bluuebunny/crossref_metadata_2025 huggingface dataset:
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

RNA 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

L‐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

The 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

Wide 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

Rotter'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

Several 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

A 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

Thiotepa 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

Random‐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

In 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

A 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

All 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

A 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

Galactose 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.
Endocrine factors in the development of transplantable adrenal cortical tumors. I. Inhibition of the growth rate by corticotropin (ACTH)
Authors: Fiala Silvio , Fiala Anna E.
Published: February 2007

The growth rate of transplantable adrenocortical tumors in male LAF 1 mice was found to be inhibited in hypophysectomized and in adrenalectomized animals. Castration and sex hormones did not affect the growth of these tumors. In intact mice a striking inhibition of the growth rate of adrenocortical tumors was brought about by the administration of ACTH. Evidence was obtained that ACTH inhibited growth by a direct action on the tumor cells. When expressed in terms of units of DNA, the biochemical and cytochemical effects on adrenocortical tumor cells appeared qualitatively similar to the effects of this hormone on the normal adrenal cortex. A single injection of ACTH stimulated the activity of glucose‐6‐phosphate dehydrogenase. Repeated administration of ACTH produced an increased oxygen uptake by sliced tissue and a moderate accumulation of RNA in the microsomal fraction. Water extracts of acetone powdered, ACTH‐treated, adrenocortical tumors had lower dCMP‐deaminase activity than extracts from untreated tumors. When expressed in terms of units of DNA, the homogenates of ACTH‐treated adrenocortical tumors had a higher succinoxidase activity and the sliced tissue had a lower rate of anaerobic glycolysis than did corresponding samples of untreated adrenocortical tumors.
Transformation of newborn hamster cells with simian adenovirus SA7
Authors: Whitcutt J. M. , Gear J. H. S.
Published: February 2007

Newborn Syrian hamster skin cells can be transformed in vitro by simian adenovirus SA7. The transformation occurs within 6–8 days of treatment with virus and the transformed cells give rise to tumour development when they are re‐inoculated into weanling hamsters.
Dose‐dependent recognition of irradiated isogeneic mouse lymphoma cells: Study by terminal dilution assay
Authors: Maruyama Yosh
Published: February 2007

The radiation response of an isologous mouse lymphoma was studied in detail by means of the TD50 method in irradiated and unirradiated recipients. The contribution of host resistance to radiosensitivity was shown to be similar to that determined earlier by the SD50 method, and produced significant alteration in survival curve shape. Assay by TD50 did not show significant differences when 0 R, or 100 R irradiated cells were assayed in pre‐ or non‐irradiated recipients. At 1,000 R or larger radiation doses, TD50 doses differed significantly. The recognizability of the irradiated cell increases with dose, suggesting that in addition to an alteration in cell growth and changes in numbers of killed cells, the absorbed irradiation may also have exposed the antigenic sites of surviving irradiated cells.
Immunologic studies on graffi‐virus‐infected spontaneous gross leukemia of akr mice
Authors: Micheel B. , Pasternak G.
Published: February 2007

Spontaneous AKR Gross leukemias permanently produced Graffi virus if the cells had been repeatedly passaged in Graffi‐virus‐infected mice. Only one of 10 Graffi‐virus‐infected Gross leukemias investigated appeared to be immunologically indistinguishable from Graffi leukemias. Its cells contained the Graffi‐virus‐induced surface antigens as demonstrated by the phenomenon of tumor‐specific transplantation resistance in vivo and by immunofluorescence and absorption tests in vitro. The original leukemias transplanted independently did not contain these antigens.

All other superinfected Gross leukemias were resistant to the rejection response of animals immunized against Graffi leukemia. Weak positive reactions in the immunofluorescence test indicated the presence of certain Graffi‐virus‐induced antigens at their cell surface. In addition, the cells absorbed virus‐neutralizing antibodies from Graffi‐immune sera. Absorbed sera still contained antibodies against surface antigens of Graffi target cells. It is suggested that Graffi leukemia cells as well as one of the Graffi‐virus‐infected Gross leukemias tested contain viral and virus‐induced new cellular antigens while the other infected Gross leukemias contain only viral antigens.
The differential action of neonatal thymectomy in mice infected with murine sarcoma virus‐harvey (msv‐h)
Authors: East June , Harvey Jennifer J.
Published: February 2007

