Increased cyclin B1/CDC 2 kinase activity and phosphorylation of Bcl-2 associated with paclitaxel-induced apoptosis in human nasopharyngeal carcinoma cells

Paclitaxel is a potential cancer chemotherapeutic agent for ovary, breast, and head and neck cancers; its effects on nasopharyngeal carcinoma (NPC) have not been reported previously. This study investigated the cytotoxic mechanism of paclitaxel in two NPC cell lines, NPC-TW01 and NPC-TW04. NPC cells treated with pacli-taxel showed convoluted nuclei, condensed chromatin and decreased cellular and nuclear volume, and also exhibited genomic DNA degradation into multiple oligonucleosomal fragments, suggesting that pacli-taxel induced apoptosis in these cells. The effects of paclitaxel on apoptosis-related proteins including Bcl-2, Bax and CDC 2 were also detected. Although the levels of Bcl-2 and Bax were not changed in NPC cells following treatment with 5 nM-1 μM of paclitaxel, phosphorylation of Bcl-2 was significantly observed in the cells treated with 1 μM of paclitaxel for 12 hours. In addition, cyclin B1-associated CDC 2 kinase was highly activated in the NPC cells exposed to paclitaxel even at low (5 nM) concentration, and this result is associated with the finding that low concentration of paclitaxel is able to induce apoptosis in NPC cells.     

红细胞4．1蛋白与血型糖蛋白C／D结合位点研究进展

红细胞膜骨架与脂双层间存在着相互作用,其中带4.1蛋白与血型糖蛋白C/D间的相互作用对维持正常红细胞的形态和机械稳定性起着重要作用,研究表明,带4.1蛋白在血型糖蛋白C、D上的结合位点分别位于血型糖蛋白C的第82～98位氨基酸残基和血型糖蛋白D的第61～77位氨基酸残基．     

硒对培养人胚肝细胞Ⅲ型前胶原,羟脯氨酸合成的影响

原代培养人胚肝细胞经１．１５６×１０￣(－７）ｍｏｌ／Ｌ硒预处理４ｈ,加入２０ｍｍｏｌ／Ｌ四氟化碳作用２０ｈ,观察硒对其Ⅲ型前胶原（ＰＣⅢ）和羟脯氨酸（Ｈｙｐ）生成的影响。结果培养液中ＰＣⅢ水平、细胞内Ｈｙｐ含量及细胞内外丙二醛（ＭＤＡ）水平均降低,与未加硒对照组比较差别有显著性（Ｐ＜０．０１）。而硒谷腕甘肽过氧化物酶（Ｓｅ－ＧＳＨ－ＰＸ）活性则较对照组显著增高（Ｐ＜０．００１）,且ＰＣⅢ水平与Ｓｅ－ＧＳＨ－Ｐ＿Ｘ／ＭＤＡ比值呈负相关（ｒ＝－０．９１５６,Ｐ＜０．０１）。提示硒可提高Ｓｅ－ＧＳＨ－Ｐ＿Ｘ／ＭＤＡ比值,抑制脂质过氧化激发的肝细胞胶原合成。     

植物种质资源的超低温保存研究进展（综述）

植物种质资源的超低温保存研究进展（综述）殷晓辉,舒理慧（武汉大学生命科学学院,武汉４３００７２）ＡＤＶＡＮＣＥＳＩＮＣＲＹＯＰＲＥＳＥＲＶＡＴＩＯＮＲＥＳＥＡＲＣＨＯＮＰＬＡＮＴＧＥＲＭＰＬＡＳＭ￥ＹｉｎｇＸｉａｏｈｕｉ;ＳｈｕＬｉｈｕｉ（Ｓｃｈｏｏ...     

滇产圆滑番荔枝中的番荔枝内酯

从滇南产的圆滑番荔枝的种子中得到４个番荔枝内酯,４－ｄｅｘｏｘｙｃｈｅｒｉｍｏｌｉｎ－２（１）,ｃｈｅｒｉｍｏｌｉｎ－２（２）,ａｎｎｏｎｉｎＩ（３）和ｄｅｓａｃｅｔｙｌｕｖａｒｉｃｉｎ（４）。其中１为新化合物。     

SCS1, a multicopy suppressor of hsp60-ts mutant alleles, does not encode a mitochondrially targeted protein.

