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991.
992.
河南地区原发性不孕症流行病学和临床研究 总被引:6,自引:1,他引:6
我们在河南省二市五县进行了原发性不孕症流行病学调查。调查结果原发性不孕症患病率为1.96%,原发性不育(含习惯性流产)为2.01%。并对321对原发性不孕症夫妇进行了病因分析,属男方原因的占26.8%,属女方原因的占49.2%,夫妇双方原因者占24%。按原发性不孕症病因分类分析,首要因素男方为精索静脉曲张(10.9%),女方为排卵异常(32.08%)。 相似文献
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996.
Age-Related Bone Mineral Density, Accumulated Bone Loss Rate and Prevalence of Osteoporosis at Multiple Skeletal Sites in Chinese Women 总被引:18,自引:0,他引:18
Er-Yuan Liao Xian-Ping Wu Xiao-Ge Deng Gan Huang Xu-Ping Zhu Zhao-Feng Long Wen-Bo Wang Wei-Li Tang Hong Zhang 《Osteoporosis international》2002,13(8):669-676
We investigated the age-related bone mineral density (BMD), accumulated bone loss rate (ABLR) and the prevalence of osteoporosis
at different skeletal sites in Chinese women. BMD was measured at the anteroposterior (AP) spine, supine lateral spine (areal
BMD at the midarea [mLat] and the whole region [Lat], volumetric BMD at the middle region [MVD] and total region [TVD]), hip
(femoral neck [FN], trochanter [Troc] and Ward’s triangle [Ward’s]) and forearm (radius + ulna ultradistal [RUUD], 1/3 region
[RU1/3] and total region [RUT]) using a dual-energy X-ray absorptiometry (DXA) fan-beam bone densitometer (Hologic QDR 4500A)
in 2702 females aged from 5 to 96 years old. Data were analyzed by eight different regression models. We found that the cubic
regression model was the best for describing age-related changes in BMD. The coefficients of determination (R
2) of the fitting curve were 0.398 to 0.612 (p= 0.000). The data were then analyzed by 5-year age groups. This showed that the earliest peak BMD was at the age of 20–24
years at Troc and Ward’s, and the latest at the age of 40–44 years at RU1/3 and RUT of the distal forearm. Compared with BMD,
the ABLRs were highest at Ward’s (−66.2%) and the lowest at RU1/3 of the distal forearm (−31.3%) in subjects over 80 years
old. The prevalence of osteoporosis at at least one site in these women was 0.5 ± 0.4% in those 30–39, 4.6 ± 4.4% in those
40–49, 23.9 ± 13.3% in those 50–59, 56.3 ± 20.3% in those 60–69, 71.8 ± 16.7% in those 70–79 and 83.2 ± 12.1% those over 80
years of age, respectively. The prevalence of osteoporosis in these women was 8.6–11.1% at the age of 40–49 and 36.5–40.6%
at the age of 50–59 at the lateral spine regions (mLat, Lat, MVD and TVD), and 0.5–3.7% at the age of 40–49 and and 3.9–21.7%
at the age of 50–59 years at the other skeletal sites (AP, FN, Troc, Ward’s, RUUD, RU1/3 and RUT). Significant differences
were found in the prevalence of osteoporosis between the lateral spine regions and other skeletal sites (p<0.001) at the age of 40–59 years. In summary, we demonstrated significant age-related differences in peak BMD, ABLR and osteoporosis
prevalence among various skeletal sites. Our data suggest that the supine lateral spine is the most sensitive site for the
diagnosis of osteoporosis, especially in the early menopausal period, although the prevalence of osteoporosis varied with
age and with different sites measured.
Received: 20 November 2001 / Accepted: 13 February 2002 相似文献
997.
