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1.
Diabetes Metab ; 42(3): 162-9, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26782010

RESUMEN

OBJECTIVE: Accumulating evidence has linked elevated parathyroid hormone (PTH) with insulin resistance, beta cell dysfunction and dysglycaemia, however, its role in the development of diabetes is largely unclear, particularly among non-whites. We sought to examine the association of PTH with the incidence of diabetes. METHODS: We studied 8066 white and 2034 black adults aged 46-70 years at baseline (1990-92) from the ARIC Study with follow-up for incident diabetes ascertained during study visits conducted in 1993-95 and 1996-98. Hazard ratios (HR) and their 95% CIs for diabetes adjusted for demographics, lifestyle, and 25-hydroxyvitamin D were estimated according to PTH measured at baseline. RESULTS: PTH was higher among blacks than whites (median [IQR], 43.8 [35.0-55.8] vs. 37.9 [30.4-47.3] pg/mL; P<0.001). During a median follow-up of 6 years, 498 white and 167 black participants developed diabetes. The association of PTH with diabetes varied significantly by race (P-interaction 0.02). PTH was not associated with risk for diabetes among black adults. Among whites, HRs according to quintiles of PTH were 1 (referent), 0.95 (0.71, 1.29), 0.95 (0.70, 1.28), 1.12 (0.84, 1.51), and 1.31 (0.98, 1.76) (P-trend 0.03). When a clinical cut-point for PTH was applied (≥65pg/mL; 5.7% of whites), the HR for diabetes among whites was 1.38 (1.01, 1.88). Results were similar when restricted to participants with normal baseline kidney function. CONCLUSION: In this large, population-based study, elevated PTH was independently associated with risk for diabetes among white, but not black adults. Further studies are needed to elucidate the mechanisms that may underlie this differential association of PTH with diabetes across race groups.


Asunto(s)
Negro o Afroamericano/estadística & datos numéricos , Diabetes Mellitus/sangre , Diabetes Mellitus/etnología , Hormona Paratiroidea/sangre , Población Blanca/estadística & datos numéricos , Adulto , Anciano , Aterosclerosis/epidemiología , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Características de la Residencia , Factores de Riesgo
2.
Prostate Cancer Prostatic Dis ; 16(1): 107-10, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23146972

RESUMEN

BACKGROUND: The ratio of the second to the fourth digit (2D:4D ratio) is a sexually dimorphic trait established in utero that differs between ethnic groups. It is associated with prenatal androgen exposure, and studies have evaluated the ratio as a marker for certain traits and disease states known to be associated with higher levels of in utero androgens, such as prostate cancer. There are currently no screening tools that stratify men with prostate cancer according to the severity of their disease. This study aims to investigate the 2D:4D ratio as a potential marker for prostate cancer severity. Our hypothesis was that lower digit ratios, representing higher in utero androgen exposure, would be associated with more severe disease. METHODS: Measurements were taken of the second and fourth digits of the right hand of male patients diagnosed with prostate cancer. Gleason score, presence of metastasis, family history, age at diagnosis and race were recorded. The distribution of demographic and other patient characteristics were compared with digit ratios to determine relationships. RESULTS: African-American men with prostate cancer are 3.70 times more likely to have a low 2D:4D digit ratio than Caucasian men with prostate cancer (95% confidence interval: 1.98, 6.92; P < 0.0001). There were no statistically significant differences in the presence of metastasis, Gleason score, family history or age at diagnosis by digit ratio. CONCLUSION: 2D:4D ratio shows strong differences between African-Americans and Caucasians; however, it does not correlate with disease severity in men already diagnosed with prostate cancer. Although this is a small population sample with possible confounding factors, it does not provide evidence to support the hypothesis that prenatal androgens affect prostate cancer grade or progression.


