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Sample records for methotrexate-induced micronuclei production

  1. Curcumin and folic acid abrogated methotrexate induced vascular endothelial dysfunction.

    PubMed

    Sankrityayan, Himanshu; Majumdar, Anuradha S

    2016-01-01

    Methotrexate, an antifolate drug widely used in rheumatoid arthritis, psoriasis, and cancer, is known to cause vascular endothelial dysfunction by causing hyperhomocysteinemia, direct injury to endothelium or by increasing the oxidative stress (raising levels of 7,8-dihydrobiopterin). Curcumin is a naturally occurring polyphenol with strong antioxidant and anti-inflammatory action and therapeutic spectra similar to that of methotrexate. This study was performed to evaluate the effects of curcumin on methotrexate induced vascular endothelial dysfunction and also compare its effect with that produced by folic acid (0.072 μg·g(-1)·day(-1), p.o., 2 weeks) per se and in combination. Male Wistar rats were exposed to methotrexate (0.35 mg·kg(-1)·day(-1), i.p.) for 2 weeks to induce endothelial dysfunction. Methotrexate exposure led to shedding of endothelium, decreased vascular reactivity, increased oxidative stress, decreased serum nitrite levels, and increase in aortic collagen deposition. Curcumin (200 mg·kg(-1)·day(-1) and 400 mg·kg(-1)·day(-1), p.o.) for 4 weeks prevented the increase in oxidative stress, decrease in serum nitrite, aortic collagen deposition, and also vascular reactivity. The effects were comparable with those produced by folic acid therapy. The study shows that curcumin, when concomitantly administered with methotrexate, abrogated its vascular side effects by preventing an increase in oxidative stress and abating any reduction in physiological nitric oxide levels. PMID:26571019

  2. Induction of micronuclei by palmitic acid and its unique radiolytic product 2-dodecylcyclobutanone

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Palmitic acid (PA), one of the most abundant fatty acids in the human diet, can cause oxidative stress, DNA strand breakage, cellular necrosis and apoptosis in human and rodent cells in vitro. Radiolysis of PA leads to the formation of 2-dodecylcyclobutanone (2-DCB), a unique radiolytic product for...

  3. Protective Mechanisms of Thymoquinone on Methotrexate-induced Intestinal Toxicity in Rats

    PubMed Central

    El-Sheikh, Azza A.; Morsy, Mohamed A.; Hamouda, Azza H.

    2016-01-01

    Background: Intestinal toxicity is a serious side effect in methotrexate (MTX) chemotherapy. Objective: To investigate the mechanisms by which the anticancer drug MTX-induced intestinal damage could be prevented by thymoquinone (TQ), an active ingredient of Nigella sativa. Materials and Methods: TQ was given orally for 10 days, and MTX toxicity was induced at the end of day 3 of the experiment, with or without TQ pretreatment. Results: MTX caused intestinal damage, represented by distortion in normal intestinal histological structure, with significant oxidative stress, exhibited as decrease in reduced glutathione concentration and catalase activity, along with significant increase in malondialdehyde level compared to control group. MTX also caused nitrosative stress evident by increased intestinal nitric oxide (NO) level, with up-regulation of inducible NO synthase expression shown in immunohistochemical staining. Furthermore, MTX caused inflammatory effects as evident by up-regulation of intestinal necrosis factor-kappa beta and cyclooxygenase-2 expressions, which were confirmed by increased intestinal tumor necrosis factor-alpha level via enzyme-linked immunosorbent assay. Moreover, MTX caused apoptotic effect, as it up-regulated intestinal caspase 3 expression. Concomitant TQ significantly reversed the MTX-induced intestinal toxic effects by reversing intestinal microscopic damage, as well as significantly improving oxidative/nitrosative stress, inflammatory and apoptotic markers tested compared to MTX alone. Conclusion: TQ may possess beneficial intestinal protective effects as an adjuvant co-drug against MTX intestinal toxicity during cancer chemotherapy. TQ protection is conferred via antioxidant, anti-nitrosative, anti-inflammatory, and anti-apoptotic mechanisms. SUMMARY Methotrexate induces oxidative and nitrosative stress in intestinal tissuesMethotrexate also initiates inflammatory and apoptotic intestinal injuryThymoquinone co-administration ameliorates

  4. Screening of cytoprotectors against methotrexate-induced cytogenotoxicity from bioactive phytochemicals.

    PubMed

    Gu, Shaobin; Wu, Ying; Yang, Jianbo

    2016-01-01

    As a well known anti-neoplastic drug, the cytogenotoxicity of methotrexate (MTX) has received more attention in recent years. To develop a new cytoprotector to reduce the risk of second cancers caused by methotrexate, an umu test combined with a micronucleus assay was employed to estimate the cytoprotective effects of ten kinds of bioactive phytochemicals and their combinations. The results showed that allicin, proanthocyanidins, polyphenols, eleutherosides and isoflavones had higher antimutagenic activities than other phytochemicals. At the highest dose tested, the MTX genetoxicity was suppressed by 34.03%∼67.12%. Of all the bioactive phytochemical combinations, the combination of grape seed proanthocyanidins and eleutherosides from Siberian ginseng as well as green tea polyphenols and eleutherosides exhibited stronger antimutagenic effects; the inhibition rate of methotrexate-induced genotoxicity separately reached 74.7 ± 6.5% and 71.8 ± 4.7%. Pretreatment of Kunming mice with phytochemical combinations revealed an obvious reduction in micronucleus and sperm abnormality rates following exposure to MTX (p < 0.01). Moreover, significant increases in thymus and spleen indices were observed in cytoprotector candidates in treated groups. The results indicated that bioactive phytochemicals combinations had the potential to be used as new cytoprotectors. PMID:27190706

  5. Protective effects of propolis on methotrexate-induced testis injury in rat.

    PubMed

    Sönmez, Mehmet Fatih; Çilenk, Kübra Tuğçe; Karabulut, Derya; Ünalmış, Sunay; Deligönül, Erkan; Öztürk, İsmet; Kaymak, Emin

    2016-04-01

    Propolis is an adhesive substance which is collected and used by honeybees. Propolis is a potent antioxidant and a free radical scavenger. This study was designed to determine whether propolis could protect against dysfunction and oxidative stress induced by methotrexate-induced injury in rat testis. A total of 40 male Wistar albino rats were divided into four groups: group 1 was the untreated control. On the eighth day of the experiment, groups 2 and 3 received single intraperitoneal injections of methotrexate (MTX) at 20mg/kg. Groups 3 and 4 received 100mg/kg/day propolis (by oral gavage) for 15 days by the first day of the experimental protocol. Then the rats were decapitated under anesthesia, and their testes were removed. The histopathological and biochemical analysis along with apoptosis assessment of testis tissues were compared. Immunohistochemical analysis of Heat shock protein-70 (HSP-70) and Proliferating Cell Nuclear Antigen (PCNA) were performed. The phenolic characterization of propolis was performed by Liquid chromatography-mass spectrometry (LC-MS/MS). Methotrexate caused tended to increase in malondialdehyde level and in the number of apoptotic cells; it also caused a decrease in MSTD and JTBS, PCNA and HSP-70 expression and xanthine oxidase levels in group 2. Propolis prevented the rise in malondialdehyde, xanthine oxidase levels and HSP-70 expression and improved testicular morphology and JTBS. It was found that, methorexate gives rise to serious damage in the testes and propolis is a potent antioxidant agent in preventing testicular injury. PMID:27044811

  6. Screening of cytoprotectors against methotrexate-induced cytogenotoxicity from bioactive phytochemicals

    PubMed Central

    Wu, Ying; Yang, Jianbo

    2016-01-01

    As a well known anti-neoplastic drug, the cytogenotoxicity of methotrexate (MTX) has received more attention in recent years. To develop a new cytoprotector to reduce the risk of second cancers caused by methotrexate, an umu test combined with a micronucleus assay was employed to estimate the cytoprotective effects of ten kinds of bioactive phytochemicals and their combinations. The results showed that allicin, proanthocyanidins, polyphenols, eleutherosides and isoflavones had higher antimutagenic activities than other phytochemicals. At the highest dose tested, the MTX genetoxicity was suppressed by 34.03%∼67.12%. Of all the bioactive phytochemical combinations, the combination of grape seed proanthocyanidins and eleutherosides from Siberian ginseng as well as green tea polyphenols and eleutherosides exhibited stronger antimutagenic effects; the inhibition rate of methotrexate-induced genotoxicity separately reached 74.7 ± 6.5% and 71.8 ± 4.7%. Pretreatment of Kunming mice with phytochemical combinations revealed an obvious reduction in micronucleus and sperm abnormality rates following exposure to MTX (p < 0.01). Moreover, significant increases in thymus and spleen indices were observed in cytoprotector candidates in treated groups. The results indicated that bioactive phytochemicals combinations had the potential to be used as new cytoprotectors. PMID:27190706

  7. Methotrexate-Induced Acute Leukemia: Report of Three Cases and Review of the Literature

    PubMed Central

    Al-Anazi, Khalid A.; Eltayeb, Khalid I.; Bakr, Mohammed; Al-Mohareb, Fahad I.

    2009-01-01

    For many years, methotrexate has been used in the treatment of certain chronic medical disorders e.g. rheumatoid arthritis and psoriasis as well as a number of malignant disorders e.g. acute lymphoblastic leukemia, certain types of lymphoma and breast carcinoma. Its use has been associated with various systemic toxicities and complications. The association between methotrexate therapy and the development of lymphoma and pseudolymphoma is well established. In patients treated with methotrexate, the development of leukemia has been attributed to either the primary disorder e.g. rheumatoid arthritis or to other drugs used concomitantly e.g. cyclophosphamide. Reported here are two patients with rheumatoid arthritis and one patient with psoriasis treated with low dose methotrexate for variable periods of time. Two of these patients developed acute myeloid leukemia on myelodysplastic syndrome background, while the third patient developed pre-B acute lymphoblastic leukemia that expressed few myeloid markers and had a positive philadelphia chromosome. To our knowledge, these are the first reported cases of methotrexate-induced acute leukemia. PMID:24179373

  8. Taurine protects against methotrexate-induced toxicity and inhibits leukocyte death

    SciTech Connect

    Cetiner, Mustafa; Sener, Goeksel; Sehirli, A. Ozer; Eksioglu-Demiralp, Emel; Ercan, Feriha; Sirvanci, Serap; Gedik, Nursal; Akpulat, Sertac; Tecimer, Tuelay; Yegen, Berrak C. . E-mail: byegen@marmara.edu.tr

    2005-11-15

    The efficacy of methotrexate (MTX), a widely used cytotoxic chemotherapeutic agent, is often limited by severe side effects and toxic sequelae. Regarding the mechanisms of these side effects, several hypotheses have been put forward, among which oxidative stress is noticeable. The present study was undertaken to determine whether taurine, a potent free radical scavenger, could ameliorate MTX-induced oxidative injury and modulate immune response. Following a single dose of methotrexate (20 mg/kg), either saline or taurine (50 mg/kg) was administered for 5 days. After decapitation of the rats, trunk blood was obtained and the ileum, liver, and kidney were removed to measure malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity, and collagen content, as well as histological examination. Our results showed that MTX administration increased the MDA, MPO activity, and collagen contents and decreased GSH levels in all tissues (P < 0.001), while these alterations were reversed in taurine-treated group (P < 0.05-0.01). Elevated (P < 0.001) TNF-{alpha} level observed following MTX treatment was depressed with taurine (P < 0.01). Oxidative burst of neutrophils stimulated by phorbol myristate acetate was reduced in saline-treated MTX group (P < 0.001), while taurine abolished this effect. Similarly, flow cytometric measurements revealed that leukocyte apoptosis and cell death were increased in MTX-treated animals, while taurine reversed these effects (P < 0.05). Reduced cellularity in bone marrow samples of MTX-treated group (P < 0.01) was reversed back to control levels in taurine-treated rats. Severe degeneration of the intestinal mucosa, liver parenchyma, glomerular, and tubular epithelium observed in saline-treated group was improved by taurine treatment. In conclusion, it appears that taurine protects against methotrexate-induced oxidant organ injury and inhibits leukocyte apoptosis and may be of therapeutic potential in alleviating the

  9. Micronuclei in human alveolar macrophages.

    PubMed

    D'Agostini, F; Bonatti, S; Oddera, S; De Flora, S

    1992-01-01

    Occurrence of micronuclei was monitored in pulmonary alveolar macrophages collected from 31 individuals undergoing diagnostic bronchoalveolar lavage. The overall frequency of micronucleated cells was 3.88 +/- 1.84/1000, without any significant difference attributable to sex, age, pathology, occupation, or smoking habits. The lack of influence of cigarette smoke on this clastogenicity index presumably reflects the very low rate of mitoses of macrophages in the alveolar lumen. PMID:1579732

  10. N-acetylcysteine renoprotection in methotrexate induced nephrotoxicity and its effects on B-cell lymphoma

    PubMed Central

    Singh, Ruchi; Shah, Rikin; Turner, Curtis; Regueira, Osvaldo; Vasylyeva, Tetyana L.

    2015-01-01

    Background: Nephrotoxicity is one of the known side effects of methotrexate (MTX) therapy despite the use of conventional protective measures. Our objectives were to evaluate the effects of N-acetylcysteine (NAC) on MTX-induced toxicity in renal tubular cells and to evaluate whether adjunctive use of NAC interferes with MTX antitumor activity in the B-cell lymphoma. Methods: Kidney Epithelial (Madin-Darby canine kidney [MDCK]) cells were exposed to MTX (10 μM or 100 μM) alone and with NAC (0.2 mM or 0.4 mM). Reactive oxygen species (ROS) generation at 1, 2, 4, and 24 h was measured by flow cytometer. Quantification of total glutathione (GSH) was performed by using GSH assay kit. To measure the impact of NAC on the antitumor activity of MTX, B lymphoma cells were exposed to MTX alone and with NAC. A percentage of apoptosis was measured using fluorescein isothiocyanate in both cell lines. Quantitative data was presented as a means ± standard deviation, and P values were analyzed using the Student's t-test. Results: Apoptosis in MDCK cells were observed after 24 h of incubation with both 10 μM and 100 μM MTX. Maximum ROS generation was observed at 4 h and corresponded to GSH production. Treatment with 0.2 and 0.4 mM of NAC led to decrease percentages of apoptotic MDCK cells. NAC did not change either proliferation or apoptosis of B-cell lymphoma. Conclusion: Using NAC for kidney protection may not interfere with the antitumor activity of MTX. Further in vivo studies are warranted to confirm noninterference between MTX and NAC and assess synergistic antitumor effects. PMID:26811594

  11. Methotrexate Induced Pancytopenia

    PubMed Central

    Eivaz-Mohammadi, Sahar; Surapaneni, Shiri; Alsaadi, Hazem; Syed, Amer K.; Elamir, Mazhar

    2014-01-01

    The well-reported methotrexate (MTX) toxicities are based on the duration and cumulative dosing of drug. The typical toxicities can be predicted by the timing of drug administration, where mucositis occurs as an earlier effect, while myelosuppression and the sequelae of pancytopenia occur later after MTX administration. Despite these well-known toxicities, low dose MTX therapy can become problematic, in particular with the elderly, who are at a greater risk for significant myelosuppression. We present a case of a 73-year-old female with pancytopenia causing severe neutropenia, mucocutaneous bleeding, and bruising and requiring intravenous antibiotic therapy and limited transfusion dependence as a result of low dose daily MTX for rheumatoid arthritis. PMID:25006519

  12. Methotrexate-induced cirrhosis requiring liver transplantation in three patients with psoriasis. A word of caution in light of the expanding use of this 'steroid-sparing' agent.

    PubMed

    Gilbert, S C; Klintmalm, G; Menter, A; Silverman, A

    1990-04-01

    Methotrexate has been used for many years to treat refractory psoriasis. Three cases of methotrexate-induced cirrhosis requiring orthotopic liver transplantation are presented to emphasize the importance of strict adherence to published criteria for patient selection, monitoring of cumulative drug dosages, and the performance of serial liver biopsies. Each patient had been treated with long-term methotrexate therapy (cumulative doses far in excess of 1.5 g) without undergoing serial liver biopsies, contrary to well-established treatment guidelines. Caution must be exercised in using methotrexate as a steroid-sparing agent in the treatment of inflammatory diseases because of its potential to cause severe hepatotoxic effects with long-term usage and cumulative doses above 1.5 g. Patients easily become psychologically dependent on the drug, and physicians need to guard against the false sense of security engendered by normal results on liver function studies. PMID:2327848

  13. CHROMOTHRIPSIS FROM DNA DAMAGE IN MICRONUCLEI

    PubMed Central

    Zhang, Cheng-Zhong; Spektor, Alexander; Cornils, Hauke; Francis, Joshua M.; Jackson, Emily K.; Liu, Shiwei; Meyerson, Matthew; Pellman, David

    2015-01-01

    Genome sequencing has uncovered a new mutational phenomenon in cancer and congenital disorders called chromothripsis. Chromothripsis is characterized by extensive genomic rearrangements and an oscillating pattern of DNA copy number levels, all curiously restricted to one or a few chromosomes. The mechanism for chromothripsis is unknown, but we previously proposed that it could occur through the physical isolation of chromosomes in aberrant nuclear structures called micronuclei. Here, using a combination of live-cell imaging and single-cell genome sequencing, we demonstrate that micronucleus formation can indeed generate a spectrum of genomic rearrangements, some of which recapitulate all known features of chromothripsis. These events are restricted to the missegregated chromosome and occur within one cell division. We demonstrate that the mechanism for chromothripsis can involve the fragmentation and subsequent reassembly of a single chromatid from a micronucleus. Collectively, these experiments establish a new mutational process of which chromothripsis is one extreme outcome. PMID:26017310

  14. Emergence of micronuclei as a genomic biomarker

    PubMed Central

    Sabharwal, Robin; Verma, Parul; Syed, Mohammed Asif; Sharma, Tamanna; Subudhi, Santosh Kumar; Mohanty, Saumyakanta; Gupta, Shivangi

    2015-01-01

    The presence of micronuclei (MN) in mammalian cells is related to several mutagenetic stresses. MN are formed as a result of chromosome damage and can be readily identified in exfoliated epithelial cells. MN is chromatin particles derived from acentric chromosomal fragments, which are not incorporated into the daughter nucleus after mitosis. It can be visualized by chromatin stains. A variety of factors influences the formation of MN in cells such as age, sex, genetic constitution, physical and chemical agents, adverse habits such as tobacco, areca nut chewing, smoking, and alcohol consumption. Micronucleation has important implications in the genomic plasticity of tumor cells. The present paper reviews the origin, fate and scoring criteria of MN that serves as a biomarker of exposure to genetic toxins, and for the risk of cancer. PMID:26811590

  15. Emergence of micronuclei as a genomic biomarker.

    PubMed

    Sabharwal, Robin; Verma, Parul; Syed, Mohammed Asif; Sharma, Tamanna; Subudhi, Santosh Kumar; Mohanty, Saumyakanta; Gupta, Shivangi

    2015-01-01

    The presence of micronuclei (MN) in mammalian cells is related to several mutagenetic stresses. MN are formed as a result of chromosome damage and can be readily identified in exfoliated epithelial cells. MN is chromatin particles derived from acentric chromosomal fragments, which are not incorporated into the daughter nucleus after mitosis. It can be visualized by chromatin stains. A variety of factors influences the formation of MN in cells such as age, sex, genetic constitution, physical and chemical agents, adverse habits such as tobacco, areca nut chewing, smoking, and alcohol consumption. Micronucleation has important implications in the genomic plasticity of tumor cells. The present paper reviews the origin, fate and scoring criteria of MN that serves as a biomarker of exposure to genetic toxins, and for the risk of cancer. PMID:26811590

  16. Induction of micronuclei and sister chromatid exchanges by polycyclic and N-heterocyclic aromatic hydrocarbons in cultured human lymphocytes

    SciTech Connect

    Warshawsky, D.; Livingston, G.K.; LaDow, K.

    1995-12-31

    Many natural environments are contaminated with carcinogenic polycyclic aromatic hydrocarbons (PAHs) and N-heterocyclic aromatic hydrocarbons (NHAs) as complex mixtures of coal tar, petroleum, and shale oil. These potentially hazardous substances are prevalent at many former tar production and coal gasification sites. Three polycyclic [benzo(a)pyrene (BaP), benz(a)anthracene (BAA), and 7, 12-dimethylbenz(a)anthracene (DMBA)] and two N-heterocyclic [7H-dibenzo(c,g)carbazole (DBC), and dibenz(a,j)acridine (DBA)] aromatic hydrocarbons were analyzed for cytotoxic and genotoxic effects on human lymphocytes. All of these polyaromatic compounds are normally present in the environment, except for DMBA. Lymphocytes from healthy donors were isolated from whole blood. The 5-ring polycyclic aromatic BaP consistently induced micronuclei in a linear dose-dependent manner with doses from 0.1-10.0 {mu}g/ml, whereas the 4-ring compounds (BAA and DMBA) had no effect on the induction of micronuclei above controls except at 5 and 10 {mu}g/ml. Of the two N-heterocyclic compounds DBC produced a significant increase in micronuclei in lymphocytes, but the dose response tended to plateau above 0.1 {mu}g/ml. DBA showed an effect on the frequency of micronuclei above controls only at high doses of 5 and 10 {mu}g/ml. The average background frequency of micronuclei for 7 lymphocyte donors averaged 3.1 per 1,000 stimulated cells, whereas the average frequency of micronuclei at 10 {mu}g/ml BaP was 36.8 per 1,000 stimulated cells. The lowest effective dose in 2 donors for BaP occurred at 0.1 {mu}g/ml. 61 refs., 2 figs., 6 tabs.

  17. Micronuclei in lymphocytes from currently active uranium miners.

    PubMed

    Zölzer, Friedo; Hon, Zdeněk; Skalická, Zuzana Freitinger; Havránková, Renata; Navrátil, Leoš; Rosina, Jozef; Škopek, Jiří

    2012-08-01

    Micronuclei can be used as markers of past radiation exposure, but only few studies have dealt with uranium miners. In this paper, we report on micronuclei in lymphocytes from individuals currently working at Rožná, Czech Republic, the last functioning uranium mine in the European Union. A modified micronucleus-centromere test was applied to assess the occurrence of micronuclei in stimulated lymphocytes, as well as their content in terms of whole chromosomes or fragments. Compared with unexposed individuals, the miners had higher frequencies of micronucleus-containing lymphocytes and higher percentages of micronuclei without centromeres, and the differences were significant for both parameters (0.74 ± 0.60 vs. 0.50 ± 0.42, p = 0.017 and 49 ± 44 vs. 12 ± 21, p = 0.0002; means ± standard deviations). There were also significant correlations between one or other of these parameters on the one hand and various dose values on the other, in particular with a 'retrievable' dose, that is, a dose whose effect should still be recognisable in lymphocytes assuming a half-life of 3 years. The 'retrievable' dose at which a doubling of the micronucleus frequency was observed was around 35 mSv, corresponding to a total dose of 90 mSv received while working in the mines. Altogether, our data show that the micronucleus-centromere test is a valuable tool for the assessment of past radiation exposure in uranium miners. The scatter in the data is of course far too great to allow individual dosimetry, but for groups of a few dozen exposed individuals, the method can be used to monitor doses clearly below 100 mSv. PMID:22622995

  18. Mercury-induced micronuclei in skin fibroblasts of beluga whales

    SciTech Connect

    Gauthier, J.M.; Dubeau, H.; Rassart, E.

    1998-12-01

    Beluga whales (Delphinapterus leucas) inhabiting the St. Lawrence estuary are highly contaminated with environmental pollutants and have a high incidence of cancer. Environmental contaminants may be partly responsible for the high incidence of cancer observed in this population. DNA damage plays an important role in the development of cancer. The micronuclei assay was used to test the genotoxic potential of mercury compounds in skin fibroblasts of an Arctic beluga whale. Both mercuric chloride (Hg) and methylmercury (MeHg) induced a highly significant dose-response increase of micronucleated cells. Statistically significant increases in micronucleated cells were observed for 0.5, 5, and 20 {micro}g/ml Hg and 0.05, 0.5, and 2 {micro}g/ml MeHg when compared to control cultures. Concentrations of 0.5, 5, and 20 {micro}g/ml Hg induced a two-, three- and fourfold increase of micronucleated cells, respectively. Treatment with MeHg was one order of magnitude more potent in inducing micronuclei and in inhibiting cell proliferation than Hg. Although results of this in vitro study do not imply that mercury compounds are involved in the etiology of cancer in St. Lawrence beluga whales, significant increases in micronuclei frequency were found at low concentrations of MeHg that are believed to be comparable to concentrations present in certain whales of this population.

  19. In vivo kinetics of micronuclei induction by bifunctional alkylating antineoplastics.

    PubMed

    Morales-Ramírez, Pedro; Vallarino-Kelly, Teresita; Cruz-Vallejo, Virginia L; López-Iturbe, Rosario; Alvaro-Delgadillo, Horacio

    2004-05-01

    The aim of the present study was to determine in vivo the kinetics of micronucleated polychromatic erythrocyte (MN-PCE) induction in mice, as an approach for studying the mechanism of micronuclei induction by mitomycin C, cis-diamine dichloroplatinum, busulfan and bis-chloroethylnitrosourea, bifuctional alkylating antineoplastic agents having different patterns of crosslink induction. The kinetics of MN-PCE induction was established by scoring the frequency of MN-PCE in 2000 PCE in peripheral blood, for periods of 8 or 10 h after acute treatment and up to 80 h, with different doses of the agent. The kinetics of MN-PCE induction and particularly the times of maximal induction by different bifunctional alkylating agents were compared with the kinetics previously obtained for ethylnitrosourea, methylnitrosourea and 6-mercaptopurine, agents that cause MN-PCE mainly in the first, second and third divisions after exposure, respectively. The results obtained in the present study allow us to conclude that: (i) bifunctional alkylating agents have very different efficiencies of genotoxic and cytotoxic action; (ii) all assayed bifunctional alkylating agents induced micronuclei during the first cell division, owing to the mistaken repair of primary lesions, e.g. excision; (iii) busulfan and bis-chloroethylnitrosourea showed an additional late mechanism of micronuclei induction, which is expressed at the third division and seems to be related to the mismatch repair process. PMID:15123786

  20. Induction of micronuclei in hemocytes of Mytilus edulis and statistical analysis

    SciTech Connect

    Wrisberg, M.N.; Bilbo, C.M.; Spliid, H. )

    1992-04-01

    A genotoxicity test focusing on micronucleus production in the blood cells (hemocytes) of blue mussel M. edulis has been developed as a possible indicator for marine pollution. A linear dose-response relationship was found when M. edulis was exposed to low concentrations (0, 12.5, and 25 mg/liter) of the alkylating agent ethyl methanesulfonate under laboratory conditions, while higher concentrations (50 and 100 mg/liter) resulted in cytotoxic effects. Furthermore the micronuclei (MN) frequencies in wild mussels from four different field locations have been determined. Mussels collected from two polluted sites showed an elevated MN frequency, indicating the presence of genotoxic pollution. A method to determine the micronuclei background level is suggested and the further implications for applying the method in biomonitoring investigations are discussed. The considered M. edulis exhibits a high biological variation, emphasizing the importance of application of a correct statistical method. A systematic approach to the statistical evaluation of the mussel MN test is outlined. The statistical model includes three different situations: (a) estimation of parameters of a single sample, (b) estimation and comparison of two samples, and (c) estimation of a dose-response relationship. Cases (a) and (b) are especially relevant in biomonitoring investigations while case (c) primarily concerns laboratory experiments.

  1. Possible use of porphycenes as a membrane marker for flow cytometric detection of micronuclei

    SciTech Connect

    Wessels, J.M.; Nuesse, M. )

    1993-01-01

    For flow cytometric analysis of micronuclei induced by ionizing radiation or chemicals, debris plays an important role for the unambiguous detection of micronuclei. Several flow cytometric parameters have been used for a discrimination of micronuclei and debris (Schreiber et al., Cytometry 13:90-102, 1992). The lipophilic character of porphycenes can be used to selectively stain cellular and nuclear membranes. This chemical property of porphycenes requires the use of liposomes as a carrier. Porphycenes show high extinction coefficients at 360 nm and high fluorescence quantum yields between 600 nm and 750 nm. Due to their excellent photophysical properties they can therefore be used as a fluoroscent dye in combination with DNA specific dyes. Porphycenes (i.e. hydroxyethyl-tris(methoxyethyl)porphycene, HEPn) were used to either stain selectively the debris produced by membrane particles or to stain the membranes of nuclei and micronuclei for a better discrimination of debris and micronuclei.

  2. Reduction in oral mucosa micronuclei frequency following alpha-tocopherol treatment of oral leukoplakia.

    PubMed

    Benner, S E; Wargovich, M J; Lippman, S M; Fisher, R; Velasco, M; Winn, R J; Hong, W K

    1994-01-01

    Micronuclei frequency, a marker of genotoxicity, was studied within a trial of alpha-tocopherol for chemoprevention of oral leukoplakia. Oral swabs were obtained from two sites, the leukoplakia lesion and normal-appearing mucosa, at baseline and following 24 weeks of therapy with 400 international units of alpha-tocopherol twice daily. These specimens were analyzed for micronuclei frequency. The major risk factors for oral carcinogenesis in the group studied were cigarette smoking and alcohol consumption. alpha-tocopherol therapy produced a significant reduction in micronuclei frequencies in specimens from both the visible lesions (P < 0.01) and the normal-appearing mucosa (P < 0.01). The micronuclei frequencies, both at baseline and following therapy, were greater in specimens taken from the lesion than in those from the normal-appearing mucosa. Although these results indicate that alpha-tocopherol has a beneficial effect in oral carcinogenesis, there was no significant clinical or histological response associated with the change in micronuclei frequency. Micronuclei frequency has not yet been validated as a biomarker for cancer incidence, and consequently, its utility as an intermediate end point for chemoprevention trials is not known. Determining clinical significance of micronuclei frequency patterns in oral carcinogenesis and chemoprevention will require further study. PMID:8118389

  3. Three-dimensional organization of micronuclei induced by colchicine in PtK sub 1 cells

    SciTech Connect

    Geraud, G.; Laquerriere, F.; Masson, C.; Arnoult, J.; Labidi, B.; Hernandez-Verdun, D. )

    1989-03-01

    In PtK{sub 1} cells micronucleated by colchicine, the authors previously demonstrated that some micronuclei contain a single chromosome. Here, they investigated interphase chromosome organization in micronucleated PtK{sub 1} cells using conventional electron microscopy and three-dimensional computer reconstruction. The distribution of micronuclei was not always polarized, but in some cells they formed a ring. When this occurred, centrioles and Golgi apparatus were located inside the ring. On freeze-fracture replicas, they observed that nuclear pore distinction among the micronuclei was heterogeneous, and on thin sections some micronuclei displayed an incomplete nuclear envelope, with gaps in the double membrane and areas without lamina or condensed chromatin. By autoradiography, they showed that the fibrillar dots were not sites of active transcription. They applied three dimensional reconstruction to one micronucleated cell containing 22 micronuclei whose size indicated that each micronucleus probably contained one chromosome. In this cell they demonstrated that only the smallest micronuclei had an incomplete nuclear envelope. The presence in micronuclei of either nucleoli or fibrillar dots was found to be mutually exclusive. Taken together, these findings indicate that in the diploid nuclei of PtK{sub 1} cells, the three-dimensional organization of the nucleolar domain seems to be directly controlled by the X-chromosome.

  4. Micronuclei in genotoxicity assessment: from genetics to epigenetics and beyond

    PubMed Central

    Luzhna, Lidiya; Kathiria, Palak; Kovalchuk, Olga

    2013-01-01

    Micronuclei (MN) are extra-nuclear bodies that contain damaged chromosome fragments and/or whole chromosomes that were not incorporated into the nucleus after cell division. MN can be induced by defects in the cell repair machinery and accumulation of DNA damages and chromosomal aberrations. A variety of genotoxic agents may induce MN formation leading to cell death, genomic instability, or cancer development. In this review, the genetic and epigenetic mechanisms of MN formation after various clastogenic and aneugenic effects on cell division and cell cycle are described. The knowledge accumulated in literature on cytotoxicity of various genotoxins is precisely reflected and individual sensitivity to MN formation due to single gene polymorphisms is discussed. The importance of rapid MN scoring with respect to the cytokinesis-block micronucleus assay is also evaluated. PMID:23874352

  5. Genetic and environmental influences on spontaneous micronuclei frequencies in children and adults: a twin study.

    PubMed

    Jones, Kimberly H; York, Timothy P; Juusola, Jane; Ferreira-Gonzalez, Andrea; Maes, Hermine H; Jackson-Cook, Colleen

    2011-11-01

    The primary aim of this study was to quantify genetic and environmental influences on the frequency of spontaneously occurring micronuclei in children and adults. To meet this aim, a total of 63 male and female twin pairs and 19 singletons (145 individuals) were evaluated, ranging in age from 7 to 85 years. Micronuclei frequencies significantly increased with age for both genders (r = 0.49, P < 0.001), with the lowest and highest rates being seen in the 7- to 9 (mean = 0.56%, SD = .28) and 60- to 69-year-olds (mean = 2.12%, SD = 1.0), respectively. This age effect was significantly more pronounced in females than males (P = 0.017). In addition to the main effect of age, the completion of puberty in either gender (P = 0.036) and menopause in females (P = 0.024) was associated with a significant increase in micronuclei frequencies. Genetic model fitting indicated that influences from both additive genetic (65.2% of variance) and unique environmental (34.8% of variance) sources best explained the observed micronuclei frequencies in monozygotic and dizygotic twin pairs. Self-reported health conditions associated with an increased frequency of micronuclei included a history of allergies (P < 0.007) and migraines (P = 0.026). Multivitamin use was also associated with increased micronuclei frequencies (P = 0.004). In contrast, significantly lower micronuclei frequencies were associated with arthritis (P = 0.002), as well as consuming fruit (P = 0.014), green, leafy vegetables (P < 0.001) and/or folate-enriched bread (P = 0.035). A sex-specific effect, resulting in a significantly increased frequency of micronuclei with tobacco usage, was observed for females (but not males). Gender differences also moderated the impact of vitamin D and calcium consumption. In conclusion, the frequency of spontaneously arising micronuclei in humans is a complex trait, being influenced by both heritable genetic and environmental components. Recognition of factors contributing to baseline

  6. RNA polymerase activity in PtK1 micronuclei containing individual chromosomes: an in vitro and in situ study

    SciTech Connect

    Labidi, B.; Gregoire, M.; Frackowiak, S.; Hernandez-Verdun, D.; Bouteille, M.

    1987-03-01

    Micronuclei have been induced by colchicine in rat kangaroo (Potorous tridactylis) PtK1 cells. The synthesis of RNA was investigated both in isolated micronuclei by quantifying RNA polymerase activities at different ionic strengths with or without inhibitors, and in micronucleated cells by radioautography after (/sup 3/H)uridine pulse labeling. In vitro transcription shows that isolated micronuclei are able to take up (/sup 3/H)UTP. The rate curves of incorporation are close to those of isolated diploid nuclei, though the level of incorporation was relatively lower (65-70%) than control nuclei. This indicates that micronuclei react to the ionic environment and to inhibitors in the same manner as described for many species of isolated diploid nuclei. The labelling distributions plotted from radioautographs show that micronuclei were able to efficiently incorporate the hot precursor. Furthermore, for short pulses there is no homogeneity in the labelling density among the different micronuclei and there is no correlation between the labelling intensity and the size of micronuclei. After 60-min pulse time, there is an enhanced uptake of (/sup 3/H)uridine and all the micronuclei exhibit considerable labelling, although less than control cells. Thus, the micronuclei exhibit some characteristic RNA transcriptional activity in situ as well as after isolation. This material should be a particular interesting model with which to study the physiological activity and the role of each individual interphasic chromosome.

  7. Age-associated micronuclei, kinetochores and sex chromosome loss in men

    SciTech Connect

    Nath, J.; Hando, J.; Tucker, J.D.

    1995-11-01

    Studies on aneuploidy have shown a significant increase in the loss of chromosomes in both males and females with age and also a significant increase in micronucleus formation in lymphocytes with age. This study attempted (1) to ascertain whether the age-associated increase in Y chromosome loss and micronucleus formation are related. (2) to determine whether there is a correlation between Y chromosome-negative metaphase cells and Y chromosome-positive micronuclei from the same donors, and (3) to determine the relationships among the kinetochore status of micronuclei, Y chromosome-positive micronuclei, and age. Blood samples were obtained from thirty-five healthy males ranging in age from 22 to 79 years, and from the umbilical cords of eighteen newborn males. Two thousand binucleated cells were scored per sample. The kinetochore status of each micronucleus was recorded. Slides were then hybridized with the Y chromosome specific probe pHY10, labeled with biotinylated dUTP, and visualized with fluorescein conjugated avidin. All micronucleated cells were relocated and scored as Y+ or Y- depending on their Y probe status. A total of 303 micronuclei were scored, of which 41 (13.5%) contained the Y chromosome. ANOVA shows a significant increase in the number of Y chromosome-positive micronuclei with age (p<0.001). Of the 41 Y+ micronuclei 36 (87.8%) were kinetochore negative, suggesting a relationship between the absence of kinetochore function and micronucleus formation. Also, 500 metaphase spreads per sample were scored for the Y chromosome, showing an increase in Y-cells with age (p<0.001). A correlation analysis between Y chromosome-positive micronuclei and Y chromosome-negative metaphase cells resulted in a correlation coefficient of 0.71 (p.005).

  8. Association of CHMP4B and Autophagy with Micronuclei: Implications for Cataract Formation

    PubMed Central

    Sagona, Antonia P.; Nezis, Ioannis P.; Stenmark, Harald

    2014-01-01

    Autophagy is a mechanism of cellular self-degradation that is very important for cellular homeostasis and differentiation. Components of the endosomal sorting complex required for transport (ESCRT) machinery are required for endosomal sorting and also for autophagy and the completion of cytokinesis. Here we show that the ESCRT-III subunit CHMP4B not only localizes to normal cytokinetic bridges but also to chromosome bridges and micronuclei, the latter surrounded by lysosomes and autophagosomes. Moreover, CHMP4B can be co-immunoprecipitated with chromatin. Interestingly, a CHMP4B mutation associated with autosomal dominant posterior polar cataract abolishes the ability of CHMP4B to localize to micronuclei. We propose that CHMP4B, through its association with chromatin, may participate in the autophagolysosomal degradation of micronuclei and other extranuclear chromatin. This may have implications for DNA degradation during lens cell differentiation, thus potentially protecting lens cells from cataract development. PMID:24741567

  9. Frequencies of micronuclei detected on Mytilus galloprovincialis by different staining techniques after treatment with zinc chloride.

    PubMed

    Majone, F; Beltrame, C; Brunetti, R

    1988-01-01

    The frequencies of micronuclei induced by ZnCl2 and detected on the gill tissue of the marine mussel Mytilus galloprovincialis with different staining techniques (acridine orange, gallocyanin chromallum, Feulgen, Giemsa) were compared. At least in the used system, the Feulgen and gallocyanin chromallum methods gave a frequency of micronuclei significantly lower than that obtained with the acridine orange and Giemsa techniques. No significant difference between the frequencies obtained with acridine orange and Giemsa was shown. So, though the acridine orange is surely the method which provides the more reliable data, in environmental screening works the Giemsa technique may be more suitable for its simplicity. PMID:2461512

  10. Supraadditive formation of micronuclei in preimplantation mouse embryos in vitro after combined treatment with X-rays and caffeine

    SciTech Connect

    Mueller, W.U.S.; Streffer, C.; Wurm, R.

