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Electron microscopic observation was made on the length distibution of messenger RNA molecules in polyribosome pre· paration isolated from mouse ascites sarcoma cells, which was de· stroyed by ethylenediamine tetraacetate treatment in hypotonic solu. tion. The ribosomes appeared first to be a hollowed structure by swelling and then were destroyed to a rod·like structure consisting of ribonucleoprotein strand, which was clearly distinguishable from the linear structure of messenger RNA released from the polyribosomes. The length of messenger RNA was poly.dispersed measuring from 0.02 up to 6 μ, the majority (92%) of which was in the length less than 3 μ with a prominent peak between 0.6 to 0.8 μ.

The appearance of sideroblasts in hypoplastic anemia (HAl and acute myelocytic leukemia (AML), together with their sideroblastograms, was studied. Hematological studies on cases with type III sideroblast dominance by sideroblastograms produced the following results. Type III sideroblast dominant HA was observed in three of 63 cases. Two of the above three cases had what we call "atypical factor", while the remaining one became AML in its clinical course and could be considered to be leukemia in a hypoplastic preleukemic stage. Type III sideroblast dominant AML was noted in five of 32 cases. Three of these five cases are compatible with low percentage leukemia, and one of the above three cases showed ringed sideroblasts exhibiting erythroleukemia in the terminal stage. In HA and AML, type III sideroblast dominant cases have to be examined in relation to atypical HA and atypical leukemia. Changes of iron meta. bolism in erythroblasts with preleukemic stage will be attributable to disturbance of erythropoiesis such as erythroid hyperplasia in bone marrow and also, in part, to disturbance of hemoglobin synthesis.

For the purpose to reveal the changes in stimulatory effect of dibutyryl-cyclic- AMP on erythropoiesis during ontogenetic development, the author studied syntheses of DNA, RNA and protein of erythroid cells in fetal liver, neonatal and adult bone marrows of rats. In the bone marrow of neonatal animals erythropoiesis was stimulated by the intraperitoneal injection of cyclic nucleotide with enhanced DNA, RNA and protein syntheses of erythroid cells. Enhancing effect of dibutyryl-c-AMP on the erythropoiesis decreased gradually with advance of neonatal days. Autoradiographic observations revealed that in erythoid cells isolated from fetal liver and neonatal bone marrows, DNA-, RNA- and protein-snythesis was markedly stimulated by incubating with cyclic nucleotide, but not in those from adult bone marrow. Discussion was made on the changes in the regulatory mechanism of erythropoiesis according to the transition of hematopoietic organs during development.

The effect of immunization with hamster fetal cells on the tumor induction by adnovirus type 12 was studied by in vivo and in vitro. The immunization with lO-day old fetal cells showed a recognizable inhibition on the tumor induction by adenovirus type 12. The inhibition was observed only in males but not in females. For the inhibition, immnization with 107 or more cells was required. The immunization with same dose of l2-day-old fetal cells were ineffective. The inoculation of the spleen cells from hamsters immunized with un· irradiated fetal cells strongly inhibited the adenovirus·12 onocogenesis. Membrane immunofluorescent test, however, failed to demonstrate the fetal antigens in any of adnovirus-12-induced tumor cells, SV40induced tumor cells and cells from spontaneous hamster lymphoma.

A new cell line "CK cell line" capable of continuous propagation was established from a calf kidney tissue. The bovine adenovirus type 3 could propagate well in this cell line.

