Nutrition & Food Science

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End date: 2009Subject: search.filters.subject.Health Sciences, Nutrition

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    HOW SELENIUM MODIFIES CROSS-TALK BETWEEN THE PIKK FAMILY AND INSIGHTS ON THE REGULATION OF DNA-PKcs
    (2009) Rocourt, Caroline; Cheng, Wen-Hsing; Nutrition; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    We recently found that ATM is required for a selenium-induced senescence response in non-cancerous cells. We hypothesize the selenium-induced DNA damage response modifies ATM and DNA-PKcs cross-talk. Phospho-specific antibodies against ATM and DNA-PKcs were used to follow the phosphorylation events after selenium treatment in normal human cells and two human cancer cell lines. Results from immunofluorescence analysis showed that selenium treatment induces hyperphosphorylation of DNA-PKcs at T2647 and S2056 in non-cancerous MRC-5 cells but not in U-2 OS cancer cells. Further studies in MRC-5 cells treated with an ATM kinase inhibitor, KU 55933, showed attenuation of the selenium-induced DNA-PKcs phosphorylation at both foci, whereas pre-treatment with a DNA-PKcs kinase inhibitor, NU 7026, does not prevent ATM phosphorylation at S1981, an event leading to ATM pathway activation. These results give evidence that DNA-PKcs and ATM have a cooperative role in the DNA damage response pathway.
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    High Sucrose, Fructose, and Glucose Diets and Glucocorticoid Dysregulation in Rats
    (2009) London, Edra; Castonguay, Thomas W; Nutrition; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Approximately two-thirds of U.S. adults are overweight or obese and the prevalence of overweight in children has tripled since 1980. Intake of added sugars has also increased. The etiology of obesity remains unclear and the role of glucocorticoids in obesity is one area of ambiguity. The enzyme 11beta-hydroxysteroid dehydrogenase-1 (11beta-HSD-1) interconverts active and inactive glucocorticoid, thereby regulating intracellular glucocorticoids. Dysregulation of 11beta-HSD-1 in liver and adipose is characteristic of human and animal models of obesity. Hexose-6-phosphate dehydrogenase (H6PDH) is colocalized with 11beta-HSD-1 and determines the set point for 11beta-HSD-1 oxidoreductase activity. In a long-term (10 wk) study, rats given ad libitum access to 16% sucrose solution, chow, and water were fatter than controls, had increased 11beta-HSD-1 mRNA in adipose, suppressed 11beta-HSD-1 mRNA in liver, and increased H6PDH mRNA in both tissues. The primary research questions were as follows: Can high sugar diets induce glucocorticoid dysregulation in the absence of excess adiposity? Does sugar type matter? Energy intake, weight gain, and parameters of lipid and carbohydrate metabolism were measured. Rats were randomly assigned to either ad libitum access to chow and water only (control), or in addition to ad libitum access to either 16% sucrose, fructose, or glucose solution (n=16/gp). After 24h and 1 wk, eight rats per group were randomly selected for sacrifice. Daily caloric intakes among sugar-fed groups did not differ and were higher than the mean intake of the control group. Within 24h, fructose induced increased 11beta-HSD-1 message in mesenteric adipose and liver. Plasma TG and insulin were acutely increased in groups with fructose-containing diets only. All high sugar diets induced suppressed hepatic 11beta-HSD-1 mRNA and protein after 1 wk. Upregulation of H6PDH mRNA observed in response to long-term high sucrose diets may result from increased adiposity and not solely diet. High sugar diets, irrespective of sugar type, initiate glucocorticoid dysregulation in the absence of phenotypic changes associated with obesity. Sucrose, fructose, and glucose have distinct metabolic and endocrine responses. Fructose has the unique ability to induce glucocorticoid dysregulation in liver and adipose in 24h.
