Biomedical subjects
Publications and source records attributed to J Mercier.
This software program adds two very interesting data to the usual results of exercise testing: an estimation of cardiac output according to the most recent validations and a reliable estimation of alveolar ventilation. The main advantage of this additional ventilatory and cardiovascular information using the same data: end-tidal PCO2.
In order to judge the effect of moderate sports training on the anthropometric characteristics and aerobic capacity of boys before and during puberty, a comparative study was conducted of 140 children, 94 of whom were not undergoing any specific training and 45 of whom were spending more than 3 hours a week practising swimming. The boys were divided into three maturity groups according to pubic hair status: prepubertal, pubertal, and end of puberty. The study shows greater maximal oxygen uptake in absolute terms, body weight, lean body mass, chest circumference, arm circumference, and arm muscle area for the swimmers. The morphological differences between the swimmers and non-swimmers concern physical characteristics generally involved in swimming. The difference in aerobic capacity, however, may be in part due to the morphological changes engendered by training; a longitudal study would confirm this. It is suggested that anthropometric indicators of arm muscles may be used in the biological supervision of swimming training.
Molecular cloning of DNA fragments permitted the isolation of structural genes coding for SHV-1, SHV-2, OHIO-1, and OXA-6 beta-lactamases. DNA probes were constructed for SHV-1, and under conditions of high stringency, hybridization was observed only between SHV-1 and SHV-2. Oligonucleotide typing with a 15-mer SHV-1 probe was capable of discriminating between SHV-1 and SHV-2 but not OHIO-1. The nucleotide sequence of the SHV-1 beta-lactamase gene from plasmid R974 has been determined. The structural gene encodes a polypeptide product which differs by 9 residues from the p453 (SHV-1) PIT-2 enzyme determined by peptide sequencing. The significance of each mutation was assessed by alignment of amino acid sequences and comparisons with the Staphylococcus aureus PC1 penicillinase crystal structure. Structural similarities between SHV-1 and class A beta-lactamases are extensive, with amino acid identities of 88.9% between SHV-1 and LEN-1, 91.8% between SHV-1 and OHIO-1, and 63.7% between SHV-1 and TEM-1.
A novel discrete mobile DNA element from Tn21 from the plasmid R100.1 is described, and its mobilization function was confirmed experimentally. In addition, the element behaves as a recombinase-active locus (tnpI) which facilitates insertions of antibiotic resistance genes as modules or cassettes at defined hot spots or integration sites. A similar tnpI sequence was detected by DNA hybridization in a series of beta-lactamase transposons and plasmids and localized on their physical maps. The genetic function of the locus cloned from Tn21 into pACYC184 was tested for conduction and integration into the plasmids R388 and pOX38Km, and the results suggested recombinase-integrase activity and recA independence. DNA sequence analysis of the tnpI locus revealed no inverted or direct terminal repeats or transposition features of class I and class II transposons. The coding capacity revealed three putative open reading frames encoding 131, 134, and 337 amino acids. Orf3 encoded a putative polypeptide product of 337 amino acids that shared highly significant identity with the carboxyl region of integrase proteins. A comparison and an alignment of the tnpI locus from Tn21 and its flanking sequences identified similar sequences in plasmids and in transposons. The alignment revealed discrete nucleotide changes in these tnpI-like loci and a conserved 3' and 5' GTTA/G hot spot as a duplicated target site. Our data confirm the remarkable ubiquity of tnpI associated with antibiotic resistance genes. We present a model of transposon modular evolution into more complex multiresistant units via tnpI and site-specific insertions, deletions, and DNA rearrangements at this locus.
The so-called benign lympho-epithelial lesion (BLEL) of the parotid is a rare condition. Its diagnosis is based on histology. For a long time there have been problems with its classification and prognosis: classification since certain cases may be classified as Sjögren's syndrome or as a precursor of the latter, prognosis there may be recurrence, contralateral involvement or progression to non-hodgkin's lymphoma. The authors discuss these factors in 8 cases and propose total parotidectomy with facial nerve preservation as the treatment of choice.
