胎牛血清外泌体对成骨细胞增殖的作用

背景:研究表明外泌体具有促进骨再生的能力,但从胎牛血清中提取的外泌体是否可以促进骨形成仍存在争议。目的:观察胎牛血清外泌体对成骨细胞增殖能力的影响,从而为临床治疗骨破坏提供新思路。方法:通过超速离心法从胎牛血清中提取外泌体,采用透射电子显微镜和Western blot法验证外泌体是否提取成功;然后用10 mg/L胎牛血清外泌体干预成骨前体细胞MC3T3-E1,通过CCK-8实验检测外泌体对成骨细胞增殖能力的影响,Western blot检测外泌体对成骨细胞骨形态发生蛋白2和骨桥蛋白表达的影响。以不含外泌体的胎牛血清培养的MC3T3-E1细胞为对照组。结果与结论:①胎牛血清外泌体具有典型的脂质双层膜结构,大小在30-150 nm之间,外泌体表面标记因子CD81表达呈阳性,而微囊表面标记物CD40表达呈阴性;②外泌体组的增殖能力明显高于对照组,差异有显著性意义(P<0.05);外泌体组成骨标志性因子骨形态发生蛋白2和骨桥蛋白的表达水平明显高于对照组,差异有显著性意义(P<0.05);③结果表明,胎牛血清外泌体对成骨细胞的增殖起促进作用,可为临床治疗骨破坏提供新思路。     

阻塞性睡眠呼吸暂停低通气综合征的MRI研究

目的：探讨磁共振成像（MRI）对确定阻塞性睡眠呼吸暂停低通气综合征（OSAHS）病人阻塞部位的作用。方法：通过对35例OSAHS男性患者行多导睡眠仪、MRI及纤维喉镜检查配合Muller’s运动检查（FEMM）、同时对30例男性健康人的上呼吸道进行MRI检查，将两者检查结果进行比较，判定OSAHS患者上呼吸道狭窄的部位及狭窄程度，客观评价MRI对检查OSAHS患者的应用价值。结果：OSAHS患者的上呼吸道截面积明显小于健康人，轻度OSAHS患者多存在腭咽平面狭窄；中重度组OSAHA患者大部分所有平面都存在狭窄，但中度组以腭咽狭窄较明显，而重度组所有平面均存在较明显的狭窄，这种狭窄主要是由于口咽部周围软组织增生及软腭过长、肥厚及舌根宽大、肥厚所致。结论：MRI检查可判定OSAHS患者上呼吸道狭窄的部位及狭窄程度，有助于治疗方案的选择，对预估手术疗效具有重要的意义。     

BAFF supports human B cell differentiation in the lymphoid follicles through distinct receptors

B cell-activating factor of the tumor necrosis factor family (BAFF/BLys) plays a critical role in B cell survival and immune responses through its three receptors: BAFF receptor (BAFF-R/BR3), transmembrane activator and calcium modulator and cyclophilin ligand interactor (TACI) and B cell maturation antigen (BCMA). Using specific antibodies, we have investigated the expression of BAFF-R on human tonsillar B cells and their functional roles in naive and germinal center (GC) B cell differentiation. Our studies show that BAFF-R is the dominant receptor on naive B cells. However, three receptors are differentially modulated during in vitro GC-B cell differentiation. BAFF-R expression increased initially and then decreased with a corresponding induction of TACI and BCMA expression during differentiation to plasma cells (PCs). Consistently, blocking of BAFF-R alone with specific mAb inhibited GC-B cell proliferation and PC generation in the early period of their differentiation, whereas depletion of BAFF with TACI-Ig exhibited consistent inhibition throughout the differentiation. Finally, histological and molecular analyses of human tonsil tissue revealed that follicular dendritic cells produce BAFF. In conclusion, BAFF in the GC plays an important role through more than one receptor, and the three known receptors are differentially modulated as GC-B cells differentiate to PCs.     

