bluuebunny/crossref_metadata_2025_split huggingface dataset:
Age at any birth and breast cancer risk
Authors: Trichopoulos Dimitrios , Hsieh Chung‐Cheng , Macmahon Brian , Lln Tong‐Ming , Lowe C. Ronald , Mirra Antonio P. , Ravnihar Bočena , Salber Eva J. , Valaoras Vasilios G. , Yuasa Shu 
Published: February 2007

AbstractIn an effort to assess the relative importance of age at first birth, age at subsequent births, and total parity to the occurrence of breast cancer, reproductive data from 4,225 women with breast cancer and 12,307 hospitalized women without breast cancer were analyzed by a multiple logistic regression model. Age at first birth was confirmed to be the most important reproductive risk indicator; it was associated with a 3.5 % increase of relative risk for every year of increase in age at first birth (the 95 % confidence interval of this estimate was 2.3 to 4.7 % increase per year). However, age at any birth after the first was also an independent and statistically significant risk indicator; it was associated with a 0.9% increase of relative risk for every year of increase in age at any (and every) birth (the 95 % confidence interval of this estimate was 0.4 to 1.5 % increase per year). There is evidence that the age of approximately 35 years represents for every birth a critical point; before this age any full‐term pregnancy confers some degree of protection; after this age any full‐term pregnancy appears to be associated with increase in breast cancer risk. The effect of parity is determined by the age of occurrence of the component pregnancies. While most pregnancies occur under the age of 35, the distribution varies from population to population, and this may account for the differences between populations in whether or not a protective effect is seen for births after the first, and if it is seen, its extent.
A semi‐automated procedure for aiding the diagnosis of cervical neoplasms based on the measurement of acid‐labile dna in exfoliated cells
Authors: Sincock A. M. , Middleton J. 
Published: February 2007

AbstractMeasurements of acid‐labile fractions of DNA in cells exfoliated from cervical neoplasms (invasive squamous‐cell carcinomas) using Feulgen techniques have shown elevated values in both abnormal and cytologically normal cell nuclei. These increased values occur early in the hydrolysis profiles before the Feulgen hydrolysis optimum for the cell nuclei of normal patients has been attained. They are of sufficient magnitude to enable a microcomputer programmed in BASIC to distinguish between normal and abnormal cells, even when the latter are of cytologically normal appearance. By semi‐automating the measurement procedure using a microcomputer interfaced with a Vickers M86 microdensitometer, the assessment of acid‐labile DNA in cell nuclei is proposed as a useful aid to the existing cytological diagnosis of cervical neoplasms.
The mechanism of interferon effect on cell transformation by murine sarcoma virus
Authors: Huleihel Mahmoud , Marvit Joshua , Aboud Mordechai 
Published: February 2007

AbstractMousee interferon (IFN) was found to inhibit murine sarcoirus (MSV)induced neoplastic transformation of normal rat kidney (NRK) cells. This effect was observed upon examining the formation of foci of morphologically altered cells and colonies of anchorage‐independent cells. IFN had no cytotoxic effect on MSV‐transformed NRK cells, nor on their focus or colony‐forming ability. It was therefore apparent that its inhibitory effect was directed against the viral role in cell transformation. In attempts to define the mechanism of this effect, we found that IFN delayed the initiation of the cytoplasmic viral DNA synthesis. However, the amount of this DNA eventually formed in IFN‐treated cells was the same as in the control cells. Furthermore, the transport of this DNA to the nucleus was slower in IFN‐treated cells, although all of it was finally transferred. However, while most of the viral DNA integrated into the genome of the control cells, very little integration occurred in IFN‐treated cells. The uninte‐grated viral DNA of these cells was slowly degraded. Therefore, if the cells recovered from the antiviral effect of IFN when intact viral DNA molecules still existed in their nucleus, they could resume viral DNA integration and cell transformation. IFN was found to block viral DNA supercoiling. Since supercoiled viral DNA is considered to be a precursor to integrated provirus, it seems that the inhibition of both integration and cell transformation is due to this impaired coiling.
Analysis of the growth characteristics of a primary BALB/c IgG plasmacytoma
Authors: Hentschel Roland , Kölsch Eckehart 
Published: February 2007

