bluuebunny/crossref_metadata_2025 huggingface dataset:
Demonstration of two group‐specific TSTAs in adenovirus‐induced tumors
Authors: Ankerst Jaro , Sjögren Hans O.
Published: February 2007

Infection of mice and rats with any one of five tested human adenovirus types belonging to groups A and B (types 3, 7, 12, 18 and 31) induced an immunity to the TSTAs of type 12 tumors as detected by the colony inhibition (CI) test. No immunity was found against an adenovirus type 1 tumor. Two adenovirus types belonging to group C (types 1 and 5) were similarly tested and found to induce a clear‐cut immunity to the adenovirus type 1 tumor but not to tumors induced by adenovirus of groups A and B. The only tested virus type of group D (type 4) did not induce any clear‐cut immunity to either adenovirus 12 tumors or the adenovirus 1 tumor. Immunization of rats with rat adenovirus 12 tumor cells induced a cellular immunity to adenovirus 12 mouse tumor cells but not to a mouse polyoma tumor. Adenovirus 1 rat tumor cells induced no such immunity. Immunization of rats with syngenic adenovirus 12 tumor cells induced a cellular immunity to adenovirus 12 rat and mouse tumors and an adenovirus 7 hamster tumor, but not to an adenovirus 1 rat tumor or BHK‐C13 control hamster cells. The result of a tumor prevention experiment is consistent with the existence of a common TSTA induced by types 7 and 12 and a different TSTA induced by type 5 virus. It is concluded that the highly oncogenic group A and the weakly oncogenic group B adeno virus types all induce a common TSTA. Another TSTA is induced by the group C viruses, while no evidence has been obtained for the existence of any TSTA induced by a group D virus type.
Rous sarcoma recurrence and Rous sarcoma virus growth in chicken muscle
Authors: Dinowitz Marshall , Rabin Harvey
Published: February 2007

Following Rous sarcoma virus (RSV‐Bryan standard strain) infection and tumor regression in chickens, tumors recurred in 3 of 6 chickens after contralateral inoculation of 105 of RSV. In an attempt to understand the mechanism of tumor recurrence, chickens which had recovered from RSV infection were inoculated at the regression site with Rous associated virus (RAV). Tumors recurred in one‐third of those chickens that received three bi‐weekly RAV injections and in one chicken that received only a single RAV injection. The tumors re‐appeared from 6 to 19 weeks after regression of the original tumors and within 4 weeks of the last RAV challenge. RSV was recovered from cultures of a recurring tumor as well as from a wing that developed subcutaneous blistering following RAV inoculations. RSV was also obtained from 40% of “recovered” wing muscles explanted in tissue culture up to 3 months after regression. In addition, RSV was isolated from a tumor that recurred in one of 12 recovered chickens inoculated with Freund's adjuvant.

In an attempt to determine if ageing of muscle contributed to resistance to infection and suppression of tumor recurrence, wings of 5‐week‐old and 12‐week‐old chickens were infected with RSV and RAV, or RAV alone. RSV and RAV were recovered from most muscles explanted 48 h or more after RSV infection of 5‐week‐old chickens. However, when muscles from 12‐week‐old chickens were explanted 4 days after infection, very little RSV was recovered, although most of the RAV‐infected wings produced RAV in culture. This suggests that RAV growth in older muscles is probably not the limiting factor in RSV growth.

The relationship between various factors involved in resistance to tumor development and tumor recurrence in chickens recovering from RSV infections is discussed.
Nasopharyngeal carcinoma (NPC). I. Types of cultures derived from tumour biopsies and non‐tumorous tissues of chinese patients with special reference to lymphoblastoid transformation
Authors: de‐Thé G. , Ho H. C. , Kwan H. C. , Desgranges C. , Favre M. C.
Published: February 2007

Biopsy specimens of nasopharyngeal carcinoma (NPC) from Chinese patients were sent from Hong Kong to Lyons and cultured in vitro. Four different types of culture were obtained: 1) epithelial growth of short duration (4 to 12 weeks) and limited extent around the explants; 2) early lymphocytic production (ELP) which lasted for 1 to 3 weeks; 3) fibroblastic cultures (either as primary or secondary to the epithelial growth); 4) “lymphoblastoid transformation” which occurred in 28% of the cultures and resulted in the establishment of long‐term free‐floating cell‐lines. A few of these lines were intermittently dependent on the presence of fibroblasts during crises, while most of them were entirely independent.

Biopsy specimens from head and neck tumours other than NPC, from hypertrophied and inflamed tonsils removed from children, and from apparently tumour‐free nasopharyngeal mucosa gave rise to a similar spectrum of cultures, including the establishment of long‐term lymphoblastoid cultures.

The various lines thus obtained exhibited the presence of a herpes‐type virus (HTV). It is proposed that the establishment of permanent lymphoblastoid lines is caused by the presence, in the original material, of an HTV having “transforming” properties. The significance of these results and the nature of the serological association between NPC and HTV are discussed.
Transformation of human cells by polyoma and rous sarcoma viruses mediated by inactivated sendai virus
Authors: Shevliaghyn V. J. , Karazas N. V.
Published: February 2007

Transformation of embryonic human fibroblasts was obtained by treatment with inactivated Sendai virus and polyoma virus. Transformed cells differed morphologically from normal cells and formed a stable cell line (P‐2). A stable transformed cell line (23) was also formed after absorption of Rous sarcoma virus (Schmidt‐Ruppin strain) and inactivated Sendai virus on the embryonic human fibroblasts.

