Chiba sarcoma, a strain of the viral sarcoma of the chicken, produced in the chicken thymus by injection in loco of the causal agent, was studied by electron microscopy.
In some of the tumor cells examined 6 or 7 days after the injection some structures were seen containing a various number of virus particles and comparable to the gray bodies of Bonar et al. These structures were observed at all possible stages of their development-as mere gray bodies and as complicatedly indented spaces filled with virus particles, to mention their earliest and ultimate forms. The virus is likely to enter the gray body of the tumor cell by phagocytosis multiply within the body and, finally, to be discharged from the cell.

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Six cases of hydatidiform moles and three cases of normal chorionic villi were subjected to cytological study, particularly on the number and morphology of the chromosomes.
In all cases from the two sources considered, the modal number of chromosomes was found to be 46. The chromosomes were of a normal pattern in both number and morphology with either the female or male karyotypes. A considerable number of polyploid cells occurred in cell populations derived from hydatidiform moles, while in those from normal chorionic villi incidence of polyploidy was very low. Further, abnormal mitotic cells showing endoreduplication, clumping and scattering of the chromosomes were frequent in some mole specimens.

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An electron microscopic observation was made on the hyperplastic nodules in the mammary glands of mice. The animals were derived from three inbred strains (C3H/HeMs, SL, and A/Jax), 2 groups of hybrids (F₁ hybrid of the A/Jax×AKR cross, and F₄ hybrid of the A/Jax×BALB/c cross), and 3 colonies of non-inbred mice (Swiss, na2, and dd/s). A total of 9 animals were used, consisting of one female mammary tumor-bearing mouse from each of these 8 different sources and one tumor-free female SL mouse. Animals, either parous or estrogen-treated in the past, had a various incidence of mammary tumor, from extremely high to very low. All the nodules taken from these 9 mice invariably showed the virus-like particles of Type B (Bernhard), The particles were round or oval in shape, approximately 1000Å in diameter, and had an eccentrically located dense nucleoid. They were distributed extracellularly. Membrane-bounded proliferation of the particles was recognized at the tips of the microvilli or at the apical plasma membrane. Some nodules derived from mice of A/Jax strain and (A/Jax×AKR)F₁ hybrid had the intracytoplasmic Type A particles as well as the extracellular Type B particles. The possibility was considered that practically all hyperplastic nodules harbor the Type B particles irrespective of the mouse strains.
Besides the presence of the virus-like particles, the ultrastructure of the nodules retained all the characteristics of the glandular epithelium. The secretory mechanism was similar to that in the normal lactating glands. The fat droplets were released by a pinching-off mechanism and the protein particles through an opening at the cell surface.

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A microspectrophotometric study of the DNA content was undertaken in seven cases of gastric carcinoma in comparison with the normal stomach epithelial tissue. The results are summarized in Fig. 1 and Table I. The cells of the normal epithelial tissue showed the DNA content in basic value-2n with a limited degree of variation from cell to cell. Carcinoma cells showed a much larger scatter in distribution of DNA values from cell to cell than the normal cells and four out of seven cases showed DNA values lying around a triploid range. Generally, the DNA content of gastric carcinomas here considered tends to correspond to the stem-line chromosome number of these tumors.

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1) The serum properdin level was determined in a total of 133 cases of normal subjects, patients with malignant neoplasms, and other pathological conditions using the phage neutralization technique. i) The distribution and range of the PhN₅₀ units in neoplastic patients are almost the same as in normal subjects. ii) There is on correlation between the slope values and the PhN₅₀ units in cancer serum. iii) The neutralizing activity of a given serum against T3 phage is always higher than that against T2 phage without a constant ratio between the two. iv) In limited number of cancer patients, the PhN₅₀ units and serum γ-globulin show a tendency to have negative correlation. v) No correlation can be established in cancer serum between the PhN₅₀ units and the positive reaction to C-reactive protein antiserum, vi) The administration of a large dose of Mitomycin-C during a few days for the treatment of cancer results in a rapid fall in the PhN₅₀ unit. A medium dose of the drug given once a week hardly shows such an ill effect.
2) The phage and modified zymosan assays were compared in a few cases of cancer along with the treatment. No parallelism can be found between the properdin units obtained by the phage and zymosan assay methods.
3) The relationship of properdin and the phage neutralizing capacity of a serum has been discussed in relation to the possible role of these factors in tumor immunity.

