NGF prevents the changes induced by monocular deprivation during the critical period in rats

Photic evoked responses were recorded from the striate cortex of Long-Evans hooded intact, monocular visual deprivation (MD) and MD treated with NGF rats. The averaged visual evoked responses (AVER) were obtained from both hemispheres and provided comparison after binocular photic stimuli between the contralateral and the ipsilateral striate cortex with relation to the MD eye. One month of monocular visual deprivation at the critical period of development resulted in marked reduction of the amplitudes of AVER components as compared to the control recordings (P < 0.001). These changes of the AVER could be prevented by NGF infusion to lateral ventricle at the dosage of 2.0–2.4 μg/day for four weeks during the monocular deprivation. In conclusion, the change of AVER amplitudes induced by monocular visual deprivation during the critical period of development can be prevented by NGF infusion to lateral ventricle.     

鼠脾细胞肿瘤坏死因子的诱生和检测

本文报道采用Ｅ．ｃｏｌｉ ＬＰＳ刺激ＡＬＢ／Ｃ小鼠脾细胞诱生ＴＮＦ的最适条件，并用人ＴＮＦ ＥＬＩＳＡ方法检测小鼠ＴＮＦ。结果显示：脾细胞经ＬＰＳ刺激２ｈ就可在上清液中测出ＴＮＦ，１２ｈ达高峰，ＬＰＳ最适刺激浓度为１０＾－２μｇ／ｍｌ，ＴＮＦ产量依赖于脾细胞的浓度。     

Granulocyte-macrophage colony stimulating factor inhibits class II major histocompatibility complex expression and antigen presentation by microglia

Granulocyte-macrophage colony stimulating factor (GM-CSF) modulates various functions of monocytes/ macrophages including antigen-presenting capacity. Recently it was found that astrocytes produce GM-CSF in the central nervous system (CNS) and that GM-CSF can induce proliferation and morphological changes of microglia. Here we show that GM-CSF can down regulate the interferon-γ-mediated induction of major histocompatibility complex (MHC) class II antigens in microglia, but not in astrocytes. GM-CSF pretreatment completely prevents myelin basic protein-specific T cell proliferation induced by microglia but not astrocytes. GM-CSF did not affect the cell surface expression on microglia of either MHC class I or cell adhesion molecules. The inhibition of microglial MHC class II expression and antigen-presenting function is specific for GM-CSF, as treatment with a different CSF (interleukin-3) did not modulate microglial phenotype or functional capacity. These data suggest that GM-CSF might be involved in the regulation of immune responses within the central nervous system.     

乙型肝炎患者可溶性白细胞介素2受体水平变化

本研究应用酶联免疫吸附试验(ELISA)检测了103例乙型肝炎各型患者及26倒乙肝病毒(HBV)携带者血清中可溶性白细胞介素2受体(sIL-2R)水平,并结合临床资料进行分析。结果发现:各型患者及HBV 携带者sIL-2R 水平均明显高于正常对照(P<0.01～0.001),其升高程度与病情轻重呈正比,在去除危重患者酶—胆分离时谷丙转氨酶(ALT)过低的影响后,sIL-2R 水平与ALT 有良好的正相关关系(r=0.38.p<0.05);作者认为sIL-2R 能够较好地反映疾病的活动状况,动态观察血清sIL-2R 水平的变化,对判断和评价HBV 感染后的病情演变及免疫失衡状态具有重要意义。     

中国农村地区5岁以下儿童肺炎死亡社会危险因素研究

目的 调查农村5岁以下儿童肺炎死亡相关的社会危险因素.方法1995年11月—1997年2月在湖北恩施和建始两个贫困地区对5岁以下儿童肺炎死亡的危险因素进行病例—对照研究,死亡病例组226例,肺炎对照组 452例.结果 引起儿童肺炎死亡的社会-经济危险因素有:家庭的人均年收入少于 450元、母亲没有立即带孩子看病的理由是没钱看病或交通不便、家中曾有过一个孩子死亡、家长和村医生的文化程度低、父亲的职业是农民、居室内有火炉、母亲对疾病的认识不够、医生的专业培训不足等.结论 除生物相关因素外,社会危险因素同样是农村5岁以下儿童肺炎死亡的重要因素.它们中某些因素是可以借助对父母的健康教育和急性呼吸道感染病例标准管理而得到控制.     

