bluuebunny/crossref_metadata_2025 huggingface dataset:
Differences in the surface mobility between normal and SV40‐, polyoma‐ and adenovirus‐transformed hamster cells
Authors: Huet Ch. , Bernhard W.
Published: February 2007

Living cultures of normal hamster cells, and of hamster cells transformed by SV40, polyoma, Adenovirus 12 and Simian Adenovirus 7, were labelled in situ by 63Ni‐Concanavalin A, as well as by Con A and WGA revealed cytochemically by peroxidase, and by negative colloidal iron. They were then incubated at 37°C in PBS for different periods of time, varying from 8 min to 4 h prior to fixation and processing for electron microscopy. Con A labelling allowed us to show differences in the surface movements between normal and virus‐transformed cell cultures: the transformed cell lines had a much greater membrane mobility since most of the Con A/peroxidase‐labelled material disappeared from the cell surface within 15 to 30 min, whereas in normal cells it took 30 to 60 min to obtain the same patterns. Measurements of radioactive Con A showed that most of the lectin penetrated into the cell, and that shedding of labelled cell coat material into the medium was minimal. With the negative colloidal iron, the available amino groups were labelled and the same difference in the surface movements was again observed. However, we were unable to show any difference between normal and transformed cells with the WGA‐peroxidase complex. Rapid penetration occurred in both cell types, but in both cases label also remained present at the surface.
Kinetics of uptake of 2‐deoxy‐d‐glucose and 2‐aminoisobutyric acid in chemically transformed cells
Authors: Kuroki Toshio , Yamakawa Shigeyo
Published: February 2007

Kinetics of 2‐deoxy‐D‐glucose and 2‐aminoisobutyric acid uptake in chemically transformed hamster embryo cells and BALB 3T3 cells were investigated. Maximum velocity of the glucose uptake in chemically transformed cells increased 1.5 to 2.8‐fold over controls in Vmax without a detectable change in apparent Km. In uptake of the amino acid there was a slight change in Vmax and unchanged Km with chemically transformed cells, as compared to untransformed cells. Hexokinase activity showed a slight change after chemical transformation.
Induction of mammary fibroadenomas in rats by adenovirus type 9
Authors: Ankerst J. , Jonsson N. , Kjellén L. , Norrby E. , Sjögren H. O.
Published: February 2007

After inoculation of adenovirus type 9 into newborn Wistar/Furth rats, seven out of seven females developed one or several mammary fibroadenomas within 14–25 weeks after virus inoculation. No tumours were observed in male rats inoculated with the same virus or in untreated controls. Neonatal inoculations of adenovirus type 5, produced on the same HeLa cells, gave negative results in both sexes. The results indicate that benign mammary tumours can be induced in rats by a virus and that mammary fibroadenomas are induced by adenovirus type 9, previously known to be capable of transforming cells in vitro but not of inducing tumours in vivo.
Aetiological factors in oesophageal cancer in Singapore Chinese
Authors: de Jong U. W. , Breslow N. , Goh Hong J. Ewe , Sridharan M. , Shanmugaratnam K.
Published: February 2007

Analysis of a hospital‐based case‐control study of oesophageal cancer among Singapore Chinese (composed of Cantonese, Hokkien, Teochew and other dialect groups) revealed the following statistically significant risk factors for both sexes: (I) belonging to either Hokkien or Teochew dialect groups; (2) the consumption of beverages at temperatures stated subjectively to be “burning hot” prior to illness; and (3) the smoking of Chinese cigarettes. Additional risk factors for males were birth in China and the consumption of Samsu (Chinese wine). Consumption of bread, potatoes and bananas was reported at significantly lower levels in male oesophagus cancer patients than in controls. Oesophageal cancer was less common in males who had attended school for more than 8 years. Multivariate analysis (examination of the joint influence of selected variables) confirmed the strong effects of dialect group and beverage temperature for both sexes. For females the smoking of Chinese cigarettes remained a risk factor, for males the consumption of Samsu. The smoking of westerntype cigarettes and the consumption of strong liquors were not significantly related for either sex. These findings suggest that oesophageal cancer is more likely to occur among “traditional” Chinese who maintain dietary patterns which include Samsu and the drinking of beverages at hot temperatures, but avoid the bland foodstuffs (bread, potatoes and bananas) not native to their culture. The greater risk in Teochew and Hokkien may be due in part to the consumption of a greater number of beverages at “burning hot” temperatures compared with Cantonese and other dialect groups. However, these differences are based on subjective impressions which need to be verified by actual measurements of the temperature of drinks consumed by members of these population groups.
Studies on the mechanisms of invasion in cancer. IV. A factor associated with release of neutral protease of tumor cell
Authors: Koono Masashi , Katsuya Hiroaki , Hayashi Hideo
Published: February 2007

A substance capable of releasing a certain neutral protease from rat ascites hepatoma cells was extracted from tumor tissues and partially purified. The substance, which was assumed to be a thermostable peptide, was characterized by prompt action and noncytotoxicity. Intradermal injection of the released neutral protease induced extravascular migration of circulating tumor cells and formation of metastases. No protease could be released from normal hepatic cells. These observations suggested that the released neutral protease might be involved in malignant invasion through production of postulated cancer‐cell‐chemotactic factor. Such a substance was, however, difficult to demonstrate in normal skin. Different factors associated with the release of another neutral protease and an alkaline protease were also found. However, these proteases did not provoke invasion of tumor cells after intradermal injection.
Alterations in macromolecular synthesis and cellular growth in mouse embryo fibroblasts infected with friend leukemia virus
Authors: Gabelman Norman , Scher William , Friend Charlotte
Published: February 2007

