[Dental malocclusions. Diagnostic orientation].
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Adolescent↗
Biomedical subjects
J Mercier
Publications and source records attributed to J Mercier.
Age and training effects on the lactate kinetics of master athletes during maximal exercise.
To study the effects of age and training on lactate production in older trained subjects, the lactate kinetics of highly trained cyclists [HT, n = 7; 65 (SEM 1.2) years] and control subjects with low training (LT, n = 7) and of similar age were compared to those of young athletes [YA, n = 7; 26 (SEM 0.7) years], during an incremental exercise test to maximum power. The results showed that the lactacidaemia at maximal oxygen uptake (VO2max) was lower for HT than for LT (P < 0.05) and, in both cases, lower than that of YA (P < 0.001). The respective values were HT: 3.9 (SEM 0.51), LT: 5.36 (SEM 1.12), and YA: 10.3 (SEM 0.63) mmol.l-1. At submaximal powers, however, the difference in lactacidaemia was not significant between HT and YA, although the values for lactacidaemia at VO2max calculated per watt and per watt normalized by body mass were significantly lower for HT (P < 0.001) and LT (P < 0.02). These results would indicate that the decline in power with age induced a decline in lactacidaemia. Yet this loss in power was not the only causative factor; indeed, our results indicated a complementary metabolic influence. In the older subjects training decreased significantly the lactacidaemia for the same submaximal power (P < 0.01) and from 60% of VO2max onwards (P < 0.05); as for YA it postponed the increase and accumulation of lactates. The lactate increase threshold (Thla-,1) was found at 46% VO2max for LT and at 56% VO2max for HT.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Breathing pattern and ventilatory response to CO2 during exercise.
The aim of this study was to determine during moderate exercise whether response to the CO2 rebreathing test was dependent on differences in breathing pattern components among individuals recorded before the test and whether differences in tidal volume response and/or breathing frequency response to CO2 during the test could influence their ventilatory response to CO2. Ten healthy, sedentary male subjects, 20 to 34 years old, participated in the study. Ventilatory response to CO2 was measured by the CO2 rebreathing method (7% CO2, 50% O2). The measurements of breathing pattern components and CO2 rebreathing were made during mild steady state exercise: VCO2 = 20 ml.kg-1.min-1. We measured the following: 1) tidal volume (VTex) and breathing frequency (fex) before CO2 rebreathing and 2) ventilatory response to CO2 (SVEex), tidal volume response to CO2 (SVTex), and breathing frequency response to CO2 (Sfex) during the CO2 rebreathing test. The results showed that SVEex was correlated with VTex (r = 0.89, p less than 0.001), fex (r = -0.79, p less than 0.01), and Sfex (r = 0.83, p less than 0.01). There was no correlation between SVEex and SVTex. A curvilinear relationship existed between SVEex and alveolar ventilation calculated during exercise (r = 0.87, p less than 0.001), but there was no correlation with dead space. Sfex was positively correlated with VTex (r = 0.68, p less than 0.05) and negatively with fex (r = -0.70, p less than 0.05). We concluded that, during moderate exercise, higher tidal volumes measured before CO2 rebreathing were associated with higher response to the CO2 rebreathing test and consequently with higher ventilatory response to CO2.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Maximal anaerobic power: relationship to anthropometric characteristics during growth.
The purpose of this study was to determine the effects of age in relation to anthropometric characteristics upon maximal anaerobic power of legs in sixty-nine young boys aged 11 to 19 years. Maximal anaerobic power (Wmax) was measured by the force-velocity test. Lean body mass (LBM) was determined from all four skin-fold thickness measurements, leg volume (LV) was estimated by anthropometric method, and anthropometric measurements were used to determine total muscular mass (TMM). Wmax increased significantly (F = 44.1, p less than 0.001) between 11 and 19 years and was correlated with LV (r = 0.84) and TMM (r = 0.88). It was most highly correlated with LBM (r = 0.94), which best explained the percentage of the total variance of Wmax (88%). Normalized Wmax (Wmax/LBM) also increased significantly between 11 and 19 years (F = 21.9, p less than 0.001). In conclusion, Wmax determined by the force-velocity test was closely related to anthropometric characteristics, especially LBM, during the growth period. Furthermore, even when corrected for lean body mass, maximal anaerobic power was always found to increase. This suggests that other undetermined factors, in addition to the amount of lean tissue mass, may explain the increase of Wmax during the force-velocity test.
