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1.
ACS Cent Sci ; 9(12): 2339-2349, 2023 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-38161376

RESUMEN

Antibiotic-resistant Enterobacterales that produce oxacillinase (OXA)-48-like Class D ß-lactamases are often linked to increased clinical mortality. Though the catalytic mechanism of OXA-48 is known, the molecular origin of its biphasic kinetics has been elusive. We here identify selective chloride binding rather than decarbamylation of the carbamylated lysine as the source of biphasic kinetics, utilizing isothermal titration calorimetry (ITC) to monitor the complete reaction course with the OXA-48 variant having a chemically stable N-acetyl lysine. Further structural investigation enables us to capture an unprecedented inactive acyl intermediate wedged in place by a halide ion paired with a conserved active site arginine. Supported by mutagenesis and mathematical simulation, we identify chloride as a "Janus effector" that operates by allosteric activation of the burst phase and by inhibition of the steady state in kinetic assays of ß-lactams. We show that chloride-induced biphasic kinetics directly affects antibiotic efficacy and facilitates the differentiation of clinical isolates encoding Class D from Class A and B carbapenemases. As chloride is present in laboratory and clinical procedures, our discovery greatly expands the roles of chloride in modulating enzyme catalysis and highlights its potential impact on the pharmacokinetics and efficacy of antibiotics during in vivo treatment.

2.
Remote Sens Ecol Conserv ; 9(4): 483-500, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38505567

RESUMEN

Birds are useful indicators of overall biodiversity, which continues to decline globally, despite targets to reduce its loss. The aim of this paper is to understand the importance of different spatial drivers for modelling bird distributions. Specifically, it assesses the importance of satellite-derived measures of habitat productivity, heterogeneity and landscape structure for modelling bird diversity across Great Britain. Random forest (RF) regression is used to assess the extent to which a combination of satellite-derived covariates explain woodland and farmland bird diversity and richness. Feature contribution analysis is then applied to assess the relationships between the response variable and the covariates in the final RF models. We show that much of the variation in farmland and woodland bird distributions is explained (R 2 0.64-0.77) using monthly habitat-specific productivity values and landscape structure (FRAGSTATS) metrics. The analysis highlights important spatial drivers of bird species richness and diversity, including high productivity grassland during spring for farmland birds and woodland patch edge length for woodland birds. The feature contribution provides insight into the form of the relationship between the spatial drivers and bird richness and diversity, including when a particular spatial driver affects bird richness positively or negatively. For example, for woodland bird diversity, the May 80th percentile Normalized Difference Vegetation Index (NDVI) for broadleaved woodland has a strong positive effect on bird richness when NDVI is >0.7 and a strong negative effect below. If relationships such as these are stable over time, they offer a useful analytical tool for understanding and comparing the influence of different spatial drivers.

3.
Obesity (Silver Spring) ; 28(9): 1678-1686, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32841523

RESUMEN

OBJECTIVE: This study was designed to determine whether intensive lifestyle intervention (ILI) aimed at weight loss lowers cancer incidence and mortality. METHODS: Data from the Look AHEAD trial were examined to investigate whether participants randomized to ILI designed for weight loss would have reduced overall cancer incidence, obesity-related cancer incidence, and cancer mortality, as compared with the diabetes support and education (DSE) comparison group. This analysis included 4,859 participants without a cancer diagnosis at baseline except for nonmelanoma skin cancer. RESULTS: After a median follow-up of 11 years, 684 participants (332 in ILI and 352 in DSE) were diagnosed with cancer. The incidence rates of obesity-related cancers were 6.1 and 7.3 per 1,000 person-years in ILI and DSE, respectively, with a hazard ratio (HR) of 0.84 (95% CI: 0.68-1.04). There was no significant difference between the two groups in total cancer incidence (HR, 0.93; 95% CI: 0.80-1.08), incidence of nonobesity-related cancers (HR, 1.02; 95% CI: 0.83-1.27), or total cancer mortality (HR, 0.92; 95% CI: 0.68-1.25). CONCLUSIONS: An ILI aimed at weight loss lowered incidence of obesity-related cancers by 16% in adults with overweight or obesity and type 2 diabetes. The study sample size likely lacked power to determine effect sizes of this magnitude and smaller.


Asunto(s)
Diabetes Mellitus Tipo 2/complicaciones , Neoplasias/etiología , Obesidad/terapia , Pérdida de Peso/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad
4.
Obesity (Silver Spring) ; 28(5): 893-901, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32320144

