bluuebunny/crossref_metadata_2025_split huggingface dataset:
Active specific immunotherapy of minimal residual tumor: Excision plus neuraminidase‐treated tumor cells
Authors: Rios Angelyn , Simmons Richard L. 
Published: February 2007

AbstractTumor growth can be severely inhibited and total regression occasionally induced when mice bearing firmly established transplantable syngeneic tumors are challenged with living tumor cells which have been treated in vitro with Vibrio cholerae neuraminidase (VCN) plus mitomycin C. Tumors greater than 1 cm in diameter will not regress. The present experiments were designed to determine if immunotherapy could be effective if the tumor mass were surgically reduced. Three tumors previously shown to be susceptible to active specific immunotherapy with VCN‐treated tumor cells were utilized. Two time periods were selected, that in which VCN‐treated tumor cells will normally inhibit growth (12–15 days post inoculation) and that time period after which VCN‐treated tumor cells alone are insufficient to inhibit growth (25 days post inoculation). Three types of tumor excision were investigated; minimal reduction in tumor mass by wedge excision, subtotal reduction of tumor mass by tumor enucleation, and attempts at total excision with narrow margins. The combination of subtotal or total excision plus challenge with VCN‐treated tumor cells was significantly more effective than either excision or immunotherapy alone. The best results were obtained with the MC‐43 methylcholanthrene‐induced fibrosarcoma and a transplantable mammary adenocarcinoma (M‐2). No synergistic or additive effect of specific active immunotherapy and surgical therapy was noted in the B16 melanoma, which tends to metastasize early after implantation and grows as an indistinct infiltrative local tumor mass rather than a well‐pronounced local growth. Results strongly suggest that the reduction in tumor mass by surgical means might allow active specific immunotherapy to become an effective anti‐tumor adjunct.
Immunogenetic aspects of nasopharyngeal carcinoma: I. Differences in HL‐A antigen profiles between patients and control groups
Authors: Simons M. J. , Wee G. B. , Day N. E. , Morris P. J. , Shanmugaratnam K. , De‐Thé G. B. 
Published: February 2007

AbstractThis paper reports the results of two studies which compared the HL‐A profile of predominantly Chinese patients with nasopharyngeal carcinoma to that of suitably chosen controls. The first study demonstrated a significant increase in the proportion of NPC patients in whom less than two second locus antigens were detectable. The second confirmatory study also demonstrated the same phenomenon at a high level of statistical significance, and furthermore showed a significant elevation among the NPC patients of the frequency of HL‐A2. Both the elevation of the HL‐A2 frequency and the deficit of detectable second locus antigens remained significant after application of the most conservative correction factor for the number of antigens investigated. Various sources of bias have been considered and appear not to have appreciably influenced the results. The results are discussed in terms of the postulated genetic basis of the elevated risk for NPC among the Chinese.
Interactions between the peripheries of ehrlich ascites tumor cells as indicated by the binding of colloidal iron hydroxide particles
Authors: Weiss L. , Subjeck J. R. 
Published: February 2007

AbstractAn attempt was made to correlate contact between Ehrlich ascites cells growing in stationary culture, with the distribution of colloidal iron hydroxide particles adsorbed to their surfaces after fixation. It was observed that significantly fewer particles were adsorbed to regions of surfaces at which microvilli from other cells were “aimed”, than in adjacent regions. Although the precise relationship of this alignment to cell contact is problematical, the fact that alignment occurs at all is indicative of interactions taking place between regions of cell surfaces, and the modification of these surfaces as a result of the interactions.
Properties of flat variants of murine sarcoma virus transformed non‐producer cells isolated after high‐temperature passage
Authors: Gazdar Adi F. , Stull Harold B. , Chopra Harish C. , Ikawa Yoji 
Published: February 2007

AbstractHigh‐temperature passage (40.5°C) increased the incidence of flat variants obtained from Kirsten sarcoma virus transformed BALB/3T3 non‐producer cells from less than 0.1% to 4%. The flat variants had growth properties similar to those of the BALB/3T3 line. The variant lines did not release detectable type C virus, but some contained intracisternal type‐A particles. Super‐infection of the variants with murine leukemia virus (MuLV) resulted in retransformation and release of sarcoma virus. Some of the variant lines may be suitable indicator cells for the assay of MuLV. Modal chromosome numbers of the variant lines were considerably higher than those of their progenitor cell line.
Differences in the surface mobility between normal and SV40‐, polyoma‐ and adenovirus‐transformed hamster cells
Authors: Huet Ch. , Bernhard W. 
Published: February 2007

