Characterization of entamoeba histolytica antigens in circulating immune complexes in sera of patients with amoebiasis

Isolated circulating immune complexes (CICs) from sera of patients with amoebiasis were characterized to determine Entamoeba histolytica antigens that participate in the disease process. In total, 116 serum samples were collected before starting anti-amoebic therapy, and their CICs were isolated by differential polyethylene glycol precipitation. The presence of amoeba-specific antigens in CICs was detected by antigen capture enzyme-linked immunosorbent assay (ELISA) and by immunoblot assay. Antigen capture ELISA showed significantly higher optical density (p < 0.001) in all patients with amoebiasis than in the normal healthy controls and patients of non-amoebic hepatic disorder. Immunoblot assay detected amoeba-specific CICs in all 18 patients (100%) with confirmed amoebic liver abscess, 28 (80%) of 35 patients with clinically-suspected amoebic liver abscess, and 18 (78.26%) of 23 patients with amoebic colitis. No patients with non-amoebic hepatic disorders and healthy control subjects had any detectable level of amoebic antigens in CICs. Immunoblot assay revealed E. histolytica antigens of relative molecular masses of 35, 56, 70, and 90 kDa present in CICs of 64 of 76 patients with amoebiasis. The 35-kDa polypeptide was observed in 52 patients (81.25%). The results of the study suggest that the 35-kDa polypeptide antigen can be a diagnostic marker in active amoebiasis.

Efficacy and safety of oral iron chelating agent deferiprone in beta-thalassemia and hemoglobin E-beta thalassemia

OBJECTIVES

To assess efficacy and safety of oral iron chelating agent deferiprone (DFP) in patients with beta thalassemia and hemoglobin E-beta thalassemia.

DESIGN

Non-randomized study.

SETTING

Hematology Out-Patient Department.

SUBJECTS

Forty-one patients of beta thalassemia and hemoglobin E-beta thalassemia.

INTERVENTIONS

DFP was given to 20 patients, 10 patients of beta thalassemia and 10 with hemoglobin E-beta thalassemia; the rest were taken as controls.

RESULTS

A significant fall in serum ferritin was observed in the study group along with rise in urinary iron excretion (p < 0.05). Adverse effects of DFP were nausea and vomiting (30%), significant arthropathy requiring stopping of the drug (30%), and reversible neutropenia in one patient. All these complications could be managed easily with medical supervision and no death or permanent disability was seen.

CONCLUSIONS

DFP is an effective and fairly well tolerated oral iron chelating agent. The side effects that occur can be tackled easily if monitored properly.

Subpopulations of T lymphocytes in the peripheral blood, dermal lesions and lymph nodes of post kala-azar dermal leishmaniasis patients

Distribution of different subpopulations of T cells in the dermal lesions, lymph nodes and peripheral blood of post kala-azar dermal lesihmaniasis (PKADL) patients was studied by using appropriate phenotypic markers for CD2+, CD4+ and CD8+ cells. Histopathological studies of skin lesions showed marginal to massive infiltration of mononuclear cells depending upon the duration of illness and type of lesions. Thus, while the hypopigmented patches were represented by small focal collections of lymphocytes with scanty parasites in the dermis, these were replaced at the nodular stage with massive granulomas consisting of lymphocytes, plasma cells and histiocytes with numerous amastigotes. The involvement of CD4+ and CD8+ cell types in these lesions also showed a gradual change from the appearance of a few cells of both the phenotypes in early hypopigmented type to massive accumulation of cells, primarily of CD8+ phenotype, in the granuloma of nodular type. However, the observed preponderance of CD8+ cells at the lesion site of chronic PKADL patients is in contrast to their peripheral blood CD4+/CD8+ cell ratio (1.9:1) which remained within the normal limits. Similar studies of lymph nodes from PKADL patients with lymphadenopathy revealed infiltration of the cortical areas by T cells which were more of CD8+ than CD4+ phenotypes. All these results document the involvement of CD8+ cells in leishmanoid lesions. Thus, it is likely that these cells, in association with appropriate subpopulations of CD4+ cells, play a profound role in the evolution of dermal pathology in PKADL.

Detection of immune complexes in tissues of persons infected with Entamoeba histolytica

Immune complexes were detected by radioimmunoassay in colonic tissue from 71 to 122 patients (58%) excreting Entamoeba histolytica cysts and in liver tissue from 5 of 16 of these patients. Complexes were also found in colonic tissue from 9 of 56 other patients (16%) who were not excreting cysts.

