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1.
Artículo en Inglés | MEDLINE | ID: mdl-38428676

RESUMEN

The aim of this study is to describe the anaesthesia management of two patients undergoing carinal resection under veno-venous extracorporeal membrane oxygenation (VV ECMO). In both cases, anaesthesia was induced and then maintained with inhalational agents during pneumonectomy and mediastinoscopy (respectively). Then the jugular and femoral veins were cannulated and VV ECMO was started after heparinization. One of the patients presented bleeding during surgery, which was treated with low-dose vasopressors (norepinephrine) and transfusion of platelets, fresh frozen plasma, and concentrated red blood cells. During VV ECMO, anaesthesia was maintained with target-controlled infusion of propofol. VV ECMO can be expected to improve surgical conditions in tracheal surgery; however, it is still a novel technique in this context. In selected patients, it would guarantee ventilatory support during carinal resection, but it is essential to carefully plan anaesthesia maintenance and prepare for VV ECMO-related complications. This technique should only be used in tertiary centres with experience in VV ECMO management.


Asunto(s)
Oxigenación por Membrana Extracorpórea , Tráquea , Humanos , Oxigenación por Membrana Extracorpórea/métodos , Masculino , Tráquea/cirugía , Persona de Mediana Edad , Femenino , Neumonectomía/métodos , Neoplasias de la Tráquea/cirugía , Anciano , Adulto , Pérdida de Sangre Quirúrgica/prevención & control
2.
Leukemia ; 30(1): 14-23, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26126967

RESUMEN

Transcriptional dysregulation is associated with haematological malignancy. Although mutations of the key haematopoietic transcription factor PU.1 are rare in human acute myeloid leukaemia (AML), they are common in murine models of radiation-induced AML, and PU.1 downregulation and/or dysfunction has been described in human AML patients carrying the fusion oncogenes RUNX1-ETO and PML-RARA. To study the transcriptional programmes associated with compromised PU.1 activity, we adapted a Pu.1-mutated murine AML cell line with an inducible wild-type PU.1. PU.1 induction caused transition from leukaemia phenotype to monocytic differentiation. Global binding maps for PU.1, CEBPA and the histone mark H3K27Ac with and without PU.1 induction showed that mutant PU.1 retains DNA-binding ability, but the induction of wild-type protein dramatically increases both the number and the height of PU.1-binding peaks. Correlating chromatin immunoprecipitation (ChIP) Seq with gene expression data, we found that PU.1 recruitment coupled with increased histone acetylation induces gene expression and activates a monocyte/macrophage transcriptional programme. PU.1 induction also caused the reorganisation of a subgroup of CEBPA binding peaks. Finally, we show that the PU.1 target gene set defined in our model allows the stratification of primary human AML samples, shedding light on both known and novel AML subtypes that may be driven by PU.1 dysfunction.


Asunto(s)
Leucemia Mieloide Aguda/genética , Proteínas Proto-Oncogénicas/fisiología , Transactivadores/fisiología , Transcripción Genética , Acetilación , Proteína alfa Potenciadora de Unión a CCAAT/metabolismo , Diferenciación Celular , Línea Celular Tumoral , ADN/metabolismo , Genoma Humano , Histonas/metabolismo , Humanos , Monocitos/citología , Monocitos/metabolismo
3.
Leukemia ; 28(1): 88-97, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23929215

RESUMEN

Small molecule inhibition of the BET family of proteins, which bind acetylated lysines within histones, has been shown to have a marked therapeutic benefit in pre-clinical models of mixed lineage leukemia (MLL) fusion protein-driven leukemias. Here, we report that I-BET151, a highly specific BET family bromodomain inhibitor, leads to growth inhibition in a human erythroleukemic (HEL) cell line as well as in erythroid precursors isolated from polycythemia vera patients. One of the genes most highly downregulated by I-BET151 was LMO2, an important oncogenic regulator of hematopoietic stem cell development and erythropoiesis. We previously reported that LMO2 transcription is dependent upon Janus kinase 2 (JAK2) kinase activity in HEL cells. Here, we show that the transcriptional changes induced by a JAK2 inhibitor (TG101209) and I-BET151 in HEL cells are significantly over-lapping, suggesting a common pathway of action. We generated JAK2 inhibitor resistant HEL cells and showed that these retain sensitivity to I-BET151. These data highlight I-BET151 as a potential alternative treatment against myeloproliferative neoplasms driven by constitutively active JAK2 kinase.


