bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunological nature of the inhibition of BLV‐induced early polykaryocytosis by bovine sera
Authors: Astier Thérèse , Mamoun Robert , Guillemain Bernard , Parodi André L. , Duplan Jean‐Francois 
Published: February 2007

AbstractA quantitative in vitro assay (EPI) was developed for the serological detection of bovine leukemia virus (BLV) infection in cattle. Positive sera inhibit early polykaryocytosis (EP) induced by BLV. We report herein experiments which demonstrate that BLV‐induced antibodies are responsible for this inhibition. Serum fractionation by gel filtration and affinity chromatography indicate that EP‐inhibiting activity is mediated only by immunoglobulins of the IgG class. Furthermore, on the basis of their ion‐exchange chromatographic behaviour, these antibodies were classified as IgG1. We also ruled out the participation in the EP inhibition reaction of the other compounds such as polypeptides, including serum complement and interferon or DNA and RNA. These results demonstrate that EP inhibition by bovine sera is specific to BLV‐induced antibodies.
Tumor‐specific and tumor‐associated membrane antigens of rous sarcoma virus transformed hamster fibroblasts
Authors: Comoglio Paolo M. , Bertini Marilena , Prat Maria 
Published: February 2007

AbstractHamster fibroblasts transformed by an env− strain of Rous sarcoma virus (RSV) express at their surface tumor‐associated antigens of unknown origin and a tumor‐specific antigen (VCSA) which is not expressed by hamster fibroblasts transformed by unrelated DNA or RNA oncogenic viruses. This antigen was detectable by rabbit antibodies and a complement‐dependent 51Cr‐release cytotoxicity assay and is common to RSV‐transformed cells of different animal species. By comparing the anti‐VCSA serum with antisera directed against purified gp85, gs‐proteins, reverse transcriptase or detergentlysed virus particles, it was shown that VCSA is not a known virion structural protein. Moreover, VCSA expression does not correlate with viral replication since it is not detectable in chick embryo fibroblasts productively infected with the transformation‐defective virus RAV‐1 which shares virus structural genes with RSV. Finally, in hamster cells transformed by an RSV mutant, temperature‐sensitive for the ability to transform the host cell, VCSA expression at the cell surface correlates with the expression of the transforming gene.
A prospective evaluation of the leukocyte adherence inhibition test in colorectal cancer and its correlation with carcinoembryonic antigen levels
Authors: Shani Adi , Ritts R. E. , Thynne G. S. , Weiland Louis H. , Silvers Abraham , Moertel Charles G. , Go V. L. W. 
Published: February 2007

AbstractFifty‐four patients from the surgical gastroenterology service and 22 healthy controls have been prospectively evaluated in a single‐blind protocol by the LAI tube method. The LAI correctly identified 25 of 33 early colorectal patients staged as Dukes' B and C at surgery but none of the Dukes' D patients. An inverse relationship was seen between the results of the non‐adherence index (NAI) and CEA levels which was most pronounced in those with advanced colorectal cancer. The majority of Dukes' B and C patients having a “false negative” LAI had a CEA level greater than 2.5 ng/ml, suggesting that more advanced disease than that seen at surgery may be present. Two of 22 normal controls gave a borderline positive NAI. Some technical problems, including the relatively short life of the tumor extracts, are discussed.
Antibody‐dependent cellular cytotoxicity against epstein‐barr virus‐associated antigens in african patients with nasopharyngeal carcinoma
Authors: Pearson Gary R. , Johansson Bo , Klein George 
Published: February 2007

AbstractAntibody‐dependent cellular cytotoxicity (ADCC) was performed on serum samples from African patients with nasopharyngeal carcinoma (NPC) to determine whether antibody titers determined by this assay might be of prognostic value in this disease. The serum donors were divided into two groups: (1) those individuals who died within 2 years following diagnosis of NPC; and (2) individuals who responded well to therapy and survived for more than 2 years following diagnosis. The ADCC GMT for the survivor group was significantly higher than the GMT for non‐survivors (5,410 versus 615). Interestingly, there were a number of discordant sera in the non‐survivor group that had very low ADCC titers (<240) at diagnosis in the presence of high VCA titers. When ADCC titers were compared with anti‐EA or IgA antibody titers to VCA, a statistically significant inverse correlation was noted. These data suggest that ADCC titers might be of prognostic importance in African NPC.
Antibody patterns to herpesviruses in Kaposi's sarcoma. II. Serological association of american Kaposi's sarcoma with cytomegalovirus
Authors: Giraldo G. , Beth E. , Henle W. , Henle G. , Miká V. , Safai B. , Huraux J. M. , McHardy J. , De‐Thá G. 
Published: February 2007

