bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interaction between cellular and viral genes in the expression of the RSV‐induced transformation‐specific cell‐surface antigen VCSA
Authors: Prat Maria , Tato Franco , Tarone Guido , Comoglio Paolo M. 
Published: February 2007

AbstractTransformation of BHK hamster fibroblasts by an env strain of Rous sarcoma virus (RSV) leads to the appearance at the cell surface of a virus‐induced nonvirion antigen (VCSA), specific for transformation, whose expression is controlled by the transforming src gene. Previous work has shown that a rabbit anti‐VCSA serum lyses specifically, in the presence of complement, 51Cr‐labelled RSV‐transformed cells from different animal species. Now, by competition experiments with a panel of different unlabelled cells we show that the VCSA expressed on RSV‐transformed hamster fibroblasts is a complex of at least three distinct antigenic specificities: (1)one expressed on all RSV‐transformed fibroblasts, regardless their species and the subgroup or strain of the transforming virus; (2) one cross‐reacting with a cell‐surface antigen (CSA) expressed at various degrees on untransformed avian fibroblasts, but not on mammalian fibroblasts; (3) one species‐specific, present only on RSV‐transformed hamster fibroblasts. It is concluded that VCSA is a complex of several antigenic determinants, and that some of these differ in different cells transformed by RSV. This observation indicates that VCSA expression at the cell suface is likely to be the result of the interaction between the viral src gene product pp60src with host cell gene(s) or gene product(s), rather than the simple expression of this molecule at the cell surface.
Collaboration between specific anti‐tumor immunity and chemotherapeutic agents
Authors: Yamamura Yasuhiro , Proctor Julian W. , Fischer Beth C. , Harnaha Jo B. , Mahvi Thomas A. 
Published: February 2007

AbstractTreatment of DBM/2J mice bearing a T1699 syngeneic mammary adenocarcinoma (Ts) with a single intraperitoneal (i.p.) injection of 100 ug melphalan produced complete tumor regression in about 65% of the animals treated; however, tumors recurred in about 85% of these regressors after 15–22 days' remission. The drug regimen was ineffective against Ts tumors growing in immunosuppressed or immunodeficient animals. Stimulation of immunologically intact Ts tumor‐bearers with bacterial lipopolysaccharide (LPS) or with phytohemagglutinin (PHA) 3 days prior to melphalan therapy, on the other hand, produced not only higher rates of tumor regression but also significant increases in the number of permanent cures. A tumor induced by T1699 subline TR2 was resistant to the same regimen, although Ts and TR2 cells were equally susceptible to the cytotoxic and growth‐inhibiting activities of the drug in vitro. In contrast, the combination of specifically armed monocytes and melphalan in vitro produced enhanced killing of Ts cells but not of TR2 cells. Analysis of the collaborative cytotoxicity between immune effector cells and melphalan indicated that exposure of tumor cells to killer cells increased the drug susceptibility of the tumor cells, but not the reverse. These results suggest a possible mechanism for in vivo resistance of tumors to chemotherapeutic agents that is not directly associated with the drug resistance of the tumor cells in vitro.
Response to chemotherapy of human, malignant melanoma xenografts in athymic, nude mice
Authors: Fodstad Øystein , Aass Nina , Pihl Alexander 
Published: February 2007

AbstractIn attempts to elucidate the factors determining individual differences in response of tumors to chemotherapeutic agents, the sensitivity of six human malignant melanomas growing in athymic, nude mice was studied. Six agents, viz. DTIC, CCNU, vinblastine, procarbazine, as well as the toxic lectins abrin and ricin, were administered in maximum tolerable doses to the tumor‐bearing mice. The response to treatment was expressed as tumor growth delay, i.e. the number of volume doubling times saved by the treatment. The xenografts had very nearly retained the morphology of the parent tumors and were histologically similar. They showed different and characteristic early growth rates and also wide variations in their response to the agents tested. Unexpectedly, in the case of DTIC, CCNU and procarbazine, the response of the xenografts proved to be inversely related to the early growth rates of the tumors. For vinblastine, abrin and ricin, no correlation between response and growth rate of the tumors was apparent. Procarbazine had the best overall effect among the agents here tested. DTIC, CCNU and vinblastine had somewhat less and about equal overall efficiency. The plant toxin abrin, which acts by inhibiting protein synthesis, was at least as effective as DTIC. When abrin was given together with DTIC, the effect on the two xenografts tested was superior to that of each agent given alone. The wide variations observed in the response of the histologically similar xenografts to the different agents demonstrate that testing of the chemosensitivity of human xenografts requires the use of a panel of tumors of each histological type. The clear relationship found between the early growth rate of the xenografts and their sensitivity to three of the drugs most commonly used in the treatment of malignant melanomas, may have clinical implications.
Elevation of serum polyamines in malignant lymphomas and acute myeloid leukemia
Authors: Hospattankar A. V. , Advani S. H. , Vaidya N. R. , Electricwalla S. E. , Braganca Beatriz M. 
Published: February 2007

