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Ischemia negatively affects mitochondrial function by inducing the mitochondrial permeability transition (MPT). The MPT is triggered by oxidative stress, which occurs in mitochondria during ischemia as a result of diminished antioxidant defenses and increased reactive oxygen species production. It causes mitochondrial dysfunction and can ultimately lead to cell death. Therefore, drugs able to minimize mitochondrial damage induced by ischemia may prove to be clinically effective. We analyzed the effect of carvedilol, a beta-blocker with antioxidant properties, on mitochondrial dysfunction. Carvedilol decreased levels of TBARS (thiobarbituric acid reactive substances), an indicator of oxidative stress, which is consistent with its antioxidant properties. Regarding cell death by apoptosis, although ischemia did increase caspase-8-like activity, there were no changes in caspase-3-like activity, which is activated downstream of caspase-8; this may indicate that the apoptotic cascade is not activated by 60 minutes of ischemia. We conclude that carvedilol protects ischemic mitochondria by preventing oxidative mitochondrial damage, and, by so doing, it may also inhibit the formation of the MPT pore.  相似文献   
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BACKGROUND: Some skin carcinomas may be very aggressive. Increased expression of the protein p53 has been associated with tumor aggressiveness. In this study, p53 expression was evaluated in basal cell carcinomas (BCC) and squamous cell carcinomas (SCC) with skull base invasion, and was compared to tumors with good outcome. STUDY DESIGN AND SETTING: Expression of p53 was immunohistochemically analyzed and it was reported as present or absent in 24 BCC and 11 SCC with skull base invasion. Control group (good outcome) included 23 BCC and 10 SCC. RESULTS: Expression of p53 was noted in 70.83% of BCC with skull base invasion, compared to 43.48% in the control group (P = 0.058). Regarding SCC, p53 positivity was noted in only 9.09% of SCC with skull base invasion, compared to 40.00% in the control group (P = 0.149). CONCLUSIONS: In this study, p53 expression was more common among BCC with skull base invasion, compared to controls with good outcome, and the difference was considered marginally significant. This proportion was reversed in SCC, but the difference was not statistically significant. EBM rating: B-3b.  相似文献   
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目的:建立大鼠颈动脉再狭窄模型,原位灌注固定取材。评价PTA后血管重塑(VR)的动态变化规律,定量分析血管重塑在血管再狭窄过程中的变化及作用。方法:制作70只SD雄性大鼠颈总动脉再狭窄模型,分原位灌注实验组、对照组,于术后1h、3、7、14、28和42天原位灌注固定取材,行HE染色、Masson染色,观察标本血管狭窄情况。结果:①血管重塑指数(VRI)在PTA后即刻最大,3天组明显降低,7天组稍有增大,其后不断减小,剩余血管腔面积百分比同VRI的变化曲线基本一致。②FFA后,血管腔面积总体呈逐渐缩小趋势,内弹力板围绕面积(IELA)1h组较对照组明显增大,3天组较1h组明显缩小,14、28、42天组较对照组明显缩小。外弹力板围绕面积(EELA)逐渐缩小。EELA、IELA的变化与血管腔面积变化呈正相关。③VRI与血管腔面积的变化呈正相关,新生内膜面积与剩余狭窄率、血管腔面积无直线相关。结论:再狭窄过程中存在扩张性重塑和收缩性重塑现象,管腔的狭窄与否取决于血管重塑指数的变化,而不是新生内膜的变化,新生内膜的形成是血管重塑过程中的一部分。IELA和EELA可作为判断管腔狭窄及评价血管重塑的指标。  相似文献   
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克罗米芬兴奋试验预测卵巢储备功能的价值   总被引:1,自引:0,他引:1  
目的探讨克罗米芬兴奋试验(CCT)在不孕妇女中预测卵巢储备功能的作用。方法对2001年1月至2005年2月就诊于广东省妇幼保健院的666例不孕症患者作为研究对象,分为A组(≥35岁)461例为高龄组,B组(〈35岁)205例为低龄组,另取156例年龄〈35岁、非女方不孕原因者作为对照组,对三组受试者进行CCT。结果CCT异常发生率A组、B组及对照组分别为27.76%、34.14%、2.56%,A组及B组与对照组比较差异均有非常显著性意义(P〈0.01)。基础卵泡刺激素(FSH)〈10IU/L、雌二醇(E2)〈180pmot/L的不孕患者CCT异常发生率分剐为17.46%、24.19%,均明显低于FSH≥10IU/L、E2≥180pmol/L患者的64.19%及39.4%(P〈0.01)。结论CCT预测卵巢储备功能较基础FSH更敏感,CCT可作为常规了解卵巢储备功能的一项检测方法。  相似文献   
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Methicillin-resistant Staphylococcus aureus (MRSA) is a frequent cause of infection after orthotopic liver transplantation (OLT). Colonization with MRSA is associated with a higher risk of infection. Previous studies have shown a high prevalence of MRSA colonization among OLT candidates. However, the risk of colonization with MRSA after OLT is still unclear. The objective of this study was to estimate the incidence and the factors associated with colonization with MRSA after OLT. This was a prospective cohort study including patients submitted to OLT between the years 2000 and 2002. Surveillance cultures of nasal swab specimens were performed within the 1st 72 hours of hospital admission and, subsequently, on weeks 2, 6, 13, and 26. Patients whose baseline cultures revealed nasal carriage of MRSA were excluded. A total of 60 patients were included in the study. The median follow-up was 72 days. A total of 9 patients (15%) became colonized. In multiple logistic regression analyses, the use of a urinary catheter for > or =5 days (P = .006), postoperative bleeding at the surgical site (P = .009), and preoperative use of fluoroquinolones (P = .08) were associated with a higher risk of colonization. Patients without any of these risk factors did not become colonized. In conclusion, nasal carriage of MRSA is frequently acquired after OLT. Periodic postoperative screening for MRSA carriage should be an integral component in programs designed to reduce nosocomial MRSA transmission in these patients. Further studies are needed to set up and validate a predictive model that could allow targeting postoperative screening to high-risk OLT recipients.  相似文献   
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Childhood-onset systemic lupus erythematosus (SLE) is often severe and has a serious long-term morbidity. Pediatric guidelines about its management do not exist. The French study group of childhood-onset SLE proposes recommendations about the investigation which are needed at diagnosis and during follow-up of SLE, in order to adjust the treatment according to the severity of the disease and to avoid unnecessary investigations.  相似文献   
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Leiomyosarcoma of the oral cavity is a very rare tumor associated with aggressive clinical behavior and low survival. In this paper, we report 2 cases of leiomyosarcoma, affecting the gingival mucosa of a 54-year-old female and the maxillary bone of a 63-year-old male. Histologically, the tumors were composed of variably oriented fascicles of spindle-shaped cells with cigar-shaped nuclei and eosinophilic cytoplasm. The lesions were treated by surgical resection. Immunoreactivity to anti-vimentin, anti-smooth muscle actin, anti-desmin, anti-laminin, and anti-muscle-specific actin antibodies were found; conversely, the tumor cells were negative for anti-S100 and AE1/AE3 proteins. This report emphasizes the role of immunohistochemical study for correct diagnosis of leiomyosarcoma.  相似文献   
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