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Sample records for micronucleus test complemented

  1. Complement Test

    Science.gov (United States)

    ... Salicylates Semen Analysis Serotonin Serum Free Light Chains Sex Hormone Binding Globulin (SHBG) Shiga toxin-producing Escherichia ... and forming complexes that respond to infections, non-self tissues (transplants), dead cells ... KJ. Complement determinations in human disease. Ann Allergy Asthma Immunol . 2004; ...

  2. Automatic analysis of the micronucleus test in primary human lymphocytes using image analysis.

    Science.gov (United States)

    Frieauff, W; Martus, H J; Suter, W; Elhajouji, A

    2013-01-01

    The in vitro micronucleus test (MNT) is a well-established test for early screening of new chemical entities in industrial toxicology. For assessing the clastogenic or aneugenic potential of a test compound, micronucleus induction in cells has been shown repeatedly to be a sensitive and a specific parameter. Various automated systems to replace the tedious and time-consuming visual slide analysis procedure as well as flow cytometric approaches have been discussed. The ROBIAS (Robotic Image Analysis System) for both automatic cytotoxicity assessment and micronucleus detection in human lymphocytes was developed at Novartis where the assay has been used to validate positive results obtained in the MNT in TK6 cells, which serves as the primary screening system for genotoxicity profiling in early drug development. In addition, the in vitro MNT has become an accepted alternative to support clinical studies and will be used for regulatory purposes as well. The comparison of visual with automatic analysis results showed a high degree of concordance for 25 independent experiments conducted for the profiling of 12 compounds. For concentration series of cyclophosphamide and carbendazim, a very good correlation between automatic and visual analysis by two examiners could be established, both for the relative division index used as cytotoxicity parameter, as well as for micronuclei scoring in mono- and binucleated cells. Generally, false-positive micronucleus decisions could be controlled by fast and simple relocation of the automatically detected patterns. The possibility to analyse 24 slides within 65h by automatic analysis over the weekend and the high reproducibility of the results make automatic image processing a powerful tool for the micronucleus analysis in primary human lymphocytes. The automated slide analysis for the MNT in human lymphocytes complements the portfolio of image analysis applications on ROBIAS which is supporting various assays at Novartis.

  3. Complement fixation test to C burnetii

    Science.gov (United States)

    ... complement fixation test; Coxiella burnetii - complement fixation test; C burnetii - complement fixation test ... a specific foreign substance ( antigen ), in this case, C burnetii . Antibodies defend the body against bacteria, viruses, ...

  4. Evaluation of river water genotoxicity using the piscine micronucleus test.

    Science.gov (United States)

    Ergene, Serap; Cavaş, Tolga; Celik, Ayla; Köleli, Nurcan; Aymak, Cemil

    2007-07-01

    The Berdan River, which empties into the Mediterranean Sea on the east coast of Turkey, receives discharges of industrial and municipal waste. In the present study, the in vivo piscine micronucleus (MN) test was used to evaluate the genotoxicity of water samples collected from different locations along the Berdan River. Nile tilapia (Oreochromis niloticus) were exposed in the laboratory for 2, 4, and 6 days, and micronuclei were evaluated in peripheral blood erythrocytes, gill cells, and caudal fin epithelial cells. A single dose of 5 mg/L cyclophosphamide was used as a positive control. In addition to micronuclei, nuclear abnormalities (NAs), such as binucleated cells and blebbed, notched, and lobed nuclei, were assessed in the erythrocytes, and chemical analyses were carried out to determine the amount of heavy metals in the water samples. MN and NA frequencies were significantly elevated (up to 2- to 3-fold) in fish exposed to river water samples taken downstream of potential discharges, and the elevated responses in gill and fin cells were related to the concentration of heavy metals in the water. MN frequencies (expressed as micronucleated cells/1,000 cells), in both treated and untreated fish, were greatest in gill cells (range: 0.80-3.70), and generally lower in erythrocytes (range: 0.50-2.80), and fin cells (range: 0.45-1.70). The results of this study indicate that the Berdan River is contaminated with genotoxic pollutants and that the genotoxicity is related to the discharge of wastes into the river water.

  5. Screening potential genotoxic effect of aquatic plant extracts using the mussel micronucleus test

    Directory of Open Access Journals (Sweden)

    Bettina Eck-Varanka

    2016-01-01

    Full Text Available Objective: To assess the genotoxic potential of selected aquatic macrophytes: Ceratophyllum demersum L. (hornwort, family Ceratophyllaceae, Typha angustifolia L. (narrowleaf cattail, family Typhaceae, Stratiotes aloides L. (water soldier, family Butomaceae, and Oenanthe aquatica (L. Poir. (water dropwort, family Umbelliferae. Methods: For genotoxicity assessment, the mussel micronucleus test was applied. Micronucleus frequency was determined from the haemolymph of Unio pictorum L. (painter’s mussel. In parallel, total and hydrolisable tannin contents were determined. Results: All plant extracts elucidated significant mutagenic effect. Significant correlation was determined between tannin content and mutagenic capacity. Conclusions: The significant correlation between genotoxicity as expressed by micronucleus frequency and tannin content (both total and hydrolisable tannins indicate that tannin is amongst the main compounds being responsible for the genotoxic potential. It might be suggested that genotoxic capacity of these plants elucidate a real ecological effect in the ecosystem.

  6. 40 CFR 798.5395 - In vivo mammalian bone marrow cytogenetics tests: Micronucleus assay.

    Science.gov (United States)

    2010-07-01

    ... Genetic Toxicity § 798.5395 In vivo mammalian bone marrow cytogenetics tests: Micronucleus assay. (a... and documented with data, only this one time point need be sampled. (ii) If a repeated treatment... slides, spread as a smear and stained. (2) Analysis. Slides shall be coded before microscopic analysis...

  7. Association between micronucleus frequency and cervical intraepithelial neoplasia grade in Thinprep cytological test and its significance.

    Science.gov (United States)

    Shi, Yong-Hua; Wang, Bo-Wei; Tuokan, Talaf; Li, Qiao-Zhi; Zhang, Ya-Jing

    2015-01-01

    A micronucleus is an additional small nucleus formed due to chromosomes or chromosomal fragments fail to be incorporated into the nucleus during cell division. In this study, we assessed the utility of micronucleus counting as a screening tool in cervical precancerous lesions in Thinprep cytological test smears under oil immersion. High risk HPV was also detected by hybrid capture-2 in Thinprep cytological test smears. Our results showed that micronucleus counting was significantly higher in high-grade squamous intraepithelial lesion (HSIL) and invasive carcinoma cases compared to low-grade squamous intraepithelial lesion (LSIL) and non-neoplastic cases. Receiver operating characteristic (ROC) curve analysis revealed that micronucleus counting possessed a high degree of sensitivity and specificity for identifying HSIL and invasive carcinoma. Cut-off of 7.5 for MN counting gave a sensitivity of 89.6% and a specificity of 66.7% (P = 0.024 and AUC = 0.892) for detecting HSIL and invasive carcinoma lesions. Multiple linear regression analysis showed that only HSIL and invasive cancer lesions not age, duration of marital life and number of pregnancy are significantly associated with MN counting. The positive rate of high risk HPV was distinctly higher in LSIL, HSIL and invasive cancer than that in non-neoplstic categories. In conclusions, MN evaluation may be viewed as an effective biomarker for cervical cancer screening. The combination of MN count with HPV DNA detection and TCT may serve as an effective means to screen precancerous cervical lesions in most developing nations.

  8. Evaluation of 10 aliphatic halogenated hydrocarbons in the mouse bone marrow micronucleus test.

    Science.gov (United States)

    Crebelli, R; Carere, A; Leopardi, P; Conti, L; Fassio, F; Raiteri, F; Barone, D; Ciliutti, P; Cinelli, S; Vericat, J A

    1999-03-01

    Ten halogenated aliphatic hydrocarbons (carbon tetrachloride, 1-chlorohexane, 2,3-dichlorobutane, 1,2-dichloroethane, 1,2-dichloroethylene, 1,3-dichloropropane, hexachloroethane, 1,1,2-trichloroethane, 1,2,3-trichloropropane and 1,1,3-trichloropropene), previously assayed in genetic assays in fungi, were evaluated in the mouse bone marrow micronucleus test in order to assess their genotoxicity in vivo. All chemicals were administered once i.p. at 40 and 70-80% of their respective LD50 to male and female CD-1 mice, 24 and 48 h before killing. All treatments produced evident clinical symptoms, but no marked depression of bone marrow proliferation. No statistically significant increases in the incidence of micronucleated polychromatic erythrocytes over the control values were observed at any sampling time with any of the 10 halogenated hydrocarbons assayed. The comparison of the results obtained in this study with the findings provided by in vitro micronucleus assays on the same chemicals, reported by other authors, indicate that mouse bone marrow is weakly sensitive to the genotoxic effects induced by halogenated hydrocarbons in other test systems. This suggests that the role of such an assay in carcinogen screening may be questionable for this chemical class. An examination of mouse bone marrow micronucleus test results with the halogenated aliphatic hydrocarbons classified as carcinogens by IARC supports this conclusion.

  9. Examination of Mutagenic Effects of GAL-57 Herbicide (Bentazone+Dicamba Using Mouse Micronucleus Test

    Directory of Open Access Journals (Sweden)

    Vesela Karan

    2007-01-01

    Full Text Available A micronucleus test was run to investigate mutagenic potential of the herbicide GAL-57, a formulated mixture of bentazone and dicamba.The test was applied to mice of both sexes (strain: CRL: NMRI BR and the herbicide (product was administered by gavage at 2000 mg/kg rate, twice within 24 hs. Cyclophosphamide (positive control was administered at 60 mg/kg, while distilled water as a solvent was negative control. The animals were sacrificed 24 hs after second treatment, their bone marrow cells isolated from femur, and effects evaluated.The data acquired showed that repeated treatment of mice with GAL-57 caused neither biological nor significant statistical increase in the number of micronuclei in treated animals. At the same time, the number of micronucleated polychromatic erythrocytes in the bone marrow of animals treated with cyclophosphamide (positive control showed a significant statistical increase. The results suggest that the herbicide product tested did not show any mutagenic activity under the conditions of mouse micronucleus test.

  10. Tradescantia micronucleus test indicates genotoxic potential of traffic emissions in European cities

    International Nuclear Information System (INIS)

    Klumpp, Andreas; Ansel, Wolfgang; Klumpp, Gabriele; Calatayud, Vicent; Garrec, Jean Pierre; He Shang; Penuelas, Josep; Ribas, Angela; Ro-Poulsen, Helge; Rasmussen, Stine; Sanz, Maria Jose; Vergne, Phillippe

    2006-01-01

    Urban atmospheres contain complex mixtures of air pollutants including mutagenic and carcinogenic substances such as benzene, diesel soot, heavy metals and polycyclic aromatic hydrocarbons. In the frame of a European network for the assessment of air quality by the use of bioindicator plants, the Tradescantia micronucleus (Trad-MCN) test was applied to examine the genotoxicity of urban air pollution. Cuttings of Tradescantia clone no. 4430 were exposed to ambient air at 65 monitoring sites in 10 conurbations employing a standardised methodology. The tests revealed an elevated genotoxic potential mainly at those urban sites which were exposed to severe car traffic emissions. This bioassay proved to be a suitable tool to detect local 'hot spots' of mutagenic air pollution in urban areas. For its use in routine monitoring programmes, however, further standardisation of cultivation and exposure techniques is recommended in order to reduce the variability of results due to varying environmental conditions. - The Tradescantia micronucleus test can be used to assess genotoxic potential at urban sites

  11. Tradescantia micronucleus test indicates genotoxic potential of traffic emissions in European cities

    Energy Technology Data Exchange (ETDEWEB)

    Klumpp, Andreas [Institute for Landscape and Plant Ecology (320), University of Hohenheim, 70593 Stuttgart (Germany)]. E-mail: aklumpp@uni-hohenheim.de; Ansel, Wolfgang [Institute for Landscape and Plant Ecology (320), University of Hohenheim, 70593 Stuttgart (Germany); Klumpp, Gabriele [Institute for Landscape and Plant Ecology (320), University of Hohenheim, 70593 Stuttgart (Germany); Calatayud, Vicent [Fundacion CEAM, Parque Tecnologico, c/Charles Darwin 14, 46980 Paterna, Valencia (Spain); Garrec, Jean Pierre [INRA Nancy, Laboratoire Pollution Atmospherique, 54280 Champenoux (France); He Shang [INRA Nancy, Laboratoire Pollution Atmospherique, 54280 Champenoux (France); Penuelas, Josep [Unitat Ecofisiologia CSIC-CEAB-CREAF, Universitat Autonoma de Barcelona, Ed. C, 08193 Bellaterra, Barcelona (Spain); Ribas, Angela [Unitat Ecofisiologia CSIC-CEAB-CREAF, Universitat Autonoma de Barcelona, Ed. C, 08193 Bellaterra, Barcelona (Spain); Ro-Poulsen, Helge [Botanical Institute, University of Copenhagen, Oster Farimagsgade 2D, 1353 Copenhagen K (Denmark); Rasmussen, Stine [Botanical Institute, University of Copenhagen, Oster Farimagsgade 2D, 1353 Copenhagen K (Denmark); Sanz, Maria Jose [Fundacion CEAM, Parque Tecnologico, c/Charles Darwin 14, 46980 Paterna, Valencia (Spain); Vergne, Phillippe [ENS Lyon and Lyon Botanical Garden, 46 Allee d' Italie, 69364 Lyon Cedex 07 (France)

    2006-02-15

    Urban atmospheres contain complex mixtures of air pollutants including mutagenic and carcinogenic substances such as benzene, diesel soot, heavy metals and polycyclic aromatic hydrocarbons. In the frame of a European network for the assessment of air quality by the use of bioindicator plants, the Tradescantia micronucleus (Trad-MCN) test was applied to examine the genotoxicity of urban air pollution. Cuttings of Tradescantia clone no. 4430 were exposed to ambient air at 65 monitoring sites in 10 conurbations employing a standardised methodology. The tests revealed an elevated genotoxic potential mainly at those urban sites which were exposed to severe car traffic emissions. This bioassay proved to be a suitable tool to detect local 'hot spots' of mutagenic air pollution in urban areas. For its use in routine monitoring programmes, however, further standardisation of cultivation and exposure techniques is recommended in order to reduce the variability of results due to varying environmental conditions. - The Tradescantia micronucleus test can be used to assess genotoxic potential at urban sites.

  12. Structural and numerical chromosome aberration inducers in liver micronucleus test in rats with partial hepatectomy.

    Science.gov (United States)

    Itoh, Satoru; Hattori, Chiharu; Nagata, Mayumi; Sanbuissho, Atsushi

    2012-08-30

    The liver micronucleus test is an important method to detect pro-mutagens such as active metabolites not reaching bone marrow due to their short lifespan. We have already reported that dosing of the test compound after partial hepatectomy (PH) is essential to detect genotoxicity of numerical chromosome aberration inducers in mice [Mutat. Res. 632 (2007) 89-98]. In naive animals, the proportion of binucleated cells in rats is less than half of that in mice, which suggests a species difference in the response to chromosome aberration inducers. In the present study, we investigated the responses to structural and numerical chromosome aberration inducers in the rat liver micronucleus test. Two structural chromosome aberretion inducers (diethylnitrosamine and 1,2-dimethylhydrazine) and two numerical chromosome aberration inducers (colchicine and carbendazim) were used in the present study. PH was performed a day before or after the dosing of the test compound in 8-week old male F344 rats and hepatocytes were isolated 4 days after the PH. As a result, diethylnitrosamine and 1,2-dimethylhydrazine, structural chromosome aberration inducers, exhibited significant increase in the incidence of micronucleated hepatocyte (MNH) when given either before and after PH. Colchicine and carbendazim, numerical chromosome aberration inducers, did not result in any toxicologically significant increase in MNH frequency when given before PH, while they exhibited MNH induction when given after PH. It is confirmed that dosing after PH is essential in order to detect genotoxicity of numerical chromosome aberration inducers in rats as well as in mice. Regarding the species difference, a different temporal response to colchicine was identified. Colchicine increased the incidence of MNH 4 days after PH in rats, although such induction in mice was observed 8-10 days after PH. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Genotoxicity assessment of cobalt chloride in Eisenia hortensis earthworms coelomocytes by comet assay and micronucleus test.

    Science.gov (United States)

    Ciğerci, İbrahim Hakkı; Ali, Muhammad Muddassir; Kaygısız, Şöhret Yüksek; Liman, Recep

    2016-02-01

    Cobalt and its different compounds are extensively used worldwide and considered as possible environmental pollutant. Earthworms are useful model organism and its different species are used to monitor soil pollution. No study has been found to detect cobalt chloride (CoCl2) genotoxicity in earthworms. So, current study aimed to evaluate CoCl2 induced genotoxicity in Eisenia hortensis earthworms coelomocytes by alkaline comet assay (CA) and micronucleus (MN) test. The earthworms (n = 10 for each group) were exposed to different series of CoCl2 concentrations (100 ppm, 200 ppm, 300 ppm, 400 ppm, 500 ppm, 600 ppm) to find LD50. The LD50 for CoCl2 was found at 226 ppm. Then, doses of LD50/2, LD50 and 2XLD50 for 48 h were used. CA and MN demonstrated the significant increase (P earthworms. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Fluorescence in situ hybridization in combination with the comet assay and micronucleus test in genetic toxicology

    Directory of Open Access Journals (Sweden)

    Hovhannisyan Galina G

    2010-09-01

    Full Text Available Abstract Comet assay and micronucleus (MN test are widely applied in genotoxicity testing and biomonitoring. While comet assay permits to measure direct DNA-strand breaking capacity of a tested agent MN test allows estimating the induced amount of chromosome and/or genome mutations. The potential of these two methods can be enhanced by the combination with fluorescence in situ hybridization (FISH techniques. FISH plus comet assay allows the recognition of targets of DNA damage and repairing directly. FISH combined with MN test is able to characterize the occurrence of different chromosomes in MN and to identify potential chromosomal targets of mutagenic substances. Thus, combination of FISH with the comet assay or MN test proved to be promising techniques for evaluation of the distribution of DNA and chromosome damage in the entire genome of individual cells. FISH technique also permits to study comet and MN formation, necessary for correct application of these methods. This paper reviews the relevant literature on advantages and limitations of Comet-FISH and MN-FISH assays application in genetic toxicology.

  15. Genotoxic, Cytotoxic, Antigenotoxic, and Anticytotoxic Effects of Sulfonamide Chalcone Using the Ames Test and the Mouse Bone Marrow Micronucleus Test.

    Directory of Open Access Journals (Sweden)

    Carolina Ribeiro E Silva

    Full Text Available Chalcones present several biological activities and sulfonamide chalcone derivatives have shown important biological applications, including antitumor activity. In this study, genotoxic, cytotoxic, antigenotoxic, and anticytotoxic activities of the sulfonamide chalcone N-{4-[3-(4-nitrophenylprop-2-enoyl]phenyl} benzenesulfonamide (CPN were assessed using the Salmonella typhimurium reverse mutation test (Ames test and the mouse bone marrow micronucleus test. The results showed that CPN caused a small increase in the number of histidine revertant colonies in S. typhimurium strains TA98 and TA100, but not statistically significant (p > 0.05. The antimutagenicity test showed that CPN significantly decreased the number of His+ revertants in strain TA98 at all doses tested (p 0.05. Additionally, CPN co-administered with MMC significantly increased PCE/NCE ratio at all doses tested, demonstrating its anticytotoxic effect. In summary, CPN presented genotoxic, cytotoxic, antigenotoxic, and anticytotoxic properties.

  16. Use of micronucleus test in the assessment of radiation effects in aquatic environments

    International Nuclear Information System (INIS)

    Araujo, Edvaldo F. de; Silva, Luanna R.S.; Lima, Pedro A. de S.; Amancio, Francisco F.; Melo, Ana Maria M. de A.; Silva, Edvane B. da; Silva, Ronaldo C. da

    2011-01-01

    The study of the effects of radioactive substances on the environment is accomplished by radioecology. This science has played an important role in combating all forms of pollution. The uncontrolled use of physical and chemical agents has been a concern for environmental regulatory agencies, due to the serious damage to ecosystems. Aquatic organisms are exposed to a variety of pollutants harmful to aquatic systems. The mollusks Biomphalaria glabrata has been featured as a bioindicator to possess characteristics such as short reproductive cycle ease of maintenance in the laboratory and low maintenance cost. The micronucleus assay has been shown to be a great test to identify mutagenic effects caused by physical and chemical agents. In this study the frequency of micronuclei in haemocytes of Biomphalaria glabrata exposed to high doses of 60 Co gamma radiation contributing to a further standardization of this test as an indicator of the presence of radioactive contamination in aquatic environments. The young adult snails of Biomphalaria glabrata were divided into groups and subjected to a dose of 0 (control), 40 and 60 Gy of gamma radiation. The results showed that snails irradiated with 40 Gy showed a smaller number of haemocytes, whereas those exposed to 60 Gy had a greater quantity of these cells compared to control group. It can be concluded that the morphological analysis and the frequency of micronuclei in haemocytes of Biomphalaria glabrata exposed to 60 Co gamma radiation may be used in studies of the action of high doses of radiation in aquatic environments (author)

  17. Biomonitoring of Serbian population revealed by CB micronucleus test before and after the bombing of Yugoslavia

    International Nuclear Information System (INIS)

    Joksic, G.; Stankovic, M.; Guc-Scekic, M.; Vranjes, A.

    2002-01-01

    The induction of micronuclei in mitotically active cells has been widely used and promoted as a biological marker of exposure to environmental toxins. Biomonitoring of population using cytochalasin block micronucleus test (CBMN) has been performed for 11 years in our country; the incidence of micronuclei was evaluated in many groups of occupationally exposed persons as well as healthy unexposed controls. The spontaneous frequency of MN per 1000 binucleated cells was 9±3 (mean±SD) for woman, 7±2 for men. The average incidence of micronuclei in lymphocytes of newborns was 5.3±0.6, in their mothers 15±3 per 1000 binucleated cells, respectively. After the bombing of Yugoslavia significantly higher incidence of micronuclei was found in all groups of examines: health adults and newborns. In healthy adults, the average incidence of micronuclei was 28.16±14.63; in young pregnant woman 25.3±5.02 and their foetuses 20.14±9.6 respectively. One year latter (2001) the incidence of MN declined in all adults but enhance in foetal blood lymphocytes. (author)

  18. Micronucleus test for radiation biodosimetry in mass casualty events: Evaluation of visual and automated scoring

    Energy Technology Data Exchange (ETDEWEB)

    Bolognesi, Claudia, E-mail: claudia.bolognesi@istge.i [Environmental Carcinogenesis Unit, National Cancer Research Institute, Largo R. Benzi 10, 16132 Genoa (Italy); Balia, Cristina; Roggieri, Paola [Environmental Carcinogenesis Unit, National Cancer Research Institute, Largo R. Benzi 10, 16132 Genoa (Italy); Cardinale, Francesco [Clinical Epidemiology Unit, National Cancer Research Institute, Largo R. Benzi 10, 16132 Genoa (Italy); Department of Health Sciences, University of Genoa, Genoa (Italy); Bruzzi, Paolo [Clinical Epidemiology Unit, National Cancer Research Institute, Largo R. Benzi 10, 16132 Genoa (Italy); Sorcinelli, Francesca [Environmental Carcinogenesis Unit, National Cancer Research Institute, Largo R. Benzi 10, 16132 Genoa (Italy); Laboratory of Genetics, Histology and Molecular Biology Section, Army Medical and Veterinary, Research Center, Via Santo Stefano Rotondo 4, 00184 Roma (Italy); Lista, Florigio [Laboratory of Genetics, Histology and Molecular Biology Section, Army Medical and Veterinary, Research Center, Via Santo Stefano Rotondo 4, 00184 Roma (Italy); D' Amelio, Raffaele [Sapienza, Universita di Roma II Facolta di Medicina e Chirurgia and Ministero della Difesa, Direzione Generale Sanita Militare (Italy); Righi, Enzo [Frascati National Laboratories, National Institute of Nuclear Physics, Via Enrico Fermi 40, 00044 Frascati, Rome (Italy)

    2011-02-15

    In the case of a large-scale nuclear or radiological incidents a reliable estimate of dose is an essential tool for providing timely assessment of radiation exposure and for making life-saving medical decisions. Cytogenetics is considered as the 'gold standard' for biodosimetry. The dicentric analysis (DA) represents the most specific cytogenetic bioassay. The micronucleus test (MN) applied in interphase in peripheral lymphocytes is an alternative and simpler approach. A dose-effect calibration curve for the MN frequency in peripheral lymphocytes from 27 adult donors was established after in vitro irradiation at a dose range 0.15-8 Gy of {sup 137}Cs gamma rays (dose rate 6 Gy min{sup -1}). Dose prediction by visual scoring in a dose-blinded study (0.15-4.0 Gy) revealed a high level of accuracy (R = 0.89). The scoring of MN is time consuming and requires adequate skills and expertise. Automated image analysis is a feasible approach allowing to reduce the time and to increase the accuracy of the dose estimation decreasing the variability due to subjective evaluation. A good correlation (R = 0.705) between visual and automated scoring with visual correction was observed over the dose range 0-2 Gy. Almost perfect discrimination power for exposure to 1-2 Gy, and a satisfactory power for 0.6 Gy were detected. This threshold level can be considered sufficient for identification of sub lethally exposed individuals by automated CBMN assay.

  19. Assessment of the genotoxicity of Cu and Zn in raw and anaerobically digested slurry with the Vicia faba micronucleus test

    OpenAIRE

    Marcato, Claire-Emmanuelle; Pinelli, Eric; Pourrut, Bertrand; Silvestre, Jérôme; Guiresse, Agnès Maritchù

    2009-01-01

    Genotoxicity of Cu and Zn was assessed by use of the micronucleus (MN) test on Vicia faba roots. Plants were exposed to various leachates of rawand anaerobically digested pig slurry, with maximum total concentrations of 200MCu and 600MZn. The results indicated stabilisation of the organic matter during anaerobic digestion of the slurry and bioconversion of some phytotoxic organic compounds (e.g. phenols or p-cresol), but did not showa relationship between Cu and Zn concentrations and MN fr...

  20. Evaluation of genetic alteration induced by radon gas using the micronucleus test (Tradescantia sp. clone KU-20)

    International Nuclear Information System (INIS)

    Bruschi, Armando L.; Azevedo, Heliana de; Macacini, Jose F.; Roque, Claudio V.

    2011-01-01

    The first observations over the existence of radon gas (Rn), initially known as 'thorium emanation', were carried out between the end of 19 th and beginning of 20 th centuries. A result of uranium-238 (U 238 ) radioactive decay, radon is a tasteless, odorless and colorless gas under room temperature, with a 3.825-day half life and particle α emission in its decay, and as final product of its disintegration, the stable lead-206 isotope (Pb 206 ). Being it is the gas with the highest density known, closed and poor ventilated environments are favorable to its accumulation, with its inhalation being the highest health risk. The use of vegetal bioindicators has shown to be excellent on the monitoring of air quality and on mutagenic potential of various pollutants contained in the atmosphere. Within this context, the objective of this study was to evaluate the micronucleus test application potential utilizing the Tradescantia sp. clone KU-20, in order to evaluate genetic alterations induced by radon gas. Stems of Tradescantia sp. clone KU-20, previously immerse in Hoagland solution, were introduced in a radon detection equipment's calibration chamber (Alphaguard), containing radium salt. Afterwards, the accommodated stems were exposed to radon gas (the average radon concentration was 7.639 KBq/m3) for 24 hours. The results demonstrated an increase on micronucleus formation (39.23 + 2.143 MCN/100 tetrads) in stems exposed in relation to the negative control (18.00 + 1.396 MCN/100 tetrads). The difference between the values indicated a significant increase on micronucleus frequency in the inflorescences subjected to radon gas. The presented results demonstrated the micronucleus test application potential using Tradescantia clone KU-20 to evaluate genetic effects induced by radon gas. (author)

  1. Evaluation of a liver micronucleus assay in young rats (III): a study using nine hepatotoxicants by the Collaborative Study Group for the Micronucleus Test (CSGMT)/Japanese Environmental Mutagen Society (JEMS)-Mammalian Mutagenicity Study Group (MMS).

    Science.gov (United States)

    Takasawa, Hironao; Suzuki, Hiroshi; Ogawa, Izumi; Shimada, Yasushi; Kobayashi, Kazuo; Terashima, Yukari; Matsumoto, Hirotaka; Aruga, Chinami; Oshida, Keiyu; Ohta, Ryo; Imamura, Tadashi; Miyazaki, Atsushi; Kawabata, Masayoshi; Minowa, Shigenori; Hayashi, Makoto

    2010-04-30

    We have been investigating a liver micronucleus assay to detect genotoxic chemicals using young rats for several years, and had established its advantages with respect to using autonomous proliferation of young rat hepatocytes. Nine chemicals known to induce hepatotoxic effects such as necrosis (2,6-dinitrotolune, bromobenzene, isoniazid, phenacetin, allyl alcohol and thioacetamide), cholestasis (chlorpromazine hydrochloride and alpha-naphthyl isothiocyanate) and oxidative stress (clofibrate) were selected for this study. A liver micronucleus assay was conducted in 4-week-old male F344 rats using two or three dose levels of test chemicals given orally by gavage to evaluate the compound's ability to induce micronucleated hepatocytes. Several of these test chemicals were additionally examined in a peripheral blood micronucleus assay conducted concurrently and in the same animals. The genotoxic rodent hepatocarcinogen, 2,6-dinitrotoluene showed a positive result in the liver micronucleus assay, but the nongenotoxic hepatocarcinogens, clofibrate and thioacetamide gave negative responses. Bromobenzene, known to produce DNA adducts but is noncarcinogenic in rodent liver, was judged equivocal in this assay. alpha-Naphthyl isothiocyanate is noncarcinogenic and showed negative response in the liver. The other four chemicals, known to be either noncarcinogenic or carcinogenic in other non-liver target organs, showed negative results in the liver micronucleus assay. Based on the results in the present study and previous report described above, it was concluded that this technique is able to effectively predict genotoxic rodent hepatocarcinogenicity, and does not give false positives due to hepatotoxicity. Copyright 2010 Elsevier B.V. All rights reserved.

  2. Alkaline Comet Assay and Micronucleus Test Parameters in Children Exposed to Diagnostic X-Ray Examination

    International Nuclear Information System (INIS)

    Gajski, G.; Geric, M.; Garaj-Vrhovac, V.; Milkovic, Dj.; Beck, N.; Ranogajec-Komor, M.; Miljanic, S.; Knezevic, Z.

    2011-01-01

    Chest radiograms represent the basic radiological examination of thorax and are the most frequently performed radiological diagnostic procedure in the child population. Understanding the risks of low doses of radiation is an important aspect in the risk benefit analysis in paediatric populations. To provide the best care for the young patients the effects of radiation should be minimized thus chest X-rays must be performed by highest standards to ensure that the young patient has the lowest risk possible. Since children are the most sensitive to radiation, there is a need for follow up of the young populations that receive these X-ray diagnostic examinations. Follow up would be especially advisable for children that are at higher risk of radiation induced damage, for example children with a predisposition to DNA damage, or for children that are constantly exposed to numerous radiological examinations due to their illness. In that manner, present study was undertaken to evaluate application of different dosimetry systems in conjunction with alkaline comet assay and micronucleus test for the assessment of different types of DNA and chromosomal alterations in child population exposed to acute diagnostic X-rays examination. For that purpose doses were measured using thermoluminescence (TL) and radiophotoluminescent (RPL) dosimetry systems. The study demonstrated that immediately after exposure to diagnostic X-irradiation, mean percentage of DNA in tail of the comets, which is indirect measures of DNA damage, was significantly changed. The same was noticed for mean total number of micronuclei as well. It was shown that children with pulmonary diseases subjected to diagnostic procedure develop a significant increase in mean total number of each measured parameter which are the biomarkers of genetic damage for carcinogenesis, than prior to diagnostic procedure and that interindividual differences exist for each monitored child. Our results show that genetic damage arises

  3. Cytochalasin-b micronucleus test of peripheral blood lymphocytes of Kozloduy NPP workers

    International Nuclear Information System (INIS)

    Hadjidekova, V.; Hristova, R.; Atanassova, P.; Stainova, A.; Popova, L.

    2006-01-01

    Full text: The cytokinesis-block micronucleus assay in peripheral blood lymphocytes was applied to evaluate occupational radiation exposure of 65 nuclear power plant workers. Blood samples were collected from 43 workers aged between 32-54 years, mean age 41,7 years. The accumulated radiation doses for each subject varied between 7,9 - 766,4 mSv, mean level of the whole group is 237,78 mSv. Controls were 22 healthy individuals, (13 male and 9 female), aged between 27-52 years, mean age 38,8 years, selected from the administrative staff. All subjects participating in this study were interviewed concerning health status, professional history, smoking habit and other aspects relevant to the study. At least 1000 binucleated cells were analysed per person. The detected frequencies of micronuclei in the control group were ranged between 4.0 and 23.5 per 1000 binucleated cells, with the average incidence yield of 12.16 ±5.59 %. The mean group value of the frequency of micronuclei in peripheral lymphocytes of exposed workers was found to be 18.46±6.72 % in 1000 cells. The difference between the mean frequency of micronuclei in the group of exposed subjects and the control group was statistically significant (P<0,001). The correlation coefficient for duration of employment and accumulated doses is 0,30 (P<0,05). After 1,5 Gy in vitro irradiation of peripheral blood from investigated workers and controls a decreased radiosensitivity of NPP workers is detected using micronucleus assay. Decreased radiosensitivity of the professionally exposed workers could be due to the phenomenon of adaptive response. Micronucleus assay in peripheral blood lymphocytes is useful approach in cytogenetic monitoring of occupationally exposed nuclear industry workers

  4. Biomonitoring of agricultural workers exposed to pesticide mixtures in Guerrero state, Mexico, with comet assay and micronucleus test.

