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61.
Z H Zhao B Watschinger C D Brown M M Beyer E A Friedman 《Hormones et métabolisme》1987,19(11):534-537
The variations of susceptibility to alloxan induced Diabetes in a total of seventeen rabbits was described. Our study was designed to explore dosage schedules which might improve rabbit responsiveness to and survival after alloxan treatment. A wide range of response to intravenously administered alloxan was observed. Permanent diabetes (blood glucose 350 mg/dl) was found in three rabbits after a single injection (60 mg/kg in one, 100 mg/kg in two). This effect has persisted for eight months. By contrast, two other rabbits injected with a single dose of alloxan (60 mg/kg) developed only transient hyperglycemia. Similarly, four other rabbits either did not respond or had an incomplete response after receiving a total dose of 120 mg/kg. These data suggest that there is extreme variability in individual rabbits susceptibility to the diabetogenic affects of alloxan. 相似文献
62.
Chromogranin A-like proteins in the secretory granules of a protozoan, Paramecium tetraurelia 总被引:2,自引:0,他引:2
J B Peterson D L Nelson E Ling R H Angeletti 《The Journal of biological chemistry》1987,262(36):17264-17267
The ciliate protozoan Paramecium tetraurelia produces secretory granules (trichocysts) which release needle-like structures composed of small, acidic proteins. Using antibodies against isolated chromogranin A (CGA) and against trichocyst proteins, we found cross-reactive proteins in chromaffin granules and trichocysts. Four independently derived sera against isolated CGA stained bands of the Mr 15,000-25,000 family of trichocyst proteins on immunoblots. A positive response was also obtained with antiserum against chemically synthesized peptides (PL26 and GE25) corresponding to defined regions of the CGA amino acid sequence. In extracts of whole Paramecium, larger proteins (Mr 53,000 and 49,000) also reacted with antibodies against CGA and the related synthetic peptides. These larger proteins may represent unprocessed precursors to the smaller proteins of mature trichocysts. Antiserum to trichocysts recognized CGA in chromaffin granule lysates. Further evidence of a Paramecium protein related to CGA was provided by hybridization of Paramecium mRNA with cloned cDNA for bovine CGA. Our results suggest striking conservation in evolution of CGA-like proteins that may play some role, as yet unknown, in secretion. 相似文献
63.
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.
67.
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
68.
Zhao Zikui Li Youheng Institute of Vertebrate Paleontology Paleoanthropology Academia Sinica 《古脊椎动物学报》1987,(4)
<正> Enamel ultrastructures in the molar teeth of the giant panda, including Ailuropoda microta of the Early Pleistocene, Ailuropoda melanoleuca bacont of the Middle and Late Pleistocene and a living form, Ailuropoda rnelanoleuca, have been investigated by scanning electron microscopy. Transverse and longitudinal sections of enamel were made in order co evaluate shape, size and arrangement of the prisms. The sections were etched then with 0.074 M H_3PO_4 for 30-60 sec. Our investigations have shown certain features of the enamel which allow us to recognize differences among Ailuropoda on the basis of examination of large areas of the enamel. The results are summarized below. 相似文献
69.
Scavenging effect of extracts of green tea and natural antioxidants on active oxygen radicals 总被引:14,自引:0,他引:14
With the use of the spin trapping methods, the scavenging effects of the extracts of green tea and other natural foods are studied. In stimulated polymorphonuclear leukocytes (PMN) system, water extract fraction 6 (F6) from green tea and green tea polyphenols (GTP) have the strongest scavenging effect on the active oxygen radicals, much stronger than vitamin C (Vc) and vitamin E (VE). Rosemary antioxidants (RA) and Curcumin (Cur) have weaker scavenging effects than Vc, but stronger than VE. In Fenton Reaction, Cur has the strongest scavenging effect (69%) on hydroxyl radicals. In irradiation, riboflavin system F6(74%) and GTP(72%) have very strong scavenging effects that are weaker than Vc, but much stronger than VE (23%). With the use of spin probe oxymetry, the oxygen consumption in respiratory burst of stimulated PMN were measured when the antioxidants existed in these systems. The results demonstrated that these antioxidants did not affect the respiratory burst of human polymorphonuclear leukocytes stimulated with PMA. 相似文献
70.
Isolation and purification of protein kinase C from human leukemia ML-1 cells phosphorylation of human leukemia RNA polymerase II in vitro 总被引:1,自引:0,他引:1
Protein kinase C (PKC) was purified to near homogeneity from human leukemia ML-1 cells. The purified enzyme showed a single polypeptide band of 80 kDa on SDS-polyacrylamide gel after electrophoresis, and was totally dependent on Ca2+/phospholipid for activity. Diacylglycerol and the tumor-promoting on Ca2/phospholipid for activity. Diacylglycerol and the tumor-promoting phorbol esters stimulated the enzyme activity. Autophosphorylation of PKC purified from phenyl-Sepharose column showed both 80- and 37 kDa polypeptides. Further fractionation of PKC on a hydroxyapatite column revealed two peaks of enzyme activity, indicating that there may be two different forms of protein kinase C present in human leukemia cells. The purified PKC was used to phosphorylate RNA polymerase II of human leukemia cells in vitro and the autoradiogram showed that RNA polymerase II large subunits (240, 220 and 150 kDa) were phosphorylated in a time-dependent manner. 相似文献