bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibitory effects of phenolics, teas and saliva on the formation of mutagenic nitrosation products of salted fish
Authors: Stich Hans F. , Chan Peter K. L. , Rosin Miriam P. 
Published: February 2007

AbstractThe objectives of this study were to simulate in vitro some of the conditions that may prevail in man during the ingestion of a meal and to quantitate the inhibitory effect of phenolics and phenolic‐containing beverages on the formation of mutagenic nitrosation products. The test system consisted of nitrosating (pH 2, 1 h, 37°C) an aqueous fraction of a salt‐preserved Chinese fish (Pak Wik) with or without the inhibitors to be tested and estimating the frequency of his+ revertants per survivor of Salmonella typhimurium (strain TA1535). The phenolics and teas were added to the nitrosation mixture. Catechin, chlorogenic acid, gallic acid, pyrogallol and tannic acid suppressed the formation of mutagenic nitrosation products. The inhibitory efficiency was comparable to that of ascorbic acid. A Japanese, a Chinese and a Ceylonese tea also prevented the formation of mutagenic nitrosated fish products at doses which are usually consumed by man. Moreover, saliva exerted an inhibitory effect. The inhibitory effect was not additive when the phenolics or saliva were added concurrently to the nitrosation mixture. The possibility that phenolics are involved in the apparent chemopreventive effect of fruits and vegetables is discussed.
A monoclonal antibody marker of human primitive endoderm
Authors: Williams L. K. , Sullivan A. , McIlhinney R. A. J. , Neville A. M. 
Published: February 2007

AbstractMonoclonal antibodies were raised against the human germ‐cell tumor line, LICR LON HT39/7. The cells of this human embryonal carcinoma cell line were first fixed in formol saline and then dehydrated prior to immunization so that antibodies were produced which reacted with antigens surviving conventional histological processing. Eleven hybrid clones secreted antibody that reacted with both formol saline‐fixed and living cells of the immunogen. One of these antibodies, LICR LON FC 10.2, has been found to react with a membrane glycoprotein of molecular weight 200,000 restricted in distribution to the surfaces of undifferentiated teratoma‐derived cell lines, the luminal surface of human fetal intestine and bronchus and areas of putative endodermal differentiation within germcell neoplasms.
Cell‐mediated immunity to Epstein‐Barr virus (EBV) and natural killer (NK)‐cell activity in the X‐linked lymphoproliferative syndrome
Authors: Harada Shinji , Bechtold Thomas , Seeley Janet K. , Purtilo David T. 
Published: February 2007

AbstractThe activity of T‐cell‐mediated immunity to Epstein‐Barr virus (EBV) was assessed by an assay of regression of the outgrowth of EBV‐infected autologous B cells. Regression and natural killer (NK)‐cell activities were compared for patients and their mothers from five families with X‐linked lymphoproliferative syndrome (XLP) and three control groups. Seven of the 10 patients with XLP exhibited weak T‐cell activity against autologous EBV‐infected lymphoblastoid cell lines (LCL) comparable to EBV‐seronegative controls. In contrast, 8 of 10 obligate carrier females of XLP had unusually strong activity, which was comparable to anti‐early‐antigen (EA) positive controls. The results of the regression assays correlated with their EBV serology: mothers showed high titers, and their affected sons showed low‐titer EBV‐specific antibody responses. Defective NK‐cell activity was found only in the patients with XLP. NK and regression activities did not correlate. Our findings explain, in part, the vulnerability to EBV of males with XLP and why their mothers are protected from life‐threatening phenotypes of XLP.
Characterization of stable spontaneous metastatic variant lines of RSV‐transformed mouse fibroblasts
Authors: Renzo Maria Flavia Di , Bretti Sergio 
Published: February 2007

AbstractThe correlation between metastatic potential and a series of biological properties was investigated in two mouse fibrosarcoma lines (SR‐BALB and B77–3T3), transformed by different strains of Rous sarcoma virus (RSV). In the absence of selective pressure the metastatic potential was different in the two lines. The SR‐BALB sarcoma did produce both spontaneous metastases from s.c. site and i.v. lung colonization with a high incidence (respectively in 60% and 80% of treated animals). Conversely, the metastatic incidence of the B77–3T3 sarcoma was much lower. Differences in lung implantation between the two lines turned out to be even greater when the number of colonies growing in the lung was evaluated. Organ distribution of cells after i.v. injection, tumorigenicity, growth rate in vivo and in vitro, plating efficiency in liquid medium and cloning efficiency in semi‐solid agar medium were evaluated in the two lines. A strict correlation was found only between the metastatic potential and the capability of growth in 0.6% (“hard”) agar. Such a correlation was supported by the isolation in “hard” agar of highly metastasizing subclones of the low‐metastasizing B77–3T3 line.
Embryo‐derived teratocarcinoma. IV. The role of immune factors in the regulation of teratocarcinogenesis
Authors: Damjanov Ivan , Bagasra Omar , Dominis Mara , Solter Davor 
Published: February 2007