    Science.gov (United States)

    Carbajal-López, Yolanda; Gómez-Arroyo, Sandra; Villalobos-Pietrini, Rafael; Calderón-Segura, María Elena; Martínez-Arroyo, Amparo

    2016-02-01

    The aim of this study was to evaluate the genotoxic effect of pesticides in exfoliated buccal cells of workers occupationally exposed in Guerrero, Mexico, using the comet assay and the micronucleus test. The study compared 111 agricultural workers in three rural communities (Arcelia 62, Ajuchitlan 13, and Tlapehuala 36), with 60 non-exposed individuals. All the participants were males. The presence of DNA damage was investigated in the exfoliated buccal cells of study participants with the comet assay and the micronucleus (MN) test; comet tail length was evaluated in 100 nuclei and 3000 epithelial cells of each individual, respectively; other nuclear anomalies such as nuclear buds, karyolysis, karyorrhexis, and binucleate cells were also evaluated. Study results revealed that the tail migration of DNA and the frequency of MN increased significantly in the exposed group, which also showed nuclear anomalies associated with cytotoxic or genotoxic effect. No positive correlation was noted between exposure time and tail length and micronuclei frequencies. No significant effect on genetic damage was observed as a result of age, smoking, and alcohol consumption. The MN and comet assay in exfoliated buccal cells are useful and minimally invasive methods for monitoring genetic damage in individuals exposed to pesticides. This study provided valuable data for establishing the possible risk to human health associated with pesticide exposure.

  5. Spontaneous micronucleus frequencies in human peripheral blood lymphocytes as a screening test for an individual variation in a different population and radiation-induced micronucleus induction

    International Nuclear Information System (INIS)

    Kang, Chang-Mo; Jeon, Hye-Jeong; Cho, Chul-Koo

    2004-01-01

    Our studies were to evaluate the role of epigenetic factors in the variation of radiosensitivity on human peripheral blood lymphocytes by measuring the frequencies of micronucleus (MN) from 293 healthy subjects of different population for assessing the radiation health risk in Korea. We analyzed the frequencies of both spontaneous and in vitro 60 Co γ-rays or 50MeV neutron-induced MNs. The frequencies of spontaneous NMs not only vary greatly between individuals, but also working or living areas. The increased levels of cells with spontaneous MNs were observed with an increasing age. The frequencies of spontaneous MNs were significantly higher in females than in males. For both sexes, MN frequency was significantly and positively correlated with age. Age and gender are the most important demographic variables impacting on the MN index. Donors who had ever smoked showed significantly increased frequencies of MNs compared to nonsmokers. The main lifestyle factors influencing the MN index in the subjects are correlated significantly and positively with smoke while measuring the spontaneous frequencies of micronuclei. Therefore, it is evident that with regard to the application of MN assay all future studies to evaluate the association between radiosensitivity and susceptibility for radiation health risks in different populations should take into account the effect of age, gender and lifestyle. For the dose-response study, the induced MNs were observed at all doses, and the numerical changes according to doses. The dose-response curves were fitted with a linear-quadratic forms of the dose, and the results were different for γ-rays and neutrons significantly. Neutrons were more effective than γ-rays in producing MN with a dose-dependent manner. The frequency of MN varies with dose. The RBE for a micronuclei was 2.37 ± 0.17. The results suggested that the MN assay have a high potential to ensure appropriate quality control and a standard documentation protocol, which

  6. Evaluating the genotoxic effects of workers exposed to lead using micronucleus assay, comet assay and TCR gene mutation test

    International Nuclear Information System (INIS)

    Chen Zhijian; Lou Jianlin; Chen Shijie; Zheng Wei; Wu Wei; Jin Lifen; Deng Hongping; He Jiliang

    2006-01-01

    To evaluate the genotoxic effects of lead (Pb) exposure, 25 workers in a workplace producing storage battery were monitored for three genetic end-points using micronucleus (MN) assay, comet assay and TCR gene mutation test. Twenty-five controls were matched with workers according to age, gender and smoking. The air Pb concentration in the workplace was 1.26 mg/m 3 . All subjects were measured for Pb concentration of blood by atom absorption spectrophotometry. The mean Pb concentration of blood in workers (0.32 mg/l) was significantly higher than that in controls (0.02 mg/l). The results of MN test showed that the mean micronuclei rate (MNR) and mean micronucleated cells rate (MCR) in workers were 9.04 ± 1.51 per mille and 7.76 ± 1.23 per mille , respectively, which were significantly higher than those (2.36 ± 0.42 per mille and 1.92 ± 0.31 per mille ) in controls (P -4 and 1.74 ± 0.17 x 10 -4 , respectively, there was no significant difference between workers and controls (P > 0.05). The results of our study indicated that the genetic damage was detectable in 25 workers occupationally exposed to lead

  7. Monotest in the complement fixation test: the Chorus system

    Directory of Open Access Journals (Sweden)

    Laura Meli

    2009-06-01

    Full Text Available The complement fixation test (CFT is a method used for the detection of antibodies against pathogens of infectious diseases, it has been proved to be a useful diagnostic method in the detection of acute disease in many medical laboratories.The test performed manually is time consuming and needs very skilled personnel.This study evaluates the automated Chorus CFT system with 87 serum samples in comparison with manual method using Virion-Serion reagents, against a panel of antigens, such as Adenovirus, Influenza A and B virus, Respiratory Syncythial Virus, Parainfluenza Mix, Mycoplasma Pneumoniae, and Echinococcus. The Chorus system includes standardized reagents and a monotest device to perform the single assay. In comparison to the manual CFT method, the correlation is 91.6% (7/83.The results obtained show that the automated Chorus system can be applied for detecting complement fixation antibodies against different infectious disease agents.

  8. Correlation of In Vivo Versus In Vitro Benchmark Doses (BMDs) Derived From Micronucleus Test Data: A Proof of Concept Study.

    Science.gov (United States)

    Soeteman-Hernández, Lya G; Fellows, Mick D; Johnson, George E; Slob, Wout

    2015-12-01

    In this study, we explored the applicability of using in vitro micronucleus (MN) data from human lymphoblastoid TK6 cells to derive in vivo genotoxicity potency information. Nineteen chemicals covering a broad spectrum of genotoxic modes of action were tested in an in vitro MN test using TK6 cells using the same study protocol. Several of these chemicals were considered to need metabolic activation, and these were administered in the presence of S9. The Benchmark dose (BMD) approach was applied using the dose-response modeling program PROAST to estimate the genotoxic potency from the in vitro data. The resulting in vitro BMDs were compared with previously derived BMDs from in vivo MN and carcinogenicity studies. A proportional correlation was observed between the BMDs from the in vitro MN and the BMDs from the in vivo MN assays. Further, a clear correlation was found between the BMDs from in vitro MN and the associated BMDs for malignant tumors. Although these results are based on only 19 compounds, they show that genotoxicity potencies estimated from in vitro tests may result in useful information regarding in vivo genotoxic potency, as well as expected cancer potency. Extension of the number of compounds and further investigation of metabolic activation (S9) and of other toxicokinetic factors would be needed to validate our initial conclusions. However, this initial work suggests that this approach could be used for in vitro to in vivo extrapolations which would support the reduction of animals used in research (3Rs: replacement, reduction, and refinement). © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology.

  9. Mutagenic effects of tributyltin and inorganic lead (Pb II on the fish H. malabaricus as evaluated using the comet assay and the piscine micronucleus and chromosome aberration tests

    Directory of Open Access Journals (Sweden)

    Ferraro Marcos Vinícius M.

    2004-01-01

    Full Text Available Genotoxicity studies on toxic metals and their organic compounds are very important, especially so in the investigation of the effects of these compounds on the aquatic environments where they tend to accumulate. The use of endemic aquatic organisms as biological sentinels has proved useful to environmental monitoring. We assessed the mutagenic potential of tributyltin (TBT and inorganic lead (PbII using samples of the fish Hoplias malabaricus (commonly called traíra using the comet assay and the piscine micronucleus and chromosome aberration tests. Eighteen H. malabaricus were acclimatized in three individual aquariums, each containing six fish, six fish being exposed to 0.3 mg/g of body weight (bw of TBT, six to 21 mg/g bw of PbII and six being used as controls. Exposure to TBT and PbII was achieved by feeding the fish every five days with Astyanax (a small fish that is part of the normal diet of H. malabaricus which had been injected with solutions of TBT, PbII or with water (the control group. After two months the H. malabaricus were sacrificed and their peripheral blood collected and subjected to the comet and micronucleus assays, the chromosome aberration assay being conducted using kidney-tissue. Although the comet assay showed now mutagenic effects at the lead concentrations used but encountered results with TBT, the micronucleus and chromosome aberrations assays both indicated that TBT and PbII are potentially mutagenic (p < 0.01, the micronucleus assay showing morphological alterations of the nucleus.

  10. Association between cervical lesion grade and micronucleus frequency in the Papanicolaou test

    Directory of Open Access Journals (Sweden)

    Caroline Tanski Bueno

    2014-09-01

    Full Text Available The aim of this study was to evaluate the association between the frequency of micronuclei (MN and the cellular changes detected in the conventional Papanicolaou test. One hundred and seventy-four Papanicolaou test smears with cellular changes were examined. MN screening was done in cytopathological smears by counting 1,000 cervical cells in a light microscope. MN frequencies were significantly higher in the group with cellular changes compared to the control group (p < 0.001. The mean MN frequencies were 0.95 ± 1.12 (mean ± SD in the control group (n = 223, 2.98 ± 1.20 in individuals with atypical squamous cells of undetermined significance (ASC-US (n = 50, 4.04 ± 1.45 in cervical intraepithelial neoplasia (CIN I (n = 52, 5.97 ± 1.83 in CIN II (n = 30, 7.29 ± 1.55 in CIN III (n = 17 and 8.64 ± 1.55 in invasive cancer (n = 25. These findings suggest that MN monitoring should be included as an additional criterion for the early detection of cytogenetic damage in routine examinations. This monitoring should be done in the same smear as used for cytopathological examination. More specific and systematic studies are necessary to confirm this proposal.

  11. In vivo micronucleus test as a biomarker of genotoxicity in free-range goats from suspected contaminated environment

    Directory of Open Access Journals (Sweden)

    Afusat Jagun Jubril

    2017-09-01

    Conclusion: The finding indicates the prevalence and frequency of micronucleus as a biomarker of genotoxicity and an indicator of exposure to environmental genotoxic subtances. Hence, this highlights the relevance of these goats as important sentinel animal model. These findings, therefore, serve as a preliminary data for further studies on the latent genotoxic environmental contaminants and their potential deleterious impact. [J Adv Vet Anim Res 2017; 4(3.000: 281-287

  12. Application of the micronucleus test and comet assay in Trachemys callirostris erythrocytes as a model for in situ genotoxic monitoring.

    Science.gov (United States)

    Zapata, Lina M; Bock, Brian C; Orozco, Luz Yaneth; Palacio, Jaime A

    2016-05-01

    Trachemys callirostris is a turtle species endemic to northern South America. In northern Colombia it occurs in the middle and lower Magdalena River drainage and its principal tributaries (lower Cauca and San Jorge rivers) and in other minor drainages such as the lower Sinú River. In recent years, industrial, agricultural, and mining activities have altered natural habitats in Colombia where this species occurs, and many of the pollutants released there are known to induce genetic alterations in wildlife species. The micronucleus test and comet assay are two of the most widely used methods to characterize DNA damage induced by physical and chemical agents in wildlife species, but have not been employed previously for genotoxic evaluations in T. callirostris. The goal of this study was to optimize these genotoxic biomarkers for T. callirostris erythrocytes in order to establish levels of DNA damage in this species and thereby evaluate its potential as a sentinel species for monitoring genotoxic effects in freshwater environments in northern Colombia. Both genotoxic techniques were applied on peripheral blood erythrocytes from 20 captive-reared T. callirostris individuals as a negative control, as well as from samples obtained from 49 individuals collected in Magangué (Magdalena River drainage) and 24 individuals collected in Lorica (Sinú River drainage) in northern Colombia. Negative control individuals exhibited a baseline frequency of micronuclei of 0.78±0.58 and baseline values for comet tail length and tail moment of 3.34±0.24µm and 10.70±5.5, respectively. In contrast, samples from both field sites exhibited significantly greater evidence of genotoxic effects for both tests. The mean MN frequencies in the samples from Magangué and Lorica were 8.04±7.08 and 12.19±12.94, respectively. The mean tail length for samples from Magangué and Lorica were 5.78±3.18 and 15.46±7.39, respectively. Finally, the mean tail moment for samples from Magangué and

  13. Cadmium chloride, benzo[a]pyrene and cyclophosphamide tested in the in vitro mammalian cell micronucleus test (MNvit) in the human lymphoblastoid cell line TK6 at Covance laboratories, Harrogate UK in support of OECD draft Test Guideline 487.

    Science.gov (United States)

    Fowler, Paul; Whitwell, James; Jeffrey, Laura; Young, Jamie; Smith, Katie; Kirkland, David

    2010-10-29

    The following genotoxic chemicals were tested in the in vitro micronucleus assay, at Covance Laboratories, Harrogate, UK in the human lymphoblastoid cell line TK6. Cadmium chloride (an inorganic carcinogen), benzo[a]pyrene (a polycyclic aromatic hydrocarbon requiring metabolic activation) and cyclophosphamide (an alkylating agent requiring metabolic activation) were treated with and without cytokinesis block (by addition of cytochalasin B). This work formed part of a collaborative evaluation of the toxicity measures recommended in the draft OECD Test Guideline 487 for the in vitro micronucleus test. The toxicity measures used, capable of detecting both cytostasis and cell death, were relative population doubling, relative increase in cell counts and relative cell counts for treatments in the absence of cytokinesis block, and replication index or cytokinesis blocked proliferation index in the presence of cytokinesis block. All of the chemicals tested gave significant increases in the percentage of micronucleated cells with and without cytokinesis block at concentrations giving approximately 60% toxicity (cytostasis and cell death) or less by all of the toxicity measures used. The outcomes from this series of tests support the use of relative increase in cell counts and relative population doubling, as well as relative cell counts, as appropriate measures of cytotoxicity for the non-cytokinesis blocked in the in vitro micronucleus assay. Copyright © 2010 Elsevier B.V. All rights reserved.

  14. Etoposide; colchicine; mitomycin C and cyclophosphamide tested in the in vitro mammalian cell micronucleus test (MNvit) in Chinese hamster lung (CHL) cells at Covance laboratories; Harrogate UK in support of OECD draft Test Guideline 487.

    Science.gov (United States)

    Fowler, Paul; Whitwell, James; Jeffrey, Laura; Young, Jamie; Smith, Katie; Kirkland, David

    2010-10-29

    The following genotoxic chemicals were tested in the in vitro micronucleus assay, at Covance Laboratories, Harrogate, UK in the Chinese hamster lung cell line CHL. Etoposide (a topoisomerase inhibitor), colchicine (an aneugen), mitomycin C (a DNA cross linking agent) and cyclophosphamide (an alkylating agent requiring metabolic activation) were treated with and without cytokinesis block (by addition of cytochalasin B). This work formed part of a collaborative evaluation of the toxicity measures recommended in the draft OECD Test Guideline 487 for the in vitro micronucleus test. The toxicity measures used, detecting both cytostasis and cell death, were relative population doubling, relative increase in cell counts and relative cell counts for treatments in the absence of cytokinesis block, and replication index or cytokinesis blocked proliferation index in the presence of cytokinesis block. All of the chemicals tested gave significant increases in the percentage of micronucleated cells with and without cytokinesis block at concentrations giving approximately 60% toxicity (cytostasis and cell death) or less by all of the toxicity measures used. The outcomes from this series of tests support the use of relative increase in cell counts and relative population doubling, as well as relative cell counts, as appropriate measures of cytotoxicity for the non-cytokinesis blocked in vitro micronucleus assay. Copyright © 2010 Elsevier B.V. All rights reserved.

  15. Lack of genotoxicity of potassium iodate in the alkaline comet assay and in the cytokinesis-block micronucleus test. Comparison to potassium bromate.

    Science.gov (United States)

    Poul, J M; Huet, S; Godard, T; Sanders, P

    2004-02-01

    Iodine could be added to the diet of human population in the form of iodide or iodate but iodate had not been adequately tested for genotoxicity and carcinogenicity. In the present study, genotoxic effects of potassium iodate were evaluated in vitro using the alkaline comet assay and the cytokinesis-block micronucleus assay on CHO cells and compared to halogenate salt analogues potassium bromate and chlorate and also to their respective reduced forms (potassium iodide, bromide and chloride). The results showed that the comet assay failed to detect the presence of DNA damage after a treatment of cells by potassium iodate for concentrations up to 10 mM. This absence of primary DNA damage was confirmed in the cytokinesis-block micronucleus assay. In the same way, results showed that potassium chlorate as well as potassium iodide, bromide and chloride did not induced DNA damage in the alkaline comet assay for doses up to 10 mM. By contrast, potassium bromate exposure led to an increase in both DNA damage and frequency of micronucleated cells. The repair of bromate-induced DNA damage was incomplete 24 h after the end of treatment. These results seem to indicate that potassium bromate would induce DNA damage by several mechanisms besides oxidative stress.

  16. 40 CFR 79.64 - In vivo micronucleus assay.

    Science.gov (United States)

    2010-07-01

    ... micronucleus assay. (a) Purpose. The micronucleus assay is an in vivo cytogenetic test which uses erythrocytes... that, because it contains RNA, can be differentiated by appropriate staining techniques from a normochromatic erythrocyte (NCE), which lacks RNA. In one to two days, a PCE matures into a NCE. (c) Test method...

  17. Genotoxic and Antigenotoxic Assessment of Chios Mastic Oil by the In Vitro Micronucleus Test on Human Lymphocytes and the In Vivo Wing Somatic Test on Drosophila.

    Directory of Open Access Journals (Sweden)

    Dimitris Vlastos

    Full Text Available Chios mastic oil (CMO, the essential oil derived from Pistacia lentiscus (L. var. chia (Duham, has generated considerable interest because of its antimicrobial, anticancer, antioxidant and other beneficial properties. In the present study, the potential genotoxic activity of CMO as well as its antigenotoxic properties against the mutagenic agent mitomycin-C (MMC were evaluated by employing the in vitro Cytokinesis Block MicroNucleus (CBMN assay and the in vivo Somatic Mutation And Recombination Test (SMART. In the in vitro experiments, lymphocytes were treated with 0.01, 0.05 and 0.10% (v/v of CMO with or without 0.05 μg/ml MMC, while in the in vivo assay Drosophila larvae were fed with 0.05, 0.10, 0.50 and 1.00% (v/v of CMO with or without 2.50 μg/ml MMC. CMO did not significantly increase the frequency of micronuclei (MN or total wing spots, indicating lack of mutagenic or recombinogenic activity. However, the in vitro analysis suggested cytotoxic activity of CMO. The simultaneous administration of MMC with CMO did not alter considerably the frequencies of MMC-induced MN and wing spots showing that CMO doesn't exert antigenotoxic or antirecombinogenic action. Therefore, CMO could be considered as a safe product in terms of genotoxic potential. Even though it could not afford any protection against DNA damage, at least under our experimental conditions, its cytotoxic potential could be of interest.

  18. Specificity of EIA immunoassay for complement factor Bb testing.

    Science.gov (United States)

    Pavlov, Igor Y; De Forest, Nikol; Delgado, Julio C

    2011-01-01

    During the alternative complement pathway activation, factor B is cleaved in two fragments, Ba and Bb. Concentration of those fragments is about 2 logs lower than of factor B present in the blood, which makes fragment detection challenging because of potential cross-reactivity. Lack of information on Bb assay cross-reactivity stimulated the authors to investigate this issue. We ran 109 healthy donor EDTA plasmas and 80 sera samples with both factor B immunodiffusion (The Binding Site) and Quidel Bb EIA assays. During the study it was shown that physiological concentrations of gently purified factor B demonstrated approximately 0.15% cross-reactivity in the Quidel Bb EIA assay. We also observed that Bb concentration in serum is higher than in plasma due to complement activation during clot formation which let us use sera as samples representing complement activated state. Our study demonstrated that despite the potential 0.15% cross-reactivity between endogenous factor B and cleaved Bb molecule, measuring plasma concentrations of factor Bb is adequate to evaluate the activation of the alternative complement pathway.

  19. 5-Fluorouracil, colchicine, benzo[a]pyrene and cytosine arabinoside tested in the in vitro mammalian cell micronucleus test (MNvit) in Chinese hamster V79 cells at Covance Laboratories, Harrogate, UK in support of OECD draft Test Guideline 487.

    Science.gov (United States)

    Whitwell, James; Fowler, Paul; Allars, Sarah; Jenner, Karen; Lloyd, Melvyn; Wood, Debbie; Smith, Katie; Young, Jamie; Jeffrey, Laura; Kirkland, David

    2010-10-29

    The reference genotoxic agents 5-fluorouracil (a nucleoside analogue, characterised by a steep dose response profile), colchicine (an aneugen that inhibits tubulin polymerisation), benzo[a]pyrene (a polycyclic aromatic hydrocarbon requiring metabolic activation) and cytosine arabinoside (a nucleoside analogue that inhibits the gap-filling step of excision repair) were tested in the in vitro micronucleus assay using the Chinese hamster V79 cell line at Covance Laboratories, Harrogate, UK. All chemicals were treated in the absence and presence of cytokinesis block (via addition of cytochalasin B) with this work forming part of a collaborative evaluation of the toxicity measures recommended in the draft OECD Test Guideline 487 on the In Vitro Mammalian Cell Micronucleus Test (MNvit). The toxicity measures used, detecting a possible combination of both cytostasis and cell death (though not cell death directly), were relative population doubling, relative increase in cell counts and relative cell counts for treatments in the absence of cytokinesis block, and replication index in the presence of cytokinesis block. All of the chemicals tested either gave marked increases in the percentage of micronucleated cells with and without cytokinesis block, or did not induce micronuclei at concentrations giving approximately 50-60% toxicity (cytostasis and cell death) or less by all of the toxicity measures used. The outcome from this series of tests supports the use of relative increase in cell counts and relative population doubling, as well as relative cell counts, as appropriate measures of cytotoxicity for the non-cytokinesis blocked in vitro micronucleus assay. Copyright © 2010 Elsevier B.V. All rights reserved.

  20. In vitro genotoxicity of neutral red after photo-activation and metabolic activation in the Ames test, the micronucleus test and the comet assay.

    Science.gov (United States)

    Guérard, Melanie; Zeller, Andreas; Singer, Thomas; Gocke, Elmar

    2012-07-04

    Neutral red (Nr) is relatively non-toxic and is widely used as indicator dye in many biological test systems. It absorbs visible light and is known to act as a photosensitizer, involving the generation of reactive oxygen species (type-I reaction) and singlet oxygen (type-II reaction). The mutagenicity of Nr was determined in the Ames test (with Salmonella typhimurium strains TA1535, TA97, TA98, TA98NR, TA100, and TA102) with and without metabolic activation, and with and without photo-activation on agar plates. Similarly to the situation following metabolic activation, photo-mutagenicity of Nr was seen with all Salmonella strains tested, albeit with different effects between these strains. To our knowledge, Nr is the only photo-mutagen showing such a broad action. Since the effects are also observed in strains not known to be responsive to ROS, this indicates that ROS production is not the sole mode of action that leads to photo-genotoxicity. The reactive species produced by irradiation are short-lived as pre-irradiation of an Nr solution did not produce mutagenic effects when added to the bacteria. In addition, mutagenicity in TA98 following irradiation was stronger than in the nitroreductase-deficient strain TA98NR, indicating that nitro derivatives that are transformed by bacterial nitroreductase to hydroxylamines appear to play a role in the photo-mutagenicity of Nr. Photo-genotoxicity of Nr was further investigated in the comet assay and micronucleus test in L5178Y cells. Concentration-dependent increases in primary DNA damage and in the frequency of micronuclei were observed after irradiation. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Test of micronucleus in lymphocytes with the cytokinesis-block like possible indicator of the answer of the patient to the radiotherapy

    International Nuclear Information System (INIS)

    Giorgio, Marina di; Nasazzi, Nora; Taja, Maria R.; Roth, Berta; Sardi, Mabel; Menendez, Pablo R.

    2001-01-01

    In order to evaluate the individual cytogenetic response to radiotherapy and its comparison with the clinical response, the cytokinesis-block micronucleus assay was applied to peripheral blood lymphocytes of patients with cervix cancer undergoing radiotherapy. The cytogenetic data were analysed using a mathematical model to evaluate the attenuation of the cytogenetic effect as a function of the time between a single exposure and blood sampling, estimating a cytogenetic recovery factor (k) that might correlate with the individual radiosensitivity, contributing with radiosensitivity tests of current use but applying a rapid methodology easy to implement in a routine clinical laboratory. Long term clinical observations could confirm the validity of k in expressing predisposition of the subject to develop delayed effects. (author)

  2. Evaluation of a liver micronucleus assay in young rats (IV): a study using a double-dosing/single-sampling method by the Collaborative Study Group for the Micronucleus Test (CSGMT)/Japanese Environmental Mutagen Society (JEMS)-Mammalian Mutagenicity Study Group (MMS).

    Science.gov (United States)

    Takasawa, Hironao; Suzuki, Hiroshi; Ogawa, Izumi; Shimada, Yasushi; Kobayashi, Kazuo; Terashima, Yukari; Matsumoto, Hirotaka; Oshida, Keiyu; Ohta, Ryo; Imamura, Tadashi; Miyazaki, Atsushi; Kawabata, Masayoshi; Minowa, Shigenori; Maeda, Akihisa; Hayashi, Makoto

    2010-04-30

    A collaborative study was conducted to evaluate whether a liver micronucleus assay using four-week-old male F344 rats can be used to detect genotoxic rat hepatocarcinogens using double-dosing with a single-sampling 4 days after the second dose. The assay methods were thoroughly validated by the seven laboratories involved in the study. Seven chemicals, 2,4-diaminotoluene, diethyl nitrosamine, p-dimethylaminoazobenzene, 1,2-dimethylhydrazine dihydrochloride, 2,4-dinitrotolunene, 2,6-dinitrotoluene and mitomycin C, known to produce positive responses in the single-dosing/triple-sampling method were selected for use in the present study, and each chemical was examined in two laboratories with the exception of 2,4-dinitrotolunene. Although several of the compounds were examined at lower doses for reasons of toxicity than in the single-dosing/triple-sampling method, all chemicals tested in the present study induced micronuclei in liver cells indicating a positive result. These findings suggest that the liver micronucleus assay can be used in young rats to detect genotoxic rat hepatocarcinogens using a double-dosing/single-sampling procedure. Further, the number of animals used in the liver micronucleus assay can be reduced by one-third to a half by using the double-dosing/single-sampling method. This reduction in animal numbers also has significant savings in time and resource for liver perfusion and hepatocyte isolation. Copyright 2010 Elsevier B.V. All rights reserved.

  3. Flow cytometric determination of micronucleus frequency.

    Science.gov (United States)

    Elhajouji, Azeddine; Lukamowicz-Rajska, Magdalena

    2013-01-01

    During the last two decades the micronucleus (MN) test has been extensively used as a genotoxicity screening tool of chemicals and in a variety of exploratory and mechanistic investigations. The MN is a biomarker for chromosomal damage or mitotic abnormalities, since it can originate from chromosome fragments or whole chromosomes that fail to be incorporated into daughter nuclei during mitosis (Fenech et al., Mutagenesis 26:125-132, 2011; Kirsch-Volders et al., Arch Toxicol 85:873-899, 2011). The simplicity of scoring, accuracy, amenability to automation by image analysis or flow cytometry, and readiness to be applied to a variety of cell types either in vitro or in vivo have made it a versatile tool that has contributed to a large extent in our understanding of key toxicological issues related to genotoxins and their effects at the cellular and organism levels. Recently, the final acceptance of the in vitro MN test guideline 487 (OECD Guideline for Testing of Chemicals, In vitro mammalian cell micronucleus test 487. In vitro mammalian cell micronucleus test (MNVIT). Organization for Economic Cooperation and Development, Paris, 2010) together with the standard in vivo MN test OECD guideline 474 (OECD Guideline for The Testing of Chemicals, Mammalian erythrocyte micronucleus test no. 474. Organization for Economic Cooperation and Development, Paris, 1997) will further position the assay as a key driver in the determination of the genotoxicity potential in exploratory research as well as in the regulatory environment. This chapter covers to some extent the protocol designs and experimental steps necessary for a successful performance of the MN test and an accurate analysis of the MN by the flow cytometry technique.

  4. Micronucleus test of varying amounts of potassium bromate (KBrO3) on the meristematic cells of Allium cepa var. aggregatum root tips

    International Nuclear Information System (INIS)

    Cajigal Romnick, M.; Somera, Leomerto A.

    1999-03-01

    Four hundred twenty onion bulbs of the multiplier variety Allium cepa var. aggregatum were used as test materials to assay the micronucleus induction capacity of potassium bromate doses of 0, 5, 10, 25, 50, 75, and 100 parts per million. Microscopic analyses were done using onion root tips prepared according to a modified technique of Medina (1994). These analyses were done on root tips taken from onions grown in KBrO 3 for three days and for five days. The study was conducted following a completely randomized design and the data were statistically analyzed using a non-parametric equivalent of the analysis of variance. A significant amount of micronucleated cells (MCN) were found among treated onions compared with the almost non-occurrence in the control groups (0 ppm). The Kruskal-Wallis H-test and the Wilcoxon two-samples tests revealed significant differences among treatment means and that a significant increase in the number of MCN occurs as the dose of KBr0 3 increased in both day experiments. Results from the higher doses of 50, 75, and 100 ppm were found to be significantly the same for the day 3 experiments while those of the day 5 higher doses are characterized by lack of clear cellular and nuclear outline such that scoring is difficult. Differences in MCN averages for the day 3 and 5 experiments appear to be insignificant. However, day 3 results show averages that are more significantly different from each other. These prove that the MCN can be used as an efficient and time-saving parameter for the allium test of chemicals with chromosome breaking capacities. (Author)

  5. Micronucleus test of varying amounts of potassium bromate (KBrO{sub 3}) on the meristematic cells of Allium cepa var. aggregatum root tips

    Energy Technology Data Exchange (ETDEWEB)

    Cajigal Romnick, M; Somera, Leomerto A

    1999-03-01

    Four hundred twenty onion bulbs of the multiplier variety Allium cepa var. aggregatum were used as test materials to assay the micronucleus induction capacity of potassium bromate doses of 0, 5, 10, 25, 50, 75, and 100 parts per million. Microscopic analyses were done using onion root tips prepared according to a modified technique of Medina (1994). These analyses were done on root tips taken from onions grown in KBrO{sub 3} for three days and for five days. The study was conducted following a completely randomized design and the data were statistically analyzed using a non-parametric equivalent of the analysis of variance. A significant amount of micronucleated cells (MCN) were found among treated onions compared with the almost non-occurrence in the control groups (0 ppm). The Kruskal-Wallis H-test and the Wilcoxon two-samples tests revealed significant differences among treatment means and that a significant increase in the number of MCN occurs as the dose of KBr0{sub 3} increased in both day experiments. Results from the higher doses of 50, 75, and 100 ppm were found to be significantly the same for the day 3 experiments while those of the day 5 higher doses are characterized by lack of clear cellular and nuclear outline such that scoring is difficult. Differences in MCN averages for the day 3 and 5 experiments appear to be insignificant. However, day 3 results show averages that are more significantly different from each other. These prove that the MCN can be used as an efficient and time-saving parameter for the allium test of chemicals with chromosome breaking capacities. (Author)

  6. Corynebacterium renale as a cause of reactions to the complement fixation test for Johne's disease

    NARCIS (Netherlands)

    Gilmour, N.J.L.; Goudswaard, J.

    Complement fixation (C.F.) tests and fluorescent antibody (F.A.) tests were carried out on sera from rabbits inoculated with Corynebacterium renale and Mycobacterium johnei, and on sera from cattle with C. renale pyelonephritis and with Johne's disease. Cross-reactions were a feature of the C.F.

  7. Evaluation of the repeated-dose liver and gastrointestinal tract micronucleus assays with 22 chemicals using young adult rats: summary of the collaborative study by the Collaborative Study Group for the Micronucleus Test (CSGMT)/The Japanese Environmental Mutagen Society (JEMS) - Mammalian Mutagenicity Study Group (MMS).

    Science.gov (United States)

    Hamada, Shuichi; Ohyama, Wakako; Takashima, Rie; Shimada, Keisuke; Matsumoto, Kazumi; Kawakami, Satoru; Uno, Fuyumi; Sui, Hajime; Shimada, Yasushi; Imamura, Tadashi; Matsumura, Shoji; Sanada, Hisakazu; Inoue, Kenji; Muto, Shigeharu; Ogawa, Izumi; Hayashi, Aya; Takayanagi, Tomomi; Ogiwara, Yosuke; Maeda, Akihisa; Okada, Emiko; Terashima, Yukari; Takasawa, Hironao; Narumi, Kazunori; Wako, Yumi; Kawasako, Kazufumi; Sano, Masaki; Ohashi, Nobuyuki; Morita, Takeshi; Kojima, Hajime; Honma, Masamitsu; Hayashi, Makoto

    2015-03-01

    The repeated-dose liver micronucleus (RDLMN) assay using young adult rats has the potential to detect hepatocarcinogens. We conducted a collaborative study to assess the performance of this assay and to evaluate the possibility of integrating it into general toxicological studies. Twenty-four testing laboratories belonging to the Mammalian Mutagenicity Study Group, a subgroup of the Japanese Environmental Mutagen Society, participated in this trial. Twenty-two model chemicals, including some hepatocarcinogens, were tested in 14- and/or 28-day RDLMN assays. As a result, 14 out of the 16 hepatocarcinogens were positive, including 9 genotoxic hepatocarcinogens, which were reported negative in the bone marrow/peripheral blood micronucleus (MN) assay by a single treatment. These outcomes show the high sensitivity of the RDLMN assay to hepatocarcinogens. Regarding the specificity, 4 out of the 6 non-liver targeted genotoxic carcinogens gave negative responses. This shows the high organ specificity of the RDLMN assay. In addition to the RDLMN assay, we simultaneously conducted gastrointestinal tract MN assays using 6 of the above carcinogens as an optional trial of the collaborative study. The MN assay using the glandular stomach, which is the first contact site of the test chemical when administered by oral gavage, was able to detect chromosomal aberrations with 3 test chemicals including a stomach-targeted carcinogen. The treatment regime was the 14- and/or 28-day repeated-dose, and the regime is sufficiently promising to incorporate these methods into repeated-dose toxicological studies. The outcomes of our collaborative study indicated that the new techniques to detect chromosomal aberrations in vivo in several tissues worked successfully. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  8. A large-scale radiometric micro-quantitative complement fixation test for serum antibody titration

    International Nuclear Information System (INIS)

    Bengali, Z.H.; Levine, P.H.; Das, S.R.

