Spectrophotometric assay with hippuryl-L-histidyl-L-leucine as a substrate to measure serum angiotensin-converting enzyme (S-ACE) activity was first reported by Lieberman in 1975, and is still a standard assay method for S-ACE.
But Lieberman's method has many difficulties which might influence the results of the assay. Therefore, we tried to re-examine each condition of the assay.
Major modifications to the original method were as follows:
1) Phosphate buffer used in the original method was not suitable for the assay and should be replaced by borate buffer. Optimal pH of the buffer NaCl-substrate solution was 8.3.
2) When borate buffer was used, a higher concentration of NaCl (0.4M as the final concentration of the assay system) was preferred to the original method (0.3M).
3) To avoid gel formation by the addition of HCl and ethyl acetate, the concentration of HCl was decreased to 0.5N (original 1.0N) and ethyl acetate should be added gently along the wall of the test tubes.
4) Conditions to evaporate ethyl acetate greatly influenced the result of the assay. Trace remainder of the solvent gave abnormally high values and too high temperature or too long heating resulted in low values. Optimal conditions should be determined for individual heating-devices by a preliminary experiment.
The above constitute our modified method for S-ACE.

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Six family members (wife, 3 sons and 2 daughters) of a patient with pulmonary emphysema and chronic bronchitis were studied for ventilatory response against hypoxia and hypercapnia, pulmonary functions and serum protease inhibitors.
Ventilatory response against hypoxia was abnormally low in 2 sons and 2 daughters. One son showed a low ventilatory response against hypercapnia. The pulmonary functions of the wife were abnormal in FFV₁/FVC, Raw, PaO₂, DLCO, CV/VC, ΔN₂, V₅₀, and V₂₅. Three sons and 1 daughter showed abnormal pulmonary functions. Serum protease inhibitors (a₁-antitrypsin, a₂-macroglobulin, C₁-inactivator, antithrombin III, and a₂-plasmin inhibitor) were within normal limits in all the family members.
These results suggest involvement of familial factors in ventilatory control and pulmonary function.

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The flow-volume curve adovocated by Hyatt in 1958, has been studied by obstructive changes of small airways in chronic obstructive lung disease. However, the evaluation of restrictive changes of the lung with the flow-volume curve has received little attention. We designed this study to evaluate restrictive changes of the lung in heart diseases with the flow-volume curve.
Flow-volume curves and compliance were measured in 12 normal subjects and in 53 patients with non-congenital heart diseases. The pulmonary hemodynamics of 20 subjects were examined during right cardiac catheterization as it seemed that restrictive lung changes due to pulmonary congestion existed in these patients.
There was a good correlation between the V₅₀/V₂₅ ratio and the dynamic compliance in 65 subjects (r=-0.74). In the same way, the V₅₀/V₂₅ ratio correlated significantly with the static compliance. There was a good correlation between the V₅₀/V₂₅ ratio and the mean pulmonary wedge pressure in 20 subjects (r=0.77). But the PF/V₅₀ ratio and the V₇₅/V₅₀ ratio did not correlate significantly with the compliance and the mean pulmonary wedge pressure. Therefore, it was postulated that the V₅₀/V₂₅ ratio was a good index for detecting pulmonary congestion or restrictive lung changes.
Subsequently we studied the flow-volume curve in 10 patients with acute myocardial infarction every week from the first week to the fourth week.
The forced vital capacity and the forced expiratory volume per second and the peak flow of these patients returned to normal values in the second week following infarction. But, the V₅₀/V₂₅ ratio did not return to normal value in the fourth week following infarction and the compliance showed a marked decrease in these patients. Therefore, these results showed that there was pulmonary congestion or restrictive changes of the lung in these patients in the fourth week after acute myocardial infarction.
In conclusion, we suggest that the V₅₀/V₂₅ ratio is useful as an index of pulmonary congestion or restrictive change of the lung in heart diseases.

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Histamine and a slow reacting substance of anaphylaxis (SRS-A) are released during anaphylactic reaction. It has been postulated that a variety of sympathomimetic amines were capable of inhibiting the immunologic release of histamine from passively sensitized human lung.
We also demonstrated that the release of histamine and SRS-A from passively sensitized guinea-pig lung tissues markedly decreased by preincubating with isoproterenol, aminophylline, prostaglandin E₂ and cyclic AMP and markedly increased by preincubating with prostaglandin F_2α and cyclic GMP.
The present investigation was conducted to explore the effect of aspirin and indomethacin on the anaphylactic release of histamine and SRS-A from passively sensitized guinea-pig lung tissues.
1) The release of histamine and SRS-A from sensitized lung tissues decreased markedly by preincubating with indomethacin, and the extent of decrease became dominant by increasing the dose of indomethacin.
2) The release of histamine and SRS-A from sensitized lung tissues increased by preincubating with aspirin, and the extent of increase became dominant dose-dependently. The extent of histamine release reached the maximum at a dose of 10^-4M aspirin, while that of SRS-A release reached the maximum at a dose of 10^-3M aspirin.