AbstractSeven‐day‐old mouse embryos were transplanted under the kidney capsule of adult syngeneic recipients which were either X‐irradiated, treated with cyclophosphamide, splenectomized or immunized with teratocarcinoma cell lines prior to embryonic transplantation. The yield of malignant tumors was decreased in preirradiated, as well as in cyclophosphamide‐pretreated animals, as compared with untreated hosts. The effect of the pre‐treatment could be fully abrogated by allowing animals to spontaneously recover for 4 weeks or by adoptive transfer of thymus cells from untreated animals. Partial recovery was obtained by the adoptive transfer of spleen cells. Splenectomy at the time of embryonic transplantation did not affect the embryo‐derived teratocarcinogenesis in C3H mice but reduced the yield of malignancy and the weight of tumors produced in C57BL/6 mice. Immunization of hosts with teratocarcinoma cells did not influence the subsequent embryo‐derived teratocarcinogenesis. These data indicate that embryo‐derived teratocarcinogenesis is regulated by X‐ray and cyclophosphamide‐sensitive cells residing in the thymus and the spleen. The permissiveness to teratocarcinogenesis seems to be a function of the total number of these regulatory cells in the host.
Altered adhesiveness of tumor cell surface variants with reduced metastasizing capacity – reduced adhesiveness to vascular wall components in culture
Authors: Tao Tien‐Wen , Johnson Lorin K. 
Published: February 2007

AbstractHeterotypic adhesiveness of surface variant clones of B‐16 melanoma cells exibiting different metastasizing capacity was studied with respect to components of the vascular wall in culture including endothelial (E) and smooth muscle (SM) cells from adult bovine aorta, and the extracellular matrices laid down by them. The ricinresistant cells (ricinR) and the wheat‐germ agglutininresistant (WGAR) cells, both of which showed reduced hematogenous metastases in vivo, showed reduced adhesiveness specifically to endothelial cells and extracellular matrices. This reduced heterotypic adhesiveness is in contrast to the homotypic adhesive properties in which respect the ricinR cells had similar values to the parental cells, while the WGAR cells had much higher values than the latter. There appeared to be a positive correlation between metastasizing capacity and specific adhesiveness to E cells and the extracellular matrix surfaces.
Phytohemagglutinin inhibits phorbol diester promotion of UV‐irradiation initiated transformation in syrian hamster embryo cells
Authors: Dipaolo J. A. , Evans C. H. , Demarinis A. J. , Doniger J. 
Published: February 2007

AbstractPhytohemagglutinin (PHA) or either of its isolectins, erythroagglutinin or leukoagglutinin, causes a dose‐dependent decrease in 12‐O‐tetradecanoylphorbol 13‐acetate (TPA)‐promoted transformation of Syrian hamster embryo cells, but has no effect on transformation induced by ultraviolet irradiation. The ineffectiveness of concanavalin A indicates that not every lectin inhibits TPA. Galactose, a dominant sugar in receptors for PHA binding, reverses the inhibition of TPA promotion caused by PHA but galactose does not inhibit TPA promotion itself. Therefore, the TPA and PHA binding sites are functionally discrete. The PHA inhibition of TPA‐promoted transformation is reversible because PHA is only effective if present with TPA, whereas lymphotoxin, an immunologic hormone, has a persistent anti‐carcinogenic effect, regardless of whether it is added before or after TPA. PHA in conjunction with lymphotoxin causes additional inhibition of TPA‐promoted transformation. PHA and lymphotoxin affect the biological activity of TPA by diverse mechanisms. Lymphotoxin alters the physiological state of the cell, causing a change in the cellular response to TPA. PHA may affect either the binding of TPA to a critical cellular receptor for promotion or a later step in promotion.
Effect of elicitation on peritoneal macrophage subpopulations: Size distributions, ectoenzyme phenotypes and antitumor activity
Authors: Morahan Page S. , Rozner Marc A. , Jessee Ellen J. 
Published: February 2007