Cell line P‐2 and cell line 23 contained a human chromosome set, although some karyological abnormalities were apparent.

The cell lines P‐2 and 23 showed some characteristics of malignant cells growing in vitro (ability to multiply when suspended in semi‐solid medium and to form tumours in the cheek pouches and brains of golden hamsters). The potent transforming factor (s) was/were synthesized by these cells. The transforming factors had some properties identical to those of polyoma or Rous viruses and caused rapid transformation of embryonic mouse and human cells growing in vitro.

Foci of epithelioid cells appeared in human embryonic fibroblasts after the absorption of human adenovirus type 12 and inactivated Sendai virus.
Malignancy, electrophoretic mobilities and sialic acids at the electrokinetic surface of TA3 cells
Authors: Weiss L. , Hauschka T. S.
Published: February 2007

The influence of incubation with neuraminidase on the electrophoretic mobilities of TA3 mouse ascites carcinoma cells was investigated. TA3 cells characterized by extreme karyotypic stability and uniform lethality for all mouse strains (LD100 <3,000 cells) were procured from six different strains of mice at the same stage of tumour growth and were compared. Despite significant differences in “malignancy”, depending on the iso‐immune gap between tumour and host and assessed by survival times, there was no corresponding difference in electrophoretic mobility and/or the density of sialic acids at the electrokinetic surfaces of the cancer cells. Therefore, in this system, the net negative charge at the surface of the individual cancer cell bears no functional relation to degree of malignancy, as has been speculated for tumours in general.
Immunological studies on mouse mammary tumors. V. Chemical analysis of further purified tumorspecific antigen of mouse mammary tumor
Authors: Irie Reiko Furuse , Kataoka Tateshi , Mitsui Hiromi
Published: February 2007

The tumor‐specific antigen present in mouse mammary tumor MM102 was further purified by 75% ethanol (EtOH Ag fraction) and its biological activity and chemical composition were analysed. Recovery of the antigenic activity was 25%, and the antigenic activity was found to be purified 22‐fold on a dry‐weight basis. This fraction inhibited the cytotoxic activity of the tumor‐specific antiserum (RMS), and induced heightened resistance against MM102 in syngeneic C3H/He mice. Chemical analysis of the lyophilized EtOH Ag fraction showed that it was composed of 11.7% protein, 83.3% lipid, 0.35% sugar, and 3.9% RNA. Lipid analysis showed that the ratio between phospholipid and neutral lipid in lipid moiety was 44:56 and the content of sphingomyelin in phospholipid was 19.3%. On the basis of these lipid analyses the possibility that the antigenic material might be extracted from plasma membrane is discussed.
The growth capacity of normal and Rous‐virus‐transformed chicken fibroblasts in vitro
Authors: Pontén Jan
Published: February 2007

The proliferation dynamics of chicken embryo cells after transformation by Rous sarcoma virus, Schmidt‐Ruppin strain (RSV‐SR) has been investigated in vitro. The optimal schedule for serial cultivation for normal as well as transformed cells was to subcultivate the cells every third day using an inoculum of 50 X 104 cells per cm2 culture vessel area. Normal cells could be carried between 20–27 passages before they were lost in a degenerative phase similar to that described for normal human and other fibroblast‐like cells (Hayflick and Moorhead, 1961). The cumulative number of cells from a second passage inoculum of 2 × 106 cells varied between 109 and 1012. RSV‐SR transformed cells differed from normal cells in showing a decrease of the average population doubling time from 21 to 15 h and a two‐fold increase of their maximal terminal cell density. The life‐span of the RSV‐transformed populations was reduced to about 50% of the number of passages obtained by normal cells. The net result was a decrease of the cumulative cell number after transformation by RSV‐SR. No established RSV‐transformed or ‐untransformed lines could be developed.

When RSV‐SR‐transformed cells of one sex were cocultivated with normal cells of the opposite sex a rapid transformation of the latter was observed. The proportion of dividing cells belonging to the originally transformed population gradually diminished until the cultures were completely dominated by freshly transformed cells.

The results fit a previous hypothesis on the growth mechanism of avian Rous sarcoma (Pontén, 1964). RSV induces a change which enables the cell to proliferate at a faster than normal rate, to grow in an irregular manner in vitro, to reach higher than normal local densities in vitro and to invade surrounding normal tissues in vivo. None of these properties is permanent and the transformed or neoplastic cell populations will have a reduced total life span compared to their normal counterparts. Only if normal cells are constantly transformed and added to the proliferating pool of transformed or neoplastic cells will progressive growth prevail. The model is strictly applicable to stable systems (chicken, bovine, human); unstable species with a high spontaneous rate of transformation into established lines (mouse, rat, hamster) will react with the development of autonomously proliferating RSV cells capable of an infinite number of cell divisions.
Studies on the loss of growth inhibition in cells infected with Rous sarcoma virus
Authors: Weiss Robin
Published: February 2007

The loss of density‐dependent and anchorage‐dependent growth was studied in cells infected with RSV. Transformed cells, but not uninfected cells, will proliferate in soft gel suspension and amongst crowded normal cells. A large proportion of cells freshly infected with RSV acquired the capacity to proliferate in soft agar suspension even when placed in suspension immediately after infection.

