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.

Blood pressure and intracranial pressure-volume dynamics in severe head injury: relationship with cerebral blood flow.

Abstract: Increased brain tissue stiffness following severe traumatic brain injury is an important factor in the development of raised intracranial pressure (ICP). However, the mechanisms involved in brain tissue stiffness are not well understood, particularly the effect of changes in systemic blood pressure. Thus, controversy exists as to the optimum management of blood pressure in severe head injury, and diverging treatment strategies have been proposed. In the present study, the effect of induced alterations in blood pressure on ICP and brain stiffness as indicated by the pressure-volume index (PVI) was studied during 58 tests of autoregulation of cerebral blood flow in 47 comatose head-injured patients. In patients with intact autoregulation mechanisms, lowering the blood pressure caused a steep increase in ICP (from 20 +/- 3 to 30 +/- 2 mm Hg, mean +/- standard error of the mean), while raising blood pressure did not change the ICP. When autoregulation was defective, ICP varied directly with blood pressure. Accordingly, with intact autoregulation, a weak positive correlation between PVI and cerebral perfusion pressure was found; however, with defective autoregulation, the PVI was inversely related to cerebral perfusion pressure. The various blood pressure manipulations did not significantly alter the cerebral metabolic rate of oxygen, irrespective of the status of autoregulation. It is concluded that the changes in ICP can be explained by changes in cerebral blood volume due to cerebral vasoconstriction or dilatation, while the changes in PVI can be largely attributed to alterations in transmural pressure, which may or may not be attenuated by cerebral arteriolar vasoconstriction, depending on the autoregulatory status. The data indicate that a decline in blood pressure should be avoided in head-injured patients, even when baseline blood pressure is high. On the other hand, induced hypertension did not consistently reduce ICP in patients with intact autoregulation and should only be attempted after thorough assessment of the cerebrovascular status and under careful monitoring of its effects.

Outcomes of 385 Adult-to-Adult Living Donor Liver Transplant Recipients: A Report From the A2ALL Consortium

Abstract: Liver transplantation has become the accepted standard of care for many patients with end-stage liver disease. In the United States, over 5000 patients receive a liver transplant each year.1 With limitations in the supply of deceased donor livers, the waitlist grew rapidly through the 1990s, and although the size of the waiting list has stabilized around 17,000 for the past couple of years, the availability of donors still limits the number of patients who can receive this potentially lifesaving intervention. Efforts to expand the donor pool have resulted in increased use of expanded-criteria donors2–4 and recent application of living donation to the adult population.5–9 First reported in the United States in 1998,10 the use of adult-to-adult living donor transplants (ALDLT) has now been reported in over 1600 patients and has been performed in 94 centers across the United States. The transplant procedure remains a technically complex operation, and the application of living donation to the adult recipient population has added another layer of difficulty to an already challenging procedure. Unlike living donor transplantation in the pediatric population or in kidney transplantation,11,12 there has yet to emerge a clear advantage of ALDLT over transplantation of the liver from deceased donors, beyond the obvious expansion of the donor pool. The extension of living donation to adult recipients requires a major hepatic resection in a healthy person to obtain an adequate graft, engendering controversy regarding both donor risk and increased complexity of the recipient operation.13–16 Most analyses to date have been confined to single-center reports focusing on surgical technique, complications, and selection. Brown et al17 collected the US experience, but this analysis depended on voluntary reporting of programmatic and outcome data. Recent reports utilizing national data from the United Network for Organ Sharing and from the Scientific Registry of Transplant Recipients (SRTR) demonstrate worse outcome of right lobe grafts compared with whole grafts from deceased donors,18,19 but detailed data regarding many donor and recipient variables that may contribute to this outcome are not available from such databases. Limited cases are performed at any one center and approaches to the recipient and donor are too diverse across centers to provide reliable information on outcomes that can be generalized. Therefore, the National Institutes of Health, with supplemental funding from the American Society of Transplant Surgeons and the Health Resources and Services Administration, US Department of Health and Human Services, organized a consortium of 9 leading liver transplantation centers and a data coordinating center to accrue and follow sufficient numbers of patients being considered for and undergoing right lobe ALDLT to provide results from adequately powered studies. This group, the Adult-to-Adult Living Donor Liver Transplantation Cohort Study (A2ALL),20 is conducting both retrospective and prospective studies, with a primary goal of providing information on donor and recipient outcomes of ALDLT over a decade from 1998 to 2008. Although the main outcomes of the A2ALL prospective study will not be available for at least 5 years, insights can be gained from the retrospective cohort study of over 700 donors and recipients treated between 1998 and 2003. This report analyzes detailed recipient outcomes of a large US multicenter experience of 385 right lobe ALDLT grafts. Specific aims included the characterization of the study population with respect to patient selection, the assessment of surgical morbidity and graft failures, and an analysis of the contribution of perioperative clinical factors to surgical outcomes. While this report focuses on first-year outcomes and complications in the recipient, analyses of outcomes and complications among ALDLT donors will be the focus of future reports from the A2ALL Study Group.

