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排序方式: 共有2123条查询结果,搜索用时 15 毫秒
61.
62.
Julia Wilhelm Anna Birkenstock Vanessa Buchholz Astrid Müller Sherif Adel Aly Kerstin Gruner-Labitzke Hinrich Koehler Ralf Lichtinghagen Kirsten Jahn Adrian Groh Kai G. Kahl Martina de Zwaan Thomas Hillemacher Stefan Bleich Helge Frieling 《Obesity facts》2021,14(1):93
IntroductionDNA methylation constitutes one important epigenetic mechanism that regulates gene expression in human cells. With regard to obesity, bariatric surgery-induced weight loss has been associated with promoter methylation changes in several genes. Hyperleptinemia is a characteristic feature of obesity. The underlying regulating mechanisms have not yet been completely elucidated.MethodsWe investigated the methylation of the promoters of the leptin gene (LEP) and the leptin receptor gene (LEPR) as well as leptin expression in pre- and postbariatric surgery patients using a comparative cross-sectional design.ResultsOur results revealed significantly higher LEP promoter methylation patterns in prebariatric surgery patients compared to postoperatively. DNA methylation of the LEPR promoter was significantly higher in the postoperative group. Moreover, we found significantly higher leptin serum levels in patients before the bariatric surgery than afterwards.DiscussionThese findings strengthen the suggestion that there is an association between LEP expression and LEP methylation in obesity. We suggest that the epigenetic profile of LEP might be influenced by leptin serum levels in the form of a regulating feedback mechanism. 相似文献
63.
64.
Ayman Hammad Enas M. Hammad Samir Elhanbly Sherif R. El-Bassiony Mohammad F. Al-Harrass 《Autoimmunity》2016,49(1):31-40
There are no reports about the association of interleukin (IL)-17A and IL-17F gene polymorphism and susceptibility to pediatric systemic lupus erythematosus (pSLE). Objective: To examine the possible role of IL-17A rs2275913, IL-17F rs763780 and rs2397084 polymorphisms as risk factors for pSLE in a cohort of Egyptian children and to investigate their association with the clinico-pathological features including lupus nephritis (LN). Methods: Typing of IL-17A and IL-17F polymorphisms was done using restriction fragment length polymorphism for 115 children with SLE and 259 age- and sex-matched healthy controls. Results: No significant differences were found between pSLE patients and healthy controls for the allele and genotype frequencies of IL-17A rs2275913, IL-17F rs763780 and rs2397084 (p?>?0.05). However, the combined genotype GGAGAA and the haplotype GGA had significant association with pSLE (pc?=?0.042 and <0.001, respectively). The AA genotype of IL-17F rs763780 is more frequent in female patients (p?=?0.002) and the AA genotype of IL-17F rs2397084 is more associated with positivity of ds-DNA (p?=?0.007). No more associations were found for the demographic and clinical data of pSLE patients including risk of LN development, risk of non-remission, overall survival, activity and chronicity indices. Conclusion: The GGAGAA combined genotype and the GGA haplotype of IL-17A rs2275913, IL-17F rs763780 and rs2397084 can be considered risk factors for the development of SLE in Egyptian children. IL-17A rs2275913, IL-17F rs763780 and rs2397084 are not related to the LN development, SLE disease activity or overall survival. 相似文献
65.
Navin Wadehra Sherif Farag Brian Bolwell Patrick Elder Sam Penza Matt Kalaycio Belinda Avalos Brad Pohlman Guido Marcucci Ronald Sobecks Thomas Lin Steven Andrèsen Edward Copelan 《Biology of blood and marrow transplantation》2006,12(12):1343-1349
Busulfan (Bu)-based preparative regimens have not been extensively investigated in Hodgkin disease (HD). The purposes of this study were to investigate the toxicity and efficacy of a novel preparative regimen of Bu 14 mg/kg, etoposide 50-60 mg/kg, and cyclophosphamide 120 mg/kg in patients with primary refractory and relapsed HD. One hundred twenty-seven patients with a median age of 33 years (range, 14-67 years) underwent transplantation. The regimen was well tolerated, with 5.5% treatment-related mortality at 100 days after transplantation. With a median follow up of 6.7 years, the 5-year progression-free survival was 48 +/- 5%, and the 5-year overall survival was 51 +/- 5%. A Cox proportional hazards model identified refractory disease at time of transplantation as the only significant factor affecting relapse and overall survival, whereas disease bulk >10 cm affected overall survival. Five patients died between 5.3 and 9.3 years of late complications, including secondary myelodysplasia or acute myeloid leukemia, secondary solid malignancies, and pulmonary toxicity. This novel Bu regimen is comparable to other radiation-free preparative regimens in its effectiveness in the control of HD and with a low-risk of early treatment-related mortality. 相似文献
66.