Cell transformation and viral replication were inhibited by plating freshly infected cells on to crowded mouse embryo cells or 3T3 cells. The inhibition of cell transformation depended on close proximity to crowded mouse cells spread on a solid substratum. Cells became released from density‐dependent transformation within 12 h following infection. The change in proliferative behaviour of transformed cells was not influenced by the quantity or envelope properties of virus released from the cell surface. Pre‐infection with RAV1 did not affect density‐dependent cell transformation by RSV.

Freshly infected cells held in the inhibited state for 6 days were able to transform when replated to sparse conditions. It was concluded that cell transformation depended on cell proliferation but that infection with RSV could not initiate the cell division cycle in crowded monolayers.
Serum alpha‐fetoprotein and variant alkaline phosphatase in human hepatocellular carcinoma
Authors: Poertugal M. L. , Azevedo M. S. , Manso Carlos
Published: February 2007

Alpha‐fetoprotein and variant alkaline phosphatase were studied in a group of patients with hepatoma. The incidence of positive alpha‐fetoprotein was 67.6% in confirmed cases. Variant alkaline phosphatase was present only in patients with positive fetoprotein test, and it appeared in only 28.6% of the cases.
Studies on the infectivity and cytopathology of epstein‐barr virus in human lymphoblastoid cells
Authors: Durr F. E. , Monroe J. H. , Schmitter R. , Traul K. A. , Hirshaut Y.
Published: February 2007

The infectivity of EB virus recovered from cultures of P‐3J and the HR1K clone of this cell line has been demonstrated in established lymphoblastoid cell lines derived from healthy human donors and from patients with neoplastic disease. Filtered virus concentrates induced cell alterations similar to those produced by other members of the herpes group of viruses. Cell responses observed were: 1) an acute cytopathic effect evident within 16–72 h and characterized by cell swelling, polykaryocyte formation and progressive degeneration, and 2) a less severe CPE with minimal cell swelling and degeneration followed by either the establishment of a carrier culture or more often a culture in which the virus eventually disappeared. Characteristic non‐enveloped herpes‐virus‐type particles were seen in the cell nucleus as early as 16 hours post exposure to virus and, subsequently, enveloped virions were found in the cytoplasm. A non‐productive or abortive infection of the lymphoblastoid cells was indicated by the higher incidence of cells showing viral antigen by immunofluorescence, than the presence of virus particles. The infectivity of EBV was neutralized by human sera containing antibodies reactive with the viral envelope.
Binding of dimethylaminoazobenzene metabolites to DNA and proteins. I. in vitro studies on a microsomal dependent system
Authors: Meunier Michèle , Chauveau Jean
Published: February 2007

Incubating dimethylaminoazobenzene [aniline ring (U)14 C] (DAB), purified thymus DNA and rat liver microsomes led to a covalent binding of radioactivity to DNA and proteins, which implied the presence of bound DAB metabolites.

This binding required an enzymatic activation. We studied some characteristics of the enzymatic process, i.e. NADPH requirement, effect of pH, effect of various concentrations of microsomes and DNA, induction by 3‐methylcholanthrene.

This in vitro system is discussed in view of its validity for studying interactions between the carcinogenic azodyes and the cellular constituents.
Demonstration by colony inhibition methods of cellular and humoral immune reactions to tumour‐specific antigens associated with aminoazo‐dye‐induced rat hepatomas
Authors: Baldwin R. W. , Embleton M. J.
Published: February 2007

Cellular and humoral immune reactions against tumour‐specific antigens on aminoazo‐dye‐induced rat hepatomas were demonstrated in vitro by the colony inhibition technique. Lymph‐node cells from syngeneic rats immunized against individual hepatomas inhibited colony formation by cells of the immunizing tumour compared with the effects of normal lymph‐node cells. Also immune lymph‐node cells were not inhibitory to hepatomas other than the one used for immunization, reflecting the individual specificity of the antigens on these hepatomas. Serum‐mediated inhibition of colony formation by rat hepatoma cells, in the presence of complement, was also demonstrated and these reactions were similarly directed against cells of the immunizing tumour. This specificity of colony inhibition by immune lymph‐node cells and serum further amplifies the evidence for the individually distinct antigenicity of these hepatomas already revealed by transplantation and immunofluorescence tests.
Differences in the manifestation of virus‐specific surface antigen between cells transformed by sv40 and uv‐irradiated sv40
Authors: Klietmann W. , Seemayer N.
Published: February 2007

Marked differences in the manifestation of SV40‐specific surface (S‐) antigen were found between hamster cell lines transformed in vitro and in vivo by SV40 and UV‐irradiated or photodynamically inactivated SV40. In the mixed hemagglutination reaction (MHA) cell lines induced by non‐irradiated SV40 yielded positive results when tested against specific antisera up to dilutions of 1:1280. In comparison, cell lines induced by inactivated SV40 only showed positive reactions in the MHA‐test in dilutions up to 1:80 or 1:160 respectively. The demonstration of small quantities of SV40‐specific S‐antigen in cell lines transformed by inactivated SV40 could only be achieved by use of hyperimmune sera produced by a special immunization procedure. However, if these cells were tested in the MHA reaction against anti‐S‐sera, produced according to conventional methods described in the literature, they yielded negative results. All cell lines with diminished quantities of demonstrable S‐antigen caused malignant tumors when inoculated into adult hamsters. The capacity of UV‐irradiated SV40 to induce a specific transplantation resistance in adult Syrian hamsters was investigated. The irradiated virus induced a markedly reduced transplantation resistance.
The development of chick‐embryo‐lethal‐orphan (CELO) virus T and V antigens in lytically infected chick kidney cells
Authors: Anderson Jeffrey , McCormick Kenneth J. , Stenback Wayne A. , Trentin John J.
Published: February 2007

