bluuebunny/crossref_metadata_2025_split huggingface dataset:
TRANSITORY CELL ANTIGENS OF RAT LIVER. III. THE REAPPEARANCE OF α‐FETOPROTEIN DURING CHEMICAL CARCINOGENESIS
Authors: De Et B. Néchaud , Uriel J. 
Published: February 2007

AbstractWhen rats were fed a basal diet containing 0.01 to 0.04% 3′‐methyl‐4‐dimethyl‐aminoazobenzene (3′DAB), no serum α‐fetoprotein (αFP) was detected by gel immunodiffusion techniques during the first month of ingestion. On the contrary, with 0.06% 3′DAB in the same basal diet, α‐FP was detected after only two weeks in the sera of almost all animals, irrespective of age at the onset of feeding. An even earlier “reappearance” of α‐FP was observed with the hepatocarcinogen dimethylnitrosamine, given in drinking water. However, the frequency of α‐FP reappearance was dependent on the age of the animals when treatment was begun. Once detected, the α‐FP persisted in the blood for some time and was independent on the continued administration of carcinogen. The reappearance was characterized by several waves of α‐FP secretion over a given period. Animals whose serum α‐FP level became stabilized had a high probability of developing an hepatocellular carcinoma. Nevertheless, in 30% of hepatoma bearing animals, α‐FP could not be detected. Administration of the basal diet either alone or supplemented with 0.06% of the non‐carcinogenic 4′‐methyl‐4‐dimethylamino‐azobenzene also resulted in α‐FP reappearance. However, here the reappearance took place later and at a frequency equal to or lower than 30%. In the light of the above results, the reported specificity of the association between serum α‐FP and primary liver cancer should be reconsidered, at least during the early stages of the neoplastic transformation.
Destruction of cultivated melanoma cells by lymphocytes from healthy black (North American Negro) donors
Authors: Hellström I. , Hellström K. E. , Sjögren H. O. , Warner G. A. 
Published: February 2007

AbstractPeripheral blood lymphocytes from healthy Black (North American Negro) donors were found to be cytotoxic to cultivated malignant melanoma cells (7 out of 9 tested), but not to tumor cells of other types or to normal skin fibroblasts, in experiments using lymphocytes from normal White donors and from White patients with other types of tumor as controls. Lymphocytes from normal Blacks thus behaved similarly to lymphocytes from patients having melanomas. The cytotoxic effect could be blocked by sera from patients with progressively growing melanomas. Sera from some healthy Black donors could abrogate (“unblock”) the blocking effect of sera from patients with growing melanomas (four out of four tested).
Effect of 3‐methylcholanthrene and dimethylnitrosamine on anchorage dependence of rat fibroblasts chronically infected with rauscher leukemia virus
Authors: Mishra Nirmal K. , Ryan Wayne L. 
Published: February 2007

AbstractThis report describes the loss of anchorage dependence (AD–) after treatment with 3‐methylcholanthrene or dimethylnitrosamine in rat embryo fibroblasts which normally exhibit anchorage dependence (AD+). The AD+ fibroblasts which were chronically infected with Rauscher leukemia virus showed the highest frequency of transformation to AD– cells with chemical carcinogen treatment. A small percentage of AD– cells also appear in uninfected control cells treated with dimethylnitrosamine or at much higher frequency with 3‐methylcholanthrene. The virally infected cells also showed a detectable level of transformation to AD– cells without added chemicals. However, the combined effects of Rauscher leukemia virus infection and chemical carcinogen treatment were much greater than the additive effect of the two. No clear correlation between AD– transformation and the ability to grow in factor‐free medium was found. The significance of these observations is discussed in relation to the “oncogene” hypothesis.
Effects of BCG on various facets of the immune response against polyoma tumors in rats
Authors: Bansal S. C. , Sjögren H. O. 
Published: February 2007

