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Biomedical subjects

C S Oliveira

Publications and source records attributed to C S Oliveira.

11 recordsLinked to original sources

Osteogenic index of step exercise depending on choreographic movements, session duration, and stepping rate.

BACKGROUND: Step exercise has been promoted as a low impact physical activity recommended for the improvement of cardiorespiratory and muscular fitness. This recreational activity might also be recommended to improve bone health since mechanical load plays an important role in the normal development of the skeleton. METHODS: Our main purpose was to characterised 100 step sessions and to calculated osteogenic index (OI) according to Turner and Robling: OI (one session) = peak ground reaction force(BW)*ln(number of loading cycles+1). RESULTS: Main results (mean+/-SD) were as follows: OI was 12.0+/-0.8; peak ground reaction force (GRF) was 1.40+/-0.10 times body weight (BW); session duration was 38.6+/-8.3 min; stepping rate was 134.6+/-4.7 beats per minute (bpm); the movements performed most often were marching, knee hop, side leg, L step, and over the top; and the number of loading cycles was 4194.1+/-1055.2. OI and GRF increased significantly when stepping rate was higher than 135 bpm. This stepping rate might be used as a reference for higher intensity classes. A frequency of two to three sessions per week of step exercise is recommended. CONCLUSIONS: Despite the benefits that have been stated when step classes are structured correctly and adapted to the participants, further research is needed concerning biomechanical load, exercise prescription, and injury prevention.

Analysis of Variance↗

Casualty treatment after earthquake disasters: development of a regional simulation model.

This paper presents a new approach to the casualty treatment problem following a large-scale disaster, based on a mathematical model of how a regional health-care system responds to an earthquake event. The numbers and locations of casualties rescued alive, the scale of pre-hospital care, the post-earthquake hospital capacity, and the transport system are inputs to the model. The model simulates the movement of casualties from the stricken areas to hospitals. It predicts the number of casualties that die as well as other statistics about the health-care system response, such as waiting time before treatment. The model can be run with varying input assumptions to simulate alternative disaster response strategies. Preliminary runs demonstrate the potential of the model as a tool for planning and training.

Disaster Planning↗

[Rotavirus: clinical features and prevention]

OBJECTIVES: This report was prepared with the main objective of making an extensive review of both clinical features and prevention of rotavirus gastroenteritis. In addition, it provides an evaluation about the potential for introduction of the tetravalent rhesus-human reassortant rotavirus vaccine (RRV-TV) in the developing countries. METHODS: The main source of information was the most relevant articles published in both national and international journals, as well as selected official reports from the World Health Organization. With regard to rotavirus vaccines, particular emphasis has been placed on the results available from studies carried out during the past five years. Notice we have stressed the epidemiological features of rotavirus infections in Brazil. RESULTS: As a background for the main subjects of this report - clinical features and prevention - available general information on rotavirus infections are briefly discussed in the Introduction. This includes an overview of the etiological agent, epidemiology, immunity and laboratory diagnosis. A detailed description of the typical symptomatic syndrome is made, as well as of other (unusual) clinical manifestations of rotavirus illness. We also discuss the rotavirus candidate vaccines that have been evaluated to date, highlighting the most significant observations which resulted from field trials with the RRV-TV in several countries. The potential for large-scale use of RRV-TV in developing countries is also discussed, focusing mainly on the epidemiological characteristics of rotavirus disease in these regions. CONCLUSION: Rotaviruses are the leading cause of severe gastroenteritis in infants and young children in both industrialized and lessdeveloped countries; in the latter regions, rotavirus diarrhoeal disease represents a major cause of mortality. There is currently a consensus that attempts at prevention need to be directed toward the development of an effective rotavirus vaccine, for large-scale use, that would primarily protect children (aged 0 to 2 years) against severe rotavirus gastroenteritis. In this regard, results from a recent reevaluation of the Peruvian and Brazilian lower-titer RRV-TV efficacy data are promising. Although the RRV-TV ("Rotashield(R)") (recently licensed for general use in U.S.A.) seems to be currently the most promising rotavirus vaccine, it has been suggested that further trials with this vaccine should be conducted in Africa and Asia (efficacy studies) and Latin America [immunogenicity and effectiveness (efficacy under real conditions in a given setting)]. In addition, it is of paramount importance to establish in these regions a surveillance system to monitor the circulating rotavirus strains.

Journal Article↗

An outbreak of group C rotavirus gastroenteritis among children attending a day-care centre in Belém, Brazil.

