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Biomedical subjects

P Mercier

Publications and source records attributed to P Mercier.

At least 163 records · Page 9Linked to original sources
PubMed1988

Human castor bean allergy and HLA-A, B, C, DR.

Our results in 27 castor bean-allergic patients typed for HLA-A, B, C, DR antigens show (although the observed difference did not reach a statistical significance after correction for the number of tested specificities) an increase of A2 cross-reacting group antigens and, on the other hand, of HLA-A29, B39, CW2, B12, DR2, and especially DR5 (48.1% vs. 26.9% - chi 2 = 5.579; uncorrected p: 0.01 less than p less than 0.02), which possibly participate in haplotypic combinations. The facts that the markers of the haplotype segments involved are more frequent in northern European populations (e.g., A3,B7--Scandinavian; A29,B12--English) and that regional haplotypes are decreased (e.g., A11,B35) suggest that the allergics could in some geographical areas be less genetically adapted to their environment. In the same way, the fact that although the global number of assigned HLA antigens was increased, the percentage of only some alleles (among these those belonging to the A2-CREG) was increased suggests not only a recessive model but a diminution of the polymorphism in allergics. This is in agreement with the physiological role of the HLA system, the polymorphism of which, according to the numerous restriction phenomena allowed at the cellular level, represents broad possibilities of adapted immune response in man. In any event, these findings clearly suggest that HLA-DR5 and B39 may be the markers of castor bean allergy in the Mediterranean area, to which are superimposed the HLA alleles linked to the general atopic susceptibility.

Ricinus communis↗
PubMed1988

A 5-year prospective longitudinal study of tardive dyskinesia: factors predicting appearance of new cases.

In a 5-year longitudinal study in a cohort of 169 schizophrenic outpatients treated with neuroleptics, we found a twofold increase (from 22% to 44%) in prevalence of tardive dyskinesia (TD) meeting the Schooler and Kane research diagnostic criteria. If we include cases of TD that were considered definite but did not meet the research criteria, the prevalence increased from 31% to 58%. In the cohort of 131 patients who did not present with the disorder in 1975, we found parkinsonism and increase in parkinsonism to be the best predictors of subsequent development of the disorder. Poor schizophrenic prognosis and long treatment duration also appeared to be risk factors. Another finding was the importance of changes in neuroleptic and antiparkinsonian dosage in both covering and uncovering TD.

Adult↗
PubMed1987

Long-term results of mandibular ridge augmentation by visor osteotomy with bone graft.

Visor osteotomies of various designs, supplemented with illiac bone grafts, were used to augment 63 cases of severely atrophic mandibles. The rate of resorption measured on lateral cephalograms was 28% after four years, with the best performance by the full visor with peripheral bone graft (PA), and the worst by the short visor with onlayed bone graft posteriorly (PO). Ridge forms were usually inverted V-shaped or inverted U-shaped, but occasionally comma-shaped, the best form for providing retentive qualities for the denture. Only 39% were free of neurosensory problems. It was concluded that indications for such a procedure should be viewed in the light of frequent nerve injuries, adverses patterns of resorption for denture retention and newer and more effective methods for ridge augmentation using hydroxylapatite.

Alveolar Ridge Augmentation↗
PubMed1987

Cold reacting antilymphocyte antibodies in type I (insulin dependent) diabetes.

Non HLA antilymphocyte antibodies have been detected in numerous auto-immune illnesses and notably in type I (insulin dependent) diabetes. In order to ascertain their role in this illness, the actual frequency of this phenomenon has been estimated. The privileged cellular target has been determined. Finally correlations with the other immunogenetic markers of diabetes have been investigated. Non HLA antilymphocyte antibodies are frequent, above all at the beginning of the illness (32.4% before 6 months, 10% after 5 years). The cellular target is mainly composed of B lymphocytes. B lymphocyte enrichment of cellular suspensions leads to better method sensitivity (70.3% positive reactions at the beginning of the illness). No correlation was found with presence of anti islet cell antibodies or anti coxsackie B virus antibodies (IgM). Association with the HLA DR3 phenotype is relatively frequent but does not attain statistical significance.

Adult↗
PubMed1987

Elaboration of neutral proteoglycanase by growth-plate tissue cultures.

This report describes the properties of a neutral protease that was synthesized and secreted into medium by intact cartilaginous growth plate in tissue culture. Bovine cartilaginous growth plate was grown for seven days in tissue culture, during which time the chondrocytes remained viable and metabolically active as determined by quantitation of trypan-blue exclusion and incorporation of 3H-cytidine. Protease activity, assayed by viscometry using proteoglycan monomer from cartilage as a substrate, was absent on day 1 but was present at high levels on days 2 through 5. The protease activity did not require activation and was highest at neutral and alkaline pH. Protease activity was abolished by twenty-millimolar EDTA but was unaffected by pepstatin, iodoacetate, and soybean trypsin inhibitor. In contrast to the high levels of activity of neutral protease that were present in tissue cultures of the intact growth plate, no protease activity could be detected when chondrocytes from the cartilaginous growth plate were grown in cell culture, even after sonication of the cells or activation with aminophenyl mercuric acetate or trypsin. Since hypertrophic chondrocytes probably do not survive the disruption of tissue that is involved in establishing cell cultures, these observations suggest that neutral protease is probably released into the medium by the hypertrophic chondrocytes that are present in the cultures of cartilaginous growth-plate tissue. It appears that the organization of the growth plate in tissue culture, as well as the maturation of proliferating chondrocytes into hypertrophic chondrocytes in tissue culture, may be required for synthesis of the neutral protease and its extracellular secretion by hypertrophic chondrocytes.