AbstractAdministration of BCG at the time of rat polyoma tumor isografting or 2 weeks previously, inhibited tumor growth and induced an increased level of lymphocyte cytotoxicity and an increase in the number of circulating lymphocytes, i.e. it resulted in an increased level of cell‐mediated immunity. A similar inoculation of BCG at the time when the tumor isograft had already grown out to a palpable nodule did not inhibit tumor growth, but rather caused an enhanced growth. It did not increase the level of cell‐mediated immunity under these conditions and did not decrease the blocking activity in serum, but rather increased it. Furthermore, it did not induce any production of cytotoxic antibodies detectable with rat complement. BCG treatment of rats which had the same day undergone incomplete tumor excision increased the growth of remaining tumor and increased the blocking activity in serum. On the other hand, BCG treatment of analogous rats which had received “unblocking treatment” in the form of splenectomy and inoculation of unblocking serum caused tumor regression in some animals and increased the cell‐mediated immunity in all animals tested.
Expression of tumorigenic potential in isologous hybrid clones of chinese hamster cells
Authors: Blanchard M. G. , Barski G. , Léon B. , Hémon D. 
Published: February 2007

AbstractKaryotypes and phenotypic characteristics of several clones, developed from a wild population of somatic hybrids obtained by crossing two Chinese Hamster cell lines, were analysed in detail. The crossed cell lines were: (1) the DC‐3F, sensitive to Actinomycin D (AD) and highly tumorigenic when checked by inoculation into the Syrian Hamster cheek pouch, (2) the DC‐3F/AD/Aza, resistant to AD and non tumorigenic. In the 6 clonal lines and their 3 derivatives, obtained secondarily from tumors, the resistance to AD was mostly associated with low or even entirely non‐expressed tumorigenic properties, whereas sensitivity to the toxic action of AD was, as a rule, linked with high malignancy. For all the studied clonal and derived lines a general tendency for chromosomal deletion from the “ideal”, complete integration of the two parental karyotypes, was observed. This deletion was frequently, but not always, more accentuated following passage through the animal and production of tumors. The relatively stable aspect of the Chinese Hamster karyotype, with most of the chromosomes easily identifiable, permitted a detailed analysis of the frequency of presence or deletion in the 8 pairs and groups of autosomes, the × and the M1 abnormal marker chromosomes. This analysis has shown that, in general, a preferential deletion occurred in the chromosomes Nos. 2, 4, 5, X, and M1. However, no link existed between the frequency of these individualized chromosomal deletions and either the malignancy or the resistance to AD of the hybrid clones.
The effect of splenectomy on fibrosarcoma “metastases” in lungs of mice
Authors: Milas Luka , Mujagic Hamza 
Published: February 2007

AbstractCells of a methylcholanthrene‐induced fibrosarcoma, injected intravenously into syngeneic C57Bl mice, generated tumour nodules (“metastases”) in the lungs. The number of tumour nodules was reduced in recipients whose spleens had been previously removed. This effect of splenectomy was specific (thymectomy did not affect the number of pulmonary metastases), and was greater if fewer tumour cells were injected. It was also observed that active immunization against the fibrosarcoma caused stronger inhibition of pulmonary metastases in splenectomized than in sham‐operated mice.
EBV infections in Brazil. I. Occurrence in normal persons, in lymphomas and in leukemias
Authors: Carvalho R. P. S. , Evans A. S. , Frost P. , Dalldorf G. , Camargo M. E. , Jamra M. 
Published: February 2007

AbstractComparisons of IF antibody tests with EB3 and Jijoye cells indicated an overall agreement of 80%. However, the Jijoye line results in a higher frequency of positives at 1:10, a higher frequency of elevated titers of 1:160 or more, and a higher geometric mean antibody titer than with EB3 cells. At titers of 1:320 or higher the results with the two lines were quite comparable and are taken as elevated. Antibody to EBV is widely present in sera from Brazilian residents. Infection occurs early in life in the lower socioeconomic groups. In the middle and upper economic groups over 50% have antibody by age 12. In 69 lymphoma cases tested, all except one (Hodgkin's disease) had EBV antibody demonstrable at 1:10 titer or higher. Elevated EBVantibody titers at levels of 1:320 or higher were found in 41.9% of sera from the 43 cases of Hodgkin's disease having antibody and 4 of 8 cases of Burkitt's lymphoma; the geometric mean titers (GMT) were 1:173.4 and 1:246.8 respectively as compared to 1:51.4 in controls. In 13 cases of lymphosarcoma 23.1% had titers of 1:320 or higher and the GMT was 1:104.4. ERV antibody titer was present but not elevated in four cases of reticulosarcoma. Of 43 leukemia patients, one lacked EBV antibody at 1:10. Of the 42 possessing antibody, 31.0% had elevated titers with a GMT of 1:142.5. The highest titers occurred in mute myeloid leukemia.
Study of the cellular proliferation kinetics of friend leukemia
Authors: Smadja‐Joffe Florence , Jasmin C. , Malaise E. P. , Bournoutian Catherine 
Published: February 2007

