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91.
OBJECTIVE: To assess HIV-AIDS-related knowledge, attitudes, and preventive behavior of pregnant Korean women before designing patient and public education programs. DESIGN: Pre-experimental cross-sectional survey. POPULATION, SAMPLE, SETTING, YEARS: Convenience sample of 409 women at six prenatal clinics in Seoul, Korea, in 1993. OUTCOME MEASURES: HIV-AIDS-related knowledge, attitudes, and preventive behavior. METHODS: Self-administered questionnaires. FINDINGS: The women described high levels of knowledge about HIV and AIDS risk factors but less knowledge about transmission of the virus, as well as attitudes of rejection toward unrelated people with HIV/AIDS; 16% provided condoms for their husband's use in extramarital sex, the primary risk behavior. CONCLUSIONS: Korean women are at risk for heterosexual transmission of HIV despite knowledge of risk factors. CLINICAL IMPLICATIONS: Korean education programs for women should focus on modes of heterosexual transmission, care of individuals with HIV or AIDS, self-assessment of HIV-AIDS risk, and self protection.  相似文献   
92.
Ozone is a drinking water disinfectant that quickly and efficiently kills many types of pathogens. However, the ozonation of bromide ion containing waters can form the disinfection byproduct, bromate ion. Bromate ion is a possible human carcinogen that is regulated by the US EPA at a Maximum Contaminant Level (MCL) of 10 micrograms per liter (μg/L). The lifetime risk at the MCL was calculated from studies where laboratory animals received large doses of bromate ion that would produce effects in their lifetimes. The data from these large doses was fitted to a low-dose linear extrapolation (also called a linearized dose-response) model. The model assumes there is a finite, albeit small, risk at any dose above zero of a genotoxic carcinogen. The validity of the linearized dose-response model projection at low doses is being questioned (i.e., the actual shape and slope of the dose/response as the dose approaches zero). The test system is bromate ion in synthetic and real gastric juices. The results reported here show that the bromate ion half-life, in the presence of typical H+, Cl?, and H2S concentrations found in the stomach, is 1.5–2 minutes. Thus, as much as 99% of the ingested bromate ion should be decomposed, while it is retained in the stomach. The results of these experiments will be used in the development of a more scientifically rigorous methodology for determining low level effects of bromate ion.  相似文献   
93.
Solitary endobronchial papillomas in adults are rare neoplasms. Only sporadic cases have been documented. The histologic classification of these tumors remains problematic, and little is known about their clinical behavior. The clinical and pathologic features of 13 endobronchial papillomas and a single endobronchiolar papilloma were reviewed. In situ hybridization for human papillomavirus (HPV) types 6/11, 16/18, and 31/33/51 was performed on seven cases. Twenty-seven additional well-documented cases were identified in a literature review. Human papillomavirus studies were performed in four of the previously reported cases. The 41 neoplasms combined from the Armed Forces Institute of Pathology and literature review were divided into three groups according to their histologic features. Thirty-one of 41 (76%) patients were men. The ages of the patients ranged from 26 to 74 years (median, 57 years). Three morphologically distinct histologic types were recognized; 27 squamous cell papillomas, 7 glandular papillomas, and 7 mixed squamous and glandular papillomas. Squamous papillomas: 23 of 27 (85%) patients were men, and the median age was 54 years. Six of eleven (55%) of these patients smoked. Twenty-six lesions were exophytic and a single lesion had an inverted pattern. Seven of 24 (29%) lesions featured cytologic atypia and 5 of 24 (14%) had viral cytopathic effect. Five of seven (71%) cases examined for HPV DNA were positive. Three of 18 (17%) recurred. Glandular papillomas: Four of seven (57%) patients were women. The mean age was 67 years. One of five (20%) patients smoked. Five lesions were central, and two were peripheral. Four lesions had columnar epithelium, and three had ciliated epithelium. One of six (17%) lesions recurred. Mixed papillomas: five of seven (71%) patients were men. The median age was 64 years. Three of five (60%) patients smoked. Three of seven (43%) lesions featured cytologic atypia. Four of five lesions were examined for HPV DNA and all were negative. No lesions recurred. This study demonstrates that solitary endobronchial papillomas can be separated into three distinct morphologic categories. Squamous cell and mixed papillomas are predominantly lesions of male smokers in their 6th decade. Although cytologic atypia is observed in many cases, the rarity of these tumors and difficulty in separating papillomas from endobronchial papillary squamous carcinomas make generalizations regarding the risk of progression to carcinoma tenuous at best. Human papillomavirus appears to play a pathogenetic role in some squamous cell papillomas, but not in mixed papillomas, yet its presence in the squamous lesions does not correlate with recurrence or malignancy. The first report of an inverted squamous cell papilloma indicates clinical features similar to the more common exophytic squamous cell papillomas. Glandular papillomas, the rarest of all endobronchial papillomas, are found in an older age group than squamous and mixed papillomas, and most-patients are nonsmokers. Based on these findings, all endobronchial papillomas should be completely excised.  相似文献   
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96.
