bluuebunny/crossref_metadata_2025 huggingface dataset:
The investigation of the cellular type of immunity in patients with lymphoproliferative and myeloproliferative diseases
Authors: Libánský J.
Published: February 2007

Delayed hypersenstivity to streptokinase and tuberculin used as antigens, and the capacity to form antibodies to streptokinase, were investigated in various malignant blood diseases and the results were compared with those found in some other diseases and in a control group of healthy subjects.

It was found that anergy similar to that seen in Hodgkin's disease (also confirmed in this work) can be found with regard to two antigens in reticulosarcoma, myeloma, acute leukaemia and chronic myelosis. In myelofibrosis partial anergy was observed only with streptokinase but not with tuberculin antigen. The anergy was in general not correlated with the absolute lymphocyte count in the peripheral blood nor with the treatment given.

The increase in antistreptokinase antibodies after immunization with streptokinase was investigated. This administration of the antigen (secondary response) gave results which did not differ from those in controls in Hodgkin's disease, reticulosarcoma, acute leukaemia and chronic myelosis. In myeloma and especially in chronic lymphatic leukaemia, however, the antibody‐forming capacity was significantly decreased. Thus, the results point to a dissociation in the immunological response: in Hodgkin's disease, reticulosarcoma, acute leukaemia and chronic myelosis, there is a significant decrease in the response of the cellular type with preservation of antibody‐forming power. In myeloma both types of reactions are decreased. In chronic lymphatic leukaemia antibody‐forming capacity is reduced with relatively good preservation of the cellular type of reactivity.

Delayed hypersensitivity to tuberculin was also depressed in patients with sarcoidosis although tested during remission, whereas skin sensitivity to streptokinase was preserved. In patients with pancytopenia the delayed hypersensitivity was only slightly suppressed, but there was a tendency to produce higher antibody titres against streptokinase than in the controls, although the difference was not statistically significant. There were similar findings in patients with autoimmune haemolytic anaemia.
Relationship between previous reproductive history and chemically induced mammary cancer in rats
Authors: Moon Richard C.
Published: February 2007

The relationship between a previous history of multiple pregnancies and/or lactations and 7,12‐dimethylbenz(a)anthracene‐induced mammary carcinogenesis was studied in groups of Sprague‐Dawley rats. All rats received the carcinogen at approximately 6 1/2 months of age. Virgin control rats which did not receive the carcinogen did not develop mammary cancer within 13 months although carcinogen‐fed virgin rats exhibited a mammary cancer incidence of 38.5%. A single pregnancy prior to feeding the carcinogen resulted in a decrease in the incidence and an increase in the mean time of appearance of the first palpable tumor. A single pregnancy followed by a subsequent nursing period reduced the percentage incidence and increased the mean time of appearance of the first palpable tumor when compared to the carcinogen‐fed virgin rats. A further increase in the number of pregnancies and/or lactations did not greatly influence the incidence of mammary cancer nor the number of cancers per rat. The mean time of tumor appearance was, however, increased. These data indicated that the relationship between party and carcinogen‐induced mammary cancer in the rat is similar to that existing in the human female but opposite to that found for the mouse.
Chromosomal changes associated with urethan leukemogenesis in mice
Authors: Colnaghi Maria I. , Porta Giuseppe Della , Parmiani Giorgio , Caprio Guido
Published: February 2007

Normal, preleukemic and leukemic thymuses of CTM, C3Hf, C57BL and SWR mice were examined for their chromosome constitution. In untreated infant and young adult animals deviation from diploidy was rare. During and shortly after a brief course of a highly leukemogenic urethan treatment, little variation in chromosome number was found but diploid metaphases had many different chromosome aberrations which became rare a week after completion of treatment. No deviation from normal was observed in thymuses examined 5 and 11 weeks after urethan. The total analysis of 77 thymic lymphosarcomas showed a 40–41 bimodal distribution, although 7 cases had 80% or more diploid metaphases and 3 had 80% or more metaphases with 41 chromosomes. The additional chromosome was always identical or similar to those of the smallest pair.
Transplantable mouse tumor line induced by injection of SV40‐transformed mouse kidney cells
Authors: Kit Saul , Kurimura T. , Dubbs D. R.
Published: February 2007

A transplantable tumor of inbred mice was obtained by inoculating BALB/c mice subcutaneously with SV40‐transformed mouse kidney (mKS‐A) cells. Tumors were produced by mKS‐A cells in the 71st cell culture passage, but not by cells in the 26th passage. The tumor line has been serially passed in BALB/c mice 14 times. In vitro cell culture lines were derived from tumors after 1, 2, 8, 10 and 12 passages in mice. The tumors, as well as the In vitro tumor cell lines, contained SV40 T‐antigen, and sera from the tumor‐bearing mice contained antibodies to the SV40 T‐antigen. SV40 was rescued from the In vitro tumor cell lines after fusion with green monkey kidney (CV‐1) cells in the presence of UV‐irradiated Sendai virus.