AbstractSpontaneously arising and chemically or virally induced tumors usually cannot be analyzed in the early stages of tumorigenesis. Growth characteristics of these tumors thus are not available and it is unkown whether their expansion at any stage is influenced by the immune system. We have developed the following strategy to evaluate possible deviations from exponential growth in initial stages when a tumor is not yet manifest and in order to overcome the two main objections against most experiments in tumor immunology: use of possibly selected transplantable tumors and high initial cell doses. BALB/c mice received 0.5 ml of Pristane intraperitoneally three times within 16 weeks. This treatment induces plasmacy‐tomas in 58% of the animals within I year. Mice were bled twice a week beginning with the 5th week after the last injection and sera were stored. Guinea‐pig anti‐idiotypic antibodies were raised against the IgG myeloma protein of a plasmacytoma developing in mouse 6‐15 and a radioimmunoassay was set up. Sera of mouse 6‐15 were then tested in retrospect for appearance and increase of the myeloma idiotype Id 6‐15. We followed this idiotype thus for 19 weeks from a concentration of about 10 μg/ml up to 3 mg/ml serum. Plasmacytoma 6‐15 cell growth was calculated from the Id 6‐15 levels. In early phases wave‐like fluctuations were found, possibly due to varying ratios of secretor to total plasmacytoma 6‐15 cells. This phase was followed by an exponential increase in secretor cell number. At no time was there evidence for anti‐idiotypic auto‐antibodies against Id 6‐15. The data are discussed in connection with possibly early activation of cellular components of the immune system.
Homogeneously staining regions and tumorigenicity
Authors: Gilbert Fred , Balaban Gloria , Brangman Deborah , Herrmann Nira , Lister Ann 
Published: February 2007

AbstractA homogeneously staining region (HSR), a chromosome abnormality associated with gene amplification, was found to increase in length coincident with an enhancement in tumorigenicity when cells from a human retinoblastoma cell line were serially passaged in athymic (nu/nu) mice.
Antilymphoma graft responses in the mouse brain: A study oft‐dependent functions
Authors: Puccetti P. , Giampietri A. , Campanile F. , Romani L. , Fioretti M. C. 
Published: February 2007

AbstractThe ability of mouse brain to provide T‐dependent anti‐lymphoma graft responses was studied in a model in which graded numbers of tumor cells were implanted intracerebrally into recipient hosts. By using survival criteria, it was possible to demonstrate the occurrence of both primary and secondary responses against tumor‐associated histocompatibility antigens in allogeneic models as well as tumor‐associated transplantation antigens in histocompatible recipients. The patterns of this in‐tracerebral graft resistance did not differ significantly from those of peripheral T‐dependent immune reactivity. The findings are discussed with regard to the concept of the brain as an immunologically privileged site.
Initiation of focal hyperplastic hepatic lesions by transplacental administration of ethylnitrosourea in rats of F1 generation, and no transmission of the effect to F2 and F3 generations
Authors: Ogawa Katsuhiro , Yokokawa Kinya , Tomoyori Takashi , Narasaki Masanobu 
Published: February 2007

AbstractAdministration of ethylnitrosourea (ENU) to pregnant rats in the late stage of gestation has been known to have a mainly neurocarcinogenic action on the progeny. However, when transplacental administration of ENU was combined in postnatal life with a brief dietary exposure to 2‐acetylaminofluorene (2‐AAF) and a two‐thirds partial hepatectomy, numerous focal hyperplastic lesions of γ‐glutamyltranspeptidase (GGT)‐positive hepatocytes emerged in the liver of the progeny. On the other hand, rats of F2 generation born of F1 parents and F3 rats born of F2 parents showed no increase in the incidence of hepatic lesions after treatment with the same dietary regimen. It was suggested that direct interaction between fetal liver cells and the carcinogen is important for occurrence of initiated hepatocytes and that the initiation effect on rat liver by ENU does not persist in the descendants of F2 and F3 generations.
Persistence of methylated purines in the dna of various rat fetal and maternal tissues and carcinogenesis in the offspring following a single transplacental dose of N‐methyl‐N‐nitrosourea
Authors: Likhachev A. J. , Alexandrov V. A. , Anisimov V. N. , Bespalov V. G. , Korsakov M. V. , Ovsyannikov A. I. , Popovic I. G. , Napalkov N. P. , Tomatis L. 
Published: February 2007

