bluuebunny/crossref_metadata_2025 huggingface dataset:
Lactation and reproductive histories of breast cancer patients in greater athens, 1965–67
Authors: Valaoras Vasilios G. , Macmahon Brian , Trichopoulos Dimitrios , Polychronopoulou Antonia
Published: February 2007

As part of an international collaborative study, an attempt was made to identify all cases of breast cancer among residents of the Cities of Athens and Piraeus newly diagnosed in a period of 2 1/2 years. A total of 956 cases was identified, giving an annual average incidence rate of 34.9 per 100,000 female population. Rates by age and marital status are reported.

Of these cases 799 (84%) were interviewed, along with 2,470 controls. The controls were residents of Athens and Piraeus under treatment in the same hospitals as the breast cancer cases but for conditions other than breast cancer. In relation to the controls, the breast cancer cases were of low fertility. After adjustment for this difference there was no difference between cases and controls in any of a variety of measures of lactation experience.

The cases differed significantly from the controls in having higher socio‐economic status, earlier menarche, later first pregnancy, later menopause and greater height and weight. The ranges of these variables were associated with variations in breast cancer risk of the order of two or three fold.
Sequential effects of chemically different carcinogens, dimethylnitrosamine and 4‐dimethylaminoazobenezene, on hepatocarcinogenesis in rats
Authors: Takayama Shozo , Imaizumi Tadayoshi
Published: February 2007

Induction of liver tumors was studied in rats given carcinogens as follows: (1) N‐nitrosodimethylamine (DMN) alone; (2) 4‐dimethylaminoazobenzene (DAB) alone; (3) DMN followed by DAB; and (4) DAB followed by DMN. The main findings were:

(1) DAB feeding for 0.62 to 2.5 months, followed by DMN feeding for 5 months, induced liver carcinomas more frequently than did DMN alone given for 5 to 10 months, or DAB alone given for 2.5 months.

(2) Likewise, DMN feeding for 0.62 or 1.25 months, followed by DAB feeding for 5 months, induced liver carcinomas more frequently than did DMN alone given for 5 to 10 months or DAB alone given for 2.5 months. Interestingly, when DMN was given for a longer time (2.5 months), followed by DAB for 5 months, 50% of the induced liver tumors were non‐epithelial.

(3) Liver tumors were induced by sequential administration of the two carcinogens in doses that did not induce tumors when each carcinogen was given alone over a comparable time period.

(4) The latent period for liver tumor development was shorter in groups that received the two carcinogens sequentially than in those that received DAB or DMN alone for comparable time periods.
Disappearance of infectious virus from friend virus‐induced C57BL/6 tumors
Authors: Odaka Takeshi , Ikawa Yoji , Takizawa Kiyoshi
Published: February 2007

Mice of C57BL/6 strain which had been infected with Friend leukemia virus within 15 days after birth developed hepatosplenomegaly after a latent period of about 2 months. Without exception, the enlarged spleens of these diseased mice contained infectious virus. Isografts from 13 such spleens gave rise to 5 transplantable lymphomas. These 5 tumors were all derived from the mice with enlarged thymus and/or mesenteric lymph node, while no tumors were obtained from spleen grafts from the mice with non‐enlarged thymus and node. The tumors thus established were passed successively in solid form in C57BL/6 mice. They lost demonstrable virus within a few, at most 9, passages in syngeneic mice. With these characteristics, these tumors are unique among Friend tumors of murine origin, since all thus far reported contained readily demonstrable virus. The presence of virus‐specific transplantation antigens was confirmed in some of these tumors. The induction of lymphoblastic lymphomas by Friend virus in C57BL/6 mice was discussed.
EBV‐Associated serological patterns in a burkitt lymphoma patient during regression and recurrence
Authors: Klein G. , Clifford P. , Henle G. , Henle W. , Geering G. , Old L. J.
Published: February 2007

Three serological reactions have been followed in a Burkitt lymphoma patient during the clinical course of the disease, including long‐term regression, followed by recurrence and progressive growth, in spite of chemotherapy. Antibodies directed against surface antigens characteristic for EBV‐carrying lymphoblastoid cell lines of Burkitt lymphoma origin were assessed by blocking of direct membrane immunofluorescence. The level of surface reactive antibodies was high while the patient was in long‐term regression. It decreased to an insignificant level approximately half a year before tumor recurrence was clinically diagnosed. Immediately after the recurrence, it remained at a low level but increased subsequently and remained at a high level until the death of the patient. The anti‐EBV antibody level itself showed only minor fluctuations. Precipitating antibodies, directed against soluble antigen extracted from the EBV‐carrying Jijoye cell line, were absent during long‐term regression. They appeared soon after recurrence and remained at a high level until the patient died. Repeated biopsy specimens were taken after the recurrence. In the course of progressive growth, a coating of the IgG type was seen to accumulate on the surface of the tumor cells. Possible implications of these findings are discussed.
Aflatoxin carcinogenesis: Inhibition of liver cancer induction in hypophysectomized rats
Authors: Goodall C. M. , Butler W. H.
Published: February 2007

Intact and hypophysectomized male rats were fed aflatoxin at a dose (4 μg/g in diet) sufficient to produce liver cancers in all of the 14 intact rats surviving 49 weeks. Fourteen hypophysectomized rats also survived this latent period, but no liver tumors were induced although the animals received aflatoxin at a higher rate than the intact control animals. However, tumors of extrahepatic tissues—particularly of the retro‐orbital lacrimal glands—were induced in the hypophysectomized rats. The selective blockade of hepatocarcinogenesis by hypophysectomy previously known with aminoazo dyes and fluorenamines is therefore extended to a new class of chemicals, the aflatoxins. It is suggested that aflatoxins may require metabolic activation before becoming effective carcinogens for rat liver.
A spleen weight assay for murine sarcoma virus harvey (MSV‐H)
Authors: Hirsch Martin S. , Harvey Jennifer J.
Published: February 2007