The rate of DNA synthesis in secondary mouse embryo fibroblast (MEF‐2) cultures was increased following infection with Friend leukemai virus (FLV) as compared to control cultures which were untreated or exposed to heat‐denatured virus. A peak was reached between 24 and 48 h after infection. Radioautographic studies revealed that the infected cultures had a higher percentage of cells which incorporated tritiated thymidine into their nuclei as compared to controls. This increase was apparently independent of the ability of the cells to divide, since it was also observed in infected stationary cultures. The rates of cellular RNA and protein synthesis did not appear to be affected by FLV infection. The time required for the cell population to double was one‐third shorter in FLV‐infected cultures as compared to controls. The shortening of the generation time was found to be due to a decrease in the time required for the cells to traverse the G1 and S phases of the cell cycle. In addition, after 72 h of growth, the infected cultures reached greater population densities than did either of the controls.
Characteristics of murine C‐type viruses. III. Antigenic conversion and focus induction
Authors: Grundner Gertrud , Fenyö Eva Maria , Klein Eva
Published: February 2007

Viruses produced by two Moloney lymphoma sublines (Y and Yr), and their hybrids with a mouse L cell subline (YL and YrL) were tested for antigenic conversion and focus induction on JLS‐V9 and D56 (S + L −) cells. Two infectivity patterns were encountered. Both indicator cell lines were converted antigenically by the Y and YT viruses, whereas only D56 cells, and not JLS‐V9 cells, were converted by the Yr and YrL viruses. When infection of D56 cells was scored by both antigenic conversion and focus induction, further variations in infectivity patterns were found. The viruses produced by the YAC‐A9 and YACIR‐A9 hybrid cells (YL and YrL) appeared to be similar to the viruses produced by each of the lymphoma parents.
Cytotoxicity of human rosette‐forming blood lymphocytes on cultivated human tumor cells
Authors: Wybran Joseph , Hellström Ingegerd , Hellström Karl Erik , Fudenberg H. Hugh
Published: February 2007

Human peripheral blood lymphocytes from seven cancer patients were separated into two fractions, one rich in lymphocytes which could spontaneously form rosettes with sheep erythrocytes (T‐cells) and another poor in rosette‐forming cells. These two fractions were then tested for cytotoxic activity on cultivated tumor cells of the same histological type as the tumors of the respective lymphocyte donors. It was shown that T‐cell rich fractions had a higher cytotoxic activity than did the T‐cell poor fractions from the same patients. The findings indicate that human T‐cells can be cytotoxic, in vitro, against cultivated cells carrying tumor‐associated antigens.
S‐tropic murine type‐C viruses: Frequency of isolation from continuous cell lines, leukemia virus preparations and normal spleens
Authors: Lieber Michael M. , Sherr Charles J. , Todaro George J.
Published: February 2007

A survey was undertaken to determine the prevalence of S‐tropic (xenotropic) murine type‐C viruses in continuous cell lines, leukemia virus preparations, and spleens of normal mice from various commonly used strains. Fifteen of 18 cell lines established from normal cells and transplantable tumors produced infectious type‐C viruses. For all cell lines examined, the viral isolates were either N‐, B‐, or NB‐tropic, while S‐tropic viruses were not detected. Two cell lines derived from normal tissues, however, had S‐tropic viruses which could be induced by treatment with 5‐bromodeoxyurdine, whereas cell lines derived from transplantable tumors were non‐inducible. Nine standard leukemia virus preparations likewise do not contain S‐tropic viruses. In contrast, S‐tropic viruses were recovered from spleens of normal weanling mice from six of 13 strains, indicating that the expression of S‐tropic virus is relatively common in disease‐free animals. The failure to find S‐tropic viruses in known preparations of leukemogenic murine type‐C viruses and their presence in tissues from normal animals suggest that S‐tropic viruses may play a normal physiologic role in mice.
In vitro cellular immunity to epstein‐barr virus in normal human subjects
Authors: Fimmel Peter J. , Lai Patrick K. , Keast David , Alpers Michael P. , Mackay‐Scollay Ewart M.
Published: February 2007

Leukocyte migration inhibition was employed to study cell‐mediated immunity (CMI) to Epstein‐Barr virus (EBV) in 29 normal subjects. Anti‐EBV capsid antibody titres in these subjects ranged from 0 to 1:160. Extracts of seven human lymphoblastoid cell lines carrying EBV were evaluated as the source of test antigen. Of these cell lines studied, only P3HR‐1 proved suitable as a source of EBV antigen for use in the test. Undiluted tissue‐culture supernatant fluids of the EBV‐carrying cell lines P3HR‐1 and SH‐T1 caused only weak or equivocal migration inhibition in normal subjects; others tested were without effect. Antigen controls consisted of extracts of the Raji cell line, which contains the EBV genome but produces no EBV antigen, and cultured human cells with no known association with EBV, all of which failed to induce migration inhibition. Cellular controls consisted of EBV sero‐negative adult leukocytes and foetal cord blood leukocytes which did not respond to P3HR‐1 extract, although two of the five cord sera contained anti‐EBV capsid antibody. The migration inhibition response was antigen‐dose‐dependent and was not affected by anti‐EBV antibody capable of neutralizing the infectivity of EBV. These results show that CMI to EBV is present in normal individuals who have antibody to EBV capsid antigen.
Detection in human melanoma cell lines of particles with some properties in common with RNA tumour viruses
Authors: Parsons P. G. , Goss Patricia , Pope J. H.
Published: February 2007

