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1.
Macromolecules ; 56(14): 5619-5627, 2023 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-37521248

RESUMEN

We investigate the thermodynamics of a highly interacting blend of poly(cyclohexyl methacrylate)/deuterated poly(styrene) (PCHMA/dPS) with small-angle neutron scattering (SANS). This system is experimentally challenging due to the proximity of the blend phase boundary (>200 °C) and degradation temperatures. To achieve the large wavenumber q-range and flux required for kinetic experiments, we employ a SANS diffractometer in time-of-flight (TOF) mode at a reactor source and ancillary microscopy, calorimetry, and thermal gravimetric analysis. Isothermal SANS data are well described by random-phase approximation (RPA), yielding the second derivative of the free energy of mixing (G″), the effective interaction (χ̅) parameter, and extrapolated spinodal temperatures. Instead of the Cahn-Hilliard-Cook (CHC) framework, temperature (T)-jump experiments within the one-phase region are found to be well described by the RPA at all temperatures away from the glass transition temperature, providing effectively near-equilibrium results. We employ CHC theory to estimate the blend mobility and G″(T) conditions where such an approximation holds. TOF-SANS is then used to precisely resolve G″(T) and χ̅(T) during T-jumps in intervals of a few seconds and overall timescales of a few minutes. PCHMA/dPS emerges as a highly interacting partially miscible blend, with a steep dependence of G″(T) [mol/cm3] = -0.00228 + 1.1821/T [K], which we benchmark against previously reported highly interacting lower critical solution temperature (LCST) polymer blends.

2.
MMWR Morb Mortal Wkly Rep ; 71(6): 206-211, 2022 02 11.
Artículo en Inglés | MEDLINE | ID: mdl-35143464

RESUMEN

Genomic surveillance is a critical tool for tracking emerging variants of SARS-CoV-2 (the virus that causes COVID-19), which can exhibit characteristics that potentially affect public health and clinical interventions, including increased transmissibility, illness severity, and capacity for immune escape. During June 2021-January 2022, CDC expanded genomic surveillance data sources to incorporate sequence data from public repositories to produce weighted estimates of variant proportions at the jurisdiction level and refined analytic methods to enhance the timeliness and accuracy of national and regional variant proportion estimates. These changes also allowed for more comprehensive variant proportion estimation at the jurisdictional level (i.e., U.S. state, district, territory, and freely associated state). The data in this report are a summary of findings of recent proportions of circulating variants that are updated weekly on CDC's COVID Data Tracker website to enable timely public health action.† The SARS-CoV-2 Delta (B.1.617.2 and AY sublineages) variant rose from 1% to >50% of viral lineages circulating nationally during 8 weeks, from May 1-June 26, 2021. Delta-associated infections remained predominant until being rapidly overtaken by infections associated with the Omicron (B.1.1.529 and BA sublineages) variant in December 2021, when Omicron increased from 1% to >50% of circulating viral lineages during a 2-week period. As of the week ending January 22, 2022, Omicron was estimated to account for 99.2% (95% CI = 99.0%-99.5%) of SARS-CoV-2 infections nationwide, and Delta for 0.7% (95% CI = 0.5%-1.0%). The dynamic landscape of SARS-CoV-2 variants in 2021, including Delta- and Omicron-driven resurgences of SARS-CoV-2 transmission across the United States, underscores the importance of robust genomic surveillance efforts to inform public health planning and practice.


Asunto(s)
COVID-19/epidemiología , COVID-19/virología , SARS-CoV-2/genética , Centers for Disease Control and Prevention, U.S. , Genómica , Humanos , Prevalencia , Vigilancia en Salud Pública/métodos , Estados Unidos/epidemiología
3.
MMWR Morb Mortal Wkly Rep ; 70(23): 846-850, 2021 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-34111060

RESUMEN

SARS-CoV-2, the virus that causes COVID-19, is constantly mutating, leading to new variants (1). Variants have the potential to affect transmission, disease severity, diagnostics, therapeutics, and natural and vaccine-induced immunity. In November 2020, CDC established national surveillance for SARS-CoV-2 variants using genomic sequencing. As of May 6, 2021, sequences from 177,044 SARS-CoV-2-positive specimens collected during December 20, 2020-May 6, 2021, from 55 U.S. jurisdictions had been generated by or reported to CDC. These included 3,275 sequences for the 2-week period ending January 2, 2021, compared with 25,000 sequences for the 2-week period ending April 24, 2021 (0.1% and 3.1% of reported positive SARS-CoV-2 tests, respectively). Because sequences might be generated by multiple laboratories and sequence availability varies both geographically and over time, CDC developed statistical weighting and variance estimation methods to generate population-based estimates of the proportions of identified variants among SARS-CoV-2 infections circulating nationwide and in each of the 10 U.S. Department of Health and Human Services (HHS) geographic regions.* During the 2-week period ending April 24, 2021, the B.1.1.7 and P.1 variants represented an estimated 66.0% and 5.0% of U.S. SARS-CoV-2 infections, respectively, demonstrating the rise to predominance of the B.1.1.7 variant of concern† (VOC) and emergence of the P.1 VOC in the United States. Using SARS-CoV-2 genomic surveillance methods to analyze surveillance data produces timely population-based estimates of the proportions of variants circulating nationally and regionally. Surveillance findings demonstrate the potential for new variants to emerge and become predominant, and the importance of robust genomic surveillance. Along with efforts to characterize the clinical and public health impact of SARS-CoV-2 variants, surveillance can help guide interventions to control the COVID-19 pandemic in the United States.


