bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transformation of mouse cells infected with akr leukemia virus by benzene‐extract fractions of city air particles
Authors: Rhim J. S. , Gordon R. J. , Bryan R. J. , Huebner R. J. 
Published: February 2007

AbstractFractions of benzene extract of particles from city air have been studied for their transforming activity in the AKR leukemia‐virus‐infected NIH Swiss mouse embryo (AKR‐NIH‐ME) cell system. Mouse embryo cells chronically infected with AKR leukemia virus were transformed by benzene smog extracts, most of its fractions, and certain chemicals, whereas uninfected mouse embryo cultures were not transformed. Most of the transformed cells produced tumors when transplanted into newborn NIH Swiss mice. The three neutral fractions: AE0S2 (tetracyclics), AE0S3 (pentacyclics, including benzo(a)pyrene) and AE0S5 (unknown structural type) and two acid, phenol fractions, AE4 and AE4B, had the strongest transforming activity in vitro. One fraction, AE1B(CHCl3 back extract of water washes from AE1) appeared to be inactive in in vitro systems at the concentrations tested.
Reversible splenomegaly with low virus production induced in hyperimmune mice by parabiosis with friend‐virus‐infected mice
Authors: Takizawa Kiyoshi , Yoshikura Hiroshi , Sugano Haruo , Yamamoto Tadashi 
Published: February 2007

AbstractTen‐day parabiosis with Friend virus(FLV)‐infected mice induced marked splenomegaly in hyperimmune mice. Infectious center assay showed that only a small fraction of such proliferated spleen cells in the hyperimmune mice were virus producers. In the hyperimmune mice with splenomegaly, no suppression of primary immune response to sheep erythrocytes was induced by FLV infection. The splenomegaly of the hyperimmune mice regressed if the mice were separated from the FLV‐infected partners within 10 days of parabiosis. However, the prolongation of parabiosis in the hyperimmune mice caused an increase in virus‐producing cells, the suppression of primary immune response to sheep erythrocytes, persistent splenomegaly after separation from the FLV‐infected partners, and appearance of typical Friend cells in the spleen.
Expression of fetal antigens and tumor‐specific antigens in SV40‐transformed cells. II. Tumor transplantation studies
Authors: Ting Chou‐Chik , Rodrigues Dennis , Herberman Ronald B. 
Published: February 2007

AbstractThe effect of immunization with fetal antigens and tumor‐specific antigens on the transplantation of SVT2, a BALB/c mouse tumor induced by Simian virus 40 (SV40), has been studied. Hyperimmunization with 5,000 R X‐irradiated, syngeneic fetuses of 1–2 weeks' gestation or syngeneic spleen cells gave no protection to SVT2 cell challenge. In contrast, immunization with SV40 or SV40‐transformed cells gave a 100‐ to 1,000‐fold protection. These results gave additional evidence that fetal antigens are different from tumor‐specific transplantation antigen (TSTA).
Immunological studies of membrane glycoproteins isolated from human breast carcinomas
Authors: Kuo Tseng‐Tong , Rosai Juan , Tillack Thomas W. 
Published: February 2007

AbstractGlycoproteins were isolated from membrane preparations of human breast cancer using lithium di‐iodosalicylate followed by phenol partition as described for the isolation of CEA from colonic carcinoma. The glycoprotein isolated from breast cancer‐(BCGP) differed from colonic CEA in extraction yield, antigenicity, molecular weight on SDS acrylamide gel electrophoresis and on immunoelectrophoresis. Rabbit anti‐serum raised against BCGP and absorbed with red blood cells and normal breast tissue showed a reaction of identity on Ouchterlony immunodiffusion between BCGP and CEA. However, antiserum to CEA absorbed with red blood cells and normal colonic mucosa showed cross‐reaction of BCGP with CEA. The anti‐BCGP activity in anti‐CEA could be removed by absorption with BCGP, leaving activity directed only against CEA. Therefore, BCGP appears to be a CEA‐like antigen that shares antigenic determinants with CEA and may be responsible for the elevated radioimmunoassays for CEA in breast cancer patients. Whether there is a breast‐cancer‐specific antigen associated with the cell membrane remains to be demonstrated.
Mammary tumor virus (MTV) antigens in normal and mammary tumor‐bearing mice
Authors: Hilgers J. H. M. , Theuns G. J. , Van Nie Robertha 
Published: February 2007

