bluuebunny/crossref_metadata_2025 huggingface dataset:
Dietary aflatoxins and human liver cancer. A study in Swaziland
Authors: Peers F. G. , Gilman G. A. , Linsell C. A.
Published: February 2007

A study in Swaziland to assess the possible relationship of aflatoxin contamination and the incidence of primary liver cancer is reported. Aflatoxin ingestion levels have been determined in “food from the plate” samples collected over a 1‐year period. A significant correlation between the calculated ingested daily dose and the adult male incidence of primary liver cancer in different parts of Swaziland has been established. Samples of foodstuffs other than the plate samples also reflected the correlation of aflatoxin contamination and liver cancer. This study extends and amplifies the findings of an earlier study in the Murang'a district of Kenya and supports the hypothesis that aflatoxin ingestion is a factor in the genesis of primary liver cancer in Africa.
Attempts to demonstrate virus‐specific sequences in human tumors. IV. EB viral DNA in European burkitt lymphoma and immunoblastic lymphadenopathy with excessive plasmacytosis
Authors: Bornkamm Georg W. , Hausen Harald Zur , Stein Harald , Lennert Karl , Rüggeberg Fritz , Bartels Heinrich
Published: February 2007

Various biopsies from different European malignant lymphomas, two biopsies from nasopha‐ryngeal carcinomas, and material from non‐neoplastic lymph nodes were assayed for the presence of Epstein‐Barr virus (EBV) DNA by nucleic acid hybridization. Reassociation kinetics of in vitro‐labelled EBV DNA were studied in the presence of tumor DNA. The lymphomas tested included among others follicular lymphomas, germinocytomas, immunoblastic lymphomas and lymphoplasmacytoid immunocytomas. Epstein‐Barr viral DNA was demonstrated within the two nasopharyngeal carcinoma biopsies as expected. A histologically typical Burkitt lymphoma as well as an immunoblastic lymphadenopathy with excessive plasmacytosis also contained EBV‐DNA. The Burkitt biopsy revealed about 15 EBV genome equivalents per cell. Antibodies against EBV‐specific antigens were highly elevated in the serum of this patient. The material of the patient with immunoblastic lymphadenopathy contained 2‐3 EBV genome equivalents per cell.
Tumour‐associated lymphocyte cytotoxicity superimposed on “Spontaneous” cytotoxicity in melanoma patients
Authors: De Vries Jan E. , Rümke Philip
Published: February 2007

Lymphocytes from 16 stage 1, 6 stage II and 31 stage III melanoma patients (MP) and 51 healthy donors (HD) were tested as far as possible in parallel on a melanoma cell line (NK1‐4), a bladder carcinoma cell line (T 24) and 18 different short‐term melanoma cultures. Lymphocytes from MP and HD showed cytotoxic effects towards all three types of target cells. Lymphocytes from HD showed the strongest “spontaneous” cytotoxic effects on NKI‐4 cells whereas, in general, weak cytotoxic effects were seen on short‐term cultured melanoma cells. Within the different lymphocyte donor groups an enormous variation in cytotoxic effects was observed. However, the overall cytotoxic effects of stage I and II MP were significantly higher than those of the HD‐group. Stage I MP showed significantly stronger cytotoxic effects on NKI‐4 cells than on T 24 cells, indicating that tumour‐associated lymphocyte cytotoxicity was superimposed on spontaneous cytotoxicity.
Persistence of Epstein‐barr viral nuclear antigen (EBNA) in cells entering the eb viral cycle
Authors: Ernberg Ingemar , Masucci Giuseppe , Klein George
Published: February 2007

It was shown by double immunofluor‐escence studies that Epstein‐Barr viral nuclear antigen (EBNA) was preserved in EBV‐infected cells after they had entered the productive viral cycle, as signalled by the appearance of the early antigen (EA) complex. A nuclear component of the EA complex could be clearly distinguished from EBNA with regard to antigenic specificity.
The biology of human cells in tissue culture. I. Characterization of cells derived from osteogenic sarcomas
Authors: Smith Helene S. , Owens Robert B. , Hiller Alan J. , Nelson‐Rees Walter A. , Johnston James O.
Published: February 2007

We have extensively characterized cell lines derived from six human osteosarcomas. The growth properties of these cultures were compared to those of fibroblastic cultures derived from skin of osteosarcoma patients and skin of bone‐marrow of normal individuals. Each tumor‐derived line showed some but not all of the abnormal growth properties usually associated with malignant transformation, indicating that tumor cells rather than normal stromal cells had in fact been cultured. The parameters measured included saturation density, cell morphology, growth pattern, growth on contact inhibited monolayers of normal flbroblastic or epithelial cells and tumorigenicity in immunosuppressed mice. Although the skin fibroblasts from the osteosarcoma patients appeared normal in vitro, they showed a greater ability to grow in immunosuppressed mice than did normal fibroblasts. This observation suggests that all fibroblasts of osteosarcoma patients may have an increased propensity for malignant transformation.
Temperature‐sensitive DNA repair of ultraviolet damage in human cell lines
Authors: Goss Patricia , Parsons P. G.
Published: February 2007

