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Biomedical subjects

T Isawa

Publications and source records attributed to T Isawa.

At least 55 records · Page 3Linked to original sources
PubMed1986

Mucociliary clearance mechanism in interstitial lung disease.

To evaluate mucociliary clearance mechanisms of the lungs, 14 patients with pulmonary interstitial fibrosis and 8 with sarcoidosis were studied by lung function tests and radioaerosol inhalation lung cine-scintigraphy. Although all these patients showed interstitial densities on chest x-rays, only the patients with pulmonary interstitial fibrosis indicated restrictive and diffusion abnormalities by lung function tests and those with sarcoidosis did not show either of these functional abnormalities. Mucociliary clearance mechanisms were well maintained qualitatively and quantitatively in these patients with interstitial lung disease.

Aerosols↗
PubMed1986

Effect of oral salbutamol on mucociliary clearance mechanisms in the lungs.

The purpose of the study was to investigate whether or not orally administered salbutamol would affect mucociliary clearance function in the lungs. Salbutamol, 4 mg, was given orally 3 times a day for 7 days to 10 and 9 patients with various chest diseases in stable stage, respectively; the former were also currently taking other medications and the latter, none. Lung function tests, chest x-rays and radioaerosol inhalation lung cine-scintigraphy were performed before and after the administration of salbutamol. There was little qualitative or quantitative difference in mucociliary clearance function in either group before and after the administration of oral salbutamol, although it induced some increases in VC and FEV1.0 and a decrease in RV/TLC ratio in the former and some increases in FEV1.0, FEV1.0% and MMF in the latter. Oral salbutamol seems little to affect the mucociliary clearance function in the lungs.

Adult↗
PubMed1986

Activities of cefoxitin in vitro and in vivo: a study in patients with biliary tract infection undergoing percutaneous transhepatic biliary drainage.

Activities of cefoxitin and the effect on killing of bacteria in bile from six patients undergoing percutaneous transhepatic biliary drainage were analyzed in relation to in vitro activities of the drug, with particular reference to the incubation time. The bacteriostatic and bactericidal activities of cefoxitin with short term (6 hr) incubation correlated well with the duration of the effective cefoxitin concentration and the decrease of viable bacteria in bile juice from the patients. These timed in vitro activities can be used as well as the conventional MIC and MBC with the prolonged incubation of 24 hr, in the deductive analysis of bacterial response in vivo.

Aged↗
PubMed1985

Estimation of alveolar deposition ratio of inhaled radioaerosol.

The lung retention ratio (LRR) and the alveolar deposition ratio (ALDR) are mandatory to calculate the other three indices for quantitatively evaluating mucociliary clearance function of the ciliated airways; the airway deposition ratio (ADR), the airway retention ratio (ARR) and the airway clearance efficiency (ACE). According to our original method, the LRR required 2-hr continuous measurement of radioactivity in the thorax and the ALDR a repeat measurement at 24-hr after radioaerosol inhalation. The 2-hr continuous measurement is, however, too long for a clinical examination and the 24-hr repeat measurement cumbersome. The purpose of the study was to find a way to get the ALDR by calculation without repeating the 24-hr measurement and by counting radioactivity for the shortest possible period and yet without sacrificing the visual evaluation by compiling radioaerosol inhalation lung cine-scintigraphy. By using the derived formulae listed in Table 1, the ALDR was calculable. Forced expiratory volume (FEV) in one sec divided by FEV in per cent (FEV1.0%), the initial 60 min measurement of radioactivity without repeating 24-hr measurement, and smoking history were the minimum requirements to calculate the ALDR. The calculated ALDR appeared reliable enough to estimate the other indices.

Aerosols↗
PubMed1984

Mucociliary clearance mechanism in smoking and nonsmoking normal subjects.

