bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rous sarcomas induced by heterotransplantation of virogenic rat tumour cells in mice
Authors: Bubeník J. , Barešová M. , Micheel B. , Sovová V. , ElRidi R. , Keclíková M. 
Published: February 2007

AbstractThe virogenic sarcoma RSL was induced in inbred Lewis rats by the Schmidt‐Ruppin variant of Rous virus (SR‐RSV).Heterotransplantation of RSL cells to newborn C57BL/10Sn mice gave rise to mouse sarcomas in approximately 10% of the recipients. The properties of one of these mouse sarcomas, designated as RSM, were compared with those of the original rat tumour line RSL.It was found that (1) RSL cells did not contain detectable amounts of infectious chicken, rat or mouse sarcoma virus. However, in contact with permissive chicken fibroblasts the RSL cells produced malignant conversion of avian cells accompanied by the formation of infectious RSV. RSL cells carried a tumour‐associated transplantation antigen (TATA) of Rous sarcomas, a group‐specific (gs) antigen of avian leukoviruses and a membrane antigen (MA), characteristic of Rous sarcomas, detectable by indirect immunofluorescence and cross‐reacting with MA of mouse Rous sarcomas. The MA characteristic of tumours induced by mouse leukoviruses was not detected in the membrane of RSL cells.(2) RSM cells did not contain detectable amounts of oncogenic avian, mouse or rat viruses in an infectious form. Neither contact of these cells with permissive chicken c/o fibroblasts nor heterotransplantation of RSM tumours to chickens led to malignant conversion of avian cells. Gs antigen of avian leukoviruses was not detectable in RSM cells. However, TATA and MA characteristic of Rous sarcomas were present. Neither MA nor TATA induced by mouse leukoviruses was detected in RSM cells.The results obtained indicate that the non‐infectious RSV genome present in rat virogenic cells is able to induce tumours in a further mammalian species.
Establishment of continuous lymphoblast cultures from leukocytes of gibbons (Hylobates lar)
Authors: Werner Jürgen , Henle Gertrude , Pinto Carl A. , Haff Richard F. , Henle Werner 
Published: February 2007

AbstractEfforts were made to establish continuous lymphoblast cultures from peripheral leukocytes of gibbons.
(Hylobates lar).by co‐cultivation with lethally X‐irradiated human lymphoblasts from Epstein‐Barr virus (EBV)‐producing lines of infectious mononucleosis or Burkitt tumor origins. EBV‐positive lymphoblast lines were derived from all of five animals tested, of which four had no antibodies to EBV‐related antigens and one a marginal level. Growth became evident after an average of 26 days. Several months after injection of autochthonous cultured cells and seroconversion, co‐cultivation again yielded lymphoblast lines, but growth became evident on the average within only 55 days. Separate cultures of the X‐irradiated lymphoblasts or the leukocytes, whether obtained before or long after seroconversion, died within 2–3 weeks. Even during the period of seroconversion only one line became established in numerous attempts without the benefit of co‐cultivation.Injection of cultured lymphoblasts into the authochthonous animals by different routes failed to induce tumors (or any signs of illness) despite attempted immuno‐suppressive treatment of three of the animals prior to transplantation of the cells. All animals responded with antibody formation to EB viral capsid antigens within 2 to 5 weeks. The time of seroconversion apparently depended upon the percentages of EBV antigen‐containing cells in the cultures. Three animals developed low levels of antibodies to the D component of the EBV‐induced early antigen complex.Similarities and dissimilarities with results of human leukocyte cultures as well as the implications and deficiencies of these experiments are discussed.
The lymphocyte response to a primary viral neoplasm (MSV) through its entire course in BALB/c mice
Authors: Lamon E. W. , Skurzak H. M. , Klein Eva 
Published: February 2007

