bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tumour‐related antigen specificities associated with 3‐methylcholanthrene‐treated rat embryo cells
Authors: Embleton M. J. , Baldwin R. W. 
Published: February 2007

AbstractRat embryo cells were treated in vitro for 18 h with 10 üg/ml 3‐methylcholanthrene (MCA). Syngeneic male rats were immunized with several inocula of treated cells to prepare antisera which were screened for membrane immunofluorescence reactivity against panels of established chemically‐induced syngeneic rat tumours. Three separate anti‐serum pools raised against MCA‐treated cells reacted with certain chemically‐induced tumours, whereas antisera to control (DMSO‐treated) cells were completely negative. The reactions observed were reproducible and highly specific for particular target tumours. Absorption studies indicated that each antiserum contained antibodies to several different antigens, present on different tumours. Antiserum prepared against extranuclear membrane from MCA‐treated cells, rather than intact MCA‐treated cells, was negative. This suggests that the antibody responses were directed against antigens arising subsequently to MCA treatment and injection into syngeneic hosts. It is postulated that carcinogen treatment results in the acquisition of multiple neoantigens among a treated cell population, which represent an early change in a sequence of events leading to malignant transformation.
Elevated titer of antibodies to simian sarcoma virus envelope antigen (gp70) and normal response to influenza virus in untreated danish Hodgkin's patients
Authors: Ebbesen P. , Due C. , Hesse J. , Kurth R. , Noble G. R. , Gallagher R. , Voller A. , Jensen G. 
Published: February 2007

AbstractUntreated Danish Hodgkin's disease (HD) patients and paired age‐ and sex‐matched controls were tested for serum antibodies to Epstein‐Barr virus (EBV), six strains of influenza virus and Simian sarcoma virus/Simian sarcoma‐associated virus [SSV(SSAV)] antigens. HD sera showed significantly elevated titers against EBV and both increased incidence and mean titer of antibodies to the envelope glycoprotein of SSV(SSAV), whereas testing against the influenza viruses revealed no differences between HD and controls. A focus reduction assay demonstrated a low incidence in HD and controls of sera with neutralizing effects against SSV(SSAV) and the “baboon” C‐type virus component of the human HL‐23 virus complex, which seemed coupled to HL‐A type W19.
Demonstration of antibody‐associated cellular cytotoxicity in patients with acute myelogenous leukemia before and after chemotherapy
Authors: Fäldt R. , Ankerst J. 
Published: February 2007

AbstractThis study demonstrates that a cytotoxic serum reactivity not requiring the presence of complement appears in the sera of patients with acute myelogenous leukemia. The reaction is detected upon short‐term incubation of sera in vitro with autochthonous mononuclear white blood cells from peripheral venous blood of patients at the acute stage of the disease. This reactivity was demonstrated in 18/18 patients. Generally, the cytotoxicity was low in patients at the acute stage of the disease, but increased after chemotherapy and reached the highest level at the onset of clinical remission or just before. No cytotoxicity could be demonstrated against autochthonous remission white blood cells. The serum activity could be absorbed and eluted from protein A‐Sepharose CL‐4B and was recovered in the 7S‐fraction of the sera after gel filtration on Sephadex G‐200 and ion exchange chromatography. This indicates that the demonstrated cytotoxicity is due to immunoglobulins of IgG‐class. It is believed that Fc‐receptor‐bearing cells present in the target cell preparations function as effector cells. The reaction is designated antibody‐associated cellular cytotoxicity (AACC).
Herpesvirus papio: State and properties of intracellular viral DNA in baboon lymphoblastoid cell lines
Authors: Falk Lawrence , Lindahl Tomas , Bjursell Gunnar , Klein George 
Published: February 2007

AbstractHerpesvirus papio (HVP) is an indigenous B‐lymphotropic virus of baboons (Papio sp.) present in latent form in baboon lymphoblastoid cell lines. It shares cross‐reacting viral capsid and early antigens with the Epstein‐Barr virus (EBV), and HVP DNA and EBV DNA show partial sequence homology. EBV‐specific complementary RNA was employed here as a probe to investigate the physical state of the HVP DNA component in baboon lymphoblastoid cells after fractionation of cellular DNA by density gradient centrifugation. Five virus‐producing cultures contained both free and integrated HVP DNA sequences while one non‐producing cell line had two or three viral genome equivalents per cell in an apparently integrated form. Further analysis of one virus‐producing line showed that the free HVP DNA fraction was composed of both linear and circular viral DNA. Contour length measurements of HVP circular DNA molecules by electron microscopy revealed that they were similar in length to the EBV circular DNA present in human lymphoblastoid cells.
Tumor metastases and cell‐mediated immunity in a model system in DBA/2 mice. V. Transfer of protective immunity with H‐2 identical immune T cells from B10.D2 mice
Authors: Schirrmacher V. 
Published: February 2007

