Mutation in the myelin proteolipid protein gene alters BK and SK channel function in the caudal medulla.

Proteolipid protein (Plp) gene mutation in rodents causes severe CNS dysmyelination, early death, and lethal hypoxic ventilatory depression (Miller et al., 2004). To determine if Plp mutation alters neuronal function critical for control of breathing, the nucleus tractus solitarii (nTS) of four rodent strains were studied: myelin deficient rats (MD), myelin synthesis deficient (Plp(msd)), and Plp(null) mice, as well as shiverer (Mbp(shi)) mice, a myelin basic protein mutant.

Neuronal expression of the proteolipid protein gene in the medulla of the mouse.

The proteolipid protein (PLP) gene (Plp) encodes the major myelin proteins, PLP and DM20. Expression of Plp occurs predominantly in oligodendrocytes, but evidence is accumulating that this gene is also expressed in neurons. In earlier studies, we demonstrated that myelin-deficient (MD) rats, which carry a mutation in the Plp gene, exhibit lethal hypoxic ventilatory depression.

Hyperbilirubinemia diminishes respiratory drive in a rat pup model.

Although apnea is common in premature babies, there is a paucity of information concerning the pathophysiologic basis of these episodes and their relationship to other perinatal conditions such as hyperbilirubinemia. Unconjugated hyperbilirubinemia in premature infants, even in moderately high levels, may cause encephalopathy affecting brainstem functions and has been linked to increased incidence of apnea in these infants. Thus, there is a need to clarify mechanisms by which bilirubin may alter respiratory control and induce apnea of prematurity.

Short-term mechanical ventilation increases airway reactivity in rat pups.

We used a rat pup model to delineate whether mechanical ventilation of 95% O2). After each intervention, they were returned to their mothers.

Biodegradation of alpha-pinene in model biofilms in biofilters.

Treatment of air pollutants in a biofilter requires that the compound be effectively transported from the gas phase to the organisms that reside in a biofilm that forms upon a packing material. Models of biofiltration generally treat the biofilm like water by using a Henry's law constant to predict mass transfer rates into the biofilm where degradation occurs and, hence, predict low rates for hydrophobic compounds. However, some compounds that are virtually insoluble in water are also treated unusually well.

Relationship between respiratory control and feeding in the developing infant.

Simultaneous breathing and nursing from a bottle or breast requires intricate coordination of the muscles that serve both respiration and feeding. During the buccopharyngeal phase of feeding reflex input to the brainstem from the oropharynx and larynx, as well as suprabulbar and chemoreceptor areas controls the sequential activity of the muscles of deglutition. Coordinated development of buccopharyngeal functions generally occurs by 35 weeks post-conceptional age in infants, but can be disrupted by respiratory disease or neuropathology.

Proteolipid protein gene mutation induces altered ventilatory response to hypoxia in the myelin-deficient rat.

Pelizaeus Merzbacher disease is an X-linked dysmyelinating disorder of the CNS, resulting from mutations in the proteolipid protein (PLP) gene. An animal model for this disorder, the myelin-deficient (MD) rat, carries a point mutation in the PLP gene and exhibits a phenotype similar to the fatal, connatal disease, including extensive dysmyelination, tremors, ataxia, and death at approximately postnatal day 21 (P21). We postulated that early death might result from disruption of myelinated neural pathways in the caudal brainstem and altered ventilatory response to oxygen deprivation or hypercapnic stimulus.

Relation of sleep state to hypoxemic episodes in ventilated extremely-low-birth-weight infants.

Objective: To determine whether hypoxemic episodes in ventilated extremely-low-birth-weight infants correlate with specific behavioral states.

Study Design: Three-hour video-electroencephalography-polysomnography was performed on 13 ventilated extremely-low-birth-weight infants with mean postconceptional age of 28.3 weeks.

Infant animal model of pulmonary mycotoxicosis induced by Stachybotrys chartarum.

In recent years cases of often fatal pulmonary hemorrhage in infants have been associated with water damaged homes and the toxigenic fungus Stachybotrys chartarum. The fungal spores contain mycotoxins which could be injurious to the rapidly developing lung. In order to understand the developmental pathophysiology of this disease we developed an infant rat model of stachybotrytoxicosis describing the effects of fungal spores on survival, growth, histopathology of the lung and respiration.