AbstractThe prominent finding of this extended serologic analysis on American and African Kaposi's sarcoma (KS) patients and appropriately matched control groups is the detection of a specific serologic association of cytomegalovirus (CMV) with American KS patients. All American KS sera contained CMV antibodies and their geometric mean titers (GMT) were significantly higher than those in sera of melanoma patients (GMT ratio k = 5.3 to 7.7 by complement fixation [CF], k = 8.9 by indirect hemagglutination [IHA]) or in sera of age‐ and sex‐matched healthy controls (k = 12.6 to 16.0 by CF, k = 12.6 by IHA). The result is strongly reminiscent of the data obtained previously for European KS. Although the GMT to CMV of African KS patients were similar to the GMT of the American KS groups, their significance cannot be demonstrated due to the high background of CMV infections in the control groups. Complex mechanisms are hypothesized, by analogy with the Epstein‐Barr virus (EBV) involvement in Burkitt's lymphoma (BL), for a CMV involvement in the development of KS.
Antibody production by spleen cells of mice bearing MCA‐induced tumours: Search for suppressor cells
Authors: Yagello Micaël , Lespinats G. , Fridman W. H. 
Published: February 2007

AbstractThe antibody response to sheep red blood cells of spleen cells from mice bearing a methylcholanthrene (MCA)‐induced tumour was measured with the local hemolysis technique, after in vivo or in vitro immunization. The in vivo data varied according to the stage of tumour growth and were related to the splenomegaly developing during the tumour growth process. During the first 10–15 days after tumour grafting, the total number of plaque‐forming cells in the spleen increased in proportion to the spleen growth and thereafter remained relatively constant although the splenomegaly still progressed. Experiments performed in vitro were used to test the antibody response of mixtures of cells from normal mice and syngeneic tumour‐bearing animals. In most cases, no suppression of antibody production, due to cells from tumour‐bearing hosts, could be detected. The results suggest that those cells, which suppress cell‐mediated immune reactions, previously found in the spleen of animals bearing the MCA‐induced tumour, do not suppress antibody production.
Inhibition of mitogen and immune blastogenesis by two distinct populations of suppressor cells present in the spleens of fibrosarcoma‐bearing mice: Adoptive transfer of suppression
Authors: Farrar William L. , Elgert Klaus D. 
Published: February 2007

AbstractMitogen and immune blastogenic responses were progressively impaired in the spleens of mice with transplanted fibrosarcomas. Spleen cells from tumour‐bearing BALB/c mice were shown to suppress in vitro phytohemagglutinin (PHA) and immune blastogenesis of normal syngeneic spleen cells. Nylon wool column and other depletion techniques were utilized to characterize the cellular source of suppressive activity in tumour‐bearing host (TBH) spleens. Evidence is presented for two distinct suppressor cell systems operating in the spleens, but not lymph nodes, of TBH BALB/c mice. Both normal and TBH splenic macrophages were shown to suppress in vitro PHA and immune blastogenesis at high in vitro concentrations. No functional difference was detected between normal and TBH splenic macrophages. Suppressor T cells, detected in a macrophage‐depleted culture system, significantly suppressed normal spleen cell blastogenesis at low in vitro concentrations. Anti‐Thy 1 serum‐sensitive suppressor T cells elaborated an immunosuppressive material that could also mediate inhibition of blastogenesis. Tumour‐bearing host thymocytes also elaborated such a material. No soluble inhibitor(s) was released by macrophages or TBH lymph‐node cells. The suppressor T cell was tentatively defined as a spleen‐seeking, mildly nylon‐wool‐adherent, and anti‐Thy 1 serum and hydrocortisone succinate‐sensitive T lymphocyte. Adoptive transfer studies revealed that both macrophages (normal or TBH) and suppressor T cells were inhibitory. The data suggest that suppressor T cells may significantly affect blastogenesis at low in vitro and in vivo concentrations, whereas macrophage‐mediated suppression requires higher concentrations.
Heterogeneity of epstein‐barr virus. IV. Induction of a specific antigen by EBV from two transformed marmoset cell lines in ramos cells
Authors: Fresen K.‐O. , Cho M.‐S. , Hausen H. Zur 
Published: February 2007

