By the method of electrostimulation, the cone- and the rod-proc-esses following two successive flashes of white light were separately investigated in the human retina. 1) The cone- and rod-responses to two flashes, conditioning and testing, are in shape almost identical with their responses to the testing flash alone, but the magnitudes of the responses are greater for the two flashes than for the single. This phenomenon is called summation. 2) For summation to occur, the intensity of the conditioning stimulus relative to that of the testing is important. No summation occurs at all when the conditioning stimulus is weaker than the testing. 3) When the interval between two flashes is shorter than 1.5 seconds, inhibition occurs, instead of summation. At intervals longer than 2 seconds the degree of summation is almost constant irrespective of the interval. Summation can still be seen at such a long interval as 20 seconds. 4) The degree of summation is greater for the rod-process than for the cone-process. We are greatly indebted to Prof. K. Motokawa for his many valuable discussions and kind guidance.
Experimental study was carried out to observe the mechanism of return of cardiac rhythm after defibrillation of a fibrillating heart caused by electric stimuli, with following results: 1. Cardiac rhythm is restored by countershocks if applied within 3 minutes. 2. As hypercapnia increases, the irritability of cardiac muscle increases also. Ventricular fibrillation is hard to remove by countershocks and reccurs also easily after its removal. 3. As anoxia weakens the contractility of cardiac muscle, resusci-tation of the heart becomes difficult. 4. Ventricular fibrillation under hypothermia is difficult to remove by countershocks. Electric shock, however, seems to be the most ef-fective method for its abolition.
Cardiac arrest frequently encountered in routine treatments was caused experimentally and resuscitation was attempted. 1. Occulusion of trachea causes cardiac standstill. When obstruction is released within 13 minutes and artificial respiration with 100% oxygen is carried out, cardiac rhythm recovers by cardiac massage. 2. Occlusion of the main stem of left coronary artery causes ventricular fibrillation. It cannot be abolished by countershocks without release of obstruction. Ventricular fibrillation by occlusion of right coronary artery, and peripheral branch of left coronary artery can be both successfully removed by electric shocks. 3. Oversupply of acetyl choline causes cardiac standstill. This can be resuscitated satisfactorily by cardiac massage and injection of atropine. 4. Acute massive bleeding causes cardiac standstill. Once the cardiac rhythm stops, resuscitation is almost impossible. In such cases, ECG, or macroscopic observation of the heart rhythm do not serve as a danger signal of cardiac arrest. Adequate control of transfusion should be carried out with attention to the amount of lost blood, changes of blood pressure and pulsation. 5. Narcotics as barbiturates and chloroform cause cardiac arrest. As their prognoses are bad, prevention of their occurrences should be carried out before hand. 6. The effect of injection of epinephrine, procaine amide and cardiac massage upon the heart muscle were discussed. Especially, assisted massage should be carried out carefully, when the irritablity of heart muscle is increased.
Resuscitation of cardiac arrest was studied on the damage of cerebral function by EEG and histology. 1. The cerebral cortex has the least resisting ability to anoxia, and potentials of cerebral cortex disappear within 15 seconds after venticular fibrillation. 2. After ventricular fibrillation, the time limit to prevent irreversible damage of cerebral function is suspected to be 2 minutes. 3. If cardiac masage is started soon after ventricular fibrillation, no abnormal findings are recognized even when defibrillation is attempted after a long time. 4. In the case of cardiac arrest due to tracheal obstruction, it is possible to recover the heart without leaving permanent damage of cerebral function after release of the obstruction of the airway with restart of cardiac massage.
1. Mothers in Hirosaki area show, as has been repeatedly shown by us, clinical symptoms of nutritional dystrophy. 2. Exclusively breast-fed infants of these mothers, as has been shown by Kagaya, do not show clinical signs of nutritional dystrophy. 3. These infants, however, show in electrophoretic pattern of serum protein, a decrease in albumin and an increase in gamma globulin. 4. So these breast-fed infants without clinical symptoms of nutri-tional dystrophy show a close nutritional connection with their mothers with distinct clinical symptoms of it in that peculiar electrophoretic pattern of serum protein.