Relation of Cigarette Smoking and Heart Failure in Adults ≥65 Years of Age (From the Cardiovascular Health Study).

Cigarette smoking is associated with adverse cardiac outcomes, including incident heart failure (HF). However, key components of potential pathways from smoking to HF have not been evaluated in older adults. In a community-based study, we studied cross-sectional associations of smoking with blood and imaging biomarkers reflecting mechanisms of cardiac disease. Serial nested, multivariable Cox models were used to determine associations of smoking with HF, and to assess the influence of biochemical and functional (cardiac strain) phenotypes on these associations. Compared with never smokers, smokers had higher levels of inflammation (C-reactive protein and interleukin-6), cardiomyocyte injury (cardiac troponin T [hscTnT]), myocardial "stress"/fibrosis (soluble suppression of tumorigenicity 2 [sST2], galectin 3), and worse left ventricle systolic and diastolic function. In models adjusting for age, gender, and race (DEMO) and for clinical factors potentially in the causal pathway (CLIN), smoking exposures were associated with C-reactive protein and interleukin-6, sST2, hscTnT, and with N-terminal pro-brain natriuretic protein (in Whites). In DEMO adjusted models, the cumulative burden of smoking was associated with worse left ventricle systolic strain. Current smoking and former smoking were associated with HF in DEMO models (hazard ratio 1.41, 95% confidence interval 1.22 to 1.64 and hazard ratio 1.14, 95% confidence interval 1.03 to 1.25, respectively), and with current smoking after CLIN adjustment. Adjustment for time-varying myocardial infarction, inflammation, cardiac strain, hscTnT, sST2, and galectin 3 did not materially alter the associations. Smoking was associated with HF with preserved and decreased ejection fraction. In conclusion, in older adults, smoking is associated with multiple blood and imaging biomarker measures of pathophysiology previously linked to HF, and to incident HF even after adjustment for clinical intermediates.

Geographical affiliation with top 10 NIH-funded academic medical centers and differences between mortality from cardiovascular disease and cancer.

Community engagement and rapid translation of findings for the benefit of patients has been noted as a major criterion for NIH decisions regarding allocation of funds for research priorities. We aimed to examine whether the presence of top NIH-funded institutions resulted in a benefit on the cardiovascular and cancer mortality of their local population. METHODS AND RESULTS: Based on the annual NIH funding of every academic medical from 1995 through 2014, the top 10 funded institutes were identified and the counties where they were located constituted the index group. The comparison group was created by matching each index county to another county which lacks an NIH-funded institute based on sociodemographic characteristics. We compared temporal trends of age-standardized cardiovascular mortality between the index counties and matched counties and states. This analysis was repeated for cancer mortality as a sensitivity analysis. From 1980 through 2014, the annual cardiovascular mortality rates declined in all counties. In the index group, the average decline in cardiovascular mortality rate was 51.5 per 100,000 population (95% CI, 46.8-56.2), compared to 49.7 per 100,000 population (95% CI, 45.9-53.5) in the matched group (P = .27). Trends in cardiovascular mortality of the index counties were similar to the cardiovascular mortality trends of their respective states. Cancer mortality rates declined at higher rates in counties with top NIH-funded medical centers (P < .001). CONCLUSIONS: Cardiovascular mortality rates have decreased with no apparent incremental benefit for communities with top NIH-funded institutions, underscoring the need for an increased focus on implementation science in cardiovascular diseases.

Microreactor array device.

We report a device to fill an array of small chemical reaction chambers (microreactors) with reagent and then seal them using pressurized viscous liquid acting through a flexible membrane. The device enables multiple, independent chemical reactions involving free floating intermediate molecules without interference from neighboring reactions or external environments. The device is validated by protein expressed in situ directly from DNA in a microarray of ~10,000 spots with no diffusion during three hours incubation. Using the device to probe for an autoantibody cancer biomarker in blood serum sample gave five times higher signal to background ratio compared to standard protein microarray expressed on a flat microscope slide. Physical design principles to effectively fill the array of microreactors with reagent and experimental results of alternate methods for sealing the microreactors are presented.

Neutral and weakly nonneutral sequence variants may define individuality.

