Endothelin B receptors on vascular smooth muscle cells of the human umbilical vein mediate vasoconstriction.

Objective: To test the hypothesis that smooth muscle cells of the human umbilical vein have vasoconstricting endothelin B (ETB) receptors.

Methods: In strip preparations of human umbilical veins isometric tension after exposure to the selective ETB receptor agonist sarafotoxin S6c (S6c) was compared to the tension before S6c exposure (set as 100%).

Results: In intact preparations S6c induced vasoconstriction only at the highest concentration applied (10(-8)M; 149.

Anterior choroid plexus cysts: distinction from germinolysis by high-resolution sonography.

Background: The aim of the present paper was to develop criteria identifying anterior choroid plexus cysts (ACPC) and distinguish these from germinolytic pseudocysts.

Methods: Cerebral sonography was performed in 2200 neonates with mean gestational age 40 completed weeks (range 23-42 weeks) and mean birthweight of 3450 g (range 340-4610 g). In the last 300 neonates cystic formations in the caudothalamic groove were studied prospectively using a high-resolution ultrasound system with linear scanhead, and the previous results were re-evaluated.

Homology-directed recombination in IgH variable region genes from human neonates, infants and adults: implications for junctional diversity.

Homology-directed recombination, i.e. the preferential joining of gene segments at short sequence homologies, is found in 80% of IgH variable region genes from neonatal mice and causes a marked uniformity of their VH-DH- and DH-JH-junctions, which are predominated by one to three junctional sequences.

Prostanoids contribute to the oxygen-dependent regulation of vascular tone of human umbilical vein.

Aim: To investigate the contribution of prostanoids to the oxygen-dependent regulation of human umbilical vein vascular tone.

Methods: Intracellular membrane potential and isometric tension of intact and endothelium-denuded human umbilical vein strips with and without cyclooxygenase inhibition by indomethacin (10(-5) M) were recorded simultaneously during variation of the local pO2.

Results: Decreasing pO2 from 39 to 5 mm Hg resulted in hyperpolarization and decrease in isometric tension of intact preparations.

Oral glucose before venepuncture relieves neonates of pain, but stress is still evidenced by increase in oxygen consumption, energy expenditure, and heart rate.

Oral glucose was recommended as pain therapy during venepuncture in neonates. It is unclear whether this intervention reduces excess oxygen consumption (o(2)), energy loss, or cardiovascular destabilization associated with venepuncture, and whether <2 mL glucose solution is effective. We tested the hypothesis that oral glucose solution attenuates the increases in neonatal oxygen consumption, energy expenditure (EE), and heart rate associated with venepuncture for two different volumes of glucose solution (2 and 0.

Locally released norepinephrine in the oxygen-dependent regulation of vascular tone of human umbilical vein.

In a previous study, human umbilical vein preparations constricted at PO(2) values above the physiologic intrauterine PO(2) range and dilated at hypoxia. Denudation of the endothelium reversed the hypoxic vasodilatation only, suggesting the release of a nonendothelial vasoconstrictor. We therefore hypothesized that norepinephrine from adrenergic nerve terminals could be responsible for the observed constricting effects.

Nitric oxide and endothelin in oxygen-dependent regulation of vascular tone of human umbilical vein.

We investigated the possible contribution of nitric oxide (NO) and endothelin (ET) to oxygen-dependent regulation of human umbilical vein vascular tone by simultaneous registration of intracellular membrane potential and isometric tension of vessel strips with and without NO synthase inhibition [10-4 M N omega-nitro-L-arginine methyl ester (L-NAME)], ETA receptor blockade (10(-5) M BQ-123), or ETB receptor blockade (10(-7) M BQ-788) at Po2 values in the bath solution between 5 and 104 mmHg. Increasing PO2 above the physiological intrauterine range resulted in depolarization and an increase of isometric tension, whereas lowering PO2 resulted in hyperpolarization and a decrease in isometric tension. Removal of the endothelium reversed these effects.

