Immunological changes among workers occupationally exposed to styrene

The functional status of the immune system was investigated in a group of 71 workers exposed to styrene and in 65 control subjects, recruited according to the same selection criteria and comparable as to sex, age, and confounding variables. Air and biological monitoring were used to characterize styrene exposure (median of the main urinary metabolites in the next-morning spot samples: 106 mg/g creatinine). Phenotypic analysis of peripheral blood lymphocytes (PBL) by automated flow cytometry revealed a reduced proportion of T lymphocyte subsets (CD3⁺, CD4⁺ and CD4⁺45⁺), with no changes in CD8⁺, and a higher proportion of B lymphocytes (CD19⁺) among styrene-exposed workers. The exposed workers showed a higher proportion of activation markers, namely DR and interleukin-2 receptors (CD25). Immunoglobulin subclasses were comparable in the two groups. An increased prevalence of abnormally low values was apparent for CD2⁺, CD3⁺, CD4⁺, CD4⁺45⁺ and CD11b subsets among workers exposed to styrene, whereas CD19⁺, DR⁺ and CD25⁺ showed an increased prevalence of abnormally high values. Natural killer-related phenotypes (CD56⁺, CD56+16⁺, and CD56⁺16^–) were more expressed among styrene workers, with average increase of 30%. However, the frequency distribution of the lytic activity of natural killer cells against K-562 target cells was shifted towards lower values in the exposed workers as compared to control subjects. Dose-response relationships between indices of internal dose and prevalence of abnormal values were detectable for T lymphocyte subsets, NK phenotypes, and activation markers. These findings suggest that moderate exposure to styrene is associated with an altered distribution of lymphocyte subsets. The decreased proportion of T lymphocytes, mainly of T helper-inducer cells, could hamper regulatory functions, thus suggesting a negative modulation by styrene exposure. Since a proper balance between immunocycte subsets is important for immunological responses, such changes should be regarded as adverse effects.     

Lymphocyte stimulation by acetylcholine receptor in polymyositis

Summary Lymphocytes of twenty-seven patients with polymyositis were incubated in vitro with cholinergic receptor rich membranes obtained from the electric organs of Torpedo Marmorata.Lymphocytes of polymyositic patients were slightly stimulated; positive responses were present mainly in patients affected from more than a year. Sensitization against the nicotinic cholinergic receptor may explain the occurrence of the myasthenic syndrome with polymyositis.Fellow of the A. Villa Rusconi foundation     

Measurement of lymphocyte activation by a chromatin topo-optical reaction

Summary A rapid inexpensive method is presented for detecting peripheral blood lymphocyte chromatin activation by the neutral red topo-optical reaction, which causes strong and easily measurable birefringence in the lymphocyte nuclei. This reaction can be enhanced by fixing the cells with 150 mM/l NaCl in 70% ethanol and/or by treating the unfixed cellular suspensions with 0.2 M/l HCl to remove histones. In histone-removed preparations, 30 min DNase I treatment almost completely abolished the birefringent reaction, whereas RNase treatment resulted in only 18% loss.Chromatin activation induced by enzyme inhibition increased chromatin birefringence significantly. The same phenomenon could be induced in sensitive subjects' lymphocytes by specific antigens or haptens much more rapidly. The monocytes were not activated to a significant extent. In non-sensitive subjects different kinetics of antigen or hapten-dependent activation and no cytotoxic effects have been observed. Depletion of T-lymphocytes in vivo in SLE patients or by in vitro treatment with 0.5 mM/l KCN as well as with 0.02% trypsin has caused a significant drop in the mean chromatin birefringence. The effect of trypsin was reversible.     

5-HT2C受体对孵育海马脑片释放分泌型淀粉样前体蛋白的调节

目的考察5-HT_2C受体对孵育海马脑片释放分泌型淀粉样前体蛋白(sAPP)的调节。方法应用5-HT\,特异性5-HT_2C受体激动剂M-110及其特异性拮抗剂L-107孵育海马脑薄片,及Western blot技术和特异性的针对sAPP氨基末端的单克隆抗体22C11检测释放到孵育液中的sAPP。结果5-HT及特异性5-HT_2C受体激动剂M-110在一定的浓度范围内呈浓度依赖性地显著增加sAPP分泌;而特异性5-HT_2C受体拮抗剂L-107在一定的浓度范围内则浓度依赖性地显著抑制sAPP分泌。结论5-HT通过激活5-HT_2C受体调节孵育海马脑片分泌型淀粉样前体蛋白的释放。     

黄芪抗γ射线辐射对小鼠淋巴细胞增殖和IL-2的作用研究

目的 :从免疫学方面探讨中药黄芪对辐射损伤小鼠淋巴细胞增殖和 IL - 2的研究。方法 :用 10 0 %黄芪水浸出液定期给小鼠灌胃 ,行γ线照射后检测小鼠淋巴细胞增殖和 IL - 2的产生。结果 :用药组小鼠脾淋巴细胞增殖和 IL - 2产生有显著增强作用 ,与照射组相比均有非常显著性差异 (P<0 .0 1)。结论 :黄芪有明显抗 γ线辐射、促进小鼠淋巴细胞增殖和IL- 2产生的作用。     

