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排序方式: 共有557条查询结果,搜索用时 15 毫秒
1.
Products of the Frizzled family of tissue polarity genes have been identified as putative receptors for the Wnt family of signaling molecules. Wnt-signaling is implicated in the regulation of limb mesenchymal chondrogenesis, and our recent study indicates that N-cadherin and related activities are functionally involved in Wnt-7a-mediated inhibition of chondrogenesis. By using an in vitro high-density micromass culture system of chick limb mesenchymal cells, we have analyzed the spatiotemporal expression patterns and the effects on chondrogenesis of RCAS retroviral-mediated misexpression of Chfz-1 and Chfz-7, two Frizzled genes implicated in chondrogenic regulation. Chfz-1 expression was localized at areas surrounding the cartilaginous nodules at all time points examined, whereas Chfz-7 expression was limited to cellular aggregates during initial mesenchymal condensation, and subsequently was down-regulated from the centers toward the periphery of cartilage nodules at the time of chondrogenic differentiation, resembling the pattern of N-cadherin expression. Chondrogenesis in vitro was inhibited and limited to a smaller area of the culture upon misexpression of Chfz-7, but not affected by Chfz-1 misexpression. Analyses of cellular condensation and chondrogenic differentiation showed that the inhibitory action of Chfz-7 is unlikely to be at the chondrogenic differentiation step, but instead affects the earlier precartilage aggregate formation event. At 24 hr, expression of N-cadherin, a key component of the cellular condensation phase of chondrogenesis, was delayed/suppressed in Chfz-7 misexpressing cultures, and was limited to a significantly smaller cellular condensation area within the entire culture at 48 hr, when compared with control cultures. Chfz-1 misexpressing cultures appeared similar to control cultures at all time points. However, neither Chfz-1 nor Chfz-7 misexpression affected mesenchymal cell proliferation in vitro. These results suggest that Chfz-7 is active in regulating N-cadherin expression during the process of limb mesenchymal chondrogenesis and that Chfz-1 and Chfz-7 are involved in different Wnt-signaling pathways. 相似文献
2.
血管内皮功能障碍对肥胖伴高血糖患者胰岛分泌功能的影响 总被引:4,自引:0,他引:4
目的 探讨血管内皮功能障碍对胰岛 β细胞分泌功能的影响。 方法 正常体重(NW )组 81例 ,单纯肥胖 (Ob)组 14 0例 ,肥胖伴高血糖 (Ob HG)组 97例。测定体质指数 (BMI)、腰臀围比 (WHR)、血压、血脂、空腹血糖和胰岛素 (FBG和FIns)及餐后血糖和胰岛素 (2hBG和 2hIns)。采用稳态模式法评价胰岛素抵抗 (HOMA IR)和 β细胞功能 (HOMA β)。用高分辨率血管外超声测定肱动脉对血流介导的内皮依赖性血管扩张 (EDD)及硝酸甘油的扩张反应。 结果 与Ob组比较 ,Ob HG组WHR、血压、甘油三酯 (TG)、FIns、2hIns和HOMA IR等显著升高 ,HOMA β明显降低 ,并伴有EDD所标志的血管内皮功能显著下降。相关分析显示 ,β细胞功能与EDD在Ob HG组呈显著正相关 (r=0 2 5 9,P <0 0 5 ) ,在Ob组和NW组无显著相关。在对Ob HG组影响EDD的因素进行控制后 ,EDD仍与 β细胞功能显著相关 (r =0 4 5 8,P <0 0 1)。多元逐步回归分析表明影响 β细胞功能的主要因素在Ob HG组为FBG、FIns和EDD ,在Ob组为FBG和HOMA IR。 结论 内皮依赖性舒张功能障碍可能是导致肥胖者 β细胞功能衰退 ,引发 2型糖尿病 (T2DM )的重要危险因素。 相似文献
3.
Cevik MO 《Behavioral neuroscience》2003,117(4):774-784
Experiments 1 and 2 address the controversy regarding the reliability of methamphetamine effects on interval timing. A temporal discrimination procedure was used, in which the rats were reinforced for pressing the left or the right levers after short and long signals, respectively. Methamphetamine (0.5 mg/kg sc) severely disrupted operant performance at 20-100 min after injection, which disabled the measurement of drug effects on temporal perception (Experiment 1). The same dose of methamphetamine shifted the psychometric function to the left at 100-180 min after injection, indicating an increase in subjective durations (Experiment 2). Although these results confirm the role of dopamine in interval timing, that a change in the speed of a neural clock mediates the methamphetamine-induced change in temporal perception is still a working hypothesis. 相似文献
4.