RESUMEN

OBJECTIVE: This study evaluated weight changes after cessation of the 10-year intensive lifestyle intervention (ILI) in the Look AHEAD (Action for Health in Diabetes) study. It was hypothesized that ILI participants would be more likely to gain weight during the 2-year observational period following termination of weight-loss-maintenance counseling than would participants in the diabetes support and education (DSE) control group. METHODS: Look AHEAD was a randomized controlled trial that compared the effects of ILI and DSE on cardiovascular morbidity and mortality in participants with overweight/obesity and type 2 diabetes. Look AHEAD was converted to an observational study in September 2012. RESULTS: Two years after the end of the intervention (EOI), ILI and DSE participants lost a mean (SE) of 1.2 (0.2) kg and 1.8 (0.2) kg, respectively (P = 0.003). In addition, 31% of ILI and 23.9% of DSE participants gained ≥ 2% (P < 0.001) of EOI weight, whereas 36.3% and 45.9% of the respective groups lost ≥ 2% of EOI weight (P = 0.001). Two years after the EOI, ILI participants reported greater use of weight-control behaviors than DSE participants. CONCLUSIONS: Both groups lost weight during the 2-year follow-up period, but more ILI than DSE participants gained ≥ 2% of EOI weight. Further understanding is needed of factors that affected long-term weight change in both groups.


Asunto(s)
Estilo de Vida , Obesidad/terapia , Pérdida de Peso/fisiología , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad
5.
Obesity (Silver Spring) ; 28(2): 247-258, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31898874

RESUMEN

OBJECTIVE: To examine the effects of an intensive lifestyle intervention (ILI) on cardiovascular disease (CVD), the Action for Health in Diabetes (Look AHEAD) trial randomized 5,145 participants with type 2 diabetes and overweight/obesity to a ILI or diabetes support and education. Although the primary outcome did not differ between the groups, there was suggestive evidence of heterogeneity for prespecified baseline CVD history subgroups (interaction P = 0.063). Event rates were higher in the ILI group among those with a CVD history (hazard ratio 1.13 [95% CI: 0.90-1.41]) and lower among those without CVD (hazard ratio 0.86 [95% CI: 0.72-1.02]). METHODS: This study conducted post hoc analyses of the rates of the primary composite outcome and components, adjudicated cardiovascular death, nonfatal myocardial infarction (MI), stroke, and hospitalization for angina, as well as three secondary composite cardiovascular outcomes. RESULTS: Interaction P values for the primary and two secondary composites were similar (0.060-0.064). Of components, the interaction was significant for nonfatal MI (P = 0.035). This interaction was not due to confounding by baseline variables, different intervention responses for weight loss and physical fitness, or hypoglycemic events. In those with a CVD history, statin use was high and similar by group. In those without a CVD history, low-density lipoprotein cholesterol levels were higher (P = 0.003) and statin use was lower (P ≤ 0.001) in the ILI group. CONCLUSIONS: Intervention response heterogeneity was significant for nonfatal MI. Response heterogeneity may need consideration in a CVD-outcome trial design.


Asunto(s)
Enfermedades Cardiovasculares/epidemiología , Estilo de Vida , Femenino , Humanos , Masculino , Persona de Mediana Edad
6.
BMC Obes ; 5: 27, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30410772

RESUMEN

BACKGROUND: Bariatric surgery is currently the most effective strategy for producing significant and durable weight loss. Yet, not all patients achieve initial weight loss success and some degree of weight regain is very common, sometimes as early as 1-2 years post-surgery. Suboptimal weight loss not fully explained by surgical, demographic, and medical factors has led to greater emphasis on patient behaviors evidenced by clinical guidelines for appropriate eating and physical activity. However, research to inform such guidelines has often relied on imprecise measures or not been specific to bariatric surgery. There is also little understanding of what psychosocial factors and environmental contexts impact outcomes. To address research gaps and measurement limitations, we designed a protocol that innovatively integrates multiple measurement tools to determine which behaviors, environmental contexts, and psychosocial factors are related to outcomes and explore how psychosocial factors/environmental contexts influence weight. This paper provides a detailed description of our study protocol with a focus on developing and deploying a multi-sensor assessment tool to meet our study aims. METHODS: This NIH-funded prospective cohort study evaluates behavioral, psychosocial, and environmental predictors of weight loss after bariatric surgery using a multi-sensor platform that integrates objective sensors and self-report information collected via smartphone in real-time in patients' natural environment. A target sample of 100 adult, bariatric surgery patients (ages 21-70) use this multi-sensor platform at preoperative baseline, as well as 3, 6, and 12 months postoperatively, to assess recommended behaviors (e.g., meal frequency, physical activity), psychosocial indicators with prior evidence of an association with surgical outcomes (e.g., mood/depression), and key environmental factors (e.g., type/quality of food environment). Weight also is measured at each assessment point. DISCUSSION: This project has the potential to build a more sophisticated and valid understanding of behavioral and psychosocial factors contributing to success and risk after bariatric surgery. This new understanding could directly contribute to improved (i.e., specific, consistent, and validated) guidelines for recommended pre- and postoperative behaviors, which could lead to improved surgical outcomes. These data will also inform behavioral, psychosocial, and environmental targets for adjunctive interventions to improve surgical outcomes. TRIAL REGISTRATION: Registered trial NCT02777177 on 5/19/2016.