    1980-01-01

    A micro-quantitative complement fixation (CF) procedure based on 51 Cr release is described. The method employs 50% hemolysis as end point and the alternation equation to calculate the amount of complement involved in the hemolytic reaction. Compared to the conventional CF tests, the radiometric procedure described here is very precise and consistently reproducible. Also, since only 3 4-fold dilutions of sera are used for the titration of antibodies over a wide range of concentrations, the test is very concise and is economical to perform. Its format is amenable to automation and computerization. This radioimetric CF procedure is thus most useful for large-scale immunological research and epidemiological surveilance studies. (Auth.)

  9. Micronucleus frequency and content in healthy relatives of cancer patients

    Czech Academy of Sciences Publication Activity Database

    Zölzer, F.; Křížová, M.; Skalická, Z.F.; Rössnerová, Andrea; Šrám, Radim

    2017-01-01

    Roč. 22, č. 7 (2017), s. 667-673 ISSN 1354-750X Institutional support: RVO:68378041 Keywords : micronucleus centromere test * chromosomal damage * inheritable trait Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Human genetics Impact factor: 2.006, year: 2016

  10. What Can a Micronucleus Teach? Learning about Environmental Mutagenesis

    Science.gov (United States)

    Linde, Ana R.; Garcia-Vazquez, Eva

    2009-01-01

    The micronucleus test is widely employed in environmental health research. It can also be an excellent tool for learning important concepts in environmental health. In this article we present an inquiry-based laboratory exercise where students explore several theoretical and practical aspects of environmental mutagenesis employing the micronucleus…

  11. 2-Aminoanthracene, 5-fluorouracil, colchicine, benzo[a]pyrene, cadmium chloride and cytosine arabinoside tested in the in vitro mammalian cell micronucleus test (MNvit) in Chinese hamster ovary (CHO) cells at Covance Laboratories, Harrogate UK in support of OECD draft Test Guideline 487.

    Science.gov (United States)

    Whitwell, James; Fowler, Paul; Allars, Sarah; Jenner, Karen; Lloyd, Melvyn; Wood, Debbie; Smith, Katie; Young, Jamie; Jeffrey, Laura; Kirkland, David

    2010-10-29

    The reference genotoxic agents 2-aminoanthracene (a metabolism dependent weak clastogen), 5-fluorouracil (a nucleoside analogue, characterised by a steep dose response profile), colchicine (an aneugen that inhibits tubulin polymerisation), benzo[a]pyrene (a polycyclic aromatic hydrocarbon requiring metabolic activation), cadmium chloride (an inorganic carcinogen), and cytosine arabinoside (a nucleoside analogue that inhibits the gap-filling step of excision repair) were tested in the in vitro micronucleus assay using the Chinese hamster ovary (CHO) cell line at Covance Laboratories, Harrogate, UK. All chemicals were treated in the absence and presence of cytokinesis block (via addition of cytochalasin B) with this work forming part of a collaborative evaluation of the toxicity measures recommended in the draft OECD Test Guideline 487 on the In vitro Mammalian Cell Micronucleus Test (MNvit). The toxicity measures used, detecting a possible combination of both cytostasis and cell death (though not cell death directly), were relative population doubling, relative increase in cell counts and relative cell counts for treatments in the absence of cytokinesis block, and replication index in the presence of cytokinesis block. All of the chemicals tested either gave marked positive increases in the percentage of micronucleated cells with and without cytokinesis block, or did not induce micronuclei at concentrations giving approximately 50-60% toxicity (cytostasis and cell death) or less by all of the toxicity measures used. The outcome from this series of tests supports the use of relative increase in cell counts and relative population doubling, as well as relative cell counts, as appropriate measures of cytotoxicity for the non-cytokinesis blocked in vitro micronucleus assay. Copyright © 2010 Elsevier B.V. All rights reserved.

  12. CSF coccidioides complement fixation

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003526.htm CSF coccidioides complement fixation test To use the sharing features on this page, please enable JavaScript. CSF coccidioides complement fixation is a test that checks ...

  13. Micronucleus induction as a measure of I-131 exposure

    Energy Technology Data Exchange (ETDEWEB)

    Kasuba, V; Horvat, D [Inst. for Medical Recearch and Occupational Health, Zagreb (Croatia). Laboratory for Mutagenesis; Kusic, Z [Clinical Hospital Sestre Milosrdnice, Zagreb (Croatia). Dept. of Oncology and Nuclear Medicine; Vlatkovic, M [Clinical Hospital Centre, Zagreb (Croatia). Dept. of Nuclear Medicine and Radiation Protection

    1994-10-01

    The change of cell numbers in the peripheral blood following irradiation has been studied for many years, particularly in patients undergoing radiotherapy. Recently, attention is directed towards the use of cytogenetic-mutagenetic methods to estimate the biological effects of received radiation dose. The aim of our study was to identify the difference in number and distribution of micronucleus, depending of applied therapeutic dose of iodine-131. According to their diagnosis, six patients have received iodine-131 in range from 80 to 140 mCi, while in the other group of patients the dose values varied from 7 to 32 mCi. On in vitro peripheral blood lymphocyte cultures micronucleus test was applied. Micronucleus analyses were carried out before the treatment, 24, 48 and 96 hours after the oral application of radiopharmaceutical. The number of micronucleus is showing increase, depending on applied radioactivity of iodine-131 and duration of exposition. The clear dose response relationship was never found. These results illustrate the problem associated with the inhomogeneous distribution of dose which results from the concentration of incorporated radionuclide into thyroid or other tissues. (author).

  14. Comet assay and micronucleus tests on Oreochromis niloticus (Perciforme: Cichlidae) exposed to raw sugarcane vinasse and to phisicochemical treated vinasse by pH adjustment with lime (CaO).

    Science.gov (United States)

    Correia, Jorge E; Christofoletti, Cintya Ap; Ansoar-Rodríguez, Yadira; Guedes, Thays A; Fontanetti, Carmem S

    2017-04-01

    In Brazil vinasse, a main sugarcane distillery residue, stands out because every liter of alcohol generates 10-15 L of vinasse as waste. An alternative for the disposal of this waste is the fertirrigation of the sugarcane culture itself. However, the high amount released can saturate the soil and through leaching/percolation contaminate water resources. The aim of this study is verifying the toxic potential of vinasse in tilapias and effectiveness of the physicalchemical treatment of this waste with pH adjustment with lime (CaO). The comet assay and the micronucleus test were applied on animals exposed to dilutions of raw vinasse and vinasse adjusted to neutral pH. Bioassays with raw vinasse dilutions indicated a toxic and genotoxic potential; fish exposed to the highest concentration died less than 48 h after the exposure; the incidence of micronucleus was significantly higher when compared to negative control for all dilutions. For the comet assay, the scores of damage were statistically higher for all dilutions, with the exception of the 1% dillution. However, in the bioassay with the chemically treated vinasse (neutral pH), most fish in the 10% dilution survived and there was no significant difference when compared to the control. Damage scores in the comet assay were similar to the results of the untreated vinasse. The chemical treatment of vinasse with lime to neutralize the pH proved to be an effective alternative for the toxicity reduction of this residue, since it reduced the mortality of fish at higher concentrations and the incidence of damage to DNA. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. SEROLOGICAL DIAGNOSIS OF MODERN CHOLERA USING LIPOSOMAL ENTEROTOXIC DIAGNOSTICUM IN COMPLEMENT FIXATION TEST

    Directory of Open Access Journals (Sweden)

    I. V. Savelyeva

    2013-01-01

    Full Text Available Abstract. The possibility of serological diagnosis of cholera using cholera enterotoxic diagnostics kit in complement fixation test to detect anti-enterotoxic antibodies in sera of patients with cholera caused by hybrid variants of the El Tor biovar has been demonstrated. In patients with mild course of cholera anti-enterotoxic antibodies were detected in titres 1:50 and 1:200 in paired sera obtained on the 7th and 14th days of disease, respectively (fourfold titre increase. In patients with the course of medium severity 32-fold titre increase was recorded from the titre 1:100 in serum obtained on the fifth day of disease till the titre 1:3200 — on the twelfth day of disease. Antibodies titers reached 1:1600 and 1:800 were revealed in two medium course patients (adult and infant of 10 months on the sixth day of disease.

  16. Micronucleus frequency in exfoliated buccal cells from hairdresser who expose to hair products

    Directory of Open Access Journals (Sweden)

    Koh Hui Yee

    2015-06-01

    Full Text Available Background: Hairdresser is one of the fastest growing occupations in today’s society. Hairdresser help styling, cutting, colouring, perming, curling, straightening hair and various treatment to customer. Somehow, hairdresser are constantly exposed to chemical substances such as aromatic amines, hydrogen peroxide, thioglycolic acid, formaldehyde in hair products which can cause damage to human’s genome. Micronucleus is one of the effective biomarker for processes associated with the induction of DNA damage. Purpose: The aim of this study was to determine the micronucleus frequencies in buccal mucosa epithelial cells of hairdresser who were exposed to chemical of hair products. Method: This study was conducted on twenty female subjects, who were divided into 2 groups: exposed and non-exposed (control group. All subjects recruited were working in the same beauty salon. Buccal cells were obtained from each individual by using cytobrush. The cells were stained with modified Feulgen-Ronssenback method and counting of micronucleus per 1000 cell was done under light microscope. The data were analyzed using independent t-test and one-way Anova (p<0.05. Result: The result showed a significant difference in micronucleus frequency between 2 groups. There were a significantly increase of micronucleus frequency in hairdressers and increase of  micronucleus frequency with the longer duration of exposure. Conclusion: It concluded that the chemical substances of hair products had affected the micronucleus frequency ofthe epithelial cells in buccal mucosa of hairdressers.

  17. Wind-US Code Physical Modeling Improvements to Complement Hypersonic Testing and Evaluation

    Science.gov (United States)

    Georgiadis, Nicholas J.; Yoder, Dennis A.; Towne, Charles S.; Engblom, William A.; Bhagwandin, Vishal A.; Power, Greg D.; Lankford, Dennis W.; Nelson, Christopher C.

    2009-01-01

    This report gives an overview of physical modeling enhancements to the Wind-US flow solver which were made to improve the capabilities for simulation of hypersonic flows and the reliability of computations to complement hypersonic testing. The improvements include advanced turbulence models, a bypass transition model, a conjugate (or closely coupled to vehicle structure) conduction-convection heat transfer capability, and an upgraded high-speed combustion solver. A Mach 5 shock-wave boundary layer interaction problem is used to investigate the benefits of k- s and k-w based explicit algebraic stress turbulence models relative to linear two-equation models. The bypass transition model is validated using data from experiments for incompressible boundary layers and a Mach 7.9 cone flow. The conjugate heat transfer method is validated for a test case involving reacting H2-O2 rocket exhaust over cooled calorimeter panels. A dual-mode scramjet configuration is investigated using both a simplified 1-step kinetics mechanism and an 8-step mechanism. Additionally, variations in the turbulent Prandtl and Schmidt numbers are considered for this scramjet configuration.

  18. Micronucleus assay for radiation workers

    International Nuclear Information System (INIS)

    Balasem, A.N.; Ali, A.S.K.

    1997-01-01

    Micronucleus assay was performed on 49 radiation workers and 22 healthy volunteers. Radiation workers were subdivided into two groups according to their employments durations in the radiation field. Group a consisted of 18 radiation workers who have been in this work between 5 and 22 years. Group b included 31 employees who have been classified as radiation workers for 1 to 4.5 years. Statistical analysis showed significant variations between the yields of micronuclei in groups A and B as well as between group A and a group of healthy controls. Meanwhile no significant difference was noticed between the yields of micronuclei in group B and the corresponding values in the healthy controls. The possible effect of age in the induction of micronuclei was discussed and a comparison with the yield of chromosomal aberrations was described. It seems that cytokinesis- blocking method may be used to detect the radiation-induced micronuclei in workers exposed occupationally to ionizing radiation in levels below the maximum permissible limit of 0.05 Sv per year

  19. In vitro mutagenicity and genotoxicity study of 1,2-dichloroethylene, 1,1,2-trichloroethane, 1,3-dichloropropane, 1,2,3-trichloropropane and 1,1,3-trichloropropene, using the micronucleus test and the alkaline single cell gel electrophoresis technique (comet assay) in human lymphocytes.

    Science.gov (United States)

    Tafazoli, M; Kirsch-Volders, M

    1996-12-20

    The main objective of this study was to compare the cytotoxic genotoxic and mutagenic activity of a number of chlorinated aliphatic hydrocarbons, which are widely used as chemical intermediates, solvents, degreasing agents etc. in industry, and to establish the structure-toxicity relationship of the chemicals by using the most adequate determinants in estimating their toxicity. The mutagenicity and cytotoxicity of some of the candidate chemicals, namely 1,2-dichloroethylene, 1,1,2-trichloroethane, 1,3-dichloropropane, 1,2,3-trichloropropane and 1,1,3-trichloropropene were evaluated in an in vitro micronucleus assay. The cytokinesis-block methodology was applied on human lymphocytes in the presence or absence of an external metabolic activation system (S9-mix). In the micronucleus assay, all test substances, except 1,2,3-trichloropropane with and without S9-mix and 1,1,2-trichloroethane without S9-mix in the repeated experiment, exhibited a low but statistically significant mutagenic activity, compared to the concurrent control. However, none of the five chemicals was able to induce a clear and reproducible linear dose-dependent increase in micronucleus frequencies in this assay. Generally, mutagenic activity of the chemicals was found in the absence of severe cytotoxicity and/or cell cycle delay. The DNA breakage capacity and the cytotoxicity of these chemicals were also assessed in the alkaline single cell gel (SCG) electrophoresis test (comet assay) with and without S9-mix in isolated human lymphocytes. All chemical compounds induced DNA breakage, in the presence or absence of the metabolic activation system, at the doses tested. The data showed that the DNA reactivity of the chemicals increased with increasing degree of halogenation. The results of the present work suggested that the comet assay might be a more suitable and sensitive screening method than the micronucleus test for this particular class of compound. However, both assays do detect different

  20. Evaluation of the repeated-dose liver micronucleus assay using N-nitrosomorpholine in young adult rats: report on collaborative study by the Collaborative Study Group for the Micronucleus Test (CSGMT)/Japanese Environmental Mutagen Society (JEMS)-Mammalian Mutagenicity Study (MMS) Group.

    Science.gov (United States)

    Hayashi, Aya; Kosaka, Mizuki; Kimura, Aoi; Wako, Yumi; Kawasako, Kazufumi; Hamada, Shuichi

    2015-03-01

    The present study was conducted to evaluate the suitability of a repeated-dose liver micronucleus (LMN) assay in young adult rats as a collaborative study by the Mammalian mutagenicity study (MMS) group. All procedures were performed in accordance with the standard protocols of the MMS Group. Six-week-old male Crl:CD(SD) rats (5 animals/group) received oral doses of the hepatocarcinogen N-nitrosomorpholine (NMOR) at 0 (control), 5, 10, and 30mg/kg/day (10mL/kg) for 14 days. Control animals received vehicle (water). Hepatocytes were collected from the liver 24h after the last dose, and the number of micronucleated hepatocytes (MNHEPs) was determined by microscopy. The number of micronucleated immature erythrocytes (MNIMEs) in the femoral bone marrow was also determined. The liver was examined using histopathologic methods after formalin fixation. The results showed statistically significant and dose-dependent increases in the number of MNHEPs in the liver at doses of 10mg/kg and greater when compared with the vehicle control. However, no significant increase was noted in the number of MNIMEs in the bone marrow at doses of up to 30mg/kg. Histopathology of the liver revealed hypertrophy and single cell necrosis of hepatocytes at doses of 5mg/kg and above. These results showed that the induction of micronuclei by NMOR was detected by the repeated-dose LMN assay, but not by the repeated-dose bone marrow micronucleus assay. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Radiation dose-response relationship of micronucleus occurrence in pollen mother cells of tradescantia

    International Nuclear Information System (INIS)

    Kim, Jin Kyu; Kim, Yeon Ku; Song, Hi Sup

    1999-01-01

    This study was carried out to investigate the radiation dose-response of micronucleus frequencies in Tradescantia pollen mother cells. The number of micronuclei increased in the tetrads as a result of chromosome deletion after irradiation. The maximal frequency of micronucleus showed a good dose-response relationship in the range of dose 0∼50 cGy. On the basis of the relationship, a dose of 1 cGy resulted in two additional micronuclei in 100 tetrads. The radiation dose-response relationship of micronucleus occurrence is prerequisite to biological monitoring of radiation and can be modified for biological risk assessment of toxicants, and to safety test of water or soil integrity

  2. CAT SCRATCH DISEASE: RESULTS OF COMPLEMENT-FIXATION AND SKIN TESTS

    Science.gov (United States)

    Serologic and skin-testing data on a group of patients having cat scratch disease are presented to demonstrate a possible relationship to the psitt...indicate that the incidence of positive serologic reactions with the psitt-LGV group antigen is consistently higher in patients with cat scratch disease...patients, 2 of 5 did not respond with positive skin reactions when tested with cat scratch antigen, and at least 2 of the remaining 3 responded in a manner difficult to interpret.

  3. Using Modeling and Simulation to Complement Testing for Increased Understanding of Weapon Subassembly Response.

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Michael K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Davidson, Megan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-09-01

    As part of Sandia’s nuclear deterrence mission, the B61-12 Life Extension Program (LEP) aims to modernize the aging weapon system. Modernization requires requalification and Sandia is using high performance computing to perform advanced computational simulations to better understand, evaluate, and verify weapon system performance in conjunction with limited physical testing. The Nose Bomb Subassembly (NBSA) of the B61-12 is responsible for producing a fuzing signal upon ground impact. The fuzing signal is dependent upon electromechanical impact sensors producing valid electrical fuzing signals at impact. Computer generated models were used to assess the timing between the impact sensor’s response to the deceleration of impact and damage to major components and system subassemblies. The modeling and simulation team worked alongside the physical test team to design a large-scale reverse ballistic test to not only assess system performance, but to also validate their computational models. The reverse ballistic test conducted at Sandia’s sled test facility sent a rocket sled with a representative target into a stationary B61-12 (NBSA) to characterize the nose crush and functional response of NBSA components. Data obtained from data recorders and high-speed photometrics were integrated with previously generated computer models in order to refine and validate the model’s ability to reliably simulate real-world effects. Large-scale tests are impractical to conduct for every single impact scenario. By creating reliable computer models, we can perform simulations that identify trends and produce estimates of outcomes over the entire range of required impact conditions. Sandia’s HPCs enable geometric resolution that was unachievable before, allowing for more fidelity and detail, and creating simulations that can provide insight to support evaluation of requirements and performance margins. As computing resources continue to improve, researchers at Sandia are hoping

  4. Estudo fitoquímico e análise mutagênica das folhas e inflorescências de Erythrina mulungu (Mart. ex Benth. através do teste de micronúcleo em roedores Phytochemical and mutagenic analysis of leaves and inflorescences of Erythrina mulungu (Mart. Ex Benth through micronucleus test in rodents

    Directory of Open Access Journals (Sweden)

    A.P De Bona

    2012-01-01

    Full Text Available Este trabalho teve como objetivo investigar a composição química, estabelecer a dose letal média (DL50 e avaliar os potenciais efeitos mutagênicos do extrato hidroalcoólico de folhas e inflorescências de Erythrina mulungu Mart. ex Benth por meio do teste de micronúcleo em medula óssea de camundongos. Os ensaios fitoquímicos foram realizados através de reações preliminares com mudança de coloração e/ou formação de precipitado; a DL50, por meio da administração intraperitoneal de três concentrações dos extratos, avaliando-se o número de óbitos após 48 horas e o teste de micronúcleo foi feito por meio do método do esfregaço, após exposição dos animais a cinco dias de tratamento. Os resultados fitoquímicos demonstraram presença de açúcares redutores, fenóis e taninos, proteínas e aminoácidos, flavonóides, alcalóides, depsídeos e depsidonas e derivados de cumarina em ambos os órgãos; saponinas espumídicas e esteróides e triterpenóides nas folhas e glicosídeos cardiotônicos e antraquinônicos e alcalóides nas inflorescências. Para a DL50 a folha demonstrou-se atóxica e a inflorescência moderadamente tóxica. Para o teste de micronúcleo, os resultados indicaram ausência de citotoxicidade e genotoxicidade dose-dependente para as folhas e independente da dose para as inflorescências. Assim, esses resultados sugerem que a planta, nas condições analisadas, possui potencial para induzir danos ao DNA.This study aimed to investigate the chemical composition, to establish the mean lethal dose (LD50 and to assess the potential mutagenic effects of hydroalcoholic extract of leaves and inflorescences of Erythrina mulungu Mart. ex Benth by using micronucleus test in bone marrow of mice. Phytochemical assays were carried out through preliminary reactions with color change and/or precipitate formation; the LD50 was obtained by intraperitoneal administration of three concentrations of the extracts, assessing

  5. Absence of micronucleus formation in CHO-K1 cells cultivated in platelet lysate enriched medium.

    Science.gov (United States)

    Bernardi, Martina; Adami, Valentina; Albiero, Elena; Madeo, Domenico; Rodeghiero, Francesco; Astori, Giuseppe

    2014-03-01

    Human platelet lysate (PL) represents an effective substitute of fetal bovine serum (FBS) for mesenchymal stromal cell (MSC) cultivation. Compared to FBS, PL favors MSC proliferation significantly shortening the population doubling time and avoiding the risks related to the use of animal derivatives. Growth factors contained in the platelets are released upon platelet disruption following freezing/thawing cycles or as we have recently described by using ultrasound. We have investigated whether the increased cell proliferation achieved by using PL could induce mitotic stress and whether the potential formation of free radicals during PL production by ultrasound could cause chromosomal instability in mammalian cells. We have applied an image analysis assisted high content screening (HCS) in vitro micronucleus assay in the Chinese Hamster Ovarian K1 (CHO-K1) rodent mammalian cell line. PL was produced by sonication; for the micronucleus assay, CHO-K1 cells were exposed to increasing concentrations of PL. Cytokinesis was blocked by cytochalasin B, nuclei were stained with bisbenzimide and images were acquired and analyzed automatically using an HCS system, both with a 20× and a 10× objective. Our results suggest that growth stimulus induced by the use of PL did not significantly increase micronucleus formation in CHO-K1 cells compared to negative control. Micronucleus testing in conjunction with HCS could represent a valid tool to evaluate the safety of ancillary materials used in the production of cell-based medicinal products. Copyright © 2013 Elsevier GmbH. All rights reserved.

  6. CYTOKINESIS-BLOCK MICRONUCLEUS ASSAY IN HUMAN GLIOMA CELLS EXPOSED TO RADIATION

    Directory of Open Access Journals (Sweden)

    Jerzy Slowinski

    2011-05-01

    Full Text Available Biological tests are efficient in reflecting the biological influences of several types of generally harmful exposures. The micronucleus assay is widely used in genotoxicity studies or studies on genomic damage in general. We present methodological aspects of cytokinesis-block micronucleus assay performed in human gliomas irradiated in vitro. Eight human glioblastoma cell lines obtained from DSMZ (Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, Germany were gamma-irradiated (60Co over a dose range of 0-10 Gy. Cytokinesis-block micronucleus assay was performed to quantitate cytogenetic damage. The cells were fixed directly on dishes, stained with fluorochrome DAPI and evaluated under fluorescent and phase contrast microscope. The micronucleus frequency was expressed as a micronuclei (MN per binucleated cell (BNC ratio, calculated after scoring at least 100 BNC per dish. The frequency of spontaneous MN ranged from 0.17 to 0.613 (mean: 0.29 ± 0.14. After irradiation increase of MN frequency in the range of 0.312 - 2.241 (mean: 0.98 ± 0.68 was found at 10 Gy. Gliomas are extremely heterogenous in regard to cytogenetic effects of irradiation, as shown in this study by cytokinesis-block micronucleus assay. This test is easily performed on irradiated glioma cell lines and can assist in determining their radiosensitivity. However, in order to obtain reliable and reproducible results, precise criteria for MN scoring must be strictly followed. Simultaneous use of fluorescent and phase contrast equipment improves imaging of morphological details and can further optimize MN scoring.

  7. Cytological assay of micronucleus induction by radiation in oral cancer

    International Nuclear Information System (INIS)

    Bhattathiri, V.N.; Bindu, L.; Remani, P.; Chandralekha, B.; Davis, C.A.; Krishnan Nair, M.

    1996-01-01

    A study was conducted to analyze the dose-response relationship of micronucleus (MN) induction by radiation in eighty-three patients with oral cancers. Serial scrape smears were taken before treatment and after delivery of various fractions of a course of radical radiotherapy. The smears were stained with Giemsa's stain and frequency of micronucleated cells (MNC) evaluated. Before treatment 70.5% of tumours showed MNC, the mean value being 4.18 MNC/1000 cells. The frequency of MNC, increased with increasing dose of radiation. As regards relation to treatment duration, there was initially a slight increase, followed by rapid increase and then a plateauing. Radiosensitive and resistant tumours showed differing pattern of change. The MN test by serial cytological assay has potential as a tool to understand the dynamics of radiation induced cell death and predict radiosensitivity. (author). 4 refs., 5 figs

  8. Open-book tests to complement assessment-programmes : Analysis of open and closed-book tests

    NARCIS (Netherlands)

    Heijne-Penninga, M.; Kuks, J. B. M.; Schonrock-Adema, J.; Snijders, T. A. B.; Cohen-Schotanus, J.

    Today's health sciences educational programmes have to deal with a growing and changing amount of knowledge. It is becoming increasingly important for students to be able to use and manage knowledge. We suggest incorporating open-book tests in assessment programmes to meet these changes. This view

  9. Radiosensitiviness of blood lymphocytes from skin cancer patients and healthy volunteers as determined by micronucleus assay

    International Nuclear Information System (INIS)

    Lohmann, Tania Helena Ochi.

    1995-01-01

    Cancer, a major death cause in developed countries, has been related to somatic mutations that could be detected by cytogenetic analysis. Among the tools used in these tests, the micronucleus assay has been largely applied at population surveillance, biological dosimetry and early detection of groups with higher risks to developing cancers. In this study, we analysed the chromosome susceptibility of blood lymphocytes from basocellular skin cancer patients and healthy volunteers. The cytogenetic analysis was performed by a micronucleus assay, using progressive doses of ionizing radiation from a 60 Co source as mutagen. Briefly, the blood lymphocytes were irradiated in vitro, as processed by the cytokinesis-blocked method. The micronucleus frequency and distribution, cell cycle kinetics, nucleation index and dose-response relationship were determined in each patient. The results showed that the basocellular skin cancer patients lymphocytes presented higher spontaneous micronucleus frequency as compared with those from healthy young volunteers but lower than healthy now young volunteers . The radiation-induced micronucleus analysis showed that the basocellular skin cancer patients' lymphocytes presented similar proportion of damage lymphocytes as compared with those from healthy volunteers. Nevertheless, the magnitude of this damage was higher in this group with doses. Higher than 400 c Gy, which was not occurred in healthy volunteers. Cell cycle kinetics, as determined by the nucleation index, was lower in basocellular skin cancer patients as compared with healthy volunteers, indicating a more slow cell cycle. Our data showed that the lymphocytes from carcinoma basocellular patients were more radiosensitive as compared with those form healthy volunteers. (author). 159 refs., 21 figs., 16 tabs

  10. Test of micronucleus in lymphocytes with the cytokinesis-block like possible indicator of the answer of the patient to the radiotherapy; Ensayo de micronucleos en linfocitos con bloqueo de la citocinesis como posible indicador de la respuesta del paciente a la radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Giorgio, Marina di; Nasazzi, Nora; Taja, Maria R. [Autoridad Regulatoria Nuclear, Buenos Aires (Argentina); Roth, Berta [Instituto de Oncologia Angel H. Roffo, Buenos Aires (Argentina); Sardi, Mabel; Menendez, Pablo R. [Hospital Italiano, Buenos Aires (Argentina)

    2001-07-01

    In order to evaluate the individual cytogenetic response to radiotherapy and its comparison with the clinical response, the cytokinesis-block micronucleus assay was applied to peripheral blood lymphocytes of patients with cervix cancer undergoing radiotherapy. The cytogenetic data were analysed using a mathematical model to evaluate the attenuation of the cytogenetic effect as a function of the time between a single exposure and blood sampling, estimating a cytogenetic recovery factor (k) that might correlate with the individual radiosensitivity, contributing with radiosensitivity tests of current use but applying a rapid methodology easy to implement in a routine clinical laboratory. Long term clinical observations could confirm the validity of k in expressing predisposition of the subject to develop delayed effects. (author)

  11. In situ biomonitoring of the genotoxic effects of mixed industrial emissions using the Tradescantia micronucleus and pollen abortion tests with wild life plants: Demonstration of the efficacy of emission controls in an eastern European city

    Energy Technology Data Exchange (ETDEWEB)

    Misik, Miroslav [Department of Botany, Comenius University in Bratislava, Faculty of Natural Sciences, Revova 39, SK 811 02 Bratislava 1 (Slovakia); Micieta, Karol [Department of Botany, Comenius University in Bratislava, Faculty of Natural Sciences, Revova 39, SK 811 02 Bratislava 1 (Slovakia); Solenska, Martina [Department of Botany, Comenius University in Bratislava, Faculty of Natural Sciences, Revova 39, SK 811 02 Bratislava 1 (Slovakia); Misikova, Katarina [Department of Botany, Comenius University in Bratislava, Faculty of Natural Sciences, Revova 39, SK 811 02 Bratislava 1 (Slovakia); Pisarcikova, Helena [Department of Botany, Comenius University in Bratislava, Faculty of Natural Sciences, Revova 39, SK 811 02 Bratislava 1 (Slovakia); Knasmueller, Siegfried [Institute of Cancer Research, Department of Inner Medicine I, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna (Austria)]. E-mail: siegfried.knasmueller@meduniwien.ac.at

    2007-01-15

    Aim of the study was to monitor changes of genotoxic activity of urban air caused by an incinerator and a petrochemical plant in Tradescantia micronucleus (Trad-MCN) and pollen fertility assays with wild plants (Chelidonium majus, Clematis vitalba, Cichorium intybus, Linaria vulgaris, Robinia pseudoacacia). While in the first sampling period (1997-2000) significantly (on average 80%) more MN were found at the polluted site in comparison to controls from a rural area, no significant effects were observed during a later period (between 2003 and 2005). A similar pattern was observed in the pollen abortion assays in which the most pronounced effects were found in chicory and false acacia. The differences of the results obtained in the two periods can be explained by a substantial reduction of air pollution by use of new technologies. In particular the decrease of SO{sub 2} emissions may account for the effects seen in the present study. - Air pollution caused by industrial emissions induced micronuclei in Tradescantia and increased pollen abortion in wild plant species.

  12. Development of an HIV Testing Dashboard to Complement the HIV Care Continuum Among MSM, PWID, and Heterosexuals in Washington, DC, 2007-2015.

    Science.gov (United States)

    Patrick, Rudy; Greenberg, Alan; Magnus, Manya; Opoku, Jenevieve; Kharfen, Michael; Kuo, Irene

    2017-07-01

    We developed an HIV testing dashboard to complement the HIV care continuum in selected high-risk populations. Using National HIV Behavioral Surveillance (NHBS) data, we examined trends in HIV testing and care for men who have sex with men (MSM), persons who inject drugs (PWID), and heterosexuals at elevated risk (HET). Between 2007 and 2015, 4792 participants ≥18 years old completed a behavioral survey and were offered HIV testing. For the testing dashboard, proportions ever tested, tested in the past year, testing HIV-positive, and newly testing positive were calculated. An abbreviated care continuum for self-reported positive (SRP) persons included ever engagement in care, past year care, and current antiretroviral (ARV) use. The testing dashboard and care continuum were calculated separately for each population. Chi-square test for trend was used to assess significant trends over time. Among MSM, lifetime HIV testing and prevalence significantly increased from 96% to 98% (P = 0.01) and 14%-20% (P = 0.02) over time; prevalence was highest among black MSM at all time points. HIV prevalence among female persons who inject drugs was significantly higher in 2015 vs. 2009 (27% and 13%; P dashboard can be used to complement the HIV care continuum to display improvements and disparities in HIV testing and care over time.

  13. [Influence of Four Kinds of PPCPs on Micronucleus Rate of the Root-Tip Cells of Vicia-faba and Garlic].

    Science.gov (United States)

    Wang, Lan-jun; Wang, Jin-hua; Zhu, Lu-sheng; Wang, Jun; Zhao, Xiang

    2016-04-15

    In order to determine the degree of biological genetic injury induced by PPCPs, the genotoxic effects of the doxycycline (DOX), ciprofloxacin (CIP), triclocarban (TCC) and carbamazepine (CBZ) in the concentration range of 12.5-100 mg · L⁻¹ were studied using micronucleus rate and micronucleus index of Vicia-fabe and garlic. The results showed that: (1) When the Vicia-faba root- tip cells were exposed to DOX, CIP, TCC and CBZ, micronucleus rates were higher than 1.67 ‰ (CK₁), it was significantly different from that of the control group (P garlic root tip cells were exposed to DOX, CIP, TCC and CBZ respectively, the micronucleus rates were less than those of the Vicia-faba, while in most treatments significantly higher than that of the control group (0.67‰). The micronucleus index was higher than 3.5 in the groups exposed to CIP with concentrations of 25, 50, 100 mg · L⁻¹ and TCC and CBZ with concentrations of 25 mg · L⁻¹; With the increase of exposure concentrations, the micronucleus rate showed a trend of first increasing and then decreasing as well. (3) Under the same experimental conditions, the cells micronucleus rates of the garlic cells caused by the four tested compounds were significantly lower than those of Vicia-faba. (4) The micronucleus index of the root tip cells of Vicia-faba and garlic treated with the four kinds of compounds followed the order of CIP > CBZ > TCC > DOX. These results demonstrated that the four compounds caused biological genetic injury to root-tip cells of Vicia-faba and garlic, and the genetic damage caused to garlic was significantly lower than that to Vicia-faba. The damages caused by the four kinds of different compounds were also different.

