质子泵抑制剂对非甾体抗炎药相关胃肠疾病的疗效:荟萃分析

质子泵抑制剂(PPI)广泛应用于非甾体抗炎药(NSAIDs)相关胃肠疾病的治疗,但其疗效缺乏相关循证医学资料证实。目的:评价PPI治疗NSAIDs相关胃肠疾病的疗效。方法:通过Medline和中国生物医学文献数据库检索1979～2005年10月发表的有关PPI治疗NSAIDs相关胃肠疾病的单中心或多中心随机对照临床试验。根据入选标准,共有6项临床试验纳入本研究。由2名作者各自独立地对入选研究中的试验设计、研究对象特征、研究结果等内容进行摘录。应用RevMan4.2软件,以随机效应模型进行荟萃分析。结果:6项随机临床试验中共2280例患者满足纳入标准。荟萃分析结果显示:PPI与安慰剂相比,RR为1.33,95%CI为1.00～1.76,P=0.05;PPI与胶体铋相比,RR为0.99,95%CI为0.85～1.17,P=0.95;PPI与H2受体拮抗剂(H2RA)相比,RR为1.26,95%CI为1.08～1.46,P=0.002。但PPI与安慰剂相比和PPI与胶体铋相比均存在异质性。结论:PPI在不停用NSAIDs的情况下仍能有效缓解NSAIDs引起的胃肠道损害,其疗效优于H2RA,但与胶体铋相比并无明显优势。

MTT法检测灰直纹螟-青钱柳虫茶对肿瘤细胞体外增殖抑制作用

为了获得优质的灰直纹螟-青钱柳虫茶以及明确其对人乳腺癌细胞MCF-7、胃癌细胞SGC-7901增殖抑制作用。用青钱柳叶片饲养灰直纹螟后,将其幼虫所排出的代谢物经过不同规格筛网筛选分离和紫外杀菌后获得优质虫茶,将获得的虫茶制备成不同浓度去处理体外培养的MCF-7和SGC-7901癌细胞,采用MTT法检测虫茶体外对MCF-7和SGC-7901癌细胞的增殖抑制作用。结果表明,灰直纹螟-青钱柳虫茶对人乳腺癌细胞MCF-7和胃癌细胞SGC-7901具有明显的抑制作用,但抑制效果并不完全相同,处理24 h后虫茶对人乳腺癌细胞MCF-7的增殖抑制效果更好。虫茶对人乳腺癌细胞MCF-7、胃癌细胞SGC-7901具有明显的抑制作用,其抑制率与浓度及处理时间呈正相关。

乙酰胆碱酯酶抑制剂的研究进展

老年痴呆(AD)是老年人较为常见的神经衰退性疾病。治疗药物用乙酰胆碱酯酶(AChE)抑制剂。本文介绍AChE的结构及研究进展。

芳香化酶抑制剂治疗生精障碍的应用现状

芳香化酶(aromatase)是雄激素向雌激素生物转化关键步骤的限速酶,其活性增强会导致男性体内雄激素过度向雌激素转化,进而损害睾丸的生精功能,造成生精障碍。患者可表现为少精子症、严重少精子症或非梗阻性无精子症。芳香化酶抑制剂(aromatase inhibitor,AI)可以抑制芳香化酶活性,阻断雄激素向雌激素的转化,从而改善部分生精障碍患者的睾丸生精功能。目前AI用于治疗生精障碍受到越来越多的关注。现将AI治疗生精障碍的应用现状作一综述。

非核苷类逆转录酶抑制剂的研究进展

目的综述非核苷类逆转录酶抑制剂(NNRTIs)的研究进展。方法对近年来国内外有关文献资料进行分析评述。结果与结论目前有3种非核苷类逆转录酶抑制剂已用于临床治疗,还有多种化合物处于临床试验阶段,有望成为新的治疗药物, 对各类非核苷类逆转录酶抑制剂的构效关系的研究为新的药物发现提供了基础。

p-q-r法在三相四线制谐波抑制中的应用

分析了p q r法在电力系统谐波检测中的应用。详细讨论了三相四线制中电压有畸变和负载不对称时中线电流的抑制效果,从HyosungKim提出的p q r法的基本理论出发,通过理论分析和仿真证明p q r法在电压畸变明显时不能完全抑制谐波,而对无功补偿和中线电流抑制有较好的效果。