AbstractWe have studied the kinetic parameters of the polycythemic variety of Friend leukemia using DBA2 mice inoculated with the virus. Proliferation was mainly observed in the erythroblasts of the spleen. The mean duration of the mitotic cycle is 7.6 h and the majority of erythroblasts are in active stages of the cell cycle. The proliferation rate is unaffected even during the hours preceding death. The multiplication of erythroblasts in the spleen results in three different phenomena: 1/3 of the erythroblasts produce short‐lived erythrocytes; a very small fraction (1/20) of the proliferation accounts for the slow growth of the spleen and the progressive invasion of the liver and the blood; 2/3 disappear, and this loss is apparently due to massive splenic cellular death.
Fractionation of plasma membrane‐associated tumour‐specific antigen from an aminoazo dye‐induced rat hepatoma
Authors: Baldwin R. W. , Harris J. R. , Price M. R. 
Published: February 2007

AbstractTumour‐specific antigens from an aminoazo dye‐induced rat hepatoma were liberated in a soluble form following limited papain digestion of tumour cell membrane preparations. Fractionation of the soluble extract by DEAE‐cellulose chromatography, gradient centrifugation and preparative electrophoresis yielded a major antigenic fraction, with an approximate molecular weight of 55,000, together with a range of other minor antigenic components of larger molecular weight. All preparations retained the capacity to inhibit the reaction of antibody in tumour‐immune sera with the plasma membrane of viable hepatoma target cells in the indirect immunofluorescence test. It is considered that the defined antigen fractions isolated provide material suitable for analysing the nature of tumour antigen expression in chemical carcinogenesis and for evaluating the involvement of antigen‐antibody interaction in tumour immunity.
Possible role of 6‐hydroxymethylbenzo[a]pyrene as a proximate carcinogen of benzo[a]pyrene and 6‐methylbenzo[a]pyrene
Authors: Flesher James W. , Sydnor Katherine L. 
Published: February 2007

AbstractBenzo[a]pyrene (B[a]P) and 6‐methylbenzo[a]pyrene ( 6‐MeB[a]P) are metabolized by fortified rat‐liver homogenates to a number of metabolites including one which is indistinguishable from 6‐hydroxymethylbenzo[a]pyrene (6–OHMeB[a]P) by either thin‐layer chromatography or ultra‐violet absorption spectra. This compound is a potent carcinogen when administered by subcutaneous injection to rats. These observations are in accord with the hypothesis that methylation or hydroxymethylation is one of the first steps in metabolic activation of carcinogenic polycyclic hydrocarbons.
Biochemical correlation of oncogenesis with ontogenesis
Authors: Wu Chung 
Published: February 2007

AbstractResults on enzyme induction in rat liver and kidney tumors have shown a striking resemblance between the tumors and the perinatal liver and kidney, on the one hand, and a sharp contrast between the tumors and the adult liver and kidney, on the other. Studies on isozyme distribution give similar results. Abnormalities in the responsiveness of enzymes to metabolic modulations and in the induction‐repression of isozymes reflect aberrations in the regulatory genes of the tumors. Since the liver and kidney tumors have originated from the adult liver and kidney, respectively, but show biochemical properties akin to those of the perinatal liver and kidney, it seems that during oncogenesis certain regulatory genes must have been so altered that the cell reacquires the control mechanisms prevailing in an early period of the life of the organism. Hence, a reversion of some of the regulatory apparatus in the cancer cell to that in the perinatal stage of development has taken place. This reversion is considered an essential mechanism in carcinogenesis.
Comparison of some of the biological properties of friend virus and its pseudotypes
Authors: Dawson Peter J. , Fieldsteel A. Howard 
Published: February 2007

AbstractThe properties of the Moloney and Graffi pseudotypes of Friend virus have been compared with those of our original strain of Friend virus. Qualitatively the pathologic effects of the three viruses were indistinguishable. The spleens of mice inoculated with each of the three viruses appeared to have a similarly low potential for the initiation of transplantable tumors in BALB/c mice. Both pseudotypes were highly age dependent when first isolated, although the Moloney pseudotype lost this property after the sixth passage in newborn BALB/c mice. Compared with our original Friend virus, there were marked differences between the host ranges of both pseudotypes. None of these viruses induced Friend disease in C57BL/6 mice. However, preparations of both pseudotypes and of the lymphatic leukemia viruses used as helpers readily induced lymphatic leukemia in this strain, indicating that susceptibility to the helper virus is not the only factor governing host range.
Cellular localization of an Epstein‐Barr virus (EBV)‐associated complement‐fixing antigen in producer and non‐producer lymphoblastoid cell lines
Authors: Reedman Beverley M. , Klein George 
Published: February 2007

