Nutrition & Food Sciences
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Item Effect of tryptophan catabolites on the development of heat resistance in Bacillus cereus spores(Faculty Press, Cambridge, 1970) Prasad, Chandan; Srinivasan, V.R.Ethyloxamate and nicotinamide inhibited the development of heat resistance and the biosynthesis of pyridine-2,6-dicarboxylic acid (dipicolinic acid) in Bacillus cereus spores. Addition of quinaldic acid or hydroxyanthranilic acid to an ethyloxamate-grown culture resulted in an increase in the number of heat resistant spores. Nicotinamide induced heat sensitivity could be reversed to different degrees by the addition of kynurenine or xanthurenic acid. Explanations which may account for these observations are presented.Item Initiation by methionine of mouse immunoglobulin light chain containing NH-2terminal pyroglutamic acid(Elsevier, 1975) Prasad, Chandan; Peterkofsky, A.The mechanism of biosynthesis of NH2-terminal pyroglutamic acid has been studied in a mouse plasmacytoma (RPC-20) which produces an immunoglobulin light (lambda) chain containing NH2-terminal pyroglutamic acid. To this end, initation of lambda chain synthesis in plasmacytoma cell suspensions has been investigated. The analysis of radioactive lambda chain synthesis by these cells was accomplished with an antibody preparation specific for the precipitation of lambda chain protein from total plasmacytoma protein. NH2-terminal analysis of plasmacytoma cells labeled with [35S]methionine showed that the ratio of radioactivity in NH2-terminal methionine to total incorporation in lambda chain was greater at 2 min of labeling than at 60 min. However, such a pattern of transient labeling of the NH2 terminus of the lambda chain was not obtained when cells were incubated with tritiated leucine, arginine, or tryptophan. The data indicate that methionine is the initiator amino acid for the synthesis of lambda chain containing NH2-terminal pyroglutamic acid.Item Involvement of the glucose enzymes II of the sugar phosphotransferase system in the regulation of adenylate cyclase by glucose in escherichia coli(Elsevier, 1976) Harwood, J.P.; Gazdar, C.; Prasad, Chandan; Peterkofsky, A.; Curtis, S.J.; Epstein, W.The nature of the interaction of glucose with toluene-treated cells of Escherichia coli leading to inhibition of adenylate cyclase was examined by the use of analogues. Those analogues with variations of the substituents about carbon atoms 1 or 2 (e.g. alpha-methylglucoside or 2-deoxyglucose) are inhibitory, and they are also substrates of the phosphoenolpyruvate-dependent sugar phosphotransferase system. Analogues with changes in other parts of the molecule (e.g. 3-O-methylglucose or galactose), L-glucose and several disaccharides and pentoses, do not inhibit adenylate cyclase and are not substrates of the phosphotransferase system. This correlation suggests some functional relationship between the adenylate cyclase and phosphotransferase systems. Further studies were done with mutants defective in glucose enzymes II of the phosphotransferase system (designated GPT and MPT); these two activities are measured by phosphorylation of alpha-methyl-glucoside and 2-deoxyglucose, respectively. The wild-type parent phosphorylates both analogues, and both inhibit adenylate cyclase. In the GPT- mutant, alpha-methylglucoside does not inhibit adenylate cyclase and is not phosphorylated, while 2-deoxyglucose is inhibitory and phosphorylated. In the GPT- MPT- double mutant, adenylate cyclase activity is present, but neither alpha-methylglucoside nor 2-deoxyglucose inhibits adenylate cyclase, and neither sugar is phosphorylated. These studies demonstrate that glucose inhibition of adenylate cyclase in toluene-treated cells requires an interaction of this sugar with either the GPT or mpt enzyme II of the phosphotransferase system.Item Demonstration of pyroglutamylpeptidase and amidase activities toward thyrotropin-releasing hormone in hamster hypothalamus extracts(Elsevier, 1976) Prasad, Chandan; Peterkofsky, A.Using a radioimmunoassay