bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sequential electron microscopical study of experimental mouse skin carcinogenesis
Authors: Tarin D. 
Published: February 2007

AbstractElectron microscopical study of experimentally induced skin tumours was undertaken. The investigation was designed to determine the sequence of morphological changes between first painting with a carcinogen (methylcholanthrene) and the development of invasive neoplasms. It was found that changes occurred in both the epidermis and the dermis but that the most profound disturbances affected the region of the dermoepidermal junction.The epidermal changes corresponded to those described by previous investigators. Changes in dermal organization appeared by the end of the second week. These consisted mainly of a decrease in the size of collagen fibres and a relative increase in connective tissue ground substance. There was also an increase in the dermal cell population, many of the new arrivals being mast cells. Examination of the dermo‐epidermal junction revealed that the basement membrane was thickened and in several places had separated slightly from the basal epidermal cells.After five to six weeks' painting, small gaps appeared in the basement membrane. These were accompanied by the accumulation of fragmented material, similar in consistency to the basement membrane, in the superficial dermis. Where this material lay close to mast cells it appeared to coalesce to form reduplicated basement membranes.By the time papillomas appeared, reduplication of the basement membrane had ceased and basement membrane material was decreasing. The dermal aspects of the basal cells pushed out cytoplasmic projections into the connective tissue. These projections constricted and separated from the cell to produce free‐lying vesicles in the superficial dermis. Later the vesicles ruptured and the release of their contents was associated with destruction of small areas of surrounding connective tissue. These appearances suggested enzymatic destruction of dermis by epidermis.The dermo‐epidermal junction of carcinomas showed similar but more pronounced changes of which complete absence of basement membrane, vesicular activity of basal cells and gross disorganization of surrounding connective tissue were the most characteristic features.Preliminary studies indicated that similar changes occur in spontaneous and experimentally induced breast tumours.
Enhancement of lung adenoma formation by neonatal thymectomy in mice treated with 7,12‐dimethylbenz(a)anthracene or urethan
Authors: Trainin Nathan , Linker‐Israeli Mariana , Small Myra , Boiato‐Chen Louise 
Published: February 2007

AbstractThe influence of neonatal thymectomy on lung adenoma formation in mice was investigated. SWR and Swiss mice thymectomized at 3 days of age and given a single dose of 7,12‐dimethylbenz (a) anthracene (DMBA) or urethan showed significantly higher incidences of tumors than did intact controls, when examined at various intervals after the carcinogenic treatment. These differences in the yield of tumors were manifested as early as 10 weeks after urethan administration. Levels of hemolysins and hemagglutinins in response to sheep erythrocytes were decreased in thymectomized mice as compared with normal animals.The probable relationship between enhanced susceptibility to chemical carcinogens and immunological deficit of neonatally thymectomized mice is discussed.
Chronic ethanol ingestion and the hepatocarcinogenicity of N‐hydroxy‐N‐2‐fluorenylacetamide
Authors: Yamamoto R. S. , Korzis J. , Weisburger J. H. 
Published: February 2007

AbstractThe effect of long‐term administration of 10% and 20% ethanol solutions on the hepatocarcinogenicity of N‐hydroxy‐N‐2‐fluorenylacetamide in two strains of rats was investigated. In tests with ethanol and carcinogen, started with 4‐ to 6‐week‐old Fischer rats the size of the liver and the extent of tumor formation were slightly less with male rats, and slightly more with females, as compared to rats fed only carcinogen. Experiments beginning with 16‐week‐old males, or with ethanol following carcinogen, were without additional effect. In NIH black rats, less susceptible to carcinogen and with a longer experimental period of 64 weeks, the concurrent intake of 10% ethanol did not affect the liver tumor incidence, although in females there seemed to be fewer cholangiomas and more hepatomas.
Iron‐dextran carcinogenesis in rats: Influence of dose on the number and types of neoplasm induced
Authors: Roe F. J. C. , Carter R. L. 
Published: February 2007

