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Elayoubi FA, Fraser A, Jenkins DJ, Craig PS. Partial characterisation of carbohydrate-rich Echinococcus granulosus coproantigens. Int J Parasitol 2003; 33:1553-9. [PMID: 14572518 DOI: 10.1016/s0020-7519(03)00198-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Coproantigen ELISA based tests for diagnosis of canine echinococcosis provide high specificity and sensitivity. However, the antigenic molecules present in faeces from infected dogs have not yet been characterised. While initial attempts to determine the molecular weights of Echinococcus granulosus coproantigens by SDS-PAGE and Western blotting with coproantigen reactive capture antibodies were equivocal, they suggested presence of a significant carbohydrate component. Periodate treatment of coproantigen positive faecal supernatants resulted in a significant reduction (53%) in ELISA activity, suggesting that carbohydrates are involved in the antigenic structure of E. granulosus coproantigens. Protease treatment of antigenic molecules resulted in an 11% reduction in absorbance in ELISA, indicating that protein components were also present which affected by enzyme activity. Lectin-binding ELISA assays indicated strong affinity of E. granulosus coproantigens to concanavalin agglutinin and Lens culinaris agglutinin, and moderate binding to wheat-germ agglutinin and peanut agglutinin. No binding was detectable to Ulex europaensis agglutinin-I, Bandeiraea simplicifolia or Dolichos biflorus agglutinin. These data indicate that E. granulosus coproantigens from infected dog faeces possibly contained alpha-D-mannose and/or alpha-D-glucose, beta-galactose and N-acetyl-beta-glucosamine residues. To verify the role of carbohydrate moieties in coproantigens, faecal samples were treated with exoglycosidase and tested in the coproantigen ELISA. Treatment with beta-galactosidase or N-acetyl-beta-glucosamine reduced ELISA activity by 44 and 30%, respectively. Incubation with a panel of other specific exoglycosidases including alpha-galactosidase as well as alpha-L-fucosidase, alpha-mannosidase, beta-mannosidase, alpha-glucosidase, beta-glucosidase, beta- fructosidase, or neuraminidase, did not alter coproantigen detection in ELISA. The results indicate that coproantigens present in faeces from E. granulosus naturally infected dogs were highly glycosylated and contain beta- galactose and N-acetyl-beta-glucosamine. The putative relationship of antigenic molecules with the tapeworm glycocalyx is discussed.
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Attard GA, Ahmadi A, Jenkins DJ, Hazzazi OA, Wells PB, Griffin KG, Johnston P, Gillies JE. The characterisation of supported platinum nanoparticles on carbon used for enantioselective hydrogenation: a combined electrochemical-STM approach. Chemphyschem 2003; 4:123-30. [PMID: 12619410 DOI: 10.1002/cphc.200390021] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The action of chiral modifiers like cinchonine and cinchonidine in facilitating enationselectivity in heterogeneous catalysis is investigated using a combination of electrochemical and scanning probe methods. The surface chirality of corner kink sites is suggested as being crucial for chirality recognition at supported catalyst nanoparticles. Other aspects of chirality in relation to one, two, three and four dimensions are also discussed.
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Burch R, Attard GA, Daniells ST, Jenkins DJ, Breen JP, Hu P. Low-temperature catalytic decomposition of N2O on platinum and bismuth-modified platinum: identification of active sites. Chem Commun (Camb) 2002:2738-9. [PMID: 12510325 DOI: 10.1039/b208006k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Classification of the active surface sites of platinum catalysts responsible for low temperature N2O decomposition, in terms of steps, kinks and terraces, has been achieved by controlled addition of bismuth to as-received platinum/graphite catalysts.
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Riley AM, Jenkins DJ, Marwood RD, Potter BVL. Synthesis of glucopyranoside-based ligands for D-myo-inositol 1,4,5-trisphosphate receptors. Carbohydr Res 2002; 337:1067-82. [PMID: 12062522 DOI: 10.1016/s0008-6215(02)00103-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Adenophostins A and B are naturally occurring glyconucleotides that interact potently with receptors for D-myo-inositol 1,4,5-trisphosphate, an important second messenger molecule in most cell types. Here we describe the design and synthesis of glucopyranoside-based analogues of adenophostin A lacking the adenine component. The key synthetic strategy involves glycosylation of selectively protected alcohols, derived from methyl beta-D-ribofuranoside or 1,4-anhydroerythritol, using glycosyl donors synthesised from 2,6-di-O-benzyl-D-glucopyranose derivatives. Further elaboration and deprotection of the coupled products gave two trisphosphate analogues; methyl 3-O-alpha-D-glucopyranosyl-beta-D-ribofuranoside 2,3',4'-trisphosphate ("ribophostin") and (3'S,4'R)-3'-hydroxytetrahydrofuran-4'-yl alpha-D-glucopyranoside 3,4,3'-trisphosphosphate ("furanophostin"). The route to furanophostin was further modified to give (3'S,4'R)-3'-hydroxytetrahydrofuran-4'-yl alpha-D-glucopyranoside 3'-phosphate 3,4-bisphosphorothioate, the first phosphorothioate-containing adenophostin analogue.
