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81.
Growth hormone-releasing hormone messenger ribonucleic acid in the hypothalamus of the adult male rat is increased by testosterone 总被引:3,自引:0,他引:3
Since intact adult male rats have higher GH pulse amplitude than do castrated animals and since GH-releasing hormone (GHRH) secretion is predominantly responsible for the production of these GH pulses, we hypothesized that testosterone stimulates GHRH synthesis in neurons of the hypothalamus. To test this hypothesis, we compared GHRH mRNA content in individual neurons of the arcuate (ARC) and ventromedial (VMH) nuclei among groups of intact (n = 3), castrated (n = 5), and castrated testosterone-replaced (n = 5) adult male rats. Cellular GHRH mRNA content was measured by using semiquantitative in situ hybridization with an 35S-labeled cRNA probe complementary to the coding sequence of rat GHRH mRNA. Castration resulted in an approximately 35% decline in GHRH mRNA signal relative to that in intact animals in both the ARC (P less than 0.005) and VMH (P less than 0.005). Replacement with testosterone at the time of castration completely prevented the decline in both areas. Testosterone can exert effects either through activation of the androgen receptor directly or through aromatization to estradiol; therefore, we also examined the effects on GHRH mRNA of replacement with 17 beta-estradiol (n = 5) or dihydrotestosterone (DHT), a nonaromatizable androgen (n = 4). Estradiol had no effect on the castration-induced decline in GHRH mRNA in either the ARC or VMH. In contrast, DHT partially prevented the postcastration decline in GHRH in the ARC (P less than 0.005), while having no statistically significant effect on GHRH mRNA in the VMH. These results clearly indicate that testosterone stimulates expression of GHRH mRNA in neurons of the hypothalamus. Furthermore, the failure of estradiol to substitute for testosterone and the ability of DHT to substantially support GHRH mRNA suggest that testosterone exerts its effects on GHRH gene expression predominantly through direct activation of the androgen receptor. 相似文献
82.
BACKGROUND: In counseling patients with a history of stroke, clinicians have limited information regarding the risks and benefits of alcohol consumption. OBJECTIVE: To examine the relationship between alcohol intake and risks of total and cardiovascular mortality in men with a history of stroke. METHODS: The study population consisted of 112 528 men from the enrollment cohort of the Physicians' Health Study, 1320 of whom reported a baseline history of stroke. Men provided self-reported data on alcohol consumption, which was classified into 1 of 4 categories: rarely or never drink, very light (<1 drink per week), light (1-6 drinks per week), or moderate (> or =1 drink per day). Cox proportional hazards models were used to assess the relative risks of mortality associated with alcohol consumption, after adjustment for major coronary risk factors. RESULTS: During a mean follow-up of 4(1/2) years, 369 men died, 267 of whom died of cardiovascular disease. Compared with men with a history of stroke who drank rarely or never, those with a very light to moderate alcohol intake had multivariate relative risks for total mortality of 0.88 (95% confidence interval [CI], 0.60-1.28), 0.64 (95% CI, 0.48-0.85), and 0.71 (95% CI, 0.54-0.94), respectively (P =.03 for trend); and relative risks for cardiovascular mortality of 0.89 (95% CI, 0.58-1.36), 0.56 (95% CI, 0.40-0.79), and 0.64 (95% CI, 0.46-0.88) P =.008 for trend). Compared with age-adjusted models, adjustment for major coronary risk factors did not significantly change risk estimates for total or cardiovascular mortality. CONCLUSIONS: These data indicate a possible inverse association between light to moderate alcohol intake and risks of total and cardiovascular mortality in men with a history of stroke. More data are needed to confirm or refute these results. 相似文献
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84.
Advanced Practice Nurses (APNs) can contribute to health prevention efforts with older adults by utilizing a health risk appraisal (HRA) during the Medicare Annual Wellness Visit. This study examined APN perceptions and practices concerning use of HRAs during Annual Wellness Visits (N = 51). Results indicate that respondents agree it is important to collaboratively identify risks and develop a personalized prevention plan, but only a small percentage (7.8%) use HRA data to do so. Reported concerns include reimbursement and time; further work on how to best integrate HRAs into APN practice to enhance prevention efforts with older adults is critical. 相似文献
85.
