bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization and partial purification of human milk fat globule membrane antigens by polyacrylamide gel electrophoresis and immunoblotting using monoclonal antibodies
Authors: Ashorn Per , Krohn Kai 
Published: February 2007

AbstractPolyclonal and monoclonal antibodies were used to characterize human milk fat globule (HMFG) membrane antigens, using gel filtration, ion exchange chromatography and western blotting. Although originally generated against HMFG, monoclonal antibodies also reacted with skim milk. In western blotting, several antigen molecules were seen, of which some were detected by all available antibodies, and one only with monoclonal antibody Ill D 5, previously shown to react with mammary and ovarian carcinomas bearing estrogen receptors. This or these antigens, with a molecular weight of about 53 kd, were isolated by fractionation in SDS‐PAGE. A low polypeptide content was demonstrated but the antigenic structure could be stained with periodic‐acid‐Schiff and biotinylated peanut agglutinin, indicating the presence of galactose or N‐acetylgalactosamine residues. While this 53‐kd molecule is the only determinant exclusively stained by III D 5 antibody, it is suggested that it carries epitopes related to estrogen receptor activation.
Transfection by human oncogenes: Concomitant induction of tumorigenicity and tumor‐associated membrane alterations
Authors: Collard J. G. , van Beek W. P. , Janssen J. W. G. , Schijven J. F. 
Published: February 2007

AbstractNIH 3T3 cells were transfected with DNA derived from human bladder carcinoma, colon carcinoma and HL60 promyelocytic leukemia cells. The transfectants were examined for the presence of human oncogenes in relation to tumorigenic potential and composition of surface‐located fucosyl glycopeptides by gel filtration, Concanavalin‐A‐binding and high‐performance liquid chromatography. All transfectants, harboring 3 different human cellular ras genes, appeared to be tumorigenic in nude mice and displayed characteristically altered glycopeptides. The surface glycopeptides were consistently changed to higher apparent molecular weight due to enrichment in higher‐branched sialic‐acid‐containing glycopeptides. Similar alterations have been found previously in virally‐ and chemically‐transformed cells in vitro and tumors raised in vivo, and were designated as cancer‐related or tumor‐associated glycopeptides. Revertants derived from HL60‐DNA‐induced transfectants, which had lost the transfected human N‐ras oncogene, simultaneously lost their tumorigenic potential and expression of cancer‐related membrane glycopeptides. In addition, spontaneous transformants, exhibiting morphology and growth patterns indistinguishable from those of tumor‐DNA‐induced transfectants, neither contained transferred human DNA sequences nor expressed cancer‐related glycopeptides. Nevertheless these cells were capable, after prolonged latency periods, of inducing tumors in nude mice. Cells derived from such tumors constantly displayed cancer‐related glycopeptides on their surface, suggesting selection of tumorigenic cells from spontaneous transformants during passage in nude mice. In one of these tumors at least, an endogenous mouse ras‐gene appeared to be activated. The results indicate a close correlation between the presence of activated ras‐oncogenes in the genome of the transfected cells, the tumorigenic potential of these cells and the expression of surface‐located cancer‐related glycopeptides. The data suggest that functions provided by human ras‐oncogenes contribute to the alteration of membrane glycopeptides on tumor cells.
Induction of HLA class‐II antigen expression on human carcinoma cell lines by IFN‐gamma
Authors: Schwartz Reinhard , Momburg Frank , Moldenhauer Gerhard , Dörken Bernd , Schirrmacher Volker 
Published: February 2007

AbstractThe effects of recombinant interferon gamma (IFN‐γ) on HLA antigen expression were examined in various human carcinoma cell lines: carcinomas of the lung (ChaGo, Oat 75, SK‐LC‐LL), colon (HT‐29, WiDr), larynx (HEp‐2), cervix (ME‐180) and mammary gland (AIAb). Surface expression of HLA antigens was determined using monoclonal antibodies directed against monomorphic determinants of HLA class II (HD II, 2.06) and HLA class I (W6/32) by several techniques including indirect immunofluorescence, immunoperoxidase assay, radioimmunoassay of cells, and immunoprecipitation of radioiodinated cells. Without previous exposure to IFN‐γ, HLA class‐II antigen was surface‐expressed on a small subpopulation of HEp‐2 only. All cell lines examined, except AIAb, could be induced to cell‐surface expression of HLA class‐II antigen after 48 hr incubation in the presence of IFN‐γ (10 units/ml). HLA class‐I antigen was present on all cell lines even without treatment, and it was increased after IFN‐exposure. Incorporation of 3H‐thymidine and 3H‐leucine and expression of the transferrin receptor were not significantly altered by IFN‐γ application, indicating a specific regulatory effect of IFN‐γ on HLA antigen expression. Our data demonstrate that HLA class‐II surface expression is inducible by IFN‐γ in a variety of epithelial tumor lines. This may have implications for the host immune system defense mechanisms against tumors.
Capacity of B‐lymphocytic lines of diverse tumor origin to produce and respond to B‐cell growth factors: A progression model for B‐cell lymphomagenesis
Authors: Gordon John , Åman Pierre , Rosén Anders , Ernberg Ingemar , Ehlin‐Henriksson Barbro , Klein George 
Published: February 2007

