bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interactions between endogenous baboon type‐C virus and oncogenic viruses. I. Syncytium induction and development of infectivity assay
Authors: Ahmed Mumtaz , Korol Wlo , Larson David L. , Harewood Ken R. , Mayyasi Sami A. 
Published: February 2007

AbstractCells releasing the endogenous baboon virus (BV) can interact with human KC cells containing the Rous sarcoma virus (RSV) genome, resulting in cell fusion and syncytium formation. This interaction has been utilized in the development of a sensitive infectivity assay for BV. The titration pattern is of a one‐hit type, demonstrating a linear relationship between virus concentration and number of syncytial plaques obtained in the KC co‐cultivation assay. Endpoint titration comparisons indicate that the KC test is as sensitive as the immunofluorescence or the RNA‐directed DNA‐polymerase assays. Attempts to develop an XC test for BV failed, indicating that while BV can interact with the RSVgenome it will do so in the human KC cells and not in the rat XC cells. Syncytia are also induced when KC cells are directly exposed to cell‐free BV; however, a linear dose relationship is not obtained. When syncytium‐positive KC cultures are passaged, the syncytia disappear and a chronic BV infection is established. These KC‐BV cells then lose the ability to interact with either the endogenous cat RD‐114 virus or the Mason‐Pfizer virus which are known to form syncytia with KC cells.
Isolation of tumor‐specific antibodies from effusions of ovarian carcinomas
Authors: Dorsett Brent H. , Ioachim Harry L. , Stolbach Leo , Walker John , Barber Hugh R. K. 
Published: February 2007

AbstractPeritoneal effusions of patients with ovarian cancer contain sizable amounts of free and complexed immunoglobulins. By means of salt precipitation procedures, antibodies were recovered that after purification and concentration displayed a high degree of specificity against ovarian carcinoma cells. In indirect immunofluorescence, immunoglobulins recovered from seven different peritoneal effusions showed bright cytoplasmic staining with tissue cultures and fresh suspensions of ovarian carcinoma cells but not of normal ovaries or non‐ovarian tumors. Immunoglobulins isolated from fluids of benign ovarian cysts or from effusions of non‐ovarian tumors were negative in immunofluorescence tests. Autologous antibodies recovered from peritoneal effusions will be hopefully utilized in sensitive radioimmunoassay tests that are greatly needed for the early detection of ovarian cancer, the leading cause of death from gynecologic neoplasia.
Lymphocyte stimulation by autologous tumor cells in the presence of serum from the same patient or from healthy donors
Authors: Vánky F. , Klein E. , Stjernswärd J. , Trempe G. 
Published: February 2007

AbstractLymphocyte blastogenesis induced by autologous tumor biopsy cells, by allogeneic lymphocytes and by PHA, was performed in the presence of autologous or allogeneic serum collected from normal blood donors. In 13 of the 15 cases lymphocyte stimulation by autologous tumor cells was inhibited in the presence of autologous serum. In contrast, autologous serum somewhat enhanced the blastogenic effect of PHA and allogeneic lymphocytes.
Immune enhancement of the tumorigenicity of hamster brain tumor cells persistently infected with measles virus
Authors: Evermann James F. , Burnstein Theodore 
Published: February 2007

AbstractStudies were conducted on the tumorigenicity of a hamster brain tumor (HBT) cell line persistently infected with measles virus (MV). This cell population, termed HBT‐M, exhibited decreased tumorigenicity in weanling hamsters when implanted intracutaneously. The lowered tumorigenicity of the HBT‐M cells could be counteracted by concurrent hydrocortisone treatment restoring the tumor‐producing capacity to levels comparable to those of the highly tumorigenic HBT cells. It was also determined that prior immunization of hamsters with MV resulted in enhancement of tumor formation from usually subtumorigenic doses of HBT‐M cells. This increase in tumorigenicity appeared to correlate with high titers of MV antibody. Treatment of hamsters with cyclophosphamide resulted in a reduction of MV antibody titers and effected a decrease of HBT‐M cell tumorigenicity to control levels. Preliminary studies with passive immunizations indicated that the enhancing factor could be transferred in the sera from hamsters hyperimmunized with MV. These data suggested that MV antibody may potentiate the development of neoplasia of cells persistently infected with MV in a manner similar to the enhancement of tumor growth by blocking antibody.
Secondary specific immune response in vitro to MSV tumor cells
Authors: Senik A. , Hebrero F. Pozzo , Levy J. P. 
Published: February 2007

