AMPK在妊娠期糖尿病发病机制中的作用

腺苷酸活化蛋白激酶是一种重要的蛋白激酶,主要作用是协调代谢和能量平衡.腺苷酸活化蛋白激酶被激活后,在增加骨骼肌对葡萄糖摄取、增强胰岛素敏感性、增加脂肪酸氧化以及调节基因转录等方面发挥重要作用.已经证实脂联素有调节糖脂代谢的作用,但其作用机制尚不十分清楚,很可能是通过腺苷酸活化蛋白激酶介导,对脂联素信号转导通路的研究将成为进一步理解脂联素作用的关键所在.而脂联素又是妊娠期糖尿病的预测因子,所以腺苷酸活化蛋白激酶逐渐成为对妊娠期糖尿病研究中的焦点.     

Expression of Mcl-1 in mantle cell lymphoma is associated with high-grade morphology,a high proliferative state,and p53 overexpression

Mantle cell lymphoma (MCL) is a distinct type of B-cell non-Hodgkin's lymphoma characterized by the t(11;14)(q13;q32) and cyclin D1 overexpression. Defects in apoptosis may contribute to pathogenesis. This study evaluated the expression of the anti-apoptotic protein Mcl-1 in two MCL cell lines and five frozen MCL tumours (four small-cell, one blastoid/large-cell) using western blot analysis. Mcl-1 expression was also assessed in 36 formalin-fixed, paraffin wax-embedded MCL tumours (24 small-cell, 12 blastoid/large-cell) by immunohistochemistry. Western blot analysis revealed the expected 37 kD protein product in both MCL cell lines and in five frozen tumours, with the blastoid case having the highest expression level. Using a cut-off of >10% immunolabelled cells for Mcl-1, it was found that 12 of 36 MCL tumours were positive. Mcl-1-positive tumours had a higher frequency of blastoid/large-cell morphology (8/12 versus 4/24, p = 0.009), p53 overexpression (3/10 versus 1/23, p = 0.04), and higher Ki67 immuno-labelling (p = 0.002). It is concluded that expression of Mcl-1 in MCL is heterogeneous. A relatively high level of Mcl-1 expression correlates with high-grade morphology, a high proliferative state, and p53 overexpression.     

Primary follicular large cell lymphoma of the testis in a child

Primary follicular lymphoma of the testis in childhood is extremely rare. To our knowledge, only 5 cases have been reported to date. We report a case in a 6-year-old boy who presented with painless right scrotal enlargement. Right radical orchiectomy revealed a follicular large cell lymphoma with diffuse areas confined to the testis and epididymis, clinical stage IE. Immunohistochemical stains demonstrated that the neoplastic cells were of B-cell lineage, positive for CD10, CD20, CD79a, and BCL-6. Staining for CD21 accentuated networks of dendritic reticulum cells within the nodules. The cells were negative for BCL-2, p53, and T-cell antigens. There was no evidence of the t(14;18) detected by polymerase chain reaction. The data suggest that follicular lymphoma of the testis in children has a different pathogenesis than follicular lymphoma in adults.     

藏汉民族线粒体基因组全序列的比较研究

目的 以藏汉民族线粒体基因组全序列为基础,进行Haplogroup构建和系统发生分析,在全序列水平上比较核苷酸的变异,阐释可能的变异机制和蕴含的生物学意义.方法 采用Applied Biosystems 3730DNA自动测序仪分别对40名藏族和50名汉族的标本进行线粒体DNA序列测定,应用phredPhrap 16.0软件进行全序列拼接,并以rCRS(revised Cambridge Reference Sequence)为标准与测定序列进行比对分析;根据MTTO-MAP的标准,通过Network方法进行Haplogroup构建和系统发生的分析,并结合其它方法对产生的数据进行深入解读.结果 数据分析结果显示:在系统发生上,藏汉民族90个线粒体DNA序列归类到13个Haplogroups,除M9以外,其它各Haplogroup出现频率之间比较差异无统计学意义;通过两个民族的线粒体DNA全序列比对,发现21个分布频率有统计学意义的变异位点,其中的5个为新变异位点;另外,对D-Loop区的5个突变位点进行了单倍型构建,90个标本可分为2种Supertype,发现在藏汉民族之间Supertypel和Supertype 2的分布频率均有统计学意义.结论 藏汉民族在种族起源和系统发生上具有较近的母系遗传关系;在全序列有统计学意义的位点究竟是适应性或者中性选择,抑或是一种病理性突变尚需深入的探讨.     

In vitro and in vivo interaction between murine fibrosarcoma cells and natural killer cells

Murine fibrosarcoma cells were examined for sensitivity to killing by natural killer (NK) and natural cytotoxic lymphocytes from mouse spleens. These tumor cell lines were sensitive to killing by effector cells which were nonadherent to plastic or nylon wool, Thy-1 negative, asialo-GM1 negative, and present in the spleens of beige mice, nude mice, and A/J mice, as well as in the spleens of normal syngeneic and allogeneic control mice. This indicates that the cytotoxic effects were due to natural cytotoxic lymphocytes rather than to NK lymphocytes, T-cells, or macrophages. Although the fibrosarcoma cells were not killed in vitro by endogenous NK cells, these tumor cells were able to "cold target" compete for Yac-1 (an NK-sensitive target) killing and to bind to asialo-GM1-positive, nonadherent spleen lymphocytes in a target cell binding assay. This suggests that the fibrosarcoma cells were recognized by NK cells. In addition, these cell lines were killed in a 4-h NK cytotoxicity assay by polyinosinic-polycytidylic acid-activated effector lymphocytes. The interaction between NK cells and the murine fibrosarcoma cells may have in vivo significance. When syngeneic mice were treated with anti-asialo-GM1 serum to eliminate NK activity and then given i.v. injections of the fibrosarcoma cells, many more lung tumors developed than in control animals. The structural basis for the recognition of the murine fibrosarcoma cells by the NK effector cells is not known. However, laminin may be involved. When the fibrosarcoma cells, which have receptors for the laminin molecule, were preincubated with laminin, they were reduced in their ability to compete for the killing of Yac-1 cells by the NK effectors and had reduced capacity to bind to NK cells in a target cell binding assay.     

Evaluation of Job Strain of Family Physicians in COVID-19 Pandemic Period- An Example from Turkey

Journal of Community Health - The purpose of this study was to evaluate family physicians’ job strain during the Covid-19 pandemic and determine the effective factors. The study was carried...     

松质骨中两种纵波的传播特性分析

基于松质骨的层状模型，利用Schoenberg理论分析了松质骨中两种纵波(快纵波和慢纵波)的传播特性；并在理论和实验上详细分析了骨小梁方向与传播方向间的夹角对松质骨中快纵波和慢纵波传播特性的影响。分析结果表明，当超声波平行于骨小梁入射时，松质骨中两种纵波都传播，入射角度在60度附近时，松质骨中两种纵波的相速度曲线有一个转折点，入射角度在60度以上，角度越大时，骨髓和骨小梁耦合得越紧，因此阻止了慢纵波的传播，而只有快纵波传播。