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    Appropriate Waist Circumference Cutoff Values for the Diagnosis of Metabolic Syndrome in Mexican American Adults
    (2009) Sarafrazi, Neda; Jackson, Robert T; Nutrition; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Metabolic syndrome increases the risk of cardiovascular disease and diabetes. The International Diabetes Federation (IDF) recently proposed new criteria for the diagnosis of metabolic syndrome, which requires the presence of central obesity as measured by ethnic specific waist circumference (WC) cutoff values. Currently, no specific WC thresholds for diagnosis of central obesity in Hispanics are available. The objectives were to determine the appropriate gender specific WC thresholds for diagnosis of central obesity in Mexican American adults and to estimate the prevalence of metabolic syndrome using IDF definition with and without the modified WC in this population. Data from 3265 Mexican American adults aged 20-80 years who participated in the National Health and Nutrition Examination Survey 1999-2006 were used. The prevalence of metabolic syndrome was compared using IDF criteria with and without the modified waist circumference. Receiver operating characteristic curve analysis suggested that yielding at least 80% sensitivity, the WC value of 90 cm in both genders was more appropriate in predicting the presence of two or more metabolic syndrome risk factors in this population. Based on this cutoff, there was 34% reduction in the prevalence of central obesity in women (82.5% to 54.2%). The age adjusted prevalence of metabolic syndrome decreased from 58.4 to 48.2%. The metabolic syndrome was more common among Mexican American men than women (55.8% in men versus 37.8% in women, P =0.0003). Our findings provided a practical guidance in the assessment and screening of central obesity and metabolic syndrome in Mexican Americans.
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    THE FUNCTION OF MRN (MRE11-RAD50-NBS1) COMPLEX DURING WRN (WERNER) FACILITATED ATM (ATAXIA-TELANGIECTASIA MUTATED) ACTIVATION
    (2009) Ma, Junhao; Cheng, Wen-Hsing; Nutrition; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    WRN (Werner) protein is a member of the RecQ family showing helicase and exonuclease activity. WRN protein may lose function upon mutation and causes Werner syndrome (WS) which is an autosomal recessive, cancer-prone and premature aging disease. ATM (Ataxia-Telangiectasia mutated) protein initiates a signaling pathway in response to DNA double strand breaks (DSBs). Genomic disorder ataxia-telangiectasia (A-T) is associated with defective ATM. WRN protein is involved in ATM pathway activation when cells are exposed to DSBs associated with replication fork collapse. Because the Mre11-Rad50-Nbs1 (MRN) complex, a sensor of DSBs, is known to interact with WRN and ATM, we investigated whether the MRN complex mediates the WRN-dependent ATM pathway activation. In this study, we employed short-hairpin RNA to generate WRN- and Nbs1-deficient U-2 OS (osteosarcoma) cells. Cells were treated with clastogens which induce collapsed replication forks, thus provided proof for whether WRN facilitates ATM activation via MRN complex. This study serves as a basis for future investigation on the correlation between ATM, MRN complex and WRN, which will ultimately help understand the mechanism of aging and cancer.
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    Depression and Hardiness and their Association with Appetite in Older Adults
    (2009) Engel, Julia; Sahyoun, Nadine; Nutrition; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Poor appetite is common among older adults, and is influenced by factors including chronic disease and depression. The aim of this research is to examine the associations of hardiness (defined as the ability to manage stress), depression, and emotional well-being with appetite in older adults. A survey evaluating hardiness, depression and appetite was administered to 292 adults (60 years and older), at assisted-living facilities or senior centers in the Washington D.C. area. In univariate models, depression, hardiness, and emotional well-being are associated with appetite. In multivariate models, fair/poor emotional well-being increases risk for poor appetite (OR=5.60, 95% CI= 2.60-12.07) and commitment (a dimension of hardiness - which indicates an individual's involvement in life) is associated with appetite (OR=1.35, 95% CI= 1.13-1.61). These variables maintained the strongest associations with appetite in multivariate models. These associations further elucidate the components of mental health which contribute to poor appetite in this population.
