Search PubMed⌕ Search

Biomedical subjects

C Gaultier

Publications and source records attributed to C Gaultier.

At least 145 records · Page 8Linked to original sources
PubMed1988

Circadian rhythm in total pulmonary resistance of asthmatic children. Effects of a beta-agonist agent.

Six children (boys and girls, 8 to 13 years old) with allergic asthma (AA) had their total pulmonary resistance (R1) measured at four fixed times (0730, 1130, 1630 and 2230 hr), before and again 10 min after a 2 mg orciprenaline (beta-agonist) aerosol inhalation. R1 was measured by means of the esophageal balloon technique. Subjects were socially synchronized in May with a diurnal activity from 0700 to 2100 and a nocturnal rest. Patients had had no asthma attacks and had received no medication for 8-15 days. Time series were analyzed according to conventional (t-tested mean time point differences) ANOVA, and cosinor methods. The 24 hr adjusted means (cm H2O.l/s +/- SEM) were 5.7 +- 0.4 in seven previously documented healthy children. 7.4 +/- 1.2 in AA before orciprenaline, and 4.9 +/- 0.2 in healthy children, 5.2 +/- 0.8 in AA after beta-agonist inhalation. Circadian rhythms were detected in both groups before but not after treatment. The treatment had its maximal effect on R1 around 0730 (when bronchial patency is close to its trough) and had no effect around 1630 (peak time of airway patency) in both groups (P less than 0.01; ANOVA). Thus, inhaled orciprenaline was mainly effective around 0730 and to a lesser extent around 2230 whereas there was no detectable effect during the day (1230 and 1630).

Administration, Inhalation↗
PubMed1988

[Physiology and physiopathology in the development and maturation of the antenatal lung].

The term "pulmonary maturation" is reserved for the process of surfactant production. The term "pulmonary development" covers the overall phenomena of the growth of pulmonary structures and their differentiation. Pulmonary development is divided schematically into five stages: the embryonic stage up to the fifth to the seventh week of gestation, then the four stages of the foetal period. These four stages are: 1) The pseudo-glandular stage up to the seventeenth week during which the bronchi and the extra-acinar vessels are formed; 2) The canalicular stage characterised by the birth of the acinus, the differentiation of the cells and the beginning of surfactant synthesis to the end of this stage; 3) The saccular and alveolar stages. The saccular stage begins between the 24th and 26th week of gestation and at this stage the foetus is viable but exposed to the risk of neonatal respiratory distress on account of lack of surfactant. The alveoli are formed before the end of pregnancy. The factors controlling development and pulmonary maturation are still poorly understood. Cellular, particularly epithelial and mesenchymal interactions appear to play a major role in all the stages of development. Hormonal interactions play a determining role in pulmonary maturation. The effects on development and/or pulmonary maturation of pharmacological agents, hormones administered to the mother (e.g. opiates, glucocorticoids, aminophylline, beta-sympathomimetics, indomethacin and tobacco...) and maternal pathology are described as far as possible within the limits of our current knowledge. This information comes above all from experimental studies, thus the conclusions obtained are difficult to apply to newborn humans.

Cell Differentiation↗
PubMed1988

[Comparison of arterial and transcutaneous oxygen partial pressure in infants with bronchopulmonary dysplasia].

Transcutaneous PO2 (PTCO2) (Radiometer electrode heated to 44 degrees C) was compared to arterial PO2 (PaO2) in 19 infants with bronchopulmonary dysplasia: 12 infants were tested once, at the mean postnatal age of 14 weeks (range 4-43 weeks), the other 7 infants were studied longitudinally from 5 weeks (range 2-8 weeks) to 12 weeks (range 6-18 weeks) of postnatal age. The protocol was standardized: measurement during behavioral stage 1, using a peripheral arterial line. Twenty-eight comparisons between PTCO2 and PaO2 were obtained. PTCO2 was significantly related to PaO2 [PTCO2 (mmHg) = 0.81 PaO2 + 5.2, r = 0.73, p less than 0.01]. The mean difference PTCO2 - PaO2 was -7.2 mmHg (range: -34.5 to + 33); in the studied age range the PTCO2 - PaO2 was not significantly related to postnatal age (r = -0.24; p greater than 0.1).

