bluuebunny/crossref_metadata_2025_split huggingface dataset:
Subpopulations of multiparous rat lymph‐node cells cytotoxic for rat tumour cells and capable of suppressing cytotoxicity in vitro
Authors: Rees R. C. , Bray Judith , Robins R. A. , Baldwin R. W. 
Published: February 2007

AbstractLymph‐node cells (LNC) from multiparous pregnant rats were separated on columns prepared from nylon wool, and tested for cytotoxicity against target tumour cells. Reactivity of LNC towards hepatoma D23 and mammary carcinoma AAF57 was demonstrated in cell populations retained on the nylon wool, and not with cells eluted from the column. Although only 25% of the samples of unfractionated LNC were cytotoxic for tumour cells, retained cell fractions were cytotoxic in 11 out of 12 tests (p = <0.05). Similarly retained LNC were also cytotoxic for 15‐day‐old embryo cells but not for normal adult rat fibroblasts. Using multiparous rat serum it was shown that the reactivity of the retained LNC population could be abrogated in eight out of 11 tests (p = <0.05). The LNC population recovered from the nylon wool constituted 28 to 35% of the original LNC preparation, and consisted of 60–70% Ig‐bearing cells together with a subpopulation of cells responding to soluble PHA. Separation of multiparous LNC on glass beads coated with rat Ig and then rabbit anti‐rat Ig (in excess) also demonstrated the retained cell population to be cytotoxic against tumour cells. Approximately 17–20% of the original cell population was recovered from cells retained on the column, and consisted of an enriched Ig‐bearing cell population (65–80% Ig‐bearing cells) and LNC responsive to PHA. Carbonyl iron treatment of multiparous rat LNC was found to remove detectable cytotoxicity from multiparous rat LNC preparations. The cytotoxicity of multiparous rat LNC retained on nylon wool was also abolished following incubation with carbonyl iron. Definite conclusions as to the nature of the effector cell cannot be drawn from this test, since carbonyl iron treatment was found to remove not only phagocytic cells from LNC preparations but also a proportion of other cell populations including Ig‐bearing lymphocytes. In addition to detecting a cytotoxic LNC population reactive towards tumour‐associated embryonic antigens (retained fraction from nylon‐wool column separation), a subpopulation of multiparous rat LNC was demonstrated in cell fractions eluted from the nylon wool which was shown to suppress the cytotoxicity of the retained multiparous LNC population. The exact nature of this subpopulation of LNC and the mechanism of action is at present not known.
Studies on the uptake of 2‐deoxy‐d‐glucose in normal and malignant rat epithelial liver cells in culture
Authors: Siddiqi Maqsood , Iype P. Thomas 
Published: February 2007

AbstractThe rate of uptake of 2‐deoxyglucose in normal rat hepatic cells and chemically induced hepatoma cells in culture was studied. The hepatoma cells possessed a higher permeability to the sugar at all stages of culture. However, a decrease in the uptake of 2‐deoxyglucose at confluency was observed in cells which exhibited density‐dependent inhibition of growth, whether normal or malignant. The normal cells in mitosis showed an increased permeability to the sugar, whereas no such change was observed in the hepatoma cells. The kinetic studies of 2‐deoxyglucose transport in normal and transformed rat liver showed a positive correlation between the increase in Vmax and the transformed state of the cells, whether they were transformed in vitro or in vivo. No changes in the apparent Km were found, indicating that there are no qualitative changes in the transport sites. The results suggest that an increase in the number of sites involved in glucose transport is a characteristic of chemically transformed rat liver epithelial cells.
Epidemiological studies on feline leukaemia virus infection. I. A serological survey in urban cats
Authors: Rogerson Petrina , Jarrett William , Mackey Lindsay 
Published: February 2007

AbstractA survey of the incidence of feline leukaemia virus (FeLV) infection in cats in a large urban area was made by studying the prevalence of antibodies to feline leukaemia virus‐associated cell membrane antigens. Two serological tests were used, immunofluorescence and a mixed immunoglobulin rosette technique. The overall incidence of cats with antibodies was 40%, contrasting with 6% in the surrounding rural area. Only 6% of urban kittens were positive while 50% of adults had antibodies. The incidence in adults rose from 29% at 5–6 months to 74% in cats over 3 years. Stray cats had an incidence twice as high as that of domestic pets. These results support and extend earlier findings that FeLV infection is common and is horizontally transmitted.
Inhibition of human leukocyte migration in agarose by KCl extracts of carcinoma of the lung
Authors: Boddie A. W. , Holmes E. Carmack , Roth Jack A. , Morton Donald L. 
Published: February 2007

