实验性肝阿米巴病的组织化学和超微结构观察

应用肝内接种法建立实验性肝阿米巴病金黄仓鼠模型,以组织化学和透射电镜技术,结合观察仓鼠肝阿米巴病的肝组织中糖原、蛋白质、核酸、胶原和网状纤维以及超微结构的变化,探讨了溶组织内阿米巴的致病机理。     

用微量不透明硫酸钡造影法示阿米巴肝脓肿消退时间

通常所知肝阿米巴病是指阿米巴肝脓肿。过去用水或油类溶性染料造影剂主要描述肝脓肿的轮廓而不是检验它的消退时间。这二种物质能延缓肝脓肿的治愈。扫描、肝血管造影等技术虽可显示占位性病变外形,但该技术用费昂贵,操作不便。本文介绍一种显示肝脓肿消退的简单方法--微量不透明硫酸钡腔内造影法。     

影响溶组织内阿米巴致病力的生物因素

溶组织内阿米巴的致病作用受多种因素影响。生物因素通过对阿米巴毒力、致病性以及宿主的机能状态、免疫调节等方面的作用,影响阿米巴病的发生与发展。无菌培养的阿米巴在仓鼠肝内不产生肝脓肿,在豚鼠盲肠内也不发生侵袭性病变,阿米巴只有和细菌相互作用后,才有明显的致病性和使宿主发生肝脓肿的能力。细菌可提供适宜的理化、营养条件和附加体样致病因子,以及在消除毒性分子、加强酶的功能、促进与阿米巴的粘附等方面起作用。迄今已在阿米巴内区分出三种病毒。病毒在核内大量复制,形成微丝,导致核溶解、阿米巴死亡。病毒基因还可整合到阿米巴的DNA上。阿米巴似可作为甲肝病毒的传播媒介。艾滋病患者合并的阿米巴病病变往往更为严重。霉菌寄生于阿米巴内,显示对核的破坏作用;阿米巴病合并念珠菌和放线菌感染时,病变加剧。和弓形体一起培养的阿米巴,对肠上皮细胞损害力增强。感染了血吸虫、粪类圆线虫、鞭虫等的患者,肠道常发生急性炎症反应,致使肠上皮细胞变性、渗出、坏死,局部抗溶组织内阿米巴感染的能力降低,促进阿米巴的入侵。另外,蠕虫感染后,宿主全身免疫功能减退,白蛋白下降、贫血以及巨噬细胞活力受抑,也有利于阿米巴病的发生与发展。     

妊娠及分娩期的阿米巴病

作者复习了近十年来有关妊娠及分娩期阿米巴病的临床及病理资料,并对坦桑尼亚乞力马扎罗区医学中心1971～1976年的20,000例分娩期中合并阿米巴病而死亡的8例,作了分析。因阿米巴病死亡的共98例,内男性55例,女性43例。其中阿米巴结肠炎及阿米巴肝脓疡的发病数,男女分别为40及37和15及6例。因妊娠期并发阿米巴病     

间接荧光抗体试验和酶联免疫吸附试验在孟加拉国诊断肝阿米巴病的评价

由溶组织内阿米巴引起的阿米巴病每年引起11万人死亡,其中肝阿米巴病(HA)是侵袭性阿米巴病中引起死亡最常见的原因。孟加拉国是肠阿米巴病的流行国家,但没有关于肠外阿米巴病的详细资料。至今,HA的诊断仍然靠病史、临床发现以及肝脓肿的物理特征;偶尔也检查粪便和脓液里的溶组织内阿米巴,两者都不是太敏感的方法。血     

实验性大鼠肠阿米巴病的病理学研究——扫描电镜及免疫组织化学观察

用盲肠内接种阿米巴滋养体的方法,复制出大鼠肠阿米巴病动物模型,经组织学及扫描电镜观察发现:感染大鼠的盲肠病变与人类急慢性肠阿米巴病类似,早期为盲肠的弥漫性、非特异性炎症及溃疡形成,晚期为修复愈合与新鲜溃疡同时存在的组织学改变,病变出现高峰在接种后3～7d 间;大鼠感染率为93.6%,盲肠溃疡发生率为43.6%,可作为研究肠阿米巴病的动物模型。应用自行制备的兔抗阿米巴血清对感染的盲肠组织进行免疫组织化学(PAP)染色的结果,证实此法能清楚、准确地显示组织中的阿米巴滋养体,可用于肠阿米巴病的病理诊断及回顾性研究。     

甲硝磺酰咪唑和甲硝咪唑治疗肝阿米巴病效果的比较

甲硝咪唑治疗阿米巴病的效果好而副作用少,促使对治疗阿米巴病的硝基咪唑类药物的进一步研究。甲硝磺酰咪唑是硝基咪唑类的一个衍生物,其化学式为乙基2-(甲基-5硝基-1-咪唑乙基)砜。实验和临床均证明它也具有抗溶组织内阿米巴的作用。本文对这两药治疗肝阿米巴病的效果进行了观察和比较。选择31例经临床、放射学和实验室确诊的肝阿米巴病患者为治疗对象。全部患者均无因肝脓肿破裂引起的严重并发症,在2周前也未服过其他抗阿米巴药。将31例患者随机分为2组:甲硝咪唑组15例(男11例、女     