AbstractGroups of 16, 32, 64 and 128 male CB Wistar rats were given, respectively, 16, 8, 4 and 2 subcutaneous injections of 0.75 ml iron‐dextran (“Imferon”) at weekly intervals: 64 untreated rats served as controls. Injection site tumours arose in 8, 11, 7 and 8 rats, respectively, in the four groups treated with iron‐dextran. The average time of tumour induction was similar in the four test groups but the grade of malignancy of tumours was directly related to the total dose of iron‐dextran administered. The wider implications of this latter observation are briefly discussed. The incidence of tumours at locations distant from the injection site was higher in the 128 rats which received only two injections of iron‐dextran than in the 64 untreated controls. However, the risk of dying with a distant tumour was not statistically higher in the combined test groups than in the control group. Several of the distant neoplasms in the iron‐dextran treated animals were of unusual types but their relationship to treatment with iron‐dextran remains uncertain.
The effect of isonicotinic acid hydrazide on the development of tumors
Authors: Toth Bela , Rustja Marjan 
Published: February 2007

AbstractIsonicotinic acid hydrazide (INH) was administered as a 0.1% solution in the drinking water for the life span of adult AKR inbred mice. The treatment resulted in no significant inhibitory effect on the development of malignant lymphomas which are characteristic of these animals, nor did it induce other tumors.Similar administration of INH as 0.05 and 0.15% solutions to adult randomly bred Swiss mice enhanced the formation of pulmonary adenomas, while it had no apparent inhibitory influence on the progression of other types of tumors.Single doses of 500, 400, 300, 250, 200 and 100 μg of INH were injected subcutane‐ously on the day of birth to Swiss mice, without significant tumorigenic effect.The problem of tumor induction versus inhibition is discussed.
Selective chemotherapy in relation to the site of tumor transplantation
Authors: Donelli M. G. , Rosso R. , Garattini S. 
Published: February 2007

AbstractSarcoma 180 and Ehrlich carcinoma maintained in the ascitic form were transplanted subcutaneously, intraperitoneally and intracerebrally. The same tumor transplanted in different sites showed a different sensitivity to the same chemotherapeutic agent. Cyclophosphamide and sarcolysin were active on subcutaneous and intraperitoneal, but not on the intracerebral tumors. On the other hand, I‐methylnitrosourea was effective only on the tumors transplanted intracerebrally.
Two established in vitro cell lines from human mesenchymal tumours
Authors: Ponten Jan , Saksela Eero 
Published: February 2007

AbstractThe development and cultivation of two cell lines from human mesenchymal tumours is described. Lines 2T and 4T differed from normal human fibroblastic cell strains by showing cytological atypia (high nucleocytoplasmic ratio, hyperchromasia and pleo‐morphism), an altered “epithelial‐like” pavement growth pattern, a deficient inhibition of cell division in crowded cultures and a potential for “indefinite” multiplication in vitro. Both lines were chromosomally abnormal in all samples and differed karyo‐typically from any known continuous cell line as well as from each other. Line 2T has retained, at least for 3 months (passage 111–126), a fairly narrow chromosomal mode of 34–38 with two specific marker chromosomes. A high frequency of chromosome breakage was observed in line 2T and extensive chromosome fragmentation, “chromosome pulverization”, occurred. No viruses could, however, be detected in the cultures despite numerous attempts. A control cell strain (2S) was developed from uninvolved skin of one of the tumour patients. Its behaviour followed the general pattern of human diploid cell strains in culture. To our knowledge, the described cell lines are the first derived from human mesenchymal tumours where the availability of a control fibroblast strain will provide us with opportunities to compare autologous normal and neoplastic human mesenchymal cells under in vitro conditions.
RNA with high template activity from leukaemic myeloblasts (Bai strain a virus‐induced avian myeloblastosis) II. Sedimentation profiles of template activity and of rapid 32P labelling
Authors: Veprek L. , Trávníček M. , Ríman J. 
Published: February 2007

