Sample records for benzanthracene

  1. 40 CFR Appendix II to Part 258 - List of Hazardous Inorganic and Organic Constituents


    ... Barium (Total) Barium Benzene 71-43-2 Benzene Benzo anthracene; Benzanthracene 56-55-3 Benz anthracene...-Dichloropropane 78-87-5 Propane, 1,2-dichloro- 1,3-Dichloropropane; Trimethylene dichloride 142-28-9 Propane,...

  2. Inhibitory effect of vitamin D-binding protein-derived macrophage activating factor on DMBA-induced hamster cheek pouch carcinogenesis and its derived carcinoma cell line

    TOYOHARA, YUKIYO; HASHITANI, SUSUMU; Kishimoto, Hiromitsu; Noguchi, Kazuma; Yamamoto, Nobuto; Urade, Masahiro


    This study investigated the inhibitory effect of vitamin D-binding protein-derived macrophage-activating factor (GcMAF) on carcinogenesis and tumor growth, using a 9,10-dimethyl-1,2-benzanthracene (DMBA)-induced hamster cheek pouch carcinogenesis model, as well as the cytocidal effect of activated macrophages against HCPC-1, a cell line established from DMBA-induced cheek pouch carcinoma. DMBA application induced squamous cell carcinoma in all 15 hamsters of the control group at approximately...

  3. Usefulness of a Technique Based on Negative Corona Discharge for the Degradation of Selected, Condensed PAHs: Application to the Oxidation of Anthracene and Similar Structures

    Tessier, D.; OGUIC, C.; PINART, J.


    The usefulness of negative corona discharge for oxidation of condensed polycyclic aromatic hydrocarbons (PAHs), including anthracene, naphthalene and 2,3-benzanthracene, adsorbed on a solid substrate is evaluated. In the case of anthracene, the application of corona discharge under high voltage (10-20 kV) for 10 to 180 min with a current intensity of 5-120 m A in a controlled, humid atmosphere leads to the progressive formation of anthraquinone. A kinetic study of the anthracene o...

  4. Distribution of hydrocarbon-utilizing microorganisms and hydrocarbon biodegradation potentials in Alaskan continental shelf areas

    Hydrocarbon-utilizing microogranisms were enumerated from Alaskan continental shelf areas by using plate counts and a new most-probable-number procedure based on mineralization of 14C-labeled hydrocarbons. Hydrocarbon utilizers were ubiquitously distributed, with no significant overall concentration differences between sampling regions or between surface water and sediment samples. There were, however, significant seasonal differences in numbers of hydrocarbon utilizers. Distribution of hydrocarbon utilizers within Cook Inlet was positively correlated with occurrence of hydrocarbons in the environment. Hydrocarbon biodegradation potentials were measured by using 14C-radiolabeled hydrocarbon-spiked crude oil. There was no significant correlation between numbers of hydrocarbon utilizers and hydrocarbon biodegradation potentials. The biodegradation potentials showed large seasonal variations in the Beaufort Sea, probably due to seasonal depletion of available nutrients. Non-nutrient-limited biodegradation potentials followed the order hexadecane > naphthalene >> pristane > benzanthracene. In Cook Inlet, biodegradation potentials for hexadecane and naphthalene were dependent on availability of inorganic nutrients. Biodegradation potentials for pristane and benzanthracene were restricted, probably by resistance to attack by available enzymes in the indigenous population

  5. TEM characterization of organic nanocrystals grown in sol-gel thin films

    The tetracene molecule (2,3-benzanthracene, C8H12) was used to synthesize nanocrystals grown in sol-gel thin films, ranging from 10 to 100 nm of diameter. This confined nucleation and growth was compared to microcrystallizations of the same molecule in free solution. Transmission electron microscopy (TEM) was used to characterize these two kinds of tetracene crystals. The observation was performed under low-dose illumination to avoid amorphization of the samples during electron irradiation. Spatial confinement and size distribution of micro- and nanocrystals were compared. Using electron microdiffraction and diffraction patterns simulations, we showed that free microcrystals and nanocrystals confined in gel glasses exhibit the same triclinic P-bar 1 structure. In addition, time-resolved spectroscopy was used to record fluorescence decays, showing a monoexponential fluorescence decay for nanocrystals while microcrystals exhibit a multiexponential decay. The simple signature of nanocrystals luminescence is promising for the future development of chemical or biological sensors

