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Biomedical subjects

J C Pereira

Publications and source records attributed to J C Pereira.

At least 19 recordsLinked to original sources
PubMed2000

Adaptive estimation of residue signal for voice pathology diagnosis.

The use of noninvasive techniques to evaluate the larynx and vocal tract helps the speech specialists to perform accurate diagnose of diseases. In this study, a method to distinguish among 21 different pathologies using speech signals was developed. Through inverse filtering (Kalman and Wiener filters) of the voice signal, the residue was estimated and seven acoustic features were extracted from it to evaluate the laryngeal diseases. As time-invariant inverse filtering was used, the nonstationary nature of dysphonic voices was also considered. Together with the estimation of the acoustic features using a robust statistical method, this technique also allowed us to discriminate among pathologies with very close perceptual characteristics. The results from a Mann-Whitney test indicated that the best measurement for pathological discrimination was JITTER with 54.79% ability to cluster the voice types and the worst one was spectral flatness of residue (SFR) with 36.41%.

Acoustics↗
PubMed1999

Evaluation of four mathematical functions to describe scrotal circumference maturation in Nellore bulls.

Four functions to characterize scrotal circumference (SC) growth in Nellore bulls were compared to identify which was the most suitable for biological interpretation. Nellore bulls (n = 532), born between September and December of 1992 to 1994 were used in the study. Measurements were made on fixed dates in January, April, July and October of each year. At the time of SC measurements, the ages of the bulls ranged from 200 to 1300 d. The functions used to describe the data were: Brody, SC = A (1 - B exp -kt); Logistic, SC = A/(1 + B exp -kt); Gompertz, SC = A exp(-B exp -kt) and Richards SC = A (1 + B exp -kt)m, where SC is the scrotal circumference at t days of age, A is the estimated SC at maturity, B is the integration constant established by the initial values of SC and t, k is the maturity constant, which equals the ratio between the maximum rate of growth and SC at maturity; m is the inflection point parameter for Richards function, which did not converge. The Brody, Gompertz and Logistic functions fitted the data in a similar fashion, with similar values for the statistics EMS and R2, and they reached convergence with similar computational costs. The Logistic function presented the best pattern of average prediction error, and therefore, it was selected for biological interpretation. For the Logistic function, estimated SC at maturity (A) was 37.95 cm at 72 mo of age. The maturity index (k) was .11 cm, and the inflection point (time of maximum growth) was reached at 13.09 mo of age at an average SC of 18.97 cm.

Aging↗
PubMed1999

Integrated orthodontic and restorative procedures for replacement of lost central incisors.

UNLABELLED: The use of adhesive material in association with many clinical procedures has contributed a great deal to solving functional and esthetic problems. Before adhesive techniques were known, dental procedures were more invasive and aggressive, especially in young patients. This article describes some integrated clinical procedures used to esthetically and functionally restore a mouth with traumatic loss of both central incisors. The treatment involved the orthodontic mesialization of the upper teeth toward the midline followed by anatomic and functional recovery through restorative dentistry. CLINICAL SIGNIFICANCE: This article describes some integrated clinical procedures that may effectively and conservatively improve the esthetic and functional results when a young patient loses the central incisors.

Child↗
PubMed1999

Assessing morbidity in the paediatric community.

INTRODUCTION: Morbidity information is easily available from medical records but its scope is limited to the population attended by the health services. Information on the prevalence of diseases requires community surveys, which are not always feasible. These two sources of information represent two alternative assessments of disease occurrence, namely demand morbidity and perceived morbidity. The present study was conceived so as to elicit a potential relationship between them so that the former could be used in the absence of the latter. METHODS: A community of 13,365 families on the outskirts of S. Paulo, Brazil, was studied during the period from 15/Nov/1994 to 15/Jan/1995. Data regarding children less than 5 years old were collected from a household survey and from the 2 basic health units in the area. Prevalence of diseases was ascertained from perceived morbidity and compared to estimates computed from demand morbidity. RESULTS: Data analysis distinguished 2 age groups, infants less than 1 year old and children 1 to less than 5. The most important groups of diseases were respiratory diseases, diarrhoea, skin problems and infectious & parasitical diseases. Basic health units presented a better coverage for infants. Though disease frequencies were not different within or outside these units, a better coverage was found for diarrhoea and infectious & parasitical diseases in the infant group, and for diarrhoea in the older age group. Equivalence between the two types of morbidity was found to be limited to the infant group and concerned only the best covered diseases. The odds of a disease being seen at the health service should be of at least 4:10 to ensure this equivalence. CONCLUSION: It was concluded that, provided that health service coverage is good, demand morbidity can be taken as a reliable estimate of community morbidity.