AbstractThe leukocyte migration in agarose assay recently developed by Clausen (Clausen, 1971), was used to test 22 lung cancer patients against soluble extracts of allogeneic lung cancer and allogeneic normal lung. Seventeen were inhibited to a significantly greater degree by at least one tumor extract (average migration index MI = 0.58) than by the corresponding normal lung extract (average MI = 0.83). DNCB‐positive and DNCB‐negative patients reacted with equal frequency to tumor extracts. Three patients tested against their autologous tumor and normal lung extracts were specifically inhibited by the tumor extract (average MI = 0.53) but not by the normal lung extract (average MI = 0.83). None of seven lung cancer patients tested against non‐pulmonary tumor extracts was significantly inhibited (average MI = 1.1). Only 6/53 controls including patients with other tumors, patients with emphysema and age‐matched non‐smokers showed significant inhibition against any of the lung cancer extracts. These findings strongly suggest the presence of tumor‐associated antigens in KCl‐solubilized extracts of human lung cancer.
Induction of malignant lymphomas in swiss mice by N‐nitroso compounds formed in vivo
Authors: Börzsönyi Mátyás , Csik Márta 
Published: February 2007

AbstractMalignant lymphomas were induced in Swiss mice treated intragastrically with methyl‐2‐benzimidazole carbamate (MBC, BCM, Carbendazim) and given sodium nitrite in their drinking water. The tumours appeared between 82 and 164 days after the beginning of treatment. In 30 mice given MBC and sodium nitrite, 10 lymphosarcomas were found. In the proliferating tumour cells, intracytoplasmic type‐A virus particles were demonstrated by electron microscopy. No tumours were found in animals given MBC only. The findings demonstrate the possibility of in vivo formation of N‐nitroso derivatives from MBC.
Are methylcholanthrene‐induced sarcoma‐associated, rejection‐inducing (TSTA) antigens, modified forms of H‐2 or linked determinants?
Authors: Klein George , Klein Eva 
Published: February 2007

AbstractTA3Ha/MSWBS hybrid cells have been derived from the fusion of the TA3Ha ascites carcinoma (H‐2a) and the methylcholanthrene‐induced MSWBS ascites sarcoma (H‐2s). MSWBS expresses a strong tumor‐specific transplantation antigen (TSTA), capable of inducing a rejection reaction in the syngeneic A.SW host. The genetic determinants of the H‐2 complex are known to be localized on chromosome No. 17. TA3Ha contributes two normal, telocentric chromosomes No. 17 to the hybrid. In contrast, both chromosomes No. 17 of MSWBS are localized on readily identifiable translocations (17/1 and 17/M1; see Wiener et al., 1974). We have previously shown that the chromosomes No. 17 of one parental strain, or the other (but not both) can be removed from the hybrid by selective passage in the opposite parental strain. The present paper examined the possibility, often suggested in the literature, that the MC‐sarcoma‐associated TSTA could be a modified form of H‐2. MSWBS, unselected TA3Ha/MSWBS and YACIR/MSWBS hybrids were compared with TA3Ha/MSWBS‐derived isoantigen loss variants, with regard to their immunogenicity in the TSTA test, i.e. their ability to induce rejection of MSWBS target cells in ASW mice. Whereas the unselected hybrids were as immunogenic as the parental MSWBS line itself, two strain A compatible and two strain A.SW compatible variants which had lost chromosome No. 17 of the opposite strain showed a residual, but clearly weakened immunogenicity. Since there was no systematic difference between the reciprocal types, it is concluded that the genetic determinant of TSTA is not localized on the chromosome No. 17 but that a proper balance of this chromosome is required for the full expression of immunogenicity in the TSTA system.
The nature of the deoxyribonucleosides involved in the binding of carcinogenic hydrocarbons to the DNA of mouse embryo cells
Authors: Brookes P. , Jones Pamela , Amos Jacqueline 
Published: February 2007