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Riley AM, Jenkins DJ, Potter BVL. Pentagon IP3: Synthesis of a Ring-Contracted Mimic of a Second Messenger. J Am Chem Soc 2002. [DOI: 10.1021/ja00116a046] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Augustin LS, Dal Maso L, La Vecchia C, Parpinel M, Negri E, Vaccarella S, Kendall CW, Jenkins DJ, Francesch S. Dietary glycemic index and glycemic load, and breast cancer risk: a case-control study. Ann Oncol 2001; 12:1533-8. [PMID: 11822751 DOI: 10.1023/a:1013176129380] [Citation(s) in RCA: 149] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Certain types of carbohydrates increase glucose and insulin levels to a greater extent than others. In turn, insulin may raise levels of insulin-like growth factors, which may influence breast cancer risk. We analyzed the effect of type and amount of carbohydrates on breast cancer risk, using the glycemic index and the glycemic load measures in a large case-control study conducted in Italy. PATIENTS AND METHODS Cases were 2,569 women with incident, histologically-confirmed breast cancer interviewed between 1991 and 1994. Controls were 2588 women admitted to the same hospital network for a variety of acute, non-neoplastic conditions. Average daily glycemic index and glycemic load were calculated from a validated 78-item food frequency questionnaire. RESULTS Direct associations with breast cancer risk emerged for glycemic index (odds ratio, OR for highest vs. lowest quintile = 1.4; P for trend <0.01) and glycemic load (OR = 1.3; P < 0.01). High glycemic index foods, such as white bread, increased the risk of breast cancer (OR = 1.3) while the intake of pasta, a medium glycemic index food, seemed to have no influence (OR = 1.0). Findings were consistent across different strata of menopausal status, alcohol intake, and physical activity level. CONCLUSIONS This study supports the hypothesis of moderate, direct associations between glycemic index or glycemic load and breast cancer risk and, consequently, a possible role of hyperinsulinemia/insulin resistance in breast cancer development.
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Rosenberg Zand RS, Jenkins DJ, Diamandis EP. Effects of natural products and nutraceuticals on steroid hormone-regulated gene expression. Clin Chim Acta 2001; 312:213-9. [PMID: 11580929 DOI: 10.1016/s0009-8981(01)00626-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND There is an increasing trend in the use of complementary and alternative therapies to treat or prevent hormonally dependent pathologies. Methods determined whether several of these natural products and nutraceuticals, commonly taken for hormone-related effects, possess steroid hormone activity. The agonist and antagonist estrogenic, androgenic, and progestational activities of 20 natural products and nutraceuticals were assessed using an in vitro tissue culture indicator system. Two steroid-regulated proteins (pS2 and prostate-specific antigen [PSA]) were quantified, using ELISA-type immunoassays, as markers of agonist and antagonist activity. RESULTS Four of the products tested, two isoflavone preparations, Promensil and Estro-Logic, chamomile, and grapeseed extracts, were found to have weak estrogenic agonist activity, with the latter two also demonstrating weak progestational activity. Several of the products tested exhibited antagonistic (blocking) activity, including antiestrogenic activity by Prostate-Ease, wild yam root, and dong quai, and antiandrogenic activity by dong quai, Promensil, and rosehips. CONCLUSIONS Several of these natural products demonstrate weak steroid hormone activity.
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Jenkins DJ, Kendall CW, Vidgen E, Augustin LS, van Erk M, Geelen A, Parker T, Faulkner D, Vuksan V, Josse RG, Leiter LA, Connelly PW. High-protein diets in hyperlipidemia: effect of wheat gluten on serum lipids, uric acid, and renal function. Am J Clin Nutr 2001; 74:57-63. [PMID: 11451718 DOI: 10.1093/ajcn/74.1.57] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND The metabolic effects of diets high in vegetable protein have not been assessed despite much recent interest in the effect of soy proteins in reducing serum cholesterol. OBJECTIVE We assessed the metabolic effects of diets high in vegetable protein (specifically, wheat gluten) on serum lipids, uric acid concentrations, and renal function. DESIGN Twenty hyperlipidemic men and women consumed isoenergetic test (high-protein) and control metabolic diets for 1 mo in a randomized crossover design. In the high-protein diet, 11% of the total dietary energy from starch in the control bread was replaced by vegetable protein (wheat gluten), resulting in 27% of total energy from protein compared with 16% in the control diet. In other respects, the 2 diets were identical. RESULTS Compared with the control, the high-protein diet resulted in lower serum concentrations of triacylglycerol (by 19.2 +/- 5.6%; P = 0.003), uric acid (by 12.7 +/- 2.0%; P < 0.001), and creatinine (by 2.5 +/- 1.1%; P = 0.035) and higher serum concentrations of urea (by 42.2 +/- 5.8%; P < 0.001) and a higher 24-h urinary urea output (by 99.2 +/- 17.2%; P < 0.001). No significant differences were detected in total or HDL cholesterol or in the renal clearance of creatinine. LDL oxidation, assessed as the ratio of conjugated dienes to LDL cholesterol in the LDL fraction, was lower with the high-protein diet (by 10.6 +/- 3.6%; P = 0.009). CONCLUSIONS High intakes of vegetable protein from gluten may have beneficial effects on cardiovascular disease risk by reducing oxidized LDL, serum triacylglycerol, and uric acid. Further studies are required to assess the longer-term effects on renal function.
