bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth and antigenic properties of a biopsy‐derived Burkitt's lymphoma in thymus‐less (nude) mice
Authors: Povlsen C. O. , Fialkow P. J. , Klein Eva , Klein G. , Rygaard J. , Wiener F.
Published: February 2007

A Burkitt's lymphoma was transferred to the congenitally athymic mouse mutant nude with biopsy material from a 7‐year‐old Kenyan girl. The tumor grows locally at the site of inoculation with no distant metastases. The established tumor has been maintained for six passages so far with preservation of histological and cytological appearance. The mouse‐passaged tumor has a normal human diploid female chromosome complement. Isozyme studies have shown tumor to be of the same glucose‐6‐phosphatedehydrogenase (G‐6‐PD) and phosphoglucomutase1 phenotype (B and 2‐1 respectively) as tumor biopsy from the patient. The mouse‐passaged line maintained surface IgM, similarly to the original tumor and the derived tissue culture line, but lost the IgG coating characteristic for the original tumor but absent from two subsequent biopsies and from the derived tissue culture line. This is in line with previous observations indicating that surface‐associated IgG on Burkitt biopsies is due to coating from the outside, whereas surface‐associated IgM is a cell marker. Whereas the biopsy cells of the patient were positive for EBV‐associated membrane antigen (MA), but not for early antigen (EA) and viral capsid antigen (VCA), the mouse‐passaged line was positive for all three. This suggests that the restrictive influence of the human host on the production of EA and VCA in the Burkitt tumor is raised in the mouse host. The serum of the tumor‐bearing nude mice contained anti‐human antibodies, but no detectable EBV (anti‐MA, EA and VCA)‐antibodies.
Cell locomotion and contact inhibition of normal and neoplastic rat cells
Authors: Veselý Pavel , Weiss Robin A.
Published: February 2007

The morphology, locomotion and contact inhibition of locomotion of normal and neoplastic rat cells were studied in relation to oncogenicity. Embryonic fibroblasts (LWF) and a spontaneously neoplastic variant (LW13) were both fibroblastic in appearance, with a monolayered arrangement of cells at moderate densities. A variant transformed by Rous sarcoma virus (RsK4) was epithelioid and was also well monolayered. Scanning electron microscopy revealed a smooth dorsal surface on LWF cells, microvilli on the dorsal surface of LW13 cells and numerous microvilli, blebs and ruffles over the entire surface of RsK4 cells. LWF cells and LW13 cells moved with broad fan‐shaped lamellae on which lamellipodia (ruffles) arose at the leading edge. These cells showed polarized locomotion and migrated rapidly into wounds made in confluent cultures. RsK4 cells neither possessed large, fan‐shaped lamellae nor showed polarized movement. They did not invade wounds efficiently. After treatment with colcemid LWF and LW13 cells resembled RsK4 cells more closely and lost polarity of movement. On analysis of cell collisions by time‐lapse cinemicrography, the three cell types showed pronounced homotypic contact inhibition of cell locomotion, as judged by cessation of forward displacement. LWF and LW13 cells exhibited paralysis of ruffling, contraction of the leading edge, cell to cell adhesion and inhibition of pinocytosis typical of contact inhibition between fibroblasts. Paralysis and contraction were not evident in RsK4 cell collisions. Colcemid treatment did not prevent the initiation of contact inhibition but reduced the lasting paralysis of LWF and LW13 cells. In collisions between tumour cells and normal cells, cell locomotion and membrane ruffling were inhibited in the normal cells but not in the tumour cells. Such non‐reciprocal contact inhibition resulted in apparent monolayering in mixed cultures. The loss of contact inhibitory responses of neoplastic cells to normal cells appears to be more closely related to oncogenicity than are homotypic contact inhibition and cellular morphology. The contact inhibitory stimuli of certain neoplastic cells differ from those of normal fibroblasts, and may be preserved by fixation with glutaraldehyde.
Synthesis of murine leukemia virus in cell culture
Authors: Okano Hiromitsu , Rich Marvin A. , Johns Lewis , Rich Ruth
Published: February 2007

Using high resolution, electron microscopic autoradiography, the times for macromolecular synthesis and assembly of a murine leukemia virus were determined. The time between completion of viral, RNA and protein synthesis and the appearance of morphologically complete virions did not exceed 30 min. The sequence of cellular labeling following exposure to 3H‐uridine was: nucleolar; nuclear; cytoplasmic. Labelling kinetics for viral RNA paralleled that for cytoplasmic RNA and coincided with a decrease in grain counts over nucleolar areas. Comparison of labelling kinetics for type‐A and ‐C virions supports the idea the type‐A virions are precursors for type‐C.
Cytogenetic analysis of human acute and chronic myeloid leukemic cells cloned in agar culture
Authors: Moore Malcolm A. S. , Metcalf Donald
Published: February 2007

Karyotypic analysis was performed on agar cultures of blood or bone marrow from 12 patients with acute or chronic myeloid or myelomonocytic leukemia in whom karyotypic markers were present. The granulocytic colonies and clusters which developed on culture were shown to be derived from representative cells of the leukemic population. In two patients with acute leukemia in remission, normal colonies with a normal karyotype were grown from marrow cells but in two patients with chronic myeloid leukemia in remission the Ph1 abnormality persisted in colony cells. The agar culture technique appears to be ideal for following the emergence and disappearance of leukemic and normal granulopoietic populations in patients with these types of leukemia.
Immunodepression as a factor during 3‐methylcholanthrene carcinogenesis and subsequent tumour growth in mice
Authors: Rees Jennifer A. , Symes M. O.
Published: February 2007