Following exposure to ultraviolet irradiation (UV), two of three human fibroblast strains and one of three melanoma cell lines showed lower rates of thymine dimer excision during 24 h at 40° C than at 36° C. All lines had lower rates at 32° C. Autoradiographic studies of three fibroblast strains and four melanoma lines incubated for four hours after irradiation revealed decreased unscheduled DNA synthesis at 42° C compared with 36° C. The rate of semiconservative DNA synthesis was decreased at the upper temperature in both series of experiments. All eight cell lines tested showed decreased repair at 42° C, as judged by slower sedimentation and increased heterogeneity of parental DNA in alkaline sucrose gradients. Experiments using the DNA synthesis inhibitor Actinomycin D suggested that these effects were due to temperature‐sensitive repair synthesis. In the two lines studied, preincubation of cells at 42° C apparently increased the extent of UV damage. Although by no means conclusive, these results are consistent with the possibility that temperaturesensitive DNA repair is a contributory factor in some cases of solar carcinogenesis.
A cohort study on mortality from cancer and other causes among workers at a metal refinery
Authors: Tokudome Shinkan , Kuratsune Masanori
Published: February 2007

A non‐concurrent prospective study was made on deaths from cancer and other causes occurring among 2,675 male workers at a metal refinery from 1949 to 1971. The expected number of deaths computed by applying age‐ and cause‐specific death rates of Japanese males to these workers was compared with the observed number of deaths. Among 839 copper smelters, significantly increased mortalities were noted for lung cancer (SMR = 1,189) and colon cancer, but not for cancer of the stomach, liver (primary) and biliary passages, pancreas and skin or for leukemia, tuberculosis, cerebrovascular diseases, heart diseases and liver cirrhosis. A dose‐response relationship was demonstrated between the mortality from lung cancer and the degree of exposure. A very high excess mortality from lung cancer (SMR = 2,500) was seen among copper smelters who were considered to have been most heavily exposed to arsenic or workers who had engaged in sintering and blast furnace operations for 15 years of more before 1949. The latent period of lung cancer was 37.6 years on average, and not related to level of exposure. Twenty‐six of 29 deaths from lung cancer among copper smelters occurred after they had left the refinery. Other production workers and clerical workers showed no significant excess mortality from any kind of cancer.
Studies on a gross‐virus‐induced lymphoma in the rat. III. Optimisation, specificity and applications of the in vitro immune response
Authors: Bruce J. , Mitchison N. A. , Shellam G. R.
Published: February 2007

Conditions are described for optimal stimulation in vitro of lymphocytes from rats primed in vivo with syngeneic MuLV‐G leukaemia cells. Cultures generate effector cells which show high cytotoxic activity against leukaemic cells. Specific stimulation can be obtained with leukaemic cells and with disrupted MuLV. Leukaemic cells, normal spleen cells and the viron internal protein p30 competitively inhibit effector cells, but purified virus exerts nonspecific inhibition. These findings are interpreted as supporting the hypothesis that virion antigens constitute a major target of anti‐tumour cytotoxic immunity.
Monkey antisera with increased specificity to carcinoembryonic antigen (CEA)
Authors: Ruoslahti Erkki , Engval Eva , Vuento Matti , Wigzell Hans
Published: February 2007

Three Macaca irus monkeys were immunized with purified human CEA. One received unmodified CEA and two were immunized with haptenated (4‐hydroxy‐5‐iodo‐3‐nitrophenyl acetyl) CEA. All three monkeys formed precipitating antibodies to CEA. The antisera did not precipitate the CEA‐related normal glycoprotein antigen (NCA). In contrast, CEA‐immunized rabbits, sheep and goats invariably form antibodies against NCA. Radioimmunoassays showed the monkey antisera to contain trace amounts of antibodies to NCA but the titers were about 10‐1,000 times lower than those in rabbit and sheep sera with comparable anti‐CEA titers. These results show that monkeys produce antibodies against CEA, but respond weakly to a normal, CEA‐related antigen. The weak response to NCA suggests that monkeys may possess an NCA‐related antigen. Antisera lacking reactivity to normal CEA‐related antigens may be helpful in establishing a more specific diagnostic test for CEA.
Treatment of Burkitt's lymphoma: Randomized clinical trial of single‐agent versus combination chemotherapy
Authors: Olweny Charles L. M. , Katongole‐Mbidde Edward , Kaddu‐Mukasa Albert , Atine Isaac , Owor Raphael , Lwanga Stephen , Carswell W. , Magrath Ian T.
Published: February 2007

A randomized clinical trial designed to compare the effectiveness of cytoxan (CTX) alone versus a combination consisting of CTX, vincristine (Oncovin) and methotrexate (COM) in the treatment of Burkitt's lymphoma (BL) was carried out. Nineteen patients were selected at random to receive CTX alone while 21 received COM. The two treatment regimens were equally effective in inducing remissions, and complete response rates of 83.3% and 84.3% were observed for CTX‐ and COM‐treated patients, respectively. The relapse frequencies were also equal but the pattern of relapse was clearly different. Seven out of 8 (87.5%) in the CTX group relapsed with systemic and central nervous system (CNS) tumor, while 8 out of 10 (80%) in the COM group relapsed with CNS disease only. This difference is highly significant p = 0.008. The remission durations and survival to date are the same.
Clonal derivatives of a herpes type 2 transformed hamster cell line (333‐8‐9): Cytogenetic analysis, tumorigenicity and virus sequence detection
Authors: Copple Christine D. , McDougall James K.
Published: February 2007

