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1.
The activities of the alpha-1 antagonist prazosin and alpha-2 antagonist yohimbine were evaluated against noradrenaline (NA), methoxamine (Me) and clonidine (Clo) on the reserpinized rat vas deferens. Prazosin antagonized competitively Me but not NA and Clo. On the other hand yohimbine showed a low and not competitive antagonism towards all the three agonists. Similar results were obtained when the antagonistic activities were tested in the presence of the alternative antagonist, in the attempt to isolate a single receptor population. We can conclude that the smooth musculature of the rat vas deferens contains prevalently alpha-1 adrenoceptors and a small population of NA activated receptors resistant to alpha-2 antagonists.  相似文献   
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Neurological Sciences - Although recent data show that SARS-CoV-2 infection seems to affect the central nervous system (CNS), little is known about the neuropsychiatric effects resulting from this...  相似文献   
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We have explored the systolic time intervals of 52 patients with angina pectoris at the time of their hospitalization in our wards. Our results are in close agreement with published data, essentially indicating prolongation of the preejection time and shortening of the ejection time. These alterations of systolic times can be interpreted pathophysiologically as as expressing reduced myocardial contractility. The long PEP-short LVET polygraph picture, occurring in the course of chronic ischemic heart disease, reveals the deficit of myocardial contractility at a stage of the disease at which clinical evidence of left ventricular failure is usually not yet detectable.  相似文献   
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The effects of silymarin on bronchoconstriction induced by antigen challenge and on post-antigen challenge hyperresponsiveness to substance P were evaluated in sensitized guinea-pigs. Silymarin significantly decreased the bronchoconstriction due to antigen administration in the early phase of the response. In contrast, the dose-response curve for substance P recorded 1 h after antigen challenge was not modified by pretreatment with silymarin. The influence of the flavonoid on hyperresponsiveness to histamine in propranolol- and PAF (platelet-activating factor)-treated animals was also assessed. Silymarin did not affect hyperresponsiveness to histamine induced by either propranolol or PAF although it had inhibitory activity on the bronchial contractile response to the autacoid. These results suggest that silymarin has a protective effect in the early phase of allergic asthma, an effect, which may be related to a negative influence of the flavonoid on bronchial responsiveness to histamine.  相似文献   
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背景:目前认为,心肌梗死(myocardial infarction,MI)和缺血性卒中与金属蛋白酶(metallopmteinases,MMPs)消化基质,导致动脉粥样斑块破裂有关。环氧合酶2(COX-2)和前列腺素E2合成可诱导巨噬细胞MMPs和MMP-9的产生。尽管COX-2的表达由遗传决定,但是COX-2多态性与MI和卒中发病危险的关系仍不清楚。  相似文献   
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We measured cell surface expression of CD34, HLA-DR, CD38, CD19, CD33, CD71, and CD45 antigens in the hematopoietic progenitor cells of fetal cord blood to investigate immunophenotypic changes at different gestational ages. These antigens were identified by flow cytometry in 11 fetuses (gestational age 19-24 wk, in 12 preterm (25-28 wk) and in ten newborn infants born at term. The frequency and number of CD34+ cells were higher in the blood of the 11 fetuses; in addition, a statistically significant inverse correlation between number of CD34+ cells and advancing gestational age was noted. The numbers of CD34+ CD19+, CD34+ CD33+, and CD34+ CD45+ coexpressing cells were significantly higher in the fetuses, whereas CD34+ CD38+ cells were more represented in the neonates at term. Gestational age was inversely correlated with the number of CD34+ CD19+ and CD34+ CD33+ coexpressing cells. A positive correlation between gestational age and CD34+ CD38+ cells was noted. The number of CD34- CD19+, CD34- CD38+, and CD34- CD45+ cells was higher in term infants; furthermore, a significant correlation between advancing gestational age and CD34- CD38+ or CD34- CD45+ cells was demonstrated. The proliferative capacity was also higher at lower gestational ages. These data suggest that the development and lineage commitment of fetal cord blood hematopoietic progenitor cells are very active during the last two trimesters of pregnancy. The most significant changes of hematopoietic cells maturation seem to occur within 25 wk of gestation.  相似文献   
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On the basis of results previously obtained from structural and theoretical studies on beta-adrenergic drugs, a series of aliphatic oxime ether derivatives (AOEDs) was synthesized. As expected, pharmacological in vitro tests showed that compounds examined exhibit a marked and competitive antagonism at beta-adrenoceptors; the beta 2/beta 1 selectivity ratio indicated that they are more active on the tracheal than on the cardiac beta-receptor. The chemical reactivity of the AOEDs was studied through the calculation of the electrostatic molecular potential (EMP) on a model compound in its preferred conformation. The results showed that the EMP trend agrees with that previously calculated for other beta-blocking drugs.  相似文献   
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OBJECTIVE: Mutations of the rhodopsin gene are responsible for autosomal dominant or recessive retinitis pigmentosa (RP). The present study reports the first prenatal diagnosis performed on chorionic villi biopsy of a pregnant woman affected by a severe form of autosomal dominant transmitted RP, due to the Arg135Trp substitution. METHODS: The rhodopsin gene was analysed by automated direct sequencing and, for the first time, by fluorescence-assisted mismatch analysis (FAMA). The latter is an inexpensive, rapid and particularly sensitive method, based on the chemical cleavage of the mismatch in heteroduplex DNA molecules marked with strand-specific fluorophores. RESULTS: FAMA is a feasible procedure for prenatal molecular diagnosis of rhodopsin mutations. The redundancy of signals obtained by FAMA and its sensitivity make it suitable for identifying exactly the position of the mutation and the nucleotide substitution. CONCLUSIONS: An association is proposed between FAMA and automated direct sequencing procedures, in order to achieve optimal results in terms of reliability for prenatal diagnosis of rhodopsin mutations.  相似文献   
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