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A M Abbasi

Publications and source records attributed to A M Abbasi.

7 recordsLinked to original sources
PubMed1998

Loss of Bcl-2 expression correlates with tumour recurrence in colorectal cancer.

AIMS: To investigate the association between immunohistochemical expression of Bcl-2 and p53 in colorectal cancer and tumour recurrence following surgery. METHODS: Sixty six cases of Dukes' B colorectal carcinoma were studied. All tumours were moderately differentiated and were shown to be histologically clear of the resection margins. Immunohistochemistry was performed on formalin fixed paraffin wax embedded tissue using monoclonal antibodies for p53 and Bcl-2. The Bcl-2 staining was assessed separately for relative intensity of staining and percentage of positive tumour cells and given a final score which combined the two factors. The p53 staining was assessed on number of positive tumour cells only. The patterns of immunostaining of those cases in which there had been tumour recurrence were compared with those cases in which there was no tumour recurrence (controls). RESULTS: A statistically significant inverse association was found between Bcl-2 score and tumour recurrence (median Bcl-2 score of 6 (interquartile range (IQR) 2-9) in patients with recurrent disease; median Bcl-2 score of 8 (IQR 6-10) in those without recurrence; p = 0.03). When examined separately, both the intensity of expression and percentage of positive tumour cells were significantly associated with tumour recurrence (p = 0.04 in each case). There was no association between p53 staining and tumour recurrence. CONCLUSION: Results suggest that, when controlled for differentiation, Bcl-2 expression is a prognostic marker and may be useful as an adjunctive test in clinical decision making.

Biomarkers, Tumor↗
PubMed1997

Tumour recurrence is associated with Jass grouping but not with differences in E-cadherin expression in moderately differentiated Dukes' B colorectal cancers.

AIMS: To assess whether immunohistochemical expression of the putative invasion suppressor, E-cadherin, is associated with tumour recurrence in colorectal cancer, independent of Dukes' stage and degree of differentiation, and thus to determine whether measurement of E-cadherin is clinically useful. METHODS: 90 moderately differentiated Dukes' B colorectal carcinomas from patients who had been followed up for at least six years were examined. All were from curative resections performed at St Mark's Hospital and the tumours were shown, on histology, to be clear of all resection margins. Tumours were reviewed and additionally classified in accordance with the Jass grouping system. Immunohistochemical analysis of E-cadherin expression was performed for each tumour using the monoclonal antibody HECD 1. RESULTS: The Jass group ranged between I and III and there was a significant association between Jass group and tumour recurrence (p < 0.05). Positive E-cadherin expression was seen in 40/69 (58%) of non-recurrent and 13/21 (62%) recurrent cases respectively. There was no significant difference in E-cadherin expression between the two groups of tumours. CONCLUSIONS: Even when controlled for Dukes' stage and differentiation, the Jass grouping system yields useful prognostic information; E-cadherin, however, does not predict outcome in the important group of moderately differentiated Dukes' B colon cancers, and may be of little independent prognostic value in other colon cancers.

Cadherins↗
PubMed1995

Immunohistochemical study of the colonic muscle and innervation in idiopathic chronic constipation.

PURPOSE: This study was designed to investigate neural and muscular features of the colonic wall in patients with severe idiopathic constipation. METHODS: By using quantitative immunohistochemistry, resected specimens from 14 patients with idiopathic chronic constipation and 17 nonobstructed cancer controls were studied. RESULTS: Routine histology revealed no significant histologic abnormality throughout the colon apart from four cases of melanosis coli. Ratio of the thickness of circular to longitudinal muscle was significantly lower in the left colon in constipated subjects. The myenteric plexus appeared morphologically normal in all subjects. S-100 protein, which stains neuronal supporting tissues, demonstrated an increase in the proportion of neural tissue in the myenteric plexus. There was an increased number of PGP-9.5 immunoreactive nerve fibers in the muscularis propria in constipated patients, and this was significantly higher in the ascending and descending colon. CONCLUSION: Intractably constipated patients have alterations in the neural composition of the colonic myenteric plexus and innervation of the circular muscle.

Adolescent↗
PubMed1993

CD44 is associated with proliferation in normal and neoplastic human colorectal epithelial cells.

Flash-frozen biopsies obtained from surgical specimens of three adenomatous polyps and 22 colorectal adenocarcinomas (19 primary and three metastatic) were tested by immunohistochemistry for CD44 expression using F10-44-2 monoclonal antibody. CD44 positivity was correlated with proliferative status defined by Ki-67 monoclonal antibody reactivity. In normal colonic mucosa, CD44 was expressed in the proliferative zone of crypts. In tumours, CD44 expression was associated with proliferative areas irrespective of tumour stage or differentiation. Non-proliferating areas of the carcinomatous epithelium did not express CD44 although non-proliferating stromal lymphoid tissue did. There was no apparent association with tumour progression. F10-44-2-defined CD44 is consistently expressed during proliferation by normal colorectal epithelial cells and by both benign and malignant colorectal tumour cells.

Adenocarcinoma↗
PubMed1992

Localization of CEA messenger RNA by in situ hybridization in normal colonic mucosa and colorectal adenocarcinomas.

Carcinoembryonic antigen (CEA) mRNA expression was studied in 14 cases of normal colorectal mucosa and colonic adenocarcinomas using in situ hybridization with a 32P-labelled cDNA probe to the unique 3'-untranslated region of CEA. This approach has the advantage that the target mRNA remains in the cell of origin, whereas there is considerable ambiguity in immunocytochemistry data for CEA because the protein is secreted. Furthermore, the specific cDNA probe overcomes potential problems of immunological cross-reactivity with other members of the CEA family. The results demonstrated that abundant, heterogeneously distributed CEA mRNA was present in colorectal adenocarcinomas, with the highest levels in cells lining glandular structures. Parallel immunohistochemistry with anti-CEA monoclonal antibody A5B7 showed that the regions of tumours with the highest levels of CEA mRNA also had the highest CEA protein levels, suggesting that the heterogeneous distribution reflects CEA expression rather than differential secretion of the protein. In the normal colonic mucosa, CEA mRNA expression was observed in surface epithelial cells and goblet cells of the upper crypts, with very low hybridization in the mid crypt and at the base. This crypt-surface distribution was identical to that observed for CEA protein. In situ hybridization therefore confirms that high levels of CEA mRNA are expressed in differentiated surface epithelial cells of the normal colon.

Adenocarcinoma↗