Asunto(s)
COVID-19/virología , SARS-CoV-2/genética , COVID-19/epidemiología , Monitoreo Epidemiológico , Humanos , SARS-CoV-2/aislamiento & purificación , Estados Unidos/epidemiología
7.
Am J Clin Nutr ; 110(1): 158-168, 2019 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-31127807

RESUMEN

BACKGROUND: Serum vitamin B-12 is measured to evaluate vitamin B-12 status. Serum methylmalonic acid (MMA) is a specific functional indicator of vitamin B-12 status; however, concentrations increase with impaired renal function. OBJECTIVE: The aim of this study was to describe the distribution of serum vitamin B-12 and MMA in US adults, and estimate age-specific reference intervals for serum MMA in a healthy subpopulation with replete vitamin B-12 status and normal renal function. METHODS: We examined cross-sectional data for serum vitamin B-12 and MMA in adults participating in the NHANES from 2011 to 2014. Vitamin B-12 was measured by electrochemiluminescence assay and MMA by isotope-dilution liquid chromatography-tandem mass spectrometry. RESULTS: In both bivariate and multivariate analyses, age, race/Hispanic origin, and vitamin B-12 supplement use were generally significantly associated with serum vitamin B-12 and MMA concentrations. Serum MMA concentrations increased with age, particularly in persons aged ≥70 y. Non-Hispanic white persons had lower vitamin B-12 and higher MMA concentrations than non-Hispanic black persons. Shorter fasting times and impaired renal function were significantly associated with higher serum MMA concentrations, but not with serum vitamin B-12 concentrations after controlling for covariates. The central 95% reference intervals for serum vitamin B-12 and MMA concentrations were widest for persons aged ≥70 y compared with younger age groups. Compared with the overall population, the central 95% reference intervals for serum MMA concentrations were considerably narrower for a vitamin B-12-replete subpopulation with normal renal function, but still age-dependent. Serum vitamin B-12 showed little, whereas serum MMA showed notable, increases with impaired renal function. CONCLUSIONS: The higher serum MMA concentrations throughout the entire distribution in older persons (especially persons aged ≥70 y) who are vitamin B-12-replete and have normal renal function indicate the need for age-specific MMA reference intervals to better interpret vitamin B-12 status in epidemiologic research.


Asunto(s)
Factores de Edad , Ácido Metilmalónico/sangre , Deficiencia de Vitamina B 12/sangre , Vitamina B 12/sangre , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores , Etnicidad , Femenino , Humanos , Riñón/fisiopatología , Masculino , Persona de Mediana Edad , Encuestas Nutricionales , Valores de Referencia , Sensibilidad y Especificidad , Estados Unidos , Deficiencia de Vitamina B 12/fisiopatología , Adulto Joven
8.
Environ Health Perspect ; 126(6): 067011, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29961657

RESUMEN

BACKGROUND: The CDC recommends a targeted strategy for childhood blood lead screening based on participation in federal programs, such as Medicaid and the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). Yet, there is scarcity of data on blood lead levels (BLLs) among WIC participants. OBJECTIVE: Our objective was to investigate whether children participating in WIC and not enrolled in Medicaid, who have not been targeted in the historical Medicaid-focused screening strategy, have higher BLLs than children in neither of these programs. METHODS: The analysis included 3,180 children 1-5 y of age in the National Health and Nutrition Examination Surveys conducted in 2007-2014. Log-binomial regression, which allows direct estimation of prevalence ratios, was used to examine associations between WIC participation (in conjunction with Medicaid enrollment) and having BLLs ≥5 µg/dL with adjustment for age (1-2 vs. 3-5 y). RESULTS: The percentage of children participating in "WIC only," "Medicaid only," "both WIC and Medicaid," and "neither" were 18.9%, 10.8%, 25.4%, and 44.9%, respectively. "WIC only," "Medicaid only," and "both WIC and Medicaid" children were more likely to have BLLs ≥5 µg/dL than children who were not enrolled in either program, with adjusted prevalence ratios of 3.29 [95% confidence interval (CI): 1.19, 9.09], 4.56 (95% CI: 2.18, 9.55), and 2.58 (95% CI: 1.18, 5.63). CONCLUSIONS: Children participating in WIC but not Medicaid were more likely to have BLLs ≥5 µg/dL than children who were not enrolled in either program. These findings may inform public health recommendations and clinical practice guidelines. https://doi.org/10.1289/EHP2384


