealed fraction II contained mainly kaempferol glycoside, fractions III and IV mainly contained flavonoid glycosides, and fraction V was composed of condensed tannins. The results suggested that the extract of Morton lentils is a promising source of antioxidant phenolics and may be used as a dietary supplement for health promotion.

Identification of Forensically Significant Calliphorids Based on Mitochondrial DNA Cytochrome Oxidase I (COI) Gene in China

Forensic Science International. Apr, 2011  |  Pubmed ID: 21371834

Discovery of 2,4-bis-arylamino-1,3-pyrimidines As Insulin-like Growth Factor-1 Receptor (IGF-1R) Inhibitors

Bioorganic & Medicinal Chemistry Letters. Apr, 2011  |  Pubmed ID: 21414779

The insulin-like growth factor-1 receptor (IGF-1R) plays an important role in the regulation of cell growth and differentiation, and in protection from apoptosis. IGF-1R has been shown to be an appealing target for the treatment of human cancer. Herein, we report the synthesis, structure-activity relationships (SAR), X-ray cocrystal structure and in vivo tumor study results for a series of 2,4-bis-arylamino-1,3-pyrimidines.

Single Particle Orientation and Rotation Tracking Discloses Distinctive Rotational Dynamics of Drug Delivery Vectors on Live Cell Membranes

Journal of the American Chemical Society. Apr, 2011  |  Pubmed ID: 21438558

Engineered nanoparticles have emerged as potentially revolutionary drug and gene delivery vectors. Using rod-shaped gold nanoparticles as a model, we studied for the first time the rotational dynamics of nanoparticle vectors on live cell membranes and its impact on the fate of these nanoparticle vectors. The rotational motions of gold nanorods with various surface modifiers were tracked continuously at 200 frames/s under a differential interference contrast microscope. We found that the rotational behaviors of gold nanorod vectors are strongly related to their surface charges. Specific surface functional groups and the availability of receptors on cell membranes also contribute to the rotational dynamics. The study of rotational brownian motion of nanoparticles on cell membranes will lead to a better understanding of the mechanisms of drug delivery and provide guidance in designing surface modification strategies for drug delivery vectors under various circumstances.

P2Y(2) Receptors and GRK2 Are Involved in Oscillatory Fluid Flow Induced ERK1/2 Responses in Chondrocytes

Journal of Orthopaedic Research : Official Publication of the Orthopaedic Research Society. Jun, 2011  |  Pubmed ID: 21520257

Mechanical loading is an important factor regulating cartilage metabolism maintained by chondrocytes. However, some of its underlying mechanisms remain poorly understood. In this study, we employed a chondrogenic cell line ATDC5 to investigate roles of P2Y(2) and GRK2 in chondrocyte mechanotransduction. We first confirmed the expression of chondrocyte markers in differentiated ATDC5 cells. We then exposed both differentiated and undifferentiated ATDC5 cells to oscillatory fluid flow, and found that differentiated ATDC5 cells responded to oscillatory fluid flow by increasing COX-2 and aggrecan expressions. More importantly, fluid flow induced ERK1/2 response in differentiated cells was increased more than 10 times compared to those in undifferentiated cells. Furthermore, we found that P2Y(2) mRNA and protein levels in differentiated ATDC5 cells were significantly higher than those in undifferentiated cells. In contrast, GRK2 protein levels in differentiated cells were significantly lower than those in undifferentiated cells. Finally, overexpressions of P2Y(2) and GRK2 in differentiated ATDC5 cells result in a 34% increase and a 21% decrease of the ERK1/2 phosphorylation, respectively, in response to oscillatory fluid flow, suggesting important roles of P2Y(2) and GRK2 in chondrocyte mechanotransduction.

Effect of the Traditional Chinese Medicine Tongxinluo on Endothelial Dysfunction Rats Studied by Using Urinary Metabonomics Based on Liquid Chromatography-mass Spectrometry

Journal of Pharmaceutical and Biomedical Analysis. Aug, 2011  |  Pubmed ID: 21620604

