bluuebunny/crossref_metadata_2025_split huggingface dataset:
Augmentation of tumoricidal activity of human monocytes and macrophages by lymphokines
Authors: Mantovani Alberto , Dean Jack H. , Jerrells Thomas R. , Herberman Ronald B. 
Published: February 2007

AbstractMonocytes were separated from peripheral blood mononuclear cells of normal human donors by adherence on plastic conditioned by cell lines (microexudatecoated plastic) and harvested by exposure to ethylene diamine tetra‐acetic acid. Cytolytic activity was tested by incubating effector cells for 48 h with the murine SV40‐transformed TU5 kidney line or the human lung cancer‐derived CaLu line prelabelled with tritiated thymidine. Lymphokine‐containing supernatants were obtained from in vitro cultures of lymphoid cells with phytohemagglutinin (PHA)1, purified protein derivative (PPD), or with Corynebacterium parvum strains CN6134 or CN5888. The monocytes had significant levels of spontaneous cytotoxicity and exposure to lymphokine supernatants markedly enhanced their tumoricidal activity. Augmentation of monocyte‐mediated cytotoxicity required a minimal exposure to lymphokine supernatants for 4 h and was maximal after 24 h of preincubation. Treatment of the effector cells with anti‐human T‐cell serum and complement did not affect either their spontaneous or their lymphokine‐stimulated cytotoxicity, whereas silica impaired both reactivities. Supernatants of cultures with PHA, PPD and C. parvum CN6134 had significant levels of interferon (IF). Since partially purified human fibroblast or leukocyte IF was able to stimulate monocyte‐mediated cytotoxicity, the IF in these supernatants could play some role in the stimulation of the monocytes. However, C. parvum CN5888 supernatants, which had little IF, enhanced monocyte cytotoxicity as effectively as the C. parvum CN6134 supernatants, strongly suggesting that lymphocyte mediators other than IF can augment the tumoricidal activity of these effector cells. Mature macrophages obtained by in vitro cultivation of monocytes for 4–7 days retained natural cytolytic activity and showed enhanced cytotoxicity in the presence of lymphokines. However, more prolonged in vitro cultivation (> 10 days) resulted in cultures of epithelioid and multinucleated cells which had little natural cytotoxicity and were not responsive to lymphokines.
Antibodies reactive with the mouse mammary tumor virus in sera of breast cancer patients
Authors: Witkin Steven S. , Sarkar Nurul H. , Kinne David W. , Good Robert A. , Day Noorbibi K. 
Published: February 2007

AbstractIgG binding to purified mouse mammary tumor virus (MuMTV) was quantitated by an enzyme‐linked immunoassay (ELISA) using sera from patients with breast cancer or benign breast disease, or from healthy agematched controls. Significantly greater binding (p<0.01) was found in breast‐cancer‐derived sera than in the other categories. In addition to IgG reactivity, three breast cancer sera also possessed IgA and IgM reactive with MuMTV by the ELISA assay. Only IgG was reactive in the majority of sera while two sera possessed MuMTV binding activity only in the IgM fraction. Both IgG binding and virolysis of MuMTV were greatly reduced by preincubation of sera with MuMTV. The specificity for MuMTV was further explored with IgG of serum from one breast cancer patient. Human antibody reactive with MuMTV was progressively diminished by preincubating the human serum with increasing concentrations of MuMTV but not by incubation with the type‐C AKR murine leukemia virus. Preincubation of MuMTV with a breast cancer serum partially blocked the reactivity of gp52 antiserum with the virus. The results suggest that an antigen related to an MuMTV envelope component is expressed in breast cancer.
Radioimmunoassay for infectious primate retrovirus reverse transcriptase: Characterization, comparison with conventional immunologic assays and applicability to cellular extracts
Authors: Robert‐Guroff Marjorie , Kalyanaraman V. S. , Sarngadharan M. G. 
Published: February 2007

