bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantification of mouse mammary tumor virus structural proteins in hormone‐induced mammary tumors of low mammary tumor mouse strains
Authors: Nüsse R. , Michalides R. , Boot L. M. , Röpcke G. 
Published: February 2007

AbstractThe expression of the mouse mammary tumor virus (MMTV) in hormone‐induced mammary tumors was investigated by means of a radioimmunoassay for two major MMTV proteins, gp52 and p27. MMTV proteins were isolated on lectin affinity‐ and ion‐exchange chromatography columns. The purified viral proteins were electrophoretically homogeneous and retained immunoreactivity after labelling with 125iodine. Standard competition assays showed that group‐specific antigenic determinants were reacting. Mammary tumors were induced in three strains of mice with a low natural incidence of mammary tumors, C57BL, 020 and C3Hf, by a combined hormone treatment, consisting of hypophyseal isografts and administration of progesterone and estrone. Mammary tumors and mammary glands of hormone‐treated animals were extracted and used for competition radioimmunoassays. In general, the tumorigenic hormone treatment resulted in enhanced amounts of MMTV proteins in the mammary glands, compared to the amounts found in lactating mammary glands of untreated animals. The levels of MMTV proteins in the mammary tumors were lower than in the mammary glands.
Surgical adjuvant chemotherapy of metastatic murine osteosarcoma
Authors: Hiramoto R. N. , Ghanta V. K. 
Published: February 2007

AbstractA C3H murine osteosarcoma was used to investigate the effects of surgical adjuvant chemotherapy and to establish the relationship between primary tumor size and the number of metastatic lung tumor foci. The transplanted primary tumor was allowed to grow for 28 or 33 days and the lungs were monitored for microscopic colonies. Animals whose tumors were left in situ had 6–124 and 32–338 colonies in the lungs at 28 and 33 days, respectively. When the primary tumor was excised on day 10 post implantation, metastatic tumor colonies on day 33 were reduced to 0–24 colonies. The results indicated that the longer the primary tumor was left in the host the greater was the number of tumor cells which seeded to the lungs. Early surgical (day 10) removal of the tumor gave better survival than late (day 20) surgical removal of the tumor. When cyclophosphamide chemotherapy was used with surgery, better survival (80 %) was seen. Cyclophosphamide alone did not improve survival over that seen for tumor‐bearing controls. Late surgery with adjuvant chemotheraphy increased survival time.
Positive correlation between in vitro NK activity and in vivo resistance towards AKR lymphoma cells
Authors: Riesenfeld Inger , Anders Örn  , Gidlund Magnus , Axberg Inger , Alm Gunnar V. , Wigzell Hans 
Published: February 2007

AbstractThe possible in vivo relevance of murine natural killer (NK) cells in resistance towards grafted lymphoma was analyzed. The system comprised two AKR T lymphomas having similar behavior as to growth patterns but significant differences in vitro with regard to susceptibility to NK‐cell‐mediated lysis. These tumor cells were grafted into (AKRxCBA)F1 hybrids which had been lethally irradiated and then protected with bone marrow of CBA or AKR origin. Some adult animals were thymectomized before irradiation. The F1 chimeras could be shown to be repopulated with donor cells at the level of peripheral white blood cells and displayed high or low NK levels if coming from CBA and AKR donors respectively. Thymectomy resulted in a significant increase in the final levels of NK activity in the recipients. The in vivo growth patterns of the two AKR lymphomas were in a strikingly positive manner correlated with the NK activities of the recipients. Thus, high NK activity in the recipients resulted in a significant increase in resistance towards the outgrowth of the NK‐sensitive AKR lymphoma but had only marginal impact on the relatively NK resistant lymphoma. This was true irrespective of whether or not the recipients were thymectomized before marrow reconstitution and in general the T‐deficient mice were thus more resistant towards tumor grafting than their non‐thymectomized counterparts. In all, the results would thus further suggest an important role for NK cells in mediating in vivo resistance towards NK‐susceptible tumors, and they fail to provide any evidence for T lymphocytes in tumor protection in the same system.
Patterns of gastro‐intestinal cancer in european migrants to Australia: The role of dietary change
Authors: McMichael A. J. , McCall M. G. , Hartshore J. M. , Woodings T. L. 
Published: February 2007