AbstractIn a study of 89 cases of hematological cancers including 55 cases of Hodgkin's disease, 21 of non‐Hodgkin lymphoma and 13 of acute myeloid leukemia, the serum total polyamines were considerably elevated (1.2–5.7 nmol/ml) as compared to observations on control values for eight healthy individuals (0.62–0.87 nmol/ml). The assay procedure was based on enzymes oxidizing polyamines isolated from Russell's viper venom. Serial determination of polyamines in the sera of eight cases of Hodgkin's disease done before and after chemotherapy or radiotherapy showed positive correlation with clinical status of the disease. Analysis of individual polyamines in four patients with Hodgkin's disease indicated that putrescine may be a more sensitive marker of the diseased state. By the present method it was undetected in the control sera but rose significantly in the sera of patients with Hodgkin's disease. Overall data suggest that serum polyamines may be useful as indicators of onset of relapse in patients with Hodgkin's disease and could thus be helpful in early start of treatment.
Subcellular distribution of simian virus 40 T antigen species in various cell lines: The 56K protein
Authors: Luborsky Samuel W. , Chandrasekaran K. 
Published: February 2007

AbstractThe subcellular distribution of SV40 anti‐T serumspecific species was examined in SV40‐transformed, Tantigen‐positive tissue culture cell lines of rat and of AL/N and BALB/c mouse origin. Cells were labelled with [35S]methionine. The cytoplasm, nuclear and membrane fractions were obtained, and their radioimmunoprecipitates analyzed by gel electrophoresis. Tests were performed to determine the purity of these subcellular fractions, and negligible cross‐contamination was found. The cytoplasm fractions lacked detectable anti‐T serum reactivity. Large amounts of both large T antigen and a 56K protein were always present together both in the nuclear fractions and, in a somewhat lesser amount, in the plasma membrane fractions of all cell lines examined. Analysis of density gradient sedimentation profiles of the immunoprecipitates of whole‐cell extracts indicated these species were associated in some fashion, probably with each other. The activity of the 56K protein may be associated with its presence on the cell surface where, either alone or acting together with the large T antigen, it might provide the surface activity responsible for tumor‐specific surface and/or traneplantation antigen activities.
Non‐T‐cell‐mediated cytotoxicity in MSV tumor‐bearing mice. III. Macrophage‐mediated cytotoxicity against autochthonous MSV tumor‐isolated target cells
Authors: Becker Susanne , Haskill Stephen 
Published: February 2007

AbstractCytotoxic macrophages have been isolated Moloney sarcoma virus (MSV) tumors induced in uncompromised, immunosuppressed and athymic nude mice. Macrophages from compromised mice were least as active as those from uncompromised mice when tested against the autochthonous MSV target cells. Although both cytolytic and cytostatic activity could demonstrated with all tumor‐derived macrophages, cytostatic and cytolytic effects could be distinguished from each other only at high effector target‐cell ratios. A variety of target cells were compared for sensitivity to various tumor‐associated macrophages. The auto chthonous virus‐infected MSV‐target cells appeared be more sensitive to the macrophage effects than fast growing, established cell lines. Normal embryo fibroblasts were only slightly affected. Peritoneal exudate cells from tumor‐bearers were much less active than either the tumor‐isolated macrophages or bone‐marrow culture‐derived macrophages. Both were more active than control peritoneal cells. Although no quantitative or qualitative differences in macrophage activity could be detected in mice with regressing lesions immuno‐compromised mice with progressing lesions, the ratio of macrophages to «sarcoma» cells was three to five times higher in regressing tumors.
Establishment in continuous culture of a T‐lymphoid cell line (HD‐Mar) from a patient with Hodgkin's lymphoma
Authors: Ben‐Bassat Hannah , Mitrani‐Rosenbaum Stella , Gamliel Haim , Naparstek Elizabeth , Leizerowitz Rachel , Korkesh Aviva , Sagi Michal , Voss Ruth , Kohn Gertrude , Polliack Aaron 
Published: February 2007