AbstractInfection of cells of the EBV‐genome‐negative human B‐lymphoma Ramos line with viral isolates obtained from two EBV‐transformed marmoset cell lines (B95/8; Nyevu) resulted in the induction of a nuclear antigen (RAM‐ag) apparently different from other EBV‐associated antigen complexes. This antigen is revealed by indirect immunofluorescence and shows no detectable cross‐antigenicity with EBNA or any other known EBV‐associated antigen. EBV‐isolates from P3HR‐1 cells fail to induce a similar antigen in Ramos cells although they induce EBNA. No RAM‐ag was expressed, either after infection of cells of another EBV‐genome‐negative human B‐lymphoma line BJAB with B95‐8 EBV or in a series of EBV‐harbouring cell lines. Thus the antigen appears to be cell‐line‐specific for Ramos cells. It is also induced upon infection of either B95‐8 or P3HR‐1 converted Ramos sublines with EBV from B95‐8 cells. All human sera with RAM‐ag‐reactivity revealed antibodies against VCA. However, sera from patients with acute infectious mononucleosis containing high anti‐VCA‐antibodies did not react with RAM‐ag. Seroconversion for this antigen apparently more closely coincides with the appearance of EBNA‐directed antibodies.
Inhibition by lymphoblastoid interferon of growth of cells derived from the human breast
Authors: Balkwill F. , Watling D. , Taylor‐Papadimitriou J. 
Published: February 2007

AbstractHuman lymphoblastoid interferon inhibited the growth in vitro of fibroblasts and epithelial cells from normal, hyperplastic and neoplastic human breast tissue. At an interferon concentration of 103 international units (IU) per ml, the inhibitory effects on monolayer growth were completely reversible but the growth potential of cells at lower density in colony‐forming cultures was not completely recovered. Studies on the cell cycle distribution of interferon‐treated cells demonstrated that the growth‐inhibitory effect was not due to an effect on one specific phase of the cell cycle, but to a lengthening of all phases.
Reaction of 7,12‐dimethylbenz(a)anthracene with DNA of fetal and maternal rat tissues in vivo
Authors: Doerjer Gerhard , Diessner Helga , Bücheler Joachim , Kleihues Paul 
Published: February 2007

AbstractPregnant BD‐IX rats (21st day of gestation) received a single IV injection (15 mg/kg) of tritiated 7,12‐dimethylbenz(a)anthracene (DMBA), a dose known to induce a high incidence of nervous‐system tumors in the offspring. The animals were killed 12 h later and hydrocarbon‐deoxyribonucleoside products from DNA of maternal and fetal tissues were separated on Sephadex LH‐20 columns eluted with a 20–100% methanol gradient. Concentrations of the major DMBA‐DNA adduct varied considerably, with highest values in maternal intestine, liver and lung, followed by spleen, kidney and brain. In fetal intestine and liver, concentrations were 34% and 16% lower than in the respective maternal organs whereas the reaction with cerebral DNA was 2 1/2 times higher in fetuses than in the pregnant mother. This indicates that there is no significant placental barrier to DMBA or DMBA metabolites involved in DNA binding and that rat fetuses participate in the metabolic formation of the ultimate carcinogen.
Specific cytotoxic lymphocytes against syngeneic tumors are generated in culture in the presence of syngeneic, but not xenogeneic, serum
Authors: Fogel Mina , Segal Shraga , Gorelik Eliezer , Feldman Michael 
Published: February 2007

AbstractExperiments were performed to test the effect of xenogeneic (fetal calf) serum (FCS), as compared to syngeneic mouse serum (SMS) on the generation in culture of specific cytotoxic lymphocytes (CL) against syngeneic tumors. Sensitization in FCS against 3LL tumor cells resulted in CL cross‐reacting with B‐16 tumor cells and vice versa. Anti‐syngeneic fibroblast CL also cross‐reacted with 3LL. Such cross‐reactivities were shown to be derived from CL directed against FCS determinants. In contrast, sensitization in the presence of SMS resulted in CL directed against tumor‐specific antigens. Anti‐3LL generated in SMS lysed 3LL targets but not B‐16, and anti‐B‐16 lysed B‐16 but not 3LL. The two types of CL had two distinct reactivities in vivo. Anti‐3LL CL generated in FCS enhanced tumor growth in vivo, whereas anti‐3LL CL generated in SMS had an inhibiting effect on the growth of tumor cells. These results indicate that the application of syngeneic serum during in vitro sensitization against syngeneic tumors may open up new possibilities for the analysis of tumor‐specific antigens and for eliciting specific immune reactions against such antigens.
Ultrastructural detection of alpha1‐fetoprotein in hepatomas by use of peroxidase‐labelled antibodies
Authors: Kuhlmann W. D. 
Published: February 2007

