An intracellular antigen that reacts with MO2, a monoclonal antibody to CD14, is expressed by human lymphocytes

CD14, a lipopolysaccharide (LPS) receptor, is present on the surface membrane of phagocytic leukocytes; it is also present in a soluble form in serum. Recently published results confer to this molecule novel functions that are linked to T-cell activation and to apoptosis. We report here that we have defined and characterized a novel lymphocyte population in human peripheral blood, a population that expresses an intracellular antigen detectable with MO2, a monoclonal antibody directed against the human CD14 molecule. This population is composed primarily of CD8-positive T-cells. We found surprisingly that this novel MO2-positive population of lymphocytes was greatly enhanced in asymptomatic, untreated HIV-positive individuals.     

Smad7过度表达抑制3T3细胞增殖和TGF-β1基因表达

研究Smad7过度表达对TGF β1基因表达的调控和对 3T3细胞增殖的影响。实验将Smad7质粒 ,通过脂质体介导转染NIH3T3细胞 ,应用RT PCR方法鉴定转染结果和检测TGF β1mRNA的表达 ,以及用免疫细胞化学检测TGF β1蛋白的表达情况 ,并观察基因转染对细胞增殖的影响。结果显示转染Smad7后 ,NIH3T3细胞中TGF β1mRNA的表达显著减少 (P <0 0 5 ) ,TGF β1蛋白的表达下降 ,细胞增殖明显减缓 (P <0 0 5 )。提示Smad7过度表达能够抑制 3T3细胞的增殖和TGF β1基因的表达 ,可以通过阻断TGF β细胞内信号传导来调控TGF β1的生物学行为。     

Characterization of HLA DR3/DQ2 transgenic mice: a potential humanized animal model for autoimmune disease studies

Linkage studies indicate close associations of certain HLA alleles with autoimmune diseases. To better understand how specific HLA alleles are related to disease pathogenesis, we have generated an HLA DR3/DQ2 transgenic mouse utilizing a 550-kb yeast artificial chromosome (YAC) construct containing the complete DRalpha, DRbeta1, DRbeta3, DQalpha, and DQbeta regions. The transgenic mouse (4D1/C2D) in an I-Abeta(o) background appears healthy with no signs of autoimmune diseases. Lymphoid tissues as well as CD4(+) T cells develop normally. Characterization of the transgene expression demonstrates that approximately 90% of B cells express high levels of DR3 and 50-70% of B cells express DQ2. CD11c(+) dendritic cells express high levels of DR and DQ. Approximately 12-18% of resting T cells are positive for DR expression, and further up-regulation to 40-50% expression is seen upon activation with anti-CD3/anti-CD28 mAb. These results suggest that the transgenic construct confers a high fidelity to the normal human temporal and spatial expression profile. Analysis of T cell receptor repertoire in transgenic mice confirms that DR3/DQ2 are able to mediate thymic selection. Furthermore, transgenic mice respond to a DR3-restricted antigen, demonstrating antigen processing and presentation by antigen-presenting cells (APC). Purified T cells from ovalbumin (OVA)-immunized 4D1 mice respond to human APC co-cultured with OVA, suggesting appropriate antigen/DR3 or DQ2 recognition by murine T cells. Immunoglobulin isotype switching is also observed, indicating functional T-B cognate interactions. Thus, the DR3/DQ2 transgenic mouse has normal lymphoid development and functionality that are mediated by HLA transgenes and can be used to investigate HLA-associated immunological questions.     