Aging is a complex physiological phenomenon and several different theories have been elaborated about its origin. Among such theories, the 'mitochondrial theory of aging', which has gained a large support, indicates the accumulation of somatic mutations of mitochondrial DNA leading to the decline of mitochondrial functionality as one of the driving forces for the process itself. In this review data on rat and man from our laboratory and from recent literature have been thoroughly examined and compared in order to provide the 'state-of-the-art' on the role of mitochondria in aging. Alterations of structure and expression of mitochondrial genome with aging, to find out the eventual relevant changes of mitochondrial biogenesis, have been studied in rat whereas the relationship between cytochrome c oxidase activity and 'common deletion' has been studied in man. Results on the effect of acetyl-L-carnitine on the mitochondrial functionality are also reported.  相似文献   
97.
This study examined the efficacy of glycerol and water hyperhydration (1 h before exercise) on tolerance and cardiovascular strain during uncompensable exercise-heat stress. The approach was to determine whether 1-h preexercise hyperhydration (29.1 ml H2O/kg lean body mass with or without 1.2 g/kg lean body mass of glycerol) provided a physiological advantage over euhydration. Eight heat-acclimated men completed three trials (control euhydration before exercise, and glycerol and water hyperhydrations) consisting of treadmill exercise-heat stress (ratio of evaporative heat loss required to maximal capacity of climate = 416). During exercise ( approximately 55% maximal O2 uptake), there was no difference between glycerol and water hyperhydration methods for increasing (P < 0.05) total body water. Glycerol hyperhydration endurance time (33. 8 +/- 3.0 min) was longer (P < 0.05) than for control (29.5 +/- 3.5 min), but was not different (P > 0.05) from that of water hyperhydration (31.3 +/- 3.1 min). Hyperhydration did not alter (P > 0.05) core temperature, whole body sweating rate, cardiac output, blood pressure, total peripheral resistance, or core temperature tolerance. Exhaustion from heat strain occurred at similar core and skin temperatures and heart rates in each trial. Symptoms at exhaustion included syncope and ataxia, fatigue, dyspnea, and muscle cramps (n = 11, 10, 2, and 1 cases, respectively). We conclude that 1-h preexercise glycerol hyperhydration provides no meaningful physiological advantage over water hyperhydration and that hyperhydration per se only provides the advantage (over euhydration) of delaying hypohydration during uncompensble exercise-heat stress.  相似文献   
98.
In this paper we examine the effects of socioeconomic development, the status of women, and family planning on fertility and the extent to which these effects vary among the nineteen districts of Bangladesh. The 1983 and 1991 Bangladesh Contraceptive Prevalence Survey data are used to examine the effects of these factors on differences in contraceptive use among currently married women aged 15-49. The proportion of currently married women aged 15-49 using contraception was 46.3 per cent in 1991, a considerable increase from 26.5 per cent in 1983. Contraceptive use rates for all the districts increased substantially over the period between 1983 and 1991 and the gap between Dhaka's rate and those of other districts was narrower in 1991 than in 1983. An analytical model composed of socioeconomic development, status of women, and family planning variables is tested using logistic regression. The logit model is used to evaluate the effects of a selected group of variables on the probability of using contraceptive methods. The analysis demonstrates clearly that socioeconomic development and women's status significantly impact the use of contraceptive methods in Bangladesh. The results also suggest that better-educated, employed women are more likely to use contraception than those who have little or no formal education and who are not employed. In 1983, rural-urban differences in contraceptive use were significant, but in 1991 area of residence was not significant, which suggests that family planning programs may have played an important role in providing contraceptive information and technology to rural areas. Our analysis also suggests that family planning programs operated more efficiently in some districts than in others, and regional differences remained important in 1991 as they were in 1983. Decomposition analysis suggests that shifts in population structure favored increased contraceptive use in Bangladesh. This analysis also indicates that change in rate is also important, contributing about 21 per cent of the overall increase in contraceptive use.  相似文献   
99.
Seasonal breeders, such as sheep and hamsters, by virtue of their annual cycles of reproduction, represent valuable models for the study of plasticity in the adult mammalian neuroendocrine brain. A major factor responsible for the occurrence of seasonal reproductive transitions is a striking change in the responsiveness of gonadotropin-releasing hormone (GnRH) neurons to the inhibitory effects of gonadal steroids. However, the neural circuitry mediating these seasonal changes is still relatively unexplored. In this article, we review recent findings that have begun to define that circuitry and its plasticity in a well-studied seasonal breeder, the ewe. Tract tracing studies and immunocytochemical analyses using Fos and FRAs as markers of activation point to a subset of neuroendocrine GnRH neurons in the MBH as potential mediators of pulsatile GnRH secretion. Because the vast majority of GnRH neurons lack estrogen receptors, seasonal changes in responsiveness to estradiol are most probably conveyed by afferents. Two possible mediators of this influence are dopaminergic cells in the A14/A15 cell groups of the hypothalamus, and estrogen receptor-containing cells in the arcuate nucleus that project to the median eminence. The importance of GnRH afferents in the regulation of season breeding is underscored by observations of seasonal changes in the density of synaptic inputs onto GnRH neurons. Thyroid hormones may participate in this remodeling, because they are important in seasonal reproduction, influence the morphology of other brain systems, and thyroid hormone receptors are expressed within GnRH neurons. Finally, in the hamster, neonatal hypothyroidism affects the number of caudally placed GnRH neurons in the adult brain, suggesting that thyroid hormones may influence development of the GnRH system as well as its reproductive functions in the adult brain.  相似文献   
100.
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