bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rous sarcoma virus production in mixed cultures of mammalian rous sarcoma cells and chick embryo cells
Authors: Yamaguchi N. , Takeuchi M. , Yamamoto T. 
Published: February 2007

AbstractThe induction of Rous sarcoma virus (RSV) production was analyzed in mixed cultures of mouse or hamster Rous sarcoma cells and chick embryo cells treated with ultraviolet inactivated hemagglutinating virus of Japan (UV‐HVJ). The pre‐treatment of UV‐HVJ with a certain concentration of anti‐HVJ serum increased the yield of infectious RSV in mixed cultures enabling a quantitative analysis of this phenomenon to be made. RSV‐inducing ability of a mixture of HVJ and anti‐HVJ serum was affected by the concentration of anti‐HVJ serum and showed changes in parallel with the cell fusion activity of the mixture. The effect of UV‐HVJ on RSV induction was not achieved by incubation of the cell mixture at 0° C as it was after shaking at 37° C. These findings suggest that the production of infectious RSV in mixed cultures may be initiated in heterokaryons of mammalian Rous sarcoma cells and chick embryo cells. The number of infective centers in mixed cultures was, however, as small as 1% of that of heterokaryons. It is possible that only a small fraction of the heterokaryon population is productive of infectious RSV.
Murine sarcoma virus: Titration patterns and interference by a murine leukemia virus
Authors: Somers K. D. , Kirsten W. H. 
Published: February 2007

AbstractA murine sarcoma virus (MSV‐K) was assayed by conversion of 3T3 mouse cells into foci of morphologically altered cells. Murine erythroblastosis virus (MEV), a member of the murine leukemia virus group, induced resistance in 3T3 cultures specific to super‐infection with focus‐forming MSV‐K. Interference by MEV was first detected at 14 days and reached maximal levels 21 days post infection. MSV‐K preparations from transformed 3T3 cells contained competent virions, as judged by “one‐hit” titration patterns. Since excess “helper” MEV in MSV‐K stocks could effectively convert titration patterns to “one‐hit” kinetics, the ratio of MEV to MSV‐K was determined by interference experiments. The ratio of MEV to MSV was approximately 10:1. Thus it appears that a single particle is capable of producing a focus of altered cells in the absence of simultaneous infection with a separate particle of MEV.
Thoracic duct lymph cytology in Hodgkin's disease
Authors: Engeset A. , Höeg K. , Höst H. , Liverud K. , Nesheim A. 
Published: February 2007

AbstractSternberg‐Reed cells were demonstrated in seven out of 10 patients with Hodgkin's disease by catheterization of the thoracic duct.In two patients with normal para‐aortic nodes on lymphangiography no Sternberg‐Reed cells were seen in the thoracic duct lymph.In one patient the diagnosis of abdominal Hodgkin's disease was established by thoracic duct lymph examination.
Metabolism and binding to cellular macromolecules of a series of hydrocarbons by mouse embryo cells in culture
Authors: Duncan Margaret , Brookes P. , Dipple A. 
Published: February 2007

AbstractA series of eight tritium‐labelled polycyclic hydrocarbons were incubated in the presence of monolayer cultures of primary mouse embryo cells, and the time‐course of their metabolism to water‐soluble derivatives was studied. All the hydrocarbons, both carcinogenic and non‐carcinogenic, were metabolized at approximately the same rate when a low concentration of the order of 0.05 μM was used. The binding of the various hydrocarbons to cellular DNA, RNA and protein was determined and a “binding index” calculated, i.e., the extent of reaction of the hydrocarbon with the particular macromolecule resulting from the metabolism of 1 mμmole of hydrocarbon per ml of medium to which the cells were exposed. While no very significant difference between the various hydrocarbons was found for the protein binding index, the DNA and RNA binding indices divided the compounds into two groups. One group with a high binding index consisted of potent carcinogens while the other group had much lower (one tenth) values for the binding index. With the exception of dibenz[a, h]anthracene, this latter group consisted of non‐carcinogens.
Studies on murine sarcoma virus; A morphological comparison of tumorigenesis by the harvey and moloney strains in mice, and the establishment of tumor cell lines
Authors: Berman L. D. , Allison A. C. 
Published: February 2007

