PubMed HealthSearch

Biomedical subjects

M Perrier

Publications and source records attributed to M Perrier.

At least 19 recordsLinked to original sources

Dento-maxillofacial sequelae in a child treated for a rhabdomyosarcoma in the head and neck. A case report.

This case report describes severe dento-maxillofacial defects after chemoradiation therapy in a child aged 9 years 6 months with a parameningeal rhabdomyosarcoma. A clinical and radiologic (apical dental radiographs, orthopantograph, lateral skull roentgenogram) dental follow-up over 4 years showed such dental abnormalities as root blunting, mild to severe root shortening, premature closure of the root apices, and severe radiation caries. Craniofacial morphology evaluated by cephalometric analysis and dental models showed deficiency with mandibular and maxillary hypoplasia.

Child

Intracellular pH in arbuscular mycorrhizal fungi. A symbiotic physiological marker

A method was developed to perform real-time analysis of cytosolic pH of arbuscular mycorrhizal fungi in culture using dye and ratiometric measurements (490/450 nm excitations). The study was mainly performed using photometric analysis, although some data were confirmed using image analysis. The use of nigericin allowed an in vivo calibration. Experimental parameters such as loading time and concentration of the dye were determined so that pH measurements could be made for a steady-state period on viable cells. A characteristic pH profile was observed along hyphae. For Gigaspora margarita, the pH of the tip (0-2 &mgr;m) was typically 6.7, increased sharply to 7.0 behind this region (9.5 &mgr;m), and decreased over the next 250 &mgr;m to a constant value of 6.6. A similar pattern was obtained for Glomus intraradices. The pH profile of G. margarita germ tubes was higher when cultured in the presence of carrot (Daucus carota) hairy roots (nonmycorrhizal). Similarly, extraradical hyphae of G. intraradices had a higher apical pH than the germ tubes. The use of a paper layer to prevent the mycorrhizal roots from being in direct contact with the medium selected hyphae with an even higher cytosolic pH. Results suggest that this method could be useful as a bioassay for studying signal perception and/or H+ cotransport of nutrients by arbuscular mycorrhizal hyphae.

Journal Article

[Osteoradionecrosis. A review of the literature].

Osteoradionecrosis is a severe complication of radiotherapy characterized by the following sequence: radiation, trauma, bone exposure. The radiation reduces the vascularization potential of the tissues which leads to a hypoxic state that jeopardizes cellular activity and collagen formation. The diagnosis of osteoradionecrosis relies on the clinical examination of chronically exposed bone. Although this type of lesion is not limited to the jaws, the ratio between mandible and maxilla is 24:1. The severity of the lesion is a function of the radiation dosage. The main etiological factors of osteoradionecrosis are related to dental and periodontal pathology as well as to tooth extraction performed after, during or shortly before radiotherapy. Edentulous patients are less exposed to osteoradionecrosis than dentulous patients. Local treatment and antibiotic therapy are initially performed in mild cases. Surgical measures with hemiresection or block resection are indicated depending on the severity of the lesion. Some authors regard hyperbaric oxygen treatment as an efficient therapeutic and preventive technique. Prevention is of major concern. It requires a careful evaluation of soft and hard tissues of the oral cavity as well as the organization of an intensive prophylaxis program. Patient compliance is a prerequisite. This article is a literature review on osteoradionecrosis with its symptoms, incidence, pathogenesis, treatment and prevention.

Combined Modality Therapy

[AIDS and dentistry].

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome