bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lymphoma of the Burkitt type in Singapore
Authors: Shanmugaratnam K. , Tan K. K. , Lee K. W. 
Published: February 2007

AbstractFourteen cases of lymphoma of the Burkitt type were found in a retrospective review of histopathological material in Singapore over a 15‐year period (1950–1964). The cases ranged from 4–14 years of age; there were 13 Chinese and 1 Indian and 12 male and 2 female patients in this series. The age‐specific incidence rates were 0.05 per 100,000 children per annum for the 0–4 year age group, 0.18 for the 5–9 year age group and 0.29 for the 10–14 year age group; there were no cases in the 15–19 year age group. The incidence rates for the 0–14 year age group were 0.25 per 100,000 children per annum for males, 0.04 for females and 0.15 for both sexes. The neoplasm comprised 3.6% of all histologically diagnosed cancers in the 0–14 year age group. The relative rarity of lymphoma of the Burkitt type in Singapore is of interest as the climatic conditions here conform to the observed requirements for endemicity of the disease in Africa.
The effect of adrenalectomy on the growth of mammary tumours induced by 3‐methylcholanthrene in rats
Authors: Daniel P. M. , Prichard Marjorie M. L. 
Published: February 2007

AbstractMammary tumours were induced in rats by intragastric administration of 3‐methyl‐cholanthrene. More than 75% of the tumours attained palpable size between 3 and 11 weeks after the last dose of the carcinogen. Adrenalectomy did not inhibit the growth of tumours already present and appeared even to encourage tumour growth. However, the stimulating effect of adrenalectomy was outweighed by the inhibition of tumour growth caused by subsequent removal of the ovaries.
Biochemical mechanisms of drug resistance IV. Development of resistance to 5‐azacytidine and simultaneous depression of pyrimidine metabolism in leukemic mice
Authors: Veselý J. , Čihák A. , Šorm F. 
Published: February 2007

AbstractThe development of resistance of leukemic AKR mice to 5‐azacytidine administered in small doses was investigated. The activity of uridine kinase decreased simultaneously with the development of resistance. The gradual shortening of the survival time of treated animals and the depression of enzyme activity had a continuous character. The application of 5‐azacytidine along with hydrocortisone or actinomycin D did not appreciably affect the development of resistance. In leukemic cells resistant to 5‐azacytidine the incorporation of uridine, cytidine and 5‐azacytidine itself into ribonucleic acids was depressed in accordance with the impaired anabolic transformations of 5‐azacytidine in vivo as well as with the soluble fraction in vitro.
Neutralization of the oncogenicity of moloney sarcoma virus and moloney leukemia virus by anti‐gross serum
Authors: Fefer A. , McCoy J. L. , Glynn J. P. 
Published: February 2007

AbstractA potent and specific rat anti‐Gross serum effectively neutralized the oncogenicity of Moloney Sarcoma Virus (MSV) and Moloney Leukemia Virus (MLV) of BALB/c origin. It also reacted against a BALB/c Moloney leukemia but not against a mineral oil‐induced BALB/c plasmacytoma by the indirect fluorescent antibody test. The results suggest that either Gross virus has some antigens in common with both MSV and MLV, or that Gross virus shares antigens with MLV which, in turn, determines the virion coat antigens of MSV.
Epidemiological findings and electron microscopic observations in human leukemia and canine contacts
Authors: van Hoosier G. L. , Stenback W. A. , Mumford D. M. , Hill W. A. , Dunn S. C. , Macdonald E. J. , Macdonald M. C. , Taylor H. G. , Trentin J. J. 
Published: February 2007

AbstractThree temporally and geographically restricted cases of acute lymphatic leukemia in children, in which two of the three patients had an unusual and suspicious history of canine contact, were investigated. Subsequent epidemiological studies showed a high frequency of dog contact and of dog bite in 100 leukemic, 48 lymphomatous, and 194 nonneoplastic control children. Thirty percent of the leukemic children had no history of dog contact or dog bite. Thin‐section electron microscopy studies of dog specimens revealed the presence of murine leukemia virus‐like particles in specimens from control dogs, tumorous dogs and non‐tumorous dogs associated with human leukemics. A higher incidence of such particles was found in the blood and urine of associated dogs than of tumorous or control dogs. These findings neither prove nor disprove an etiological relationship between dogs and cases of human leukemia. It is hoped that they will stimulate others to consider animal contacts with reference to human neoplastic disease.
Lactate dehydrogenase isoenzyme patterns in the tumour‐bearing colon
Authors: Langvad E. 
Published: February 2007