AbstractEvidence is presented for the existence of immune T lymphocytes which have protective activity in vivo against the lethal effects of a metastasizing tumor. ESb, the metastasizing tumor cell line of our model system, which is highly malignant in syngeneic DBA/2 mice, can be rejected when transplanted into B10.D2 mice. Since B10.D2 and DBA/2 mice are identical at the H‐2 complex, cells could be transferred from the tumor‐resistant into the susceptible strain to determine whether they could confer protective immunity in a syngeneic environment containing disseminated ESb tumor cells. Protective immunity against ESb could be transferred into DBA/2 with spleen cells but not with ascites fluid from B10.D2 mice preimmunized against the ESb tumor cells. B10.D2 spleen cells taken between 6 and 22 days after tumor transplantation had protective immunity, while cells taken from animals 3 days after tumor transplantation, or from normal animals, had no significant protective effect. The cells in B10.D2 immune spleens with protective activity were sensitive to treatment with anti‐theta serum and complement and did not adhere to nylon‐wool columns. Such nylon‐wool column‐passed cells which were enriched for T lymphocytes had a higher protective activity then the unfractionated cells. DBA/2 mice which received viable ESb tumor cells subcutaneously on day 0 could be protected by intravenous inoculation of B10.D2 immune spleen cells only when these were given after the tumor cells (day +1, +3, +5, +7), not when given before (day −3 or −1). The mechanisms of protective immunity against tumor metastasis and the significance of our findings for completely syngeneic tumor systems will be discussed.
Actinomycin D restores in vivo sensitivity to differentiation induction of non‐differentiating mouse myeloid leukemia cells
Authors: Okabe Junko , Honma Yoshio , Hayashi Moriaki , Hozumi Motoo 
Published: February 2007

AbstractResistant mouse myeloid leukemia cells could not be induced to differentiate in vitro into mature macrophages and granulocytes by incubation with ascitic fluid or dexamethasone as inducer. Neither could endogenous inducers acting on resistant cells maintained in a diffusion chamber in syngeneic SL mice induce differentiation. However, when resistant cells were pretreated in vitro with low doses of actinomycin D they became sensitive to inducer in vitro or in vivo. The concentration of actinomycin D effective for this effect did not induce differentiation. The effect of actinomycin D was not due to inhibition of cell growth, since sensitivity was not observed when resistant cells were pretreated with the growth inhibitor 5‐fluorodeoxyuridine. When resistant cells were kept in a diffusion chamber in mice injected with low doses of actinomycin D they showed significant differentiation, suggesting that the in vivo effect of actinomycin D is partly attributable to sensitization of the resistant cells to endogenous inducers.
Suppression of lymphokine production by macrophages infiltrating murine virus‐induced tumors
Authors: Varesio L. , Herberman R. B. , Gerson J. M. , Holden H. T. 
Published: February 2007

AbstractImmune spleen cells from mice injected with murine sarcoma virus (MSV) can produce migration inhibition factor (MIF) in vitro after stimulation with intact tumor cells. We have now found that this effector function can be regulated by suppressor macrophages present in the tumor. The cells from the tumor (CfT) exert a strong suppressive effect even after treatment with anti‐Thy 1.2 plus complement but lose this capacity if adherent or phagocytic cells are removed, suggesting that the macrophage is the suppressor cell. The effects of the suppressor cells were exerted on a proliferation‐independent function of the lymphocytes, since MIF production, as well as its suppression, occurred even after proliferation of the lymphocytes was blocked by mitomycin‐C. The implications of these findings are that macrophages can suppress some early events involved in the activation of lymphocytes by antigen and that they do so through a mechanism that does not relate to the proliferation of the cells.
Structure of tumor antigen on hybrid cells between mouse mammary ascites tumor and mouse fibroblast L cells
Authors: Kubota Koichi 
Published: February 2007

