bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of interferon on virus‐particle synthesis in oncornavirus‐carrier lines. II. Evidence for A direct effect on particle release
Authors: Billiau A. , Edy V. G. , Sobis H. , De Somer P. 
Published: February 2007

AbstractInterferon treatment of murine C‐type oncornavirus carrier lines results in a drastic inhibition of extracellular virus formation. When such cells are subcultured in the presence of interferon, synthesis of extracellular C‐type virus remains depressed until the interferon treatement is discontinued. Cell‐associated virus as seen in the electron microscope or as detected by uridine incorporation is not proportionally inhibited. Several possibilities to explain this discrepancy are tested. The most likely hypothesis is that interferon treatment primarily inhibits virus release.
Lactose synthetase induction by hormones in normal and tumorous GR mouse mammary tissue
Authors: Schulein M. , Daehnfeldt J. L. , Briand P. 
Published: February 2007

AbstractTo analyse the effect of hormones on protein synthesis in hormone‐induced GR mouse mammary tumors, a comparative study was made of the A and B protein contents of the hormone‐inducible enzyme lactose synthetase (EC 2.4.1.22). The A protein could be induced by estrone and progesterone separately and in combination in mammary glands of ovariectomized mice. Increased amounts were demonstrated during pregnancy, when peak levels were recorded in the lactating gland. A three‐fold increase was found in primary tumors as well as in transplanted hormone‐dependent and independent tumors, as compared to the level in normal mammary tissue. However, no significant difference could be demonstrated between A protein activity in the two types of tumors, and no further increase was observed in animals with independent tumors following hormonal treatment. The B protein could be demonstrated in normal mammary tissue of intact as well as ovariectomized animals. There was a decrease in pregnant animals, while peak values were recorded in lactating animals. A rise in B protein could be induced by estrone in normal mammary tissue. Progesterone blocked the induction. However, no significant level of B protein could be demonstrated in primary tumors or in transplanted hormone‐dependent and ‐independent tumors. Nor was any increase noted in animals with independent tumors after hormone treatment. We conclude that hormonal induction of B protein is repressed in GR mammary tumors. The A protein also is no longer hormone‐inducible, but the level is high compared to that of normal unstimulated mammary gland.
Cell‐mediated anti‐tumor immunity in oncorna virus‐induced tumors: Specific cytostasis of tumor cells by spleen and lymph‐node cells
Authors: Senik A. , De Gioroi L. , Levy J. P. 
Published: February 2007

AbstractThe cytostatic effect of lymphoid cell (LC) suspensions from MSV‐induced tumorbearing mice has been tested in the “cytostasis assay” (CA) according to Chia and Festenstein (1973). The target cells (TC) were syngeneic lymphoma cells in suspension. Specific cytostasis was observed mainly at low LC/TC ratios while non‐specific effects could be detected when ratios higher than 25/1 were used. The serum of MSV‐tumor‐bearing mice can either inhibit or stimulate immune cytostasis. Non‐immune lymphoid cells can be armed by this kind of stimulating serum which suggests that an indirect mechanism, possibly antibody‐dependent, is involved in this cell‐mediated immune reaction. The kinetics of the immune response in CA have been studied by comparison with the kinetics of the immune response which can be detected in the chromium release test (CRT) with the same target cells. The cytostasis response in CA persists long after tumor rejection while the CRT activity decreases rapidly, confirming that CA and CRT would probably detect two different effects of the immune lymphoid cells on the same target cells. These results are briefly dicussed.
Immunopathologic changes in patients with cutaneous malignant melanoma following intratumoral inoculation of BCG: Correlation with cell‐mediated immunity
Authors: Lieberman Ronald , Epstein William , Fudenberg H. H. 
Published: February 2007