A spleen weight assay has been developed for titrating murine sarcoma virus‐Harvey (MSV‐H) 3 weeks after intraperitoneal infection of newborn BALB/c and random‐bred albino mice. Induction of splenomegaly corresponded in time with development of sarcomas and anaemia. The assay was also used to evaluate sera for neutralizing antibodies to MSV‐H. Weanling mice were much less susceptible to erythroblastic splenomegaly and tumour induction than newborns. Random‐bred mice were found more satisfactory for the assays than BALB/c mice. Newborn Sprague‐Dawley rats also responded to MSV‐H inoculation with a dose‐dependent erythroblastic splenomegaly.
Large‐ and small‐plaque variants of oncogenic simian adenovirus SA7(C8)
Authors: Altstein A. D. , Dodonova N. N. , Tsetlin E. M. , Babakova S. V. , Levenbook I. S.
Published: February 2007

Preparations of simian adenovirus SA7, strain C8, highly oncogenic for hamsters, contain a mixture of large‐ and small‐plaque variants. The variants do not differ in their adsorption rates, virus yield per cell, sensitivity to sulfated agar polysaccharides or antigenic properties, as determined by neutralization tests. However, the small‐plaque variant releases infectious virus from cells at a slower rate than the large‐plaque variant. It is also more oncogenic for hamsters than the large‐plaque variant, but the tumors induced by the two variants do not differ morphologically. The variants seem to induce a transplantation antigen of similar or related antigenicity. Fewer cells are required for transplantation of tumors induced by the original virus and the small‐plaque variant than for transplantation of tumors induced by the large‐plaque variant.
Studies on murine sarcoma virus: antigenic characterization of murine sarcoma virus induced tumor cells
Authors: Chuat Jean‐Claude , Berman Leonard , Gunvén Peter , Klein Eva
Published: February 2007

The antigenicity of Murine Sarcoma Virus (MSV) transformed mouse, rat and hamster cells has been studied by several techniques designed to detect surface antigens. Antigens were readily demonstrated on neoplastic mouse and rat cells. There was complete cross‐reactivity between cells induced by the Harvey (MSV‐H) or Moloney (MSV‐M) strains of MSV and by Moloney Leukemia Virus (MLV). No evidence of a distinct or separate „MSV‐non‐MLV”︁ antigen could be obtained by cross absorptions of MSV/MLV antisera and cells, or by tests designed to break MLV tolerance. Such results favor the view that MSV and MLV are closely related entities.

With the 8303 line of MSV‐M transformed hamster cells serological tests revealed little if any reactivity with strongly positive mouse anti‐MSV/MLV antisera. In one test, however, immunization of mice with these cells gave some degree of protection against syngeneic MSV sarcoma.
Some factors affecting carbohydrate metabolism in hepatic tissues of different growth rates
Authors: Lea M. A. , Sasovetz D. , Morris H. P.
Published: February 2007

Aspects of carbohydrate metabolism, namely glycogen concentration, glucokinase activity, hexokinase activity, lactate and α‐glycerophosphate production, were compared with growth rate in regenerating liver and two transplantable hepatomas (5123‐D and 7777). Lactate production with glucose as substrate was greater with whole homogenates than with supernatant fractions for the hepatomas but the reverse was the case with control, sham‐operated and regenerating liver. Nicotinamide had a greater effect on lactate production by homogenates of normal and regenerating liver than with tumor homogenates. The effect of nicotinamide was correlated with the NAD glycohydrolase activity of homogenates and supernatant fractions of the different tissues. It was suggested that changes in carbohydrate metabolism in regenerating liver show some resemblance to those observed in hepatomas of similar growth rate but more marked changes may be seen in the tumor tissues.
Antigènes nouveaux dans les cellules transformées par le SV40. I. Mise en évidence de trois nouveaux constituants antigéniques dans plusieurs lignées cellulaires d'origines différentes transformées par le SV40
Authors: Cyr Ch. De Vaux Saint , Herbet A. , Sobczak E. , Grabar R. Wicker Et P.
Published: February 2007

L'emploi de réactions en gélose permet de comparer les constituants solublcs de plusieurs lignées de cellules d'origines diffkrentes transformées les unes par le SV40, les autres spontanément ou par d'autres virus oncogènes. Les antisérunis préparés chez h inpin et chez le hamster, spécifiques pour un clone de cellules (TSV5Cl2) transforméAes par le SV40 mettent en évidence trois nouveaux constituants antigéniques dans toutes les souches de cellules transformées par le SV40 (hamster, souris, rat, chien) quelle que soit l'espèce d'origine. Ces constituants sont différents de l'antigène T du noyau et probablement de l'antigène de transplantation.
New antigens in cells transformed by the SV40 virus. II. Evidence of their cytoplasmic localization in a cell line (TSV5 CL2) of hamster fibroblasts transformed by SV40
Authors: Tilz G. P. , Cyr Ch. De Vaux Saint , Grabar P.
Published: February 2007

