Search PubMed⌕ Search

Biomedical subjects

J Boniver

Publications and source records attributed to J Boniver.

225 records · Page 13Linked to original sources
PubMedDate not supplied

[Molecular characterization of Epstein-Barr virus associated with classical Hodgkin's lymphoma in Tunisia: prevalence of the LMP1 oncogene deletions and A and B viruses strains].

Epstein-Barr virus (EBV) is detected in Hodgkin's lymphoma (HL) at variable frequencies, depending on various factors including the geographic location. The prevalence of EBV is high among HL diagnosed in the region of the center of Tunisia. The aim of the current work was to define the genotypic features of EBV in a series of EBV-positive HL in this area, in comparison to those of EBV found in association with benign lymphoadenopathies. A 30 bp and a 69 bp deletion within the LMP1 gene were detected in 41% and 11% of HL cases, respectively. In reactive lymph nodes, the 30 bp deletion was found in 43% of the cases. Type A EBV was detected in 84% of HL cases and in 96% of reactive lymphoadenopathies, and type B EBV was detected in others. No significant association was found between histological type of HL, age of the patients, or stage at diagnosis, and the molecular configuration of LMP1. However, LMP1 deletions were found more frequently among male patients. The significance of these results is discussed.

Adolescent↗
PubMedDate not supplied

Cellular aspects of the pathogenesis of radiation--induced thymic lymphomas in C57 BL mice (review).

Radiation-induced thymic lymphomas in C57Bl/Ka mice are interesting models for studying the successive steps of carcinogenesis. Irradiation initiates "preleukemic" cells, which are promoted to become neoplastic. Studies in mice in which lymphoma development is inhibited by a bone marrow transplantation after irradiation suggest that radiation--induced alterations to the T cell lineage, and particularly to thymic microenvironment, are critical for the promotion of preleukemic cells. It is proposed that the lack of physiological differentiation signals within the thymus, as a result of irradiation, allows these cells to escape the normal controls of thymocyte production and pushes them towards neoplastic transformation. A disturbance in the production of cytokines may be involved, since exogenous cytokines, such as Interferon gamma or Tumor Necrosis Factor a, can inhibit radiation-induced lymphomagenesis, reproducing the effects of bone marrow transplantation. The model is thus suitable for studying the mechanisms of carcinogenesis and designing biological manipulation devoted to cancer prevention in individuals who have been exposed to oncogenic agents.

Animals↗
PubMedDate not supplied

Fundic argyrophil cell hyperplasia in atrophic gastritis: a search for a sensitive diagnostic method.

Hypergastrinemia induces argyrophil cell hyperplasia in oxyntic mucosa (FACH) in patients with non-antral atrophic gastritis, with or without pernicious anemia. This proliferation favours the development of carcinoid tumours. In order to determine the most usual appropriate method to document FACH, we have studied 29 consecutive fundic biopsies from 26 patients with fundic chronic gastritis. The study encompassed gastrinemia levels, standard histology permitting the classification of chronic gastritis, demonstration of FACH by Grimelius stain, immunohistochemical studies using NSE, chromogranin A and by electron microscopy. The FACH was classified for each stain as slight, moderate or severe. The study displayed a relationship between the grade of gastritis and the density of argyrophil endocrine cells in oxyntic mucosa assessed by Grimelius stain (p < 0.0001) and chromogranin A (P < 0.01). There was also a relationship between the serum gastrin level and the density of argyrophil endocrine cells detected by these two stains (p < 0.001). A highly significant correlation was observed between Grimelius stain and chromogranin A (p < 0.0001). On the other hand, no significant correlation was noted with either NSE or electron microscopy. We conclude that Grimelius stain and immunohistochemical studies against chromogranin A were the best methods for the demonstration of FACH in atrophic gastritis. One of these two techniques is sufficient in current practice for defining the patients at risk for subsequent surveillance.

Anemia, Pernicious↗
PubMedDate not supplied

Fatal massive liver steatosis--a clinicopathological case report.

Hepatic fatty change is a common lesion. Two forms are recognized: micro- and macrovesicular steatosis, the former being much less frequent and more serious than the latter. The case of an alcoholic woman under anticonvulsivant therapy and with medications for a syndrome of inappropriate secretion of antidiuretic hormone (SIADH) who presented with rapidly progressive cholestasis and hepatocellular failure is reported. Massive macro- and micro-vesicular hepatic steatosis was diagnosed at autopsy. The authors review the clinico-pathological features associated with this condition, and causal factors possibly implicated in this case are discussed in regard with currently considered pathophysiological mechanisms.

Anti-Bacterial Agents↗
PubMedDate not supplied

p53, Bax and Bcl-2 in vivo expression in the murine thymus after apoptogenic treatments.

BACKGROUND: Neoplasia can results from a lack of cell elimination by apoptosis. In order to determine if mechanisms controlling apoptosis are disturbed during neoplastic transformation in a model of murine radio-induced thymic lymphomas, we have assessed the kinetics of p53, Bax and Bcl-2 in situ expression after induction of thymic apoptosis by irradiation or glucocorticoids at first in normal mice. MATERIALS AND METHODS: TUNEL method was used for in situ detection of apoptosis and protein expression was determined by indirect immunohistochemistry. RESULTS: After hydrocortisone injection, levels of p53 and Bax, but not Bcl-2, expression were raised. A whole body sublethal irradiation led to an increase of p53 and Bcl-2, but not Bax, expression. CONCLUSIONS: This is the first in vivo report of in situ protein expression in the thymus after apoptogenic treatments of mice. The results suggest that Bax could be involved in glucocorticoid-mediated apoptosis. The increased levels of Bcl-2 expression are discussed.

Animals↗
PubMedDate not supplied

Apoptosis during the development of radiogenic thymic lymphomas: effects of treatments inhibiting lymphoma development.

INTRODUCTION: Whole body fractionated irradiation induces thymic lymphomas in C57BL/Ka mice after a latent period during which preleukemic cells progressively transform into leukemic cells within an abnormal thymic microenvironment. A bone marrow graft or repeated cytokine injections prevent lymphoma development. We think that these treatments restore altered mechanisms controlling apoptosis. MATERIALS AND METHODS: Apoptosis was analyzed by flow cytometry in thymocytes from different groups of mice (control, preleukemic, prevented mice). RESULTS: The apoptotic rates did not change in freshly isolated thymocytes from different experimental groups. However, after culture, the level of apoptosis increased in preleukemic thymuses; and returned to normal value in cultured thymocytes from irradiated mice after lymphoma preventing treatments. Furthermore, thymic microenvironmental factors can control thymocyte apoptosis. CONCLUSION: We propose that after leukemogenic irradiation, there is an increase of cells with an activated suicide program, but that alterations of thymic environmental factors rescue them from apoptosis, allowing their further neoplastic transformation.

Animals↗