AbstractSix patients with cutaneous melanoma were treated with intratumoral Bacillus Calmette‐Guérin (BCG). Four showed good responses with regression of injected and, frequently, of uninjected lesions, whereas two developed dissemination and died. Three of four responders remain in complete remission. Two straìns of BCG were used; there was no detectable difference in therapeutic efficacy. Three of four responders showed a significant increase in lymphocyte stimulation (LS) to melanoma antigens, and all responders showed a marked increase in phytohemagglutinin (PHA). Non‐responders showed no increase to either stimulant. All responders were negative for leukocyte migration inhibition (LMI) to melanoma antigens before BCG, but two of four responders converted to positive after BCG therapy. Of the non‐responders, one was positive and one was negative before therapy; there was no change following BCG. There was a marked increase in active rosette‐forming cells (RFCS) in all responders and in only one of two non‐responders. Preliminary studies suggest that BCG also affects the level of circulating inhibitors which abrogate the activity of immune lymphocytes to melanoma antigens. A definite sequence occurs following intratumoral BCG: (1) disruption of melanogenesis with release of pigment from tumor cells (3‐6 h); (2) inflammatory response of polymorphonuclear leukocytes (PMNS) and mononuclear cells which remain at the tumor periphery (6‐24h); (3) tumor‐cell death (24h); and (4) granulomas replacing tumor (2 weeks). The response to BCG resembles the immunologic and histopathologic changes observed in halo nevi. These studies suggest that BCG activates both tumor‐specific and non‐specific immune responses. Thus, in vitro parameters of cell‐mediated immunity (CMI) are affected by BCG and some, particularly LS, LMI and the active rosette test, seem to correlate with clinical response.
A microassay for humoral cytotoxicity demonstrating sublethal effects of antibody
Authors: Cleveland P. H. , McKhann C. F. , Johnson K. , Nelson S. 
Published: February 2007

AbstractA sensitive and objective microassay has been developed for detection of antibodies against tumor‐associated antigens of murine sarcoma cells, by measuring the ability of cells to incorporate 3H‐thymidine after exposure to immune serum and complement. The cytotoxic effect detected by this method reflects cytostasis as well as cell death. This study also demonstrated that incubation periods longer than 4 h are required for the maximum cytotoxic effects of immune sera on sarcoma cells to become manifest.
Cytotoxity of non‐T versus T‐lymphocytes from melanoma patients and healthy donors on short‐ and long‐term cultured melanoma cells
Authors: De Vries Jan E. , Cornain Santoso , Rümke Philip 
Published: February 2007

AbstractLymphocytes from 25 healthy donors were separated into T‐ and non‐T‐fractions by means of E and EAC rosette‐formation. The unfractionated lymphocyte population was tested simultaneously with E and non‐EAC rosette‐forming cells (T‐cells) and EAC and non‐E rosette‐forming cells (non‐T cells) on melanoma cells from cell lines and short‐term cultures. More frequent and stronger cytotoxic effects were seen on melanoma target cells from cell lines than from short‐term cultures. The cytotoxic effects of the unfractionated lymphocyte populations were always recovered in the non‐T‐cell populations. Occasionally also T‐cell cytotoxicity was seen on melanoma cells from cell lutes. Compared to the T‐cell effects, the non‐T cells always showed stronger cytotoxic effects. Lymphocytes from selected melanoma patients (patients with known cytotoxic lymphocytes) were also tested tegether with lymphocytes from healthy donors. The cytotoxic effects scored with the unfractionated melanoma patients' lymphocytes, which in general were stronger than the effects seen with the corresponding lymphocyte populations from healthy donors, again appeared to be located mainly in the non‐T‐cell populations.
Cellular immune response to virus‐specific antigen in hamsters bearing isografts of cytomegalovirus‐transformed cells
Authors: Murasko Donna M. , Lausch Robert N. 
Published: February 2007

