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Biomedical subjects

A F Mascarenhas

Publications and source records attributed to A F Mascarenhas.

13 recordsLinked to original sources
PubMed2000

Mercury exposures in riverside Amazon communities in Pará, Brazil.

Cross-sectional studies were conducted in three riverside communities in the state of Pará in the Amazon Region of Brazil. Two of these communities, Brasília Legal and São Luís do Tapajós, are located in a watershed exposed to mercury pollution from artisanal gold mining, and the third, Santana do Ituqui, is outside this area. The studies were based upon a community census and included all persons volunteering for participation in each community. All participants were surveyed by questionnaire for health history, occupation, residence, and diet. Clinical evaluations were also done on each subject, along with collection of blood, urine, feces, and hair. Fish samples were collected to represent the most frequently consumed species. Mercury was measured in hair and fish. Although no signs or symptoms of overt mercury intoxication were observed, persons in Brasília Legal and São Luís do Tapajós had higher levels of mercury in hair than residents of Santana de Ituqui, located out of the risk area. Levels of mercury in fish were below Brazilian health guidance limits, but the high rates of fish consumption among these populations raise concerns for the possible effects of chronic exposure, especially among young children and women of childbearing age.

Adolescent↗
PubMed2000

Mercury contamination of fish and exposures of an indigenous community in Pará state, Brazil.

Fish consumption is an important source of protein among indigenous communities in Amazonian Brazil. Exposures to mercury via fish were studied in an indigenous community of the Munduruku reserve, located in the Tapajós River basin in the state of Pará, one of the oldest and most productive gold mining areas in the Amazon region. This study summarizes the results of mercury (Hg) analyses of fish consumed by inhabitants of the Munduruku settlement of Sai Cinza. The most frequently consumed fish, reported by 330 persons interviewed for this study, were tucunaré, pacu, jaraqui, traíra, aracu, matrinchã, and caratinga. The mean mercury concentration in carnivorous fish was 0.297 microg.g(-1) while in noncarnivorous fish mean mercury concentration was 0.095 microg.g(-1). Only in caratinga was there a significant relationship between fish size, weight, and mercury levels. Levels of methylmercury in the tucunaré averaged 0.170 microg.g(-1), while in traíra the mean level of methylmercury was 0.212 microg.g(-1). Although the levels of Hg in fish consumed by the Sai Cinza community are below the Brazilian limit value for consumption, the high rates and amounts of fish consumed by this population are relevant to evaluating risks of mercury contamination for communities with limited food resources.

Animals↗
PubMed1993

Floral biology and breeding behavior in the bamboo Dendrocalamus strictus Nees.

Floral biology and breeding behavior were studied in the bamboo Dendrocalamus strictus Nees. The inflorescence in this species is a large branching panicle. Fertile florets are intermixed with smaller sterile ones. There are six stamens. The ovary is stipitate and turbinate. The style is long and the stigma is bifid and plumose. Dendrocalamus strictus is typically dichogamous and protogynous. The gynoecium matures 3-4 days before the androecium, effectively preventing self pollination. Flower bloom, which took place over a period of 2 to 3 h, was dependent on air temperature and only occurred between 0600 and 1300 h. Dendrocalamus strictus is anemophilous. Flowers in the male phase were visited by insects. These insects completely neglected the flowers at the female phase. The insects fed on the pollen and were not pollen vectors. When wind was excluded by enclosing the inflorescences in bags there was no seed set, indicating that cross pollination by wind is necessary for fertilization and that parthenocarpy and apomixis are not occurring in this species. Pollen fertility was about 98% as indicated by staining fresh pollen at the time of anther dehiscence and pollen release with Alexander's stain (Alexander 1969). When placed on a modified Brewbaker-Kwak medium containing 1% glucose, the pollen grains germinated well, and the pollen tubes grew to 15-20 times the diameter of mature pollen grains. Although profound protogyny has its disadvantages in times of sporadic flowering, it can be useful in breeding programs because it eliminates the need for emasculation.

Journal Article↗
PubMedDate not supplied

Antibiotic prophylaxis in biliary surgery.

Early studies in which a higher incidence of wound infection and septic complications in biliary surgery was found demonstrated the need for antibiotic prophylaxis. In two studies, one retrospective and one prospective, the role of prophylactic antibiotics in biliary surgery was studied in "at risk" and "no risk" groups of patients. Twenty-eight percent of "no risk" patients had a positive bile culture. It was concluded that a single dose of 1 g cefotaxime, administered upon induction of anaesthesia, is a safe and effective prophylactic regimen in biliary surgery.

Anti-Bacterial Agents↗
PubMedDate not supplied

[Mercury levels in fish consumed by the Sai Cinza indigenous community, Munduruku Reservation, Jacareacanga County, State of Pará, Brazil].

This study evaluated fish consumption and mercury levels in fish consumed by an indigenous community in the State of Pará. Eighty fish samples were collected (barbado, surubim, traíra, tucunaré, piranha, aruanã, caratinga, aracu, mandiá, jandiá, and pacu). Mercury analysis was performed using a Mercury Analyzer HG-3500. Average mercury concentration in carnivorous species was 0.293 (g/g (SD=0.104), while in non-carnivorous species it was 0.112 (g/g (SD=0. 036). Brazilian legislation establishes a maximum permissible limit of 0.5 (g/g for fish consumption. No significant correlation was found between fish length or weight and mercury concentration. Types of fish most frequently consumed by the community were tucunaré, pacu, jaraqui, traíra, aracu, matrinchã, and caratinga. Carnivorous species, especially tucunaré and traíra, amongst the most frequently eaten, had higher mercury levels than non-carnivorous species. Frequency of consumption is crucial to assess the risk of mercury contamination in communities who lack alternative food sources.

Animals↗