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    The effect of trifolirhizin and resveratrol on human prostate cells
    (2008-11-21) Zhang, Junjun; Lei, David K. Y.; Nutrition; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Trifolirhizin is a potent polycyclic flavonoid with anticarcinogenic effects. The treatment of 25 μM trifolirhizin in human derived prostate cancer LNCaP cells for 6 days decreased cell proliferation by 40%. Higher dosages caused the proliferation inhibition effect to be manifested in as early as 3 days. Another prostate cancer cell line, PC-3, was not affected by trifolirhizin till 125 μM resulting in about 45 % reduction in cell proliferation after 4 to 6 days of incubation. Most importantly, for normal human prostate epithelial (NHPrE) cells, trifolirhizin was effective only at the highest concentration of 200 µM. The proliferation inhibition in trifolirhizin-treated LNCaP and PC-3 cells was associated with cell cycle arrest at the G0/G1 and G2/M phase, respectively. Moreover, the expression of cyclin E was unchanged but that of cyclin D1, p53, p21 and p-Rb was suppressed in 50 μM trifolirhizin-treated LNCaP cells. To evaluate the influence of resveratrol on cellular zinc status, NHPrE cells were treated with 6 levels of resveratrol (0, 0.5, 1, 2.5, 5 and 10 μM) and 4 levels of zinc [0, 4, 16 and 32 μM representing zinc deficient (ZD), zinc normal (ZN), zinc adequate (ZA) and zinc supplemented (ZS), respectively]. Among each zinc treatment, a progressive reduction in cell growth or increase in cellular total zinc was observed with increases of resveratrol from 2.5, 5 and 10 μM or from 5 and 10 μM, respectively. In ZS cells a much higher increase in cellular total zinc was observed as early as 1 μM resveratrol. The resveratrol (10 μM) induced G2/M arrest was found to be responsible for the depressed cell proliferation. An in vitro experiment demonstrated complex formation between resveratrol and zinc ion. Fluorescent spectrofluorimetry and microscope imaging revealed that intracellular free labile zinc decreased in resveratrol-treated ZD and ZN NHPrE cells but increased in high zinc (ZA and ZS) cells. Furthermore, increases in cellular zinc status induced reactive oxygen species (ROS) generation as well as senescence in cells treated with 2.5 or 10 μM resveratrol, especially in ZA and ZS cells. Thus, increase in free labile zinc may induce ROS and senescence.
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    Short-term Home-Delivered Meal Intervention and the Health, Nutrition and Functional Status of Hospital-discharged Older Adults
    (2008-11-21) Akobundu, Ucheoma Onyinyechi; Sahyoun, Nadine R; Nutrition; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Background: Following discharge from the hospital, homebound older adults remain at risk of poor dietary intake and adverse outcomes due to declines in health experienced during hospitalization. However, once home, timely receipt of in-home nutrition services by older adults is challenged by gaps in the continuum of care. Greater insight into the nutrition and wellness service needs of this population is needed to improve service coordination. Methods: Staff at six home-delivered meal (HDM) programs in six US states enrolled 566 hospital-discharged, homebound older adults into a five-month HDM intervention project. Sociodemographic, nutrition and health risk data were collected at baseline, at 2 months after the initial assessment or at termination of home delivered meal services, and at 5 months after the initial assessment. Statistical Analyses: Bivariate and multivariate analyses were used to examine relationships between sociodemographic, social, nutritional, and health risk factors, and participant food shopping/meal preparation ability. In addition, associations between these risk factors, adverse changes in living arrangement and short-term HDM program participation were evaluated. An assessment of the food items and cooking appliances available in the home was also performed. Results: This dissertation suggests that among the hospital-discharged older adults studied: (a) many had a variety of foods available but reported being unable to prepare meals, (b) those who experienced adverse changes in living arrangement over the course of the intervention were more likely to report poor health and nutrition status, functional impairment, and social isolation following hospital discharge, and finally, (c) those who maintained or restored their ability to accomplish food-related instrumental activities of daily living such as shopping and preparing meals were shorter-term users of HDM compared to longer-term users. Conclusion: Homebound older adults can benefit from timely enrollment to community-based programs nutrition and wellness services like HDM, especially those who are unable to shop and prepare meals. There is also a need at discharge to identify social, functional and nutritional risk factors for adverse outcomes in older adult patients in order to provide appropriate referrals to nutrition and wellness services that can facilitate successful transitions from hospital to home.