AbstractThe immune response of hamsters to syngeneic transplants of hamster embryo fibroblasts (HEF) transformed by cytomegalovirus (CMV) was investigated. Using the microcytotoxicity assay it was found that spleen cells from tumor‐bearing hosts consistently killed both homologous tumor cells and CMV‐infected human embryonic lung (HEL) cells. No significant cytotoxicity was observed when uninfected HEL, normal HEF, or HEF transformed by herpes simplex virus type 1 (HSV‐1) or PARA‐(defective SV40)‐adenovirus 7 (PARA‐7) served as the target cells. Spleen cells from animals bearing isografts of HSV‐1‐ and PARA‐7‐transformed cells were cytotoxic for their respective tumor cells but not for CMV‐transformed cells. Further studies showed that spleen cells from CMV or CMV‐infected HEL immunized hamsters were specifically cytotoxic for CMV‐transformed hamster cells. No antibody cytotoxic for CMV‐transformed cells was detected in the sera of CMV or CMV‐infected HEL‐immunized hosts, or in sera from tumor‐bearing animals. The results corroborate previous serological data that hamster cells transformed by CMV express virus‐related membrane antigen (s), and demonstrate that such antigen (s) can induce a cell‐mediated immune response in the tumor‐bearing host.
Effect of the Fv‐1 gene on leukemia virus in mouse cell heterokaryons
Authors: Tennant Raymond W. , Myer Fred E. , McGrath Lorraine 
Published: February 2007

AbstractThe effect of the Fv‐1 mouse gene restriction of N‐ and B‐tropic mouse leukemia viruses was examined by determining the fate of the viruses in heterokaryons of permissive and non‐permissive cells. Virus expression in cultures of fused cells was analyzed by simultaneous autoradiography and fluorescent antibody assay, which permitted the detection of virus‐induced proteins specifically in heterokaryons or cells of either parental type. Heterokaryons were found to dominantly restrict both N‐ and B‐tropic virus, but not NB‐tropic virus which infects either cell type with equal efficiency. Fusion of permissive cells with non‐permissive cells at increasing intervals after infection showed that the restriction affects some virus function within at least 12 h of infection. These results indicate that the Fv‐1 gene locus, or gene product, affects some post‐penetration events required for virus protein synthesis.
Flow microfluorometry analysis of DNA content in chinese hamster cells following infection with simian virus 40
Authors: Horan P. K. , Jett J. H. , Romero A. , Lehman J. M. 
Published: February 2007

AbstractInfection of secondary Chinese hamster cells with SV40 virus induces a population of cells into consecutive S periods. These changes in DNA content were examined at various times post infection by means of flow microfluorometry (FMF) which enabled a kinetic analysis to be made. At 12 h post infection, a population of 6C cells was observed which was induced from late S or G2 cells. By 24 h post infection, cells at 8C, 10C, 12C, 16C, and intermediate DNA contents were detected. The induction of this population of cells occurred within the first 24 h post infection. At later time intervals, there was a decrease in total number of cells with DNA contents of 8C or 16C.
Immunochemical identification of beta1‐globulin of the pregnancy zone” in serum of patients with trophoblastic tumors
Authors: Tatarinov Yu. S. , Mesnyankina N. V. , Nikoulina D. M. , Novikova L. A. , Toloknov B. O. , Falaleeva D. M. 
Published: February 2007

AbstractSera from 181 patients, 37 of which suffered from trophoblastic tumors (hydatidiform mole, destructive hydatidiform mole, and chorioepithelioma of the uterus), 100 patients—with other forms of tumors and 44 patients with various gynecological diseases, were studied with the use of an immunological test for the detection of beta1‐globulin of “pregnancy zone”. In the control group there were 106 serum samples of women at different stages of pregnancy and 257 samples of normal adults (165 women and 92 men). Thus, 544 serum samples from patients and from normal adults were studied. The immunochemical test for the beta1‐globulin was positive in patients with trophoblastic tumors before surgical removal or before chemotherapy. After surgery and/or complete course of chemotherapy, the test for beta1‐globulin became, as a rule, negative. This globulin is detected also in normal pregnancy serum. It is supposed that the beta1‐globulin of “pregnancy zone” is synthetized in the placenta and is released in the circulation of women during normal pregnancy; also it is produced by cells of trophoblastic tumors. The diagnostic and prognostic significance of the immunochemical test for the “pregnancy zone” beta1‐globulin in trophoblastic tumors is discussed.
Effect of anti‐embryo immunization on methylcholanthrene‐induced sarcoma growth in BALB/c mice
Authors: Parmiani G. , Lembo R. 
Published: February 2007