Asunto(s)
Neoplasias Hematológicas/patología , Janus Quinasa 2/metabolismo , Trastornos Mieloproliferativos/patología , Proteínas Oncogénicas/antagonistas & inhibidores , Línea Celular Tumoral , Inmunoprecipitación de Cromatina , Neoplasias Hematológicas/enzimología , Neoplasias Hematológicas/metabolismo , Humanos , Trastornos Mieloproliferativos/enzimología , Trastornos Mieloproliferativos/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
4.
Oncogene ; 32(48): 5471-80, 2013 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-23708655

RESUMEN

The Lim Domain Only 2 (LMO2) leukaemia oncogene encodes an LIM domain transcriptional cofactor required for early haematopoiesis. During embryogenesis, LMO2 is also expressed in developing tail and limb buds, an expression pattern we now show to be recapitulated in transgenic mice by an enhancer in LMO2 intron 4. Limb bud expression depended on a cluster of HOX binding sites, while posterior tail expression required the HOX sites and two E-boxes. Given the importance of both LMO2 and HOX genes in acute leukaemias, we further demonstrated that the regulatory hierarchy of HOX control of LMO2 is activated in leukaemia mouse models as well as in patient samples. Moreover, Lmo2 knock-down impaired the growth of leukaemic cells, and high LMO2 expression at diagnosis correlated with poor survival in cytogenetically normal AML patients. Taken together, these results establish a regulatory hierarchy of HOX control of LMO2 in normal development, which can be resurrected during leukaemia development. Redeployment of embryonic regulatory hierarchies in an aberrant context is likely to be relevant in human pathologies beyond the specific example of ectopic activation of LMO2.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/genética , Regulación del Desarrollo de la Expresión Génica/genética , Genes Homeobox , Proteínas con Dominio LIM/genética , Mesodermo/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/embriología , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Proteínas Proto-Oncogénicas/genética , Proteínas Adaptadoras Transductoras de Señales/deficiencia , Animales , Secuencia de Bases , Línea Celular Tumoral , Proliferación Celular , Cromatina/genética , Secuencia Conservada , Elementos E-Box , Extremidades/embriología , Técnicas de Silenciamiento del Gen , Proteínas de Homeodominio/metabolismo , Humanos , Intrones/genética , Proteínas con Dominio LIM/deficiencia , Ratones , Datos de Secuencia Molecular , Fenotipo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patología , Proteínas Proto-Oncogénicas/deficiencia , Activación Transcripcional/genética
5.
Leukemia ; 27(6): 1348-57, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23302769

RESUMEN

LMO1 is a transcriptional regulator and a T-acute lymphoblastic leukaemia (T-ALL) oncogene. Although first identified in association with a chromosomal translocation in T-ALL, the ectopic expression of LMO1 occurs far more frequently in the absence of any known mutation involving its locus. Given that LMO1 is barely expressed in any haematopoietic lineage, and activation of transcriptional drivers in leukaemic cells is not well described, we investigated the regulation of this gene in normal haematopoietic and leukaemic cells. We show that LMO1 has two promoters that drive reporter gene expression in transgenic mice to neural tissues known to express endogenous LMO1. The LMO1 promoters display bivalent histone marks in multiple blood lineages including T-cells, and a 3' flanking region at LMO1 +57 contains a transcriptional enhancer that is active in developing blood cells in transgenic mouse embryos. The LMO1 promoters become activated in T-ALL together with the 3' enhancer, which is bound in primary T-ALL cells by SCL/TAL1 and GATA3. Taken together, our results show that LMO1 is poised for expression in normal progenitors, where activation of SCL/TAL1 together with a breakdown of epigenetic repression of LMO1 regulatory elements induces ectopic LMO1 expression that contributes to the development and maintenance of T-ALL.