A clone of hamster fibroblasts transformed by SV40 virus (TSV5 CL2) induced antibodies in hamsters against new antigenic constituents not present in the untransformed fibroblasts. The antibodies in the immune sera against histocompatibility antigens and those against nuclear T antigen were absorbed. The absorbed sera contained antibodies which agglutinated the transformed cells. The sera contained also precipitating antibodies against new antigens present in a crude extract of TSV5 CL2. These antibodies were directed to common new antigens present in SV40‐transformed fibroblasts from different species. Immunofluorescence and the “indirect enzyme‐labelled antibody technique” were used for the cellular localization of the antigens corresponding to the precipitating antibodies. Both techniques showed that these antigens were localized in the cytoplasm, mostly in the microsome‐ribosomal fractions, much less on the cell membrane and not at all in the nucleus.
Biological activity and separation of a leukaemogenic virus from murine sarcoma virus‐harvey (MSV‐H)
Authors: Harvey Jennifer J. , East June
Published: February 2007

Twelve different preparations of Murine Sarcoma Virus‐Harvey (MSV‐H) had leukaemogenic activity when tested in BALB/c and C3H/Bi mice or Sprague‐Dawley rats, some of which ultimately developed generalized lymphocytic leukaemia instead of reacting rapidly and characteristically with sarcoma formation and/or erythroblastic splenomegaly. Inactivation of MSV‐H by ether treatment, reducing its titre by dilution, and using the intramuscular route of injection, all biased towards leukaemogenesis. The leukaemogenic component could be separated by vertical transmission from three MSV‐H‐infected female mice, which themselves showed only sarcomas and/or splenic erythroblastosis, to as many as six successive generations of their untreated offspring. Presence of a leukaemogenic virus, probably MLV, was confirmed by serial passage of plasma filtrates from leukaemic animals, including leukaemic progeny, in newborn mice and rats. Lymphocytic leukaemia developed exclusively in these recipients and in those given a plasma concentrate. Moreover, pre‐treatment with the leukaemogenic virus enhanced the oncogenicity of MSV‐H in 8‐ and 14‐day‐old mice, as judged by an increased incidence of sarcomas. Pathological changes in the kidneys of the leukaemic mice are also described, which probably represent an immune deposit lesion related to the deposition of circulating complexes of viral antigen and anti‐viral antibody on the basement membranes of the glomerular capillaries.
Rous sarcoma virus production in mixed cultures of mammalian rous sarcoma cells and chick embryo cells
Authors: Yamaguchi N. , Takeuchi M. , Yamamoto T.
Published: February 2007

The induction of Rous sarcoma virus (RSV) production was analyzed in mixed cultures of mouse or hamster Rous sarcoma cells and chick embryo cells treated with ultraviolet inactivated hemagglutinating virus of Japan (UV‐HVJ). The pre‐treatment of UV‐HVJ with a certain concentration of anti‐HVJ serum increased the yield of infectious RSV in mixed cultures enabling a quantitative analysis of this phenomenon to be made. RSV‐inducing ability of a mixture of HVJ and anti‐HVJ serum was affected by the concentration of anti‐HVJ serum and showed changes in parallel with the cell fusion activity of the mixture. The effect of UV‐HVJ on RSV induction was not achieved by incubation of the cell mixture at 0° C as it was after shaking at 37° C. These findings suggest that the production of infectious RSV in mixed cultures may be initiated in heterokaryons of mammalian Rous sarcoma cells and chick embryo cells. The number of infective centers in mixed cultures was, however, as small as 1% of that of heterokaryons. It is possible that only a small fraction of the heterokaryon population is productive of infectious RSV.
Murine sarcoma virus: Titration patterns and interference by a murine leukemia virus
Authors: Somers K. D. , Kirsten W. H.
Published: February 2007

A murine sarcoma virus (MSV‐K) was assayed by conversion of 3T3 mouse cells into foci of morphologically altered cells. Murine erythroblastosis virus (MEV), a member of the murine leukemia virus group, induced resistance in 3T3 cultures specific to super‐infection with focus‐forming MSV‐K. Interference by MEV was first detected at 14 days and reached maximal levels 21 days post infection. MSV‐K preparations from transformed 3T3 cells contained competent virions, as judged by “one‐hit” titration patterns. Since excess “helper” MEV in MSV‐K stocks could effectively convert titration patterns to “one‐hit” kinetics, the ratio of MEV to MSV‐K was determined by interference experiments. The ratio of MEV to MSV was approximately 10:1. Thus it appears that a single particle is capable of producing a focus of altered cells in the absence of simultaneous infection with a separate particle of MEV.
Thoracic duct lymph cytology in Hodgkin's disease
Authors: Engeset A. , Höeg K. , Höst H. , Liverud K. , Nesheim A.
Published: February 2007

Sternberg‐Reed cells were demonstrated in seven out of 10 patients with Hodgkin's disease by catheterization of the thoracic duct.

In two patients with normal para‐aortic nodes on lymphangiography no Sternberg‐Reed cells were seen in the thoracic duct lymph.