AbstractCancers of the stomach, pancreas, colon and rectum are increasingly regarded as being diet‐influenced. Migrants to Australia from England, Scotland, Ireland, Poland, Yugoslavia, Greece, and Italy have come from countries with varied dietary backgrounds and gastrointestinal cancer risks. Age‐standardized cancer death rates in migrants, by country of origin, sex, age, and duration of residence in Australia (≤16 years and >16 years), have been calculated for 1962–76, and compared with those of the Australian‐born population. All seven migrant source countries, in 1970, had higher rates of stomach cancer than Australia, and the corresponding migrants groups, which initially reflected those higher rates, experienced an approximately 25% risk reduction with increased duration of residence. For cancer of the pancreas, migrants initially had rates well above their “native” rates; with longer stay, the risks generally converged upon that of the Australian‐born population. The four “continental” (European) migrant groups, whose native risk of colon cancer is about half that of the Australian population, showed an increased risk with increasing duration of stay. The increase was greater in men than in women, perhaps reflecting their greater dietary acculturation. By contrast, Scottish migrants, with an initially high risk of colon cancer, experienced a subsequent reduction in risk. Rectal cancer continental migrants showed even larger increases than colon cancer, while in British migrants there was a marked decline towards the “Australian‐born” risk. These various changes in cancer risk are discussed with reference to inter‐country dietary differences.
The plate‐implant as a bioassay for the neoplastic potential of cultured cells
Authors: Sanford Katherine K. , Boone Charles W. , Merwin Ruth M. , Jones Gary M. , Garrison Carlton U. 
Published: February 2007

AbstractOne objective of this study was to test the plate implant as an in vivo bioassay for the neoplastic state with pairs of cell lines that were non‐tumorigenic and tumorigenic when inoculated in suspension at various sites. Each pair originated from a common cell pool or from one cell derived from normal rat or mouse embryonic tissue. The implantation of cells attached to polycarbonate plates was compared with the subcutaneous injection of comparable numbers of cells in suspension or the intraocular injection of 105 cells. In addtiion, some implants of glass helices with attached cells were made into syngeneic mice and compared with injection of comparable cell numbers intramuscularly into X‐irradiated hosts. A total of 10 lines or clones were tested on plates. Of four lines that were non‐tumorigenic when inoculated in suspension either subcutaneously or intraocularly, two were tumorigenic when implanted subcutaneously attached to plastic plates. The remaining two are the first permanent rodent lines that have not been tumorigenic on plastic plates. Of the remaining six lines, all were tumorigenic on plates and two produced sarcomas at a higher frequency on plates than in suspension. Cytologic diagnoses of the cells implanted on plates, subcutaneously and intraocularly, correlated best with the results from plate implants. Of three mouse lines implanted on helices, two were equally tumorigenic in suspension and on helices, whereas the third was tumorigenic on helices only. The plate implant was more satisfactory technically than the helices and proved to be one of the most sensitive bioassays for the neoplastic state of cultured cells.
Lymphoma development from transplanted murine leukemia virus infected organ cultured thymuses: Inhibitory effect of in vitro interferon treatment
Authors: Riesenfeld Inger , Tufveson Gunnar , Alm Gunnar V. 
Published: February 2007

AbstractThymuses of 14‐day‐old AKR mouse embryos were infected with Gross murine leukemia virus (MuLV) and then maintained in organ culture for 3 weeks. When they were transplanted to 3‐week‐old (AKR X C3H)F1 mice, approximately 50% of these developed T lymphomas within 3–4 months. Most (22/23) tumors were of host, F1‐hybrid, origin while only one was of donor AKR type. No clear evidence for in vitro MuLV‐induced lymphoma cells was therefore obtained. Exposure of MuLV‐infected embryonic thymuses to interferon during the organ culture period significantly reduced the incidence of lymphomas in mice receiving such thymus transplants. Interferon also prevented the appearance of detectable numbers of MuLV antigen‐containing lymphocytes in infected organ‐cultured thymuses. In contrast, despite the use of very high interferon concentrations, no effects were seen on the number of viable thymic lymphocytes, their proliferation or responsiveness to the polyclonal T‐cell mitogens concanavalin A (Con A) and leukoagglutinin (LA). Thus interferon, presumably through an antiviral effect, can limit the MuLV infection in the thymus and its consequence, i.e.development of a lymphoma.
Characterization of the presumptive sarcoma cells in primary MSV tumors
Authors: Becker Sanne , Haskill Stephen 
Published: February 2007

