Comparação entre praziquantel e oxamniquine no tratamento da esquistossomose mansoni

Tratamos 120 pacientes masculinos com idade de 17 a 19 anos, portadores de esquistossomose mansoni nas formas intestinal e hepatointestinal, pareados de acordo com o número de ovos por grama de fezes. Um membro de cada par tomou oxamniquine na dose de 15mg/kg e o outro, praziquantel na dose de 55mg/kg, em cápsulas. Dos 106 pacientes avaliados com pelo menos dois exames de fezes, negativaram-se 44 (83%) dos que tomaram praziquantel e 41 (77,3%) dos que tomaram oxamniquine. Ambas as drogas foram relativamente bem toleradas, com ligeira vantagem da oxamniquine.

Correlation of circulating immune complexes and complement breakdown products with the severity of the disease in human schistosomiasis mansoni

Circulating immune complexes and complements compounds were measured in serum and plasma from 66 patients with three different clinical forms of chronic schistosomiasis mansoni: intestinal, hepato-intestinal and hepatosplenic. Three different methods were used: the 125I-C1q-binding assay, conglutinin-binding assay (KgB) and Raji cell-binding assay. Approximately 25% of the patients were positive for circulating immune complexes as measured by the C1q and Raji assays. The levels of complexes increased significantly with the severity of the disease. 60% of the patients were positive for immune complexes as measured by the KgB-assay but the incidence of positive results was not clearly influenced by the stage of the disease. There was no significant correlation between immunoglobulin levels and immune complexes. The complement profile of these patients does not suggest a dramatic activation of the complement system. However, there was a progressive decrease in the plasma levels of C4 and an increase of C3d levels which correlated significantly with the severity of the disease.

What is Paragonimus rudis (Diesing, 1850)? Report on a field study in Mato Grosso, Brazil

Paragonimus rudis was found in the lungs of a giant otter Lutra (pteronura) brasiliensis by Natterer in 1828, who dissected the animal in the former capital Mato Grosso (=Vila Bela), Brazil. The flukes were described by Diesing in 1850, and redescribed by Braun in 1901. Both descriptions do not allow to identify the species. Therefore, P. rudis must be regarded a "nomen nudum". Because its rediscovery is desirable with regard to historical reasons and nomenclatoric questions, a field study was performed in Mato Grosso in 1980. Of 354 freshwater crabs from 24 localities collected and examined for parasitic infections, about 25% were found to be infected with 7kinds of trematode larvae, which differed distincly from Paragonimus-metacercariae. The question, whether P. rudis or other lung fluke species do not seem to occur or cannot be found any longer in the area investigated by us, is discussed.

Correlation between circulating antigens detected by the radioimmunoprecipitation-polyethylene glycol assay (RIPEGA) and C1q-binding immune complexes in human schistosomiasis mansoni

Circulating schistosome antigens (CSA) and circulating immune complexes (CIC) were investigated in serum from 420 patients infected with Schistosoma mansoni. The radioimmunoprecipitation-polyethylene glycol assay with [125I] anti-S. mansoni rabbit antibodies appeared as a sensitive and specific method to quantify CSA. In fact, more than 75% of the patients showed significant levels of CSA. C1q-binding CIC were also detected in 70% of subjects with schistosomiasis. In addition, a close correlation was observed between levels of CSA and CIC. These data suggest that part of the CIC present in human schistosomiasis are formed by schistosome specific antigens.

Do radically dissimilar Trypanosoma cruzi strains (zymodemes) cause Venezuelan and Brazilian forms of Chagas' disease?

