Saburo Yamagiwa

Parathyroid Glands in Equine Osteodystrophia Fibrosa

Histological studies on parathyroid glands have been made by specialists in various countries ever since started by WELSH. The authors have recently been engaged in investigating egt4ize osteo&strophia jbrosa histologically. The findings contained in this report pertain to the histological chages of parathyroid glands obtained from 100 cases affected with the subject disease. The authors, in this investigation, studied the classification of histological changes of objects depending on confirmable pattern on the stained preparations. They subsequently investigated the relation between bone changes and parathyroid glands centering around the existence of pattern and swelling in parathyroid glands. Bone changes were classified into the types of severe bone change, mild bone change and silent bone change. It is certain that a close mutual relation can be so often observed between the pattern formation and swelling in parathyroid glands and the type of severe bone change. However, some cases in other types of bone changes also manifest the existence of pattern and swelling, and some in the type of severe bone change do not show pattern and swelling. In consequence, the authors wish to set aside detailed investigation as a future problem, and yet it is not deniable that important significance should be laid on the hyperplasia of parenchymatous tissue of parathyroid glands in the disease. In giving solution to the pathogenesis of osteo4stmphia jbrosa, the authors would like to hold an attitude not to give preceding role to changes of parathyroid glands.

Muscle lesions in embryos and chicks on the day of hatching.

Histopathological studies were carried out on skeletal muscles of 1, 723 individuals consisting of embryos, and abnormal and normal chicks which had been collected on the days of hatching during the same year. Muscle lesions were readily found in 360 (21%) of the specimens at low-power magnification microscopy. Muscle fibers in the lesions showed mainly focal swelling, focal rarefaction with a lack of myofibrils and sarcoplasm, and the appearance of basophilic substance. Some of the lesions were associated with mild reactive changes in the interstitial connective tissue. Based on the findings of rarefied areas in the affected muscle fibers, a pyesumption was made that these muscle lesions might have occurred in immature muscle fibers and be regarded as a hypoplastic change.

満洲において流行する家禽ペストに関する研究 : IV. 家禽ペスト継代ウィルスによる鶏中枢神経組織病変について

In 1932 and 1938, one of the authors, YAMAGIWA, studied the histopathologicalchanges in the brain autd spinal cords of chickens infected naturally with fowl plaguein Manchuria. Moreover, he and his associates published three papers on experimentalwork with fowl plague passage virus. This paper deals with neurohistopathologicalinvestigation of the brain and spinal cord carried out on experimental cases with thefowl plague passage virus mentioned above.The materials and methods used in this study had been described in the previousreport, part 111.9) The viruses used were the Hoten A (A) and European strains (D).The chickens used were White Leghorn adults. Chicken brain emulsion containingthe virus was used as inoculum for chickens by the intramuscular route. Microscopicalexamination was performed on a total of 13 chickens. The experimental history ofthese birds was shown in Tables 2, 4, and 6 in the previous report, part [119).The basic histological changes were confined consistently to the ectodermal tissue, and composed mainly of focal microglial proliferation, which was occasionally accom-panied by a few oligodendroglial cells. The glial lesions were divided roughly intotwo groups, nodular foci (Fig. 4) and minute foci (Figs. 3, 6, 7, and 8). The formerwas well-defined, spherical in shape, and generally larger than the latter though vari-able in size. The latter was very minute in size and irregular in shape. A large numberof proliferated glial cells were arranged compactly in the former, but a few proliferatedglial cells were presented sparsely in the latter. It was difficult to find out whethertlae nodular foci were related to nerve cells, blood vessels, or non. On the other hand, the minute foci were often closely connectd with blood vessels, chiefly capillaries.There was a relationship between the occurrence of lesions and the inculated doseor virulent materials (Table 1). In cases given 10-2, 10-3, NO-4, and 10-5 g of brainmaterials, the lessions were predominantly large in number, while they were very small noticed. Changes in the mesenchymal tissue were scarcely observed in chicken inocu-lated experimentally with fowl plague passage virus. Some discussion, thereupon, wasmade on histogenesis in microglial reactions to viral infections.

Encephalitis Epidemica Japonica in Horses Occurring In a Non‐Epidemic Year

The authors have carried out investigations on horses with cerebral symptoms clinically, pathologically, and epidemiologically which were obtained in various areas in Hokkaido in non‐epidemic years—1955, 1956 and 1957. Among cases investigated, there were three cases in which the authors could certainly prove the existence of encephalitic changes histopathologically in addition to two cases, one being positive to the complement‐fixation test and the other in virus isolation. In five out of eighteen cases investigation, slight leucocyte emigration was observed in the brain tissue. Comparing such facts with the judgement from the viewpoint of epidemiology and differential diagnosis, the authors have concluded that all of the cases with encephalitic symptoms were infected with Japanese encephalitis (Encephalitis epidemica japonica). They have also added considerations pertaining to the infection‐pathology of Japanese encephalitis based upon the discrepancies in infected horses between epidemic and non‐epidemic years.