AbstractHuman cell lines established from cases of acute lymphoblastic leukemia, lymphosarcoma, Burkitt's lymphoma and multiple myeloma and representing stages of B‐lymphocyte development ranging from pre‐B through to plasma cells, were assessed for their ability to produce and respond to B‐cell growth factors (BCGF). All B‐cell lines studied were found to be constitutive producers of a growth activity which assisted the S‐phase entry of normal activated B‐cells and provided growth support for lymphoblastoid cells transformed by Epstein‐Barr virus. Furthermore, all lines responded by enhanced proliferation to supernatants from a BCGF‐producing T‐cell hybridoma. Not all lines, however, displayed autostimulation to their own supernatants and no tumor B‐cell line appeared totally dependent on soluble factors for its growth. Non‐tumorigenic B‐cell lines, by contrast, revealed a strict dependency on homologous growith factor for their continued proliferation in suspension culture. The findings support a progression model of lymphomagenesis based upon the utilization, production and, ultimately, emancipation from growth‐promoting soluble factors.
Common acquired naevi and the risk of malignant melanoma
Authors: Green Adèle , Maclennan Robert , Siskind Victor 
Published: February 2007

AbstractThe relationship between common acquired naevi and malignant melanoma of the skin was assessed in a case‐control study. In 183 patients and 183 controls matched for sex, age and area of residence, there was a strong association between the presence of pigmented naevi on the arms and melanoma. In comparison with persons having no naevi on the arms, the crude relative risk of melanoma was 28.0 when naevi were present. After adjusting for hair colour, propensity to sunburn and lifetime sun exposure, the final risk estimate was 30. 1. Family history did not appear to be a determinant of disease independent of the above risk factors.
Seroepidemilogy of human T‐lymphotropic retrovirus type I (HTLV‐I) in residents of niigata prefecture, Japan. Comparative studies by indirect immunofluorescence microscopy and enzyme‐linked immunosorbent assay
Authors: Aoki Tadao , Miyakoshi Hideo , Koide Hiroko , Yoshida Tsutomu , Ishikawa Hiroshi , Sugisaki Yuji , Mizukoshi Mikio , Tamura Kazue , Misawa Hirondo , Hamada Chuya , Ting Robert C. , Robert‐Guroff Marjorie , Gallo Robert C. 
Published: February 2007

AbstractA large sample of carriers of human T‐lymphotropic retrovirus type 1 (HTLV‐I) in Niigata Prefecture was examined for the detection of natural antibodies to HTLV‐I‐related antigens in sera using both indirect immunofluorescence microscopy (IFM) and enzyme linked immunosorbent assay (ELISA). The present findings are based on multiple surveys, using each assay technique at least twice. Although Niigata Prefecture has been considered a non‐endemic region for HTLV‐I, Sado Island has been proven by this study to be a relatively endemic pocket within this non‐endemic area. Seropositivity was highest in residents of Sado Island; 97/1, 117 (8.7%) by IFM and 33/1, 061 (3.1 %) by ELISA; followed by Niigata City, 18/650 (2.8%) by IFM and 16/638 (2.5%) by ELISA; and lowest in the remaining areas, 57/2, 631 (2.2%) by IFM and 20/2, 551 (0.8%) by ELISA. Seropositivity was demonstrated in 172/4, 398 (3.9%) by IFM and 69/4, 250 (1.6%) by ELISA in Niigata Prefecture taken as a whole. In general, the incidence of seropositive residents increased gradually with age. The sex difference was not significant. The serum samples tested were categorized into 4 groups; (1) IFM and ELISA both positive, (2) IFM positive but ELISA negative, (3) IFM negative but ELISA positive, and (4) IFM and ELISA both negative. By absorption tests, IFM and ELISA seemed to recognize different specific antibodies in sera; IFM recognized antibodies to HTLV‐I‐related cellular antigens in addition to HTLV‐I‐viral antigens, but ELISA recognized antibodies to HTLV‐I viral antigens alone. Thus, IFM detected a broader spectrum of antigens, resulting in recognition of more positive sera than those detected by ELISA.
Biosynthesis of alpha fetoprotein by MCF‐7 human breast cancer cells
Authors: Sarcione Edward J. , Hart Darleen 
Published: February 2007

