bluuebunny/crossref_metadata_2025 huggingface dataset:
Antibody to Epstein‐Barr virus in man in Australia and New Guinea
Authors: Pope J. H. , Walters Marilyn K. , Scott W. , Gunz F. W.
Published: February 2007

Antibody to EB virus was assayed in 586 sera from several populations in Australia and New Guinea and from leukaemic and control groups. The prevalence of antibody to EB virus in a normal population in Brisbane increased gradually from about 31% in 1‐ to 5‐year‐olds to about 90% in adults. A similar age distribution occurred in a population from Griffith, N.S.W. In contrast, all 1‐ to 5‐year‐old Aboriginal children from the west coast of Cape York Peninsula and from New Guinea had antibody to EB virus, indicating a high rate of infection in early life. Aborigines from the east coast of Cape York Peninsula had a slightly lower prevalence. The geometric mean (GM) titres of 63 leukaemic cases from Sydney (1:72) and of 60 non‐leukaemic hospital patients (1:80) were not significantly different, but each was significantly higher than that (1:44) of 57 normal controls from Griffith. No association was found between the degree of remission in 29 cases of acute myeloid leukaemia and either the presence of antibody to heat‐labile EB viral complement‐fixing antigen or the titre of antibody to viral capsid antigen, or to crude or soluble EB viral complement‐fixing antigens. The significantly higher GM antibody titres in non‐leukaemic patients and in Aboriginal children with non‐malignant diseases suggest that some pathological process common to a variety of diseases results in moderately increased titres of antbody to EB virus.
Carcinogenicity of nitrosamines and methanesulphonate esters given intraperitoneally, in RF mice
Authors: Clapp N. K.
Published: February 2007

Single injections of dimethylnitrosamine (DMN), diethylnitrosamine (DEN), methyl methanesulfonate (MMS), and ethyl methanesulphonate (EMS) were given intraperitoneally to male RF mice at various doses. DEN induced lung adenomas, liver hepatomas and forestomach tumors (squamous‐cell carcinomas and papillomas) at all doses, and Leydig‐cell tumors of the testis at the highest dose given. DMN, while increasing lung tumor incidence, failed to induce liver tumors when given intraperitoneally —in contrast to high incidences obtained by oral administration. The reason for this difference is not obvious at this time. MMS and EMS were not carcinogenic as used in this study. None of these alkylating agents was leukemogenic.
Studies on mouse sarcoma virus. IV. The isoelectric point of the group‐specific antigen
Authors: Chuat J. C. , Bernard C. , Laprevotte I. , Seban C. , Boiron M.
Published: February 2007

At least three classes of species‐specific, group‐specific (gsl) antigen‐bearing molecules were separated by isoelectric focusing of tween‐ether disrupted Moloney strain mouse sarcoma virus (M‐MSV) derived from a permanent producer rat cell line (78 A1). The bulk of gs1 antigen, as measured by complement‐fixation, was associated with a 3H‐uridine‐labelled component characterized by an isoelectric point (ip H) of 5.9 and a sedimentation coefficient of 2.7 Sw, 20 Statistical evaluation showed the ipH value to be remarkably stable. Neither ipH nor content of 3H‐uridine‐label was altered by ribonuclease (RNase), in contrast to an ipH 5.0 component found occasionally. The other gs1 antigen‐bearing molecules were only minor components and included an RNase‐resistant, ipH 5.5 component, frequently observed as a shoulder on the major peak, and an inconstant, poorly labelled component with a more variable ipH value of about 6.6. The significance of these findings is discussed in view of previous reports on the subject and of recent information regarding the structure of murine tumor viruses.
Binding of metabolites of dietary 4‐dimethyl‐aminoazobenzene and 2‐methyl‐4‐dimethylamino‐azobenzene to rat liver DNA and protein of subcellular fractions
Authors: Chauveau Jean , Meunier Michèle , Benoit Annie
Published: February 2007

