Citations

Obesity is often regarded as the primary cause of metabolic syndrome. However, many lines of evidence suggest that obesity may develop as a protective mechanism against tissue damage during caloric surplus and that it is only when the maximum fat accumulation capacity is reached and fatty acid spillover occurs into to peripheral tissues that metabolic diseases develop. In this regard, identifying the molecular mechanisms that modulate adipocyte fat accumulation and fatty acid spillover is imperative. Here we identify the deleted in breast cancer 1 (DBC1) protein as a key regulator of fat storage capacity of adipocytes. We found that knockout (KO) of DBC1 facilitated fat cell differentiation and lipid accumulation and increased fat storage capacity of adipocytes in vitro and in vivo. This effect resulted in a “healthy obesity” phenotype. DBC1 KO mice fed a high-fat diet, although obese, remained insulin sensitive, had lower free fatty acid in plasma, were protected against atherosclerosis and liver steatosis, and lived longer. We propose that DBC1 is part of the molecular machinery that regulates fat storage capacity in adipocytes and participates in the “turn-off” switch that limits adipocyte fat accumulation and leads to fat spillover into peripheral tissues, leading to the deleterious effects of caloric surplus.

BACKGROUND: The mechanism between ventilator-induced lung injury (VILI) and multiple organ injury is unclear. The aim of our study was to investigate the mechanisms of VILI-induced distal organ injury. METHODS: VILI was induced in rat lungs with high tidal volume (V T ) ventilation of 40 mL/kg for 6 h. Rats with low V T ventilation of 6 mL/kg served as controls. Inflammatory and apoptotic indices in lung and distal organs were assessed. RESULTS: VILI increased lung weight, airway pressure, inflammation, and apoptotic pathologic changes without hemodynamic changes. The white blood cell count and the levels of H 2 O 2 , interleukin-1β (IL-1β), tumor necrosis factor alpha, and macrophage inflammatory protein-2 in bronchoalveolar lavage fluid were higher in the VILI group compared with the control group. H 2 O 2 , IL-1β, and tumor necrosis factor alpha in blood from the left ventricle were up-regulated. H 2 O 2 , IL-1β, tumor necrosis factor alpha, macrophage inflammatory protein-2, c-Jun N-terminal kinase, p38, nuclear factor kappa B, and caspase-3 in lung, heart, liver, and kidney tissues in the VILI group were up-regulated. Furthermore, the apoptotic score for the kidneys was higher than those for other distal organs in the VILI group. CONCLUSIONS: High V T ventilation induces VILI and is associated with inflammation and apoptosis in distal organs. Up-regulation of reactive oxygen species and cytokines in VILI is associated with systemic inflammatory responses. Kidney tissue appears to be more vulnerable than heart and liver tissues following VILI.

Abstract Objectives Drug repurposing, which finds new indications for existing drugs, has received great attention recently. The goal of our work is to assess the feasibility of using electronic health records (EHRs) and automated informatics methods to efficiently validate a recent drug repurposing association of metformin with reduced cancer mortality. Methods By linking two large EHRs from Vanderbilt University Medical Center and Mayo Clinic to their tumor registries, we constructed a cohort including 32 415 adults with a cancer diagnosis at Vanderbilt and 79 258 cancer patients at Mayo from 1995 to 2010. Using automated informatics methods, we further identified type 2 diabetes patients within the cancer cohort and determined their drug exposure information, as well as other covariates such as smoking status. We then estimated HRs for all-cause mortality and their associated 95% CIs using stratified Cox proportional hazard models. HRs were estimated according to metformin exposure, adjusted for age at diagnosis, sex, race, body mass index, tobacco use, insulin use, cancer type, and non-cancer Charlson comorbidity index. Results Among all Vanderbilt cancer patients, metformin was associated with a 22% decrease in overall mortality compared to other oral hypoglycemic medications (HR 0.78; 95% CI 0.69 to 0.88) and with a 39% decrease compared to type 2 diabetes patients on insulin only (HR 0.61; 95% CI 0.50 to 0.73). Diabetic patients on metformin also had a 23% improved survival compared with non-diabetic patients (HR 0.77; 95% CI 0.71 to 0.85). These associations were replicated using the Mayo Clinic EHR data. Many site-specific cancers including breast, colorectal, lung, and prostate demonstrated reduced mortality with metformin use in at least one EHR. Conclusions EHR data suggested that the use of metformin was associated with decreased mortality after a cancer diagnosis compared with diabetic and non-diabetic cancer patients not on metformin, indicating its potential as a chemotherapeutic regimen. This study serves as a model for robust and inexpensive validation studies for drug repurposing signals using EHR data.