鼠巨细胞病毒抑制神经干细胞分化及分化基因表达的体外研究

目的 研究鼠巨细胞病毒(MCMV)感染对体外培养神经干细胞(NSCs)分化及分化基因表达的影响,探讨CMV先天感染致神经损伤的机制.方法 体外分离培养和鉴定BALB/c胎鼠NSCs并检测其分化潜能,用感染复数(MOI)为5、1和0.1的MCMV Smith毒株感染NSCs并进行分化培养,倒置显微镜下观察细胞形态学改变,流式细胞术检测分化细胞比率,免疫荧光法观察NSCs及其分化细胞标记物Nestin、胶质纤维酸性蛋白(GFAP)和神经元特异性烯醇化酶(NSE)表达的变化,采用MCMV早期抗原(EA)示踪感染过程(MOI=1),real-time RT-PCR检测分化早期NSCs Wnt信号途径关键分化基因Wnt-3和Wnt-Ta mRNA水平的动态变化.结果 体外培养的NSCs呈球样生长,神经干细胞特异性标记Nestin表达阳性,并可进一步诱导分化为NF-200阳性的神经元和GFAP阳性的星形胶质细胞;分化培养后,感染组NSCs不能贴壁分化生长并逐渐出现肿胀,细胞Nestin表达下调缓慢并显著高于正常对照组,而GFAP和NSE表达显著低于正常对照组(P<0.05),可检测到MCMV EA的阳性表达;分化培养3-9 d,感染组Nestin阳性细胞比率显著高于正常对照组,GFAP和NSE阳性细胞比率显著低于正常对照组(P<0.05);感染组Wnt-3 mRNA水平在分化培养后第1～2天显著低于正常对照组(P<0.05),感染组Wnto-7a mRNA水平在第0.5～2天明显低于正常对照组(P<0.05);感染组和正常对照组的差异随病毒MOI的增加而更加明显.结论 MCMV感染可明显抑制NSCs向神经元和星形胶质细胞方向分化,导致分化细胞比率减少;下调或干扰NSCs wnt信号途径分化基因wnt-3和Wnt-7a的表达;抑制NSCs分化及其分化基因表达的效应与MOI大小存在一定量效依赖关系;MCMV可能通过抑制NSCs分化基因的表达来抑制其分化,这可能是CMV先天感染致脑发育异常的重要机制之一.     

Oxidative capacity interacts with oxygen delivery to determine maximal O2 uptake in rat skeletal muscles in situ

When intracellular recordings were made from the antral region of murine stomach, cells with three different patterns of electrical activity were detected. One group of cells generated follower potentials, the second group generated pacemaker potentials and the third group generated slow waves that consisted of primary and secondary components. Slow waves recorded in different regions of the gastric antrum had similar amplitudes but different characteristic shapes. At the greater curvature, slow waves had large initial components. Midway between the greater and lesser curvature, the amplitude of the initial component was reduced and at the lesser curvature an initial component was difficult to detect. When the distributions of myenteric (ICC-MY) and intramuscular interstitial cells of Cajal (ICC-IM) were determined, using an antibody to Kit, ICC-MY were found to be present at the greater curvature but were greatly reduced in density at the lesser curvature. In contrast, ICC-IM were found in the circular layer of each region. When recordings were made from the antrum of W/W^V mice, which lack ICC-IM, incomplete slow waves were detected and their amplitudes fell from the greater to the lesser curvature. Again, a corresponding fall in the density of ICC-MY was detected. The observations indicate that the contribution of ICC-MY and ICC-IM to the generation of slow waves varies in different regions of the mouse gastric antrum.     

荧光定量PCR快速诊断21三体综合征

目的　建立荧光定量PCR技术检测 2 1三体综合征。方法　采用PCR方法同时扩增位于 2 1号染色体上的人肝型磷酸果糖激酶基因 (humanliver typephosphofructokinasegene ,PFKL CH 2 1)和位于 1号染色体上的人肌型磷酸果糖激酶基因 (humanmuscle typephosphofructokinasegene ,PFKM CH1) ,使用SYBRGreenⅠ荧光染料处理产物、琼脂糖电泳后在凝胶成像系统进行分析 ,得出扩增产物的荧光强度对比值。用此方法检测 2 6例 2 1三体综合征患儿及 2 0名正常人。结果　 2 6例 2 1三体综合征患儿PFKL CH2 1/PFKM CH 1扩增产物的荧光强度对比值为 1.5 8± 0 .17,而正常人为 1 0 0± 0 .0 5 ,两者差异有显著性。结论　SYBRGreenⅠ荧光定量PCR技术检测 2 1三体综合征具有准确、快速、安全、实用等特点 ,有较高的临床使用价值。     