    1985-01-01

    The influence of caffeine (0.1 or 2 mM), X-rays (0.24 Gy or 0.94 Gy, or of a combination of both on the formation of micronuclei in early stages of preimplantation mouse embryos in vitro was studied. X-rays as well as caffeine induced micronuclei. The dose-effect curve after irradiation was linear for the dose range measured. Caffeine did not induce micronuclei if the concentration was 1 mM or less; between 1 mM and 7 mM, however, there was a linear increase in the number of micronuclei. A considerable enhancement of the number of radiation-induced micronuclei was observed when irradiation of the embryos was followed by a treatment with caffeine. Not only was the sum of the single effects exceeded by the combination effects, but the combination results even lay in the range of supraadditivity of the envelope of additivity.

  11. [Variability and dynamics of micronuclei rate in participants of transatlantic march of the VIIth Ukranian Antarctic expedition].

    PubMed

    Afanas'eva, E S; Bezrukov, V F; Shepeta, Iu B; Moiseenko, E V

    2004-01-01

    The estimation of individual variability and group dynamics of micronuclei rate in buccal cells of participants of transatlantic march of the VIIth Ukrainian Antarctic expedition (Sevastopol--UAS "Akademik Vernadsky"--Sevastopol) was carried out. The general average rate of micronuclei was 2.20 per thousand. Individual values of micronuclei frequencies varied in wide limits. The maximum value of CV was 92.4% and the minimal one was 48.4%. Individual averages of micronuclei rates varied from 1.70 to 2.78 per thousand. Dependence of individual and group dynamics of micronuclei rates on environmental factors (temperature, atmospheric pressure and storm activity) was tested. No significant correlation of these parameters was found. PMID:15715163

  12. Methotrexate-Induced Nasal Septal Perforation.

    PubMed

    Kaminska, Edidiong Ntuen; Sansaricq, Freda; Petronic-Rosic, Vesna

    2016-01-01

    A 58-year-old woman with a 31-year history of Hailey-Hailey (HH) disease that was refractory to treatment with mycophenolate mofetil, cyclosporine, dapsone, sulfasalazine, topical/oral antibiotics, and topical/oral steroids presented for alternative treatment options. Active erythematous, malodorous, eroded, and crusted plaques were present in the axillae, inframammary region, groin, and back (Figure 1). The patient had an undulant course, with acute exacerbations and partial remissions. During a 3-year period, she was prescribed oral methotrexate at a dose of 10 mg to 15 mg per week with daily oral folic acid (1 mg) supplementation, except on the day she took methotrexate. Oral clarithromycin and prednisone were also used intermittently for antibacterial and anti-inflammatory effects. PMID:27319962

  13. INDUCTION OF MICRONUCLEI BY X-RADIATION IN HUMAN, MOUSE, AND RAT PERIPHERAL BLOOD LYMPHOCYTES

    EPA Science Inventory

    We compared the radiosensitivity of human, rat, and mouse peripheral blood lymphocytes (PBLs) by analyzing micronuclei (MN) in cytochalasin B-induced binucleated (BN) cells. or each species and dose, 4 ml aliquots of whole blood were X-irradiated to obtain doses of 38, 75, 150, o...

  14. Buccal Micronuclei Assay as a Tool For Biomonitoring DNA Damage in Oral Lichen Planus

    PubMed Central

    Vidyalakshmi, S.; Nirmal, R. Madhavan; Veeravarmal, V.; Santhadevy, A.; Sumathy

    2016-01-01

    Introduction The malignant transformation rate of Oral Lichen Planus (OLP) is between 0% and 5.8%. Oral lesions of lichen planus clinically presents itself multifocally, simulating the process of field cancerization in high risk malignancies. The Buccal MicroNucleus Cytome Assay (BMN Assay) provides a platform to identify the high risk individuals by evaluating the markers of nuclear damage at an earliest micro invasive phase. Aim To evaluate DNA damage in exfoliated buccal mucosal cells in individuals with oral lichen planus lesions and thereby to delineate the high risk group. Materials and Methods Buccal smears from 22 OLP and 10 control samples were stained in modified Feulgen-Rossenback reaction for micronuclei assay. Cytological evaluation of number of MicroNucleated cells (CMN), Total Number of Micronuclei (TMN) in micronucleated cells was done in both groups. Results Frequency of micronucleated cells (CMN) when compared among the study and control group, a mean value of 4.27 ± 1.80 and 0.90 ± 0.88 were obtained respectively. On comparing the total number of micronuclei in the micronucleated cells (TMN) between the study and control groups, a mean value of 5.38 ± 2.42 and 1.5 ± 0.88 were obtained respectively. Conclusion There was a significant increase in the frequency of micronuclei and the micronucleated cells in the oral lichen planus as compared to normal individuals.

  15. Induction of micronuclei in rat bone marrow after chronic exposure to lead acetate trihydrate.

    PubMed

    Alghazal, M A; Sutiaková, I; Kovalkovicová, N; Legáth, J; Falis, M; Pistl, J; Sabo, R; Benová, K; Sabová, L; Váczi, P

    2008-10-01

    Lead increasingly contributes to pollution of the environment and may play a role in the development of adverse effects in the human and animal body. Data concerning its mutagenic, clastogenic, and carcinogenic properties have been conflicting. In this study, we evaluated the frequency of micronuclei in bone marrow erythrocytes of rats treated with lead acetate trihydrate. Outbred Wistar rats were exposed to a daily dose of 100 mg/L drinking water for 125 days. The mean value of the total number of micronuclei observed in polychromatic erythrocytes of female rats was significantly higher than that found in the control group (13.375 +/- 2.722 against 9.625 +/- 3.204 micronuclei/1000 cells; P = 0.024 in ANOVA). In exposed female animals, no significant reduction of the ratio of polychromatic to normochromatic erythrocytes was observed (0.990 +/- 0.228 against 1.208 +/- 0.195; P = 0.060 in ANOVA). The effects of lead acetate trihydrate in male rats are both cytotoxic and genotoxic because of a decrease in ratio of polychromatic to normochromatic erythrocytes (0.715 +/- 0.431 against 1.343 +/- 0.306; P = 0.023, ANOVA followed by Tukey test) and an increase in frequency of micronucleated polychromatic erythrocytes (24.167 +/- 7.859 against 4.0 +/- 4.528 micronuclei/1000 cells; P < or = 0.001, ANOVA followed by Tukey test), respectively. PMID:19106125

  16. Induction of micronuclei in germinating onion seed root tip cells irradiated with high energy heavy ions.

    PubMed

    Takatsuji, Toshihiro; Takayanagi, Hiroki; Morishita, Kana; Nojima, Kumie; Furusawa, Yoshiya; Nakazawa, Yuka; Matsuse, Michiko; Akamatsu, Sakura; Hirano, Natsuko; Hirashima, Natsuko; Hotokezaka, Saori; Ijichi, Toyomi; Kakimoto, Chika; Kanemaru, Tomomi; Koshitake, Mayumi; Moriuchi, Akiko; Yamamoto, Kensuke; Yoshikawa, Isao

    2010-01-01

    Effects of high LET charged particles on a perfect in-vivo system are an essential theme for the study of the biological effects of radiation. Germinating onion seeds are independent complete organisms and the radiation induced micronuclei in the root chip cells can be examined quantitatively and theoretically. We irradiated with three types of high energy accelerated heavy ions germinating onion seeds using a synchrotron and observed micronuclei in the root tip cells. Micronuclei induction showed characteristic dose responses of an upward convex bell shape and a steep rise near zero doses for all types of the ions. The bell curve dose responses, however, could be explained by a simple mathematical model. A parameter in the model which indicates micronuclei induction frequency and another parameter which indicates induction frequency of lethal damages (or damages delaying cell divisions) per heavy ion track were both proportional to square of the LET. Because we suspected by-stander effect concerning the dose responses rising steeply near zero doses and tapering off for higher doses, we tested acute irradiation to remove time of information transmittance between cells using a single spill (about 0.3 s) of the synchrotron beam. No difference was detected between normal multiple spill irradiations and single spill. PMID:20505265

  17. MICRONUCLEI IN BINUCLEATED LYMPHOCYTES OF MICE FOLLOWING EXPOSURE TO GAMMA RADIATION

    EPA Science Inventory

    Experiments were designed to investigate the induction of micronuclei (MN) in mouse peripheral blood lymphocytes (PBLs) after in vitro or in vivo exposure to 60Co gamma radiation. or the in vitro experiments, 4 ml of blood from male C57BL/6J mice were either irradiated in 6 ml Fa...

  18. Evolution of bubbles from gas micronuclei formed on the luminal aspect of ovine large blood vessels.

    PubMed

    Arieli, R; Marmur, A

    2013-08-01

    It has been shown that tiny gas nanobubbles form spontaneously on a smooth hydrophobic surface submerged in water. These nanobubbles were shown to be the source of gas micronuclei from which bubbles evolved during decompression of silicon wafers. We suggest that the hydrophobic inner surface of blood vessels may be a site of nanobubble production. Sections from the right and left atria, pulmonary artery and vein, aorta, and superior vena cava of sheep (n=6) were gently stretched on microscope slides and exposed to 1013 kPa for 18 h. Hydrophobicity was checked in the six blood vessels by advancing contact angle with a drop of saline of 71±19°, with a maximum of about 110±7° (mean±SD). Tiny bubbles ~30 μm in diameter rose vertically from the blood vessels and grew on the surface of the saline, where they were photographed. All of the blood vessels produced bubbles over a period of 80 min. The number of bubbles produced from a square cm was: in the aorta, 20.5; left atrium, 27.3; pulmonary artery, 17.9; pulmonary vein, 24.3; right atrium, 29.5; superior vena cava, 36.4. More than half of the bubbles were present for less than 2 min, but some remained on the saline-air interface for as long as 18 min. Nucleation was evident in both the venous (superior vena cava, pulmonary artery, right atrium) and arterial (aorta, pulmonary vein, left atrium) blood vessels. This newly suggested mechanism of nucleation may be the main mechanism underlying bubble formation on decompression. PMID:23624230

  19. In vitro induction of micronuclei by monofunctional methanesulphonic acid esters: possible role of alkylation mechanisms.

    PubMed

    Eder, Erwin; Kütt, Wolfgang; Deininger, Christoph

    2006-12-01

    Six monofunctional alkylating methanesulphonates of widely varying structures were investigated in the in vitro micronucleus assay with Syrian hamster embryo fibroblast cells. The results were compared with the alkylating activities measured in the 4-(nitrobenzyl)pyridine test (NBP-test) and the N-methyl mercaptoimidazole (MMI-test) as measures for S(N)2 reactivity as well as in the triflouoroacetic acid (TFA) solvolysis and the hydrolysis reaction as measures for S(N)1 reactivity in order to provide insights into the role of alkylation mechanisms on induction of micronuclei. Moreover we compared the results of micronucleus assay with those of the Ames tests in strain TA 100 and TA1535 and with those of the SOS chromotest with the strains PQ37, PQ243, PM21 and GC 4798. The potency of methanesulphonates to induce micronuclei depended only to a certain degree, on the total alkylating activity (S(N)1 and S(N)2 reactivity). An inverse, significant correlation between the Ames test and the micronucleus assay was observed and an inverse correlation between the micronucleus assay and the SOS chromotest with the different strains. The results indicate that the primary mechanism leading to induction of micronuclei is not O-alkylation in DNA as it is the case in the Ames test with the hisG46 strains TA1535 and TA100 and not N-alkylation as with the SOS chromotest. There is evidence that protein alkylation, e.g. in the spindle apparatus in mitosis is decisive for induction of micronuclei by alkylating compounds. The structurally voluminous methanesulphonates 2-phenyl ethyl methanesulphonate and 1-phenyl-2-propyl methanesulphonate show a clear higher micronuclei inducing potency than the other tested though the bulky methanesulphonates possess a lower total alkylating activity than the others. This effect can be explained by a higher disturbance during mitosis after alkylation of the spindle apparatus with the structurally more bulky methanesulphonates. PMID:17011536

  20. Radiation-induced micronuclei in peripheral erythrocytes of Rana catesbeiana: an aquatic animal model for in vivo genotoxicity studies

    SciTech Connect

    Krauter, P.W.; Anderson, S.L.; Harrison, F.L.

    1987-01-01

    An in vivo micronucleus assay for peripheral erythrocytes of Rana catesbeiana tadpoles was developed and evaluated. The assay was used to determine the spontaneous frequency of micronuclei in circulating erythrocytes in tadpoles from two different populations, to define the time from administering the clastogen to the maximum micronucleus frequency in peripheral erythrocytes, and to determine the response to radiation. The spontaneous frequency of micronuclei in circulating erythrocytes of early-stage tadpoles was low (3.6 +/- 2.8 micronuclei per 1,000 erythrocytes, MN o/oo), but higher than that of late-stage tadpoles (1.7 +/- 0.7 MN o/oo). The time from the exposure of early-stage tadpoles to radiation (2.1 Gy) to the maximum micronucleus frequency was about 2 wk. The increase in frequency of micronuclei in peripheral erythrocytes of late-stage tadpoles receiving doses ranging from 0.5 to 3.0 Gy was linear with dose; a 3-fold increase was obtained with a dose of 3.0 Gy. The spontaneous frequency of micronuclei in erythrocytes and the increase in frequency induced by radiation appeared to differ in tadpoles from different populations. Quantification of micronuclei in the peripheral erythrocytes of R catesbeiana tadpoles provides a promising whole-animal system for studies of genotoxicity in aquatic environments.

  1. Induction of Micronuclei in Human Fibroblasts from the Los Alamos High Energy Neutron Beam

    NASA Technical Reports Server (NTRS)

    Cox, Bradley

    2009-01-01

    The space radiation field includes a broad spectrum of high energy neutrons. Interactions between these neutrons and a spacecraft, or other material, significantly contribute to the dose equivalent for astronauts. The 15 degree beam line in the Weapons Neutron Research beam at Los Alamos Nuclear Science Center generates a neutron spectrum relatively similar to that seen in space. Human foreskin fibroblast (AG1522) samples were irradiated behind 0 to 20 cm of water equivalent shielding. The cells were exposed to either a 0.05 or 0.2 Gy entrance dose. Following irradiation, micronuclei were counted to see how the water shield affects the beam and its damage to cell nuclei. Micronuclei induction was then compared with dose equivalent data provided from a tissue equivalent proportional counter.

  2. Replication stress in early S phase generates apparent micronuclei and chromosome rearrangement in fission yeast

    PubMed Central

    Sabatinos, Sarah A.; Ranatunga, Nimna S.; Yuan, Ji-Ping; Green, Marc D.; Forsburg, Susan L.

    2015-01-01

    DNA replication stress causes genome mutations, rearrangements, and chromosome missegregation, which are implicated in cancer. We analyze a fission yeast mutant that is unable to complete S phase due to a defective subunit of the MCM helicase. Despite underreplicated and damaged DNA, these cells evade the G2 damage checkpoint to form ultrafine bridges, fragmented centromeres, and uneven chromosome segregations that resembles micronuclei. These micronuclei retain DNA damage markers and frequently rejoin with the parent nucleus. Surviving cells show an increased rate of mutation and chromosome rearrangement. This first report of micronucleus-like segregation in a yeast replication mutant establishes underreplication as an important factor contributing to checkpoint escape, abnormal chromosome segregation, and chromosome instability. PMID:26246602

  3. Using carbon nanotubes to induce micronuclei and double strand breaks of the DNA in human cells

    NASA Astrophysics Data System (ADS)

    Cveticanin, Jelena; Joksic, Gordana; Leskovac, Andreja; Petrovic, Sandra; Valenta Sobot, Ana; Neskovic, Olivera

    2010-01-01

    Carbon nanotubes are unique one-dimensional macromolecules with promising applications in biology and medicine. Since their toxicity is still under debate, here we present a study investigating the genotoxic properties of purified single wall carbon nanotubes (SWCNTs), multiwall carbon nanotubes (MWCNTs), and amide functionalized purified SWCNTs on cultured human lymphocytes employing cytokinesis block micronucleus assay and enumeration of γH2AX foci as a measure of double strand breaks (DSBs) of the DNA in normal human fibroblasts. SWCNTs induce micronuclei (MN) formation in lymphocytes and decrease the proliferation potential (CBPI) of cells. In a fibroblast cell line the same dose of SWCNTs induces γH2AX foci 2.7-fold higher than in a control. Amide functionalized purified SWCNTs behave differently: they do not disturb the cell proliferation potential of harvested lymphocytes, but induce micronuclei to a higher extent than SWCNTs. When applied on fibroblasts, amide functionalized SWCNTs also induce γH2AX foci, 3.18-fold higher than the control. The cellular effects of MWCNTs display the broad spectrum of clastogenic properties seen as the highest incidence of induced lymphocyte micronuclei and anaphase bridges among nuclei in binucleated cells. Surprisingly, the incidence of induced γH2AX foci was not as high as was expected by the micronucleus test, which indicates that MWCNTs act as clastogen and aneugen agents simultaneously. Biological endpoints investigated in this study indicate a close relationship between the electrochemical properties of carbon nanotubes and observed genotoxicity.

  4. Using carbon nanotubes to induce micronuclei and double strand breaks of the DNA in human cells.

    PubMed

    Cveticanin, Jelena; Joksic, Gordana; Leskovac, Andreja; Petrovic, Sandra; Sobot, Ana Valenta; Neskovic, Olivera

    2010-01-01

    Carbon nanotubes are unique one-dimensional macromolecules with promising applications in biology and medicine. Since their toxicity is still under debate, here we present a study investigating the genotoxic properties of purified single wall carbon nanotubes (SWCNTs), multiwall carbon nanotubes (MWCNTs), and amide functionalized purified SWCNTs on cultured human lymphocytes employing cytokinesis block micronucleus assay and enumeration of gamma H2AX foci as a measure of double strand breaks (DSBs) of the DNA in normal human fibroblasts. SWCNTs induce micronuclei (MN) formation in lymphocytes and decrease the proliferation potential (CBPI) of cells. In a fibroblast cell line the same dose of SWCNTs induces gamma H2AX foci 2.7-fold higher than in a control. Amide functionalized purified SWCNTs behave differently: they do not disturb the cell proliferation potential of harvested lymphocytes, but induce micronuclei to a higher extent than SWCNTs. When applied on fibroblasts, amide functionalized SWCNTs also induce gamma H2AX foci, 3.18-fold higher than the control. The cellular effects of MWCNTs display the broad spectrum of clastogenic properties seen as the highest incidence of induced lymphocyte micronuclei and anaphase bridges among nuclei in binucleated cells. Surprisingly, the incidence of induced gamma H2AX foci was not as high as was expected by the micronucleus test, which indicates that MWCNTs act as clastogen and aneugen agents simultaneously. Biological endpoints investigated in this study indicate a close relationship between the electrochemical properties of carbon nanotubes and observed genotoxicity. PMID:19946169

  5. Decompression sickness bubbles: are gas micronuclei formed on a flat hydrophobic surface?

    PubMed

    Arieli, R; Marmur, A

    2011-06-30

    It is a long-standing hypothesis that the bubbles which evolve as a result of decompression have their origin in stable gas micronuclei lodged in hydrophobic crevices, micelles of surface-active molecules, or tribonucleation. Recent findings supported by atomic force microscopy have indicated that tiny, flat nanobubbles form spontaneously on smooth, hydrophobic surfaces submerged in water. We propose that these nanobubbles may be the gas micronuclei responsible for the bubbles that evolve to cause decompression sickness. To support our hypothesis, we used hydrophilic and monolayer-covered hydrophobic smooth silicon wafers. The experiment was conducted in three main stages. Double distilled water was degassed at the low pressure of 5.60 kPa; hydrophobic and hydrophilic silicon wafers were placed in a bowl of degassed water and left overnight at normobaric pressure. The bowl was then placed in the hyperbaric chamber for 15 h at a pressure of 1013 kPa (=90 m sea water). After decompression, bubbles were observed and photographed. The results showed that bubbles only evolved on the hydrophobic surfaces following decompression. There are numerous hydrophobic surfaces within the living body (e.g., in the large blood vessels), which may thus be the sites where nanobubbles that serve as gas micronuclei for bubble evolution following decompression are formed. PMID:21376842

  6. Induction of micronuclei in human fibroblasts across the Bragg curve of energetic heavy ions.

    PubMed

    Wu, H; Hada, M; Meador, J; Hu, X; Rusek, A; Cucinotta, F A

    2006-10-01

    The space environment consists of a varying field of radiation particles including high-energy ions, with spacecraft shielding material providing the major protection to astronauts from harmful exposure. Unlike low-LEpsilonTau gamma or X rays, the presence of shielding does not always reduce the radiation risks for energetic charged-particle exposure. The dose delivered by the charged particle increases sharply as the particle approaches the end of its range, a position known as the Bragg peak. However, the Bragg curve does not necessarily represent the biological damage along the particle path since biological effects are influenced by the track structures of both primary and secondary particles. Therefore, the "biological Bragg curve" is dependent on the energy and the type of the primary particle and may vary for different biological end points. Here we report measurements of the biological response across the Bragg curve in human fibroblasts exposed to energetic silicon and iron ions in vitro at two different energies, 300 MeV/nucleon and 1 GeV/nucleon. A quantitative biological response curve generated for micronuclei per binucleated cell across the Bragg curve did not reveal an increased yield of micronuclei at the location of the Bragg peak. However, the ratio of mono- to binucleated cells, which indicates inhibition of cell progression, increased at the Bragg peak location. These results confirm the hypothesis that severely damaged cells at the Bragg peak are more likely to go through reproductive death and not be evaluated for micronuclei. PMID:17007550

  7. Radiation-induced micronuclei in peripheral erythrocytes of Rana catesbeiana: an aquatic animal model for in vivo genotoxicity studies

    SciTech Connect

    Krauter, P.W.; Anderson, S.L.; Harrison, F.L.

    1987-01-01

    An in vivo micronucleus assay for peripheral erythrocytes of Rana catesbeiana tadpoles was developed and evaluated. The assay was used to determine the spontaneous frequency of micronuclei in circulating erythrocytes in tadpoles from two different populations, to define the time from administering the clastogen to the maximum micronucleus frequency in peripheral erythrocytes, and to determine the response to radiation. The spontaneous frequency of micronuclei in circulating erythrocytes of early-stage tadpoles was low, but higher than that of late-stage tadpoles. The time from the exposure of early-stage tadpoles to radiation (2.1 Gy) to the maximum micronucleus frequency was about 2 wk. The increase in frequency of micronuclei in peripheral erythrocytes of late-stage tadpoles receiving doses ranging from 0.5 to 3.0 Gy was linear with dose; a 3-fold increase was obtained with a dose of 3.0 Gy. The spontaneous frequency of micronuclei in erythrocytes and the increase in frequency induced by radiation appeared to differ in tadpoles from different populations. Quantification of micronuclei in the peripheral erythrocytes of R castesbeiana tadpoles provides a promising whole-animal system for studies of genotoxicity in aquatic environments.

  8. Retinoic Acid-Treated Pluripotent Stem Cells Undergoing Neurogenesis Present Increased Aneuploidy and Micronuclei Formation

    PubMed Central

    Sartore, Rafaela C.; Campos, Priscila B.; Trujillo, Cleber A.; Ramalho, Bia L.; Negraes, Priscilla D.; Paulsen, Bruna S.; Meletti, Tamara; Costa, Elaine S.; Chicaybam, Leonardo; Bonamino, Martin H.; Ulrich, Henning; Rehen, Stevens K.

    2011-01-01

    The existence of loss and gain of chromosomes, known as aneuploidy, has been previously described within the central nervous system. During development, at least one-third of neural progenitor cells (NPCs) are aneuploid. Notably, aneuploid NPCs may survive and functionally integrate into the mature neural circuitry. Given the unanswered significance of this phenomenon, we tested the hypothesis that neural differentiation induced by all-trans retinoic acid (RA) in pluripotent stem cells is accompanied by increased levels of aneuploidy, as previously described for cortical NPCs in vivo. In this work we used embryonal carcinoma (EC) cells, embryonic stem (ES) cells and induced pluripotent stem (iPS) cells undergoing differentiation into NPCs. Ploidy analysis revealed a 2-fold increase in the rate of aneuploidy, with the prevalence of chromosome loss in RA primed stem cells when compared to naïve cells. In an attempt to understand the basis of neurogenic aneuploidy, micronuclei formation and survivin expression was assessed in pluripotent stem cells exposed to RA. RA increased micronuclei occurrence by almost 2-fold while decreased survivin expression by 50%, indicating possible mechanisms by which stem cells lose their chromosomes during neural differentiation. DNA fragmentation analysis demonstrated no increase in apoptosis on embryoid bodies treated with RA, indicating that cell death is not the mandatory fate of aneuploid NPCs derived from pluripotent cells. In order to exclude that the increase in aneuploidy was a spurious consequence of RA treatment, not related to neurogenesis, mouse embryonic fibroblasts were treated with RA under the same conditions and no alterations in chromosome gain or loss were observed. These findings indicate a correlation amongst neural differentiation, aneuploidy, micronuclei formation and survivin downregulation in pluripotent stem cells exposed to RA, providing evidence that somatically generated chromosomal variation accompanies

  9. [Tripartite motif-containing protein 34 (TRIM34) colocalized with micronuclei chromosome and hampers its movement to equatorial plate during the metaphase stage of mitosis].

    PubMed

    Sun, Dakang; An, Xinye; Ji, Bing; Cheng, Yanli; Gao, Honglian; Tian, Mingming

    2016-06-01

    Objective To examine whether tripartite motif-containing protein 34 (TRIM34) is colocalized with micronuclei and investigate the influence on the movement of micronuclei chromosome in mitosis. Methods The eukaryotic expression vector TRIM34-pEGFP-N3 was constructed, identified and then transfected into HEK293T cells. With 4', 6-diamidino-2-phenylindole 2HCI (DAPI) staining, the colocalization between TRIM34 and micronuclei was observed under a fluorescence microscope. Moreover, MitoTracker(R)Deep Red was used to identify the colocalization between the complex of TRIM34-micronulei and mitochondria under a confocal microscope. Finally, the effect of TRIM34 on the movement of micronuclei chromosome in mitosis was examined. Results DNA sequencing confirmed that the vector TRIM34-pEGFP-N3 was constructed successfully. A fluorescence microscope revealed that TRIM34 could be colocalized with micronuclei in HEK293T cells transfected with TRIM34-pEGFP-N3. In the same manner, a confocal microscope distinctly showed that TRIM34 was colocalized with micronuclei similarly in appearance. However, there was no distinguished colocalization relationship between the complex of TRIM34-micronulei and mitochondria. Interestingly, the micronuclei chromosome conjugated with TRIM34 was hardly transferred to equatorial plate during the metaphase stage of mitosis. Conclusion TRIM34 is colocalized with micronuclei chromosome and hampers its movement to equatorial plate in mitosis. PMID:27371841

  10. Micronuclei Assessment of The Radioprotective Effects of Melatonin and Vitamin C in Human Lymphocytes

    PubMed Central

    Rostami, Aram; Moosavi, Seyed Akbar; Dianat Moghadam, Hassan; Bolookat, Eftekhar Rajab

    2016-01-01

    Objective Critical macromolecules such as DNA maybe damaged by free radicals that are generated from the interaction of ionizing radiation with biological systems. Melatonin and vitamin C have been shown to be direct free radical scavengers. The aim of this study was to investigate the in vivo/in vitro radioprotective effects of melatonin and vitamin C separately and combined against genotoxicity induced by 6 MV x-ray irradiation in human cultured blood lymphocytes. Materials and Methods In this experimental study, fifteen volunteers were divided into three groups of melatonin, vitamin C and melatonin plus vitamin C treatment. Peripheral blood samples were collected from each group before, and 1, 2 and 3 hours after melatonin and vitamin C administration (separately and combined). The blood samples were then irradiated with 200 cGy of 6 MV x-ray. In order to characterize chromosomal aberrations, the lymphocyte samples were cultured with mitogenic stimulus on cytokinesisblocked binucleated cells. Results The samples collected 1hour after melatonin and vitamin C (separately and combined) ingestion exhibited a significant decrease in the incidence of micronuclei compared with their control group (P<0.05). The maximum synergic protection and reduction in frequency of micronuclei (57%) was observed 1 hour after vitamin C and melatonin administration combined. Conclusion We conclude that simultaneous administration of melatonin and vitamin C as radioprotector substances before irradiation may reduce genotoxicity caused by x-ray irradiation. PMID:27054118

  11. Distribution of Micronuclei in Human Fibroblasts across the Bragg Curve of Light and Heavy Ions

    NASA Technical Reports Server (NTRS)

    Hada, M.; Lacy, S.; Gridley, D. S.; Rusek, A.; Cucinotta, F. A.; Wu, H.

    2007-01-01

    The space environment consists of energetic particles of varying mass and energy, and understanding the :biological Bragg curve" is essential in optimizing shielding effectiveness against space radiation induced biological impacts. The "biological Bragg curve" is dependent on the energy and the type of the primary particle, and may vary for different biological endpoints. Previously, we studied the induction of micronuclei (MN) across the Bragg curve of energetic Fe and Si ions, and observed no increased yield of MN at the location of the Bragg peak. However, the ratio of mono- to bi-nucleated cells, which indicates inhibition of cell progression, was found higher at the Bragg peak location in comparison to the plateau region of the Bragg curve. Here, we report the induction of MN in normal human fibroblast cells across the Bragg curve of incident protons generated at Loma Linda University. Similar to Si and Fe ions, the ratio of mono- to bi-nucleated cells showed a clear spike as the protons reached the Bragg peak. Unlike the two heavy ions, however, the MN yield also increased at the Bragg peak location. These results confirm the hypothesis that severely damaged cells at the Bragg peak of heavy, but not light ions are more likely to go through reproductive death and not be evaluated for micronuclei.

  12. DIBENZO[A,L]PYRENE INDUCTION OF ERYTHROCYTE MICRONUCLEI IN A/J AND P53-DEFICIENT MICE

    EPA Science Inventory

    DIBENZO[a,l]PYRENE INDUCTION OF ERYTHROCYTE MICRONUCLEI IN AlJ AND P53-DEFICIENT MICE

    Male A/J and C57Bl/6 background p53+/+, p53+/- and p53-/- mice were treated with dibenzo[a,l]pyrene (DB[a,l]P), and micronucleus (MN) frequencies were measured in erythrocytes from bone ...

  13. Anticlastogenic effect of Spirulina maxima extract on the micronuclei induced by maleic hydrazide in Tradescantia.

    PubMed

    Ruiz Flores, L Elvia; Madrigal-Bujaidar, Eduardo; Salazar, María; Chamorro, Germán

    2003-02-01

    The aim of this investigation was to determine if extracts of Spirulina maxima reduce the genotoxic damage induced by maleic hydrazide (MH) using the Tradescantia biosssay. Two types of extracts from the alga were prepared: an aqueous extract with two different concentrations, 100 and 500 mg/ml, and a second one, the extract of a 1% solution of dimethyl sulfoxide (DMSO) which corresponded to 100 mg/ml of the alga. The capacity of MH to induce micronuclei (MN) was initially established by administering 0.005, 0.01, and 0.015 mg/ml of the chemical to the Tradescantia inflorescences, and observing its effect after 24 h.The results of this experiment showed a significant MN increase with the two high concentrations tested, although no dose-response effect was observed. For the anticlastogenic assay, the extracts of Spirulina were applied to the inflorescences alone or immediately before the application of MH (0.01 mg/ml) and the induced MN were observed 24 h later. We found that none of the extracts increased the MN level with respect to the untreated plants; also, that MH more or less doubled the basal micronuclei frequency, and finally, that all tested extracts reduced the genotoxic damage caused by MH. The inhibitory indices obtained for the aqueous extracts (100 and 500 mg/ml) and for the DMSO extract were respectively 59, 85, and 56.3%. These data indicate that Spirulina is an anticlastogenic agent and suggest that it is advisable to extend studies on this matter using other biological models. PMID:12527032

  14. Plasma microRNA Expression and Micronuclei Frequency in Workers Exposed to Polycyclic Aromatic Hydrocarbons

    PubMed Central

    Deng, Qifei; Huang, Suli; Zhang, Xiao; Zhang, Wangzhen; Feng, Jing; Wang, Tian; Hu, Die; Guan, Lei; Li, Jun; Dai, Xiayun; Deng, Huaxin; Zhang, Xiaomin

    2014-01-01

    Background: Ubiquitous polycyclic aromatic hydrocarbons (PAHs) have been shown to alter gene expression patterns and elevate micronuclei (MN) frequency, but the underlying mechanisms are largely unknown. MicroRNAs (miRNAs) are key gene regulators that may be influenced by PAH exposures and mediate their effects on MN frequency. Objectives: We sought to identify PAH-associated miRNAs and evaluate their associations with MN frequency. Methods: We performed a two-stage study in healthy male coke oven workers to identify miRNAs associated with PAH exposures quantified using urinary monohydroxy-PAHs and plasma benzo[a]pyrene-r-7,t-8,c-10-tetrahydrotetrol-albumin (BPDE–Alb) adducts. In the discovery stage, we used Solexa sequencing to test differences in miRNA expression profiles between pooled plasma samples from 20 exposed workers and 20 controls. We then validated associations with eight selected miRNAs in 365 workers. We further evaluated associations between the PAH-associated miRNAs and MN frequency. Results: In the discovery stage, miRNA expression profiles differed between the exposed and control groups, with 68 miRNAs significantly down-regulated [fold change (FC) ≤ –5] and 3 miRNAs mildly up-regulated (+2 ≤ FC < +5) in the exposed group. In the validation analysis, urinary 4-hydroxyphenanthrene and/or plasma BPDE–Alb adducts were associated with lower miR-24-3p, miR-27a-3p, miR-142-5p, and miR-28-5p expression (p < 0.030). Urinary 1-hydroxynaphthalene, 2-hydroxynaphthalene, 2-hydroxyphenanthrene, and the sum of monohydroxy-PAHs were associated with higher miR-150-5p expression (p < 0.030). These miRNAs were associated with higher MN frequency (p < 0.005), with stronger associations in drinkers (pinteraction < 0.015). Conclusions: Associations of PAH exposures with miRNA expression, and of miRNA expression with MN frequency, suggest potential mechanisms of adverse effects of PAHs that are worthy of further investigation. Citation: Deng Q, Huang S

  15. Micronuclei in Bone Marrow and Liver in relation to Hepatic Metabolism and Antioxidant Response due to Coexposure to Chloroform, Dichloromethane, and Toluene in the Rat Model

    PubMed Central

    Belmont-Díaz, Javier; López-Gordillo, Ana Paulina; Molina Garduño, Eunice; Serrano-García, Luis; Coballase-Urrutia, Elvia; Cárdenas-Rodríguez, Noemí; Arellano-Aguilar, Omar; Montero-Montoya, Regina D.

    2014-01-01

    Genotoxicity in cells may occur in different ways, direct interaction, production of electrophilic metabolites, and secondary genotoxicity via oxidative stress. Chloroform, dichloromethane, and toluene are primarily metabolized in liver by CYP2E1, producing reactive electrophilic metabolites, and may also produce oxidative stress via the uncoupled CYP2E1 catalytic cycle. Additionally, GSTT1 also participates in dichloromethane activation. Despite the oxidative metabolism of these compounds and the production of oxidative adducts, their genotoxicity in the bone marrow micronucleus test is unclear. The objective of this work was to analyze whether the oxidative metabolism induced by the coexposure to these compounds would account for increased micronucleus frequency. We used an approach including the analysis of phase I, phase II, and antioxidant enzymes, oxidative stress biomarkers, and micronuclei in bone marrow (MNPCE) and hepatocytes (MNHEP). Rats were administered different doses of an artificial mixture of CLF/DCM/TOL, under two regimes. After one administration MNPCE frequency increased in correlation with induced GSTT1 activity and no oxidative stress occurred. Conversely, after three-day treatments oxidative stress was observed, without genotoxicity. The effects observed indicate that MNPCE by the coexposure to these VOCs could be increased via inducing the activity of metabolism enzymes. PMID:24949447

  16. Micronuclei Induction in Human Fibroblasts Exposed In Vitro to Los Alamos High-Energy Neutrons

    NASA Technical Reports Server (NTRS)

    Gersey, Brad; Sodolak, John; Hada, Megumi; Saganti, Prem; Wilkins, Richard; Cucinotta, Francis; Wu, Honglu

    2006-01-01

    High-energy secondary neutrons, produced by the interaction of galactic cosmic rays with the atmosphere, spacecraft structure and planetary surfaces, contribute to a significant fraction to the dose equivalent in crew members and passengers during commercial aviation travel, and astronauts in space missions. The Los Alamos Nuclear Science Center (LANSCE) neutron facility#s ICE House 30L beamline is known to generate neutrons that simulate the secondary neutron spectra of earth#s atmosphere. The neutron spectrum is also similar to that measured onboard spacecraft like the MIR and International Space Station (ISS). To evaluate the biological damage, we exposed human fibroblasts in vitro to the LANSCE neutron beams without degrader at an entrance dose rate of 25 mGy/hr and analyzed the micronuclei (MN) induction. The cells were also placed behind a 9.9 cm water column to study effect of shielding in the protection of neutron induced damages. It was found that the dose response in the MN frequency was linear for the samples with and without shielding and the slope of the MN yield behind the shielding was reduced by a factor of 3.5. Compared to the MN induction in human fibroblasts exposed to a gamma source at a low dose rate, the RBE was found to be 16.7 and 10.0 for the neutrons without and with 9.9 cm water shielding, respectively.

  17. Induction of Micronuclei in Human Fibroblasts across the Bragg Curve of Energetic Si and Fe Ions

    NASA Technical Reports Server (NTRS)

    Wu, H.; Rusek, A.; Hada, M.

    2006-01-01

    The space environment consists of a varying field of radiation particles including high-energy ions, with spacecraft shielding material providing the major protection to astronauts from harmful exposure. Unlike low-LET gamma or X-rays, the presence of shielding does not always reduce the radiation risks for energetic charged particle exposure. Since the dose delivered by the charged particle increases sharply as the particle approaches the end of its range, a position known as the Bragg peak, the Bragg curve does not necessarily represent the biological damage along the particle traversal since biological effects are influenced by the track structure of both primary and secondary particles. Therefore, the biological Bragg curve is dependent on the energy and the type of the primary particle, and may vary for different biological endpoints. We studied micronuclei (MN) induction across the Bragg curve of Si and Fe ions at incident energies of 300 MeV/nucleon and 1 GeV/nucleon. A quantitative biological response curve did not reveal an increased yield of MN at the location of the Bragg peak. However, the ratio of mono- to bi-nucleated cells, which indicates inhibition in cell progression, increased at the Bragg peak location. These results confirm the hypothesis that severely damaged cells at the Bragg peak are likely to go through reproduction death.

  18. Frequencies of micronuclei in bank voles from zones of high radiation at Chernobyl, Ukraine

    SciTech Connect

    Rodgers, B.E.; Baker, R.J.

    2000-06-01

    A population of Clethrionomys glareolus (bank vole) from a highly radioactive area within the Chernobyl, Ukraine exclusion zone was sampled in June 1997 and in June and October 1998. Internal radiation doses from radiocesium were estimated to be as high as 8 rads/d. Total dose, which takes into account the internal dose form radiostrontium and the surrounding environment, was estimated to be 15 to 20 rads/d. In contrast, individuals from a reference population lying outside of the exclusion zone registered negligible levels of contamination. The authors used the micronucleus test in a double-blind study to analyze blood samples from 58 individuals. They scored more than 600,000 polychromatic erythrocytes (PCEs) but could not reject the null hypothesis that the frequency of micronucleated PCEs in voles exposed to radiation was equal to the frequency in unexposed voles. Results of their study stand in sharp contrast to earlier reports of increased frequencies of micronuclei in rodents exposed to fallout of the Chernobyl accident, but with radiation doses that were orders of magnitude lower than those reported here. Radio resistance and experimental methods are possible explanations for these differences in the results.

