Browsing by Subject "Food Science"
Now showing 1 - 8 of 8
- Results Per Page
- Sort Options
Item Dietary Quality In The United States: An Evaluation Of The American Diet Using The Mediterranean Diet Index(2003-12-01) LaFontaine, Laura Jean; Sejong BaeLaFontaine, Laura Jean, Dietary Quality in the United States: An Evaluation of the American Diet Using the Mediterranean Diet Index. Master of Public Health (Epidemiology), December 2003, 69 pp., 10 tables, 3 figures, reference list, 92 titles. Mediterranean Diet Index (MDI) score is positively associated with increased longevity in diverse populations. High scores are characterized by high intake of fruit, vegetables, legumes, fish, and grains; low intake of meat and dairy; moderate alcohol intake; and high monounsaturated to saturated fat ratio. Dietary quality 7,772 individuals ages 2 and older in the NHANES 1999-2000 sample was assessed using the MDI. Mean MDI scores were low overall and across all population groups. Highest mean scores (3.03-3.13) were observed in children 2-3 and adult men; lowest scores (2.76-2.77) were observed in adolescents. High scores were associated with foreign-born status, higher education level, increasing age in adults, and decreasing age in children.Item Endurox R4® & Gatorade®: Effects of Recovery Drinks After Prolonged Glycogen-Depleting Exercise(1999-06-01) Williams, Michael Brandon; Raven, Peter B.; Smith, Michael; Shi, XiangrongWilliams, Michael B., Endurox R4® & Gatorade®: Effects of Recovery Drinks After Prolonged Glycogen-Depletion Exercise. Master of Science (Biomedical Sciences, Integrative Physiology), June, 1999, 73 pp., 2 tables, 18 figures, references. Purpose: Eight high-fit (bicycle Vo2max=62.4 ± 1.10 ml·kg-1·min-1) male cyclists, aged 28.4±1.65 yrs, performed a two-hour endurance bicycle exercise to achieve depletion of skeletal muscle and liver glycogen. During recovery, Endurox R4 Recovery Drink®, or Gatorade®, was ingested to investigate their relative restorative capacities to enable further exercise. Methods: Each subject performed two days of testing: one for each drink presented in random order. On each testing day, the twelve-hour fasted subject performed a two-hour cycling exercise bout at 75% VO2max followed by one to three five-minute sprints at 85% VO2max. At the end of the exercise blood glucose concentrations were 3.98±0.138 mmol/L. A four hour recovery period ensued in which the subject was given 24-ounces of the recovery drink. A performance test at 85% VO2max to exhaustion was then conducted. Ventilatory responses were collected breath-to-breath, while venous blood samples were measured for oxidation products, glucose and insulin concentrations. Results: The recovery phase showed significant increases in both plasma glucose and serum insulin following Endurox R4 Recovery Drink® ingestion as compared to Gatorade®. There was a significant increase in time to exhaustion (+55%) following Endurox R4 Recovery Drink® during the performance ride compared to Gatorade®. Final oxidation products following Endurox R4 Recovery Drink® ingestion were significantly decreased as compared to Gatorade® ingestion, in that Thiobarbituric Acid Reactive Substrates (T-BARS) were significantly decreased. Conclusions: These data indicate that the Endurox R4 Recovery Drink®, when compared to Gatorade®, significantly enhanced recovery from glycogen-depleting exercise. In addition, Endurox R4 Recovery® Drink decreased the formation of final oxidation products, when compared to Gatorade®.Item Genetic Engineering and the Food Supply(2000-12-01) Kennedy, W. Russ; Samuel F. AtkinsonAs food sources high in the trees became inadequate, our predecessors climbed to the ground and through centuries of adaptation learned to stand upright and cultivate plants. Plant cultivation has been practiced for more than ten thousand years with continuous improvements made to crop plants to meet the growing food needs of human domesticated animal populations. Biotechnology has been practiced for thousands of years with fermentations of fruits and grains to make wine and beer and the use of yeast in baking. More recently, advances in molecular biology allow the analysis and manipulation of genetic material to achieve desired changes in the organism. Transgenics or genetic engineering is the process of identifying specific genetic defects or desirable traits and altering an organism’s DNA by addition or deletion of specific DNA sequences. Nearly 100 million acres (40 million hectares) were planted in transgenic crops in 1999. The largest acreages of more than 40 different transgenic crops grown were in cotton, corn, soybean and rapeseed. Fifty-five percent of all cotton, 50% of soybeans, and 33% of corn grown in the U.S. in 1999 were transgenic varieties. The large plantings stem from fairly straightforward manipulations of single genes, such as the