Impaired CD14-dependent and independent response of polymorphonuclear leukocytes in preterm infants.

Unlabelled: Preterm newborn infants are especially susceptible to Gram-negative sepsis that is associated with a lethality of up to 40%.

Aims: We tested whether polymorphonuclear leukocytes (PMN) from preterm infants exhibit an impaired antibacterial response upon stimulation with lipopolysaccharide (LPS) from Escherichia coli when compared to full term newborns or adults.

Methods: We studied the effect of LPS on the expression of the surface proteins CD11b and CD14 and the secretion of elastase by PMN from preterm infants, term infants and adults ex vivo.

Longitudinal study of energy expenditure in preterm neonates <30 weeks' gestation during the first three postnatal weeks.

Objectives: The objective of this study was to measure energy expenditure (EE) in a contemporary population of preterm neonates <30 weeks' gestation.

Study Design: Prospective longitudinal cohort study in 26 consecutive preterm neonates (gestational age, 27 weeks [23-29] [median, range]; birth weight, 980 g [554-1592]). EE was measured by indirect calorimetry on postnatal days 1, 3, 5, 10, and 21.

Digoxin-like immunoreactive substance in nonoliguric hyperkalemia of the premature infant.

Nonoliguric hyperkalemia of premature infants probably results from a transient inhibition of membrane-bound Na+/K+-ATPase during the first 24 h after birth. We hypothesized that the endogenous digitalis-like activity of the serum of premature infants, which inhibits the Na+/K+-ATPase, triggered hyperkalemia. Serum concentrations of potassium ([K+]) and of the digoxin-like immunoreactive substance ([DLIS]) were measured during the first 24 h after birth in 60 infants including 30 infants <30 gestational weeks.

Pulmonary re-occurrence of post-transplant lymphoproliferative disease with hypogammaglobulinaemia.

Unlabelled: We report the case of a 12-year-old boy, who developed Epstein-Barr virus (EBV) associated post-transplant lymphoproliferative disease (PTLD) 7 years after renal transplantation. He responded well to the reduced immunosuppressive therapy and treatment with ganciclovir. Two years later he developed severe pneumonia and hypogammaglobulinaemia related to EBV infection exacerbation.

Pathogenesis and therapy of non-oliguric hyperkalaemia of the premature infant.

Non-oliguric hyperkalaemia is a common and serious complication of extreme prematurity, resulting from a potassium loss from the intra- into the extracellular space during a specific post-natal period. Treatment of this disorder has been adapted from the treatment of hyperkalaemia in renal failure, an entity of completely different pathophysiology. A few years ago, the administration of salbutamol, which induces cellular potassium uptake, was proposed as a new therapeutic option.

Diversification of Ig heavy chain genes in human preterm neonates prematurely exposed to environmental antigens.

Preterm neonates are exposed to extrauterine environmental Ags during the time period that corresponds to the last trimester of normal intrauterine development. To study whether this precocious exposure to Ags accelerates the Ig repertoire diversification, we compared IgH chain genes of preterm neonates (gestational age, 25-29 wk) during their first postnatal months with those of term neonates. Preterm infants approaching their expected date of delivery after 8-13 wk of extrauterine life used a similar V(H), D(H), and J(H) gene segment repertoire as term neonates born after intrauterine development.

Complement activation by in vivo neonatal and in vitro extracorporeal membrane oxygenation.

Complment activation during extracorporeal membrane oxygenation (ECMO) in newborns can be caused by both the underlying disease processes and by blood contact with the ECMO circuit. We investigated the relative importance of these mechanisms by measuring C3a, C5a and sC5b-9 before, during and after neonatal ECMO in six consecutive newborn patients using enzyme-linked immunoassay. In addition complement activation during in vitro ECMO with repeated flow of the same blood volume was measured using blood from healthy adult donors.