26 results on '"Weber TK"'
Search Results
2. The intestinal epithelial cell differentiation marker intestinal alkaline phosphatase (ALPi) is selectively induced by histone deacetylase inhibitors (HDACi) in colon cancer cells in a Kruppel-like Factor 5 (KLF5)-defendent manner
- Author
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Shin, J, Carr, A, Corner, GA, Tögel, L, Dávaos-Salas, M, Tran, H, Chueh, AC, Al-Obaidi, S, Chionh, F, Ahmed, N, Buchanan, DD, Young, JP, Malo, MS, Hodin, RA, Arango, D, Sieber, OM, Augenlicht, LH, Dhillon, Amardeep, Weber, TK, Mariadason, JM, Shin, J, Carr, A, Corner, GA, Tögel, L, Dávaos-Salas, M, Tran, H, Chueh, AC, Al-Obaidi, S, Chionh, F, Ahmed, N, Buchanan, DD, Young, JP, Malo, MS, Hodin, RA, Arango, D, Sieber, OM, Augenlicht, LH, Dhillon, Amardeep, Weber, TK, and Mariadason, JM
- Published
- 2014
3. Planning the Human Variome Project: The Spain Report
- Author
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Kaput, J, Cotton, RGH, Hardman, L, Watson, M, Al Aqeel, AI, Al-Aama, JY, Al-Mulla, F, Alonso, S, Aretz, S, Auerbach, AD, Bapat, B, Bernstein, IT, Bhak, J, Bleoo, SL, Bloecker, H, Brenner, SE, Burn, J, Bustamante, M, Calone, R, Cambon-Thomsen, A, Cargill, M, Carrera, P, Cavedon, L, Cho, YS, Chung, Y-J, Claustres, M, Cutting, G, Dalgleish, R, den Dunnen, JT, Diaz, C, Dobrowolski, S, dos Santos, MRN, Ekong, R, Flanagan, SB, Flicek, P, Furukawa, Y, Genuardi, M, Ghang, H, Golubenko, MV, Greenblatt, MS, Hamosh, A, Hancock, JM, Hardison, R, Harrison, TM, Hoffmann, R, Horaitis, R, Howard, HJ, Barash, CI, Izagirre, N, Jung, J, Kojima, T, Laradi, S, Lee, Y-S, Lee, J-Y, Gil-da-Silva-Lopes, VL, Macrae, FA, Maglott, D, Marafie, MJ, Marsh, SGE, Matsubara, Y, Messiaen, LM, Moeslein, G, Netea, MG, Norton, ML, Oefner, PJ, Oetting, WS, O'Leary, JC, Oller de Ramirez, AM, Paalman, MH, Parboosingh, J, Patrinos, GP, Perozzi, G, Phillips, IR, Povey, S, Prasad, S, Qi, M, Quin, DJ, Ramesar, RS, Richards, CS, Savige, J, Scheible, DG, Scott, RJ, Seminara, D, Shephard, EA, Sijmons, RH, Smith, TD, Sobrido, M-J, Tanaka, T, Tavtigian, SV, Taylor, GR, Teague, J, Toepel, T, Ullman-Cullere, M, Utsunomiya, J, van Kranen, HJ, Vihinen, M, Webb, E, Weber, TK, Yeager, M, Yeom, YI, Yim, S-H, Yoo, H-S, Kaput, J, Cotton, RGH, Hardman, L, Watson, M, Al Aqeel, AI, Al-Aama, JY, Al-Mulla, F, Alonso, S, Aretz, S, Auerbach, AD, Bapat, B, Bernstein, IT, Bhak, J, Bleoo, SL, Bloecker, H, Brenner, SE, Burn, J, Bustamante, M, Calone, R, Cambon-Thomsen, A, Cargill, M, Carrera, P, Cavedon, L, Cho, YS, Chung, Y-J, Claustres, M, Cutting, G, Dalgleish, R, den Dunnen, JT, Diaz, C, Dobrowolski, S, dos Santos, MRN, Ekong, R, Flanagan, SB, Flicek, P, Furukawa, Y, Genuardi, M, Ghang, H, Golubenko, MV, Greenblatt, MS, Hamosh, A, Hancock, JM, Hardison, R, Harrison, TM, Hoffmann, R, Horaitis, R, Howard, HJ, Barash, CI, Izagirre, N, Jung, J, Kojima, T, Laradi, S, Lee, Y-S, Lee, J-Y, Gil-da-Silva-Lopes, VL, Macrae, FA, Maglott, D, Marafie, MJ, Marsh, SGE, Matsubara, Y, Messiaen, LM, Moeslein, G, Netea, MG, Norton, ML, Oefner, PJ, Oetting, WS, O'Leary, JC, Oller de Ramirez, AM, Paalman, MH, Parboosingh, J, Patrinos, GP, Perozzi, G, Phillips, IR, Povey, S, Prasad, S, Qi, M, Quin, DJ, Ramesar, RS, Richards, CS, Savige, J, Scheible, DG, Scott, RJ, Seminara, D, Shephard, EA, Sijmons, RH, Smith, TD, Sobrido, M-J, Tanaka, T, Tavtigian, SV, Taylor, GR, Teague, J, Toepel, T, Ullman-Cullere, M, Utsunomiya, J, van Kranen, HJ, Vihinen, M, Webb, E, Weber, TK, Yeager, M, Yeom, YI, Yim, S-H, and Yoo, H-S
- Abstract
The remarkable progress in characterizing the human genome sequence, exemplified by the Human Genome Project and the HapMap Consortium, has led to the perception that knowledge and the tools (e.g., microarrays) are sufficient for many if not most biomedical research efforts. A large amount of data from diverse studies proves this perception inaccurate at best, and at worst, an impediment for further efforts to characterize the variation in the human genome. Because variation in genotype and environment are the fundamental basis to understand phenotypic variability and heritability at the population level, identifying the range of human genetic variation is crucial to the development of personalized nutrition and medicine. The Human Variome Project (HVP; http://www.humanvariomeproject.org/) was proposed initially to systematically collect mutations that cause human disease and create a cyber infrastructure to link locus specific databases (LSDB). We report here the discussions and recommendations from the 2008 HVP planning meeting held in San Feliu de Guixols, Spain, in May 2008.
