University of Tennessee Health Science Center

About: University of Tennessee Health Science Center is a education organization based out in Memphis, Tennessee, United States. It is known for research contribution in the topics: Population & Medicine. The organization has 15716 authors who have published 26884 publications receiving 1176697 citations.

A Meta-Analysis of Immunosuppression Withdrawal Trials in Renal Transplantation

Abstract: . Since the publication of previous meta-analyses of cyclosporine (CsA) and prednisone withdrawal in renal transplant recipients, several additional randomized controlled trials with longer follow-up have been reported. Currently, in nine prednisone withdrawal trials ( n = 1461), the proportion of patients with acute rejection was increased by 0.14 (95% confidence interval = 0.10 to 0.17, P n = 1899), the relative risk (RR; RR = 1.0 indicates no risk) of graft failure after withdrawal was also increased (RR = 1.40; range, 1.09 to 1.70, P = 0.012). There was no evidence of between-study heterogeneity for either acute rejection or graft failure in the prednisone withdrawal trials by a χ 2 test ( P > 0.05). In 10 CsA withdrawal trials ( n = 1049), the proportion of patients with acute rejection was increased by 0.11 (0.07 to 0.15, P n = 1151), the RR of graft failure after CsA withdrawal was 1.06 (95% confidence interval, 0.82 to 1.29, P = 0.646), but a χ 2 test indicated that there was study heterogeneity. However, there was no evidence of heterogeneity in the six studies ( n = 632) with at least 4.0 yr (5.8 ± 1.7) of follow-up (RR = 0.92; range, 0.64 to 1.20, P = 0.569) or in the seven trials ( n = 962) published in peer-reviewed journals (RR = 0.95; range, 0.70 to 1.20 P = 0.682). Finally, in three trials ( n = 259) that compared CsA and prednisone withdrawal, there was a nonsignificant trend for less graft failure with CsA withdrawal (RR = 0.63; range, 0.08 to 1.16, P = 0.190). Thus, unlike prednisone withdrawal, CsA withdrawal in select patients seems to impart little risk of long-term graft failure.

Evolution of Swine H3N2 Influenza Viruses in the United States

Abstract: During 1998, severe outbreaks of influenza were observed in four swine herds in the United States. This event was unique because the causative agents, H3N2 influenza viruses, are infrequently isolated from swine in North America. Two antigenically distinct reassortant viruses (H3N2) were isolated from infected animals: a double-reassortant virus containing genes similar to those of human and swine viruses, and a triple-reassortant virus containing genes similar to those of human, swine, and avian influenza viruses (N. N. Zhou, D. A. Senne, J. S. Landgraf, S. L. Swenson, G. Erickson, K. Rossow, L. Liu, K.-J. Yoon, S. Krauss, and R. G. Webster, J. Virol. 73:8851–8856, 1999). Because the U.S. pig population was essentially naive in regard to H3N2 viruses, it was important to determine the extent of viral spread. Hemagglutination inhibition (HI) assays of 4,382 serum samples from swine in 23 states indicated that 28.3% of these animals had been exposed to classical swine-like H1N1 viruses and 20.5% had been exposed to the triple-reassortant-like H3N2 viruses. The HI data suggested that viruses antigenically related to the double-reassortant H3N2 virus have not become widespread in the U.S. swine population. The seroreactivity levels in swine serum samples and the nucleotide sequences of six additional 1999 isolates, all of which were of the triple-reassortant genotype, suggested that H3N2 viruses containing avian PA and PB2 genes had spread throughout much of the country. These avian-like genes cluster with genes from North American avian viruses. The worldwide predominance of swine viruses containing an avian-like internal gene component suggests that these genes may confer a selective advantage in pigs. Analysis of the 1999 swine H3N2 isolates showed that the internal gene complex of the triple-reassortant viruses was associated with three recent phylogenetically distinct human-like hemagglutinin (HA) molecules. Acquisition of HA genes from the human virus reservoir will significantly affect the efficacy of the current swine H3N2 vaccines. This finding supports continued surveillance of U.S. swine populations for influenza virus activity.

Content-rich biological network constructed by mining PubMed abstracts.

Abstract: The integration of the rapidly expanding corpus of information about the genome, transcriptome, and proteome, engendered by powerful technological advances, such as microarrays, and the availability of genomic sequence from multiple species, challenges the grasp and comprehension of the scientific community. Despite the existence of text-mining methods that identify biological relationships based on the textual co-occurrence of gene/protein terms or similarities in abstract texts, knowledge of the underlying molecular connections on a large scale, which is prerequisite to understanding novel biological processes, lags far behind the accumulation of data. While computationally efficient, the co-occurrence-based approaches fail to characterize (e.g., inhibition or stimulation, directionality) biological interactions. Programs with natural language processing (NLP) capability have been created to address these limitations, however, they are in general not readily accessible to the public. We present a NLP-based text-mining approach, Chilibot, which constructs content-rich relationship networks among biological concepts, genes, proteins, or drugs. Amongst its features, suggestions for new hypotheses can be generated. Lastly, we provide evidence that the connectivity of molecular networks extracted from the biological literature follows the power-law distribution, indicating scale-free topologies consistent with the results of previous experimental analyses. Chilibot distills scientific relationships from knowledge available throughout a wide range of biological domains and presents these in a content-rich graphical format, thus integrating general biomedical knowledge with the specialized knowledge and interests of the user. Chilibot http://www.chilibot.net can be accessed free of charge to academic users.

Lennox-Gastaut syndrome: a consensus approach on diagnosis, assessment, management, and trial methodology

Abstract: Lennox-Gastaut syndrome is one of the most severe epileptic encephalopathies of childhood onset. The cause of this syndrome can be symptomatic (ie, secondary to an underlying brain disorder) or cryptogenic (ie, has no known cause). Although Lennox-Gastaut syndrome is commonly characterised by a triad of signs, which include multiple seizure types, slow spike-wave complexes on electroencephalographic (EEG) recordings, and impairment of cognitive function, there is debate with regard to the precise limits, cause, and diagnosis of the syndrome. Tonic seizures, which are thought to be a characteristic sign of Lennox-Gastaut syndrome, are not present at onset and the EEG features are not pathognomonic of the disorder. There are few effective treatment options for the multiple seizures and comorbidities, and the long-term outlook is poor for most patients. Probably as a result of the complexity of the disorder, only a few randomised trials have studied Lennox-Gastaut syndrome, and thus many of the drugs that are more commonly used have little or no supporting evidence base from controlled trials. In this Review, we discuss the main issues with regard to the diagnosis and treatment options available. We also suggest key considerations for future trials and highlight the importance of a comprehensive approach to the assessment and management of this syndrome.