Asunto(s)
Proteínas de Unión al ADN/genética , Elementos de Facilitación Genéticos , Proteínas con Dominio LIM/genética , Oncogenes , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Regiones Promotoras Genéticas , Factores de Transcripción/genética , Animales , Inmunoprecipitación de Cromatina , Humanos , Ratones , Ratones Transgénicos
6.
BMC Public Health ; 12: 27, 2012 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-22236142

RESUMEN

BACKGROUND: The authors examined factors associated with nutritional resilience/vulnerability among preschoolers in the Gaza Strip in 2007, where political violence and deprivation are widespread. METHODS: This cross-sectional study was carried out in 2007 using random sampling of kindergartens in order to select 350 preschoolers. Binary logistic regression was used to compare resilient (adequate nutrition) and vulnerable (stunted) groups with those with moderate nutrition. RESULTS: Approximately 37% of the subjects demonstrated nutritional resilience and 15% were vulnerable. Factors associated with nutritional resilience were child younger age, normal birth weight, actively hand- or spoon-feeding when the child was below two years, and residential stability in the past two years. The only factor associated with nutritional vulnerability was lower total score on the mother's General Health Questionnaire, which we interpret as a marker of maternal mental health. CONCLUSIONS: Children with low-birth weight and older children had worse nutritional resiliency outcomes. Further, poorer outcomes for children were associated with lower maternal mental health status, as well as increased family residential instability. Our results add to the large literature on the pervasive effects of violence and instability on children and underscore the need for resources for early intervention and for the urgent resolution of the Palestinian and other armed conflicts.


Asunto(s)
Árabes/estadística & datos numéricos , Trastornos de la Nutrición del Niño/epidemiología , Estado Nutricional , Poblaciones Vulnerables , Distribución por Edad , Peso al Nacer , Niño , Preescolar , Estudios Transversales , Femenino , Humanos , Masculino , Medio Oriente/epidemiología , Madres/psicología , Política , Factores de Riesgo , Factores Socioeconómicos , Violencia
7.
Ann N Y Acad Sci ; 1170: 543-52, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19686191

RESUMEN

Taste or gustatory function may play an important role in determining diet and nutritional status and therefore indirectly impact health. Yet there have been few attempts to study the spectrum of taste function and dysfunction in human populations. Epidemiologic studies are needed to understand the impact of taste function and dysfunction on public health, to identify modifiable risk factors, and to develop and test strategies to prevent clinically significant dysfunction. However, measuring taste function in epidemiologic studies is challenging and requires repeatable, efficient methods that can measure change over time. Insights gained from translating laboratory-based methods to a population-based study, the Beaver Dam Offspring Study (BOSS) will be shared. In this study, a generalized labeled magnitude scale (gLMS) method was used to measure taste intensity of filter paper disks saturated with salt, sucrose, citric acid, quinine, or 6-n-propylthiouracil, and a gLMS measure of taste preferences was administered. In addition, a portable, inexpensive camera system to capture digital images of fungiform papillae and a masked grading system to measure the density of fungiform papillae were developed. Adult children of participants in the population-based Epidemiology of Hearing Loss Study in Beaver Dam, Wisconsin, are eligible for this ongoing study. The parents were residents of Beaver Dam and 43-84 years of age in 1987-1988; offspring ranged in age from 21-84 years in 2005-2008. Methods will be described in detail and preliminary results about the distributions of taste function in the BOSS cohort will be presented.


Asunto(s)
Trastornos del Gusto/epidemiología , Adulto , Anciano , Anciano de 80 o más Años , Humanos , Persona de Mediana Edad , Vigilancia de la Población , Lengua/anatomía & histología , Wisconsin/epidemiología
8.
Chem Senses ; 34(5): 435-40, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19363087

