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Biomedical subjects

P Perrier

Publications and source records attributed to P Perrier.

At least 37 records · Page 2Linked to original sources
PubMed1992

Acoustic and perceptual effects of changes in vocal tract constrictions for vowels.

The purpose of this study was to use vocal tract simulation and synthesis as means to determine the acoustic and perceptual effects of changing both the cross-sectional area and location of vocal tract constrictions for six different vowels: Area functions at and near vocal tract constrictions are considered critical to the acoustic output and are also the central point of hypotheses concerning speech targets. Area functions for the six vowels, [symbol: see text] were perturbed by changing the cross-sectional area of the constriction (Ac) and the location of the constriction (Xc). Perturbations for Ac were performed for different values of Xc, producing several series of acoustic continua for the different vowels. Acoustic simulations for the different area functions were made using a frequency domain model of the vocal tract. Each simulated vowel was then synthesized as a 1-s duration steady-state segment. The phoneme boundaries of the perturbed synthesized vowels were determined by formal perception tests. Results of the perturbation analyses showed that formants for each of the vowels were more sensitive to changes in constriction cross-sectional area than changes in constriction location. Vowel perception, however, was highly resistant to both types of changes. Results are discussed in terms of articulatory precision and constriction-related speech production strategies.

Adult↗
PubMed1991

Autosomal dominant arthropathy in a French family.

We studied a French family in which 18 adult members had destructive arthropathy and enthesopathic changes. In 16 patients, the diagnosis was verified radiologically, and in the 2 other patients, the clinical history was consistent with familial arthropathy. The disease predominantly affects the wrists, fingers, shoulders, and peripheral entheses, and its onset occurs after age 18. Genetic transmission is autosomal dominant, with 100% penetrance, and is not related to the HLA system. The clinical and radiologic features are strikingly similar in all patients in successive generations and different branches of the genealogic tree, and this suggests monogenic transmission.

Age Factors↗
PubMed1990

Evidence of mitochondrial impairment during cardiac allograft rejection.

NADH laser fluorimetry and mitochondrial oxigraphy were used to study myocardial oxidative energy metabolism during cardiac allograft rejection. Heterotopic cardiac transplantation was performed on Lewis rats; allografts (with Fischer rat donors) were compared with isografts (with Lewis rat donors). In vivo and in vitro assays were performed six days after transplantation. Myocardial NADH fluorescence was recorded in vivo from grafted hearts, at baseline; during brief, complete ischemia; and during reperfusion. Oxygen consumption of mitochondria isolated from both native and grafted hearts was determined. Neither baseline levels nor maximum ischemic levels of NADH fluorescence (F0 = k[NADH]) were found to be significantly different between allografts (0.45 +/- 0.05 to 0.87 +/- 0.10) and isografts (0.45 +/- 0.04 to 1.11 +/- 0.05). During recovery, the rate of fluorescence decrease was significantly lower in allografts than in isografts (0.024 +/- 0.001 vs. 0.038 +/- 0.002 delta F0.s-1, P less than 10(-3], indicating a lower rate of NADH reoxidation. In the presence of malate and glutamate substrates, mitochondrial O2 consumption was significantly lower in allografts than in isografts (30 +/- 9 vs. 100 +/- 15 nanoatoms O2. min-1.mg prot-1, P less than 10(-2]. These results indicate that mitochondrial oxidative metabolism was impaired during the rejection process. Such energy production disturbances may contribute to the dysfunction of rejecting hearts.

Animals↗
PubMed1987

The solid-state decarboxylation of the diammonium salt of moxalactam.

This paper reports studies of the solid-state chemistry of the diammonium salt of moxalactam. The methods employed include X-ray crystallography, molecular mechanics calculations, thermogravimetric analysis, and high-pressure liquid chromatography. The crystal structure shows that the malonic acid amide functionality in crystals of the diammonium salt is not planar. If the common decarboxylation mechanism is operating, then considerable rotation would be required for this functionality to attain coplanarity. Simultaneous HPLC and thermogravimetric analysis studies indicate that the decarboxylation of the diammonium salt of moxalactam is preceded by desolvation. Molecular mechanics calculations indicate that the barrier to rotation of the malonic acid amide functionality is relatively small in the dehydrated crystals, perhaps explaining the facile decarboxylation of this antibiotic. Alternatively, the amorphous desolvated crystals may allow enough molecular freedom for the malonic acid amide functionality to attain coplanarity and decarboxylate.

Chromatography, High Pressure Liquid↗
PubMed1987

Lack of linkage between HLA and multiple endocrine neoplasia type 2 in a French family.

In this study, linkage between HLA and a dominant gene determining multiple endocrine neoplasia type 2 (MEN 2) in a large pedigree was investigated. All lod scores for recombination fractions ranging from 0 to 0.45 were negative. If we pool data from our family and the families studied by Jackson et al. (1976) and Simpson & Falk (1982), a link between HLA and the locus for MEN 2 can be excluded. Linkage studies with various markers and pooled data should be pursued to permit detection of high risk individuals and to identify a genetic defect.

Genetic Linkage↗
PubMed1986

Coronary artery restenosis following transluminal coronary angioplasty.

Morphological changes are described in a case of coronary restenosis occurring three and ten months after transluminal coronary angioplasty. The lesions consisted of severe narrowing of the previously mechanically dilated coronary segments. This narrowing was produced by fibrocellular intimal hyperplasia associated with rupture of the media whereas the atheromatous plaque was not involved. This suggests that medial injury associated with healing intimal hyperplasia could be the major factor resulting in late coronary restenosis.

