bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of feline xenotropic RNA tumor virus in hybrids between permissive human and non‐permissive mouse cells
Authors: Edgell Cora‐Jean S. , Gazdar Adi F. , Minna John D. 
Published: February 2007

AbstractSomatic cell hybrids were generated by fusing human (A549) cells, cloned after infection with the feline xenotropic CCC virus, to mouse (3T3) cells which are non‐permissive for this virus. Hybrid clones were found to be capable of expressing infectious virus. CCC virus expression, however, was regulated in the hybrid cells in such a way that 20–200 times less virus was released into the culture fluid than by the human parental line. Thus human permissiveness for this virus is co‐expressed with murine restriction. Markers for twenty human chromosomes were assayed in the hybrid clones. No single human chromosome was found to be essential and sufficient for CCC virus production, since none of them was consistently present or lost in virus‐positive and virus‐negative clones, respectively.
Betel quid chewing and oral cancer: Experimental studies on hamsters
Authors: Ranadive Kamal J. , Ranadive S. N. , Shivapurkar N. M. , Gothoskar S. V. 
Published: February 2007

AbstractBetel quid ingredients — betel nut, betel leaf, lime, catechu and tobacco — were tested separately and in various combinations for carcinogenicity, using hamster cheek pouch as the experimental site. The four modes of administration used were (1) triweekly painting of the cheek pouch with aqueous extracts of test materials, (2) deposition of replaceable wax pellets containing the test material, (3) gelatin capsules containing the powdered material and (4) insertion of natural material into the pouch for trauma and direct exposure. Untreated controls and standard carcinogen DMBA‐treated controls were also maintained. A total of 317 young adult golden Syrian hamsters (Mesocricetus auratus) used for the experiments were killed in two age groups: 6–12 months and 13–24 months, only when signs of general debility were observed. In the untreated controls, animals were free of any malignancy. In the experimental series, various betel quid ingredient combinations under test induced both oral and gastric lesions ranging from massive atypia and precancerous lesions to frank carcinomas. Maximum lesions were observed in the groups receiving betel nut, lime and tobacco combinations and in the polyphenol fraction of betel nut containing major tannins. The mode of administration of test material resulted in distinct differences; tri‐weekly paintings giving oral lesions in the range of 22–23% and gastric lesions 39–48%; the same material given either through the replaceable gelatin capsule or in natural form induced 69% oral lesions and 63 to 82% gastric lesions. Overall evaluation of the data of all the four series confirms the potent carcinogenicity of betel nut, particularly its tannin‐containing polyphenolic fraction and its combination with lime and tobacco. Maximum oral lesions induced in the hamsters by continuous exposure to capsules and natural material, highlight the direct relationship of frequency of chewing in habitual chewers with oral carcinogenesis. The high incidence of gastric (forestomach) lesions invites special attention.
Cervical carcinoma: Detection of herpes simplex virus RNA in cells undergoing neoplastic change
Authors: McDougall James K. , Galloway Denise A. , Fenoglio Cecilia M. 
Published: February 2007

Abstract3H‐HSV‐2 DNA has been hybridized in situ to frozen sectioned tissue from human cervical biopsies. RNA complementary to the virus‐specific probe was detected in cells undergoing pre‐malignant changes, but not in the cells of the fully developed squamous‐cell cancer.
Association of depressed postoperative lymphoproliferative responses to alloantigens with poor prognosis in patients with stage I lung cancer
Authors: Cannon G. B. , Dean J. H. , Herberman R. B. , Perlin E. , Reid J. , Miller C. , Lang N. P. 
Published: February 2007

AbstractThirty‐five patients with Stage I carcinoma of the lung were tested postoperatively to assess lympho‐proliferative responses. Depressed lymphocyte proliferation (LP) responses to alloantigen in the mixed leukocyte culture (MLC) as measured by the relative proliferation index (RPI) were associated with a significantly shorter disease‐free interval. In this group of patients, the immunologic responses predicted subsequent clinical course better than the TNM classification or the his‐tological type of the tumor, and therefore this procedure appears promising for improved staging of patients with early stages of lung cancer (stage I lung cancer and T1N0M0). The depressed response to alloantigen was a more sensitive discriminator of disease recurrence than PHA alone or even combined with PHA.
The requirement for monocytes in spontaneous cytotoxicity by lymphocytes from healthy donors and melanoma patients
Authors: de Vries Jan E. , Mendelsohn John , Bont Willy S. 
Published: February 2007