AbstractThe interactions which occur between antigenic tumor cells and normal or immune lymphoid cells in a 3‐day in vitro culture, have been studied with a murine sarcoma virus (MSV)‐induced tumor. The 3H‐thymidine incorporation of lymphoma cells growing in suspension, and the radioactive‐chromium release of freshly sampled lymphoma cells regularly added to the culture, have been compared to determine the part played by immune lymphoid cells in cytolysis and cytostasis of the tumor‐cell population. The cytolytic activity increases in the culture from day 0 to day 3. It is due, predominantly, to T‐cells, and remains specific to antigens shared by MSV tumors and related lymphomas. This activity would be difficult to detect unless freshly sampled ascitic cells were used as targets, since the lymphoma cells spontaneously lose a part of their sensitivity to immune cytolysis during in vitro culture. The method used in the present experiments is a secondary chromium release test (SCRT), which measures the in vitro secondary stimulation of cytotoxic T‐lymphocytes (CTL) by tumor cells. In the absence of stimulatory cells, the CTL activity would have rapidly fallen in vitro. The cytostatic activity also increases during the 3 days in vitro, in parallel to the cytolytic activity: it is due to non‐T‐cells and remains mainly non‐specific. The significance of these data for the interpretation of in vitro demonstrated cell‐mediated anti‐tumor immune reactions is briefly discussed, as well as their relevance in the in vivo role of immune CTL.
Selective and non‐selective lymphocytotoxicity in human melanoma: Observation on the effect of long‐term culture and fetal bovine serum on target‐cell sensitivity to lymphocytes
Authors: Mukherji Bijay , Vassos Douglas , Flowers Arlene , Binder Sheldon C. , Nathanson Larry 
Published: February 2007

AbstractIn vitro cell mediated cytotoxicity (CMC) assays have been conducted in a human melanoma system with a 3H‐proline retention technique. Melanoma target cells from long‐term cultures (“cell lines”) are found to exhibit increased susceptibility for lymphocyte cytotoxicity in comparison to the same target cells from short‐term culture. The higher sensitivity of the “cell line” derived target cells is seen with lymphocytes, irrespective of diagnosis of the donor. In parallel experiments with the target cells grown in medium supplemented with fetal calf serum (FCS) and AB+ human serum (from a normal male donor), the melanoma target cells grown with FCS do not show any enhanced cytotoxicity, suggesting no causal relationship of such enhanced sensitivity of “cell line” ‐derived target cells to “heterologous melanoma antigens” that might have been acquired by the target cells following the use of FCS in tissue culture. In controlled assays of in vitro CMC, lymphocytes from melanoma patients (14/44) exhibited selective cytotoxicity (destruction of only one target‐cell type) against the melanoma target cells, whereas only 3/97 control lymphocytes (other malignancies and normal donors) showed such melanoma‐selective cytotoxicity. This difference is statistically significant at p<0.001. Non‐selective cytotoxicity (destruction of two or more unrelated target cell types) was seen with lymphocytes from 9/44 melanoma patients, 13/51 patients with other malignancies and 8/46 normal donors. No correlation of selective cytotoxicity could be established with donors' age, sex, stage of disease, therapy or history of blood transfusion. Such a correlation may emerge as our series becomes larger. Despite the lack of any correlation between selective cytotoxicity and disease status, our study reaffirms the existence of selective cytotoxicity by melanoma patients' lymphocytes against melanoma target cells.
Studies on the role of macrophages in regulation of growth and metastasis of murine chemically induced fibrosarcomas
Authors: Wood Gary W. , Gillespie G. Yancey 
Published: February 2007