In one patient the diagnosis of abdominal Hodgkin's disease was established by thoracic duct lymph examination.
Metabolism and binding to cellular macromolecules of a series of hydrocarbons by mouse embryo cells in culture
Authors: Duncan Margaret , Brookes P. , Dipple A.
Published: February 2007

A series of eight tritium‐labelled polycyclic hydrocarbons were incubated in the presence of monolayer cultures of primary mouse embryo cells, and the time‐course of their metabolism to water‐soluble derivatives was studied. All the hydrocarbons, both carcinogenic and non‐carcinogenic, were metabolized at approximately the same rate when a low concentration of the order of 0.05 μM was used. The binding of the various hydrocarbons to cellular DNA, RNA and protein was determined and a “binding index” calculated, i.e., the extent of reaction of the hydrocarbon with the particular macromolecule resulting from the metabolism of 1 mμmole of hydrocarbon per ml of medium to which the cells were exposed. While no very significant difference between the various hydrocarbons was found for the protein binding index, the DNA and RNA binding indices divided the compounds into two groups. One group with a high binding index consisted of potent carcinogens while the other group had much lower (one tenth) values for the binding index. With the exception of dibenz[a, h]anthracene, this latter group consisted of non‐carcinogens.
Studies on murine sarcoma virus; A morphological comparison of tumorigenesis by the harvey and moloney strains in mice, and the establishment of tumor cell lines
Authors: Berman L. D. , Allison A. C.
Published: February 2007

Anatomic lesions produced by the Moloney and Harvey strains of Murine Sarcoma Virus (MSV‐M and MSV‐H) in mice have been compared. Erythroblastic splenomegaly is a distinctive feature of disease produced by MSV‐H. Solid tumors induced by both viruses were quite similar in morphology, although some consistent differences were noted. The tumors appear to arise by massive recruitment of primitive mesenchymal cells rather than by clonal proliferation. The morphological features of these lesions would suggest that, although MSV‐M and MSV‐H are similar entities, they are not quite identical.

Four transplant lines have been established from the mouse tumors; three MSV‐H and one MSV‐M. The MSV‐M line (CBA strain) was initiated with difficulty and did not release sarcoma virus. The MSV‐H lines (two CBA and one BALB/c) were easier to initiate and virus release was demonstrated both in vivo and in vitro. In addition to tumor growth at the site of implantation, the BALB/c line also produced splenic erythroblastosis. The MSV‐M and one of the MSV‐H CBA lines underwent a distinctive alteration during the course of in vivo passage in which the original spindle‐cell lesion evolved into an undifferentiated small‐cell tumor.
Titrage de la tumorigénicité des cellules transformées sur la membrane chorio‐allantoïdienne de l'oeuf de poule
Authors: Vigier P.
Published: February 2007

Les suspensions monodispersées de cellules transjormées de cultures in vitro produisent des tumeurs par inoculation sur la membrane chorio‐allantoïlienne d'aufs de poule emhryonnés. La tumorigénicité (transplantahilité sur la MCA) pelit être titrée énumérativement en comptant Irs tumeurs produites en 7 jours sur la MCA d'æufs de 11 jours. La distribution des nombres de turneurs est logarithmico‐normale, et les nombres moyens sont proportionriels uu rtombre de cellules inoculkes lorsqu'ils sont faibles (moins de 10). L'erreur décroit avec I'augmentation du nomhre d'æufs, et des intervalles de confance 95% inférieurs à 0.48 log10, ant été obtrtius dans les séries de plus de 10 æufs. Les titrages sont reproductibles, et le nombre moyen de cellules requis pour produire une tumeur (DT) est gétiéralement resté constant dans les lignées clonales établies, re qui suggère que c'est un caractère génétique stable des ce1lules. Cependant, dans certaines lignées, la DT a dimitiué jrrsqu'à un palier inférieur, satis doute par sélection de variants à tumorigénicité augmetitée. La DT des cellules transfimiées et établies de rongeurs Péait généralement inférieure á celle des cellriles transformées mais à vie limitée de primates, et une ligriée de cellules humaines morphologiqirement transformées n'a, mêmes, pas donné de tumeurs. Des tumeurs ont aussi été obtenues avec les cellules de hamster non transformées mais étahlies BHK21/13, mais pas avec les cellules diploïdes non transformérs et non établies de primates ou de poule. La DT des cellules BHK21 transformées et non trawsformées est plus élevée que la DT50 des mêmes cellules chez le Hamster syrien, mais elk lui est proportionnelle.
The pattern of protein synthesis in SV40‐infected CV‐1 cells
Authors: Fischer Hans , Munk Klaus
Published: February 2007

The time sequence of induced proteins after SV40 infection has been studied by polyacrylamide gel electrophoresis. The alteration of the protein pattern has been followed in stained gels of protein preparations and in gels of protein preparations after pulse labelling cells with 14C amino acids. The proteins of cell extracts were prepared either by precipitation at 60% ammonium sulfate saturation or by disintegration with 8 M urea. The precipitated protein pattern was altered after infection in correlation with the changes in pattern of incorporated isotopes. New bands and increases in bands present in control cultures were observed. After urea treatment the particulate protein pattern revealed three new peaks at 15 h after infection. The most significant alterations, compared to the uninfected CV‐1 cells, occurred at 32 h post infection. Three complexes, peaks 3–8, 10–13, and 14–17, and peak 23 increased at this time. Protein synthetic activity in these areas was confirmed by the electrophoresis of pulse‐labelled proteins.
Immune response to urinary bladder tumours in man
Authors: Bubenïk J. , Perlmann P. , Helmstein K. , Moberger G.
Published: February 2007

A microassay in disposable tissue culture plates was used to demonstrate a cell‐mediated immune response against human urinary bladder carcinoma. Leukocytes isolated from peripheral blood of patients with urinary bladder tumours were allowed to react in vitro with cells of bladder tumours, or with a control tumour or normal cells. Both autochthonous and allogeneic leukocytes from patients with bladder tumours strongly reduced the number of plated bladder tumour cells as compared to control leukocytes, but did not affect control tumour or normal cells. No significant cytotoxic effects were produced by control leukocyte suspensions from a patient with prostatic carcinoma, from patients with non‐neoplastic diseases or from normal healthy individuals.

