器官移植中免疫排斥机制概述

免疫排斥反应是器官移植成功的主要障碍之一,这种排斥反应存在于固有免疫和适应性免疫系统的相互联系和作用之中,会对移植物产生持续性的损伤.以固有免疫反应的活化为基础,组织和器官缺血再灌注过程中会导致严重的组织损伤,从而激发和扩大了适应性免疫反应.本文主要描述这些损害组织的分子途径、信号转导途径,熟悉排斥反应发生的靶点,从而为免疫抑制剂的发展和临床器官移植提供理论基础.     

Quantification of islet size and architecture

Human islets exhibit distinct islet architecture particularly in large islets that comprise of a relatively abundant fraction of α-cells intermingled with β-cells, whereas mouse islets show largely similar architecture of a β-cell core with α-cells in the periphery. In humans, islet architecture is islet-size dependent. Changes in endocrine cell mass preferentially occurred in large islets as demonstrated in our recent study on pathological changes of the pancreas in patients with type 2 diabetes. ( 1) The size dependency of human islets in morphological changes prompted us to develop a method to capture the representative islet distribution in the whole pancreas section combined with a semi-automated analysis to quantify changes in islet architecture. The computer-assisted quantification allows detailed examination of endocrine cell composition in individual islets and minimizes sampling bias. The standard immunohistochemistry based method is widely applicable to various specimens, which is particularly useful for large animal studies but is also applied to a large-scale analysis of the whole organ section from mice. In this article, we describe the method of image capture, parameters measured, data analysis and interpretation of the data.     

关于鼻内窥镜下鼻腔泪囊造孔术骨孔大小的探讨

目的:探讨鼻内窥镜下鼻腔泪囊造孔术中骨孔的大小对手术效果的影响,以寻求最合适的骨孔大小.方法:采用随机、单盲、平行研究方法.选取2010-01/10在株洲三三一爱尔眼科医院欲行鼻内窥镜下鼻腔泪囊造孔术治疗的慢性泪囊炎患者200例200眼随机分成两组:A组100眼:骨孔大小6mm×6mm(±2mm),B组100眼:骨孔大小10mm×10mm(±2mm)以上.手术时按分组做相应大小骨孔,术后观察各种不良反应及手术效果.结果:A组9例因骨壁太厚,3例因骨孔位置不在最佳位置需扩大骨孔,失访4例,最后进入观察病例84例,其中无效2例,有效82例.B组失访3例,最后进入观察病例97例,其中无效3例,有效94例,两组统计学上成功率无明显差别,A组患者术后反应更小效果更好.结论:鼻内窥镜下鼻腔泪囊造孔手术治疗慢性泪囊炎时6mm×6mm(±2mm)的骨孔大小是合适的,具有微创、术中出血少、术后不良反映少、且不影响手术效果的特点.     

Impact of iris pigment and pupil size in ultraviolet radiation cataract in rat

Purpose: To investigate the effect of iris pigment and pupil size in ultraviolet radiation (UVR)‐induced cataract. Methods: Brown‐Norway rats (pigmented) and Fischer‐344 rats (non‐pigmented) were unilaterally exposed in vivo to 5 kJ/m² UVR. Each strain was split into two groups, each receiving either mydriatic (tropicamide) or miotic (pilocarpine) eye‐drops. One week after exposure, the degree of ocular inflammation and damage in the anterior segment was determined. The lenses were extracted, photographed and the degree of forward light scattering (cataract) was quantified. Results: The cataract types differed between the two strains. All Fischer rats developed macroscopically identifiable UVR cataract while only 41% of Brown‐Norway rats did so. All groups except the miotic Brown‐Norway developed significant light scattering. The Fischer rats developed 3–4‐fold more lens light scattering than the Brown‐Norway rats. The miotic Fischer group exhibited significantly more light scattering than the mydriatic Fischer group. There was no significant difference in light scattering between the two Brown‐Norway groups. There was a correlation between ocular inflammation and degree of light scattering, with Brown‐Norway rats exhibiting less inflammation and lens light scattering. Conclusions: Pigmented rats develop less UVR cataract and less ocular inflammation than non‐pigmented rats. Pupil size plays a smaller role in UVR cataract development in pigmented rats than in non‐pigmented. The role of UVR‐induced ocular inflammation in cataract development is still ambiguous.     

