共查询到20条相似文献,搜索用时 15 毫秒
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A Hernvann L Cynober C Aussel J Agneray O Ekindjian 《Cell biology international reports》1987,11(8):591-598
We have studied the effects of human, bovine and porcine insulin on sugar transport by cultured chicken embryo fibroblast monolayers. For a 30 min. association time, human and bovine insulin at a concentration of 5.10(-8) M stimulated 2-deoxy-D-glucose uptake. (respectively by an average 58 p.cent and 55 p.cent over basal). Porcine insulin was less potent since a concentration of 5.10(-7) M was necessary to obtain similar stimulation. Moreover, the maximal effect of porcine insulin occur only after 60 min. association time instead of 30 min. for the other peptides. The differences between the effects of insulin from different sources is related to species-dependent differences in their structure. 相似文献
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Electrophoretic characterization of purified bovine, porcine, murine, rat, and human uterine estrogen receptors 总被引:2,自引:0,他引:2
The calf uterine estrogen receptor (E2R) in the presence of sodium molybdate has been purified, 7,000-fold by a single passage over an estradiol affinity column. A dominant 70,000-dalton band and two minor bands at 50,000 and 30,000 daltons were observed by electrophoretic analysis. These bands had been eluted using estradiol, sodium sulfocyanate, CHAPS, and HEPES (pH 7.4) with insulin as a carrier protein. The identities of the protein bands were initially confirmed by their failure to bind the affinity column when saturated with estradiol. This single step purification procedure was reproducible and rapid, with yields of 10-20%, providing 25% purity. Diffusion blot analysis, with specific 35S- and 125I-labeled monoclonal antibodies to E2R, confirmed that the 70,000-dalton band represented the estrogen receptor. Specificity was demonstrated by inhibition of binding of purified E2R by both estradiol and diethylstilbestrol but not testosterone, progesterone, corticosterone, aldosterone, or hydrocortisone. The relative binding affinity of the purified receptor was: ethynyl estradiol greater than 17 beta estradiol greater than estriol greater than or equal to estrone greater than or equal to 17 alpha-estradiol greater than mestranol. Pig, human, mouse, and rat uterine estrogen receptors were similarly purified with the affinity column. As with the calf uterine preparations, a dominant 70,000-dalton band with minor bands at 50,000 and 30,000 daltons was identified by diffusion blot analysis in all the species examined. 相似文献
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World Health Organization International Standard To Harmonize Assays for Detection of Mycoplasma DNA
C. Micha Nübling Sally A. Baylis Kay-Martin Hanschmann Thomas Montag-Lessing Michael Chudy Julia Kre? Ursula Ulrych Stefan Czurda Renate Rosengarten the Mycoplasma Collaborative Study Group 《Applied and environmental microbiology》2015,81(17):5694-5702
Nucleic acid amplification technique (NAT)-based assays (referred to here as NAT assays) are increasingly used as an alternative to culture-based approaches for the detection of mycoplasma contamination of cell cultures. Assay features, like the limit of detection or quantification, vary widely between different mycoplasma NAT assays. Biological reference materials may be useful for harmonization of mycoplasma NAT assays. An international feasibility study included lyophilized preparations of four distantly related mycoplasma species (Acholeplasma laidlawii, Mycoplasma fermentans, M. orale, M. pneumoniae) at different concentrations which were analyzed by 21 laboratories using 26 NAT assays with a qualitative, semiquantitative, or quantitative design. An M. fermentans preparation was shown to decrease the interassay variation when used as a common reference material. The preparation was remanufactured and characterized in a comparability study, and its potency (in NAT-detectable units) across different NATs was determined. The World Health Organization (WHO) Expert Committee on Biological Standardization (ECBS) established this preparation to be the “1st World Health Organization international standard for mycoplasma DNA for nucleic acid amplification technique-based assays designed for generic mycoplasma detection” (WHO Tech Rep Ser 987:42, 2014) with a potency of 200,000 IU/ml. This WHO international standard is now available as a reference preparation for characterization of NAT assays, e.g., for determination of analytic sensitivity, for calibration of quantitative assays in a common unitage, and for defining regulatory requirements in the field of mycoplasma testing. 相似文献