We identified and isolated a Saccharomyces cerevisiae gene which, when overexpressed, suppressed the temperature-sensitive phenotype of cells expressing a mutant allele of the gene encoding the mitochondrial chaperonin, Hsp60. This gene, SCS1 (suppressor of chaperonin sixty-1), encodes a 757-amino-acid protein of as yet unknown function which, nonetheless, has human, rice, and Caenorhabditis elegans homologs with high degrees (ca. 60%) of amino acid sequence identity. SCS1 is not an essential gene, but SCS1-null strains do not grow above 37 degrees C and show some growth-related defects at 30 degrees C as well. This gene is expressed at both 30 and 38 degrees C, producing little or no differences in mRNA levels at these two temperatures. Overexpression of SCS1 could not complement an HSP60-null allele, indicating that suppression was not due to the bypassing of Hsp60 activity. Of 10 other hsp60-ts alleles tested, five could also be suppressed by SCS1 overexpression. There were no common mutant phenotypes of the strains expressing these alleles that give any clue as to why they were suppressible while others were not. An epitope (influenza virus hemagglutinin)-tagged form of SCS1 in single copy complemented an SCS1-null allele. The Scs1-hemagglutinin protein was found to be at comparable levels and in similar multiply modified forms in cells growing at both 30 and 38 degrees C. Surprisingly, when localized either by cell fractionation procedures or by immunocytochemistry, these proteins were found not in mitochondria but in the cytosol. The overexpression of SCS1 had significant effects on the cellular levels of mRNAs encoding the proteins Cpn10 and Mgel, two other mitochondrial protein cochaperones, but not on mRNAs encoding a number of other mitochondrial or cytosolic proteins analyzed. The implications of these findings are discussed.     

A reagentless amperometric electrode based on carbon paste, chemically modified with D-lactate dehydrogenase, NAD(+), and mediator containing polymer for D-lactic acid analysis. II. On-line monitoring of fermentation process

The production of D-lactic acid by Lactobacillus delbrueckii (ATCC 9649) during fermentation was monitored on-line with a reagentless D-lactate dehydrogenase modified carbon paste electrode in a flow injection system integrated with a filtration sampling device. The time delay between sampling and detection was approximately 6 min. The use of an electropolymerized ortho-phenylenediamine membrane on the elctrode resulted in a very selective sensor response with acceptable stability and sensitivity. The D-lactate concentrations determined on-line agreed well with those determined by a standard method, suggesting that this sensor system is suitable for on-line monitoring of fermentation processes. (c) 1995 John Wiley & Sons, Inc.     

RAPD分析─鉴定柑桔体细胞杂种的快速方法

本文利用改进的DNA提取方法,从Volkamer柠檬(Citrus volkameriana Ten. and Pasq.)和酸橙(C. aurantium L.)及其原生质体杂种植株的叶片中抽提总DNA,进行RAPD(Random Amplified Polymorphic DNA)分析。结果表明: 在随机选取的15种引物中,有10种可单独或与其它引物一道鉴定这一组合的体细胞杂种。与形态学性状观察、同工酶及ONA杂交分析等方法比较,RAPD分析是一种可在试管苗期即可直接、准确、快速鉴定柑桔体细胞杂种的方法。     

四川地区幼儿和学龄前儿童的鼻部测量

本文报告１１１６例四川地区幼儿和学龄前儿童（２－７岁）鼻部９项指标的测量均数,性差及年龄发育特点。性差：仅鼻凹鼻底距４－６．５岁等少数指标部分年龄段男女性间出现显著性划异（男＞女）。此外各项指标的绝大多数年龄段男女性间无显著性差异。年龄发育：９项测量指标中７项的生长曲线随年产长而上升,数值随年龄增大,并有１－２个发育高峰;提示鼻部发育具有阶段性;２项指标的曲线随年龄增长变化较小。４项指标男女性的曲     

Changes in cytoplasmic and lysosomal enzyme activities in cultured rat heart cells: The relationship to cell differentiation and cell population in culture

Summary Postnatal rat heart cells in culture enriched with respect to muscle cells were obtained by either high density seeding or by the replating technique. [³H]Thymidine incorporation to DNA and the enzymatic pattern of cytoplasmic and lysosomal enzymes have been studied as a function of the culture’s age, of seeding density, and replating. It was shown that (a) replating maintains predominance of myocyte population for at least 2 wk in culture; (b) heavy seeding density allows homogeneous myocyte population for the 1st wk in culture; and (c) the enzyme profile of the culture may serve as an indicator for the type of cell population in culture and its state of differentiation. This study was done as partial fulfilment of the M.Sc. thesis in Biochemistry (SY). Supported by grants from The Chief Scientist, Ministry of Health, State of Israel; The Ministry of Education and Sciences, State of Niedersachssen (FRG); and The Foundation for Heart Research from Mr. and Mrs. D. Vidal-Madjar, Paris, France.