bluuebunny/crossref_metadata_2025_split huggingface dataset:
A prospective study of plasma prolactin levels and subsequent risk of breast cancer
Authors: Kwa H. G. , Cleton F. , Wang D. Y. , Bulbrook R. D. , Bulstrode J. C. , Hayward J. L. , Millis R. R. , Cuzick J. 
Published: February 2007

AbstractPlasma prolactin was measured in 2,572 premenopausal, 628 menopausal, and 1,666 peri‐ and postmenopausal women who were apparently healthy. Breast cancer was subsequently diagnosed in 47 of these women at a median time of 5 years after blood collection (pre‐cancer cases). Prolactin levels in pre‐menopausal cases increased significantly with age whereas this was not found in matched controls. The perimenopausal cases were characterized by extreme variability in prolactin levels. In post‐menopausal women who developed breast cancer, the prolactin levels were significantly elevated, being at or above the 70th percentile for the controls. In this group the results are consistent with prolactin acting as a late‐stage tumour promoter.
Coffee and ovarian cancer
Authors: Trichopoulos Dimitrios , Papapostolou Michail , Polychronopoulou Antonia 
Published: February 2007

AbstractNinety‐two women with common epithelial tumors of the ovary and 105 comparison women admitted for various orthopedic conditions were interviewed regarding demographic, socio‐economic and biomedical characteristics, including their use of coffee and tobacco. There was no association between tobacco smoking and ovarian cancer. However a statistically significant trend association was noted between coffee drinking and ovarian cancer (p ∼ 0.03). The association could not be explained in terms of any other variable included in the present study. The relative risk for women drinking two or more cups of coffee per day was 2.2 with 95% confidence limits 1.0–4.8. Several descriptive epidemiologic data are compatible with a causal association between coffee and ovarian cancer.
Cyclosporin A permits the distinction between specific T and NK activity generated in A human MLC
Authors: Landegren Ulf , Ramstedt Urban , Axberg Inger , Örn Anders , Wigzell Hans 
Published: February 2007

AbstractHuman lymphocytes, activated in mixed lymphocyte culture (MLC), express cytolytic activity against a range of target cell types. Cyclosporin A (CyA) efficiently prevents the development of cytotoxic T cells directed against target cells expressing the phenotype of the stimulator cells whilst not preventing an increase in natural killing (NK) activity measured against tumor targets. The drug was further shown not to influence the short‐term induction of increased NK activity by interferon. Already established T killer cells are not sensitive to CyA. The drug thus seems to be selectively involved in the induction of immune responses requiring T‐cell proliferation.
Use of an agar culture technique for establishing lymphoid cell lines from Marek's disease lymphomas
Authors: Payne L. N. , Howes K. , Rennie M. , Bumstead Janene M. , Kidd A. W. 
Published: February 2007

AbstractLymphoblastoid cell lines derived from Marek's disease (MD) lymphomas have been established with difficulty by a number of workers. We have compared with conventional liquid culture methods the efficiency of a new technique for establishing lymphoid cell lines in which lymphoma cells were cultured initially in agar medium. Cells from 39/79 lymphomas gave rise to loose lymphoid colonies in the seeded agar after 7 days' incubation at 41°C. Two types of macrophage colony also developed. When lymphoid colonies in agar were transferred to liquid culture, 23/39 gave rise to permanent lymphoid cell lines, compared with 8/33 comparable cultures initiated in liquid medium. Twenty‐nine new cell lines have been developed from Rhode Island Red, line 6 and line 7 chickens. All carry T‐cell markers and the MD tumour‐associated surface antigen (MATSA) and showed variable but low responsiveness to lectin mitogens. The new cell lines, when first established, consisted mainly of small, lymphocytoid cells but, after varying times, these changed into typical lymphoblastoid lines and an increased expression of an embryonic antigen was associated with this change. The lymphocytoid line cells were more slowly growing and densitydependent than were the lymphoblastoid cells, and lymphocytoid lines grew better at 41°C and lymphoblastoid lines better at 37°C. MD virus could be rescued from some of the lines but others appeared to be true nonproducers.
The site of integration of the herpes simplex virus type 1 thymidine kinase gene in human cells transformed by an HSV‐1 DNA fragment
Authors: Kit Saul , Hazen Marion , Otsuka Haruki , Qavi Hamida , Trkula David , Dubbs Del Rose 
Published: February 2007