Diabetic retinopathy screening: can the viewing monitor influence the reading and grading outcomes

Purpose

To evaluate the accuracy of different viewing monitors for image reading and grading of diabetic retinopathy (DR).

Design

Single-centre, experimental case series—evaluation of reading devices for DR screening.

Method

A total of 100 sets of three-field (optic disc, macula, and temporal views) colour retinal still images (50 normal and 50 with DR) captured by FF 450 plus (Carl Zeiss) were interpreted on 27-inch iMac, 15-inch MacBook Pro, and 9.7-inch iPad. All images were interpreted by a retinal specialist and a medical officer. We calculated the sensitivity and specificity of 15-inch MacBook Pro and 9.7-inch iPad in detection of DR signs and grades with reference to the reading outcomes obtained using a 27-inch iMac reading monitor.

Results

In detection of any grade of DR, the 15-inch MacBook Pro had sensitivity and specificity of 96% (95% confidence interval (CI): 85.1–99.3) and 96% (95% CI: 85.1–99.3), respectively, for retinal specialist and 91.5% (95% CI: 78.7–97.2) and 94.3% (95% CI: 83.3–98.5), respectively, for medical officer, whereas for 9.7-inch iPad, they were 91.8% (95% CI: 79.5–97.4) and 94.1% (95% CI: 82.8–98.5), respectively, for retinal specialist and 91.3% (95% CI: 78.3–97.1) and 92.6% (95% CI: 81.3–97.6), respectively, for medical officer.

Conclusion

The 15-inch MacBook Pro and 9.7-inch iPad had excellent sensitivity and specificity in detecting DR and hence, both screen sizes can be utilized to effectively interpret colour retinal still images for DR remotely in a routine, mobile or tele-ophthalmology setting. Future studies could explore the use of more economical devices with smaller viewing resolutions to reduce cost implementation of DR screening services.     

Synthetic food colors and neurobehavioral hazards: the view from environmental health research

Background: The proposition that synthetic food colors can induce adverse behavioral effects in children was first enunciated in 1975 by Feingold [Why Your Child Is Hyperactive. New York:Random House (1975)], who asserted that elevated sensitivity to food additives underlies the signs of hyperactivity observed in some children. Although the evidence suggested that some unknown proportion of children did respond to synthetic food colors, the U.S. Food and Drug Administration (FDA) interpreted the evidence as inconclusive. A study published in 2007 [McCann et al. Food additives and hyperactive behaviour in 3-year-old and 8/9-year-old children in the community: a randomised, double-blinded, placebo-controlled trial. Lancet 370:1560–1567 (2007)] drew renewed attention to the hypothesis because of the study’s size and scope. It led the FDA to review the evidence, hold a public hearing, and seek the advice of its Food Advisory Committee. In preparation for the hearing, the FDA reviewed the available evidence and concluded that it did not warrant further agency action.Objectives: In this commentary I examine the basis of the FDA’s position, the elements of the review that led to its decision and that of the Food Advisory Committee, and the reasons that this is an environmental health issue.Discussion: The FDA review confined itself, in essence, to the clinical diagnosis of hyperactivity, as did the charge to the committee, rather than asking the broader environmental question of behavioral effects in the general population; it failed to recognize the significance of vulnerable subpopulations; and it misinterpreted the meaning of effect size as a criterion of risk. The FDA’s response would have benefited from adopting the viewpoints and perspectives common to environmental health research. At the same time, the food color debate offers a lesson to environmental health researchers; namely, too narrow a focus on a single outcome or criterion can be misleading.     