method for thyrotropin-releasing hormone, the presence of thyrotropin-releasing hormone-metabolizing activity in various hamster tissues was demonstrated. While there was substantial activity degrading thyrotropin-releasing hormone in hypothalamus, there was a notable absence of such activity in pituitary. The enzymatic activity in the hypothalamus was shown to be soluble and separable into two fractions. Analysis of the metabolic products formed by the two enzymes indicated that one possessed an amidase activity (less than Glu-His-Pro-NH2 leads to less than Glu-His-Pro) and the other possessed pyroglutamylpeptidase activity (less than Glu-His-Pro-NH2 leads to less than Glu+His-Pro-NH2). Other peptides containing NH2-terminal pyroglutamic acid or COOH-terminal amide groups did not block the hydrolysis of thyrotropin-releasing hormone, suggesting that the enzymes were specific. Some inhibitors preferentially blocked the activity of one or the other enzymes. Of possible biological significance is the observation that thyroid-stimulating hormone inhibited the amidase activity while hydrocortisone inhibited the pyroglutamylpeptidase activity.Item Metabolism of thyrotropin releasing hormone in brain extracts. isolation and characterization of an imidopeptidase for histidylprolineamide(Elsevier, 1979) Matsui, T.; Prasad, C.; Peterkofsky, A.An extract of porcine brain acetone powder incubated with thyrotropin-releasing hormone (TRH; pGlu-His-ProNH2) produces acid TRH (pGlu-His-Pro), histidine, and prolineamide. Fractionation of the brain extract by DEAE-cellulose chromatography produces three protein fractions which metabolize TRH. The activity of these fractions was characterized using TRH with a 3H-label on the histidine or proline as well as [His-3H]His-ProNH2. Fraction I contains pyroglutamate aminopeptidase and Fraction II contains TRH deamidase. Fraction III was found to contain a previously unrecognized enzyme which cleaves His-ProNH2 to histidine and proline. The histidylprolineamide imidopeptidase has been characterized. A competition study using a variety of compounds containing histidine or proline suggests that the best substrates for the imidopeptidase contain a free alpha-amino group on histidine and a blocked carboxyl group on proline, as is found in His-ProNH2. A survey of a variety of polypeptide hormones indicates that many of them inhibit the imidopeptidase activity. A kinetic study of the inhibition of the enzyme by adrenocorticotropic hormone (1-24) shows that the inhibition by polypeptide hormones is noncompetitive. We hypothesize that pituitary hormones may stimulate the production of (cyclo)-His-Pro by inhibiting alternate routes of TRH metabolism.Item The subcellular and organ distribution and natural form of histidyl-proline diketopiperazine in rat brain determined by a specific radioimmunoassay(Elsevier, 1980) Yanagisawa, T.; Prasad, Chandan; Peterkofsky, A.Histidyl-proline diketopiperazine is produced in brain as a product of the metabolism of thyrotropin-releasing hormone. A number of the previously observed central nervous system and pituitary activities resulting from an exposure to thyrotropin-releasing hormone appear to involve the conversion of the releasing factor to the cyclic dipeptide. In the present study, the development of a rabbit antiserum that is highly specific for histidyl-proline diketopiperazine is described; the antiserum has essentially no capability to bind thyrotropin-releasing hormone or a number of other related peptides. The antibody can also distinguish between the natural form of the cyclic dipeptide and a diastereomer containing D-proline. A procedure for extraction, with high yield, of histidyl-proline diketopiperazine from brain is described. With the aid of the specific antiserum it was found that the preponderance of the cyclic dipeptide in rat brain is bound to high molecular weight material, mainly in the range of Mr = 70,000; histidyl-proline diketopiperazine can be disassociated from this material by boiling in salt/methanol solution. The concentration