Citations

Context: Skeletal muscle from sedentary older adults exhibits reduced mitochondrial abundance and oxidative capacity. Objective: The primary objective was to determine whether 8 weeks of combined training (CT) has a more robust effect than endurance training (ET) or resistance training (RT) on mitochondrial physiology in healthy young (18–30 years) and older (≥65 years) adults. Intervention: Thirty-four young and 31 older adults were randomly assigned to 8 weeks of ET, RT, and control/CT. Control subjects completed 8 weeks of no exercise (control) followed by 8 weeks of CT. Body composition, skeletal muscle strength, and peak oxygen uptake were measured before and after the intervention. Vastus lateralis muscle biopsy samples were obtained before and 48 hours after the intervention. Mitochondrial physiology was evaluated by high-resolution respirometry and expression of mitochondrial proteins and transcription factors by quantitative PCR and immunoblotting. Results: ET and CT significantly increased oxidative capacity and expression of mitochondrial proteins and transcription factors. All training modalities improved body composition, cardiorespiratory fitness, and skeletal muscle strength. CT induced the most robust improvements in mitochondria-related outcomes and physical characteristics despite lower training volumes for the ET and RT components. Importantly, most of the adaptations to training occurred independent of age. Conclusion: Collectively, these results demonstrate that both ET and CT increase muscle mitochondrial abundance and capacity although CT induced the most robust improvements in the outcomes measured. In conclusion, CT provides a robust exercise regimen to improve muscle mitochondrial outcomes and physical characteristics independent of age.

Abstract Background: Research biobanks collect biologic samples and health information. Previous work shows that biobank participants desire general study updates, but preferences about the method or frequency of these communications have not been explored. Thus, we surveyed participants in a long-standing research biobank. Methods: Eligible participants were drawn from a study of patients with personal/family history suggestive of Cowden syndrome, a poorly recognized inherited cancer syndrome. Participants gave blood samples and access to medical records and received individual results but had no other study interactions. The biobank had 3,618 participants at sampling. Survey eligibility included age ≥18 years, enrollment within the biobank's first 5 years, normal PTEN analysis, and contiguous U.S. address. Multivariate logistic regression analyses identified predictors of participant interest in Internet-based versus offline methods and methods allowing participant–researcher interaction versus one-way communication. Independent variables were narrowed by independent Pearson correlations by cutoff P < 0.2, with P < 0.02 considered significant. Results: Surveys were returned from 840 of 1,267 (66%) eligible subjects. Most (97%) wanted study updates, with 92% wanting updates at least once a year. Participants preferred paper (66%) or emailed (62%) newsletter methods, with 95% selecting one of these. Older, less-educated, and lower-income respondents strongly preferred offline approaches (P < 0.001). Most (93%) had no concerns about receiving updates and 97% were willing to provide health updates to researchers. Conclusion: Most participants were comfortable receiving and providing updated information. Demographic factors predicted communication preferences. Impact: Researchers should make plans for ongoing communication early in study development and funders should support the necessary infrastructure for these efforts. Cancer Epidemiol Biomarkers Prev; 24(4); 708–12. ©2015 AACR.

Background In epidemiologic studies, obesity has been associated with reduced natriuretic peptide ( NP ) concentrations. Reduced NP production could impair the ability of obese individuals to respond to salt loads, increasing the risk of hypertension and other disorders. We hypothesized that weight loss enhances NP production before and after salt loading. Methods and Results We enrolled 15 obese individuals (mean BMI 45±5.4 kg/m 2 ) undergoing gastric bypass surgery. Before and 6 months after surgery, subjects were admitted to the clinical research center and administered a large‐volume intravenous saline challenge. Echocardiography and serial blood sampling were performed. From the pre‐operative visit to 6 months after surgery, subjects had a mean BMI decrease of 27%. At the 6‐month visit, N‐terminal pro‐atrial NP (Nt‐pro ANP ) levels were 40% higher before, during, and after the saline infusion, compared with levels measured at the same time points during the pre‐operative visit ( P <0.001). The rise in Nt‐pro‐ ANP induced by the saline infusion (≈50%) was similar both before and after surgery (saline, P <0.001; interaction, P =0.2). Similar results were obtained for BNP and Nt‐pro BNP ; resting concentrations increased by 50% and 31%, respectively, after gastric bypass surgery. The increase in NP concentrations after surgery was accompanied by significant decreases in mean arterial pressure ( P =0.004) and heart rate ( P <0.001), and an increase in mitral annular diastolic velocity ( P =0.02). Conclusion In obese individuals, weight loss is associated with a substantial increase in the “setpoint” of circulating NP concentrations. Higher NP concentrations could contribute to an enhanced ability to handle salt loads after weight loss.

