[Buffer capacity of infant formulas diluted with different types of water].

Artificial feeding of infants under 1 year old deserves a special attention. It is generally accepted that the infant formula is approximated to the human milk and adapted to the infantile digestive system. Important properties of breast milk are pH and acid-based buffer capacity. According to this fact, the results of the experimental determination of pH and buffer properties of fresh, fermented, and anti-reflux infant formulas, diluted with water of different pH, have been presented. It was found that reconstituted fermented infant formulas has one unit pH less than the antireflux and fresh mixtures. When restoring infant formula with waters of different alkalinity, pH value changed slightly. Thus, pH of fresh and antireflux mixtures varied in the range 6.67±0.76, of fermented milk mixtures - 5.75±0.55. The buffer capacity with respect to acid of infant formulas play an important role in the nutrition of the child. It depends on the proteins (having different amino acid composition) comprising the milk mixture, and on the type of water, which is used for restoring. Restored infant formulas having a greater buffer capacity for acid can reduce infant gastric acidity. Six of submitted infant formula reconstituted with children bottled water "Nutrilak AQUA", "HiPP" and "Arhyzik" observed the lowest values of the buffer capacity (9.00±3.00 mmol/l). The larger value of the buffer capacity by acid (>12.00 mmol/l)) was observed in formulas reconstituted with boiled tap water and children bottled water "Agusha" and "FrutoNyanya".

Experimental infection of capybaras Hydrochoerus hydrochaeris by Rickettsia rickettsii and evaluation of the transmission of the infection to ticks Amblyomma cajennense.

The present study evaluated the infection of capybaras (Hydrochoerus hydrochaeris) by Rickettsia rickettsii and their role as amplifier hosts for horizontal transmission of R. rickettsii to Amblyomma cajennense ticks. Two groups of two capybaras each were evaluated: on day 0, group 1 (G1) was infested by R. rickettsii-infected ticks, and group 2 (G2) was inoculated intraperitoneally with R. rickettsii. Two additional groups were control groups, not exposed to R. rickettsii, being CG1 group the control of G1, and CG2 group the control of G2. Capybara rectal temperature was measured daily. Blood samples were collected every 3 days during 30 days, and used to (i) inoculate guinea pigs intraperitoneally; (ii) DNA extraction followed by real-time PCR targeting the rickettsial gene gltA; (iii) hematology; (iv) detection of R. rickettsii-reactive antibodies by indirect immunofluorescence assay (IFA). Blood was also collected from G1 capybaras every approximately 10-30 days till the 146th day, to be tested by serology. Capybaras were infested by uninfected A. cajennense nymphs from the 3rd to the 18th day. Engorged nymphs were collected, allowed to molt to adults in an incubator. Thereafter, the subsequent flat ticks were tested by PCR. All G1 and G2 capybaras became infected by R. rickettsii, as demonstrated by guinea pig inoculation and seroconversion, but they showed no fever. Rickettsemia was continually detected from the 6th (G2 capybaras) or 9th (G1 capybaras) to the 18th day post inoculation or infestation with R. rickettsii-infected ticks. A total of 20-25% and 30-35% of the flat ticks previously fed on G1 and G2 capybaras, respectively, became infected by R. rickettsii. The study demonstrated that R. rickettsii was capable to infect capybaras without causing clinical illness, inducing rickettsemia capable to cause infection in guinea pigs and ticks. Our results indicate that capybaras act as amplifier host of R. rickettsii for A. cajennense ticks in Brazil.

[Anthropophilic activity of Aedes aegypti and of Aedes albopictus in area under control and surveillance]. / Atividade antropofílica de Aedes aegypti e Aedes albopictus em área sob controle e vigilância.

OBJECTIVE: To describe the hematophagous activity of Ae. aegypti and Ae. albopictus in an area under control and surveillance. METHODS: The study was conducted during 18 months, from April, 1993 to October, 1994, in Cosmopolis, Sao Paulo state, Brazil. Human baits were used to collect mosquitoes. The number of females captured is presented monthly by area of the city and local in the household. The rainfall was measured and indices are presented without model adjustment. RESULTS: The presence of females of both species was observed in 83% (Ae albopictus) and 61% (Ae. aegypti) of the period studied. The months of January, February and March presented the highest rates of activity for females of both species, with Ae. albopictus being more frequently captured than Ae. aegypti. Both species were captured in central and peripheral areas of the city, during the day from 9 to 12 am and from 4 to 7 pm. By a Poisson regression, it was observed that Ae. albopictus females were more frequently captured in the peri-housed area, in an independent way considering the area of the city. CONCLUSIONS: It has been identified difference on the hematophagous activity only for Ae. albopictus, being of importance the outside area of the house.