甲醛接触工人的外周血淋巴细胞微核研究

甲醛（ＦＡ）在多种体外诱变测试中呈阳性，啮齿动物吸入甲醛蒸气后引起鼻腔鳞状上皮细胞癌＾（１，２），接触人群的肿瘤发病主有升高趋势，因此对甲醛接触人群进行简单有效的遗传毒理学的生物学监测是十分必要的，本次研究微核测试的结果证实，８０名平均工龄，１２年甲醛接触者的外周血淋巴细胞微核细胞率较对照组有极显著的增加（Ｐ〈０．０１），接触组吸烟人群较对照组吸烟人群的微核细胞率有极明显的增高（Ｐ〈０．０１），接     

罗红霉素对小鼠细胞免疫功能的影响

目的:研究罗红霉素对免疫细胞功能的影响,探讨其除抗菌以外的抗炎和免疫调节作用。方法:将小鼠随机分为阴性对照组、罗红霉素(高、中、低剂量)组和地塞米松组,各组灌胃给药14d后分别采用体外法及体内法测定小鼠脾淋巴细胞转化率。结果:与阴性对照组比较,罗红霉素各剂量组能明显降低小鼠淋巴细胞转化率(P<0.05或P<0.01),体外法和体内法结果相似。结论:罗红霉素可能具有一定的抗炎和免疫调节作用。     

河南省Ⅱ型汉坦病毒基因亚型及其分布的研究

目的查明河南省Ⅱ型汉坦病毒基因亚型的分布情况。方法在河南省汉坦病毒流行严重的地区，捕捉啮齿类动物，以免疫荧光法检测阳性标本，应用汉坦病毒型特异性引物以逆转录，聚合酶链反应方法对抗原检测阳性的鼠肺标本扩增M和S基因片段上的特异核苷酸序列并测序，将扩增片段的核苷酸序列与已知病毒序列进行比较，以明确基因亚型及其地理分布情况。结果褐家鼠、黄胸鼠以及小家鼠携带的病毒均为Ⅱ型汉坦病毒。序列分析发现河南省主要疫区宿主动物问流行的Ⅱ型汉坦病毒至少存在S1、S2和S3三个亚型，其中S1和S3为河南省汉坦病毒的优势流行基因亚型。结论河南省汉坦病毒的亚型较为复杂，地理分布较广。     

Central leptin suppresses splenic lymphocyte functions through activation of the corticotropin-releasing hormone-sympathetic nervous system

Leptin is one of the key afferent signals that regulate food intake and energy expenditure by acting on specific receptors in the hypothalamus. Recently, leptin was reported to activate the peripheral immune system by acting directly on lymphocytes. To elucidate the brain-mediated participation of leptin in the modulation of peripheral immune functions, we examined the effects of intracerebroventricular (icv) injection of murine recombinant leptin on the proliferative response to Concanavalin A (ConA response) of splenic lymphocytes in rats. The ConA response of splenic lymphocytes was markedly reduced 30 min after icv injection of leptin. The suppressive effect of leptin was abolished completely either by surgical severing of the splenic nerves or by icv injection of an antibody against corticotropin-releasing hormone (CRH), but only partially by an anti-urocortin antibody. Icv injection of CRH and urocortin also suppressed the ConA response of splenic lymphocytes, and the effect of urocortin was prevented by the anti-CRH antibody, while that of CRH was not prevented by the anti-urocortin antibody. These results suggest that leptin suppresses peripheral lymphocyte functions, in contrast to the direct activating effects, indirectly through the activation of the CRH (urocortin)-sympathetic nervous system.     

Microanatomical localization of dopamine receptor protein immunoreactivity in the rat cerebellar cortex

Dopamine (DA) receptor subtype localization was investigated in rat cerebellar cortex using immunohistochemical techniques with antibodies raised against D1-D5 receptor protein. A faint D1 receptor protein immunoreactivity was developed in molecular and Purkinje neurons layers. D2 receptor protein immunoreactivity was found primarily in cerebellar white matter followed by molecular and granular layers and Purkinje neurons. Antibodies against D2S receptor protein were localized in molecular layer and to a lesser extent, in granular layer. A few Purkinje neurons displayed a faint D2S receptor protein immunoreactivity. D3 receptor protein immunoreactivity was observed primarily in molecular and in Purkinje neurons layers of lobules 9 and 10. A faint D3 receptor protein immunoreactivity was also localized in Purkinje neurons and to a lesser extent, in molecular and granular layers of cerebellar lobules 1-8. D4 receptor protein immunoreactivity was found in cerebellar white matter. A pale immunostaining was also visualized in molecular layer. D5 receptor protein immunoreactivity was localized primarily in molecular and Purkinje neurons layers and to a lesser extent, in granular layer and in white matter. The above results indicate that rat cerebellar cortex expresses the DA receptor subtypes so far identified. Purkinje neurons, which are the only efferent neurons of cerebellum, are richest in DA receptor protein immunoreactivity. This suggests that dopaminergic neurotransmission may modulate efferent inputs from cerebellum. The localization of the majority of D2 and D4 and of a faint D5 protein receptor immunoreactivity in cerebellar white matter suggests that these receptors may be presynaptic and transported axonally.