AbstractMurine solid tumors were shown to contain 9‐54% medium to large non‐malignant cells bearing receptors for immunoglobulin Fc. These cells rapidly adhered to plastic surfaces, were trypsin‐resistant, were capable of phagocytosis of latex particles and were sensitive to the lytic effects of anti‐macrophage serum and complement. Purified Fc‐receptor‐positive cells failed to produce tumors, which strongly suggested that they were macrophages. When tumor‐cell suspensions, depleted of macrophages by adherence to plastic surfaces, were injected subcutaneously into normal syngeneic mice, the tumors displayed an increased potential for metastasis. By contrast, control animals which received tumor‐cell suspensions containing their normal complement of macrophages invariably developed progressive localized tumors. The survival times of mice injected with macrophage‐depleted tumor‐cell suspensions were significantly shorter (p<0.05) than those for animals inoculated with intact tumor‐cell suspensions. These studies confirm the existence of a substantial number of macrophages within progressing syngeneic murine solid tumors and strongly suggest a regulatory role for the macrophages in the growth and metastasis of the tumor.
In vitro detection of cellular immunity to melanoma antigens in man by the monocyte spreading inhibition test
Authors: Mažuran Renata , Mujagic H. , Malenica B. , Silobrčic V. 
Published: February 2007

AbstractIn vitro inhibition of monocyte spreading (a correlate of cellular immunity) was used to detect cell‐mediated immune reactions of melanoma patients to specific melanoma antigens. Two soluble preparations of human melanoma antigens (MA‐1 and MA‐2) and one of a breast carcinoma (BCA) were prepared. The preparations were incubated in vitro with mononuclear cells isolated from the blood of 24 patients with melanoma, six patients with malignancies other than melanoma and 14 healthy donors. Spreading of monocytes from healthy donors was not inhibited by either MA‐1 and MA‐2 or BCA. MA‐1 and MA‐2 significantly inhibited the spreading of monocytes from patients with melanoma, while monocytes from patients with other malignancies were not affected. Spreading of monocytes from patients with melanoma was inhibited by the preparation of BCA. We conclude that inhibition of monocyte spreading can detect, in vitro, a cellular immune reaction to specific melanoma antigens in patients with melanoma.
EBV‐determined nuclear antigen (EBNA)‐positive cells in the peripheral blood of infectious mononucleosis patients
Authors: Klein George , Svedmyr Erick , Jondal Mikael , Persson Per Olof 
Published: February 2007

AbstractAfter removal of SRBC rosette‐forming T‐cells from the peripheral blood, the residual, largely B‐lymphocyte fractin of five infectious mononucleosis patients was found no contain 0.5‐2% blast cells, positive for the EBV‐determined nuclear antigen (EBNA). There was a rough parallelism between the presence of large lymphoblasts in the hematological smear, EBNA‐positive large blasts in the B‐cell fraction and the ability of the T‐cell fraction to expert an EBV‐specific lymphocytotoxicity on established cell lines in vitro. EBNA‐positive B‐cells and EBV‐specific killer T‐cells disappeared after the acute phase of the disease.
Characteristic chromosomal abnormalities in biopsies and lymphoid‐cell lines from patients with burkitt and non‐burkitt lymphomas
Authors: Zech L. , Haglund U. , Nilsson K. , Klein G. 
Published: February 2007

