土壤中含EB病毒诱导物的检测

从广西壮族自治区梧州市、苍梧县、罗城县和北京市收集的土壤标本中发现有EB病毒诱导物。梧州市和苍梧县沿公路和江河两旁桐油树下的土壤标本,对EB病毒早期抗原诱导的阳性率为40～58％。在其他大戟科植物下的土壤标本中,也发现有EB病毒诱导物。对桐油树下土壤中EB病毒诱导物与鼻咽癌发生的可能关系进行了讨论。     

从乙型肝炎病毒表面抗原阳性母亲流产的胎儿查出乙型肝炎病毒标志

应用Southern blot杂交试验检测HBsAg及HBeAg均阳性母亲流产的9例胎儿肝细胞中HBV DNA的存在状态,并与其HBV血清学、免疫电镜及肝脏免疫组织化学的结果相比较。结果在3例胎肝高分子DNA中检出了整合的HBV DNA顺序,且此3例HBV DNA整合到胎肝细胞基因组并无特定部位,提示为随机整合。3例中2例的血清及肝匀浆都检出HBsAg颗粒,其胎肝细胞胞浆HBsAg也阳性;另1例受HBV感染的唯一标志是在胎肝细胞中存在着整合的HBVDNA。此外,另1例则仅胎肝细胞中HBsAg阳性而无整合的HBV DNA。在胎肝细胞中检出整合的HBV DNA进一步证实HBV子宫内传播途径的存在。     

Expression of the adrenergic phenotype by dorsal root ganglion cells of the quail in culture in vitro

From the results of previous studies, we have suggested that "autonomic" cell precursors exist in latent form in sensory ganglia of avian embryos. The potentialities can be expressed when the ganglia are transplanted into a young embryo host. In the present study, we have observed a similar transformation in cultures of dissociated dorsal root ganglia taken from quail embryos of 7-15 days of incubation. From the 4th day of culture onward, numerous adrenergic cells appear. They display tyrosine hydroxylase immunoreactivity, synthesise and store catecholamines and generally differ in size and shape from primary sensory neurons. They and/or their precursors can actively proliferate in culture. The differentiation of these catecholaminergic cells, which can not be detected in quail dorsal root ganglia during normal development in vivo, is dependent on one or more factors present in 9-day chick embryo extract.     

β-decay,Bremsstrahlen, and the origin of molecular chirality

Summary A brief review is presented of the Vester-Ulbricht -decay Bremsstrahlen hypothesis for the origin of optical activity, and of subsequent experiments designed to test it. Certain of our experiments along these lines, begun in 1974 and involving the irradiation of racemic and optically active amino acids in a 61.7 KCi⁹⁰Sr–⁹⁰Y Bremsstrahlen source, have now been completed and are described. After 10.89 years of irradiation with a total Bremsstrahlen dose of 2.5×10⁹ rads, crystallinedl-leucine, norleucine, and norvaline suffered 47.2, 33.6, and 27.4% radiolysis, respectively, but showed no evidence whatsoever of asymmetric degradation.d- andl-Leucine underwent about 48% radiolysis and showed 2.4–2.9% radioracemization. Other samples in solution were too severely degraded to analyze. Probable intrinsic reasons for the failure of the Vester-Ulbricht mechanism to afford asymmetric radiolysis in the present and related experiments involving -decay Bremsstrahlen are enumerated.A portion of this material was presented at the 7th International Conference on the Origins of Life, Mainz, FRG, July 10–15, 1983     

用PO4细胞为靶细胞检测人血清中Epstein-Barr病毒IgA/MA抗体以诊断鼻咽癌

近年来,常用未经丙酮固定的、由丁酸和巴豆油激活的B95-8细胞或P3HR-1细胞为靶细胞,检测人血清中EB病毒IgA/MA抗体以早期诊断鼻咽癌,效果良好。但由于B95-8细胞含有多种EB病毒抗原,不能用丙酮固定,需多次离心沉淀,在浮悬状态下检测,技术比较复杂。     

植物苯丙氨酸解氨酶(PAL)在细胞分化中的作用

烟草、丹参和甜叶菊愈伤组织在分化过程中一般都出现两个PAL活性高峰。第一高峰在培养第一、二、三天中出现;第二高峰在第十一天前后出现。前者在分化或不分化培养基中都存在,似与组织分化无关,后者只在分化条件下才有,似可作为组织启动分化的指示酶。分化程度不同的组织,PAL活性有很大差异,即将或刚分化的组织活性最高,随着分化的进程活性趋于降低,老化的组织甚至丧失活性。PAL活性、木质素合成和管状份子形成之间有着紧密的相关性。     

棘孢小单孢菌和灰色链霉菌原生质体融合的研究

用庆大霉素产生菌——棘孢小单孢菌Micromonospora echinospora 814(Gm~r,Km~r)和链霉素产生菌Streptomyces griseus No. 45(Sm~r,Lm~r)进行了原生质体融合。以抗性为选择标记,选出了融合体。其融合频率在10~(-3)—10~(-4)之间。在电镜条件下,观察了原生质体融合的详细过程,测定了融合体的产抗生素能力,其中一株融合体F106的抗生素产量比亲本菌株814高58％。用羧甲基纤维素薄层对发酵液层析表明,有一个融合体的发酵液比亲本菌株814多一个组份,但没有测出其生物活性。     

微核形成与细胞周期关系的初步研究 Ⅲ.丝裂霉素c诱发人淋巴细胞染色体畸变与不同周期阶段的微核形成

为了研究染色体畸变与微核形成的关系,本实验用不同浓度的丝裂霉素C(MMC,0.025—0.4μg/ml),处理人外周血淋巴细胞,观察中期染色体畸变与不同细胞周期形成的微核间的关系。获得如下主要结果:(1)MMC诱发的染色体畸变细胞率(ACF),未经培养的G_0期淋巴细胞的微核细胞率(NC-MNCF)以及培养的淋巴细胞的微核细胞率(C-MNCF),在一定剂量范围内均呈剂量依赖性增加,并可用幂回归方程描述;(2)微核形成与染色体畸变全然无关的NC-MNCF,和C-MNCF一样,与ACF呈良好的正相关;(3)用胞质分裂阻滞(CB)法,检测MMC诱发的CB-MNCF,较C-MNCF无显著提高,MNCF/ACF的比值较小,并随着MMC剂量增加从0.15左右降到0.03。所有上述结果表明,不能简单理解微核形成与染色体畸变间的关系,在分裂的细胞群体中,中期染色体畸变可能仅是微核形成的一种来源。