- Published
- 2009
4. Inhibition of N-linked glycosylation of P-glycoprotein by tunicamycin results in a reduced multidrug resistance phenotype
- Author
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Kramer, R, primary, Weber, TK, additional, Arceci, R, additional, Ramchurren, N, additional, Kastrinakis, WV, additional, Steele, G, additional, and Summerhayes, IC, additional
- Published
- 1995
- Full Text
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5. Constitutive expression of multidrug resistance in human colorectal tumours and cell lines
- Author
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Kramer, R, primary, Weber, TK, additional, Morse, B, additional, Arceci, R, additional, Staniunas, R, additional, Steele, G, additional, and Summerhayes, IC, additional
- Published
- 1993
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6. Transitioning From a Traditional to a Concept-Based Curriculum: Faculty's Experience.
- Author
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Wilhelm S, Rodehorst-Weber TK, and Longoria A
- Subjects
- Faculty, Focus Groups, Humans, Leadership, Curriculum, Education, Nursing
- Abstract
Nursing education is transforming from traditional systems paradigms to concept-based curricula. We explored how this change impacts faculty using focus groups with questions adapted from Bridges' transitions model. Results revealed that many faculty did not feel there was a clear vision for the transition and felt inadequately prepared for the change. Uncertainty about their new role led some to feel displaced. To ease future transitions, we suggest that leadership clearly communicate the rationale for the change, ensure that there is a shared vision, provide an appropriate timeline for the transition, and support faculty as their roles are redefined.
- Published
- 2020
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7. Randomized, Double-Blind, Placebo-Controlled Parallel Clinical Trial Assessing the Effect of Fructooligosaccharides in Infants with Constipation.
- Author
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Souza DDS, Tahan S, Weber TK, Araujo-Filho HB, and de Morais MB
- Subjects
- Double-Blind Method, Female, Humans, Infant, Male, Treatment Outcome, Constipation prevention & control, Oligosaccharides pharmacology
- Abstract
Constipation often begins in the first year of life. The aim of this study was to assess the effect of fructooligosaccharides (FOS) in the treatment of infants with constipation. This randomized, double-blind, placebo-controlled clinical trial included infants with constipation who were randomly assigned to one of two parallel groups: FOS or placebo. Either the FOS supplement or the placebo was added to the infant formula. Thirty-six infants completed the 4-week intervention. Therapeutic success occurred in 83.3% of the FOS group infants and in 55.6% of the control group infants ( p = 0.073; one-tailed test). Compared with the control group, the FOS group exhibited a higher frequency of softer stools ( p = 0.035) and fewer episodes of straining and/or difficulty passing stools ( p = 0.041). At the end of the intervention, the mouth-to-anus transit time was shorter (22.4 and 24.5 h, p = 0.035), and the Bifidobacterium sp. count was higher ( p = 0.006) in the FOS group. In conclusion, the use of FOS in infants with constipation was associated with significant improvement in symptoms, but the results showed no statistical significance regarding the success of the therapy compared with the control group. FOS was associated with reduced bowel transit time and higher counts of the genus Bifidobacterium in the stool.
- Published
- 2018
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8. Barriers to Lynch Syndrome Testing and Preoperative Result Availability in Early-onset Colorectal Cancer: A National Physician Survey Study.
- Author
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Noll A, J Parekh P, Zhou M, Weber TK, Ahnen D, Wu XC, and Karlitz JJ
- Subjects
- Age of Onset, Colorectal Neoplasms, Hereditary Nonpolyposis genetics, Colorectal Neoplasms, Hereditary Nonpolyposis surgery, Female, Gastroenterologists, Health Care Costs, Humans, Male, Microsatellite Instability, Pathologists, Physician's Role, Rural Population, Surveys and Questionnaires, Colorectal Neoplasms, Hereditary Nonpolyposis diagnosis, Genetic Testing economics, Immunohistochemistry economics, Practice Patterns, Physicians'
- Abstract
Objective: Although widely recommended, Lynch syndrome (LS) testing with tumor microsatellite instability (MSI) and/or immunohistochemistry (IHC) is infrequently performed in early-onset colorectal cancer (CRC), and CRC generally. Reasons are poorly understood. Hence, we conducted a national survey focusing on gastroenterologists, as they are frequently first to diagnose CRC, assessing testing barriers and which specialist is felt responsible for ordering MSI/IHC. Additionally, we assessed factors influencing timing of MSI/IHC ordering; testing on colonoscopy biopsy, opposed to post-operative surgical specimens, assists decisions on preoperative germline genetic testing and extent of colonic resection (ECR)., Methods: A 21-question web-based survey was distributed through an American College of Gastroenterology email listing., Results: In total 509 completed the survey. 442 confirmed gastroenterologists were analyzed. Only 33.4% felt gastroenterologists were responsible for MSI/IHC ordering; pathologists were believed most responsible (38.6%). Cost, unfamiliarity interpreting results and unavailable genetic counseling most commonly prevented routine ordering (33.3%, 29.2%, 24.9%, respectively). In multivariable analysis, non-academic and rural settings were associated with cost and genetic counseling barriers. Only 46.1% felt MSI/IHC should always be performed on colonoscopy biopsy. Guideline familiarity predicted whether respondents felt surgical resection should be delayed until results returned given potential effect on ECR decisions., Conclusion: Inconsistencies in who is felt should order MSI/IHC may lead to diffusion of responsibility, preventing consistent testing, including preoperatively. Assuring institutional universal testing protocols are in place, with focus on timing of testing, can optimize care. Strategies addressing cost barriers and genomic service availability in rural and non-academic settings can enhance testing. Greater emphasis on guideline familiarity is required.
