José Ferreira de Carvalho

Aleitamento materno e a prática de desmame em duas comunidades rurais de Piracicaba - SP

Breast feeding and weaning were studied in 76 infants from 3 to 24 months of age in two rural communities in Piracicaba, state of Sao Paulo. Interviews with the childrens mothers were conducted at their homes. The average duration of exclusive breast feeding, predominant breast feeding (including only water and tea) and complementary feeding was analyzed by means of life tables. The Wilcoxon test was conducted to verify socioeconomic and demographic variables associated with the duration of breast feeding. The average duration of exclusive breast feeding was 3 days in the community of Anhumas and 30 days in that of Santa Olimpia. Predominant breast feeding and complementary feeding were prolonged for 90 and 180 days in Anhumas and for 120 and 165 days in Santa Olimpia, respectively. Only the sex of the child was associated with the duration of predominant breast feeding, with boys being nursed longer. Insufficient milk was the main reason given for termination of breast feeding. Weaning was generally initiated with liquids such as water, tea, fluid cow milk and sweetened juices.

Relação entre a patogenicidade de Schistosoma mansoni em camundongos e a susceptibilidade do molusco vetor: I. Infecciosidade das cercárias e carga de vermes

Foram pesquisadas as possiveis influencias que os mecanismos imunes do molusco poderiam exercer no desenvolvimento dos esporocistos e no comportamento do verme adulto no hospedeiro vertebrado. Utilizaram-se duas linhagens de S. mansoni (BH e SJ), selecionadas para o carater susceptibilidade e mantidas, respectivamente, em Biomphalaria glabrata e Biomphalaria tenagophila, seus hospedeiros invertebrados naturais. Formaram-se grupos experimentais de camundongos infectados com cercarias oriundas de moluscos das duas especies, pertencentes as geracoes P, F1, F2, F3 e F4. Foram calculadas as taxas de infeccao dos moluscos, numero de cercarias penetrantes e o numero de esquistossomos adultos nos roedores. Concluiu-se que a maior susceptibilidade de B. tenagophila determinou maior capacidade das cercarias em se tornarem vermes adultos. A maior susceptibilidade de B. glabrata originou maior capacidade de penetracao das cercarias.

Alguns dados referentes ao estudo parasitológico e anatomopatológico de duas linhagens de Schistosoma mansoni Sambon, 1907

Foi estudada a acao patogenica das linhagens de Schistosoma mansoni dos municipios de Belo Horizonte, MG e de Sao Jose dos Campos, SP (Brasil) observando maior capacidade patogenica da linhagem do primeiro, nas condicoes da experiencia.

Relação entre a patogenicidade do Schistosoma mansoni em camundongos e a susceptibilidade do molusco vetor: III. Mortalidade, pesos corporal e das vísceras

Estudou-se a relacao entre o desenvolvimento da hepatomegalia, da esplenomegalia, peso corporal e taxa de mortalidade em camundongos experimentalmente infectados por Schistosoma mansoni com o grau de susceptibilidade de Biomphalaria glahrata e B. tenagophila nas quais se desenvolveram as cercarias infectantes respectivamente, das linhagens BH e SJ. Foram utilizados como hospedeiro definitivo camundongos Swiss, SPF e como hospedeiros intermediarios populacoes de moluscos selecionados geneticamente para o carater susceptibilidade. Foram observados menores pesos corporais e das visceras em camundongos infectados com cercarias provenientes de moluscos que apresentaram elevado grau de susceptibilidade. A maior susceptibilidade dos moluscos a infeccao pelo S. mansoni correspondeu a uma menor sobrevivencia dos camundongos infectados. Os resultados fazem crer que a maior adaptacao do parasita ao hospedeiro intermediario, traduzidos pelas taxas mais elevadas de susceptibilidade, pode levar a um comportamento diferente deste parasita no hospedeiro definitivo.