AbstractThe lactate dehydrogenase (LDH) isoenzyme pattern of the tumour‐bearing colon has been studied in homogenates by disc‐electrophoretic separation. The preponderance of M‐LDH in malignant tissue has been confirmed.It has been shown that the isoenzyme pattern may be altered in the absence of morphological changes. Thus, the metabolic change is not specifically dependent on the existence of tumorous parenchymatous changes as currently recognized by light microscopy.It is suggested that the tumour develops within a tissue where metabolic modifications may precede the stage of morphological malignancy.It appears, therefore, that the alteration of the enzyme pattern might be symptomatic of an established, but very early, neoplastic condition, the microscopic recognition malignancy being a later development.
Survey of human cancer patient sera for adenovirus “T” antibody by immunofluorescence
Authors: Malmgren Richard A. , Rabson Alan S. , Carney Paula G. 
Published: February 2007

AbstractSerum from 126 patients with various types of cancer and from 63 normal controls was examined by immunofluorescence for adenovirus 12 “t” antibody. Fourteen per cent of the cancer patients and 11% of the normals had antibody reactive with the adenovirus‐12‐infected green monkey kidney cells. The types of cancer which seemed most often to be associated with positively reacting sera were brain tumors, breast cancer and colon cancer.
Haemagglutinin production in tumour‐bearing and leukaemic mice
Authors: Gelzer J. , Dietrich F. M. 
Published: February 2007

AbstractTime‐course studies on anti‐sheep erythrocyte haemagglutinin formation after a single injection of antigen in tumour‐bearing and leukaemic mice yielded the following results: 1) Mice bearing (a) transplanted Ehrlich carcinoma or (b) primary mammary adenocarcinoma exhibited normal humoral antibody responses irrespective of the stage of tumour growth and the condition of the tumour‐bearing animal; 2) Rauscher leukaemic mice, on the other hand, showed marked abnormalities in antibody‐producing capacity. Sequential measurements revealed an increasing degree of immunodepression as the leukaemia progressed. However, the impairment of antibody production was already increased appreciably during the first aleukaemic phase of Rauscher disease 10 days after inoculation with the leukaemic virus; this was followed, during the second leukaemic phase, by a slight return of haemagglutinin‐forming capacity although not to normal levels. The terminal leukaemic stage was characterized by the strongest immunodepression recorded in the course of Rauscher disease.All leukaemic mice eventually exhibited a late immunodepression approximately 30 days after immunization. The various degrees of qualitatively and quantitatively differing immunological abnormalities are discussed in relation to the pathogenesis of Rauscher disease.
Continuous viral replication and cellular neoplastic transformation in cultures of normal rat thymus infected with gross leukemia virus
Authors: Ioachim Harry L. , Berwick Leonard 
Published: February 2007

AbstractTo develop a system for the study of Gross leukemia virus (GLV) replication in vitro, cultures of embryonal rat thymus were infected, grown for long intervals, and periodically examined for infectious virus. Supernatants assayed in susceptible animals induced leukemia in 93%, and electron micrographs of cultures confirmed the presence of abundant virus particles. Comparable cultures of spleen and kidney did not support viral replication. Morphologic differences were noted between the appearance of virus‐infected and control cultures. Isotransplantation of the former in conditioned rats resulted in formation of tumors at the site of injection. These tumors had the histologic pattern of reticulum‐cell sarcomas, were serially transplantable in non‐conditioned hosts, and continued to carry the initial GLV. The thymus, which is a target organ for GLV in vivo, appears to be similarly favorable for its replication in vitro. In addition, neoplastic transformation has occurred in these cultures, presumably induced by GLV.
Mise en évidence chez le rat d'un facteur génétique dans la cancérisation par le diméthylaminoazobenzène. Presence in the rat of a genetic control of dab‐carcinogenesis
Authors: Chauveau Jean , Decloitre Françoise 
Published: February 2007