CBA/H‐T6 mice received a dose of 3 or 6 mg 3‐methylcholanthrene on day 0 and their spleen cell IgM antibody response to sheep red blood cells was found to be significantly depressed 23 days thereafter. However, at this time, there was no reduction in the ability of spleen cells from these mice to induce a graft‐versus‐host reaction in (A × T6)F1 hybrid animals. On day 68 after 3‐MC injection, six animals had developed tumours while six were still in the latent period. There was no difference in the capacity of spleen cells from these two groups of animals to induce a GvH reaction in F1 hybrids. Three 3‐MC induced sarcomata were serially passaged in isogenic hosts. The growth rates of these tumours increased and the regional lymph nodes and spleens became progressively more hypoplastic in successive hosts. However, there was again no decline in immunocompetence of spleen cells as judged by the induction of a GvH reaction in F1 hybrids. It is therefore suggested that the increase in tumour growth rate reflected a change in the tumour rather than increasing immunodepression of successive hosts.
Mechanism of resistance of yoshida sarcoma to nitrogen mustard. III. Mechanism of supressed transport of nitrogen mustard
Authors: Inaba Makoto
Published: February 2007

Mechanism of decreased transport of nitrogen mustard (HN2) in HN2‐resistant Yoshida sarcoma cells was investigated. HN2 uptake by Yoshida sarcoma cells proved to be temperature sensitive, saturable, affected by metabolic inhibitors, and also repressed competitively by choline chloride. In resistant cells, the uptake of choline was markedly depressed. Kinetics of choline transport in resistant cells was comparatively examined, and decreased Vmax and increased Km were observed in some resistant sublines. Accordingly, decrease in choline uptake may be due to decreased activity of choline transport‐carrier, both qualitatively and quantitatively. Decreased HN2 uptake by resistant cells seemed to be produced by the same mechanism.
Some international differences in histology and survival in breast cancer
Authors: Morrison Alan S. , Black Maurice M. , Lowe C. Ronald , Macmahon Brian , Yuasa Shu
Published: February 2007

Survival rates for patients with breast cancer have been reported to be higher in Japan than in the United States. It has also been reported that histologic features associated with more favorable survival are more frequent in Tokyo than in the United States. In this report data are presented on the question of whether differences in breast cancer histology could account for the differences in survival rate between Tokyo and two western areas–Boston, USA, and Glamorgan, Wales. Intraductal carcinoma was found to be most frequent in Tokyo and least frequent in Boston, but survival differences between the two cities were found when non‐invasive cases were excluded. Low (relatively malignant) nuclear grade was observed most often in Glamorgan; there was little difference in frequency of this characteristic between Boston and Tokyo. Since nuclear‐grade specific survival ratios were highest in Tokyo, this histologic feature also does not account for the better survival experience of Japanese patients. Tumors of medullary histologic type and those with high degrees of lymphoid infiltration were most frequent in Japan and least frequent in Boston. However, the relationships of histologic type and lymphoid infiltrate to survival were not consistent in the three areas, and the higher survival ratio of the Japanese patients could not be related to these characteristics.
Race and place in the etiology of nasopharyngeal cancer: A study based on California death certificates
Authors: Buell Philip
Published: February 2007

A review of the California death certificates coded to nasopharyngeal cancer as cause of death during 1955–64 revealed that five of 273 white male decedents were born in the Philippine Islands or China, areas where the disease is known to be endemic. The expected number, based on certificates for other cancer deaths, was much less than one. From the death certificate entries for name and birthplace of parents of decedents it was apparent that the five decedents were of Caucasian stock without Mongoloid admixture. This is the first indication that there is a high risk of nasopharyngeal cancer not only for the Mongoloid peoples who are indigenous to Southeast Asia, but also for Whites born in the area.
Specific inhibition of sarcoma‐specific cellular immunity by sera from patients with growing sarcomas
Authors: Cohen Alfred M. , Ketcham Alfred S. , Morton Donald L.
Published: February 2007

Sarcoma‐specific cellular cytotoxicity was inhibited by sera from 14/16 patients with growing sarcomas, in comparison to only 1/8 patients with growing carcinomas and 4/14 sarcoma‐free patients. Of 11 completely inhibitory sarcoma sera, only two inhibited lung carcinoma‐specific cellular cytotoxicity. The presence of serum inhibition of sarcoma‐specific cellular cytotoxicity antedated the development of metastatic sarcoma.
Sequential studies on cell‐mediated tumor immunity and blocking serum activity in ten patients with malignant melanoma
Authors: Hellström I. , Warner G. A. , Hellström K. E. , Sjögren H. O.
Published: February 2007

