Bacterial Contamination of Tissue Allografts – Experiences of the Donor Tissue Bank of Victoria

The aim of this study is to report the experience of the Donor Tissue Bank of Victoria with bacteria isolated from musculoskeletal, skin and cardiac allografts retrieved from cadaveric donors. The results of all quality control samples for bacterial culture, taken during retrieval and processing of allografts at the DTBV for a 12 month period, were extracted and analysed. It was found that 15.7% of skin, 15.1% of heart valves and 5.8% of musculoskeletal samples had positive culture results. The number and types of organisms isolated varied with tissue type. The most commonly isolated organisms were Staphylococcus species (including S. aureus). The identity of the isolate and the number of positive specimens from the same donor were considerations in the decision concerning the suitability of tissue for subsequent implantation.     

HLA分型方法进展

传统的HLA分型方法主要是血清学和细胞学方法,分型准确性较差,且不能进行亚型分析。随着PCR技术及基因芯片技术等分子生物学技术的出现、发展,HLA基因分型得到了迅速的发展,各具特点的HLA分型技术不断出现,使HLA的分型更加准确、精细、简便、实用,为临床推广应用打下了基础。     

HLA—G研究进展

ＨＬＡ－Ｇ分子属ＭＨＣ Ⅰ类非典型分子（ＭＨＣ Ⅰｂ）组织特异性地高表达于胎母界面的滋养层细胞,ＭＨＣⅠ、Ⅱ类抗原是缺乏的,ＨＬＡ－Ｇ分子通过ＮＫ细胞受体抑制ＮＫ细胞杀伤性,并作为ＣＤ８＾＋细胞毒抑制性Ｔ细胞的识别和激活因子,抑制ＣＴＬ的杀伤作用,ＨＬＡ－Ｇ在胎母耐受中发挥重要作用。     

The PAXgene? Tissue System Preserves Phosphoproteins in Human Tissue Specimens and Enables Comprehensive Protein Biomarker Research

Precise quantitation of protein biomarkers in clinical tissue specimens is a prerequisite for accurate and effective diagnosis, prognosis, and personalized medicine. Although progress is being made, protein analysis from formalin-fixed and paraffin-embedded tissues is still challenging. In previous reports, we showed that the novel formalin-free tissue preservation technology, the PAXgene Tissue System, allows the extraction of intact and immunoreactive proteins from PAXgene-fixed and paraffin-embedded (PFPE) tissues. In the current study, we focused on the analysis of phosphoproteins and the applicability of two-dimensional gel electrophoresis (2D-PAGE) and enzyme-linked immunosorbent assay (ELISA) to the analysis of a variety of malignant and non-malignant human tissues. Using western blot analysis, we found that phosphoproteins are quantitatively preserved in PFPE tissues, and signal intensities are comparable to that in paired, frozen tissues. Furthermore, proteins extracted from PFPE samples are suitable for 2D-PAGE and can be quantified by ELISA specific for denatured proteins. In summary, the PAXgene Tissue System reliably preserves phosphoproteins in human tissue samples, even after prolonged fixation or stabilization times, and is compatible with methods for protein analysis such as 2D-PAGE and ELISA. We conclude that the PAXgene Tissue System has the potential to serve as a versatile tissue fixative for modern pathology.     

Tissue expansion: dividend or loan?

Epidermal mitotic activity during tissue expansion has been assessed in the guinea pig using tritiated thymidine and other confirmatory techniques. Implant inflation results in a threefold elevation of epidermal mitotic activity within 24 hours, followed by a gradual return to normal baseline over 2 to 5 days. Implant deflation, conversely, causes a transient decrease in epidermal mitotic activity. Neither of these phenomena has been previously described. It confirms previous animal studies which illustrate the highly responsive nature of the epidermis to physical stimuli and supports the view that tissue expansion is a highly useful manipulation of normal physiologic processes.     

