bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cytotoxic antibodies to cultured lymphoblasts unrelated to epstein‐barr virus
Authors: Yang Czau‐Siung , Hewetson John F. 
Published: February 2007

AbstractA micro‐51chromium‐release assay was used to examine the possible relationship between antibodies cytotoxic to lymphoid cells and EBV infections of the donors. No correlation was found between sera capable of killing lymphoid cells pre‐labelled with51 chromium and the presence or absence of antibodies to the viral capsid antigen (anti‐VCA). Sera obtained from patients with infectious mononucleosis, Burkitt's lymphoma, nasopharyngeal carcinoma and Hodgkin's disease known to have elevated titers to anti‐VCA showed cytotoxicity similar to control values. There appeared to be both heat‐stable and heat‐labile complement‐dependent cytotoxic antibodies.
Virus—host‐cell relationship of Herpesvirus sylvilagus with cottontail rabbit leukocytes
Authors: Wegner Dennis L. , Hinze Harry C. 
Published: February 2007

AbstractLeukocyte suspensions from the lymph nodes, spleen and blood of cottontail rabbits experimentally infected with Herpesvirus sylvilagus were examined as fresh cell preparations and after in vitro cultivation for (1) the presence of virus, virus replication and release; (2) activation of virus by arginine deprivation or BUdR treatment and (3) the ability of such cell suspensions to give rise to actively replicating lymphoblastoid cell lines. Virus recovery was accomplished most consistently by co‐cultivation of viable cells on permissive DRK cell monolayers. The percentage of virus‐yielding cells, measured by formation of infectious centers when plated under agar on permissive monolayers, was generally less than 0.1%. Most cells yielding virus by this method showed no detectable intracellular virus in the sonically ruptured cell extracts. In vitro cultivation did not stimulate increased intracellular virus replication. It did, however, result in a 400‐ to 500‐fold increase in the number of cells capable of forming infectious centers in cultures of blood lymphocytes from two of 11 animals examined in this manner. Arginine deprivation of BUdR treatment also failed to activate productive infection. Maintenance of infected lymphoid cell cultures for 6 months did not result in establishment of actively replicating lymphoblastoid cell lines.
Tumour‐specific antibody neutralization of factors in rat hepatoma‐bearer serum which abrogate lymph‐node‐cell cytotoxicity
Authors: Robins R. A. , Baldwin R. W. 
Published: February 2007

AbstractSerum from hepatoma‐bearing rats has been shown to abrogate the cytotoxicity of immune lymph‐node cells when added to the target cells (blocking) or the effector cells (inhibition). Neutralization of these in vitro blocking and inhibitory reactions by sera containing antibody to tumour antigen has been demonstrated. Serum taken after hepatoma excision counteracted tumour‐bearer serum blocking only when the sera were mixed in equal proportions; syngeneic immune serum and a rabbit antiserum to hepatoma cells were shown to be more effective in neutralizing tumour‐bearer serum blocking activity. The syngeneic immune and rabbit antisera were also more effective than post‐excision serum in counteracting the inhibition of lymph‐node cell cytotoxicity by tumour‐bearer serum. The rabbit antiserum and syngeneic immune serum were found to block lymph‐node cell cytotoxicity at the level of the target cell, but these sera themselves did not inhibit lymph‐node cell cytotoxicity. These findings suggest that two distinct types of blocking at the target‐cell can occur: firstly, by sera containing high concentrations of antibody; and secondly, by sera containing immune complexes. The first type of blocking could be due to antibody masking of target‐cell antigens. The second type of blocking may involve interaction of the antigen part of the bound immune complex with receptors on the effector cell, so preventing their subsequent recognition of target cells.
Tumour metastasis in mice with reduced immune reactivity. II. Studies with a highly antigenic MCA‐induced sarcoma in thymectomized and/or sub‐lethally irradiated C57BL/6J mice
Authors: Suurküla Mart , Boeryd Bernt 
Published: February 2007

