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41.
Phosphorylation of the androgen receptor by a nuclear cAMP-independent protein kinase 总被引:2,自引:0,他引:2
S A Goueli J L Holtzman K Ahmed 《Biochemical and biophysical research communications》1984,123(2):778-784
The androgen receptor was purified from rat ventral prostate. The purified receptor migrated as a single band of mol. wt. 87000 on SDS-polyacrylamide gels, had a kd for R-1881 (17 beta-hydroxy-17 alpha-methyl-estra-4,9,11-trien-3-one) binding as 6 nM, and sedimentation coefficient of 4.5 S. Phosphorylation of the purified receptor was studied by incubating it with [gamma-32P]ATP in the presence of several purified protein kinases including cAMP-dependent protein kinase, and four cAMP-independent protein kinases (which were active towards substrates such as phosvitin and casein). Phosphorylation of the 87000 mol. wt. androgen receptor protein occurred only in the presence of a nuclear cAMP-independent protein kinase (of the N2 type). No auto-phosphorylation of the receptor was detected. The results indicate that the androgen receptor is a phosphoprotein. Further, phosphorylation of the androgen receptor by only a specific nuclear cAMP-independent protein kinase may be important in determining the dynamics of its function. 相似文献
42.
43.
Microwaves induce an increase in the frequency of complement receptor-bearing lymphoid spleen cells in mice. 总被引:2,自引:0,他引:2
W Wiktor-Jedrzejczak A Ahmed K W Sell P Czerski W M Leach 《Journal of immunology (Baltimore, Md. : 1950)》1977,118(4):1499-1502
A single 30-min exposure of mice to 2450 MHz microwaves (12 to 15 mW/g body weight) in an environmentally controlled waveguide facility induced a significant increase in the proportion of complement-receptor positive lymphoid cells in the spleen. This effect was further enhanced by repeated (three times) exposures, which in addition produced a significant increase in the proportion of Ig+ cells. The proportion of theta-positive cells and the total number of spleen cells remained unchanged. 相似文献
44.
Ferdinand Bohlmann Maniruddin Ahmed Harold Robinson Robert M. King 《Phytochemistry》1982,21(7):1675-1678
The investigation of the aerial parts of a variety of Enhydra fluctuans afforded in addition to 4-hydroxyfarnesyl acetate and fluctuadin five new melampolides elucidated by high field 1H NMR spectroscopy. The chemotaxonomic situation is discussed briefly. 相似文献
45.
Ferdinand Bohlmann Maniruddin Ahmed Jasmin Jakupovic Robert M. King Harold Robinson 《Phytochemistry》1982,21(3):691-694
An investigation of Brickellia diffusa afforded three new dehydronerolidol derivatives and five new labdane derivatives, all highly oxygenated. The structures were elucidated by spectroscopic methods and a few chemical transformations. The compounds isolated showed close relationships to those isolated from Brickellia sp. 相似文献
46.
T cell responses to select Ia determinants using the I-A mutant mouse strain B6.C-H-2bm12 总被引:1,自引:0,他引:1
R R Skelly F Pappas S Koprak A Ahmed T H Hansen 《Journal of immunology (Baltimore, Md. : 1950)》1982,129(5):2094-2097
The T cell repertoire of B6.C-H-2bm12 mice (an I-A mutant mouse strain) to wild-type Iab antigens was investigated using both secondary proliferative cultures and cloned T cell lines. Because bm12 mice have a gain-loss mutation of their gene encoding the Ia beta-chain polypeptide, bm12 anti-B6 T cell responses are specific for the select component of Iab specificities that was lost as a result of the mutation. Although stimulator cells bearing Iab antigens elicited the strongest responses, Iaq, d, and s antigens also resulted in reproducible stimulations of these bm12 anti-B6-primed T cells. Cloned T cell lines isolated from bm12 anti-b6 cultures revealed similar findings, with most clones recognizing determinants unique for Iab antigens; however, clones showing cross-reactions with Iad and/or q were also selected. Using F1 hybrid responder T cells (mutant x cross-reactive strain), we further dissected this cross-reactivity into several distinct cross-reactive determinants. Because bm12 mice lack the serologically defined Ia differentiation antigen W39, T cell recognition of this determinant was investigated by using bm12 anti-B6-primed cells. Stimulation by Ia.W39+ cells was appreciably better than by Ia.W39- (Xid-defective) cells, suggesting that bm12 T cells recognize an Xid-regulated, W39-like Ia differentiation antigen. 相似文献
47.