Atividade antropofílica de Aedes aegypti e Aedes albopictus em área sob controle e vigilância / Anthropophilic activity of Aedes aegypti and of Aedes albopictus in area under control and surveillance

OBJETIVO: Descrever a atividade de hematofagia de Aedes aegypti e Aedes albopictus em área submetida ao controle e à vigilância entomológica. MÉTODOS: O estudo foi realizado de abril de 1993 a setembro de 1994, na cidade de Cosmópolis, Estado de São Paulo. Utilizou-se isca humana para coleta dos exemplares. Calculou-se o número médio mensal de fêmeas capturadas por domicílio segundo as áreas central e periférica do município e os locais intra e peridomiciliar. Apresenta-se o índice pluviométrico mensal sem ajuste de modelo. RESULTADOS: Observou-se a presença de fêmeas das espécies em 83 por cento (Ae. albopictus) e 61 por cento (Ae. aegypti) do período estudado. Os meses de janeiro, fevereiro e março apresentaram maior atividade de fêmeas para as duas espécies, com maior presença de Ae. albopictus do que de Ae. aegypti. Os exemplares foram capturados na área central e periférica da cidade, nos períodos matutino, das 9:00 às 12:00 e crepuscular vespertino, das 16:00 às 19:00. Com utilização de modelo de regressão de Poisson, observou-se que fêmeas de Ae. albopictus foram mais capturadas no peridomicílio, independente se área central ou periférica. CONCLUSÕES: Foi detectada diferença no perfil de atividade da hematofagia somente para o Ae. albopictus, sendo de relevância o peridomicílio.

Triatoma infestans em área sob vigilância entomológica para doença de Chagas, Estado de Säo Paulo, Brasil / Triatoma infestans in area under entomological surveillance for Chagas'diseases in Säo Paulo State, Brazil

Atendendo a notificação de encontro, por habitantes da Fazenda Paraíso, área rural do Município de Paulínea, Estado de São Paulo, de um exemplar alado de triatomíneo, procedeu-se a uma investigaçao epidemiológica em que capturaram-se 109 exemplares de triatoma infestans em focos situados em construçoes peridomiciliares. As condiçóes locais favoreciam a colonizaçao por triatomíneos: grande número de construçoes peridomiciliares abandonadas, habitadas por pombos e pardais, fornecedores de farto alimento para os hemípteros. Eliminaram-se os focos por meio de controle mecânico dos ninhos dos pássaros. Borrifaram-se, com inseticida de ação residual todas as unidades domiciliares da regiao. Desde que persistam as condições para a instalacao de focos de triatomíneos nessa localidade, é obrigatória a implementaçao de açoes de vigilancia. Entretanto, os indicadores entomológicos e sorológicos sugerem nao ser preocupante a situaçao atual. Destaca-se aqui a importância da notificação triatomínica para a detecçao de focos de triatomíneos, particularmente os de Triatoma infestans

[Morphological and morphogenetic characteristics of erysipelas inflammation]. / Morfologicheskie i morfogeneticheskie osobennosti rozhistogo vospaleniia.

Literature information on morphology and morphogenesis of erysipelas inflammation is analysed in the light of macroscopic, microscopic and histochemical data. Alterations of the epidermis and derma (epidermocytes, fibroblasts, macrophages, plasmocytes and labrocytes) in the foci of inflammation are described in detail. Deficiency of the local mechanisms plays a leading role in chronization of the disease. A pathogenetic role of circulating and tissue associated immune complexes is shown. It is claimed that further study of skin parenchymatous and stromal component and their interaction in both focus of inflammation and outside of it may help in revealing specific parts of erysipelas inflammation pathogenesis.

Aspectos eco-epidemiológicos da leishmaniose tegumentar americana no Município de Campinas / Eco-epidemiological aspects of American cutaneous leishmaniasis in the Municipality of Campinas, Säo Paulo, Brazil

Descreve um surto de leishmaniose tegumentar americana ocorrido no período de fevereiro de 1993 a setembro de 1994, nos Distritos de Sousas e Joaquim Egídio, município de Campinas, SP. Ocorreram 25 casos, sete na área rural, nove na área peri-urbana e nove na urbana. Verifica uma mobilidade da ocorrência dos casos em direçäo rural-urbana. Em relaçäo ao sexo, houve predomínio do masculino (60 por cento) sobre o feminino (40 por cento), com 44 por cento dos casos concentrados na faixa etária de 11 a 30 anos. Quanto à ocupaçäo, 48 por cento correspondem a estudantes, empregadas domésticas e donas-de-casa. Em 92 por cento dos casos, a doença manifestou-se com lesäo única, predominantemente localizadas nos membros inferiores e superiores. O surgimento desses casos na área está provavelmente associado à expansäo urbana ocorrida nas décadas de 70-80 e acelerada mais recentemente.

Lateral patterns of the neural cell adhesion molecule on the surface of hippocampal cells developing in vitro.

