Ischaemic colitis (necrotizing colitis, pseudomembranous colitis) in acute schistosomiasis mansoni: report of two cases.

Two cases of ischaemic necrosis of the sigmoid colon (necrotizing colitis) are reported in 2 brothers aged 7 and 4 years, diagnosed within a 10 d interval. The children had bathed in streams suspected to be contaminated by Schistosoma mansoni about 50-60 d before the onset of acute disease. Both patients had been previously exposed to schistosome-infected streams without showing signs or symptoms of infection. Before admission, S. mansoni eggs had not been found in the stool. Both patients presented with an apparently identical, relatively symptomatic clinical course with rapid evolution to an acute abdomen. Laparotomy disclosed, in both patients, extensive necrosis (ischaemic necrotizing colitis of schistosomal aetiology) of about 20 cm in the first child and 8 cm in the second, extending from part of the descending colon to the sigmoid. The patients were successfully operated upon (hemicolectomy plus colostomy). The histopathological findings were similar in both patients. Ischaemic necrosis with complete destruction of the mucosa and part of the submucosa was detected in the first case; in the necrotic areas a few eggs of S. mansoni were seen, with no granulomatous reaction, but surrounded by cell shadows, pycnotic nuclei and amorphous material. Necrosis extended to the muscular layer and serosa, in which schistosome granulomas in the necrotic-exudative phase were seen, as well as diffuse granulocytic exudate and fibrin. Sections of tissue from both patients contained numerous eggs and granulomas all in the same exudative phase in regional lymph nodes and near the thrombotic vessels. After surgery, the 2 patients progressed similarly. About 10 d after hospital discharge, the patients received anti-schistosomal treatment with oxamniquine. No further sign of infection was detected at subsequent recall visits.

Pulmonary schistosomiasis mansoni: post-treatment pulmonary clinical-radiological alterations in patients in the chronic phase: a double-blind study.

A double blind trial was set up to study the pulmonary effects of specific treatment with oxamniquine of 40 patients with chronic schistosomiasis mansoni. Radiological alterations characterized by bronchopneumonitis were seen in 17.5% of the patients after treatment, but in none of the placebo group; non-migratory condensation occurred between 25 and 72 h after treatment, with a mean duration of 7 d. 86% of the patients showed spontaneous healing with no radiological sequelae after 30 d of follow-up. Slight pulmonary clinical manifestations without any functional repercussions were also seen. The alterations were probably related to the host-parasite interaction, and the lesions may have been caused by deposition of immune complexes in the lungs with local activation of complement.

Histological observations on Montenegro's reaction in man.

The Montenegro skin test is widely used as a diagnostic method for American cutaneous leishmaniasis (ACL) but little is known about the histological changes that occur in the skin after administration of the antigen. This report is based on histological studies of biopsied material obtained, from inoculation sites, 48 hours after individuals had been given intradermal injections with a standardized Montenegro antigen. The material examined was obtained from four distinctly different test groups: naturally infected patients with parasitologically proved ACL and with positive Montenegro's reaction; individuals without previous history of ACL and not previously tested with Montenegro antigen; participants in anti-ACL vaccine trials who developed positive reactions to Montenegro antigen after vaccination; other participants in vaccine trials who had negative Montenegro responses after vaccination or had served as controls in the trials. The histological pictures of each group are described and discussed. Histologically, the reactions of vaccinated individuals were indistinguishable from those with naturally acquired infections.

Aspects of the granulomatous reaction in the liver of mice infected and reinfected with two different geographical strains of Schistosoma mansoni.

In this study, which was undertaken in relation to the histopathologic behavior of two different strains (LE-Belo Horizonte, MG and SJ-São José dos Campos, SP) in infections and reinfections (homologous or heterologous) with Schistosoma mansoni, the authors confirmed a more accentuated pathogenicity of the SJ strain. All the reinfections showed the presence of typical granulomas of the acute phase, when performed either with the same strain (homologous) or with a different strain (heterologous) of the parasite of the primo infection. The possible mechanisms responsible for reactivation of the immunopathologic response in reinfections are discussed.

Schistosoma mansoni in mice: modulation of granulomatous response after reinfection and chemotherapeutic treatment.

Mice previously infected with Schistosoma mansoni, and cured by specific treatment (400mg/kg oxamniquine, p.o.) in the chronic phase of the disease, were reinfected 20 days after treatment to assess their capacity for modulation of the granulomatous response. Histopathologic examination of the animals' liver, at 60 days after reinfection, evidenced the presence of typical granulomas of the chronic phase in most animals. This infer that the capacity for modulation of the granulomatous response had been maintained, thus preventing a new acute phase of the disease. Conversely, a group of previously infected mice, untreated and submitted to reinfection, showed reactivation of the granulomatous response in 50% of the animals. The possible implications of these findings in human schistosomiasis mansoni are discussed.

[Comparative histopathologic study of the skin test in dogs from an endemic area of tegumentary leishmaniasis, using 2 antigens: Leishvacin and P10.000G]. / Estudo histopatológico comparativo do teste cutâneo em cães de área endêmica de leishmaniose tegumentar, utilizando dois antígenos: Leishvacin e o P10.000G.

The Montenegro skin test is widely used as a diagnostic method for American cutaneous leishmaniasis (ACL). However, there is little information about the histological changes that occur after administration of the antigen, especially in dogs. Two intradermal reactions were used in mongrel dogs during a clinical and epidemiological study as a diagnostic method for canine cutaneous leishmaniasis at Virginópolis, Minas Gerais, Brazil. Leishvacin and P10,000G were used as antigens. The inflammatory reaction was more intense and diffuse in dogs tested with P10,000G than Leishvacin.

[Distribution of types I and III collagens in hepatic cirrhosis by the picrosirius polarization method]. / Distribuicão do colágeno I e III na cirrose hepática pelo método picrosirius polarizacão.

The distribution of types I and III collagen fibrils was analysed in liver fragments of 18 cases of alcoholic hepatic cirrhosis. Using the method of picrosirius polarization the collagen fibrils type I and III were found to be very increased in both intra and extralobular connective tissue. Type I fibrils were more frequent in the extralobular tissue and type III in the intralobular connective tissue.