巨细胞病毒肝炎患儿血清细胞因子水平测定及其临床意义

目的　研究巨细胞病毒 (CMV)肝炎患儿血清干扰素 α(IFN α)、白细胞介素 8(IL 8)和肿瘤坏死因子 α(TNF α)水平的变化及其临床意义。方法　应用ELISA法检测 35例CMV肝炎患儿血清中上述三种细胞因子的含量 ,并对其两两之间进行了相关性分析。结果　CMV肝炎组患儿IFN α、IL 8、TNF α的含量分别为 (770 .3± 2 0 5 .4 )ng/L、(41.9± 2 2 .5 )ng/L和 (10 33.2± 388.5 )ng/L ,非常显著高于正常对照组 (P <0 .0 1)。相关性研究发现IFN α与TNF α呈显著正相关 (r =0 .35 6 ,P <0 .0 5 )。结论　血清细胞因子明显增高与CMV肝炎的病理变化和病损程度有着密切的联系     

Excitation of locus coeruleus neurons by an adenosine 3',5'-cyclic monophosphate-activated inward current: extracellular and intracellular studies in rat brain slices

The firing rate of locus coeruleus (LC) neurons in rat brain slices was increased reversibly by agents that either elevate intracellular levels of adenosine 3',5'-cyclic monophosphate (cAMP) or mimic its actions (e.g., forskolin, and activator of adenylate cyclase, 8-Br-cAMP, a membrane permeable analog of cAMP, and Ro20-1724, a preferential inhibitor of cAMP-phosphodiesterase). Intracellular recordings showed that 8-Br-cAMP and forskolin induce a depolarization of LC neurons, accompanied by a decrease in input resistance. The 8-Br-cAMP- and forskolin-elicited depolarization persisted in the presence of cobalt, a calcium channel blocker. Steady-state current-voltage curves revealed that in the voltage range of -50 to -120 mV, 8-Br-cAMP and forskolin induced an inward current, which did not reverse at the potassium equilibrium potential and could not be blocked by tetrodotoxin. Partial replacement of sodium with Tris or choline markedly reduced the depolarization elicited by 8-Br-cAMP. We conclude that 8-Br-cAMP and forskolin act through a common mechanism to increase the firing rate of locus coeruleus neurons by inducing a cAMP-activated inward current, carried out at least in part by sodium ions.     

联合应用纳洛酮与甲基强的松龙对大鼠急性肺损伤的保护作用

目的　探讨联合应用甲基强的松龙、纳洛酮对内毒素所致急性肺损伤大鼠的防治作用及可能机制。方法　建立大鼠内毒素吸入性ALI模型 (LPS ,3mg/kg气管内注射 ) ,85只大鼠随机分为生理盐水对照组、内毒素损伤组、甲基强的松龙组 (内毒素 甲基强的松龙 )、纳洛酮组 (内毒素 纳洛酮 )、联合用药组 (内毒素 甲基强的松龙 纳洛酮 )。采用放射免疫方法检测大鼠血清TNF -α、IL - 8水平 ,并观察动脉血气分析及肺组织病理变化。结果　内毒素损伤组较生理盐水组TNF -α、IL - 8水平明显增高 ,动脉血氧分压明显降低 ,肺组织可见肿胀、淤血、炎细胞浸润。联合用药组各项指标较内毒素损伤组均轻。结论　联合应用甲基强的松龙和纳洛酮可降低气管内注入内毒素致大鼠ALI血清TNF -α、IL - 8升高水平 ,减轻肺损伤病理改变程度 ,对大鼠ALI有防治作用     

Synthesis of CCK-8 Tetrapeptide Fragment by Enzymatic Method

Cholecystokinin (CCK )isa polypeptidehor monecontaining 33aminoacidsresiduewithgastroin testinal,biliarandbrainactivities Itiswidelydis tributedinthevertebratecentralnervoussystem ,anditcanstimulateextensivelytheliberationofinsulinandglucagonfromtheLangerhansislets GreateffortshavebeendevotedtothesynthesisofCCK 8,itsderivativesandanalogues Amongthedifferentmethods ,theenzymaticmethodisthemosteffectiveonewithmanyadvantagesoverconventionalchemicalmethodologies :enzymespecificitysuppress essid…     

实验性大鼠大脑皮层梗死后继发丘脑损害与DNA氧化损伤

目的观察大鼠大脑皮层梗死后丘脑腹后外侧核(ventroposterior nucleus of the thalamus,VPN)的继发性损害是否有DNA氧化损伤,并研究抗氧化剂依布硒啉(ebselen,EB)对这种远隔部位损伤是否具有改善作用。方法采用易卒中型肾血管性高血压大鼠(stroke-prone renovascular hypertensive rats,RHRSP),建立大脑中动脉皮层支闭塞(middle cerebral artery occlusion,MCAO)模型后分为:①假手术组,②模型组,③溶剂组,④抗氧化剂EB10mg.kg-1组,⑤抗氧化剂EB30mg.kg-1组,每组5只大鼠。2周后行肢体运动神经功能评估并取VPN后行尼氏染色,免疫组化检测VPN的8-羟基-2-脱氧马苷(8-hydroxy-2-deoxyguanosine,8-ohdG)表达。结果EB10mg.kg-1组和EB30mg.kg-1组神经功能评分优于假手术组(1.80±0.56,1.72±0.48vs2.28±0.33,P<0.05)。尼氏染色可见假手术组同侧VPN细胞形态规整。而梗死同侧VPN神经细胞出现细胞体积变小,胞核固缩,尼氏体退变为萎缩的深色细胞。EB30mg.kg-1组尼氏染色观察到改善作用。溶剂组同侧VPN的8-ohdG阳性细胞数目(0.1mm2)显著增加(146.8±12.1vs108.4±19.2,P<0.05);与溶剂组相比,EB10mg.kg-1组和EB30mg.kg-1组阳性细胞数目显著下降(123.6±14.7,123.4±17.4vs146.8±12.1,P<0.05)。结论实验性大脑皮层梗死后2周,同侧VPN存在DNA氧化性损伤。抗氧化剂EB对VPN的DNA氧化损伤有抑制作用,并可改善神经功能。     