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- 2018
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9. Regarding "Colorectal Cancer Screening Quality Measures: Beyond Colonoscopy".
- Author
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Ahnen DJ, Schroy PC 3rd, and Weber TK
- Subjects
- Colonoscopy, Humans, Mass Screening, Occult Blood, Colorectal Neoplasms, Early Detection of Cancer
- Published
- 2016
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10. The intestinal epithelial cell differentiation marker intestinal alkaline phosphatase (ALPi) is selectively induced by histone deacetylase inhibitors (HDACi) in colon cancer cells in a Kruppel-like factor 5 (KLF5)-dependent manner.
- Author
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Shin J, Carr A, Corner GA, Tögel L, Dávalos-Salas M, Tran H, Chueh AC, Al-Obaidi S, Chionh F, Ahmed N, Buchanan DD, Young JP, Malo MS, Hodin RA, Arango D, Sieber OM, Augenlicht LH, Dhillon AS, Weber TK, and Mariadason JM
- Published
- 2015
- Full Text
- View/download PDF
11. Impact of cooked functional meat enriched with omega-3 fatty acids and rosemary extract on inflammatory and oxidative status; a randomised, double-blind, crossover study.
- Author
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Bermejo LM, López-Plaza B, Weber TK, Palma-Milla S, Iglesias C, Reglero G, and Gómez-Candela C
- Subjects
- Adult, Aged, Aged, 80 and over, Cooking, Cross-Over Studies, Diet, Double-Blind Method, Fatty Acids, Omega-6 administration & dosage, Female, Humans, Lipids blood, Male, Middle Aged, Young Adult, Fatty Acids, Omega-6 therapeutic use, Functional Food, Ledum chemistry, Meat, Oxidative Stress drug effects, Plant Extracts administration & dosage, Plant Extracts therapeutic use
- Abstract
Background & Aim: n-3 fatty acid intake has been associated with inflammatory benefits in cardiovascular disease (CVD). Functionalising meat may be of great interest. The aim of the present study was to assess the effect of functional meat containing n-3 and rosemary extract on inflammatory and oxidative status markers in subjects with risk for CVD., Methods and Results: A randomised, double-blind, cross-over study was undertaken to compare the effects on the above markers of consuming functional or control meat products. 43 volunteers with at least two lipid profile variables showing risk for CVD were randomly assigned to receive functional meat (FM) or control meat (CM) over 12-weeks with a 4-week wash-out interval before crossover. Functional effects were assessed by examining lipid profile, CRP, PAI-1, TNF-alpha, IL-6, fibrinogen (inflammatory markers), and TBARS, FRAP and 8-iso-PGF2 (oxidative status markers). 33 subjects (24 women) aged 50.7±8.8 years completed the study. In FM treatment, PAI-1, fibrinogen and 8-iso-PGF2 decreased significantly after 12 weeks, while FRAP significantly increased. In contrast, in CM treatment, a significant increase was seen in PAI-1, while FRAP significantly declined. Significant differences were also seen between the FM and CM treatments after 12 weeks in terms of the change observed in PAI-1, FRAP and 8-iso-PGF2 values. No significant differences were seen in anthropometric variables nor were adverse effects reported., Conclusion: The consumption of FM containing n-3 and rosemary extract improved oxidative and inflammatory status of people with at least two lipid profile variables showing risk for CVD. The inclusion of such functional meat in a balanced diet might be a healthy lifestyle option., (Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.)
- Published
- 2014
- Full Text
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12. The intestinal epithelial cell differentiation marker intestinal alkaline phosphatase (ALPi) is selectively induced by histone deacetylase inhibitors (HDACi) in colon cancer cells in a Kruppel-like factor 5 (KLF5)-dependent manner.
