Role of Janus kinase 2/signal transducer and activator of transcription 3 signaling pathway in attenuation of myocardial ischemia-reperfusion injury by teramethylpyrazine in rats / 中华麻醉学杂志

ObjectiveTo evaluate the role of Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signaling pathway in attenuation of myocardial ischemia-reperfusion (I/R) injury by tetramethylpyrazine in rats.MethodsSixty-four healthy male Wistar rats weighing 250-300 g were randomly divided into 4 groups( n ＝ 16 each):sham operation group (group S),myocardial I/R group(group I/R),teramethylpyrazine group (group T) and AG,490( a JAK2 inhibitor) group (group AG).Myocardial I/R was induced by 30 min occlusion of left anterior desecending coronary artery (LAD) followed by 120 min reperfusion in groups I/R,T and A.In groups T and A teramethylpyrazine 20 mg/kg was injected iv 20 min before LAD occlusion.In group A AG490 3 tμg/g was injected iv at 5 min before reperfusion.Blood samples were then taken from inferior vena cava at 120 min of reperfusion for measurement of serum creatine phosphokinase (CK) and lactose dehydrogenase (LDH) activities.Myocardial infarct size was then measured and myocardial tissue was obtained for microscopic examination.ResultsSerum CK and LDH activities were significantly higher in group I/R than in group S.Pretreatment with tetramethylpyrazine significantly decreased myocardial infarct size and I/R-induced increase in serum CK and LDH activities and histologic damage.The protective effect of tetramethylpyrazine against myocardial 1/R injury was attenuated by postconditioning with AG490.ConclusionJAK2/STAT3 signaling pathway is involved in attenuation of myocardial I/R injury by tetramethyl pyrazine in rats.

Study on leptin enhancing collagen systhesis in wounded rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the effect of leptin on collagen systhesis in wounded rats.</p><p><b>METHODS</b>Thirty male Wistar rats, weight (180 +/- 20)g, were randomly divided into three groups (n = 10) by weight: normal depilation group, wound control group and leptin treatment group and ten rats were included in each group. A full-thickness defect measuring 2 x 2.5 cm was made in the back of rats in wound control group and leptin treatment group. Each wound in rats of leptin treatment group was applied topically with 0.1 ml leptin solution (2.0 microg leptin), daily for 7 days and that of wound control group with equivalent saline solution. All rats were killed and then granulation tissues samples and skin were collected to examine the synthesis of collagen.</p><p><b>RESULTS</b>Hydroxyproline content in granulation tissues of in leptin treatment group (33.92 +/- 3.09) mg/g were significantly increased than those in control group (29.55 +/- 3.59 mg/g, P < 0.05). The mRNA expressions of collagen I and III were significantly enhanced in leptin treatment group (0.96 +/- 0.09, 0.09 +/- 0.06) than those in control group (0.80 +/- 0.03, 0.08 +/- 0.03). The levels of type I and III collagen were significantly increased in leptin treatment group than those in control group.</p><p><b>CONCLUSION</b>Leptin applied topically can accelerate wound healing through enhancing gene expression of type I and III collagen and synthesis of collagen in wound tissue.</p>

High-risk human papilloma virus DNA detection kit (cervista HPV HR) should be highly validated clinically in cervical cancer screening programs / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>The aim of this study is to evaluate the clinical significance of High-risk Human Papilloma virus DNA Detection Kit (Cervista HPV HR) designed to the utilized in cervical cancer screening programs.</p><p><b>METHODS</b>The investigation for Cervista HPV HR test is designed to detect 437 residual liquid-based cytology specimens collected during routine liquid-based Pap tests at standard care vistis and to identify the presence of HR HPV. We compared Cervista HPV HR Test against standard PCR, in order to examine the performance of Cervista HPV HR Test in populations with cervical intraepithelial neoplasia grade 2+ (CIN 2, CIN 3 and Cancer, CIN 2+), and the capabilities of A5/A6, A7, A9 oligonucleotides of Cervista for predicting CIN2+.</p><p><b>RESULTS</b>The accuracy of Cervista compared to PCR with bi-directional sequencing was 88.26%. The positive percent of Cervista HPV HR Test and PCR were 38.96% and 29.08%, respectively. The sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) of Cervista HPV HR Test for the detection of CIN2+ were 98.46%, 58.49%, 99.54% and 29.68%, respectively. The A9 oligonucleotides positivity percent was significantly higher in CIN2 + (odds ratio: 24.037, 95% CI: 10.086 - 57.283).</p><p><b>CONCLUSION</b>The Cervista HPV HR test can be clinically used for detecting HR HPV types during routine cervical cancer screening. A9 oligonucleotides were also strongly associated with CIN2+ diagnosis, which is improtant in cervical cancer screening for triage to colposcopy.</p>