AbstractFormation and loss of methylated purines in DNA of various fetal and maternal tissues were measured up to 7 days following intravenous administration of N‐[14C]methyl‐N‐nitrosourea to rats on the 21st day of gestation. Methylation products were detected in all tissues examined, the level in maternal liver being higher than in other tissues. The concentrations of 7‐methylguanine and 3‐methyladenine decreased faster in fetal than in corresponding maternal tissues, due to a higher rate of DNA synthesis in fetal tissues, as determined by incorporation of labelled thymidine. Removal of the promutagenic DNA lesion O6‐methylguanine was most efficient in maternal and fetal liver; but it was very poorly repaired in kidney and brain. The persistence of O6‐methylguanine relative to 7‐methylguanine was highest in the DNA of fetal brain. The principal targets for the transpacental carcinogenic effect of N‐methyl‐N‐nitrosourea under these experimental conditions were fetal neurogenic tissue and kidney; and malignant tumors developed at these sites in 31‐34% and 15‐16% of male and female descendants, respectively. These results support the concept that a complex interaction between DNA alkylation, repair and replication is the molecular basis of initiation of carcinogenesis by alkylating agents.
Neoplastic transformation of fetal lamb kidney cells by bovine leukemia virus
Authors: Rhim Johng S. , Kraus Matthias , Arnstein Paul 
Published: February 2007

AbstractNeoplastic transformation of fetal lamb kidney (FLK) cells by bovine leukemia virus (BLV) is reported. Morphological transformation was observed in FLK cells within a few weeks of BLV inoculation. BLV‐transformed FLK cells had the following properties generally associated with viral transformation: (1) altered morphology; (2) increased growth rate; (3) colony formation in soft agar medium; (4) formation of large cell aggregates and growth in this aggregate form above an agar base; and (5) tumorigenicity in nude mice. The transformed cells contained BLV‐specific p24 and gp51 antigens and were virus producers. BLV was detected in transformed cells by syncytial assay. The transformed cells yielded high‐titered viral reverse transcriptase activity and viral particles. The transformed cells contained marker chromosomes (M1, M<2>, M<3>, M4 and M7) and a large submetacentric chromosome, but control cells did not. Thus, we demonstrated the neoplastic transformation of FLK cells by BLV.
Cytotoxic action of prostaglandin D2 on mouse neuroblastoma cells
Authors: Higashida Haruhiro , Kano‐Tanaka Kyoko , Natsuume‐Sakai Shunnosuke , Sudo Katsuko , Fukami Hiroko , Nakagawa Yuzo , Miki Naomasa 
Published: February 2007

AbstractAddition to the culture medium of prostaglandin (PG) D2 resulted in the degeneration in a dose‐ and time‐dependent manner of NI8TG‐2 cells cloned from mouse neuroblastoma. The ED50 for PGD2‐induced cytotoxicity was about 10 μM. The degenerative changes were irreversible when the cells were exposed for more than 10 h. Scanning and transmission electron microscopic examination revealed that treatment with PGD2 resulted in apearance of numerous blebs of various sizes along the cell surface and also in destruction of surface membrane and of cytoplasmic organelles. Tumor weight of NI8TG‐2 neuroblastoma inoculated subcutaneously on the backs of A/J mice was about 35‐70% less than that of controls after 14 days of single daily i.p. or s.c. injections of 0.5‐1 mg/kg of PGD2. The results indicate that PGD2 has growth‐inhibitory effects on mouse neuroblastoma cells in vitro and in vivo.
Detection of different states of immunity to colon cancer in rats by a leukocyte adherence inhibition (LAI) assay assessing the adherence of T lymphocytes and monocytes selectively
Authors: Morizane Toshio , Sjögren Hans Olov 
Published: February 2007