AbstractA new cell line, HD‐Mar, was established from a pleural effusion of a patient with Hodgkin's lymphoma. Formation of E rosettes, sensitivity to anti‐T serum, elevated terminal deoxynucleotidyl transferase activity, presence of T‐cell and the common ALL membrane antigens, morphology, and cytochemical staining indicate that the HD‐Mar line is of thymic derivation. Absence of any immunoglobulin determinants, the lack of EBNA or any other EBV‐associated antigen or function are also characteristics associated with established T‐ cell‐derived lymphoma cell lines. Karyotype analysis indicated a tetraploid origin of the cell line.
Partial characterization of viral DNA from human genital warts (condylomata acuminata)
Authors: Gissmann Lutz , Hausen Harald Zur 
Published: February 2007

AbstractBy centrifuging total cellular DNA derived from human genital warts (condylomata acuminata) in CsCI‐ethidium bromide gradients, supercoiled DNA was isolated. The molecular weight of this DNA was determined by agarose gel electrophoresis and amounted to 5.1 × 106. This DNA isolated from an individual genital wart was annealed to fractions of aqueous supernatants of the same wart after prior centrifugation of this material in CsCI density gradients. Annealing was observed at a density of approximately 1.32 g/ml corresponding to the expected density of papilloma virus particles. Since such particles were also observed in the same preparation by electron microscopy, it was concluded that the supercoiled DNA molecules were derived from papilloma virus nucleocapsids. Positive hybridization was found with six additional preparations from individual genital warts. Therefore, it seems that the isolated DNA prevails in condylomata acuminata. The DNA is different from the other five types of human papilloma viruses described thus far in regard to its restriction endonuclease cleavage patterns. The virus analyzed is tentatively designated as human papilloma virus type 6 (HPV 6).
Killing of normal cells by activated mouse natural killer cells: Evidence for two patterns of genetic regulation of lysis
Authors: Kiessling Rolf W. , Welsh Raymond M. 
Published: February 2007

AbstractNormal primary mouse thymocytes and peritoneal cells are sensitive for lysis by mouse spleen cells activated by in vivo infection with lymphocytic choriomeningitis virus (LCMV). With both thymocytes and peritoneal cells as targets, the active killer cell seemed to be an NK cell, as judged by high activity in the mouse mutant nude and low activity in the mouse mutant beige. Thymocytes from 1‐ to 3‐week‐old mice were found to be most NK‐sensitive, while peritoneal cells showed highest sensitivity for lysis when harvested from older (6‐ to 8‐week‐old) animals. In a direct comparison the genetic regulation of NK activity against thymocytes and peritoneal cells was analyzed. The same strain origin of both target cells and effector cells in either system was used. With thymocytes as target cells, spleen cells from LCMV‐infected C3H/St mice invariably showed the highest activity closely followed by cells from the BALB/c strain, while the SWR/J and the A/J strains both were considerably less reactive. The same pattern of high‐ or low‐reactive strains was seen regardless of the genotype of the thymocyte target donor, and the same pattern of cytotoxicity was also seen against the YAC‐I lymphoma target. An entirely different genetic regulation was active in the lysis of peritoneal cells, where a unique pattern of reactivity was seen for each effector cell genotype, dependent on the strain origin of the peritoneal target cell. In line with previous findings, syngeneic combinations of effector‐target cells yielded little or no reactivity, while various allogeneic combinations showed considerable levels of activity. Also, primary cultures of embryonic fibroblasts were used as target cells. The genetics of the fibroblast target system was more similar to that seen in the thymocyte‐YAC‐I assay since no evidence for a preferential killing of allogeneic target cells was seen.
Isolation of a series of novel variants of murine mammary tumor viruses with broadened host ranges
Authors: Howard David K. , Schlom Jeffrey 
Published: February 2007