  14. Assessment of the genotoxicity of 137Cs radiation using Vicia-micronucleus, Tradescantia-micronucleus and Tradescantia-stamen-hair mutation bioassays.

    Science.gov (United States)

    Minouflet, Marion; Ayrault, Sophie; Badot, Pierre-Marie; Cotelle, Sylvie; Ferard, Jean-François

    2005-01-01

    Since the middle of the 20th century, ionizing radiations from radioactive isotopes including 137Cs have been investigated to determine their genotoxic impact on living organisms. The present study was designed to compare the effectiveness of three plant bioassays to assess DNA damage induced by low doses of 137Cs: Vicia-micronucleus test (Vicia-MCN), Tradescantia-micronucleus test (Trad-MCN) and Tradescantia-stamen-hair mutation test (Trad-SH) were used. Vicia faba (broad bean) and Tradescantia clone 4430 (spiderwort) were exposed to 137Cs according to different scenarios: external and internal (contamination) irradiations. Experiments were conducted with various levels of radioactivity in solution or in soil, using solid or liquid 137Cs sources. The three bioassays showed different sensitivities to the treatments. Trad-MCN appeared to be the most sensitive test (significative response from 1.5 kBq/200 ml after 30 h of contamination). Moreover, at comparable doses, internal irradiations led to larger effects for the three bioassays. These bioassays are effective tests for assessing the genotoxic effects of radioactive 137Cs pollution.

  15. Assessment of the genotoxicity of 137Cs radiation using Vicia-micronucleus, Tradescantia-micronucleus and Tradescantia-stamen-hair mutation bioassays

    International Nuclear Information System (INIS)

    Minouflet, Marion; Ayrault, Sophie; Badot, Pierre-Marie; Cotelle, Sylvie; Ferard, Jean-Francois

    2005-01-01

    Since the middle of the 20th century, ionizing radiations from radioactive isotopes including 137 Cs have been investigated to determine their genotoxic impact on living organisms. The present study was designed to compare the effectiveness of three plant bioassays to assess DNA damage induced by low doses of 137 Cs: Vicia-micronucleus test (Vicia-MCN), Tradescantia-micronucleus test (Trad-MCN) and Tradescantia-stamen-hair mutation test (Trad-SH) were used. Vicia faba (broad bean) and Tradescantia clone 4430 (spiderwort) were exposed to 137 Cs according to different scenarios: external and internal (contamination) irradiations. Experiments were conducted with various levels of radioactivity in solution or in soil, using solid or liquid 137 Cs sources. The three bioassays showed different sensitivities to the treatments. Trad-MCN appeared to be the most sensitive test (significative response from 1.5 kBq/200 ml after 30 h of contamination). Moreover, at comparable doses, internal irradiations led to larger effects for the three bioassays. These bioassays are effective tests for assessing the genotoxic effects of radioactive 137 Cs pollution

  16. Health assessment of gasoline and fuel oxygenate vapors: micronucleus and sister chromatid exchange evaluations.

    Science.gov (United States)

    Schreiner, Ceinwen A; Hoffman, Gary M; Gudi, Ramadevi; Clark, Charles R

    2014-11-01

    Micronucleus and sister chromatid exchange (SCE) tests were performed for vapor condensate of baseline gasoline (BGVC), or gasoline with oxygenates, methyl tert-butyl ether (G/MTBE), ethyl tert butyl ether (G/ETBE), t-amyl methyl ether (G/TAME), diisopropyl ether (G/DIPE), t-butyl alcohol (TBA), or ethanol (G/EtOH). Sprague Dawley rats (the same 5/sex/group for both endpoints) were exposed to 0, 2000, 10,000, or 20,000mg/m(3) of each condensate, 6h/day, 5days/week over 4weeks. Positive controls (5/sex/test) were given cyclophosphamide IP, 24h prior to sacrifice at 5mg/kg (SCE test) and 40mg/kg (micronucleus test). Blood was collected from the abdominal aorta for the SCE test and femurs removed for the micronucleus test. Blood cell cultures were treated with 5μg/ml bromodeoxyuridine (BrdU) for SCE evaluation. No significant increases in micronucleated immature erythrocytes were observed for any test material. Statistically significant increases in SCE were observed in rats given BGVC alone or in female rats given G/MTBE. G/TAME induced increased SCE in both sexes at the highest dose only. Although DNA perturbation was observed for several samples, DNA damage was not expressed as increased micronuclei in bone marrow cells. Inclusion of oxygenates in gasoline did not increase the effects of gasoline alone or produce a cytogenetic hazard. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Dependence of the bystander effect for micronucleus formation on dose of heavy-ion radiation in normal human fibroblasts

    International Nuclear Information System (INIS)

    Matsumoto, Yoshitaka; Hamada, Nobuyuki; Aoki-Nakano, Mizuho; Furusawa, Yoshiya; Funayama, Tomoo; Sakashita, Tetsuya; Kobayashi, Yasuhiko; Wada, Seiichi; Kakizaki, Takehiko

    2015-01-01

    Ionising radiation-induced bystander effects are well recognised, but its dependence on dose or linear energy transfer (LET) is still a matter of debate. To test this, 49 sites in confluent cultures of AG01522D normal human fibroblasts were targeted with microbeams of carbon (103 keV μm -1 ), neon (375 keV μm -1 ) and argon ions (1260 keV μm -1 ) and evaluated for the bystander-induced formation of micronucleus that is a kind of a chromosome aberration. Targeted exposure to neon and argon ions significantly increased the micronucleus frequency in bystander cells to the similar extent irrespective of the particle numbers per site of 1- 6. In contrast, the bystander micronucleus frequency increased with increasing the number of carbon-ion particles in a range between 1 and 3 particles per site and was similar in a range between 3 and 8 particles per site. These results suggest that the bystander effect of heavy ions for micronucleus formation depends on dose. (authors)

  18. Improving a Complement-fixation Test for Equine Herpesvirus Type-1 by Pretreating Sera with Potassium Periodate to Reduce Non-specific Hemolysis

    Science.gov (United States)

    BANNAI, Hiroshi; NEMOTO, Manabu; TSUJIMURA, Koji; YAMANAKA, Takashi; KONDO, Takashi; MATSUMURA, Tomio

    2013-01-01

    Non-specific hemolysis has often been observed during complement-fixation (CF) tests for equine herpesvirus type-1 (EHV-1), even when the sera have virus-specific CF antibodies. This phenomenon has also been reported in CF tests for various infectious diseases of swine. We found that the sera from 22 of 85 field horses (25.9%) showed non-specific hemolysis during conventional CF testing for EHV-1. Because pretreatment of swine sera with potassium periodate (KIO4) improves the CF test for swine influenza, we applied this method to horse sera. As we expected, horse sera treated with KIO4 did not show non-specific hemolysis in the EHV-1 CF test, and precise determination of titers was achieved. PMID:24834005

  19. Monitoramento da ação genotóxica em trabalhadores de sapatarias através do teste de micronúcleos, Pelotas, Rio Grande do Sul Monitoring the genotoxic action in shoe workers by micronucleus test, Pelotas, Rio Grande do Sul State

    Directory of Open Access Journals (Sweden)

    Natália Silveira Corrêa

    2009-12-01

    Full Text Available Neste trabalho, investigou-se a frequência de micronúcleos em células esfoliadas da mucosa bucal de trabalhadores de sapatarias, na cidade de Pelotas (RS. O estudo constou de 54 trabalhadores de sapatarias expostos à cola e solventes e 54 controles. Avaliou-se a incidência de células com micronúcleos(CMN, binucleadas(CBN, núcleos ligados(CNL e total de anomalias(TA, em 2.000 células por indivíduo. Elaborou-se um banco de dados no programa SPSS "for Windows" pelo teste de Mann-Whitney U, pIn this paper it was investigated the micronuclei frequency in exfoliated oral mucosa cells in shoe shop workers in the city of Pelotas, RS. The study counted on 54 shoe workers exposed to glue and solvents and 54 controls. It was evaluated the incidence of cells with micronucleus (CMN, bi-nucleus (CBN, linked nucleus (CLN and total amount of anomalies (TAA, in 2000 cells per person. A database was created in the SPSS "for Windows" software using the Mann-Whitney U, p<0.05 test. The average of anomalies among shoe workers was 8.69±6.49CMN; 8.85±4.92CBN; 5.78±4.78CNL; 23.31±10.01TA, in the controlled 4.00±5.05CMN; 4.63±4.35CBN; 4.76±5.00CNL; 13.39±9.43TA (p=0.0001; p=0.0001; p=0.144 and p=0.0001 respectively. It was also evaluated the age, gender, time of work, family income, smoke, alcohol beverages, the influence of dermatological, ophthalmological, respiratory and central nervous system (CNS diseases in the number of cell anomalies. These items did not have any influence. It was only observed that among the age group of 15 to 29 years old the number of CNL was bigger than among the age group of 45 to 72. Among those with time of work of 0.1 and 10 years presented a higher CNM than in the other group range.

  20. The role of the micronucleus in stomatogenesis in sexual reproduction of Paramecium tetraurelia: laser microbeam irradiation of the micronucleus

    International Nuclear Information System (INIS)

    Tam Laiwa; Ng, S.F.

    1986-01-01

    Fifteen amicronucleate cell lines and 22 cell lines with defective micronuclei were obtained following selective laser microbeam irradiation of the micronucleus. The amicronucleate cell lines showed reduced growth rate and formed abnormal oral apparatuses in asexual reproduction, and failed to produce any oral apparatus in autogamy. The 22 cell lines with defective micronucleus exhibited various abnormalities of the oral apparatus newly formed during autogamy. These abnormalities included the arrest of membranelle assembly, reduction in the length of the buccal cavity and oral membranelles, disruption of the organization of the membranelles, quadrulation of the dorsal peniculus, and failure of addition of membranellar basal body rows. Hence the micronucleus plays multiple roles in sexual stomatogenesis. Our results agree with the notion that the micronucleus acts during a critical period between the second meiotic division and up to the formation of the zygotic nucleus to control the early stage of oral membranelle assembly. Laser microbeam irradiation might have created recessive mutations and/or chromosomal aberrations, which were expressed during this critical period with the formation of abnormal postmeiotic nuclei. (author)

  1. Role of the micronucleus in stomatogenesis in sexual reproduction of Paramecium tetraurelia: laser microbeam irradiation of the micronucleus

    Energy Technology Data Exchange (ETDEWEB)

    Tam Laiwa; Ng, S.F.

    1986-12-01

    Fifteen amicronucleate cell lines and 22 cell lines with defective micronuclei were obtained following selective laser microbeam irradiation of the micronucleus. The amicronucleate cell lines showed reduced growth rate and formed abnormal oral apparatuses in asexual reproduction, and failed to produce any oral apparatus in autogamy. The 22 cell lines with defective micronucleus exhibited various abnormalities of the oral apparatus newly formed during autogamy. These abnormalities included the arrest of membranelle assembly, reduction in the length of the buccal cavity and oral membranelles, disruption of the organization of the membranelles, quadrulation of the dorsal peniculus, and failure of addition of membranellar basal body rows. Hence the micronucleus plays multiple roles in sexual stomatogenesis. Our results agree with the notion that the micronucleus acts during a critical period between the second meiotic division and up to the formation of the zygotic nucleus to control the early stage of oral membranelle assembly. Laser microbeam irradiation might have created recessive mutations and/or chromosomal aberrations, which were expressed during this critical period with the formation of abnormal postmeiotic nuclei.

  2. Antibodies against glucan, chitin, and Saccharomyces cerevisiae mannan as new biomarkers of Candida albicans infection that complement tests based on C. albicans mannan.

    Science.gov (United States)

    Sendid, B; Dotan, N; Nseir, S; Savaux, C; Vandewalle, P; Standaert, A; Zerimech, F; Guery, B P; Dukler, A; Colombel, J F; Poulain, D

    2008-12-01

    Antibodies against Saccharomyces cerevisiae mannan (ASCA) and antibodies against synthetic disaccharide fragments of glucans (ALCA) and chitin (ACCA) are biomarkers of Crohn's disease (CD). We previously showed that Candida albicans infection generates ASCA. Here, we explored ALCA and ACCA as possible biomarkers of invasive C. albicans infection (ICI). ASCA, ALCA, ACCA, and Candida mannan antigen and antibody detection tests were performed on 69 sera obtained sequentially from 18 patients with ICIs proven by blood culture, 59 sera from CD patients, 47 sera from hospitalized subjects colonized by Candida species (CZ), and 131 sera from healthy controls (HC). ASCA, ALCA, and ACCA levels in CD and ICI patients were significantly different from those in CZ and HC subjects (PACCA, and Platelia Candida tests, 100% of ICIs were detected, with the kinetics of the antibody response depending on the patient during the time course of infection. A large number of sera presented with more than three positive tests. This is the first evidence that the detection of antibodies against chitin and glucans has diagnostic value in fungal infections and that these tests can complement more specific tests. Future trials are necessary to assess the value of these tests in multiparametric analysis, as well as their pathophysiological relevance.

  3. Micronucleus formation in cultured human keratinocytes: Involvement of intercellular bioactivation.

    Science.gov (United States)

    van Pelt, F N; Haring, R M; Weterings, P J

    1991-01-01

    Micronucleus formation in cultured human keratinocytes was studied after exposure to benzo[a]pyrene, cyclophosphamide and 12-O-tetradecanoylphorbol-13-acetate without the addition of an exogenous metabolizing system. The first two agents need bioactivation by specific isoenzymes of cytochrome P-450 to form genotoxic intermediates. Benzo[a]pyrene induced the micronucleus formation in both uninduced and Aroclor 1254-pretreated cultures. Clastogenic effects of cyclophosphamide were observed only in Aroclor 1254-pretreated cells. The tumour promotor 12-O-tetradecanoylphorbol-13-acetate did not affect the frequency of micronuclei in human keratinocytes. The data indicate that cultured human keratinocytes can be used to study the tissue-specific response to genotoxic agents as well as interindividual variation in biotransformation capacity.

  4. Micronucleus assay as a biomarker of genotoxicity in the occupational exposure to agrochemicals in rural workers.

    Science.gov (United States)

    Gentile, N; Mañas, F; Bosch, B; Peralta, L; Gorla, N; Aiassa, D

    2012-06-01

    This paper aims to evaluate the genotoxic effect of agrochemicals in rural workers occupationally exposed by the micronucleus assay in peripheral blood lymphocytes and to promote the development of health and environmental preventive and protective practices. A total of 30 blood samples from 20 individuals occupationally exposed to different agrochemicals and 10 unexposed persons, who formed the reference group, were analyzed. We found statistically significant differences (p < 0.0005, Student's t Test) in the frequency of micronuclei between the two groups (7.20 ± 1.55 and 15.15 ± 5.10 CBMN for reference and exposed groups respectively). The analysis of age showed a positive correlation (Pearson Correlation Test) with the frequency of micronuclei in exposed population (p < 0.05; r(2) = 0.47), in contrast with smoking habits and years of exposure. Micronucleus assay allows an early detection of populations at higher risk of having genetic damage, allowing us to implement strategies of intervention for the purpose of contributing to reduce that risk.

  5. Cytokinesis-block micronucleus method in micro-blood cultures

    International Nuclear Information System (INIS)

    Liu Jinwen; Wang Lianzhi; Yang Cangzhen; Yao Yanyu

    1991-01-01

    This paper reports the cytokinesis-block micronucleus method in micro-blood cultures. The observations on detection induced micronuclei of different doses of 60 Co γ-rays irradiation and spontaneous micronucleus of different ages were performed with CB method in comporison with conventional micronucleus (CM) method. The results showed that with direct peripheral micro-blood cultures the cytoknesis-block micronuclei is also obtained. Using CB method, the micronuclei fequency of different ages was linear relationship, Y = 1.62 + 0.74 D, the spontaneous micronuclei frequency of different ages was 4.14%, the induced micronuclei also was a linear relationship, Y = 6.01 + 0.692 D. Using CM method, it showed that the induced micronuclei was a linear relationship, Y = 0.486 D - 1.968, but there is no significant difference between the micronuclei frequency of different ages. Comparison with CM and direct blood smear methods confirmed that the cytokinesis-block method of micro-blood cultures is more sensitive and precise

  6. Hyperthermia-induced micronucleus formation in a human keratinocyte cell line

    International Nuclear Information System (INIS)

    Hintzsche, Henning; Riese, Thorsten; Stopper, Helga

    2012-01-01

    Elevated temperature can cause biological effects in vitro and in vivo. Many studies on effects of hypo- and hyperthermia have been conducted, but only few studies systematically investigated the formation of genomic damage in the micronucleus test in human cells in vitro as a consequence of different temperatures. In the present study, HaCaT human keratinocytes were exposed to different temperatures from 37 °C to 42 °C for 24 h in a regular cell culture incubator. Micronucleus frequency as a marker of genomic damage was elevated in a temperature-dependent and statistically significant manner. Apoptosis occurred at temperatures of 39 °C or higher. Cell proliferation was unaffected up to 40 °C and decreased at 41 °C and 42 °C. Expression of the heat shock protein Hsp70 was elevated, particularly at temperatures of 40 °C and higher. These findings are in agreement with several in vivo studies and some in vitro studies looking at single, specific temperatures, but a systematically investigated temperature-dependent increase of genomic damage in human keratinocytes in vitro is demonstrated for the first time here.

  7. Longitudinal study of the indirect immunofluorescence and complement fixation tests for diagnosis of chagas' disease in immunosuppressed patients submitted to renal transplantation

    Directory of Open Access Journals (Sweden)

    José Fernando de Castro Figueiredo

    1993-12-01

    Full Text Available Clinical and serological follow-up of 7 patients submitted to renal transplantation and presenting positive serological reactions to Chagas 'disease before immunossupression did not show significant changes in indirect immunofluorescence and complement fixation titres for Chagas ' disease, or signs and symptoms indicating exacerbation of the disease during follow- up. In addition, 18 of 66 recipients of renal transplants considered to be non-chagasic before immunosuppression showed at least one positive result to the indirect immunofluorescence test for Chagas ' disease during the study period. The results suggest that the immunosuppression State induced in chagasic patients submitted to renal transplant did notpromoted exacerbation of the chronic infection in these patients and not interfere with the serological response of chronic chagasics, thus permitting the use of these serologic reactions for diagnostic purposes in these cases. However, the positive results ofthe indirect immunofluorescence test in non- chagasic patients indicate the needforjudicious interpretation ofthe indirect immunofluorescence test for the diagnosis of Chagas' disease in renal transplanted patients.

  8. Parallel Recovery in a Trilingual Speaker: The Use of the Bilingual Aphasia Test as a Diagnostic Complement to the Comprehensive Aphasia Test

    Science.gov (United States)

    Green, David W.; Ruffle, Louise; Grogan, Alice; Ali, Nilufa; Ramsden, Sue; Schofield, Tom; Leff, Alex P.; Crinion, Jenny; Price, Cathy J.

    2011-01-01

    We illustrate the value of the Bilingual Aphasia Test in the diagnostic assessment of a trilingual speaker post-stroke living in England for whom English was a non-native language. The Comprehensive Aphasia Test is routinely used to assess patients in English, but only in combination with the Bilingual Aphasia Test is it possible and practical to…

  9. 40 CFR 799.9539 - TSCA mammalian erythrocyte micronucleus test.

    Science.gov (United States)

    2010-07-01

    ... sampling time, unless acceptable inter-animal variability and frequencies of cells with micronuclei are...., Wehr, C.M., and Langlois, R.G. A Simple Fluorescent Staining Procedure for Micronuclei and RNA in...

  10. Micronucleus test in fish genome: A sensitive monitor for aquatic ...

    African Journals Online (AJOL)

    The aquatic environment makes up the major part of our environment and resources, therefore its safety is directly related to the safety our health. In this study, three tilapia species (Oreochromis niloticus, Oreochromis aureus and Tilapia zilli) and Clarias gariepinus were employed to estimate water pollution using ...

  11. Micronucleus test in mice fed on irradiated whole diet

    International Nuclear Information System (INIS)

    Reddy, P.P.; Reddi, O.S.; Pentiah, P.R.; Rani, M.V.U.; Devi, K.R.; Goud, S.N.

    1981-01-01

    Eight week old Swiss albino male mice were fed on freshly irradiated or unirradiated whole diet for one week. (Exposure was to 75 or 200 kR γ rays from a 1000 Ci 60 Co γ source at a dose rate of 584 R/min.) On the seventh day, six hours after feeding, the mice were killed and bone marrow preparations were made by the Schmid technique. From each group three animals were taken and from each animal 2000 polychromatic and normochromatic erythrocytes were scored. It was evident from the data obtained that the irradiated whole diet failed to induce any significant increase in the incidence of micronuclei in polychromatic erythrocytes. Similarly, there was no significant increase in the frequency of micronuclei in normochromatic erythrocytes when compared with control data. The polychromatic to normochromatic ratio was also unaffected. The diet consisted of wheat flour (60%). groundnut cake (20%), fish meal (8%), Bengal gram flour (8%), dried yeast (3%), salt/mineral mixture (1%) and traces of vitamins. (U.K.)

  12. Low dose effects detected by micronucleus assay in lymphocytes

    International Nuclear Information System (INIS)

    Koeteles, G.J.; Bojtor, I.; Kubasova, T.; Horvath, G.

    1997-01-01

    The effects of low doses of X-rays between 0.01 and 1 Gy were studied on whole blood samples of various individuals using the cytokinesis-blocked lymphocyte micronucleus assay as an endpoint. The adaptive response could be induced in G 0 cells by 0.01 Gy followed by 1 Gy challenging dose within a time period of 8 hours, in vitro. The probability distribution of micronucleus increments in those samples which had received very low doses in the range 0.01-0.05 Gy proved to be of asymmetrical type (i.e. lognormal) -very likely to the same shape which has been verified for unirradiated (control) population - while the variable turned to be normally distributed at or above 1 Gy. Profound changes have been experienced in the main characteristics of the linear dose - response relationship and in regression parameters, as well, when successively lessened dose ranges were studied toward 0.01 Gy. In the range below ∼ 0.2 Gy the response were found to be unrelated to the absorbed dose. These findings suggest that in (very) low dose range a higher attention should be needed to biological parameters like repair, protective mechanisms and antioxidant capacities, rather than to the absorbed radiation energy only. (author)

  13. Micronucleus as biomarkers of cancer risk in anabolic androgenic steroids users.

    Science.gov (United States)

    Souza, L da Cunha Menezes; da Cruz, L A; Cerqueira, E de Moraes Marcílio; Meireles, Jrc

    2017-03-01

    The use of anabolic androgenic steroids (AAS) has grown among practitioners of recreational bodybuilding, with significant contributions of designer steroids, aiming muscle hypertrophy in healthy subjects. The abusive use of AAS in general is associated with adverse effects; one of the most worrisome is cancer development. The aim of this study was to evaluate the effectiveness of the cytokinesis block micronucleus (CBMN) test in human lymphocytes in identifying risk groups for cancer development in users of AAS. Blood was collected from 15 AAS users bodybuilders (G1), 20 non-users bodybuilders (G2) and 20 non-users sedentary (G3). MN analysis was performed on a minimum of 1000 binucleated lymphocytes. The occurrence of MN was significantly higher ( p < 0.05) in individuals of G1 compared to G2 and G3. The results indicate the sensitivity of CBMN in human lymphocytes in the identification of chromosomal damage in consequence of AAS.

  14. Significance of the proportion of binucleate cells in the micronucleus assay; A methodological study

    Energy Technology Data Exchange (ETDEWEB)

    Imamura, Masahiro; Edgren, M.R. (Karolinska Inst., Stockholm (Sweden). Dept. of Radiation Physics)

    1994-03-01

    Using treatment with cytochalasin-B (Cyt-B) for the induction of a cytokinetic block, the significance of the proportion of binucleate cells (BNC) in the micronucleus (MN) assay was investigated in a methodological study. A Chinese hamster cell line V79 was used in which MN were induced by radiation. In complementary tests the radiation effect in inducing MN was enhanced by depletion of the cellular glutathione content with buthionine sulfoximine (BSO). The data indicated that the concentration of Cyt-B is the major factor which determines the proportion of BNC. This proportion was shown to be independent of radiation dose and of BSO. Furthermore, the MN frequency was not related to the percentage of BNC. Therefore, a high proportion of BNC may be practical for the MN assay, but may not make the technique more accurate. (author).

  15. Significance of the proportion of binucleate cells in the micronucleus assay

    International Nuclear Information System (INIS)

    Imamura, Masahiro; Edgren, M.R.

    1994-01-01

    Using treatment with cytochalasin-B (Cyt-B) for the induction of a cytokinetic block, the significance of the proportion of binucleate cells (BNC) in the micronucleus (MN) assay was investigated in a methodological study. A Chinese hamster cell line V79 was used in which MN were induced by radiation. In complementary tests the radiation effect in inducing MN was enhanced by depletion of the cellular glutathione content with buthionine sulfoximine (BSO). The data indicated that the concentration of Cyt-B is the major factor which determines the proportion of BNC. This proportion was shown to be independent of radiation dose and of BSO. Furthermore, the MN frequency was not related to the percentage of BNC. Therefore, a high proportion of BNC may be practical for the MN assay, but may not make the technique more accurate. (author)

  16. Micronucleus formation in cultured human keratinocytes following exposure to mitomycin C and cyclophosphamide.

    Science.gov (United States)

    van Pelt, F N; Haring, R M; Overkamp, M J; Weterings, P J

    1991-02-01

    A method is described to investigate the induction of micronuclei in cultured human keratinocytes after short-term exposure to known clastogenic agents. The cytokinesis-block method was applied to facilitate the scoring of micronucleated cells. Mitomycin C, a direct-acting compound, caused a 5-20-fold increase in micronuclei over the controls at the highest concentration tested (1 microgram/ml). Cyclophosphamide, an agent requiring metabolic activation, did not induce the formation of micronuclei in cultured keratinocytes. However, after pretreatment of the keratinocyte cultures with Aroclor 1254 for 72 h, exposure to cyclophosphamide resulted in a 3-fold increase in micronucleus frequency over the controls. No cytogenetic effect of Aroclor 1254 was observed in control experiments.

  17. The complement inhibitor eculizumab in paroxysmal nocturnal hemoglobinuria.

    NARCIS (Netherlands)

    Hillmen, P.; Young, N.S.; Schubert, J.; Brodsky, R.A.; Socie, G.; Muus, P.; Roth, A.; Szer, J.; Elebute, M.O.; Nakamura, R.; Browne, P.; Risitano, A.M.; Hill, A.; Schrezenmeier, H.; Fu, C.L.; Maciejewski, J; Rollins, S.A.; Mojcik, C.F.; Rother, R.P.; Luzzatto, L.

    2006-01-01

    BACKGROUND: We tested the safety and efficacy of eculizumab, a humanized monoclonal antibody against terminal complement protein C5 that inhibits terminal complement activation, in patients with paroxysmal nocturnal hemoglobinuria (PNH). METHODS: We conducted a double-blind, randomized,

  18. Analysis of the Genotoxic Effects of Mobile Phone Radiation using Buccal Micronucleus Assay: A Comparative Evaluation.

    Science.gov (United States)

    Banerjee, Sumita; Singh, Narendra Nath; Sreedhar, Gadiputi; Mukherjee, Saikat

    2016-03-01

    Micronucleus (MN) is considered to be a reliable marker for genotoxic damage and it determines the presence and the extent of the chromosomal damage. The MN is formed due to DNA damage or chromosomal disarrangements. The MN has a close association with cancer incidences. In the new era, mobile phones are constantly gaining popularity specifically in the young generation, but this device uses radiofrequency radiation that may have a possible carcinogenic effect. The available reports related to the carcinogenic effect of mobile radiation on oral mucosa are contradictory. To explore the effects of mobile phone radiation on the MN frequency in oral mucosal cells. The subjects were divided into two major groups: low mobile phone users and high mobile phone users. Subjects who used their mobile phone since less than five years and less than three hours a week comprised of the first group and those who used their mobile since more than five years and more than 10 hours a week comprised of the second group. Net surfing and text messaging was not considered in this study. Exfoliated buccal mucosal cells were collected from both the groups and the cells were stained with DNA-specific stain acridine orange. Thousand exfoliated buccal mucosal cells were screened and the cells which were positive for micronuclei were counted. The micronucleus frequency was represented as mean±SD, and unpaired Student t-test was used for intergroup comparisons. The number of micronucleated cells/ 1000 exfoliated buccal mucosal cells was found to be significantly increased in high mobile phone users group than the low mobile phone users group. The use of mobile phone with the associated complaint of warmth around the ear showed a maximum increase in the number of micronucleated cells /1000 exfoliated buccal mucosal cells. Mobile phone radiation even in the permissible range when used for longer duration causes significant genotoxicity. The genotoxicity can be avoided to some extent by the

  19. Complement activation by Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Jensen, E T; Kharazmi, A; Garred, P

    1993-01-01

    In chronic infections, such as the bronchopulmonary Pseudomonas aeruginosa infection in cystic fibrosis (CF) patients, bacteria persist despite an intact host immune defense and frequent antibiotic treatment. An important reason for the persistence of the bacteria is their capacity for the biofilm...... mode of growth. In this study we investigated the role of biofilms in activation of complement, a major contributor to the inflammatory process. Complement activation by P. aeruginosa was examined in a complement consumption assay, production of C3 and factor B conversion products assessed by crossed...... immuno-electrophoresis, C5a generation tested by a PMN chemotactic assay, and terminal complement complex formation measured by ELISA. Two of the four assays showed that P. aeruginosa grown in biofilm activated complement less than planktonic bacteria, and all assays showed that activation by intact...

  20. An improved in vitro micronucleus assay to biological dosimetry

    International Nuclear Information System (INIS)

    Ocampo, Ivette Z.; Okazaki, Kayo; Vieira, Daniel P.

    2013-01-01

    The biological dosimetry is widely used to estimate the absorbed dose in people occupationally or accidentally exposed to the radiation for a better medical treatment, minimizing the harmful effects. Many techniques and methods have been proposed to detect and quantify the radioinduced lesions in genetic material, among them, the micronucleus (MN) assay. In the present study, we proposed an improved in vitro micronucleus technique that is rapid, sensitive and with minor cell manipulations. Assays were carried out with human tumor cells (MCF-7) seeded (3x10 4 cells) in slides placed into Petri dishes. Adherent cells were maintained with RPMI medium, supplemented with fetal calf serum, 1 % antibiotics, cytochalasin B (2 μg/mL), and incubated at 37 deg C in the presence of 5% CO2 for 72h. Cells were pre-treated for 24h with aminoguanidine, a nitric oxide synthase inhibitor. Nitric oxide is an intracellular free-radical, involved in DNA double-strand break repair mechanisms. After incubation, adherent cells on slides were briefly fixed with paraformaldehyde and stained with acridine orange (100 μg/mL) for analysis through fluorescence microscopy. Dye fluorescence permitted accurate discrimination between nuclei and micronuclei (bright green) and cytoplasm (red), and made possible a faster counting of binucleated cells. Aminoguanidine (2 mM) induced significant increase (p< 0.05) in frequencies of binucleated cells with micronuclei and in the number of micronuclei per binucleated cell. Data showed that proposed modifications permit to understand an early aspect of NO inhibition and suggested an improved protocol to MN assays. (author)

  1. Lattices with unique complements

    CERN Document Server

    Saliĭ, V N

    1988-01-01

    The class of uniquely complemented lattices properly contains all Boolean lattices. However, no explicit example of a non-Boolean lattice of this class has been found. In addition, the question of whether this class contains any complete non-Boolean lattices remains unanswered. This book focuses on these classical problems of lattice theory and the various attempts to solve them. Requiring no specialized knowledge, the book is directed at researchers and students interested in general algebra and mathematical logic.

  2. The cytokinesis-block micronucleus assay: a sensitive technique for measuring radiation-induced chromosome damage

    International Nuclear Information System (INIS)

    Fenech, M.; Morley, A.A.

    1987-01-01

    The sensitivity of the cytokinesis-block micronucleus assay was demonstrated by the detection in human lymphocytes of in vitro exposures of as low as 0.02 Gy of X-rays. To determine the suitability of this new method for measuring in vivo exposure to radiation the authors have performed initial longitudinal studies on (a) cancer patients undergoing partial body fractionated radiotherapy and (b) BALB-C mice following in vivo whole body irradiation with acute single doses of X-rays. The results for radiotherapy patients indicate that the dose fractions have an additive effect on the observed micronucleus frequency which appeared to decline following three months after completion of therapy. Results with irradiated mice showed a sharp increase in micronucleus frequency for splenocytes sampled immediately after treatment and the rate of decline in micronucleus frequency during the first week after treatment was dose-dependent. (author)

  3. GLUCOCORTICOSTEROIDS' EFFECT UPON THE COMPLEMENT LEVEL

    Directory of Open Access Journals (Sweden)

    Voja Pavlovic

    2001-03-01

    Full Text Available The effect of high doses of cortisol upon the level of the overall complements'hemolytic activity and particular complements' components is studies. The experimentsinvolved guinea pigs of male sex of the body mass from 300 to 400 g, namelythose that have not been treated by anything so far. The doses of hydrocortisone(Hemofarm DD were also used for the experiment. The overall complements'activity was determined by testing the capabilities of a series of various solutions ofthe guinea pigs' serum to separate sheep erythrocytes that were made sensitive byrabbit anti-erythrocyte antibodies. The determination of the C1, C2, C3 and C4complements' components was done by the method of the quantitative diffusion ofthe radial type by using the Partigen blocks Behringwerke AG. The series comprised25 guinea pigs of male sex. The low cortisol level rapidly increase the overallhemolytic activity of the complements of the C1 est erase concentration. Along withthe cortisol dose increase the overall hemolytic complements' activity is dropping aswell as that of the C1, C2, C3 and C4 complements' components.

  4. Material properties in complement activation

    DEFF Research Database (Denmark)

    Moghimi, S. Moein; Andersen, Alina Joukainen; Ahmadvand, Davoud

    2011-01-01

    activation differently and through different sensing molecules and initiation pathways. The importance of material properties in triggering complement is considered and mechanistic aspects discussed. Mechanistic understanding of complement events could provide rational approaches for improved material design...

