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Biomedical subjects

A Shida

Publications and source records attributed to A Shida.

At least 37 records · Page 2Linked to original sources
PubMed1982

[Evaluation of pulmonary function parameters in twins].

The purpose of this study was to determine the role of genetic influence on the variability of pulmonary function tests in normal individuals. Thirty-one pairs of twins (20 monozygotes (MZ) and 11 dizygotes (DZ) of both sexes, ranging in age from 15 to 18 years, were tested. Degree of similarity in each parameter was compared between MZ pairs and DZ pairs by within-pair variance ratio (MWDZ/MWMZ). The within-pair variances of MZ were smaller than DZ with respect to FVC, FEV1/FVC, V50, V25, delta N2 and FRC. These parameters were corrected for height; again the within-pair variances of MZ were smaller than DZ with respect to all the parameters except for FRC. The results indicate that these parameters were at least partly determined by genetic factor. However the within-pair variance of FEV1, PF, CV/VC, Raw, Pao2, Paco2, pH, and [HCO3-] were not different between the two groups. To estimate the similarity within MZ pairs, among-pair to within-pair variance ratio (MAMZ/MWMZ) were used. All the parameters of pulmonary mechanics showed similarity within pairs. Arterial pH and Pao2 also disclosed a significant similarity within-pairs, but Paco2 and [HCO3-] did not.

Adolescent↗
PubMed1981

Relationship between hypoxic and hypercapnic ventilatory responses in man.

Ventilatory responses to hypoxia (A) and hypercapnia (S) were measured in 127 healthy men (105 males and 22 females) by a dual control system for regulating Pa O2 and Pa CO2 simultaneously and independently of each other. The subjects were classified into groups according to sex, age, family history, and genetics (twins). Mean values for A were 138 +/- SD 93 liters/min.mmHg in group I (subjects without family history of chronic lung diseases) and 80 +/- 56 liters/min.mmHg in group II (sons of patients with chronic obstructive pulmonary disease or silicosis). The difference was highly significant (P less than 0.001). Mean S were 1.11 +/- 0.39 liters/min.mmHg-1 in group I and 1.16 +/- 0.48 liters/min.mmHg-1 in group H. The difference was not significant. Mean values for A and S in the aged males (mean age = 71.3 years) did not differ from those in 15 adult males (mean age = 29.5 years) and 60 young twins (mean age = 16.4 years). In every respect of age, sex, familial factors, and genetics, A and S were not interrelated. Mouth occlusion pressure (P0.1) was measured during air breathing and it correlated neither with A nor S. These results indicate 1) hypoxic and hypercapnic responses are not strongly related to each other, and 2) the aging process does not alter ventilatory responses to hypoxia and hypercapnia.

Adolescent↗
PubMed1981

Familial aggregation of abnormal ventilatory control and pulmonary function in chronic obstructive pulmonary disease.

A sex-, age-, obesity, and protease inhibitor-matched study of pulmonary function and ventilatory control was performed on 26 sons of 19 patients with chronic obstructive pulmonary disease (COPD) and 26 control subjects. Mean values for FEV1/FVC and V25 were significantly lower and CV/VC was significantly higher in sons of patients than in the controls. VC, airway resistance, static pulmonary compliance. delta N2, arterial blood gases and pH were not different between sons and controls. When the sons of patients were divided into two groups according to the arterial blood gases of their parents, sons of hypoxemic, hypercapnic parents showed significantly lower hypoxic ventilatory responses than sons of normoxemic, normocapnic parents. Hypercapnic ventilatory responses were not different between sons and controls. Abnormal pulmonary function and low ventilatory responses were more frequently detected in sons than in controls. The association of smoking with abnormalities of pulmonary function was not clearly seen in sons. These results suggest that familial factors (either genetic or environmental) play a significant role in determining the pathogenesis and clinical types of COPD.

Adult↗
PubMed1980

The effects of posture on capillary blood flow pulse and gas exchange in the lungs of man.

Cardiac output and pulmonary capillary blood flow were measured on 5 normal subjects to dye dilution and N2O-body plethysmograph method, respectively. To facilitate calculations and to improve signal to noise ratio, a computer of average transient was used. Cardiac output increased from 7.16 +/- SEM 0.86 L/min to 8.46 +/- 0.72 L/min after the subject changed his posture from upright to supine. Pulmonary capillary blood flow also increased from 5.2 +4- 0.44 L/min to 6.95 +/- 0.48 L/min. These changes were mostly due to changes in stroke volume. The differences between cardiac output and pulmonary capillary blood flow were 19% and 15% in upright and supine positions, respectively. Conduction time of blood flow pulse from pulmonic valve to pulmonary capillary beds prolonged significantly in supine position. Flow acceleration and pulsatility index did not change by posture. Changes in flow acceleration and changes in PaO2 were significantly correlated. These results indicate: 1) profiles of pulmonary capillary blood flow pulse do not alter by posture except conduction time, 2) zone I which is normally closed because of gravity in upright position seems to recruit in supine position, and 3) blood flow acceleration is responsible at least partially for postural changes in PaO2.

Adult↗