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D G Sheahan

Publications and source records attributed to D G Sheahan.

At least 19 recordsLinked to original sources
PubMed1999

Evaluation of gastric biopsies for neoplasia: differences between Japanese and Western pathologists.

Cited variations in the evaluation of gastric endoscopic biopsies for neoplasms between pathologists in Japan and those in the United States and Europe (the West) may have stemmed from several causes. The five-tiered group classification of the Japanese Research Society for Gastric Cancer (JRSGC) for interpretation of biopsies is not used in the West. Some differences may also exist in the morphologic criteria to reach a diagnosis of dysplasia or carcinoma. The goals of this study were to test the Western and Japanese classifications of gastric dysplasia and adenocarcinoma and to assess the differences between four Japanese and seven Western pathologists. One hundred biopsies, 20 from each of the five categories of the JRSGC scheme as determined by one observer, were collected. The Japanese observers used the JRSGC system, expressed in Roman numerals, whereas Western pathologists used a five- or six-tiered scheme expressed in diagnostic terms. Pairwise agreement was evaluated using k statistics within both groups. Consensus diagnosis on each biopsy was accepted as the opinion of the majority. The sensitivity and specificity of each reviewer for a certain diagnosis were also assessed. The intragroup agreements were moderate for both the Japanese (mean k = 0.663) and the Westerners (mean k = 0.652). The pairwise agreements between Japanese and Western observers were low (mean k = 0.542). Overall, the sensitivity was low for all Japanese observers for the diagnosis of dysplasia (38.7% vs 92.5%), and the sensitivity for the diagnosis of adenocarcinoma was high in both groups but higher among the Japanese observers (93.9% and 85.2%, respectively). Overall, the Japanese-Western interobserver agreement was moderate. The JRSCG scheme did not translate into higher interobserver agreement among Japanese observers. The sensitivity for the diagnosis of gastric adenocarcinoma was high for both groups, but the specificity was low among the Japanese. The cause seemed to be centered around the diagnosis of dysplasia in the Western system, which was a lesion frequently interpreted as carcinoma in Japan because of the different definitions of carcinoma in each system. Such a discrepancy might be important because it may explain some of the differences in the prevalence and prognosis of early gastric cancer between Japan and the West. An international effort is needed to harmonize morphologic criteria and analyze whether therapeutic consequences may stem from such discrepancies.

Biopsy↗
PubMed1998

Chemotherapy followed by surgery compared with surgery alone for localized esophageal cancer.

BACKGROUND: We performed a multi-institutional randomized trial comparing preoperative chemotherapy followed by surgery with surgery alone for patients with local and operable esophageal cancer. METHODS: Preoperative chemotherapy for patients randomly assigned to the chemotherapy group included three cycles of cisplatin and fluorouracil. Surgery was performed two to four weeks after the completion of the third cycle; patients also received two additional cycles of chemotherapy after the operation. Patients randomly assigned to the immediate-surgery group underwent the same surgical procedure. The main end point was overall survival. RESULTS: Of the 440 eligible patients with adequate data , 213 were assigned to receive preoperative chemotherapy and 227 to undergo immediate surgery. After a median possible study time of 55.4 months, there were no significant differences between the two groups in median survival: 14.9 months for the patients who received preoperative chemotherapy and 16.1 months for those who underwent immediate surgery (P=0.53). At one year, the survival rate was 59 percent for those who received chemotherapy and 60 percent for those who had surgery alone; at two years, survival was 35 percent and 37 percent, respectively. The toxic effects of chemotherapy were tolerable, and the addition of chemotherapy did not appear to increase the morbidity or mortality associated with surgery. There were no differences in survival between patients with squamous-cell carcinoma and those with adenocarcinoma. Weight loss was a significant predictor of poor outcome (P=0.03). With the addition of chemotherapy, there was no change in the rate of recurrence at locoregional or distant sites. CONCLUSIONS: Preoperative chemotherapy with a combination of cisplatin and fluorouracil did not improve overall survival among patients with epidermoid cancer or adenocarcinoma of the esophagus.

Adenocarcinoma↗
PubMed1991

Hepatic resection versus transplantation for hepatocellular carcinoma.

During the 10-year period (1980 to 1989), 76 patients with hepatocellular carcinoma (HCC) were treated by subtotal hepatic resection (HX) and 105 patients by orthotopic liver transplantation (TX) under cyclosporine-steroid therapy. Overall 1- to 5-year survival rates of the HX group were 71.1%, 55.0%, 47.2%, 37.2%, and 32.9%, respectively, and those of the TX group were 65.7%, 49.0%, 39.2%, 35.6%, and 35.6%, respectively. The survival rates after HX and after TX correlated well with pTNM stages and were similar in each stage between the two groups. However, when HCC was associated with cirrhosis of the liver, the survival rates after TX were significantly better than those after HX at each stage of pTNM classification. The tumor-recurrence rate was high both after HX (50%) and TX (43%), particularly in advanced stages of pTNM classification (60% or more). Twelve patients after HX and 13 patients after TX lived more than 5 years during this 10-year period. Fibrolamellar HCC and early stages of HCC were highly represented among the long-term survivors. Further improvement in survival rates depends on nonsurgical anti-cancer therapy before and/or after surgical removal of HCC.