The results indicate that human urinary bladder tumours possess tumour‐specific antigens which cross‐react with each other.
Biochemical studies on growth‐inhibitory bisdioxopiperazines. I. Effect on dna, rna and protein synthesis in mouse‐embryo fibroblasts
Authors: Creighton A. M. , Birnie G. D.
Published: February 2007

A number of bisdioxopiperazines have recently been shown to possess marked growth‐inhibitory activity against a range of experimental tumours in mice and rats. These compounds were originally designed as potential intracellularly activated chelating agents. In the present investigation, two of these compounds (±)‐1,2‐bis (3,5‐dioxopiperazin‐1‐yl) propane (ICRF 159) and meso ‐2,3‐bis (3,5‐dioxopiperazin‐1‐yl) butane (ICRF 193) have been shown to be potent inhibitors of DNA synthesis in growing mouse‐embryo fibroblasts while having relatively little effect on RNA and protein synthesis. In this respect, their behaviour strongly resembles that of radiomimetic drugs and ionizing radiation. X‐rays and both ICRF 159 and ICRF 193 exhibit a very similar pattern for the time‐course of the inhibition of 3H‐thymidine uptake into DNA. They all show a recovery taking place about 4 h after the initial treatment (presumably due to repair and/or stimulation of unscheduled DNA synthesis) followed later by a more substantial and permanent inhibition. In view of the structure of these compounds, it is possible that they may be exerting a radiomimetic effect by acting as mono‐ or bi‐functional acylating agents.
Structural proteins of murine erythroblastosis virus
Authors: McDugald L. V. , Panem S. , Kirsten W. H.
Published: February 2007

3H‐amino‐acid labelled murine erythroblastosis virus (MEV) was harvested from the EMS cell line and purified by centrifugation in sucrose or potassium‐citrate gradients. 3H‐amino‐acid labelled nucleoids were isolated from MEV by the tween‐ether method. Proteins were solubilized from whole MEV and MEV‐nucleoids. Electrophoresis in polyacrylamide gels of pH 7.2 in 0.5 M urea for 17 h yielded three major peaks of radioactivity from whole MEV preparations. These proteins were referred to as MEV‐1, MEV‐2 and MEV‐3. In addition, two minor protein peaks, MEV‐a and MEV‐b, were recovered from whole MEV. Only two major peaks, MEV‐1 and MEV‐2, and one minor component, MEV‐a, were found in electropherograms of MEV‐nucleoids. The results were reproducible with MEV progeny harvested from later subcultures of EMS cells. The results suggested that MEV‐3 and MEV‐b were structural proteins of either the virion coat or the internal virion structure.
A new virus of minimal pathogenicity associated with friend virus. I. Isolation by end‐point dilution
Authors: Rowson K. E. K. , Parr Iris B.
Published: February 2007

In an attempt to purify a strain of Friend virus (FV) by passage in mice at end‐point dilution, we injected groups of BALB/c mice with ten‐fold dilutions of the virus. After 3 weeks, plasma was collected from each mouse and the spleen weighed. Mice given virus diluted 10−7 and untreated controls had spleens weighing between 100 and 120 mg. Of the six mice given virus diluted 10−1, two had spleens weighing over 200 mg; plasma samples from both of these and from two mice of the same group, which had normal sized spleens, were tested in mice. After 3 weeks, only the recipients of plasma from mice with splenomegaly had enlarged spleens (200–350 mg). The virus obtained by end‐point dilution is referred to in this paper as the Rowson‐Parr virus (RPV). It has been passaged by plasma seven times at 3‐weekly intervals and regularly produces splenomegaly of a minor degree which does not progress. The virus is present in the plasma of infected animals for at least 122 days and the spleen does not return to normal but the infection is not lethal. Mice infected with RPV develop gross splenomegaly following a subsequent injection of FV but the disease progresses more slowly than in mice infected with FV alone. Neutralizing FV antibodies could not be demonstrated in the plasma of RPV infected mice. On filtration through gradocol membranes RPV appeared to be the same size as FV. It was chloroform sensitive, resistant to terramycin and did not affect the plasma lactate dehydrogenase level of infected mice.
A new virus of minimal pathogenicity associated with friend virus. II. Histological changes and immunodepressive effect
Authors: Carter R. L. , Chesterman F. C. , Rowson K. E. K. , Salaman M. H. , Wedderburn N.
Published: February 2007

Histological reactions induced in BALB/c mice by a new virus with minimal pathogenic action — the Rowson‐Parr virus (RPV) — are described. The changes were virtually confined to the spleen and consisted of moderate splenomegaly (200–350 mg) associated with hyperplasia of the red pulp, particularly in the perifollicular zones, and enlargement and activation of the germinal centres. No proliferation of plasma cells was noted at any time. These changes persisted (with minor fluctuations) for 6 months or more, but are described in detail for only the first 3 weeks in the present account. A severe depression of the immune response to sheep erythrocytes was observed between the 2nd and 6th days after infection; a more moderate immunodepression was detected up to 6 months or more after infection. The significance of these findings is discussed.
Diethylnitrosamine oncogenesis in RF mice as influenced by variations in cumulative dose
Authors: Clapp N. K. , Craig A. W. , Toya R. E.
Published: February 2007

