bluuebunny/crossref_metadata_2025_split huggingface dataset:
The immune response to primary moloney sarcoma virus tumors in BALB/C mice: Cellular and humoral activity of long‐term regressors
Authors: Lamon E. W. , Andersson B. , Wigzell H. , Fenyö E. M. , Klein E. 
Published: February 2007

AbstractAdult BALB/c mice injected with Moloney sarcoma virus (MSV) developed local tumors at the site of inoculation which spontaneously regressed within 20–25 days after injection. Lymphocytes and sera from long‐term regressor animals were examined for their specific activities in vitro against Moloney leukemia virus (MLV) determined antigen (s). Specific activity against the MLV‐positive target cells by the lymphocytes from these animals was found to be dependent on the presence of B lymphocytes. In order to investigate some of the possible mechanisms of action of the immune B cells, sera, which were characterized by complement‐dependent cytotoxicity, immunofluorescence and virus neutralization, were tested for their ability to stimulate normal syngeneic lymphocytes to be active against the target cells. These antisera placed on the target cells were found to stimulate normal unfractionated or T deprived cells to reduce the target‐cell numbers. This effect was not found with normal T lymphocytes. Time‐course kinetics of this antibody‐dependent cell‐mediated activity in vitro were defined.
Studies on the mechanisms of invasion in cancer. III. Purification of a neutral protease of rat ascites hepatoma cell associated with production of chemotactic factor for cancer cells
Authors: Koono Masashi , Ushijima Kenichiro , Hayashi Hideo 
Published: February 2007

AbstractA neutral protease was extracted from rat ascites hepatoma cells and effectively purified by fractionation with ammonium sulfate followed by chromatography using TEAE‐cellulose and hydroxylapatite in that order. The protease eluted in 120 mM phosphate buffer (pH 6.8) on hydroxylapatite, on experimental injection, produced locally a factor chemotactic for cancer cells and induced an extravascular emigration of circulating tumor cells followed by a formation of metastatic secondary tumors. It was SH‐independent or metal‐independent. The separation of the protease from nucleic acid was performed by disc electrophoresis. By contrast, another neutral protease, alkaline protease and acid protease from the same cells were negative in causing an extravascular emigration of circulating tumor cells.
Immunogenetic aspects of nasopharyngeal carcinoma. II. Analysis of ABO, rhesus and MNSS red cell systems
Authors: Hawkins B. R. , Simons M. J. , Goh E. H. , Chia K. B. , Shanmugaratnam K. 
Published: February 2007

AbstractThe distribution of red cell antigens of the ABO, Rhesus, MNSs, and P systems was studied in 102 Chinese patients from Singapore, Malaysia, and Hong Kong. The distribution of the same antigens was also studied in 166 Singapore blood donors and in 43 patients suspected of having NPC but in whom malignancy was not detected on histological examination of biopsies of nasopharyngeal tissue, and who are presumed to be free of NPC. No statistically significant differences were found in either phenotype or genotype frequencies between the three groups. The results of surveys investigating the possible association between blood groups and NPC are reviewed. If the hypothesis of a genetic predisposition to NPC is correct, it appears unlikely that the blood group genes which were studied here are involved, at least as independently functioning genes. However, in Chinese patients, a systematic study of dialect sub‐groups is necessary before a conclusion can be drawn.
Immunogenicity of embryonic antigens associated with chemically induced rat tumours
Authors: Baldwin R. W. , Glaves Dorothy , Vose B. M. 
Published: February 2007

AbstractImmunization of syngeneic rats with mid‐gestation rat embryo cells failed to elicit resistance to challenge with chemically‐induced rat hepatomas and sarcomas. In addition, lymphoid cells from multiparous female rats were uniformly ineffective in transferring tumour immunity to normal rats. In spite of this apparent lack of immunogenicity, serum and lymph‐node cells from animals immunized with tumour were cytotoxic for cultured embryo cells known to share embryonic antigen specificities with tumour cells. It is concluded that, although immunogenic, the tumour‐associated embryonic antigen does not function as a tumour rejection antigen.
Preparation and isolation of immunologically active glycopeptides from carcinoembryonic antigen (CEA)
Authors: Banjo C. , Gold P. , Gehrke C. W. , Freedman S. O. , Krupey J. 
Published: February 2007

