Showing papers by "Universidade Federal de Pelotas published in 1997"

The role of conceptual frameworks in epidemiological analysis: a hierarchical approach.

Abstract: Background This paper discusses appropriate strategies for multivariate data analysis in epidemiological studies. Methods In studies where determinants of disease are sought, it is suggested that the complex hierarchical inter-relationships between these determinants are best managed through the use of conceptual frameworks. Failure to take these aspects into consideration is common in the epidemiological literature and leads to underestimation of the effects of distal determinants. Results An example of this analytical approach, which is not based purely on statistical associations, is given for assessing determinants of mortality due to diarrhoea in children. Conclusions Conceptual frameworks provide guidance for the use of multivariate techniques and aid the interpretation of their results in the light of social and biological knowledge.

Low birthweight, preterm births and intrauterine growth retardation in relation to maternal smoking.

Abstract: The association between the intensity and duration of cigarette smoking during pregnancy and the frequency of low birthweight, preterm births and intrauterine growth retardation was investigated in a historical cohort. All 5166 livebirths occurring in the city of Pelotas, Brazil, during 1993 were identified and mothers interviewed soon after delivery. Children whose mothers smoked during pregnancy had a birthweight 142 g lower than those of non-smoking mothers. The odds ratio for low birthweight among children of smokers was 1.59 [95% CI 1.30-1.95]. There was no association between smoking and preterm delivery assessed by the Dubowitz score. In relation to intrauterine growth retardation, smoking was associated with an odds ratio of 2.07 [95% CI 1.69-2.53]. There was a direct dose-response association between the number of cigarettes smoked and the risk of growth retardation. Women whose partner smoked were also at higher risk of having a child with growth retardation. All the above results were adjusted for confounding factors. The effect of maternal smoking on low birthweight seems to be attributable to intrauterine growth retardation rather than preterm delivery.

Pacifier Use and Short Breastfeeding Duration: Cause, Consequence, or Coincidence?

Abstract: Objectives. Pacifiers are related to a shorter duration of breastfeeding. However, it is unclear whether this association is causal, because confounding, reverse causality, and self-selection of mothers may play a role. These issues were investigated through a combination of epidemiologic and ethnographic research in southern Brazil. Methodology. A population-based cohort of 650 mothers and infants were visited shortly after delivery and at 1, 3, and 6 months. The rate of complete follow-up was 96.8%. A subsample of 80 mothers and infants was selected for the ethnographic study, which included in-depth interviews and participant observations in the age range of 2 to 6 months with a mean of 4.5 visits. Results. The epidemiologic study showed that pacifier use was common with 85% of users at 1 month. However, this was a dynamic process, with many infants starting or abandoning the pacifiers in any age range. Children who stopped breastfeeding in a given period were likely to take up the pacifier during that period. Further analyses excluded all infants not breastfed at 1 month of age and those who reportedly had breastfeeding problems, leaving 450 infants with full data. Intense pacifier users at 1 month (children who used the pacifiers during most of the day and at least until falling asleep) were four times more likely to stop breastfeeding by 6 months of age than nonusers. Users also had fewer daily breastfeedings than nonusers. After adjustment for several confounding variables, logistic regression showed that pacifier use was still associated with an odds ratio of 2.5 (95% confidence interval, 1.40 to 4.01) for stopping breastfeeding. The ethnographic analysis showed that pacifier use was widely regarded as a positive behavior and that mothers often strongly stimulated the infants to accept it. Although few mothers openly admitted that pacifiers might shorten breastfeeding, a considerable group effectively used pacifiers to get their infants off the breast or to increase the interval between feedings. The latter also had rigid breastfeeding styles that increased maternal-infant distance, had important concerns about objective aspects of infant growth and development, and were highly sensitive to infant crying. These behaviors were linked to intense comparison between themselves and other mothers and to a lack of self-confidence. Nonwhite mothers, those who delivered vaginally, and mothers of infant girls seemed to be more confident and less affected by these difficulties. The epidemiologic analysis confirmed that pacifier use was more closely associated with breastfeeding duration among nonwhite mothers and for normally delivered infants. Conclusions. Pacifiers may be an effective weaning mechanism used by mothers who have explicit or implicit difficulties in breastfeeding, but they are much less likely to affect infants whose mothers are confident about nursing. Breastfeeding promotion campaigns aimed specifically at reducing pacifier use will fail unless they also help women face the challenges of nursing and address their anxieties. The combination of epidemiologic and ethnographic methods was essential for understanding the complex relations between pacifier use and breastfeeding.