Asunto(s)
Antropometría , Dedos/anatomía & histología , Neoplasias de la Próstata/patología , Humanos , Masculino , Persona de Mediana Edad , Caracteres Sexuales
3.
Eur J Clin Nutr ; 67(1): 58-63, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23187956

RESUMEN

BACKGROUND/OBJECTIVES: Cardiovascular disease (CVD) is the leading cause of death in the United States and the world. Clinical trials have suggested that soybean protein lowers lipids and blood pressure. The effect of soybean protein on novel CVD risk factors has not been well studied. The objective of this study was to examine the effect of soybean protein on biomarkers of inflammation, endothelial dysfunction and adipocytokines. SUBJECTS/METHODS: The effect of 8 weeks of 40 g of soybean protein supplement (89.3 mg isoflavones), 40 g of milk protein supplement and 40 g of complex carbohydrate placebo was examined in a randomized, placebo-controlled, double-blind, three-phase crossover trial among adults in New Orleans, Louisiana and Jackson, Mississippi. Plasma levels of inflammation biomarkers (C-reactive protein, interleukin-6, tumor necrosis factor-α), endothelial dysfunction biomarkers (E-selectin, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, thrombomodulin) and adipocytokines (high-molecular weight adiponectin, leptin, resistin) were measured at baseline and at the end of each intervention using immunoturbidimetric and enzyme-linked immunosorbent assay techniques. RESULTS: Soy protein supplementation resulted in a significant mean net change (95% confidence interval) in plasma E-selectin of -3.93 ng/ml (-7.05 to -0.81 ng/ml; P=0.014) compared with milk protein, and in plasma leptin of -2089.8 pg/ml (-3689.3 to -490.3 pg/ml; P=0.011) compared with carbohydrate. There were no significant changes in any other risk factors. CONCLUSIONS: Soy protein supplementation may reduce levels of E-selectin and leptin. Further research is warranted to investigate the mechanisms through which protein may confer protective effects on novel CVD risk factors.


Asunto(s)
Enfermedades Cardiovasculares/prevención & control , Suplementos Dietéticos , Selectina E/sangre , Endotelio Vascular/fisiopatología , Leptina/sangre , Proteínas de Soja/uso terapéutico , Adipoquinas/sangre , Adulto , Biomarcadores/sangre , Enfermedades Cardiovasculares/sangre , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/fisiopatología , Estudios Cruzados , Método Doble Ciego , Femenino , Humanos , Mediadores de Inflamación/sangre , Louisiana/epidemiología , Masculino , Persona de Mediana Edad , Proteínas de la Leche/uso terapéutico , Mississippi/epidemiología , Factores de Riesgo
4.
Br J Cancer ; 107(2): 234-42, 2012 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-22722311

RESUMEN

BACKGROUND: Little is known about engagement in multiple health behaviours in childhood cancer survivors. METHODS: Using latent class analysis, we identified health behaviour patterns in 835 adult survivors of childhood cancer (age 20-35 years) and 1670 age- and sex-matched controls from the general population. Behaviour groups were determined from replies to questions on smoking, drinking, cannabis use, sporting activities, diet, sun protection and skin examination. RESULTS: The model identified four health behaviour patterns: 'risk-avoidance', with a generally healthy behaviour; 'moderate drinking', with higher levels of sporting activities, but moderate alcohol-consumption; 'risk-taking', engaging in several risk behaviours; and 'smoking', smoking but not drinking. Similar proportions of survivors and controls fell into the 'risk-avoiding' (42% vs 44%) and the 'risk-taking' cluster (14% vs 12%), but more survivors were in the 'moderate drinking' (39% vs 28%) and fewer in the 'smoking' cluster (5% vs 16%). Determinants of health behaviour clusters were gender, migration background, income and therapy. CONCLUSION: A comparable proportion of childhood cancer survivors as in the general population engage in multiple health-compromising behaviours. Because of increased vulnerability of survivors, multiple risk behaviours should be addressed in targeted health interventions.


Asunto(s)
Conductas Relacionadas con la Salud , Estilo de Vida , Neoplasias/epidemiología , Sobrevivientes/psicología , Adolescente , Adulto , Consumo de Bebidas Alcohólicas/epidemiología , Dieta , Femenino , Estudios de Seguimiento , Humanos , Masculino , Abuso de Marihuana/epidemiología , Factores de Riesgo , Asunción de Riesgos , Fumar/epidemiología , Deportes , Suiza/epidemiología
5.
Eur J Clin Nutr ; 66(4): 419-25, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21952693

RESUMEN

BACKGROUND/OBJECTIVE: Previous clinical trials have documented that soy protein reduces low-density lipoprotein cholesterol and increases high-density lipoprotein (HDL) cholesterol compared with milk protein. However, the effect of soy protein on lipids compared with carbohydrate has not been not well studied. We examined the effect of soy and milk protein supplementation on lipids and lipoproteins compared with carbohydrate among adults without hypercholesterolemia. SUBJECTS/METHODS: We conducted a randomized, double-blind, 3-phase crossover trial among 352 US adults with serum total cholesterol level of <240 mg/dl from September 2003 to April 2008. Trial participants were assigned to 40 g/day supplementation of soy protein, milk protein or complex carbohydrate from wheat each for 8 weeks in random order with a 3-week washout period between interventions. Overnight fasting blood samples were collected at the termination of each intervention phase. RESULTS: Compared with carbohydrate, soy protein supplementation was significantly associated with a net change (95% confidence interval (CI)) in total cholesterol and total/HDL cholesterol ratio of -3.97 mg/dl (-7.63 to -0.31, P=0.03) and -0.12 (-0.23 to -0.01, P=0.03), respectively. Compared with milk protein, soy protein supplementation was significantly associated with a net change (95% CI) in HDL and total/HDL cholesterol ratio of 1.54 mg/dl (0.63 to 2.44, P=0.0009) and -0.14 (-0.22 to -0.05, P=0.001), respectively. Compared with carbohydrate, milk protein supplementation was significantly associated with a net change (95% CI) in HDL of -1.13 mg/dl (-2.05 to -0.22, P=0.02). CONCLUSIONS: This randomized controlled trial indicates that soy protein, but not milk protein, supplementation improves the lipid profile among healthy individuals.


Asunto(s)
HDL-Colesterol/sangre , LDL-Colesterol/sangre , Suplementos Dietéticos , Proteínas de la Leche/administración & dosificación , Proteínas de Soja/administración & dosificación , Adulto , HDL-Colesterol/efectos de los fármacos , LDL-Colesterol/efectos de los fármacos , Estudios Cruzados , Carbohidratos de la Dieta/administración & dosificación , Método Doble Ciego , Femenino , Humanos , Hipercolesterolemia/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Triglicéridos/sangre
6.
Talanta ; 87: 126-35, 2011 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-22099659

RESUMEN

Nuclear waste repositories are being installed in deep excavated rock formations in some places in Europe to isolate and store radioactive waste. In France, the Callovo-Oxfordian formation (COx) is a possible candidate for nuclear waste storage. This work investigates the applicability of CeO(2)-based oxides (CeO(2), Ce(0.8)Sm(0.2)O(2) and Ce(0.8)Zr(0.2)O(2)) for monitoring the pH of the COx pore water (T=25°C). The study is limited to the pH range between 5.5 and 13.2, which includes the pH values that have been encountered or are anticipated in the COx formation during its evolution as radioactive waste repository due mainly to alkalinisation, an increase in salinity, and a decrease in redox potential. Screen-printing was done to assemble electrodes and rapidly generate data sets. The electrochemical behavior of CeO(2)-based screen-printed electrodes (CeO(2)-based SPEs) was determined by cyclic voltammetry and electrochemical impedance spectroscopy. The use of the electrodes for pH sensing was then evaluated by potentiometric measurements. The feasibility of measuring pH with CeO(2)-based SPEs was first tested in NH(4)Cl/NH(3) buffer solutions, leading to electrode calibration over the widest range of pH, from around neutral to basic pH. Experiments were then conducted in NaHCO(3)/Na(2)CO(3) buffer samples similar to conditions prevailing in the COx formation. Ce(0.8)Zr(0.2)O(2) SPEs exhibit a near-Nernstian behavior (sensitivity -(51±2)mV/pH) in the pH range of 5.5-13.2 at 25°C. Electrode response was slightly affected by the direction of the pH change. Electrode reliability was clearly demonstrated for pH monitoring. Probes based on the same components, but more durably designed, could be considered for pH measurements in radioactive waste repositories.