取向硅钢生产工艺技术分析和发展趋势

介绍了普通取向硅钢(CGO)和高磁感取向硅钢(Hi-B)铸坯高温加热两次冷轧、一次冷轧和铸坯低温加热两次冷轧、一次冷轧法4种成熟生产工艺的主要技术参数,取向硅钢理论研究(Goss晶核和抑制剂)和生产技术现状。取向钢的发展趋势为:提高(110)[001]晶粒取向度,降低取向硅钢铁损,发展铸坯低温加热(≤1 300℃)和薄板坯连铸连轧流程生产取向硅钢工艺。

Effects of Drought Stress on the Photoprotection in Ammopiptanthus mongolicus Leaves

Ammopiptanthus mongolicus (Maxim.) Cheng f. is one of the evergreen shrubs in the desert region of China. In midday its leaves bear photon flux density over 1 500 μmol·m -2 ·s -1 at natural habitat. They show the obvious phenomenon of photoinhibition. For the study of the effects of drought stress on the major protective mechanism against strong light in A. mongolicus leaves, the diurnal variations of photosynthetic rate and chlorophyll fluorescence parameters were investigated under natural conditions with portable photosynthetic measurement system (CIRAS_1) and portable fluorometer (MFMS_2). The experimental results showed that, under normal and drought stress conditions,the net photosynthetic rate ( Pn ), the primary maximum photochemical efficiency of PSⅡ ( Fv/Fm ) and the quantum efficiency of noncyclic electron transport of PSⅡ ( Φ PSⅡ ) decreased obviously at noon (Figs.2,3A,4B). In comparison with plants under normal condition, under drought stress minimal chlorophyll fluorescence ( Fo ) decreased at first and then increased (Fig.3A), non_photochemical quenching ( NPQ ) quickly increased and sustained at a higher level (Fig.4B). This indicated that the major photoprotective mechanism of A. mongolicus leaves was the xanthophyll cycle_dependent thermal energy dissipation under normal condition, while under drought stress, the major photoprotective mechanism was both the xanthophyll cycle_dependent thermal energy dissipation and the reversible inactivation of PSⅡ reaction center.

社会公众的环境关注与污染密集型企业的区位选择

基于“需求抑制”和“规制抑制”两条路径,考察自下而上的公众环境关注如何影响污染密集型企业的区位选择策略。采用百度搜索指数及“天眼查”企业登记平台获取大数据信息,通过对2011—2018年中国285个城市的考察发现,公众环境关注对污染密集型企业区位选择具有本地抑制效应和邻地溢出效应。其主要原因在于公众环境关注单纯依靠“规制抑制”路径,通过倒逼地方政府加大环境规制力度减少污染密集型企业的本地进入,而公众自身却没有将对环境议题的关注转化为对污染品的“需求抑制”。由于市场需求的存在,相关企业不愿过分远离高环境关注城市,最终选择在与之相邻的周边城市投资建厂。从研究视角、数据获取、作用路径异质性与邻地溢出存在性等维度对污染企业区位选择研究进行的拓展,强调了将公众环境意识转化为环保行为,最终从消费端进行污染治理的重要性。

Research Advances in the Inhibition of Long Chain Fatty Acid to Methanogenic Activity in Anaeroic Digestion System

This article reviewed the inhibition mechanism of long chain fatty acid on the formation of anaerobic system, then thoroughly analyzed the inhibition factors of long chain fatty acid, and summarized the remission method to its inhibition, finally proposed some suggestions to further study on the influence of long chain fatty acid on anaerobic digestion system.

Effect of New Immunosuppressant-Rapamycin on One-way Mixed Lymphocyte Culture

Objective: Observing human to mouse one-way mixed lymphocyte culture(xMLC) and the effect of new immunosuppressant-Rapamycin on XMLC. Methods: Mouse splenic lymphocyte were collected and treated by mitomycin as activating cell; Human Peripheral blood lymphocytes(hPBL)were separated and gathered as reacting cell; Mouse splenic lymphocyte and hPBL wee mixed to incubate for 1 week; The researchers designed control、RPM groups,and experiment(drugs)grup have different concentration. Results: HPBL in the experiment groups (mixed mouse lymphocyte)proliferated obviously,the amount of3H-TdR in corporation increased evidently(P<0 05,The mean percentage of CD 4, CD 8, LgG, LgM positive cells rose markedly. HPBL in the experiment groups less proliferated,the amount of 3H-TdR incorporation declined,RPM's ic50(50%inhibition concentration)approximately in 1.5 nmol/L; the mean percentage of CD 4, CD 8, IgG, IgM positive cells fell obviously. Conclusion: The human to mouse one-way MLC has obvious lymphocyte proliferation. New immunosuppressants-Rapamycin have powerful effete on XMLC.