transferring to corn and cotton genetic material from the bacterium Bacillus thuringiensis (Bt) which produces an insecticidal toxin or transferring to the soybean, corn, cotton, sugar beets, and canola a gene with resistance to herbicides, such as glyphosate. The American farmer is perceived to be the beneficiary of lowered production costs primarily through better weed and pest control and a reduction in pesticide use with accompanying environmental improvement. Agro-chemical companies, who for the most part have spearheaded research and development of these crops, became involved because they foresaw a declining market for pesticides. Another area of promise widely discussed in the scientific and popular press is the improvement of food quality and composition resulting from genetic engineering. Because plants and plant products provide much of the world’s food supply, it is only fitting that early applications of this technology be in this area. Recent estimates suggest that the market for transgenic seed has already reached several hundred million dollars per year and that more than 15 million hectares (37 million acres) were grown in the U.S. in 1998. Concerns of food risk to the food supply and environment that using transgenic methods present, although not always science based, have some merit and require careful scientific scrutiny.Item Meta-analysis: Effects of Opuntia Species(2000-05-01) Garcia, Anna R.; John Licciardone; Gilbert Ramirez; FongGarcia, Anna R., Meta-analysis: Effects of Opuntia species. Master of Public Health (Epidemiology), May, 2000, 73 pp., 10 tables, 10 figures, references, 62 titles. The Mexican American population is more susceptible to diabetes mellitus due to a number of risk factors. The earliest recorded treatments for diabetes mellitus involved the use of natural plants. Opuntia species are any member of the genus Opuntia of Cactus family and who are native to the Western Hemisphere. In order to determine the efficacy of Opuntia species as a hypoglycemic agent in non-insulin dependent diabetics, a meta-analysis was conducted to analyze the identified studies. In addition, insulin and the presence of a dose-response relationship upon ingestion of Opuntia were investigated. A statistically significant reduction in serum glucose was found after the ingestion of 500 grams of Opuntia species. Additional studies are needed to determine the mechanism of hypoglycemic action and to further investigate the properties of Opuntia species.Item Quorum Sensing in Sinorhizobium meliloti(2008-12-01) Patankar, Arati V.; Juan E. Gonzales; Jerry W. Simecka; Stephen O. MathewPatankar, Arati V., Quorum Sensing in Sinorhizobium meliloti. Doctor of Philosophy (Microbiology and Immunology), December 2008, 170 pp., 14 tables, 23 illustrations, bibliography, 212 titles. The overall goal of this study was to elucidate the role of a series of transcriptional regulators and potential signal molecules in the coordination of gene regulation in Sinorhizobium meliloti. The agriculturally important gram-negative soil bacterium S. meliloti, forms a symbiotic association with its host legume, Medicago sativa (alfalfa); thereby serving as a good model for studying host-bacterial interactions. Often, bacteria associated with eukaryotic hosts utilize global gene regulatory systems to coordinate their behavior in order to establish pathogenic or symbiotic associations. Quorum sensing is one such form of bacterial gene regulation which is mediated by signaling molecules and regulatory proteins in a population density dependent manner. In S. meliloti, the process of quorum sensing has been shown to play an important role in the relationship with its host plant. Control of essential processes such as plant nodulation and exopolysaccharide production has been attributed to the Sin/ExpR quorum-sensing system of S. meliloti. Interestingly, S. meliloti contains four additional (SMc04032, SMc00658, Smc00878 and SMc00877) putative quorum-sensing response regulators whose regulatory network was not known. The predicted protein sequences of these genes contain features typical of the LuxR family of proteins i.e., an N-terminal signal binding domain and C-terminal helix-turn-helix DNA biding domain. In order to identify their regulatory role, mutants of the response regulators were constructed and their expression profile was determined by employing genome-wide microarray and real-time PCR expression analysis. Through these analyses, it was determined that the SMc004032 locus controls expression of genes involved in the active methyl cycle, while the SMc00658, SMc00878 and SMc00877 loci control expression of genes from the denitrification of pathway of S. meliloti. Further, through phenotypic studies it was established that SMc04032 impacts stress response adaptation, and effective competition for plant nodulation. This suggests that