The control mechanism of mitosis in the regenerating rat liver was studied in relation to the cell functions. Partial hepatec· tomy induces a series of changes prior to the initiation of mitosis, i. e. decrease in serum glucose and albumin levels, loss of glycogen from liver cells, and increased lipid mobilization to liver cells. Massive supplies of glucose and fructose suppressed significantly hepatocellu. lar mitosis with suppression of lipid accumulation and preservation of glycogen in the liver cells and of blood sugar level. Homologous serum administration also suppressed the rate of liver cell mitosis after hepatectomy preventing the decrease in serum albumin level, but did not suppress the lipid accumulation in the liver. Starvation, which would relieve the liver cell from the work of detoxication of intesti. nal toxic products, did not show any suppressive effect on the mitotic rate of liver cells after partial hepatectomy in single animals. But starvation induced severe hypoglycemia, moderate hypoalbuminemia and loss of glycogen content in the liver. These changes in metabo. lism by starvation and partial hepatectomy were suppressed by con· jugating the animals with nonhepatectomized fed.partners by aortic anastomosis, and mitosis was suppressed in the residual liver of the fasting animals in this parabiosis. The results indicate that all the major functions of parenchymal live cells tested, sugar metabolism, serum albumin production, and detoxication, are closely related to the control of liver cell mitosis. Accumulation of lipids in the liver remnant after partial hepatectomy is thought to be for the compensa. tion of reduced glycogen storage and not concerned directly with the liver cell mitosis. Discussion was made briefly on the humoral factor and portal blood factor in relation to excess load of functions on resi. dual liver cells.

Folic acid contents of plasma, whole blood, liver and spleen in Rauscher leukemic mice were estimated. Plasma and liver folate in the leukemic mice was lower than that of normal mice, suggesting that folic acid was deficient in Rauscher leukemia. Folic acid contents in whole blood and spleen were even higher in the leukemic mice than those in normal mice. Clearance study by injecting folic acid intravenously into leukemic mice showed faster disappearance of folic acid from the circulating blood, suggesting that folic acid demand of Rauscher leukemia is increased. Methotrexate administered shortly after inoculation of the virus did not prevent Rauscher leukemia. But anemia, reticulocytosis and erythroblastosis, which are commonly seen 3-4 weeks later in leukemic controls, were not marked as compared with controls. It can be concluded that the requirement of folic acid is greater in Rauscher leukemia than in controls, and methotrexate is effective for preventing hematological changes commonly seen in this type of leukemias.

Effect of inorganic phosphate on ferrous ion- and ascorbate-induced lipid. peroxidations of isolated rat liver mitochondria was investigated. As a result it has been shown that phosphate accelerates the ferrous ion.induced lipid peroxidation; namely, phos. phate shortens the induction lag period of the lipid peroxidation reaction but the malondialdehyde after onset of its production is yielded at the same rate in various concentrations of phosphate. On the other hand, phosphate inhibits ascorbate.induced lipid peroxidation. There are stoichiometric interactions between the concentration of phos. phate and the induction period. Oxygen uptake by mitochondria was observed in the presence of both ferrous ion and phosphate at initial step of the reaction without being accompanied by malondialdehyde production, and afterwards there occurred malondialdehyde production with rapid rate of the oxygen uptake. Possible mechanisms and interactions among ferrous ion, ascorbate and phosphate were discussed.

Carcinogenic effect of N, N'-dimethylnitrosourea (DMNU) on mice and hamsters was studied. Repeated subcutaneous injections　of DMNU resulted in the induction of malignant lymphomas with an　incidence of 100 per cent in adult C3HjBifBjKi mice and induced　malignant tumors of　forestomach, mammary gland and uterus with a　high incidence in adult hamsters. Control animals showed no pathological　changes. Electron microscopy revealed the presence of murine　type C virus particles in some of the tissues examined. Many type C　virus particles were found in a transplant of DMNU.induced malig.　nant lymphoma. Some type C virus particles were shown in malignant　lymphomas and lymph nodes of malignant lymphoma-bearing mice.　A very small number of type C virus particles were observed in thymus　of control mice and bone marrow of a malignant lymphoma.bearing　mouse. A few particles, quite similar to murine type C virus particles,　were detected in　DMNU.induced mammary adenocarcinoma of hamster.　No virus-like particles were seen in mammary glands of control hamsters. Whether these particles are merely passengers or are playing　a significant role in the carcinogenesis of these tumors remains to　be determined.