Intact C3H/Bi and BALB/c mice infected with Murine Sarcoma Virus‐Harvey (MSV‐H) at 3–16 days developed either „early”︁ erythroblastic splenomegaly with concomitant severe anaemia and sarcomas at sites related to the route of inoculation or, after a perceptible delay, „late”︁ lymphocytic leukaemia. These effects were dependent on the dilution of the virus and the age of the recipients. Neonatal thymectomy both accelerated the erythroblastosis and increased the tumour incidence in older 14–16 day recipients but prevented (or indefinitely postponed) the lymphocytic leukaemia. This differential action of neonatal thymectomy is discussed in the light of current immunological theory. A virus causing only lymphocytic leukaemia was separated by passage from the plasma of leukaemic intact or non‐leukaemic thymectomized mice. Thus, in these experiments, MSV‐H behaved as a complex of two viruses, one causing the early changes and a second, always present in higher concentration but slower acting, responsible for the late changes.
Relationships of chromosomal and pathological findings in rous sarcoma virus‐induced tumours in the mouse
Authors: Mark J.
Published: February 2007

Sarcomas were induced in CBA mice by RSV‐SR inoculated in the neonatal period. The latent period ranged from 21 days up to more than 2 years; the peak incidence occurred around 4–5 months. The tumour incidence was about 45% after 6 months and nearly double after two years of observation. Multiple tumours, usually with closely similar latent periods, were frequent. Among the sarcomas studied chromosomally, small size, slow growth and a high degree of histological maturity were interconnected factors correlated with the occurrence of a normal diploid stemline. Opposite characteristics were typical of the sarcomas with a numerically and structurally changed stemline, especially the tetraploid group.

Metastases were found only in the lungs and they occurred in approximately one‐third of the cases. No cysts were observed in the lymph nodes but a few instances are on record with cysts in the spleen and in the neighbourhood of the pancreas, as well as in connection with the sarcomas. A large amount of acid mucopolysaccharides could be found in all tumours studied in this respect.

By back‐transfer to chickens, Rous sarcomas were elicited by roughly 75% of the mouse sarcomas investigated. Nearly all the negative mouse tumours had a latent period of more than one year.
Tumor fluid thromboplastin activity
Authors: Frank Arthur L. , DouglasHolyoke E.
Published: February 2007

The thromboplastin activity of T‐241 Lewis sarcoma peripheral fluid and control subcutaneous fluid in C57BL/6Ja male mice was measured, using a calcium reconstitution assay. The material was collected in Millipore filter chambers.

At low dilutions of the collected material there was a statistically significant increase in clotting activity of the tumor peripheral fluid. The calcium ion concentration of the collected fluid was also measured. It was also noted that gels were found more frequently, and in larger amounts, in the chambers in tumor‐bearing animals than in the controls.
Anchorage and growth regulation in normal and virus‐transformed cells
Authors: Stoker Michael , O'Neill Charles , Berryman Susan , Waxman Vivienne
Published: February 2007

Many cell types will grow when attached to a rigid surface but not in suspension, a phenomenon termed „anchorage dependence”︁. Anchorage dependence can be studied by incorporating solid particles of varying size into gels. It has been found that colonies will form on glass fibrils 500 μ in length, but not in the presence of silica fragments smaller than the cells. This shows that the suspending medium is not itself inhibitory, and confirms the requirement for a rigid surface of adequate size.

The state of inhibited cells in suspension culture was examined by dispersing them in a methyl cellulose gel, in vessels lined with agar. In this system aggregation is prevented and the cells may be recovered quantitatively. Normal, as well as transformed, cells increase in size, and a proportion synthetize DNA during the first 24 hours in suspension culture. Growth and DNA synthesis in normal cells then virtually cease, while transformed cells continue to grow into colonies. The stationary normal cells remain competent for further growth for at least a week in suspension. When such cells are allowed to attach to a rigid surface in the presence of colchicine, DNA synthesis occurs and is followed by mitosis. These results indicate that suspended cells are blocked between mitosis and the end of the S phase of the cycle.
Accumulation of labelled vitamin B12 in some transplanted tumours
Authors: Flodh Hans , Ullberg Sven
Published: February 2007