- Author
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Shin J, Carr A, Corner GA, Tögel L, Dávalos-Salas M, Tran H, Chueh AC, Al-Obaidi S, Chionh F, Ahmed N, Buchanan DD, Young JP, Malo MS, Hodin RA, Arango D, Sieber OM, Augenlicht LH, Dhillon AS, Weber TK, and Mariadason JM
- Subjects
- Alkaline Phosphatase genetics, Benzamides pharmacology, Binding Sites genetics, Blotting, Western, Butyric Acid pharmacology, Cell Differentiation genetics, Cell Line, Tumor, Colonic Neoplasms genetics, Colonic Neoplasms metabolism, Colonic Neoplasms pathology, CpG Islands genetics, DNA Methylation, Drug Resistance, Neoplasm genetics, Gene Expression Profiling, HCT116 Cells, HT29 Cells, Humans, Kruppel-Like Transcription Factors genetics, Oligonucleotide Array Sequence Analysis, Promoter Regions, Genetic genetics, Protein Binding, Pyridines pharmacology, Reverse Transcriptase Polymerase Chain Reaction, Alkaline Phosphatase metabolism, Cell Differentiation drug effects, Epithelial Cells metabolism, Histone Deacetylase Inhibitors pharmacology, Kruppel-Like Transcription Factors metabolism
- Abstract
The histone deacetylase inhibitor (HDACi) sodium butyrate promotes differentiation of colon cancer cells as evidenced by induced expression and enzyme activity of the differentiation marker intestinal alkaline phosphatase (ALPi). Screening of a panel of 33 colon cancer cell lines identified cell lines sensitive (42%) and resistant (58%) to butyrate induction of ALP activity. This differential sensitivity was similarly evident following treatment with the structurally distinct HDACi, MS-275. Resistant cell lines were significantly enriched for those harboring the CpG island methylator phenotype (p = 0.036, Chi square test), and resistant cell lines harbored methylation of the ALPi promoter, particularly of a CpG site within a critical KLF/Sp regulatory element required for butyrate induction of ALPi promoter activity. However, butyrate induction of an exogenous ALPi promoter-reporter paralleled up-regulation of endogenous ALPi expression across the cell lines, suggesting the presence or absence of a key transcriptional regulator is the major determinant of ALPi induction. Through microarray profiling of sensitive and resistant cell lines, we identified KLF5 to be both basally more highly expressed as well as preferentially induced by butyrate in sensitive cell lines. KLF5 overexpression induced ALPi promoter-reporter activity in resistant cell lines, KLF5 knockdown attenuated butyrate induction of ALPi expression in sensitive lines, and butyrate selectively enhanced KLF5 binding to the ALPi promoter in sensitive cells. These findings demonstrate that butyrate induction of the cell differentiation marker ALPi is mediated through KLF5 and identifies subsets of colon cancer cell lines responsive and refractory to this effect., (© 2014 by The American Society for Biochemistry and Molecular Biology, Inc.)
- Published
- 2014
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13. Gastrointestinal microbiota and some children diseases: a review.
- Author
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Weber TK and Polanco I
- Abstract
The bacterial colonization is defined immediately after birth, through direct contact with maternal microbiota and may be influenced during lactation. There is emerging evidence indicating that quantitative and qualitative changes on gut microbiota contribute to alterations in the mucosal activation of immune system leading to intra- or extra-intestinal diseases. A balance between pathogenic and beneficial microbiota throughout childhood and adolescence is important to gastrointestinal health, including protection against pathogens, inhibition of pathogens, nutrient processing (synthesis of vitamin K), stimulation of angiogenesis, and regulation of host fat storage. Probiotics can promote an intentional modulation of intestinal microbiota favoring the health of the host. This paper is a review about modulation of intestinal microbiota on prevention and adjuvant treatment of pediatric gastrointestinal diseases.
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- 2012
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14. Effect of dietary fibre mixture on growth and intestinal iron absorption in rats recovering from iron-deficiency anaemia.
- Author
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Weber TK, Freitas Kde C, Amancio OM, and de Morais MB
- Subjects
- Animal Feed, Animal Nutritional Physiological Phenomena, Animals, Cecum chemistry, Diet, Dietary Supplements, Feces chemistry, Hydrogen-Ion Concentration, Intestinal Absorption physiology, Iron analysis, Iron pharmacology, Liver chemistry, Male, Rats, Rats, Wistar, Anemia, Iron-Deficiency drug therapy, Dietary Fiber pharmacology, Growth drug effects, Intestinal Absorption drug effects, Iron metabolism
- Abstract
There is concern regarding the possible negative effects of ingestion of dietary fibre on growth and intestinal Fe absorption in infants. The aim of the present study was to compare the effect of a fibre mixture on the growth and the intestinal absorption of Fe in rats with Fe-deficiency anaemia with that of a diet without fibres. Faecal weight and caecal pH were also evaluated. According to the Hb depletion-repletion model, twenty-two male weaned Wistar rats were fed the AIN93-G diet without Fe until Fe-deficiency anaemia was induced with Hb < 70 g/l. The anaemic rats were divided into two groups: (1) fibre mixture group--fed 100 g of fibre mixture/kg of diet (soya polysaccharide, inulin, resistant starch, Arabic gum, fructo-oligossaccharide and cellulose) (n 11); (2) control group--fed without fibres (n 11). All diets had 157 mg of ferric citrate (30 mg of elemental Fe) added to lead to recovery from anaemia. Fe intestinal absorption was measured by Hb repletion efficiency (HRE) and apparent Fe intestinal absorption. The HRE was 44.8 (SD 9.5) % in the fibre mixture group and 43.0 (SD 9.5) % in the control group (P = 0.664). The apparent Fe absorption was 46.2 (SD 16.5) and 47.2 (SD 10.2) % (P = 0.861) in the fibre mixture and control groups, respectively. The faecal weight median was 6.17 g in the fibre mixture group and 2.11 g in the control group (P < 0.001). The caecal pH was in the same order: 6.11 (SD 0.59) and 7.07 (SD 0.34) (P < 0.001). Both the groups consumed similar quantities of diet, and growth was similar in both the groups. The fibre mixture had no influence either on growth or on Fe intestinal absorption in rats recovering from anaemia. This mixture favoured an increase in faecal weight and a decrease in caecal pH.
- Published
- 2010
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15. Developing a quality screening colonoscopy referral system in primary care practice: a report from the national colorectal cancer roundtable.