Six established lines of malignant melanoma cells produced particles having a buoyant density of 1.14 to 1.18 g/ml and containing RNA with a component of approximately 70S. Fractions containing these particles showed RNase‐sensitive DNA polymerase activity, and in simultaneous assays the DNA product was found to be associated with 70S RNA. Similar results were obtained in control studies with two known oncornaviruses (Rauscher and WM1‐B mouse leukaemia viruses), but not with particles from three normal human fibroblast strains. Filtration studies showed that the uridine‐labelled particles from four melanoma cell lines, as well as the materials from two melanoma lines active in the simultaneous assay, were largely retained by filters with an average pore diameter of 100–650 nm. In negative‐stained preparations of 1.14 to 1.18g/ml fractions from four melanoma lines, a small number of virus‐like particles about 125 nm in diameter were detected, as well as smaller amorphous material and minute ring‐like structures about 12–14 nm in diameter. The evidence strongly suggests the production by these cultured malignant melanoma cells of particles with properties closely resembling those of oncornaviruses. Although evidence was found of similar virus‐like particles in a malignant melanoma biopsy, their role in the aetiology of malignant melanoma remains unknown.
Polyamine metabolism in tumor, spleen and liver of tumor‐bearing rats
Authors: Marton Laurence J. , Heby Olle
Published: February 2007

A brain tumor, originally induced by weekly IV injections of N‐nitro‐somethylurea in CD Fisher rats and subsequently carried in serial subcultures, was inoculated SC in the flank of CD Fisher rats. The synthesis and concentrations of the polyamines were studied at various times after the beginning of tumor growth. Higher activities of ornithine decarboxylase, S‐adenosylmethionine decarboxylase and higher concentrations of putrescine, spermidine and spermine were observed in the periphery when compared to the center of the solid tumor, and correlated with a higher growth rate in the periphery of the tumor. In the serum of rats with advanced tumors the concentration of spermidine was higher than in the serum of normal rats. Furthermore, putrescine was detectable in the serum of tumor‐bearing rats but not in normal rats. The tumor, which grows in a well‐defined non‐invasive manner, caused increased concentrations of putrescine and spermidine in spleen, and of spermidine in liver, at the time of most rapid growth. The increased polyamine concentrations may denote increased proliferation in the spleen and liver and are presumably part of an immunological response of the host animal to the growing tumor.
Immune cytolysis of murine tumor cells mediated by xenogeneic “Immune” RNA
Authors: Kern David H. , Pilch Yosef H.
Published: February 2007

Using a quantitative assay for lymphocyte‐mediated cytotoxicity, it was shown that normal, non‐immune C3Hf/HeCr mouse spleen cells were converted to effector cells specifically cytotoxic to chemically induced C3H tumor cells by incubation in vitro with “immune” RNA extracted from the lymphoid organs of specifically immunized guineapigs. This response was specific for the tumor used to immunize the RNA donor. Cytotoxicity indices (CIs) at 0.30 to 0.54 were consistently obtained. Spleen cells incubated with RNA from guinea‐pigs immunized with a different tumor, or with normal C3H tissue, failed to lyse the target cells. These immune responses were abrogated when the “immune” RNA was treated with RNase prior to incubation with the spleen cells. However, pre‐treatment with DNase or pronase did not alter the activity of the “immune” RNA. “Immune” RNA to a second chemically induced C3H tumor mediated a cytotoxic response to that tumor (CI=0.45), but not to the first tumor. This clearly demonstrates that xenogeneic “immune” RNA mediates tumor‐specific immune cytolysis, in vitro.
An analysis of variables affecting the measurement of tumor immunity In vitro with 125I‐iododeoxyuridine‐labelled target cells. Studies of immunity to primary moloney sarcomas
Authors: Seeger Robert C. , Rayner Sylvia A. , Owen John J. T.
Published: February 2007

Variables affecting the measurement of immunity to adherent tumor cells in vitro have been analyzed using the immune response to primary Moloney sarcomas in BALB/c mice as a model system. IUdR, a gamma‐emitting isotope which is incorporated into the DNA of dividing tumor cells, was used to quantitate the number of adherent tumor cells in 0.2 ml cultures. Lymphoid cell‐mediated killing of tumor cells was measured by labelling tumor cells before they were cultured with effector cells (cytotoxicity test), and lymphoid cell‐mediated inhibition of tumor‐cell growth was measured by labelling those tumor cells surviving interactions with effector cells (cytostasis test). Addition of lymphoid cells to adherent tumor cells initiates complex interactions which have non‐specific (i.e., unrelated to recognition of tumor antigens) and specific (i.e., related to recognition of tumor antigens) effects on the survival and growth of tumor cells. The magnitude of these effects, as measured in the cytotoxicity or cytostasis tests, depends upon the number, kind, and state of activation and/or sensitization of effector cells and upon the number and susceptibility of tumor cells. Effector cells from control mice have only non‐specific effects whereas those from MSV‐immunized mice have both non‐specific and specific effects. Lymph‐node cells (LNC) from normal control mice non‐specifically kill IUdR labelled tumor cells in the cytotoxicity test, whereas killing and growth‐promoting influences are both present in the cytostasis test. Non‐specific cytotoxic effects also were mediated by LNC from MSV‐immunized mice, and these effects were of greater magnitude than those mediated by LNC from normal control mice. Our present and previous experiments suggest that non‐specific cytotoxicity of LNC is largely due to macrophages. In contrast, non‐specific promotion of tumor‐cell growth in the cytostasis test is apparently mediated by lymphocytes. Specific cytotoxicity or cytostasis was obtained only when non‐adherent LNC (NALNC) containing 99.8% lymphocytes and less than 0.2% macrophages were employed as effector cells. Although both cytotoxicity and cytostasis tests seem to give similar results, we conclude, for a number of reasons, that the cytotoxicity test is preferable for measuring cell‐mediated immune responses to adherent tumor cells. Our findings and conclusions should be generally applicable to studies of animal and human tumors.
Cell‐mediated and humoral immunity studies of murine and hamster sarcoma virus‐induced producer and non‐producer tumors in syngeneic animals
Authors: McCoy James L. , Ting Robert C. , McCoy Nancy T. , Reisher Joel I. , Chan Sue P. , Law Lloyd W.
Published: February 2007