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Cunnane SC, Ross R, Bannister JL, Jenkins DJ. Beta-oxidation of linoleate in obese men undergoing weight loss. Am J Clin Nutr 2001; 73:709-14. [PMID: 11273844 DOI: 10.1093/ajcn/73.4.709] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND In animals, the whole-body content and accumulation of linoleate can be measured and compared with its intake to determine linoleate beta-oxidation. This method can also provide quantitative information about the beta-oxidation of linoleate in humans. OBJECTIVES The objectives of the study were to 1) use the wholebody fatty acid balance method to quantify whole-body concentrations of linoleate in humans, 2) estimate the distribution of linoleate between adipose and lean tissue, and 3) assess the effect of weight loss on linoleate stores and beta-oxidation in obese humans. DESIGN Nine healthy obese men underwent supervised weight loss for 112 d (16 wk). Magnetic resonance imaging data and fatty acid profiles from fat biopsies were both used to determine linoleate stores in adipose and lean tissue and in the whole body. Linoleate beta-oxidation was calculated as intake - (accumulation + excretion). RESULTS Mean weight loss was 13 kg and linoleate intake was 24 +/- 6 mmol/d over the study period. Whole-body loss of linoleate was 37 +/- 18 mmol/d, or 28% of the level before weight loss. Combining the intake and whole-body loss of linoleate resulted in linoleate beta-oxidation exceeding intake by 2.5-fold during the weight-loss period. CONCLUSIONS All dietary linoleate is beta-oxidized and at least an equivalent amount of linoleate is lost from the body during moderate weight loss in obese men. The method studied permits the assessment of long-term changes in linoleate homeostasis in obese humans and may be useful in determining the risk of linoleate deficiency in other conditions.
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Jenkins DJ, Kendall CW, Popovich DG, Vidgen E, Mehling CC, Vuksan V, Ransom TP, Rao AV, Rosenberg-Zand R, Tariq N, Corey P, Jones PJ, Raeini M, Story JA, Furumoto EJ, Illingworth DR, Pappu AS, Connelly PW. Effect of a very-high-fiber vegetable, fruit, and nut diet on serum lipids and colonic function. Metabolism 2001; 50:494-503. [PMID: 11288049 DOI: 10.1053/meta.2001.21037] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We tested the effects of feeding a diet very high in fiber from fruit and vegetables. The levels fed were those, which had originally inspired the dietary fiber hypothesis related to colon cancer and heart disease prevention and also may have been eaten early in human evolution. Ten healthy volunteers each took 3 metabolic diets of 2 weeks duration. The diets were: high-vegetable, fruit, and nut (very-high-fiber, 55 g/1,000 kcal); starch-based containing cereals and legumes (early agricultural diet); or low-fat (contemporary therapeutic diet). All diets were intended to be weight-maintaining (mean intake, 2,577 kcal/d). Compared with the starch-based and low-fat diets, the high-fiber vegetable diet resulted in the largest reduction in low-density lipoprotein (LDL) cholesterol (33% +/- 4%, P <.001) and the greatest fecal bile acid output (1.13 +/- 0.30 g/d, P =.002), fecal bulk (906 +/- 130 g/d, P <.001), and fecal short-chain fatty acid outputs (78 +/- 13 mmol/d, P <.001). Nevertheless, due to the increase in fecal bulk, the actual concentrations of fecal bile acids were lowest on the vegetable diet (1.2 mg/g wet weight, P =.002). Maximum lipid reductions occurred within 1 week. Urinary mevalonic acid excretion increased (P =.036) on the high-vegetable diet reflecting large fecal steroid losses. We conclude that very high-vegetable fiber intakes reduce risk factors for cardiovascular disease and possibly colon cancer. Vegetable and fruit fibers therefore warrant further detailed investigation.
