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1.
Int J Biol Macromol ; 179: 144-153, 2021 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-33667556

RESUMO

L. major acyl carrier protein (ACP) is a mitochondrial protein, involved in fatty acid biosynthesis. The protein is expressed as an apo-protein, and post-translationally modified at Ser 37 by a 4'-Phosphopantetheinyl transferase. Crystal structure of the apo-form of the protein at pH 5.5 suggests a four helix bundle fold, typical of ACP's. However, upon lowering the pH to 5.0, it undergoes a conformational transition from α-helix to ß-sheet, and displays amyloid like properties. When left for a few days at room temperature at this pH, the protein forms fibrils, visible under Transmission electron microscopy (TEM). Using an approach combining NMR, biophysical techniques, and mutagenesis, we have identified a Phe residue present on helix II of ACP, liable for this change. Phosphopantetheinylation of LmACP, or mutation of Phe 45 to the corresponding residue in E. coli ACP (methionine), slows down the conformational change. Conversely, substitution of methionine 44 of E. coli ACP with a phenylalanine, causes enhanced ThT binding. Thus, we demonstrate the unique property of an exposed Phe in inducing, and phophopantetheine in inhibiting amyloidogenesis. Taken together, our study adds L. major acyl carrier protein to the list of ACPs that act as pH sensors.

2.
PLoS One ; 16(2): e0246073, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33561176

RESUMO

BACKGROUND: Insomnia may be a risk factor for cardiovascular disease in HIV (HIV-CVD); however, mechanisms have yet to be elucidated. METHODS: We examined cross-sectional associations of insomnia symptoms with biological mechanisms of HIV-CVD (immune activation, systemic inflammation, and coagulation) among 1,542 people with HIV from the Veterans Aging Cohort Study (VACS) Biomarker Cohort. Past-month insomnia symptoms were assessed by the item, "Difficulty falling or staying asleep?," with the following response options: "I do not have this symptom" or "I have this symptom and…" "it doesn't bother me," "it bothers me a little," "it bothers me," "it bothers me a lot." Circulating levels of the monocyte activation marker soluble CD14 (sCD14), inflammatory marker interleukin-6 (IL-6), and coagulation marker D-dimer were determined from blood specimens. Demographic- and fully-adjusted (CVD risk factors, potential confounders, HIV-related factors) regression models were constructed, with log-transformed biomarker variables as the outcomes. We present the exponentiated regression coefficient (exp[b]) and its 95% confidence interval (CI). RESULTS: We observed no significant associations between insomnia symptoms and sCD14 or IL-6. For D-dimer, veterans in the "Bothers a Lot" group had, on average, 17% higher D-dimer than veterans in the "No Difficulty Falling or Staying Asleep" group in the demographic-adjusted model (exp[b] = 1.17, 95%CI = 1.01-1.37, p = .04). This association was nonsignificant in the fully-adjusted model (exp[b] = 1.09, 95%CI = 0.94-1.26, p = .27). CONCLUSION: We observed little evidence of relationships between insomnia symptoms and markers of biological mechanisms of HIV-CVD. Other mechanisms may be responsible for the insomnia-CVD relationship in HIV; however, future studies with comprehensive assessments of insomnia symptoms are warranted.

3.
BMJ ; 372: n311, 2021 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-33574135

RESUMO

OBJECTIVE: To evaluate whether early initiation of prophylactic anticoagulation compared with no anticoagulation was associated with decreased risk of death among patients admitted to hospital with coronavirus disease 2019 (covid-19) in the United States. DESIGN: Observational cohort study. SETTING: Nationwide cohort of patients receiving care in the Department of Veterans Affairs, a large integrated national healthcare system. PARTICIPANTS: All 4297 patients admitted to hospital from 1 March to 31 July 2020 with laboratory confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and without a history of anticoagulation. MAIN OUTCOME MEASURES: The main outcome was 30 day mortality. Secondary outcomes were inpatient mortality, initiating therapeutic anticoagulation (a proxy for clinical deterioration, including thromboembolic events), and bleeding that required transfusion. RESULTS: Of 4297 patients admitted to hospital with covid-19, 3627 (84.4%) received prophylactic anticoagulation within 24 hours of admission. More than 99% (n=3600) of treated patients received subcutaneous heparin or enoxaparin. 622 deaths occurred within 30 days of hospital admission, 513 among those who received prophylactic anticoagulation. Most deaths (510/622, 82%) occurred during hospital stay. Using inverse probability of treatment weighted analyses, the cumulative incidence of mortality at 30 days was 14.3% (95% confidence interval 13.1% to 15.5%) among those who received prophylactic anticoagulation and 18.7% (15.1% to 22.9%) among those who did not. Compared with patients who did not receive prophylactic anticoagulation, those who did had a 27% decreased risk for 30 day mortality (hazard ratio 0.73, 95% confidence interval 0.66 to 0.81). Similar associations were found for inpatient mortality and initiation of therapeutic anticoagulation. Receipt of prophylactic anticoagulation was not associated with increased risk of bleeding that required transfusion (hazard ratio 0.87, 0.71 to 1.05). Quantitative bias analysis showed that results were robust to unmeasured confounding (e-value lower 95% confidence interval 1.77 for 30 day mortality). Results persisted in several sensitivity analyses. CONCLUSIONS: Early initiation of prophylactic anticoagulation compared with no anticoagulation among patients admitted to hospital with covid-19 was associated with a decreased risk of 30 day mortality and no increased risk of serious bleeding events. These findings provide strong real world evidence to support guidelines recommending the use of prophylactic anticoagulation as initial treatment for patients with covid-19 on hospital admission.


