bluuebunny/crossref_metadata_2025_split huggingface dataset:
Suppressor cell activity in melanoma patients. I. Relation to tumor growth and immunoglobulin levels in vivo
Authors: Werkmeister J. , McCarthy W. , Hersey P. 
Published: February 2007

AbstractThe effect of tumor growth on the suppressor cell activity of melanoma patients was examined by measurement of immunoglobulin produced in vitro in pokeweed mitogen (PWM)‐stimulated cultures of B and T lymphocytes. B and T cells were separated by sheep red blood cell resetting and suppressor cell activity was assessed by comparison of immunoglobulins produced in cultures with irradiated T cells (2,000 rads) to that with unirradiated T cells. In the majority of patients with localized melanoma, radiosensitive suppressor T cells were detected and appeared to be an augmentation of a normal physiological state. In patients with Stage I and II melanoma, removal of the tumor resulted in a significant decrease in suppressor activity against IgA and IgM but not against IgG production. Similar sequential changes in suppressor cell activity were not generally detected in patients who had surgery for skin graft after previous removal of the primary melanoma or in patients undergoing surgery for non‐malignant conditions. Sequential studies on the levels of serum immunoglobulins showed an apparent trend for immunoglobulins to increase after surgery. Of particular importance, the decrease in in vitro suppressor cell activity against IgM and IgG production after tumor removal in individual patients was significantly associated with an increase in immunoglobulin levels in the serum of these patients. It is suggested that these findings may account in part for the absence of detectable antibody responses to melanoma antigens in many patients and for the generalized immunodeficiency in patients with disseminated melanoma.
Differentiation antigens expressed by epithelial cells in the lactating breast are also detectable in breast cancers
Authors: Arklie J. , Taylor‐Papadimitriou J. , Bodmer W. , Egan M. , Millis R. 
Published: February 2007

AbstractTwo monoclonal antibodies, 3.14.A3 and 1.10.F3, raised against a delipidated preparation of the human milk fat globule and characterized as epithelium‐specific (Taylor‐Papadimitriou et al., 1981) were assayed histologically, by an indirect immunoperoxidase technique, against formalin‐fixed, paraffin‐embedded, normal and tumour tissue sections, in order to establish their in vivo specificity. Both antibodies bound to less than 10% of the alveoli and ducts in the resting breast, but bound to all areas of alveoli, ducts and secretion in the lactating breast. Binding was to the luminal surface of the alveolar and ductal epithelium. Antibody 3.14.A3 showed positive reactions with each of 20 primary breast carcinomas tested, and with metastatic lesions in lymph nodes from six of these. Antibody 1.10.F3 also reacted with most of the primary carcinomas but not with those of the mucoid type nor with metastatic lesions in lymph nodes. When tested against a variety of normal tissues, 1.10.F3 bound only to the luminal epithelial surface of classically defined exocrine glands, to their associated ducts and to the collecting tubules of kidney and bronchioles of the lung. 3.14.A3 showed a similar pattern of binding to 1.10.F3 but also bound to sweat glands, the alveolar epithelium of lung and the luminal epithelium of the ductuli efferentes of the epididymis. The only tumours, other than breast, showing a positive reaction with the antibodies were adenocarcinomas of the lung, uterus and ovary.
Plasma prolactin levels and age in a female population: Relation to breast cancer
Authors: Bulbrook R. D. , Wang D. Y. , Hayward J. L. , Kwa H. G. , Cleton F. 
Published: February 2007

AbstractPlasma prolactin levels have been measured in over 4,000 normal women. The relation between hormone levels and age fits a cubic equation. It is suggested that a curve of this nature would generate the observed ageincidence curve for breast cancer, if prolactin were a carcinogen or promoter.
Characterization of clones of tumorigenic feline cells transformed by a chemical carcinogen
Authors: Rhim J. S. , Koh K. S. , Chen A. , Essex M. 
Published: February 2007

AbstractTumorigenic clonal lines derived from soft agar colonies induced by DMBA‐transformed feline embryo cells were isolated and characterized, the morphologically altered clonal cells formed large aggregates, growing in this aggregate form when suspended in liquid growth medium above an agar base and forming colonies in soft agar with high efficiency. When inoculated into athymic nude mice, chemically altered clonal cells produced progressively growing sarcomas. Cells established from the tumors morphologically resembled the DMBA‐transformed feline embryo cells and were characterized as cat cells by karyological analysis. The tumorigenic lines were negative for feline oncornavirusassociated cell membrane antigen (FOCMA), and for “gag‐X” the transformation‐related polyprotein which is encoded by the replication defective feline sarcoma virus.
Carcinogenic activity in rats of combined treatment with cyclophosphamide, methotrexate and 5‐fluorouracil
Authors: Habs Michael , Schmähl Dietrich , Lin P. Z. 
Published: February 2007