Asunto(s)
Asistencia Alimentaria/estadística & datos numéricos , Intoxicación por Plomo/epidemiología , Medicaid/estadística & datos numéricos , Preescolar , Femenino , Humanos , Lactante , Plomo/sangre , Intoxicación por Plomo/sangre , Intoxicación por Plomo/prevención & control , Masculino , Encuestas Nutricionales , Prevalencia , Estados Unidos
9.
Nutrients ; 10(7)2018 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-29986412

RESUMEN

We estimated iodine status (median urinary iodine concentration (mUIC (µg/L))) for the US population (6 years and over; n = 4613) and women of reproductive age (WRA) (15⁻44 years; n = 901). We estimated mean intake of key iodine sources by race and Hispanic origin. We present the first national estimates of mUIC for non-Hispanic Asian persons and examine the intake of soy products, a potential source of goitrogens. One-third of National Health and Nutrition Examination Survey (NHANES) participants in 2011⁻2014 provided casual urine samples; UIC was measured in these samples. We assessed dietary intake with one 24-h recall and created food groups using the USDA’s food/beverage coding scheme. For WRA, mUIC was 110 µg/L. For both non-Hispanic white (106 µg/L) and non-Hispanic Asian (81 µg/L) WRA mUIC was significantly lower than mUIC among Hispanic WRA (133 µg/L). Non-Hispanic black WRA had a mUIC of 124 µg/L. Dairy consumption was significantly higher among non-Hispanic white (162 g) compared to non-Hispanic black WRA (113 g). Soy consumption was also higher among non-Hispanic Asian WRA (18 g compared to non-Hispanic black WRA (1 g). Differences in the consumption pattern of key sources of iodine and goitrogens may put subgroups of individuals at risk of mild iodine deficiency. Continued monitoring of iodine status and variations in consumption patterns is needed.


Asunto(s)
Enfermedades Carenciales/prevención & control , Dieta , Yodo/administración & dosificación , Estado Nutricional , Salud Reproductiva , Cloruro de Sodio Dietético/administración & dosificación , Salud de la Mujer , Adolescente , Adulto , Factores de Edad , Biomarcadores/orina , Enfermedades Carenciales/diagnóstico , Enfermedades Carenciales/etnología , Dieta/efectos adversos , Femenino , Humanos , Yodo/deficiencia , Yodo/orina , Encuestas Nutricionales , Valor Nutritivo , Ingesta Diaria Recomendada , Salud Reproductiva/etnología , Factores Sexuales , Cloruro de Sodio Dietético/orina , Estados Unidos/epidemiología , Salud de la Mujer/etnología , Adulto Joven
10.
JAMA ; 319(23): 2410-2418, 2018 06 19.
Artículo en Inglés | MEDLINE | ID: mdl-29922826

RESUMEN

Importance: Differences in childhood obesity by demographics and urbanization have been reported. Objective: To present data on obesity and severe obesity among US youth by demographics and urbanization and to investigate trends by urbanization. Design, Setting, and Participants: Measured weight and height among youth aged 2 to 19 years in the 2001-2016 National Health and Nutrition Examination Surveys, which are serial, cross-sectional, nationally representative surveys of the civilian, noninstitutionalized population. Exposures: Sex, age, race and Hispanic origin, education of household head, and urbanization, as assessed by metropolitan statistical areas (MSAs; large: ≥ 1 million population). Main Outcomes and Measures: Prevalence of obesity (body mass index [BMI] ≥95th percentile of US Centers for Disease Control and Prevention [CDC] growth charts) and severe obesity (BMI ≥120% of 95th percentile) by subgroups in 2013-2016 and trends by urbanization between 2001-2004 and 2013-2016. Results: Complete data on weight, height, and urbanization were available for 6863 children and adolescents (mean age, 11 years; female, 49%). In 2013-2016, the prevalence among youth aged 2 to 19 years was 17.8% (95% CI, 16.1%-19.6%) for obesity and 5.8% (95% CI, 4.8%-6.9%) for severe obesity. Prevalence of obesity in large MSAs (17.1% [95% CI, 14.9%-19.5%]), medium or small MSAs (17.2% [95% CI, 14.5%-20.2%]) and non-MSAs (21.7% [95% CI, 16.1%-28.1%]) were not significantly different from each other (range of pairwise comparisons P = .09-.96). Severe obesity was significantly higher in non-MSAs (9.4% [95% CI, 5.7%-14.4%]) compared with large MSAs (5.1% [95% CI, 4.1%-6.2%]; P = .02). In adjusted analyses, obesity and severe obesity significantly increased with greater age and lower education of household head, and severe obesity increased with lower level of urbanization. Compared with non-Hispanic white youth, obesity and severe obesity prevalence were significantly higher among non-Hispanic black and Hispanic youth. Severe obesity, but not obesity, was significantly lower among non-Hispanic Asian youth than among non-Hispanic white youth. There were no significant linear or quadratic trends in obesity or severe obesity prevalence from 2001-2004 to 2013-2016 for any urbanization category (P range = .07-.83). Conclusions and Relevance: In 2013-2016, there were differences in the prevalence of obesity and severe obesity by age, race and Hispanic origin, and household education, and severe obesity was inversely associated with urbanization. Demographics were not related to the urbanization findings.


