Delivery of total parenteral nutrition (TPN) via umbilical catheterization: development of a piglet model to investigate therapies to improve gastrointestinal structure and enzyme activity during TPN

Nutritional support of preterm infants by total parental nutrition (TPN) is common; however, TPN compromises intestinal structure and enzyme activity. Our goal was to develop a piglet model to assess the effect of limited enteral stimulation with formula and insulin-like growth factor-I (IGF-I) on intestinal morphology and enzyme activity. A nutritionally complete TPN solution was infused for 7 days and piglets were gavaged twice daily with 4 ml sterile water, formula, or formula containing 1,000 micrograms/l IGF-I. Litter mate piglets fed formula served as orally fed controls. On day 7, body weights and plasma hormone profiles of TPN and orally fed piglets were similar. However, intestinal weight, jejunal and ileal villus height and surface area, and mucosal lactase and sucrase activity of TPN piglets was reduced by approximately 50%. No effect of limited enteral stimulation or IGF-I was observed likely due to the small volume of formula administered enterally, which resulted in a low dose of IGF-I (4.3 micrograms IGF-I/kg/day).     

Gene therapy for cystic fibrosis: perspectives for the otolaryngologist

Morbidly obese patients are prone to many clinical conditions that can effect anaesthesia. Of major concern to the anaesthetist are difficulties with airway management and abnormalities of cardiorespiratory function. Safe anaesthesia requires an appreciation of potential problems and a thorough understanding of the pathophysiological changes that accompany morbid obesity.     

Improving Predictive Accuracy with a Combination of Human Intuition and Mechanical Decision Aids

This study examines the intuitive combination of human judgment and mechanical prediction under varied information conditions. As expected, mechanical prediction outperformed human intuition when based on the same information, but a combined approach was best when judges had access to relevant information not captured by the model (information asymmetry). The model was useful for differentiating between the event outcomes (improved slope), while eliminating the bias caused by base-rate neglect. Human intuition was useful for incorporating relevant information outside the scope of the model, resulting in improved slope and reduced judgment scatter. The addition of irrelevant information was detrimental to judgment accuracy, causing an increase in bias and a reduction in slope. These results provide insight into how and when combining mechanical prediction and human intuition is likely to result in improved accuracy. Copyright 1998 Academic Press.     

Monitoring for intraoperative awareness

Despite advances in anesthetic technique and technology, intraoperative awareness continues to occur with alarming regularity. The psychological effects on patients and the medicolegal consequences to providers have created the need for a reliable monitor of the hypnotic component of anesthesia. A new technology known as bispectral analysis (BIS) has the potential to put an end to the devastating occurrence of intraoperative awareness, as well as improve the overall effectiveness of anesthetic delivery and the surgical experience. Applicable to almost any situation requiring sedation or general anesthesia, BIS's reliability is a real-time measure of hypnosis levels.     

Phonosurgery

Phonosurgery is composed of procedures that are intended to maintain or improve the quality of the voice by correcting defects in laryngeal sound production. These procedures are rooted in a rich medical history that dates back to the early 19th century. There has been a recent convergence of physiologic principles of voice production with surgical technique theory. Recognition of this interdependence has provided a catalyst for collaboration among surgeons, scientists, speech pathologists, vocal pedagogists, and performing artists. We live in a society that is linked to effective communication, and there is a growing population of individuals who have professional voice responsibilities as part of everyday life. This has created a need for the recent developments in phonosurgery and its emergence as a subspecialty of otolaryngology.     

The role of nitric oxide and NMDA receptors in the development of motor neuron dendrites

Nitric oxide (NO) has been implicated in the establishment of precise synaptic connectivity throughout the neuroaxis in several species. To determine the contribution of NO to NMDA receptor-dependent dendritic growth in motor neurons, we administered the NMDA antagonist MK-801 to wild-type mice and neuronal nitric oxide synthase (nNOS) knock-out mice between postnatal days 7 and 14. Compared to saline-treated wild-type animals the number of dendritic bifurcations was significantly reduced in nNOS knock-out animals and MK-801-treated wild-type animals. There was no significant difference in dendritic bifurcation between MK-801-treated wild-type, MK-801-treated nNOS knock-out, and saline-treated nNOS knock-out animals, suggesting that nNOS knock-out and NMDA receptor block had similar effects. The path of the longest dendrite and the number of primary dendrites was the same in all treatment groups, indicating an effect specific to bifurcation. Sholl analysis revealed that differences in bifurcation numbers occurred between 160 and 320 micrometers from the cell body, the distance at which second, third, and fourth order dendrites are most prevalent. Dendrite order analyses confirmed a significant reduction in numbers, but not lengths, of third and fourth order dendrites in nNOS knock-out and drug-treatment groups. Finally, immunohistochemical examination of the developing spinal cord indicated that NMDA receptors and nNOS are colocalized within interneurons surrounding the motor neuron pool. These results support the view that at least part of NMDA receptor-dependent arborization of motor neuron dendrites is mediated by the local production of NO within the developing spinal cord.