21-三体嵌合型母亲二次妊娠21-三体患儿

目的报告1例嵌合型母亲连续2次孕育单纯型21-三体患儿。方法对21-三体患儿、21-三体胎儿和其父母的血标本、父亲精子进行了DNA多态性检测,选择2个SRTR多态性位点,即D21S1412和D21S11,进行荧光定量PCR检测以确定额外21号染色体的起源。对父亲和母亲的外周血染色体和母亲皮肤染色体也进行了分析。结果对2个患儿与双亲的STR结果进行比较,显示2个患儿的额外21号染色体都来自母亲。双亲的STR检测中仅发现有2个微卫星标志物,外周血淋巴细胞染色体也均为正常。但母亲皮肤成纤维细胞检测到21-三体的细胞存在,占4%。结论母亲是21三体细胞/正常细胞的嵌合体,推测母亲生殖细胞中存在21三体细胞与正常细胞的嵌合,这可能是导致连续2次孕育21-三体患儿的原因。     

Springer Link及其收录的医学期刊分析

目的：向图书馆员和用户介绍Springer Link，对其收录的医学期刊进行深入分析，使该数据库得到更好的利用。方法利用《外国报刊目录》和美国《医学索引》(IM)的《引用期刊一览表》等对Springer Link收录的英文医学期刊从权威性、出版地分布、学科分布和收藏年限等方面进行考查。结果86％的期刊被IM引用，欧洲——尤其是德国的期刊较多，医学各学科都有相应的期刊被收录，但数量分布不均，有所偏重，72．7％的期刊可以保证至少近5年或自创刊以来的文献。结论Springer Link所提供的全文医学期刊服务质量较上乘，并有自己的特色。     

人胚胎大脑海马发育过程中凋亡神经元超微结构观察

本文借助电子显微镜技术对 4月胎龄组及 6月胎龄组水囊引产胎儿海马中段部位的凋亡神经元超微结构进行观察、拍照 ,并对结果进行了分析讨论。结果显示 :两组对象中均可见凋亡神经元 ,所见的凋亡神经元的超微结构变化基本相同 ,即细胞核内有明显的染色质边集和凝结成块的现象 ,并可见核膜皱缩和扭曲。另外 ,6月组凋亡细胞的结构变化较 4月组更为明显。在 6月组细胞质内和核内均有小体出现 ,其他细胞器无显著变化。从而更进一步说明在胚胎海马发育中存在着神经元不同性质的死亡现象 -即正常死亡和凋亡。而且提出 6月组显现出更为明显的凋亡神经元形态变化     

医学综合评价性问题的定性分析与定量灰关联分析研究

采用定性分析与定量灰关联分析相结合的方法处理医学综合评价性的问题和诊断性的问题。定义了诊断值，诊断灰度和信息覆盖率等医学新概念，实例应用说明，这种分析研究和于临床诊断时，诊断符合率高，误诊率低，而且克服了一般医学诊断模式只能定性分析，不能作定量分析的缺点。     

Rapid identification and susceptibility testing using the VITEK(R) 2 system using culture fluids from positive BacT/ALERT(R) blood cultures

BACKGROUND AND PURPOSE: In order to reduce the turnaround time for laboratory diagnosis of bacteremia, the efficacy of identification and antimicrobial susceptibility testing using samples taken directly from positive BacT/ALERT(R) standard aerobic and standard anaerobic blood culture bottles was evaluated. METHODS: 160 positive blood culture bottles were examined and incubated at 35 degrees C in 5% carbon dioxide for 4-24 h, and an aliquot of the culture fluid was Gram stained. Samples containing Gram-negative bacilli were inoculated on VITEK(R) 2 ID-GNB (identification-Gram-negative bacilli) and AST (antimicrobial susceptibility testing)-GN04 cards, and those containing Gram-positive cocci were inoculated on ID-GPC (identification-Gram-positive cocci) and AST-P526 cards. The same samples were also examined by the standard method, involving subculture from positive BacT/ALERT standard blood culture bottles. RESULTS: Eighty seven of 97 Gram-negative bacilli (89.7%) and 21 of 63 Gram-positive cocci (33.3%) were correctly identified to the species level. For antimicrobial susceptibility testing, the direct method had an overall error rate of 5.4% for Gram-negative bacilli, with 0.9% very major, 0.9% major, and 3.6% minor discrepancies compared to the standard method. The overall error rate in antimicrobial susceptibility testing for the 13 Staphylococcus spp. was 10.3%, with 6.0% very major, 2.6% major, and 1.7% minor discrepancies. CONCLUSION: These data suggest that VITEK 2 cards inoculated with samples taken directly from positive Bact/ALERT blood culture bottles would provide acceptable identification and antimicrobial susceptibility testing results for Gram-negative bacilli, but not for Gram-positive cocci. Compared to the standard method, the direct method would reduce turnaround time by at least 24 h.     