  6. Epidermal cell growth-dependent arylhydrocarbon-hydroxylase (AHH) activity in vitro.

    Thiele, B; Merk, H F; Bonnekoh, B; Mahrle, G; Steigleder, G K


    Cytochrome P-450-dependent arylhydrocarbon-hydroxylase (AHH) activity and inducibility by benzanthracene (BA) was measured in cultured guinea pig and human epidermal cells. Basal AHH-activity (AHHb) in guinea pig epidermal cells was much higher than in human epidermal cells. AHHb in guinea pig epidermal cells was directly related to the labeling index and decreased to the original level between the 5th and 7th day of cell culturing. On the other hand, the induction-ratio of AHH reached its maximum level when the number of cells began to rise (proliferation phase) and remained high at day 7 of the cell culture. These results suggest a cell growth dependent activity and inducibility of carcinogen-metabolizing enzymes, such as AHH, in isolated epidermal cells. PMID:3435181



    Objective: To investigate the roles of telomerase activity (TA) in relation to hamster buccal pouch tumor progression. Methods: male hamster were treated three times weekly with 0.5% of 7, 12-dimethyl- benzanthracene (DMBA) over a 15 weeks experimental period. Hamsters were sacrificed at 3, 6, 9, 12 and 15 weeks after treatment. Telomerase activity of hamster buccal pouch tissue were measured along with the analyses of the formation of DMBA-induced hamster buccal pouch tumors. Results: DMBA-induced squamous cell carcinomas were found at the 6th week after dosing. Telomerase activity elevation began at the 3rd week and was increasing to a plateau at the 12th week. Conclusion: Our results show that telomerase activity in the target tissue may be detected at the early stage of the DMBA-induced hamster buccal pouch tumor formation and suggests that telomerase activity may be used as a biomarker for an early clinical detection of buccal pouch cancer.

  8. Magnetofullerenosome mediated near-infrared laser therapy of hamster tongue carcinoma

    This study was performed to demonstrate the usefulness of magnetofullerenosomes- a lipidic nanostructures with incorporated fullerenes C60 in their lipid bilayers and co-encapsulated photosensitizer naphthalocyanate and magnetite nanoparticles for the oral cancer combined hyperthermia and photodynamic therapy. Tumors were induced in golden hamster tongue by 9,10-dimethyl 1-1,2- benzanthracene application. Magnetofullerenosome suspension was locally injected into the tumorbearing tongue and the tongues were irradiated with near-infrared laser light leading to tumor heating, and photosensitzer release combined with its activation. The inhibition of the growth of tongue carcinoma group was significantly greater than in the control group. These results strongly suggest the usefulness of this novel multifunctional approach to the cancer therapy of oral region that is accessible to this treatment (Authors)

  9. The influence of mouse vaccination with endogenous retrovirus on the development of tumor incluced by γ-irradiation or 7,12-Dimethylbenz(a)anthrocene

    Mouse vaccination with alive endogenous N-tropic virus OA-3 inhibited and decreased the development of the Rauscher leukemia in C57B1/6 mice (B-type) and SWR mice (N-type) as well as development 7,12-dimethyl benzanthracene (DMBA) induced tumours in mouse hybrides (neither N-, nor B-types). The effect of vaccination was DMBA- or MLV-P-dose-dependent. Vaccination with the same virus did not affect the incidence of γ-irradiaton-induced leukemia in CBA mice (N-type) and C57B1/6 mice while it increased twice the incidence of radiation leukemia in DBA mice (N-type). However, the incidence of thymomas lowered in radiaton leukemia-bearing vaccinated mice of all the 3 strains, which may result from inhibition of murine thymotropic endogenous virus reproduction. The data obtained indicate the participation of murine own endogenous viruses in DMBA- or γ-irradiation induced carcinogenesis

  10. Ameliorative potential of fluoxetine/raloxifene combination on experimentally induced breast cancer.

    Kabel, Ahmed M; Elkhoely, Abeer A


    Breast cancer is one of the most common types of malignancies in females worldwide. Targeting the estrogen receptors alone with raloxifene (RAL) reduces the incidence of estrogen receptor positive tumors. Fluoxetine (FLX) is one of selective serotonin reuptake inhibitors that was proven to have anticancer properties. Our aim was to detect the effects of RAL/FLX combination on experimentally induced breast cancer. Eighty female Wistar rats were divided into four equal groups: 7,12-Dimethyl Benzanthracene (DMBA) induced breast cancer group, DMBA+RAL, DMBA+FLX and DMBA+RAL+FLX. Tumor volume, tissue malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6) and transforming growth factor beta1 (TGF-β1) were determined in the tumor tissues. Parts of the tumor were subjected to histopathological examination. RAL or FLX alone or in combination induced significant increase in tumor CAT and SOD with significant decrease in tumor volume, tissue MDA, TNF-α, IL-6 and TGF-β1 and alleviated the histopathological and immunohistochemical changes compared to DMBA group. In conclusion, RAL/FLX combination had a better effect than each of RAL or FLX alone against DMBA-induced breast cancer in rats which may represent a new therapeutic modality for management of breast cancer. PMID:26881735

