Organs Of Normal Mice Research Articles

Methylation of DNA in vitro: Enzymic activity from different bacterial strains on DNA from various sources

1. DNA-methylase activity from Escherichia coli strains KB, B and W and from Azotobacter was tested using DNA acceptors from bacteria, mouse organs and tumors, and polyoma virus. DNA substrates could be distinguished with regard to species and strain specificity by their rate and extent of methylation and by the ratio of incorporation into 5-methylcytosine as compared with 6-methylaminopurine. Under the same conditions, DNA samples from normal mouse organs and from mouse tumors showed no significant differences when methylated by bacterial DNA methylases. 2. Polyoma virus DNA was enzymically methylated in vitro, and tested for infectivity. It showed the same plaque-forming ability as the normally occurring non-methylated polyoma DNA. 3. Heparin (as well as polylysine) was found to inhibit nucleic acid methylase activity when present at a final concentration of 1 μM or greater. 4. Ethylation of DNA was observed using S-adenosyl [ Et- 14C]ethionine as a source of ethyl groups.

Immunological hystochemical characteristics of one of the organ-specific antigens of mouse liver

A method is described for obtaining monospecific antibodies to one of the organ-specific antigens of mouse liver. With the aid of these antibodies the antigen content of the liver and of normal mouse organs was determined by means of double diffusion in gel. The fluorescent antibody method was used to locate, this antigen in the cytoplasmic granules of hepatic parenchyrna cells.

Anti-Pasteurella Pestis Factor in the Organs of Normal Mice and Guinea Pigs

Summary The preparation from several organs of normal mice and guinea pigs of an anti-Pasteurella pestis factor (APF), active in vitro, is described. The APF was active in varying degrees for several strains of P. pestis and for Micrococcus lysodeikticus but not for several other Gram positive or negative bacteria. Crude and purified APF from mouse liver and crude APF from mouse and guinea pig spleen and kidney were active following storage at -20°C. On the other hand, the activity of both crude and purified guinea pig liver APF was lost during storage at -20°C, but could be restored by heating at 60 or 65°C but not higher. Evidence is presented for the nonidentity of APF with previously described antibacterial substances such as basic polypeptides, histone, spermine, phagocytin and lysozyme. The evidence consists chiefly of dissimilarity in method of preparation and of the differential action of extraneous materials on the activity. One dose of APF administered at the time of inoculation with P. pestis did not protect mice from infection, and the virulence of P. pestis for mice was not altered by preliminary treatment of the organisms with APF in vitro.

Agglutinating action of heat-inactivated passage A mouse leukemia filtrates on mouse red blood cells.

1) Heated (55°C 1/2 hr) passage A leukemic filtrates had an agglutinating effect on mouse erythrocytes in dilutions up to 1:160, occasionally higher. Fresh filtrates did not agglutinate. 2) Agglutinin could be separated from leukemic agent by ultracentrifugation. 3) Tests were done at +40°C but could also be carried out at room temperature; the agglutinin did not elute. 4) Heated (55°C 1/2 hr) filtrates from spontaneous Ak leukemias agglutinated only in some instances, and in higher concentrations. Whether the agglutinating potency of some Ak leukemic filtrates is related to their ability to induce leukemia, remains to be determined. 5) Fresh or heated filtrates from pooled normal mouse organs agglutinated only in some instances, and in higher concentrations. 6) The agglutinating potency of heated leukemic passage A filtrates could be inhibited by specific rabbit immune serum to 1:128 dilution. Normal rabbit serum had an inhibiting effect only in 1:4 to 1:16 dilutions.

The effect of whole-body x irradiation on the bactericidal activity of pagocytic cells. II. Survival of Pseudomonas aeruginosa within livers and spleens of mice.