AbstractLiving cultures of normal hamster cells, and of hamster cells transformed by SV40, polyoma, Adenovirus 12 and Simian Adenovirus 7, were labelled in situ by 63Ni‐Concanavalin A, as well as by Con A and WGA revealed cytochemically by peroxidase, and by negative colloidal iron. They were then incubated at 37°C in PBS for different periods of time, varying from 8 min to 4 h prior to fixation and processing for electron microscopy. Con A labelling allowed us to show differences in the surface movements between normal and virus‐transformed cell cultures: the transformed cell lines had a much greater membrane mobility since most of the Con A/peroxidase‐labelled material disappeared from the cell surface within 15 to 30 min, whereas in normal cells it took 30 to 60 min to obtain the same patterns. Measurements of radioactive Con A showed that most of the lectin penetrated into the cell, and that shedding of labelled cell coat material into the medium was minimal. With the negative colloidal iron, the available amino groups were labelled and the same difference in the surface movements was again observed. However, we were unable to show any difference between normal and transformed cells with the WGA‐peroxidase complex. Rapid penetration occurred in both cell types, but in both cases label also remained present at the surface.
Kinetics of uptake of 2‐deoxy‐d‐glucose and 2‐aminoisobutyric acid in chemically transformed cells
Authors: Kuroki Toshio , Yamakawa Shigeyo 
Published: February 2007

AbstractKinetics of 2‐deoxy‐D‐glucose and 2‐aminoisobutyric acid uptake in chemically transformed hamster embryo cells and BALB 3T3 cells were investigated. Maximum velocity of the glucose uptake in chemically transformed cells increased 1.5 to 2.8‐fold over controls in Vmax without a detectable change in apparent Km. In uptake of the amino acid there was a slight change in Vmax and unchanged Km with chemically transformed cells, as compared to untransformed cells. Hexokinase activity showed a slight change after chemical transformation.
Induction of mammary fibroadenomas in rats by adenovirus type 9
Authors: Ankerst J. , Jonsson N. , Kjellén L. , Norrby E. , Sjögren H. O. 
Published: February 2007

AbstractAfter inoculation of adenovirus type 9 into newborn Wistar/Furth rats, seven out of seven females developed one or several mammary fibroadenomas within 14–25 weeks after virus inoculation. No tumours were observed in male rats inoculated with the same virus or in untreated controls. Neonatal inoculations of adenovirus type 5, produced on the same HeLa cells, gave negative results in both sexes. The results indicate that benign mammary tumours can be induced in rats by a virus and that mammary fibroadenomas are induced by adenovirus type 9, previously known to be capable of transforming cells in vitro but not of inducing tumours in vivo.
Aetiological factors in oesophageal cancer in Singapore Chinese
Authors: de Jong U. W. , Breslow N. , Goh Hong J. Ewe , Sridharan M. , Shanmugaratnam K. 
Published: February 2007

AbstractAnalysis of a hospital‐based case‐control study of oesophageal cancer among Singapore Chinese (composed of Cantonese, Hokkien, Teochew and other dialect groups) revealed the following statistically significant risk factors for both sexes: (I) belonging to either Hokkien or Teochew dialect groups; (2) the consumption of beverages at temperatures stated subjectively to be “burning hot” prior to illness; and (3) the smoking of Chinese cigarettes. Additional risk factors for males were birth in China and the consumption of Samsu (Chinese wine). Consumption of bread, potatoes and bananas was reported at significantly lower levels in male oesophagus cancer patients than in controls. Oesophageal cancer was less common in males who had attended school for more than 8 years. Multivariate analysis (examination of the joint influence of selected variables) confirmed the strong effects of dialect group and beverage temperature for both sexes. For females the smoking of Chinese cigarettes remained a risk factor, for males the consumption of Samsu. The smoking of westerntype cigarettes and the consumption of strong liquors were not significantly related for either sex. These findings suggest that oesophageal cancer is more likely to occur among “traditional” Chinese who maintain dietary patterns which include Samsu and the drinking of beverages at hot temperatures, but avoid the bland foodstuffs (bread, potatoes and bananas) not native to their culture. The greater risk in Teochew and Hokkien may be due in part to the consumption of a greater number of beverages at “burning hot” temperatures compared with Cantonese and other dialect groups. However, these differences are based on subjective impressions which need to be verified by actual measurements of the temperature of drinks consumed by members of these population groups.
Studies on the mechanisms of invasion in cancer. IV. A factor associated with release of neutral protease of tumor cell
Authors: Koono Masashi , Katsuya Hiroaki , Hayashi Hideo 
Published: February 2007

