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Biomedical subjects

M C Rousselet

Publications and source records attributed to M C Rousselet.

At least 55 records · Page 3Linked to original sources
PubMed1992

Contribution of immunohistochemistry, electron microscopy, and cell culture to the characterization of nonfunctioning pituitary adenomas: a study of 40 cases.

We studied 40 endocrinologically inactive pituitary adenomas by immunohistochemistry, electron microscopy, and cell culture in order to determine the incidence of gonadotropic adenomas and to classify nonfunctioning adenomas. Immunohistochemical studies using a large panel of monoclonal and polyclonal antibodies identified the following nonfunctioning adenomas: 20 gonadotropic adenomas, four silent corticotropic adenomas, one plurihormonal adenoma, and 15 nonsecreting adenomas. Among nonsecreting adenomas, ultrastructural study of 13 cases identified seven null cell adenomas and six oncocytomas. Silent corticotropic adenomas were classified into subtypes I, II, and III according to Kovacs and Horvath. Most often, gonadotropic adenomas displayed a varying number of oncocytic cells, characteristic secretory granules, and a prominent Golgi apparatus. Postembedding immunoelectron microscopy was performed on eight gonadotropic or nonsecreting adenomas, but this technique did not provide any additional information. Six gonadotropic adenomas and 10 so-called nonsecreting adenomas were studied in primary cell cultures. The six gonadotropic adenomas and seven of the 10 nonsecreting adenomas released gonadotropins in the culture medium. The use of in vitro results as a supplementary diagnostic criterion allowed classification of the 40 nonfunctioning adenomas as follows: 27 gonadotropic adenomas, four silent corticotropic adenomas, one plurihormonal adenoma, and eight nonsecreting adenomas. These results demonstrate a high proportion of gonadotropic adenomas among nonfunctioning adenomas (67.5%) and the usefulness of several techniques in characterizing this type of pituitary adenoma.

Adenoma↗
PubMed1992

Splenic lymphoma with circulating villous lymphocytes. Report of a case with immunologic and ultrastructural studies.

A case of splenic lymphoma with circulating villous lymphocytes is reported. Short surface cellular expansions were observed on blood and marrow films and by transmission electron microscopy. The immunophenotype was that of mature B cells without CD5, CD10, CD11c, or CD25 expression or tartrate-resistant acid phosphatase. Despite a basophilic plasmacytoid-like cytoplasm, this case of splenic lymphoma with circulating villous lymphocytes differed from splenic immunocytoma in that immunofluorescence and ultrastructure suggested that the neoplastic cells did not possess high levels of intracytoplasmic immunoglobulin. Treatment of cytopenia was best achieved by splenectomy and the total follow-up thus far (30 months) seems to indicate a case of low-grade malignant lymphoma.

Aged↗
PubMed1992

Primary Epstein-Barr virus infection with clonal T-cell lymphoproliferation.

A case of fatal Epstein-Barr virus infection in a previously healthy girl who was first found to have severe infectious mononucleosis with spontaneous recovery is reported. Because an abnormal immune response to the virus persisted, the disease relapsed, manifesting in cutaneous and pulmonary lesions associated with hemophagocytic syndrome responsible for death. Pathologic findings were characterized by polymorphous atypical lymphoid infiltrate, prominent necrosis, and histiocytic hyperplasia. Lymphoid cells displayed CD8 phenotype and clonal T-cell receptor gene rearrangement. Viral genome was detected in lesions by Southern blot and located in nuclei of lymphoid cells by in situ hybridization. Pathologic findings suggested fatal infectious mononucleosis; however, phenotype and genotype favored a malignant diagnosis. Clonality was demonstrated to have arisen during primary infection. Virologic examination indicated that Epstein-Barr virus was a causative agent. Such a process belongs to the recently recognized spectrum of Epstein-Barr virus-related T-cell lymphoproliferative disorders that might overlap fatal infectious mononucleosis in patients who are especially vulnerable to the virus.