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Sievenpiper JL, Jenkins DJ, Josse RG, Leiter LA, Vuksan V. Simple skinfold-thickness measurements complement conventional anthropometric assessments in predicting glucose tolerance. Am J Clin Nutr 2001; 73:567-73. [PMID: 11237933 DOI: 10.1093/ajcn/73.3.567] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Skinfold-thickness measurements are considered to have limited clinical utility. OBJECTIVE To assess whether skinfold-thickness measurements may be a useful adjunct to conventional anthropometric assessments in predicting glucose and insulin regulation, we studied responses to replicate 75-g oral-glucose-tolerance tests (OGTTs) and performed simple anthropometry in a cross section of subjects. DESIGN Thirty-five subjects completed the study: 11 lean [mean (+/-SEM) age: 33 +/- 3.2 y; body mass index (BMI; in kg/m(2)): 24.1 +/- 0.8; and percentage body fat (%BF): 11.5 +/- 1.5%], 12 normal-weight (age: 33 +/- 2.9 y; BMI: 23.9 +/- 0.7; and %BF: 24.3.5 +/- 1.3%), and 12 obese (age: 41 +/- 4.5 y; BMI: 34.5 +/- 1.7; and %BF: 34.2 +/- 1.5%) individuals. The lean and normal-weight groups were selected to have similar BMIs but different %BFs. We measured the participants' heights, weights, %BFs, waist circumferences, hip circumferences, and truncal and peripheral skinfold thicknesses. Subjects received nine 75-g OGTTs and blood samples were collected at 0, 15, 30, 45, 60, 90, and 120 min. Mean plasma glucose and insulin values were used to calculate the insulin sensitivity index. RESULTS The obese group had higher plasma glucose concentrations and areas under the curve (AUCs) than did the normal-weight or lean group and higher plasma insulin concentrations and AUCs than did the lean group (P < 0.05). Stepwise multiple regression, with adjustment for demographic and anthropometric measurements, identified the following predictors: waist circumference, peripheral skinfold thickness, and BMI for fasting plasma glucose (partial R(2) = 0.20, 0.13, and 0.13, P < 0.05); waist circumference and truncal skinfold thickness for plasma glucose AUC (partial R(2) = 0.20 and 0.13, P < 0.05); age, waist-to-hip ratio, and peripheral skinfold thickness for fasting plasma insulin (partial R(2) = 0.26, 0.22, and 0.15, P < 0.05); truncal skinfold thickness for plasma insulin AUC (partial R(2) = 0.41, P < 0.001); and peripheral skinfold thickness for both 2-h plasma glucose (partial R(2) = 0.59, P < 0.001) and the insulin sensitivity index (partial R(2) = 0.49, P < 0.001). CONCLUSION Skinfold-thickness measurements may complement other established measurements for predicting abnormal glucose and insulin regulation.
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Franceschi S, Dal Maso L, Augustin L, Negri E, Parpinel M, Boyle P, Jenkins DJ, La Vecchia C. Dietary glycemic load and colorectal cancer risk. Ann Oncol 2001; 12:173-8. [PMID: 11300319 DOI: 10.1023/a:1008304128577] [Citation(s) in RCA: 161] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Insulin and insulin-like growth factors can stimulate proliferation of colorectal cells. High intake of refined carbohydrates and markers of insulin resistance are associated with colorectal cancer. To test the insulin/colon cancer hypothesis, we determined whether the dietary glycemic index and the glycemic load are associated with colorectal cancer risk. DESIGN A case-control study on colorectal cancer conducted in Italy. Cases included 1125 men and 828 women with histologically confirmed incident cancer of the colon or rectum. Controls were 2073 men and 2081 women hospitalized for acute conditions. We calculated average daily dietary glycemic index and glycemic load, and fiber intake from a validated food frequency questionnaire. RESULTS Direct associations with colorectal cancer risk emerged for glycemic index (odds ratio (OR) in highest vs. lowest quintile = 1.7; 95% confidence interval (CI): 1.4-2.0) and glycemic load (OR = 1.8; 95% CI: 1.5-2.2), after allowance for sociodemographic factors, physical activity, number of daily meals, and intakes of fiber, alcohol and energy. ORs were more elevated for cancer of the colon than rectum. Overweight and low intake of fiber from vegetables and fruit appeared to amplify the adverse consequences of high glycemic load. CONCLUSIONS The positive associations of glycemic index and load with colorectal cancer suggest a detrimental role of refined carbohydrates in the etiology of the disease.
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Sievenpiper JL, Jenkins DJ, Josse RG, Vuksan V. Dilution of the 75-g oral glucose tolerance test improves overall tolerability but not reproducibility in subjects with different body compositions. Diabetes Res Clin Pract 2001; 51:87-95. [PMID: 11165688 DOI: 10.1016/s0168-8227(00)00209-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Poor reproducibility of the 75-g oral glucose tolerance test (75-g OGTT) is a major criticism. To test whether dilution might be a contributor, we studied the effect of administering it at 300, 600, and 900 ml on the coefficient of variation (CV) and overall tolerability. Each dilution was randomly repeated three times by 35 subjects: 11 lean (body fat [BF]: 11.5+/-1.5%, body mass index (BMI): 24.1+/-0.8 kg/m(2), age: 33+/-3 years), 12 normal (BF: 24.3+/-1.3%, BMI: 23.9+/-0.7 kg/m2, age: 33+/-3 years), and 12 obese (BF: 34.1+/-1.5%, BMI: 34.5+/-1.6 kg/m(2), age: 41+/-4 years). The protocol followed, the American Diabetes Association (ADA) guidelines with venous samples drawn at 0, 15, 30, 45, 60, 90, and 120 min. Scales assessing palatability, acceptability, satiety, nausea, and dizziness were also completed. No differences were detected in CV between the three dilutions at the 2 h-diagnostic-endpoint in any group. CV for glycemia, however, was lower for the 300-ml OGTT (10+/-2.1%) than either the 600 ml (17.9+/-2.1%) or 900-ml OGTT (19.9+/-4.4%) at 45 min in the lean group (P<0.05). CV for insulinemia was lower for the 300 ml (30.6+/-4.5%) and 600 ml (30.6+/-4.1%) OGTT than the 900-ml OGTT (53.7+/-7.9%) at 60 min in the obese group (P<0.05). When affective ratings were compared, the 600-ml OGTT scored highest on palatability and acceptability (P<0.05). We concluded that the dilution of the 75-g OGTT improves the overall tolerability but not reproducibility of results. Practitioners may choose to give it at the best-tolerated dilution.