The characteristics of the Syrian hamster cell line (333‐8‐9), putatively transformed by herpes virus type 2 (HSV‐2), strain 333, have been examined. The line has been cloned and the clones characterized cytogenetically and morphologically. The original line and the clones have been assayed for tumorigenicity and for the presence of herpes‐virus‐specific nucleic acid sequences using in situ hybridization with 125I HSV‐2 DNA. The line 333‐8‐9 is hyperdiploid with a mode of 49 chromosomes and contains a spectrum of cytogenetic marker chromosomes present in varying frequencies. The clones demonstrate a segregation of these marker chromosomes and other abnormal chromosomes. Cloned lines have distinct stem‐cell types with the characteristic abnormal chromosomes present in a high percentage of cells. Some of the marker chromosomes have been identified by Giemsa banding techniques. All the clones have distinctive, persistent in vitro morphologies, ranging from purely epithelial to purely fibroblastic. They differ from the line 333‐8‐9 and between themselves in tumorigenicity, varying from highly tumorigenic to entirely nontumorigenic. Herpes virus 2 specific sequences have been detected in the original cell line and in all but two of the clones. There does not appear to be any obvious correlation between the three parameters of: (1) detection of HSV‐2 information; (2) marker chromosome occurrence; and (3) tumorigenicity.
Prompt elevation of rat serum α‐fetoprotein by acute liver injury following a single injection of ethionine
Authors: Watanabe Akiharu , Taketa Kazuhisa , Miyazaki Masahiro
Published: February 2007

The mechanism of increased a‐fetoprotein (AFP) production following a single injection of ethionine was investigated by using rats aged 5 weeks at the time of killing. Marked elevations of serum AFP concentrations occurred within 4 days in both male and female rats after administration of DL‐ethionine or L‐ethionine, although the increased levels of serum AFP and liver triglyceride in the adults were less marked in the male than in the female. No apparent necrosis of liver cells was observed in ethionine‐treated rats. Frequent administrations of adenosine triphosphate after a single dose of ethionine prevented the increases in liver triglyceride and serum AFP levels. The increased concentrations of serum AFP, reaching a maximum level within 4 days, occurred before a slight increase in incorporation of 3H‐thymidine into liver DNA. The serum AFP from ethionine‐treated rats was immunologically and electrophoretically indistinguishable from that of fetal, carbontetrachloride‐treated or hepatoma‐bearing rats. These observations suggest that the increased production of AFP in ethionine‐treated rats is closely associated with hepatic injury and is not the consequence of liver cell regeneration.
Detection of tumor‐associated antigen in human melanoma cell line supernatants
Authors: Grimm Elizabeth A. , Silver Hulbert K. B. , Roth Jack A. , Chee Darwin O. , Gupta Rishab K. , Morton Donald L.
Published: February 2007

Spent tissue culture medium (CDM‐S) removed from a single cell line of human malignant melanoma grown in serum‐free CDM, contained tumor‐associated antigenic activity. Antibodies to CDM‐S measured by complement fixation were detected in 44% (31/70) melanoma, 55% (15/27) sarcoma, 63% (24/38) carcinoma and 15% (11/72) normal sera. Delayed cutaneous hypersensitivity reactions (DCHR) were demonstrated in 4/5 melanoma patients at a 500 μg dose, 3/5 at a 100 μg dose and in 1/7 carcinoma patients at the 500 μg dose. One ml of CDM‐S was shown to contain antigen equivalent to that obtained from the membranes of 2.9 × 107 tissue‐cultured melanoma cells. After purification, 84% (16/19) sera from melanoma patients, 66% (12/18) from sarcoma and carcinoma patients and 8% (2/26) from normal controls were positive to the antigen by complement fixation.
Establishment and characterization of a human histiocytic lymphoma cell line (U‐937)
Authors: Sundström Christer , Nilsson Kenneth
Published: February 2007

A human hematopoietic cell line (U‐937) with exceptional characteristics was derived from a patient with generalized histiocytic lymphoma. The morphology of the cell line was identical to that of the tumor cells in the pleural effusion from which the line was derived. Since Epstein‐Barr virus (EBV) carrying diploid lymphoblastoid cell lines unrelated to the tumor population often become established in vitro from non‐Burkitt lymphoma explants, several parameters were studied to discriminate the U‐937 from such lines: morphology in vitro, growth characteristics, cytochemistry, surface receptor pattern, Ig production, lysozyme production, β2‐micro‐globulin production, presence of EBV genome and karyotype. In all these respects U‐937 differed from prototype lymphoblastoid cell lines. The histiocytic origin of the cell line was shown by its capacity for lysozyme production and the strong esterase activity (naphtol AS‐D acetate esterase inhibited by NaF) of the cells. It is therefore concluded that the U‐937 is a neoplastic, histiocytic cell line.
Carcinoembryonic antigen‐like substances of human bile. Isolation and partial characterization
Authors: Svenberg Torgny
Published: February 2007

Three species of carcinoembryonic antigen (CEA)‐like macromolecules, called the biliary glycoprotein I, II and III (BGP I, II and III) were identified in human bile. BGP I was found in normal gall‐bladder bile and hepatic bile but not in bile subjected to inflammation (“white bile”). It was immunologically related to CEA and NGP (the “normal CEA‐like glycoprotein”. Synonyms: NCA, CCEA‐2, etc.). BGP I differed immunologically from CEA in that it lacked the tumor‐associated determinants of CEA. It was different from NGP (and CEA) in that it contained BGP I specific determinants as revealed by anti‐BGP I antibodies. In bile from gallbladders with obstructed outlet and subjected to cholecystitis, a non‐malignant inflammatory process, BGP I was replaced by BGP II and BGP III. Immunologically and physicochemically, BGP II and BGP III appeared to be closely similar to NGP and CEA, respectively.
Assessment of cell‐mediated immunity to malignant mesothelioma by microcytotoxicity tests
Authors: Embleton M. J. , Baldwin R. W. , Wagner J. C. , Wagner M. M. F. , Oldham P. D. , Jones J. S. P. , Sheers G.
Published: February 2007