7.
Sci Rep ; 7(1): 6429, 2017 07 25.
Artículo en Inglés | MEDLINE | ID: mdl-28743986

RESUMEN

The PROSPECT leaf optical model has, to date, well-separated the effects of total chlorophyll and carotenoids on leaf reflectance and transmittance in the 400-800 nm. Considering variations in chlorophyll a:b ratio with leaf age and physiological stress, a further separation of total plant-based chlorophylls into chlorophyll a and chlorophyll b is necessary for advanced monitoring of plant growth. In this study, we present an extended version of PROSPECT model (hereafter referred to as PROSPECT-MP) that can combine the effects of chlorophyll a, chlorophyll b and carotenoids on leaf directional hemispherical reflectance and transmittance (DHR and DHT) in the 400-800 nm. The LOPEX93 dataset was used to evaluate the capabilities of PROSPECT-MP for spectra modelling and pigment retrieval. The results show that PROSPECT-MP can both simultaneously retrieve leaf chlorophyll a and b, and also performs better than PROSPECT-5 in retrieving carotenoids concentrations. As for the simulation of DHR and DHT, the performances of PROSPECT-MP are similar to that of PROSPECT-5. This study demonstrates the potential of PROSPECT-MP for improving capabilities of remote sensing of leaf photosynthetic pigments (chlorophyll a, chlorophyll b and carotenoids) and for providing a framework for future refinements in the modelling of leaf optical properties.


Asunto(s)
Clorofila A/química , Clorofila/química , Modelos Biológicos , Hojas de la Planta/química , Tecnología de Sensores Remotos/métodos , Algoritmos , Calibración , Carotenoides/análisis , Carotenoides/química , Clorofila/análisis , Clorofila A/análisis , Hojas de la Planta/fisiología
8.
Obes Surg ; 27(11): 2873-2884, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28500418

RESUMEN

BACKGROUND: Prior studies have suggested less weight loss among African American compared to Caucasian patients; however, few studies have been able to simultaneously account for baseline differences in other demographic, clinical, or behavioral factors. METHODS: We interviewed patients at two weight loss surgery (WLS) centers and conducted chart reviews before and after WLS. We compared weight loss post-WLS by race/ethnicity and examined baseline demographic, clinical (BMI, comorbidities, quality of life), and behavioral (eating behavior, physical activity level, alcohol intake) factors that might explain observed racial differences in weight loss at 1 and 2 years after WLS. RESULTS: Of 537 participants who underwent either Roux-en-Y Gastric Bypass (54%) or gastric banding (46%), 85% completed 1-year follow-up and 73% completed 2-year follow-up. Patients lost a mean of 33.00% of initial weight at year 1 and 32.43% at year 2 after bypass and 16.07% and 17.56 % respectively after banding. After adjustment for other demographic characteristics and type of surgery, African Americans lost an absolute 5.93 ± 1.49% less weight than Caucasian patients after bypass (p < 0.001) and 4.72 ± 1.96% less weight after banding. Of the other demographic, clinical, behavioral factors considered, having diabetes and perceived difficulty making dietary changes at baseline were associated with less weight loss among gastric bypass patients whereas having a diagnosis of anxiety disorder was associated with less weight loss among gastric banding patients. The association between race and weight loss did not substantially attenuate with additional adjustment for these clinical and behavioral factors, however. CONCLUSION: African American patients lost significantly less weight than Caucasian patients. Racial differences could not be explained by baseline demographic, clinical, or behavioral characteristics we examined.


Asunto(s)
Cirugía Bariátrica , Conducta Alimentaria , Obesidad Mórbida/epidemiología , Obesidad Mórbida/cirugía , Grupos Raciales , Pérdida de Peso , Adulto , Negro o Afroamericano/estadística & datos numéricos , Cirugía Bariátrica/rehabilitación , Cirugía Bariátrica/estadística & datos numéricos , Comorbilidad , Conducta Alimentaria/etnología , Conducta Alimentaria/fisiología , Femenino , Humanos , Laparoscopía/rehabilitación , Laparoscopía/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Obesidad Mórbida/etnología , Calidad de Vida , Grupos Raciales/estadística & datos numéricos , Estudios Retrospectivos , Factores Socioeconómicos , Pérdida de Peso/etnología , Población Blanca/estadística & datos numéricos
9.
Neurology ; 88(21): 2026-2035, 2017 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-28446656