Adolescent↗
PubMed1991

Preneoplastic and neoplastic lesions in the pancreas of rats fed choline-devoid or choline-supplemented diets.

Groups of male Fischer 344 rats were chronically fed semipurified choline-devoid or choline-supplemented diets, high in fat (15%), and containing or not containing 0.06% phenobarbital. Atypical acinar cell nodules were observed in the pancreas of the rats, irrespective of the diet fed, with incidences varying from 38% to 100% in the various groups. No consistent differential effects of the dietary treatments on the incidence and growth of the nodules were evident, even though the diameter of the nodules tended to be greater in some of the groups fed the basal choline-devoid diet. The vast majority of the nodules were of the acidophilic type. More advanced pancreatic acinar cell lesions were observed in a few of the rats. Since the rats were not exposed to a chemical carcinogen(s), development of the nodules and of the more advanced lesions, even in rats fed the control diets, was most likely due to evolution of endogenous (spontaneous) initiated pancreatic cells, promoted primarily by the feeding of semipurified diets with a high fat content.

Animals↗
PubMed1990

Transplantation of the small intestine: the pathologist's perspective.

Small-bowel transplantation is now ready for clinical trials. The surgical techniques and methods for immunosuppression and monitoring bowel status have been developed in animal models over the past 30 years. Several attempts at small-bowel transplantation in humans have already been reported. In the course of future trials, pathologists will be involved in the monitoring of the posttransplant course by mucosal biopsies and functional studies, including maltose and xylose absorption tests. The morphology of rejection has been studied in canine and rat models. Activated lymphocytes and plasma cells infiltrate the lamina propria and invade crypt epithelium, causing "cryptitis." Villous blunting ensues, resulting eventually in necrosis. Graft survival without immunosuppression is about 10 days. Under Cyclosporine immunosuppression, a lymphoplasmacytic infiltrate has been noted around nerves and vessels in the submucosa. The overlying mucosa may be relatively normal. End-stage bowel is characterized by a contracted, scarred mass. Due to the large amount of lymphoid tissue in the allograft, graft-versus-host disease is a significant problem in small-bowel transplantation.

Graft Rejection↗
PubMed1989

Epithelioid hemangioendothelioma of liver. Clinicopathological correlation of 10 cases treated by orthotopic liver transplantation.

We present a review of the clinicopathologic features of a series of 10 patients with hepatic epithelioid hemangioendothelioma treated by orthotopic liver transplantation. This tumor has an unpredictable prognosis. Morphological features predictive of biological behavior were not identified in these patients. It appears that metastatic spread at the time of surgery is not a significant contraindication to surgery and has no correlation with survival. Nine patients are alive (5-134 months), five disease free and four with tumor. The etiology of this tumor is unknown. However, there is an association of oral contraceptive use with this tumor in four (66%) of the six female patients in this series and in 37% of such reported cases.

Adult↗
PubMed1989

Liver transplant rejection: value of the resistive index in Doppler US of hepatic arteries.

The authors prospectively evaluated the accuracy of the resistive index (RI) in Doppler ultrasound (US) for the detection of the increased vascular resistance that theoretically occurs with acute liver transplant rejection. RIs were calculated for the proximal hepatic artery and a more distal hepatic artery branch in 67 liver transplant recipients. Biopsies were performed within 24 hours of transplantation, with no intervening therapy. Examination of biopsy specimens by a single pathologist revealed findings of no, minimal, or moderate to severe rejection. RIs in hepatic arteries showed no significant differences among the three pathologic groups. No correlation was found between the RI and improved or worsened rejection in 11 patients who underwent biopsy and US more than once. RIs in hepatic arteries are of no value in the prediction of liver transplant rejection.

Acute Disease↗
PubMed1989

Immunomagnetic T-lymphocyte depletion (ITLD) of rat bone marrow using OX-19 monoclonal antibody.

Graft versus host disease (GVHD) may be abrogated and host survival prolonged by in vitro depletion of T lymphocytes from bone marrow (BM) prior to allotransplantation. Using a mouse anti-rat pan T-lymphocyte monoclonal antibody (OX19) bound to monosized, magnetic, polymer beads, T lymphocytes were removed in vitro from normal bone marrow. The removal of the T lymphocytes was confirmed by flow cytometry. Injection of the T-lymphocyte-depleted bone marrow into fully allogeneic rats prevents the induction of GVHD and prolongs host survival.

Animals↗
PubMed1988

Fibrolamellar carcinoma of the liver: an immunohistochemical study of nineteen cases and a review of the literature.

