Progression of HIV disease is associated with increased expression of FcγRI and CR1 on alveolar macrophages

The expression of receptors for complement and the Fc region of immunoglobulin by alveolar macrophages (AM) constitutes a valuable aid to effector function of these cells. However, during HIV infection such expression may also act to increase binding of immune complexes, thus facilitating viral infection of these cells. This study was designed to determine whether changes in the expression of these receptors occurs in situ during HIV infection. Lung macrophages were isolated by bronchoalveolar lavage in groups of HIV⁺ subjects segregated on the basis of peripheral CD4 count. A group of normal subjects was also investigated. Expression of CR1 and FcγRI was quantified by measuring the optical density of reaction product following controlled immunoperoxidase staining with MoAbs CD35 and CD64. Both CR1 and FcγRI were increased over normal in all HIV⁺ subjects. This increase was progressive with advancing disease as determined by correlation with declining peripheral CD4 count. Comparison of asymptomatic and symptomatic subjects with HIV infection showed no difference in CR1 expression but a rise in FcγRI expression in the latter group. An overall inverse correlation was also found between peripheral CD4 count and FcγRI expression, but not CR1 expression. These data demonstrate a significant increase in the expression of these receptors on AM from HIV⁺ subjects, and show that this increase may occur before any symptoms in these patients.     

Human interdigitating dendritic cells directly stimulate CD40-activated naive B cells

Human interdigitating dendritic cells (IDC) were isolated from tonsils based on their CD40⁺ lineage-negative expression in situ. Isolated IDC displayed a phenotypic profile similar to that of IDC in tonsils and spleen in situ, characterized by high-level expression of major histocompatibility complex class II, the co-stimulatory molecules B7.1 (CD80) and B7.2 (CD86), expression of the late DC maturation marker CD83, and no expression of CD1a, CD13, or CD33. IDC also showed weak nonspecific esterase staining and had the ability to induce an allogeneic mixed lymphocyte reaction. In this study, we further show that in the presence of surrogate activated T cells in the form of CD40 ligation and IL-2, IDC enhance the proliferation of naive B cells and induce their differentiation into plasma cells producing IgM. Evidence for the anatomical co-localization of naive B cells and IDC in the T cell area together with the data obtained in vitro implies a role for IDC in the initiation of the extrafollicular reaction.     

Immunofluorescent detection of anti-cytoskeleton antibodies using vinblastine-treated mononuclear cells

A reliable and reproducible immunofluorescence method is described for the detection of anti-cytoskeleton antibodies in human sera, based on the use of vinblastine-treated peripheral blood mononuclear cells as substrate. Three immunofluorescence patterns associated with antibodies to microfilaments, intermediate filaments and microtubules are readily identified.     

Immunochemical characterization of mouse brain-associated theta (Thy-1) antigen.

The Thy-1 antigens or rat brain and thymus have been isolated and chemically characterized, but those of mice have not been identified. Moreover, it is uncertain whether the antigens are glycolipids or glycoproteins. This study with highly purified preparations of gangliosides GM₁, ¹GD_1a, GD_1b and GT_1b from bovine brain and several ganglioside fractions from mouse brain showed that Thy-1 activity does not reside in gangliosides, but rather in the chloroform-methanol-insoluble residue of brain remaining after extraction of gangliosides. The antigen could be solubilized from this residue with a non-ionic detergent. The antigenic activity of the solubilized preparation was heat-labile but resistant to periodate. The chemical properties of the Thy-1 antigen of mouse brain are discussed.     

供体骨髓细胞输注促进小鼠皮肤移植耐受及其机理的研究

目的　探索“细胞 +环磷酰胺 (cyclophosphamide ,CP)”系统联合抗H 2 b 单克隆抗体、供体骨髓细胞输注诱导移植耐受的作用及其机制。方法　第 0天 ,经尾静脉给C5 7BL/ 6 (H 2 b,B6 )小鼠注入 10 8BALB/c(H 2 d,B/c)来源的脾细胞 ,第 2天 ,腹腔注射环磷酰胺 2 0 0mg/kg ,第 3、5天 ,分别经尾静脉注入抗H 2 b 单抗 ,剂量为 40 0 μg/ 0 .5ml,第 8天进行皮肤移植。皮肤移植后 1周 (第 15天 ) ,输入 2× 10 7供体BALB/c来源的骨髓细胞。观察皮肤移植物存活时间 ,并于第 30天对耐受B6小鼠作混合淋巴细胞反应 (mixedlymphocytereaction ,MLR) ,迟发型超敏反应 (delayedtypehypersensitivity ,DTH)等确定耐受的状态。并通过过继转移实验、嵌合体检查及脾细胞中细胞因子mRNA的表达情况 ,进一步探讨耐受形成的机制。结果　采用此诱导方案 ,B6小鼠对BALB/c小鼠的皮肤移植物长期存活。耐受可以被过继转移 ;耐受小鼠胸腺内的嵌合程度与耐受的维持密切相关 ;TH1型细胞因子在耐受小鼠中明显降低 ,而TH2型细胞因子明显升高。结论　“细胞 +CP”系统联合H 2 b 单克隆抗体、供体骨髓细胞输注能够诱导异基因小鼠皮肤移植耐受。耐受机制与胸腺嵌合体的存在密切相关。克隆无能 (aner gy)、抑制细胞和TH1/TH2偏移在耐受中也     