Prevalência de obesidade em adultos e seus fatores de risco

Abstract: INTRODUCAO: Foi realizado estudo transversal em uma amostra representativa da populacao adulta de Pelotas para determinar a prevalencia de obesidade e os fatores a ela associados, tendo em vista o acentuado aumento de excesso de peso no Brasil, entre 1974 e 1989 MATERIAL E METODO: Foram estudadas 1035 pessoas com idade entre 20 e 69 anos, residentes na zona urbana do municipio A obesidade foi definida a partir do indice de massa corporal (IMC) igual ou superior a 30 kg/m² A analise multivariada foi realizada considerando um modelo hierarquico das variaveis associadas com obesidade em ambos os sexos RESULTADOS: A prevalencia de obesidade foi de 21% (IC95% 18 - 23), sendo de 25% (IC95% 22 - 29) entre as mulheres e 15% (IC95% 12 - 18) entre os homens A relacao entre as variaveis socioeconomicas e a obesidade foi inversa entre as mulheres e direta entre os homens Entre as mulheres, as variaveis que se mantiveram associadas significativamente com obesidade foram: obesidade dos pais, ocorrencia de diabete ou hipertensao, nao fumar, menor numero de refeicoes diarias e nao ter realizado exercicio fisico no lazer durante o ultimo ano Para os homens somente a ocorrencia de obesidade nos pais e a hipertensao arterial sistemica estiveram significativamente associadas, enquanto a protecao do maior numero de refeicoes apresentou uma associacao quase significativa (p = 0,07) CONCLUSAO: Os resultados indicam que os determinantes de obesidade sao diferentes entre os sexos, ocorrendo em maior frequencia entre as mulheres e com o aumento da idade

Issues in the design and interpretation of studies to evaluate the impact of community-based interventions

Abstract: Increasingly, epidemiologists are faced with the need to evaluate the impact of an intervention that is delivered at the level of a community or cluster of individuals, rather than at the individual level. This has profound implications for the design and interpretation of a study to evaluate its impact. We start by discussing the issues arising in the extension of the randomized double-blind controlled trial methodology to the evaluation of interventions delivered to clusters of individuals, or to whole communities, where the unit of randomization is a cluster of individuals rather than an individual. We then consider alternative approaches to design, discuss their relative strengths and weaknesses and present a framework of design options. Finally we propose a pragmatic approach to evaluation design in this setting. We believe that the answer lies in the judicious selection of different design elements, combined in such a way that when the evidence from each is presented together, a clear picture of the impact of the intervention emerges. We illustrate this using an example from the recent literature.

Use of outpatient services in an urban area of Southern Brazil: place and frequency

Abstract: OBJETIVO: Estabelecer a utilizacao de servicos medicos ambulatoriais na Cidade de Pelotas, RS, Brasil METODOLOGIA: Foi feito estudo transversal amostral com base populacional Foram entrevistados 1657 adultos, durante os meses de marco e junho de 1992 As perdas amostrais totalizaram 9,7% Durante a analise utilizou-se duas variaveis dependentes: o tipo de servico de saude classificado quanto a natureza do lucro e a frequencia de consultas durante o ultimo ano RESULTADOS: Na analise verificou-se que o tipo de servico estava associado com variaveis sociais tais como classe social, propriamente dita, escolaridade e local de residencia A variavel frequencia de consultas relacionou-se com sexo feminino, fatores de risco e motivos de consultas CONCLUSAO: Concluiu-se que a escolha do tipo de servico de saude dependia de fatores ligados a classe social antes do que variaveis associadas a gravidade dos problemas de saude

Hospitalização por pneumonia: influência de fatores socioeconômicos e gestacionais em uma coorte de crianças no Sul do Brasil