Ten human patients with malignant melanoma were followed with respect to two in vitro parameters of tumor immunity, the ability of the patients' blood lymphocytes to destroy cultivated melanoma cells, and the ability of the patients' sera to block such destruction, and with respect to changes in the clinical status, such as increases or decreases in detectable tumor mass. Allogeneic and (to a much lesser extent) autochthonous melanoma cells were used as targets. The degree of lymphocyte‐mediated tumor immunity was higher in patients with little or no residual tumor than in patients with large tumor loads, although the latter patients were also found to be reactive. Sera from patients with clinically detectable melanoma could block the cytotoxic lymphocyte effect, as could sera from patients who developed melanoma shortly after the serum harvest. Disappearance of blocking serum activity was seen to accompany clinical improvement. Sera from some patients without clinically detectable tumor could potentiate the cytotoxic effect of lymphocytes from melanoma patients. The findings support the view that cell‐mediated tumor immunity and blocking serum activity, as studied in vitro, are important correlates of the patients' immunological defense against their tumors in vivo, and they suggest that monitoring of these parameters may be prognostically useful. They also suggest that procedures capable of improving cell‐mediated tumor immunity without increasing blocking serum activity may be therapeutically beneficial.
Multiple tumors in the pericardial cavity of an australian rock oyster, crassostrea commercialis (iredale and roughley)
Authors: Dinamani P. , Wolf Peter H.
Published: February 2007

A pedunculated tumor within the pericardial cavity of a Sydney rock oyster (Crassostrea commercialis) was discovered during a routine dissection. The tumor measured 5 × 4.8 × 4.5 mm, was lobulated and was attached to the dorsal parietal pericardium over the ventricle, close to the anterior aorta. Associated with it were three smaller nodular lesions, also on the parietal pericardium. All four masses were composed chiefly of vesicular connective tissue (Leydig cells of oysters) within which mild inflammatory cell infiltration and fibrosis were present. The mesothelium overlying or enveloping the tumors was moderately hyperplastic. These apparently multicentric lesions present a problem in differential diagnosis among (1) slow‐growing, multi‐centric, benign neoplasms of Leydig cell origin, (2) developmental anomaly, including hamartoma, (3) hyperplasia secondary to inflammation and repair. The authors consider the first of these possibilities to be the most acceptable. The tumors in this specimen appear to belong in a group with three similar ones previously recorded in the literature. Their precise nature in relation to neoplastic processes remains unsettled.
Ultrastructural distribution of concanavalin‐a receptors on hamster embryo and adenovirus tumour cell cultures
Authors: Rowlatt C. , Wicker R. , Bernhard W.
Published: February 2007

An electron microscope cytochemical reaction, based on the specificity of concanavalin A for certain sugar residues, was used to study the surface coat of cells in cultures of an Adenovirus 12 hamster tumour cell line (TAd12 XIV), of cell strains from other hamster tumours induced by simian Adenovirus 7 (SA7) and of secondary cultures of normal hamster embryo cells. When the reaction was performed on living cells, in situ in the bottles in which they had been grown, a uniform surface coat of positive material was found on the normal embryo cells. The tumour cells were also positive, but the reaction product had a tendency to be more patchily distributed over the surface. This discontinuity of the labelling was particularly pronounced in the strain TAd12 XIV, but was less visible in the highly malignant strains SA7. When the reaction was performed on cultures previously fixed with formaldehyde, no difference was found between the three types of cell cultures. Simple stereological analysis confirmed these findings. It was concluded that loss of material occurred differentially between the different types of culture during the stages of the reaction before fixation. The possibilities of this loss being due to physico‐chemical differences in the cell surface material or to underlying metabolic changes are discussed.
Relationship between the sensitivity of EBV‐carrying lymphoblastoid lines to superinfection and the inducibility of the resident viral genome
Authors: Klein George , Dombos Laszlo
Published: February 2007

Human, EBV‐carrying lymphoblastoid lines show wide differences in their sensitivity to superinfection with EBV concentrates and also in their sensitivity to the activation of the resident viral genome by BUDR and IUDR. A significant correlation was found between sensitivity to superinfection and activation in 23 virus‐receptor‐positive lines. In 10 receptor‐negative lines, there was no such correlation: they were resistant to superinfection since they could not adsorb the virus, but differed widely in their activatability. The findings suggest that the intracellular restrictive mechanism that limits superinfection in the receptor‐positive, resistant lines, can also restrict the function of the activated genome, derived from within. Since some of the lines that were resistant to both superinfection and activation were spontaneous producers, however, it appears that the same mechanism does not necessarily affect the “spontaneous” function of the resident genome.
Histologic characteristics of breast cancer in Boston and Tokyo
Authors: Macmahon Brian , Morrison Alan S. , Ackerman Lauren V. , Lattes Raffaele , Taylor Herbert B. , Yuasa Shu
Published: February 2007

Histologic slides from representative series of breast cancer patients in Boston, where the incidence rate of breast cancer is high, and in Tokyo, where the incidence rate is low, were reviewed by pathologists who did not know the city of origin of the material. Intraductal, medullary and colloid histologic types were relatively more frequent in Tokyo. Also more frequent in Tokyo were tumors with circumscribed margins and a high degree of cellular reaction. Tumors of small‐cell or invasive ductal histologic type and tumors with a high degree of fibrosis were more frequent in Boston than in Tokyo.
Temperature‐dependent alterations in 2‐deoxyglucose uptake in rat cells transformed by a cold‐sensitive murine sarcoma virus mutant
Authors: May J. T. , Somers K. D. , Kit Saul
Published: February 2007