  11. Effect of Withania somnifera on DMBA induced carcinogenesis.

    Davis, L; Kuttan, G


    Administration of an extract of Withania somnifera was found to reduce two stage skin carcinogenesis induced by DMBA (dimethyl benzanthracene) and croton oil. Withania somnifera was administered at a concentration of (20 mg/dose/animal i.p.) consecutively on 5 days prior to DMBA administration and continued twice weekly for 10 weeks. After the 180th day of carcinogen administration, all of the animals developed papilloma in the control group whereas only six out of 12 animals developed papilloma in the treated group. A total of 11 papillomas were found in the control group while only six developed them in the Withania somnifera treated group. Enzyme analysis of skin and liver showed significant enhancement in antioxidant enzymes such as GSH, GST, Glutathione peroxides and Catalases in Withania somnifera treated group when compared with the control. The elevated level of lipid peroxide in the control group was significantly inhibited by Withania somnifera administration. These studies indicate that Withania somnifera could reduce the papilloma induced alterations to the antioxidant defense systems. PMID:11297845

  12. Highly sensitive detection method for virus gene using radio-isotope. Development of PCR in situ hybridization method and its application

    In order to elucidate the in vivo localization of the viruses involving in carcinogenic process, development of a new method, PCR-ISH was attempted. An experimentally induced squamous cell carcinoma in lingual mucosa was used as a carcinogenic animal model. Displasia in the lingual mucosa and squamous cell carcinoma were induced by spreading DMBA (dimethyl benzanthracene) and the genus specific antigen of papillomavirus (GSAP) was immunohistochemically detected in the nucleus of the precancerous squamous cells, strongly suggesting the involvement of papillomavirus (P-virus) in the carcinogenesis. Then, the DNA extracted from the frozen tissue was analyzed by Southern blot hybridization and the detection of the virus genome in the tissue was carried out by agarose-gel electrophoresis using a primer which recognizes the specific sequence in P-virus. Thus, the presence of a new P-virus named as hamster oral P-virus (HOPV) was confirmed and the genome was detected in the lesioned tissue, but the localization of the genome in the normal mucosa has not been identified. (M.N.)

  13. Inhibitory effect of vitamin D-binding protein-derived macrophage activating factor on DMBA-induced hamster cheek pouch carcinogenesis and its derived carcinoma cell line.

    Toyohara, Yukiyo; Hashitani, Susumu; Kishimoto, Hiromitsu; Noguchi, Kazuma; Yamamoto, Nobuto; Urade, Masahiro


    This study investigated the inhibitory effect of vitamin D-binding protein-derived macrophage-activating factor (GcMAF) on carcinogenesis and tumor growth, using a 9,10-dimethyl-1,2-benzanthracene (DMBA)-induced hamster cheek pouch carcinogenesis model, as well as the cytocidal effect of activated macrophages against HCPC-1, a cell line established from DMBA-induced cheek pouch carcinoma. DMBA application induced squamous cell carcinoma in all 15 hamsters of the control group at approximately 10 weeks, and all 15 hamsters died of tumor burden within 20 weeks. By contrast, 2 out of the 14 hamsters with GcMAF administration did not develop tumors and the remaining 12 hamsters showed a significant delay of tumor development for approximately 3.5 weeks. The growth of tumors formed was significantly suppressed and none of the hamsters died within the 20 weeks during which they were observed. When GcMAF administration was stopped at the 13th week of the experiment in 4 out of the 14 hamsters in the GcMAF-treated group, tumor growth was promoted, but none of the mice died within the 20-week period. On the other hand, when GcMAF administration was commenced after the 13th week in 5 out of the 15 hamsters in the control group, tumor growth was slightly suppressed and all 15 hamsters died of tumor burden. However, the mean survival time was significantly extended. GcMAF treatment activated peritoneal macrophages in vitro and in vivo, and these activated macrophages exhibited a marked cytocidal effect on HCPC-1 cells. Furthermore, the cytocidal effect of activated macrophages was enhanced by the addition of tumor-bearing hamster serum. These findings indicated that GcMAF possesses an inhibitory effect on tumor development and growth in a DMBA-induced hamster cheek pouch carcinogenesis model. PMID:22848250