A urinary metabonomic method based on ultra-fast liquid chromatography coupled with ion trap-time of flight mass spectrometry (UFLC/MS-IT-TOF) was employed to study the preventive efficacy and the metabolic changes caused by simavastatin and the traditional Chinese medicine tongxinluo in endothelial dysfunction rats. Principal component analysis (PCA) was applied to study metabolic patterns of endothelial dysfunction rats and healthy control rats. 1-Methyladenosine, indoxyl sulfate, hippuric acid, riboflavin, coproporphyrin, and p-cresol glucuronide were identified as potential biomarkers, indicating that pathways of adenine, tryptophan, phenylalanine, riboflavin and porphyrin metabolism were disturbed in endothelial dysfunction rats. Applications of simvastatin and tongxinluo to endothelial dysfunction rats improved endothelial function according to the results of histopathology and measurements of endothelin-1 and nitric oxide. Metabonomic studies suggested that tongxinluo prevents endothelial dysfunction by regulating multiple metabolic pathways to their normal state, whereas simvastatin only altered selected metabolic pathways. This research demonstrated that metabonomics is a powerful and promising tool for disease investigation and the efficacy evaluation of complex traditional Chinese medicines.

Comparison of Two Porcine-derived Materials for Repairing Abdominal Wall Defects in Rats

PloS One. 2011  |  Pubmed ID: 21637777

The purpose of this study was to compare the mechanical properties, host responses and incorporation of porcine small intestine submucosa (PSIS) and porcine acellular dermal matrix (PADM) in a rat model of abdominal wall defect repair.

Effects of Membrane Cholesterol Depletion and GPI-anchored Protein Reduction on Osteoblastic Mechanotransduction

Journal of Cellular Physiology. Sep, 2011  |  Pubmed ID: 21660958

We previously demonstrated that oscillatory fluid flow activates MC3T3-E1 osteoblastic cell calcium signaling pathways via a mechanism involving ATP releases and P2Y(2) puringeric receptors. However, the molecular mechanisms by which fluid flow initiates cellular responses are still unclear. Accumulating evidence suggests that lipid rafts, one of the important membrane structural components, may play an important role in transducing extracellular fluid shear stress to intracellular responses. Due to the limitations of current techniques, there is no direct approach to study the role of lipid rafts in transmitting fluid shear stress. In this study, we targeted two important membrane components associated with lipid rafts, cholesterol, and glycosylphosphatidylinositol-anchored proteins (GPI-anchored proteins), to disrupt the integrity of cell membrane structures. We first demonstrated that membrane cholesterol depletion with the treatment of methyl-β-cyclodextrin inhibits oscillatory fluid flow induced intracellular calcium mobilization and ERK1/2 phosphorylation in MC3T3-E1 osteoblastic cells. Secondly, we used a novel approach to decrease the levels of GPI-anchored proteins on cell membranes by overexpressing glycosylphosphatidylinositol-specific phospholipase D in MC3T3-E1 osteoblastic cells. This resulted in significant inhibition of intracellular calcium mobilization and ERK1/2 phosphorylation in response to oscillatory fluid flow. Finally, we demonstrated that cholesterol depletion inhibited oscillatory fluid flow induced ATP releases, which were responsible for the activation of calcium signaling pathways in MC3T3-E1 osteoblastic cells. Our findings suggest that cholesterol and GPI-anchored proteins, two membrane structural components related to lipid rafts, may play an important role in osteoblastic cell mechanotransduction.

Fluorescent Liposomes for Differential Interactions with Glycosaminoglycans

Analytical Chemistry. Aug, 2011  |  Pubmed ID: 21675793

We have successfully synthesized a lipid containing the pyranine dye as the hydrophilic headgroup. This lipid was incorporated into liposomes with 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine as the major component. The resultant liposomes displayed differential modulations in fluorescence emission intensity in the presence of nanomolar concentrations of different glycosaminoglycans. Linear discriminant analysis of the fluorescence response data demonstrate that the liposomes are able to distinguish between different GAGs. In addition, we also demonstrate that the liposomes incorporating the pyranine lipid are able to distinguish between dilute serum from healthy individuals and serum containing elevated chondroitin sulfate (simulated serum from an Alzheimer's disease patient).

