活体生物萤光成像技术新进展

活体生物萤光成像技术(in vivo biolumines- cence imaging)是近年来发展起来的一项崭新的分子、基因表达的分析检测系统．与传统的检测方法相比具有巨大的优越性,堪称是分子基因检测领域的革命性技术．随着萤光成像设备的进一步完善以及转基因动物的构建开发,在欧美等发达国家活体生物萤光成像技术已被广泛地应用于感染、肿瘤免疫及治疗、自身免疫性疾病、器官移植、基因治疗、药物开发等实验领域．本文就活体生物萤光成像技术的发展和应用作如下综述．     

Luminance-modulated adaptation in the global flash mfERG: a preliminary study of early retinal functional changes in high-risk glaucoma patients

Purpose  

To investigate the association of the luminance-modulation global flash multifocal electroretinogram (mfERG) and other clinical assessments of vision in subsets of subjects at high risk of developing glaucomatous damage.     

Change in obesity‐related metabolic abnormalities associated with body mass index improvement through life‐style intervention: A meta‐regression

The reduction in body mass index standard deviation score (BMI‐SDS) associated with improvement in biomarkers relating to metabolic health in obese children is unknown. We aimed to establish the change in BMI‐SDS associated with improved inflammation, liver function, and insulin resistance to inform clinical guidelines for pediatric weight management interventions and to assess the efficacy of future trials. A large‐scale systematic review was conducted to identify relevant studies. Studies of children with a diagnosis of obesity according to defined BMI thresholds, participating in lifestyle interventions to reduce obesity, were included. Studies must have reported baseline (pre‐) and postintervention (or change of) BMI‐SDS and either fasting glucose, homeostatic model of insulin resistance (HOMA‐IR), alanine aminotransferase (ALT), C‐reactive protein (CRP), or interleukin‐6 (IL‐6). A series of meta‐regressions were conducted to establish links between BMI‐SDS change scores and change in metabolic markers of health. Sixty‐eight articles were identified. From the meta‐regression analyses, across all study subsets, greater mean falls in all four parameters, (HOMA‐IR, Glucose, ALT, and CRP) were observed with greater mean loss of BMI‐SDS, but the trends were only statistically significant for HOMA‐IR and CRP (P = .003; P = .021). However, we could not find minimum changes in BMI‐SDS that would ensure a fall in these outcomes. At this time, we are unable to recommend a definitive value of BMI‐SDS reduction needed to improve the markers of metabolic health. Future trials should aim to report additional indices of derived BMI values, which may better reflect changes in actual adiposity.     

L-精氨酸对任意型移植皮瓣组织中基质金属蛋白酶2和基质金属蛋白酶2抑制因子表达的影响

目的：观察L-精氨酸对任意型移植皮瓣组织中基质金属蛋白酶2、基质金属蛋白酶2抑制因子表达的影响，分析L-精氨酸对移植皮瓣保护作用的途径。方法：于2005—06／09在武汉大学人民医院动物实验室完成取材、组织学和组织化学实验；2005—10／2006—02在武汉大学医学院人体解剖与组织胚胎实验室完成图像分析、照相和统计学处理。①实验材料和分组：取Wistar大白鼠79只，按随机数字表法分为3组：正常对照组（n=5），仅接受生理盐水处理，不形成皮瓣，只切开皮肤；皮瓣模型组（n=37），形成皮瓣，接受生理盐水处理；L-精氨酸干预组（n=37），形成皮瓣，接受L-精氨酸处理。②实验评估：肉眼观察皮瓣成活情况，利用HPIAS-2000多媒体彩色病理图像分析系统求出皮瓣平均成活面积率。应用光镜观察皮瓣组织学变化；用免疫组织化学SP法检测基质金属蛋白酶2、基质金属蛋白酶2抑制因子抗原。比较各组免疫组织化学反应阳性颗粒的平均吸光度、阳性面积率并作统计学分析。结果：纳入85只大鼠，79只大鼠进入结果分析，皮瓣模型组和L-精氨酸干预组各有3只大鼠死亡。①术后7d，L-精氨酸干预组皮瓣成活面积率显著高于皮瓣模型组（P〈0．01）。②术后24h，72h皮瓣模型组皮瓣组织中基质金属蛋白酶2和基质金属蛋白酶2抑制因子呈强阳性表达，L-精氨酸干预组呈弱阳性或阴性，正常对照组呈阴性。③皮瓣模型组皮瓣组织中基质金属蛋白酶2和基质金属蛋白酶2抑制因子的平均吸光度及阳性面积率均显著高于L-精氨酸干预组和正常对照组（P〈0．01）。结论：外源性L-精氨酸可能通过抑制任意型移植皮瓣组织中基质金属蛋白酶2、基质金属蛋白酶2抑制因子的过度表达，提高任意型皮瓣的成活率。     