AbstractDirect evidence was obtained for de novo synthesis of AFP by MCF‐7 human breast cancer cells per se. Synthesis was demonstrated by L‐14C‐leucine and L‐35S‐methionine incorporation into immunochemically isolated AFP, and confirmed by radioimmunodiffusion and radioimmunoelectrophoresis. This information indicates that AFP synthesis is associated with normal and neoplastic cells of several different histotypes, and suggests that AFP detected and measured previously in primary human breast cancer tissue cytosol (Sarcione et al., 1983) also resulted from in situ biosynthesis by breast cancer cells per se rather than uptake of exogenous AFP originating from extracellular sources. Evidence that AFP obtained after treatment of 14C‐leucine radiolabelled MCF‐7 breast cancer cell protein with 0.4 M KC1 contained 2.6 times more radioactivity than did AFP obtained before such salt treatment is interpreted as indicating that two different molecular species of de novo synthesized AFP existed in breast cancer cells: (1) larger amount of non‐immunoreactive AFP which became immunoreactive and measurable after KC1 treatment, and (2) smaller amounts of free immunoreactive AFP. 14C‐radiolabelled AFP obtained before and after treatment of cell protein with 0.4 M KC1 codiffused, comigrated with alpha, electrophoretic mobility and gave an identical radioimmunologic reaction both with each other and with added carrier human cord serum AFP. Furthermore, preliminary studies indicated that radiolabelled non‐immunoreactive AFP could be separated from lower‐molecular‐weight free AFP by chromatography on Sephadex G‐200. Taken together, these findings suggest that synthesized free AFP was bound as a non‐immunoreactive high‐molecular‐weight macromolecular complex rather than being covalently linked. Our current working hypothesis is that most of the de novo synthesized endogenous AFP in MCF‐7 human breast cancer cells was rapidly and reversibly bound by hydrophobic bonding to a specific cytoplasmic AFP‐receptor.
Effect of cyclosporin‐A (CsA) on the ability of T lymphocyte subsets to inhibit the proliferation of autologous EBV‐transformed B cells
Authors: Bejarano Maria Teresa , Masucci Maria Grazia , Ernberg Ingemar , Klein Eva , Klein George 
Published: February 2007

AbstractWe have analyzed the effect of Cyclosporin‐A (CsA) on the in vitro suppression of Epstein‐Barr virus (EBV)‐induced B‐cell proliferation exerted by autologous T‐lymphocyte subpopulations separated on the basis of cell density. CsA abolished the growth‐inhibitory capacity of high‐density T cells but influenced only marginally the activity of low‐density lymphocytes; this suggested that different mechanisms mediate suppression in the two subsets. Stimulation with irradiated EBV‐transformed cells had a different impact on the activity of low‐ and high‐density lymphocytes. Proliferative and cytotoxic responses were inversely correlated, i.e. high‐density cells proliferated but exerted low cytotoxicity, while the lytic activity of the low density subset was stronger in the absence of significant cell proliferation. Proliferation and generation of cytotoxicity were abrogated by CsA in both subsets. The activities could be restored by addition of exogenous IL‐2, suggesting that the drug may interfere with the cascade of lymphokine–cell interactions which leads to activation of immune responses. From the analysis of the CsA effects on the two subsets it seems that the high‐density one contains specific memory T cells which are activated and proliferate upon encounter with EBV‐infected cells. On the other hand, low‐density lymphocytes are induced to release soluble factors with antiproliferative activity. The secretory function was resistant to the suppressive effect of CsA.
Production of β‐human chorionic gonadotrophin by human squamous carcinoma cell lines
Authors: Cowley Gerard , Smith John A. , Ellison Morag , Gusterson Barry 
Published: February 2007

