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Biomedical subjects

R R Pascal

Publications and source records attributed to R R Pascal.

At least 19 recordsLinked to original sources
PubMed1999

Keratinocyte growth factor enhances glutathione redox state in rat intestinal mucosa during nutritional repletion.

Malnutrition decreases tissue levels of glutathione (GSH), a major endogenous antioxidant that detoxifies reactive oxygen species and promotes cell growth. This study determined the effects of the gut trophic peptide keratinocyte growth factor (KGF) on intestinal mucosal GSH concentrations and redox state in malnourished rats. Adult rats were food-deprived for 3 d, then consumed food ad libitum or 25% of ad libitum intake for 3 d with daily intraperitoneal administration of saline or KGF (5 mg.kg-1.d-1). Mucosal GSH and glutathione disulfide (GSSG) concentrations, crypt depth and total mucosal height were measured in the jejunum, ileum and colon. In the 25% of ad libitum-refed, saline-treated group, mucosal GSH was lower in all gut tissues (42% in jejunum, 38% in ileum, and 57% in colon), and the GSH/GSSG ratio was lower in the jejunum and ileum compared to that in the ad libitum-refed controls. KGF treatment with ad libitum refeeding increased GSH/GSSG in the jejunum, ileum and colon. Furthermore, in 25% of ad libitum refeeding, KGF normalized jejunal, ileal and colonic mucosal GSH content and significantly increased the mucosal GSH/GSSG ratio relative to rats treated with saline. Increased crypt depth and total mucosal height induced by KGF and feeding could be explained in part by increased mucosal GSH content. KGF treatment improved gut mucosal glutathione redox state in malnourished, refed rats. These data provide evidence that gut trophic hormones and food intake may independently support gut mucosal glutathione antioxidant capacity during nutritional repletion.

Animals↗
PubMed1997

Gastric adenocarcinoma and low-grade B-cell lymphoma of mucosa-associated lymphoid tissue.

We describe the synchronous occurrence of gastric signet-ring cell adenocarcinoma and low-grade B-cell lymphoma of mucosa-associated lymphoid tissue in a patient with chronic gastritis and intestinal metaplasia. Histologic features of the mucosal inflammation, a follicular gastritis, were suggestive of a chronic Helicobacter pylori infection. Previous hypotheses concerning the relationship of long-standing gastritis and development of gastric carcinoma and lymphoma are supported by our findings.

Adenocarcinoma↗
PubMed1997

Geographic variations in eosinophil concentration in normal colonic mucosa.

We reviewed 256 mucosal biopsy specimens from the descending and sigmoid colon obtained from surgical pathology departments in several areas of the United States. Only specimens of normal colonic mucosa were included, i.e., no specimens with acute or chronic colitis or adenomatous change, or in which eosinophils invaded the crypts or muscularis mucosae. The mean number of eosinophils per intercryptal space was highest in the southern United States, and there was a 35-fold difference between the mean eosinophil concentrations of patients in New Orleans and Boston. The reason for geographic variation is unknown, but it might be related to allergens in the environment or diet. Normal variations in mucosal eosinophil concentrations should be measured within a specific region before evaluating colonic biopsy specimens for eosinophilia.

Adult↗
PubMed1995

Endoscopically removed malignant colorectal polyps: clinicopathologic correlations.

BACKGROUND/AIMS: Treatment options for patients with endoscopically removed malignant colorectal polyps are polypectomy alone vs. polypectomy followed by surgery. The aim of this study was to define histopathologic parameters that can be used for clinically relevant treatment decisions. METHODS: Five pathologists evaluated 140 polyps for the presence or absence of unfavorable histology. Unfavorable histology was tumor at or near (< or = 1.0 mm) the margin and/or grade III and/or lymphatic and/or venous invasion. Adverse outcome was recurrent and/or local cancer and/or lymph node metastasis. RESULTS: Adverse outcome was 19.7% (14 of 71), 8.6% (2 of 23), and 0% (0 of 46) when unfavorable histology was present, indefinite (lack of agreement), and absent, respectively (P < 0.0005, present vs. absent). Four patients with cancer > 1.0 mm from the margin had an adverse outcome (2 with lymphatic invasion and 2 indefinite for lymphatic invasion). Four patients with negative resections later developed distant metastases. Eight patients (6.3%) died of disease, and 2 of 69 without unfavorable histology (both indefinite for lymphatic invasion) had an adverse outcome. Interobserver strength of agreement was substantial to almost perfect for margin, grade, and venous invasion and fair to substantial for lymphatic invasion. CONCLUSIONS: This system is usable clinically. Patients with unfavorable histology are probably best managed by resection postpolypectomy, whereas in the absence of unfavorable histology, they probably can be treated by polypectomy only.

Colonic Polyps↗
PubMed1994

Dysplasia and early carcinoma in inflammatory bowel disease and colorectal adenomas.

The control of colorectal cancer is currently dependent on early detection, and its prevention requires the recognition and treatment of its precursor lesions. The adenoma has been established as the precursor of colorectal carcinoma in the general population. Among patients with inflammatory bowel disease (IBD), dysplasia is associated with, and precedes, invasive carcinoma. In this section criteria are described for the histological detection of preinvasive and early invasive neoplasia in the large intestine of patients with and without IBD. The therapeutic implications of these diagnoses are stressed. A brief review of subcellular changes, including genetic alterations, in colorectal neoplasia is included.

Adenoma↗
PubMed1989

Primary malignant fibrous histiocytoma of the pancreas.