AbstractQuantitative immunofluorescence tests were used to study MTV‐antigen production in normal and mammary tumor‐bearing mice of two low (BALB/c and C3Hf) and two high (C3H and GR) mammary cancer strains. Mammary tumors could be distinguished on the basis of MTV‐antigen expression in two groups; (1) a group of positive and (2) a group of negative tumors occurring in BALB/c mice. While the tumors of the first group in this study were all adenocarcinomas, the tumors of the second group were adenoacanthomas. MTV‐antigen production was comparatively high in tumors of the C3Hf and C3H strains, as well as in the MTV‐induced tumors of the BALB/c strain, but low in GR‐strain tumors. Sera from mice bearing MTV‐antigen producing mammary tumors (as well as from some pregnant and lactating GR mice) contained excess MTV‐antigens. Spleens of BALB/c mice bearing MTV‐antigen‐induced tumors often contained detectable amounts of MTV‐antigens, while normal and mammary tumor‐bearing C3Hf and C3H mice also occasionally showed detectable amounts of MTV‐antigens in their spleens. In contrast, spleens of GR mice were always MTV‐antigen negative by immunofluorescence absorption tests. Thymuses, livers and kidneys of the various strains tested were invariably negative.
Differences in cytochalasin B inhibition of 3‐O‐methylglucose uptake between BALB/3T3 cells and a murine sarcoma virus transformed clone
Authors: Graff Jon C. , Hanson David J. , Hatanaka Masakazu 
Published: February 2007

AbstractCytochalasin B, a mold metabolite, in concentrations of 10 μg per ml, showed a different inhibitory effect on the uptake of 3‐O‐methylglucose between a cell line transformed by the Kirsten strain of murine sarcoma virus, and its non‐transformed parent line. When the overall uptake of 3‐O‐methylglucose by the non‐transformed BALB/3T3 cells in the presence of cytochalasin B was compared to the sarcoma‐transformed cell under the same conditions, it was found that the sugar “infiltrated” into the transformed cells despite the inhibitory effect of cytochalasin B, but not into the control cells. This difference in the infiltration of 3‐O‐methylglucose in the presence of 10 μg/ml of cytochalasin B in the cells occurred despite an almost complete inhibition of the uptake of 2‐deoxyglucose in both cells caused by that same concentration of cytochalasin B. The rate of uptake of 3‐O‐methylglucose was found to be more rapid in the transformed cell line than in the parental, non‐transformed cell line. Neither the increased rate of 3‐O‐methylglucose uptake nor the “infiltration” of the sugar in the presence of cytochalasin B in the transformed cell was caused by a newly induced system for metabolizing 3‐O‐methylglucose. The 3‐O‐methylglucose uptake system was found to be a carrier‐mediated facilitated diffusion system. This system had, at least in part, a common carrier with 2‐deoxyglucose.
A study of herpes simplex type 2 antibody status in groups of patients with cervical neoplasia in Czechoslovakia
Authors: Janda Z. , Kanka J. , Vonka V. , Svoboda B. 
Published: February 2007

AbstractSera collected from patients with cervical epithelial atypia, carcinoma in situ and invasive carcinoma, as well as from control subjects, were examined for the presence of HSV‐1 and HSV‐2 antibodies. All these subjects came from one district of Prague. In agreement with results reported from other laboratories, the serological findings indicated that the prevalence of HSV type 2 antibodies was markedly higher in the groups of patients with different stages of neoplastic process in the cervix, than in control groups of comparable age and socioeconomic status. The geometric mean titres for both HSV type 1 and type 2 antibodies were higher in the invasive carcinoma patient group than in other groups of patients.
Influence of interferon on virus particle formation in different oncornavirus carrier cell lines
Authors: Billiau A. , Sobis H. , De Somer P. 
Published: February 2007

AbstractThree types of oncornavirus‐carrying mouse cell lines were studied. Replication of endogenous sarcoma or leukemia viruses in cell lines producing the infectious viruses was as sensitive to inter feron as that of exogenous vesicular stomatitis virus (VSV). Replication of non‐infectious C‐type virus in S+L− cells which carry a rescuable Moloney sarcoma virus (MSV) genome did not respond to interferon. However, this cell line was also found to be 70 times less responsive to interferon when tested by an exogenous VSV challenge. Finally, after exposure to interferon, M04 cells, which carry a rescuable MSV genome and produce non‐infectious A‐type particles, developed normal resistance to VSV. Yet, high doses of interferon could not prevent the induction of surplus A‐type particles by bromodeoxyuridine (BDU) and dimethylsulfoxide (DMSO). The results are interpreted as indicating that non‐infectious A‐type particles are synthetized by a mechanism different from that by which infectious C‐type particles are generated.
Spontaneous production of a C‐type rna virus in rat tissue culture lines
Authors: Klement V. , Nicolson M. O. , Nelson‐Rees W. , Gilden R. V. , Oroszlan S. , Ronoey R. W. , Gardner M. B. 
Published: February 2007

