老年大鼠下丘脑视上核和弓状核的超微结构变化

观察老年大鼠下丘脑视上核腹侧大细胞神经元和弓状核神经元的超微结构,结果显示:老年大鼠视上核腹侧血管加压素(VP)神经元的胞体较成年鼠大,胞质结构比较致密,内含许多核糖体颗粒,粗面内质网分散成小泡状,神经分泌颗粒增多,溶酶体、线粒体、高尔基氏复合体数量都较多.而弓状核内的暗细胞和亮细胞的核糖体减少,高尔基氏复合体和线粒体都变化,还有少数神经元固缩,细胞质内胞器明显减少,呈现变性现象.结果提示:老年期下丘脑视上核VP神经元机能增强;而弓状核内两种细胞都显示机能减弱的征象.老年时下丘脑各核团神经元的这种不协调性变化,可能是动物衰老的一种重要表现.     

Comparative study of the prognostic value of nuclear grade and silver-binding nucleolar organizer region in renal cell carcinomas.

Silver-binding nucleolar organizer region (AgNOR) and nuclear grade were histologically assessed in 112 renal cell carcinomas. Nuclear grade was better capable of stratification than AgNOR in terms of survival prediction. It also had prognostic significance when total metastatic rates were evaluated. Although higher mean AgNOR numbers were constantly associated with higher nuclear grades, two arbitrary classifications of AgNOR (less than 1.5, 1.5-3.5, greater than 3.5; less than 2, 2-3, greater than 3) failed to resolve the survival difference.     

Predictive validity of a national examination for medical graduates in the People's Republic of China

National examinations for medical graduates were introduced on an experimental basis in the People's Republic of China in 1982. To estimate the predictive validity of the National Medical Examination (NME), an investigation of the postgraduate competence of a sample of the participating examinees was conducted in 1984. The sample consisted of 1,717 of the 4,995 graduates from 13 medical colleges who had taken the initial NME. Their scores on the NME and the ratings given them by directors of postgraduate programs in nine aspects of clinical competence were compared by frequency distribution and product-moment correlation coefficients. Scores on the NME were consistent with measures of postgraduate clinical competence and, as a whole, correlated significantly with the ratings of clinical competence, supporting the use of the score on the NME as a predictor of postgraduate clinical competence. However, the extent of the relationship between the NME score and postgraduate clinical competence varied according to the specialty program of postgraduate medical training.     

Regulation of thrombin-induced mast cell degranulation by zinc and manganese

This study was undertaken to determine whether zinc, manganese and copper could regulate the thrombin-induced secretion of the granule-associated mediator, beta-hexosaminidase, from mast cells derived from mouse bone marrow. Exposure of thrombin to copper (2-100 microM) does not affect the enzyme-induced release of beta-hexosaminidase from the mast cells. Zinc at 50 microM reduced the degranulation of calcium ionophore A23187 activated cells by 75% and that of immunological challenge or thrombin by 30% each. Exposure of the thrombin to incremental concentrations of manganese (2-100 microM) prevents its degranulation activity in a dose-related fashion. 75% inhibition of the enzyme activity was achieved at 100 microM manganese. However, exposure of IgE sensitized or unsensitized cells to incremental concentrations of manganese (2-400 microM) prior to antigen or calcium ionophore A23187 stimulation, does not significantly affect the exocytosis of beta-hexosaminidase. The binding of purified human FITC-thrombin to E-mast cells was analyzed by fluorescence flow cytometry. All cells bound specifically the labelled thrombin. Pretreatment of the FITC-thrombin with 100 micron zinc or manganese had no effect on the binding of the labelled thrombin to the cells. It was assumed that manganese modulates either directly the thrombin activity or the substrate for the enzyme on the cell surface.     