AbstractSSV reverse transcriptase (RT) was purified to homogeneity and used in a radioimmunoassay. Following iodination, the homogeneity of the protein and its identity with RT were confirmed by several criteria: (I) its molecular weight on an SDS‐polyacrylamide gel; (2) its precipitation by anti‐SSV RT but not by antisera to other SSV proteins; (3) its cross‐reactivity in RIA with antisera to other retroviral polymerases; (4) its competition in RIA by active homogeneous SSV RT but not by other purified SSV proteins; and (5) its competition in RIA by only those fractions from a poly(U)‐Sepharose column possessing SSV RT activity. Competition of the labelled probe with disrupted retroviruses of the infectious primate group showed that, while a homologous RIA detected only type‐specific enzyme determinants, it did not distinguish the various woolly‐gibbon retroviral DNA polymerases. A more broadly reactive heterologous assay utilizing an antiserum to R‐MuLV RT detected groupbut not interspecies‐specific enzyme determinants. A comparison of immunologic assays for RT showed that: (I)highly purified RT is not essential for reliable results in enzyme neutralization or enzyme binding assays; (2) the greater sensitivity of enzyme binding compared to enzyme neutralization assays is a function of the antibody, not of the antigen. Competition RIAs using extracts of virus‐infected cells showed that infectious primate retrovirus RT could be measured in a crude system and that cellular DNA polymerares α,β and γ did not compete with the labelled probe.
The binding of benzo(a)pyrene to DNA components of differing sequence complexity
Authors: Jack P. , Brookes P. 
Published: February 2007

AbstractAn examination has been made of the binding, both in vitro and in vivo of the benzo(a)pyrene (BP) adduct to DNA components of differing sequence complexity. Annealing was performed at low renaturation temperatures in the presence of high concentrations of formamide to minimize hydrocarbon‐induced depurination. BHK‐DNA was modified in vitro using a tritiated derivative of the ultimate carcinogenic metabolite of BP, 7α,8β‐di‐hydroxy‐9β,10β‐epoxy‐7,8,9, 10‐tetrahydrobenzo(a)pyrene (BPDE). Co‐renaturation of this modified DNA with [14C]‐thymidine‐labelled BHK‐DNA demonstrated that the hydrocarbon adduct did not interfere with strand annealing and showed that the BP adduct was distributed randomly throughout all DNA sequence classes. However, when the DNA of cells in culture was modified by [3H]BP, following metabolic activation, and mixed with [14C]‐thymidine‐labelled DNA, a small but reproducible difference in the renaturation of the two labels was found. This difference in renaturation profiles was not due to base‐compositional effects since a similar result was found when the alternate 14C‐label was present in guanine bases, the principal site of BP modification. The small difference in the renaturation of the two radioactive labels indicated an enrichment of the hydrocarbon on the most rapidly‐renaturing sequence components (the palindromic and highly repetitive sequences) where it amounted to between 19 and 64% increased modification.
Specific glycolipid antigen(s) in SV40‐transformed cell membranes
Authors: Ansel Sandra , Huet Christian 
Published: February 2007

AbstractA glycolipid extract was prepared from an SV40‐transformed1 hamster cell line (EH‐SV) according to the Folch partition procedure. The glycolipids from the aqueous layer were incorporated in liposomal membranes composed of lecithin/sphingomyelin/cholesterol (1:1:2 by weight). This liposomal preparation was inoculated in Syrian hamsters to raise immune sera. The sera were absorbed with trypsinized «normal» hamster cells (EH‐N) and tested on various cell lines by the indirect immunofluorescence technique. When used for staining living cells, the immune serum produced a distinct cellsurface fluorescence with SV40‐transformed cell lines regardless of the cell origin (e.g., rat or hamster). No reaction was observed with heterologous Py‐transformed cell lines, spontaneously transformed cells, or sera from non‐immunized hamsters. When used for staining acetone‐fixed cells, the antiglycolipid serum reacted specifically with a thermostable antigen in the nuclear envelope and the cytoplasm of SV40‐transformed cells. The sera lack interfering SV40 T reactivity. The results indicate the presence of related SV40‐specific glycolipid antigen(s) in the plasma membrane, the nuclear membrane and probably other endomembranes of SV40‐transformed cells.
Role of elevated temperature in malignant transformation of mammalian cells in vztro
Authors: Marczynska Barbara , Bergholz Carolyn M. , Wolfe Lauren G. 
Published: February 2007

AbstractRat embryo cells subjected in vitro to transient incubation at an elevated temperature (39° C) became transformed and induced fibrosarcomas in both homologous and heterologous hosts. Malignant transformation correlated with the occurrence of karyotypic changes which appeared long after incubation at 39° C and subsequent return to 37° C. Control cultures incubated at only 37° C did not show similar chromosomal changes or induce tumors and remained predominantly diploid during the same observation period. In contrast to rat embryo cells, marmoset monkey cell cultures incubated at 39° C did not develop characteristics of transformed cells.
Dissociation of anchorage independence from tumorigenicity in human cell hybrids
Authors: Stanbridge Eric J. , Wilkinson Joyce 
Published: February 2007