  19. Micronuclei induction in human fibroblasts exposed in vitro to Los Alamos high-energy neutrons

    NASA Astrophysics Data System (ADS)

    Gersey, Brad; Sodolak, John; Hada, Megumi; Saganti, Prem; Wilkins, Richard; Cucinotta, Francis; Wu, Honglu

    High-energy secondary neutrons, produced by the interaction of galactic cosmic rays with the atmosphere, spacecraft structure and planetary surfaces, contribute to a significant fraction to the dose equivalent in crew members and passengers during commercial aviation travel, and astronauts in space missions. The Los Alamos Nuclear Science Center (LANSCE) neutron facility's ICE House 30L beamline is known to generate neutrons that simulate the secondary neutron spectra of earth's atmosphere. The neutron spectrum is also similar to that measured onboard spacecraft like the MIR and International Space Station (ISS). To evaluate the biological damage, we exposed human fibroblasts in vitro to the LANSCE neutron beams without degrader at an entrance dose rate of 25 mGy/h and analyzed the micronuclei (MN) induction. The cells were also placed behind a 9.9 cm water column to study the effect of shielding in the protection of neutron induced damages. It was found that the dose response in the MN frequency was linear for the samples with and without shielding and the slope of the MN yield behind the shielding was reduced by a factor of 3.5. Compared to the MN induction in human fibroblasts exposed to a γ source at a similar low dose rate, the RBE was found to be 16.7 and 10.0 for the neutrons without and with the 9.9 cm water shielding, respectively.

  20. Potential Uses, Limitations, and Basic Procedures of Micronuclei and Nuclear Abnormalities in Buccal Cells

    PubMed Central

    Torres-Bugarín, Olivia; Zavala-Cerna, María Guadalupe; Nava, Arnulfo; Flores-García, Aurelio; Ramos-Ibarra, María Luisa

    2014-01-01

    The use of biomarkers as tools to evaluate genotoxicity is increasing recently. Methods that have been used previously to evaluate genomic instability are frequently expensive, complicated, and invasive. The micronuclei (MN) and nuclear abnormalities (NA) technique in buccal cells offers a great opportunity to evaluate in a clear and precise way the appearance of genetic damage whether it is present as a consequence of occupational or environmental risk. This technique is reliable, fast, relatively simple, cheap, and minimally invasive and causes no pain. So, it is well accepted by patients; it can also be used to assess the genotoxic effect derived from drug use or as a result of having a chronic disease. Furthermore the beneficial effects derived from changes in life style or taking additional supplements can also be evaluated. In the present paper, we aim to focus on the explanation of MN test and its usefulness as a biomarker; we further give details about procedures to perform and interpret the results of the test and review some factors that could have an influence on the results of the technique. PMID:24778463

  1. Induction of micronuclei in human fibroblasts across the Bragg curve of energetic heavy ions

    NASA Technical Reports Server (NTRS)

    Hada, Megumi; Rusek, Adam; Cucinotta, Francis A.; Wu, Honglu

    2006-01-01

    The space environment consists of a varying field of radiation particles including high energy ions, with spacecraft shielding material providing the major protection to astronauts from harmful exposure. Unlike low-L or X-rays, the presence of shielding does not always reduce the radiation risks for energetic charged particle exposure. Although the dose delivered by the charged particle increases sharply as the particle approaches the Bragg peak, the Bragg curve does not necessarily represent the biological damage along the particle traversal. The "biological Bragg curve" is dependent on the energy and the type of the primary particle, and may vary for different biological endpoints. To investigate "biological Bragg curves", we analyzed micronuclei (MN) induction along the particle traversal of Si and Fe ions at incident energies of 300 MeV/nucleon and 1 GeV/nucleon. A quantitative biological response curve did not reveal an increased yield of MN at the location of the Bragg peak. However, the ratio of mono-to bi-nucleated cells, which indicates inhibition in cell progression, increased at the Bragg peak location. These results confirm the hypothesis that "over kill" at the Bragg peak will affect the outcome of other biological endpoints.

  2. The Association of LINE-1 Hypomethylation with Age and Centromere Positive Micronuclei in Human Lymphocytes

    PubMed Central

    Cho, Yoon Hee; Woo, Hae Dong; Jang, Yoonhee; Porter, Virginia; Christensen, Sonja; Hamilton, Raymond F.; Chung, Hai Won

    2015-01-01

    Global hypomethylation in white blood cell (WBC) DNA has recently been proposed as a potential biomarker for determining cancer risk through genomic instability. However, the amplitude of the changes associated with age and the impacts of environmental factors on DNA methylation are unclear. In this study, we investigated the association of genomic hypomethylation with age, cigarette use, drinking status and the presence of centromere positive micronuclei (MNC+)—a biomarker for age-dependent genomic instability. Genomic hypomethylation of the repetitive element LINE-1 was measured in WBC DNA from 32 healthy male volunteers using the pyrosequencing assay. We also measured MNC+ with the micronucleus-centromere assay using a pan-centromeric probe. Possibly due to the small sample size and resulting low statistical power, smoking and drinking status had no significant effect on LINE-1 hypomethylation or the occurrence of MNC+. Consequently, we did not include them in further analyses. In contrast, LINE-1 hypomethylation and age significantly predicted MNC+; therefore, we examined whether LINE-1 hypomethylation plays a role in MNC+ formation by age, since genomic hypomethylation is associated with genomic instability. However, LINE-1 hypomethylation did not significantly mediate the effect of age on MNC+. Our data indicate that the repetitive element LINE-1 is demethylated with age and increasing MNC+ frequency, but additional studies are needed to fully understand the relation between genomic DNA hypomethylation, age and genomic instability. PMID:26196382

  3. Induction of micronuclei in mouse keratinocytes by polycyclic aromatic hydrocarbons and n-heterocyclic aromatics

    SciTech Connect

    Krishnan, S.P.; Warshawsky, D.

    1994-12-31

    This research is concerned with the ability of environmental carcinogens, benzo[a]pyrene (BaP), 7,12-dimethylbenz[a]anthracene (DMBA) and 7H-dibenzo(c,g)carbazole (DBC) to induce micronuclei (MN) in mouse keratinocytes. Mouse (HSD:ICR[Br]) keratinocytes (primary cultures) are grown on collagen coated microscope slides/dishes and dosed with the carcinogen (dissolved in 0.5% DMSO) for 12/24 hours. After carcinogen treatment, the medium is replaced with the medium containing cytochalasin-B and the cells are cultures for 72 hours. The binucleate fraction is used as a general indicator of cytotoxicity. MN are scored in 1000 acridine organs stained binucleated cells. Adriamycin, a direct acting compound, is used as a positive control. DBC induces a dose-dependent (0.01-1 {mu}g/ml) increase in MN (13-40.3 MN/1000 BN cells ) over controls (9.7{+-}1.8); N=3). In addition, 1 nmole/ml (256 ng/ml of DMBA induces twice the number of MN over controls (21.5{+-}1.1). In contrast, skin painting of higher non-cytotoxic doses of BaP (12 {mu}g/ml; 24 {mu}g/ml) showed BaP to be a weak inducer of MN over controls. Similar results were obtained in vitro. The lack of a significant response with BaP indicates that negative results in the mouse kerotinocyte MN assay should be interpreted with caution.

  4. Comparative study of frequency of micronuclei in normal, potentially malignant diseases and oral squamous cell carcinoma

    PubMed Central

    Sangle, Varsha Ajit; Bijjaragi, Shobha; Shah, Nishat; Kangane, Suresh; Ghule, Hrishikesh M.; Rani, SR Ashwini

    2016-01-01

    Context: The assessment of micronuclei (MN) in exfoliated oral epithelial cells is a promising tool for the study of epithelial carcinogens and can be used to detect chromosome breakage or mitotic interference, thought to be relevant to carcinogenesis. Aims: To detect MN in exfoliated oral mucosal cells in individuals using various tobacco forms and also to detect frequency of MN in premalignant lesions and conditions (potentially malignant diseases [PMD's]) and oral squamous cell carcinoma (OSCC). To correlate frequency of MN in oral exfoliated cells in clinically diagnosed cases of OSCC followed by a histopathological grading. Materials and Methods: A total of 90 subjects (30 smokeless tobacco users, 30 smokers and 30 nontobacco users) consisted of clinically diagnosed cases of PMD's and OSCC were selected for the study. Cytosmears from the groups were stained with rapid Papanicolaou stain. MN was identified according to the Tolbert et al. criteria. Results: MN cells were found to be significantly higher in smokeless tobacco users than in smokers. The frequency of MN was three to four times higher in patients with OSCC as compared to patients in PMD's (P < 0.0001). The frequency of MN correlated with the histopathological grade was statistically significant. Conclusion: MN index can be used as a biomarker/screening test among the high-risk groups particularly the smokeless tobacco users and PMD's. MN can be a candidate to serve as a biomarker for prediction of the grade of OSCC. PMID:27003966

  5. Micronuclei Frequencies and Nuclear Abnormalities in Oral Exfoliated Cells of Nuclear Power Plant Workers

    PubMed Central

    Babannavar, Roopa; Lohra, Abhishek; Kodgi, Ashwin; Bapure, Sunil; Rao, Yogesh; J., Arun; Malghan, Manjunath

    2014-01-01

    Aim: Biomonitoring provides a useful tool to estimate the genetic risk from exposure to genotoxic agents. The aim of this study was to evaluate the frequencies of Micronuclei (MN) and other Nuclear abnormalities (NA) from exfoliated oral mucosal cells in Nuclear Power Station (NPS) workers. Materials and Methods: Micronucleus frequencies in oral exfoliated cells were done from individuals not known to be exposed to either environmental or occupational carcinogens (Group I). Similarly samples were obtained from full-time Nuclear Power Station (NPS) workers with absence of Leukemia and any malignancy (Group II) and workers diagnosed as leukemic patients and undergoing treatment (Group III). Results: There was statistically significant difference between Group I, Group II & Group III. MN and NA frequencies in Leukemic Patients were significantly higher than those in exposed workers &control groups (p < 0.05). Conclusion: MN and other NA reflect genetic changes, events associated with malignancies. Therefore, there is a need to educate those who work in NPS about the potential hazard of occupational exposure and the importance of using protective measures. PMID:25654022

  6. Detection of micronuclei in peripheral erythrocytes of Cyprinus carpio exposed to metallic mercury.

    PubMed

    Nepomuceno, J C; Ferrari, I; Spanó, M A; Centeno, A J

    1997-01-01

    Cyprinus carpio fish (carp), exposed to elemental or metallic mercury (Hg0) at concentrations of 2.0, 20.0, and 200.0 mg per liter of water, were kept in concrete tanks for 159 days. Ten fish were used for each concentration level. Thirteen samples of peripheral blood were collected from each animal through gill puncture, 12 during the first 90 days of the experiment, and the last one at the end of the experiment. The micronucleus test (MNT) was designed to study dose and time yield effects of mercury after indirect exposure in vivo. The results indicated that for a concentration of 2.0 mg Hg0/l, there was no significant increase in frequency of micronuclei (MN), but at higher concentrations (20.0 and 200.0 mg Hg0/l) there was a significant increase in MN frequencies. This effect was higher after 31 days of exposure, followed by slight stabilization and gradual decrease. PMID:9366907

  7. Genotoxicity of nano/microparticles in in vitro micronuclei, in vivo comet and mutation assay systems

    PubMed Central

    Totsuka, Yukari; Higuchi, Takashi; Imai, Toshio; Nishikawa, Akiyoshi; Nohmi, Takehiko; Kato, Tatsuya; Masuda, Shuich; Kinae, Naohide; Hiyoshi, Kyoko; Ogo, Sayaka; Kawanishi, Masanobu; Yagi, Takashi; Ichinose, Takamichi; Fukumori, Nobutaka; Watanabe, Masatoshi; Sugimura, Takashi; Wakabayashi, Keiji

    2009-01-01

    Background Recently, manufactured nano/microparticles such as fullerenes (C60), carbon black (CB) and ceramic fiber are being widely used because of their desirable properties in industrial, medical and cosmetic fields. However, there are few data on these particles in mammalian mutagenesis and carcinogenesis. To examine genotoxic effects by C60, CB and kaolin, an in vitro micronuclei (MN) test was conducted with human lung cancer cell line, A549 cells. In addition, DNA damage and mutations were analyzed by in vivo assay systems using male C57BL/6J or gpt delta transgenic mice which were intratracheally instilled with single or multiple doses of 0.2 mg per animal of particles. Results In in vitro genotoxic analysis, increased MN frequencies were observed in A549 cells treated with C60, CB and kaolin in a dose-dependent manner. These three nano/microparticles also induced DNA damage in the lungs of C57BL/6J mice measured by comet assay. Moreover, single or multiple instillations of C60 and kaolin, increased either or both of gpt and Spi- mutant frequencies in the lungs of gpt delta transgenic mice. Mutation spectra analysis showed transversions were predominant, and more than 60% of the base substitutions occurred at G:C base pairs in the gpt genes. The G:C to C:G transversion was commonly increased by these particle instillations. Conclusion Manufactured nano/microparticles, CB, C60 and kaolin, were shown to be genotoxic in in vitro and in vivo assay systems. PMID:19725983

  8. Micronuclei in sputum from uranium workers: Epidemiologic application of an evolving cytogenetic technique

    SciTech Connect

    Loomis, D.P.

    1989-01-01

    The exfoliated-cell micronucleus assay is a relatively new cytogenetic technique which can provide a measure of the genetic effect of exposure to carcinogens and mutagens in target tissues where tumors arise among exposed populations. It is responsive to the effects of ionizing radiation and tobacco smoke in some in vivo human cell systems, but has not been extensively field tested as an indicator of lung cancer-related effects, despite the public health importance of exposure to occupational and environmental lung carcinogens. In this study the exfoliated-cell micronucleus assay was used to assess effects of exposure to radon progeny and cigarette smoke in a population of uranium industry workers (including employees in underground and open-pit mines, mills, laboratories, and administrative offices); underground uranium miners experience markedly elevated lung cancer risk because of exposure to ionizing radiation from radon progeny. Ninety-nine workers were selected at random from among workers in Colorado Plateau uranium-related facilities who participated in a workplace sputum cytology screening program from 1964-1988. The prevalence of cells with micronuclei was determined by a manual assay of one sputum specimen for each worker under a light microscope. Occupational and smoking data obtained by interview during screening were used to classify exposure and smoking status at the time the sputum specimen was taken and to obtain information on potential confounders and effect modifiers; underground miners were classified as exposed to radon progeny, and others were considered unexposed. Neither radon progeny exposure nor cigarette smoking had any appreciable effect on the prevalence of micronucleated cells. Crude prevalence ratios were 1.0 (95% CI 0.7-1.4) and 0.9 (95% CI 0.6-1.3), respectively, for radon exposure and smoking.

  9. Impact of p53 status on heavy-ion radiation-induced micronuclei in circulating erythrocytes

    NASA Technical Reports Server (NTRS)

    Chang, P. Y.; Torous, D.; Lutze-Mann, L.; Winegar, R.

    2000-01-01

    Transgenic mice that differed in their p53 genetic status were exposed to an acute dose of highly charged and energetic (HZE) iron particle radiation. Micronuclei (MN) in two distinct populations of circulating peripheral blood erythrocytes, the immature reticulocytes (RETs) and the mature normochromatic erythrocytes (NCEs), were measured using a simple and efficient flow cytometric procedure. Our results show significant elevation in the frequency of micronucleated RETs (%MN-RETs) at 2 and 3 days post-radiation. At 3 days post-irradiation, the magnitude of the radiation-induced MN-RET was 2.3-fold higher in the irradiated p53 wild-type animals compared to the unirradiated controls, 2.5-fold higher in the p53 hemizygotes and 4.3-fold higher in the p53 nullizygotes. The persistence of this radiation-induced elevation of MN-RETs is dependent on the p53 genetic background of the animal. In the p53 wild-type and p53 hemizygotes, %MN-RETs returned to control levels by 9 days post-radiation. However, elevated levels of %MN-RETs in p53 nullizygous mice persisted beyond 56 days post-radiation. We also observed elevated MN-NCEs in the peripheral circulation after radiation, but the changes in radiation-induced levels of MN-NCEs appear dampened compared to those of the MN-RETs for all three strains of animals. These results suggest that the lack of p53 gene function may play a role in the iron particle radiation-induced genomic instability in stem cell populations in the hematopoietic system.

  10. Flow cytometric analysis of micronuclei in rat peripheral blood: An interlaboratory reproducibility study.

    PubMed

    Kasamoto, Sawako; Mukai, Daisuke; Masumori, Shoji; Suzuki, Kenichiro; Tanaka, Ryota; Torous, Dorothea K; Yamate, Jyoji; Hayashi, Makoto

    2014-03-01

    In anticipation of proposed OECD guideline changes that may include increasing the number of reticulocytes scored for micronuclei, an inter-laboratory reproducibility study of the rat peripheral blood micronucleus assay was performed using flow cytometry. In this experiment, male Sprague-Dawley (SD) rats were treated with the model clastogen cyclophosphamide (CP: 5, 10 or 15mg/kg) by a single oral administration. As controls, rats were treated with physiological saline (solvent) in the same manner as for the model clastogen. Peripheral blood was collected from each rat 48h after the treatment. The blood samples were prepared at the Public Interest Incorporated Foundation, BioSafety Research Center (BSRC) in duplicate using the rat MicroFlow(PLUS) Kit. After fixation, one replicate set of samples was shipped to Litron Laboratories, and each sample was analyzed by flow cytometry at the two laboratories. In addition, the frequency of micronucleated reticulocytes (MNRETs) was determined at the BSRC by microscopic analysis using supravital acridine orange (AO) staining. The reproducibility of micronucleated reticulocyte frequencies analyzed by microscopy and flow cytometry showed good correlation (r(2)=0.84). The frequencies of micronucleated reticulocytes analyzed by flow cytometry at the two independent laboratories showed good concordance (r(2)=0.97). The data indicate that the flow cytometric micronucleus analysis method is a good alternative to manual microscopic analysis. Flow cytometry allows groups to readily score 5000 or even 20,000 RETs in a matter of minutes compared to manual analysis. This results in increased reliability of the assay by achieving better statistical power. PMID:24548793

  11. Baseline Micronuclei Frequency in Children: Estimates from Meta- and Pooled Analyses

    PubMed Central

    Neri, Monica; Ceppi, Marcello; Knudsen, Lisbeth E.; Merlo, Domenico Franco; Barale, Roberto; Puntoni, Riccardo; Bonassi, Stefano

    2005-01-01

    The number of studies evaluating the effect of environmental exposure to genotoxic agents in children has rapidly increased in the last few years. The frequency of micronuclei (MN) in peripheral blood lymphocytes determined with the cytokinesis block assay is among the most popular biomarkers used for this purpose, although large inter- and intralaboratory variability of this end point has been observed in population studies. The availability of reference measures is therefore necessary for laboratories to validate protocols and analytical procedures, and for molecular epidemiologists, as well, to estimate the statistical power of studies and to assess the quality of data. In this article, we provide estimates of the baseline frequency of MN in children, conducting a meta-analysis of MN frequency reported by field studies in children and a pooled analysis of individual data [available from published studies and from the Human Micronucleus International Collaborative Study (HUMN) database]. Thirteen articles were selected for meta-analysis, and individual data included in the pooled analysis were retrieved from the databases of 12 laboratories. Overall means of 4.48 [95% confidence interval (CI), 3.35–5.98] and 5.70 (95% CI, 4.29–7.56) MN per 1,000 binucleated cells were estimated by the meta- and pooled analysis, respectively. A clear effect of age was detected, even within the restricted range of pediatric age considered, with significantly lower frequency values in newborns. No influence of sex was found. The study showed the advantage of using data from large collaborative studies and suggested a synergistic use of meta- and pooled analysis. PMID:16140632

  12. Increased Susceptibility to Methotrexate-Induced Toxicity in Nonalcoholic Steatohepatitis

    PubMed Central

    Hardwick, Rhiannon N.; Clarke, John D.; Lake, April D.; Canet, Mark J.; Anumol, Tarun; Street, Stephanie M.; Merrell, Matthew D.; Goedken, Michael J.; Snyder, Shane A.; Cherrington, Nathan J.

    2014-01-01

    Hepatic drug metabolizing enzymes and transporters play a crucial role in determining the fate of drugs, and alterations in liver function can place individuals at greater risk for adverse drug reactions (ADRs). We have shown that nonalcoholic steatohepatitis (NASH) leads to changes in the expression and localization of enzymes and transporters responsible for the disposition of numerous drugs. The purpose of this study was to determine the effect of NASH on methotrexate (MTX) disposition and the resulting toxicity profile. Sprague Dawley rats were fed either a control or methionine-choline-deficient diet for 8 weeks to induce NASH, then administered a single ip vehicle, 10, 40, or 100 mg/kg MTX injection followed by blood, urine, and feces collection over 96 h with terminal tissue collection. At the onset of dosing, Abcc1–4, Abcb1, and Abcg2 were elevated in NASH livers, whereas Abcc2 and Abcb1 were not properly localized to the membrane, similar to that previously observed in human NASH. NASH rodents receiving 40–100 mg/kg MTX exhibited hepatocellular damage followed by initiation of repair, whereas damage was absent in controls. NASH rodents receiving 100 mg/kg MTX exhibited slightly greater renal toxicity, indicating multiple organ toxicity, despite the majority of the dose being excreted by 6 h. Intestinal toxicity in NASH however, was strikingly less severe than controls, and coincided with reduced fecal MTX excretion. Because MTX-induced gastrointestinal toxicity limits the dose escalation necessary for cancer remission, these data suggest a greater risk for life-threatening MTX-induced hepatic and renal toxicity in NASH in the absence of overt gastrointestinal toxicity. PMID:25080921

  13. Bombesin improves survival from methotrexate-induced enterocolitis.

    PubMed Central

    Chu, K U; Higashide, S; Evers, B M; Rajaraman, S; Ishizuka, J; Townsend, C M; Thompson, J C

    1994-01-01

    OBJECTIVE: The authors determined whether bombesin could improve survival from methotrexate (MTX)-induced enterocolitis. SUMMARY BACKGROUND DATA: Bombesin prevents gut mucosal atrophy, which is produced by feeding rats an elemental diet. Administration of MTX produces a lethal enterocolitis in rats fed an elemental diet. METHODS: On treatment day 0, 60 rats were divided randomly into three groups and fed an elemental diet (Vivonex TEN, Sandoz, Minneapolis, MN) as the only source of nutrition. Groups were subdivided further to receive either saline or bombesin (10 micrograms/kg, subcutaneously, three times a day) beginning either on day 0 or day 14. Methotrexate (20 mg/kg, intraperitoneally) was given to all rats 14 days after the start of an elemental diet. RESULTS: Bombesin prevented the mucosal atrophy in the ileum produced by the elemental diet and significantly decreased mortality in rats given MTX (whether given as a pretreatment or at the time of MTX administration). CONCLUSION: Bombesin significantly improved survival in a lethal model of MTX-induced enterocolitis, possibly by maintaining gut mucosal structure. Administration of bombesin to patients receiving chemotherapy may be clinically useful in preventing the severe enterocolitis induced by various chemotherapeutic agents. Images Figure 5. Figure 7. PMID:7944667

  14. In vitro RABiT measurement of dose rate effects on radiation induction of micronuclei in human peripheral blood lymphocytes

    PubMed Central

    Bertucci, Antonella; Smilenov, Lubomir B.; Turner, Helen C.; Amundson, Sally A.; Brenner, David J.

    2016-01-01

    Developing new methods for radiation biodosimetry has been identified as a high priority need in case of a radiological accident or nuclear terrorist attacks. A large-scale radiological incident would result in an immediate critical need to assess the radiation doses received by thousands of individuals. Casualties will be exposed to different doses and dose-rates due to their geographical position and sheltering conditions, and dose-rate is one of the principal factors that determine the biological consequences of a given absorbed dose. In these scenarios high-throughput platforms are required to identify the biological dose in a large number of exposed individuals for clinical monitoring and medical treatment. The RABiT (Rapid Automated Biodosimetry Tool) is designed to be completely automated from the input of blood sample into the machine to the output of a dose estimate. The primary goal of this paper was to quantify the dose-rate effects for RABiT-measured micronuclei in vitro in human lymphocytes. Blood samples from healthy volunteers were exposed in vitro to different doses of X-rays to acute and protracted doses over a period up to 24 hours. The acute dose (ADR) was delivered at ∼1.03Gy/min and the low dose rate (LDR) exposure at ∼0.31Gy/min. The results showed that the yield of micronuclei decreases with decreasing dose-rate starting at 2Gy, whereas response was indistinguishable from that of acute exposure in the low dose region, up to 0.5Gy. The results showed a linear-quadratic dose-response relationship for the occurrence of micronuclei for the acute exposure and a linear dose-response relationship for the low dose-rate exposure. PMID:26791381

  15. In vitro RABiT measurement of dose rate effects on radiation induction of micronuclei in human peripheral blood lymphocytes.

    PubMed

    Bertucci, Antonella; Smilenov, Lubomir B; Turner, Helen C; Amundson, Sally A; Brenner, David J

    2016-03-01

    Developing new methods for radiation biodosimetry has been identified as a high-priority need in case of a radiological accident or nuclear terrorist attacks. A large-scale radiological incident would result in an immediate critical need to assess the radiation doses received by thousands of individuals. Casualties will be exposed to different doses and dose rates due to their geographical position and sheltering conditions, and dose rate is one of the principal factors that determine the biological consequences of a given absorbed dose. In these scenarios, high-throughput platforms are required to identify the biological dose in a large number of exposed individuals for clinical monitoring and medical treatment. The Rapid Automated Biodosimetry Tool (RABiT) is designed to be completely automated from the input of blood sample into the machine to the output of a dose estimate. The primary goal of this paper was to quantify the dose rate effects for RABiT-measured micronuclei in vitro in human lymphocytes. Blood samples from healthy volunteers were exposed in vitro to different doses of X-rays to acute and protracted doses over a period up to 24 h. The acute dose was delivered at ~1.03 Gy/min and the low dose rate exposure at ~0.31 Gy/min. The results showed that the yield of micronuclei decreases with decreasing dose rate starting at 2 Gy, whereas response was indistinguishable from that of acute exposure in the low dose region, up to 0.5 Gy. The results showed a linear-quadratic dose-response relationship for the occurrence of micronuclei for the acute exposure and a linear dose-response relationship for the low dose rate exposure. PMID:26791381

  16. Smad7 foci are present in micronuclei induced by heavy particle radiation.

    PubMed

    Wang, Minli; Saha, Janapriya; Cucinotta, Francis A

    2013-08-30

    DNA damage and reactive oxygen species (ROS) generated by ionizing radiation (IR) activate DNA damage response (DDR) and cytokine signaling pathways, including double strand break (DSB) repair and TGFβ/Smad signaling pathway. Proteins assembled at IR-induced DSB sites can be visualized as foci, including γH2AX, 53BP1, ATM and ATF2. Unrepaired DSBs are thought to be one origin of micronuclei (MN), an indicator of genotoxic stress and chromosomal instability. Studies have detected γH2AX in IR-induced MN, indicating the presence of DSB in MN. Previously we reported that TGFβ downstream proteins Smad7 and phospho-Smad2 (pSmad2) co-localized with DDR proteins following radiation. Here we studied the status of Smad7 and pSmad2 in MN post high linear energy transfer (LET) radiation in human normal and cancerous cells. We observed γH2AX foci in IR-induced MN, whereas 53BP1 and ATF2 were absent. Interestingly, Smad7 foci, but not pSmad2, were detectable in both spontaneous and IR-induced MN. We compared the effect of particle track structures on the yield of MN using 5.6MeV/u boron (B) and 600MeV/u iron (Fe) particles with similar LET (200 and 180keV/μm, respectively) in human fibroblasts. The frequency of MN induced by B was lower than that by Fe particles, albeit the proportion of Smad7-positive to Smad7-negative MN remained constant. An increased frequency of spontaneous MN, with slightly higher ratio of Smad7 or γH2AX positive, was found in human prostate cancer cells (PC3) compared to normal cells. 24h after 1Gy of Fe particles exposure, the yield of MN increased, and the majority (∼70%) carried γH2AX and Smad7. Phospho-ATM (Ser1981) foci were found in both spontaneous and IR-induced MN in PC3 cells, displaying a much lower frequency compared to γH2AX and Smad7. Our data suggest a unique role of Smad7 in IR-induced MN formation, which may associate with DNA repair, apoptosis and genomic instability. PMID:23643526

  17. Induction and prevention of micronuclei and chromosomal aberrations in cultured human lymphocytes exposed to the light of halogen tungsten lamps.

    PubMed

    D'Agostini, F; Caimo, A; De Filippi, S; De Flora, S

    1999-07-01

    Previous studies have shown that the light emitted by halogen tungsten lamps contains UV radiation in the UV-A, UV-B and UV-C regions, induces mutations and irreparable DNA damage in bacteria, enhances the frequency of micronuclei in cultured human lymphocytes and is potently carcinogenic to the skin of hairless mice. The present study showed that the light emitted by an uncovered, traditional halogen lamp induces a significant, dose-related and time-related increase not only in micronuclei but also in chromosome-type aberrations, such as breaks, and even more in chromatid-type aberrations, such as isochromatid breaks, exchanges and isochromatid/chromatid interchanges, all including gaps or not, in cultured human lymphocytes. All these genotoxic effects were completely prevented by shielding the same lamp with a silica glass cover, blocking UV radiation. A new model of halogen lamp, having the quartz bulb treated in order to reduce the output of UV radiation, was considerably less genotoxic than the uncovered halogen lamp, yet induction of chromosomal alterations was observed at high illuminance levels. PMID:10390512

  18. Induction of micronuclei in cultured human lymphocytes with the mixture of highly toxic organochlorine compounds retained in human body.

    PubMed

    Nagayama, J; Nagayama, M; Iida, T; Hirakawa, H; Matsueda, T

    1997-05-01

    In this study, we investigated the effect of mixture of the organochlorine compounds, which very resembled their contamination profile of healthy Japanese people in its composition, on the induction of micronuclei in human whole-blood cultures in order to clarify their genotoxicity as a whole. The following results were obtained. Regardless of the presence or absence of 7, 8-benzoflavone (ANF) in the blood culture system, we observed a fairly good dose-response relationship between the concentration of the mixture and the induction of micronuclei. In particular, we found that 50% effective concentration of the mixture of the organochlorine chemicals was considered only about 7 times greater level over the average concentration in the healthy people, namely 70ppt as 2, 3, 7, 8-TCDD, in the absence of ANF and about 5 times more than that in the presence of ANF. Based on these results, the mixture was regarded as extremely genotoxic. Our human bodies, however, have already been contaminated with a variety of chemicals including PCDDs, PCDFs and Co-PCBs and accordingly one of the most important problems to be solved is a further comprehensive genotoxicity and health consequences due to these chemicals to the descendants. PMID:9194340

  19. Induction of micronuclei and alteration of gene expression by an organomodified clay in HepG2 cells.

    PubMed

    Maisanaba, Sara; Hercog, Klara; Ortuño, Natalia; Jos, Ángeles; Žegura, Bojana

    2016-07-01

    Clay2 is an organomodified montmorillonite developed by the Technological Institute of Packaging, Transport and Logistic (ITENE) in order to improve polymeric materials used in food packaging. There is not much known on Clay2 toxic potential, particularly at DNA level, therefore it is mandatory to assess its toxicity prior to its commercialization. In the present study the human hepatoma cell line (HepG2) was exposed to non-cytotoxic concentrations of Clay2 and the genomic stability was studied with the Cytokinesis block micronucleus cytome assay, by determining the formation of micronuclei (MN), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs). Moreover, the expression of various genes involved in the mechanisms of its action using the real-time quantitative PCR was studied. The results obtained provide the evidence that Clay2 is potentially genotoxic as it increased the frequency of micronuclei. In addition it deregulated genes involved in the metabolism, immediate-early response/signaling, DNA damage and oxidative stress showing new valuable information on the cellular response to Clay2. Nonetheless, further studies are highly needed to elucidate the molecular mechanisms of clays toxicity. PMID:27058916

  20. Water mutagenic potential assessment on a semiarid aquatic ecosystem under influence of heavy metals and natural radioactivity using micronuclei test.

    PubMed

    Chaves, Luiz Cláudio Cardozo; Navoni, Julio Alejandro; de Morais Ferreira, Douglisnilson; Batistuzzo de Medeiros, Silvia; Ferreira da Costa, Thomas; Petta, Reinaldo Antônio; Souza do Amaral, Viviane

    2016-04-01

    The contamination of water bodies by heavy metals and ionizing radiation is a critical environmental issue, which can affect water quality and, thus, human health. This study aimed to evaluate the water quality of the Boqueirão de Parelhas Dam in the Brazilian semiarid region. A 1-year study (2013-2014) was performed through the assessment of physicochemical parameters, heavy metal content, and radioactivity along with the mutagenicity potential of water using micronuclei test in Orechromis niloticus (in vivo) and the cytokinesis-block micronucleus (CBMN) assay in human lymphocytes (in vitro). A deterioration of water organoleptics characteristics by the presence of high levels of sulfate and total solids was observed. High concentrations of aluminum, nickel, silver, and lead along with the alpha particle content were higher than the limits suggested by the World Health Organization and Brazilian legislation for drinking water. An increase in the frequency of micronuclei and nuclear abnormalities was observed in both experimental models. The results obtained confirmed the mutagenic potential present in water samples. This study highlights that geogenic agents affect water quality becoming a human health concern to be taken into account due to the relevance that this water reservoir has in the region. PMID:26732704

  1. Elevated Frequencies of Micronuclei and other Nuclear Abnormalities of Chrome Plating Workers Occupationally Exposed to Hexavalent Chromium

    PubMed Central

    Sudha, S; Kripa, SK; Shibily, P; Shyn, J

    2011-01-01

    Background Biomonitoring provides a useful tool to estimate the genetic risk from exposure to genotoxic agents. The aim of this study was to assess the potential cytogenetic damage associated with occupational exposure to hexavalent chromium by using micronuclei (MN) as a biomarker. Methods This was a cross-sectional study and all participants were males. Both the exposed and control individuals were selected from Coimbatore, Southern India. Exfoliated buccal cells from 44 chrome plating workers and 40 age and sex matched control subjects were examined for MN frequency and nuclear abnormalities (NA) other than micronuclei, such as binucleates, broken eggs, karyorrhexis, karyolysis and pyknosis. Results Results showed statistically significant difference between chrome plating workers and control groups. MN and NA frequencies in chrome plating workers were significantly higher than those in control groups (p < 0.05) and also significantly related to smoking habit (P < 0.05). A significant difference in NA was observed in workers exposed to chromium for longer duration. In addition to this, a higher degree of NA was observed among smokers. Conclusion MN and other NA reflect genetic changes, events associated with carcinogenesis. Therefore the results of this study indicate that chrome plating workers are under risk of significant cytogenetic damage. Therefore, there is a need to educate those who work with heavy metals about the potential hazard of occupational exposure and the importance of using protective measures. PMID:26328050

  2. Hyperbaric oxygen pretreatment according to the gas micronuclei denucleation hypothesis reduces neurologic deficit in decompression sickness in rats.

    PubMed

    Katsenelson, K; Arieli, R; Arieli, Y; Abramovich, A; Feinsod, M; Tal, D

    2009-08-01

    During sudden or too rapid decompression, gas is released within supersaturated tissues in the form of bubbles, the cause of decompression sickness. It is widely accepted that these bubbles originate in the tissue from preexisting gas micronuclei. Pretreatment with hyperbaric oxygen (HBO) has been hypothesized to shrink the gas micronuclei, thus reducing the number of emerging bubbles. The effectiveness of a new HBO pretreatment protocol on neurologic outcome was studied in rats. This protocol was found to carry the least danger of oxygen toxicity. Somatosensory evoked potentials (SSEPs) were chosen to serve as a measure of neurologic damage. SSEPs in rats given HBO pretreatment before a dive were compared with SSEPs from rats not given HBO pretreatment and SSEPs from non-dived rats. The incidence of abnormal SSEPs in the animals subjected to decompression without pretreatment (1,013 kPa for 32 min followed by decompression) was 78%. In the pretreatment group (HBO at 304 kPa for 20 min followed by exposure to 1,013 kPa for 33 min and decompression) this was significantly reduced to 44%. These results call for further study of the pretreatment protocol in higher animals. PMID:19470698

  3. Relative biological effectiveness of fission neutrons for producing micronuclei in the root-tip cells of onion seedlings after irradiation as dry seeds.

    PubMed

    Zhang, Wenyi; Endo, Satoru; Ishikawa, Masayori; Ikeda, Hideo; Hoshi, Masaharu

    2002-12-01

    The relative biological effectiveness (RBE) of mixed neutron and gamma-ray radiation emitted at a 252Cf source at the Research Institute for Radiation Biology and Medicine, Hiroshima University, compared with 60Co gamma-ray radiation was determined. The tissue-absorbed dose contribution of the accompanying gamma radiation was about 35.7% to the total tissue-absorbed dose from the 252Cf mixed radiation. The 252Cf mixed radiation and 60Co gamma rays produced approximate linear changes in the frequency of micronuclei induced in root-tip cells of Allium cepa L. onion seedlings after irradiation as dry dormant seeds with varying absorbed doses in onion seeds. Therefore, the RBE for radiation-induced micronuclei was calculated as the ratio of the slopes for the 252Cf mixed radiation and the 60Co gamma rays. The deduced RBE value of 252Cf mixed radiation to 60Co gamma rays to induce micronuclei in dry dormant onion seed cells was about 90.5 +/- 3.6 (+/- 1sigma); the RBE of neutrons from the 252Cf mixed radiation was about 150 +/- 6 (+/- 1sigma). Furthermore, the sensitivity ratio of the induction rate of micronuclei in dry dormant seeds to that in seedlings by neutrons from 252Cf mixed radiation was significantly different from that by 60Co gamma rays. From these results, we concluded that the repair efficiency of DNA damage induced by neutrons may be different from that by gamma rays. PMID:12674204

  4. Failure of antimony trioxide to induce micronuclei or chromosomal aberrations in rat bone-marrow after sub-chronic oral dosing.