The In vitro tumor cell lines derived from mouse passages 8, 10 and 12 were used as SV40 virus; 2) SV40‐transformed cell lines; 3) primary mouse (BALB/c or Yale Swiss) kidney cells, or 4) primary mouse (BALB/c or Yale Swiss) embryo cells. These results showed that the tumor line and the In vitro tumor cell lines have the transplantation antigen.
Immunology of spontaneously arising rat mammary adenocarcinomas
Authors: Baldwin R. W. , Embleton M. J.
Published: February 2007

The immunogenicities of nine spontaneously arising mammary adenocarcinomas were assessed following pre‐treatment of syngeneic female rats with heavily irradiated tumour or excision of subcutaneously developing tumour grafts. One tumour (SP4) was moderately immunogenic and a weaker level of resistance could be evoked against two others. With these three examples, induced resistance was specific to the immunizing tumour and no instances of antigenic cross‐reaction were detected. No resistance could be induced against the remaining tumours, even though challenge inocula of as few as 102 or 103 cells were tested in pre‐irradiated hosts. There was no correlation in this series between tumour immunogenicity and latent period of development.

Peritoneal exudate cells from rats immune to tumour Sp4 were shown to suppress the growth of this tumour in normal pre‐irradiated recipients, but relatively large numbers of immune cells were necessary and their effectiveness was not consistent, factors which reflect the low immunogenicity of the tumour. These peritoneal cells had no influence on the growth of any other of the spontaneous rat mammary adenocarcinomas, further confirming the individuality of the TSTAs on tumour SP4.
Pathogenesis of oncogenic simian adenoviruses. IV. The histopathology and ultrastructure of intraperitoneal neoplasms induced by SV20
Authors: Merkow Leonard P. , Slifkin Malcolm , Pardo Matias , Rapoza Norbert P.
Published: February 2007

The histopathology and ultrastructure of SV20‐induced intraperitoneal (IP) neoplasms is described and compared to neoplasms induced by this virus administered by the intracranial and subcutaneous routes. SV20‐induced IP neoplasms are relatively undifferentiated and contain two types of tumor giant cells. Dilated rough endoplasmic reticulum was increased, but annulate lamellae were rarely observed in IP neoplasms. Virus‐like particles within the cytoplasm and nuclei of neoplastic cells resembled the original inoculated SV20 virus. Virus particles associated with cisternae of endoplasmic reticulum, nuclear projections, and unusual cytoplasmic bodies with many smaller dense structures were observed. These latter dense structures were attached to the inner and outer surface of cytoplasmic bodies and resembled the nucleoid of virus particles.
Effect of age and sex on the development of neoplasms in wistar rats receiving a single intragastric instillation of 7,12‐dimethylbenz(a)anthracene
Authors: Meranze D. R. , Gruenstein M. , Shimkin M. B.
Published: February 2007

Wistar rats of different age and sex received a single intragastric instillation of 7,12‐dimethylbenz(a)anthracene (DMBA). During the following 16 months, 136 of 284 rats developed 182 tumors, of which half were malignant. Among 98 untreated controls, 8 rats developed tumors, of which 4 were malignant. Among the youngest groups (8–15 days) exposed to DMBA, fibroadenoma of the breast in females and subcutaneous sarcoma in both sexes were the most frequent. Among young adult females (6–8 weeks), mammary carcinoma predominated; older females (26 weeks) had less breast tumors. Among adult males, epidermoid carcinoma and papilloma of the skin were most frequent. Castration suppressed development of breast cancer.
Cell population kinetics in the mouse ovary after treatment with a chemical carcinogen (DMBA)
Authors: Pedersen Torben , Krarup Torben
Published: February 2007

The primary effect of the chemical carcinogen 9,10‐dimethyl‐1,2‐benzanthracene (DMBA) on the mouse ovary is an immediate destruction of the small oocytes. The possible additional effect of DMBA on the cells of the ovary that synthesize DNA, the granulosa cells, was studied. As the proliferation of the granulosa cells determines the speed at which the entire follicle grows and develops, any effect of DMBA on the granulosa cells would alter the follicle growth rate. This was examined in DMBA‐fed mice by autoradiography after pulse labelling with tritiated thymidine.

The labelling index of the granulosa cells in all types of follicles was increased for 1 to 2 weeks after feeding of the carcinogen, whereas the duration of the S‐phase was not significantly affected. Hence the proliferation of the granulosa cells, as well as the growth rate of whole follicles, was temporarily accelerated by the carcinogen. In the large follicles this was due to a shortening of the G1‐phase, while in the medium‐sized follicles an increase of the proliferating fraction of the granulosa cells and/or a shortening of the G1‐phase might have occurred.

Several earlier investigations have shown that DMBA affects cells by depressing their DNA synthesis. The present results suggest that the granulosa cells of mouse ovaries are affected differently by the carcinogen than the cells so far examined. The question is raised whether the stimulation of the follicle growth is caused directly by the carcinogen acting on the granulosa cells as a hormone, or whether the effect is indirect and related either to the reduced oocyte population or to the process of oocyte destruction itself.
Electron microscopy of murine SJL/J disease
Authors: De Tkaczevski Lidia Z. , Wanebo Harold J.
Published: February 2007

SJL/J inbred mice suffering from the neoplastic disease, very young apparently normal animals and mice bearing transplanted tumors were examined. Lymph nodes, spleens and occasionally thymuses, lungs and Peyer's patches were investigated under the electron microscope.

