Parvalbumin immunoreactive neurons and fibres in the teleost cerebellum

Summary The distribution of parvalbumin-(PV) immunopositive cell bodies and fibres in the cerebellum of two species of freshwater teleosts (Salmo gairdneri and Barbus meridonalis) was studied using a monoclonal antibody and the avidin-biotin immunoperoxidase technique. A clear laminated pattern of PV immunoreactivity was observed. After PV-immunostaining, Purkinje cells were strongly labelled in their cell bodies, the initial segments of the axons and the dendritic trees. In the molecular layer, only the dendritic branches of the Purkinje cells were PV-positive. In the granule cell layer, extensive axonal plexuses and scattered cell bodies were observed. Most of the immunopositive perikarya were unequivocally identified as displaced Purkinje cells, whereas a reduced number of smaller neurons with unstained dendrites was also found. Eurydendroid cells, the efferent neurons of the teleost cerebellum, were negative; however, they were impinged upon by numerous PV-positive boutons, corresponding to terminals of Purkinje cell axons. Parallel fibres and climbing fibres, as well as stellate cells and granule cells were negative. Basket cells (or deep stellate cells) whose existence in the teleost cerebellum is discussed, were also not observed. The immunoreactivity distribution pattern for PV in the teleost cerebellum differs from previous observations on the localization of this protein in the cerebellum of amniotes.     

Attempts to make models for Alzheimer''s disease

Profound reductions in cortical acetylcholine levels together with degeneration of cholinergic neurons in the basal forebrain have been reported in patients with Alzheimer's disease. A similar loss of the cholinergic neurons of the basal forebrain and impairment of learning and memory occur in animals injected with a nerve growth factor-diphtheria toxin conjugate, suggesting that this animal model is suitable to analyze cholinergic roles on learning and memory processes, and also the pathogenesis of Alzheimer's disease. In addition, animal models constructed by electrolytic or neurotoxic lesioning of the basal magnocellular nucleus, and models made by transgenetic technology were described.     

人端粒酶逆转录酶在肿瘤免疫治疗中的应用

寻找有效的抗原表位是近期肿瘤免疫治疗的热点．人端粒酶逆转录酶(hTERT)的免疫学特性使其成为肿瘤免疫治疗中一个吸引人的目标。从人和鼠系统获得的数据证实，细胞毒淋巴细胞(CTL)能识别hTERT特异的肽并杀死多种组织类型hTERT表达的肿瘤细胞。由于hTERT在人肿瘤组织中的广泛表达，在极少正常组织的低水平表达，临床试验已开始检验将hTERT作为肿瘤免疫治疗目标的可行程度。近期树突状细胞(DC)转运系统及其相关技术的发展和成熟提供了一个快速有效筛选抗原肽的方法。     

慢性髓性白血病细胞来源的树突状细胞大容量诱导及其功能的实验研究

目的　探索大容量诱导慢性髓性白血病 (CML)细胞来源的树突状细胞 (DCs)的适宜方法 ;研究CML DCs刺激自体T淋巴细胞增殖并分泌γ 干扰素 (IFN γ)的能力。方法　用CS 30 0 0 plus血细胞分离机采集初诊CML病人的外周血单个核细胞 (PBMNCs) ;单采的CML PBMNCS转入组织培养袋 ,加入重组人粒 巨细胞集落刺激因子 (rhGM CSF)和重组人白介素 4 (rhIL 4 ) ,培养诱导 7d ;在诱导前后 ,用流式细胞仪分别检测细胞表面HLA DR、CD1a、CD80和CD86的表达水平 ;用3 H TdR掺入法检测CML DCs和CML PBMNCs刺激自体和异体T细胞增殖的能力 ;用ELISA法检测在自体混合淋巴细胞培养 (MLR)时T细胞分泌的IFN γ浓度。结果　用血细胞分离机收集的CML PBMNCs ,在组织培养袋内经细胞因子培养诱导 ,HLA DR、CD1a、CD80、CD86的表达均有明显上调 ,细胞形态也表现典型的DC特征 ;CML DCs能显著刺激自体和异体T细胞增殖 ,而CML PBM NCs仅能刺激异体T细胞的增殖 ,刺激自体T细胞增殖的能力很弱 ;刺激自体T细胞增殖时分泌的IFN γ浓度 ,CML DCs组为 (877± 2 14 )pg/mL ;CML BPMNCs组仅为 (14± 1.7) pg/mL。 结论　单采的CML PBMNCs转入组织培养袋 ,加入rhGM CSF和rhIL 4 ,可收获大容量的CML DCs;CML DCs在体外具有显著刺激自体T细胞增殖     

表皮生长因子及其受体与流产关系的探讨

采用放射免疫竞争抑制饱和分析法，检测４７例难免流产患者，６５例人工流产及２０例健康非孕妇女血清表皮生长因子（ＥＧＦ）水平；同时采用免疫组织化学法检测流产者胚胎组织中表皮生长因子受体（ＥＧＦＲ）表达程度。结果：人工流产组血清ＥＧＦ水平高于自然流产及非孕妇女，而自然流产与非孕妇女差异无显著性；胚胎组织中ＥＧＦＲ阳性表达率人工流产组明显高于自然流产组。提示：ＥＧＦ通过与其受体结合对妊娠维持、胚胎及胎儿的     