5.
Ertugrul Uzar Harun Alp Mehmet Ugur Cevik Ugur F?rat Osman Evliyaoglu Adnan Tufek Yasar Altun 《Neurological sciences》2012,33(3):567-574
The aim of this study was to investigate the possible effects of ellagic acid in brain and sciatic nerve tissues of diabetic rats. Also, the impact of ellagic acid on catalase and paraoxonase (PON-1) activities, total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), malondialdehyde (MDA) and nitric oxide (NO) were examined. The rats were randomly divided into four groups, with eight rats each: Normal controls (not diabetic), only ellagic acid treated (ellagic acid controls, not diabetic), Diabetic controls (streptozotocin, diabetic), ellagic acid-treated diabetic (streptozotocin?+?ellagic acid). After a 4?week experiment, rats were sacrificed, and biomarkers for oxidative stress in the brain and sciatic nerve tissues of the rats were measured. There was significant depletion in the PON-1, catalase, and TAS levels in the brain and sciatic nerve tissues compared to the control groups (for both parameters, p?<?0.05). The values of catalase, PON-1 and TAS reversed back to normal levels in ellagic acid-treated diabetic rats compared to untreated diabetic rats (for both parameters, p?<?0.05). The levels of MDA, TOS, NO and, OSI in the brain and sciatic nerve tissues were higher in untreated diabetic rats compared to control group (for both parameters p?<?0.05). However, MDA, TOS, OSI, and NO levels were found to be significantly reduced in the ellagic acid-treated diabetic group compared to the untreated diabetic group in these tissues (for both parameters, p?<?0.05). In conclusion, the results of the present study suggested that ellagic acid exhibits neuroprotective effects against oxidative damage in diabetic rats. 相似文献
6.
目的:探析异甘草酸镁联合降脂治疗非酒精性脂肪型肝炎疗效及对肝功能影响。方法以该院2011年5月-2014年10月期间所收治92例非酒精性脂肪型肝炎患者展开研究,对照组给予以调脂为主综合治疗,观察组加用异甘草酸镁,比较两组治疗前后PCⅢ、C-ⅠV、HA及ALT、AST、TBIL、γ-GT等肝纤维化指标。结果两组治疗前各肝纤维化指标的比较无统计学意义(P>0.05);治疗后,观察组PCⅢ、C-ⅠV、HA等指标均显著降低,与治疗前比较差异有统计学意义(P<0.05),与对照组治疗后的组间比较差异有统计学意义(P<0.05)。组间比较上,两组治疗前ALT、AST、TBIL、γ-GT等肝功能指标的比较无统计学意义(P>0.05),治疗后两组各指标的比较差异有统计学意义(P<0.05);组内比较上,两组治疗前后各指标的比较差异有统计学意义(P<0.05)。结论异甘草酸镁可保护肝细胞,与降脂治疗联合应用于NASH患者可有效抑制肝细胞纤维化,促进肝功能的恢复,应用价值高。 相似文献
7.
Mehmet Rasih Sonsoz Aytac Oncul Erdem Cevik Huseyin Orta Mustafa Yilmaz Elif Ayduk Govdeli Asli Nalbant Zeynep Gizem Demirtakan Mirac Tonyali Damla Durmus Ilkay Anakli Ozlem Polat Yunus Catma Naci Senkal Alpay Medetalibeyoglu Murat Kose Samim Emet Tufan Tukek 《The American journal of the medical sciences》2021,361(5):591-597
BackgroundThe information on electrocardiographic features of patients with coronavirus disease 2019 (COVID-19) is limited. Our aim was to determine if baseline electrocardiographic features of hospitalized COVID-19 patients are associated with markers of myocardial injury and clinical outcomes.MethodsIn this retrospective, single center cohort study, we included 223 hospitalized patients with laboratory-confirmed COVID-19. Clinical, electrocardiographic and laboratory data were collected and analyzed. Primary composite endpoint of mortality, need for invasive mechanical ventilation, or admission to the intensive care unit was assessed.ResultsForty patients (17.9%) reached the primary composite endpoint. Patients with the primary composite endpoint were more likely to have wide QRS complex (>120 ms) and lateral ST-T segment abnormality. The multivariable Cox regression showed increasing odds of the primary composite endpoint associated with acute respiratory distress syndrome (odds ratio 7.76, 95% CI 2.67–22.59; p < 0.001), acute cardiac injury (odds ratio 3.14, 95% CI 1.26–7.99; p = 0.016), high flow oxygen therapy (odds ratio 2.43, 95% CI 1.05–5.62; p = 0.037) and QRS duration longer than >120 ms (odds ratio 3.62, 95% CI 1.39–9.380; p = 0.008) Patients with a wide QRS complex (>120 ms) had significantly higher median level of troponin T and pro-BNP than those without it. Patients with abnormality of lateral ST-T segment had significantly higher median level of troponin T and pro-BNP than patients without.ConclusionsThe presence of QRS duration longer than 120 ms and lateral ST-T segment abnormality were associated with worse clinical outcomes and higher levels of myocardial injury biomarkers. 相似文献
8.