The purpose of this study was to determine the effect of starting the force-velocity test with a heavy load on both maximal anaerobic power and blood lactate concentration. Nine male subjects aged 23.4 +/- 1.3 yr (mean +/- sem) participated in a first force-velocity test (FV1) which had an initial load of 1 kg (classical protocol). Then a week later in a second force-velocity test (FV2) which had an initial load corresponding to maximal power developed during FV1 (W1). The increase in load was of 1 kg for FV1 and FV2. Our results show that during FV2, compared to FV1: 1) maximal anaerobic power developed (W2) is superior to W1 (W1 = 1,165.2 +/- 70.4 W; W2 = 1,278.6 +/- 92.3 W; p less than 0.02); 2) blood lactate concentration after the first load is inferior (p less than 0.001); 3) blood lactate concentration is not significantly different at the peak of power. Thus, starting the force-velocity test with a heavy load allows an increase of maximal anaerobic power until a blood lactate concentration which may be compared to the one obtained during the classic force-velocity test. In conclusion, maximal anaerobic power measured during the force-velocity test seems to depend on protocol used.
The diagnosis of smoking-related chronic obstructive pulmonary disease (COPD) is often made too late. Could the study of breathing pattern during exercise testing help in earlier detection. In order to test this hypothesis, we studied 34 asymptomatic smokers (S) compared to 55 nonsmoking controls (NS). The subjects, divided into 3 age groups (30-60 yr), were comparable in terms of anthropometric and spirometric characteristics. The smokers from 30-50 yr had a lower VO2max than the controls (p less than 0.01) whereas the older smokers (50-60 yr) had a VO2max comparable to that of the controls. The study of breathing pattern indicated rapid, shallow breathing by all smokers. Thus exercise testing, and the abnormalities observed in breathing pattern, would seem to help in early detection of COPD in asymptomatic smokers.
Pierre Robin syndrome is typically characterized by glossoptosis and retrognathia associated with cleft palate, respiratory and deglutition disturbances. Two morphological tendencies arise out of this 70-patient series, 50 of whom were managed with the same therapeutical regimen, which included labioglossopexy and was associated with only one case of death: "deforming" type Pierre Robin syndrome most commonly follows a favorable course with respect to both function and facial deformations, provided labioglossopexy is carried out sufficiently early. Indeed, this surgical operation allows for prompt restoration of normal function, thereby limiting the dysfunction-deformation vicious circle. This form of Pierre Robin syndrome may find its origin in the embryo's abnormal amniotic environment. "Malformation"-associated Pierre Robin syndrome often presents with combined anomalies, respiratory disturbances that may evolve into severe airway problems, impaired deglutition and abnormal brain development; in most cases, labioglossopexy will dramatically improve the immediate state of the child, although long-term prognosis as regards malformation is rather guarded.
This study was conducted in order to assess the activity of trimetazidine dosed at 60 mg/day in patients presenting degenerative loss of hearing. Ten centers participated in this multicenter double-blind placebo-controlled trial which spanned 6 months. Included were 251 patients (118 women, 133 men) presenting with pure perception bilateral symmetrical deafness concerning predominantly the acute frequency range. 228 patients terminated the study, including 115 in the trimetazidine group and 113 in the placebo group. The evolution over a 6-month treatment period was significantly better with trimetazidine as regards the following parameters: audibility as assessed by pure-tone audiometry, namely at the acute frequency range (p = 0.002), intelligibility as assessed by speech audiometry (p = 0.008), subjective evaluation of hearing loss and its impact on the patient's social life. Results confirm the value of trimetazidine hearing loss management, based on clinical, subjective criteria as well as audiometric ones. Parameters reflecting best trimetazidine's efficacy were intelligibility and the psychological/behavioral impact of the impairment, allowing for better social integration of the subject.