Chronic parasite infection in mice induces brain granulomas and differentially alters brain nerve growth factor levels and thermal responses in paws

Schistosoma mansoni infection, both in humans and in animal models, is known to induce granulomas in the liver and intestine. It has also been reported that in humans the eggs of this parasite can reach the brain, causing psychiatric and neuropathological disorders. Whether this also occurs in rodents is unknown. To answer this question, mice were infected with this parasite and the central nervous system (CNS) examined at various time intervals. The results show that schistosomiasis induced granulomas in several regions of the CNS and increased nerve growth factor (NGF) levels in the cortex, hypothalamus and brain stem, but not in the hippocampus. The infection also caused paw hyperalgesia, as determined by the hot-plate test, and a local increase in NGF, but not in substance P. These findings indicate that the murine model of infection can be used for studying mechanisms leading to human neuroschistosomiasis and suggest that the neuropathological disorders and the sensory deficits observed in human schistosomiasis are associated with impaired levels of NGF in the peripheral and central nervous system. Received: 18 January 1996 / Revised, accepted: 16 April 1996     

CT增强扫描在评价NSCLC血管生成中的临床意义

目的　探讨非小细胞肺癌 (NSCLC)血管内皮生长因子 (VEGF)的表达水平与CT增强程度的关系 ,从影像学角度评价肿瘤血管生成在肺癌诊断、治疗及淋巴结转移中的临床价值。方法　对 30例NSCLC病人进行动态螺旋CT扫描 (SCT) ,测量病灶增强幅度 ,并利用免疫组化技术检测VEGF。对病灶增强值、VEGF阳性表达及淋巴结转移情况进行统计学分析。结果　 30例肺癌病人CT增强值均数为 (36 .2 8± 6 .41 )HU ,VEGF阳性表达 2 1例 ,阴性表达 9例。VEGF在中晚期的阳性表达高于早期病人 (Ρ<0 .0 5) ,淋巴结转移组高于非淋巴结转移组 (Ρ <0 .0 5) ;癌灶增强值与VEGF阳性表达、肿瘤分期及淋巴结转移亦呈正相关。结论　NSCLC的CT增强程度能够反映肿瘤的血管生成 ,并与淋巴结转移密切相关 ,有助于肺癌的诊断、TNM分期 ,而且可以从肿瘤分子生物学行为方面补充目前肺癌分期方法的不足     

Renal regulation of salt balance: a primer for non-purists

The greater than 40-fold range of voluntary salt intake in humans requires corresponding adjustments in renal excretion to maintain balance. Although many mechanisms have been implicated in the regulation of salt output by the kidney, surprisingly little consideration has been given to their quantitative significance and possible interaction. This survey summarizes the effects of changes in glomerular filtration rate, proximal peritubular physical factors, and plasma concentrations of aldosterone and atrial natriuretic factor (ANF), singly and in combination, on the level of salt excretion. Contrary to expectation, even large increases in filtration or decreases in proximal reabsorption have only minor natriuretic effects, due to constancy of fractional reabsorption in downstream nephron segments. Lack of aldosterone release increases salt excretion as much or more than the upstream mechanisms, whereas ANF-induced inhibition of reabsorption in the medullary collccting duct has the largest effect. It may be concluded, therefore, that the potency of these natriuretic factors increases with distance along the nephron, even though each is operating on a progressively small tubular load. However, none of the mechanisms, in isolation, is sufficient to explain salt balance over the range of voluntary intake. Combination of factors demonstrates synergism rather than simple additivity, resulting in more than enough reserve capacity for salt excretion.     

Generation of antigen-specific CD4+ T cell lines from naive precursors

The conditions required for sensitizing naive T cells to nominal antigen are poorly understood. In this report we describe an in vitro system for generating antigen-specific CD4⁺ T cells from previously unprimed individuals. Freshly isolated CD4⁺ T cells were cultured with keyhole limpet hemocyanin (KLH), sperm whale myoglobin (SWM), or human immunodeficiency virus (HIV) gp 160, antigens to which most persons have not been sensitized, in the presence of either dendritic cells (DC) or macrophages (MΦ). In short-term (< 8 days) cultures, CD4⁺ T cells or their CD4⁺, CD45RA (naive) subpopulation mounted significant proliferative responses to KLH, SWM, and HIV gp160, but only if the antigens were presented by DC. In contrast, CD4⁺, CD45RO (memory) T cells responded poorly to these antigens, although they responded vigorously to tetanus toxoid, a recall antigen, presented by either DC or MΦ. KLH- and SWM-specific CD4⁺ T cell lines were established from the starting population that had been sensitized in vitro, following repeated stimulation with antigen and MΦ in medium supplemented with interleukin-2 and interleukin-4. Despite the continued presence of these cytokines during T cell expansion, the expanded lines retained their ability to respond to the priming antigen in the absence of exogenous cytokines. When the CD45RA and CD45RO subpopulations were sensitized and expanded separately, the CD45RA cells alone gave rise to antigen-specific T cell lines, while the CD45RO cells proliferated nonspecifically. These results demonstrate that human naive CD4⁺ T cells can be sensitized in vitro to nominal antigens presented by DC and that the sensitized cells can be expanded into long-term lines that retain their antigen specificity.