In August 1993, an outbreak of group C rotavirus-associated gastroenteritis occurred among children attending a day-care centre in Belém, Brazil. Of the 64 children, 21 (33%) became ill. Group C rotavirus was identified in faecal specimens from 8 (38%) children with diarrhoea by electron microscopy (EM) and an enzyme immunoassay (EIA), using antibodies specific to the Cowden strain of porcine group C rotavirus. By polyacrylamide gel electrophoresis (PAGE), a pattern similar to that of group C rotavirus was observed in 5 (62.5%) of the 8 EM- and EIA-positive samples. These 5 faecal samples were confirmed to be positive for group C rotavirus by reverse transcriptase-polymerase chain reaction, using specific VP6 and VP7 primers. This is the first report of an outbreak of diarrhoea in North Brazil associated with group C rotavirus. These findings suggest that group C rotavirus may be an important aetiological agent of diarrhoea in this region, which requires further study.

Brazil↗

Immunogenicity, safety and efficacy of tetravalent rhesus-human, reassortant rotavirus vaccine in Belém, Brazil.

A tetravalent rhesus-human reassortant rotavirus (RRV-TV) vaccine (4 x 10(4) plaque-forming units/dose) was evaluated for safety, immunogenicity and efficacy in a prospective, randomized, double-blind, placebo-controlled trial involving 540 Brazilian infants. Doses of vaccine or placebo were given at ages 1, 3 and 5 months. No significant differences were noted in the occurrence of diarrhoea or vomiting in vaccine and placebo recipients following each dose. Low-grade fever occurred on days 3-5 in 2-3% of vaccinees after the first dose, but not after the second or third doses of vaccine. An IgA antibody response to rhesus rotavirus (RRV) occurred in 58% of vaccinees and 33% of placebo recipients. Neutralizing antibody responses to individual serotypes did not exceed 20% when measured by fluorescent focus reduction, but exceeded 40% when assayed by plaque reduction neutralization. There were 91 cases of rotavirus diarrhoea among the 3-dose (vaccine or placebo) recipients during two years of follow-up, 36 of them among children given the vaccine. Overall vaccine efficacy was 8% (P = 0.005) against any diarrhoea and 35% (P = 0.03) against any rotavirus diarrhoea. Protection during the first year of follow-up, when G serotype 1 rotavirus predominated, was 57% (P = 0.008), but fell to 12% in the second year. Similar results were obtained when analysis was restricted to episodes in which rotavirus was the only identified pathogen. There was a tendency for enhanced protection by vaccine against illness associated with an average of 6 or more stools per day. These results are sufficiently encouraging to warrant further studies of this vaccine in developing countries using a higher dosage in an attempt to improve its immunogenicity and efficacy.

Animals↗

Association of human herpesvirus 6 infection with exanthem subitum in Belem, Brazil.

Recent human herpesvirus 6 (HHV-6) infection was detected in cases of exanthem subitum (ES) involving four children, aged 10 to 24 months, between April and August 1994, in Belém, Brazil. By using the indirect immunofluorescence antibody assay (IFA), significant increases (at least eight times) in antibody concentrations were noted from the acute to the convalescent serum samples, with titers ranging from < 1:10/1:80 to < 1:10/1:640 (patients 3 and 2, respectively). All children had high fever (over 39 degrees C) for three days, followed by generalized, maculo-papular skin rash. A physical examination of the children also revealed concomitant, cervical lymph node swelling and tonsillar pharyngitis in two of them.

Antibodies, Viral↗

[Prospective study of rotavirus infections in Belém, Pará, Brazil: clinical and epidemiological features].

A prospective study of acute diarrhoeal diseases was carried out from April 1990 to September 1992 with the purpose of assessing the immunogenicity, safety and efficacy of a Rhesus-human reassortant rotavirus ("RRV-TV") vaccine, involving 540 children living in Belém, Pará, Brazil. As half of the children received placebo, this trial provided the opportunity of broadening the knowledge on both clinical and epidemiological aspects of rotavirus infection in the Amazon region. There were 2,789 diarrhoeal episodes during the above mentioned period, of which 86 (3.1%) associated with rotavirus; serotype 1 was the more prevalent, accounting for 67.9% of serotyped strains. Rates of 5.9 and 0.2 episodes of diarrhoea per child/year were noted for all cases and the rotavirus-related ones, respectively. This agent was the only pathogen found in 70.9% of the 86 rotavirus-related episodes of acute diarrhoea, whereas the most frequent associations involved Giardia intestinalis and enteropathogenic Escherichia coli, accounting for 7.0% and 11.6% of mixed infections,respectively. The monthly rates of rotavirus-related episodes of diarrhoea ranged from 0.8% to 9.6%, reaching the highest peaks during the dry months of the year. Means of clinical severity scores of 9.4 and 5.3 were recorded for the rotavirus-related episodes of diarrhoea and those of other aetiology, respectively.

Clinical Trial↗