Phenotype of endomyocardial biopsy-derived T-lymphocyte cultures and chronic rejection after heart transplantation

Chronic rejection (CR) is a major problem in long-term survival in heart transplantation. We analysed whether the occurrence of CR correlates with the incidence of acute rejections (AR) or with characteristics of endomyocardial biopsy-derived cell cultures. CR was diagnosed by annual angiography and defined as all coronary vascular changes. One year after transplantation 24 of the 63 patients had CR (38%). The incidence of AR in CR + and CR — patients was comparable. The patients in both groups had similar individual median percentages of EMB-yielding cell cultures. During the first year the CR — patients had more cultures in which at least 60% of the cells were CD4 + T cells (50% vs 37%, P = 0.05), due to a stronger CD4 predominance in the first 6 months. In the second year the CD4 predominance in the patients diagnosed as CR + after 1 year tended to be higher (P = 0.08). The patients had comparable percentages of cultures predominated by CD8 + T cells, γδ T cells or NK cells, irrespective of the time interval. These results might indicate that CD4 + T lymphocytes play a dual role in the aetiology of CR.     

DNA探针的高效标记和哺乳动物细胞转化子的检测

本实验采用随机引物法标记探针DNA.探针DNA加热变性成单链,以单链DNA为模板,六聚脱氧核苷酸为引物,在DNA多聚酶I大片段的作用下进行放射性标记.标记探针的比放射性达10~8cpm/μg DNA以上.放射性底物的掺入率为60%.用该方法标记的人高度重复顺序探针,可以检出微微克水平的阳性分子.与人HeLa S_3细胞DNA转化的小鼠LTK~+细胞DNA打点杂交呈阳性,与未经转化的小鼠LTK~-细胞DNA杂交为阴性,证明小鼠转化细胞中存在HeLa细胞DNA,DNA转化是成功的.     

Human immunodeficiency virus (HIV)-related chronic relapsing inflammatory demyelinating polyneuropathy with multifocal unusual onion bulbs in sural nerve biopsy

Summary This is obviously the first report on a case with a spontaneous sensu strictu relapsing variant of human immunodeficiency virus (HIV)-related polyneuropathy. Its manifestation preceded LAS. Intrathecal HIV-antibodies developed between the most severe third and fourth episode. Analysis of sural nerve biopsy was consistent with a multifocally accentuated chronic inflammatory demyelination, characterized by unusual onion bulb-like Schwann cell formations with irregular voluminous layers, electron density, aggregation of filaments, multiple indented nuclei, and numerous enclosed collagen pockets. A direct or immune-mediated indirect specific influence on Schwann cell morphology by HIV might be discussed. Virus-like particles and ultrastructural markers of HIV were not detectable.     

Retinal growth and cell addition during embryogenesis in the teleost, Haplochromis burtoni.

Neurogenesis of the developing embryonic retina is described for the African cichlid fish, Haplochromis burtoni, from 4 days post fertilization until all cell phenotypes are generated (day 7). Cell addition and differentiation both begin at the same absolute location which later becomes the central retina. As observed in most other vertebrates, cones and ganglion cells differentiate first, followed by amacrine and bipolar cells. Rod photoreceptors, which are added late, differentiate last. Changes in retinal thickness, retinal stretching, cell size, and cell density were measured during development. From day 4 through 7, there is an increase in retinal thickness largely due to the expansion of the inner plexiform layer (IPL) and outer nuclear layer (ONL). The inner nuclear layer (INL) decreases in thickness and there is a transient decrease in the density of cells in the scleral portion of the INL. Cells increase in size in the ganglion cell layer (GCL) and the vitread INL, decrease in size in the sclerad INL, and remain the same in the ONL. Changes in the density of the cell layers were observed: the density of ONL cells increased, the density of GCL cells decreased, and INL cells increased then decreased. From day 4 to day 6, eye growth is entirely due to cell addition because no retinal stretching was observed in the ONL or the horizontal layer. During this same developmental period, the pattern and rate of neurogenesis were measured in the differentiated portion of the retina by means of 3H-thymidine labeling. A small number of cell divisions within the differentiated INL precede the onset of cell divisions in the ONL. The number of 3H-thymidine labeled cells within the INL increases at a low rate consistent with an asymmetric pattern of cell division characteristic of stem cells. In contrast, cell divisions in the ONL increase exponentially, consistent with a symmetric pattern of cell division characteristic of progenitor cells. Double-label experiments (3H-thymidine and a rod specific opsin antibody) show that some of the symmetrically dividing cells in the ONL express the rod specific opsin within 2 days, suggesting that these dividing cells are rod progenitors. Although we do not hae conclusive evidence, these developmental processes support the hypothesis that stem cells within the INL could be the source of rod precursors in the embryonic teleost retina.     