The accumulation of labelled vitamin B12 in four different kinds of transplanted tumour was studied using whole‐body autoradiography and impulse counting. The tumours were 90Sr‐induced soft fibroblastic osteosarcomas, spontaneous mammary carcinomas, Ehrlich ascites and Moloney virus‐induced tumours. The 90Sr‐induced soft sarcoma, which was the most rapidly growing tumour, showed the greatest uptake of radio‐B12, the concentration being higher than in any normal tissue. In all tumours the radioactivity was localized to the peripheral, still actively growing parts. It is suggested that a connection exists between growth rate and accumulation of B12 and that B12 is needed for rapid cell multiplication.
Morphology of tumors induced in Hamsters by Simian adenoviruses
Authors: Levenbook I. S. , Chigirinsky A. E. , Tsetlin E. M. , Dodonova N. N. , Altstein A. D.
Published: February 2007

Subcutaneous hamster tumors induced by Simian adenovirus SA7, strains C8, B105 and C626, were found to be poorly differentiated sarcomas having morphological features which distinguish them from tumors induced at the same site by papovaviruses and the Rous sarcoma virus. In general, the adenovirus‐induced tumors were morphologically alike, C8‐induced sarcomas showing some differences. Tumors induced by this strain in the subcutaneous tissue, muscles, peritoneum and mediastinum were morphologically identical. Tumors found in the brain were mainly malignant ependymomas and choroid plexus carcinomas, generally originating in neuroectoderm.

The oncogenicity of adenovirus SA7 (C8) in meso‐ and ectodermal cells has thus been demonstrated.
Rǒle de l'Immunité dans le Rejet des Tumeurs Induites par le Virus MSV. Effet des Sérums Antithymocytes
Authors: Varet B. , Lévy J. P. , Leclerc J. C. , Senik A.
Published: February 2007

The rǒle of immunity in the rejection of tumours induced by the MSV virus. The effect of antithymocyte serums

Rabbit anti mouse lymphoïd cell serum (ALS) facilitated the outgrowth of virus‐induced Rhabdomyosarcoma (MSV) in adult BALB/c and C57Bl/6 mice.

Whereas all tumors induced in control mice completely regressed, most of the tumors induced in ALS inoculated mice grew progressively and killed the host. Frequency of positive mice was also greatly increased. Lymphocytes of mice immunized against MSV were able to inhibit the outgrowth of transplanted Moloney lymphoma cells. These experiments showed that spontaneous rejection of MSV induced tumors in adult mice is an immunological phenomenon mediated by immune lymphoïd cells.

The rǒle of cellular immunity and antibody in tumor rejection are briefly discussed.
Further electron microscopic studies on the mechanism of carcinogenesis: The specificity of the changes in carcinogen‐treated mouse skin
Authors: Tarin D.
Published: February 2007

This work was undertaken to determine if the ultrastructural changes seen in mouse skin carcinogenesis (Tarin, 1967a) are specific to the carcinogenic process.

Electron microscopic examination of skin treated with non‐carcinogenic irritant chemicals (benzene, turpentine) showed that the dermo‐epidermal junction remained intact. The changes seen in this region in methylcholanthrene‐treated skin were not present.

The irritants did, however, produce changes in the epidermis and dermis but these differed from those seen in carcinogen‐treated skin. The epidermis underwent regular hyperplasia and there was an increase in the number of inflammatory cells in the dermis. Dermal collagen fibre structure and arrangement were not altered.

It is concluded that the changes seen at the dermo‐epidermal junction in carcinogen‐treated skin are directly related to the carcinogenic process and are not the result of non‐specific irritation.

The nature of the carcinogenic process is considered and disturbance of interaction between epithelium and connective tissue is offered as an explanation for the behaviour of neoplastic tissue. This hypothesis is discussed in the context of modern work which has shown that such interactions are of importance in the development and maintenance of normal tissue architecture.
Effect of herpes simplex virus on human embryonic cells latently infected with reovirus type 3
Authors: Bell Thomas M. , Munube Germano M. R. , Griffin E. R.
Published: February 2007

A persistent latent infection of human embryo fibroblasts by reovirus type 3 was found to be due to the continuous infection of a small proportion of the cells. Super‐infection of these cultures by herpes simplex virus resulted in the destruction of the monolayers by the herpes virus without any obvious signs of interference.

