Heart rate variability in preterm brain-injured and very-low-birth-weight infants.

Heart rate variability (HRV) reflects the complex interplay of the sympathetic and parasympathetic innervation of the heart. Developmental maturation of the fetus and newborn results in predictable alterations in the neural cardiac control of heart rate. Furthermore, patterns of HRV are closely correlated to clinical outcome in several pathologic situations.

Prenatal cocaine exposure reduces glial cell line-derived neurotrophic factor (GDNF) in the striatum and the carotid body of the rat: implications for DA neurodevelopment.

Glial cell line-derived neurotrophic factor (GDNF) is a glycosylated, disulfide-bonded homodimer, and a member of the transforming growth factor-beta superfamily. GDNF has been shown to promote the survival and morphological differentiation of dopamine (DA) neurons and increase their high-affinity dopamine uptake. In order to determine whether the mechanism for our previously observed cocaine-induced DA reductions in brain and carotid body were GDNF-mediated, we exposed Sprague-Dawley rat fetuses to cocaine via maternal subcutaneous injections (30 mg/kg b.

Atherosclerotic aortic gangliosides enhance integrin-mediated platelet adhesion to collagen.

Gangliosides, sialic acid-containing glycosphingolipids, accumulate in atherosclerotic vessels. Their role in the pathogenesis of atherosclerosis is unknown. Gangliosides isolated from tumor cells promote collagen-stimulated platelet aggregation and ATP secretion and enhance platelet adhesion to immobilized collagen.

Nonstressed rat model of acute endotoxemia that unmasks the endotoxin-induced TNF-alpha response.

Previous investigators have demonstrated that the tumor necrosis factor-alpha (TNF-alpha) response to endotoxin is inhibited by exogenous corticosterone or catecholamines both in vitro and in vivo, whereas others have reported that surgical and nonsurgical stress increase the endogenous concentrations of these stress-induced hormones. We hypothesized that elevated endogenous stress hormones resultant from experimental protocols attenuated the endotoxin-induced TNF-alpha response. We used a chronically catheterized rat model to demonstrate that the endotoxin-induced TNF-alpha response is 10- to 50-fold greater in nonstressed (NS) rats compared with either surgical-stressed (SS, laparotomy) or nonsurgical-stressed (NSS, tail vein injection) models.

SIDS risk factor awareness: assessment among nursing students.

Objective: To test the hypotheses that nursing students (a) have limited knowledge of risk factors for sudden infant death syndrome (SIDS) and the American Academy of Pediatrics (AAP) recommendation of placing infants on their backs or sides for sleep, and (b) after careful education about SIDS, would retain this information and teach it to parents.

Design: A pretest questionnaire was used to identify knowledge of 13 risk factors and personal recommendation for sleep position. Participants attended a lecture on SIDS and received written educational material.

Indomethacin and pancreatic enzymes synergistically damage intestine of rats.

The use of high-dose pancreatic enzymes by patients with cystic fibrosis was associated with the development of fibrosing colonopathy. Preliminary studies indicated that the infusion of high-dose pancreatic enzymes alone did not cause intestinal damage. We hypothesized that cystic fibrosis patients that developed fibrosing colonopathy had increased intestinal permeability.

The magnitude of brain dopamine depletion from prenatal cocaine exposure is a function of uterine position.

Cocaine's teratogenicity remains equivocal in the literature. The variance in cocaine-induced teratogenic data led us to consider that the intrauterine exposure to cocaine is not homogeneous and that sampling methods presently utilized in the literature lead to inconsistent results. Cocaine's vasoconstrictive actions, in concert with regional variance in the uterine milieu of the rodent, were postulated to differentially reduce the distribution of cocaine to fetal brains as a function of uterine position.

Influence of increased survival in very low birth weight, low birth weight, and normal birth weight infants on the incidence of sudden infant death syndrome in the United States: 1985-1991.

Objective: To examine the relationship between infant survival and the rates sudden infant death syndrome (SIDS) in very low birth weight (VLBW), low birth weight (LBW), and normal birth weight (NBW) infants from 1985 to 1991.

Methods: The National Center for Health Statistics Birth Cohort Linked Birth/Infant Death Data Sets were used to determine birth weight, age at death, and cause of death for US-born singleton infants with birth weights of 500 g or more.

Results: Increasing infant and postneonatal survival rates were greatest in VLBW infants.

Uterine position determines the extent of dopamine reduction after chronic prenatal cocaine exposure.

Most studying the consequences of prenatal cocaine (COC) exposure employ rodents or other multiparous organisms in their models. We have previously shown that when pregnant Sprague-Dawley albino rats are administered a 30 mg/kg subcutaneous (s.c.

Uterine Position Determines the Extent of Dopamine Reduction after Chronic Prenatal Cocaine Exposure.

Most studying the consequences of prenatal cocaine (COC) exposure employ rodents or other multiparous organisms in their models. We have previously shown that when pregnant Sprague-Dawley albino rats are administered a 30 mg/kg subcutaneous (s.c.

Diaphragm pacing with a quadripolar phrenic nerve electrode: an international study.

We sought to determine the international experience with the quadripolar diaphragm pacer system and to test two hypotheses: the incidence of pacer complications would be (1) increased among pediatric as compared to adult patients; and (2) highest among active pediatric patients with idiopathic congenital central hypoventilation syndrome (CCHS). Data were collected via a questionnaire coupled with the Atrotech Registry data for a total of 64 patients (35 children and 29 adults) from 14 countries. Thoracic implantation of electrodes and bilateral pacer use each occurred in 94% of all subjects.

Respiratory control disorders in infancy and childhood.

Current contributions to the literature on disorders of respiratory control in infancy and childhood are reviewed. These encompass studies of cardiorespiratory control in preterm and term infants, apparent life-threatening events in infants, and obstructive sleep apnea including etiology, diagnosis, and alternatives to surgical management. In addition, alveolar hypoventilation is discussed in children with congenital central hypoventilation syndrome, myelomeningocele, and Prader-Willi syndrome.

Neonatal intestinal metabolism.

In the presence of glutamine, glucose, and 3-hydroxybutyrate, glutamine is the preferred oxidative substrate in enterocytes of suckling and weaned rats. Our studies of changes in intestinal metabolism in the developing rat clearly indicate that the oxidation of substrates that enter the citric acid cycle in the form of acetyl-CoA such as glucose, fatty acid, and lipids is low during the suckling period and increases after weaning. In contrast, glutamine that enters the citric acid cycle in the form of 2-oxoglutarate is high during the suckling period and does not change during weaning.

Tumor gangliosides enhance alpha2 beta1 integrin-dependent platelet activation.

Gangliosides, sialic acid-containing glycosphingolipids, enhance platelet adhesion to collagen and consequent platelet activation. For example, gangliosides shed by neuroblastoma tumor cells (NBTG) added to a subthreshold (non-activating) concentration (1 microgram/ml) of collagen, cause platelet aggregation (59 +/- 10%) and ATP release (2.3 +/- 0.

Prenatal cocaine exposure and postnatal hypoxia independently decrease carotid body dopamine in neonatal rats.

The effects of prenatal cocaine exposure on the levels of carotid body dopamine (DA) and its metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) were investigated in 5-day-old rat pups exposed to normoxic and hypoxic conditions. Timed-pregnant Sprague-Dawley rats were injected b.i.