混配杀虫剂对美洲大蠊初孵若虫乙酰胆碱酯酶的活体in vivo抑制

研究了美洲大蠊初孵若虫乙酰胆碱酯酶（AChE）的最佳反应条件：蛋白含量40—50μg，pH7．4，底物浓度0．5mmol／L，反应温度37℃，保温时间15分钟。动力学参数Km和Vmax分别为5．64×10-4mol／L和55．5nmol／（min·mgprotein）。分析了顺式、反式氯氰菊酯与辛硫磷、马拉硫磷或毒死蜱以1：10比例混配对AChE的活体抑制。结果表明混配均能增强对AChE的抑制，其中顺式优于反式，与生测结果一致。认为拟除虫菊酯和有机磷混配增效的重要原因之一是提高了对靶标酶——AChE的抑制。

2型糖尿病并大血管病变患者血浆纤溶酶原激活物抑制剂1及凝血酶激活的纤溶抑制物水平变化及意义

目的:探讨2型糖尿病(DM)并大血管病变患者血液中纤溶酶原激活物抑制剂1(PAI-1)、血浆组织型纤溶酶原激活物(t-PA)、D-二聚体(D-D)以及血浆凝血酶激活的纤溶抑制物(TAFI)水平的变化及临床意义。方法:分别应用ELISA及乳胶免疫分析测定DM患者血浆PAI-1、t-PA、TAFI、D-D活性;并与糖尿病无大血管并发症组和健康对照组比较。结果:DM组PAI-1、t-PA、D-D和TAFI含量分别为(48.36±7.92)ng/mL、(12.52±3.17)ng/mL、(0.75±0.58)mg/L和60.82%±14.71%,与健康对照组相比有显著差异(P<0.01);其中糖尿病大血管病变组PAI-1、t-PA及D-D水平与糖尿病无大血管病变组有显著差异(P<0.01)。结论:糖尿病患者血液中PAI-1、t-PA、D-D、TAFI水平与血管损伤和功能变化的进程有显著相关性,联合检测上述指标对糖尿病及其并发症的诊断、治疗和病情观察有重要的临床意义。

miRNA studies in in vitro and in vivo activated hepatic stellate cells

AIM: To understand which and how different miRNAs are implicated in the process of hepatic stellate cell (HSC) activation. METHODS: We used microarrays to examine the differential expression of miRNAs during in vitro activation of primary HSCs (pHSCs). The transcriptome changes upon stable transfection of rno-miR-146a into an HSC cell line were studied using cDNA microarrays. Selected differentially regulated miRNAs were investigated by quantitative real-time polymerase chain reaction during in vivo HSC activation. The effect of miRNA mimics and inhibitor on the in vitro activation of pHSCs was also evaluated.RESULTS: We found that 16 miRNAs were upregulated and 26 were downregulated significantly in 10-d in vitro activated pHSCs in comparison to quiescent pHSCs. Overexpression of rno-miR-146a was characterized by marked upregulation of tissue inhibitor of metalloproteinase-3, which is implicated in the regulation of tumor necrosis factor-α activity. Differences in the regulation of selected miRNAs were observed comparing in vitro and in vivo HSC activation. Treatment with miR-26a and 29a mimics, and miR-214 inhibitor during in vitro activation of pHSCs induced significant downregulation of collagen type Ⅰ transcription. CONCLUSION: Our results emphasize the different regulation of miRNAs in in vitro and in vivo activated pHSCs. We also showed that miR-26a, 29a and 214 are involved in the regulation of collagen type I mRNA.

Long acting octreotide in the treatment of advanced hepatocellular cancer and overexpression of somatostatin receptors: Randomized placebo-controlled trial

AIM: To estimate if and to what extent long acting octreotide (LAR) improves survival and quality of life in patients with advanced hepatocellular carcinoma (HCC). METHODS: A total of 127 cirrhotics, stages A-B, due to chronic viral infections and with advanced HCC, were enrolled in the study. Scintigraphy with 111Indium labeled octreotide was performed in all cases. The patients with increased accumulation of radionuclear compound were randomized to receive either oral placebo only or octreotide/octreotide LAR only as follows: octreotide 0.5mg s.c. every 8 h for 6 wk, at the end of wk 4-8 octreotide LAR 20 mg i.m. and at the end of wk 12 and every 4 wk octreotide LAR 30mg i.m.. Follow-up was worked out monthly as well as the estimation of quality of life (QLQ-C30 questionnaire). Patients with negative somatostatin receptors (SSTR) detection were followed up in the same manner. RESULTS: Scintigraphy demonstrated SSTR in 61 patients. Thirty were randomized to receive only placebo and 31 only octreotide. A significantly higher survival time was observed for the octreotide group (49 ± 6 wk) as compared to the control group (28 ± 1 wk) and to the SSTR negative group (28 ± 2 wk), LR = 20.39, df = 2, P < 0.01. The octreotide group presented 68.5% lower hazard ratio [95% CI (47.4%-81.2%)]. During the f irst year, a 22%, 39% and 43% decrease in the QLQ-C30 score was observed in each group respectively.CONCLUSION: The proposed therapeutic approach has shown to improve the survival and quality of life in SSTR positive patients with advanced HCC.