  5. Genotoxic potential generated by biomass burning in the Brazilian Legal Amazon by Tradescantia micronucleus bioassay: a toxicity assessment study

    Directory of Open Access Journals (Sweden)

    Artaxo Paulo

    2011-05-01

    Full Text Available Abstract Background The Brazilian Amazon has suffered impacts from non-sustainable economic development, especially owing to the expansion of agricultural commodities into forest areas. The Tangará da Serra region, located in the southern of the Legal Amazon, is characterized by non-mechanized sugar cane production. In addition, it lies on the dispersion path of the pollution plume generated by biomass burning. The aim of this study was to assess the genotoxic potential of the atmosphere in the Tangará da Serra region, using Tradescantia pallida as in situ bioindicator. Methods The study was conducted during the dry and rainy seasons, where the plants were exposed to two types of exposure, active and passive. Results The results showed that in all the sampling seasons, irrespective of exposure type, there was an increase in micronucleus frequency, compared to control and that it was statistically significant in the dry season. A strong and significant relationship was also observed between the increase in micronucleus incidence and the rise in fine particulate matter, and hospital morbidity from respiratory diseases in children. Conclusions Based on the results, we demonstrated that pollutants generated by biomass burning in the Brazilian Amazon can induce genetic damage in test plants that was more prominent during dry season, and correlated with the level of particulates and elevated respiratory morbidity.

  6. Dynamics of interaction between complement-fixing antibody/dsDNA immune complexes and erythrocytes. In vitro studies and potential general applications to clinical immune complex testing

    International Nuclear Information System (INIS)

    Taylor, R.P.; Horgan, C.; Hooper, M.; Burge, J.

    1985-01-01

    Soluble antibody/ 3 H-double-stranded PM2 DNA (dsDNA) immune complexes were briefly opsonized with complement and then allowed to bind to human erythrocytes (via complement receptors). The cells were washed and subsequently a volume of autologous blood in a variety of media was added, and the release of the bound immune complexes from the erythrocytes was studied as a function of temperature and time. After 1-2 h, the majority of the bound immune complexes were not released into the serum during blood clotting at either 37 degrees C or room temperature, but there was a considerably greater release of the immune complexes into the plasma of blood that was anticoagulated with EDTA. Similar results were obtained using various conditions of opsonization and also using complexes that contained lower molecular weight dsDNA. Thus, the kinetics of release of these antibody/dsDNA immune complexes differed substantially from the kinetics of release of antibody/bovine serum albumin complexes that was reported by others. Studies using the solution phase C1q immune complex binding assay confirmed that in approximately half of the SLE samples that were positive for immune complexes, there was a significantly higher level of detectable immune complexes in plasma vs. serum. Freshly drawn erythrocytes from some SLE patients exhibiting this plasma/serum discrepancy had IgG antigen on their surface that was released by incubation in EDTA plasma. Thus, the higher levels of immune complexes observed in EDTA plasma vs. serum using the C1q assay may often reflect the existence of immune complexes circulating in vivo bound to erythrocytes

  7. Genotoxicity of freshwater ecosystem shows DNA damage in preponderant fish as validated by in vivo micronucleus induction in gill and kidney erythrocytes.

    Science.gov (United States)

    Obiakor, M O; Okonkwo, J C; Ezeonyejiaku, C D

    2014-12-01

    Genotoxicity of Anambra River was studied by micronucleus (MN) assay of preponderant fish species in the river. The micronucleus indices obtained were used as biomarker to estimate and predict pollution profile and possible danger of feeding on the aquatic species. Micronuclei profile of the fish was measured from gill and kidney erythrocytes using microscopic technique. Season, species and location effects on micronuclei, together with their interactions were also determined. Two major seasons (rainy and dry) and preponderant fish species in the river (Synodontis clarias, Linnaeus, 1758 and Tilapia nilotica, Linnaeus, 1757) were studied at five distinct locations that displayed differential environmental stresses. The study showed that the micronucleus index of fish is an excellent biomarker for measuring pollution level and genotoxicity of freshwater habitat. Season, species of fish and location affect micronuclei profile of the fish species sampled in the river. Disease outbreak among rural dwellers depending on the river for domestic and other uses is imminent and they lack knowledge on its health implication. Moreover, the study maintained that the micronuclei in fish could be measured from either the gill or kidney; however, gill is more efficient as it enables collection of several samples from the same individuals without sacrificing it, and Synodontis clarias fish species appeared to be more vulnerable to the genotoxic damage than Tilapia nilotica. Consequently, the study recommended regular monitoring (micronucleus tests) of edible aquatic life such as Synodontis clarias in order to eliminate the danger of people feeding on toxic metals, some of which are carcinogenic. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Complementing Gender Analysis Methods.

    Science.gov (United States)

    Kumar, Anant

    2016-01-01

    The existing gender analysis frameworks start with a premise that men and women are equal and should be treated equally. These frameworks give emphasis on equal distribution of resources between men and women and believe that this will bring equality which is not always true. Despite equal distribution of resources, women tend to suffer and experience discrimination in many areas of their lives such as the power to control resources within social relationships, and the need for emotional security and reproductive rights within interpersonal relationships. These frameworks believe that patriarchy as an institution plays an important role in women's oppression, exploitation, and it is a barrier in their empowerment and rights. Thus, some think that by ensuring equal distribution of resources and empowering women economically, institutions like patriarchy can be challenged. These frameworks are based on proposed equality principle which puts men and women in competing roles. Thus, the real equality will never be achieved. Contrary to the existing gender analysis frameworks, the Complementing Gender Analysis framework proposed by the author provides a new approach toward gender analysis which not only recognizes the role of economic empowerment and equal distribution of resources but suggests to incorporate the concept and role of social capital, equity, and doing gender in gender analysis which is based on perceived equity principle, putting men and women in complementing roles that may lead to equality. In this article the author reviews the mainstream gender theories in development from the viewpoint of the complementary roles of gender. This alternative view is argued based on existing literature and an anecdote of observations made by the author. While criticizing the equality theory, the author offers equity theory in resolving the gender conflict by using the concept of social and psychological capital.

  9. Inhibitory effects of Enteromorpha linza polysaccharide on micronucleus of Allium sativum root cells.

    Science.gov (United States)

    Zhang, Zhongshan; Wang, Xiaomei; Li, Jingfen; Liu, Chongbin; Zhang, Quanbin

    2016-06-01

    In this study, the antimutagenic function of the polysaccharide from Enteromorpha linza with the micronucleus test of Allium sativum root cells induced by sulfur dioxide and ultraviolet was studied. The concentration-effect relation of the two inducers was firstly evaluated. The results showed that an increase of genotoxicity damage was demonstrated and micronuclei frequency induced by sulfur dioxide and ultraviolet displayed dose dependent increases. All the doses of polysaccharide did affect the micronuclei frequency formation compared with the negative control. And also, the significant increase in inhibition rate of micronuclei frequency was observed with the increase of the dose of polysaccharide. It was showed maximum inhibition of micronuclei frequency cells (71.74% and 66.70%) at a concentration of 200g/mL in three experiments. The low molecular weight polysaccharide showed higher inhibition rate than raw polysaccharide at the higher concentration (50g/mL) in the absence of sulfur dioxide and ultraviolet. It was confirmed to be a good mutant inhibitor. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Micronucleus Assay in Exfoliated Buccal Epithelial Cells Using Liquid Based Cytology Preparations in Building Construction Workers.

    Science.gov (United States)

    Arul, P; Smitha, Shetty; Masilamani, Suresh; Akshatha, C

    2018-01-01

    Cytogenetic damage in exfoliated buccal epithelial cells due to environmental and occupational exposure is often monitored by micronucleus (MN) assay using liquid based cytology (LBC) preparations. This study was performed to evaluate MN in exfoliated buccal epithelial cells of building construction workers using LBC preparations. LBC preparations of exfoliated buccal epithelial cells from 100 subjects [50 building construction workers (cases) and 50 administrative staffs (controls)] was evaluated by May-Grunwald Giemsa, Hematoxylin and Eosin and Papanicolaou stains. Student's t test was used for statistical analysis and a P value of 5 years) and smokers and non-smokers of cases (P=0.001). However, there were meaningful differences regarding mean frequencies of MN between smokers, non-smokers, those with alcohol consumption or not in cases and controls using various stains (P=0.001). There was an increased risk of cytogenetic damage in building construction workers. However, evaluation of MN of exfoliated buccal epithelial cells in building construction workers serve as a minimally invasive biomarker for cytogenetic damage. LBC preparations can be applied for MN assay as it improves the quality of smears and cell morphology, decreases the confounding factors and reduces false positive results.

  11. Shark complement: an assessment.

    Science.gov (United States)

    Smith, S L

    1998-12-01

    The classical (CCP) and alternative (ACP) pathways of complement activation have been established for the nurse shark (Ginglymostoma cirratum). The isolation of a cDNA clone encoding a mannan-binding protein-associated serine protease (MASP)-1-like protein from the Japanese dogfish (Triakis scyllia) suggests the presence of a lectin pathway. The CCP consists of six functionally distinct components: C1n, C2n, C3n, C4n, C8n and C9n, and is activated by immune complexes in the presence of Ca++ and Mg++ ions. The ACP is antibody independent, requiring Mg++ ions and a heat-labile 90 kDa factor B-like protein for activity. Proteins considered homologues of C1q, C3 and C4 (C2n) of the mammalian complement system have been isolated from nurse shark serum. Shark C1q is composed of at least two chain types each showing 50% identity to human C1q chains A and B. Partial sequence of the globular domain of one of the chains shows it to be C1q-like rather than like mannan-binding protein. N-terminal amino acid sequences of the alpha and beta chain of shark C3 and C4 molecules show significant identity with corresponding human C3 and C4 chains. A sequence representing shark C4 gamma chain, shows little similarity to human C4 gamma chain. The terminal shark components C8n and C9n are functional analogues of mammalian C8 and C9. Anaphylatoxin activity has been demonstrated in activated shark serum, and porcine C5a desArg induces shark leucocyte chemotaxis. The deduced amino acid sequence of a partial C3 cDNA clone from the nurse shark shows 50%, 30% and 24% homology with the corresponding region of mammalian C3, C4 and alpha 2-macroglobulin. Deduced amino acid sequence data from partial Bf/C2 cDNA clones, two from the nurse shark and one from the Japanese dogfish, suggest that at least one species of elasmobranch has two distinct Bf/C2 genes.

  12. Micronucleus formation compared to the survival rate of human melanoma cells after X-ray and neutron irradiation and hyperthermia

    Energy Technology Data Exchange (ETDEWEB)

    van Beuningen, D.; Streffer, C.; Bertholdt, G.

    1981-09-01

    After neutron and X-ray irradiation and combined X-ray irradiation and hyperthermia (3 hours, 42/sup 0/C), the survival rate of human melanoma cells was measured by means of the colony formation test and compared to the formation of micronuclei. Neutrons had a stronger effect on the formation of micronuclei than the combination of X-rays and hyperthermia. X-rays had the lowest effect. The dose effect curve showed a break at that dose level at which a reduction of cells was observed in the cultures. A good relation between survival rate and formation of micronuclei was found for the X-ray irradiation, but not for the neutron irradiation and the combined treatment. These observations are discussed. At least for X-rays, the micronucleus test has turned out to be a good screening method for the radiosensitivity of a biologic system.

  13. Evaluation of genotoxicity after application of Listerine(R) on human lymphocytes by micronucleus and single cell gel electrophoresis assays.

    Science.gov (United States)

    Türkez, Hasan; Togar, Basak; Arabaci, Taner

    2012-04-01

    Listerine (LN) is one of the most commonly used mouth rinses worldwide although very limited information is available concerning its genotoxicity. In another view, the biological safety profile of oral care products is frequently assumed on the basis of simplistic test models. Therefore, the present study was undertaken to investigate the in vitro genotoxic potential of LN using micronucleus and single cell gel electrophoresis tests as genetic endpoints. Different concentrations of LN (0-100% of ml/culture, v/v) were applied to whole human blood cultures (n = 5). The result of the present study showed that there were no statistically significant differences (p > 0.05) between the control group and the groups treated with LN alone in both analysed endpoints. In conclusion, our result first demonstrated the absence of genotoxicity of LN on human lymphocytes.

  14. Nanomedicine and the complement paradigm.

    Science.gov (United States)

    Moghimi, S Moein; Farhangrazi, Z Shadi

    2013-05-01

    The role of complement in idiosyncratic reactions to nanopharmaceutical infusion is receiving increasing attention. We discuss this in relation to nanopharmaceutical development and the possible use of complement inhibitors to prevent related adverse reactions. We further call on initiation of genetic association studies to unravel the genetic basis of nanomedicine infusion-related adverse responses, since most of the polymorphic genes in the genome belong to the immune system. In this paper, idiosyncratic reactions based on complement activation are discussed in the context of newly available complement inhibitors. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Application of liquid-based cytology preparation in micronucleus assay of exfoliated buccal epithelial cells in road construction workers.

    Science.gov (United States)

    Arul, P

    2017-01-01

    Asphalts are bitumens that consist of complex of hydrocarbon mixtures and it is used mainly in road construction and maintenance. This study was undertaken to evaluate the micronucleus (MN) assay of exfoliated buccal epithelial cells in road construction workers using liquid-based cytology (LBC) preparation. Three different stains (May-Grunwald Giemsa, hematoxylin and eosin, and Papanicolaou) were used to evaluate the frequency of MN in exfoliated buccal epithelial of 100 participants (fifty road construction workers and fifty administrative staff) using LBC preparation. Statistical analysis was performed with Student's t-test, and Proad construction exhibit a higher frequency of MN in exfoliated buccal epithelial cells and they are under the significant risk of cytogenetic damage. LBC preparation has potential application for the evaluation of frequency of MN. This technique may be advocated in those who are occupationally exposed to potentially carcinogenic agents in view of improvement in the smear quality and visualization of cell morphology.

  16. Micronucleus induction by repeated exposure of diagnostic X-ray on oral buccal mucosa

    International Nuclear Information System (INIS)

    Lohith Tejashvi, K.; Suchetha Kumari, N.; Shetty, Shishir Ram

    2012-01-01

    Radiography is the important diagnostic tools essential for diagnosis and planning of orthodontic treatment. X-ray is ionizing radiation which showed various effects include breaking the bond of biological molecules, inducing loss of ability of cell death, increases nuclear alterations. Micronuclei - x000D - (MN) are small chromatin bodies that appear in the cytoplasm by the - x000D - condensation of acrocentric chromosomal fragments or by whole chromosomes. This - x000D - is a sensitive indicator of genetic damage. - x000D - x000D - . To evaluate micronucleus induction by repeated exposure of diagnostic X-ray on human buccal cell. Methods: 25 patients who visiting to ABSMIDS, Department of Oral medicine and Radiology for dental checkup exposed to diagnostic X-ray more than 4 times have been selected for this study. The buccal cell for analysis was collected from the cheek mucosa by means of gentle scraping of epithelial using ice-cream sticks and placed in Buffer saline. This sample was smeared on glass slide and then fixed in methanol:glacial acetic acid (3:1). Air dried and stained with Giemsa for 15-25 minutes. Then 250 cells in each slides were analyzed under microscope and frequency of micronucleus was scored (n=4). Repeated X-ray exposed cells showed micronucleus (1.25%) and nuclear alteration (2.3%) compare to the control. Repeated X-ray exposure leads to induces detectable number of micronucleus and nuclear alterations. (author)

  17. Complement Evasion by Pathogenic Leptospira.

    Science.gov (United States)

    Fraga, Tatiana Rodrigues; Isaac, Lourdes; Barbosa, Angela Silva

    2016-01-01

    Leptospirosis is a neglected infectious disease caused by spirochetes from the genus Leptospira . Pathogenic microorganisms, notably those which reach the blood circulation such as Leptospira , have evolved multiple strategies to escape the host complement system, which is important for innate and acquired immunity. Leptospira avoid complement-mediated killing through: (i) recruitment of host complement regulators; (ii) acquisition of host proteases that cleave complement proteins on the bacterial surface; and, (iii) secretion of proteases that inactivate complement proteins in the Leptospira surroundings. The recruitment of host soluble complement regulatory proteins includes the acquisition of Factor H (FH) and FH-like-1 (alternative pathway), C4b-binding protein (C4BP) (classical and lectin pathways), and vitronectin (Vn) (terminal pathway). Once bound to the leptospiral surface, FH and C4BP retain cofactor activity of Factor I in the cleavage of C3b and C4b, respectively. Vn acquisition by leptospires may result in terminal pathway inhibition by blocking C9 polymerization. The second evasion mechanism lies in plasminogen (PLG) binding to the leptospiral surface. In the presence of host activators, PLG is converted to enzymatically active plasmin, which is able to degrade C3b, C4b, and C5 at the surface of the pathogen. A third strategy used by leptospires to escape from complement system is the active secretion of proteases. Pathogenic, but not saprophytic leptospires, are able to secrete metalloproteases that cleave C3 (central complement molecule), Factor B (alternative pathway), and C4 and C2 (classical and lectin pathways). The purpose of this review is to fully explore these complement evasion mechanisms, which act together to favor Leptospira survival and multiplication in the host.

  18. Bio-monitoring for the genotoxic assessment in road construction workers as determined by the buccal micronucleus cytome assay.

    Science.gov (United States)

    Çelik, Ayla; Yildirim, Seda; Ekinci, Seda Yaprak; Taşdelen, Bahar

    2013-06-01

    Buccal micronucleus cytome (BMCyt) assay monitors genetic damage, cell proliferation and cell death in humans exposed to occupational and environmental agents. BMCyt is used as an indicator of genotoxic exposure, since it is associated with chromosomal instability. There is little research on the occupational exposure among road construction workers for genotoxicity testing. In the present study, we evaluated MN frequencies and other nuclear changes, karyorrhexis (KR), karyolysis (KL), broken egg (BE), binucleate (BN), condensed chromatin cell (CCC), and picnotic cell (PC) in buccal mucosa cells of 40 road construction workers (twenty smokers and twenty non-smokers) and 40 control groups consisting of healthy persons (twenty smokers and twenty non-smokers). Microscopic observation was performed of 2000 cells per individual in both road construction workers and control group. In control and worker groups, for each person repair index (RI) was calculated via formula KR+L/BE+MN. The results showed a statistically significant increase in the frequency of MN in buccal epithelial cells of exposed group compared with control group (proad construction workers, RI is lower than the control group. There is a significant difference between workers and control group (proad paving operations are absorbed by workers and that asphalt fume exposure is able to significantly induce cytogenetic damage in buccal mucosa cells of workers after controlling some possible confounding factors, such as age, sex and smoking habits. In addition to determination of nuclear changes and the micronucleus, the determination of RI value presents a new approach to genotoxic bio-monitoring assessment studies of occupationally exposed population. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. Sacha Inchi (Plukenetia volubilis L. powder: acute toxicity, 90 days oral toxicity study and micronucleus assay in rodents

    Directory of Open Access Journals (Sweden)

    Idania Rodeiro

    2018-02-01

    Full Text Available Context: Sacha Inchi has been consumed for years by indigenous peoples. Meanwhile, its toxicological potential has not been sufficiently studied. Aims: To assess the acute, sub-chronic toxicity and genotoxicity evaluation of Sacha Inchi powder obtained from Plukenetia volubilis L. Methods: A dose of 2000 mg/kg was orally administered to rats and mice and toxicity symptoms for 14 days were observed. In repeated dose study, the product was orally administered to Sprague Dawley rats of both sexes. Animals received 50, 250 and 500 mg/kg/day of the product for 90 days. At the end, animals were sacrificed and samples were done for hematological and biochemical analysis, organ weighs and histopathological examination. Genotoxicity potential of Sacha Inchi powder was evaluated through micronucleus test in mice. Negative controls received the vehicle (carboxymethyl cellulose, 0.5% used. Results: No morbidity or mortality at 2000 mg/kg of the product were found. Sacha Inchi powder oral administration during 90 days to rats did not lead to death, body weight gain, food consumption, or adverse events. No significant changes on hematological or biochemical parameters, organ weights or histopathological findings were observed. Induction of micronucleus formation attributable to the product was not found in mice. Conclusions: No toxicity effects after oral acute exposure of Sacha Inchi power to rats and mice were observed. Neither toxicity attributable to oral doses of the product up to 500 mg/kg during 90 days to rats were found. Results suggested Sacha Inchi powder does not have genotoxicity potential under our experimental conditions.

  20. Dose-rate effects for apoptosis and micronucleus formation in gamma-irradiated human lymphocytes

    International Nuclear Information System (INIS)

    Boreham, D.R.; Dolling, J.-A.; Maves, S.R.; Siwarungsun, N.; Mitchel, R.E.J.

    2000-01-01

    We have compared dose-rate effects for γ-radiation-induced apoptosis and micronucleus formation in human lymphocytes. Long-term assessment of individual radiation-induced apoptosis showed little intraindividual variation but significant interindividual variation. The effectiveness of radiation exposure to cause apoptosis or micronucleus formation was reduced by low-dose-rate exposures, but the reduction was apparent at different dose rates for these two end points. Micronucleus formation showed a dose-rate effect when the dose rate was lowered to 0.29 cGy/min, but there was no accompanying cell cycle delay. A further increase in the dose-rate effect was seen at 0.15 cGy/min, but was now accompanied by cell cycle delay. There was no dose-rate effect for the induction of apoptosis until the dose rate was reduced to 0.15 cGy/min, indicating that the mechanisms or signals for processing radiation-induced lesions for these two end points must be different at least in part. There appear to be two mechanisms that contribute to the dose-rate effect for micronucleus formation. One of these does not affect binucleate cell frequency and occurs at dose rates higher than that required to produce a dose-rate effect for apoptosis, and one affects binucleate cell frequency, induced only at the very low dose rate which coincidentally produces a dose-rate effect for apoptosis. Since the dose rate at which cells showed reduced apoptosis as well as a further reduction in micronucleus formation was very low, we conclude that the processing of the radiation-induced lesions that induce apoptosis, and some micronuclei, is very slow in quiescent and PHA-stimulated lymphocytes, respectively. (author)

  1. Dose-rate effects for apoptosis and micronucleus formation in gamma-irradiated human lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Boreham, D.R.; Dolling, J.-A.; Maves, S.R. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Siwarungsun, N. [Chulalongkorn Univ., Bangkok (Thailand); Mitchel, R.E.J. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2000-07-01

    We have compared dose-rate effects for {gamma}-radiation-induced apoptosis and micronucleus formation in human lymphocytes. Long-term assessment of individual radiation-induced apoptosis showed little intraindividual variation but significant interindividual variation. The effectiveness of radiation exposure to cause apoptosis or micronucleus formation was reduced by low-dose-rate exposures, but the reduction was apparent at different dose rates for these two end points. Micronucleus formation showed a dose-rate effect when the dose rate was lowered to 0.29 cGy/min, but there was no accompanying cell cycle delay. A further increase in the dose-rate effect was seen at 0.15 cGy/min, but was now accompanied by cell cycle delay. There was no dose-rate effect for the induction of apoptosis until the dose rate was reduced to 0.15 cGy/min, indicating that the mechanisms or signals for processing radiation-induced lesions for these two end points must be different at least in part. There appear to be two mechanisms that contribute to the dose-rate effect for micronucleus formation. One of these does not affect binucleate cell frequency and occurs at dose rates higher than that required to produce a dose-rate effect for apoptosis, and one affects binucleate cell frequency, induced only at the very low dose rate which coincidentally produces a dose-rate effect for apoptosis. Since the dose rate at which cells showed reduced apoptosis as well as a further reduction in micronucleus formation was very low, we conclude that the processing of the radiation-induced lesions that induce apoptosis, and some micronuclei, is very slow in quiescent and PHA-stimulated lymphocytes, respectively. (author)

  2. Effects of electromagnetic fields induced from the visual display terminal on the micronucleus frequencies in tradescantia

    International Nuclear Information System (INIS)

    Shin, Hae Shik; Kim, Jin Kyu; Lee, Jin Hong

    2002-01-01

    Humans are exposed daily to electromagnetic fields (EMFs) originating from a variety of devices and VDT (Visual Display Terminal) workstations. This research was designed to examine the biological effects of electromagnetic fields from VDT using the Tradescantia- micronuclesus (Trad-MCN) bioassay. Tradescantia BNL 4430 clone was used to evaluate the influence of EMFs radiated from the VDT workstation. Trad-MCN assay is a cytogenetic test based on the formation of micronuclei that result from chromosome breakage in the meiotic pollen mother cells. No study has established unequivocally a causal relationship between EMFs and animals or plants. Fresh cuttings bearing young flower buds were exposed for 24hours in front of the VDT workstation. The cuttings were placed at 30, 50, 70, and 90cm distances from the workstations. The micronucleus were scored under a light microscope (400 x magnification). Three hundreds of tetrads were scored from each of the slides in every the experimental group. The frequencies expressed in terms of MCN / 100 tetrads. Trad-MCN frequencies were 8.93 ± 0.32, 11.2 ± 0.50, 7.67 ± 0.61, and 6.22 ± 1.78/ 100 tetrads at 30, 50, 70, and 90cm, respectively. In conclusion, EMFs from VDT give rise to damage the chromosome this plant. In addition, The results of the study indicate that Trad-MCN assay can detect chromosome damage due to EMFs from the electrical device workstation. In conclusion, the Trad-MCN assay is sensitive, reproducible, easy to perform, well standardized, inexpensive and undemanding in equipment

  3. Micronucleus evaluation for determining the chromosomal breakages after radionuclide synovectomy in patients with hemophilia

    International Nuclear Information System (INIS)

    Kavakli, K.; Cogulu, O.; Karaca, E.

    2012-01-01

    To investigate the genotoxic effects of 90 Y and 186 Re in patients with hemophilia who were undergoing radionuclide synovectomy (RS) procedure in the last 3 years. Nineteen patients were enrolled in the study. Most of the patients (n=17) were hemophilia-A (mean age 20.6±10.5 years) and 18 patients (mean age 22.6±10.6 years) with hemophilia who were not exposed to RS procedure were included in the study as control group. Most cases in the control group (n=13) were hemophilia-A. 90 Y for knee joints and 186 Re for elbow or ankle joints were used to perform RS in hemophilic patients. We studied the micronucleus (MN) test on peripheral blood lymphocytes as an indicator of radiation-induced cytogenetic damage and calculated nuclear division index. There was no significant difference between the patients with and without RS with respect to MN values. However, both values obtained in RS-exposed patients and control group were much elevated than values reported in literature from healthy controls. The mean MN values of patients below 20 years old were much lower but not significant than those above 20 years old. MN frequencies between 186 Re and 90 Y groups were also analyzed, and no significant difference was observed. Hemophilia patients who were treated with 186 Re showed higher levels of MN compared to patients treated with 90 Y although the difference was not significant. Radioisotope synovectomy (RS) seems to be a safe procedure not causing a significant genotoxic effect on hemophilic patients, however, further studies including larger series of patients are needed to better understand the effects of RS on patients' health. (author)

  4. A comparison of two agar gel immunodiffusion methods and a complement fixation test for serologic diagnosis of Brucella ovis infection in experimentally infected rams

    Directory of Open Access Journals (Sweden)

    M.N. Xavier

    2011-08-01

    Full Text Available A infecção por Brucella ovis é considerada uma das principais causas de epididimite e infertilidade em carneiros, resultando em falhas reprodutivas e perdas econômicas significativas em rebanhos ovinos ao redor do mundo. O estudo teve o objetivo de avaliar três testes sorológicos disponíveis para o diagnóstico da brucelose ovina por B. ovis, utilizando 181 soros ovinos. Amostras de soro provenientes de carneiros experimentalmente infectados foram coletadas ao longo de 192 dias pós-infecção (n=117 e durante o período pré-infecção (n=9. Adicionalmente, amostras de soro foram obtidas de ovinos provenientes de um rebanho livre para B. ovis (n=55. As técnicas de imunodifusão em gel de agar (IDGA, utilizando dois antígenos disponíveis comercialmente, e de fixação de complemento foram comparadas (FC. Foram obtidos resultados de sensibilidade especificidade semelhantes para ambos os métodos de IDGA e ainda, a técnica de IDGA foi mais eficiente do que a da FC para o diagnóstico sorológico da infecção por B. ovis.

  5. Elaboration of data and documents intended to complement and expand the German series of nuclear engineering codes. 3. Technical report. Non-destructive testing of austenitic welds and claddings

    International Nuclear Information System (INIS)

    Waidele, H.

    1997-01-01

    This 3. technical report presents a literature study on non-destructive testing of austenitic welds and claddings. NDT of claddings was the subject of a previous BMU project report SR 2024, so that this report contains only an update covering the latest developments in this subject area, and NDT of austenitic welds is the major subject of the report in hand. The literature study shows that improvements of ultrasonic test results for austenitic welds are expected to be achieved soon as a result of application of novel testing methods, advanced signal processing algorithms, and reduced anisotropy of austenitic welds due to specific welding techniques. Enhanced information is expected to be achieved from radiography tests through improvements available now, such as digitization of conventional radiographs combined with computer-assisted evaluation methods. As to the inspection of components with wall thickness up to 10 mm, low-frequency methods or eddy current methods will increasingly be applied in future as complementing methods supplying additional information. (orig./CB) [de

  6. State of the Art High-Throughput Approaches to Genotoxicity: Flow Micronucleus, Ames II, GreenScreen and Comet

    Science.gov (United States)

    State of the Art High-Throughput Approaches to Genotoxicity: Flow Micronucleus, Ames II, GreenScreen and Comet (Presented by Dr. Marilyn J. Aardema, Chief Scientific Advisor, Toxicology, Dr. Leon Stankowski, et. al. (6/28/2012)

  7. Force Dynamics of Verb Complementation

    Directory of Open Access Journals (Sweden)

    Jacek Woźny

    2015-12-01

    Full Text Available Force Dynamics of Verb Complementation The concepts of motion and force are both extensively discussed in cognitive linguistics literature. But they are discussed separately. The first usually in the context of ‘motion situations’ (Talmy, Slobin, Zlatev, the other as part of the Force Dynamics framework, which was developed by Talmy. The aim of this paper is twofold: first, to argue that the concepts of force and motion should not be isolated but considered as two inseparable parts of force-motion events. The second goal is to prove that the modified Force Dynamics (force-motion framework can be used for precise characterization of the verb complementation patterns. To this end, a random sample of 50 sentences containing the verb ‘went’ is analyzed, demonstrating the differences between the categories of intensive and intransitive complementation with respect to the linguistically coded parameters of force and motion.

  8. Complement: Alive and Kicking Nanomedicines

    DEFF Research Database (Denmark)

    Andersen, Alina Joukainen; Hashemi, S.H.; Andresen, Thomas Lars

    2009-01-01

    Administration of liposome- and polymer-based clinical nanomedicines, as well as many other proposed multifunctional nanoparticles, often triggers hypersensitivity reactions without the involvement of IgE. These anaphylactic reactions are believed to be secondary to activation of the complement...... their procoagulant activity, and has the capacity to elicit non-lytic stimulatory responses from vascular endothelial cells. Here we discuss the molecular basis of complement activation by liposomes, including poly(ethylene glycol) coated vesicles, and other related lipid-based and phospholipid-poly(ethylene glycol...

  9. Analysis of resveratrol and radiation effects in lung cancer cells by micronucleus assay

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Carolina S.; Santos, Dymes R.A.; Vieira, Daniel P.; Rogero, Sizue O.; Rogero, Jose R., E-mail: carolina_sm@hotmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Sakuraba, Roberto K.; Weltman, Eduardo [Hospital Israelita Albert Einstein, Sao Paulo, SP (Brazil); Cruz, Aurea S.; Santos, Rezolina P. [Instituto Adolfo Lutz, Sao Paulo, SP (Brazil)

    2015-07-01

    Mucoepidermoid lung carcinoma is frequently manifested by obstructive trachea symptoms. Radiation and drugs combinations are commonly used in the lung cancer treatment. Currently there is a strong tendency to develop therapeutic strategies focused at the administration of high potential compounds to improve the ionizing radiation treatments, so as to increase the radiation effects on tumor cell while minimizing these effects to surrounding normal tissues. Resveratrol is a polyphenolic phytoalexin compound present in wines and several plants. This compound has a broad spectrum of biological activities such as antioxidant, anticarcinogenic, and induction of cell cycle arrest effects. Analysis of biological effects of ionizing radiation in the presence of resveratrol in different cell cultures has been the subject of many studies. To verify the genotoxic effects in cells exposed to ionizing radiation many methods have been proposed. The cytokinesis-block micronucleus technique is one of the preferred methods. The main of this study was to detect and quantify radioinduced DNA damage in mucoepidermoid lung carcinoma cells (NCI-H292) by cytokinesis-block micronucleus technique using cytocalasin-B. The cell culture was irradiated at a single fraction from a TrueBeam® linear accelerator (0, 0.8, 5, and 10 Gy), in the absence or presence of different resveratrol concentrations (0, 15, 30, and 60 μM). The results showed that resveratrol (15 and μM) induced significant increase frequency (p<0.05) of micronucleus formation in NCI-H292 cell culture non-irradiated and exposed at 5 Gy dose. Moreover, resveratrol (30 μM) induced micronucleus formation at 0.8 Gy dose. (author)

  10. Analysis of resveratrol and radiation effects in lung cancer cells by micronucleus assay

    International Nuclear Information System (INIS)

    Moreno, Carolina S.; Santos, Dymes R.A.; Vieira, Daniel P.; Rogero, Sizue O.; Rogero, Jose R.; Sakuraba, Roberto K.; Weltman, Eduardo; Cruz, Aurea S.; Santos, Rezolina P.

    2015-01-01

    Mucoepidermoid lung carcinoma is frequently manifested by obstructive trachea symptoms. Radiation and drugs combinations are commonly used in the lung cancer treatment. Currently there is a strong tendency to develop therapeutic strategies focused at the administration of high potential compounds to improve the ionizing radiation treatments, so as to increase the radiation effects on tumor cell while minimizing these effects to surrounding normal tissues. Resveratrol is a polyphenolic phytoalexin compound present in wines and several plants. This compound has a broad spectrum of biological activities such as antioxidant, anticarcinogenic, and induction of cell cycle arrest effects. Analysis of biological effects of ionizing radiation in the presence of resveratrol in different cell cultures has been the subject of many studies. To verify the genotoxic effects in cells exposed to ionizing radiation many methods have been proposed. The cytokinesis-block micronucleus technique is one of the preferred methods. The main of this study was to detect and quantify radioinduced DNA damage in mucoepidermoid lung carcinoma cells (NCI-H292) by cytokinesis-block micronucleus technique using cytocalasin-B. The cell culture was irradiated at a single fraction from a TrueBeam® linear accelerator (0, 0.8, 5, and 10 Gy), in the absence or presence of different resveratrol concentrations (0, 15, 30, and 60 μM). The results showed that resveratrol (15 and μM) induced significant increase frequency (p<0.05) of micronucleus formation in NCI-H292 cell culture non-irradiated and exposed at 5 Gy dose. Moreover, resveratrol (30 μM) induced micronucleus formation at 0.8 Gy dose. (author)

  11. Evaluation of repeated dose micronucleus assays of the liver using N-nitrosopyrrolidine: a report of the collaborative study by CSGMT/JEMS.MMS.

