The mamillary body of the mammals always consists of two nuclei, the medial and lateral. The medial nucleus consists of small nerve cells and the lateral nucleus the large nerve cells. In the pigs and dogs, the cell group extends in a belt-like fashion towards the ventral side of the medial nucleus and reaches the lateral nucleus of the mamillary body forming an arch-like structure along the ventral side of the medial nucleus. This cell group is called nucleus inframammillaris. In the silver-impregnated specimen, the size and morphology of the nerve cells are quite similar between the lateral and the inframammillar nucleus, so that the nucleus inframammillaris should be considered to be a part of the lateral nucleus. Inside of the mamillary body, the nerve endings surround the nerve cell in the form of a terminal button. This would definitely indicate that the mammillary body is an interposed gray matter. The medial nucleus of the mamillary body of the Japanese monkey is further divided into the dense dorsal portion and the coarse ventral portion. In the dense portion, the arrangement of the cells is dense and the arrangement of the nerve fibers is complex. Fuse1) found the formation of the cell folds in the medial nucleus of the mamillary body in 5 kinds of monkeys, suggesting an intimate relationship between the nerve fibers entering into and emitting from the mamillary body and the cellular elements in the mamillary body. The observations in the Japanese monkeys tend to support Fuse's concept.
It is very important to know the critical pressure which causes a living body to bring about histological damage or destructive metabolism when the hyperbaric effect is studied. Therefore, a histological examination was made on hydrostatic pressure effect on the muscle in the tadpole tail of the bullfrog (Rana catesbiana) by using an animal chamber which is able to compress a liquid from 1 to 500 atmospheric absolute (ATA). More than 200 tadpoles were compressed at the different depth of pressure between 7 and 500 ATA. The results of the experiment may be summarized as follows: (1) The interstices between the muscular fibers are found at above 50 ATA for 10 minutes, and at 500 A TA for 30 seconds. (2) Stiffness is seen at 500 A TA for 60 seconds or over. (3) The “rounding fibers” are often found by exposure to 100 AT A for 10 minutes, and more often found at over 300 ATA. (4) The macroscopic stiffness is due to the histological “rounding fibers”. (5) The damage to the muscle is caused more by decompression than by the compression effect.
Eleven cases of so called neonatal necrotizing enterocolitis confirmed by autopsy or biopsy were studied. They were characterized clinically by diarrhea, fever, vomiting, abdominal distension, and shock. Autopsies of 10 cases revealed multiple ulcerations of the small and/or large intestines and their occasional perforation followed by peritonitis. Changes found in other organs were fatty change and cholestasis of the liver, atrophy of the lymph apparati, and generalized congestion. Intestinal change of the remaining one case was confirmed with surgical specimen, the finding of which was the same as above. It is postulated that the main changes observed in this syndrome should result from acute circulatory disturbance of the gastrointestinal system, perhaps occurring during the course of some intestinal infection.
In twenty-eight gastric cancer cases the MLTC was performed. X-ray-irradiated tumor cells or MMC-treated tumor cells were cultured with autologous lymphocytes and with 3H-thymidine added. In the autoradiography group 2 out of 8 cases and in the liquid scintillation counter group 3 out of 20 cases the uptake of 3H-thymidine by the cells increased more than in the controls. In observing the results of the 1st and 2nd culture in the autoradiography group, and effect of lymphocyte reactivity following the surgical removal of the tumors was observed.
The present experiments were made by mixing dextranase with a soft feed for Macaca mulata, so as to both clinically and biochemically investigate the effect of this enzyme on the plaque formation and the mechanism of its effect. As a result of the proper area method, the test animals treated with dextranase and the control animals showed a significant difference in plaque formation at any stage, 2, 4, 7, 14, or 21 days after the start of the experiments (p <0.01). Equal quantity of samples of the 7 day old dental plaque was then collected from both the test and control animals; soluble and insoluble polysaccharide fractions were extracted from the samples, and assayed for total sugars. The soluble polysaccharide content in the samples from the group treated with dextranase decreased to about 1/100 of that in the samples from the control group, and the insoluble polysaccharide content in the former decreased to about one-half of that in the latter. The polysaccharide fractions so extracted were then hydrolyzed, enzymolyzed, and analyzed by infrared absorption spectrometry, and it was revealed that the major part of the soluble polysaccharide fraction was composed of soluble dextran-like substances, and that of the insoluble fraction consisted of insoluble dextran-like substances.
For increased efficiency of dental casting procedure, an electric furnace with three rooms thermostatically controlled to three different temperatures was devised. Adequate temperatures for individual rooms and the time required for keeping rings in them were experimentally determined. The furnace is now successfully being used, without producing any fins on castings due to investment cracking.