International meta-analysis of PTSD genome-wide association studies identifies sex- and ancestry-specific genetic risk loci

Abstract: The risk of posttraumatic stress disorder (PTSD) following trauma is heritable, but robust common variants have yet to be identified. In a multi-ethnic cohort including over 30,000 PTSD cases and 170,000 controls we conduct a genome-wide association study of PTSD. We demonstrate SNP-based heritability estimates of 5-20%, varying by sex. Three genome-wide significant loci are identified, 2 in European and 1 in African-ancestry analyses. Analyses stratified by sex implicate 3 additional loci in men. Along with other novel genes and non-coding RNAs, a Parkinson's disease gene involved in dopamine regulation, PARK2, is associated with PTSD. Finally, we demonstrate that polygenic risk for PTSD is significantly predictive of re-experiencing symptoms in the Million Veteran Program dataset, although specific loci did not replicate. These results demonstrate the role of genetic variation in the biology of risk for PTSD and highlight the necessity of conducting sex-stratified analyses and expanding GWAS beyond European ancestry populations.

The fifteenth data release of the Sloan Digital Sky Surveys: First release of MaNGA-derived quantities, data visualization tools, and stellar library

Abstract: Twenty years have passed since first light for the Sloan Digital Sky Survey (SDSS). Here, we release data taken by the fourth phase of SDSS (SDSS-IV) across its first three years of operation (2014 July–2017 July). This is the third data release for SDSS-IV, and the 15th from SDSS (Data Release Fifteen; DR15). New data come from MaNGA—we release 4824 data cubes, as well as the first stellar spectra in the MaNGA Stellar Library (MaStar), the first set of survey-supported analysis products (e.g., stellar and gas kinematics, emission-line and other maps) from the MaNGA Data Analysis Pipeline, and a new data visualization and access tool we call "Marvin." The next data release, DR16, will include new data from both APOGEE-2 and eBOSS; those surveys release no new data here, but we document updates and corrections to their data processing pipelines. The release is cumulative; it also includes the most recent reductions and calibrations of all data taken by SDSS since first light. In this paper, we describe the location and format of the data and tools and cite technical references describing how it was obtained and processed. The SDSS website (www.sdss.org) has also been updated, providing links to data downloads, tutorials, and examples of data use. Although SDSS-IV will continue to collect astronomical data until 2020, and will be followed by SDSS-V (2020–2025), we end this paper by describing plans to ensure the sustainability of the SDSS data archive for many years beyond the collection of data.

Addressing the Vacant and Abandoned Property Problem

Abstract: Vacant and abandoned property is increasingly recognized as a significant barrier to the revitalization of central cities. This study sheds some light on the nature of the property abandonment problem and on current city efforts to address it. It is based upon the findings of a survey of the 200 most populous central cities in the United States, conducted during the summer and fall of 1997, and on follow-up interviews with a portion of the survey population, conducted during the summer of 1998. The findings of the survey and interviews indicate that vacant and abandoned property is perceived as a significant problem by elected and appointed officials in the nation’s largest central cities. This type of property affects many aspects of community life, including housing and neighborhood vitality, crime prevention efforts, and commercial district vitality. Single- and multi-family housing, retail properties and vacant land are the most problematic types of vacant and abandoned property for most cities. Citie...