单细胞凝胶电泳技术在生殖细胞DNA损伤检测中的应用

单细胞凝胶电泳技术(SCGE)是一种快速检测单个细胞DNA损伤的实验技术,在生殖细胞DNA损伤的检测中广泛应用。本综述系统介绍了SCGE在睾丸生精细胞、支持细胞、间质细胞、卵巢细胞以及卵母细胞等生殖细胞DNA损伤检测中的应用现状,并对SCGE在生殖毒性检测中的发展提出了展望。     

毛细管电泳测定肝癌肝硬化患者血清氨基酸的临床意义

目的　用毛细管电泳的方法测定肝癌肝硬化患者血清氨基酸变化,并探讨其临床意义。方法　用P/ACEMDQ毛细管电泳仪对2 0例正常人、2 0例肝癌患者及2 0例肝硬化患者的血浆游离氨基酸进行测定。结果　在9min内分离12种氨基酸,线性在2 0～10 0 0 μmol/L范围,回收率为77. 5 %～113 .3% ,批内精密度2 . 6 %～11. 4 % ,批间精密度5 . 8%～19. 7%。对结果进行统计学分析,发现肝硬化组酪氨酸、丝氨酸、色氨酸明显升高,丙氨酸明显下降;肝癌组酪氨酸、半胱氨酸、缬氨酸明显升高,脯氨酸明显下降。结论　毛细管电泳测定血浆游离氨基酸对肝癌肝硬化的诊断和治疗有指导意义。     

Culturable and nonculturable bacterial symbionts in the toxic benthic dinoflagellate Ostreopsis lenticularis.

The toxic benthic dinoflagellate Ostreopsis lenticularis hosts a variety of symbiont bacterial flora. Laboratory cultured Ostreopsis clones require the presence of symbiotic Pseudomonas/Alteromonas bacterial strains for growth and toxicity development. Three culturable bacterial strains associated with Ostreopsis were identified as Pseudomonas/Alteromonas strain 1, Pseudomonas/Alteromonas strain 2 and Acinetobacter. Denaturing gradient gel electrophoresis (DGGE) analyses of extracted Ostreopsis associated bacterial DNAs indicated that there were three culturable and four non-culturable associated bacterial strains. The results presented here are the first report of the presence of unculturable bacterial symbionts in a toxic benthic dinoflagellate. Ostreopsis lost toxicity when exposed to elevated temperatures in the field and laboratory culture and subsequently recovered toxicity at reduced temperatures. Ostreopsis associated culturable Pseudomonas/Alteromonas bacterial strains were significantly reduced in dinoflagellate cultures exposed to elevated temperatures. The decreased toxicity of O. lenticularis exposed to elevated temperatures and their subsequent recovery of toxicity in periods of reduced thermal stress may have resulted from the effects of elevated temperature on the spectrum of culturable and unculturable bacterial species interacting with their Ostreopsis host.     

毛细管区带电泳法测定复方马来酸依那普利片中两组分含量

用毛细管区带电泳法同时测定复方马来酸依那普利片中两组分含量。以咖啡因为内标，２０ｍｍｏｌ／Ｌ硼砂—２０ｍｍｏｌ／Ｌ磷酸二氢钠（４９∶５１，ｐＨ８６）为运行缓冲液，在７ｍｉｎ内完成分离。马来酸依那普利和氢氯噻嗪的线性范围分别为８０～６４０μｇ／ｍＬ（ｒ＝０９９９９）和５０～４００μｇ／ｍＬ（ｒ＝０９９９３）。平均回收率分别为１０１０％和１０１１％，ＲＳＤ分别为１０％和１７％，ｎ＝５。     

竹红菌甲素敏化S-180肿瘤细胞膜的光氧化反应及机理探讨

本文研究了竹红菌甲素(简称甲素)对S-180肿瘤细胞膜的作用。结果表明,甲素结合光照可引起S-180肿瘤细胞膜蛋白质交联、脂质过氧化产物MDA含量增加。但在SDS-PAGE分析中观察到的高分子蛋白质交联带并非由MDA所引起。甲素同样可引起小牛胸腺组蛋白光氧化、发生分子交联,并可敏化色氨酸、酪氨酸和组氨酸的无氧化。     

Protein kinase C isozymes that mediate enhancement of neurite outgrowth by ethanol and phorbol esters in PC12 cells