The binding of metabolites of two related azo dyes of different carcinogenic potency, the carcinogenic 4‐dimethylaminoazobenzene (DAB) and the weakly carcinogenic 2‐methyl‐4‐dimethylaminoazobenzene (2‐Me‐DAB), to rat liver DNA and to subcellular fraction protein was studied following chronic oral administration for 1 to 3 weeks. Different techniques for measuring the amount of DAB metabolites bound to protein were first compared, then the whole study was performed with labelled DAB and 2‐Me‐DAB (aniline ring‐14C) of moderate specific activity. DAB metabolites were bound to liver DNA to a higher extent than those of 2‐Me‐DAB. In contrast, the binding of 2‐Me‐DAB metabolites was equal to or higher than that of DAB metabolites to protein. The amount of protein‐bound metabolites was studied on the nucleo‐mito‐chondrial fraction, microsomes, supernatant, nuclei, chromatin, nucleoplasm, nucleolar fraction and nuclear membrane. Following the administration of both dye diets, the supernatant protein bound the highest level of metabolites. The time‐course of binding of DAB metabolites to DNA and protein was different from that of 2‐Me‐DAB metabolites. These results show the possible involvement of carcinogen‐DNA binding in the mechanism of carcinogenesis.
The cellular events associated with regression and progression of murine (moloney) sarcomas
Authors: Russell Stephen W. , Cochrane Charles G.
Published: February 2007

Tumors were induced in adult and neonatal mice by intramuscular injections of either 104 or 106 cells from a cultured murine (Moloney) sarcoma line. Neoplasms that progressed were induced in neonates by either dose, and in adults only by the larger dose; adult mice receiving 104 cells usually developed tumors that regressed. Light microscopic examinations were performed at 2–3 day intervals throughout the course of tumor development and subsequent regression or progression. Initially all tumors became infiltrated with polymorphonuclear leukocytes—mainly neutrophils—and edema was extensive. By the end of the second week post inoculation, this acute inflammatory infiltrate had been replaced in adult mice by one consisting of mononuclear cells; neonatal mice never developed significant numbers of these inflammatory cells in their tumors. Of particular significance, since mononuclear inflammatory cells were associated intimately with tumors during the process of regression, was the disappearance of these cells 12–14 days post inoculation from tumors destined to progress in adult mice. Hyperplastic changes were found in the cortices and medullae of regional lymph nodes draining both progressing and regressing sarcomas. Secondary neoplasms developed commonly, and the distribution of these lesions was related to the ages of mice at the time of inoculation.
RNA‐dependent DNA polymerase associated with a simian lymphoid cell line derived from a Herpesvirus saimiri‐induced lymphoma
Authors: Yang Stringner S. , Ablashi D. , Armstrong G. , Ting R. C.
Published: February 2007

This communication describes the spontaneous appearance of a membrane‐bound RNA‐dependent DNA polymerase in a simian lymphoma cell line that was established from a lymphoma tumor mass previously induced by Herpesvirus saimiri in an owl monkey. This membrane‐bound RNA‐dependent DNA polymerase fraction possesses many biochemical properties analogous to those of known primate and murine RNA tumor viruses. Characteristics of this RNA‐dependent DNA polymerase are clearly distinct from those of the DNA polymerase of Herpesvirus saimiri. This particular fraction incorporates tritiated ribonucleosides into RNA in an in vitro system, and it sediments at 1.15–1.16 g/cm3. It is not induced to greater production by halogenated deoxyuridines. The current observations were made at a time when the host cells were no longer producing Herpesvirus saimiri.
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

Adult 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

A 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

The 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

Immunization 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

In 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

An 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

The 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

Cell 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

Subcellular 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

Oncornavirus‐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

Oncornavirus‐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

The 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

Alpha‐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

The 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

The 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

A 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

A 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

Alloantiserum 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

Hamster 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

Normal 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

Tumor‐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.
Attempts to detect virus‐specific DNA in human tumors. I. Nucleic acid hybridizations with complementary RNA of human wart virus
Authors: Hausen Harald Zur , Meinhof Wolf , Scheiber Wiltrud , Bornkamm Georg W.
Published: February 2007

Human wart virus was isolated from plantar warts. After extraction of its DNA, component I was transcribed into radioactive complementary RNA (cRNA) with the aid of Escherichia coli RNA polymerase. The resulting cRNA annealed specifically to wart viral DNA and was used as a probe for the detection of wart viral DNA in human warts, condylomata acuminata, laryngeal papillomas and some malignant human tumors. High concentrations of hybridizing DNA were found in plantar warts. Verrucae vulgares annealed to a considerably lower extent only, indicating that very few genome equivalents were present in those papilloma cells. Some verrucae vulgares were found to be completely negative in this test. Condylomata acuminata, as well as laryngeal papillomas and all malignant tumors tested, did not hybridize with wart viral cRNA.
Genetic control of susceptibility to 3‐methylcholanthrene‐induced subcutaneous sarcomas
Authors: Kouri Richard E. , Ratrie Harry , Whitmire Carrie E.
Published: February 2007