RESUMEN

OBJECTIVE: To assess whether an average of 10 years of lifestyle intervention designed to reduce weight and increase physical activity lowers the prevalence of cognitive impairment among adults at increased risk due to type 2 diabetes and obesity or overweight. METHODS: Central adjudication of mild cognitive impairment and probable dementia was based on standardized cognitive test battery scores administered to 3,802 individuals who had been randomly assigned, with equal probability, to either the lifestyle intervention or the diabetes support and education control. When scores fell below a prespecified threshold, functional information was obtained through proxy interview. RESULTS: Compared with control, the intensive lifestyle intervention induced and maintained marked differences in weight loss and self-reported physical activity throughout follow-up. At an average (range) of 11.4 (9.5-13.5) years after enrollment, when participants' mean age was 69.6 (54.9-87.2) years, the prevalence of mild cognitive impairment and probable dementia was 6.4% and 1.8%, respectively, in the intervention group, compared with 6.6% and 1.8%, respectively, in the control group (p = 0.93). The lack of an intervention effect on the prevalence of cognitive impairment was consistent among individuals grouped by cardiovascular disease history, diabetes duration, sex, and APOE ε4 allele status (all p ≥ 0.50). However, there was evidence (p = 0.03) that the intervention effect ranged from benefit to harm across participants ordered from lowest to highest baseline BMI. CONCLUSIONS: Ten years of behavioral weight loss intervention did not result in an overall difference in the prevalence of cognitive impairment among overweight or obese adults with type 2 diabetes. CLINICALTRIALSGOV IDENTIFIER: NCT00017953 (Action for Health in Diabetes). LEVEL OF EVIDENCE: This study provides Class II evidence that for overweight adults with type 2 diabetes, a lifestyle intervention designed to reduce weight and increase physical activity does not lower the risk of cognitive impairment.


Asunto(s)
Disfunción Cognitiva/epidemiología , Ejercicio Físico , Estilo de Vida Saludable , Sobrepeso/epidemiología , Sobrepeso/terapia , Programas de Reducción de Peso , Anciano , Anciano de 80 o más Años , Índice de Masa Corporal , Disfunción Cognitiva/complicaciones , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/psicología , Diabetes Mellitus Tipo 2/terapia , Ejercicio Físico/psicología , Femenino , Estudios de Seguimiento , Humanos , Entrevistas como Asunto , Masculino , Escala del Estado Mental , Persona de Mediana Edad , Sobrepeso/psicología , Educación del Paciente como Asunto , Prevalencia , Autoinforme , Apoyo Social , Factores de Tiempo
10.
PLoS One ; 12(1): e0169786, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28072883

RESUMEN

Birds are a frequently chosen group for biodiversity monitoring as they are comparatively straightforward and inexpensive to sample and often perform well as ecological indicators. Two commonly used techniques for monitoring tropical forest bird communities are point counts and mist nets. General strengths and weaknesses of these techniques have been well-defined; however little research has examined how their effectiveness is mediated by the ecology of bird communities and their habitats. We examine how the overall performance of these methodologies differs between two widely separated tropical forests-Cusuco National Park (CNP), a Honduran cloud forest, and the lowland forests of Buton Forest Reserves (BFR) located on Buton Island, Indonesia. Consistent survey protocols were employed at both sites, with 77 point count stations and 22 mist netting stations being surveyed in each location. We found the effectiveness of both methods varied considerably between ecosystems. Point counts performed better in BFR than in CNP, detecting a greater percentage of known community richness (60% versus 41%) and generating more accurate species richness estimates. Conversely, mist netting performed better in CNP than in BFR, detecting a much higher percentage of known community richness (31% versus 7%). Indeed, mist netting proved overall to be highly ineffective within BFR. Best Akaike's Information Criterion models indicate differences in the effectiveness of methodologies between study sites relate to bird community composition, which in turn relates to ecological and biogeographical influences unique to each forest ecosystem. Results therefore suggest that, while generalized strengths and weaknesses of both methodologies can be defined, their overall effectiveness is also influenced by local characteristics specific to individual study sites. While this study focusses on ornithological surveys, the concept of local factors influencing effectiveness of field methodologies may also hold true for techniques targeting a wide range of taxonomic groups; this requires further research.


Asunto(s)
Biodiversidad , Aves/clasificación , Seguimiento de Parámetros Ecológicos/métodos , Ecología/métodos , Bosques , Animales , Aves/fisiología , Seguimiento de Parámetros Ecológicos/normas , Ecología/normas , Clima Tropical
11.
J Am Geriatr Soc ; 65(5): 966-972, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28067945

RESUMEN

OBJECTIVES: To assess whether randomization to 10 years of lifestyle intervention to induce and maintain weight loss improves cognitive function. DESIGN: Randomized controlled clinical trial. SETTING: Data obtained as part of the Action for Health in Diabetes (Look AHEAD) trial (NCT00017953) and Look AHEAD Continuation study (U01 DK057136-15). PARTICIPANTS: Overweight and obese individuals with type 2 diabetes mellitus aged 45 to 76 (N = 3,751). INTERVENTION: Intensive lifestyle intervention (ILI) for weight loss through reduced caloric intake and increased physical activity compared with a control condition of diabetes support and education (DSE). MEASUREMENTS: Certified examiners who were masked to intervention assignment administered a standard battery of cognitive function tests (Modified Mini-Mental State Examination, Rey Auditory Verbal Learning Test, Digit Symbol Coding, Trail-Making Test, Modified Stroop Color-Word Test) to participants 10 to 13 years after enrollment. RESULTS: Assignment to lifestyle intervention was not associated with significantly different overall (P = .10) or domain-specific (all P > .10) cognitive function than assignment to diabetes support and education. Results were fairly consistent across prespecified groups, but there was some evidence of trends for differential intervention effects showing modest harm in ILI in participants with greater body mass index and in individuals with a history of cardiovascular disease. Cognitive function was not associated with changes in weight or fitness (all P > .05). CONCLUSION: A long-term behavioral weight loss intervention for overweight and obese adults with diabetes mellitus was not associated with cognitive benefit. Trial Registration clinicaltrials.gov Identifier: NCT00017953.