Assuntos
Anticoagulantes/uso terapêutico , Enoxaparina/uso terapêutico , Tromboembolia/prevenção & controle , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/efeitos adversos , Enoxaparina/efeitos adversos , Feminino , Hemorragia/induzido quimicamente , Humanos , Masculino , Pessoa de Meia-Idade , Admissão do Paciente , Tromboembolia/virologia , Fatores de Tempo , Estados Unidos/epidemiologia
4.
Int J Biol Macromol ; 171: 465-479, 2021 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-33428952

RESUMO

The ubiquitous nature of hemoglobins, their presence in multiple forms and low cellular expression in organisms suggests alternative physiological functions of hemoglobins in addition to oxygen transport and storage. Previous research has proposed enzymatic function of hemoglobins such as nitric oxide dioxygenase, nitrite reductase and hydroxylamine reductase. In all these enzymatic functions, active ferrous form of hemoglobin is converted to ferric form and reconversion of ferric to ferrous through reduction partners is under active investigation. The model alga C. reinhardtii contains multiple globins and is thus expected to have multiple putative methemoglobin reductases to augment the physiological functions of the novel hemoglobins. In this regard, three putative methemoglobin reductases and three algal hemoglobins were characterized. Our results signify that the identified putative methemoglobin reductases can reduce algal methemoglobins in a nonspecific manner under in vitro conditions. Enzyme kinetics of two putative methemoglobin reductases with methemoglobins as substrates and in silico analysis support interaction between the hemoglobins and the two reduction partners as also observed in vitro. Our investigation on algal methemoglobin reductases underpins the valuable chemistry of nitric oxide with the newly discovered hemoglobins to ensure their physiological relevance, with multiple hemoglobins probably necessitating the presence of multiple reductases.

5.
J Biomol Struct Dyn ; : 1-16, 2020 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-33356902

RESUMO

The ARL15 gene (ADP ribosylation factor like protein 15) encodes for an uncharacterized small GTP-binding protein. Its exact role in human physiology remains unknown, but a number of genetic association studies have recognised different variants in this gene to be statistically associated with numerous traits and complex diseases. We have previously reported a novel association of ARL15 with rheumatoid arthritis (RA) based on a genome-wide association study in a north Indian cohort. Subsequent investigations have provided leads for its involvement in RA pathophysiology, especially its potential as a novel therapeutic target. However, the absence of an experimentally determined tertiary structure for ARL15 significantly hinders the understanding of its biochemical and physiological functions, as well as development of potential lead molecules. We, therefore, aimed to derive a high quality, refined model of the three dimensional structure of human ARL15 protein using two different computational protein structure prediction methods - template-based threading and ab initio modelling. The best model each from among the five each derived from both the approaches was selected based on stringent quality assessment and refinement. Molecular dynamics simulations over long timescales revealed the ab initio model to be relatively more stable, and it marginally outperformed the template-based model in the quality assessment as well. A putative GTP-binding site was also predicted using homology for the ARL15 protein, where potential competitive inhibitors can be targeted. This high quality predicted model may provide insights to the biological role(s) of ARL15 and inform and guide further experimental, structural and biochemical characterization efforts. Communicated by Ramaswamy H. Sarma.