    Science.gov (United States)

    Ogawa, Izumi; Hagioa, Soichiro; Furukawa, Satoshi; Abe, Masayoshi; Kuroda, Yusuke; Hayashi, Seigo; Wako, Yumi; Kawasako, Kazufumi

    2015-03-01

    The repeated dose liver micronucleus (RDLMN) assay has the potential to detect liver carcinogens, and can be integrated into a general toxicological study. To assess the performance of the assay, N-nitrosopyrrolidine (NPYR), a genotoxic hepatocarcinogen, was tested in 14- or 28-day RDLMN assays. NPYR was orally administered to rats at a daily dose of 25, 50 or 100 mg/kg. One day after the last administration, a portion of the liver was removed and hepatocyte micronucleus (MN) specimens were prepared by the new method recently established by Narumi et al. In addition, a bone marrow MN assay and a histopathological examination of the liver were conducted. The detection of Phospho-Histone H3 was performed by immunohistochemistry to evaluate the proliferation rate of hepatocytes. The results showed significant increase in the number of micronucleated hepatocytes and Phospho-Histone H3-positive cells from the lowest dose in both 14- and 28-day RDLMN assays. On the other hand, the bone marrow MN assay yielded a negative result, which was in accordance with the existing report of the bone marrow MN assay using mice. Upon histopathological examination, inflammatory lesions and hypertrophy were noted, which may explain the increase in the hepatocyte proliferation and the enhancement of MN induction by NPYR. Our findings indicate that the RDLMN assay could be a useful tool for comprehensive risk assessment of carcinogenicity by providing information on both genotoxicity and histopathology when integrated into a general repeat dosing toxicity assay.

  12. Lack of genotoxic effect of food dyes amaranth, sunset yellow and tartrazine and their metabolites in the gut micronucleus assay in mice.

    Science.gov (United States)

    Poul, Martine; Jarry, Gérard; Elhkim, Mostafa Ould; Poul, Jean-Michel

    2009-02-01

    The food dyes amaranth, sunset yellow and tartrazine were administered twice, at 24h intervals, by oral gavage to mice and assessed in the in vivo gut micronucleus test for genotoxic effects (frequency of micronucleated cells) and toxicity (apoptotic and mitotic cells). The concentrations of each compound and their main metabolites (sulfanilic acid and naphthionic acid) were measured in faeces during a 24-h period after single oral administrations of the food dyes to mice. Parent dye compounds and their main aromatic amine metabolites were detected in significant amounts in the environment of colonic cells. Acute oral exposure to food dye additives amaranth, sunset yellow and tartrazine did not induce genotoxic effect in the micronucleus gut assay in mice at doses up to 2000 mg/kg b.w. Food dyes administration increased the mitotic cells at all dose levels when compared to controls. These results suggest that the transient DNA damages previously observed in the colon of mice treated by amaranth and tartrazine by the in vivo comet assay [Sasaki, Y.F., Kawaguchi, S., Kamaya, A., Ohshita, M., Kabasawa, K., Iwama, K., Taniguchi, K., Tsuda, S., 2002. The comet assay with 8 mouse organs: results with 39 currently used food additives. Mutat. Res. 519, 103-119] are unable to be fixed in stable genotoxic lesions and might be partly explained by local cytotoxicity of the dyes.

  13. Variability in micronucleus induction with different mutagens applied to several species of fish

    Directory of Open Access Journals (Sweden)

    Cesar Koppe Grisolia

    2000-03-01

    Full Text Available Fish are often used for screening genotoxicity of water. For such programs, a knowledge of the sensitivity to clastogens, spontaneous micronucleus frequency and cell cycle kinetics of the target tissue is necessary. To investigate the pattern of inter-specific sensitivity to micronucleus induction three species of fish, Tilapia rendalli, Oreochromis niloticus and Cyprinus carpio, were exposed to the clastogens bleomycin (BLM, cyclophosphamide (CP, 5-fluorouracil (5-FU, and mitomycin C (MMC. The binucleate/mononucleate ratio in peripheral erythrocytes exposed to cytochalasin B was also used to evaluate the time-dependent response of micronucleus formation during hematopoesis in the kidney and the micronucleus peak in peripheral erythrocytes. Micronucleus frequencies induced by CP were significantly greater than their respective controls for the three fish species throughout all treatment periods. During the whole evaluation period (30 days CP was also the most effective clastogen. In general, until the 14th day of evaluation period T. rendalii was the most sensitive species to clastogens. No difference in micronucleus frequencies among species was observed in the 4th evaluation (at the 30th day. A micronucleus peak was observed at the 7th day after treatment. After the 14th day the frequencies were stabilized. The cytochalasin B experiment was carried out to demonstrate that micronuclei induced in the young kidney erythrocyte cells were detected in the circulating blood 2-4 days later.Este estudo fez uma avaliação da indução de micronúcleos em eritrócitos de sangue periférico de peixes Tilapia rendalli, Oreochromis niloticus e Cyprinus carpio após o tratamento com mitomicina C, ciclofosfamida, 5-fluorouracil e bleomicina. Foram colhidas amostras periódicas de sangue com 2, 7, 14 e 30 dias após o tratamento único. Os tratamentos com citocalasina B tiveram como objetivo analisar as proporções entre células binucleadas

  14. Significance of micronucleus in cervical intraepithelial lesions and carcinoma

    Directory of Open Access Journals (Sweden)

    B N Gayathri

    2012-01-01

    Conclusions: MN scoring on the epithelial cells of cervix could be used as a biomarker in cancer screening. This is an easy, simple, reliable, reproducible and objective test which can be performed on routinely stained pap smears.

  15. Systemic complement activation in age-related macular degeneration.

    Directory of Open Access Journals (Sweden)

    Hendrik P N Scholl

    Full Text Available Dysregulation of the alternative pathway (AP of complement cascade has been implicated in the pathogenesis of age-related macular degeneration (AMD, the leading cause of blindness in the elderly. To further test the hypothesis that defective control of complement activation underlies AMD, parameters of complement activation in blood plasma were determined together with disease-associated genetic markers in AMD patients. Plasma concentrations of activation products C3d, Ba, C3a, C5a, SC5b-9, substrate proteins C3, C4, factor B and regulators factor H and factor D were quantified in patients (n = 112 and controls (n = 67. Subjects were analyzed for single nucleotide polymorphisms in factor H (CFH, factor B-C2 (BF-C2 and complement C3 (C3 genes which were previously found to be associated with AMD. All activation products, especially markers of chronic complement activation Ba and C3d (p<0.001, were significantly elevated in AMD patients compared to controls. Similar alterations were observed in factor D, but not in C3, C4 or factor H. Logistic regression analysis revealed better discriminative accuracy of a model that is based only on complement activation markers Ba, C3d and factor D compared to a model based on genetic markers of the complement system within our study population. In both the controls' and AMD patients' group, the protein markers of complement activation were correlated with CFH haplotypes.This study is the first to show systemic complement activation in AMD patients. This suggests that AMD is a systemic disease with local disease manifestation at the ageing macula. Furthermore, the data provide evidence for an association of systemic activation of the alternative complement pathway with genetic variants of CFH that were previously linked to AMD susceptibility.

  16. The Tradescantia micronucleus assay is a highly sensitive tool for the detection of low levels of radioactivity in environmental samples.

    Science.gov (United States)

    Mišík, Miroslav; Krupitza, Georg; Mišíková, Katarina; Mičieta, Karol; Nersesyan, Armen; Kundi, Michael; Knasmueller, Siegfried

    2016-12-01

    Environmental contamination with radioactive materials of geogenic and anthropogenic origin is a global problem. A variety of mutagenicity test procedures has been developed which enable the detection of DNA damage caused by ionizing radiation which plays a key role in the adverse effects caused by radioisotopes. In the present study, we investigated the usefulness of the Tradescantia micronucleus test (the most widely used plant based genotoxicity bioassay) for the detection of genetic damage caused by environmental samples and a human artifact (ceramic plate) which contained radioactive elements. We compared the results obtained with different exposure protocols and found that direct exposure of the inflorescences is more sensitive and that the number of micronuclei can be further increased under "wet" conditions. The lowest dose rate which caused a significant effect was 1.2 μGy/h (10 h). Comparisons with the results obtained with other systems (i.e. with mitotic cells of higher plants, molluscs, insects, fish and human lymphocytes) show that the Tradescantia MN assay is one to three orders of magnitude more sensitive as other models, which are currently available. Taken together, our findings indicate that this method is due to its high sensitivity a unique tool, which can be used for environmental biomonitoring in radiation polluted areas. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. The lectin pathway of complement

    DEFF Research Database (Denmark)

    Ballegaard, Vibe Cecilie Diederich; Haugaard, Anna Karen; Garred, P

    2014-01-01

    The pattern recognition molecules of the lectin complement pathway are important components of the innate immune system with known functions in host-virus interactions. This paper summarizes current knowledge of how these intriguing molecules, including mannose-binding lectin (MBL), Ficolin-1, -2......-1, -2 and -3 and CL-11 could have similar functions in HIV infection as the ficolins have been shown to play a role in other viral infections, and CL-11 resembles MBL and the ficolins in structure and binding capacity.......The pattern recognition molecules of the lectin complement pathway are important components of the innate immune system with known functions in host-virus interactions. This paper summarizes current knowledge of how these intriguing molecules, including mannose-binding lectin (MBL), Ficolin-1, -2...

  18. Complement's participation in acquired immunity

    DEFF Research Database (Denmark)

    Nielsen, Claus Henrik; Leslie, Robert Graham Quinton

    2002-01-01

    of the B cell receptor for antigen (BCR), a complex composed of the iC3b/C3d fragment-binding complement type 2 receptor (CR2, CD21) and its signaling element CD19 and the IgG-binding receptor FcgammaRIIb (CD32). The positive or negative outcome of signaling through this triad is determined by the context...

  19. Cytogenetic biomonitoring in petrol station attendants: A micronucleus study

    Directory of Open Access Journals (Sweden)

    Medhini Singaraju

    2012-01-01

    Conclusion: The MN test in exfoliated epithelial cells seems to be a useful biomarker of occupational exposure to genotoxic chemicals. Phenol is the principal metabolite of benzene. Therefore, phenol concentration in the urine of exposed workers can be used as a biomarker of external exposure.

  20. Study on ionizing radiation to the workers' lymphocyte micronucleus rate and chromosome aberrations

    International Nuclear Information System (INIS)

    Li Jianhua; Wang Linchao; He Wei

    2007-01-01

    Objective: To study lymphocyte genetic material of an iron and steel enterprise workers exposed to the ionizing radiation, find out measures to protect their health and reduce ionizing radiation occupation harm. Methods: 342 workers were choseh as the exposed group who worked in an iron and steel enterprise in the beam installment operation, to examine their circumference blood lymphocyte micronucleus rate and the chromosome aberrations, simultaneously select 280 chefs as the control group, The irradiation dosage was determined and statistical analysis was carded out wich the consideration of their length of work and differences in work post. Results: Exposed group: the micronucleus rate masculine gender (MNR), 4 people, the masculine gender pick out rate is 12.87%. The chromosome aberration factor masculine gender (CAF), 12 people, the masculine rate is 3.51%. Control group: MNR 3 people, the asculine gender pick out rate is 1.07%; CAF 2 people, masculine gender rate is 0.72%. Comparing the two groups, every item has the significant difference. Workers in is the exposed group workers have the average exposure dose of 6.73mSv/a, MNR,CAF are illuminated to the dosage have a positive line correlation. They become increased as the job lenght prolongs. The nucleon name, the material calculation and the medical X-radial are responsible for the highest ratio. Conclusion: In iron and steel enterprises, long-time ionizing radiation can cause the workers' circumference blood lymphocyte micronucleus rate and the chromosome aberrations obvious to rise. The beam protection measures strengthened so as to reduce the harms to workers. (authors)

  1. Nucleoplasmic bridges are a sensitive measure of chromosome rearrangement in the cytokinesis-block micronucleus assay

    International Nuclear Information System (INIS)

    Fenech, M.; Umegaki, K.

    2003-01-01

    Full text: We have performed experiments using the WIL2-NS human B-lymphoblastoid cell line and primary human lymphocytes to (a) determine the importance of including measurements of nucleoplasmic bridges (NPB) in the cytokinesis-block micronucleus (CBMN) assay and (b) provide evidence that NPB originate from dicentric chromosomes and centric ring chromosomes. In addition we describe theoretical models that explain how dicentric chromosomes and centric ring chromosomes may result in the formation of NPB at anaphase. The results with WIL2-NS showed that it was possible to distinguish genotoxic effects induced by different oxidizing agents in terms of the NPB/micronucleus frequency ratio. The results with lymphocytes indicated a strong correlation (a) between NPB, centric ring chromosomes and dicentric chromosomes in metaphases (R>0.93, P 0.93, P<0.0001). The dose-response curves with gamma rays were very similar for NPB, ring chromosomes and dicentric chromosomes, as were the dose-responses for MNi, acentric rings and fragments. However, not all acentric chromosomes and dicentric chromosomes/centric rings were converted to MNi and NPB respectively, depending on the dose of radiation. Preliminary data, using FISH, suggests that NPB often represent DNA from a structural rearrangement involving only one or two homologous chromosomes. The results from this study validate the inclusion of NPB in the CBMN assay which provides a valuable measure of chromosome breakage/ rearrangement that was otherwise not available in the micronucleus assay. The CBMN assay allows NPB measurement to be achieved reliably because inhibition of cytokinesis prevents the loss of NPB that would otherwise occur if cells were allowed to divide

  2. Biomonitoring air quality during and after a public transportation strike in the center of Uberlândia, Minas Gerais, Brazil by Tradescantia micronucleus bioassay.

    Science.gov (United States)

    Pereira, Boscolli Barbosa; de Campos, Edimar Olegário; de Lima, Euclides Antônio Pereira; Barrozo, Marcos Antonio Souza; Morelli, Sandra

    2014-03-01

    The aim of this study was to address the lack of information concerning the air quality in the city of Uberlândia, Minas Gerais, Brazil. In this study, we conducted an unprecedented experiment involving the in situ biomonitoring of air genotoxicity in the city center during and after a public transportation strike using the Tradescantia micronucleus test. The frequency of micronuclei was significantly higher in the city center compared with the reference site (Mann-Whitney test, p transport stoppage (Kruskal-Wallis, Dunn p transport stoppage and the increase in the concentration of particulate matter from the increased flow of vehicles in the city center during the strike positively influenced the MN frequency. The climatic factors did not change during the biomonitoring period, reflecting the fact that climatic factors did not influence the MN frequency.

  3. p53 protein expression versus micronucleus induction as an indicator of DNA damage

    International Nuclear Information System (INIS)

    Hickman, A.W.; Carpenter, T.R.; Johnson, N.F.

    1994-01-01

    In vitro assays for detecting DNA damage play an important role in evaluating the possible adverse health effects of chemical compounds. Exposure to many DNA-damaging agents in vitro has been shown to cause elevated levels of the tumor-suppressor protein p53. Work in our laboratory has shown that induction of the p53 protein is useful as a biodosimeter for determining the radiation dose to cells. The purpose of this investigation was to compare the sensitivity of this assay to that of micronucleus induction, which is commonly used as a marker of radiation-induced damage

  4. Antioxidant evaluation of heterocyclic compounds by cytokinesis-block micronucleus assay.

    Science.gov (United States)

    Godevac, Dejan; Tesević, Vele; Vajs, Vlatka; Milosavljević, Slobodan; Stanković, Miroslava

    2013-03-01

    This article summarizes the results of using cytokinesis-block micronucleus (CBMN) assay to evaluate the antioxidant potential of heterocyclic compounds. Most studies were carried out with naturally occurring heterocyclic compounds such as plant polyphenols: flavonoids, xanthones, coumarins, and ellagitannins, or plant derived products (juices, extracts, supplements) rich in bioactive heterocyclic compounds. There are also some studies dealing with synthetic heterocyclic antioxidants. CBMN assay is an in vitro study that has been used to evaluate antioxidant and protective effects of heterocyclic compounds on induced chromosome aberration in human lymphocytes.

  5. Patient exposure and micronucleus assay during extracorporeal shock wave lithotripsy (ESWL) for kidney stones

    International Nuclear Information System (INIS)

    Shao, M.

    1992-01-01

    This study reports results of radiation exposure to 20 patients with kidney stones during Extracorporeal Shock Wave Lithotripsy (ESWL). A domestically made JT-ESWL-I Lithotripter was used. Data indicated that the amount of radiation exposure is related to the numbers, size, location and radiodensity of the stone, and also the number of shock wave and the time of fluoroscopy exposure given to the patients. The results of the micronucleus frequency of lymphocytes assay in the human peripheral blood are reported. This effect increased with increasing radiation exposure doses. (author). 4 refs., 2 tabs

  6. Peptide Inhibitor of Complement C1 (PIC1 Rapidly Inhibits Complement Activation after Intravascular Injection in Rats.

    Directory of Open Access Journals (Sweden)

    Julia A Sharp

    Full Text Available The complement system has been increasingly recognized to play a pivotal role in a variety of inflammatory and autoimmune diseases. Consequently, therapeutic modulators of the classical, lectin and alternative pathways of the complement system are currently in pre-clinical and clinical development. Our laboratory has identified a peptide that specifically inhibits the classical and lectin pathways of complement and is referred to as Peptide Inhibitor of Complement C1 (PIC1. In this study, we determined that the lead PIC1 variant demonstrates a salt-dependent binding to C1q, the initiator molecule of the classical pathway. Additionally, this peptide bound to the lectin pathway initiator molecule MBL as well as the ficolins H, M and L, suggesting a common mechanism of PIC1 inhibitory activity occurs via binding to the collagen-like tails of these collectin molecules. We further analyzed the effect of arginine and glutamic acid residue substitution on the complement inhibitory activity of our lead derivative in a hemolytic assay and found that the original sequence demonstrated superior inhibitory activity. To improve upon the solubility of the lead derivative, a pegylated, water soluble variant was developed, structurally characterized and demonstrated to inhibit complement activation in mouse plasma, as well as rat, non-human primate and human serum in vitro. After intravenous injection in rats, the pegylated derivative inhibited complement activation in the blood by 90% after 30 seconds, demonstrating extremely rapid function. Additionally, no adverse toxicological effects were observed in limited testing. Together these results show that PIC1 rapidly inhibits classical complement activation in vitro and in vivo and is functional for a variety of animal species, suggesting its utility in animal models of classical complement-mediated diseases.

  7. Subversion of complement by hematophagous parasites

    OpenAIRE

    Schroeder, Hélène; Skelly, Patrick; Zipfel, Peter F.; Losson, Bertrand; Vanderplasschen, Alain

    2009-01-01

    The complement system is a crucial part of innate and adaptive immunity which exerts a significant evolutionary pressure on pathogens. It has selected for those pathogens, mainly micro-organisms but also parasites, that have evolved countermeasures. The characterization of how pathogens evade complement attack is a rapidly developing field of current research. In recent years, multiple complement evasion strategies have been characterized. In this review, we focus on complement escape mechani...

  8. Xenodiagnostico, hemocultura e teste de lise mediada pelo complemento, como critérios de seleção de pacientes chagásicos crônicos para quimioterapia Xenodiagnosis, hemoculture and complement mediated lysis tests as criteria for selection of chronic chagasic patients for chemotherapy

    Directory of Open Access Journals (Sweden)

    Vera Lúcia Pereira

    1989-10-01

    Full Text Available O tratamento etiológico da doença de Chagas é iniciado geralmente apenas quando se dispõe de um diagnóstico parasitológico positivo. Na tentativa de aumentar o número de candidatos assim selecionados para o tratamento específico, estudamos 36 pacientes chagásicos crônicos associando o xenodiagnóstico, a hemocultura e o teste de lise mediada pelo complemento, em duas séries sucessivas, intercaladas de um mínimo de 60 dias. A sensibilidade do xenodiagnóstico e da hemocultura foi respectivamente de 30,5% e de 8,3% na primeira série e de 36,1% e de 19,4% nas duas séries. Foram positivos, em pelo menos uma das duas provas, 17 (47,2% dos pacientes. Destes, entretanto, somente 9 (53,0% mostraram teste de lise constantemente positivo enquanto que em 5 (29,4% o teste foi negativo e 3 (17,6% apresentaram resultados ora positivos, ora negativos. Nos pacientes com provas parasitológicas negativas, o teste de lise foi positivo em 4 (15,8%, negativo em 9 (47,4% e discordante em 6 (31,5%. Assim, o teste de lise mediada pelo complemento não se constitue em bom método de triagem de candidatos ao tratamento. Apesar da baixa sensibilidade, as provas parasitológicas ainda constituem o instrumento mais seguro para o clínico.Normally specific treatment of chronic Chagas' disease begins only after a positive parasitological diagnosis has been established. Xenodiagnosis, hemoculture and complement mediated lysis were associated, and repeated, as an attempt to increase the number of selected candidates for specific treatment. Thirty six chronic chagasic patients were submitted to two series of the above tests, with a minimal interval of 60 days. In the first series of tests sensitivity of xenodiagnosis and hemoculture were 30.5% and 8.3% respectively. Processing of a second sample increased sensitivity to 36.1% (xenodiagnosis and 19.4% (hemoculture; 47.2% were shown to be positive by at least one of these tests. From the positive cases, 29.4% were

  9. conformational complexity of complement component C3

    NARCIS (Netherlands)

    Janssen, B.J.C.

    2007-01-01

    The complement system is an important part of the immune system and critical for the elimination of pathogens. In mammals the complement system consists of an intricate set of about 35 soluble and cell-surface plasma proteins. Central to complement is component C3, a large protein of 1,641 residues.

  10. Complement activation and inhibition: a delicate balance

    DEFF Research Database (Denmark)

    Sjöberg, A P; Trouw, L A; Blom, A M

    2009-01-01

    proteins, pentraxins, amyloid deposits, prions and DNA, all bind the complement activator C1q, but also interact with complement inhibitors C4b-binding protein and factor H. This contrasts to the interaction between C1q and immune complexes, in which case no inhibitors bind, resulting in full complement...

  11. Comparison of micronucleus frequencies and proliferation kinetics in three X-irradiated cell lines

    International Nuclear Information System (INIS)

    Kaffenberger, W.; Becker, K.; Beuningen, D. van

    1990-01-01

    The kinetics of the occurrence of micronuclei was correlated with the survival of three mammalian cell lines of human, monkey, and mouse origin after irradiation with 240 kV X-rays. Particular attention was paid to the evaluation of the individual proliferation kinetics of the cell lines as well as to the characterization of micronuclei subpopulation with respect to size and possible biological importance using DNA and BUdR labelling techniques, fluorescence microscopy, and image analysis. The results demonstrate very characteristic size distributions of micronuclei for the three cell lines independent of radiation dose and time after irradiation. A close correlation between cell death and the occurrence of micronuclei (expressed as a calculated 'MN index') after irradiation could be established only when the kinetics of progression of cells through the cell cycle (e.g. the doubling time) and the biological characteristics of micronuclei (e.g. BUdR positivity, the micronucleus frequencies, and the number of micronuclei per main nucleus) were taken into account. Therefore, the micronucleus assay might not be useful as a quantitative perdictive assay in vivo but may allow qualitative estimations of radiation damage only because the necessary proliferation parameters of the cells might not be possible to establish in vivo. (orig.) [de

  12. Effects of estradiol and progesterone on the variability of the micronucleus assay

    International Nuclear Information System (INIS)

    Baeyens, Ans; Vandersickel, Veerle; Thierens, Hubert; Ridder, Leo De; Vral, Anne

    2005-01-01

    To investigate chromosomal radiosensitivity of lymphocytes the micronucleus (MN) assay has been used for many years. The results of these studies suggest the use of the MN assay as a biomarker for cancer predisposition. However, the MN assay has still some limitations associated with the reproducibility and sensitivity. Especially a high intra-individual variability has been observed. An explanation for this high intra-individual variability is not yet available. In literature it is suggested that the high variability among females is attributable to hormonal status. In this study we investigated if the high intra-individual variability in micronucleus formation in lymphocytes of females after in vitro exposure to ionising radiation is caused by variations in hormone levels of estradiol (E2) and progesterone (PROG). For this, the MN assay was performed on blood samples of 18 healthy women during 7 consecutive weeks while the estradiol and progesterone levels were determined at the same time. The MN assay was also examined in cultures of isolated blood lymphocytes with estradiol or progesterone levels added in vitro. The results demonstrated that estradiol and progesterone levels have no influence on the variations in radiation-induced MN yields observed in blood samples of healthy women. These conclusions were confirmed by the 'in vitro' experiments as no correlation between the MN yields and the concentrations of hormones (estradiol or progesterone) added in vitro to isolated lymphocytes cultures was observed

  13. Flow cytometry based micronucleus assay for evaluation of genotoxic potential of 2-ACBs in hepatic cells HepG2

    International Nuclear Information System (INIS)

    Barbezan, Angélica B.; Santos, Carla J.B.; Carvalho, Luma R.; Vieira, Daniel P.; Villavicêncio, Anna L.C.H.; Santelli, Glaucia M.M.

    2017-01-01

    Food irradiation is approved for use in more than 60 countries for applications and purposes in a wide variety of foods, being an effective and safe method for preservation and long-term storage. 2-Alkylcyclobutanones (2-ACBs) are the only known radiolytic products generated from foods that contain fatty acids (Triglycerides) when irradiated. The acids analyzed in this study are palmitic and stearic, which when irradiated form 2-Dodecylcyclobutanones (2-dDCB) and 2-Tetradecylcyclobutanone (2-tDCB). Part of the 2-ACBs ingested is excreted through feces and part is deposited in adipose tissues. In vitro studies so far have been only in colon cells. The work used a human hepatoma cell line (HepG2) since the accumulation of fat in this organ is quite common. Micronucleus test was selected to evaluate possible genotoxic effects of 2-dDCB and 2-tDCB compounds when exposed to high concentrations (447, 1422 and 2235 μM) for 4 and 24 hours. Tests were performed in quadriplicates using flow cytometric analysis. None detectable genotoxic damage was observed after 4 hours of exposure to the compounds, and cytotoxic effects were only significant at the highest concentration (2235 μM) of 2-dDCB. After 24 hours of exposure, slight genotoxic damage was observed at all concentrations evaluated, and cytotoxic effects were only present when exposed to compound 2-tDCB. Although there is a genotoxic and cytotoxic effect in some of the situations tested, the two compounds predominantly induced proliferation reduction effects of this hepatic tumor cell line. (author)

  14. Dose-Response Assessment of Four Genotoxic Chemicals in a Combined Mouse and Rat Micronucleus and Comet Assay Protocol

    Science.gov (United States)

    Recio, Leslie; Hobbs, Cheryl; Caspary, William; Witt, Kristine L.

    2012-01-01

    The in vivo micronucleus (MN) assay has proven to be an effective measure of genotoxicity potential. However, sampling a single tissue (bone marrow) for a single indicator of genetic damage using the MN assay provides a limited genotoxicity profile. The in vivo alkaline (pH>13) Comet assay, which detects a broad spectrum of DNA damage, can be applied to a variety of rodent tissues following administration of test agents. To determine if the Comet assay is a useful supplement to the in vivo MN assay, a combined test protocol (MN/Comet assay) was conducted in male B6C3F1 mice and F344/N rats using four model genotoxicants: ethyl methanesulfonate (EMS), acrylamide (ACM), cyclophosphamide (CP), and vincristine sulfate (VS). Test compounds were administered on 4 consecutive days at 24-hour intervals (VS was administered to rats for 3 days); animals were euthanized 4 hours after the last administration. All compounds induced significant increases in micronucleated reticulocytes (MN-RET) in the peripheral blood of mice, and all but ACM induced MN-RET in rats. EMS and ACM induced significant increases in DNA damage, measured by the Comet assay, in multiple tissues of mice and rats. CP-induced DNA damage was detected in leukocytes and duodenum cells. VS, a spindle fiber disrupting agent, was negative in the Comet assay. Based on these results, the MN/Comet assay holds promise for providing more comprehensive assessments of potential genotoxicants, and the National Toxicology Program is presently using this combined protocol in its overall evaluation of the genotoxicity of substances of public health concern. PMID:20371966

  15. Genotoxicity of Heterocyclic PAHs in the Micronucleus Assay with the Fish Liver Cell Line RTL-W1

    Science.gov (United States)

    Brinkmann, Markus; Blenkle, Henning; Salowsky, Helena; Bluhm, Kerstin; Schiwy, Sabrina; Tiehm, Andreas; Hollert, Henner

    2014-01-01

    Heterocyclic aromatic hydrocarbons are, together with their un-substituted analogues, widely distributed throughout all environmental compartments. While fate and effects of homocyclic PAHs are well-understood, there are still data gaps concerning the ecotoxicology of heterocyclic PAHs: Only few publications are available investigating these substances using in vitro bioassays. Here, we present a study focusing on the identification and quantification of clastogenic and aneugenic effects in the micronucleus assay with the fish liver cell line RTL-W1 that was originally derived from rainbow trout (Oncorhynchus mykiss). Real concentrations of the test items after incubation without cells were determined to assess chemical losses due to, e.g., sorption or volatilization, by means of gas chromatography-mass spectrometry. We were able to show genotoxic effects for six compounds that have not been reported in vertebrate systems before. Out of the tested substances, 2,3-dimethylbenzofuran, benzothiophene, quinoline and 6-methylquinoline did not cause substantial induction of micronuclei in the cell line. Acridine caused the highest absolute induction. Carbazole, acridine and dibenzothiophene were the most potent substances compared with 4-nitroquinoline oxide, a well characterized genotoxicant with high potency used as standard. Dibenzofuran was positive in our investigation and tested negative before in a mammalian system. Chemical losses during incubation ranged from 29.3% (acridine) to 91.7% (benzofuran) and may be a confounding factor in studies without chemical analyses, leading to an underestimation of the real potency. The relative potency of the investigated substances was high compared with their un-substituted PAH analogues, only the latter being typically monitored as priority or indicator pollutants. Hetero-PAHs are widely distributed in the environment and even more mobile, e.g. in ground water, than homocyclic PAHs due to the higher water solubility. We

  16. Flow cytometry based micronucleus assay for evaluation of genotoxic potential of 2-ACBs in hepatic cells HepG2

    Energy Technology Data Exchange (ETDEWEB)

    Barbezan, Angélica B.; Santos, Carla J.B.; Carvalho, Luma R.; Vieira, Daniel P.; Villavicêncio, Anna L.C.H., E-mail: abarbezan@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil); Santelli, Glaucia M.M. [Universidade de São Paulo (USP), SP (Brazil). Departamento de Biologia Celular e do Desenvolvimento

    2017-07-01

    Food irradiation is approved for use in more than 60 countries for applications and purposes in a wide variety of foods, being an effective and safe method for preservation and long-term storage. 2-Alkylcyclobutanones (2-ACBs) are the only known radiolytic products generated from foods that contain fatty acids (Triglycerides) when irradiated. The acids analyzed in this study are palmitic and stearic, which when irradiated form 2-Dodecylcyclobutanones (2-dDCB) and 2-Tetradecylcyclobutanone (2-tDCB). Part of the 2-ACBs ingested is excreted through feces and part is deposited in adipose tissues. In vitro studies so far have been only in colon cells. The work used a human hepatoma cell line (HepG2) since the accumulation of fat in this organ is quite common. Micronucleus test was selected to evaluate possible genotoxic effects of 2-dDCB and 2-tDCB compounds when exposed to high concentrations (447, 1422 and 2235 μM) for 4 and 24 hours. Tests were performed in quadriplicates using flow cytometric analysis. None detectable genotoxic damage was observed after 4 hours of exposure to the compounds, and cytotoxic effects were only significant at the highest concentration (2235 μM) of 2-dDCB. After 24 hours of exposure, slight genotoxic damage was observed at all concentrations evaluated, and cytotoxic effects were only present when exposed to compound 2-tDCB. Although there is a genotoxic and cytotoxic effect in some of the situations tested, the two compounds predominantly induced proliferation reduction effects of this hepatic tumor cell line. (author)

  17. Genotoxicity of heterocyclic PAHs in the micronucleus assay with the fish liver cell line RTL-W1.

    Directory of Open Access Journals (Sweden)

    Markus Brinkmann

    Full Text Available Heterocyclic aromatic hydrocarbons are, together with their un-substituted analogues, widely distributed throughout all environmental compartments. While fate and effects of homocyclic PAHs are well-understood, there are still data gaps concerning the ecotoxicology of heterocyclic PAHs: Only few publications are available investigating these substances using in vitro bioassays. Here, we present a study focusing on the identification and quantification of clastogenic and aneugenic effects in the micronucleus assay with the fish liver cell line RTL-W1 that was originally derived from rainbow trout (Oncorhynchus mykiss. Real concentrations of the test items after incubation without cells were determined to assess chemical losses due to, e.g., sorption or volatilization, by means of gas chromatography-mass spectrometry. We were able to show genotoxic effects for six compounds that have not been reported in vertebrate systems before. Out of the tested substances, 2,3-dimethylbenzofuran, benzothiophene, quinoline and 6-methylquinoline did not cause substantial induction of micronuclei in the cell line. Acridine caused the highest absolute induction. Carbazole, acridine and dibenzothiophene were the most potent substances compared with 4-nitroquinoline oxide, a well characterized genotoxicant with high potency used as standard. Dibenzofuran was positive in our investigation and tested negative before in a mammalian system. Chemical losses during incubation ranged from 29.3% (acridine to 91.7% (benzofuran and may be a confounding factor in studies without chemical analyses, leading to an underestimation of the real potency. The relative potency of the investigated substances was high compared with their un-substituted PAH analogues, only the latter being typically monitored as priority or indicator pollutants. Hetero-PAHs are widely distributed in the environment and even more mobile, e.g. in ground water, than homocyclic PAHs due to the higher water

  18. Complement Activation in Inflammatory Skin Diseases

    Directory of Open Access Journals (Sweden)

    Jenny Giang

    2018-04-01

    Full Text Available The complement system is a fundamental part of the innate immune system, playing a crucial role in host defense against various pathogens, such as bacteria, viruses, and fungi. Activation of complement results in production of several molecules mediating chemotaxis, opsonization, and mast cell degranulation, which can contribute to the elimination of pathogenic organisms and inflammation. Furthermore, the complement system also has regulating properties in inflammatory and immune responses. Complement activity in diseases is rather complex and may involve both aberrant expression of complement and genetic deficiencies of complement components or regulators. The skin represents an active immune organ with complex interactions between cellular components and various mediators. Complement involvement has been associated with several skin diseases, such as psoriasis, lupus erythematosus, cutaneous vasculitis, urticaria, and bullous dermatoses. Several triggers including auto-antibodies and micro-organisms can activate complement, while on the other hand complement deficiencies can contribute to impaired immune complex clearance, leading to disease. This review provides an overview of the role of complement in inflammatory skin diseases and discusses complement factors as potential new targets for therapeutic intervention.