AbstractAnti‐complement immunofluorescence (ACIF) was used to study the complementfixing antigens of human lymphoblastoid cell lines. These cell lines carry the Epstein‐Barr virus (EBV) genome although only producer cultures synthetize EBV‐specific antigens (virus capsid antigen, VCA and early antigen, EA) detectable by direct and indirect immunofluorescence, usually in less than 5% of the cells. The ACIF test revealed an antigen localized in the nucleus of the lymphoblastoid cells. In contrast to EA and VCA, this antigen was present in over 90% of the cells of both producer and non‐producer cultures. The antigen was shown to be specific for EBV by comparing the reactions of 52 sera in the ACIF test. Sera giving the nuclear reaction contained antibodies to VCA, EA or antigens detectable by complement fixation tests on cell extracts, but sera without EBV antibodies failed to give the reaction. Weak, equivocal or discordant reactions occurred with six sera with low titres in VCA, EA or complement fixation tests. Cell lines derived by transformation of human and primate lymphocytes by EBV gave the nuclear reaction. Control cells with no known association with EBV were non‐reactive. These included foetal lymphocytes transformed by phytohaemagglutinin, cell lines derived from breast cancer, glioma, normal glia, pleuritis maligna and myeloma, and two marmoset lymphoid lines carrying Herpesvirus saimiri (HVS). In preliminary experiments, the ACIF test was used as a tool to trace the EBV genome at the cellular level. Cells from two Burkitt lymphoma biopsies, one tested after biopsy and one after passaging in nude mice, contained an EBV‐specific antigen. Three clones of cells derived from hybrids of mouse somatic cells and a human lymphoblastoid cell line also contained such an antigen, but the number of reactive cells varied from clone to clone. A fourth clone was non‐reactive.
Auto‐immunization with acute leukemia cells: Demonstration of increased lymphocyte responsiveness
Authors: Gutterman J. U. , Mavligit G. , McCredie K. B. , Freireich E. J. , Hersh E. M. 
Published: February 2007

AbstractNine patients with adult acute leukemia were autoimmunized with 108 and/or 106 non‐irradiated leukemia cells during remission. Six of nine receiving 108 cells demonstrated a 100% or greater increase in in vivo lymphocyte blastogenic response to their own leukemia cells measured 7 days after immunization. In four responders, increased blastogenesis was noted only in autologous serum, but not in allogeneic serum. Only one of four demonstrated increased lymphocyte blastogenic response in autologous serum after immunization with 106 cells. The increased immune response was always accompanied by significantly increased blastogenic response to phytohemagglutinin (PHA) and/or Streptolysin‐O (SLO). Three patients studied 28–42 days following immunization showed a persistent increase in lymphocyte blastogenic response to leukemia cells, but the response to PHA and SLO had returned to pre‐immunization levels.
Immunoradioautography test for alpha‐fetoprotein in the differential diagnosis of germinogenic tumors of the testis and in the evaluation of effectiveness of their treatment
Authors: Elgort D. A. , Abelev G. I. , Levina D. M. , Marienbach E. V. , Martochkina G. A. , Laskina A. V. , Solovjeva E. A. 
Published: February 2007

AbstractThe diagnostic value of detecting AFP with the indirect immunoradioautography (IR) method has been investigated for teratoblastomas of the testis in adult patients. It is shown that the IR method permits an approximately two‐fold increase in the number of serologically diagnosed teratoblastomas, as compared with the standard gelprecipitation method. The results for patients with primary testicular teratoblastomas were 19 AFP‐positives in a group of 21 (90.5%). The diagnostic specificity of the test has been lowered insignificantly with the high‐sensitivity method: only 8 AFP‐positive cases were found in a control group of 215 patients, and all the seropositives suffered from tumors of the gastro‐intestinal tract with metastases to the liver. Application of the IR method has greatly increased the possibility of following the course of disease and effectiveness of treatment by the AFP test; in a number of cases it has also permitted a more accurate diagnosis of primary tumor, when metastases are present.
Studies on the ultrastructure of concanavalin a receptor sites at the surface of normal cells and cells transformed by oncogenic viruses
Authors: Torpier G. , Montagnier L. 
Published: February 2007

