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101.
To probe age-related changes in skin barrier function, transepidermal water loss (TEWL) rates have been measured in young (19–42 years) and old (69–85 years) subjects. TEWL was determined at ventral forearm skin sites, which had been occluded for 24 hr with polypropylene chambers. Baseline TEWL rates (J
, which showed no dependence on age, were measured for each subject before and after the experiment. Following removal of the occlusive chamber, TEWL was monitored continuously from t = 0.5 min until its return to the baseline (preocclusion) level, which was typically in the range of 2–7 g/m2/hr. Initial TEWL rates (mean ± SD) were found to differ significantly between young (28.6 ± 7.5 g/m2/hr; n = 26) and old (36.9 ± 10.5 g/m2/hr; n = 18) subjects (P < 0.01). Relaxation of TEWL to J
was significantly slower in the aged cohort, such that the characteristic time for diffusion of water in the stratum corneum was estimated to be (mean ± SD) 176 ± 59 min for the young subjects, compared to 360 ± 76 min for the old (P < 0.001.). Thus, the initial TEWL value following removal of occlusion is significantly greater, and the excessive stratum corneum hydration produced by occlusion is dissipated more slowly, in old skin than in young. A hypothesis to explain the slower relaxation of perturbed TEWL in old skin is proposed. 相似文献
102.
Treloar SA Sadrzadeh S Do KA Martin NG Lambalk CB 《Human reproduction (Oxford, England)》2000,15(1):55-59
In a twin sample where duration of gestation can be controlled, a specific example of the fetal origins hypothesis concerning association between low birth weight and early age at menopause is explored. The hypothesis is based on the physiologically plausible path from intrauterine growth retardation and reduced numbers of primary follicles to an earlier menopause. The sample comprised 323 Australian female twin pairs where both co-twins had reached menopause naturally and reported on their weight at birth. Regression analysis showed no linear association between the two variables (P = 0.371, r(2) = 0.0009). Intra-pair differences in age at menopause were investigated in the context of relative birth weight of co-twins. In 265 pairs an intra-pair birth weight difference was reported. In monozygotic (MZ) pairs (n = 168) this allowed for control of genetic effects as well as gestation duration. No significant differences dependent on birth weight relative to co-twin were found for age at natural menopause in either MZ or dizygotic (DZ) twin pairs, even in pairs whose birth weights differed markedly. There was some indication that twins with premature ovarian failure were heavier at birth than twins with normal or later menopausal age. We conclude that the hypothesis that lower birth weight is associated with earlier menopause is not supported by our data. 相似文献
103.
104.
BACKGROUND: Two genome scans for susceptibility loci for type 1 diabetes using large collections of families have recently been reported. Apart from strong linkage in both studies of the HLA region on chromosome 6p, clear consistent evidence for linkage was not observed at any other loci. One possible explanation for this is a high degree of locus heterogeneity in type 1 diabetes, and we hypothesised that the sex of affected offspring, age of diagnosis, and parental origin of shared alleles may be the bases of heterogeneity at some loci. METHODS: Using data from a genome wide linkage study of 356 affected sib pairs with type 1 diabetes, we performed linkage analyses using parental origin of shared alleles in subgroups based on (1) sex of affected sibs and (2) age of diagnosis. RESULTS: Among the results obtained, we observed that evidence for linkage to IDDM4 on chromosome 11q13 occurred predominantly from opposite sex, rather than same sex sib pairs. At a locus on chromosome 4q, evidence for linkage was observed in sibs where one was diagnosed above the age of 10 years and the other diagnosed below 10 years of age. CONCLUSIONS: We show that heterogeneity tests based on age of diagnosis, sex of affected subject, and parental origin of shared alleles may be helpful in reducing locus heterogeneity in type 1 diabetes. If repeated in other samples, these findings may assist in the mapping of susceptibility loci for type 1 diabetes. Similar analyses can be recommended in other complex diseases. 相似文献
105.
106.
