bluuebunny/crossref_metadata_2025 huggingface dataset:
Aflatoxin detected in human breast milk by immunoassay
Authors: Wild Christopher P. , Pionneau Florence A. , Montesano Ruggero , Mutiro Crispen F. , Chetsanga Christopher J.
Published: February 2007

Several epidemiological studies have shown a positive association between dietary exposure to aflatoxin (AF) and an increased incidence of primary hepatocellular carcinoma (PHC). One area in which little information is available is the exposure of newborn children to AF in human breast milk. We report the development, validation and application of an enzcyme‐linked immunosorbent assay (ELISA) to the detection of AF in human breast milk. The assay allows the quantitation of 2 pg AFM, per ml of milk using less than 10 ml of sample. A good correlation was observed between ELISA and an hplcfluorescence technique using naturally contaminated milk at levels up to 40 pg AF per ml. Of 54 samples collected from women in rural villages in Zimbabwe, 6 were found to be positive (11 %) in ELISA with levels up to 50 pg AF per ml. No positive samples were detected out of 42 milk samples obtained from women in France. This sensitive and rapid methodology will be useful in examining the importance of and interaction between exposure to AF and infection with hepatitis B virus (HBV) early in life.
Cultured stem‐cells from human testicular teratomas: The nature of human embryonal carcinoma, and its comparison with two types of yolk‐sac carcinoma
Authors: Pera Martin F. , Lafita M. J. Blasco , Mills Judith
Published: February 2007

The understanding of differentiation in human teratomas requires a better definition of the phenotype and developmental potential of the stem cells in these tumours. We describe the characterization of 6 new cell lines from human t asticular teratomas which are representative of 3 distinct cell types. Cell lines GCT 27, GCT 35, and GCT 48, identified as embryonal carcinoma, comprise epithelial cells which express cytokeratin intermediate filaments and desmoplakins, as' determined by indirect immunofluorescence microscopy. A minority of the cells also express vimentin. Most cells in these cultures show surface staining with monoclonal antibodies (MAbs) to stage‐specific embryonic antigens SSEA 3 and SSEA 4 but not SSEA 1. Staining with MAb W6/32, which recognizes HLA A,B and C chains in the presence of β‐2 microglobulin, is not above background level. When injected into nude mice, GCT 27 cells form tumours consisting of embryonal carcinoma, somatic tissues, and cells positive in immunocytochemical assays for alphafoetoprotein (AFP) and human chorionic gonadotrophin (HCG); GCT 35 cells form embryonal carcinomas with foci of AFP and HCG‐positive cells; and GCT 48 cells form embryonal carcinoma only. A second type of cell (GCT 72) displays some properties of rodent visceral endoderm. GCT 72 cells contain cytokeratin intermediate filaments, but not vimentin, and show very strong staining at cell borders with anti‐desmoplakin 1 + 11 antibody. At the cell surface, GCT 72 cells express the epitopes recognized by antibodies to SSEA 3, SSEA 4, and SSEA 1; staining with W6/32 is negligible. Levels of AFP in supernatants from GCT 72 cultures are in excess of 500 KIU/1. The tumours formed following inoculation of nude mice with GCT 72 cells are solid yolk‐sac tumours, with all cells strongly positive for AFP. A third cell type (GCT 44 and GCT 46), resembles in some ways rodent parietal endoderm. These cells uniformly coexpress keratin and vimentin intermediate filaments, but not desmoplakins. The determinants recognized by MAbs to SSEA 3, 4, or 1 are not detected on the majority of cells in these cultures. In striking contrast to the other teratoma lines, these cells can attach to untreated tissue culture plastic in serum‐free medium and may be serially cultivated under these conditions. The tumours formed in nude mice by these 2 cell lines are yolk‐sac carcinomas with endodermal sinus tumour histology. Thus, human testicular teratomas consist of epithelial cells which may be nullipotent, pluripotent or committed to extraembryonic endodermal differentiation. The phenotype of human embryonal carcinoma cells shares some common features with the progenitors of extraembryonic endoderm in the mouse.
Antibody response against the Epstein‐Barr virus‐coded nuclear antigen2 (EBNA2) in different groups of individuals
Authors: Seigneurin J. M. , Lavoue M. F. , Genoulaz O. , Bornkamm G. W. , Lenoir G. M.
Published: February 2007

Specific antibody responses against the 2 major subcomponents of EBNA, EBNAI and EBNA2 were evaluated, in order to study whether this serological study was beneficial compared to classical EBV serology. During this investigation, 491 sera, obtained from blood donors and patients with Burkitt's lymphoma (BL), nasopharyngeal carcinoma (NPC), infectious mononucleosis (IM), Hodgkin's disease, renal transplantation, rheumatoid arthritis and Human Immunodeficiency Virus (HIV) infection, were tested. While the anti‐EBNAI response followed the classical anti‐EBNA/Raji response (99% of anti‐EBNA/Raji‐positive sera also recognize EBNAI), the anti‐EBNAI response was much less frequent and did not correlate with either anti‐EBNA/Raji or anti‐EA antibodies. In a control population, 8% of individuals had anti‐EBNAZ antibodies at titers ≥ 10. The percentage was 45% In NPC and 38% in EBV‐associated BL; thus, although not detected in all patients with EBV‐associated tumors, anti‐EBNA2 serology might be a useful marker in BL and NPC. No antibody was detected in the early course of IM, but in rheumatoid arthritis and in HIV‐infected patients, the percentage of positive individuals reached 54 and 68, respectively. Seroconversion to EBNA2 was noted in a few cases, including renal transplant recipients, AIDS patients, and complicated IM. This suggests that in these situations, EBNA 2 serology might represent a useful marker related to modulation of the immune status or EBV reactivation.
Down‐regulation of the EBV‐encoded membrane protein (LMP) in burkitt lymphomas
Authors: Hatzubai A. , Anafi M. , Masucci Maria Grazia , Dillner J. , Lerner R. A. , Klein G. , Suutzeanu D.
Published: February 2007