Asunto(s)
Obesidad Infantil/epidemiología , Adolescente , Distribución por Edad , Índice de Masa Corporal , Niño , Preescolar , Estudios Transversales , Escolaridad , Femenino , Hispánicos o Latinos/estadística & datos numéricos , Humanos , Masculino , Encuestas Nutricionales , Obesidad Mórbida/epidemiología , Obesidad Infantil/etnología , Población , Prevalencia , Factores de Riesgo , Distribución por Sexo , Estados Unidos/epidemiología , Adulto Joven
11.
JAMA ; 319(23): 2419-2429, 2018 06 19.
Artículo en Inglés | MEDLINE | ID: mdl-29922829

RESUMEN

Importance: Differences in obesity by sex, age group, race and Hispanic origin among US adults have been reported, but differences by urbanization level have been less studied. Objectives: To provide estimates of obesity by demographic characteristics and urbanization level and to examine trends in obesity prevalence by urbanization level. Design, Setting, and Participants: Serial cross-sectional analysis of measured height and weight among adults aged 20 years or older in the 2001-2016 National Health and Nutrition Examination Survey, a nationally representative survey of the civilian, noninstitutionalized US population. Exposures: Sex, age group, race and Hispanic origin, education level, smoking status, and urbanization level as assessed by metropolitan statistical areas (MSAs; large: ≥1 million population). Main Outcomes and Measures: Prevalence of obesity (body mass index [BMI] ≥30) and severe obesity (BMI ≥40) by subgroups in 2013-2016 and trends by urbanization level between 2001-2004 and 2013-2016. Results: Complete data on weight, height, and urbanization level were available for 10 792 adults (mean age, 48 years; 51% female [weighted]). During 2013-2016, 38.9% (95% CI, 37.0% to 40.7%) of US adults had obesity and 7.6% (95% CI, 6.8% to 8.6%) had severe obesity. Men living in medium or small MSAs had a higher age-adjusted prevalence of obesity compared with men living in large MSAs (42.4% vs 31.8%, respectively; adjusted difference, 9.8 percentage points [95% CI, 5.1 to 14.5 percentage points]); however, the age-adjusted prevalence among men living in non-MSAs was not significantly different compared with men living in large MSAs (38.9% vs 31.8%, respectively; adjusted difference, 4.8 percentage points [95% CI, -2.9 to 12.6 percentage points]). The age-adjusted prevalence of obesity was higher among women living in medium or small MSAs compared with women living in large MSAs (42.5% vs 38.1%, respectively; adjusted difference, 4.3 percentage points [95% CI, 0.2 to 8.5 percentage points]) and among women living in non-MSAs compared with women living in large MSAs (47.2% vs 38.1%, respectively; adjusted difference, 4.7 percentage points [95% CI, 0.2 to 9.3 percentage points]). Similar patterns were seen for severe obesity except that the difference between men living in large MSAs compared with non-MSAs was significant. The age-adjusted prevalence of obesity and severe obesity also varied significantly by age group, race and Hispanic origin, and education level, and these patterns of variation were often different by sex. Between 2001-2004 and 2013-2016, the age-adjusted prevalence of obesity and severe obesity significantly increased among all adults at all urbanization levels. Conclusions and Relevance: In this nationally representative survey of adults in the United States, the age-adjusted prevalence of obesity and severe obesity in 2013-2016 varied by level of urbanization, with significantly greater prevalence of obesity and severe obesity among adults living in nonmetropolitan statistical areas compared with adults living in large metropolitan statistical areas.