Using a genetic system in which aryl hydrocarbon hydroxylase (AHH) inducibility segregates, it was observed that inducible mice are approximately 12 times more sensitive to 3‐methylcholanthrene‐induced tumorigenesis than their non‐inducible littermates. The type of parental cross (maternal influence) plays no role in this sensitivity. Hostregulated expression of the group‐specific (gs) antigen of type‐C RNA viruses, although also segregating in this genetic system, does not seem to play a major role in this enhanced susceptibility to 3‐methylcholanthrene carcinogenesis. Results are discussed with the view that the enhanced sensitivity of the AHH‐inducible animals probably results from rapid and efficient metabolism of the chemical to its ultimate carcinogenic form.
Radiation‐killed BCG in the treatment of transplanted rat tumours
Authors: Baldwin R. W. , Cook A. J. , Hopper D. G. , Pimm M. V.
Published: February 2007

Growth of syngeneic transplants of methylcholanthrene‐induced sarcomas and an aminoazo‐dye‐induced hepatoma in rats was suppressed when tumour cells were injected in admixture with BCG vaccine containing living organisms, or vaccine sterilized by exposure to 1 to 3 × 106 R γ‐irradiation. Rejection of mixed inocula containing viable or radiation‐killed BCG induced immunity to further challenge with tumour cells. Also pulmonary tumour growth produced by intravenous injection of sarcoma cells was controlled by intravenous injection of living or radiation‐killed BCG. These studies indicate that radiation‐sterilized preparations may replace viable vaccine in immuno‐therapy, at least where tumour suppression results from contact with BCG. The use of sterilized vaccine in comparable clinical situations would remove any danger of the generalized BCG infection which has recently been reported in patients receiving BCG immunotherapy.
Relationship between Epstein‐Barr virus (EBV) DNA and the EBV‐determined nuclear antigen (EBNA) in Burkitt lymphoma biopsies and other lymphoproliferative malignancies
Authors: Lindahl Tomas , Klein George , Reedman Beverley M. , Johansson Bo , Singh Surjit
Published: February 2007

Twenty‐six of 27 African Burkitt lymphomas with histologically confirmed diagnosis contained relatively large amounts of EBV DNA (10–101 viral genomes per cell), as determined by nucleic acid hybridization. Twenty‐five of the 26 EBV DNA‐positive lymphomas contained the EBV‐determined nuclear antigen, EBNA, in the majority of the nuclei. Technical reasons may have accounted for the apparent EBNA‐negativity of one EBV DNA‐positive biopsy. Four African lymphoma biopsies, one with a definite diagnosis of Burkitt's lymphoma and three with a questionable diagnosis of the same disease, were all EBV DNA‐ and EBNA‐negative. The same was true for a collection of Swedish cases of Hodgkin's disease, lymphocytic lymphoma, chronic lymphatic leukemia and some other lymphoproliferative malignancies. Thus, there is excellent agreement between the presence of EBV DNA and of EBNA in tumor biopsies. The EBNA antigen test therefore appears a relatively simple way of testing for the presence of the virus genome, provided it is carried out with appropriate controls. Several of the EBV‐genome and EBNA‐negative cases came from patients with high serum titers of EBV antibodies. It is concluded that the virus does not really travel along with malignant lymphomas as a passenger in the seropositive patients. In comparison with other lymphomas, African Burkitt's lymphoma of the high endemic areas is unique in that the tumors (with rare exceptions) represent the proliferation of an EBV‐genome carrying clone. These findings stress the necessity to distinguish between EBV‐seropositive status and evidence for EBV‐genome‐carrying neoplastic cells.
Detection of Epstein‐Barr virus (EBV)‐associated nuclear antigen in human lymphoblastoid cell lines by means of an 125I‐IgG‐binding assay
Authors: Brown T. D. K. , Ernberg I. , Lamon E. W. , Klein G.
Published: February 2007

The elution at low pH of human EBV‐positive 125I‐IgG bound to preparations of EBV‐carrying non‐producer lymphoblastoid cell lines has been investigated. Specific binding was demonstrated. A number of approaches were used to confirm the specificity. The stoichiometry of binding and elution was studied. The sub‐cellular location of the EBV‐associated antigen (s) detected by this method was shown to be predominantly nuclear. This confirms other studies demonstrating the presence of a nuclear antigen in non‐producer lymphoblastoid cell lines carrying the EBV genome.
Establishment and characteristics of two unique cell lines from patients with lymphosarcoma
Authors: Nilsson Kenneth , Sundström Christer
Published: February 2007

