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Y Dayal

Publications and source records attributed to Y Dayal.

At least 19 recordsLinked to original sources
PubMed1995

Pancreatic metaplasia in Barrett's esophagus. An immunohistochemical study.

While pancreatic metaplasia has been observed in gastric mucosa of patients with chronic gastritis, it has not been described in ectopic gastric mucosa. We have identified focal clusters of cells resembling pancreatic acinar cells (CPACs) in 11 of 350 biopsies of Barrett's mucosa from 120 patients with Barrett's esophagus enrolled in a clinical efficacy trial of omeprazole versus ranitidine for treatment of gastroesophageal reflux disease. Three additional cases from our surgical files were also studied. Immunoreactivity for trypsin and chymotrypsin was present in the CPACs of all 14 cases, while stains for alpha-amylase and lipase were each positive in 12 of 13. A few cells in the CPACs were also positive for chomogranins (12 of 13 cases), serotonin (seven of 13 cases), somatostatin (three of 12), gastrin (four of 11), and pancreatic polypeptide (two of 13). No staining was seen for insulin or glucagon. Ultrastructural studies performed in one case showed features of pancreatic exocrine and endocrine (PP-type) cells in cells within CPACs. These results collectively indicate that the CPACs are aggregates of true pancreatic acinar cells admixed with a few endocrine cells. This pancreatic parenchyma in Barrett's mucosa is most likely of metaplastic origin and could be derived from the transitional zone cells or from pluripotent stem cells in the esophageal mucosa or from metaplasia of mucus cells. While the development of pancreatic metaplasia in Barrett's esophagus appears to be unrelated to drug therapy, the clinical relevance of this distinctive histological finding needs further investigation.

Adolescent↗
PubMed1992

Folate deficiency enhances the development of colonic neoplasia in dimethylhydrazine-treated rats.

In patients with ulcerative colitis, epidemiological work has suggested an association between low folate status and an increased risk of colonic neoplasia. The aim of the present study was to determine if experimental folate deficiency increases the likelihood of developing neoplasia in rats treated with the carcinogen dimethylhydrazine. Weanling male Sprague-Dawley rats were fed with an amino acid-defined diet containing either 8 or 0 mg/kg folic acid. After 5 weeks of defined diet, weekly s.c. injections of dimethylhydrazine (20 mg/kg) were administered to both groups. Serum, whole blood, liver, and colonic folate concentrations at the time of sacrifice were significantly lower in folate-depleted animals (P less than 0.001). There were significant differences in the incidence of colonic neoplasia between the two groups after 20 weeks of dimethylhydrazine exposure: folate-deficient rats had a greater incidence of dysplasia (6 of 7 versus 2 of 7 animals; P less than 0.05) and carcinoma (6 of 7 versus 1 of 7 animals; P less than 0.01). Furthermore, a significantly greater proportion of folate-replete rats than folate-deficient rats were free of neoplastic lesions (5 of 7 versus 0 of 7 animals; P less than 0.05). These results suggest that, in this animal model, folate deficiency increases the risk of malignancy when there is an underlying predisposition to colorectal cancer.

Animals↗
PubMed1991

The cell-mediated response to schistosomal antigens at the clonal level. In vivo functions of cloned murine egg antigen-specific CD4+ T helper type 1 lymphocytes.

It is now well established that the granulomatous inflammation surrounding the eggs of Schistosoma mansoni is mediated by Th lymphocytes. Our laboratory has recently cloned murine CD4+ Th cells specific for schistosomal egg Ag (SEA). In the current study, SEA-specific IL-2-producing Th1 clones were tested for their ability to mediate local delayed-type hypersensitivity (DTH) reactions, as well as granuloma formation in vivo. Marked delayed-onset erythema and induration developed in footpads of normal syngeneic hosts injected with SEA together with SEA-specific Th1 clones. Histologic examination of these lesions revealed typical, predominantly mononuclear, cell infiltrates characteristic of DTH reactions. Conversely, no reactions were observed in allogeneic hosts, in the absence of SEA, or with the use of a control Th1 clone. Moreover, adoptive transfer of cloned SEA-specific Th1 cells to normal syngeneic mice mediated, in 4 days, the formation of vigorous granulomas around schistosomal eggs embolized in the lungs. Such granulomas, which were quantitated by computer-assisted morphometric analysis, were comparable in size to those elicited by lung-embolized eggs in SEA/CFA-immunized mice. In contrast, significantly smaller granulomas were observed in normal recipients of eggs plus a control Th1 clone or of eggs alone. Our data indicate that Ag-specific, MHC-restricted, local DTH reactions, as well as egg granuloma formation in vivo, can be mediated by monoclonal SEA-specific Th1 cells. They suggest that T cell sensitization to only small numbers of SEA determinants may be sufficient to elicit the hepatointestinal granulomatous inflammation associated with schistosomiasis.