AbstractThe karyotypes of cells from 10 Burkitt lymphoma (BL) biopsies, eight cell lines established from BL and nine cell lines from non‐BL sources were studied by chromosome banding techniques. With the exception of the BL‐derived cell lines BJAB, GC‐BJAB, Maku and U‐8691 all biopsies and lines of Burkitt origin contained an extra band at the distal region of the long arm of one chromosome 14. An extra band on chromosome 14 was also found in cells of one non‐BL biopsy, in cells from a lymphosarcoma‐derived cell line and in a longestablished cell line derived from the pleural exudate of a patient with Hodgkin's disease. A distal region at the long arm of one chromosome 8 was missing in all metaphase figures of good technical quality in the same material. The size, morphology and stainability of missing region corresponded fairly well to the extra region at chromosome 14. We therefore suggest that the chromosome 14 marker represents a translocation between chromosomes 8 and 14,t (8q‐; 14q+). The translocation was present neither in lymphocytes of peripheral blood of five Burkitt patients nor in five lymphoblastoid cell lines of non‐BL origin. Trisomy 7 was found in two of the 10 BL biopsies, in two BL‐derived cell lines, in one non‐BL biopsy, in two lymphosarcoma‐derived cell lines and in one cell line derived from a patient with Hodgkin's disease.
Comparative studies of Epstein‐barr virus strains from Ghana and the United States
Authors: Gerber Paul , Nkrumah Francis K. , Pritchett Randall , Kieff Elliott 
Published: February 2007

AbstractA high incidence of oropharyngeal excretion of Epstein‐Barr virus (EBV) has been observed in African children with Burkitts lymphoma (BL) (48%) and matched controls (45%). This compares with an incidence of 77% in American patients with infectious mononucleosis (IM) and 13% in age‐matched controls. Cross‐neutralization tests between EBV strains derived from BL and IM patients and their sera failed to detect differences in the major neutralizing antigenic components. Cord‐blood lymphocytes transformed by American EBV expressed only early viral functions (EBV nuclear and soluble complement‐fixing antigens) and produced no detectable transforming activity. By contrast, cord‐blood lymphocytes transformed by African EBV strains contained 0.2‐0.3% of cells with EBV capsid and early antigen and produced EBV with transforming activity. These cells contained twice as many copies of EBV homologous DNA as the cells tranformed by American EBV strains.
Macrophage activation and anti‐tumor activity of biologic and synthetic agents
Authors: Morahan Page S. , Kaplan Alan M. 
Published: February 2007

AbstractSystemic administration of the synthetic immunopotentiator pyran, was as effective as the use of the biologic immunopotentiator BCG in activating macrophages and in inhibiting the Lewis lung carcinoma and MCA 2182 sarcoma. Several other synthetic polyanions also activated macrophages and exhibited some anti‐tumor activity, but none were as effectives as pyran. Cell‐wall fractions such as the Ribi vaccine and MER were considerably less effective than BCG. The anti‐tumor activity of pyran against the virtually non‐immunogenic Lewis lung carcinoma involved non‐specifically activated macrophages, and both anti‐tumor activity and macrophage activating ability persisted over a 100‐fold range of drug from 0.5 mg/kg to 50 mg/kg. The ability of activated macrophages to destroy tumor cells was abrogated by treatment with trypan blue, an inhibitor of macrophage lysosomal enzymes. In addition, preincubation of tumor cells with activated peritoneal cells at effector‐cell:target‐cell ratios of 20:1 and 5:1 markedly decreased tumor incidence and mortality. Glycogen‐stimulated or unstimulated peritoneal cells were completely inactive in inhibiting tumor growth in vivo or exhibiting cytotoxicity in vitro, demonstrating the requirement for activated macrophages selective for tumor‐cell destruction.
Tumor‐bound immunoglobulins. I. Further analysis of the characteristics of binding of immunoglobulins to In vivo‐grown tumor cells
Authors: Dorva G. , Klein E. , Witz I. P. , Wigzell H. 
Published: February 2007