- Author
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Sifri R, Wender R, Lieberman D, Potter M, Peterson K, Weber TK, and Smith R
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- Colonoscopy methods, Follow-Up Studies, Humans, Minority Groups, Patient Education as Topic organization & administration, Program Development methods, United States, Colonoscopy standards, Colonoscopy statistics & numerical data, Colorectal Neoplasms prevention & control, Mass Screening organization & administration, Primary Health Care organization & administration, Quality Indicators, Health Care, Referral and Consultation organization & administration
- Abstract
The use of colonoscopy in colorectal cancer (CRC) screening has increased substantially in recent years. Media messages and changes in insurance reimbursement, as well as new screening guidelines from the American Cancer Society and the US Preventive Services Task Force, have contributed to this increase. Primary care providers (PCPs) are frequently responsible for making the recommendation and referral for screening. The process of successfully referring a patient for screening colonoscopy can be cumbersome and requires a coordinated effort between the PCP and the endoscopist. In recognition of the potential complexity of this process, the National Colorectal Cancer Roundtable has issued a report to describe the components of a quality screening colonoscopy referral system in primary care practice. The elements of a quality program include an optimal scheduling and referral system, the appropriate patient preparation information, consistent reporting and follow-up systems, and a detailed approach to dealing with special situations.
- Published
- 2010
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16. An A13 repeat within the 3'-untranslated region of epidermal growth factor receptor (EGFR) is frequently mutated in microsatellite instability colon cancers and is associated with increased EGFR expression.
- Author
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Yuan Z, Shin J, Wilson A, Goel S, Ling YH, Ahmed N, Dopeso H, Jhawer M, Nasser S, Montagna C, Fordyce K, Augenlicht LH, Aaltonen LA, Arango D, Weber TK, and Mariadason JM
- Subjects
- 3' Untranslated Regions, Animals, Cell Line, Tumor, Colonic Neoplasms enzymology, ErbB Receptors genetics, Gene Amplification, Humans, Mice, Mice, SCID, Microsatellite Instability, RNA, Messenger biosynthesis, RNA, Messenger genetics, Ribonuclease III antagonists & inhibitors, Ribonuclease III genetics, Sequence Deletion, Colonic Neoplasms genetics, ErbB Receptors biosynthesis, Genes, erbB-1, Mutation, Poly A genetics, Repetitive Sequences, Nucleic Acid
- Abstract
Colorectal cancers (CRC) with microsatellite instability (MSI) have clinical, pathologic, genetic, and epigenetic features distinct from microsatellite-stable CRC. Examination of epidermal growth factor receptor (EGFR) mRNA and protein expression levels in a panel of colon cancer cell lines identified strong expression of EGFR in multiple cell lines with MSI. Although no relationship between EGFR overexpression and the length of a CA dinucleotide repeat in intron 1 was observed, a variant A13/A14 repeat sequence within the 3'-untranslated region (3'-UTR) of the EGFR gene was identified, which was mutated by either mononucleotide or dinucleotide adenosine deletions in 64% of MSI cell lines and 69% of MSI colon tumors. Using a Tet-Off system, we show that this mutation increases EGFR mRNA stability in colon cancer cells, providing a mechanistic basis for EGFR overexpression in MSI colon cancer cell lines. To determine whether this mutation is a driver or a bystander event in MSI colon cancer, we examined the effect of pharmacologic and molecular inhibition of EGFR in EGFR 3'-UTR mutant MSI cell lines. Cell lines with an EGFR 3'-UTR mutation and that were wild-type (WT) for downstream signaling mediators in the Ras/BRAF and PIK3CA/PTEN pathways were sensitive to EGFR inhibition, whereas those harboring mutations in these signaling mediators were not. Furthermore, in cell lines WT for downstream signaling mediators, those with EGFR 3'-UTR mutations were more sensitive to EGFR inhibition than EGFR 3'-UTR WT cells, suggesting that this mutation provides a growth advantage to this subset of MSI colon tumors.
- Published
- 2009
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17. The performance of parents of children receiving cow's milk free diets at identification of commercial food products with and without cow's milk.
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Weber TK, Speridião Pda G, Sdepanian VL, Neto UF, and de Morais MB
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- Adult, Case-Control Studies, Female, Humans, Interviews as Topic, Male, Milk Hypersensitivity diet therapy, Socioeconomic Factors, Food Labeling, Health Knowledge, Attitudes, Practice, Milk Hypersensitivity prevention & control, Parents
- Abstract
Objective: To investigate how well the parents of children on cow's milk free diets perform at recognizing whether or not expressions describe and foods contain cow's milk proteins., Methods: Interviews were conducted with 24 parents of children on cow's milk and by-products exclusion diets and 23 parents of children with no need for any type of exclusion diet. They were asked if they recognized 12 expressions relating to cow's milk. They were then asked to classify 10 commercial food products in terms of whether or not they contained cow's milk proteins., Results: Terms that included the word milk were more often recognized by both groups of parents. The parents of children on exclusion diets recognized the terms cow's milk protein, traces of milk and milk formulation or preparation most frequently (p < 0.05). Less than 25.0% of those interviewed recognized casein, caseinate, lactalbumin and lactoglobulin. Both groups correctly identified more of the commercial products containing cow's milk than those free from milk. The median number of products containing cow's milk (total = 5) correctly identified by the parents of children on exclusion diets (4.0) was greater than for the control group (3.0; p = 0.005). Reading at least one label was associated with a greater chance of correctly identifying more than five of the 10 products (odds ratio = 8.0)., Conclusions: Despite having received guidance, the parents of children on exclusion diets were not fully prepared to manage these diets, indicating a need for improvements to the instruction provided when indicating exclusion diets.
- Published
- 2007
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18. Modulation of CDK2-AP1 (p12(DOC-1)) expression in human colorectal cancer.
