The serine-threonine kinase, Akt, inhibits cardiomyocyte apoptosis acutely both in vitro and in vivo. However, the effects of chronic Akt activation in the heart are unknown. To address this issue, we generated transgenic mice (TG؉) with cardiac-specific expression of a constitutively active mutant of Akt (myr-Akt) driven by the myosin heavy chain-␣ promoter. Three TG؉ founders (9 -19 weeks) died suddenly with massive cardiac dilatation. Two viable TG؉ lines (TG564 and TG20) derived from independent founders demonstrated cardiac-specific transgene expression as well as activation of Akt and p70S6 kinase. TG564 (n ‫؍‬ 19) showed cardiac hypertrophy with a heart/body weight ratio 2.3-fold greater than littermates (n ‫؍‬ 17, p < 0.005). TG20 (n ‫؍‬ 18) had less marked cardiac hypertrophy with a heart/body weight ratio 1.6-fold greater than littermates (n ‫؍‬ 17, p < 0.005). Isolated TG564 myocytes were also hypertrophic with surface areas 1.7-fold greater than littermates (p < 0.000001). Echocardiograms in both lines demonstrated concentric hypertrophy and preserved systolic function. After ischemia-reperfusion, TG؉ had a 50% reduction in infarct size versus TG؊ (17 ؎ 3% versus 34 ؎ 4%, p < 0.001). Thus, chronic Akt activation is sufficient to cause a spectrum of phenotypes from moderate cardiac hypertrophy with preserved systolic function and cardioprotection to massive cardiac dilatation and sudden death.

BackgroundIt is challenging to conduct and quickly disseminate findings from in-depth qualitative analyses, which can impede timely implementation of interventions because of its time-consuming methods. To better understand tradeoffs between the need for actionable results and scientific rigor, we present our method for conducting a framework-guided rapid analysis (RA) and a comparison of these findings to an in-depth analysis of interview transcripts.MethodsSet within the context of an evaluation of a successful academic detailing (AD) program for opioid prescribing in the Veterans Health Administration, we developed interview guides informed by the Consolidated Framework for Implementation Research (CFIR) and interviewed 10 academic detailers (clinical pharmacists) and 20 primary care providers to elicit detail about successful features of the program. For the RA, verbatim transcripts were summarized using a structured template (based on CFIR); summaries were subsequently consolidated into matrices by participant type to identify aspects of the program that worked well and ways to facilitate implementation elsewhere. For comparison purposes, we later conducted an in-depth analysis of the transcripts. We described our RA approach and qualitatively compared the RA and deductive in-depth analysis with respect to consistency of themes and resource intensity.ResultsIntegrating the CFIR throughout the RA and in-depth analysis was helpful for providing structure and consistency across both analyses. Findings from the two analyses were consistent. The most frequently coded constructs from the in-depth analysis aligned well with themes from the RA, and the latter methods were sufficient and appropriate for addressing the primary evaluation goals. Our approach to RA was less resource-intensive than the in-depth analysis, allowing for timely dissemination of findings to our operations partner that could be integrated into ongoing implementation.ConclusionsIn-depth analyses can be resource-intensive. If consistent with project needs (e.g., to quickly produce information to inform ongoing implementation or to comply with a policy mandate), it is reasonable to consider using RA, especially when faced with resource constraints. Our RA provided valid findings in a short timeframe, enabling identification of actionable suggestions for our operations partner.Electronic supplementary materialThe online version of this article (10.1186/s13012-019-0853-y) contains supplementary material, which is available to authorized users.

