Summary [3H]prazosin bound to the membrane fraction derived from the ferret ventricular muscle with high affinity in a saturable manner (Kd = 0.25 nmol/l and Bmax = 27 fmol/mg protein in the right ventricle). [3H]CGP-12177, a -adrenoceptor ligand, bound to the membrane fraction with a Kd value of 0.29 nmol/l and a Bmax of 42 fmol/mg protein. In the isolated ferret papillary muscle driven at 1 Hz at 37°C, phenylephrine elicited a concentration-dependent positive intropic effect. The maximal effect of phenylephrine was comparable to that of isoprenaline. Prazosin (0.3 ol/l) shifted the concentration-response curve for phenylephrine slightly but significantly to the right, the maximal response being unaffected. In contrast, bupranolol (0.3 gmol/l) shifted the curve for phenylephrine markedly downwards: the maximal response was depressed significantly to 40% and the curve became less steep. In the presence of prazosin and bupranolol the curve was shifted to the right, being essentially parallel to the control curve. These results indicate that in the ferret ventricular myocardium both - and -adrenoceptors mediate the positive inotropic effect of phenylephrine. The extent of contribution of the two classes of adrenoceptor is quite different from that in other mammalian species. In the ferret heart, -adrenoceptors predominate over -adrenoceptors in mediating the positive inotropic effect of phenylephrine, although the number of -adrenoceptors is not especially high when compared with other species.
Send offprint requests to M. Endoh at the above address 相似文献
Objectives: To assess the efficacy and tolerability of a new matrix patch delivering 0.05 mg estradiol per day (Estraderm MX 50) in postmenopausal women with moderate to severe postmenopausal symptoms. Methods: A multicenter, double-blin, randomized, between-patient, placebo controlled trial in 109 postmenopausal women was carried out. Patches were applied twice weekly for 12 weeks. Patients were assessed at 4, 8 and 12 weeks of treatment. The primary efficacy variable was change from baseline in mean number of moderate to severe hot flushes (including night sweats) per 24 h during the last 2 weeks of treatment. Other variables included Kupperman Index, local and systemic tolerability. Plasma concentrations of estradiol (E2), estrone (E1) and estrone sulfate (E1S) were determined before and after treatment. Results: Estraderm MX was significantly superior to placebo (P < 0.001) in reducing mean number of moderate to severe hot flushes (including night sweats) per 24 h after 4, 8 and 12 weeks of treatment. The estimate of treatment group differences after 12 weeks was 4.2 hot flushes (95% confidence interval: 2.6–5.5). Estraderm MX also significantly reduced Kupperman Index at all time points compared to placebo (P < 0.001). Estraderm MX induced increases in mean E2, E1 and E1S plasma levels as expected (E2: baseline 2.7 pg/ml, 12 weeks 38.9 pg/ml; E1: baseline 18.8 pg/ml, 12 weeks 41.6 pg/ml; E1S: baseline 235.6 pg/ml, 12 weeks 765.1 pg/ml). Overall rates of adverse experiences were similar for Estraderm MX and placebo. The number of patients reporting skin irritation was low and similar in both groups. Conclusions: Estraderm MX 50, a new matrix patch, offers an effective and well tolerated dosage form for transdermal delivery of 0.05 mg E2 per day. 相似文献
Ten years ago, we proposed a model for thymus function in which thymic epithelial cells are primarily responsible for imprinting
major histocompatibility complex (MHC)-restricted specificity, and bone marrow-derived macrophages or dendritic cells are
responsible for the induction of self-tolerance. Since then, transgenic and knockout models have allowed for a dissection
of thymic stromal components in vivo, leading to a new understanding of their specialized functions. We have determined that
with regard to class II-restricted CD4 T-cell development, two distinct subsets of thymic epithelium help shape the repertoire:
Cortical epithelium appears solely responsible for positive selection, whereas a fucose-bearing subset of medullary epithelium
is specialized for negative selection. This absolute separation of positive and negative selection into two distinct spatial
and temporal compartments leads to a much simpler view of the process of repertoire selection. Finally, a novel view of the
function of the thymic medulla is discussed. 相似文献
In much of the literature to date, the definition of climacteric symptoms has been based largely upon women who present for medical treatment of symptoms. It is already well recognised that patients (of all ages and both sexes) presenting for medical treatment tend to report themselves as suffering from more life stresses and from more neurotic symptoms than people in the general population. Life stress and adequacy of coping may thus be important factors in the incidence of symptomatology at the climacteric, as at any other time of life. This study therefore investigated the proposal that post-menopausal women who present for treatment at menopause clinics suffer from more life stresses and more neurotic symptoms than post-menopausal women in the general pupolation.