AbstractSpontaneous metastasis formation was studied in thymectomized and/or sublethally irradiated syngeneic C57BL/6J mice of a highly antigenic MCA‐induced sarcoma. The tumour has a low incidence of mainly pulmonary metastases in normal mice. The tumour was transplanted between 1 day and 3 months after irradiation. The immune competence was tested by the antibody response against SRBC and by studying the transplantation immunity against the tumour and allogeneic skin grafts. A wide range of immune‐suppressive states was obtained as shown by the antibody response against SRBC and by the transplantation immunity against the tumour. Local tumour growth at the transplantation site was more rapid in female than in male mice, but the difference was markedly reduced after the immunosuppressive procedures. This growth was slower in the thymectomized and irradiated groups than in the groups which were irradiated only, suggesting an inverse relationship between tumour growth and the degree of immunosuppression in this system. In contrast to this, tumour spread to lungs and lymph nodes was more pronounced in thymectomized and irradiated groups than in the groups irradiated only. The treatments caused varying and sometimes opposite effects on local tumour growth in the two sexes. The effect on tumour spread, if present, was always enhancing. Thus the effect of the two treatments on tumour growth was not similar to that on tumour spread. On some occasions the effects were even opposite to each other.
Cell interactions in adoptive immune rejection of a syngeneic tumor
Authors: Howell Stephen B. , Dean Jack H. , Esber Elaine C. , Law Lloyd W. 
Published: February 2007

AbstractStudies of adoptive tumor neutralization (the Winn test) in BALB/c mice rendered immune to the Simian Virus 40‐induced tumor mKSA indicate that: a) the reaction is extremely specific; b) there is a very close correlation between immunity detected by the Winn test and the ability of the intact animal to reject tumor; and c) immunity reflected by the 51chromium lymphocytotoxicity assay (CRA) and microcytotoxicity test (MCI) correlate poorly with in vivo resistance to tumor challenge and the Winn test. Investigation of the contribution of the immune donor lymphocytes to the reaction demonstrated that immune thymus‐dependent lymphocytes (T cells) were essential, but other donor cell populations were not. Proliferation of immune donor cells was not required. Recipient T cells do not participate in the reaction. We propose that donor T cells do not attack the tumor directly, but must interact with recipient cells to generate an effector response. Some of the parameters of the postulated cooperative interaction are discussed.
Observations on the type of infection by epstein‐barr virus in peripheral lymphoid cells of patients with infectious mononucleosis
Authors: Rickinson A. B. , Jarvis J. E. , Crawford D. H. , Epstein M. A. 
Published: February 2007

AbstractTransformation to continuous cell lines has been studied in cultures of peripheral leukocytes from infectious mononucleosis (IM) patients and in co‐cultures of IM leukocytes and foetal cord blood leukocytes of opposite sex. The transformed cells in the co‐cultures were of mixed origin with foetal cells usually predominating. Neutralizing antisera to EB virus markedly reduced or abolished the incidence of transformation in IM leukocyte cultures. This effect was not due to cytotoxicity and followed the pattern seen with cultures where transformation was known to depend on the intercellular transfer of infectious EB virus. The findings suggest that EB virus is harboured in peripheral lymphocytes of IM patients as a non‐productive unexpressed infection which is activated to produce virus in vitro, the particles released then infecting neighbouring cells to give transformed lines. The differences between this mechanism and the one whereby lines arise in culture from the malignant cells of Burkitt's lymphoma are considered, and their significance is discussed.
Increased polyamine concentrations in the cerebrospinal fluid of patients with brain tumors
Authors: Marton Laurence J. , Heby Olle , Wilson Charles B. 
Published: February 2007

AbstractAn automated method for the quantitative analysis of the polyamines putrescine, spermidine and spermine in cerebrospinal fluid (CSF) was used to analyze CSF samples from 37 patients with central nervous system (CNS) tumors and from 13p atients without tumors. The putrescine and spermidine concentrations in the CSF of most patients with tumors, particularly those with glioblastomas or medulloblastomas, were elevated when compared with those of non‐tumor‐bearing patients.
Requirement for cell replication in the fixation and expression of the transformed state in mouse cells treated with 4‐nitroquinoline‐1‐oxide
Authors: Kakunaga Takeo 
Published: February 2007

AbstractA31‐714 cells, a subclone derived from BALB/3T3, did not produce transformed foci when kept under culture conditions of density‐dependent inhibition after treatment with 4NQO in either the growing or the non‐growing state. The transformation frequency increased to nearly maximum level only when the cells had undergone more than four cell generations after 4NQO‐treatment. Cells which were first kept in a non‐growing state after 4NQO‐treatment, rapidly lost the ability to exhibit transformation even when they were subsequently returned to a growing state. On the other hand, the cells which were allowed one cell replication soon after 4NQO‐treatment retained their ability to produce transformed foci even after being kept in the non‐growing state for as long as 6 days thereafter. These results suggest that one cell generation is required for the fixation of transformation, and more than four cell generations are required for the expression of the transformed state.
Distribution of concanavalin A receptors on normal rat liver cells and zajdela ascites hepatoma cells
Authors: Roth J. 
Published: February 2007

