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Butyrylated starch intake can prevent red meat-induced O6-methyl-2-deoxyguanosine adducts in human rectal tissue: a randomised clinical trial
- Richard K. Le Leu, Jean M. Winter, Claus T. Christophersen, Graeme P. Young, Karen J. Humphreys, Ying Hu, Silvia W. Gratz, Rosalind B. Miller, David L. Topping, Anthony R. Bird, Michael A. Conlon
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- Journal:
- British Journal of Nutrition / Volume 114 / Issue 2 / 28 July 2015
- Published online by Cambridge University Press:
- 17 June 2015, pp. 220-230
- Print publication:
- 28 July 2015
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Epidemiological studies have identified increased colorectal cancer (CRC) risk with high red meat (HRM) intakes, whereas dietary fibre intake appears to be protective. In the present study, we examined whether a HRM diet increased rectal O6-methyl-2-deoxyguanosine (O6MeG) adduct levels in healthy human subjects, and whether butyrylated high-amylose maize starch (HAMSB) was protective. A group of twenty-three individuals consumed 300 g/d of cooked red meat without (HRM diet) or with 40 g/d of HAMSB (HRM+HAMSB diet) over 4-week periods separated by a 4-week washout in a randomised cross-over design. Stool and rectal biopsy samples were collected for biochemical, microbial and immunohistochemical analyses at baseline and at the end of each 4-week intervention period. The HRM diet increased rectal O6MeG adducts relative to its baseline by 21 % (P< 0·01), whereas the addition of HAMSB to the HRM diet prevented this increase. Epithelial proliferation increased with both the HRM (P< 0·001) and HRM+HAMSB (P< 0·05) diets when compared with their respective baseline levels, but was lower following the HRM+HAMSB diet compared with the HRM diet (P< 0·05). Relative to its baseline, the HRM+HAMSB diet increased the excretion of SCFA by over 20 % (P< 0·05) and increased the absolute abundances of the Clostridium coccoides group (P< 0·05), the Clostridiumleptum group (P< 0·05), Lactobacillus spp. (P< 0·01), Parabacteroides distasonis (P< 0·001) and Ruminococcus bromii (P< 0·05), but lowered Ruminococcus torques (P< 0·05) and the proportions of Ruminococcus gnavus, Ruminococcus torques and Escherichia coli (P< 0·01). HRM consumption could increase the risk of CRC through increased formation of colorectal epithelial O6MeG adducts. HAMSB consumption prevented red meat-induced adduct formation, which may be associated with increased stool SCFA levels and/or changes in the microbiota composition.
Contributors
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- By Agoston T. Agoston, Syed Z. Ali, Mahul B. Amin, Daniel A. Arber, Pedram Argani, Sylvia L. Asa, Rebecca N. Baergen, Zubair W. Baloch, Andrew M. Bellizzi, Kurt Benirschke, Allen Burke, Kenneth B. Calder, Karen L. Chang, Rebecca D. Chernock, Wang Cheung, Thomas V. Colby, Byron P. Croker, Ronald A. DeLellis, Edward F. DiCarlo, Ralph C. Eagle, Hormoz Ehya, Brett M. Elicker, Tarik M. Elsheikh, Robert E. Fechner, Linda D. Ferrell, Melina B. Flanagan, Douglas B. Flieder, Christopher S. Foster, Lillian Gaber, Karuna Garg, Kim R. Geisinger, Ryan M. Gill, Eric F. Glassy, David J. Glembocki, Zachary D. Goodman, Robert O. Greer, David J. Grignon, Gerardo E. Guiter, Kymberly A. Gyure, Ian S. Hagemann, Michael R. Henry, Jason L. Hornick, Ralph H. Hruban, Phyllis C. Huettner, Peter A. Humphrey, Olga B. Ioffe, Edward C. Klatt, Michael J. Klein, Ernest E. Lack, James N. Lampros, Lester J. Layfield, Robin D. LeGallo, Kevin O. Leslie, James S. Lewis, Virginia A. LiVolsi, Alberto M. Marchevsky, Anne Marie McNicol, Mitra Mehrad, Elizabeth Montgomery, Cesar A. Moran, Christopher A. Moskaluk, George J. Netto, G. Petur Nielsen, Robert D. Odze, Arthur S. Patchefsky, James W. Patterson, Elizabeth N. Pavlisko, John D. Pfeifer, Celeste N. Powers, Richard A. Prayson, Anja C. Roden, Victor L. Roggli, Andrew E. Rosenberg, Sherif Said, Margie A. Scott, Raja R. Seethala, Carlie S. Sigel, Jan F. Silverman, Bruce R. Smoller, Edward B. Stelow, Nora C. J. Sun, Mark W. Teague, Satish K. Tickoo, Thomas M. Ulbright, Paul E. Wakely, Jun Wang, Lawrence M. Weiss, Mark R. Wick, Howard H. Wu, Rhonda K. Yantiss, Charles Zaloudek, Yaxia Zhang, Xiaohui Sheila Zhao