AbstractAnatomic lesions produced by the Moloney and Harvey strains of Murine Sarcoma Virus (MSV‐M and MSV‐H) in mice have been compared. Erythroblastic splenomegaly is a distinctive feature of disease produced by MSV‐H. Solid tumors induced by both viruses were quite similar in morphology, although some consistent differences were noted. The tumors appear to arise by massive recruitment of primitive mesenchymal cells rather than by clonal proliferation. The morphological features of these lesions would suggest that, although MSV‐M and MSV‐H are similar entities, they are not quite identical.Four transplant lines have been established from the mouse tumors; three MSV‐H and one MSV‐M. The MSV‐M line (CBA strain) was initiated with difficulty and did not release sarcoma virus. The MSV‐H lines (two CBA and one BALB/c) were easier to initiate and virus release was demonstrated both in vivo and in vitro. In addition to tumor growth at the site of implantation, the BALB/c line also produced splenic erythroblastosis. The MSV‐M and one of the MSV‐H CBA lines underwent a distinctive alteration during the course of in vivo passage in which the original spindle‐cell lesion evolved into an undifferentiated small‐cell tumor.
Titrage de la tumorigénicité des cellules transformées sur la membrane chorio‐allantoïdienne de l'oeuf de poule
Authors: Vigier P. 
Published: February 2007

AbstractLes suspensions monodispersées de cellules transjormées de cultures in vitro produisent des tumeurs par inoculation sur la membrane chorio‐allantoïlienne d'aufs de poule emhryonnés. La tumorigénicité (transplantahilité sur la MCA) pelit être titrée énumérativement en comptant Irs tumeurs produites en 7 jours sur la MCA d'æufs de 11 jours. La distribution des nombres de turneurs est logarithmico‐normale, et les nombres moyens sont proportionriels uu rtombre de cellules inoculkes lorsqu'ils sont faibles (moins de 10). L'erreur décroit avec I'augmentation du nomhre d'æufs, et des intervalles de confance 95% inférieurs à 0.48 log10, ant été obtrtius dans les séries de plus de 10 æufs. Les titrages sont reproductibles, et le nombre moyen de cellules requis pour produire une tumeur (DT) est gétiéralement resté constant dans les lignées clonales établies, re qui suggère que c'est un caractère génétique stable des ce1lules. Cependant, dans certaines lignées, la DT a dimitiué jrrsqu'à un palier inférieur, satis doute par sélection de variants à tumorigénicité augmetitée. La DT des cellules transfimiées et établies de rongeurs Péait généralement inférieure á celle des cellriles transformées mais à vie limitée de primates, et une ligriée de cellules humaines morphologiqirement transformées n'a, mêmes, pas donné de tumeurs. Des tumeurs ont aussi été obtenues avec les cellules de hamster non transformées mais étahlies BHK21/13, mais pas avec les cellules diploïdes non transformérs et non établies de primates ou de poule. La DT des cellules BHK21 transformées et non trawsformées est plus élevée que la DT50 des mêmes cellules chez le Hamster syrien, mais elk lui est proportionnelle.
The pattern of protein synthesis in SV40‐infected CV‐1 cells
Authors: Fischer Hans , Munk Klaus 
Published: February 2007

AbstractThe time sequence of induced proteins after SV40 infection has been studied by polyacrylamide gel electrophoresis. The alteration of the protein pattern has been followed in stained gels of protein preparations and in gels of protein preparations after pulse labelling cells with 14C amino acids. The proteins of cell extracts were prepared either by precipitation at 60% ammonium sulfate saturation or by disintegration with 8 M urea. The precipitated protein pattern was altered after infection in correlation with the changes in pattern of incorporated isotopes. New bands and increases in bands present in control cultures were observed. After urea treatment the particulate protein pattern revealed three new peaks at 15 h after infection. The most significant alterations, compared to the uninfected CV‐1 cells, occurred at 32 h post infection. Three complexes, peaks 3–8, 10–13, and 14–17, and peak 23 increased at this time. Protein synthetic activity in these areas was confirmed by the electrophoresis of pulse‐labelled proteins.
Immune response to urinary bladder tumours in man
Authors: Bubenïk J. , Perlmann P. , Helmstein K. , Moberger G. 
Published: February 2007

AbstractA microassay in disposable tissue culture plates was used to demonstrate a cell‐mediated immune response against human urinary bladder carcinoma. Leukocytes isolated from peripheral blood of patients with urinary bladder tumours were allowed to react in vitro with cells of bladder tumours, or with a control tumour or normal cells. Both autochthonous and allogeneic leukocytes from patients with bladder tumours strongly reduced the number of plated bladder tumour cells as compared to control leukocytes, but did not affect control tumour or normal cells. No significant cytotoxic effects were produced by control leukocyte suspensions from a patient with prostatic carcinoma, from patients with non‐neoplastic diseases or from normal healthy individuals.The results indicate that human urinary bladder tumours possess tumour‐specific antigens which cross‐react with each other.
Biochemical studies on growth‐inhibitory bisdioxopiperazines. I. Effect on dna, rna and protein synthesis in mouse‐embryo fibroblasts
Authors: Creighton A. M. , Birnie G. D. 
Published: February 2007