Composite control for coagulation process with time delay and disturbances

A composite control scheme consisting of modepredictive control （MPC） and disturbance observer （DOB） iproposed to solve the control performance degradationproblem of the turbidity of the treated water in the presence osignificant changes in raw water quality, water flow rate andinternal model mismatch disturbances. The MPC is employedas a feedback controller for the coagulation process with alarge time delay. The DOB is adopted to estimate the severedisturbances in the turbidity control, such as large changes inraw water quality and water flow rate. The estimated valuesare applied for feed-forward compensation to rejecdisturbances. Finally, the disturbance rejection performancesfor step disturbances and time-varying disturbances in thenominal case and model mismatch case are tested. Thesimulation results illustrate that, compared with the MPCmethod, the proposed method can significantly improve thedisturbance rejection performance in the turbidity control othe treated water, no matter if in the presence of externadisturbances or internal model mismatch disturbances.

Roles of TGFβ in metastasis

The TGFβ signaling pathway is conserved from flies to humans and has been shown to regulate such diverse pro- cesses as cell proliferation, differentiation, motility, adhesion, organization, and programmed cell death. Both in vitro and in vivo experiments suggest that TGF[~ can utilize these varied programs to promote cancer metastasis through its effects on the tumor microenvironment, enhanced invasive properties, and inhibition of immune cell function. Recent clinical evidence demonstrating a link between TGFβ signaling and cancer progression is fostering interest in this signaling pathway as a therapeutic target. Anti-TGFβ therapies are currently being developed and tested in pre- clinical studies. However, targeting TGFβ carries a substantial risk as this pathway is implicated in multiple homeostatic processes and is also known to have tumor-suppressor functions. Additionally, clinical and experimental results show that TGFβ has diverse and often conflicting roles in tumor progression even within the same tumor types. The development of TGFβ inhibitors for clinical use will require a deeper understanding of TGFβ signaling, its consequences, and the contexts in which it acts.

Abnormal endogenous pain modulation and somatic and visceral hypersensitivity in female patients with irritable bowel syndrome

AIM： To investigate the role of endogenous pain modulatory mechanisms in the central sensitization implicated by the visceral hypersensitivity demonstrated in patients with irritable bowel syndrome （IBS）. Dysfunction of modulatory mechanisms would be expected to also result in changes of somatic sensory function. METHODS： Endogenous pain modulatory mechanisms were assessed using heterotopic stimulation and somatic and visceral sensory testing in IBS. Pain intensities （visual analogue scale, VAS 0-100） during suprathreshold rectal distension with a barostat, cold pressor stimulation of the foot and during both stimuli simultaneously （heterotopic stimulation） were recorded in 40 female patients with IBS and 20 female healthy controls. RESULTS： Rectal hypersensitivity （defined by 95% Cl of controls） was seen in 21 （53%）, somatic hypersensitivity in 22 （55%） and both rectal and somatic hypersensitivity in 14 of these IBS patients. Heterotopic stimulation decreased rectal pain intensity by 6 （-11 to -1） in controls, but increased rectal pain by 2 （-3 to ＋6） in all IBS patients （P 〈 0.05） and by 8 （-2 to ＋19） in IBS patients with somatic and visceral hypersensitivity （P 〈 0.02）. CONCLUSION： A majority of IBS patients had abnormal endogenous pain modulation and somatic hypersensitivity as evidence of central sensitization.

Mesenchymal stem cells： a new strategy for immunosuppression and tissue repair

Mesenchymal stem cells （MSCs） have great potential for treating various diseases, especially those related to tissue damage involving immune reactions. Various studies have demonstrated that MSCs are strongly immunosuppressive in vitro and in vivo. Our recent studies have shown that un-stimulated MSCs are indeed incapable of immunosuppression; they become potently immunosuppressive upon stimulation with the supernatant of activated lymphocytes, or with combinations of IFN-γ, with TNF-α, IL-1α or IL-1β. This observation revealed that under certain circumstances, inflammatory cytokines can actually become immunosuppressive. We showed that there is a species variation in the mechanisms of MSC-mediated immunosuppression： immunosuppression by cytokine-primed mouse MSCs is mediated by nitric oxide （NO）, whereas immunosuppression by cytokine-primed human MSCs is executed through indoleamine 2, 3-dioxygenase （IDO）. Additionally, upon stimulation with the inflammatory cytokines, both mouse and human MSCs secrete several leukocyte chemokines that apparently serve to attract immune cells into the proximity with MSCs, where NO or IDO is predicted to be most active. Therefore, immunosuppression by inflammatory cytokine-stimulated MSCs occurs via the concerted action of chemokines and immune-inhibitory NO or IDO produced by MSCs. Thus, our results provide novel information about the mechanisms of MSC-mediated immunosuppression and for better application of MSCs in treating tissue injuries induced by immune responses.

