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61.
Epidermal growth factor and insulin stimulate nuclear pore-mediated macromolecular transport in isolated rat liver nuclei 总被引:4,自引:2,他引:2 下载免费PDF全文
Fluorescence photobleaching was used to measure the effect of epidermal growth factor (EGF), insulin, and glucagon on the nuclear transport of fluorescent-labeled dextrans across the nuclear pore complex. EGF and insulin were found to stimulate transport approximately 200%, while boiling these polypeptide growth factors greatly diminished this enhancement activity. Glucagon demonstrated no enhancement effect. The nuclear transport enhancement effects were observed at EGF and insulin concentrations that elicit the various physiological responses, e.g., nanomolar range. 相似文献
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63.
我国某些常见化石硅藻的环境分析 总被引:6,自引:0,他引:6
蒋辉 《Acta Botanica Sinica》1987,(4)
本文详细研究了中国海表层沉积物中的常见化石硅藻,结果表明,这些种的分布范围及数量变化随环境的不同而变化。因此,根据柱状样品中这些种类数量的变化,能够推断古气候变化,恢复古地理环境,再现海平面波动历程,进而划分、对比第四系地层。 相似文献
64.
Complementary deoxyribonucleic acid (cDNA) cloning and DNA sequence analysis of rat ovarian inhibins 总被引:7,自引:0,他引:7
F S Esch S Shimasaki K Cooksey M Mercado A J Mason S Y Ying N Ueno N Ling 《Molecular endocrinology (Baltimore, Md.)》1987,1(5):388-396
Two forms of inhibin (A and B), gonadal polypeptide hormones that selectively suppress the secretion of FSH from the anterior pituitary, have been characterized from the porcine and human species, each being composed of a common alpha-chain and one of two distinct, but homologous beta-chains, i.e. alpha beta A and alpha beta B. Using cDNAs encoding the porcine inhibin subunits we have cloned and sequenced the cDNAs encoding the alpha, beta A, and beta B chains of rat ovarian inhibin. Northern analyses of rat testicular RNA with rat ovarian cDNA probes show the presence of mRNAs encoding alpha and beta B chains, but no detectable mRNA encoding the beta A chain under our experimental conditions. This suggests that there may be specific and distinct physiological roles for inhibins A and B. In addition, if there is no extratesticular source of beta A mRNA, then the male rat may be devoid of the stimulators of the secretion of FSH, i.e. activin (beta A beta B) and homoactivin A (beta A beta A), which are derived from the beta subunits of the two inhibins. 相似文献
65.
A radioimmunoassay for human pro-luteinizing hormone-releasing factor [pro-LRF(14-69)OH] 总被引:1,自引:0,他引:1
A Motoyama I Wakabayashi S Minami H Sugihara F Takahashi S Akira N Ling 《Endocrinologia japonica》1987,34(1):133-137
A radioimmunoassay (RIA) for human pro-LRF(14-69)OH was developed with an antiserum, generated in a rabbit, to [Tyr67]pro-LRF(47-67)NH2 conjugated to BSA. This antiserum bound 28-32% of [125I]pro-LRF(14-69)OH at a final dilution of 1:2500 and the binding was inhibited by pro-LRF(14-69)OH in a dose-dependent manner. The sensitivity of the RIA was 31.2-62.5 pg and the dose that inhibited 50% of the binding to the tracer was 280-320 pg. Intra- and inter-assay coefficients of variation at 50% inhibition were 8 and 12%, respectively. Neither LRF nor pro-LRF(14-37)OH was recognized by the antiserum. The dilution curve generated with human hypothalamic extract was parallel to that of pro-LRF(14-69)OH. In addition the extract yielded a major immunoreactive peak emerging in elution volumes concordant with [125I]pro-LRF(14-69)OH on Sephadex G-50 chromatography. 相似文献
66.
Ionizing-radiation-induced damage in the DNA of cultured human cells. Identification of 8,5-cyclo-2-deoxyguanosine. 总被引:1,自引:0,他引:1 下载免费PDF全文
Epstein-Barr-virus-transformed peripheral-blood B-lymphocytes were gamma-irradiated at 0 degree C at doses from 10 to 100 Gy. The cells were immediately lysed and the DNA was isolated. Subsequently, the DNA was hydrolysed to 2'-deoxyribonucleosides with a mixture of DNAase I, venom and spleen exonucleases and alkaline phosphatase. The hydrolysate was dried, trimethylsilylated and analysed by capillary gas chromatography-mass spectrometry with selected-ion monitoring. The (5'R)- and (5'S)-diastereomers of 8,5'-cyclo-2'-deoxyguanosine were observed in a ratio of 1:3, and their formation was dose-dependent. It was possible to detect and characterize one such lesion in approx. 4 X 10(4) guanine nucleotide subunits of DNA. 相似文献
67.
68.
Stefan Einhorn Patrik Ling Nina Einhorn Hans Strander Jerzy Wasserman 《Cancer immunology, immunotherapy : CII》1987,24(3):190-196
Summary The influence of natural -interferon (-IFN) therapy (3×106 units i.m. daily) on blood lymphoid cells was studied in 20 patients with gynecological neoplasias (7 patients with condylomata accuminata and 13 patients with ovarian carcinoma). There was a statistically significant increase in the intracellular levels of 2'–5'oligoadenylate synthese 1 day after the first injection of IFN and with few exceptions this activity remained increased during 3 months of treatment. In most of the patients, the capacity of blood lymphoid cells to produce IgA, IgG, and IgM following stimulation with pokeweed mitogen was decreased 1 day after the first injection of IFN and with few exceptions it remained low during 6 months of IFN therapy. In most patients there was a decrease in the capacity of lymphoid cells to act as stimulator or responder cells in a mixed lymphocyte culture during IFN therapy. The -IFN therapy had no major influence on the response of lymphoid cells to mitogens. We conclude, that neither this nor our previous studies on the influence of IFN therapy on immunological functions have given support to the hypothesis that the antitumor action of IFN is mediated by the immune system. 相似文献
69.
70.
In this paper, we report the effects of laser microirradiation of prophase nucleoli and mitotic chromosomes in cells of female rat kangaroo kidney epithelial cell line PTK1. When the laser power delivered to sample surface was 90-190 mW, irradiation of one of the two nucleoli in the prophase cell did not inhibit the mitotic progress, but resulted in the loss of the irradiated nucleolus in daughter cells. When the laser power was increased to 360-420 mW, either irradiation of the nucleolus or chromosome in midprophase caused a blockage of mitosis at terminal midprophase. The irradiated cells returned morphologically to early prophase. No mitotic reversion occurred in the case of irradiation of chromosomes at late prophase, prometaphase, metaphase, and anaphase. Irradiation of the cytoplasm in prophase cells caused a 50-70 min mitotic delay at prophase. However, the irradiated cells underwent successive mitotic divisions. The mechanism of laser-induced mitotic prophase reversion is discussed. 相似文献