妊娠高血压患者血浆中降钙素基因相关肽的测定及其临床意义

本文测定了３０例正常育龄妇女，２８例正常妊娠以及３６例妊娠征患者血浆中降钙素基因相关肽的水平，结果发现，轻度妊高生与正常妊娠相比，血浆中ＣＧＲＰＫ是有下降但不显著（Ｐ〉０．０５）。中重度妊高征与正常妊娠相比，差异有非常显著性，因此推测，妊娠状态下血浆中降钙素基因相关肽的减少可能是妊娠高血压症产生的重要原因之一。     

Comparison of Real-Time, Quantitative PCR with Molecular Beacons to Nested PCR and Culture Methods for Detection of Mycobacterium avium subsp. paratuberculosis in Bovine Fecal Samples

An automated PCR with fluorescent probes (molecular beacons) detected Mycobacterium avium subsp. paratuberculosis in bovine feces. When the PCR was compared with culture in testing 41 fecal samples, kappa scores of 0.94 to 0.96, a sensitivity of 93 to 96%, and a specificity of 92% were obtained. Results were quantitated by using a standard curve derived from a plasmid containing IS900. A minimum quantity of 1.7 x 10(-4) pg of DNA, correlating to 1 to 8 CFU, was detected.     

Association between attention deficit hyperactivity disorder and the DXS7 locus

Attention deficit hyperactivity disorder (ADHD) is a prevalent disorder in children. The etiology of this disease is not clear. Genetics studies have suggested the involvement of the dopamine DRD-4 receptor gene and dopamine transporter gene (DAT1). Clinical studies have shown that monoamine oxidase-B (MAO-B) inhibitors are effective in the treatment of ADHD. These findings suggest that monoamine oxidase (MAO) genes might be involved in the origin of ADHD. In the present work, the DXS7 locus of chromosome X, which is closely linked to MAO genes, was selected as a marker to study the possible association between ADHD and MAO genes in the Chinese population. Haplotype-based haplotype relative risk (HHRR) and the transmission disequilibrium test (TDT) methods were employed to analyze the association and the linkage disequilibrium, respectively. Significant association (X(2) = 15.86; 1 df; P < 0.001) and linkage (X(2) = 14.88; 1 df; P < 0.001) were detected between the 157-bp allele of the DXS7 locus and the DSM-III-R-diagnosed ADHD (N = 72) in trios composed of father, mother, and affected offspring. The data suggested that ADHD was associated and in linkage with DXS7 locus.     

Chemokine receptor expression on human eosinophils from peripheral blood and bronchoalveolar lavage fluid after segmental antigen challenge

BACKGROUND: The recruitment of circulating eosinophils to the lung is a characteristic feature of allergic airway inflammation. Chemokine receptors likely play a role in this complex process. However, reports of chemokine receptor expression on human eosinophils are conflicting. OBJECTIVE: The aim of this study was to determine whether the chemokine receptor profile of human eosinophils change when these cells are recruited to the airway after an antigen challenge and development of an allergic inflammatory response. METHODS: Blood and bronchoalveolar lavage (BAL) cells were obtained from 13 allergic subjects 48 hours after segmental bronchoprovocation with antigen. The CC chemokine receptor (CCR) 1 to 7, 9, and CXC chemokine receptor (CXCR) 1 to 4 were determined by flow cytometric analysis of whole blood and unseparated BAL cells. RESULTS: Compared with their circulating counterparts, airway eosinophils had decreased CCR3 and increased CCR4, CCR9, and CXCR3 expression on their cell surface. Furthermore, expression of CCR3, CCR4, and CXCR3 was significantly correlated with the percentage of eosinophils in BAL fluid at 48 hours. Eosinophils also expressed CXCR4, but this receptor did not change after antigen-induced recruitment to the airway. In contrast, the expression of CCR1, CCR2, CCR5, CCR6, CCR7, CXCR1, and CXCR2 remained undetectable on either blood or BAL eosinophils. CONCLUSIONS: Our data suggest that recruitment of eosinophils to the airway is associated with a modulation of their chemokine receptor profiles. These changes in chemokine receptors could be involved in determining eosinophil function and antigen-induced airway inflammation.     

用Flash动态演示PN结的形成过程

本文通过用Flash 5．0制作《医学电子学》中PN结的形成过程的介绍，在熟悉Flash 5．0制作方法的同时．完成相应的多媒体教学。     

鸡胚心脏外形变化及心外膜的发生

本研究用扫描电镜、透射电镜和光镜,观察了早期鸡胚心脏发生的外形变化及心外膜的发生。1.心脏发生经历2个阶段,首先是心脏的成襻过程,心管表面的一定部位出现沟,沟相应部位内面出现嵴。心襻的完成,标志着心脏各部原基的确立。第2个阶段是心脏各部原基的进一步分化,包括心腔内部的分隔及心脏各部位置的变化。心房与心锥的移位,可能是受左右心室移位的影响。2.心外膜片并非由心肌外层原位分化,而是由静脉窦处的间充质细胞增殖,并迁移覆盖在心肌层表面形成。