Animals↗
PubMed1991

Propranolol ameliorates the development of portal-systemic shunting in a chronic murine schistosomiasis model of portal hypertension.

We investigated the role of early portal hypotensive pharmacotherapy in preventing the development of portal-systemic shunting in a portal hypertensive model of chronic murine schistosomiasis induced by infecting C3H mice with 60 cercariae of Schistosoma mansoni. Propranolol was administered in drinking water to 20 animals for a period of 6 wk at a dose of 10 mg.kg-1d-1, starting at 5 wk of schistosomal infection. 32 age-matched mice with chronic schistosomal infection served as controls. All animals were studied 11 wk after the infection. Compared with controls the portal pressure (10.8 +/- 0.40 mmHg) was significantly lower (P less than 0.001) in the propranolol-treated animals (7.9 +/- 0.80 mmHg). Portal-systemic shunting was decreased by 79%, from 12.2 +/- 3.34% in controls to 2.5 +/- 0.99% in the propranolol group (P less than 0.05). Portal venous inflow was reduced by 38% in the propranolol treated animals (2.50 +/- 0.73 ml/min; n = 6) compared with controls (4.00 +/- 0.34 ml/min; n = 8; P less than 0.05). The worm burden, the granulomatous reaction, the collagen content of the liver, and the serum bile acid levels were not significantly different between the two groups of animals. These results demonstrate that in chronic liver disease induced by schistosomiasis, the development of portal-systemic shunting can be decreased or prevented by the reduction of flow and pressure in the portal system.

Animals↗
PubMed1991

Distinctive unclassified mesenchymal tumor of the digit of dogs.

Four examples of a mesenchymal tumor of undetermined histogenesis occurred in three mixed-breed dogs and one Yorkshire terrier. All tumors occurred as solitary, soft to firm, solid, tan, and ulcerated masses in the digits of dogs aged 11 to 15 years. The compact cellular tumor had cells with anisokaryotic round, oval, or irregular nuclei, some of which were multinucleated. The neoplastic cells appeared to arise in the tissue near the third phalanx in the area of dense collagenous trabeculae located proximal to the fat pad and sweat glands. The unclassifiable cells had some features of histiocytes by transmission electron microscopy, but failed to stain for lysozyme and alpha-1-antichymotrypsin, markers for monocyte-macrophage derived cells. Immunohistochemically, the cells stained for vimentin but not for cytokeratins, desmin, S-100 protein, epithelial membrane antigen, alpha-lactalbumin, lysozyme, alpha-1-antichymotrypsin, alpha-lactalbumin, casein, and heavy and light chain immunoglobulins. The combined findings of light and transmission electron microscopy and immunohistochemistry exclude tumor histogenesis from an epithelial cell, melanocyte, mast cell, plasma cell, Schwann cells, and Merkel cell.

Animals↗
PubMed1990

A randomized phase II study of acivicin and 4'deoxydoxorubicin in patients with hepatocellular carcinoma in an Eastern Cooperative Oncology Group study.

We analyzed 56 of 75 previously untreated patients with hepatocellular carcinoma who entered on a prospectively randomized trial of acivicin versus 4'deoxydoxorubicin (esorubicin). At least one episode of severe toxicity was documented in 23% of the patients on acivicin and 45% of those on 4'deoxydoxorubicin. Two patients responded to 4'deoxydoxorubicin. One response was partial, lasting 58 weeks, and one was complete, lasting more than 4 years. The 90% confidence interval for response is 1-20%. In view of a 45% rate of severe or worse toxicity with 4'deoxydoxorubicin, this drug cannot be recommended as treatment. There were no responses on acivicin.

Antibiotics, Antineoplastic↗
PubMed1990

Cutaneous metaplastic synovial cyst.

Metaplastic synovial cyst, a recently described entity, is histologically characterized by a cystic cavity lined by metaplastic synovial tissue that is often hyperplastic and protrudes into its lumen as villous structures. Clinically, these lesions resemble suture granuloma and develop at the site of previous surgical trauma. We have studied 4 cases of this unusual entity and have investigated the immunohistochemical profile in an effort to determine the nature and derivation of their lining tissue. One of our cases is unique since the lesion was associated with a basal cell carcinoma. A history of previous surgery was noted in one, and history of trauma in 2 of the 4 cases. Our immunohistochemical observations confirmed a mesenchymal derivation for the "synovial like villous structures" but non-availability of a specific "synovial" marker does not permit us to conclude with certainty the synovial nature of the metaplastic tissue. Cutaneous metaplastic synovial cysts are unique lesions which deserve attention and should be included in the differential diagnosis of cutaneous cysts.