It was found that very young (3‐week‐old) animals with slightly enlarged lymph nodes did not show any cellular or ultrastructural changes, although at the age of 8 weeks there was a certain proliferation of plasma cells. The onset of overt disease was marked by a massive proliferation of plasma cells with simultaneous paraproteinemia in mice sera. If the animal survived this stage of the disease, a regression followed. Although the tumors were still present, plasma cells were no longer abundant and a reticulum cell hyperplasia became evident. In this late period of the disease normal blood proteins or hypogammaglobulinemia were found. Mice with transplanted tumors developed reticulum cell sarcomas and the serum showed either normal proteines or hypogammaglobulinemia.

Intracisternal particles were found repeatedly in the reticulum cells of the transplanted tumors and very occasionally in the spontaneous tumors, during the regression stage. These particles measured about 850 Å in diameter and were composed of a shell formed by two dense rings with a clear space in between, and a lighter central zone. The significance of these particles is discussed.
Cytotoxicity of sera from healthy persons and cancer patients
Authors: Arpels Claude , Southam Chester M.
Published: February 2007

One hundred and forty sera from 68 cancer patients and 34 healthy persons were tested for cytotoxicity against human cell lines HEp2, AdenoCx 1 and Amnion B by using 20% test serum as the only serum in the culture medium and incubating for 5–7 days. Evaluation included cell counts, dye exclusion tests, and qualitative grading of cell growth on a basis of 0 to ++++. Final analyses were based entirely on the qualitative grading. Only sera which caused unequivocal toxicity (0 or + growth) were classified as cytotoxic.

Cytotoxicity was unrelated to the cell line used for the tests. Toxicity gradually diminished during storage at ‐20° C, but reproducibility of repeated tests of the same serum was good if sera were stored less than 3 months. In studies of multiple serum specimens from the same individual, some persons, both cancer patients and healthy controls, showed inconstant toxicity which was not related to any recognized change in the donor's condition or activities. Toxicity was not related to sex or age. Toxicity was much more frequent in sera from patients with leukemia and lymphoma (74%) than in healthy controls (19%) and somewhat more frequent (39%) in sera from patients with other forms of cancer. Amongst the cancer patients toxicity was somewhat less frequent in sera from patients with the most aggressive cancers, but the difference could easily have occurred by chance. Medications (especially cancer chemotherapeutic agents), various„blood chemistry”︁ determinations, and blood counts had no clear relationships to serum toxicity, but the data did not exclude the possibility that certain medications (e.g. daunomycin) and certain metabolic abnormalities (e.g. uremia) cause sera to be toxic. Patients of blood group A more commonly had cytotoxic serum than did group O patients.

The phenomenon of serum cytotoxicity offers no promise as a diagnostic test for cancer because of the frequency of both „false positive”︁ and „false negative”︁ reactions. Neither is it of prognostic value since it was not consistently related to survival or severity of disease. The increased frequency of cytotoxicity in sera from cancer patients as compared to healthy persons is highly significant statistically, but the cause and biological significance of the phenomenon remain an enigma.
Studies on cellular immunity and its serum‐mediated inhibition in moloney‐virus‐induced mouse sarcomas
Authors: Hellström Ingegerd , Hellström Karl Erik
Published: February 2007

A colony‐inhibition technique was used to demonstrate lymph‐node cell (LNC) mediated immune reactions against tumor‐specific transplantation antigens of primary, Moloney sarcoma virus induced mouse sarcomas. Lymph‐node cells from mice in which Moloney sarcomas had regressed spontaneously (regressors), as well as LNC from mice carrying progressively growing tumors (progressors), induced by virus inoculation at an age of 14 days or older, reduced the plating efficiency of Moloney sarcoma target cells.

Serum from mice with progressively growing Moloney sarcomas, but not from mice with spontaneous mammary carcinomas or methylcholanthrene‐induced sarcomas, abrogated the inhibitory effect of regressor LNC on Moloney sarcoma cells. Additional evidence for the specificity of the serum effect was obtained in experiments showing that the protective effect of progressor sera could be specifically removed by absorption with Moloney sarcoma cells. Regressor sera gave no protection against target cell inhibition by regressor LNC. It is suggested that progressor sera contain antibodies which mediate an efferent form of immunological enhancement.
Cellular immunity and its serum‐mediated inhibition in shope‐virus‐induced rabbit papillomas
Authors: Hellström Ingegerd , Evans Charles A. , Hellström Karl Erik
Published: February 2007

A colony‐inhibition technique was used to demonstrate lymph‐node‐cell (LNC) mediated immune reactions against tumor‐specific transplantation antigens of Shope‐virus‐induced papilloma and carcinoma cells. Lymph‐node cells from rabbits in which Shope papillomas had regressed spontaneously, as well as LNC from rabbits with persistent Shope papillomas, reduced the plating efficiency of Shope‐virus‐induced papilloma and carcinoma cells but did not affect normal skin fibroblasts from the same rabbits as the tumor cells.

Serum from rabbits with persistent Shope papillomas or Shope carcinomas abrogated the inhibitory effect of regressor LNC on Shope tumor cells, while serum from regressor rabbits had no such effect. It is postulated that sera from “persistor” and carcinoma rabbits contain antibodies which mediate an efferent form of immunological enhancement.
Ribonuclease‐susceptible charged groups at the surface of ehrlich ascites tumour cells
Authors: Weiss L. , Mayhew E.
Published: February 2007

The electrophoretic mobilities of Ehrlich ascites tumour cells are significantly reduced following treatment with bovine pancreatic ribonuclease. This loss of net surface negativity has been intensively investigated, and has been shown to be due to the enzymatic activity of the ribonuclease, as distinct from non‐specific adsorption of this basic protein.