The sequential development of the CELO‐specific T and virion antigens was studied in lytically infected chick kidney cells using the indirect immunofluorescence technique. The T antigen was detected 6 hours after infection, and rapidly increased until a peak was reached at 20–24 h. The V antigen could not be detected until 20 h after infection. The V antigen, but not the T antigen, was inhibited by cytosine arabinoside. Both antigens were inhibited by cycloheximide. After storage in liquid nitrogen for 3 weeks, the T antigen in fixed cells could not be detected by indirect immunofluorescence tests.
Studies on the mechanisms of invasion in cancer. II. In vivo effects of a factor chemotactic for cancer cells
Authors: Ozaki Teruhisa , Yoshida Kenshi , Ushijima Kenichiro , Hayashi Hideo
Published: February 2007

A substance chemotactic for tumor cells was isolated from some tumor tissues of animal and human origin and highly purified. It induced an extravascular emigration of circulating tumor cells on experimental injection, but no emigration of polymorphonuclear leukocytes. The emigrated tumor cells proliferated in the extravascular tissue and invaded the surrounding tissues, and a metastatic secondary tumor was formed. This material had no activity to increase vascular permeability. Permeability factors, isolated from tumor tissues, histamine and bradykinin were ineffective for tumor‐cell emigration. A factor chemotactic for polymorphonuclear leukocytes, isolated from inflamed sites, induced an emigration of the cells on experimental injection, but no emigration of tumor cells. These observations suggested that the cancer cell chemotactic factor might be associated with malignant invasion.
Ultraviolet inactivation of murine leukemia and sarcoma viruses
Authors: Yoshikura H.
Published: February 2007

The ultraviolet (UV) sensitivity of Friend leukemia virus and a murine sarcoma virus (MSV) was determined. The inactivation dose D10 was 2,000 to 3,000 ergs/mm2 for both. This value is close to the one obtained with Rous sarcoma virus, 3,000 ergs/mm2 (Goldé et al., 1961). MSV produced by the cells incubated in 5‐fluorouracil (5 × 10−3 M) was significantly more UV sensitive than control MSV, suggesting the sensitization of the viral nucleic acid by the base analogue.

The virus surviving UV irradiation showed a prolonged latent period, but it was due to the interference of the inactivated virions with the normal growth of surviving virions.

When UV‐irradiated MSV was titrated on the cells previously irradiated with UV, the slope of the inactivation curve was steeper than when the virus was titrated on the normal cells. This may suggest the complementation of the UV‐damaged viral genome by the corresponding homologous host genome.
Mammary tumors, plaques, and hyperplastic alveolar nodules in various combinations of mouse inbred strains and the different lines of the mammary tumor virus
Authors: Heston W. E. , Vlahakis G.
Published: February 2007

The following strains have been bred and developed for mammary tumor studies in this laboratory; C3H, C3HfB, C3HfDD, C3H‐Avy, C3H‐AvyfB, DD, DDfB, DDfC3H, BALB/c, BALB/cfDD, BALB/cfC3H, A (High), A (Low), AfB, and C57BL. Data are presented on mammary tumor incidence and age, occurrence of plaques, and occurrence of hyperplastic nodules. C3H‐Avy is our highest mammary tumor strain, whereas C57BL is the most resistant. A complete range of mammary tumor incidences and average ages depending upon the strain of mouse and line of virus is found in the other strains. The occurrence of mammary tumors in strains fostered on C57BL ranges from an incidence of 90% at an average age of 15 months in C3H‐AvyfB, although there is no evidence of any milk‐transmitted virus, to 1.3% at 16.5 months in AfB. We continue to find an incidence of 20% at 17 months in BALB/c although we have no conclusive evidence of the virus. C3H virus has a greater potency than DD virus. Plaques are the result of DD or BALB/c genotype and DD virus but not of C3H or A genotype or of C3H or A virus. Hyperplastic nodules appear in all strains that develop mammary tumors, the age at which they appear depending upon the mouse strain and line of virus. These data form the foundation for other studies with these strains. The strains are now available to other investigators.
Stimulation of liver dna synthesis by a factor from ascites tumor 6c3hed
Authors: Yarbro J. W.
Published: February 2007

C3H mice inoculated with 6C3HED ascites tumor show a gradual increase in the incorporation of 32P into liver DNA. Cell‐free supernatant fluid from this tumor has the capacity to stimulate increased incorporation of 32P and 3H‐labelled thymidine into liver DNA of mice not bearing the tumor. This liver‐stimulating activity (LSA) was destroyed by heating to 60° C for 30 min and by pronase but not by RNase or DNase. The time of maximum stimulation of liver DNA synthesis was on the 4th day after injection of LSA. A 70‐fold purification of LSA was accomplished using sephadex chromatography. It is suggested that LSA is the factor responsible for the increased liver DNA synthesis seen in tumor‐bearing animals, but the mechanism of this action has yet to be explained.
Some effects of neuraminidase on the in vitro interactions between spleen and mastocytoma (P815) cells
Authors: Weiss L. , Cudney T. L.
Published: February 2007