Murine sarcoma virus (MSV)‐induced transformed tumor cells, which are releasers and non‐releasers of virus, were investigated by transplantation immunity and a variety of serological assays. Transplantation immunity demonstrated that tumor‐associated transplantation antigens could be detected on producer cells and were also apparent, but to a lesser degree, on non‐releaser cells of BALB/c mouse origin. Some lymphocyte microcytotoxicity tests employing hamster MSV tumors failed to detect any in vitro immunity. Studies employing immunofluorescence, complement fixation and virus focus neutralization tests demonstrated that Harvey‐MSV producer cells of hamster origin were strongly immunogenic in inducing antibody formation in syngeneic hamsters. By contrast, no antibody could usually be detected by these techniques following immunization with non‐producer Harvey‐MSV or immunization with either Moloney‐MSV non‐producer cells or those non‐producer cells that had been made releasers by treatment with IUDR in syngeneic hosts. The results suggest that humoral antibody, as detected by the techniques employed, is probably produced largely in response to infectious MSV contained by producer tumor cells and is not directed against new cell neoantigens, whereas transplantation immunity is probably, in part, a response to non‐virion neoantigens.
Incorporation de l'antigène tumoral de transplantation spécifique du SV40 (TSTA‐SV40) dans le virus de la stomatite vésiculleuse cultivé en cellules de hamster transformées par le SV40
Authors: Ansel S.
Published: February 2007

Highly purified and inactivated VSV (VSV/TSV‐5 C1.2) grown in SV40 transformed hamster cells, TSV‐5 C1.2, induces in hamster a transplantation immunity against host‐tumor cells. Immunization with VSV/TSV‐5 C1.2 gave more than a 10‐fold protection against TSV‐5 C1.2 tumor cells. The transplantation immunity confered by the immunization is specific for tumor cells which possess SV40‐TSTA. VSV/TSV‐5 C1.2 protects hamsters against another SV40‐transformed cell line, EHSVi‐C1.1. In contrast, immunization with VSV/EHB, a purified preparation of VSV grown in spontaneously transformed hamster cells, EHB, gave no protection to TSV‐5 C1.2 cell challenge. It was concluded that the presence of SV40‐TSTA activity in VSV/TSV‐5 C1.2 virions was due to incorporation of this tumor cell antigen in the viral envelope. The existence of cell antigens in VSV/TSV‐5 C1.2 and VSV/EHB preparations was also shown in vitro by Cr51 release assay. The anti‐VSV/TSV‐5 C1.2 rabbit serum reacted specifically with SV40‐transformed cells, TSV‐5 C1.2 and EHSVi‐C1.1.
Detection of antibodies against virally‐induced tumor‐associated antigens by mixed hemadsorption
Authors: Gatti Richard A. , Jonsson Jonas
Published: February 2007

Antigens were solubilized and attached to glass slides. The coated glass slides were then used to detect relevant antibodies by a mixed hemadsorption technique. These studies focused primarily on solubilizing the Epstein‐Barr virus‐associated antigens VCA, EA and MA. Well‐characterized, discordant sera from patients with Burkitt's lymphoma and nasopharyngeal carcinoma were then used to evaluate the antigenicity of slides coated with the solubilized antigenic extracts. Good correlations were observed between titers of these sera for VCA, EA and MA as determined by immunofluorescence methods and by mixed hemadsorption. Most antigenic extracts could be stored directly or as coated‐glass slides for many months with only moderate decreases in antigenicity. Antibodies to Epstein‐Barr‐associated nuclear antigen (EBNA) were not detectable in these studies.
Isolation of a myelogenous leukemia‐inducing virus from mice infected with the friend virus complex
Authors: McGarry M. P. , Steeves R. A. , Eckner R. J. , Mirand E. A. , Trudel P. J.
Published: February 2007

A myelogenous leukemia‐inducing virus (MyLV) has been isolated from a chloroleukemic C57Bl mouse, injected neonatally with the lymphatic leukemia virus (LLV)‐containing helper component of the Friend virus (FV) complex. MyLV, free of detectable spleen focus‐forming virus (SFFV), consistently induced only myelogenous leukemia in neonatally infected C57Bl, Ha/ICR, C3H and BALB/c mice, within 5 months (including chloroleukemias in C57Bl and Ha/ICR). The leukemia involved chiefly the spleen, liver, lymph nodes and bone marrow, and tumor cells could be recovered from the marrow to grow in the solid (subcutaneous) or ascites (intraperitoneal) form. MyLV preparations had ample helper activity for SFFV in restrictive hosts, and could be used to prepare a MyLV pseudotype of SFFV which was antigenically indistinguishable from native FV complex. MyLV could have arisen by selection of a pre‐existing variant in the LLV population, by a genetic interaction between LLV and the C57Bl chloroleukemic host cell, or could have arisen from the original host C57Bl mice as a result of activation following the infection with LLV.
Sensitivity of different target cells to the killing action of peripheral lymphocytes stimulated by autologous lymphoblastoid cell lines
Authors: Svedmyr Erik A. , Deinhardt Friedrich , Klein George
Published: February 2007