Ambulatory Care↗
PubMed1998

The importance of clinical symptoms and signs in the diagnosis of community-acquired pneumonia.

A sample of 153 children was drawn from a teaching hospital in Säo Paulo, Brazil. It comprised 51 pneumonia cases and equal number of non-respiratory and healthy controls matched by age and sex. Age ranged from 1 month to 7 years. They were all submitted to a standard protocol to investigate clinical symptoms and signs, and diagnosis of pneumonia was supported by X-ray images. Univariate data analysis contrasting pneumonia and non-pneumonia subjects suggested that the best pneumonia indicators would be chest auscultation, history of breathlessness, history of cough, chest in-drawing and fast respiratory rate, in descending order. A multivariate approach including also data from X-ray investigation was then tried with the application of multiple discriminant analysis to study the separation of pneumonia cases, non-respiratory patients and healthy children. It revealed that when many items of information are considered the performance of individual symptoms and signs change. The best predictors of pneumonia were then identified as chest in-drawing, chest auscultation, X-ray, history of breathlessness and toxaemia. Clinical symptoms taken all together contribute more than signs and equal X-ray in importance. Accordingly, it is concluded that any attention to X-ray should be secondary to clinical investigation, and it is suggested that the WHO's guidelines could profit with the inclusion of at least one clinical symptom, namely history of breathlessness which was found more useful than the WHO recommended breath count.

Analysis of Variance↗
PubMed1997

Susceptibility of asthmatic children to respiratory infection.

OBJECTIVE: A case-control study of patients with pneumonia was conducted to investigate whether wheezing diseases could be a risk factor. METHODS: A random sample was taken from a general university hospital in S. Paulo City between March and August 1994 comprising 51 cases of pneumonia paired by age and sex to 51 non-respiratory controls and 51 healthy controls. Data collection was carried out by two senior paediatricians. Diagnoses of pneumonia and presence of wheezing disease were independently established by each paediatrician for both cases and controls. Pneumonia was radiologically confirmed and repeatability of information on wheezing diseases was measured. Logistic regression analysis was used to identify risk factors. RESULTS: Wheezing diseases, interpreted as proxies of asthma, were found to be an important risk factor for pneumonia with an odds ratio of 7.07 (95% CI = 2.34-21.36), when the effects of bedroom crowding (odds ratio = 1.49 per person, 95% CI = 0.95-2.32) and of low family income (odds ratio = 5.59 against high family income, 95% CI = 1.38-22.63) were controlled. The risk of pneumonia attributable to wheezing diseases is tentatively calculated at 51.42%. CONCLUSION: It is concluded that at practice level asthmatics should deserve proper surveillance for infection and that at public health level pneumonia incidence could be reduced if current World Health Organisation's guidelines were reviewed as to include comprehensive care for this illness.

Asthma↗
PubMed1997

[Defining priorities for the management of health science and technology].

INTRODUCTION: An urgent need for the management of science and technology production in the health field has been recognised in Brazil since 1994, when the Federal Government called a National Conference on the subject. The present study presents a methodology for the identification of items of priority in planning such management. MATERIAL AND METHOD: A survey was conducted in the research institutes belonging to the S. Paulo State Health Department among a sample of research professionals with a view to collecting data on two different scenarios: present and expected situation. Eighteen concepts, assembled in four different groups, were assessed is terms of an average percentage approval or disapproval, for each scenario. Consistency for the measurement of each of these groups was examined by the use of Cronbach's alpha coefficient and inconsistent concepts were disregarded in the analysis. The average percentage of approval/disapproval was further calculated as scenario co-ordinates for each concept and institute entering the study so that priority maps for concepts and institutes could be constructed. RESULTS: Results suggest that the present situation meets with disapproval, though not strongly so, while a high degree of expectation is expressed with significant emphasis as regards research infrastructure management. The main priorities are given as: acknowledgement of performance, support for publication, resource allocation by research project and methodological advice for research analysis. CONCLUSION: It is concluded that the study methodology was helpful in eliciting management priorities and could be applied elsewhere with due adjustment of content regarding selection of concept and their grouping.