A recently advanced generalization is that a sialomucin coat surrounding tumour cells protects them from immunological surveillance. We have therefore studied the effects of neuraminidase (sialidase) on the immunolysis of P815 mastocytoma cells by sensitized spleen cells, in vitro, to test this hypothesis. In a very sensitive system in which immunolysis was quantitated by measurements of the release of 51Cr from labelled P815 cells, neuraminidase treatment of the target cells did not demonstrably make them more susceptible to attack by spleen cells. Killing proceeded in spite of a substantial contribution of sialic acid moieties to the net negative surface charge of the untreated P815 cells, and was not enhanced by enzymatic removal of substantial amounts of their bound surface sialic acids, as determined by cell electrophoresis. Thus, the generalization cannot be substantiated by our experiments. An interesting positive finding was that neuraminidase treatment of the killer, spleen cell population, enhances the 51Cr‐release from their targets.
Studies of carcino‐fetal proteins: Physical and chemical properties of human α‐fetoprotein
Authors: Ruoslahti Erkki , Seppälä Markku
Published: February 2007

To obtain information on the relationship between a carcino‐fetal protein, α‐fetoprotein, fetal proteins from other species and other human serum proteins including the fetoprotein in patients with hepatocellular cancer, α‐fetoprotein was purified and characterized from the serum of human fetuses. The protein is composed of a single polypeptide chain. A molecular weight of 70,000 was obtained by gel electrophoresis in the presence of SDS and by gel filtration. The isoelectric point of α‐fetoprotein was found to be 4.75. It contains 4.3% carbohydrate with 2 moles of sialic acid per mole of protein. The amino acid composition of α‐fetoprotein was determined.
Blocking of cell‐mediated tumor immunity by sera from patients with growing neoplasms
Authors: Hellström Ingegerd , Sjögren Hans Olov , Warner Glenn , Hellström Karl Erik
Published: February 2007

Blood lymphocytes from tumor patients can specifically destroy cultivated neoplastic cells of the same histological origin as the tumors of the lymphocyte donors, irrespective of whether or not the donors have symptoms of growing tumor.

The purpose of the present study was to investigate whether sera from tumor patients could block the cytotoxic effect of lymphocytes immune to the specific antigens of the respective neoplasms. A wide variety of tumors were included in the tests, namely malignant melanomas, carcinomas of the colon, breast, ovary, endometrium, kidney, cervix uteri, lung, larynx, bladder, Fallopian tube, lip, seminomas and sarcomas.

Sera from 67 out of 81 patients with growing neoplasms were found to block the cytotoxic effect of specifically immune lymphocytes. A blocking effect was seen both when the tumor cells, lymphocytes and sera were derived from the same patients and when the lymphocytes and sera were taken from different donors who had the same types of tumor as the target cells. No blocking was seen when the same sera were tested on tumors of histological types other than those of the respective serum donors.

A blocking serum activity was seen in only three of 19 patients who were symptomfree after tumor therapy. The findings thus suggest that there is a correlation between tumor growth in vivo and the presence of a blocking serum activity in vitro.
Epithelial outgrowths from lung tissue following intrapleural injection of asbestos dust in experimental animals
Authors: Davis J. M. G.
Published: February 2007

After the intrapleural injection of asbestos dust in experimental animals, granulomas were produced and large areas of the pleural surface became thickened with fibrous tissue. In guinea‐pigs injected with chrysotile dust, alveolar epithelial cells often migrated through the lung surface and were found lining spaces in the areas of pleural fibrosis. Initially these cells exhibited the exact structure of the surfactin‐secreting type of alveolar cell, but later many of the cells lost the surfactin granules from their cytoplasm and became ciliated. In some animals cystic formation occurred in the lung tissue and groups of cysts grew out from the lung to invade the areas of pleural fibrosis. These cysts were also lined with surfactin‐secreting alveolar cells. The possible association of these epithelial outgrowths and the well‐known difficulties of diagnosing pleural mesotheliomas are discussed.
Evidence of formation of N‐methyl‐N‐nitrosourea in rats given n‐methylurea and sodium nitrite
Authors: Montesano Ruggero , Magee P. N.
Published: February 2007

N[14C]‐methylurea and sodium nitrite were administered simultaneously to rats by stomach tube in order to demonstrate methylation of the nucleic acids due to the formation in the stomach of the corresponding nitrosamide, N[14C]‐methyl‐N‐nitrosourea. The ion‐exchange chromatograms of the hydrolysates of stomach, liver and small intestine nucleic acids show a radioactive peak corresponding to the altered base 7‐methylguanine in the rat receiving N[14C]‐methylurea and sodium nitrite. No evidence of 7‐methyl‐guanine was obtained when N[14C]‐methylurea was administered alone. These findings are interpreted as indicating that the highly potent carcinogen N‐methyl‐N‐nitrosourea is formed in the stomach as a result of the nitrosation of the corresponding secondary amide and absorbed into the circulation of the rat. The possible consequences of the in vivo formation of carcinogenic N‐nitroso compounds in the aetiology of cancer are discussed.
Some preliminary observations on the influence of genetic admixture on cancer incidence in american negroes
Authors: Petrakis Nicholas L.
Published: February 2007