AbstractRNA preparations made from leukaemic myeloblasts by fractionating extraction in a two‐phase system with phenol‐0.1 M sodium acetate (pH 6.0), using successively increasing temperatures, were analyzed by centrifugation in a sucrose gradient. The RNA of the individual fractions was precipitated with soluble RNA as carrier, and the template activity of the fractions was determined in a subcellular protein‐synthesizing system from E. coli. Distribution of rapidly labelled material in similar preparations 2 h after an intravenous administration of 32P‐orthophosphatewas also investigated.A comparison of the sedimentation profiles obtained showed that cytoplasmic RNAs extracted at 25°C showed only low template activity in the region of 15–30S. Preparations isolated at 45°C contained the two precursors of ribosomal RNA, 45S and 35S, exhibiting a pronounced template activity. The final extraction at 65°C yielded preparations of messenger RNA of outstanding purity, their main component sedimenting in the region of 18S and another significant portion sedimenting heterogeneously over a wide range from 18 to 50S.In the presence of all the cofactors required for protein synthesis, RNA extracted at 65°C was able to bind one or more E. coli ribosomes. At the same time, this RNA was rapidly degraded.
Studies on bladder carcinogens in the human environment I. Naphthylamines produced by pyrolysis of amino acids
Authors: Masuda Yoshito , Mori Kazuko , Kuratsune Masanori 
Published: February 2007

AbstractL‐Glutamic acid and L‐leucine were pyrolyzed at 500°C and 700°C in a nitrogen atmosphere and the resulting pyrolyzate was analyzed for 1‐ and 2‐naphthylamines by column, paper, thin‐layer, and gas chromatography. From 100 g of L‐glutamic acid pyrolyzed at 700 °C, 1.3 mg of 1‐naphthylamine and 0.13 mg of 2‐naphthylamine were isolated, from 100 g of L‐leucine, 0.7 mg and 0.01 mg of the isomers respectively were isolated. When the amino acids were pyrolyzed at 500° C, neither 1‐ nor 2‐naphthylamine was found.
Observations on burkitt's tumour in central and Northern Canada
Authors: Hoogstraten Jan 
Published: February 2007

AbstractThe commonest childhood lymphoma in Central Canada is histologically, anatomically, and clinically identical to Burkitt's tumour. There is as yet no documented evidence that the incidence of this neoplasm is significantly higher in Africa than in Manitoba.This form of lymphosarcoma is not temperature and humidity dependent as was previously assumed, the most recent example being observed in an Eskimo child from the North West Territories.This neoplasm may masquerade as metastatic neuroblastoma, leukaemia, or even Ewing's tumour. The presence of large phagocytic histiocytes along with undifferentiated tumour cells in marrow aspirates during life may be of diagnostic assistance.This neoplasm, like other conventional forms of lymphosarcoma, can be multicentric in origin. While this neoplasm can infiltrate or even originate within bone marrow and be associated with circulating tumour cells, it should not be considered as a variant of leukaemia.
Implications of animal cancers to human neoplasia: Epidemiologic considerations
Authors: Tjalma R. A. 
Published: February 2007

AbstractWide variation in biologic and ecologic characteristics of the various animal species suggests opportunity for unique epidemiologic study of cancer; such studies may be designed to capitalize on species differences which permit the effective segregation and evaluation of factors suspected in the etiology of cancer in all species, including man. Epidemiologic exploitation of animal cancer models in the interests of the human problem is limited by the quality and quantity of disease occurrence and risk population data. The automated, nomenclature‐based Veterinary Medical Data Program of the National Cancer Institute (USPHS) has been adopted by a number of institutional veterinary college hospitals in the US and Europe, and serves as a source of detailed information on the occurrence of animal diseases seen at the participating facilities. Utilization of the case history relative‐odds study design promises to facilitate epidemiologic investigation of cancer in animals. Reported clusters of bovine lymphoma in dairy herds are unexplained and currently under study in an effort to evaluate possible genetic and viral factors. The analytic complications characteristic of human cancer cluster investigations are compounded in the case of animal cancer cluster studies. While a postulated relationship between the occurrence of cancer in man and animals is academically attractive, no such association has been demonstrated to date. Epidemiologic investigation of animal cancer models, while warranted and possible, must be designed so as to meet with limitations of available data.
Ganglions interpectoraux et cancers du sein. Interpectoral lymph‐nodes and breast cancer
Authors: Vogt‐Hoerner G. , Contesso G. 
Published: February 2007

AbstractRotter's group of interpectoral lymph‐nodes was found in 46% of altogether 530 patients subjected to radical mastectomy. In 12%—a by no means negligible figure—these lymph‐nodes had been invaded by cancer cells.Invasion of the Rotter chain is almost always linked with invasion of the axillary or internal mammary chains. There is a direct correlation between tumour size and invasion of the Rotter chain. Tumours of the left half of the breast give rise to metastases in the interpectoral chain more commonly than tumours located on the internal or central aspects of the breast.
Cytological study with reference to malignancy on clonal cell lines of a mouse fibrosarcoma
Authors: Ranadive Kamal J. , Ganguly B. , Mashelkar B. N. 
Published: February 2007