Cells transformed by Moloney sarcoma virus (MSV) take up 2‐deoxyglucose at a faster rate at 39° C than uninfected or Moloney leukemia virus (MoLV)—infected normal rat kidney (NRK) cells. In a sarcoma‐virus‐transformed cell line, NRK (MSV‐lb), whose transformed phenotype is expressed at 39° C (permissive) but not at 33° C (non‐permissive), the stimulation of 2‐deoxyglucose uptake at 39° C is temperature dependent; the increase is observed when cells are grown at 39° C but not at 33 C. When these cells were shifted from the non‐permissive to the permissive temperature, the uptake increased from a rate near that of uninfected cells to a rate half that of NRK cells infected with Moloney sarcoma‐leukemia complex (MSV‐MoLV). The reverse change occurred when the cells were shifted from the permissive to the non‐permissive temperature. Thus in a sarcoma virus‐infected rat cell line where the maintenance of the transformed state is dependent on a cold‐sensitive viral function, the uptake of 2‐deoxyglucose is reduced in the cold‐sensitive cells and correlated with the expression of the transformed phenotype.
Cell‐mediated immune reaction against tumors induced by oncornaviruses. II. Nature of the effector cells in tumor‐cell cytolysis
Authors: Leclerc J. C. , Gomard E. , Plata F. , Levy J. P.
Published: February 2007

The nature of the effector cells detected by the chromium release test (CRT) has been studied in BALB/c and C57Bl/6 mice bearing murine sarcoma virus (MSV)‐induced tumors. Anti‐θ‐C3H immune sera completely inhibited the cytotoxic activity of lymphoid cells in the presence of complement; anti‐immunoglobulin sera failed to decrease this activity. No activation of normal non‐sensitized lymphoid cells in the presence of heat‐decomplemented sera from mice bearing MSV‐induced sarcomas could be obtained. Identical results have been found in allogeneic systems with major H‐2 histocompatibility antigens. It can be concluded that a thymus‐processed lymphoid cell sub‐population sharing the θ antigen is exclusively or very predominantly responsible for the immune cytolysis both in syngeneic tumor systems and in allogeneic transplantation systems.
Localization of alpha‐fetoprotein in transplantable murine teratocarcinomas
Authors: Engelhardt N. V. , Poltoranina V. S. , Yazova A. K.
Published: February 2007

Embryo‐specific serum component α‐fetoprotein (AFP) was localized by the indirect immunofluorescent technique on paraffin sections of transplantable teratocarcinoma of strain 129/SV‐S1 CP mice. AFP was found in several types of structures comprising an insignificant part of the total section area. Most frequent and bright AFP‐specific fluorescence occurred in the epithelium of endodermal origin lining cysts and tubules; in addition, AFP was found in sheets of cells, groups or individual cells of non‐identified origin and in squamous epithelium arranged in pearls. In cysts and granules isolated from the ascitic fluid, developing after an intraperitoneal injection of teratocarcinoma suspension, AFP was found in cells of the external layer, very similar to those of the visceral yolk sac, and in the embryotype mesenchyme inside the cysts. By analytical disc‐electrophoresis in polyacrylamide gel, cysts were found to contain albumin, AFP, transferrin and gamma‐globulin, the relative proportion of AFP being considerably higher than in the ascitic fluid as compared with the other proteins mentioned. It is suggested that AFP localization in teratocarcinomas corresponds to the sites of its synthesis in the embryo and that AFP synthesis is a specific function of certain forms of endodermal differentiation.
Common avian oncornavirus‐induced tumor antigens in different species as revealed by immuno‐ferritin techniques
Authors: Gelderblom Hans , Bauer Heinz
Published: February 2007

The application of avian RNA tumor virus (ATV)‐neutralizing chicken sera to ATV‐transformed mammalian cells followed by indirect immuno‐ferritin labelling revealed an ATV group‐specific cell membrane labelling in two mouse cell lines. The respective antigens seem to be cross‐antigenic to the tumor‐specific surface antigen (TSSA) demonstrated recently on ATV‐transformed chicken embryo cells. The common antigens do not represent ATV envelope antigenicities or any of the other characteristized virus structural components.
Persistence of rous sarcoma virus in transformed non‐permissive cells: Characteristics of virus induction following sendai virus‐mediated fusion with permissive cells
Authors: Vigier Philippe
Published: February 2007

Virus induction in heterokaryons formed by non‐permissive cells transformed by Rous sarcoma virus (RSV) and permissive chick embryo (CE) cells, in the presence of inactivated Sendai virus, was studied with a clone of hamster BHK21 fibroblasts transformed by Schmidt‐Ruppin strain RSV (clone RS2) and subclones derived from this clone. The main results have been the following: (1) The number of heterokaryons giving rise to foci of Rous cells (focus‐forming infective centers, or FFICs) in mixed cultures is proportional to the number of RS2 cells when the initial CE:RS2 cell ratio attains 30, and almost all heterokaryons are then formed from single RS2 cells. (2) Recovery of FFICs also depends on the dose of Sendai virus. (3) Following fusion of RS2 cells with cells from different chick embryos the recovery of FFICs varies in parallel with the number of foci produced by free virus in cultures of these embryos. (4) The latent period of virus induction from the time of cell fusion is about 24 h, and somewhat longer than that of viral replication in newly infected CE cells. The growth of induced virus is similar to that of virus produced after de novo infection. (5) Virus induction requires no DNA synthesis but is inhibited, reversibly, by treatment for a few hours with inhibitors of DNA‐dependent synthesis (actinomycin D) and protein synthesis (puromycin and cycloheximide). Hence, non‐permissiveness of RS2 cells may be due to a partial block of transcription of the viral replicative DNA (provirus) present in the cells, and induction in heterokaryons to switching from partial to full transcription and translation of the provirus. However, it is also possible that some function, or factor (s) of the CE cells is required for virus production in heterokaryons. (6) The study of a subclone of RS2 cells 100‐ to 1000‐fold less inducible than other subclones suggesting that, in this subclone, non‐permissiveness may be due to a permanent block of synthesis of all viral proteins, at the level of transcription of the provirus.
Inhibition of hepatoma‐immune lymph‐node cell cytotoxicity by tumour‐bearer serum, and solubilized hepatoma antigen
Authors: Baldwin R. W. , Price M. R. , Robins R. A.
Published: February 2007