AbstractWe have previously isolated mouse mammary tumor virus (MMTV) host range variants by serial virus passage in feline cells. These variants productively infect cells of a broad range of species but replicate most efficiently in feline cells. We report here the isolation of a series of novel MMTV host range variants that have the ability to replicate with high efficiency in murine, rat, canine and human cells, respectively; these variants were isolated by serial virus passage in cells of each respective species. These new variants, furthermore, all retained their ability to efficiently replicate in feline cells, and each exhibited unique host range properties. The novel MMTV variants obtained from murine, rat, feline, canine, and human cells showed no overt evidence of recombination with endogenous type‐C viruses in that they retained their antigenic reactivities in group‐specific radioimmunoassays for MMTV polypeptides, and were unreactive for type‐C virus proteins when tested by radioimmunoassays and DNA polymerase assays. These novel MMTV host range variants now broaden the spectrum of studies that can be undertaken involving MMTV replication and the initiation and promotion of virus‐mediated mammary cell transformation.
Potential diagnostic and prognostic significance of the transformation‐enhancing factor(s) in the plasma cryoprecipitate of tumor patients
Authors: Mignatti Paolo , Ascari Edoardo , Barlati Sergio 
Published: February 2007

AbstractA biological activity which enhances cell transformation (TEF) in Rous sarcoma virus temperature‐sensitive mutant‐infected cultures has been evidenced in the plasma cryoprecipitate from patients affected with different types of neoplastic disease. In the present paper we report data on the analysis of TEF activity in the plasma cryoprecipitates from leukemic and tumor patients tested either before or during specific antineoplastic treatments. The screening of 57 cases of different neoplastic diseases and of 57 controls, healthy subjects or patients affected with other non‐neoplastic diseases indicates that TEF activity is generally related to the presence of neoplasia. Furthermore, a follow‐up of patients from the onset of the disease through its evolution during therapy suggests that variations of TEF activity in the plasma cryoprecipitate correlate well with the clinical and pathological conditions, thus indicating the TEF as a potential marker for monitoring cancer patients.
Circulating immune complexes in patients with bone tumours
Authors: Eiras Amada Segal , Robins R. A. , Baldwin R. W. , Byers V. S. 
Published: February 2007

AbstractSera from 62 patients with osteogenic sarcoma and 12 with malignant giant‐cell tumour were tested for the presence of immune complexes by the 125I‐Clq binding assay. Elevated serum Clq binding activity was found in 67.7% of the osteogenic sarcoma patients and in 75% of the giant‐cell tumour patients. These results were compared with those obtained with five sera from patients with benign bone tumours and 20 sera from normal young donors. In the last two groups, the incidence of elevated Clq‐binding activity was 0% and 5%, respectively. In some patients with giant‐cell tumours, preand post‐operative serum samples were studied, showing a decrease in test values after tumour resection. Preliminary sequential studies of individual patients indicate that the 125I‐Clq binding assay may be useful for monitoring patients with bone tumours.
Kaposi's sarcoma and its relationship to cytomegalovirus (CMV) III. CMV DNA and CMV early antigens in Kaposi's sarcoma
Authors: Giraldo G. , Beth E. , Huang E.‐S. 
Published: February 2007

AbstractDNA‐DNA reassociation kinetics, anti‐complement immunofluorescence (ACIF) and ACIF‐blocking tests were used to search for cytomegalovirus (CMV) gene products in Kaposi's sarcoma (KS) biopsies and early cell cultures deriving from them. Three of eight tumor biopsies were positive for CMV DNA; two of them at 0.35 genome/cell and one at one copy of 25% genome/cell. CMV‐related antigens, mainly localized in the nucleus, were found in cryostat sections of seven of 31 tumor biopsies and four of 12 KS cell lines at early passage level. It appears that the antigen is present in a high number of tumor cells, like the Epstein‐Barr virus nuclear antigen (EBNA) in EBV‐transformed cells. Inevitably, the increasing data concerning the oncogenic potential of CMV lead on to consideration of the increasing evidence of its association with Kaposi's sarcoma, a multiple hemorrhagic sarcoma with an epidemiologic distribution in Africa similar to that of Burkitt's lymphoma.
Chromosome abnormalities, clinical and morphological manifestations in metamorphosis of chronic myeloid leukemia
Authors: Oläh Éva , Kiss Attila , Jakq János 
Published: February 2007