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In the previous paper, it was shown that if Ehrlich ascites tumor cells are brought into contact with the normal human serum, typical cytolysis (oncolysis) results. For this oncolysis three factors (heat-stable and heat-labile factors and Mg²⁺) are necessary. In this paper, the nature of the heat-labile factor was discussed with special reference to its difference from complement. Following conclusions are drawn.
1) On heating, treating with zymosan, with specific antigen-antibody complexes, or with ammonium chloride, the activity of heat-labile factor in the oncolysis and that of the hemolytic complement disappear simultaneously.
2) In oncolysis, too, consumption of complement, especially that of the endpiece, and the third and fourth components of complement can be demonstrated.
3) Even in the sera, in which the heat-labile factor is completely consumed by oncolysis or inactivated by dialysis against distilled water, the hemolytic activity is still preserved.
4) For oncolysis, besides the four components of complement, another substance is necessary. This substance is heat-labile, inactivated by dialysis against distilled water, and is contained in the serum fraction precipitated by ammonium sulfate at the concentration of 1.39-2.0M.
5) Properdin has no relation to oncolysis in the present sense.

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(1) Chromatographic analysis of tryptic hydrolysate of cancer albumin suggests the possible mechanism of the tumor tissue taking up the specific peptide constituent from albumin molecule and synthesizing the same peptide and putting it into albumin molecule.
(2) The serum albumin obtained from a cancer patient has the characteristic antigen which is able to produce, in 50% of the cases, anaphylactic contraction of the intestinal strip of a rat immunized by cancer albumin.
(3) The structural change produced during the time between the entry of albumin into the tumor and the leaving from it might give the cancer albumin antigenicity different from the normal albumin.

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6-Chloro-4-nitroquinoline 1-oxide was demonstrated to possess a very powerful carcinogenic action. Applied to the rat skin two times a week, the substance in 0.5% acetone solution produced malignant tumors which were histologically fibrosarcoma (12 cases), fibrosarcoma associated with basal cell carcinoma (5 cases), and fibrosarcoma associated with sweat gland adenoma (1 case). Metastases were found in a few cases but transplantation was not attempted.
6-Chloro-4-nitroquinoline 1-oxide is apparently a more powerful carcinogen than 4-nitroquinoline 1-oxide and this fact was discussed in relation to the theory that substitution of a nitro group at 4-position with thiol compounds may be the essential chemical reaction which determines the carcinogenic activity of these related derivatives.

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Conditions for the quantitative determination of ubiquinone in normal rat liver, hepatomas, and fibrosarcomaw ere investigated. For the crude extract of ubiquinone with petroleum ether, the colorimetric assay was found to be appropriate. For the purified ubiquinone fraction from alumina column chromatography, colorimetric and spectrophotometric assays gave satisfactory results.
The ubiquinone content of hepatoma and sarcoma was one-third to one-tenth of that of the normal rat liver. Ubiquinone concentration in mitochondria of sarcoma, on a per mg nitrogen basis, also showed a lower value than that of the normal liver. Hepatoma AH-49 and sarcoma contain UQ₉ as the sole ubiquinone.

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1) Mouse liver catalase was inhibited by 3-amino-1, 2, 4-triazole, allylisopropylacetamide (AIA), and allylisopropylacetylcarbamide (AIC) just as in the rat, the effective doses being proportional to the body weight.
2) The rate of destruction (k_D) of mouse liver catalase lies around 0.020 with 3-amino-1, 2, 4-triazole, AIA, and AIC alike.
3) Continued administration of toxohormone did not decrease the level of catalase activity progressively as in the case of AIA or AIC, and this activity remained at a certain low level (around 70% of the control). Several possibilities to account for this phenomenon are discussed.
4) Whether the liver catalase depression by toxohormone is due to the increased rate of its destruction or the decreased rate of its synthesis was analysed with the aids of 3-amino-1, 2, 4-triazole, AIA, and AIC.
It is substantiated from various experiments that the depression of liver catalase by toxohormone injection is mainly due to the decreased rate of its synthesis.

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