AbstractIn order to determine the structure of the tumor‐specific immunodominant group of the carcinoembryonic antigen (CEA) of human gastro‐intestinal tumors, immunologically active fragments from this glycoprotein were prepared by partial enzymatic hydrolysis using the proteolytic enzyme nagase. The fragments were purified by sequential molecular sieve, adsorption and ion exchange chromatography, and were analysed for carbohydrate and amino‐acid composition by gas‐liquid chromatography. The antigenic activity of each fragment was tested using both the Z‐gel and Farr radioimmunoassay techniques for CEA. Immunologically active glycopeptides with molecular weights of 1,000–5,000 Daltons, which contained the tumor antigenic determinant of CEA, had relatively high contents of N‐acetyl‐D‐glucosamine, aspartic acid or asparagine, and glutamic acid or glutamine.
Serum inhibitors of cellular immunity in human neuroblastoma. IgG subclass of blocking activity
Authors: Jose David G. , Skvaril Frantisek 
Published: February 2007

AbstractAn autochthonous in vitro assay of cytotoxic cellular immunity against neuro‐blastoma cells was used to measure the specific blocking activity of serum from three children with untreated neuroblastoma. The blocking sera were fractionated into four IgG subclasses and blocking activity was found to be associated with IgG1 and IgG3, with lesser activity in IgG4 proteins.
Effect on anti‐alpha‐fetoprotein serum on some cultured tumor cells
Authors: Tsukada Yutaka , Mikuni Masahiko , Watabe Hiroyuki , Nishi Shinzo , Hirai Hidematsu 
Published: February 2007

AbstractThe cytotoxic effect of horse anti‐α‐fetoprotein (AFP) sera on some cultivated rat tumor cells was investigated. Antisera inactivated at 56°C for 30 min revealed a selective inhibitory effect on the gowth of AFP‐producing cells of a rat ascites hepatoma line, AH66. However, a small portion of the cell population survived and gradually increased in number. These viable cells were found to be low‐AFP‐producing cells. Extremely low‐AFP‐producing cells could be separated by repeated treatment with the anti‐AFP sera. The survival time of rats transplanted with these low‐AFP‐producing cells was about twice as long as with the original AH66 cell line. The growth of high‐AFP‐producing clones of the AH66 cell line was inhibited within 48 h of cultivation. On the other hand the growth of low‐AFP‐producing clones was only slightly inhibited. The positive membrane immunofluorescence test of AFP‐producing cells suggested that anti‐AFP antibody adhered to AFP secreted on the cell surface. This antigen‐antibody binding on the cell surface may inhibit cell multiplication. The cytotoxic index and the rate of AFP production were closely correlated. Under the experimental conditions of this study, there was no observable effect when complement was added to the antisera.
In vitro cloning of a rat ascites hepatoma cell line, AH66, with special reference to alpha‐fetoprotein synthesis
Authors: Tsukada Yutaka , Mikuni Masahiko , Hirai Hidematsu 
Published: February 2007

AbstractCell clones producing low amounts of alpha‐fetoprotein were isolated from AH66 cell line from an ascites hepatoma producing high amounts of AFP in vitro. The growth rate and the chromosome constitution were compared between clones producing high and low amounts of AFP. No significant correlation was found between the rate of AFP production and the chromosome number. A slight increase in host survival time was observed when the rats were transplanted with low‐AFP‐producing clones compared with high‐AFP‐producing clones.
Gel electrophoresis and isoelectric focusing of mitochondrial and viral‐induced thymidine kinases
Authors: Kit Saul , Leung Wai‐Choi , Trkula David , Jorgensen George 
Published: February 2007