Estimates of the extent of genetic admixture in biracial hybrid populations may be of potential use in the identification of the genetic component of disease.
Assessment of risk patterns in cancer of the cervix: A comparison between greater Bombay and Western countries
Authors: Jussawalla D. J. , Deshpande V. A. , Standfast S. J.
Published: February 2007

In order to identify the high‐risk groups in the community, a retrospective study of 503 women with histologically proved invasive carcinoma of the uterine cervix was undertaken and the results were compared with a similar appraisal of an equal number of controls closely matched for age, religion and income, in order to examine certain risk factors suspected of being of aetiological importance in patients with cervical cancer. We have sought to estimate the effects of parity, and of age at first marriage, first delivery and last delivery. The highest risk was observed in women who had undergone several pregnancies early in life. It is interesting to note that multiparity was one of the important risk factors in Bombay women, in contrast with the situation reported in Western countries.
Further manifestations of abortive transformation of bhk 21 cells by polyoma virus
Authors: Taylor‐Papadimitriou Joyce , Stoker M. G. P. , Riddle P.
Published: February 2007

Abortive transformation of layer cultures of BHK 21 cells by polyoma virus has been studied using serum‐depleted medium. High doses of partially purified infectious virus, in the absence of serum, stimulate the majority of the cells to synthesize DNA while empty capsids do not. The onset of DNA synthesis occurs approximately 28 h after infection, and in medium containing 0.8% γ‐depleted serum, can be followed by one round of mitoses. A temporary loss of oriented arrangement of cells is also observed commencing 25 to 30 h after infection. Abortively transformed cells resemble stably transformed lines of BHK 21 cells in their requirements for the factors in serum operative in the control of growth.
Cellular immunity to nephroblastoma
Authors: Diehl V. , Jereb Berta , Stjernswärd J. , O'toole Carol , Åhström L.
Published: February 2007

Lymphocytes from 24 patients with nephroblastoma and 24 controls have been tested for tumor‐related cytotoxicity in vitro. The micro‐plate technique has been applied in 26 tests and the cytotoxic plaque test in eight.

In 10 out of 24 nephroblastoma patients with two autochthonous and eight allogeneic combinations, tumor‐related cell‐mediated cytotoxicity has been found. Lymphocytes from control subjects were less cytotoxic against nephroblastoma cells and affected tumor and control cells to the same degree. Lymphocytes from patients treated for primary tumors showed tumor‐destructive reactions more often than those from patients treated for disseminated disease.
Effect of antithymocytic serum on viral leukemia, erythroblastosis, and sarcoma in mice
Authors: Varet B. , Levy J. P. , Leclerc J. C. , Kourilsky F. M.
Published: February 2007

The effect of heterologous antilymphocytic sera (ALS) on the growth of a number of virus‐induced erythroblastoses, leukemias and sarcomas in mice has been investigated. Erythroblastosis is markedly stimulated by ALS, given either before or several days after virus inoculation. The stimulating effect of ALS administration on the outgrowth of murine sarcoma is strong if ALS is given before MSV inoculation, and weak when given no more than 24 h after the virus. Conversely, a stimulating effect of ALS on the development of leukemias was barely detectable, suggesting that immune reactions are less effective in the studied leukemia than in sarcoma and erythroblastic disease. An erythroblastic disease similar to the Friend‐Rauscher virus induced splenomegaly was observed after inoculation of Moloney leukemia virus or sarcoma virus and ALS.
Electron microscopic detection of transforming viruses induced by cell association. I. The SV40 model
Authors: Menezes José
Published: February 2007

This paper describes a study on the application of electron microscopy for rapid detection of SV40 particles rescued from transformed cells by co‐cultivation or fusion of these cells with either permissive or naturally insusceptible cells and discusses the utility of the electron microscope as a rapid means for the detection of virus recovered from human or animal tumors, as well as from other diseases where viral etiology seems the most probable.
Lysosomes of rat liver and dab carcinogenesis
Authors: Takano Tatsuya , Kato Nobuo , Kunimoto‐Miyata Setsuko , Goto Sataro , Ohkuma Shoji , Mizuno Den'ichi , Kitagawa Tomoyuki , Yokoyama Takeshi
Published: February 2007

The relationship between DAB carcinogenesis and changes of lysosomes in rat liver was investigated. After 40 days of treatment with DAB, nodules and an abnormal cell population, containing small, large and degenerative cells, appeared. Corresponding to these changes, the S/P ratio of lysosomal enzymes such as acid RNase and β‐glucuronidase increased to two or three times the normal value. These alterations were considered along with some histochemical observations on β‐glucuronidase. A possible participation of these lysosomal enzymes in carcinogenesis is discussed.
Cancer survey in south iran with special reference to gastrointestinal neoplasms
Authors: Barekat Ali Asghar , Saidi Farrokh , Dutz Werner
Published: February 2007