- Edited by Mark R. Wick, University of Virginia, Virginia A. LiVolsi, University of Pennsylvania School of Medicine, John D. Pfeifer, Washington University School of Medicine, St Louis, Edward B. Stelow, University of Virginia, Paul E. Wakely, Jr
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- Book:
- Silverberg's Principles and Practice of Surgical Pathology and Cytopathology
- Published online:
- 13 March 2015
- Print publication:
- 26 March 2015, pp vii-x
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Enhancing the value of horizon scanning through collaborative review
- William J. Sutherland, Hilary Allison, Rosalind Aveling, Ian P. Bainbridge, Leon Bennun, David J. Bullock, Andy Clements, Humphrey Q. P. Crick, David W. Gibbons, Sarah Smith, Michael R. W. Rands, Paul Rose, Jörn P. W. Scharlemann, Martin S. Warren
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There is an increased appreciation of the need for horizon scanning: the identification and assessment of issues that could be serious in the future but have currently attracted little attention. However, a process is lacking to identify appropriate responses by policy makers and practitioners. We thus suggest a process and trial its applicability. Twelve environmental conservation organizations assessed each of 15 previously identified horizon scanning issues for their impact upon their organization and the urgency with which they should consider the issue. They also identified triggers that would result in changes in their scoring of the likely urgency and impact of the issues. This process enables organizations to identify priority issues, identify issues they can ignore until there are further developments, benchmark priorities across organizations and identify cross-organizational priorities that warrant further attention, so providing an agenda for collation of evidence, research and policy development. In this trial the review of responses by other organizations resulted in the upgrading of response by a substantial proportion of organizations for eight of the 15 issues examined. We suggest this approach, with the novel components of collaborative assessment and identification of triggers, could be adopted widely, both within conservation organizations and across a wider range of policy issues.
Intake rates and the functional response in shorebirds (Charadriiformes) eating macro-invertebrates
- John D. Goss-Custard, Andrew D. West, Michael G. Yates, Richard W. G. Caldow, Richard A. Stillman, Louise Bardsley, Juan Castilla, Macarena Castro, Volker Dierschke, Sarah. E. A. Le. V. dit Durell, Goetz Eichhorn, Bruno J. Ens, Klaus-Michael Exo, P. U. Udayangani-Fernando, Peter N. Ferns, Philip A. R. Hockey, Jennifer A. Gill, Ian Johnstone, Bozena Kalejta-Summers, Jose A. Masero, Francisco Moreira, Rajarathina Velu Nagarajan, Ian P. F. Owens, Cristian Pacheco, Alejandro Perez-Hurtado, Danny Rogers, Gregor Scheiffarth, Humphrey Sitters, William J. Sutherland, Patrick Triplet, Dave H. Worrall1, Yuri Zharikov, Leo Zwarts, Richard A. Pettifor
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- Journal:
- Biological Reviews / Volume 81 / Issue 4 / November 2006
- Published online by Cambridge University Press:
- 24 July 2006, pp. 501-529
- Print publication:
- November 2006
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As field determinations take much effort, it would be useful to be able to predict easily the coefficients describing the functional response of free-living predators, the function relating food intake rate to the abundance of food organisms in the environment. As a means easily to parameterise an individual-based model of shorebird Charadriiformes populations, we attempted this for shorebirds eating macro-invertebrates. Intake rate is measured as the ash-free dry mass (AFDM) per second of active foraging; i.e. excluding time spent on digestive pauses and other activities, such as preening. The present and previous studies show that the general shape of the functional response in shorebirds eating approximately the same size of prey across the full range of prey density is a decelerating rise to a plateau, thus approximating the Holling type II (‘disc equation’) formulation. But field studies confirmed that the asymptote was not set by handling time, as assumed by the disc equation, because only about half the foraging time was spent in successfully or unsuccessfully attacking and handling prey, the rest being devoted to searching.