AbstractTo analyze the site of integration of the herpes simplex virus type 1 (HSV‐1) thymidine kinase (TK) gene in biochemically transformed human cells, TK‐HeLa‐(BU25) cells were transformed to the TK+ phenotype by a cloned, 2 kbp Pvull fragment of HSV‐1 DNA. The transformed cells [HeLa(BU25)/TF pAGO PP3] were fused with mouse LM(TK−) cells, and human‐mouse somatic cell hybrid clones (LH PP3 clones 1,2,3,5 and 6) were isolated in HATG‐ouabain selective medium. The HeLa(BU25)/TF pAGO PP3 cells and the LH PP3 hybrid clones expressed HSV‐1‐specific TK activity and a her‐pesvirus‐associated nuclear antigen, and contained herpesvirus nucleotide sequences. Molecular hybridization experiments were carried out to map the HSV‐1 and flanking cellular nucleotide sequences in the biochemically transformed cells. These experiments demonstrated that the HSV‐1 nucleotide sequences were integrated at a single site, and that the same cellular nucleotide sequences flanked the viral DNA in transformed HeLa(BU25)/TF pAGO PP3 and LH PP3 clone 5 cells. TK− revertant subclones isolated by growing the LH PP3 clone 5 cells in BrdUrd (and diphtheria toxin) failed to form colonies in HATG medium, but retained HSV‐1 nucleotide sequences. Isozyme analyses on 21 gene‐enzyme systems representing 21 human chromosomes revealed that all of the LH PP3 clonal lines expressed human hexosaminidase B, which has been assigned to chromosome 5, and all were sensitive to diphtheria toxin, which is also a marker for chromosome 5. Chromosome analyses showed that chromosome 5 was the only human chromosome present in mitoses of LH PP3 clone 5 cells and that human chromosome 5 was present in most of the mitoses of LH PP3 clone 1,2,3, and 6 cells. The latter clones also contained 1 or 2 additional human chromosomes in some of the cells. As expected from the molecular hybridization analyses, TK− revertants of LH PP3 clone 5 cells retained portions of chromosome 5 and expressed human hexosaminidase B. The results indicate that HSV‐1 nucleotide sequences were stably integrated in the biochemically transformed cells, most likely in human chromosome 5.
Relationship between fibrin clot retraction and tumorigenesis in C3H/10T1/2 cells
Authors: Azzarone B. , Brouty‐Boyé D. , MacIeira‐Coelho A. 
Published: February 2007

AbstractFibrin clot retraction (FCR) was studied in C3H/10T1/ 2 murine fibroblasts. These cells were able to induce FCR with high efficiency during resting phase as well as during active growth. C3H/10/T1/2 cells which became tumorigenic after X‐irradiation lacked FCR activity. Non‐tumorigenic revertant clones regained the capacity to induce FCR, while revertants which progressively back‐reverted to the neoplastic state showed intermediate FCR activity. These unstable revertants, when again fully tumorigenic, completely lost FCR activity.
Chromosome rearrangements involved in the origin of trisomy 15 in spontaneous leukemia of AKR mice
Authors: Herbst E. W. , Gropp A. , Tietgen C. 
Published: February 2007

AbstractTrisomy 15, known to be the predominant chromosome abnormality in leukemic cells of the AKR strain, develops even in animals of the subline AKR/RblAld with two constitutive Robertsonian translocation chromosomes (6.15). Among 10 leukemic animals of this subline exhibiting chromosomal anomalies, 6 showed trisomy of the whole Robertsonian translocation chromosome with the expression of combined trisomy 6 and 15 as the most frequent abnormality. Besides this, rearrangements were observed in five animals, most of them resulting from centric fission of the Rb (6.15) translocation chromosome. Trisomy 15 with two Rb (6.15) and an extra acrocentric 15 was found in 44% of spleen cells in one animal, and a new Rb translocation of chromosomes II and 15 was seen in 50 % of spleen and thymus cells of another animal. In both cases trisomy 15 without simultaneous trisomy 6 resulted. Thus, the triplication of a whole Rb (6.15) is frequent in leukemic AKR/Rb (6.15)1 Aid, and ensuing double trisomy 6 + 15 is tolerated by the leukemic cell. But the development of trisomy 15 combined with centric fission of Rb (6.15) without simultaneous trisomy 6 is another principle realized in leukemogenesis.
Suppression of natural killer (NK) activity by splenic adherent cells of low NK‐reactive mice
Authors: Riccardi Carlo , Santoni Angela , Barlozzari Teresa , Cesarini Carla , Herberman Ronald B. 
Published: February 2007