Asunto(s)
Terapia Conductista/métodos , Cognición , Diabetes Mellitus Tipo 2/rehabilitación , Estilo de Vida , Anciano , Diabetes Mellitus Tipo 2/complicaciones , Ejercicio Físico , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Obesidad/rehabilitación , Educación del Paciente como Asunto/métodos , Escalas de Valoración Psiquiátrica/estadística & datos numéricos , Resultado del Tratamiento , Pérdida de Peso/fisiología
12.
J Am Geriatr Soc ; 65(1): 137-145, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27676466

RESUMEN

OBJECTIVES: To test whether average long-term glucose exposure is associated with cognitive and physical function in middle-aged and younger-old adults with type 2 diabetes mellitus. DESIGN: Prospective cohort study. SETTING: Data obtained as part of the Action for Health in Diabetes (Look AHEAD) trial (NCT00017953) and Look AHEAD Movement and Memory ancillary study (NCT01410097). PARTICIPANTS: Overweight and obese individuals with type 2 diabetes mellitus aged 45 to 76 at baseline (N = 879). MEASUREMENTS: Glycosylated hemoglobin (HbA1c) was measured at regular intervals over 7 years, and objective measures of cognitive function (Trail-Making Test, Modified Stroop Color-Word Test, Digit Symbol-Coding, Rey Auditory Verbal Learning Test, Modified Mini-Mental State Examination) and physical function (Short Physical Performance Battery, expanded Physical Performance Battery, 400-m and 20-m gait speed) and strength (grip and knee extensor strength) were assessed at the Year 8 or 9 follow-up examination. RESULTS: Average HbA1c exposure was 7.0 ± 1.1% (53 ± 11.6 mmol/mol), with 57% of participants classified as having HbA1c levels of less than 7% (<53 mmol/mol), 27% having levels of 7% to 8% (53-64 mmol/mol), and 16% having levels of greater than 8% (>64 mmol/mol). After adjustment for age, sex, race, education, smoking status, alcohol intake, knee pain, physical fitness, body mass index, diabetes mellitus medication and statin use, ancillary year visit, and study arm and site, higher HbA1c was associated with worse physical but not cognitive function. Further adjustment for prevalent diabetes mellitus-related comorbidities made all associations nonsignificant. Results did not differ when stratified according to participant baseline age (<60 vs ≥ 60). CONCLUSION: Results presented here suggest that, in the absence of diabetes mellitus-related complications, longitudinal glucose exposure is not associated with future cognitive and physical function. Optimal management of diabetes mellitus-related comorbidities may prevent or reduce the burden of disability associated with type 2 diabetes mellitus.


Asunto(s)
Cognición , Diabetes Mellitus Tipo 2/sangre , Hemoglobina Glucada/análisis , Factores de Edad , Anciano , Estudios de Cohortes , Prueba de Esfuerzo , Femenino , Estado de Salud , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Obesidad/epidemiología , Sobrepeso/epidemiología , Estados Unidos/epidemiología
13.
Lancet Diabetes Endocrinol ; 4(11): 913-921, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27595918

