Virginia Commonwealth University

About: Virginia Commonwealth University is a education organization based out in Richmond, Virginia, United States. It is known for research contribution in the topics: Population & Health care. The organization has 23822 authors who have published 49587 publications receiving 1787046 citations. The organization is also known as: VCU.

Multivariate analysis of risk factors for death following gastric bypass for treatment of morbid obesity.

Abstract: More than half of Americans are overweight, and more than 1 in 5 are obese.1 The prevalence of obesity has tripled in the last 30 years. This has resulted in significant costs to society both in lost productivity and increased health expenditures. It is estimated that 300,000 deaths a year are related to obesity and close to $100 billion are spent on obesity-related health care costs.2 Diet and exercise therapy are frequently associated with weight loss failure.3 Currently, surgery offers the only effective long-term weight loss therapy for morbidly obese patients. Increased media attention in the United States as well as the newer option of laparoscopic treatment has led patients and surgeons to embrace surgical options in unprecedented numbers, particularly the option of laparoscopic Roux-en-Y gastric bypass (L-GBP). The reported incidence of perioperative mortality varies between 0% and 1.5% in series of open Roux-en-Y gastric bypass (O-GBP)4–6 and L-GBP.7–10 With the increasing popularity and performance of the GBP, it is clear that the operative mortality for this procedure will attract greater public scrutiny. No prior population-based study has been able to delineate independent predictors of death. Two large series have defined risk factors for complications but were unable to do the same for mortality.11,12 Livingston et al did show a significantly higher mortality in patients older than 55 years, but he was unable to show that age was ultimately predictive of mortality.11 It is important to define predictors of mortality so that surgeons can give potential patients better risk information, obtain more accurate informed consent, and possibly avoid unacceptably high-risk operations. Death after GBP is infrequent, and accurate risk assessment requires a large series of patients. We used a large prospective database of more than 2000 gastric bypass procedures over a 10-year experience, including O-GBP and L-GBP, to define independent predictors for early death using a multivariate logistic regression analysis. The results should benefit surgeons, patients, and the general public in understanding the mortality risk for this operation.

Differential heritability of adult and juvenile antisocial traits.

Abstract: Background: Studies of adult antisocial behavior or criminality usually find genetic factors to be more important than the family environment, whereas studies of delinquency find the family environment to be more important. We comparedDSM-III-Rantisocial personality disorder symptoms before vs after the age of 15 years within a sample of twins, rather than comparing across studies. Methods: We administered the Diagnostic Interview Schedule Version III—revised by telephone to 3226 pairs of male twins from the Vietnam Era Twin Registry. Biometrical modeling was applied to each symptom of antisocial personality disorder and summary measures of juvenile and adult symptoms. Results: Five juvenile symptoms were significantly heritable, and five were significantly influenced by the shared environment. Eight adult symptoms were significantly heritable, and one was significantly influenced by the shared environment. The shared environment explained about six times more variance in juvenile antisocial traits than in adult traits. Shared environmental influences on adult antisocial traits overlapped entirely with those on juvenile traits. Additive genetic factors explained about six times more variance in adult vs juvenile traits. The juvenile genetic determinants overlapped completely with genetic influences on adult traits. The unique environment (plus measurement error) explained the largest proportion of variance in both juvenile and adult antisocial traits. Conclusions: Characteristics of the shared or family environment that promote antisocial behavior during childhood and early adolescence also promote later antisocial behavior, but to a much lesser extent. Genetic causal factors are much more prominent for adult than for juvenile antisocial traits.

Epidemiology and Natural History of Nonalcoholic Fatty Liver Disease.

Abstract: The epidemic of obesity has resulted in a parallel incremental burden of nonalcoholic fatty liver disease (NAFLD) worldwide. Nonalcoholic fatty liver disease includes a spectrum of liver disease that ranges from simple fat accumulation in the liver to necroinflammation, fibrosis, cirrhosis, and hepatocellular carcinoma, which in essence represent the stages of the natural history of NAFLD. The rising prevalence of NAFLD globally may be accounted for by changes in dietary habits and an increase in sedentary lifestyle. Nonalcoholic steatohepatitis (NASH), the aggressive form of NAFLD, is currently the second leading etiology of liver disease among adults awaiting liver transplantation in the United States. In the current review, the authors discuss the uncertainty around the progression from NAFL (steatosis) to NASH (steatohepatitis), the undisputed progression of NASH to cirrhosis, and the risk factors that predispose to such progression. The published literature on the long-term cardiovascular complications and liver-related mortality of NAFLD is also discussed.

A model-data comparison of gross primary productivity: Results from the North American Carbon Program site synthesis

Abstract: [1] Accurately simulating gross primary productivity (GPP) in terrestrial ecosystem models is critical because errors in simulated GPP propagate through the model to introduce additional errors in simulated biomass and other fluxes. We evaluated simulated, daily average GPP from 26 models against estimated GPP at 39 eddy covariance flux tower sites across the United States and Canada. None of the models in this study match estimated GPP within observed uncertainty. On average, models overestimate GPP in winter, spring, and fall, and underestimate GPP in summer. Models overpredicted GPP under dry conditions and for temperatures below 0°C. Improvements in simulated soil moisture and ecosystem response to drought or humidity stress will improve simulated GPP under dry conditions. Adding a low-temperature response to shut down GPP for temperatures below 0°C will reduce the positive bias in winter, spring, and fall and improve simulated phenology. The negative bias in summer and poor overall performance resulted from mismatches between simulated and observed light use efficiency (LUE). Improving simulated GPP requires better leaf-to-canopy scaling and better values of model parameters that control the maximum potential GPP, such asemax (LUE), Vcmax (unstressed Rubisco catalytic capacity) or Jmax (the maximum electron transport rate).