AbstractThe distribution of Concanavalin A receptors in cultures of normal rat liver cells and of Zajdela ascites hepatoma cells of the rat was investigated by the Con A‐po technique (Bernhard and Avrameas, 1971). Con A‐po labelling of the cell surface showed a patchy distribution of Concanavalin A receptors in ascites hepatoma cells, whereas continuous Con A‐po labelling was seen at the surface of normal rat liver cells. The different distribution of Concanavalin A receptors was caused by rapid internalization of Con A‐po labelled material and not by a simple rearrangement of the receptors. The significance of this process is discussed with respect to Concanavalin A receptor mobility and membrane stability after cell transformation.
Neuraminidase‐mediated augmentation of in vitro immune response of patients with solid tumors
Authors: Watkins Elton , Gray Bruce N. , Anderson Leonard L. , Baralt Oscar L. , Nebril Lourdes R. , Waters Margaret F. , Connery Cheryl K. 
Published: February 2007

AbstractHost blood lymphocytes undergo accentuated blastic transformation when cultured with tumor cells pretreated with neuraminidase. The effect has been observed in 38 patients with such common solid tumors as bronchus carcinoma, skin melanoma, hypernephroma, or adenocarcinoma of the breast, lung, colon, or rectum. Individual response varied but often exceeded response to allogeneic cells. Three patients with glioblastoma of the brain did not respond. Lymphoblastic transformation was not observed in three of four cultures containing benign tumor or in any cultures containing normal tissue analogues of the malignant tumors.A factor in host blood serum inhibiting lymphoblastic transformation correlated to abnormal elevation of serum‐bound sialic acid. This blocking factor differed in specificity from enhancing antibody or serum blocking complexes described by other investigators. Blocking effects were observed when the tumor‐cell type of a serum donor differed from the cell type of the culture test tumor. Serum with abnormal elevation of bound sialate from a cancerfree human also non‐specifically blocked host response to tumor. The blocking effect could be eliminated by partial enzymatic removal of bound sialic acid from serum glycoproteins.
Cell‐mediated immunity to moloney sarcoma virus in mice. I. Analysis of antigens responsible for lymphocyte stimulation in regressor mice
Authors: Knight R. A. , Gorczynski R. M. 
Published: February 2007

AbstractPurified viruses, viral antigens, and cell extracts have been tested for their ability to stimulate protein synthesis by MSV‐M1 regressor spleen cells from BALB/c mice. Immune, but not normal cells, responded to MSV‐M, but not to MSV‐G virus1, and to the type‐specific viral envelope glycoprotein from MSV‐M, virus. Extracts of mouse embryo fibroblasts transformed by either MSV‐M or MSV‐G, however, specifically stimulated MSV‐M regressor spleen cells. Cells stimulated by different antigens, and by phytohaemagglutinin, had the same sedimentation profile and were identified as T‐lymphocytes.
Activation of carcinogenic polycyclic hydrocarbons in polyoma‐virus‐transformed cells as a prerequisite for polyoma virus induction
Authors: Huberman Eliezer , Fogel Marian 
Published: February 2007

