Boyden's tannic acid hemagglutination technique as modified by us was used to study streptococcal type-specific antibodies. The type-specificity of the reaction was demonstrated in many fundamental experiments. Three hundred one sera, including sera from patients with rheumatic fever, rheumatic heart disease, miscellaneous heart diseases, nephritis, scarlet fever, rheumatoid arthritis and appropriate controls were investigated with 42 of Lancefield's 48 types of Group A Streptococci. Most sera from patients with rheumatic heart disease showed significantly high titers in two or more types. How-ever, the sera of individuals with non-rheumatic heart disease and without disease, this was rarely seen. It is suggested that the number of types with high titers correlates with the recurrences of rheumatic fever and aggravation of rheumatic heart disease. Our studies reaffirm the close connection of rheumatic fever and rheumatic heart disease with streptococcal infection, and suggest a justification for the long-term prophylactic use of penicillin in patients with rheumatic fever.

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(1) Twenty-seven cases of rheumatic fever and rheumatic heart disease were examined for liver status.
(2) In 50%, Al-P was elevated. Other liver function tests were ab-normal with lesser degree.
(3) No correlation between elevated Al-P and ZTT, CCF, ESR, ASL-O titer, SGOT, SGPT, ECG findings and clinical course.
(4) Elevated Al-P activity tended to develop among patients with murmur at aortic valve.
(5) These abnormalities seemed to be temporary and reversible.
(6) No specific histological findings enough to be called "rheumatic hepatitis" were noted in histological examinations.
(7) Possible causative factors for elevated Al-P in rheumatic diseases were discussed.

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The average yield of acid mucopolyscaccharides extracted from defatted and dried Japanese aortas was 10.6, 11.6 and 6.9mg. per Gm. for individuals aged 0-19 years, 20-69 years, and 70-91 years respectively. A diminished yield found with advancing atherosclerosis proved statistically significant. A similar relationship in a U.S.A. sample has been observed by Kirk. Com-paratively, the AMPS content of Japanese aortas in the first six decades was appeared to be less. In Japanese aortas the major portion of the isolated AMPS was metachromatic.
As in an American population, aortic cholesterol, calcium, magnesium, and atherosclerosis increased with age but the process was delayed two to three decades in Japanese.

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(1) The renin-angiotensinogen reaction has been utilized to determine the renin in small specimens of kidney tissue.
(2) The pretreatment of rat or human kidney extract at pH 3.0, 0°C, for 30 min. gave a reliable method to remove angiotensinase.
(3) The pretreated extract of various concentrations was reacted on the plasma at pH 6.5, 37°C, for 10 min.
(4) Angiotensin thus formed was determined by its pressor action in the rat anesthetized by pentobarbital and treated by pentolinium.
(5) It was shown that, to express the amount of renin, the reaction con-stant (K) as expressed per original concentration of the kidney extract and per min. may be used.
(6) The method is applicable to as little as 0.01 Gm. of renal tissue.

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The nature of the spread of excitation of atrial musculature in the very vicinity of the A-V ring was studied by means of intracellular microelectrode. The records obtained from this region showed progressive decreases in depolarization rate and amplitude of the depolarization upstroke as the A-V ring was approached. These 2 factors, the decreases in the rate and amplitude, will give a less effect as a stimulus.
The shape of the membrane action potential recorded from the cells in this region was similar with that from the A-V node and the diastolic slow depolarization was often recorded from a cell group localized in the region posteriorly to the coronary sinus orifice.
The QRS complex of the unipolar lead electrogram led from the same point where the microelectrode was plunged was compared with the depolarization upstroke of the membrane action potential. The onset of the sharpest downward deflection of the intrinsic deflection was nearly synchronous with the onset of the sharp upstroke of the membrane action potential. The small initial slow component of the membrane action potential was surmised to reflect the potential change extrinsic to the cell penetrated.

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(1) The origination and transmission of stimulus in right atrium of the canine or rabbit heart were studied by means of intracellular microelectrode method.
(2) The area showing pacemaker potential pattern was localized in a area anterolaterally to the basal part of superior vena cava. The length was about 4.0mm and the breadth was also about 4.0mm. The true pacemaker potential pattern was obtained from slender zone within this area.
(3) The spread of activation in this area was more or less radially in direction and almost constant in velocity except one direction along the zone toward crista terminalis showing true pacemaker potential. In this direction, the conduction rate was rather high and it was about 0.08M./sec.
(4) After reaching crista terminalis, the activation was conducted with more accelerated velocity toward postero-inferior rand of the coronary sinus orifice and atrial septum through the right and septal branches of crista termi-nalis respectively. The conduction rate was about 1.5M./sec. which was the highest in the atrial musculature.
(5) In the atrial free wall, the activation coming along through the crista terminalis was transmitted to mm. pectinati for farther conduction toward the A-V ring. The atrial roof musculature was activated by stimulus coming through a nearby m. pectinatus. The conduction rate through m. pectinatus was greater than that through atrial roof but was less than that through crista terminalis.
(6) By cutting the crista terminalis or injecting osmic acid solution into this musculature, the stimulus conduction to distal portions of crista terminalis was markedly delayed. It was supposed that both branches of the crista termi-nalis played the most important role in stimulus conduction in the right atrium.
(7) It was supposed that the musculature in the vicinity of the A-V node was activated by the stimulus coming along through 2 routes, one through the right branch and the other through the septal branch of the crista terminalis. At an area near the boundary of septal musculature and the A-V node, the conduction rate of activation wave showed marked decrease. A-V node was verified by its typical pattern of the membrane action potential.
(8) The conduction rate of the activation wave in the area close to A-V ring became progressively decreased as the ring was approached and the activation was not transmitted beyond the ring. With this progressive de-crease in the conduction rate, the membrane action potential also gradually decreased in the steepness of the sharp depolarization upstroke. It was speculated that the changes in membrane action potential were an important cause for the constant blockade of stimulus conduction between atrial and ventricular musculature.

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