Atrophic gastritis: a possible pre-cancerous condition.

Mass screening in cancer control.

Host-tumor relationship XXXIII. Inhibitor of hyaluronidase in blood serum of cancer patients.

Inhibiting activity of blood serum was determined from the decrease of N-acetyl-hexosamine end groups of hyaluronic acid products released by testicular hyaluronidase. Maximum inhibition was observed within the region of pH from 6.5 to 6.8. Correlation between the serum concentration and its inhibiting effect on hyaluronidase was found within the range of the final dilution of serum (in the reaction mixture) from 9 to 45 X. Blood sera of cancer patients showed statistically significant increase of hyaluronidase inhibitor as compared with that of health people.

Possible association of oncornavirus type D with some forms of human cancer.

The method of molecular hybridization of nucleic acids of oncornavirus type D produced by HEp2 cells with cellular nucleic acids was applied. No sequences homologous to the viral nucleic acids were found in normal human embryo cells as well as in bovine, porcine, murine, and chicken cells. No such sequences were found in tissues of malignant lymphomas. Sequences homologous to the viral nucleic acids were found in some cancer cells, predominantly in hormone-associated tumors of females.

Molecular hybridization study of cells producing oncornaviruses type D.

Five human cell lines producing oncornaviruses type D were studied by the method of molecular hybridization of viral and cellular nucleic acids. Repeated sequences of viral genome equivalents were found in nuclear DNA and numerous copies of viral genome were found in the cytoplasm. The viruses produced by the cell lines were found to be identical or closely related as regards nucleotide sequences of their genomes.

Visceral radioisotopic lymphography of the testicle.

Scintigraphic studies made in 75 patients, respectively on 130 testicles with the aid of the organ radio-isotopic lymphography enabled to determine more exactly the location and the variety of the testicular lymph centers. It should be pointed out that in 58.5% of the patients the lymph centers are situated on the left of the middle line and only in 6.1% on the right. In some cases iliac lymph nodes were demonstrable. Attempts were made to use this method in investigation of the patients with malignant tumours of the testicles.

Mouse MSV transformed cells resistant to 8-azaguanine.

Mouse cells transformed by murine sarcoma virus were made resistant to 8-azaguanine. Resistant cells and cell clones isolated from them were deficient in hypoxanthine-guanine phosphoribosyl transferase (HGPRT) activity. They did not grow in HATG medium, did not incorporate labeled hypoxanthine, and had negligible HGPRT activity. The resistance was genetically stable. The resistant cells were hyperdiploid and contained telocentric chromosomes only. The resistant cells as well as the progenitor cells were slightly tumorigenic in mice, the plating efficiency in soft agar was very low. The parental cells and aza-G resistant cells produced C-type viral particles having RNA-dependent DNA polymerase activity. The resistance to aza-G did not influenced the expression of murine sarcoma virus genome in cells. The resistant cells are suitable for preparation of cell hybrids.

Transformation of BHK 21/13 cells by chemical carcinogens and mutagens.

In vitro transformation of BHK 21/13 cells by chemical carcinogens is reported. The hamster cells were treated with MCA, BP, 4-NQO and 5-azaCR at various concentration and duration of treatment. The morphological, karyological and growth characteristics of cell lines were investigated. Search for RNA tumor viruses in transformed cells using 3H-uridine labeling, detection of DNA polymerases, electron microscopy investigations failed to detect presence of C-type virus particles.

Polypeptides isolated from ribosome-like structures occluded in avian myeloblastosis virus (AMV).

The protein composititon of ribosome-like particles isolated from AMV was determined by acrylamide gel electrophoresis and by immunological methods. It was established that the protein spectrum of ribosome-like particles differed significantly form the total protein spectrum of AMV. The most characteristic protein components of ribosome-like particles had a molecular weight in the range of 70 000--110 000. Apart from these proteins, the viral ribosomal particles contained a small amount of proteins with a molecular weight of 14 000--35 000 that could not be removed even by extensive purification. Immunological studies of the proteins of ribosome-like particles revealed the presence of antigenic determinants of ribosomal proteins. Furthermore, throughout the purification procedure the material contained components that reacted with antibodies against gs antigens.