Magnetic resonance microscopy versus light microscopy in human embryology teaching

A study was carried out on the application of magnetic resonance microscopy (MRM) in teaching prenatal human development. Human embryos measuring 8 mm, 15 mm, 18.5 mm, and 22 mm were fixed in a 4% paraformaldehyde solution and sections obtained with magnetic resonance imaging (MRI) were compared to those prepared for light microscopy (LM), using the same embryos. The MRM and LM slices were of a similar quality. In the MRM sections, embryonic organs and systems were clearly visible, particularly the peripheral and central nervous systems, and the cardiovascular and digestive systems. The digitalization and clarity of the MRM images make them an ideal teaching aid that is suitable for students during the first years of a health-science degree, particularly medicine. As well as providing students with their first experience of MRM, these images allow students to access, at any time, all embryos used, to assess changes in the positions of different organs throughout their stages of development, and to acquire spatial vision, an absolute requirement in the study of human anatomy. We recommend that this technique be incorporated into the wealth of standard embryonic teaching methods already in use.     

COX-2+ myofibroblasts may play a key role in marked stromal fibrosis in strictured colorectal carcinomas

AIMS: To elucidate the mechanism of marked stromal fibrosis in strictured colorectal carcinomas (SC) that cause complete ileus. METHODS AND RESULTS: Sixteen cases of SC and 29 cases of non-strictured colorectal carcinoma (NSC) were studied. These carcinomas showed similar clinicopathological features except for bowel stricture. The stricture index (SI) showing the degree of bowel stricture was 59.8 +/- 12.1% in SC versus 20.8 +/- 24.6% in NSC (P < 0.001). The fibrosis index (FI), defined to reflect the extent of stromal fibrosis, was 56.3 +/- 8.8% in SC versus 21.9 +/- 10.6% in NSC (P < 0.001). COX-2+ myofibroblasts were detected in 13 cases (81.3%) in SC versus eight cases (27.6%) in NSC (P < 0.01). The COX-2+ myofibroblast density was 276.7 +/- 181.1 cells/mm(2) in SC versus 26.6 +/- 52.7 cells/mm(2) in NSC (P < 0.001). When all cases were divided into two groups with and without COX-2+ myofibroblasts, the SI was 48.8 +/- 19.1% in those with COX-2+ myofibroblasts versus 24.8 +/- 29.3% in those with COX-2- myofibroblasts (P < 0.001). CONCLUSION: COX-2+ myofibroblasts may play an important role in extensive bowel stricture in colorectal carcinomas.     

Analysis of the influence of therapy and viral suppression on high-risk sexual behaviour and sexually transmitted infections among patients infected with human immunodeficiency virus in Taiwan

This study examined the effects of certain characteristics of human immunodeficiency virus (HIV)-infected patients related to the risks of practising unprotected sex (UPS) among 919 HIV-infected patients who attended the sexually transmitted disease (STD) clinic of the Taipei City STD Control Center, Taiwan, during the period January–July 2004. After learning that they were HIV-positive, 517 (56%) subjects had practised UPS, 476 (52%) had a new STD diagnosis, and 106 (12%) had used some form of injected drug. UPS was reported by 76% of homosexual/bisexual males, 19% of heterosexual males and 5% of females, and was reported more often by those individuals with casual sexual partners (p < 0.001). According to multivariate logistic regression analyses, UPS was associated with male-tomale sexual intercourse (OR 2.46; 95% CI 1.26–4.86, p < 0.001), with casual sexual partners (OR 2.82; 95% CI 1.62–4.88, p < 0.001), and with an individual's knowledge of his/her HIV status for > 11 years (OR 2.06; 95% CI 1.02–4.18, p < 0.05). Although using anti-retroviral therapy to prevent sexual transmission of HIV is rational, the avoidance of at-risk sexual behaviour should also be a priority among HIV-seropositive individuals. Ongoing risk-reduction counselling related to HIV transmission is needed to reduce certain sexual behaviours associated with HIV transmission.