Academies and Institutes↗
PubMed1995

[Assessment of strategies of science and technology management: a case study].

The Health Department of the State of S. Paulo has implemented a management strategy on research and development (R&D) for its research institutes which comprises three different items: 1) project registration, 2) support and 3) promotion of R&D activities. The present study explores the ability of this R&D management system to provide information and evaluates the performance of the third item which has been responsible for the assignment of research grants to professionals whose projects are selected through a peer review. The assessment of the grant's distribution was conducted by comparing the mean scientific production recorded in literature data bases for grant holders and equal an number of controls matched by institute of origin. The ability of the system to produce information was studied by the application of Cluster Analysis. The results show that grant holders have a scientific production significantly higher than their controls. Concerning information production, it is shown that proper raw data processing may render suggestions for decision making and that the institutes may be grouped in clusters of those that adopt similar management strategies.

Academies and Institutes↗
PubMed1995

Intradural cervical chordoma without bone involvement. Case report.

The authors report a unique case of cervical chordoma in a 37-year-old woman without radiological evidence of bone involvement that was found to be totally intradural at surgery. Chordomas that are entirely extrasseous and intradural are extremely rare and in most of the cases described are located near the clivus. This is the first reported case of an intraspinal intradural chordoma.

Adult↗
PubMed1994

Association between air pollution and mortality due to respiratory diseases in children in São Paulo, Brazil: a preliminary report.

This work presents the results of a time series study relating air pollution and respiratory mortality in children under 5 years of age in the metropolitan area of São Paulo, Brazil. Daily records of mortality (excluding neonatal mortality) for the period May 1990 to April 1991 were collected along with daily records of relative humidity, temperature, SO2, CO, particulates (PM10), O3, and NOx concentrations. Using multiple regression methods we demonstrated a significant association between mortality due to respiratory diseases and the NOx levels. After controlling for weather and season effects, the odds of dying due to respiratory diseases, considering the mean levels of NOx in São Paulo, was estimated at 1.3 (+/- 0.13). This result is in accord with previous animal studies conducted by our group and indicates that air pollution in São Paulo has reached levels high enough to have adverse health effects on the exposed population.

Air Pollution↗
PubMed1993

[Arterial hypertension and possible risk factors].

The results of a cross-sectional (prevalence) study of high blood pressure, carried out in 1987 in Araraquara County in the north of S. Paulo State, Brazil are presented. The group studies numbered 1,199 people, including 533 men and 666 women, of from 15 to 74 years of age. The results show a high prevalence of the disease (32.0% for men and 25.3% for women), with a tendency to increase with age, up to the 40's (men) and the 50's (women). There was also a greater percentage of hypertensives in the mulatto and black groups, in the obese, and among those of lower family income, with a lower level of schooling and with less well remunerated jobs. However, the logistic regression showed very small odds ratios associated with these risk factors, which could be attributed to the way these factors were considered.

Adolescent↗
PubMed1992

Assessment of a strategy for the control of respiratory diseases in children.

A programme for the control of respiratory diseases in children was conceived for the State of S. Paulo, Brazil, in 1986. Its progress thereafter and the epidemiology of the diseases concerned are examined. Apart from an inquiry into the 64 existing State local health authorities, a sample of 18,255 cases of children assisted by the programme at different levels, including both in-patient and outpatient care, is analysed. Each case record included information about identification (child, doctor and health facility), reasons for calling, diagnoses made and outcome of treatment. Further data were also sought from hospitals and from State mortality records. The programme was found to be poorly implemented in the State but, where implemented, it showed itself capable of resolving problems (only 0.5% of the cases could not be handled) as also of changing ongoing trends (more than 50% reduction in hospital admission rates). Individual assessment of each item of the programme indicated its bottlenecks. Regarding the epidemiology of respiratory diseases, it is observed that the major burden to health services comes from children aged less than five, and that the most important diseases are wheezing illnesses and pneumonia. Moreover, they were found to be significantly associated (p = 0.000) so that a child in the community presenting wheezing diseases is 5 times more likely to develop pneumonia than a child with any other respiratory diagnosis. Similarly, among the under five deaths it was found that the risk for pneumonia is 3 times greater for children who died presenting wheezing diseases than it is for children with any other sort of diagnosis. In conclusion, the programme is deemed to be efficient and effective but its efficacy is marred by administrative flaws. The successful control of respiratory problems in childhood is related to a proper appreciation of the importance of wheezing diseases.