Abstract: OBJETIVO: Investigar a influencia de fatores socioeconomicos e gestacionais sobre a hospitalizacao por pneumonia no periodo pos-neonatal. MATERIAL E METODO: Longitudinal. Criancas com idade entre 28 e 364 dias, nascidas na cidade de Pelotas, RS (Brasil), em 1993. A definicao de caso foi a permanencia em ambiente hospitalar por um periodo igual ou superior a 24 horas em consequencia de pneumonia. Foi aplicado delineamento longitudinal. RESULTADOS: Dentre as 5.304 criancas da coorte, 152 (2,9%) foram hospitalizadas por pneumonia no periodo. O valor preditivo positivo do diagnostico clinico comparado com o radiologico alcancou 76%. A analise atraves de regressao logistica mostrou que a classe social e a escolaridade materna estiveram forte e inversamente associadas a admissao hospitalar. Filhos de maes adolescentes tiveram risco duplicado a internacao; paridade igual ou superior a tres representou risco 2,8 vezes maior em relacao as maes primiparas; ganho de peso inferior a 10 kg durante a gestacao implicou risco cerca de 40% maior a hospitalizacao. CONCLUSOES: A classe social e a escolaridade materna foram os principais determinantes da hospitalizacao. Idade e paridade materna e o ganho de peso durante a gestacao foram tambem fatores de risco importantes.

How well is hypertension managed in the community? A population-based survey in a Brazilian city

Abstract: There is usually little information available on how well hypertensive individuals are managed at the community level. This survey measured the frequency of hypertension in a medium-sized Brazilian city by studying a cluster sample of 1657 adults aged 20-69 years. The 328 hypertensives (19.8%) answered a questionnaire on the knowledge and management of their condition. Two-thirds were aware of their status and more than half were on antihypertensive medication, but only one-third had their blood pressure under control. Physicians failed to advise a large proportion of their patients about the need to lose weight, take exercise, and quit smoking. Although laboratory tests were carried out in most patients, fundoscopy and chest X-rays were performed in fewer than 50%. Continued care by the same physician was the only factor significantly associated with compensated high blood pressure (relative risk for not having continued care = 1.35; 95% CI = 1.02-1.71). High levels of absenteeism, reduction of the work load, and early retirement were found among the individuals with high blood pressure.

Tabagismo em gestantes de área urbana da região Sul do Brasil: 1982 e 1993

Abstract: OBJETIVO: Avaliar as mudancas na prevalencia de tabagismo durante a gravidez na cidade de Pelotas, RS, Brasil, com base nos estudos da populacao materno-infantil realizados nos anos de 1982 e 1993. METODOLOGIA: Estudo transversal, tendo sido identificados 6.011 e 5.304 recem-nascidos, cujas familias residiam na area urbana da cidade de Pelotas, respectivamente em 1982 e 1993. RESULTADOS: O tabagismo materno durante a gestacao apresentou uma discreta reducao de 35,7%, em 1982, para 33,5% em 1993 (p < 0,05). O habito de fumar esteve inversamente relacionado com a renda e o numero de consultas no pre-natal.

Breast feeding, pacifier use and infant development at 12 months of age: a birth cohort study in Brazil.

Abstract: Many studies suggest that breast feeding confers developmental and intellectual advantages on children. In a recent study, however, no association was found between breast feeding and intelligence in adult life after adjustment for other variables, and the use of pacifier in infancy was the most important predictor of intelligence. We analysed the associations between breast-feeding duration, pacifier use and suspected developmental delay at 12 months of age in a birth cohort in Pelotas, southern Brazil. All 5304 hospital births occurring during 1993 were studied and a sample was followed up at 1, 3, 6 and 12 months of age. Breast-feeding practices and use of pacifiers were assessed at each visit, as well as suspected developmental delay, measured by the Denver II test. The prevalence of developmental delay was analysed, through logistic regression, according to breast-feeding status and pacifier use, accounting for the possible confounding effect of other variables. The prevalence of suspected developmental delay at 12 months was 34.1%, being slightly higher among children who used pacifiers at 6 months than among non-users (35.3% and 28.7% respectively). There was a marked negative association between breast-feeding duration and developmental delay, with children breast fed for 9 months or more presenting significantly less suspected developmental delay (25.5%) than those breast fed for less than 1 month (42.4%). The effects of multiple variables were tested, and only high parity, smoking during pregnancy, birthweight, gestational age, pacifier use and breast-feeding duration remained significantly associated with suspected developmental delay. The effect of pacifier use, however, disappeared after adjusting for breast-feeding duration, suggesting that breast feeding, and not pacifiers, affects child development.