SMc04032 could play a role in bacterial survival in the soil as well as within the host. The ability to denitrify is highly variable in different strains of S. meliloti. Through growth and enzymatic assays, it was established that the wild-type strain of this study, S. meliloti Rm8530, is a partial dentrifier in which, the capacity to metabolize nitrate is impaired. It was further determined that SMc00658, SMc00878 and SMc0877 modulated nitrite reductase activity under aerobic conditions, implying that these genes are involved in aerobic denitrification and therefor probably play a role in detoxification in S. meliloti. Based on the sequenced-genome analysis, S. meliloti possess homologs of other mediators of quorum sensing, that might be responsible for the synthesis of novel signal molecules. Bioreporter strains and mass spectrometry analysis were employed to identify production of cyclic dipeptides in S. meliloti. These compounds have been previously reported as quorum-sensing signal molecules in several bacteria. The results presented in this study provide a better understanding of S. meliloti’s metabolic and physiological properties and will be fundamental in future studies of bacterial interaction with its host and survival within its ecological niche.Item The Effect of CsrA on Biofilm Development in Escherichia coli(2001-05-01) Jackson, Debra White; Julian Borejdo; Richard Easom; Jerry SimeckaJackson, Debra W., The Effect of CsrA on Biofilm Development in Escherichia coli. Doctor of Philosophy (Biomedical Sciences), May 2001, 127 pp., 2 tables, 15 illustrations, bibliography, 138 titles. CsrA, carbon storage regulator, is a small RNA-binding protein that acts as a global regulator and modulates specific mRNA stability in Escherichia coli. CsrA regulates central carbon metabolism in addition to flagella biogenesis. In this study, the phylogenetic distribution of csrA and its role in Escherichia coli biofilm development were examined. CsrA homologs were examined using Southern hybridization experiment and by analyzing existing sequencing data and was found to be widespread among eubacteria. CsrA was shown to be capable of acting as a genetic switch for biofilm formation and dispersal. A csrA mutant of E. coli was shown to increase biofilm formation and exhibit apparent pillars and channels characteristic of a mature biofilm. Over-expression of csrA completely inhibited biofilm formation in E. coli K-12 and decreased biofilm formation in related enteric pathogens. Induction of csrA expression from a multicopy plasmid caused dispersal of a pre-formed biofilm. Gene expression studies revealed that csrA expression is dynamically regulated during biofilm formation. Several outer-membrane factors and global regulators that have been implicated in biofilm formation were examined for effects on biofilm formation in a csrA mutant. Crystal violet adherence assays revealed that flagella and type I pili affect biofilm formation in a scrA mutant strain; however, colonic acid and curli fimbriae did not exhibit quantitative effects on biofilm formation in the csrA mutant, but the stationary phase sigma factor, RpoS, had no quantitative effect on csrA mutant biofilm formation. Therefore, a csrA mutant will form a biofilm in the absence of each of these outer-membrane factors and global regulatory factors of biofilm formation. The effects of csrA on biofilm formation were found to be mediated in part through its effects on intracellular glycogen metabolism. Thus the redirection of carbon flux, in response to environmental and/or physiological cues, is important for biofilm development.Item The Mechanism of Agriculture and Health Exploration of Links Between Agricultural Practice and Human Nutrition in Rural China(2008-05-01) Campos-Bower, Monica Haydee; Nuha Lackan; Robert Kaman; Sejong BaeCampos-Bower, Monica Haydee, The mechanism of agriculture and health-Exploration of links between agricultural practice and human nutrition in rural China Doctor of Public Health (Health Management and Policy), May 2008, 73 pp, 9 Tables, 5 Figures, bibliography, 23 titles. Health consequences of nutritional deficiencies remain a concern for more than half of the global population. Agriculture improvement has helped to alleviate nutritional deficiencies, especially among the rural developing world, where populations are more susceptible. In China, approximately 80% of the population lives in rural areas with close to 40% suffering from at least one nutrient deficiency. Current agricultural development projects in China are geared toward enhancing crop nutrition, but more research is needed to determine the relationship between food practices, agricultural diversity and the nutritional health in rural areas. The purpose of this research was to evaluate the direct relationship of agriculture on human health through assessment of agricultural practices