Typing of Yersinia pestis isolates from the state of Ceará, Brazil

AIMS: To investigate whether modifications in Yersinia pestis isolates from three plague foci from the state of Ceará, Brazil, had occurred over the years as a consequence of genetic adaptation to the environment. METHODS AND RESULTS: The isolates were studied with respect to susceptibility to antimicrobial drugs, plasmid and protein profiling, pigmentation on Congo red-agar plates, and the presence of some pathogenicity genes using PCR. Most of the expected virulence markers were detected in the cultures examined. There was no evidence of any alteration that could be associated with their origin (patients, rodents and fleas) or period of isolation (1971-1997). CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY: Phenotypic or genotypic changes were not detected in the cultures examined. However, the results obtained will serve as a reference to follow the evolution of Y. pestis in these foci.     

HLA 抗原的DNA 分型

HLA系统定位于6p2l.3, 是人体内最复杂的遗 传多态性系统,在免疫调控过程中发挥重要作用。 HLA I类基因区域包括HLA-A, B, C, E, F, G基因 和11个假基因“‘’。HLA一A, B和C基因座编码A, B 和C抗原a链(44kd),它通过第三个功能区与受痊于 第15号染色体的月,微球蛋白链(12kd）作非共价结 合构成杭原分子,其多态性取决于。链的第一、二功能 区。HLA-E, F和G基因编码I类样产物,其功能未 明。I类抗原分布于任何有核全』饱表面,主要参与提 供外来伉原给T细胞毒细胞「’“’。HLA II类基因座在 HLA-D区,主要包括HLA-DR, DQ和DP三个}2 区。DR亚区有6个基因座：DRA, DRB1, DPB2, DRB3, DRB4和DRB5, 其中DRB2为假基因;DQ 亚区有4个居因座：DQA1, DQB1, DQA2和DQB2, 其中DQA2和DQB2未知有产物表达;DP亚区也 有4个基因座：DPA1, DPB1, DPA2和DPB2,其 中DPA2和DPB2为假基因。此外,还有DO和DN 两个新亚区,各具有DOB和DNA（注意勿与脱氧核塘 核酸的缩写DNA相混淆）,分别产生DO(链和DNa 链「‘’。11类抗原HLA-DR, DQ和DP存在于B淋巴 细胞、巨噬细胞和激活的T淋巴细胞表面, 由。链 (32-35kd）和R链(28-30kd）非共价组成。。链无 多态性或多态性程度不高,R链的第一功能区呈现高 度多态性。11类抗原参与提皇外来伉原给T辅助细 胞,后者在识别外来伉原的同时识别HLA 11类坑 原「,,’。据1987年第十届国际组织相容性试验专题会 议报道,HLA系统检出148种抗原特异性,其中A基 因座24种,B基因座52种,C基因座11种,D区26 种,DR亚区20种,DQ亚区9种和DP亚区6种。 HLA-A, B, C, DR和DQ抗原系由特异性同种异 体抗血清检出,HLA-D和DP抗原则由纯合分型细胞 (HTC)和预致敏淋巴细胞分型(PLT）方法检出,两者 是以混合淋巴细胞培养(MLC）方法为基础的。近年 发展用蛋白质化学方法研究HLA系统抗原多态性L77o 自1975年Southern印迹法〔247间世后,运用HLA系 统基因探针通过分析限制性片段长度多态性(Restriction Fragment Length Polymorphism, RFLP）在DNA. 水平上进行分型。八十年代中期开始,聚合酶链反应 (Polymerase Chain Reaction, PCR）技术的创立为分 子生物学发展开辞了一个新起点。许多研完Hl.h系 统的实验室竞相运用PCR技术,结合等位基因特异的 寡核昔酸（Allele-specific Oligonucleotide, ASO)或 顺序特异的寡核普胶(Sequence-specific Oligonucleotide, SSO)探针对HLA系统进行寡核昔酸分型,2_3 也有直接利用PCR扩增产物作RFLP分沂进行DNA 分型「'6,,"' + O DNA分型方法适用于任何有核细袍, 显示的结果与血清学或细胞学分型结果高度对应,而 且能够发现血清学或细抱学方法不能检测的额外特异 性,在理论上有助于进一步研究HLA系统基因的结构 和功能。对一些无法作常规分型的病例如裸露淋巴细 胞综合征、严重联合免疫缺乏症等,DNA分型叮解决 骨髓移植供受体配型问题‘哪’。     