AbstractPresumptive sarcoma cells have been isolated from primary MSV tumors induced in normal, immunosuppressed (ALG) and athymic nude mice. These cells were atypical in appearance, induced tumors in secondary hosts and expressed the viral antigens gp70, p30 and p12. In vitro growth characteristics of the MSV cells were tested in a variety of assays defining cell transformation. None of these indicated that the virus‐positive cells were transformed. Sex chromosome marker studies were carried out to determine if secondary tumor arose solely from proliferation of donor cells or through infection of host tissue. Tumors from female irradiated mice induced by injections of tumor cells derived from male mice contained a high proportion of metaphases of non‐donor origin, indicating that infection is an important but not the sole mechanism involved in tumor transfer. These data also demonstrated that many of the sarcoma cells are damaged as a result of infection as shown by the presence of chromosome breaks and aneuploid metaphases. Histologic sections of both regressor and progressor tumors showed that the virus‐positive cells were scattered as single cells surrounded by inflammatory cells, rather than as masses of dividing virus‐positive cells found in the MSV‐induced transplanted tumor. Collectively, these data support the contention that the MSV tumor is the manifestation of a response to a highly noxious virus infection rather than a tumor of dividing, transformed malignant cells.
Inhibition of rous sarcoma‐virus‐induced transformation by proteins involved in blood coagulation
Authors: de Petro G. , Brega A. , Mignatti P. , Barlati S. 
Published: February 2007

AbstractPlasma, serum and the main proteins involved in the final steps of blood coagulation, fibrinogen, thrombin and plasma transglutaminase, have been tested for their ability to inhibit cell transformation and/or to induce reversion of the transformed to the normal phenotype in RSV‐infected chicken embryo fibroblasts. The results obtained show that plasma, and not serum, fibrinogen, when converted to fibrin by thrombin, and activated transglutaminase alone prevent focus appearance and cause reversion of transformed to normal cell morphology.
Potential pre‐screening for therapeutic agents that induce differentiation in human myeloid leukemia cells
Authors: Lothm Joseph , Sachs Leo 
Published: February 2007

AbstractA cultured line of human myeloid leukemic cells has been used, to test for the ability of compounds used in chemotherapy to induce partial or complete differentiation of these leukemic cells. The compounds differed in their ability to induce specific differentiation‐associated properties. Effectiveness of induction of Fc and C3 rosettes was of the order actinomycin‐D > cytosine arabinoside > mitomycin‐C > adriamycin > bromodeoxyuridine > hydroxyurea. Induction of rosettes by actinomycin‐D required a 8212‐fold lower concentration than induction by hydroxyurea. All these compounds, except bromodeoxyuridine, induced the synthesis and secretion of lysozyme with the same order of effectiveness as for rosettes, but only actinomycin‐D and to a lesser extent bromodeoxyuridine induced the formation of mature granulocytes. Vincristine induced only a small increase in lysozyme. The results indicate that actinomycin‐D was the most potent inducer of differentiation in these human myeloid leukemic cells. It is suggested that pre‐screening of individual patients for the most effective compounds that can induce differentiation of their myeloid leukemic cells in culture, may prove beneficial for treatment in a from of chemotherapy based on the induction of normal differentiation in leukemic cells.
Modulation of target cell susceptibility to human natural killer cells by interferon
Authors: Moore M. , White Wendy J. , Potter M. R. 
Published: February 2007

AbstractThe spontaneous cytolytic activity of human peripheral blood lymphocytes in a short‐term 51chromium release assay was markedly enhanced by pretreatment with partially purified “Namalva” lymphoblastoid (type I)interferon (IF), provided that the target cells, five lymphoblastoid cell lines of variable natural killer (NK) sensitivity (K562, Molt 4, CCRF/CEM, Raji and Bri8), were not similarly treated with IF. When the targets were pre‐exposed to comparable concentrations of IF, their susceptibility to lysis by IF‐stimulated or unstimulated effectors was diminished, while exposure of both effectors and targets to IF for the duration of the cytotoxicity assay produced levels of cytotoxicity intermediate between those obtained when either effectors or targets were pretreated. The results indicate that, depending on the experimental design, IF is capable of exerting a protective effect on certain targets, a conclusion supported by competition assays Wherein IF‐treated cold K562 cells competed less successfully than untreated cold K562 cells for lysis of their radiolabelled counterparts by both IF‐stimulated and unstimulated effectors. The data suggest that certain lymphoblastoid targets, in common with effector lymphocytes, possess receptors for IF. Some possible biological implications of the protective interaction of IF with tumour targets, which is antagonistic to that on effector cells, are discussed.
Natural killer activity of lymphoid cells isolated from human ascitic ovarian tumors
Authors: Mantovani Alberto , Allavena Paola , Sessa Cristiana , Bolis Giorgio , Mangioni Costantino 
Published: February 2007