As part of its Healthy Aging & Independent Living (HAIL) initiative, Mayo Clinic Center for Innovation (CFI) examined the patient experience regarding the decision to receive a ventricular assistive device (VAD) implant, and patients’ quality of life after the surgery. As health care technology continues to develop, more people will be living longer, fuller lives with the assistance of wearable/implantable medical devices such as the VAD. This case study examined and made recommendations on ways for the Mayo Clinic VAD Committee to improve the program.

BackgroundTricuspid annular plane systolic excursion measured by M‐mode (MM‐TAPSE) has been validated as a marker of right ventricular systolic performance. A similar measurement by 2D imaging (2D‐TAPSE) can be obtained. We sought to determine the correlation and strength of agreement between MM‐TAPSE and 2D‐TAPSE in children.MethodsEchocardiographic studies performed for clinical indications were reviewed retrospectively. All consecutive subjects ≤18 years of age were included. The cohort was divided into those with normal echocardiographic findings and those with disorders affecting the right ventricle. Digitally recorded images were analyzed for both MM‐TAPSE and 2D‐TAPSE. Measurements of 2D‐TAPSE were made in an apical four‐chamber view, from the tricuspid valve annulus to a consistent point at the apex of the imaging sector at end‐diastole and end‐systole, with the difference representing the 2D‐TAPSE value.ResultsA total of 329 subjects (mean age 9.0 ± 6.1 years) met entry criteria. Correlation coefficient between MM‐TAPSE and 2D‐TAPSE was 0.90. Bland–Altman analysis showed agreement between the two methods to be within 1.2 ± 2.6 mm (mean percentage difference of 6.5%). About 1 mm difference between MM‐TAPSE and 2D‐TAPSE was consistently observed in all diagnostic subgroups, and across all age categories.ConclusionMM‐TAPSE and 2D‐TAPSE correlate strongly, with 2D‐TAPSE being consistently about 1 mm less than values obtained by the M‐mode technique. We conclude that 2D‐TAPSE can provide a reliable alternative to MM‐TAPSE to quantitatively measure right ventricular systolic function and may be especially useful in situations where retrospective comparisons are sought.

Endothelial progenitor cells (EPCs) participate in renal repair, but their number and function may be impaired by exposure to cardiovascular risk factors. The number of circulating EPCs is decreased in essential and renovascular hypertensive patients, but the effects of hypertension on EPC function are incompletely understood. We hypothesized that EPC function was preserved under well-controlled conditions in treated hypertensive patients. Patients with atherosclerotic renal artery stenosis (ARAS; n=22) or essential hypertension (n=24) were studied during controlled sodium intake and antihypertensive regimen. Late-outgrowth EPCs were isolated from the inferior vena cava (IVC) and renal vein blood of ARAS and essential hypertension patients and a peripheral vein of matched normotensive controls (n=18). The angiogenic function of EPCs was assessed in vitro, and multidetector computed tomography was used to measure single-kidney hemodynamics and function in ARAS and essential hypertension patients. Inflammatory biomarkers and EPC homing signal levels and renal release were calculated. Inferior vena cava and renal vein–obtained EPC function were similar in ARAS and essential hypertension patients and comparable to that in normal controls (tube length, 171.86±16.846, 191.09±14.222, 174.925±19.774 μm, respectively). Function of renal vein–obtained EPCs directly correlated with stenotic kidney glomerular filtration rate, EPC homing factors, and anti-inflammatory mediator levels in ARAS patients. Therefore, EPC function was relatively preserved in ARAS patients, although it directly correlated with renal function. Adequate EPC function supports the feasibility of using autologous EPCs as a therapeutic option in essential and renovascular hypertensive patients. Homing signals and inflammatory mediators may potentially regulate EPC angiogenic function.