Adolescent↗
[Biopsy of the salivary glands. The importance and technic of biopsy of the sublingual gland on its anterio-lateral side].
A new method of taking a sublingual gland sample is suggested by the authors in the fore pole. They emphasize on this straightforward operating act and on the amount of tissue removed. The aim of the removal could be etiologic within the framework of the Gougerot-Sjögren's syndrome, diagnostic in the sarcoidosis and rheumatoid arthritis, prognostic in the graft versus host disease.
Biopsy↗
[Relation between the change of slope of heart rate and second lactic and ventilatory thresholds in muscular exercise with large load].
The time-course of heart rate, blood lactate, and ventilatory gas exchange was studied during an incremental exercise test on cycloergometer in order to ascertain whether heart rate deflection occurred at the same load as the second lactate S[La]2) and ventilatory (SV2) thresholds. Twelve moderately trained subjects, 22 to 30 years old, participated in the study. The initial power setting was 30 W for 3 min with successive increases of 30 W every min except at the end of the test where the increase was reduced to 20 and 10 W.min-1. Ventilatory flow (VE), oxygen uptake (VO2), carbon dioxide production (VCO2, ventilatory equivalents of O2 (EO2 = VE/VO2) and CO2 (ECO2 = VE/VCO2), and heart rate (HR) were determined during the last 20 s of every min. Venous blood samples were drawn at the end of each stage of effort and analyzed enzymatically for lactate concentration ([La]). The HR deflection, S[La]2, and SV2 were represented graphically by two investigators using a double blind procedure. Following the method proposed by Conconi et al. 1982, the deflection in HR was considered to begin at the point beyond which the increase in work intensity exceeded the increase in HR and the linearity of the work rate/HR relationship was lost. S[La]2 corresponded to the second breaking point of the lactate time-course curve (onset of blood lactate accumulation) and SV2 was identified at the second breaking point in the increase in VE and ventilatory equivalent for O2 uptake accompanied by a concomitant increase in ventilatory equivalent for CO2 output. We observed that the deflection point in HR was present only in 7 subjects. The work load, VO2, HR, and [La] levels at which heart rate departed from linearity did not differ significantly from those determined with S[La]2 ans SV2. The VO2 and HR values at HR deflection point were significantly correlated with those measured at S[La]2 and SV2. It is concluded that deflection in heart rate does not always occur, and when it does, it coincides with the second lactate and ventilatory gas exchange thresholds. It can thus be used for the determination of optimal intensity for individualized aerobic training.
Adult↗
[Morphological accidents other than labio-maxillary clefts].
In neonates and infants facial and/or craniofacial involvement occurs in a large number of malformative syndromes the pathogenesis of which is obscure in most cases. This, added to clinical polymorphism, hinders all attempts at classification. However, chromosomal aberrations, as demonstrated by karyotype analysis, can be distinguished from other congenital conditions where the predominant site of the anomaly may help clinicians in their research. Thus, among congenital syndromes of probable genetic origin, the author studies those that are most frequent or most characteristic, i.e. craniostenosis (or craniofaciostenosis) with its neurocerebral risk; lesions that are predominant in the upper part of the face (osteochondrodysplasia, systematized neurocristopathies); lesions affecting mainly the lower part of the face (bilateral and unilateral mandibular lesions) and anomalies of the tongue. Among syndromes of epigenetic origin, only alcoholic embryofoetopathy is presented. Diagnosing such morphological accidents does not only suggest possible cranial and/or dentofacial therapeutic measures, sometimes applied at an early stage, but it also enables clinicians to inform, whenever possible, the parents on the potential genetic risk.