双色间期荧光原位杂交定量监测治疗中CML患者的肿瘤细胞负荷

目的　研究双色间期荧光原位杂交 (I-FISH)技术监测CML治疗过程中肿瘤细胞负荷的灵敏度及特异性。方法　应用I-FISH、常规细胞遗传学 (CCG)G显带技术和筑巢式逆转录聚合酶链式反应 (RT -PCR)技术对 2 0例治疗中CML患者骨髓中的肿瘤负荷进行检测。结果　对照组骨髓细胞假阳性率为 0 6 %～2 0 % ,分界值为 2 4 5 % ;2 0例患者经IFN -α治疗或骨髓移植后 9/18例(5 0 % )CCG检测到Ph( )细胞 ,阳性细胞率 16 7%～ 10 0 % ;结合正常分界值 ,16 /2 0例 (80 % )经I-FISH检测到BCR -ABL( )肿瘤细胞 ,阳性细胞率 2 8%～ 99 6 %。 16例患者行RT -PCR检查 ,13/16例 (81 3% )融合基因转录本阳性。结论　I -FISH技术可高度灵敏、特异地监测CML患者治疗过程中肿瘤细胞负荷的变化 ,与CCG及RT -PCR相比 ,检测所得结论更加科学、合理和具有说服力。     

Bryostatin 1-induced modulation of nucleoside transporters and 2-chlorodeoxyadenosine influx in WSU-CLL cells

WSU-CLL cells, a fludarabine resistant B-cell chronic lymphocytic leukemia cell line, has been shown to exhibit enhanced sensitivity to 2-chlorodeoxyadenosine (2-CdA) following 48-72 h exposure to bryostatin 1. For 2-CdA to manifest its chemotherapeutic activity, it must first enter the cell through one of several specific nucleoside transporter systems. We present data to show that bryostatin 1-induced enhanced influx of 2-CdA is in part the result of bryostatin 1-induced modulation of nucleoside transporters in WSU-CLL cells. The bi-directional equilibrative NBMPR sensitive transporters in WSU-CLL cells were significantly down-regulated 90 min post-exposure to 1-200 nM bryostatin 1. This down-regulation was evident up to 144 h. In contrast, WSU-CLL cells exhibited a transient increase in Na+-dependent concentrative 2-CdA influx from 48 to 96 h after bryostatin 1 exposure which was evident for a longer duration than that accounted for by the increase in deocycytidine kinase activity. These data may, in part, explain the enhanced efficacy of 2-CdA seen in WSU-CLL cells following 48-72 h exposure to bryostatin 1. It may raise questions as to the importance of the bi-directional transporters in determining the resistance or sensitivity of CLL cells to 2-CdA or other nucleoside analogues.     

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.     

人Nanog基因的克隆及其在COS-7L细胞中的表达

目的 :克隆人Nanog基因 ,构建其真核表达载体 ,并观察其在哺乳动物细胞COS 7L中的表达。方法 :利用HE2 93细胞的人基因组DNA为模板 ,以LA PCR技术 ,扩增Nango的基因 ,定向克隆到带Flag标签的pCMV载体中 ,测序后 ,挑选序列正确的真核表达质粒pFlag Nanog转染COS 7L细胞。用抗Flag标签的抗体 ,进行Westernblot和间接免疫荧光染色法检测Nango蛋白的表达。结果 :从人基因组DNA中克隆到序列正确的Nanog全长编码序列。所构建的Nanog质粒在COS 7L细胞中获得高效表达。结论 :人Nanog基因的克隆、真核表达载体的构建及在COS 7L中的表达均获得成功 ,为进一步研究其功能 ,尤其是探讨其在神经干细胞中的作用奠定了基础。     

优化的贴片型测量探头及其生物医学应用研究

采用时域有限差分（FDTD）法结合遗传算法（GA）优化设计了适用于浅表生物组织高频测量的宽带同轴贴片探头，并用该探头测量了人体背部1～7GHz频带内的反射特性。优化设计出的圆形同轴贴片探头具有轴对称特点，辐射近场在生物组织中透人深、反射系数的频率响应特性好。所获得的人体背部反射特性的测量结果将为背部浅表组织电特性的重建提供有利的依据。