ERK信号传导通路调控乙醛刺激的肝星状细胞Na+/Ca2+泵mRNA表达的研究

目的 :探讨Erk信号传导通路调控乙醛刺激的肝星状细胞 (HSC)Na /Ca2 泵mRNA表达的影响。方法 :用链霉蛋白酶和胶原酶原位灌流 ,Metrizamide密度梯度离心分离大鼠肝星状细胞 ,采用RT PCR测定PD980 5 9阻断乙醛激活的肝星状细胞Erk活性后Na /Ca2 泵mRNA表达。结果 :乙醛刺激后 ,HSC后明显促进Na /Ca2 泵mRNA表达 (P<0 0 1) ,不同剂量PD980 5 9对肝星状细胞Na /Ca2 泵mRNA表达的影响无统计学意义。结论 :Erk信号传导通路可能对乙醛刺激的肝星状细胞激活状态的启动无明显影响     

白色念珠菌感染与口腔癌的关系

口腔癌是头颈部最常见的癌症之一,严重影响患者生存质量和生活水平。白色念珠菌是口腔中最常见的机会性致病真菌,当宿主免疫功能低下时表现出致病性,容易引起念珠菌感染。近年来研究发现白色念珠菌感染与口腔癌关系密切,本文对口腔癌患者白色念珠菌感染的流行病学特点,以及白色念珠菌感染对口腔癌发生发展的影响及其机制研究进行综述。通过回顾相关文献发现:口腔癌患者白色念珠菌感染风险增加,白色念珠菌感染可能通过损伤口腔上皮、产生致癌物质、触发慢性炎症及辅助性T细胞17免疫反应等机制促进口腔癌的发生发展。然而目前这些机制的研究仍比较表浅,缺乏充足的直接证据,未来仍需进行大量研究,以期进一步明确白色念珠菌的促癌机制,为防治口腔癌提供新思路。     

Fermentative 2‐carbon metabolism produces carcinogenic levels of acetaldehyde in Candida albicans

Acetaldehyde is a carcinogenic product of alcohol fermentation and metabolism in microbes associated with cancers of the upper digestive tract. In yeast acetaldehyde is a by‐product of the pyruvate bypass that converts pyruvate into acetyl‐Coenzyme A (CoA) during fermentation. The aims of our study were: (i) to determine the levels of acetaldehyde produced by Candida albicans in the presence of glucose in low oxygen tension in vitro; (ii) to analyse the expression levels of genes involved in the pyruvate‐bypass and acetaldehyde production; and (iii) to analyse whether any correlations exist between acetaldehyde levels, alcohol dehydrogenase enzyme activity or expression of the genes involved in the pyruvate‐bypass. Candida albicans strains were isolated from patients with oral squamous cell carcinoma (n = 5), autoimmune polyendocrinopathy–candidiasis–ectodermal dystrophy (APECED) patients with chronic oral candidosis (n = 5), and control patients (n = 5). The acetaldehyde and ethanol production by these isolates grown under low oxygen tension in the presence of glucose was determined, and the expression of alcohol dehydrogenase (ADH1 and ADH2), pyruvate decarboxylase (PDC11), aldehyde dehydrogenase (ALD6) and acetyl‐CoA synthetase (ACS1 and ACS2) and Adh enzyme activity were analysed. The C. albicans isolates produced high levels of acetaldehyde from glucose under low oxygen tension. The acetaldehyde levels did not correlate with the expression of ADH1, ADH2 or PDC11 but correlated with the expression of down‐stream genes ALD6 and ACS1. Significant differences in the gene expressions were measured between strains isolated from different patient groups. Under low oxygen tension ALD6 and ACS1, instead of ADH1 or ADH2, appear the most reliable indicators of candidal acetaldehyde production from glucose.     