AbstractThe DNA of mouse embryo cells was specifically labelled in the purine moieties with (G3H)‐deoxyadenosine or in the cytosine moieties with (53H)‐deoxycytidine. These cells were then treated with 7‐methylbenz (a) anthracene (7MBA) or benzo (a)‐pyrene (B(a)P) and the DNA isolated, degraded and fractionated by LH20 Sephadex column chromatography. When the purines of the DNA were tritium‐labelled, radioactive hydrocarbondeoxyribonucleoside products were obtained. No such products were found with deoxycytidine pre‐labelled DNA. Contrary to an earlier suggestion, these results indicate that it is the purine moieties of DNA which react with the metabolically activated hydrocarbon derivative in vivo.
Risk indicators in childhood malignancies
Authors: Salonen Tuula , Saxén Lauri 
Published: February 2007

AbstractA series of 972 childhood malignancies was compared with a control series of healthy children matched for date and place of birth. Several variables were tested for possible aetiological significance. The information was obtained from the Finnish Cancer Registry and from the antenatal records of the mothers. No significant associations were found between the various types of malignancies and the variables studied. In the group consisting of all malignancies, a risk ratio of 2.0 could be significantly excluded for most variables. In the leukaemia group, both pelvic X‐ray and polio vaccination were associated with slightly elevated risk ratios, but the differences between this group and the matched controls were not statistically significant. BCG vaccination was performed during the perinatal period in 90% of the children, but the proportion was the same in the study and control groups, and hence the hypothesis that this vaccination confers protection was not supported. The information is considered prospective and relatively reliable, and the authors suggest that these data may be useful when more extensive series are compiled from various sources.
Lack of correlation between growth characteristics, agglutinability by plant lectins and the malignant phenotype
Authors: Berman Leonard D. 
Published: February 2007

AbstractWheat germ agglutinin and Concanavalin A were found to agglutinate a variety of normal hamster cells as well as a number of lines of transformed or tumor cells. The normal cells included preparations from embryos and neonatal organs, and the spontaneous line, BHK‐21 C13. In order to explore more fully the situation in regard to the BHK cells, three sublines were isolated and studied. A “flat revertant” selected by FUdR treatment grew to diminished saturation density and failed to produce colonies in soft agar in contrast to the parent line, which did. Yet, it was only minimally less tumorigenic and less agglutinable than the parent line. Lines derived from one and four consecutive in vivo tumor passages showed increased tumorigenicity and growth in soft agar when compared to the parent line. Although the first passage line showed increased saturation density, the saturation density of the fourth passage line was similar to or less than that of the parent cells. Agglutinability of these lines was not significantly increased. These results indicate that, in contrast to widely accepted beliefs, tumorigenicity may correlate poorly with growth characteristics and agglutination by plant lectins.
Chromosome banding anomalies in acute myeloid leukaemia
Authors: Fleischmann Tamás , Bodor Ferenc 
Published: February 2007

AbstractChromosome analysis in two cases of acute myeloid leukaemia are reported. On the basis of slight aberrations in the banding pattern marker chromosomes were observed in both cases. In one case a widened C‐band of an additional D chromosome, and in the other case an unusual negative fluorescent band below the centromere of one of the chromosomes 16, were seen.
Detection in colorectal carcinoma patients of antibody cytotoxic to established cell strains derived from carcinoma of the human colon and rectum
Authors: Schultz Richard M. , Woods Wilna A. , Chirigos Michael A. 
Published: February 2007

AbstractSera from eight of 15 patients with colonic carcinoma exhibited demonstrable cytotoxicity against an established cell strain derived from adenocarcinoma of the ileocecum, HCT‐8. Sera from 12 of 16 patients with rectal carcinoma were cytotoxic for an established cell strain derived from an adenocarcinoma of the rectum, HRT‐18. Patients with colonic carcinoma exhibited serum cytotoxicity against only the colonic target cells, whereas patients with rectal carcinoma gave significant cytotoxicity against both cell strains. This cytotoxicity was shown to be complement‐dependent and appeared to be specific for colonic and/or rectal carcinoma cells. Although the cells produced carcinoembryonic antigen (CEA) in vitro, the cytotoxic antibody response in these patients did not appear to be directed against CEA. Serum cytotoxicity was not demonstrated against two other cell strains, HCT‐48 and HT‐29, derived from adenocarcinomas of the human colon, except for a reaction against a blood‐group‐related antigen. These cell strains had comparable levels of cell‐associated CEA. The routine titration of cytotoxic antibody against these established cell cultures may provide meaningful information on the host's immune response to colorectal neoplasms.
Microscopical cancer of the stomach — a study on histogenesis of gastric carcinoma
Authors: Nagayo Takeo 
Published: February 2007