It was found that patients did indeed suffer from more psychosocial stress, measured in terms of life events, clinical depression and anxiety scales and a rating scale based on a clinician's judgements of ongoing psychosocial stress, vulnerability and adequacy of coping. Patients also suffered from significantly more symptoms than non-patients, not only psychological, but also hypothalamic and metabolic symptoms. However, the incidence of hot flushes and vaginal atrophy was the same in both groups. The stress/coping rating was the measure which correlated most highly with the psychological symptoms reported by subjects as symptoms of menopause. Life events and clinical stress measures were more consistently related in the non-patient group, indicating possible intervening variables (such as hormone imbalance) in this relationship in the patient group. 相似文献
To evaluate directly the developmental potential of cortical CD4+8+ thymocytes, highly purified populations of small, nondividing CD4+8+TCRlow and large, dividing CD4+8+TCRhigh thymocytes from H-2d mice expressing a transgenic T cell receptor restricted by H-2Db (major histocompatibility complex class I) molecules were transferred into the thymus of normal, nonirradiated H-2b recipient mice. The results show that both populations generate CD4?8+ thymocytes under these conditions, thus providing conclusive evidence that small cortical thymocytes do not represent a “dead end” but an important intermediate stage in T cell development. 相似文献
Experiencing adverse life events during childhood may increase vulnerability to physical illnesses and psychological disorders during adulthood. We developed an Early Life Events Questionnaire (ELEQ) with 12 scales and administered it to 92 relatively healthy elderly individuals (29 men and 63 women). A canonical-correlation analysis of the 12 ELEQ scales and physical and psychological symptoms revealed a significant canonical correlation. The results indicate that those who grew up in a family with a harsh climate and whose affiliation needs were not met tended to have more psychological and physical symptoms in old age. Regression analysis revealed that, in men, early life events accounted for 42% of the variance in physical symptoms and 39% in psychological symptoms. No significant relationship, however, was found between ELEQ scales and health outcomes in women. These results suggest that women may be less vulnerable than men to the adverse health consequences of childhood deprivation and other misfortunes.This work was supported by Award SA 325 from the Medical Research Service of the Department of Veterans Affairs. 相似文献
Summary The time course of the reversal of toxic and nontoxic effects of digoxin by digoxin-specific antibody fragments (Fab) was measured in isolated human ventricular myocardium. A concentration of 2×10–6 mol/l digoxin was used to produce positive inotropy followed by mechanical signs of toxicity. After addition of a 1.5-fold higher molar concentration of digoxin-specific Fab, signs of toxicity disappeared within 30 min and digoxin-induced force of contraction decayed with a monoexponential time course with a half-life of 52 min. This rate of decay was almost identical to that observed for the dissociation of the digoxin-(Na++K+)-ATPase complex in human heart cell membranes. It is concluded that (a) digoxin-specific Fab are capable of completely removing digoxin from its binding sites, (b) the maximal rate of removal of digitalis glycosides from the (Na++K+)-ATPase is limited by the dissociation rate constant, and (c) there is a close correlation between the degree of binding of digitalis glycosides to the (Na++K+)-ATPase and the increase in force of contraction.Abbreviation Fab
Fragment antibody binding (digitalis antidote) 相似文献