bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sensitivity of cultured human pancreatic carcinoma cells to dihydroxyanthracenedione
Authors: Fountzilas George , Gratzner Howard , Lim Lori O. , Yunis Adel A. 
Published: February 2007

AbstractWe tested the effectiveness of dihydroxyanthracenedione (DHAD) on cell growth of two human pancreatic carcinoma cell lines MlA PaCa‐2 and PANC‐1. At the level of ID50, the drug was almost equally effective against both cell lines. When the time exposure of MIA PaCa‐2 cells to the drug was increased from 1 h to continuous exposure for 5 days, the ID50 was decreased about three‐fold only (1.4 × 10−8 M and 4 × 10−9 M respectively). At the level of ID50 also the difference between 6 h exposure and continuous exposure for 5 days was minimal. In equimolar concentrations and with 1 h exposure, DHAD was more effective against MIA PaCa‐2 cells than other chemotherapeutic agents including adriamycin, mitomycin‐C, 5‐FU, vincristine, vindesine, vinblastine, VP‐16–213, bleomycin, cis‐platinum, asparaginase and acivicin. In concentrations of 5 × 10−7 M, DHAD caused about 40% inhibition of 14C‐thymidine incorporation of MIA PaCa‐2 cells. Treatment of MIA PaCa‐2 cells with the ID50 of DHAD for 1 h caused retardation of cellular traverse, with the major effect appearing to be in G2+M phase of the cycle. From these data DHAD appears to be a potent drug against human pancreatic carcinoma in vitro.
A scoring system for wilms' tumour: Pathological study of the second medical research council (MRC) trial
Authors: Marsden H. B. , Lawler W. , Carr T. , Kumar S. 
Published: February 2007

AbstractThe second MRC nephroblastoma trial was devised to determine whether more intensive chemotherapy in the early stages and multiple chemotherapy in the poorer prognosis groups would give improved results. As a separate study the pathological and clinical aspects were assessed to see whether information may be obtained concerning the behaviour of individual tumours of the 159 cases included, 142 were regarded as nephroblastoma. Significant features were the age of the patient, clinical stage at diagnosis, tubular status of the neoplasm and the presence or absence of anaplasia. A scoring system has been devised to take account of these factors.
Effects of indomethacin on the growth of cultured mammary tumors
Authors: Fulton Amy M. 
Published: February 2007

AbstractWe have studied the relative prostaglandin E (PGE)' synthesizing abilities of a number of mammary tumor liners cultured in vitro. These lines differ in a number of biologic characteristics including tumorigenicity, immunogenicity and metastatic potential. They also synthesize different levels of PGE and these levels are in the same relative order seen in sit The metastatic tumor lines 4526 and 410.4 synthesize more PGE than does the non‐metastatic tumor line 410. Syntheticactivity of all lines decreases with time in culture. Relative synthetic capacity is not correseen with the slowest wowing (68H) and fastest growing (4526) cell lines. lndomethacin is able to inhibit the synthesis of PGE in vitro in a dose‐dependent manner and the presence of indomethacin in of cell division.
Further characterization of marek's disease virus‐infected lymphocytes. I. In vivo infection
Authors: Calnek B. W. , Schat K. A. , Ross L. J. N. , Shek W. R. , Chen C‐L. H. 
Published: February 2007

AbstractPrevious reports from this laboratory identified bursa‐derived lymphocytes (B cells) and non‐B cells as the predominant cell types respectively involved in the early cytolytic and subsequent latent infection of chickens with Marek's disease virus (MDV). It was not known whether these differences were qualitative or quantitative or if the method for detection of latent infection (viral antigen production after 48 h of in vitro cultivation) was sensitive enough. To further define the cells involved in the various phases of MDV infection, we used monoclonal antibodies which specifically react with B cells, or T cells, or la‐antigen‐bearing cells. Dual fluorescence tests to detect surface markers and viral internal antigen (VIA) were conducted with infected spleen cell freshly collected from MDV‐infected chickens or after in vitro cultivation of those cells. The same antibodies were also used for a rosetting procedure to yield fractions enriched or depleted of T cells, B cells or la‐bearing cells. These were examined directly for viral DNA by in situ hybridization or dot blot DNA hybridization and for VIA cultivation. We learned that infected T cells also comprise part of the early cytolytic phase of MDV infection but constitute a minority population (approximately 2–3%) compared to B cells (83–92%) at 3 or 4 days post infection. Latently infected cells were definitively identified as mostly la‐bearing T cells, although a few (2–4%) were B cells. Prior to in vitro cultivation, latently infected cells apparently had insufficient viral DNA for detection by in situ hybridization, but the more sensitive dot blot procedure revealed viral DNA in fractions later found positive by VIA expression after in vitro cultivation. Viral DNA replication in latently infected cells apparently had occured after 48 h cultivation because in situ hybridization detected infected cells at that time. Treatment of cell cultures with iodo‐deoxyuridine, 12‐O‐tetradecanoyl phorbol‐13‐acetate or n‐butyrate failed to increase the number of spleen cells which expressed VIA.
Immuno‐selection In vivo of H‐2D phenotypic variants from a metastatic clone of sarcoma cells results in cell lines of altered metastatic competence
Authors: Katzav S. , Segal S. , Feldman M. 
Published: February 2007