316 isolates of Trypanosoma cruzi, the causative organism of Chagas' disease, were collected from three geographical areas: Venezuela, where Chagas' disease does not cause megacardia, megaoesophagus, and megacolon; the Brazilian Amazon basin, where T. cruzi is silvatic and human infection is rare; and central and eastern Brazil, where T. cruzi infection is commonly associated with "mega" syndromes. The distribution in these regions of three radically dissimilar enzymic strains or "zymodemes" of T. cruzi (Z1, Z2, and Z3) was compared. Endemic Chagas' disease in Venezuela ws predominantly due to T. cruzi Z1 and rarely to T. cruzi Z3. T. cruzi Z1 and Z3 also caused the sporadic cases of Chagas' disease in the Brazilian Amazon basin. A quite distinct T. cruzi zymodeme, Z2, not found in either Venezuela or the Amazon basin, was isolated from the vast majority of patients in central and eastern Brazil. These observations suggest that different aetiological agents might account for the difference between the Venezuelan and Brazilian forms of Chagas' disease.

Circulating antigens, immune complexes and C3d levels in human schistosomiasis: relationship with Schistosoma mansoni egg output

Circulating schistosome antigens (CSA), circulating immune complexes (CIC) and C3 breakdown product - C3d - were investigated in human schistosomiasis in comparison to the S. mansoni egg count. A close relationship was observed between the mean number of eggs/g of stool and the detection of CSA (evaluated by the radioimmunoprecipitation-PEG assay - Ripega), CIC (Clq-binding test) and C3d levels (quantitated by radial immunodiffusion). All the patients with more than 500 S. mansoni eggs/g of stool also presented antigen '4', specific of the genus Schistosoma, in the serum. A significant correlation was noticed between levels of CSA and CIC. This suggests the involvement of several schistosome antigens in the detected CIC. No relationship was noted between CIC and C3d levels. In contrast, there was a highly significant correlation between levels of CSA and C3d. The interaction between certain schistosome antigens and the complement system is discussed.

Response of plasma pancreatic and gastrointestinal hormones and growth hormone to oral and intravenous glucose and insulin hypoglycaemia in Chagas's disease

Plasma hormonal responses to insulin hypoglycaemia and to oral and intravenous glucose were investigated in chagasic patients with severe bowel disease and compared with controls matched for age, sex, weight, and race. After intravenous insulin, plasma concentrations of pancreatic glucagon and pancreatic polypeptide (PP) were reduced in the patients with Chagas's disease. These subjects also showed a subnormal rise in plasma insulin after oral glucose. Other hormone responses did not differ significantly from those in the normal controls. These results are compatible with partial denervation of the pancreatic alpha, beta, and PP cells in patients with chronic gastrointestinal Chagas's disease.

[Peripheral neurological changes in chronic Chagas' disease]

The authors review the literature about the cronic nervous form of Chagas' disease, directing their attention toward peripheral neurological aspects. Specifically, they analyse the results obtained from a "bind" research realized in a small community in the countryside of the state of Bahia, Brazil, where a high frequency of infection by Trypanosoma cruzi is reported. From 99 individuals examined, 50 showed a positive sorological test for Chagas' disease. The most frequent neurological findings in the total of 99 individuals were sensory loss and impairment of the deep reflexes. Among those with abolition of deep reflexes, there were 18 cases carrying a positive sorology for Chagas' disease, being that 15 from these 18 cases additionally presented a mild sensory deficit, characterizing a polyneuritic syndrome. In conclusion, they suggest that there is a neuritic form, as subdivision of a nervous form of Chagas' disease, particularly identified as a mixed polyneuritis.