6.
Mol Immunol ; 2020 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-33221042

RESUMO

Macrophages play a crucial role in host innate immune defense against infection and tissue injury. Macrophages are highly plastic cells and their subtypes have been characterized as M1 (also termed classically activated) and M2 (alternatively activated). Although the M1/M2 paradigm has been well documented, less is known regarding the role of macrophage activation/polarization in inflammation-associated necrotic cell death. To address this gap in current knowledge, we prepared bone marrow-derived macrophages, induced them to M1 or M2 subtypes, and then investigated the expression of necroptosis signaling molecules and macrophage subtype-dependent responses to different necroptosis inducers. We found that necroptosis effector mixed lineage kinase domain-like protein (MLKL) and the key necroptosis regulator Z-DNA/RNA binding protein 1 were predominantly induced in M1 but not M2 macrophages. Interestingly, the protein but not mRNA levels of receptor-interacting protein kinase-3 (RIPK3) were also upregulated in M1 macrophages. We further found that macrophage necrotic cell death, the releases of lactate dehydrogenase and dead cell proteases as well as MLKL phosphorylation at Ser345 in response to various necroptosis inducers were greatly augmented in M1 but not M2 macrophages, and the accelerated effects were blocked by two structurally distinct specific RIPK3 inhibitors GSK872 or GSK843. Thus, our findings demonstrate that M1 but not M2 subtypes of macrophages are more susceptible to inflammation-related lytic cell death in an RIPK3 kinase activity-dependent manner.

7.
Life Sci ; 259: 118377, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32898526

RESUMO

The endothelium is the innermost vascular lining performing significant roles all over the human body while maintaining the blood pressure at physiological levels. Malfunction of endothelium is thus recognized as a biomarker linked with many vascular diseases including but not limited to atherosclerosis, hypertension and thrombosis. Alternatively, prevention of endothelial malfunctioning or regulating the functions of its associated physiological partners like endothelial nitric oxide synthase can prevent the associated vascular disorders which account for the highest death toll worldwide. While many anti-hypertensive drugs are available commercially, a comprehensive description of the key physiological roles of the endothelium and its regulation by endothelial nitric oxide synthase or vice versa is the need of the hour to understand its contribution in vascular homeostasis. This, in turn, will help in designing new therapeutics targeting endothelial nitric oxide synthase or its interacting partners present in the cellular pool. This review describes the central role of vascular endothelium in the regulation of endothelial nitric oxide synthase while outlining the emerging drug targets present in the vasculature with potential to treat vascular disorders including hypertension.


Assuntos
Pressão Sanguínea/fisiologia , Endotélio Vascular/fisiologia , Coração/fisiologia , Óxido Nítrico Sintase Tipo III/metabolismo , Animais , Endotélio Vascular/metabolismo , Humanos
8.
Expert Opin Investig Drugs ; 29(9): 1043-1057, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32658551

RESUMO

INTRODUCTION: Despite a large number of commercially available drugs, hypertension and related cardiovascular diseases remain a global problem. It is thus imperative that novel drugs and therapeutic strategies are regularly identified, and alternative targets explored. Dopamine ß hydroxylase (DBH), a key player in the catecholamine biosynthetic pathway, may provide a therapeutic opportunity and should be extensively explored as a target for potent anti-hypertensives. Inhibitors of DBH have been successful in combating hypertension, as evidenced by the outcome of clinical trials for etamicastat and zamicastat. AREAS COVERED: We shed light on the strategies employed to identify inhibitors of the enzyme and outline the advantages that the target might offer. Structural and functional details of the enzyme are described along with specific methodologies for drug discovery that were never utilized for the therapeutic target. EXPERT OPINION: Effective inhibitors of the enzyme may be identified with computer-aided structure-based design. Adoption of new methodologies and the assessment of newly designed inhibitors in DBH-specific animal models will provide new, safe, and cost-effective therapeutic opportunities.

9.
Int J Biol Macromol ; 162: 1054-1063, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32603730

RESUMO

One popular and relevant proposed function for cyanobacterial hemoglobin (Synechocystis Hb) is anaerobic nitrite reductase in vivo. During such reduction reactions, the hexacoordinated heme iron atom of SynHb is oxidized from the ferrous (Fe+2) to ferric (Fe+3) state and prevent damage by limiting the concentration of toxic metabolites such as nitrite. In order to perform these functions in vivo, there must be a mechanism that converts inactive Fe+3-SynHb back to the active Fe+2-SynHb to accomplish the nitrite reductase function. Here, we report a cognate reductase protein for Synechocystis hemoglobin which can reduce the Fe+3-SynHb to Fe+2-SynHb, thus lending a support to the proposed nitrite reductase function. This reductase is also able to reduce pentacoordinate Hbs such as myoglobin but with lower affinity compared to hexacoordinate SynHb. Insilico model of reductase protein-cyanobacterial hemoglobin complex revealed that the heme active site of Hb faces the catalytic center of the reductase protein and several amino acids in the interface interacts non-covalently thus favoring their interaction. Overall, our in vitro study provides the basic foundation for the understanding of the specific molecular mechanism of action and interaction of the SynHb reductase protein, which need to be investigated in further detail.