Cell cultures were established from pleural effusions of patients with pleural mesothelioma, and peripheral mononuclear effector cells were tested for cytotoxicity against these cells by means of a microcytotoxicity assay. Effector cells were obtained from normal healthy donors and from persons exposed occupationally to asbestos, including apparently healthy persons, patients with benign pleural conditions and patients with malignant mesothelioma. The overall incidence of cytotoxicity was low, and there was no evidence of increased cytotoxicity in mesothelioma patients or other asbestos‐exposed donors. It is concluded that little or no tumour‐directed cellmediated immunity is detectable against malignant mesothelioma by microcytotoxicity methods.
Mortality from cancer of the uterus in canada and its relationship to screening for cancer of the cervix
Authors: Miller A. B. , Lindsay J. , Hill G. B.
Published: February 2007

Age‐standardized death rates at ages 30‐64 from cancer of the uterus in the 10 provinces of Canada have been assessed in 1950‐52, 1960‐62 and 1970‐72, and changes in rates over these periods related to screening for cancer of the cervix and variables derived from the censuses of 1961 and 1971. Death rates at the county and census division level have also been assessed for the provinces of Nova Scotia, Quebec, Ontario, Manitoba and Alberta for 1960‐62 and 1970‐72 and related to screening and census‐derived variables. There is little indication of a contribution of screening to the fall in death rates that occurred in eight of the 10 provinces from 1950‐52 to 1960‐62. There is, however, evidence of an important and significant contribution of the intensity of screening (as indicated by the numbers of cervical cytology examinations conducted in 1966 expressed as a rate per 1,000 female population aged 20 or more) to the fall in death rates at both the provincial and county or census division levels from 1960‐62 to 1970‐72, and this effect is not abolished by taking the census‐derived variables into account. It is concluded that a significant effect of intensity of screening on the reduction in mortality from cancer of the uterus in Canada in the age‐group 30‐64 over the period 1960‐62 to 1970‐72 has been demonstrated.
Rapid development of hyperplastic nodules and cirrhosis in the liver of rats treated concurrently with thioacetamide and the pyrrolizidine alkaloid lasiocarpine
Authors: Reddy Janardan K. , Rao M. Sambasiva , Jago Marjorie V.
Published: February 2007

Pyrrolizidine alkaloids have long been considered to be hepatotoxic in man as well as in grazing animals. To investigate the effect of liver cell division induced by thioacetamide on the hepatic changes induced by these alkaloids, rats were treated concurrently with thioacetamide and the pyrrolizidine alkaloid lasiocarpine. Thioacetamide was given intraperitoneally in a dose of 50 mg/kg b. wt twice weekly and lasiocarpine was administered in the diet at a concentration of 50 ppm. At 15 weeks, the combination of thioacetamide and lasiocarpine produced numerous grossly visible grey nodules in livers of 26 of 30 rats. Microscopically, these livers revealed a severe degree of postnecrotic cirrhosis and numerous hyperplastic nodules. The cells in most nodules were arranged in solid sheets or in a trabecular pattern and showed atypia, mitosis and hyperchromasia. In contrast, there was no evidence of cirrhosis or nodule formation in livers of animals treated with either lasiocarpine or thioacetamide alone. The rapid development of liver lesions in rats treated simultaneously with low doses of lasiocarpine and thioacetamide suggests that cell proliferation accentuates the development of neoplasia.
Human pregnancy‐specific beta1‐globulin and its relation to chorioepithelioma
Authors: Tatarinov Yu. S. , Falaleeva D. M. , Kalashnikov V. V.
Published: February 2007

Human serum pregnancy‐specific beta1‐globulin (beta1‐GP) was localized in paraffin sections of placenta and chorioepithelioma of the uterus by indirect immunofluorescence. The structures containing beta1‐GP but not human serum albumin were regarded as specifically associated with beta1‐GP metabolism. Beta1‐GP was found in trophoblastic cells of chorion and Langhans cells of chorioepithelioma. Using the immunoautoradiographic method (I131), we only found beta1‐GP in sera of patients with trophoblastic tumours: in 74.3% of 35 patients with chorioepithelioma and in 80% of 25 patients with hydatidiform mole and destructive hydatidiform mole. The diagnostic and prognostic significance of the immunochemical test for beta1‐GP in trophoblastic tumours is discussed.
AKR leukemia‐specific surface antigens acquired by malignant transformation: Their common and individual specificities
Authors: Okazaki Etsuo , Aoki Tadao , De Kozlowski Steven J.
Published: February 2007

Antisera against five newly established AKR spontaneous leukemias (KSL) prepared by immunization of KSL cells in (C57Bl/6xC3Hf/He)F1 mice were preabsorbed with non‐leukemic AKR lymphoid cells to remove antibodies against virus‐associated surface antigens and alloantigens. In absorption tests the antisera showed no cross‐reaction by immunofluorescence microscopy with thymocyte, fetal, male‐specific H‐Y, E and X.1 antigens; with known Gross murine leukemia virus‐associated antigens; or with cell surface antigens on Friend, Moloney and Rauscher virus‐induced tumors. It was thus shown that the antigens detected were leukemia‐specific, were acquired by malignant transformation, and consisted of two types: (1) a common antigen in all the KSL, and (2) individual antigens found in four of the KSL which showed distinct patterns of partial cross‐reactivity with the other KSL.
The induction of immunity against tumor cell transplantation with a complex of tumor cell surface substance and a serum component found in the Tumor‐Regressor animals
Authors: Egawa Kohji , Tanino Takae
Published: February 2007