Acquired cell-mediated immunodepression in acute Chagas' disease

In this study two groups of patients with acute Chagas' disease were identified. Group one consisted of five patients with apparent acute Chagas' disease. These patients showed symptoms and signals of an acute illness, such as high fever and enlarged spleen. One of these patients developed severe myocarditis and heart failure. Group two consisted of seven patients with inapparent acute Chagas' disease. This was a nonclinical entity, not perceived by the patient who did not seek medical care. The diagnosis was made by the shift of a serologic test which indicates the presence of immunoglobulin M antibodies to Trypanosoma cruzi. The patients with apparent acute Chagas' disease showed positive delayed-type skin response to T. cruzi antigen. Also, their leukocytes showed significant inhibition of migration in the presence of this antigen. By contrast, the patients with the inapparent acute Chagas' disease did not show positive delayed-type skin response to T. cruzi antigen and no significant inhibition was observed when their cells migrated in the presence of this antigen. Of interest, none of these patients was capable of developing contact sensitivity to 2,4-dinitrochlorobenzene. However, three out of five patients with the apparent acute disease and all the normal control subjects showed positive contact reaction after sensitization to this drug. The results of these experiments would suggest that the thymus-derived (T)-lymphocyte function is depressed in patients with the clinically inapparent acute Chagas' disease. This immunodepression seems to be acquired in the course of the T. cruzi infection because all patients showed positive delayed-type skin response to at least one ubiquitous microbial extract, thus indicating previously normal T-cell function. We hypothesize that T. cruzi antigens may directly stimulate T cells with the concomitant release of factors that might become supressive for T-cell responses. Furthermore, the suppressive effect might interfere with the T-cell response to other antigens, such as to 2,4-dinitrochlorobenzene.

Trypanosoma cruzi-sensitized T-lymphocyte mediated 51CR release from human heart cells in Chagas' disease

Cytotoxicity of T-lymphocytes from patients with Chagas' disease to parasitized and non-parasitized human heart cells labelled with 51Cr was demonstrated. The highest ratio of 51Cr released from the normal, non-parasitized heart cells was observed when the T-lymphocytes were collected from patients with acute Chagas' disease. The quantity of 51Cr released from the normal heart cells that were destroyed by T-lymphocytes collected from patients with chronic Chagas' disease was also significantly higher than the quantity of 51Cr released from normal heart cells incubated with lymphocytes from normal donors. The specific release of 51Cr from the heart cell cultures destroyed by the immune T-lymphocytes from patients with acute Chagas' disease and from patients with chronic disease was 38.1% and 25.8%, respectively, compared to the release of 51Cr observed in control studies. A small particle human heart cell antigen was shown to inhibit the migration of Trypanosoma cruzi-immune peripheral blood leukocytes. The findings appear to indicate that T-lymphocytes from patients with Chagas' disease are susceptible to activation by a cross-reactive heart cell antigen and suggest that an autoimmune mechanism can be established in some cases of acute Chagas' disease and can be perpetuated in the chronic phase of this disease by the continuous antigenic stimulation. Further, these experimental data indicate that the autoimmune destruction of heart cells in Chagas' disease is produced by delayed-type hypersensitivity mediated by T. cruzi-sensitized T-lymphocytes.

Immunological studies in human schistosomiasis. III. Immunoglobulin levels, antibodies, and delayed hypersensitivity

Levels of IgG, IgE, IgM, and IgA were determined, specific antibodies were detected by the fluorescent antibody test, hemagglutination test, complement fixation test and immunoelectrophoresis, and intradermal tests for delayed hypersensitivity to Schistosoma mansoni antigens were performed in Brazilian patients with schistosomiasis mansoni. The results were compared according to the clinical forms of the disease. IgG levels and antibody titers increased progressively in the subclinical, hepatomegalic, and hepatosplenic forms and there was a statistical relationship between IgG levels and the intensity of responses to the four serological tests; Delayed hypersensitivity (DHS) was found more frequently in hepatosplenic patients and more particularly in those with splenomegaly. DHS also correlated with age, but not with sex or with skin color. The strongest DHS reactions were observed in patients 20 to 34 years old, and in those having the highest fecal egg output. IgG levels, antibody titers, and DHS responses decreased after splenectomy and portal filtration of the worms. No significant variation was observed between untreated subjects, patients who were splenectomized and a group not subject to reinfection for 4 yearsk0

Sensitization to Schistosoma mansoni antigen in uninfected children born to infected mothers

Sensitization to Schistosoma mansoni antigen in uninfected children born to infected or uninfected mothers was studied by intradermal reaction. Immediate skin reaction, Arthus phenomenon, and delayed skin responses were noted. The skin response at 24 hr was positive in 48.1% of the uninfected children born to infected mothers, and in only 7.5% of uninfected (control) children born to uninfected mothers. Areas of skin reactions were also larger in the group born to infected mothers. Both of these differences were statistically significant. There were no significant variations according to age or sex. Only one immediate skin reaction was noted in each group, and Arthus phenomenon was never observed.