Effect of microwaves (2450-MHz) on the immune system in mice: studies of nucleic acid and protein synthesis 总被引:1,自引:0,他引:1
CBA/J adult male mice were given single or triple exposures to 2450-mHz microwaves in an environmentally controlled wave guide facility. The average absorbed dose rate for a single exposure varied from 12 to 15 mW/g. Sham-exposed mice served as controls. Lymphoid cells were collected and tested for metabolic activity on days 3, 6, and 9 following a single exposure, and on days 9, 12, and 16 following triple exposures on days 0, 3, and 6. Cells were cultured in vitro for four hours to seven days before their metabolic rates were assayed. Under these conditions, microwaves failed to produce any detectable change in deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and protein synthesis, as measured by the incorporation of methyl(3H)-thymidine (3H-TDR) (DNA substrate), 3H-uridine (3H-UR) (RNA substrate), and 3H-leucine (protein substrate) by spleen, bone marrow, and peripheral blood lymphocytes (PBL) in vitro. These data suggest that microwave-induced increases in the frequency of complement-receptor (CR)- or surface-immunoglobulin (sIg)-bearing cells were not associated with a concomitant increase in cell proliferation and/or protein synthesis, and favor the concept that microwaves under these conditions stimulate already existing B-cell precursors for maturation. 相似文献
48.
Using water culture technique, some experiments have been performed to investigate the effect of 60 days salinization treatments
(0.0–100 meq 1−1 NaCl) on dry weight and on the content of some nutrient elements (Na, K, Ca, Mg, P, N) in castor bean, sunflower and flax
plants. In general the content of sodium increased progressively with the rise of salinity level. The relatively low and moderate
salinization levels (20 and 40 meq I−1 NaCl) resulted in a promotion rather than inhibition of the dry weight and in the content of most of the investigated elements
in the different organs of the test plants. However with the rise of salinization level from 60 to 100 meq l−1, the dry weight and the content of these nutrient elements were mostly reduced. 相似文献
49.
Stoichiometry and apparent dissociation constant of the calcium-arsenazo III reaction under physiological conditions. 总被引:1,自引:0,他引:1 下载免费PDF全文
In vitro and in situ tests have been run to characterize the reaction of the mettalochromic indicator, arsenazo III, with calcium. Job plots as well as plots of indicator absorbance vs. [Ca2+] at different indicator concentrations show a 1:1 reaction stoichiometry. Equilibrium analysis and analysis using Adair's equation are also consistent with 1:1 complexes being formed and give estimates of 34 and 45 muM for the apparent dissociation constant. In situ tests were carried out using giant neurons from Archidoris monteryensis, a marine gastropod mollusc. Dye absorbance changes were measured during voltage clamp pulses which produced a fixed calcium influx. The dependence of absorbance change on total dye concentration is consistent with the formation of a 1:1 complex of Ca with ArIII if measurements are made during the initial period of the loading pulse, less than 300 ms, although the apparent dependency changes with longer delay in measurements from the onset of the pulse. 相似文献
50.
T Ahmed A Januszkiewicz P Eyre M J Robinson M A Sackner 《Journal of applied physiology (Bethesda, Md. : 1985)》1981,51(5):1204-1213
We investigated the acute pulmonary hemodynamic effects of intravenous copper sulfate (CuSO4) infusion and its mechanism of action in six groups of conscious sheep (total 40). After 300 mg CuSO4 alone, mean pulmonary artery pressure (Ppa) increased from 10.3 to 22.5 Torr and pulmonary artery wedge pressure (Ppaw) from 3.5 to 7.6 Torr, whereas systemic arterial pressure (Psa) increased from 95 to 102 Torr. Cardiac output (Qp) decreased from 4.7 to 3.3 l/min. Pulmonary vascular resistance (PVR) and systemic vascular resistance (SVR) increased to 320 and 160% of base line, respectively. The hemodynamic changes correlated well with serum copper, which increased from a base-line value of 0.12 to 3.5 mg/dl after the CuSO4. Serum dopamine beta-hydroxylase increased from 3.2 U/l before CuSO4 injection to 5.7 after its administration, signifying activation of adrenergic nervous system. H1-histamine receptor blockade with chlorpheniramine failed to prevent the effects of CuSO4. Pretreatment with methysergide, a serotonin antagonist, partially attenuated the effects of CuSO4. Phenoxybenzamine, an alpha-adrenergic receptor blocker, and 6-hydroxydopamine, a catecholamine depleting agent, completely blocked the effects of CuSO4. beta-Adrenergic receptor blockade with propranolol enhanced the effects of CuSO4. We conclude, that, in conscious sheep, acute infusion of CuSO4 caused a marked reversible increase in PVR with a slight transient increase in SVR, and this pulmonary hypertension was produced by stimulation of the alpha-adrenergic nervous system. 相似文献