Endocarditis was experimentally produced in rabbits by streptococcus sanguis, rabbits brain phosphatide and their combination in order to study several factors for development of the disease and the histogenesis with reference to the time interval between the injection and the onset of endocarditis.
Results were as follows:
1) Only a mild damage of endocardium was caused by the every other day injection of either phosphatide or bacteria alone, representing a mild valvulitis characterized by edema, localized swelling of endocardial cells and swelling of fibrocytes. A real bacterial endocarditis could be only produced by the combined use of the two (every other day injection).
2) Follow-up studies on the histologenesis of experimental bacterial endocarditis revealed that even a single injection of either str. sanguis or phosphatide produced various histologically different changes.
These were:
a) Thrombus attached on the desquamated endocardium which gradually increased in size resulting in the cellular infiltration in it.
b) Proliferation of histiocytic cells in the subendothelial layer.
c) Serous inflammation of the subendothelial layer (Eöhmig).
Any one of the above mentioned changes may lead to the bacterial endocarditis.
3) Bacterial colonies in the endocardial foci, especially in the fibrin thrombus or in the fibrinoid substance could not be found until the stage of advanced leucocytic infiltration in the thrombus, histiocytic infiltration in subendothelial layer and appearance of the fibrinoid substance in it.
4) When these changes, cellular infiltration and histiocytic reaction further advanced, then the lamina elastica became loose, torn and destroyed resulting in ulcer formation.

View full abstract

An influenza epidemic occurred around the end of March, 1959 at Camp Iwate of the self defence force stationed in Takizawa village which lies about 20 km north of Morioka City. Out of 1, 223 soldiers, 363 contracted the disease, the morbidity rate being 29.7%.
The epidemic began soon after the arrival of a new group of soldiers from Camp Hachinoe in Aomori Prefecture. Out of 117 soldiers of B company joined by 15 of the new arrivals, 51 (43.6%) contracted influenza.
Serological tests with the convalescent sera revealed that 9 of the 27 sera tested gave high agglutinin titer against A₂ type virus, while all the sera tested showed any rise of the antibody titer neither against A type nor against B type of the virus. Six influenza viruses were isolated by both amniotic and allantoic inoculation of fertile eggs. All of these were revealed to be antigenically similar to A₂ type strain.

View full abstract

An influenza epidemic-from 22th March, to 24th, April-as experienced by the authors in March, 1959 at Yashikidai in Matsuo Village.
The morbidity rate was 21.7% and 11.6% in the school children and the adults, respectively. The principal symptoms were cough (53.6%) and headache (47.1%).
Three influenza viruses isolated by both amniotic and allantoic inoculation were all similar to the A₂ type strain antigenically.

View full abstract

The investigation of staphylococci, especially their persistency, isolated from the mares of staffs and patients of J and K Hospital in 1956 and 1957, was carried out, using the examinations of biological characters, antibiotic sensitivity and phage-typing.
On the experimental infections of animal skin, inflammatory reactions were observed Rs indicator, and influences of antibiotics were also examined.
The experiments of inoculation on human nose, using resistent staphylococci, were tested.
Their results were as follows:
1) One thousand three hundred sixty four strains of staphylococci were isolated from 114 persons of both hospitals. Among those strains, 241 pigment-producing strains were found (18%), 202 coagulase-positive (15%), 343 mannite-fermenting (25%). By the long-termed observations of 114, 48 carriers of coagulase-positive staphylococci were detected.
2) The distribution of resistent srains was significantly different between J and K Hospital; the former being 31%, and the latter 54%. Concerning the kind of antibiotics, streptomycin resistent strains were mostly found in J Hospital, while on the other hand, in K Hospital, tetracycline resistent 46% and chloramphenicol resistent 30%. It is considered that the rate of resistent styains and the difference of the kind of antibiotic were closely connected with the frequency of use of the drug.
3) It was possible to classify 64% of those strains by using the phage-typing.
Most of those belonged to group 3 (66%), and resistent strains were also found mostly in group 3.
4) According to the continuous observation of 114 persons for a long period, the rate of persistently positive carriers of coagulase-positive strains was 18%, and that of the same phage-pattern 15%.
Persistence of certain strains was thus recognized, which was considered to be a possible the origin of an epidemic.
5) The strain of phage-pattern 77 was isolated in 17 instrances out of 25 persons at K Hospital (68%). A transmission and an infection from one person were recognized.
6) On the inoculating experiment of staphylococci on rabbit skin, the size of reaction zone of skin was measured; reaction by inoculation of resistent strain was slighter, but it had a tendency to develop by the use of antibiotic.
7) On the inoculation experiment of human nose using resistent strain against penicillin, the strain was continuously isolated, when penicillin was given; but, with out use of penicillin, no strain was found. Namely, when resistent strain was inoculated, the use of the antibiotic promoted the persistence of the strain on nasal mucous membrane.

