34 research outputs found
The effect of garlic supplementation on flow-mediated dilation after acute maximal exercise
Antioxidative compounds found in garlic may overcome exercise-induced oxidative stress (OS) and attenuate any associated decrease in endothelial function, perhaps leading to performance improvements in high intensity exercise. The purpose of the current study was to investigate whether or not a single dose garlic supplement induced positive changes to flow-mediated dilation (FMD), a measure of nitric oxide mediated endothelial function, in young, trained adults before and after maximal exercise. Maximal oxygen consumption (VO2max) was measured to determine if any changes in FMD were associated with performance improvements. A total of 11 trained participants (aged 20.64 ± 2.25 yrs) were included in the analysis. Participants were randomized to receive either the placebo, which contained 900 mg of all-purpose flour, or 900 mg of powdered garlic three hours prior to data collection. Flow-mediated dilation measurements were taken following 20 min rest (PRE), immediately following a treadmill VO2max test (IPE), and 1-hour post-exercise (1HR). All FMD measurements were taken in the right arm. This protocol was repeated with either the placebo or garlic supplement (depending upon randomization) at least two weeks after the initial test date. Although relative (garlic = 61.20 ± 6.44 ml•kg•min-1, placebo = 59.09 ± 6.96 ml•kg•min-1, p = 0.021) and absolute (garlic = 4.57 ± 0.61 L•min-1, placebo = 4.44 ± 0.52 L•min-1, p = 0.045) VO2max were higher in the garlic trial, no significant differences were found between PRE, IPE, or 1HR- FMD (PRE garlic: 0.068 mm ± 0.032 mm, PRE placebo: 0.071 mm ± 0.051 mm, IPE garlic: 0.091 mm ± 0.119 mm, IPE placebo: 0.071 mm ± 0.084 mm, 1HR garlic: 0.084 mm ± 0.097 mm, 1HR placebo: 0.108 mm ± 0.097 mm; p = 0.479). In addition, there were no significant differences found between PRE, IPE, and 1HR peak lumen diameter measurements (p = 0.524), or between PRE, IPE, and 1HR time to peak diameter measurements (p = 0.641). The results of the current study suggest that a single-dose garlic supplement improves VO2max in young, healthy subjects but that the improvements are not related to alterations in NO bioavailability as measured by FMD
Biological Misinterpretation of Transcriptional Signatures in Tumor Samples Can Unknowingly Undermine Mechanistic Understanding and Faithful Alignment with Preclinical Data
PURPOSE
Precise mechanism-based gene expression signatures (GES) have been developed in appropriate in vitro and in vivo model systems, to identify important cancer-related signaling processes. However, some GESs originally developed to represent specific disease processes, primarily with an epithelial cell focus, are being applied to heterogeneous tumor samples where the expression of the genes in the signature may no longer be epithelial-specific. Therefore, unknowingly, even small changes in tumor stroma percentage can directly influence GESs, undermining the intended mechanistic signaling.
EXPERIMENTAL DESIGN
Using colorectal cancer as an exemplar, we deployed numerous orthogonal profiling methodologies, including laser capture microdissection, flow cytometry, bulk and multiregional biopsy clinical samples, single-cell RNA sequencing and finally spatial transcriptomics, to perform a comprehensive assessment of the potential for the most widely used GESs to be influenced, or confounded, by stromal content in tumor tissue. To complement this work, we generated a freely-available resource, ConfoundR; https://confoundr.qub.ac.uk/, that enables users to test the extent of stromal influence on an unlimited number of the genes/signatures simultaneously across colorectal, breast, pancreatic, ovarian and prostate cancer datasets.
RESULTS
Findings presented here demonstrate the clear potential for misinterpretation of the meaning of GESs, due to widespread stromal influences, which in-turn can undermine faithful alignment between clinical samples and preclinical data/models, particularly cell lines and organoids, or tumor models not fully recapitulating the stromal and immune microenvironment.
CONCLUSIONS
Efforts to faithfully align preclinical models of disease using phenotypically-designed GESs must ensure that the signatures themselves remain representative of the same biology when applied to clinical samples
Improved reference genome of Aedes aegypti informs arbovirus vector control
Female Aedes aegypti mosquitoes infect more than 400 million people each year with dangerous viral pathogens including dengue, yellow fever, Zika and chikungunya. Progress in understanding the biology of mosquitoes and developing the tools to fight them has been slowed by the lack of a high-quality genome assembly. Here we combine diverse technologies to produce the markedly improved, fully re-annotated AaegL5 genome assembly, and demonstrate how it accelerates mosquito science. We anchored physical and cytogenetic maps, doubled the number of known chemosensory ionotropic receptors that guide mosquitoes to human hosts and egg-laying sites, provided further insight into the size and composition of the sex-determining M locus, and revealed copy-number variation among glutathione S-transferase genes that are important for insecticide resistance. Using high-resolution quantitative trait locus and population genomic analyses, we mapped new candidates for dengue vector competence and insecticide resistance. AaegL5 will catalyse new biological insights and intervention strategies to fight this deadly disease vector
Fruit and vegetable intake, physical activity, and functional fitness among older adults in urban Alaska
Older adults often face barriers to obtaining recommended diet, physical activity, and fitness levels. Understanding these patterns can inform effective interventions targeting health beliefs and behavior. This cross-sectional study included a multicultural sample of 58 older adults (aged 55+ years, M=71.98) living in independent senior housing in urban Southcentral Alaska. Participants completed a questionnaire and the Senior Fitness Test that assessed self-reported fruit and vegetable intake, physical activity, self-efficacy, and functional fitness. T-tests and bivariate correlation analyses were used to test six hypotheses. Results indicated that participants had low physical activity but had a mean fruit and vegetable intake that was statistically significantly higher than the hypothesized “low” score. Only 4.26% of participants met functional fitness standards for balance/agility, and 8.51% met standards for lower-body strength. However, 51.1% met standards for upper-body strength and 46.8% met standards for endurance The results also indicated that nutrition self-efficacy and exercise self-efficacy were positively related to fruit and vegetable intake and physical activity levels, respectively. Interestingly, income was not related to nutrition or activity patterns. These data complicate the picture on dietary and physical activity patterns for older adults in Alaska and offer recommendations for future health promotion activities
Cardiometabolic risk among rural Native American adults in a large multilevel multicomponent intervention trial.