Immunity against transplantation of MM2 cells, an ascites cell line of mouse mammary carcinoma, was induced in syngeneic C3H/He mice by intraperitoneal injection of a complex formed between a MM2‐specific cell surface component isolated from the cells and a serum factor found in the serum from MM2‐regressor and MM2‐bearing mice. The induced immunity was transferable to other mice with the spleen cells or with the serum from the immunized animals. This cell surface component was not immunogenic by itself. A new immunogenicity was induced in the protein moiety of this substance when the serum factor was bound to the polysaccharidecontaining part of the molecule. On the basis of these results, a biphasic mechanism for the induction of the humoral immunity against tumor antigens was proposed. The first phase takes place in tumorbearing animals and gives rise to the serum factor. The second phase, which is blocked in tumor‐bearing animals, consists of the induction of the humoral immunity by the complex in tumor‐free animals.
Cell line‐specific cell surface components of hypotetraploid ascites mammary carcinoma cells inducing humoral reactions in the syngeneic host
Authors: Tanino Takae , Saito Michiko , Egawa Kohji
Published: February 2007

Cell‐line‐specific cell surface components were demonstrated on cells of various hypotetraploid ascites cell lines, but not on hyperdiploid cells derived from a mammary carcinoma induced by mammary tumor virus (MTV) in syngeneic C3H/He mice. These substances caused cell‐line‐specific transplantation antigenicity and were identified, together with MTV‐associated substances and tumorassociated embryonic materials, as being the binding sites for tumor cell agglutinating factors found in sera from tumor‐bearing and regressor animals. Particles containing the cell line‐specific substances were released from these cells by hypotonic treatment. They could be purified as a single peak in a sucrose density gradient. They were, however, not dissociated from the MTV‐associated substances. Absorption studies of agglutination activity were extensively used for demonstration of specificity.
Specific sensitization of lymphocytes to tumor antigens by Co‐cultivation with peritoneal cells exposed to such antigens
Authors: Hellström Ingegerd , Hellström Karl Erik
Published: February 2007

Peritoneal cells from BALB/c mice were seeded into 50‐mm plastic Petri dishes and exposed either to antigen extracts prepared from individual BALB/c sarcomas having unique tumor‐specific antigens, to similar extracts prepared from 14‐ to 18‐day‐old mouse embryos, or to culture medium only. Lymphoid cells from BALB/c lymph nodes were then added to the peritioneal cells. Following 4‐5 days of co‐cultivation, the lymphoid cells were harvested and tested in a 30 h microcytotoxicity assay for reactivity against tumor cells carrying the respective sensitizing antigens as well as against control cells which consisted of either tumor cells lacking the sensitizing antigens or normal skin fibroblasts. By this approach sensitization to individually unique tumor antigens, as well as to antigens shared by mouse embryos and mouse sarcoma cells, was achieved.
Stimulation of transplanted 3‐methylcholanthrene‐induced sarcomas in mice by specific immune and by normal serum
Authors: Biddle C.
Published: February 2007

Serum from Bl × C3H mice carrying syngeneic, progressively growing, highly immunogenic 3‐methylcholanthrene‐induced tumors, when admixed with the specific tumor and inoculated into immunologically crippled syngeneic recipients, stimulated tumor growth as compared with serum from control normal mice. It appears that this acceleration of tumor growth is an immune effect since it is not present when a non‐immunogenic (spontaneous tissue culture) tumor is used; and the active factor can be absorbed from the serum by the specific tumor but not by an immunologically unrelated tumor. Normal serum per se also stimulated tumor growth, but to a smaller extent.
Phenotypic mixing of vesicular stomatitis virus and D‐type oncornavirus
Authors: Altstein A. D. , Zhdanov V. M. , Omelchenko T. N. , Dzagurov S. G. , Miller G. G. , Zavada J.
Published: February 2007

After mixed infection of cells with vesicular stomatitis virus (VSV, thermolabile mutant tl 17) and oncornavirus type D, phenotypically mixed virions are formed containing the VSV genome and oncornavirus and VSV envelope. The virions are thermostable and have serologic characteristics of both viruses.
Specific antigen of murine erythroblasts
Authors: Ievleva E. S. , Engelhardt N. V. , Abelev G. I.
Published: February 2007

A new antigen has been revealed by means of antisera against Rauscher virus in mice with Rauscher virus‐induced leukemia. This antigen appears to be different from both Rauscher type‐specific antigen and MULV‐gs‐1 (p‐30), as shown by studies of electrophoretic mobility and immunochemical specificity. Except in leukemic mice it was also found in low levels in both serum and spleen extracts of healthy mice of a number of strains. Furthermore, this antigen was regularly demonstrated by immunofluorescence on the surface of erythroblasts, but not on the surface of erythrocytes, lymphocytes, polymorphonuclear cells and thymocytes, and was shown to be different from fetal hemoglobin. Therefore, it is referred to as antigen of erythroblasts (Ag‐Eb), which seems to represent a surface marker for a certain differentiation stage of erythroid cells.
Independent regulation of two types of aryl hydrocarbon (benzo(a)pyrene) hydroxylase in mammalian cells
Authors: Huberman Eliezer , Yamasaki Hiroshi , Sachs Leo
Published: February 2007

Aryl hydrocarbon (benzo (a)pyrene) hydroxylase induced by dibutyryl cyclic AMP (dcAMP), plus aminophylline (AHH l) can be distinguished from the hydroxylase induced by benz (a) anthracene (AHH II) by its lower Km for benzo (a)pyrene. Treatment with the combination of benz (a) anthracene and dcAMP plus aminophylline induced both AHH I and AHH II activities. After optimal induction of AHH II activity by benz (a)anthracene, the addition of dcAMP plus aminophylline gave an induction of AHH I. Although AHH I activity declined to an almost basal level 24 h after treatment with dcAMP plus aminophylline, the addition of benz (a) anthracene prevented this decline. Inducibility by dcAMP plus aminophylline or by benz (a)anthracene varied in different cell lines. Some cell lines were induced by both substances, with a higher induction by benz (a)‐anthracene, while other lines were inducible only by benz (a)anthracene, and a third cell type was not inducible by either. Selection for resistance to benzo (a)pyrene of a cell line inducible by both compounds resulted in a fourth cell type which was mase inducible by dcAMP plus aminophylline than by benz (a)anthracene. The results suggest that theré is an independent regulation of hydroxylase AHH I and AHH II and that the induction of these two enzyme activities is determined by different genetic control.
Genetic role of rat macrophage cytotoxicity against tumor
Authors: Miller Glenn A. , Feldman Joseph D.
Published: February 2007