Mammalian tropism of B77(RBI) virus. Expression of virus genome in the hamster sarcoma cell clones.

In contrast to the B77 virus, its B77(RBI) rat variant continuously produced by the rat RBI sarcoma cells in vivo and in vitro, efficiently induced progressively growing tumors in hamsters and transformed hamster embryo cells in vitro. Both, induced tumors and transformed cell cultures showed production of infectious virus and presence of the avian gs-antigen. Clonal analysis of the established hamster sarcoma cell line RBHtc brought evidence that despite the quantitative differences in the virus production and gs-antigen content among various clonal populations, full expression of the B77(RBI) virus genome does occur in each cell of the virus-induced hamster sarcoma. The permissive relationship of the B77(RBI) virus with rat and hamster cells as well as changed antigenic composititon implies that a genetic change of the virus occured, which is reflected in its increased mammalian tropism and its genetically stable firus-productive interaction with mammalian cells. The possible explanations of these phenomena are discussed.

The experience with clinical application of hydron pouches in tumor chemotherapy.

Hydron pouches were applied in three cases of embryonal hepatomas in infants. Cyclophosphamide (one case) and methotrexate (two cases) were used for filling of pouches in order to accomplish local chemotherapeutical effect directly on the tumor. Histopathological examination showed good compatibility of pouches to the liver tissue. No therapeutical effect was observed in a set of experiments due to a small size of pouches as compared to big masses of tumor. Some suggestions for further development of this method are presented.

DNA content of mouse hepatoma nuclei determined by Feulgen cytophotometry.

The DNA content of mouse hepatoma nuclei was determined by means of Feulgen cytophotometry. The tumor nuclei showed a wide range of polyploidy and aneuploidy characteristic of malignant cells.

Neoplastic transformation of mouse embryo cells by virus released from tumorigenic mouse cells transformed by avian sarcoma virus B77.

Mouse C3H embryo cells were transformed in vitro by avian sarcoma virus Bratislava 77 (B77) released scantily from a mouse cell line transformed earlier by the same virus. B77 virus transformed C3H embryo cells contained B77 viral genome and were transplantable into syngeneic as well as allogeneic DBA/2J young mice in which autochthonous sarcomas were induced. Tumors in both strains of mice were virogenic. The probable reasons for an increased transformation capacity of B77 virus in mammals are discussed.

Viruses harboured in blasts of the rat myelogenous leukemia (RBA-Le), induced by chicken sarcoma virus.

It was shown that the rat myelogenous leukemia RBA-Le harbours three kinds of viruses. 1. Rat leukemogenic virus, which can be recovered from leukemic cells, medium of cultured leukemic cells and the plasma of leukemic rats. About 12% of rats inoculated when newborn with the recovered virus developed leukemia. 2. Chicken sarcoma virus, which seems to have a lowered infectivity or altered host range as the B77(RBI) virus by which this leukemia had been induced. 3. A cytopathic, hemagglutinating virus, very pathogenic for baby rats, which was shown to be closely related, if not identical in biological as well as immunological properties with Kilham rat virus. The RBA-Le leukemic cells were adapted for growth in tissue culture.

Follow-up of certain immunologic indicators in the treatment of plasmacytoma with cyclophosphamide in combination with plasmapheresis.