Age related macular degeneration (AMD) is the leading cause of visual impairment in the elderly and a major cause of blindness in the developed world. The disease can take two forms, geographic atrophy and choroidal neovascularisation. The pathogenesis of AMD is poorly understood. There are undoubtedly environmental and other risk factors involved and the adverse effect of smoking is well established. Several studies have shown that genetic factors are important but leave uncertainty about the magnitude and nature of the genetic component and whether it varies with the type of AMD. Several hereditary retinal dystrophies show similarities to AMD and these genes are potential candidate susceptibility genes. Particular interest has focused on the ABCR gene which is responsible for autosomal recessive Stargardt macular dystrophy. It has been claimed that heterozygotes for ABCR mutations are predisposed to AMD but the data are conflicting. Studies of the genes responsible for autosomal dominant Sorsby fundus dystrophy, Doyne honeycomb retinal dystrophy, and Best disease have given negative results. In one large AMD family, linkage has been reported to markers in 1q25-q31. Recent data suggest that the ApoE epsilon4 allele may be associated with reduced risk of AMD. A better understanding of the genetic factors in AMD would contribute to understanding the pathogenesis. If those at risk could be identified it may be possible to modify lifestyle or develop novel therapies in the presymptomatic stage to prevent disease or decrease its severity. 相似文献
107.
Density of γ/δ+ T cells in the jejunal epithelium of patients with coeliac disease and dermatitis herpetiformis is increased with age 下载免费PDF全文
E SAVILAHTI T
RML A ARATO G HACSEK K HOLM T KLEMOLA A NEMETH M MKI T REUNALA 《Clinical and experimental immunology》1997,109(3):464-467
Increased density of γ/δ T cell receptor (TCR)+ intraepithelial lymphocytes is the only characteristic in the jejunum of patients with coeliac disease and dermatitis herpetiformis which is not normalized on a gluten-free diet. We explored the age-dependent changes in intraepithelial γ/δ and α/β TCR+ cells from 137 biopsies from patients with coeliac disease and dermatitis herpetiformis and from controls. Biopsy specimens from 100 patients with coeliac disease and dermatitis herpetiformis and from 37 controls were studied with an immunohistochemical method using MoAbs to T cell receptors and peroxidase staining. An increase in the density of intraepithelial γ/δ T cells above the mean +2 s.d. of the density in controls was present in 97 of 100 specimens from patients with coeliac disease and dermatitis herpetiformis. The density of γ/δ+ cells of patients with coeliac disease and dermatitis herpetiformis on a normal gluten-containing diet showed a positive correlation with age (r = 0.45, P< 0.0001). In controls, the density of γ/δ+ cells remained low throughout the age-range studies, from age 0.6–57 years. In controls, α/β+ cells increased with age (r = 0.57, P< 0.001). The increase in density of intraepithelial lymphocytes with age is in agreement with their thymus-independent character and local proliferation. 相似文献
108.
109.
C. Grigoreas D. Pappas I. D. Galatas G. Kollias S. Papadimos P. Papadakis 《Allergy》1993,48(3):142-146
The distribution of IgE in a large randomly stratified Greek population sample was determined in 1187 subjects (793 men and 394 women) aged between 20 and 60 years. Skin prick testing was performed and serum total IgE expressed in iu/ml was measured by Phadebas PRIST: the data are presented as the geometric mean. Subjects were classified as atopic (257 men, 118 women) and nonatopic (536 men, 276 women) according to the results of skin testing with various aeroallergens. At any age, atopic males (120.5 vs 38 iu/ml) and females (99.8 vs 29.3 iu/ml) had higher mean IgE levels, as compared to nonatopic subjects ( P <0.0001). In our adult nonatopic sample, IgE levels did not differ with age ( P >0.05). At any age, nonatopic males had higher (38 iu/ml) mean IgE levels than nonatopic females (29.3 iu/ml) ( P <0.05). The comparison of normal IgE values (nonatopic subjects) from this study with those reported by other investigators revealed that Greek adult males and females had higher IgE levels than populations from other nations. Our results represent the first report on reference values regarding serum total IgE in Greek adults. 相似文献
110.
1049例育龄妇女下生殖道感染情况调查 总被引:2,自引:0,他引:2
目的了解育龄妇女下生殖道感染情况,为育龄女性生殖健康提供进一步的数据资料。方法对1049例来自健康体检中心的21~40岁育龄妇女的阴道后穹窿及宫颈分泌物标本进行检测,阴道清洁度、滴虫采用显微镜镜检法,淋球菌、解脲支原体、人型支原体、真菌采用培养法,沙眼衣原体则采用免疫层析法。检测结果进行统计学分析。结果女性生殖道感染的感染率为53.3%,其中混合感染率为9.8%,而清洁度异常率仅为28.4%;前三位病原体感染依次为解脲支原体(35.9%)、衣原体(18.1%)、真菌(6.7%)。结论女性生殖道感染情况严重,具有隐匿性,应加强对无症状感染的育龄妇女的监测。 相似文献