双重实时荧光定量PCR法鉴定克柔念珠菌和光滑念珠菌

目的 建立一种快速、灵敏、特异的鉴定克柔念珠菌和光滑念珠菌的双重实时荧光定量PCR方法.方法 以核糖体基因内转录间隔区Ⅱ(ITSⅡ)为靶目标,设计并合成分别针对克柔念珠菌、光滑念珠菌的种特异引物和探针.建立双重实时荧光定量PCR反应体系,并用该体系对呼吸道相关致病菌进行检测.鉴定结果与临床常规鉴定方法对照,评价其敏感度、特异度及重复性.结果 通过对100例样品的检测,结果显示该双重实时荧光定量PCR法检测标本的鉴定结果与常规鉴定方法的结果对照,特异度为100%,敏感度为100%;最小能检测到10个拷贝数的重组质粒;批内重复实验和批间重复实验结果均与常规鉴定方法结果相符.结论 双重荧光定量PCR法鉴定克柔念珠菌和光滑念珠菌,特异度和敏感度高,重复性好,且快速、简便,该方法将有助于念珠菌病的早期诊断和针对性治疗.     

Proximal tubular epithelial cell integrins respond to high glucose by altered cell-matrix interactions and differentially regulate matrixin expression

Thickening of the tubular basement membrane (TBM) occurs in diabetic nephropathy, but the effects of high glucose on the functional aspects of proximal tubular epithelial cells are not clearly understood. In the present study, we examined the effects of elevated glucose concentrations on (a) integrin expression by human proximal tubular epithelial cells (HK-2) and integrin-mediated interactions with type IV collagen (colIV) and laminin, major components of TBM; (b) the expression of matrixins/matrix metalloproteinases (MMPs), which is regulated by integrins; and (c) the expression of tissue inhibitors of metalloproteinases (TIMPs). HK-2 cells cultured in 25 mM glucose underwent a reduction of the expression of alpha3, beta1, alpha(v)beta3, and alpha5 integrin subunits, with a concomitant increase of the alpha2 subunit, compared with cells grown in 5 mM glucose. Adhesion experiments demonstrated that high glucose led to increased cell adhesion on either colIV or laminin. Experiments of competition of adhesion using anti-integrin antibodies indicated that HK-2 cells in 5 mM glucose used mainly alpha(v)beta3 and alpha5beta1 integrins to adhere to colIV, whereas in 25 mM glucose they additionally used alpha2beta1. In the case of laminin, a beta1-mediated adhesion was observed when HK-2 cells were in 5 mM glucose, whereas in 25 mM glucose, alpha2beta1 and alpha(v)beta3 were also involved. Elevated glucose concentrations resulted in decreased expression of MMP-9 and MMP-2, whereas an increase in TIMP-1 and a decrease in TIMP-2 expression were observed. We also examined which integrins mediated the expression and secretion of matrixins MMP-2 and MMP-9. Ligation of alpha3beta1 with mAbs resulted in induction of MMP-2 expression and secretion, whereas antibody ligation of alpha(v)beta3 led to down-regulation of MMP-9. The above data implicate integrins of proximal tubular epithelial cells in the regulation of MMPs and in the development of TBM thickening in diabetic nephropathy.     