AbstractRecently we demonstrated the induction of a C‐type RNA virus (XCIV) in tissue culture line XC derived from Wistar random‐bred rats. In this article two other rat C‐type virus isolates (NRKAV and RPLAV) are described. They were associated with, and isolated from, NRK and RPL lines originating in Osborne‐Mendel and Lewis rat strains, respectively. The main biological characteristics shared by the three viruses were buoyant densities in sucrose gradients in the range of 1.14 to 1.15 g/ml, endogenous DNA polymerase activity, high molecular weight (60 to 70S) RNA, rat major speciesspecific (gs‐1) antigen and gs‐3 interspecies antigen. Two of the isolates (NRKAV and RPLAV) were able to rescue mouse sarcoma virus (MSV) genome from a rat MSV‐transformed non‐productive line. The NRK line was assayed for virus release at various in vitro passage levels. In lower passages (43–73) spontaneous virus release was absent or minimal but the virus could be induced by treatment of cells with 5‐bromodeoxyuridine. At higher passage levels the cells produced a large amount of virus spontaneously, but in these treatment with 5‐bromodeoxyuridine decreased virus production. The results of karyological analysis suggested that clonal selection was taking place in the NRK line during consecutive in vitro passages and simultaneously with the process of increasing spontaneous virus release.
Serum effects on cell‐mediated destruction of rous sarcomas
Authors: Hayami Masanori , Hellström Ingegerd , Hellström Karl Erik 
Published: February 2007

AbstractA microcytotoxicity test was used to study various effects of serum from tumorbearing and tumor‐free Japanese quails on cell‐mediated destruction of allogeneic sarcomas induced by the Schmidt‐Ruppin strain of the Rous sarcoma virus (SR‐RSV). Spleen cells from quails whose sarcomas had regressed (regressors) were used as the source of immune cells, since they had been previously shown to be cytotoxic to cultivated Rous sarcoma cells. Fourteen of 24 progressor sera (58.3%) gave more than 25% blocking of cell‐mediated cytotoxicity to Rous sarcoma cells when tested at dilution 1:6, and seven of these sera (29.2%) had more than 50% blocking activity. The mean blocking index of all progressor sera was 35.5% at dilution 1:6, and the mean titer of those seven sera which gave more than 50% blocking when diluted 1:6 was 25.6. Six of 18 regressor sera (33.3%) had more than 25% blocking activity at dilution 1:6 and three of them (16.7%) gave more than 50% blocking at that dilution. The mean blocking activity of the 18 regressor sera at dilution 1:6 was 16.9%, and the mean titer of the three sera which gave more than 50% blocking at that dilution was 22.8. Absorption of progressor sera with cultivated Rous sarcoma cells, but not with normal quail fibroblasts, decreased their blocking activity. Some sera from normal quails decreased the cytotoxic effect of immune spleen cells. The blocking effect of these sera was less, however, than that seen with progressor and regressor sera, and it was not removed by absorption with tumor cells. None of nine sera from bursectomized regressors was blocking at dilution 1:6, while a blocking effect was detected with three out of four sera from bursectomized progressors. The blocking effect of sera from bursectomized progressors could not be removed by absorption with Rous sarcoma cells. Its titer was lower than that of concomitantly tested progressors with intact bursa. Furthermore, sera from bursectomized progressors did not block when tested by pre‐incubation with the target cells. Four of 10 regressor sera tested could abrogate the blocking activity of progressor sera and, hence, were characterized as unblocking. On the other hand, none of five sera from bursectomized regressors had any unblocking effect. Some diluted sera from regressors, from bursectomized regressors and from progressors conferred a cytotoxic activity on normal spleen cells (“arming” effect). In addition, some sera, particularly from regressors (normal or bursectomized), potentiated the cytotoxic effect of regressor spleen cells.
The delayed rejection of tumors formed from the administration of tumor cells mixed with killed corynebacterium parvum
Authors: Likhite Vilas V. , Halpern Bernard N. 
Published: February 2007

