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Biomedical subjects

K Sheahan

Publications and source records attributed to K Sheahan.

At least 19 recordsLinked to original sources
PubMed2005

Association between cyclooxygenase-2-expressing macrophages, ulceration and microvessel density in colorectal cancer.

AIM: In colorectal carcinomas, cyclooxygenase-2 (COX-2) is expressed predominantly by epithelial cells and is implicated in tumour progression. Tumour-associated macrophages may influence tumour growth, proliferative rate and angiogenesis and also express COX-2 when activated. Thus they may play an important stromal-epithelial role in carcinogenesis. Tauhe aim of this study was to define the relationship between microvessel density (MVD), tumour COX-2 and macrophage COX-2 expression. METHODS AND RESULTS: Sixty-five cases of formalin-fixed paraffin-embedded colorectal cancer were included in the study. Tissues were immunostained for COX-2, CD68 (macrophage marker) and CD34 (endothelial marker to assess MVD). Thirty-six cases were grossly ulcerated cancers and 29 cases showed focal/microscopic ulceration. Macrophages were in high concentration at the base of ulcerated areas, and were also diffusely dispersed within tumoral stroma. However, the pattern of macrophage COX-2 expression revealed two populations of macrophages--those deep within the tumour (negative for COX-2) and those at the base of ulcers (positive for COX-2). In all cases, the tumour epithelial cells expressed COX-2. MVD was higher at the base of ulcers, adjacent to COX-2+ macrophages, and was lower deep within the tumour. CONCLUSIONS: In colorectal cancers, macrophages may have a dual role. Those concentrated at the base of the ulcers, where there is an associated high MVD, may induce angiogenesis, but their function may be in a healing/repair process. The lack of COX-2+ macrophages and lower MVD deep within the tumour suggests that it may be the epithelial COX-2 component that is important in tumour progression.

Antigens, CD↗
PubMed2005

Pathological response following long-course neoadjuvant chemoradiotherapy for locally advanced rectal cancer.

AIMS: To standardize the pathological analysis of total mesorectal excision specimens of rectal cancer following neoadjuvant chemoradiotherapy for locally advanced disease (T3/T4), including tumour regression. METHODS AND RESULTS: Standardized dissection and reporting was used for 60 patients who underwent total mesorectal excision following long-course chemoradiotherapy. Tumour regression was scored by two pathologists (K.S., D.G.) using both an established 5-point tumour regression grade (TRG), and a novel 3-point grade. Both scores were evaluated for interobserver variability. A complete or near-complete pathological response (3-point TRG 1) was found in 10 patients (17%). Using the 5-point TRG, there was good agreement between both pathologists (kappa = 0.64). Using the 3-point grade, agreement was excellent (kappa = 0.84). No disease recurrence has been reported in patients with a complete, or near complete pathological response (3-point TRG 1), after a mean follow-up of 22 months. CONCLUSION: Tumour regression grade is a useful method of scoring tumour response to chemoradiotherapy in rectal cancer. TRG 1 and 2 can be regarded as a complete pathological response (ypT0). A modified 3-point grade has the advantage of better reproducibility, with similar prognostic significance.

Adult↗
PubMed2004

Expression of Cathepsin B and L antigen and activity is associated with early colorectal cancer progression.

Cathepsin B and Cathepsin L are cysteine proteases important in the process of invasion and metastasis. The aim of our study was to assay antigen and activity levels of these enzymes and to correlate these with established clinical and pathological prognostic parameters including patient survival. 99 patients undergoing operations for colorectal cancer were included in this study. We quantitated cathepsin B and L levels in matched normal mucosa and cancer samples using an enzyme-linked immunosorbent assay (ELISA) and specific activity assays and expressed the results as tumour/normal ratios. Significant correlations were found between tumour/normal cathepsin B and L antigen and activity ratios. Cathepsin B and L tumour/normal activity ratios were greater than 1 in early stage disease and there were gradual reductions in cathepsin B (P = 0.02) and L (P = 0.03) activity ratios with advancing tumour stage. Survival of patients with potentially curative disease was inversely related to both cathepsin B (P = 0.007) and L (P = 0.001) activity ratio, in addition to cathepsin L antigen ratio (P = 0.008). Our findings suggest that cysteine proteases play an important role in colorectal cancer progression.

Adult↗
PubMed2004

An evaluation of left sided colonic polyps as a marker for right sided cancers.