Peripheral lymphocytes obtained from two individuals with a previous history of infectious mononucleosis were exposed to mitomycin‐treated cells of the autologous lymphoblastoid cell line (LCL) established during the acute phase of the disease. This resulted in a stimulation of DNA synthesis, comparable to or even exceeding a one‐way MLC with allogeneic lymphocytes. The cytotoxic effect of the stimulated lymphocytes was tested by colony inhibition or 51Cr release, against a large LCL panel, including the autologous line and allogeneic lines from patients with Burkitt's lymphoma (BL), nasopharyngeal carcinoma (NPC), infectious mononucleosis (IM), leukemia, myeloma, or normal donors. While the majority of the lines were highly sensitive to the killing action, three were relatively resistant. The same pattern of sensitivity was obtained with effector cells stimulated by autologous LCL derived from IM or BL patients. The majority of the target LCLs had B‐cell characteristics and carried the EBV genome, but three cell lines that were devoid of the EBV genome, were also sensitive. These lines included two lymphoid cell lines, one of them a T‐cell line, and a myeloma line. Fresh peripheral lymphocytes from normal donors or acute IM patients, PHA‐induced blasts and blast cells from a case of acute myeloid leukemia were resistant.
Effects of dibutyryl cyclic adenosine 3′: 5′ monophosphate and theophylline on 2‐deoxy‐D‐glucose and 2‐aminoisobutyric acid uptake by hamster embryo cells
Authors: Kuroki Toshio , Yamakawa Shigeyo
Published: February 2007

The uptake of 2‐deoxy‐D‐glucose by hamster embryo cells was stimulated by preincubation with 1 mM dibutyryl cyclic adenosine 3′:5′ monophosphate (dibutyryl cAMP) and theophylline for 24 h. The increase in uptake depended on the concentration of dibutyryl cAMP and was accelerated by a combination of dibutyryl cAMP and theophylline. The increased uptake of 2‐deoxy‐D‐glucose was reversed by removal of these chemicals. Lineweaver‐Burk plots of the uptake indicated that these chemicals caused an increase in the maximum velocity of 2‐deoxy‐D‐glucose uptake but no detectable change in the apparent Km. Hexokinase was not activated by preincubation of cells with 1 mM dibutyryl cAMP and theophylline. The uptake of glucose in nine other cell lines, including those from rat and mouse embryos, was not stimulated by these chemicals. In contrast to the uptake of 2‐deoxy‐D‐glucose, that of 2‐aminoisobutyric acid was inhibited by these compounds.
Comparative chemical analysis of indian bidi and American cigarette smoke
Authors: Hoffmann D. , Sanghvi L. D. , Wynder E. L.
Published: February 2007

Human data suggest an association between bidi smoking and cancer of the oral cavity, pharynx, larynx, esophagus and lung. The mainstream smoke of a popular Indian bidi and a popular US non‐filter cigarette were analyzed. Compared to cigarette smoke, bidi smoke has a high content of several toxic agents such as carbon monoxide (7.7 vs 3.5 vol. %), ammonia (284 vs 180 μg), hydrogen cyanide (903 vs 445 μg), phenol (250 vs 150 μg), other volatile phenols (264 vs 173 μg) and carcinogenic hydrocarbons, benz[a]anthracene (117 vs 81 μg) and benzo[a]pyrene (78 vs 47 ng). These chemical data suggest that the smoke of bidis has a carcinogenic activity and underline the need for bioassaying this inhalant.
Studies on a gross‐virus‐induced lymphoma in the rat. I. The cell‐mediated immune response
Authors: Shellam G. R.
Published: February 2007

The Gross virus‐induced lymphoma (C58NT) D, which was originally induced in the thymus of W/Fu rats, has been shown to be a virus‐releasing tumour with no detectable θ antigen or surface Ig. It is rapidly malignant in immunosuppressed rats with an LD50 of approximately 100 cells, but is strongly immunogenic in intact adult rats, inducing both long‐lasting immunity in vivo and a vigorous cell‐mediated immune response in vitro. A tumour challenge was rejected in an immune fashion within a maximum of 142 days after primary immunization, with the most rapid rejection at 9 and 62 days after immunization. CMI measured in an in vitro Cr51 release assay showed a sequential appearance in draining lymph nodes, thoracic duct lymph and the spleen with peak activity in days 6, 7 and 10 after immunization, followed by a rapid decline in activity. Spleen cells taken on the day of peak CMI adoptively conferred protection against tumour growth in vivo. The CMI response in vitro was shown to be specific for MuLV‐induced tumours, both by studying Cr51 release from a variety of tumour cells in the presence of immune spleen cells, and by comparing the ability of various unlabelled tumour cells to inhibit the lysis of Gross‐virus induced lymphoma cells by immune spleen cells. In addition purified Gross virus itself, but not NDV, was found to inhibit CMI in vitro. The effector cell in CMI in vitro was not removed by procedures which selectively depleted immune spleen cells of adherent and phagocytic cells and B lymphocytes. However, the removal of T lymphocytes either prior to immunization by thymectomy, irradiation and marrow reconstitution, or from immune spleen cells by the use of a specific antiserum, abrogated the CMI response. These results indicated that the effector cell in the in vitro assay was a T lymphocyte.
Urine œstrogen profiles OF Asian and North American women
Authors: MacMahon Brian , Cole Philip , Brown James B. , Aoki Kunio , Lin Tong Ming , Morgan Robert W. , Woo Ngai‐Chen
Published: February 2007