- Author
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Yuan Z, Gaba AG, Kent TS, Bennett A, Miller A, and Weber TK
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- Apoptosis physiology, Base Pair Mismatch, Base Sequence, Blotting, Western, Cell Line, Tumor, Cell Proliferation, Humans, Microsatellite Repeats genetics, Molecular Sequence Data, Mutation, RNA Interference, RNA, Messenger analysis, Reverse Transcriptase Polymerase Chain Reaction, Colorectal Neoplasms genetics, Gene Expression Regulation, Neoplastic, Tumor Suppressor Proteins biosynthesis, Tumor Suppressor Proteins genetics
- Abstract
We have previously demonstrated an association between microsatellite instability and decreased CDK2-AP1 (p12(DOC-1)) expression in human colorectal cancer (CRC) cell lines. In those same studies, induction of CDK2-AP1 expression promoted both cell cycle arrest and apoptosis. The goals of our present study were to better understand the mechanisms leading to reduced CDK2-AP1 expression in microsatellite unstable (MSI) CRC and to study further the effect of CDK2-AP1 modulation on cell proliferation and apoptosis utilizing RNA interference (RNAi) techniques. We used direct sequencing to screen for mutations of the poly (T)8 microsatellite-like region in the 3' end of the CDK2-AP1 gene in 24 CRC cell lines. We then utilized an in vitro human mismatch repair (MMR) recombinant system to assess for correction of the mutation and changes in CDK2-AP1 expression secondary to hMLH1 transfection. We also investigated the effect of CDK2-AP1 modulation in four settings: (1) native CDK2-AP1 absence, (2) endogenous CDK2-AP1 expression, (3) RNAi-induced CDK2-AP1 inhibition and (4) induced CDK2-AP1 over expression. The mutation - del T poly (T)8 - at the 3' end of the CDK2-AP1 gene was found in 3/12 (25%) of MSI CRC cell lines, but in none of the microsatellite stable samples (0/12). Interestingly, when wild-type MMR protein - MLH1 - was induced in an in vitro human recombinant system, the del T poly (T)8 mutation was reversed and CDK2-AP1 expression increased. RNAi-mediated CDK2-AP1 inhibition was associated with decreased apoptosis and increased cell proliferation in CDK2-AP1-non deficient CRC cell lines. We conclude that mutations in the microsatellite-like sequence of the CDK2-AP1 gene in MSI CRC are associated with decreased CDK2-AP1 expression. In addition, modulation of CDK2-AP1 expression in human CRC alters cell proliferation and apoptosis.
- Published
- 2005
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19. Differential expression of DOC-1 in microsatellite-unstable human colorectal cancer.
- Author
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Yuan Z, Sotsky Kent T, and Weber TK
- Subjects
- Apoptosis, Base Pair Mismatch, Caco-2 Cells, Cell Line, Colorectal Neoplasms metabolism, Expressed Sequence Tags, Frameshift Mutation, Gene Expression Regulation, Neoplastic, Genes, Tumor Suppressor, Humans, Neoplasm Proteins deficiency, Neoplasm Proteins genetics, RNA, Messenger metabolism, S Phase, Transfection, Colorectal Neoplasms genetics, Microsatellite Repeats genetics, Tumor Suppressor Proteins metabolism
- Abstract
The precise genetic mechanism of malignant transformation in DNA mismatch repair deficient, microsatellite-unstable colorectal cancer (CRC) has yet to be elucidated. We employed cDNA microarray to identify patterns of gene expression among CRC cell lines and to compare directly lines with and without microsatellite instability. This study was undertaken to test the hypothesis that microsatellite-unstable CRC cell lines demonstrate specific patterns of gene expression that differ significantly from those observed among microsatellite-stable CRC. Multiple differential expression patterns were identified. Genes demonstrating differential expression included deleted-in-oral-cancer-1 (DOC-1), a highly conserved growth suppressor. DOC-1 expression correlated with microsatellite status, with significantly decreased expression in microsatellite-unstable cell lines and constitutive expression in microsatellite-stable cell lines. We also observed alterations in the biologic behavior of p12(DOC-1)-deficient cell lines, with increased S phase and decreased apoptosis compared to microsatellite-stable (DOC-1+) cell lines. Transfection of p12(DOC-1) into SW48, which lacks p12(DOC-1) expression, resulted in cell cycle and apoptosis profiles similar to other p12(DOC-1)+ cell lines. These results support the hypothesis that microsatellite-unstable CRC is characterized by novel patterns of gene expression different from those associated with microsatellite-stable CRC, and demonstrate that p12(DOC-1) has tumor suppressor potential in colon epithelial cells.
- Published
- 2003
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20. Somatic frameshift mutations in DNA mismatch repair and proapoptosis genes in hereditary nonpolyposis colorectal cancer.