The detection of a left-sided polyp on flexible sigmoidoscopy has been suggested as providing a heralding sign for right-sided tumours. We assessed our own experience with right-sided colonic cancers with reference to detection modality, surgical intervention and their association with left-sided polyps. We performed a retrospective review of a prospectively collected colorectal cancer database, with endoscopic and radiological records. Patients were subcategorised on the basis of the presence or absence of left-side polyps. Ninety-one consecutive patients who underwent curative surgery for right-sided colonic cancers were studied. Endoscopy was used to detect right-sided carcinomas in 10 (83%) of the 12 cases with synchronous left-sided polyps and radiological imaging utilised in 2 cases. In patients without evidence of left sided disease endoscopy was used in 40 (51%) of the 79 patients. In our experience most right sided cancers do not have a synchronous polyp evident on the left side 79 (87%).

Adult↗
PubMed2003

Peritoneal involvement in stage II colon cancer.

A pathologist (K.S.) reviewed histologic slides for peritoneal involvement by tumor cells for 118 patients with stage II colon cancer. Patients were followed up for a median of 6 years. Tumor cells were found free in the peritoneal space in 16 cases (13.6%). The presence of cancer cells free in the peritoneal space was associated with lymphovascular invasion (P = .001) and neural invasion (P < .001). The overall 5-year survival was 80% in the patient population, but was 39% and 86% for those with and without tumor cells free in the peritoneal space, respectively (P < .0001). Multivariate analysis confirmed that free tumor cells within the peritoneal space (P < .0001) and lymphovascular invasion (P = .007) were related independently to outcome. Peritoneal involvement with tumor cells free in the peritoneal space in stage II colon cancer is a powerful indicator of outcome; patients have a survival similar to that for patients with stage III disease.

Adult↗
PubMed2001

Hemichorea, moya-moya, and ulcerative colitis.

This is a case report linking chorea, colitis, and moya-moya. The clear involvement in the vasculopathy of the basal ganglia offers an obvious substrate for the movement disorder.

Adolescent↗
PubMed2001

Tissue cytokine and chemokine expression in inflammatory bowel disease.

OBJECTIVE AND DESIGN: This study aimed to determine if mucosal expression of the chemokines IL-8, RANTES and MCP-1 and the pro-inflammatory cytokines TNFalpha and IL-6 are elevated in patients with inflammatory bowel disease. MATERIALS AND SUBJECTS: Intestinal mucosa samples were obtained at the time of surgical resection, n = 16 from each of the following groups: normal/control, CD and UC. METHODS: An homogenate was prepared of each tissue sample and cytokines measured by ELISA. RESULTS: IL-8 was significantly increased in both disease groups compared to controls Similarly, RANTES levels were also significantly increased. MCP-1 levels were increased in both disease groups, this increase was statistically significant in the UC group only. TNFalpha and IL-6 were significantly increased in the CD group only. CONCLUSIONS: Chemokines, together with key cytokines that promote their release are elevated in mucosal tissues from patients with IBD. It is likely that these chemokines play an important role in the perpetuation of tissue destructive inflammatory processes.

Chemokine CCL2↗
PubMed2001

Spousal bereavement--implications for health.

BACKGROUND: Bereavement is a potential medical problem as it has implications for health through possible associations with morbidity and mortality. OBJECTIVE: The aim of the present study was to ascertain if spousal bereavement is associated with physical and psychological parameters of illness. METHODS: A spousal bereavement register was created at a village general practice in the West Midlands of 122 spouses (4.9% of the practice population). After exclusion of 22, a sample of 100 had their medical records analysed for the periods of 12 months before and after bereavement. RESULTS: Between these two periods, the average number of consultations increased from 5.99 to 7.60 (P = 0.01), where the vast majority were for physical illness. Mean number of prescriptions increased from 8.54 to 9.15 per patient (P = 0.8) for physical illness and from 0.76 to 1.34 (P = 0.09) for psychological illness. CONCLUSION: Bereavement can be viewed as a medical problem, but this is not borne out in prescribing and so care should be taken not to over-medicalize grief.

Adaptation, Psychological↗
PubMed1999

The relationship between cyclooxygenase-2 expression and colorectal cancer.

