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1.
Radioactive mestranol (ME) and/or ethynylestradiol (EE) were administered to women in Nigeria, Sri Lanka, and the USA, and the types and patterns of radioactive urinary conjugates examined by Sephadex LH-20 chromatography. There are no differences in the total excretion of urinary radioactivity over 3 days. Consistent geographic differences appear to be present in the proportion of 3-, 17-, and 3,17-glucuronides. If confirmed on larger population samples, these observations may indicate significant geographic differences in the hepatic metabolism of ethynyl estrogens.High performance liquid chromatographic patterns of the urinary aglycone metabolites of ME and EE were examined in a number of women. The separation was accomplished on a Chromegaprep Diol column with a gradient of isopropanol in heptane. Ethynyl estrogen metabolism shows considerable individual variation. EE is usually the principal compound excreted following ME or EE administration. Unmetabolized ME is present in the ME profiles. The profiles of EE and ME are similar, with EE demonstrating a more complex pattern. Oxidative metabolism occurs chiefly at positions 2, 6, and 16 and is fairly extensive in the USA subjects. The Sri Lankan women generally show less of the oxidative products and the Nigerian group display a notable lack of oxidative metabolism. There is no difference in the metabolic patterns of long-term oral contraceptive users vs. non-users. Using silver sulfoethylcellulose column chromatography, from 14.1 to 34.7% of the excreted radiolabeled aglycones are non-ethynyl (i.e., either D-homo or de-ethynylated estrogens).  相似文献   

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Radiolabeled GABA and glutamate transport into 7 day, 14 day and adult cortical nerve ending preparations was examined. Transport was measured at several Na+ concentrations, 19, 27, 43 and 121 mM, and at two temperatures, 15 and 30°C. Km and Vmax values were calculated for all experimental conditions by means of Wilkinson (1961) analysis. A comparison of the day 14 and adult data shows higher Km values at all Na+ concentrations on day 14 for both GABA and glutamate transport. In addition, the temperature dependence of transport was attenuated in the day 14 preparation. Finally, the specificity of GABA transport, as measured by the use of the transport inhibitors β-alanine and 2,4-diaminobutyric acid, was not different between the day 14 and adult preparations. Overall, it is concluded that both GABA and glutamate transport into day 14 nerve endings behave as if “adult” transporter molecules were existing in a more fluid lipid environment, which is the situation found in synaptic membranes prepared from day 14 nerve endings (Hitzemann and Johnson, 1983).Glutamate and GABA transport into 7 day nerve endings is complex and shows marked differences from the day 14 and adult data. Day 7 GABA transport was significantly more sensitive to β-alanine inhibition. Day 7 transport was more sensitive to Na+ manipulation and the temperature dependent kinetics show unique Na+ effects not seen in the day 14 or adult preparations. For example, at 19 mM Na+, 7 day glutamate transport was more temperature dependent than adult transport but as the Na+ concentration was increased the reverse was true. The opposite situation for temperature-Na+ effects was seen for GABA transport. Finally, no Ca+2-dependent component of GABA release could be found in 7 day nerve endings while a significant component was found at day 14. Overall, it is concluded that both glutamate and GABA fluxes in 7 day nerve endings differ both qualitatively from that seen in both day 14 and adult nerve endings.  相似文献   

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Lymphoid cell subclasses in rejecting renal allograft in the rat   总被引:4,自引:0,他引:4  
We have quantitated the frequency of lymphoid cell subsets in rejecting renal allografts and in the spleen of the allograft recipient during drug-unmodified rejection in the rat. The number of inflammatory (white) cells in the graft was approximately similar to the number of white cells responding to the allograft in the recipient spleen. The inflammatory population of the graft consisted of lymphoid cells and mononuclear phagocytes, with increasing numbers of macrophages toward the end of rejection. Analysis of allograft cellular dispersates with monoclonal antibodies directed to the lymphoid cell subsets demonstrated that although the majority of allograft-infiltrating lymphocytes were T cells, a sizable B-cell proliferation and immunoglobulin synthesis was associated with the inflammatory response of rejection. Within the T-cell subset, the T suppressor/killer cells predominated in the graft whereas the predominant lymphoid cell subset responding to the allograft in the recipient spleen was the T helper cell.  相似文献   

