3,007 research outputs found
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Platelet-mediated metabolism of the common dietary flavonoid, quercetin.
BACKGROUND: Flavonoid metabolites remain in blood for periods of time potentially long enough to allow interactions with cellular components of this tissue. It is well-established that flavonoids are metabolised within the intestine and liver into methylated, sulphated and glucuronidated counterparts, which inhibit platelet function. METHODOLOGY/PRINCIPAL FINDINGS: We demonstrate evidence suggesting platelets which contain metabolic enzymes, as an alternative location for flavonoid metabolism. Quercetin and a plasma metabolite of this compound, 4'-O-methyl quercetin (tamarixetin) were shown to gain access to the cytosolic compartment of platelets, using confocal microscopy. High performance liquid chromatography (HPLC) and mass spectrometry (MS) showed that quercetin was transformed into a compound with a mass identical to tamarixetin, suggesting that the flavonoid was methylated by catechol-O-methyl transferase (COMT) within platelets. CONCLUSIONS/SIGNIFICANCE: Platelets potentially mediate a third phase of flavonoid metabolism, which may impact on the regulation of the function of these cells by metabolites of these dietary compounds
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Associations of Perirenal Fat Thickness with Renal and Systemic Calcified Atherosclerosis.
BackgroundWe investigated associations between perirenal fat thickness and atherosclerotic calcification in six different vascular beds.MethodsUsing a community-based cohort (n=3,919), perirenal fat thickness was estimated from computed tomography scans. It was classified as Q1 (the lowest quartile) to Q4 (the highest quartile) in each sex. Calcification in the carotid arteries, coronary arteries, thoracic aorta, abdominal aorta, iliac arteries, and renal arteries was evaluated.ResultsPerirenal fat thickness was associated with older age (P<0.01) and a higher prevalence of obesity, hypertension, and dyslipidemia (P<0.01 for all). Perirenal fat thickness was independently associated with renal arterial calcification even after adjustment for age, sex, body mass index, hypertension, dyslipidemia, smoking history, and family history of heart diseases in first-degree relatives (odds ratio [OR] per quartile of perirenal fat thickness, 1.25; 95% confidence interval [CI], 1.09 to 1.44). Compared to Q1, the odds of renal arterial calcification in Q4 was about two times higher (OR, 2.05; 95% CI, 1.29 to 3.25). After adjustment for renal arterial calcification and atherosclerotic risk factors, the only other vascular bed where perirenal fat thickness showed a significant association with calcification was the abdominal aorta (OR, 1.11; 95% CI, 1.00 to 1.23; P=0.045).ConclusionPerirenal fat thickness was independently associated with vascular calcification in the renal artery and abdominal aorta
Results of a novel screening tool measuring dietary sodium knowledge in patients with chronic kidney disease.
BackgroundReducing dietary sodium has potential to benefit patients with chronic kidney disease (CKD). Little research is available defining dietary sodium knowledge gaps in patients with pre-dialysis CKD. We designed a brief screening tool to rapidly identify patient knowledge gaps related to dietary sodium for patients with CKD not yet on dialysis.MethodsA Short Sodium Knowledge Survey (SSKS) was developed and administered to patients with pre-dialysis CKD. We also asked patients if they received counseling on dietary sodium reduction and about recommended intake limits. We performed logistic regression to examine the association between sodium knowledge and patient characteristics. Characteristics of patients who answered all SSKS questions correctly were compared to those who did not.ResultsOne-hundred fifty-five patients were surveyed. The mean (SD) age was 56.6 (15.1) years, 84 (54%) were men, and 119 (77%) were white. Sixty-seven patients (43.2%) correctly identified their daily intake sodium limit. Fifty-eight (37.4%) were unable to answer all survey questions correctly. In analysis adjusted for age, sex, race, education, health literacy, CKD stage, self-reported hypertension and attendance in a kidney education class, women and patients of non-white race had lower odds of correctly answering survey questions (0.36 [0.16,0.81]; p = 0.01 women versus men and 0.33 [0.14,0.76]; p = 0.01 non-white versus white, respectively).ConclusionsOur survey provides a mechanism to quickly identify dietary sodium knowledge gaps in patients with CKD. Women and patients of non-white race may have knowledge barriers impeding adherence to sodium reduction advice
How to write health dialog for a talking computer
AbstractAutomated dialogue systems delivered over the telephone offer a promising approach to delivering health-related interventions to populations of individuals at low-cost. Over the past two decades, an automated telephone system called Telephone-Linked Care or TLC has been successfully designed and evaluated by the authors and their colleagues. This work has resulted in over twenty systems for various health-related conditions and lifestyle behaviors. This paper describes our approach to developing and writing dialogue for these automated telephone systems, including determining the program objectives, defining the target population, and selecting a theory of behavior change to guide the intervention. Both macro and micro issues are considered in constructing dialogue systems that are engaging for the target population, easy to use, and effective at promoting positive health behaviors and outcomes
