Nutrition & Food Science
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Item Age, Nutrition, and Bone Metabolism: Analyses of Effects Using a Short-Term In Vivo Bone Model(1987) Sinha, Rashmi; Soares, Jos; Nutritional Sciences Program; Digital Repository at the University of Maryland; University of Maryland (College Park, Md)The preventative effects of dietary calcium, zinc, and vitamin D metabolites on the net loss of bone were assessed using rats of different ages. Biochemical changes were monitored in femurs, humeri, mandibles, scapulas, and tibias. In addition femora were sectioned into epiphyses-metaphyses and diaphyses to evaluate nutritional influences on the trabecular and cortical type bone. since measurable bone degradation due to aging and nutritional status requires long period of time, a short-term in vivo system was developed to simultaneously examine bone formation and resorption. The system consisted of subcutaneous implantation of demineralized (DB) and mineralized (MB) bone powders. There was evidence of bone formation and resorption in the DB and MB implants respectively, as assessed by marker enzyme (formation-alkaline phosphatase; resorption-acid phosphatase) activities, mineral concentrations, radioisotope incorporation, and histological studies. The results indicated that several different bone samples are required to adequately predict changes occurring in the skeletal system. The epiphysesmetaphyses of long bone is a useful sample site examining changes occurring in trabecular bone while the diaphysis can assess cortical bone status. There was decreased bone formation and resorption as assessed by alkaline and acid phosphatase activity in the MB and DB implants in the 24 month-old rats as compared to 2 month-old rats. Dietary calcium and zinc levels did not affect the overall status of the bones and implants in the aged rats. Conversely, in 2 month-old rats dietary calcium at 1.0% stimulated bone formation in the DB implant, whereas 0.2% calcium increased bone resorption in the MB implants. Furthermore, 75 ng dietary 1,25-dihydroxycholecalciferol (l,25(OH) 2 D) per day increased resorption in MB implant and inhibited mineralization of DB implants in the young rats. Dietary zinc at 300 ppm reduced bone calcification in 2 month-old. The results of these studies indicated that neither high levels of dietary calcium, nor zinc, act as prophylaxes to counteract bone loss due to aging. The dietary use of l,25(OH) 2 D in old animals needs to be investigated further, since results in young animals are contradictory with reports in older rats.Item Induction of apoptosis in HeLa cells by chloroform fraction of seed extracts of Nigella sativa(Springer Nature, 2009-11-27) Shafi, Gowhar; Munshi, Anjana; Hasan, Tarique N; Alshatwi, Ali A; Jyothy, A; Lei, David KYCancer remains one of the most dreaded diseases causing an astonishingly high death rate, second only to cardiac arrest. The fact that conventional and newly emerging treatment procedures like chemotherapy, catalytic therapy, photodynamic therapy and radiotherapy have not succeeded in reverting the outcome of the disease to any drastic extent, has made researchers investigate alternative treatment options. The extensive repertoire of traditional medicinal knowledge systems from various parts of the world are being re-investigated for their healing properties. This study progresses in the direction of identifying component(s) from Nigella sativa with anti cancer acitivity. In the present study we investigated the efficacy of Organic extracts of Nigella sativa seed powder for its clonogenic inhibition and induction of apoptosis in HeLa cancer cell. Methanolic, n-Hexane and chloroform extracts of Nigella sativa seedz effectively killed HeLa cells. The IC50 values of methanolic, n-hexane, and chloroform extracts of Nigella sativa were 2.28 μg/ml, 2.20 μg/ml and 0.41 ng/ml, respectively. All three extracts induced apoptosis in HeLa cells. Apoptosis was confirmed by DNA fragmentation, western blot and terminal transferase-mediated dUTP-digoxigenin-end labeling (TUNEL) assay. Western Blot and TUNEL results suggested that Nigella sativa seed extracts regulated the expression of pro- and anti- apoptotic genes, indicating its possible development as a potential therapeutic agent for cervical cancer upon further investigation.Item RELATIONSHIPS BETWEEN LEADERSHIP AND SELF-ESTEEM CHARACTERISTICS OF PARAPROFESSIONALS AND NUTRITIONAL CHANGE IN A CLIENT SAMPLE(1974) Poffenberger, Linda L.; Longest, James W.; Nutrition & Food Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md)The study investigates the nature of the relationships between leadership and self-esteem attributes of a population of paraprofessionals and nutritional change based on records from a client sample. Sixty-five nutrition aides serving in the Expanded Food And Nutrition Education Program in Maryland and 397 program families are the subjects of the study. A survey technique was employed to gather leadership and self-esteem data for the aides and socioeconomic and nutritional data from records on a sample of client families. Relationships were hypothesized between leadership and nutritional change and self-esteem and between self-esteem and nutritional change. Non-parametric techniques were used in data analyses. Chi square and gamma coefficient were computed to determine the association between variables. The