Two human cell lines, U‐698 M and U‐715 M, with unique characteristics were derived from two patients with lymphosarcoma. The presented morphological and functional characteristics closely resemble those of lymphosarcoma cells in short‐term culture and also distinguish both lines from Epstein‐Barr virus‐carrying lymphoblastoid lines obtainable from normal and malignant lymphoid tissue. It is therefore proposed that the lines originate from the donors' tumor‐cell population.
Circulating immune complexes in human neuroblastoma: Direct assay and role in blocking specific cellular immunity
Authors: Jose David G. , Seshadri R.
Published: February 2007

Eight children with neuroblastoma and five with Wilms' tumour, or osteogenic sarcoma, had serum taken at diagnosis (progressor sera) and again several weeks after the start of treatment (remission sera). Progressor sera, which specifically blocked in vitro, lymphocytotoxic immunity for autochthonous tumour cells, contained immune complexes of tumour‐specific antigen and antibody. Blocking progressor sera from five patients contained both complexes and free antigen, while maximum blocking activity was found in three progressor sera which contained complexes but neither free antigen nor free antibody. Remission sera contained neuroblastoma‐specific antibody which specifically bound antigenic protein spontaneously released from autochthonous tumour‐cell membranes in vitro, and also bound soluble antigen in progressor serum. Neuroblastoma‐specific immune complexes, formed by titration of autochthonous remission serum and membrane‐turnover antigen, produced maximum blocking of autochthonous lymphocytotoxic immunity at antigen‐antibody equivalence. Complexes formed in antigen excess showed moderate blocking activity while complexes formed in antibody excess showed minimal blocking activity. The ability of a malignant tumour to generate local or systemic excess of membrane‐derived antigen may assist successful escape from specific cellular immune destruction.
Analysis of papers in major cancer research journals
Authors: Honda Shinako
Published: February 2007

The following analysis was performed to investigate which, at the moment, are the main centers of cancer research from the international point of view. The criterion was the number of contributions to research papers in five leading cancer journals which are considered to have a high standard. The research reports in these five journals originated from many countries and can be regarded as being international. According to the results, USA is the leading country contributing with 70% of all the papers published in the five journals. However, it has to be noted that three of the five investigated journals are published in the USA. The countries which followed were England, Canada, France, Japan and Sweden, which together contributed 16% of the papers. The remaining 14% of the papers originated from 58 other countries.
Tumors formed by human rhabdomyosarcoma cells in chorioallantoic membrane of embryonated hens' eggs
Authors: McAllister R. M. , Peer M. , Gilden R. V. , Klement V. , Landing B. H.
Published: February 2007

Cultured human rhabdomyosarcoma (RD) cells were seeded on the chorioallantoic membrane of embryonated hens' eggs at the 10th to 12th day of incubation. When the membranes were harvested after 18 to 19 days' incubation, tumors had formed in eggs seeded with 5 × 105 to 10 × 106 RD cells. The microscopic appearance of the tumors was similar to that of the rhabdomyosarcoma of the patient from whom the cell line was derived. In contrast to cell lines derived from RD cell tumors which formed in a cat or an NIH‐Swiss mouse and released the endogenous viruses of the cat and mouse, respectively, none of 36 cell lines derived from 13 tumors formed on the chorioallantoic membrane of hens' eggs released a type‐C virus and none contained the avian virus group‐specific antigen.
Sensitization to tumour‐associated antigens in human breast carcinoma
Authors: Cochran A. J. , Grant R. M. , Spilg W. G. , Mackie R. M. , Ross C. E. , Hoyle D. E. , Russell J. M.
Published: February 2007

We have used the leukocyte migration technique to examine the leukocytes of 138 breast cancer patients and 157 control donors for sensitization to breast carcinoma associated antigens. A majority of breast cancer patients (54%) showed sensitization while only 15% of the control donors reacted. Reactions were as frequent with autologous combinations of antigen and leukocytes as with homologous combinations, suggesting that transplantation antigens are relatively unimportant in the system and that breast cancers share structurally similar antigens. Reactions were less frequent with leukocytes from patients who had visceral metastases; however, patients with local recurrences were as frequently reactive as those with localized disease. Extracts of mastopathic breasts and fibroadenomas infrequently inhibited the leukocytes of cancer patients and of control donors. Macroscopically normal breast from the tissue around breast cancers may contain antigens similar to the tumour‐associated antigens.
Enhancing effect of green monkey kidney cell extract on the transformation of mouse cells by SV40
Authors: Hagiwara Akio , Kitahara Tsunehiro
Published: February 2007

