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OBJECTIVE: A summary about the final results of the Hungarian double-blind placebo controlled randomised trial of periconceptional folic acid containing multivitamin and trace element supplementation. RESULTS: The major finding is a significant prevention of the first occurrence of neural-tube defect, urinary tract and cardiovascular defects, in addition a decrease in the rate of limb deficiencies and congenital hypertrophic pyloric stenosis. Fertility was slightly improved and the rate of twins increased significantly after periconceptional multivitamin supplementation. The effect of multivitamin supplementation for fetal death is controversial, but in general there is no clinically significant change. Periconceptional multivitamin supplementation can reduce the occurrence of nausea and vomiting. PRACTICAL IMPLEMENTATIONS: Consumption of foods which are rich in folate may not be the best way to prevent neural-tube defects and other congenital abnormalities. Periconceptional multivitamin supplementation is part of the periconceptional care in Hungary and it is an appropriate forum for the practical delivery for this primary prevention action. However, as a large proportion of pregnancies are unplanned, the widespread use of bread fortified with folic acid, vitamin B12 and B6 may decrease a considerable part of neural-tube defects and some other congenital abnormalities, in addition to vascular diseases due to hyperhomocysteinemia.  相似文献   
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In 1991 a new reform for postgraduate trainees was introduced in Denmark. Since the reform all young doctors-as a compulsory part of their vocational training-have had to work for six months as general practice trainees, no matter their wishes for future specialization. The reform furthermore led to the general practice trainees being considerably younger than previously-the average length of postgraduate experience before working as a trainee declined from six to seven years to one to two years. In this light an investigation was conducted from August 1992 to July 1993. Seven hundred and fifty-eight questionnaires were sent to general practice trainees and their tutors in Denmark. Ninety-five percent of the questionnaires were returned, thus it was possible to evaluate the new compulsory training in general practice. In conclusion, the main part of the trainees had a positive assessment of the work conditions in general practice. However, a large part of the trainees indicated that their tutor doctors had set aside too short a time for supervision.  相似文献   
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The hypothalamo-pituitary-adrenal (HPA) axis is modulated by sex hormones. Few data exist on the relation between acute estrogen deficit and HPA axis response to corticotropin-releasing hormone (CRH). The effects of a sudden drop in estradiol levels on basal and CRH-stimulated levels of ACTH, cortisol, testosterone, androstenedione and 17-hydroxyprogesterone (17-OHP) were assessed in nine premenopausal women (44-48 years of age), before and after ovariectomy. The CRH test was performed before and 8 days after ovariectomy. A significant reduction in ACTH and adrenal steroids but not in cortisol response to CRH was observed after ovariectomy. The ratio of deltamax androstenedione/17-OHP after CRH stimulation was substantially the same before and after ovariectomy, whereas deltamax 17-OHP/cortisol was significantly lower in ovariectomized women showing increased 21- and 11beta-hydroxylase activity. The results show that the acute estrogen deficit induces changes in the HPA axis characterized by reduced stimulated secretion of ACTH and steroids but normal stimulated cortisol production.  相似文献   
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The spectroscopic, conformational, and functional properties of mutant carbonmonoxy hemoglobins in which either the beta-globin Val67(E11) or the alpha-globin Val62(E11) is replaced by threonine have been investigated. The thermal evolution of the Soret absorption band and the stretching frequency of the bound CO were used to probe the stereodynamic properties of the heme pocket. The functional properties were investigated by kinetic measurements. The spectroscopic and functional data were related to the conformational properties through molecular analysis. The effects of this nonpolar-to-polar isosteric mutation are: (i) increase of heme pocket anharmonic motions, (ii) stabilization of the A0 conformer in the IR spectrum, (iii) increased CO dissociation rates. The spectroscopic data indicate that for the carbonmonoxy derivatives, the Val --> Thr mutation has a larger conformational effect on the beta-subunits than on the alpha-subunits. This is at variance with the deoxy derivatives where the conformational modification was larger in the heme pocket of the alpha-subunit (Cupane, A., Leone, M., Militello, V., Friedman, R. K., Koley, A. P., Vasquez, G. P., Brinigar, W. S., Karavitis, M., and Fronticelli, C. (1997) J. Biol. Chem. 272, 26271-26278). These effects are attributed to a different electrostatic interaction between Ogamma of Thr(E11) and the bound CO molecule. Molecular analysis indicates a more favorable interaction of the bound CO with Thr Ogamma in the beta-subunit heme pocket.  相似文献   
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BACKGROUND: Reactive oxygen metabolites generated from endothelial xanthine oxidase (XO) trigger reperfusion injury in many organs. We evaluated the possibility that endothelial XO was localized on the endothelial cell surface, as well as within the cytoplasm. METHODS: Primary cultures of bovine (BAECs) and porcine (PAECs) aortic endothelial cells were grown in media documented to be free of XO. Polyclonal and monoclonal antibodies were developed against XO. These antibodies were used to evaluate BAEC and PAEC for cell surface XO through immunofluorescence staining, hybridoma cell surface labeling, and endothelial cell surface binding. RESULTS: These antibodies bound specifically to the surface of these cells when the membrane was shown to be intact and impermeable (and the cytoplasm inaccessible) to immunoglobulins Moreover, hybridoma cells expressing monoclonal antibody to XO bound specifically to the endothelial cell surface. Finally, intact endothelial cells bound specifically to the anti-XO polyclonal antibodies immobilized to the surface of a Petri dish. The integrity of these endothelial cell plasma membranes was demonstrated by the subsequent growth and replication of these cells in culture. CONCLUSIONS: These findings indicate that XO is present on the outside surface of the endothelial cell plasma membrane. This would not only explain the known in vivo efficacy of intravascularly administered large molecular weight antioxidants (such as superoxide dismutase) but could have important implications for inflammatory signaling.  相似文献   
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BACKGROUND: Familial hyperparathyroidism is a rare condition reported to behave more aggressively than sporadic hyperparathyroidism. METHODS: A retrospective (1975 to 1995) analysis was performed on 30 such patients. All patients had at least one first-degree relative with surgically treated hyperparathyroidism and no personal or family history of multiple endocrine neoplasia. RESULTS: There were 19 women and 11 men with a mean age of 39 years (range, 13 to 78 years). Fourteen patients (47%) had nephrolithiasis. The mean serum calcium level was 11.6 mg/dl (range, 10.5 to 15.3 mg/dl). Twenty-three primary and 15 repeat explorations (eight recurrent and seven persistent disease) were performed during the study period. Follow-up was obtained on all patients and ranged from 1 to 21 years (mean, 12 years). At the conclusion of the study, hypercalcemia (five recurrent and one persistent) was present in six patients (20%). CONCLUSIONS: Familial hyperparathyroidism is a distinct and unique entity. Patients are diagnosed at a young age and have a high incidence of nephrolithiasis. Long-term follow-up is mandatory because of the high incidence of both recurrent and persistent hyperparathyroidism. Surgical treatment should include subtotal parathyroidectomy and routine transcervical thymectomy performed in centers with experience in the management of multiple-gland parathyroid disease.  相似文献   
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