RESUMEN

BACKGROUND: Findings from the Look AHEAD trial showed no significant reductions in the primary outcome of cardiovascular disease incidence in adults with type 2 diabetes randomly assigned to an intensive lifestyle intervention for weight loss compared with those randomly assigned to diabetes support and education (control). We examined whether the incidence of cardiovascular disease in Look AHEAD varied by changes in weight or fitness. METHODS: Look AHEAD was a randomised clinical trial done at 16 clinical sites in the USA, recruiting patients from Aug 22, 2001, to April 30, 2004. In the trial, 5145 overweight or obese adults aged 45-76 years with type 2 diabetes were assigned (1:1) to an intensive lifestyle intervention or diabetes support and education. In this observational, post-hoc analysis, we examined the association of magnitude of weight loss and fitness change over the first year with incidence of cardiovascular disease. The primary outcome of the trial and of this analysis was a composite of death from cardiovascular causes, non-fatal acute myocardial infarction, non-fatal stroke, or admission to hospital for angina. The secondary outcome included the same indices plus coronary artery bypass grafting, carotid endartectomy, percutaneous coronary intervention, hospitalisation for congestive heart failure, peripheral vascular disease, or total mortality. We adjusted analyses for baseline differences in weight or fitness, demographic characteristics, and risk factors for cardiovascular disease. The Look AHEAD trial is registered with ClinicalTrials.gov, number NCT00017953. FINDINGS: For the analyses related to weight change, we excluded 311 ineligible participants, leaving a population of 4834; for the analyses related to fitness change, we excluded 739 participants, leaving a population of 4406. In analyses of the full cohort (ie, combining both study groups), over a median 10·2 years of follow-up (IQR 9·5-10·7), individuals who lost at least 10% of their bodyweight in the first year of the study had a 21% lower risk of the primary outcome (adjusted hazard ratio [HR] 0·79, 95% CI 0·64-0·98; p=0·034) and a 24% reduced risk of the secondary outcome (adjusted HR 0·76, 95% CI 0·63-0·91; p=0·003) compared with individuals with stable weight or weight gain. Achieving an increase of at least 2 metabolic equivalents in fitness change was associated with a significant reduction in the secondary outcome (adjusted HR 0·77, 95% CI 0·61-0·96; p=0·023) but not the primary outcome (adjusted HR 0·78, 0·60-1·03; p=0·079). In analyses treating the control group as the reference group, participants in the intensive lifestyle intervention group who lost at least 10% of their bodyweight had a 20% lower risk of the primary outcome (adjusted HR 0·80, 95% CI 0·65-0·99; p=0·039), and a 21% lower risk of the secondary outcome (adjusted HR 0·79, 95% CI 0·66-0·95; p=0·011); however, change in fitness was not significantly associated with a change in the primary outcome. INTERPRETATION: The results of this post-hoc analysis of Look AHEAD suggest an association between the magnitude of weight loss and incidence of cardiovascular disease in people with type 2 diabetes. These findings suggest a need to continue to refine approaches to identify individuals who are most likely to benefit from lifestyle interventions and to develop strategies to improve the magnitude of sustained weight loss with lifestyle interventions. FUNDING: US National Institute of Diabetes and Digestive and Kidney Diseases.


Asunto(s)
Enfermedades Cardiovasculares/prevención & control , Diabetes Mellitus Tipo 2/complicaciones , Obesidad/complicaciones , Aptitud Física , Pérdida de Peso , Anciano , Enfermedades Cardiovasculares/etiología , Estudios de Cohortes , Manejo de la Enfermedad , Femenino , Educación en Salud , Humanos , Estilo de Vida , Masculino , Persona de Mediana Edad
14.
Nutrients ; 8(5)2016 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-27187450

RESUMEN

Mothers' own milk is the best source of nutrition for nearly all infants. Beyond somatic growth, breast milk as a biologic fluid has a variety of other benefits, including modulation of postnatal intestinal function, immune ontogeny, and brain development. Although breastfeeding is highly recommended, breastfeeding may not always be possible, suitable or solely adequate. Infant formula is an industrially produced substitute for infant consumption. Infant formula attempts to mimic the nutritional composition of breast milk as closely as possible, and is based on cow's milk or soymilk. A number of alternatives to cow's milk-based formula also exist. In this article, we review the nutritional information of breast milk and infant formulas for better understanding of the importance of breastfeeding and the uses of infant formula from birth to 12 months of age when a substitute form of nutrition is required.


Asunto(s)
Fórmulas Infantiles/química , Leche Humana/química , Adulto , Lactancia Materna , Femenino , Humanos , Lactante , Fenómenos Fisiológicos Nutricionales del Lactante , Recién Nacido
15.
Am J Clin Nutr ; 103(5): 1197-203, 2016 05.
Artículo en Inglés | MEDLINE | ID: mdl-27030535

RESUMEN

BACKGROUND: Ideal body weight (IBW) equations and body mass index (BMI) ranges have both been used to delineate healthy or normal weight ranges, although these 2 different approaches are at odds with each other. In particular, past IBW equations are misaligned with BMI values, and unlike BMI, the equations have failed to recognize that there is a range of ideal or target body weights. OBJECTIVE: For the first time, to our knowledge, we merged the concepts of a linear IBW equation and of defining target body weights in terms of BMI. DESIGN: With the use of calculus and approximations, we derived an easy-to-use linear equation that clinicians can use to calculate both IBW and body weight at any target BMI value. We measured the empirical accuracy of the equation with the use of NHANES data and performed a comparative analysis with past IBW equations. RESULTS: Our linear equation allowed us to calculate body weights for any BMI and height with a mean empirical accuracy of 0.5-0.7% on the basis of NHANES data. Moreover, we showed that our body weight equation directly aligns with BMI values for both men and women, which avoids the overestimation and underestimation problems at the upper and lower ends of the height spectrum that have plagued past IBW equations. CONCLUSIONS: Our linear equation increases the sophistication of IBW equations by replacing them with a single universal equation that calculates both IBW and body weight at any target BMI and height. Therefore, our equation is compatible with BMI and can be applied with the use of mental math or a calculator without the need for an app, which makes it a useful tool for both health practitioners and the general public.