AbstractA total of 240 outbred Sprague‐Dawley rats were treated with 3 different doses of the cyclophosphamide‐methotrexate‐5‐fluorouracil (CMF) regimen adopted from clinical chemotherapy studies in breast cancer patients. Eighty untreated rats served as controls. Individual and total doses of the drugs applied were lower than corresponding doses used in human adjuvant therapy protocols compared on a mg/m2 basis. Lifelong observation of the animals demonstrated a strong doserelated carcinogenic response to the tested scheme. Main target organs of treatment‐related neoplasms were the nervous system, the hematopoietic and lymphatic tissue, the urinary bladder, and the suprarenal gland. It is concluded that the CMF drug combination evokes carcinogenic responses in several organ systems in the rat and should be regarded as representing a carcinogenic risk to humans. Uncritical clinical use of the three‐drug protocol should be avoided.
Phosphorylation of chromosomal proteins from mammary cell lines
Authors: Lai David Y. , Bustos Sergio E. , Howard Eugene F. 
Published: February 2007

AbstractPhosphorylation of histone and non‐histone chromosomal proteins in two clonal mouse mammary cell lines having low (V‐14) ande high (T‐19) tumorigenicity was investigated. Logarithmic phase cells were incubated in medium containing 125 μCi/ml[32P]‐orthophosphate. Cell nuclei were isolated, chromosomal proteins (histones and non‐histones) extracted and their amino acid composition, protein/DNA mass ratios, 32P‐uptake and gel electrophoretic patterns examined. Significant differences in the histone and NHC‐protein phosphorylation of these two cell lines were found. Comparison of radioactivity profiles of electrophoretically separated T‐19 and V‐14 NHC‐proteins showed that 60 % of the T‐19 bands in the mol. wt range of 160,000 to 15,000 daltons had increased [32P]‐orthophosphate uptake. Differences in histone radiolabelling between V‐14 and T‐19 were confined to the HI, H3 and H4 classes. [32P]‐ATP‐pool measurements of V‐14 and T‐19 at 30,60 and 120 min of incubation were similar, hence the difference in 32P‐uptake was not due to ATP‐pool fluctuations. Results of studies on growth rate, growth potential and the possibility that comparisons were made between cells at different stages of the growth cycle indicated that these variables did not account for the higher phosphorylation of T‐19 chromosomal proteins. The increased [32P]‐phosphate uptake into T‐19 cell protein was correlated with an elevated content of NHC and histone proteins and pointed towards a correlation between the degree of phosphorylation and the high tumorigenicity of this cell line.
Activation of the epstein‐barr virus genome by 5‐aza‐cytidine in latently infected human lymphoid lines
Authors: Ben‐Ssson Shmuel A. , Klein George 
Published: February 2007

AbstractRecent studies indicate that gene expression in higher eukaryotes is accompanied by a decrease in the frequency of 5‐methyl cytosine residues around the activated site (Razin and Riggs, 1980). 5‐aza‐cytidine (5‐aza‐C) is an analogue that reduces cytidine methylation in DNA (Jones and Taylor, 1980) and has been reported to change the differentiation pattern of cultured mouse embryo cells (Taylor and Jones, 1979). We have tested its ability to activate the Epstein‐Barr virus cycle in latently EBV‐infected human lymphoid lines. After an incubation period of 6 to 8 h with the drug, early antigens (EA) were induced in a substantial fraction of the cells in all six lines tested that had a low rate of spontaneous viral antigen production. Optimal conditions for EA induction were defined. The efficiency of 5‐aza‐C was comparable to the inducing effect of iododeoxyuridine. EBV‐DNA and EBNA positive virus‐non‐producer lines did not respond to 5‐aza‐C treatment. The findings are discussed in relation to the possibility that changes in EBV‐gene expression may be related to the state of DNA methylation.
Reversibility of the transformed and neoplastic phenotype. I. Progressive reversion of the phenotype of X‐ray‐transformed C3H/10T1/2 cells under prolonged treatment with interferon
Authors: Brouty‐Boyé Danièle , Gresser Ion 
Published: February 2007