Child, Preschool↗
Influence of anthropometric characteristics on changes in maximal exercise ventilation and breathing pattern during growth in boys.
The aim of this study was to investigate the effect of growth on ventilation and breathing pattern during maximal exercise oxygen consumption (VO2max) and their relationships with anthropometric characteristics. Seventy six untrained schoolboys, aged 10.5-15.5 years, participated in this study. Anthropometric measurements made included body mass, height, armspan, lean body mass, and body surface area. During an incremental exercise test, maximal ventilation (VEmax), tidal volume (VTmax), breathing frequency (fmax), inspiratory and expiratory times (tImax and tEmax), total duration of respiratory cycle (tTOTmax), mean inspiratory flow (VT/tImax), and inspiration fraction (tI/tTOTmax) were measured at VO2max. A power function was calculated between anthropometric characteristics and ventilatory variables to determine the allometric constants. The results showed firstly, that VEmax, VTmax, tImax, tEmax, tTOTmax, and VT/tImax increased with age and anthropometric characteristics (P less than 0.001), fmax decreased (P less than 0.001), and tI/tTOTmax remained constant during growth; secondly that lean body mass explained the greatest percentage of variance of VEmax (62.1%), VTmax (76.8%), and VT/tImax (70.6%), while anthropometric characteristics explained a slight percentage of variance of fmax and timing; and thirdly that VEmax, VTmax, and VT/tImax normalized by lean body mass did not change significantly with age. We concluded that at VO2max there were marked changes in ventilation and breathing pattern with growth. The changes in VEmax, VTmax, and VT/tImax were strongly related to the changes in lean body mass.
Adolescent↗
Blood lactate increase during the force velocity exercise test.
Venous blood lactate concentration was measured during the force velocity exercise test in order to determine whether this test is strictly alactic or whether it draws upon lactic anaerobic metabolism. Nine trained male subjects, aged from 23 to 29 years, participated in this study. Two blood samples were drawn at rest, and then for each work load (1 kg to 10 kg): at the end of each sprint (S1) and at the 5th minute of recovery (S2). From the first braking force, venous blood lactate concentration increased very significantly during the force velocity test (p less than 0.001) and, once the peak of power has been obtained, the venous blood lactate concentration remained steady. The lactate increase for each load (delta[LA]) decreased significantly (p less than 0.01). From the beginning of the exercise to the peak of power, a significant positive correlation between the increase of power and the increase of blood lactate concentration measured at S2 existed (r = 0.71, p less than 0.001), whereas there was a negative correlation between the decrease of delta[LA] and the increase of power (r = -0.45, p less than 0.01). In conclusion, the repetition of sprints during the force velocity test induced a recruitment of lactic anaerobic metabolism. Maximal power must be considered as an alactic and lactic anaerobic power. The consequences of lactate accumulation in muscle may be a limitation of the maximal anaerobic power.
Acceleration↗
Effect of resistive loads on pattern of respiratory muscle recruitment during exercise.