AbstractLymphocytes from 12 healthy donors were depleted of monocytes by velocity sedimentation at unit gravity (average monocyte contamination 0.2%) and tested for spontaneous cytotoxicity (SC) against tumor target cells in 24 h microcytotoxicity assays. Sixty percent of all lymphocytes were recovered in this monocyte‐de‐pleted lymphocyte fraction (LF). In contrast, with the corresponding unfractionated lymphocytes (UL) the LF cells were not spontaneously cytotoxic on T24 bladder carcinoma, NKI‐1, NKI‐7, NKI‐8, NKI‐1O melanoma, and MC‐1 mammary carcinoma cell line cells and target cells derived from two short‐term melanoma cultures (Me 215 and Me 223). SC of the LF could be restored by reconstitution with autologous monocytes, which were obtained >80% pure in the same velocity sedimentation procedure. Addition of 4–8% monocytes was sufficient to restore the SC of the LF to the level achieved with the corresponding UL, whereas maximal induction of SC was observed after addition of 8–16% monocytes. Higher numbers of monocytes had suboptimal effects. SC of the LF could also be restored by monocyte culture supernatants. The spontaneous cytotoxic effector cells were characterized as non‐E rosette‐forming, membrane slg‐negative Fc‐receptor‐bearing lymphocytes, a proportion of which probably also bear C3‐receptors. Since the LF was not spontaneously cytotoxic, in spite of the presence of Fc‐receptor bearing lymphocytes, it is concluded that monocyte help, mediated via soluble factors, is required. Evidence is presented that the lack of SC by the LF might be attributable to the failure of these cells to make appropriate contact with the target cells. LF/target cell contact followed by target cell kill occurred after addition of monocytes. Effector/target cell contacts, artificially established by agglutinins, did not result in target cell kill. Thus the effector/target cell contacts observed in the presence of monocytes suggest recognition of particular membrane determinants involved in SC.An identical requirement for monocytes was observed with LF cells from 5 stage I and 5 stage II melanoma patients tested for SC against both melanoma and non‐melanoma target cells. This indicates that either the cytotoxicity against melanoma cells with lymphocytes from melanoma patients is of the same nature as the SC of lymphocytes from healthy donors, or that specific melanoma‐associated cellular cytotoxicity also requires monocyte help.
Distribution of tumor‐associated antigen cea and cross‐reacting NCA in fetal organs
Authors: Gadler H. , Bremme K. , Wahren B. 
Published: February 2007

AbstractThe organ distribution of the tumor‐associated car‐cinoembryonic antigen (CEA), and that of the normal tissue component NCA (non‐specific cross‐reacting antigen) have been investigated in the fetus. Organ extracts from five fetuses between 14 and 21 weeks of age were analysed by radioimmunoassay using specific antisera. CEA was detected in large amounts (800‐1,650 ng/g) in fetal colon and in barely detectable amounts in lung and placental tissue. This differed from NCA, which could be detected in almost all organ extracts analysed. The highest concentration of NCA was measured in fetal colon and the content increased with the gestational age of the fetus. High amounts of NCA were also found in the liver, spleen and placenta! tissue. The gel elution profiles of CEA and NCA from an amniotic fluid pool and a pool of colonic extracts were also determined. CEA eluted similarly to the marker 125I‐CEA purified from liver metastasis of colonic carcinoma. The NCA‐reactive material was found in three distinct peaks.
Separation of the tumor‐associated transplantation antigen (TATA) from the alien H‐2k antigens expressed on a methylcholanthrene‐induced tumor
Authors: Rogers Michael J. , Law Lloyd W. , Pierotti Macro , Parmiant Giorgio 
Published: February 2007

AbstractThe tumor‐associated transplantation antigen (TATA), alien H‐2k antigens and normal H‐2d antigens expressed on a methylcholanthrene‐induced tumor were monitored during gel filtration and lectin affinity chromatography of detergent‐solubilized tumor‐cell membranes. TATA was resolved from both the normal and alien H‐2 antigens by these techniques. The relationship between histocompatibility antigens and TATA is discussed.
Suppression of friend leukemia virus by bacillus calmette‐guérin and a streptococcal preparation, OK‐432
Authors: Tsuruo Takashi , Iida Harumi , Tsukagoshi Shigeru , Sakurai Yoshio 
Published: February 2007

