Amoebic Disease Research Articles

アメーバ症の血清学的診断法に関する基礎的研究

We studied the establishment of enzyme-linked immunosorbent assay (ELISA) using amoebic antigen for complement fixation (CF) test. Optimal dilution for ELISA of sera from patients was 1:100, and that of CF-antigen was 1:400. The upper limit of the 99% critical range of the reaction of negative sera was 0.068 (cut-off level). Absorbance of sera from patients diluted 1:100 to antigen and antibody titers of ELISA were strongly correlated, so it was possible to estimate antibody titers from absorbance of serum diluted 1:100. ELISA and CF test were done to compare sensitivity of the tests using 63 sera from patients with invasive amoebic disease. The sensitivity of ELISA compared well with CF test (62 sera were positive by ELISA and 61 by CF test). Only one sample was both positive by ELISA and negative by CF test. This sample had low ELISA titers, so this discrepancy was mainly due to the sensitivity of CF test in detecting lower levels of antibody. These results suggested that the amoebic antigen for CF test can be applicable to ELISA, and this method was so sensitive and specific.

Kinetics of the immune responses during the course of hepatic amoebic infection—an experimental study

Following intrahepatic inoculation of axenic Entamoeba histolytica (strain NIH:200V), all hamsters developed amoebic abscesses in the liver by 7 d after inoculation. All the animals cleared the infection spontaneously by 28 d after inoculation. The establishment of amoebae leading to acute liver abscess was accompanied by significantly reduced levels of antibodies to the plasma membrane (PM) protein of E. histolytica, reduced direct macrophage cytotoxicity, and reduced anti-PM antibody-mediated macrophage-dependent cytotoxicity to amoebic trophozoites. This phase of infection was also accompanied by a significant reduction in cellular sensitization to PM proteins and to phytohaemagglutinin. Reduction in size of the liver abscesses and clearance of infection were accompanied by significant development of anti-PM antibodies, cellular sensitization to the PM proteins, enhanced direct macrophage cytotoxicity, and anti-PM antibody-mediated macrophage-dependent cytotoxicity to trophozoites. The data suggest that the amoebic disease process is modulated by immune responses to the PM protein of E. histolytica.

A specific solid-phase assay for the detection of immune complexes containing Entamoeba histolytica antigens

An assay specific for immune complexes containing Entamoeba histolytica antigens has been developed. Rabbit antibody specific for human gamma globulin is attached to a solid phase (nitrocellulose). During the first incubation step polyethylene glycol-precipitated immune complexes are bound to the rabbit antibody attached to the solid phase. In the second incubation step a radiolabelled rabbit antibody specific for Entamoeba histolytica combines with E. histolytica antigens in the complexes. Quantitation of the radiolabel provides a direct measurement of the level of specific immune complexes. The principle of the method has been verified using artificial soluble immune complexes prepared by mixing a pool of serum containing a high titre of anti- E. histolytica antibodies (> 1 : 2048 by indirect hemagglutination assay) with the E. histolytica antigen. This antigen was prepared from axenically cultured NIH : 200 strains of Entamoeba histolytica. Using sera from patients with clinical amoebic disease this method detected immune complexes containing E. histolytica in a high proportion of cases.

Amoebic disease precipitated by corticosteroids prescribed for tuberculous pleural effusions

One case of ameobic abscess of the liver and one case of amoebic dysentery are described in two patients who were prescribed corticosteroids as part of the intreatment for tuberculous pleural effusion. In both cases routine stool examinations prior to steroid therapy were negative for cysts or trophozoites of E. histolytica.

Atlas of Practical Proctology

Neiger has gathered together an atlas containing many photomicrographs and diagrams of perianal and rectal diseases. Considerable space is given to the commonest disease of this part of the anatomy, hemorrhoids. Methods of treatment are described, including medical (sclerosing agents, rubberband ligature) and surgical removal. Also presented are photomicrographs of perianal fissures, fistulae, perianal abscess, and rectal prolapse. Examples of benign neoplasms are shown, including perianal condylomata, lipomas, fibromas and hypertrophied papillas. Also illustrated are examples of anal carcinoma and malignant melanoma. No histologic representation of neoplastic lesions is shown. Five photomicrographs are shown of the mucosal changes seen in ulcerative colitis, together with one each of the mucosal changes seen in Crohn disease of the colon (rectum) and amoebic dysentery. Therapy for these diseases is briefly touched on and greatly over simplified. For example, current accepted front line drug therapy of both intraluminal and extra intestinal amoebic disease is

Cellular sensitivity in amoebiasis—preliminary results of lymphocytic transformation in response to specific antigen and to mitogen in carrier and disease states