AbstractA substance capable of releasing a certain neutral protease from rat ascites hepatoma cells was extracted from tumor tissues and partially purified. The substance, which was assumed to be a thermostable peptide, was characterized by prompt action and noncytotoxicity. Intradermal injection of the released neutral protease induced extravascular migration of circulating tumor cells and formation of metastases. No protease could be released from normal hepatic cells. These observations suggested that the released neutral protease might be involved in malignant invasion through production of postulated cancer‐cell‐chemotactic factor. Such a substance was, however, difficult to demonstrate in normal skin. Different factors associated with the release of another neutral protease and an alkaline protease were also found. However, these proteases did not provoke invasion of tumor cells after intradermal injection.
Alterations in macromolecular synthesis and cellular growth in mouse embryo fibroblasts infected with friend leukemia virus
Authors: Gabelman Norman , Scher William , Friend Charlotte 
Published: February 2007

AbstractThe rate of DNA synthesis in secondary mouse embryo fibroblast (MEF‐2) cultures was increased following infection with Friend leukemai virus (FLV) as compared to control cultures which were untreated or exposed to heat‐denatured virus. A peak was reached between 24 and 48 h after infection. Radioautographic studies revealed that the infected cultures had a higher percentage of cells which incorporated tritiated thymidine into their nuclei as compared to controls. This increase was apparently independent of the ability of the cells to divide, since it was also observed in infected stationary cultures. The rates of cellular RNA and protein synthesis did not appear to be affected by FLV infection. The time required for the cell population to double was one‐third shorter in FLV‐infected cultures as compared to controls. The shortening of the generation time was found to be due to a decrease in the time required for the cells to traverse the G1 and S phases of the cell cycle. In addition, after 72 h of growth, the infected cultures reached greater population densities than did either of the controls.
Characteristics of murine C‐type viruses. III. Antigenic conversion and focus induction
Authors: Grundner Gertrud , Fenyö Eva Maria , Klein Eva 
Published: February 2007

AbstractViruses produced by two Moloney lymphoma sublines (Y and Yr), and their hybrids with a mouse L cell subline (YL and YrL) were tested for antigenic conversion and focus induction on JLS‐V9 and D56 (S + L −) cells. Two infectivity patterns were encountered. Both indicator cell lines were converted antigenically by the Y and YT viruses, whereas only D56 cells, and not JLS‐V9 cells, were converted by the Yr and YrL viruses. When infection of D56 cells was scored by both antigenic conversion and focus induction, further variations in infectivity patterns were found. The viruses produced by the YAC‐A9 and YACIR‐A9 hybrid cells (YL and YrL) appeared to be similar to the viruses produced by each of the lymphoma parents.
Cytotoxicity of human rosette‐forming blood lymphocytes on cultivated human tumor cells
Authors: Wybran Joseph , Hellström Ingegerd , Hellström Karl Erik , Fudenberg H. Hugh 
Published: February 2007

AbstractHuman peripheral blood lymphocytes from seven cancer patients were separated into two fractions, one rich in lymphocytes which could spontaneously form rosettes with sheep erythrocytes (T‐cells) and another poor in rosette‐forming cells. These two fractions were then tested for cytotoxic activity on cultivated tumor cells of the same histological type as the tumors of the respective lymphocyte donors. It was shown that T‐cell rich fractions had a higher cytotoxic activity than did the T‐cell poor fractions from the same patients. The findings indicate that human T‐cells can be cytotoxic, in vitro, against cultivated cells carrying tumor‐associated antigens.
S‐tropic murine type‐C viruses: Frequency of isolation from continuous cell lines, leukemia virus preparations and normal spleens
Authors: Lieber Michael M. , Sherr Charles J. , Todaro George J. 
Published: February 2007

