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Biomedical subjects

R Whitehead

Publications and source records attributed to R Whitehead.

At least 55 records · Page 3Linked to original sources
PubMed1985

Morphometric analysis of gastric dysplasia.

The grading of gastric epithelial dysplasia has been studied by means of computer aided morphometry. Measurements of histological features were made on segments of epithelium from 38 selected cases of dysplasia graded by subjective assessment. The measurements were statistically compared with the subjective scores using discriminant analysis. The measurements were found to provide significant discrimination between all groups. Nuclear size proved to be the main discriminating variable. Prediction of the likely group membership of individual cases was possible using classification equations derived from the discriminant analysis. Classification of the original data set revealed prediction errors which suggested a bias against diagnosis of dysplasia. As a result of this study reliable, repeatable and objective gradings of gastric epithelial dysplasia can be obtained by inexperienced persons with an accuracy approaching that of a skilled pathologist.

Cell Count↗
PubMed1985

Effects of a murine mammary tumor on in vivo and in vitro hemopoiesis.

The effects of an autologous transplanted mammary tumor (RIII-T3) on hemopoiesis in RIII mice are described. Tumor-bearing animals died 30 to 40 days after inoculation and displayed splenomegaly, extreme neutrophilia, and moderately increased monocyte levels in the spleen, peripheral blood, and bone marrow. The precursors of neutrophils and monocytes, granulocyte/macrophage colony-forming cells (GM-CFC) were elevated in the spleen, bone marrow, and peripheral blood. RIII-T3-conditioned medium stimulated bone marrow GM-CFC and caused the myelomonocytic cell line, WEHI-3B, to differentiate in vitro. The conditioned medium did not stimulate erythroid, megakaryocyte, or eosinophil colony formation. When conditioned medium was fractionated, two peaks of activity corresponding to GM-CSF and G-CSF were observed, suggesting that the extreme neutrophilia observed in tumor-bearing animals may result from chronic exposure of the hemopoietic system to these hemopoietic hormones.

Animals↗
PubMed1985

The ultrastructural immunohistochemistry of oncofoetal antigens in large bowel carcinomas.

Seven large bowel carcinomas were examined by light and electron microscopy for the presence of five oncofoetal antigens. Ultrastructural investigations involved a novel method whereby thick sections of gluteraldehyde-fixed material were cut on a vibratome and then labelled using slight modifications of a standard unlabelled antibody-enzyme (PAP) technique, before further processing. Ultrastructural preservation, staining properties and the retention of antigen activity was seemingly better than that achieved by other investigators. Specific, positive labelling for carcinoembryonic antigen (CEA), colon specific antigen (CSA) and pregnancy-specific beta-1-glycoprotein (SP1) was seen in every case. Clear positive labelling for placental alkaline phosphatase (PLAP) and human chorionic gonadotropin (HCG) was seen in two cases. Extracellular labelling was found in areas of cell debris, free lying or in phagocytic cells and on tumour cell brush borders. The pattern of intracellular labelling, however, was different for each antigen and reflected the probable sites of synthesis and release from the cells. Thus CEA, a complex glycoprotein, was localised within the golgi apparatus, small apical cytoplasmic vesicles and mucous droplets in relatively well differentiated tumour cells. CSA, a chemically related glycoprotein, had a similar, but less dense distribution. SP1, by contrast, was localised within basally-located vesicles associated with the ribosomal endoplasmic reticulum and appeared to be released and persist as debris or taken up by phagocytic cells below the basal lamina. PLAP and HCG, both proteins, were found within simple single membrane-bound vesicles within relatively undifferentiated cells.

Adenocarcinoma↗
PubMed1985

Morphometric assessment of reflux oesophagitis in fibreoptic biopsy specimens.

The oesophageal epithelium of patients with reflux oesophagitis has been studied by means of computer aided morphometry. Measurements of histological features were made on biopsies from six cases before and after treatment. The size and elongation of the nuclei and their variation, the number of nuclei per unit length or per unit sectioned area, and the size and number of nucleoli per nucleus were measured for two zones of the epithelium, the base layer and the intermediate layer, which were independent of section orientation. The measurements were analysed using discriminant analysis. Significant discrimination was found between the two groups. The most important parameters were the number of intermediate layer nuclei per sectioned square millimetre, the mean intermediate layer nuclear area, and the number of nuclei per millimetre of base epithelium. These parameters are consistent with increased cell turnover of the non-ulcerated epithelium before treatment.

Anti-Ulcer Agents↗
PubMed1985

Ploidy studies in adenomatous polyps of the colon.

The nuclei of colonic adenomatous polyps and some colonic carcinomas have a normal diploid profile. The remaining carcinomas are aneuploid, and this change most probably occurs after the dysplasia that determines invasiveness, because even adenomatous polyps with carcinoma in situ are diploid.

Adenocarcinoma↗
PubMed1985

Forms of colitis--a review of recent developments.

Recent advances in the accessibility of the bowel and in techniques for the study of colonic pathology have resulted in descriptions of several forms of colitis which were previously unrecognized and in elucidation of the etiology of previously described but poorly understood entities. Present knowledge of antibiotic-associated colitis, colitis indeterminate, acute self-limited colitis, collagenous colitis and the colitis of food allergy is reviewed.

Adult↗
PubMed1983

The cellular response to human colonic neoplasms: macrophage numbers.