  19. Alkaline comet assay in liver and stomach, and micronucleus assay in bone marrow, from rats treated with 2-acetylaminofluorene, azidothymidine, cisplatin, or isobutyraldehyde.

    Science.gov (United States)

    Kraynak, A R; Barnum, J E; Cunningham, C L; Ng, A; Ykoruk, B A; Bennet, B; Stoffregen, D; Merschman, M; Freeland, E; Galloway, S M

    2015-07-01

    As part of the Japanese Center for the Validation of Alternative Methods (JaCVAM) initiative international validation study of the in vivo rat alkaline comet assay (comet assay), we examined the ability of the assay to determine the genotoxicity of 2-acetylaminofluorene (AAF), azidothymidine (AZT), cisplatin (CPN), and isobutyraldehyde (IBA) in liver and glandular stomach of male Sprague-Dawley rats. Rats were given oral doses of test compound or control once daily for three days. High dose levels were approximately maximum tolerated doses and were based on preliminary range-finding studies. Tissues were harvested 3h after the final dose (48h after the initial dose). A bone marrow micronucleus assay (MN) was also conducted on the rats treated with AZT, CPN, and IBA. Acute toxic effects of treatment were determined primarily through histomorphologic analysis of liver and stomach but also by body weight and serum liver enzyme changes. The comet assay was conducted on fresh tissue preparations but frozen samples from two studies were also assayed. Statistically significant dose-related differences in comet % DNA in tail were found in liver and stomach for the genotoxin AZT and in liver for the genotoxin CPN, but not in liver or stomach for the non-genotoxin IBA. Statistically significant differences in % DNA in tail were measured in liver for the low and mid dose of the genotoxin AAF, but not the high dose. The comet assays of frozen liver suspensions from CPN- and AAF-treated rats yielded comparable results to the assays of fresh preparations. There were no indications of significant toxicity induced by any treatment. The micronucleus assay was positive for CPN and AZT and negative for IBA. In conclusion, the in vivo comet assay is capable of detecting genotoxic effects of a variety of chemicals and may fill an important role in the genotoxicity test battery. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Micronucleus induction and reproductive death in a human cell line exposed to low-energy argon beam

    International Nuclear Information System (INIS)

    Courdi, A.; Mari, D.; Herault, J.; Chauvel, P.

    1995-01-01

    The aim of this study was to measure the biological efficiency of a low-energy argon beam (E=7.1 MeV/nucleon, LET=1590 keV/μm) on a human melanoma cell line (CAL4) established in our Institute. Two different methods were used: the micronucleus (MN) test and the colony-forming assay. MN are scored in binucleate cells (BNC) and are formed from acentric fragments or whole chromosomes that have not been incorporated into daughter nuclei at mitosis. The colony-forming assay quantifies reproductive death. Parallel experiments were run with cobalt gamma-rays for comparison. After Co irradiation, the MN-free BNC dose-response curve coincided with that of the loss of colony-forming ability, suggesting the potential of the former as a predictive test of cell killing. After Ar irradiation, there was a dissociation between the two effects, especially at high doses: cell death was greater than the frequency of BNC with MN. The inactivation cross-section was 74 μm 2 ; it was 39 μm 2 for MN yield. Therefore, the relative biological effectiveness (RBE) was higher for cell killing than for MN yield (0.8 and 0.5, respectively, at a Co dose of 3 Gy). The total MN count in BNC followed the same pattern of response as the fraction of BNC with MN. However, multiple (>2) MN in BNC were more frequently observed after low-dose Ar irradiation than after gamma-ray exposure (RBE > 1). Moreover, the frequency of multiple MN induction exceeded that expected from a Poisson distribution at all dose levels of Ar irradiation. (orig.)

  1. Combined cytokinesis-block micronucleus and chromosomal aberration assay for the evaluation of radiosensitizers at low radiation doses

    International Nuclear Information System (INIS)

    Oya, Natsuo; Shibamoto, Yuta; Shibata, Toru

    1994-01-01

    Several methods have been tried for evaluating the efficacy of hypoxic cell radiosensitizers at clinically relevant low radiation doses (1-4 Gy). The cytokinesis-block micronucleus assay is known to be useful for both the in vitro and in vivo evaluation of radiosensitizers, while the chromosomal aberration assay has been commonly used to assess the mutagenicity of various agents. In the present study, the chromosomal aberration assay and the cytokinesis-block micronucleus assay were performed simultaneously to assess the radiosensitizing effect of etanidazole and KU-2285 at low radiation doses. The correlation between the two assays was also evaluated. In vitro study: EMT-6 cells were irradiated at a dose of 1-3 Gy under hypoxic conditions with or without the drugs at 1 mM. In vivo-in vitro study: EMT-6 tumor-bearing BALB/c mice received 2-4 Gy of radiation with or without administration of the drugs at 200 mg/kg. Single-cell suspensions were then obtained in both studies and were used for the cytokinesis-block micronucleus assay and the chromosomal aberration assay. The micronucleus frequency in binucleate cells was evaluated in the former assay, and the frequency of chromosomal aberrations in metaphase cells was evaluated in the latter assay. In vitro study: the sensitizer enhancement ratios of etanidazole and KU-2285 were 1.73 and 2.21, respectively, in the micronucleus assay, and 1.41 and 1.79 in the chromosomal aberration assay. In vivo-in vitro study: the sensitizer enhancement ratios of etanidazole and KU-2285 were 1.18 and 1.31, respectively, in the micronucleus assay, and 1.16 and 1.42 in the chromosomal aberration assay. In both studies, a linear correlation was observed between the micronucleus frequency and the chromosomal aberration frequency. The background (i.e., the frequency at 0 Gy) of the latter assay was considerably lower than that of the former assay, especially in the in vivo study. 31 refs., 4 figs

  2. Does the recommended lymphocyte cytokinesis-block micronucleus assay for human biomonitoring actually detect DNA damage induced by occupational and environmental exposure to genotoxic chemicals?

    Science.gov (United States)

    Speit, Günter

    2013-07-01

    This commentary challenges the paradigm that the cytokinesis-block micronucleus assay (CBMN assay) with cultured human lymphocytes, as it is performed currently, is a sensitive and useful tool for detecting genotoxic effects in populations exposed occupationally or environmentally to genotoxic chemicals. Based on the principle of the assay and the available data, increased micronucleus (MN) frequencies in binucleated cells (BNC) are mainly due to MN produced in vitro during the cultivation period (i.e. MN produced in vivo do not substantially contribute to the MN frequency measured in BNC). The sensitivity of the assay for the detection of induced MN in BNC after an in vivo exposure to a genotoxic chemical is limited because cytochalasin B (Cyt-B) is added relatively late during the culture period and, therefore, the BNC that are scored do not always represent cells that have completed one cell cycle only. Furthermore, this delay means that damaged cells can be eliminated by apoptosis and/or that DNA damage induced in vivo can be repaired prior to the production of a MN in the presence of Cyt-B. A comparison with the in vitro CBMN assay used for genotoxicity testing leads to the conclusion that it is highly unlikely that DNA damage induced in vivo is the cause for increased MN frequencies in BNC after occupational or environmental exposure to genotoxic chemicals. This commentary casts doubt on the usefulness of the CBMN assay as an indicator of genotoxicity in human biomonitoring and questions the relevance of many published data for hazard identification and risk assessment. Thus, it seems worthwhile to reconsider the use of the CBMN assay as presently conducted for the detection of genotoxic exposure in human biomonitoring.

  3. Complement and hyper acute rejection

    Directory of Open Access Journals (Sweden)

    Al-Rabia Mohammed

    2009-01-01

    Full Text Available Organ transplantation has been a major development in clinical medicine but its success has been marred by the immune system′s capacity to respond to "non-self" cells and tissues. A full molecular understanding of this mechanism and the myriad triggers for immune rejection is yet to be elucidated. Consequently, immunosuppressive drugs remain the mainstay of post-transplant ma-nagement; however, these interventions have side effects such as increased incidence of cancer, post-transplant lymphoproliferative disorders, susceptibility to infection if not managed appro-priately and the inconvenience to the patient of lifelong treatment. Novel therapeutic approaches based on molecular understanding of immunological processes are thus needed in this field. The notion that factors influencing successful transplants might be of use as therapeutic approaches is both scientifically and medically appealing. Recent developments in the understanding of successful transplants are expected to provide new opportunities for safer transplantation. This article reviews the present understanding of the molecular basis of rejection and the role of complement in this process as well as the possibility of generating "intelligent" therapy that better target crucial components of hyper-acute rejections.

  4. Subversion of complement by hematophagous parasites.

    Science.gov (United States)

    Schroeder, Hélène; Skelly, Patrick J; Zipfel, Peter F; Losson, Bertrand; Vanderplasschen, Alain

    2009-01-01

    The complement system is a crucial part of innate and adaptive immunity which exerts a significant evolutionary pressure on pathogens. It has selected for those pathogens, mainly microorganisms but also parasites, that have evolved countermeasures. The characterization of how pathogens evade complement attack is a rapidly developing field of current research. In recent years, multiple complement evasion strategies have been characterized. In this review, we focus on complement escape mechanisms expressed by hematophagous parasites, a heterogeneous group of metazoan parasites that share the property of ingesting the whole blood of their host. Complement inhibition is crucial for parasite survival within the host tissue or to facilitate blood feeding. Finally, complement inhibition by hematophagous parasites may also contribute to their success as pathogen vectors.

  5. Evidence of heritable lethal mutations in progeny of X-irradiated CHO cells by micronucleus count in clon-cells

    International Nuclear Information System (INIS)

    Hagemann, G.; Kreczik, A.; Treichel, M.

    1996-01-01

    Low doses of ionizing radiation reduce the growth rates of clones following irradiation of the progenitor cells. Such reductions of clone growth have been proven by means of measurements of clone size distributions. The medians of such distributions can be used to quantify the radiation damage. Prolongations of generation times and cell death as result of heritable lethal mutations have been discussed as causes for the reduction of clone growth. The cell number of a clone of hypotetraploid CHO-cells was compared to the frequency of micronucleated binucleated cells in the same clone using the cytokinesis-block-micronucleus method. The dose dependent reduction of clone sizes is measured by the difference of the medians (after log transformation) of the clone size distributions. At cytochalasin-B concentrations of 1 μg/ml and after an incubation time of 16 h a yield of binucleated cells of about 50% was obtained. Median clone size differences as a measure of clonal radiation damage increased linearly with incubation times of 76, 100, 124, and 240 h following irradiation with 3, 5, 7, and 12 Gy. The frequency of binucleated clone cells with micronuclei strongly increased with decreasing clone size by a factor up to 20 following irradiation with 3, 5, and 7 Gy. The frequency of micronucleated binucleated clone cells was found to be independent of incubation time after irradiation. Radiation induced clone size reductions result from cell losses caused by intraclonal expression of micronuclei which have its origin in heritable lethal mutations. Measurements of clone size distributions can be done automatically. They can serve as predictive test for determination of median cell loss rates of surviving cell clones. (orig./MG) [de

  6. Increased micronucleus, nucleoplasmic bridge, and nuclear bud frequencies in the peripheral blood lymphocytes of diesel engine exhaust-exposed workers.

    Science.gov (United States)

    Zhang, Xiao; Duan, Huawei; Gao, Feng; Li, Yuanyuan; Huang, Chuanfeng; Niu, Yong; Gao, Weimin; Yu, Shanfa; Zheng, Yuxin

    2015-02-01

    The International Agency for Research on Cancer has recently reclassified diesel engine exhaust (DEE) as a Group 1 carcinogen. Micronucleus (MN), nucleoplasmic bridge (NPB), and nuclear bud (NBUD) frequencies in peripheral blood lymphocytes (PBLs) are associated with cancer risk. However, the impact of DEE exposure on MN frequency has not been thoroughly elucidated due to mixed exposure and its impact on NPB and NBUD frequencies has never been explored in humans. We recruited 117 diesel engine testing workers with exclusive exposure to DEE and 112 non-DEE-exposed workers, and then we measured urinary levels of 4 mono-hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) using high-performance liquid chromatography-mass spectrometry as well as MN, NPB, and NBUD frequencies in PBLs using cytokinesis-block MN assay. The DEE-exposed workers exhibited significantly higher MN, NPB, and NBUD frequencies than the non-DEE-exposed workers (P < 0.05). Among all study subjects, increasing levels of all 4 urinary OH-PAHs, on both quartile and continuous scales, were associated with increased MN, NPB, and NBUD frequencies (all P < 0.05). When the associations were analyzed separately in DEE-exposed and non-DEE-exposed workers, we found that the association between increasing quartiles of urinary 9-hydroxyphenanthrene (9-OHPh) and MN frequencies persisted in DEE-exposed workers (P = 0.001). The percent of MN frequencies increased, on average, by 23.99% (95% confidential interval, 9.64-39.93) per 1-unit increase in ln-transformed 9-OHPh. Our results clearly show that exposure to DEE can induce increases in MN, NPB, and NBUD frequencies in PBLs and suggest that DEE exposure level is associated with MN frequencies. © The Author 2014. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  7. Micronucleus frequency in Danish schoolchildren and their mothers from the DEMOCOPHES population

    DEFF Research Database (Denmark)

    Mørck, Thit A.; Vande Loock, Kim; Poulsen, Maria Bech

    2016-01-01

    organic pollutants and dioxin-like activity measured in the sameparticipants. The MN frequency analysis was performed with the cytokinesis-block micronucleus(CBMN) assay and included 100 children and 119 mothers. We found a significant correlationbetween mothers and children in the levels of micronuclei...... in 1000 binucleated T lymphocytes(‰MNBN) and in the proliferation index. Further the levels of ‰MNBN were significantly higherin mothers compared with their children. No significant associations were found for ‰MNBNfor traffic related exposure in neither children nor their mothers. In children, a 2.......5 times highermicronuclei in mononuclear T lymphocytes were found in children living within 50 m of a busyroad, however, this was not found in mothers or in MNBN and the effect of exposure to road trafficon MN frequency needs further investigation. No significant associations were found between...

  8. Genotoxicity and ELF-magnetic fields: a review through the micronucleus assay

    International Nuclear Information System (INIS)

    Alcaraz, M.; Andreu-Galvez, M.; Sanchez-Villalobos, J. M.; Achel, D. G.; Olmos, E.; Martinez-Hernandez, C. M.

    2012-01-01

    Thirty for (34) published studies, conducted from 1994 to the present to evaluate the genotoxic effect of magnetic fields using ELF-EMF and diagnostic resonance on humans by the micronucleus assay have been reviewed. some characteristics of the assay methods, their significance to genotoxicity and basic interpretations of the results of these assays are discussed. of the studies analysed 70.5% implicated genotoxic effects induced by these magnetic fields: 52.9% were due to exposure to magnetic fields only and 17,6% by exposure to magnetic fields in combination with some treatment types, resulting in additive or synergistic effect. Evidence exist to support the notion that exposure of humans to magnetic fields stimulates genotoxic effects, although the actual mechanisms of action or even the true human health consequences resulting from these exposure still remain unclear. (Author) 80 refs.

  9. Complement anaphylatoxins as immune regulators in cancer

    OpenAIRE

    Sayegh, Eli T; Bloch, Orin; Parsa, Andrew T

    2014-01-01

    The role of the complement system in innate immunity is well characterized. However, a recent body of research implicates the complement anaphylatoxins C3a and C5a as insidious propagators of tumor growth and progression. It is now recognized that certain tumors elaborate C3a and C5a and that complement, as a mediator of chronic inflammation and regulator of immune function, may in fact foster rather than defend against tumor growth. A putative mechanism for this function is complement-mediat...

  10. Complement anaphylatoxins as immune regulators in cancer.

    Science.gov (United States)

    Sayegh, Eli T; Bloch, Orin; Parsa, Andrew T

    2014-08-01

    The role of the complement system in innate immunity is well characterized. However, a recent body of research implicates the complement anaphylatoxins C3a and C5a as insidious propagators of tumor growth and progression. It is now recognized that certain tumors elaborate C3a and C5a and that complement, as a mediator of chronic inflammation and regulator of immune function, may in fact foster rather than defend against tumor growth. A putative mechanism for this function is complement-mediated suppression of immune effector cells responsible for immunosurveillance within the tumor microenvironment. This paradigm accords with models of immune dysregulation, such as autoimmunity and infectious disease, which have defined a pathophysiological role for abnormal complement signaling. Several types of immune cells express the cognate receptors for the complement anaphylatoxins, C3aR and C5aR, and demonstrate functional modulation in response to complement stimulation. In turn, impairment of antitumor immunity has been intimately tied to tumor progression in animal models of cancer. In this article, the literature was systematically reviewed to identify studies that have characterized the effects of the complement anaphylatoxins on the composition and function of immune cells within the tumor microenvironment. The search identified six studies based upon models of lymphoma and ovarian, cervical, lung, breast, and mammary cancer, which collectively support the paradigm of complement as an immune regulator in the tumor microenvironment. © 2014 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  11. Use of micronucleus test in evaluating radioprotective action of mixed tremella preparation

    International Nuclear Information System (INIS)

    Lu Jiaben; Huang Yinmei; Zhu Bingchai

    1993-01-01

    The radioprotective action of mixed tremella preparation (Yinshen Yin) on whole body gamma irradiated dogs has been studied. 25 male dogs were divided into five groups: tremella, mercaminum, Yinshen Yin at high dose, Yinshen Yin at low dose and control. All the dogs were given above drugs in 10 successive days before acute exposure of 1 Gy radiation. The results showed that the prophylactic use of Yinshen Yin had good anti-irradiation effect, and the radioprotective effect was similar to the mercaminum, but significantly higher than tremella. Thereby it was considered as a good radioprotective agent. The dose reduction factor in different groups were: Yinshen Yin high dose 2.01, Yinshen Yin low dose group 1.72, mercaminum group 1.55 and tremella group 1.11

  12. Assessment of the Genotoxicity of olive mill waste water (OMWW) with the Vicia faba Micronucleus test

    International Nuclear Information System (INIS)

    El Hajjouji, H.; Pinelli, E.; Revel, J. C.; Hafidi, M.

    2009-01-01

    Olive mill waste water (OMW) can cause serious environmental hazards in olive producing countries, especially around the Mediterranean basin. In Morocco, olive mills are noe of the foremost polluters: the volume of OMW produced annually is estimated at 250 000 m 3 during the season of production. the present study concerns the genotoxicity of OMW generated in mills producing olive oil in Morocco. (Author)

  13. Tradescantia micronucleus test indicates genotoxic potential of traffic emissions in European cities

    DEFF Research Database (Denmark)

    Klumpp, A.; Ansel, W.; Klumpp, G.

    2006-01-01

    Urban atmospheres contain complex mixtures of air pollutants including mutagenic and carcinogenic substances such as benzene, diesel soot, heavy metals and polycyclic aromatic hydrocarbons. In the frame of a European network for the assessment of air quality by the use of bioindicator plants...

  14. Controlling the complement system in inflammation.

    Science.gov (United States)

    Kirschfink, M

    1997-12-01

    Inappropriate or excessive activation of the complement system can lead to harmful, potentially life-threatening consequences due to severe inflammatory tissue destruction. These consequences are clinically manifested in various disorders, including septic shock, multiple organ failure and hyperacute graft rejection. Genetic complement deficiencies or complement depletion have been proven to be beneficial in reducing tissue injury in a number of animal models of severe complement-dependent inflammation. It is therefore believed that therapeutic inhibition of complement is likely to arrest the process of certain diseases. Attempts to efficiently inhibit complement include the application of endogenous soluble complement inhibitors (C1-inhibitor, recombinant soluble complement receptor 1- rsCR1), the administration of antibodies, either blocking key proteins of the cascade reaction (e.g. C3, C5), neutralizing the action of the complement-derived anaphylatoxin C5a, or interfering with complement receptor 3 (CR3, CD18/11b)-mediated adhesion of inflammatory cells to the vascular endothelium. In addition, incorporation of membrane-bound complement regulators (DAF-CD55, MCP-CD46, CD59) has become possible by transfection of the correspondent cDNA into xenogeneic cells. Thereby, protection against complement-mediated inflammatory tissue damage could be achieved in various animal models of sepsis, myocardial as well as intestinal ischemia/reperfusion injury, adult respiratory distress syndrome, nephritis and graft rejection. Supported by results from first clinical trials, complement inhibition appears to be a suitable therapeutic approach to control inflammation. Current strategies to specifically inhibit complement in inflammation have been discussed at a recent meeting on the 'Immune Consequences of Trauma, Shock and Sepsis', held from March 4-8, 1997, in Munich, Germany. The Congress (chairman: E. Faist, Munich, Germany), which was held in close cooperation with various

  15. Complement activation in Ghanaian children with severe Plasmodium falciparum malaria

    Directory of Open Access Journals (Sweden)

    Ofori Michael F

    2007-12-01

    Full Text Available Abstract Background Severe anaemia (SA, intravascular haemolysis (IVH and respiratory distress (RD are severe forms of Plasmodium falciparum malaria, with RD reported to be of prognostic importance in African children with malarial anaemia. Complement factors have been implicated in the mechanism leading to excess anaemia in acute P. falciparum infection. Methods The direct Coombs test (DCT and flow cytometry were used to investigate the mean levels of RBC-bound complement fragments (C3d and C3bαβ and the regulatory proteins [complement receptor 1 (CD35 and decay accelerating factor (CD55] in children with discrete clinical forms of P. falciparum malaria. The relationship between the findings and clinical parameters including coma, haemoglobin (Hb levels and RD were investigated. Results Of the 484 samples tested, 131(27% were positive in DCT, out of which 115/131 (87.8% were positive for C3d alone while 16/131 (12.2% were positive for either IgG alone or both. 67.4% of the study population were below 5 years of age and DCT positivity was more common in this age group relative to children who were 5 years or older (Odds ratio, OR = 3.8; 95%CI, 2.2–6.7, p Conclusion These results suggest that complement activation contributed to anaemia in acute childhood P. falciparum malaria, possibly through induction of erythrophagocytosis and haemolysis. In contrast to other studies, this study did not find association between levels of the complement regulatory proteins, CD35 and CD55 and malarial anaemia. These findings suggest that complement activation could also be involved in the pathogenesis of RD but larger studies are needed to confirm this finding.

  16. Complement elevation in spinal cord injury.

    Science.gov (United States)

    Rebhun, J; Botvin, J

    1980-05-01

    Laboratory studies revealed an elevated complement in 66% of patients with spinal cord injury. It is postulated that the activated complement may be a component of self-feeding immunological mechanism responsible for the failure of regeneration of a mature mammalian spinal cord. There was no evidence that such an injury had any effect on pre-existing atopy.

  17. Noun complement clauses as referential modifiers

    Directory of Open Access Journals (Sweden)

    Carlos de Cuba

    2017-01-01

    Full Text Available A number of recent analyses propose that so-called noun complement clauses should be analyzed as a type of relative clause. In this paper, I present a number of complications for any analysis that equates noun complement clauses to relative clauses, and conclude that this type of analysis is on the wrong track. I present cross-linguistic evidence showing that the syntactic behavior of noun complement clauses does not pattern with relative clauses. Patterns of complementizer choice and complementizer drop as well as patterns involving main clause phenomena and extraction differ in the two constructions, which I argue is unexpected under a relative clause analysis that involves operator movement. Instead I present an alternative analysis in which I propose that the referentiality of a noun complement clause is linked to its syntactic behavior. Following recent work, I claim that referential clauses have a syntactically truncated left-periphery, and this truncation can account for the lack of main clause phenomena in noun complement clauses. I argue that the truncation analysis is also able to accommodate complementizer data patterns more easily than relative clause analyses that appeal to operator movement.

  18. Complement pathways and meningococcal disease : diagnostic aspects

    DEFF Research Database (Denmark)

    Sjöholm, A G; Truedsson, L; Jensenius, Jens Christian

    2001-01-01

    Complement is an immunological effector system that bridges innate and acquired immunity in several ways. There is a striking association between susceptibility to meningococcal disease and various forms of complement deficiency (1,2). In defense against bacterial infection, the most important fu...

  19. Viral mimicry of the complement system

    Indian Academy of Sciences (India)

    The complement system is a potent innate immune mechanism consisting of cascades of proteins which are designed to fight against and annul intrusion of all the foreign pathogens. Although viruses are smaller in size and have relatively simple structure, they are not immune to complement attack. Thus, activation of the ...

  20. The Anticomplementary Activity of ’Fusobacterium polymorphum’ in Normal and C-4 Deficient Sources of Guinea Pig Complement.

    Science.gov (United States)

    1977-01-12

    A complement consumption assay was used to show that the anticomplementary activity of a cell wall preparation from F. polymorphum in guinea pig complement...tests with C𔃾-deficient guinea pig sera confirmed that F. polymorphum cell walls were capable of generating alternate complement pathway activity in guinea pig sera.

  1. Complement System Part II: Role in Immunity

    Science.gov (United States)

    Merle, Nicolas S.; Noe, Remi; Halbwachs-Mecarelli, Lise; Fremeaux-Bacchi, Veronique; Roumenina, Lubka T.

    2015-01-01

    The complement system has been considered for a long time as a simple lytic cascade, aimed to kill bacteria infecting the host organism. Nowadays, this vision has changed and it is well accepted that complement is a complex innate immune surveillance system, playing a key role in host homeostasis, inflammation, and in the defense against pathogens. This review discusses recent advances in the understanding of the role of complement in physiology and pathology. It starts with a description of complement contribution to the normal physiology (homeostasis) of a healthy organism, including the silent clearance of apoptotic cells and maintenance of cell survival. In pathology, complement can be a friend or a foe. It acts as a friend in the defense against pathogens, by inducing opsonization and a direct killing by C5b–9 membrane attack complex and by triggering inflammatory responses with the anaphylatoxins C3a and C5a. Opsonization plays also a major role in the mounting of an adaptive immune response, involving antigen presenting cells, T-, and B-lymphocytes. Nevertheless, it can be also an enemy, when pathogens hijack complement regulators to protect themselves from the immune system. Inadequate complement activation becomes a disease cause, as in atypical hemolytic uremic syndrome, C3 glomerulopathies, and systemic lupus erythematosus. Age-related macular degeneration and cancer will be described as examples showing that complement contributes to a large variety of conditions, far exceeding the classical examples of diseases associated with complement deficiencies. Finally, we discuss complement as a therapeutic target. PMID:26074922

  2. The Epidermal Growth Factor Receptor Is a Regulator of Epidermal Complement Component Expression and Complement Activation

    DEFF Research Database (Denmark)

    Abu-Humaidan, Anas H A; Ananthoju, Nageshwar; Mohanty, Tirthankar

    2014-01-01

    The complement system is activated in response to tissue injury. During wound healing, complement activation seems beneficial in acute wounds but may be detrimental in chronic wounds. We found that the epidermal expression of many complement components was only increased to a minor extent in skin...

  3. Pathogens' toolbox to manipulate human complement.

    Science.gov (United States)

    Fernández, Francisco J; Gómez, Sara; Vega, M Cristina

    2017-12-14

    The surveillance and pathogen fighting functions of the complement system have evolved to protect mammals from life-threatening infections. In turn, pathogens have developed complex molecular mechanisms to subvert, divert and evade the effector functions of the complement. The study of complement immunoevasion by pathogens sheds light on their infection drivers, knowledge that is essential to implement therapies. At the same time, complement evasion also acts as a discovery ground that reveals important aspects of how complement works under physiological conditions. In recent years, complex interrelationships between infection insults and the onset of autoimmune and complement dysregulation diseases have led to propose that encounters with pathogens can act as triggering factors for disease. The correct management of these diseases involves the recognition of their triggering factors and the development and administration of complement-associated molecular therapies. Even more recently, unsuspected proteins from pathogens have been shown to possess moonlighting functions as virulence factors, raising the possibility that behind the first line of virulence factors there be many more pathogen proteins playing secondary, helping and supporting roles for the pathogen to successfully establish infections. In an era where antibiotics have a progressively reduced effect on the management and control of infectious diseases worldwide, knowledge on the mechanisms of pathogenic invasion and evasion look more necessary and pressing than ever. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Cytokinesis-block micronucleus assay evolves into a 'cytome' assay of chromosomal instability, mitotic dysfunction and cell death

    International Nuclear Information System (INIS)

    Fenech, Michael

    2006-01-01

    The cytokinesis-block micronucleus (CBMN) assay was originally developed as an ideal system for measuring micronuclei (MNi) however it can also be used to measure nucleoplasmic bridges (NPBs), nuclear buds (NBUDs), cell death (necrosis or apoptosis) and nuclear division rate. Current evidence suggests that (a) NPBs originate from dicentric chromosomes in which the centromeres have been pulled to the opposite poles of the cell at anaphase and are therefore indicative of DNA mis-repair, chromosome rearrangement or telomere end-fusions, (b) NPBs may break to form MNi, (c) the nuclear budding process is the mechanism by which cells remove amplified and/or excess DNA and is therefore a marker of gene amplification and/or altered gene dosage, (d) cell cycle checkpoint defects result in micronucleus formation and (e) hypomethylation of DNA, induced nutritionally or by inhibition of DNA methyl transferase can lead to micronucleus formation either via chromosome loss or chromosome breakage. The strong correlation between micronucleus formation, nuclear budding and NPBs (r = 0.75-0.77, P < 0.001) induced by either folic acid deficiency or exposure to ionising radiation is supportive of the hypothesis that folic acid deficiency and/or ionising radiation cause genomic instability and gene amplification by the initiation of breakage-fusion-bridge cycles. In its comprehensive mode, the CBMN assay measures all cells including necrotic and apoptotic cells as well as number of nuclei per cell to provide a measure of cytotoxicity and mitotic activity. The CBMN assay has in fact evolved into a 'cytome' method for measuring comprehensively chromosomal instability phenotype and altered cellular viability caused by genetic defects and/or nutrional deficiencies and/or exogenous genotoxins thus opening up an exciting future for the use of this methodology in the emerging fields of nutrigenomics and toxicogenomics and their combinations

  5. Relative Contribution of Cellular Complement Inhibitors CD59, CD46, and CD55 to Parainfluenza Virus 5 Inhibition of Complement-Mediated Neutralization

    Directory of Open Access Journals (Sweden)

    Yujia Li

    2018-04-01

    Full Text Available The complement system is a part of the innate immune system that viruses need to face during infections. Many viruses incorporate cellular regulators of complement activation (RCA to block complement pathways and our prior work has shown that Parainfluenza virus 5 (PIV5 incorporates CD55 and CD46 to delay complement-mediated neutralization. In this paper, we tested the role of a third individual RCA inhibitor CD59 in PIV5 interactions with complement pathways. Using a cell line engineered to express CD59, we show that small levels of functional CD59 are associated with progeny PIV5, which is capable of blocking assembly of the C5b-C9 membrane attack complex (MAC. PIV5 containing CD59 (PIV5-CD59 showed increased resistance to complement-mediated neutralization in vitro comparing to PIV5 lacking regulators. Infection of A549 cells with PIV5 and RSV upregulated CD59 expression. TGF-beta treatment of PIV5-infected cells also increased cell surface CD59 expression and progeny virions were more resistant to complement-mediated neutralization. A comparison of individual viruses containing only CD55, CD46, or CD59 showed a potency of inhibiting complement-mediated neutralization, which followed a pattern of CD55 > CD46 > CD59.

  6. Autocrine Effects of Tumor-Derived Complement

    Directory of Open Access Journals (Sweden)

    Min Soon Cho

    2014-03-01

    Full Text Available We describe a role for the complement system in enhancing cancer growth. Cancer cells secrete complement proteins that stimulate tumor growth upon activation. Complement promotes tumor growth via a direct autocrine effect that is partially independent of tumor-infiltrating cytotoxic T cells. Activated C5aR and C3aR signal through the PI3K/AKT pathway in cancer cells, and silencing the PI3K or AKT gene in cancer cells eliminates the progrowth effects of C5aR and C3aR stimulation. In patients with ovarian or lung cancer, higher tumoral C3 or C5aR mRNA levels were associated with decreased overall survival. These data identify a role for tumor-derived complement proteins in promoting tumor growth, and they therefore have substantial clinical and therapeutic implications.

  7. Genetics Home Reference: complement component 2 deficiency

    Science.gov (United States)

    ... Topic: Immune System and Disorders Health Topic: Lupus Genetic and Rare Diseases Information Center (1 link) Complement component 2 deficiency Additional NIH Resources (1 link) National Institute of Allergy and Infectious Diseases: Primary Immune Deficiency Diseases Educational Resources (6 ...