Mucociliary clearance mechanisms were evaluated in 17 normal subjects visually and qualitatively by radioaerosol inhalation cinescintigraphy of the lung, and quantitatively by calculating the following indices: (a) overall or regional lung retention ratio; (b) airway deposition ratio; (c) airway retention ratio; (d) airway clearance efficiency; and (e) alveolar deposition ratio. The inhaled aerosol deposited homogeneously throughout the lungs, and mucus transport was always cephalad in direction and constant in velocity, although a temporary stasis of mucus was seen in smokers. Overall lung retention ratio was significantly smaller and airway deposition ratio was significantly larger in the smokers than in nonsmokers, but there was no difference between the groups in airway retention ratio or airway clearance efficiency. There was an inverse relationship between alveolar deposition ratio and cigarette consumption. Mucociliary clearance mechanisms were well maintained in the normal subjects, but in the smokers inhaled aerosol tended to deposit more proximally.

Adult↗
PubMed1984

Lung clearance mechanisms in obstructive airways disease.

Using radioaerosol inhalation lung cinescintigraphy, pulmonary clearance mechanisms were studied in 21 patients with obstructive airways disease. In none of them did we find homogeneous deposition of inhaled radioaerosol in the lungs, or a steady, constant, axial, and cephalad transport of radioactivity in the major airways. Of the 21 patients, 14 showed temporary but frequent stopping and starting of radioactivity in the airways in the course of lung clearance; in ten there was reversal of flow; in five migration of radioactivity from one bronchus into the opposite, bypassing the trachea and often followed by shuttling between right and left bronchi; and in four there was spiral or zigzag transport of radioactivity. The overall lung retention ratio in the first 2 hr was not abnormal, but the airway deposition ratio was significantly above normal, and airway clearance efficiency was below. The alveolar deposition ratio was also significantly smaller in these patients.

Adult↗
PubMed1981

Radioaerosol inhalation lung cine-scintigraphy: a preliminary report.

"Radioaerosol inhalation lung cine-scintigraphy", a cinematographic display of the lungs following radioaerosol inhalation has been found to be extremely helpful not only to the visual assessment of mucociliary clearance in the lungs but also to the setting of regions of interest and to the interpretation and analysis of clearance curves over the regions of interest in the lungs. It is expected that this procedure offers an important means to the study of mucociliary clearance in health and disease in man.

Adult↗
PubMed1981

Effect of isoproterenol on regional pulmonary perfusion and its blockade by propranolol.

Effects of isoproterenol and propranolol on regional pulmonary perfusion were assessed in the dog. In each experiment the right upper lobe was isolated in vivo by a balloon catheter and artificially ventilated with nitrogen, air or 60% oxygen in nitrogen before and after administration of the medicaments listed above. The rest of the lungs kept breathing air spontaneously. Following administration of isoproterenol regional pulmonary perfusion increased in the hypoxic right upper lobe induced by artificial ventilation with nitrogen, but the increase was not observed when isoproterenol was administered following pretreatment with propranolol. Administration of propranolol alone did not induce any change in regional pulmonary perfusion distribution. When artificial ventilation was done in the right upper lobe either with air or 60% oxygen in nitrogen, thus inducing regional less hypoxia or hyperoxia, no change in regional perfusion was observed with any of the medication. Thus isoproterenol reversed regional hypoxic pulmonary vasoconstriction, but its action was blocked by pretreatment with propranolol. Propranolol per se, however, showed no effect on pulmonary vascular responses to the different alveolar oxygen tensions.

Animals↗
PubMed1981

Effect of dopamine on regional pulmonary perfusion.

Dopamine effect on regional pulmonary perfusion in the right upper lobe was studied in 6 dogs in which the lobe was isolated by a balloon catheter and artificially ventilated with nitrogen, air or 60% oxygen in nitrogen, while the rest of the lungs was allowed spontaneous air respiration. Dopamine was administered at the rate of 20 micrograms/kg/min. Each dog served as its own control. There was no change in the regional vascular responses to the different alveolar oxygen tensions in the right upper lobe before and after dopamine administration.

Animals↗