Alkaline Phosphatase↗
PubMed1986

Injuries associated with off-road vehicles among children.

Off-road vehicles have attained growing popularity, expanding markets and increasing rates of associated injury, especially among young people. In 1984-85, 148 patients were treated at the Children's Hospital of Eastern Ontario, Ottawa, for injuries suffered in off-road vehicle accidents. The average age of the patients was 14 years. Soft-tissue injuries occurred in 33 patients, 21 of whom had severe injuries. There were 179 fractures in 133 patients. One patient died as a result of his injuries. The most common mechanism of injury was losing control of and tumbling from the machine. Seventeen patients were struck by their own vehicles, and 39 collided with objects such as cars, trees or people. The health care costs of these accidents are no less serious than the concerns for the appropriate legislation to protect consumers, particularly the young.

Accidents, Traffic↗
PubMed1986

IgM antiplatelet antibodies in 7 out of 20 rheumatoid arthritis sera. A new antiplatelet antibody ELISA. Reverse correlation with anti-B-lymphocyte antibodies in the same sera.

In a previous work, we had found that anti-B lymphocyte antibodies exist in rheumatoid arthritis. To investigate whether these antibodies were directed against surface immunoglobulins or not we have investigated if RA sera could recognize similar structures on other targets such as platelets (on which immunoglobulins and immune complexes are present) by a new ELISA method. No IgG antiplatelet antibody was found in 20 RA sera. But 7 out of these 20 RA sera had IgM antiplatelet antibodies when tested on platelets from 5 donors. The comparison of the positivities of these sera on B lymphocytes and platelets from the same donors showed a statistically significant reverse (X2 = 20,008, p much less than 0.0001) correlation. The target antigen and the meaning of these IgM antiplatelet antibodies, which seem to be associated with severe RA, is still under investigation.

Antibody Specificity↗
PubMed1986

Visor osteotomy augmentation of the mandible with posterior onlay bone graft or with hydroxylapatite: a comparative study.

A frequent and severe ridge atrophy, the anterior spheroid basal bone with posterior bilateral concavities of the mandible, has been defined. Two groups of sixteen patients who had residual ridge augmentation of the mandible with two different techniques were studied. The visor osteotomy with posterior hydroxylapatite was superior to the visor with posterior onlay bone graft in terms of ridge form, bone resorption, patient satisfaction, and neurosensory disturbances. Nevertheless, there remained some problems of anterior resorption and backward rotation of the visor segment for both techniques and of posterior resorption with the partial onlay bone graft.

Adult↗
PubMed1986

Bombesin-like immunoreactivity in bovine adrenal medulla.

The presence of immunoreactive (ir)-bombesin in bovine adrenal medulla, isolated adrenal chromaffin cells and subcellular fractions of the adrenal medulla was demonstrated using a specific antibody to the synthetic peptide. High levels of ir-bombesin were detected in acid (HCl) extracts of the adrenal tissue (27 pmol/g) and isolated cells (0.35 pmol per 10(6) cells). Subpopulations of adrenal chromaffin cells were also obtained by centrifugation of the original cell preparation through a stepwise bovine serum albumin gradient (cell layers I, II and III). The highest concentration of ir-bombesin (0.77 pmol/10(6) cells) was found in a cell population (cell layer I) enriched in noradrenaline (adrenaline/noradrenaline ratio of 0.6). At the subcellular level, ir-bombesin was mainly concentrated in the secretory granules (0.61 pmol/mg protein) along with catecholamines (1097 nmol/mg protein), but a relatively high concentration of ir-bombesin (0.26 pmol/mg protein) was also found in the microsomal fraction. Isolation and high performance liquid chromatography (HPLC) analysis of adrenomedullary ir-bombesin revealed the presence of four molecular forms, one of them corresponding to gastrin releasing peptide (GRP), another one (major peak) eluting closely to synthetic neuromedin B and another one coeluting with GRP-(18-27). HPLC analysis of the molecular forms of ir-bombesin in the microsomes and secretory granules indicated that GRP- and neuromedin B-like materials can be generated between the two fractions.

Acetylcholine↗
PubMed1986

Bromazepam and lorazepam in generalized anxiety: a placebo-controlled study with measurement of drug plasma concentrations.

Sixty outpatients with a diagnosis of generalized anxiety were randomly assigned to 4 weeks of treatment with bromazepam, lorazepam or placebo, following a 1-week placebo washout period. There was no significant difference in the anxiolytic effects of bromazepam and lorazepam, both of which were superior to placebo. However, lorazepam-treated patients tended to have a more depressed mood than those treated with bromazepam. Drug-treated patients had consistently less cognitive impairment than those treated with placebo, the difference being statistically significant (P less than .05) in the case of bromazepam. The most frequent side-effects reported with each drug were drowsiness, which tended to subside with time, and depression, which tended to emerge toward the end of the 4-week period. There was a positive correlation (r = 0.64) between age and bromazepam plasma concentration per unit dose, adjusted for weight, and a negative correlation (r = -0.50) between weight and lorazepam plasma concentration per unit dose, adjusted for age.

Adolescent↗