RESUMEN

This study described the San Diego Odor Identification Test (SDOIT) reliability and compared the SDOIT and the Brief Smell Identification Test (B-SIT). Ninety participants aged 50-70 years completed this 2-visit olfaction study. During visit 1, the SDOIT and B-SIT were administered according to standard protocols. Three weeks later, participants returned to retake the SDOIT. The SDOIT score was the total number of odorants correctly identified out of 8 odorants presented, and olfactory impairment was defined as correctly identifying less than 6 odorants. The B-SIT score was the total number of odorants correctly identified out of 12 odorants presented, and participants correctly identifying less than 9 odorants were categorized as abnormal. The SDOIT reliability was high (concordance correlation coefficient = 0.85, 95% confidence interval [CI] = 0.79-0.91). The same score was obtained on retest for 73% of participants, whereas 18% improved, and 9% declined. Test-retest agreement was 96% for the SDOIT; 4% improved from impaired at visit 1 to unimpaired at visit 2. Overall, SDOIT impairment classification and B-SIT abnormal classification agreed in 96% of participants (kappa = 0.81, 95% CI = 0.63-0.99). In conclusion, the SDOIT showed good test-retest reliability. Agreement for impaired/abnormal olfaction was demonstrated for the SDOIT and the B-SIT.


Asunto(s)
Odorantes/análisis , Olfato/fisiología , Anciano , Métodos Epidemiológicos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reconocimiento en Psicología , Reproducibilidad de los Resultados , Umbral Sensorial/fisiología
9.
J Epidemiol Community Health ; 62(3): 239-44, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18272739

RESUMEN

AIM: To describe changes in leisure time and occupational physical activity status in an urban Mediterranean population-based cohort, and to evaluate sociodemographic, health-related and lifestyle correlates of such changes. METHODS: Data for this study come from the Cornellè Health Interview Survey Follow-Up Study, a prospective cohort study of a representative sample (n = 2500) of the population. Participants in the analysis reported here include 1246 subjects (567 men and 679 women) who had complete data on physical activity at the 1994 baseline survey and at the 2002 follow-up. We fitted Breslow-Cox regression models to assess the association between correlates of interest and changes in physical activity. RESULTS: Regarding leisure time physical activity, 61.6% of cohort members with "sedentary" habits in 1994 changed their status to "light/moderate" physical activity in 2002, and 70% who had "light/moderate" habits in 1994 did not change their activity level. Regarding occupational physical activity, 74.4% of cohort members who were "active" did not change their level of activity, and 64.3% of participants with "sedentary" habits in 1994 changed to "active" occupational physical activity. No clear correlates of change in physical activity were identified in multivariate analyses. CONCLUSION: While changes in physical activity are evident in this population-based cohort, no clear determinants of such changes were recognised. Further longitudinal studies including other potential individual and contextual determinants are needed to better understand determinants of changes in physical activity at the population level.


Asunto(s)
Actividades Recreativas , Actividad Motora , Salud Laboral/estadística & datos numéricos , Adolescente , Adulto , Anciano , Métodos Epidemiológicos , Femenino , Conductas Relacionadas con la Salud , Humanos , Estilo de Vida , Masculino , Persona de Mediana Edad , España , Salud Urbana/tendencias
10.
Langmuir ; 22(25): 10472-82, 2006 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-17129018

RESUMEN

The topography of platinum electrodes produced by electrodeposition (19 to 200 mC cm-2) on highly oriented pyrolytic graphite (HOPG) under different potential modulations was investigated by atomic force microscopy, scanning tunneling microscopy, and H-atom electrosorption voltammetry. To modulate electrodeposition, (i) triangular potential cycling at 0.1 V s-1, (ii) a linear cathodic potential at 0.1 V s-1 and anodic potential step cycling, and (iii) square wave potential cycling at 5000 Hz were utilized. AFM and STM imaging showed that at lower platinum loading the HOPG surface was partially covered by a 3D sublayer of platinum. Electrodes produced by procedure (i) were made of faceted platinum aggregates of about 200 nm and nanoclusters in the range of 5-20 nm; those that resulted from procedure (ii) consisted of anisotropic aggregates of nanoclusters arranged as quasi-parallel domains. These electrodes from (i) and (ii) behaved as fractal objects. The electrodes resulting from procedure (iii) exhibited a flat surface that behaved as a Euclidean object. For all WEs, as the platinum loading was increased the HOPG surface was fully covered by a thin 3D layer of platinum aggregates produced by electrodeposition and coalescence phenomena. Large platinum loading led to electrodes with fractal geometry. Statistical parameters (root-mean-square height, skewedness, kurtosis, anisotropy, Abbot curve, number of protrusions and valleys, and fractal dimension) were obtained from the analysis of AFM and STM imaging data. Platinum electrodeposition coupled to either H-adatom formation for procedures (i) and (ii) or phonon dispersion for (iii) was involved in the surface atom rearrangements related to electrofaceting. The H-adatom electrosorption voltammetry data were used to evaluate the real electrode surface area via the voltammetric charge and to advance a tentative explanation of the contribution of the different crystallographic facets to the global electrochemical process dominated by weak H-Pt adsorption interactions.

11.
J Hum Hypertens ; 20(12): 937-45, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17024135

RESUMEN

Increasing experimental evidence, including recently developed animal models support a causal role for uric acid in the development of hypertension. However, it is not clear whether serum uric acid levels are independently associated with the long-term incidence of hypertension. We examined the association between serum uric acid levels and 10-year incidence of hypertension in a population-based cohort study based in Beaver Dam city and township, Wisconsin, US. We studied 2520 hypertension-free individuals (56.3% women, age: 43-84 years, 98% Caucasian) at the baseline examination (1988-1990). The main outcome of interest was hypertension (systolic blood pressure (BP) of 140 mm Hg or higher, diastolic BP 90 mm Hg or higher, or combination of self-reported high BP diagnosis and use of antihypertensive medications) incidence over 10 years among baseline normotensive individuals. Nine hundred and fifty-six individuals developed hypertension over a 10-year follow-up period. The relative risk (RR) (95% confidence intervals (CI)) of incident hypertension increased in a dose-dependent manner (P-trend < 0.05 in all models) with increasing uric acid quartiles. Multivariable RR (95% CI) comparing the highest quartile of serum uric acid (> or =390 micromol/l) to the lowest quartile (< or =260 micromol/l) was 1.65 (1.41-1.93). This association persisted in subgroup analyses by categories of smoking, alcohol intake, body mass index, baseline blood pressure and estimated glomerular filtration rate (GFR). In conclusion, increasing quartiles of serum uric acid was associated with 10-year incidence of hypertension independent of smoking, alcohol intake and baseline kidney function suggesting an independent positive association between serum uric acid levels and hypertension development among community-dwelling older adults.


Asunto(s)
Hipertensión/epidemiología , Ácido Úrico/sangre , Adulto , Anciano , Anciano de 80 o más Años , Presión Sanguínea , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Tasa de Filtración Glomerular , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Población Urbana , Wisconsin/epidemiología
12.
Prev Med ; 36(3): 330-9, 2003 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-12634024

RESUMEN

BACKGROUND: To examine associations of weight loss and changes in fat distribution with changes in blood pressure and the remission of hypertension in a community-based sample. METHODS: Participants were 3245 white and African-American men and women, 45-64 years of age, who participated in the Atherosclerosis Risk in Communities Study over an average of 9 years. Mixed models analyses were used to examine the associations of weight loss and changes in fat distribution with changes in blood pressure. Proportional hazard models with time-dependent covariates were used to examine the associations of weight loss and changes in fat distribution with the remission of hypertension. RESULTS: Weight loss was associated with a decrease in systolic blood pressure and diastolic blood pressure and with an increased rate of remission of hypertension. Hazard ratios of the remission of hypertension associated with 1-kg increment in annual weight loss were 2.04 (95% confidence interval [CI]: 1.62-2.59), 1.38 (95% CI: 1.14-1.67), 1.84 (95% CI: 1.47-2.29), and 1.53 (95% CI: 1.14-2.05) for white women, African-American women, white men, and African-American men, respectively. Changes in fat distribution were associated with the remission of hypertension in younger (45-54 years) participants. CONCLUSIONS: Weight loss was associated with a decrease in blood pressure and with remission of hypertension in white and African-American men and women.


