Oxidative stress status,caspase-3, stromal enzymes and mitochondrial respiration and swelling of <Emphasis Type="Italic">Paramecium caudatum</Emphasis> in responding to the toxicity of Fe<Subscript>3</Subscript>O<Subscript>4</Subscript> nanoparticles

The number of industrial and consumer products which contain engineered nanomaterials (ENMs, materials with at least one dimension 1–100 nm) are increasing exponentially and there is a concern regarding their occupational and environmental safety. Fe₃O₄ nanoparticles are the most widely used metal oxide nanoparticles especially, in biomedical applications. Although, nanoparticles can enter to the different organs, little is known so far on the toxicity potential and oxidative stress of Fe₃O₄. Here the understanding of the effect of Fe₃O₄ nanoparticles on the general Redox state of a unicellular protozoa Paramecium and the effect on mitochondrial swelling and respiration were assessed. Fe₃O₄ resulted in increase of toxicity markers, lipid peroxidation, protein and ROS formation. Mitochondrial enzymes and swelling were elevated with decreased respiration level. Caspase 3 activity was also increased.Finally, our study suggested that the mitochondrial disease and dysfunction with elevated oxidative stress in Paramecia treated with 200 and 300 ppm during 15 days is the original of toxicity and maybe the original cause of many environmental pathologies.     

Inhibitory activity of xanthine oxidase by fractions Crateva adansonii

ObjectiveTo study the inhibitory effect of various extracts from Crateva adansonii (C. adansonii) used traditionally against several inflammatory diseases such as rheumatism, arthritis, and gout, was investigated on purified bovine milk xanthine oxidase (XO) activity.MethodsXanthine oxidase inhibitory activity was assayed spectrophotometrically and the degree of enzyme inhibition was determined by measuring the increase in absorbance at 295 nm associated with uric acid formation. Enzyme kinetics was carried out using Lineweaver-Burk plots using xanthine as the substrate.ResultsAmong the fractions tested, the chloroform fraction exhibited highest potency (IC₅₀ 20.2±1.6 μg/mL) followed by the petroleum ether (IC₅₀ 30.1±2.2 μg/mL), ethyl acetate (IC₅₀ 43.9±1.4 μg/mL) and residual (IC₅₀ 98.0±3.3 μg/mL) fractions. The IC₅₀ value of allopurinol used, as the standard was 5.7±0.3 μg/mL.ConclusionsEnzyme inhibition mechanism indicated that the mode of inhibition was of a mixed type. Our findings suggest that the therapeutic use of these plants may be due to the observed Xanthine oxidase inhibition, thereby supporting their use in traditional folk medicine against inflammatory-related diseases, in particular, gout.     

Survival analysis of malaysian women with breast cancer: results from the university of malaya medical centre

Background: Breast cancer is the commonest cancer amongst Malaysian women but local survival data are scarce. The present study was therefore conducted to assess overall survival and prognostic factors in Malaysian breast cancer patients. Methods: The research sample was a prospective cohort of 413 patients diagnosed with breast cancer in the University of Malaya Medical Centre between 1993 to 1997. Survival data were obtained from the National Registry of Birth and Deaths in December 2000. The clinico-pathological variables studied were age, ethnic group, stage, tumour size, lymph node status, oestrogen receptor status and grade. The data were analysed utilizing Splus statistical software. The important prognostic factors were identified by fitting the Cox's proportional hazard model to the data set. Survival probabilities were estimated using the Kaplan-Meier method and differences were compared by the log-rank test. Results: The overall 5-year survival was 59.1%. The Cox's proportional hazard model identified stage, lymph node status, size and grade as factors that correlated with prognosis. Age was not a significant prognostic factor. The Cox regression model by stepwise selection showed stage, nodal status and grade of tumour to be independent prognostic factors, whereas ethnicity, age and ER status were not. Interpretation: The overall survival in our centre was low. Recognizing factors that affect prognosis of breast cancer patients in Malaysia may improve delivery of health care to at-risk groups by strategizing interventions as survival depends on early detection and effective treatment.     

骨髓干细胞分化为肝细胞的多种移植途径

近年来许多研究证实,人类和啮齿类动物的骨髓细胞可分化为多种细胞类型,包括骨骼肌细胞、心肌细胞、神经细胞和肝细胞等,这些骨髓干细胞的可塑性研究,为肝细胞移植提供了新的供体来源．骨髓干细胞替代肝细胞进行移植具有来源丰富,费用相对低廉,对患者损伤小等优点,且自体骨髓干细胞移植可以完全避免移植排斥反应,同时,骨髓干细胞只有 5-15 μm,移植后不会发生栓塞等并发症．因此骨髓干细胞移植在治疗肝病以及解决供体肝脏来源短缺方面具有广泛的应用前景．本文就骨髓干细胞的移植途径做一综述．     

五味子醇甲的代谢转化

采用动物肝微粒体体外代谢法对五味子醇甲的代谢转化进行了研究。从体外代谢产物中鉴定其主要的三个代谢物为:7,8-顺二羟基五味子酸甲;7,7-顺二羟基-2-去甲基五味子醇甲及7,8-顺二羟基-3-去甲基五味子醇甲。在此基础上,建立了生物体液中五味子醇甲及其代谢物的反相HPLC分析方法,并用此法检测了服药后大鼠的胆汁及尿样,比较了体外代谢与体内代谢的异同。     

硝基甘油对狗缺血区冠脉循环的作用

用实验性犬冠脉狭窄模型,冠脉内恒流灌注硝基甘油0.5μg/kg.min^-1,使冠脉血流量(CBF)增加、远端小动脉压(DCP)、冠脉血管总阻力(R_T)、小冠脉血管阻力(R_S)及冠状静脉低切血粘(η_b)减少;而主动脉压和心率无明显变化。恒流灌注硝基甘油1μg/kg.min^-1时,在开始5min内冠脉循环的变化同上,并伴大冠脉血管阻力(R_L)减少,10 min后出现CBF减少和R_T,R_{L及ηb增加。结果提示,硝基甘油有缓解和加重心肌缺血的双重作用,其作用可能与剂量张扩张远端小动脉压的程度有关。}     

舒他西林水解反应的研究

为指导合理用药,对舒他西林特性进行了研究。舒他西林是由氨苄西林和舒巴坦通过双酯键连接而成的口服β内酰胺抗生素前药,在中性及偏碱性条件下极易水解,水解时两个酯键的活泼性不同,通常优先形成氨苄西林和舒巴坦羟甲酯;在自发水解液中氨苄西林和舒巴坦之比约3∶1;产生的氨苄西林羟甲酯和舒巴坦羟甲酯经酯酶等进一步水解可释放出甲醛。     

用梯度反相HPLC-DAD法分离鉴别异靛甲体外代谢产物

本文报道梯度RP-HPLC-DAD法用于异靛甲未知体外代谢产物的分离鉴别。采用ODS柱,CH₃OH-H₂O(0.05%H₃PO₄)作流动相,线性梯度洗脱,代谢样品的分离过程用两个波长(270和380nm)同时检测,色谱峰光谱采集范围从220到440nm。经色谱图比较、色谱峰吸收光谱对照以及三维图鉴别,确认了异靛甲体外代谢样品中的10个代谢产物并计算了它们的相对含量。结果表明,本法分辨率高并有专属性较强的鉴定能力,只需一次进样,即可在线完成样品的分离鉴别。