AbstractOK‐432, a streptococcal preparation, and BCG effectively inhibited splenomegaly in Friend leukemia virus (FLV)‐infected mice. Divided drug dosage resulted in stronger inhibition than single administration. When the second dose was fixed at the 3rd pre‐infection day, the best timing for the first dose was approximately 30 days before infection. The optimal dosages were 100–600 KE/kg for OK‐432 and 25–100 mg/kg for BCG. Transfer of peritoneal exudate cells (PEC) from immunomodulator‐treated mice, but not PEC from untreated mice, conferred resistance against FLV which was highest when PEC were transferred I day before FLV infection. The transfer of PEC on the day of or one day after infection had no protective effect. Inactivation also occurred when FLV was incubated in the presence of PEC from immunomodulator‐treated mice, however, no significant effect was observed for PEC from untreated mice.
Resistant hepatocytes as early changes in liver induced by polycyclic aromatic hydrocarbons
Authors: Tsuda Hiroyuki , Farber Emmanuel 
Published: February 2007

AbstractInduction of putative preneoplastic hepatocytes which are resistant to cytotoxic effect of 2‐acetylamino‐fluorene (2‐AAF) by five carcinogenic polycyclic aromatic hydrocarbons (PAH) was tested using γ‐glutamyl transpeptidase (γ‐GT) as a histochemical marker enzyme. Bgenzo (a) pyrene [B(a)P], 7,12‐dimethylbenz(a) anthracene (7,12‐DMBA), 3‐methylcholanthrene (3‐MC), dibenz (a, h)‐anthracene [DB(a, h)A] and benzo (a) anthracene [B(a)A] were given 12 h after partial hepatectomy (PH) followed by 2‐AAF and carbon tetrachloride (CCI4) feeding, a procedure developed by this laboratory. All of the five PAHs induced a significantly increased number of γ‐GT positive foci when compared with sham‐hepatectomized (SH) or vehicle control groups. The numbers of γ‐GT‐positive foci induced by B(a)P, 7,12‐DMBA, 3‐MC and DB (a, h)A were significantly different from all of the parent compounds, anthracene, naphthalene, pyrene and phenanthrene. B(a)A did not induce significantly increased number of foci only when compared to anthracene. Possible usefulness of this system for in vivo short‐term assay is discussed.
Bovine leukemia virus‐specific antibodies in french cattle. III. Prevalence of the BLV‐gp 51 radioimmunoassay for the detection of BLV‐infected animals
Authors: Levy D. , Deshayes L. , Parodi A. L. , Levy J. P. 
Published: February 2007

AbstractThe control of the spread of BLV infection among cattle requires very sensitive methods of detection. The BLV‐gp5I radioimmunossay presents great advantages over the other serological methods, including the BLV‐p24 radioimmunoassay. This is clear from studies of normal animals from the high‐leukemia‐incidence region which show that anti‐gp5I antibodies reach higher titers than anti‐p24 or may even exist alone. Moreover, a sequential survey reveals that the anti‐gp antibodies appear earlier. On the other hand, it was not possible to detect a viral antigen expression in the tissues of the infected animals.
Cytotoxic effector cells with the characteristics of natural killer cells in the lungs of mice
Authors: Puccetti Paolo , Santoni Angela , Riccardi Carlo , Herberman Ronald B. 
Published: February 2007

AbstractCells with in vitro cytotoxicity against tumor targets in a short‐term 51Cr release assay have been recovered from the lungs of mice that were either untreated or injected with biological or synthetic agents 1–3 days earlier. The cytotoxic effector cells were non‐adherent, non‐phagocytic and shared many characteristics with splenic natural killer (NK) cells. This finding is discussed with particular regard to our previous observations on the rapid in vivo elimination from the lungs of intravenously injected, radiolabelled tumor cells.
Characterization of lymphocyte subsets in spontaneous mouse mammary tumors and host lymphoid organs
Authors: Santer V. , Mastromarino J. H. , Lala P. K. 
Published: February 2007