Using PC12 cells to study ethanol's effects on growth of neural processes, we found that ethanol enhances NGF- and basic FGF-induced neurite outgrowth. Chronic ethanol exposure selectively up-regulates δ and ε protein kinase C (PKC) and increases PKC-mediated phosphorylation in PC12 cells. Since PKC regulates differentiation, we investigated the role of PKC in enhancement of neurite outgrowth by ethanol. Like ethanol, 0.3–10 nM phorbol 12-myristate, 13-acetate (PMA) increased NGF-induced neurite outgrowth. However, higher concentrations did not, and immunoblot analysis demonstrated that 100 nM PMA markedly depleted cells of β, δ and ε PKC. PMA (100 nM) also down-regulated β, δ and ε PKC in ethanol-treated cells and completely prevented enhancement of neurite outgrowth by ethanol. In contrast, the cAMP analogue 8-bromoadenosine cAMP did not completely mimic the effectsof ethanol on neurite outgrowth, and ethanol was able to enhance neurite formation in mutant PC12 cells deficient in protein kinase A (PKA). These findings implicate β, δ or εPKC, but not PKA, in the neurite-promoting effects of ethanol and PMA. Since chronic ethanol exposure up-regulates δ and ε, but not βPKC, these findings suggest that δ or εPKC regulate neurite outgrowth.     

鹿茸有效成分对小鼠肝脏RNA和蛋白质合成的影响

多次给小鼠po鹿茸多胺30mg/kg,对[³H]leucine和[³H]uridine掺入肝组织蛋白和RNA有明显的促进作用,而庸茸非多胺则无此作用;当腐胺剂量为21mg/kg时,不仅促进[³H]leucine和[³H]uridiae掺入肝组织蛋白和RNA,也促进[³H]uridine掺入肝细胞核的RNA中,并增强RNA聚合酶的活性;精脒在剂量为8mg/kg时,仅对[³H]leucine掺入肝组织蛋白有促进;而精胺在1mg/kg时,没有观察到上述各种现象。此结果提示,鹿茸多胺类物质是鹿茸中刺激小鼠肝组织蛋白和RNA合成的主要活性物质,这 种刺激小鼠肝组织蛋白和RNA合成效应是由于鹿茸多胺能够显著地增强RNA聚合酶的活性。     

实验性视网膜光化学损伤中的蛋白激酶C

目的：研究实验性视网膜光化学损伤中蛋白激酶C(protein kinase C，PKC)活性的改变；探索地塞米松(dexamethasone，DXM)对视网膜中PKC活性的影响。 方法；48只SD大鼠分为对照组和DXM组，后者于光照前3天开始，连续5天腹膜腔注射DXM 1mg/(kg·d)。经(1 900±106.9)Ix的绿色荧光灯(λ＝510nm～560nm)连续照射24小时后的6小时和1、3、7、14天，进行视网膜PKC活性检测。 结果：光化学损伤后视网膜中的PKC活性在短暂的上升后即出现持续性的下降；DXM对PKC的活性改变无明显作用。 结论：光化学损伤中的视网膜功能障碍可能与PKC活性的持续降低有关。 （中华眼底病杂志，1997，13：78-80）     

Maintenance and synthesis of proteins for an anucleate axon

The anucleate (distal) segment of a crayfish medial giant axon (MGA) remains intact for months in vivo after severing the axon from its cell body, a phenomenon referred to as long-term survival (LTS). We collected axoplasm from chronic anucleate MGAs by perfusing 2-cm lengths of axons with an intracellular saline. This axoperfusate was analyzed by SDS-PAGE and silver stained. Axoperfusate proteins from intact MGAs and from chronic anucleate MGAs exhibiting LTS for up to 6 months were the same. Furthermore, immunoreactive levels of actin and β-tubulin were similar in axoperfusates from intact and chronic anucleate MGAs. This maintenance of proteins in chronic anucleate MGAs must be due to a lack of protein degradation and/or to local protein synthesis by a source other than the cell body. To investigate local protein synthesis in vitro, we added [³⁵S]-methionine to the extracellular saline surrounding intact and chronic anucleate MGAs. After 4- to 6-h incubations, radiolabelled proteins were detected in axoperfusates analyzed by SDS-PAGE and fluorography. The similarity between radiolabelled proteins in axoperfusates and MGA glial sheaths indicated a glial origin for the radiolabelled axoperfusate proteins. Various observations and control experiments suggested that glial-axonal protein transfer occurred by a physiological process. Glial-axonal protein transfer may contribute to the maintenance of proteins during LTS of chronic anucleate MGAs.     

毛细管电泳技术快速检测p53基因点突变

目的：探讨利用毛细管电泳技术快速检测p53基因点突变的临床应用价值。方法：采用毛细管电泳作SSCP分析，检测20例结肠癌肿瘤标本p53基因第7外显子PCR扩增产物，并与传统的聚丙烯酰胺凝胶电泳结果进行比较，最后用DNA序列测定判断其准确性。结果：20例结肠癌标本中，毛细管电泳技术检测出5例标本(Ca4，Ca6，Ca7，Ca8，Ca14)有突变，而凝胶电泳结合银染技术仅检出4例标本(Ca4，Ca6，Ca7，Cal4)有突变，测序证实经毛细管电泳所检出的5例标本均存在点突变。结论：对于PCR产物的单链构象多态性分析，毛细管电泳技术是一种更加快速、简便、敏感的方法，可应用于临床筛查基因点突变。