AbstractSomatic cell hybrids between mouse fibroblast L cells and MM2 mouse mammary ascites tumor grown in BALB/c mice were isolated and the structures of tumor‐associated surface antigen of the hybrid cells, and parental MM2 and mouse L cells were investigated by the methods of radioiodination of membrane proteins, immunoprecipitation with a specific antiserum against tumor‐associated surface antigens of MM2 tumor (anti‐MM2 serum), and sodium dodecyl sulfate‐polyacrylamide gel electrophoresis. Two molecules of 105,000 and 76,000 daltons were detected on the MM2 cell surface, but no MM2 tumor antigen was detected on the mouse L cells. On the hybrids between these two kinds of cells, in addition to the two MM2 tumor antigens, molecules of 48,000–51,000 and 12,000 daltons were observed. On Sendai‐virus‐infected mouse L cells only a molecule of 68,000 daltons was detected by the anti‐MM2 serum, and furthermore this molecule was also detected by normal mouse serum, indicating that antibodies against Sendai virus were contaminating in both the anti‐MM2 and normal mouse sera used, and thus the molecules detected on the hybrid cells were distinguishable from possible viral components of Sendai virus on the hybrid cells. The results indicate that somatic cell hybrids between mouse L cells and MM2 tumor grown in BALB/c mice expressed on their cell surface the molecules that were not exposed on either parent cell. The experiments comparing newly detected molecules with the H‐2 antigen suggested that they were similar to H‐2 in their electrophoretic pattern.
Partial characterization of an antigen from a human myeloma cell and its reactivity with an anti‐myeloma cell serum
Authors: Krueger Robert G. , Hilton Pamela 
Published: February 2007

AbstractThis report describes studies carried out in an attempt to define the antibody specificity of a rabbit antiserum generated to the RPMI 8226 line of human myeloma cells and then isolate and characterize the antigen. The antiserum reacted to a significantly higher titer in a quantitative semi‐micro complement fixation assay with RPMI 8226 cells as compared to the RPMI 4098 line of human lymphocytes or normal human bone‐marrow cells, particularly after absorption with RPMI 4098 cells. A similar difference in reactivity was also noted for cell‐free lysates of the three different types of cells. A variety of different procedures were carried out to attempt to solubilize the antigens of the RPMI 8226 cell. Of the procedures tried, deoxycholate treatment of sonicated or freeze‐thaw extracts, 3 M KCI, autolysis and papain digestion were found to solubilize antigens from RPMI 8226 cells that reacted with anti‐RPMI 8226 cell serum absorbed with RPMI 4098 cells. Further, the solubilized RPMI 8226 cell antigens did not react with an antiserum to RPMI 4098 cells. Components solubilized from RPMI 4098 cells by similar procedures did not react with the absorbed anti‐RPMI 8226 cell serum to a significant titer. The initial studies carried out to characterize the components solubilized from the RPMI 8226 cell revealed that they were recovered in the included volume after gel filtration on Sephadex G‐200 and that this material consisted of three proteins with approximate molecular weights of 66,000, 55,000 and 31,000 daltons as estimated by electrophoresis on SDS‐acrylamide gels. These results indicate that the RPMI 8226 line of human myeloma cells possesses antigens not found on the RPMI 4098 line of human lymphocytes that can be solubilized and that react with an antiserum generated to intact RPMI 8226 cells.
Effect of parity regimen on the rate of occurrence of mammary tumors in a, C3H, and RIII mice
Authors: Moore Dan H. , Holben Jane A. 
Published: February 2007

AbstractThe occurrence rates of mammary tumors as affected by breeding regimen (early in life, late, continuous, or not at all) in A, RIII, and C3H mice were observed. The response to the breeding regimen was different in each of the three strains. The C3H stock was affected least, although the tumor occurrence rate was slower in virgins. In both A and RIII, only one litter at puberty resulted in the tumors occurring over the greatest age range; and in RIII mice, the occurrence rate and the mean tumor age were similar to those of the virgins. Normal continuous breeding caused the earliest tumors in all three strains, although in RIII mice, breeding after 18 weeks of age also caused very early tumors. The response of RIII strain to parity variations was more like that of humans than was the response of either of the other strains. Removal of the milk‐transmitted virus from these strains by foster‐nursing resulted in vastly different mammary tumor occurrence rates, the quantitative changes being different in each mouse strain.
Rapid release of fibronectin from human lung fibroblasts by biologically active phorbol esters
Authors: Keski‐Oja Jorma , Shoyab Mohammed , de Larco Joseph E. , Todaro George J. 
Published: February 2007