Zymodeme alteration of Entamoeba histolytica isolates under varying conditions

Cysts of Entamoeba histolytica obtained from 2 asymptomatic subjects were cloned in vitro and the isoenzyme patterns and virulence of the cultures derived from them were determined. Incubation in Diamond's TYI-S-33 medium with Crithidia sp. for 80 d resulted in a change from zymodeme III to zymodeme II, with consistent virulence. Axenization by replacing Crithidia sp. with crithidial lysate had no further effect on the zymodeme but the virulence of the amoebae was attenuated. A reversal to zymodeme III, together with augmentation of virulence, was observed on the 20th day after transfer of axenic amoebae to Diamond's TYSGM-9 medium containing the original bacterial flora. The possibility that the isoenzyme pattern determining the zymodeme and the virulence behave as 2 independent variables in E. histolytica is discussed.

High cell surface hydrophobicity of virulent Entamoeba histolytica isolates

Thirty isolates of Entamoeba histolytica were examined for their cell surface hydrophobicity. It was observed that increased hydrophobicity of the trophozoites was associated with lesion-forming ability in hamster liver, a higher rate of erythrophagocytosis and greater resistance to complement. The relationship of cell surface hydrophobicity to other virulence markers in E. histolytica is discussed.

Enhancement of virulence of Entamoeba histolytica by in vitro liver treatment

Enhancement of the virulence of five strains of Entamoeba histolytica (three xenically maintained and two axenically maintained) was studied after in vitro incubation with normal hamster liver. Increased virulence was shown by the ability of a small number of liver-treated trophozoites to produce liver lesions in hamsters. Enhancement of virulence was positively correlated with increased resistance to normal hamster serum complement in vitro.

Study of Entamoeba histolytica isolates from Calcutta with special reference to their zymodeme, animal pathogenicity and erythrophagocytosis

Entamoeba histolytica isolates, obtained mainly from asymptomatic human cyst passers, were tested for their in vitro erythrophagocytic activity and lesion-forming ability in hamster liver. Simultaneous zymodeme typing of the isolates showed that, along with the pathogenic zymodemes, a number of isolates having nonpathogenic zymodemes also produced liver lesions in hamsters and engulfed higher numbers of RBCs. The observed positive correlation between the rate of erythrophagocytosis of an E. histolytica trophozoite and its degree of lesion-producing capacity in hamster liver suggest that the erythrophagocytosis assay in conjunction with the hamster liver inoculation test, can be useful in the identification of virulent E. histolytica isolates.

Experimental hepatic amoebiasis in inbred mice

A model of hepatic amoebiasis in two inbred strains of mouse (Swiss and BALB/c, has been developed by introducing Entamoeba histolytica-infected hamster liver tissue in between the adjacent liver lobes of mouse. It is expected that this model might be useful in studying various parameters of host-parasitic interactions and experimental chemotherapy of amoebiasis with relative ease.

Gastric carcinoma in a child associated with nodular lymphoid hyperplasia of the colon

We report a 12 year old boy of Nepalese origin with gastric adenocarcinoma and associated nodular lymphoid hyperplasia of the colon, with hemoglobin E trait and normal serum immunoglobulins. The boy underwent a curative resection and is free of recurrence or metastasis nine months after diagnosis.

The prediction of serum IgG levels by scanning densitometry

A novel approach has been described. In this method the serum IgG level can be predicted with a fair degree of accuracy by scanning densitometry and total serum protein values. This approach might be useful as a screening procedure for hypogammaglobulinemia.

Ultrasonographic evaluation of carcinoma of the gall bladder

Out of 6018 patients who were evaluated ultrasonographically for gastrointestinal problems over a four-and-a-half year period, 201 patients with a mean age of 53 years were diagnosed to have carcinoma of the gall bladder (3.3%). In 191 of these the diagnosis was confirmed by laparotomy and histopathological examination and in 3 other patients ultrasound guided fine needle aspiration cytology yielded malignant cells. In the remaining 7 patients the diagnosis was not confirmed by tissue examination-3 had metastases and 4 refused further investigation. Two sets of features were detected on ultrasonography: type I-a mass occupying the gall bladder fossa and obliterating the lumen (144 patients), and type 11-a polypoid lesion projecting into the gall bladder lumen (57 patients). Gallstones were present in 157 patients (78%) but more often in patients with the type I features. Associated ultrasonographic features such as liver and lymph node involvement, dilatation of intrahepatic bile ducts and ascites were also assessed. We conclude that abdominal realtime ultrasonography is a reliable method for diagnosing carcinoma of the gall bladder.