Asunto(s)
Obesidad/epidemiología , Adulto , Distribución por Edad , Anciano , Índice de Masa Corporal , Estudios Transversales , Escolaridad , Femenino , Hispánicos o Latinos/estadística & datos numéricos , Humanos , Masculino , Persona de Mediana Edad , Encuestas Nutricionales , Obesidad/etnología , Obesidad Mórbida/epidemiología , Población , Prevalencia , Factores de Riesgo , Distribución por Sexo , Estados Unidos/epidemiología
12.
Environ Res ; 155: 193-198, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28231546

RESUMEN

BACKGROUND: There have been increasing concerns over health effects of low level exposure to cadmium, especially those on bones and kidneys. OBJECTIVE: To explore how age-adjusted geometric means of blood cadmium in adults varied by race/Hispanic origin, sex, and smoking status among U.S. adults and the extent to which the difference in blood cadmium by race/Hispanic origin and sex may be explained by intensity of smoking, a known major source of cadmium exposure. METHODS: Our sample included 7,368 adults from National Health and Nutrition Examination Survey (NHANES) 2011-2014. With direct age adjustment, geometric means of blood cadmium and number of cigarettes smoked per day were estimated for subgroups defined by race/Hispanic origin, smoking status, and sex using interval regression, which allows mean estimation in the presence of left- and right-censoring. RESULTS: Among never and former smoking men and women, blood cadmium tended to be higher for non-Hispanic Asian adults than adults of other race/Hispanic origin. Among current smokers, who generally had higher blood cadmium than never and former smokers, non-Hispanic white, black, and Asian adults had similarly elevated blood cadmium compared to Hispanic adults. A separate analysis revealed that non-Hispanic white adults tended to have the highest smoking intensity regardless of sex, than adults of the other race/Hispanic origin groups. CONCLUSIONS: The observed pattern provided evidence for smoking as a major source of cadmium exposure, yet factors other than smoking also appeared to contribute to higher blood cadmium of non-Hispanic Asian adults.


Asunto(s)
Cadmio/sangre , Contaminantes Ambientales/sangre , Fumar/sangre , Adulto , Negro o Afroamericano , Pueblo Asiatico , Monitoreo del Ambiente , Femenino , Hispánicos o Latinos , Humanos , Masculino , Persona de Mediana Edad , Encuestas Nutricionales , Fumar/epidemiología , Estados Unidos , Población Blanca , Adulto Joven
13.
Am J Public Health ; 106(11): 2049-2056, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27631737

RESUMEN

OBJECTIVES: To compare blood lead levels (BLLs) among US children aged 1 to 5 years according to receipt of federal housing assistance. METHODS: In our analyses, we used 2005 to 2012 data for National Health and Nutrition Examination Survey (NHANES) respondents that were linked to 1999 to 2014 administrative records from the US Department of Housing and Urban Development (HUD). After we restricted the analysis to children with family income-to-poverty ratios below 200%, we compared geometric mean BLLs and the prevalence of BLLs of 3 micrograms per deciliter or higher among children who were living in assisted housing at the time of their NHANES blood draw (n = 151) with data for children who did not receive housing assistance (n = 1099). RESULTS: After adjustment, children living in assisted housing had a significantly lower geometric mean BLL (1.44 µg/dL; 95% confidence interval [CI] = 1.31, 1.57) than comparable children who did not receive housing assistance (1.79 µg/dL; 95% CI = 1.59, 2.01; P < .01). The prevalence ratio for BLLs of 3 micrograms per deciliter or higher was 0.51 (95% CI = 0.33, 0.81; P < .01). CONCLUSIONS: Children aged 1 to 5 years during 2005 to 2012 who were living in HUD-assisted housing had lower BLLs than expected given their demographic, socioeconomic, and family characteristics.


Asunto(s)
Plomo/sangre , Pobreza/estadística & datos numéricos , Vivienda Popular/estadística & datos numéricos , Preescolar , Femenino , Humanos , Lactante , Masculino , Prevalencia , Puntaje de Propensión , Factores de Riesgo , Factores Socioeconómicos , Estados Unidos
14.
Medicine (Baltimore) ; 95(1): e2223, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26735529