AbstractIn order to elucidate the histogenesis of gastric cancer preceded by “chronic gastritis”, 67 foci (58 cases) of minute cancer less than 5 mm in largest diameter were examined histologically. The results obtained were as follows. (1) Except in two cases, all minute cancerous foci were found unexpectedly in the mucosa of the antrum or of the angulus having peptic ulcer or gastric cancer. They were more frequent in the lesser curvature than in other parts of the stomach. (2) Histologically, 18 foci were found in an area close to the main lesion, while 40 were far from the lesion. Seven foci were detected in the mucosa adjacent to ulcer scars. (3) In retrospective macroscopical examinations, 41 foci showed minimal erosion or tiny depressions on the affected mucosa, while in the other 26 no recognizable changes were observable. (4) Histologically, the gastric mucosa outside the cancer lesions was more or less atrophic with or without intestinal metaplasia. (5) Regardless of histological types, all the minute cancers were found in the transitional zone between foveolar epithelium and pyloric glands corresponding to “generative cell layer” in autoradiographic studies. (6) Poorly differentiated adenocarcinomas containing signet‐ring cells occurred most often in combination with no or slight intestinal metaplasia of the mucosa, while well‐differentiated adenocarcinomas were always found in ventricles with severe intestinal metaplasia.
Inactivation of the dna template in HeLa cells treated with chlorambucil
Authors: Roberts J. J. 
Published: February 2007

AbstractThe effect of chlorambucil on the colony‐forming ability of HeLa cells following either treatment for 1 h or continuous treatment has been measured. Concentrations of chlorambucil which had only minimal effects on cell survival inhibited the rate of DNA but not RNA and protein synthesis within 1 h of treatment. Nevertheless, cells continued to synthesize DNA for many hours after this treatment in the absence of cell division. Synchronous populations of HeLa cells treated prior to DNA synthesis, in the G1 phase of the cell cycle, were not delayed in their progression into the S phase where they exhibited a marked dose‐dependent inhibition of the rate of DNA synthesis. Cells in which DNA synthesis had been depressed showed a prolongation of the S phase and this was accompanied by a corresponding dose‐dependent mitotic delay. Treatment during the G2 phase of the cell cycle did not induce any delay or block in the next mitosis, but did inhibit the rate of DNA synthesis in the following cell cycle in a dosedependent manner; this depression of DNA synthesis was followed by a delay in the next mitosis. Cross‐linking of either isolated DNA or DNA present in treated HeLa cells was demonstrated, and in the latter case calculated to be of the same order as that which occurred with other difunctional agents at comparable toxic concentrations.
Vaccination against feline leukaemia virus using a cell membrane antigen system
Authors: Jarrett William , Jarrett Oswald , MacKey Lindsay , Laird Helen , Hood Christine , Hay David 
Published: February 2007

AbstractCats inoculated with live feline lymphoblastoid cells of the FL74 line developed high titres of antibody to feline oncornavirus‐associated cell membrane antigen (FOCMA). Eight cats were subsequently challenged with a large dose of feline leukaemia virus (FeLV) of a highly pathogenic strain. All resisted infection while 10 cats given the challenge virus alone became infected. The FeLV produced by FL74 cells was shown to be of extremely low infectivity in cats and in cultured feline cells. Cats inoculated with either FL74 cells or virus purified from them did not become infected. The purified virus did not induce FOCMA antibody in cats not previously exposed to FeLV. The fact that FL74 cells are highly immunogenic, but produce virus of low infectivity, is of value in devising vaccines against FeLV. Cats were also inoculated with FL74 cells which had been inactivated with paraformaldehyde. They developed FOCMA antibody, reaching a peak titre of 256, and no virus could be cultured either from the vaccine preparations or from the tissues of the cats.
Comparison of 51Cr release and microcytotoxicity assays against human melanoma cells
Authors: Hersey P. , Edwards J. , Edwards A. , Adams E. , Kearney R. , Milton G. W. 
Published: February 2007

