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Biomedical subjects

F S Barbosa

Publications and source records attributed to F S Barbosa.

At least 19 recordsLinked to original sources

[Not Available].

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Journal Article↗

[An alternative model for schistosomiasis control: the present status of the project in the State of Espírito Santo, Brazil].

An intervention study for schistosomiasis control is being carried out in the county of Afonso Cláudio, state of Espírito Santo, Brazil, having begun in February 1992. This study is an alternative response to classical control methods. The project is being developed using an interdisciplinary approach and involves both research and service institutions. The organization of health services at the primary care level is part of the project. Participant observation is seen as the methodological point of departure for guiding data collection and analysis and the intervention process in local reality. Control methods are restricted to the medical treatment given to all infected individuals and to improvements in the sanitation facilities available in the area. These methods are obviously integrated with the above-mentioned social actions. Consisting of three phases - pre-control, control (intervention), and final evaluation - the project is now in its intervention phase, lasting approximately three years.

English Abstract↗

Long-term controlled field experiment on the competition between two species of Biomphalaria (Mollusca, Basommatophora), the snail vectors of Schistosoma mansoni in Northeastern Brazil.

A long-term controlled field experiment on the interactions of the populations of Biomphalaria glabrata (target population) and B. straminea (competitor) was carried out in the county of Alhandra, state of Paraíba, Brazil, during the period 1980 through 1989. Results obtained in the current paper show that the snail B. straminea has strong competitive advantages over B. glabrata. In six out of nine streams the native population of B. glabrata were totally excluded and replaced by B. straminea. There is evidence showing that seasonal dryness has marked influence on the phenomenon studied in this paper. In all the streams were B. straminea already predominated, return of B. glabrata was never observed.

Journal Article↗

The bioecology of snail vectors for schitosomiasis in Brazil.

This paper describes the ecology of two species of Biomphalaria: B. glabrata and B. straminea. These species have been intensively studied in Brazil and in other countries since the 1950s. The literature in this area can be broadly subdivided into three categories, linked to three distinct historical periods: 1) an accumulated store of early studies carried out in the laboratory and in the field; 2) the development of quantitative ecological models; and 3) the development of an alternative methodology for breeding snails under seminatural conditions.

Journal Article↗

[Hepatosplenic forms of schistosomiasis mansoni in the interior of Northeastern Brazil].

Field studies on the morbidity of schistosomiasis mansoni were carried out in some rural endemic areas of Northeastern Brazil during the first semester of 1991. These cross-sectional studies were limited to the assessment of the gradient of clinical forms of the disease. The entire population present in a house-to-house survey was examined. Results have shown a reduction in the prevalence rates of the more severe form of schistosomiasis, the hepatosplenic form, when compared with previous similar studies made in the same areas during the 1960s and 1970s. Changes in prevalence rates of the severe clinical forms from the younger to the older age groups were observed.

English Abstract↗

[Ecoepidemiology of urban schistosomiasis in Itamaracá Island, Pernambuco, Brazil].

INTRODUCTION: In 1988, 22 autochthonous cases from accidental exposure were registered in Forte Orange beach, Itamaracá Island, Pernambuco, Brazil. All cases occurred in middle-to-upper class individuals who were vacationing in the island. After the cases were identified, the major objective was to find breeding sites of schistosomiasis vectors and correlate the biological factors with the environmental conditions. METHODS: The environmental characteristics of the beach before human occupation were obtained from several documents. Also, a one-year malacological survey was conducted with monthly collection of mollusks, and the determination of their infectivity rates. RESULTS/CONCLUSIONS: The malacological survey was able to identify 20 breeding sites of Biomphalaria glabrata and 28 capture station were set up. Snails were collected and examined each month throughout a whole year. The results show a seasonal variation in the mollusk population density associated with infection rates and types of breeding sites. The importance of this new epidemiological profile of schistosomiasis in the State of Pernambuco relies on the fact that it can be related with the drastic human interference on the environment. Ecological, environmental, and demographic factors as well as the epidemiological characteristics of the disease have social and economic repercussions.

Animals↗

Possible hybridization of Brazilian planorbid snails and its importance in population dynamics.