AbstractEight out of 9 human squamous carcinoma cell lines ectopically secrete the beta subunit of human chorionic gonadotrophin (β‐HCG) in amounts detectable by radioimmunoassay. In contrast, both normal and SV40‐transformed keratinocytes show no such evidence of β‐HCG secretion. Ectopic β‐HCG is identical in its gel exclusion and high‐performance liquid chromatographic properties to placental β‐HCG and, in radioimmunoassay, yields a dilution curve parallel to that of placental β‐HCG. Dibutyryl cyclic AMP, but not sodium butyrate, stimulates β‐HCG secretion by the one human cell line examined, LICR‐LON‐HN‐5, suggesting that ectopic production by these cells is similar to trophoblastic β‐HCG secretion, and differs from most other non‐trophoblastic cell lines previously examined.
Immunogenicity of melanoma‐associated gangliosides in cancer patients
Authors: Tai Tadashi , Cahan Leslie D. , Tsuchida Tetsuya , Saxton Romaine E. , Irie Reiko F. , Morton Donald L. 
Published: February 2007

AbstractThe immunogenicity of gangliosides found on human melanoma cells was determined from sera of 26 melanoma patients who were immunized every 1–4 weeks for 4 months with tumor‐cell vaccine (TCV) prepared from cultured melanoma cells. Total lipidbound sialic acid in the gangliosides isolated from TCV was 0.38 μmol/108 cells, and was distributed as follows: 44.8% to GM3, 44.2% to GD3, 5.6% to GM2, and 4.6% to GD2. Sera were tested at monthly intervals for antibodies to each ganglioside by ELISA with purified gangliosides as the antigen source. The immunologic specificity of the antibody was confirmed by absorption tests. None of the 26 patients had detectable anti‐GM3, anti‐GD3, or anti‐GD2 antibodies before immunization, although anti‐GM2 antibody was detected in 3 patients. After immunization, 2 patients developed IgM anti‐GD2, 10 developed IgM anti‐GM2, and 2 developed IgG anti‐GM2 antibodies. No patient developed detectable anti‐GM3 or anti‐GD3 antibodies. These results indicate that both GD2 and GM2 expressed on human melanoma cells are immunogenic in humans, although GM2 appears to be more immunogenic. The other two gangliosides, GM3 and GD3, are present in human sera and in human normal tissues, and thus immunologic tolerance may have been established against these gangliosides. Alternatively, circulating GM3 and GD3 may have neutralized anti‐GM3 and anti‐GD3 antibodies, if any were induced by TCV immunization.
Methylation pattern of human T‐cell leukemia virus in vivo and in vitro: pX and LTR regions are hypomethylated in vivo
Authors: Kitamura Toshio , Takano Masako , Hoshino Hiroo , Shimotohno Kunitada , Shimoyama Masanori , Miwa Masanao , Takaku Fumimaro , Sugimura Takashi 
Published: February 2007

AbstractThe methylation patterns of the gag, pol, env, pX and LTR regions of proviral DNA of human T‐cell leukemia/lymphoma virus type I (HTLV) in fresh leukemic cells and established cell lines were examined using Hpall/Mspl endonuclease. Peripheral blood lymphocytes (PBL) isolated from patients with adult T‐cell leukemia/lymphoma (ATL) did not express viral antigens of HTLV, but PBL that had been cultured for 2 days did express these viral antigens. Most parts of the gag, pol and env regions of the HTLV provirus in PBL isolated from 12 ATL patients and PBL cultured for 2 days were hypermethylated as reported by others. In contrast, in 10 established cell lines that harbored HTLV genomes and expressed viral antigens, HTLV proviruses were hypomethylated. In one cell line, ATL‐IK, which harbored an HTLV genome but did not produce viral antigens, the gag, pol and env regions were hypermethylated. However, two Hpall sites, one in the middle of the gag region and the other in the middle of the pol region, were not methylated even in PBL from most ATL patients. Furthermore, the pX and LTR regions were hypomethylated not only in established cell lines but also in PBL of ATL patients. The hypomethylation of the pX and LTR regions detected in fresh leukemic cells of ATL patients may have some etiological significance in cell transformation by controlling the level of transcription of these regions, or modulating the binding of some factors to these regions.
Sauna, dust and migration as risk factors in lung cancer among smoking and non‐smoking males in Finland
Authors: Tenkanen Leena , Hakulinen Timo , Hakama Matti , Saxén Erkki 
Published: February 2007