Shieh WJ Hsiao CH Paddock CD Guarner J Goldsmith CS Tatti K Packard M Mueller L Wu MZ Rollin P Su IJ Zaki SR 《Human pathology》2005,36(3):303-309
This article describes the pathological studies of fatal severe acute respiratory syndrome (SARS) in a 73-year-old man during an outbreak of SARS in Taiwan, 2003. Eight days before onset of symptoms, he visited a municipal hospital that was later identified as the epicenter of a large outbreak of SARS. On admission to National Taiwan University Hospital in Taipei, the patient experienced chest tightness, progressive dyspnea, and low-grade fever. His condition rapidly deteriorated with increasing respiratory difficulty, and he died 7 days after admission. The most prominent histopathologic finding was diffuse alveolar damage of the lung. Immunohistochemical and in situ hybridization assays demonstrated evidence of SARS-associated coronavirus (SARS-CoV) infection in various respiratory epithelial cells, predominantly type II pneumocytes, and in alveolar macrophages in the lung. Electron microscopic examination also revealed coronavirus particles in the pneumocytes, and their identity was confirmed as SARS-CoV by immunogold labeling electron microscopy. This report is the first to describe the cellular localization of SARS-CoV in human lung tissue by using a combination of immunohistochemistry, double-stain immunohistochemistry, in situ hybridization, electron microscopy, and immunogold labeling electron microscopy. These techniques represent valuable laboratory diagnostic modalities and provide insights into the pathogenesis of this emerging infection. 相似文献
67.
Soliman S Sant S Nichol JW Khabiry M Traversa E Khademhosseini A 《Journal of biomedical materials research. Part A》2011,96(3):566-574
Porosity has been shown to be a key determinant of the success of tissue engineered scaffolds. A high degree of porosity and an appropriate pore size are necessary to provide adequate space for cell spreading and migration as well as to allow for proper exchange of nutrients and waste between the scaffold and the surrounding environment. Electrospun scaffolds offer an attractive approach for mimicking the natural extracellular matrix (ECM) for tissue engineering applications. The efficacy of electrospinning is likely to depend on the interaction between cells and the geometric features and physicochemical composition of the scaffold. A major problem in electrospinning is the tendency of fibers to accumulate densely, resulting in poor porosity and small pore size. The porosity and pore sizes in the electrospun scaffolds are mainly dependent on the fiber diameter and their packing density. Here we report a method of modulating porosity in three dimensional (3D) scaffolds by simultaneously tuning the fiber diameter and the fiber packing density. Nonwoven poly(ε-caprolactone) mats were formed by electrospinning under various conditions to generate sparse or highly dense micro- and nanofibrous scaffolds and characterized for their physicochemical and biological properties. We found that microfibers with low packing density resulted in improved cell viability, proliferation and infiltration compared to tightly packed scaffolds. 相似文献
68.
