Acta Medica Okayama volume25 issue1

Mononuclear cells from rabbit joint fluid were studied after synovitis was induced by various means, including the intra-articular injection of bacterial endotoxin or of aggregated human gamma globulin in normal rabbits, or of HGG in rabbits previously sensitized to this material. The large majority of mononuclear cells in all groups were monocytoid rather lymphocytoid, and these cells were most readily labeled with tritiated thymidine on the first day after injection. On day 2 and 3, the numbers of labeled cells decreased, except for the animals previously sensitized with HGG, in which there was an upswing of labeling on day 3. This upswing was associated with a considerable increase in numbers of cells resembing synovial cells, and may possibly be a reflection of synovial proliferation. Macrophages loaded with engulfed polymorphonuclear cells were observed in all experimental groups, a finding which emphasizes the lack of specificity of this reaction.

In an attempt to eliminate Japanese encephalitis virus in natural surroundings, pigs having maternal antibody were given inoculation of live-attenuated Japanese encephalitis vaccine and injection of Freund's complete adjuvant simultaneously. Titer of hemoagglutination inhibiting antibodies of pigs inoculated with live attenuated vaccine and complete adjuvant, was higher than that inoculated with vaccine alone and its titer persisted.

In vitro cell transformation of human embryo cells could be induced by the DNA purified from SV 40. The result shows clearly that cell transforms a part of viral DNA into the genome. In addition, for the purpose of clarifying th~ biological differences between the normal and transformants the alteration of cell membraneous structures of transformants (hamster and mouse fibroblasts) were observed from mechanism of phagocytosis. The iron colloid particles are taken up by normal diploid fibroblasts but not by the human and hamster transformants. This fact suggests a differ~nce in the molecular arrangement of the cell membranes between the normal and transformants. In the presence of histones, however, the transformants phagocytize the colloid particles very actively. The results show that cell membranes of transformants are altered in the molecular structure r~sponsible for the surface charge. In addition, there is no remarkable quantative differences of sialic acids on the cell surfaces of non-malignant and malignant transformants so that phagocytic activity might be correlated to the alteration of molecular composition of cell membrane itself rather than of cell surfaces, i. e, sialic acids.

The incorporation of tritiated thymidine into DNA molecules was studied by electr.:m microscopic autoradiography. To make autoradiogram in electron microscopic level, DNA was extracted from rat ascites hepatoma (AH 130) cells after in vitro incubation with tritiated thymidine. Extracted DNA samples were rotary shadowed with platinum palladium and covered with emulsion. Silver grains demonstrated on autoradiogram indicated tritiated thymidine to have incorporated into DNA molecules themselves. The incorporation was further confirmed by liquid scintillation counting of TeA soluble and insoluble fractions after DNase or RNase treatment of the DNA preparations.

Ring DNA from rat liver mitochondria has been examined by circular dichroism (CD) in the region of the 225 to 320 m/~ and the followings have been clarified. The ring DNA gives a CD spectral curve somewhat different from linear DNA from nuclei, showing a big positive peak at 266 m/~ and a small negative band at 243 m!~. That is, the positive CD band of ring DNA shifted by about 7 m/~ to the shorter wavelength side from the band of the ordinary nuclear DNA, 273 m!~. Negative band appeared at the same region as that of linear DNA but reduced in depth. Heat denaturation of the ring DNA induced a red shift of the positive band, by about 4 mp., but no change in negative band. From these experimental results it has been concluded that the ring DNA has highly twisted conformation and high in G.C contents, both of which are responsible for the blue shift of the CD spectrum.

For the purpose to investigate the physiological functions of microvillus ATPase, general properties of the enzyme were studied on the microvillus membranes isolated from rabbit intestinal epithelial cells. 1) ATPase of the microvillus membranes was activated with Mg2+. Mg.ATP complex was thought to be a subStrate of the enzyme. The Michaelis constant for ATP of the ATPase was a value of 0.8 to I .0 mM. 2) The microvillus ATPase was also activated with Ca2+, but the affinity was lower than a half of that of Mg2+. 3) The optimum pH of the ATPase was about 7.8. 4) Activity of the microvillus ATPase was markedly inhibited by treating with deoxycholate (DOC), and the activity inhibited was partially restored by washing the microvillus membrane with distilled water. The structure of the membranes destroyed by treating with DOC was also partially restored by the same procedure. 5) Ultrasonic treatment also markedly destroyed the microvillus membrane and inhibited ATPase activity. Damaged ultrastructure and ATPase activity both were partially restored by treating with phospholipid, EPL. 6) Simultaneous presence of Na+ and K + stimulated scarcely the ATPase of purified microvillus membranes. 7) The microvillus ATPase was slightly activated in the presence of n-glucose. Phloridin gave little effect on the activity of the microvillus ATPase.

We applied unidirectional MLC test to renal allograft in dogs, and investigated the correlation between the growth rates of MLC reaction and the intensity of rejection of the kidney transplants or the postoperative renal function. It was concluded that the grade of rejection became three plus (+ + +) when the rate of blastformation was more than 18 %, while it became one plus when the rate was less than 15 %. The rate of blast. formation was closely correlated with the strength of rejection of kidney transplants. However, the postoperative renal function was not always correlated with the mixed lymphocyte reaction.

For the purpose of elucidating more exact relationship between the process of carcinogenesis and aggregate-forming ability, we performed rotation cultures of a series of five liver cell lines derived from rats fed DAB for various period of d:l ys. As a result we found a tendency of the cells obtained from rats fed DAB for a longer period to form larger aggregates. The differences of the aggregate.forming ability among these cell lines were demonstrated well within one day, and more prominently after three days in rotaion culture. Histologically, the aggregates of all cell lines were composed of cuboidal epithelial cells, especially in some cell lines showing gland-like structures.