AbstractResident (R), Brewer's thioglycollate broth (TG) and C. parvum (CP)‐elicited murine peritoneal cell populations were separated into subpopulations by centrifugation on discontinuous Ficoll gradients consisting of layers of 4, 6, 8 and 10% Ficoll. The resulting subpopulations were shown to be distinct on the basis of cell size, ectoenzyme phenotypes and antitumor activity. The cell size distributions were analyzed by means of a Coulter channelyzer and software developed for a computer. The 4–6% Ficoll interface fraction comprised the smallest macrophages, with most cells in this subpopulation appearing to range in cell volume from 150–275 μm3. The largest sized macrophages were found in the 10%‐pellet fraction, with most cells appearing to range in cell volume from 300–600 μm3. The ectoenzyme phenotypes of the R, TG and CP unseparated macrophage populations were significantly different. Moreover, the ectoenzyme phenotypes of the smallest, (4–6% Ficoll interface) subpopulation in the R and CP macrophages differed from the other subpopulations. Reduction in alkaline phosphodiesterase I (APD‐I) ectoenzyme activity (as compared with unseparated R macrophages) appeared to be a marker for acquisition of antitumor activity. The small CP macrophages (4–6% Ficoll interface) showed no antitumor activity while the unseparated CP macrophages and all other CP macrophages subpopulations exhibited antitumor activity. The CP macrophage unseparated population and the subpopulations with antitumor activity expressed reduced ADP‐I activity. Conversely, the R or TG macrophage unseparated populations and their subpopulations, along with the CP macrophage 4–6% subpopulation, lacked antitumor activity and failed to show a change in ADP‐I ectoenzyme activity.
Antitumor effects of interferon in mice injected with interferon‐sensitive and interferon‐resistant friend leukemia cells. I.
Authors: Belardelli F. , Gresser I. , Maury C. , Maunoury M.‐T. 
Published: February 2007

AbstractInterferon‐sensitive (745) and interferon‐resistant (3Cl‐8) Friend leukemia cells (FLC) are highly tumorigenic for DBA/2 mice. The phenotype of interferon sensitivity or resistance does not change with in vivo passage. Daily administration of mouse interferon markedly enhanced the survival time of mice injected with either 745 or 3Cl‐8 cells. Use of quantitative methods for determining the number of FLC (colony formation in agarose and immunofluorescence) permitted us to show that potent, partially purified or highly purified mouse interferon (s.a. 0.5 to 1 × 109 u/mg protein) induced a 100‐ to 1,000‐fold decrease in the number of tumor cells in the peritoneal cavity in the days following inoculation of 745 or 3Cl‐8 cells. Interferon decreased the number of FLC even when treatment was initiated at a time when tumor cells were multiplying exponentially in the peritoneal cavity. There was no evidence that interferon acted as an inducer of FLC differentiation in vivo. The finding that interferon was equally effective in mice inoculated with interferonresistant cells as in mice inoculated with interferon‐sensitive cells suggests that in this experimental system interferon does not act directly on the tumor cells, but that the interferon‐induced antitumor activity is mediated by the host.
Activation of the EBV‐cycle and aggregation of human blood lymphocytes by the tumor promoters teleocidin, lyngbyatoxin a, aplysiatoxin and debromoaplysiatoxin
Authors: Eliasson L. , Kallin B. , Patarroyo M. , Klein G. , Fujiki H. , Sugimura T. 
Published: February 2007

AbstractA variety of tumor promoters such as the phorbol esters were found to be capable of inducing the viral cycle in cell lines latently infected with Epstein‐Barr virus (EBV). We tested two classes of new tumor promoters; indole alkaloids and polyacetates, for their ability to induce the synthesis of the Epstein‐Barr virus determined early antigen (EA) complex. Teleocidin and lyngbyatoxin A are indole alkaloids. Aplysiatoxin and debromoaplysiatoxin are polyacetates. Of these four tumor promoters all but debromoaplysiatoxin induced the synthesis of the EA complex. However, in combination with 3 mM n‐butyrate, all four induced EA synthesis. The potent tumor promoters teleocidin, lyngbyatoxin A and aplysiatoxin induced maximal synthesis of EA at the concentration of 5 to 10 ng/ml, whereas the weak tumor promoter debromoaplysiatoxin required a concentration of 250 ng/ml to achieve maximal induction. Phorbol esters induce quick morphological changes and aggregation of human blood lymphocytes. The latter phenomenon has been interpreted as the expression of a “cell binding phenotype” (Patarroyo et al., in press). We showed that all four promoters induced aggregation of human lymphocytes at similar concentrations. The induction seemed to be a common effect which could be induced by both strong and weak tumor promoters.
Insensitivity to interferon of two subclones of human endometrial carcinoma cell line, HEC‐1
Authors: Morinaga Naoko , Yonehara Shin , Tomita Yoshimi , Kuwata Tsuguo 
Published: February 2007