Akt-centered amplification loop plays a critical role in vascular endothelial growth factor/stromal cell-derived factor 1-α cross-talk and cardioprotection / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Vascular endothelial growth factor (VEGF) is one of major mediators of angiogenesis and survival factor in some tissue, however, its direct effects on cardiomyocytes remain poorly understood.</p><p><b>METHODS</b>Rat neonatal ventricular myocytes were cultured in vitro. Akt phosphorylation was measured by Western blotting; the expression of stromal cell-derived factor α (SDF-1α)/CXCR4 axis was evaluated by real-time PCR and Western blotting. LY294002 and AMD3100 were used to interfere with the signaling of VEGF and SDF-1α/CXCR4 axis. Cardiac myocytes viability and injury were evaluated by trypan blue staining and lactate dehydrogenase (LDH) release.</p><p><b>RESULTS</b>Treatment of neonatal rat ventricular myocytes with VEGF induced phosphorylation of Akt in a dose and Flk-1 dependent manner. VEGF attenuated H2O2 induced cardiac myocyte death. The phosphoinositol-3-kinase (PI3K) inhibitor, LY294002 and Flk-1 antibody abolished the beneficial effects of VEGF on H2O2 induced cell death. In the mean time SDF-1α-CXCR4 axis was up-regulated by VEGF through PI3K-Akt signaling and contributed to the protective effects of VEGF on H2O2 induced cell death. Interestingly, SDF-1α also promoted production of VEGF in cultured cardiac myocytes and LY294002 reversed the up-regulation of VEGF induced by SDF-1α.</p><p><b>CONCLUSION</b>VEGF has direct protective effects on cardiomyocytes; a crosstalk between VEGF and SDF-1α through PI3K-Akt serves a survival role in cardiomyocytes in vitro.</p>

Nitric oxide induces heat shock protein 72 production and delayed protection against myocardial ischemia in rabbits via activating protein kinase C / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Nitric oxide (NO) is a biologically active molecule which has been reported to protect the heart against ischemia and reperfusion injury in different species. This study aimed to test the hypothesis that nitric oxide may induce the expression of heat shock protein 72 (HSP72) which may protect the heart against ischemia.</p><p><b>METHODS</b>Rabbits were given intravenous saline or S-nitroso-N-acetylpenicillamine (SNAP), a nitric oxide donor, or Zaprinast, an inhibitor of cyclic guanosine monophosphate (GMP)-phosphodiesterase, which may increase myocardial cyclic GMP content. Twenty-four hours later, the rabbits were either sampled to measure HSP72, or induced with a 30-minute coronary occlusion followed by a 120-minute reperfusion, and then the infarct size was measured. Meanwhile, chelerythrine (CHE, an inhibitor of protein kinase C) was given intravenously 5 minutes before SNAP injection and the effect on HSP72 expression and infarct size was determined.</p><p><b>RESULTS</b>Twenty-four hours after pretreatment, immunoblotting showed HSP72 expression increased in the SNAP group compared with control groups, and this was blocked by CHE. Myocardial infarct size in the SNAP group was smaller than that of the control group ((32.4 +/- 5.8)% vs (51.1 +/- 4.7)%, P < 0.05). Pretreated with CHE abolished the infarct size-limiting effect of SNAP ((46.0 +/- 5.1)%). Pretreatment with Zaprinast neither induced HSP72 expression nor reduced infarct size ((55.4 +/- 5.4)%).</p><p><b>CONCLUSION</b>NO induced HSP72 expression and a delayed protection to the heart via the activities of protein kinase C by a cyclic GMP-independent pathway.</p>