A radioimmunoassay (RIA) has been developed and used to determine the expression of LMP—a membrane protein encoded by the LT3 region of the Epstein‐Barr virus (EBV) genome—in cell lines of various origins. The RIA was highly sensitive, specific and reproducible. All EBV‐negative cell lines were LMP‐negative and 18 of 21 EBV‐carrying cells were LMP‐positive. LMP concentrations varied widely, ranging approximately from less than 4 ng up to 650 ng/mg protein. In several instances comparisons were made between lymphoblastoid (LCLs) and Burkitt lymphoma (BL) cell lines (EBV‐positive or EBV‐co wetted sublines of originally EBV‐negative BL) originating from the same patient. In all such cases LMP and LMP‐specific mRNA levels were higher in the LCLs. Most of the LMP was found in the cytosol fraction, yet this fraction was negative in immunoblotting tests. However, antiserum preincubated with the cytosol lost its ability to react in immunoblotting with membrane LMP, indicating that the 2 LMP forms (membrane and cytosol) are completely cross‐reactive.
In vivo anti‐tumor activity of combinations of interferon alpha and interleukin‐2 in a murine model. Correlation of efficacy with the induction of cytotoxic cells resembling natural killer cells
Authors: Brunda Michael J. , Bellantoni Donna , Sulich Viveca
Published: February 2007

The in vivo anti‐tumor activity of 2 recombinant cytokines, interleukin‐2 (rIL‐2) and human hybrid interferon alpha (rHuIFN‐αA/D), were tested using the murine reticulum cell sarcoma M5076. Experimental hepatic metastases, following i.v. injection of tumor cells, and tumor growth and spontaneous metastases, following s.c. injection of tumor cells, were inhibited to a greater extent in mice treated with a comblnation of these cytokines than in animals treated with either one alone. When used in conjunction with surgical removal of the s.c. tumor, treatment of mice with both cytokines significantly prolonged survival of tumor‐bearing animals. Injection of normal mice with a combination of cytokines, but not with either cytokine alone, resulted in a marked increase in cytotoxic activity of hepatic effector cells. The effector cells in these mice appeared to be NK cells since this enhanced cytotoxicity was markedly reduced in animals treated in vivo with anti‐asialo GM1 or in NK‐deficient beige mice. Furthermore, no in vivo efficacy was observed in M5076‐bearing beige mice treated with these cytokines. Thus, injection of mice with rIL‐2 and rHuIFN‐αA/D results in the induction of an NK‐cell‐like population in the liver with enhanced cytotoxic activity that correlates with the observed anti‐tumor activity in vivo in this murine model. These results suggest that combinations of cytokines, in particular IFN‐α and IL‐2, can be effectively used in combination for the treatment of tumors and/or metastases.
MHC‐controlled susceptibility to C3H‐MTV‐induced mouse mammary tumors is predominantly systemic rather than local
Authors: Dux A. , Demant P.
Published: February 2007

The major histocompatibility complex (MHC) is one of the genetic factors involved in the control of susceptibility to MTV‐induced mammary tumors in mice. Previously, genetic differences in mammary tumor susceptibility were shown to be mainly due to differences in susceptibility of the mammary gland itself. Such experiments, however, were carried out using inbred strains which differ in many genes. Therefore, the conclusion drawn from such experiments is not necessarily applicable to every gene involved.

We tested whether in the strain C57BL/10 (B10, resistant) and the H‐2 congeneic strain B10. A(5R) (SR, susceptible), which differ only at the MHC, the MHC‐controlled difference in tumor susceptibility indeed resides in the mammary gland tissue itself, or is caused by systemic factors. Mammary glands of infant B10 and 5R mice were transplanted into mammary fat pads of C3H‐MTV‐infected mammectomized (B10 × 5R)F1 females. The hosts received a hypophyseal isograft under the kidney capsule or were subjected to force‐breeding to provide hormonal stimulation necessary for mammary tumor development. Control groups of C3H‐MTV‐infected B10, 5R and (B10 × 5R)F1 females and (B10 × 5R)F1 females without C3H‐MTV were also subjected to the 2 types of hormonal stimulation. There was no difference in susceptibility between the 5R and BIO mammary glands transplanted into C3H‐MTV‐infected F, hybrid hosts. On the other hand, C3H‐MTV‐infected 5R and (B10 × 5R)F1 females were significantly more susceptible than the C3H‐MTV‐infected B10 females, when either of the 2 methods of hormonal stimulation was used. This indicates that, in the strains used, MHC‐controlled susceptibility to C3H‐MTV‐induced mammary tumorigenesis is predominantly or exclusively controlled by systemic factors rather than by factors residing in the target tissue.
Suppression of NK activity of spleen cells by chicken fetal antigen present on Marek's disease lymphoblastoid cell line cells
Authors: Ohashi Kazuhiko , Mikami Takeshi , Kodama Hiroshi , Izawa Hisao
Published: February 2007