In vitro evaluation of platelet concentrates, prepared from pooled buffy coats, stored for 8 days after filtration

BACKGROUND: Posttransfusion complications can be prevented by pretransfusion removal of donor white cells from platelet concentrate. The filtration used for this removal seems to have little effect on platelet function and activation, but more information is needed on its effect on function during subsequent long-term storage of concentrate. STUDY DESIGN AND METHODS: The effect of prestorage filtration of buffy coat-prepared platelet concentrates (PCs) on platelet function, metabolism, and activation was investigated. A pool of three PCs, each made of four buffy coats, was split into three equal volumes; two were filtered over two different filters and the third served as a control. Variables monitored immediately after filtration and during the subsequent 8-day storage period at 22 degrees C included aggregation upon stimulation with collagen and/or ADP, platelet adhesion capacity to collagen and fibrinogen in flowing blood, nucleotide content of and nucleobase release by the platelets, expression of activation-dependent antigens, and beta-thromboglobulin release by the platelets. RESULTS: No differences were observed between the PCs filtered over two different filters and the nonfiltered control PCs immediately after filtration and during storage, except for a selective removal (20%) of beta-thromboglobulin by one filter. CONCLUSION: PCs prepared from a pool of four buffy coats can be filtered and subsequently stored for 8 days (starting +/− 24 hours after whole blood collection) without detriment to platelet function, metabolism, or activation.     

血红素氧合酶-1在器官移植中的保护作用

血红素氧合酶(heme oxygenase,HO)是体内唯一一种催化血红素分解代谢的限速酶,他可以氧化降解血红素,将其分解为一氧化碳、自由铁和胆绿素．血红素氧合酶-1(HO-1)是唯一可以被诱导的血红素氧合酶,近年来大量的研究发现HO-1具有抗炎、抗凋亡、抗增生反应等多种保护作用．HO-1不仅可以在机体生理状态下发挥作用,更为重要的是他可以在机体非正常状态包括应激状态下被诱导,被认为是在细胞受损时维持其氧化和抗氧化动态平衡的关键因素．本文就HO-1在器官移植研究领域的细胞保护作用作如下综述．     

Field-cycling relaxometry: medical applications

Relaxometry between 10 kHz and 200 MHz (0.2 mT and 4.7 T) with a field-cycling device and a high-field-strength magnetic resonance (MR) unit permitted the determination of longitudinal relaxation rates of tissues and chemical compounds at numerous field strengths. The resulting nuclear magnetic relaxation dispersion profiles allowed the prediction of tissue contrast and efficacy of contrast agents at any field strength. Pure T1 contrast of normal brain tissue and pathologic lesions (multiple sclerosis, astrocytoma) increased from low field strengths to a maximum between 10 and 20 MHz and decreased afterward. Quadripolar dips reflecting the interaction between water and nitrogen atoms of the protein backbone appeared at 2.15 and 2.8 MHz, reducing T1 and opening the possibility of shorter imaging times and better tissue discrimination at these field strengths. Furthermore, it was shown that zero T1 contrast between normal and pathologic tissue samples may exist at certain field strengths. Gadolinium diethylenetriaminepentaacetic acid and gadolinium tetraazacyclododecanetetraacetic acid provided different contrast enhancement depending on the field strength.