AbstractTo find out whether manipulation of H‐2 expression on metastatic cells could alter their metastatic properties, we immunoselected in vivo H‐2 antigen variants from a metastatic clone of the T10 sarcoma [originating in a (C57BL/6 XC3H.eB)F1 mouse] and tested their metastatic capacity. The unselected metastatic cells (IE7) were previously found to express H‐2Db and H‐2Dk antigens, but they did not express the H‐2K antigens of either parental haplotype. Transplantation of IE7 cells into C57BL/6J irradiated mice resulted in loss of H‐2Dk expression and a reduction in H‐2Db antigen density. Further transplantation of these cells into non‐irradiated C57BL/6J mice led to a total loss of H‐2 expression. The cells concomitantly lost their metastatic potency. Immunoselection of IE7 cells in C3H.eB irradiated and non‐irradiated mice resulted in cells which were H‐2Dk‐positive but H‐2Db‐negative. Cells of these selected variants not only retained their metastatic potential, but in fact were far more metastatic than the unselected IE7 cells. Thus, changes in H‐2 expression on tumor cells may alter their metastatic potential. In the case of T10 cells, H‐2Dk expression seems to be directly involved in their metastatic capacitiy.
Preparation and properties of a mouse monoclonal antibody (W14A) to human chorionic gonadotropin
Authors: Searle F. , Partridge C. S. , Kardana A. , Green A. J. , Buckley R. G. , Begent R. H. J. , Rawlins G. A. 
Published: February 2007

AbstractA mouse monoclonal antibody, W14A, has been prepared which reacts with intact human chorionic gonadotropin and its beta‐subunit, showing less than 2% cross‐reactivity towards the alpha‐subunit and 0.5% cross‐reactivity towards the beta‐subunit of luteinizing hormone. The reagent is suitable for the radioimmunolocalization of choriocarcinoma and trophoblastic teratoma in humans. A preliminary radioimmunoassay has been developed.
Age and cohort effects in primary liver cancer
Authors: Stevens Richard G. , Merkle Elle J. , Lustbader Edward D. 
Published: February 2007

AbstractPrimary liver cancer incidence data from 30 populations reported in Cancer Incidence in Five Continents were analyzed. After adjustment for time trends, log incidence increases linearly with log age. Liver cancer risk increases more rapidly with age than that of colon cancer, stomach cancer, or lung cancer in non‐smokers; it increases less rapidly than that of prostatic cancer or of lung cancer in smokers. Over the past 20 years, most populations have been found to have increasing age‐adjusted liver cancer incidence. There is no correlation between change in rates and magnitude of rates. Male rates are higher than female rates and the ratio of the two tends to be higher in high‐risk areas.
Triplication of one chromosome no. 15 with an altered C‐myc containing ecori fragment and elimination of the normal homologue in a T‐cell lymphoma line of akr origin (TIKAUT)
Authors: Wirschubsky Zvi , Wiener Francis , Spira Jack , Sümegi Janos , Klein George 
Published: February 2007