Chicken fetal antigen (CFA) expressed on the cell surface of Marek's disease (MD) lymphoblastoid cell line (MDCC‐MSBI) cells was purified by affinity chromatography using a monoclonal antibody (2H3). A 4‐hr 51Cr release assay was performed using spleen cells as effector cells to investigate the role of the CFA in the immune response of chickens, especially in relation to natural killer (NK) activity. Spleen cells of specific‐pathogen‐free (SPF) chickens showed reduced NK activity in the presence of CFA in vitro, as did those cells treated with MSBI soluble antigen. NK activity of spleen cells from chickens treated with CFA was also suppressed when compared to the cells from untreated or ovalbumin‐treated chickens. In addition, MSBI clo. 18 transplantable tumors grew progressively in some of the 14‐day‐old chickens treated with CFA, whereas the tumors regressed in age‐matched chickens with or without treatment by ovalbumin.
Stable transfection of a human lymphoma line by sub‐genomic fragments of Epstein‐Barr virus DNA to measure humoral and cellular immunity to the corresponding proteins
Authors: Welinder Christina , Larsson Nils‐Göran , Szigeti Robert , Ehlin‐Henriksson Barbro , Henle Gertrude , Henle Werner , Klein George , Ricksten Anne , Rymo Lars , Sulitzeanu Dov
Published: February 2007

An Epstein‐Barr virus (EBV)‐negative human lymphoid B‐cell line, DG75, was stably transfected with recombinant selection vectors that carry a subfragment of the BamHI WYH region (nucleotides 44664 to 50628), the BamHI K fragment, or a subfragment of the EcoRI D region (nucleotides 166614 to 170149) of B95‐8 EBV DNA. These fragments contain the coding exons for the EBV‐determined nuclear antigens EBNA2 and EBNA1, and the membrane antigen LMP, respectively. Antigen expression of the cells was detected by immunofluorescence. EBNA2 was expressed in 80–100% of the transfected cells, in contrast to EBNA1 which was expressed in only 25%, and LMP in only about 5% of the cells. Humoral antibody responses were measured by immunofluorescence and compared to cellular immunity as determined by the leukocyte migration inhibition (LM1) technique. Extracts from transfected cell lines expressing EBNA1, EBNA2 or LMP elicited an LMI response with cells from healthy EBV‐seropositive individuals whereas the extract from the parental DG75 cell line did not, The results demonstrate the value of stably transfected cell lines expressing a defined EBV antigen for the monospecific analysis of host responses to the EBV‐encoded antigen complex in growth‐transformed cells.
Cell shape modulation alters glycosylation of a metastatic melanoma cell‐surface antigen
Authors: Nabi Ivan R. , Raz Avraham
Published: February 2007

B16‐F1 melanoma cells cultivated in vitro as spheroids on a non‐adhesive substrate acquire in a reversible fashion an increase in lung colonization in vivo as compared to cells cultured as a monolayer. After neuraminidase treatment of protein blots, the spheroidal cells expressed an increased binding of 125I‐labelled peanut lectin (PNA) to a unique glycoprotein of Mr78,000 (gp78) which after desialylation migrated in SDS‐polyacrylamide gels as an Mr86,000 protein. Antibodies were generated against this glycoprotein purified on PNA‐Sepharose and its expression on the surface of viable B16‐F1 cells was demonstrated. Growth of B16‐F1 melanoma cells in suspension is associated with the altered glycosylation of gp78 which may be related to the increased metastatic ability of these cells. In vitro treatment of B16‐F1 cells with anti‐gp78 Fab fragments prior to their injection into the tail veins of syngeneic mice resulted in a 2‐fold increase in the appearance of tumor lung colonies.
Protection of cynomolgus monkeys against infection by human T‐cell leukemia virus type‐I by immunization with viral env gene products produced in Escherichia coli
Authors: Nakamura Hideo , Hayami Masanori , Ohta Yoshihiro , Ishikawa Koh‐Ichi , Tsujimoto Hajime , Kiyokawa Tetsuyuki , Yoshida Mitsuaki , Sasagawa Akira , Honjo Shigeo
Published: February 2007

Protection against human T‐cell leukemia virus type‐1 (HTVL‐1) infection in cynomolgus monkeys, achieved by immunizing the animals with env gene products of HTLV‐I produced in Escherichia coll, was evaluated. Four monkeys that had been immunized with the env product produced antibody against HTLV‐I gp68 and gp46, and their sera were found to cause strong inhibition of syncytium formation of a cat fibro‐blast cell line induced by HTLV‐I. Immunized and non‐immunized monkeys were challenged with live MT‐2 cells, a high HTLV‐I‐producer cell line. After challenge, all the control nonimmurized monkeys were infected with HTLV‐I, as judged by the frequent detection of HTLV‐I‐antigens in cultures of their peripheral blood mononuclear cells (PBMC), whereas no antigens were recovered from PBMC of immunized monkeys. These results indicate that humoral immunity against HTLV‐I‐envelope protein elicited by immunization with the polypeptides synthesized in bacteria protected the monkeys against primary infection with HTLV‐I.
Activation of endogenous MMTV proviruses in murine mammary cajncer induced by chemical carcinogen
Authors: Knepper Janice E. , Medina Daniel , Butel Janet S.
Published: February 2007

A study was undertaken to determine whether activation of expression of silent endogenous mouse mammary tumor virus (MMTV) proviruses may occur during tumor induction by a chemical carcinogen. A series of transplantable mammary tumors induced in BALB/c mice by treatment with dimethylbenz(α)anthracene (DMBA), pituitary isograft, or both was examined. The results obtained suggest that chemical carcinogens may induce mammary tumors through more than one pathway. Two of 9 tumor lines produced virus‐specific products at levels above those observed during the Course of normal mammary gland development. One tumor contained high levels of MMTV‐specific envelope [3.8 kilobase (kb)] and genomic length (8.9 kb) RNAs. This tumor expressed core‐and envelope‐related proteins detectable by immuno‐blotting (including p28, gp52, and gp36), displayed an acquired provirus with a restriction map different from those of described exogenous MMTV strains, and contained abundant virus particles. The other tumor that expressed high levels of MMTV gene products contained envelope‐specific (3.8 kb) and long‐terminal‐repeat‐specific (1.6 kb) messages but no full‐length RNA. It exhibited an aberrant 39 kDa, envelope‐related protein, but no virus particles. Methylation data implicated the usually silent endogenous Mtv‐8 provirus as the source of the abnormal envelope protein. None of the tumors expressed RNA from the putative mammary oncogenes, int‐1 or Int‐2. We propose that chemical carcinogens may activate different cellular genes by mutation and that, in a subset of DMBA‐induced mammary tumors, the target genes include endogenous MMTV proviruses that are normally not expressed. The effect on provirus expression varies from tumor to tumor, but is stable over passage of a given tumor. MMTV may be of etiological importance in the genesis of those DMBA‐induced tumors which contain high levels of MMTV‐specific products, but its action in the BALB/c system is not mediated through enhanced expression of the int‐1 or int‐2 preferred integration regions.
Effects of age, birth cohort and period of death on Swiss cancer mortality, 1951–1984
Authors: Levi Fabio , La Vecchia Carlo , Decarli Adriano , Randriamiharisoa Alex
Published: February 2007