AbstractAdherent cells with the ability to inhibit NK activity were found in the spleens of young 8‐week‐old SJL/J mice. Such suppressor cells were also found in the spleens of other low‐NK‐reactive strains, but not in the spleen of age‐matched high‐NK‐reactive strains. These suppressor cells had the characteristics of macrophages, since they were plastic‐ and nylon‐adherent, phagocytosed latex and iron particles, and were resistant to treatment with anti‐Thy‐1.2 serum plus complement. Their inhibitory activity appeared to be due to their production and/or release of soluble suppressive factor(s). Their suppressor activity was similar to that of pyran copolymer‐activated macrophages, which were previously shown to be suppressive for cytotoxicity by NK cells. We suggest here that macrophages may be involved in the physiological regulation of NK activity and may contribute to the low NK activity in some strains of mice.
Specific cytotoxicity against autologous tumour and proliferative responses of human lymphocytes grown in interleukin 2
Authors: Vose Brent M. , Bonnard Guy D. 
Published: February 2007

AbstractPeripheral blood lymphocytes of cancer patients were sensitized in vitro to autologous tumour cells in mixed lymphocyte‐tumour culture (MLTC). Blast cells were isolated on discontinuous Percoll gradients from MLTC which showed significant stimulation of [<3>H]‐thymidine incorporation. Cultured T cells (CTC) were derived from these blasts by growth in conditioned medium containing interteukin‐2 (IL‐2) and maintained for up to 51 days by repeated feeding with IL‐2 and in some cases by addition of irradiated allogeneic blood mononuclear cells as “fillers”. These cultures showed specific cytotoxic reactivity against autologous tumour and in only a few cases was natural killing (NK) of K562 cells apparent. Restimulation of CTC with tumour was measured in primed lymphocyte tests (PLT). Increased uptake of [<3>H]‐thymidine was found upon stimulation by autologous tumour and allogeneic tumour of the same site and histology but there was no response to non‐related tumours or to a panel of allogeneic lymphocytes. No sensitization to autologous HLA D/DR could be detected by restimulation or cytotoxicity against monocytes in the majority of cases. These data suggest that, by careful selection of sensitised blasts from MLTC, it is possible to obtain CTC with both helper (proliferative) and cytotoxic T cells and that such CTC have specific reactivity against tumour cells. These cellular reagents will be useful in defining the antigenicity of human neoplasms and possibly in therapy.
Establishment of B‐lymphoblastoid cell lines from Marek's disease virus‐induced tumors in turkeys
Authors: Nazerian K. , Elmubarak A. , Sharma J. M. 
Published: February 2007

AbstractFour lymphoblastoid cell lines were established from tumors of turkeys inoculated with high doses of the GA strain of Marek's disease virus (MDV). Unlike other MD lymphoblastoid cell lines of chicken origin, these MDV transformed turkey lines appear to be B lymphocytes and produce immunoglobulin. Growth characteristics of these cell lines are slightly different; however, they all produce low levels of MDV‐specific antigen and carry the complete genome of the virus as determined by virus rescue in the chicken or in duck embryo fibroblast cultures. These cell lines are pathogenic for chickens and produce virus‐induced MD lesions. All four lines are free of the herpesvirus of turkeys, reticuloendotheliosis virus, and three lines are also free of avian leukosis virus. They all have typical normal turkey chromosomes and are positive for Marek's disease tumor‐associated surface antigen.
Production and characterization of marmoset lymphoblastoid interferon
Authors: Abb Jochen , Abb Hannelore , Deinhardt Friedrich 
Published: February 2007