Angioplasty, Balloon↗
PubMed1986

[HLA and familial multiple sclerosis].

Some data suggest an environmental perhaps a viral factor but also of a genetic factor in the etiology of multiple sclerosis. Among the latter is the notably increased risk for a twin when the other twin has the disease, a risk further increased if they are monozygotic. There is also a greater than chance frequency of common HLA haplotypes in 2 affected siblings. The frequency of familial forms of multiple sclerosis is estimated at approximately 6 p. 100. We have studied 14 families of which 12 included 2 members with multiple sclerosis and 2 with 3 affected members. Parental relation between patients was parent to child (7 cases), brother to sister (5 cases), sister to sister including two pairs of twins (4 cases) and cousin to cousin on the mother's side (2 cases). When compared with non-familial multiple sclerosis there were no particular features in clinical disorders or course: 4 forms were progressive, the others evolving by episodes. In 26 patients in whom HLA antigens were determined, the DR2 antigen was present 19 times, the B7 antigen 9 times and the A3 antigen 7 times. In the 8 pairs of siblings with multiple sclerosis, 2 were HLA-identical and 5 semi-identical. One pair had no common haplotype. Grouping of HLA in 22 healthy members allowed 8 genealogic trees to be established. If a gene for susceptibility to multiple sclerosis exists, it is of low penetration, of dominant transmission and of limited frequency. It probably lies close to the region D of chromosome 6, because of the disequilibrium of crossed linking with A3, B7 and DR2 antigens.

Chromosome Mapping↗
PubMed1985

[Prevalence of anti-LAV antibodies in hemophiliacs, correlation with the immunological state].

49 french haemophiliacs (haemophilia A: 41 patients; haemophilia B: 8 patients) were serologicaly tested for LAV antibodies: 10 patients (20.4%) were seropositive including 9 (21.9%) with haemophilia A and 1 (12,5%) with haemophilia B. Between seronegative and seropositive patients total lymphocyte and T-lymphocyte sub-populations counts were not significantly different. The mean serum IgG level was higher and palpable lymphadenopathy more frequently encountered among seropositive patients.

Antibodies, Viral↗
PubMed1985

HLA antigens and toxic reactions to sodium aurothiopropanol sulphonate and D-penicillamine in patients with rheumatoid arthritis.

One hundred and forty-one patients with rheumatoid arthritis treated with aurothiopropanol sulphonate or D-penicillamine, or both were examined for HLA antigens to investigate the genetic influence on the occurrence of different adverse reactions during therapy. All 13 patients possessing HLA-DR3 had toxic reactions. The relative risk for DR3 positives of developing skin eruptions or proteinuria was calculated to be 10.5 times and seven times respectively that of DR3 negatives. The incidence of DR7 antigen in 94 patients with toxic reactions was significantly decreased (11% compared with 28% in controls) suggesting a protective role for this antigen.

Adult↗
PubMed1985

[Prenatal diagnosis of triploidy. II. Biological studies].

In three cases of triploïdy, the origin of extra haploid set is found by chromosomal and HLA markers. It does not confirm a relationship between paternal origin and partial hydatidiform mole. In case of prenatally diagnosed triploïdy, a protocol for biological studies is suggested.

Dosage Compensation, Genetic↗
PubMed1984

[Blood T lymphocyte populations in the hemophiliac].

We have studied a group of 31 hemophiliac patients (hemophilia A: 26 patients, hemophilia B: 5 patients); 29 healthy men were used as controls. Hemophiliac patients had increased percentages of suppressor T-lymphocytes and depressed T4/T8 ratios. These abnormalities were found to be significantly correlated with the amount of F VIII used per year.

Adolescent↗
PubMed1984

[Reoperations after surgical correction of tetralogy of Fallot].

Between 1970 and 1981, 40 patients (6%) were reoperated after surgical correction of Fallot's tetralogy. The average age of these patients was 7,5 years (range 2 months to 37 years). The usual anatomical form was present in 30 cases and severe forms accounted for the other 10 cases (pulmonary atresia with septal defect were excluded). The 40 patients were divided into 3 groups according to the anatomical lesions corrected at reoperation: Group I: 16 patients with a residual isolated VSD; Group II: 14 patients with one or two residual right heart anomalies (RRHA) but without a septal defect; Group III: 10 patients with a residual VSD and RRHA. The only clinical difference between the patients of these 3 groups was the delay of onset of symptoms: the patients with residual VSD (Groups I and III) often developed cardiac failure immediately, whilst in those without residual VSD (Group II) cardiac failure was usually observed secondarily. Four patients (10%) died early after reoperation (less than 1 month). Three others died later, two during a third operation. The total mortality was similar in the three groups. The surgical result was assessed clinically after an average follow-up of 4,5 +/- 3 years: patients with a residual isolated VSD (Group I) had the best long-term results. In 12 patients, M mode and 2D echocardiography showed normal left ventricular function but the ratio of end diastolic right ventricular and left ventricular dimensions was increased to an average of 0,72 +/- 0,2.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1983

[Botulism caused by preserved mushrooms].

We describe two cases of botulism caused by home-prepared under olive oil mushrooms. We stress the importance of an accurate anamnestic study and of the recovery of the toxic material for the diagnosis and therapy. The serological test on patient's blood, the isolation and the identification of botulinic toxin give the possibility to confer a specific character to the serotherapy The prevention of these toxic infections require a wide education on the preparation and storage of foods.

Adult↗