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Marwood RD, Jenkins DJ, Correa V, Taylor CW, Potter BV. Contribution of the adenine base to the activity of adenophostin A investigated using a base replacement strategy. J Med Chem 2000; 43:4278-87. [PMID: 11063623 DOI: 10.1021/jm000265o] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Syntheses of 3'-O-alpha-D-glucopyranosyl-1-beta-D-ribofuranosidoimidazole 2',3'', 4''-trisphosphate (7) and 3'-O-alpha-D-glucopyranosyl-9-beta-D-ribofuranosidopurine 2',3'',4''- trisphosphate (8), two analogues of the superpotent 1D-myo-inositol 1,4,5-trisphosphate receptor agonist adenophostin A (2), are described. 5-O-Benzyl-1, 2-O-isopropylidene-alpha-D-ribofuranose was prepared by an improved route from 1,2-O-isopropylidene-alpha-D-xylofuranose and was coupled with 3,4-di-O-acetyl-2,6-di-O-benzyl-D-glucopyranosyl dimethyl phosphite to give 3',4'-di-O-acetyl-2',5, 6'-tri-O-benzyl-3-O-alpha-D-glucopyranosyl-1, 2-O-isopropylidene-alpha-D-ribofuranose. Removal of the isopropylidene acetal and subsequent acetylation gave the central disaccharide 1,2,3',4'-tetra-O-acetyl-2',5, 6'-tri-O-benzyl-3-O-alpha-D-glucopyranosyl-D-ribofuranose. Vorbrüggen condensation with activated imidazole or purine gave the required beta-substituted derivatives which were further elaborated to 7 and 8, respectively. Radioligand binding assays to hepatic InsP(3) receptors and functional assays of Ca(2+) release from permeabilized hepatocytes gave a rank order of potency of the ligands 2 approximately 8 > 7 approximately Ins(1,4,5)P(3) indicating that the N(6)-amino group of 2 is of little importance for activity and that a minimum of a two-fused-ring nucleobase is required for activity to exceed that of Ins(1,4,5)P(3). The role of the adenine base in the activity of the adenophostins is discussed. This general method should facilitate ready access to nucleobase-modified adenophostin analogues for SAR studies.
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Jenkins DJ, Kendall CW, Vidgen E, Vuksan V, Jackson CJ, Augustin LS, Lee B, Garsetti M, Agarwal S, Rao AV, Cagampang GB, Fulgoni V. Effect of soy-based breakfast cereal on blood lipids and oxidized low-density lipoprotein. Metabolism 2000; 49:1496-500. [PMID: 11092518 DOI: 10.1053/meta.2000.17703] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Consumption of soy protein may reduce the risk of cardiovascular disease both through reduction in serum lipids and by the antioxidant properties of protein-associated soy isoflavones. However, the effect that processing required for the manufacture of breakfast cereals may have on the lipid lowering and antioxidant activities of soy has not been studied. We have therefore assessed the health benefits of soy incorporation into breakfast cereals. Twenty-five hyperlipidemic men and women took soy (providing 36 g/d soy protein and 168 mg/d isoflavones) and control breakfast cereals, each for 3 weeks in a randomized crossover study with a 2-week washout period between treatments. Fasting blood samples were obtained pretreatment and at weeks 2 and 3 of each treatment. No significant difference was seen in serum lipids between treatments at week 3 apart from a 3.8% +/- 1.5% higher apolipoprotein A-1 level on control versus soy (P = .021). However, oxidized low-density lipoprotein (LDL) was reduced on the test compared with the control both as total dienes in LDL and as the ratio of conjugated dienes to cholesterol in the LDL fraction by 9.2% +/- 4.3% (P = .042) and 8.7% +/- 4.2% (P = .050), respectively. High isoflavone intakes in soy breakfast cereals may decrease the risk of cardiovascular disease by reducing oxidized LDL, while having no significant effect on the absolute concentration of LDL cholesterol.
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Anderson JW, Konz EC, Jenkins DJ. Health advantages and disadvantages of weight-reducing diets: a computer analysis and critical review. J Am Coll Nutr 2000; 19:578-90. [PMID: 11022871 DOI: 10.1080/07315724.2000.10718955] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND Some weight-loss diets are nutritionally sound and consistent with recommendations for healthy eating while others are "fad" diets encouraging irrational and, sometimes, unsafe practices. OBJECTIVE The purpose of the study was to compare several weight loss diets and assess their potential long-term effects. DESIGN Eight popular weight-loss diets were selected (Atkins, Protein Power, Sugar Busters, Zone, ADA Exchange, High-Fiber Fitness, Pritikin and Omish) to be non-clinically analyzed by means of a computer to predict their relative benefits/potential harm. A summary description, menu plan and recommended snacks were developed for each diet. The nutrient composition of each diet was determined using computer software, and a Food Pyramid Score was calculated to compare diets. The Mensink, Hegsted and other formulae were applied to estimate coronary heart disease risk factors. RESULTS Higher fat diets are higher in saturated fats and cholesterol than current dietary guidelines and their long-term use would increase serum cholesterol levels and risk for CHD. Diets restricted in sugar intake would lower serum cholesterol levels and long-term risk for CHD; however, higher carbohydrate, higher fiber, lower fat diets would have the greatest effect in decreasing serum cholesterol concentrations and risk of CHD. CONCLUSIONS While high fat diets may promote short-term weight loss, the potential hazards for worsening risk for progression of atherosclerosis override the short-term benefits. Individuals derive the greatest health benefits from diets low in saturated fat and high in carbohydrate and fiber: these increase sensitivity to insulin and lower risk for CHD.
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Jenkins DJ, Jenkins AL, Kendall CW, Vuksan V, Vidgen E. The Garden of Eden: Implications for cardiovascular disease prevention. Asia Pac J Clin Nutr 2000; 9 Suppl 1:S1-3. [PMID: 24398266 DOI: 10.1046/j.1440-6047.2000.00164.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Creationists and evolutionists acknowledge that the human diet has passed through at least four phases. The original plant food-based diet; a second phase of increasing meat consumption; a third phase of agricultural dependence on starchy foods; and, finally, the supermarket high-saturated fat, low-fibre phase with minimal energy expenditure. Our aim is to define the value of the original or 'Garden of Eden' diet and to speculate on which components should be retained in the modern supermarket diet. The original plant-based diet would have been high in vegetable proteins, plant sterols, dietary fibre and antioxidants, and low in saturated fats with no trans fatty acids. This diet would increase fecal cholesterol losses from the body as bile acids and neutral sterols, while providing little stimulus to cholesterol synthesis. To replace the bile acid losses we would have adapted to a relatively high capacity for cholesterol synthesis. Now, in the high-saturated fat, low-fibre supermarket age, this may be a disadvantage and predisposes consumers to high serum cholesterol and increased risk of cardiovascular disease. We believe part of the solution is a return to the plant-based 'Garden of Eden' diet combined with physical activity. A lipid-lowering portfolio containing vegetable proteins, especially soy, plant sterols and high fibre intakes combined with low saturated and trans fatty acids and cholesterol, would go a long way to reducing serum lipids and coronary heart disease risk seen in the modern Western diet.
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Jenkins DJ, Kendall CW, Vuksan V, Vidgen E, Wong E, Augustin LS, Fulgoni V. Effect of cocoa bran on low-density lipoprotein oxidation and fecal bulking. ARCHIVES OF INTERNAL MEDICINE 2000; 160:2374-9. [PMID: 10927737 DOI: 10.1001/archinte.160.15.2374] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND Legumes have reported benefits in terms of reduced risk for coronary heart disease and of colonic health. A novel legume fiber, cocoa bran, also may have favorable health effects on serum lipid levels, low-density lipoprotein (LDL) cholesterol oxidation, and fecal bulk. METHODS Twenty-five healthy normolipidemic subjects (13 men and 12 women) (mean +/- SEM age, 37 +/- 2 years; mean +/- SEM body mass index [calculated as weight in kilograms divided by the square of height in meters], 24.6 +/- 0.7) ate cocoa-bran and chocolate-flavored low-fiber breakfast cereals for 2-week periods, with 2-week washout, in a double-blind crossover study. The cocoa-bran cereal provided 25.0 g/d of total dietary fiber (TDF). The low-fiber cereal (5.6 g/d TDF) was of similar appearance and energy value. Fasting blood samples were obtained at the start and end of each period, and 4-day fecal collections were made from days 11 through 14. RESULTS High-density lipoprotein (HDL) cholesterol level was higher (7.6% +/- 2.9%; P =.02) and the LDL/HDL cholesterol ratio was lower (6.7% +/- 2.3%; P =.007) for cocoa-bran compared with low-fiber cereal at 2 weeks. No effect was seen on LDL cholesterol oxidation. Mean fecal output was significantly higher for cocoa-bran than for low-fiber cereal (56 +/- 14 g/d; P<.001) and equal to the increase seen in the same subjects with wheat fiber in a previous study. CONCLUSIONS A chocolate-flavored cocoa-bran cereal increased fecal bulk similarly to wheat bran and was associated with a reduction in the LDL/HDL cholesterol ratio. In view of the low-fat, high-fiber nature of the material, these results suggest a possible role for this novel fiber source in the diets of normal, hyperlipidemic, and constipated subjects.
