Search PubMed⌕ Search

Biomedical subjects

M Dias

Publications and source records attributed to M Dias.

72 records · Page 4Linked to original sources
PubMedDate not supplied

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.

Humans↗
PubMedDate not supplied

Secondary dengue infection in schoolchildren in a dengue endemic area in the state of Rio de Janeiro, Brazil.

A seroepidemiologic survey was carried out in schoolchildren from public schools of the Niterói municipality, state of Rio de Janeiro, Brazil, after a period of sequential epidemics by dengue virus type 1 and 2 (DEN-1 and DEN-2). 450 blood samples were obtained by fingertip puncture and collected on filter paper discs. The hemagglutination inhibition (HAI) test was carried out using DEN-1 and DEN-2 antigens. HAI titres were demonstrated in 66% (297/450) of the sera and the geometric means of the titres were 1/182 and 1/71 for DEN-1 and DEN-2, respectively. Secondary infections were observed in 61% (181/297) of positive cases. Among these, 75% (135/181) were under fifteen years old. No dengue haemorrhagic fever (DHF) was reported in these children. Asymptomatic or oligosymptomatic infections were detected in 56% of the studied population. The absolute and relative frequencies of positive tests by age group and sex did not evidence statistically significant difference. The number of individuals infected probably produced a immunologic barrier responsible for the non occurrence of dengue epidemic in the latter years.

Adolescent↗
PubMedDate not supplied

[Canine visceral leishmaniasis: evaluation of the serologic method used in epidemiologic studies].

A comparative study was made of eluates of the blood of dogs experimentally infected with different trypanosomatids. Using antigens prepared from promastigotes of Leishmania mexicana, L. braziliensis and L. chagasi, assessments were made by the indirect immunofluorescence test. The results showed a sensitivity of 87.5% in the diagnosis of canine visceral leishmaniasis, independent of antigen used. Cross-reactions occurred in 75% of cases of cutaneous leishmaniasis and 83.3% of dogs with chagas' disease. An epidemiological survey in an area of leishmaniasis confirmed that immunofluorescence tests on eluates of dogs' blood give cross-reactions between L. braziliensis and L. chagasi. The results suggest that such testing could be useful in public health campaigns but attention is drawn to the fact that the level of positive reactions cannot be used as an indicator of the prevalence of canine kala-azar.

Animals↗
PubMedDate not supplied

The change of behaviour of two strains of Leishmania after cultivation in a defined medium.

Attempts have been made to characterize two strains of Leishmania that became infective to golden hamsters only after they had been maintained for several years in a chemically defined culture medium. Observations were made on the growth rates of promastigotes in vitro, course of infection in hamsters, morphology of amastigotes, and electrophoretic mobility patterns of eight isoenzymes. Information was obtained about the buoyant densities of n-DNA and k-DNA, and one strain was tested against monoclonal antibodies. The identity of both strains remains obscure.

Animals↗
PubMedDate not supplied

[Factors of recurrence of intraepithelial lesions of the uterine cervix].

