Biomedical subjects

P Peysson

Publications and source records attributed to P Peysson.

3 recordsLinked to original sources

PubMed2001

[Mucosal endoscopic resections].

Endoscopic mucosectomy is a newly developed endoscopic technique allowing the resection of large fragments of digestive mucosa. The main indications of this technique are the staging and/or the treatment of superficial lesions of esophagus, stomach and colon. Resections by endoscopic mucosectomy raise specific problems of macroscopic technique and histological analysis. For correct inclusion, fragments must be pinned under a rigid support by the endoscopist. Their lateral margins must be sampled independently. The fragment must be included in totality. The histological report must indicate the depth of the resection and its quality, particularly the status of lateral and deep margins. The main difficulties of the histological analysis are due to the frequent occurrence of coagulation artefacts, which may hamper a correct interpretation of the lesions, particularly along the lateral margins. The appropriate management of endoscopic mucosal resections requires a good collaboration between endoscopists and pathologists.

Colonic Neoplasms↗

PubMed1994

Localization of the expression of type I, II and III collagen genes in human normal and hypochondrogenesis cartilage canals.

The expression of type I, II and III collagens genes was examined in human normal and hypochondrogenesis cartilage canals employing electrophoretic analysis, immunohistochemistry and in situ hybridization techniques. In normal cartilage, collagens type I and III were present in perichondrium, in the connective tissue surrounding the vessels of cartilage canals and in the dense fibrous tissue. However, types I and III procollagen mRNAs were detected only in fibroblasts of the perichondrium and of the canals, but not in the polymorphic cells. Type II collagen was present in the cartilage matrix and in the dense fibrous tissue, in good accordance with the localization of type II procollagen mRNAs detected in the chondrocytes and in the polymorphic cells. These data suggest that there are no transitional cells expressing type I, II and III collagen genes and that polymorphic cells are of chondrocytic origin. In the case of hypochondrogenesis, type II collagen was less abundant than in normal cartilage, whereas the corresponding mRNA level was equivalent. That suggests that a postranscriptional regulation of this protein is involved in the decrease of type II collagen production. Type I collagen, unexpectedly detected in the cartilage matrix, was synthesized by chondrocytes and polymorphic cells, suggesting a replacement of type II by type I collagen. The canal hypertrophy observed in this pathological case could thus be due to a modification in the regulation of the growth of cartilage canals caused by a defective cartilage matrix.

Cartilage↗

PubMed1993

[Alexander's disease in adults and diffuse cerebral gliomatosis in 2 members of the same family].

A 31-year old woman died after 10 years of progressive dysautonomia and cerebellar and pyramidal symptoms. CT scan showed pontine, bulbar and cerebellar atrophy. Post-mortem examination revealed Rosenthal's fibers widespread throughout the CNS, but especially in the subependymal and perivascular regions. White matter cavitations involving peri-ventricular regions, hilum of dentate nuclei and pons were observed, leading to a diagnosis of adult form of Alexander's disease. At the age of 5, the patient had been operated upon for a chiasmatic tumor. Microscopic examination revealed a pilocytic astrocytoma without Rosenthal's fibers. No complementary radiotherapy had been done. Her mother has been operated upon in 1972, for a high-grade glioma and is still alive 20 years later. This suggests diffuse cerebral gliomatosis. This family history may suggest a relation between these different diseases. They might be the result of a transmissible astrocytic abnormality with varying expression.

Adult↗