Impact of Varicocelectomy on Gonadal and Erectile Functions in Men with Hypogonadism and Infertility
IntroductionPrevious reports linked varicocele in infertile males with Leydig cell dysfunction and hypogonadism.AimThe aim of this study was to determine the impact of varicocelectomy on serum total testosterone (TT) level and erectile function in men with infertility and clinical varicocele.MethodsThis study included 141 heterosexual infertile men diagnosed to have clinical varicocele. They were divided into two groups: group 1 (103 men), who had microsurgical varicocelectomy, and group 2 (38 patients), who decided to pursue assisted reproduction procedures. All participants completed the International Index of Erectile Function (IIEF)‐5 questionnaire and underwent semen analysis. Serum levels of follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin, and TT were measured both at recruitment time and 6 months later.Main Outcome MeasureChanges in serum TT and IIEF‐5 following varicocelectomy.ResultsIn group 1, the mean TT level increased significantly post‐varicocelectomy (379.1 ± 205.8 to 450.1 ± 170.2 ng/dL, P < 0.0001). No similar change was found in group 2. Out of the 49 patients in group 1 with hypogonadism at baseline assessment (TT < 300 ng/dL), 37 (75.5%) exhibited a postoperative normalization of TT. However, only 3/15 hypogonadal men (20%) in group 2 had normal testosterone levels at the second visit. IIEF‐5 scores improved significantly postoperatively in patients with hypogonadism (17.1 ± 2.6 to 19.7 ± 1.8, P < 0.001). Neither operating vein diameter 3.6 ± 0.57 mm nor testicular size 10.46 ± 3.3 mL correlated with the mean change in TT (71.1 ± 101.2 ng/dL) (r = 0.162, P = 0.183 and r = ?0.077, P = 0.536, respectively).ConclusionsVaricocele is associated with hypogonadism in some infertile patients. Varicocelectomy significantly improves serum testosterone in infertile men, especially those with hypogonadism. This improvement in TT level may be reflected in the IIEF score. Zohdy W, Ghazi S, and Arafa M. Impact of varicocelectomy on gonadal and erectile functions in men with hypogonadism and infertility. 相似文献
69.
Tadros SF D'Souza M Zettel ML Zhu X Lynch-Erhardt M Frisina RD 《Neurobiology of aging》2007,28(7):1112-1123
Serotonin (5-HT) is a monoamine neurotransmitter. Serotonin may modulate afferent fiber discharges in the cochlea, inferior colliculus (IC) and auditory cortex. Specific functions of serotonin are exerted upon its interaction with specific receptors; one of those receptors is the serotonin 2B receptor. The aim of this study was to investigate the differences in gene expression of serotonin 2B receptors with age in cochlea and IC, and the possible correlation between gene expression and functional hearing measurements in CBA/CaJ mice. Immunohistochemical examinations of protein expression of IC in mice of different age groups were also performed. Gene expression results showed that serotonin 2B receptor gene was upregulated with age in both cochlea and IC. A significant correlation between gene expression and functional hearing results was established. Immunohistochemical protein expression studies of IC showed more serotonin 2B receptor cells in old mice relative to young adult mice, particularly in the external nucleus. We conclude that serotonin 2B receptors may play a role in the pathogenesis of age-related hearing loss. 相似文献
70.
Sherif Soliman Stefania Pagliari Antonio Rinaldi Giancarlo Forte Roberta Fiaccavento Francesca Pagliari Ornella Franzese Marilena Minieri Paolo Di Nardo Silvia Licoccia Enrico Traversa 《Acta biomaterialia》2010,6(4):1227-1237
A novel (scalable) electrospinning process was developed to fabricate bio-inspired multiscale three-dimensional scaffolds endowed with a controlled multimodal distribution of fiber diameters and geared towards soft tissue engineering. The resulting materials finely mingle nano- and microscale fibers together, rather than simply juxtaposing them, as is commonly found in the literature. A detailed proof of concept study was conducted on a simpler bimodal poly(ε-caprolactone) (PCL) scaffold with modes of fiber distribution at 600 nm and 3.3 μm. Three conventional unimodal scaffolds with mean diameters of 300 nm and 2.6 and 5.2 μm, respectively, were used as controls to evaluate the new materials. Characterization of the microstructure (i.e. porosity, fiber distribution and pore structure) and mechanical properties (i.e. stiffness, strength and failure mode) indicated that the multimodal scaffold had superior mechanical properties (Young’s modulus ~40 MPa and strength ~1 MPa) in comparison with the controls, despite the large porosity (~90% on average). A biological assessment was conducted with bone marrow stromal cell type (mesenchymal stem cells, mTERT-MSCs). While the new material compared favorably with the controls with respect to cell viability (on the outer surface), it outperformed them in terms of cell colonization within the scaffold. The latter result, which could neither be practically achieved in the controls nor expected based on current models of pore size distribution, demonstrated the greater openness of the pore structure of the bimodal material, which remarkably did not come at the expense of its mechanical properties. Furthermore, nanofibers were seen to form a nanoweb bridging across neighboring microfibers, which boosted cell motility and survival. Lastly, standard adipogenic and osteogenic differentiation tests served to demonstrate that the new scaffold did not hinder the multilineage potential of stem cells. 相似文献