AbstractA sensitive radioimmunoassay technique has been used to study the effects of several phorbol esters on their ability to release fibronectin from cultured human lung fibroblasts into medium. The biologically active phorbol esters studied rapidly released fibronectin from cells into medium, with concomitant changes in the cellular morphology within 2 h. The quantity of fibronectin released was dose‐, time‐ and promoter‐dependent. The earliest release of fibronectin was seen within 30 min of onset of the incubation. Alterations in membrane topology elicited by phorbol esters appear to be responsible for the rapid release of fibronectin molecules from cells into the medium.
Decreased sensitivity to interferon associated with in vitro transformation of X‐ray‐transformed C3H/10T1/2 cells
Authors: Brouty‐Boyé Danièle , Gresser Ion , Baldwin Claire 
Published: February 2007

AbstractWe have compared the interferon sensitivity of parental 10T1/2 cells, having a phenotype characteristic of normal cells, with that of transformed cells isolated after X‐irradiation or treatment with methylcholanthrene. Transformed cells were 10‐ to 20‐fold less sensitive than the parental untransformed cells to the antiviral action of interferon and were also less sensitive to the inhibitory effect of interferon on cell multiplication. The decreased sensitivity of these cells to interferon is a useful marker of the transformed phenotype.
“NK‐like” cytotoxicity of human lymphocytes cultured in media containing fetal bovine serum
Authors: Golub Sidney H. , Golightly Marc G. , Zielske John V. 
Published: February 2007

AbstractHuman peripheral blood lymphocytes (PBL) were found to be highly cytotoxic to a human malignant melanoma target cell line after the PBL were cultured in medium supplemented with 20% fetal bovine serum (FBS). The effector cells had surface markers similar to those of non‐cultured NK effectors against melanoma targets. Both NK (without culture) and the culture‐induced cytotoxic effectors had Fcγ receptors, lacked Fcμ receptors and were either heterogeneous for E receptors or had low‐affinity E receptors. Cells required to generate the FBS response were sensitive to anti‐T serum plus complement, passed through a nylon‐fiber column, formed E rosettes, but lacked detectable receptors for the Fc portions of either IgG or IgM. These results suggest that events causing activation of T cells such as culture of PBL in FBS‐containing medium, result in the augmentation of NK activity.
Chromosome breaking activity of human feces and its enhancement by transition metals
Authors: Stich Hans F. , Kuhnlein Urs 
Published: February 2007

AbstractChloroform‐methanol extracts from human fecal samples were found to contain compounds which induce chromosome aberrations in Chinese hamster ovary cells. The induction of chromosome aberrations is stimulated by Cu2+ or Mn2+ and inhibited by Fe2+ or Fe3+. Addition of catalase to the fecal extract or the mixture of fecal extract and Mn2+ reduced the frequency of chromosome aberrations. These properties are indicative of hydroxyradical producing agents.
Biological and biochemical observations on isolates of EB virus from the malignant epithelial cells of two nasopharyngeal carcinomas
Authors: Crawford D. H. , Epstein M. A. , Bornkamm G. W. , Achong B. G. , Finerty S. , Thompson J. L. 
Published: February 2007

AbstractFoetal, adult seronegative, and cotton‐top marmoset lymphocytes have been transformed into cell lines by EB virus from the malignant epithelial cells of two nasopharyngeal carcinomas. The nature of the cell lines was checked by karyotyping and by light and electron microscopy, and the presence of the EB virus genome was demonstrated by immunofluorescence tests. Immunofluorescence also showed the incidence of EB virus‐producing cells in each line and this was checked by electron microscopy and the use of a lymphocyte transformation assay. Two foetal‐derived lines did not produce virus spontaneously, could not be activated with various inducers, and were found by DNA reassociation kinetics to carry only small numbers of genome copies per cell. An adult‐derived line produced virus, could be activated to produce more, and provided enough infectivity to transform marmoset cells. The resulting marmoset line made profuse transforming virus; it thus provides the first abundant source of NPC‐derived infectious EB virus for comparative studies. The results are discussed in relation to the interactions with comparable target cells of EB virus from normal individuals and from patients with other diseases.
Induction of reproductive system tumors in mice by N6‐(methylnitroso)‐adenosine and a tumorigenic effect of its combined precursors
Authors: Anderson Lucy M. , Giner‐Sorolla Alfredo , Greenbaum Jeffrey H. , Last‐Barney Kathleen , Budinger John M. 
Published: February 2007