AbstractTwo strains of white rats, one of which (Sprague‐Dawley) was sensitive, another (Wistar) not, to liver cancerization by DAB, were studied comparatively in an attempt to find biochemical characteristics which might explain this difference, that is changes in the activity of the enzyme, DAB‐reductase, and in the binding of azo metabolites to liver proteins.The animals were administered a whole diet, rich in proteins and in vitamins. When not fed DAB, the activity of DAB‐reductase was five‐fold higher in Wistar than in Sprague‐Dawley rats; the continuous administration of DAB causes a progressive decrease of the enzyme activity in the two strains. After 10 days of carcinogenic diet the amounts of azo proteins are maximal and at this time they are twice higher in Sprague‐Dawley than in the Wistar rats. Hepatomas appear in the Sprague‐Dawley strain without a lag phase, as early as the fifth week of treatment.The resistance to cancerization appears to depend principally on a genetic factor which would allow a more or less efficient detoxification, mediated by the enzyme, DAB‐reductase.
Studies on a naturally occurring human antibody active against mouse landschutz ascites tumor cells: I. Cytotoxicity assay system and quantitation in normal sera
Authors: Laskov R. , Simon E. , Gross J. 
Published: February 2007

Abstract1. A quantitative cytolytic assay system was developed for the titration of the natural cytotoxin of human serum (NHS) which is active against Landschutz ascites tumor cells. The assay system consists of NHS52 or NHS as a source of antibody and human umbilical cord serum as a source of complement.2. Von Krogh plots of the cytotoxin and complement titration data gave 1/n slope values which were comparable to those obtained in the literature for acquired hemolytic and cytolytic immune systems. The values for the cytotoxin were compatible with those obtained with IgM antibodies.3. The level of this natural antibody in 101 individual sera was examined. Titers ranging from 10 to about 600 LD50 units/ml were found. On the average 93.4 units/ml were present.4. There was a relationship between blood group and antibody titer. The mean titers of groups O and A individuals were higher than those of groups B and AB individuals. This would indicate an antigenic cross‐reactivity between the B blood group antigen and antigen (s) on the ascites tumor cell.5. Guinea‐pig serum could replace human complement in the titration of the natural cytotoxic antibody but was much less effective than human complement.
Studies on a naturally occurring human antibody active against mouse landschutz ascites tumor cells: II. Identification of the antibody as igm and its partial purification
Authors: Laskov R. , Simon E. , Ram D. , Gross J. 
Published: February 2007

Abstract1. The cytotoxic antibody in normal human serum, active against mouse tumor cells, was identified as a 19S macroglobulin by means of Sephadex gel filtration, DEAE‐cellulose chromatography and density‐gradient centrifugation procedures.2. A purified IgM fraction was isolated from normal human serum. The cytotoxic activity of this fraction, as tested against mouse tumor cells, was enriched 20–80 times over that of the unfractionated serum. The purified IgM showed mainly one precipitin line on immunoelectrophoretic analysis. In the ultracentrifuge the 19S peak comprised about 85% of the total protein.
Mechanism of preventive immunization with the aid of rauscher virus culture having an attenuated leukemogenic potential
Authors: Youn Jung Koo , Barski Georges , Barbieri Dominique 
Published: February 2007

AbstractThe experiments reported here were aimed at elucidating mechanisms involved in the immunization of mice against Rauscher leukemia with the aid of in vitro cultivated cells chronically infected with the “attenuated” Rauscher virus.BALB/c mice were implanted intraperitoneally with Algire‐type, 0.45 μ porosity, Millipore chambers containing Rauscher‐virus‐infected cells. The animals developed leukemia when the cells in the chambers originated from leukemic spleens producing the virulent virus. On the contrary, when the cells in the chambers originated from cultures producing “attenuated” virus, the mice developed no disease but firm and specific immunity.Cytotoxic tests performed with anti‐viral sera, obtained in hyperimmunized mice or monkeys, showed that the density of viral antigen was of the same order of magnitude on the surface of cells infected in vivo with the highly leukemogenic virus (leukemic spleen cells), as on cells infected in vitro and showing a moderately or highly attenuated leukemogenic potential. These data were fairly concordant with the results of electron microscopic examinations of the corresponding cell preparations for the presence of type C and A virus particles, which were equally abundant in both cases.In addition to the neutralization of the virus by circulating anti‐viral antibodies, other mechanisms seem to be operating in animals vaccinated with the in vitro virus cultures. It appears that these animals were protected not only against challenge with the virulent virus but also against inoculation with leukemic cells. On the other hand, immunity produced by this type of vaccination could be efficiently transmitted by transfer of lymphoid cells from immunized donors to intact recipient animals even if these animals had no detectable anti‐viral antibodies when they were challenged with the virulent virus.In conclusion, the mechanism of immunization with the aid of “attenuated” Rauscher virus cultures is of a complex nature. It is conditioned on the one hand by the production of circulating anti‐viral antibodies induced by the in vitro “attenuated” cultured virus, antigenically similar or identical to the “virulent” virus; on the other hand, one has to envisage an immunological mechanism of a cellular type which can be transferred by sensitized lymphoid cells and which may be induced by a cellular neoantigen common to the in vitro infected cell cultures and the leukemic cells.
Induction of thymidine−3h incorporation in multinucleated myotubes by rous sarcoma virus
Authors: Lee H. H. , Kaighn M. E. , Ebert J. D. 
Published: February 2007

