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Biomedical subjects

G Chomette

Publications and source records attributed to G Chomette.

At least 109 records · Page 6Linked to original sources
PubMed1987

[Histiocytosis X of the jaws. II. Structural, histo-enzymologic and immunohistochemical study].

A series of cases of histiocytosis X was studied by immunohistochemistry (20 cases), histoenzymology (5 cases) and electron microscopy (15 cases). The immunohistochemical methods showed in the majority of cells (histiocytes similar to Langerhans' cells), OKT6, HLA-DR ans S-100 protein antigens. Besides, Leu 4 antigen was also present on the surface of some cells. The histoenzymological analysis found acid phosphatase and specific esterases activities with a different repartition in histiocytes compared to macrophages. By electron microscopy, we detected the typical Birbeck granules. The signification of these granules and also the pathogenesis of the disease were discussed.

Fluorescent Antibody Technique↗
PubMed1987

[Pleomorphic adenoma. Diagnostic difficulties. Value of ultrastructural and immunohistochemical studies. Apropos of 2 cases].

2 cases of pleomorphic adenoma with unusual histological feature are related. In the 1st case, the tumor was mistaken for a schwannoma. The electron microscopic study only permitted the diagnosis; in the 2nd case, the tumor, obviously malignant, was firstly diagnosed as synovial sarcoma; in this case also, ultrastructural study permitted to recognize a malignant mixed tumor with an unusual "sarcomatous" change of its myoepithelial component.

Adenoma, Pleomorphic↗
PubMed1987

[Mesenchymal chondrosarcoma. Anatomico-clinical, immunohistochemical and ultrastructural study. Apropos of a case].

One case of mesenchymal chondrosarcoma of the mandible is reported in a 18 years-old man. The patient noted swelling and pain and roentgenography showed an osteolytic lesion of the right mandible. Histologically, the feature was obvious with chondroid sheets of round ovoid or elongated cells. Immunohistochemically, numerous cells had positive S-100 protein and vimentin. The electron microscopy showed numerous undifferentiated cells and also fibroblastic and cartilaginous cells. The prognosis of this tumor, usually bad, cannot be yet appreciated in this case (follow-up of only 3 months). The histogenesis of this peculiar variety of chondrosarcoma is discussed.

Adolescent↗
PubMed1987

[Cardiac transplantation. Selection of patients and long-term results].

Performed for the first time in the world, in December 1967, by Barnard in Capetown, and for the first time in Europe by our team in April 1968, cardiac transplantation has now 20 years of clinical applications. A best selection of the recipients, a more precise selection of donors, refinements in surgical technique, a better and earlier diagnosis of post-operative complications, more effective therapeutic means especially cyclosporin, have brought us, from 1981, such major improvements that many teams were prompted to resume the procedure. In our experience of more than 400 transplants at La Pitié Hospital, a five-year follow-up shows that 70 p. cent of the patients are alive, having resumed a normal familial, social, professional and often sporting life. Much progress remains to be achieved, but this procedure now seems to be quite common if not routine, only limited by the insufficient number of donors.

Adult↗
PubMed1987

[Effect of the soft laser on gingival connective tissue. I--Effect on fibroblasts. Histoenzymology and electron microscopy study].

The effect of soft-laser upon human gingival fibroblasts was studied after an initial biopsy followed by irradiation and numerous biopsies performed 5 mn, 15 mn, 1 hour and 24 hours after irradiation. In addition, control biopsies were performed in the same way on a non-irradiated gingival area. One hour after irradiation and up to 24 hours later, the enzymatic activities of the fibroblasts were obvious: oxidative enzymes, leucine aminopeptidase, and considerable Brachet's test highly positive (RNA). By transmission electron microscopy were changes were found in these fibroblasts. They were more numerous and their cytoplasmic organelles were increased (mitochondria, rough endoplasmic reticulum). An abundant granular material as well as collagen fibrils were accumulated along their cytoplasmic membrane. On the whole, from the 1st hour on following irradiation by soft-laser a stimulation of metabolic activity of the fibroblasts (oxidative activities, proteic synthesis) was observed with increased production of collagen.

Connective Tissue Cells↗
PubMed1987

[Effect of the soft laser on gingival connective tissue. II--Effect on wound healing. Optical microscopy, histoenzymology and electron microscopy studies].

