兔颞颌关节骨关节病模型的建立及组织学观察

（1）目的 研究强力霉素对颞颌关节骨关节病的预防性治疗作用。（2）方法 应用胶原酶注射法制备30例兔颞颌关节骨关节病模型。随机分为实验组和对照组两组,实验组动物在胶原酶注射的次日起每天给予口服强力霉素,在第4,8和12周末每组分别处死5只动物,分别在光镜下和电镜下观察关节盘和关节软骨的病理变化。（2）结果 在第4周末,对照组动物关节盘血管增生明显,软骨细胞增生活跃,实验组只表现为轻微的病变,在第8周末,对照组病变更为典型,出现软骨裂隙和凝胶样物质脱落,而实验组出现病变的修复;在第12周末,对照组出关节病的发展,促进关节的自身修复,对早、中期的颞颌关节骨关节病有显著的治疗作用。     

结构生物学在溶组织内阿米巴致病机制研究中的应用

溶组织内阿米巴（Entamoeba histolytica,Eh）是寄生于人类肠道的原生动物,可引起阿米巴性结肠炎和肠外脓肿。结构生物学在原子水平上研究生命大分子结构和功能,是一种重要的生物学研究方法,经过半个多世纪的理论和技术发展,已应用于生物学和基础医学的各个研究领域。本文综述了目前结构生物学的研究技术,并以阿米巴穿孔素A和半胱氨酸蛋白酶抑制剂为例介绍结构生物学在Eh致病机制研究中的应用,总结了今后结构生物学在Eh研究领域可能的应用方向和研究热点。     

A review of amoebic liver abscess for clinicians in a nonendemic setting

Amoebic liver abscess (ALA) is an uncommon but potentially life-threatening complication of infection with the protozoan parasite Entamoeba histolytica. E histolytica is widely distributed throughout the tropics and subtropics, causing up to 40 million infections annually. The parasite is transmitted via the fecal-oral route, and once it establishes itself in the colon, it has the propensity to invade the mucosa, leading to ulceration and colitis, and to disseminate to distant extraintestinal sites, the most common of which is the liver. The authors provide a topical review of ALA and summarize clinical data from a series of 29 patients with ALA presenting to seven hospitals in Toronto, Ontario, a nonendemic setting, over 30 years.     

溶组织内阿米巴半胱氨酸蛋白酶的纯化及其活性的初步研究

目的　探索溶组织内阿米巴通过基底膜进入固有膜的机制 ,了解其半胱氨酸蛋白酶 (cysteine pro-teinase,CP)与胞外基质的相互作用。　方法　阿米巴裂解液通过 laminin- Sepharose亲和层析和分离纯化 ,经分子量测定、测序及抑制剂实验 ,证明为 CP,以凝胶电泳测定其水解活性。　结果　纯化的 CP与 laminin有较强亲和力 ,其分子量为 2 7k Da,被 EC- 6 4所抑制 ,并具水解活性。　结论　溶组织内阿米巴半胱氨酸蛋白酶与胞外基质lam inin特异性结合 ,起水解作用 ,可能是入侵肠粘膜细胞基底膜的关键。     

Parasitological diagnosis combining an internally controlled real-time PCR assay for the detection of four protozoa in stool samples with a testing algorithm for microscopy

Molecular detection of gastrointestinal protozoa is more sensitive and more specific than microscopy but, to date, has not routinely replaced time-consuming microscopic analysis. Two internally controlled real-time PCR assays for the combined detection of Entamoeba histolytica , Giardia lamblia , Cryptosporidium spp. and Dientamoeba fragilis in single faecal samples were compared with Triple Faeces Test (TFT) microscopy results from 397 patient samples. Additionally, an algorithm for complete parasitological diagnosis was created. Real-time PCR revealed 152 (38.3%) positive cases, 18 of which were double infections: one (0.3%) sample was positive for E. histolytica , 44 (11.1%) samples were positive for G. lamblia , 122 (30.7%) samples were positive for D. fragilis , and three (0.8%) samples were positive for Cryptosporidium . TFT microscopy yielded 96 (24.2%) positive cases, including five double infections: one sample was positive for E. histolytica / Entamoeba dispar , 29 (7.3%) samples were positive for G. lamblia , 69 (17.4%) samples were positive for D. fragilis , and two (0.5%) samples were positive for Cryptosporidium hominis / Cryptosporidium parvum . Retrospective analysis of the clinical patient information of 2887 TFT sets showed that eosinophilia, elevated IgE levels, adoption and travelling to (sub)tropical areas are predisposing factors for infection with non-protozoal gastrointestinal parasites. The proposed diagnostic algorithm includes application of real-time PCR to all samples, with the addition of microscopy on an unpreserved faecal sample in cases of a predisposing factor, or a repeat request for parasitological examination. Application of real-time PCR improved the diagnostic yield by 18%. A single stool sample is sufficient for complete parasitological diagnosis when an algorithm based on clinical information is applied.     