Biaxial phases in polydisperse mean-field model solution of uniaxial micelles

Abstract: We consider a discretized Maier–Saupe model for a polydisperse solution of micelles of axial symmetry. An exact mean-field solution is presented. The phase diagram displays a biaxial phase at small average anisometries and finite dispersion in size, and two opposite uniaxial nematic phases for large average anisometries. Relations to the experimental phase diagram for ternary mixtures are discussed.

Resistência das plantas a moléstias fúngicas

Abstract: Plant resistance to fungic diseases is due to their genetic constitution and environmental factors. In breeding programs, one of the main objectives is to obtain high grainyield potenlial plants with resistance to the prevalent diseases. Knowledge of genetic basis of resistance is importam to increase selection efficiency and due to the wide variability of fungi there is the necessity of using different strategies to reduce the probability of pathogen estabtishment in crops.

Marcadores moleculares e sua aplicação no melhoramento genético de plantas

Abstract: Na implantacao de um programa de melhoramento, uma das principais necessidades do melhorista e a capacidade de identificar genotipos superiores em uma populacao segregante. O conhecimento das relacoes geneticas e a capacidade geral e especifica de combinacao entre os individuos e essencial para a selecao de genitores. Os marcadores geneticos poderao auxiliar na identificacao de individuos atraves de suas diferencas geneticas. Estes marcadores podem ser divididos em morfologicos e moleculares (enzimaticos e de DNA). Os marcadores de DNA como o RFLP e o RAPD poderao contribuir para incrementar a eficiencia do melhoramento de plantas atraves do mapeamento de especies de interesse e de caracteres agronomicos. Alem disto, diversos autores tem comprovado a sua eficiencia em caracterizar e agrupar genotipos diferentes de varias especies com bastante precisao.

Hyaline membrane disease (HMD) therapy in Latin America: impact of exogenous surfactant administration on newborn survival, morbidity and use of resources.

Abstract: Impact of surfactant administration, on neonatal mortality, morbidity and resource use, was assayed in a historically controlled study in 19 NICUs from 5 Latin American countries. Data from clinical records of infants with HMD were retrospectively reviewed for the previous 2 years (PRE phase n = 666 cases), and prospectively in cases that received surfactant (SURF phase, 348 cases). Birth weight stratified relative risk, with 95% confidence interval (RR +/-95% CI) for death, in the SURF as compared to the PRE was 0.60 (0.49-0.74), 0.79 (0.68-0.92) and 0.82 (0.71-0.94), for days 7, 28 and at discharge, respectively. At all ages mortality was significantly lower during SURF. Significant increases were observed in the occurrence of pulmonary interstitial emphysema, pulmonary hemorrhage, patent ductus arteriosus, bronchopulmonary dysplasia, intrahospital infection and necrotizing enterocolitis. Resource use increased significantly. It is concluded that the use of surfactant in the region is an important advance, and the efficacy of management of the late complications of the very premature and labile HMD survivors must increase. More attention should be given to thermal regulation, nutrition and management of infection in the survivors, before a more marked effect of surfactant can be seen.

Ocorrência de ixodidae parasitos de capivara (Hydrochoerus hydrochaeris linnaeus, 1766) na estação ecológica do Taim, Rio Grande - RS, Brasil

Abstract: The aim of this article was the identification ofthe tick species observed on capybara in wildlife in the Ecologic Area of Taim, Rio Grande - RS; Brazil. Twenly seven capybaras found dead by trample in the road BR 471 in the Ecologic Area, wereexamined ticks coilected of the species Amblyomma cooperi (= A. lutzi and = A. ypisilophorum), Amblyomma triste, Amblyomma tigrinum and ninphs of the Genus Amblyomma. Amblyomma cooperi represented 68.41% of the ticks with a frequency of parasitism of 92.60% of the hosts; Amblyomma triste species represented 24.75% of the collected ticks m 44.43% of the hosts; Amblyomma tigrinum species were coilected m 14.81% of the hosts from a total of 1.21% of the found ticks and, the nimphs of Amblyomma were coilected in 18.51% of the hosts per forming 5.63% of the ali ticks coilected. The relation mate .female showed values of 2.3:1 and 2:1 to A. cooperiand and A. triste, respectivety. All examined hosts were found wiih ticks, with a mean of 18.4 ticks per host.