Extracts of green monkey kidney cells enhance the transformation of mouse cells by SV40. An enhancing activity is also detected in cell extracts from human embryonic lung, mouse embryo or hamster embryo cells. The activity of green monkey kidney cell extract is sensitive to trypsin, but not deoxyribonuclease, ribonuclease or heating at 56° C for 30 min. Since the extract has no effect on early events such as virus adsorption, penetration, uncoating and T antigen formation, the enhancing factor(s) may act on the other processes required for transformation.
Control of normal differentiation of myeloid leukemic cells. V. Normal differentiation in aneuploid leukemic cells and the chromosome banding pattern of D+ and D− clones
Authors: Hayashi Makoto , Fibach Eitan , Sachs Leo
Published: February 2007

A line of mouse myeloid leukemic cells in culture contained two types of clones. One type can be induced by the differentiation‐inducing protein MGI to undergo normal differentiation to mature macrophages and granulocytes (D+ clones), whereas the other type could not be induced to differentiate (D− clones). D+ clones can segregate some D− progeny and D− clones can segregate some D+ progeny. The segregant clones were more unstable in their ability to differentiate, than the stable parental clones from which they were derived. The chromosome banding pattern has been analyzed in 10 stable and six unstable clones. The clones had a modal chromosome number of 39, 40 or 41, and none of the clones, not even those with 40 chromosomes, showed a normal diploid banding pattern. Stable D+ and D− clones had different karyotypes. However, the banding patterns of the unstable D+ and D− segregants were not detectably different from the parental clones from which they were derived. The results indicate that normal differentiation can occur in aneuploid myeloid leukemic cells; that the initial segregation from D+ to D− and from D− to D+ was due to a hereditary change which did not show chromosome changes detectable by the banding technique; and that detectable chromosome changes were associated with hereditary stabilization of the difference between D+ and D−.
Segregation of the EBV‐determined nuclear antigen (EBNA) in somatic cell hybrids derived from the fusion of a mouse fibroblast and a human burkitt lymphoma line
Authors: Klein George , Wiener Francis , Zech Lore , Hausen Harald Zur , Reedman Beverley
Published: February 2007

Four independently derived hybrids between the mouse fibroblast line A9 and the human, Burkitt‐lymphoma‐derived lymphoblastoid cell line Daudi were studied for the presence of the Epstein‐Barr virus (EBV) genome, the EBV‐determined nuclear antigen (EBNA), other EBV‐associated antigens, human surface immunoglobulin and the presence of human chromosomes. The four lines differed in the number of their EBV genomes. There was a parallelism between this number, as detected by c/RNA/DNA hybridization, and the frequency of EBNA‐positive nuclei. None of the other EBV‐antigens, EA, VCA or MA, was expressed at any time, either in the untreated hybrid cells or after IUDR‐treatment. The hybrids did not carry detectable surface‐associated immunoglobulin or EBV‐receptors. The presence of the EBV genome was coincident with the maintenance of human chromosomes, but the hybrids that have lost detectable viral genomes and EBNA still contained a considerable number of human chromosomes, suggesting that the viral genome may be associated with a few chromosomes only.
Dual susceptibility of a 3T3 mouse cell line to infection by N‐ and B‐tropic murine leukemia virus: Apparent lack of expression of the FV‐1 gene
Authors: Gisselbrecht S. , Bassin R. H. , Gerwin B. I. , Rein A.
Published: February 2007

A murine sarcoma virus‐transformed S+L—3T3FL cell line has previously been shown to be equally susceptible to infection with both N‐ and B‐tropic variants of murine leukemia virus, unlike all other mouse cells so far described (Krontiris et al., 1973). Transformed S+L—‐BALB/3T3 and S+L‐ NIH/3T3 cell lines were isolated and were found to retain the same resistance to N‐ or B‐tropic viruses as that exhibited by their non‐transformed parent lines. This, coupled with the fact that normal, uninfected 3T3FL cells also show a dual susceptibility, indicates that the presence of the S+L—MSV genome is not responsible for the enhanced permissiveness. Clones of 3T3FL cells are themselves dually susceptible, indicating that this cell line is not simply a mixture of B‐ and N‐type cells. Apparently, the Fv‐1 gene, which is responsible for MuLV host‐range restriction in this system, is either missing or not expressed in 3T3FL cells. The enhanced susceptibility of normal and S+L—3T3FL cells makes these cell lines ideal for titrations of murine leukemia viruses and their MSV “pseudotypes”.