Sera from rats bearing transplanted aminoazo‐dye‐induced hepatomas inhibited the cytotoxicity of lymph‐node cells from tumour‐immune rats for plated hepatoma cells, when the sera were incubated with the effector cells, rather than target cells. In contrast, sera from hepatoma‐immune rats, which have previously been shown to block lymphocyte cytotoxicity at the level of the target cell, failed to inhibit lymph‐node cell cytotoxicity when pre‐incubated with the effector cells. The possibility that antigenic determinants could be responsible for lymphocyte inhibition is supported by the demonstration that papain‐solubilized hepatoma‐specific antigen preparations inhibited lymph‐node cell cytotoxicity. The role of specific antibody, antigen and immune complexes in the interaction between cellular immunity and humoral factors during tumour growth is discussed.
In utero tumor induction by murine sarcoma virus (moloney) in the rat. II. Histological and ultrastructural characteristics
Authors: Sobis H. , Vandeputte M.
Published: February 2007

On histological examination the twelve MSV‐induced tumors in the uterus observed in our study proved to be of fetal origin. Ten of the 12 tumors had the histological and ultrastructural characteristics of a yolk‐sac tumor. The two other tumors examined had a different morphological structure. One was classified as a teratoma with embryonal carcinoma, the other as a carcinosarcoma. In the primary neoplasms virus particles were found. Their ultrastructure was similar to that of MSV. The histology and the electron microscopy results are discussed in relation to the morphogenesis and the occurrence of these tumors in rodents as well as in man.
Chromosomal control of malignancy in tumors from cells transformed by polyoma virus
Authors: Yamamoto Toshiyuki , Hayashi Makoto , Rabinowitz Zelig , Sachs Leo
Published: February 2007

The chromosome banding pattern has been analyzed in clones of male and female golden hamster cells independently transformed by polyoma virus and tumors derived from these cells. All the tumors showed either a loss of a piece of chromosome 53 or a gain of a piece or a whole chromosome of 56. An additional 72 chromosome in one line of transformed cells was lost in the tumors derived from this line. The results support our gene balance model of malignancy and indicate that genes of expression of malignancy in these cells were located on chromosome 56 and that genes for suppression of malignancy were located on a piece of chromosome 53 and on chromosome 72. All transformed lines and their tumors showed a loss of a piece of one or both × chromosomes in male and female cells, respectively. This loss of a piece of X chromosome was also found in non‐malignant revertants from polyoma‐transformed cells, so that this change in the X chromosome was not specific for malignant cells.
Correlation between various cell‐surface antigens induced by murine leukemia virus in the rat: Serological analysis
Authors: Kuzumaki Noboru , Takeichi Noritoshi , Sendo Fujiro , Kodama Takao , Kobayashi Hiroshi
Published: February 2007

Analysis based on the cytotoxicity test using antisera produced in rats indicated the presence of various cell‐surface antigens on the tumors in WKA/Mk rats induced or artificially infected by Friend, Rauscher or Gross viruses. Each line of the tumor was found to have a common antigen, namely group‐specific cell‐surface antigen. A Gross type‐specific and Friend and Rauscher type‐specific cell‐surface antigens were also detected, in keeping with the observations in the mouse system. In addition, the present experiments strongly suggested that a Friend strain‐specific antigen was detected only on the cell‐surface of the tumors in WKA/Mk rats induced or artificially infected by Friend virus. These results were in parallel with the data of previously reported transplantation studies.
Spontaneous and induced production of endogenous type‐C RNA virus from a clonal line of spontaneously transformed BALB/3T3
Authors: Lieber Michael M. , Todaro George J.
Published: February 2007

This report describes the different levels of expression of the endogenous type‐C viral genome in a spontaneously transformed, tumor‐producing clone (S16) derived from the BALB/3T3 murine cell line. Four of nine subclones of S16 were found to continuously release high titers of endogenous virus. Five other S16 subclones were virus‐nonproducers, but could be readily induced with 5′‐bromodeoxyuridine to release large quantities of the endogenous virus. The transformed subclones were much more readily induced to produce virus compared to the parent BALB/3T3 cell line. All virus‐producing subclones and one non‐virus‐producing subclone contained considerably larger quantites of the major group‐specific antigens of the mouse type‐C viruses than did the untransformed BALB/3T3 cells themselves. Kinetics of induction of type‐C virus was studied in two clones that did not spontaneously release virus. Extracellular viral polymerase could be detected within 24 h of BrdU application; it increased exponentially over a thousand‐fold range during the next 48 h, and then slowly declined. Thus, the probability of expression of the endogenous type‐C viral genome is increased in spontaneously transformed BALB/3T3 cells.
The development and specific suppression of concomitant immunity in two syngeneic tumour‐host systems
Authors: Chandradasa K. D.
Published: February 2007