AbstractThe effect of immunization with embryonic tissues on challenge with two methylcholanthrene‐induced fibrosarcomas (MCA‐I and II) has been studied in BALB/c mice. No anti‐tumor protection was elicited by multiple intrastrain pregnancies and by immunizing with either X‐irradiated or mitomycin‐C‐blocked cells of syngeneic or allogeneic embryos obtained from primiparous females. Enhancement was found in anti‐embryo immunized males, but not females, and in multiparous females upon transplantation of MCA‐I sarcoma cells. Immunization with syngeneic embryonic cells in complete Freund's adjuvant, with embryomas or with syngeneic embryos kept in cell‐impermeable diffusion chambers, resulted in an enhancement of MCA‐II cells while allogeneic embryonal immunization was ineffective. The immunologic nature of the phenomenon was supported by experiments in which immunosuppression prevented the development of the enhancing response in mice injected with embryonic tissues. In neutralization experiments neither lymphocytes nor serum from anti‐embryo‐immune or multiparous mice caused any stimulatory or inhibitory effect on the admixed tumor cells.
Report of the scientific meeting on some developments in the methodology of controlled clinical trials in cancer
Authors: Armitage P. , Block J. B. , Saracci R. 
Published: February 2007

AbstractThis paper summarizes discussions which took place recently between statisticians and medical practitioners about methodological developments in clinical trials in cancer. Some recent mathematical theories for the analysis of censored survival data enable comparisons to be made between the effects of different treatments without rigid assumptions about the shape of the survival curve, and taking into account various disturbing variables. The use of computers for data processing is increasingly important, and great benefits can be derived from the use of general computer programs. Many clinical studies of new agents are of limited value because of the inadequacy or absence of controls. The value of randomization is well known, but some attention is being given to the possibility that randomization might be dispensed with in certain circumstances. Another possibility is the use of special methods of allocation which tend to place the majority of patients on the better treatment. These various suggestions for new approaches to the design of trials are especially important in view of the large number of possible questions to be investigated by trials and the limited resources available.
Demonstration of epstein‐barr virus‐associated nuclear antigen in nasopharyngeal carcinoma cells from fresh biopsies
Authors: Huang D. P. , Ho J. H. C. , Henle W. , Henle G. 
Published: February 2007

AbstractFresh nasopharyngeal carcinoma (NPC) biopsies were treated in several ways to yield satisfactory cell preparations for detection of Epstein‐Barr virus (EBV)‐associated nuclear antigen (EBNA) by anti‐complement immunofluorescence tests. If the cells were well dispersed (trypsinization or extensive mechanical dispersal) few or none of them were EBNA‐positive. In contrast, if the biopsy preparations contained small to moderately sized tissue fragments (touch preparations or limited mechanical dispersal), nuclear staining was detected in nearly every cell at the margin of the fragments or in cell sheets protruding from them. The stained cells corresponded to the carcinoma cells when compared to histologically stained replicate cell preparations. Nuclear staining was obtaining with anti‐EBNA positive sera [healthy donors, NPC patients, convalescents from infectious mononucleosis (IM)], shown to be free of antibodies to other nuclear antigens, but not with anti‐EBNA negative sera (healthy donors or patients in the early acute phase of IM). These results confirm and extend previous reports that the carcinoma cells harbor EBV genomes. The implications of these findings are discussed.
Cell surface antigen induced by avian tumor viruses in hamster cells transformed by a temperature‐sensitive mutant of rous sarcoma virus
Authors: Aupoix Michèle C. , Biquard Jean‐Michel , Cachard Annie 
Published: February 2007

AbstractHamster cells (BHK21/13) transformed at the permissive temperature by a temperature‐sensitive mutant (FU 19) of the Schmidt‐Ruppin strain of Rous sarcoma virus exhibited a temperature‐dependent expression of virus‐induced surface antigen (VISA) as assayed by mixed haemadsorption test. This temperature‐dependence of VISA was not observed in cells transformed by the wild‐type virus (SR4), although the number of positive cells was reduced at the restrictive temperature (41° C) when compared to cells incubated at the permissive temperature (37° C). The relations between cell transformation and expression of VISA are discussed.
Effect of ethidium bromide and fractionated X‐irradiation on rauscher leukemia development
Authors: Okunewick James P. , Brozovich Barbara J. , Kuhnert Paul M. 
Published: February 2007

