Effect de la Substitution de D2O à H2O sur L'altération de la Myosine B en Solution par la Chaleur et par les Rayons γ du 60Co

Summary

(1) Cette étude montre que les altérations de la myosine B provoquées par la chaleur et par l'irradiation aux rayons γ sont—telles qu'elles apparaissent à l'ultracentrifugation analytique—qualitativement semblables.

(2) Nous avons observé un effet isotopique considérable de la présence de 75 pour cent de D₂O dans le solvant sur la sensibilité de la myosine B envers ces deux agents, et nous avons présenté une tentative d'explication de ce fait.

(3) Les polymères qui apparaissent après un traitement par la chaleur de la myosine B semblent être d'une nature très différente des polymères que l'on voit apparaître après un traitement identique de la myosine A. Ceux obtenus à partir de la myosine B sont dépolymérisables par l'intermédiaire de l'ATP et ils apparaissent dans une zone de température beaucoup plus étroite que celles de la myosine A. Ce dernier fait indique une différence considérable de l'enthalpie d'activation des deux réactions.     

MDQ治疗MAIDS机制研究

目的HIV(humanimmunodeficiencyvirus)感染成为一个世界性的难题,中医中药具有几千年与感染性疾病作斗争的经验。目前,在高效抗逆转录病毒疗法(highlyactiveantiretroviraltherapy,HAART)具有的局限性日渐清晰的形势下,从植物药中寻求可以治疗HIV感染以及改善预后的药物和有效成分成为现实的需要。本实验以Friend病毒感染的Balb/C小鼠为模型,以AZT(齐多夫定)作为阳性对照药物,探讨中药毛冬青提取成分对小鼠逆转录病毒感染的作用及其初步的机制。方法以FLV感染Balb/C小鼠,随机分为AZT组、模型组、MDQ大剂量组、MDQ中剂量组、MDQ小剂量组,给药三周后,摘眼球处死小鼠,血抗凝处理,以流式细胞仪检测CD4T、CD8T计数,并计算比值;称取鼠重、脾重,计算脾指数;鼠脾以10%甲醛固定后,HE染色,切片观察。结果AZT组和MDQ大剂量组,脾指数明显小于模型组,其中AZT具有显著性差异,MDQ大剂量组有差异,CD4T/CD8T比值,AZT组与MDQ大剂量组与模型组有显著性差异,此结果与病理片观察一致。结论MDQ具有抗FLV所引起的小鼠脾大症和免疫缺陷...     

星形细胞瘤FLI-1蛋白表达及其与病人预后的关系

目的 探讨星形细胞瘤Friend白血病整合素1转录因子（FLI-1）表达水平及其与病人预后的关系。方法 选取2015年6月~2018年6月手术切除的术后病理检查确诊的星形细胞瘤标本112例和颅脑损伤内减压术获得非肿瘤脑组织59例（对照组）,采用免疫组织化学染色法检测FLI-1表达情况。术后随访3年,记录无进展生存、总生存情况,其中无进展生存为预后良好,肿瘤进展或病人死亡为预后不良。结果 112例星形细胞瘤中,预后良好62例,预后不良50例。星形细胞瘤FLI-1表达阳性率[66.96%（75/112）]明显高于对照组[16.95%（10/59）;P<0.05]。星形细胞瘤FLI-1表达与IDH1表达呈明显负相关（r=-0.682,P<0.001）,与p53表达呈正明显相关（r=0.711,P<0.001）。多因素logistic回归分析显示FLI-1表达阳性是星形细胞瘤预后不良的独立危险因素（OR=3.758 ;95% CI 1.439~9.814 ;P=0.009）。生存曲线分析显示,FLI-1表达阴性病人3年累积无进展生存率（75.68%）、3年累积总生存率（81.08%）均明显高于FLI-1表达阳性的病人（分别为45.33%、49.33%;P<0.05）。结论 星形细胞瘤FLI-1呈高表达,与病人的不良预后有关。     

Early dissemination rates of Friend murine leukaemia virus variants correlate with late pathogenesis