Œstrone (El), œstradiol (E2) and œstriol (E3) were measured in the urine of Asian and North American women aged 15‐19, 20‐24 and 30‐39 years, during the follicular and luteal phases of the menstrual cycle. Each urine specimen was characterized by its œstriol proportion, E3/(E1+E2+E3). In each age group and cycle phase Asians had lower concentrations of œstrone and œstradiol and a higher oestriol proportion than North Americans. The differences were greatest in the youngest age group. Differences between the women from two North American cities or between women from three Asian areas were small. The data support the idea that the œstriol proportion, especially among young women, is a correlate of subsequent breast cancer risk.
Enhancement of 3LL tumor growth by autosensitized T lymphocytes independent of the host lymphatic system
Authors: Carnaud Claude , Ilfeld David , Levo Yoram , Trainin Nathan
Published: February 2007

The present studies were performed in order to further investigate the paradoxical behavior of autosensitized lymphocytes which mediate 3LL tumor cytotoxicity when tested in vitro and promote tumor growth when tested in vivo. Using animals immunologically impaired by means of adult thymectomy and total‐body irradiation, it was observed that the tumor‐enhancing effect of autosensitized lymphocytes did not require the collaboration of host lymphocytes. Whereas bone‐marrow‐derived cells were devoid of activity, thymus‐derived cells were found to be the mediators of both in vitro cytotoxicity and in vivo tumor enhancement. These findings indicate that tumor enhancement mediated by in vitro autosensitized spleen cells was the result of a direct and specific interaction between committed T cells and self‐antigenic determinants carried by the tumor cells.
Immunoglabulin synthesis in tumors of human lymphoid origin serially transplantable in the neonatal syrian hamster
Authors: Pothier Lillian , Parke Pamela , Adams Richard A.
Published: February 2007

In attempting to relate immunoglobulin production to certain aspects of the neoplastic behavior of human lymphoid cells proliferating in vivo, we have analyzed the immunoglobulin cell products from 21 human tumor lines experimentally maintained in serial transplantation in neonatal hamsters. These lines were established in the neonatal hamster (usually facilitated by treatment with antilymphocyte serum) by direct implantation of cells from the patient, or after an intermediate stage in cell culture. Three lines derived from patients with acute lymphoblastic leukemia (conversion from lymphosarcoma) which also produced leukemic manifestations in the hamster, did not produce immunoglobulins. In all other lines, these being derived from patients with lymphosarcoma (without conversion to leukemia), infectious mononucleosis, Hodgkin's disease and Letterer‐siwe's disease, human immunoglobulin components were detected in the serum of the hamster host by immunodiffusion methods. With rare exceptions H‐chain was accompanied by L‐chain, these components being specific for the tumor line under investigation and without variation as to the class of H‐chain and type of L‐chain detected throughout observation periods of as little as 3 months or as much as 2 years. One line showed a sequential deletion of both H‐ and L‐chains. In another line an H‐chain not usually present was detected for a short time midway in passage.
Herpesvirus ateles: Transformation in vitro of marmoset splenic lymphocytes
Authors: Falk Lawrence , Wright John , Wolfe Lauren , Deinhardt Friedrich
Published: February 2007

Four lymphoblastoid cell cultures were established by transformation of marmoset splenic lymphocytes in vitro with Herpesvirus ateles (HVA). The association of HVA with each cell line was demonstrated by the recovery of HVA from the lymphoblastoid cells or from the culture fluids and by the demonstration of HVA antigens in a small percentage of cells of each lymphoblastoid culture. Intranuclear inclusion bodies were observed in three cultures examined but herpesvirus virions were observed in only one of three cell lines. The four cell cultures had properties of T‐lymphocytes.
Agglutination of normal and neoplastic human cells by concanavalin A and ricinus communis agglutinin
Authors: Glimelius Bengt , Westermark Bengt , Pontén Jan
Published: February 2007

Agglutination by two lectins, Con A and to a lesser extent ricin, has been investigated in human glia and glioma cells serially cultivated in vitro. No significant difference was found between the normal and transformed cells. The latter formed a spectrum where agglutination could be below or above the level of the control glia lines. Neither was there any difference between normal adult skin fibroblasts and two human sarcoma lines. We suggest that strictly normal cells in vitro are agglutinable by lectins such as Con A. This is also the case for most spontaneous, virus‐ or chemically transformed cells. We believe that exceptions to this rule—exemplified by lines such as 3T3, BHK and FE (a feline embryo line)—have acquired a membrane abnormality responsible for their low degree of agglutinability.
Early events in transformation of human cord leukocytes by epstein‐barr virus: Induction of dna synthesis, mitosis and the virus‐associated nuclear antigen synthesis
Authors: Aya Takao , Osato Toyoro
Published: February 2007

The present investigations were undertaken to establish the early events in EBV‐induced transformation of human cord lymphocytes with particular reference to the induction of DNA synthesis, mitosis and viral synthesis. When cord leukocytes were exposed to a 3 h pulse of2H‐TdR at 3 h intervals following EBV infection and examined by autoradiography, blastoid cells with labelled nuclei appeared 12‐24 h after virus exposure, reaching a maximum of 7.5% in 15 h. When the infected leukocytes were reincubated after each pulse for an additional 20‐40 h with colchicine added 10 h prior to termination of incubation, 18% of the positive cells were in mitosis. The cells were examined by immunofluorescence for the synthesis of EBV‐associated antigens. Early antigen (EA)—and viral capsid antigen (VCA)—were not detected, but EBV‐associated nuclear antigen (EBNA) synthesis became evident as early as 2 days after infection. The frequency of EBNA‐positive cells, mostly blastoid cells, increased with continued incubation, and at 10 days the majority of the cells were positive. These findings strongly suggest that the human cord leukocytes are non‐permissive for replication of EBV, and that the virus can induce in them early DNA synthesis followed by high‐frequency mitosis and cell proliferation, in close association of the viral genome with the host‐cell genome as shown by the synthesis of EBV‐specific “footprint”.
Immune responses of adenovirus type‐9 infected (tumor‐free) male rats against adenovirus type‐9 induced mammary fibroadenomas and A chemically induced mammary carcinoma
Authors: Steele G. , Ankerst J. , Sjögren H. O.
Published: February 2007