AbstractThe effect of killed Corynebacterium parvum was studied on two different tumors; the syngeneic CAD2 mammary adenocarcinoma. transplantable only in DBA/2 mice and the Shay chloroma carried in outbred albino rats. The results show that if killed C. parvum is mixed with the tumor‐cell inoculum, the formed solid tumors undergo rapid rejection beginning 2 weeks later in both animal systems. The animals remain tumor‐free and are protected against challenges of large doses of the same tumor cells, a protection that can be eventually overwhelmed when the challenge dose is massive. Histological sections of tumors from similarly inoculated animals revealed minimal necrosis and infiltration with macrophages and lymphocytes. Groups of tumor‐inoculated animals receiving intraperitoneal injections of killed C. parvum alone or with killed tumor cells demonstrated an inhibition of tumor growth when compared to similar animals receiving saline. An enhancement of tumor growth was observed in animals receiving injections of killed tumor cells alone.
The histogenesis of tumours induced in golden hamsters by murine sarcoma virus‐harvey (MSV‐H)
Authors: Hallowes R. C. , Chesterman F. C. , West D. G. 
Published: February 2007

AbstractNewborn golden hamsters were inoculated subcutaneously with a cell‐free filtrate of cultured mouse 3T3 cells infected with murine sarcoma virus‐Harvey (MSV‐H). An electron microscopical study was made of the lesions that subsequently developed in these hamsters. Two weeks after inoculation, cysts developed eccentrically in the hila of lymph nodes draining the inoculation site. Type H (radial) virus‐like particles were seen in the endothelial cells that lined the cysts and in the serous fluid that filled the cysts. During the 3–6 weeks after inoculation, nodules appeared in lymph nodes, subcutaneous and muscle fascia. They were composed of pleomorphic cells that interlocked with each other and resembled the fixed phagocytic histiocytes of normal lymph nodes. The pleomorphic interlocking cells infiltrated and replaced lymph nodes and perinodal tissues. Some lymph nodes were replaced by abnormal mast cells. During the 12–24 weeks after inoculation tumours were found that involved the paws or limb muscles. The predominant cells in these tumours were similar to the pleomorphic interlocking cells seen in early developing lesions. Similar cells were also found in lymph nodes draining the tumours. It is concluded that tumours induced in golden hamsters by MSV‐H are mesenchymal tumours of histiocytic origin.
Tumour metastasis in mice with reduced immune reactivity. I. Studies with two MCA‐induced sarcomas in radiation and thymectomized radiation C57BL/6J chimeras
Authors: Boeryd Bernt , Suurküla Mart 
Published: February 2007

AbstractSpontaneous metastasis formation from two MCA‐induced sarcomas with different degrees of antigenicity was studied in radiation and thymectomized radiation C57BL/6J chimeras. The immune reactivity of the thymectomized chimeras was tested with one of the tumours and it disclosed no specific immune response. Tumour growth was decreased in the chimeras. Spontaneous metastasis formation was not influenced in either of the tumours by the immune suppressive treatment. The results could mean that immune factors have no influence on metastasis formation in the two systems tested, or that the immune suppressive treatment might not have influenced an interplay between presumed facilitating and inhibiting immune factors.
Wide host range of murine sarcoma virus
Authors: Rhim Johng S. , Vernon Mina L. , Duh Fuw G. , Huebner Robert J. 
Published: February 2007

AbstractCultures of canine, rabbit, porcine, avian, feline, bovine, simian and human origin were tested for their susceptibility to the Kirsten murine sarcoma virus (Ki‐MSV). Data indicated that Ki‐MSV replicates and transforms the cultures of canine embryo, rabbit kidney, porcine kidney, feline embryo, bovine embryo and human tumor cells. These morphologically altered cells contained infectious virus and group‐specific (gs) complement‐fixing (CF) antigen characteristic of viruses of the murine sarcoma‐leukemia complex. The infected cultures produced type‐C virus particles. RNA‐dependent DNA polymerase activity was also demonstrable in the altered cells. The present results indicate that members of the murine sarcoma‐leukemia virus complex, particularly Ki‐MSV, exhibit a wider host range than was hitherto believed.
Viral‐related DNA sequences before and after transformation by RNA tumor viruses
Authors: Goodman N. C. , Ruprecht R. M. , Sweet R. W. , Massey R. , Deinhardt F. , Spiegelman S. 
Published: February 2007

