bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of Epstein‐Barr virus‐encoded proteins in nasopharyngeal carcinoma
Authors: Fåhraeus Robin , Fu Hu Li , Ernberg Ingemar , Finke Jurgen , Rowe Martin , Klein George , Falk Kerstin , Nilsson Ethel , Yadav Manmohan , Busson Pierre , Tursz Thomas , Kallin Bengt 
Published: February 2007

AbstractExpression of the Epstein‐Barr virus (EBV) encoded nuclear antigens (EBNA 1 to 6) and membrane‐associated protein (LMP) was investigated by immunoblotting in 83 nasopharyngeal carcinoma (NPC) biopsies and 25 other tumor and normal tissue specimens from the head and neck region. Fifty‐eight of the 83 NPC biopsies were large enough to yield parallel data on virus DNA and viral expression. All 16 cases of clinically diagnosed and histologically confirmed NPCs from North Africa contained EBV DNA and expressed EBNA‐1. Of 31 clinically diagnosed NPCs from China, 29 contained EBV DNA and 25 of these expressed EBNA‐1. One control tissue biopsy from the oropharynx of NPC patients contained EBV DNA, but none expressed EBNA‐1. The latent membrane protein (LMP) was detected in 22/31 of the Chinese and in 10/16 of the North African NPC biopsies. None of the NPC biopsies or control tissues expressed detectable amounts of EBNA 2 or any of the other 4 nuclear antigens which are invariably expressed in EBV‐transformed B cells. A smaller number of tumors from Malaysia and East Africa exhibited a similar pattern of expression. EBV was rescued from a nude‐mouse‐passaged North African NPC tumor by co‐cultivation of the tumor cells with umbilical cord blood lymphocytes. The tumor expressed EBNA 1 and LMP, but not EBNA 2 or the other 4 EBNAs. The resulting LCLs expressed all 6 nuclear antigens, EBNA 1 to 6 and LMP. Our data suggest that expression of the EBV genome is regulated in a tissue‐specific fashion.
Effect of recombinant human tumor necrosis factor on tumor and spleen in mice
Authors: Knippel E. , Rychly J. , Schulze H. A. , Ringel B. , Krygier‐Stojalowska A. 
Published: February 2007

AbstractThe ability of recombinant human tumor necrosis factor (rH‐TNF‐α) to induce regression of sarcoma 180 in vivo was evaluated. The tumor was cured by TNF in the course of 4 weeks. TNF inhibited proliferation of sarcoma 180 cells in vitro, which suggests a direct effect of TNF on tumor cells in vivo. In parallel to the TNF effect on tumor growth, some cell parameters in spleen were investigated. Activation of splenic macrophages was enhanced in vitro. This result suggests that macrophages may participate in the host defense against the tumor. In the first phase of therapy, TNF did not affect the proliferation of splenocytes but increased the transition of G0 into G1 cells. Furthermore, TNF normalized the tumor‐induced increase of null cells in tumor‐bearing mice. All parameters investigated in spleen reached normal values at the time of tumor regression. Our results suggest that various mechanisms may be involved in TNF‐induced regression of sarcoma 180.
Effects of bilateral and unilateral vagotomy on gastric carcinogenesis induced by N‐methyl‐N′‐nitro‐N‐nitrosoguanidine in wistar rats
Authors: Tatsuta Masaharu , Iishi Hiroyasu , Yamamura Hisako , Baba Miyako , Taniguchi Haruo 
Published: February 2007