The essential problem in amoebiasis is to determine the factors that initiate, and subsequently influence, the invasion by lumen-dwelling Entamoeba histolytica of the mucosa of the bowel. A large number of contributory causes have been described, including intestinal flora, diet, “stress” and immunity, parasite strain, and the overall environment influencing the rate of transmission and the level of challenge (ELSDON-DEW, 1968; KNIGHT, 1975); the broad range of these influences is reflected in the equally broad range of clinical symptoms and disease. Studies on the host’s immune response in amoebiasis have centred largely on responses in clinical disease and a wide range of antibodies have been described in both intestinal and extra-intestinal amoebic disease (MADDISON, KAGAN and NORMAN, 1968; KRUPP, 1970). Studies of cellular sensitivity in man appear to be limited to two reports on the sensitivity of lymphocytes from patients with liver abscess to amoebic antigen and mitogens in macroculture (SAVANAT, VIRIYANOND and NIMITMONGKOL, 1973; ORTIZ-ORTIZ, ZAMACONA-RAVELO and CAPIN, 1974). Twenty-one of 23 patients showed positive transformation, the cells producing between 31% and 23 % of the response stimulated by phytohaemagglutinin (PHA). No correlation was detected between degree of blast transformation and humoral antibody response. Whatever factors control the ability to invade, the success of the aggressive parasite will depend on overcoming the response of the host. Therefore, an examination of immune parameters at all stages of amoebiasis may yield important information on why E. histoZytica does or does not successfully invade. This paper reports the results of preliminary investigations into the cellular sensitivity of subjects drawn from an area where amoebiasis is highly endemic (HARRIS and BRAY, unpublished data), and selected for a range of disease situations from negative controls through symptomless carriers to acute disease.

The preparation of amoebic extracts and their testing by complement fixation against clinically proved sera

1. 1. A complement fixation technique for 60°C.-inactivated sera, suited to the diagnosis of amoebic disease, is described. 2. 2. The preparation of tungstate-precipitated antigen is described. This antigen is stable to autoclaving. 3. 3. Axenically produced antigen gives similar results but is less anti-complementary and therefore better to work with. It is unstable at −15°C. after rehydration. 4. 4. Antigenicity has been shown as a property of E. histolytica only. Negative CFT results with E. histolytica antisera from patients were obtained using extracts of E. hartmanni, E. coli, D. fragilis, E. nana, E. invadens, E. ranarum, E. moshkovskii and the Huff strain; while immune rabbit sera, prepared by injecting these extracts, as well as by injecting blank (amoeba-free) extracts, reacted heterologously in the CFT with all extracts. 5. 5. Negative results were obtained in the CFT with E. histolytica antigen, using sera from carriers of E. histolytica, E. hartmanni, E. coli, D. fragilis, E. nana, I. bütschlii and also using sera from selected groups of non-amoebic disease. 6. 6. Antigenicity of extracts was found to be associated with altered serum protein (ASP), and this was thought to be due to entanglement in ASP of amoebic fragments. 7. 7. Antigenic evidence has been obtained which supports (a) the separation of E. hartmanni, E. moshkovskii and the Huff strain from E. histolytica; (b) the non-existence of “small race” and “minuta” forms; (c) the identification of transiently “polecki” forms with E. histolytica; and (d) the equal antigenicity of pathogenic and carried strains of E. histolytica. 8. 8. The selected sera remaining from this work have been banked at −20°C. at the London School of Hygiene and Tropical Medicine, whence they are available to others.

Oral dehydroemetine dihydrochloride in intestinal and hepatic amoebic disease

105 patients with acute intestinal amoebiasis, 35 with chronic intestinal disease and 42 with acute hepatic amoebiasis were treated with late-release oral DHE (Ro 1-9334/9 25 mg. and 9334/19 10 mg.). Cure rates of 86% for the acute intestinal form, 34% for the chronic cyst passers with diverse gastro-intestinal disturbances and 100% for acute hepatic amoebiasis were obtained on a total dosage of 1–3 grammes according to age, weight, etc. These results agree with results obtained by various authorities in Europe, Africa and India, but not in South Africa. Oral DHE was found useful both as a tissue and contact amoebicide. It is much less toxic and more active than emetine and can be given in larger doses and for longer periods with safety. Owing to the quick excretion, repeat courses can be given at short intervals, as necessary, without danger. Toxicity of the drug orally and parenterally was studied clinically, biochemically, and electrocardiographically in detail by Dempsey and Salem (1966 ) and with larger doses than used in the present study. No serious side effects were noted particularly with the oral form and it was far better tolerated by children, who received relatively higher dosage than most adults. The only contra-indication is for patients with manifest decompensation of vital organs, or fevers.

Dysentery bacilli-Shigella; a brief historical review.

This is a brief history of the bacteriology of bacillary dysentery from the time of its differentiation from the amoebic disease up to the present time. It is meant to be a story of events rather than a critical essay. A certain amount of background has been introduced to indicate the problems of identification and classification of the various bacterial types of the disease. Inevitably more space has been given to the mannite-fermenting organisms since the problem of their antigenic structure and interrelationship took so many years to solve. The events leading up to the present serological classification of the dysentery bacilli are set out and certain other problems e.g., those related to the carriage of Shigella antigens by other members of the Enterobacteriaceae are discussed.

Amoebic Disease in a Group of College Students

Amoebic Disease in a Group of College Students

Amoebic Disease in a Group of College Students

Amoebic Disease in a Group of College Students

An autopsy in acute bacillary dysentery: (With a note contrasting the pathological appearances with those seen, in amoebic disease.)

An autopsy in acute bacillary dysentery: (With a note contrasting the pathological appearances with those seen, in amoebic disease.)