10.
Protein Pept Lett ; 2020 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-32533815

RESUMO

AIMS: The aim of our study is to understand the biophysical traits that govern the stability and folding of Synechocystis hemoglobin, a unique cyanobacterial globin that displays unusual traits not observed in any of the other globins discovered so far. BACKGROUND: For the past few decades, classical hemoglobins such as vertebrate hemoglobin and myoglobin have been extensively studied to unravel the stability and folding mechanisms of hemoglobins. However, the expanding wealth of hemoglobins identified in all life forms with novel properties, like heme coordination chemistry and globin fold, have added complexity and challenges to the understanding of hemoglobin stability, which has not been adequately addressed. Here, we explored the unique truncated and hexacoordinate hemoglobin from the freshwater cyanobacterium Synechocystis sp. PCC 6803 known as "Synechocystis hemoglobin (SynHb)". The "three histidines" linkages to heme are novel to this cyanobacterial hemoglobin. OBJECTIVE: Mutational studies were employed to decipher the residues within the heme pocket that dictate the stability and folding of SynHb. METHODS: Site-directed mutants of SynHb were generated and analyzed using a repertoire of spectroscopic and calorimetric tools. RESULT: The results revealed that the heme was stably associated to the protein under all denaturing conditions with His117 playing the anchoring role. The studies also highlighted the possibility of existence of a "molten globule" like intermediate at acidic pH in this exceptionally thermostable globin. His117 and other key residues in the heme pocket play an indispensable role in imparting significant polypeptide stability. CONCLUSION: Synechocystis hemoglobin presents an important model system for investigations of protein folding and stability in general. The heme pocket residues influenced the folding and stability of SynHb in a very subtle and specific manner and may have been optimized to make this Hb the most stable known as of date. Other: The knowledge gained hereby about the influence of heme pocket amino acid side chains on stability and expression is currently being utilized to improve the stability of recombinant human Hbs for efficient use as oxygen delivery vehicles.

11.
Protein Pept Lett ; 27(10): 1046-1057, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32242773

RESUMO

BACKGROUND: ß-Amylase (EC 3.2.1.2) is a maltogenic enzyme, which releases ß-maltose from the non-reducing end of the substrates. The enzyme plays important roles for the production of vaccine, maltiol and maltose rich syrups. Apart from these applications the enzyme protects cells from abiotic as well as oxidative damage. The enzyme is ßwell characterized in ßplants and microbes and crystal structures of ß-amylases ßhave been ßobtained from sweet potato, soybean and Bacillus cereus. OBJECTIVE: Find out correlation between structural and functional stability induced by change in pH, temperature and chaotropes. METHODS: Activity, intrinsic fluorescence, extrinsic fluorescence, near- and far- ultraviolet circular dichroism spectroscopic measurements were performed. RESULTS: Peaks about 208 nm and 222 nm obtained by near-ultraviolet circular dichroism correspond to α-helix whereas peak at 215 nm shows presence of ß-sheet. At pH 2.0, absence of tertiary structures, exposed of hydrophobic regions and presence of substantial secondary structures, revealed the existence of molten globule like state. Temperature induced denaturation studies showed that the enzyme was stable up to 75 ºC and the process was found to be irreversible in nature. Chaotropes dependent equilibrium unfolding studies revealed that at low concentration of chaotropes, ellipticity and intrinsic fluorescence ßintensity were ßdecreased ßwhereas ßenzymatic activity remained unchanged, which revealed fenugreek ß-amylase is multi-domains enzyme and catalytic ßdomain ßis more ßstable compare to non-catalytic domain. Moreover, the transition was sigmoidal and non-coincidental. CONCLUSION: Results indicate the probable existence of intermediate states that might perform significant role in physiological process and biotechnological applications.

