Identification of Candida species in the clinical laboratory: a review of conventional,commercial, and molecular techniques

In healthy individuals, Candida species are considered commensal yeasts of the oral cavity. However, these microorganisms can also act as opportunist pathogens, particularly the so‐called non‐albicans Candida species that are increasingly recognized as important agents of human infection. Several surveys have documented increased rates of C. glabrata, C. tropicalis, C. guilliermondii, C. dubliniensis, C. parapsilosis, and C. krusei in local and systemic fungal infections. Some of these species are resistant to antifungal agents. Consequently, rapid and correct identification of species can play an important role in the management of candidiasis. Conventional methods for identification of Candida species are based on morphological and physiological attributes. However, accurate identification of all isolates from clinical samples is often complex and time‐consuming. Hence, several manual and automated rapid commercial systems for identifying these organisms have been developed, some of which may have significant sensitivity issues. To overcome these limitations, newer molecular typing techniques have been developed that allow accurate and rapid identification of Candida species. This study reviewed the current state of identification methods for yeasts, particularly Candida species.     

认知矫正治疗对慢性精神分裂症患者临床症状和社会功能的影响

目的:观察认知矫正治疗对慢性精神分裂症患者临床症状和社会功能的改善作用。方法:选择2003-01/08在北京回龙观医院住院的慢性精神分裂症患者104例。均符合CCMD-Ⅲ及DSM-Ⅳ关于精神分裂症诊断标准;年龄25～55岁;病程≥2年;病情稳定,处于迁延、残留或部分缓解状态;药物治疗状况稳定,近期无换药打算;纳入对象或家属同意入组并签署知情同意书。应用随机数字表法将患者分认知矫正治疗组和对照组,每组52例。在相近药物治疗的基础上,认知矫正治疗组以Ann Delahunty和Rodney Morice等制定的神经认知矫正手册(汉化)为治疗工具,在治疗师的指导下进行认知作业练习,内容包括认知灵活性、工作记忆、计划执行功能3大功能模块。对照组予以相同时间的工娱治疗,主要包括有治疗师指导的操作性音乐治疗和舞蹈治疗。治疗前后两组患者分别进行PANSS、住院精神患者社会功能缺陷量表和护士观察量表的评定。结果:实验共纳入慢性精神分裂症患者104例,认知矫正治疗组44例,对照组46例进入结果分析,14例脱落。①治疗前后两组患者PANSS量表总分以及阴性症状量表、复合量表、一般精神病理量表、反应缺乏量表4个分量表的评分均有下降,组内比较差异有显著性意义(t=2.12～4.59,P<0.05);减分情况在两组间差异不明显(P>0.05)。②两组患者的社会功能缺陷量表总分在治疗后均有下降,与治疗前比较,差异有显著性意义(t=3.89,2.04,P<0.05);两组间比较,差异无显著性意义(P>0.05)。认知矫正治疗组治疗后护士观察量表的总病情以及总消极、迟滞2个分量表评分下降,与治疗前比较差异有显著性意义(t=1.49,1.19,2.81,P<0.05);其中迟滞项的减分在两组间比较,差异具有显著性意义(F=4.97,P<0.05)。③社会功能量表的改善与词语流畅性的改善呈正相关(R2=0.36,P<0.05),护士观察量表中总病情与积极两项评分的改善也与言语流畅性测验的改善正相关(R2=0.37,0.34,P<0.05)。结论:认知矫正治疗能在一定程度上改善精神分裂症患者的社会功能,并与部分认知功能的改善相关,但对临床症状无明显改善作用。     