Electron microscopic examination of these doubly infected cultures showed the presence of multi‐nuclear blebs and an unusual, “condensed‐mass”, form of intranuclear herpes virus. The implications of these findings are discussed.
The stimulating effect of complete Freund's adjuvant on tumour induction by polyoma virus in mice and By Rous sarcoma virus in rats
Authors: Ter‐Grigorov V. S. , Irlin I. S.
Published: February 2007

Complete Freund's adjuvant was shown to greatly stimulate viral oncogenesis both in the case of polyoma virus in mice and in the case of Rous sarcoma virus in rats. Tumours appeared in 74% of CC57BR/Mv mice infected when newborn with polyoma virus — adjuvant emulsion, whereas control mice injected with virus alone failed to develop tumours. Rous virus (Carr‐Zilber strain) and adjuvant when administered together as emulsions to Wistar rats (newborn or sucklings as well as 2.5‐month‐old animals) resulted in a 100% tumour incidence. In control animals treated with the virus alone when 0–4 days old, tumour incidence was no more than 30–40%; no tumours appeared in control animals which received virus alone when they were more than 2 weeks old. A significant stimulating effect of Freund's adjuvant was also revealed when the virus was inoculated into 4‐ to 15‐day‐old rats which received adjuvants as neonates. Thirty per cent of rats given virus — adjuvant emulsion produced measurable quantities of complement‐fixing antibodies to soluble antigens of Rous sarcoma, while in animals given virus alone such antibodies were not demonstrable. It is suggested that the stimulating action of complete Freund's adjuvant on polyoma and Rous oncogenesis is based upon a mechanism similar to the classical “enhancement phenomenon”.
Lymph‐node metastases after intratibial transplantation of tumors
Authors: Franchi G. , Innocenti I. Reyers‐Degli , Rosso R. , Garattini S.
Published: February 2007

Ehrlich carcinoma and Sarcoma 180 implanted in the marrow cavity of the tibia induced the formation of visible metastases in distal lymph nodes to a larger extent than when they were implanted in the leg muscles. Differences in survival time or in tumor growth did not explain this difference in metastasis formation. Immediately after transplantation, cancer cells were seen in the blood of animals implanted intratibially but not of those implanted intramuscularly. However, this effect per se was not important because amputation of the leg after the end of the early dissemination completely prevented the development of metastases.
Positively charged groups at cell surfaces
Authors: Weiss L. , Bello J. , Cudney Toni L.
Published: February 2007

An attempt was made to identify positively charged amino‐groups at the electrokinetic surfaces of human and mouse erythrocytes, cultured cells derived from a human osteogenic sarcoma, and murine ascites sarcoma 37 cells. Following reactions of these cells with formaldehyde, 2,4,6‐trinitrobenzenesulfonic acid; 2‐chloro‐3,5‐dinitropyridine or 2‐chloro‐3,5‐dinitrobenzoic acid, no consistent change in their electrophoretic mobilities was observed. If a number of positively charged groups commonly associated with proteins had been present at the cellular electrokinetic surface, their reaction with the various reagents would have resulted in an increase in net surface negativity. We therefore conclude that these groups are not present at the surfaces of the cells studied.
Histologic types of gastric carcinoma in high‐ and low‐risk areas
Authors: Muñoz Nubia , Correa Pelayo , Cuello Carlos , Duque Edgar
Published: February 2007

A total of 322 cases of gastric cancer from the surgical material of the Pathology departments of three cities in Colombia and of Mexico City were divided according to the histologic classification of Laurén into two main histologic types: intestinal and diffuse. The intestinal type was predominant in high‐risk areas for stomach cancer, while the diffuse type was more frequent in the low‐risk areas. Data presented suggest that these two main histologic types may be connected with different precancerous lesions as a significant proportion of the intestinal type carcinomas arose from intestinal metaplasia of the gastric mucosa, while the diffuse type showed no such origin. The significance of these findings in relation to the genesis of stomach cancer is discussed.
Transformation of foetal human leukocytes in vitro by filtrates of a human leukaemic cell line containing herpes‐like virus
Authors: Pope J. H. , Horne M. K. , Scott W.
Published: February 2007