  14. Bioluminescence imaging of estrogen receptor activity during breast cancer progression.

    Vantaggiato, Cristina; Dell'Omo, Giulia; Ramachandran, Balaji; Manni, Isabella; Radaelli, Enrico; Scanziani, Eugenio; Piaggio, Giulia; Maggi, Adriana; Ciana, Paolo


    Estrogen receptors (ER) are known to play an important regulatory role in mammary gland development as well as in its neoplastic transformation. Although several studies highlighted the contribution of ER signaling in the breast transformation, little is known about the dynamics of ER state of activity during carcinogenesis due to the lack of appropriate models for measuring the extent of receptor signaling in time, in the same animal. To this aim, we have developed a reporter mouse model for the non-invasive in vivo imaging of ER activity: the ERE-Luc reporter mouse. ERE-Luc is a transgenic mouse generated with a firefly luciferase (Luc) reporter gene driven by a minimal promoter containing an estrogen responsive element (ERE). This model allows to measure receptor signaling in longitudinal studies by bioluminescence imaging (BLI). Here, we have induced sporadic mammary cancers by treating systemically ERE-Luc reporter mice with DMBA (9,10-dimethyl 1,2-benzanthracene) and measured receptor signaling by in vivo imaging in individual animals from early stage until a clinically palpable tumor appeared in the mouse breast. We showed that DMBA administration induces an increase of bioluminescence in the whole abdominal area 6 h after treatment, the signal rapidly disappears. Several weeks later, strong bioluminescence is observed in the area corresponding to the mammary glands. In vivo and ex vivo imaging analysis demonstrated that this bioluminescent signal is localized in the breast area undergoing neoplastic transformation. We conclude that this non-invasive assay is a novel relevant tool to identify the activation of the ER signaling prior the morphological detection of the neoplastic transformation. PMID:27069764

  15. Joint action of a chemical carcinogen and a neoplastic virus to induce cancer in rabbits; results of exposing epidermal cells to a carcinogenic hydrocarbon at time of infection with the Shope papilloma virus.



    Areas of rabbit skin previously rendered hyperplastic with turpentine were scarified, inoculated with the Shope papilloma virus, and covered with a dressing that contained 20-methylcholanthrene (MC) or 9:10-dimethyl-1:2-benzanthracene (9:10). The dressing was left on until healing had been well completed, a matter of 5 to 7 days. The papillomas which subsequently arose often appeared later, were fewer, and remained less vigorous than those due to the action of virus alone, but throughout several months they appeared to differ from these in no other ways. Then, more or less abruptly, the large majority became carcinomatous, frequently at several situations, whereas with few exceptions the control growths underwent no such alteration. The cancers were of the sorts ordinarily deriving, by secondary change, from epidermal cells infected with the virus. Collateral data have made plain that the hydrocarbons acted in their carcinogenic capacity to bring on the cancers. Indeed in control tests 9: 10 sometimes conferred latent neoplastic potentialities on uninoculated epidermis exposed to it while healing after scarification, a fact disclosed months later by painting these expanses with chloroform until hyperplasia occurred. Under the promoting influence of this agent papillomas formed which had the distinctive morphology of those induced by the chemical carcinogens. So strong and enduring were the effects of MC and 9:10 as to cause cancers to arise from many virus papillomas which were retrogressing after months of proliferation, that is to say under circumstances ordinarily unfavorable to malignant change. The facts justify the conclusion that the virus and the hydrocarbons acted jointly and in their carcinogenic capacities. PMID:14832395

  16. 4-nitroquinoline-1-oxide induced experimental oral carcinogenesis.