Regional distribution of antibodies to herpes simplex virus type 1 (HSV-1) and HSV-2 in men and women in Ontario,Canada

This study estimated the regional and age- and gender-specific seroprevalences of herpes simplex virus type 1 (HSV-1) and HSV-2 in Ontario, Canada. Stored serum specimens from subjects aged 15 to 44 years, including men (n = 979), women not under prenatal care (n = 638), and women under prenatal care (n = 701) submitted for routine viral serology were randomly selected according to regional population size from public health laboratories. HSV-1 and HSV-2 testing was done with the MRL enzyme immunoassay (EIA) (Focus Technologies), and HSV-2 was also tested by the Gull/Meridian EIA. Specimens discordant for HSV-2 antibodies between the two EIAs were resolved by a recombinant immunoblot assay (Focus Technologies). The overall age- and gender-standardized seroprevalences of HSV-1 and HSV-2 were 51.1% (95% confidence interval [CI], 50.1 to 52.1) and 9.1% (95% CI, 8.6 to 9.7), respectively. The seroprevalence of HSV-1 antibodies increased from 26.9 to 54.7% in men between 15 to 16 and 40 to 44 years of age, from 32.0 to 88.7% in women not under prenatal care, and from 55.2 to 69.2% in women under prenatal care. The seroprevalence of HSV-2 increased from 3.8 to 21.3% in men between 15 to 16 and 40 to 44 years of age, from 0 to 18.9% in women not under prenatal care, and from 3.4 to 23.1% in women under prenatal care. HSV-2 results were discordant for 3.3% (76 of 2,318) of specimens. Both types of HSV antibodies appeared to be acquired earlier among women under prenatal care than among men and women not under prenatal care. Antibodies were more prevalent among people in northern Ontario (72.9% of subjects [range, 68.4 to 77.4%] for HSV-1 and 13.7% of subjects [95% CI, 10.2 to 17.2%] for HSV-2) than elsewhere.     

Epidermal Langerhans' cells in Beh?et's disease.

Langerhans' cells were studied in the epidermis of two patients with active Behçet's disease and compared with those in two normal controls. Ultrastructural morphology and the percentage of Langerhans' cells found were similar in patients' (1.88%) and the control epidermis (1.79%). The density of Langerhans' cells in adjacent sites of the same epidermis was not homogeneous, being in the range of 0.8-2.8% in Behçet's disease and 0.6-4% in the controls. In the controls, Langerhans' cells were distributed unevenly. Some were located near the basal layer of the epidermis while the rest were in the mid and upper layers. In Behçet's disease most Langerhans' cells were in the mid-epidermis, but some were immediately beneath the stratum granulosum. In the Behçet's disease epidermis the area occupied by Langerhans' cells was increased by about 25% and the number of granules found increased by about 44%. It is suggested that in Behçet's disease the Langerhans' cells are in a more active state.     

Mutations in activation-induced cytidine deaminase in patients with hyper IgM syndrome

Recent studies have shown that mutations in a newly described RNA editing enzyme, activation-induced cytidine deaminase (AID), can cause an autosomal recessive form of hyper IgM syndrome. To determine the relative frequency of mutations in AID, we evaluated a group of 27 patients with hyper IgM syndrome who did not have defects in CD40 ligand and 23 patients with common variable immunodeficiency. Three different mutations in AID were identified in 18 patients with hyper IgM syndrome, including 14 French Canadians, 2 Lumbee Indians, and a brother and sister from Okinawa. No mutations were found in the remaining 32 patients. In the group of patients with hyper IgM syndrome, the patients with mutations in AID were older at the age of diagnosis, were more likely to have positive isohemagglutinins, and were less likely to have anemia, neutropenia, or thrombocytopenia. Lymphoid hyperplasia was seen in patients with hyper IgM syndrome and normal AID as well as the patients with hyper IgM syndrome and defects in AID.