Transformation of foetal human leukocytes followed inoculation with a filtrate of cells of the QIMR‐WIL human leukocyte cell line, previously shown to carry a herpes‐like virus. Proliferation of leukocytes was generally noted 24–35 days after inoculation, and resulted in the establishment of cell lines resembling those derived from peripheral leukocytes of patients with leukaemia or infectious mononucleosis. The sex of representative transformed lines confirmed that they were of foetal origin. Transformation occurred with two separate filtrates of QIMR‐WIL cells, with leukocytes from five individual foetuses, and with leukocytes from bone marrow, thymus and spleen. Various control inocula gave negative results, including culture medium and filtrates of Raji and QIMR‐GOR cell lines. Representative transformed lines were found to fix complement with human serum known to react with QIMR‐WIL and QIMR‐GOR cells; but similar serum showed little evidence of reaction by immunofluorescence. The transformed cell lines studied appeared to be essentially diploid, and subterminal constrictions involving Group C chromosomes were noted in a small proportion of cells in 8/9 lines. In preliminary studies, the transforming factor was found to be sensitive to heat and ether, was sedimented at 70,000 × g and retained by a filter of APD 50 mμ; these results are compatible with the herpes‐like virus of the QIMR‐WIL cells being the transforming factor.
The properties of sarcomas induced in wistar rats by rous sarcoma virus (schmidt‐ruppin)
Authors: Harris R. J. C. , Chesterman F. C. , McClelland Rosalind M.
Published: February 2007

The properties of single cell clones derived from sarcomas induced in young Wistar rats by RSV (S‐R) are compared. Most sarcomas do not produce infectious RSV but are virogenic (i.e. capable of inducing Rous tumours) for chicks. One sarcoma was not virogenic. Clones were tested for virus release either alone in vitro or after passage on the chorioallantoic membrane of the embryonated egg. The avian sarcoma‐leukosis group‐specific (complement‐fixing) antigen could not be detected in either virogenic or non‐virogenic cells. A few primary Rous rat sarcomas showed the presence of virus‐induced transplantation antigen but this could not be detected by graft‐rejection in serially‐passed tumours, or in any of the clones.

The virogenic clones were more malignant for rats than the non‐virogenic ones, but this property was not associated with the presence or absence of virus‐specific antigens.
Oocyte destruction and ovarian tumorigenesis after direct application of a chemical carcinogen (9:10‐dimethyl‐1:2‐benzanthrene) to the mouse ovary
Authors: Krarup Torben
Published: February 2007

Ovaries of immature mice were painted with 9:10‐dimethyl‐1:2‐benzanthracene (DMBA), and the effect of the carcinogen on the number of oocytes as well as on the subsequent development of ovarian tumours was studied.

DMBA had an immediate effect on the small oocytes. Their number was rapidly reduced within the first 4 weeks after treatment, followed by a more gradual elimination, comparable to the elimination rate in the control ovaries. The growing and large oocytes were not primarily affected by the carcinogen; however, after the first 4 weeks post treatment their number was also decreased. This was considered to be secondary to the reduction in the number of small oocytes. No more oocytes remained in the ovaries of 6‐ to 9‐month‐old treated animals, an age at which considerable numbers were still present in the ovaries of control mice.

Simultaneously with the elimination of oocytes there occurred a pathological development in the ovaries. There seemed to be a positive correlation between the rate of oocyte disappearance and the pathological development: the faster the oocytes disappeared the earlier the abnormal development began. This ultimately led to ovarian tumours, only seen in ovaries totally depleted of oocytes.

It is concluded that DMBA applied to the ovaries acts directly on the small oocytes and destroys many of them. The neoplastic development is considered secondary to the reduction of the oocyte population and is apparently not caused by the carcinogen itself. This is supported by the fact that the development of ovarian tumours in mice is always preceded by a rapid disappearance of oocytes, regardless of whether the method of tumour induction in X‐irradiation, intrasplenic transplantation of an ovary after gonadectomy, treatment with a chemical carcinogen, or genetic deletion of oocytes.
Continuous production of avian sarcoma virus B77 by rat tumour cells in tissue culture
Authors: Šimkovič D. , Popovič M. , Švec J. , Grófová M. , Valentová N.
Published: February 2007

The rat tumour RBI, previously induced by injection of fowl sarcoma B77 tissue into newborn rats, was adapted to long‐term growth in tissue culture. Two cell lines, 16B177 and 17B177, were derived from the tumour. Both cell lines were capable of continuous production and release of infectious B77 virus over a period of more than two years' in vitro cultivation. The virus present in cell‐free tissue culture media induced characteristic sarcomas upon inoculation into young chicks.