12.
Psychosom Med ; 82(5): 461-470, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32282648

RESUMO

OBJECTIVE: We sought to determine the associations of total, cognitive/affective, and somatic depressive symptoms and antidepressant use with biomarkers of processes implicated in cardiovascular disease in HIV (HIV-CVD). METHODS: We examined data from 1546 HIV-positive and 843 HIV-negative veterans. Depressive symptoms were assessed using the Patient Health Questionnaire-9, and past-year antidepressant use was determined from Veterans Affair pharmacy records. Monocyte (soluble CD14 [sCD14]), inflammatory (interleukin-6 [IL-6]), and coagulation (D-dimer) marker levels were determined from previously banked blood specimens. Linear regression models with multiple imputation were run to estimate the associations between depression-related factors and CVD-relevant biomarkers. RESULTS: Among HIV-positive participants, greater somatic depressive symptoms were associated with higher sCD14 (exp[b] = 1.02, 95% confidence interval [CI] = 1.00-1.03) and D-dimer (exp[b] = 1.06, 95% CI = 1.00-1.11) after adjustment for demographics and potential confounders. Further adjustment for antidepressant use and HIV factors slightly attenuated these relationships. Associations were also detected for antidepressant use, as selective serotonin reuptake inhibitor use was related to lower sCD14 (exp[b] = 0.95, 95% CI = 0.91-1.00) and IL-6 (exp[b] = 0.86, 95% CI = 0.76-0.96), and tricyclic antidepressant use was related to higher sCD14 (exp[b] = 1.07, 95% CI = 1.03-1.12) and IL-6 (exp[b] = 1.14, 95% CI = 1.02-1.28). Among HIV-negative participants, total, cognitive/affective, and somatic depressive symptoms were associated with higher IL-6, and tricyclic antidepressant use was related to higher sCD14. CONCLUSIONS: Our novel findings suggest that a) monocyte activation and altered coagulation may represent two pathways through which depression increases HIV-CVD risk and that b) tricyclic antidepressants may elevate and selective serotonin reuptake inhibitors may attenuate HIV-CVD risk by influencing monocyte and inflammatory activation.

13.
Dalton Trans ; 49(16): 5015-5019, 2020 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-32096810

RESUMO

A radical path for the conversion of o-substituted arylamines to o-phenylenediimine derivatives is reported. In the presence of [RuII(PPh3)3Cl2] (RuP), 2-(phenylthio)aniline (LSNH2) acts as an o-amination agent. Reaction of LSNH2 with RuP in toluene promotes (4e + 4H+) oxidative dimerization affording an o-phenylenediimine complex of ruthenium(ii). Similarly, intermolecular coupling between LSNH2 and other arylamines has been achieved.

14.
JAMA ; 323(7): 627-635, 2020 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-32068817

RESUMO

Importance: Polygenic risk scores comprising millions of single-nucleotide polymorphisms (SNPs) could be useful for population-wide coronary heart disease (CHD) screening. Objective: To determine whether a polygenic risk score improves prediction of CHD compared with a guideline-recommended clinical risk equation. Design, Setting, and Participants: A retrospective cohort study of the predictive accuracy of a previously validated polygenic risk score was assessed among 4847 adults of white European ancestry, aged 45 through 79 years, participating in the Atherosclerosis Risk in Communities (ARIC) study and 2390 participating in the Multi-Ethnic Study of Atherosclerosis (MESA) from 1996 through December 31, 2015, the final day of follow-up. The performance of the polygenic risk score was compared with that of the 2013 American College of Cardiology and American Heart Association pooled cohort equations. Exposures: Genetic risk was computed for each participant by summing the product of the weights and allele dosage across 6 630 149 SNPs. Weights were based on an international genome-wide association study. Main Outcomes and Measures: Prediction of 10-year first CHD events (including myocardial infarctions, fatal coronary events, silent infarctions, revascularization procedures, or resuscitated cardiac arrest) assessed using measures of model discrimination, calibration, and net reclassification improvement (NRI). Results: The study population included 4847 adults from the ARIC study (mean [SD] age, 62.9 [5.6] years; 56.4% women) and 2390 adults from the MESA cohort (mean [SD] age, 61.8 [9.6] years; 52.2% women). Incident CHD events occurred in 696 participants (14.4%) and 227 participants (9.5%), respectively, over median follow-up of 15.5 years (interquartile range [IQR], 6.3 years) and 14.2 (IQR, 2.5 years) years. The polygenic risk score was significantly associated with 10-year CHD incidence in ARIC with hazard ratios per SD increment of 1.24 (95% CI, 1.15 to 1.34) and in MESA, 1.38 (95% CI, 1.21 to 1.58). Addition of the polygenic risk score to the pooled cohort equations did not significantly increase the C statistic in either cohort (ARIC, change in C statistic, -0.001; 95% CI, -0.009 to 0.006; MESA, 0.021; 95% CI, -0.0004 to 0.043). At the 10-year risk threshold of 7.5%, the addition of the polygenic risk score to the pooled cohort equations did not provide significant improvement in reclassification in either ARIC (NRI, 0.018, 95% CI, -0.012 to 0.036) or MESA (NRI, 0.001, 95% CI, -0.038 to 0.076). The polygenic risk score did not significantly improve calibration in either cohort. Conclusions and Relevance: In this analysis of 2 cohorts of US adults, the polygenic risk score was associated with incident coronary heart disease events but did not significantly improve discrimination, calibration, or risk reclassification compared with conventional predictors. These findings suggest that a polygenic risk score may not enhance risk prediction in a general, white middle-aged population.