AbstractHepatomas were induced in rats by feeding N‐nitrosomorpholine. Nodules from an alpha1‐fetoprotein (AFP)‐producing hepatoma were taken and subcutaneously injected into syngeneic hosts. From the first generation, the hepatoma producing most AFP was selected for further transfers. Four weeks after transplantation, the AFP concentration in the host rats was in the range of 0.8 to 1.5 mg AFP/ml serum. Transplanted hepatomas of the 14th to 19th generations were used for ultrastructural localization of AFP. Various methods of tissue processing were examined under the light and electron microscopes for intracellular detection of AFP by use of specific anti‐AFP antibodies conjugated with peroxidase. AFP was localized in the perinuclear space, the rough‐surfaced endoplasmic reticulum and the Golgi apparatus. Non‐membrane‐bound ribosomes did not stain for AFP. Fixation with 6% formaldehyde for 5 h followed by 6% formaldehyde plus 0.25–0.5% glutaraldehyde for 60–90 min proved best both for satisfactory ultrastructural conservation of the organs and for immunocytochemical localization of AFP. Concentrations of glutaraldehyde which exceeded 0.5% led to a significant decrease in immunocytochemical AFP reactions. On the other hand, weak aldehyde fixation poorly preserved ultrastructural detail and leakage of insufficiently fixed material caused staining artifacts. Under our conditions, thick frozen sections from well‐fixed hepatomas gave consistently reproducible results in that intracellular penetration of antibody‐peroxidase conjugates was superior to hand‐cut small tissue fragments. Tissue fixation and sampling were most important above all for other experimental steps.
Demonstration of specific cell‐mediated anti‐tumor immunity in lung cancer to autologous tissue extracts
Authors: Dean J. H. , Jerrells T. R. , Cannon G. B. , Kibrite A. , Baumgardner B. , Weese J. L. , Silva J. , Herberman R. B. 
Published: February 2007

AbstractCell‐mediated immunity (CMI) of lung cancer patients to autologous tumor antigens was assessed by mixed lymphocyte tumor interactions (MLTI) as measured in a microculture (200 μl) lymphocyte proliferation (LP) assay. Positive lymphoproliferative responses were observed with cryopreserved intact mitomycin‐C‐treated autologous tumor cells (8/12 or 67% patients reactive) and with hypotonic membrane extracts (HMP) of tumor cells (28/40 or 70%). Good correlation was found between reactivity to tumor cells and extracts in parallel testing. In contrast, HMP of autologous normal lung tissue elicited very little LP reactivity, with only one patient giving a weak response by the SI criterion and low level of n cpm. Upon repeat testing, many patients gave reproducibly positive LP responses to tumor HMP. Patients at all clinical stages of disease and with different histologic tumor types had a similar proportion of HMP reactivity. Most reactive patients responded to a broad range of protein concentrations of tumor HMP, and LP responses were frequently elicited with 1 μg or less of HMP. Thus, HMP appear to afford a convenient source of reactive tumor antigen for assessing anti‐tumor immunity.
Recovery of transforming EBV from non‐producer cells after superinfection with non‐transforming P3HR‐1 EBV
Authors: Fresen K.‐O. , Cho M.‐S. , Hausen H. Zur 
Published: February 2007

AbstractCells of the Raji and NC37 lines can be induced by chemical inducers, such as BrdUrd and IdUrd, or the tumor‐promoter TPA to EA‐expression only, but do not reveal any VCA synthesis. After super‐infection by nontransforming P3HR‐1 EBV, however, a varying percentage of the cell population shows VCA synthesis and releases infectious viral particles. The recovered virus differs biologically from P3HR‐1 EBV since it transforms human umbilical cord blood lymphocytes into EBNA‐positive lymphoblastoid cell lines. Cells of these established lines are susceptible to renewed infection by P3HR‐1 EBV which results in EA induction and VCA synthesis. Only cells of one line, NC37‐R1, spontaneously produce VCA and EBV particles, which reveal transforming properties and do not induce EA upon superinfection of Raji cells. Infection of P3HR‐1 EBV‐converted BJA‐B cells also leads to EA and VCA induction and the release of viral particles. In contrast to particles recovered from Raji and NC37 cells, no transforming activity was detectable in these virus preparations. According to these data, we propose that viral genomes persisting within Raji and NC37 cells are defective and become complemented by the superinfecting P3HR‐1 virus.
Secretion of plasminogen activator by normal, reactive and neoplastic human tissues cultured in vitro
Authors: Wilson Elaine Lynette , Dowdle Eugene 
Published: February 2007