socioeconomic and nutritional characteristics of the aides and families and the relationship between family nutritional and demographic characteristics were described. Findings reveal a client group whose diets have shown improvement. Client demographic and nutritional characteristics seem independent of one another. There is little relationship between the client nutritional levels and aide characteristics. Hypothesis testing showed the leadership and self-esteem attributes of aides to be generally unrelated to the nutritional change of clients. It is concluded that the variables under study generally bear no relationship to one another. However, the exploratory nature of this study suggests it is an inadequate basis on which to evaluate paraprofessional role performance or the program. Many questions are raised and refinement and re-direction of study techniques are recommended as areas for future study.Item THE EFFICACY OF A BOILING WATER BLANCH ON THE INACTIVATION OF LISTERIA MONOCYTOGENES IN DICED CELERY(1990) Losikoff, Mary Bohrer; Westhoff, Dennis C.; Nutrition & Food Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md)The effect of a boiling water blanch on the thermal inactivation of Listeria monocytogenes in raw diced celery was investigated. L. monocytogenes, Scott A was heated in Tryptic Soy Broth with 0.6% yeast extract, pH 5.3, at 52, 54, 56, 58, and 59°C. D values were 13.33, 7.75, 1.29, 0.792, and 0.701 min, respectively. A predicted D value at 60°C = 0.36 min was obtained using a z value of 5. These thermal inactivation characteristics were subsequently used to evaluate the L. monocytogenes was recovered from inoculated (1 X 10^7 cells/g) diced raw celery after heating for 0.25 min in a laboratory boiling water blanch. Viable cells were not recovered after 0.5 min of heating. Heat penetration data for diced raw celery during a boiling water blanch were obtained in a commercial setting. These data were analyzed by the general method to determine the cumulative lethality at reference temperatures of 60°C using a z of 5 and, 70 and 71.7°C using a z of 10. It was determined that a recommended process of 2 min at 70 °C was reached in 80 sec during the blanch. Based on the findings of this study, a boiling water blanch could be used as part of the hurdles approach to eliminate L. monocytogenes from raw diced celery.Item Feasibility of Soluble Leaf Proteins as a Carrier for Vitamin D(2009) Cherian, Ansu Elizabeth; Lo, Y. Martin; Food Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Resurgence of vitamin D deficiencies in recent years has ascribed the need for expansion of fortification strategies in food. Alluding to the fat soluble and sensitive chemical nature of vitamin D, existing fortification strategies invariably require using a substantial amount of fat as carriers for vitamin D. Though milk proteins have demonstrated good binding properties with vitamin D; allergen issues, lactose intolerance, and the need to cater to vegan population deter its extensive use. In this study, soluble leaf proteins extracted from low-alkaloid tobacco leaves were investigated as a possible carrier. Crude tobacco leaf proteins were extracted by a high-throughput mechanistic process, followed by a freeze-drying process to encapsulate vitamin D. Up to 84.68% (w/w) of vitamin D was successfully retained by tobacco leaf proteins using the process developed, indicating that crude leaf protein recovered from tobacco could be employed as an effective carrier for vitamin D.Item EFFECT OF CHITOSAN ON THE INDUCTION OF DNA DAMAGE RESPONSE BY SELENIUM COMPOUNDS.(2009) Zhang, Shu; Cheng, Wen-Hsing; Nutrition; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Selenium (Se), a nutrient trace mineral, plays important roles in optimizing human health. Chitosan is an effective, natural-oriented material for synthesizing nanopolymers, with preferable properties such as biocompatibility, biodegradation and resistance to certain enzymes. In this study, encapsulated Na2SeO3 and methylseleninic acid (MSeA) with low and medium molecular weight chitosan were used to determine the efficacy of Se in mitigating tumorigenesis. We applied Se compounds, which is from sub-lethal to lethal dose, to colon cancer cell line HCT-116 and normal fibroblasts cell line MRC-5. Analysis of cellular selenium content demonstrated that: 1) Na2SeO3, but not MSeA, treatment resulted in a greater Se retention in HCT-116 than in MRC-5 cells, 2) chitosan encapsulation enhanced Se contents in cells treated with the various Se preparations. Cell survival analysis showed that chitosan encapsulation protected HCT-116 and MRC-5 cells from Na2SeO3 or MSeA induced toxicity. Moreover, this beneficial effect was greater in MRC-5 cells. MSeA encapsulated with chitosan induced phosphorylated ATM Ser-1981 formation in MRC-5 and HCT-116 cells to a less extent as compared to MSeA alone treatment. Taken together, the results suggest that, when encapsulated with chitosan, cells are less susceptible to Se treatment, possibly through a mechanism by which the presence of chitosan attenuates Se-induced activation of ATM and corresponding DNA damage response pathway.Item 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.Item 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.Item 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.Item 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.