There have been few works studying the effects of training in asthmatics and there does not yet exist any study utilising the idea of the individualization of training. This is why the aim of this study was to assess the value of the effects of individualised aerobic training on cardio-respiratory aptitude in the asthmatic child. This study was carried out on two populations of asthmatics, swimmers and non-swimmers matched for age, height, degree of bronchial obstruction during a remission and baseline of physical fitness. Each child in the swimming group was trained to a metabolic level corresponding to the ventilatory threshold. After a period of 3 months a second cardio-respiratory evaluation was carried out. A clear cut improvement (20%) of VO2 max was observed as well as a proportional elevation of the ventilatory threshold in the swimming group. The VE max, the VT max, the VT/Timax, the FC max and the maximal oxygen uptake were also recorded. On the other hand aerobic training seems to be without effect on resting pulmonary function, even if the clinical state of the children improved. In conclusion this study shows that aerobic training closely adapted to the level of each child, obtains an important and rapid gain in cardio-respiratory fitness which leads to a better exercise adaptation. In addition the progression of the ventilatory threshold implies an increased capacity for work without the appearance of hyperventilation. This enables an understanding of how aerobic training is generally accompanied in the asthmatic with a better respiratory comfort and argues in favour of the perfect efficacy of this type of reconditioning in the re-adaptation to effort in these patients.
Mandibular condylectomy is one of the methods to which one must sometimes resort when treating temporomandibular joint dysfunction. As emphasized by Merville, this is the conventional method used whenever dealing with condylar hypertrophy , as well as in certain grade-III cases with deep bite. However, another interesting indication for it is the horizontal configuration of the occlusal plane, leading to pain and/or luxation. This type of surgical joint operation presents no risk whatsoever, provided the meniscus is respected.
The aim of this study was to specify in young trained swimmers, during progressive exercise, whether different aerobic physical fitness goes along with differences in breathing pattern and in mouth occlusion pressure used as a non-invasive index of neuromuscular output. Ten children (aged 10.5-16 years) with high VO2 max (57.6 +/- 3.6 ml.min-1.kg-1) and ten children (aged 11-17 years) with moderate VO2 max (44 +/- 3.8 ml.min-1.kg-1) realized a maximal exercise test on a cycle ergometer. During the last minute of each power level we measured the following parameters: VO2, VCO2, VEBW, f, VTBW/TI,TI/TTOT, as well as mouth occlusion pressure (P0.1) and 'effective impedance' of the respiratory system (P0.1/VTBW/TI). Our results showed that at a same VCO2, children with high VO2 max had significantly lower P0.1, P0.1/VTBW/TI and f than children with moderate VO2 max and same VEBW/TI. At different levels of VO2, in the twenty children of the two groups, we have found significant correlations between VO2 max of each subject and P0.1 (P less than 0.01), P0.1/VTBW/TI (P less than 0.001). At a same VO2, children with a higher VO2 max showed significantly lower P0.1, P0.1/VTBW/TI at all levels of VO2 and lower VEBW and VTBW/TI at high level of VO2. At a same VE, the two groups of children showed the same values of VT/TI and f. In conclusion this study shows first, that different aerobic physical fitness does not go along with different breathing pattern, and second, that swimmers with high physical fitness have a lower ventilatory response to exercise but a higher ventilatory and neuromuscular efficiency during exercise than children with moderate physical fitness.
Six types of plasmid-mediated carbenicillinases can be distinguished on the basis of their substrate profiles, molecular mass isoelectric values and immunological properties. As yet, no structural classification has been attempted for these enzymes at the molecular level. We have isolated the PSE-4 structural gene responsible for carbenicillinase production in Pseudomonas aeruginosa strain Dalgleish and studied its expression in E. coli. A detailed physical map of the cloned fragment and the construction of deletion mutants permitted the precise localization of the PSE-4 structural gene. Various restriction endonuclease fragments known to be flanking or internal to the PSE-4 bla gene were used as DNA probes and tested for homologous sequences in other beta-lactamase genes. A collection of three restriction fragment probes internal or delimiting the PSE-4 structural gene were hybridized with purified plasmid DNA coding for 18 other beta-lactamases. Under high stringency conditions, only the PSE-1, CARB-3 and CARB-4 genes cross-hybridized with PSE-4; while one of the probes tested hybridized solely with CARB-3. Further analysis indicated that the PSE-1, PSE-4, CARB-3 and CARB-4 bla genes are related and could presumably have evolved from a common progenitor.