CONTEXT: Epidemiological studies have implicated the inducible form of cyclooxygenase (COX-2) in the pathogenesis of colorectal cancer; however, its role is not fully understood. OBJECTIVE: To examine the relationship between the expression of COX-2 in human colorectal cancer and patient survival. DESIGN: Patients diagnosed as having colorectal cancer were evaluated and followed up for up to 9.4 years (median follow-up, 2.7 years). Tumor sections were stained for COX-2 using a rabbit polyclonal antibody raised against human COX-2. The extent of COX-2 staining was graded by 2 observers blinded to outcome. Preabsorption of the anti-COX-2 antibody with a COX-2 peptide abolished the staining, demonstrating the specificity of the assay. SETTING: Gastrointestinal unit of a large general teaching hospital in Dublin, Ireland. PARTICIPANTS: Seventy-six patients (median age, 66.5 years) with colorectal cancer (Dukes tumor stage A, n = 9; Dukes B, n = 30; Dukes C, n = 25; Dukes D, n = 12) whose diagnosis was made between 1988 and 1991. Fourteen normal colon biopsies were stained for COX-2 as controls. MAIN OUTCOME MEASURES: Survival in years following diagnosis compared by extent of COX-2 epithelial staining (grade 1, <1%; grade 2, 1%-19%; grade 3, 20%-49%; grade 4, > or = 50%), Dukes stage, tumor size, and lymph mode metastasis. RESULTS: COX-2 was found in tumor epithelial cells, inflammatory cells, vascular endothelium, and/or fibroblasts. The extent of epithelial staining was heterogeneous, varying markedly among different tumors. Normal tissue adjacent to the tumors also stained weakly for COX-2. No COX-2 was detected in control tissue samples. The Kaplan-Meier survival estimate was 68% in patients who had grade 1 tumor epithelial staining compared with 35% in those with higher grades combined (log-rank chi2 = 5.7; P = .02). Greater expression of COX-2 correlated with more advanced Dukes stage (Kendall tau-b, 0.22; P = .03) and larger tumor size (Kendall tau-b, 0.21; P = .02) and was particularly evident in tumors with lymph node involvement (Kendall tau-b, 0.26; P = .02). CONCLUSIONS: Our data indicate that COX-2 expression in colorectal cancer may be related to survival. These data add to the growing epidemiological and experimental evidence that COX-2 may play a role in colorectal tumorigenesis.

Aged↗
PubMed1998

Fulminant colitis in inflammatory bowel disease: detailed pathologic and clinical analysis.

PURPOSE: The morphologic features of fulminant colitis may be nonspecific, making differentiation between ulcerative colitis and Crohn's disease difficult, even after colectomy. The aims of this study were 1) to identify histologic features that accurately differentiated ulcerative colitis, Crohn's disease, and indeterminate colitis in fulminant colectomy specimens; 2) to determine how frequently subsequent clinical course altered the pathologic diagnosis; and 3) to evaluate the natural history of histologically diagnosed indeterminate colitis. METHODS: Ninety-five fulminant colectomy specimens were evaluated, of which 85 had an original diagnosis of fulminant inflammatory bowel disease. Complete pathologic material and comprehensive clinical follow-up information was available on 67 cases of inflammatory bowel disease. These were re-evaluated in a blinded fashion, and histopathologic features were compared with the original diagnosis and reviewed in the light of subsequent clinical behavior to reach a final diagnosis. RESULTS: Evaluation of macroscopic features was not helpful in differentiating ulcerative colitis from Crohn's disease. Microscopic examination correctly diagnosed ulcerative colitis or Crohn's disease in only 58 of 67 (87 percent) cases. A further three cases (4 percent) were definitively classified after correlation with clinical data, leaving a residual six cases that were diagnosed as indeterminate colitis. Granulomas and lymphoid aggregates were the two most specific indicators of Crohn's disease. CONCLUSIONS: Histopathologic evaluation alone has limitations in the accurate classification of fulminant inflammatory bowel disease. Histologically diagnosed indeterminate colitis is a heterogeneous group that may include some patients who subsequently prove to have ulcerative colitis or Crohn's disease.

Adolescent↗
PubMed1998

Crohn's colitis: the fate of the rectum.

Previous reports suggest that up to 70% of patients undergoing surgery for Crohn's disease of the large bowel do not have gastrointestinal continuity restored and require a permanent ileostomy. In this study the experience with patients requiring surgical treatment of large bowel Crohn's disease is reviewed with particular reference to the management of the rectum. The records of 19 elective and 25 urgent colonic resections performed for large bowel Crohn's disease in 44 patients (16 males, 28 females; mean age 41 years, range 17-76) between 1983 and 1995 were reviewed. Staged proctectomy was performed in 5 of 12 patients who had colectomy for acute colitis and in one patient who had had an elective colectomy. Permanent ileostomy was required in 72% of patients with acute Crohn's colitis and 84% of patients who had elective surgery for large bowel Crohn's. Over 70% of patients having surgical treatment of Crohn's disease of the large bowel required permanent ileostomy. No cases of cancer developed in patients with retained rectal stumps.

Adolescent↗