AbstractLymphocytes and tumor cells were isolated from the carcinomatous ascites of 24 patients with epithelial ovarian tumors by stepwise application of density and velocity sedimentation on discontinuous Ficoll‐lsopaque gradients and fetal bovine serum. Tumor‐associated lymphocytes showed a lower percentage of cells with receptors for sheep erythrocytes (E) or for complement than did peripheral blood lymphocytes from the same patients. NK activity was measured, 51Cr‐labelled K562 cells being used as targets in a 20‐h assay. Tumor‐associated lymphocytes showed significant NK activity. Cytotoxicity levels were lower than for peripheral blood effector cells from the same patients, and these in turn showed significantly lower cytotoxic capacity than peripheral blood lymphocytes from 64 control subjects. Similar results were obtained when lysis was measured after 4 h of incubation. Tumor‐associated lymphocytes forming E rosettes were at least as effective as the unseparated population. When tumor‐associated lymphocytes were mixed with normal effector cells, in three of six preparations with low NK activity tested, significant inhibition of normal lymphocyte NK activity was observed. Adherent macrophages from carcinomatous ascites, which contained lymphocytes that had suppressive activity, showed no inhibitory activity. Interferon (IF) boosted the NK activity against K562 of tumor‐associated lymphocytes. Purified ovarian carcinoma cells were relatively resistant to lysis by normal lymphocytes. However, they inhibited lysis of K 562 cells in cold target competition assays, though less efficiently than K 562 itself, and were consistently lysed when effector cells were stimulated with IF. It is therefore suggested that ovarian carcinoma cells express NK‐relevant recognition structures, but are relatively resistant to cytolysis by unstimulated effector cells.
Divergent effects of macrophage toxins on growth of primary tumors and lung metastases in mice
Authors: Mantovani Alberto , Giavazzi Raffaella , Polentarutti Nadia , Spreafico Federico , Garattini Silvio 
Published: February 2007

AbstractThe effects of silica and carrageenan on primary tumor growth and metastases were evaluated in C57BL/6 and BALB/c mice transplanted with the poorly immunogenic Lewis lung (3LL) carcinoma, mFS6 sarcoma and Madison 109 carcinoma spontaneously metastasizing to the lungs. Silica and carrageenan significantly enhanced lung metastases and decreased primary tumor weight in all three experimental models. A similar augmentation of lung secondaries was found after i.v. inoculation of 3LL tumor cells. The effects of carrageenan on primary 3LL tumor growth and metastases were observed also in thymus‐deprived animals. The effect of macrophage toxins was studied also in C57BL/6 mice transplanted with the M5076/73A ovarian carcinoma. This tumor spontaneously metastasizes to various abdominal organs, but not to the lung. After treatment with carrageenan, lung metastases were observed, but no effect on secondaries at other anatomical sites or on the primary tumor was detectable. It is suggested that host defense mechanisms impaired by silica and carrageenan may have divergent effects in the regulation of growth of some primary tumors and spontaneous lung metastases.
Tumorigenicity and in vitro characteristics of rat liver epithelial cells and their adenovirus‐transformed derivatives
Authors: Paraskeva Christos , Gallimore Phillip H. 
Published: February 2007