and agricultural policy on human health symptoms in rural populations in China. A comparative study was performed on data from the University of North Carolina Population Center-China Health and Nutrition Survey (CHNS) and a case study based on field research in western China. The study demonstrated relationships between agricultural practices with human health symptoms. In addition, agricultural and environmental policies adopted in rural areas did impact ability to engage in agricultural practices as well as diet and human activity among rural households. Future agricultural and environmental policies should consider repercussions of policy effects on community social infrastructure, economy and health and create measures to address these issues.Item The Role of Advanced Glycation End Products in Brain Aging(2007-10-01) Thangthaeng, Nopporn; Michael J. Forster; Tina MachuThangthaeng, Nopporn, The Role of Advanced Glycation End Products in Brain Aging. Doctor of Philosophy (Biomedical Sciences), October, 2007, 178 pp., 9 tables, 6 figures, bibliography, 213 titles. Glycoxidation is a process of post-translational modification of proteins, involving both glycation and oxidation that ultimately generated advanced glycation end products (AGEs). Glycoxidation, which pay promote oxidative stress and disrupt protein structure and function, is hypothesized to be responsible for pathological conditions related to aging, diabetes, neurodegenerative diseases, and degenerative ophthalmic diseases. Previous studies have demonstrated that AGEs accumulate in the brains of aged animals and humans, yet few studies have directly addressed the possibility that AGEs are a cause of age-related brain dysfunction. Therefore, the overall purpose of the present studies was to examine the role AGEs in normal brain again and the associated decline in cognitive and psychomotor function. In order to achieve the goals, two different approaches were taken. The first approach involved (i) determining whether or not AGEs accumulated in different regions of the brain as a function of age and (ii) determining whether these changes were correlated with individual differences in the ability of old mice to perform in tests of cognitive and psychomotor function. Age-associated accumulation of CML, a predominant form of AGEs in vivo, and expression of receptor for AGEs (RAGE) protein, inferred from densitometry quantification of immunoblots in different regions of the brain, were assessed by comparing groups of 8-or 25-month old mice. The 25-month-old mice were administered a series of behavioral tests to assess cognitive and psychomotor function prior to assessment of glycation status. In the second approach, groups of mature (6 mos) and older mice (18 mos) were fed with a control diet or a diet enriched with galactose (49% of caloric content), an intervention that was expected to promote formation of AGEs. The mice were subsequently tested for impairment of their cognitive and psychomotor functions after 8 weeks on the assigned diet. Upon completion of the behavioral tests (after 14 weeks on diet), amounts of CML and RAGE protein were assessed through densitometric analyses of the immunoblots. The main findings from the first approach were that (i) there was a robust increase in CML content and expression of RAGE protein in the aged mouse brain that occurred in a region-specific manner; (ii) the relative amounts of CML and RAGE were not closely associated with the degree of age-related impairment of mice tested for brain function. The main findings from the second approach were that high dietary galactose: (i) failed to induce aged-like behavioral impairments in young/mature mice; (ii) exacerbated age-related impairment of some psychomotor functions and (iii) had no significant effects on glycation status or oxidative damage. Comparison of the experimental outcomes from the first and second approaches was complicated by a difference in the fat content of the diets fed to the mice in the two studies, which had an apparent effect on the amounts of AGEs and protein oxidation present in young mice. However, considering the results of the two studies independently warrants the following conclusions: (i) Amounts of AGEs do not predict individualized brain aging as assessed by neurobehavioral impairment and may instead by largely reflective of chronological age. (ii) Diets enriched with galactose may produce deleterious effects in older mice that do not involve a change in oxidative damage or glycation status. Overall, these studies provide little support for a specific role of glycoxidation in normal brain aging. It is impossible that the extent of accrual of AGEs in the normally aging brain is insufficient to affect cellular function, whereas larger accumulations of AGEs may be associated with various pathological conditions discussed in the literature.