AbstractTwo cloned cell lines, HEC‐IC and HEC‐ID, derived from the human endometrial adenocarcinoma cell line HEC‐I, were found to be as resistant to the antiviral and anticellular activities of interferon (IFN) as were the parental cells, and 2′‐5′ oligoadenylate (2‐5A) synthetase was not induced in these clones by IFN treatment. They were sensitive to the cytotoxicity of natural killer (NK) cells but their sensitivity was not changed by treatment of the cell lines with IFN. Binding of [3H]‐leucine‐labelled IFN‐a to HEC‐IC cells was examined, and Scatchard plot analysis showed that HEC‐IC cells did not have any high‐affinity binding sites for IFN‐a. The cells had hyperploid chromosomes. HEC‐IC had three copies of chromosome 21 while HEC‐ID had only one copy of chromosome 21. The results suggest that these clones may have the structural gene for the IFN receptor but that functional receptor sites may be absent.
Modulation of natural killer (NK) cell activity during FLV‐P virus infection of mice
Authors: Migliorati Graziella , Jezzi Teresa , Frati Luigi , Bonmassar Enzo , Rossi Giovanni B. , Garaci Enrico , Riccardi Carlo 
Published: February 2007

AbstractWe analyzed the effects of a polycythemic substrain of Friend leukemia virus, i.e. the FLV‐P virus, on splenic NK activity of DBA/2 susceptible mice. One day after virus injection a significant increase of NK activity was found, which persisted until day 10. On the other hand, 14‐21 days after virus injection a marked and significant depression of activity was measured. This depression was associated with the appearance of suppressor cells able to inhibit the lytic activity of untreated splenocytes when mixed in vitro in the 4 h 51Cr‐release assay. The suppressor cell population was insensitive to treatment with anti‐Thy 1.2 plus complement, was adherent to Sephadex G‐10 and nylon, but did not adhere to plastic, suggesting it is neither a T‐cell nor a typical macrophage. The possible relevance of NK activity modulation in relation to the induction of leukemia is discussed.
Distribution of the transferrin receptor in normal human fibroblasts and fibrosarcoma cells
Authors: Ekblom Peter , Thesleff Irma , Lehto Veli‐Pekka , Virtanen Ismo 
Published: February 2007

AbstractTransferrin is required for proliferation of most cells in culture. This effect is presumably mediated by the binding of transferrin to its receptor, a surface glycoprotein which is preferentially expressed by actively growing cells. Here we show that normal human fibroblasts cultured in serum, and other media containing transferrin express transferrin receptors in a distinctly non‐random way: punctate foci of the receptor were seen only at the leading lamellae of the cells, whereas cells grown without serum, or in transferrin‐depleted serum showed a random distribution of the receptor. In contrast, malignant fibrosarcoma cells showed the receptor uniformly throughout the cell surface in all media tested, including those containing transferrin. The data suggest that the ligand causes a directional lateral movement of the receptor in normal but not in malignant cells. Application of the receptor antibody caused a rapid internalization of the receptor in both cell types.
Establishment and characterization of a human non‐secretory plasmacytoid cell line and its hybridization with human B cells
Authors: Ritts R. E. , Ruiz‐Argüelles Alejandro , Weyl Karin G. , Bradley Anne L. , Weihmeir Bernadette , Jacobsen Deborah J. , Strehlo Bonnie L. 
Published: February 2007

AbstractA human non‐secretory plasmacytoid cell line has been established for 6 years in more than 170 passages. Over 300 passages have been made from several early and late passages. The cell line is karyotypically normal, easily grown and has the characteristic features of a non‐secretory plasmablast. Its characteristics suggest its use for hybridization by new methods as well as a study of its secretory defect. HPRT‐negative phenotypic mutants can be derived from this line and a single polyploid clone has also been isolated. Hybridization with the HPRT+ and HPRT‐ lines X human B cells is described.
Pregnancy‐associated alpha2 glycoprotein (α2PAG) synthesis by human breast cancer tissue and cultured cell lines
Authors: Sarcione Edward J. , Delluomo Daniel , Zloty Martin 
Published: February 2007