AbstractStudies were carried out to evaluate further the in vivo effectiveness of reversetranscriptase inhibitors in the therapy of Rauscher viral leukemia. Ethidium bromide, given in multiple doses, was found to be without significant effect on the survival of mice which already had established Rauscher disease as the result of injection with virus 2 weeks earlier. However, the initiation of ethidium bromide treatment immediately after virus did result in the beneficial effect of an increase in the mean survival time of the infected animals. On the other hand, at the virus titers used, 4‐N‐benzyl‐4‐N‐demthylrifampicin showed no significant therapeutic action in either case, even though other studies had suggested that it might be effective for this purpose. A total of 1,000 R of fractionated X‐irradiation given to animals with established leukemia also resulted in increased mean survival times, but the combination of irradiation and ethidium bromide treatment of similar mice resulted in only a marginal improvement over irradiation alone. It is suggested that these reverse‐transcriptase inhibitors, though active against the free virus, may not be effective against the already transformed tumor cell.
Specific tumor‐induced suppression of lymphocyte activity in the antibody‐dependent tumoricidal reaction
Authors: Stolfi R. L. , Stolfi L. M. , Fugmann R. A. , Martin D. S. 
Published: February 2007

AbstractAlthough lymphocytes from normal, unsensitized CD8F1 mice demonstrated an antibody‐dependent cytotoxic reaction against syngeneic breast tumor cells in vitro, lymphocytes from mice carrying breast tumors exceeding 1 g in weight invariably failed to demonstrate cytotoxicity against cells from the lymphocyte donor's tumor in the antibody‐dependent reaction. Further, the tumor‐induced suppression of this antibody‐dependent lymphocyte reactivity was found to be tumor‐antigen‐specific, in that lymphocytes from an animal bearing a large tumor nevertheless were capable of participating in an antibody‐dependent cytotoxic reaction against syngeneic breast tumor cells that were antigenically distinct from those of the lymphocyte donor. The specificity of suppression of antibody‐dependent lymphocyte reactivity observed here indicates that only a small sub‐group of those lymphocytes with potential for antibody‐dependent cytocidal reactions actually participates in the reaction against any one particular antigen. This suggests a previously unrecognized antigen specificity at the level of the effector cell in the antibody‐dependent cytotoxic reaction.
Functional and biochemical parameters of activation related to macrophage cytostatiic effects on tumor cells
Authors: Keller R. , Keist Ruth , Ivatt R. J. 
Published: February 2007

AbstractThe cytostatic action of non‐immune, activated peritoneal rat macrophages (AM) on tumor targets largely depends upon the duration of their culture in vitro. AM show full cytostatic activity for the first 12‐24 h of culture followed by gradual loss. This distinctive pattern of cytostatic activity displayed by AM was compared with the course of a variety of functional, metabolic and biochemical parameters. DNase, RNase, esterase, acid phosphatase, glucose oxidation and cellular adherence remained unchanged or decreased whereas prolonged culture led to an increase in activity of other lysosomal enzymes. Pinocytosis and phagocytosis were most marked in macrophages between 12‐60 h whereas elevation in macrophage protein synthesis was high only after 4 to 12 h of culture, followed by a gradual decline. Thus the capacity of macrophages to stop proliferation of tumor targets closely parallels the level of protein synthesis, whereas other parameters of macrophage function such as lysosomal enzymes, glucose oxidation, cellular adherence, pinocytosis and phagocytosis, manifested a clearly different timecourse.
The mechanism of the autonomy of division of ascitic tumor cells
Authors: Malenkov A. G. , Artamonova V. A. , Kakushkina M. L. , Slivinsky G. G. , Voejkov V. L. 
Published: February 2007

AbstractA bovine serum gradient was used to separate ascites tumor cells into fractions according to size and position in the cell cycle. Cells from different fractions were treated with RNase or tween 80, and the influence of this treatment on protein synthesis, membrane permeability and dry mass of the cells was studied. The results suggest that the treatment triggered events in G1 cells which may resemble processes needed for the initiation of normal cell growth.