Tumor Necrosis Factor Receptor 2 Signaling Limits β-adrenergic Receptor-mediated Cardiac Hypertrophy in Vivo

Basic Research in Cardiology. Nov, 2011  |  Pubmed ID: 21691899

The in vivo role of TNF signaling in the genesis of β-adrenergic receptor (β-AR)-mediated cardiac hypertrophy is unknown. Wild-type (WT), TNF receptor 1 (TNFR1)-/- and TNFR2-/- mice were given isoproterenol (ISO, 12.5 μg/kg/h) or saline (SAL) for 1 or 7 days. In WT mice, 7 days of ISO yielded chamber/myocyte hypertrophy and hyperdynamic function without hypertension or fibrosis. WT ISO hearts exhibited an early (1 day) pro-inflammatory response with significant (p < 0.05) activation of nuclear factor (NF)-κB and activator protein 1 (AP-1) and upregulation of TNF, interleukin (IL)-1β and IL-6, inducible nitric oxide synthase (iNOS) and monocyte chemotactic protein-1 (MCP-1), together with increased anti-inflammatory IL-10. This response diminished markedly by 7 days. As compared with WT ISO mice, TNFR1-/- ISO mice exhibited significantly (p < 0.05) less NF-κB and AP-1 activation, less IL-1β, TNF, iNOS and MCP-1 upregulation, but greater IL-10 at 1 day. However, there were no differences in hypertrophy or contractility at 7 days. In contrast, TNFR2-/- ISO mice exhibited augmented NF-κB and AP-1 activation, increased IL-1β and diminished IL-10 expression at 1 day, and significant exaggeration of hypertrophy and less contractile augmentation at 7 days. Moreover, TNFR2-/- mice exposed to tenfold higher ISO doses displayed significant mortality. TNF signaling contributes to β-AR-mediated cardiac remodeling in vivo in a receptor-specific manner. Unopposed TNFR1 activation is pro-inflammatory, pro-hypertrophic and promotes functional decline. However, co-activation of TNFR2 during β-AR stress is anti-inflammatory and counterbalances these deleterious effects. TNF modulatory strategies that maintain TNFR2 signaling may help prevent the detrimental long-term effects of β-AR stimulation in the heart.

LC/ESR/MS Study of PH-dependent Radical Generation from 15-LOX-catalyzed DPA Peroxidation

Free Radical Biology & Medicine. Oct, 2011  |  Pubmed ID: 21807091

Docosapentaenoic acid (DPA) is a unique fatty acid that exists in two isomeric forms (n-3 and n-6), which differ in their physiological behaviors. DPA can undergo free radical-mediated peroxidation via lipoxygenase (LOX). 15-LOX, one of the LOX isomers, has received much attention in cancer research because of its very different expression level in normal tissues compared to tumors and some bioactive fatty acid metabolites modulating the tumorigenic pathways in cancer. However, the mechanism linking 15-LOX, DPA metabolites, and their bioactivities is still unclear, and the free radicals generated in DPA peroxidation have never been characterized. In this study, we have studied radicals formed from both soybean and human cellular (PC3-15LOS cells) 15-LOX-catalyzed peroxidation of DPAs at various pH's using a combination of LC/ESR/MS with the spin trapping technique. We observed a total of three carbon-centered radicals formed in 15-LOX-DPA (n-3) stemming from its 7-, 17-, and 20-hydroperoxides, whereas only one formed from 17-hydroperoxide in DPA (n-6). A change in the reaction pH from 8.5 (15-LOX enzyme optimum) to 7.4 (physiological) and to 6.5 (tumor, acidic) not only decreased the total radical formation but also altered the preferred site of oxygenation. This pH-dependent alteration of radical formation and oxygenation pattern may have significant implications and provide a basis for our ongoing investigations of LOXs as well as fatty acids in cancer biology.

Manganese Nanoparticle Activates Mitochondrial Dependent Apoptotic Signaling and Autophagy in Dopaminergic Neuronal Cells