Blood Gas Monitoring, Transcutaneous↗
PubMed1987

Use of total inspiratory pressure-volume curves for determination of appropriate positive end-expiratory pressure in newborns with hyaline membrane disease.

Thirty newborns with hyaline membrane disease were treated by mechanical ventilation with individualized appropriate positive end-expiratory pressure (APEEP) from inspiratory pressure-volume curves of the total respiratory system. APEEP was started before H24 in group 1 (19 patients), and after H24 in group 2 (11 patients). Until APEEP, the 2 groups had classical PEEP levels (lower than 0.8 kPa) either without or with incomplete improvement in arterial hypoxia. The mean APEEP of each group was greater than classical PEEP (p less than 0.001). In group 1 the time of exposure to FiO2 greater than 0.4 was shorter (23.8 +/- 13.7 h) than in group 2 (88.6 +/- 56.9 h) (p less than 0.001) and rapid improvement in blood gas exchanges was seen in group 1 compared to group 2 that was independent of the severity of the disease. Tolerance was excellent. APEEP ventilation started before H24 is of special interest in the management of newborns with severe alveolar injury.

Hemodynamics↗
PubMed1987

Circadian rhythm of serum total immunoglobin E (IgE) in asthmatic children.

Time of day related changes in serum total IgE (and cortisol as marker rhythm) were documented in 6 non-allergic children (2 girls, 4 boys, 6 to 10 years old) and 3 boys (10 to 14 years) with allergic asthma but symptom free at the time of the study. Subjects were synchronized with a diurnal activity from 07.00 to 21.00 and a nocturnal rest. Venous blood was sampled at fixed times (07.30, 11.30, 16.30 and 22.30) during a 24 hours span for the healthy children and during a 48 hours span for the asthmatics. Radioimmunoassay methods were used for the determinations. Time series were analyzed according to conventional (t tested differences, ANOVA) and Cosinor methods. No IgE circadian rhythm was validated in healthy children while a large amplitude (approximately equal to 30% of the 24 hours mean) circadian rhythm with 2 diurnal peaks and a nocturnal trough was demonstrated (P less than 0.0023) in the asthmatics. Therefore, time qualified references are needed for the interpretation of total IgE as they are for many biological variables. Circadian rhythm of IgE is presumably related to those of lymphocyte subpopulations such as B, T and T-suppressor cells.

Adolescent↗
PubMed1987

Paradoxical inward rib cage motion during rapid eye movement sleep in infants and young children.

In neonates, rib cage motion on inspiration during rapid eye movement sleep is almost exclusively paradoxical. We wondered whether or not duration of paradoxical inward rib cage motion on inspiration during rapid eye movement sleep decreases in infancy and early childhood. Thirteen healthy infants from 7 to 31 months of age were tested during natural afternoon naps. Electroencephalogram, electrooculogram and electromyogram were all recorded. Airflow was measured by nasal and buccal thermistors, abdominal and rib cage anteroposterior diameters by magnetometers. Transcutaneous partial pressure of O2 was monitored. Diaphragmatic electromyographic activity was recorded using surface electrodes. The average total sleep time was 138 min ranging from 107 to 186 and rapid eye movement sleep time amounted to 15% of total sleep time ranging from 6 to 25. During rapid eye movement sleep, the total duration of paradoxical inward rib cage motion was measured and expressed as a percentage of rapid eye movement sleep time. We found that duration of paradoxical inward rib cage motion during rapid eye movement sleep decreased significantly with age (r = -0.66, P less than 0.02) which may be explained by the changes in chest wall compliance and geometry of the rib cage occurring with growth. We observed no decrease in transcutaneous partial pressure in O2 during paradoxical inward rib cage motion during rapid eye movement sleep in infants in contrast to that reported in neonates.