As transformações no mundo do trabalho e a questão da saúde: algumas reflexões preliminares

Abstract: Neste artigo realizo algumas reflexoes preliminares sobre as transformacoes no mundo do trabalho e a saude. Para isto inicio o estudo colocando algumas dimensoes essenciais do trabalho como categoria central para analisar a sociedade, a partir da concepcao marxista. A seguir resgato nas transformacoes do mundo do trabalho a especificidade da saude refletindo sobre a questao do cuidado e da organizacao dos trabalhadores de saude.

OCORRÊNCIA DE Amblyomma fuscum NEUMANN, 1899 E Amblyomma humerale KOCH, 1844 (ACARI: IXODIDAE) EM Bufo arenalis NO ESTADO DE SÃO PAULO, BRASIL

Abstract: O objetivo deste trabalho e relatar a ocorrencia do parasitismo monoespecifico de A. fuscum NEUMANN, 1899 e A. humerale KOCH, 1844 em sapos (Bufo arenalis) no Municipio de Rosana, Estado de Sao Paulo, Brasil. Este relato caracteriza um novo hospedeiro e uma nova localizacao geografica para estas duas especies de carrapatos.

Plantas tóxicas para suínos

Abstract: Poisonous plants for swine in Brazil, Uruguay and Argentina are reviewed. Poisoning by seeds of Senna occidentalis, as a cause segmentar muscle necrosis, and by seeds of Aeschynomene sp., as a cause of symmetric focal degeneration in the white matter of the cerebellum, are described. Nefrosis due to Amaranthus spp., soft tissue calcification caused by Solanum malacoxylon, acute periacinar liver necrosis caused by Wedelia glauca and Xanthium spp., and nervous, digestive and muscular signs caused by the fruits of Melia azedarach, are also mentioned. The intoxication by Crotalaria spectabilis, studied experimentally in Brazil as a cause of chronic hepatitis, is also reveiwed.

Influência do ácido indolbutírico e ethefon no enraizamento de estacas de pessegueiro (Prunus persica (L.) Batsch)

Abstract: Este trabalho foi conduzido no Departamento de Fitotecnia da Faculdade de Agronomia Eliseu Maciel, Universidade Federal de Pelotas, em estufa com nebulizacao intermitente, com o objetivo de verificar o efeito do acido indolbutirico(AIB) e ethefon (acido 2-cloroetil fosfonico) no enraizamento de estacas de ramos de pessegueiro. Utilizou-se estacas medianas retiradas de ramos de plantas com seis anos de idade, da cultivar Diamante, com comprimento de 15cm. Efetuou-se duas lesoes laterais na base das estacas que foram tratadas com acido indolbutirico nas concentracoes 0; 1000; 2000 e 3000ppm, na forma liquida e, ethefon nas concentracoes de 0; 50; 100 e 150ppm. Apos a imersao de 5 segundos, acondicionou-se as estacas em sacos de polietileno contendo como substrato a mistura de areia+cinza (2:1 v/v). Pelos resultados obtidos concluiu-se que o acido indolbutirico aumentou o percentual de estacas realizadas ate a concentracao de 1752ppm. e o numero de raizes ate a concentracao de 1791ppm. O ethefon nao apresentou resultados significativos na forma e concentracao utilizadas.

ENRAIZAMENTO DE ESTACAS DE AMEIXEIRA (Prunus salicina Lindl) TRATADAS COM ÁCIDO INDOLBUTÍRICO E ETHEPHON

Abstract: Verificou-se a influencia do acido indolbutirico (AIB) e do ethephon (acido 2-cloroetil fosfonico) no enraizamento de estacas de ameixeira, cultivares Frontier, Reubennel, Ace, Songold, Roxa de Itaquera e Beauty. O experimento foi realizado em casa de vegetacao com nebulizacao intermitente, na Faculdade de Agronomia Eliseu Maciel, Universidade Federal de Pelotas, RS. O AIB foi usado na forma liquida, na concentracao de 3000ppm e o ethephon nas concentracoes 50; 100 e 150ppm, incluindo um tratamento testemunha, com imersao em agua destilada. O tempo de imersao foi de 5 segundos. As estacas foram retiradas da parte mediana, de ramos do ano, de plantas com 8 anos de idade, com cerca de 15cm de comprimento. Apos o tratamento, foram acondicionadas em sacos de polietileno contendo vermiculita como substrato. Os resultados obtidos mostraram que as cultivares de ameixeira possuem diferentes potenciais de enraizamento; a cultivar Frontier apresentou maior percentual de enraizamento, numero e peso da materia seca das raizes; a aplicacao de reguladores afetou somente o percentual de enraizamento da cultivar Reubennel, com tratamento de AIB a 3000ppm; os melhores resultados de numero e peso da materia seca das raizes foram obtidos com AIB a 3000ppm. O ethephon nao apresentou efeito entre seus tratamentos, em todas as variaveis analisadas, apresentando efeito menor que o AIB e maior que a testemunha apenas na cultivar Reubennel na variavel enraizamento de estacas.

