The role of glutamine in maintaining a healthy gut and supporting the metabolic response to injury and infection

In the critically ill surgical patient a variety of therapeutic maneuvers is required to maintain a "healthy gut." Provision of adequate amounts of glutamine to the gastrointestinal mucosa appears to be just one of these maneuvers. Other methods utilized to protect the gut from becoming a wound include: (a) minimizing additional systemic insults (such as hypotension, sepsis, multiple operative procedures); (b) aggressive pulmonary care; (c) the judicious use of antibiotics; and (d) aggressive enteral or parenteral feedings. The concept that the gut is an organ of quiescence following surgical stress merits reconsideration. The intestinal tract plays a central role in interorgan glutamine metabolism and is a key regulator of nitrogen handling following surgical stress. Critically ill patients are susceptible to developing gut-origin sepsis, the incidence of which will be diminished by instituting measures and providing treatments which support intestinal structure, function, and metabolism. Provision of glutamine-enriched diets to such patients may be one of these therapies.     

Endophthalmitis after penetrating ocular trauma

Endophthalmitis following penetrating eye injuries has a relatively poor prognosis due to the underlying eye trauma and the frequency of more virulent organisms such as Bacillus species. Risk factors for infection include 1) retained intraocular foreign body, 2) a rural injury setting, 3) delay in primary wound closure, and 4) disruption of the crystalline lens. Although endophthalmitis is difficult to distinguish from traumatic changes, recognition of early clinical signs of endophthalmitis, such as hypopyon, vitritis, or retinal periphlebitis, is important and early treatment is recommended. Comprehensive prophylactic antibiotic treatment at the time of injury repair combined with timely diagnostic vitrectomy and injection of intravitreal antibiotics when infection is suspected may significantly improve visual acuity outcomes following penetrating injuries. Treatment includes intravitreal, periocular, and systemic antibiotics. Intravitreal and periocular corticosteroids are also recommended. Recent and past literature supporting these recommendations, as well as the authors' specific prevention and treatment protocols for post-traumatic endophthalmitis, is included in this review.     

Uptake of chloroform by skin on brief exposures to the neat liquid

The uptake of chloroform into hairless rat's stratum corneum after application of the neat solvent directly to the skin has been studied. Tape stripping was used to determine amounts deposited within the stratum corneum and also the clearance of the compound from the skin following varied levels of exposure. Three minutes exposure to neat chloroform was adequate to achieve a limiting accumulation in the stratum corneum and thus it appears to take this long for the gradient of chloroform to be established fully across this structure. There was indication of progressively deeper penetration of chloroform as the exposure time was increased from 1 to 8 minutes. Local irritation and a loosening of the superficial layers of stratum corneum were apparent with as little as 2 minutes of exposure to the solvent and were exacerbated with further increases in exposure duration. Following exposure, clearance of the solvent from the skin surface was rapid. Interestingly, the rate of clearance, as followed by stripping, was comparable on live and freshly euthanized rats. This implies that once the exposure is terminated evaporation from the surface, and not systemic uptake by way of the local vasculature, is the predominant means of clearance at an open surface.     

Modeling breathing-zone concentrations of airborne contaminants generated during compressed air spray painting

This paper presents a mathematical model to predict breathing-zone concentrations of airborne contaminants generated during compressed air spray painting in cross-flow ventilated booths. The model focuses on characterizing the generation and transport of overspray mist. It extends previous work on conventional spray guns to include exposures generated by HVLP guns. Dimensional analysis and scale model wind-tunnel studies are employed using non-volatile oils, instead of paint, to produce empirical equations for estimating exposure to total mass. Results indicate that a dimensionless breathing zone concentration is a nonlinear function of the ratio of momentum flux of air from the spray gun to the momentum flux of air passing through the projected area of the worker's body. The orientation of the spraying operation within the booth is also very significant. The exposure model requires an estimate of the contaminant generation rate, which is approximated by a simple impactor model. The results represent an initial step in the construction of more realistic models capable of predicting exposure as a mathematical function of the governing parameters.     

Psychiatric comorbidity measures as predictors of retention in drug abuse treatment programs.

OBJECTIVE: To examine lifetime and current psychiatric comorbidity measures as predictors of drug abuse treatment retention, and to test the generalizability of results across treatment agencies in diverse settings and with varying practices. DATA SOURCES/STUDY SETTING: The national Drug Abuse Treatment Outcome Studies (DATOS), a longitudinal study of clients from 96 treatment agencies in 11 U.S. cities. STUDY DESIGN: The design is naturalistic and uses longitudinal analysis of treatment retention in long-term residential, outpatient drug-free, and outpatient methadone treatment modalities; client background (including psychiatric comorbidity) and program service provision are predictors. Clinical thresholds for adequate treatment retention were 90 days for long-term residential and outpatient drug-free, and 360 days for outpatient methadone. Psychiatric indicators included lifetime DSM-III-R diagnoses of depression/anxiety and antisocial personality, and dimensional measures of current symptoms for depression and hostility. DATA COLLECTION/EXTRACTION METHODS: Data include structured interviews with clients, a survey of treatment program administrators, and program discharge records. PRINCIPAL FINDINGS: Dimensional measures of current psychiatric symptoms emerged as better predictors than lifetime DSM-III-R diagnoses. In addition, the predictive association of hostility with retention varied significantly across treatment agencies, both in the long-term residential and outpatient drug-free modalities. Other notable findings were that on-site mental health services in long-term residential programs were associated with better retention for clients with symptoms of hostility. CONCLUSIONS: Assessment issues and stability of results across programs are important considerations for treatment research and practice.     

Neuropeptide Y-related compounds and feeding

Neuropeptide Y (NPY) and related compounds increase short-term feeding. Previous studies have used different animal models, feeding schedules, sources of the compounds, and time and routes of administration. These differences in methodology are important in the variability reported on the potency of NPY-related compounds. To obtain reliable data on the relative efficacy, we tested NPY, NPY 3-36, and pancreatic polypeptide (PP) using an identical protocol and the same commercial source. These three NPY-related compounds were tested using the intracerebroventricular (i.c.v., into the third ventricle) administration, and the profile of the feeding enhancement including the dose response and potency was determined. Compounds were tested in parallel on at least 2 successive days. NPY, NPY 3-36, and PP exhibited different potencies in enhancing 2-h food intake. Comparison of their dose responses (using 0.1, 0.25, 0.5, 1.0, 2.5, and 5.0 microg/rat) demonstrated an overall potency of NPY 3-36 > NPY > PP for the high doses. To study ligand interactions, we examined the effects of various combinations of NPY-related compounds administered concomitantly. These combinations were justified based on the data obtained from the individual dose responses. The data show that the effects of NPY plus NPY 3-36 or NPY 3-36 plus PP were less than additive. When compared to the individual responses, the effects of NPY 3-36 were almost identical to those induced by the combinations using low doses of NPY plus NPY 3-36, or low and high doses of PP plus NPY 3-36. The results support the notion that NPY and its analogues induce a short-term feeding response by activating multiple receptor subtypes.