Diethylnitrosamine (DEN) was given to male RF mice in the drinking water at levels of 2–11.5 mg/kg body weight daily for varying periods; cumulative doses ranged from 57 to 943 mg/kg body weight. In all treated groups, incidences of lung adenomas, hepatomas, and forestomach squamous cell carcinomas exceeded those in controls; maximum incidences reached 84%, 98%, and 100%, respectively, as compared with control values of 41%, 5%, and 0%. At lower doses, incidence of liver tumors increased linearly with dose, reaching 80–90% at DEN doses of 300 mg/kg and above, whereas the lowest dose of DEN induced a maximum incidence of lung tumors. Only at the lowest dose did DEN fail to induce a maximum incidence of stomach tumors. The mean survival time, mean age at death with all types of tumors, and minimum induction times decreased with increasing dose. DEN did not exert a leukemogenic effect at the doses used, and an inhibitory effect is even suggested: only 1/371 (0.3%) DEN‐treated mice developed myeloid leukemia and 4/371 (1%) thymic lymphoma, compared with control values of 7/162 (4%) and 6/162 (3.7%), respectively. At the lowest dose used, the lung appears most sensitive (maximum tumor induction), the stomach intermediate in sensitivity, and the liver least sensitive to DEN‐oncogenesis.
Cancer of the oesophagus: Further evidence of the relation to drinking habits in France
Authors: Tuyns A. J.
Published: February 2007

Previous studies have shown a correlation between mortality from cancer of the oesophagus and that from “alcoholism” and cirrhosis. It is now shown that the correlation is greater with the former than with the latter; as “alcoholism” deaths occur rather in spirit drinkers, this correlation may indicate that it is for this category of drinkers that the risk of oesophageal cancer is greatest. The pattern of the geographic relation between “alcoholism” and oesophageal cancer is consistent with the hypothesis that spirit drinking is a necessary but not a sufficient condition for the development of oesophageal cancer.
Prolactin and mammary gland carcinogenesis. The problem of human prolactin
Authors: Boot L. M.
Published: February 2007

The ultimate objective of experimental cancer research must be to apply the findings obtained to the prevention or treatment of the disease in humans. In this review it is shown that prolactin is suspected of being one of the hormones mainly responsible for the development of mammary carcinoma in mice. Investigations into the question of whether this might also be true in man are hampered by the fact that the existence of prolactin in this species is still a matter of debate. Because of the intrinsic prolactin‐like activity of purified human growth hormone, the need for the presence of prolactin as a separate hormone might be questioned. It is shown, however, on the basis of a number of biological arguments and clinical observations, that it is extremely unlikely that all prolactin‐like effects in man are due to one of the manifold activities of growth hormone alone; consequently the urgent need to analyse the role of prolactin as a separate hormone in man becomes evident, especially in the field of breast cancer. Tentatively, ways are indicated by which this objective might be reached.
Detection of specific surface antigens by colony inhibition in cells transformed by papovavirus SV40
Authors: Tevethia Satvir S. , Crouch Norman A. , Melnick Joseph L. , Rapp Fred
Published: February 2007

Specific antigens at the surface of SV40‐transformed hamster cells were demonstrated by the in vitro colony inhibition and immunofluorescence tests. Antisera were prepared by inoculating hamsters either with purified SV40 or with human or marmoset SV40‐transformed cells. The inhibition of colony formation by the transformed cells ranged from 46 to 100% in the presence of specific antibody and complement. Nontransformed hamster cells were not inhibited by the immune sera.

Of the 22 sera tested, 12 were positive in the colony inhibition test and 14 were positive in the immunofluorescence test. Eleven of the 22 sera tested were positive in both tests. This positive correlation between the colony inhibition and immunofluorescence tests suggests that the two tests are detecting the same or similar antigens.
In vitro cultivation of the mouse mammary tumor virus: Correlation of infectivity and morphology with radioisotope studies
Authors: Cardiff Robert D. , Blair Phyllis B.
Published: February 2007

Organ and cell cultures of BALB/cfC3H mammary tumor tissue release infectious MTV into the medium. Not only were bioassays of culture fluid for MTV positive, but also radioisotope‐labelled MTV‐RNA and MTV B‐particle antigenicity could be detected in the culture fluid. In addition, type B virus particles were found budding from the cell membranes. Bioassays of control MTV‐free BALB/c tumor cultures were negative, as were radio‐chemical, immunological and morphological studies. Thus, infectivity could be correlated to the presence of labelled B particles in the cultures.
Morphologic and cytogenetic studies in vitro of surface‐adherent lymphoreticular cells derived from burkitt lymphoma tissue
Authors: Rabson A. S. , Chu E. W. , Berezesky I. K. , Legallais F. Y. , Grimley P. M.
Published: February 2007

A line of lymphoreticular cells (AL‐1‐G) that can adhere to glass surfaces has been derived from suspension cultures of Burkitt lymphoma cells (AL‐1). By light microscopy, the predominant cell type in the AL‐1‐G cultures has features of a neoplastic histiocyte and ultrastructurally these cells have more elaborate development of cytoplasmic organelles, such as elements of the Golgi complex and mitochondria, than the predominant cell types in the suspension cultures of AL‐1. Cytogenetically, the percentage of polyploid cells in the AL‐1‐G cultures increased progressively from 39% in 1967 to 100% in 1968 and 1969, while the percentage of polyploid cells in the suspension cultures remained between 12 and 24% during the same period. No herpesvirus or any other type of viral particle was found in the AL‐1‐G cultures on repeated electron microscopic examination.
Altered glucose transport kinetics in murine sarcoma virus‐transformed BALB/3T3 clones
Authors: Hatanaka Masakazu , Todaro George J. , Gilden Raymond V.
Published: February 2007

