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Biomedical subjects

M Munakata

Publications and source records attributed to M Munakata.

At least 217 records · Page 12Linked to original sources
PubMed1986

Production mechanism of crackles in excised normal canine lungs.

Lung crackles may be produced by the opening of small airways or by the sudden expansion of alveoli. We studied the generation of crackles in excised canine lobes ventilated in an airtight box. Total airflow, transairway pressure (Pta), transpulmonary pressure (Ptp), and crackles were recorded simultaneously. Crackles were produced only during inflation and had high-peak frequencies (738 +/- 194 Hz, mean +/- SD). During inflation, crackles were produced from 111 +/- 83 ms (mean +/- SD) prior to the negative peak of Pta, presumably when small airways began to open. When end-expiratory Ptp was set constant between 15 and 20 cmH2O and end-expiratory Ptp was gradually reduced from 5 cmH2O to -15 or -20 cmH2O in a breath-by-breath manner, crackles were produced in the cycles in which end-expiratory Ptp fell below -1 to 1 cmH2O. This pressure was consistent with previously known airway closing pressures. When end-expiratory Ptp was set constant at -10 cmH2O and end inspiratory Ptp was gradually increased from -5 to 15 or 20 cmH2O, crackles were produced in inspiratory phase in which end-inspiratory Ptp exceeded 4-6 cmH2O. This pressure was consistent with previously known airway opening pressures. These results indicate that crackles in excised normal dog lungs are produced by opening of peripheral airways and are not generated by the sudden inflation of groups of alveoli.

Animals↗
PubMed1985

Phonopneumograph possible for real-time tracing.

We constructed a new phonopneumograph that provides real-time tracing of lung sounds at a high speed without the steps of memory and playback by use of a thermal printer system. Accuracy of the recorded wave form was considered adequate even at the maximum speed of 750 mm/sec for detailed wave form analysis. The device is easily connected to a recording system for respiratory flow rate or volume. To test the clinical usefulness of this portable instrument, the difference in the interpretation of four types of basic adventitious lung sounds by different listeners was examined. The "trained" group who had experience in using this instrument interpreted adventitious lung sounds more accurately than did the "untrained" group. Even in the "trained" group, however, the accuracy of identifying certain sounds was sometimes low. These results suggest that this device is useful for bedside interpretation of adventitious lung sounds or for training of auscultation ability.

Analog-Digital Conversion↗
PubMed1985

Rales in silicosis. A correlative study with physiological and radiological abnormalities.

Pulmonary auscultation, pulmonary function tests and radiological examination were done in 127 hospitalized patients with silicosis. Fine crackle (FC) was heard in 21.3% of patients, coarse crackle (CC) in 28.5%, rhonchi or wheeze (RorW) in 25.2% and friction rub (FR) in 5.5%. In complicated silicosis the incidence of rales was paradoxically lower than in simple silicosis (54.6 vs. 83.3%, respectively, p less than 0.05). In simple silicosis, patients with CC and/or RorW had lower %VC and FEV1/FVC%, but in complicated silicosis, the relation between the presence of rales and pulmonary functional status was not so apparent. These results suggest that in relatively advanced silicosis, all kinds of rales are heard, and in simple silicosis, rales are useful indicators of physiological impairment, but in complicated silicosis, they do not seem to be so useful.

Aged↗
PubMed1984

Gallium-67 scintigraphy, bronchoalveolar lavage, and pathologic changes in patients with pulmonary sarcoidosis.

The intensity of gallium-67 scintiscans, lymphocyte counts in bronchoalveolar lavage fluid, and pathologic changes were studied in 26 patients with untreated pulmonary sarcoidosis. Noncaseating granulomas were recognized with significantly greater frequency in stage 2 (80 percent; 8/10 cases) than in stage 1 (43 percent; 6/14 cases). Alveolitis showed little relation to the roentgenographic stage. There was a strong correlation between the intensity of gallium uptake in pulmonary parenchyma and the detection rate of granuloma; however, the detection rate of alveolitis was not statistically different from the intensity of gallium uptake. A highly significant correlation was revealed between the lymphocyte counts in bronchoalveolar lavage fluid and the intensity of alveolitis. These observations suggest that the gallium uptake reflects mainly the presence of granuloma, and the lymphocyte count in bronchoalveolar lavage fluid reflects the intensity of alveolitis in patients with pulmonary sarcoidosis.

Adolescent↗