AbstractBALB/c mice injected with Moloney sarcoma virus (MSV) developed tumors within 5–8 days which usually completely regressed by day 20–25. Maximal tumor size was around day 15. Lymphocytes from these animals were examined for activity against target cells bearing the Moloney leukemia virus (MLV) associated cell surface antigen at 2‐ to 5‐day intervals for 30 days. Significantly cytotoxic lymphocytes were obtained from animals which had developed no palpable tumor as early as 2 days after infection and from animals in which tumors had completely regressed. The least active lymphocytes were from tumor‐bearing animals. The cytotoxicity of the active lymphocytes was demonstrated to be antigen‐specific by testing also against target cells which were MLV‐negative.
The formation of variants with a reversion of properties of transformed cells. VIII. in vitro limited life span of variants isolated from tumors
Authors: Rabinowitz Zelig , Sachs Leo 
Published: February 2007

AbstractCells transformed after treatment with the chemical carcinogen dimethylnitrosamine (DMNA) inoculated into animals, can produce tumors containing variants with a reversion of in vitro properties of transformed cells. In contrast to variants from tumors produced by polyoma‐transformed cells, 83% of the variants in tumors from DMNA‐transformed cells had again acquired, like normal cells, a limited life‐span. in vitro. Seventeen % of the variants escaped the termination of their life‐span by re‐reverting to the transformed state.
Étude expérimentale de la diffusion métastatique chez l'œuf de poule embryonné. Répartition, microscopie et ultrastructure des foyers tumoraux
Authors: Vlaeminck M. N. , Adenis L. , Mouton Y. , Demaille A. 
Published: February 2007

AbstractThe injection of mouse ascite Ehrlich carcinoma cells into a vein in the chorioallantoic membrane of chick embryos at the eleventh day of incubation permits the observation of tumoral focuses analogous to metastasis in intra‐ or extraembryonic viscera, in 70% of embryos, dead or killed between the seventeenth and the twenty first day of incubation. A very clear selectivity can be observed in the invasion of the different organs by the carcinoma cells. The liver is injured most, with a level of metastasis of about 25%, while the spleen is almost never injured. Between these two extremes are ranged the brain, heart, nephros and lungs. The frequency of tumoral nodules in the chorioallantoic membrane, and the richly vascularized mesenchymatous structure of this organ allows for some aspects of tumoral invasion to be analyzed, particularly the relationship between cancer cells and blood vessels. As shown by electron microscopy, the passage of the cancer cells through the capillary barrier is achieved successively by apposition to the outer wall of the vessel, distribution of the basal membrane, endothelialisation and then immediate embolisation without associated thrombosis.
Carcinogenicity of contaminants in indigenous edible oils
Authors: Ranadive Kamal J. , Gothoskar Sunanda V. , Tezabwala Bilquis U. 
Published: February 2007

AbstractEdible oil is one of the essential constituents of Indian diet which has to be free of hazardous contaminants. A variety of oils are used in different parts of the country, e.g. ground‐nut oil, mustard oil, coconut oil, sesame oil, etc. A series of ground‐nut oil, mustard oil and soya‐bean oil samples have been tested for carcinogenicity due to possible contaminants: (i) solvent residues and (ii) argemone oil. The experiments are divided into two parts: I. Testing the carcinogenicity of solvent‐extracted edible oils, and II. Testing carcinogenicity due to argemone oil. Two strains of mice, inbred C17‐specially developed for testing environmental carcinogens‐and inbred Swiss from the Cancer Research Institute, have been used as test animals. Three routes of administration have been used: (i) cutaneous application, (ii) single and multiple subcutaneous injections and (iii) oral feeding by stomach tube.I. Solvent‐extracted oils: The results of testing experiments in 1966 indicate the carcinogenic effect of many indigenous solvent‐extracted ground‐nut oil samples as against machine‐expressed oils and imported soya‐bean oils that are mostly free of carcinogenic effect. The second batch of ground‐nut oil samples tested in 1969 after change of solvent to proper food‐grade n‐Hexane show significant improvement.II. Effect of argemone contamination: Pure laboratory‐expressed argemone oil, diluted in different concentrations in (i) imported soya‐bean oil, (ii) authentic expressed mustard oil and (iii) market tinned oil, as well as pure argemone oil control and other solvent controls, have been tested for carcinogenicity. The data indicate that argemone oil by itself is not carcinogenic at the dose levels tested. In combination with non‐carcinogenic soya‐bean oil and authentic mustard oil also it had hardly any carcinogenic effect. On the other hand, the market sample of tinned mustard oil was weakly carcinogenic by itself; the carcinogenic effect is significantly enhanced by addition of argemone oil at the 1 and 2% level. The data suggest that argemone oil has a co‐carcinogenic effect and the market sample of mustard oil possibly contains weakly carcinogenic principles other than the argemone oil. These observations invite further investigations on market samples of edible oils.
Toxic effect of 7,12‐dimethylbenz‐α‐anthracene on neoplastic cells grown in mixed cultures with normal fibroblasts
Authors: Mittelman L. A. , Sharovskaya Ju. Ju. , Vasiliev Ju. M. 
Published: February 2007