    PubMed

    Kirkland, David; Whitwell, James; Deyo, James; Serex, Tessa

    2007-03-01

    Antimony trioxide (Sb2O3, CAS 1309-64-4) is widely used as a flame retardant synergist in a number of household products, as a fining agent in glass manufacture, and as a catalyst in the manufacture of various types of polyester plastics. It does not induce point mutations in bacteria or mammalian cells, but is able to induce chromosomal aberrations (CA) in cultured cells in vitro. Although no CA or micronuclei (MN) have been induced after acute oral dosing of mice, repeated oral dosing for 14 or 21 days resulted in increased CA in one report, but did not result in increased MN in another. In order to further investigate its in vivo genotoxicity, Sb2O3 was dosed orally to groups of rats for 21 days at 250, 500 and 1000 mg/kg day. There were no clinical signs of toxicity in the Sb2O3-exposed animals except for some reductions in body-weight gain in the top dose group. Toxicokinetic measurements in a separate study confirmed bone-marrow exposure, and at higher levels than would have been achieved by single oral dosing. Large numbers of cells were scored for CA (600 metaphases/sex group) and MN (12,000 PCE/sex group) but frequencies of CA or MN in Sb2O3-treated rats were very similar to controls, and not biologically or statistically different, at all doses. These results provide further indication that Sb2O3 is not genotoxic to the bone marrow of rodents after 21 days of oral administration at high doses close to the maximum tolerated dose. PMID:17174592

  5. Induction of micronuclei in buccal mucosa on chewing a mixture of betel leaf, areca nut and tobacco.

    PubMed

    Sellappa, Sudha; Balakrishnan, Mythili; Raman, Sangeetha; Palanisamy, Subashini

    2009-06-01

    Betel quid containing areca nut and chewing tobacco is used in many parts of India. In this study we evaluated the micronuclei (MN) in buccal mucosa of healthy individuals from southern India, who were regularly chewing a mixture of betel leaf, areca nut and tobacco. A total of 44 subjects were examined. The study population included 15 chewers, 14 chewers with smoking habit and 15 controls with the mean age of 38.57 +/- 0.54, 34.50 +/- 0.95, and 33.28 +/- 0.89 years, respectively. The mean percentage of MN was 1.90 +/- 1.03 in chewers, 2.00 +/-1.12 in chewers with smoking habits and 0.81 +/- 0.66 in controls. There was no significant difference between the mean percentages of the two experimental groups. It can be concluded that a mixture of betel leaf, areca nut, and tobacco is unsafe for oral health. PMID:19550099

  6. Studies of micronuclei and other nuclear abnormalities in red blood cells of Colossoma macropomum exposed to methylmercury

    PubMed Central

    da Rocha, Carlos Alberto Machado; da Cunha, Lorena Araújo; da Silva Pinheiro, Raul Henrique; de Oliveira Bahia, Marcelo; Burbano, Rommel Mario Rodríguez

    2011-01-01

    The frequencies of micronuclei (MN) and morphological nuclear abnormalities (NA) in erythrocytes in the peripheral blood of tambaqui (Colossoma macropomum), treated with 2 mg.L−1 methylmercury (MeHg), were analyzed. Two groups (nine specimens in each) were exposed to MeHg for different periods (group A - 24 h; group B - 120 h). A third group served as negative control (group C, untreated; n = 9). Although, when compared to the control group there were no significant differences in MN frequency in the treated groups, for NA, the differences between the frequencies of group B (treated for 120 h) and the control group were extremely significant (p < 0.02), thus demonstrating the potentially adverse effects of MeHg on C. macropomum erythrocytes after prolonged exposure. PMID:22215976

  7. Mitotic slippage underlies the relationship between p53 dysfunction and the induction of large micronuclei by colcemid.

    PubMed

    Hashimoto, Kiyohiro; Todo, Takeshi

    2013-07-01

    Micronuclei induced by aneugens are larger than those induced by clastogens in both in vitro and in vivo micronucleus (MN) assays. p53 dysfunction increases the formation of large micronuclei following treatment with aneugens; this study sought to identify the mechanisms responsible for this. Treatment with colcemid, both a mitotic inhibitor and an aneugen, induced MN containing two or more chromosomes more frequently in NH32 cells, in which p53 function is compromised, than in TK6 cells, in which p53 is functional. This indicates that p53 dysfunction enhances aneugen-induced chromosome loss or perturbs apoptosis, resulting in the formation of large MN. To examine the former hypothesis, the incidence of chromosome malsegregation in colcemid-treated TK6 and NH32 cells was compared using the cytokinesis-block MN assay. The incidence of chromosome non-disjunction was higher in NH32 cells than in TK6 cells, whereas the incidence of MN containing two or more chromosomes was similar between the two cell lines. To address the involvement of apoptosis in cell cycle progression, examination of chromosome 8 distribution revealed that more mononuclear NH32 than TK6 cells were tetraploid after prolonged mitotic inhibition, which indicated that the more number of NH32 cells may have bypassed the spindle assembly checkpoint via mitotic slippage and progression into the next interphase. Cells that underwent mitotic slippage were likely to contain lagging chromosomes formed via chromosome malsegregation, resulting in MN separated from the main nucleus. The number of TK6 cells containing large MN following colcemid treatment was increased by treatment with a caspase inhibitor in a dose-dependent manner, indicating that TK6 cells with MN normally undergo apoptosis. In conclusion, these findings indicate that mitotic slippage and perturbed apoptosis contribute to the induction of large MN in p53-compromised cells following treatment with colcemid. PMID:23702691

  8. Simultaneous Analysis of SEPT9 Promoter Methylation Status, Micronuclei Frequency, and Folate-Related Gene Polymorphisms: The Potential for a Novel Blood-Based Colorectal Cancer Biomarker

    PubMed Central

    Ravegnini, Gloria; Zolezzi Moraga, Juan Manuel; Maffei, Francesca; Musti, Muriel; Zenesini, Corrado; Simeon, Vittorio; Sammarini, Giulia; Festi, Davide; Hrelia, Patrizia; Angelini, Sabrina

    2015-01-01

    One challenge in colorectal cancer (CRC) is identifying novel biomarkers to be introduced in screening programs. The present study investigated the promoter methylation status of the SEPT9 gene in peripheral blood samples of subjects’ positive fecal occult blood test (FOBT). In order to add new insights, we investigated the association between SEPT9 promoter methylation and micronuclei frequency, and polymorphisms in the folate-related pathway genes. SEPT9 promoter methylation, micronuclei frequency, and genotypes were evaluated on 74 individuals’ FOBT positive. Individuals were subjected to a colonoscopy that provided written informed consent for study participation. SEPT9 promoter methylation status was significantly lower in the CRC group than controls (p = 0.0006). In contrast, the CaCo2 cell-line, analyzed as a tissue specific model of colon adenocarcinoma, showed a significantly higher percentage of SEPT9 promoter methylation compared to the CRC group (p < 0.0001). Linear regression analysis showed an inverse correlation between micronuclei frequency and the decrease in the methylation levels of SEPT9 promoter region among CRC patients (β = −0.926, p = 0.0001). With regard to genotype analysis, we showed the involvement of the DHFR polymorphism (rs70991108) in SEPT9 promoter methylation level in CRC patients only. In particular, the presence of at least one 19 bp del allele significantly correlates with decreased SEPT9 promoter methylation, compared to the 19 bp ins/ins genotype (p = 0.007). While remaining aware of the strengths and limitations of the study, this represents the first evidence of a novel approach for the early detection of CRC, using SEPT9 promoter methylation, micronuclei frequency and genotypes, with the potential to improve CRC risk assessment. PMID:26633373

  9. Simultaneous Analysis of SEPT9 Promoter Methylation Status, Micronuclei Frequency, and Folate-Related Gene Polymorphisms: The Potential for a Novel Blood-Based Colorectal Cancer Biomarker.

    PubMed

    Ravegnini, Gloria; Zolezzi Moraga, Juan Manuel; Maffei, Francesca; Musti, Muriel; Zenesini, Corrado; Simeon, Vittorio; Sammarini, Giulia; Festi, Davide; Hrelia, Patrizia; Angelini, Sabrina

    2015-01-01

    One challenge in colorectal cancer (CRC) is identifying novel biomarkers to be introduced in screening programs. The present study investigated the promoter methylation status of the SEPT9 gene in peripheral blood samples of subjects' positive fecal occult blood test (FOBT). In order to add new insights, we investigated the association between SEPT9 promoter methylation and micronuclei frequency, and polymorphisms in the folate-related pathway genes. SEPT9 promoter methylation, micronuclei frequency, and genotypes were evaluated on 74 individuals' FOBT positive. Individuals were subjected to a colonoscopy that provided written informed consent for study participation. SEPT9 promoter methylation status was significantly lower in the CRC group than controls (p = 0.0006). In contrast, the CaCo2 cell-line, analyzed as a tissue specific model of colon adenocarcinoma, showed a significantly higher percentage of SEPT9 promoter methylation compared to the CRC group (p < 0.0001). Linear regression analysis showed an inverse correlation between micronuclei frequency and the decrease in the methylation levels of SEPT9 promoter region among CRC patients (β = -0.926, p = 0.0001). With regard to genotype analysis, we showed the involvement of the DHFR polymorphism (rs70991108) in SEPT9 promoter methylation level in CRC patients only. In particular, the presence of at least one 19 bp del allele significantly correlates with decreased SEPT9 promoter methylation, compared to the 19 bp ins/ins genotype (p = 0.007). While remaining aware of the strengths and limitations of the study, this represents the first evidence of a novel approach for the early detection of CRC, using SEPT9 promoter methylation, micronuclei frequency and genotypes, with the potential to improve CRC risk assessment. PMID:26633373

  10. Differences in the origins of kinetochore-positive and kinetochore-negative micronuclei: A live cell imaging study.

    PubMed

    Jiang, Erkang

    2016-05-01

    Micronuclei (MNi) are extensively used to evaluate genotoxicity and chromosomal instability. Classification of kinetochore-negative (K-MNi) and kinetochore-positive micronuclei (K+MNi) improves the specificity and sensitivity of the micronucleus (MN) test; however, the fundamental differences in the origins of K-MNi and K+MNi have not been addressed due to the limitations of traditional methods. In the current study, HeLa CENP B-GFP H2B-mCherry cells were constructed in which histone 2B (H2B) and centromere protein B (CENP B) were expressed as fusion proteins to monomeric Cherry (mCherry) and EGFP, respectively. MNi were identified using H2B-mCherry; K+MN contained CENP B-GFP, while K-MN did not. Long-term live cell imaging was conducted to examine MN formation in the dual-color fluorescent HeLa cells. The results suggested that K-MNi were derived from kinetochore-negative displaced chromosomes (K-DCs), kinetochore-negative lagging chromosomes (K-LCs) and fragments of broken chromosome bridges (CBs) during late mitotic stages. The results also indicated that K+MNi are derived from kinetochore-positive displaced chromosomes (K+DCs), kinetochore-positive lagging chromosomes (K+LCs), and fragments of broken CBs. Different aberrant chromosomes emerged during mitosis at different frequencies and developed into K-MNi and/or K+MNi in the daughter cells at different rates. K+LCs formed K+MNi at a higher frequency than K+DCs, and K-LCs formed K-MNi at a higher rate than K-DCs; however, broken CBs transformed into K-MNi and/or K+MNi. In summary, these results show that K-MNi and K+MNi have different origins in HeLa cells and that each mechanism of MN formation contributes differently to the overall number of K-MNi and K+MNi. PMID:26938028

  11. Studies on the alterations in haematological indices, micronuclei induction and pathological marker enzyme activities in Channa punctatus (spotted snakehead) perciformes, channidae exposed to thermal power plant effluent.

    PubMed

    Javed, Mehjbeen; Ahmad, Irshad; Ahmad, Ajaz; Usmani, Nazura; Ahmad, Masood

    2016-01-01

    The present study was conducted to assess the toxicity of thermal power plant effluent containing heavy metals (Fe > Cu > Zn > Mn > Ni > Co > Cr) on haematological indices, micronuclei, lobed nuclei and activity of pathological marker enzymes [alkaline phosphatase (ALP), aspartate transferase (AST), alanine transferase (ALT) and creatine kinase (CK)] in Channa punctatus. Total erythrocyte count (-54.52 %), hemoglobin (-36.98 %), packed cell volume (-36.25 %), mean corpuscular hemoglobin concentration (-1.41 %) and oxygen (O2) carrying capacity (-37.04 %) declined significantly over reference fish, however total leukocyte count (+25.43 %), mean corpuscular hemoglobin (+33.52 %) and mean corpuscular volume (+35.49 %) showed elevation. High frequency of micronuclei (1133.3 %) and lobed nuclei (150 %) were observed in exposed fish which may indicate mutagenesis. Activities of pathological marker enzymes ALP, AST, ALT and CK increased significantly in serum of exposed fish. The ratio of ALT: AST in exposed fish was beyond 1 which indicates manifestation of pathological processes. These biomarkers show that fish have macrocytic hypochromic anemia. Leukocytosis showed general defence response against heavy metal toxicity and marker enzymes showed tissue degeneration. In conclusion, thermal power plant effluent has strong potential to induce micronuclei, tissue pathology, making the fish anemic, weak, stressed and vulnerable to diseases. PMID:27386247

  12. Evaluation of the migration of mutagens/carcinogens from PET bottles into mineral water by Tradescantia/micronuclei test, Comet assay on leukocytes and GC/MS.

    PubMed

    Biscardi, D; Monarca, S; De Fusco, R; Senatore, F; Poli, P; Buschini, A; Rossi, C; Zani, C

    2003-01-20

    This study monitored the release of mutagenic/carcinogenic compounds into mineral water (natural and carbonated) from polyethylene terephthalate (PET) bottles, using a plant mutagenicity test which reveals micronuclei formation in Tradescantia pollen cells (Trad/MCN test), a DNA damage assay (Comet assay) on human leukocytes and gas chromatography/mass spectrometry (GC/MS) for the characterisation of migrants. The water samples were collected at a bottling plant and stored in PET bottles for a period ranging from 1 to 12 months. Every month some samples were randomly collected and lyophilised, the residual powders were extracted with organic solvents and then analysed by GC/MS and tested for DNA damage in human leukocytes, or reconstituted with distilled water to obtain concentrates for the exposure of Tradescantia inflorescences. Micronuclei increase in pollen was found only in natural mineral water stored for 2 months. DNA-damaging activity was found in many of the natural and carbonated water samples. Spring water was negative in the plant micronuclei test and the Comet assay, whereas distributed spring water showed DNA-damaging effects, suggesting a possible introduction of genotoxins through the distribution pipelines. GC/MS analysis showed the presence in mineral water of di(2-ethylhexyl)phthalate, a nongenotoxic hepatocarcinogenic plasticizer, after 9 months of storage in PET bottles. PMID:12526902

  13. Sister chromatid exchanges and micronuclei in lymphocytes of operating room personnel occupationally exposed to enfluorane and nitrous oxide.

    PubMed

    Pasquini, R; Scassellati-Sforzolini, G; Fatigoni, C; Marcarelli, M; Monarca, S; Donato, F; Cencetti, S; Cerami, F M

    2001-01-01

    The objective of this article is to assess whether occupational exposure to anesthetics increases genotoxic risk. We investigated two cytogenetic biomarkers, sister chromatid exchanges (SCE) and micronuclei (MN), in the peripheral blood lymphocytes of 46 anesthesiologists (24 men), working in operating rooms and mostly exposed to enfluorane and nitrous oxide, and 66 controls (35 men), not exposed to chemicals and living in the same area. Contrary to what was expected, a lower frequency of SCE was found in male anesthesiologists than in controls. Smoking status was found to be positively associated with SCE frequency in each group, while no relation to age was evident. On the contrary, MN frequency was significantly higher in female, but not male, anesthesiologists than in controls. Age and smoking status did not modify the association. No relationship between MN frequency and duration of employment was found in anesthesiologists. Smoking status and mean number of cigarettes smoked per day in smokers were not associated with MN frequency in either anesthesiologists or in controls. MN analysis seems to be a sensitive index of possible genotoxic effects of occupational exposure to anesthesiologists, and women appear to be more susceptible to these effects than men. PMID:11394710

  14. Environmentally Relevant Concentrations of Atrazine and Ametrine Induce Micronuclei Formation and Nuclear Abnormalities in Erythrocytes of Fish.

    PubMed

    Botelho, R G; Monteiro, S H; Christofoletti, C A; Moura-Andrade, G C R; Tornisielo, V L

    2015-11-01

    A rapid and sensitive method using liquid chromatography coupled with mass spectrometry triple quadrupole direct aqueous injection for analysis of atrazine and ametrine herbicides in surface waters was developed. According to the validation method, water samples from six different locations in the Piracicaba River were collected monthly from February 2011 to January 2012 and injected into a liquid chromatographer/dual mass spectrometer without the need for sample extraction. The method was validated and shown to be precise and accurate; limits of detection and quantification were 0.07 and 0.10 µg L(-1) for atrazine and 0.09 and 0.14 µg L(-1) for ametrine. During the sampling period, concentrations of atrazine ranged from 0.11 to 1.92 µg L(-1) and ametrine from 0.25 to 1.44 µg L(-1). After analysis of the herbicides, Danio rerio were exposed a range of concentrations found in the river water to check the induction of micronuclei and nuclear abnormalities (NAs) in erythrocytes. Concentrations of atrazine and ametrine >1.0 and 1.5 µg L(-1), respectively, induced MN formation in D. rerio. Ametrine was shown to be more genotoxic to D. rerio because a greater incidence of NAs was observed compared with atrazine. Therefore, environmentally relevant concentrations of atrazine and ametrine found in the Piracicaba River are dangerous to the aquatic biota. PMID:26081367

  15. Assessment of chromosomal aberrations and micronuclei in peripheral lymphocytes from tunisian hospital workers exposed to ionizing radiation.

    PubMed

    Sakly, Amina; Ayed, Yosra; Chaari, Neila; Akrout, Mohamed; Bacha, Hassen; Cheikh, Hassen Ben

    2013-09-01

    Epidemiological studies suggest that cytogenetic biomarkers, such as micronuclei (MN) in peripheral blood lymphocytes may predict cancer risk because they indicate genomic instability. The objective of the present study was to evaluate the frequencies of MN and chromosome aberrations (CA) in peripheral blood lymphocytes of hospital workers exposed to ionizing radiation and healthy subjects. The study was conducted using peripheral blood lymphocytes from 30 workers from the radiology department and 30 from the cardiology department. This study included 27 healthy age- and sex-matched individuals as the control group. The assessment of chromosomal damage was carried out by the use of CA and micronucleus assays in peripheral lymphocytes. Our results show that CA and micronucleus frequencies were significantly higher among the exposed groups when compared to controls. Our finding of significant increase of CA and MN frequencies in peripheral lymphocytes in exposed workers indicates a potential cytogenetic hazard due to this exposure. The enhanced chromosomal damage of subjects exposed to genotoxic agents emphasizes the need to develop safety programs. PMID:23216272

  16. Incidence of micronuclei in human peripheral blood lymphocytes exposed to modulated and unmodulated 2450 MHz radiofrequency fields.

    PubMed

    Vijayalaxmi; Reddy, Abhishek B; McKenzie, Raymond J; McIntosh, Robert L; Prihoda, Thomas J; Wood, Andrew W

    2013-10-01

    Peripheral blood samples from four healthy volunteers were collected and aliquots were exposed in vitro for 2 h to either (i) modulated (wideband code division multiple access, WCDMA) or unmodulated continuous wave (CW) 2450 MHz radiofrequency (RF) fields at an average specific absorption rate of 10.9 W/kg or (ii) sham-exposed. Aliquots of the same samples that were exposed in vitro to an acute dose of 1.5 Gy ionizing gamma-radiation (GR) were used as positive controls. Half of the aliquots were treated with melatonin (Mel) to investigate if such treatment offers protection to the cells from the genetic damage, if any, induced by RF and GR. The cells in all samples were cultured for 72 h and the lymphocytes were examined to determine the extent of genetic damage assessed from the incidence of micronuclei (MN). The results indicated the following: (i) the incidence of MN was similar in incubator controls, and those exposed to RF/sham and Mel alone; (ii) there were no significant differences between WCDMA and CW RF exposures; (iii) positive control cells exposed to GR alone exhibited significantly increased MN; and (iv) Mel treatment had no effect on cells exposed to RF and sham, while such treatment significantly reduced the frequency of MN in GR-exposed cells. PMID:23720062

  17. Effects of shielding on the induction of 53BP1 foci and micronuclei after Fe ion exposures

    PubMed Central

    Hu, Wentao; Pei, Hailong; Li, He; Ding, Nan; He, Jinpeng; Wang, Jufang; Furusawa, Yoshiya; Hirayama, Ryoichi; Matsumoto, Yoshitaka; Liu, Cuihua; Li, Yinghui; Kawata, Tetsuya; Zhou, Guangming

    2014-01-01

    High atomic number and high-energy (HZE) particles in deep space are of low abundance but substantially contribute to the biological effects of space radiation. Shielding is so far the most effective way to partially protect astronauts from these highly penetrating particles. However, simulated calculations and measurements have predicted that secondary particles resulting from the shielding of cosmic rays produce a significant fraction of the total dose and dose equivalent. In this study, we investigated the biological effects of secondary radiation with two cell types, and with cells exposed in different phases of the cell cycle, by comparing the biological effects of a 200 MeV/u iron beam with a shielded beam in which the energy of the iron ion beam was decreased from 500 MeV/u to 200 MeV/u with PMMA, polyethylene (PE), or aluminum. We found that beam shielding resulted in increased induction of 53BP1 foci and micronuclei in a cell-type-dependent manner compared with the unshielded 200 MeV/u Fe ion beam. These findings provide experimental proof that the biological effects of secondary particles resulting from the interaction between HZE particles and shielding materials should be considered in shielding design. PMID:23728321

  18. Micronuclei assessment in the urothelial cells of women using hair dyes and its modulation by genetic polymorphisms.

    PubMed

    Espinoza, Felicidad; Silverman, Debra; Kogevinas, Manolis; Creus, Amadeu; Fernández, Francisco; García-Closas, Montserrat; Tardon, Adonina; García-Closas, Reina; Serra, Consol; Carrato, Alfredo; Rothman, Nathaniel; Dosemeci, Mustafa; Malats, Nuria; Marcos, Ricard

    2008-05-18

    Increases in the frequency of micronuclei (MN) in exposed cells can be used as a measure of genotoxicity. Hair dyes contain chemicals that are eliminated by urine and could be genotoxic to urothelial cells. To address this question, we evaluated whether hair dye use is associated with an increase in the frequency of MN in urothelial cells, and whether this association is modified by NAT1 (N-acetyltransferase 1), NAT2 (N-acetyltransferase 2) and GSTM1 (glutathione-S-transferase M1) genotypes. We included 92 women participating as controls in a bladder cancer case-control study in Spain. Of those, 72 had adequate number of cells to be included in the MN analysis. There were no significant differences in the mean MN frequency in women using hair dyes in the last month (9.88 MN/1000 cells), in comparison with the MN in unexposed women (9.50 MN/1000 cells). No statistically significant differences in MN frequency were observed by type of hair dye or color of the hair dye. Comparison of subjects in the highest quartile of MN frequency (> or = 12 MN/1000 cells) and those in the lowest quartile (< or = 4 MN/1000 cells) suggested an association between hair dye use and elevated MN frequency (OR 14.2 (95% CI 0.81-247.8; P=0.069)). None of the polymorphisms examined significantly modified association between hair dye use and frequency of MN. Findings of an increased frequency of MN in urothelial cells of hair dye users suggest a possible genotoxic effect of hair dye compounds and need confirmation in larger studies. PMID:18262724

  19. Does exposure to glyphosate lead to an increase in the micronuclei frequency? A systematic and meta-analytic review.

    PubMed

    Ghisi, Nédia de Castilhos; de Oliveira, Elton Celton; Prioli, Alberto José

    2016-02-01

    Glyphosate-based herbicides are among the most used pesticides worldwide. Reviews on the safety of glyphosate have been conducted by several regulatory agencies and researches centers, many times with contradictory results. This study is a systematic meta-analytical review of experimental studies on the relationship between exposure to the glyphosate (GLY) and its formulations with the formation of micronuclei (MN) to establish a quantitative estimate of the environmental risks. The natural logarithm (ln) of the estimated response ratio was calculated from 81 experiments. A meta-analysis was performed on the complete data set, and individual meta-analyses were conducted after stratification by test system, class of vertebrate, exposure route, gender, endpoints, type of literature, formulation, GLY dose and exposure time. A forest plot showed an overall positive association between GLY exposure and its formulations and MN, corroborated by the cumulative effects size. Different responses were observed on mammalian and non-mammalian. Interesting results was noticed in exposure route where oral administration of GLY presented no significance. Exposure by intraperitoneal injection presented the highest MN formation. Pure GLY caused fewer effects than to commercial mixtures, but both presented mutagenic effects. The studies with males presented significant responses, while studies with females were not significant. The cumulative effects size was not clearly related to GLY dose, and was negatively related to exposure time. It can be attributed to different test systems, exposure routes and protocols analyzed. In conclusion, our results support the hypothesis that exposure to GLY and its formulations increases the frequency of MN formation. PMID:26688238

  20. Protective effects of antioxidants on micronuclei induced by irradiated 9-fluorenone/N,N-dimethyl-p-toluidine in CHO cells.

    PubMed

    Li, Yi-Ching; Huang, Fu-Mei; Lee, Shiuan-Shinn; Lin, Ruey-Hseng; Chou, Ming-Yung; Chang, Yu-Chao

    2008-01-01

    9-Fluorenone (9F), the aromatic photosensitizer, is widely used as an initiator in visible-light (VL) cured resin systems. There is growing concern that 9F may produce genetic damage by inducing mutation. In this study, 9F in the presence or absence of reducing agent N,N-dimethyl-p-toluidine (DMT) with or without VL irradiation was analyzed for the induction of chromosomal aberrations indicated by micronuclei (MN) induced in CHO cells. Our data demonstrated that a dose-related increase in the frequency of MN and prolonged cell cycles in 9F with or without DMT in the presence or absence of VL irradiation (p < 0.05). The rank orders with respect to genotoxicity and cytotoxicity were found to be as follows: 9F/DMT +VL > 9F/DMT = 9F + VL > 9F. To determine whether oxidative stress could modulate MN induced by 9F/DMT with or without VL irradiation in CHO cells, cells were pretreated with N-acetyl-L-cysteine (NAC), ascorbic acid, and alpha-tocopherol. The pretreatment with antioxidants could diminish not only the prolonged cell cycle but also the decreased frequency of MN which is induced by 9F with or without DMT in the presence or absence of VL irradiation in CHO cells (p < 0.05). Our findings provide the evidences for the induction of MN by 9F in the presence or absence of DMT with or without VL irradiation in CHO cells, indicating clastogenic activity of 9F/DMT in vitro. These antioxidants act as the antagonists against the genotoxicity and cytotoxicity of 9F/DMT. Thus, leaching photoinitiator and reducing agent might be contributing the sources of oxidative stress. PMID:17455275

  1. Comparative toxicity and micronuclei formation in Tribolium castaneum, Callosobruchus maculatus and Sitophilus oryzae exposed to high doses of gamma radiation.

    PubMed

    Ahmadi, Mehrdad; Mozdarani, Hossein; Abd-Alla, Adly M M

    2015-07-01

    The effects of gamma radiation on mortality and micronucleus formation in Tribolium castaneum Herbst, Callosobruchus maculatus (F.) and Sitophilus oryzae (L.) genital cells were evaluated. Two groups of healthy and active adult insects 1-3 and 8-10 days old were irradiated with various doses (50-200 Gy) gamma ray. Seven days post-irradiation; mortality rates and micronucleus formation were assessed in genital cells of the irradiated insects. The results show that with increasing gamma doses, the mortality rate of each species increased and T. castaneum and S. oryzae showed the low and high sensitivity respectively. It was shown that the micronucleus appearance in the tested insects had correlation with amount and intensity of radiation doses. Moreover our results indicate different levels in the genotoxicity of gamma radiation among the insects' genital cells under study. The frequency of micronuclei in genital cells of 1-3 days old insects exposed to 50 and 200 Gy were 12.6 and 38.8 Mn/1000 cells in T. castaneum, 20.8 and 46.8 Mn/1000 cells in C. maculatus and 16.8 and 57.2 Mn/1000 cells in S. oryzae respectively. A high sensitivity of the genital cells to irradiation exposure was seen in S. oryzae correlated with its high mortality rate compared with the other two species. These results might be indicative of inflicting chromosomal damage expressed as micronucleus in high mortality rates observed in the pest population; an indication of genotoxic effects of radiation on the studied species. PMID:25898238

  2. Increased Frequency of Micronuclei in Adults with a History of Childhood Sexual Abuse: A Discordant Monozygotic Twin Study

    PubMed Central

    York, Timothy P.; Brumelle, Jenni; Juusola, Jane; Kendler, Kenneth S.; Eaves, Lindon J.; Amstadter, Ananda B.; Aggen, Steven H.; Jones, Kimberly H.; Ferreira-Gonzalez, Andrea; Jackson-Cook, Colleen

    2013-01-01

    Background Childhood sexual abuse (CSA) is a traumatic life event associated with an increased lifetime risk for psychopathology/morbidity. The long-term biological consequences of CSA-elicited stress on chromosomal stability in adults are unknown. The primary aim of this study was to determine if the rate of acquired chromosomal changes, measured using the cytokinesis-block micronucleus assay on stimulated peripheral blood lymphocytes, differs in adult female monozygotic twins discordant for CSA. Methods Monozygotic twin pairs discordant for CSA were identified from a larger population-based sample of female adult twins for whom the experience of CSA was assessed by self-report (51 individuals including a reference sample). Micronuclei (MN) contain chromatin from structurally normal or abnormal chromosomes that are excluded from the daughter nuclei during cell division and serve as a biomarker to assess acquired chromosomal instability. Results Female twins exposed to CSA exhibited a 1.63-fold average increase in their frequency of MN compared to their nonexposed genetically identical cotwins (Paired t-test, t16 = 2.65, P = 0.017). No additional effects of familial factors were detected after controlling for the effect of CSA exposure. A significant interaction between CSA history and age was observed, suggesting that the biological effects of CSA on MN formation may be cumulative. Conclusions These data support a direct link between CSA exposure and MN formation measured in adults that is not attributable to genetic or environmental factors shared by siblings. Further research is warranted to understand the biological basis for the observed increase in acquired chromosomal findings in people exposed to CSA and to determine if acquired somatic chromosomal abnormalities/somatic clonal mosaicism might mediate the adult pathology associated with CSA. PMID:23383158

  3. Increased micronuclei and bulky DNA adducts in cord blood after maternal exposures to traffic-related air pollution.

    PubMed

    Pedersen, M; Wichmann, J; Autrup, H; Dang, D A; Decordier, I; Hvidberg, M; Bossi, R; Jakobsen, J; Loft, S; Knudsen, L E

    2009-11-01

    Exposure to traffic-related air pollution in urban environment is common and has been associated with adverse human health effects. In utero exposures that result in DNA damage may affect health later in life. Early effects of maternal and in utero exposures to traffic-related air pollution were assessed through the use of validated biomarkers in blood cells from mother-newborn pairs. A cross-sectional biomonitoring study with healthy pregnant women living in the Greater Copenhagen area, Denmark, was conducted. Bulky DNA adducts and micronuclei (MN) were measured in blood from 75 women and 69 umbilical cords, concurrently collected at the time of planned Caesarean section. Modeled residential traffic density, a proxy measure of traffic-related air pollution exposures, was validated by indoor levels of nitrogen dioxide and polycyclic aromatic hydrocarbons in 42 non-smoking homes. DNA adduct levels were similar and positively correlated in maternal and cord blood (1.40 vs. 1.37 n/10(8) nucleotides; r=0.99; p<0.01). Maternal MN frequencies were significantly associated with age (p<0.01), and higher than those of the newborns (7.0 vs. 3.2 MN per 1000 binucleated cells). Adduct levels were highest among mother-newborn pairs who lived near medium-traffic-density (>400-2500 vehicle km/24h; p<0.01) places. MN frequencies among newborns from women who lived at high-traffic-density homes (>2500 vehicle km/24h) were significantly increased (p=0.02). This trend remained after adjusting for potential confounders and effect modifiers. For the first time increased bulky DNA adducts and MN in cord blood after maternal exposures to traffic-related air pollution are found, demonstrating that these transplacental environmental exposures induce DNA damage in newborns. Given that increased DNA damage early in life indicate an increased risk for adverse health effects later in life, these findings justify intervention of pregnant women. PMID:19783246

  4. Effects of Arbutin on Radiation-Induced Micronuclei in Mice Bone Marrow Cells and Its Definite Dose Reduction Factor

    PubMed Central

    Nadi, Saba; Monfared, Ali Shabestani; Mozdarani, Hossein; Mahmodzade, Aziz; Pouramir, Mahdi

    2016-01-01

    Background: Interactions of free radicals from ionizing radiation with DNA can induce DNA damage and lead to mutagenesis and carsinogenesis. With respect to radiation damage to human, it is important to protect humans from side effects induced by ionizing radiation. In the present study, the effects of arbutin were investigated by using the micronucleus test for anti-clastogenic activity, to calculate the ratio of polychromatic erythrocyte to polychromatic erythrocyte plus normochromatic erythrocyte (PCE/PCE+NCE) in order to show cell proliferation activity. Methods: Arbutin (50, 100, and 200 mg/kg) was intraperitoneally (ip)administered to NMRI mice two hours before gamma radiation at 2 and 4 gray (Gy). The frequency of micronuclei in 1000 PCEs (MnPCEs) and the ratio of PCE/PCE+NCE were calculated for each sample. Data were statistically evaluated using one-way ANOVA, Tukey HSD test, and t-test. Results: The findings indicated that gamma radiation at 2 and 4 Gy extremely increased the frequencies of MnPCE (P<0.001) while reducing PCE/PCE+NCE (P<0.001) compared to the control group. All three doses of arbutin before irradiation significantly reduced the frequencies of MnPCEs and increased the ratio of PCE/PCE+NCE in mice bone marrow compared to the non-drug-treated irradiated control (P<0.001). All three doses of arbutin had no toxicity effect on bone marrow cells. The calculated dose reduction factor (DRF) showed DRF=1.93 for 2Gy and DRF=2.22 for 4 Gy. Conclusion: Our results demonstrated that arbutin gives significant protection to rat bone against the clastogenic and cytotoxic effects of gamma irradiation. PMID:27217601

  5. Genotoxic and mutagenic effects of permethrin in mice: micronuclei analysis in peripheral blood erythrocytes.

    PubMed

    Roma, Gislaine Cristina; de Oliveira, Patrícia Rosa; Araujo, Andrea Mendez; Bechara, Gervásio Henrique; Mathias, Maria Izabel Camargo

    2012-12-01

    Pyrethroids such as permethrin are synthetic compounds widely used in the agriculture of many countries to combat plagues and in domestic products, such as acaricides. Not so long ago these chemicals were characterized as non-toxic for non-target organisms; however, recent studies have showed that these compounds could present toxic potential for many organisms. In this sense, this study presents genotoxic and mutagenic potential of permethrin administered intraperitoneally in mice under artificial conditions by the use of micronucleus assay in the peripheral blood of these animals. The mice were divided into five groups: group I = negative control (distilled water), group II = positive control (cyclophosphamide), group III = 30% of permethrin LD(50) (96 mg/kg), group IV = 50% of permethrin LD(50) (160 mg/kg), and group V = 80% of permethrin LD(50) (256 mg/kg). The peripheral blood was collected 24, 48, and 72 h after treatment. Results showed that all the tested permethrin dosages presented genotoxic and mutagenic effects 24 h after treatment, which would contradict the classification of this chemical product as moderately toxic, i.e., unable to cause damages to the cell DNA. PMID:22965619

  6. Pharmacological inhibition of Polo Like Kinase 2 (PLK2) does not cause chromosomal damage or result in the formation of micronuclei

    SciTech Connect

    Fitzgerald, Kent; Bergeron, Marcelle; Willits, Christopher; Bowers, Simeon; Aubele, Danielle L.; Goldbach, Erich; Tonn, George; Ness, Daniel; Olaharski, Andrew

    2013-05-15

    Polo Like Kinase 2 (PLK2) phosphorylates α-synuclein and is considered a putative therapeutic target for Parkinson's disease. Several lines of evidence indicate that PLK2 is involved with proper centriole duplication and cell cycle regulation, inhibition of which could impact chromosomal integrity during mitosis. The objectives of the series of experiments presented herein were to assess whether specific inhibition of PLK2 is genotoxic and determine if PLK2 could be considered a tractable pharmacological target for Parkinson's disease. Several selective PLK2 inhibitors, ELN 582175 and ELN 582646, and their inactive enantiomers, ELN 582176 and ELN 582647, did not significantly increase the number of micronuclei in the in vitro micronucleus assay. ELN 582646 was administered to male Sprague Dawley rats in an exploratory 14-day study where flow cytometric analysis of peripheral blood identified a dose-dependent increase in the number of micronucleated reticulocytes. A follow-up investigative study demonstrated that ELN 582646 administered to PLK2 deficient and wildtype mice significantly increased the number of peripheral micronucleated reticulocytes in both genotypes, suggesting that ELN 582646-induced genotoxicity is not through the inhibition of PLK2. Furthermore, significant reduction of retinal phosphorylated α-synuclein levels was observed at three non-genotoxic doses, additional data to suggest that pharmacological inhibition of PLK2 is not the cause of the observed genotoxicity. These data, in aggregate, indicate that PLK2 inhibition is a tractable CNS pharmacological target that does not cause genotoxicity at doses and exposures that engage the target in the sensory retina. - Highlights: • Active and inactive enantiomers test negative in the in vitro micronucleus test. • ELN 582646 significantly increased micronuclei at 100 and 300 mg/kg/day doses. • ELN 582646 significantly increased micronuclei in PLK2 knockout mice. • ELN 582646 decreased

  7. Stress induced by premature chromatin condensation triggers chromosome shattering and chromothripsis at DNA sites still replicating in micronuclei or multinucleate cells when primary nuclei enter mitosis.

    PubMed

    Terzoudi, Georgia I; Karakosta, Maria; Pantelias, Antonio; Hatzi, Vasiliki I; Karachristou, Ioanna; Pantelias, Gabriel

    2015-11-01

    Combination of next-generation DNA sequencing, single nucleotide polymorphism array analyses and bioinformatics has revealed the striking phenomenon of chromothripsis, described as complex genomic rearrangements acquired in a single catastrophic event affecting one or a few chromosomes. Via an unproven mechanism, it is postulated that mechanical stress causes chromosome shattering into small lengths of DNA, which are then randomly reassembled by DNA repair machinery. Chromothripsis is currently examined as an alternative mechanism of oncogenesis, in contrast to the present paradigm that considers a stepwise development of cancer. While evidence for the mechanism(s) underlying chromosome shattering during cancer development remains elusive, a number of hypotheses have been proposed to explain chromothripsis, including ionizing radiation, DNA replication stress, breakage-fusion-bridge cycles, micronuclei formation and premature chromosome compaction. In the present work, we provide experimental evidence on the mechanistic basis of chromothripsis and on how chromosomes can get locally shattered in a single catastrophic event. Considering the dynamic nature of chromatin nucleoprotein complex, capable of rapid unfolding, disassembling, assembling and refolding, we first show that chromatin condensation at repairing or replicating DNA sites induces the mechanical stress needed for chromosome shattering to ensue. Premature chromosome condensation is then used to visualize the dynamic nature of interphase chromatin and demonstrate that such mechanical stress and chromosome shattering can also occur in chromosomes within micronuclei or asynchronous multinucleate cells when primary nuclei enter mitosis. Following an aberrant mitosis, chromosomes could find themselves in the wrong place at the wrong time so that they may undergo massive DNA breakage and rearrangement in a single catastrophic event. Specifically, our results support the hypothesis that premature chromosome

  8. Assessment of in vivo genotoxicity of the rodent carcinogen furan: evaluation of DNA damage and induction of micronuclei in mouse splenocytes.

