天然牛黄与培育牛黄的扫描电镜观察

天然牛黄(natural ox gallstone)为牛的胆结石,由于产量极少,供求困难,国内于1956年参照天然牛黄的主要成分制成人工牛黄(artificial ox gallstone),作为天然牛黄的代用品。从1974年以来,很多省区如吉林、广东、内蒙古等都先后进行了人工培育牛黄的试验,并试验成功培育牛黄(cultured ox gallstone)。其方法是用手术在牛胆囊内植入异物为核,促使胆汁成分的沉积与结石的形成,经过一段时间后,将异物取出,上面的沉积物即为培育牛黄。本文目的是探讨天然牛黄与培育牛黄的结构特征。     

Isoflurane protects cardiomyocytes and mitochondria by immediate and cytosol-independent action at reperfusion

Background and purpose:

The volatile anaesthetic isoflurane protects the heart from ischaemia and reperfusion (I/R) injury when applied at the onset of reperfusion [anaesthetic postconditioning (APoC)]. However, the mechanism of APoC-mediated protection is unknown. In this study, we examined the effect of APoC on mitochondrial bioenergetics, mitochondrial matrix pH (pH_m) and cytosolic pH (pH_i), and intracellular Ca²⁺.

Experimental approach:

Cardiac mitochondria from Wistar rats were isolated after in vivo I/R with or without APoC (1.4%-vol isoflurane, 1 minimum alveolar concentration), and mitochondrial permeability transition pore (mPTP) opening, mitochondrial membrane potential (ΔΨ_m), and oxygen consumption were assessed. In isolated cardiomyocytes and isolated mitochondria I/R injury was produced in vitro, with or without APoC (0.5 mM isoflurane). Intracellular Ca²⁺, pH_m, pH_i and ΔΨ_m were monitored with SNARF-1, TMRE and fluo-4, respectively. Myocyte survival was assessed when APoC was induced at pH 7.4 and 7.8. In isolated mitochondria oxygen consumption and ATP synthesis were measured.

Key results:

In vivo APoC protected against mPTP opening, slowed mitochondrial respiration and depolarized mitochondria. APoC decreased the number of hypercontracted cardiomyocytes at pH 7.4, but not at pH 7.8. APoC attenuated intracellular Ca²⁺ accumulation, maintained lower pH_m, and preserved ΔΨ_m during reoxygenation. Isoflurane did not affect the regulation of cytosolic pH. In mitochondria, APoC preserved ATP production rate and respiration.

Conclusions and implications:

At reperfusion, APoC inhibited mitochondrial respiration, depolarized mitochondria and acidified pH_m. These events may lead to inhibition of mPTP opening and, consequently, to preserved ΔΨ_m and ATP synthesis. This reduces intracellular Ca²⁺ overload and cell death.This article is commented on by Moncada, pp. 217–219 of this issue. To view this commentary visit http://dx.doi.org/10.1111/j.1476-5381.2010.00706.x and to view related papers in this issue by Puerta et al. and Kurz et al. visit http://dx.doi.org/10.1111/j.1476-5381.2010.00663.x and http://dx.doi.org/10.1111/j.1476-5381.2010.00656.x     

MDM2 SNP309 does not confer an increased risk to oral squamous cell carcinoma but may modulate the age of disease onset

The MDM2 SNP309 has been associated with increased expression of the protein which could suppress p53 function, and has been shown to modulate risk to cancer. We have previously shown that overexpression of MDM2 is a common event in oral cancers. In the present study, we determined the association between the MDM2 SNP309 polymorphism and oral cancer in 207 oral cancer patients and 116 normal subjects. We genotyped the MDM2 SNP309 by PCR-RFLP. Logistic regression was adapted to calculate odds ratios for MDM2 SNP309 polymorphism from univariate and multivariable adjusted models. Our results suggest that MDM2 SNP309 does not confer increased risk to oral cancer (OR=1.55, 95% CI=0.77-3.11). However, the GG/TG genotype was associated with later disease onset in women above 55 years of age. Collectively, our data suggests that MDM2 SNP309 may modulate the risk to oral cancer and is a modifier of the age at oral cancer onset in women above the age of 55 years.     