The experimental data are consistent with the concept that RNA is a structural component of the cell periphery.
Infectious but non‐leukemogenic friend leukemia virus obtained after prolonged cultivation in vitro
Authors: Yoshikura H. , Hirokawa Y. , Ikawa Y. , Sugano H.
Published: February 2007

A non‐leukemogenic strain of Friend leukemia virus (FLV) propagated in vitro interfered with infection by murine sarcoma virus (Moloney) (MSV) and acted as a helper of defective MSV. This suggests that the non‐leukemogenic strain of FLV is infectious. After prolonged propagation in vitro, the leukemogenicity of a highly leukemogenic strain of FLV gradually decreased, while the infectivity assayed by interference with MSV infection remained unchanged.
Prevention of carcinogenesis by murine sarcoma virus (Harvey) following injections of immune sera during the latent period
Authors: Bubeník J. , Turano A. , Fadda G.
Published: February 2007

Several immune sera were prepared by immunization of mice and rats with murine sarcoma virus (MSV‐Harvey) or with irradiated tissue of MSV‐induced tumours.

Repeated injections of these sera into mice and rats which had been inoculated at birth with MSV (Harvey) effectively prevented MSV carcinogenesis. All the immune sera contained antibodies capable of neutralizing MSV. Sera containing the highest titres of virus‐neutralizing antibodies were also the most effective in prevention of MSV carcinogenesis.

Passive transfer of some of these immune sera into adult and newborn mice did not influence the growth of MSV‐induced tumour cells transplanted into syngeneic recipients. Other sera either enhanced or inhibited tumour growth. Because of this no correlation could be established between the effect of sera on tumour growth and their capacity to prevent MSV carcinogenesis.
The inhibition by cytosine arabinoside of the replication of murine leukemia and sarcoma viruses in mouse embryo cultures
Authors: Hirschman Shalom Z. , Fischinger Peter J. , O'Connor Timothy E.
Published: February 2007

Cytosine arabinoside is a potent inhibitor of DNA synthesis in mammalian cells in tissue culture but allows RNA synthesis to proceed. When added to mouse embryo cultures cytosine arabinoside prevented the replication of the Rauscher and Moloney murine leukemia viruses. These viruses were assayed in vitro by the leukemia virus helper assay. After an initial 7‐h exposure of Rauscher‐virus‐infected mouse embryo cells to either 10−5 M or 10−4 M cytosine arabinoside a maximum yield of only 10% of virus compared to control infected cultures was obtained after 48 h of incubation. In a similar experiment with the Moloney leukemia virus only 25–40% of virus was present in cytosine arabinoside‐treated infected cultures at day 7 of incubation when compared to controls. Cytosine arabinoside inhibits the replication of both competent and defective isolates of murine sarcoma virus in mouse embryo cultures. Under similar conditions cytosine arabinoside did not interfere with the growth of vesicular stomatitis virus in mouse embryo cultures.
The formation of variants with a reversion of properties of transformed cells. III. Reversion of the structure of the cell surface membrane
Authors: Inbar Michael , Rabinowitz Zelig , Sachs Leo
Published: February 2007

The cell surface structure of variants from polyoma‐transformed cells grown in animals and then cultured in vitro, which show a reversion of in vitro properties of transformation without losing the ability to synthesize the polyoma‐specific nuclear tumor (T) antigen, has been studied by using the carbohydrate‐binding protein concanavalin A (Con. A) which interacts with sites on the cell surface membrane. Transformed cells are agglutinated by this protein. Normal cells, whose sites for Con. A are mainly in a cryptic form, are agglutinated only after they have been treated with trypsin. It has been shown that some variants showed a partial, and others a complete, loss of agglutinability by Con. A, and that the agglutinability of these variants was restored by treatment with trypsin. Compared to the parental transformed cells, all the variants showed the same decrease in cloning efficiency in fluid medium and soft agar, and in saturation density. The results indicate that the surface structure of transformed cells can completely revert to the structure found in normal cells, as measured by reversion to the cryptic form of sites for Con. A; that the synthesis of T antigen, presumably due to integrated virus DNA, is by itself not sufficient to prevent this reversion; that variants with this reversion in cells grown in vitro can have a high degree of tumorigenicity in animals; and that a threshold for the number of exposed surface sites for Con. A has to be exceeded before the cells express the in vitro properties of transformation.
Studies on plasma membranes. X. A survey of enzyme activities displayed by plasma membranes isolated from mouse liver and three mouse hepatoma strains
Authors: Emmelot P. , Bos C. J.
Published: February 2007

Plasma membranes were isolated from CBA‐mouse liver and three transplanted mouse hepatomas having spontaneously arisen in old CBA males.

The membranes were assayed for enzymes which had previously been demonstrated in isolated rat‐liver plasma membranes. Marked differences in the specific activities of some enzymes (e.g. 5′‐mononucleotidase) of mouse‐ and rat‐liver membranes were noted.