AbstractComparisons of the cytotoxic activity of mononuclear cells from venous blood of human subjects against human melanoma cell lines have been made by means of the 51CV release assay (CRA) and the microcytotoxicity assay (MCA) of Takasugi and Klein. The relative effectiveness of the two assays in the detection of killing by various sub‐populations of effector cells was studied after depletion of monocytes and separation of the blood monocluear cells by SRBC receptor and Fc receptor rosetting techniques. Overall, the results showed good correlation. Most differences were the result of low values recorded with the CRA when effector cells were obtained from Hypaque‐Ficoll—separated populations which had not been further fractionated. These differences were largely removed when monocytes were depleted by glass absorption and may reflect interference with the CRA by monocytes. No consistent differences were found between the assays in the detection of killing by subfractions enriched for T cells or B cells in this tumour system. The MCA appears to offer the advantage of greater sensitivity and possibly detection of a wider range of cytotoxic mechanisms but the CRA has a number of advantages of a technical nature which make it more applicable to routine assays in clinical studies.
Specificity of cell‐mediated cytotoxicity against human melanoma lines: Evidence for “non‐specific” killing by activated T‐cells
Authors: Hersey P. , Edwards A. , Edwards J. , Adams E. , Milton G. W. , Nelson D. S. 
Published: February 2007

AbstractThe specificity of cell‐mediated cytotoxicity against melanoma cells in vitro has been analyzed in a large number of studies with cells both from normal and melanoma subjects. As in a number of other, recent, similar human studies, no evidence for tumour specificity was found. Effector cells in peripheral blood responsible for the cytotoxic reaction were examined by cell separation methods based on red cell rosette formation and separation through Hypaque‐Ficoll mixtures. The evidence suggests that nonspecificity results from killing by cells separating largely in the non‐sheep red blood cell rosetting fraction and which have cytotoxic specificity directed broadly to cells with abnormal membranes. Further analysis revealed that the cells were non‐phagocytic and did not bear receptors for complement. They appear to be activated into cell division and to bear surface receptors for the Fc portion ofIgG. Additional evidence is presented suggesting that the cells mainly responsible are activated thymus‐dependent cells present in the circulation of both tumour‐bearing and normal subjects.
Early alterations in plasma esterases with associated pathology following oral administration of diethylnitrosamine and butylated hydroxytoluene singly or in combination
Authors: Tyndall R. L. , Colyer S. , Clapp N. 
Published: February 2007

AbstractPlasma esterase changes are apparent in BALB/c mice within 3 weeks after feeding them laboratory chow with 0.75% of the antioxidant BHT added. Other esterase changes, different from those in BHT‐treated animals, are also apparent in plasma of mice during exposure to the carcinogen DENA. Interference with these DENA esterase alterations is apparent in plasma of mice treated concomitantly with both DENA and BHT. Esterase changes resulting from either the carcinogen or antioxidant exposure precede the overt histologically detected changes induced by these compounds. The early esterase changes and subsequent tumorigenesis resulting from DENA exposure are more severe in female mice. Some of the esterases altered by DENA or BHT exposure are testosteronerelated.
A fetuin‐like antigen from human nephroblastoma
Authors: Wise K. S. , Allerton S. E. , Trump G. , Powars D. , Beierle J. W. 
Published: February 2007

AbstractAn antigen was detected in pooled human nephroblastomas using antiserum prepared in rabbits against an ethylenediaminetetra acetic acid (EDTA) extract of the tumors. This antigen was not found in normal human plasma or kidney extracts, and was not related to the ABO or Forssman blood groups. The antigen was detected in extracts of cultured nephroblastoma cells, but was not present in extracts of normal human fetal kidney cell cultures. The antigen is believed to be present at the cell surface, as cell viability was not significantly lowered during the extraction procedure. A reaction of complete identity was demonstrated by Ouchterlony double diffusion experiments with this antigen and purified bovine fetuin. The antigen was not found in extracts of human fetal spleen, thymus or kidney, nor in human fetal serum. Furthermore, the antigen does not possess determinants in common with the human alpha‐fetoprotein of hepatomas, nor was it detected in human renal clear cell carcinoma. Initial characterization of the antigen showed it to be nondialysable, not sedimentable at 100,000 × g for 2 h, stable to repeated freeze‐thawing and to incubation at 56° C for 1 h, and water soluble over a wide ph range. The antigen was susceptible to digestion with pronase and trypsin and possibly hyaluronidase, but not to ribonuclease or neuraminidase. The protein portion is therefore of major importance to the structural integrity of this antigen. The relationship between this antigen and other abnormal materials reported previously in nephroblastoma patients is being studied.