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D V Freire-Maia

Publications and source records attributed to D V Freire-Maia.

At least 19 recordsLinked to original sources
PubMed1999

Correlation between antigenemia of Paracoccidioides brasiliensis and inhibiting effects of plasma in patients with paracoccidioidomycosis.

Metabolites produced by pathogenic fungi may be involved in the pathogenesis of fungal infections consequently altering the defence mechanisms of the host. In this study the levels of Paracoccidioides brasiliensis antigens detected in the plasma of patients with paracoccidioidomycosis correlated with the suppression index detected by the low mitogenic response of peripheral blood mononuclear cells (PBMC) to phytohaemaglutinin (PHA). This inhibitory effect on lymphoproliferation was observed in the plasma of 58% of the patients, suggesting the presence of inhibitory factors. Plasma samples from paracoccidioidomycosis patients having or not having inhibitory factors showed no significant effect on chromosomes of lymphocytes from healthy individuals. However, these plasmas had a suppressive activity on the blastogenic response of these lymphocytes stimulated with PHA, that was independent of a cytotoxic effect. P. brasiliensis antigens added to the proliferative response of PBMC from healthy individuals stimulated or not stimulated with PHA showed a dose-dependent suppressor effect, reproducing the inhibitory effect of patients' plasma. We suggest that the antigens of P. brasiliensis present in the plasma of patients, even at low concentrations, can play an important role in the reduction of the cellular immune response and in the genesis of the immunoregulatory disturbances observed in paracoccidioidomycosis.

Adolescent↗
PubMed1998

Clinical, cytogenetic and toxicological studies in rural workers exposed to pesticides in Botucatu, São Paulo, Brazil.

Pesticides can cause gene mutations and chromosomal aberrations in exposed individuals. We have investigated 24 workers exposed to pesticides. Clinical examinations and cytogenetic and toxicological tests were performed. Ten non-exposed individuals were used as controls. Toxicological dosages of copper, zinc and manganese (metals found in some pesticides), hepatic enzyme dosage (GOT, GPT, AR) and acetylcholinesterase activity were performed in 16 workers and 8 controls. In the exposed workers, the most relevant clinical symptoms were poor digestion with fullness sensation after meals, irritated eyes, headache and fasciculations. The exposed group showed significantly lower manganese dosage and acetylcholinesterase activity, and significantly higher levels of alkaline phosphatase. Cytogenetic studies showed significantly higher chromosomal aberrations in the exposed group compared to the control group. Although the workers used protection against the pesticide's fog, the results revealed that the workers were contaminated with the pesticides. Therefore, the cytogenetic, toxicological studies with clinical examination are necessary for monitoring workers who are exposed to pesticides in any situation.

Adult↗
PubMed1997

Human chromosome aberrations induced in vitro by Paracoccidioides brasiliensis glycoproteic component (GP 43).

The in vitro cytogenetic effects of the 43-kDa molecular mass exocellular glycoproteic component (GP 43) from Paracoccidioides brasiliensis were studied in cultures from human lymphocytes. The sample included 10 healthy, white, non-smoking, non-related males (mean age of 31.3 +/- 8.2 years). Besides the control, three concentrations of GP 43 (0.125, 1.25 and 5 micrograms/ml) were used. In each group, around 1000 cells were examined in search of chromosome aberrations, and 30000 metaphases were analysed for the determination of the Mitotic Index. The authors conclude that GP 43 most probably causes inhibition of the cell cycle and aneugenic and clastogenic effects.

Adult↗
PubMed1994

Chromosome aberrations in lymphocyte cultures from paracoccidioidomycosis patients.

Blood cell lymphocyte chromosomes from untreated (UT) and clinically-cured (CC) patients with paracoccidioidomycosis and from healthy (control) people (CO) were studied. The frequency of aneuploid cells in the UT patients was higher than in the CC and CO individuals. The frequency of metaphase cells with premature centromere division was significantly higher in the UT than in the CC and CO group. No structural aberration and no statistically significant difference in the frequency of polyploidy was observed in the three groups studied. Our findings are indicative of an aneugenic (aneuploidy-inducing) action of infection by Paracoccidioides brasiliensis.