AbstractWe describe the production of marmoset lymphoblastoid cell interferon (IFN). Optimal yields of IFN were obtained when EBV‐transformed lymphoblastoid cell lines (LCL) at a cell density of 1 × 106/ml were incubated with 100 HAU Sendai virus/ml for 24 h. Sendai‐virus‐induced marmoset lymphoblastoid cell IFN was acid‐stable and exerted antiviral activity on both homologous and heterologous human cells, thus allowing its classification as IFN α. Marmoset lymphoblastoid cell IFN did not inhibit the growth of herpesvirus‐transformed marmoset T‐ or B‐cell lines, but markedly enhanced marmoset NK‐cell activity against human myeloid leukemia target cells. The use of lymphoblastoid cell IFN in marmosets in vivo may contribute to an understanding of the pathogenic role of IFN in herpesvirus‐induced lymphoproliferative diseases.
The mechanism of genetic resistance to marek's disease in chickens
Authors: Powell P. C. , Mustill Brenda M. , Rennie M. , Lee Lucy F. 
Published: February 2007

AbstractGenetic resistance to Marek's disease in RPL line‐6 chickens is expressed not only at the level of host immunological responses against virus and tumour antigens, but also at the level of target lymphoid cells for virus infection and transformation. The nature of the target cell involved was investigated. Spleen cells from susceptible line‐7 chickens adsorbed more Marek's disease virus and turkey herpesvirus in vitro than line‐6 spleen cells. In the case of Marek's disease virus this was reflected in the replicative ability of the virus in vivo. Transplantation of thymus fragments from 1‐day‐old line‐7 chickens into thymectomized line‐6 chickens conferred a high degree of susceptibility on the latter, but the transplantation of spleen or bursa fragments had no significant effect. The reverse procedure, i.e. grafting of line‐6 thymi into line‐7 chickens, did not diminish the susceptibility of the recipients. In each treatment group the observed titres of leukocyte‐associated viraemia correlated with the susceptibility of the group to Marek's disease. Histologically the grafted thymus fragments became depleted of lymphocytes immediately after transplantation. By 6 days there was substantial recovery, apparently as a result of repopulation of the thymic epithelium by host stem cells. This was confirmed by transplanting thymus fragments between individuals of opposite sexes. Karyotype analysis showed that the thymus contained lymphocytes of the sex of the recipient. However, karyotype analysis of lymphoma cells taken from recipient line‐6 chickens that had received thymus grafts from line‐7 birds of the opposite sex showed that, in the majority of cases, the lymphomas consisted of cells of donor origin. It is concluded that the susceptibility of line‐7 chickens is largely attributable to the greater susceptibility of their T‐lymphocytes to infection and transformation by Marek's disease virus, and that this susceptibility can be transferred to genetically resistant line‐6 birds by adoptive transfer of the cells in the form of thymus fragments.
Monoclonal antibodies to two mouse bladder carcinoma antigens
Authors: Hellström Ingegerd , Rollins Nicola , Settle Scott , Chapman Philip , Chapman Warren H. , Hellström Karl Erik 
Published: February 2007

AbstractCarcinomas of the urinary bladder of mice were induced by 3‐methyl‐cholanthrene or FANFT [(4‐5‐nitro‐2‐furyl)‐2‐thioazolyl formamide]. On transplantation in vivo, tumor lines consisting of well‐differentiated transitional‐cell carcinomas were established. Some tumors were also explanted in vitro. A rat was immunized with a pool of carcinomas and normal bladder tissue and its spleen cells were hybridized with NS‐I mouse myeloma cells. Supernatants of hybrid cells (“hybridomas;”) were screened for antibody binding to antigens present in bladder carcinomas but not in normal syngeneic urinary bladder, with cell extracts as targets. Hybridomas that appeared to have the required specificity were cloned, tested further against transitional‐cell bladder carcinomas, an anaplasic bladder tumor, rhabdomyosarcomas, a mammary carcinoma, myelomas and lymphomas, and normal adult urinary bladder, kidney, lung, spleen, heart, brain, thymus, and whole embryo. Antibody formed by one hybridoma, 2H5, gave significant binding to membranes from five of seven transitional‐cell carcinomas but not to membranes from any other tissues. A second hybridoma, IE6, formed antibody to an antigen present in bladder carcinomas and normal liver and, in smaller amounts, in several other normal and neoplastic tissues. Fluorescence microscopy established that both antigens were present at the cell surface of transitional‐cell bladder carcinomas. Immunoprecipitation and SDS‐polyacrylamide gel electrophoresis were used to identify the target antigens from 125l‐labelled cell membrane proteins. The antibody formed by 2H5 was found to identify a protein with a molecular weight in the range of 140 kilodaltons, which was detected in transitional‐cell bladder carcinoma and, in small amounts, in normal bladder. The molecular nature of the antigen defined by hybridoma IE6 is not known.
Trophoblastic and mesenchymal structures in rat yolk sac carcinoma
Authors: Sobis H. , Van Hove L. , Vandeputte M. 
Published: February 2007