Verification of the antagonism between larvae of Schistosoma mansoni and those of other Digenea in Biomphalaria tenagophila, a planorbid molusc from a natural breeding ground in the region of Campinas, SP, Brazil

Foi observado o comportamento de larvas de S. mansoni em moluscos previa e naturalmente infectados por larvas de outros Digenea. Foi verificado que as larvas de S. mansoni nao se desenvolveram nos moluscos previamente infectados com purcocercarias longifurcadas com ocelos ou com furcocercarias longifurcadas sem ocelos. Observou-se resistencia parcial ao desenvolvimento de S. mansoni nos moluscos previamente infectados por equinostomocercarias ou por distomocercarias com aculeo. A ausencia de reacao amebocitaria em torno dos esporocistos de S. mansoni nos moluscos infectados por outros digeneticos parece indicar a nao participacao dos amebocitos na resistencia oferecida ao desenvolvimento das larvas de S. mansoni.Foi observado o comportamento de larvas de S. mansoni em moluscos previa e naturalmente infectados por larvas de outros Digenea. Foi verificado que as larvas de S. mansoni nao se desenvolveram nos moluscos previamente infectados com purcocercarias longifurcadas com ocelos ou com furcocercarias longifurcadas sem ocelos. Observou-se resistencia parcial ao desenvolvimento de S. mansoni nos moluscos previamente infectados por equinostomocercarias ou por distomocercarias com aculeo. A ausencia de reacao amebocitaria em torno dos esporocistos de S. mansoni nos moluscos infectados por outros digeneticos parece indicar a nao participacao dos amebocitos na resistencia oferecida ao desenvolvimento das larvas de S. mansoni.

The epidemiology and control of schistosomiasis mansoni where Biomphalaria tenagophila is the snail host

Desde 1980, esta-se estudando a epidemiologia e o controle da esquistossomose mansonica no Municipio de Pedro de Toledo (Estado de Sao Paulo, Brasil). Em 1980 a prevalencia avaliada por exame de fezes (metodo de Kato-Katz) foi de 22,8%. Estatisticamente, ao nivel de 5%, nao houve diferenca nas prevalencias observadas nas zonas rural e urbana. A intensidade de infeccao foi baixa (media geometrica de 58,5 ovos por grama de fezes). As maiores prevalencias e intensidades de infeccao foram registradas na faixa etaria de 5 a 29 anos. Geralmente a transmissao da endemia verificou-se durante o lazer. Apenas 0,4% de B. tenagophila mostraram-se positivos para cercarias de S. mansoni. A maioria dos portadores era assintomatico. O programa de controle foi intensificado apos avaliacao dos dados de 1980, resultando em diminuicao acentuada da prevalencia de 22,8% em 1980 para 6%. Esta prevalencia residual vem se mantendo ate 1987. Agora iniciamos estudos para investigar as possiveis causas dessa prevalencia residual.

Atração de miracídios de Schistosoma mansoni por hospedeiros invertebrados: comportamento de miracídios frente a girinos de Hyla fuscovaria

Miracidia tropism to suitable hosts is a subject of much controversy. In this work, we try to determine the possible specificity of Schistosoma mansoni miracidia attraction and also the degree of this specificity. To this end an experiment was carried out to determine the probability of attraction in a given experimental set up, to H. fuscovaria girina or to one of two susceptible snail species. Two strains of S. mansoni were employed and also the corresponding snail species. A specially designed apparatus consisting of two circular glass chambers joined by an open channel was used. One of the girina or a snail was placed in one of the chambers (randomly chosen). In the channel a known number of miracidia were deposited and the count of miracidia in each of the three compartments (the two chambers and the channel) was recorded. The experiment was carried out under strong or subdued lighting. Statistical and ad-hoc exploratory data analysis have shown that: a) the miracidia, when exposed to only one species of snail, show more attraction to the sympatric snail host; b)one strain of miraciadia showed more attraction under strong lighting; the other strain behaved the opposite way, with stronger attraction under weak liht; c) the girina did not attract the miracidia; this seems to imply that sone chemiotropism is present in this phenomenon.Analisou-se a atracao de miracidios de Schistosoma mansoni das linhagens BH e SJ frente a seus vetores simpatricos e alopatricos tendo-se em consideracao a possibilidade da presenca de substâncias quimiotaxicas emanadas dos moluscos. Estudou-se tambem o comportamento desses miracidios frente a girinos de Hyla fuscovaria. Foi verificado que houve atracao dos miracidios pelos moluscos vetores e que essa atracao foi mais evidente quando a larva era colocada frente ao seu hospedeiro simpatrico.As observacoes realizadas no decorrer da experiencia demonstraram a presenca de substâncias miraxonais emanadas pelos moluscos.

