bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reduced levels of fibronectin in ataxia‐telangiectasia lymphoblastoid cells
Authors: Lavin Martin F. , Seymour G. J. 
Published: February 2007

AbstractIn this study Epstein‐Barr virus‐transformed lymphoblastoid cells were shown to contain fibronectin. A marked difference in the number of fibronectin‐positive cells was observed in control and ataxia‐telangiectasia lymphoblastoid cells. Three control cell lines varied between 60% and 80% in the number of cells containing fibronectin. Only a small percentage of ataxia‐telangiectasia cells (1–5%) had fibronectin present. Control and ataxia‐telangiectasia fibroblasts had similar amounts and distributions of fibronectin. An asymmetric distribution of fibronectin was evident in many control and ataxia‐telangiectasia lymphoblastoid cells. The increased frequency of fibronectin‐containing cells in the control populations cannot be accounted for by different growth rates or variation in the various phases of the cell cycle in the two cell types.
Identification of a surface antigen, common to murine lung and lewis lung carcinoma, by monoclonal antibody
Authors: Hadas Eran , Hurwitz Esther , Eshhar Zelig 
Published: February 2007

AbstractLewis lung carcinoma (3LL) is a spontaneous murine lung carcinoma which preferentially metastasizes into the lung. Monoclonal antibodies (MAb) against 3LL cells were prepared by fusing spleen cells from rats immunized with 3LL and the P3‐NSI/I‐Ag4 (NSI) plasmacytoma. Two hybridomas were selected which secreted antibodies capable of preferential binding to 3LL cells and not to other malignant cells. Immunohistochemical staining of sections prepared from various mouse organs with one of the MAbs (22.2), revealed exclusive staining of the lung tissue. The data suggest that a lung‐specific, 3 LL‐associated antigen, is detected by the 22.2 MAb on 3LL cells. The 22.2 antigen is a surface molecule, and is stable following trypsin treatment and fixation by glutaraldehyde or picric acid. Cells that were prepared from a subcutaneous tumor or from lung metastases express high amounts of 22.2 antigen compared to cells of the culture 3LL line (3LLC). Upon reinoculation of 3LLC cells into mice there was a gradual increase in 22.2 antigen expression. It was possible to select from the heterogeneous 3LLC cell population several clones which express high amounts of antigen. These clones differed also in their metastatic patterns. However, the metastatic capacity of these clones did not correlate with expression of the 22.2 antigen. Thus, it appears that expression of the 22.2 antigen is not a necessary condition for formation of lung metastases by 3LL.
Phenotypes associated with tumor rejection mediated by cyclophosphamide and syngeneic tumor‐sensitized t lymphocytes: Potential mechanisms of action
Authors: Evans Robert 
Published: February 2007

AbstractThe phenotypes of the affector and effector cell populations involved during the induction of permanent tumor regression by combined therapy using cyclophosphamide (CY) and immune spleen cells were identified. Permanent tumor regression was dependent on the presence of Thy‐1+ Lyt‐2+ lymphocytes in the immune spleen cell population that was injected i.v. 2‐4 h after an intraperitoneal injection of CY (240 mg/kg) into C57BL/6J mice bearing 1.0‐1.5 g. MCA/76‐9 or MCA/76‐64 sarcomas. Histological evaluation after the combined treatment indicated an intense influx of putative lymphocytes 6‐10 days after the combined treatment, over and above the inflammatory response involving macrophages and neutrophils induced by CY treatment alone. These infiltrating cells were shown to be T lymphocytes, most of them having the Lyt‐1 and Lyt‐2 antigens on their cell membrane. Isolated MCA/76‐9 or 76‐64 tumor‐associated cells (TAC), lymphocytes (TAL) and macrophages (TAM) inhibited MCA/76‐9 or 76‐64 tumor growth respectively in a Winn test in an immunologically specific manner, having no effect on the growth of the B6 sarcoma cells, MCA/76‐45 and 77‐23. The tumor‐free mice from the Winn test were not resistant to a subsequent challenge inoculum of either MCA/76‐9 or 76‐64 cells. Isolated TAC were usually non‐specifically cytotoxic in vitro, while TAL and TAM showed some degree of specificity. The overall data indicated that the ultimate rejection of those tumor cells remaining after the direct anti‐tumor action of CY had been dissipated was probably mediated by the combined action of TAL and TAM.
Further characterization of marek's disease virus‐infected lymphocytes. II. In vitro infection
Authors: Calnek B. W. , Schat K. A. , Ross L. J. N. , Chen C‐L. H. 
Published: February 2007