The changes observed in the specific enzyme activities and the stability of certain enzymes of the hepatoma membranes, relative to the corresponding properties of liver membranes, were of three types: (a) those common to all three hepatomas; (b) changes restricted to individual hepatoma strains; and (c) changes developing during the natural history of a given hepatoma strain maintained by transplantation.

It is concluded that tumor individuality and progression are expressed at the level of the plasma membrane enzymes. The number of changes in plasma membrane enzymes of a particular hepatoma relative to liver may serve as a measure of deviation of that tumor from the homologous normal resting tissue, but the impact of these membrane changes on tumor‐cell behavior is unknown.
Smoking patterns in Africans and Indians of natal
Authors: Schonland Mary , Bradshaw Evelyn
Published: February 2007

A high lung cancer rate for African males and a lower rate for Indian males of Durban, Natal, indicated that a study of smoking patterns in Africans and Indians of this region was required.

In Part A, a comparison, in African males, of the smoking habits of 45 lung cancer patients and 90 non‐cancerous patients shows that there is a close association between lung cancer and the amount and duration of smoking in this group.

In Part B, a comparison between 236 African male patients and 130 Indian male patients who did not suffer from cancer indicates that Africans start smoking at an earlier age than Indians, and that the use of home‐rolled cigarettes is more frequent among Africans than among Indians. While a comparison of smoking patterns between younger males indicates that the younger Indian is a heavier smoker than the younger African, a comparison between older males shows that the older Indian male is not a heavy smoker, whereas the older African male is. These differences between Africans and Indians might account for the higher lung cancer incidence in Africans at present.

The greater consumption of tobacco by younger males of both groups than by older males suggests that the incidence of lung cancer may rise in the future. This prediction is based on the assumption that the smoking patterns emerging from this survey reflect the smoking habits of the general population and that the trend towards heavier smoking in younger males will continue. Brief consideration of other factors, such as exposure to occupational carcinogens, pulmonary scarring and domestic air pollution, appears to indicate that Africans are more at risk than Indians for all factors.
Isolation of membrane‐associated tumour‐specific antigen from an aminoazo‐dye‐induced rat hepatoma
Authors: Baldwin R. W. , Moore M.
Published: February 2007

Tumour‐specific antigen on the surface of cells of a transplanted rat hepatoma (D23), originally induced by 4‐dimethylaminoazobenzene, was assayed by its capacity to absorb antibody directed specifically against this component and demonstrable by membrane immunofluorescence tests with viable hepatoma cells in suspension. Quantitative assay of antigen in subcellular fractions of tumour, in comparison with that on intact cells, was obtained by this method, the specificity of antibody absorption being confirmed by the lack of effect of intact cells or subcellular fractions of other rat hepatomas and unrelated tumours.

Homogenization of hepatoma cells by nitrogen cavitation resulted in the release of membrane fractions retaining hepatoma‐D23‐specific antigen, the recovery being 13 to 17% of that expressed on intact tumour cells. Antigen was equally distributed between large‐particle (sedimented at 10,000 × g) and small‐particle (sedimented at 105,000 × g) fractions, indicating that the method of cell rupture produced antigen‐associated membrane fragments of varying size. No antigenic activity was detectable in soluble cytoplasmic fractions of the tumour. These studies demonstrate that tumour‐specific antigen can be isolated in membrane fragments with the same individual specificity as that demonstrated by immunofluorescence staining of intact hepatoma cells with immune serum or by the induction of tumour immunity.
Some factors affecting membrane immunofluorescence reactivity of burkitt lymphoma tissue culture cell lines
Authors: Yata J. , Klein G.
Published: February 2007

Membrane immunofluorescence (MIF) reactivity of Epstein‐Barr virus (EBV) carrying cultured Burkitt's lymphoma (BL) cells with BL sera shows certain fluctuations from time to time, even with standard reference sera and apparently constant tissue culture conditions. In order to determine the culture conditions that are critical for this variation and to establish the optimal situation favoring the production of highly reactive cells, we studied two established BL‐derived cell lines under different conditions of initial cell number, cell density per unit volume or bottom unit area in the culture vessel, depth of the fluid phase, proportion of conditioned medium, etc. Although the two lines behaved somewhat differently, they showed better reactivity when maintained at a high concentration, as long as crowding did not entirely prevent cell multiplication. Under identical conditions of medium supply and depth of the fluid phase, more closely packed cells within a smaller bottom area of the culture vessel exhibited a better MIF reactivity than more dispersed cells. Under different conditions of growth, there was an inverse relationship between the rate of cell multiplication and the percentage of viable MIF‐positive cells. Optimal conditions with steady, high‐level reactivity have been worked out for both lines, but were different with regard to quantitative detail.
Some effects of pH and formaldehyde on the cellular electrokinetic surface
Authors: Weiss L. , Cudney Toni L.
Published: February 2007

When the electrophoretic mobilities of many cells are measured in solutions having pH values in excess of 9, or after formaldehyde‐fixation, there is an increase in their net surface negativity which is usually attributed to deprotonation of amino‐groups at the cell surface. A detailed investigation of the effects of high environmental pH and formaldehyde treatment on cell electrophoretic mobility suggests that the mobility changes are largely due to the adsorption of released intracellular contents to the cell surface and that, contrary to current belief, information obtained by experiments of this type may not be interpreted to indicate the presence of positively‐charged groups at the electrokinetic surfaces of intact living cells.
Malignant and transforming activity of rous sarcoma virus. I. Malignant effect of rous sarcoma virus
Authors: Obukh I. B. , Kryukova I. N. , Biryulina T. I. , Kuznetsova N. N.
Published: February 2007