Two fetus-specific globulins, al and a2·fetoglobulins, were detected in rat fetal serum, and the former was detected in amniotic fluid, using respective monospecific rabbit immune sera. Immunochemical distinction of these two proteins was demonstrated. By polyacrylamide gel disc electrophoresis, al-fetoglobulin was further resolved into fast and slow migrating subcomponents having a similar reactivity against the specific immune serum. The concentrations of these globulins in the serum of adult rat with experimentally induced hepatic lesions were determined by quantitative immunoprecipitin method or the Ouchterlony test using the specific antisera.

As the method for the diagnosis of metastasis of breast cancer to internal mammary nodes, 198Au colloid was used in parasternal scintigram. In the internal mammary nodes, the rate of correct diagnosis was 90% in the cases where diagnosis of positive metastasis was obtained, 44. 5% in whom metastasis was suspected, and 100% in whom diagnosis of negative metastasis was made. In the subclavian nodes, corresponding values were 69.0%, 34.5%, and 100% indicating poorer diagnostic rate. Examination on the relationship between metastasis to the lymph nodes and scintigram revealed more intense spots in the lymph nodes with very small metastasis than on normal side. As the metastatic portion increases in size, spots become less intense until finally the spots are cold as the whole lymph nodes are occupied by the cancer tissue. As the site of the tumor not only the medial side but also lateral side are involved in Stage I in a high rate of lymph node metastasis. Need of complete removal of internal mammary nodes was urgently suggested.

By endolymphatic injection of radioisotope 131I.Lipiodol, so.called endolymphatic radiotherapy, we treated 10 cases with malignant lymphoma and found a marked tumor reduction to normal size in all the 10 cases we tried. It seems that this method is one of the most effective therapeutic methods for malignant lymphoma, espe. cially invading into the retroperitoneal lymph nodes.

Hematological changes and serum iron, vitamin B12 and folate levels after administration of iron plus folic acid were com· pared with changes and levels after supplement of iron alone in 100 pregnant women. No hematological benefits by adding folic acid was revealed. It is concluded that folic acid deficiency in pregnant women is mild and routine supplementation of folic acid is not necessary except for proved cases of folate deficiency. As to the reason why folic acid deficiency is so mild and megaloblastic anemia is so rare in Japan, uniformity of dietary habits, i. e. boiled rice as basic food, was discussed.

For the purpose to define the mechanism of heavy metal intoxication by inhalation, morphologic observations were made on rat lungs after nasal instillation of iron colloid particles of positive and negative electric charges. Histochemical observation was also made on the liver and spleen of these animals. The instilled iron colloid particles reach the alveolar cavity easily, as can be seen in the tissue sections stained by Prussian blue reaction. Alveolar macrophages do take up them avidly both of positive and negative charges, though much less the positive particles than negative ones. In contrast, the alveolar epithelial cells take up solely positive particles by phagocytosis but not negative ones. Electron microscope observation revealed that the positive particles are ingested by Type I epithelial cells by pinocytosis and by Type II cells by phagocytosis as well. Then the iron colloid particles are transferred into the basement membrane by exocytosis. Travelling through the basement membrane they are again taken up by capillary endothelial cells by phagocytosis. Some particles were found in the intercellular clefts of capillary endothelial cells but not any iron colloid particles in the intercellular spaces of epithelial cells and in the capillary lumen. However, the liver and spleen tissues of the animals given iron colloid showed a strong positive iron reaction. On the basis of these observations, the mechanism of acute intoxication by inhaling heavy metal dusts like lead fume is discussed from the view point of selective uptake of alveolar epithelial and capillary endothelial cells for the particles of the positive electric cha'rge.