AbstractX‐ray transtormed mouse C3H/10T1/2 cells were cultivated and passaged in the continuous presence of partially purified mouse interferon. This prolonged interferon treatment resulted in a stepwise progressive reversion of the transformed phenotype to the non‐transformed phenotype. Thus interferon‐treated cells displayed an epithelioid morphology, grew to a lower cell density, and were no longer tumorigenic. Reversion to the non‐transformed phenotype was, however, stable only as long as interferon was continuously present in the culture medium. When interferon was removed, the cells “back reverted” to the transformed phenotype. Our results suggest that interferon induced a reversion of the transformed phenotype in the entire cell population rather than a selection of an interferon resistant cell population. C‐type viral particles and significant levels of reverse transcriptase were present in transformed cells, but neither present in the parental 10T1/2 cells nor in interferon‐treated cells. When interferon was removed from the culture medium, viral particles and reverse transcriptase activity were again detected. It is possible, therefore, that interferon induces reversion through it; antiviral activity, or that it induces reversion by its effects on cell function and structure, independently of any antiviral effect. Inhibition of cell multiplication per se does not appear to be sufficient to induce reversion, since cycloheximide inhibited cell multiplication; however, even after ten passages, it did not affect tumorigenicity. Our results suggest the possibility that interferon may act in vivo not only by inhibiting tumor cell multiplication but also by inducing a reversion. Patients with some tumors may therefore benefit from long‐term interferon treatment.
Feline leukemia ‐ unique and cross‐reacting antigens on individual virus‐producing tumors identified by complement‐dependent antibody
Authors: Grant Chris K. , Michalek Michael T. 
Published: February 2007

AbstractFollowing exposure to feline leukemia virus (FeLV), cats that resist leukemia produce complement dependent antibodies (CDA) which lyse leukemia cells in the presence of cat complement. The CDA activity has been shown to be directed to feline oncornavirus‐associated cell membrane antigen (FOCMA) found on the surface of most feline leukemias. Despite the retrovirus etiology of feline leukemia, and the ubiquity of FOCMA expression by individual tumors, we found that CDA activity did not cross‐react when five feline leukemia lines were compared (FL74, F422, 3272, 3281, and 79–14940). Profiles for CDA mediated lysis of the leukemia target lines were determined for sera from 149 FeLV exposed cats, and animals were identified whose sera would selectively lyse almost any possible combination of tumors from one to five lines tested. Cross absorption and cold target inhibition studies were performed on selected sera, and a spectrum of different antigens was identified which included both individual determinants and antigens shared by some of the tumor lines. Leukemias FL74 and F422 carried a cross‐reactive determinant which was distinct from a second antigen shared by 3272 and 3281; lines F422, 3272 and 3281 each also carried a unique antigen. Leukemia 79–14940 did not cross‐react with other target tumor lines. Targets of CDA mediated lysis on leukemia cells maybe associated with normal feline cell surface antigens, because CDA titers were sometimes reduced after serum absorption with normal cat spleen cells. The relevance of multiple FOCMA determinants is discussed in terms of tumor escape from immunity.
Modulation of the expression of alkaline phosphatase genes in a human malignant cell line passaged through nude mice
Authors: Benham Frances J. , Balaban Gloria , Boccelli Denise , Harris Harry 
Published: February 2007

AbstractHep 2/5 cells, a clone of HeLa which expresses both placental‐type alkaline phosphatase and fetal intestinal alkaline phosphatase (ALP), were grown as solid tumors in nude mice. Analysis of ALP isozymes present in tumor specimens excised at intervals over a 52‐day period showed that levels of placental‐type ALP had dropped markedly, while levels of the intestinal ALP remained fairly constant. Cells re‐cultured from two two separate tumors regained most of the original placental ALP levels. However, levels of the fetal intenstinal ALP in cells returned to culture rapidly increased to more than six times the levels in the original cultured cells, and these increased levels persisted. Passage through nude mice thus induced at least semi‐permanent changes in the level of expression of fetal intestinal ALP in Hep 2/5 cells, and the nature of these changes may relate to the role of the isozyme locus in malignant cells.
Characterization of a rabbit anti‐human malignant glioma antiserum
Authors: Schnegg Jean‐Franlois , de Tribolet Nicolas , Diserens Annie‐Claire , Martin‐Achard Alec , Carrel Stefan 
Published: February 2007