Adolescent↗
PubMed1992

[Nephrogenic nephroma].

Nephrogenic nephroma was individualized by A. Pagès in 1980 as a rare renal neoplasia that mainly occurs in adolescents and adults and presents a benign outcome. The tumor is composed of very small tubular, papillary, and glomeruloid structures. Immunohistochemistry and electron microscopy show that the tumor is a proliferation of primitive epithelial cells that mimic the embryonal nephron. This neoplastic entity has often been confused with a nephroblastoma, although it is a benign tumor that is cured by simple resection. Further studies are needed to define its exact incidence and its histogenesis.

Adolescent↗
PubMed1992

[Management of a focal hepatic mass: propositions of a workshop].

Focal hepatic masses are a common problem, due to the expansion of ultrasound. Individuals engaged in the four disciplines involved (hepatogastroenterology, digestive surgery, radiology and pathology) met to summarize the information available, to compare their experience and to make synthetic proposals. The method consisted of an expert report, discussion of the clinical cases, workshop discussion for each discipline around synthetic proposals, reporting of these proposals in full session and discussion. The results, i.e. the synthetic and consensual proposals concerned diagnosis, treatment and monitoring of focal hepatic masses are presented for each discipline.

Biopsy↗
PubMed1991

Presence of renin, angiotensinogen, angiotensin II in the lamb anterior pituitary gland: immunocytochemical study after cryoultramicrotomy.

The presence of renin, angiotensin I-converting enzyme and angiotensin II detected by immunocytochemistry in the adult male rat anterior pituitary has suggested the existence of a pituitary renin-angiotensin system. To establish another mammalian experimental model we have investigated the presence of renin, angiotensinogen, angiotensin I-converting enzyme, and angiotensin II II in five normal lamb anterior pituitaries by immunocytochemistry after cryoultramicrotomy. Renin, angiotensinogen and angiotensin II immunoreactivities were observed only in cytoplasmic granules of lactotrophs, and the three proteins were found co-localized with prolactin in the same granules by double immunolabelling. No immunoreactive angiotensin I-converting enzyme was observed. These results suggest an activation of renin in the cytoplasmic granules of lactotrophs leading to a local synthesis of angiotensin II. Thus, the lamb anterior pituitary may provide a good experimental model for investigating the possible autocrine action of a local renin-angiotensin system on prolactin release in the human pituitary.

Angiotensin II↗
PubMed1990

Stenotic intimal thickening of the external iliac artery in competition cyclists.

Twenty-three cases of an arterial disease that affects competition cyclists are reported. Patients complained of intermittent acute claudication appearing on one lower limb only at the time of a maximal strain while cycling. Doppler hemodynamic investigation on an ergometric bicycle revealed a collapse of the ankle systolic pressure. Arteriography showed a sinuous lengthening and moderate stenosis of the external iliac artery. Pathologic examination of the artery disclosed a stenotic intimal thickening due to moderately cellular loose connective tissue with a variable distribution of collagen and elastic fibers. The cells in the affected zone were readily labeled with anti-actin and anti-myosin antibodies, and electron microscopy revealed features of synthetic smooth muscle cells. The lesion observed differs from intimal fibrodysplasia and from artherosclerosis. Abnormal local hemodynamic conditions may lead to this type of lesion. Thus, stenotic intimal thickening of the external iliac artery appears to be a new arterial disease defined by clinical, arteriographic, and pathologic features.

Adult↗
PubMed1990

Immunocytochemical and biochemical evidence of renin in human lactotrophic cell cultures.