    PubMed

    Leopardi, Paola; Cordelli, Eugenia; Villani, Paola; Cremona, Tiziana Patrizia; Conti, Luigi; De Luca, Gabriele; Crebelli, Riccardo

    2010-01-01

    In recent years, several surveys have highlighted the presence of the rodent carcinogen furan in a variety of food items. Even though the evidence of carcinogenicity of furan is unequivocal, the underlying mechanism has not been fully elucidated. In particular, the role of genotoxicity in furan carcinogenicity is still not clear, even though this information is considered pivotal for the assessment of the risk posed by the presence of low doses of furan in food. In this work, the genotoxic potential of furan in vivo has been investigated in mice, under exposure conditions similar to those associated with cancer onset in the National Toxicology Program long-term bioassay. To this aim, male B6C3F1 mice were treated by gavage for 4 weeks with 2, 4, 8 and 15 mg furan/kg b.w./day. Spleen was selected as the target organ for genotoxicity assessment, in view of the capability of quiescent splenocytes to accumulate DNA damage induced by repeat dose exposure. The induction of primary DNA damage in splenocytes was evaluated by alkaline single-cell gel electrophoresis (comet assay) and by the immunofluorescence detection of foci of phosphorylated histone H2AX (gamma-H2AX). The presence of cross-links was probed in a modified comet assay, in which cells were irradiated in vitro with gamma-rays before electrophoresis. Chromosome damage was quantitated through the detection of micronuclei in mitogen-stimulated splenocytes using the cytokinesis-block method. Micronucleus induction was also assessed with a modified protocol, using the repair inhibitor 1-beta-arabinofuranosyl-cytosine to convert single-strand breaks in micronuclei. The results obtained show a significant (P < 0.01) increase of gamma-H2AX foci in mitogen-stimulated splenocytes of mice treated with 8 and 15 mg furan/kg b.w. and a statistically significant (P < 0.001) increases of micronuclei in binucleated splenocytes cultured in vitro. Conversely, no effect of in vivo exposure to furan was observed when freshly

  9. Validation of a flow cytometric acridine orange micronuclei methodology in rats.

    PubMed

    Criswell, K A; Krishna, G; Zielinski, D; Urda, G A; Juneau, P; Bulera, S; Bleavins, M R

    2003-07-25

    Our laboratory has previously reported a flow cytometric acridine orange method for detection of micronucleus (MN) in the rat using cyclophosphamide as a test compound. To replace the manual method of scoring and satisfy Good Laboratory Practice (GLP) requirements, an extensive validation of the flow method was required. Therefore, manual scoring and flow cytometric determination of MN were compared using vincristine, chlorambucil, methotrexate, and doxorubicin compounds known to induce MN formation with various mechanisms of action. 1,2-Dimethylhydrazine (1,2-DH), a compound with negative or equivocal MN findings also was evaluated. The flow method consistently demonstrated dose- and time-dependent responses for MN production at all concentrations of vincristine, methotrexate, clorambucil, and doxorubicin. In contrast, manual scoring of slides failed to detect an increase in MN at the lowest doses of doxorubicin (1mg/kg) at 24 or 48 h, and methotrexate at 48 h, or any dose of methotrexate (50, 100, or 250 mg/kg) at 24h. Additionally, a dose-response for methotrexate at 48 h, and chlorambucil at 24 h were missed using manual scoring. For 1,2-DH, the flow method showed a low level (< 1.4-fold) increase in MN at all doses and times. In contrast, the manual method showed five-seven-fold increases at 24 h, but a < two-fold increase at 48 h in the highest dose only. These data may suggest that the flow method has a greater sensitivity and possibly accuracy than manual scoring. Significant decreases in polychromatic erythrocytes (PCE) were seen using both methods at approximately the same dose for all compounds. However, absolute flow cytometric PCE values were consistently higher than manual. Additional cytotoxicity parameters obtained by the flow method allowed a more complete assessment of cytotoxicity than PCE alone. Furthermore, data reported here combined with improved throughput, shortened data turnaround and reporting times, and possibly better precision due to

  10. A comparison of lymphocyte micronuclei and plasma micronutrients in vegetarians and non-vegetarians.

    PubMed

    Fenech, M; Rinaldi, J

    1995-02-01

    We performed a biochemical and cytogenetic epidemiological study to establish if there are significant differences between vegetarians (V) and non-vegetarians (NV) in their peripheral blood lymphocyte micronucleus (MN) index, which is a measure of chromosome damage rate. The levels of plasma vitamin C (VIT-C), vitamin E (VIT-E), vitamin B12 (B12) and folic acid were also analysed to assess if differences in chromosome damage rates were associated with these potentially antimutagenic micronutrients. Volunteers were classified as either 'vegetarian' if they had abstained from eating any flesh foods for at least 3 years prior to the study or 'non-vegetarian' if they consumed meat or meat products at least 5 days/week for at least 3 years before participation in the study. The volunteers in the study consisted of 47 male and 79 female V and 66 male and 72 female NV, all of whom were non-smokers for at least 3 years prior to the study. The age of the volunteers varied between 20 and 89 years. There was no significant difference in the slope of the age-related increase in MN index of V and NV of either sex. However, the MN index was significantly lower in NV males in the age group 20-40 years and significantly lower for V males in the 41-60 years age group. No difference between the MN index of older males was detectable and there also was no difference in the MN index of V and NV females across all age groups. V were generally found to have significantly higher plasma levels of VIT-C and folic acid, significantly lower levels of B12, and similar levels of VIT-E when compared with NV. VIT-C correlated positively with MN index in young males, but the reverse was true for B12. In young females folate and B12 appeared to correlate negatively with MN index. VIT-E had no apparent impact on MN index. These data suggest that the level of folate and B12 may be more important than VIT-C or VIT-E in minimizing chromosome damage rates in human lymphocytes. Overall, the data from

  11. Ionizing radiation or mitomycin-induced micronuclei in lymphocytes of BRCA1 or BRCA2 mutation carriers.

    PubMed

    Gutiérrez-Enríquez, Sara; Ramón Y Cajal, Teresa; Alonso, Carmen; Corral, Anna; Carrasco, Pablo; Cornet, Mónica; Sanz, Judith; Ribas, Montserrat; Baiget, Montserrat; Diez, Orland

    2011-06-01

    BRCA1 and BRCA2 genes are essential in preserving the integrity of genome, and it is not unambiguously clear whether the heterozygosity status may affect BRCA1 or BRCA2 functions. This may have implications for the clinical management of BRCA1 and BRCA2 mutation carriers both in breast cancer (BC) screening modality and in cancer treatment based on DNA-damaging or DNA-repair-inhibiting drugs. We investigated whether lymphocytes carrying BRCA1 or BRCA2 mutations displayed an increased sensitivity to radiation or mitomycin C (MMC) in vitro treatments. Peripheral blood from 21 BRCA1 mutation carriers (12 with BC and 9 healthy), 24 BRCA2 carriers (13 with BC and 11 healthy), 15 familial BC patients without detected mutation in BRCA1 or BRCA2 and 16 controls without familial history of cancer (5 with BC and 11 healthy) were irradiated or treated with MMC. Chromosomal damage was measured using the cytokinesis-block micronucleus assay. We evaluated micronuclei (MN) and nucleoplasmic bridges (NPBs). The BRCA2 mutation carriers and familial BC patients without detected mutation in BRCA1 or BRCA2 showed less basal NPB than BRCA1 carriers and controls. The BRCA1 (+/-) or BRCA2 (+/-) lymphocytes did not have increased frequencies of MN or NPB after irradiation. In contrast, BRCA2 (+/-) lymphocytes presented higher levels of MN after MMC exposure than BRCA1 carriers and controls. The monoallelic BRCA1 or BRCA2 pathogenic mutations seem not to be associated with an enhanced radiosensitivity. The mutation of one BRCA2 allele conferred an increased sensitivity to MMC, presumably because of the role of this gene in the repair of MMC-induced DNA damage. This finding indicates that the MMC-induced MN analysis could be useful in identifying functional deficiencies of BRCA2 or genes related to BRCA2. Since MMC can be used as an anti-cancer drug, these data may be relevant for the management and follow-up of BRCA2 mutation carriers. PMID:20625817

  12. Energy-dependent RBE of neutrons to induce micronuclei in root-tip cells of Allium cepa onion irradiated as dry dormant seeds and seedlings.

    PubMed

    Zhang, Wenyi; Fujikawa, Kazuo; Endo, Satoru; Ishikawa, Masayori; Ohtaki, Megu; Ikeda, Hideo; Hoshi, Masaharu

    2003-06-01

    The relative biological effectiveness (RBE) of various energy neutrons produced from a Schenkel-type accelerator at the Research Institute for Radiation Biology and Medicine, Hiroshima University (HIRRAC), compared with 60Co gamma-ray radiation was determined. The neutron radiations and gamma-ray radiation produced good linear changes in the frequency of micronuclei induced in the root-tip cells of Allium cepa onion irradiated as dry dormant seeds (seed assay) and seedlings (seedling assay) with varying radiation doses. Therefore the RBE for radiation-induced micronuclei can be calculated as the ratio of the slopes of the fitted linear dose response for the neutron radiations and the 60Co gamma-ray radiation. The RBE values by seed assay and seedling assay decreased to 174 +/- 7, from 216 +/- 9, and to 31.4 +/- 1.0, from 45.3 +/- 1.3 (one standard error), respectively, when neutron energies increased to 1.0 MeV, from 0.2 MeV, in the present study. Furthermore, the ratio of the micronucleus induction rates of seed assay to seedling assay by gamma-ray radiation was much lower than that by neutron radiations. PMID:13678347

  13. A Case-Control Study of Oral Epithelial Proliferative Markers among Sudanese Toombak Dippers Using Micronuclei Assay, Argyrophilic Nucleolar Organizer Region, Papanicolaou and Crystal Violet Methods

    PubMed Central

    Anass, M. Abbas; G. Ahmed, Hussain

    2013-01-01

    The use of Toombak has been reported to play a major role in the etiology of oral cancer in Sudan. The cellular proliferative activity on the oral epithelium of 210 Toombak dippers was assessed by applying the micronuclei frequency, mean argyrophilic nucleolar organizer region (AgNOR) counts, Papanicolaou method, and 1% crystal violet stain. Participants were divided into 3 groups: 200 were apparently healthy individuals, 100 were Toombak users (cases), 100 were non-tobacco users (control) and 10 were patients with oral squamous cell carcinomas. Cytological atypia was identified among 4 (4%). Toombak users and was not found among the control group (P<0.04). The micronuclei frequencies were higher in Toombak users (1.026) than in the control group (0.356) (P<0.0001). The mean AgNOR counts in Toombak users (2.423) were higher than control group (1.303) (P<0.0001). Neither Toombak users nor control group showed mitotic figures in 1% crystal violet method. The results of this research showed that Toombak dipping is a high risk factor for increase in the cellular proliferation in the oral mucosa. The cytological proliferative marker methods used are useful for screening Toombak users. PMID:24179643

  14. Effects of folic acid deficiency and MTHFR C677T polymorphism on spontaneous and radiation-induced micronuclei in human lymphocytes.

    PubMed

    Leopardi, Paola; Marcon, Francesca; Caiola, Stefania; Cafolla, Arturo; Siniscalchi, Ester; Zijno, Andrea; Crebelli, Riccardo

    2006-09-01

    Folic acid plays a key role in the maintenance of genomic stability, providing methyl groups for the conversion of uracil to thymine and for DNA methylation. Besides dietary habits, folic acid metabolism is influenced by genetic polymorphism. The C677T polymorphism of the methylene-tetrahydrofolate reductase (MTHFR) gene is associated with a reduction of catalytic activity and is suggested to modify cancer risk differently depending on folate status. In this work the effect of folic acid deficiency on genome stability and radiosensitivity has been investigated in cultured lymphocytes of 12 subjects with different MTHFR genotype (four for each genotype). Cells were grown for 9 days with 12, 24 and 120 nM folic acid and analyzed in a comprehensive micronucleus test coupled with centromere characterization by CREST immunostaining. In other experiments, cells were grown with various folic acid concentrations, irradiated with 0.5 Gy of gamma rays and analyzed in the micronucleus test. The results obtained indicate that folic acid deficiency induces to a comparable extent chromosome loss and breakage, irrespective of the MTHFR genotype. The effect of folic acid was highly significant (P < 0.001) and explained >50% of variance of both types of micronuclei. Also nucleoplasmic bridges and buds were significantly increased under low folate supply; the increase in bridges was mainly observed in TT cells, highlighting a significant effect of the MTHFR genotype (P = 0.006) on this biomarker. Folic acid concentration significantly affected radiation-induced micronuclei (P < 0.001): the increased incidence of radiation-induced micronuclei with low folic acid was mainly accounted for by carriers of the variant MTHFR allele (both homozygotes and heterozygotes), but the overall effect of genotype did not attain statistical significance. Treatment with ionizing radiations also increased the frequency of nucleoplasmic bridges. The effect of folic acid level on this end-point was

  15. Bilirubin UDP-Glucuronosyltransferase 1A1 (UGT1A1) Gene Promoter Polymorphisms and HPRT, Glycophorin A, and Micronuclei Mutant Frequencies in Human Blood

    SciTech Connect

    Grant, D; Hall, I J; Eastmond, D; Jones, I M; Bell, D A

    2004-10-06

    A dinucleotide repeat polymorphism (5-, 6-, 7-, or 8-TA units) has been identified within the promoter region of UDP-glucuronosyltransferase 1A1 gene (UGT1A1). The 7-TA repeat allele has been associated with elevated serum bilirubin levels that cause a mild hyperbilirubinemia (Gilbert's syndrome). Studies suggest that promoter transcriptional activity of UGT1A1 is inversely related to the number of TA repeats and that unconjugated bilirubin concentration increases directly with the number of TA repeat elements. Because bilirubin is a known antioxidant, we hypothesized that UGT1A1 repeats associated with higher bilirubin may be protective against oxidative damage. We examined the effect of UGT1A1 genotype on somatic mutant frequency in the hypoxanthine-guanine phosphoribosyl-transferase (HPRT) gene in human lymphocytes and the glycophorin A (GPA) gene of red blood cells (both N0, NN mutants), and the frequency of lymphocyte micronuclei (both kinetochore (K) positive or micronuclei K negative) in 101 healthy smoking and nonsmoking individuals. As hypothesized, genotypes containing 7-TA and 8-TA displayed marginally lower GPA{_}NN mutant frequency relative to 5/5, 5/6, 6/6 genotypes (p<0.05). In contrast, our analysis showed that lower expressing UGT1A1 alleles (7-TA and 8-TA) were associated with modestly increased HPRT mutation frequency (p<0.05) while the same low expression genotypes were not significantly associated with micronuclei frequencies (K-positive or K-negative) when compared to high expression genotypes (5-TA and 6-TA). We found weak evidence that UGT1A1 genotypes containing 7-TA and 8-TA were associated with increased GPA{_}N0 mutant frequency relative to 5/5, 5/6, 6/6 genotypes (p<0.05). These data suggest that UGT1A1 genotype may modulate somatic mutation of some types, in some cell lineages, by a mechanism not involving bilirubin antioxidant activity. More detailed studies examining UGT1A1 promoter variation, oxidant/antioxidant balance and genetic

  16. Induction of micronuclei and nuclear abnormalities by cyclophosphamide and colchicine in Xenotoca melanosoma (Pisces, Goodeidae) from Lake La Alberca in Michoacan, Mexico.

    PubMed

    Zavala-Aguirre, Jose Luis; Torres-Bugarin, Olivia; Buelna-Osben, Hector Rene; Flores-Kehn, Lola Paulina; Ramos-Ibarra, Maria Luisa; Zuniga-Gonzalez, Guillermo; Ogura, Tetsuya

    2010-01-01

    This study is a follow-up of previous research in which we described the frequency of spontaneous micronucleated erythrocytes (MNE) in the Goodeid Xenotocoa melanosoma collected from Lake La Alberca, located in the state of Michoacan, Mexico. In the present work, we measured micronuclei (MN) and nuclear abnormalities (NA) in erythrocytes of peripheral blood. Bioassays taken at 24 or 96 hours in either the cyclophosfamide (CP) or colchicine (COL) showed a significant increase in MN and BC (P values ranging from 0.0499 to 0.0036) compared with information from wild organisms collected over 3 years. Concentrationdependent and time-dependent responses support the proposal of using endemic Xenotoca melanosoma as a bioindicator of genotoxicity and cytotoxicity with a high transcendence for the health of the entire ecosystem and evaluation of the Lerma-Chapala watershed. PMID:20390845

  17. Lack of DNA polymerase theta (POLQ) radiosensitizes bone marrow stromal cells in vitro and increases reticulocyte micronuclei after total-body irradiation.

    PubMed

    Goff, Julie P; Shields, Donna S; Seki, Mineaki; Choi, Serah; Epperly, Michael W; Dixon, Tracy; Wang, Hong; Bakkenist, Christopher J; Dertinger, Stephen D; Torous, Dorothea K; Wittschieben, John; Wood, Richard D; Greenberger, Joel S

    2009-08-01

    Abstract Mammalian POLQ (pol theta) is a specialized DNA polymerase with an unknown function in vivo. Roles have been proposed in chromosome stability, as a backup enzyme in DNA base excision repair, and in somatic hypermutation of immunoglobulin genes. The purified enzyme can bypass AP sites and thymine glycol. Mice defective in POLQ are viable and have been reported to have elevated spontaneous and radiation-induced frequencies of micronuclei in circulating red blood cells. To examine the potential roles of POLQ in hematopoiesis and in responses to oxidative stress responses, including ionizing radiation, bone marrow cultures and marrow stromal cell lines were established from Polq(+/+) and Polq(-/-) mice. Aging of bone marrow cultures was not altered, but Polq(-/-) cells were more sensitive to gamma radiation than were Polq(+/+) cells. The D(0) was 1.38 +/- 0.06 Gy for Polq(+/+) cells compared to 1.27 +/- 0.16 and 0.98 +/- 0.10 Gy (P = 0.032) for two Polq(-/-) clones. Polq(-/-) cells were moderately more sensitive to bleomycin than Polq(+/+) cells and were not hypersensitive to paraquat or hydrogen peroxide. ATM kinase activation appeared to be normal in gamma-irradiated Polq(-/-) cells. Inhibition of ATM kinase activity increased the radiosensitivity of Polq(+/+) cells slightly but did not affect Polq(-/-) cells. Polq(-/-) mice had more spontaneous and radiation-induced micronucleated reticulocytes than Polq+/+ and (+/-) mice. The sensitivity of POLQ-defective bone marrow stromal cells to ionizing radiation and bleomycin and the increase in micronuclei in red blood cells support a role for this DNA polymerase in cellular tolerance of DNA damage that can lead to double-strand DNA breaks. PMID:19630521

  18. 'BioQuaRT' project: design of a novel in situ protocol for the simultaneous visualisation of chromosomal aberrations and micronuclei after irradiation at microbeam facilities.

    PubMed

    Patrono, C; Monteiro Gil, O; Giesen, U; Langner, F; Pinto, M; Rabus, H; Testa, A

    2015-09-01

    The aim of the 'BioQuaRT' (Biologically weighted Quantities in RadioTherapy) project is to develop measurement techniques for characterising charged particle track structure on different length scales, and to correlate at the cellular level the track structure properties with the biological effects of radiation. This multi-scale approach will allow characterisation of the radiation qualities used in radiotherapy and the related biological effects. Charged-particle microbeam facilities were chosen as the platforms for all radiobiology experiments in the 'BioQuaRT' project, because they allow targeting single cells (or compartments of a cell) with a predefined number of ionising particles and correlating the cell-by-cell induced damage with type and energy of the radiation and with the number of ions per cell. Within this project, a novel in situ protocol was developed for the analysis of the misrepaired and/or unrepaired chromosome damage induced by charged-particle irradiations at the Physikalisch-Technische Bundesanstalt (PTB) ion microbeam facility. Among the cytogenetic biomarkers to detect and estimate radiation-induced DNA damage in radiobiology, chromosomal aberrations and micronuclei were chosen. The characteristics of the PTB irradiation system required the design of a special in situ assay: specific irradiation dishes with a base made from a biofoil 25-µm thick and only 3000-4000 cells seeded and irradiated per dish. This method was developed on Chinese hamster ovary (CHO) cells, one of the most commonly used cell lines in radiobiology in vitro experiments. The present protocol allows the simultaneous scoring of chromosome aberrations and micronuclei on the same irradiated dish. Thanks to its versatility, this method could also be extended to other radiobiological applications besides the single-ion microbeam irradiations. PMID:25877532

  19. Double minute chromosomes in acute myeloid leukemia, myelodysplastic syndromes, and chronic myelomonocytic leukemia are associated with micronuclei, MYC or MLL amplification, and complex karyotype.

    PubMed

    Huh, Yang O; Tang, Guilin; Talwalkar, Sameer S; Khoury, Joseph D; Ohanian, Maro; Bueso-Ramos, Carlos E; Abruzzo, Lynne V

    2016-01-01

    Double minute chromosomes (dmin) are small, paired chromatin bodies that lack a centromere and represent a form of extrachromosomal gene amplification. Dmin are rare in myeloid neoplasms and are generally associated with a poor prognosis. Most studies of dmin in myeloid neoplasms are case reports or small series. In the current study, we present the clinicopathologic and cytogenetic features of 22 patients with myeloid neoplasms harboring dmin. These neoplasms included acute myeloid leukemia (AML) (n = 18), myelodysplastic syndrome (MDS) (n = 3), and chronic myelomonocytic leukemia (CMML) (n = 1). The AML cases consisted of AML with myelodysplasia-related changes (n = 13) and therapy-related AML (n = 5). Dmin were detected in initial pre-therapy samples in 14 patients with AML or CMML; they were acquired during the disease course in 8 patients who had AML or MDS. The presence of dmin was associated with micronuclei (18/18; 100%), complex karyotype (17/22; 77.3%), and amplification of MYC (12/16; 75%) or MLL (4/16; 25%). Immunohistochemical staining for MYC performed on bone marrow core biopsy or clot sections revealed increased MYC protein in all 19 cases tested. Except for one patient, most patients failed to respond to risk-adapted chemotherapies. At last follow up, all patients had died of disease after a median of 5 months following dmin detection. In conclusion, dmin in myeloid neoplasms commonly harbor MYC or MLL gene amplification and manifest as micronuclei within leukemic blasts. Dmin are often associated with myelodysplasia or therapy-related disease, and complex karyotypes. PMID:27318442

  20. Effect of Dose Rate on Residual γ-H2AX Levels and Frequency of Micronuclei in X-Irradiated Mouse Lymphocytes

    PubMed Central

    Turner, H. C.; Shuryak, I.; Taveras, M.; Bertucci, A.; Perrier, J. R.; Chen, C.; Elliston, C. D.; Johnson, G. W.; Smilenov, L. B.; Amundson, S. A.; Brenner, D. J.

    2015-01-01

    The biological risks associated with low-dose-rate (LDR) radiation exposures are not yet well defined. To assess the risk related to DNA damage, we compared the yields of two established biodosimetry end points, γ-H2AX and micronuclei (MNi), in peripheral mouse blood lymphocytes after prolonged in vivo exposure to LDR X rays (0.31 cGy/min) vs. acute high-dose-rate (HDR) exposure (1.03 Gy/min). C57BL/6 mice were total-body irradiated with 320 kVP X rays with doses of 0, 1.1, 2.2 and 4.45 Gy. Residual levels of total γ-H2AX fluorescence in lymphocytes isolated 24 h after the start of irradiation were assessed using indirect immunofluorescence methods. The terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was used to determine apoptotic cell frequency in lymphocytes sampled at 24 h. Curve fitting analysis suggested that the dose response for γ-H2AX yields after acute exposures could be described by a linear dependence. In contrast, a linear-quadratic dose-response shape was more appropriate for LDR exposure (perhaps reflecting differences in repair time after different LDR doses). Dose-rate sparing effects (P < 0.05) were observed at doses ≤2.2 Gy, such that the acute dose γ-H2AX and TUNEL-positive cell yields were significantly larger than the equivalent LDR yields. At the 4.45 Gy dose there was no difference in γ-H2AX expression between the two dose rates, whereas there was a two- to threefold increase in apoptosis in the LDR samples compared to the equivalent 4.45 Gy acute dose. Micronuclei yields were measured at 24 h and 7 days using the in vitro cytokinesis-blocked micronucleus (CBMN) assay. The results showed that MNi yields increased up to 2.2 Gy with no further increase at 4.45 Gy and with no detectable dose-rate effect across the dose range 24 h or 7 days post exposure. In conclusion, the γ-H2AX biomarker showed higher sensitivity to measure dose-rate effects after low-dose LDR X rays compared to MNi formation; however

  1. Modulatory of effect of fresh Amaranthus caudatus and Amaranthus hybridus aqueous leaf extracts on detoxify enzymes and micronuclei formation after exposure to sodium arsenite.

    PubMed

    Adewale, Adetutu; Olorunju, Awe Emmanuel

    2013-10-01

    Vegetables are the cheapest and most available sources of important proteins, minerals, vitamins, and essential amino protein. These vegetables are commonly used in Africa for the treatment of illness. This study evaluated the protective effects of Amaranthus caudatus and A. hybridus against sodium arsenite-induced toxicity in rats. The effects of sodium arsenite and/or the plant extracts were assessed using bone marrow micronucleus assay and by measuring the activities of tumour maker enzymes such as gamma glutamyl transferase (GGT) and alkaline phosphatase (ALP) in white albino Wister rats. The study showed that sodium arsenite significantly (P < 0.05) induced the formation of micronucleated polychromatic erythrocytes and the activities of ALP and GGT when compared with control. The levels of white blood cell, hemoglobin, and lymphocyte count were altered in sodium arsenite fed rats and were reverted back to near normal levels in rats pretreated with the plant extracts. A. caudatus and A. hybridus showed significant role in protecting the detoxifying enzymes; also, A. caudatus has a more protective effect on reducing the micronuclei formation when compared with A. hybridus. This study suggests that A. caudatus and A. hybridus possess anticarcinogenic effect. PMID:24174825

  2. Modulatory of effect of fresh Amaranthus caudatus and Amaranthus hybridus aqueous leaf extracts on detoxify enzymes and micronuclei formation after exposure to sodium arsenite

    PubMed Central

    Adewale, Adetutu; Olorunju, Awe Emmanuel

    2013-01-01

    Vegetables are the cheapest and most available sources of important proteins, minerals, vitamins, and essential amino protein. These vegetables are commonly used in Africa for the treatment of illness. This study evaluated the protective effects of Amaranthus caudatus and A. hybridus against sodium arsenite-induced toxicity in rats. The effects of sodium arsenite and/or the plant extracts were assessed using bone marrow micronucleus assay and by measuring the activities of tumour maker enzymes such as gamma glutamyl transferase (GGT) and alkaline phosphatase (ALP) in white albino Wister rats. The study showed that sodium arsenite significantly (P < 0.05) induced the formation of micronucleated polychromatic erythrocytes and the activities of ALP and GGT when compared with control. The levels of white blood cell, hemoglobin, and lymphocyte count were altered in sodium arsenite fed rats and were reverted back to near normal levels in rats pretreated with the plant extracts. A. caudatus and A. hybridus showed significant role in protecting the detoxifying enzymes; also, A. caudatus has a more protective effect on reducing the micronuclei formation when compared with A. hybridus. This study suggests that A. caudatus and A. hybridus possess anticarcinogenic effect. PMID:24174825

  3. The effect of dietary estimates calculated using food frequency questionnaires on micronuclei formation in European pregnant women: a NewGeneris study.

    PubMed

    Vande Loock, Kim; Botsivali, Maria; Zangogianni, Marina; Anderson, Diana; Baumgartner, Adolph; Fthenou, Eleni; Chatzi, Leda; Marcos, Ricard; Agramunt, Sylvia; Namork, Ellen; Granum, Berit; Knudsen, Lisbeth E; Nielssen, Jeanette K S; Meltzer, Helle Margrete; Haugen, Margaretha; Kyrtopoulos, Soterios A; Decordier, Ilse; Plas, Gina; Roelants, Mathieu; Merlo, Franco; Kleinjans, Jos; Kogevinas, Manolis; Kirsch-Volders, Micheline

    2014-11-01

    The use of biomarkers of early genetic effects, predictive for cancer, such as micronuclei (MN) in lymphocytes, may help to investigate the association between diet and cancer. We hypothesised that the presence of mutagens in the diet may increase MN formation. A 'pooled' standardised analysis was performed by applying the same experimental protocol for the cytokinesis block micronucleus assay in 625 young healthy women after delivery from five European study populations (Greece, Denmark, UK, Spain and Norway). We assessed MN frequencies in mono- and binucleated T-lymphocytes (MNMONO and MNBN) and the cytokinesis blocked proliferation index using a semi-automated image analysis system. Food frequency questionnaires (FFQs) were used to estimate intake of fatty acids and a broad range of immunotoxic and genotoxic/carcinogenic compounds through the diet. Pooled difference based on delivery type revealed higher MNMONO frequencies in caesarean than in vaginal delivery (P = 0.002). Statistical analysis showed a decrease in MNMONO frequencies with increasing calculated omega-6 PUFA concentrations and a decrease in MNBN frequencies with increasing calculated omega-3 PUFA concentrations. The expected toxic compounds estimated by FFQs were not associated with MN formation in mothers after delivery. In pregnant women, an omega-3 and -6 rich diet estimated by FFQ is associated with lower MN formation during pregnancy and delivery. PMID:25296962

  4. Micronuclei in mouse skin cells following in vivo exposure to benzo(a)pyrene, 7,12-dimethylbenz(a)anthracene, chrysene, pyrene and urethane

    SciTech Connect

    Shuilin He ); Baker, R. )

    1991-01-01

    Detection of micronuclei (MN) in skin cells from HRA/Skh hairless mice treated with chemical or physical agents may prove informative in qualitative and quantitative studies of skin carcinogenesis. MN induction and cell survival were estimated in cytokinesis-blocked keratinocytes, cultured for 4 days in vitro, after a single topical dose of various organic compounds. Treatment with 7,12-dimethylbenz(a)anthracene (DMBA) resulted in maximal MN induction in cells removed from skin 12-24 hr after topical administration. Even in cells removed only 1 hr after DMBA treatment, a significant increase in MN was evident. However, to allow sufficient time for metabolic activation, a sampling time of 24 hr was adopted for all test substances. Dose-dependent increases in MN were observed with DMBA, benzo(a)pyrene, chrysene, and urethane. Increased numbers of micronucleated cells were detected at the lowest doses administered in the present study. Although reduced cell recovery occurred following exposure of mice to acetone, pyrene, and other chemicals, there was no evidence that cytotoxicity contributed to MN scored in keratinocytes. Moreover, the probable noncarcinogen, pyrene, failed to induce MN at doses from 2.5 {mu}g to 2.5 mg/mouse. These results show that it is possible to assess chemical exposure in skin by measuring cell survival and skin genotoxicity by measuring MN induction in cultured keratinocytes.

  5. The effect of in vivo resveratrol supplementation in irradiated mice on the induction of micronuclei in peripheral blood and bone marrow reticulocytes.

    PubMed

    Dobrzyńska, Małgorzata M; Gajowik, Aneta; Radzikowska, Joanna

    2016-07-01

    The aim of the study was to investigate how coadministration of resveratrol (RSV) at different time after the start of irradiation influences the frequency of micronuclei (MN) in reticulocytes of bone marrow and peripheral blood, and if the RSV supplementation after termination of irradiation may influence the recovery process of damaged cells. Coadministration of RSV with 1-day delay after 1 Gy irradiation significantly decreased the levels of MN in bone marrow and in peripheral blood, whereas with 1-week delay, only in bone marrow reticulocytes. Above combined treatment did not improve the process of recovery. RSV supplementation with 1-day delay relatively to 0.5 Gy irradiation, significantly decreased the frequencies of MN, especially after coadministration with 28mg/kg bw of RSV. Coadministration of RSV since eighth day did not influence the frequencies of MN compared to irradiated cells. The recovery process in the presence of RSV proceeded faster. Supplementation of RSV following initiation of irradiation is beneficial in case of irradiation with lower doses. RSV should be supplemented as soon as possible. Supplementation of RSV after termination of irradiation significantly speed up the recovery. Current results confirmed the ability of RSV to mitigate the effect of irradiation. PMID:26681581

  6. Silibinin attenuates methotrexate-induced pulmonary injury by targeting oxidative stress

    PubMed Central

    KALEMCI, SERDAR; TOPAL, YASAR; CELIK, SERKAN YASAR; YILMAZ, NIGAR; BEYDILLI, HALIL; KOSAR, MEHMET ILKAY; DIRICAN, NIGAR; ALTUNTAS, IRFAN

    2015-01-01

    The aim of the present study was to assess the protective effect of silibinin against methotrexate (MTX)-induced pulmonary toxicity. Rats were divided into four groups (MTX, MTX + silibinin, silibinin and control. MTX was injected intraperitoneally (i.p) into female Wistar rats (10 mg/kg/day for 3 days), which resulted in significant increases in the serum levels of alanine aminotransferase, aspartate aminotransferase and oxidant enzymes, including nitric oxide and myeloperoxidase. Furthermore, significant reductions were detected in the serum activity levels of the antioxidative enzymes, glutathione peroxidase and superoxide dismutase, when compared with the control group. However, administration of silibinin (100 mg/kg/day for 10 days, i.p.) was shown to ameliorate the MTX-induced pulmonary toxicity, as indicated by the normalization of the oxidative stress parameters. Furthermore, silibinin treatment was demonstrated to reduce the histopathological changes associated with MTX. In conclusion, silibinin exhibited protective effects against MTX-induced pulmonary toxicity, which may be attributed to its antioxidant activity. PMID:26622344

  7. Protective Effects of Thymoquinone against Methotrexate-Induced Germ Cell Apoptosis in Male Mice

    PubMed Central

    Sheikhbahaei, Fatemeh; Khazaei, Mozafar; Rabzia, Arezou; Mansouri, Kamran; Ghanbari, Ali

    2016-01-01

    Background Toxic effects of anti-cancer and other drugs on the normal tissues could be reduced by the herbal plants and their fractions. This study investigated the protective effect of thymoquinone (TQ) as a fraction of Nigella sativa on methotrexate (MTX)- induced germ cell apoptosis in male mice. Materials and Methods In this experimental study, thirty male Balb/c mice were divided randomly into 5 groups (n=6). A single dose of MTX (20 mg/kg) and different concentrations of TQ were administrated for 4 consecutive days. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was performed on paraffin embedded tissue sections to analysis the occurrence of apoptosis in the testis. Reverse transcription polymerase chain reaction (RT-PCR) of apoptosis-related genes was performed with RNA extracted from testes of the mice. Statistical analysis was done using one-way ANOVA. Results In the MTX group, there was a significant increase in morphologic sign of germ cell degeneration of tubules (48 ± 0.6%), apoptotic index (AI; 2.3 ± 0.6%), as well as mRNA expression of p53 (P=0.008), caspase 8 (P=0.002), caspase 3 (P=0.005), caspase 9 (P=0.000), bax (P=0.004) and the ratio of bax/bcl-2 (P=0.000), whereas there was an decrease in the expression of bcl-2 (P=0.003), as compared to control group. In MTX+TQ groups, the data showed that different concentrations of TQ could improve the harmful effects caused by the MTX. The best protective effects were achieved in MTX+TQ (10 mg/kg). Conclusion TQ protects testicular germ cell against MTX-induced apoptosis by affecting related genes regulation. PMID:26985343

  8. Studies of methotrexate-induced limb dysplasias utilizing a 51chromium release assay

    SciTech Connect

    Brewton, R.G.; MacCabe, J.A. )

    1990-02-01

    The folate antagonist methotrexate (MTX), widely used in chemotherapy, is a well-documented teratogen. However, the mechanism by which it exerts its effects is still unclear. Specifically, we have examined the cytotoxicity of MTX in vivo and in vitro and have looked at the relationship between cytotoxicity and teratogenesis. The chick embryo was utilized to examine the effects of the drug administered to carefully staged embryos. Embryos were exposed at stages 18-22 and examined on day 11 of incubation. Wings were malformed in a stage-dependent manner while legs were affected similarly at each stage used. A modification of the 51chromium-release assay was used to test the toxicity of MTX to limb cells in vitro. None of the tissues tested showed measurable toxicity in vitro even though the drug kills cells in vivo, thereby suggesting that MTX may be metabolized differently in vitro. Malformations induced by MTX do not seem to be due to changes in the amount of cell death taking place in the limb but may be caused by a transient inhibition of cell division.

  9. Effects of Lycopene Alone or Combined with Melatonin on Methotrexate-Induced Nephrotoxicity in Rats.

    PubMed

    Oguz, Elif; Kocarslan, Sezen; Tabur, Suzan; Sezen, Hatice; Yilmaz, Zehra; Aksoy, Nurten

    2015-01-01

    Methotrexate (Mtx), used for its anticancer and immunsuppresive properties, is known to be a nephrotoxic agent. We aimed to investigate the effects of lycopene (Lyc) alone or combined with melatonin (Mel) on Mtx- induced nephrotoxicity since both of these agents have antioxidant and anti-inflammatory effects. Nephrotoxicity was induced by intraperitoneal administration of methotrexate at a dose of 20 mg/kg. Treatment both with Lyc alone and Lyc combined with Mel provided significant reduction in tumor necrosis factor-alpha, interleukin 1-beta and ceruloplasmin levels in Mtx administered rats. Hovewer, Lyc combined with Mel provided a significant reduction also in NO levels. Hstopathological examination showed that there was an obvious improvement in the degenerative changes compared to Mtx administrated group with the Lyc combined Mel group giving best protection. In conclusion Lyc alone and combined with Mel provided significant improvement against renal damage caused by Mtx, preseumably via antioxidant and anti-inflammatory activities. PMID:26320496

  10. Protective effects of carvacrol against methotrexate-induced testicular toxicity in rats

    PubMed Central

    Daggulli, Mansur; Dede, Onur; Utangac, Mehmet Mazhar; Bodakci, Mehmet Nuri; Hatipoglu, Namık Kemal; Penbegul, Necmettin; Sancaktutar, Ahmet Ali; Bozkurt, Yaşar; Türkçü, Gül; Yüksel, Hatice

    2014-01-01

    To investigate the effect of carvacrol (CAR) on methotrexate (MTX)-induced testis damage in rats. Twenty-four male rats were equally divided into three groups: group I control treatment; group II MTX-treated; group III MTX + CAR-treated. A single dose of CAR was administered intraperitoneally to group III on the first day of the experiment and a single dose of MTX was administered intraperitoneally to groups II and III on the second day of the experiment. The total duration of the experiment was 8 days. Blood samples and testis tissue were obtained from each animal for the measurement of malondialdehyde (MDA), Total oxidant status (TOS), Total Antioxidant Status (TAS), and Oxidative stress index (OSI). Light microscopy was used to complete the histopathological examination of testis specimens from each animal. Analysis of serum and testis sampled revealed that MDA, TOS and OSI levels were significantly greater in the group receiving MTX alone relative to the control treated animals while the TAS level was significantly reduced in the MTX group when compared with the control group. The administration of CAR was associated with significantly decreased MDA, TOS, and OSI levels and increased TAS levels relative to the rats treated with MTX alone. All of these quantitative values demonstrate that CAR alleviates deleterious effects of MTX on testicular tissue. Use of antioxidants such as CAR may protect germ cells against oxidative stress and apoptosis when used in combination with MTX. PMID:25664063

  11. Mechanisms of Thymoquinone Hepatorenal Protection in Methotrexate-Induced Toxicity in Rats

    PubMed Central

    El-Sheikh, Azza A. K.; Morsy, Mohamed A.; Abdalla, Ahlam M.; Hamouda, Azza H.; Alhaider, Ibrahim A.

