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Biomedical subjects

R Begin

Publications and source records attributed to R Begin.

7 recordsLinked to original sources
PubMed1979

Regulation of respiration in Friedreich's ataxia.

Friedreich's Ataxia (F.A.) is a degenerative disease which commonly leads to premature death of cardiorespiratory origin. To explain the early death of these patients, previous investigations have established the existence of 1) a cardiomyopathy in nearly 100% of cases, 2) a restrictive pulmonary syndrome of scoliotic origin and 3) a mild hypoxemia associated with slight respiratory alkalosis and a normal oxyhemoglobin dissociation curve. To further assess the cause of early death in patients with such neuromyopathy, we evaluated, in eleven F.A. patients, the sensitivity of the respiratory centers to hypercapnia, hypoxia, and hyperoxia. Ventilatory (VE, VT, F, VT/Ti) and occlusion pressure (P0.1) responses were taken as indices of the respiratory centers output during progressive hypercapnia (Read's method) and isocarbic hypoxia (Weil's method). We studied 11 Friedreich's Ataxia patients and 11 age, sex, and armspan matched controls. The responses of patients to hypercapnia were significantly greater than controls but their responses to hypoxia were similar to controls. Our study establishes that the respiratory centers are functioning adequately in early Friedreich's Ataxia and do not contribute to cardio-respiratory insufficiency in such neuromyopathy.

Adolescent↗
PubMed1979

Farmer's lung in early childhood.

A 5-year-old child with classic farmer's lung disease is reported. The disease started after a flulike episode and progressed during 3 months to severe respiratory failure. The clinical features were fatigability, weight loss, recurrent fever, dry cough, pulmonary rales, and clubbing. Serologic studies for precipitins to Micropolyspora faeni were positive. The chest roentgenogram showed a ground-glass appearance with air bronchogram. The open lung biopsy material was typical for alveolitis, with minute interstitial granulomas and obliteration of lung parenchyma. The child's condition improved rapidly with prednisone therapy and avoidance of the allergen.

Child, Preschool↗
PubMed1978

Oxygen transport in patients with Friedreich's ataxia.

The hypothesis is that an abnormal oxygen-hemoglobin dissociation curve is a primary or a secondary defect in patients with Friedreich's ataxia was investigated in 12 subjects with this disease. Hemoglobin and P50 were measured and compared with age and sex matched controls. The mean hemoglobin concentration was 14.2 g% and the P50 was 26.25 torr for the patients and 13.8 g% and 26.27 torr in the controls. These results indicate that the oxygen transport system is normal in this disease and likely exclude an abnormal oxygen dissociation curve as a primary or a secondary factor in the pathophysiology of the cardiomyopathy and the neuromyopathy found in this disease.

Friedreich Ataxia↗
PubMed1975

Value of capillary blood gas analyses in the management of acute respiratory distress.

A comparative study of blood gases and acid-base parameters, obtained simultaneously from arterial and finger capillary samples, was performed in 45 patients in acute respiratory distress without circulatory shock. Although small and significant differences were found between the 2 sample pH, Po2, Pco2, and bicarbonate values, the correlations between the 2 were greater than or equal to 0.97 for each variable. It was concluded that although the arterial blood is the preferred sample for evaluation of blood gases and acid-base status of patients in acute respiratory distress, capillary blood appears to be a valid substitute in the management of these patients. This technique is particularly valuable in pediatric practice, where repeated arterial samples are less easily obtained.

Acute Disease↗
PubMedDate not supplied

Regional lung expansion and vertical pleural pressure gradients in normal human subjects.

Using 133Xe and a single slow inspiration from near residual volume (RV) to total lung capacity (TLC), we measured regional lung volume continuously in six regions as a fraction of volume at maximal inflation in 57 normal non-smoking subjects (age: 20 to 82 years). We found that regional initial (i.e., near RV) volume/TLC increased significantly with aging in all regions for females whereas the increase in males was significant only in the upper regions. These results suggest that the aging process in the lung is accelerated in females. Some variability in regional volume measurements occurred when inspiration started from FRC rather than near RV. Although the patterns of regional expansion generally confirm those previously reported, it was found that the volume of vertically adjacent regions do frequently become equal and cross-over one another. Using the measurements of static compliance, regional V/TLC at FRC, and a passive model based upon an isotropic distribtion of intrinsic elasticity throughout the lung, the mean vertical pleural pressure gradient between upper and middle regions and middle and lower regions were estimated as 0.246 cmH2O/cm and 0.267 cmH2O/cm respectively. We believe that the regional expansion patterns which we observed can be explained by the interaction between a variable thoraco-diaphragm/abdominal motion and a passive elastic lung.

Adult↗