AbstractThe presence of trophoblastic and mesenchymal structures in primary as well as in transplanted rat yolk sac carcinomas (YSC) is described. These structures were only recorded in rat yolk sac carcinomas derived from displaced yolk sac but never in embryo‐derived yolk sac carcinomas. It is suggested that the endodermal carcinoma cells displaying either a parietal or a visceral yolk sac pattern as well as the mesenchymal and trophoblastic structures may have a common cell ancestor.
High‐frequency generation of new immunoresistant tumor variants during metastasis of a cloned murine tumor line (ESb)
Authors: Bosslet Klaus , Schirrmacher Volker 
Published: February 2007

AbstractA metastatic variant of a chemically induced lymphoma (ESb) from a DBA/2 mouse was found to activate in syngeneic hosts specific anti‐tumor cytolytic T lymphocytes (CTL) which recognized on the tumor a distinct tumor‐associated antigen. Upon metastasis of a cloned ESB tumor line from an s.c. site to the spleen, the tumor cells which were originally sensitive to lysis by anti‐ESb CTL became specifically immunoresistant. The development of immunoresistant variants after tumor‐cell transplantation followed a defined kinetic and organ pattern: they were first detected in the spleen, then also in the liver and in the late stage of tumor progression they were the predominant tumor type in all involved organs. No immunoresistant tumor variants were generated in immunoincompetent animals such as nude (nu/nu) mice. Immunoresistant variants also developed when immunosensitive ESb clones were inoculated into animals specifically preimmunized against ESb. In fact, these variants were the only type of cells eventually growing out from such animals causing death from metastasis in spite of the specific immune status of the host. The change of tumor antigen expression described here differs from antibodyinduced antigenic modulation in that it is genetically transmitted and stable in tissue culture. The immunoresistant tumor variants which did not preexist in the starting, twice‐cloned cell population represent a new type of immune escape variant.
Regulation of rat alpha‐fetoprotein production by methionine during ethionine‐hepatocarcinogenesis
Authors: Miyazaki Mashiro , Watanabe Akiharu 
Published: February 2007

AbstractThe levels of serum alpha‐fetoprotein (AFP) in rats were determined during hepatocarcinogenesis with ethionine, and the effects of methionine administration on serum AFP elevation in these animals were studied with the aim of investigating regulatory mechanisms of AFP production during carcinogenesis. Elevation of serum AFP was observed 6 weeks following the start of feeding a diet containing 0.25% ethionine and again at the 22nd week of feeding, when a well‐differentiated hepatoma had already developed. These biphasic elevations of serum AFP concentrations in rats fed a 0.25% ethionine‐containing diet decreased abruptly and significantly following a change to the basal diet either supplemented with or without 0.7% methionine. The possibility that regulation of AFP production in these rats may correlate with methionine metabolisms is discussed on the basis of the experimental data obtained.
Cell locomotion, a contributing factor in spread of the v2 rabbit carcinoma
Authors: Haemmerli Gisela , Arnold Beatrice , Sträuli Peter 
Published: February 2007

AbstractIn histological sections of s.c. transplanted V2 rabbit carcinoma, single tumor cells and small tumor cell groups were found at some distance from the main tumor mass. This led to the question of whether locomotion could represent a contributing factor in the invasiveness of the V2 carcinoma. The behavior of V2 cells was therefore recorded under experimental conditions of increasing complexity: on glass, on the surface of a normal explanted rabbit mesentery, and on and within mesenteries of rabbits which had received intraperitoneal implants of V2 carcinoma. Time lapse cinematography showed the locomotory activity of V2 cells to be unaffected by the different substrates. In all instances the carcinoma cells migrated singly, on the two plane substrates also in small groups, under production of large leading lamellae. Intraperitoneally implanted V2 cells, in addition to their migration on the surface of the mesentery, penetrated into the interior with continuation of their characteristic translocative motility. Although cell locomotion could be established as a mechanism in the invasiveness of the V2 carcinoma, we do not consider it to be the only relevant factor. Tumor cell proliferation and destructive effects of proteinases appear to be other mechanisms contributing to the functional complex of local spread.