AbstractDuring the differentiation of skeletal muscle, mononucleated myoblasts fuse to form multinucleated myotubes. After fusion, both DNA synthesis and nuclear division cease. When clones of chick embryonic leg muscle consisting of both myoblasts and myotubes are infected with Rous sarcoma virus, DNA synthesis (as measured by thymidine‐3H incorporation) is induced in the nuclei of myotubes within 24 hours. On the other hand, nuclear division is not reactivated. These findings indicate that the restriction of DNA synthesis which attends the formation of myotubes is not irreversible since RSV, an RNA virus, reactivates DNA synthesis in mature myotubes.
Viral inclusions and other cytoplasmic components in a leydig cell murine tumor: An electron microscopic study
Authors: Pourreau‐Schneider Natalie , Stephens Robert J. , Gardner William U. 
Published: February 2007

AbstractCytoplasmic inclusion bodies which were clearly visible under light microscopy have recently been described in estrogen‐induced testicular interstitial cell tumors of mice. An ultrastructural study has revealed that the inclusions were formed of considerable numbers of type A virus particles which measured approximately 76 mμ in external diameter. Despite the abundance of intracytoplasmic viral particles, there was no sign of extracellular release or budding of mature particles from cellular membranes. Among the unusual cytoplasmic components of the tumor cells were bundles of filaments with a wavy appearance and a distinctive cross‐sectional pattern. These fibrillar structures may be a cellular manifestation of the presence of virus. In discussion, the inclusions of the testicular intestitial cell tumors are compared to inclusions found in other murine tumors.
Cultivation and fine structure of virus‐bearing lymphoblasts from a second new guinea burkitt lymphoma: Establishment of sublines with unusual cultural properties
Authors: Pope J. H. , Achong B. G. , Epstein M. A. 
Published: February 2007

AbstractTwo sublines of cells (QIMR‐AMB/1 and QIMR‐AMB/2) were established from a New Guinea Burkitt lymphoma. In contrast to previously described lines of cultured Burkitt lymphoma cells, there was a first phase of active proliferation of lymphoblasts completely dependent on an autologous fibroblast moiety of the cultures. In a second phase, lymphoblasts able to grow independently in suspension appeared at 8–10 weeks and gradually completely repopulated the cultures. Cytological and electron microscope studies showed that the lymphoid cells of the first phase resembled other cultured Burkitt lymphoblasts, and that the cells characteristic of the second phase were somewhat less differentiated. A herpes‐type virus, not transmissible in various tissue cultures or in mice, was detected by electron microscopy in some of the cells.
Studies on the biology of the mycoplasma‐induced “stimulation” of BHK21‐c13 cells
Authors: Russell W. C. , Niven Janet S. F. , Berman L. D. 
Published: February 2007

AbstractFurther investigations on the action of mycoplasmas on BHK21‐C13 cells are described. In addition to the already recorded alterations in cellular morphology, ability to form colonies in soft agar and changes in cellular nucleic acid metabolism, it has been found that the mycoplasma‐infected cells and the altered cells (in which no mycoplasmas could be detected) have an increased plating efficiency and an increased tumorigenicity. However, tumours produced by the altered (BHK21‐Mf) cells failed to show either mycoplasmas or foreign cellular antigens and their morphology is essentially similar to tumours produced by the control BHK21‐C13 cells. Analysis of the BHK21‐C13 cell—mycoplasma interaction has led to the conclusion that the phenomenon is not directly comparable to the usual type of neoplastic transformation produced by oncogenic viruses. However, implications of results such as these, obtained with the inherently neoplastic BHK21 cell line, must always be interpreted with caution.
Studies on cross‐resistance to degranol‐ and dibromodulcitol‐resistant yoshida tumours
Authors: Gáti Éva 
Published: February 2007