Aging↗
PubMed1986

Maximal static pressures and lung volumes in young female swimmers.

The postulate that lung volumes are increased in swimmers because of a training effect that increases maximal static pressures (Pmax) thus augmenting the ability to inflate and deflate the lung was examined by comparing 38 competitively trained female swimmers to 59 controls between 7 and 13 years of age. Maximal static pressures on inspiration and expiration were generated near residual volume (RV), at functional residual capacity (FRC) and near total lung capacity (TLC). Lung volumes were measured by body plethysmography. The expected increase in lung volumes was present in the swimmers and was most marked in the oldest subjects. However, training did not have the anticipated effect on Pmax. In the younger swimmers training was associated with an increase in Pmax, but in the older swimmers Pmax was actually decreased in comparison to controls. These findings suggest that training may directly enhance lung growth, since the changes in lung volume cannot be accounted for by increases in respiratory muscle strength.

Child↗
PubMed1986

Resting lung function in children after repair of tetralogy of Fallot.

Children with tetralogy of Fallot had pulmonary function tests (PFT) after intracardiac repair (ICR). According to the age at time of ICR and to the existence or not of palliative surgery preceding ICR, they were divided into three groups. Group 1 had ICR at a mean of one year one month of age (range four months to one year seven months), that is, during the active period of postnatal lung growth. Groups 2 and 3 had ICR later in childhood, that is, respectively, at four years seven months (range two years nine months to 11 years 9 months) and at five years four months (range two years seven months to 11 years five months). In group 3, ICR was preceded by palliative surgery. The PFT at rest included measurement of lung volumes (functional residual capacity), vital capacity (VC), dynamic or static compliance (CL), total pulmonary resistance, lung transfer factor for CO (TLCO) and blood gases. Group 1 had normal lung function suggesting that early repair of TOF saves lung development. In groups 2 and 3, significant decrease in VC(p less than 0.01) and CL (p less than 0.01) were found suggesting impaired alveolar growth. Additional defect in TLCO (p less than 0.01) in group 3 suggested that palliative surgery induces abnormal vascular growth. Thus, the present functional results suggest repair of TOF during the two first years of life, ie, the active period of postnatal lung growth.

Adolescent↗
PubMed1986

Lung mechanics in growing guinea-pigs treated with growth hormone.

Because growth hormone excess has been reported to accelerate lung growth in acromegalic men and in adult rats, effects of growth hormone were tested in prepuberal guinea-pigs. From week 2 to week 4, five guinea-pigs were injected daily with human growth hormone (0.1 mg/kg) and compared with five injected with saline. At week 4 lung mechanices were measured and the animals sacrificed. Growth hormone-injected guinea-pigs gained more weight than saline ones (P less than 0.01) and had heavier livers (P less than 0.01). However, no difference was observed between both groups for lung weight, volume or distensibility.

Animals↗
PubMed1985

Inspiratory force reserve of the respiratory muscles in children with chronic obstructive pulmonary disease.

The purpose of this study was to evaluate inspiratory muscle force reserve in children with chronic obstructive pulmonary disease (COPD). In 15 hyperinflated (FRC/TLC, 65 +/- 0.7%) children, maximal mouth inspiratory static pressure (PImax) at FRC, mouth occlusion pressure (P0.1), tidal volume (VT), inspiratory time (TI), and total duration of the respiratory cycle (Ttot) were all measured. It was found that PImax at FRC was reduced compared with predicted values. However, after lung volume correction, PImax was in the normal range, and P0.1 was higher, TI was shorter, and Ti/Ttot was lower than predicted. The estimated mean inspiratory pressure for breathing at rest (PI) was significantly higher than predicted and was related to total pulmonary resistance (r = 0.74, p less than 0.001). The fraction of PImax developed by the respiratory muscles for breathing at rest (PI/PImax) significantly increased. The higher the PI/PImax ratio, the more the TI/Ttot ratio decreased (r = -0.64, p = 0.01). At rest, our subjects had to develop a mean inspiratory power (W) of as much as 48% (range, 30 to 76%) of the critical W above which fatigue occurs. Thus, even minimal increases in breathing load might expose children with COPD to respiratory muscle fatigue and to respiratory failure.