AbstractAfter administration of N‐methyl‐N′‐nitro‐N‐nitrosoguanidine for 15 weeks, the effects of bilateral, anterior and posterior vagotomy on the incidence, number and location of gastric adenocarcinomas, gastric acid secretion and cell proliferation of the gastric mucosa were investigated in inbred Wistar rats. Bilateral or anterior vagotomy, but not posterior vagotomy, significantly increased the incidence and number of adenocarcinomas at experimental week 52. In sham‐operated control rats and rats subjected to bilateral vagotomy, there was no significant difference between the incidence or number of gastric tumors in the anterior and posterior walls. After anterior and posterior vagal denervation, however, there were significantly more gastric cancers on the denervated side than on the other. Bilateral and unilateral vagotomy resulted in significantly reduced gastric acid secretion by experimental weeks 25 and 52. Bilateral vagotomy significantly increased the labelling indices of both the fundic and antral mucosa at both times, but did not cause any significant difference between those of the anterior and posterior wall. Anterior or posterior vagotomy resulted in a significant increase in the labelling indices of both the fundic and antral mucosa on the denervated side. These findings indicate that the vagal nerve exerts a trophic action on the gastric mucosa, and that the promoting effect of vagotomy on gastric carcinogenesis may be related to its effect in increasing proliferation of cells in the antral mucosa.
Interferon‐gamma‐induced alterations of monocyte susceptibility to lysis by autologous lymphokine‐activated killer (LAK) cells
Authors: Djeu Julie Y. , Blanchard D. Kay 
Published: February 2007

AbstractInterleukin‐2 (IL‐2)‐activated killer (LAK) cells specifically lyse human monocytes, which may account for some of the toxicity seen during LAK/IL‐2 immunotherapy of cancer patients. In an effort to protect autologous monocytes, we treated monolayer cultures of monocytes with various doses of recombinant human interferon‐gamma (IFN‐gamma) and assessed their sensitivity to LAK‐mediated lysis. IFN‐gamma lessens the sensitivity of monocytes to lysis in a dose‐dependent manner. Treatment of FMEX, an NK‐resistant melanoma tumor cell line, with IFN‐gamma did not affect its susceptibility to LAK lysis. Kinetic studies demonstrated that as little as 2 hr incubation with IFN‐gamma was sufficient for protection to occur, and that monocytes which were treated with IFN‐gamma for 2 hr, washed, and then cultured in medium alone retained their resistance to lysis for at least 4 days. Cold target inhibition studies showed that IFN‐treated and untreated monocytes could effectively compete with each other for binding sites on LAK cells. Finally, binding studies demonstrated that there was no significant difference between the number of conjugates formed using either IFN‐treated or untreated monocytes. This indicates that resistance to lysis induced by IFN treatment affects a post‐binding event and not an initial recognition signal.
Anti‐tumor surveillance of non‐contact‐inhibited transformed cell lines
Authors: Vanderslice W. Eric , Collins John Leslie 
Published: February 2007

AbstractIn order to determine if the correlated expression of transformation and tumorigenicity is affected by the agents used to induce transformants or by the immune status of the host used to test the tumorigenicity of transformants, we derived a series of cloned cell lines from foci of transformed cells induced by treatment of the contact‐inhibited mouse cell line B/C‐N7. ICI with the DNA demethylating agent 5‐azacytidine (5‐AZC) or the DNA demethylating and mutating agent benzo(a)pyrene dihydrodiol epoxide (BPDE). The transformed cell lines were injected into syngeneic nude and normal mice to determine their tumorigenicity. The results of this analysis showed that 93% of the transformants induced by 5‐AZC treatment grew as tumors when injected into nude mice. Of those lines capable of growing as tumors in nude mice, 86% were also tumorigenic when injected into normal mice. In contrast, only 64% of BPDE‐induced transformants grew as tumors in nude mice, and of those, only 44% were also tumorigenic in normal mice. The existence of non‐contact‐inhibited transformants that are tumorigenic only in nude mice indicates that host anti‐tumor immune surveillance mechanisms are operative in normal mice. Further, the difference in both the percentage of transformed cell lines that are tumorigenic and the percentage of tumorigenic transformants that are susceptible to immune surveillance when transformants are induced by BPDE as compared to 5‐AZC indicates that the transforming agent can affect both the correlation between the expression of transformation and tumorigenicity, and the interaction between the immune system and tumorigenic transformants.
Tumor‐selective cytotoxic effects of murine tumor necrosis factor (TNF) and interferon‐gamma (EN‐gamma) in organ culture of B16 melanoma cells and heart tissue
Authors: Mareel Marc , Dragonetti Christian , Tavernier Jan , Fiers Walter 
Published: February 2007