Preliminary chromosomal analysis of the uncloned population of 17BI77 cells confirmed their rat origin and revealed that the hypotriploid stem‐line predominates, being represented by 59 chromosomes.
A reinvestigation of the origin of cells in grafted tumours, using the mouse T6 marker chromosome
Authors: Croft C. J.
Published: February 2007

Using a mouse chromosome marker technique, it was found that host cells were rare in transplants of a chemically induced sarcoma, and absent in a human adenovirus type 12‐induced tumour. However, host cells were found in four of nine transplants of a Moloney virus‐induced lymphoma and, in three of these, they constituted the majority of mitotic cells. The nature of the host cells, and the possible importance of the part played by infective virus particles in the continued growth of this tumour, are discussed.
A mathematical model for the age distribution of cancer in man
Authors: Cook P. J. , Doll Richard , Fellingham S. A.
Published: February 2007

Incidence data that have been collected by cancer registries in different parts of the world provide an opportunity for examining the relationship between cancer incidence and age on a wider scale and more accurately than has been possible before. In the present paper the relationship has been examined in a large group of cancers whose incidence increases progressively from young adult life into old age.

Five‐year age‐specific incidence rates between 35 and 74 years of age were recorded for 31 types of cancer (22 in men and 9 in women) in 11 populations, and the median age of each age group was used to characterize the group. The data were used to find the best fitting constants for each type of cancer in each population, in the equation:

where I is the incidence at age t, and b and k are constants. With this equation a straight line is obtained, when incidence and age are plotted on a double logarithmic scale.

On visual examination, 21% (72 out of 338) of the sets of data appeared to fit the relationship closely. In 54% (181 out of 338) the lines showed downward curvature; that is, the rate of increase with age was less than predicted by the equation; and in 25% (85 out of 338) the lines showed upward curvature. In one‐third of the total the differences were too great to be readily attributable to chance.

An alternative hypothesis was examined which postulated that the risk of cancer was determined, not by the age of the subject, but by the prevalence of carcinogenic agents and the length of time the subject had been exposed to them. The equation was then written:

where w is a constant and t‐w represents the ‘effective exposure’ between first exposure and the first appearance of cancer as a pathological entity.

The data for cancer of the prostate were found to fit the equation adequately in all 11 populations, when w was 32.5 years.

No evidence was found to suggest that the shape of the observed relationship could be attributed to attenuation of a limited pool of susceptibles.

Changes in prevalence of carcinogenic agents could account for the variation in the pattern of the observed relationship, and the conditions under which this might occur are discussed.

Differences in the estimated value of k (the power of the effective exposure time in the equation), were examined between (i) types of cancer and (ii) populations. The results were not wholly consistent but suggested that the value of k might be a biological constant characteristic of the tissue in which the cancer is produced.
Immunological studies on mouse mammary tumors. III. Surface antigens reacting with tumor‐specific antibodies in immune adherence
Authors: Nishioka Kusuya , Irie Reiko Furuse , Kawana Takashi , Takeuchi Shoshichi
Published: February 2007

Tumor‐specific antibodies reacted with an isografted ascitic form of mouse mammary tumor, MM2, with a higher sensitivity in an immune adherence test than in an immune cytotoxicity test.

Immune adherence and immune adherence inhibition tests were applied for the detection of surface antigens of MM2 tumor reacting with tumor‐specific antibodies. After treatment with ether, ethanol, methanol, ethanol‐ether mixture, acetone, chloroform‐methanol mixture, deoxycholate, triton × 100, snake venoms, phospholipase A, or heating at 100° C for 15 minutes, the MM2 cells did not react with syngeneic antibodies in immune adherence. The reactivity of the cells was not suppressed by heating at 62° C for 15 minutes after treatment with deoxyribonuclease, ribonuclease, proteinases, neuraminidase, ultraviolet irradiation or freezing and thawing.

In the immune adherence inhibition test, deoxycholate extract or triton × 100 extract of MM2 cells inhibited the immune adherence reactivity of syngeneic antibodies with MM2 cells, while the organic solvent extracts did not. This indicates that antigenic material was extractable in deoxycholate or triton × 100.