A patient with a large tumor of the head and body of the pancreas had a Whipple procedure performed after the intraoperative diagnosis of "mesenchymal tumor" was made. The final histopathologic diagnosis was malignant fibrous histiocytoma arising in the pancreas. The patient died of postoperative complications, and no metastatic disease was found at autopsy. This is the first detailed description of a primary pancreatic malignant fibrous histiocytoma.

Adult↗
PubMed1988

Mucinous cystadenoma of the ovary with stromal luteinization and hilar cell hyperplasia during pregnancy.

A 32-year-old woman was delivered of a healthy, full-term infant by cesarean section, at which time a large ovarian cyst was removed. The cyst proved to be a mucinous cystadenoma with prominent luteinization of the stroma subtending the epithelium and with numerous foci of hyperplastic Leydig cells in the cyst wall and ovarian hilum. These hormonally induced changes must be recognized in order to avoid mistaking them for invasive epithelial components.

Adult↗
PubMed1988

Metaplastic breast carcinoma with epithelial phenotype of pseudosarcomatous components.

A case of metaplastic breast carcinoma was subjected to an immunohistochemical study to characterize its apparent fibrosarcomatous and chondrosarcomatous elements. Polyclonal and monoclonal antibodies against epithelial cell components such as keratin proteins, epithelial membrane antigen, membrane and cytoplasmic antigens of human mammary carcinoma cells, and carcinoembryonic antigen were used, as well as antibodies against the mesenchymal antigens, desmin, and vimentin. The cells with a mesenchymal appearance had an epithelial derivation, as shown by the presence of epithelial cell markers and absence of mesenchymal cell markers.

Breast Neoplasms↗
PubMed1987

Mucoepidermoid (adenosquamous) carcinoma arising in Barrett's esophagus.

A case of mucoepidermoid or adenosquamous carcinoma arising from the mucous epithelium of a Barrett's esophagus is presented. Immunohistologic examination demonstrated carcinoembryonic antigen (CEA) in both the glandular and squamous components, but keratin only in the latter. Although mucoepidermoid carcinoma of the esophagus is believed to arise from submucosal glands, heterotopic gastric surface epithelium may also give rise to this uncommon neoplasm.

Adenocarcinoma↗
PubMed1986

Immunohistologic detection of estrogen receptors in paraffin-embedded breast cancers: correlation with cytosol measurements.

Paraffin-embedded sections of 76 human breast tissue specimens were analyzed for estrogen receptors (ER) and endogenous bound estrogen (ER-E). Preincubation of sections with polyestradiol phosphate was followed by stabilization of the complex with glutaraldehyde. The bound hormone was then visualized by the peroxidase-antiperoxidase (PAP) technique with antiestradiol as the primary antiserum. Normal breast tissue and benign proliferations were consistently positive for ER and ER-E. All specimens were examined for free and bound receptors in cytoplasm and nuclei. Among the carcinomas examined, a high correlation was found between the presence of ER by the PAP method and by the biochemical analysis of cytosol preparations. The PAP method, requiring no special preparation of surgical specimens, overcomes many of the disadvantages of the cytosol method and adds the advantage of independent evaluation of nuclear and cytoplasmic estrogen binding sites.

Breast Neoplasms↗
PubMed1985

CEA tissue staining in colorectal cancer patients. A way to improve the usefulness of serial serum CEA evaluation.

The evaluation of serial plasma carcinoembryonic antigen (CEA) levels is one of the most important parameter used to establish the prognosis of surgically cured colorectal cancer patients. Carcinoembryonic antigen is particularly useful in the identification of recurrences and metastasis. However, to improve the usefulness of this assay, it would be helpful to accurately determine, if possible, those patients whose cancers produce CEA. The evaluation of the presence of CEA in these cancer specimens by means of immunoperoxidase staining technique does seem to improve the sensitivity of the CEA test. Fifty-seven patients with colorectal cancer who underwent surgical treatment were studied. Tissue CEA evaluation was correlated with the plasma CEA levels, the pathologic stage and grade, and histologic type of the cancers. Results demonstrate that 66.6% of Dukes' B cancers, 78.9% of Dukes' C, and 77.7% of Dukes' D cancers stained positively for CEA by immunoperoxidase. Thirty of 57 patients with preoperative pathologic plasma CEA levels had positive tissue CEA, whereas 8/57 patients did not. Of patients with a well-differentiated cancer (G1), 81.4% had positive tissue CEA versus the 64% of G2 and 60% of G3 cancers. The authors conclude that the use of the immunoperoxidase stain to measure CEA in tissue, so that the CEA serum assay may be used in those patients known to produce CEA, results in a major increase in the sensitivity of the test.

Adenocarcinoma↗
PubMed1985

Hemorrhagic pancreatitis: a complication of transcatheter embolization treated successfully by total pancreatectomy.

Since pancreatitis can be produced experimentally in dogs by embolization of microspheres into the pancreatic arterial circulation, there has been speculation that intentional or inadvertent embolization of the pancreas in human subjects could also produce pancreatitis. Although such therapeutic embolization has increased, no pathologically documented case of this complication has been recorded. We have reported the first such case occurring in a patient with a large, highly vascular, nonfunctioning islet cell carcinoma of the tail of the pancreas preoperatively embolized with Gianturco coils and Gelfoam particles suspended in sodium tetradecylsulfate solution to facilitate distal pancreatectomy. The resultant hemorrhagic pancreatitis and duodenal necrosis required a total pancreatectomy. We conclude that, by itself, occlusion of the origin of the splenic and gastroduodenal arteries with coils would have been effective and without complication; however, the addition of Gelfoam particles in a sclerosing solution reduced the microscopic pancreatic circulation to a critical point and resulted in hemorrhagic pancreatitis.

Adenoma, Islet Cell↗