Toxicology and Applied Pharmacology. Nov, 2011  |  Pubmed ID: 21856324

The production of man-made nanoparticles for various modern applications has increased exponentially in recent years, but the potential health effects of most nanoparticles are not well characterized. Unfortunately, in vitro nanoparticle toxicity studies are extremely limited by yet unresolved problems relating to dosimetry. In the present study, we systematically characterized manganese (Mn) nanoparticle sizes and examined the nanoparticle-induced oxidative signaling in dopaminergic neuronal cells. Differential interference contrast (DIC) microscopy and transmission electron microscopy (TEM) studies revealed that Mn nanoparticles range in size from single nanoparticles (~25 nM) to larger agglomerates when in treatment media. Manganese nanoparticles were effectively internalized in N27 dopaminergic neuronal cells, and they induced a time-dependent upregulation of the transporter protein transferrin. Exposure to 25-400 μg/mL Mn nanoparticles induced cell death in a time- and dose-dependent manner. Mn nanoparticles also significantly increased ROS, accompanied by a caspase-mediated proteolytic cleavage of proapoptotic protein kinase Cδ (PKCδ), as well as activation loop phosphorylation. Blocking Mn nanoparticle-induced ROS failed to protect against the neurotoxic effects, suggesting the involvement of other pathways. Further mechanistic studies revealed changes in Beclin 1 and LC3, indicating that Mn nanoparticles induce autophagy. Primary mesencephalic neuron exposure to Mn nanoparticles induced loss of TH positive dopaminergic neurons and neuronal processes. Collectively, our results suggest that Mn nanoparticles effectively enter dopaminergic neuronal cells and exert neurotoxic effects by activating an apoptotic signaling pathway and autophagy, emphasizing the need for assessing possible health risks associated with an increased use of Mn nanoparticles in modern applications.

PI3K/Akt and MAPK/ERK1/2 Signaling Pathways Are Involved in IGF-1-induced VEGF-C Upregulation in Breast Cancer

Journal of Cancer Research and Clinical Oncology. Nov, 2011  |  Pubmed ID: 21904903

To investigate the signaling pathways involved in insulin-like growth factor-1 (IGF-1)-induced vascular endothelial growth factor C (VEGF-C) up-regulation and lymphatic metastasis in MDA-MB-231 breast cancer cells.

Chronic Oral Exposure to the Aldehyde Pollutant Acrolein Induces Dilated Cardiomyopathy

American Journal of Physiology. Heart and Circulatory Physiology. Nov, 2011  |  Pubmed ID: 21908791

Environmental triggers of dilated cardiomyopathy are poorly understood. Acute exposure to acrolein, a ubiquitous aldehyde pollutant, impairs cardiac function and cardioprotective responses in mice. Here, we tested the hypothesis that chronic oral exposure to acrolein induces inflammation and cardiomyopathy. C57BL/6 mice were gavage-fed acrolein (1 mg/kg) or water (vehicle) daily for 48 days. The dose was chosen based on estimates of human daily unsaturated aldehyde consumption. Compared with vehicle-fed mice, acrolein-fed mice exhibited significant (P < 0.05) left ventricular (LV) dilatation (LV end-diastolic volume 36 ± 8 vs. 17 ± 5 μl), contractile dysfunction (dP/dt(max) 4,697 ± 1,498 vs. 7,016 ± 1,757 mmHg/s), and impaired relaxation (tau 15.4 ± 4.3 vs. 10.4 ± 2.2 ms). Histological and biochemical evaluation revealed myocardial oxidative stress (membrane-localized protein-4-hydroxy-trans-2-nonenal adducts) and nitrative stress (increased protein-nitrotyrosine) and varying degrees of plasma and myocardial protein-acrolein adduct formation indicative of physical translocation of ingested acrolein to the heart. Acrolein also induced myocyte hypertrophy (~2.2-fold increased myocyte area, P < 0.05), increased apoptosis (~7.5-fold), and disrupted endothelial nitric oxide synthase in the heart. DNA binding studies, immunohistochemistry, and PCR revealed significant (P < 0.05) activation of nuclear factor-κB in acrolein-exposed hearts, along with upregulated gene expression of proinflammatory cytokines tumor necrosis factor-α and interleukin-1β. Long-term oral exposure to acrolein, at an amount within the range of human unsaturated aldehyde intake, induces a phenotype of dilated cardiomyopathy in the mouse. Human exposure to acrolein may have analogous effects and raise consideration of an environmental, aldehyde-mediated basis for heart failure.

Hepatoprotective and Antioxidant Effects of Licorice Extract Against CCl(4)-Induced Oxidative Damage in Rats

International Journal of Molecular Sciences. 2011  |  Pubmed ID: 22072903

Licorice has been used in Chinese folk medicine for the treatment of various disorders. Licorice has the biological capabilities of detoxication, antioxidation, and antiinfection. In this study, we evaluated the antihepatotoxic effect of licorice aqueous extract (LE) on the carbon tetrachloride (CCl(4))-induced liver injury in a rat model. Hepatic damage, as reveled by histology and the increased activities of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) activities, and decreased levels of serum total protein (TP), albumin (Alb) and globulin (G) were induced in rats by an administration of CCl(4) at 3 mL/kg b.w. (1:1 in groundnut oil). Licorice extract significantly inhibited the elevated AST, ALP and ALT activities and the decreased TP, Alb and G levels caused by CCl(4) intoxication. It also enhanced liver super oxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR), Glutathione S-transferase (GST) activities and glutathione (GSH) level, reduced malondialdehyde (MDA) level. Licorice extract still markedly reverses the increased liver hydroxyproline and serum TNF-α levels induced by CCl(4) intoxication. The data of this study support a chemopreventive potential of licorice extract against liver oxidative injury.

