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Biomedical subjects

A J Barros

Publications and source records attributed to A J Barros.

10 recordsLinked to original sources
PubMed2001

[Oral contraceptive and breast cancer: a case-control study].

OBJECTIVE: To investigate the association between breast cancer and the duration of use of oral contraceptives (OC), and age it started to be used in a population of Pelotas, Southern Brazil. METHODS: There were identified 250 incident cases of breast cancer in patients aged 20 to 60 years from records of pathology laboratories and there were enrolled 1,020 controls drawn from hospital and neighbourhood population. For 90 cases identified in Pelotas, 270 hospital controls and 270 neighbourhood controls were selected, for another 78 cases in Pelotas, 234 controls were selected, and for 82 cases from other municipalities, 246 hospital controls were selected. Controls were matched by age. Adjusted analysis was performed using conditional logistic regression. RESULTS: No association between oral contraceptive use and breast cancer was found (OR=1.1;CI95% 0.7 - 1.6 for hospital controls, and OR=0.9;CI95% 0.6 - 1.6 for neighbourhood controls) neither for different duration of use or starting age. To increase the test power, 250 cases and all 1020 controls were analyzed together, and an odds ratio of 1.6 (CI95% 1.0 - 2.4) was found for women older than 45 years of age who had been using oral contraceptives for five years or more. CONCLUSIONS: No evidence was found of a general association between oral contraceptive use and breast cancer. When analyzing the whole date set, with all neighbourhood and hospital controls together, for women older than 45 years of age who had been using oral contraceptives for more than 5 years, it was found an increased risk almost statistically significant (p=0.05).

Adult↗
PubMed2000

Relationship of mercury with aluminum, iron and manganese oxy-hydroxides in sediments from the Alto Pantanal, Brazil.

Sediments from nine floodplain lakes in Pantanal were analyzed for a large-scale (300 km) survey of mercury (Hg) load in sediments and soils of the Alto Pantanal and to study the relationship between Hg and reactive aluminum, iron, and manganese oxy-hydroxides. The results were compared with the Hg content in river and stream sediments from the Poconé gold mining area, where Hg has been extensively used and still is in use. The results indicate that the Hg concentrations were elevated in river sediment close to the mining area in Bento Gomes river basin (average in the < 74-microm fraction 88.9 ng Hg g(-1) dry wt.; interquartile range 50.3-119.5), but there was no clear indication that the local Hg emissions have contaminated the remote floodplain lakes, where concentrations were surprisingly low (average in the < 74-microm fraction 33.2 ng Hg g(-1) dry wt. sediment; interquartile range 18.4-46.8), in particular when considering geochemical characteristics of the sediment. The sediment from the floodplain lakes contained less Hg-tot and more reactive iron oxy-hydroxides than soils from the Tapajós area in the Amazon basin. This resulted in a mass ratio between Hg and amorphous oxy-hydroxides of only 5 x 10(-6) for Hg-tot/Fe-oxa (interquartile range 3-7 x 10(-6).

Aluminum↗
PubMed1999

Preventing acute respiratory infections and diarrhoea in child care centres.

This study was designed to explore the physical characteristics and child care practices of child care centres as potential risk factors for respiratory infections and diarrhoea in children 3-35 mo of age. A dynamic cohort averaging 667 children from 40 child care centres in Campinas (Brazil) was followed up for 8 mo. Direct structured observations were made to collect information on the centres' physical structure, child activities and child care practices. Despite their good infrastructures, hand washing in the centres was infrequent, and nearly 30% of diaper changes were unhygienic. Risk factors for diarrhoea included the presence of flies during meals, infrequent child hand washing before meals, and infrequent child hand washing after defecation, with relative risks of 1.33, 1.73 and 1.63, respectively. There was 33% less diarrhoea in classes where soap was frequently used during diapering. Contrary to our hypotheses, ventilation, group size and child density were not associated with respiratory infections, as was the case for most other factors studied. Only mixing of groups and a larger classroom area were found to be negatively associated with lower and upper respiratory infections, respectively. The results indicate that improving hygiene practices is the only intervention in child care centre characteristics with good potential to reduce diarrhoea among attendees. For respiratory infections, no modifiable characteristic with intervention potential was identified.

Brazil↗
PubMed1999

Child-care attendance and common morbidity: evidence of association in the literature and questions of design.

Papers on child-care attendance as a risk factor for acute respiratory infections and diarrhea were reviewed. There was great variety among the studies with regard to the design, definition of exposure and definition of outcomes. All the traditional epidemiological study designs have been used. The studies varied in terms of how child-care attendance in general was defined, and for different settings. These definitions differed especially in relation to the minimum time of attendance required. The outcomes were also defined and measured in several different ways. The analyses performed were not always appropriate, leading to sets of results of uneven quality, and composed of different measures of association relating different exposures and outcomes, that made summarizing difficult. Despite that, the results reported were remarkably consistent. Only two of the papers reviewed failed to show some association between child-care attendance and increased acute respiratory infections, or diarrhea. On the other hand, the magnitude of the associations reported varied widely, especially for lower respiratory infections. Taken together, the studies so far published provide evidence that children attending child-care centers, especially those under three years of age, are at a higher risk of upper respiratory infections, lower respiratory infections, and diarrhea. The studies were not consistent, however, in relation to attendance at child-care homes. Children in such settings were sometimes similar to those in child-care centers, sometimes similar to those cared for at home, and sometimes presented an intermediate risk.

Child↗
PubMed1999

[Low prevalence of bodyweight-for-height deficit: comparison of stunned and no-stunned Brazilian children].