Adult↗
PubMed1989

Orbital myositis and giant cell myocarditis.

A 65-year-old woman developed progressive, bilateral ophthalmoplegia, with thickened extraocular muscles on CT. One month later, a cardiac arrhythmia led to her death. Pathologically, the extraocular and skeletal muscles showed diffuse mononuclear cell inflammation, while the heart contained granulomatous myositis. This patient's syndrome of idiopathic, orbital myositis and giant cell myocarditis may be a distinct nosologic entity.

Aged↗
PubMed1988

Pancreatic cholera syndrome due to a vasoactive intestinal polypeptide-producing tumor: further insights into the pathophysiology.

This case report describes a patient with pancreatic cholera caused by a vasoactive intestinal polypeptide-producing pancreatic tumor. The case presents several unusual characteristics of this disease. The primary tumor was a mucinous adenocarcinoma of the pancreas. The serum vasoactive intestinal polypeptide level of 2400 pmol/L is the highest reported. At this vasoactive intestinal polypeptide level, the somatostatin analogue SMS 201-995 at doses up to 2 mg/24 h did not control the 21 L/24 h stool output. Fecal incontinence due to a manometrically documented hypotonic internal anal sphincter occurred. Using surgically created stomas, the segmental gastrointestinal fluid and sodium losses were shown to be greatest from the jejunum, whereas potassium losses from the colon and small intestine were equal. The cellular mechanism for the small intestinal potassium secretion is not known.

Adenoma, Islet Cell↗
PubMed1988

Multiple dental follicles with odontogenic fibroma-like changes (WHO type).

A 15-year-old boy, in the case presented in this article, had 13 unerupted teeth, each associated with hyperplastic pericoronal tissue that showed histologic features suggestive of the WHO type of odontogenic fibroma. The etiology, clinical features, radiographic findings, and histopathology of the odontogenic fibroma are reviewed. It is suggested that the unusual pericoronal findings represent a hamartomatous change.

Adolescent↗
PubMed1988

Gastrin: levels and trophic action during advancing age.

Changes in antral and serum gastrin levels as well as gastrin (G) and somatostatin (D) cell density were examined in 4- to 16-mo-old Fischer-344 rats. In these rats, the responsiveness of the gastric mucosa to the trophic action of gastrin was also examined. It was observed that whereas serum gastrin levels declined steadily between 4 and 16 mo of age, antral gastrin levels rose sharply during this period. In the antrum of 16-mo-old rats, the density of G-cells, but not D-cells, was found to be lower than in their 4-mo-old counterparts. Thus, when D- to G-cell ratios were calculated, 16-mo-old rats revealed a 50% higher D- to G-cell ratio than the 4-mo-old animals. To assess the trophic action of gastrin, groups of 4-, 8-, and 16-mo-old rats were infused subcutaneously (osmotic minipump) with either saline or gastrin (G-17-I; 250 ng.kg-1.h-1) for 14 days. The gastric mucosa was assayed for thymidine kinase (an indicator of proliferative activity) and DNA and protein content. In the saline-infused rats, gastric mucosal thymidine kinase activity increased sharply between 4 and 16 mo of age without significantly affecting DNA or protein content (expressed as milligrams per 100 g of body weight), suggesting that the age-associated rise in proliferative activity is not accompanied by increased mucosal growth.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1988

Histopathological classification of nonantral gastric endocrine growths in man.

Recently, the gastric endocrine system has been recognized as the origin of benign and malignant tumors in pernicious anemia. It has also been found that the gastric endocrine cells respond to permanent elevation of serum gastrin levels induced by changes in acid secretion in response to surgical procedures, drug therapy and age. Therefore, a definition of nonantral gastric endocrine hyperplasia (simple or diffuse, linear or chain-forming, micronodular, adenomatoid), dysplasia (enlarging or fusing micronodules, microinvasion, nodular growth) and neoplasia (intramucosal carcinoid, invasive carcinoid) is presented. The individual entities are illustrated, together with the literature discussed and the techniques for their identification presented.

Endocrine System Diseases↗
PubMed1988

Symmetrical partial lateral 'cryptophthalmos'. A new concept of its embryological pathogenesis.

A unique case of bilateral, partial cryptophthalmos is described, with no associated systemic anomalies. There were symmetrical, well-developed palpebral apertures medially with small conjunctival sacs, and symmetrical hemicryptophthalmos laterally. A faint groove extended temporally over the fused lids on both sides. There was a distinct plane of cleavage laterally between the disorganized microphthalmic globes and overlying tissues. The surgical observations are detailed.