    2015-01-01

    To investigate mechanisms by which thymoquinone (TQ) can prevent methotrexate- (MTX-) induced hepatorenal toxicity, TQ (10 mg/kg) was administered orally for 10 days. In independent rat groups, MTX hepatorenal toxicity was induced via 20 mg/kg i.p. at the end of day 3 of experiment, with or without TQ. MTX caused deterioration in kidney and liver function, namely, blood urea nitrogen, creatinine, alanine aminotransferase, and aspartate aminotransferase. MTX also caused distortion in renal and hepatic histology, with significant oxidative stress, manifested by decrease in reduced glutathione and catalase, as well as increase in malondialdehyde levels. In addition, MTX caused nitrosative stress manifested by increased nitric oxide, with upregulation of inducible nitric oxide synthase. Furthermore, MTX caused hepatorenal inflammatory effects as shown by increased tumor necrosis factor-α, besides upregulation of necrosis factor-κB and cyclooxygenase-2 expressions. MTX also caused apoptotic effect, as it upregulated caspase 3 in liver and kidney. Using TQ concurrently with MTX restored kidney and liver functions, as well as their normal histology. TQ also reversed oxidative and nitrosative stress, as well as inflammatory and apoptotic signs caused by MTX alone. Thus, TQ may be beneficial adjuvant that confers hepatorenal protection to MTX toxicity via antioxidant, antinitrosative, anti-inflammatory, and antiapoptotic mechanisms. PMID:26089605

  12. Attenuation of Methotrexate-Induced Embryotoxicity and Oxidative Stress by Ethyl Pyruvate

    PubMed Central

    Najafi, Gholamreza; Atashfaraz, Elham; Farokhi, Farah

    2016-01-01

    Background Methotrexate (MTX), as an anti-folate agent, is widely used in the treatment of rheumatic disorders and malignant tumors, however it damages reproductive sys- tem in mice. The aim of this research was to study the effects of ethyl pyruvate (EP) on embryo development and oxidative stress changes in the testis of mice treated with MTX. Materials and Methods In this experimental study, thirty-two adult male Naval Medical Research Institute mice, with average weight of 26 ± 2 g, were divided into four groups. The first group (control) received distilled water (0.1 ml/mice/day), while the second group was intraperitoneally (IP) treated with 20 mg/kg MTX once per week. The third group was IP treated with 40 mg/kg/day EP, and the fourth group was IP treated with both 20 mg/kg MTX and 40 mg/kg/day EP for 30 days. At the end of treatment fertilization rate and embryonic development were evaluated. Differences between these groups were assessed by ANOVA using the SPSS software package for Windows with a Tukey-Kramer multiple post-hoc comparison test. Results MTX treatment caused significant (P<0.05) increase in malondialdehyde (MDA) and reduced catalase (CAT), as well as leading to in vitro fertilization (IVF) and embryonic development. The improved effects of EP on the IVF were determined by the reduced level of MDA (index of oxidative stress) and significant increased level of CAT (a key antioxidant). We observed significant increase in fertilization rate and embryonic development in the treated group with both MTX and EP. Conclusion It is suggested that EP can be useful in ameliorating testicular damages and embryotoxicity induced by MTX. These effects could be attributed to its antioxidant properties. PMID:27441057

  13. Carvacrol and Pomegranate Extract in Treating Methotrexate-Induced Lung Oxidative Injury in Rats

    PubMed Central

    Şen, Hadice Selimoğlu; Şen, Velat; Bozkurt, Mehtap; Türkçü, Gül; Güzel, Abdulmenap; Sezgi, Cengizhan; Abakay, Özlem; Kaplan, Ibrahim

    2014-01-01

    Background This study was designed to evaluate the effects of carvacrol (CRV) and pomegranate extract (PE) on methotrexate (MTX)-induced lung injury in rats. Material/Methods A total of 32 male rats were subdivided into 4 groups: control (group I), MTX treated (group II), MTX+CRV treated (group III), and MTX+PE treated (group IV). A single dose of 73 mg/kg CRV was administered intraperitoneally to rats in group III on Day 1 of the investigation. To group IV, a dose of 225 mg/kg of PE was administered via orogastric gavage once daily over 7 days. A single dose of 20 mg/kg of MTX was given intraperitoneally to groups II, III, and IV on Day 2. The total duration of experiment was 8 days. Malondialdehyde (MDA), total oxidant status (TOS), total antioxidant capacity (TAC), and oxidative stress index (OSI) were measured from rat lung tissues and cardiac blood samples. Results Serum and lung specimen analyses demonstrated that MDA, TOS, and OSI levels were significantly greater in group II relative to controls. Conversely, the TAC level was significantly reduced in group II when compared to the control group. Pre-administering either CRV or PE was associated with decreased MDA, TOS, and OSI levels and increased TAC levels compared to rats treated with MTX alone. Histopathological examination revealed that lung injury was less severe in group III and IV relative to group II. Conclusions MTX treatment results in rat lung oxidative damage that is partially counteracted by pretreatment with either CRV or PE. PMID:25326861

  14. Protective effects of carvacrol and pomegranate against methotrexate-induced intestinal damage in rats

    PubMed Central

    Türkcü, Gül; Alabalık, Ulaş; Keleş, Ayşe Nur; Bozkurt, Mehtap; İbiloğlu, İbrahim; Fırat, Uğur; Büyükbayram, Hüseyin

    2015-01-01

    Objective: The purpose of this experimental study was to evaluate the efficacy of carvacrol (CVR) and pomegranate (PMG) against methotrexate (MTX)-induced intestinal damage using histopathological and immunohistochemical techniques. Methods: Thirty-two male Sprague-Dawley rats, weighing 195-250 g, were divided into four groups: control, MTX treatment alone, MTX plus CVR and MTX plus PMG. A single dose of CVR (73 mg/kg) was administered intraperitoneally to group III on the first day of the experiment, PMG (225 mg/kg/day) was administered orogastrically (with a gavage needle) once daily for 7 days and a single dose of MTX (20 mg/kg) was administered intraperitoneally on the second day of the experiment. Intestinal tissues were obtained on 8th day, and examined for villus damage, crypt damage, and inflammation. Ki-67 and Caspase 3 staining was used for immunohistochemical evaluation. Results: MTX treatment induced villus shortening and fusion, epithelial atrophy, crypt loss, inflammatory infiltrate in the lamina propria, and goblet cell depletion. The CVR and PMG decreased the severity of intestinal damage caused by MTX treatment. In the MTX-received group, significant inflammatory cell infiltration was observed in the lamina propria. Compared to the MTX-received group, the PMG and CVR groups showed less villus and crypt damage and less inflammation in the lamina propria. Fewer Ki-67 positive cells were observed in the crypts of the MTX-received groups compared to the control group. There were more Ki-67 positive cells in the CVR and PMG groups compared to MTX group. The MTX-received group exhibited more caspase-3 positive cells than the control group, and the number of caspase-3 positive cells were decreased in the CVR and PMG treated groups. Conclusion: This study is the first to show that PMG and CVR decrease MTX-related damage and apoptotic activity in intestinal tissue. PMID:26629037

  15. Altered systemic bioavailability and organ distribution of azathioprine in methotrexate-induced intestinal mucositis in rats

    PubMed Central

    Karbelkar, Sadaf A.; Majumdar, Anuradha S.

    2016-01-01

    Objective: Intestinal mucositis is a significant problem haunting clinicians for decades. One of the major reasons for its occurrence is high-dose chemotherapy. The study is aimed at investigating effect of intestinal mucositis on pharmacokinetics, organ distribution, and bioavailability of azathioprine (AZA) (6-mercaptopurine). Materials and Methods: Intestinal mucositis was induced with methotrexate (MTX) (2.5 mg/kg). The oral absorption of AZA and 6-mercaptopurine (metabolite) levels were determined in control and MTX-treated rats: ex vivo (noneverted sac technique) and in vivo (pharmacokinetics and organ-distribution) using high-performance liquid chromatography. Immunohistochemistry was conducted to evaluate peptide transporter expression on luminal membrane of small intestine. Results: Intestinal permeation of AZA into systemic circulation of rats was lower after MTX administration, widely found in intestinal segments of mucositis-induced rats leading to decline in systemic bioavailability of AZA. Immunohistochemistry findings indicated diminution of peptide transporter expression representing hampered absorption of drugs absorbed via this transporter. Conclusion: Study outcome has thrown light on altered fate of AZA when administered to individuals with mucositis which suggests modified drug therapy. These findings can further be investigated in different drug classes which might be administered concomitantly in mucositis and study outcome can be further confirmed in mucositis patients in clinical practice also. PMID:27298491

  16. Inhibition of methotrexate-induced chromosomal damage by vanillin and chlorophyllin in V79 cells.

    PubMed

    Keshava, C; Keshava, N; Whong, W Z; Nath, J; Ong, T M

    Methotrexate (MTX), a chemotherapeutic agent used to treat cancer, produces cytogenetic damage and has a cytostatic effect in a variety of test systems. Several antigenotoxic agents have been studied in various in vitro and in vivo systems. However, data are limited regarding their ability to modulate MTX-induced genotoxicity. In the present study, vanillin (VA) and chlorophyllin (CHL) were used as antigenotoxic agents to study their ability to minimize the DNA damage caused by MTX. Exponentially growing V79 Chinese hamster lung cells were treated with MTX at five different concentrations (5-100 micrograms/ml) with S9 activation for 6 h and post-treated with two concentrations of either VA (50 or 100 micrograms/ml) or CHL (50 or 100 micrograms/ml) for 40 h. Cytochalasin B was added for the micronucleus (MN) assay along with antigenotoxic agents to evaluate MN in binucleated cells. Chromosomal aberrations were also evaluated in parallel cultures. Results indicate that MTX alone induced a dose-dependent decrease in the nuclear division index (NDI) and the mitotic index (MI). A significant increase in percent micronucleated binucleated cells (MNBN) and percent aberrant cells (Abs) was observed. Studies using VA as an antigenotoxic agent showed a decrease in the number of MNBN (26.3-83.1%) and Abs (16.0-87.5%) with the addition of either 50 or 100 micrograms VA/ml. The addition of CHL also significantly reduced the number of MNBN (53.0-91.5%) at both concentrations tested. Chromosomal aberrations were also significantly reduced (41.0-83.0). These studies indicate that both VA and CHL are capable of effectively minimizing MTX-induced chromosomal damage. PMID:9485540

  17. Potential protective effect of etanercept and aminoguanidine in methotrexate-induced hepatotoxicity and nephrotoxicity in rats.

    PubMed

    Hafez, Heba M; Ibrahim, Mohamed A; Ibrahim, Salwa A; Amin, Entesar F; Goma, Wafaey; Abdelrahman, Aly M

    2015-12-01

    Methotrexate (MTX), a chemotherapeutic and immunosuppressant drug, is generally well-tolerated by most patients. However, its cytotoxic nature contributes to life-threatening side effects including hepatotoxicity and nephrotoxicity. The present study investigated the possible role of tumor necrosis factor-alpha (TNF-α) inhibitor, etanercept and inducible nitric oxide synthase (iNOS) inhibitor, aminoguanidine, on MTX-induced hepatotoxicity and nephrotoxicity in rats. Rats were divided into 7 groups: control group, etanercept group, aminoguanidine group, MTX group, MTX+etanercept group, MTX+aminoguanidine group, and MTX+etanercept+aminoguanidine group. MTX caused hepatotoxicity and nephrotoxicity as evidenced biochemically by significant increase in serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea and creatinine, respectively as well as by histopathological changes. Such effects were associated with significant changes in oxidative stress markers (malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase (SOD), catalase, and glutathione (GSH)) as well as by upregulation of TNF-α, iNOS and caspase-3 expressions in hepatic and renal tissues. Etanercept and aminoguanidine significantly attenuated MTX-hepatotoxicity and nephrotoxicity. The protective effect of either agent was associated with significant improvement in oxidative stress parameters as well as by downregulation of TNF-α, iNOS and caspase-3 expressions in hepatic and renal tissues. The study suggested that inhibitors of either TNF-α and/or iNOS have protective effect in MTX-induced hepatotoxicity and nephrotoxicity. The protective effect of either agent relies, at least partially, on their antioxidant effects and decreased TNF-α, iNOS, and caspase-3 expressions. PMID:26332135

  18. Lactose maldigestion during methotrexate-induced gastrointestinal mucositis in a rat model.

    PubMed

    Fijlstra, M; Rings, E H H M; Verkade, H J; van Dijk, T H; Kamps, W A; Tissing, W J E

    2011-02-01

    Patients with chemotherapy-induced gastrointestinal mucositis suffer from anorexia, diarrhea, and stomach pain, often causing weight loss and malnutrition. When the intestinal function during mucositis would be known, a rational feeding strategy might improve the nutritional state, accelerate recuperation, and increase survival of mucositis patients. We developed a methotrexate (MTX)-induced mucositis rat model to study nutrient digestion and absorption. To determine lactose digestion and absorption of its derivative glucose during mucositis, we injected Wistar rats intravenously with MTX (60 mg/kg) or 0.9% NaCl (controls). Four days later, we orally administered trace amounts of [1-(13)C]lactose and [U-(13)C]glucose and quantified the appearance of labeled glucose in the blood for 3 h. Finally, we determined plasma citrulline level and harvested the small intestine to assess histology, myeloperoxidase level, glycohydrolase activity, immunohistochemical protein, and mRNA expression. MTX-treated rats showed profound villus atrophy and epithelial damage. During the experimental period, the absorption of lactose-derived [1-(13)C]glucose was 4.2-fold decreased in MTX-treated rats compared with controls (P < 0.01). Lactose-derived [1-(13)C]glucose absorption correlated strongly with villus length (rho = 0.86, P < 0.001) and with plasma citrulline level (rho = 0.81, P < 0.001). MTX treatment decreased jejunal lactase activity (19.5-fold, P < 0.01) and immunohistochemical protein and mRNA expression (39.7-fold, P < 0.01) compared with controls. Interestingly, MTX treatment did not affect the absorption of [U-(13)C]glucose during the experimental period. We conclude that lactose digestion is severely decreased during mucositis while glucose absorption is still intact, when supplied in trace amounts. Plasma citrulline level might be a useful objective, noninvasive marker for lactose maldigestion during mucositis in clinic. PMID:21088238

  19. Protective effect of calcium folinate against methotrexate-induced endosalpinx damage in rats.

    PubMed

    Yang, Xiao-Jun; Chen, Yan-Ping; Wang, Han-Chu; Zhao, Jing; Zheng, Fei-Yun

    2011-03-15

    The aim of this study was to evaluate the protective effect of calcium folinate (CF) applied in 10% of the methotrexate (MTX) dosage against morphologic and steroid-receptor damage induced by MTX in rat endosalpinx. The result indicated that endosalpingitis, the ultrastructural damage of endosalpinx, and a change in estrogen and P receptor expression induced by low- and high-dose MTX in endosalpinx can be reversed completely and partly (B1, B2) by combined treatment with CF, suggesting that CF combined with MTX protects against the side effects induced by MTX. PMID:20869049

  20. Methotrexate-induced myelopathy responsive to substitution of multiple folate metabolites.

    PubMed

    Ackermann, R; Semmler, A; Maurer, G D; Hattingen, E; Fornoff, F; Steinbach, J P; Linnebank, M

    2010-05-01

    Methotrexate (MTX)-associated myelopathy is a rare but serious subacute complication of MTX-based chemotherapy. We report the case of a woman with breast cancer and meningeal carcinomatosis who developed severe progressive myelopathy after four cycles of intrathecal MTX administration. We substituted high doses of the key metabolites of the methyl-transfer pathway: S-adenosylmethionine (SAM), 200 mg three times daily i.v.; folinate, 20 mg four times daily i.v.; cyanocobalamin, 100 microg once daily i.v.; and methionine, 5 g daily p.o. The patient's paraparesis improved rapidly thereafter, and magnetic resonance (MR) imaging showed resolution of the intramedullary lesions. Genetic analyses revealed homozygosity for the A allele of methylenetetrahydrofolate reductase (MTHFR) c.1298A>C (p.E429A), whereas other genetic variants of folate/methionine metabolism associated with MTX neurotoxicity were not present. Substitution with multiple folate metabolites may be a promising strategy for the treatment of MTX-induced neurotoxicity. PMID:19821069

  1. Micronuclei in Cord Blood Lymphocytes and Associations with Biomarkers of Exposure to Carcinogens and Hormonally Active Factors, Gene Polymorphisms, and Gene Expression: The NewGeneris Cohort

    PubMed Central

    Merlo, Domenico Franco; Agramunt, Silvia; Anna, Lívia; Besselink, Harrie; Botsivali, Maria; Brady, Nigel J.; Ceppi, Marcello; Chatzi, Leda; Chen, Bowang; Decordier, Ilse; Farmer, Peter B.; Fleming, Sarah; Fontana, Vincenzo; Försti, Asta; Fthenou, Eleni; Gallo, Fabio; Georgiadis, Panagiotis; Gmuender, Hans; Godschalk, Roger W.; Granum, Berit; Hardie, Laura J.; Hemminki, Kari; Hochstenbach, Kevin; Knudsen, Lisbeth E.; Kogevinas, Manolis; Kovács, Katalin; Kyrtopoulos, Soterios A.; Løvik, Martinus; Nielsen, Jeanette K; Nygaard, Unni Cecilie; Pedersen, Marie; Rydberg, Per; Schoket, Bernadette; Segerbäck, Dan; Singh, Rajinder; Sunyer, Jordi; Törnqvist, Margareta; van Loveren, Henk; van Schooten, Frederik J.; Vande Loock, Kim; von Stedingk, Hans; Wright, John; Kirsch-Volders, Micheline; van Delft, Joost H.M.

    2013-01-01

    Background: Leukemia incidence has increased in recent decades among European children, suggesting that early-life environmental exposures play an important role in disease development. Objectives: We investigated the hypothesis that childhood susceptibility may increase as a result of in utero exposure to carcinogens and hormonally acting factors. Using cord blood samples from the NewGeneris cohort, we examined associations between a range of biomarkers of carcinogen exposure and hormonally acting factors with micronuclei (MN) frequency as a proxy measure of cancer risk. Associations with gene expression and genotype were also explored. Methods: DNA and protein adducts, gene expression profiles, circulating hormonally acting factors, and GWAS (genome-wide association study) data were investigated in relation to genomic damage measured by MN frequency in lymphocytes from 623 newborns enrolled between 2006 and 2010 across Europe. Results: Malondialdehyde DNA adducts (M1dG) were associated with increased MN frequency in binucleated lymphocytes (MNBN), and exposure to androgenic, estrogenic, and dioxin-like compounds was associated with MN frequency in mononucleated lymphocytes (MNMONO), although no monotonic exposure–outcome relationship was observed. Lower frequencies of MNBN were associated with a 1-unit increase expression of PDCD11, LATS2, TRIM13, CD28, SMC1A, IL7R, and NIPBL genes. Gene expression was significantly higher in association with the highest versus lowest category of bulky and M1dG–DNA adducts for five and six genes, respectively. Gene expression levels were significantly lower for 11 genes in association with the highest versus lowest category of plasma AR CALUX® (chemically activated luciferase expression for androgens) (8 genes), ERα CALUX® (for estrogens) (2 genes), and DR CALUX® (for dioxins). Several SNPs (single-nucleotide polymorphisms) on chromosome 11 near FOLH1 significantly modified associations between androgen activity and MNBN

  2. Protective effects of antioxidants on micronuclei induced by camphorquinone/N,N-dimethyl-p-toluidine employing in vitro mammalian test system.

    PubMed

    Li, Yi-Ching; Huang, Fu-Mei; Lee, Shiaun-Shinn; Lin, Ruey-Hseng; Chang, Yu-Chao

    2007-07-01

    Camphorquinone (CQ) is widely used as an initiator in modern visible-light (VL) cured resin systems. CQ is also characterized as a potential allergenic compound. To date, there is growing concern that CQ may produce genetic damage by inducing mutation. In this study, CQ in the presence of reducing agent N,N-dimethyl-p-toluidine (DMT) with or without VL irradiation was analyzed for the induction of chromosomal aberrations indicated by micronuclei (MN) induced in CHO cells. Our data demonstrated that an increase in the numbers of MN was observed with CQ/DMT with or without VL irradiation (p < 0.05). Significant prolongation of cell cycles was observed by the treatment with CQ/DMT with or without VL irradiation (p < 0.05). In addition, VL irradiated CQ/DMT was found to exhibit significantly genotoxic and cytotoxic effects as compared with CQ/DMT alone (p < 0.05). Furthermore, to determine whether oxidative stress could modulate the MN induced by CQ/DMT with or without VL irradiation in CHO cells, cells were pre-treated with various antioxidants 10 mM N-acetyl-L-cysteine (NAC), 2 mM ascorbic acid, and 2 mM alpha-tocopherol. The pre-treatment with antioxidants could antagonize not only the increased MN cells but also the prolonged cell cycle induced by CQ/DMT with or without VL irradiation in CHO cells (p < 0.05). Our findings provide the evidences for the induction of MN by CQ/DMT employing mammalian test system, indicating clastogenic activity of CQ/DMT with or without VL irradiation in vitro. In addition, VL irradiated CQ/DMT exhibits higher genotoxic and cytotoxic effects than CQ/DMT alone. Moreover, NAC, ascorbic acid, and alpha-tocopherol act as the antagonists against the genotoxicity and cytotoxicity of CQ/DMT with or without VL irradiation. PMID:17041928

  3. Analysis of chromosomal aberrations, sister-chromatid exchanges and micronuclei in peripheral lymphocytes of pharmacists before and after working with cytostatic drugs.

    PubMed

    Roth, S; Norppa, H; Järventaus, H; Kyyrönen, P; Ahonen, M; Lehtomäki, J; Sainio, H; Sorsa, M

    1994-12-01

    The frequencies of chromosome aberrations, SCEs and micronuclei (cytokinesis-block method) in blood lymphocytes were compared among six nonsmoking female pharmacists before and after 1 year of working with cytostatic drugs. All possible precautions were taken to avoid exposure to cytostatics, including proper protective clothing and a monitored, negative-pressured working environment with vertical laminar flow cabinet. As referents, an age-matched group of six nonsmoking female hospital workers not dealing with cytostatics was simultaneously sampled twice with the same time interval. The pharmacists showed a marginally higher mean frequency of SCEs/cell (6.3; P = 0.049) after the working period than 1 year earlier (5.8). On the other hand, the referents, with no obvious exposure, had a higher mean number of cells with chromatid-type aberrations, gaps excluded, in the second sampling (2.0%; P = 0.048) than in the first one (0.5%). In addition, a slight (P = 0.055) trend towards a higher frequency of micronucleated binucleate cells was observed in the second sampling for both the exposed and control subjects. As such findings suggest technical variation in the cytogenetic parameters, the small difference observed in SCEs for the pharmacists between the two samplings was probably not related to the cytostatics exposure. No statistically significant differences were observed for any of the cytogenetic parameters in comparisons between the pharmacists and the referents. The findings suggest that caution should be exercised in comparing results obtained from two different samplings in prospective cytogenetic studies. PMID:7527908

  4. Human CYP2E1-dependent and human sulfotransferase 1A1-modulated induction of micronuclei by benzene and its hydroxylated metabolites in Chinese hamster V79-derived cells.

    PubMed

    Jiang, Hao; Lai, Yanmei; Hu, Keqi; Wei, Qinzhi; Liu, Yungang

    2014-12-01

    Benzene is a ubiquitous environmental pollutant and a confirmed human carcinogen, which requires metabolic activation, primarily by CYP2E1, for most of its biological actions. Chromosome damages in benzene-exposed workers and rodents have been observed, and in their urine sulfo- and glucuronide-conjugates of phenol and hydroquinone were present. Yet, direct evidence for human CYP2E1-activated mutagenicity of benzene and the exact significance of phase II metabolism for inactivating benzene metabolites are still missing. In the present study, benzene and its oxidized metabolites (phenol, hydroquinone, catechol, 1,2,4-trihydroxybenzene and 1,4-benzoquinone) were investigated for induction of micronuclei in a V79-derived cell line genetically engineered for expression of both human CYP2E1 and human sulfotransferase (SULT) 1A1 (indicated by active micronuclei induction by 1-hydroxymethylpyrene). The results demonstrated concentration-dependent induction of micronuclei by benzene and phenol, though with lower potency or efficacy than the other metabolites. Inhibition of CYP2E1 by 1-aminobenzotriazole did not change the effect of benzoquinone, but completely abolished that of benzene and phenol, and attenuated that of the other compounds. Moreover, inhibition of SULT1A1 by pentachlorophenol potentiated the effects of benzene, hydroquinone, catechol and trihydroxybenzene. Ascorbic acid, a reducing and free radical-scavenging agent, significantly lowered the effects of hydroquinone, catechol, trihydroxybenzene as well as N-nitrosodimethylamine (a known CYP2E1-dependent promutagen), with that of benzoquinone unaffected. These results suggest that in addition to activating benzene and phenol, human CYP2E1 may further convert hydroquinone, catechol and trihydroxybenzene to more genotoxic metabolites, and sulfo-conjugation of the multi-hydroxylated metabolites of benzene by human SULT1A1 may represent an important detoxifying pathway. PMID:25771868

  5. Cell cycle synchronization and BrdU incorporation as a tool to study the possible selective elimination of ErbB1 gene in the micronuclei in A549 cells.

    PubMed

    Lauand, C; Niero, E L; Dias, V M; Machado-Santelli, G M

    2015-05-01

    Lung cancer often exhibits molecular changes, such as the overexpression of the ErbB1 gene that encodes epidermal growth factor receptor (EGFR). ErbB1 amplification and mutation are associated with tumor aggressiveness and low response to therapy. The aim of the present study was to design a schedule to synchronize the cell cycle of A549 cell line (a non-small cell lung cancer) and to analyze the possible association between the micronuclei (MNs) and the extrusion of ErbB1 gene extra-copies. After double blocking, by the process of fetal bovine serum deprivation and vincristine treatment, MNs formation was monitored with 5-bromo-2-deoxyuridine (BrdU) incorporation, which is an S-phase marker. Statistical analyses allowed us to infer that MNs may arise both in mitosis as well as in interphase. The MNs were able to replicate their DNA and this process seemed to be non-synchronous with the main cell nuclei. The presence of ErbB1 gene in the MNs was evaluated by fluorescent in situ hybridization (FISH). ErbB1 sequences were detected in the MNs, but a relation between the MNs formation and extrusion of amplified ErbB1 could not be established. The present study sought to elucidate the meaning of MNs formation and its association with the elimination of oncogenes or other amplified sequences from the tumor cells. PMID:25760027

  6. Cell cycle synchronization and BrdU incorporation as a tool to study the possible selective elimination of ErbB1 gene in the micronuclei in A549 cells

    PubMed Central

    Lauand, C.; Niero, E.L.; Dias, V.M.; Machado-Santelli, G.M.

    2015-01-01

    Lung cancer often exhibits molecular changes, such as the overexpression of the ErbB1 gene that encodes epidermal growth factor receptor (EGFR). ErbB1 amplification and mutation are associated with tumor aggressiveness and low response to therapy. The aim of the present study was to design a schedule to synchronize the cell cycle of A549 cell line (a non-small cell lung cancer) and to analyze the possible association between the micronuclei (MNs) and the extrusion of ErbB1 gene extra-copies. After double blocking, by the process of fetal bovine serum deprivation and vincristine treatment, MNs formation was monitored with 5-bromo-2-deoxyuridine (BrdU) incorporation, which is an S-phase marker. Statistical analyses allowed us to infer that MNs may arise both in mitosis as well as in interphase. The MNs were able to replicate their DNA and this process seemed to be non-synchronous with the main cell nuclei. The presence of ErbB1 gene in the MNs was evaluated by fluorescent in situ hybridization (FISH). ErbB1 sequences were detected in the MNs, but a relation between the MNs formation and extrusion of amplified ErbB1could not be established. The present study sought to elucidate the meaning of MNs formation and its association with the elimination of oncogenes or other amplified sequences from the tumor cells. PMID:25760027

  7. Methotrexate-induced mucositis in acute leukemia patients is not associated with the MTHFR 677T allele in Mexico.

    PubMed

    Ruiz-Argüelles, Guillermo J; Coconi-Linares, Lucia Nancy; Garcés-Eisele, Javier; Reyes-Núñez, Virginia

    2007-10-01

    Methylenetetrahydrofolate reductase (MTHFR) has two common variants with reduced activity due to polymorphisms at nucleotides 677 and 1298. Both affect folate metabolism and thus remethylation of homocysteine, but are also thought to affect nucleotide synthesis and DNA methylation. Methotrexate (MTX), which interrupts folate metabolism, is used in the treatment of a variety of diseases including acute lymphoblastic leukemia (ALL), but exerts in some patients toxic effects on fast dividing tissues such as mucosal epithelia. The enhanced toxicity may be due to cooperative effects between MTX and MTHFR variants. Accordingly, it has been reported that carrying the 677T allele of the MTHFR is a risk factor for MTX-associated mucositis. As in the Mexican population, which is characterized by a high prevalence of the 677T MTHFR variant, several of its commonly associated defects have not been observed, we investigated the relationship between MTX toxicity and the 677T allele. Out of 28 patients with ALL (CC: 2, CT: 10, TT: 16), 16 had episodes of MTX-associated mucositis (CC: 0, CT: 6, TT: 10). Neither at the gene level nor at the genotype level was a significant association with mucositis found. It may be postulated that the risk of higher MTX toxicity in patients with decreased MTHFR activity could be neutralized by the normally folate rich diet in Mexico. PMID:17891601

  8. Effect of captopril and telmisartan on methotrexate-induced hepatotoxicity in rats: impact of oxidative stress, inflammation and apoptosis.

    PubMed

    Kelleni, Mina T; Ibrahim, Salwa A; Abdelrahman, Aly M

    2016-06-01

    Methotrexate (MTX) is a commonly used antineoplastic and anti-rheumatoid drug whose efficacy is limited by its hepatotoxicity. The aim of this study was to investigate the possible protective role of captopril (100 mg/kg/day, p.o. for seven days), an angiotensin converting enzyme inhibitor, and telmisartan (10 mg/kg/day p.o. for seven days), an angiotensin II receptor blocker with peroxisome proliferative receptor gamma (PPARγ) agonism, in a model of MTX (single dose 20 mg/kg i.p. at the fifth day) induced hepatotoxicity in rats. Results of the present study revealed MTX-induced hepatotoxicity as demonstrated by increased level of liver enzymes and confirmed by histopathology. Pretreatment with captopril or telmisartan produced a significant hepatic protection manifested as a significant (p < 0.05) decrease in serum levels of alanine transferase (ALT) and aspartate transferase (AST) and alkaline phosphatase (ALP) enzymes; hepatic malondialdehyde (MDA) and total nitrites and nitrates (NOx) levels; as well as a significant increase in hepatic superoxide dismutase (SOD) activity. In addition, there was a remarkable improvement in the histopathological features and a significant reduction in the expression of COX-2, iNOS and caspase-3 enzymes as compared with the MTX group. We recommend considering captopril/Telmisartan, if tolerated and not contraindicated, as preferable antihypertensive agents in patients receiving MTX in their chemotherapy protocols. PMID:27269004

  9. All-trans retinoic acid mitigates methotrexate-induced liver injury in rats; relevance of retinoic acid signaling pathway.

    PubMed

    Ewees, Mohamed G; Abdelghany, Tamer M; Abdel-Aziz, Abdel-Aziz H; Abdel-Bakky, Mohamed S

    2015-09-01

    Methotrexate (MTX) is a widely used drug for treatment of rheumatic and autoimmune diseases as well as different types of cancer. One of the major side effects of MTX is hepatotoxicity. Retinoid receptors, including retinoid X receptor (RXR), and retinoic acid receptor (RAR) are vitamin A receptors that are highly expressed in the liver and regulate important physiological processes through regulation of different genes. In this study, we investigated the effect of MTX on RXR-α and RAR-α expression in the liver and the potential protective effects of all-trans retinoic acid (ATRA) in MTX-induced hepatotoxicity. Rats were randomly divided into five groups: The rates were treated with saline, DMSO, MTX (20 mg/kg/IP; single dose), ATRA (7.5 mg/kg/day, I.P), or MTX and ATRA. Rats were killed 24 h after the last ATRA injection. The liver tissues were dissected out, weighed, and subjected to histological, immunohistochemical, and biochemical examinations. Our results demonstrated that treatment with MTX resulted in significant decrease in reduced glutathione (GSH) content and superoxide dismutase (SOD) activity, with concomitant increase in ALT, AST, and MDA levels. In addition, MTX markedly downregulated the expression of both RXR-α and RAR-α, and changed the appearance of RXR-α to be very small speckled droplets. Treatment with ATRA significantly ameliorated MTX-induced effects on GSH, ALT, and MDA. Moreover, ATRA administration increased the expression and nuclear translocation of RXR-α in rat hepatocytes. In conclusion, our study revealed, for the first time, that retinoid receptors may play an important role in the MTX-induced hepatotoxicity. PMID:25971792

  10. Protective effect of ellagic acid and pumpkin seed oil against methotrexate-induced small intestine damage in rats.

    PubMed

    El-Boghdady, Noha A

    2011-12-01

    Gastrointestinal toxicity is one of the most serious side effects in the methotrexate (MTX) treatment. This study was designed to investigate whether ellagic acid (EA) and/or pumpkin seed oil (PSO) had a protective effect on MTX-induced small intestine damage. Forty albino rats were randomized into five groups of 8 rats each. Group I served as a normal control group. In Group II, MTX was administered as a single dose (20 mg/kg) intraperitoneally. Groups III, IV and V were pre-treated respectively with either PSO (40 mg/kg), EA (10 mg/kg) or 0.2% DMSO (vehicle control) orally every day by gavage for 5 days and then they received MTX. All animals were sacrificed 5 days after the intraperitoneal injection of MTX for histopathological examination, estimation of serum prostaglandin E2 (PGE2) level, assay of tissue malondialdehyde (MDA), reduced glutathione (GSH) and nitric oxide (NO) levels and myloperoxidase (MPO), xanthine oxidase (XO) and adenosine deaminase (AD) activities. Administration of EA and/or PSO decreased the intestinal damage, PGE2, MDA and NO levels and MPO, XO and AD activities and increased GSH level. These results suggest that EA and PSO protect the small intestine of rats from MTX-induced damage through their antioxidant and anti-inflammatory effects and thus have potential as a promising drug in the prevention of undesired side effects of MTX. PMID:22329239

  11. Protective effects of vitamin E and Cornus mas fruit extract on methotrexate-induced cytotoxicity in sperms of adult mice

    PubMed Central

    Zarei, Leila; Sadrkhanlou, Rajabali; Shahrooz, Rasoul; Malekinejad, Hassan; Eilkhanizadeh, Behroz; Ahmadi, Abbas

    2014-01-01

    This study was aimed to assess the protective effects of Cornus mas fruit extract (CMFE) and vitamin E (Vit E) on sperm quality parameters in the methotrexate (MTX)-treated mice. Forty-eight young adult male mice (8-12 weeks) were randomly divided into six groups including control and test groups. The control group received normal saline orally , and the test groups were treated MTX (20 mg kg-1, ip, once weekly), MTX + CMFE (250 mg kg-1), MTX + CMFE (500 mg kg-1), MTX + CMFE (1000 mg kg-1), and MTX + Vit E (100 IU kg-1, po) for 35 consecutive days. On day 35, after euthanasia the epididymal sperms were isolated. Then the total mean sperm count, sperm viability and motility were determined. The total antioxidant capacity (TAOC) of all experimental groups were also evaluated. The MTX-treated animals showed a significant changes in all parameters of sperm quality assessment compared to the control group. Both Vit E and CMFE were able to protect from MTX-induced effects on sperm maturity and DNA damage. Co-administration of MTX and CMFE and/or Vit E resulted in protection from MTX-reduced TAOC. In conclusion, these data suggested that MTX administration could adversely affect the sperm quality. Moreover, the protective effect of Vit E and CMFE on MTX-induced sperm toxicity was also documented. PMID:25568688

  12. Protective effect of resveratrol against methotrexate-induced oxidative stress in the small intestinal tissues of rats.

    PubMed

    Arslan, Aynur; Ozcicek, Fatih; Keskin Cimen, Ferda; Altuner, Durdu; Yarali, Oguzhan; Kurt, Nezahat; Tumkaya, Levent; Ozturk, Cengiz; Suleyman, Halis

    2015-01-01

    The effect of resveratrol on the damage induced by methotrexate (MTX) in rat duodenum and jejunum tissue was investigated and evaluated in comparison with famotidine. The rats were divided into four groups as healthy group (HG), resveratrol+MTX (RMTX) group, famotidine+MTX (FMTX) group and the control group which received MTX (MTXC). RMTX group was given resveratrol 25 mg/kg and FMTX group famotidin 25 mg/kg, while MTXC and HG groups were orally administered distilled water once a day for 30 days. The rats in RMTX, FMTX and MTXC groups were given MTX of 5 mg/kg dose by the same way for 30 days. At the end of this period, amount of MDA, 8-OH/Gua and tGSH, and MPO gene expression were measured in the duodenal and jejunal tissues and the results were histopathologically evaluated. Resveratrol and famotidine were found to significantly prevent elevation of the MDA, 8-OH/Gua and MPO parameters with MTX and decrease of the levels of tGSH in the duodenal and jejunal tissues. Both drugs prevented severe damage to the villus and crypt epithelium in the duodenum and jejunum, congestion and hemorrhage, inflammatory cell infiltration and necrosis in the mucosa and submucosa due to MTX administration. Resveratrol could be considered in the clinical practice for treatment of the tissue damage in the intestines due to use of MTX, in comparison with famotidine. Resveratrol may be more advantageous than famotidine in long-term use against MTX toxicity since it does not inhibit gastric acid secretion. PMID:26379839

  13. Protective effect of resveratrol against methotrexate-induced oxidative stress in the small intestinal tissues of rats

    PubMed Central

    Arslan, Aynur; Ozcicek, Fatih; Keskin Cimen, Ferda; Altuner, Durdu; Yarali, Oguzhan; Kurt, Nezahat; Tumkaya, Levent; Ozturk, Cengiz; Suleyman, Halis

    2015-01-01

    The effect of resveratrol on the damage induced by methotrexate (MTX) in rat duodenum and jejunum tissue was investigated and evaluated in comparison with famotidine. The rats were divided into four groups as healthy group (HG), resveratrol+MTX (RMTX) group, famotidine+MTX (FMTX) group and the control group which received MTX (MTXC). RMTX group was given resveratrol 25 mg/kg and FMTX group famotidin 25 mg/kg, while MTXC and HG groups were orally administered distilled water once a day for 30 days. The rats in RMTX, FMTX and MTXC groups were given MTX of 5 mg/kg dose by the same way for 30 days. At the end of this period, amount of MDA, 8-OH/Gua and tGSH, and MPO gene expression were measured in the duodenal and jejunal tissues and the results were histopathologically evaluated. Resveratrol and famotidine were found to significantly prevent elevation of the MDA, 8-OH/Gua and MPO parameters with MTX and decrease of the levels of tGSH in the duodenal and jejunal tissues. Both drugs prevented severe damage to the villus and crypt epithelium in the duodenum and jejunum, congestion and hemorrhage, inflammatory cell infiltration and necrosis in the mucosa and submucosa due to MTX administration. Resveratrol could be considered in the clinical practice for treatment of the tissue damage in the intestines due to use of MTX, in comparison with famotidine. Resveratrol may be more advantageous than famotidine in long-term use against MTX toxicity since it does not inhibit gastric acid secretion. PMID:26379839

  14. Cytoprotective effects of amifostine, ascorbic acid and N-acetylcysteine against methotrexate-induced hepatotoxicity in rats

    PubMed Central

    Akbulut, Sami; Elbe, Hulya; Eris, Cengiz; Dogan, Zumrut; Toprak, Gulten; Otan, Emrah; Erdemli, Erman; Turkoz, Yusuf

    2014-01-01

    AIM: To investigate the potential role of oxidative stress and the possible therapeutic effects of N-acetyl cysteine (NAC), amifostine (AMF) and ascorbic acid (ASC) in methotrexate (MTX)-induced hepatotoxicity. METHODS: An MTX-induced hepatotoxicity model was established in 44 male Sprague Dawley rats by administration of a single intraperitoneal injection of 20 mg/kg MTX. Eleven of the rats were left untreated (Model group; n = 11), and the remaining rats were treated with a 7-d course of 50 mg/kg per day NAC (MTX + NAC group; n = 11), 50 mg/kg per single dose AMF (MTX + AMF group; n = 11), or 10 mg/kg per day ASC (MTX + ASC group; n = 11). Eleven rats that received no MTX and no treatments served as the negative control group. Structural and functional changes related to MTX- and the various treatments were assessed by histopathological analysis of liver tissues and biochemical assays of malondialdehyde (MDA), superoxide dismutase (SOD), catalase, glutathione (GSH) and xanthine oxidase activities and of serum levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and total bilirubin. RESULTS: Exposure to MTX caused structural and functional hepatotoxicity, as evidenced by significantly worse histopathological scores [median (range) injury score: control group: 1 (0-3) vs 7 (6-9), P = 0.001] and significantly higher MDA activity [409 (352-466) nmol/g vs 455.5 (419-516) nmol/g, P < 0.05]. The extent of MTX-induced perturbation of both parameters was reduced by all three cytoprotective agents, but only the reduction in hepatotoxicity scores reached statistical significance [4 (3-6) for NAC, 4.5 (3-5) for AMF and 6 (5-6) for ASC; P = 0.001, P = 0.001 and P < 0.005 vs model group respectively]. Exposure to MTX also caused a significant reduction in the activities of GSH and SOD antioxidants in liver tissues [control group: 3.02 (2.85-3.43) μmol/g and 71.78 (61.88-97.81) U/g vs model group: 2.52 (2.07-3.34) μmol/g and 61.46 (58.27-67.75) U/g, P < 0.05]; however, only the NAC treatment provided significant increases in these antioxidant enzyme activities [3.22 (2.54-3.62) μmol/g and 69.22 (61.13-100.88) U/g, P < 0.05 and P < 0.01 vs model group respectively]. CONCLUSION: MTX-induced structural and functional damage to hepatic tissues in rats may involve oxidative stress, and cytoprotective agents (NAC > AMF > ASC) may alleviate MTX hepatotoxicity. PMID:25110444

  15. Effect of bromide ions on genotoxicity of halogenated by-products from chlorination of humic acid in water.

    PubMed

    Nobukawa, T; Sanukida, S

    2001-12-01

    Genotoxicity of halogenated by-products obtained by chlorination of humic acid in water was evaluated in the presence of bromide ions (Br-). After the halogenated humic acid solution was made to flow through CSP800 cartridge, absorbed substances were eluted with dimethyl sulfoxide or acetone, and subjected to mutagenicity assays and to analysis of trihalomethanes (THMs). Mutagenic activity was measured by Ames tests using S. typhimurium TA100 strain without metabolic activation, and by the frequencies of micronuclei formation using cultured Chinese hamster lung cells (CHL/IU) in vitro. A powerful effect of bromide ions in chlorinated humic acid solutions was observed on the reverse mutation and micronuclei formations. The formations of total THMs and more brominated THMs were also enhanced in the presence of bromide ions. The ratio of [Br-/Cl-] regulated the composition and concentrations of THMs intensely, and the rate of substitution of Br- was greater than that of chloride ions (Cl-). The increments of the mutagenicity and total THMs formed in chlorinated solutions were observed in parallel with the concentration of Br- or Cl-. From the observations, it was concluded that the increasing mutagenicity might be caused by the increasing chlorinated and/or brominated by-products. PMID:11763030

  16. Comparative hepatotoxicity and clastogenicity of sodium arsenite and three petroleum products in experimental Swiss Albino Mice: the modulatory effects of Aloe vera gel.