Asunto(s)
Arteriosclerosis/epidemiología , Negro o Afroamericano/estadística & datos numéricos , Composición Corporal , Hipertensión/epidemiología , Obesidad/etnología , Obesidad/prevención & control , Prevención Primaria/organización & administración , Pérdida de Peso , Población Blanca/estadística & datos numéricos , Distribución por Edad , Arteriosclerosis/prevención & control , Índice de Masa Corporal , Estudios de Cohortes , Comorbilidad , Intervalos de Confianza , Femenino , Humanos , Hipertensión/prevención & control , Incidencia , Masculino , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Factores de Riesgo , Distribución por Sexo , Estados Unidos/epidemiología
13.
Int J Obes Relat Metab Disord ; 26(1): 58-64, 2002 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11791147

RESUMEN

OBJECTIVE: To examine associations between weight gain and changes in blood pressure and the incidence of hypertension in four ethnicity-gender groups. DESIGN: Longitudinal closed cohort studied over an average of 6 y. SUBJECTS: Total of 9309 white and African-American men and women 45-64 y of age who participated in the Atherosclerosis Risk in Communities (ARIC) Study. METHODS: Weight and blood pressure were measured at baseline and after an average of 3 and 6 y of follow-up. Proportional hazard models with weight gain as a time-dependent variable were used to examine the association between weight gain and changes in blood pressure and hypertension. Multivariate models were used with baseline SBP, DBP, age, BMI, height, WHR, smoking, physical activity, education, caloric intake, fat intake and study center as covariates. RESULTS: Weight gain was associated with increases in SBP and DBP in all groups. Hazard ratios for hypertension associated with 1 kg annual weight gain were 1.36 (95% CI, 1.29, 1.45) in white women, 1.12 (95% CI, 1.03, 1.21) in African-American women, 1.35 (95% CI, 1.27, 1.43) in white men and 1.43 (95% CI, 1.27,1.61) in African-American men. CONCLUSION: Weight gain was associated with increased blood pressure and increased incidence of hypertension. The association was weaker among African-American women compared to other ethnicity-gender groups.


Asunto(s)
Hipertensión/epidemiología , Obesidad/complicaciones , Aumento de Peso , Población Negra/genética , Presión Sanguínea , Estudios de Cohortes , Femenino , Humanos , Hipertensión/etnología , Hipertensión/etiología , Hipertensión/genética , Incidencia , Estudios Longitudinales , Masculino , Maryland/epidemiología , Persona de Mediana Edad , Minnesota/epidemiología , Mississippi/epidemiología , North Carolina/epidemiología , Modelos de Riesgos Proporcionales , Población Blanca/genética
15.
J Photochem Photobiol B ; 65(1): 74-84, 2001 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-11748007

RESUMEN

Kinetics and mechanism of the oxidation of tyrosine (Tyr) and valine (Val) di- and tripeptides (Tyr-Val, Val-Tyr and Val-Tyr-Val) mediated by singlet molecular oxygen [O(2)((1)Delta(g))], phosphate (HPO(4)(*-) and PO(4)(*2-)) and sulfate (SO(4)(*-)) radicals was studied, employing time-resolved O(2)((1)Delta(g)) phosphorescence detection, polarographic determination of dissolved oxygen and flash photolysis. All the substrates were highly photooxidizable through a O(2)((1)Delta(g))-mediated mechanism. Calculated quotients between the overall and reactive rate constants for the quenching of O(2)((1)Delta(g)) by Tyr-derivatives (k(t)/k(r) values, accounting for the efficiency of the effective photooxidation) were 1.3 for Tyr, 1 for Tyr-Val, 2.8 for Val-Tyr and 1.5 for Val-Tyr-Val. The effect of pH on the kinetics of the photooxidative process confirms that the presence of the dissociated phenolate group of Tyr clearly dominates the O(2)((1)Delta(g)) quenching process. Products analysis by LC-MS indicates that the photooxidation of Tyr di- and tripeptides proceeds with the breakage of peptide bonds. The information obtained from the evolution of primary amino groups upon photosensitized irradiation is in concordance with these results. Absolute rate constants for the reactions of phosphate radicals (HPO(4)(*-) and PO(4)(*2-), generated by photolysis of the P(2)O(8)(4-) at different pH) and sulfate radicals (SO(4)(*-), produced by photolysis of the S(2)O(8)(2-)) with Tyr peptides indicate that for all the substrates, the observed tendency in the rate constants is: SO(4)(*-) > or = HPO(4)(*-) > or = PO(4)(*2-). Formation of the phenoxyl radical of tyrosine was detected as an intermediate involved in the oxidation of tyrosine by HPO(4)(*-).


