Review: Nutritional regulation of muscle growth in neonatal swine.

Despite advances in the nutritional support of low birth weight and early-weaned piglets, most experience reduced extrauterine growth performance. To further optimize nutritional support and develop targeted intervention strategies, the mechanisms that regulate the anabolic response to nutrition must be fully understood. Knowledge gained in these studies represents a valuable intersection of agriculture and biomedical research, as low birth weight and early-weaned piglets face many of the same morbidities as preterm and low birth weight infants, including extrauterine growth faltering and reduced lean growth. While the reasons for poor growth performance are multifaceted, recent studies have increased our understanding of the role of nutrition in the regulation of skeletal muscle growth in the piglet. The purpose of this review is to summarize the published literature surrounding advances in the current understanding of the anabolic signaling that occurs after a meal and how this response is developmentally regulated in the neonatal pig. It will focus on the regulation of protein synthesis, and especially the upstream and downstream effectors surrounding the master protein kinase, mechanistic target of rapamycin complex 1 (mTORC1) that controls translation initiation. It also will examine the regulatory pathways associated with the postprandial anabolic agents, insulin and specific amino acids, that are upstream of mTORC1 and lead to its activation. Lastly, the integration of upstream signaling cascades by mTORC1 leading to the activation of translation initiation factors that regulate protein synthesis will be discussed. This review concludes that anabolic signaling cascades are stimulated by both insulin and amino acids, especially leucine, through separate pathways upstream of mTORC1, and that these stimulatory pathways result in mTORC1 activation and subsequent activation of downstream effectors that regulate translation initiation Additionally, it is concluded that this anabolic response is unique to the skeletal muscle of the neonate, resulting from increased sensitivity to the rise in both insulin and amino acid after a meal. However, this response is dampened in skeletal muscle of the low birth weight pig, indicative of anabolic resistance. Elucidation of the pathways and regulatory mechanisms surrounding protein synthesis and lean growth allow for the development of potential targeted therapeutics and intervention strategies both in livestock production and neonatal care.

Predictors of patient refusal to participate in ambulatory-based comprehensive geriatric assessment.

BACKGROUND: Comprehensive Geriatric Assessment (CGA) in ambulatory settings can be effective only if patients who need this intervention are willing to participate in the evaluation and follow the indicated therapy. METHODS: To learn whether older persons' health beliefs and perceptions influence participation in ambulatory-based CGA, we studied subjects who failed a screening assessment offered through a community-based outreach program and were deemed appropriate for CGA. All subjects were interviewed in person following a structured sequence including questions from the RAND Current Health (CH) and Health Worry/Concern (HWC) scales, the Health Locus of Control Scale (HLC), and scales developed to measure health risks and perceived benefits of geriatric assessment. RESULTS: In univariate analysis, the following variables were associated with refusal to participate in CGA status at the p < .05 level: increased worry on HWC and higher scores on three new scales constructed to measure Global Health Risk (GHR), Perceived Global Health Benefits (PGHB), and Perceived Specific Health Benefits (PSHB). For GHR, higher scores indicate greater risk; for PGHB and PSHB, higher scores indicate greater perceived benefit. In multivariate analysis, only educational level, GHR, PGHB, and PSHB scores were independently predictive of refuser status. Correlations with other established health perceptions scales provided support that global health risk and perceived global and specific health benefits are unique constructs. Furthermore, high scores on these scales predicted participation in health improvement programs. CONCLUSIONS: Patients' beliefs about perceived risk and benefit can be measured and predict willingness to participate in ambulatory-based CGA.

Male transvestite prostitutes and HIV risk.

Human immunodeficiency virus (HIV)-1, syphilis, and hepatitis B prevalence and associated risk factors were assessed among male transvestite prostitutes. Structured street-level interviews were conducted with 53 respondents in Atlanta, Ga, from July 1990 through July 1991. Test results from serum samples revealed that 68% were seropositive for HIV-1, 81% had seromarkers for syphilis, and 80% had seromarkers for hepatitis B. Univariate logistic regression analysis indicated that seromarkers for syphilis and Black race were the primary factors associated with HIV-1 infection. The results show that transvestite prostitutes are a heterogenous population and distinct from nontransvestite prostitutes; specific outreach is thus needed. Targeted interventions should address the sexual and drug-use-related HIV risk behaviors of transvestite prostitutes.

Comparison of heater probe and YAG laser in endoscopic treatment of major bleeding from peptic ulcers.

In our experience using the YAG laser and the heater probe in endoscopic treatment of major hemorrhage from peptic ulcers, ultimate hemostatic success was achieved in 19 of 20 (95%) ulcers treated with the heater probe, versus 24 of 35 (69%) YAG laser-treated ulcers (p less than 0.05). The heater probe was considerably faster, more convenient to use, and safer than YAG laser. We presently consider the heater probe to be the preferred endoscopic hemostatic device.

Simplified insertion of left atrial pressure monitoring catheter.

A simplified, safe, and reliable technique is described for intraoperative insertion of a left atrial monitoring catheter using modified, currently marketed plastic intravenous catheters.