Discovery of Potent and Highly Selective Thienopyridine Janus Kinase 2 Inhibitors

Journal of Medicinal Chemistry. Dec, 2011  |  Pubmed ID: 22087750

Developing Janus kinase 2 (Jak2) inhibitors has become a significant focus for small molecule drug discovery programs in recent years due to the identification of a Jak2 gain-of-function mutation in the majority of patients with myeloproliferative disorders (MPD). Here, we describe the discovery of a thienopyridine series of Jak2 inhibitors that culminates with compounds showing 100- to >500-fold selectivity over the related Jak family kinases in enzyme assays. Selectivity for Jak2 was also observed in TEL-Jak cellular assays, as well as in cytokine-stimulated peripheral blood mononuclear cell (PBMC) and whole blood assays. X-ray cocrystal structures of 8 and 19 bound to the Jak2 kinase domain aided structure-activity relationship efforts and, along with a previously reported small molecule X-ray cocrystal structure of the Jak1 kinase domain, provided structural rationale for the observed high levels of Jak2 selectivity.

[Effect of Epimedii Folium Processed with Different Refining Temperatures and Amounts of Sheep's Oil on Kidney-yang Deficiency Rats]

Zhongguo Zhong Yao Za Zhi = Zhongguo Zhongyao Zazhi = China Journal of Chinese Materia Medica. Aug, 2011  |  Pubmed ID: 22097341

To investigate the effects of refining temperatures and amounts of sheep's oil used in processing Epimedii Folium on Kedney-yang deficiency rats.

Musculature Tissue Engineering to Repair Abdominal Wall Hernia

Artificial Organs. Dec, 2011  |  Pubmed ID: 22188638

Hernia repair is one of the most frequently performed operations in surgical clinics. Tissue engineering provides insights for the treatment of abdominal wall hernias and other disorders involving deficiencies in the musculature. The present review summarizes the mechanisms of muscle development and regeneration and provides an overview of tissue engineering strategies for the construction of muscles.

RNAi Silencing of the MEKK3 Gene Promotes TRAIL-induced Apoptosis in MCF-7 Cells and Suppresses the Transcriptional Activity of NF-κB

Oncology Reports. Feb, 2012  |  Pubmed ID: 22020406

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a member of the TNF family of cytokines, which can induce apoptotic cell death in a variety of tumor cells or transformed cells, yet, it is relatively non-toxic to most normal cells. Consequently, TRAIL was thought to be a promising agent for cancer therapy. However, recent research reports revealed that many tumors are unresponsive to TRAIL treatment. Apoptotic agents were identified that when used in combination with TRAIL can sensitize tumor cells to TRAIL-mediated apoptosis. It was demonstrated that MEKK3-siRNA sensitized MCF-7 cells to TRAIL cytoxicity. In addition, we investigated the discrepancy of the expression of MEKK3 in breast cancers. It was concluded that elevated MEKK3 expression is found at high frequencies in breast cancer compared to normal breast tissue. Further experiments on the signal machinery showed that MEKK3-siRNA increased the sensitivity of MCF-7 cells to TRAIL by suppressing the transcription activity of NF-κB, and enhancing the caspase-processing to generate executive apoptotic signals. These findings indicate that down-regulation of MEKK3 by siRNA approaches will lead to successful treatment of human breast cancer with TRAIL.

High Throughput Virus Plaque Quantitation Using a Flatbed Scanner

Journal of Virological Methods. Jan, 2012  |  Pubmed ID: 22044905

The plaque assay is a standard technique for measuring influenza virus infectivity and inhibition of virus replication. Counting plaque numbers and quantifying virus infection of cells in multiwell plates quickly, accurately and automatically remain a challenge. Visual inspection relies upon experience, is subjective, often time consuming, and has less reproducibility than automated methods. In this paper, a simple, high throughput imaging-based alternative is proposed which uses a flatbed scanner and image processing software to quantify the infected cell population and plaque formation. Quantitation results were evaluated with reference to visual counting and achieved better than 80% agreement. The method was shown to be particularly advantageous in titration of the number of plaques and infected cells when influenza viruses produce a heterogeneous population of small plaques. It was also shown to be insensitive to the densities of plaques in determination of neutralization titres and IC(50)s of drug susceptibility. In comparison to other available techniques, this approach is cost-effective, relatively accurate, and readily available.