The kinetics of glucose transport were determined for a number of spontaneous and virus‐transformed cell lines derived from a single clone of BALB/3T3 cells. SV40‐transformed and mouse leukemia virus‐infected cells were characterized by a Km very similar to that of the parental cell line. In contrast, murine sarcoma virus‐transformed cells had a much lower Km. These findings are in agreement with previous results obtained with mass cultures of NIH Swiss mouse embryo cells. One X‐irradiation and two spontaneous transformants also showed low Km values and no virions or virion antigens. These latter cell lines should provide an opportunity for a crucial test of the relationship between glucose transport kinetics and a functional sarcoma virus genome.
Effect of withaferin a on ehrlich ascites tumor cells — cytological observations
Authors: Shohat Batia , Gitter Simon , Lave David
Published: February 2007

Withaferin A, a steroidal lactone with carcinostatic properties, isolated from the leaves of Withania somnifera Dun., produced a mitotic arrest in the metaphase of dividing Ehrlich ascites carcinoma cells. In addition this compound also induced vacuolization of the cytoplasm. A single dose of withaferin A, administered 24 hours after Ehrlich ascites implantation, caused growth reduction followed by disappearance of the tumor in 80% of the mice. These mice were found to be resistant to rechallenge with Ehrlich ascites tumor cells. The inhibition of Ehrlich ascites tumor growth is thought to represent a combined effect of withaferin A action and immune reactions.
Comparative studies on distribution of DMBA‐3H and 7‐hydroxy‐DMBA‐3H and their carcinogenic activity
Authors: Flesher James W. , Syndor Katherine L.
Published: February 2007

Radioactivity in selected tissues was measured 24 and 72 h after a single feeding of DMBA‐3H or 7‐hydroxy‐DMBA‐3H to female Sprague‐Dawley strain rats, aged 50 days. The concentration of radioactivity per gram of mammary tissue 24 h after a single 5‐, 10‐ or 20‐mg dose of DMBA‐3H was equivalent to 3.2, 6.4 and 15.5 μ respectively. The concentration of radioactivity after 20 mg 7‐hydroxy‐DMBA‐3H was equivalent to 4.8 μ of unchanged hydrocarbon. After a single feeding of 5, 10 or 20 mg of DMBA the incidence of breast cancer was 27, 72, and 100% respectively; after 20 mg 7‐hydroxy‐DMBA, it was 45%. These observations indicate that the level of hydrocarbon in mammary fat is one of the critical determinants for induction of breast cancer. In addition to breast cancer, the 7‐hydroxymethyl compound induced nephroblastoma, lung cancer, and leukemia. These observations support the hypothesis that 7‐hydroxy‐DMBA, a metabolite of DMBA, is more closely related to the proximate carcinogen than the parent compound.
Immune‐depressive effect of urethan on the homograft response in mice
Authors: Parmiani Giorgio
Published: February 2007

The effect of a multiple administration of urethan on cellular immunity was tested in young mice. Two different systems were used, the rejection of coisogenic and allogeneic skin grafts and the growth of an antigenic 3‐methylcholanthrene (MCA)‐induced sarcoma isograft. The urethan immune depression appears to be confined to the reaction against weak histocompatibility antigens, since the drug was able to prolong the C57BL/6 male to female skin graft rejection and to impair the immunological capacity in mice transplanted with an isogenic, highly antigenic, MCA‐induced sarcoma. On the contrary, the urethan was ineffective when tested in a strong antigenic difference. The implications for the possible mechanism of urethan carcinogenesis are discussed.
Hodgkin's disease: A correlation of histopathology with survival
Authors: Gough J.
Published: February 2007

Biopsy samples from 96 cases of Hodgkin's disease have been subdivided into four groups based on the histological classification suggested at the Rye Conference on The Obstacles to the Control of Hodgkin's Disease held in Rye, New York, in 1965. The four groups, namely, lymphocytic predominance, nodular sclerosis, mixed cellularity, and lymphocytic depletion are shown to be associated with 5‐year survival rates of 58%, 45%, 18% and 8% respectively, as calculated by the life table method. The anatomical extent of the disease has also been shown to influence prognosis, 5‐year survival rates being 42%, 30%, 6% and 0% respectively for the four clinical stages described.
On the epidemiology of nasopharyngeal carcinoma
Authors: Clifford Peter
Published: February 2007

The incidence of nasopharyngeal carcinoma is high in Chinese in South East China and in those living in a traditional Chinese manner in the countries of South East Asia. The related Mongoloid peoples of Japan and Korea have a low incidence, as do the Caucasians of Europe, America and India. In Chinese born abroad and living in a “Western”‐type environment in Australia, Hawaii and California the incidence falls significantly. This suggests that the high incidence in the Chinese relates to a genetically determined racial or “line” predisposition combined with environmental factors or to environmental factors alone. In Kenya, ethnic origin does not relate to incidence which depends on environmental factors only. The possible significance of genetic factors cannot be assessed until adequate information on the genetic profiles of racial groups with high and low incidences is available.

Different environmental factors may be of importance. Biologic agents such as fungi or viruses may be of importance in some areas, in others a physical or chemical agent may be of significance, or the cancer may arise following exposure to a combination of factors. In some areas inhalation of polynuclear hydrocarbons may be of importance, in others the ingestion of nitrosamine‐like compounds, and these external agents may only be effective if combined with a viral infection, possibly the Epstein‐Barr virus or with a particular nutritional or hormonal status.