To supplement existing data on cancer epidemiology for Iran, a survey covering an 8‐year period (1962–1969) was carried out among the indigenous population of Fars, a southern province of the country. A total of 1,987 male and 1,288 female cancer cases were studied, and the relative frequency of the most common neoplasms compared with that in (1) the capital city, Tehran, (2) a neighboring country, Afghanistan, and (3) a distant western country, Sweden. The most common tumors in order of decreasing frequency were, among males, cancer of the skin, lymphoid system, lung, stomach, bladder, hematopoietic system and esophagus; and among females, cancers of the skin, cervix, breast, lymphoid system, esophagus, hematopoietic system and ovary. The proximal portion of the gastrointestinal tract seemed in general to be more commonly the site of malignant change than the distal part. While the frequency of esophageal cancer was relatively high, there was a paucity of cancer of the colon. For reasons as yet unexplained malignant lymphomas appeared to be among the most common malignant tumors of the bowel.
The effect of polyinosinic: Polycytidylic acid on fluorescent and neutralizing antibodies to herpesvirus saimiri in goats
Authors: Fraser C. E. O. , Meléndez L. V. , Barahona H. H. , Daniel M. D.
Published: February 2007

Goats are the best species so far tested for the preparation of fluorescent and neutralizing antibodies to Herpesvirus saimiri. Fluorescent antibodies to Herpesvirus saimiri seem to be different to neutralizing antibodies and polyinosinic: polycytidylic acid (poly I: C) may be of value in separating these two activities.

Primary response fluorescent antibodies stained infected monolayers in a characteristic pattern, which is different from that of secondary response antibodies. The immunological and epidemiological implications of this are discussed.
Protection against spontaneous mouse mammary adenocarcinoma by inoculation of heat‐treated syngeneic mammary tumor cells
Authors: Check Jerome H. , Childs T. Craig , Brady Luther W. , Derasse Alain R. , Fuscaldo Kathryn E.
Published: February 2007

The purpose of the study was to determine the effect of the inoculation of syngeneic mouse mammary tumor cells on the incidence of spontaneous tumors and mortality in a group of RIII female mice which normally have a high incidence of primary breast tumors. Animals were inoculated with either untreated, heat‐treated or irradiated tumor cells or a combination of cells. One group received no injections and served as a control.

The incidence of tumor development and mortality was recorded for each animal used in the study. Significant delays in tumor onset and subsequent death of the animals were noted in those groups that had been injected with heat‐treated cells as compared to those animals that had been inoculated with non‐heated cells (either irradiated or untreated) or the untreated controls. No detectable differences were found between the groups receiving non‐heated cells and the untreated control group.

It was found that the protection derived from inoculation of heat‐treated tumor cells was not due to decreased tumor growth rate, but was more probably related to the destruction of a portion of the tumor cell population.
Deoxyribonucleic acid polymerase associated with feline leukemia and sarcoma viruses: Properties of the enzyme and its product
Authors: Roy‐Burman P.
Published: February 2007

Native calf thymus and salmon sperm DNA are better templates than denatured calf thymus and salmon sperm DNA for the DNA‐dependent DNA polymerase activity of feline sarcoma virus. This enzyme activity of feline sarcoma virus and feline leukemia virus faithfully replicates dAT copolymer to synthesize a sequence of alternate deoxyadenylate‐deoxythymidylate. With a homopolymeric duplex, polydA.dT, the DNA‐directed enzyme from feline sarcoma virus or feline leukemia virus indicates a requirement for simultaneous copying of both template strands.
Mammotropic and somatotropic hormones in sera of normal rats and in rats bearing primary and grafted pituitary tumors
Authors: Ito A. , Martin J. M. , Grindeland R. E. , Takizawa S. , Furth J.
Published: February 2007

Parallel determinations were made of the concentration of MtH and StH in the sera of rats with spontaneous, estrogen‐induced and grafted pituitary tumors and, for a base, in sera of normal rats of both sexes, in various physiologic states, following oophorectomy and treatment with gonadal hormones.

The characteristic sharp rise of MtH during proestrus was confirmed. This was not accompanied by a rise in StH.

Following oophorectomy the levels of both hormones dropped. After estrogen treatment of normal rats, both hormones rose gradually, reaching very high levels with development of pituitary tumors. Similar increases were found with spontaneous mammotropic tumors (MtH) in rats of both sexes.

Seven MtT's, originating in six different strains, were studied in the course of successive transplantations. All exhibited mammary gland stimulation, with very high MtH and StH levels, depending on the tumor size and tumor strain. In general, hormone secretion decreased in the course of successive transplantations.

One variant of the originally typical MtT.W5, MtT.W5/H, markedly lost the ability to produce MtH while maintaining the ability to produce StH, as indicated by both radioimmunoassays and biological changes in the tumor hosts. The oldest transplantable tumor of this series (MtT.F4), secreted large quantities of AtH and StH without biological evidence of somatotropic effects. The StH effect became “unmasked” by adrenalectomy. Biological evidence of AtH secretion by the other MtH strains was inconstant and variable. It was often present in the first transplant generation but vanished in the course of successive transplantations with the exception of the F4 strain.