OBJECTIVES: The aim of this study was to investigate the relationship between abdominal circumference and weight-for-height in children. The average of 18 anthropometric and body proportionality indexes were compared among four groups of children: stunted and non-stunted Brazilians, Peruvians and North-Americans. METHODS: There were studied 386 children aged 6-59 months living in a poor neighborhood in Pelotas, Brazil. Anthropometric measurements (weight, recumbent length or height, sitting height or crown-rump length; head, chest, upper arm and abdominal circumferences; triceps, biceps, subescapular and suprailiac skinfold thickness; biacromial and biiliac breadths) were obtained. Muscle, fat, total upper arm areas, leg length and body proportionality indexes were calculated. RESULTS AND CONCLUSIONS: The study sample showed high levels of morbidity, low parental educational levels, poor access to health services and poor housing conditions. Stunted Brazilian children had lower means for most of the anthropometric measurements when compared to non-stunted Brazilians and North-American children. However, stunted children showed larger abdominal, head and thoracic circumference in relation to their stature than non-stunted children. The low prevalence of weight-for-height among the children of this study is not a result of excess of fat or muscle tissue, and may be partly explained by an increase in head and trunk dimensions (including abdominal circumference) relative to the child's stature.

Abdomen↗
PubMed1998

[Estimating the prevalence of height for age deficits based on the prevalence of weight for age deficits among Brazilian children].

INTRODUCTION: Anthropometry is frequently used for evaluating nutritional status of individuals and populations. In recent years, community surveys have been conducted by health professionals in various regions of Brazil with the objective of complementing the data obtained through nutritional surveillance programs. One important difficulty in conducting these assessments has been measuring height during visits to the homes of survey participants. METHODS: Thirty-eight anthropometric surveys of Brazilian children aged up to 5 years using the National Center for Health Statistics (NCHS) reference were identified. The percentage of children with a Z-score below standard deviations was used to define deficits of weight for age and height for age. RESULTS: Correlation between prevalences of height for age and weight for age deficits were examined. Due to the low prevalence of deficits in weight for height in all surveys, there was a strong correlation between weight for age and height for age at the population level. Approximately 90% of the height for age (H/A) variation was accounted for by that of weight for age (W/A). CONCLUSIONS: Using the equation, (Prevalence H/A) = 0.74 + 2.34 (Prevalence W/A) -0.03 (Prevalence W/A)2 it is possible to estimate the prevalence of height deficits on the basis of prevalence of weight deficits. These results suggest that anthropometric surveys as conducted in Brazil, in the context of health services, can be simplified by measuring weight only, instead of both weight and height.

Age Factors↗
PubMedDate not supplied

[Daycare centers in a medium-sized Brazilian city: operations, child-care practices, infrastructure, and safety].

Ninety-two daycare centers (23 public, 10 charitable, and 59 private) were identified in the municipality of Pelotas, RS, Southern Brazil. These centers were studied in relation to their organization, services, child-care practices, and infrastructure. All public centers worked full-time, while most private centers operated in the afternoon and received a smaller proportion of children under the age of two. The child-to-attendant ratio was similar in both types of centers, and the nurseries were the classes most frequently above the recommended maximum. Group and center sizes were larger in the public centers. Attendant schooling was higher in the private centers, but task specificity was lower. The infrastructure deficiencies most commonly observed in the public centers were lack of an internal recreational area and playground equipment. Private centers lacked adequate diapering facilities and exclusive toilets for the children. A small proportion of centers had staff trained to handle fire emergencies and administer first aid, revealing insufficient concern over safety issues.

Administrative Personnel↗
PubMedDate not supplied

[Understanding the low prevalence of weight-for-height deficit in lower-income Brazilian children: correlations among anthropometric values].

The sample for this study consisted of 386 children from six to 59 months of age. The objective was to study the association between wasting and abdominal circumference. Thirteen anthropometric measurements were taken: weight, height or length, crown-rump length, 4 circumferences, 4 skin fold thicknesses, and 2 breadths. Muscle, fat, and total upper arm areas and leg length were calculated. Indices of body proportionality were obtained by dividing the anthropometric variables by height. Height-for-age, weight-for-age, and weight-for-height deficits were 25.9%, 14.4%, and 3.5%, respectively. The smallest and lightest children were those with the highest abdominal circumferences divided by height. According to this study, abdominal circumference for Brazilian children without height-for-age deficit is, on average, 1.2 cm larger than for US children. Using this as a basis, the study calculated that prevalence of weight-for-height deficit would increase from 3.5% to 7.0% by increasing 2 cm in the abdominal circumference. The low prevalence of wasting and the high prevalence of stunting as indicated by several Brazilian studies could be explained partially by larger mean abdominal circumference values.

Age Factors↗
PubMedDate not supplied

[Public and private day-care centers in Pelotas, RS: compliance with the regulations]

OBJECTIVES: Seventy-seven day-care centers were evaluated in Pelotas, RS, Brazil, in 1996, in order to assess compliance with current service regulations. METHODS: Information about physical structure, facilities, equipment, hygiene practices, and day-care staff was collected through a structured questionnaire. RESULTS: The median number of children in public day-care centers was 89 children per center, while in the private centers the median was 29 children per center (p<0.001). A nursery was available in 88% of public day-care centers, and in 36% of the private centers (p<0.001). Concerning the physical structure, the majority of the public centers had exclusive toilet facilities for the children (91%), while this was the case in only 66% of the private centers (p<0.001). Fire extinguishers were found in public centers in a proportion three times higher than in the private centers. Proper bottle washing and refrigeration was done in 95% of the day-care centers studied, while sterilization of the bottles was reported in only 47% of the centers. Despite the fact of 85% of the centers kept records with health information on the children, 93% of the centers did not have the required health license provided by the municipal authority. CONCLUSIONS: There is a good deal of work to do in both private and public day-care centers in order for them to comply with the current service regulations.

Journal Article↗