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Yamamoto H, Sawai H, Weber TK, Rodriguez-Bigas MA, and Perucho M
- Subjects
- Adult, Aged, Colorectal Neoplasms, Hereditary Nonpolyposis pathology, Female, Humans, Male, Middle Aged, Pedigree, Proto-Oncogene Mas, Apoptosis genetics, Colorectal Neoplasms, Hereditary Nonpolyposis genetics, DNA Repair genetics, DNA, Neoplasm genetics, Frameshift Mutation
- Abstract
An exacerbated genomic instability at simple repeated sequences characterizes cancer of the microsatellite mutator phenotype (MMP). The majority of hereditary nonpolyposis colon cancers (HNPCCs) and about 15% of nonselected ("sporadic") gastrointestinal tumors belong to the MMP pathway of tumorigenesis. Colorectal MMP+ and MMP- tumors exhibit fundamental differences in genotype and phenotype. We have shown previously that "sporadic" MMP+ colon cancers exhibit a paradoxical low incidence of somatic mutations in the p53 tumor suppressor gene and the c-K-ras proto-oncogene. On the other hand, gastrointestinal MMP+ cancers frequently harbor frameshift mutations in genes containing mononucleotide repeats. These include the cell growth regulator gene TGFbetaRII and the proapoptotic gene BAX. We have also recently shown the frequent presence of frameshift mutations in (A)8 and (C)8 tracts within the hMSH3 and hMSH6 DNA mismatch repair genes in sporadic colon cancer of the MMP. Here, we describe the nearly identical incidence of somatic frameshift mutations in these genes in a panel of 27 HNPCC MMP+ cancers: 52% in hMSH3 and BAX and 33% in hMSH6. In contrast, no mutations in any of these genes were found in 10 MMP- cancers of HNPCC patients. These results show that the multistep model for the unfolding of the MMP also applies to HNPCC and further illustrate the importance of the escape from apoptosis in the MMP pathway for gastrointestinal cancer. They also underscore the differences in genotype between tumors with and without enhanced microsatellite instability and the similarities in genotype between tumors of the MMP regardless of their hereditary or sporadic nature.
- Published
- 1998
21. Health, life, and disability insurance and hereditary nonpolyposis colorectal cancer.
- Author
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Rodriguez-Bigas MA, Vasen HF, O'Malley L, Rosenblatt MJ, Farrell C, Weber TK, and Petrelli NJ
- Subjects
- Colonoscopy economics, Colonoscopy statistics & numerical data, Genetic Testing, Germ-Line Mutation, Heterozygote, Humans, Insurance Coverage, Surveys and Questionnaires, Colorectal Neoplasms, Hereditary Nonpolyposis genetics, Colorectal Neoplasms, Hereditary Nonpolyposis physiopathology, Insurance, Disability, Insurance, Health, Insurance, Life
- Published
- 1998
- Full Text
- View/download PDF
22. Genomic DNA-based hMSH2 and hMLH1 mutation screening in 32 Eastern United States hereditary nonpolyposis colorectal cancer pedigrees.
- Author
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Weber TK, Conlon W, Petrelli NJ, Rodriguez-Bigas M, Keitz B, Pazik J, Farrell C, O'Malley L, Oshalim M, Abdo M, Anderson G, Stoler D, and Yandell D
- Subjects
- Adult, Base Sequence, Family, Female, Genetic Testing, Genotype, Humans, Middle Aged, Molecular Sequence Data, MutS Homolog 2 Protein, Phenotype, Polymerase Chain Reaction, United States, Colorectal Neoplasms, Hereditary Nonpolyposis genetics, DNA-Binding Proteins, Germ-Line Mutation genetics, Proteins genetics, Proto-Oncogene Proteins genetics
- Abstract
Hereditary nonpolyposis colorectal cancer (HNPCC) is an autosomal dominant cancer syndrome characterized by early age of onset colorectal cancer (mean 45 years) as well as endometrial, urinary tract, and upper gastrointestinal adenocarcinomas. The HNPCC phenotype has been shown to segregate with germline mutations in the human homologues of the DNA mismatch repair genes MSH2, MLH1, PMS1, and PMS2. However, the majority of published DNA mismatch repair gene mutation surveys associated with HNPCC kindreds report multiple levels of preselection, including 2p and 3p chromosomal linkage analysis and the evaluation of microsatellite instability of proband colorectal cancers prior to mutation analysis. For this reason, the concise contribution of each of the known DNA mismatch repair genes to the HNPCC phenotype remains unknown. We report the results of a genomic DNA-based analysis of hMSH2 and hMLH1 germline mutations in 32 unrelated Eastern United States HNPCC kindreds. These families were selected for study on the basis of phenotype only. We identified three hMSH2 and six hMLH1 mutations in eight families, for a positive mutation rate of 25%. Two mutations were identified in one of the families. Four of the mutations detected have not been reported in the literature previously. One of the mutation-positive families is African American; the others were of European-American ancestry. These results provide a clarification of the contribution of hMSH2 and hMLH1 to the HNPCC phenotype and suggest that in the majority of Eastern United States HNPCC kindreds selected by phenotype alone, the molecular genetic basis for the disease remains unknown.
- Published
- 1997
23. Postoperative complications after splenectomy for hematologic malignancies.
- Author
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Horowitz J, Smith JL, Weber TK, Rodriguez-Bigas MA, and Petrelli NJ
- Subjects
- Adolescent, Adult, Aged, Child, Female, Humans, Incidence, Male, Middle Aged, Retrospective Studies, Risk Factors, Splenectomy mortality, Survival Analysis, Treatment Outcome, Leukemia surgery, Lymphoma surgery, Splenectomy adverse effects
- Abstract
Objective: The authors analyzed the frequency and character of postoperative complications after splenectomy in patients with hematologic malignancies, and correlated these findings with preoperative conditions that could have predicted their outcome., Summary Background Data: Splenectomy is performed for hematologic malignancies for diagnostic and therapeutic indications. The role of splenectomy for lymphoproliferative and myeloproliferative malignancies is complex and sometimes controversial., Methods: The medical records of 135 patients undergoing splenectomies for hematologic malignancies at Roswell Park Cancer Institute from January 1, 1984 to December 31, 1993 were reviewed retrospectively. These included Hodgkin's disease (HD), hairy cell leukemia (HCL), non-Hodgkin's lymphoma (NHL), chronic lymphocytic leukemia (CLL), chronic myelogenous leukemia (CML), and a miscellaneous group., Results: The overall postoperative complication and mortality rates for all patients were 52% and 9%, respectively. The complication rate was 63% for patients whose spleens weighed greater than 2000 g, and 29% for patients whose spleens weighed less than 2000 g (p = 0.001). Seventy-three percent of the postoperative deaths were due to septic complications, only one of which was caused by an encapsulated organism. Complications occurred in less than 20% of patients with the diagnosis of HD and HCL; more than 50% of patients with NHL, CLL, and CML suffered postoperative complications., Conclusions: Splenectomy performed in patients with hematologic malignancies is a potentially morbid procedure. Splenic size was the only preoperative factor found to be predictive of postoperative complications. The complication rate differed significantly between the different diagnostic subgroups.