AbstractAn ouabain‐ and thioguanine‐resistant subline (TIKAUT) of spontaneous AKR lymphoma, TKA, was trisomic for chromosome 15 and contained a single 33 kb EcoRI fragment, containing the oncogene c‐myc. The original TKA lymphoma and derived in vitro line contained the same 33 kb fragment, as well as a normal 22 kb fragment. It has been concluded that the original 15‐trisomic TKA tumor has duplicated a 15‐chromosome that contained the changed fragment, while maintaining the normal fragment as well. Subsequently, in the derived TIKAUT line, the changed chromosome duplicated again, giving rise to three copies, and the normal homologue was eliminated altogether. This confirms our earlier somatic hybrid study showing that the duplicated 15‐chromosome of a T‐cell leukemia confers an advantage on the cell that favors tumorigenicity, whereas the normal homologue exerts a counteracting influence. Therefore, in the course of tumor progression, the changed chromosome tends to be amplified, whereas its normal homologue tends to be eliminated.
The inhibitory effects of horse anti‐rat AFP antiserum on the uptake of 2‐deoxy‐D‐glucose by AFP‐producing rat hepatoma cells
Authors: Ohkawa Kiyoshi , Tsukada Yutaka , Hibi Nozomu , Hirai Hidematsu 
Published: February 2007

AbstractThe inhibitory effect of horse antiserum against rat alpha‐fetoprotein (AFP) on the uptake of 2‐deoxy‐D‐glucose (2dG) by the AFP‐producing rat ascites hepatoma AH66 cells was studied. AH66 cells cultured in medium containing 20% heat‐inactivated antiserum had a 1.5‐fold lower rate of sugar uptake than did AH66 cells which were cultured in medium containing 20% heat inactivated normal horse serum. The inhibition of 2dG uptake by antiserum was dependent on both the concentration and the exposure time of antiserum. Preincubation of AH66 tumor cells for 2 and 6 h with antiserum prior to the measurement of 2dG uptake resulted in a 70.1% and 58.2% decrease in 2dG uptake compared to control cells. Antiserum did not inhibit the rate of phosphorylation of 2dG by tumor cells. Kinetic constants for the uptake of 2dG in both AH66 cells treated with antiserum to AFP and in control cells were calculated from Lineweaver‐Burk plots. The Km remained constant at approximately 1.2 mM, but the Vmax was twice as small for the cells treated with antiserum as for the control cells (571 vs 923 nanomoles/2 × 10s cells/min). These studies suggest that the inhibition of 2dG uptake by treatment with antiserum was the result of a decrease in the number of transport sites, or a decrease in the amount of carrier protein for the sugar which was present on the surface of the plasma membrane of the AH66 cells.
Glycoconjugates of murine tumor lines with different metastatic capacities. I. Differences in fucose utilization and in glycoprotein patterns
Authors: Schwartz Reinhard , Schirrmacher Volker , Mühlradt Peter F. 
Published: February 2007

AbstractSince various experimental findings point towards an important role of cell surface carbohydrates ‐ in particular sialic acid ‐ in cancer metastasis, the rationale of this study was to look for possible differences in carbohydrate metabolism and glycoprotein expression in well‐defined related tumor lines of different metastatic capacity. The tumor lines analyzed were L5178Y E (=Eb), a low‐metastasizing, methylcholanthrene‐induced lymphoma of a DBA/2 mouse, and L5178Y ES(=ESb), a spontaneous high‐metastatic variant thereof. A non‐related, highly metastasizing tumor, MDAY‐D2, and ConA‐stimulated spleen cells were included in the study. These cell lines were compared for incorporation rates of various labelled carbohydrates and for glycoprotein patterns in SDS‐polyacry‐lamide gels. Marked differences were observed in the incorporation of 3H‐fucose, while the incorporation of 3H‐glactose and 3H‐mannose was similar inthe different cell lines studied. Only the metastatic variant ESb incorporated 3H‐fucose at a rate similar to that of ConA‐stimulated T‐cell blasts. Eb cells did not incorporate 3H‐fucose while MDAY‐D2 had a significantly lower 3H‐fucose incorporation rate. Separation and purification of the intracellular products of 3H‐fucose by gel filtration and high‐voltage electrophoresis revealed in Eb cells a block in the synthesis of fucosylated glycoproteins at the step of the fucose‐I‐P‐guanylyttransferase. No apparent defect in the fucose pathway was detectable in MDAY‐D2 cells. An Eb → ESb shifted cell line regained the ability to incorporate 3H‐fucose. All tumors displayed unique glycoprotein patterns in SDS‐PAGE. Labelling with 3H‐mannose revealed the most distinct bands, while labelling with 3H‐galactose gave fewer and broader bands. Although clonal instability of metastasizing tumor variants has been frequently reported, subclones of Eb and ESb showed characteristics similar to those of the original cell lines with regard to metastatic capacity, fucose metabolism and glycoprotein expression. These results will be discussed in relation to differences in fucose metabolism and in surface expression of fucose as observed in other tumor systems consisting of high‐ and low‐metastatic lines.
Characterization of the fbr‐murine osteosarcoma virus complex: FBR‐MuSV encodes a fos‐derived oncogene
Authors: Michiels L. , Maisin J. R. , Pedersen F. S. , Merregaert J. 
Published: February 2007