Macrophages from the Lewis (Le) rat strain are significantly more cytotoxic to a Moloney sarcoma tumor, both in vivo and in vivo, than are macrophages from the Brown Norway (BN) strain. Activity of macrophages from (Le × BN) F1 rats that are histocompatible with the Moloney sarcoma tumor is directed toward tumor and/or virus‐associated antigens and is expressed as a dominant genetic trait. Experiments with backcross rats suggest that the genetic factors are unrelated to the major histocompatibility locus (AgB) of the rats. BN macrophages, although not active against tumor and/or viral antigens, can become cytotoxic to cells displaying Le alloantigens.
Interactions of murine leukemia virus (MuLV) with isolated lymphocytes. II. Infection of B and T cells with friend virus complex in diffusion chambers and in vitro: Effect of polyclonal mitogens
Authors: Cerny Jan , Hensgen Patricia A. , Fistel Samuel H. , Demler Lynn Mastalir
Published: February 2007

The infection of isolated B and T cells by a murine leukemia virus (Friend) (MuLV‐F) was studied both in vitro and in vitro with an implanted diffusion chamber system. Lymphocytes were obtained from pools of normal spleen cells by filtration of the cell suspension through a nylon‐wool column. The purity for both Ig positive and theta‐positive cells varied between 85% and 90% in the B‐cell and T‐cell fractions; both lymphocyte fractions responded very well to stimulation with their respective specific polyclonal mitogens, bacterial lipopolysaccharide (LPS) and concanavalin A (Con A). Lymphocytes were infected by incubating pelleted cells in 2–6 × 104 FFU MuLV for 1 h at 4°C and were then cultured for 5–10 days. Cells releasing infectious MuLV were enumerated as infectious centers (IC). IC were readily detectable in the cultures of infected B‐cells but none were found in the T‐cell cultures. Addition of LPS to the culture medium increased the number of IC in B‐cell fractions up to 1,000‐fold. Furthermore, in T‐cell cultures with LPS, IC also appeared in numbers which approximately correlated with the contaminating Ig+ cells of the T‐cell fraction. In contrast, Con A had no consistent effect on the infection of either B or T cells. In the absence of MuLV‐F, mitogenic stimulation alone did not elicit any endogenous IC. In subsequent experiments, purified lymphocytes were infected in diffusion chambers in vivo. The number of IC in infected B cells increased 1,000‐fold as compared to infection in tissue culture. The peak of infection at 10 days was followed by a slight decline. Infected cells were also found in diffusion chambers containing T‐cell fractions; these IC had very similar kinetics to those in B‐cell‐containing chambers, but their number was 10 times lower, suggesting that the infected cells were B cells, which comprised about 10% of the T‐cell fraction. The virus‐related antigens were detectable by immunofluorescence on the membrane of cells recovered from B‐cell‐bearing chambers but not on cells from T‐cell‐bearing chambers.
Detection of anti‐tumor antibody in virally induced tumors and its relationship to tumor growth
Authors: Ting Chou‐Chik
Published: February 2007

The humoral antibody response to virally induced tumors in syngeneic hosts has been studied. The tumors include an SV40 tumor SVT2, the Friend virus‐induced leukemias FBL‐3 and FLC; and Moloney sarcoma virus‐induced tumors. It was found that anti‐tumor antibodies could be detected by the isotopic antiglobulin technique in these tumor systems at a relatively early stage of tumor growth. The kinetics of the antibody response in relation to the status of tumor growth varied between different tumors. In general, the antibody levels were higher in the hosts with progressive tumor growth than in the regressors or tumor‐free hosts. Reinoculation of tumor cells or recurrence of tumor growth produced elevation of antibody levels (secondary response). The specificity of the antibody reactions also varied in different tumor systems: some antibodies were truly tumor‐specific and thus might produce a biological effect on in vivo tumor immunity, whereas others were not. These studies indicated that a sensitive antibody assay could be used for early detection of tumor growth. However, its usefulness in evaluation of the status of tumor growth should be carefully studied in each tumor sys.
Natural antibodies directed against murine lympho‐sarcoma cells: Variability of level in individual mice
Authors: Pierotti M. A. , Colnaghi M. I.
Published: February 2007

Natural anti‐tumor antibodies (NAA) were revealed, by a complement‐dependent cytotoxicity test on EL4 lymphoma cells, in the serum of C3Hf but not of C57Bl mice. Hybrids between the positive C3Hf and the negative C57Bl mice were NAA producers. Individual variability of NAA level was found in C3Hf and in the hybrids. The study of mice housed in the same or in different cages and of mice belonging to the same or to different litters demonstrated a randomly distributed variability. These observations seem to exclude environmental influences on the natural immune response or genetic mutations in the C3Hf strain with the appearance of variants with different NAA content. The NAA level was age‐dependent with a peak around 20–24 weeks of age. Inoculum of lymphoma cells induced an increase in the NAA level both in C3Hf and in the hybrids but not in C57Bl mice which seem therefore incapable of making guinea‐pig complement‐fixing NAA. The individual variability of NAA level and the stimulating effect of tumor cells support a potential role of NAA in immunosurveillance of oncogenesis.
Production of tumor‐specific inducer of cellular cytotoxicity by lethally irradiated mice
Authors: Pollack Sylvia B. , Nelson Karen
Published: February 2007