The local tissue sensitivity is the factor which determines the response to any particular external agent. Examination of the external environment is, perhaps, of less importance than that of the milieu intérieur, as it is now recognized that the stability of the respiratory epithelium is affected by hormonal and nutritional factors. Universally the incidence in men is higher than in women, and this may relate to their different internal environments.
Cellular and humoral immune responses to human urinary bladder carcinomas
Authors: Bubenïk J. , Perlmann P. , Helmstein K. , Moberger G.
Published: February 2007

Leukocytes from 17 of 19 patients with urinary bladder carcinomas were cytotoxic for autochthonous as well as allogeneic bladder carcinoma cells in vitro. The cells from all 11 individual bladder carcinomas studied were susceptible to this cytotoxic action of patients' leukocytes. In contrast, no cytotoxicity was observed when cells from unrelated tumours or various normal tissues were used as target cells. Purified blood lymphocytes from patients whose leukocytes were active, were also cytotoxic.

Sera of 8 out of 13 patients with bladder carcinomas contained complement‐dependent antibodies which were cytotoxic for autochthonous and allogeneic bladder tumour cells. When serum was taken from the same patient on different occasions over a period of 8 months cytotoxicity was found in some samples but not in others. Sera from 4 out of 9 patients exhibited a blocking activity, which completely abolished the cytotoxic effects of patients' leukocytes. The serum of one out of 9 patients contained antibodies which were not cytotoxic without leukocytes but which conferred a cytotoxic activity onto leukocytes from control subjects. This opsonizing antibody was complement‐dependent and probably of IgM nature.

The effect of hydrostatic pressure therapy on the immune state of the patients was followed by examination of the leukocytes from 16 patients with bladder carcinoma. Leukocytes from 10 patients were cytotoxic before as well as after the pressure treatment. Leukocytes from six patients did not react before the treatment while those from four became active after treatment. A more detailed study of three individual cases indicated that cytotoxicity of the leukocytes appeared after pressure treatment and was of relatively short duration (approximately 1 month). In one case, the development of cytotoxic antibodies was similar. The patient who had opsonizing antibodies had no cytotoxic antibodies. The opsonizing antibodies appeared when the cytotoxicity of the leukocytes decreased.
Carcinogenesis by RNA sarcoma viruses. XIV. Infection of stationary cultures with murine sarcoma virus (harvey)
Authors: Murray R. K. , Temin H. M.
Published: February 2007

No focus‐forming virus was produced after exposure of stationary mouse embryo cell cultures (achieved by removal of serum) to the marine sarcoma virus (Harvey) complex. Addition of serum to these infected stationary cultures resulted in MSV (Harvey) production following cell division. Cytosine arabinoside, an inhibitor of DNA synthesis, was found to inhibit subsequent virus production when added to stationary cultures immediately after exposure to virus. These results are compatible with a requirement for both cell division and non‐S‐phase DNA synthesis for the production of this virus complex, and show a marked parallelism to results previously obtained with the avian sarcoma complex.
Induction of leukemia in balb mice by allogeneic AKR leukemic cells
Authors: Pasqualini Christiane Dosne , Saal Fortuna , Braylan R. C. , Rabasa S. L.
Published: February 2007

The intrasplenic inoculation of AKR lymphoma cells into 1‐month‐old BALB mice, followed by a syngeneic intraperitoneal passage, led to the development of short‐latency leukemia of host origin within 24 days; the incidence of leukemia averaged 83% in 88 mice. Electron microscopic studies revealed the presence of intracisternal A and extracellular C‐type viral particles in leukemic lymph nodes. These results were obtained with eight AKR lymphoma inocula out of 107 trials and were never observed in BALB controls and with normal AKR spleen inoculum, except in one animal. In the surviving groups, the incidence of long‐latency leukemia, averaging 19 months, was significantly increased to 45% in the 541 mice which had received AKR lymphoma inocula, as compared to 30% in those receiving normal AKR spleen inocula; the latter value was also significantly higher than the 15% spontaneous incidence of the BALB strain. A number of tumors were observed in the experimental groups. Antigenic studies, using the indirect cytotoxic test, demonstrated the presence of the G (Gross) antigen, in both short‐ and long‐latency leukemias.
Absence of thymic involvement in the inhibition of urethan lung adenomagenesis by X‐radiation
Authors: Bartlett Gerald L.
Published: February 2007

Since regional thoracic irradiation involves the thymus, as well as lung tissue, inhibition of urethan lung adenomagenesis by thoracic irradiation might be mediated by radiation damage to the thymus. This paper reports experiments which show that lung tumor induction is not inhibited by surgical removal of the thymus and that the inhibitory effect of radiation is not reversed by grafts of normal thymus tissue. Hence, the thymus is not essential to pulmonary adenomagenesis, and does not mediate the inhibitory effect of radiation.
Distribution of bound tritium from 3h‐diethylnitrosamine in rat tissues
Authors: Rajewsky M. F. , Dauber W.
Published: February 2007

The concentration of bound 3H from diethyl‐(mono‐2‐3H)‐nitrosamine was determined in five different rat tissues as a function of time after single and repeated oral doses of the labelled carcinogen. The recorded curves can be described as two‐component kinetics. Whereas the first component decreased with a half‐life of about 3–6 h, the corresponding value for the second component was approximately 90 h. Two hundred and forty hours after a single 3H‐DEN dose, the highest relative concentration of bound 3H was recorded in the liver (1.00), followed by kidney (0.74), spleen (0.40), small intestine (0.18), and lung (0.14). The capacity of the liver to metabolically activate DEN, as reflected by the tissue‐specific accumulation of bound 3H after repeated 3H‐DEN doses, was not impaired at an advanced stage of hepatocarcinogenesis by DEN.