MATERIAL AND METHODS: A retrospective study (1994-1996) of 282 cases of intraepithelial lesions treated in the Gynecology Services of Coimbra University Hospitals and subsequent follow-up (9-45 months). The following parameters were evaluated as recurrence factors: the patient's age, lesion degree, associated HPV infection, treatment type, safety margin in the ablative treatments and interval free of illness. RESULTS: Of the 282 cases, 72.4% (N = 204) corresponded to HSIL and 27.6% (N = 78) to LSIL. The patients' mean was 36.3 +/- 9.1 [19-67] years. The most commonly used treatment types were the LLETZ (large loop excision of the transformation zone) (76.9%) followed by CO2 LASER vaporization (16%) and finally cold-knife conization (7.1%). The safety margins were determined in 184 cases and, on average, were of 3.2 +/- 2.4 [1-10] mm. Forty-four recurrences occurred (15.6%) of which 75% corresponded to HSIL lesions (N = 33) and 25% (N = 11) to LSIL. From the total number of recurrences the association to HPV infection was found in 24 of the cases (54.5%) and 75% of these (N = 19) corresponded to HSIL. The average age in the recurrence group was 38.2 +/- 8.7 [21-53] years and 35.9 +/- 9.2 [19-67] years in the group without recurrences (p > 0.05). In the LSIL group treated with CO2 LASER (N = 32) the recurrence rate was 15.6% versus 13.3% in the group treated with LLETZ (N = 45). In the HSIL that were treated with CO2 LASER vaporization (N = 13) the recurrence rate was 23%; in those treated with LLETZ (N = 172) there were 16.2% recurrences and in the group submitted to cold-knife conization (N = 19) that rate was 10.5%. CONCLUSIONS: The total rate of recurrence was 15.6% with the greatest incidence of lesions associated to HPV (p > 0.05). Regarding the particular case of the HSIL, a great number of recurrences with the destructive treatments (CO2 LASER) was observed when compared to the ablative treatments (cold-knife conization or LLETZ).

Adult↗
PubMedDate not supplied

Assessment of a rapid HIV test strategy during labor: a pilot study from Rio de Janeiro, Brazil.

OBJECTIVES: To use two rapid human immunodeficiency virus (HIV) tests at labor, measure test acceptance and performance, and measure HIV prevalence in these women. METHODS: Between February and October 2000, two rapid tests (Determine; Abbott, Chicago, IL, U.S.A. and Double Check; Orgenics, Yavne, Israel) were used in three public maternities in Rio de Janeiro, Brazil. Enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) analysis confirmed positive and discordant results. RESULTS: Of the 858 patients who were enrolled, the mean gestational age was 36 weeks (median = 39, mode = 40) and 17 (2%) refused testing. Of the 841 patients tested, 13 were positive by both tests, which represents a 1.5% prevalence (95% confidence interval: 0.7%-2.3%); all were confirmed by ELISA and WB analysis. Seven samples gave discordant results by the rapid tests; of these, six were ELISA-negative/WB-negative and one was ELISA-negative/WB-indeterminate. The positive predictive value for samples that were positive by both rapid tests simultaneously was 100%. CONCLUSIONS: Two rapid HIV tests used at labor were well accepted (98%). When the combined results of the two rapid tests (but not a single rapid test) were analyzed, this strategy was as efficient as the standard ELISA and WB HIV strategy for correctly classifying individuals.

Blotting, Western↗
PubMedDate not supplied

Dengue: neuropathological findings in 5 fatal cases from Brazil.

Neuropathological examination of 5 patients with dengue who died of shock in Rio de Janeiro during an outbreak in summer 1987, showed nonspecific lesions (edema, vascular congestion, hemorrhagic foci and perivascular lymphocytic infiltrates). In one case with delayed marked neurological symptoms, several foci of perivenous demyelination were observed. Neurological manifestations are various and not uncommon in dengue, but their anatomical substratum is not known. An immunopathological mechanism has been postulated in some cases but has never been demonstrated morphologically. The perivenous leukoencephalitis observed in one of our cases could represent the morphological substratum of such an immunological mechanism.

Adolescent↗
PubMedDate not supplied

[Orbital myositis].

Orbital myositis is a subgroup of the nonspecific inflammatory syndrome or orbital pseudotumor and is characterized by a primary inflammation of extraocular muscles. The authors describe a 70-year-old patient with acute proptosis, ocular pain and right ophthalmoplegia, whose orbital computed tomographic scan showed enlargement of the homolateral extraocular muscles. Clinical presentation and complementary tests were compatible with the diagnosis of orbital myositis however, because of the particular aspects, which included retinal central vein occlusion, optic nerve lesion, distension of the superior ophthalmic vein and the homolateral cavernous sinus, the differential diagnosis with cavernous sinus pathology and thyroid ophthalmopathy was considered. The importance of a rapid diagnosis and treatment is stressed.

Aged↗