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.

The prediction of visceral fat by dual-energy X-ray absorptiometry in the elderly: a comparison with computed tomography and anthropometry.

Abstract: Introduction: Effective methods for assessing visceral fat are important to investigate the role of visceral fat for the increased health risks in obesity. Techniques for direct measurement of soft tissue composition such as CT or MRI are expensive, time-consuming or require a relatively high radiation dose. Simple anthropometric methods, such as waist-to-hip ratio, waist circumference or sagittal diameter are widely used. However, these methods cannot differentiate between visceral and subcutaneous fat and are less accurate. The aim of the present study is to investigate whether the dual-energy X-ray absorptiometry (DXA) method, possibly combined with anthropometry, offers a good alternative to CT for the prediction of visceral fat in the elderly. Methods: Subjects were participants in the Health ABC-study, a cohort study of black and white men and women aged 70–79, investigating the effect of weight-related health conditions on disablement. Total body fat and trunk fat were measured by DXA using a Hologic QDR 1500. A 10 mm CT scan at the L4–L5 level was acquired to measure visceral fat and total abdominal fat. Weight, height, sagittal diameter and waist circumference were measured using standard methods. Fat in a manually defined DXA subregion (4 cm slice at the top of iliac crest) at the abdomen was calculated in a sub-group of participants (n=150; 50% male; 45.3% Afro-American/54.7% Caucasian, age 70–79 y). This subregion, the standard trunk region and total fat were used as indicators of visceral fat. Results: Total abdominal fat by DXA (subregion) was strongly correlated with total abdominal fat by CT (r ranging from 0.87 in white men to 0.98 in black women). The DXA subregion underestimated total abdominal fat by 10% compared to the CT slice. The underestimation by DXA was seen especially in people with less abdominal fat. The association of visceral fat by CT with the DXA subregion (r=0.66, 0.78, 0.79 and 0.65 for white and black men and women, respectively) was comparable with the association of the CT measure with the sagittal diameter (r=0.74, 0.70, 0.84 and 0.68). Combining DXA measurements with anthropometry gave only limited improvement for the prediction of visceral fat by CT compared to univariate models (maximal increase of r2 4%). Conclusion: DXA is a good alternative to CT for predicting total abdominal fat in an elderly population. For the prediction of visceral fat the sagittal diameter, which has a practical advantage compared to DXA, is just as effective.

Trends in sun exposure knowledge, attitudes, and behaviors : 1986 to 1996

Abstract: Background: The American Academy of Dermatology's national program Melanoma/Skin Cancer Detection and Prevention, developed in response to the rising incidence of invasive melanoma in the United States, has annually during the past decade produced extensive print, radio, and television coverage about the dangers of sun exposure and benefits of sun protection. Objective: We measured the progress achieved in increasing the awareness and knowledge of skin cancer and changing the attitudes, beliefs, and behaviors that affect skin cancer risk. We also describe current sun-related behavior including sunburning, assess the likelihood of practicing sun protection strategies, and provide a baseline against which future changes in sun protection behavior may be evaluated. Methods: A 1996 telephone survey repeated questions used in 1986 to evaluate change and used classifying questions to better define attitudes and behaviors. Results: From 1986 to 1996, the knowledge of the perceived harmful effects of the sun significantly broadened, but the UV exposure behavior as measured by sunburning (30% to 39%) and regular use of a tanning booth (2% to 6%) also increased. There was a decline in the attitude that having a tan was healthy; however, in 1996 having a tan was still considered to enhance appearance, particularly by men. Sunscreen use increased (35% to 53%). Women, younger persons, persons residing in areas with fewer sunny days, and whites were more likely to tan intentionally, but men who lived in the South were more likely to sunburn. Conclusion: During the past decade, the early process of change involving cognitive and emotional activities began. With this study, high-risk population subsets performing specific adverse behavior were identified. In the future, they can be targeted with messages that promote attitudinal and behavioral change. (J Am Acad Dermatol 1997;37:179-86.)

Association of Intensive vs Standard Blood Pressure Control With Cerebral White Matter Lesions.