Assuntos
Doença das Coronárias/genética , Predisposição Genética para Doença , Herança Multifatorial , Medição de Risco/métodos , Idoso , Estudos de Coortes , Doença das Coronárias/epidemiologia , Feminino , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/epidemiologia , Razão de Chances , Fenótipo , Polimorfismo de Nucleotídeo Único , Valor Preditivo dos Testes , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Risco
15.
JNCI Cancer Spectr ; 4(1): pkz086, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32025627

RESUMO

Background: Although uniform colonoscopy screening reduces colorectal cancer (CRC) mortality, risk-based screening may be more efficient. We investigated whether CRC screening based on polygenic risk is a cost-effective alternative to current uniform screening, and if not, under what conditions it would be. Methods: The MISCAN-Colon model was used to simulate a hypothetical cohort of US 40-year-olds. Uniform screening was modeled as colonoscopy screening at ages 50, 60, and 70 years. For risk-stratified screening, individuals underwent polygenic testing with current and potential future discriminatory performance (area under the receiver-operating curve [AUC] of 0.60 and 0.65-0.80, respectively). Polygenic testing results were used to create risk groups, for which colonoscopy screening was optimized by varying the start age (40-60 years), end age (70-85 years), and interval (1-20 years). Results: With current discriminatory performance, optimal screening ranged from once-only colonoscopy at age 60 years for the lowest-risk group to six colonoscopies at ages 40-80 years for the highest-risk group. While maintaining the same health benefits, risk-stratified screening increased costs by $59 per person. Risk-stratified screening could become cost-effective if the AUC value would increase beyond 0.65, the price per polygenic test would drop to less than $141, or risk-stratified screening would lead to a 5% increase in screening participation. Conclusions: Currently, CRC screening based on polygenic risk is unlikely to be cost-effective compared with uniform screening. This is expected to change with a greater than 0.05 increase in AUC value, a greater than 30% reduction in polygenic testing costs, or a greater than 5% increase in adherence with screening.

16.
Chemistry ; 25(65): 14901-14911, 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31411776

RESUMO

An N-pyridyl-o-aminophenol derivative that stabilises mixed-valence states of ruthenium ions is disclosed. A diruthenium complex, [(LIQ 0 )Ru2 Cl5 ]⋅MeOH (1⋅MeOH) is successfully isolated, in which LIQ 0 is the o-iminobenzoquinone form of 2-[(3-nitropyridin-2-yl)amino]phenol (LAP H2 ). In 1, LIQ 0 oriented towards one ruthenium centre is a non-innocent NO-donor redox ligand, whereas another oriented towards another ruthenium centre is an innocent pyridine-donor redox ligand. Complex 1 is a diruthenium(II,III) mixed-valence complex, [RuII (LIQ 0 )(µ-Cl)2 RuIII ], with a minor contribution from the diruthenium(III,III) state. [RuIII (LISQ .- )(µ-Cl)2 RuIII ] contains LISQ .- , which is the o-iminobenzosemiquinonate anion radical form of the ligand. Complexes 1- and 1+ are diruthenium(II,II), [RuII (LIQ 0 )(µ-Cl)2 RuII ], and diruthenium(III,III), [RuIII (LIQ 0 )(µ-Cl)2 RuIII ], complexes, respectively, of LIQ 0 . Complex 12- is a diruthenium(II,II) complex of the o-iminobenzosemiquinonate anion radical (LISQ .- ), [RuII (LISQ .- )(µ-Cl)2 RuII ], with a minor contribution from the diruthenium(III,II) form, [RuIII (LAP 2- )(µ-Cl)2 RuII ]. Complex 12+ is a diruthenium(III,IV) mixed-valence complex of LIQ 0 , [RuIII (LIQ 0 )(µ-Cl)2 RuIV ]. Complexes 1 and 12+ exhibit inter-valence charge-transfer transitions at λ=1300 and 1370 nm, respectively.