白细胞介素1及白细胞介素8在心肌缺血再灌注损伤中的动态演变及药物干预效果

目的:在心肌缺血再灌注损伤中,炎症细胞因子参与其过程的多个环节。实验拟验证白细胞介素1、白细胞介素8因子在此过程中的动态变化,并分析其与药物干预的关系。方法:实验于2005-10/2006-11在新乡医学院形态学实验室完成。①实验分组:选择健康Wistar成年大鼠70只,按随机数字表法分为3组:对照组(n=10)、模型组(n=30)和药物组(n=30)。后两组又分为缺血0.5h,再灌注2,4,8,12,24h6个时相点,每个时相点5只。对照组只设12h一个时相点作为总体对照。②实验方法:大鼠麻醉后,药物组在右股静脉注入甲泼尼龙(30mg/kg),对照组及模型组注入生理盐水(0.75mg/kg)。采用夹闭左冠状动脉前降支建立大鼠心肌缺血再灌注损伤模型。对照组只开胸不夹闭。③实验评估:在各时相点观察各组大鼠缺血再灌注后的心肌细胞改变;血清学检测白细胞介素1、白细胞介素8因子的动态表达。结果:①模型组缺血再灌注12h炎细胞浸润最显著,药物组炎细胞呈散在浸润。②模型组和药物组白细胞介素1、白细胞介素8因子质量浓度明显高于对照组[缺血再灌注8h为例,白细胞介素1分别为(99.21±14.37),(85.77±11.31),(21.87±10.32)ng/L;白细胞介素8分别为(794.85±24.07),(536.95±19.72),(103.94±11.59)ng/L,P<0.05],峰值分别在缺血再灌注4,8h;同时相点药物组白细胞介素1、白细胞介素8因子质量浓度明显低于模型组(P<0.05)。结论:白细胞介素1和白细胞介素8因子在心肌缺血再灌注损伤的炎症反应中发挥着重要作用;甲泼尼龙对缺血再灌注损伤心肌有保护作用。     

脑源性神经生长因子促进成年大鼠脑海马神经干细胞定向分化的浓度选择

目的：探讨培养基中表皮生长因子与血清两者浓度一定的条件下，不同浓度的脑源性神经生长因子对成年大鼠脑海马神经干细胞向神经元分化的影响。 方法：实验于2007—08在中国医科大学神经解剖研究室完成。①材料：清洁级雄性成年SD大鼠1只，由中国医科大学实验动物部提供，实验过程中对动物的处置符合动物伦理学标准。实验过程中应用的表皮生长因子、脑源性神经生长因子均由R＆D公司提供：（多实验方法：无菌条件下分离大鼠脑海马组织，剪碎后胰蛋白酶消化，过滤、离心、弃上清，加入含2％B27、20μg／L表皮生长因子、20μg／L碱性成纤维生长因子的DMEM／F12无血清条件培养基体外培养神经干细胞，传至第4代时利用有限稀释法进行单克隆培养，100倍镜下克隆球直径约为200μm时制备单细胞悬液，稀释后滴加于96孔板内，设立两组，全量新鲜培养基组加入刚配置未使用过的DMEM／F12无血清培养基100μL，半量条件培养基组加入上述曾用于神经干细胞培养且含有其代谢产物的1／2DMEM／F12无血清培养基100斗L。（劲实验评估：观察神经干细胞的单克隆培养增殖情况。对克隆球行巢蛋白、神经元特异性烯醇化酶、胶质原纤维酸性蛋白免疫细胞化学染色。按培养基中脑源性神经生长因子终浓度的不同将所培养细胞设立0，50，100，150，200μg／L组，各组均加入20μg／L表皮生长因子和体积分数为0．1的胎牛血清，1周后行神经元特异性烯醇化酶免疫细胞化学染色，检测神经干细胞向神经元分化情况。 结果：①神经干细胞单克隆培养结果：单克隆培养开始时神经干细胞增殖缓慢，半量条件培养基组细胞增殖速度快于全量新鲜培养基组，随着细胞数的增多，两组细胞增殖速度也相应加快，分别在培养后第12天、第15天形成直径为200μm的克隆球。②神经干细胞免疫细胞化学染色结果：单克隆培养后克隆球表达巢蛋白，诱导分化后神经元特异性烯醇化酶、胶质原纤维酸性蛋白均呈阳性表达：③各组神经干细胞分化为神经元的比例：与0μg／L脑源性神经生长因子组比较，50，100μg／L脑源性神经生长因子组的神经干细胞分化为神经元比例均明显增高（t=2．502～5．025，P〈0．05）；而浓度为150，200μg／L时均无明显变化（t=0．420～1．857，P〉0．05）。 结论：向含有B27、表皮生长因子、碱·性成纤维生长因子的DMEM／F12条件培养基中加入20μg／L表皮生长因子和体积分数为0．1胎牛血清的情况下，脑源性神经生长因子促使神经干细胞向神经元分化的较佳浓度为50μg／L。     