肺挫伤致肺水肿患者血浆中E-SLT,IL-8,TNF-α和ET-1的变化

目的本研究观察胸部外伤所致肺水肿病人血中E-选择素、TNF、白细胞介素-8和内皮素的变化.方法用固相双夹心酶联免疫吸附法和放免技术共测定了24例胸部外伤病人在治疗前后血中E-选择素、肿瘤坏死因子、白细胞介素-8和内皮素浓度.结果临床肺水肿病人血中E-选择素、肿瘤坏死因子、白细胞介素-8和内皮素的浓度在发病时明显升高,与正常对照组比较,差异有显著性(P＜0.001).治愈后恢复正常,治疗后各项指标与正常对照组比较差异无显著性(P>0.05),但治疗前后差异有显著性(P＜0.001).结论E-选择素、肿瘤坏死因子、白细胞介素-8和内皮素在肺水肿发病机制中起着重要,随着这些因子的升高出现肺水肿并逐渐加重,这些因子降低后肺水肿逐步消失.因此对这些因子的检测有助于估计病情和评价疗效.     

The Protective Role of Glutathione, Cysteine and Vitamin C against Oxidative DNA Damage Induced in Rat Kidney by Potassium Bromate

The roles of glutathione (GSH), cysteine, vitamin C., liposome-encapsulated superoxide dismutase (L-SOD) and vitamin E in preventing oxidative DNA damage and cytotoxicity in the rat kidney after administration of potassium bromate (KBrO₃) to male F344 rats were investigated by measuring 8-hydroxydeoxyguanosine (8-OH-dG), an oxidative DNA product, lipid peroxidation (LPO) levels and relative kidney weight (RKW). Combined pre- and posttreatment of animals with 2 × 800 mg/kg GSH i.p. inhibited the increase of 8-OH-dG, LPO levels and RKW caused by 80 mg/kg KBrO₃ i.p. administration. In contrast, pretreatment with 0.3 ml/kg diethylmaleate (DEM) i.p., a depletor of tissue GSH, was associated with elevation of 8-OH-dG, LPO levels and RKW after a 20 mg/kg KBrO₃ i.p. treatment, which itself caused no change. Administration of KBrO₃ itself reduced renal non-protein thiol levels, but this was inhibited by the two doses of exogenous GSH. Combined treatment with DEM and KBrO₃ lowered the non-protein thiol level in the kidney more than did DEM treatment alone. Protective effects against the oxidative damage caused by KBrO₃ were also observed for pre- and posttreatment with 400 mg/kg cysteine i.p., another sulfhydryl compound, and daily i.g. application of 200 mg/kg vitamin C for 5 days. However, no influence was evident after pre- and posttreatment with 18,000 U/kg L-SOD i.p. or daily i.g. 100 mg/kg of vitamin E for 5 days. The results suggest that intracellular GSH plays an essential protective role against renal oxidative DNA damage and nephrotoxicity caused by KBrO₃.     

Ubiquitous Presence in Mammalian Cells of Enzymatic Activity Specifically Cleaving 8-Hydroxyguanine-containing DNA

Here we report the finding of enzymatic activity that specifically cleaves DNA containing 8-hydroxyguanine (oh⁸Gua) residues in various mammalian cells. To detect this activity, we used a synthetic double-stranded DNA containing a single oh⁸Gua at a defined position as the substrate, and analyzed the products of enzymatic digestion by polyacrylamide gel electrophoresis. Two cleavage sites near the oh⁸Gua residue were detected with partially purified fractions from cow brain and rat liver, and also with preparations from all mammalian tissues examined. These results suggest that enzymatic activity for the removal of oh⁸Gua from DNA is widely distributed in mammalian cells.     

小包装全氟丙烷气体动力学实验研究

为检验塑料小包装全氟丙烷气体（C3F8）在不同包装和储存方法时浓度变化，将装有5～7mlC3F8的聚氯乙烯小袋，根据不同储藏温度和外包装方法随机分成四组：（1）22℃聚乙烯外包装，（2）36℃聚乙烯外包装，（3）22℃铝箔真空外包装，（4）-29℃聚乙烯外包装；每一组C3F8小袋气体存放一定时间后，应用气相色谱分析方法进行浓度测量。结果：第3组C3F8浓度最高和稳定，第2组浓度随放置时间降低最明显，第4组是临床应用气体的储藏和包装方法，其30天样本浓度和第3组相等，但放置一年时浓度降低。结果显示：塑料小包装C3F8予以铝箔真空外包装是一种可行的方法，利于C3F8运输和普及；聚乙烯外包装的C3F8，应放在-29℃保存，时间不超过一年。