AbstractSeveral clonal and subclonal cell lines have been developed from a low tumorigenic Swiss mouse sarcoma cell strain MFS8 in its 200th passage of cultivation. Clonal line 3 (Cl3) and its subclone 20 (SCl20) are the only cell lines that developed tumours on inoculation into the same strain host. These two malignant clones are therefore compared with their non‐malignant sister clones derived from the same parental stock.Significant differences were noted in the biological characters of malignant and non‐malignant clones. Both malignant clones displayed high growth rate, higher morphologic and cytologic uniformity, a more homogeneous set of marker chromosomes (90%) with consistency in the occurrence of special dicentric marker “A” and lower frequency of mitotic abnormalities as against the sister clones. The stem line number of chromosomes was also in the narrowest diploid range and mitotic abnormalities were least in the malignant clones. Much better balance and uniformity of biological characters and better viability in vitro were thus observed in the tumour‐producing clonal lines as compared with the non‐tumour clonal lines. The significance of the data is discussed.
Light and electron microscopic studies on a transplantable thyrotrophic pituitary tumor in the mouse
Authors: Schelin U. , Lundin P. M. 
Published: February 2007

AbstractA transplantable pituitary tumor induced in a male C57Bl mouse by radiothyroidectomy has been studied by light and electron microscopy.The primary tumor was highly differentiated and composed of hypersecretory cells which showed the morphological characteristics of the thyroidectomy cell.The tumor was followed through four transfers in radiothyroidectomized hosts. Autonomous tumors growing in normal hosts appeared during the fifth transfer generation.The first dependent tumor grafts showed highly differentiated cells of the same appearance as the primary tumor cells. Through the following transfers there was a progressive dedifferentiation of the tumor cells although the majority of them could, in the electron microscope, be identified as thyrotrophic tumor cells with morphological signs of secretory function.In the autonomous tumors most of the cells were dedifferentiated and only a few cells showed signs of secretory function.The results of the morphological study support earlier observations on the hormone activity of transplantable thyrotrophic tumors. These have shown that primary and dependent tumors are highly functional, but that autonomous tumors display a progressive decrease in hormone production.The findings also confirm earlier morphological observations that autonomous tumors are dedifferentiated, but both the light and electron microscopic observations in this study suggest that there is a progressive dedifferentiation of tumor cells in hormonedependent tumors as well.
The functions of membranes in neoplastic cells partially resistant to thiotepa
Authors: Barton A. A. , Barton Mary 
Published: February 2007

AbstractThiotepa causes alterations in the structure of the cytoplasmic matrix and the rapid formation of membranes. These provide the means by which the altered matrix is voided from the cell. It is suggested that this form of excretion is the method by which cells are able to resist the antineoplastic action of alkylating agents.
Hepatocarcinogenicity of the herbicide maleic hydrazide following parenteral administration to infant Swiss Mice
Authors: Epstein Samuel S. , Mantel Nathan 
Published: February 2007

AbstractRandom‐bred infant Swiss mice were injected subcutaneously with maleic hydrazide in aqueous solution or tricaprylin suspension in varying doses. Maleic hydrazide in excess of 0.5 mg on the first day of life was lethal. Following a total maleic hydrazide dosage of 55 mg in the first 3 weeks of life, there was a high incidence of hepatomas, 65% of 26 male mice alive at 49 weeks, in contrast to solvent controls, 8% of 48 male mice. On the basis of these data, it is necessary to consider the possibility of carcinogenic hazard to man due to exposure to maleic hydrazide residues in root crops and tobacco.
MODIFICATIONS DU MÉTABOLISME GLUCIDIQUE DANS LE FOIE EN VOIE DE CANCÉRISATION PAR LE DIMÉTHYLAMINOAZOBENZÈNE I. RECHERCHES AU NIVEAU DU CYCLE DU GLYCOGÈNE
Authors: Meunier Michèle , Jacob Arlette 
Published: February 2007