Despite preexisting cytomegalovirus (CMV) immunity, CMV‐seropositive liver transplantation (LT) patients remain at risk of CMV infection. We hypothesized that the pre‐transplant CMV antibody titer correlates with the risk of CMV reactivation. We conducted a retrospective study of CMV‐seropositive LT recipients who did not receive anti‐CMV prophylaxis from 2007 to 2013. The pre‐transplant CMV immunoglobulin G (IgG) titer, which was measured with an enzyme‐linked fluorescent immunoassay, was assessed as a risk factor for CMV reactivation with multivariate Cox proportional hazards models. The population consisted of 225 CMV‐seropositive LT patients with a median age of 57 years (interquartile range, 47‐62 years). The CMV titer distributions were as follows: <60 (40%) and ≥60 AU/mL (60%). The Kaplan‐Meier estimates for CMV infection were 17% at 3 months, 18% at 6 months, and 19% at 12 months after transplantation. In a univariate analysis, a marginally significant increased risk of CMV infection was seen in LT recipients with a pre‐transplant CMV IgG titer < 60 AU/mL versus ≥ 60 AU/mL [hazard ratio (HR), 1.79; 95% confidence interval (CI), 0.98‐3.28 (P =0.06)]. This risk was statistically significant in the subgroup of recipients who received allografts from CMV‐seropositive donors [HR, 2.21; 95% CI, 1.15‐4.26 (P =0.02)]. In a multivariate analysis, a pre‐transplant CMV IgG titer < 60 AU/mL was significantly associated with CMV infection [HR, 3.11; 95% CI, 1.60‐6.03 (P < 0.001)]. The other risk factors were high body mass index, donor CMV seropositivity, prolonged cold ischemic time, use of an interleukin‐2 receptor antagonist for induction therapy, and high numbers of post‐transplant infections. A lower pre‐transplant CMV antibody titer is significantly associated with CMV infection after LT. Quantitative measurement of CMV‐specific humoral immunity may have a potential role in improving the CMV prevention strategy in CMV‐seropositive LT recipients.Liver Transpl 21:539–546, 2015. © 2015 AASLD.

WWOX is a gene that spans an extremely large chromosomal region. It is derived from within chromosomal band 16q23.2 which is a region with frequent deletions and other alterations in a variety of different cancers. This chromosomal band also contains the FRA16D common fragile site (CFS). CFSs are chromosomal regions found in all individuals which are highly unstable. WWOX has also been demonstrated to function as a tumor suppressor that is involved in the development of many cancers. Two other highly unstable CFSs, FRA3B (3p14.2) and FRA6E (6q26), also span extremely large genes, FHIT and PARK2, respectively, and these two genes are also found to be important tumor suppressors. There are a number of interesting similarities between these three large CFS genes. In spite of the fact that they are derived from some of the most unstable chromosomal regions in the genome, they are found to be highly evolutionarily conserved and the chromosomal region spanning the mouse homologs of both WWOX and FHIT are also CFSs in mice. Many of the other CFSs also span extremely large genes and many of these are very attractive tumor suppressor candidates. WWOX is therefore a member of a very interesting family of very large CFS genes.

The current system granting liver transplant candidates with hepatocellular carcinoma (HCC) additional Model for End‐Stage Liver Disease (MELD) points is controversial due to geographic disparity and uncertainty regarding optimal prioritization of candidates. The current national policy assigns a MELD exception score of 22 immediately upon listing of eligible patients with HCC. The aim of this study was to evaluate the potential effects of delays in granting these exception points on transplant rates for HCC and non‐HCC patients. We used Scientific Registry of Transplant Recipients data and liver simulated allocation modeling software and modeled (1) a 3‐month delay before granting a MELD exception score of 25, (2) a 6‐month delay before granting a score of 28, and (3) a 9‐month delay before granting a score of 29. Of all candidates waitlisted between January 1 and December 31, 2010 (n = 28,053), 2773 (9.9%) had an HCC MELD exception. For HCC candidates, transplant rates would be 108.7, 65.0, 44.2, and 33.6 per 100 person‐years for the current policy and for 3‐, 6‐, and 9‐month delays, respectively. Corresponding rates would be 30.1, 32.5, 33.9, and 34.8 for non‐HCC candidates. Conclusion: A delay of 6‐9 months would eliminate the geographic variability in the discrepancy between HCC and non‐HCC transplant rates under current policy and may allow for more equal access to transplant for all candidates. (Hepatology 2015;61:1643–1650)