Cultured rat liver cells which were cloned from a single cell were transformed into malignant cells by a chemical carcinogen, 4-dimethylaminoazobenzene (DAB). The DAB-transformed cells produced tumors when back-transplanted into new-born rats but the carcinogen-untreated control cells did not. Characteristics of the transformed liver cells were compared to those of DAB-untreated control cells in regard to the morphology, the consumption of DAB from the culture medium by the cells, the incorporation of 3H.DAB into the cells, and the aggregate.forming ability of the cells in rotation culture. The results showed that no significant parameter of malig. nant transformation in culture was detectable except the tumorigenicity of the transformed cells upon the inoculation into animals.

To clarify the ultrastructure of the extended ribosomal RNA molecules, electron microscopic observations were carried out on the RNA molecules extracted from purified ribosomes of mouse ascites sarcoma cells. By the treatment with ethylenediamine-tetraacetate agglomerated rRNA molecules were elongated to thread-like structure by partial unfolding. The lengths of thread-like molecules were measured as less than Iii. The strand of RNA molecules stained with uranyl acetate was observed approximately l5A in width.

To observe the possible role of cAMP on the DNA synthesis during specialization-division of myelogenous precursor cells, the authors observed the DNA and RNA synthesis of the cells by in vitro autoradiography. And it is concluded that cAMP or its dibutyryl derivative added to the media penetrated into myelogenous precursor cells and metamyelocytes of mice and enhanced the DNA synthetic capacity of them. cAMP hardly enhanced RNA synthesis. Discussion is made on relation between enhancement of DNA synthesis of metamyelocytes and their possible rejuvenation.

For predicting median date or incidence rate in the prevalence of japanese encephalitis, the authors considered the 34 factors; namely, the climate, latitude, longitude, and date showing immunological positivity of hemoagglutination inhibiting reaction on 50% the number of swine, etc. To make the mean square residual the smallest which yields, in the case of calculating with the multiple regression equation, the most important and meritorious factors were selected from the factors mentioned above by the voluntary selection rule devised by us. Multiple regression equations were formulated for them. To predict the median date in the prevalence of japanese encephalitis in whole japan, we found that the three factors, i. e. the amount of rainfall in April, the average temperature in March and HI positive rate of swine till the end of july, were essential. And for the foreseeing of incidence rate in Okayama Prefecture, factors concerning mosquitoes were added; this resulted in the useful two factors, namely, common logarithm of the total number of Culex tritaeniorhynchus till july 20th and the rainfall in June.

We examined the method for determining microquantities of lipids, including cholesterol, cholesteryl esters and phospholipids. A standard colorimetric procedure of cholesteryl esters was modified to accommodate a quantitative thin-layer chromatography. This method involved the following steps. (1) Separation of lipids by a thin-layer chromatography: Lipids were applied to Silica gel G plates. Plates were developed with petroleum ether-diethyl etheracetic acid (82: 18: 2, vIvIv). (2) Elution of cholesterol and its esters from scraped silica gel: After scraping the silica gel with adhered cholesterol and its esters, they were eluted with chloroform-methanol (4: 1, v,tv). In the case of phspholipids, the silica gel was calcified. (3) Colorimetric determination of the lipids: Cholesterol and its esters eluted from the silica gel were determined by the method of ZAK with ROSENTHAL'S color reagent directly and after saponification, respectively. Phospholipids were calculated from the phosphorous content determined by the method of KATES. On the basis of examination of recovery and analyses of lipids extracted from tissue, it was concluded that this method permitted a reliable estimation of microquantities of cholesterol, its esters and phospholipids from small amounts of biological materials.

T cell concerned with cell mediated immunity and B cell concerned with humoral antibody are classified by scanning electron microscopy of the surface structure of lymphocytes using E binding lymphocytes and EAC (sensitized sheep erythrocytes treated with complement) binding lymphocytes. For the purpose to elucidate morphological differences between T cell and B cell the scanning electron microscope observations were carried out with the blast forming lymphocytes incubated in the presence of PHA. As a result it has been demonstrated that T cells have short microvilli on the cell surface, but the reason for the difference in the number of the microvilli is unclarified. Even T cells have sometimes long microvilli in the younger stage, they are longer and more slender than those of untreated peripheral B cells.