关于人类白细胞抗原HLA

我们偶尔会在媒体上看到白血病患者或再生障碍性贫血患者进行骨髓移植后康复的好消息,但更多的却是由于缺少合适的骨髓而使生命之花凋零的坏消息。为什么合适的骨髓这么难找呢?这要从与骨髓移植密切相关的人类白细胞抗原HLA谈起。     

Evaluation of Serum and Tissue Levels of α-Tocopherol

This study was designed to test the effect of supplementation of several antioxidants, including α-tocopherol, on the clinical reduction of premalignant oral lesions. Samples of oral mucosa and serum were taken from baseline to 9 months of supplementation from patients with premalignant oral lesions and analyzed for α-tocopherol by HPLC. Statistical increases in both serum and tissue α-tocopherol were found after supplementation. There was no statistical relationship between α-tocopherol and β-carotene levels.     

Plant dehydrins — Tissue location, structure and function

Dehydrins (DHNs) are part of a large group of highly hydrophilic proteins known as LEA (Late Embryogenesis Abundant). They were originally identified as group II of the LEA proteins. The distinctive feature of all DHNs is a conserved, lysine-rich 15-amino acid domain, EKKGIMDKIKEKLPG, named the K-segment. It is usually present near the C-terminus. Other typical dehydrin features are: a track of Ser residues (the S-segment); a consensus motif, T/VDEYGNP (the Y-segment), located near the N-terminus; and less conserved regions, usually rich in polar amino acids (the Φ-segments). They do not display a well-defined secondary structure. The number and order of the Y-, S-and K-segments define different DHN sub-classes: Y_nSK_n, Y_nKn, SK_n, K_n and K_nS. Dehydrins are distributed in a wide range of organisms including the higher plants, algae, yeast and cyanobacteria. They accumulate late in embryogenesis, and in nearly all the vegetative tissues during normal growth conditions and in response to stress leading to cellular dehydration (e.g. drought, low temperature and salinity). DHNs are localized in different cell compartments, such as the cytosol, nucleus, mitochondria, vacuole, and the vicinity of the plasma membrane; however, they are primarily localized to the cytoplasm and nucleus. The precise function of dehydrins has not been established yet, but in vitro experiments revealed that some DHNs (YSK_n-type) bind to lipid vesicles that contain acidic phospholipids, and others (K_nS) were shown to bind metals and have the ability to scavenge hydroxyl radicals [Asghar, R. et al. Protoplasma 177 (1994) 87–94], protect lipid membranes against peroxidation or display cryoprotective activity towards freezing-sensitive enzymes. The SK_n-and K-type seem to be directly involved in cold acclimation processes. The main question arising from the in vitro findings is whether each DHN structural type could possess a specific function and tissue distribution. Much recent in vitro data clearly indicates that dehydrins belonging to different subclasses exhibit distinct functions. An erratum to this article is available at .     

HLA复合体与感染性疾病的关系

人类白细胞抗原（ＨＬＡ）是人类主要组织相容性复合体（ＭＨＣ）的基因产物,为目前已知的最复杂的人类基因复合体。由于ＭＨＣ分子在个体免疫调节中起主要作用,故其在控制个体对疾病的易感性方面也起重要作用。本文总结了近年来ＨＬＡ复合体与感染性疾病相关性的研究进展。     

肿瘤的HLA表达及其临床意义

HLA分子与肿瘤细胞的表达与肿瘤细胞的发生、发展有一定相关性。肿瘤细胞通过HLA分子表达的降低 ,抗原改变和细胞因子产生的变化对免疫调节产生一定影响 ,并与肿瘤的生长限制和切除的临床意义密切相关。