17.
JAMA ; 322(7): 642-650, 2019 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-31429895

RESUMO

Importance: The time course of cardiovascular disease (CVD) risk after smoking cessation is unclear. Risk calculators consider former smokers to be at risk for only 5 years. Objective: To evaluate the association between years since quitting smoking and incident CVD. Design, Setting, and Participants: Retrospective analysis of prospectively collected data from Framingham Heart Study participants without baseline CVD (original cohort: attending their fourth examination in 1954-1958; offspring cohort: attending their first examination in 1971-1975) who were followed up through December 2015. Exposures: Time-updated self-reported smoking status, years since quitting, and cumulative pack-years. Main Outcomes and Measures: Incident CVD (myocardial infarction, stroke, heart failure, or cardiovascular death). Primary analyses included both cohorts (pooled) and were restricted to heavy ever smokers (≥20 pack-years). Results: The study population included 8770 individuals (original cohort: n = 3805; offspring cohort: n = 4965) with a mean age of 42.2 (SD, 11.8) years and 45% male. There were 5308 ever smokers with a median 17.2 (interquartile range, 7-30) baseline pack-years, including 2371 heavy ever smokers (406 [17%] former and 1965 [83%] current). Over 26.4 median follow-up years, 2435 first CVD events occurred (original cohort: n = 1612 [n = 665 among heavy smokers]; offspring cohort: n = 823 [n = 430 among heavy smokers]). In the pooled cohort, compared with current smoking, quitting within 5 years was associated with significantly lower rates of incident CVD (incidence rates per 1000 person-years: current smoking, 11.56 [95% CI, 10.30-12.98]; quitting within 5 years, 6.94 [95% CI, 5.61-8.59]; difference, -4.51 [95% CI, -5.90 to -2.77]) and lower risk of incident CVD (hazard ratio, 0.61; 95% CI, 0.49-0.76). Compared with never smoking, quitting smoking ceased to be significantly associated with greater CVD risk between 10 and 15 years after cessation in the pooled cohort (incidence rates per 1000 person-years: never smoking, 5.09 [95% CI, 4.52-5.74]; quitting within 10 to <15 years, 6.31 [95% CI, 4.93-8.09]; difference, 1.27 [95% CI, -0.10 to 3.05]; hazard ratio, 1.25 [95% CI, 0.98-1.60]). Conclusions and Relevance: Among heavy smokers, smoking cessation was associated with significantly lower risk of CVD within 5 years relative to current smokers. However, relative to never smokers, former smokers' CVD risk remained significantly elevated beyond 5 years after smoking cessation.


Assuntos
Doenças Cardiovasculares/epidemiologia , Fumantes , Abandono do Hábito de Fumar , Adulto , Doenças Cardiovasculares/prevenção & controle , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Risco , Fatores de Risco
18.
Open Forum Infect Dis ; 6(6): ofz188, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31211153

RESUMO

Background: The prevalence and risk of concurrent unhealthy drinking, cigarette use, and depression on mortality among persons living with HIV (PLWH) is unclear. This study applied a syndemic framework to assess whether these co-occurring conditions increase mortality and whether such risk is differential by HIV status. Methods: We evaluated 6721 participants (49.8% PLWH) without baseline cancer from the Veterans Aging Cohort Study, a prospective, observational cohort of PLWH and matched uninfected veterans enrolled in 2002 and followed through 2015. Multivariable Cox proportional hazards regressions estimated risk of a syndemic score (number of conditions: that is, unhealthy drinking, cigarette use, and depressive symptoms) on all-cause mortality by HIV status, adjusting for demographic, health status, and HIV-related factors. Results: Fewer than 10% of participants had no conditions; 25.6% had 1, 51.0% had 2, and 15.0% had all 3. There were 1747 deaths (61.9% PLWH) during the median follow-up (11.4 years). Overall, age-adjusted mortality rates/1000 person-years increased with a greater number of conditions: (0: 12.0; 1: 21.2; 2: 30.4; 3: 36.3). For 3 conditions, the adjusted hazard ratio of mortality was 36% higher among PLWH compared with uninfected participants with 3 conditions (95% confidence interval, 1.07-1.72; P = .013), after adjusting for health status and HIV disease progression. Among PLWH and uninfected participants, mortality risk persisted after adjustment for time-updated health status. Conclusions: Syndemic unhealthy drinking, cigarette use, and depression are common and are associated with higher mortality risk among PLWH, underscoring the need to screen for and treat these conditions.