AbstractNeoplastic L fibroblasts grown in isolated cultures are highly resistant to the toxic effects of carcinogenic hydrocarbons. However, these cells become very sensitive to the toxic effect of 7,12‐dimethylbenz‐α‐anthracene (DMBA) if they are grown on the surface of the monolayer of normal mouse fibroblasts. The density of L cells grown on the glass surface in the same mixed cultures was not significantly changed by DMBA. L cells seeded in the culture of normal fibroblasts 3 days after the removal of DMBA from the medium were not damaged. These experiments indicate that normal fibroblasts exposed to DMBA transmit some toxic factor to L cells placed in their immediate vicinity. It is suggested that this factor may be some short‐lived metabolite of DMBA formed within the normal cells. It is possible that such a “lethal metabolic cooperation” with normal cells may considerably change the sensitivity of neoplastic elements in vivo to various toxic substances.
Cellular and humoral immunity to rat hepatoma‐specific antigens correlated with tumour status
Authors: Baldwin R. W. , Embleton M. J. , Robins R. A. 
Published: February 2007

AbstractLymphocytes from rats bearing primary or transplanted aminoazo‐dye‐induced hepatomas were specifically cytotoxic for cells of the same tumour. Cytotoxic antibody was not present in the serum of these animals, although humoral factors capable of abrogating lymph‐node cell‐mediated cytotoxicity in vitro were detected. Following excision of transplanted hepatomas, cytotoxic lymph‐node cells were still demonstrable, with slightly increased reactivities comparable to those detected in a previous study of repeatedly immunized rats. Cytotoxic antibody was present in serum after tumour excision, and this correlates with the loss of serum blocking activity for lymph‐node cell‐mediated cytotoxic effects. In comparison, serum from rats repeatedly immunized to hepatomas, where high levels of cytotoxic antibody are also present, blocks lymph‐node cell‐mediated reactions in vitro, despite the immune status of the donor. These considerations suggest qualitative differences between the blocking factors in the serum of tumour‐bearer and tumour‐immune hosts, the former being antigen‐antibody complexes, and the latter free antibody.
Failure to demonstrate immunity to leukemia associated antigens by lymphocyte transformation in vitro
Authors: Schweitzer Marjan , Melief C. J. M. , Eijsvoogel V. P. 
Published: February 2007

AbstractMixed cultures of leukemic cells from acute lymphatic leukemia patients with autologous remission lymphocytes and of leukemic cells from both acute lymphatic leukemia patients and chronic lymphocytic leukemia patients with the lymphocytes from an HL‐A identical sibling were performed to investigate whether sensitization against leukemia‐associated antigens was demonstrable. Although in some cases marked thymidine incorporation was measured, this cannot be interpreted as stimulation by leukemia‐associated antigens, because it cannot be distinguished from non‐specific thymidine incorporation as was shown to occur sometimes in unstimulated cultures. It is concluded that the lymphocyte transformation technique is unsuitable for the detection of immunity to leukemia‐associated antigens.
Fine structure of pituitary tumors and transplants in mice: Effects on the prostate
Authors: Petrea I. , Gardner W. U. 
Published: February 2007

