1. It was demonstrated in experimental animals that striking blows to the external nose caused similar processes in the development of malformations as seen in wrestlers and boxers. Incessant light blows to the nose of a guinea pig produced results similar to the thickened dorsal surfaces of noses in wrestlers and boxers, and incessant strong blows to a guinea pig resulted in appearances corresponding to the advanced traumatic malformations seen in wrestlers and boxers. 2. Of the various types of traumatic malformation occurring in wrestlers and boxers, slant and curl noses could net be found in guinea pigs. The traumatic protuberances due to fracture of cartilage observed in wrestlers and boxers develop on the line joining the nasion and nasospinole, but in guinea pigs they occur in the upper one-third portion as revealed by study of vertical sections. It is considered that this difference arises from the dissimularity of anatomical structures in humans and experimental animals.
According to histopathological studies in animals, the effects of dihydrostreptomycin and INAH administered intrathecally were initially revealed in the peripheral Corti's organ and then extended to more central acoustic elements. There was no close relation between these histopathological findings and the dosage of dihydrostreptomycin and number of intrathecal injections. Experimental animals given INAH Intrathecally sometimes died following an attack of convulsions but there was no particular histopathological finding in the accoustic organ. Since it is well known clinically that even one intrathecal injection of dihydrostreptomycin may produce deafness, whereas the side-effects of INAII employed intrathecally are reversible, the intrathecal administration of INAH is more desirable than that of dihydrostreptomycin when such a therapeutic methcd is required.
Intrathecal administration of DHSM to guinea pigs resulted in the death of a majority of the animals. However, concomittant intramuscular injections of vitamin A or B1 decreased the death rate of the experimental animals, especially when both vitamins were administered. It was also confirmed histopathologically that the combined intramuscular use of vitamins A and B1 is useful in preventing to a certain extent damages in the acoustic organ caused by DHSM. In animals receiving intramuscular administration of DHSM combined with intrathecal injection of vitamin B1, the grade of damage in the acoustic organ was less significant than when only intramuscular injection of DHSM was given. As the result of these findings, it is considered that the intrathecal use of vitamin B1 is of value in preventing to some extent damages in the acoustic organ ca used by DHSM.