AbstractSubcellular fractionation studies have shown that the thymidine (dT) kinases induced by vaccinia and herpes simplex type 1 (HSV‐1) viruses are localized principally in the cytosol fraction. Isoelectric focusing, disc polyacrylamide gel electrophoresis (disc PAGE), and glycerol gradient centrifugation experiments were carried out in order to compare the viral‐induced enzymes with cellular dT kinases from the following sources: (1) cytosol fractions of dT kinase‐positive human (HeLa S3) and mouse (LM) cells; and (2) mitochondrial extracts of HeLa S3 and of bromodeoxyuridine‐resistant, dT kinase‐deficient HeLa (BU25) and LM (TK−) cells. These analyses revealed that the sedimentation coefficients of the vaccinia and HSV‐1 induced dT kinases were similar to those of the HeLa S3 and LM cytosol enzymes, but the viral‐induced dT kinases exhibited greater disc PAGE mobilities (Rm values) and lower pI values than the HeLa S3 and LM cytosol dT kinases. The vaccinia and HSV‐1 induced dT kinases were distinctly different. Both viral‐induced enzymes also differed from LM (TK−) mitochondrial dT kinase in sedimentation coefficient, Rm and pI. Small differences were found between the HSV‐1 induced dT kinase and a human mitochondrial‐specific isozyme. However, the HSV‐1 induced dT kinase resembled the mitochondrial‐specific human and mouse dT kinases in ability to substitute GTP, UTP and CTP for ATP as phosphate donors in the dT kinase reaction. In contrast, the LM and HeLa S3 cytosol dT kinases and the vaccinia‐induced dT kinase efficiently utilized only ATP as a phosphate donor. Recovery of LM and HeLa S3 cytosol dT kinase activities from gels was very poor when ribonucleoside 5'‐triphosphates were omitted from the upper buffer solution during disc PAGE. Also, in the absence of ATP, enzyme recoveries of mitochondrial and viral‐induced dT kinases were reduced and Rm values were decreased.
Detection of oncornavirus‐like particles in HeLa cells. I. Fine structure and comparative morphological classification
Authors: Gelderblom Hans , Bauer Heinz , Ogura Hajime , Wigand Reinhard , Fischer Anna B. 
Published: February 2007

AbstractOncornavirus‐like particles have been consistently observed over a period of 3 years in HeLa cells obtained from several laboratories. The particles mature by budding, in that previously fully assembled A‐type‐like particles are enveloped by the protruding cell membrane with subsequent release of the virion. When compared morphologically to B‐ and C‐type particles, distinct differences were observed; however, the HeLa particles closely resemble two primate viruses, namely the Mason‐Pfizer monkey virus and a recently discovered virus derived from human brain cells. HeLa particles demonstrate a narrow host range. Thus a new morphological group of viruses emerges that might be specific for primates.
Oncornavirus‐like particles in HeLa cells. III. Biochemical characterization of the virus
Authors: Watson Kenneth F. , Mölling Karin , Gelderblom Hans , Bauer Heinz 
Published: February 2007

AbstractOncornavirus‐like particles observed and purified from HeLa cell culture supernates have a density in sucrose of 1.16‐1.17 g/cm3. They contain DNA polymerase and ribonuclease activities with properties characteristic of reverse transcriptase and ribonuclease H of known oncornaviruses. The DNA polymerase and RNase H are antigenically similar to those of Mason‐Pfizer monkey virus.
Further studies on sv40 permissive cell protein factor(s) allowing rescue of infectious virus and viral DNA from non‐shedder SV40‐transformed cells
Authors: Lavialle Ch. , Suarez H. G. , Estrade S. , Cassingena R. 
Published: February 2007

AbstractThe factor (s) responsible for rescue of the SV40 genome from transformed cells (activator) is essentially detected in nuclear extracts from permissive cells. Removal of nucleic acids from these extracts improves their activating capacity on transformed cells. By increasing the yield of infectious viral DNA, virions become frequently detectable. For a given experiment, a correlation is obtained between the protein concentration of the extract and the yield of infectious SV40 DNA. Unlike nuclear extracts from normal or SV40‐transformed permissive cells, those from normal nonpermissive cells are ineffective in rescuing the viral genome. The biological activity of the factor(s) is preserved at −70° C for at least 3 months.
Purification and chemical characterization of α‐fetoprotein from rat and mouse
Authors: Watabe Hiroyuki 
Published: February 2007

AbstractAlpha‐fetoprotein of the rat was immunochemically purified and characterized. Mouse α‐fetoprotein, which cross‐reacts with antibodies to rat α‐fetoprotein, was also purified. Rat α‐fetoprotein was heterogeneous in disc electrophoresis and isoelectric focusing and had two different isoelectric points at pH 4.76 and 5.05. Mouse α‐fetoprotein was homogeneous when analyzed similarly. The molecular weight of both rat and mouse α‐fetoprotein was 70,000 as determined by gel electrophoresis in the presence of sodium dodecyl sulfate. The two specimens revealed a close similarity also in some other physicochemical, chemical and immunological properties.
Synergism between host anti‐tumor immunity and combined modality therapy against murine breast cancer
Authors: Stolfi R. L. , Fugmann R. A. , Stolfi L. M. , Martin D. S. 
Published: February 2007