A model of hepatic amoebiasis in random bred mice

This study describes a model of hepatic amoebiasis in random bred mice (MF2). Mice were infected by introducing liver tissue from hamsters (Mesocricetus auratus), containing about 5 X 10(4) trophozoites of Entamoeba histolytica, between adjacent liver lobes. Direct inoculation of xenic E. histolytica resulted in mortality within 24 h, whereas monoxenic and axenic strains failed to produce any lesions. Serial mouse liver passage resulted in increased lesion score, number of metastatic abscesses, and mortality. Metronidazole 150 mg/kg produced complete healing of the abscess. It is expected that this model will be useful to study host-parasite interactions, immunology and experimental chemotherapy of amoebiasis.

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 (greater than 1:2048 by 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.

Slow-release potassium and perforation of Meckel's diverticulum

A case of peritonitis following perforation of gastric-type mucosa in a Meckel's diverticulum is described. At laparotomy a wax core of a combined diuretic-slow-release potassium preparation was found extruding through the perforation and a further pellet was found free in the peritoneal cavity. Intestinal perforation due to potassium-containing drugs is recognized and led to the development of enteric-coated and slow-release delivery systems. The association of perforation of Meckel's diverticulum with a slow-release potassium perforation has not previously been described.

A simple ELISA for antigiardial antibody using the membrane fraction of the parasite as antigen

Most existing methods for detecting antigiardia lamblia antibody require the use of cultured Giardia lamblia trophozoites as antigen in immunofluorescent and enzyme-linked immunosorbent assays. However, the maintenance of trophozoite culture systems limits the large-scale use of these antibody detection systems. An antigen extracted from Giardia lamblia by the detergent Triton X-100, when used in an ELISA system, produces specific, objective, quantitative and reproducible results. It is likely that such a test system could be packaged in kit form for large-scale diagnostic and epidemiological application in all parts of the world.

Significance of carcinoembryonic antigen in retinoblastoma

The role of estimating the serum carcinoembryonic antigen (CEA) in the diagnosis and prognosis of retinoblastoma cases has been evaluated. Although the mean serum CEA titre in children with retinoblastoma was higher than that in control children (p = 0.01), the serum CEA level itself was found not to be a useful marker in the diagnosis of retinoblastoma. A significant correlation of serum CEA titre with progression or regression of the disease observed during therapy in most cases indicated that serial assays of serum CEA may be important in the follow-up of cases with retinoblastoma. The lower CEA values in aqueous humour and subretinal fluid from eyes with retinoblastoma than in the serum suggests that the tumour does not secrete the CEA.

Lactate dehydrogenase level and protein pattern in the aqueous humour of patients with retinoblastoma

The diagnostic significance of the lactate dehydrogenase (LDH) level and the protein pattern in the aqueous humour was evaluated in patients with retinoblastoma who presented with leukokoria. The mean LDH level for the 14 retinoblastoma patients was significantly greater than the mean for 6 patients with leukokoria but without retinoblastoma (p less than 0.05) and the mean for 10 patients (controls) with senile cataract (p less than 0.01). Cellulose acetate membrane electrophoresis was performed on the aqueous humour of six of the patients with retinoblastoma, four of the patients with other causes of leukokoria and eight of the control patients. It showed that the protein in the aqueous humour was predominantly albumin in the patients with retinoblastoma; the globulin in these cases was usually beta-globulin. The protein was mostly or completely albumin in the three patients with Coats' disease, and the protein pattern simulated that in normal serum (owing to hemorrhage) in the patient with retinal detachment. No protein was detectable in the aqueous humour of the control patients. Thus, determining either the LDH level or the protein pattern in the aqueous humour can serve as a useful adjunct to the clinical diagnosis of retinoblastoma.

Small intestinal nodular lymphoid hyperplasia in patients with giardiasis and normal serum immunoglobulins

Nodular lymphoid hyperplasia of the upper small intestine was demonstrated in 25 patients with giardiasis. All had normal serum immunoglobulin levels and seven patients initially presented with clinical findings suggestive of an abdominal lymphoma. In only two, however, was the diagnosis of primary jejunal lymphoma confirmed. It is possible that an aetiological relationship exists between recurrent parasitic infestation and nodular lymphoid hyperplasia of the upper small intestine.

Extradural spinal meningioma arising from a nerve root: case report

✓ A case is reported of spinal compression due to an extradural meningioma arising exclusively from the nerve root.