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GRID and docking analyses reveal a molecular basis for flavonoid inhibition of src-family kinase activity
Flavonoids reduce cardiovascular disease risk through anti-inflammatory, anti-coagulant and anti-platelet actions. One key flavonoid inhibitory mechanism is blocking kinase activity that drives these processes. Flavonoids attenuate activities of kinases including phosphoinositide-3-kinase (PI3K), Fyn, Lyn, Src, Syk, PKC, PIM1/2, ERK, JNK, and PKA. X-ray crystallographic analyses of kinase-flavonoid complexes show that flavonoid ring systems and their hydroxyl substitutions are important structural features for their binding to kinases. A clearer understanding of structural interactions of flavonoids with kinases is necessary to allow construction of more potent and selective counterparts.
We examined flavonoid (quercetin, apigenin and catechin) interactions with Src-family kinases (Lyn, Fyn and Hck) applying the Sybyl docking algorithm and GRID. A homology model (Lyn) was used in our analyses to demonstrate that high quality predicted kinase structures are suitable for flavonoid computational studies. Our docking results revealed potential hydrogen bond contacts between flavonoid hydroxyls and kinase catalytic site residues. Identification of plausible contacts indicated that quercetin formed the most energetically stable interactions, apigenin lacked hydroxyl groups necessary for important contacts, and the non-planar structure of catechin could not support predicted hydrogen bonding patterns. GRID analysis using a hydroxyl functional group supported docking results. Based on these findings, we predicted that quercetin would inhibit activities of Src-family kinases with greater potency than apigenin and catechin. We validated this prediction using in vitro kinase assays.
We conclude that our study can be used as a basis to construct virtual flavonoid interaction libraries to guide drug discovery using these compounds as molecular templates
Nebraska Growers’ and Crop Consultants’ Knowledge and Implementation of Integrated Pest Management of Western Bean Cutworm
Western bean cutworm (WBC), Striacosta albicosta (Smith; Lepidoptera: Noctuidae), is a native noctuid pest of corn and dry beans in North America. While this pest has expanded its range greatly in recent years, historically it has consistently caused high yield losses in western Nebraska. A survey was distributed to growers, crop consultants and other agricultural professionals to obtain information about current management practices used for WBC. Questions covered multiple topics including: demographics, scouting practices, degree-day model use, confidence in management knowledge, Bt corn use, insecticide use, and considerations for biological control. There were 95 completed responses received by email. Respondents self-reported a significantly higher yield loss due to WBC in 2016 than in 2015 and 2014. Growers demonstrated less knowledge of WBC identification and management than crop consultants. There were frequent (58.45%) reports of Cry1F Bt corn providing decreased control against WBC. This survey identified major concerns for growers and agricultural professionals in Nebraska for WBC management. An improved understanding of WBC biology and education on management would be most beneficial for growers. Crop consultants would benefit from using more diverse management tactics including: biological control, rotation of insecticide mode-of-action, and diversifying Bt corn types
Plasmid carriage can limit bacteria–phage coevolution
Coevolution with bacteriophages is a major selective force shaping bacterial populations and communities. A variety of both environmental and genetic factors has been shown to influence the mode and tempo of bacteria–phage coevolution. Here, we test the effects that carriage of a large conjugative plasmid, pQBR103, had on antagonistic coevolution between the bacterium Pseudomonas fluorescens and its phage, SBW25ϕ2. Plasmid carriage limited bacteria–phage coevolution; bacteria evolved lower phage-resistance and phages evolved lower infectivity in plasmid-carrying compared with plasmid-free populations. These differences were not explained by effects of plasmid carriage on the costs of phage resistance mutations. Surprisingly, in the presence of phages, plasmid carriage resulted in the evolution of high frequencies of mucoid bacterial colonies. Mucoidy can provide weak partial resistance against SBW25ϕ2, which may have limited selection for qualitative resistance mutations in our experiments. Taken together, our results suggest that plasmids can have evolutionary consequences for bacteria that go beyond the direct phenotypic effects of their accessory gene cargo
Associations Between Maternal Depressive Symptoms and Nonresponsive Feeding Styles and Practices in Mothers of Young Children: A Systematic Review
Background: Childhood obesity is a significant global public health problem due to increasing rates worldwide. Growing evidence suggests that nonresponsive parental feeding styles and practices are important influences on children’s eating behaviors and weight status, especially during early childhood. Therefore, understanding parental factors that may influence nonresponsive parental feeding styles and practices is significant for the development of interventions to prevent childhood obesity.