This study focuses on the possibility of experimental hybridization among host snail species for Schistosoma mansoni in Brazil, with morphological characterization of the hybrids found. By using albinism as a genetic marker, intraspecific crossbreedings were performed between two strains of each species involved, in addition to interspecific crossbreedings; the only viable crossbreeding was between pigmented Biomphalaria glabrata (Paulista, PE) and albino B. tenagophila (Joinville, SC), with the formation of F1 and F2 generations. All offspring in F1 displayed black eyes and a renal ridge on the mantle, while F2 displayed dissociated morphological traits. With regard to reproduction, F1 was more efficient than F2. The experiment's results suggest post-zygotic reproductive isolation.

Albinism↗

[Schistosomiasis: reproduction and expansion of the endemia to the state of Pernambuco in Brazil].

Schistosomiasis mansoni can be considered an important public health problem in Northeastern Brazil, in spite of the reduction in the prevalence of the hepatosplenic clinical forms which have been attributed to the large scale use of chemotherapy in this country. However, the rise in the prevalence rates and the spread of this endemic disease to new areas show that schistosomiasis is assuming its must cruel expression: less lethal but more greatly incapacitating in terms of irreversible physical and moral damage to human beings. The state of Pernambuco presents growing rates for schistosomiasis infection in humans. The epidemiological profile of this disease displays high and consistent prevalence rates (up to 80%) in rural areas, and new cases of acute infection on the coast, where schistosomiasis has recently been introduced. The reproduction and expansion of this endemic disease can be better understood on the basic of a conception of structural and historical causation. The disease construction process should be reconstructed in the light of biological as well as the social, political and cultural factors which are jointly responsible for the present endemic situation. Within that frame work, the historical and socioeconomic features that interact with the parasite and give rise to the present proportions of the schistosomiasis epidemic in Pernambuco are discussed. The mode of occupation and use of the land, unemployment, under-nutrition, migration, etc., raise the question of the growing difficulties confronting the control of the disease, both in rural areas where populations are extremely mobile as well as in the poorly organized urban population. Epidemiological investigation is fulfilling its role in its attempts to understand the complex relationships of an intrinsecally social nature of the health/disease process between health problems and the quality of life for the purpose of producing consistent disease control models.

Brazil↗

Alternative approaches in schistosomiasis control.

Measures for the control of schistosomiasis were implemented in Egypt beginning 1922. This shows that developing endemic countries are facing this problem for near 70 years. However, results in the control of this infection have not been satisfactorily obtained in spite of the technologies and strategies recently developed. The idea that social and economic components are relevant in the control of schistosomiasis is not new although its extension and profundity have not usually been well understood. More recently, most of the workers have recognized that the focal distribution of the prevalence rates of schistosomiasis should not be neglected in the control of the infection. At present, field work projects on the control of schistosomiasis are being developed in rural areas of two Brazilian studies (Espírito Santo and Pernambuco). The adopted strategy aims to interfere in the complex relationships between man and his bio-social-cultural environment, without forgetting that the unequal distribution of the space is a consequence of the political and economic organization of the Society.

Animals↗

Competitive displacement of Biomphalaria glabrata by B. straminea.

Data on the interaction between populations of closely related species of Biomphalaria, B. glabrata and B. straminea, are presented in the current paper. Laboratory and field observations and experiments have shown that B. straminea has competitive advantages over B. glabrata.

Animals↗

Adrenal cyst.

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Adrenal Gland Diseases↗

Incapacitating effects of schistosomiasis mansoni on the productivity of sugar-cane cutters in northeastern Brazil.

Studies were carried out on two sugar estates in the humid coastal forest region of northeastern Brazil, a highly endemic area of schistosomiasis mansoni. Results obtained in a retrospective study were not conclusive, but clear-cut results emerged from a prospective study. The latter was conducted on a sugar estate (Catende) where the severe hepatosplenic clinical form of the disease is seen in 4% of the field-working population. Comparison was made between two groups of paired subjects: one composed of workers with the hepatosplenic form of the disease and the other composed of workers with the intestinal form. Reduction of productivity among the hepatosplenic subjects compared to intestinal subjects was 35.1%. The loss to the Catende sugar estate from reduced productivity caused by schistosomiasis mansoni for the harvest season of 1978 was calculated as 0.93% of the estate's total production, or approximately US$135,000. When this figure is extrapolated to the State of Pernambuco (16 million tons of sugar total annual production), the annual loss in the state if estimated to be US$2 million.

Adolescent↗