Bcl‐2 overexpression in hepatic stellate cell line CFSC‐2G,induces a pro‐fibrotic state

Background and Aim: Development of hepatic fibrosis is a complex process that involves oxidative stress (OS) and an altered balance between pro‐ and anti‐apoptotic molecules. Since Bcl‐2 overexpression preserves viability against OS, our objective was to address the effect of Bcl‐2 overexpression in the hepatic stellate cells (HSC) cell‐line CFSC‐2G under acetaldehyde and H₂O₂ challenge, and explore if it protects these cells against OS, induces replicative senescence and/or modify extracellular matrix (ECM) remodeling potential. Methods: To induce Bcl‐2 overexpression, HSC cell line CFSC‐2G was transfected by lipofection technique. Green fluorescent protein‐only CFSC‐2G cells were used as a control. Cell survival after H₂O₂ treatment and total protein oxidation were assessed. To determine cell cycle arrest, proliferation‐rate, DNA synthesis and senescence were assessed. Matrix metalloproteinases (MMP), tissue‐inhibitor of MMP (TIMP), transglutaminases (TG) and smooth muscle a‐actin (α‐SMA) were evaluated by western blot in response to acetaldehyde treatment as markers of ECM remodeling capacity in addition to transforming growth factor‐β (TGF‐β) mRNA. Results: Cells overexpressing Bcl‐2 survived ≈ 20% more than control cells when exposed to H₂O₂ and ≈ 35% proteins were protected from oxidation, but Bcl‐2 did not slow proliferation or induced senescence. Bcl‐2 overexpression did not change α‐SMA levels, but it increased TIMP‐1 (55%), tissue transglutaminases (tTG) (25%) and TGF‐β mRNA (49%), when exposed to acetaldehyde, while MMP‐13 content decreased (47%). Conclusions: Bcl‐2 overexpression protected HSC against oxidative stress but it did not induce replicative senescence. It increased TIMP‐1, tTG and TGF‐β mRNA levels and decreased MMP‐13 content, suggesting that Bcl‐2 overexpression may play a key role in the progression of fibrosis in chronic liver diseases.     

紫外二阶导数光谱标准加入法测定中药复方制剂中合成鱼腥草素含量

将紫外二阶导数光谱与标准加入法相结合应用于药物分析，定量测定中药复方制剂中合成鱼腥草素的含量。根据比尔定律推导出标准加入体系的含量计算公式为Ｘ＿ｉ＝Ｘ＿ｉ×Ｃ＿ｉ／Ｋ－Ｃ＿ｉ×Ｖ＿ｉ。方法精密度ＣＶ１．３％；平均回收率９９．４０％，回收率ＣＶ１．９％。本法消除了中药复方制剂中样品基质的干扰，结果准确可靠。     

Effects on Rat Liver Acetaldehyde Dehydrogenases in Vitro and in Vivo by Coprine,the Disulfiram-like Constituent of Coprinus atramentarius

Abstract Coprine, the disulfiram-like constituent of the mushroom Coprinus atramentarius was found to inhibit the low-K_m acetaldehyde dehydrogenase in rat liver and to increase the acetaldehyde level in blood during ethanol metabolism in vivo. Coprine did not inhibit the low-K_m enzyme in vitro, but the hydrolytic product of coprine, 1 -aminocyclo-propanol, was a potent inhibitor both in vitro and in vivo. A rapid onset of inhibition was observed after administration of coprine and the inhibition was long-lasting. It is suggested that 1-aminocyclo-propanol is responsible for the inhibition caused by coprine in vivo.     

Chronic ethanol consumption impairs receptor-mediated endocytosis of MAA-modified albumin by liver endothelial cells

Alcoholic liver disease has been associated with abnormalities in receptor-mediated endocytosis (RME) which results in abnormal degradation of metabolically altered proteins. Model systems using formaldehyde-modified albumin (f-Alb) have shown an impairment in RME following chronic alcohol consumption utilizing both in situ perfused rat livers and isolated rat liver endothelial cells (LECs). The discovery that alcohol metabolite derived aldehydes can modify proteins prompted a study to determine if malondialdehyde-acetaldehyde-modified albumin (MAA-Alb) would be degraded similar to that reported for f-Alb, and whether ethanol-fed rats would demonstrate an impaired RME with respect to this ligand which occurs as a consequence of chronic ethanol consumption. MAA-Alb was degraded slightly more than f-Alb in both in situ perfused livers and at the single cell level. This degradation was completely inhibited with 100x unlabeled f-Alb, which suggests the use of a similar receptor. Following alcohol consumption there was a 50-60% decrease in MAA-Alb degradation in whole livers and isolated LECs. Utilizing isolated LECs it was determined that impairment in internalization was the most likely mechanism for the decrease in the amount of MAA-Alb that was degraded. These data show that chronic alcohol consumption by rats does in fact impair RME of alcohol metabolite-derived adducted proteins, and this impairment is due to a defect in the post-internalization step rather than the binding or degradation of the modified protein.     

