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Biomedical subjects

M Chaussain

Publications and source records attributed to M Chaussain.

49 records · Page 3Linked to original sources

Inhaled terbutaline administered via a spacer fully prevents exercise-induced asthma in young asthmatic subjects: a double-blind, randomized, placebo-controlled study.

The effects of inhaled terbutaline, a beta 2-adrenergic agonist, administered via a 750-ml spacer device were studied in young asthmatic subjects with exercise-induced asthma. A double-blind, randomized, placebo-controlled study of the effects of inhaled 0.5 mg terbutaline and placebo was conducted in 10 asthmatic children (age range 6-16 years) with documented exercise-induced asthma. Forced expiratory volume in 1 s (FEV1) was measured at baseline, 15 min after inhaling terbutaline or placebo, and at intervals up to 60 min after exercising. Subjects exercised using a cycle ergometer for 5 min at a submaximal, constant work-load while breathing dry air at room temperature. Terbutaline induced bronchodilation at rest in all subject and fully prevented exercise-induced asthma in nine out of the 10 subjects; the exercise-induced fall in FEV1 was markedly reduced in the remaining subject. It is concluded that exercise-induced asthma can be inhibited by pretreatment with inhaled terbutaline, administered via a spacer, in a majority of young asthmatics.

Administration, Inhalation↗

A sampling method for mean alveolar gas in normal subjects and patients with respiratory disease.

The paper describes an alveolar gas sampling method based on the criterion of equality of mean alveolar (RA) and expired (RE) respiratory quotients. Expired gas is sampled at an expired volume equal to VT/2 + VD by means of a mechanical sampler controlled by an analog computer. Eleven normal subjects and 50 patients with cardiopulmonary disease have been tested. When the difference between mean alveolar and expired respiratory quotients did not exceed 0.05, the result was considered to be satisfactory. Such results have been obtained in 40 patients and all of the normal subjects. For the remaining 10 patients, either experimental error and/or particular non-homogeneities in ventilation seemed to be the cause of the unsatisfactory results. Arterial to alveolar PCO2 differences have been calculated. The mean difference in normal subjects was never negative (1.86 +/- 1.58 torr).

Analysis of Variance↗

[Routine bedside measurement of arterio-alveolar CO2 difference (author's transl)].

Deficiencies in pulmonary circulation can economically be demonstrated at the patient's bedside by measuring the difference in CO2 between arterial blood and alveolar air, which reflects the air flow in non-perfused ventilated lung areas. The method does not inform on the cause of the deficiency, but normal values (i.e. lower than 10 %) indicate that pulmonary circulation is unimpaired, whereas high values suggest that it is reduced (emboli, capillary obstruction by leukocytes). That the method is valid is shown by the parallelism observed between the percentage air flow in non-perfused ventilated areas and the angiographic and anatomical findings.

Acute Disease↗

Lung transfer factor for CO at rest in normal children by a steady-state method.

Lung transfer for CO (TLCO) was measured at rest in 94 normal children (47 boys and 47 girls) whose ages ranged from 3.5 to 16 years. A steady-state method, using a technique of alveolar sampling based on the equality of the mean expiratory and alveolar respiratory quotients, was employed. Highly significant correlations, statistically different for boys and girls, were fond between TLCO and standing height. TLCO was also linearly correlated with the functional residual capacity--the only pulmonary volume measurable in very young children--but without any sex difference. A multiple linear regression relates TLCO to FRC and height. Variance analysis shows the preponderant influence of FRC.

Adolescent↗

[Exercise intolerance caused by muscular phosphorylase kinase deficiency. Contribution of in vivo metabolic studies].

A 33 year old man has been presenting since childhood an exertional muscle pain syndrome without myoglobinuria. Muscle biopsy revealed a vacuolar myopathy with glycogen excess in subsarcolemmal and intermyofibrillar spaces which was confirmed by electron microscopy. Plasma production of ammonia was abnormally high during exercise on a bicycle ergometer while the raise of lactate was normal. NMR spectroscopy showed an increased muscle glycogen content, with a slight and delayed drop of the pH during exercise. Phosphorylase b kinase activity was undetectable in muscle specimen whereas activities of others enzymes of carbohydrate metabolism were normal. Clinical presentation of our patient is compared to that of the reported cases of phosphorylase b kinase deficiency.

Adult↗

[Respiratory function at rest in obese children (author's transl)].

Abnormalities of the respiratory function are a common finding in adult obesity. In order to investigate the occurrence of similar facts in pediatric age, a group of 39 obese children (20 girls and 19 boys, aged from 7 to 15 years) whose weight excess for their height ranged from 25 to 105 p. 100 was studied and compared to a control group of normal children of similar ages. Lung volumes, blood gases, transfer factor of the lung for CO, dynamic lung compliance, total lung resistance and ventilatory response to CO2 have been studied. In these obese children by contrast to obese adults, the vital capacity and the residual volume were normal. The blood gases, the transfer factor for CO, the dynamic lung compliance and the total resistances of the lung were similar to those of the normal group. The respiratory patterns were normal in all children but one who had during a short time a periodic ventilation with short periods of breath-holding. The ventilatory response to CO2 of the obese children was decreased and a highly significant correlation was found between the individual values of the respiratory response to CO2 and the percentage of weight excess. Different hypotheses are discussed to explain these results.

Adolescent↗