Hepatocytes are extensively used in studies of gene regulation but cannot be maintained in long-term culture as replicating, differentiated cells while remaining nontumorigenic. We have derived two hepatocyte lines from livers of transgenic mice overexpressing transforming growth factor a, a potent hepatocyte mitogen, which overcome these limitations. The transgenic hepatocytes were maintained for .2 months in serum-supplemented primary culture and gave rise to cell lines, of which two (AML12 and AML14) have been cultured for >1.5 years (>80 passages). Both lines have typical hepatocyte features such as peroxisomes and bile canalicular-like structures, do not grow in soft agar, and are nontumorigenic in nude mice. Like normal hepatocytes, AML cells express high levels of mRNA for serum (albumin, al-antitrypsin, and transferrin) and gap junction (connexins 26 and 32) proteins, secrete albumin, and contain solely isozyme 5 of lactate dehydrogenase. After extensive passaging, AML12 cells continue to strongly coexpress hepatocyte connexin mRNAs but do not display nonparenchymal cell markers. Although mRNA levels for some serum proteins progressively fall, high expression in late AML12 cultures may be regained by passage in serum-free medium. The AML14 line loses expression of both differentiated markers and transgene mRNA with extended passaging, and hepatocytic traits are only partially restored by passage in serum-free medium. These differentiated, nontumorigenic cell lines should serve as models in which to study hepatocyte growth and differentiation.Mammalian hepatocytes have long been used to investigate mechanisms of cell growth, differentiation, and tumorigenesis and as vectors for gene therapy. These studies have been hampered because dissociated hepatocytes rapidly lose their cell-specific functions, are short-lived, and have a limited ability to replicate in culture. Longer-term differentiated cultures can be maintained with specialized media and substrata or by coculture with nonparenchymal cells, but under these conditions the cells remain nonproliferative (1-3).Hepatocyte lines which express some tissue-specific markers have been propagated in vitro from hepatocellular tumors. More recently, well-differentiated lines have been derived by introducing viral oncogenes into hepatocytes. While useful, these lines have the drawback of either being fully transformed or undergoing transformation with repeated passaging (3)(4)(5)(6).Transforming growth factor a (TGFa) is a polypeptide that regulates normal growth in epithelial tissues, and its overproduction in cells possessing epidermal growth factor receptors (EGFRs) is often correlated with malignant transformation (7-10). TGFa is expressed in the liver during embryogenesisThe publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact. and transiently increases during liver regeneration after partial hepa...

AimsFunctional mitral regurgitation (FMR) contributes to morbidity and mortality in heart failure (HF) patients. The aim of this study was to determine whether percutaneous mitral annuloplasty could safely and effectively reduce FMR and yield durable long-term clinical benefit.Methods and resultsThe impact of mitral annuloplasty (Carillon Mitral Contour System) was evaluated in HF patients with at least moderate FMR. Patients in whom the device was placed then acutely recaptured for clinical reasons served as a comparator group. Quantitative measures of FMR, left ventricular (LV) dimensions, New York Heart Association (NYHA) class, 6 min walk distance (6MWD), and quality of life were assessed in both groups up to 12 months. Safety and key functional data were assessed in the implanted cohort up to 24 months. Thirty-six patients received a permanent implant; 17 had the device recaptured. The 30-day major adverse event rate was 1.9%. In contrast to the comparison group, the implanted cohort demonstrated significant reductions in FMR as represented by regurgitant volume [baseline 34.5 ±11.5 mL to 17.4 ±12.4 mL at 12 months (P < 0.001)]. There was a corresponding reduction in LV diastolic volume [baseline 208.5 ±62.0 mL to 178.9 ±48.0 mL at 12 months (P =0.015)] and systolic volume [baseline 151.8 ±57.1 mL to 120.7 ±43.2 mL at 12 months (P =0.015)], compared with progressive LV dilation in the comparator. The 6MWD markedly improved for the implanted patients by 102.5 ±164 m at 12 months (P =0.014) and 131.9 ±80 m at 24 months (P < 0.001).ConclusionPercutaneous reduction of FMR using a coronary sinus approach is associated with reverse LV remodelling. Significant clinical improvements persisted up to 24 months.

Background Heart failure (HF) is an important public health concern particularly among persons over 65 years of age. Women and African Americans are critically understudied populations that carry a sizeable portion of the HF burden. Limited normative and prognostic data exist regarding measures of cardiac structure, diastolic function, and novel measures of systolic deformation in older adults living in the community. Methods and Results The Atherosclerosis Risk in Communities (ARIC) study is a large, predominantly biracial NHLBI-sponsored epidemiologic cohort study. Between 2011 and 2013, approximately 6,000 surviving participants, now in their seventh to ninth decade of life, are expected to return for a 5th study visit during which comprehensive 2D, Doppler, tissue Doppler, and speckle-tracking echocardiography will be performed uniformly in all cohort clinic visit participants. The following objectives will be addressed: (1) to characterize cardiac structural and functional abnormalities among the elderly and determine how these differ by gender and race/ethnicity, (2) determine the relationship between ventricular and vascular abnormalities, and (3) prospectively examine the extent to which these non-invasive measures associate with incident HF. Conclusions We describe the design, imaging acquisition and analysis methods, and quality assurance metrics for echocardiography in Visit 5 of the ARIC cohort. A better understanding of the differences in cardiac structure and function through the spectrum of HF stages in the elderly generally, and between genders and racial/ethnic groups specifically, will deepen our understanding of the pathophysiology driving HF progression in these at-risk populations and may inform novel prevention or therapeutic strategies.