AbstractMarmoset monkey fibroblasts transformed by non‐indigenous RNA tumor viruses (RSV or FeSV) acquire viral DNA sequences not present in normal cells. The newly gained sequences are always related to those of the transforming virus, a result in agreement with the proviral hypothesis. In contrast, the nucleic acid of the indigenous simian RNA tumor virus, SSV‐1, exhibits partial homology with the DNA of normal marmoset fibroblasts as well as with SSV‐1‐transformed cells. Since a similar situation has been observed with avian and lower mammalian systems, it would appear that homology with normal cellular DNA can be used to provide a tool for determining the species of origin of newly isolated RNA tumor viruses.
Statistical methods for the identification and use of prognostic factors
Authors: Armitage P. , Gehan Edmund A. 
Published: February 2007

AbstractThis is an expository paper which reviews the rationale for determining prognostic factors and the statistical methods for finding and allowing for such factors in the design and analysis of clinical studies. The delineation of prognostic factors in clinical studies is useful: in possibly providing insight into the mechanism of disease; in the determination of stratifications of patients for planning clinical trials; in facilitating the comparison between the outcomes of disease in different groups of patients; in assisting in the allocation of treatment to an individual patient and in permitting remedial action. A response variable is a measure of the future health or illness of the patient and its value is usually dependent on one or more prognostic variables. Statistical methodology for determining prognostic factors is reviewed for the case in which response is dichotomous, continuous or a measure of time (with the possibility of censored observations) and when the predictor variables are discrete or continuous (or a combination of both types). Methods of allowing for known prognostic variables in the analysis of a study are reviewed. These include: grouping of patients according to prognostic variables and comparing treatments separately within each group; covariance analysis and maximum likelihood. Knowledge of prognostic factors is useful in defining a control group which is to be compared with a treated group in non‐randomized studies. Three examples of studies designed to elucidate prognostic factors are described, one each in breast cancer, cancer of the prostate and Hodgkin's disease.
Further studies on the ability of regressor sera to block cell‐mediated destruction of rous sarcomas
Authors: Hayami Masanori , Hellström Ingegerd , Hellström Karl Erik , Lannin Donald R. 
Published: February 2007

AbstractPrevious studies have shown that most sera from Japanese quails with growing sarcomas induced by the Schmidt‐Ruppin strain of the Rous virus (SR‐RSV) can block cell‐mediated destruction of Rous sarcoma cells in vitro, and that sera from some quails whose Rous sarcomas have spontaneously regressed (regressors) also have that ability. Six regressor sera, previously shown to be blocking when added to the mixture of target and effector (=regressor spleen) cells in vitro, were tested for blocking effect at either the target or the effector cell level. Three sera could block only when incubated with the target cells, while three other sera blocked at both the target cell and the effector cell level. Two of three regressor sera which had previously been shown to be unblocking (abrogating the blocking activity of progressor sera when mixed with these in vitro) increased cell‐mediated cytotoxicity at a low dilution (potentiation) but had a slight blocking activity at dilution 1:128–1:512, which disappeared upon further dilution. The blocking effect seen at these dilutions appeared to occur at the target cell level and was not detectable after incubation of the effector cells with serum. After incubation of the target cells for 24 h with one of these two regressor sera diluted 1:256, a blocking activity detectable at the effector cell level appeared in the culture medium. The blocking activity of serum from bursectomized progressors (previously reported) increased, after regressor serum diluted 1:16 had been added to it; at that dilution, the regressor serum had no blocking activity by itself. More concentrated regressor serum, on the other hand, was unblocking, i.e. it decreased the blocking activity of serum from bursectomized progressors. The data are compatible with the hypothesis that the blocking factors operating in this system are complexes between antigens released from the tumor and antibodies formed by the host (and, occasionally, free antigen).
Early chromosome changes in diploid Chinese hamster cells after infection with simian virus 40
Authors: Lehman John M. 
Published: February 2007

AbstractPrimary and secondary Chinese hamster (ChH) embryo cells infected with SV40 exhibited chromosomal changes within one cell generation (24 h). The initial change seen is an increase in the number of polyploid metaphases (>10%). The majority of the polyploid cells are tetraploid (8×), however, higher ploidy values were also observed (16 ×, 32 × and 64 ×). In approximately 20–30% of the polyploid metaphases there were chromosome changes such as breaks, abnormal chromosomes and loss and addition of chromosomes. The remaining polyploids were normal in regard to chromosome number and chromosome morphology. A primary mouse embryo cell system also responded to SV40 infection with an increase in the number of polyploid cells within 48 h.