Swiss death certification data over the period 1951–1984 for total cancer mortality and 30 major cancer sites in the population aged 25 to 74 years were analysed using a log‐linear Poisson model with arbitrary constraints on the parameters to isolate the effects of birth cohort, calendar period of death and age. The overall pattern of total cancer mortality in males was stable for period values and showed some moderate decreases in cohort values restricted to the generations born after 1930. Cancer mortality trends were more favourable in females, with steady, though moderate, declines in both cohort and period values. According to the estimates from the model, the worst affected generation for male lung cancer was that born around 1910, and a flattening of trends or some moderate decline was observed for more recent cohorts, although this decline was considerably more limited than in other European countries. There were decreases in cohort and period values for stomach, intestine and oesophageal cancer in both sexes and (cervix) uteri in females. Increases were observed in both cohort and period trends for pancreas and liver in males and for several other neoplasms, including prostate, brain, leukaemias and lymphomas, restricted, however, for the latter sites, to the earlier cohorts and hence partly attributable to improved diagnosis and certification in the elderly. Although age values for lung cancer in females were around 10‐times lower than in males, upward trends in female lung cancer cohort values were observed in subsequent cohorts and for period values from the late 1960's onwards. Therefore, future trends in female lung cancer mortality should continue to be monitored. The application of these age/period/cohort models thus provides a summary guide for the reading and interpretation of cancer mortality trends, although it cannot replace careful inspection of single age‐specific rates.
Case‐control study of human papillomaviruses and cervical cancer in Latin America
Authors: Reeves William C. , Caussy Deoraj , Brinton Louise A. , Brenes Maria M. , Montalvan Patricia , Gomez Basilio , De Britton Rosa C. , Morice Eugenio , Gattan Eduardo , De Lao Suzanne Loo , Rawls William E.
Published: February 2007

Human papillomavirus (HPV) types 16 and 18 have been implicated as risk factors for cervical dysplasla and neoplasia. However, most studies have been observational, uncontrolled and conducted in populations at low risk for invasive cancer. We r sport a pilot case‐control study of incident invasive cervical cancer in Panama, Costa Rica and Bogota, Colombia. Between July and September 1985 we enrolled 46 consecutive newly diagnosed invasive cervical cancer cases and 51 age‐matted control women. Subjects were interviewed and samples collected for HPV DNA assays. HPV infection was defined by a filter in situ DNA hybidization technique under non‐stringent and stringent conditions against HPV‐6/11, 16 and 18 DNA probes. More cases (91 %) than controls (63%) had HPV DNA detected (non‐stringent) and more cases than controls had HPV‐16 or 18 DNA (67% vs. 43%, p = 0.02). Age at first intercourse was the most significant risk factor for HPV 16/18 Infection in all subjects. Smoking was significantly associated with cervical cancer (52% of cases vs. 27% controls) but was not associated with HPV infection.
Cellular and humoral immune responses to synthetic peptides deduced from the amino‐acid sequences of Epstein‐Barr virus‐encoded proteins in EBV‐transformed cells
Authors: Dillner Joakim , Szigeti Robert , Henle Werner , Henle Gertrude , Lerner Richard A. , Klein George
Published: February 2007

Ten synthetic peptides containing 18–22 residues deduced from the amino‐acid sequences of the EBV‐encoded latent‐infection‐associated membrane protein (LMP) and the 2 principal nuclear antigens, EBNA‐1 and EBNA‐2, were tested for their ability to induce lymphokine release from sensitized T‐cells of EBV‐seropositive donors, as measured by the leukocyte migration inhibition assay (LMI). Only one of the 10 free peptides induced EBV‐speeific LMI. After Sepharose‐coupling, 4 additional peptides were regularly active. In parallel, the sera of the same and other donors were screened for synthetic peptide‐blnding antibodies, as measured by an ELISA assay. Antibodies to 9 of the 10 peptides were detected in 25–80% of EBV‐antibody‐positive, but not in EBV‐antibody‐negative sera. A comparison of the two responses indicates that the humoral immune system tends to react with more epitopes on a given protein than the cellular immune system. Furthermore, the antibody reactivity pattern to different epitopes is more variable from individual to individual than the T‐cell response. Also, the epitopes detected by antibodies and sensitized T‐cells are often not identical.
Specific abnormalities of chromosome 14 in patients with acute type of adult T‐cell leukemia/lymphoma
Authors: Miyamoto Kanji , Tomita Noriko , Ishn Akio , Miyamoto Naoaki , Nonaka Hiroshi , Kondo Toshifumi , Sugihara Takashi , Yawata Yoshihito , Tada Shinya , Tsubota Teruhiko , Kitajima Koichi , Kimura Ikuro
Published: February 2007