FIS-2, a less oncogenic, immunosuppressive variant of the Friend murine leukaemia virus (F-MuLV), was used to explore whether the differences in biological features were related to early virus dissemination rates or sites of replication. We found that erythroblasts were the primary target cells for both F-MuLV and FIS-2, while B- and T-cells were infected later in the infection. Although FIS-2 replicated to similar titres as F-MuLV, we observed a delay in peak viraemia titre and in the number of virus-positive cells in bone marrow and spleen. Studies including the chimeric viruses RE3 (FIS-2LTR with a F-MuLV background) and RE4 (F-MuLV LTR with a FIS-2 background) indicated that the delay in dissemination was due to mutations in FIS-2 LTR. The kinetics for early virus replication correlated with previously reported mean latency time for virus-induced erythroleukaemia in mice inoculated as newborns and with the onset of immunosuppression in adult mice. In addition, F-MuLV-induced late immunosuppression coincided with signs of erythroleukaemia and persistent viraemia. FIS-2 induced a more moderate late immunosuppression without persistent viraemia or signs of erythroleukaemia. Overall, our findings indicated that early viral replication is a prognostic factor in murine retrovirus-induced pathogenesis.     

灵芝孢子油体内抗 Friend 鼠白血病病毒的实验研究

目的 探讨灵芝孢子油体内抗 Friend 鼠白血病病毒 (Friend murine leukemia virus, Fr.MuLV) 感染的疗效和作用机制。方法 用 Fr.MuLV 感染 BALB/C 雌性小鼠,造模小鼠 ig 给药 21 d,比较各组动物的体质量、脾指数、胸腺指数,CD4+、CD8+、CD4、+/CD8+ 等指标变化情况。结果 小鼠感染 Fr.MuLV 后体质量严重减轻,脾明显肿大,胸腺萎缩,CD4+、CD8+、CD4+/CD8+值均显著降低。灵芝孢子油 50、100、200 mg/kg 剂量均可显著改善体质量增长抑制、脾肿大及胸腺萎缩 (P＜0.01),100、200 mg/kg 剂量组 CD4+、CD8+、CD4+/CD8+ 值均有明显升高(P＜0.01、0.05)。结论 灵芝孢子油对 Fr.MuLV 感染小鼠有保护作用,能够改善体质量增长抑制,抑制脾肿大及胸腺萎缩,升高感染小鼠的 T 淋巴细胞。     

Adolescent stigma towards drug addiction: Effects of age and drug use behaviour

The objective of this study was to examine adolescent age and experience with drug use on stigmatizing attitudes toward drug addiction. Data were derived from the  2005 cycle of the Ontario Student Drug Use Survey. In total, 4078, 7- to 12-graders completed self-administered questionnaires that included a measure of drug abuse stigma. Results indicated that stigma scores were higher among younger than older adolescents, and the decline across age was robust, occurring among both males and females and those from rural and non-rural areas. The decline, however, was stronger among non-drug users and among those who had no close friends that use drugs. Despite the age-related decline, the level of stigma in general suggested that drug abuse stigma may continue into adulthood. Findings highlight that individual attitudes toward drug use and drug abusers are salient factors for personal drug use. Given that stigma is a barrier to treatment, but reduced stigma may encourage greater adolescent use, this study highlights the need for more in-depth studies of drug stigma.     

Studies on the resistance of the C 57 Bl/6 mouse strain to the polycythemia-inducing strain of the Friend virus (FV-P)

Summary In previous studies it had been found that C 57 Bl/6 marrow cells, normally resistant to infection by the Friend virus (FV-P), became susceptible after their transplantation into lethally irradiated leukemic DBA/2 mice. This loss of FV-P resistance was further analyzed and spleen weight and the number of erythropoietin-(Ep)-independent CFU-E in bone marrow and spleen were measured as the result of successful FV-P infection. C 57 Bl/6 marrow was infected shortly before and in intervals after either isogeneic transplantation or transplantation into lethally irradiated DBA/2 hosts. After isogeneic transplantation there was some susceptibility for FV-P and this seemed to correlate with the regenerative activity of BFU-E at the time of infection. However, there was no difference in the BFU-E kinetics between normal DBA/2 and C 57 Bl/6 mice. C 57 Bl/6 were further pretreated by bleeding, irradiation with 150 R, injection of hydroxyurea and of endotoxin. After hydroxyurea treatment there was an increased proportion of BFU-E in S-phase, but only endotoxin, which did not alter the BFU-E kinetics after 48 h, made C 57 B1/6 mice susceptible to FV-P infection. These results suggest that the proliferative activity of BFU-E might be important for successful FV-P infection and induction of Ep-independent erythropoiesis but also other conditions regulate the resistance or susceptibility of a mouse strain.Supported by the Deutsche Forschungsgemeinschaft (SFB 112) and Stiftung Volkswagenwerk