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Experiments were carried out to study the repair capabilities of normal human cervical fibroblasts and fibroblasts derived from human uterine cervical dysplasia, carcinoma in situ and invasive carcinoma. Sedimentation analysis of DNA in alkaline sucrose density gradient was carried out to monitor the DNA damage induced by a methylating carcinogen, methylnitrosourea (MNU). The results indicate that none of the cell lines, namely, fibroblasts either derived from normal human uterine cervix (T30-11) or from cervical cells of cancer precursor lesions (T4-3F; T23-3; T18) exhibited any significant repair in 72 h. In contrast fibroblasts derived from normal human skin (GM105) exhibited 38% repair of their DNA damaged by MNU. Epithelial-like cells (T4-3E) obtained from cervical dysplasia exhibited only 18% repair of MNU-induced DNA damage in 72 h.When the damage was induced by another methylating agent, methyl methanesulfonate (MMS), fibroblasts from normal human skin (GM105) exhibited 40% repair of the damaged DNA whereas fibroblasts from normal human uterine cervix (T30-11) exhibited only a 16% repair, in 72 h.These results suggest that fibroblasts derived from either normal human uterine cervix or from cervix with cancer precursor or cancer lesions exhibit low levels of repair of DNA damged by methylating agents.  相似文献   

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The respective contribution of the anterior (AP) and the neuro-intermediate (NIL) lobes of the pituitary gland to changes occuring in plasma β-endorphin (β-EP) and β-lipotropin (β-LPH) titers has been evaluated in the rat after administration of serotonin (5-HT)-acting drugs. β-EP-like immunoreactivity (β-EP-LI) was concurrently evaluated in the mediobasal hypothalamus (MBH). The administration of 50 mg/kg DL 5-hydorxytryptophan (5-HTP) or 12.5 mg/kg fluvoxamine, a 5-HT reuptake blocker, decreased markedly β-EP-LI in the AP and induced a striking rise in plasma β-EP and β-LPH concentrations. Combined administration of fluvoxamine and 5-HTP failed to potentiate the effect of individual treatments. Similarly, administration of 5.0 and 10 mg/kg quipazine, a 5-HT receptor agonist, evoked a marked decrease in β-EP-LI in the AP and a concomitant rise in β-EP and β-LPH concentrations in the plasma, while administration of 1.0 and 5 mg/kg of chlorophenylpiperazine, a weak 5-HT stimulant drug, did not alter the above indices. None of these treatments altered significantly β-EP-LI in the NIL and only the higher dose of quipazine increased it in the MBH. We conclude that brain serotonin neurons exert a stimulatory influence on β-EP and β-LPH release from the AP but, likely, not from the NIL and that hypothalamic endorphins are not implicated in the secretory events occuring at AP level after acute activation of 5-HT neurotransmission.  相似文献   

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This study deals with the synthesis of benzophenone sulfonamides hybrids (131) and screening against urease enzyme in vitro. Studies showed that several synthetic compounds were found to have good urease enzyme inhibitory activity. Compounds 1 (N′-((4′-hydroxyphenyl)(phenyl)methylene)-4′′-nitrobenzenesulfonohydrazide), 2 (N′-((4′-hydroxyphenyl)(phenyl)methylene)-3′′-nitrobenzenesulfonohydrazide), 3 (N′-((4′-hydroxyphenyl)(phenyl)methylene)-4′′-methoxybenzenesulfonohydrazide), 4 (3′′,5′′-dichloro-2′′-hydroxy-N′-((4′-hydroxyphenyl)(phenyl)methylene)benzenesulfonohydrazide), 6 (2′′,4′′-dichloro-N′-((4′-hydroxyphenyl)(phenyl)methylene)benzenesulfonohydrazide), 8 (5-(dimethylamino)-N′-((4-hydroxyphenyl)(phenyl)methylene)naphthalene-1-sulfono hydrazide), 10 (2′′-chloro-N′-((4′-hydroxyphenyl)(phenyl)methylene)benzenesulfonohydrazide), 12 (N′-((4′-hydroxyphenyl)(phenyl)methylene)benzenesulfonohydrazide) have found to be potently active having an IC50 value in the range of 3.90–17.99?µM. These compounds showed superior activity than standard acetohydroxamic acid (IC50?=?29.20?±?1.01?µM). Moreover, in silico studies on most active compounds were also performed to understand the binding interaction of most active compounds with active sites of urease enzyme. Structures of all the synthetic compounds were elucidated by 1H NMR, 13C NMR, EI-MS and FAB-MS spectroscopic techniques.  相似文献   