The ramus of the mandible appears with the cephalic hominisation phenomenous during phylogenesis and determines the vertical posterior height of the face. Among the three skeletal units that form it, the condylar one is responsible of this height and of the level of the posterior part of the occlusal plane. So, all congenital, constitutional or acquired diseases concerning this unit, give a change of the vertical posterior height of the face. The excess troubles ar essentially represented by the condylar hyperplasia, usually unilateral and treated by condylectomy. The vertical posterior insufficiency may be unilateral or bilateral. The former looks like a mandibular asymmetry whereas the latter looks like an anterior vertical excess with or without a Class II malocclusion. If the condyle is absent or T.M.J. destroyed like in ankylosis, the authors use the costo-chondral graft to repair it. But in condylar hypoplasia, they use a vertical osteotomy of the ramus for lengthening the ramus. The three-dimensional architectural analysis is very useful for studying the vertical posterior height of the face and his changes.
The evolution of blood lactate concentrations has been studied during a force/velocity test on a cycloergometer in order to specify if the repetition of short (6 s) and intense exercises induced an important participation of lactic anaerobic metabolism. Seven moderately trained male subjects, aged from 23 to 29 years (mean = 24.92 +/- 0.79) participated in this study. Two blood samples (venous catheter) were performed, at rest, then for each work load (1 kg to 10 kg): at the end of the exercise (P1) and during the recovery at 5 min (P2). From the lowest work load, blood lactate concentration increased significantly, at the end of the exercise (F = 16.21; P less than 0.001) and during the recovery (F = 22.62; P less than 0.001). The mean values were respectively at the peak of power: 9.84 +/- 0.85 et 10.19 +/- 0.75 mmol.l-1. Once the peak of power was obtained, the blood lactate concentration remained steady. In conclusion, the repetition of short and intense exercises induced an important participation of lactic anaerobic metabolism. The lactate could be the limiting factor of the maximal power.
Serum samples from 37 patients with cystic fibrosis (CF), whose lungs were colonized by Pseudomonas aeruginosa, were tested in a 1 yr prospective study to examine a possible relationship between levels of circulating immune complexes (CIC) and the following parameters: level of specific antibodies to P. aeruginosa; relative importance of P. aeruginosa mucoid and non-mucoid strains isolated from sputum; the forced expiratory volume (FEV1; percentage predicted); the chest X-Ray score (Brasfield system) and the clinical score (Shwachman system). Reactivity of CIC against P. aeruginosa, Staphylococcus aureus, Haemophilus influenzae and Escherichia coli antigens were also assayed. We found that the FEV1, the chest X-Ray and the clinical scores were significantly lower in patients with high levels of CIC than in those with normal levels of CIC (p less than 0.001 for each). We also found that the level of IgG antibodies against P. aeruginosa was significantly higher (p less than 0.001) in patients with high levels of CIC than in those with normal levels of CIC. 78% of patients with high levels of CIC had predominantly mucoid P. aeruginosa isolates whereas only 21% of patients with normal levels of CIC had also predominantly mucoid P. aeruginosa isolates. Specific antibodies to P. aeruginosa were detected in all CIC isolated by polyethylene glycol precipitations from CF patients exhibiting both high levels of CIC and inferior pulmonary status. Our findings support the hypothesis that a high level of CIC in association with an aggressive humoral response to P. aeruginosa correlates with defective pulmonary status in cystic fibrosis.(ABSTRACT TRUNCATED AT 250 WORDS)
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It is not unusual to find patients who have lost posterior teeth or who are totally toothless, approaching our dental surgeon colleagues in cases of difficulties, and even prosthetic impossibility, nearly always associated or in relation with skeletic maxilo-mandibular imbalance. Orthognatic surgery of the toothless should thus satisfy the essential need for prosthesis but should also re-establish the unbalanced facial architecture which can be the only guarantee of a stable result. This therefore requires true pre-prosthetic surgery in which clinical analysis, cranial-facial architectural analysis and great care in making the provisional and final prosthesis, constitute the essential stages of diagnosis and therapy.