of the dipeptide in rat brain is in the range of 275 to 565 pmol/brain, approximately 2.5 times the concentrations determined for thyrotropin-releasing hormone (113 to 210 pmol/brain). A study of the subcellular distribution of histidyl-proline diketopiperazine and thyrotropin-releasing hormone suggests that the releasing factor is concentrated in synaptosomal vesicles while the diketopiperazine is not. A determination of the regional distribution of thyrotropin-releasing hormone and histidyl-proline diketopiperazine indicated that both peptides are found in highest concentrations in pituitary and hypothalamus, but are detectable in other areas of brain as well.Item Synthesis of phosphatidylcholine from phosphatidylethanolamine by at least two methyltransferases in rat pituitary extracts(Elsevier, 1981) Prasad, Chandan; Edwards, R.M.Rat pituitary extracts contain at least two methyltransferases that methylate phosphatidylethanolamine to phosphatidylcholine using S-adenosylmethionine as the methyl donor. The first enzyme methylates phosphatidylethanolamine to phosphatidyl-N-monomethylethanolamine and has a high Km (40-42 microM) for S-adenosylmethionine, whereas the second enzyme(s) catalyzes two successive methylations of phosphatidyl-N-monomethylethanolamine to phosphatidyl-N,N-dimethylethanolamine and then to phosphatidylcholine and has a low Km (6.7 microM) for S-adenyl-L-methionine. The first enzyme is loosely bound to the membrane fraction; therefore it appears in both particulate (20,000 X g) and supernatant (20,000 X g) fractions, whereas the second enzyme(s) is tightly bound to the membrane and thus appears only in the particulate fraction. Both methyltransferases have two pH optima of 6.5 and 9.5 (9.5 activity greater than 6.5 activity) and they do not require Mg2+.Item Impact of dysphagia on nutritional status in amyotrophic lateral sclerosis(1995-08) Calvin, SandraItem Food, mood and health: A neurobiologic outlook(Associação Brasileira de Divulgação Científica (ABDC), 1998) Prasad, ChandanHippocrates was the first to suggest the healing power of food; however, it was not until the medieval ages that food was considered a tool to modify temperament and mood, although scientific methods as we know them today were not in use at the time. Modern scientific methods in neuroscience began to emerge much later, leading investigators to examine the role of diet in health, including mental well-being, with greater precision. This review shows how short- and long-term forced dietary interventions bring about changes in brain structure, chemistry, and physiology, leading to altered animal behavior. Examples will be presented to show how diets alter brain chemistry, behavior, and the action of neuroactive drugs. Most humans and most animal species examined in a controlled setting exhibit a fairly reproducible pattern of what and how they eat. Recent data suggest that these patterns may be under the neurochemical and hormonal control of the organisms themselves. Other data show that in many instances food may be used unconsciously to regulate mood by seemingly normal subjects as well as those undergoing drug withdrawal or experiencing seasonal affective disorders and obesity-related social withdrawal. We will discuss specific examples that illustrate that manipulation of dietary preference is actually an attempt to correct neurochemical make-up.Item Sensory characteristics of high‐amylose maize‐resistant starch in three food products(Wiley, 2012) Maziarz, Mindy; Sherrard, Melanie; Juma, Shanil; Prasad, Chandan; Imrhan, Victorine; Vijayagopal, ParakatType 2 resistant starch from high-amylose maize (HAM-RS2) is considered a functional ingredient due to its positive organoleptic and physiochemical modifications associated with food and physiological benefits related to human health. The sensory characteristics of three types of food products (muffins, focaccia bread, and chicken curry) with and without HAM-RS2 were evaluated using a 9-point hedonic scale. The HAM-RS2-enriched muffins, focaccia bread, and chicken curry