AbstractOrganotypically cultured, confronting pairs of B16B16 cell clusters and fragments of embryonic chick or mouse heart, as used for the study of invasion in vitro, were treated with murine TNF plus IFN‐gamma for 4 and 7 days. This treatment selectively killed the B16B16 cells and left the heart tlssue intact as assayed by histology and by plating confronting pairs and spent medium on tissue culture substrate. Using this organ culture assay, which more closely mimics the situation in vivo, we confirmed the tumor‐selective cytotoxic effects of combined treatment with TNF and IFN‐gamma as observed in separate cultures of malignant and non‐malignant cells on “artificial” substrate.
Carcinoid tumour cells in long‐term culture: Release of serotonin but not of tachykinins on stimulation with adrenoceptor agonists
Authors: Ahlman H. , Åhlund L. , Nilsson O. , Skolnik G. , Theodorsson E. , Dahlström A. 
Published: February 2007

AbstractTumour cells from a lymph‐node metastasis of a midgut carcinoid tumour, Immunoreactive for serotonin and substance P, were isolated and kept in culture for 2 months. The formation of large clusters or islets of tumour cells was paralleled by an increase in immunoreactive tachykinins {neuropeptide K and substance P} in the culture medium. The concentration of tachykinins declined subsequently despite good viability of the cells. Spontaneous release of serotonin into the culture medium was much greater than that of tachykinins, and remained stable throughout the study. These findings indicate different turnover rates and/or different storage sites for the peptides and the amine. In stimulation experiments, a dose‐dependent release of serotonin, but not of tachykinins, was induced by a β‐adrenoceptor aganist (isoprenaline), while stimulation of α‐adrenoceptors (noradrenaline) was not effective In releasing any of the substances. Pretreatment of the cultures with a β‐adrenoceptor antagonist {propranolol} or stimulations after calcium deprivation did not influence the isoprenaline‐induced release of serotonin. These findings may indicate a modification of genuine β‐adrenoceptors during culture.
abl oncogene expression in non‐Hodgkin lymphomas: Correlation to histological differentiation and clinical status
Authors: Greil R. , Gattringer C. , Fasching B. , Cleveland J. , Thaler J. , Radaskiewicz T. , Gastl G. , Huber C. , Rapp U. , Huber H. 
Published: February 2007

AbstractEight reactive lymphatic tissues, 166 cases of non‐Hodgkin lymphomas (NHL) and 11 cases of multiple myeloma were investigated for expression of the c‐abl protein using the polyclonal anti‐abl antibody 4411 and an indirect peroxidase technique. In selected cases the results were compared to those obtained with a second polyclonal and 2 monoclonal anti‐abl antibodies. In 7 cases, Northern blot analysis of abl‐mRNA was performed in parallel. In reactive lymphatic tissues, cells positive for the 4411 antibody were confined to the B‐cell areas, i. e., to the mantle zone and parts of the germinal center. In NHL, a positive staining of the cell membrane was predominantly detectable in lymphomas putatively originating in the germinal center or mantle zone (in particular in centrocytic NHL), independent of their proliferative activity. Clinically, 7 out of 8 abl‐positive cases of chronic lymphocytic leukemia (CLL) had a more aggressive course of disease, whereas “progressive disease” occurred in only 7 out of 19 c‐abl antigen‐negative cases. When the clinical status of 78 patients with NHL and II patients with multiple myeloma was related to c‐abl expression, c‐abl‐positivity was mostly confined to patients in advanced tumor stages [p<0.001 (NHL)].
A TaqI RFLP of the human TGFα gene is significantly associated with cutaneous malignant melanoma
Authors: Hayward Nicholas , Nancarrow Derek , Ellem Kay , Parsons Peter , Kidson Chev 
Published: February 2007