Gülseren Baran Ayse Erbay Hürrem Bodur Pinar Ongürü Esragül Akinci Neriman Balaban Mustafa A Cevik 《International journal of infectious diseases》2008,12(1):16-21
OBJECTIVES: To identify the risk factors for nosocomial imipenem-resistant Acinetobacter baumannii (IRAB) infections. METHODS: A prospective case-control study, set in an 1100-bed referral and tertiary-care hospital, of all patients who had nosocomial A. baumannii infections between January 1 and December 31, 2004. Only the first isolation of A. baumannii was considered. RESULTS: IRAB was isolated from 66 (53.7%) patients and imipenem-sensitive Acinetobacter baumannii (ISAB) was isolated from 57 (46.3%) patients during the study period. The mean duration of hospital stay until A. baumannii isolation was 20.8+/-13.6 days in IRAB infections, whereas it was 15.4+/-9.4 days in ISAB infections. Of the patients, 65.2% with IRAB infections and 40.4% with ISAB infections were followed at the intensive care unit (ICU). Previous carbapenem use was present in 43.9% of the patients with IRAB and 12.3% of the patients with ISAB infection. In univariate analysis female sex, longer duration of hospital stay until infection, ICU stay, emergent surgical operation, total parenteral nutrition, having a central venous catheter, endotracheal tube, urinary catheter or nasogastric tube, previous antibiotic use, and previous administration of carbapenems were significant risk factors for IRAB infections (p<0.05). In multivariate analysis, longer duration of hospital stay until A. baumannii isolation (odds ratio (OR) 1.043; 95% confidence interval (CI) 1.003-1.084; p=0.032), previous antibiotic use (OR 5.051; 95% CI 1.004-25.396; p=0.049), and ICU stay (OR 3.100; 95% CI 1.398-6.873; p=0.005) were independently associated with imipenem resistance. CONCLUSIONS: Our results suggest that the nosocomial occurrence of IRAB is strongly related to an ICU stay and duration of hospital stay, and that IRAB occurrence may be favored by the selection pressure of previously used antibiotics. 相似文献
9.
Tevfik Berk Bildaci Halime Cevik Birnur Yilmaz Guldeniz Aksan Desteli 《Journal of Medical Ultrasonics》2018,45(3):425-430
Purpose
Adenomyosis is the presence of endometrial glandular and stromal tissue in the myometrium. This phenomenon can be the cause of excessive bleeding and menstrual pain in premenopausal women. Diagnosis of adenomyosis may present difficulty with conventional methods such as ultrasound and magnetic resonance imaging. Frequently, diagnosis is accomplished retrospectively based on the hysterectomy specimen.Materials and methods
This is a prospective case control study done in vitro on 90 patients’ hysterectomy specimens. Acoustic radiation force impulse (ARFI) and color elastography were used to determine the elasticity of hysterectomy specimens of patients undergoing indicated surgeries. Based on histopathological examinations, two groups were formed: a study group (n = 28—with adenomyosis) and a control group (n = 62—without adenomyosis).Results
Elasticity measurements of tissue with adenomyosis were observed to be significantly higher than measurements of normal myometrial tissue (p < 0.01). Uterine fibroids were found to have higher values on ARFI study compared to normal myometrial tissues (p < 0.01).Conclusion
The findings lead to the conclusion that adenomyosis tissue is significantly softer than the normal myometrium. ARFI was found to be beneficial in differentiating myometrial tissue with adenomyosis from normal myometrial tissue. It was found to be feasible and beneficial to implement ARFI in daily gynecology practice for diagnosis of adenomyosis.10.
Nevin Karakus Serbulent Yigit Gulsum Semiha Kurt Betul Cevik Osman Demir Omer Ates 《Human immunology》2013