Demyelination and remyelination after multiple intramedullary injections of ethidium bromide in Wistar rats

Abstract: The ethidium bromide model of demyelination has been employed to study the central nervous system response to several episodes of demyelination. Twenty-seven Wistar rats received 2 to 4 intraspinal injections of 1 microliter of either 0.1% ethidium bromide in normal saline (19 rats) or saline 0.9% (8 rats) in different anatomical locations. The intervals between the injections ranged from 28 to 42 days. Ten days after the last injection all the rats were perfused with 2.5% glutaraldehyde. The spinal sections were evaluated macroscopically and by light and transmission electron microscopy. The lesions were typical of focal primary demyelination with preserved vascular structures and followed by remyelinization and varied in size and histological aspects. After multiple sequential ethidium bromide injections, the central nervous system seems to modify its response capacity to an inflammatory challenge although there is no change in its pattern of remyelination.

[Populational study of investigation of perinatal and infant deaths: methodology, validity of diagnosis and under-registration].

Abstract: OBJECTIVE The main objectives of the present study were to evaluate the percentage of under-registration of infant mortality in 1993 and compare it with the ones found 1982; to analyze the agreement between the official death certificates and the ones made by the referees. METHODS The infant mortality of all children born in Pelotas, in 1993, was monitored through daily visits to hospitals, as it was done in 1982; monthly, cemeteries and public registration offices were visited to detect any deaths outside the hospitals. Besides the official death certificates, two independent referees established the underlying cause of death based on information from pediatricians, case-notes, autopsies and through a home visit to the parents of the children. RESULTS The percentage of under-registration fell substantially from 24%, in 1982, to 5.4%, in 1993. The agreement between the official death certificates and the ones made by the referees showed satisfactory Kappas, unless for ill defined diseases such as sudden infant death, where the agreement was null. CONCLUSIONS The authors conclude that there was a significant fell of the under-registration for infant death in Pelotas, and the ill defined causes such as sudden infant death have been hidden by the diagnosis of pneumonia.

Estudos histomorfométrico e histológico das lesões ósseas causadas por flúor em aves

Abstract: Sodium fluoride was administered in the water to 2 groups of 25 Shaver female poultry. Group A received fluoride from 1 to 120 days of age and group B from 61 to 120 days. Each group was divided into 5 treatments, with 5 chickens each, which received 0, 25, 50, 200, and 400 ppm of fluoride in the water, respectively. All animals were killed at 120 days of age. For histomorphometric studies the left femur and tibia were used, and for histologic studies the right femur and tibia. In the cortical bone, cortical porosity was slightly increased by fluoride, but the differences with the control group were not significant. Cortical thickness increased in the animals treated with fluoride (p<0,05, r2 = 0,59 ). In the trabecular bone, of group A, trabecular thickness (TT) (p<0,05, r2 = 0,63) and trabecular bone volume (TBV) (p<0,05, r2 = 0,72) increased in treatments receiving 25-200 ppm, and decreased in the 400 ppm treatment, as it was demonstrated by quadratic regression analysis. In group B there was a positive linear correlation on TT (p<0,05, r2 = 0,98) and TBV (p<0,05, r2 = 0,77) with fluoride ingestion.The osteoid surface was also positively correlated with the amount of fluoride ingested by the animals (p<0,001, r2 = 0,80). These results suggest that fluoride improves osteoblastic function resulting in increased osteoid production and bone apposition. In the other hand, in the animals treated with 400 ppm of fluoride for 120 days bone apposition was reduced suggesting a functional alteration of the osteoblasts or improved bone resorption. In the histological study of bone tissue all animals that received fluoride showed an increased trabecular thickness which was more marked in the 200-400 ppm treatments. In chickens treated with 200-400 ppm of fluoride osteoblasts and osteoclasts were more numerous suggesting an increased bone turnover. In cortical bone Haversian canals were narrowed on the periosteal surfaces and resorption spaces were enlarged on the endosteal surfaces.