AbstractLymphocyte cultures from chicken spleens had been shown to be susceptible to in vitro infection by Marek's disease virus (MDV)4 in an earlier report from this laboratory. In that study, virus infection was evidenced by virus isolation and detection of viral internal antigen (VIA) 2 days post inoculation (DPI), and serial passage was accomplished by adding fresh spleen cells at 2‐day intervals. The susceptible cells were identified as bursa‐derived lymphocytes (B cells). Using a dual fluorescence technique to identify surface markers for B cells, thymus‐derived lymphocytes (T cells) or la antigen on VIA‐positive cells, we have now shown that a small proportion (generally less than 10%) of VIA‐positive cells observed 2 DPI are T cells, and that a low level of infection can be maintained by serial passage of MDV in cultures totally free of B cells. Most infected T cells in this study had Ia antigen. As the incubation period for infected cultures was extended from 2 to 4 or 5 days, the average number of viable cells decreased but the percentage of viable cells infected with MDV (VIA‐positive) increased. Also, both the proportion and the actual number of infected T cells increased, significantly more so in cultures from genetically susceptible P‐2 donors than from resistant N‐2 donors. Spleen‐cell cultures from resistant Line 6 chickens were markedly less susceptible than those from susceptible Line 7 chickens to in vitro MDV infection, as assessed by numbers of VIA‐positive cells at 5 DPI.
The long‐term prognostic significance of the thymidine labelling index in breast cancer
Authors: Tubiana M. , Pejovic M. H. , Chavaudra N. , Contesso G. , Malaise E. P. 
Published: February 2007

AbstractA prospective study of the prognostic significance of the labelling index (LI) was undertaken in 1972. The LI of the primary tumor was measured consecutively on 128 patients with mammary carcinoma at the time of initial treatment, followingin vitroincubation of specimens with tritiated thymidine. The follow‐up for all patients has now extended over 10 years. Relapse‐free survival and total survival are significantly higher in patients with a low LI. A multivariate analysis of the prognostic factors, carried out with Cox's model, showed that Li is the most predictive indicator with respect to survival. The size of the tumor is the second most predictive indicator, while histological grading and the number of involved lymph nodes are less predictive. These results strongly suggest that proliferative activity as assessed by LI is directly related to metastatic dissemination probability, independent of other prognostic factors.
Chemosensitivity of human melanoma xenografts in immunocompetent mice and its histological evaluation
Authors: Dumont P. , Esch E. P. Vander , Jabri M. , Lejeune F. , Atassi G. 
Published: February 2007

AbstractIn the subrenal capsule assay, the immuno‐competent mice used have a host immune response to the graft which may introduce a bias in the determination of tumour size. A study was therefore conducted to verify the quality of the correlation that could exist between “macroscopical” and “microscopical” evaluation. A histological study of 12 different tumours treated with cis‐Pt, L‐PAM, DTIC, vindesine, BCNU or TGU demonstrated that a cellular host immune response was observed in 11 out of the 12 control groups and was uneven in the treated groups. The “microscopical” and “macroscopical” evaluations of tumour‐take were 100 and 95% respectively. Although there was a fair correlation between the “microscopic” and “macroscopic” parameters, tumour variations in absence of host reaction ‐ which reflect pure chemosensitivity of the treated tissue ‐ could be measured in 50% of the cases. It was possible to determine abase‐line for rejection of the test results when the control group showed a decrease in mean tumour size exceeding 20% of its initial size on day 0. If the decrease is less than 20%, then the histological evaluation appears to be of considerable additional value.
Distinction between burkitt lymphoma subgroups by monoclonal antibodies: Relationships between antigen expression and type of chromosomal translocation
Authors: Ehlin‐Henriksson Barbro , Klein George 
Published: February 2007

AbstractTwenty‐six lines derived from 22 Burkitt lymphoma patients were examined for cytoplasmic vs. surface immunoglobulin and the expression of the monoclonal‐antibody‐detected BLA, CALLA and LB‐I antigens. Six of the lines carried the variant translocations 8;2 or 8;22 (three each), 17 lines had the typical 8;14 translocation, I was translocation‐negative (BJAB) and 2 were not examined cytogenetically. Depending on their immunoglobulin and surface marker expression, the BL lines could be subdivided into several subgroups. There was a strong inverse correlation between the expression of the CALLA and the LB‐I marker. All BLA‐lines were CALLA‐, whereas the CALLA+ lines could be either BLA‐ or BLA+. All six variant translocations belonged to the CALLA‐BLA‐LB‐I + category. Only one set of three lines, derived from the patient with the 8;14 translocation, belonged to the same subgroup. This suggests that the typical vs. the variant translocation freezes the BL cell at a different stage of differentiation. The variant translocation‐carrying subtypes represent probably a somewhat more advanced stage of differentiation.
Binding of five monoclonal anti‐CEA antibodies with different epitope specifities to various carcinoma tissues
Authors: Wagener Christoph , Petzold Petra , Köhler Wolfgang , Totović Vladimir 
Published: February 2007