Primary cell cultures from human prolactin (PRL)-secreting adenomas were used to test the ability of human lactotrophs to synthesize renin in vitro. The renin content of the culture medium and of cellular extracts was measured by enzyme-linked immunosorbent assay. The level of PRL release in the culture medium and the amount of PRL in a cellular extract were determined by radioimmunoassay. Morphologic studies included indirect immunofluorescence, pre-embedding immunoelectron microscopy using a three-layer peroxidase-antiperoxidase method and postembedding immunoelectron microscopy using protein A-gold complexes. Renin was detected in cellular extracts and was found to be absent in the culture medium, whereas PRL was extracellularly secreted. PRL and renin immunoreactivity was observed in all the cultures studied by immunofluorescence. The subcellular localization of renin was found to be similar to that of PRL and was observed in the rough endoplasmic reticulum, the Golgi apparatus, and cytoplasmic secretory granules. The results suggest that, in vitro, renin may be synthesized and intracellularly metabolized in human adenomatous lactotrophic cells rather than secreted. Cell cultures may be a useful model to further the understanding of the role of a local renin-angiotensin system in PRL secretion.

Female↗
PubMed1989

Renin and cathepsin B in human pituitary lactotroph cells. An ultrastructural study.

Renin, prorenin and cathepsin B were localized in human lactotrophs using immunoelectron microscopic techniques. Renin and prorenin were found in numerous cytoplasmic granules. Cathepsin B, a lysosomal enzyme known to be able to activate prorenin into renin, was also present in cytoplasmic granules of lactotrophs. The co-localization of renin and prolactin in the same secretory granules was demonstrated by double immunolabelling. Renin and cathepsin B were co-localized in some granules by the same technique. These results suggest a local activation of renin in the secretory granules of lactotrophs and support the hypothesis of a possible autocrine action of the renin-angiotensin system on prolactin release.

Adenoma↗
PubMed1989

A case of temporal arteritis with intrahepatic arterial involvement.

We report a case of temporal arteritis associated with anicteric cholestasis. Serial sections of a transthoracic needle biopsy of the liver revealed giant-cell arteritis in medium-sized hepatic arteries and cholangitis in adjacent bile ducts. The literature reveals that similar pathologic features have only exceptionally been observed in liver biopsies. These lesions may account for liver function disturbances commonly seen in temporal arteritis or polymyalgia rheumatica.

Aged↗
PubMed1988

Idiopathic thrombocytopenic purpura in patients at risk for acquired immunodeficiency syndrome. Histopathologic study, immunohistochemistry, and ultrastructural study on six spleens.

Some cases of idiopathic thrombocytopenic purpura (ITP) may be related to the prodromal phase of the acquired immunodeficiency syndrome (AIDS). The morphologic features of six spleens removed in this context were studied. In the white pulp, lymphoid follicular hyperplasia was constant but hardly distinguishable from that of control ITP on routine light microscopic grounds. Moreover, its bland appearance contrasted with the major histopathologic changes usually described in lymph node biopsy specimens from patients with AIDS-related complex. Immunohistochemistry and electron microscopy demonstrated, respectively, an excess of cytotoxic-suppressor lymphocytes with a decreased CD4/CD8 ratio in the germinal centers and viral particles of the human immunodeficiency virus. The immunohistochemical and ultrastructural studies were more helpful than light microscopy in presenting histopathologic arguments in favor of the human immunodeficiency virus infection.

AIDS-Related Complex↗
PubMed1986

[Reproducibility and prognostic value of Gleason's and Gaeta's histological grades in prostatic carcinoma].

Two histopathologic grading systems for prostatic adenocarcinomas are reevaluated: the Gleason system and the Gaeta system. Two pathologists reviewed 234 specimens to assess reproducibility. Exact agreement is achieved in 88% with the Gaeta system, in 65% with the Gleason system. Nevertheless, agreement to within one score unit is achieved in 94% with the Gleason grading. One pathologist's autoreproducibility exceed 80% with either system. Actuarial survival curves and mortality index (deaths per patient-year of follow-up) provided evidence of their predictive value. Regardless of the clinical stage these two grading systems select groups of patients sharing a good, intermediate or bad prognosis but none can predict a given patient's accurate survival. The Gleason system would allow a better discrimination between poorly and highly aggressive tumors of intermediate grade.

Adenocarcinoma↗