AbstractTwenty‐seven primary pituitary tumors (PPT) arose in 109 mice bearing transplanted pituitary glands (TPG). Several PPT were transplanted serially into isologous hosts. Transplanted pituitary tumors (TPT) from 79 different male or female hosts were obtained between 42 and 708 days after transplantation. Histological and electron microscopic preparations of the TPG, PPT and TPT were prepared. The TPG showed much cellular necrosis and diminished secretory activity during the first month. Cellular replacement and secretory granules reappeared after revascularization of the grafts and coincident with the reappearance of somatotrophic and mammotrophic activity in the female hosts. The TPG showed no significant growth for about 1 year and about 25% of the transplants became tumorous after 400 days. EM examination of the PPT revealed heterogeneous secretory granules resembling those of the alpha and beta type in the same cell. The endoplasmic reticulum (ER) was abundant and the mitochondria were large and many were structurally abnormal. The TPT usually grew slowly but differed from tumor line to tumor line. By six months after transplantation the TPT were polynodular, with red nodules and white nodules. In both red and white tumoral nodules, the cells were PAS, reticulin, amyloid, elastin and Masson‐negative, and showed some autoradiographic activity after proline‐H3 administration. Also, the EM shows no significant difference between the nodules. Fibrils about 70 Å in diameter were in the ER, and 100–300 Å in diameter in plasma fundamentalis, and fibers larger than 300 Å in extracellular areas. The fibrillar synthesis in the TPT cells was in inverse ratio to the granular secretory activity of the cells. Sixteen of the TPT in CB 815 and 87 hybrid mice contained C‐type virus‐like particles (VP). Viral particles were noted in the periphery of the nucleus, and in the endoplasmic reticulum. Cells with the most viral particles showed the least granular secretory activity. The TPT in females were mammotrophic, and in males prostatotrophic. The prostatic epithelial cells contain cytoplasmic organelles with delicate lamellae in fingerprint, whorl, or tubular arrangement and amorphous granular aggregates. Mice with TPT for several months had enlarged prostates, some having intraluminal hyperplastic trabeculae, and cells showing less secretory activity. In mice with two lines of TPT, C‐type viral particles appeared in the prostatic cells.
Establishment of multiple lymphoblastoid lines from single lymph nodes and study of their immunoglobulin synthesis
Authors: Béchet J. M. , Nilsson K. , Pontén J. 
Published: February 2007

AbstractBiopsies of one normal lymph node and two lymphomas were explanted into a number of independent cultures. Lymphoblastoid lines were established from a high proportion of the cultures from each biopsy. The immunoglobulins synthesized by each line were characterized and used as cell markers in an attempt to obtain information on the cellular origin of the lines. The majority of the lines produced, at the beginning of their culture history, several types of heavy and light chains, but this pattern evolved in the course of cultivation towards the production of only one species of immunoglobulin. Lines from the same lymph node differed from each other by the types of immunoglobulins produced, both initially and at a later stage. The results suggest that lymphoblastoid lines are derived from a non‐clonal population of precursor cells, and argue against the neoplastic nature of these cells.
Secretory and mitotic response of the male rat pituitary gland to repeated doses of oestrogen
Authors: Lloyd H. M. , Meares J. D. , Jacobi Joan 
Published: February 2007

AbstractPituitary weight, pituitary mitotic index and pituitary and serum concentrations of growth hormone and prolactin were measured at 14‐day intervals in male rats given 10 mg diethylstilboestrol dipropionate SC every 14 days for a total period of 70 days. Mean pituitary weight reached a maximum of 21 mg on day 42 and no pituitary gland became a tumour according to a criterion of weight greater than 30 mg. Mitotic index was greatly increased until day 70 when it diminished significantly. Pituitary concentration of growth hormone decreased to maintain a low constant level from day 28 onwards while pituitary prolactin concentration rose to a maximum on day 42. Serum growth hormone was elevated on day 14 and then gradually diminished, while serum prolactin continued to increase until day 42. Pituitary weight and serum prolactin were significantly correlated and pituitary mitotic index was negatively correlated with pituitary growth hormone concentration. The state of apparent equilibrium in mass reached by the pituitary glands from day 42 until day 70, despite greatly increased secretory and mitotic activity, suggests that further disturbance of pituitary function is necessary to bring about net gain in cell numbers and lead to tumour formation.
Effect of human placental lactogen on growth of carcinogen‐induced mammary tumors in rats
Authors: Nagasawa Hiroshi , Yanai Reiko 
Published: February 2007