Parvalbumin expression reveals a vibrissa-related pattern in rabbit SI cortex

The expression of parvalbumin-like immunoreactivity (PV-LIR) was examined in the mystacial representation within the primary somatosensory cortex (SI) of postnatal day 21 and adult rabbits. PV-LIR was expressed in a prominent vibrissa-like array of patches in layer IV despite the fact that barrels were indistinct in the cytoarchitecture. Each patch consisted of dense terminal-like PV-LIR and a preferential concentration of intensely labeled stellate neurons. Layer V contained scattered small and large intensely labeled basket cells. Layer Vb had a distinct layer of lightly labeled large pyramidal cells that received labeled basket cell terminations. Upper layer VI also contained patches of terminal-like PV-LIR that were in register with the overlying vibrissae pattern. These patches also contained a preferential distribution of labeled non-pyramidal cells as well as modified pyramidal cells. These results suggest that PV-LIR in rabbits delineates cortical modules composed of thalamorcotical afferents and inhibitory local circuits in the absence of a distinct barrel cytoarchitecure. In contrast, prior studies of rat SI cortex have revealed a distinct barrel cytoarchitecture but a uniform distribution of PV-LIR. The differences in PV-LIR between rodents and lagomorphs within the vibrissae representation in SI may be related to species differences in thalamic and local cortical circuits devoted to the whisker sense.     

CD4+CD25+ regulatory T cells: I. Phenotype and physiology

The immune system protects us against foreign pathogens. However, if fine discrimination between self and non-self is not carried out properly, immunological attacks against self may be launched leading to autoimmune diseases, estimated to afflict up to 5% of the population. During the last decade it has become increasingly clear that regulatory CD4⁺CD25⁺ T cells (T_reg cells) play an important role in the maintenance of immunological self-tolerance, and that this cell subset exerts its function by suppressing the proliferation or function of autoreactive T cells. Based on human and murine observations, this review presents a characterization of the phenotype and functions of the Treg cells in vitro and in vivo . An overview of the surface molecules associated with and the cytokines produced by the Treg cells is given and the origin, activation requirements and mode of action of the Treg cells are discussed. Finally, we address the possibility that Treg cells may play a central role in immune homeostasis, regulating not only autoimmune responses, but also immune responses toward foreign antigens.     

人胚额叶皮层和海马干细胞的自主分化研究

目的 研究人胚胎额叶皮层和海马组织神经干细胞的自主分化特性。观察额叶皮层神经干细胞和海马神经干细胞特性的异同。方法 从人胚胎额叶皮层和海马组织分别分离提出神经干细胞，经无血清体外培养、扩增，形成神经球。神经球贴壁进行不加诱导剂的自主分化。采用细胞生长曲线检测神经干细胞的增殖能力。使用5-溴脱氧尿嘧啶核苷（BrdU）标记分裂增生的细胞，观察细胞的分裂增殖情况。免疫细胞化学法鉴定神经干细胞的自主分化能力，比较额叶皮层和海马神经干细胞的分化特点。结果 从人胚胎额叶皮层和海马分离的神经干细胞具有增殖能力，额叶皮层神经干细胞的细胞倍增时间为3．9d，海马神经干细胞的细胞倍增时间为3．2d。细胞贴壁分化后出现Nestin、GFAP、Tuj-1表达阳性的细胞。皮层和海马神经干细胞分化产生的Tuj-1阳性细胞分别是40．7％和19．3％；皮层和海马神经干细胞分化产生的GFAP阳性细胞分别是59．3％和80．7％。结论 分离培养的额叶皮层和海马神经干细胞具有自我更新和增殖能力，可以向神经元、胶质细胞分化。额叶皮层神经干细胞与海马神经干细胞的倍增时问、自主分化特点和分化为神经细胞和胶质细胞的比率各有不同。     