AbstractThe association between anchorage independence and tumorigenicity was examined using a series of intraspecific human cell hybrids. The cell lines represented non‐tumorigenic HeLa/fibroblast hybrids and tumorigenic segregants derived from them. These segregants had lost no more than 5% of the original chromosome complement. Both non‐tumorigenic and tumorigenic cell populations formed colonies in methyl cellulose. The relative size of the colonies seemed to be inherited as a stable trait. Serial cloning of nontumorigenic hybrids in methyl cellulose led to an enhanced efficiency of colony formation but no selection for tumoregenic segregants. Thus, the property of anchorage independence is clearly dissociated from tumorigenicity in this human cell system. An ancillary observation was the chromosomal stability of the hybrids over many population doublings. This intraspecific human cell model therefore provides a genotypically and phenotypically stable system for examination of the genetic control of transformation and neoplasia.
Female sex steroid receptor status in primary and metastatic breast carcinoma and its relationship to serum steroid and peptide hormone levels
Authors: Vihko R. , Jänne O. , Kontula K. , Syrjälä P. 
Published: February 2007

AbstractIn order to obtain more information on the interrelationships between cytosol estrogen (ER) and progestin (PR) receptors in breast carcinoma, and their distribution according to age, menopausal status and endocrine parameters of the patients, these receptors were measured in 605 primary and 150 metastatic lesions, and correlated with serum levels of estradiol, progesterone, FSH, LH and prolactin in some of these patients. Measurable estrogen receptor (> 3 fmol/mg cytosol protein) was found in 78.0% and progestin receptor (> 10 fmol/mg cytosol protein) in 60.5% of all the samples studied. The receptors were simultaneously present in 57.2%, estrogen receptor only in 20.8%, progestin receptor only in 3.3%, while both receptors were absent in 18.7% of the whole material. In samples from 253 premenopausal patients, measurable ER was found less frequently (71.1% of cases) and its concentration was lower (39.9 ± 5.1 fmol/mg cytosol protein, mean ± SEM) than in 502 postmenopausal patients (82%; 148.2 ± 11.6 fmol/mg). The frequencies of ER‐positive samples and ER concentration were rather similar in primary and metastatic lesions, whereas PR was more often present (64 versus 47%) and its concentrations significantly higher (151.2 ± 12.5 versus 102.6 ± 21.1 fmol/mg) in primary than in metastatic tumors. When present simultaneously, there was a significant correlation between ER and PR concentrations in both primary and metastatic lesions independent of the menopausal status of the patient. ER concentration correlated significantly with age in both pre‐ and postmenopausal patients, while PR concentration correlated with age only in postmenopausal patients. The group with the highest ER values (above 100 fmol/mg cytosol protein) had a significantly lower serum estradiol concentration that the other patients. Serum estradiol values had a significantly positive correlation with cytosol PR content in the samples with a measurable PR. Serum progesterone, FSH, LH and prolactin did not correlate with tumor ER or PR concentrations. We conclude that concomitant assays of ER and PR from a breast carcinoma specimen provide a correct picture of the endocrine characteristics of the tumor independently of the serum concentrations of estradiol, progesterone, FSH, LH and prolactin.
The significance of 5′‐nucleotide phosphodiesterase isozymes in the diagnosis of liver carcinoma
Authors: Lu H. M. , Chen C. , Sze P. C. , Ming T. H. , Chiang K. L. , Ting C. R. , Pan L. X. , Liu T. Y. , Yiu C. 
Published: February 2007

AbstractThe results of determination of the serum 5′‐NPDase isozymes in 95 cases of primary liver carcinoma and other kinds of liver disase are presented. The 5′‐NPDase‐V was positive in 83.2% of primary liver cancer cases. This test might be a useful supplement to AFP determination, especially in AFP‐negative liver cancer patients. In most patients who had undergone successful liver resection for primary carconoma, the test became negative. A positive 5′‐NPDase‐V test in patients with cancers elsewhere in the body may suggest liver metastasis. In addition, this test may be of some help in the differentiation of primary liver cancer from other kinds of liver disease. The problem of “false‐positive” results of this test is discussed.
Increase in S‐adenosyl‐L‐methionine decarboxylase activity during the transformation of chick embryo fibroblasts by rous sarcoma virus
Authors: Bachrach Uriel , Wiener Haviva 
Published: February 2007

