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排序方式: 共有535条查询结果,搜索用时 15 毫秒
91.
Vaidya D Dobs A Gapstur SM Golden SH Hankinson A Liu K Ouyang P 《Metabolism: clinical and experimental》2008,57(6):782-790
The traditional lipid profile differs by sex hormone levels. However, associations of sex hormones with lipoprotein subfractions, which may more accurately represent metabolic pathways to atherosclerosis, are not well studied. We quantified the cross-sectional associations of endogenous sex hormones with lipoprotein subfractions in 3143 men and 2038 postmenopausal women who were not on hormone replacement therapy, aged 45 to 84 years, in the Multi-Ethnic Study of Atherosclerosis baseline examination. Particle sizes and numbers of very low-density (VLDL), low-density (LDL), and high-density (HDL) lipoproteins were measured by nuclear magnetic resonance. In both men and women, after multivariable adjustment, higher sex hormone binding globulin (SHBG) levels are associated with smaller, fewer VLDL; larger, fewer LDL; and larger, more numerous HDL particles, whereas higher endogenous estradiol levels are associated with smaller VLDL and smaller, more numerous HDL and LDL particles (all P < .05). Testosterone (adjusted for SHBG) is associated with smaller VLDL particles in men but not women (sex difference P = .040). Higher dehydroepiandrosterone levels are associated with more numerous, smaller VLDL particles only in women (sex difference P = .030, .004, respectively). In conclusion, we found sex differences in the association of endogenous androgens with lipoprotein particle sizes and numbers. Higher endogenous estradiol, but lower SHBG, is associated with a more atherogenic lipoprotein particle profile. These findings highlight the potential to improve the lipoprotein profile with sex hormones, but emphasize the intricacies of the interactions. 相似文献
92.
Knowledge of slip or cleavage planes can facilitate the fundamental understanding of mechanical properties of organic crystals important to pharmaceutical operations, such as tableting and milling. Slip/cleavage planes were frequently assigned based on attachment energy calculation. These crystallographic planes can also be identified by visualization of crystals characterized by stacking layers of high molecular density and often strengthened by two-dimensional hydrogen bonding network. Using 14 organic crystals exhibiting such layered structures, predicted slip planes by attachment energy calculation employing three force fields, Dreiding, cvff, and COMPASS, were compared to those identified by crystal structure visualization. Overall, slip/cleavage planes in <50% crystals were successfully predicted by attachment energy calculation. Thus predicted slip/cleavage planes by attachment energy calculation may not be always accurate and should be treated with caution. 相似文献
93.
94.
Wei Chen Shih-Ying Chang San Kiang William Early Srinivasa Paruchuri Divyakant Desai 《Journal of pharmaceutical innovation》2008,3(1):3-14
In this study, we describe the use of an innovative imaging system to measure and control the effect of nozzle operating parameters
on the characteristics of a spray. These characteristics, including spray pattern, droplet size distribution, and droplet
velocity, define the quality of the spray. They can have significant impact on the efficiency of the pan coating process and
the quality of the coat. Suspensions of different composition were used in this study, and the authors demonstrated that the
spray characteristics can be controlled with this approach.
The main conclusions from this study were:
Spray characterization can be a powerful tool for exploring and establishing the design space of nozzles operation in the
pan coating process. When scaling or transferring a spray coating process, the focus should be on maintaining consistent spray
qualities rather than limiting nozzle operating parameters to a range. This approach embraces the FDA concept of process analytical
technology (PAT) and design space (FDA, Guidance for industry PAT—A framework for innovative pharmaceutical development, manufacturing,
and quality assurance, 2004) for science-based operation flexibility.
The authors describe an imaging device that can be used to characterize the pattern, droplet velocities, and droplet size
distribution of a spray. This device, used at-line as a process analytical technology (PAT) tool, ensures the consistent performance
of spray nozzles used for coating processes. 相似文献
1. | The AA/Spray (atomization air/spray rate) and AA/PA (atomization air/pattern air) mass flow ratios were the key parameters that affect spray characteristics. Although viscosity can impact the spray, there was minimal impact within the viscosity range tested in this study. |
2. | With proper selection of the AA/Spray and AA/PA mass flow ratios, it was possible to generate sprays with consistent spatial distributions of volume flux with minimal variations of mean droplet size over the range of coating suspensions and spray rates studied. |
95.