Gastric acid secretion rate and buffer content of the stomach after a rice- and a wheat-based meal in normal subjects and patients with duodenal ulcer

The study describes gastric acid secretory response to a rice-based and a wheat-based meal over a prolonged period of five hours and buffer content of the stomach in five normal and seven duodenal ulcer subjects from the rice-eating eastern Indian population. The results suggest that (1) the meal-mediated gastric acid secretory response in duodenal ulcer subjects is much higher than in the controls, even though the histamine stimulated response is similar, (2) the type of meal, whether rice and fish based or wheat and meat based, does not influence the acid secretory response, and (3) the duodenal ulcer subjects in this area, two hours after a meal, have a buffer capacity similar to the controls.

Histamine and insulin dose-response studies of gastric secretion in Indian control subjects and patients with duodenal ulcer in the Ganges delta

The gastric secretory responses to various doses of histamine and insulin have been studied in 11 control and 12 duodenal ulcer subjects belonging to the Ganges delta of India where the incidence of duodenal ulcer disease is known to be high. A dose of 0.04 mg/kg body weight of histamine acid phosphate was sufficient to produce peak gastric acid output both in the control and duodenal ulcer subjects. However, a dose as low as 0.025 U insulin/kg body weight was enough to produce peak rates of gastric acid output in duodenal ulcer subjects, whereas in the controls a minimum dose of 0.05 U insulin/kg body weight was sufficient. A greater proportion of the duodenal ulcer patients also showed a peak acid secretory response in the first hour after administration of insulin. Furthermore, increasing doses of insulin in this population did not produce lower levels of blood glucose but did produce increasingly high acid output as subjects do in the West. K values derived from the intravenous glucose tolerance test showed that 75% of duodenal ulcer patients and 54% of the controls had variable degrees of intolerance to glucose. Gastric acid secretion in response to a bolus of 50 ml 50% intravenous glucose was also studied in a separate group of 16 duodenal ulcer and 13 control subjects. A sharp rise in the volume, titratable acidity, and total acid output was observed in the early part of the fourth hour in the control and duodenal ulcer subjects. In a separate group of controls a bolus of intravenous hypertonic saline produced no such increase in gastric acid secretion.

Oral rehydration in infantile diarrhoea. Controlled trial of a low sodium glucose electrolyte solution

The paper describes the first controlled trial of an oral glucose electrolyte solution designed on the basis of the optimum pathophysiological needs for rehydration in infantile diarrahoea. The solution, having a sodium concentration of 50 mmol/l, was tried in a group of 20 infants with moderate to severe dehydration due to acute diarrhoea and was compared with a matched group of 19 infants predominantly under 2 years of age taking a 'standard' oral solution with a sodium concentration of 90 mmol/l. They could be hydrated as well with a low sodium oral solution alone as with the standard solution. Intravenous fluid was not required in either group. The group treated with the high soldium 'standard' solution appeared to develop hypernatraemia and/or periorbital oedema more frequently than the other group. Also, the low sodium solution eliminated the need for additional free water orally.

Evaluation of a sucrose/electrolyte solution for oral rehydration in acute infantile diarrhoea

An oral sucrose/electrolyte solution brought about complete hydration in 19 out of 20 consecutive children with a median age of 1 year with moderate to severe dehydration due to acute diarrhoea (1 child did not respond and needed intravenous therapy). Vomiting, abdominal distension, and appearance of sugar in the stools during oral hydration did not interfere with its success. A satisfactory response was shown by weight gain (mean +/- S.E. = 9-2 +/- 0-6%), restoration of plasma-bicarbonate to normal levels, falls in the haematocrit values and in the plasma specific gravity, and complete clinical recovery. Disaccharidases in jejunal mucosal biopsy specimens in the acute phase showed reduced lactase in 75% and reduced sucrase in 18%; maltase levels were adequate. Except for the child who did not respond, all showed a satisfactory rise of blood-sugar after sucrose and glucose tolerance tests. Sucrose is cheap and easily obtained; its use instead of glucose in electrolyte solutions would be a considerable gain.

Vitamin A absorption in ascariasis

Vitamin A absorption was studied in a group of 28 adult patients with ascariasis and 12 healthy adult controls, using a simplified vitamin A absorption test. In over 70% of the patients with ascariasis malabsorption of vitamin A was demonstrated. Stool egg counts for ascaris were not related to the degree of vitamin A malabsorption. Of the 23 patients in whom a D-xylose absorption test was performed, seven showed excretion less than 20% in 5 hr. Immediately after expulsion of the worms, vitamin A absorption improved in 13 out of 14 patients tested (in nine to normal level). The results of this study suggest that ascariasis in populations on marginal intakes of vitamin A and its precursors is an important contributing factor in producing clinical vitamin A deficiency.