AbstractPlasminogen activator secretion by 39 primary or early‐passage cultures of malignant human neoplasms has been compared with that of 16 similar cultures of benign neoplasms and 39 cultures of normal or reactive tissue. While normal cells of mesenchymal or neural origin secreted considerably less plasminogen activator than did cells from frankly malignant tissues, elevated levels of enzyme secretion were also encountered in cultures of benign neoplastic or reactive cells. In the case of epithelial tissue, no consistent relationship between plasminogen activator secretion and neoplasia could be documented. Our failure to observe, for any particular cell type, a reproducible correlation between malignancy and plasminogen activator secretion may be attributable to the artificial conditions of in vitro culture, where normal in vivo regulatory mechanisms do not obtain.
Delayed hypersensitivity reactions of cancer patients to antigens on lymphoid cell lines
Authors: Levine P. H. , Ho J. H. C. , Nkrumah F. , Periman P. , Mourali N. , Cannon G. , Middleton M. B. , Perkins I. V. , Herberman R. 
Published: February 2007

AbstractFour‐hundred and fifty niné cancer patients were skin tested with extracts from five lymphoid cell lines. More than 50% of patients with lymphoma had positive skin tests with the extracts prepared from the cell line derived from Burkitt's lymphoma (BL) and more than 50% of nasopharyngeal carcinoma (NPC) patients reacted to the NPC‐derived cell line extracts. Although the significant association between patient diagnosis and origin of cell lines suggested that tumor‐associated antigens were responsible for the pattern of delayed hyper‐sensitivity, problems in standardization of antigen potency and non‐specificity need to be resolved before this in vivo assay achieves its full potential.
Nonspecific activation of complement by leukemic cells
Authors: Shimbo Toshikazu , Yata Junichi , Okada Hidechika 
Published: February 2007

AbstractNon‐specific activation of complement (NAC) on cell membranes via the alternative pathway was studied by using leukemic cells and cells from a generalized reticulohistiocytosis. The cells were treated with normal human serum in veronal‐buffered saline containing ethyleneglycoltetra‐acetate and Mg++. Since human erythrocytes (HuE) are known to adhere to complement‐reacted cell membranes in an immune adherence reaction, complement activation on the cell membrane was confirmed by the rosette formation of HuE which is due to the generation of C3b molecules on the cell membrane. Only cells from Schilling‐type acute monocytic leukemias and cells from a generalized reticulohistiocytosis possessed NAC ability. All other leukemic cells tested, as well as normal hematopoietic and lymphoreticular cells, were NAC‐negative. Furthermore, none of the mitogens tested generated NAC ability on normal peripheral blood lymphocytes.
Immunological characterization of the low‐molecular‐weight dna binding protein of mouse mammary tumor virus
Authors: Arthur L. O. , Long C. W. , Smith G. H. , Fine D. L. 
Published: February 2007

AbstractP14, a low‐molecular‐weight MMTV protein previously identified as having DNA‐binding properties and encoded by the gag region of the MMTV genome, was purified by affinity chromatography on DNA‐sepharose. Immunological characterization of the purified protein showed that MMTV p14 shares no cross‐reactivity with gp52, gp36 and p10, antigens associated with the MMTV envelope, nor with p27 antigen found in the virion core. Purified MMTV p14 did show cross‐reactivity with purified intracytoplasmic A particles, supporting the concept that A particles are morphological precursors to MMTV cores. In addition, shared antigenic determinants between intracytoplasmic A particles and MMTV p27, p20 and p10 were demonstrated. MMTV p14 did not cross‐react with the low‐molecular‐weight DNA‐binding proteins of MuLV or of type‐C or ‐D viruses of higher mammals.
Neoplastic transformation of canine embryo cells in vitro by N‐methyl‐N′‐nitro‐N‐nitrosoguanidine
Authors: Rhim Johng S. , Park Dai K. , Arnstein Paul , Nelson‐Rees Walter A. 
Published: February 2007

AbstractA cell line derived from a normal beagle embryo was treated in vitro with various levels of N‐methyl‐N′‐nitro‐N‐nitrosoguanidine or dimethyl sulfoxide (control). Cells treated only with the carcinogen underwent morphologic alteration in vitro, and one of these altered cell lines produced tumors sub‐cutaneously when injected into NIH nude mice. The tumorigenic transformed line formed larger cell aggregates and grew in this aggregate form when suspended in liquid growth medium above an agar base.