Chromosome analysis was performed on I patient with diffuse lymphoma of mixed type by histologic diagnosis and on 7 patients with the acute type of adult T‐cell leukemia (ATL). Specific abnormalities in chromosome 14 at break band q11 with the assigned locus of the α‐chain gene of the T‐cell antigen receptor were identified in 6 of 8 patients. Inv(l4) (q11q32) was found in 2 patients and translocation of chromosome 14 at break band q 11 was observed in 4. Donor chromosomes involved in translocation of the 14q11 varied, i.e., chromosomes 3, 7 or X, with the exception of one patient whose donor chromosome origin could not be determined. The breakpoint in chromosome 3 was in band p25, a region reported to include the locus of the c‐raf‐l oncogene. In chromosome 7, it was in band p11, a region reported to include the locus of the c‐erb‐B oncogene, and in the sex chromosome X, it was in band q11. One patient also had a chromosome 14 aberration at break band q32. Of the 2 remaining patients, one had lost chromosome 14 and the other had an isochro‐mosome 14q. Our observation and other reported findings suggest that the rearrangement of chromosome 14 at break band q11 is specific for lymphoma‐type or acute‐type ATL patients, and aberrations of proto‐oncogene expression or the coding sequence by recombination involving a T‐cell antigen receptor gene due to chromosome inversion or chromosome translocation may play an important role in T‐cell neoplasia including ATL.
Methylxanthines and breast cancer
Authors: Schairer Catherine , Brinton Louise A. , Hoover Robert N.
Published: February 2007

We investigated the relationship between methylxanthine consumption and breast cancer using data from a case‐control study which included 1,510 cases and 1,882 controls identified through a nation‐wide breast cancer screening program. There was no evidence of a positive association between methylxanthine consumption and risk of breast cancer. In fact, there was some suggestion of a negative association, particularly in women diagnosed after age 50. In addition, there was no evidence of increased risk with past or recent methylxanthine consumption, or with the consumption, of caffeine or specific beverages, most notably brewed or instant caffeinated coffee and tea.
Lack of correlation between rare Ha‐ras alleles and urothelial cancer in Japan
Authors: Ishikawa Jiro , Maeda Sakan , Takahashi Rei , Kamidono Sadao , Sugiyama Taketoshi
Published: February 2007

Restriction fragment length polymorphism (RFLP) of Haras gene was surveyed by Southern blot analysis in leukocyte DNA from 55 normal individuals and 58 urothelial cancer patients in Japan. Three common alleles and 4 rare alleles were classified. The frequency of common alleles in normal Japanese individuals differed from that in Caucasians previously reported; a 7.2–7.5‐kb Bam HI fragment of common al‐lele wits not observed in Japanese individuals. No significant increase in frequency of the rare Ha‐ras allele was observed in the group of cancer patients. Moreover, no significant different in frequency was observed for the 3 common alleles. Tumor DNA was compared with leukocyte DNA in 30 urothelial cancer patients: in 3 of 8 cases with heterozygous Haras locus, decreased intensity of one band, indicating partial loss of one allele in tumor DNA, was observed. In 3 tumors with either deletion of one Ha‐ras allele or a rare Ha‐ras allele, expression of Ha‐ras gene was examined by Northern blot aralysis. Such genetic alterations did not always result in a marked increase in Ha‐ras expression. These data suggest that tl‐ese genetic alterations are not directly related to Haras expression, and that RFLP of Ha‐ras gene is not a useful genetic marker for urothelial cancer. On the other hand, deletion of one Ha‐ras allele was observed in 1 of 5 cases of bladde‐ cancer and in 2 of 3 cases of renal pelvic cancer, suggesting that that deletion may be important in the development of urothelial cancer.
Interleukin‐2‐stimulated natural killer activity against malignant and benign endometrium
Authors: Timonen Tuomo , Lehtovirta Pentti , Saksela Eero
Published: February 2007

Natural cell‐mediated immunity against autologous tumor cells, autologous endometrial epithelium, and allogeneic epi‐dermoid carcinoma cell line HeLa was tested in 8 patients with endometrial carcinoma and one patient with endome‐irial stromal sarcoma. The average cytotoxicity of unstimu‐lated peripheral blood lymphocytes against autologous tumor and HeLa cells was weak but significant. Pretreatment of effector cells for 3–5 days with 300 U/ml recombinant inter‐leukin‐2 (rIL‐2) resulted in increased cytotoxicity against malignant target cells in 7 out of 9 cases. The 2 patients' effector cells which were refractory to rIL‐2 could be stimulated to; ppreciable lytic activity against the malignant target cells with a recently described cytokine which induces morphological differentiation of natural killer cells. Benign endometrial cells were weakly sensitive to rIL‐2‐activated lysis in 2 cases. The precursors of the rIL‐2‐activated killer cells were mostly CD16‐positive and CD3‐negative, and co‐sedimented with endogenous natural killer cells in discontinuous density gradient centrifugations. These results indicate the rIL‐2‐activated killer cells have a capacity to distinguish between normal and malignant endometrial cells, and that the precursors of the lytic cells in this system belong to the same subpopulation of lym‐phocytes as endogenous natural killer cells. In addition, rIL‐2 alone may not in all cases be sufficient for optimal generation of cytotoxicity against malignant cells.
A case‐control study of diet and gastric cancer in Northern Italy
Authors: La Vecchia Carlo , Negri Eva , Decarli Adriano , D'Avanzo Barbara , Franceschi Silvia
Published: February 2007