Asunto(s)
Índice de Masa Corporal , Peso Corporal , Peso Corporal Ideal , Modelos Teóricos , Adulto , Estatura , Femenino , Humanos , Masculino , Encuestas Nutricionales
16.
PLoS One ; 11(2): e0149292, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26886207

RESUMEN

Tropical forests are experiencing a growing fire problem driven by climatic change, agricultural expansion and forest degradation. Protected areas are an important feature of forest protection strategies, and sustainable use reserves (SURs) may be reducing fire prevalence since they promote sustainable livelihoods and resource management. However, the use of fire in swidden agriculture, and other forms of land management, may be undermining the effectiveness of SURs in meeting their conservation and sustainable development goals. We analyse MODIS derived hot pixels, TRMM rainfall data, Terra-Class land cover data, socio-ecological data from the Brazilian agro-census and the spatial extent of rivers and roads to evaluate whether the designation of SURs reduces fire occurrence in the Brazilian Amazon. Specifically, we ask (1) a. Is SUR location (i.e., de facto) or (1) b. designation (i.e. de jure) the driving factor affecting performance in terms of the spatial density of fires?, and (2), Does SUR creation affect fire management (i.e., the timing of fires in relation to previous rainfall)? We demonstrate that pre-protection baselines are crucial for understanding reserve performance. We show that reserve creation had no discernible impact on fire density, and that fires were less prevalent in SURs due to their characteristics of sparser human settlement and remoteness, rather than their status de jure. In addition, the timing of fires in relation to rainfall, indicative of local fire management and adherence to environmental law, did not improve following SUR creation. These results challenge the notion that SURs promote environmentally sensitive fire-management, and suggest that SURs in Amazonia will require special attention if they are to curtail future accidental wildfires, particularly as plans to expand the road infrastructure throughout the region are realised. Greater investment to support improved fire management by farmers living in reserves, in addition to other fire users, will be necessary to help ameliorate these threats.


Asunto(s)
Conservación de los Recursos Naturales , Incendios/prevención & control , Humedad , Clima Tropical , Brasil , Geografía , Humanos , Densidad de Población , Lluvia , Análisis Espacio-Temporal
17.
PLoS One ; 10(9): e0137029, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26356842

RESUMEN

Passive optical hyperspectral remote sensing of plant pigments offers potential for understanding plant ecophysiological processes across a range of spatial scales. Following a number of decades of research in this field, this paper undertakes a systematic meta-analysis of 85 articles to determine whether passive optical hyperspectral remote sensing techniques are sufficiently well developed to quantify individual plant pigments, which operational solutions are available for wider plant science and the areas which now require greater focus. The findings indicate that predictive relationships are strong for all pigments at the leaf scale but these decrease and become more variable across pigment types at the canopy and landscape scales. At leaf scale it is clear that specific sets of optimal wavelengths can be recommended for operational methodologies: total chlorophyll and chlorophyll a quantification is based on reflectance in the green (550-560nm) and red edge (680-750nm) regions; chlorophyll b on the red, (630-660nm), red edge (670-710nm) and the near-infrared (800-810nm); carotenoids on the 500-580nm region; and anthocyanins on the green (550-560nm), red edge (700-710nm) and near-infrared (780-790nm). For total chlorophyll the optimal wavelengths are valid across canopy and landscape scales and there is some evidence that the same applies for chlorophyll a.


Asunto(s)
Pigmentos Biológicos/metabolismo , Plantas/metabolismo , Tecnología de Sensores Remotos/métodos , Análisis Espectral/métodos , Antocianinas/metabolismo , Carotenoides/metabolismo , Clorofila/análogos & derivados , Clorofila/metabolismo , Clorofila A , Luz , Hojas de la Planta/metabolismo , Publicaciones
18.
Surg Endosc ; 29(9): 2794-9, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25492453

RESUMEN

BACKGROUND: Ethnic minority adults have disproportionately higher rates of obesity than Caucasians but are less likely to undergo bariatric surgery. Recent data suggest that minorities might be less likely to seek surgery. Whether minorities who seek surgery are also less likely to proceed with surgery is unclear. METHODS: We interviewed 651 patients who sought bariatric surgery at two academic medical centers to examine whether ethnic minorities are less likely to proceed with surgery than Caucasians and whether minorities who do proceed with surgery have higher illness burden than their counterparts. We collected patient demographics and abstracted clinical data from the medical records. We then conducted multivariable analyses to examine the association between race and the likelihood of proceeding with bariatric surgery within 1 year of initial interview and to compare the illness burden by race and ethnicity among those who underwent surgery. RESULTS: Of our study sample, 66% were Caucasian, 18% were African-American, and 12% were Hispanics. After adjustment for socioeconomic factors, there were no racial differences in who proceeded with bariatric surgery. Among those who proceeded with surgery, illness burden was comparable between minorities and Caucasian patients with the exception that African-Americans were underrepresented among those with reflux disease (0.4, 95% CI 0.2-0.7) and depression (0.4, 0.2-0.7), and overrepresented among those with anemia (4.8, 2.4-9.6) than Caucasian patients. CONCLUSIONS: Race and ethnicity were not independently associated with likelihood of proceeding with bariatric surgery. Minorities who proceeded with surgery did not clearly have higher illness burden than Caucasian patients.