View full abstract

For the study of ASLO titer, the following investigations were first carried out from the angle of microorganisms i. e. the quantity and discharge duration of streptococci, the type of A group strains isolated and it's in vitro productivity of streptolysin was studied using the method of Kusama et al.
Concerning the investigations on the host side, the highest value and the grade of increasement of ASLO titer were determined in correlation with the type and the productivity of streptolysin 0 of the agent isolated. ASLO titer was measured by the method of Kusama. The diagnostic value of ASLO titer in scarlet fever was also discussed in this paper. The results were as follows:
1) The lysin productivity of 163 strains isolated differed considerably from strain to strain, but the strains of type 3 demonstrated in general a higher productivity as compared with the other types.
2) ASLO showed hardly any effect for the prevention of scarlet fever.
3) Because of a certain upper limit of ASLO titer, the cases which had demonstrated a low value at the beginning of the disease later reached a high level, whereas the cases with a high value from the beginning tended to demonstrate only a little increase in the later stage.
4) ASLO titer tended to rise higher, when infected by a strain endowed with a high ability of lysin production.
5) The ASLO titer can only be used for the diagnosis of scarlet fever, when an increase of the titer is observed in the course of the disease.

View full abstract

Three hundred fourty three strains of pathogenic E. coli (7.43%) were isolated from 4, 617 persons during 4 years (1956-1959) in Tochigi Prefecture. Out of 343 strains isolated, 332 strains were investigated on their carbohydrate-fermenting activity and classified into 36 types. O-26 strains were classified into 5 types, O-28 a, c into 2 types, O-55 into 4 types, O-75 into 4 types, O-86 into 8 types, O-111 into 4 types, O -112 into 4 types, O-119 into 5 types, O-124 into 2 types, O-125 into 21 types, O-126 into 3 types, O-121 into 3 types and O-128 into 8 types, respectively.
There were 3 strains (0.9%) fermenting inosite, 64 strains (19.3%) fermenting adonite, 109 strains (32.7%) fermenting salicine, 193 strains (58.1%) fermenting sulcite, 237 strains (71.4%) fermenting saccharose. The other carbohydrates such as sorbite, arabinose, xylose, rhamnose, maltose, lactose, mannite, glucose and trehalose were fermented by most of these strains.
Fifteen strains (4.5%) were indol-negative, 4 strains (1.2%) H2S-positive, 5 strains (1.5%) growing on Simon's medium and 21 strains (6.3%) hemolytic.
Lactose-non-fermenting strains of O-111 and indol-negative strains of O-125 and 0-127 were hemolytic.
The growth of strains isolated were inhibited on the SS medium in 26.5%.

View full abstract

Three hundred and thirty two pathogenic strains of E. coli (13 types) isolated during 4 years (1956-1959) in Tochigi Prefecture were investigated on their sensitivity against various antibiotics.
All of the 138 strains isolated in 1956-1957 were sensitive against antibiotics. Twelve (6.2%) out of 194 strains examined in 1958-1959 were resistant against antibiotics.
Among these, one strain (O-28 a, c) was resistant against streptomycin, 10 strains (7 strains of O-126 and 3 strains of O-128) against tetracycline alone and another one strain (O-126) against streptomycin and tetracycline.
Out of 12 strains, one (O-28 a, c) was isolated from a sporadic case, a healthy adult, whereas all the other strains were obtained from epidemic cases of a sucklings' home.
Regarding the grade of resistance, 88.2% of the strains isolated demonstrated a resistance of 3.12-6.25 γ/cc against chloramphenicol, 92.5% a resistance of 1.56-3.12 γ/cc against streptomycine and 87.5% a resistance of 1.56-3.12 γ/cc arainst tetracycline, respectively.
Antibiotic-sensitivity was not at all related to the type of strains, however, O-124 demonstrated a little lower value as compared with the other types.
Examination on the antibiotic-sensitivity of ordinary E. coil isolated from 448. persons revealed that none of the strains were resistant against chloramphenicol.
Tetracycline-resistant strains were sought from 172 persons, revealing resistant strains (100 γ/cc) in 16 persons (9.3%). Most of them had been once treated with tetracycline.

View full abstract