    Kanojia, Deepak; Vaidya, Milind M


    Human oral cancer is the sixth largest group of malignancies worldwide and single largest group of malignancies in the Indian subcontinent. Seventy percent of premalignant cancers appear from premalignant lesions. Only 8-10% of these lesions finally turn into malignancy. The appearance of these premalignant lesions is one distinct feature of human oral cancer. At present there is dearth of biomarkers to identify which of these lesions will turn into malignancy. Regional lymph node metastasis and locoregional recurrence are the major factors responsible for the limited survival of patients with oral cancer. Paucity of early diagnostic and prognostic markers is one of the contributory factors for higher mortality rates. Cancer is a multistep process and because of constrain in availability of human tissues from multiple stages of oral carcinogenesis including normal tissues, animal models are being widely used, aiming for the development of diagnostic and prognostic markers. A number of chemical carcinogens like coal tar, 20 methyl cholanthrene (20MC), 9,10-dimethyl-1,2-benzanthracene (DMBA) and 4-nitroquinoline-1-oxide (4NQO) have been used in experimental oral carcinogenesis. However, 4NQO is the preferred carcinogen apart from DMBA in the development of experimental oral carcinogenesis. 4NQO is a water soluble carcinogen, which induces tumors predominantly in the oral cavity. It produces all the stages of oral carcinogenesis and several lines of evidences suggest that similar histological as well as molecular changes are observed in the human system. In the present review an attempt has been made to collate the information available on mechanisms of action of 4NQO, studies carried out for the development of biomarkers and chemopreventives agents using 4NQO animal models. PMID:16448841

  17. Reduction in squamous cell carcinomas in mouse skin by dietary zinc supplementation.

    Sun, Jin; Shen, Rulong; Schrock, Morgan S; Liu, James; Pan, Xueliang; Quimby, Donald; Zanesi, Nicola; Druck, Teresa; Fong, Louise Y; Huebner, Kay


    Inadequate dietary Zn consumption increases susceptibility to esophageal and other cancers in humans and model organisms. Since Zn supplementation can prevent cancers in rodent squamous cell carcinoma (SCC) models, we were interested in determining if it could have a preventive effect in a rodent skin cancer model, as a preclinical basis for considering a role for Zn in prevention of human nonmelanoma skin cancers, the most frequent cancers in humans. We used the 7,12-dimethyl benzanthracene carcinogen/phorbol myristate acetate tumor promoter treatment method to induce skin tumors in Zn-sufficient wild-type and Fhit (human or mouse protein) knockout mice. Fhit protein expression is lost in >50% of human cancers, including skin SCCs, and Fhit-deficient mice show increased sensitivity to carcinogen induction of tumors. We hypothesized that: (1) the skin cancer burdens would be reduced by Zn supplementation; (2) Fhit(-/-) (Fhit, murine fragile histidine triad gene) mice would show increased susceptibility to skin tumor induction versus wild-type mice. 30 weeks after initiating treatment, the tumor burden was increased ~2-fold in Fhit(-/-) versus wild-type mice (16.2 versus 7.6 tumors, P < 0.001); Zn supplementation significantly reduced tumor burdens in Fhit(-/-) mice (males and females combined, 16.2 unsupplemented versus 10.3 supplemented, P = 0.001). Most importantly, the SCC burden was reduced after Zn supplementation in both strains and genders of mice, most significantly in the wild-type males (P = 0.035). Although the mechanism(s) of action of Zn supplementation in skin tumor prevention is not known in detail, the Zn-supplemented tumors showed evidence of reduced DNA damage and some cohorts showed reduced inflammation scores. The results suggest that mild Zn supplementation should be tested for prevention of skin cancer in high-risk human cohorts. PMID:27185213

  18. Chemical characterization and genotoxic potential related to boiling point for fractionally distilled SRC-I coal liquids

    Wilson, B.W.; Pelroy, R.A.; Mahlum, D.D.


    This report summarizes selected research efforts oriented toward ameliorating the genotoxic potential of direct coal liquefaction materials through modification or optimization of process conditions. The studies described were conducted to evaluate the utility of optimized distillation for coal liquids from the SRC-I process. SRC-I process solvent was distilled into 50/sup 0/F-range boiling point (bp) cuts. Analysis of amino-PAH (APAH) showed that mutagenic APAHs containing 3 or more rings were found primarily in fractions boiling above 750/sup 0/F. Three microbial tester strains were used to screen for genetically active agents in the SRC-I distillate bp cuts. Reverse mutation with the Ames tester strain TA98 demonstrated that mutagens were concentrated in the bp cuts boiling above 700/sup 0/F. For this tester strain most of the genetic activity in these distillates was attributable to chemical fractions enriched in APAH having 3 or more rings. Mutagenicity data obtained with TA98 was in good agreement with sk in carcinogenesis results from the mouse-skin initiation/promotion (in vivo) test system. The strongest response in the forward mutation assay did not occur in the most carcinogenically active fractions. Results of initiation/promotion experiments used to measure the relative potency of bp cuts as initiators of mouse skin carcinogenesis again showed that fractions boiling above 750/sup 0/F. Compounds reaching their highest concentrations in the highest boiling and most carcinogenically active cut included known carcinogens such as benzo(a)pyrene and dimethyl benzanthracene. Thus, all biomedical test results indicate that consideration should be given to conducting distillation so as to minimize, in the distillate product, the concentrations of those biologically active compounds found in cuts boiling above 700/sup 0/C.