    PubMed

    Gbadegesin, Michael A; Odunola, Oyeronke A; Akinwumi, Kazeem A; Osifeso, Olabode O

    2009-10-01

    Petroleum products (PPs) consist of complex chemical mixtures, mainly hydrocarbons. Their composition varies considerably with source and use. Inappropriate manual handling and use of PPs, in countries like Nigeria, results in excessive skin contact with the possibility of hazard to health. There has been inadequate evidence to classify diesel, kerosene and hydraulic oil as human carcinogens and there is limited evidence for their toxicity and carcinogenicity in experimental animals. We compared the hepatotoxicity and clastogenicity of diesel, petrol or hydraulic oil with that of sodium arsenite (Na(2)AsO(2)) in mice. Our findings showed that these PPs are capable of inducing gamma-glutamyl transferase (gammaGT) activity in the serum and liver to levels comparable with that induced by Na(2)AsO(2). Mice treated with individual PPs have elevated mean liver and serum gammaGT at levels that are significantly different from the values observed for the negative control group. Also, the individual PPs alone have micronuclei formation induction activity similar to Na(2)AsO(2). We found that treatment with Aloe vera gel before the PPs significantly reduced mean liver and serum gammaGT, and the mean number of micronuclei scored when compared with groups administered each of the PPs alone, supporting the presence of hepatoprotective components in Aloe vera. PMID:19583991

  17. Effect of Processing, Post-Harvest Irradiation, and Production System on the Cytotoxicity and Mutagenicity of Vitis labrusca L. Juices in HTC Cells

    PubMed Central

    Düsman, Elisângela; de Almeida, Igor Vivian; Lucchetta, Luciano; Vicentini, Veronica Elisa Pimenta

    2014-01-01

    The juices of grapes (Vitis labrusca L.) are similar to the fruit itself because the main constituents of the fruit are present in the juice. However, their quality characteristics may be modified by the harsh technological processes used for the production of integral food, such as production systems of raw materials and post-harvest treatment of grapes with ultraviolet (UV) irradiation. Therefore, the present study analyzed juices produced naturally (by liquefying the fruit) or by the technological process of extraction by steam distillation (90°C) of grapes from organic and conventional production systems that were untreated or treated with UV type C (65.6 J/m2 for 10 minutes). Using cultures of Rattus norvegicus hepatoma cells (HTC) in vitro, cytotoxic effects were assayed by the MTT test and by calculating the cytokinesis blocked proliferation index (CBPI), and mutagenic effects were measured by the cytokinesis block micronucleus assay. The results of the MTT assay and the CBPIs indicated that none of the juices were cytotoxic, including those that induced cell proliferation. The results of the micronucleus assay showed that none of the juices were mutagenic. However, the average number of micronuclei was lower in the juices produced from organic grapes, and cell proliferation, soluble acids and phenolic compounds were significantly higher. Compared with the natural juices, the integral juices of conventional grapes showed a higher average number of micronuclei as well as lower stimulation of cell proliferation and lower levels of bioactive compounds. The results demonstrate a beneficial effect of UV-C irradiation of post-harvest grapes in stimulating the synthesis of nutraceutical compounds without generating cytotoxic or mutagenic substances. Taken together, our findings support the consumption of grape juice and the application of food production techniques that enhance its nutritional value and promote its production, marketing and consumption. PMID

  18. Effects of Viscum album L. extract and quercetin on methotrexate-induced cyto-genotoxicity in mouse bone-marrow cells.

    PubMed

    Sekeroğlu, Zülal Atlı; Sekeroğlu, Vedat

    2012-07-01

    Viscum album, a semi-parasitic plant, has been used both in traditional and supplementary medicine in the treatment of many diseases. Quercetin (QE), one of the major flavonoids in some fruits and vegetables, has anti-oxidative and anti-carcinogenic activities. Methotrexate (MTX), an anti-folate anti-metabolite, is a widely used anti-neoplastic drug with significant clastogenic effects. The aim of this study was to investigate the anti-cytogenotoxic effects of pre-treatment with V. album extract (VAE) and QE on MTX-induced chromosomal aberrations (CAs) in mouse bone-marrow cells. Pre-treatment of mice by gavage with VAE (250mg/kgbw/day for 10 days) and QE (50mg/kgbw/day for 10 days) caused a significant decrease in CAs and in the number of aberrant cells with CAs induced by intramuscular treatment of the mice with MTX (10mg/kgbw/day for 3 days), when compared with the group treated with MTX alone. These compounds also significantly increased the mitotic index (MI) in bone-marrow cells that had been suppressed by MTX. In conclusion, from the findings we suggest that VAE and QE may play a role in reducing cyto-genotoxicity induced by anti-neoplastic drugs during cancer chemotherapy. PMID:22464986

  19. Repairing effects of interleukin 11 (IL-11) towards high dose methotrexate-induced rat small intestinal mucositis and its impacts on T-lymphoblastic leukemia cell line

    PubMed Central

    Han, Yueqin; Zhu, Yanping; Wang, Jinshen; Han, Yanqin; Qin, Daogang; Yang, Qiaozhi; Sun, Xiaojing; Chen, Lijun

    2016-01-01

    Objective(s): To investigate the efficacy of interleukin 11 (IL-11) towards the high dose methotrexate (HDMTX)-concurrent rat small intestinal mucositis and its impacts on the proliferation of the human T-lymphoblastic leukemia (CEM) cell line. Materials and Methods: 95 Wistar rats were randomly divided into five groups, the normal control group (A), the methotrexate (MTX) control group (B), the IL-11-pre-treated high-dose group (C), the post-IL-11-treatment high-dose group (D) and the post-IL-11-treatment low-dose group (E). After the intraperitoneal injection of MTX in the groups B-E, the rats were sacrificed at 1, 3, 5 and 7 days. The mortality, morphological and ultrastructural changes of small intestine of each group were observed. The cells were then cultured in vitro, and the MTT method was used to investigate the effects of different concentration of IL-11 on CEM proliferation and also on HDMTX-induced mucositis. Results: IL-11 could reduce the intestinal histopathological score, increase the height of small intestinal villi, promote the proliferation of intestinal lacunar cells and reduce the mortality rate of rats. The IL-11 pre-treatment group exhibited the best efficacies, demonstrating significant difference with the control group (P<0.01). In addition, the proliferation of CEM was not promoted, indicating that IL-11 could not inhibit HDMTX. Conclusion: IL-11 could reduce the severity of HDMTX-induced intestinal mucositis, and improve the survival rate of experimental rats, and could be safely used as the adjuvant treatment of HDMTX in childhood leukemia[PARANDCO1].

  20. Cytotoxic and genotoxic effects of beta-carotene breakdown products on primary rat hepatocytes.

    PubMed

    Alija, A J; Bresgen, N; Sommerburg, O; Siems, W; Eckl, P M

    2004-05-01

    According to Siems and colleagues, free radical attack on beta-carotene results in the formation of high amounts of cleavage products with prooxidant activities towards subcellular organelles such as mitochondria. This finding may be an explanation for the contradictory results obtained with beta-carotene in clinical efficacy and cancer prevention trials. Since primary hepatocytes proved to be very sensitive indicators of the genotoxic action of suspect mutagens/carcinogens we therefore investigated a beta-carotene cleavage products mixture (CP), apo8'- carotenal (apo8') and beta-carotene utilizing primary cultures of rat hepatocytes. The end-points tested were: the mitotic index, the percentage of necrotic and apoptotic cells, micronucleated cells, chromosomal aberrations and sister chromatid exchanges (SCE). Our results indicate a genotoxic potential of both CP and apo8' already at the concentrations 100 nM and 1 microM, i.e. at pathophysiologically relevant levels of beta-carotene and beta-carotene breakdown products. A 3 h treatment with CP induced statistically significant levels of micronuclei at concentrations of 0.1, 1 and 10 microM and chromosomal aberrations at concentrations of 1, 5 and 10 microM. Apo8' induced statistically significant levels of micronuclei at concentrations of 0.1, 1 and 5 microM and chromosomal aberrations at concentrations of 0.1, 1 and 10 microM. Statistically significant increases in SCE induction were only observed at a concentration of 10 microM CP and apo8'. In contrast, no significant cytotoxic effects of these substances were observed. Since beta-carotene induced neither significant cytotoxic nor genotoxic effects at concentrations ranging from 0.01 up to 10 microM, these observations indicate that most likely beta-carotene breakdown products are responsible for the occurrence of carcinogenic effects found in the Alpha-Tocopherol Beta-Carotene Cancer Prevention (ATBC) Study and the Beta-CArotene and RETinol Efficacy Trial

  1. Cytotoxicity of β-carotene cleavage products and its prevention by antioxidants.

    PubMed

    Alija, Avdulla J; Bresgen, Nikolaus; Bojaxhi, Ekramije; Vogl, Cornelia; Siems, Werner; Eckl, Peter M

    2010-01-01

    When we investigated the genotoxicity of beta-carotene cleavage products (CPs) in primary rat hepatocytes stimulated to proliferate, we observed dose-dependent increases of chromosomal aberrations, sister chromatid exchanges and micronuclei. In contrast to other genotoxic substances, however, this increased genotoxicity was not accompanied by increased cytotoxicity. As a consequence we observed metaphases showing massive chromosomal damage, indicating inhibition of apoptosis by CPs enabling these cells to proceed in the cell cycle. Since proliferative stimulation by growth factors may support this effect, the in vitro toxicological effects of CPs were studied on proliferatively quiescent primary rat hepatocytes. A significant increase of both apoptosis and necrosis was found. Supplementation with antioxidants did not significantly lower the level of apoptosis, while the level of necrosis was significantly reduced by Trolox and N-acetylcysteine at all concentrations tested as well as ascorbic acid (50 microM) and a combination of Trolox (50 microM) and ascorbic acid (50 microM). These observations indicate that a) the cytotoxic potential in combination with the genotoxic potential of CPs may promote the initiation of cells due to compensatory cell division in exposed tissues and may aggravate inflammatory processes under chronic exposure, and b) the applied antioxidants may protect from cytotoxicity primarily via the detoxification of aldehydic beta-carotene cleavage products. PMID:20532251

  2. Hydrogen production

    NASA Technical Reports Server (NTRS)

    England, C.; Chirivella, J. E.; Fujita, T.; Jeffe, R. E.; Lawson, D.; Manvi, R.

    1975-01-01

    The state of hydrogen production technology is evaluated. Specific areas discussed include: hydrogen production fossil fuels; coal gasification processes; electrolysis of water; thermochemical production of hydrogen; production of hydrogen by solar energy; and biological production of hydrogen. Supply options are considered along with costs of hydrogen production.

  3. Chromosome elimination and in vivo haploid production induced by Stock 6-derived inducer line in maize (Zea mays L.).

    PubMed

    Zhang, Zili; Qiu, Fazhan; Liu, Yongzhong; Ma, Kejun; Li, Zaiyun; Xu, Shangzhong

    2008-12-01

    In vivo haploid production induced by inducer lines derived from Stock 6 is widely used in breeding program of maize (Zea mays L.), but the mechanisms behind have not yet been fully understood. In this study, average frequency of haploid induction in four inbred lines by Stock 6-derived inducer line HZI1 was above 10%. About 0.2% kernels from the cross Hua24 x HZI1 had mosaic endosperm showing yellow shrunken parts from Hua24 to normal parts with purple aleurone from HZI1. Individual lagged chromosomes and micronuclei were observed in mitotic cells of ovules pollinated by HZI1. Above 56.4% of the radicles from the kernels with purple aleurone and colorless embryos were mixoploid (2n = 9-21), and more than 45.22% cells were haploid cells (2n = 10) in three crosses. More than 62.5% of the radicles from the kernels with purple aleurone and purple embryos were mixoploid (2n = 9-21) having 54.27% cells with 2n = 20. SSR analysis showed that all haploids from the cross Hua24 x HZI1 shared the same genomic compositions as Hua24 except for plants Nos. 862 and 857 with some polymorphic DNA bands. The results revealed that chromosome elimination after fertilization caused the haploid production in maize. PMID:18807046

  4. Genotoxicity of Advanced Glycation End Products: Involvement of Oxidative Stress and of Angiotensin II Type 1 Receptors

    NASA Astrophysics Data System (ADS)

    Schupp, Nicole; Schinzel, Reinhard; Heidland, August; Stopper, Helga

    2005-06-01

    In patients with chronic renal failure, cancer incidence is increased. This may be related to an elevated level of genomic damage, which has been demonstrated by micronuclei formation as well as by comet assay analysis. Advanced glycation end products (AGEs) are markedly elevated in renal failure. In the comet assay, the model AGEs methylglyoxal- and carboxy(methyl)lysine-modified bovine serum albumin (BSA) induced significant DNA damage in colon, kidney, and liver cells. The addition of antioxidants prevented AGE-induced DNA damage, suggesting enhanced formation of reactive oxygen species (ROS). The coincubation with dimethylfumarate (DMF), an inhibitor of NF-κB translocation, reduced the genotoxic effect, thereby underscoring the key role of NF-κB in this process. One of the genes induced by NF-κB is angiotensinogen. The ensuing proteolytic activity yields angiotensin II, which evokes oxidative stress as well as proinflammatory responses. A modulator of the renin-angiotensin system (RAS), the angiotensin II (Ang II) receptor 1 antagonist, candesartan, yielded a reduction of the AGE-induced DNA damage, connecting the two signal pathways, RAS and AGE signaling. We were able to identify important participants in AGE-induced DNA damage: ROS, NF-κB, and Ang II, as well as modulators to prevent this DNA damage: antioxidants, DMF, and AT1 antagonists.

  5. Production facilities

    SciTech Connect

    Not Available

    1989-01-01

    This book presents a cross section of different solutions to the many unique production problems operators face. Sections address benefit vs. cost options for production facility designs, oil and gas separation processes and equipment, oil treating and desalting systems, and water treating methods and equipment. Papers were selected to give an overall view of factors involved in optimizing the design of cost-effective production facilities.

  6. Agricultural Production.

    ERIC Educational Resources Information Center

    Lehigh County Area Vocational-Technical School, Schnecksville, PA.

    This brochure describes the philosophy and scope of a secondary-level course in agricultural production. Addressed in the individual units of the course are the following topics: careers in agriculture and agribusiness, animal science and livestock production, agronomy, agricultural mechanics, supervised occupational experience programs, and the…

  7. Productive Failure

    ERIC Educational Resources Information Center

    Kapur, Manu

    2008-01-01

    This study demonstrates an existence proof for "productive failure": engaging students in solving complex, ill-structured problems without the provision of support structures can be a productive exercise in failure. In a computer-supported collaborative learning setting, eleventh-grade science students were randomly assigned to one of two…

  8. Household Production.

    ERIC Educational Resources Information Center

    Scholl, Kathleen K.; And Others

    1982-01-01

    Compiled to give readers information on current research in household production, this special issue focuses on the family as a provider of goods and services. It includes five feature articles, a summary of a survey of American farm women, and a brief analysis of sources of time-use data for estimating the value of household production. Covered…

  9. Solvent Production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This article describes production of butanol [acetone-butanol-ethanol, (also called AB or ABE or solvent)] by fermentation using both traditional and current technologies. AB production from agricultural commodities such as corn and molasses was an important historical fermentation. Unfortunately,...

  10. Hydrogen Production

    SciTech Connect

    2014-09-01

    This 2-page fact sheet provides a brief introduction to hydrogen production technologies. Intended for a non-technical audience, it explains how different resources and processes can be used to produce hydrogen. It includes an overview of research goals as well as “quick facts” about hydrogen energy resources and production technologies.

  11. Ethanol Production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This book chapter reviews the current process technologies for fuel ethanol production. In the US, almost all commercial fuel ethanol is produced from corn whereas cane sugar is used almost exclusively in Brazil. In Europe, two major types of feedstock considered for fuel ethanol production are be...

  12. Household Products

    MedlinePlus

    The products you use for cleaning, carpentry, auto repair, gardening, and many other household uses can contain ingredients that can harm you, your family, and the environment. These include Oven and ...

  13. Household Products

    MedlinePlus

    The products you use for cleaning, carpentry, auto repair, gardening, and many other household uses can contain ingredients that can harm you, your family, and the environment. These include Oven and drain cleaners Laundry ...

  14. Environmental and biological monitoring of occupational formaldehyde exposure resulting from the use of products for hair straightening.

    PubMed

    Peteffi, Giovana Piva; Antunes, Marina Venzon; Carrer, Caroline; Valandro, Eduarda Trevizani; Santos, Sílvia; Glaeser, Jéssica; Mattos, Larissa; da Silva, Luciano Basso; Linden, Rafael

    2016-01-01

    The evaluation of formaldehyde (FD) exposure in beauty salons, due to the use of hair straightening products, and its relation with genotoxicity biomarkers was performed in this study. Regardless of official recommendations, the inappropriate use of homemade hair creams has became a popular practice in Brazil, and high formaldehyde content in the "progressive straightening" creams can contain mutagens that could increase the incidence of neoplasia in those people who use them. Damage to DNA was assessed by conducting a micronuclei test (MNT) on buccal cells and the comet assay on heparinized venous blood samples. A total of 50 volunteers were recruited at six different beauty salons (labeled A to F). At two salons that used products that did not contain FD (salons D and E), environmental FD concentrations were 0.04 and 0.02 ppm. In contrast, the products used at salons A, B, C, and F contained 5.7, 2.61, 5.9, and 5.79% of FD, and these salons had environmental FD concentrations of 0.07, 0.14, 0.16, and 0.14 ppm, respectively. Comparison of the beauty salon workers from each of the six beauty salons revealed significant differences in urinary formic acid (FA) concentration before exposure (p = 0.016), urinary FA after exposure (p = 0.004), variation in FA concentration before and after exposure (p = 0.018), environmental FD concentration (p < 0.001), cytogenetic damage detected by the comet assay according to both damage index (p < 0.001) and frequency of damage (p < 0.001), and for karyorrhexis only according to the MNT (p = 0.001). PMID:26351198

  15. Cellular regulation of poly ADP-ribosylation of proteins: II. Augmentation of poly(ADP-ribose) polymerase in SV40 3T3 cells following methotrexate-induced G1/S inhibition of cell cycle progression

    SciTech Connect

    Sooki-Toth, A.; Asghari, F.; Kirsten, E.; Kun, E. )

    1987-05-01

    SV40-3T3 cells were exposed in monolayer cultures to 5{times}10{sup {minus}7} M methotrexate (MTX), that inhibited thymidylate synthetase, arrested cell growth without cell killing in 24 h and did not induce single- (ss) or double-strand (ds) breaks in DNA. Following 24, up to 72 h, the poly(ADP-ribose) polymerase content of attached cells was induced by 5{times}10{sup {minus}7} MTX and the augmentation of the enzyme increased with the time of exposure to the drug. Inhibition of protein or RNA synthesis abolished augmentation of enzymatic activity; so too did the initiation of maximal cell growth by thymidine + hypoxanthine, by-passing the inhibitory site of MTX. Isolation of the ADP-ribosylated enzyme protein by gel electrophoresis identified poly(ADP-ribose) polymerase protein as the molecule that was induced by 5{times}10{sup {minus}7} M MTX. Under identical conditions, the poly(ADP-ribose) polymerase induction in 3T3 cells could not be demonstrated. A possible cell-cycle dependent biosynthesis of the enzyme protein is proposed in SV40 3T3 cells.

  16. Cordless Products

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Apollo-era technology spurred the development of cordless products that we take for granted everyday. In the 1960s, NASA asked Black Decker to develop a special drill that would be powerful enough to cut through hard layers of the lunar surface and be lightweight, compact, and operate under its own power source, allowing Apollo astronauts to collect lunar samples further away from the Lunar Experiment Module. In response, Black Decker developed a computer program that analyzed and optimized drill motor operations. From their analysis, engineers were able to design a motor that was powerful yet required minimal battery power to operate. Since those first days of cordless products, Black Decker has continued to refine this technology and they now sell their rechargeable products worldwide (i.e. the Dustbuster, cordless tools for home and industrial use, and medical tools.)

  17. Bottom production

    SciTech Connect

    Baines, J.; Baranov, S.P.; Bartalini, P.; Bay, A.; Bouhova, E.; Cacciari, M.; Caner, A.; Coadou, Y.; Corti, G.; Damet, J.; Dell-Orso, R.; De Mello Neto, J.R.T.; Domenech, J.L.; Drollinger, V.; Eerola, P.; Ellis, N.; Epp, B.; Frixione, S.; Gadomski, S.; Gavrilenko, I.; Gennai, S.; George, S.; Ghete, V.M.; Guy, L.; Hasegawa, Y.; Iengo, P.; Jacholkowska, A.; Jones, R.; Kharchilava, A.; Kneringer, E.; Koppenburg, P.; Korsmo, H.; Kramer, M.; Labanca, N.; Lehto, M.; Maltoni, F.; Mangano, M.L.; Mele, S.; Nairz, A.M.; Nakada, T.; Nikitin, N.; Nisati, A.; Norrbin, E.; Palla, F.; Rizatdinova, F.; Robins, S.; Rousseau, D.; Sanchis-Lozano, M.A.; Shapiro, M.; Sherwood, P.; Smirnova, L.; Smizanska, M.; Starodumov, A.; Stepanov, N.; Vogt, R.

    2000-03-15

    In the context of the LHC experiments, the physics of bottom flavoured hadrons enters in different contexts. It can be used for QCD tests, it affects the possibilities of B decays studies, and it is an important source of background for several processes of interest. The physics of b production at hadron colliders has a rather long story, dating back to its first observation in the UA1 experiment. Subsequently, b production has been studied at the Tevatron. Besides the transverse momentum spectrum of a single b, it has also become possible, in recent time, to study correlations in the production characteristics of the b and the b. At the LHC new opportunities will be offered by the high statistics and the high energy reach. One expects to be able to study the transverse momentum spectrum at higher transverse momenta, and also to exploit the large statistics to perform more accurate studies of correlations.

  18. Methyl-thiophanate increases reactive oxygen species production and induces genotoxicity in rat peripheral blood.

    PubMed

    Ben Amara, Ibtissem; Ben Saad, Hajer; Cherif, Boutheina; Elwej, Awatef; Lassoued, Saloua; Kallel, Choumous; Zeghal, Najiba

    2014-12-01

    Methylthiophanate is one of the widely used fungicides to control important fungal diseases of crops. The aim of this study was to elucidate the short-term hematoxicity and genotoxicity effects of methylthiophanate administered by intraperitoneal way at three doses (300, 500 and 700 mg/kg of body weight) after 24, 48 and 72 h. Our results showed, 24 h after methylthiophanate injection, a hematological perturbation such as red blood cells (p < 0.05, p < 0.05 and p < 0.01) and hemoglobin content (p < 0.05), respectively, and a noticeable genotoxic effect in WBC evidenced by a significant increase in the frequency of the micronuclei and a decrease in cell viability. An increase in erythrocyte osmotic fragility was also noted after 24 and 48 h of methylthiophanate treatment at graded doses. A significant increase in hydrogen peroxide, advanced oxidation of protein products and malondialdehyde levels, in erythrocytes of methylthiophanate-treated rats with 300, 500 and 700 mg/kg of body weight, was also observed after 24 h of treatment (p < 0.05, p < 0.01 and p < 0.001, respectively), suggesting the implication of oxidative stress in its toxicity. Antioxidants activities of superoxide dismutase and glutathione peroxidase in erythrocytes significantly increased (p < 0.001) 24 h after the highest dose injected. While all these parameters were improved after 72 h of methylthiophanate injection (300, 500 and 700 mg/kg body weight). In conclusion, these data showed that the exposure of adult rats to methylthiophanate resulted in oxidative stress leading to hematotoxicity and the impairment of defence system, confirming the pro-oxidant and genotoxic effects of this fungicide. PMID:25179310

  19. Genotoxic Effects in Swimmers Exposed to Disinfection By-products in Indoor Swimming Pools

    PubMed Central

    Kogevinas, Manolis; Villanueva, Cristina M.; Font-Ribera, Laia; Liviac, Danae; Bustamante, Mariona; Espinoza, Felicidad; Nieuwenhuijsen, Mark J.; Espinosa, Aina; Fernandez, Pilar; DeMarini, David M.; Grimalt, Joan O.; Grummt, Tamara; Marcos, Ricard

    2010-01-01

    Background Exposure to disinfection by-products (DBPs) in drinking water has been associated with cancer risk. A recent study (Villanueva et al. 2007; Am J Epidemiol 165:148–156) found an increased bladder cancer risk among subjects attending swimming pools relative to those not attending. Objectives We evaluated adults who swam in chlorinated pools to determine whether exposure to DBPs in pool water is associated with biomarkers of genotoxicity. Methods We collected blood, urine, and exhaled air samples from 49 nonsmoking adult volunteers before and after they swam for 40 min in an indoor chlorinated pool. We estimated associations between the concentrations of four trihalomethanes (THMs) in exhaled breath and changes in micronuclei (MN) and DNA damage (comet assay) in peripheral blood lymphocytes before and 1 hr after swimming; urine mutagenicity (Ames assay) before and 2 hr after swimming; and MN in exfoliated urothelial cells before and 2 weeks after swimming. We also estimated associations and interactions with polymorphisms in genes related to DNA repair or to DBP metabolism. Results After swimming, the total concentration of the four THMs in exhaled breath was seven times higher than before swimming. The change in the frequency of micronucleated lymphocytes after swimming increased in association with higher exhaled concentrations of the brominated THMs (p = 0.03 for bromodichloromethane, p = 0.05 for chlorodibromomethane, p = 0.01 for bromoform) but not chloroform. Swimming was not associated with DNA damage detectable by the comet assay. Urine mutagenicity increased significantly after swimming, in association with the higher concentration of exhaled bromoform (p = 0.004). We found no significant associations with changes in micronucleated urothelial cells. Conclusions Our findings support potential genotoxic effects of exposure to DBPs from swimming pools. The positive health effects gained by swimming could be increased by reducing the potential health

  20. Novolak Production

    NASA Astrophysics Data System (ADS)

    Aiba, Hiroshi

    Novolak resins are produced by reacting formaldehyde (30-55% concentration) with phenol under acidic conditions, with oxalic acid as the preferred catalyst and in special conditions, sulfuric acid. Depending on the batch size, all raw material components can be introduced into the reactor, or when there is an increase in the batch size as well as in the reactor volume, the reaction exotherm is controlled by a gradual addition of formaldehyde. Modern novolak production facilities are automated and programmed for reduced operational cost. A flow diagram of a general production line for the manufacture of novolak is shown. Recovery of the novolak is accomplished by the removal of water and devolatilization of crude novolak to molten, low-free phenol novolak resin which can be isolated as flake or pastille or dissolved in appropriate solvents. Novolak is stored either in a solid flake or pastille form or in solution. Most production is conducted under atmospheric conditions, but there are some recent, novel activities such as pressure in a hermetically-closed reactor reaching 0.1-10 MPa by using the heat of reaction without reflux to shorten reaction time, accelerating dehydration time by flash distillation, and providing economic benefit in the cost of novolak production.

  1. Transplant production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For field pepper (Capsicum spp.) production, plants can be established from direct seed or transplants depending on the location and cultural practices for the specific pepper type grown. Direct seeding can result in slow, variable, and reduced plant stands due to variations in soil temperature, wat...

  2. Secondary Products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In spite of their name, "secondary" products are essential for plant survival. They are required for basic cell functions as well as communicating the plant's presence to the surrounding environment and defense against pests as defined in the broad sense (i.e., diseases, nematodes, insects and plan...

  3. New Products.

    ERIC Educational Resources Information Center

    TechTrends, 1992

    1992-01-01

    Reviews new educational technology products, including a microcomputer-based tutoring system, laser barcode reader, video/data projectors, CD-ROM for notebook computers, a system to increase a printer's power, data cartridge storage shell, knowledge-based decision tool, video illustrator, interactive videodiscs, surge protectors, scanner system,…

  4. Tequila production.

    PubMed

    Cedeño, M

    1995-01-01

    Tequila is obtained from the distillation of fermented juice of agave plant, Agave tequilana, to which up to 49% (w/v) of an adjunct sugar, mainly from cane or corn, could be added. Agave plants require from 8 to 12 years to mature and during all this time cleaning, pest control, and slacken of land are required to produce an initial raw material with the appropriate chemical composition for tequila production. Production process comprises four steps: cooking to hydrolyze inulin into fructose, milling to extract the sugars, fermentation with a strain of Saccharomyces cerevisiae to convert the sugars into ethanol and organoleptic compounds, and, finally, a two-step distillation process. Maturation, if needed, is carried out in white oak barrels to obtain rested or aged tequila in 2 or 12 months, respectively. PMID:7736598

  5. Oil Production

    Energy Science and Technology Software Center (ESTSC)

    1989-07-01

    A horizontal and slanted well model was developed and incorporated into BOAST, a black oil simulator, to predict the potential production rates for such wells. The HORIZONTAL/SLANTED WELL MODEL can be used to calculate the productivity index, based on the length and location of the wellbore within the block, for each reservoir grid block penetrated by the horizontal/slanted wellbore. The well model can be run under either pressure or rate constraints in which wellbore pressuresmore » can be calculated as an option of infinite-conductivity. The model can simulate the performance of multiple horizontal/slanted wells in any geometric combination within reservoirs.« less

  6. Product separator

    DOEpatents

    Welsh, Robert A.; Deurbrouck, Albert W.

    1976-01-20

    A secondary light sensitive photoelectric product separator for use with a primary product separator that concentrates a material so that it is visually distinguishable from adjacent materials. The concentrate separation is accomplished first by feeding the material onto a vibratory inclined surface with a liquid flow, such as a wet concentrating table. Vibrations generally perpendicular to the stream direction of flow cause the concentrate to separate from its mixture according to its color. When the concentrate and its surrounding stream reach the recovery end of the table, a detecting device notes the line of color demarcation and triggers a signal if it differs from a normal condition. If no difference is noted nothing moves on the second separator. However, if a difference is detected in the constant monitoring of the color line's location, a product splitter and recovery unit normally positioned near the color line at the recovery end, moves to a new position. In this manner the selected separated concentrate is recovered at a maximum rate regardless of variations in the flow stream or other conditions present.

  7. Aqueous production.

    PubMed

    Krupin, T; Wax, M; Moolchandani, J

    1986-01-01

    The formation of aqueous humour by the ciliary body is a complex process. Active transport of solutes by the ciliary process epithelium is an energy-dependent mechanism that selectively transports substances against an electrochemical gradient across the cell membranes. Water passively follows the active solute transport. In addition to these active transport processes, ultrafiltration contributes to the formation of aqueous humour. The ciliary epithelium contains enzyme systems that function in the production of aqueous humour. The enzymes sodium-potassium-activated adenosine triphosphatase [(Na+:K+)ATPase] and carbonic anhydrase participate in the active transport across this epithelium. Inhibition of these enzymes lowers intraocular pressure (IOP) by decreasing aqueous humour production. the ciliary epithelium contains both alpha- and beta-adrenergic receptors. Electrophysiologic studies on the isolated iris-ciliary body (I-CB) preparation provide a means to study direct effects of the adrenergic agents on transepithelial properties of the ciliary epithelium. This paper will discuss the enzymatic and adrenergic properties of the ciliary epithelium as they relate to active transport and thereby aqueous humour production. PMID:3026067

  8. Fuel product

    SciTech Connect

    Christie, G.M.; Holmes, J.M.

    1985-01-22

    A coal fines log comprising a composite log made of a mixture of 90 to 98% coal particles having a size of roughly 10 microns, the log also containing paper and other cellulosic fibers such as bark in the range of 2 to 10% and grounded limestone is also provided in the log to neutralize the sulfur dioxide while burning. The log is contained in a hermetically sealed polyethylene envelope, the product so-formed is readily ignited and can sustain combustion over a relatively long period of time.

  9. Metallized Products

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Since the early 1960's, virtually all NASA spacecraft have used metallized films for a variety of purposes, principally thermal radiation insulation. King Seeley manufactures a broad line of industrial and consumer oriented metallized film, fabric, paper and foam in single layer sheets and multi-layer laminates. A few examples, commercialized by MPI Outdoor Safety Products, are the three ounce Thermos Emergency Blanket which reflects and retains up to 80 percent of the user's body heat helping prevent post accident shock or keeping a person warm for hours under emergency cold weather conditions.

  10. NULLJOB product

    SciTech Connect

    Hughart, N.; Ritchie, D.

    1987-05-01

    The ever increasing demand for more CPU cycles for data analysis on our Central VAX Cluster led us to investigate new ways to utilize more fully the resources that were available. A review of the experiment and software development VAX systems on site revealed many unused computing cycles. Furthermore, these systems were all connected by DECnet which would allow easy file transfer and remote batch job submission. A product was developed to allow jobs to be submitted on the Central VAX Cluster but actually to be run on one of the remote systems. The processing of the jobs was arranged, to the greatest extent possible, to be transparent to the user and to have minimal impact on both the Central VAX Cluster and remote systems.

  11. Software Products

    NASA Technical Reports Server (NTRS)

    1993-01-01

    MAST is a decision support system to help in the management of dairy herds. Data is collected on dairy herds around the country and processed at regional centers. One center is Cornell University, where Dr. Lawrence Jones and his team developed MAST. The system draws conclusions from the data and summarizes it graphically. CLIPS, which is embedded in MAST, gives the system the ability to make decisions without user interaction. With this technique, dairy managers can identify herd problems quickly, resulting in improved animal health and higher milk quality. CLIPS (C Language Integrated Production System) was developed by NASA's Johnson Space Center. It is a shell for developing expert systems designed to permit research, development and delivery on conventional computers.

  12. Production Density Diffusion Equation Propagation and Production

    NASA Astrophysics Data System (ADS)

    Shirai, Kenji; Amano, Yoshinori

    When we call the production flow to transition elements in the next step in the process of product manufactured one, the production flow is considered to be displaced in the direction of the unit production density. Density and production, as captured from different perspectives, also said production costs per unit of production. However, it is assumed that contributed to the production cost of manufacturing 100 percent. They may not correspond to the physical propagation conditions after each step of the production density, the equations governing the manufacturing process, which is intended to be represented by a single diffusion equation. We can also apply the concept of energy levels in statistical mechanics, production density function, in other words, in statistical mechanics “place” that if you use the world of manufacturing and production term. If the free energy in this production (potential) that are consuming the substance is nothing but the entropy production. That is, productivity is defined as the entropy production has to be. Normally, when we increase the number of production units, the product nears completion at year-end number of units completed and will aim to be delivered to the contractor from the turnover order. However, if you stop at any number of units, that will increase production density over time. Thus, the diffusion does not proceed from that would be irreversible. In other words, the congestion will occur in production. This fact and to report the results of analysis based on real data.

  13. Biological production of products from waste gases

    DOEpatents

    Gaddy, James L.

    2002-01-22

    A method and apparatus are designed for converting waste gases from industrial processes such as oil refining, and carbon black, coke, ammonia, and methanol production, into useful products. The method includes introducing the waste gases into a bioreactor where they are fermented to various products, such as organic acids, alcohols, hydrogen, single cell protein, and salts of organic acids by anaerobic bacteria within the bioreactor. These valuable end products are then recovered, separated and purified.

  14. By-Product Feeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    By-product feeds are generated from the production of food, fiber, and bio-energy products for human consumption. They include plant feedstuffs such as hulls, stalks, peels, and oil seed meals, and animal by-products such as blood meal, fats, bone meal, or processed organ meats. Some feed by-product...

  15. Product Structure, the Heart of Product Definition

    NASA Technical Reports Server (NTRS)

    DeHoog, C., Jr.

    1999-01-01

    This paper describes the LMMSS Product Definition System (PDS) philosophy and approach were the use of each item parts document or software can be traced to a specific end item (EI) serial/tail number of the product. It explains why a part-oriented approach to data organization and configuration management is required. The definition of part-oriented is that all appropriate product definition data products will be collected. Referenced and managed by their linkage/relationship to parts/items, The paper will touch upon how LMMSS store/controls product definition information under each project's top product designator in a two tiered approach. One tier for each product end item and another tier which contain/controls listings of drawings, documents. Specifications and standards that are required for hardware item definition.

  16. Household Products Database

    MedlinePlus

    ... Commercial / Institutional Product Names Types of Products Manufacturers Ingredients About the Database FAQ Product Recalls Help Glossary Contact Us More Resources What's under your kitchen sink, in your garage, in your bathroom, and ...