AbstractIn an attempt to find an explanation for the hypoglycaemia observed in rats with DAB‐induced hepatomas, we studied glycogen metabolism in rat livers in which cancer invasion proceeded at different speeds.We measured the content of glycogen and of glucose‐6‐phosphate in the liver and determined the activities of glycogen‐synthetase, phosphorylase, and phosphoglucomutase.We demonstrated that the cause of the hypoglycaemia varies from one case to another. In some instances, glycogen accumulates in the liver but can no longer be broken down into glucose, while in others glycogen is no longer synthesized.
In vitro studies of immune reactions against autochthonous and syngeneic mouse tumors induced by methylcholanthrene and plastic discs
Authors: Hellström Ingegerd , Hellström Karl Erik , Pierce George E. 
Published: February 2007

AbstractA colony inhibition (CI) technique was used to demonstrate lymph node cell (LNC) and serum‐mediated immune reactions against specific transplantation antigens of mouse sarcomas which were induced by methylcholanthrene (MCA) or by plastic disc implantation. Lymph node cells from mice whose primary MCA sarcomas had been removed 3–8 days before the test strongly reduced the plating efficiency of autochthonous target tumor cells. An approximately equal reduction was also obtained with LNC from mice with progressively growing MCA sarcomas or from those which had been inoculated once with untreated or heavily X‐irradiated (15,000 R) sarcoma cells. Cytotoxic antibodies were infrequently detected in serum from these mice.Repeated immunization with heavily irradiated tumor cells appeared to increase the level of cytotoxic humoral antibodies but did not augment the LNC‐mediated immune reactions.
Delayed hypersensitivity to extracts from primary sarcomata in the autochthonous host
Authors: Wang Mildred 
Published: February 2007

AbstractAll rats with benzpyrene‐induced primary tumours responded by producing varying degrees of delayed hypersensitivity reactions to their own tumour extracts after the complete removal of the tumour. After partial removal of the tumour the delayed hypersensitivity reactions were uniformly shown to be negative. Gradual increase in delayed hypersensitivity response as shown by the gradual increase in foot‐pad swelling was detected after each successive tumour transplant and excision in the same animal. The delayed hypersensitivity phenomena are not specific to each individual tumour and there appears to be almost complete cross‐reactivity. The possible reasons for these observations are discussed.
Altered properties of fujinami‐virus‐infected duck cells and murine sarcoma virus‐infected rat cells
Authors: Temin Howard M. 
Published: February 2007

AbstractA comparison was made of the properties of uninfected and Fujinami‐virus‐infected duck cells, uninfected and Murine Sarcoma virus‐infected rat cells, and uninfected and Rous Sarcoma virus‐infected chicken cells. It was found that alteration in cell shape, increased glycolysis in the absence of serum, and a decreased requirement of serum for multiplication and for glycolysis were constant correlates of the neoplastic conversion brought about by these RNA sarcoma viruses.
Studies on a naturally occurring human antibody active against mouse landschutz ascites tumor cells III. The nature of the antigenic site on the tumor cell
Authors: Laskov R. , Simon E. , Gross J. 
Published: February 2007

AbstractGalactose and galactose‐containing sugars were found to have an inhibitory effect on the cytotoxic and agglutinating activity of human serum against Landschutz ascites tumor cells. This suggested that D‐galactose may be an essential part of the tumor cell antigenic site involved.The pattern of inhibition by the various sugars resembled that of the human blood group B system. However, absorption experiments showed that, while the mouse tumor cells had sites which bind anti‐B, the latter was different from the cytotoxic antibody, and did not participate significantly in the cytotoxic reaction.From the differing patterns of sugar inhibition for sera of the various human blood groups, there were indications that the cytotoxic activity may be due to a group of antibodies of slightly differing sugar specificities.The cytotoxic agent could be absorbed by heat‐killed ascites tumor cells and eluted thereafter, using certain galactose‐containing sugars as eluting agents. These experiments confirmed the hapten‐like nature of D‐galactose in this system.Sugar and non‐sugar eluates prepared from antibody‐coated tumor cells were found to contain two types of immunoglobulins—a large amount of IgG, and a very small amount of IgM. The cytotoxic activity was demonstrated to reside exclusively in the IgM fraction.