Lymphocytes from five non‐tumor‐bearing male W/Fu rats infected with human adenovirus type‐9 as newborns or as adults share a common reactivity against rat mammary fibroadenoma target cells and rat mammary carcinoma target cells, as demonstrated by microcytotoxicity tests. Mammary fibroadenomas were induced by adenovirus type‐9 infection of newborn female W/Fu rats, littermates of three of the male lymphocyte donors. The mammary carcinoma target cells were derived from a single rat mammary carcinoma induced by 3,2′‐dimethyl‐4‐amino‐biphenyl (DMABP). Lymphocytes from the male adenovirus type‐9 infected rats were not cytotoxic to normal rat breast epithelial cells, nor to target cells explanted from a polyoma‐virus‐induced sarcoma. Sera from each of five mammary fibroadenoma‐bearing female rats inhibited the cytotoxic effect of lymphocytes from the adenovirus type‐9 infected males against both mammary fibroadenoma and carcinoma target cells. Sera from the female W/Fu rat bearing the DMABP induced mammary carcinoma also inhibited the male lymphocyte cytotoxicity against both fibroadenoma and carcinoma target cells. Serum from rats bearing a polyoma‐virus‐induced sarcoma, though actively blocking in its own system, had no effect on lymphocytes from the adenovirus type‐9 infected males. Anti‐viral antibody response was demonstrated 8 days following adenovirus type‐9 infection of adult males. No anti‐tumor humoral response was demonstrated in either newborn‐infected or adult adenovirus type‐9 infected W/Fu male rats. Sera were checked for cytotoxicity against fibroadenoma and mammary carcinoma target cells in the presence of active homologous complement. No complement‐dependent cytotoxicity was evident. Sera from infected males were admixed to known blocking sera from mammary fibroadenoma‐ and carcinoma‐bearing rats, with no significant abrogation of the blocking effect. These results indicate that, despite the lack of tumor development, infection of male W/Fu rats by adenovirus type‐9 has produced an antigen which is at least partially common to the antigen (s) shared by adenovirus type‐9 induced mammary fibroadenomas and a DMABP induced mammary carcinoma.
Induction of polyoma tumors in athymic nude mice
Authors: Vandeputte M. , Eyssen H. , Sobis H. , De Somer P.
Published: February 2007

We verified the oncogenic effect ofpolyoma virus in gnotobiotic nude (nu/nu) mice compared to their gnotobiotic normal counterparts (nu/+). The nude mice were found to be much more sensitive to the oncogenic activity of the virus than were their heterozygote counterparts. This increased sensitivity is illustrated by the short latent period and by the high incidence of polyoma tumors in the nude mice inoculated with the virus several weeks after birth at a time when the nu/+ mice are completely resistant to polyoma oncogenesis.

Moreover, the cytolytic lesions observed in the kidney and in the salivary glands were also much more conspicuous in the nude mice. The results are discussed in relation to the role of immune surveillance in oncogenesis.
Random chromosome changes following SA7 transformation of syrian hamster cells
Authors: Popescu N. C. , Olinici C. D. , Casto B. C. , Dipaolo J. A.
Published: February 2007

The chromosome G banding technique was applied to Syrian hamster cells transformed in vitro by the carcinogenic virus SA7 or a combination of polycyclic carcinogenic hydrocarbon and SA7. Chromosome constitution of different clones varied; a normal diploid or an aneuploid constitution with minor structural or numerical deviation was found in some, while in others aneuploidy was associated with increased numerical changes as well as with abnormal chromosomes which are considered as markers. No consistent specific chromosome changes characterized transformation from SA7 or carcinogen pretreatment between the different pools of cells used. Although a lack of consistent chromosome pattern was associated with SA7 viral transformation, the possibility remains that extensive invisible minor genetic changes may have occurred.
Herpesvirus ateles: Properties of an oncogenic herpesvirus isolated from circulating lymphocytes of spider monkeys (Ateles SP.)
Authors: Falk Lawrence A. , Nigida Stephen M. , Deinhardt Friedrich , Wolfe Lauren G. , Cooper Robert W. , Hernandez‐Camacho Jorge I.
Published: February 2007

Herpesviruses were isolated from lymphocytes from four of eighteen spider monkeys imported recently from Colombia, South America. Virus was isolated after circulating lymphocytes were co‐cultivated with permissive cell cultures. Three isolates induced fatal malignant lymphomas in cotton‐topped and white‐lipped marmoset monkeys and one isolate which was also tested in squirrel monkeys caused no overt disease in this animal species. These virus isolates shared cross‐reacting antigens with Herpesvirus saimiri but possessed distinguishing biological properties.
Early appearance of a lymphoid arming factor and cytotoxic lymph‐node cells after tumor induction
Authors: Pollack Sylvia , Nelson Karen
Published: February 2007