Downregulation of survivin by RNAi inhibits growth of human gastric carcinoma cells

AIM: To investigate the inhibitory effect of a specific small survivin interfering RNA (siRNA) on cell proliferation and the expression of survivin in human gastric carcinoma cell line SGC-7901. METHODS: To knockdown survivin expression, a small interfering RNA targeting against survivin was synthesized and transfected into SGC-7901 cells with lipofectamineTM2000. The downregulation of survivin expression at both mRNA and protein levels were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. Cell proliferation inhibition rates were determined by methyl thiazolyl tetrazolium (MTT) assay. The effect of survivin siRNA on cell cycle distribution and cell apoptosis was determined by flow cytometry (FCM). RESULTS: RNA interference could efficiently suppress the survivin expression in SGC-7901 cells. At 48 h after transfection, the expression inhibition rate was 44.52% at mRNA level detected by RT-PCR and 40.17% at protein level by Western blot analysis. Downregulation of survivin resulted in significant inhibition of tumor cell growth in vitro. The cell proliferation inhibition rates at 24, 48 and 72 h after survivin siRNA and non-siliencing siRNA transfection, were 34.06%, 47.61% and 40.36%, respectively. The apoptosis rate was 3.56% and the number of cells was increased in G0/G1 phase from 38.2% to 88.6%, and decreased in S and G2/M phase at 48 h after transfection. CONCLUSION: Downregulation of survivin results in significant inhibition of tumor growth in vitro. The inhibition of survivin expression can induce apoptosis of SGC-7901 cells. The use of survivin siRNA deserves further investigation as a novel approach to cancer therapy.

Active disturbance rejection control for hydraulic width control system for rough mill

The highly nonlinear behavior of the system limits the performance of classical linear proportional and integral （PI） controllers used for hot rolling. An active disturbance rejection controller is proposed in this paper to deal with the nonlinear problem of hydraulic servo system in order to preserve last response and small overshoot of control system. The active disturbance rejection （ADR） controller is composed of nonlinear tracking differentiator （TD）, extended state observer （ESO） and nonlinear feedback （NF） law. An example of the hydraulic edger system case study is investigated to show the effectiveness and robustness of the proposed nonlinear controller, especially, in the circumstance of foreign disturbance and working condition variation, compared with classic PI controller.

KN-93,a specific inhibitor of CaMKⅡ inhibits human hepatic stellate cell proliferation in vitro

AIM： To investigate the effects of KN-93, a CaMKⅡ selective inhibitor on cell proliferation and the expression of p53 or p21 protein in human hepatic stellate cells. METHODS： Human hepatic stellate cells （LX-2） were incubated with various concentrations （0-50 μmol/L） of KN-93 or its inactive derivative, KN-92. Cell proliferation was measured by CCK-8 assay, and the expression of two cell cycle regulators, p53 and p21, was determined by SDS-PAGE and Western blotting. RESULTS： KN-93 （5-50 μmol/L） decreased the proliferation of human hepatic stellate cells in a dosedependent manner from 81.76% （81.76% ± 2.58% vs 96.63% ± 2.69%, P 〈 0.05） to 27.15% （27.15% ± 2.86% vs 96.59% ± 2.44%, P 〈 0.01） after 24 h treatment. Incubation of 10 μmol/L KN-93 induced the cell growth reduction in a time-dependent manner from 78.27% at 8 h to 11.48% at 48 h. However, KN-92, an inactive derivative of KN-93, did not inhibit cell proliferation effectively. Moreover, analysis of cell cycle regulator expression revealed that KN-93 rather than KN-92 reduced the expression of p53 and p21. CONCLUSION： KN-93 has potent inhibitory effect on proliferation of LX-2 cells by modulating the expression of two special cell cycle regulators, p53 and p21.