Neutralizing activity and secretory IgA antibodies reactive with rotavirus SA-11 (serotype G3) in colostrum and milk from Brazilian women.

BACKGROUND: Rotavirus is an important aetiological agent for severe diarrhoea in infants and young children worldwide. Anti-rotavirus antibodies in human colostrum and milk may interfere with rotavirus vaccination seroconversion. AIMS: To verify the presence of anti-rotavirus secretory IgA antibodies (SIgA) and the neutralizing capacity of 30 colostrum and 30 milk samples from Brazilian women in two different centres and analyze their persistence throughout lactation. METHODS: Colostrum and milk samples from healthy nursing mothers were tested for the presence of anti-rotavirus SIgA using conventional ELISA and their capacity to neutralize rotavirus using MA-104 cell cultures. Total IgA concentrations and anti-rotavirus SIgA levels were measured in samples collected from three mothers during 90 or 240 days of the lactation period. RESULTS: Colostrum samples showed higher levels of anti-rotavirus SIgA and higher neutralizing ability than in milk. However, these antibodies levels were not statistically different. In addition, there was no correlation between antibody levels and the neutralizing activity observed in colostrum and milk samples. Follow-up of three mothers demonstrated the persistence of anti-rotavirus and total IgA levels throughout lactation. CONCLUSIONS: These results support the encouragement of breastfeeding as a mechanism of protection against rotavirus infection in lactating infants. Components other than SIgA antibodies might play an important role in virus neutralization.

Red cell enzymes and intermediates in AGA term newborns, AGA preterm newborns and SGA term newborns.

Red cell enzyme activities and 2,3-diphosphoglycerate and adenosine-triphosphate levels in cord blood of three groups of newborn infants were studied. The groups were classified according to birthweight in relation to intrauterine growth and gestational age. Only phosphofructokinase, glyceraldehyde-3-phosphate dehydrogenase and enolase activity values differed significantly among the groups. The activity of phosphofructokinase was lower in small-for-date term infants (TSGA) and preterm adequate for gestational age (PTAGA) in comparison to term infants adequate for gestational age (TAGA). Glyceraldehyde-3-phosphate dehydrogenase activity was higher in TAGA, in comparison to PTAGA, with no other difference among the groups. Enolase activity was found to be higher in TSGA compared to TAGA and higher in PTAGA compared to TAGA. No differences were found between PTAGA and TSGA.

[Premature rupture of membranes and its relation to infection in newborn infants]. / Rotura prematura de membranas e sua relação com infecção no recém-nascido.

The authors made a retrospective analysis of 136 cases of premature rupture of membranes (RPM) to check for the presence of neonatal infection, anoxia, and prematurity according to the latency period between rupture of membranes and parturition. Neonatal infection due to RPM has been the cause of 8.8% of clinically and laboratorily confirmed cases; in 6.6% of the cases, laboratorial confirmation was not possible. Neonatal infection was not influenced by the latency period between RPM and parturition. Maternal symptoms of infection were more frequent in the group with latency period longer than 24 hours and there was a significant relationship between maternal infection symptoms and neonatal symptoms. Prematurity and anoxia were detected in 20% of the cases, but no relation to RPM was observed.

[Duration of breast feeding in an urban area of São Paulo, Brazil]. / Duração do aleitamento materno em uma área urbana de São Paulo, Brasil.

Duration of breast-feeding was studied by the authors among a representative sample of families with children under one year of age that resided in the area of coverage of the Health Center-School Samuel B. Pessoa in the borough of Butantã, São Paulo. The data was obtained by means of home interviews in which respondents were questioned about what type of food the child was eating that day, so that they did not have to depend on memory. The median duration of breast-feeding was found to be 2.8 months (84 days), thus showing that in the area under study early weaning is still practiced. Nevertheless, the study confirms the trend observed in the city of São Paulo in the last few years of a return to breast-feeding. This conclusion is supported by the fact that, contrary to the pattern in the previous decade, longer duration of breast-feeding is associated with higher academic levels of the parents (both), i.e., the practice is on the increase among the higher social and economic segments of the population. The study shows that the father can play a significant role in breast-feeding patterns. No correlation was found between breast-feeding duration and number of siblings, per capita monthly income, academic level of the mother, or the regularity of health check-ups.