Stephanie M. Ramage Linda J. McCargar Casey Berglund Vicki Harber Rhonda C. Bell the APrON Study Team 《Nutrients》2015,7(8):6155-6166
Purpose: Pre-pregnancy is an under-examined and potentially important time to optimize dietary intake to support fetal growth and development as well as maternal health. The purpose of the study was to determine the extent to which dietary intake reported by non-pregnant women is similar to pre-pregnancy dietary intake reported by pregnant women using the same assessment tool. Methods: The self-administered, semi-quantitative food frequency questionnaire (FFQ) was adapted from the Canadian version of the Diet History Questionnaire, originally developed by the National Cancer Institute in the United States. Pregnant women (n = 98) completed the FFQ which assessed dietary intake for the year prior to pregnancy. Non-pregnant women (n = 103) completed the same FFQ which assessed dietary intake for the previous year. Energy, macronutrients, and key micronutrients: long-chain omega-3 fatty acids, folate, vitamin B6, vitamin B12, calcium, vitamin D and iron were examined. Results: Dietary intake between groups; reported with the FFQ; was similar except for saturated fat; trans fat; calcium; and alcohol. Pregnant women reported significantly higher intakes of saturated fat; trans fat; and calcium and lower intake of alcohol in the year prior to pregnancy compared to non-pregnant women who reported intake in the previous year. Conclusions: Despite limitations; a FFQ may be used to assist with retrospective assessment of pre-pregnancy dietary intake. 相似文献
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88.
Zweig RA Siegel L Hahn S Kuslansky G Byrne K Fyffe D Passman V Stewart D Hinrichsen GA 《Gerontology & geriatrics education》2005,25(4):109-129
Most older adults diagnosed with a mental disorder receive treatment in primary care settings that lack personnel skilled in geropsychological diagnosis and treatment. The Ferkauf Older Adult Program of Yeshiva University endeavors to bridge this gap by providing training in geriatric psychology, through coursework and diverse clinical practica, to clinical psychology doctoral students within a large urban professional psychology program. In an innovative effort to provide the most disadvantaged elderly with comprehensive mental health treatment and maximize trainee exposure to an interdisciplinary treatment model, the program also pairs selected doctoral psychology trainees with medical residents to optimize integrated mental health service delivery for primary care elderly. The program has the following core objectives: (1) Infuse the mental health and aging knowledge base into the regular graduate curriculum; (2) Provide interdisciplinary training in geropsychological diagnostic and consultative services within an urban primary care setting; (3) Provide interdisciplinary training in the practice of psychological and neuropsychological evaluation of elderly; (4) Provide training in geropsychological psychotherapeutic intervention, including individual, couples/family, and brief/psycho-educational therapies with outpatient older adults. These objectives are achieved by pooling the resources of a graduate school of psychology, a local public hospital, and an academic medical center to achieve educational and clinical service goals. 相似文献
89.
Historically, patients with prior aortic valve replacements who subsequently present with an ascending aortic aneurysm require placement of a valve conduit. However, if the patient has a functional mechanical valve with proven long-term durability, an attempt can be made to preserve the intact valve and to graft the aneurysmal aortic root. The case is described of a patient with a previously placed Starr-Edwards aortic valve who subsequently developed a 6-cm ascending aortic aneurysm. By removing the valve ball and using the existing sewing ring, a proximal graft anastomosis was created with ease, eliminating valve excision. 相似文献
90.
A fraction of enzymatically monodispersed rat thyrocytes from untreated animals clonally proliferate into thyroid follicular units following transplantation into the subcutaneous fat pads of syngeneic recipients. During the induction of experimental goiters in rats either with 3-amino-1,2,4-triazole/iodine sufficient diet or KClO4/Remington low iodine diet, the clonogenic fractions of cells from aminotriazole goiters decreased to 1.9 x 10(-4) and KClO4 goiters to 9.8 x 10(-5) as compared to 5.8 x 10(-3) for cells from age-matched controls during the growth phase of goitrogenesis. With continued aminotriazole treatment after thyroid hyperplasia had ceased, the clonogenic fraction increased to 2.0 x 10(-3) while continued KClO4 treatment had little further effect. The changes in the clonogenic fraction induced by both regimens were reversed during involution; goitrogenic rechallenge of involuted glands led to changes in the clonogenic fraction similar to that noted during the initial challenge. The clonogenic fractions of cells from aminotriazole goiters were greater than that of cells from KClO4 goiters at all time points examined despite similar TSH levels in situ. We conclude that the rat thyroid contains a hierarchy of cells with different proliferative capacities and that the clonogenic thyrocytes possess many of the attributes of a stem-cell. 相似文献