Cultures of cells from embryos of Af, C3H‐Hp/2 and (CBAT6T6 × Af)F1 mice rapidly developed oncogenicity for syngeneic animals after exposure to RSV (Carr‐Zilber strain). The tumours of mice were virogenic and contained the group‐specific antigen of avian sarcoma‐leukosis complex. However, when the infected cells became transformed in morphology, they lost their oncogenicity for syngeneic animals.
Transformation of hamster cells in vivo and in vitro by an adenovirus 4‐SV40 hybrid
Authors: Easton John M. , Rabson Alan S. , Malmgren Richard A.
Published: February 2007

A preparation of adenovirus 4, containing infectious SV40 genetic material enclosed within adenovirus coats (Ad. 4‐SV40 hybrid), induced both transformation of newborn hamster kidney cells in vitro and tumors in neonatally inoculated hamsters. Injection of transformed cells into an irradiated weanling hamster also resulted in a tumor. Histologically, all of the tumors were fibrosarcomas similar to those induced in vivo by SV40 alone; no epithelial elements were noted. The three tumors were carried as serial transplants in hamsters; each of the three lines maintained a morphology slightly different from that of the other two. Sera from hamsters carrying the tumors contained antibodies to T antigens induced in cell cultures of African green monkey kidney by Ad. 4 and Ad. 7, but not by Ad. 12. This confirmed work by others, working with Ad. l‐SV40 and Ad. 2‐SV40 hybrid viruses, who found that genetic material from nononcogenic adenoviruses can be introduced into tumors and transformed cells by these hybrids. The cross‐reaction with cells infected with Ad. 7 provides additional evidence for a relationship between Ad. 4 and the B subgroup of oncogenic adenoviruses.
Characteristics of a tumor cell line and virus derived from hamster tumors induced by rauscher leukemia virus‐transformed hamster embryo cells
Authors: Rhim Johng Sik , Huebner R. J. , Ting R. C. , Wivel N. , Vass W.
Published: February 2007

A transplantable hamster tumor (RHT‐1) induced by Rauscher leukemia‐virus‐transformed hamster embryo cells was established in tissue culture, and its characteristics were studied. The tumor cell line also contained group‐specific complement‐fixing antigen and continuously released infectious virus. Electron microscope observation showed that this cell line contained C‐type particles. The virus derived from this line served as “helper virus” for a defective Moloney sarcoma virus (MSV) from a non‐infectious hamster tumor (HT‐1), and rescued infectious MSV by direct superinfection of the HT‐1 cells. This infectious MSV virus, which was identified as MSV (RLV) by the focus neutralization test, produced foci readily in both hamster embryo cells and NIH‐METC. Foci produced by this MSV (RLV) pseudotype in hamster embryo cells consisted largely of spindle‐shaped cells which stained vividly with acridine orange. Tumors were produced when cell‐free supernates of MSV (RLV)‐transformed hamster embryo cells, or the cells themselves, were injected into newborn mice. Tumors were also produced when transformed cells were injected into newborn hamsters.
Evidence for effects of heparin on cell surfaces influencing experimental metastases
Authors: Hagmar Björn , Norrby Klas
Published: February 2007

The effect of heparin on tumour cells and on intravenously induced metastases was studied in a syngeneic tumour‐host system, MCG1‐SS in CBA mice. In vitro heparin induced significant changes in the volumes of cells, but did not affect their aggregability or vitality. In vivo heparin did not affect the subcutaneous transplantability of tumour cells. Metastasis formation from intravenously injected cells was differently affected when heparin was given as intravenous pretreatment to animals, than when the same amount was given in the cell suspensions. Thus, pretreatment of animals with heparin affected pulmonary metastases only to a small degree, but gave an increased number of tumour takes in extrapulmonary organs. These changes were ascribed to systemic effects of heparin, above all on blood coagulability.

When given in the cell suspensions, heparin did not affect the number of extrapulmonary “takes”, but induced significant changes in pulmonary metastases. The average volume of such metastases became consistently smaller, while their number, if anything, rose. These effects were interpreted as being due to direct actions of heparin on the surfaces of tumour cells, probably related to its polyanion character. It was pointed out that in previous experiments with animals given large heparin doses, a direct cell effect might also prevail. Another polyanion, chondroitin sulphate, caused similar although less pronounced changes than heparin in vitro and in vivo. The polycation protamine had roughly opposite effects.
Modifications du Mëtabolisme Glucidique dans le Foie en Voie de Cancërisation par le Dimëthylaminoazobenzëne III. Recherches au Niveau de la Voie des Pentoses Phosphates
Authors: Jacob A.
Published: February 2007