RESUMEN

Analyses of the Third National Health and Nutrition Examination Survey (NHANES III) in 1988 to 1994 found an association of increasing blood lead levels < 10 µg/dL with a higher risk of cardiovascular disease (CVD) mortality. The potential need to correct blood lead for hematocrit/hemoglobin and adjust for biomarkers for other metals, for example, cadmium and iron, had not been addressed in the previous NHANES III-based studies on blood lead-CVD mortality association. We analyzed 1999 to 2010 NHANES data for 18,602 participants who had a blood lead measurement, were ≥ 40 years of age at the baseline examination and were followed for mortality through 2011. We calculated the relative risk for CVD mortality as a function of hemoglobin- or hematocrit-corrected log-transformed blood lead through Cox proportional hazard regression analysis with adjustment for serum iron, blood cadmium, serum C-reactive protein, serum calcium, smoking, alcohol intake, race/Hispanic origin, and sex. The adjusted relative risk for CVD mortality was 1.44 (95% confidence interval = 1.05, 1.98) per 10-fold increase in hematocrit-corrected blood lead with little evidence of nonlinearity. Similar results were obtained with hemoglobin-corrected blood lead. Not correcting blood lead for hematocrit/hemoglobin resulted in underestimation of the lead-CVD mortality association while not adjusting for iron status and blood cadmium resulted in overestimation of the lead-CVD mortality association. In a nationally representative sample of U.S. adults, log-transformed blood lead was linearly associated with increased CVD mortality. Correcting blood lead for hematocrit/hemoglobin and adjustments for some biomarkers affected the association.


Asunto(s)
Enfermedades Cardiovasculares/mortalidad , Plomo/sangre , Adulto , Anciano , Consumo de Bebidas Alcohólicas/epidemiología , Biomarcadores , Proteína C-Reactiva/análisis , Cadmio/sangre , Enfermedades Cardiovasculares/etnología , Causas de Muerte , Femenino , Hematócrito , Hemoglobinas , Humanos , Hierro/sangre , Masculino , Persona de Mediana Edad , Encuestas Nutricionales , Modelos de Riesgos Proporcionales , Características de la Residencia , Factores de Riesgo , Factores Sexuales , Fumar/epidemiología , Estados Unidos
15.
J Biochem ; 158(6): 477-84, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26115687

RESUMEN

In this study, the physicochemical and enzymatic properties of recombinant human ubiquitin (Ub)-specific protease (USP) 47, a novel member of the C19 family of de-ubiquitinating enzymes (DUB), were characterized for the first time. Recombinant human USP47 was expressed in a baculovirus expression system and purified to homogeneity. The purified protein was shown to be a monomeric protein with a molecular mass of ∼146 kDa on sodium dodecyl sulphate-polyacrylamide gel electrophoresis. USP47 released Ub from Ub-aminoacyl-4-metheylcoumaryl-7-amide and Ub-tagged granzyme B. The substitution of the potential nucleophile Cys109 with Ser severely abrogated the Ub-releasing activity of USP47, indicating that USP47 is indeed a cysteine DUB. An assay using Ub dimer substrates showed that the enzyme cleaved a variety of isopeptide bonds between 2 Ub molecules, including the Lys48- and Lys63-linked isopeptide bonds. USP47 also released a Ub moiety from Lys48- and Lys63-linked polyUb chains. Of the inhibitors tested, N-ethylmaleimide, Zn ion and Ub aldehyde revealed a dose-dependent inhibition of USP47. In this study, clear differences in the enzymatic properties between USP47 and USP7 (the most closely related proteins among DUBs) were also found. Therefore, our results suggest that USP47 may play distinct roles in Ub-mediated cellular processes via DUB activity.


Asunto(s)
Ubiquitina Tiolesterasa/química , Ubiquitina/metabolismo , Sustitución de Aminoácidos , Baculoviridae , Electroforesis en Gel de Poliacrilamida , Inhibidores Enzimáticos/farmacología , Etilmaleimida/farmacología , Humanos , Cinética , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/química , Proteínas Recombinantes/aislamiento & purificación , Especificidad por Sustrato , Ubiquitina Tiolesterasa/antagonistas & inhibidores , Ubiquitina Tiolesterasa/aislamiento & purificación , Peptidasa Específica de Ubiquitina 7 , Proteasas Ubiquitina-Específicas , Ubiquitinación , Ubiquitinas/farmacología , Zinc/farmacología
16.
J Nutr ; 145(2): 322-7, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25644354