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Zand RS, Jenkins DJ, Diamandis EP. Steroid hormone activity of flavonoids and related compounds. Breast Cancer Res Treat 2000; 62:35-49. [PMID: 10989984 DOI: 10.1023/a:1006422302173] [Citation(s) in RCA: 136] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Soy isoflavones have been studied extensively for estrogenic and antiestrogenic properties. Other flavonoids, found in fruits, vegetables, tea and wine, have been much less tested for steroid hormone activity. We therefore assessed the estrogenic, androgenic and progestational activities of 72 flavonoids and structurally-related compounds. These compounds were tested on BT-474 human breast cancer cells at concentrations of 10(8)-10(-5) M, with estradiol (estrogen), norgestrel (progestin) and dihydrotestosterone (androgen) used as positive controls, and ethanol (solvent) as a negative control. pS2, an estrogen-regulated protein, and prostate-specific antigen (PSA), regulated by androgens and progestins, were quantified in tissue culture supernatants using ELISA-type immunofluorometric assays developed in-house. Of the 72 compounds tested, 18 showed estrogenic activity at 10(-5) M. Of this subset, seven also showed progestational activity at this concentration. The soy isoflavones, biochanin A and genistein, showed the most potent estrogenic activity, with a dose-response effect up to 10(-7) M. Of all other flavonoids, luteolin and naringenin displayed the strongest estrogenicity, while apigenin had a relatively strong progestational activity. Based on our data, we have formulated a set of structure/function relationships between the tested compounds. Flavonoids, therefore, exhibit significant steroid hormone activity, and may have an effect in the modification of cancer risk by diet, or in cancer therapeutics and prevention.
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Jenkins DJ, Romig T. Efficacy of Droncit Spot-on (praziquantel) 4% w/v against immature and mature Echinococcus multilocularis in cats. Int J Parasitol 2000; 30:959-62. [PMID: 10927087 DOI: 10.1016/s0020-7519(00)00075-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The causative agent of alveolar hydatidosis in humans, the fox tapeworm Echinococcus multilocularis, is extending its geographical range in Europe and has been found in domestic cats in some areas. A dermally applied cestocidal treatment for domestic cats has been developed and the efficacy of this treatment is reported. Thirty purpose-bred cats were experimentally infected each with 10000 protoscoleces of Echinococcus multilocularis. Ten days later one group of ten cats was treated with Droncit(R) Spot-on (Praziquantel) 4% w/v dermally in one place on the dorsal aspect of the neck at a dose of 8 mg/kg. Eleven days later (21 days p.i.) a second group of ten cats was also treated with Droncit(R) Spot-on the same way. One group of ten cats was left untreated as controls. Twenty three days after infection the cats were examined for the presence of E. multilocularis tapeworms. No E. multilocularis were recovered from any of the cats in either of the treated groups. Echinococcus multilocularis were recovered from eight of the ten cats left untreated as controls. The worm burdens in the untreated cats were 0, 0, 5, 15, 75, 110, 220, 815, 2635, and 3045 worms per cat. The worms ranged in development from the three to four segment stage. Many of the E. multilocularis with four segments contained unshelled eggs in the terminal segment. This study indicates that Droncit(R) Spot-on (Praziquantel) 4% w/v applied dermally at 8 mg/kg is highly effective in removing E. multilocularis from the small intestine of cats infected with immature and mature (prepatent) infections of E. multilocularis. In the cats with the mature infections all tapeworms were absent from the small intestine within 2 days of treatment.
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Rosenberg Zand RS, Jenkins DJ, Diamandis EP. Genistein: a potent natural antiandrogen. Clin Chem 2000; 46:887-8. [PMID: 10839794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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Sievenpiper JL, Jenkins DJ, Josse RG, Vuksan V. Dilution of the 75-g oral glucose tolerance test increases postprandial glycemia: implications for diagnostic criteria. CMAJ 2000; 162:993-6. [PMID: 10763397 PMCID: PMC1232351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
Abstract
BACKGROUND Dilution has been noticed to increase the glycemic response to various sugars, including glucose. This effect may contribute to the poor reproducibility of the oral glucose tolerance test (OGTT). To test this hypothesis we assessed the effect of diluting a 75-g OGTT on 2-hour postprandial blood glucose based diagnostic outcomes, incremental glycemia and area under the glucose curve. METHODS On 3 different occasions, 10 subjects (mean age 40 [and standard error of the mean (SEM) 3.2] years; mean body mass index 27.2 [and SEM 1.2] kg/m2) without previously diagnosed dysglycemia were given a 300-mL, 600-mL or 900-mL 75-g OGTT in random order. The protocol followed the American Diabetes Association's guidelines. Finger-prick capillary blood samples were obtained at fasting and then 15, 30, 45, 60, 90 and 120 minutes after the start of the test. RESULTS At 30, 45 and 60 minutes, incremental glycemic concentrations were significantly higher with the 900-mL meal (means [and SEMs]: 4.9 [0.4] mmol/L, 5.1 [0.6] mmol/L and 4.6 [0.8] mmol/L, respectively) than with the 600-mL (means [and SEMs]: 4.0 [0.3] mmol/L, 4.2 [0.6] mmol/L and 3.6 [0.7] mmol/L, respectively) and the 300-mL meals (means and [SEMs]: 3.8 [0.5] mmol/L, 4.0 [0.5] mmol/L and 3.2 [0.6] mmol/L, respectively) (p < 0.05). The same was true for peak incremental blood glucose, regardless of time (p < 0.05). The area under the curve for the 900-mL meal (mean [and SEM] 404 [57] min.mmol/L) was significantly higher than for the 600-mL (mean [and SEM] 331 [51] min.mmol/L) and 300-mL meals (mean [and SEM] 280 [48] min.mmol/L) (p < 0.05). No other significant differences were observed. INTERPRETATION Dilution of the 75-g OGTT will likely not affect current screening practices that use 2-h postprandial glucose levels as the basis for diagnosis. It may, however, bias the interpretation of older criteria that rely on intermediate time points because these midpoints appear to be sensitive to alterations in the total volume of the meal ingested.