Objective: The objectives of this systematic review were to (1) identify and review existing research examining the associations between maternal depressive symptoms and use of nonresponsive feeding styles and practices among mothers of young children (2-8 years of age), (2) highlight the limitations of reviewed studies, and (3) generate suggestions for future research.
Methods: Using the PRISMA (Preferred Reporting Items for Systematic review and Meta-Analysis Protocols) guidelines, six electronic academic databases were searched for peer-reviewed, full-text papers published in English between January 2000 and June 2016. Only studies with mothers 18+ years old of normally developing children between 2 and 8 years of age were included. Of the 297 citations identified, 35 full-text papers were retrieved and 8 were reviewed.
Results: The reviewed studies provided mixed evidence for associations between maternal depressive symptoms and nonresponsive feeding styles and practices. Two out of three studies reported positive associations with nonresponsive feeding styles, in that mothers with elevated depressive symptoms were more likely than mothers without those symptoms to exhibit uninvolved and permissive or indulgent feeding styles. Furthermore, results of reviewed studies provide good evidence for association between maternal depressive symptoms and instrumental feeding (3 of 3 reviewed studies) and nonresponsive family mealtime practices (3/3), but mixed evidence for pressuring children to eat (3/6) and emotional feeding (1/3). In addition, evidence for the association between maternal depressive symptoms and restricting child food intake was mixed: one study (1/6) found a positive association; two studies (2/6) found a negative association; whereas one study (1/6) found no association.
Conclusions: This review indicates that the results of studies examining the associations between maternal depressive symptoms and parental feeding styles and practices are mixed. Limitations of studies included in this review should be noted: (1) the use of a diverse set of self-report questionnaires to assess parental feeding practices is problematic due to potential misclassification and makes it difficult to compare these outcomes across studies, thus caution must be taken in drawing conclusions; and (2) the majority of included studies (6/8) were cross-sectional. There is a need for additional longitudinal studies to disentangle the influence of depression on parental feeding styles and practices. Nevertheless, given that depressive symptoms and feeding styles and practices are potentially modifiable, it is important to understand their relationship to inform obesity prevention interventions and programs
Assessing Parental Self-Efficacy for Obesity Prevention Related Behaviors
Background: Reliable, valid and theoretically consistent measures that assess a parent’s self-efficacy for helping a child with obesity prevention behaviors are lacking.
Objectives: To develop measures of parental self-efficacy for four behaviors: 1) helping their child get at least 60 minutes of moderate intensity physical activity every day, 2) helping one’s child consume five servings of fruits and vegetables each day, 3) limiting sugary drinks to once a week, and 4) limiting consumption of fruit juice to 6 ounces every day.
Methods: Sequential methods of scale development were used. An item pool was generated based on theory and qualitative interviews, and reviewed by content experts. Scales were administered to parents or legal guardians of children 4–10 years old. The item pool was reduced using principal component analysis. Confirmatory factor analysis tested the resulting models in a separate sample.
Subjects: 304 parents, majority were women (88%), low-income (61%) and single parents (61%). Ethnic distribution was 40% Black and 37% white.
Results: All scales had excellent fit indices: Comparative fit index \u3e .98 and chi-squares (Pediatrics 120 Suppl 4:S229-253, 2007) = .85 – 7.82. Alphas and one-week test-retest ICC’s were ≥ .80. Significant correlations between self-efficacy scale scores and their corresponding behaviors ranged from .13-.29 (all p \u3c .03).
Conclusions: We developed four, four-item self-efficacy scales with excellent psychometric properties and construct validity using diverse samples of parents
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