AbstractThe subsets of small lymphocytes (surface lgm‐positive or B, Thy‐I‐positive or T and «double‐negative» or null) appearing within spontaneous mammary tumors of C3H retired breeder female mice and in various lymphoid organs of the host at different stages of tumor development were characterized directly using a radioautographic method. Tumor‐bearing mice showed early transient splenomegaly and progressive atrophy of the thymus. The proportion of T small lymphocytes increased with tumor age within the tumor and in the spleen, blood and thymus; then, except in the spleen, these proportions declined again by 8 weeks of tumor growth. The incidence of B small lymphocytes showed no change in the tumor or thymus; there was an increase in the blood after 3 weeks, and a small decrease in the spleen after 7 weeks. At all the sites examined, the proportion of null small lymphocytes declined from an initial high level observed in the elderly tumor‐free control mice, and then recovered to control levels after 7 weeks. The absolute numbers of T and null cells in the spleen changed in parallel to their proportions, while splenic B‐cell numbers increased at 1–3 weeks. In the thymus the absolute numbers of all subsets decreased, with a late recovery of null cell numbers. Age‐matched control mice showed higher proportions of null cells in the spleen, blood and thymus, and lower proportions of T cells in the blood and spleen, than did young normal mice. This spontaneous tumor appears to be characterized by an increase in T cells, rather than in null cells, as observed for rapidly growing transplanted tumors. The null cell rise in the present case takes place before the clinical appearance of tumors. In both cases, however, tumor‐infiltrating B cells exhibited low levels of surface Ig, possibly related to a low level of maturation. The functional significance of these findings remains to be determined.
Tumour‐related changes in natural killer cell activity in melanoma patients. Influence of stage of disease, tumour thickness and age of patients
Authors: Hersey P. , Edwards Anne , McCarthy W. H. 
Published: February 2007

AbstractThe influence of tumour growth on the natural killer (NK) activity of melanoma patients was examined by analysis of NK activity in 51 Cr release assays before and at intervals after surgical removal of localized melanoma. In patients with Stage I and II melanoma, removal of the tumour was associated with changes in the level of NK activity which were not detected in patients who had surgery for skin graft after previous removal of the primary melanoma. The changes in NK activity after removal of melanoma were however different in patients with Stage I compared to Stage II melanoma. In the former, NK activity which appeared specifically directed toward melanoma cells was maximal 2–4 weeks after removal of the tumour and then decreased to normal levels. The NK activity after surgery was directly related to the thickness of the tumour. In patients with Stage II melanoma, NK activity did not increase but fell to low levels after removal of the tumour. The level of NK activity in these patients was not related to the thickness of their primary melanoma. In patients with Stage I and II melanoma the NK activity against melanoma cells showed a significant increase with age. The reason for the different sequence of changes in NK activity after removal of melanoma in the two patient groups is unknown. It is suggested however that the differences observed in patients with Stage II melanoma may reflect differences in the tumour or host response which contributed to the spread of the tumour to regional lymph nodes in these patients.
Induction of morphological and functional differentiation of human promyelocytic leukemia cells (HL‐60) by compounds which induce differentiation of murine leukemia cells
Authors: Collins S. J. , Bodner A. , Ting R. , Gallo R. C. 
Published: February 2007

AbstractVarious compounds active in promoting in vitro differentiation of certain murine leukemia cell lines (Friend erythroleukemia cells and mouse myeloid leukemia cells) were tested for their capacity to induce differentiation of HL‐60 cells, a human promyelocytic leukemia cell line capable of terminally differentiating in vitro to functionally mature granulocytes. Polar planar compounds including hexamethylene bisacetamide (HMBA), certain purines (particularly hypoxanthine), and actinomycin‐D induced morphological and functional (as assessed by the capacity to reduce NBT dye) differentiation of HL‐60. In contrast, hemin, ouabain, prostaglandin E1, X‐irradiation, dexamethasone and some other anti‐leukemic chemotherapeutic agents induced little if any significant differentiation of HL‐60 cells. These results, together with previous observations with murine leukemia cells, suggest that the human HL‐60 cells share common cellular target sites for the inducing action of polar planar compounds, hypoxanthine and actinomycin‐D with some murine leukemic cells. In contrast, hemin, ouabain and prostaglandin E, may be specific for mouse erythroleukemia cells, while X‐irradiation and chemotherapeutic agents induce differentiation of both types (erythroid and myeloid) of mouse leukemic cells, but have little effect on HL‐60 cells.
Evaluation of the humoral response of glioma patients to a possible common tumor‐associated antigen(S)
Authors: Martin‐Achard Alec , Diserens Annie‐Claire , de Tribolet Nicolas , Carrel Stefan 
Published: February 2007