AbstractThe tumor‐specific immune status of mice bearing primary transplants of spontaneous syngeneic breast tumors was monitored by in vitro methods before, during and after treatment with a regimen of surgical tumor enucleation plus the first course of a combination of chemotherapeutic agents which has yielded significant numbers of lifetime cures of spontaneous mammary adenocarcinoma in this murine host. Cell‐mediated tumor immunity, which had become undetectable in the presence of large tumors, reappeared within 8 days following enucleative tumor surgery. In addition, tumor‐specific blocking activity which was present in the serum of tumor‐bearing mice became undetectable within 15 days after tumor surgery. Nevertheless, these favorable changes in the immune setting following tumor surgery were not adequate to substantially prevent recurrence of tumors from the microfoci of tumor cells residual to the surgical procedure. In contrast, tumor recurrence was significantly inhibited in animals that received an adjuvant course of intermittent combination chemotherapy. Results of the immunological studies indicate that the curative success of this therapeutic regimen is dependent upon the achievement of a complementation in anti‐tumor activity between the combined modality therapy and host immunity. Of paramount importance is the fact that the schedule of chemotherapy did not produce any measurable suppression of tumor‐specific immunity, and did not interfere with the beneficial shift in the balance between tumorimmune reactivities which followed surgical reduction of the tumor burden. In addition, the repeated administration of the drugs serves to keep down the number of tumor cells during the period of time following surgery which has been shown to correspond with the reappearance of cellular anti‐tumor activity and the disappearance of humoral blocking activity. Consequently, the tumor‐cell number is still relatively low when efferent immunological reactivity is most favorable for tumor‐cell rejection.
Effects of adenosine 3′5′‐cyclic monophosphoric acid on the morphology, growth and cell cycle of earle's L cells
Authors: Taylor‐Papadimitriou Joyce 
Published: February 2007

AbstractThe morphology of Earle's L cells is radically altered after incubation with adenosine 3′5′‐cyclic monophosphate (cyclic AMP) and cell growth is inhibited. The concentration of nucleotide required to completely inhibit cell growth depends on the initial cell density although the breakdown of cyclic AMP in the supernatant fluid to adenosine is independent of the cell density. A decrease in mitotic index is noted several hours after the addition of cyclic AMP, while a reduction in the fraction of cells in S is only observed after 2 days. Upon removal of the drug an increase in the number of cells synthetizing DNA (as detected autoradiographically) is observed well before the increase of mitotic rate. These results suggest that cells are blocked in moving through S to G2. Cells resume normal growth rates and morphology only 6–8 days after the removal of cyclic AMP, but can then be propagated indefinitely.
Development of teratomas from displaced visceral yolk sac
Authors: Sobis H. , Vandeputte M. 
Published: February 2007

AbstractA surgical procedure for the induction of extra‐uterine teratomas in pregnant R rats is described. These teratomas originate from the visceral yolk sac and are characterized by the presence of a variety of well‐differentiated tissues. The tumors have the histological and ultrastructural morphology as well as the biological characteristics of benign teratomas. Their origin and development are discussed in relation to the multipotentiality of yolk‐sac cells.
Comparative differentiation and numeration of CFUs from mice infected either by the anemia‐ or polycythemia‐inducing strains of friend viruses
Authors: Wendling F. , Tambourin P. , Gallien‐Lartigue O. , Charon M. 
Published: February 2007

AbstractA comparative study of alterations in the CFU (colony‐forming unit) compartment of susceptible mice infected either with the anemia‐ (FVA) or the polycythemia‐inducing Friend virus (FVP) indicated that: (1) Whatever the type of virus used, the absolute number of CFU is increased in the spleen and in the blood; (2) The splenic CFU augmentation parallels the increase in cellularity so that the CFU concentration remains equal to that of control spleens; (3) Circulation of the CFU in the peripheral blood is multiplied by a factor of about 100 in FVA‐infected mice and 500 in FVP‐infected mice 25 days after infection; (4) In the femoral bone marrow, the CFU number is either unaltered (FVP infection) or decreased (FVA infection). Stem cells from leukemic mice are able to give rise to colonies of differentiated hematopoietic cells as do control CFU. The distribution of the various types of colonies is similar between the different tissues and the different groups of donors. Despite considerable differences between FVA and FVP pathological erythropoiesis, no qualitative discrepancies are observed between the population sizes and the differentiating abilities of the pluripotential stem‐cell compartment. The increase in number of CFU appears to be incidental to the oncogenic action of the virus at the level of the erythroid precursor cells.
Abrogation of cell‐mediated immunity by hyperimmune alloantiserum: Mechanisms and correlation with allograft enhancement
Authors: Cohen James M. , Yang Stringner S. , Law Lloyd W. 
Published: February 2007