AbstractElevated α2PAG serum levels are found in pregnant women and patients with diverse types of neoplasms including breast cancer. Primary human breast cancer tissue, MCF‐7 and BT‐20 human breast cancer cultured cell lines were shown to synthesize α2PAG in vitro. BT‐20 breast cancer cells also released this pregnancy‐associated protein. Synthesis was demonstrated by l‐[14C]‐leucine incorporation into immunochemically isolated protein and confirmed by radioimmunodiffusion and radioimmuno‐electrophoresis. These data (1) provide direct evidence for α2PAG synthesis by well‐characterized human breast cancer cells per se;(2) strongly suggest that at least part of the α22PAG synthesis observed in primary human breast cancer tissue in vitro was due specifically to breast cancer cells rather than exclusively to monocytes/mac‐rophages known to infiltrate neoplastic tissues and to produce this protein during pregnancy; and (3) are consistent with the conclusion that serum α2PAG is a definite breast cancer “marker protein” which originates from and reflects breast cancer status. On the basis of the association of elevated serum α2PAG levels in breast cancer patients, its known immunosuppressive activity in vitro, and the direct evidence for α2PAG synthesis by human breast cancer cells perse, we postulate that this protein plays an important immunoregulatory role in vivo to prevent immune rejection and/or destruction of breast cancer cells.
Radioimmunoassay of prostatic acid phosphatase: Validation and clinical application
Authors: Franchimont P. , Bouffioux Ch. , Reuter A. , Rigo‐Betz Ch. , Vrindts‐Gevaert Y. , Jaspar J. M. , Lecomte‐Yerna M. J. 
Published: February 2007

AbstractA radioimmunoassay for prostatic acid phosphatase (PAP) has been established, using a purified preparation extracted from human seminal plasma. To obtain immunologically intact 125I‐PAP as a tracer, the lactoperox‐idase technique was used followed by double chromatography on Sephadex G‐50 and G‐200. The assay was sensitive, accurate and reproducible. Only leukocyte acid phosphatase cross‐reacted completely whilst acid phosphatases from other tissues (skin, lymph nodes, lung, kidney, liver, testis, platelets) did not interfere in the assay. When this method was used, PAP levels in men over the age of 20 were greater than those of women and younger men. Patients with prostatitis, benign prostatic hypertrophy (BPH) and other prostatic disorders had normal levels in more than 95% of cases. Patients who had prostatectomy for BPH had levels significantly lower than those of normal controls and those with unoperated BPH. This provides indirect evidence for the specificity of the PAP radioimmunoassay. In prostatic cancer, PAP levels measured by radioimmunoassay were more frequently and more greatly elevated with progression of the disease: 25% atstages A and B, 75% at stage C and 100% at stage D. Further, PAP measurement provided a quantitative marker to follow therapeutic response as PAP levels varied in parallel with clinical, radiologic and scintigraphic progression. Under our experimental conditions, the PAP radioimmunoassay proved to be more sensitive (percentage of increased levels in the serum of patients with prostatic cancer) and more specific (percentage of normal levels in the serum of patients with prostatic disorders other than cancer) than the enzymatic assay of these enzymes.
Transformation‐enhancing activity in plasma of tumor patients: Relationship with fibronectin fragments
Authors: De Petro Giuseppina , Barlati Sergio , Vartio Tapio , Vaheri Antti 
Published: February 2007

AbstractHuman plasma cryoprecipitates (cryos) of tumor patients have been shown to contain transformation‐enhancing factors (TEF)4, able to promote morphological cell transformation in vitro. A similar activity is associated with proteolytic fibronectin fragments retaining the gelatin‐binding site. We have now studied whether similarities exist between TEF found in cryos and the fibronectin fragments. Of 14 TEF‐positive tumor cryos tested, 13 (including carcinomas, leukemias, lymphomas and myelomas) retained their activity in the gelatin‐binding fraction, and in one the activity was not recovered. In one case of myeloma, TEF activity was detected only in the gelatin‐binding fraction and not in the starting cryo. In contrast, none of the TEF‐negative control samples tested, obtained from healthy donors and patients affected by different non‐malignant diseases, showed any TEF activity in the gelatin‐binding or ‐nonbinding fractions. The TEF‐positive gelatin‐binding fractions of tumor cryos were active even at the concentration of ∼ 50 ng/ ml. The presence of fibronectin in human plasma cryos was detected using immunoblotting. In the gelatin‐binding fractions, fibronectin antigenicity was seen in the position of intact fibronectin subunits (Mr = 220,000) and different fragments (Mr = 50,000‐200,000). while the gelatin‐binding fractions contained a single antigenic polypeptide (Mr ∼94,000). The TEF activity of cryo, as well as that of plasminolytic digest of purified plasma fibronectin, could be inhibited by fibronectin antibodies. The data suggest that the' TEF activity present in tumor patient plasma cryoprecipitates is related to gelatin‐binding fragments of fibronectin.