Discrepâncias entre resultados de reações de Guerreiro-Machado executadas em diferentes laboratórios

Reações de fixação de complemento feitas em três laboratórios, usando basicamente a mesma técnica, apresentaram resultados discrepantes com soros chagásicos. Somente 16 soros de um lote de 26 pacientes em fase aguda de infecção tiveram resultados positivos nos três laboratórios, embora nenhum deles fosse unanimente negativo. Quando 224 soros de casos parasitologicamente comprovados de doença de Chagas foram examinados, resultados positivos foram obtidos em 95% deles em um laboratório, 89% em outro e apenas 64% no terceiro. Os resultados mostraram que as discrepãncias observadas dependiam da qualidade dos antígenos usados, dando ênfase à necessidade não só da padronização dos preparados antigênicos, como também da metodologia do teste, a fim de se poder ter resultados comparáveis quanto à sensibilidade e especificidade da reação de Guerreiro-Machado.

Tratamento da esquistossomose com oxamniquine (xarope) em crianças

Foram tratados pela oxamniquine, sob a forma de xarope, 75 esquistossomôticos. com idade de 3 a 12 anos, distribuídos uniformente por quatro grupos, utilizando-se os esquemas de 15, 20 e 25 mg por quilo de peso corporal, em dose única e 20mg subdivididos em duas doses com intervalo de quatro horas. O controle de cura foi feito com cinco exames de fezes no período de seis meses. A dose de 20 mg, mesmo subdividida, apresentou os melhores resultados com 94,7% de cura e boa tolerabilidade. A dose de 15 mg, embora sendo a melhor tolerada, deu somente 62,5 % de cura. A dose de 25 mg foi a que apresentou pior tolerância. A eficácia das doses de oxamniquine aumenta com a idade das , crianças tratadas.

Storage of organochlorine inseticides in hepatosplenic schistosomiasis

This paper reports on the findings of a survey on OCI storage in people in Bahia, Brasil. In this survey 11 samples of adipose tissue were taken from people who underwent splenectomy for hepato splenic schistosomiasis. In these patients, total DDT averaged 10.66 ppm as compared to 4,83 ppm of total DDT found in presumably healthy people. The difference was statistically significant. It is considered that the increased DDT storage in patients with hepatosplenic schistosomiass may be the result of a reduced metabolzation of p,p'-DDT and reduced excretion of its metabolites. Another possíbility is the increased exposure to organochlorine nsectedes by hepatosplenc patients who frequently come from irrigation zones, where these compounds are more used in intensive cultivatíon.

Prova do esforço na forma indeterminada da doença de Chagas

Os autores realizaram a prova do esforço sub-máximo em 30 portadores da forma indeterminada da doença de Chagas e em 30 normais, a fim de avaliar a capacidade física e a função miocárdica. Os resultados não mostraram diferenciação do grupo positivo e do controle negativo, quanto a queixas, freqüência cardíaca ou respiratória, tensão arterial, consumo de oxigênio e alterações eletrocardiográficas.

A parasitological and serological malária survey in Amazonas, 1971

Thick blood films and malaria indirect fluorescent antibody test (P. falciparum and P. vivax) were done in four different regions in Amazonas. There was a very low prevalence of parasites anã the antibody rates suggest a small amount of transmission and that P. vivax was the predominant parasite. The calculation of probability of being infected per year was about 8% in Tefé. Coari, Colonia Fernanão Costa and Labrea and 0.8% in Anori.