AbstractPeripheral blood mononuclear cells (MNC) of rats, which had received a subcutaneous inoculation of either viable or X‐irradiated syngeneic DMH‐W49 colon carcinoma cells, were investigated sequentially for sensitization against tumor‐associated antigens by a new micro‐glass‐tube leukocyte adherence inhibition (LAI) assay. The number of adherent cells of MNC subpopulations was estimated by a cellular radioimmunoassay (CRIA), which utilizes anti‐monocyte (MC) antiserum or anti‐T‐cell monoclonal antibody (McAb) and 125I‐labelled protein A. LAI reactivity was demonstrated in rats sensitized with X‐irradiated tumor cells when assessing the adherence of both T lymphocytes and monocytes. It was found that reactivity with the two different types of indicator cells did not usually coincide in time. The same phenomenon was also observed in tumor‐bearing rats although with lower levels of LAI reactivity. In both groups the LAI response detected by anti‐T‐cell reagent mostly appeared earlier after tumor‐cell inoculation than the response demonstrated by anti‐MC serum. The T‐lymphocyte‐associated reactivity also disappeared more rapidly. These results suggest that different states of immune reactivity are reflected in LAI responses involving T lymphocytes and monocytes as indicator cells.
International variations and temporal trends in mortality from multiple myeloma
Authors: Cuzick Jack , Velez Ramon , Doll Richard 
Published: February 2007

AbstractMortality statistics for multiple myeloma over the period 1960–1975 have been analysed for 23 countries. Attention has been focused on international variations, secular trends, and the male to female mortality ratio. The greatest percentage increases have been found in countries with low overall rates. The male:female ratio was generally higher in countries with high rates, and the national rates correlated more strongly with GNP per caput than with an index of medical care (hospital beds/10,000). Further analyses have been carried out over the period 1955–79 in Sweden, a country with high but relatively stable rates, and Japan, where the rates are very low but are increasing rapidly. An age, period, and cohort analysis of the trends in these countries is presented and criticized. The contributions made by increased diagnostic capability and by an increase in the true incidence of the disease are discussed.
Expression of Thy‐1 antigen on human melanoma cells
Authors: Hersey P. , Grace Julienne , Murray Elaine , Palmer A. , McCarthy W. H. 
Published: February 2007

AbstractThe expression of Thy‐1 was examined on fresh frozen sections of melanoma and control skin lesions using a monoclonal antibody to Thy‐1 and immunoperoxidase‐labelled second antibodies. Thy‐1 was detected on 12 of 19 primary melanomas but on only 1 of 23 melanoma metastases in lymph nodes, skin or brain. Expression of Thy‐1 did not appear related to other known histological features of primary melanoma. Thy‐1 was also expressed on 2 of 7 naevi but not on normal melanocytes or carcinoma of squamous cells, basal cells and sweat glands of the skin. Some lymphocytes below primary melanomas were Thy‐1 positive. These results suggest that Thy‐1 may be a marker of melanocytes at certain stages of differentiation analogous to its expression on cell lineages in the haemopoietic system. The relative paucity of Thy‐1 on metastases may indicate that its expression on melanoma cells has prognostic significance for behaviour of the tumour in its host.
Among the human antibodies reacting with intracytoplasmic a particles of mouse mammary tumor virus, some react with MMTV p14, the nucleic‐acid‐binding protein, and others with MMTV p28, the main core protein
Authors: Zotter Stefan , Grossmann Heinz , François Camille , Kozma Sara , Hainaut Pierre , Calberg‐Bacq Claire‐Michelle , Osterrieth Paul M. 
Published: February 2007

AbstractHuman IgG antibodies reacting in the indirect immunofluorescence test with clusters of intracytoplasmic A particles in mouse tissues were analyzed by means of both radioimmunoprecipitation and enzyme‐linked immuno‐absorbant assays. Generally, antibody‐containing sera reacted with epitopes of p14, the nucleic‐acid‐binding core protein of mouse mammary tumor virus, corresponding to the protein Ap14 of intracytoplasmic A particles. Comparatively few sera reacted with epitopes of the main core protein p28 corresponding to the protein Ap28 of intracytoplasmic A particles. The two types of reactivity occurred independently of each other.
Correlation of drug sensitivity on human colon adenocarcinoma cells grown in soft agar and in athymic mice
Authors: Zirvi Karimullah A. , Masui Hideo , Giuliani Fernando C. , Kaplan Nathan O. 
Published: February 2007