Asunto(s)
Cesio/química , Concentración de Iones de Hidrógeno , Óxidos/química , Potenciometría/instrumentación , Electrodos , Diseño de Equipo , Reproducibilidad de los Resultados
7.
Nanotechnology ; 21(46): 465606, 2010 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-20975211

RESUMEN

γ-Al(2)O(3) is a well known catalyst support. The addition of Ce to γ-Al(2)O(3) is known to beneficially retard the phase transformation of γ-Al(2)O(3) to α-Al(2)O(3) and stabilize the γ-pore structure. In this work, Ce-doped γ-Al(2)O(3) nanowires have been prepared by a novel method employing an anodic aluminium oxide (AAO) template in a 0.01 M cerium nitrate solution, assisted by urea hydrolysis. Calcination at 500 °C for 6 h resulted in the crystallization of the Ce-doped AlOOH gel to form Ce-doped γ-Al(2)O(3) nanowires. Ce(3+) ions within the nanowires were present at a concentration of < 1 at.%. On the template surface, a nanocrystalline CeO(2) thin film was deposited with a cubic fluorite structure and a crystallite size of 6-7 nm. Characterization of the nanowires and thin films was performed using scanning electron microscopy, transmission electron microscopy, electron energy loss spectroscopy, x-ray photoelectron spectroscopy and x-ray diffraction. The nanowire formation mechanism and urea hydrolysis kinetics are discussed in terms of the pH evolution during the reaction. The Ce-doped γ-Al(2)O(3) nanowires are likely to find useful applications in catalysis and this novel method can be exploited further for doping alumina nanowires with other rare earth elements.

8.
Nanotechnology ; 21(32): 325601, 2010 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-20639583

RESUMEN

We report the room temperature (RT) synthesis of silver vanadate nanorods (consisting of mainly beta-AgV O(3)) by a simple wet chemical route and their frictional study at high temperatures (HT). The sudden mixing of ammonium vanadate with silver nitrate solution under constant magnetic stirring resulted in a pale yellow coloured precipitate. Structural/microstructural characterization of the precipitate through x-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed the high yield and homogeneous formation of silver vanadate nanorods. The length of the nanorods was 20-40 microm and the thickness 100-600 nm. The pH variation with respect to time was thoroughly studied to understand the formation mechanism of the silver vanadate nanorods. This synthesis process neither demands HT, surfactants nor long reaction time. The silver vanadate nanomaterial showed good lubrication behaviour at HT (700 degrees C) and the friction coefficient was between 0.2 and 0.3. HT-XRD revealed that AgV O(3) completely transformed into silver vanadium oxide (Ag(2)V(4)O(11)) and silver with an increase in temperature from RT to 700 degrees C.

9.
Nanotechnology ; 18(49): 495604, 2007 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-20442478

RESUMEN

Porous alumina has attracted a great deal of attention as a template material for the growth of nanowires and nanodots. Typically, the pores have a high aspect ratio, which forbid the use of evaporation techniques for filling them, due to a pore closure effect. For this reason electrochemical methods are mainly used. However, there are materials, such as Al, which are very difficult to deposit electrochemically. In this work, the fabrication of Al nanorods by electron gun evaporation into low aspect-ratio pores of ultra-thin porous alumina templates is described. The thicknesses of the templates are in the range from 50 to 70 nm, while their pores have diameters from 20 to 40 nm, i.e. their diameter:height aspect ratios are very low, from 1:1.5 to 1:3. These properties make it possible to completely fill the pores with evaporation techniques. This method can be generalized to any target and substrate material.

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