Chan Kiang Lim Subramaniam Hemaroopini Shu Ying Gan Siew Mian Loo Jo Ring Low Vivien Yi Mian Jong Hsien Chuen Soo Chee Onn Leong Chun Wai Mai Chin Fei Chee 《Medicinal chemistry research》2016,25(8):1686-1694
Cancer is a leading cause of death worldwide. In our continuing search for new anticancer agents, four Malaysian Calophyllum species, namely C. castaneum, C. teysmannii, C. canum, and C. sclerophyllum, had been phytochemically studied to give compounds 1–12. All the isolated compounds were evaluated for their antiproliferative activity against nasopharyngeal (SUNE1, TW01, CNE1, HK1) and breast (HCC38, MDA-MB-231, MDA-MB-468, SKBR3) cancer cell lines via methyl thiazolyl tetrazolium cell viability assay. Among the tested compounds, isodispar B (1) showed a promising dose-dependent and a broad spectrum of cytotoxic effects on all the tested cancer cell lines; in particular, potent inhibitory activities were observed on nasopharyngeal cancer cell lines (SUNE1, TW01, CNE1, HK1), with IC50 values ranging from 3.8 to 11.5 µM. In comparison with 5-fluorouracil as positive control, compound 1 was found to exhibit at least sixfold much higher activity than the standard drug used against the nasopharyngeal cell lines. Compound 1 was later found to induce apoptotic cell death in nasopharyngeal cancer cells, as evidenced by ‘Cell Death Detection’ ELISAPLUS kit, and exhibited good cancer-specific cytotoxicity when tested with noncancerous NP460 cells. Meanwhile, compounds 2–12 displayed moderate to weak activities against the tested cancer cell lines. The findings have highlighted the therapeutic potential of compound 1 against nasopharyngeal cancer. 相似文献
96.
Renee Lay Hong Lim Li Kiang Tan Wai Fun Lau Maxey Ching Ming Chung Roseanne Dunn Heng Phon Too Lily Chan 《Clinical and Vaccine Immunology : CVI》2000,7(4):600-606
Four immunoreactive proteins, B.4, B.6, B.10, and B.M, with molecular weights ranging from 16,000 to 58,000, were observed from immunoblots of Mycobacterium tuberculosis total lysates screened with sera from individuals with active tuberculosis. These proteins were identified from microsequence analyses, and genes of proteins with the highest homology were PCR amplified and cloned into the pQE30 vector for expression studies. In addition, a 37.5-kDa protein, designated C17, was identified from a phage expression library of M. tuberculosis genomic DNA. Preliminary immunoblot assays indicated that these five resultant recombinant proteins could detect antibodies in individuals with active pulmonary and extrapulmonary tuberculosis. The overall ranges of sensitivities, specificities, positive predictive values, and negative predictive values for the recombinant antigens were 20 to 58, 88 to 100, 69 to 100, and 56 to 71%, respectively. The B.6 antigen showed preferential reactivity to antibodies in pulmonary compared to nonpulmonary tuberculosis serum specimens. All of these recombinant antigens demonstrated potential for serodiagnosis of tuberculosis. 相似文献
97.
Fiona C. Mansergh Paul F. Kenna Carmen Ayuso Anna-Sophia Kiang Peter Humphries G. Jane Farrar 《Human mutation》1998,11(3):244-251
A gene for juvenile onset, open angle glaucoma (JOAG) has been localized to chromosome 1q21-31 in several families. Mutations in the trabecular meshwork-induced glucocorticoid response protein (TIGR) gene, which maps to this region, recently have been found in families segregating both JOAG and a later onset form of primary open angle glaucoma (POAG). We have analysed the TIGR gene in two families; one Spanish family segregating autosomal dominant JOAG and an Irish family with a later onset form of autosomal dominant POAG. We have found a G-T transversion in the first base of codon 426 in all affected members of the Spanish family, which results in a valine to phenylalanine amino acid substitution. We have also found a G-A transition at the first base of codon 367 that segregates through all but one branch of the Irish family and results in a glycine to arginine amino acid substitution. Members of this family that carry the Gly367Arg change also share a common haplotype that is neither present in any of the unaffected members of the family, nor in the branch that does not segregate the mutation. Identification of further mutations in the TIGR gene increases its importance in the etiology of open angle glaucoma. Hum Mutat 11:244–251, 1998. © 1998 Wiley-Liss, Inc. 相似文献
98.