AbstractA number of bisdioxopiperazines have recently been shown to possess marked growth‐inhibitory activity against a range of experimental tumours in mice and rats. These compounds were originally designed as potential intracellularly activated chelating agents. In the present investigation, two of these compounds (±)‐1,2‐bis (3,5‐dioxopiperazin‐1‐yl) propane (ICRF 159) and meso ‐2,3‐bis (3,5‐dioxopiperazin‐1‐yl) butane (ICRF 193) have been shown to be potent inhibitors of DNA synthesis in growing mouse‐embryo fibroblasts while having relatively little effect on RNA and protein synthesis. In this respect, their behaviour strongly resembles that of radiomimetic drugs and ionizing radiation. X‐rays and both ICRF 159 and ICRF 193 exhibit a very similar pattern for the time‐course of the inhibition of 3H‐thymidine uptake into DNA. They all show a recovery taking place about 4 h after the initial treatment (presumably due to repair and/or stimulation of unscheduled DNA synthesis) followed later by a more substantial and permanent inhibition. In view of the structure of these compounds, it is possible that they may be exerting a radiomimetic effect by acting as mono‐ or bi‐functional acylating agents.
Structural proteins of murine erythroblastosis virus
Authors: McDugald L. V. , Panem S. , Kirsten W. H. 
Published: February 2007

Abstract3H‐amino‐acid labelled murine erythroblastosis virus (MEV) was harvested from the EMS cell line and purified by centrifugation in sucrose or potassium‐citrate gradients. 3H‐amino‐acid labelled nucleoids were isolated from MEV by the tween‐ether method. Proteins were solubilized from whole MEV and MEV‐nucleoids. Electrophoresis in polyacrylamide gels of pH 7.2 in 0.5 M urea for 17 h yielded three major peaks of radioactivity from whole MEV preparations. These proteins were referred to as MEV‐1, MEV‐2 and MEV‐3. In addition, two minor protein peaks, MEV‐a and MEV‐b, were recovered from whole MEV. Only two major peaks, MEV‐1 and MEV‐2, and one minor component, MEV‐a, were found in electropherograms of MEV‐nucleoids. The results were reproducible with MEV progeny harvested from later subcultures of EMS cells. The results suggested that MEV‐3 and MEV‐b were structural proteins of either the virion coat or the internal virion structure.
A new virus of minimal pathogenicity associated with friend virus. I. Isolation by end‐point dilution
Authors: Rowson K. E. K. , Parr Iris B. 
Published: February 2007

AbstractIn an attempt to purify a strain of Friend virus (FV) by passage in mice at end‐point dilution, we injected groups of BALB/c mice with ten‐fold dilutions of the virus. After 3 weeks, plasma was collected from each mouse and the spleen weighed. Mice given virus diluted 10−7 and untreated controls had spleens weighing between 100 and 120 mg. Of the six mice given virus diluted 10−1, two had spleens weighing over 200 mg; plasma samples from both of these and from two mice of the same group, which had normal sized spleens, were tested in mice. After 3 weeks, only the recipients of plasma from mice with splenomegaly had enlarged spleens (200–350 mg). The virus obtained by end‐point dilution is referred to in this paper as the Rowson‐Parr virus (RPV). It has been passaged by plasma seven times at 3‐weekly intervals and regularly produces splenomegaly of a minor degree which does not progress. The virus is present in the plasma of infected animals for at least 122 days and the spleen does not return to normal but the infection is not lethal. Mice infected with RPV develop gross splenomegaly following a subsequent injection of FV but the disease progresses more slowly than in mice infected with FV alone. Neutralizing FV antibodies could not be demonstrated in the plasma of RPV infected mice. On filtration through gradocol membranes RPV appeared to be the same size as FV. It was chloroform sensitive, resistant to terramycin and did not affect the plasma lactate dehydrogenase level of infected mice.
A new virus of minimal pathogenicity associated with friend virus. II. Histological changes and immunodepressive effect
Authors: Carter R. L. , Chesterman F. C. , Rowson K. E. K. , Salaman M. H. , Wedderburn N. 
Published: February 2007