In monolayer cultures of hippocampal neurons from newborn rats, an immunocytochemical quantitative study was carried out to investigate age-dependent arrangement of the neural cell adhesion molecules in different parts of cell membranes. On the fifth and 12th day in vitro, neural cell adhesion molecules were labelled with specific antibodies and protein A conjugated to colloidal gold particles. Samples of randomly selected electron micrographs that displayed labelled membrane fragments of cell bodies, growth cones, and axons were numerically analysed for the five- and 12-day in vitro neurons. Neural cell adhesion molecules surface topography was quantitatively described and compared, using a statistical stereological approach. The mean surface density of labelled neural cell adhesion molecules was found to be approximately 2.5 times higher in growth cone membranes relative to somatic and axonal membranes in five-day in vitro neurons. By the 12th day in vitro, this density decreases in somatic membranes (approximately 18%) and increases in axonal membranes (approximately 60%). Representative spectra of lateral intervals between labels as well as images that show typical topography of label on membrane surfaces were simulated. The results revealed regular patterns of neural cell adhesion molecules on the somatic surface and allowed consideration of neural cell adhesion molecules arrangement in a view of membrane adhesion properties. Participation of cytoskeleton in neural cell adhesion molecules rearrangement is discussed.

Changes in the neural cell adhesion molecule patterns on the rat glial cell surfaces with development and contact formation in vitro.

In monolayer cultures of newborn rat hippocampal cells, immunogold-labelling at the electron microscope level was used to study quantitatively the neural cell adhesion molecule (N-CAM) arrangement on the surface of glial soma and processes on 5 and 12 days in vitro (DIV). Four corresponding samples of micrographs were formed. To quantify the labelling, a stochastic geometry approach was used. Spectra of lateral distances between labels as well as simulated images of the surface label arrangement (invisible in micrographs) were derived and compared. The data show that, on both 5 and 12 DIV, N-CAM density on the surface of processes is approximately 2 times higher than that in somata; 12-DIV cells showing a lower (approximately 25%) N-CAM surface density as compared with the 5-DIV cells. This suggests that N-CAM expression in glia surfaces decreases while the cells form contacts, and N-CAM sorting between soma and processes remains stable. The simulated topographies of the lateral N-CAM arrangement might highlight fundamental mechanisms that underlie formation of the neural network.

Blocking effect of intraperitoneal injection of phenylalanine on high-threshold calcium currents in rat hippocampal neurones.

Calcium currents were recorded in cultured (5-7 days) hippocampal neurones isolated from one-day-old rats. The animals obtained intraperitoneal injections of L-phenylalanine which induces in the brain biochemical changes characteristic of phenylketonuria. It has been found that the amplitude of the low-threshold calcium current in L-phenylalanine-affected neurones was not appreciably changed compared with that in neurones from control (non-injected) animals. However, the amplitude of the high-threshold calcium current was essentially decreased. Its relative amplitude at Vt = +20 mV became 40 +/- 30% as contrasted to 416 +/- 130% in neurones from control animals (the amplitude of the calcium currents at Vt = -10 mV taken as 100%). The decrease remained during the whole time of culturing. Addition of L-tyrosine to the cultivation medium (50 microM) restored the high-voltage calcium current, its relative amplitude reaching 280 +/- 57%. The data are discussed in conjunction with the previously obtained results about antagonistic modulatory action of tyrosine and phenylalanine on the functioning of high-threshold calcium channels and possible mechanisms of brain dysfunction during phenylketonuria.

[Inhibition of the high-threshold calcium current in hippocampal neurons of rats subjected to intraperitoneal injection of phenylalanine]. / Podavlenie vysokoporogovogo kal'tsievogo toka v neironakh gippokampa krys, podvergnutykh intraperitonal'noi in"ektsii fenilalanina.

Effect of intraperitoneal injection of phenylalanine on the calcium current of hippocampal neurons of rats has been studied by the voltage clamp method of the whole-cell recordings. Calcium currents in hippocampal neurons of control animals after 5-7 days in culture can be separated into two components: low and high voltage-activated ones. The value of high voltage-activated calcium current was 69 +/- 13% at Vt = -10 mV from total calcium inward current in these neurons. High voltage-activated Ica in neurons of phenylalaninemic rats was significantly depressed and its value was 32 +/- 14%, the Vt value being the same. Low voltage-activated calcium current was resistant to intraperitoneal injection of L-phenylalanine.

[Restoration of the potential-dependent L-phenylalanine-inhibited calcium current by L-tyrosine in cultured hippocampal neurons]. / Vosstanovlenie L-tirozinom potentsialozavisimogo kal'tsievogo toka, podavlennogo L-fenilalaninom, v kul'tiviruemykh neironakh gippokampa.

Calcium currents were recorded in cultured (5-7 days) hippocampal neurons isolated from one-day rats. The animals were intraperitoneally injected L-phenylalanine which induced in their brain biochemical changes typical of phenylketonuria. It has been found that in neurons from injected animals the amplitude of the high-threshold calcium current was substantially inhibited and amounted to 40 +/- 30% at Vt = +20 mV (amplitude of calcium currents at Vt = -10 mV taken as 100%). Addition of L-tyrosine to the cultivation medium (50 mumol/l) restored the high-voltage calcium current, its relative amplitude reaching 280 +/- 57%.