contained 5.50 g/100 g, 13.10 g/100 g, and 8.94 g/100 g RS, respectively, based on lyophilized dry weight. The HAM-RS2-enriched muffin had higher moisture content and was perceived as being significantly moister than the control according to the sensory evaluation. The addition of HAM-RS2 to muffins significantly enhanced all sensory characteristics and resulted in a higher mean overall likeability score. The HAM-RS2-enriched focaccia bread appeared significantly darker in color, was more dense, and had the perception of a well-done crust versus the control. A grainer texture was observed with the chicken curry containing HAM-RS2 which did not significantly affect overall likeability. We concluded that the addition of HAM-RS2 may not significantly alter consumer's acceptability in most food products.Item Consumption of a diet rich in cottonseed oil (CSO) lowers total and LDL cholesterol in NORMO-cholesterolemic subjects(MDPI, 2012) Davis, Kathleen E.; Prasad, Chandan; Imrhan, VictorineAnimal data indicates that dietary cottonseed oil (CSO) may lower cholesterol; however, the effects of a CSO-rich diet have not been evaluated in humans. Thirty-eight healthy adults (aged 18%#x2013;40; 12 males, 26 females) consumed a CSO rich diet (95 g CSO daily) for one week. Anthropometric measurements were obtained, and blood was drawn pre- and post-intervention. Serum lipids (total cholesterol (TC), high density lipoprotein (HDL), low density lipoprotein (LDL), triglyceride (TG), and free fatty acids (FFA)) were assayed. There was no change in weight or waist circumference among participants. There was no change in HDL (Pre: 1.27 ± 0.4 mmol/L; Post: 1.21 ± 0.3 mmol/L) or TG (Pre: 0.91 ± 0.6 mmol/L; Post: 1.06 ± 1.0 mmol/L). Total cholesterol and LDL were reduced (TC Pre: 4.39 ± 0.9 mmol/L; Post: 4.16 ± 0.8 mmol/L; LDL Pre: 2.70 ± 0.8 mmol/L; Post: 2.47 ± 0.6 mmol/L). When data were grouped by sex, total cholesterol was reduced in female participants (Pre: 4.34 ± 0.9 mmol/L; Post: 4.09 ± 0.8 mmol/L). Consumption of a high fat, CSO-rich diet for one week reduced total cholesterol in female participants without reducing HDL.Item Lifestyle and advanced glycation end products (AGEs) burden: Its relevance to healthy aging(Aging and Disease Editorial, 2014) Prasad, Chandan; Imrhan, Victorine; Marotta, Francesco; Juma, Shanil; Vijayagopal, ParakatUncontrolled continued exposure to oxidative stress is a precursor to many chronic diseases including cancer, diabetes, degenerative disorders and cardiovascular diseases. Of the many known mediators of oxidative stress, reactive oxygen species (ROS) and advanced glycation end products (AGEs) are the most studied. In the present review, we have summarized current data on the origin of circulating AGEs, discussed issues associated with reliable assessment of its steady state level, and changes in its level with age and select metabolic diseases. Lastly, we have made recommendations about life style changes that may decrease AGEs burden to promote healthy aging.Item Grape consumption improves joint flexibility and reduces pain associated with knee osteoarthritis(2014-12-30) Tiernan, Casey; Juma, Shanil; Imrhan, Victorine; Vijayagopal, Parakat; Prasad, Chandan; Kwon, Young-HooOsteoarthritis (OA) is the most common disease of joints, with a complex etiology. Pain and stiffness lead to loss of mobility that often requires invasive therapies. A growing interest in natural treatments suggests a role in OA therapy for foods with bioactive compounds. Grape polyphenols have anti-inflammatory properties that may influence OA outcomes. The purpose of this study was to assess the effect of grape consumption on self-reported pain, joint range-of-motion (ROM) and biochemical markers of inflammation (C-reactive protein [CRP]) and cartilage metabolism (insulinlike growth factor-1 [IGF-1], human cartilage glycoprotein 30 [YKL-40]) in individuals with self-reported knee OA. Using convenience sampling, 72 men and women with knee OA were recruited through local orthopedic clinics, primary care physicians, a senior