AbstractFive monoclonal antibodies that recognize different epitopes on carcinoembryonic antigen (CEA) were reacted with tissue sections of various carcinoma specimens. The vital, non‐necrotic tissues of those carcinomas of the oesophagus, pancreas, colon and rectum, medullary thyroid, ovary and cervix in which CEA related epitopes were detectable bound all five antibodies to a similar degree. In 3/5 lung carcinomas, 2/10 mammary carcinomas and 1/5 gastric carcinomas, a significantly different binding of the monoclonal antibodies by vital tumour tissue was present as determined by three independent investigators. In necrotic tissue areas, heterogeneity of antibody binding was more common. In a previous investigation, it was shown that normal granulocytes and liver tissue differentially bind the monoclonal anti‐CEA antibodies, indicating the presence of crossreacting antigens. The equivalent binding of the five monoclonal anti‐CEA antibodies to most of the carcinomas tested suggests that this binding is due to the presence of complete CEA molecules and not only of crossreacting antigens.
Simultaneous hyperthermia at 43°c reduces radiation‐induced malignant transformation frequencies in golden hamster embryo cells
Authors: Watanabe Masami , Nikaido Osamu , Sugahara Tsutomu 
Published: February 2007

AbstractStudies were done to determine whether hyperthermia alone, or in simultaneous combination with X‐rays, can induce malignant transformation in golden hamster embryo cells. Hyperthermia alone did not induce transformation. In fact, it reduced the frequency of the malignant transformation induced by X‐rays. DNA damage as measured by alkaline elution and protein degradation were both induced by hyperthermia. However, the relationship of such damage to cell death is not yet clear. Our data indicate that hyperthermia either alone or in combination with X‐ray treatment should be a safe method of cancer therapy.
Induction of epstein‐barr virus antigens by tumor promoters for epidermal and nonepidermal tissues
Authors: Takada Kenzo , Hausen Harald Zur 
Published: February 2007

AbstractFifteen established tumor promoters belonging to different chemical groups were tested for their ability to induce Epstein‐Barr virus (EBV)‐specific early antigens (EA) in EBV‐genome‐positive nonproducer Raji cells. Saccharin (a promoter in urinary bladder carcinogenesis), DDT (a promoter in liver carcinogenesis), anthralin and iodoacetic acid (promoters in skin carcinogenesis) gave a significant induction with a maximum of induced cells of 20% (8 mg/ml), 0.8% (20 μg/ml). 0.8% (100 ng/ml) and 0.7% (0.4 μg/ml), respectively. In addition, after combined application with a noninducing dose (0.2 ng/ml) of 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA), seven additional tumor promoters induced 0.3‐2.1% EA‐positive cells two days after treatment. The results indicate that in addition to mouse skin tumor promoters such as diterpene esters, several compounds reported to possess tumor‐promoting activity in other types of tissue induce EBV. The data suggest that EBV induction is an effect commonly exerted by this group of compounds which should be very useful in screening for environmental tumor promoters.
The importance of 5‐HT for tumor cell lodgement in the liver
Authors: Skolnik G. , Bagge U. , Dahlström A. , Ahlman H. 
Published: February 2007