AbstractImmunoglobulin (Ig) “coating” on different in vivo growing mouse tumors was investigated using several approaches. Radioiodine‐labelled purified protein A from Staphylococcus aureus, a specific ragent for Fc of IgG, and/or iodinated pruified antibodies against mouse immunoglobulins, were fixed by various in vivo‐grown mouse tumor cells, but not by the corresponding in vitro‐cultivated tumor cells. Removal of host macrophages from the in vivo tumor‐cell preparations did not affect the fixation of anti‐mouse Ig reagents by the tumor cells. After an initial lag period in vivo, the intensity of the Ig coating of tumor cells increased with time after tumor inoculation. Conversely, the detectable coating decreased rapidly as a function of time after ascites tumor cells were explanted in vitro at 37°C. Iodoacetamide did partially block this 37°C in vitro‐induced “uncoating process”. Surfacebound Ig could also be released from in vivo‐coated tumor cells treated at low pH in vitro. Analysis of the behavior of tumor‐bound Ig indicated a composite pattern. At the membrane level, uncoating was best shown with in vitro incubation favorable to cellular metabolism; however IgG was detected equally well in the supernatants of the cells, whether they were incubated at 37° C or at 4° C, and so for has failed to display antibody activity towards uncoated tumor cells. This was in contrast to the case of IgG released from ascites tumor cells cultured at low pH in vitro: such eluted Ig, when neutralized, could rebind to the “same” uncoated tumor cells. Under favorable metabolic conditions, the fate of tumor‐bound Ig might be one of internalization and/or of degradation.
Inhibition of cell‐mediated cytotoxicity to chemically induced rat tumours by soluble tumour and embryo cell extracts
Authors: Zöller M. , Price M. R. , Baldwin R. W. 
Published: February 2007

AbstractWhen lymph‐node and spleen cells from rats bearing or immunized against aminoazo dyeinduced rat hepatomas or 3‐methylcholanthreneinduced rat sarcomas were pretreated with 3 m KCl extracts of these tumours, their cytotoxicity for cultured cells from the corresponding tumour was specifically inhibited. In cross‐test combinations of target tumour and tumour‐bearer effector‐cell donor, tumour extracts only inhibited cytotoxic responses when they were derived from the tumour homologous to the target‐cell and not when the extract was from the tumour borne by the effector‐cell donor. One component of the tumour‐bearer cytotoxic response was shown to be directed against tumour‐associated embryonic antigens since soluble extracts of embryos or tumour extracts containing embryonic antigens inhibited tumour‐bearer cell‐mediate cytotoxicity in both specific and cross‐test combinations of target tumour and effector cells. These findings are discussed in relation to tumour antigen expression and the immune responses that these tumour‐associated antigens may evoke in tumour‐bearing rats.
Detection of private and common tumor‐associated antigens in murine sarcomas induced by different chemical carcinogens
Authors: Fritze D. , Kern D. H. , Humme J. A. , Drogemuller C. R. , Pilch Y. H. 
Published: February 2007

AbstractTwo fibrosarcomas of similar histological type, induced in C3Hf mice by either methylcholanthrene or 3,4‐benz(a)pyrene, were shown to have individually unique tumor‐rejection antigens in classical transplantation‐type experiments. By contrast, sera of autochthonous mice, which resisted only transplants of the immunizing sarcoma, were found to contain complement‐dependent cytotoxic antibodies, specific for both sarcomas, in vitro. The existence of individually unique as well as common tumor‐associated antigens in chemically‐induced murine sarcomas is suggested. The private. “tumor transplantation‐type” antigens elicited tumor rejection responses in vivo. The common tumor‐associated antigens, although immunogenic in autochthnous hosts, inducing the production of tumor‐specific antibodies, failed to induce transplantation crossresistance in vivo. This study supports the contention that, in carcinogen‐induced murine tumors, and perhaps in human neoplasms as well, the evaluation of humoral (and cell‐mediated) immune responses in vitro may not reflect tumor rejection‐type immune responses in vivo.
Dietary aflatoxins and human liver cancer. A study in Swaziland
Authors: Peers F. G. , Gilman G. A. , Linsell C. A. 
Published: February 2007

AbstractA 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

AbstractVarious 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

AbstractLymphocytes 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.