recreation facility, the Texas Woman’s University campus, and other locations in the community. The treatment group (n =35, 27 female) consumed 47 g of freeze-dried grape powder (FDGP) daily for four months. The placebo group (n = 37, 28 female) consumed a comparable placebo. The FDGP group had a significant decrease in pain related to activity from baseline to end of treatment in comparison to placebo (-5.3 vs. - 2.1, p <0 .05). At midpoint, both groups had a significant reduction in total knee symptoms and impact on quality of life (QOL) that was only evident in the FDGP group at the end of study. Furthermore, this improvement benefitted female participants more so than males. FDGP consumption resulted in gender specific changes in IGF-1 compared to the placebo group. Males in the FDGP group had a significant increase in IGF-1 from baseline compared to males in the placebo group (1.6 and 19.9 ng/mL in FDGP; 6.8 and 2.0 ng/mL in placebo for baseline and final, respectively), and females in both FDGP and placebo group (5.1 and 3.2 ng/mL FDGP; 4.9 and 8.9 ng/mL placebo for female baseline and final, respectively), p <0.05). There was no change in overall ROM, CRP, or YKL-40 between FDGP and placebo groups. These results suggest consumption of whole grapes with their bioactive constituents may be a natural alternative to reducing pain and improving symptoms associated with OA.Item Bioactive plant metabolites in the management of non-communicable metabolic diseases: Looking at opportunities beyond the horizon(MDPI, 2015) Prasad, Chandan; Imrhan, Victorine; Juma, Shanil; Maziarz, Mindy; Prasad, Anand; Tiernan, Casey; Vijayagopal, ParakatThere has been an unprecedented worldwide rise in non-communicable metabolic diseases (NCDs), particularly cardiovascular diseases (CVD) and diabetes. While modern pharmacotherapy has decreased the mortality in the existing population, it has failed to stem the rise. Furthermore, a large segment of the world population cannot afford expensive pharmacotherapy. Therefore, there is an urgent need for inexpensive preventive measures to control the rise in CVD and diabetes and associated co-morbidities. The purpose of this review is to explore the role of food bioactives in prevention of NCDs. To this end, we have critically analyzed the possible utility of three classes of food bioactives: (a) resistant starch, a metabolically resistant carbohydrate known to favorably modulate insulin secretion and glucose metabolism; (b) cyclo (His-Pro), a food-derived cyclic dipeptides; and (c) polyphenol-rich berries. Finally, we have also briefly outlined the strategies needed to prepare these food-bioactives for human use.Item The walking interventions through texting (WalkIT) trial: Rationale, design, and protocol for a factorial randomized controlled trial of adaptive interventions for overweight and obese, inactive adults(JMIR Publications, 2015) Hurley, Jane C.; Hollingshead, Kevin E.; Todd, Michael; Jarrett, Catherine L.; Tucker, Wesley J.; Angadi, Siddhartha S.Background:: Walking is a widely accepted and frequently targeted health promotion approach to increase physical activity (PA). Interventions to increase PA have produced only small improvements. Stronger and more potent behavioral intervention components are needed to increase time spent in PA, improve cardiometabolic risk markers, and optimize health.Item Validity and reliability of Nike + Fuelband for estimating physical activity energy expenditure(BMC, 2015) Tucker, Wesley J.; Bhammar, Dharini M.; Sawyer, Brandon J.; Buman, Matthew P.; Gaesser, Glenn A.Background: The Nike + Fuelband is a commercially available, wrist-worn accelerometer used to track physical activity energy expenditure (PAEE) during exercise. However, validation studies assessing the accuracy of this device for estimating PAEE are lacking. Therefore, this study examined the validity and reliability of the Nike + Fuelband for estimating PAEE during physical activity in young adults. Secondarily, we compared PAEE estimation of the Nike + Fuelband with the previously