AbstractHistological reactions induced in BALB/c mice by a new virus with minimal pathogenic action — the Rowson‐Parr virus (RPV) — are described. The changes were virtually confined to the spleen and consisted of moderate splenomegaly (200–350 mg) associated with hyperplasia of the red pulp, particularly in the perifollicular zones, and enlargement and activation of the germinal centres. No proliferation of plasma cells was noted at any time. These changes persisted (with minor fluctuations) for 6 months or more, but are described in detail for only the first 3 weeks in the present account. A severe depression of the immune response to sheep erythrocytes was observed between the 2nd and 6th days after infection; a more moderate immunodepression was detected up to 6 months or more after infection. The significance of these findings is discussed.
Diethylnitrosamine oncogenesis in RF mice as influenced by variations in cumulative dose
Authors: Clapp N. K. , Craig A. W. , Toya R. E. 
Published: February 2007

AbstractDiethylnitrosamine (DEN) was given to male RF mice in the drinking water at levels of 2–11.5 mg/kg body weight daily for varying periods; cumulative doses ranged from 57 to 943 mg/kg body weight. In all treated groups, incidences of lung adenomas, hepatomas, and forestomach squamous cell carcinomas exceeded those in controls; maximum incidences reached 84%, 98%, and 100%, respectively, as compared with control values of 41%, 5%, and 0%. At lower doses, incidence of liver tumors increased linearly with dose, reaching 80–90% at DEN doses of 300 mg/kg and above, whereas the lowest dose of DEN induced a maximum incidence of lung tumors. Only at the lowest dose did DEN fail to induce a maximum incidence of stomach tumors. The mean survival time, mean age at death with all types of tumors, and minimum induction times decreased with increasing dose. DEN did not exert a leukemogenic effect at the doses used, and an inhibitory effect is even suggested: only 1/371 (0.3%) DEN‐treated mice developed myeloid leukemia and 4/371 (1%) thymic lymphoma, compared with control values of 7/162 (4%) and 6/162 (3.7%), respectively. At the lowest dose used, the lung appears most sensitive (maximum tumor induction), the stomach intermediate in sensitivity, and the liver least sensitive to DEN‐oncogenesis.
Cancer of the oesophagus: Further evidence of the relation to drinking habits in France
Authors: Tuyns A. J. 
Published: February 2007

AbstractPrevious studies have shown a correlation between mortality from cancer of the oesophagus and that from “alcoholism” and cirrhosis. It is now shown that the correlation is greater with the former than with the latter; as “alcoholism” deaths occur rather in spirit drinkers, this correlation may indicate that it is for this category of drinkers that the risk of oesophageal cancer is greatest. The pattern of the geographic relation between “alcoholism” and oesophageal cancer is consistent with the hypothesis that spirit drinking is a necessary but not a sufficient condition for the development of oesophageal cancer.
Prolactin and mammary gland carcinogenesis. The problem of human prolactin
Authors: Boot L. M. 
Published: February 2007

AbstractThe ultimate objective of experimental cancer research must be to apply the findings obtained to the prevention or treatment of the disease in humans. In this review it is shown that prolactin is suspected of being one of the hormones mainly responsible for the development of mammary carcinoma in mice. Investigations into the question of whether this might also be true in man are hampered by the fact that the existence of prolactin in this species is still a matter of debate. Because of the intrinsic prolactin‐like activity of purified human growth hormone, the need for the presence of prolactin as a separate hormone might be questioned. It is shown, however, on the basis of a number of biological arguments and clinical observations, that it is extremely unlikely that all prolactin‐like effects in man are due to one of the manifold activities of growth hormone alone; consequently the urgent need to analyse the role of prolactin as a separate hormone in man becomes evident, especially in the field of breast cancer. Tentatively, ways are indicated by which this objective might be reached.
Detection of specific surface antigens by colony inhibition in cells transformed by papovavirus SV40
Authors: Tevethia Satvir S. , Crouch Norman A. , Melnick Joseph L. , Rapp Fred 
Published: February 2007

AbstractSpecific antigens at the surface of SV40‐transformed hamster cells were demonstrated by the in vitro colony inhibition and immunofluorescence tests. Antisera were prepared by inoculating hamsters either with purified SV40 or with human or marmoset SV40‐transformed cells. The inhibition of colony formation by the transformed cells ranged from 46 to 100% in the presence of specific antibody and complement. Nontransformed hamster cells were not inhibited by the immune sera.Of the 22 sera tested, 12 were positive in the colony inhibition test and 14 were positive in the immunofluorescence test. Eleven of the 22 sera tested were positive in both tests. This positive correlation between the colony inhibition and immunofluorescence tests suggests that the two tests are detecting the same or similar antigens.
In vitro cultivation of the mouse mammary tumor virus: Correlation of infectivity and morphology with radioisotope studies
Authors: Cardiff Robert D. , Blair Phyllis B. 
Published: February 2007