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Jenkins DJ, Kendall CW, Garsetti M, Rosenberg-Zand RS, Jackson CJ, Agarwal S, Rao AV, Diamandis EP, Parker T, Faulkner D, Vuksan V, Vidgen E. Effect of soy protein foods on low-density lipoprotein oxidation and ex vivo sex hormone receptor activity--a controlled crossover trial. Metabolism 2000; 49:537-43. [PMID: 10778882 DOI: 10.1016/s0026-0495(00)80022-0] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Plant-derived estrogen analogs (phytoestrogens) may confer significant health advantages including cholesterol reduction, antioxidant activity, and possibly a reduced cancer risk. However, the concern has also been raised that phytoestrogens may be endocrine disrupters and major health hazards. We therefore assessed the effects of soy foods as a rich source of isoflavonoid phytoestrogens on LDL oxidation and sex hormone receptor activity. Thirty-one hyperlipidemic subjects underwent two 1-month low-fat metabolic diets in a randomized crossover study. The major differences between the test and control diets were an increase in soy protein foods (33 g/d soy protein) providing 86 mg isoflavones/2,000 kcal/d and a doubling of the soluble fiber intake. Fasting blood samples were obtained at the start and at weeks 2 and 4, with 24-hour urine collections at the end of each phase. Soy foods increased urinary isoflavone excretion on the test diet versus the control (3.8+/-0.7 v 0.0+/-0.0 mg/d, P < .001). The test diet decreased both oxidized LDL measured as conjugated dienes in the LDL fraction (56+/-3 v 63+/-3 micromol/L, P < .001) and the ratio of conjugated dienes to LDL cholesterol (15.0+/-1.0 v 15.7+/-0.9, P = .032), even in subjects already using vitamin E supplements (400 to 800 mg/d). No significant difference was detected in ex vivo sex hormone activity between urine samples from the test and control periods. In conclusion, consumption of high-isoflavone foods was associated with reduced levels of circulating oxidized LDL even in subjects taking vitamin E, with no evidence of increased urinary estrogenic activity. Soy consumption may reduce cardiovascular disease risk without increasing the risk for hormone-dependent cancers.
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Abstract
Initially, it was hoped that resistant starches (ie, starches that enter the colon) would have clear advantages in the reduction of colon cancer risk and possibly the treatment of ulcerative colitis. Recent studies have confirmed the ability of resistant starch to increase fecal bulk, to increase the molar ratio of butyrate in relation to other short-chain fatty acids, and to dilute fecal bile acids. However, reduction in fecal ammonia, phenols, and N-nitroso compounds have not been achieved. At this point the picture from the standpoint of colon cancer risk reduction is not clear. Nevertheless, there is a fraction of what has been termed resistant starch (RS1), which enters the colon and acts as slowly digested, or lente, carbohydrate. Foods in this class are low glycemic index and have been shown to reduce the risk of chronic disease. They have been associated with systemic physiologic effects such as reduced postprandial insulin levels and higher high-density lipoprotein cholesterol levels. Consumption of low glycemic index foods has been shown to be related to a reduced risk of type 2 diabetes. Type 2 diabetes has in turn been related to a higher risk of colon cancer, especially colon cancer deaths. If carbohydrate has a protective role in colon cancer prevention, it may lie in the systemic effects of low glycemic index foods. The colonic advantages of different carbohydrates, therefore, remain to be documented. However, there is reason for optimism about the possible health advantages of so-called resistant starches that are slowly digested in the small intestine.
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Rosenberg Zand RS, Grass L, Magklara A, Jenkins DJ, Diamandis EP. Is ICI 182,780 an antiprogestin in addition to being an antiestrogen? Breast Cancer Res Treat 2000; 60:1-8. [PMID: 10845803 DOI: 10.1023/a:1006334132303] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The pure antiestrogen ICI 182,780 has been shown to have antiprogestin activity in reporter gene constructs. Cell lines, naturally devoid of progesterone receptors (PR) were transfected with either the A or B forms of the human PR and a luciferase construct driven by a progesterone-response element (PRE). Because this system is an artificial one, our purpose was to determine whether these observations could be made in a human breast cancer cell line, naturally containing PR. We further evaluated the dose-response of ICI 182,780 and RU-486 (mifepristone) on PR and estrogen receptors (ER) in the presence of either progesterone, norgestrel or estradiol. These effects were measured using immunoassays for prostate-specific antigen (PSA) and human glandular kallikrein (hK2) and pS2. We found that ICI 182,780 blocked progesterone-stimulated PSA and hK2 production 100% at 10(-5) M, which decreased significantly by 10-6 M. This inhibition did not occur when norgestrel was the progestin used. RU-486 showed 100% blockade for both progestins at all concentrations used. We concluded that the antiprogestin activity of ICI 182,780 exists for progesterone only. This weak antiprogestin activity may be unlikely to have significant clinical implications.
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