Abstract: Importance The effect of intensive blood pressure lowering on brain health remains uncertain. Objective To evaluate the association of intensive blood pressure treatment with cerebral white matter lesion and brain volumes. Design, Setting, and Participants A substudy of a multicenter randomized clinical trial of hypertensive adults 50 years or older without a history of diabetes or stroke at 27 sites in the United States. Randomization began on November 8, 2010. The overall trial was stopped early because of benefit for its primary outcome (a composite of cardiovascular events) and all-cause mortality on August 20, 2015. Brain magnetic resonance imaging (MRI) was performed on a subset of participants at baseline (n = 670) and at 4 years of follow-up (n = 449); final follow-up date was July 1, 2016. Interventions Participants were randomized to a systolic blood pressure (SBP) goal of either less than 120 mm Hg (intensive treatment, n = 355) or less than 140 mm Hg (standard treatment, n = 315). Main Outcomes and Measures The primary outcome was change in total white matter lesion volume from baseline. Change in total brain volume was a secondary outcome. Results Among 670 recruited patients who had baseline MRI (mean age, 67.3 [SD, 8.2] years; 40.4% women), 449 (67.0%) completed the follow-up MRI at a median of 3.97 years after randomization, after a median intervention period of 3.40 years. In the intensive treatment group, based on a robust linear mixed model, mean white matter lesion volume increased from 4.57 to 5.49 cm3(difference, 0.92 cm3[95% CI, 0.69 to 1.14]) vs an increase from 4.40 to 5.85 cm3(difference, 1.45 cm3[95% CI, 1.21 to 1.70]) in the standard treatment group (between-group difference in change, −0.54 cm3[95% CI, −0.87 to −0.20]). Mean total brain volume decreased from 1134.5 to 1104.0 cm3(difference, −30.6 cm3[95% CI, −32.3 to −28.8]) in the intensive treatment group vs a decrease from 1134.0 to 1107.1 cm3(difference, −26.9 cm3[95% CI, 24.8 to 28.8]) in the standard treatment group (between-group difference in change, −3.7 cm3[95% CI, −6.3 to −1.1]). Conclusions and Relevance Among hypertensive adults, targeting an SBP of less than 120 mm Hg, compared with less than 140 mm Hg, was significantly associated with a smaller increase in cerebral white matter lesion volume and a greater decrease in total brain volume, although the differences were small. Trial Registration ClinicalTrials.gov Identifier:NCT01206062

Serotoninergic and melatoninergic systems are fully expressed in human skin

Abstract: SPECIFIC AIMSThe skin can metabolize serotonin to N-acetylserotonin (NAS) and possibly melatonin as recently shown in the hamster. We investigated these biosynthetic pathways in normal and pathological human skin, cultured normal and malignant keratinocytes and melanocytes derived from epidermal or follicular compartments, and follicular and dermal fibroblasts.PRINCIPAL FINDINGS1. RT-PCR detection of TPH, AANAT, and HIOMT mRNAsThe 380 bp TPH transcript was present in pituitary, adrenal gland, myometrium, and all samples of normal skin and skin containing basal cell carcinoma; it was also present in cultured normal epidermal and follicular melanocytes, all melanoma cell lines, normal neonatal and adult epidermal and follicular keratinocytes, squamous cell carcinoma cells, and dermal and dermal follicular fibroblasts; the only cells that tested negative for the transcript were HaCaT immortalized keratinocytes. Transcripts of AANAT showed the expected 176 bp fragment spanning exon 2 and 3, and an aberrant 22...

Genetic relatedness and superantigen expression in group A streptococcus serotype M1 isolates from patients with severe and nonsevere invasive diseases.

Abstract: The relatedness of group A streptococcal (GAS) strains isolated from 35 Canadian patients with invasive disease of different severity was investigated by a variety of molecular methods. All patients were infected with M1T1 strains and, based on clinical criteria, were classified as severe (n = 21) and nonsevere (n = 14) invasive GAS infection cases. All the M1 strains studied had the emm1.0 allele and the same streptococcal pyrogenic exotoxin (Spe) genotype, speA(+) speB(+) speC speF(+) speG(+) speH smeZ(+) ssa. All isolates had the same speA allotype, speA2. The randomly amplified polymorphic DNA banding pattern with two different primers was identical for all strains, and pulsed field gel electrophoresis analysis showed that 33 and 30 isolates had identical banding patterns after DNA digestion with SfiI or SmaI, respectively; the nonidentical isolates differed from the main pattern by only one band. A relatively high degree of polymorphism in specific regions of the sic gene was observed among isolates; however, this polymorphism was not associated with disease severity. Likewise, although the phenotypic expression of SpeA, SpeB, and SpeF proteins varied among the M1T1 isolates, there was no correlation between the amount of Spe expressed and disease severity. Importantly, mitogenic and cytokine responses induced by partially purified bacterial culture supernatants containing a mixture of expressed superantigens were very similar for isolates from severe and nonsevere cases (P > 0.1). Together, the data indicate that highly related invasive M1T1 isolates, some indistinguishable, can cause disease of varying severity in different individuals. These findings underscore the contribution of host factors to the outcome of invasive GAS infections.