Tumour cells and macrophages are thought to interact and the behaviour of tumours may be modified by macrophage activity. Using an immuno-histochemical method for the demonstration of lysozyme and a computerised image analysis system, the number of macrophages was assessed in and around tubulovillous adenomas and the different Dukes grades of adenocarcinomas of the colon. No significant differences were demonstrated and it is concluded that the behaviour of these neoplasms is not related to the number of associated macrophages.

Adenocarcinoma↗
PubMed1983

Tumour marker acquisition in the polyp-to-cancer sequence in the colon.

Sequential studies of 6 tumour markers in an adenomatous polyp which eventually metastesized as adenocarcinoma are described. The findings suggest that with the development of malignancy, clones of cells with an increasing number of markers are favoured for continued growth and that this probably represents progressive gene derepression.

Adenocarcinoma↗
PubMed1982

Cimetidine in the management of symptomatic patients with duodenitis: a double-blind controlled trial.

Twenty-one adult outpatients with dyspepsia and endoscopically proven duodenitis without chronic ulceration completed a double-blind trial of either cimetidine (1 g/day) or placebo. Treatment with cimetidine for 6 weeks resulted in a significant improvement in symptoms and in the endoscopic appearance of the duodenitis when compared to treatment with placebo. The symptomatic and endoscopic improvement, however, was not associated with any significant change in the histological grading of the duodenitis.

Cimetidine↗
PubMed1982

Tumor markers in carcinoma and premalignant states of the stomach in humans.

Tissue sections taken from areas of carcinoma, areas of intestinal metaplasia in stomachs bearing carcinoma are areas of intestinal metaplasia in stomachs showing atrophic gastritis only were examined for eight markers: a tumour-derived colon-specific antigen (tCSA), carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), pregnancy-specific beta-glycoprotein 1 (SP1), human placental lactogen (HPL), human beta chorionic gonadotrophin (beta-HCG), transferrin (TF) and ferritin (FE). In terms of the number of markers demonstrated in each of the three categories, there is a close similarity between the cells of adenocarcinoma and cells of intestinal metaplasia in cases of cancer, but not to similar metaplastic cells in atrophic gastritis cases. In addition, it appears that the presence of tCSA and SP1 is closely linked to carcinoma, though only approximately half of such cases contain these markers. It would also appear that there are two types of morphologically identical intestinal metaplasia, one related to cancer, the other not. No difference was found between so-called intestinal type and diffuse-type carcinomas.

Adenocarcinoma↗
PubMed1981

Tumor-associated antigens in polyps and carcinoma of the human large bowel.

The presence of a number of tumor-associated antigens was studied in eight metaplastic polyps, 22 tubulovillous adenomas, and 20 carcinomas. Specific tumor antigens were identified using the immunohistochemical (P.A.P.) technique to detect carcinoembryonic antigen (CEA), human placental lactogen (HPL), alphafetoprotein (AFP), colon-specific antigen (CSA), pregnancy-specific beta lipoprotein 1 (SP1), human beta chorionic gonadotropin (beta hCG), and placental alkaline phosphatase (P Alk P), isoferritins (FE), and transferrin (TF). There is no difference in either the number of antigens present or the number of cases positive for each antigen in cancers and tubulovillous adenomas, but the majority of metaplastic polyps show only CEA and HPL positivity. The two metaplastic polyps showing a full range of positivity were atypical and over 5 mm in diameter. The findings have shown a remarkable similarity between polyps and cancer, which strengthens the concept of the relationship between adenomatous polyps and carcinoma of the colon.

Adenoma↗
PubMed1981

Carcinoplacental alkaline phosphatase in malignant and premalignant conditions of the human digestive tract.

The presence of carcinoplacental alkaline phosphatase (CP Alk P) was demonstrated in the cells of malignant and premalignant states of the human stomach, colon and rectum using the immunoperoxidase technique. It was shown to be present in 7 out of 18 carcinomas of stomach and 7 of 17 cases of carcinoma of colon and rectum. In the putative premalignant states it was demonstrated in 4 of 15 cases of intestinal metaplasia associated with gastric carcinoma, and 9 of 12 tubulovillous adenomas of colon. However, it was also demonstrated in 5 of 8 metaplastic polyps of colon which are not neoplastic and in 9 of 17 cases of intestinal metaplasia not associated with cancer of the stomach. It was not seen in normal gastric mucosa and only faintly in 1 of 11 samples of normal colon. CP Alk P has been shown to be a specific marker of malignancy in a wide range of human cancers when studied in sera from patients or in tissue culture of tumour cells. In this study however, although a statistical difference exists between normal and diseased tissue the marker appears as frequently in non-neoplastic states. It is concluded that CP Alk P is, in tissues, a marker of proliferative activity in cells, rather than neoplastic or malignant change. In this respect it is similar in some respects to carcinoembryonic antigen, but not other markers of placental origin such as pregnancy specific beta, glycoprotein.

Adenoma↗
PubMed1980

Hyperaldosteronism associated with liver metastases.

Plasma aldosterone levels were measured in 50 patients with confirmed liver metastases from various histologically proved primary tumors. None of these patients had electrolyte abnormalities or history of benign liver disease, congestive heart failure, hypertension, or renal disease. Patients with edema, ascites, or both had significantly greater elevation of plasma aldosterone levels compared to nonedematous patients; these patients also demonstrated a substantial degree of hepatic dysfunction as evidenced by lower serum albumin levels and higher bilirubin and alkaline phosphatase levels. This study provides a rational basis for the use of the specific aldosterone inhibitor spironolactone in the treatment of patients with advanced metastatic liver disease and edematous states.

Aldosterone↗