Antisera taken 1 or 2 days after inoculation of BALB/c mice with transplantable sarcoma cells or Moloney sarcoma virus (MSV) induce tumor‐specific cell‐dependent cytotoxicity in vitro. In the present experiments, lethally irradiated (“immunosup‐pressed”) mice were tested for the early appearance of the serum factor responsible for this anti‐serum dependent cell‐mediated cytotoxicity (E‐ADC). BALB/c mice were injected with MSV, syngeneic sarcoma cells or sheep red blood cells 24 h following irradiation with 900 R. Sera were obtained from MSV and tumor cell recipients 48 or 72 h later and tested for E‐ADC activity. Spleen cells from SRBC recipients were tested at day 4 or 5 for ability to form direct plaques in a modified Jerne plaque assay. Although the anti‐SRBC response was obliterated in the irradiated mice, the E‐ADC response appeared to be unimpaired. These studies indicate that newly synthesized immunoglobulin is not required for the formation of the E‐ADC factor.
Circulating immune complexes in sera of patients with Burkitt's lymphoma and nasopharyngeal carcinoma
Authors: Heimer R. , Klein G.
Published: February 2007

Sera of individuals with Burkitt's lymphoma and nasopharyngeal carcinoma, tested by consumption of hemolytic complement, were found by comparison with healthy individuals to have significantly increased levels of circulating immune complexes. The identity of the immune complexes was established by sucrose density gradient ultracentrifugation, which showed them to sediment between 10 and 19S. As they were adsorbable by rheumatoid factor—Sepharose 4B conjugates, it appeared that these complexes were composed of IgG. The complexes were retained by Concanavalin A—Sepharose columns and eluted by alpha methyl‐D‐mannoside, suggesting by analogy with model complexes that the antigens might be glycoproteins.
Intra‐lesional injection of immunostimulants in bilateral rat tumors
Authors: Salomon J.‐C. , Galinha A. , Lascaux V. , Prin J. , Puvion F. , Lynch N.
Published: February 2007

Rats grafted with either two or six fragments of isogenic methylcholanthrene‐induced transplantable fibrosarcomas were treated IT1 with living BCG or killed C. parvum or a mixture of both immunostimulants. Various tumor combinations and therapeutic agent dosages were compared. When two fragments of the same tumor McFiFi2 (S) were grafted simultaneously, IT treatment of one of these with 2 mg of BCG induced cure of both in 50% of the animals, but IT injection of 2 × 109 C. parvum was completely without effect in this situation. The prognosis was however, improved when the dose of immunostimulant was increased. The best results were obtained when each individual tumor in rats with two or six simultaneous identical grafts were treated with a mixture of BCG and C. parvum. The combination of IT immunostimulant treatment and surgical excision of the treated lesion demonstrated a persistence of the curative effect on the remote untreated tumor. Double grafting with isologous non‐identical tumors revealed the influence of tumor burden and of the specificity of anti‐tumor action of the treatment. The distant specific regression obtained in this system implies a specific immunological mechanism mediated by effector cells and/or antibodies which can circulate, identify the target cell and destroy it. This is in accordance with morphological observations. The intimate contact between BCG and the growing structured tumor is necessary for the therapeutic phenomenon.
Survey of human lymphoblastoid cell lines and primary cultures of normal and leukaemic leukocytes for oncornavirus production
Authors: Klucis E. , Jackson Leanne , Parsons P. G.
Published: February 2007

Velocity sedimentation of uridine‐labelled cultures was found to be more reliable than isopycnic sedimentation in detecting oncornavirus production in lymphoid cells. Of 13 cell lines (including six derived from Burkitt's lymphomas and two from leukaemic leukocytes) only one, the leukaemia‐derived, Epstein‐Barr virus‐producing line QIMR‐WIL, showed any activity. The nature of the QIMR‐WIL particles was further defined by isolation of uridine‐labelled 70S RNA and by the simultaneous assay for reverse transcriptase and 70S RNA, but production of such particles was detected in only three of 10 assays. Pretreatment of cells with 5′‐iododeoxyuridine or culture in arginine‐free medium did not induce particle production. Syncytia assays using XC cells were negative. Of 13 primary cultures (nine samples of leukaemic leukocytes and four of cord leukocytes) treated with mitogens and subjected to inducing conditions, one (leukocytes from a patient with acute myelogenous leukaemia) showed evidence in successive assays of oncornavirus synthesis. The low and transient yield of oncornavirus‐like particles obtained in this work parallels that reported in previous studies of fresh lymphoid cells and primary cultures.
Specificity of serum from rodents immune to moloney C‐type virus‐induced tumours
Authors: Hogg Nancy M.
Published: February 2007

When cells are infected by C‐type viruses such as Moloney sarcoma/leukaemia virus, new antigens appear on the cell membrane. Mice and rats will respond immunologically to the antigen (s). It was uncertain whether the antigens were related to the viral structural proteins or to non‐virion, tumour‐specific surface antigens (TSSA) or both. In an125 I‐antiglobulin binding assay, Moloney virus completely blocked the binding of mouse and rat sera to virus shedding target cells, thus suggesting that mice and rats recognise only viral proteins. Mice responded to type‐specific and rats mainly to group‐specific determinants on the virus. Individual Moloney viral proteins were prepared using the guanidine HCl method and were used to block the binding of the rat anti‐Moloney immune serum to Moloney virus shedding target cells. By this method, it was demonstrated that the rat serum contains specificities for the viral proteins gp70 and p30, but it was not possible to detect any antibodies directed towards non‐virion or TSSA‐like molecules.
Studies on epstein‐barr virus‐related antigens. I. Indirect single radial immunodiffusion as a useful method for detection and assay of soluble antigen
Authors: Matsuo T. , Osato T. , Nishi S. , Hirai H.
Published: February 2007