AbstractPolyoma‐virus (PV)‐transformed cell clones, which are inducible for virus synthesis by various physical and chemical agents, metabolize the chemically non‐reactive carcinogen benzo (a)pyrene (BP) into water‐soluble products. In cultures of such clones, which metabolize BP to a level of 30–60% of that of normal cells, up to 10.4% of the cells were induced for PV synthesis by BP, 20‐methylcholanthrene (MCA) and 7,12‐dimethylbenz (a) anthracene (DMBA). No PV induction was observed with the non‐carcinogenic polycyclic hydrocarbons pyrene chrysene and benz (a)‐anthracene. A proportion of subclones, isolated from a PV‐inducible clone, which metabolized 0.1 μg or less BP per 106 cells, proved non‐inducible by any of the carcinogenic polycyclic hydrocarbons BP, MCA and DMBA. However, subclones which metabolized more than 0.3 μg BP per 106 cells were all inducible for PV synthesis by these carcinogens. Subclones isolated from an inducible clone pretreated with BP were shown to metabolize less than 0.1 μg BP per 106 cells and were resistant to virus induction by the carcinogenic polycyclic hydrocarbons. Benzoflavone, which inhibited the metabolism of BP in clones metabolizing high levels of this carcinogen, also prevented the induction of PV antigen and infectious virus synthesis in these clones. The data indicate a relationship between the carcinogenicity of polycyclic hydrocarbons and their ability to induce virus in the PV‐transformed cells and suggest that virus induction depends on metabolic conversion of these hydrocarbons into similar reactive compounds that are responsible for malignant transformation and mutagenesis.
Refractoriness of lymph‐node cells from tumour‐bearing animals
Authors: Burk Martyn W. , Yu Samuel , Ristow Sandra S. , McKhann Charles F. 
Published: February 2007

AbstractIn vitro lymphocyte stimulation by mitomycin‐C‐blocked tumor cells has been used to demonstrate tumor‐specific antigens in syngeneic murine systems and to follow the evolution of tumor immunity with the tumor‐bearing state. Mitomycin‐blocked tumor cells stimulated syngeneic lymphocytes from normal mice, from those bearing small tumors (less than 1 cm in diameter) and from tumor‐immune mice, sensitized by tumor‐cell inoculation and subsequent tumor removal, to undergo increased DNA synthesis as measured by the incorporation of tritiated thymidine. However, lymphnode cells from mice bearing tumors over 1 cm in diameter appeared to be maximally stimulated in vivo and incapable of further stimulation by the same tumor cells in vitro. This was reflected by the progressively increasing background levels of nucleic acid synthesis with the length of tumor‐bearing and the size of the tumor. Although lymphnode cells from mice with large tumors did not respond to the same tumor cells in vitro, they did have normal responses to PHA. Within 7–14 days of surgical removal of the tumor, specific lymphocyte responsiveness and background activity returned to previous normal levels, but reinoculation with 106 tumor cells resulted in progressive tumor growth and loss of specific in vitro responsiveness when the second tumor had reached the critical size of 1 cm in diameter. Brief exposure of tumor‐immune lymph‐node cells to a soluble antigen extract of the same tumor resulted in a marked increase in DNA synthetic activity compared to that obtained after exposure to an extract of a different tumor or an extract of normal muscle tissue. Normally responsive tumor‐immune lymph‐node cells, after brief exposure to a different tumor extract, muscle extract or medium alone underwent stimulation when cultured with mitomycin‐blocked tumor cells. However, normally responsive tumor‐immune lymph‐node cells, after brief exposure to a soluble antigen extract of the same tumor, initially underwent increased DNA synthesis, but were incapable of further stimulation by mitomycinblocked tumor cells. Tumor antigen, alone or complexed with antibody, was also demonstrated in the sera of mice bearing large tumors and is thought to be responsible for the refractoriness of lymph‐node cells from these mice to further stimulation in vitro. These experiments demonstrate that tumor size and the consequent antigen load to which the tumor‐bearing animals is subjected have a profound effect on tumor‐specific lymphocyte responsiveness.
Serologic evidence for cross‐reacting antigens in two carcinogen‐induced murine sarcomas
Authors: Fritze D. , Kern D. H. , Waldman S. R. , Pilch Y. H. 
Published: February 2007

AbstractSerological evidence is presented that two chemically‐induced (by methylcholanthrene and 3,4‐benz (a)pyrene) sarcomas of C3Hf mice contain cross‐reacting tumor‐associated cell‐surface antigens. Xenogeneic and syngeneic antitumor antisera against the two sarcomas were studied with an isotopic, complement‐dependent, antibody‐mediated microcytotoxicity assay and an isotopic antiglobulin test for the detection of antibodies to tumor‐associated antigens, in vitro. Absorptions with various tissues were performed which consistently revealed that the specific activity of the antitumor antisera could be removed by absorption with cells from either chemically‐induced tumor, while absorption with syngeneic normal adult tissues, normal fetal tissues, or cells from a histogenetically unrelated tumor (spontaneous mammary carcinoma) failed to remove any specific activity. In view of the individual character of carcinogen‐induced tumor antigens as detected by tumor transplantation techniques, our results suggest that chemically‐induced murine sarcomas (even when induced by different carcinogens) contain both private and common cell‐surface antigens, the latter detectable by serological methods. These common tumor‐associated antigens may be related to a viral genome involved in the malignant transformation of carcinogen‐induced murine sarcomas.
Demonstration of oncogenic potential of mammalian cells transformed by dna‐containing viruses following photodynamic inactivation
Authors: Li Jui‐Lien H. , Jerkofsky Mary Ann , Rapp Fred 
Published: February 2007