Physical activity of Aboriginal people in Canada

This paper summarizes available information on patterns of physical activity, their determinants and consequences, and the results of various interventions designed to increase the physical activity of Aboriginal peoples in Canada and the United States. There is a paucity of national data on this issue for Aboriginal peoples. The most recent data, from the First Nations Regional Longitudinal Health Survey of 2002-2003, indicate that 21% of adults (27% of men, 15% of women) were engaging in at least 30 min of moderate to vigorous physical activity on 4 d/week or more. The present paper highlights the unique challenges this group faces, underlining the need to integrate collective knowledge regarding how much physical activity is required for Aboriginal Canadians, and how this activity should be accomplished, to promote and maintain health. Efforts are currently underway to tailor Canada's physical activity guide for First Nations, Inuit, and Métis. Future research among Aboriginal groups should examine the minimal and optimal levels of physical activity required to achieve health benefits.     

Serum eosinophil cationic protein (ECP) is a sensitive measure for disease activity in atopic dermatitis

Atopic dermatitis (AD) is characterized by alterations in cellular and humoral immunity including elevated serum levels of IgE, IL-2 receptor (IL-2R) and eosinophil cationic protein (ECP). In order to evaluate the relevance of these serum parameters as indicators of disease activity, the concentrations of IgE, IL-2R and ECP were measured in serum samples of patients with an acute exacerbation of AD (n = 19) on admission to hospital and every 6 days up to discharge, and compared with those from normal non-atopic controls (n = 15). The severity of the disease in the AD patients was examined using an established clinical scoring system. On admission, AD patients showed significantly elevated serum levels of IgE, IL-2R and ECP compared with normal controls (P less than or equal to 0.0001). Clinical improvement was associated with a decrease of both the clinical score (P less than or equal to 0.001) and serum ECP levels (P less than or equal to 0.005). No significant changes in serum IgE and serum IL-2R were observed. In addition, there was a significant correlation between serum ECP and the clinical score (R = 0.67, P less than or equal to 0.001). These data indicate that serum ECP may be a helpful tool for monitoring disease activity in AD.     

Validity and reliablility of a voice-recognition game analysis system for field sports

The purpose of this study was to assess the ability of observers to use voice-recognition analysis to accurately classify gait transitions and quantify gait durations typical of team games. Inter-rater and intra-rater reliability was also determined. Four males were filmed performing pre-determined gait protocols. each comprising different sequences of walking, jogging, running and sprinting. Two operators independently classified gait transitions and the time spent in each gait was determined by the voice recognition system. All gait modes as measured by trained observers demonstrated statistically significant correlations (p < 0.01) to pre-determined measurement criteria. The mean absolute error for all gait transitions was less than half a second (0.32-0.36 s) with the maximum percentage error being approximately 4% for the walk, jog and run gaits and 10% for sprinting. Gait classification error was low at 1.9%. The intra-rater and inter-rater reliability was consistently high ranging from r = 0.87 to 0.99. In conclusion, observers using voicerecognition software provided valid measures of time spent in each of the four gait categories with 90% or better accuracy achieved.     

鲨鱼软骨粉对小鼠移植性淋巴瘤VEGF含量的影响及其与微血管的关系

目的研究鲨鱼软骨粉对小鼠移植性淋巴瘤组织中VEGF含量的变化及其与微血管的关系。方法建立移植性小鼠淋巴瘤SRS模型。治疗组 (n=6)喂鲨鱼软骨粉15d ,剂量54mg/d,对照组(n=8)用等量生理盐水代替。肿瘤称重 ,切片作Ⅷ因子相关抗原染色 ,用电视图象处理系统作肿瘤微血管密度计数。用ELISA法定量测定肿瘤中VEGF含量。结果治疗组肿瘤重量缩小 ,VEGF含量明显减少 ,且与肿瘤重量与微血管密度间呈正相关(r=0.886,r=0.91 ,P<0.05)。结论服鲨鱼软骨粉后SRS小鼠肿瘤生长抑制 ,微血管密度减少 ,这些变化与瘤组织中VEGF含量降低有密切关系。     

用流式细胞仪检测鲨鱼软骨粉提取物对大鼠微血管内皮细胞的作用

研究鲨鱼软骨粉提取物对大鼠肺微血管内皮细胞的影响,方法用流式细胞仪测定体外培养的肺微血管内皮细胞中细胞周期和细胞凋亡的变化。结果体外培养的微血管内皮细胞与鲨鱼软骨粉全成份、成份Ａ、成份Ｂ一起培养２４ｈ后经流式细胞仪检测发现,成份Ｂ使细胞周期Ｇ２－Ｍ期细胞明显减少,成份Ａ使凋亡细胞明显增加。