ARRANJOS DE PLANTAS E ÉPOCAS DE SEMEADURA NO CULTIVO CONSORCIADO DE FEIJÃO (Phaseolus vulgaris L.) E MILHO (Zea mays L.) NA REGIÃO SUL DO RIO GRANDE DO SUL

Abstract: Desenvolveu-se este trabalho com o objetivo de propiciar alternativas de arranjos e epocas de semeadura do milho em sistemas consorciados de milho e feijao, procurando identificar aqueles de comprovada eficiencia biologica e rentabilidade economica, que pelas facilidades de manejo, favorecam e possibilitem a adocao dos consorcios pelos agricultores da regiao. O feijao foi semeado em uma unica epoca e o milho aos quatro (epoca 1) e dezenove dias (epoca 2) apos a emergencia do feijao nos arranjos formados por 1 linha de milho para 2 de feijao; 1 linha de milho para 3 de feijao; 2 linhas de milho para 3 de feijao; 2 linhas de milho para 4 de feijao; monocultivo de feijao e monocultivo de milho. Estudou-se a eficiencia biologica atraves da producao equivalente de milho e renda bruta em diferentes relacoes de precos entre as culturas, bem como, do indice de uso eficiente da terra (UET). A epoca de semeadura e a alteracao na distribuicao das plantas de milho interferiram no desempenho da mesma, modificando os componentes do rendimento e reduzindo a sua produtividade a indices que variaram de 41% a 69% na epoca 1 e de 88% a 93% na epoca 2, enquanto o feijao consorciado praticamente nao apresentou diferencas do monocultivo. Os arranjos formados por 1 linha de milho para 3 de feijao e 2 linhas para 3 de feijao foram os que mais se destacaram.

Implementação da seleção recorrente no melhoramento de plantas autógamas através da macho-esterilidade

Abstract: Os sistemas de melhoramento convencionais baseados no metodo genealogico, utilizados principalmente em cereais de estacao fria, determinam a reducao da variabilidade e da capacidade de recombinacao, devido a utilizacao de um numero de genitores limitado nos cruzamentos. O incremento da probabilidade de recombinacao atraves da selecao recorrente pelo aumento do numero de cruzamentos pode ser a saida para este problema. A utilizacao da macho-esterilidade representa uma alternativa viavel para propiciar o cruzamento natural em especies de autofecundacao, favorecendo a utilizacao da selecao recorrente como uma importante ferramenta para o melhoramento de plantas autogamas.

Low body weight: a simple indicator of the risk of dehydration among children with diarrhoea.

Abstract: The early identification of children at high risk of dehydration as a consequence of diarrhoea would be of great value for health care workers in developing countries. By comparing children aged less than two years with diarrhoea and moderate to severe dehydration with matched controls who had uncomplicated diarrhoea, a number of prognostic factors were assessed. Low body weight, regardless of age, was strongly associated with the risk of dehydration; using 7.0 kg as a cut-off, it had a sensitivity of 75% and a specificity of 68%. Low body weight was superior to more complex anthropometric indices, including weight for age, weight for length or length for age, and also to early signs and symptoms during the episode. By reflecting the effects of both young age and those of malnutrition, low body weight may prove to be a simple indicator for predicting dehydration among children with diarrhoea presenting at a health service.

Efeito sazonal sobre a natimortalidade e mortalidade de leitões até 21 dias de idade

Abstract: Birth records of 3032 piglets of the Large White breed, born during the period between 1984 and 1987 were sent for analyses by the Associacao Brasileira de Criadores de Suinos. The data used came from a commercial farm in the state of Rio Grande do Sul, Brazil. Natal mortality and mortality of piglets up to 21 days of age were determined in different season condition during three years of analysis. The effect of season on there parameters was significative. The larger number of stillbirths was observed in the spring (0.50 piglets) and fall (0.47 piglets) seasons. The higher percentage of preweaning mortality was observed in the winter (1.96 piglets/offsping) and in the summer (1.79 piglets/offspring) seasons.