AbstractThe increase in S‐adenosyl‐L‐methionine decarboxylase activity in chick embryo fibroblasts after infection with Rous sarcoma virus has been studied. It has been shown that enzyme levels in transformed cells were two or three times higher than those of the non‐infected controls. The activity of this enzyme was not elevated in chick embryo fibroblasts infected with a temperaturesensitive mutant of Rous sarcoma virus (RSV‐T5) at 42°C, the non‐permissive temperature. When the temperature of these infected cultures was shifted from 42°C to 37°C a two‐ or three‐fold increase in decarboxylase activity was detected after 10 to 12 h. The half‐live of Sadenosyl‐L‐methionine decarboxylase was practically identical in normal and RSV‐transformed fibroblasts.
Adenovirus type‐12 tumor antigen. III. Tumorigenicity and immune response to syngeneic rat cells transformed with virions and isolated transforming fragment of adenovirus 12 DNA
Authors: Raška Karel , Morrongiello Mary Pat , Föring Bernd 
Published: February 2007

AbstractTumorigenicity and immunogenicity of two adenovirus 12 (Ad 12)‐transformed cell lines was studied in syngeneic LIS rats. One cell line (RT2), transformed with Ad 12 virions, contains most of the Ad 12 genome and transcribes its E1, E3 and E4 regions. The other line (RFC1) was transformed with isolated EcoRI‐C fragment of Ad 12 DNA. Both cell lines are equally tumorigenic in newborn rats; in weanling and mature animals the virion‐transformed cells are more tumorigenic as determined by the number of cells required to induce tumors in 50% of animals (TPD50) and by the proportion of “takes” after transplantation of tumor fragments. Serological analysis indicates that antibodies reactive with Ad 12 T‐antigen (product of the E1 region of Ad 12) appear later than those reactive to other Ad 12 antigen(s) present in RT2 cells. The “early” RT2 antibodies are non‐reactive with RFC1 cells. Sera of RT2 tumorbearing rats become reactive with RFC1, cells and isolated Ad 12 T‐antigen after a period of 1–4 weeks. The sera of RFC1 tumor‐bearing rats become reactive with transformed cells after a similar period. The RFC1 sera and the “late” RT2 sera are cytotoxic to both RFC1 and RT2 cells. None of the immunoreactive sera of tumor‐bearing rats are active in antibody‐dependent cellular cytotoxicity (ADCC). The spleen cells of rats bearing RFC1, tumors were cytotoxic to both RFC1 and RT2 cells. The spleen cells of animals with RT2 cell tumors, however, did not exert any cytotoxicity against either cell line. When the spleen cells of tumor‐bearing rats were further educated by incubation with transformed cells in vitro, significant cytotoxicity was observed. The spleen cells of rats bearing RFC1 tumors were equally stimulated in vitro with RFC1 and RT2 cells. The cells of rats bearing RT2 tumors were cytolytic after in vitro exposure to RFC1, cells; much less cytotoxicity was observed with cells restimulated in vitro with RT2 cells. The RFC1 and “late” RT2 sera effectively blocked the cytolysis of both RFC1 and RT2 cells. The “early” RT2 antibodies blocked the cellular cytotoxicity against RT2 cells but not RFC1 cells. Interestingly, the blocking effect was observed even with the effector cells primed in vivo and educated in vitro with only RFC1 cells. These results demonstrate that the E1 gene block of Ad 12 codes for a membrane‐associated antigen active in both humoral and cellular immunity.
Induction of immune reaction against rat embryonal carcinoma by activation of viral genome
Authors: Sobis H. , Van Hove L. , Heremans H. , De Ley M. , Billiau A. , Vandeputte M. 
Published: February 2007