NGF Augmentation rescues trigeminal ganglion and principalis neurons,but not brainstem or cortical whisker patterns,after infraorbital nerve injury at birth

Prior studies indicate that neonatal nerve injury kills many trigeminal (V) first- and second-order cells, and interrupts pattern formation in the brainstem and cerebral cortex. Yet it is not known whether effects upon cell survival and pattern formation are causally related. To determine whether axotomized V ganglion cells can be rescued by an exogenous trophic agent, rats received 5 mg/kg of nerve growth factor (NGF) prior to, and every day after, infraorbital nerve section on the day of birth until sacrifice on postnatal day (PND) 1, 3, 5, 7, or 14. Other animals received identical lesions without NGF. Ganglion cell numbers were significantly reduced by PNDl in pups not given NGF, while NGF-treated rats displayed no significant cell loss through PND7. However, NGF did not permanently rescue V neurons because ganglion cell numbers were reliably reduced by PND14. Cell numbers in V nucleus principalis were reduced by PNDl in pups not given NGF, while NGF-treated animals displayed no cell loss through PND14. NGF's rescue of second-order cells is probably an indirect effect of NGF actions upon V ganglion cells because, in other newborns, NGF failed to maintain principalis cells after direct lesion of the left V ganglion. To determine whether preventing cell death permits whisker-related pattern formation, other rats also received NGF prior to and after infraorbital nerve section at birth. After 3–14 days, patterns were assessed in the brainstem and cortex with cytochrome oxidase histochemistry and serotonin immunocytochemistry. Whisker-related patterns failed to develop as in cases not given NGF. These data indicate that communication with the periphery is necessary for the maintenance of central whisker-related patterns. They also suggest that V ganglion cells can be rescued, albeit temporarily, from rapid injury-induced death by NGF, thereby delaying injury-induced cell death in nucleus principalis. However, the mechanism(s) responsible for injury-induced pattern alterations in the developing V system remains to be elucidated. © 1993 Wiley-Liss, Inc.     

内皮超极化因子的研究进展

内皮超极化因子（EDHF）是由内皮释放的NO和PGI_2以外的另一种舒张因子,它通过使平滑肌细胞膜超极化而舒张血管,是内皮依赖性血管松驰的第3种重要机制。EDHF可能是花生四烯酸的细胞色素P450代谢产物EET-s,乙酰胆碱、缓激肽等激动剂作用于内皮细胞,使细胞内游离钙浓度升高,合成和（或）释放EDHF,作用于平滑肌细胞膜,激活钙依赖性钾通道,使细胞膜超极化,抑制电压依赖性钙通道的开放,引起血管松弛。在大血管中NO-cGMP松弛机制可能占主导地位,并且抑制EDHF生成;而在阻力小血管,EDHF则可能是引起血管松弛的主要因素。     

心包肽类激素免疫组织化学及免疫电镜的研究

采用免疫组织化学、免疫电子显微镜及高效液相结合放射免疫学方法,研究人和 Wistar 大鼠心包,结果表明:心包组织中存在 ANF 和 AngⅡ样物质。在采用兔抗 ANF 为抗体时,心包组织的间皮细胞存在明显的金粒子标记颗粒,间皮细胞是主要的内分泌细胞。心包组织存在 Ang Ⅱ和3种分子形式ANF.本研究提示.心包除已知功能外,尚存在重要的内分泌功能.     

流行性出血热病毒特异性转移因子的研究

对流行性出血热病毒(EHFV)特异性转移因子(EHFV-TF)的制备、特性及在小鼠体内的活性作用进行了研究。其理化性状与普通 TF 非常相似,能激活淋巴细胞的 E 受体(激活率为65.54%),明显提高 Et-RFC 的形成率。E-HFV-TF 还具有特异性抗原依赖活性:①促进 BALB/C 小鼠和 NIH 裸鼠特异性抗体的产生;②促进 LACA 小鼠脾细胞对 EHFV 反应的特异性应答;③促进脾细胞在 EHVF 存在时对 PHA 诱导下的增殖反应(促时率为151.3%)。EHFV—TF可推迟动物感染 HEFV 后的发病期,延长病程和推迟死亡时间;减轻发病动物脑肺充血、出血、水肿现象和肝肾病理损害程度。结果表明 EHFV-TF 不仅具有提高细胞免疫的非特异活性,而且具有对 EHFV 抗原的依赖活性。本研究提示,E-HFV-TF 可用于 EHFV 感染病人的治疗。