Asunto(s)
Dipéptidos/química , Radicales Libres/química , Fosfatos/química , Oxígeno Singlete/química , Sulfatos/química , Tirosina/química , Valina/química , Aminas/química , Oxidación-Reducción
16.
Obes Res ; 9(11): 696-705, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11707536

RESUMEN

OBJECTIVE: To evaluate the ability of body mass index, waist circumference, waist-to-hip ratio, and combinations of these variables to discriminate individuals who will develop diabetes in adulthood. RESEARCH METHODS AND PROCEDURES: Data were from 45- to 64-year-old men and women who were members of the Atherosclerosis Risk in Communities cohort. The analysis sample consisted of 12,814 African American and white participants who were free of diabetes at baseline. Body mass index, waist circumference, waist-to-hip ratio, and diabetes incidence (defined as one glucose measure > or =126 mg/dL after fasting for at least 8 hours, one nonfasting glucose measure > or =200 mg/dL, and self-report of diabetes or report of taking medication for diabetes). RESULTS: 1515 new cases of diabetes were identified over the 9-year follow-up. Areas under receiver operating characteristic curves ranged from 0.66 to 0.73 for single measures. The curves were smooth, with no indication of a threshold. Waist tended to have the highest receiver operating characteristic statistic in all groups, but differences were small. DISCUSSION: The three anthropometric indices tested were approximately equivalent in their ability to predict diabetes. Sensitivity and specificities differed among ethnic and gender groups.


Asunto(s)
Antropometría , Diabetes Mellitus/epidemiología , Grupos Raciales , Población Negra , Constitución Corporal , Índice de Masa Corporal , Peso Corporal , Femenino , Humanos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Factores de Riesgo , Sensibilidad y Especificidad , Factores Sexuales , Población Blanca
17.
Am J Epidemiol ; 154(8): 758-64, 2001 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-11590089

RESUMEN

The authors examined the association between white blood cell (WBC) count and incidence of coronary heart disease and ischemic stroke and mortality from cardiovascular disease in 13,555 African-American and White men and women from the Atherosclerosis Risk in Communities (ARIC) Study. Blood was drawn at the ARIC baseline examination, beginning in 1987-1989. During an average of 8 years of follow-up (through December 1996), there were 488 incident coronary heart disease events, 220 incident strokes, and 258 deaths from cardiovascular disease. After adjustment for age, sex, ARIC field center, and multiple risk factors, there was a direct association between WBC count and incidence of coronary heart disease (p < 0.001 for trend) and stroke (p for trend < 0.001) and mortality from cardiovascular disease (p for trend < 0.001) in African Americans. The African Americans in the highest quartile of WBC count (> or =7,000 cells/mm(3)) had 1.9 times the risk of incident coronary heart disease (95% confidence interval (CI): 1.19, 3.09), 1.9 times the risk of incident ischemic stroke (95% CI: 1.03, 3.34), and 2.3 times the risk of cardiovascular disease mortality (95% CI: 1.38, 3.72) as their counterparts in the lowest quartile of WBC count (<4,800 cells/mm(3)). These associations were similar in Whites and in never smokers. An elevated WBC count is directly associated with increased incidence of coronary heart disease and ischemic stroke and mortality from cardiovascular disease in African-American and White men and women.


