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Biomedical subjects

I C Talbot

Publications and source records attributed to I C Talbot.

At least 109 records · Page 6Linked to original sources

Longterm appraisal of the histological appearances of the ileal reservoir mucosa after restorative proctocolectomy for ulcerative colitis.

Between November 1976 and December 1985, 110 patients had restorative proctocolectomy for ulcerative colitis. The histological appearances in the reservoir mucosa were followed up in 60 of 109 survivors over 19-173 months (median 97). The median number of biopsy specimens taken per patient was six with a range of 3-13. These were examined by one pathologist (ICT) unaware of the clinical details using a scoring system previously described to assess the degree of chronic and acute inflammation. There was a significant correlation between the degree of severity of chronic and acute changes (r = 0.6192, p < 0.000001). There was no correlation between the severity of inflammation and the following variables: preoperative duration of disease, presence of cancer or dysplasia in the original operative specimen, extra-alimentary manifestations or the type of reservoir. A significant correlation between severe inflammation and male sex was found (p < 0.035). The 60 patients could be divided into three groups based on the severity and fluctuation of histological inflammation. In group A (n = 27, 45%) chronic changes were minor and acute inflammation was never seen. In group B (n = 25, 42%) chronic changes were more severe and there were transient episodes of acute inflammation. In group C (n = 8, 13%) severe chronic and severe acute inflammation were constantly present. Differentiation of the three groups had clearly occurred within six months from closure of the ileostomy. Patients in group C could be identified on histological criteria within weeks of closure of the ileostomy and were those exclusively at risk of developing chronic pouchitis. Chronic pouchitis never occurred in patients of groups A and B. No case of dysplasia was seen. Histological assessment of the reservoir mucosa with in a few months after closure of the ileostomy seems to define patients who will and who will not subsequently develop pouchitis.

Adolescent↗

Progressive systemic sclerosis of the internal anal sphincter leading to passive faecal incontinence.

Two female patients aged 62 and 44 years with progressive systemic sclerosis and passive faecal incontinence are described. Both had the typical gut motility disorders of dysphagia, heartburn, and constipation. Anorectal physiology tests showed a low resting pressure in both and an absent rectoanal inhibitory reflex in one. In both patients anal endosonography showed a thin internal anal sphincter with changed reflectivity suggestive of fibrosis. In both patients anorectal sensation and pudendal nerve function were normal. Histological examination of the rectum in one patient showed collagenous replacement of the rectal muscularis propria with prominent atrophy of the musculature. This study suggests that the internal sphincter may be selectively affected by progressive systemic sclerosis, which may lead to passive faecal incontinence.

Adult↗

Evidence for adenoma-carcinoma sequence in the duodenum of patients with familial adenomatous polyposis. The Leeds Castle Polyposis Group (Upper Gastrointestinal Committee).

AIMS: To explore the association between duodenal adenoma and carcinoma in patients with familial adenomatous polyposis (FAP). METHODS: A multicentre survey of 1262 patients with FAP yielded 47 cases of duodenal cancer. The association between adenoma and cancer was assessed in these cases. RESULTS: Adenomatous tissue was found within duodenal cancer in 29 of 44 (66%) patients with FAP and in mucosa adjacent to duodenal cancer in 31 of 42 (73%) such patients. Adenomas were found as a component of, or adjacent to, duodenal cancer in 38 of 45 (84%) patients. CONCLUSIONS: These observations support the existence of the adenomacarcinoma sequence in the duodenum of patients with FAP. Factors associated with malignant change included villous histology, moderate or severe dysplasia, and the presence of stage IV duodenal polyposis.

Adenoma↗

Surveillance of duodenal polyps in familial adenomatous polyposis: progress report.

Familial adenomatous polyposis (FAP) is characterized by the presence of premalignant adenomas of the large and small bowel. Prophylactic colectomy deals with the risk for colon cancer, leaving duodenal cancer as the leading cause of death. Although most FAP patients have duodenal adenomas, only approximately 5% develop duodenal cancer. This study looks at progression of duodenal polyps with time. The outcome of endoscopic surveillance in the duodenum of 70 patients with familial adenomatous polyposis was determined. A mean of 40 months elapsed between endoscopies. Outcome was measured using video comparison and a staging system that includes histological assessment. Duodenal cancer developed in one patient, and was suspected in two others. The stage of duodenal polyposis worsened in another seven patients. When histology was ignored, comparison of video recordings in 52 patients showed a worsening in 21 (40%). In conclusion, further surveillance appears warranted so that patients at high risk for duodenal cancer might receive early treatment. Should slow progression of duodenal polyposis be shown to be associated with low risk, then most patients can be safely offered less frequent endoscopies than hitherto.

Adenomatous Polyposis Coli↗

Radioimmunoscintigraphy with technetium-99m labelled monoclonal antibody, 1A3, in colorectal cancer.