AbstractCloned and uncloned epithelial cultures were established from the liver of a 3‐week‐old AS rat. These epithelial cultures were neither tumorigenic nor did they display anchorage‐independent growth. One of the clones was cytogenetically normal after 53 in vitro passages (approximately 200 population doublings after cloning). Eight transformed lines were isolated from the liver epithelial cells after infection with adenovirus type 12 (Ad‐12). Five of these produced typical Ad‐12 T‐antigen, whereas three appeared to be T‐antigen‐negative. All were tumorigenic in newborn syngeneic rats. The T‐antigen‐positive transformed lines produced anaplastic‐epithelial tumors, whereas the T‐antigen‐negative transformed lines produced adenocarcinomas. Although all the transformed lines were tumorigenic, some were fibronectin‐positive while others produced no detectable fibronectin. The normal (untransformed) epithelial cells produced fibronectin. These results are interesting for two reasons: (1) there are relatively few reports of fibronectin on epithelial cells and (2) they emphasize the view that there is no absolute correlation between reduced fibronectin and tumorigenicity in transformed cells. The transformed lines displayed in vitro characteristics similar to those of transformants derived from embryonic and fibroblastic cell strains, notably, increased saturation density and changes in cellular morphology. Some of the transformed cell lines, but not all, displayed anchorage‐independent growth. All the transformed cell lines were picked from multi‐layered foci so that morphological criteria (i.e. piling‐up focus) for isolating transformants from the epithelial cultures were similar as in embryonic and fibroblastic transforming cell systems. With the new cell system we have developed we can, using the same epithelial cell line (clone C3), study both virus transformation and virus mutagenesis.
Oncogenicity of gibbon type‐C myelogenous leukemia virus
Authors: Kawakami Thomas G. , Kollias George V. , Holmberg Charles 
Published: February 2007

AbstractYoung gibbons that were experimentally inoculated with cell‐free gibbon ape leukemia virus (GaLV) and developed peristent viremia subsequently developed chronic granulocytic leukemia (CGL) with associated multifocal bone lesions and metastases. An 8‐month‐old gibbon inoculated with 105 tissue culture infectious virus (TCIV) developed acute myeloproliferative disease with associated bone lesions after a latency of 5 months, while a 9‐month‐old gibbon inoculated with 103 TCIV developed CGL after an II‐month latency. The clinical symptoms associated with the onset of leukemia were an increased number of leukocytes which were predominantly mature granulocytes, development of anemia, and multifocal bone lesions. Terminally, the animals had elevated immature granulocytes in the blood, cellular bone marrow with a predominant number of immature granulocytes, and hepatosplenomegaly. The gibbon with CGL had metastatic growth in the spleen and lung. Two 14‐month‐old gibbons that were inoculated with 103 TCIV and developed persistent neutralizing antibody to the virus infection remained free of hematopoietic disease, as did uninoculated animals. The fact that only animals with persistent viremia developed leukemia supports the oncogenicity of GaLV in gibbons.
Effect of horse antibody to rat alpha‐fetoprotein upon the growth of AH‐66 in donryu rats
Authors: Wepsic H. T. , Tsukada Y. , Takeichi N. , Nishi S. , Hirai H. 
Published: February 2007

AbstractStudies were undertaken to evaluate whether the intraperitoneal administration of horse antibody to rat alpha‐fetoprotein (HabRatAFP) would inhibit or prevent the growth of AH‐66 tumor cells inoculated into Donryu male rats. In animals inoculated with tumor subcutaneously there was 100% tumor growth in uninjected control animals and the administration of HabRatAFP prevented tumor growth in 7/24 (29%) of the animals. When animals were inoculated with tumor intraperitoneally, the inhibition of tumor growth by Hab‐RatAFP only occurred at tumor‐cell doses of 50,000, 10,000, and 5,000. In these three groups, 15/35 (43%) of those animals treated with Hab‐RatAFP did not develop tumor whereas 1/36 (3%) of the normal horse‐serum treated animals did not develop tumor. The majority of those animals which were cured of their tumors by Hab RatAFP treatment resisted tumor rechallenge. Studies were done to elucidate the mechanisms responsible for the anti‐tumor effect of HabRatAFP. AH‐66 tumor cells which were placed into millipore chambers, implanted intraperitoneally, were killed by the intraperitoneal administration of HabRatAFP. Studies were conducted to see if treatment with HabRatAFP to rat AFP might increase the immunogenicity of an inoculum of X‐irradiated tumor cells. In one experiment, no animals which received only X‐irradiated tumor cells resisted tumor rechallenge with 5 × 106 tumor cells whereas 6/11 (54.5%) of those animals which received X‐irradiated tumor cells and treatment with HabRatAFP resisted tumor rechallenge.