AbstractInteraction of the naturally‐occurring nucleoside, N6‐methyl adenosine, with nitrite, a reaction that occurs readily under acidic conditions, results in the formation of a nitrosamine, N6‐(methylnitroso) adenosine [m6(NO)Ado]. This nitrosamine was given in the drinking water (1 mM solution) of non‐inbred Swiss mice from 3 weeks of age until death. It caused a significant increase in the incidence of primary lung tumors, compared with controls. It also induced reproductive tract tumors in 80% of the exposed females, including mammary tumors in 60% and uterine tumors in 25%. The precursors of m6(NO) Ado, m6Ado and nitrite, did not elevate tumor incidence when given singly, but when administered together resulted in a significant increase in numbers of lung tumors in the males. The nitrosamine base, N6‐(methylnitroso)adenine, was found to be a less potent carcinogen than m6(NO)Ado, causing lung tumors only in males and possibly a few mammary tumors in females. These results indicate the in vivo formation of a carcinogen from m6Ado and nitrite, and show that m6(NO)Ado induces neoplasms in the reproductive system of mice, an unusual target for a N‐nitroso carcinogen.
C. parvum treatment of transplanted rat tumours of spontaneous origin
Authors: Willmott N. , Pimm M. V. , Baldwin R. W. 
Published: February 2007

AbstractC. parvum (Wellcome CN6134) has been examined for suppression of a range of transplanted rat tumours of spontaneous origin. With five tumours (three mammary carcinomas and two fibrosarcomas) growth of comparatively high cell inocula (with respect to the minimum for growth in control rats) was suppressed by admixture with the vaccine. Equivalent dry weights of Glaxo, Pasteur or Connaught BCGs were relatively ineffective. Intralesional injection of C. parvum into three established tumours (two mammary carcinomas and one fibrosarcoma) retarded development of only one, the mammary carcinoma Sp4. With three mammary carcinomas and one fibrosarcoma, active specific immune stimulation with vaccines of viable or irradiated cells admixed with C. parvum was again consistently effective only with carcinoma Sp4, and this tumour was also susceptible to intradermal but not intravenous treatment with C. parvum alone.
Transformation of feline embryo cells in culture by a chemical carcinogen
Authors: Rhim J. S. , Nelson‐Rees W. A. , Essex M. 
Published: February 2007

AbstractA feline embryo cell line was treated in vitro with various levels of 7,12‐dimethylbenz[α]anthracene (DMBA) or dimethyl sulfoxide (control). Repeat treatment of DMBA only induced in vitro transformation of feline embryo cells following clonal growth and selection. The morphologically altered cells formed large cell aggregates and grew in this aggregate form when suspended in liquid growth medium above an agar base, formed colonies in soft agar, and grew to high saturation densities. However, no progressively growing tumors were produced when cells were inoculated into nude athymic mice. The transformed lines were negative for feline oncornavirus‐associated cell membrane antigen (FOCMA).
Absence of ecotropic or recombinant murine leukaemia virus in preleukaemic and leukaemic X‐irradiated NZB mice
Authors: Harvey Jennifer J. , Tuffrey Maureen , Holmes H. C. , East June 
Published: February 2007

AbstractNZB mice X‐irradiated with a single dose of 630 R when they were 1‐month old developed a high incidence of histologically defined lymphocytic leukaemia 8–25 weeks later. We have screened for murine leukaemia viruses (MuLV) in the lymphoid tissues of 8 of these leukaemic mice, and in 8 “preleukaemic”, apparently healthy NZBs, killed 1 month post irradiation. Xenotropic, but not ecotropic or recombinant MuLV, was detected by in vitro co‐cultivation of bone marrow, spleen and thymus with selectively permissive cell lines, followed by the immunofluorescence test for MuLV gs antigen, and the XC test. Our results are not consistent, therefore, with the concept that the factor causing the leukaemias was an oncogenic virus activated by X‐irradiation.