This work proposes a serial quantitative analysis of the numbers and percentages of B and T cell subsets in 104 consecutive premature infants (PI) between birth and six months of age as compared with 21 normal term infants. First, in order to ascertain the effects of perinatal distress at birth (respiratory distress, neonatal asphyxia) on certain parameters of the immune system, the PI were divided into two groups. One comprised 36 healthy preterms, the other, 68 preterms with perinatal distress. It was then shown that healthy PI differed from full-term infants by their higher absolute numbers of T cells (CD2-positive) and helper T cell subset (CD4-positive). These increases in CD2- and CD4-positive cells correlated with gestational age (GA). An increase in B lymphocytes (CD20-positive cells) was also documented but no correlation with GA could be seen. Secondly, perinatal distress was found to be concomitant with transient decrease in percentages and absolute numbers of CD2- and CD4-positive cells, particularly in PI of less than 28 weeks of gestation. The B cells (CD20- and CD21-positive cells) were not different in absolute numbers. Respiratory distress had a more discernable effect than fetal asphyxia on the immune system. Finally, no immunological parameters tested could at any time predict the occurrence of infection in PI during the first 6 months of life.

Antigens, CD↗

PubMedDate not supplied

Pumpless respiratory assistance using a membrane oxygenator as an artificial placenta: a preliminary study in newborn and preterm lambs.

Newborns suffering from severe respiratory difficulties and not responding to conventional methods have been successfully treated by extracorporeal circulation with a membrane oxygenator (ECMO). However, the technique needs a highly specialized staff, excellent laboratory support, and continuous surveillance of the procedure to prevent complications. In a series of experiments on newborn and preterm lambs, we have investigated a relatively simpler technique of respiratory support that involves a pumpless arteriovenous bypass by cannulating both umbilical arteries and the umbilical vein. A highly efficient microporous membrane oxygenator (MO) with very low resistance was selected. This type of perfusion that mimics the placental circulation, besides providing an additional amount of oxygen to the blood, has proven to be very effective for CO2 extraction. Before its application in humans, however, improvements in the catheters to be inserted in the umbilical vessels, some modifications in the design of the MO, and improvements in the blood compatibility of all foreign surfaces in contact with blood are needed.

Animals↗

PubMedDate not supplied

[Risperidone and edema: apropos of a case].

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Adult↗