A useful method for the detection and assay of Epstein‐Barr virus (EBV)‐related soluble antigen has been developed by the application of the indirect single radial immunodiffusion technique which is frequently used for quantitative measurements of immunoglobulins and other soluble proteins. When the extracts of EBV‐determined nuclear antigen (EBNA)‐positive non‐producer cells (Raji and NC‐37) were applied to agar plates containing seropositive human serum, followed by overlay with anti‐human IgG serum, ring‐shaped precipitates with high specificity were clearly evident. The size of such precipitin rings was proportional to the amount of the antigen. This method is simple and applicable for a quantitative assay of a particular EBV‐related soluble antigen and antibody and the sensitivity is equivalent to that seen with the complement fixation test.
Emergence of a subpopulation of lymphocytes bearing θ antigen and complement receptor during tumor growth
Authors: Epstein Robert S. , Lopez Diana M. , Ortiz‐Muniz Gabriel , Sigel M. Michael
Published: February 2007

Spleens from BALB/c mice transplanted with mammary tumors display a significant increase in the percentage of lymphocytes bearing complement receptors (CRL) while the percentage of cells bearing surface immunoglobulins (SIg) remains unchanged in comparison with that in spleens from normal animals. Upon separation on nylon columns, the increase in CRL in the spleens from tumor‐bearing mice was limited to the non‐adherent cell population. Simultaneous marker analysis disclosed that these CRL lacked detectable SIg. Indirect immunofluorescence indicated that these cells possessed theta antigen. Absence of SIg and the presence of theta antigen coupled with the restricted occurrence of these cells in the nylon‐non‐adherent population which responded to PHA and Con A but not to LPS indicate that these cells may constitute a subset of T cells. The paucity of this subpopulation of spleen lymphocytes in normal spleen suggests that their emergence is related to tumor growth.
Surface glycoproteins and concanavalin‐A‐mediated agglutinability of clonal variants and tumour cells derived from SV40‐virus‐transformed mouse 3T3 cells
Authors: Smets L. A. , Van Beek W. P. , Van Rooij H.
Published: February 2007

Cell strains isolated from an established line of SV40‐transformed mouse 3T3 cells (SV3T3) showed large variations in the various parameters of transformation, viz. saturation density, serum requirement, contact inhibition of movement and of growth and Concanavalin‐A‐mediated agglutinability. These cell strains were studied for changes in elution profiles of fucose‐labelled surface glycoproteins, using actively growing, untransformed 3T3 cells as controls. A cell strain established from a tumour arising after injection of wild‐type SV3T3 cells and SV3T3 cells grown in vitro in diffusion chambers, was similarly studied. Changes in surface glycoproteins were observed only in the tumour‐derived cell strain. The results suggest that alterations in surface glycoproteins are associated with the tumorigenic potential of the cells rather than with the transformed phenotype per se.
Sequential changes in the numbers of B and T lymphocytes and other leukocytes in the blood in Marek's disease
Authors: Payne L. N. , Rennie M.
Published: February 2007

Numbers of B, T and total lymphocytes, monocytes, heterophils, eosinophils and basophils have been examined in the peripheral blood of chickens between 2 and 42 days after infection with Marek's disease virus. During the stage of the acute restrictively productive virus infection of lymphoid tissues at 2–9 days after infection, absolute numbers of B cells, T cells, total lymphocytes and heterophils were increased, those of monocytes and eosinophils were decreased, and those of basophils were unchanged. The lymphoproliferative phase of the disease, from 21–42 days after infection leading to lymphoma formation, was accompanied by an increase in T cells, total lymphocytes and possibly eosinophils, and a decrease in B cells, monocytes, heterophils and basophils. The T‐cell increase following infection occurred only in female birds, and there were more lymphomas in females than in males. The increase in lymphocytes in the blood of six birds with leukemia was mainly due to an increase in T cells, but in one bird B cells were also increased. Blast cells and atypical lymphoid cells were increased in leukemic birds. Regression coefficients were calculated between different pairs of leukocytes in infected and uninfected birds at different stages of the disease. Particularly noteworthy were the associations between B and T cell numbers, which indicated constant proportions of these cells irrespective of total numbers, possibly due to a common control mechanism.
In vitro stimulation of mouse lymphoid cells by C1300 neuroblastoma cells or tumor membrane extracts
Authors: Revoltella Roberto , Bertolini Luisa , Diamond Leila
Published: February 2007

Spleen lymphoid cells from A/J mice recognize specific antigenic differences on the surface membranes of syngeneic C1300 neuroblastoma cells and incorporate 3H‐thymidine into DNA in unidirectional mixed cell cultures in the absence of isologous serum. The response requires an optimal ratio of responder to stimulator cells, and is detectable after 24 h. It is specifically blocked by the presence of a papainsolubilized crude membrane extract from the same neuroblastoma cells, the extent of inhibition being dependent on the concentration of the extract and the time when it is added to the cultures. Spleen cells from mice bearing the neuroblastoma respond earlier and incorporate more 3H‐thymidine than cells from unsensitized mice. The enhanced response of the primed spleen cells to the stimulator cells is similar to a secondary immune response and can be induced by soluble crude tumor extracts in the absence of stimulator cells.