Asunto(s)
Población Negra , Enfermedades Cardiovasculares/mortalidad , Enfermedad Coronaria/epidemiología , Recuento de Leucocitos , Accidente Cerebrovascular/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Población Blanca
18.
Am J Epidemiol ; 154(6): 489-94, 2001 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-11549553

RESUMEN

Many studies have investigated the role of estrogen during menopause; however, less attention has been paid to the role of androgen. Given the possible opposite effects of estrogen and androgen on cardiovascular disease risk, it is suggested that relative androgen excess may better predict the increased risk of cardiovascular disease in women over the age of 50 years than estrogen levels alone. Three phases of hormonal milieu changes are hypothesized as a better way to identify the hormone-cardiovascular disease risk association. A first phase, prepause, occurs before estrogen levels decline (approximately 2 years before menopause). A second phase, interpause, occurs from the end of prepause until approximately age 55. A third phase, postpause, occurs after interpause. The duration of the interpause phase, characterized by relative androgen excess, may be an independent risk factor of cardiovascular disease. This hypothesis could provide a basis for further clinical and epidemiologic research, and it could have important implications for establishing the initiation and duration of estrogen replacement therapy use as a means to prevent cardiovascular disease.


Asunto(s)
Andrógenos/efectos adversos , Enfermedades Cardiovasculares/etiología , Posmenopausia , Anciano , Estrógenos/sangre , Femenino , Terapia de Reemplazo de Hormonas , Humanos , Persona de Mediana Edad , Factores de Riesgo
19.
Am J Epidemiol ; 154(3): 230-5, 2001 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-11479187

RESUMEN

The objective of the study was to determine which component of an anger-prone personality more strongly predicts coronary heart disease (CHD) risk. Proneness to anger, as assessed by the Spielberger Trait Anger Scale, is composed of two distinct subcomponents-anger-temperament and anger-reaction. Participants were 12,990 middle-aged Black men and women and White men and women from the Atherosclerosis Risk in Communities Study who were followed for the occurrence of acute myocardial infarction (MI)/fatal CHD, silent MI, or cardiac revascularization procedures (average = 53 months; maximum = 72 months) through December 31, 1995. Among normotensive persons, a strong, angry temperament (tendency toward quick, minimally provoked, or unprovoked anger) was associated with combined CHD (acute MI/fatal CHD, silent MI, or cardiac revascularization procedures) (multivariate-adjusted hazard ratio = 2.10, 95% confidence interval: 1.34, 3.29) and with 'hard" events (acute MI/fatal CHD) (multivariate adjusted hazard ratio = 2.28, 95% confidence interval: 1.29, 4.02). CHD event-free survival among normotensives who had a strong, angry temperament was not significantly different from that of hypertensives at either level of anger. These data suggest that a strong, angry temperament rather than anger in reaction to criticism, frustration, or unfair treatment places normotensive, middle-aged persons at increased risk for cardiac events and may confer a CHD risk similar to that of hypertension.


Asunto(s)
Ira , Arteriosclerosis/epidemiología , Enfermedad Coronaria/epidemiología , Temperamento , Población Negra , Comorbilidad , Femenino , Humanos , Hipertensión/epidemiología , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Medición de Riesgo , Factores de Riesgo , Análisis de Supervivencia , Tasa de Supervivencia , Estados Unidos/epidemiología , Población Blanca
20.
Surv Ophthalmol ; 46(1): 59-80, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11525792

RESUMEN

Retinal microvascular abnormalities, such as generalized and focal arteriolar narrowing, arteriovenous nicking and retinopathy, reflect cumulative vascular damage from hypertension, aging, and other processes. Epidemiological studies indicate that these abnormalities can be observed in 2-15% of the nondiabetic general population and are strongly and consistently associated with elevated blood pressure. Generalized arteriolar narrowing and arteriovenous nicking also appear to be irreversible long-term markers of hypertension, related not only to current but past blood pressure levels as well. There are data supporting an association between retinal microvascular abnormalities and stroke, but there is no convincing evidence of an independent or direct association with atherosclerosis, ischemic heart disease, or cardiovascular mortality. New computer-related imaging methods are currently being developed to detect the presence and severity of retinal arteriolar narrowing and other microvascular characteristics. When reliably quantified, retinal microvascular abnormalities may be useful as risk indicators for cerebrovascular diseases.


Asunto(s)
Enfermedades Cardiovasculares/mortalidad , Hipertensión/mortalidad , Enfermedades de la Retina/complicaciones , Vasos Retinianos/patología , Enfermedades Cardiovasculares/etiología , Humanos , Hipertensión/etiología
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