The effect of soft-laser upon cicatrization of the gum was studied in 14 patients. After the initial biopsy, control biopsies were performed on the same patients in non-irradiated gums. In the absence of inflammation, cicatrization took place in a similar manner in the irradiated and control tissues. After an early vascular growth, connective cylinders occurred, accompanied by an increase of enzymatic activity) (oxidative enzymes, leucine aminopeptidase, alkaline phosphatase). Then, the scar was formed of longitudinal bundles. The laser induced an earlier cicatrization (14th day) than in the controls (21st day). The presence of inflammation in the gum delayed cicatrization and often promoted cheloid scars with abnormal anastomosing connective bundles. In this case also, irradiation by soft-laser was followed by a quicker and better cicatrization.

Fibroblasts↗
PubMed1987

[Fibrous dysplasia and ossifying fibroma. Morphologic criteria].

Among a series of 42 ossifying fibromas and 32 fibrous dysplasias, 5 cases were studied by histoenzymological and electron microscopic methods. The histological study in 2/3 of cases is sufficient for the diagnosis between the two diseases: trabecular bone in a connective tissue with regular collagen fibres in the ossifying fibroma; nodular indented bony areas with irregular collagen frame in fibrous dysplasia. By histoenzymology, the diagnosis between the two affections is not easy: same activity of ATPases and alkaline phosphatases in fibroblasts and osteoblasts. By electron microscopy, the morphology of the two lesions is different: in ossifying fibroma, numerous well-differentiated osteoblasts and large areas of ossification are seen; in fibrous dysplasia, undifferentiated cells are numerous and the collagen frame is irregularly mineralized. This method is also useful for the histogenetic understanding of these two osteopathies.

Collagen↗
PubMed1987

[Malignant xanthogranuloma of the cervicofacial region. Optical and ultrastructural morphology. Apropos of 4 cases].

The 4 cases of malignant xanthogranuloma reported here are peculiar because of their unusual localization in the cervico-facial area and of their good outcome (3 patients are alive without recurrence more than 6 years after chemotherapy and radiotherapy). Besides the histological study, the 4 cases were examined by immunohistochemical methods : vimentin was positive in 20 to 40% of cells and lysozyme in 5 to 15% of cells. In addition, one case was studied by electron microscope which showed the polymorphism of tumoral cells.

Adult↗
PubMed1987

[Cells in the normal human periodontal ligament. An ultrastructural, histo-enzymological and immunocytochemical study on in vitro cultures].

Four cellular cultures from explants of human periodontal ligament were studied. In these cultures, cells were fusiform or stellate with a high percentage (5 to 10%) of round mitotic cells. The scanning electron microscope confirmed the simultaneous presence of flat cells in interphase and cells in prophase with microvilli and long filipodes and of round mitotic cells with microvilli and blebs. Histoenzymology disclosed in these cells high activities in oxidative enzymes and leucine aminopeptidase. Furthermore some cells showed an alkaline phosphatase activity. Immunocytochemistry detected in most of these cells intermediate vimentin filaments and the presence of type I and III collagen irregularly distributed among these cells. In transmission electron microscopy the elongated cells presented a clear nucleus, numerous endocytosic vesicles, ribosomes and longitudinal filaments. Variations were noted, especially in the quantity and quality of cell secretions, the fibroblasts secreting either the two type I and III collagen or only type I. The rare cells assuming alkaline phosphatase activity were atypical in possibly being provided with osteogenic potential.

Adult↗
PubMed1987

[Histiocytosis X of the jaw. I. Anatomico-clinical study apropos of 61 cases].

61 cases of histiocytosis X of jaws were reported here. They occurred more often in man (72% of men) than in woman, with an average age of 27 years. The mandible was affected more frequently than the maxilla. Clinically, dental expulsion, gingival swelling, fractures or pain were the usual symptoms. Roentgenographic examination showed either central or peripheral (alveolar bone) osteolytic areas. The histologic diagnosis was easy when eosinophilic polymorphous leukocytes or histiocytes were preponderant. In the other cases, immunohistochemistry (positivity of S-100 protein) and electron microscopy (presence of Birbeck granules about paraffin embedded specimens) were of a great usefulness. The prognosis of the disease was mainly related to the diffusion of lesions to other skeletal portions or extraskeletal localizations (37% of our cases). It has been improved by combination of chemotherapy to surgery (despite of frequent recurrences), 40 upon 45 patients are well after a follow-up of 2 to 10 years after the last localization.

Adolescent↗