Eye↗
PubMed1987

The distribution of immunoreactive chromogranins, S-100 protein, and vasoactive intestinal peptide in compound tumors of the adrenal medulla.

Three adrenal medullary tumors that showed admixtures of pheochromocytomatous elements with ganglioneuroma or ganglioneuroblastoma were studied to determine the distribution of immunoreactive chromogranins, S-100 protein, and vasoactive intestinal peptide (VIP). Two tumors consisted of typical pheochromocytoma cells admixed with mature-appearing ganglioneuroma. The third consisted of pheochromocytoma admixed with ganglioneuroblastoma and contained many immature and cytologically atypical cells. In all cases, chromogranin staining was absent or weak in neuronal perikarya and moderate to intense in varicosities of neuronal processes, a finding consistent with the presumed distribution of secretory granules in neurons. Chromogranin staining was also intense in chromaffin cells. Glial cells that stained for S-100 were randomly scattered among chromaffin cells but accumulated in areas with neuronal processes. Weak staining for VIP was present in neuronal cells in one of the two tumors with ganglioneuromatous features. Intense staining for VIP occurred in the third tumor in both neuronal and apparently nonneuronal cells. We conclude that granule distribution and cell-cell interactions for specific cell types in compound tumors tend to mimic those in normal adrenal medulla and sympathetic ganglia. Although immunoreactive VIP was localized exclusively to neurons in one tumor, as in normal tissues, patterns of staining for VIP across tumors are less predictable.

Adrenal Gland Neoplasms↗
PubMed1987

Hyperplastic lesions of the gastrointestinal endocrine cells.

A substantial body of knowledge is presently available on the morphologic, histochemical, ultrastructural, and functional characteristics of both the normal endocrine cell population of the gut and their related endocrine tumors. In contrast to this, we have only recently begun to recognize the existence of hyperplastic proliferations of various endocrine cell types, and information is therefore steadily accumulating on the morphologic criteria for their recognition, their clinicopathologic correlates and the clinical relevance of this morphologic finding. Hyperplastic proliferations of various endocrine cell types most often develop as a secondary phenomenon in a variety of clinical situations, and may modify the clinical course of the associated condition in a manner that underscores the functional interrelationships these endocrine cells have not only with each other but with other cell types as well. However, similar proliferations may also occur as a primary event (e.g. primary antral G-cell hyperplasia) and give rise to clinical and biochemical features attributable to the overproduction of their specific hormonal product (e.g. Zollinger-Ellison Syndrome, type I). This communication provides a broad overview of the current state of our knowledge of hyperplastic lesions of a variety of gut endocrine cell types in humans, their pathophysiologic significance, their relationship (if any) to the subsequent development of endocrine tumors (i.e. the hyperplasia-neoplasia sequence), and the utility of certain experimental models for the study of such proliferations in a variety of animal species.

APUD Cells↗
PubMed1987

The role of immunohistochemistry in the diagnosis of poorly differentiated malignant neoplasms.

The development and refinement of immunohistochemical methodologies over the past decade has had a major impact in many different areas of diagnostic pathology. The generation of increasing numbers of well-characterized polyclonal antisera and monoclonal antibodies directed to a variety of antigenic determinants has made the phenotyping of neoplasms a reality. The results of such immunohistochemical analyses have provided an important starting point for the further workup and management of patients with undifferentiated or poorly differentiated malignant neoplasms of unknown origin. It should also be apparent, however, that the results of immunohistochemical analyses in such clinical settings are subject to a large number of variables and that these procedures must be controlled rigorously. The results of extensive performance testing, particularly with new reagents, must be available in order to establish their specificities and sensitivities under different conditions of tissue fixation and processing. Such studies not only will establish more precise and reproducible diagnostic criteria but also will be important for the definition of new clinical and pathological entities and for the characterization of novel prognostic parameters.

Antibodies, Monoclonal↗
PubMed1987

Zollinger-Ellison syndrome. Cure by surgical resection of a jejunal gastrinoma containing growth hormone releasing factor.

Zollinger-Ellison syndrome developed in a 46-yr-old woman due to a gastrinoma originating in the proximal jejunum. Resection of the tumor and adjacent lymph nodes containing metastatic carcinoma resulted in prompt reversal of all clinical and biochemical abnormalities, and she remains well 42 mo after surgery. To our knowledge, this patient is one of the first well-documented cases of primary jejunal gastrinoma causing the Zollinger-Ellison syndrome. The tumor contained numerous cells positive for gastrin and smaller numbers positive for serotonin, somatostatin, or bovine pancreatic polypeptide, as diagnosed by immunohistochemistry. In addition, a small subset of tumor cells was positive for growth hormone releasing factor. Our case is the first to document the presence of this neuropeptide in an enteric gastrinoma.

Female↗