AbstractA survey was undertaken to determine the prevalence of S‐tropic (xenotropic) murine type‐C viruses in continuous cell lines, leukemia virus preparations, and spleens of normal mice from various commonly used strains. Fifteen of 18 cell lines established from normal cells and transplantable tumors produced infectious type‐C viruses. For all cell lines examined, the viral isolates were either N‐, B‐, or NB‐tropic, while S‐tropic viruses were not detected. Two cell lines derived from normal tissues, however, had S‐tropic viruses which could be induced by treatment with 5‐bromodeoxyurdine, whereas cell lines derived from transplantable tumors were non‐inducible. Nine standard leukemia virus preparations likewise do not contain S‐tropic viruses. In contrast, S‐tropic viruses were recovered from spleens of normal weanling mice from six of 13 strains, indicating that the expression of S‐tropic virus is relatively common in disease‐free animals. The failure to find S‐tropic viruses in known preparations of leukemogenic murine type‐C viruses and their presence in tissues from normal animals suggest that S‐tropic viruses may play a normal physiologic role in mice.
In vitro cellular immunity to epstein‐barr virus in normal human subjects
Authors: Fimmel Peter J. , Lai Patrick K. , Keast David , Alpers Michael P. , Mackay‐Scollay Ewart M. 
Published: February 2007

AbstractLeukocyte migration inhibition was employed to study cell‐mediated immunity (CMI) to Epstein‐Barr virus (EBV) in 29 normal subjects. Anti‐EBV capsid antibody titres in these subjects ranged from 0 to 1:160. Extracts of seven human lymphoblastoid cell lines carrying EBV were evaluated as the source of test antigen. Of these cell lines studied, only P3HR‐1 proved suitable as a source of EBV antigen for use in the test. Undiluted tissue‐culture supernatant fluids of the EBV‐carrying cell lines P3HR‐1 and SH‐T1 caused only weak or equivocal migration inhibition in normal subjects; others tested were without effect. Antigen controls consisted of extracts of the Raji cell line, which contains the EBV genome but produces no EBV antigen, and cultured human cells with no known association with EBV, all of which failed to induce migration inhibition. Cellular controls consisted of EBV sero‐negative adult leukocytes and foetal cord blood leukocytes which did not respond to P3HR‐1 extract, although two of the five cord sera contained anti‐EBV capsid antibody. The migration inhibition response was antigen‐dose‐dependent and was not affected by anti‐EBV antibody capable of neutralizing the infectivity of EBV. These results show that CMI to EBV is present in normal individuals who have antibody to EBV capsid antigen.
Detection in human melanoma cell lines of particles with some properties in common with RNA tumour viruses
Authors: Parsons P. G. , Goss Patricia , Pope J. H. 
Published: February 2007

AbstractSix established lines of malignant melanoma cells produced particles having a buoyant density of 1.14 to 1.18 g/ml and containing RNA with a component of approximately 70S. Fractions containing these particles showed RNase‐sensitive DNA polymerase activity, and in simultaneous assays the DNA product was found to be associated with 70S RNA. Similar results were obtained in control studies with two known oncornaviruses (Rauscher and WM1‐B mouse leukaemia viruses), but not with particles from three normal human fibroblast strains. Filtration studies showed that the uridine‐labelled particles from four melanoma cell lines, as well as the materials from two melanoma lines active in the simultaneous assay, were largely retained by filters with an average pore diameter of 100–650 nm. In negative‐stained preparations of 1.14 to 1.18g/ml fractions from four melanoma lines, a small number of virus‐like particles about 125 nm in diameter were detected, as well as smaller amorphous material and minute ring‐like structures about 12–14 nm in diameter. The evidence strongly suggests the production by these cultured malignant melanoma cells of particles with properties closely resembling those of oncornaviruses. Although evidence was found of similar virus‐like particles in a malignant melanoma biopsy, their role in the aetiology of malignant melanoma remains unknown.
Polyamine metabolism in tumor, spleen and liver of tumor‐bearing rats
Authors: Marton Laurence J. , Heby Olle 
Published: February 2007