AbstractThe oncogenic properties of hamster embryo cells transformed by herpes simplex virus type 1 (HSV‐1) and type 2 (HSV‐2) and SV40 virus following photodynamic inactivation using neutral red were determined by subcutaneous inoculation into newborn Syrian hamsters. Cells transformed by all three viruses produced palpable tumors after different latent periods. Histopathological examination showed that HSV‐2 tumors were fibrosarcomas and metastases were often seen in the lungs. HSV‐2 primary tumors were reinoculated subcutaneously into weanling hamsters; they developed palpable tumors within 2 weeks. HSV‐specific antigens were detected in the cytoplasm and/or on the surface of both the HSV‐1 and HSV‐2 tumor‐cell cultures by the indirect immunofluorescence technique. The same method revealed SV40 tumor antigen in the nuclei of the SV40 tumor cells. Sera from HSV or SV40 tumor‐bearing hamsters gave positive reactions when tested against HSV‐infected hamster cells or SV40‐infected monkey cells, respectively. These results demonstrate that herpes simplex virus and SV40, whose infectivity was lost following photodynamic inactivation, retained the virus genetic information necessary for transformation of normal cells to an oncogenic phenotype.
Quantitative estimation of mouse mammary tumor virus (MTV) antigens by radioimmunoassay
Authors: Verstraeten A. A. , Van Nie R. , Kwa H. G. , Hageman Ph. C. 
Published: February 2007

AbstractA radioimmunoassay for the antigens of the mouse mammary tumour virus has been developed. 125Iodine‐labelling of intact virus [derived from mammary tumours of (C3H × 020) F1 mice] followed by ether extraction and separation of the ether and water layers resulted in a separation of the labelled material into two main groups of antigenic components. The intact labelled material from each group was separated from viral debris and other possible contaminants by affinity chromatography. The antigens of the ether phase were proved to belong mainly to the viral nucleoid whereas the water phase contained mainly envelope antigens. No type‐specific antigens could be demonstrated in either of the phases. Radioimmunological assessment of plasma revealed that in the plasma of MTV‐S‐ and MTV‐P‐positive animals viral antigens were only measurable when palpable mammary tumours were present, whereas in MTV‐L‐positive tumour‐bearing animals some negative samples were found. In milk of individual nontumour‐bearing mice a close correlation was found between the expression of viral antigens and the generally accepted presence of virus in the strain of mice. In milk, viral antigen levels tend to increase with parity with a possible decrease after a finite number of pregnancies. In a pilot study the presence of MTV antigens could also be demonstrated in epididymis extracts of male GRS/A mice. Genetical analysis of the low‐virulent MTV‐L by radioimmunoassay of milk is in progress.
Influence of administration route and dosage schedule on tumor response to nitrosoheptamethyleneimine in rats
Authors: Taylor H. W. , Nettesheim P. 
Published: February 2007

AbstractNitrosoheptamethyleneimine (NHMI) was tested for carcinogenicity in Fischer‐344 and Sprague‐Dawley rats by intragastric administration and subcutaneous injection. Cumulative doses ranged from 5.5 to 1,200 mg/kg, and dosage schedules ranged from 40 serial administrations to one single injection. No difference in response was seen between sexes or strains of rats. Following the highest carcinogen doses by intragasritc administration, a high incidence of squamous‐cell tumors occurred in the lung. The highest incidence of squamous‐cell tumors occurred in the nasal cavity, trachea and esophagus. Following subcutaneous injection, tumors induced in the lungs were all alveologenic adenomas and adenocarcinomas. The upper respiratory and gastrointestinal tracts were again the most commonly affected sites, with tumors similar to those of the first group. Intragastric administration was more effective in producing tumors than was subcutaneous injection, and administration of multiple small doses was more efficient than single large doses. The results demonstrated that the route and schedule of administration markedly influenced the tumor response to NHMI, both quantitatively and qualitatively.