  19. 5MeCDDO Blocks Metabolic Activation but not Progression of Breast, Intestine, and Tongue Cancers. Is Antioxidant Response Element a Prevention Target?

    Lubet, Ronald A; Townsend, Reid; Clapper, Margie L; Juliana, M Margaret; Steele, Vernon E; McCormick, David L; Grubbs, Clinton J


    The preventive efficacy of the triterpenoid 5MeCDDO was tested in two models of mammary cancer, the Min model of intestinal cancer, and a chemically induced model of head and neck cancer. In one model of mammary cancer, female Sprague-Dawley rats were administered MNU at 50 days of age, and 5MeCDDO (27 ppm) was administered in the diet beginning 5 days later for the duration of the study; 5MeCDDO was ineffective. In contrast, in a model examining initiation of mammary cancers by the procarcinogen dimethyl-benzanthracene, 5, 6-benzoflavone (500 ppm, an Ah receptor agonist) or 5MeCDDO (27 or 2.7 ppm) decreased tumor multiplicity by 90%, 80%, and 50%, respectively. This anti-initiating effect which is presumably mediated by altered metabolic activation parallels our observation that 5MeCDDO induced proteins of various antioxidant response element (ARE)-related phase II drug-metabolizing enzymes [e.g., GST Pi, AKR 7A3 (aflatoxicol), epoxide hydrolase, and quinone reductase] in the liver. 5MeCDDO tested in the 4-nitroquinoline-l-oxide (4-NQO) head and neck cancer model failed to decrease tumor incidence or invasiveness. In the Min mouse model of intestinal cancer, a high dose of 5MeCDDO (80 ppm) was weakly effective in reducing adenoma multiplicity [∼30% (P < 0.05)]; however, a lower dose was totally ineffective. These findings question whether measuring increased levels of certain ARE-related genes (e.g., quinone reductase, GST Pi), indicating decreased carcinogen activation are sufficient to imply general chemopreventive efficacy of a given agent or mixture. Cancer Prev Res; 9(7); 616-23. ©2016 AACR. PMID:27150634

  20. IL-13 but not IL-4 signaling via IL-4Rα protects mice from papilloma formation during DMBA/TPA two-step skin carcinogenesis

    Interleukin 4 (IL-4) was shown to be tumor-promoting in full carcinogenesis studies using 3-methylcholanthrene (MCA). Because heretofore the role of IL-4 in DMBA/TPA (9,10-dimethyl-1,2-benz-anthracene/12-O-tetradecanoylphorbol-13-acetate) two-stage carcinogenesis was not studied, we performed such experiments using either IL-4−/− or IL-4Rα−/− mice. We found that IL-4Rα−/− but not IL-4−/− mice have enhanced papilloma formation, suggesting that IL-13 may be involved. Indeed, IL-13−/− mice developed more papillomas after exposure to DMBA/TPA than their heterozygous IL-13-competent littermate controls. However, when tested in a full carcinogenesis experiment, exposure of mice to 25 μg of MCA, both IL-13−/− and IL-13+/− mice led to the same incidence of tumors. While IL-4 enhances MCA carcinogenesis, it does not play a measurable role in our DMBA/TPA carcinogenesis experiments. Conversely, IL-13 does not affect MCA carcinogenesis but protects mice from DMBA/TPA carcinogenesis. One possible explanation is that IL-4 and IL-13, although they share a common IL-4Rα chain, regulate signaling in target cells differently by employing distinct JAK/STAT-mediated signaling pathways downstream of IL-13 or IL-4 receptor complexes, resulting in different inflammatory transcriptional programs. Taken together, our results indicate that the course of DMBA/TPA- and MCA-induced carcinogenesis is affected differently by IL-4 versus IL-13-mediated inflammatory cascades

  1. The change on the cell proliferation kinetics of the central and peripheral regions of DMBA induced hamster tongue cancer following irradiation