AbstractAn antiglioma antiserum was produced by immunization of a rabbit with membrane‐enriched preparations of a human malignant glioma cell line, LN‐18. After extensive absorption, this antiserum reacted exclusively with antigenic determinants present on seven out of 16 malignant glioma cell lines tested, as shown by complement‐dependent cytotoxicity in a 51Cr‐release assay. This glioma specificity could be further confirmed by quantitative absorption experiments where cells from a glioma line, LN‐135, abolished the cytolytic reactivity of the antiserum against four other glioma lines. The step‐wise absorption of the crude antiserum consisted of: step 1, absorption with normal peripheral blood lymphocytes from 10 individual donors; step 2, absorption with a pool of cells from four different lymphoblastoid cell lines and one endometrial carcinoma; step 3, absorption with cells from a colon carcinoma; and step 4, absorption with cells from two different melanoma lines. After each absorption step the antiserum was tested by complement‐dependent cytotoxicity against a large panel of malignant glioma lines and control non‐glioma cell lines. After the absorptions from step 1 and 2 the antiserum reacted with all cell lines tested, while after step 3 absorption, it reacted only with cells from malignant glioma, melanomas and fetal brain. Quantitative absorption experiments performed at this stage with fetal brain cells showed that the reactivity for fetal brain and melanoma cells could be abolished, while the antiserum was still cytolytic for malignant gliomas. After the absorption from step 4, the antiserum reacted exclusively with seven malignant gliomas. After a further absorption with normal adult brain homogenate, the antiserum still reacted with four of the seven malignant glioma cell lines. Thus, the antiserum described here recognized three types of antigens: antigens common to cells of neuroectodermal origin, antigens shared by malignant gliomas and adult brain, and antigens expressed only on some gliomas.
Cholesterol metabolism in cancer cells in monolayer culture. III. Low‐density lipoprotein metabolism
Authors: Gal David , Macdonald Paul C. , Porter John C. , Simpson Evan R. 
Published: February 2007

AbstractThe metabolism of low‐density lipoprotein (LDL) was studied in neoplastic and non‐neoplastic cells of human gynecological origin, in monolayer cultures. The neoplastic cells were derived from epidermoid vaginal carcinoma, epidermoid cervical carcinoma and endometrial adenocarcinoma, in various degrees of differentiation. The non‐neoplastic cells were cervical fibroblasts and epithelial cells from proliferative endometrial glands. Both neoplastic and non‐neoplastic cells assimilated and degraded LDL in a similar fashion to other human cells (e.g. skin fibroblasts). However, the neoplastic cells metabolized LDL at a higher rate than the non‐neoplastic cells (e.g. epidermoid cervical cancer cells metabolized LDL at a 20 times higher rate than did cervical fibroblasts). Such a high rate of LDL metabolism probably enables continuously replicating cancer cells to obtain the large amounts of cholesterol required for cell membrane synthesis. If a high rate of LDL metabolism proves to be a general property of cancer cells, such a property could prove useful for tumor chemotherapy, providing cytotoxic chemicals could be incorporated within the LDL molecule.
Epstein‐Barr virus strain‐ and group‐specific antigenic determinants detected by monoclonal antibodies
Authors: Mueller‐Lantzsch Nikolaus , Georg‐Fries Brigitte , Herbst Hermann , Hausen Harald Zur , Braun Dietmar G. 
Published: February 2007

AbstractIn order to differentiate Epstein‐Barr virus (EBV) strains by serological markers we prepared hybridomas producing monoclonal antibodies against polypeptides of the QIMR‐WIL EBV strain. These monoclonal antibodies were screened by indirect immunofluorescence techniques. Immunoprecipitation, using EBV‐positive monoclonal antibodies and the protein A method, of 125I‐labelled polypeptides from purified QIMR‐WIL EBV particles, revealed that a series of monoclonal antibodies against the four main surface and envelope polypeptides precipitating p340, p340/p240, p140, and p80 were obtained. When 125I‐labelled polypeptides from purified P3HR‐I and B95‐8 EBV particles were immunoprecipitated, it could be demonstrated that several anti‐p340 (QIMR‐WIL) antibodies recognized strainspecific antigenic determinants, while anti‐p340/p240 (QIMR‐WIL) as well as anti‐p140 (QIMR‐WIL) antibody clones reacted with antigenic sites which are in common wither among B95‐8 or in addition to P3HR‐I polypeptides. Thus, monoclonal antibodies now provide a serological basis for EBV typing.
Cultivation of human melanomas in soft agar. Factors influencing plating efficiency and chemosensitivity
Authors: Tveit Kjell Magne , Fodstad Øystein , Pihl Alexander 
Published: February 2007