AbstractThe FBR murine osteosarcoma virus complex, isolated from a radiation‐induced osteosarcoma of an X/Gf mouse causes the rapid appearance of osteosarcomas in newborn mice and transforms fibroblasts in vitro. The two components of the FBR‐viral complex have been isolated separately in tissue culture: FBR‐MuLV by end‐point dilution and FBR‐MuSV by the establishment of mouse [FBR‐NP117 (NIH 3T3)] and rat non‐producer cell lines [FBR‐NP415 (REF)]. The host range and RNase TI fingerprint analysis of FBR‐MuLV demonstrated a pattern closely related to, but distinguishable from, Akv‐MuLV. Transformed cells from both mice and rats contain a rescuable FBR‐MuSV genome. These pseudotypes produce foci in tissue culture and induce osteosarcomas in susceptible mouse strains. An FBR‐MuSV (FBR‐MuLV) cDNA probe detects a 5.2 kb Hindlll and a 9.5 kb EcoRI FBR‐MuSV‐specific fragment in FBR‐MuSV‐transformed non‐producer rat cells. The same fragments hybridized with a fos specific probe, demonstrating that FBR‐provirus contains a c‐fos‐derived onc‐gene.
Evidence for a transforming growth factor(S) in the serum‐free conditioned medium of SV40‐transformed 3T3 fibroblasts
Authors: Pirozzi Suzanne , Young Delano V. 
Published: February 2007

AbstractUnlike untransformed 3T3 fibroblasts, Simian Virus 40‐transformed 3T3 cells (SV3T3) do not require the presence of exogenous polypeptide mitogens in order to become competent for the initiation of DNA synthesis. As an explanation for this state of perpetual competence, growth activity for 3T3 cells was found in the serum‐free conditioned medium of SV3T3 cells. This activity, which is abolished by incubation with pepsin, but withstands to a fair degree denaturants (8 M urea and 4 M guanidinium HCI) and a reducing agent (65 mM dithioerythritol), enhances the growth of Swiss and BALB/c 3T3 cells in 1% (v/v) calf serum medium and ensures the complete survival of Swiss 3T3 cells for several days in the total absence of serum. The growth activity appears to be derived from the SV3T3 cells, since it is not found in the non‐conditioned medium (and the insulin and transferrin components of this serum‐free medium have only weak growth activity alone) and the chances of it being due to residual serum growth factors are slight because of the method of growing the cells and the collection of the conditioned medium. Moreover, in a separate experiment to test the possible involvement of cell attachment factors, rat fibronectin was found not to affect 3T3 growth in the standard growth assay. The conditioned medium growth activity apparently has the biological capabilities of transforming growth factors. After concentration by ammonium sulfate precipitation, it can stimulate DNA synthesis in confluent, quiescent Swiss 3T3 cells, in both the absence and presence of 10% depleted calf serum. It also permits the growth of large colonies of Swiss 3T3 cells in soft agar. As part of a preliminary characterization of the conditioned medium growth activity, gel filtration in 0.15 M NaCl, 0.001 M HCl resolves the activity into high (mol. wt. ≥ 100,000) and low (mol. wt. 5,000–6,000) molecular weight factors. Since re‐chromatography of the nigh molecular weight factor, which may still be in an aggregated form, does not generate the smaller, the latter is not a dissociation product of the former. The precise relationship of these SV3T3‐conditioned medium growth factors to other growth factors, including known transforming growth factors, has not yet been determined.
Hormone‐dependent enhancement of neoplastic phenotype expression by MuMTV‐infected heterologous cells, and MuMTV‐induced cellular antigens
Authors: Kryukova I. N. , Litvinov S. V. 
Published: February 2007