This cross-sectional analysis of the baseline evaluation sample of the Obesity Prevention and Evaluation of InterVention Effectiveness in Native Americans 2 (OPREVENT2) study included 601 Native American adults ages 18-75 living in rural reservation communities in the Midwest and Southwest United States. Participants completed a self-report questionnaire for individual and family history of hypertension, heart disease, diabetes and obestiy. Body mass index (BMI), percent body fat, and blood pressure were measured by trained research staff. About 60% of respondents had a BMI >30 kg/m2. Approximately 80% had a waist-to-hip ratio and percent body fat classified as high risk, and nearly 64% had a high-risk blood pressure measurement. Although a large proportion of participants reported a family history of chronic disease and had measurements that indicated elevated risk, relatively few had a self-reported diagnosis of any chronic disease. Future studies should examine potential connections between healthcare access and discordance in self-reported versus measured disease risks and diagnoses
Efecto de la combinación fungicida protectante y variedad sobre el tizón tardío [Phythopthora Infestas (Montagne) De Bary] en el cultivo de papa (Solanum tuberosum L.) en época de primera localidad La Tejera, San Nicolás, Estelí, 2008
El objetivo principal de este estudio fue el de evaluar el efecto de tres intervalos de aplicación del fungicida clorotalonil y tres variedades de papa con diferentes niveles de resistencia sobre la epidemiología y manejo del tizón tardío [Phytophthora infestans (Montagne) De Bary] en el cultivo de papa (Solanum tuberosum L.) El trabajo experimental se realizó de Julio a Octubre 2008, en la localidad “La Tejera”, municipio de San Nicolás, departamento de Estelí, localizado en las coordenadas geográficas 12º58'23” latitud norte y 86º24'21” longitud oeste, a una altura de 1,328 metros sobre el nivel del mar.
Se evaluaron doce epidemias de tizón tardío que resultaron de la combinación de tres variedades de papa (Cal White, Granola y Jacqueline Lee) y cuatro tratamientos (tres
intervalos de aplicación del fungicida clorotalonil y un testigo en el cual no se aplicó fungicida). Los
tratamientos fueron distribuidos en bloques completos al azar. El manejo experimental fue el mismo que realiza el productor convencionalmente. Las variables epidemiológicas evaluadas fueron: severidad, área bajo la curva de progreso de la enfermedad (ABCPE) y la tasa de infección aparente (r). Además, se midieron variables climáticas
como temperatura, humedad relativa y precipitaciones y se determinó el rendimiento de las variedades incluidas en el estudio. Las doce epidemias analizadas en este estudio iniciaron con varios días de diferencia, en dependencia del nivel de resistencia de la variedad y del intervalo de aplicación del fungicida protectante clorotalonil. La
severidad de la enfermedad alcanzó casi el 100% en las variedades susceptibles (Cal White y Granola) en las parcelas donde no se aplicó el fungicida clorotalonil, pero el porcentaje de severidad en las parcelas tratadas disminuyó conforme el intervalo de aplicación se fue
acortando. En la variedad Jacqueline Lee los porcentajes de severidad fueron bajos, incluso en las parcelas que no fueron tratadas con el fungicida clorotalonil, lo cual demuestra que esta variedad es resistente a P. infestans. Ninguno de los intervalos de aplicación (cada 4, 7 y 14 días) del fungicida clorotalonil detuvo el avance de las epidemias de tizón tardío una vez que éstas iniciaron, principalmente, en las parcelas con variedades susceptibles.
El rendimiento obtenido en cada una de las variedades evaluadas fue menor al compararlo con otro estudio de validación llevado a cabo en 2007 en tres localidades de Matagalpa y Jinotega. Los resultados de este estudio const
ituyen una contribución muy importante para el desarrollo de futuras estrategias encaminadas, no a la erradicación total del tizón tardío de los campos de papa y/o tomate de Nicaragua, pero si para lograr mitigar su efecto
devastador sobre tan importantes cultivos tanto desde el punto de vista nutritivo como económico