AbstractCytotoxic antibodies against glioblastoma‐associated antigen(s) have been sought for in glioma patient sera. Complement‐dependent cytotoxicity (CDC) and antibody‐dependent cell‐mediated cytotoxicity (ADCC) assays were used to test sera from 80 patients using 51Cr labelled target cells derived from eight different glioblastoma lines. As more positive sera were detected with ADCC than with CDC, ADCC assay was used for the remainder of the study. Cytotoxic antibodies were detected in the sera from 8 of 80 glioma patients (10%) by CDC and in 20 of 143 (14%) by ADCC. Fourteen per cent of 27 meningioma patients and 16% of 25 normal donors used as controls were found to react in ADCC against the same glioblastoma cell lines. The positive serum samples showed extensive cross‐reactions with the different glioblastoma cells, but the pattern of reactivity was different for each serum tested. The antibodies detected did not seem to be directed against tumor‐associated antigen(s), since the positive sera were found to have a similar ADCC reactivity against unrelated tumor cells and normal fibroblasts. Moreover, their antiglioma reactivity was absorbed by cells of unrelated tumors and by normal platelets. These results do not support previous reports of specific humoral responses in glioma patients against common tumor‐associated antigen(s).
The generation of tumor heterogeneity in vivo
Authors: Chow D. A. , Greenberg A. H. 
Published: February 2007

AbstractIn order to determine whether host factors may contribute to the generation of tumor heterogeneity, the phenotypic stability of cells from a cloned tumor was examined during proliferation in tissue culture and in the syngeneic host. Growth of this cloned tumor was initiated both in vivo and in vitro, and the tumor populations were sampled at different time intervals by subcloning. The susceptibility of these tumor subclones to the cytotoxic action of natural antibodies and complement was used as a marker of their membrane phenotype. The extent of phenotypic variation of the clones in one sample was considered to be a measure of tumor heterogeneity. Following these procedures, we observed that a clone of the L5178Y murine lymphoma maintained its homogeneity during 5 months of in vitro culture. In contrast, a single passage of the same tumor clone for 31/2 weeks or 3 months in the syngeneic host resulted in the generation of a population of cells exhibiting a significant increase in heterogeneity. This relative instability of tumor phenotype in vivo suggests that the host milieu may allow the generation of tumor heterogeneity. Genetic or epigenetic mechanism(s) may be involved although the high frequency of new phenotypes argues against a role for somatic mutation.
Metabolism of benzo[a]pyrene by cultured tracheobronchial tissues from mice, rats, hamsters, bovines and humans
Authors: Autrup Herman , Wefald Franklin C. , Jeffrey Alan M. , Tate Hussein , Schwartz Rochelle D. , Trump Benjamin F. , Harris Curtis C. 
Published: February 2007

AbstractThe metabolism of benzo[a]pyrene (BP)4by cultured tracheobronchial tissues from different species ‐ human, bovine, hamster, rat and mouse ‐ has been investigated. The total metabolism, as measured by both organic solvent‐extractable and water‐soluble metabolites of BP, was substantial in the respiratory tract from humans and from animal species susceptible to the carcinogenic action of BP. The ratio of organic‐extractable metabolites to water‐soluble metabolites was greater than one in hamster, human and C57BI/6N mouse, but less than one in rat, bovine and DBA/2N mouse, suggesting that determination of both activation and deactivation pathways are important in assessing carcinogenic risk of a chemical. Sulphate esters and glutathione conjugates were the major water‐soluble metabolites in all animal species; tetrols and diols were the major organic extractable metabolites. The level of trans‐7,8‐dihydro‐7,8‐dihydroxybenzo[a]pyrene, the proximate carcinogenic form of BP, was three times higher in C57BI/6N than in DBA/2N mouse trachea. Trans‐9,10‐dihydro‐9,10‐dihydroxybenzo[a]pyrene was the major metabolite formed by cultured hamster trachea. The binding levels of BP to cellular DNA were quite similar in all tissues, although slightly higher binding was observed in hamster trachea. Wide inter‐individual variation in the binding of BP to DNA was seen in tissues from outbred species. The major BP‐DNA adducts in all animal species were formed by interaction of benzo[a]pyrene diol‐epoxide with the 2‐amino group of deoxyguanosine. Both stereoisomeric forms of (±)‐(7β,8α)‐dihydroxy‐(9α, 10α)‐epoxy‐7,8,9,10‐tetrahydro‐benzo[a]pyrene (BPDE I) reacted with deoxyguanosine, the (7R)‐form being the most reactive. No difference in the relative distribution of the various adducts was seen between the species except in the CD rat, where BPDE‐deoxyadenosine adducts accounted for 20% of the total modification. In cultured hamster trachea the persistence of the different adducts was similar. In conclusion, the metabolism of BP is qualitatively similar in tracheobronchial tissues from both humans and animal species in which BP has been experimentally shown to be carcinogenic.