Mice irradiated five days previously with doses of 0, with Pseudomonas aeruginosa. Immediately thereafter, aa antibiotic was also injected intravenously to kill extracellular bacteria. Livers and spleens were removed from the infected mice 0, 4, and 24 hours later, ground, and the total numbers of viable bacteria determined by culture methods. The results indicate that the bacteria survived and multiplied within the spleens and livers of mice receiving 500 to 700 r X radiation but were destroyed in the organs of normal mice and mice receiving the lower doses of X irradiation (100 to 300 r). In mice previously immunized with killed Pseudomonas the bacteria did not survive within the livers and spleens even though the animals were subjected to 500 to 700 r. (auth)

Effects of various immune rabbit serums on the cells of several transplanted mouse lymphomas in vitro and in vivo; with special reference to inhibition by an antibody that reacts with neoplastic and non-neoplastic lymphocytic cells of mice.

Immune serums prepared in rabbits with antigens made from normal mouse organs and tissues that were presumably devoid of large numbers of lymphocytic cells (notably kidney, liver, brain, whole embryos, and erythrocytes) proved lethal for the cells of several transplanted mouse lymphomas in vitro in the presence of complement; but these immune serums, when given intraperitoneally in large amounts to susceptible mice that had been implanted subcutaneously with lymphoma cells of one or another of several types, failed entirely to inhibit growth of the lymphoma cells in vivo. In contrast, immune serums made with cells procured from transplanted mouse lymphomas as antigens, and those made with cells from normal mouse thymus or lymph nodes, acted even more powerfully upon the several types of lymphoma cells in vitro than did the immune serums prepared with normal mouse organs, and when given intraperitoneally to implanted mice they brought about death of the lymphoma cells in vivo, the effect being to a considerable extent specific and referable to an antibody that reacts with neoplastic and non-neoplastic lymphocytic cells of mice, as absorption experiments disclosed. In comparative tests, furthermore, the anti-lymphoma serums acted more powerfully upon the lymphoma cells in vivo than did such chemotherapeutic agents as amethopterin, azaguanine, ethionine, azaserine, and 6-mercaptopurine, given singly or in various combinations in maximal tolerated amounts, though their effects were not so powerful as those exerted by normal guinea pig serum on lymphoma cells of two types that are susceptible to its action in vivo. The significance of the findings was briefly discussed.

In vitro catalase-inhibiting action of tumor extracts and normal tissue extracts

The question of the « in vivo » inhibition of catalase by tumor extracts (Kochsaft), has been examined. Two experimental tumors, Sarcoma 180 and a spontaneous mammary adenocarcinoma of mouse, several organs of normal and tumor-bearing mice, several human tumors, namely gastric carcinoma and their corresponding mucosa, gastric mucosa of patients with ulcer, were investigated. A comparison between the simple « Kochsaft » and the extracts purified by alcoholic precipitation has also been performed, but showed no essential differences. The inhibition curves given by increasing amounts of tumor extracts lead us to suggest the presence of an activator beside the catalase inhibitor.

Distribution of radioactive colchicine in some organs of normal and tumor-bearing mice.

Summary1. Labelled colchicine was detected only in some organs of normal and tumor-bearing mice. 2. The uptake of colchicine in sarcoma 180 is as high as the uptake of liver. 3. Spleen is one of the organs having the highest concentration of colchicine in normal mice. 4. It was found that there was no colchicine in the spleen of tumor-bearing mice.

The Inhibition of Gdvii Virus Haemagglutination by Normal Tissue Extracts

Summary Saline extracts of normal mouse organs were capable, to a variable degree, of inhibiting haemagglutination by the GDVII virus. Of the tissues examined, sera from the mouse, rat, guinea pig and rabbit showed this property to the greatest extent. In resistance to heat and certain other agents the GDVII inhibitor in normal mouse brain suspensions differed slightly from the corresponding factor in serum. Other studies on the distribution of inhibitor showed the concentration in foetal mouse brains to be comparable with that in adult tissue. Removal of viral haemagglutinins from the brains of mice experimentally infected with the GDVII strain did not affect the titre of the inhibitory agent. A crude fractionation procedure applied to normal mouse brains showed the bulk of inhibitor to be present in saline extracts of lipid-free tissue. The material was concentrated from these fractions by 50% saturation with ammonium sulphate at pH 7.0. Little activity was exhibited by the lipid residues. A limited number of neutralization tests in mice showed the above extracts to be incapable of inactivating GDVII virus.