Changes in the immunoglobulin and complement levels in untreated plasmacytoma were compared with those resulting from massive doses of Cyclophosphamide (15--25 mg per kg b. w. at intervals of 10--14 days) applied in combination with double plasmapheresis (involving removal of about 500 ml of plasma). A follow-up of the levels of normal immunoglobulins, paraprotein, total complement and the C3 component revealed a significant decline in the total complement following each single application of this treatment, but the decrease in C3 was nonsignificant. A decline of about 20% in immunoglobulins and of about 15% in paraprotein was observed in relation to the pretreatment values, but only that in the IgM class proved to be of statistical significance. The decrease in proteins was also established with the methods of total protein determination (refractometric or biuret methods) and was found to amount to 1000--3000 mg% after each dose of Cyclophosphamide with plasmapheresis. In the author's view, a combined Cyclophosphamide-plasmapheresis treatment is effective for achieving clinical remission. It should, however, be kept in mind that the effect of protein and paraprotein depression persists for only a few days, hence, to achieve long-term results, this treatment should be repeated in 2--3 week's cycles. The lowered values of humoral immunity indicators do not increase the danger of complications from a clinical aspect, when suitable preventive measures are taken.

Immunologic study of antigens and molecular hybridization of nucleic acids from milk of breast cancer patients.

Comparative study has shown that by the gel diffusion assay both anti-HEp-2 virus serum and anti-breast cancer milk ultrasediment serum precipitated an identical antigen in human milk specimens, which was not identical with the group specific antigen of the HEp-2 virus. At the same time tha anti-breast cancer milk serum did not precipitate the HEp-2 virus. However, molecular hybridization experiments revealed nucleotide sequences homologous to nucleic acids of oncornavirus of D-type in milk obtained from breast carcinoma patients as well as in milk of healthy donors.

Blastic leukemias affecting mammary glands.

Two clinical cases of blastic leukemia with tumorous infiltration of mammary gland are presented. Literature data and diagnostic problems of this type complication are discussed.

Aspects of the biochemical pharmacology of cytembena.

Cytembena, at low concentrations, caused an inhibition of the in vitro growth of L1210 mouse leukaemia cells which could not be reversed by reduced folates, purines, amino acids or deoxyribonucleosides. Invitro experiments with a number of enzymes of folate metabolism produced no evidence that this drug acts as an anti-folate in mammalian tumor colls. However, Cytembena, in therapeutic doses, caused a rapid and extensive inhibition of DNA biosynthesis. There was no inhibition of RNA biosynthesis, but at high doses some inhibition of protein biosynthesis was observed. Deoxyribonucleoside triphosphates accumulated in the presence of Cytembena, suggesting that the inhibition of DNA biosynthesis was at the polymerization stage. However, in vitro experiments failed to demonstrate any direct interaction of Cytmebena with either DNA or DNA polymerase.

Change in the proportion of T and B lymphocytes in human malignant neoplasia in relation to the clinical stage.

Formation of spontaneous (E--erythrocyte) and immune (EAC--erythrocyte, antibody, complement) rosettes of sheep red blood cells (SRBC) with peripheral blood T and B lymphocytes, respectively, was used for quantitative assessment of these lymphocytes populations in tumor patients and control subjects. Relative counts of T and B lymphocytes have been correlated with lymphocyte survival in short-term cultures using standard subtoxic doses of phytohemagglutinin (PHA). The mean values and SE in normal control subjects for E rosettes (T lymphocytes) were 72.8 +/- 1.2%, for EAC rosettes (B lymphocytes) 23.8 +/- 2.5% of lymphocyte population. The survival of lymphocytes in short-term cultures with PHA in control subjects was 55.3 +/- 1.1%. In tumor patients the counts of E, EAC rosettes and percentage of lymphocyte survival in short-term PHA cultures were dependent upon the clinical stage. In patients with localized tumors the values were similar to controls. In patients where dissemination of the tumorous process could be ascertained a decrease of T lymphocyte counts, an increase of B lymphocyte counts and a higher survival of peripheral blood lymphocytes in short-term cultures with PHA was found.

Migration inhibition of peritoneal cells and PHA lymphocyte toxicity in rats during methylcholanthrene carcinogenesis.