Dietary factors in the aetiology of stomach cancer were investigated using data from a case‐control study conducted in Northern Italy on 206 histologically confirmed carcinomas and 474 control subjects in hospital for acute, non‐digestive conditions, unrelated to any of the potential risk factors for giistric cancer. Dietary histories concerned the frequency of consumption per week of 29 selected food Items (including ttie major sources of starches, proteins, fats, fibres, vitamins A and C, nitrates and nitrites in the Italian diet) and subjective stores for condiments and salt intake. Pasta and rice (the rajor sources of starch), polenta (a porridge made of maize) and ham were positively related with gastric cancer risk, whereas green vegetables and fresh fruit as a whole (and specifically citrus fruit) and selected fibre‐rich aliments (such aii whole‐grain bread or pasta) showed protective effects on giistric cancer risk. Allowance for major identified potential distorting factors (chiefly indicators of socio‐economic status) reduced the positive association with pasta or rice consumption, but did not appreciably modify any of the other risk estimates. When a single logistic model was fitted including all food items significant in univariate analysis, the 3 items remaining statistically significant were green vegetables (rel‐acive risk, RR = 0.27 for upper vs. lower tertile), polenta (f;R = 2.32) and ham (RR = 1.60). Indices of beta‐carotene and ascorbate intake were negatively and strongly related with giistric cancer risk, but the association with these micronu‐trients was no longer evident after simultaneous allowance for various food items. An approximately 7‐fold difference in risk was found between extreme quintiles of a scale measuring major positive and negative associations.
Phenotypic and functional analysis of human CD3 + and CD3− clones with “lymphokine‐activated killer” (LAK) activity. Frequent occurrence of CD3 + LAK clones which produce interleukin‐2
Authors: Mingari M. C. , Ferrini S. , Pende D. , Bottino C. , Prigione I. , Moretta A. , Moretta L.
Published: February 2007

Clones capable of lysing fresh, uncultured tumor cells (“lym‐phokine‐activated killer”: “LAK” activity) were selected from microcultures derived from either E‐rosette‐positive or E‐ rosette‐negative cell populations. All the selected clones displayed a strong cytolytic activity against the NK‐sensitive K562 cell line. Two major phenotypic groups of clones could be identified: a first group expressed the CD3 differentiation antigen, present exclusively on mature T lymphocytes; however, in contrast to typical cytolytic T lymphocytes, the majority of these clones expressed the unusual CD4‐ CD8‐ phenotype, whereas the remainder were CD4‐ CD8 +. A second group was represented by CD3 ‐ clones which, in most instances, expressed the T‐cell‐lineage‐specific CD2 antigen. Following stimulation with phytohemagglutinin (PHA), most of the CD3 + LAK clones produced lnterleukin‐2 (1L‐2) and interferon‐γ (1FN‐γ) whereas those expressing the CD3 ‐ phenotype did not. Since previous studies indicated that PHA may be inefficient in inducing lymphokine production by T‐ cell variants lacking the CD3/T cell receptor complex (TCR), CD3 ‐ clones were further stimulated with the calcium iono‐phore A23187 plus phorbol 12‐myristate 13‐acetate (PMA). Only 2/11 CD3 ‐ LAK clones produced small amounts of IL‐2, whereas the majority released 1FN‐γ. Given the peculiar phenotypic and functional properties of many CD3 + LAK clones, we suggest that they may belong to a T‐cell subset distinct from typical CTLs.
Cell‐surface laminin‐like molecules and α‐D‐galactopyranosyl end‐groups of cloned strongly and weakly metastatic murine fibrosarcoma cells
Authors: Grimstad Ivar Amund , Bosnes Vidar
Published: February 2007

Indications from previous work that cancer cell‐surface laminin‐like molecules and α‐D‐galactopyranosyl end‐groups may contribute to spontaneous metastasis were further investigated. Both moieties are known to mediate cell attachment to various foreign surfaces. Five strongly metastatic and 5 weakly metastatic cell clones from a murine fibrosarcoma were examined for the occurrence of both cell‐surface moieties by immunofluorescence flow cytometry and micros‐ copy. None of these clones was rich in laminin‐like molecules, Which were least strongly expressed by the highly metastatic Clones. The α‐D‐galactopyranosyl end‐groups were strongly expressed by all strongly metastatic clones and by 2 weakly metastatic clones, but were only weakly expressed by the other weakly metastatic clones. These results indicate that the laminin‐like cell‐surface molecules are not necessary for spontaneous metastasis formation. However, the α‐D‐galactopyranosyl end‐groups may be necessary, but are not sufficient for the cancer cells to form metastases. These carbohydrates are known to occur on the laminin‐like molecules. The present results show that they must also exist on other cell‐surface molecules.
Evidence that sulphated polysaccharides inhibit tumour metastasis by blocking tumour‐cell‐derived heparanases
Authors: Parish Christopher R. , Coombe Deirdre R. , Jakobsen Karen B. , Bennett Francis A. , Underwood P. Anne
Published: February 2007