Dual-modality Single Particle Orientation and Rotational Tracking of Intracellular Transport of Nanocargos

Analytical Chemistry. Jan, 2012  |  Pubmed ID: 22141395

The single particle orientation and rotational tracking (SPORT) technique was introduced recently to follow the rotational motion of plasmonic gold nanorod under a differential interference contrast (DIC) microscope. In biological studies, however, cellular activities usually involve a multiplicity of molecules; thus, tracking the motion of a single molecule/object is insufficient. Fluorescence-based techniques have long been used to follow the spatial and temporal distributions of biomolecules of interest thanks to the availability of multiplexing fluorescent probes. To know the type and number of molecules and the timing of their involvement in a biological process under investigation by SPORT, we constructed a dual-modality DIC/fluorescence microscope to simultaneously image fluorescently tagged biomolecules and plasmonic nanoprobes in living cells. With the dual-modality SPORT technique, the microtubule-based intracellular transport can be unambiguously identified while the dynamic orientation of nanometer-sized cargos can be monitored at video rate. Furthermore, the active transport on the microtubule can be easily separated from the diffusion before the nanocargo docks on the microtubule or after it undocks from the microtubule. The potential of dual-modality SPORT is demonstrated for shedding new light on unresolved questions in intracellular transport.

Multidrug-resistant Gram-negative Bacterial Infections After Liver Transplantation - Spectrum and Risk Factors

The Journal of Infection. Mar, 2012  |  Pubmed ID: 22198738

Gram-negative bacilli infections, especially multidrug-resistant gram-negative bacilli infections, are the leading cause of high mortality after liver transplantation. This study sought to investigate the type of infection, infection rate, pathogenic spectrum, antibiotic-resistance profile, risk factors, and epidemiology of multidrug-resistant gram-negative bacterial infection.

A Role for Primary Cilia in Glutamatergic Synaptic Integration of Adult-born Neurons

Nature Neuroscience. Feb, 2012  |  Pubmed ID: 22306608

The sequential synaptic integration of adult-born neurons has been widely examined in rodents, but the mechanisms regulating the integration remain largely unknown. The primary cilium, a microtubule-based signaling center, is essential for vertebrate development, including the development of the CNS. We examined the assembly and function of the primary cilium in the synaptic integration of adult-born mouse hippocampal neurons. Primary cilia were absent in young adult-born neurons, but assembled precisely at the stage when newborn neurons approach their final destination, further extend dendrites and form synapses with entorhinal cortical projections. Conditional deletion of cilia from adult-born neurons induced severe defects in dendritic refinement and synapse formation. Deletion of primary cilia led to enhanced Wnt and β-catenin signaling, which may account for these developmental defects. Taken together, our findings identify the assembly of primary cilia as a critical regulatory event in the dendritic refinement and synaptic integration of adult-born neurons.

Multiple Roles of Dihomo-gamma-linolenic Acid Against Proliferation Diseases

Lipids in Health and Disease. Feb, 2012  |  Pubmed ID: 22333072

ABSTRACT: Considerable arguments remain regarding the diverse biological activities of polyunsaturated fatty acids (PUFA). One of the most interesting but controversial dietary approaches focused on the diverse function of dihomo-dietary gamma-linolenic acid (DGLA) in anti-inflammation and anti-proliferation diseases, especially for cancers. This strategy is based on the ability of DGLA to interfere in cellular lipid metabolism and eicosanoid (cyclooxygenase and lipoxygenase) biosynthesis. Subsequently, DGLA can be further converted by inflammatory cells to 15-(S)-hydroxy-8,11,13-eicosatrienoic acid and prostaglandin E1 (PGE1). This is noteworthy because these compounds possess both anti-inflammatory and anti-proliferative properties. PGE1 could also induce growth inhibition and differentiation of cancer cells. Although the mechanism of DGLA has not yet been elucidated, it is significant to anticipate the antitumor potential benefits from DGLA.

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