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 & Transplantation. The organization has 15716 authors who have published 26884 publications receiving 1176697 citations.

One- and two-year change in body composition as measured by DXA in a population-based cohort of older men and women.

Abstract: Changing body composition has been suggested as a pathway to explain age-related functional decline. No data are available on the expected changes in body composition as measured by dual-energy X-ray absorptiometry (DXA) in a population-based cohort of older persons. Body composition data at baseline, 1-yr follow-up, and 2-yr follow-up was measured by DXA in 2,040 well-functioning black and white men and women aged 70-79 yr, participants of the Health, Aging, and Body Composition Study. After 2 yr, a small decline in total body mass was observed (men: -0.3%, women: -0.4%). Among men, fat-free mass and appendicular lean soft tissue mass (ALST) decreased by -1.1 and -0.8%, respectively, which was masked by a simultaneous increase in total fat mass (+2.0%). Among women, a decline in fat-free mass was observed after 2 yr only (-0.6%) with no change in ALST and body fat mass. After 2 yr, the decline in ALST was greater in blacks than whites. Change in total body mass was associated with change in ALST (r = +0.58 to +0.70; P < 0.0001). Among participants who lost total body mass, men lost relatively more ALST than women, and blacks lost relatively more ALST than whites. In conclusion, the mean change in body composition after a 1- to 2-yr follow-up was 1-2% with a high interindividual variability. Loss of ALST was greater in men compared with women, and greater in blacks compared with whites, suggesting that men and blacks may be more prone to muscle loss.

Pdr1 regulates multidrug resistance in Candida glabrata: gene disruption and genome-wide expression studies.

Abstract: Candida glabrata emerged in the last decade as a common cause of mucosal and invasive fungal infection, in large part due to its intrinsic or acquired resistance to azole antifungals such as fluconazole In C glabrata clinical isolates, the predominant mechanism behind azole resistance is upregulated expression of multidrug transporter genes CDR1 and PDH1 We previously reported that azole-resistant mutants (MIC >or= 64 microg ml(-1)) of strain 66032 (MIC = 16 microg ml(-1)) similarly show coordinate CDR1-PDH1 upregulation, and in one of these (F15) a putative gain-of-function mutation was identified in the single homologue of Saccharomyces cerevisiae transcription factors Pdr1-Pdr3 Here we show that disruption of C glabrata PDR1 conferred equivalent fluconazole hypersensitivity (MIC = 2 microg ml(-1)) to both F15 and 66032 and eliminated both constitutive and fluconazole-induced CDR1-PDH1 expression Reintroduction of wild-type or F15 PDR1 fully reversed these effects; together these results demonstrate a role for this gene in both acquired and intrinsic azole resistance CDR1 disruption had a partial effect, reducing fluconazole trailing in both strains while restoring wild-type susceptibility (MIC = 16 microg ml(-1)) to F15 In an azole-resistant clinical isolate, PDR1 disruption reduced azole MICs eight- to 64-fold with no effect on sensitivity to other antifungals To extend this analysis, C glabrata microarrays were generated and used to analyse genome-wide expression in F15 relative to its parent Homologues of 10 S cerevisiae genes previously shown to be Pdr1-Pdr3 targets were upregulated (YOR1, RTA1, RSB1, RPN4, YLR346c and YMR102c along with CDR1, PDH1 and PDR1 itself) or downregulated (PDR12); roles for these genes include small molecule transport and transcriptional regulation However, expression of 99 additional genes was specifically altered in C glabrata F15; their roles include transport (eg QDR2, YBT1), lipid metabolism (ATF2, ARE1), cell stress (HSP12, CTA1), DNA repair (YIM1, MEC3) and cell wall function (MKC7, MNT3) These azole resistance-associated changes could affect C glabrata tissue-specific virulence; in support of this, we detected differences in F15 oxidant, alcohol and weak acid sensitivities C glabrata provides a promising model for studying the genetic basis of multidrug resistance and its impact on virulence

MR imaging differentiation of benign and malignant peripheral nerve sheath tumors: use of the target sign

Abstract: T2-weighted MR imaging of soft tissue tumors of neural origin may show round lesions with a central hypointensity and a hyperintense rim resembling a target. We define the “target sign” as a mass consisting of a solitary target, or a multicompartmental mass in which the largest component consists of multiple targets. The objective of this study was to determine whether the target sign can differentiate benign neurofibromas and their malignant counterparts, malignant peripheral nerve sheath tumors. Preoperative T2-weighted MR images of 23 neurofibromas or malignant peripheral nerve sheath tumors were retrospectively reviewed in 16 patients, aged 3 weeks to 20 years (median 15 years), without knowledge of the pathologic diagnosis. The presence or absence of a target sign was noted. The target sign was seen in all 12 neurofibromas and 1 of the 11 malignant peripheral nerve sheath tumors. Statistical analysis showed good differentiation of benign and malignant tumors using this sign (x = 0.91). The target sign on T2-weighted MR imaging is helpful in differentiating neurofibromas from malignant peripheral nerve sheath tumors.

Regulation of intestinal lipid metabolism: current concepts and relevance to disease

Abstract: Lipids entering the gastrointestinal tract include dietary lipids (triacylglycerols, cholesteryl esters and phospholipids) and endogenous lipids from bile (phospholipids and cholesterol) and from shed intestinal epithelial cells (enterocytes). Here, we comprehensively review the digestion, uptake and intracellular re-synthesis of intestinal lipids as well as their packaging into pre-chylomicrons in the endoplasmic reticulum, their modification in the Golgi apparatus and the exocytosis of the chylomicrons into the lamina propria and subsequently to lymph. We also discuss other fates of intestinal lipids, including intestinal HDL and VLDL secretion, cytosolic lipid droplets and fatty acid oxidation. In addition, we highlight the applicability of these findings to human disease and the development of therapeutics targeting lipid metabolism. Finally, we explore the emerging role of the gut microbiota in modulating intestinal lipid metabolism and outline key questions for future research. The small intestine is a key site for the absorption of nutrients, including lipids. In this Review, the physiology and biochemistry of intestinal fat absorption during health and disease is discussed, including insights into enterocyte biology and clinical disorders of intestinal fat absorption.

Survival and Neurodevelopmental Outcome of Young Children With Medulloblastoma at St Jude Children's Research Hospital

Abstract: PURPOSE: Young children treated for medulloblastoma are at especially high risk for morbidity and mortality from their disease and therapy. This study sought to assess the relationship, if any, between patient outcome and M stage. Neuropsychologic and endocrine outcomes were also assessed. PATIENTS AND METHODS: Twenty-nine consecutively diagnosed infants and young children were treated for medulloblastoma at St Jude Children's Research Hospital between November 1984 and December 1995. All patients were treated with the intent of using postoperative chemotherapy to delay planned irradiation. RESULTS: The median age at diagnosis was 2.6 years. Six patients completed planned chemotherapy without progressive disease and underwent irradiation at completion of chemotherapy. Twenty-three children experienced disease progression during chemotherapy and underwent irradiation at the time of progression. The 5-year overall survival rate for the entire cohort was 51% ± 10%. The 5-year progression-free survival rate w...