In healthy subjects, we compared the effects of an expiratory (ERL) and an inspiratory (IRL) resistive load (6 cmH2O.l-1.s) with no added resistive load on the pattern of respiratory muscle recruitment during exercise. Fifteen male subjects performed three exercise tests at 40% of maximum O2 uptake: 1) with no-added-resistive load (control), 2) with ERL, and 3) with IRL. In all subjects, we measured breathing pattern and mouth occlusion pressure (P0.1) from the 3rd min of exercise, in 10 subjects O2 uptake (VO2), CO2 output (VCO2), and respiratory exchange ratio (R), and in 5 subjects we measured gastric (Pga), pleural (Ppl), and transdiaphragmatic (Pdi) pressures. Both ERL and IRL induced a high increase of P0.1 and a decrease of minute ventilation. ERL induced a prolongation of expiratory time with a reduction of inspiratory time (TI), mean expiratory flow, and ratio of inspiratory to total time of the respiratory cycle (TI/TT). IRL induced a prolongation of TI with a decrease of mean inspiratory flow and an increase of tidal volume and TI/TT. With ERL, in two subjects, Pga increased and Ppl decreased more during inspiration than during control suggesting that the diaphragm was the most active muscle. In one subject, the increases of Ppl and Pga were weak; thus Pdi increased very little. In the two other subjects, Ppl decreased more during inspiration but Pga also decreased, leading to a decrease of Pdi. This suggests a recruitment of abdominal muscles during expiration and of accessory and intercostal muscles during inspiration. With IRL, in all subjects, Ppl again decreased more, Pga began to decrease until 40% of TI and then increased.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
The effect of institutionalization on nursing home populations.
Two groups of institutionalized aged, the mentally ill and the frail elderly, were studied for differences in observable behaviors. The mentally ill group showed no significant decline in behavior as years spent in an institution increased. This finding reflects improvement in mental health care. The mentally ill nursing home resident does need to be maintained on appropriate psychotropic medications. Limit-setting approaches to caregiving will help maintain expected behaviors. The frail elderly showed a decline in neatness and an increase in negative behaviors with longer institutional stays. Caregiving needs to focus on helping the resident maintain a sense of mastery and control in the nursing home environment.
Activities of Daily Living↗
Hyperpnoea and CO2 sensitivity of the respiratory centres during exercise.
The aim of this study was to specify whether exercise hyperpnoea was related to the CO2 sensitivity of the respiratory centres measured during steady-state exercise of mild intensity. Thus, ventilation (VE), breathing pattern [tidal volume (VT), respiratory frequency (f), inspiratory time (TI), total time of the respiratory cycle (TTOT), VT/TI, TI/TTOT] and CO2 sensitivity of the respiratory centres determined by the rebreathing method were measured at rest (SCO2re) and during steady-state exercise (SCO2ex) of mild intensity [CO2 output (VCO2) = 20 ml.kg-1.min-1] in 11 sedentary male subjects (aged 20-34 years). The results showed that SCO2re and SCO2ex were not significantly different. During exercise, there was no correlation between VE and SCO2ex and, for the same VCO2, all subjects had very close VE values normalized for body mass (bm), regardless of their SCO2ex (VEbm0.75 = 1.44 l.min-1.kg-1 SD 0.10). A highly significant positive correlation between SCO2ex and VT (normalised for bm) (r = 0.80, P less than 0.01), TI (r = 0.77, P less than 0.01) and TTOT (r = 0.77, P less than 0.01) existed, as well as a highly significant negative correlation between SCO2ex and (normalised for bm-0.25) (r = -0.73, P less than 0.01). We conclude that the hyperpnoea during steady-state exercise of mild intensity is not related to the SCO2ex. The relationship between breathing pattern and SCO2ex suggests that the breathing pattern could influence the determination of the SCO2ex. This finding needs further investigation.
Adult↗
A BASIC software program to estimate cardiac output and alveolar ventilation.
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.
Carbon Dioxide↗
Differences in aerobic and anthropometric characteristics between peripubertal swimmers and non-swimmers.
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.
Adolescent↗
Cloning of SHV-2, OHIO-1, and OXA-6 beta-lactamases and cloning and sequencing of SHV-1 beta-lactamase.
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.
Base Sequence↗
Structural and functional characterization of tnpI, a recombinase locus in Tn21 and related beta-lactamase transposons.
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.
Amino Acid Sequence↗
[Prognostic and therapeutic aspects of lympho-epithelial lesions of the parotid. Apropos of 8 cases].
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.
Adult↗
[Force-velocity test: effect of a heavy-load start on maximal anaerobic power and blood lactate levels].
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.
Adult↗