Adolescent↗
PubMed1985

Respiration during sleep in children with COPD.

Seventeen children (mean age, nine years) with chronic obstructive pulmonary disease (COPD) were studied during sleep. Electroencephalography, electrooculography, and electromyography were all recorded. Airflow was measured by nasal and oral thermistors, and abdominal and thoracic anteroposterior diameters by magnetometers. Transcutaneous partial pressure of O2 (tcPO2) and of CO2 (tcPCO2) were monitored. The average total sleep time was 283 min +/- 36 (1 SD). Breathing pauses (BP) five seconds or longer were measured. The mean time of BP expressed as a percentage of TST was 1.3 percent +/- 0.8 (1 SD). The BP occurred most frequently during REM sleep. Forty-six percent of BP were obstructive (OBP). The percentage of OBP was significantly related to the degree of lung resistance during wakefulness. Periodic breathing was observed with a mean frequency of 2.2 times per night (range: 0 to 7). Episodes with paradoxic inward rib cage motion were seen one to 29 times (mean 6.6). Drops in tcPCO2 greater than 5 mm Hg occurred one to eight times and 67 percent were observed during REM sleep. Compared to tcPCO2 during W the mean maximal decrease in tcPCO2 was 14 mm Hg (range 8 to 29). tcPCO2 rose with a mean maximal of 9.1 mm Hg (range 6 to 13). It was concluded that children with COPD had worsened gas exchange during sleep.

Child, Preschool↗
PubMed1985

[Respiratory function during wakefulness and sleep in a 7-year-old child with congenital alveolar hypoventilation of central origin].

Pulmonary function tests were performed in a 7 year-old girl with central alveolar hypoventilation syndrome treated with mechanical ventilation during sleep. Results showed: 1. during wakefulness decrease in residual functional capacity, in dynamic lung compliance and in lung transfer factor for CO; 2. during sleep the characteristics of the syndrome as reported in the neonatal period i.e. central alveolar hypoventilation in stages 2 and 3-4 which justified maintenance of mechanical ventilation when asleep.

Child↗
PubMed1984

Lung mechanics in growing guinea pigs.

Lung mechanics were studied in four groups of guinea pigs: neonatal (1), prepubertal (II), postpubertal (III) and adult (IV). The animals were anesthetized and tracheotomized, and an esophageal catheter was inserted. Functional residual capacity (FRC) was measured by body plethysmography. After curarization, the lungs were inflated to a transpulmonary pressure of 30 cm H2O. The resulting change in volume was added to FRC to obtain the total lung capacity (TLC). Lung compliance (CL) normalized for dry lung weight (CL/LW) was calculated. An exponential function was fitted to the experimental P-V curve and the shape constant k was considered as an index of lung distensibility. During growth TCL (ml) increased with BW (g): TLC = 0.3 BW0.69 (r = 0.96). Two significantly different equations (P less than 0.001) were found between TLC (ml) and LW (g): between I and II, TLC = 32.4 LW1.24 (r = 0.88) and between III and IV, TLC = 22.9 LW0.53 (r = 0.73). An increase in lung distensibility as reflected by a significant increase in both CL/LW and the shape constant k was observed. In neonates and in prepubertal animals CL/LW was equal to 1.53 +/- 0.64 and to 2.38 +/- 0.51 ml/cm H2O/g (mean +/- 1 SD), respectively (P less than 0.01) and k to 0.146 +/- 0.026 and 0.219 +/- 0.035 cm H2O-1 (P less than 0.001). From prepuberty to adulthood no further significant changes were observed. These results showed that even in a species with an advanced maturation at birth, lung mechanics changed with growth.

Aging↗