Clinical, parasitological and immunological aspects of experimental infection with Trypanosoma evansi in dogs.

This research investigated the pattern of antibody response by means of enzyme linked immunosorbent assay (Elisa) and indirect fluorescent antibody test (IFAT) through the course of experimental Trypanosoma evansi infection in dogs. Clinical and parasitological features were also studied. The average prepatent period was 11.2 days and parasitaemia showed an undulating course. Biometrical study of parasites revealed a mean total length of 21.68mm. The disease was characterized by intermittent fever closely related to the degree of parasitaemia and main clinical signs consisted of pallor of mucous membrane, edema, progressive emaciation and enlargement of palpable lymph nodes. Diagnostic antibody was detected within 12 to 15 days and 15 to 19 days of infection by IFAT and Elisa, respectively. High and persistent antibody levels were detected by both tests and appeared not to correlate with control of parasitaemia

Strongyloidiasis in patients with hematologic malignancies.

We retrospectively studied 343 consecutive patients treated between 1979 and 1992. Ninety patients whose stool was not examined were excluded. Fifty-three patients with strongyloidiasis were compared with 200 controls with regard to outcomes and the following characteristics: age, sex, underlying disease, use of corticosteroids, abdominal pain, diarrhea, fever, pulmonary symptoms, and eosinophilia. Patients with strongyloidiasis more commonly had eosinophilia (P = .01) and fever (P = .03). There was a single but fatal case of the disseminated disease syndrome (1.9% of patients with strongyloidiasis). In multiple logistic regression analysis, the factors predictive for strongyloidiasis were schistosomiasis (odds ratio [OR], 6.58), ascariasis (OR, 2.78), and the use of steroids (OR, 2.29). Strongyloidiasis was highly prevalent among patients with hematologic malignancies in Brazil. Occurrence of the disseminated disease syndrome seems to be unusual.

An assessment of soil-to-plant concentration ratios for some natural analogues of the transuranic elements.

A field study was conducted in an area of enhanced, natural radioactivity to assess the soil to edible vegetable concentration ratios (CR = concentration in dry vegetable/concentration in dry soil) of 232Th, 230Th, 226Ra, 228Ra, and the light rare earth elements (REE's) La, Ce and Nd. Twenty-nine soil and 42 vegetable samples consisting of relatively equal numbers of seven varieties were obtained from 11 farms on the Pocos de Caldas Plateau in the state of Minas Gerais, Brazil. This region is the site of a major natural analogue study to assess the mobilization and retardation processes affecting Th and the REE's at the Morro do Ferro ore body and U series radionuclides at a nearby open pit U mine. Thorium (IV) serves as a chemical analogue for quadrivalent Pu and the light REE's (III) as chemical analogues for trivalent Am and Cm. The geometric mean CR's (all times 10(-4] decreased as 228Ra (148) greater than 226Ra (76) greater than La (5.4) greater than Nd (3.0) = Ce (2.6) greater than 232Th (0.6), or simply as M (II) greater than M (III) greater than M (IV). These differences may reflect the relative availability of these metals for plant uptake. Significant differences were found in the CR's (for any given analyte) among many of the vegetables sampled. The CR's for the different analytes were also highly correlated. The reasons for the correlations in CR's seen among elements with such diverse chemistries as Ra-REE or Ra-Th are not clear but are apparently related to the essential mineral requirements or mineral status of the different vegetables sampled. This conclusion is based on the significant correlations obtained between the Ca content of the dried vegetables and the CR's for all of the elements studied.

[Cesium-157 in milk produced on farms of the Angra dos Reis Region, RJ]. / Césio-137 em leite produzido em fazendas da Região de Angra dos Reis, RJ.

The first Brazilian Nuclear Power Plant is located in the Angra dos Reis county, about 130 km West of Rio de Janeiro. Among the radionuclides that will be released to the environment by the Nuclear Plant, tritium and radioisotopes of Cs, I, Co and Sr are the ones of greatest potential impact on the local population. During the preliminary phase of the pre-operational environmental radiological program, 137Cs resulting from nuclear explosion fallout was detected in milk samples from only one farm, among the ones included in the monitoring program. This finfing seemed odd, leading to believe on the possibility of a soil anomaly on the region, in which 137Cs would be more available for plant uptake than in normal areas, as it has been observed in some areas in various countries. Trying to explain this issue, the Radioisotopes Laboratory of the Biophysics Institute and the Radioecology Laboratory of FURNAS decided to carry on a series of analyses of 137Cs in milk, pasture and soil collected in the four farms of the program. The results demonstrated the non-existence of a soil anomaly in the region regarding the 137Cs behavior Cesium-137 concentrations in milk varied from 0.06 to 0.93 Bq/l but the differences of the average values in the four farms were not statistically significant. In one farm, occasional high peaks of 137Cs concentrations in milk were observed, which seemed to be related to the cattle management. Apparently during certain periods, the cattle grazes in sectors whose 137Cs concentrations in soil and pasture are higher than in other areas of the same farm or the region, due to the influence of micro-climate and erosion of superficial soil.