AbstractAlloantiserum blocking of cell‐mediated immunity as measured by a 51chromium release cell‐mediated cytotoxicity assay has been characterized and correlated with immunological enhancement of tumor allografts across H‐2 barriers in mice. Alloantiserum blocking was found to be immunologically specific, quantitative, and highly reproducible. Cytotoxicity could be blocked by adding alloantiserum directly into the reaction mixture or by pretreating the target cells with alloantiserum. Effector cells could also be specifically blocked by pretreatment with alloantigens or with a fraction isolated from a mixture of alloantiserum and ascitic fluid containing alloantibody. Pretreatment of effector cells with alloantibody alone had no blocking effect. Upon purification, this fraction dissociated into IgG and a small molecular species with some biochemical and antigenic properties analogous to H‐2 fragments. These observations are consistent with the hypothesis that the isolated fraction may have been an antigen‐antibody complex consisting of alloantibody and H‐2 alloantigen. In addition, blocking was shown to be surmountable under certain conditions by increasing the number of effector cells. The implications and mechanism of alloantiserum blocking and its relationship to immunological enhancement are discussed.
Evidence for virus‐specific transplantation antigen in cells of lymphoid neoplasms induced by papovavirus sv40
Authors: Tevethia S. S. 
Published: February 2007

AbstractHamster lymphocyte leukemia and lymphosarcoma induced in vivo by papova‐virus SV40 were tested for the presence of SV40‐specific transplantation antigen. The cells derived from lymphocytic leukemia (GD‐248) blocked primary SV40 oncogenesis in vivo and also immunized adult hamsters against the transplantation of SV40 tumor cells which have been shown to carry SV40‐specific transplantation antigen. Lymphosarcoma cells (GD‐36), although immunosensitive, were not effective in blocking SV40 oncogenesis. GD‐36 cells were also less immunogenic than GD‐248 cells. These results indicate that the appearance of lymphoid cell tumors in adult hamsters by SV40 is not due to the absence of SV40‐specific transplantation antigen in these tumors.
Disappearance of a major cell‐type specific surface glycoprotein antigen (SF) after transformation of fibroblasts by rous sarcoma virus
Authors: Vaheri Antti , Ruoslahti Erkki 
Published: February 2007

AbstractNormal chick fibroblasts are known to contain a tissue‐specific surface component, a major glycoprotein (SF) antigen that is also present in chicken serum. This antigen was greatly reduced in amount or absent in fibroblasts transformed by five different Rous sarcoma virus strains. Fibroblasts infected with virus mutants temperature sensitive for transformation recovered the SF antigen when maintained at the non‐permissive temperature. Productive infection with a non‐transforming avian type‐C virus did not alter the level of SF antigen characteristic of normal fibroblasts. Polyacrylamide gel electrophoresis of total cell extracts indicated that proteins with apparent mol. wt. of 145,000 and mol. wt. 210,000 were greatly decreased following transformation of the fibroblasts. That the ability to synthetize the 145,000 mol. wt. polypeptide was lost upon transformation was implied by pulse labelling experiments, in which normal fibroblasts incorporate [35S] methionine into the above polypeptide whereas transformed cells lose this ability. This polypeptide, unique in its presence in normal but not in transformed cells, appears to have an exceptionally high rate of turnover. Indirect evidence suggests that the 145,000 and 210,000 polypeptides are molecular counterparts of the SF antigen. The transformation‐associated change in the quantity of the SF molecule supports our proposal that tissue‐specific surface glycoproteins, such as the SF antigen, express the stage of differentiation at the membrane of normal cells and may be involved in intercellular control of growth and movement.
Control of tumor growth in mice by thoracic duct drainage: Relationship to blocking factor in lymph
Authors: Noonan Frances P. , Gardner M. A. H. , Clunie G. J. A. , Isbister W. H. , Halliday W. J. 
Published: February 2007

AbstractTumor‐specific blocking factors were detected by the macrophage migration inhibition technique, in thoracic duct lymph collected 24 to 48 h after transplantation of two methylcholanthrene‐induced tumors into mice. Drainage of lymph in this period, with replacement of the cells, inhibited subsequent tumor growth. Blocking factor was not found in lymph from mice with a third tumor, when examined at the same stage, and thoracic duct drainage did not affect tumor growth in this instance. The results indicate that blocking factor has a function in vivo and that decreasing its concentration in a tumor‐bearing host at a critical stage can suppress tumor growth.