Immunological resistance, concomitant with tumour growth, against two methyl‐cholanthrene‐induced murine sarcomas MC23 and MC6 differing widely in their immunogenicities, was studied in inbred C57BL and BALB/c strains of mice which are syngeneic with the respective tumours. It was found that, initially, immune responses to specific transplantation antigens resulted in a peak of antitumour resistance at 10–14 days after the implantation of the tumours. In the second phase of tumour growth a rapid decline of the resistance was observed. The peak at 10–14 days was followed by a greater than 50% loss of resistance to re‐inoculation with the tumour cells, 1 week later. Further decline of resistance in the MC6‐BALB/c system was followed by the acceptance and progressive growth of over‐threshold doses of tumour cells. A comparable observation could not be made in the immunogenically weaker MC23‐C57BL system where further loss of resistance was gradual. The above changes in the development and decline of anti‐tumour resistance were broadly correlated with the progress of the immunoblast reaction of the paracortical areas of regional lymph nodes. Changes of anti‐tumour resistance in the MC6‐BALB/c system were found to be associated with corresponding changes in the availability and/or effectiveness of specifically cytotoxic lymphoid cells, in the lymphoid organs, as well as a change in the quality of the serum factors from weakly inhibitory to mildly enhancing, in the tumour. Specifically cytotoxic lymphoid cells could not be demonstrated in the MC23‐C57BL system by the lymphocyte neutralization technique employed, possibly due to the involvement of in vivo blocking phenomena. Accordingly, sera of these mice proved to be tumour‐enhancing throughout the period of tumour growth. It is suggested that the progressive growth of the tumours is facilitated by the specific suppression of cell‐mediated immunity by the “efferent” as well as by the “afferent” mechanisms and is brought about by a factor or factors–possibly antibody and/or antigen‐antibody complexes–present in the serum of the tumour‐bearing mice.
Influence of cultivation, trypsinization and aggregation on the transplantability of melanoma B16 cells
Authors: Hagmar Björn , Norrby Klas
Published: February 2007

To elucidate the usefulness of tumour cells grown in vitro for transplantation studies, Melanoma B16 was grown in monolayer culture. Three types of suspensions were prepared from the cell cultures: two virtually monocellular suspensions, one produced by mechanical procedures and Versene (CV), the other with the addition of trypsinization (CTV); a third suspension containing cell aggregates (CVA) was produced by centrifuging a CV suspension. For comparison, a well‐dissociated suspension of solid tumor origin was prepared by a trypsin‐Versene procedure (STV). All suspensions were characterized with regard to dissociation grade, cell volumes and cellular electrophoretic mobility and were transplanted in graded cell doses subcutaneously, intraperitoneally and intravenously. While inoculum‐doses needed for progressive growth were lower IP than SC, the transplantabilities were similar in these sites for all suspensions, indicating similar viabilities and absence of major dilution errors. The growth patterns for IV infused cells exhibited significant differences between the suspensions. CV cells gave rise to lung tumours almost exclusively, while CVA animals, in addition to a large total lung tumour volume, had some extrapulmonary takes. CTV had the greatest number of extrapulmonary tumours, but in combination with small lung tumours, STV cell recipients were intermediate with respect to pulmonary as well as extrapulmonary tumours. These observations were collated with data regarding aggregation, cell volumes and electrophoretic mobility. It was concluded that (1) cultivated tumour cells can have similar transplantation characteristics to the tumour of origin; (2) such cells may be useful in tumour dissemination studies; (3) trypsinization as well as the presence of cell aggregates affects the growth pattern of IV infused tumour cells by yielding an increased extrapulmonary tumour crop.
Carcinoembryonic antigenic activity of tissue extracts: A quantitative study of malignant and benign neoplasms, cirrhotic liver, normal adult and fetal organs
Authors: Khoo S. K. , Warner N. L. , Lie J. T. , Mackay I. R.
Published: February 2007

A quantitative study of carcinoembryonic antigenic activity (CEA) in extracts of 44 tumors, 42 fetal and 36 non‐malignant adult tissues from various organs was made and the CEA content detected by microradioimmunoassay was related to the wet tissue weight. A variety of malignant neoplasms, including carcinomas, sarcoma and Hodgkin's disease, contained CEA (range 17 to 2727 ng); apart from gastrointestinal carcinomas which had the highest content of CEA (230–2727 ng/g) only carcinomas of the lung contained moderate amounts of CEA (63–950 ng/g). The amount of CEA in extracts of fetal and normal adult organs was mostly low or not detectable except in the gastrointestinal tract and pancreas where it ranged from 65 to 200 ng/g in the fetus, and 28 to 86 ng/g in the adult. Differences in mean content of CEA between normal and cirrhotic livers were not significant. Although our results indicated that CEA was present in varying amounts in a variety of tumors the identification of these reactive substances will require more precise physico‐chemical and antigenic characterization.
Transplacental and combined long‐term effect of DDT in five generations of a‐strain mice
Authors: Shabad L. M. , Kolesnichenko T. S. , Nikonova T. V.
Published: February 2007

