Sleeping position, breastfeeding, bedsharing and passive smoking in 3-month-old Swedish infants.

Parents of 1028 infants who attended community-based infant health clinics were interviewed concerning infant sleeping position, feeding habits, bedsharing and passive smoking at 3 months of postnatal age. In addition, they were asked to state which source of information had mainly influenced them in the choice of the sleeping position. Fifteen per cent of the infants were regularly laid to sleep in the prone position, compared with 72% (1991) before official guidelines concerning infant sleeping position were issued. The overall prevalence of exclusive breastfeeding was 70.4%. Prevalence of maternal smoking was 17.9% and 22.8% of the infants were regularly bedsharing with the parents. Those mothers who did not comply with official recommendations regarding infant sleeping position were also less likely to follow other recommendations concerning infant care practices. Prone sleeping infants were more likely to be formula fed and exposed to passive smoking, and hence associated with additional risk factors for sudden infant death syndrome.

Immunoglobulin E in the feces of children and adolescents from some tropical and subtropical countries.

Eighteen of 27 individuals, aged from 6 months to 19 years (mean 5 years, 7 months), from countries in the tropics or the subtropics had either intestinal parasitic infestations or intestinal enteropathogenic bacterial infections or both. Fourteen of those with intestinal pathogens had detectable concentrations of IgE in their fecal extracts, ranging from less than 0.5 to 420 IU/ml extract (mean 33 IU/ml). This rate of occurrence was significantly higher than the number of IgE-positive fecal extracts in a group of 54 healthy nonallergic Norwegian children (p less than 0.001), but did not differ from that of a group of 40 allergic children (p greater than 0.20). The individuals with intestinal helminthic infection had the highest fecal IgE concentrations. Of the 9 individuals who did not have any demonstrable intestinal pathogen, low concentrations of IgE could be detected in feces from only 2, which did not differ from the rate in the healthy Norwegian controls. The concentrations of IgE in the feces of the subjects from tropical/subtropical regions correlated linearly with the corresponding serum concentrations of IgE (r = 0.69; p less than 0.001). The results indicate that the combined load of intestinal pathogens, including helminths, protozoa, and enteropathogenic bacteria, may stimulate IgE production in the gut.

Changes in myoglobin and lactate dehydrogenase in muscle tissues of a diving bird, the Pigeon Guillemot, during maturation.

1. The concentration of myoglobin (Mb) and the isozymic distribution and activity of lactate dehydrogenase (LDH) in heart and pectoralis muscle were investigated at three stages of maturation of the Pigeon Guillemot, Cepphus columba. 2. Mb is not detectable in chick pectoralis; it is present in fledgling pectoralis muscle and increases four-fold in adult pectoralis. Mb concentration in heart muscle is similar in chick and fledgling and doubles in the adult. 3. LDH activities in pectoralis muscle of fledgling and adult increase to about three times that of the chick. LDH activities in heart of chick, fledgling and adult are similar to one another. 4. All five isozymes of LDH are present in both heart and pectoralis muscle at all stages; the heart muscle shows predominantly LDH-1 isozyme, and the pectoralis, LDH-5. The relative amounts of the five isozymes in the heart extract were constant during maturation but pectoralis LDH isozymes changed during maturation towards a more even distribution of the five isozymes in the adult. 5. Changes in Mb and LDH in the Pigeon Guillemot correlate with the animal's maturation from a sedentary nest sitter to an active diver and flyer. The adult pectoralis muscle probably has both aerobic function for wing-propelled short dives and flying and anaerobic capacity for longer dives.