AbstractThe effect of exogenous administration of human placental lactogen (HPL) on 7,12‐dimethylbenz(a)anthracene (DMBA)‐induced mammary tumors was studied in female Sprague‐Dawley rats. Twice daily injections of 1 or 2 mg HPL for 20 days showed marked stimulation of appearance and growth of mammary tumors and of normal mammary gland growth not only in intact but also in adreno‐ovariectomized rats. These results suggest that placental lactogen plays an important role in the growth of DMBA‐induced mammary tumor of rat and that it acts on mammary tumorigenesis during pregnancy both directly and indirectly through its promotion of progesterone secretion by the ovary.
Specific “arming” of normal lymph‐node cells by sera from tumor‐bearing mice
Authors: Pollack Sylvia 
Published: February 2007

AbstractLymph‐node cells of non‐sensitized mice were “armed” (i.e. made specifically cytotoxic) by exposure in vivo to passively transferred sera from tumor‐bearing mice. Four hours after an intraperitoneal injection of antitumor serum, the lymph nodes were removed from recipient mice and the activity of the lymph‐node cells was tested on tumor cells in an in vitro microcytotoxicity test. Specific cytotoxicity was demonstrated to the respective target tumors (Moloney virus or 3‐methylcholanthrene‐induced sarcoma) carried by the tumor‐bearing serum donors.
The effects of neonatal thymectomy on the antitumour activity of lentinan, carboxymethylpachymaran and zymosan, and their effects on various immune responses
Authors: Maeda Yukiko Y. , Chihara Goro 
Published: February 2007

AbstractThe mechanism of antitumour action of the polysaccharides, lentinan and carboxymethylpachymaran, was examined and compared with that of zymosan. It was revealed that (1) these polysaccharides did not show any direct cytocidal effect on tumour cells; (2) these polysaccharides had no antitumour action at all in neonatally thymectomized mice, indicating the important role of the thymus gland in tumour regression; and (3) in spite of these facts, these polysaccharides, contrary to zymosan, did not accelerate various conventional immune responses such as phagocytic activity, antibody production against heterologous antigen, increased number of peripheral lymphocytes, skin homograft rejection, and delayed hypersensitivity. This evidence suggests the presence of a complex and unknown mechanism for regression of transplanted tumour in the action of lentinan and carboxymethylpachymaran.
Leukemia induction in C3H mice following their inoculation with normal AKR lymphoid cells
Authors: Nemirovsky Theodore , Trainin Nathan 
Published: February 2007

AbstractNewborn C3H mice were injected with viable or in vitro X‐irradiated cell suspensions from lymph node and spleen mixtures obtained from healthy AKR donors aged 12 to 18 months. Of the group injected with normal intact cells, 30% developed a lymphocytic leukemia, whereas none of the recipients of irradiated cells did so. Genetic analysis showed that the leukemias appearing in C3H mice originated de novo in the recipient animals apparently as a result of their inoculation with immunocompetent lymphoid cells. The results obtained by using this model of leukemia induction are discussed on the basis of participation of a graft‐versus‐host reaction in this process.
Immune responses in mice to tumour challenge after immunization with newcastle disease virus‐infected or X‐irradiated tumour cells or cell fractions
Authors: Beverley P. C. L. , Lowenthal R. M. , Tyrrell D. A. J. 
Published: February 2007

AbstractCells of the transplantable ascites tumour sarcoma 37 (S37) have been infected in vitro with Newcastle disease virus (NDV). Infected cells, a virus‐containing fraction of such cells, and X‐irradiated S37 cells have been found to immunize mice against subsequent tumour challenge. Anti‐lymphocyte serum and anti‐theta serum interfered with this immune response. The level of humoral anti‐tumour antibody did not correlate with immunity. Preimmunization with homologous virus (NDV) prior to inoculation with a virus‐containing tumour cell fraction did not in this system enhance the immune response against tumour challenge. The implications of these findings are discussed. Caution is advocated in applying the results of experiments with such animal tumour virus models to the human clinical situation.