A‐strain mice were given technical DDT in sunflower‐seed oil at daily dose levels of 50 ppm during their entire life span for F0 generation and of 10 ppm for F0‐F5 consecutive generations. Exposure to both levels of DDT resulted in a significant increase of lung adenomas in F0 generations: 36.66% by 50 ppm and 19.05% by 10 ppm of DDT. In F1‐F5 generations exposed to 10 ppm of DDT lung tumours appeared in F1 (15.38%), in F2 (24.00%), in F3 (46.34%), in F4 (43.24%) and in F5 (12.69%). In control A mice lung tumours were not detected at 6 months of age, but were observed at 12 months in 10.88% and altogether (between 6 and 12 months) in 7.28%. In F2, F3 and F4 treated generations the incidence of lung adenomas was significant as compared to the controls. No other tumours were observed in the treated animals. The data obtained in vivo are discussed and compared with previous observations made in vitro. DDT must be evaluated as a weak carcinogen.
Platelet—tumor‐cell interactions in mice. The role of platelets in the spread of malignant disease
Authors: Gasic Gabriel J. , Gasic Tatiana B. , Galanti Norbel , Johnson Thomas , Murphy Scott
Published: February 2007

Thrombocytopenia reduces the number of metastases produced by a wide variety of murine tumors. Studies aimed at investigating interactions between tumors and platelets reveal that many tumors aggregated platelets in vitro and/or produced thrombocytopenia in vivo. In some instances, tumor‐cell‐induced thrombocytopenia in vivo was accompanied by accumulation of platelets in the lung. Thrombocytopenia was most active against metastases produced by tumors with the capacity to aggregate platelets in vitro and/or in vivo but it was also effective against metastases produced by tumors lacking such a capacity. Further studies, aimed at increasing platelet aggregation in vivo, as when fibroblasts were added to the tumor inoculum, or decreasing the platelet response to aggregating agents, as when aspirin was administered to mice, strongly support the role of platelet aggregation and the platelet release reaction in metastasis. As expected, fibroblasts enhanced while aspirin decreased tumor spread, the latter being equally effective against both artificially induced and spontaneously‐occurring metastases. Formation of platelet aggregates not only enhances but also seems to change the distribution of metastases. Tumors with platelet aggregating capacities usually give lung metastases while those devoid of such a capacity may show metastases of widespread distribution. Research with 125IUDR‐labelled B16 melanoma cells indicates that thrombocytopenia does not affect the initial vascular arrest of tumor cells but seems to influence their subsequent retention by the lung.
Mechanisms of enhanced intrahepatic metastasis in surfactant‐treated hamsters; An electron microscopy study
Authors: Cotmore S. F. , Carter R. L.
Published: February 2007

A metastasizing lymphoma (ML) in hamsters, grafted into the subcutaneous tissues, gives rise to moderate numbers of nodular intrahepatic deposits; but if the animals are treated with the surfactant triton‐WR 1339 (four intraperitoneal injections, 1,000 mg/kg body weight) the liver is massively and diffusely involved with secondary tumour. The results of serial ultra‐structural studies now indicate some explanations for this finding. The major factor appears to be that triton‐WR inflicts mechanical damage on cells of the sinusoidal lining, primarily as a result of lysosomal lesions which distend and distort the cells; this substantially facilitates the egress of tumour cells from the circulation into the extrahepatic tissue. Two possible subsidiary mechanisms are also considered: (1) Extensive lysosomal damage seen in Küpffer cells and in free, intravascular macrophages may perhaps result in impaired phagocytic activity within the liver; (2) Drug‐induced lysosomal damage in hepatic parenchymal cells may favour the establishment of tumour cells lying in the extravascular space. Triton‐WR is reported to exert an antifibrinolytic effect but this is apparently irrelevant to the enhanced intrahepatic growth of ML; there is no evidence that fibrin plays any part in the metastatic spread of this tumour.
Established cell line of urinary bladder carcinoma (T24) containing tumour‐specific antigen
Authors: Bubeník J. , Barešová M. , Viklický V. , Jakoubková J. , Sainerová H. , Donner J.
Published: February 2007

A cell line derived from human urinary bladder carcinoma, designated T24, was established in vitro. The growth of T24 cells in tissue culture was characterized by a disorderly pattern of growth in one or more layers and by mixed epithelioid‐fibroblastoid morphology. The generation time of T24 cells was 19 h. The cells had a hypotetraploid stemline with marker chromosomes. The malignant character of the line was verified by inoculation of cell suspension into hamster cheek pouch. The presence of tumour‐specific antigen (TSA) in T24 cells was demonstrated by a micromodification of the cytotoxicity test with autochthonous leukocytes and serum from the donor of the tumour. The TSA was also well detectable by the reaction with allogeneic leukocytes from tumour‐bearing patients and persisted during a 30‐month culture period. The permanent presence of TSA in this carcinoma cell line suggests that the TSA is a genetically determined characteristic of T24 cells.
Anti‐tumor activity in human serum: Antibodies detecting blood‐group‐A‐like antigen on the surface of tumor cells in culture
Authors: Bloom Eda T. , Fahey John L. , Peterson Inga A. , Geering Gayla , Bernhard Michael , Trempe Germain
Published: February 2007