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    Dietary Patterns, Metabolic Risk and Survival in Older Adults
    (2008-10-28) Anderson, Amy Louise; Sahyoun, Nadine R.; Nutrition; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Background: Recent evidence suggests that older adults' diets can appreciably impact their health. Dietary patterns may better capture the multifaceted effects of diet on health than individual nutrients or foods. Objectives: The purpose of this study was to identify the dietary patterns of a cohort of older adults, and examine relationships with body composition, insulin sensitivity, systemic inflammation, and survival. The influence of a polymorphism in the peroxisome proliferator-activated receptor-γ (PPAR-γ) gene was considered. Design: The Health, Aging and Body Composition (Health ABC) Study is a prospective cohort study of 3075 older adults. Participants' body composition, genetic variation, glucose metabolism, systemic inflammation, and vital status were evaluated in detail. Food intake was assessed with a modified Block food frequency questionnaire (FFQ), and dietary patterns were derived by cluster analysis. Results: Six clusters were identified, including a 'Healthy foods' cluster characterized by higher intake of lowfat dairy products, fruit, whole grains, poultry, fish and vegetables. An interaction was found between dietary pattern and PPAR-γ Pro12Ala genotype in relation to body composition. While Pro homozygotes in the 'Healthy foods' cluster did not differ significantly in body composition from those in other clusters, men with the Ala allele in the 'Healthy foods' cluster had significantly lower adiposity than those in other clusters. The 'Healthy foods' cluster had lower fasting insulin and HOMA-IR values than the 'High-fat dairy products' and 'Breakfast cereal' clusters, while no differences were found in fasting or 2-hour glucose. With respect to inflammation, the 'Healthy foods' cluster had lower levels of IL-6 than the 'High-fat dairy products' and 'Sweets and desserts' clusters, and did not differ in CRP or TNF-α. The 'Healthy foods' cluster also had a lower risk of mortality than the 'High-fat dairy products' and 'Sweets and desserts' clusters, and more years of healthy life and more optimal nutritional status than the other clusters. Conclusion: A dietary pattern consistent with current guidelines to consume relatively high amounts of vegetables, fruit, whole grains, poultry, fish and lowfat dairy products may reduce the metabolic risk and improve the nutritional status, quality of life and survival of older adults.
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    The Prevalence and Selected Determinants of Overweight and and Obesity Among Children and Adolescent in the City of Al-Ain, UAE
    (2008-02-01) Al-Shamsi, Reem Saeed; Jackson, Robert T; Nutrition; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Obesity is a serious epidemic that is increasing rapidly worldwide. Obesity in the UAE is associated with the rapid increase of wealth and the dramatic impact of economic development since the oil boom in the 1930s. The aim of the study is to determine the childhood obesity rates in Al-Ain City by comparing the CDC 2000 and IOTF BMI cut offs with various factors associated with overweight and obesity among children and adolescents. Data were obtained from 10 schools in Al-Ain for both male and female students ages from 8 to 16 years. The prevalence of overweight and obesity using CDC were 12% boys; 12.7% girls and 14% boys; 13.6% girls, respectively. Using the IOTF, 14.5% boys and 17.6% girls were overweight and 9.6% in boys and 12.9% girls were obese. Overweight and obesity are prevalent in Al-Ain City. Underweight seems to be another public health concern among schoolchildren.
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    From China to the US: nutrition, diet and acculturation of Chinese employed in high-tech industries - Results from a web-based survey
    (2007-08-06) Wang, Chunling; Sahyoun, Nadine; Nutrition; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Background: Due to the fast development of economies in China and the great needs of professionals in the US, the population of highly educated young Chinese professionals working in high-tech industries has grown very fast in both countries. This population was suggested to have risk of consuming high energy and fat diet in both countries. Objectives: This study aimed to investigate the associations of dietary intake with nutrition knowledge, attitude, dietary self-efficacy and acculturation among Chinese working in high-tech industries in China and in the US. Methods: This study was a cross-sectional self-administered online survey. We studied 925 Chinese aged 20-45 years, who worked in high-tech industries and had at least a bachelor degree in four sub-groups: employees of Chinese companies in China; employees of American companies in China; Chinese-born immigrant in the US; and American-born Chinese in the US. A web-based questionnaire including a food frequency questionnaire (FFQ) was developed to assess total energy and fat intakes, nutrition knowledge, attitudes, dietary self-efficacy. Four domains of acculturation were assessed among Chinese in the US. Using these data, we compared the four sub-groups and tested the prediction model of dietary intake and BMI. Results: Our results showed that American-born Chinese participants consumed significantly higher energy and fat than the other three groups. Participants in the US had higher nutrition knowledge, attitude and self- efficacy than participants in China. Chinese-born immigrant men in the US had the highest nutrition knowledge and attitude and the lowest prevalence of overweight among the four study groups of men. The study results suggested that preferring Chinese food and Chinese leisure activity are predictors of lower energy and fat intake in Chinese-born immigrants. Conclusions: The Chinese-born immigrants showed significant advantages in nutrition knowledge, attitude, and dietary self-efficacy and had the lowest prevalence of overweight in men. American-born Chinese consumed the highest energy and fat among the four study groups even though their nutrition knowledge, attitude and self-efficacy were high. Future nutrition promotion programs should make use of these cultural and environmental differences when designing theses programs. The web-based survey method can be utilized in future nutrition research.