ObjectiveFunctional (or secondary) mitral regurgitation (FMR) is associated with greater morbidity and worse outcomes in patients with congestive heart failure (CHF) and cardiomyopathy. The Carillon® Mitral Contour System® is a coronary sinus-based percutaneous therapy to reduce FMR. We evaluated the safety and efficacy of a modified version of the Carillon device in the treatment of patients with cardiomyopathy and FMR.Methods36 patients with CHF, depressed left ventricular function (ejection fraction <40%) and at least moderate FMR underwent the Carillon device implant.ResultsThere was 1 major adverse event within 30 days—a death (not device related)—occurring 17 days after the implant. Reductions in FMR and improvements in functional class and 6 min walk tests were seen, similar to prior studies. Device fractures in the high strain region of the proximal anchor (seen in prior studies) were not seen in this study.ConclusionsThe modified Carillon device was associated with improvements in clinical and echocardiographic parameters in treating patients with FMR, while successfully addressing the issue of anchor fracture. This version of the Carillon device will be used in a blinded randomised trial of symptomatic patients with FMR.

To investigate the role of endothelial nitric oxide synthase (NOS3) in left ventricular (LV) remodeling induced by chronic pressure overload, the impact of transverse aortic constriction (TAC) on LV structure and function was compared in wild-type (WT) and NOS3-deficient (NOS3(-/-)) mice. Before TAC, LV wall thickness, mass, and fractional shortening were similar in the two mouse strains. Twenty-eight days after TAC, both WT and NOS3(-/-) mice had increased LV wall thickness and mass as well as decreased fractional shortening. Although the pressure gradient across the TAC was similar in both strains of mice 28 days after TAC, LV mass and posterior wall thickness were greater in NOS3(-/-) than in WT mice, whereas fractional shortening and the maximum rate of developed LV pressure were less. Diastolic function, as measured by the time constant of isovolumic relaxation and the maximum rate of LV pressure decay, was impaired to a greater extent in NOS3(-/-) than in WT mice. The degree of myocyte hypertrophy and LV fibrosis was greater in NOS3(-/-) than in WT mice at 28 days after TAC. Mortality was greater in NOS3(-/-) than in WT mice 28 days after TAC. Long-term administration of hydralazine normalized the blood pressure and prevented the LV dilation in NOS3(-/-) mice but did not prevent the LV hypertrophy, dysfunction, and fibrosis associated with NOS3 deficiency after TAC. These results suggest that the absence of NOS3 augments LV dysfunction and remodeling in a murine model of chronic pressure overload.

Expression of transforming growth factor-beta s (TGF-beta s) 1-3 was studied in normal liver and during liver regeneration after partial hepatectomy in the rat to determine whether each of these isoforms might be involved in hepatocyte growth in vivo. Expression of the mRNAs for all three TGF-beta isoforms increases in the regenerating liver. In addition, the levels of expression of the mRNAs for several extracellular matrix proteins, including fibronectin, vitronectin, laminin, and collagen, also increase in the regenerating liver. Immunohistochemical staining analysis shows a similar distribution of all three TGF-beta s in normal and regenerating liver; however, in both tissues, the level of expression of TGF-beta 1 is 8- to 10-fold higher than that of TGF-beta 2 as determined by sandwich enzyme-linked immunosorbent assay. Expression of all three TGF-beta mRNAs is restricted to liver nonparenchymal cells. Although hepatocytes from normal and regenerating livers do not synthesize TGF-beta, they are sensitive to inhibition of growth by all three TGF-beta isoforms. Hepatocytes from regenerating livers are capable of activating latent TGF-beta 1 complexes in vitro, whereas normal hepatocytes are not. The different TGF-beta isoforms may function in an inhibitory paracrine mechanism that is activated during liver regeneration and may also regulate the synthesis of extracellular matrix components in the regenerating liver.