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R S Gray P Cowan U di Mario R A Elton B F Clarke L J Duncan 《BMJ (Clinical research ed.)》1985,290(6483):1687-1691
Sixteen insulin dependent diabetics of long standing, with undetectable fasting plasma C peptide concentrations, and eight non-diabetic controls were each infused intravenously with biosynthetic human and highly purified beef insulin (1 mU/kg/min) while euglycaemia was maintained by a Biostator. No difference was observed between the two insulins in respect of insulin pharmacokinetics or biological action. The diabetics showed appreciable insulin resistance, manifested by a 40% reduction in the rate of insulin mediated glucose disposal, which was unrelated to the presence of insulin antibodies. Insulin binding antibodies, however, increased insulin''s clearance rate and distribution space and prolonged its pharmacological and biological half lives. The rate at which insulin action was lost, after an intravenous infusion, was more rapid in diabetics without insulin antibody binding than in controls. In respect of their influence on insulin pharmacokinetics, moderate concentrations of insulin antibodies may be of positive advantage to all diabetics without endogenous insulin secretion and are not responsible for the insulin resistance of type 1 diabetes. 相似文献
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A method for analysis of the type, purity, and possible structural modifications of insulins of bovine, porcine, and human origin was proposed. It is based on a combination of narrow-bore reversed-phase HPLC and mass spectrometry. The hydrolysis of insulins with highly specific Glu-protease V8 from Staphylococcus aureus followed by peptide mapping of the hydrolysis products and mass spectrometry of the isolated fragments helps rapidly and reliably localize and identify substitutions of amino acid residues in insulin structure by using insulin samples of less than 1 nmol. 相似文献
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N. V. Sergeev I. V. Nazimov V. G. Gavrikov A. I. Miroshnikov 《Russian Journal of Bioorganic Chemistry》2000,26(1):21-26
A method for analysis of the type, purity, and possible structural modifications of insulins of bovine, porcine, and human
origin was proposed. It is based on a combination of narrow-bore reversed-phase HPLC and mass spectrometry. The hydrolysis
of insulins with highly specific Glu-protease V8 fromStaphylococcus aureus followed by peptide mapping of the hydrolysis products and mass spectrometry of the isolated fragments helps rapidly and
reliably localize and identify substitutions of amino acid residues in insulin structure by using insulin samples of less
than 1 nmol. 相似文献
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T Vanha-Perttula 《FEBS letters》1988,233(2):263-267
The seminal plasma of man, boar and bull was found to have a sphingomyelinase (SMase) activity hydrolysing [N-methyl-14C]sphingomyelin. The human and porcine enzymes had an acid pH optimum and were not influenced by divalent metal ions or chelating agents. They were closely similar with the lysosomal enzyme in many tissues. The bovine seminal plasma SMase was partially purified. The enzyme was a glycoprotein with pH optimum at 6.5, a broad pI 4.2-4.8 and molecular mass of 160 and 60 kDa, respectively, in native and SDS-PAGE. The enzyme was activated by Co greater than Mn greater than Cd greater than Ni and inhibited by chelating agents, Cu, Fe, Pb and Zn. The enzyme was clearly distinct from the acid lysosomal SMase and the previously described neutral Mg2+-dependent and independent activities. It had a wide distribution in the bull reproductive tissues. 相似文献
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Optimized method for isolating highly purified and functional porcine aortic endothelial and smooth muscle cells 下载免费PDF全文
Farideh Beigi Mitalben Patel Marco A. Morales‐Garza Caitlin Winebrenner Andrea S. Gobin Eric Chau Luiz C. Sampaio Doris A. Taylor 《Journal of cellular physiology》2017,232(11):3139-3145