Brazil↗
PubMed1991

Distribution of 137Cs in soils due to the Goiânia accident and decisions for remedial action during the recovery phase.

In September 1987, a powder radioactive source was removed from a teletherapy machine in Goiânia, Brazil. Subsequently, it was ruptured in a residential garden causing the dissemination of 137Cs throughout the city. Soil resuspension processes and burial of contaminated house waste in unused gardens were the major contributors to the Cs dissemination in soils at the secondary contaminated sites. Only locations within a radius of 50 m from the primary contaminated sites presented the need for remedial action. The radiation dose-rate measurements and the soil profiles were good indicators of the extent of the secondary contamination and were fundamental for the decisions taken regarding decontamination procedures. In cases of surface contamination, 60% on average of the total activity remained in the upper 1.5-cm layer over the first 5 mo after the accident, and topsoil removal proved to be an effective procedure for decontamination.

Accidents↗
PubMed1991

Cesium-137 in the Goiânia waterways during and after the radiological accident.

The main contamination areas in Goiânia were exposed soil surfaces, and with the first rainfalls, 137Cs quickly reached the Meia-Ponte River, the main local waterway. Regular measurements of bottom sediment, surface water, and fish were begun 3 wk after the accident. In the first survey, 137Cs was detectable in sediments up to 12 km downstream from the accident area. Maximum 137Cs concentrations found in sediments of the Meia-Ponte River were 1.3 kBq kg-1 dry weight and 200 Bq kg-1 fresh weight for fish. Cesium-137 was always less than 10 Bq L-1 in surface waters plus suspended particulates, even in the most contaminated creeks. Because it was the beginning of the rainy season, downstream sediment transport was enhanced. This resulted in a decrease of 137Cs concentrations in sediments of the urban area by a factor of approximately 20, 5 wk after the accident. The main sedimentation area for suspended sediments in this portion of the river is the Rochedo Reservoir, which is 80 km downstream from the accident area. In a survey performed 10 mo after the accident, 137Cs concentrations in the reservoir were up to 14 Bq kg-1 for fish, 1 Bq kg-1 for aquatic plants, and 100 Bq kg-1 dry weight for bottom sediments.

Accidents↗
PubMed1990

Assessment and prediction of asthma and its severity in the pediatric community.

Seventy four asthmatic children aged 7 to 11 years were examined along with controls matched by age and sex. Clinical and laboratory investigations preceded a 28-day follow-up where data about morning and evening peak expiratory flow rate (PEF), symptoms and treatment were recorded. The coefficient of variation of PEF was found to be an objective measurement of asthma severity that has statistically significant correlation with both symptoms (rs = .36) and treatment (rs = .60). Moreover, it separates mild and severe asthmatics, as confirmed by statistically significant differences (p = .008 or less) in symptoms, treatment, skin allergy and airways response to exercise. Skin allergy and airways responsiveness to exercise were found to be predictors of both disease and severity. By means of logistic regression analysis it was possible to establish the probabilities for both asthma and severe asthma when children presenting and not presenting these characteristics are compared. One single positive skin test represent a probability of 88% for the development of asthma and a probability of 70% for severe disease. A PEF reduction of 10% after an exercise test implies a probability of 73% for disease and a probability of 64% for severe disease. Increases in these variables imply geometrically increased risks and their presence together have a multiplicative effect in the final risk.

Asthma↗
PubMed1990

The engine or the caboose: health policy in developing countries.

A discussion of health policy in developing countries is presented. It argues that developing countries must adopt a progressive approach to health policy which rejects the two-tiered system of public and private health care. However, it also points out that ideology is not sufficient to maintain support. A progressive health system must utilize administrative and social and behavioral sciences to achieve effectiveness and efficiency in health care delivery. It cannot ignore these goals any more than a private health care system can.

Delivery of Health Care↗
PubMed1990

Clinical evaluation of Dycal under amalgam restorations.

Sixty-eight clinical amalgam restorations were removed to examine the consistency of the calcium hydroxide bases. The variation of the base consistency was influenced by the age and/or clinical profile of teeth and the status of the restorations. The clinical conditions affected the calcium hydroxide base consistency.

Calcium Hydroxide↗