神经肽Y对免疫细胞活性的影响

神经肽Y（NPY）是广泛分布于中枢神经系统和外周神经各部位的神经肽类物质。本实验观察NPY在体外对几种免疫细胞活性的直接作用。结果表明，NPY对小鼠T淋巴细胞丝裂原反应性和NK细胞的杀伤活性均无明显影响（P＞0．05），对巨噬细胞分泌溶菌酶有明显抑制作用（P＜0．05）；而对B淋巴细胞丝裂原反应性则有明显的促进作用（P＜0．05）。上述结果提示，NPY对部分免疫细胞功能的影响因细胞种类而异。     

硒和/或维生素E预防大鼠内皮细胞损伤的实验研究

用含硒（Ｓｅ０．５ｍｇ／ｋｇ）和／或维生素Ｅ（ＶＥ０．６ｇ／ｋｇ）的高脂饲料喂养成年雄性Ｗｉｓｔａｒ大鼠１２周。结果：高脂对照组大鼠血浆前列腺素Ｆｌα（６－酮－ＰＧＦ１α）水平下降，而血清脂质过氧化物（ＬＰＯ）、血浆血栓素（ＴＸＢ２）及内皮素（ＥＴ）水平上升；补Ｓｅ、ＶＥ及Ｓｅ＋ＶＥ可明显降低大鼠血清ＬＰＯ、血浆ＴＸＢ２、ＥＴ及ＴＸＢ２／６－酮－ＰＧＦ１α比值。同时，除了明显提高血浆谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）活力外，血浆６－酮－ＰＧＦ１α浓度明显升高。实验提示，Ｓｅ和／或ＶＥ有调节花生四烯酸代谢及保护内皮细胞的作用。     

Cholera Toxin B-Mediated Targeting of Lipid Vesicles Containing Ganglioside GM1 to Mucosal Epithelial Cells

Purpose. To determine whether the non-toxic pentameric B subunit of Cholera toxin (CTB) binding to ganglioside GM1 on both the lipid vesicles and epithelial cells may provide a means to target lipid vesicles to mucosal cells expressing surface GM1. Methods. Sonicated lipid vesicles containing ganglioside GM1 were prepared. Inter-vesicle cross-linking due to pentameric CTB binding to these GM1 vesicles was determined with a sub-micron particle analyzer. Association of CTB to GM1 vesicles was analyzed with continuous sucrose gradient centrifugation. CTB-mediated binding of GM1 vesicles to human mucosal epithelial cells (Caco-2 and HT-29), mucous membranes of mouse trachea, and nasal tissues were detected with fluorescent labeled vesicles. Results. An increase in lipid particle size due to binding of CTB to lipid vesicles and inter-vesicles cross-linking was detected. At a 30-to-1 mole ratio of membrane-bound GMl-to-CTB, optimum increase in GM1 vesicle aggregation, was detected. Under such conditions, all the added CTB molecules were associated with GM1 vesicles. Time course analysis showed that inter-vesicles cross linking by CTB was detectable within 10 min. and reached a maximum value at 60 min. CTB associated GM1-vesicles bind to mucosal epithelial cells HT-29 and Caco-2 with similar affinity [K_d = 7.8 × 10^–4 M lipid (Caco-2) and 7.6 × 10^–4 M lipid (HT-29)]. GM1 mediated binding specificity was demonstrated by blocking with anti-GMl antibody and the insignificant degree of CTB-associated GM1 vesicle binding to GM1 deficient C6 cells. Conclusions. The CTB-mediated GM1 binding to multiple membrane surfaces provides selective localization of GM1 vesicles to GM1 expressing mucosal cells and tissues. The strategy may be useful in localizing drugs and proteins to gut and respiratory tract mucosa.     

Fas receptor expression on B-lineage cells

Mice homozygous for the lpr mutation have B and T cell defects and develop autoantibodies, suggesting that lpr plays a role in their genesis. The lpr defect has been identified as a mutation in the apoptosis-associated Fas receptor (FasR) gene. To begin to define the role of FasR in B cells, we have surveyed FasR expression on B-lineage cells from early progenitors in the bone marrow through their maturation in the periphery. Contrary to some reports, we found that FasR is expressed on B cells at all stages of their development and is highest on germinal center B cells. FasR is not expressed on lpr/lpr-derived cells. These data are consistent with the idea that lpr/lpr mice have an intrinsic B cell defect that may be manifested in developing as well as peripheral B cells. An unexpected finding is that B-1 (CD5) B cells do not constitutively express FasR: FasR becomes detectable on B-1 B cells only after activation.     