    A single Co-60 irradiation of 20 Gy was delivered to the tongue with carcinoma induced by 1%9, 10-dimethyl, 2-benzanthracene acetone solution in hamsters. One and 3 days after irradiation, cell kinetics of the central and peripheral regions was investigated by H-3 thymidine labelling method. Both initial labelling (L) and mitosis (M) indices were high in the central region and low in the peripheral region before irradiation. One and 3 days after irradiation, the L index was decreased by 43% in the central region; however, this was slight in the peripheral region. The M index after irradiation was decreased for the entire tumor--it was slightly decreased in the central region, and increased twofold in the peripheral region. Regarding cell cycle time (Tc), G-2 phase (TG-2), and mitosis phase (Tm), there was no difference between the central and peripheral regions before irradiation. In both the central and peripheral regions, Tc was delayed by 3 hours on Day one, but shortened by 6.5 hours on Day 3. The TG-2 in both regions were delayed by 2 hours on Day one and by 3 days on Day 3. The Tm increased 1.6-fold in the central region and 2.1-fold in the peripheral region on Day one. Similar tendency was seen on Day 3. DNA synthesis phase before and after irradiation did not differ in either the central or peripheral region. Similarly, no difference in G-1 phase (TG-1) in either region was observed before and one day after irradiation. However, the TG-1 in both regions was decreased by as much as 90% on Day 3. (N.K.)

  2. Study on combined effects of radiation and bleomycin on carcinoma of tongue iduced by DMBA in hamster

    Carcinoma of the tongue (Mostly squamous cell carcinoma) was induced in hamsters by 9,10-dimethyl-1, 2-benzanthracene (DMBA). The amount of various kinds of free radicals, which increased due to radioactive radiation and administration of bleomycin (BLM) in tongue and liver tissues, was determined by an electron spin resonance method. The hamsters were separated into seven groups: BLM administration only (group A1), 60Co-γ-ray irradiation only (A2), 60Co-γ-ray irradiation 30 min after BLM administration (A3), BLM administration 30 min after 60Co-γ-ray irradiation (A4), 60Co-γ-ray irradiation 24 h after BLM administration (A5), BLM administration 24 h after 60Co-γ-ray irradiation (A6), and the control (A7). Mean free radicals in the groups were compared, using samples fixed 5 min after treatment. The ratio of mean free radicals of carcinoma of the tongue were 2.6, 2.9, 3.7, 3.9, 3.0, 3.2, and 1 in A1, A2, A3, A4, A5, A6, and A7. The ratio of mean free radicals of the liver under the same condition were 1.5, 1.6, 3.3, 3.8, 2.2, 2.6, and 1. A combination of BLM and radioactive radiation increased the amount of free radicals in carcinoma of the tongue and in the liver. Especially BLM administration 30 min after 60Co-γ-ray irradiation showed a synergistic effect. Judging from the amount of free radicals determined, the effect of radioactive irradiation increased when combined with BLM administration. BLM was most effective when it was administered 5 min after radioactive irradiation. (Tsunoda, M.)

  3. Nuclear magnetic resonance spectroscopy in pancreatic disorders

    Ofer Kaplan


    Full Text Available Nuclear magnetic resonance spectroscopy (NMRS is a powerful technique that enables continuous monitoring of biochemical processes in tissues and organs in a non-invasive manner. A model of isolated perfused rat pancreas, suitable for NMRS studies, was developed. Acute pancreatitis was induced by injections of either 0.5 ml 5% sodium taurocholate (TC into the bile duets, or 1.0 ml 10% TC injections into the pancreatic parenchyma. Phosphorous (31P NMRS of experimental pancreatitis were characterized by a transient signal at -0.18±0.04 ppm which was assigned as solubilized lecithin, and can be used as an indicator of the early phases of the discase. Depletion of the high energy phosphorous compounds, phosphocreatine and ATP, were also found during acute pancreatitis, and paralleled the extension of the pathological damage. The role of NMRS in pancreatic cancer diagnosis and its treatment were assessed in three models of pancreatic neoplasms. Perfused MIA PaCa-2 human pancreatic cancer cells, subcutancously implanted pancreatic tumors in hamsters, and pancreatic tumors induced in-situ in rats by direct appiication of the carcinogen 7,12-dimethyl benzanthracene, were studied by phosphorous (31P, sodium (23Na and proton (¹H NMRS. 31P spectra of pancreatic cancer were qualitatively similar to those of intact organs. However, 31P NMRS was found to be useful for monitoring the effects of treatment. Total (infra- and extracellular sodium concentrations, measured in the solid tumors, were similar in both the normal pancreas and the pancreatic tumors (39-40 mmol/g wet weight. Proton spectra of perchloric acid extracts revealed several differences between tumors and control pancreases. The principal findings were elevated levels of the amino acid taurine, from I.17±O.39 mmol/g wet weight in healthy pancreases, to 2.79±0.71 mmol/g wet weight in pancreatic carcinoma in rats, and lactate levels which increased from 0.92±0.2 to 6.19±1.93 mmol/g wet weight