A review of 30 functional responses showed that intake rate in free-living shorebirds varied independently of prey density over a wide range, with the asymptote being reached at very low prey densities (<150/m−2). Accordingly, most of the many studies of shorebird intake rate have probably been conducted at or near the asymptote of the functional response, suggesting that equations that predict intake rate should also predict the asymptote.
A multivariate analysis of 468 ‘spot’ estimates of intake rates from 26 shorebirds identified ten variables, representing prey and shorebird characteristics, that accounted for 81% of the variance in logarithm-transformed intake rate. But four-variables accounted for almost as much (77.3%), these being bird size, prey size, whether the bird was an oystercatcher Haematopus ostralegus eating mussels Mytilus edulis, or breeding. The four variable equation under-predicted, on average, the observed 30 estimates of the asymptote by 11.6%, but this discrepancy was reduced to 0.2% when two suspect estimates from one early study in the 1960s were removed. The equation therefore predicted the observed asymptote very successfully in 93% of cases.
We conclude that the asymptote can be reliably predicted from just four easily measured variables. Indeed, if the birds are not breeding and are not oystercatchers eating mussels, reliable predictions can be obtained using just two variables, bird and prey sizes. A multivariate analysis of 23 estimates of the half-asymptote constant suggested they were smaller when prey were small but greater when the birds were large, especially in oystercatchers. The resulting equation could be used to predict the half-asymptote constant, but its predictive power has yet to be tested.
As well as predicting the asymptote of the functional response, the equations will enable research workers engaged in many areas of shorebird ecology and behaviour to estimate intake rate without the need for conventional time-consuming field studies, including species for which it has not yet proved possible to measure intake rate in the field.
Introgression, tagging and expression of a leaf senescence gene in Festulolium
- HOWARD THOMAS, CLIVE EVANS, HUW MARTIN THOMAS, MICHAEL W. HUMPHREYS, GARETH MORGAN, BARBARA HAUCK, IAIN DONNISON
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- Journal:
- The New Phytologist / Volume 137 / Issue 1 / September 1997
- Published online by Cambridge University Press:
- 01 September 1997, pp. 29-34
- Print publication:
- September 1997
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A mutation of a gene (discovered in Festuca pratensis Huds. and designated sid ) confers indefinite greenness on senescing leaves. Via intergeneric hybrids with Lolium multiflorum L. and Lolium perenne L., the mutant gene (sidy) has been introgressed into a range of Lolium backgrounds. Using genomic in situ hybridization we have identified segments carrying sidy in recombinant chromosomes of Lolium–Festuca introgression lines. We also used L. perenne lines segregating 1[ratio ]1 for the staygreen character to tag the gene with molecular markers. In two mapping populations a total of 84 genotypes were screened with isoenzymes, RAPD primers, RFLP probes and AFLP primer pairs. Over 180 polymorphic loci were identified, representing 10 linkage groups spanning 600 cM. Two AFLP markers are linked to sid at 4·6 and 14·9 cM, close enough to be usable for marker-assisted selection. Introgression of sidy into Lolium temulentum L. resulted in the production of near-isogenic inbreeding lines suitable for comparative studies of gene expression. Using a variation of the method of representational difference analysis a very small number of cDNAs have been identified as promising candidates for sid, or genes directly regulated by sid.