成年中国人第5腰椎峡部Micro CT扫描的显微影像特点

背景：目前国内外学者对成年中国人第5腰椎峡部作了大量的应用解剖学研究,但研究结果各不相同,并且观测参数不系统、不完整,而对成年中国人第5腰椎峡部进行较系统的临床应用解剖与Micro CT扫描显微影像解剖对照研究国内外文献未见报道。 目的：观测成年中国人第5腰椎峡部Micro CT扫描显微影像解剖学及应用解剖学特点,以期为成年中国人第5腰椎峡部易患病性提供形态学依据。 方法：实验从成都医学院局解实验室随机选取60例成年中国人干燥、无破损第5腰椎标本,应用游标卡尺测量第5腰椎峡部的相关数据,并应用Micro CT的三维重建系统分析第5腰椎标本三维骨结构,并逐一测量与第5腰椎左、右侧峡部临床应用解剖观测的指标相对应的Micro CT扫描显微影像解剖参数。 结果与结论：在成年中国人第5腰椎标本观测：①左、右侧峡部上缘厚度分别为（4.27±177;0.99） mm,（4.25±177;0.98） mm。②左、右侧峡部下缘厚度分别为（7.31±177;1.23） mm,（7.29±177;1.25） mm。③左、右侧峡部内缘厚度分别为（6.61±177;0.33） mm,（6.59±177;0.36） mm。④左、右侧峡部外缘厚度分别为（8.65±177;0.27） mm,（8.59±177;0.33） mm。⑤左、右侧峡部上下缘距离分别为（11.10±177;3.14） mm,（11.07±177;3.11） mm。⑥左、右侧峡部上缘长度分别为（8.37±177;0.99） mm,（8.40±177;0.96） mm。⑦左、右侧峡部下缘长度分别为（4.71±177;0.71） mm,（4.73±177;0.62） mm。⑧左、右侧峡部内缘长度分别为（13.01±177;1.38） mm ,（13.04±177;1.36） mm。⑨左、右侧峡部外缘长度分别为（10.75±177;1.11） mm,（10.78±177;1.06） mm。游标卡尺与Micro CT所测的第5腰椎峡部左右侧的三维数值之间均差异无显著性意义。结果证实,对成年中国人第5腰椎峡部临床应用解剖测量值与Micro CT测量值之间具有统一性,左右侧腰椎峡部解剖值没有差异,Micro CT能为临床上第5腰椎的易患病性提供更为详尽准确的参考数据。     

流体力学泊肃叶定律在吸痰术中的应用

目的探讨流体力学泊肃叶定律在吸痰术中的应用。方法将收集痰液分成米汤样或白色泡沫样的稀痰与浊黄色凝成痂块的黏痰两种样品,在体外用小儿吸痰器测试6Fr、8Fr、10Fr三种管径吸痰管在四种吸引压力(-0.01、-0.02、-0.03、-0.04MPa)下的吸痰效果。结果 6Fr、8Fr、10Fr三种管径吸痰管,在吸引压为-0.01MPa时吸引5ml稀痰所需时间分别为38、12、5s;5ml黏痰时所需时间分别为600、600、357s。随着吸引压力由-0.01、向-0.02、-0.03、-0.04MPa的递增,6Fr、8Fr、10Fr三种吸痰管在15s内吸引黏痰的量分别为0、0、0、0.27ml;0.125、0.25、0.83、0.15ml和0.21、0.83、2.5、3.75ml。结论吸痰必需综合评估吸痰管管径、吸引负压与痰液黏稠度这三者的关系;吸痰术中,低负压与粗吸痰管等效于高负压与细吸痰管;当吸引负压与导管口径不变时,稀释痰液成为降低流阻的最佳选择。     

基于内部预试验方差及组间差值的样本量调整模拟

目的 通过盲态下内部预试验IPS样本量调整的模拟分析,探索协变量存在前提下有效控制Ⅰ型错误、保证检验效能的合理统计方法.方法 利用蒙特-卡罗法模拟存在协变量时的两阶段自适应设计过程,分别采用协方差分析法和方差分析法分析两阶段数据,采用合并P值法确定检验的最终结果,比较两种方法对Ⅰ型错误、检验效能值的影响.结果 采用方差分析的Ⅰ型错误膨胀较协方差分析要大,检验效能也较协方差分析略低,但是Ⅰ型错误的增大更明显.结论 根据第一阶段的方差和组间均值差调整样本量时,如果存在协变量,应采用协方差分析方法分别分析第一、二阶段的数据,然后采用合并P值法做出统计推断.