AbstractA brain tumor, originally induced by weekly IV injections of N‐nitro‐somethylurea in CD Fisher rats and subsequently carried in serial subcultures, was inoculated SC in the flank of CD Fisher rats. The synthesis and concentrations of the polyamines were studied at various times after the beginning of tumor growth. Higher activities of ornithine decarboxylase, S‐adenosylmethionine decarboxylase and higher concentrations of putrescine, spermidine and spermine were observed in the periphery when compared to the center of the solid tumor, and correlated with a higher growth rate in the periphery of the tumor. In the serum of rats with advanced tumors the concentration of spermidine was higher than in the serum of normal rats. Furthermore, putrescine was detectable in the serum of tumor‐bearing rats but not in normal rats. The tumor, which grows in a well‐defined non‐invasive manner, caused increased concentrations of putrescine and spermidine in spleen, and of spermidine in liver, at the time of most rapid growth. The increased polyamine concentrations may denote increased proliferation in the spleen and liver and are presumably part of an immunological response of the host animal to the growing tumor.
Immune cytolysis of murine tumor cells mediated by xenogeneic “Immune” RNA
Authors: Kern David H. , Pilch Yosef H. 
Published: February 2007

AbstractUsing a quantitative assay for lymphocyte‐mediated cytotoxicity, it was shown that normal, non‐immune C3Hf/HeCr mouse spleen cells were converted to effector cells specifically cytotoxic to chemically induced C3H tumor cells by incubation in vitro with “immune” RNA extracted from the lymphoid organs of specifically immunized guineapigs. This response was specific for the tumor used to immunize the RNA donor. Cytotoxicity indices (CIs) at 0.30 to 0.54 were consistently obtained. Spleen cells incubated with RNA from guinea‐pigs immunized with a different tumor, or with normal C3H tissue, failed to lyse the target cells. These immune responses were abrogated when the “immune” RNA was treated with RNase prior to incubation with the spleen cells. However, pre‐treatment with DNase or pronase did not alter the activity of the “immune” RNA. “Immune” RNA to a second chemically induced C3H tumor mediated a cytotoxic response to that tumor (CI=0.45), but not to the first tumor. This clearly demonstrates that xenogeneic “immune” RNA mediates tumor‐specific immune cytolysis, in vitro.
An analysis of variables affecting the measurement of tumor immunity In vitro with 125I‐iododeoxyuridine‐labelled target cells. Studies of immunity to primary moloney sarcomas
Authors: Seeger Robert C. , Rayner Sylvia A. , Owen John J. T. 
Published: February 2007

AbstractVariables affecting the measurement of immunity to adherent tumor cells in vitro have been analyzed using the immune response to primary Moloney sarcomas in BALB/c mice as a model system. IUdR, a gamma‐emitting isotope which is incorporated into the DNA of dividing tumor cells, was used to quantitate the number of adherent tumor cells in 0.2 ml cultures. Lymphoid cell‐mediated killing of tumor cells was measured by labelling tumor cells before they were cultured with effector cells (cytotoxicity test), and lymphoid cell‐mediated inhibition of tumor‐cell growth was measured by labelling those tumor cells surviving interactions with effector cells (cytostasis test). Addition of lymphoid cells to adherent tumor cells initiates complex interactions which have non‐specific (i.e., unrelated to recognition of tumor antigens) and specific (i.e., related to recognition of tumor antigens) effects on the survival and growth of tumor cells. The magnitude of these effects, as measured in the cytotoxicity or cytostasis tests, depends upon the number, kind, and state of activation and/or sensitization of effector cells and upon the number and susceptibility of tumor cells. Effector cells from control mice have only non‐specific effects whereas those from MSV‐immunized mice have both non‐specific and specific effects. Lymph‐node cells (LNC) from normal control mice non‐specifically kill IUdR labelled tumor cells in the cytotoxicity test, whereas killing and growth‐promoting influences are both present in the cytostasis test. Non‐specific cytotoxic effects also were mediated by LNC from MSV‐immunized mice, and these effects were of greater magnitude than those mediated by LNC from normal control mice. Our present and previous experiments suggest that non‐specific cytotoxicity of LNC is largely due to macrophages. In contrast, non‐specific promotion of tumor‐cell growth in the cytostasis test is apparently mediated by lymphocytes. Specific cytotoxicity or cytostasis was obtained only when non‐adherent LNC (NALNC) containing 99.8% lymphocytes and less than 0.2% macrophages were employed as effector cells. Although both cytotoxicity and cytostasis tests seem to give similar results, we conclude, for a number of reasons, that the cytotoxicity test is preferable for measuring cell‐mediated immune responses to adherent tumor cells. Our findings and conclusions should be generally applicable to studies of animal and human tumors.