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We studied the effect of decreased plasma colloid osmotic pressure (COP) on lung lymph flow in anesthetized dogs.
In the first group, COP was reduced by slow infusion of saline while the hydrostatic pressure (HP) in the pulmonary vascular bed was maintained at normal levels. The reduction of COP caused an increase in lung lymph flow. When COP was reduced by 50 percent and 80 percent of control values respectively, pulmonary lymph flow was increased 2-fold in the former and 5-fold in the latter from the base line level. In the second group, COP was reduced with an elevation of HP by rapid infusion of saline. Lung lymph flow was increased markedly as compared with the first group with reduced COP at normal vascular pressure. Pulmonary lymph flow was increased 5-fold when COP was reduced to 50 percent of control values and pulmonary artery pressure (PAP) was elevated to 10mmHg from the base line levels and moreover, when COP was reduced by 80 percent and PAP was elevated by 20mmHg of the control, respectively, pulmonary lymph flow was increased 12-fold of control values.
When the change in pulmonary lymph flow was plotted against that in COP and PAP in the two groups, it was found that lymph flow in the lung increased almost linearly with the elevation in PAP-COP.

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The results of a study of 6 normal subjects, 15 patients with chronic bronchitis and 7 patients with pulmonary emphysema by a steady state xenon technique, and a large scintillation camera, combined with computer analysing technique were reported.
1) It was found that the regional ventilation to perfusion ratios of normal subjects showed nonhomogeneity between upper lung and lower lung.
2) In patients with chronic bronchitis, the abnormalities of the regional ventilation to perfusion ratios were demonstrated in 13 out of the 15 cases, and even in 12 cases judged as normal on routine pulmonary functions tests, regional zonal abnormalities could be demonstrated in all cases.
3) In patients with pulmonary emphysema, the abnormalities of the regional ventilation to perfusion ratios were demonstrated in 7 out of the 7 cases, and even in 5 cases judged as normal on routine pulmonary function tests, regional zonal abnormalities could be demonstrated in all cases.
4) It was concluded that regional ventilation to perfusion ratios abnormalities were of a higher grade and more common in pulmonary emphysema than in chronic bronchitis.

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Respiratory functions were examined in 56 healthy high school twin students to see the role of genetic factors in determining pulmonary mechanics, lung volumes, gas exchange and ventilatory responses to hypoxia and hypercapnia. Monozygotes (MZ, n=19 pairs) and dizygotes (DZ, n=9 pairs) were matched by age, physical characteristics and sex ratio. MZ and DZ were classified by blood types (ABO, Rh-hr, MN, S, Kell, Lewis, Duffy, Kidd, Lutheran, P, and Xg), fingerprints and facial appearance.
Analysis of covariance disclosed that FVC, FEV₁, and FEV₁% were genetically determined. The role of genetics was not elucidated in FRC, REF, V₅₀, V₂₅, Raw, SGaw, ΔN₂, CV/VC, PaO₂, PaCO₂, pH, and [HCO^-₃]. Ventilatory responses to normocapnic hypoxia and normoxic hypercapnia were also genetically controlled. The effects of smoking were not clearly demonstrated in terms of pulmonary function.
These results suggest that genetic factors are responsible, at least partially, for the variability of respiratory functions seen in normal subjects.

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The clinical and histological findings in a case of bronchial carcinoma with a history pulmonary of shell wound are presented.
Adenocarcinoma of the right lower lobe was diagnosed In a 53 year-old male. Thirty four years previously, fragments of a howitzer shell entered through his right back and a piece lodged within his right lower lobe.
He had not experienedced any chest disorder during the last 34 years, but bloody sputum appeared in the summer of 1978. Chest X-ray examinations showed an abnormal shadow in his right lower lung field. In the center of this abnormal shadow, a shell fragment could be observed surrounded by relatively translucent shadow. Sputum cytology showed class V, adenocarcinoma. His right middle and lower lobes were resected and his mediastinal lymph nodes were completely excised.
The resected right lower lobe contained a lot of scar, especially within S⁶, S⁸ and S⁹, due to the penetration of the shell fragments. A shell fragment was present in the peripheral part of B⁸ and had rough and granular surfaces. The edge of the fragment was as sharp as a knife. A large abscess had formed around the fragment and the wall of the abscess contained a scar continuous to S⁶.
Microscopic findings, showed the scar to contain many small respiratory ducts and hypertrophied arterioles. The respiratory ducts were surrounded with anthracosis. Well differentiated adenocarcinoma was found mostly around the scar.
The shape of the continuous scar, from S⁶ to the abscess wall of S⁸, appeared to follow the contour of the passage of the fragments. Although it is difficult to distinguish the stroma in the malignant lesion adenocarcinoma might have developed in the air ways which lay scattered throughout and/or around scar.

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