RESUMEN

BACKGROUND: Consuming seafood has health benefits, but seafood can also contain methylmercury, a neurotoxicant. Exposure to methylmercury affects children at different stages of brain development, including during adolescence. OBJECTIVE: The objective was to examine seafood consumption and blood mercury concentrations in US youth. METHODS: In the 2009-2012 NHANES, a cross-sectional nationally representative sample of the US population, seafood consumption in the past 30 d and blood mercury concentrations on the day of examination were collected from 5656 youth aged 1-19 y. Log-linear regression was used to examine the association between frequency of specific seafood consumption and blood mercury concentration, adjusting for race/Hispanic origin, sex, and age. RESULTS: In 2009-2012, 62.4% ± 1.4% (percent ± SE) of youth consumed any seafood in the preceding month; 38.4% ± 1.4% and 48.5% ± 1.5% reported consuming shellfish and fish, respectively. In 2009-2012, the geometric mean blood mercury concentration was 0.50 ± 0.02 µg/L among seafood consumers and 0.27 ± 0.01 µg/L among those who did not consume seafood. Less than 0.5% of youth had blood mercury concentrations ≥5.8 µg/L. In adjusted log-linear regression analysis, no significant associations were observed between frequency of breaded fish or catfish consumption and blood mercury concentrations, but frequency of consuming certain seafood types had significant positive association with blood mercury concentrations: high-mercury fish (swordfish and shark) [exponentiated ß coefficient (expß): 2.40; 95% CI: 1.23, 4.68]; salmon (expß: 1.41; 95% CI: 1.26, 1.55); tuna (expß: 1.38; 95% CI: 1.29, 1.45); crabs (expß: 1.35; 95% CI: 1.17, 1.55); shrimp (expß: 1.12; 95% CI: 1.05, 1.20), and all other seafood (expß: 1.23; 95% CI: 1.17, 1.32). Age-stratified log-linear regression analyses produced similar results. CONCLUSION: Few US youth have blood mercury concentrations ≥5.8 µg/L, although more than half of US youth consumed seafood in the past month.


Asunto(s)
Exposición a Riesgos Ambientales/análisis , Mercurio/sangre , Alimentos Marinos/análisis , Adolescente , Niño , Preescolar , Estudios Transversales , Femenino , Contaminación de Alimentos/análisis , Humanos , Lactante , Masculino , Política Nutricional/legislación & jurisprudencia , Encuestas Nutricionales , Medición de Riesgo , Estados Unidos , United States Environmental Protection Agency , Adulto Joven
17.
Am J Clin Nutr ; 99(5): 1066-70, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24522443

RESUMEN

BACKGROUND: Seafood is part of a healthy diet, but seafood can also contain methyl mercury-a neurotoxin. OBJECTIVE: The objective was to describe seafood consumption in US adults and to explore the relation between seafood consumption and blood mercury. DESIGN: Seafood consumption, obtained from a food-frequency questionnaire, and blood mercury data were available for 10,673 adults who participated in the 2007-2010 NHANES-a cross-sectional nationally representative sample of the US population. Seafood consumption was categorized by type (fish or shellfish) and by frequency of consumption (0, 1-2, 3-4, or ≥5 times/mo). Linear trends in geometric mean blood mercury concentrations by frequency of seafood consumption were tested. Logistic regression analyses examined the odds of blood mercury concentrations ≥5.8 µg/L (as identified by the National Research Council) based on frequency of the specific type of seafood consumed (included in the model as continuous variables) adjusted for sex, age, and race/Hispanic origin. RESULTS: In 2007-2010, 83.0% ± 0.7% (±SE) of adults consumed seafood in the preceding month. In adults consuming seafood, the blood mercury concentration increased as the frequency of seafood consumption increased (P < 0.001). In 2007-2010, 4.6% ± 0.39% of adults had blood mercury concentrations ≥5.8 µg/L. Results of the logistic regression on blood mercury concentrations ≥5.8 µg/L showed no association with shrimp (P = 0.21) or crab (P = 0.48) consumption and a highly significant positive association with consumption of high-mercury fish (adjusted OR per unit monthly consumption: 4.58; 95% CI: 2.44, 8.62; P < 0.001), tuna (adjusted OR: 1.14; 95% CI: 1.10, 1.17; P < 0.001), salmon (adjusted OR: 1.14; 95% CI: 1.09, 1.20; P < 0.001), and other seafood (adjusted OR: 1.12; 95% CI: 1.08, 1.15; P < 0.001). CONCLUSION: Most US adults consume seafood, and the blood mercury concentration is associated with the consumption of tuna, salmon, high-mercury fish, and other seafood.


Asunto(s)
Exposición a Riesgos Ambientales/análisis , Mercurio/sangre , Alimentos Marinos , Adulto , Animales , Estudios Transversales , Femenino , Contaminación de Alimentos/análisis , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Encuestas Nutricionales , Encuestas y Cuestionarios , Adulto Joven
18.
NCHS Data Brief ; (140): 1-8, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24429341