AbstractA well‐differentiated colorectal tumor T 219 which grows as a xenograft in athymic mice (human‐tumor‐nude‐mouse system) and forms colonies in culture (soft agar colony‐formation assay) has been used to test the correlation between the above two methods of exposure of human tumor cells to antineoplastic agents. In in vitro studies, two protocols were used: I h drug exposure and continuous drug exposure. In the I h drug exposure experiments six drugs, doxorubicin (DX), 4′‐deoxydoxorubicin (deoDX), 4′epidoxorubicin (epiDX), 4′‐O‐methyldoxorubicin (O‐DX), N‐trifluoroacetyldoxorubicin‐14‐valerate (AD‐32) and 5‐fluorouracil (FUra) were studied, while in continuous drug exposure experiments four of the above drugs (DX, deoDX, epiDX, O‐DX) were studied. The survival of the tumor clonogenic cells (HC219) was determined by counting the number of colonies formed during 13–14 days of incubation and dose‐response curves were obtained. In in vivostudies, the mice were treated with all of the drugs used in in vitro I h drug exposure experiments (DX, deoDX, epiDX, O‐DX, AD‐32 and FUra). To quantitate the chemotherapeutic effectiveness of the drugs, T/C% (relative tumor volume of treated group as percentage of the control group) values were calculated each time the tumors were measured. The experimental data suggest that in vitro I h drug exposure results are in good agreement with the in vivo results, while the continuous drug exposure results do not agree with the in vivo data. The most active drug in in vivo studies, deoDX, was found to be the most active drug in the in vitro I h drug exposure experiments as well. However, in continuous drug exposure experiments, O‐DX, not deoDX, was found to be the most active drug. Activities of the other drugs tested also differed from their respective activities in in vivo studies. Although the relative effectiveness of various drugs can be compared by determining molar concentrations of the drugs producing 50% inhibition of colonies (ID50) the expression, PEI = LD10/ID50 × 1000, which takes into consideration toxicity of the drugs, is probably a better indicator of the in vitro drug activity. The results suggest that soft agar colony‐formation assay (with established cell lines from the same tumor) may be used for the prediction of in vivo activity of potential antineoplastic agents against human tumor xenografts in nude mice.
Differential cytotoxicity of tumour promoter TPA for EBV‐negative human lymphoma cell lines and their EBV‐converted sublines
Authors: Béchet Jean‐Marie , Guétard Denise 
Published: February 2007

AbstractThe tumour‐promoting phorbol diester 12‐O‐tetradecanoyl‐phorbol‐13‐acetate (TPA) is toxic at nanomolar concentrations for Epstein‐Barr virus (EBV)‐negative human lymphoma cell lines BJAB and Ramos. Sublines that have been converted to Epstein‐Barr nuclear antigen (EBNA)‐positivity by infection with EBV survive and grow in TPA concentrations that are lethal for their non‐converted parental lines. Resistance to the growth‐inhibiting effect of TPA is higher in sublines of BJAB and Ramos that have been converted by the transforming B95‐8 strain of EBV than in those converted by the non‐transforming P3‐HRI strain. The loss of TPA‐sensitivity may reflect a change in the transformation or differentiation state of lymphoma cells as a result of EBV‐conversion.
Plasminogen activator activity of metastatic variants from a murine fibrosarcoma; effect of thrombin in vitro
Authors: Coen Daniele , Bottazzi Barbara , Bini Alessandra , Conforti Maria Grazia , Mantovani Alberto , Mussoni Luciana , Donati Maria Benedetta 
Published: February 2007

AbstractIn order to investigate the possible correlation between plasminogen activator (PA) activity and metastatic potential of tumour cells, we studied cultured cells from the murine fibrosarcoma mFS6 and from its two sublines M4 and M9 which differ markedly in their capacity to cause spontaneous metastases in the lung. PA activity was detected in all the sublines by an amidolytic method and was almost completely inhibited by treatment with anti‐urokinase antiserum. No significant differences were shown between mFS6, M4 and M9. Moreover, molecular analysis of PA by SDS‐PAGE electrophoresis and fibrin overlay revealed in all the cell types a single species having a mol. wt. of approximately 48,000 daltons. Thrombin treatment dramatically inhibited the amidolytic activity of all cells, suggesting a role for this enzyme in the modulation of fibrin formation and dissolution within the primary neoplasm.