AbstractCross‐resistance studies were carried out on a series of sugar alcohol derivatives substituted in positions 1 and 6 with various functional groups. Yoshida ascites tumours resistant to Dibromodulcitol as well as to Degranol proved to be cross‐resistant to Degranol, Dibromodulcitol, Dibromomannitol and Mannitolmyleran. Myleran and Vinblastine sulphate inhibited the growth of the sensitive and resistant tumours to the same degree. Experiments with bilaterally growing solid forms of these tumours yielded the same result. The relationship between the chemical structure and the mechanism of this cross resistance is discussed.
Murine sarcoma virus (harvey): Characteristics of focus formation in mouse embryo cell cultures, and virus production by hamster tumor by cells
Authors: Bassin R. H. , Simons P. J. , Chesterman F. C. , Harvey J. J. 
Published: February 2007

AbstractTitrations of the Harvey isolate of murine sarcoma virus (MSV) in mouse embryo cells indicated that infection of a cell with MSV alone might not be sufficient to induce focus formation. Addition of high concentrations of Moloney leukemia virus to diluted MSV preparations resulted in an increased number of foci, consistent with the hypothesis that Moloney leukemia virus can act as a helper for defective MSV (Harvey).A transplantable hamster tumor line was established by inoculation of fragments from an MSV‐induced mouse tumor into newborn hamsters, followed by repeated passage in adult hamsters. Tumor tissue from the 25th hamster transplant generation of this tumor line was used to establish a cell line — “B‐34” — in culture. B‐34 cells elaborated a filtrable agent which produced sarcomas and other lesions characteristic of MSV when inoculated into newborn hamsters, but which did not produce any observable pathological changes when inoculated into newborn mice. However, mixed cultures of B‐34 cells and normal mouse embryo cells, when superinfected with Moloney leukemia virus, released MSV infective for both mice and mouse embryo cell cultures.
Ultrastructure of a mouse sarcoma in its solid, enzymatically dissociated and ascitic forms
Authors: Boeryd B. , Lundin P. M. , Norrby K. , Schelin U. 
Published: February 2007

AbstractAscites tumor cells differed from cells of the solid tumor in possessing filamentous structures in the marginal parts of the cytoplasm, in demarcated juxtanuclear areas and in uniform microvillous surface protrusions — “microspikes”. In free cells, dissociated from the solid tumor by trypsin and deoxyribonuclease, filamentous structures and microspikes of the same kind as in ascites tumor cells appeared regularly, evidently as an adaptation to the free‐cell state. In ascites tumor cells, exposure to crude trypsin led to detachment of microspikes and occasionally of larger cytoplasmic buds. Similar effects, although less frequent, occurred after treatment with crystalline trypsin.
Report on the workshop on virus induction by cell association
Authors: Svoboda Jan , Simkovic Dusan , Koprowski Hilary 
Published: February 2007

AbstractAccording to the decision reached at the meeting of the Committee of Virology and Immunology of the UICC held at Sukhumi, USSR, in May, 1965, a Workshop on Virus Induction by Cell Association was held at The Wistar Institute on November 2 and 3, 1967. The Workshop was attended by scientists from the following countries: Canada, Czechoslovakia, France, Germany, Japan, Sweden, United Kingdom, United States and USSR.The subject of the first session was “The Investigation of Rous Sarcoma Virus”.
Effect of reticuloendothelial system stimulation on resistance to rous sarcoma virus infection in chicks
Authors: Bliznakov Emile G. 
Published: February 2007

AbstractBy using a non‐toxic reticuloendothelial system stimulant, lipid‐Restim, derived from shark livers, we were able to demonstrate the following effects on growing Rous sarcoma tumors in young chicks. Prechallenge Restim treatment: Significant reduction of the percentage of chicks with tumors and prolongation of the latent period resulted from combined administration of Restim and specific antiserum. Postchallenge Restim treatment: The mortality data indicated that there was a significant increase in survival time and survival rate. Complete regressionsThe term “regression” is used in this paper to mean complete macroscopical disappearance of the primary tumor at the site of inoculation of the virus.
occurred in a significant number of the Restim‐treated chicks compared to the controls. Possible explanations of these findings are discussed.