Afin d'expliquer l'hypoglycëmie observëe chez les rats, au cours de la cancërisation du tissu hëpatique par le DAB, nous avons ëtudië la voie des pentoses phosphates. La quantitë de G6P entrant dans cette voie augmente durant le processus de cancërisation, par suite de l'augmentation de l'activitë G6PDH. La baisse d'activitë de la 6‐phosphogluconate dëhydrogënase dëtourne une partie du 6PG de la voie des pentoses phosphates, ce qui pourrait ëtre une des causes de l'hypoglycëmie. Il n'y a pas de modification de l'utilisation du R5P dans le tissu cancëreux.
Origin of neoplastic cells following prophylaxis of radiation‐induced mouse leukaemia
Authors: Ilbery P. L. T. , Barnes C. A.
Published: February 2007

The cytogenetic details of 57 primary radiation‐induced leukaemias, occurring after post‐radiation cell supplementation, are recorded. Over 90% showed the presence of abnormal classes and clones as defined. The incidence of leukaemia (about 70%) following the leukaemogenic schedule of irradiation was lowered by grafts of bone marrow or foetal liver but not abolished. The incidence of leukaemia was also lowered by intravenously supplemented foetal thymus but by no other thymic or lymphoid post‐radiation treatment. Even massive lymphoid grafting after each fraction of radiation and lymph‐node grafting beneath the renal capsule were ineffective. All the cases of leukaemia which did occur, with one possible exception, were in irradiated cells as shown by cytogenetic examination after grafting with cells suitably labelled chromosomally. The finding is in contrast to the frequent occurrence of neoplasia in cell lines from unirradiated thymic grafts after thymectomy and the same fractionated radiation schedule. Although the thymus is necessary for the supervention of this type of radiation‐induced leukaemia, it is not necessary for it to have received irradiation. Thymic cells in association with irradiated bone‐marrow cells colonizing this organ become neoplastic but non‐irradiated bone‐marrow cells colonizing an irradiated thymus are not rendered neoplastic and indeed have an inhibitory effect on the incidence of leukaemia. In four out of 28 (C57BL × CBA.T6T6)F1 leukaemias abnormal chromosomes not distinguishable from the marker were seen drawing attention, together with presumed loss of the marker in another leukaemia, to the frequency of non‐disjunction for this chromosome.
The distribution of the mouse mammary tumor agent and its antigenicity in milk
Authors: Miroff George , Lamberson Harold V.
Published: February 2007

Inbred mice with a propensity for mammary tumor development contain the mammary tumor agent and a specific soluble antigen in their milk. These were found in approximately equal proportions in both the supernatant and the pellet after ultracentrifugation. Over 90% of the agent and the highest antigen titer were located in a density range of 1.06–1.075 in ficoll density gradients. The low tumorigenic potential and the antigenicity of the B particle band (p = 1.12) remained with the particles after removal of proteinaceous contaminant by gel filtration. The immunogen from the upper portion (p = 1.06–1.075) of ficoll gradients appears to aggregate when concentrated and eluted from gel filtration columns. The tumorigenic material isolated from ECTEOLA and carboxymethylcellulose chromatographic columns does not show a high positive correlation with the distribution of the virus‐like B particles, which was consistent with the finding that the agent was concentrated in a narrow region with an average density of 1.28 in cesium chloride density gradients. The antigen associated with B particles and the lower molecular weight active component are immunologically identical.
Colony inhibition studies on blocking and non‐blocking serum effects on cellular immunity to moloney sarcomas
Authors: Hellström Ingegerd , Hellström Karl Erik
Published: February 2007

Moloney‐virus‐induced sarcomas, originating in BALB/c and A/Sn mice, were studied with the colony inhibition (CI) assay. Mice inoculated with the virus as adults developed tumors which spontaneously regressed (regressors) while mice inoculated with the same virus dose at an age of 21 days or less died from progressively growing tumors (progressors).

Serum from progressors blocked the colony inhibitory effect of lymph‐node cells (LNC) from the regressors. Serum from mice inoculated with the virus as adults had a similar blocking effect as long as the mice carried progressively growing tumors, but it did not block the LNC effect when harvested at the onset of regression or after its completion. When regressor sera were mixed with progressor sera the blocking effect of the latter decreased.
Studies on the rescue of a defective msv genome using leukemogenic viruses from different sources
Authors: Ting R. C. , Law L. W.
Published: February 2007

In vivo rescue of a defective MSV genome from isolated cells of the rat neoplasm MSB‐1 was achieved by simple and direct methods: (1) by mixing of tissue‐culture‐grown MSB‐1 cells with tissue extracts or with leukemogenic virus preparations prior to intramuscular inoculations into neonatal mice; and (2) by direct inoculations of these cells into neonatal or older mice previously infected with leukemogenic viruses or infected with vertically transmitted virus. Serial in vivo transfers of the rescued pseudotype viruses MSV (MLV) and MSV(RLV) were accomplished with ease but difficulty was experienced with those pseudotype viruses rescued with leukemogenic viruses of the Gross type, MSV (GLV) from C58, C3Hf/Fg and SJL strain leukemic mice; MSV (RadLV) rescued through the use of extracts from X‐ray‐induced leukemias of C57BL/Ka mice behaved in a similar manner to the MSV(GLV) pseudotype viruses. When tumor induction occurred, the lesions were of similar morphology no matter what the pseudotype virus inoculated and were classified as “atypical”; granulomas.
Immunodiffusion studies of eb virus (herpes‐type virus)‐infected and ‐ uninfected hemic cell lines
Authors: Stevens David A. , Pry Thomas W. , Blackham Elizabeth A. , Manaker Robert A.
Published: February 2007