19.
Cancer Epidemiol Biomarkers Prev ; 28(8): 1345-1352, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31160346

RESUMO

BACKGROUND: Precision interventions using biological data may enhance smoking treatment, yet are understudied among smokers who are disproportionately burdened by smoking-related disease. METHODS: We surveyed smokers in the NCI-sponsored Southern Community Cohort Study, consisting primarily of African-American, low-income adults. Seven items assessed attitudes toward aspects of precision smoking treatment, from undergoing tests to acting on results. Items were dichotomized as favorable (5 = strongly agree/4 = agree) versus less favorable (1 = strongly disagree/2 = disagree/3 = neutral); a summary score reflecting generalized attitudes was also computed. Multivariable logistic regression tested independent associations of motivation (precontemplation, contemplation, and preparation) and confidence in quitting (low, medium, and high) with generalized attitudes, controlling for sociodemographic factors and nicotine dependence. RESULTS: More than 70% of respondents endorsed favorable generalized attitudes toward precision medicine, with individual item favorability ranging from 64% to 83%. Smokers holding favorable generalized attitudes reported higher income and education (P < 0.05). Predicted probabilities of favorable generalized attitudes ranged from 63% to 75% across motivation levels [contemplation vs. precontemplation: adjusted odds ratio (AOR) = 2.10, 95% confidence interval (CI), 1.36-3.25, P = 0.001; preparation vs. precontemplation: AOR = 1.83, 95% CI, 1.20-2.78, P = 0.005; contemplation vs. preparation: AOR = 1.15, 95% CI, 0.75-1.77, P = 0.52] and from 59% to 78% across confidence (medium vs. low: AOR = 1.91, 95% CI, 1.19-3.07, P = 0.007; high vs. low: AOR = 2.62, 95% CI, 1.68-4.10, P < 0.001; medium vs. high: AOR = 0.73, 95% CI, 0.48-1.11, P = 0.14). CONCLUSIONS: Among disproportionately burdened community smokers, most hold favorable attitudes toward precision smoking treatment. Individuals with lower motivation and confidence to quit may benefit from additional intervention to engage with precision smoking treatment. IMPACT: Predominantly favorable attitudes toward precision smoking treatment suggest promise for future research testing their effectiveness and implementation.


Assuntos
Atitude Frente a Saúde , Abandono do Hábito de Fumar/psicologia , Fumar Tabaco/psicologia , Tabagismo/psicologia , Tabagismo/terapia , Idoso , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Estudos de Coortes , Feminino , Humanos , Neoplasias Pulmonares/etiologia , Neoplasias Pulmonares/psicologia , Masculino , Pessoa de Meia-Idade , Motivação , Medicina de Precisão/métodos , Medicina de Precisão/psicologia , Estudos Prospectivos , Fatores de Risco , Abandono do Hábito de Fumar/métodos , Fatores Socioeconômicos , Inquéritos e Questionários , Fumar Tabaco/efeitos adversos , Tabagismo/etiologia , Estados Unidos
20.
J Acquir Immune Defic Syndr ; 81(1): 110-117, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30768487

RESUMO

BACKGROUND: Insomnia is associated with increased cardiovascular disease (CVD) risk in the general population and is highly prevalent in people with HIV. The CVD risk conferred by insomnia in the HIV population is unknown. METHODS: Using the Veterans Aging Cohort Study Survey Cohort, insomnia symptoms were measured and dummy coded with the item, "Difficulty falling or staying asleep?" (5-point scale from no difficulty to bothers a lot). Incident CVD event ICD-9 codes (acute myocardial infarction, stroke, or coronary artery revascularization) were identified with the Department of Veterans Affairs (VA) and Medicare administrative data and VA fee-for-service data. Those with baseline CVD were excluded. RESULTS: HIV-infected (N = 3108) veterans had a median follow-up time of 10.8 years, during which 267 CVD events occurred. Compared to HIV-infected veterans with no difficulty falling or staying asleep, HIV-infected veterans bothered a lot by insomnia symptoms had an increased risk of incident CVD after adjusting for demographics [hazard ratio (HR) = 1.64, 95% confidence interval (CI): 1.16 to 2.31, P = 0.005], CVD risk factors (HR = 1.62, 95% CI: 1.14 to 2.30, P = 0.007), additional potential confounders (hepatitis C infection, renal disease, anemia, alcohol use, and cocaine use; HR = 1.70, 95% CI: 1.19 to 2.43, P = 0.003), and HIV-specific factors (HIV-1 RNA, CD4 T-cell count, and antiretroviral therapy; HR = 1.66, 95% CI: 1.16 to 2.37, P = 0.005). Additional adjustment for nonbenzodiazepine sleep medication (HR = 1.62, 95% CI: 1.13 to 2.32, P = 0.009) did not attenuate the association; however, it fell short of significance at P < 0.01 after adjustment for depressive symptoms (HR = 1.51, 95% CI: 0.98 to 2.32, P = 0.060) or antidepressant medication (HR = 1.51, 95% CI: 1.04 to 2.19, P = 0.031). CONCLUSIONS: Highly bothersome insomnia symptoms were significantly associated with incident CVD in HIV-infected veterans, suggesting that insomnia may be a novel, modifiable risk factor for CVD in HIV.


Assuntos
Doenças Cardiovasculares/etiologia , Infecções por HIV/complicações , Distúrbios do Início e da Manutenção do Sono/complicações , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Estados Unidos , Veteranos/estatística & dados numéricos
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