AbstractA Taql restriction fragment length polymorphism (RFLP) of the human transforming growth factor alpha (hTGFα) locus was analyzed in DNA from 63 normal individuals, 34 malignant melanoma (MM) cell lines, and 18 melanoma biopsy specimens. The frequency of a 2.7‐kb allele (0.18) in MM cell lines was significantly higher P < 0.01) than in lymphoblastoid cell lines (LCLs) derived from unaffected controls (0.05). The frequency (0.14) in MM biopsies was similar to that in MM cell lines although, owing to the small numbers investigated, it was not significantly higher than in controls. In the case of 5 MM patients who were constitutionally heterozygous for alleles at the TGFα locus, no apparent losses of heterozygosity were observed in the corresponding tumour DNA. Thus, the constitutional presence of the 2.7‐kb allele may be a risk factor for melanoma.
Establishment and characterization of three transplantable EBV‐containing nasopharyngeal carcinomas
Authors: Busson P. , Ganem G. , Flores P. , Mugneret F. , Clausse B. , Caillou B. , Braham K. , Wakasugi H. , Lipinski M. , Tursz T. 
Published: February 2007

AbstractThree transplantable nasopharyngeal carcinoma (NPC) tumors, designated C15, C17 and C18, have been obtained and characterized. C15, derived from a primary NPC tumor, has been propagated in nude mice for 30 passages. C17 and C18, derived from metastatic NPC tissue, have been passaged 10 times. Desmosomes, present in every case, provided confirmation of the epithelial origin of all 3 tumors. The Epstein‐Barr virus (EBV) genome is contained in C15, C18 and C17 tumor cells with 30, 12 and 3 copies, respectively. The Epstein‐ Barr virus nuclear antigen (EBNA) was stained by the classical anti‐complement immunofluorescence (ACIF) technique. Fluorescence intensity was strong in C15, moderate in C18, and hardly detectable in C17 cells. No expression of the EA and VCA antigens was detected. Flow cytometry analysis performed on monocellular suspensions showed the absence of detectable CR2 molecules (the EBV receptor on B lymphocytes) in all 3 tumors, and the constitutive expression of HLA class‐II antigens in C15 and C17 cells. IL‐1 activity was demonstrated in the supernatant of C15 and C17 cells cultivated in vitro for 3 days. These data confirm that the constitutive synthesis of MHC class‐II molecules and the release of IL‐1‐like activities are frequent features of NPC cells. These characteristics could be of importance in relation with the T‐cell infiltrate found in NPC primary tumors.
Development and characterization of a syngeneic monoclonal antibody to a rat mammary tumor metastasis‐associated mucin like cell‐surface antigen (gp580)
Authors: North Susan M. , Steck Peter A. , Spohn William H. , Nicolson Garth L. 
Published: February 2007