Immunodiffusion testing of cellular antigen extracts from herpes‐type virus (HTV, EBV)‐infected and ‐uninfected cell cultures is described. The techniques, as used previously in seroepidemiologic studies, are known to be sensitive and comparable to other immunological methods for testing EBV antigen‐antibody reactions. They also appear to be virus‐specific, but possess the unique advantages of immunodiffusion resolution. Antigen preparations from four EBV‐infected cell lines, derived from different tissues, different diseases and different continents, demonstrated three identical antigenic components with selected reactive sera, and a fifth contained at least one of these. These cell lines also demonstrate the greatest number of virus‐infected cells by immunofluorescence or electron microscopy. Preparations from nine other less infected or uninfected cell lines and eight primary tissue specimens did not react in immunodiffusion or, in at least two instances, contained different antigenic components than the previous cell lines. The latter observation suggests there are other precipitating antibody‐antigen systems in these cell lines. Other information concerning the properties of the reactive components of the preparations is presented. By these immunodiffusion methods, herpes‐type viruses isolated from different sources appear to be immunologically identical.
The viability and capacity for further division, following tripolar mitosis, of cells of a murine ascites carcinoma in vitro
Authors: Roberts D. C. , Cole Glynda E.
Published: February 2007

This paper records the viability and capacity for further mitosis in vitro of cells of an ascites subline of a naturally‐occurring murine epithelioma following their rare tripolar mitosis. Under the conditions of these experiments it was found that the cells resulting from tripolar mitosis could be uninuclear cells only, one uninuclear and one binuclear cell, or a single trinuclear cell depending upon the degree of success of cytoplasmic cleavage. When uninuclear daughters only were formed, they were not seen to divide further. When one uninuclear and one binuclear cell were formed, the uninuclear daughter was seen to divide further, apparently normally, up to a maximum of six further cell generations, while the binuclear cell could form two uninuclear cells at its next mitosis which were themselves seen to divide, apparently normally, for up to two further cell generations.

In addition, cells underwent complex sequences of variance involving bipolar and tripolar mitosis, the resulting cells of which were usually viable and might, in some cases, be seen to undergo further, apparently normal, mitosis. It is proposed that these mechanisms lead to viable heteroploid cells in a tumour‐cell population, and the relevance of these findings to the initiation of new stem cell lines is briefly discussed.
Bladder tumours and smoking
Authors: Anthony Honor M. , Thomas Gretta M.
Published: February 2007

The smoking habits of 381 male bladder tumour patients, 412 lung cancer patients and 275 surgical controls were compared. The association between current cigarette smoking and lung cancer was demonstrated but no clear association was shown between smoking and bladder cancer. The data are compatible with a weak relationship with substantial current cigarette smoking only, as in other studies, but could also be consistent with a stronger association masked by some other carcinogenic hazard. The data strongly suggest that the prognosis of the original bladder tumour or of recurrences was worse in those who continued to smoke than in non‐ and ex‐smokers.
Report of the working group on inhalation carcinogenesis, with special reference to cigarette smoke
Authors: Tannenbaum A.
Published: February 2007

The working party served to bring together for 3 days a number of people who were either actually engaged in the field of inhalation carcinogenesis or in pertinent related areas. Sufficient time was available for an open, frank discussion of the problems and pitfalls, the design of equipment for exposing animals to fresh cigarette smoke, and the suitability of various species for bioassay of cigarette smoke.
Alkylation of the dna of sensitive and resistant tumours by a nitrogen mustard derivative
Authors: Connors T. A. , Double J. A.
Published: February 2007

The concentration of 3H‐aniline mustard in two tumour lines has been measured and the level of binding of the drug to DNA followed for 48 hours after intraperitoneal injection. Although the two tumour lines differ a hundred‐fold in their sensitivity to this alkylating agent, no good correlation was found between the levels of alkylation of DNA or the rate of removal of drug from DNA and the sensitivity of the tumour to the agent, although 24 hours after administration of the agent the label was removed from the DNA of the resistant tumour at an unexpectedly high rate.
A study of nitrosamines and S‐carboxyl derivatives of cysteine as lung carcinogens in adult SWR mice
Authors: Mirvish S. S. , Kaufman Louise
Published: February 2007

Four nitrosamines were tested as lung carcinogens in SWR mice, and the results were compared with those obtained for urethan. In general, two doses were injected intraperitoneally into adult mice. Dimethylnitrosamine (DMN) and diethylnitrosamine (DEN) were about as highly active as urethan at the doses used. Although the molar dose for DMN was one‐seventh of that for DEN, DMN produced the greater effect. In contrast, for liver carcinogenesis in the rat, DEN is known to be at least as potent on a molar basis as DMN. Nitrosopiperidine and di ‐n‐butylnitrosamine showed border‐line activities.

Similar tests were performed on the urethan metabolite N‐acetyl‐S‐carbethoxy‐cysteine (which was prepared crystalline for the first time) and the related compounds, S‐carbamylcysteine and S‐carbobenzyloxycysteine. Negative results were obtained, indicating that the S‐carbethoxy compound is not a proximal carcinogenic metabolite of urethan.