AbstractArrest and lodgement of circulating tumor cells in the microvasculature is a prerequisite for metastasis formation. Aggregation of activated platelets and subsequent release of bioactive substances seem to influence the lodgement process. Since thrombocytopenia has been shown to reduce lodgement and since 5‐HT is one of the compounds released from activated platelets, the present investigation was directed toward the influence of this amine on tumor cell lodgement in the liver after intraportal injection of fibrosarcoma cells. Lodgement was quantitated by an isotope technique with simultaneous measurements of 5‐HT levels by a LCEC technique in rat liver biopsies from areas with lodged tumor cells as observed with vital fluorescence microscopy. To test the importance of 5‐HT released from platelets, thrombocytopenia was induced with anti‐platelet serum in one experimental group, while animals in another group were treated with ketanserin (a selective 5‐HT2 receptor blocking agent). Animals given tumor cells alone showed a two‐fold increase in 5‐HT levels compared with animals injected with saline, indicating a relation between 5‐HT release and tumor cell lodgement. In thrombocytopenic animals lodgement was reduced to 53% (5‐HT levels reduced to 50%) of tumor‐cell‐injected controls. Ketanserin treatment reduced tumor cell lodgement to 72% (5‐HT levels to 63%). The results indicate that 5‐HT is one of the sub‐stances released from activated platelets and that 5‐HT is involved in tumor cell lodgement.
Variant generation and selection: An In vitro model of tumor progression
Authors: Chow Donna A. 
Published: February 2007

AbstractEvidence for a new in vitro model of tumor progression was sought on the basis of the variant generation and selection hypothesis. The stability of a cloned murine tumor was examined during growth in standard tissue culture or in media containing the tumor promoter 12–0‐tetradecanoylphorbol‐13‐acetate (TPA). Analysis of subclones from the appropriate tumor populations revealed that growth of the L5178Y‐F9 clone in 100 ng/ml TPA and 0.1% dimethyl sulphoxide (DMSO) for 2 days yielded a tumor which exhibited increased cellular heterogeneity for susceptibility to both syngeneic and allogeneic natural antibodies (NAb). Subsequent exposure of TPA‐ and DMSO‐treated cells to two cycles of syngeneic NAb‐mediated cytolysis resulted in tumor populations which expressed a reduced sensitivity to syngeneic NAb. Thus the elements of tumor variant generation and selection were demonstrated by means of this approach, and repeated cycles of the TPA treatment and NAb cytolysis produced tumor cells with a reduced susceptibility not only to NAb in vitro but also to anti‐tumor natural resistance (NR) measured in a tumor elimination assay in vivo. These observations extend the support for the notion that tumor progression can proceed through variant generation and selection. Furthermore, the association of tumor variant generation with exposure to the combination of TPA and DMSO, both non‐mutagens, offers a model for studying non‐mutagenic mechanisms of tumor development.
Coffee drinking and the risk of epithelial ovarian cancer
Authors: Vecchia Carlo La , Franceschi Silvia , Decarli Adriano , Gentile Antonella , Liati Paola , Regallo Michela , Tognoni Gianni 
Published: February 2007

AbstractThe relation between ovarian cancer and coffee drinking habits was evaluated in a case‐control study of 247 histologically confirmed epithelial ovarian cancers and 494 agematched controls, admitted to hospital for acute conditions apparently unrelated to coffee consumption. Compared to rates for women who had never drunk coffee, the crude relative risk estimates for those who drank less than two, two or three, and four or more cups per day were 1.3, 1.5 and 1.4 respectively; however, when allowance was made for smoking habits, these risk estimates became 1.3, 1.7 and 1.8 respectively, and a significant linear trend of increasing risk with more elevated coffee consumption was evident. These results were not explained by various other potential confounding factors, including the major risk factors for ovarian cancer, but we had no information on dietary variables. The relative risk, however, did not increase with increasing duration of use. The findings of this study give apparent support in favour of the hypothesis that coffee consumption, or related dietary variables, may be associated with the risk of epithelial ovarian cancer. Further studies in different settings, however, are required in order to establish whether this association is real, and if so, whether it is causal.
Tissue type plasminogen activator, but not urokinase, exerts transformation‐enhancing activity
Authors: de Petro G. , Vartio T. , Salonen E. M. , Vaheri A. , Barlati S. 
Published: February 2007

AbstractPrevious studies have established that plasma cryoprecipitates of tumor patients, culture media of transformed cells and defined proteolytic fragments of fibronectin enhance the morphological cell transformation (TEF activity) in cultures of chicken embryo fibroblasts infected with temperature‐sensitive mutants of Rous sarcoma virus. We now report that purified human tissue type plasminogen activator (t‐PA), but not urokinase (u‐PA), has a similar TEF activity, at doses as low as 2 ng/ml (30 pM). Specific antibodies effectively neutralized the activity. No significant contamination (≤1%) between the preparations of t‐PA and fibronectin (FN) or its fragments (FNdp) was detected. The results suggest that t‐PA may have a direct role in the process of morphological cell transformation in vitro.
Calcium concentration defines two stages in transformation of lymphocytes by epstein‐barr virus
Authors: Moss D. J. , Burrows S. R. , Parsons P. G. 
Published: February 2007