The MtH values in normal as well as MtT‐bearing hosts were higher in female than in male rats. There was relatively more StH in males than in females.
Tissue‐dependent differences in dna methylation products of mice treated with methyl‐labelled methylnitrosourea
Authors: Frei Jaroslav V.
Published: February 2007

Adult inbred Swiss mice were given a single carcinogenic dose of methyl‐labelled methylnitrosourea in the range of doses which induces thymic lymphomas, lung adenomas and other random malignant tumours. DNA was extracted from pooled bone marrow, spleens, thymuses, kidneys, livers, or lungs within 1 h of injection and was hydrolysed and chromatographed to demonstrate the proportions of three products: 7‐methylguanine, 3‐methyladenine, and 6‐methoxyguanine. Disproportionately high relative amounts of 3‐methyladenine were found in the tissues thought to have a role in the genesis of thymic lymphomas. 6‐methoxyguanine, which Loveless (1969) postulates to be the product crucial for carcinogenesis, was detected in the DNA of all tissues examined. The possible usefulness of this approach to the study of carcinogenesis was thus demonstrated.
Étude de la Leucémogénèse akr a l'aide d'un marqueur cytogénétique
Authors: Legrand E. , Duplan J. F.
Published: February 2007

AKR‐TIALD mice bearing 38 chromosomes with 2 metacentrics are irradiated and restored with AKR (40 acrocentrics) bone marrow. These isogenic radiation chimaeras provide the opportunity to perform a cytogenetic study in order to determine the origin of the cells, the chronology of bone marrow thymus, and lymph node repopulation as well as of the leukaemic process. In AKR/TIALD chimaeras the repopulation of the lymphatic system follows the same steps as previously described in CBA/T6‐T6.

The lymphatic leukaemias induced by 4 irradiations of 175 R may be divided into three groups according to their latencies: (a) Early or radiation‐induced leukaemias which may originate from either host cells or donor cells or both (mixed leukaemias), (b) the leukaemias which appear between 180 and 220 days and belong mainly to host cells, (c) late leukaemias, posterior to 220 days, the cells of which are of donor origin.

Most leukaemias of host origin precede the leukaemias of donor origin because the cells of the latter must differentiate from the injected stem cells which first repopulate bone marrow into more mature elements which secondarily migrate into the thymic cortex where the lymphosarcomatous foci originate.

The results of an experiment where T1ALD mice were restored with an equal number of AKR and T1ALD bone marrow cells, point to the possible multifocal origin of the leukaemia. T1ALD cells have the same sensitivity to X radiation and to Gross virus than the cells from conventional AKR mice.
The effects of protease I of Aspergillus oryzae (brinase) on membrane permeability and growth of landschütz ascites tumour cells
Authors: Smyth Honor , Flahavan Eleanor , Thornes R. D.
Published: February 2007

Landschütz ascites tumour cells treated in vitro with Protease I showed no changes in intracellular K and Na levels when the cells were analysed directly at the end of the 60‐min incubation period. If, however, the cells were washed twice in the saline medium before analysis significant losses of K, apparently in exchange for Na, were found to take place. Controls incubated in the absence of Protease I and similarly treated showed no such K loss. Viability tests, using lissamine green, indicated that the observed changes were not due to dead cells. These findings are interpreted as being due to an alteration in the plasma membrane associated with increased sensitivity to mechanical trauma, which in turn leads to secondary loss of K. Increases in UV absorbance in the 260 nm region were noted in the supernatant medium of treated cells.

Normal mice weighing 30 g tolerated intraperitoneal injections of 0.3 mg Protease I and under, in repeated daily doses, but a single injection of 0.4 (i.e. 13 mg/kg) was lethal within 2 hours. The presence of tumour cells (7.5 mg dry wt) intraperitoneally was found to protect mice against repeated daily injections of this normally lethal dose, indicating that the enzyme is quickly adsorbed onto the tumour cells. No effect on tumour growth in vivo was found when single injections of Protease I were administered intraperitoneally at the same time as the tumour, but when additional doses of the enzyme were given on the two subsequent days, the 7‐day yield of tumour cells was significantly increased.
Histochemistry of giant cells in tumours induced in golden hamsters by murine sarcoma virus‐harvey
Authors: Hallowes R. C. , Chesterman F. C.
Published: February 2007

Tumours induced by murine sarcoma virus‐Harvey (MSV‐H) in golden hamsters are characterized by the presence of multinucleate giant cells. A histochemical study was undertaken to determine the relationship of the giant cells to each other and to the surrounding tumour. It was shown that the giant cells were not a homogeneous cell population. Those found in subcutaneous tumours showed no substrate‐specific phosphatases and had marked histochemical similarity to cells of the adjacent tumour. In paw, muscle and bone‐eroding tumours, most of the giant cells showed strong substrate‐specific phosphatase activity and no histochemical resemblance to cells of the adjacent tumour. Giant cells probably related to skeletal muscle were seen only where muscle was infiltrated by tumour. It was concluded that the giant cells were possibly related to the tumour cells only in the case of the subcutaneous tumours and that in the other tumours they were probably related to macrophages.
Spontaneous and adenovirus type 12‐induced chromosome aberrations in fanconi's anaemia fibroblasts
Authors: McDougall J. K.
Published: February 2007

The spontaneous aberrations which occur in cells from patients with Fanconi's anaemia have been shown to be distributed in a random manner. Adenovirus type 12‐induced chromosome aberrations are non‐random in cells from patients with Fanconi's anaemia and there is a high degree of specificity for a site on the No. 17 chromosome, as is found in cytogenetically normal human cells.

Although foci of infected cells were found in long‐term Fanconi cultures there was no evidence of viral transformation.