Shortage of cadaveric pancreata and requirement of immune suppression are two major obstacles in transplantation therapy of type 1 diabetes. Here, we investigate whether i.p. transplantation of alginate-encapsulated insulin-producing cells from the embryo-derived mouse embryo progenitor-derived insulin-producing-1 (MEPI-1) line could lower hyperglycemia in immune-competent, allogeneic diabetic mice. Within days after transplantation, hyperglycemia was reversed followed by about 2.5 months of normo- to moderate hypoglycemia before relapsing. Mice transplanted with unencapsulated MEPI cells relapsed within 2 weeks. Removal of the transplanted capsules by washing of the peritoneal cavity caused an immediate relapse of hyperglycemia that could be reversed with a second transplantation. The removed capsules had fibrotic overgrowth but remained permeable to 70?kDa dextrans and displayed glucose-stimulated insulin secretion. Following transplantation, the number of cells in capsules increased initially, before decreasing to below the starting cell number at 75 days. Histological examination showed that beyond day 40 post-transplantation, encapsulated cell clusters exhibited proliferating cells with a necrotic core. Blood glucose, insulin levels, and oral glucose tolerance test in the transplanted animals correlated directly with the number of viable cells remaining in the capsules. Our study demonstrated that encapsulation could effectively protect MEPI cells from the host immune system without compromising their ability to correct hyperglycemia in immune-competent diabetic mice for 2.5 months, thereby providing proof that immunoisolation of expansible but immune-incompatible stem cell-derived surrogate β-cells by encapsulation is a viable diabetes therapy. 相似文献
99.
Garg PK McClelland RL Jenny NS Criqui M Liu K Polak JF Jorgensen NW Cushman M 《Vascular medicine (London, England)》2011,16(4):247-252
Mechanisms underlying the role of lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) in atherosclerotic development are not completely understood. We evaluated the relationship of Lp-PLA(2) with endothelial dysfunction, an early manifestation of atherosclerosis, in a cohort without known clinical cardiovascular disease. A total of 2809 participants in the Multi-Ethnic Study of Atherosclerosis underwent plasma Lp-PLA(2) mass and activity measurement and brachial artery flow-mediated vasodilation testing. In adjusted linear regression models, higher Lp-PLA(2) mass and activity levels were not associated with lower endothelial function (-0.04%, p = 0.51 and -0.09%, p = 0.10, respectively). Among individuals with subclinical atherosclerosis based on ankle-brachial index (ABI) or carotid intima-media thickness (IMT), Lp-PLA(2) mass and activity were not associated with lower endothelial function (-0.03%, p = 0.88 and -0.31%, p = 0.16 for ABI < 1.00; 0.01%, p = 0.94 and -0.15%, p = 0.20 for abnormal carotid IMT). In summary, Lp-PLA(2) is not associated with endothelial dysfunction, suggesting its role in atherosclerosis development is primarily related to other factors. 相似文献
100.
Hao Yun Yap Ser Yee Lee Yaw Fui Alexander Chung Kiang Hiong Tay Albert Su-Chong Low Choon Hua Thng Krishnakumar Madhavan 《World journal of gastroenterology : WJG》2013,19(25):4087-4090
Gastrointestinal arterio-venous malformations are a known cause of gastrointestinal bleeding. We present a rare case of persistent rectal bleeding due to a rectal arterio-portal venous fistula in the setting of portal hypertension secondary to portal vein thrombosis. The portal hypertension was initially surgically treated with splenectomy and a proximal splenorenal shunt. However, rectal bleeding persisted even after surgery, presenting us with a diagnostic dilemma. The patient was re-evaluated with a computed tomography mesenteric angiogram which revealed a rectal arterio-portal fistula. Arterio-portal fistulas are a known but rare cause of portal hypertension, and possibly the underlying cause of continued rectal bleeding in this case. This was successfully treated using angiographic localizationand super-selective embolization of the rectal arterioportal venous fistula via the right internal iliac artery. The patient subsequently went on to have a full term pregnancy. Through this case report, we hope to high-light awareness of this unusual condition, discuss the diagnostic workup and our management approach. 相似文献