AbstractSeventeen cases of chronic myeloid leukemia (CML) in metamorphosis have been investigated by cytogenetic methods. Six patients were studied in slow transformation and others in the terminal blastic phase of the disease. Of these, 3 cases were myeloid, 3 myelomonocytic, I megakaryoblastic, I promyelocytic and 4 lymphoid in their morphological and cytochemical appearance. Some correlation could be observed between the clinical, morphological, cytochemical and cytogenetic findings of the different subgroups. The results demonstrate the importance of chromosome investigations in the early diagnosis of metamorphosis and in distinguishing the different subgroups of the terminal stage of CML.
Effect of the intermittent administration of N‐nitrosopyrrolidine (NPYR) on the tumor incidence in Sprague‐Dawley rats
Authors: Habs M. , Habs H. , Schmähl D. 
Published: February 2007

AbstractN‐Nitrosopyrrolidine (NPYR) was administered orally to 320 Sprague‐Dawley rats. An additional group of 80 rats served as an untreated control. There were four experimental groups in which the effects of different periods of dosing and varied intervals without treatment were compared. The total dose for all the groups was constant and was 792 mg/kg body weight. The schedules of carcinogen application had a significant effect on the observed cancer risk. The different tumor indicences in the individual groups could not be attributed to differences in the survival pattern, but were related to the changes in the different treatment schedules.
Cytolytic activity against tumor cells by macrophage cell lines and augmentation by macrophage stimulants
Authors: Taniyama Tadayoshi , Holden Howard T. 
Published: February 2007

AbstractPrevious studies have shown that macrophage cell lines retained the ability to phagocytize, to secrete lysosomal enzymes, and to function as effector cells in antibody‐dependent cellular cytotoxicity. In this paper, the cytolytic activity of murine macrophage cell lines against tumor target cells was assessed using an 18‐h 51Cr release assay. Of the macrophage cell lines tested, RAW 264, PU5‐1.8 and IC‐21 had intermediate to high levels of spontaneous cytolytic activity, P388D1 and J774 had low to intermediate levels, while WEHI‐3 showed little or no cytolytic activity against RBL‐5, MBL‐2 and TU‐5 target cells. Tumor‐cell killing by macrophage cell lines could be augmented by the addition of macrophage stimulants, such as bacterial lipopolysaccharide and poly I:C, indicating that the activation of macrophages by these stimulants does not require the participation of other cell types. Treatment with interferon also augmented the tumor‐cell killing by macrophage cell lines. Although the mechanism by which these cell lines exert their spontaneous or boosted cytotoxic activity is not clear, it does not appear to be due to depletion of nutrients since cell lines with high metabolic and proliferative activities, such as WEHI‐3 and RBL‐5, showed little or no cytotoxicity and supernatants from the macrophage cell lines did not exert any cytotoxic effects in their assay. Thus, it appears that the different macrophage cell lines represent different levels of activation and/or differentiation and may be useful for studying the development of these processes as well as providing a useful tool for analyzing the mechanisms of macrophage‐mediated cytolysis.
FV‐2r‐mediated resistance of mouse bone‐marrow cells to friend spleen focus‐forming virus infection
Authors: Yoosook Chalobon , Steevesz Richard , Lilly Frank 
Published: February 2007

AbstractA target cell assay based on the formation of infectious centers (IC) was used to characterize the Fv‐2resistance gene of mice. Dose‐response curves were obtained for the number of IC generated from incubated mixtures of bone‐marrow cells and Friend virus (FV). The hemopoietic stimulus of bleeding increased the frequency of potential 〈target〉 cells capable of forming 1C in DBA/2 but not in D2.Fv‐2r mice; however, even without the bleeding stimulus D2.Fv‐2r mice contained fewer target cells in their bone marrow than DBA/2 mice. During the first 48 h postinfection a massive dose of FV overcame the inhibitory effect of the FV‐2r gene as measured by the release of FV from the spleen. However, the concentration of 1C recoverable from the spleens of these infected mice was still much lower in the D2.Fv‐2r strain. When irradiated F1 hybrid hosts were used as recipients for the proliferation of infected donor cells, splenic 1C were not generated as efficiently from infected bone‐marrow cells of D2.Fv‐2r origin as from those of DBA/2 origin. However, the amounts of SFFV recoverable were approximately the same. Similarly, after in vitro infection there was no great difference between the amounts of SFFV released from bonemarrow cells of DBA/2 and D2.Fv‐2r mice. We conclude that the primary effect of the Fv‐2r gene may be to inhibit the formation and proliferation of 1C in vivo, and that SFFV replication could be inhibited secondarily.