可的松治疗肝阿米巴病的危险

最近,作者观察到肝阿米巴病的发病率达1.9％,而Morcos(1958)报告在200例阿米巴痢疾患者中有1％患阿米巴肝炎。埃及肝阿米巴病发生率的升高,可能是广泛用可的松治疗的结果。本文的目的在于解释可的松治疗与肝阿米巴病的关系。     

慢性HBV携带者病毒抗原表达类型与抗病毒治疗效果相关性研究

目的观察肝脏病理改变和肝细胞内病毒抗原的表达类型与抗病毒治疗疗效的关系。方法选择79例慢性HBV携带者,通过肝组织病理检测,观察肝脏病理改变程度、肝细胞内病毒抗原的表达类型和抗病毒治疗后血清HBeAg、HBVDNA转阴之间的关系。结果HBsAg表达类型与疗效无显著相关性,HBcAg浆型表达的疗效明显优于核型表达,肝组织病理病变大于4分,血清HBV标志物阴转率高。结论肝组织HBcAg浆型表达和肝组织病理改变与慢性HBV携带者抗病毒治疗疗效均呈正相关。     

肺—胸膜阿米巴病

肺——胸膜阿米巴病虽属少見,但在阿米巴病的并发症中,除肝脏占第一位外,肺——胸膜占第二位。本病常继发于肝阿米巴病,作为肝阿米巴病的并发症来看約占7.5-33.3％。梁氏等报告肝阿米巴病114例中并发本病者32例,占28.1％,孟宪鏽等之239例中有64例(包括反应性胸膜炎5例),占26.8％。我院近14年(1950年1月至1963年8月)来共收治确診肝阿米巴病108例,其中并发肺——胸膜阿米巴病者20例,占18.5％。Roger报告81例右叶阿米巴肝脓瘍之尸检材料中,32％并发肺脓瘍;Abdel-Shafi报告之阿米巴病尸检材料中,胸部之并发症高达60％。因此本病之真正发病率較临床上所观察到的要高,故应提高警惕。     

Amebic Liver Abscess

We present a patient with an acute amebic liver abscess with nonreactive serologic tests. Motile hematophagous trophozoites of Entamoeba histolytica were seen microscopically in scrapings from the wall of the abscess. Postoperative serologies revealed rapidly rising then falling titers by SAFA and IHA antibody assays. Serologic tests for amebiasis may be reative in greater than 95% of patients with invasive amebiasis. Nevertheless, a reactive serologic test should not be relied upon exclusively to establish the diagnosis. Sequential serologic testing and surgical intervention to obtain material for microscopic examination, gram stain and bacteriologic culture are warranted in patients with hepatic abscess and nonreactive serologic tests for antibodies to E. histolytica.     

Hepatic amebiasis: study of 152 cases

The purpose of this study was to describe and analyse retrospectively the clinical, serological, anatomical and evolutive features of 152 cases of hepatic amebiasis in young adults, treated and followed up in France from 1969 to 1983. The disease was revealed 3 times out of 4 by tender hepatomegaly with fever, but only in 6 cases by complications. Serological tests (immunofluorescence or hemagglutination) were always positive for amebiasis, whereas Entamoeba histolytica was absent from stools in 96.7 p. 100 of the cases. Hepatic amebiasis always caused a hepatic abscess: in these cases, the superiority of ultrasonography over all other diagnostic methods was confirmed, especially concerning the detection of multiple abscesses (47 p. 100). Complete recovery was obtained by medical treatment in 117 cases, either alone (98 cases), or combined with needle aspiration (19 cases). Nitro-imidazoles are the simplest treatment, but nevertheless in 5 cases they were not effective. These patients were then treated with dehydroemetine, associated in 2 cases with surgery. Four patients relapsed at mid or long-term after apparent recovery, in the absence of any obvious reinfection. A significant correlation between the course of the treated disease and the size and number of abscesses was demonstrated: it was possible to define a group characterized by a slow and/or complicated course (with single abscess of the right lobe whose diameter is equal to or greater than 10 cm, or multiple abscesses). The pathogenesis of hepatic amebiasis is not yet fully understood.     

Varioliform mucosal polypoid lesions in intestinal tract in a patient with adult T-cell leukemia

We describe a case of adult T-cell leukemia (ATL) with intestinal infiltration. In the early clinical stage, the endoscopic findings for the intestine were similar to those of amebic enterocolitis, i.e., varioliform mucosal polypoid lesions, and amebic cyst was detected with stool examination. Although no specific pathological factor could be identified on biopsy, the patient was treated for amebiasis as a diagnostic therapy. the findings of varioliform mucosal polypoid lesions were detected in the duodenum on endoscopic examination, but the lesions eventually disappeared during the treatment for amebiasis. We then suspected lymphoma partially masked by, the amebiasis. Immunological staining of a specimen of the colonic mucosa revealed T cell invasion and Southern blotting demonstrated adult T-cell leukemia provirus invasion. Thus, ATL cell infiltration of the intestinal tract was confirmed It is suggested that systemic disease should also be considered when varioliform mucosal polypoid lesions are found on colonoscopic examination.     