AbstractLymphocytes from Epstein‐Barr virus (EBV) seronegative donors were either stimulated with Protein A or infected with EBV and cultured in growth medium containing a range of calcium levels (700 μM to <2 μM available calcium). Three calcium end‐points for the proliferation of B lymphocytes were defined: 18 M for mitogenicallystimulated B cells; 8 μM for a pre‐12 h event in EBV transformation and <2 μM for a post‐12 h event in EBV transformation resembling the end‐point for the emergent lymphoblastoid cell line. EBV‐infected lymphocytes cultured in calcium‐depleted medium expressed the EB virus nuclear antigen and proliferated after addition of calcium chloride. The present study should be useful both in defining the sequence of events in EBV transformation and in studying properties specific to the transformed phenotype.
Primary but not metastatic human melanomas expressing dr antigens stimulate autologous lymphocytes
Authors: Fossati Giuseppe , Taramelli Donatella , Balsari Andrea , Bogdanovich Gordana , Andreola Salvatore , Parmiani Giorgio 
Published: February 2007

AbstractLymphocytes from melanoma patients were stimulated in mixed culture with autologous tumor cells (MLTC) in order to evaluate lymphocyte proliferation and subsequent cytotoxicity on autologous melanoma cells. It was found that melanoma cells from lymph node metastases were unable to induce autologous tumor‐cytotoxic cells in 21 cases examined, in 15 of which MLTC also failed to induce lymphocyte proliferation. Patients' lymphocytes, however, were significantly stimulated by allogeneic irradiated lymphocytes and by interleukin 2. To investigate whether the lack of autologous stimulation was restricted to metastatic cells, the immune response of patients with only primary lesions of malignant melanoma was evaluated. It was found that primary melanoma cells were able to induce proliferation in 7 out of 9 (77%) patients, whereas positive cytotoxicity was obtained in 2 out of 4 patients tested. In order to see whether the presence of DR molecules was important for the stimulatory activity, melanoma cells were examined for the expression of DR antigens by indirect immunofluorescence with monoclonal antibodies. Positive autologous MLTC was found in all of six DR+ primary melanomas, whereas the two DR‐tumors were unable to stimulate autologous lymphocytes. An anti‐DR but not an anti‐DC monoclonal antibody was able to block the proliferation of lymphocytes induced by an autologous primary melanoma. Neither MLTC nor cell‐mediated killing was obtained with either DR+ or DR‐metastatic melanoma. In 60% of the cases tested, however, DR+ metastatic melanoma cells were able to stimulate allogeneic lymphocytes of normal individuals. Increased expression of DR antigens was induced by in vitro treatment with human gamma‐interferon in metastatic tumor cells; this caused an increase in the proliferation of allogeneic but not autologous lymphocytes. These findings indicate that primary but not metastatic DR+ melanoma cells are able to activate the proliferation and cytotoxicity of autologous peripheral blood lymphocytes, suggesting a potential role of DR antigens in regulating tumor‐host relationships in melanoma patients.
Establishment of an etoposide‐resistant human epithelial tumour cell line In vitro: Characterization of patterns of cross‐resistance and drug sensitivities
Authors: Hill Bridget T. , Bellamy Angela S. 
Published: February 2007

AbstractA human tumour cell line resistant to etoposide (VP16–213) has been produced by fractionated X‐irradiation exposure in vitro. Characterization of this line, derived from an epithelioid carcinoma of the tongue, revealed no significant differences in terms of several cytological and kinetic parameters compared with the parent line. Patterns of cross‐resistance and drug sensitivities were determined by colony formation in soft agar after 24 h drug exposures. Three patterns of response were observed with the VP16–213‐resistant cells showing: marked cross‐resistance to vincristine and tenopside, collateral sensitivity to 5‐fluorourcil, hydroxyurea and cis‐platinum, and comparable responses to the parent line for adriamycin, bleomycin, dibromodulcitol and methotrexate. This is the first demonstration that specific drug resistance can be induced by prior exposure to X‐irradiation in vitro. This cell line appears to show a unique lack of cross‐resistance between adriamycin and vincristine or etoposide. Preliminary investigations into possible mechanisms of etoposide resistance demonstrated similar DNA sedimentation profiles after etoposide exposure in both tumour cell lines, implying no differential effects of this drug on DNA of resistant cells. These data raise the possibility that the expression and mechanism of resistance may differ, depending on the manner in which drug resistance is induced.