RESUMEN

Non-Hispanic Asian adults constituted 4.9% of the U.S. population in 2012, corresponding to 15.4 million people (2). This group primarily comprises persons of Chinese, Asian Indian, Korean, Filipino, Vietnamese, and Japanese descent. The prevalence of hypertension (defined as having blood pressure greater than or equal to 140/90 mm Hg or taking blood pressure-lowering medications) among non-Hispanic Asian adults aged 20 and over was 25.6%. As previously reported, this prevalence is similar to that of non-Hispanic white adults and Hispanic adults but lower than that of non-Hispanic black adults (3). Among non-Hispanic Asian adults, the prevalence of hypertension was higher among those who were older or had less education, similar to findings in U.S. adults overall (4,5). The prevalence of high total cholesterol (measured as cholesterol of at least 240 mg/dL) among non-Hispanic Asian adults was similar to that among adults of other race and Hispanic origin groups (6). Non-Hispanic Asian adults had a lower prevalence of low HDL cholesterol (measured as HDL less than 40 mg/dL) than Hispanic persons (6). Non-Hispanic Asian adult men were almost five times more likely than non-Hispanic Asian adult women to have low HDL cholesterol. While adult men in general are known to have a higher prevalence of low HDL cholesterol than adult women (7), the sex difference was larger than in other race and Hispanic origin groups (6). The prevalence of high BMI among non-Hispanic Asian adults (38.6%) was much lower than that previously reported for non-Hispanic white adults (66.7%), non-Hispanic black adults (76.7%), and Hispanic adults (78.8%) (8). BMI is widely used as a measure of body fat. However, at a given BMI level, body fat may vary by sex, age, and race and Hispanic origin. In particular, at a given BMI, Asian adults may have more body fat than white adults (9). Also, morbidity and mortality risk may be influenced by body composition and fat distribution in a manner that is not completely captured by BMI (10). This report builds on recently published estimates of hypertension, cholesterol, and obesity from NHANES 2011­2012 (3,6,11) by providing related estimates for Asian adults by select demographic characteristics. Hypertension, abnormal cholesterol levels, and elevated body weight are important risk factors for major chronic diseases, for which differences by race as well as ethnicity have been reported. The Asian population includes many ethnic groups, and the majority of non-Hispanic Asian adults in the United States are immigrants (12). Note that these estimates are for non-Hispanic Asian persons overall and may not reflect patterns for specific subgroups of Asian persons.


Asunto(s)
Asiático/estadística & datos numéricos , Índice de Masa Corporal , Dislipidemias/etnología , Hipertensión/etnología , Adulto , Factores de Edad , Anciano , Peso Corporal , Femenino , Humanos , Masculino , Persona de Mediana Edad , Encuestas Nutricionales , Obesidad/epidemiología , Prevalencia , Grupos Raciales/estadística & datos numéricos , Factores de Riesgo , Factores Sexuales , Factores Socioeconómicos , Estados Unidos/epidemiología
19.
Int J Environ Res Public Health ; 11(2): 1422-43, 2014 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-24473115

RESUMEN

CONTEXT: Cholinesterase (ChE) specific activity is the ratio of ChE activity to ChE mass and, as a biomarker of exposure to cholinesterase inhibitors, has a potential advantage over simple ChE activity. OBJECTIVE: To examine the association of several potential correlates (serum arylesterase/paraoxonase activity, serum albumin, sex, age, month of blood collection, and smoking) with plasma ChE specific activity. METHODS: We analyzed data from 195 cancer-free controls from a nested case-control study, accounting for potential confounding. RESULTS: Arylesterase activity had an independent, statistically significant positive association with ChE specific activity, and its magnitude was the greatest for the arylesterase phenotype corresponding to the QQ PON1192 genotype followed by phenotypes corresponding to QR and RR genotypes. Serum albumin was positively associated with ChE specific activity. CONCLUSIONS: Plasma arylesterase activity was positively associated with plasma ChE specific activity. This observation is consistent with protection conferred by a metabolic phenotype resulting in reduced internal dose.


Asunto(s)
Hidrolasas de Éster Carboxílico/sangre , Colinesterasas/sangre , Hidrolasas de Éster Carboxílico/genética , Colinesterasas/genética , Activación Enzimática/genética , Femenino , Humanos , Masculino , Organofosfatos/sangre , Fenotipo
20.
Analyst ; 139(3): 576-80, 2014 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-24326404

RESUMEN

We report a novel method for the selective proteolysis by limiting protease access to the substrate, which we have named nano-surface and molecular-orientation limited (nSMOL) proteolysis. We focus on the identification of the Fab and quantitation of antibodies. This method successfully performed limited proteolysis on the Fab.


Asunto(s)
Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/metabolismo , Regiones Determinantes de Complementariedad/metabolismo , Nanotecnología/métodos , Proteolisis , Tripsina/metabolismo , Secuencia de Aminoácidos , Regiones Determinantes de Complementariedad/química , Modelos Moleculares , Datos de Secuencia Molecular , Conformación Proteica , Propiedades de Superficie
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