Study of the role of vitamin B12 and folinic acid supplementation in preventing hematologic toxicity of zidovudine

Abstract: A prospective, randomized study was conducted to evaluate the role of vitamin B₁₂ and folinic acid supplementation in preventing zidovudine (ZDV)-induced bone marrow suppression. Seventy-five human immunodeficiency virus (HIV)-infected patients with CD4 + cell counts < 500/mm³ were randomized to receive either ZDV (500 mg daily) alone (group I, n = 38) or in combination with folinic acid (15 mg daily) and intramascular vitamin B₁₂ (1000 μg monthly) (group II, n = 37). Finally, 15 patients were excluded from the study (noncompliance 14, death 1); thus, 60 patients (31 in group I and 29 in group II) were eligible for analysis. No significant differences between groups were found at enrollment. During the study, vitamin B₁₂ and folate levels were significantly higher in group II patients; however, no differences in hemoglobin, hematocrit, mean corpuscular volume, and white-cell, neutrophil and platelet counts were observed between groups at 3, 6, 9 and 12 months. Severe hematologic toxicity (neutrophil count < 1000/mm³ and/or hemoglobin < 8 g/dl) occurred in 4 patients assigned to group I and 7 assigned to group II. There was no correlation between vitamin B₁₂ or folate levels and development of myelosuppression. Vitamin B₁₂ and folinic acid supplementation of ZDV therapy does not seem useful in preventing or reducing ZDV-induced myelotoxicity in the overall treated population, although a beneficial effect in certain subgroups of patients cannot be excluded.     

HBV-M定量检测与HBV-DNA含量水平关系的初步探讨

目的 研究乙型肝炎病毒标志物定量检测结果与其HBV-DNA含量的临床关系。方法 采用时间分辨免疫定量和荧光定量-PCR技术，对HBV-DNA和HBV-DNA含量进行检测。结果 在HBsAg/HBeAg/HBcAb,HBsAg/HBcAb/HBcAb,HBeAg/IC及单纯HBcAb阳性的四个组别中，HBV-DNA阳性率分别是97.17%、30.56%、100%和25%；在HBsAg,HBeAg,HBeAb,HBcAb定量检测高，低值两组HBV-DNA含量对比中，HBV-DNA阳性率分别为76.92%、58.14%；100%、97.26%；20.00%、11.42%；64.62%、27.63%。结论 HBV-DNV比HBV-M更能及时准确反映乙型肝炎病毒感染者的病程情况。     

LightCycler实时监测PCR定量分析血清HBV DNA

目的 检验LightCycler实时监测PCR（real-time detection PCR,RTD-PCR)对血清中HBV DNA定量检测的灵敏性和可重复性，探讨HBV血清标志物与HBV DNA定量的关系。方法 HBV定量按深圳匹基公司乙肝PCR荧光检测试剂盒使用说明，对乙肝标志物已明确的773例血清中HBV DNA定量结果进行统计分析。结果 实时监测PCR对血清中HBV DNA定量检测的灵敏性高，可检测低至1000拷贝／ml血清；可重复性好，批间误差＜20％；各种标志物类型的血清HBV DNA含量分布情况表明，HBV血清标志物中HBeAg与HBV DNA含量有明显的关系，一般HBeAg阳性血清HBV DNA含量较高，但也有相当一部分例外。结论 LightCycler实时监测PCR对血清中HBV DNA定量检测灵敏性高可重复性好；仅根据HBV血清标志物往往不能确定乙肝患者HBV DNA复制水平的高低，HBV DNA定量检测具有十分重要的临床意义。     

Evidence for nitric oxide participation in down-regulation of CYP2B1/2 gene expression at the pretranslational level

Septic or inflammatory stimuli suppress drug metabolism by cytochrome P-450 in the liver, presumably at the pretranslational level. We have shown previously that nitric oxide is responsible at least in part for the inhibition by bacterial lipopolysaccharide of phenobarbital-induced CYP2B1/2 activity in vivo. This was attributed to the interaction of nitric oxide with heme in the active-center of cytochrome P450, leading to enzyme inactivation. Here, we report of nitric oxide with heme in the active-center of cytochrome P450, leading to enzyme inactivation. Here, we report that endogeneous nitric oxide also contributes to LPS-induced suppression of CYP2B1/2 in vivo by down-regulating the expression of CYP2B1/2 protein and mRNA.     

健康人血清叶酸和维生素B_(12)水平的测定

本文对14岁以下健康小儿171名,成人30名及初生儿脐带血30份进行了血清叶酸和维生素B_(12)含量测定,171名小儿于采血前均经补足叶酸和维生素B_(12)。结果:血清叶酸(nmol/L)的正常值低限,<4岁者为6.1,4～14岁为8.4,成人为5.0;血清维生素B_(12)(pmol/L)的正常值低限,<1岁为459,1岁～成人为107。     

核因子-κB与创伤的关系及其在法医病理学中的应用

损伤时间推断是法医病理学的一个研究热点和难点。核因子-κB(NF-κB)是一种核转录调节蛋白,参与多种炎性介质的转录和调控。近年来研究发现NF-κB与机体创伤后的反应密切相关,其在损伤后的时序性表达可望在法医病理学用于损伤时间推断。