Peritoneal exudate cells obtained from rats bearing primary methylcholanthrene-induced tumors were shown to be inhibited in their capillary tube migration capacity as compared to cells from nontreated control litter-mates. The survival of rat peripheral blood lymphocytes harvested from the same individuals were tested simultaneously in short-term cultures with a standard concentration of Phytohemagglutinin. Lymphocytes from tumor-bearing rats survived better than control lymphocytes in 24-hour cultures with Phytohemagglutinin. A correlation was found from a comparison of the results of these two methods. These findings are discussed with regard to the possibility of T cells depletion from peripheral lymphocyte population, together with the enrichment of this population with B cells in tumor-bearing individuals.

Characterization of thymus- and bone marrow-derived lymphocytes in rats by means of 3H-uridine incorporation.

Lymphocytes from various lymphoid organs and of the thoracic duct of normal and thymectomized rats, irradiated and reconstituted with syngeneic bone marrow were tested in vitro in a minimal non-enriched cultivation medium with 3H-uridine, and the percentage of uridine-labeled lymphocytes was determined. The highest number of heavily labeled small lymphocytes was found in the thymus and the thoracic duct, less in peripheral blood, the lymph nodes and the spleen, and the smallest numbers in the bone marrow. A reduced ability of uridine uptake was noted in the thymectomized animals. The method of immune rosette formation was used to determine the presence of B lymphocytes in the lymphoid rat population. The highest quantity of B lymphocytes was noted in bone marrow and the least in the thymus and the thoracic duct. Thymectomized animals had a significantly higher percentage of EAC rosettes than normal and sham-operated animals. The methods employed and existing literary data enabled us to identify the heavily uridine-labeled lymphocytes as T cells, while unlabeled lymphocytes are considered to be B cells. The difference in uriding uptake by rat lymphocytes may serve as one of the T lymphocyte markers in a heterologous lymphoid population.

Trichlortriethylamine (TS-160 Spofa) in combination chemotherapy of malignant lymphomas.

Thirteen patients with disseminated malignant lymphomas were treated with combination chemotherapy which included trichlortriethyl amine (TS-160), vincristine (Oncovin), procarbazine hydrochloride (Natulan) and prednisone. All patients but two received some form of chemotherapy and/or radiotherapy prior to being started on four-drug regimen. Good response to the combination chemotherapy was recorded in 84% of patients, while complete remission was achieved in 23% of cases. Drug toxicity has not proved to be a major problem in the combination used. Nausea and vomiting were the side effects the most frequently observed.

Comparison of the effect of nalidixic acid and thymine deprivation on excision repair in Escherichia coli.

There is a difference in the extent of inhibition of thymine dimers (TT) excision in ultravioley (UV) irradiated cells of E. coli after preirradiation depression of protein and DNA syntheses induced by a simultaneous deprivation of essential amino acids (AA-) and thymine(T-) or by deprivation of essential amino acids and addition of nalidixie acid (NAL+). This difference has been noted in both E. coli B/r Her+ and E. coli K12 SR20 uvr+ cells. Depression of DNA synthesis with the aid of malidixic acid as exogenous agent will inhibit TT excision to a lesser degree than depression of DNA synthesis by thymine starvation. The extent of TT excision has no appreciable influence on restoration of the sedimentation profile of newly synthesized DNA nor again on UV resistance of cells in conditions of dark repair. At the time when there are TT still present in DNA, the DNA molecule, having the size of the molecule of unirradiated cells, will become synthesized.

Changes in stored and short-term cultures of mouse bone marrow cells.

Changes in cells of mouse bone marrow cultured for 6--24 hr were followed both when fresh, and after storage for 3 to 5 days at a temperature of +2 to +4 degrees C. Considerable alterations were observed in the morphology, activity and transformation of these cells both during the storage period and the subsequent culture. Phagocyte ability was also detected in these cultures.

Sixieth anniversary of Professor Jaroslav Svejda.

Therapeutic effect of a water-salt extract from BCG in two patients with advanced breast cancer.