Asunto(s)
Cirugía Bariátrica/estadística & datos numéricos , Etnicidad , Disparidades en Atención de Salud/etnología , Grupos Minoritarios , Obesidad/cirugía , Aceptación de la Atención de Salud/etnología , Adulto , Boston/epidemiología , Costo de Enfermedad , Femenino , Disparidades en Atención de Salud/estadística & datos numéricos , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Obesidad/etnología , Aceptación de la Atención de Salud/estadística & datos numéricos
19.
Clin Endocrinol (Oxf) ; 82(3): 369-76, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24796864

RESUMEN

OBJECTIVE: Compensatory metabolic changes that accompany weight loss, for example, increased ghrelin, contribute to weight regain and difficulty in long-term weight loss maintenance; however, the separate effects of long-term caloric restriction and exercise on total circulating ghrelin in humans are unknown. DESIGN: A 12-month randomized controlled trial comparing: i) dietary weight loss with a 10% weight loss goal ('diet'; n = 118); ii) moderate-to-vigorous intensity aerobic exercise for 45 min/day, 5 days/week ('exercise'; n = 117); iii) dietary weight loss and exercise ('diet + exercise'; n = 117); or iv) no-lifestyle-change control (n = 87). PARTICIPANTS: 439 overweight or obese postmenopausal women (50-75 y). MEASUREMENTS: Fasting total serum ghrelin was measured by radioimmunoassay at baseline and 12 months. Fasting serum leptin, adiponectin and insulin were also measured. RESULTS: Fasting total ghrelin significantly increased in the diet + exercise arm (+7·4%, P = 0·008) but not in either the diet (+6·5%, P = 0·07) or exercise (+1·0%, P = 0·53) arms compared with control. Greater weight loss was associated with increased ghrelin concentrations, regardless of intervention. Neither baseline ghrelin nor body composition modified the intervention effects on changes in total ghrelin. The 12-month change in total ghrelin was inversely associated with changes in leptin, insulin and insulin resistance, and positively associated with change in adiponectin. CONCLUSIONS: Greater weight loss, achieved through a reduced calorie diet or exercise, is associated with increased total ghrelin concentrations in overweight or obese postmenopausal women.


Asunto(s)
Dieta , Ejercicio Físico/fisiología , Ghrelina/sangre , Obesidad/sangre , Sobrepeso/sangre , Pérdida de Peso/fisiología , Adiponectina/sangre , Anciano , Ayuno/sangre , Femenino , Humanos , Insulina/sangre , Leptina/sangre , Masculino , Persona de Mediana Edad , Obesidad/terapia , Sobrepeso/terapia , Radioinmunoensayo , Resultado del Tratamiento
20.
Med Sci Sports Exerc ; 47(5): 896-904, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25160845

RESUMEN

INTRODUCTION: Maintenance of normal weight and higher levels of physical activity are associated with a reduced risk of several types of cancer. Because genomic instability is regarded as a hallmark of cancer development, one proposed mechanism is improvement of DNA repair function. We investigated links between dietary weight loss, exercise, and strand break rejoining in an ancillary study to a randomized-controlled trial. METHODS: Overweight/obese postmenopausal women (n = 439) were randomized to the following: a) reduced calorie weight loss diet ("diet," n = 118), b) moderate- to vigorous-intensity aerobic exercise ("exercise," n = 117), c) a combination ("diet + exercise," n = 117), or d) control (n = 87). The reduced calorie diet had a 10% weight loss goal. The exercise intervention consisted of 45 min of moderate to vigorous aerobic activity 5 d·wk for 12 months. DNA repair capacity was measured in a subset of 226 women at baseline and 12 months from cryopreserved peripheral mononuclear cells using the comet assay. Anthropometric and body composition measures were performed at baseline and 12 months. RESULTS: DNA repair capacity did not change significantly with any of the 12-month interventions compared with control; there were also no significant changes when stratified by changes in body composition or aerobic fitness (V˙O2max). At baseline, DNA repair capacity was positively associated with weight, body mass index, and fat mass (r = 0.20, P = 0.003; r = 0.19, P = 0.004; r = 0.13, P = 0.04, respectively) and inversely with lean body mass (r = -0.14, P = 0.04). CONCLUSION: In conclusion, DNA repair capacity in cryopreserved PBMCs (Comet Assay) did not change with dietary weight loss or exercise interventions in postmenopausal women within a period of 12 months. Other assays that capture different facets of DNA repair function may be needed.


Asunto(s)
Restricción Calórica , Reparación del ADN , Dieta Reductora , Ejercicio Físico , Sobrepeso/genética , Sobrepeso/terapia , Anciano , Neoplasias de la Mama/prevención & control , Ensayo Cometa/métodos , Femenino , Humanos , Persona de Mediana Edad , Monocitos/metabolismo , Obesidad/genética , Obesidad/terapia , Posmenopausia , Factores de Riesgo
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