Adult↗
PubMed1983

[In vitro behavior of macrophages of healthy subjects and Hansen patients against Mycobacterium leprae].

The in vitro phagocytic capacity of human macrophages facing M. leprae was analysed in a selected sample of healthy and hanseniasis patients (Virchowian and tuberculoid) individuals. Families where at least one of the spouses presented Hansen's disease were selected and 176 white people were studied. The analysis of the macrophages' behavior was performed by reading the slides in the 5th, 10th, 15th, 20th and 30th days after inoculation of M. leprae. The classification is discussed. The results showed a high variability. The main conclusions reached are: (a) people differ in their capacity to lyse M. leprae, as measured by their macrophages' behavior in vitro; (b) the results obtained give support to Beiguelman's theory of the lysis threshold.

Female↗
PubMed1983

[Familial analysis of the in vitro behavior of human macrophages against Mycobacterium leprae].

The lysogenic capacity of human macrophages facing M. leprae in vitro may be dependent on an important genetic component. Although the family aggregation of the trait is demonstrated, this is a necessary but not sufficient condition to prove genetic influence. The data do not fit some simple genetic models (autosomal dominant or incompletely dominant gene; dominant or recessive sex-linked gene). The results obtained are consistent with the hypothesis that the macrophages' lysogenic capacity is mainly due to a major gene with variable expressivity. This hypothesis may be too simple to account for the whole variability detected and therefore must be considered just as a working hypothesis.

Humans↗
PubMed1983

Epidemiology and genetics of endemic goiter. I. Epidemiological aspects.

This study dealt with approximately 2,000 children and their parents living in a hyperendemic goiter area in Central Brazil, which is bounded by the jungle to the north and by a large plain to the south. The determination of goiter was made according to the methods and classification adopted by WHO. Conspicuous forms of goiter were found in 41% of the children examined. Multiple linear regression analysis showed an increase with age in the frequency of goiter in both sexes. Although data from the literature show that Mulattoes and Negroes have statistically higher frequencies of goiter than do Whites, our multiple linear regression analysis revealed no evidence for an effect of race on the endemism. There was no significant association with socioeconomic level. The presence of goiter in parents was shown to be statistically associated with its occurrence in the children.

Adolescent↗
PubMed1981

Sex and age prevalence of endemic goitre: an epidemiological study.

A hyperendemic goitre are ain the State of Mato Grosso, Brazil, has been epidemiologically surveyed, following a methodology adopted by the World Health Organization. 3,757 individuals (1,762 males and 1,995 females) have been examined. The distribution of goitre according to sex and age has been analysed through simultaneous confidence intervals for contrasts among multinomial proportions, as well as multivariate models, using computer programs. Low frequencies of goitre have been found in both males and females younger than 5, while in the older groups the frequencies were very high. Females showed higher frequencies of goitre than males in puberty and adulthood. Multivariate analyses, where 21 independent variables entered in a number of multiple regression models, confirmed the influence of age and sex on the manifestation of endemic goitre.

Adolescent↗
PubMed1981

Endemic goitre in whites and negroes: racial or social effect?

A sample of 2688 individuals, about half of them showing endemic goitre, has been studied in a hyper-endemic area of the state of Mato Grosso, Brazil. The codified data were processed in computers. Analyses through contrasts among multinominal proportions showed Negroes and Mulattoes with higher frequencies of goitre than Whites, thus agreeing with results from the literature. A number of multiple regression models, including 21 independent variables, showed no evidence of any intrinsic racial effect on the occurrence of goitre. The authors conclude that the higher prevalence of goitre among Malattoes and Negroes probably reflects the influence of their poorer socio-economic conditions. Although genetic factors are generally assumed to play some role in the development of goitre, it is to environmental causes that the most important role is ascribed.

Black or African American↗