Comparison of immunohistochemical markers in the differential diagnosis of adrenocortical tumors: immunohistochemical analysis of adrenocortical tumors.

Most adrenocortical tumors (ACTs) can be diagnosed directly by a combination of morphologic features and clinical findings. However, sometimes it may be difficult to distinguish ACTs from other neoplasms such as pheochromocytomas and some metastatic tumors, particularly for small biopsy specimens because they may be morphologically similar. Expression of calretinin has recently been suggested as a valuable immunomarker for the differential diagnosis between ACTs and other tumors; however, its diagnostic value is still under debate. To determine the diagnostic value of calretinin in Chinese patients with adrenocortical and non-ACTs, we employed both polyclonal and monoclonal anticalretinin to characterize the expression of calretinin in adrenal tissues and compared its expression with that of inhibin alpha, Melan-A, cytokeratin, or CD99 by immunohistochemistry in tissue microarrays and standard tissue sections of 414 specimens. Our results revealed that calretinin was expressed by adrenocortical cells, but not by the other cells tested and the percentage of calretinin-positive ACTs reached 99% when stained with polyclonal antibodies, which was higher than that with monoclonal anticalretinin (91.3%), anti-Melan-A (90.3%), antiinhibin alpha (81.6%). In addition, our results also revealed that ACTs were stained by cytokeratin (AE1/AE3) with variable degrees (58.7%). Furthermore, unlike anti-Melan-A that stained all metastatic malignant melanoma, anticalretinin did not recognize other tested tumors. Therefore, immunohistologic staining with polyclonal anticalretinin is more sensitive than other antibodies tested for the diagnosis of ACTs. However, monoclonal anticalretinin appeared to be more specific. Importantly, our data suggested that the fried-egg-like staining pattern, but not the mere cytoplasmic staining, was characteristic of anticalretinin staining in adrenocortical tissues. Notably, a few anticalretinin negative-ACTs were stained by other immunomarkers that we tested. Thus, the combinational characterization of calretinin (either by polyclonal or monoclonal antibody), inhibin alpha, and Melan-A expression is of great significance in the differential diagnosis of ACTs.     

儿童呼吸道腺病毒基因分型方法的建立及其应用

目的 利用PCR技术,建立引起儿童呼吸道感染的腺病毒的基因分型方法,便于推广和应用.方法 分析GenBank中不同型别腺病毒的六邻体基因序列特点,设计不同型腺病毒的特异性引物,以PCR方法进行基因分型,建立基因分型方法,并利用此方法对广州市2004年7月某幼儿园流行的腺病毒感染进行了基因分型.结果 建立了呼吸道腺病毒的基因分型方法.广州市2004年7月某幼儿园流行的腺病毒为3型腺病毒.结论 PCR方法可进行腺病毒的基因分型,且简便、结果可靠,便于推广应用.     

负压封闭吸引对糖尿病溃疡愈合的促进作用

目的 在"创而床准备(WBP)"理论指导下,观察负压封闭吸引局部处理糖尿病溃疡的疗效.方法 收集2000年1月至2005年1月间收治的27例糖尿病溃疡患者作对照组,2005年1月至2007年6月的8例糖尿病溃疡患者为试验组.两组患者均经常规系统的治疗,试验组在创面的黑、黄期采用清创后负压吸引治疗.观察两组创而各分期间的演进情况.比较两组手术Ⅰ期修复率、入院首次及实施负压治疗后1、2、3周创面细菌学检查结果 .观察各期创面组织标本的HE染色和黄、红两期Ⅰ、Ⅲ型胶原纤维苦味酸-天狼猩红染色结果 及对其含量进行图像分析.结果 试验组患者创面各分期的演进速度、于术Ⅰ期修复率均优于以照组(100%比46%,P<0.05).治疗2周后试验组创面末检出致病菌,对照组检出率为66.7%(P<0.05).HE染色显示试验组各期间的演进类似于急性创面愈合过程,且试验组黄期Ⅰ、m型胶原总含量为12.28%,对照组为24.77%(P<0.01).结论 基于WBP方案的负压吸引治疗能促进糖尿病溃疡的创面愈合过程.