Red blood cell membrane storage lesion

Storage of human erythrocytes in CPD produced a lesion of the erythrocyte membrane manifested by abnormal endocytosis in resealed ghosts and in intact erythrocytes. Endocytosis produced by resealing Ca, Mg, and ATP into ghosts was impaired by five weeks of storage and this defect was promptly reversed by the prior regeneration of ATP in the stored erythrocytes. Drug-induced endocytosis was studied in intact stored erythrocytes. Vinblastine endocytosis was not affected by storage. Chlorpromazine endocytosis was not affected by storage. Chlorpromazine endocytosis was variably but never completely inhibited by storage. Chlorpromazine endocytosis was variably but never completely inhibited by storage, and restoration of ATP occasionally resulted in complete restoration of chlorpromazine endocytosis to base line values. However, primaquine endocytosis was usually totally inhibited after three to four weeks of storage at a time when residual ATP levels were 30 to 50 per cent of base line values. Restoration of ATP levels to at least base line values did not completely primaquine endocytosis to control values. Study of primaquine endocytosis provides an opportunity for defining an erythrocyte membrane storage lesion.     

Heart rate variations in five-month-old children during interactions in a controlled environment

This paper reports the first data of a study on heart rate variations of 13 5-mo-old infants seated in special chairs. Their electrocardiograms and behaviour were continuously recorded during sessions that were set up with their mother and a mother-child dyad that they met for the first time when the first session was organized. The protocol comprised two interaction phases between the infants and their mothers and two with one another. The same pairs of mother-child dyads were studied a second time 1 wk later. During the first session, the infants' heart rate variability increased significantly from the mother-infant interaction phases to the infant-infant interaction phases. During the second session, the variability was higher during the mother-infant phases than in the corresponding phases of the first session. This could be linked to changes in the mothers' behaviour and the infants' idea and excitement of meeting the child from the first session again. However, the variability was significantly lower during the infant-infant phases than during the mother-infant phases and the corresponding infant-infant phases of the first session. This corresponds to the development of affiliative behaviours in the infants. Conclusion : When two 5-mo-old infants were seated by their mothers in special chairs, significant differences were observed in their heart rate variability when they became familiar with each other, whether they were interacting with their mothers or with one another.