Hepatocellular carcinoma (HCC) is a rapidly fatal neoplasm of high worldwide prevalence. Fibromellar carcinoma (FLC), a variant of HCC, lacks the dismal prognosis of "ordinary" HCC (O-HCC) and is characterized by a diagnostic histologic appearance. The current study analyzes the clinical characteristics, immunohistochemistry, and treatment of nineteen cases of FLC. These data, together with a detailed review of the literature, further characterize this unique variant. FLC affects younger patients and lacks the male predominance of O-HCC. Also, FLC lacks specific association with cirrhosis, hepatitis B virus infection, use of oral contraceptives, and alcohol abuse, all of which are implicated in other hepatic tumors. This, along with differences in serum tumor marker prevalence (AFP, B12 binding protein) suggests that its pathogenesis differs from that of O-HCC. Despite these differences, FLC shares a common differentiation with O-HCC. The increased amounts in FLC of stainable alpha-1-antitrypsin, fibrinogen, and C-reactive protein, all of which are acute phase reactants and normal hepatocyte products, implies better differentiation of FLC cells. Finally, the better prognosis of FLC is supported by this study, since only two of the 19 patients died because of tumor. This contrasts with the reported survival of patients with O-HCC, usually measured in weeks. Hepatic transplantation may hold promise for future patients with "surgically unresectable" FLC as procedure-related complications are overcome.

Adult↗
PubMed1988

Acute allograft rejection in liver transplant recipients: lack of correlation with loss of hepatic artery diastolic flow.

Eighty hepatic artery Doppler ultrasound (US) examinations performed in 49 patients after liver transplantation were retrospectively analyzed to determine if loss of diastolic flow correlated with pathologic evidence of acute allograft rejection. All 80 Doppler examinations were performed within 7 days of hepatic needle biopsy. Forty-three Doppler waveforms from 27 patients showed normal diastolic flow. Seventeen Doppler studies in 17 patients showed complete absence of diastolic flow. Review of biopsy results for each group showed no significant difference in the proportion of acute allograft rejection present (42% for the normal group and 46% for the group lacking diastolic flow). The data from 53 US and biopsy examinations performed 2 days apart in 37 patients confirmed the lack of correlation between absent hepatic artery diastolic blood flow and rejection. The authors conclude that the loss of hepatic artery diastolic flow has no apparent clinical application for the diagnosis of acute hepatic allograft rejection.

Adult↗
PubMed1988

The role of the pathology department in a liver transplant program.

This article gives an overview of the role of the anatomic pathologist in a liver transplant program. The effect of such a program on the workload in each of the pathology subdisciplines is discussed. Differential diagnoses where the anatomic pathologist is of particular assistance, as well as diagnosis in which histopathology may be of little help, are described. Methods of tissue handling for optimal utilization of pathology services are outlined.

Humans↗
PubMed1986

Barrett's mucosa with multiple carcinomas of the esophagus and oral cavity.

A 62-year-old man with carcinoma of the tongue had two separate asymptomatic carcinomas of the esophagus, one squamous and the other adenocarcinoma arising from Barrett's mucosa. We review the multicentric origin and synchronous occurrence of tumors in the oropharyngoesophageal area with and without Barrett's mucosa to emphasize the importance of complete evaluation of the esophagus in patients with oropharyngeal malignancy.

Adenocarcinoma↗
PubMed1986

Recurrent hepatitis B in liver allograft recipients. Differentiation between viral hepatitis B and rejection.

The histologic findings in the original liver obtained from 9 liver allograft patients with active B virus hepatitis were compared with 28 posttransplant pathology specimens. All specimens were studied with the use of light and immunohistochemical microscopy in conjunction with pertinent clinical data. Eight of the 9 patients had chronic active hepatitis B (HB) with cirrhosis, prior to transplant, one of which had coexistent hepatocellular carcinoma. The ninth patient had fulminant hepatic necrosis secondary to acute HB prior to transplantation. In all of the patients with chronic HB prior to transplantation who survived more than 2 months after transplantation recurrent infection of the graft developed despite perioperative HB immunoglobulin therapy. The patient with acute fulminant hepatitis B pretransplant has done well postoperatively and has evidence of HB virus immunity (positive anti-HBs) 15 months after transplantation. Examination of tissue specimens obtained during episodes of allograft dysfunction in these 9 patients indicate that pathologic alterations of active HB infection of the allograft are associated with a preferential lobular insult, whereas those occurring in rejection preferentially involve portal tract structures. Serologic data combined with biopsy histopathologic data are essential in distinguishing between the two quite different events.

Diagnosis, Differential↗
PubMed1985

Focal lymphoid hyperplasia (pseudolymphoma) of the esophagus.

Focal lymphoid hyperplasia is an uncommon but ubiquitous lesion. It occurs most commonly in the gastrointestinal tract in association with chronic peptic ulcer disease of the stomach. We describe the hitherto unrecognized association of lymphoid hyperplasia in the esophagus with chronic stenosing ulcerating esophagitis and Barrett's mucosa. This association is considered to be analogous to the more prevalent coexistence of lymphoid hyperplasia and chronic peptic ulcer disease in the stomach.

Aged↗