AbstractTo study possible causes of the high lung cancer incidence among Finnish males, the Finnish Cancer Registry and the Cancer Registry of Norway in 1962 performed a population survey covering smoking habits, occupational and residential history and, in Finland, sauna habits. The cohort of 4,475 Finnish men has now been followed up for incidence of lung cancer in 1964–1979. The relative importance of 3 factors–sauna baths, occupational exposure to dust, and migration to urban areas–was studied in different smoking categories. Among smokers of ≥ 25 g/day, takers of frequent saunas (more than once a week) displayed some excess risk (RR 1. 7). In smokers an increased risk was also found among those exposed to dust (RR 1.3), and those who had migrated to urban areas (RR 1.8, when compared to native urban population). Dust exposure and migration factors act synergistically with smoking. Migration was the only factor apart from smoking to show a substantial population‐attributable risk, which amounted to 10%.
Adoptive immunotherapy of intracerebral murine lymphomas: Role of different lymphoid populations
Authors: Romani L. , Nardelli B. , Bianchi R. , Puccetti P. , Mage M. , Fioretti M. C. 
Published: February 2007

AbstractIn an attempt to elucidate the cellular mechanisms responsible for the therapeutic activity of systemic immunotherapy in an adoptive transfer system, lymphoma cells were implanted i. c. It was found that, upon peripheral injection of cytotoxic T‐lymphocytes with specificity for the tumor, the cells reached and infiltrated the diseased brain but did not accumulate selectively in the malignant graft. In order to accomplish significant tumor inhibition, the infused lymphocytes, largely expressing the Lyt‐1 +2+ phenotype, apparently cooperated with radioresistant phagocytic cells present in histocompatible hosts and athymic mice.
The relationship between tumour geometry and the response of tumour cells to cytotoxic drugs — An in vitro study using EMT6 multicellular spheroids
Authors: Kwok T. T. , Twentyman P. R. 
Published: February 2007

AbstractMulticellular spheroids of the EMT6/Ca/VJAC mouse mammary tumour cell line have been used in an investigation of the effect of tumour geometry on the response of tumour cells to 3 cytotoxic drugs, adriamycin (ADM), nitrogen mustard (HN2) and CCNU. In addition to the inherent cellular drug response, factors related to spheroid structure, namely cell‐cycle distribution, intercellular contact, drug penetration and microenvironment (PH, oxygen, glucose, etc.) are believed to influence the response of cells within spheroids to cytotoxic drugs. Selective enzymatic dissociation (with bacterial neutral protease) has been used to separate the cells within large ( ≈ 800 μm in diameter) spheroids into 4 distinct subpopulations. The cells within the subpopulations have been characterized by their DNA content, RNA content, tritiated thymidine labelling in dex, cell size and clonogenic capacity. It was found that cells at the surface of spheroids are relatively larger and more proliferative than cells towards the centre while their clonogenic capacity is similar. Studies on the response of EMT6/Ca/VJAC log and plateau‐phase monolayer cells have been carried out in parallel and have shown that cycling cells are more sensitive to ADM and HN2 than are non‐cycling cells but somewhat less sensitive for the response to CCNU. Since the response patterns of cells from different regions of spheroids to HN2, treated either before disaggregation (intact spheroid) or after disaggregation (isolated spheroid cells), are similar and the surviving fraction increases from the surface towards the centre of the spheroid, cell cycle distribution is thought to be the only factor involved in the cytotoxicity of HN2 towards cells within the spheroids. Although the patterns of response to ADM of cells within intact spheroids and isolated spheroid cells are similar to those for HN2, the initial slope of the curve for intact spheroids is much steeper than that of the isolated spheroid cells. Therefore, in addition to the factor of cell‐cycle distribution, drug penetraction also appears to be involved in the action of ADM on spheroids, while the factors of intercellular contact and microenvironment appear to be relatively less important. The reverse pattern was found for the response of cells within different regions of spheroids to CCNU, treated as intact spheroids or as isolated spheroid cells (i. e., greater killing of inner compared with outer cells). There was, however, a much greater differential effect when treatment was carried out on intact spheroids compared with isolated spheroid cells. As 14C‐CCNU is found to be distributed consistently through out the whole spheroid, both cell‐cycle distribution and changes in the cellular microenvironment within the spheroids appear to play important roles in the response of cells within spheroids to CCNU.