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An inhibitor present in placenta and released in placental tissue culture forms specific complexes with each of two molecular forms of urokinase. Audoradiography demonstrated that the inhibitor shifted the electrophoretic position of 125I-labelled urokinase. It did not change the migration of diisopropyl-fluorophosphate-inactivated 125I-labelled urokinase, thereby indicating complex formation dependent on active serine site in urokinase. The inhibitor had a strong neutralizing effect on the plasminogen activators released from human ovarian carcinoma in tissue culture. The placental inhibitor might prove useful in inhibiting the fibrinolytic process necessary for proliferation of tumour vessels.  相似文献   

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In previous studies it was found that change in the concentrations of Ca2+, H+, and HPO42− in the incubation medium altered the rates of synthesis of 1,25-dihydroxyvitamin D-3 (1,25(OH)2D-3) by isolated renal mitochondria obtained from D-deficient chicks. The present studies demonstrate that raising the medium concentration of K+ from 1 to 50 mM leads to a 6-fold increase in rate of 1,25(OH)2D-3 synthesis by isolated chick mitochondria; that the magnitude of this K+-dependent stimulation is enhanced by optimal concentrations of calcium (pCa = 5) and phosphate (pPi = 3) (3 mM) but not by pH (from 6.8 to 7.4); that the effect is not produced by similar changes in media Na+ concentration; and that the stimulatory effect of K+ is not blocked by ruthenium red, an inhibitor of calcium transport and of the calcium-dependent stimulation of mitochondrial 1,25(OH)2D-3 synthesis. It was also found taht valinomycin, a K+-specific ionophore, enhanced the sensitivity of the mitochondrial 1α-hydroxylase activity to K+. In the presence of valinomycin, an increase of pK+ to 3 was sufficient to cause a significant stimulation of 1,25(OH)2D-3 synthesis. It was concluded that changes in the ion content of the mitochondrial matrix space regulate the activity of the 1α-hydroxylase.  相似文献   

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The 190 kDa protein gene of R. rickettsii (R strain) contains region of tandemly arranged repeats. Homologous sequences were discovered within the genomes of all but one species of spotted fever group Rickettsiae. Southern blots showed restriction fragment lenght polymorphisms between species of Rickettsiae indicating structural differences among repeat regions. Further analysis using polymorase chain reaction techniques indicated the repeat regions vary in size among Rickettsiae. In addition, strains of R. rickettsii that vary in virulence were found to contain polymorphisms in this region.  相似文献   

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Complexation in the H+-Si(OH)4-tropolone (HL) system was studied in 0.6 M (Na)Cl medium at 25° C. Speciation and formation constants were determined from potentiometric (glass electrode) and 29Si-NMR data. Experimental data cover the ranges 1.5 ? - log[H+] ? 8.4, 0.002 ? B ? 0.012 M, and 0 ? C ? 0.060 M (B and C stand for the total concentration of Si and tropolone, respectively). In acid solutions (-log[H+] ? 3) a hexacoordinated cationic complex, SiL3+, is formed with log K(Si(OH)4 + 3HL + H+ XXX SiL3+ + 4H2O) = 7.08 ± 0.03. Furthermore, the formation of a disilicic acid was established from 29Si-NMR data. The dimerization constant of Si(OH)4 was found to be 10 exp (1.2 ± 0.1). In model calculations the solubility of quartz and amorphous SiO2 in the presence of tropolone is demonstrated. Data were analyzed using the least-squares computer program LETAGROPVRID.  相似文献   

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<正>Cytokinesis is the final stage of cell division that generates two daughter cells(Fededa and Gerlich,2012).The textbook version di-vides the plant and animal cell cytokinesis into two categories.Plant cells form a mid-zone phragmoplast via vesicle delivering and fusion,and cell wall materials are thus deposited.Animal cells form actomyosin contractile rings,which are the sole force that drives abscission.However,recent evidence has been mounting and pinpointing a pivotal role of membrane transport and subse-  相似文献   