AbstractA rat hybridoma producing IgM monoclonal antibody (MAb) GP21:56 was generated with specificity for a high‐molecularweight, mucin‐like glycoprotein (gp580) present on highly metastatic 13762NF rat mammary adenocarcinoma cells. The hybridoma was made by fusing rat Y3 Ag1.2.3 myeloma cells with spleen cells from a rat immunized i. d. with purified gp580. The gp580 appeared to be of low immunogenicity in syngeneic F344 rats because a total of 27 fusions were required to produce one hybridoma with specificity for this glycoprotein. Immunoblotting of purified gp580 after electrophoresis in 1% agarose and antibody‐binding assays using purified gp580 linked to microtiter plates confirmed that MAb GP21:56 bound specifically to gp580. Other MAbs made against breast mucins were negative for gp580 reactivity. Enzymelinked immunoabsorbent assays (ELISA) and radiolabelled antibody binding assays demonstrated that MAb GP21:56 bound to 13762NF adenocarcinoma cell lines and clones in relation to their spontaneous metastatic potentials; significantly more MAb GP21:56 bound to highly metastatic MTLn3 cells than to low metastatic MTC cells, and MAb GP21:56 showed little reactivity towards the majority of other cell lines tested, whether of rodent or of human origin. Kinetic binding studies indicated that MAb GP21:56 does not have a high affinity for gp580 but, once bound, it shows high avidity for this sialogalactoprotein. Localization studies using frozen tissue sections of 13762NF tumors indicated that MAb GP21:56 reacts with tumor cells grown in vivo in an analogous manner to in vitro cultured cells. Using immunoperoxidase techniques, less than 50% of the highly metastatic MTLn3 tumor cells were stained, whereas approximately 20% of the intermediate metastatic MTF7 and MTLn2 cells and < 10% of low metastatic MTC and MTPa cells were stained with MAb GP21:56. The cell‐to‐cell reactivity was heterogeneous and mainly associated with the tumor‐cell surface and extracellular matrix.
Differentiation of the human pancreatic adenocarcinoma cell line (Capan‐1) in culture and co‐culture with fibroblasts dome formation
Authors: Levrat J. H. , Palevody C. , Daumas M. , Ratovo G. , Hollande E. 
Published: February 2007

AbstractThis study was designed to investigate differentiation of human pancreatic duct carcinoma cells (Capan‐I) in vitro. Observations on live cells, and electron microscopic examination, together with enzymological and immunocytochemical methods, have demonstrated that these cells differentiate spontaneously at an early stage. The cells are seen to be joined by apical junctions. High ATPase activity can be detected in the basolateral membranes, and the cells secrete a gastric type mucin (MI) bearing acidic groups. During differentiation in culture, they form domes which are thought to be the morphological expression of trans‐epithelial transport of water and electrolytes. This particular structure is transitory, since after 6 days in culture all the cells lose their adhesivity, and form into floating cords. Co‐culture of Capan‐I cells and human, nude mice or chick embryo fibroblasts leads to a higher degree of differentiation of epithelial cells, reflected by the earlier appearance of numerous domes. In addition, the anchorage of Capan‐I cells to fibroblasts prevents retraction of the monolayer, and enables the domes to be maintained in the cultures for more than one month. These findings suggest that Capan‐I cells are able to carry out trans‐epithelial movement of water and electrolytes. It is suggested that excretion of ions (bicarbonate and/or chloride) is preserved after transformation of pancreatic duct cells. Mucins (MI) and the recently described VIP receptor sites are also thought to play a part in these exchange processes.
Proliferative and cytolytic potentials of purified human tumor‐infiltrating t lymphocytes. Impaired response to mitogen‐driven stimulation despite T‐cell receptor expression
Authors: Miescher S. , Stoeck M. , Qiao L. , Barras C. , Barrelet L. , von Fliedner V. 
Published: February 2007

AbstractUsing limiting dilution analysis (LDA) we have previously shown that in most instances, the frequency (F) of proliferative T lymphocyte precursors (PTL‐P) was strikingly reduced in tumor‐infiltrating lymphocytes (TIL). In this study involving 19 cases, we show that the impaired clonogenic potential of CD2+ TILs is primarily caused by an intrinsic defect rather than to suppressor T cells or to a direct effect of the tumor cells usually present in the culture system. This was demonstrated by experiments in which the F of PTL‐Ps was quantitated both in highly purified CD2+ TILs (using a cell‐sorter) and in non‐purified TIL suspensions (still containing tumor cells), which originated from the same biopsy specimen. The F of PTL‐Ps was virtually identical in either sorted or non‐sorted suspensions and the data from LDA were always consistent with the single‐hit Poisson model, indicating that no suppressor cells interfered with growth of CD2+ TIL. Stimulation of sorted CD2+ TIL in low‐density cultures by either phytohemagglutinin or anti‐CD3‐monoclonal antibody (MAb) indicated that the antigen‐dependent activation pathway was impaired, although structurally intact T‐cell receptor (TCR) complexes were apparently expressed, as assessed by immunofluorescence. The depressed proliferative response of CD2+ TIL could not be reversed in vitro when phorbol‐esters were used in combination with ionomycin, which bypass the TCR. Nevertheless, 180 clones obtained from 8 cases were analyzed for their cytolytic activity. The majority mediated specific lytic activity (against unknown antigens), as assessed by lectindependent cell cytotoxicity, whereas only 6% of them manifested lymphokine‐activated killing on appropriate targets.
Ovarian cancer incidence and mortality in denmark, 1943‐1982
Authors: Ewertz Marianne , Kjaer Susanne Krüger 
Published: February 2007