Recent studies in this laboratory demonstrated that several sulphated polysaccharides can inhibit metastasis of the rat mammary adenocarcinoma 13762 MAT, probably by preventing the passage of tumour cells through the walls of blood vessels. In order to directly test this possibility, 13762 MAT cells were cultured with (35S)O4=‐labelled subendothelial extracellular matrices (ECM) and ECM degradation was monitored in either the presence or absence of different sulphated polysaccharides. Degradation products were detected by sodium dodecyl sulphate polyacrylamide gel electrophoresis and subsequent autoradiography. The 5 sulphated polysaccharides that had previously been shown to possess anti‐metastatic activity were potent inhibitors of the degradation of subendothelial ECM by 13762 MAT cells. In contrast, of the 4 polysaccharides tested that failed to inhibit metastasis, 3 had no effect on ECM breakdown and one (carrageenan‐kappa) was substantially less effective at inhibiting ECM degradation than the anti‐metastatic preparations. It was also shown that 13762 MAT cells produce a heparan sulphate‐specific glycosidase (heparanase) that degrades the heparan sulphate side‐chains of the ECM, the action of this enzyme rather than that of other ECM‐solubilizing enzymes being inhibited by the anti‐metastatic sulphated polysaccharides. Additional experiments indicated that the anti‐coagulant activity of the polysaccharides probably plays a minor role In their anti‐metastatic effects since heparin, almost completely depleted (98–99.5%) of heparin molecules with anti‐coagulant activity by passage over an anti‐thrombin III column, retained its ability to inhibit 13762 MAT heparanases and was almost as effective as unfractionated heparin at inhibiting tumour‐cell metastasis. Collectively, these data suggest that sulphated polysaccharides inhibit the metastasis of 13762 MAT cells by inhibiting tumour‐cell‐derived heparanases involved in the penetration of the vascular endothelium and Its underlying basement membrane by tumour cells.
Adhesion of human breast cancer cell line MCF‐7 to human vascular endothelial cells in culture. enhancement by activated platelets
Authors: Abecassis Joseph , Millon‐Collard RéGine , Klein‐Soyer Claude , Nicora Francesca , Fricker Jean‐Pierre , Beretz Alain , Eber Michel , Muller Danièle , Cazenave Jean‐Pierre
Published: February 2007

The interactions of MCF‐7 tumor cells with human vascular endothelial cells (EC) and subendothelial extracellular matrices (ECM) were morphologically observed by electron microscopy and quantitatively evaluated by labelling tumor cells with 111Indium‐oxine. MCF‐7 tumor cells adhered more rapidly to ECM than to the apical surface of a confluent monolayer of EC. The affinity of MCF‐7 cells for type‐IV collagen was greater than for fibronectin, suggesting that type‐IV collagen contributes to the higher rate of adhesion of MCF‐7 cells to the subendothelial ECM. Otherwise, the attachment of tumor cells to EC was increased in the presence of both washed platelets and 0.1% citrated platelet‐poor plasma (cPPP), a condition accelerating platelet aggregation by tumor cells. The enhancement of MCF‐7 adhesion to EC in the presence of platelets and cPPP was completely blocked by the addition of prostacyclin, or hirudin, a specific thrombin inhibitor. In ultrastructural studies, MCF‐7 initiated EC retraction, and firm attachment and flattening occurred on exposed ECM. When MCF‐7 cells were incubated with platelets and cPPP, most of the tumor cells adhering to the EC and inducing disruption of endothelial monolayer were closely packed and associated with platelet aggregates. MCF‐7 cells appeared to adhere more efficiently to exposed subendothelial ECM when they were associated into multicellular aggregates containing platelets and trapped in a fibrin thrombus. Thus, this homologous human system of cultured vascular EC and breast carcinoma line MCF‐7 cells may be used to assess anti‐aggregant compounds for their ability to alter tumor‐cell implantation on EC‐lined surfaces.
The role of chromosome 15 in murine leukemogenesis. II. Relationship between tumorigenicity and the dosage of lymphoma vs. normal‐parent‐derived chromosomes 15 in somatic cell hybrids
Authors: Uno Masatsune , Wirschubsky Zvi , Babonits Magda , Wiener Francis , Sümegi Janos , Klein George
Published: February 2007

Somatic cell hybrids were generated between an MCF‐vi‐rus‐induced 15‐trisomic T‐cell lymphoma of AKR origin with a proviral insertion near the c‐myc locus, and normal diploid fibroblasts or lymphocytes of CBAT6T6 origin. Three lymphoma/fibroblast fusions were performed. Six independently‐derived clones from 2 fusions were tested for tumorigenicity. Three of the 6 clones were weakly malignant (take incidence 20% below), and 3 were strongly malignant (take incidence over 80%). All 3 lymphoma/lymphocyte hybrids and 6 derived clones were strongly malignant. All hybrids contained a nearly complete chromosomal complement of both parental cells. This was confirmed at the molecular level by determining the ratio of germ‐line (G) vs. rearranged (R) myc‐carrying Eco RI fragments that showed the expected 1.9–2.7:1 proportion. Malignant segregants selected from the weakly malignant lymphoma/fibroblast hybrids by in vivo inoculation showed changed 15‐chromosome ratios. Four out of the 6 clones showed amplification of the lymphoma‐derived 15‐chromosome that carries the R‐myc fragment and a concomitant decrease in the average number of the G‐myc‐carrying chromosomes. This was deduced from the fact that the G:R ratio was between 2 and 3:1 in the in vitro hybrids but became inverted (1:2–3) in the tumors. Two tumors showed no amplification of R‐myc. C‐myc was decreased. One of these tumors showed a change in the G:R ratio from 2.5:1.0 to 1.2:1.0, while the other was essentially unchanged (1.9:1.0 in the in vitro clone and 2.2:1.0 in the derived tumor). These findings support the notion that both the amplification of the lymphoma‐derived 15‐chromosome with the retro virally rearranged c‐myc carrying fragment and/or the loss of the G‐myc‐carrying 15‐chr can contribute to the tumorigenic potential of the hybrids.
Anti‐tumor activity of recombinant mouse tumor necrosis factor (TNF) on colon cancer in rats is promoted by recombinant rat interferon gamma; toxicity is reduced by indomethacin
Authors: Marquet R. L. , Ijzermans J. N. M. , De Bruin R. W. F. , Fiers W. , Jeekel J.
Published: February 2007