Isolation and Purification of Triptolide from the Leaves of Tripterygium wilfordii Hook F

Triptolide is an important active component of Tripterygium wilfordii Hook F (TWHF) and possesses anti-inflammatory, immunosuppressive, male anti-fertility, and anticancer properties. A new method combining different techniques, including solid-liquid extraction, liquid-liquid partition, column chromatography and high-speed counter-current chromatography (HSCCC) but avoiding the use of chloroform, was developed for the isolation and purification of triptolide from the leaves of TWHF. 48 mg of triptolide at 96.5% purity was obtained from 1 kg of air-dried leaves of TWHF.

RELATIONSHIP BETWEEN SOMATOSTATIN RECEPTORS AND ACTIVATION OF HEPATIC STELLATE CELL

Objective To investigate the relationship between expression of somatostatin receptors(SSTRs) and activation of rat hepatic stellate cell (HSC). Methods HSCs were isolated from rats by in situ perfusion and single-step density gradient centrifugation, and then SSTR1-5 mRNA levels in the differentiated first passage HSCs were detected by means of reverse transcription polymerase chain reaction. On the other hand, hepatic fibrosis was induced in adult male Sprague-Dawley rats by carbon tetrachloride intoxication, and the expression of SSTR1-5 in normal as well as fibrotic liver was measured by immunohistochemical staining. Results SSTR mR-NA and SSTR could not be found in freshly isolated rat HSCs and normal rat liver. But SSTR1-3 mRNA appeared as HSCs became wholly activated, and SSTR1-3 could also be identified on the membrane of activated HSCs in the peri-sinusoid space, fibrous septa, etc. Conclusion The expression of SSTR1-3 in the rat HSC is closely related to its activation. This may reflect one of the main negative regulation mechanisms in the course of HSC activation.

Inhibition of the activating signals in NK92 cells by recombinant GST-sHLAG1α chain

The soluble HLA-G1 (sHLA-G1) isoform was found to be secreted by trophoblast cells at the matemo-fetal interface, which suggests that it may act as an immunomodulator during pregnancy. In this paper, we reported that GST-sHLA-G1α chain could bind to its receptor ILT-2 on NK92 cells and then the latter recruited Src homology 2 domaincontaining tyrosine phosphatase-1 (SHP-1), which consequently dephosphorylated some important protein tyrosine kinases and blocked the activation of downstream molecules such as MEK and ERK so that the cytotoxicity of natural killer (NK) cells was inhibited. These results indicated that GST-sHLA-G1α chain might be exploited in new immunotherapy strategies aiming at inducing immunotolerance during allograft, xenograft and autoimmune situations. In addition, we found that modification of O-linked β-N-acetylglucosamine (O-GlcNAc) was involved in NK cells' activating and inhibitory signals. This may provide a novel molecular target for inducing immunotolerance but needs further study.

Inhibition of Acrosomal Enzymes by Gossypol Is Related to Its Antifertility Action

To investigate into the mechanisms underlying the irreversible sterility induced by gossypol, we studied the relationship between its inhibitory action on acrosomal enzymes and its antifertility effect.As shown by our result, after exposure to gossypol (l.25-60 μg/ml) for 15 min. in vitro,the sperms' ability to penetrate bovine cervical mucus and the fertility rate were significantly reduced. Also, following administration of gossypol (12.5 mg/kg/day) for six weeks, the rate of fertilization in vitro by hamster sperm was significantly decreased. In the gossypol-treated group, extracts of testis sperm delayed dispersion of cumulus cells, suggesting inhibition of hyaluronidase and other acrosomal enzymes. Furthermore, the acrosin and arylsulfatase activities were shown to be markedly inhibited. Thus, a parallelism was displayed between the reduction of fertility and the decreasc in acrosin and arylsulfatase activities in epididymis sperms.Besides, the inhibition was reversible and was dosage-and durationdependent. In conclusion, the assay of acrosin activity might serve as a useful tool for monitoring the irreversible sterility induced by gossypol,