Relação entre a patogenicidade do Schistoma mansoni em camundongos e a susceptibilidade do molusco vetor: II. Número de ovos nas fezes e número e tamanho dos granulomas nas vísceras

The influence of the susceptibility of the vector snails of S. mansoni on the development of the pathogenicity of the worm to the host was studied. Off-spring of snails Biomphalaria glabrata and Biomphalaria tenagophila were used, selected with regard to the susceptibility to S. mansoni of the strains BH and SJ trait, respectively. Parenteral, F1,F2, F3 and F4 generation cercariae were used for the infection of Swiss mice, which were killed eight weeks after infection. The number of eggs in the feces and the number of granulomas in the liver, spleen and intestines were counted. The size of the granulomatous reactions was evaluated. The results led to the conclusion that greater susceptibility of B. tenagophila was associated with a larger egg production in the feces and a higher density of granulomas in the liver. There is a clear inverse relationship between the area of hepatic, spleenic and intestinal granulomas and the rate of infection of the snails which served as intermediate hosts for the S. mansoni.The influence of the susceptibility of the vector snails of S. mansoni on the development of the pathogenicity of the worm to the host was studied. Off-spring of snails Biomphalaria glabrata and Biomphalaria tenagophila were used, selected with regard to the susceptibility to S. mansoni of the strains BH and SJ trait, respectively. Parenteral, F1, F2, F3 and F4 generation cercariae were used for the infection of Swiss mice, which were killed eight weeks after infection. The number of eggs in the feces and the number of granulomas in the liver, spleen and intestines were counted. The size of the granulomatous reactions was evaluated. The results led to the conclusion that greater susceptibility of B. tenagophila was associated with a larger egg production in the feces and a higher density of granulomas in the liver. There is a clear inverse relationship between the area of hepatic, splenic and intestinal granulomas and the rate of infection of the snails which served as intermediate hosts for the S. mansoni.

Esquistossomose mansônica em camundongos experimentalmente subnutridos

Mansoni schistosomiasis was studied in mice fed on a low protein diet. Four groups of the Swiss breed Mus musculus were used in an experiment with two factors, each with two levels: 1-non-infected, normal diet; 2 - infected, normal diet ; 3 - non-infected, low protein diet; 4 - infected, low protein diet. The mice were killed for observation at age 90 days, after 60 days of infection, for those infected. It was found that the worms suffered the effects of malnutrition, mainly males, whose population count was cut by half, in addition to poor individual growth. The hepatic granuloma count was found to be smaller in the undernourished group; while the corresponding lesions were also generally smaller. There was a marked leukopenia in the malnourished mice, even more so in the infected mice. The severe lymphopenia and eosinopenia observed suggest that the immunologic system of the host was affected by malnutrition. Mortality rates were far larger in the infected, low protein diet group. One may then surmise that the malnourished mice offered lower resistance to the infection, their lower number of granuloma notwithstanding.

Sobre o comportamento de duas linhagens de Schistosoma mansoni Sambon 1907: proposição para método de estudo quantitativo

After the commentaries made of host parasitic relations, the authors suggest method for the study of two strains of Schistosoma mansoni. With the rnethod proposed and its experimental use, the authors concluded. For both strains of S. mansoni, the average number of adult worms found m the host was 60 days after infection correlating positively with the number of cercarme whirh the host were exposed to. For both strains there was a positive correlation between the number of adult parasites found in the hosts 60 days after infection and the number of liver granuloma of the same hosts. For both the Belo Horizonte strain as to the Sao Jose dos Campos strain, a negative correlation was found between the number of liver granuloma and the average percentage of host survival. Over a certain number of adult parasites present, there was a significant percentual number of granuloma on the infected mice with the Belo Horizonte strain. Within limits there was a smaller significant percentual survivat of mice infected with the Belo Horizonte strain. For the same number of granuloma, survivat was not significantly different between infected host, by one or the other strain, therefore it is suggested that the hypothesis most likely, is that the pathogenecity of the Belo Horizonte strain results from larger number of granuloma per adult female present. Within the limits established for the host survival index and number of parasites, the band of the degree of pathogenecity ab keeps within close limit of each other for the two strains. Although for the Sao Jose dos Campos strain the number os parasites after the experiment was significantly greater, concluding that a smaller number of Beto Horizonte worms caused on the mice used in the experience, similar levels of pathogenecity and mortality, than a larger number of Sao Jose dos Campos worms.