AbstractA new property, i.e. acquisition of insulin (insulin + dexa‐methasone)‐mediated enhancement of anchorage independence by heterologous MuMTV‐infected cells, is described. Hormone‐mediated anchorage‐independent growth enhancement in MuMTV‐infected cells is followed by expression of a cell‐surface antigen, recognized by allogeneic (C3H→AKR) anti‐Thy 1.2 antigen serum. The absorption test and the use of monoclonal antibody to the Thy 1.2 antigen showed that hormone‐dependent antigen on the cell surfaces of experimentally and naturally MTV‐infected cells was different from the Thy 1.2 antigen itself. Utilization of anti‐p53 ( protein of transformation ) monoclonal antibody enabled us to identify this cell membrane antigen as p53.
Modifying influences of betel quid ingredients on B(a)P‐induced carcinogenesis in the buccal pouch of hamster
Authors: Rao A. Ramesha 
Published: February 2007

AbstractThe present study evaluates the incidence of tumors in hamster buccal pouches following short‐term (10 days) and long‐term (6 months) topical exposures to graded doses of benzo(a)pyrene, B(a)P (25 μg, 50 μg and 100 μg per pouch either daily for 10 days or thrice weekly for 6 months) alone or in combination with extract of tobacco (1 mg/pouch, twice daily), betel nut (1 mg/pouch, twice daily) or betel leaf (5 mg/pouch, twice daily). Given alone, the three doses of B(a)P respectively yielded, 6 months after the last treatment, 4%, 8.7% and 16.7% tumors in the short‐term study, and 20%, 35% and 61% tumors in the long‐term study. Short‐term treatments with individual ingredients of betel quid did not produce any tumors while long‐term treatments produced tumors only with tobacco (17.6%) and betel nut (10.5%). When B(a)P and betel quid ingredients were painted concomitantly for 10 days, there was, depending upon the dose of B(a)P, complete or partial suppression of tumor production. But when B(a)P‐plus‐tobacco or B(a)P‐plus‐betel nut treatments were given for 6 months, there was a considerable increase in tumor incidence. Betel leaf extract, in both short‐term and long‐term studies, expressed its inhibitory influence on B(a)P‐induced tumorigensis.
Plasminogen activators, activation inhibitors and alpha2‐macroglobulin produced by cultured normal and malignant human cells
Authors: Saksela Olli , Vaheri Antti , Schleuning Wolf‐Dieter , Mignatti Paolo , Barlati Sergio 
Published: February 2007

AbstractIn the present paper we have characterized the plasminogen activators (PA) synthesized by 25 different human cell lines. Technically easy methods were adopted for concentration and immunological characterization of the activators even in the presence of PA inhibitors. Most cell lines produced u‐PA (mol. wt 55,000), melanoma and HeLa cells t‐PA (mol. wt 66,000) and two carcinoma cell lines and normal skin fibroblasts produced no detectable PA. The classical 125I‐fibrin method was compared to a caseinolytic assay and some of the discrepancies between results obtained with the two methods were shown to be due to cell‐derived NaDodSO4‐sensitive proteinase inhibitors in culture media. Additionally, synthesis and uptake by the cells of the wide‐spectrum proteinase inhibitor alpha‐2‐macroglobulin (alpha2M) were studied by radioimmunoassay and immunofluorescence. No production of alpha2M could be measured in any of the malignant cell lines. In normal cells no correlation existed between the production of alpha2M and the observed inhibition of PA activity, which indicates that other proteinase inhibitors are produced by the cells.
Preparation and characterization of monoclonal antibodies against placental alkaline phosphatase and other human trophoblast‐associated determinants
Authors: Travers Paul , Bodmer Walter 
Published: February 2007

AbstractWe have prepared monoclonal antibodies by immunizing BALB/c mice with purified human term placental plasma membranes. The antibodies were selected to show predominant specificity for trophoblast and trophoblast derivatives. Four of these antibodies have been found to recognize the placenta‐specific isozyme of alkaline phosphatase (EC 3.1.3.1), and to cross‐react with the closely related testis form of this enzyme. One antibody recognized transferrin, a serum protein with an abundant placental receptor. The specificities of the other antibodies, whose target antigens are unknown, are described. Their reactivity with some human tumour‐derived epithelial cell lines suggests that they may provide useful markers of human trophectoderm differentiation, as well as for properties selected for during tumour progression.