  4. Activation of Akt1 accelerates carcinogen-induced tumorigenesis in mammary gland of virgin and post-lactating transgenic mice

    Data from in vivo and in vitro studies suggest that activation of Akt regulates cell survival signaling and plays a key role in tumorigenesis. Hence, transgenic mice were created to explore the oncogenic role of Akt1 in the development of mammary tumors. The transgenic mice were generated by expressing myristoylated-Akt1 (myr-Akt1) under the control of the MMTV-LTR promoter. The carcinogen 7, 12 dimethyl-1,2-benzanthracene (DMBA) was used to induce tumor formation. The MMTV driven myr-Akt1 transgene expression was detected primarily in the mammary glands, uterus, and ovaries. The expression level increased significantly in lactating mice, suggesting that the response was hormone dependent. The total Akt expression level in the mammary gland was also higher in the lactating mice. Interestingly, the expression of MMTVmyr-Akt1 in the ovaries of the transgenic mice caused significant increase in circulating estrogen levels, even at the post-lactation stage. Expression of myr-Akt1 in mammary glands alone did not increase the frequency of tumor formation. However, there was an increased susceptibility of forming mammary tumors induced by DMBA in the transgenic mice, especially in mice post-lactation. Within 34 weeks, DMBA induced mammary tumors in 42.9% of transgenic mice post-lactation, but not in wild-type mice post-lactation. The myr-Akt1 mammary tumors induced by DMBA had increased phosphorylated-Akt1 and showed strong expression of estrogen receptor (ERα) and epidermal growth factor receptor (EGFR). In addition, Cyclin D1 was more frequently up-regulated in mammary tumors from transgenic mice compared to tumors from wild-type mice. Overexpression of Cyclin D1, however, was not completely dependent on activated Akt1. Interestingly, mammary tumors that had metastasized to secondary sites had increased expression of Twist and Slug, but low expression of Cyclin D1. In summary, the MMTVmyr-Akt1 transgenic mouse model could be useful to study mechanisms of ER

  5. 北京地区表层土壤中多环芳烃的分布特征及污染源分析%Distribution and sources of polycyclic aromatic hydrocarbon compounds in topsoil of Beijing, China

    张枝焕; 卢另; 贺光秀; 彭旭阳; 朱雷; 王新伟; 焦煦


    根据北京地区不同环境功能区62个样品的分析结果,讨论了研究区表层土壤中多环芳烃的分布特征及污染源类型.结果表明:(1)研究区表层土壤中检测到的多环芳烃主要包括萘、苊、菲、惹烯、三芴、荧蒽、芘、(屈)、苯并蒽、苯并[b]荧蒽、苯并[K]荧蒽、苯并[e]芘、苯并[a]芘、苝、二苯并[a,h]蒽、茚并[1,2,3-cd]芘、苯并[g,h,i]苝及其同系物;(2)不同环境功能区表层土壤中多环芳烃的组成及质量分数均存在一定的差别,16种优先控制的多环芳烃质量分数为175.1~10 344ng·g-1,其中城市中心区表层土壤中多环芳烃的质量分数最高,交通干线附近、工矿企业附近表层土壤中PAHs的质量分数较高,林地、果园和农田表层土壤中PAHs的质量分数较低;(3)表层土壤中PAHs既有来源于石油源,也有来源于化石燃料燃烧产物的,但不同功能区二者贡献存在差别,其中农业用地(林地、果园、农田)中PAHs主要来源于石油源(或部分来源于土壤母岩中的有机质),城区、交通干线附近及工矿企业附近表层土壤中PAHs污染源以化石燃料燃烧产物输入为主.%Sixty-two topsoil samples collected in Beijing were detected and analyzed.The distribution and contamination sources of Polyeyclic Aromatic Hydrocarbon Compounds (PAHs) were discussed.The results showed that (1) many kinds of PAHs in topsoil samples of Beijing were found, mainly including naphthalene, acenaphthene, phenanthrene, retene, fluorene, dibenzofuran,dibenzothiophene, fluoranthene, pyrene, chrysene, benzanthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[e]pyrene,benzo[a]pyrene, perylene, dibenzo[a,h]anthracene, indeno[1,2,3-cd]pyrene, benzo[g,h,i]perylene and their homologous compounds;(2) the composition and concentration of PAHs in topsoil samples from different environmental function areas were different.The concentration of sixteen prior pollutants PAHs was between 175