Large-scale computational analyses of the growing wealth of genome-variation data consistently tell two distinct stories. The first is expected: coding variants reported in disease-related databases significantly alter the function of affected proteins. The second is surprising: the genomes of healthy individuals appear to carry many variants that are predicted to have some effect on function. As long as the complete experimental analysis of all human genome variants remains impossible, computational methods, such as PolyPhen, SNAP, and SIFT, might provide important insights. These methods capture the effects of particular variants very well and can highlight trends in populations of variants. Diseases are, arguably, extreme phenotypic variations and are often attributable to one or a few severely functionally disruptive variants. Our findings suggest a genomic basis of the different nondisease phenotypes. Prediction methods indicate that variants in seemingly healthy individuals tend to be neutral or weakly disruptive for protein molecular function. These variant effects are predicted to be largely either experimentally undetectable or are not deemed significant enough to be published. This may suggest that nondisease phenotypes arise through combinations of many variants whose effects are weakly nonneutral (damaging or enhancing) to the molecular protein function but fall within the wild-type range of overall physiological function.

Identification of amino acids critical for the cytotoxicity of Shiga toxin 1 and 2 in Saccharomyces cerevisiae.

Shiga toxins (Stx1 and Stx2) are produced by E. coli O157:H7, which is a leading cause of foodborne illness. The A subunits of Stx1 (Stx1A) and Stx2 (Stx2A) are ribosome inactivating proteins (RIPs) that inhibit translation by removing an adenine from the highly conserved α-sarcin ricin loop (SRL) of the large rRNA. Here, we used mutagenesis in Saccharomyces cerevisiae to identify residues critical for cytotoxicity of Stx1A and Stx2A. The A subunits depurinated the SRL, inhibited translation and caused apoptotic-like cell death in yeast. Single mutations in Asn75, Tyr77, Glu167 and Arg176 reduced the cytotoxicity of both toxins around 10-fold. However, Asn75 and Tyr77 were more critical for the depurination activity of Stx2A, while Arg176 was more critical for the depurination activity of Stx1A. The crystal structures of the two proteins lack electron density for some surface loops, including one which is adjacent to the active site in both molecules. Modeling these loops changed neither the secondary nor the tertiary structures of the rest of the protein. Analysis of solvent accessible surface areas indicated that Asn75 and Tyr77 are more exposed in Stx2A, while Arg176 is more exposed in Stx1A, indicating that residues with higher surface exposure were more critical for enzymatic activity. Double mutations at Glu167 and Arg176 eliminated the depurination activity and cytotoxicity of both toxins. C-terminal deletions of A chains eliminated cytotoxicity of both toxins, but showed functional differences. Unlike Stx1A, cytotoxicity of Stx2A was lost before its ability to depurinate ribosomes. These results identify residues that affect enzymatic activity and cytotoxicity of Stx1A and Stx2A differently and demonstrate that the function of these residues can be differentiated in yeast. The extent of ribosome depurination and translation inhibition did not correlate with the extent of cell death, indicating that depurination of the SRL and inhibition of translation are not entirely responsible for cell death.

Role of the helical domain in fatty acid transfer from adipocyte and heart fatty acid-binding proteins to membranes: analysis of chimeric proteins.

The adipocyte and heart fatty acid-binding proteins (A- and HFABP) are members of a lipid-binding protein family with a beta-barrel body capped by a small helix-turn-helix motif. Both proteins are hypothesized to transport fatty acid (FA) to phospholipid membranes through a collisional process. Previously, we suggested that the helical domain is particularly important for the electrostatic interactions involved in this transfer mechanism (Herr, F. M., Aronson, J., and Storch, J. (1996) Biochemistry 35, 1296-1303; and Liou, H.-L., and Storch, J. (2001) Biochemistry 40, 6475-6485). Despite their using qualitatively similar FA transfer mechanisms, differences in absolute transfer rates as well as regulation of transfer from AFABP versus HFABP, prompted us to consider the structural determinants that underlie these functional disparities. To determine the specific elements underlying the functional differences between AFABP and HFABP in FA transfer, two pairs of chimeric proteins were generated. The first and second pairs had the entire helical domain and the first alpha-helix exchanged between A- and HFABP, respectively. The transfer rates of anthroyloxy-labeled fatty acid from proteins to small unilamellar vesicles were compared with the wild type AFABP and HFABP. The results suggest that the alphaII-helix is important in determining the absolute FA transfer rates. Furthermore, the alphaI-helix appears to be particularly important in regulating protein sensitivity to the negative charge of membranes. The alphaI-helix of HFABP and the alphaII-helix of AFABP increased the sensitivity to anionic vesicles; the alphaI-helix of AFABP and alphaII-helix of HFABP decreased the sensitivity. The differential sensitivities to negative charge, as well as differential absolute rates of FA transfer, may help these two proteins to function uniquely in their respective cell types.