Fulminant hepatic failure secondary to amebic abscesses

Summary A patient presented with fulminant hepatic failure which rapidly led to his death. At postmortem examination, he had several amebic abscesses secondarily infected with bacteria, one of which had ruptured intraperitoneally, and another of which had occluded major hepatic veins of the right lobe of the liver. In addition, pylephlebitis and occlusion of several right portal venous radicies were noted. Microscopic examination of the right lobe revealed marked sinusoidal congestion and large areas of infarction with severe panlobular necrosis. Fuiminant hepatic failure secondary to complications of amebic abscess has been reported infrequently but should be considered in patients with this presentation who have visited or inhabited areas endemic for amebiasis.     

Mechanism of tissue damage through free oxygen radicals during hepatic amoebiasis in guinea pigs

The capacity of Kupffer cells and blood monocytes to release free oxygen radicals was studied by chemiluminescence (CL) response during hepatic amebiasis in guinea pigs. Guinea pigs infected with Entamoeba histolytica intramesenterically were sacrificed on days 0, 2, 5 and 8 post-infection. Hepatic lesions were graded I-IV. A significant increase in the CL response was observed from day 2 post-infection and it increased with the progress of infection. Maximum increase was observed on the 8th post infection day. Animals with grade III or IV hepatic lesions had significantly elevated CL response. The degree of hepatic lesions correlated well with the CL response (P less than 0.01). It is postulated that tissue damage during hepatic amoebiasis may be mediated through enhanced release of free oxygen radicals by Kupffer cells and blood monocyte.     

Papers from Abroad

The capacity of Kupffer cells and blood monocytes to release free oxygen radicals was studied by chemiluminescence (CL) response during hepatic amebiasis in guinea pigs. Gunea pigs infected withEntamoeba histolytica intramesenterically were sacrificed on days 0,2,5 and 8 post-infection. Hepatic lesions were graded I–IV. A significant increase in the CL response was observed from day 2 post-infection and it increased with the progress of infection. Maximum increase was observed on the 8th post infection day. Animals with grade III or IV hepatic lesions had significantly elevated CL response. The degree of hepatic lesions correlated well with the CL response (P<0.01). It is postulated that tissue damage during hepatic amoebiasis may be mediated through enhanced release of free exygen radicals by Kupffer cells and blood monocyte.     

Rapid diagnostic approach to amebic liver abscess

Summary A Viet Nam veteran was found to have a large liver abscess, almost certainly due toE. histolytica, although the organism was not recovered. A prompt diagnosis was made within 5 days of admission to the hospital, and thus proper chemotherapy and needle aspiration of the abscess were accomplished without undue delay. Confirmation of the clinical suspicion of amebiasis of the liver was achieved by a positive serologic test for amebiasis, and a large defect in the right lobe of the liver shown on radioisotope liver scan.     

Amebiasis in Japanese homosexual men with human immunodeficiency virus infection

We report cases of amebiasis in 6 human immunodeficiency virus (HIV)-positive male patients. Five were confirmed homosexuals while one was suspected. Three patients had liver abscess and 5 had colitis with duration of 10 days to months. The patients with liver abscess showed a lower incidence of abdominal pain but a higher incidence of concomitant diarrhea. Drainage therapy was effective for rapid afebrile results. Two invasive colitis cases died from perforation. This may have been due to delayed diagnosis. Invasive amebiasis is not common even in HIV-infected individuals. Among Japanese homosexual men, however, it may cause symptomatic diseases.     

Experience with intravenous metronidazole to treat moderate-to-severe amebiasis in Japan

Twenty-eight cases of either intestinal amebiasis, amebic liver abscess, or both, most of which were of moderate-to-severe intensity, were treated with intravenous metronidazole, pioneered by the Research Group on Chemotherapy of Tropical Diseases, Japan. This study was not conducted as a formal clinical trial, and all patients either underwent colectomy for intestinal amebiasis, received oral metronidazole, or both. Despite these limitations, intravenous metronidazole was shown to be well tolerated and seemed to be very effective. This agent should be more widely recommended than previously thought for treating moderate-to-severe amebiasis, especially its intestinal form.     

Correlation of positive syphilis serology with invasive amebiasis in Japan

Approximately 20% of 52 Japanese males with invasive amebiasis confirmed by gel diffusion precipitin test (GDP) were positive by both Treponema pallidum hemagglutination test (TPHA) and nontreponemal antigen tests, and an additional 20% were positive by TPHA alone. However, none of 109 GDP-negative Japanese males without invasive amebiasis were positive on these serologic tests for syphilis. At least 2 bisexuals and 4 homosexuals were among those with invasive amebiasis. All of these biased males were positive on both TPHA and nontreponemal antigen tests. Four of the biased males had liver abscess and 2 had amebic dysentery or colitis. Bisexual or homosexual males were not found in the negative GDP group. These observations suggest that sexually transmitted amebiasis due to Entamoeba histolytica occurs among sexually biased males in Japan.