AbstractA cell line (F3/I) derived from a rat embryonal carcinoma, originally induced in fetectomized rats injected with MSV, was found to be essentially non‐immunogenic in a syngeneic host; the cells did not produce C‐type virions. The MSV genome could be rescued by superinfection of F3/I cells with endogenous C‐type mouse virus and the cells were converted in a producer line‐F3/l‐P. The produced virus was shown to be MSV by its ability to induce focus formation in mouse fibroblasts. In contrast to its non‐producer ancestor, the F3/ I‐P line proved to be strongly immunogenic in the syngeneic host. These results indicate the possibility of converting certain non‐immunogenic tumors into immunogenic ones by the activation of dormant viral genome using xenogeneic non‐oncogenic helper virus.
Time course of C‐type retrovirus expression in mice submitted to osteosarcomagenic doses of 224radium
Authors: Erfle V. , Hehlmann R. , Schetters H. , Meier A. , Luz A. 
Published: February 2007

AbstractVirus particles with the biochemical properties of C‐type retroviruses appeared transiently in bone tissues of (C3H X IOI)F1 hybrid mice early after treatment with 224Radium; such particles were then again detected in the bones of the irradiated animals at the onset of osteosarcoma formation and in the osteosarcomas. Antibodies against a murine retrovirus isolated from a 224Ratinduced osteosarcoma were produced and detected in the serum of the 224Ra‐treated animals within a month after treatment began. The antibody levels plateaued to a maximum after about 2 months and remained elevated until the tumors started to develop. The antibody concentration in the serum of these irradiated animals decreased then progressively to reach levels similar to those observed in untreated controls. It thus appears that the imminence of osteosarcoma development can be predicted by monitoring the anti‐C‐type virus antibody levels in the serum of the irradiated mice. These experiments also strongly suggest that treatment with 224Radium induces expression of endogenous viruses in the animals.
Epstein‐Barr virus‐specific antibody titers in seven Alaskan Natives before and after diagnosis of nasopharyngeal carcinoma
Authors: Lanier Anne P. , Henle Werner , Bender Thomas R. , Henle Gertrude , Talbot Marion L. 
Published: February 2007

AbstractResults are presented of Epstein‐Barr virus‐specific serologic tests for seven Alaskan Native patients with nasopharyngeal carcinoma (NPC) from whom serum had been collected 2–10 years before diagnosis and up to 6 years after diagnosis. The pre‐illness antibody spectra and titers of the NPC patients did not differ from those of controls. However, broadened antibody spectra and elevated titers were associated with the emergence of NPC disease, which in one case was present as early as 22 months before actual diagnosis. Increasing or continuously high antibody titers were associated with progression of the disease and death, whereas patients who maintained relatively low, stable antibody titers after treatment have remained well.
Glucocorticoid receptors and glucocorticoid sensitivity of human leukemic cells
Authors: Kontula K. , Andersson L. C. , Paavonen T. , Myllylä G. , Teerenhovi L. , Vuopio P. 
Published: February 2007

AbstractWe have established optimal conditions for the measurement of glucocorticoid receptors (GR) in human white cells using a whole‐cell binding assay with [3H]dexamethasone as the ligand, and the subsequent determination of the GR content in normal human lymphocytes and in leukemic cells of patients with various forms of acute and chronic leukemia. A number of leukemic cell lines in continuous culture were also subjected to the GR assay, and the results were correlated with the sensitivity of these cell lines to glucocorticoid steroids in vitro. The GR content of normal human lymphocytes amounted to 4,850 ± 1,340 (mean ± sd) receptors/cell. The mean equilibrium dissociation constant (KD) of the interaction of [3H]dexamethasone with the GR was 1.2 × 10−8M. Steroidal compounds with a known glucocorticoid potency effectively competed for the binding, whereas steroids devoid of glucocorticoid activity (e.g. estradiol‐17β and testosterone) were ineffective. The GR content of the blast cells obtained from eight patients suffering from acute leukemia and four patients with a blast crisis of chronic myelocytic leukemia was found to be highly variable (3,230–29,900 receptors/cell), while the lymphocytes of six patients with chronic lymphatic leukemia contained a rather stable GR content (2,930–5,120 receptors/cell), which was comparable with that of normal lymphocytes. GR was identified in all the 12 malignant continuous white cell lines studied. Large cells contained more GR than the smaller ones. There was no apparent correlation between the GR concentration and the sensitivity of the cells in vitro to glucocorticoids as judged by [3H]thymidine incorporation studies. Distribution of the surface markers in the leukemic cell lines did not relate to the GR concentration. We conclude that the presence of GR is probably a universal feature of the leukemic cells, and, from a clinical standpoint, probably does not alone imply steroid responsiveness.