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M Perrier

Publications and source records attributed to M Perrier.

At least 37 records · Page 2Linked to original sources
PubMed1994

[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↗
PubMed1992

[AIDS and dentistry].

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Surgery for carcinoma of the colon in people aged 75 years and older.

From January 1976 to June 1986, 154 patients (75 men and 79 women) who were 75 years of age or older were admitted for the surgical treatment of a colonic cancer. The mean age was 80.7 years. Patients were divided into two groups: 66 patients, between 75 and 80 years of age, were in Group I; 88 patients, 80 years of age and older, were in Group II. One hundred and forty-three patients (93%) were operated on and a resection was carried out in 125 patients (87%). The overall post-operative mortality rate was 12% (Group I: 5%; Group II: 17%; p less than 0.02). The actuarial survival rate of patients operated on was 32 +/- 8% at 3 years and 26 +/- 8% at 5 years (Group I: 37%; Group II: 17%). In both groups the survival rate was closely related to the extent of the disease according to Dukes classification. These results suggest that in the 75-80 year group age alone should no longer be considered a major risk factor for immediate surgical outcome. In patients aged 80 and older, the results are worse but it is not advanced age per se which influences mortality, rather the physiologic status of the patient.

Aged↗
PubMed1990

Liquid-to-Gas Mass Transfer in Anaerobic Processes: Inevitable Transfer Limitations of Methane and Hydrogen in the Biomethanation Process.

Liquid-to-gas mass transfer in anaerobic processes was investigated theoretically and experimentally. By using the classical definition of k(L)a, the global volumetric mass transfer coefficient, theoretical development of mass balances in such processes demonstrates that the mass transfer of highly soluble gases is not limited in the usual conditions occurring in anaerobic fermentors (low-intensity mixing). Conversely, the limitation is important for poorly soluble gases, such as methane and hydrogen. The latter could be overconcentrated to as much as 80 times the value at thermodynamic equilibrium. Such overconcentrations bring into question the biological interpretations that have been deduced solely from gaseous measurements. Experimental results obtained in three different methanogenic reactors for a wide range of conditions of mixing and gas production confirmed the general existence of low mass transfer coefficients and consequently of large overconcentrations of dissolved methane and hydrogen (up to 12 and 70 times the equilibrium values, respectively). Hydrogen mass transfer coefficients were obtained from the direct measurements of dissolved and gaseous concentrations, while carbon dioxide coefficients were calculated from gas phase composition and calculation of related dissolved concentration. Methane transfer coefficients were based on calculations from the carbon dioxide coefficients. From mass balances performed on a gas bubble during its simulated growth and ascent to the surface of the liquid, the methane and carbon dioxide contents in the gas bubble appeared to be controlled by the bubble growth process, while the bubble ascent was largely responsible for a slight enrichment in hydrogen.

Journal Article↗
PubMed1990

Somatosensory evoked potentials from median nerve; normative data.

The somatosensory evoked potentials from median nerve were studied in a group of 127 normal adults aged from 19 to 79. The latencies of elbow, Erb's, cervical N11 and N13 as well as cortical N20 and P25 potentials were analyzed as a function of height and age. Two central conduction times, N20-N11 and N20-N13, were equally studied. The corresponding regression formulae were calculated and can be used to predict normative values of these parameters over a wide range of height and age. Standard error estimates are given for all parameters.

Adult↗