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ABSTRACT: Intracellular folate deficiency has been implicated in colonic carcinogenesis in epidemiological studies and animal and human cancer models. Our aim was to determine the effect of folate supplementation on patients with recurrent adenomatous polyps using rectal mucosal cell proliferation as a biomarker.
Eleven patients with recurrent adenomatous polyps of the colon were randomised into a treatment group (n=6) receiving a dietary supplement of 2 mg folic acid per day for three months and a control group (n=5) receiving a placebo. Rectal biopsies where taken at 10 cm from the anal verge prior to supplementation and repeated at four, 12, and 18 weeks from the start of the supplementation. Each biopsy was immediately incubated in culture medium enriched with bromodeoxyuridine (BrdU). The S phase cells which incorporated BrdU into their DNA were identified following immunohistochemical staining. Twenty five orientated crypts were identified for each time point and the number and position of BrdU positive and BrdU negative cells were counted. BrdU labelling indices (LIs) were calculated for the entire crypt and for each of five equal compartments running consequently from the base to the luminal surface.
The LI of the treatment group (9.1 (6.7, 12.3)) and the control group (9.3 (7.8, 10.3)) were comparable at the start. Over the duration of the supplementation period, LI in the control group did not alter significantly (9.3 (7.8, 10.3) v 9.6 (8.9, 10.4)). However, LI of the folate treated group was lowered after 12 weeks of supplementation (9.1 (6.7, 12.3) v 7.4 (5.3, 9.6)). Analysis of the LI for compartments within the crypt showed that the most significant drop in number of proliferating cells was in the upper most regions of the crypt.
These data indicate that (a) folate supplementation decreases colonic mucosal cell proliferation in a high risk group for colon cancer and (b) the most significant reduction takes place at the luminal aspect of the crypt.
Gut 09/2002; 51(2):195-9. · 10.11 Impact Factor
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ABSTRACT: To examine, for the first time Bcl-2 expression in sequential (autogenous) oral mucosal biopsies taken from the same sites in a gender, risk-factor matched, Caucasoid sample, over a 21-year period.
Retrospective immunocytochemical longitudinal study of archival serial biopsies.
Computer records were used to identify biopsy specimens derived from 12 patients. These were divided into four groups: (1) Histologically innocuous lesions which remained histologically innocuous. (2) Dysplastic lesions which remained dysplastic. (3) Histologically innocuous lesions which later progressed to squamous cell carcinoma (SCC). (4) Dysplastic lesions which later progressed to SCC. This represented 65 biopsies in total. Bcl-2 expression was studied using mouse antihuman BCL-2 oncoprotein clone 124 (Dako, Denmark).
Generally, there was a lack of Bcl-2 immunoreactivity in the epithelium, with one exception in dysplastic epithelium from a group (3) patient.
These findings suggest that in our series, Bcl-2 is not expressed early in oral premalignant lesions and appears to contradict previous reports. Possible explanations for this disparity are considered.
Oral Diseases 10/2000; 6(5):318-26. · 2.49 Impact Factor
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Gastroenterology 05/1996; 110(4):1323-4. · 11.68 Impact Factor
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ABSTRACT: The thymidine analogue, bromodeoxyuridine, is substituted into DNA during DNA synthesis and can be used to identify those cells which have passed through the S-phase of the cell cycle. Incorporated bromodeoxyuridine can be detected using anti-bromodeoxyuridine monoclonal antibodies which bind to the exposed bromodeoxyuridine in single-stranded DNA after a suitable denaturation step. Hydrochloric acid is the most commonly employed denaturation agent in bromodeoxyuridine monoclonal antibody methodologies. This preliminary study was to validate the hydrochloric acid denaturation step for colorectal tumour tissue infiltrated in vivo with bromodeoxyuridine. Standard immunohistochemistry and flow cytometric techniques using Bu20a were employed across a range of hydrochloric acid concentrations. Although high labelling indices were achieved using acid concentrations of 0.10 M HCl, the optimal hydrochloric acid concentration was not the same in all tumours. Sensitivity of DNA to hydrochloric acid denaturation should be carefully considered in bromodeoxyuridine methodologies using the monoclonal antibody Bu20a.
Cytometry 03/1994; 15(2):162-8.
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ABSTRACT: DNA analysis was assessed by densitometry for 281 cases of colorectal adenocarcinoma. Detection of aneuploidy in a single case rose from 65% if one, to 92.5% when three or more sections, were analysed. Although aneuploid tumours had significantly larger nuclear areas than near diploid tumours (p = 0.009), densitometric measurements showed no association with clinicopathological variables. DNA content determined by densitometry was compared with that from flow cytometry on 465 tissue sections from 241 cases. Aneuploidy assessed by flow cytometry was significantly associated with that determined by densitometry (p < 0.01 for all comparisons), ploidy state being similar in 381 sections (82%, kappa = 0.63, p < 0.001), and 187 cases (77.6%, kappa = 0.57, p < 0.001). Univariate survival analysis showed that DNA densitometric variables had no significant association with survival in (a) all cases, (b) cases without lymph node metastases, or (c) cases without distant metastases. Multivariate regression analysis of densitometric and clinicopathological variables identified Dukes's stage, patient age, and tumour differentiation as the combination of variables most closely related to survival. Densitometric measurement of DNA content could not significantly improve on the prognostic model containing these three variables. It is concluded that, although the assessment of DNA content by densitometry is comparable with that of flow cytometry, conventional histological variables remain the best predictors of prognosis in colorectal cancer.
Gut 12/1993; 34(11):1566-71. · 10.11 Impact Factor
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ABSTRACT: Flow cytometry was performed upon 312 patients with adenocarcinoma of the colon and rectum, satisfactory results being obtained with 275 (108 diploid, 130 aneuploid and 37 tetraploid). The proportion of nondiploid instances increased from 28 percent if one, to 80 percent when six specimens were assessed per patient. Reproducibility of the technique showed substantial agreement in the assessment of deoxyribonucleic acid ploidy (Kappa value equals 0.74). Increasing values of cells in the diving (G2/M) phase of the cell cycle were associated with little lymphocytic tumor infiltration (p = 0.0002) and extensive tumor fibrosis (p = 0.003). Univariate survival analysis revealed that, although diploid tumors tended to have a better prognosis than nondiploid tumors (p = 0.06), no flow cytometric variable was significantly related to survival. Flow cytometry similarly was not of prognostic value in instances without lymph node metastases or without distant metastases. Multivariate regression analysis of flow cytometric and clinicopathologic variables identified Dukes' stage, patient age and tumor differentiation as the combination of variables most closely related to survival. No flow cytometric variable could significantly improve on the prognostic model containing these three variables. It is concluded that conventional histologic variables remain the best predictors of prognosis in carcinoma of the colon and rectum.
Surgery, gynecology & obstetrics 11/1993; 177(4):377-82.
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ABSTRACT: This study describes a novel in vitro method for the incorporation of the thymidine analogue, bromodeoxyuridine (BrdUrd), in fresh colorectal tumour tissue. Disaggregation by pronase, collagenase and DNAse resulted in high cell yields of viable single cell suspensions, representative of the original tumour, which could be infiltrated with BrdUrd. A modified ELISA identified optimal incubation times and BrdUrd concentrations. This technique has been used in preliminary studies to investigate two important areas intrinsic in the analysis of BrdUrd colorectal cell proliferation data: 1) to determine the effects of the individual constituents of the cell culture media, in particular glutamine, on BrdUrd incorporation in suspensions of colorectal cells and 2) to examine the denaturation step. This method will have wide applicability in investigations of cell proliferation status in both normal and diseased tissue.
Cell Proliferation 04/1993; 26(2):115-24. · 2.52 Impact Factor