Intestinal parasites including Cryptosporidium,Cyclospora, Giardia,and Microsporidia,Entamoeba histolytica,Strongyloides, Schistosomiasis,and Echinococcus: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of intestinal parasites in the pre‐ and post‐transplant period. Intestinal parasites are prevalent in the developing regions of the world. With increasing travel to and from endemic regions, changing immigration patterns, and the expansion of transplant medicine in developing countries, they are increasingly recognized as a source of morbidity and mortality in solid‐organ transplant recipients. Parasitic infections may be acquired from the donor allograft, from reactivation, or from de novo acquisition post‐transplantation. Gastrointestinal multiplex assays have been developed; some of the panels include testing for Cryptosporidium, Cyclospora, Entamoeba histolytica, and Giardia, and the performance is comparable to conventional methods. A polymerase chain reaction test, not yet widely available, has also been developed to detect Strongyloides in stool samples. New recommendations have been developed to minimize the risk of Strongyloides donor‐derived events. Deceased donors with epidemiological risk factors should be screened for Strongyloides and recipients treated if positive as soon as the results are available. New therapeutic agents and studies addressing the optimal treatment regimen for solid‐organ transplant recipients are unmet needs.     

Learning from the research on amebiasis and gut microbiome: Is stimulation by gut flora essential for effective neutrophil mediated protection from external pathogens?

Amebiasis, caused by intestinal infection with Entamoeba histolytica, is one of the leading causes of parasite infection-related mortality and morbidity globally. Although its pathogenesis, including determinant factors of infection outcome, remains unclear, recent clinical data indicate that the gut microbiome plays a role in determining the severity of amebiasis. Recently, we investigated the effects of the gut microbiome on neutrophil mediated protection from E. histolytica infection using a mouse model. We identified that surface expression of CXCR2 on neutrophils was diminished in mice with dysbiosis, which resulted in decreased neutrophil recruitment to the infection site, allowing more aggressive intestinal tissue damage by E. histolytica. Our results indicated that oxidase activity during E. histolytica infection was also diminished after dysbiosis, consistent with the results from prior research. Thus, the gut microbiome plays an important role in regulating neutrophil phenotype when fighting against external pathogens.     

Evidence for a link between locus R-R sequence type and outcome of infection with Entamoeba histolytica

The results of Entamoeba histolytica infections range from asymptomatic colonization to variable disease outcomes. However, markers that may predict infection outcomes are not known. Here, we investigated sequence types of a non-coding tRNA-linked locus R-R to identify surrogate markers that may show association with infection outcomes. Among 112 clinical samples-21 asymptomatic, 20 diarrhoea/dysentery and 71 liver abscesses-we identified 11 sequence types. Sequence type 5RR was mostly associated with asymptomatic samples, and sequence type 10RR was predominantly associated with the symptomatic (diarrhoea/dysentery and liver abscess) samples. This is the first report that identifies markers that may predict disease outcomes in E. histolytica infection.     

AIDS-ASSOCIATED PARASITIC DIARRHOEA

Since the advent of human immunodeficiency virus infection, with its profound and progressive effect on the cellular immune system, a group of human opportunistic pathogens has come into prominence. Opportunistic parasitic infection can cause severe morbidity and mortality. Because many of these infections are treatable, an early and accurate diagnosis is important. This can be accomplished by a variety of methods such as direct demonstration of parasites and by serological tests to detect antigen and/or specific antibodies. However, antibody response may be poor in these patients and therefore immunodiagnostic tests have to be interpreted with caution. Cryptosporidium parvum, Isospora belli, Cyclospora cayetanensis, Microsporidia, Entamoeba histolytica and Strongyloides stercoralis are the commonly detected parasites. Detection of these parasites will help in proper management of these patients because drugs are available for most of these parasitic infections.