An arming factor which collaborates with non‐sensitized lymphoid cells to produce specific killing of tumor cells in vitro appears in the serum within 24‐48 after initiation of a tumor by inoculation of Moloney Sarcoma Virus or a transplant of syngeneic sarcoma cells. Lymph‐node cells taken 1 or 2 days after tumor induction are also specifically cytotoxic in a microcytotoxicity assay. The production of this arming factor and the appearance of cytotoxic lymphoid cells are thus temporally related and are among the early responses to syngeneic sarcomas in BALB/c mice.
Cytotoxic antibodies to cultured lymphoblasts unrelated to epstein‐barr virus
Authors: Yang Czau‐Siung , Hewetson John F.
Published: February 2007

A micro‐51chromium‐release assay was used to examine the possible relationship between antibodies cytotoxic to lymphoid cells and EBV infections of the donors. No correlation was found between sera capable of killing lymphoid cells pre‐labelled with51 chromium and the presence or absence of antibodies to the viral capsid antigen (anti‐VCA). Sera obtained from patients with infectious mononucleosis, Burkitt's lymphoma, nasopharyngeal carcinoma and Hodgkin's disease known to have elevated titers to anti‐VCA showed cytotoxicity similar to control values. There appeared to be both heat‐stable and heat‐labile complement‐dependent cytotoxic antibodies.
Virus—host‐cell relationship of Herpesvirus sylvilagus with cottontail rabbit leukocytes
Authors: Wegner Dennis L. , Hinze Harry C.
Published: February 2007

Leukocyte suspensions from the lymph nodes, spleen and blood of cottontail rabbits experimentally infected with Herpesvirus sylvilagus were examined as fresh cell preparations and after in vitro cultivation for (1) the presence of virus, virus replication and release; (2) activation of virus by arginine deprivation or BUdR treatment and (3) the ability of such cell suspensions to give rise to actively replicating lymphoblastoid cell lines. Virus recovery was accomplished most consistently by co‐cultivation of viable cells on permissive DRK cell monolayers. The percentage of virus‐yielding cells, measured by formation of infectious centers when plated under agar on permissive monolayers, was generally less than 0.1%. Most cells yielding virus by this method showed no detectable intracellular virus in the sonically ruptured cell extracts. In vitro cultivation did not stimulate increased intracellular virus replication. It did, however, result in a 400‐ to 500‐fold increase in the number of cells capable of forming infectious centers in cultures of blood lymphocytes from two of 11 animals examined in this manner. Arginine deprivation of BUdR treatment also failed to activate productive infection. Maintenance of infected lymphoid cell cultures for 6 months did not result in establishment of actively replicating lymphoblastoid cell lines.
Tumour‐specific antibody neutralization of factors in rat hepatoma‐bearer serum which abrogate lymph‐node‐cell cytotoxicity
Authors: Robins R. A. , Baldwin R. W.
Published: February 2007

Serum from hepatoma‐bearing rats has been shown to abrogate the cytotoxicity of immune lymph‐node cells when added to the target cells (blocking) or the effector cells (inhibition). Neutralization of these in vitro blocking and inhibitory reactions by sera containing antibody to tumour antigen has been demonstrated. Serum taken after hepatoma excision counteracted tumour‐bearer serum blocking only when the sera were mixed in equal proportions; syngeneic immune serum and a rabbit antiserum to hepatoma cells were shown to be more effective in neutralizing tumour‐bearer serum blocking activity. The syngeneic immune and rabbit antisera were also more effective than post‐excision serum in counteracting the inhibition of lymph‐node cell cytotoxicity by tumour‐bearer serum. The rabbit antiserum and syngeneic immune serum were found to block lymph‐node cell cytotoxicity at the level of the target cell, but these sera themselves did not inhibit lymph‐node cell cytotoxicity. These findings suggest that two distinct types of blocking at the target‐cell can occur: firstly, by sera containing high concentrations of antibody; and secondly, by sera containing immune complexes. The first type of blocking could be due to antibody masking of target‐cell antigens. The second type of blocking may involve interaction of the antigen part of the bound immune complex with receptors on the effector cell, so preventing their subsequent recognition of target cells.
Tumour metastasis in mice with reduced immune reactivity. II. Studies with a highly antigenic MCA‐induced sarcoma in thymectomized and/or sub‐lethally irradiated C57BL/6J mice
Authors: Suurküla Mart , Boeryd Bernt
Published: February 2007

Spontaneous metastasis formation was studied in thymectomized and/or sublethally irradiated syngeneic C57BL/6J mice of a highly antigenic MCA‐induced sarcoma. The tumour has a low incidence of mainly pulmonary metastases in normal mice. The tumour was transplanted between 1 day and 3 months after irradiation. The immune competence was tested by the antibody response against SRBC and by studying the transplantation immunity against the tumour and allogeneic skin grafts. A wide range of immune‐suppressive states was obtained as shown by the antibody response against SRBC and by the transplantation immunity against the tumour. Local tumour growth at the transplantation site was more rapid in female than in male mice, but the difference was markedly reduced after the immunosuppressive procedures. This growth was slower in the thymectomized and irradiated groups than in the groups which were irradiated only, suggesting an inverse relationship between tumour growth and the degree of immunosuppression in this system. In contrast to this, tumour spread to lungs and lymph nodes was more pronounced in thymectomized and irradiated groups than in the groups irradiated only. The treatments caused varying and sometimes opposite effects on local tumour growth in the two sexes. The effect on tumour spread, if present, was always enhancing. Thus the effect of the two treatments on tumour growth was not similar to that on tumour spread. On some occasions the effects were even opposite to each other.