AbstractThe distribution of receptor sites for Concanavalin A at the surface of hamster fibroblasts BHK 21/13 transformed by RNA or DNA oncogenic viruses, has been studied at the ultrastructural level by the Concanavalin‐peroxydase method, in connexion with the agglutinability of these cells. The product of the lectin‐bound peroxydase activity has the same thickness in all clones studied. In some transformed clones, the observed reaction is more irregularly distributed than in the original untransformed clone. These changes are however not always accompanied by changes of agglutinability. Moreover, such an irregular distribution has also been found in normal cells from other species. It is concluded that the surface alteration detected by the peroxydase method cannot be considered at the present time as a general transformation character.
Specific neutralizing antibodies in Epstein‐Barr virus associated diseases
Authors: Rocchi G. , Hewetson J. , Henle W. 
Published: February 2007

AbstractThe results of Epstein‐Barr virus (EBV) neutralization tests on 650 sera from patients with EBV‐associated diseases and controls were compared with the titers of antibodies to EB viral capsid antigens (anti‐VCA) and to EBV‐induced early antigens (anti‐EA). All anti‐VCA negative sera failed to neutralize EBV. Among 546 anti‐VCA positive sera, only eight yielded negative results in neutralization tests. Four of these came from patients in the early acute phase of infectious mononucleosis who subsequently developed neutralizing antibodies. The ratios between neutralizing and anti‐VCA titers varied over a wide range indicating that different antibodies are involved in the two tests. In line with the regular presence of mostly elevated anti‐VCA titers, the geometric mean neutralizing titers in Burkitt's lymphoma and nasopharyngeal carcinoma were also higher (5‐ to 7‐fold) than in appropriate controls. In Hodgkin's disease, an over‐representation of high neutralizing as well as anti‐VCA titers was noted, although some patients had neither of these antibodies. All patients with infectious mononucleosis developed neutralizing antibodies with a geometric mean ultimately matching that of controls whereas in the early acute phase it was lower than in the controls. In contrast, the geometric mean anti‐VCA titer in the early acute phase was higher than in controls and then declined in convalescence toward the control value. There was no evident relationship between neutralizing and anti‐EA activities whether directed against the D or the R component of the EA complex.
Increase in viral antigen in individual polyoma‐virus‐infected mouse kidney cells as studied by quantitative immunofluorescence
Authors: Levin A. , Killander D. , Nordenskjöld B. 
Published: February 2007

AbstractPolyoma‐virus infection of mouse kidney cells in vitro was studied on the single cell level by quantitative cytochemical techniques. Cells were fixed in acetone at different times after infection and reacted with fluorescein‐conjugated mouse anti‐polyoma‐virus immune serum. Visual determinations were made as to whether the cells were fluorescent (“positive”) or not (“negative”). Visually the fluorescence was located in the nuclei in the “positive” cells. The fluorescence intensities of individual cell nuclei were then measured in a microspectrofluorimeter. Nuclei with considerable fluorescence intensity were noted to be visually “positive”. However, nuclei of cells which were usually judged to be “doubtful” could also be shown to have measurably greater fluorescence intensity than control non‐infected cells. Increase in fluorescence values were noted 6‐11 h after infection whereas hemagglutination tests did not become positive until 10‐20 h later. With increasing time post infection, the fraction of fluorescence positive cells increased both as judged visually and as determined by the microfluorimeter. The variation in fluorescence intensities among different nuclei also increased and, 48‐50 h after infection, the ratio between the highest and the lowest fluorescence values of positive cells was about 10:1. Higher fluorescence intensities were found in cytoplasms of cells with “positive” nuclei than in cells with “negative” nuclei. The cytoplasmic and nuclear fluorescence intensities correlated well in cells with “positive nuclei”. The polyoma‐virus infection‐induced stimulation of DNA synthesis was demonstrated by increased incorporation of 3H‐thymidine and by increased amounts of DNA in the cells as measured by Feulgen microspectrophotometry. The amount of DNase‐resistant DNA (i.e. viral DNA) correlated well with the intensity of immunofluorescence measured on the same individual nuclei of infected cells. This was taken as one indication that viral antigens can be measured on the single cell level by quantitative immunofluorimetry.