瘢痕疙瘩家系Fas基因的突变：2个家系10份标本分析

目的:观察瘢痕疙瘩家系样本中Fas基因有无突变,探讨Fas基因突变在瘢痕疙瘩形成中的意义。方法:实验于2005-01/05在上海基康公司完成。①标本来自南方医科大学南方医院整形外科2005年收集的A和B两个瘢痕疙瘩家系,所有参与观察的家系成员均签署知情同意书。②采用聚合酶链反应及基因测序技术,分别以A家系两例患者的瘢痕疙瘩组织为观察对象,以其周围正常皮肤及外周静脉血作为自身对照;其配偶的外周静脉血作为正常对照。并以B家系中两例患者的外周静脉血作为不同家系间的对照。共取10份样本,4份组织样本,6份静脉血标本。检测10份样本中Fas基因外显子1～9的基因序列。结果:①基因测序发现所检测的10个瘢痕疙瘩家系标本Fas基因的1～8外显子均未发现突变。②2份瘢痕疙瘩组织标本在第9外显子编码区的11bp,53bp两个位点上存在单个碱基的基因突变或多态性改变。结论:瘢痕疙瘩Fas基因外显子9区段的基因结构异常极有可能造成Fas蛋白的功能改变,从而导致身体局部瘢痕疙瘩的形成。     

转化生长因子β1在白细胞介素1β诱导大鼠肾小管上皮细胞转分化及大黄素干预中的作用

目的:大黄素对白细胞介素1β诱导NRK52E细胞转分化有显著抑制作用。实验拟进一步观察转化生长因子β1在白细胞介素1β诱导大鼠肾小管上皮细胞-肌成纤维细胞转分化及大黄素抑制作用中的意义。方法:实验于2006-10/2007-05在泸州医学院附属医院免疫实验室完成。⑴实验材料及分组:以培养的大鼠肾小管上皮细胞株(NRK52E)为观察对象,按如下分组分别添加不同处理因素:①对照组:仅加入体积分数为0.05小牛血清的高糖DMEM培养基。②白细胞介素1β诱导组:加含白细胞介素1β终浓度为10μg/L的高糖DMEM培养基。③SB431542阻断组:加含白细胞介素1β终浓度为10μg/L及SB431542终浓度为10μmol/L的高糖DMEM培养基。④白细胞介素1β 大黄素组:同时加分别含白细胞介素1β终浓度为10μg/L及大黄素终浓度为25mg/L的高糖DMEM培养基。⑵实验评估:培养48h后用倒置相差显微镜观察细胞形态,细胞免疫化学染色法检测肌酸激酶、α-平滑肌肌动蛋白及转化生长因子β1的表达。结果:①白细胞介素1β可诱导部分细胞由卵圆形转变为梭形,且肌酸激酶表达减弱(P<0.01),α-平滑肌肌动蛋白及转化生长因子β1表达显著增强(P<0.01)。②SB431542特异性抑制转化生长因子β1作用后,白细胞介素1β诱导的细胞形态改变受抑,同时肌酸激酶表达增强(P<0.01),α-平滑肌肌动蛋白表达减弱(P<0.01),但转化生长因子β1的表达却无明显变化。③大黄素对白细胞介素1β诱导的细胞形态改变及肌酸激酶、α-平滑肌肌动蛋白的表达有明显抑制作用,其抑制作用与SB431542的作用相比无显著差异;同时,大黄素对白细胞介素1β诱导的转化生长因子β1的表达也有明显抑制作用(P<0.01)。结论:转化生长因子β1可能介导了白细胞介素1β诱导大鼠肾小管上皮细胞-肌成纤维细胞转分化,并参与了大黄素抑制白细胞介素1β诱导大鼠肾小管上皮细胞转分化的作用。     