AbstractOrgan and cell cultures of BALB/cfC3H mammary tumor tissue release infectious MTV into the medium. Not only were bioassays of culture fluid for MTV positive, but also radioisotope‐labelled MTV‐RNA and MTV B‐particle antigenicity could be detected in the culture fluid. In addition, type B virus particles were found budding from the cell membranes. Bioassays of control MTV‐free BALB/c tumor cultures were negative, as were radio‐chemical, immunological and morphological studies. Thus, infectivity could be correlated to the presence of labelled B particles in the cultures.
Morphologic and cytogenetic studies in vitro of surface‐adherent lymphoreticular cells derived from burkitt lymphoma tissue
Authors: Rabson A. S. , Chu E. W. , Berezesky I. K. , Legallais F. Y. , Grimley P. M. 
Published: February 2007

AbstractA line of lymphoreticular cells (AL‐1‐G) that can adhere to glass surfaces has been derived from suspension cultures of Burkitt lymphoma cells (AL‐1). By light microscopy, the predominant cell type in the AL‐1‐G cultures has features of a neoplastic histiocyte and ultrastructurally these cells have more elaborate development of cytoplasmic organelles, such as elements of the Golgi complex and mitochondria, than the predominant cell types in the suspension cultures of AL‐1. Cytogenetically, the percentage of polyploid cells in the AL‐1‐G cultures increased progressively from 39% in 1967 to 100% in 1968 and 1969, while the percentage of polyploid cells in the suspension cultures remained between 12 and 24% during the same period. No herpesvirus or any other type of viral particle was found in the AL‐1‐G cultures on repeated electron microscopic examination.
Altered glucose transport kinetics in murine sarcoma virus‐transformed BALB/3T3 clones
Authors: Hatanaka Masakazu , Todaro George J. , Gilden Raymond V. 
Published: February 2007

AbstractThe kinetics of glucose transport were determined for a number of spontaneous and virus‐transformed cell lines derived from a single clone of BALB/3T3 cells. SV40‐transformed and mouse leukemia virus‐infected cells were characterized by a Km very similar to that of the parental cell line. In contrast, murine sarcoma virus‐transformed cells had a much lower Km. These findings are in agreement with previous results obtained with mass cultures of NIH Swiss mouse embryo cells. One X‐irradiation and two spontaneous transformants also showed low Km values and no virions or virion antigens. These latter cell lines should provide an opportunity for a crucial test of the relationship between glucose transport kinetics and a functional sarcoma virus genome.
Effect of withaferin a on ehrlich ascites tumor cells — cytological observations
Authors: Shohat Batia , Gitter Simon , Lave David 
Published: February 2007

AbstractWithaferin A, a steroidal lactone with carcinostatic properties, isolated from the leaves of Withania somnifera Dun., produced a mitotic arrest in the metaphase of dividing Ehrlich ascites carcinoma cells. In addition this compound also induced vacuolization of the cytoplasm. A single dose of withaferin A, administered 24 hours after Ehrlich ascites implantation, caused growth reduction followed by disappearance of the tumor in 80% of the mice. These mice were found to be resistant to rechallenge with Ehrlich ascites tumor cells. The inhibition of Ehrlich ascites tumor growth is thought to represent a combined effect of withaferin A action and immune reactions.
Comparative studies on distribution of DMBA‐3H and 7‐hydroxy‐DMBA‐3H and their carcinogenic activity
Authors: Flesher James W. , Syndor Katherine L. 
Published: February 2007

AbstractRadioactivity in selected tissues was measured 24 and 72 h after a single feeding of DMBA‐3H or 7‐hydroxy‐DMBA‐3H to female Sprague‐Dawley strain rats, aged 50 days. The concentration of radioactivity per gram of mammary tissue 24 h after a single 5‐, 10‐ or 20‐mg dose of DMBA‐3H was equivalent to 3.2, 6.4 and 15.5 μ respectively. The concentration of radioactivity after 20 mg 7‐hydroxy‐DMBA‐3H was equivalent to 4.8 μ of unchanged hydrocarbon. After a single feeding of 5, 10 or 20 mg of DMBA the incidence of breast cancer was 27, 72, and 100% respectively; after 20 mg 7‐hydroxy‐DMBA, it was 45%. These observations indicate that the level of hydrocarbon in mammary fat is one of the critical determinants for induction of breast cancer. In addition to breast cancer, the 7‐hydroxymethyl compound induced nephroblastoma, lung cancer, and leukemia. These observations support the hypothesis that 7‐hydroxy‐DMBA, a metabolite of DMBA, is more closely related to the proximate carcinogen than the parent compound.