  17. Antibacterials in Household Products

    MedlinePlus

    ... products such as soaps, detergents, health and skincare products and household cleaners. How do antibacterials work? ♦ Antibacterials may be ... contain triclosan or other biocide agents? Antibacterials in household products Are there any risks associated with triclosan-containing ...

  18. Science and Product.

    ERIC Educational Resources Information Center

    Gomory, Ralph E.; Schmitt, Roland W.

    1988-01-01

    Defines incremental product development and discusses how this style of innovation effects technology industries. Cites examples of Japanese competition which emphasizes quality and speed in product development. Makes recommendations for the improvement of product development in the United States. (CW)

  19. Recombinant protein production technology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recombinant protein production is an important technology for antibody production, biochemical activity study, and structural determination during the post-genomic era. Limiting factors in recombinant protein production include low-level protein expression, protein precipitation, and loss of protein...

  20. Household Products Database: Pesticides

    MedlinePlus

    ... Names Types of Products Manufacturers Ingredients About the Database FAQ Product Recalls Help Glossary Contact Us More ... holders. Information is extracted from Consumer Product Information Database ©2001-2015 by DeLima Associates. All rights reserved. ...

  1. Eggs and Egg Products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The total U. S. egg production in 2009 was 78.5 billion table eggs, with 24 billion broken for the production of egg products. Shell eggs have many uses in homes, restaurants, and institutions, either alone or as ingredients in other foods. Egg products are also popular with consumers and are used i...

  2. Successful product realization strategies

    NASA Astrophysics Data System (ADS)

    Peeples, John; Boulton, William R.

    1995-02-01

    Product realization is the process of defining, designing, developing, and delivering products to the market. While the main thrust of this JTEC panel was to conduct a complete investigation of the state of Japanese low-cost electronic packaging technologies, it is very difficult to totally separate the development of technology and products from the product realization process. Japan's electronics firms adhere to a product realization strategy based on a strong customer focus, a consistent commitment to excellence in design, and a cost-effective approach to technology commercialization. The Japanese product-pull strategy has been a successful driver and influencing factor in every aspect of the product development cycle.

  3. Product engineering guide

    SciTech Connect

    McCarty, C.E.

    1989-12-01

    The semiconductor product engineers job requires knowledge and expertise related to many different subjects. This report provides guidance for newcomers to product engineering and is a consise reference for all others involved in product engineering. Subjects addressed are Customer/Supplier interactions, component development sequence, production schedule support, component characterization, product specifications, test equipment requirements, product qualification, characterization and development reports, preferred parts list, standard packaging, and finally, classification and security considerations. This guide is intended to help standardize and simplify the component development sequence presently used in the semiconductor product engineering department. 3 figs., 2 tabs.

  4. Successful product realization strategies

    NASA Technical Reports Server (NTRS)

    Peeples, John; Boulton, William R.

    1995-01-01

    Product realization is the process of defining, designing, developing, and delivering products to the market. While the main thrust of this JTEC panel was to conduct a complete investigation of the state of Japanese low-cost electronic packaging technologies, it is very difficult to totally separate the development of technology and products from the product realization process. Japan's electronics firms adhere to a product realization strategy based on a strong customer focus, a consistent commitment to excellence in design, and a cost-effective approach to technology commercialization. The Japanese product-pull strategy has been a successful driver and influencing factor in every aspect of the product development cycle.

  5. Production Function Geometry with "Knightian" Total Product

    ERIC Educational Resources Information Center

    Truett, Dale B.; Truett, Lila J.

    2007-01-01

    Authors of principles and price theory textbooks generally illustrate short-run production using a total product curve that displays first increasing and then diminishing marginal returns to employment of the variable input(s). Although it seems reasonable that a temporary range of increasing returns to variable inputs will likely occur as…

  6. Ex vivo bubble production from ovine large blood vessels: size on detachment and evidence of "active spots".

    PubMed

    Arieli, R; Marmur, A

    2014-08-15

    Nanobubbles formed on the hydrophobic silicon wafer were shown to be the source of gas micronuclei from which bubbles evolved during decompression. Bubbles were also formed after decompression on the luminal surface of ovine blood vessels. Four ovine blood vessels: aorta, pulmonary vein, pulmonary artery, and superior vena cava, were compressed to 1013 kPa for 21 h. They were then decompressed, photographed at 1-s intervals, and bubble size was measured on detachment. There were certain spots at which bubbles appeared, either singly or in a cluster. Mean detachment diameter was between 0.7 and 1.0 mm. The finding of active spots at which bubbles nucleate is a new, hitherto unreported observation. It is possible that these are the hydrophobic spots at which bubbles nucleate, stabilise, and later transform into the gas micronuclei that grow into bubbles. The possible neurological effects of these large arterial bubbles should be further explored. PMID:24933644

  7. Product assurance management and software product assurance

    NASA Technical Reports Server (NTRS)

    Schneider, C.; Borycki, G.; Panaroni, P.; Surbone, M.; Borcz, R.; Beddow, A. J.

    1991-01-01

    The evolution of software assurance is discussed. The definition and implementation of standards are considered. It is recommended that requirements be clarified at the start of a project. The need for quality assurance in hardware is identified as the coming trend in the production of high cost single units which call for eradication of all errors during the early stages of development. The need to apply quality assurance throughout the whole mission is stressed. The dangers of overpricing product assurance services is stressed.

  8. ACS Quicklook PDF products

    NASA Astrophysics Data System (ADS)

    Suchkov, Anatoly

    1999-12-01

    This report details the features of the ACS quicklook PDF products produced by the HST data pipeline. The requirements closely follow the design of paper products recommended by the Data Quality Committee, with appropriate changes required to fully support ACS.

  9. The Top 10 Products

    ERIC Educational Resources Information Center

    American School & University, 2008

    2008-01-01

    In 2008, American School & University showcased some of the hottest products in the industry. This article presents the 10 most requested, as determined by readers. Products include fluorescent lighting, concrete floor maintenance and exterior sheathing.

  10. Increasing productivity: Another approach

    SciTech Connect

    Norton, F.J.

    1996-06-10

    An engineering information (EI) and information technology (IT) organization that must improve its productivity should work to further its business goals. This paper explores a comprehensive model for increasing EI/IT productivity by supporting organizational objectives.

  11. Transformer Industry Productivity Slows.

    ERIC Educational Resources Information Center

    Otto, Phyllis Flohr

    1981-01-01

    Annual productivity increases averaged 2.4 percent during 1963-79, slowing since 1972 to 1.5 percent; computer-assisted design and product standardization aided growth in output per employee-hour. (Author)

  12. Equipment & New Products.

    ERIC Educational Resources Information Center

    Poitras, Adrian W., Ed.

    1979-01-01

    Reviews new science equipment and products for the laboratory. Includes hand-held calculators, fiberglass fume hoods, motorized microtomy, disposable mouse cages, and electric timers. Describes 11 products total. Provides manufacturer name, address, and price. (MA)

  13. Data Product Maturity

    Atmospheric Science Data Center

    2013-03-25

    ... document, maturity levels are provided separately for each scientific data set (SDS) included with the data files. The data product ... indiscriminate use of these data products as the basis for research findings, journal publications, and/or presentations.   ...

  14. Baryon production at PEP

    SciTech Connect

    Goldhaber, G.; Weiss, J.M.

    1981-09-01

    Measurements of inclusive ..lambda.. + anti ..lambda.. production for 1.0 less than or equal to p less than or equal to 10.0 GeV/c and p + anti p production for 0.4 less than or equal to p less than or equal to 2.0 GeV/c show significant baryon production in e/sup +/e/sup -/ annihilation at E/sub cm/ = 29 GeV. ..lambda.. + anti ..lambda.. production represents 0.2 ..lambda..'s or anti ..lambda..'s per PEP event while the observed p + anti p production implies all baryon-antibaryon pair production is occurring at least as often as 0.6 per event, depending on the yet to be measured p + anti p production at high momentum. Comparisons are made with the first theoretical attempts to account for baryon production at these energies.

  15. CALIPSO Data Products Catalog

    Atmospheric Science Data Center

    2013-11-12

    ... aerosol, and stratospheric subtypes The cloud layer fraction was added to the aerosol profile data products. The aerosol layer fraction and surface winds were added to the cloud profile data product. ...

  16. Rational forest productivity decline.

    PubMed

    MacLellan, James I; Carleton, T J

    2003-01-01

    A whole forest optimisation model was employed to examine economic behaviour as it relates to long term, forest productivity decline in the boreal forests of Ontario, Canada. Our productivity investment model (PIM) incorporated a choice between productivity decline as represented by a drop in forest Site Class, and a fee to 'maintain' site productivity. Sensitivity analysis was used to determine the point at which these fees exceeded the value of the differential in timber volume between upper and lower site classes. By varying discount rate, 'productivity investment frontiers' were constructed, which highlight the effects of the magnitude in productivity decline, maintenance fees, and harvest flow constraints upon the occurrence and schedule of productivity declines. In presenting this simple approach to exploring the effects of economic choice upon forest productivity decline, the phenomena of 'natural capital divestment' within forestry is described. PMID:12859006

  17. The new productivity challenge.

    PubMed

    Drucker, P F

    1991-01-01

    "The single greatest challenge facing managers in the developed countries of the world is to raise the productivity of knowledge and service workers," writes Peter F. Drucker in "The New Productivity Challenge." Productivity, says Drucker, ultimately defeated Karl Marx; it gave common laborers the chance to earn the wages of skilled workers. Now five distinct steps will raise the productivity of knowledge and service workers--and not only stimulate new economic growth but also defuse rising social tensions. PMID:10114929

  18. The EGRET data products

    NASA Technical Reports Server (NTRS)

    Mattox, J. R.; Bertsch, D. L.; Fichtel, C. E.; Hartman, R. C.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Kwok, P. W.; Lin, Y. C.; Mayer-Hasselwander, H. A.

    1992-01-01

    We describe the Energetic Gamma Ray Experiment Telescope (EGRET) data products which we anticipate will suffice for virtually all guest and archival investigations. The production process, content, availability, format, and the associated software of each product is described. Supplied here is sufficient detail for each researcher to do analysis which is not supported by extant software.

  19. Vocational Education and Productivity.

    ERIC Educational Resources Information Center

    Watson, Robert, Jr.

    Vocational education can contribute to an improved United States productivity by producing an effective work force. People together with technology are two major factors in improving productivity, and they must be integrated. Industry is in the forefront of the efforts to improve productivity. It has encouraged management in long-range strategic…

  20. MISR Regional SAMUM Products

    Atmospheric Science Data Center

    2016-08-24

    ... three types of MISR Regional products:  Radiance ,  Aerosol , and  Land Surface . Each product summarizes selected parameters ... Radiance/RQI field. Component Global Aerosol Product (CGAS): MI3DAER, MI3MAER, MI3QAER, MI3YAER ...

  1. MISR Regional VBBE Products

    Atmospheric Science Data Center

    2016-08-24

    ... three types of MISR Regional products:  Radiance ,  Aerosol , and  Land Surface . Each product summarizes selected parameters ... Radiance/RQI field. Component Global Aerosol Product (CGAS): MI3DAER, MI3MAER, MI3QAER, MI3YAER ...

  2. MISR Data Product Specifications

    Atmospheric Science Data Center

    2013-09-06

    ... which corresponds to the data product version. The  Science Data Product Guide  (PDF) describes a template for MISR science data ... 7, 10: updates for V4.0 software delivery Sections 1, 2: update applicable product versions Size (PDF):  11.1 Mb   ...

  3. Production of entomopathogenic nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Production technology is critical for the success of entomopathogenic nematodes (EPNs) in biological control. Production approaches include in vivo and in vitro methods (solid or liquid fermentation). For laboratory use and small scale field experiments, in vivo production of EPNs appears to be th...

  4. Nulcear materials production: Primer

    SciTech Connect

    Not Available

    1988-09-01

    The US Department of Energy's (DOE's) Office of Nuclear Materials Production (NMP) is responsible for managing the production and recovery of nuclear materials for national defense. NMP oversees the production of radioactive materials for government, commercial, industrial, and medical applications. This Primer is a general introduction to NMP's major activities.

  5. Choosing Safe Baby Products

    MedlinePlus

    ... to Know About Zika & Pregnancy Choosing Safe Baby Products KidsHealth > For Parents > Choosing Safe Baby Products Print A A A Text Size Even though ... nothing small or simple about their accessories! Selecting products for your baby can be confusing, especially with ...

  6. Pomegranate production and marketing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This book is relatively short, with 134 pages, 15 chapters, 52 figures, and 20 tables. It ranges from cultivar descriptions, production, biotic and abiotic challenges to production, to postharvest, aril and juice production, health benefits, and international trade. It contains great information and...

  7. Coal production 1989

    SciTech Connect

    Not Available

    1990-11-29

    Coal Production 1989 provides comprehensive information about US coal production, the number of mines, prices, productivity, employment, reserves, and stocks to a wide audience including Congress, federal and state agencies, the coal industry, and the general public. 7 figs., 43 tabs.

  8. Malnutrition and infection influence the peripheral blood reticulocyte micronuclei frequency in children.

    PubMed

    Cervantes-Ríos, Elsa; Ortiz-Muñiz, Rocío; Martínez-Hernández, Ana Lidia; Cabrera-Rojo, Lilián; Graniel-Guerrero, Jaime; Rodríguez-Cruz, Leonor

    2012-03-01

    Malnutrition is a serious public health problem that affects approximately one third of all children. Developing countries have the highest incidence of malnourished children, and approximately 60% of deaths that occur in children under five are directly related to malnutrition and associated diseases. The relationship between malnutrition and genetic damage has been widely studied in humans and animal models. The micronucleus (MN) assay is useful in detecting chromosome damage induced by several factors. The aim of this study was to evaluate the effects of infection and malnutrition on the frequency of MN in erythrocytes from the peripheral blood of well-nourished, uninfected (WN) and well-nourished, infected (WNI) children, and moderately malnourished (UNM) and severely malnourished (UNS) children, both with infection, using a flow cytometric analysis technique. The percentage of reticulocytes (RETs) was significantly higher (1.5-fold) in WNI children than well-nourished controls. In addition, the UNS group had a 2.2-fold increase in the percentage of RETs compared to the WNI group. The frequency of micronucleated reticulocytes (MN-RETs) was 2.5 times greater, in WNI group compared to the WN group. These frequencies were significantly higher (1.7- and 2.1-fold) in UNM and UNS, respectively, compared to the WNI group. The results suggest that infection and malnutrition induce DNA damage in children. PMID:22119781

  9. ANEUPLOIDIES AND MICRONUCLEI IN THE GERM CELLS OF MALE MICE OF ADVANCED AGE

    EPA Science Inventory

    The objective of this research was to determine whether the frequencies of chromosomally defective germ cells increased with age in male laboratory mice. wo types of chromosomal abnormalities were characterized: (1) testicular spermatid aneuploidy (TSA) as measured by a new metho...

  10. KINETOCHORE-STAINING OF SPERMATID MICRONUCLEI: STUDIES OF MICE TREATED WITH X-RADIATION OR ACRYLAMIDE

    EPA Science Inventory

    The rodent spermatid micronucleus (MN) assay was used in conjunction with immunofluorescent techniques to distinguish kinetochores in following exposure of mice to X-radiation or acrylamide. fter either treatment, modest increases in kinetochore-positive MN were observed. permati...

  11. Effect of transgene number of spontaneous and radiation-induced micronuclei in lacl transgenic mice

    SciTech Connect

    O`Loughlin, K.G.; Hamer, J.D.; Winegar, R.A.; Mirsalis, J.C.; Short, J.M.

    1994-12-31

    Lacl transgenic mice are widely used for the measurement of mutations in specific target issues. The lacl transgene is present in mice as 40 tandem repeats; this sequence is homozygous (contained in both copies of chromosome 5) in C57Bl/6 mice, and is hemizygous in B6C3F1 mice. Previous reports have indicated that tandem repeats can produce chromosome instability, fragile sites, and other effects. To determine whether the presence of the transgene effects micronucleus induction we compared the response of nontransgenic (NTR) to hemizygous (HEMI) transgenic B6C3F1 mice and to hemizygous and homozygous (HOMO) transgenic C57Bl/6 mice. Five mice/group were irradiated with 500 cGy from a {sup 137}Cs source. Bone marrow was harvested 24 hr after treatment and 2000 polychromatic erythrocytes (PCE) were analyzed per animal. The presence or absence of the lacl transgene had no effect in unirradiated mice on the percent of micronucleated PCE (MN) or on the ratio of PCE to total red blood cells for either strain: B6C3F1 mice had MN frequencies of 0.26% and 0.20% for NTR and HEMI mice, respectively; C57Bl/6 mice had MN frequencies of 0.34%, 0.32%, and 0.38% for NTR, HEMI, and HOMO mice, respectively. Radiation-induced micronucleus frequencies were significantly higher in HEMI lacl B6C3F1 mice (2.85%) than in NTR litter mates (1.59%); the converse was true in C57Bl/6 mice: NTR were 2.45%, HEMI were 1.25%, HOMO were 1.65%. These data suggest that the lacl transgene does not cause chromosome instability as measured by spontaneous micronucleus levels. However, the response of these transgenic mice to a variety of clastogenic agents needs to be investigated before they are integrated into standard in vivo assays for chromosome damage.

  12. Generalized Monotone Incremental Forward Stagewise Method for Modeling Count Data: Application Predicting Micronuclei Frequency

    PubMed Central

    Makowski, Mateusz; Archer, Kellie J

    2015-01-01

    The cytokinesis-block micronucleus (CBMN) assay can be used to quantify micronucleus (MN) formation, the outcome measured being MN frequency. MN frequency has been shown to be both an accurate measure of chromosomal instability/DNA damage and a risk factor for cancer. Similarly, the Agilent 4×44k human oligonucleotide microarray can be used to quantify gene expression changes. Despite the existence of accepted methodologies to quantify both MN frequency and gene expression, very little is known about the association between the two. In modeling our count outcome (MN frequency) using gene expression levels from the high-throughput assay as our predictor variables, there are many more variables than observations. Hence, we extended the generalized monotone incremental forward stagewise method for predicting a count outcome for high-dimensional feature settings. PMID:25983544

  13. MICRONUCLEI AND OTHER NUCLEAR ANOMALIES IN BUCCAL SMEARS: FIELD TEST IN SNUFF USERS

    EPA Science Inventory

    A revised protocol for the exfoliated cell micronucleus assay was ie d-teste in a population exposed to a genotoxic agent at levels associated with a significant increase in cancer risk. The standard assay involves microscope examination of epithelial smears 0 determine the preva...

  14. In situ monitoring of animal micronuclei before the operation of Daya Bay Nuclear Power Station

    SciTech Connect

    Y.N. Cai; H.Y. He; L.M. Qian; G.C. Sun; J.Y. Zhao

    1994-12-31

    Daya Bay Nuclear Power Station, a newly-built nuclear power station in southern mainland China, started its operation in 1993. We examined micro-nucleated cells of Invertibrate (Bivalves) and Vertibrate (Fish and Amphibia) in different spots within the 50km surroundings of the Power Station during 1986-1993. This paper reports the results of the investigation carried out in Dong Shan, a place 4.7km to the Power Station:Bivalves; Pteria martensil 5.1(1986),4.8(1988),4.8(1991),5,0(1993),Mytilus smardinus 4.7(1987),4.6(1988); Chamys nobilis 4.9(1987);4.9(1991),4.5(1992),4.5(1993). Fish; Therapon jarbua 0.48(1991),0.67(1992),0.47(1993). Amphibia; Bufo melanostictus 0.29 (1987), 0.34(1988),0.39(1992),0.39(1993). These results showed that the environmental situation, estimated by using the frequencies of micronucleated cells, was stable-there was no obvious chromosome damage in the animals studied. It was found that the incidence of micronucleated cells of Bivalves was higher than that of Fish and Amphibia, suggesting the epithelial cells to be more sensitive than peripheral erythrocytes to environmental genotoxic effects. The results of our studies for other spots will be reported afterward. These data can be used as the original background information to monitor the environment when the Nuclear Power Station is in operation.

  15. Cytogenetic biomonitoring of primary school children exposed to air pollutants: micronuclei analysis of buccal epithelial cells.

    PubMed

    Demircigil, Gonca Çakmak; Erdem, Onur; Gaga, Eftade O; Altuğ, Hicran; Demirel, Gülçin; Özden, Özlem; Arı, Akif; Örnektekin, Sermin; Döğeroğlu, Tuncay; van Doorn, Wim; Burgaz, Sema

    2014-01-01

    There is an increasing attempt in the world to determine the exposures of children to environmental chemicals. To analyze the genotoxic effect of air pollution, micronucleus (MN) assay was carried out in buccal epithelial cells (BECs) of children living in an urban city of Turkey. Children from two schools at urban-traffic and suburban sites were investigated in summer and winter seasons for the determination of BEC-MN frequency (per mille) and frequency of BEC with MN (per mille). The same children were also recruited for lung function measurements within a MATRA project ("Together Towards Clean Air in Eskisehir and Iskenderun") Measured NO2 and SO2 concentrations did not exceed the European Union (EU) limit levels either in urban-traffic or suburban regions. Higher O3 concentrations were measured in the suburban site especially in the summer period. Particulate matter (PM2.5 and PM10) levels which did not differ statistically between two regions were above the EU limits in general. Although BEC-MN frequencies of children living in the suburban sites were higher in general, the difference between two regions was not significant either in the summer or winter periods. BEC-MN frequencies of the urban-traffic children were found to be significantly higher in summer period (mean ± SD, 2.68 ± 1.99) when compared to winter period (1.64 ± 1.59; p = 0.004). On the other hand, no seasonality was observed for the suburban children. Similar results have been obtained in the BEC frequency with MN in our study. In summer, BEC-MN frequencies were significantly increased with the decrease in pulmonary function levels based on forced expiratory flow between 25 and 75% of vital capacity (FEF25-75%) levels (p < 0.05). As a conclusion, children living in urban-traffic and suburban areas in the city of Eskişehir exhibited similar genotoxicity. Seasonal variation in genotoxicity may be interpreted as relatively high ozone levels and increasing time spent at outdoors in the summer. PMID:23884878

  16. Anabolic androgenic steroids induce micronuclei in buccal mucosa cells of bodybuilders

    PubMed Central

    Torres‐Bugarín, O; Covarrubias‐Bugarín, R; Zamora‐Perez, A L; Torres‐Mendoza, B M G; García‐Ulloa, M; Martínez‐Sandoval, F G

    2007-01-01

    Objective To evaluate genotoxicity of anabolic androgenic steroids (AAS) in male bodybuilders by a micronucleus assay in buccal mucosa cells. Methods 11 male bodybuilders volunteered to participate in this study and two groups were formed: group 1 (n = 6), without AAS consumption and group 2 (n = 5), with AAS consumption. A sample of buccal epithelium was taken from each participant once a week for 6 weeks. Samples were fixed, stained and analysed by a light microscope, and 2000 cells were counted from each slide. Results are expressed as micronucleated cells (MNC) per 1000 cells and were analysed by the Mann–Whitney U test and Wilcoxon's test. Results A marked increased in MNC was seen in bodybuilders with AAS consumption compared with those without AAS consumption (mean (SD) 4.1 (2.4) MNC/1000 cells vs 0.4 (0.4) MNC/1000 cells, respectively; p<0.004). Intragroup comparisons showed no differences in the MNC frequencies during the sampling time in group 1, whereas the MNC frequency in group 2 varied significantly, reaching the highest MNC frequencies in the third and fourth week of sampling (5.9 (2.4) MNC/1000 cells; 5.8 (1.8) MNC/1000 cells, respectively); frequency in the first sampled week was 1.1 (0.1) MNC/1000 cells. Significant differences in all sampled weeks were found between the two groups. Conclusion AAS consumption increased the frequency of MNC from buccal mucosa in bodybuilders. PMID:17502334

  17. In vitro micronuclei tests to evaluate the genotoxicity of surface water under the influence of tanneries.

    PubMed

    Lemos, A O; Oliveira, N C D; Lemos, C T

    2011-06-01

    Leather manufacturing has a high potential for environmental pollution due to hides and chemicals that are not completely absorbed during the tanning process. This study aims to investigate the mutagenic potential of surface water samples from Cadeia and Feitoria rivers (RS, Brazil) in areas influenced by tanneries and leather footwear industry. Micronucleus assays using V79 cells and human lymphocytes were used. Cells were exposed to surface water collected bimonthly from three sites for a year, totaling six samples. Significant MN induction in human lymphocytes was shown by 83% of samples from sites FEI001 and CAD001 located downstream from the industrial area, followed by FEI004 (33%), upstream. Only a single sample from site FEI004 showed a positive response for MN in V79 cells. Thirteen discordant and five concordant responses were found between the two in vitro tests. Mutagenic agents were found at the sites where chemical quality was worst, corroborating studies on chronic toxicity, oxidative stress and mutagenicity performed in this area. The assay using human lymphocytes was more sensitive than V79 cells to detect the contaminants from this area, showing that it is an excellent biomarker of environmental genotoxicity. PMID:21238575

  18. Micronuclei and nuclear abnormalities in buccal mucosa cells in patients with anorexia and bulimia nervosa.

    PubMed

    Torres-Bugarín, Olivia; Pacheco-Gutiérrez, Angélica Guadalupe; Vázquez-Valls, Eduardo; Ramos-Ibarra, María Luisa; Torres-Mendoza, Blanca Miriam

    2014-11-01

    The aim of this study is to assess the frequency of micronucleated cell (MNC) and nuclear abnormalities (NA) in the buccal mucosa cells of females with anorexia nervosa (AN) or bulimia nervosa (BN), compared with healthy women. Individuals with AN and BN have inadequate feeding and compensatory behaviour to avoid weight gain. These behaviours can cause extreme body stress, thereby inducing DNA damage. In a cross-sectional study, we assessed the frequency of MNC and NA in the buccal mucosa cells of female participants with AN or BN. All of these patients had been admitted to a private clinic for the treatment of eating disorders after diagnosis with AN (n = 10) or BN (n = 7) according to the DSM-IV. Age-matched healthy female participants (n = 17) composed the control group. Oral mucosa samples were collected, fixed, stained by aceto-orcein/fast green and microscopically examined. Normal cells, MNC and NAs were counted within a 2000 cell sample. The results were analyzed with the Kruskal-Wallis and Mann-Whitney tests. Differences were observed in the frequency of MNC in healthy females (1.2±0.9) versus that of patients with AN (3.4±1.5) (P < 0.0001) and BN (4.1±2.2) (P < 0.001). No differences were found among these groups in terms of NA. AN and BN are related to the loss of genetic material through chromosomal fractures and/or damage to the mitotic spindle (i.e. possibly a result of a deficiency in DNA precursors). Self-imposed compensatory behaviours in AN and BN, such as severe food restriction, potential malnutrition, vomiting, use of diuretics and laxatives and acute exhaustive exercise, are possible inducers of MNC and genotoxic damage. Of these compensatory behaviours, only vomiting has not been linked to genotoxic damage. This is the first report in women with BN, which should be studied in the future. PMID:25232046

  19. Exposure to 915 MHz radiation induces micronuclei in Vicia faba root tips.

    PubMed

    Gustavino, Bianca; Carboni, Giovanni; Petrillo, Roberto; Paoluzzi, Giovanni; Santovetti, Emanuele; Rizzoni, Marco

    2016-03-01

    The increasing use of mobile phones and wireless networks raised a great debate about the real carcinogenic potential of radiofrequency-electromagnetic field (RF-EMF) exposure associated with these devices. Conflicting results are reported by the great majority of in vivo and in vitro studies on the capability of RF-EMF exposure to induce DNA damage and mutations in mammalian systems. Aimed at understanding whether less ambiguous responses to RF-EMF exposure might be evidenced in plant systems with respect to mammalian ones, in the present work the mutagenic effect of RF-EMF has been studied through the micronucleus (MN) test in secondary roots of Vicia faba seedlings exposed to mobile phone transmission in controlled conditions, inside a transverse electro magnetic (TEM) cell. Exposure of roots was carried out for 72h using a continuous wave (CW) of 915 MHz radiation at three values of equivalent plane wave power densities (23, 35 and 46W/m(2)). The specific absorption rate (SAR) was measured with a calorimetric method and the corresponding values were found to fall in the range of 0.4-1.5W/kg. Results of three independent experiments show the induction of a significant increase of MN frequency after exposure, ranging from a 2.3-fold increase above the sham value, at the lowest SAR level, up to a 7-fold increase at the highest SAR. These findings are in agreement with the limited number of data on cytogenetic effects detected in other plant systems exposed to mobile phone RF-EMF frequencies and clearly show the capability of radiofrequency exposure to induce DNA damage in this eukaryotic cell system. PMID:26476436

  20. Micronucleus test and erythropoiesis: effect of cobalt on the induction of micronuclei by mutagens.

    PubMed

    Suzuki, Y; Shimizu, H; Nagae, Y; Fukumoto, M; Okonogi, H; Kadokura, M

    1993-01-01

    The micronucleus test is used widely as an in vivo short-term assay for potential carcinogens. In the present study, results of the micronucleus test were affected by cobalt dichloride pretreatment. Cobalt dichloride was used to induce erythropoietin, a growth factor for erythropoiesis. The increase in mutagen-induced micronucleus response following cobalt pretreatment, therefore, may have been due to a change in the rate of erythropoiesis. The greatest interaction between cobalt pretreatment and mutagen treatment for the induction of micronucleated polychromatic erythrocytes (MPCE) occurred when mice were injected with 1,1-dimethylhydrazine (DMH) 12-24 hr after pretreatment with cobalt dichloride and killed 30 hr later. Increased sensitivity of the micronucleus test was attributable to the administration of mutagen during the differentiation and multiplication of erythroblast, which is presumed to have been accelerated by pretreatment with cobalt dichloride. An increased induction of MPCE in the bone marrow by two chemicals--benzo(a)pyrene, 2-naphthylamine--was also observed following pretreatment with cobalt dichloride. PMID:8359151

  1. Flow cytometric analysis of micronuclei in mammalian cell cultures: past, present and future.

    PubMed

    Avlasevich, Svetlana; Bryce, Steven; De Boeck, Marlies; Elhajouji, Azeddine; Van Goethem, Freddy; Lynch, Anthony; Nicolette, John; Shi, Jing; Dertinger, Stephen

    2011-01-01

    The relative simplicity of the in vitro micronucleus (MNvit) endpoint has made it amenable to several automated scoring approaches. Flow cytometry is one such scoring platform that has been successfully employed. This review describes the origins of the MNvit assay, as well as the evolution and properties of flow cytometry-based scoring systems. While the current state-of-the-art methods acquire micronucleus (MN) frequency data very efficiently, it is becoming clear that they also endow the assay with high information content. For instance, simultaneous with MN frequency determinations, several additional endpoints are acquired that provide insights into cytotoxicity, cell cycle perturbations and, in the event of MN induction, information about genotoxic mode of action. This review concludes with a discussion regarding data gaps and also recommendations for additional work that is needed to more fully realise the potential of flow cytometric MNvit scoring. PMID:21164196

  2. DIETARY FOLATE DEFICIENCY ENHANCES INDUCTION OF MICRONUCLEI BY ARSENIC IN MICE

    EPA Science Inventory

    Folate deficiency increases background levels of DNA damage and can enhance the genotoxicity of chemical agents. Arsenic, a known human carcinogen present in drinking water supplies around the world, induces chromosomal and DNA damage. The effect of dietary folate deficiency on...

  3. Radiation-induced micronuclei in human fibroblasts in relation to clonogenic radiosensitivity.

    PubMed Central

    O'Driscoll, M. C.; Scott, D.; Orton, C. J.; Kiltie, A. E.; Davidson, S. E.; Hunter, R. D.; West, C. M.

    1998-01-01

    As part of our programme for developing predictive tests for normal tissue response to radiotherapy, we have investigated the efficacy of the cytokinesis-block micronucleus (MN) assay as a means of detecting interindividual differences in cellular radiosensitivity. A study was made of nine fibroblast strains established from vaginal biopsies of pretreatment cervical cancer patients and an ataxia telangiectasia (A-T) cell strain. Cells were irradiated in plateau phase, replated and treated with cytochalasin B 24 h later. MN formation was examined 72 h after irradiation as the number of MN in 100 binucleate cells. The method yielded low spontaneous MN yields (<7 per 100 cells), and mean induced MN frequencies after 3.5 Gy varied between cell strains from 18 to 144 per 100 cells. However, in repeat experiments, considerable intrastrain variability was observed (CV = 32%), with up to twofold differences in MN yields, although this was less than interstrain variability (CV = 62%). An analysis was made of the relationship between MN results and previously obtained clonogenic survival data. There was a significant correlation between MN yields and clonogenic survival. However, when the A-T strain was excluded from the analysis, the correlation lost significance, mainly because of one slow-growing strain which was the most sensitive to cell killing but had almost the lowest MN frequency. With current methodology, the MN assay on human fibroblasts does not appear to have a role in predictive testing of normal tissue radiosensitivity. PMID:9862564

  4. Induction of micronuclei by alkaloids extracted from Senecio brasiliensis and stored for 23 years.

    PubMed

    Santos-Mello, R; Deimlimg, L I; Lauer Júnior, C M; Almeida, A

    2002-04-26

    In the present study, we report the results of an investigation on pyrrolizidine alkaloids extracted from Senecio brasiliensis (Sprengel) Less., which were stored for more than 23 years under variable conditions of temperature and humidity and exposed to light. Both the crude alkaloid (integerrimine+retrorsine+impurities) and pure integerrimine conserved the ability to induce acute toxicity in mice, leading to the death of the animals in less than 24h. The alkaloids also conserved the potential to induce significant increases in micronucleus frequencies in polychromatic erythrocytes of mouse bone marrow compared to the negative control. The administration of alkaloids to lymphocyte cultures blocked with cytochalasin-B showed no significant increase in micronucleus frequency in binucleated cells, probably due to the lack of a metabolic activation mechanism. However, an antimitotic effect was observed. PMID:11943607

  5. Micronuclei in neonates and children: effects of environmental, genetic, demographic and disease variables

    PubMed Central

    Holland, Nina; Fucic, Alexandra; Merlo, Domenico Franco; Sram, Radim; Kirsch-Volders, Micheline

    2011-01-01

    Children may be more susceptible to the effects of the environmental exposure and medical treatments than adults; however, limited information is available about the differences in genotoxic effects in children by age, sex and health status. Micronucleus (MN) assay is a well established method of monitoring genotoxicity, and this approach is thoroughly validated for adult lymphocytes by the Human Micronucleus Biomonitoring project (HUMN.org). Similar international undertaking is in progress for exfoliated buccal cells. Most of the MN studies in children are focused on analyses of lymphocytes but in the recent years, more investigators are interested in using exfoliated cells from the oral cavity and other cell types that can be collected non-invasively, which is particularly important in paediatric cohorts. The baseline MN frequency is relatively low in newborns and its assessment requires large cohorts and cell sample counts. Available results are mostly consistent in conclusion that environmental pollutants and radiation exposures lead to the increase in the MN frequency in children. Effects of medical treatments are less clear, and more studies are needed to optimise the doses and minimise genotoxicity without compromising therapy outcomes. Despite the recent progress in MN assay in children, more studies are warranted to establish the relationship between MN in lymphocytes and exfoliated cells, to clarify sex, age and genotype differences in baseline MN levels and the changes in response to genotoxicants. One of the most important types of MN studies in children are prospective cohorts that will help to clarify the predictive value of MN and other cytome end points for cancer and other chronic diseases of childhood and adulthood. Emerging ‘omic’ and other novel molecular technologies may shed light on the molecular mechanisms and biological pathways associated with the MN levels in children. PMID:21164182

  6. Flexible production systems

    NASA Astrophysics Data System (ADS)

    Chudakov, A. D.; Shchetinin, D. D.

    1986-03-01

    Flexible production systems are a technological tool design to automate multiple product line manufacturing. Flexible production systems provide an efficient means of organizing combined equipment operations and bring the production organization nearer to an unmanned arrangement or one requiring a limited number of workers. This is achieved by intensifying and automating manufacturing processes; coordinating the automated processes involved in warehousing and materials transport to maintain a tight production path; and using computers to automate production preparation and production control. The prerequisites for a change to these new production structures include numerical control NC tools and machining centers, power connection points for robots, automated conveying and warehousing systems controlled by microelectronic devices and control computer complexes consisting primarily of microprocessor-based units capable of controlling equipment via a direct connection and on a real-time basis. The types of flexible production systems in operation are divided into three groups: (1) flexible automated lines (GAL), (2) flexible production modules (GPM); and (3) flexible production complexes (GPK).

  7. Suomi Npp Products Performance

    NASA Astrophysics Data System (ADS)

    Zhou, L.

    2014-12-01

    A suite of Sensor Data Records (SDRs) and Environment Data Records (EDRs) is generated from the Joint Polar Satellite System (JPSS) operational environmental satellite system. The products include atmospheric, ocean, land surface and cryospheric products from the Visible Infrared Imaging Radiometer Suite (VIIRS); atmospheric sounding products from the Cross-track Infrared Sounder (CrIS) and the Advance Technology Microwave Sounder (ATMS); and ozone products from the Ozone Mapping and Profiler Suite (OMPS). These EDRs undergo a rigorous validation process and algorithm updates to achieve a product maturity needed for end user applications. Since the successful launch of Suomi National Polar Partnership (SNPP) satellite in October 2011, significant progresses have been made on calibration and validation of the SNPP data products. By far all products were publicly available and most products were ready for operational evaluation. Most products also are expected to meet requirements and work is underway to reach validated maturity status and fully operational use. Further developments and improvements of the algorithms for J1 have been planned based on the JPSS requirements and lessons learned from SNPP. Sensitivity and impact studies are performed as sensor test data become available. For the majority of data products, no significant changes in sensor input and corresponding sensor degradation are expected. However, the J1 products will undergo the same rigorous calibration and validation process as the S-NPP products once the on-orbit data are available. The schedule for the maturity of the J1 data products however is expected to be accelerated compared to that for S-NPP as lessons learned from the S-NPP mission will be applied to the J1 satellite data. In the presentation, we will provide an overview of the latest SNPP data products' quality status and the plan forward for JPSS-1 algorithm updates.

  8. 17 CFR 229.1204 - (Item 1204) Oil and gas production, production prices and production costs.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... production, by final product sold, of oil, gas, and other products. Disclosure shall be made by geographical... conversion to synthetic oil or gas, the product's production, transfer prices, and production costs should be... expressed in common units of production with oil, gas, and other products converted to a common unit...

  9. 17 CFR 229.1204 - (Item 1204) Oil and gas production, production prices and production costs.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... production, by final product sold, of oil, gas, and other products. Disclosure shall be made by geographical... conversion to synthetic oil or gas, the product's production, transfer prices, and production costs should be... expressed in common units of production with oil, gas, and other products converted to a common unit...

  10. Coal Production 1992

    SciTech Connect

    Not Available

    1993-10-29

    Coal Production 1992 provides comprehensive information about US coal production, the number of mines, prices, productivity, employment, productive capacity, and recoverable reserves to a wide audience including Congress, Federal and State agencies, the coal industry, and the general public. In 1992, there were 3,439 active coal mining operations made up of all mines, preparation plants, and refuse operations. The data in Table 1 cover the 2,746 mines that produced coal, regardless of the amount of production, except for bituminous refuse mines. Tables 2 through 33 include data from the 2,852 mining operations that produced, processed, or prepared 10 thousand or more short tons of coal during the period, except for bituminous refuse, and includes preparation plants with 5 thousand or more employee hours. These mining operations accounted for over 99 percent of total US coal production and represented 83 percent of all US coal mining operations in 1992.