AbstractAs part of a programme to study the predictive clinical value of a soft agar assay for measuring chemosensitivity of human melanomas in vitro, we have observed the effect of three disaggregation methods on the yield of tumor cells, plating efficiency in soft agar and chemosensitivity. The yields and plating efficiencies obtained, as well as sensitivity to DTIC, CCNU, vinblastine and abrin, were about the same whether collagenase/pronase/DNase‐treatment, trypsin/EDTA‐treatment or mechanical treatment was used. When melanoma xenografts of different sizes were studied, an inverse relationship between tumor size and plating efficiency was found, whereas chemosensitivity was unaffected by tumor size. The highest plating efficiencies of melanoma cells, both from patient biopsies and from xenografts, were obtained when red blood cells were present and a low oxygen concentration (5%) was used. The results demonstrate that, in the case of melanomas, the fraction of tumor cells that are clonogenic in vitro depends on the size of the tumors, and even more so on the culture conditions used. An important finding was that chemosensitivity in vitro appears to be unaffected by the disaggregation method and by tumor size.
Sequential changes in peripheral blood leukocyte adherence inhibition (LAI) reactivity during progressive growth and spontaneous regression of canine transmissible venereal sarcoma
Authors: Harding Matthew W. , Yang Tsu‐Ju (Thomas) 
Published: February 2007

AbstractSequential changes in canine transmissible venereal sarcoma (CTVS) extract‐induced leukocyte adherence inhibition (LAI) reactivity of peripheral blood leukocytes (PBL) were monitored in dogs from the time of tumor inoculation through progressive growth and spontaneous regression or surgical excision of CTVS. The time‐course profiles of LAI reactivity of tumor dog PBL correlated with the clinical stage of tumor growth, substantiating our previous findings in a cross‐sectional study. The kinetics of the time‐course appearance of LAI reactivity observed and the demonstration of a rapid anamnestic response following tumor challenge indicate further that LAI is a reliable in vitro measure of in vivo tumor immunity. A significant increase in CTVS antigen extract‐induced LAI reactivity observed in the PBL during tumor regression suggests that LAI reflects a functional effector cell mechanism associated with spontaneous regression of CTVS. By contrast, absence of significant LAI reactivity of PBL during progressive tumor growth suggests the presence of serum blocking factors. In addition, a substantial rebound in LAI reactivity observed in the PBL of dogs 3 to 7 days following surgical excision of progressively growing CTVS provides further evidence that tumor‐cell components are associated with progressive tumor growth and diminished LAI reactivity.
Hodgkin and sternberg‐reed cell antigen(S) detected by an antiserum to a cell line (L428) derived from Hodgkin's disease
Authors: Stein Harald , Gerdes Johannes , Kirchner Hartmut , Schaadt Michael , Diehl Volker 
Published: February 2007

AbstractAntisera to the cell line L428, derived from Hodgkin's disease, were raised in rabbits by injecting L428 cells intravenously and subcutaneously. The anti‐L428 cell serum that did not react with HLA‐DR was absorbed with tonsil cells plus acute myeloid leukemia cells or tonsil cells plus neutrophils, monocytes, and blood lymphocytes. Then it was tested for its ability to discriminate between L428 cells, Hodgkin and Sternberg‐Reed cells, and various other cells. It was found that the anti‐L428 cell serum absorbed with tonsil cells plus acute myeloid leukemia cells stained only L428 cells, Hodgkin and Sternberg‐Reed cells, and neutrophils. The anti‐L428 cell serum absorbed with tonsil cells plus neutrophils, monocytes, and blood lymphocytes reacted with L428 cells and Hodgkin and Sternberg‐Reed cells from 13 cases of Hodgkin's disease. It did not react with any other cell type present in the blood or in lymphoid tissue or with cells from five cases of non‐Hodgkin's lymphoma. The absorbed anti‐L428 cell serum also failed to stain Daudi and HRIK cell line cells. We conclude that the anti‐L428 cell serum defines an antigen that is apparently restricted in expression to L428 cells and Hodgkin and Sternberg‐Reed cells. This is a strong indication that the L428 cell line cells are derived from Hodgkin and Sternberg‐Reed cells.