鱼腥草素β-环糊精包合物的研究

 目的:研究鱼腥草素β-环糊精包合物的制备方法及包合前后鱼腥草素物理性能变化?方法:采用研磨法制备鱼腥草素β-环糊精包合物,含量测定方法是将鱼腥草素与铜(Ⅱ)于氨性介质中形成鳌合物,于(300±1)nm波长处测定螯合物氯仿提取液吸光度,测定了包合物及鱼腥草素的溶解度、溶出速度,比较了二者X-射线衍射图谱、紫外吸收光谱变化及其在水中溶解稳定性?结果:鱼腥草素β-环糊精包合物的主客分子比为1∶1,包合后,鱼腥草素的溶解度增大了11.4倍,鱼腥草素及包合物的溶出速度参数T_50%分别为1.7,1.0min,Td分别为3.0,1.4min,二者紫外吸收光谱完全一致,包合后鱼腥草素的晶体衍射峰消失。结论:鱼腥草素与β-环糊精形成了新的物相,包合后,鱼腥草素溶解度、溶出速度及稳定性增强,并可掩盖其不良气味。     

Nasal lavage mediator profile and cellular composition of nasal brushing material during latex challenge tests

BACKGROUND: Recent studies have shown that airborne latex allergens cause allergic rhinitis and bronchial asthma. OBJECTIVE: The aim of this study was to investigate the association between the development of rhinitis reactions during workplace-related inhalative challenge tests and nasal allergic inflammation. METHODS: Thirty-two health care workers (HCWs) with suspected respiratory hypersensitivity to latex allergens underwent an inhalative workplace-related challenge test with powdered latex gloves. Nasal lavage fluid (NALF) and nasal brushing (NAB) material were collected before and after exposure (30 min, 2, 6 and 24 h) to determine mediator and cellular composition. In addition, lung function parameters and nasal flow were recorded. Furthermore, six healthy controls underwent nasal brushing and nasal lavage without latex allergen challenge at the same time intervals. RESULTS: Twenty-six HCWs showed acute rhinitis by contact to airborne latex allergen exposure and 10 of them had an additional asthma response. Only in responders, significantly increased eosinophil levels were found 6 h (P < 0.00001) and 24 h (P < 0.0005) post-challenge when compared with the prechallenge values. The ECP levels measured 2, 6 and 24 h post-challenge in the responder group were significantly elevated when compared with the prechallenge values as well as with the non-responders (6 h: P < 0.05, 24 h: P < 0.00001 afterwards). Only in some concentrated NALF samples of responders collected 30 min post-challenge (seven out of 15) tryptase concentration above the detection limit were found. The NO derivative concentrations in NALF were significantly increased 6 h post-challenge compared with the prechallenge values (P < 0.05) and were significantly higher in responders than in non-responders and in controls (P < 0.002). IL-5 levels increased post-challenge in the responder group with a pronounced effect 6 h after challenge (P < 0.001). Overall, a variety of parameters was significantly correlated (e.g. ECP with NO derivatives, r = 0.792 P < 0.002). CONCLUSIONS: Our data demonstrate for the first time that nasal and bronchial hyperreactivity to airborne latex allergens are associated with an increase of eosinophils and mediators (e.g. ECP, NO derivatives, IL-5, tryptase) in nasal mucosa. The combined use of NAB (for cells) and NALF (for mediators) appears to be a useful model to monitor nasal inflammation during workplace-related challenge tests.