Markers of HIV infection in the Concorde trial. Concorde Co-ordinating Committee

The Concorde trial compared immediate (Imm) with deferred (Def) AZT monotherapy in asymptomatic HIV-positive participants. Haematological and immunological markers and weight were measured throughout, and correlated with clinical endpoints. Markers associated with disease progression (CD4 lymphocyte count and percentage, platelets, p24 antigen and beta 2 microglobulin favoured Imm: those associated with toxicity (haemoglobin, neutrophils and white cell count) favoured Def. CD8 and total lymphocyte count did not differ significantly between groups. In multivariate analysis, the combination of baseline CD4, p24 antigen and beta 2m was the best baseline predictor of disease. Including change in CD4 and beta 2m at 12 weeks, or changes over follow- up in these markers significantly improved the fit. Markers were also incorporated into the definition of 'clinical' endpoints. Hazard ratio estimates from end-points that included CD4 < 50 and CD4 < 25 were closest to those for AIDS or death alone, but added very few extra events. Use of other landmark CD4 counts (100 or greater) or relative decreases in counts (25% or more) increased the number of events, but overestimated the effect of immediate AZT. Although AZT had a beneficial effect on the surrogate markers of efficacy evaluated, these changes did not predict clinical outcome, nor could the markers be usefully incorporated into an endpoint definition.      

瘢痕疙瘩发病机制的研究动态

目的:总结瘢痕疙瘩在分子遗传学和生物化学方面的发病机制,为临床诊断和治疗提供可靠的依据。资料来源:应用计算机检索Pubmed1980-01/2006-10相关瘢痕疙瘩发病机制方面的文献,检索词“keloids”,限定文献语言种类为English。同时计算机检索中国期刊网1980-01/2006-10相关瘢痕疙瘩发病机制方面的文献,检索词“瘢痕疙瘩”,限定文献语言种类为中文。资料选择:对资料进行初审,选取包括瘢痕疙瘩发病机制的文献,开始查找全文。纳入标准:与瘢痕疙瘩和瘢痕疙瘩成纤维细胞相关的分子生物学研究。排除标准:相关的综述文献。资料提炼:共检索到681篇关于瘢痕疙瘩发病机制的文献,最终纳入33篇符合标准的文献。资料综合:瘢痕疙瘩有着过度生长、侵犯邻近组织、手术切除后极易复发、治疗效果不佳等特点,成为当今医学界面临的一个重大难题。瘢痕疙瘩发病机制迄今未明,本文从遗传机制、成纤维细胞功能、生物活性因子和胶原代谢等方面综述了近几年来对瘢痕疙瘩病因研究的最新进展,发现利用基因检测技术成为探求病因的一个重要手段和发展趋势,也为未来基因治疗提供了可靠的实验室依据。结论:越来越多的研究在瘢痕疙瘩相关致病基因位点的定位和克隆方面展开,这不但能够查找出发病原因,还可以为易感人群的早期预防提供方向,为瘢痕疙瘩的基因治疗奠定一定的基础。     

Long-term use of antecubital veins for plasma exchange. The Canadian Cooperative Multiple Sclerosis Study Group

True or sham plasma exchange was done weekly for 20 weeks in patients in two of the randomization groups in a prospective, blind clinical trial of experimental treatments for multiple sclerosis. Because patients could be randomized to receive sham plasma exchange and placebo medications, it was decided when the trial was designed that the use of fistulae, arteriovenous shunts, venous cutdowns, or other aggressive forms of venous access would not be permitted for any patient. Accordingly, patients judged to have inadequate superficial antecubital veins were ineligible for the trial. To date, only 13 (4.4%) of 294 patients considered for entry into the trial have been rejected on these grounds. In only 4 of the 93 patients undergoing exchange was it necessary to discontinue plasma exchange because of inadequate venous access. In 79.3 percent of the 1207 exchanges done in these patients, there were no problems of any kind with venous access. In 5.4 percent of these 1207 exchanges, it was necessary to terminate the procedure prematurely because of difficulties with patients' veins. Thus, the great majority of patients free of serious systemic illness (other than chronic progressive multiple sclerosis) can undergo weekly plasma exchange for up to 20 weeks using superficial antecubital veins without the need to resort to more invasive methods of venous access.