The hevein domain of the major latex-glove allergen Hev b 6.01 contains dominant T cell reactive sites

BACKGROUND: Sensitization to natural rubber latex (Hevea brasiliensis) is a major cause of occupational asthma and rhinitis affecting frequent latex-glove users. Hev b 6.01, a known major latex allergen, is cleaved naturally into hevein (4.7 kDa) and a C-terminal fragment (14 kDa). Hevein is an abundant protein in latex-glove extracts. As the immune response to allergens is initiated by activation of allergen-specific CD4(+) T cells, identification of dominant T cell epitopes is crucial for the development of specific immunotherapy. OBJECTIVE: To identify dominant T cell epitopes of Hev b 6.01 in latex-allergic glove users. METHODS: Ten latex-allergic frequent glove users and six non-latex-allergic atopic control subjects were selected, based on clinical symptoms and positive latex-specific serum IgE. Serum IgE reactivity to glove extract and recombinant Hev b 6.01 (rHev b 6.01) were analysed by ELISA. Latex-specific short-term oligoclonal T cell lines were generated from peripheral blood of latex-allergic subjects. These lines were tested for proliferative responses to overlapping 20-mer peptides of the Hev b 6.01 molecule. CD4(+) T cell intracellular cytokines, IL-4 and IFN-gamma were assessed following stimulation with immobilized anti-CD3 in the presence of IL-2. RESULTS: All ten of the latex-allergic patients showed serum IgE binding to glove extract while eight of these also showed IgE binding to rHev b 6.01 by ELISA. Western blotting confirmed reactivity with rHev b 6.01 at around 20 kDa. T cell proliferation assays showed that latex-specific T cell lines from all subjects responded to one or more peptides, with greatest frequency of reactivity to peptides Hev b 6.01 p(10-29) and Hev b 6.01 p(19-38) in the hevein domain. An allergic-type cytokine profile with considerable IL-4 in addition to IFN-gamma was evident from intracellular cytokine staining. CONCLUSION: Hevein is an important T cell as well as B cell immunogen and contains dominant T cell reactive sites.     

人绒毛膜促性腺激素在脑实质生殖细胞肿瘤诊治中的意义

目的研究脑实质生殖细胞肿瘤(GCT)患者脑脊液和血清中人绒毛膜促性腺激素(HCG)水平变化,评价其在肿瘤诊断、疗效监测中的意义。方法对5例脑实质内GCT患者的脑脊液和血清HCG水平在治疗前后进行系列测定。以10例性别年龄匹配的因其他疾病接受腰穿检查的患者作为对照组,测定其脑脊液HCG水平。观察脑脊液和血清HCG水平在治疗前后的变化情况。结果10例对照组患者的脑脊液中均测不到HCG。从5例GCT患者共采集17对脑脊液和血清配对样本。所有5例患者都出现脑脊液和血清HCG水平升高。治疗后脑脊液和血清HCG水平迅速下降。血清和脑脊液HCG水平呈显著相关。每一对样本中,脑脊液HCG水平均高于血清。血清、脑脊液HCG水平比为0.245±0.190。结论脑脊液HCG升高对诊断脑实质内GCT具有高度特异性和较高灵敏度。对分泌HCG的GCT,脑脊液和血清HCG是评价治疗效果和监测肿瘤复发的重要指标。