Two cases of advanced breast cancer treated with a water-salt extract from BCG are presented, showing a positive response -- marked and durable regression of the breast tumor and of the axillar metastases, parallel in the second case with a disappearance of lung metastases.

Nonspecific resistance to tumor allograft.

The effects of an increased volume of reticulohistiocyte system and macrophage activation in the recipient after treatment with BCG and Zymosan on the course of antitumor concomitant allograft-immunity reaction were studied. The results were verified on animals affected with immunosuppression due to whole body irradiation. A factor of essential significance for resistance to tumor allograft is an increase of the total number of small lymphocytes supplied by the transplantation of syngeneic spleen cells. A substantially lower efficiency was shown by prophylactic administration of BCG and Zymosan. Transplantation of macrophages syngeneic to the host failed to affect the latter's resistance to subsequent tumor allograft. The irradiated host's reactivity was regenerated with a suspesion of spleen cells of purified small lymphocytes, but transplantation of syngeneic macrophages remained without effect.

Lowering of the tumoricide activity of human serum with Varidase. II. Antibodies against Varidase in human serum measured by complement binding.

Active human serum manifests a tumoricide effect against cells of the Ehrlich ascites tumor. Sera of patients with Ca ventriculi show a higher effect than those of patients with a chronic streptococcal disorder, in comparison with intact subjects. This tumorcide effect is depressed by Varidase, the degree of depression being greatest in the group of patients with streptococcal infection, smaller in healthy subjects and least in carcinoma patients. The investigated sera contained antibodies against Varidase, but not against streptokinase. The anti-Varidase antibodies are found also in sera of the new-born children. The decline of the tumoricide activity of Varidase-treated sera is related to the quantity of anti-Varidase antibodies determined by complement fixing reaction in non-treated sera.

Evaluation of the usefulness of nitroblue tetrazolium reduction test (NBT test) for detection of bacterial infection in cancer patients.

False positivity of the NBT test in neoplastic diseases described by some authose may be a limitation in the use of the test for infection screening in cancer patients. For explaining this problem studies were performed in a group of 30 patients with various untreated malignancies without infection and in 20 of these with bacteriologically confirmed infections. The obtained results were compared with those in groups of normal persons without and with infection. Slightly modified Park method for spontaneous and stimulated NBT test was used. No significant differences between patients of both groups without infection were found. The increase in positivity of the test in presence of infection was lower in cancer patients than in normal subjects, however, it was non-significant. We did not observe any false-positive results in our patients, though one case of false negativity in myeloma is described separately. It is concluded that neoplastic disease does not cause, as such positivity of the NBT test. Because of similar response of NBT test to presence of infection, the NBT test is recognized as very useful for infection screening in cancer patients similarly as in normal persons.

Function of the UVR marker in dark repair of DNA molecules.

It had been found earlier that the excision repair mechanism in E. coli B/R Hcr+ could be depressed by preirradiation, amino acid and thymine starvation; such an interference proved to have no appreciable influence on survival after ultraviolet irradiation. A comparison between Hcr+ and Hcr- cells had revealed that the former were capable of tolerating a greater amount of unexcised dimers than the latter. In this paper it is demonstrated that the above-mentioned pretreatment will depress excision activity also in cultures of E. coli K12 and E. coli 15T- both strains of the uvr+ rec+ genotype. A comparison of two E. coli K12 strains of the uvr+ and uvr- genotype shows that uvr+ cells also have a greater capacity to tolerate unexcised dimers. To throw light on the nature of that increased capacity to tolerate unexicsed dimers we have compared restoration of DNA daughter chains in cells of the uvr+ and uvr- genotype and found that integrity of uvr loci is a conditio sine qua non for an effective restoration of daughter chains, but that depression of excision activity by the mentioned pretreatment does not influence restoration of DNA daughter chains. This suggest that uvr loci are involved not only in excision but also in postreplication mechanism of DNA repair.