AbstractTrends in ovarian cancer incidence and mortality were examined using data from the Danish Cancer Registry and national mortality statistics respectively. The study population comprised 17,956 incident cases diagnosed between 1943 and 1982 and 11,904 deaths between 1953 and 1982 due to cancer in the ovaries, Fallopian tube, and broad ligament. A significant 50% increase in incidence occurred from 1943 to 1972, whereafter a slight decrease was observed. This rise could be ascribed entirely to an increasing incidence among women born between 1863 and 1898. No change was seen in women born after 1900. Analysis of mortality confirmed the increasing ovarian cancer risk among women born during the last century, but indicated that the risk of dying from ovarian cancer decreased with time among women born after 1900. The observed trends were compatible with cohort‐specific changes in fertility in Danish women born between 1890 and 1934. The effect of age on ovarian cancer incidence, overall and by histologic type, agreed well with previous findings.
Purification and characterization of the epstein‐barr virus nuclear antigen 2 using monoclonal antipeptide antibodies
Authors: Dillner Joakim , Wendel‐Hansen Vidar , Kjellström Gunilla , Kallin Bengt , Rosén Anders 
Published: February 2007

AbstractThe Epstein‐Barr virus (EBV) nuclear antigen 2 (EBNA‐2) is the only one of the EBNA proteins to have been implicated as an EBV‐encoded transforming protein. More detailed studies of this protein have been hampered by the lack of EBNA‐2‐specific monoclonal antibodies (MAbs) and of purified protein. To overcome these problems, we isolated 5 hybridomas producing MAbs reactive with an 18 residue synthetic peptide corresponding to the carboxyterminus of EBNA‐2. Four of the 5 MAbs were specifically reactive with EBNA‐2 in its denatured form on immunoblots. The 5th antibody (IISE) was reactive with the native form of EBNA‐2. By using a one‐step immunoaffinity purification method with II5E cross‐linked to protein‐A‐Sepharose, we purified EBNA‐2 to homogeneity, i. e., more than 1,200‐fold, from Burkitt lymphoma cell extracts. A major 32‐kDa associated protein and a less abundant 17‐kDa protein were co‐purified with EBNA‐2. Immunoprecipitation with 115E from 35S‐methionine‐labelled cell extracts showed that the 32‐kDa protein co‐precipitated with EBNA‐2 from EBV‐positive cells, but was not detectable in immunoprecipitates of EBV‐negative cells. When the immunoprecipitates or the purified proteins were immunoblotted with EBV‐immune sera, only EBNA‐2 was reactive, indicating that the associated proteins are of cellular origin. Immunoprecipitation of cells labelled with 32P‐orthophosphate showed that EBNA‐2, but not the associated proteins, is a phosphoprotein. The expression level of EBNA‐2 varied between different EBV‐carrying cell lines, as measured by a 2‐site ELISA based on antibody II5E. In indirect immunofluorescence, the II5E MAb gave an EBNA‐2‐specific characteristic granular staining pattern. These characteristics of EBNA‐2 resemble those of other viral transforming proteins.