validated SenseWear Armband (SWA).Item Tart cherry in amelioration of pain in the elderly(IOS Press, 2015) Tiernan, Casey; Imrhan, Victorine; Prasad, Chandan; Vijayagopal, Parakat; Juma, ShanilBackground: Tart cherry, rich in bioactive polyphenols, has received attention in the past decade for reported health benefits due to its high polyphenolic content.Item Contribution of dietary advanced glycation end products (AGE) to circulating AGE: Role of dietary fat(Cambridge University Press, 2015-09-22) Davis, Kathleen Elizabeth; Prasad, Chandan; Vijayagopal, Parakat; Juma, Shanil; Adams-Huet, Beverley; Imrhan, VictorineThe purpose of this pilot study was to determine whether macronutrient content (low-fat v. high-fat diet) influences an indicator of advanced glycation end products (AGE), N ε carboxymethyl-lysine (CML), in the context of a 1-d, high-AGE diet. The effect of the diets on inflammatory markers was also assessed. A total of nineteen overweight and obese adults (nine men and ten women) without known disease were recruited to participate in a crossover challenge of a high-fat, high-AGE (HFHA) and low-fat, high-AGE (LFHA) diet. In each phase patients had fasting blood drawn, followed by consumption of a high-fat or low-fat breakfast test meal, then three postprandial blood draws at 1, 2 and 3 h after consuming the test meal. After consuming high-AGE meals for the remainder of the day, participants returned the next day for a follow-up analysis. A different pattern in the 3-h post-meal CML and soluble receptor for AGE response to the two diets was observed (P = 0·01 and 0·05, respectively). No change in serum CML was observed following consumption of a LFHA breakfast (535 (25th–75th percentile 451–790) to 495 (25th–75th percentile 391–682) ng/ml; P = 0·36), whereas a rise in CML occurred after the HFHA breakfast (463 (25th–75th percentile 428–664) to 578 (25th–75th percentile 474–865) ng/ml; P = 0·05). High sensitivity C-reactive protein and high molecular weight adiponectin were not affected by either diet. These findings suggest that dietary CML may not be as important in influencing serum CML as other dietary factors. In addition, acute exposure to dietary CML may not influence inflammation in adults without diabetes or kidney disease. This is contrary to previous findings.Item Impact of exercise training on peak oxygen uptake and its determinants in heart failure with preserved ejection fraction(Lippincott, 2016) Tucker, Wesley J.; Nelson, Michael D.; Beaudry, Rhys I.; Halle, Martin; Sarma, Satyam; Kitzman, Dalane W.; La Gerche, Andre; Haykowsky, Mark J.Heart failure with preserved ejection (HFpEF) accounts for over 50 % of all HF cases, and the proportion is higher among women and older individuals. A hallmark feature of HFpEF is dyspnoea on exertion and reduced peak aerobic power (VO2peak) secondary to central and peripheral abnormalities that result in reduced oxygen delivery to and/or utilisation by exercising skeletal muscle. The purpose of this brief review is to discuss the role of exercise training to improve VO2peak and the central and peripheral adaptations that reduce symptoms following physical conditioning in patients with HFpEF.Item Association between serum uric acid and metabolic syndrome components in prepubertal obese children (tanner stage I) from Nuevo León, Mexico - A preliminary study(BMC, 2017) Solis Perez, Elizabeth; González Medina, Mario Alberto; Lomeli, Manuel Lopez-Cabanillas; González, Verónica Tijerina; Pérez, Jesús Zacarías Villarreal; González, Fernando J. Lavalle; Imrhan, Victorine; Juma, Shanil; Vijayagopal, Parakat; Boonme, Kittipong; Prasad, ChandanBackground: Metabolic syndrome (MetS) is a major risk factor for cardiovascular disease and diabetes. Previous studies in obese children demonstrating a positive association between serum uric acid (sUA) and components of MetS are confounded by lack of uniformity in age and pubertal status of children. Therefore, we have examined the role of sUA in MetS and its components in pre-pubertal children (Tanner Stage I, age ≤ 9 years).