Correlation between redistribution of a 26 kDa protein and development of chronic thermotolerance in various mammalian cell lines

Previous studies suggested that a 26 kDa protein might play an important role in protein synthesis-independent thermotolerance development in CHO cells. To determine if this phenomenon was universal, four mammalian cell lines, viz., CHO, HA-1, murine Swiss 3T3, and human HeLa, were studied. Cells were heated at 42 degrees C, and the level of 26 kDa protein in the nucleus was measured, together with clonogenic survival and protein synthesis. The results demonstrated that 1) the 26-kDa protein was present in the four different cell lines, and 2) the level of the 26 kDa protein in their nuclei was decreased by 30-70% after heating at 42 degrees C for 1 hr. However, restoration of this protein occurred along with development of chronic thermotolerance. The protein synthesis inhibitor cycloheximide (10 micrograms/ml) neither inhibited the development of chronic thermotolerance nor affected the restoration of the 26 kDa protein in the nucleus. In fact, this drug protected cells from hyperthermic killing and heat-induced reduction of 26 kDa protein in the nucleus. Heat sensitizers, quercetin (0.1 mM), 3,3'-dipentyloxacarbocyanine iodide (DiOC5[3]: 5 micrograms/ml), and stepdown heating (45 degrees C-10 min----42 degrees C), potentiated hyperthermic killing and inhibited or delayed the restoration of the 26 kDa protein to the nucleus. These results support a correlated, perhaps causal relationship between the restoration of the 26 kDa protein and chronic thermotolerance development in four different mammalian cell lines.     

大兴安岭林区针叶林的生长方程及火灾林木死亡率

本文用随机模拟的方法建立了北方针叶林的生长方程及其受到火灾侵害后的林木死亡率,定量地研究了火灾对这种林分变动的影响．     

LC－CW的抗肿瘤作用及其机理的研究

提取干酪乳酸杆菌细胞壁成分（ＬＣ－ＣＷ）,研究其抗肿瘤作用及其机理。结果表明：１００μｇＬＣ－ＣＷ,ｉｐ,连续４天,可明显抑制小鼠Ｓ１８腹水瘤移植物的生长,抑瘤率为５４％。增强ＩＬ－２诱导的ＬＡＫ杀伤活性,可明显促进小鼠ＮＫ杀伤活性,明显促进小鼠Ｔ细胞转化,促进ＣｏｎＡ和ＰＨＡ－Ｐ诱导的ＩＬ－２产生,促进ＳＩＬ－２Ｒ的减少。研究结果表明ＬＣ－ＣＷ是一种重要的抗肿瘤免疫调节因子。     

A NEW PALEOCENE BIRD FROM ANHUI, CHINA

redspecimenrepersentsanewgenusandspecies.Wanshuinaliigen.etsp.nov.SpecimenShaftofarighthumerus,andthedistalendofaIefttibiotarsusanda1efttarsometatarsus,Vlo529.DistributionQianshan,AnhuiProvince;Paleocene,DoumuFormation.DiagnosisSizesma1l-medium,humeruss1enderandlong,mediancrestventraleelongated,tibiotarsuscompressedanteroposteriorly,externalcondy1eroundinlateraIview,grooveforperoneusprofundusdeepandlong;internalcondylelongerthanex-ternalcondyle,adepressionwelldeve1opedin1owerborder0finter…     

肝胆显像螯合物—氮基三乙酸单酰苯胺及其类似物的合成

本课题合成四个氮基三乙酸单酰苯胺(IDA)类及其类似物肝胆显像螯合物。(1)用家兔做了肝胆显像扫描实验,其显像效果较好。(2)～(3)为未见报道的化合物。     

大鼠肝癌中α_2-巨球蛋白等几种分泌性蛋白基因表达的变化

用Northern blot方法对二乙基亚硝胺所诱发的大鼠肝癌中内源性蛋白酶抑制因子α_2-巨球蛋白(α_2-M)、非特异性免疫抑制剂α_1-酸性糖蛋白(α_1-AGP)及雄性激素正调控的α-2u球蛋白(α-2u)三种分泌性蛋白基因表达情况进行了分析。结果表明在大部分(14/16)肝癌样品中α_2-M RNA水平显著降低;而α_1-AGP RNA水平显著高于正常对照水平;α-2u RNA水平明显下降,但在某些雄性大鼠肝癌样品中该基因却有一定程度的表达。这些结果说明,一些肿瘤宿主血浆中α_2-M水平的显著下降及α_1-AGP水平的明显升高分别是由于基因表达活性的下降及升高所致。α-2u基因表达的异常提示,在癌变过程中机体的内分泌功能发生了某些变化。