This study of radioimmunoscintigraphy (RIS) was primarily undertaken to determine how the imaging results related to surgical findings. Technetium-99m radiolabelled 1A3, a monoclonal antibody against a columnar cell surface antigen, was used. No adverse effects or thyroid uptake was observed in 127 studies. The 85 primary colorectal cancers were all image positive. In the assessment of recurrent tumour in the abdomen or pelvis, the accuracy was 33/35 (94%), including true-positive findings in some whose serum carcinoembryonic antigen was normal. There was a positive predictive value for abdominal or pelvic recurrence of 92% and a negative predictive value of 100%, at a prevalence of 66%. In those patients whose liver was able to be evaluated, the accuracy was 72/79 (91%). There was a positive predictive value for liver metastases of 88% and a negative predictive value of 93%, at a prevalence of 32%. The simple procedure for labelling antibody with 99mTc and its ready availability allow a completed report to be given within 24 h of the request.

Adult↗

Solitary juvenile polyps: not a marker for subsequent malignancy.

BACKGROUND: Solitary juvenile polyps are considered benign. In contrast, juvenile polyposis is associated with malignancy and poor long-term outcome. Recent reports suggest that solitary juvenile polyps may also undergo both adenomatous and malignant change. The long-term outcome of patients with solitary juvenile polyps is unknown. Patients are treated conservatively and discharged from follow-up. The present study was designed to examine the incidence of cancer and mortality of these patients, comparing their life expectancy with that of the general population. METHODS: The outcome of 82 patients with a solitary juvenile polyp between 1958 and 1982 was examined by life table analysis. Patients were traced through the Office of Population Censuses and Surveys for death and cancer registration. Patients were compared with an age- and sex-matched group of the general population. RESULTS: The relative risk of dying for patients who have previously had a solitary juvenile polyp in comparison with the general population was found to be 0.66 (95% confidence interval, 0.34-1.14). There was only one case of colorectal cancer. CONCLUSIONS: Patients with a solitary juvenile polyp are not at increased risk of dying of or developing colorectal cancer and do not require further follow-up or investigations.

Adenocarcinoma↗

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↗

Primary lymphoma of the small intestine. A clinicopathological study of 119 cases.

Small bowel lymphomas account for 20 to 40% of primary gut lymphomas in Western populations and are among the most common malignant tumours of the small bowel. We studied 119 cases of primary small bowel lymphoma presenting over 4 decades. Two thirds of the patients were men with a peak age incidence in the 7th decade. Common presenting features included abdominal pain, weight loss, small bowel obstruction, and acute abdomen. Tumours were classified using the Kiel European Association for Haematopathology Geneva Workshop scheme and phenotyped on paraffin sections; 66% were B cells, and 34% were T cell. In all cases, the antibodies L26 and polyclonal CD3 reliably distinguished between B- and T-cell tumours. Of the B-cell lymphomas, 62% were diffuse high grade, 20% were low-grade lymphomas of mucosa-associated lymphoid tissue, 11% had both low- and high-grade components, and 7% were other low-grade types. Of the T-cell lymphomas, 83% were high grade, and 49% were enteropathy associated. Most T-cell lymphomas were ulcerated plaques or strictures in the proximal small bowel; B-cell lymphomas tended to be annular or polypoid masses in the distal and terminal ileum. Survival data showed that low-grade B-cell lymphomas had the best outcome and T-cell lymphomas the worst. Adverse prognostic features included perforation, high-grade histology, multiple tumours and advanced stage.

Adolescent↗

Molecular genetic evidence for the delineation of a more severe form of familial adenomatous polyposis which results from fresh mutation.

Familial adenomatous polyposis, an inherited pre-malignant condition, is caused by mutation in the adenomatous polyposis coli (APC) gene at chromosome 5q22. The lifetime risk of carcinoma approaches 100%, with an average age at death from cancer of 40 years, allowing most patients to complete reproduction. Since there is no evidence for a rising incidence, this is at variance with an apparently high mutation rate. We present evidence for the delineation of a severe form, which hitherto has largely been maintained by fresh mutation. An atypically high frequency of loss of heterozygosity at chromosome 5q22 in small adenomas correlated with an early age of onset or malignancy in two patients, both due to fresh mutation. In both cases, the mutation in APC was shown to be a commonly occurring deletion, leading us to postulate the co-existence of a modifying gene.

Adenomatous Polyposis Coli↗

Affinity preparation of a protein inhibitor recognising a cell surface protease.

Epithelial cell surfaces possess a trypsin-like protease, referred to as guanidinobenzoatase (GB). The cytoplasm of these cells contains an extractable protein (I) which recognises the cell surface GB by forming an enzyme-inhibitor complex (GB-I). Rhodamine-agmatine (Rh-Agm) was designed as a red fluorescent probe, directed to the active centre of GB, which can be used to locate cells with GB, employing fluorescence microscopy. Rh-Agm has a high affinity for GB and will displace I from GB-I on the surfaces of cells in frozen sections. Rh-Agm has been used to displace I from immobilised GB-I complexes on the surface of cultured colonic carcinoma cells in an affinity procedure aimed at purifying the inhibitors of GB obtained from cultured carcinoma cells. These inhibitors have been tested on protected frozen sections of normal colon and carcinoma of the colon, the formation of GB-I complexes being followed by a second yellow fluorescent probe which competes for the active centre of GB. The study of the protein-protein interactions to form GB-I has been facilitated by employing two synthetic fluorescent inhibitors of GB with differing affinities for GB and different fluorescent properties. The use of sections of tissue in this study has enabled a sequence of reactions to be carried out on the same cell surface GB, such that reversible inhibition reactions can be quickly demonstrated and recorded by fluorescence microscopy.

Agmatine↗