The activity and toxlcity of rMuTNF, alone or combined with rat recombinant interferon gamma (rRIFNγ), was tested in inbred WAG rats bearing a weakly immunogenic colon adeno carcinoma (CC531). The tumor was implanted s.c. or under the renal capsule. A single i.v. injection of 10μg of rMuTNF in non‐tumor bearers was lethal in 3 to 5 hr, whereas 2μg was nat. Doses of 1μg rMuTNF were well tolerated when given daily for one week. The most prominent toxic feature was hemorrhagic colitis which could be alleviated when rMuTNF was preceded by i.p. administration of 10mg/kg indomethacin. Three intralesional injections of 10μg rMuTNF on days 0, 10 and 15 into s.c. tumors (diameter 1–1.5cm) led to a moderate retardation of growth in 20% of the cases. Combined with 105 units of rRIFNμ, which on its own had no effect, the overall response rate (arrest of tumor growth or regression) was 50%. Two out of 20 tumors treated intralesionally with rMuTNF and rRlFNγ regressed. The subrenal capsule assay was used to study the possible interference of indomethacin with the anti‐tumor activity of rMuTNF. Tumor cubes of 6–8mg were implanted under the renal capsule; the test was evaluated by weighing. Treatment with 10mg indomethacin alone on days 0, 2 and 4 had no effect (40 ± 8 mg vs. 48 ± 13 mg in controls) whereas 2μg of rMuTNF on the same days resulted in significant tumor inhibition (24 ± 7 mg, p < 0.001). The combined administration of 2μg of rMuTNF and indomethacin had an effect similar to that of rMuTNF alone (25 ± 9 mg). Under protection of indomethacin the rMuTNF dose was increased from 2μg to 10μg. However, this did not lead to further improvement of the results.
Tumor‐promoting activity of extracts of human semen in cancar mice
Authors: Tokuda Harukuni , Ito Yohei , Kanaoka Toshio , Yoshida Osamu
Published: February 2007

Application of ether extracts of pooled human semen that induce Epstein‐Barr virus (EBV) activation promoted skin tumor production in female SENCAR mice previously treated with 100μg of 7, 12‐dimethylbenz(a)anthracene(DMBA). Twice‐weekly applications of 60 μg ether extract samples produced p apillomas in SENCAR mice. Several samples of human semen vrere tested to determine the relationship between tumor‐promoting activity and EBV activation in human semen. Pooled human semen that induced more than 10% EBV activation effectively promoted tumor production, but samples that induced less than 0.1% EBV activation were ineffective.
Experimental combination chemotherapy of ACNU and 5‐FU against cultured glioma model (spheroid) and subcutaneous rat glioma
Authors: Kitahara Masakazu , Katakura Ryuichi , Suzuki Jiro , Sasaki Takehito
Published: February 2007

The effects of combination chemotherapy of ACNU and 5‐FU on cells grown exponentially as monolayers, cells in multi‐cell spheroids and in s.c. transplanted tumors of rat glioma clone‐6 cells were analyzed by the colony‐forming assay. The cytotoxic effect of ACNU on cells in spheroids was enhanced by continuous 5‐FU pretreatment for several hours, but further enhancement was obtained only if the 5‐FU pretreatment lasted for more than 12 hr. The combined effect was decreased by a drug‐free interval due to recovery from potentially lethal 5‐FU damage, but ACNU treatment immediately after 5‐FU treatment suppressed PUD recovery. Analysis with sequential trypsinization of spheroids indicated that ACNU showed more marked cytotoxicity on cells in the deeper layers in spheroids than on those in the outer layers, whereas the effect of 5‐FU decreased towards the deeper cell layers. Enhancement of treatment with ACNU combined with 5‐FU was evident for cells in the outer layers, but was more remarkable in the deeper layers. The combined effect of ACNU and 5‐FU on s.c. tumors was similar to that in spheroids. The effect of combined treatment of ACNU with 5‐FU on increase in body weight was within the additive range of both drugs acting independently, but was more than additive for the growth delay of s.c. tumors.
Structural abnormality and over‐expression of the myc gene in feline leukemias
Authors: Miura Tomoluki , Tsujimoto Hajime , Fukasawa Masashi , Kodama Toshiaki , Shibuya Masabumi , Hasegawa Atsuhiko , Hayami Masanori
Published: February 2007

Tumor cells of feline leukemia were examined for structural abnormality and expression of the myc gene. Four of 12 spontaneous leukemia cases showed structural abnormalities of the myc gene detected by Southern blotting analysis. Of these 4 cases, one (Case I) showed a DNA rearrangement in the 5′ portion of the c‐myc locus associated with integration of feline leukemia virus (FeLV) genome. Another case had a newly inserted myc gene which was transduced by FeLV. In the 2 other cases, no relation of abnormalities of the myc gene to FeLV was detected. One case of experimental leukemia induced by inoculation of a cell line, FT‐1, established from Case I shoved a c‐myc gene rearrangement similar to that observed in Case I. Expression of myc RNA was examined in 3 leukemia T‐cell lines, FT‐1, FL74 and F422, by Northern blotting analysis. A high level of myc transcript was detected in all 3 cell lines. The size of myc RNAs in FT‐1 and FL74 was the same as that of normal myc RNA, white in F422 which had myc‐containing FeLV (myc‐FeLV), the full genome and spliced form of myc‐FeLV viral RNA were detected.
Non‐toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre‐treatment
Authors: Taper Henryk S. , De Gerlache Jacques , Lans Marc , Roberfroid Marcel
Published: February 2007

The influence on the survival of ascitic liver tumor (TLT)‐bearing mice of combined vitamins C and K3 administered before or after a single i.p. dose of 6 different cytotoxic drugs, all commonly used in human cancer therapy, was investigated. Combined i.p. administration of these vitamins produced a distinct chemotherapy‐potentiating effect for all drugs examined, especially when injected before chemotherapy. This potentiating treatment did not increase the general and organ toxicity that accompanies cancer chemotherapy. The possible generation of peroxides followed by membrane lipid alteration, DaNase activation and DNA destruction by combined vitamin C and K3 in catalase‐deficient cancer cells might be involved in the mechanisms of this selective potentiation.