Sera from many patients with tumors showed demonstrable cytotoxic antibody activity against selected human tumor cells in culture. The antibody activity detected in the present study was not found to be specific for tumors, but was shown to be directed against an antigen that is serologically related to blood group A. Direct cytotoxicity and absorption analyses, blocking tests, and erythrocyte adherence tests confirmed this conclusion. Antibody activity was found, as expected, frequently in sera from patients with blood‐groups O and B phenotypes, and not in patients belonging to blood‐groups A or AB. In view of the ubiquitous occurrence of blood‐group antibodies, their possible role in some human tumor serological studies should not be ignored.
Cell‐mediated immunity to human oral leukoplakia demonstrated by the leukocyte migration test
Authors: Roed‐Petersen Bjarne , Roed‐Petersen Jytte , Bendixen Gunnar
Published: February 2007

Tissue extracts from 11 oral leukoplakias and from normal oral mucosa of the same patients were tested in the LMT against autologous leukocytes. Five patients showed inhibition of the migration with leukoplakial tissue and one showed inhibition with normal mucosa. The migration of leukocytes from matched controls was not influenced by the tissue extracts, which accordingly had no non‐specific toxicity. It is concluded that oral leukoplakia is associated with a state of tissue‐specific, cellular hypersensitivity against antigenic components of the leukoplakial tissue.
Cell‐mediated and humoral immune reactions to human tumours
Authors: Baldwin R. W. , Embleton M. J. , Jones J. S. P. , Langman M. J. S.
Published: February 2007

Peripheral lymphocytes from cancer patients were tested for immune reactivity against cultured target cells derived from carcinomas of colon, rectum, breast, kidney and lung, and a melanoma by microcytotoxicity in plastic plates. Lymphocytes from colon or rectum carcinoma patients were cytotoxic for allogeneic colon or rectum carcinoma cells in 61% of tests, and no difference in reactivity could be detected between pre‐ or post‐operative patients. Breast carcinoma patients' lymphocytes were cytotoxic for breast carcinoma cells in 50% of cases tested. Autochthonous lymphocytes were reactive against melanoma cells, but no lymphocyte cytotoxicity could be demonstrated on cells of a renal carcinoma or a lung carcinoma. None of the lymphocyte preparations tested reacted positively against cells of a tumour different from that of the lymphocyte donor, and none reacted against cells from normal colon. Complement‐dependent cytotoxic humoral antibody was regularly detected against breast carcinomas, but only one sample of colon carcinoma serum, from a post‐operative patient, was reactive against colon carcinoma cells. Sera from melanoma patients likewise were only reactive against melanoma cells in two post‐operative cases.
Immunological studies on a case of recurrent Burkitt's lymphoma during immune stimulant treatment
Authors: Gunven Peter , Klein George , Henle Werner , Henle Gertrude , Rocchi Giovanni , Hewetson John F. , Guerra Angel , Clifford Peter , Singh Surjit , Demissie Aberra , Svedmyr Arne
Published: February 2007

Antibodies against several EBV‐ and non‐EBV‐associated antigens were titrated in serial sera from a patient with Burkitt's lymphoma who was given immune stimulants during chemotherapeutically induced tumor regression. EBV‐associated membrane reactive antibodies gradually declined during BCG treatment 3–4 months prior to triple (pertussis‐diphtheria‐tetanus, PDT) vaccination, after which they rapidly increased simultaneously with the appearance of multiple recurrent tumors. Prior to vaccination, antibodies to the R component of the EBV‐induced early antigen complex became detectable and increased further before the recurrences became evident. Antibodies to EB viral capsid antigens and to the D component of the early antigen complex also increased starting after triple vaccination, whereas most other antibodies studied remained stable during the observation period. Possible interpretations of the serological changes are discussed.
Comparative effects of hypophysectomy, ergocornine and ergocornine‐reserpine treatments on rat mammary carcinoma
Authors: Welsch Clifford W. , Iturri Gloria , Meites J.
Published: February 2007

Sprague‐Dawley rats bearing DMBA‐induced mammary tumors were hypo‐physectomized or injected with ergocornine or with ergocornine plus reserpine. Each treatment caused a prompt and prolonged regression of the tumors. Hypophysectomy was shown to be more effective in promoting tumor regression than treatment with ergocornine alone. However, reserpine administered in combination with ergocornine produced mammary tumor regression not significantly different from that obtained after hypophysectomy. These results are believed to provide a basis for further studies with drugs or drug combinations that can influence hypothalamic and/or pituitary activity to promote mammary tumor regression, and thus serve as a possible alternative to endocrine ablative procedures.
Transformation of rat and mouse embryo cells by a new class of carcinogenic compounds isolated from particles in city air
Authors: Gordon R. J. , Bryan R. J. , Rhim J. S. , Demoise C. , Wolford R. G. , Freeman A. E. , Huebner R. J.
Published: February 2007

The customary benzene extraction of airborne particulate matter collected in Los Angeles has previously been shown to yield carcinogenic material. The residue from the benzene extraction contains substances soluble in methanol, some of which are organic. This methanol extract and a number of its component fractions have been tested in rodent cell culture systems developed as assay methods for screening carcinogens. In one system a high‐passage Fischer rat embryo cell line was used. In the other a low‐passage cell line derived from NIH Swiss albino mouse embryos and infected with AKR leukemia virus was used. In both systems the methanol extract showed cell transformation activity approaching that of 3‐methylcholanthrene. In the mouse cell system the activities of several fractions were also examined. The major inorganic component, ammonium nitrate, showed no activity. Neither the neutrals alone nor the recombined non‐neutral fractions separately showed any activity, although they were active together. The basic materials separated by ion exchange were also active. The methanol extract combined with the conventional benzene extract showed much lower activity than either extract alone.