Structure-activity relationships for inhibition of human 5alpha-reductases by polyphenols 总被引:11,自引:0,他引:11
The enzyme steroid 5 alpha-reductase (EC 1.3.99.5) catalyzes the NADPH-dependent reduction of the double bond of a variety of 3-oxo-Delta(4) steroids including the conversion of testosterone to 5 alpha-dihydrotestosterone. In humans, 5 alpha-reductase activity is critical for certain aspects of male sexual differentiation, and may be involved in the development of benign prostatic hyperplasia, alopecia, hirsutism, and prostate cancer. Certain natural products contain components that are inhibitors of 5 alpha-reductase, such as the green tea catechin (-)-epigallocatechin gallate (EGCG). EGCG shows potent inhibition in cell-free but not in whole-cell assays of 5 alpha-reductase. Replacement of the gallate ester in EGCG with long-chain fatty acids produced potent 5 alpha-reductase inhibitors that were active in both cell-free and whole-cell assay systems. Other flavonoids that were potent inhibitors of the type 1 5alpha-reductase include myricetin, quercitin, baicalein, and fisetin. Biochanin A, daidzein, genistein, and kaempferol were much better inhibitors of the type 2 than the type 1 isozyme. Several other natural and synthetic polyphenolic compounds were more effective inhibitors of the type 1 than the type 2 isozyme, including alizarin, anthrarobin, gossypol, nordihydroguaiaretic acid, caffeic acid phenethyl ester, and octyl and dodecyl gallates. The presence of a catechol group was characteristic of almost all inhibitors that showed selectivity for the type 1 isozyme of 5 alpha-reductase. Since some of these compounds are consumed as part of the normal diet or in supplements, they have the potential to inhibit 5 alpha-reductase activity, which may be useful for the prevention or treatment of androgen-dependent disorders. However, these compounds also may adversely affect male sexual differentiation. 相似文献
998.
Effects of Sucrose and Trehalose on the Preservation of the Native Structure of Spray-Dried Lysozyme 总被引:2,自引:0,他引:2
Purpose. To investigate the effects of sucrose, trehalose, sucrose/dextran mixtures, and sucrose/trehalose mixtures on the preservation of the native structure of spray-dried lysozyme in the solid state.
Methods. The intensity of the -helical band and the melting enthalpies (Hm ) of spray-dried lysozyme in the dried form and in aqueous solution were obtained using second derivative FTIR and differential scanning calorimetry (DSC) respectively.
Results. The intensity of the -helical band and the H m of spray-dried lysozyme obtained were linearly correlated and both suggest that the stabilization of lysozyme in the dried form was excipient concentration-dependent with a close to maximum stabilization being conferred by sucrose or trehalose at a mass ratio 1–2 (sugar:enzyme). Sucrose appeared to be more effective than trehalose on a weight by weight basis whilst stabilizing effects of dextran/sucrose or trehalose/sucrose mixtures were found to be additive.
Conclusion. Dehydration during spray drying was considered the main stress to the denaturation of lysozyme. A major effect of the sugars in protecting lysozyme against dehydration was attributable to hydrogen bonding between the sugar and protein molecules, which lead to an increase in the change in the negative value of the free energy between native and denatured states. 相似文献
999.
Purpose. DB75 [2,5-bis(4-amidinophenyl)furan] is a promising antimicrobial agent although it has poor oral potency. In contrast, its novel prodrug, 2,5-bis(4-amidinophenyl)furan-bis-O-methyl- amidoxime (DB289), has excellent oral potency. The mechanisms of transport of DB289 and DB75 across intestinal epithelium have been investigated in these studies to understand differences in their oral potency.
Methods. Caco-2 cell monolayers were used as an in vitro model to examine the mechanisms of transport of DB289 and DB75. Samples collected from the transport studies were quantified using high-performance liquid chromatography with ultraviolet and fluorescence detection.
Results. A low permeability coefficient (3.8 × 10–7 cm/s for transport in apical [AP] to basolateral [BL] direction) and high sensitivity to extracellular Ca2+ suggest that AP to BL transport of DB75 across Caco-2 cell monolayers occurs predominantly via a paracellular route. DB289 has an 85-fold higher transport rate (322.0 × 10–7 cm/s for transport in the AP to BL direction) across Caco-2 monolayers than that of DB75. This, with its insensitivity to extracellular Ca2+ indicates that AP to BL transport of DB289 across Caco-2 cell monolayers occurs predominantly via a transcellular route.
Conclusions. DB75 is transported across Caco-2 cell monolayers predominantly via paracellular pathways, whereas the prodrug DB289 is transported via transcellular pathways. This could account for the much higher oral activity of DB289 over DB75. 相似文献
1000.