Showing papers by "Frédéric Charlotte published in 1994"

Immunohistochemical detection of bcl-2 protein in normal and pathological human liver.

Abstract: The bcl-2 protein, which prolongs cell survival by blocking apoptosis, is expressed by progenitor cells in several self-renewing tissues and by tumoral cells in some extrahepatic neoplasms. Because the liver is a slow self-renewing tissue, an immunohistochemical study of the cellular distribution of the bcl-2 protein was performed in normal liver (12 cases), nontumoral hepatic lesions (33 cases), and benign or malignant liver tumors (46 cases). In normal liver, bcl-2 was expressed by bile ductules and small bile duct epithelium, but not by hepatocytes or large bile duct epithelium. In cirrhosis and focal nodular hyperplasia, epithelial cells of the ductular proliferation were bcl-2-positive. Eight of 11 cholangiocarcinomas stained positively for bcl-2, whereas all 15 hepatocellular carcinomas were bcl-2-negative. bcl-2 was also expressed in 6 of 14 metastatic adenocarcinomas. These findings suggest that the ductular cells and small bile duct epithelial cells might have a prolonged survival and might be hepatic progenitor cells. In addition, the bcl-2 protein appears to be a marker of cholangiocarcinoma but not of hepatocellular carcinoma and could help in distinguishing between these two primary liver tumors.

Nonepidermotropic cutaneous lymphomas : a histopathological and immunohistological study of 52 cases

Abstract: We report the detailed histological and immunohistological findings in 52 cases of nonepidermotropic cutaneous lymphoma, as revealed by cutaneous lesions. The patients presented mainly with cutaneous nodules and, more rarely, with infiltrated plaques, annular erythema, or erythroderma. The staging procedure following the diagnosis revealed lymph node and/or bone marrow involvement in half of the cases. Nearly 60% of the nonepidermotropic cutaneous lymphomas were of the large-cell type. The reticular dermis was involved in all of the cases, and the papillary dermis was involved in only 11 of them. Nonepidermotropic cutaneous lymphomas were of the B-cell, T-cell, and non-B-, non-T-cell type in 38, 13, and 1 case(s), respectively. A monotypic immunoglobulin light chain expression was detected in 33 of 35 tested cases of the B-cell lymphomas, and a loss of one or several pan-T-cell antigens was observed in all of the cases of the T-cell lymphomas. In seven cases (13%), the diagnosis of malignancy was based only on these immunohistological criteria. This study shows that nonepidermotropic cutaneous lymphomas are B-cell lymphomas in 75% of the cases, most often of the large-cell type. It also emphasizes the value of immunohistochemistry to firmly establish malignancy when routine light microscopical findings are questionable.

[Histopathologic lesions of the accessory salivary glands in Gougerot-Sjögren syndrome: re-evaluation of the diagnostic criteria of Chisholm and Mason and of Chometter et al].

Abstract: In a retrospective study, we used a series of 29 patients with Sjogren's Syndrome diagnosed according to the new European criteria (Cl. Vitali, S. Bombardieri, H. M. Moutsopoulos et al.) (8). (Arthritis Rheum 1993; 36:340-7). A labial biopsy technique allowed to classify these patients into the anatomical "scores" formerly related by Chisholm and Mason and Chomette et al. Referring to these criteria, only 45% of patients presented a characteristic histopathological pattern. If another complementary criterium, i.e. ductal tropism of lymphoid infiltrates, was added, that percentage remained low (50% only). Thus, these results would suggest the following considerations: the classical histopathological criteria do not seem sufficiently specific; other histological criteria such as ductal lesions previously noted by Leroy et al. must in addition be looked for; thus it would seem to be of considerable value to use in the future complementary quantitative studies by means of morphometric methods.

Value of a powerful initial immunosuppression after liver transplantation. Prospective study of 60 cases

Abstract: With usual immunosuppression, the incidence of acute rejection after liver transplantation is higher than 60% in most series. The aim of this prospective study was to assess the value of a powerful initial immunosuppression on acute rejection, mortality and morbidity. REGIMEN. Group 1: patients with normal postoperative renal function (serum creatinaemia or = 150 mumol/L), anti-thymocyte globulins were used for 10 days; cyclosporine was introduced after recovery of renal failure at usual doses. In addition, all patients received steroids and azathioprine according to usual regimens. RESULTS. From January 1989 to June 1992, 60 cases were studied in 59 patients: 45 (75%) entered group 1 and 15 (25%) entered group 2. In group 1, there were 11 acute rejection episodes (24%) and one postoperative death at three months (2.3%). In group 2, two early deaths (within 5 days) were excluded from the study of rejection. Among the 13 remaining cases, there were three episodes of acute rejection (23%) and one hospital death at three months. Overall, there were 14 episodes of acute rejection (24%), 12 of which were steroid-responsive (86%), no chronic rejection, a usual rate of infections (57%), one retransplantation (1.7%) and a hospital mortality of 6.8% (4 of 59 cases). One year survival was 78%, with 5 of 7 late deaths due to recurrent cancer. CONCLUSIONS. Our results suggest that, after liver transplantation, a) high initial cyclosporine dose in patients with normal postoperative renal function is associated with reduced incidence and severity of acute rejection without increased mortality and morbidity, b) antithymocyte globulins are an efficient alternative to cyclosporine in patients with postoperative acute renal failure and saves OKT3 for the treatment of steroid-resistant rejection.