After removal of surface antigens with 0.1% deoxycholate, fractions were prepared from treated MM2 cells. Fractions precipitated at 105,000 × g (microsomal fractions) as well as fractions precipitated at 11,000 × g (mitochondrial fractions) inhibited the immune adherence reactivity of tumor‐specific antibodies with MM2, indicating that antigens were also present in these fractions.
Radiosensitivity and growth of friend leukemia virus studied with the spleen focus assay method
Authors: Axelrad A. A. , Thomson S.
Published: February 2007

Radiobiological and growth properties of a spleen focus‐forming strain of Friend Leukemia Virus (FV) have been investigated with the spleen focus assay method. The sensitivity of FV to ultraviolet light (2537 Å) and to 60Co γ‐rays was determined by irradiation of virus preparations in vitro to different doses and, at each radiation dose, measurement of the surviving fraction of spleen focus‐forming activity of the virus in SIM mice. Bacteriophage T4 mixed with the virus preparations served as internal dosimeter. It was found that for UV irradiation, the D10 of FV was 4.8 × 103 ergs/mm2. For ionizing radiation, the D10 of FV was 5.6 × 104 rads.

The multiplication of FV in vivo was investigated by measurement of virus titers in the spleen at various times following the intravenous injection of FV into SIM mice. Immediately after injection of a high dose of FV, 2–3% of the input virus reached the spleen. Its concentration then fell rapidly to a minimum at around 16 hours. Then the virus concentration in the spleen increased exponentially with a doubling time of 4–6 hours until the 5th day, when it reached a plateau lasting at least 18 days. The concentration of FV recoverable from the spleen at various times after infection was found to be related to the input dose of virus. Accumulation of virus in plasma paralleled the increase in virus content of the spleen.

Supralethal irradiation of SIM mice prior to or soon after infection by FV drastically reduced the amount of virus that could be recovered from the spleen at all times thereafter.
Concomitant immunity in hamsters bearing dmba‐induced tumor transplants
Authors: Lausch Robert N. , Rapp Fred
Published: February 2007

Hamsters bearing progressively growing DMBA‐induced tumor transplants were found to make a specific immune response to the neoplasm. This response was identified because animals bearing DMBA tumors rejected concentrations of DMBA‐transformed cells that were capable of inducing tumors in normal animals. This concomitant immunity was detectable even when the immunizing and challenge cells were inoculated simultaneously. Animals bearing DMBA‐induced tumor cell transplants were not protected against challenge with hamster cells transformed by simian papovavirus SV40, confirming the specificity of the concomitant immunity being studied.
Transmission of mammary tumor virus by female gr mice: results of egg transplantation
Authors: Zeilmaker G. H.
Published: February 2007

Pronuclear eggs and blastocysts obtained from GR mice were transferred to mammary tumor virus‐free recipients. GR hybrid offspring were obtained which developed mammary tumors and transmitted virus to foster‐nursed test mice. Eggs of GR mice contain information leading to production of mammary tumor virus and development of tumors at adult age.

Eggs of virus‐free mice were transplanted into GR mothers and the developing offspring subsequently delivered by Cesarean section. Intra‐uterine transmission of mammary tumor virus could not be demonstrated.

Mice belonging to two different strains were foster‐nursed on GR hybrid mothers. These infected mice transmitted virus by means of their milk but not via the egg.

The results are discussed and compared with observations made on transmission of leukemia viruses.
Cross‐reacting tstas in adeno 7 and 12 tumors demonstrated by 51CR‐Cytotoxicity and isograft rejection tests
Authors: Ankerst Jaro , Sjögren Hans O.
Published: February 2007

Antisera of mice hyperimmunized against syngeneic X‐irradiated adeno 12 tumor cells were tested for complement‐dependent cytotoxicity against an adeno 7 and an adeno 12 hamster tumor by a 51Cr‐cytotoxic test, developed to work on non‐lymphoid target cells. Significant isotope release above the level of release obtained after exposure to control sera was recorded with both tumors. There was no similar release from BHK‐C13 control hamster cells. The cytotoxic effect on hamster adeno 7 tumor cells was confirmed by the colony inhibition technique. Furthermore, it was demonstrated by transplantation tests in mice that the hamster adeno 7 tumor cells were immunogenic, causing an isograft immunity to adeno 12 tumors similar to that induced by adeno 12 hamster and mouse tumor cells.