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OBJECTIVE: To investigate the serum microRNAs as biomarkers in predicting chemoradiotherapy resistance in advanced-stage cervical squamous cell carcinoma (ACSCC) patients. METHODS: Serum samples were collected from International Federation of Gynecology and Obstetrics (FIGO) stage IIB to IIIB cervical squamous cell carcinoma patients treated with platinum based Concomitant Chemoradiotherapy (CCRT) in our hospital during September 2013 to November 2015. Twenty well-matched samples (10 resistant and 10 sensitive) were chosen to screen the miRNA expression profile using serum samples pooled with microarrays. miRNAs expressed significantly different between two groups were further verified in 131 patients (29 resistant and 102 sensitive) serum samples with TaqMan Real-time PCR. The AUC was used to evaluate the accuracy of the biomarkers for prediction. RESULTS: MiR-136-5, miR-152-3p and miR-206 were expressed significantly different between sensitive and resistant groups. Results of 131 patients verification showed that the levels of miR-206 in sensitive samples and resistant samples were 2.715 ± 0.2115 and 14.64 ± 1.184, respectively, which was significantly different (P < .0001), while miR-136-5p and miR-152-3p could not be tested without pre-amplification reactions. Univariate analysis revealed that miR-206 expression was significantly associated with patients' DFS. Multivariate analysis demonstrated that miR-206 expression, tumor differentiation and pelvic lymph nodes metastasis were the independent prognostic factors associated with DFS in this cohort (P = .008, 0.000, 0.000, respectively). The probability of the prognostic accuracy of miR-206 expression in predicting chemoradiotherapy sensitivity of ACSCC patients was 91.3% (79.3% sensitivity and 92.2% specificity). CONCLUSION: Serum miR-206 is a powerful tool in predicting chemoradiotherapy sensitivity in ACSCC patients.  相似文献   

17.
During the programmed cell death of intersegmental muscles in Manduca sexta, the activities of several enzymes begin to decrease at different times. The rate of loss of these activities also varies among organelles and is dependent on other factors. Myofilament proteins begin to disappear as early as 4 days before the emergence of the adult. An enzyme digesting ATP at acid pH increases 3-fold in total activity, and more than 10-fold in relative activity over the same period.  相似文献   

18.
Two recently published reports have described findings which will have a profound impact on the understanding of molecular mechanisms of human resistance to malaria infection. In Melanesian ovalocytosis, a genetic polymorphism found in Papua New Guinea and parts of South East Asia, the red cells are highly resistant to invasion by various species of malaria parasite. The molecular nature of the defect in ovalocytic erythrocytes was not known. Recent reports by Liu et al., (Liu, S.-C., Zhai, S., Palek, J., Golan, D., Amato, D., Hassan, K., Nurse, G., Babona, D., Coetzer, T., Jarolim, P. Zaik, M. and Borwein, S. (1990) N. Engl. J. Med. 323, 1530–1538.) and Jones et al. (Jones, G.L., Edmundson, H.M., Wesche, D. and Saul, A. (1991) Biochim. Biophys. Acta 1096, 33–40.) have now identified the abnormality in the band 3 protein of ovalocytic red cell membranes. A major discovery in the Jones et al, study is the presence of an extended peptide at the N-terminus of ovalocyte band 3 protein. This novel 13 amino acid extended sequence is not found in the primary structure of normal band 3 protein and was suggested to be the cause of band 3 defect in ovalocytes. We have analyzed this extended sequence through Genbank using SWISS-PROT database and found that an almost identical sequence exists in a malaria parasite protein called RESA.  相似文献   

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Lymphocytosis has been produced in mice and rats using heparin and other sulphated polysaccharides. Two hours after heparin (50 mg/kg ip) the concentration of lymphocytes in mouse blood increased threefold; it fell to control levels after 9 hr. The height of the lymphocytosis was related to the dose of heparin injected. After intravenous heparin in rats there was a comparable lymphocytosis maximal 1 hr after injection. In mice other negatively charged sulphated polysaccharides also caused lymphocytoses, which were greater and occurred later with increase in molecular weight of the substance injected. Results in rats were similar. No lymphocytosis followed the injection of negatively charged phosphated dextrans, positively charged DEAE dextran, or neutral dextran. There was no correlation between the effect of these substances on lymphocytes and their effect on coagulation of blood, hepatic phagocytosis, or the immune response to sheep red blood cells.  相似文献   

20.
The interaction of copper salts with NADH or NADPH in the presence of hydrogen peroxide at physiological pH is shown to produce hydroxyl radicals. The physiological significance of these results is discussed.  相似文献   

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