- Published
- 1996
- Full Text
- View/download PDF
24. An anoxia inducible endonuclease and enhanced DNA breakage as contributors to genomic instability in cancer.
- Author
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Russo CA, Weber TK, Volpe CM, Stoler DL, Petrelli NJ, Rodriguez-Bigas M, Burhans WC, and Anderson GR
- Subjects
- Animals, Cell Hypoxia physiology, Colorectal Neoplasms enzymology, Colorectal Neoplasms genetics, DNA, Neoplasm genetics, DNA, Neoplasm metabolism, Endonucleases metabolism, Enzyme Induction, Female, Fibroblasts metabolism, Gene Amplification, Genome, Humans, Mammary Neoplasms, Experimental enzymology, Mammary Neoplasms, Experimental genetics, Molecular Weight, Neoplasms enzymology, Rats, Rats, Inbred F344, DNA Damage, Endonucleases biosynthesis, Fibroblasts physiology, Neoplasms genetics
- Abstract
Fischer rat embryo fibroblasts subjected to temporary anoxia followed by an aerobic recovery period show genomic instability in the form of highly elevated CAD gene amplification rates. As revealed by flow cytometric analysis this is associated with DNA breakage in vivo, followed by repair during the recovery period. Such genomic instability parallels expression of a M(r) 29,000/31,000 endonuclease; this enzyme requires no added divalent metal ion and has a pH optimum of about 6.5. The same endonuclease was found to be expressed within healing wounds and in four of ten human colorectal cancers but was not seen in eight normal colorectal tissue samples. Our results indicate that DNA breakage resulting from endogenous endonuclease activity can have a substantial effect in modulating genomic instability.
- Published
- 1995
25. Immortalization and neoplastic transformation of normal rat colon epithelium: an in vitro model of colonic neoplastic progression.
- Author
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Pories SE, Weber TK, Simpson H, Greathead P, Steele G Jr, and Summerhayes IC
- Subjects
- Animals, Cell Division, Cell Line, Transformed, Colon metabolism, Colonic Neoplasms metabolism, Gene Expression, Intestinal Mucosa metabolism, Phosphotyrosine, Rats, Reference Values, Simian virus 40 genetics, Tyrosine analogs & derivatives, Tyrosine metabolism, Cell Transformation, Neoplastic, Colon cytology, Colonic Neoplasms etiology, Cytological Techniques, Intestinal Mucosa cytology
- Abstract
Background: Because of the refractory nature of colon epithelium to growth and maintenance in vitro, the cell lines currently available for study are derived from tumors. Unlike most epithelial model systems, there exist no preneoplastic, nontumorigenic colon cell lines for manipulation and study., Methods: Intact fetal rat colon was cultured in the presence of a feeder layer of cells producing a retrovirus that harbors the SV40 LT gene resulting in the establishment of immortalized colon cell lines., Results: The epithelial and intestinal origin of cell lines was established from the constitutive expression of keratin and villin, respectively. All cell lines displayed an absence of anchorage independent growth and failed to produce tumors in vivo. Neoplastic transformation of immortalized rat colon epithelial cell lines was achieved following introduction of individual oncogenic ras gene members or the v-src oncogene. Probing of cell lysates with phosphotyrosine antibodies revealed altered phosphotyrosyl protein profiles associated with different stages of colonic neoplastic progression., Conclusions: The establishment of immortalized nontumorigenic colon epithelial cell lines facilitates the biochemical analysis of events associated with different stages of colonic neoplastic progression. In addition, this simple culture technique lends itself to studies involving alternative genetic elements implicated in the genesis of colon tumors.
- Published
- 1993
- Full Text
- View/download PDF
26. Differential pp60c-src activity in well and poorly differentiated human colon carcinomas and cell lines.
- Author
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Weber TK, Steele G, and Summerhayes IC
- Subjects
- Cell Differentiation, Colonic Neoplasms pathology, Humans, Phosphoproteins analysis, Proto-Oncogene Proteins pp60(c-src) physiology, Tumor Cells, Cultured, Colonic Neoplasms enzymology, Proto-Oncogene Proteins pp60(c-src) analysis
- Abstract
The results presented in this report demonstrate increased pp60c-src kinase activity associated with moderate to well differentiated colon tumors, corroborating previous observations by other groups. Extension of this analysis to include a small number of poorly differentiated colon carcinomas revealed src kinase activity comparable to that observed in normal colonic mucosa, considerably less than that observed in moderate/well differentiated lesions. Correlations of src kinase activity with differentiation was confirmed within a panel of colon cell lines where increased activity, associated with moderate/well differentiated lines, was accompanied by increased expression of pp60c-src protein. Use of an antiphosphotyrosine antibody in immunoprecipitation revealed the presence of novel phosphotyrosyl cellular substrates in human colon cell lines displaying elevated pp60c-src kinase activity. These observations suggest a role for the src protooncogene in colonic differentiation pathways.
- Published
- 1992
- Full Text
- View/download PDF
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