  8. Kinetics of micronucleus induction and cytotoxicity caused by distinct antineoplastics and alkylating agents in vivo.

    Science.gov (United States)

    Morales-Ramírez, Pedro; Vallarino-Kelly, Teresita; Cruz-Vallejo, Virginia

    2014-01-30

    This mini-review aims to compare the differences in the kinetics of the induction of micronucleated polychromatic erythrocytes (MN-PCE) and cytotoxicity by distinct antineoplastic and genotoxic agents in murine peripheral blood in vivo and to correlate these kinetics with the underlying processes. Comparisons were carried out using our previously obtained data with nominal doses causing similar levels of cytotoxicity, as measured in terms reduction of PCE. The aneuploidogens caused the most rapid induction of MN-PCEs and had the highest rates of cytotoxicity and genotoxicity. The promutagens cyclophosphamide and dimethylnitrosamine showed the most delayed responses and had the lowest genotoxic and cytotoxic efficiencies. DNA crosslinking agents had a similar delay of 4-5 h, greater than those of aneuploidogens, but differed in their cytotoxic and genotoxic efficiencies. Methylnitrosourea and 5-aza-cytidine caused greater delays than crosslinking agents. These delays can be due to the methylnitrosourea-mediated induction of formation of mono alkyl adducts which are interpreted as mismatches during DNA duplication, whereas 5-aza-cytidine requires incorporation into the DNA to induce breakage. This review allows us to conclude that the requirement for metabolic activation and the mechanisms of DNA breakage and of micronucleus induction are the main factors that affect the time of maximal MN-PCE induction. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  9. Effect of mobile phone station on micronucleus frequency and chromosomal aberrations in human blood cells.

    Science.gov (United States)

    Yildirim, M S; Yildirim, A; Zamani, A G; Okudan, N

    2010-01-01

    The use of mobile telephones has rapidly increased worldwide as well as the number of mobile phone base stations that lead to rise low level radiofrequency emissions which may in turn have possible harm for human health. The national radiation protection board has published the known effects of radio waves exposure on humans living close to mobile phone base stations. However, several studies have claimed that the base station has detrimental effects on different tissues. In this study, we aimed to evaluate the effects of mobile phone base stations on the micronucleus (MN) frequency and chromosomal aberrations on blood in people who were living around mobile phone base stations and healthy controls. Frequency of MN and chromosomal aberrations in study and control groups was 8.96 +/- 3.51 and 6.97 +/- 1.52 (p: 0.16); 0.36 +/- 0.31 and 0.75 +/- 0.61 (p: 0.07), respectively. Our results show that there was not a significant difference of MN frequency and chromosomal aberrations between the two study groups. The results claim that cellular phones and their base stations do not produce important carcinogenic changes.

  10. Effects of heavy metals/metalloids contamination of soils on micronucleus induction in Tradescantia pallida

    Directory of Open Access Journals (Sweden)

    Neelima Meravi

    2013-06-01

    Full Text Available The present study was conducted in GGV campus, Bilaspur in which heavy metals/metalloids speciation of soil (for Cr, Fe, Ni, Cd and Pb was performed for assessing the genotoxicity of these metals. The metals concentrations were measured with the help of AAS 7000 (Shimadzu and the standard solution was prepared using standard metal solution of Inorganic Ventures. The concentrations of Cr, Fe, Ni, Cd and Pb (in ug/100 g soil were 12.4, 33.9, 3.1, 0.07 and 2.4 respectively. The flowers of Tradescantia pallida plants growing in this soil were taken and their micronucleus (Trad-MCN bioassay was performed. Trad-MCN bioassay was performed using the protocols established by Ma (1981. The study revealed that at these concentrations of metals micronuclei (stained objects that were smaller than the nuclei and not connected to the nuclei are classified as MCN were formed. Therefore it can be inferred from the present study that soil of GGV campus is genotoxic for the Tradescantia pallida.

  11. Synergistic interaction of radiation and octylphenol evaluated by tradescantia-micronucleus assay

    International Nuclear Information System (INIS)

    Shin, H. S.; Lee, J. H.; Lee, B. H.; Kim, J. K.

    2003-01-01

    Many kinds of synthetic chemicals have been being used for various purposes. Some of them are called 'endocrine disruptors' because they can disturb the endocrine system of organisms. Presently no technique is established for the quantitative assessment of biological risk of the environmental hormones. The pollen mother cells (PMC) of tradescantia are very sensitive to chemical toxicants or ionizing radiation, and thus can be used as a biological end- point for assessing their effects. Micronucleus frequencies in PMC showed a good dose- and concentration-response relationship for radiation and bisphenol A. The MCN frequencies in the pollen mother cells treated with octylphenol were 4.20, 7.27, 4.93 MCN/100 tetrads for 1, 5 and 10 μM, respectively. On the other hand, the frequencies were 10.13, 19.27, 24.47 MCN/100 tetrads for the octylphenol treatments (1, 5, and 10 μM) combined with 30 cGy irradiation. The MCN frequency of 30 cGy control was 8.00 MCN/100 tetrads for the octylphenol treatments (1, 5, and 10μM) combined with 30 cGy irradiation. The MCN frequency of 30 cGy control was 8.00 MCN/100 tetrads. It is known from the result that the Trad-MCN assay can be an excellent tool for the detection of biologically harmful effects of environmental toxicants or synthetic chemicals

  12. Nuclear localization signal targeting to macronucleus and micronucleus in binucleated ciliate Tetrahymena thermophila.

    Science.gov (United States)

    Iwamoto, Masaaki; Mori, Chie; Osakada, Hiroko; Koujin, Takako; Hiraoka, Yasushi; Haraguchi, Tokuko

    2018-06-08

    Ciliated protozoa possess two morphologically and functionally distinct nuclei: a macronucleus (MAC) and a micronucleus (MIC). The MAC is transcriptionally active and functions in all cellular events. The MIC is transcriptionally inactive during cell growth, but functions in meiotic events to produce progeny nuclei. Thus, these two nuclei must be distinguished by the nuclear proteins required for their distinct functions during cellular events such as cell proliferation and meiosis. To understand the mechanism of the nuclear transport specific to either MAC or MIC, we identified specific nuclear localization signals (NLSs) in two MAC- and MIC-specific nuclear proteins, macronuclear histone H1 and micronuclear linker histone-like protein (Mlh1), respectively. By expressing GFP-fused fragments of these proteins in Tetrahymena thermophila cells, two distinct regions in macronuclear histone H1 protein were assigned as independent MAC-specific NLSs and two distinct regions in Mlh1 protein were assigned as independent MIC-specific NLSs. These NLSs contain several essential lysine residues responsible for the MAC- and MIC-specific nuclear transport, but neither contains any consensus sequence with known monopartite or bipartite NLSs in other model organisms. Our findings contribute to understanding how specific nuclear targeting is achieved to perform distinct nuclear functions in binucleated ciliates. © 2018 The Authors. Genes to Cells published by Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.

  13. Surviving mousepox infection requires the complement system.

    Directory of Open Access Journals (Sweden)

    Elizabeth A Moulton

    2008-12-01

    Full Text Available Poxviruses subvert the host immune response by producing immunomodulatory proteins, including a complement regulatory protein. Ectromelia virus provides a mouse model for smallpox where the virus and the host's immune response have co-evolved. Using this model, our study investigated the role of the complement system during a poxvirus infection. By multiple inoculation routes, ectromelia virus caused increased mortality by 7 to 10 days post-infection in C57BL/6 mice that lack C3, the central component of the complement cascade. In C3(-/- mice, ectromelia virus disseminated earlier to target organs and generated higher peak titers compared to the congenic controls. Also, increased hepatic inflammation and necrosis correlated with these higher tissue titers and likely contributed to the morbidity in the C3(-/- mice. In vitro, the complement system in naïve C57BL/6 mouse sera neutralized ectromelia virus, primarily through the recognition of the virion by natural antibody and activation of the classical and alternative pathways. Sera deficient in classical or alternative pathway components or antibody had reduced ability to neutralize viral particles, which likely contributed to increased viral dissemination and disease severity in vivo. The increased mortality of C4(-/- or Factor B(-/- mice also indicates that these two pathways of complement activation are required for survival. In summary, the complement system acts in the first few minutes, hours, and days to control this poxviral infection until the adaptive immune response can react, and loss of this system results in lethal infection.

  14. Complement and thrombosis in the antiphospholipid syndrome.

    Science.gov (United States)

    Oku, Kenji; Nakamura, Hiroyuki; Kono, Michihiro; Ohmura, Kazumasa; Kato, Masaru; Bohgaki, Toshiyuki; Horita, Tetsuya; Yasuda, Shinsuke; Amengual, Olga; Atsumi, Tatsuya

    2016-10-01

    The involvement of complement activation in the pathophysiology of antiphospholipid syndrome (APS) was first reported in murine models of antiphospholipid antibody (aPL)-related pregnancy morbidities. We previously reported that complement activation is prevalent and may function as a source of procoagulant cell activation in the sera of APS patients. Recently, autoantibodies against C1q, a component of complement 1, were reported to be correlated with complement activation in systemic lupus erythematosus. These antibodies target neoepitopes of deformed C1q bound to various molecules (i.e., anionic phospholipids) and induce accelerated complement activation. We found that anti-C1q antibodies are more frequently detected in primary APS patients than in control patients and in refractory APS patients with repeated thrombotic events. The titer of anti-C1q antibodies was significantly higher in refractory APS patients than in APS patients without flare. The binding of C1q to anionic phospholipids may be associated with the surge in complement activation in patients with anti-C1q antibodies when triggered by 'second-hit' biological stressors such as infection. Such stressors will induce overexpression of anionic phospholipids, with subsequent increases in deformed C1q that is targeted by anti-C1q antibodies. Copyright © 2016. Published by Elsevier B.V.

  15. Effect of smoking habit on the frequency of micronuclei in human lymphocytes: results from the human micronucleus project

    International Nuclear Information System (INIS)

    Bonassi, Stefano; Neri, M.; Lando, Cecilia

    2004-01-01

    Full text: The effect of tobacco smoking on the frequency of micronuclei (MN) in human lymphocytes has been the object of many population studies. In most reports, the results were unexpectedly negative, and in many instances smokers had lower frequencies of MN than non-smokers. A pooled re-analysis of 24 databases from the HUMN international collaborative project has been performed with the aim of understanding the impact of smoking habits on MN frequency. The complete database included 5710 subjects, with 3501 non-smokers, 1409 current smokers, and 800 former smokers, among subjects in occupational and environmental surveys. The overall result of the re-analysis confirmed the small decrease of MN frequencies in current smokers (frequency ratio (FR =0.97, 95% confidence interval (CI =0.93-1.01) and in former smokers (FR =0.96, 95% CI =0.91-1.01), when compared to non-smokers. MN frequency was not influenced by the number of cigarettes smoked per day among subjects occupationally exposed to genotoxic agents, whereas a typical U-shaped curve is observed for non-exposed smokers, showing a significant increase of MN frequency in individuals smoking 30 cigarettes or more per day (FR =1.59, 95% CI =1.35-1.88). This analysis confirmed that smokers do not experience an overall increase in MN frequency, although when the interaction with occupational exposure is taken into account, heavy smokers were the only group showing a significant increase in genotoxic damage as measured by the micronucleus assay in lymphocytes. From these results some general recommendations for the design of bio monitoring studies involving smokers can be formulated. Quantitative data about smoking habit should always be collected because, in the absence of such data, the simple comparison of smokers versus non-smokers could be misleading. The sub-group of heavy smokers (≥30 cigarettes per day) should be specifically evaluated whenever it is large enough to satisfy statistical requirements. The

  16. Francisella tularensis Confronts the Complement System

    Directory of Open Access Journals (Sweden)

    Susan R. Brock

    2017-12-01

    Full Text Available Francisella tularensis has developed a number of effective evasion strategies to counteract host immune defenses, not the least of which is its ability to interact with the complement system to its own advantage. Following exposure of the bacterium to fresh human serum, complement is activated and C3b and iC3b can be found covalently attached to the bacterial surface. However, the lipopolysaccharide and capsule of the F. tularensis cell wall prevent complement-mediated lysis and endow the bacterium with serum resistance. Opsonization of F. tularensis with C3 greatly increases its uptake by human neutrophils, dendritic cells and macrophages. Uptake occurs by an unusual looping morphology in human macrophages. Complement receptor 3 is thought to play an important role in opsonophagocytosis by human macrophages, and signaling through this receptor can antagonize Toll-like receptor 2-initiated macrophage activation. Complement C3 also determines the survival of infected human macrophages and perhaps other cell types. C3-opsonization of F. tularensis subsp. tularensis strain SCHU S4 results in greatly increased death of infected human macrophages, which requires more than complement receptor engagement and is independent of the intracellular replication by the pathogen. Given its entry into the cytosol of host cells, F. tularensis has the potential for a number of other complement-mediated interactions. Studies on the uptake C3-opsonized adenovirus have suggested the existence of a C3 sensing system that initiates cellular responses to cytosolic C3b present on invading microbes. Here we propose that C3 peptides enter the cytosol of human macrophages following phagosome escape of F. tularensis and are recognized as intruding molecular patterns that signal host cell death. With the discovery of new roles for intracellular C3, a better understanding of tularemia pathogenesis is likely to emerge.

  17. Plasma complement biomarkers distinguish multiple sclerosis and neuromyelitis optica spectrum disorder.

    Science.gov (United States)

    Hakobyan, Svetlana; Luppe, Sebastian; Evans, David Rs; Harding, Katharine; Loveless, Samantha; Robertson, Neil P; Morgan, B Paul

    2017-06-01

    Multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) are autoimmune inflammatory demyelinating diseases of the central nervous system. Although distinguished by clinicoradiological and demographic features, early manifestations can be similar complicating management. Antibodies against aquaporin-4 support the diagnosis of NMOSD but are negative in some patients. Therefore, there is unmet need for biomarkers that enable early diagnosis and disease-specific intervention. We investigated whether plasma complement proteins are altered in MS and NMOSD and provide biomarkers that distinguish these diseases. Plasma from 54 NMOSD, 40 MS and 69 control donors was tested in multiplex assays measuring complement activation products and proteins. Using logistic regression, we tested whether combinations of complement analytes distinguished NMOSD from controls and MS. All activation products were elevated in NMOSD compared to either control or MS. Four complement proteins (C1inh, C1s, C5 and FH) were higher in NMOSD compared to MS or controls. A model comprising C1inh and terminal complement complex (TCC) distinguished NMOSD from MS (area under the curve (AUC): 0.98), while C1inh and C5 distinguished NMOSD from controls (AUC: 0.94). NMOSD is distinguished from MS by plasma complement biomarkers. Selected complement analytes enable differential diagnosis. Findings support trials of anti-complement therapies in NMOSD.

  18. Study design and statistical analysis of data in human population studies with the micronucleus assay.

    Science.gov (United States)

    Ceppi, Marcello; Gallo, Fabio; Bonassi, Stefano

    2011-01-01

    The most common study design performed in population studies based on the micronucleus (MN) assay, is the cross-sectional study, which is largely performed to evaluate the DNA damaging effects of exposure to genotoxic agents in the workplace, in the environment, as well as from diet or lifestyle factors. Sample size is still a critical issue in the design of MN studies since most recent studies considering gene-environment interaction, often require a sample size of several hundred subjects, which is in many cases difficult to achieve. The control of confounding is another major threat to the validity of causal inference. The most popular confounders considered in population studies using MN are age, gender and smoking habit. Extensive attention is given to the assessment of effect modification, given the increasing inclusion of biomarkers of genetic susceptibility in the study design. Selected issues concerning the statistical treatment of data have been addressed in this mini-review, starting from data description, which is a critical step of statistical analysis, since it allows to detect possible errors in the dataset to be analysed and to check the validity of assumptions required for more complex analyses. Basic issues dealing with statistical analysis of biomarkers are extensively evaluated, including methods to explore the dose-response relationship among two continuous variables and inferential analysis. A critical approach to the use of parametric and non-parametric methods is presented, before addressing the issue of most suitable multivariate models to fit MN data. In the last decade, the quality of statistical analysis of MN data has certainly evolved, although even nowadays only a small number of studies apply the Poisson model, which is the most suitable method for the analysis of MN data.

  19. Dose-response relationship of octylphenol and radiation evaluated by tradescantia-micronucleus assay

    International Nuclear Information System (INIS)

    Kim, J. K.; Cheon, K. J.; Lee, B. H.; Shin, H. S.; Lee, J. H.

    2002-01-01

    Many kinds of synthetic chemicals have been being used for various purposes. Some of them are called 'Endocrine Disruptor's because they can disturb the endocrine system of organisms. Presently no technique is established for the quantitative assessment of biological risk of the environmental hormones. The pollen mother cells (PMC) of Tradescantia are very sensitive to chemical toxicants or ionizing radiation, and thus can be used as a biological end-point assessing their effect. Micronucleus frequencies in PMC showed a good dose- and concentration-response relationship for radiation, bisphenol A and octylphenol. A parallel series of experiment using five increasing doses of gamma-ray at 10, 20, 30, 40 and 50 cGy was conducted. The MCN frequencies of 12.0, 25.2, 41.7, 76 and 83 MCN/100 tetrads were observed from each of the increasing gamma-ray dosage groups, respectively. Lenear regression analysis of the gamma-ray data MCN frequencies yielded a correlation coefficient of 0.95. the MCN frequencies in pollen mother cells treated with bisphenol a and octylphenol showed dose-response relationship in a concentration of 0, 1, 2, 4 μM and 0, 4, 10, 20 μM. the MCN frequency for the bisphenol a and octylphenol group yields 2.33, 8.06, 12.7 and 19.6 MCN/100 tetrads for the bisphenol a and 2.33, 2.33, 11.47, 17.6 MCN/100 tetrads for the octylphenol. The MCN frequency of the control was 2.33 MCN/100 tetrads. It is known from the result that Trad-MCN assay can be an excellent tool for detection of biological risk due to environmental toxicants or synthetic chemicals

  20. Complement propriety and conspiracy in nanomedicine

    DEFF Research Database (Denmark)

    Moghimi, Seyed Moein

    2016-01-01

    The complement system is the first line of body's defense against intruders and it acts as a functional bridge between innate and adaptive arms of the immune system. This commentary examines the key roles of complement activation in response to nanomedicine administration, including nucleic acid...... complexes. These comprise beneficial (eg, adjuvanticity) as well as adverse effects (eg, infusion-related reactions). Pigs (and sheep) are often used as predictive models of nanomedicine-mediated infusion-related reactions in humans. The validity of these models in relation to human responses is questioned...

  1. Complement-mediated solubilization of immune complexes. Solubilization inhibition and complement factor levels in SLE patients

    DEFF Research Database (Denmark)

    Baatrup, Gunnar; Petersen, Ivan; Kappelgaard, E

    1984-01-01

    Thirty-two of 36 serum samples from 19 SLE patients showed reduced capacity to mediate complement-dependent solubilization of immune complexes (IC). SLE patients with nephritis exerted the lowest complement-mediated solubilization capacity (CMSC) whereas sera from patients with inactive disease g...

  2. Vinclozolin, a widely used fungizide, enhanced BaP-induced micronucleus formation in human derived hepatoma cells by increasing CYP1A1 expression.

    Science.gov (United States)

    Wu, Xin-Jiang; Lu, Wen-qing; Roos, Peter H; Mersch-Sundermann, Volker

    2005-10-15

    Vinclozolin, a widely used fungicide, can be identified as a residue in numerous vegetable and fruit samples. To get insight in its genetic toxicity, we investigated the genotoxic effect of vinclozolin in the human derived hepatoma cell line HepG2 using the micronucleus (MN) assay. Additionally, to evaluate the co- or anti-mutagenic potency of vinclozolin, we treated HepG2 cells with different concentrations of vinclozolin for 24 h. Subsequently, the cells were exposed to benzo[a]pyrene (BaP) for 1h. Exposure of HepG2 cells to 50-400 microM vinclozolin alone did not cause any induction of micronuclei. However, a pronounced co-mutagenic effect was observed. MN frequencies caused by BaP increased by 30.6%, 52.8% and 65.3% after pretreatment of the cell cultures with 50, 100 and 200 microM vinclozolin, respectively. The highest concentration (400 microM) of vinclozolin tested caused cytotoxicity. Therefore, micronuclei were not considered for that concentration. To clarify the mechanism of cogenotoxicity, we assayed cytochrome P450 1A1 (CYP1A1), which plays a pivotal role in activation of BaP. Cells exposed to vinclozolin led to significant increase of CYP1A1 expression in Western blot. The result suggested that induction of CYP1A1 by vinclozolin account for its enhancing effect on genotoxicity caused by BaP.

  3. Evaluation of the repeated dose liver micronucleus assay using young adult rats with cyclophosphamide monohydrate: a report of a collaborative study by CSGMT/JEMS.MMS.

    Science.gov (United States)

    Matsumoto, Kazumi; Zaizen, Kazuyo; Miyamoto, Atsushi; Wako, Yumi; Kawasako, Kazufumi; Ishida, Hisao

    2015-03-01

    The repeated dose liver micronucleus (RDLMN) assay using young adult rats has the potential to detect liver carcinogens, and this assay could be integrated into general toxicological studies. In this study, in order to assess the performance of the assay, cyclophosphamide monohydrate (CP) was tested in a 14-day RDLMN assay. Based on the results of the 4-day repeated dose-finding study, 10 mg/kg/day of CP was selected as the highest dose and the lower doses were set at 5, 2.5, 1.25, and 0.625 mg/kg/day for the 14-day RDLMN assay. On the day after the completion of the dosing period, specimens of hepatocytes and bone marrow cells were prepared and the induction of micronuclei was assessed. No changes were observed in the incidences of micronucleated hepatocytes. Nevertheless, the incidences of micronucleated immature erythrocytes in the bone marrow were increased significantly at CP doses of 1.25 mg/kg/day or more. These findings are consistent with reports that CP induces tumors in various tissues but it does not induce liver tumors.

  4. Mesenchymal stromal cells engage complement and complement receptor bearing innate effector cells to modulate immune responses.

    Directory of Open Access Journals (Sweden)

    Guido Moll

    Full Text Available Infusion of human third-party mesenchymal stromal cells (MSCs appears to be a promising therapy for acute graft-versus-host disease (aGvHD. To date, little is known about how MSCs interact with the body's innate immune system after clinical infusion. This study shows, that exposure of MSCs to blood type ABO-matched human blood activates the complement system, which triggers complement-mediated lymphoid and myeloid effector cell activation in blood. We found deposition of complement component C3-derived fragments iC3b and C3dg on MSCs and fluid-phase generation of the chemotactic anaphylatoxins C3a and C5a. MSCs bound low amounts of immunoglobulins and lacked expression of complement regulatory proteins MCP (CD46 and DAF (CD55, but were protected from complement lysis via expression of protectin (CD59. Cell-surface-opsonization and anaphylatoxin-formation triggered complement receptor 3 (CD11b/CD18-mediated effector cell activation in blood. The complement-activating properties of individual MSCs were furthermore correlated with their potency to inhibit PBMC-proliferation in vitro, and both effector cell activation and the immunosuppressive effect could be blocked either by using complement inhibitor Compstatin or by depletion of CD14/CD11b-high myeloid effector cells from mixed lymphocyte reactions. Our study demonstrates for the first time a major role of the complement system in governing the immunomodulatory activity of MSCs and elucidates how complement activation mediates the interaction with other immune cells.

  5. Identifying pathogenicity of human variants via paralog-based yeast complementation.

    Directory of Open Access Journals (Sweden)

    Fan Yang

    2017-05-01

    Full Text Available To better understand the health implications of personal genomes, we now face a largely unmet challenge to identify functional variants within disease-associated genes. Functional variants can be identified by trans-species complementation, e.g., by failure to rescue a yeast strain bearing a mutation in an orthologous human gene. Although orthologous complementation assays are powerful predictors of pathogenic variation, they are available for only a few percent of human disease genes. Here we systematically examine the question of whether complementation assays based on paralogy relationships can expand the number of human disease genes with functional variant detection assays. We tested over 1,000 paralogous human-yeast gene pairs for complementation, yielding 34 complementation relationships, of which 33 (97% were novel. We found that paralog-based assays identified disease variants with success on par with that of orthology-based assays. Combining all homology-based assay results, we found that complementation can often identify pathogenic variants outside the homologous sequence region, presumably because of global effects on protein folding or stability. Within our search space, paralogy-based complementation more than doubled the number of human disease genes with a yeast-based complementation assay for disease variation.

  6. Graphs whose complement and square are isomorphic

    DEFF Research Database (Denmark)

    Pedersen, Anders Sune

    2014-01-01

    We study square-complementary graphs, that is, graphs whose complement and square are isomorphic. We prove several necessary conditions for a graph to be square-complementary, describe ways of building new square-complementary graphs from existing ones, construct infinite families of square-compl...

  7. Complement Activation by Ceramide Transporter Proteins

    NARCIS (Netherlands)

    Bode, G.H.; Losen, M.; Buurman, W.A.; Veerhuis, R.; Molenaar, P.C.; Steinbusch, H.W.M.; De Baets, M.H.; Daha, MR; Martinez-Martinez, P.

    2014-01-01

    C1q is the initiator of the classical complement pathway and, as such, is essential for efficient opsonization and clearance of pathogens, altered self-structures, and apoptotic cells. The ceramide transporter protein (CERT) and its longer splicing isoform CERTL are known to interact with

  8. Biological Dosimetry Using Micronucleus Assay in Simulated Partial-Body Exposure to Ionizing Radiation

    Directory of Open Access Journals (Sweden)

    S. Purnami

    2017-08-01

    Full Text Available In radiation accidents, it is common that only several parts of the body are exposed to radiation. As a consequence there is a mixture of exposed and unexposed lymphocytes in peripheral blood cells of the samples. This phenomenon will cause the dose value estimated using the exposed lymphocytes to be lower than the actual dose. In this study, an assessment of partial body exposures using micronucleus assay by estimating the partial body dose and fraction of irradiated blood was conducted. An optimal D0 value also has been determined in this study to estimate the fraction of irradiated cells. Peripheral blood lymphocytes (PBLs from three healthy donors were irradiated in vitro with 2 Gy of X-rays. Partial radiation exposure was simulated by mixing the irradiated and non-irradiated blood in different proportions. The proportions of mixtures of blood samples irradiated in vitro were 5, 10, 15, 20, and 30 %. Blood samples were then cultured and harvested based on micronuclei assay protocol. At least 2000 binucleated cells with well-preserved cytoplasm were scored for the MN frequency. Dose Estimate 5.1 software was used to calculate the dispersion index (σ2/y and normalized unit of this index (U in each proportion of bloods. The fractions of irradiated cells were calculated with CABAS (Chromosomal Aberration Calculation Software for several different D0 values (2.7; 3.8; 5.4. The results showed that D0 value at 5.4 gave the closest results to the actual proportion of irradiated bloods, while for the dose estimation the estimated doses value from all proportions in all donors were higher than the actual dose. The factor that may cause this phenomenon was that the dose response calibration curve used to predict the radiation dose was not constructed in the laboratory used. Overall it can be concluded that a biodosimetry using MN assay can be used to estimate the radiation dose in partial body exposure. In order to establish a biodosimetry using MN

  9. A reação de fixação do complemento na tipificação de vírus da gripe isolados no Rio de Janeiro The complement fixation test in the typefication of influenza viruses isolated in Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    J. Guilherme Lacorte

    1976-01-01

    Full Text Available O autor estudou, pela reação de fixação do complemento, amostras de vírus da gripe isoladas no Rio de janeiro, durante a epidemia de 1973. Preparou imunesoros em hamsters pela inoculação do líquido alantóide de embriões de galinha infectados. o antígeno solúvel foi preparado com líquido obtido da mesma proveniência. As reações foram positivas, em grau variável, com as amostras clássicas PR8, FM1 e Ásia dos subtipos A0,A1 e A2 e as mais recentes A2/Hong Kong/68 e A2/England/72 e negativa com o anticorpo B/Mass/66. Para as duas variantes do subtipo A2, acima assinaladas e para as 7 amostras isoladas o comportamento foi praticamente o mesmo, não deixando de ser uma reação tipo específica se encararmos, também, as reações obtidas com as demais variantes do tipo A.The author studied by the complement fixation test the influenza virus strains isolated in Rio de Janeiro during the 1973 epidemic. He prepared immunesera in hamsters by the inoculation of the allantoic fluid from infected chick embryos with each of the 7 isolated strains and the standard strains. The soluble antigens were prepared with the allantoic fluid of infected chick embryos. The tests were identically positive with the A2/Hong Kong/68 and A2/England/72 antigens and negative with the B/Mass/66. The tets were type specific and the behaviour of the A2/Hong Kong/68 and the A2/England/72 and the 7 strains of the isolated viruses was almost the same. They fixed 3 or 4 units of complement. The variants PR8, FM1 and Asia fixed only 2 units of complement.

  10. Biomonitoring of genotoxic risk in radar facility workers: comparison of the comet assay with micronucleus assay and chromatid breakage assay

    International Nuclear Information System (INIS)

    Garaj-Vrhovac, V.; Kopjar, N.

    2003-01-01

    Genotoxic risks of occupational exposure in a radar facility were evaluated by using alkaline comet assay, micronucleus assay and chromatid breakage assay on peripheral blood leukocytes in exposed subjects and corresponding controls. Results show that occupational exposure to microwave radiation correlates with an increase of genome damage in somatic cells. The levels of DNA damage in exposed subjects determined by using alkaline comet assay were increased compared to control and showed interindividual variations. Incidence of micronuclei was also significantly increased compared to baseline control values. After short exposure of cultured lymphocytes to bleomycin, cells of occupationally exposed subjects responded with high numbers of chromatid breaks. Although the level of chromosome damage generated by bleomycin varied greatly between individuals, in exposed subjects a significantly elevated number of chromatid breaks was observed. Our results support data reported in literature indicating that microwave radiation represents a potential DNA-damaging hazard. Alkaline comet assay is confirmed as a sensitive and highly reproducible technique for detection of primary DNA damage inflicted in somatic cells. Micronucleus assay was confirmed as reliable bio-markers of effect and chromatid breakage assay as sensitive bio-marker of individual cancer susceptibility. The results obtained also confirm the necessity to improve measures and to perform accurate health surveillance of individuals occupationally exposed to microwave radiation

  11. 3-Nitrobenzanthrone (3-NBA) induced micronucleus formation and DNA damage in human hepatoma (HepG2) cells.

    Science.gov (United States)

    Lamy, Evelyn; Kassie, Fekadu; Gminski, Richard; Schmeiser, Heinz H; Mersch-Sundermann, Volker

    2004-01-15

    3-Nitrobenzanthrone (3-NBA), identified in diesel exhaust and in airborne particulate matter, is a potent mutagen in Salmonella, induces micronuclei formation in mice and in human cells and DNA adducts in rats. In the present study, we investigated the genotoxic potency of 3-NBA in human HepG2 cells using the micronucleus (MN) assay and the single cell gel electrophoresis (SCGE). 3-NBA caused a genotoxic effect at concentrations > or =12 nM in both assays. In the micronucleus assay, we found 98.7+/-10.3 MN/1000 BNC at a concentration of 100 nM 3-NBA in comparison to 27.3+/-0.6 MN/1000 BNC with the negative control. At the same concentration, the DNA-migration (SCGE) showed an Olive tail moment (OTM) of 2.7+/-0.45 and %DNA in the tail of 8.28+/-0.76; OTM and %DNA in the tail of cells treated with the negative control were 0.73+/-0.08 and 2.81+/-0.30, respectively. The results are discussed under consideration of former studies.

  12. Dose response curve for micronucleus of cytokinesis-block method in human lymphocytes after 60Co-gamma ray exposure

    International Nuclear Information System (INIS)

    Gao Jinsheng; Zheng Siying; Cai Feng

    1993-08-01

    The micronucleus technique of cytokines block has been proposed as a new method to measure chromosome damage in cytogenetic. The cytokines is blocked by using cytochalasin B (Cyt-B), and micronuclei are scored in cytokines-blocked (CB) cells. This can easily be done owing to the appearance of binucleate cells and large numbers accumulated by adding 3.0 μg/ml cytochalasin B at 44 hours and scoring at 72 hours. The results show that the optimum concentration of Cyt-B is 3.0 μg/ml. the Cyt-B itself can not induce the increase of micronuclei. The micronucleus frequency of normal individuals in vivo, there is an approximately linear relationship between the frequency of induced micronuclei and irradiation dose. The formula is Y 0.36 D + 2.74 (γ 2 = 0.995 P<0.01). Because the cytokines block method is simple and reliable, it is effective for assaying chromosome damage caused by genetic toxic materials

  13. Intragenic complementation by the nifJ-coded protein of Klebsiella pneumoniae.

    OpenAIRE

    Stacey, G; Zhu, J; Shah, V K; Shen, S C; Brill, W J

    1982-01-01

    A single mutation, nifC1005 (Jin et al. Sci. Sin. 23:108-118, 1980), located between nifH and nifJ in the nif cluster of Klebsiella pneumoniae, genetically complemented mutations in each of the 17 known nif genes. This suggested that the mutation is located in a new nif gene. We showed by complementation analyses that only 3 of 12 nifJ mutations tested were complemented by nifC1005. Nitrogenase activity in cell extracts of the mutant with nifC1005 as well as NifJ- mutants was stimulated by th...

  14. complement C3, Complement C4 and C-reactive protein

    African Journals Online (AJOL)

    ajl yemi

    2011-12-19

    Dec 19, 2011 ... (IL-6), E-selectin and P-selectin (Perlstein and Lee,. 2006). Studies have ... of cigarette smoke causes complement activation which is in turn ..... are decreased by long term smoking cessation in male smokers. Prevent. Med.

  15. Complement activation by ceramide transporter proteins.

    Science.gov (United States)

    Bode, Gerard H; Losen, Mario; Buurman, Wim A; Veerhuis, Robert; Molenaar, Peter C; Steinbusch, Harry W M; De Baets, Marc H; Daha, Mohamed R; Martinez-Martinez, Pilar

    2014-02-01

    C1q is the initiator of the classical complement pathway and, as such, is essential for efficient opsonization and clearance of pathogens, altered self-structures, and apoptotic cells. The ceramide transporter protein (CERT) and its longer splicing isoform CERTL are known to interact with extracellular matrix components, such as type IV collagen, and with the innate immune protein serum amyloid P. In this article, we report a novel function of CERT in the innate immune response. Both CERT isoforms, when immobilized, were found to bind the globular head region of C1q and to initiate the classical complement pathway, leading to activation of C4 and C3, as well as generation of the membrane attack complex C5b-9. In addition, C1q was shown to bind to endogenous CERTL on the surface of apoptotic cells. These results demonstrate the role of CERTs in innate immunity, especially in the clearance of apoptotic cells.

  16. Complementation analysis of ataxia-telangiectasia

    International Nuclear Information System (INIS)

    Jaspers, N.G.; Painter, R.B.; Paterson, M.C.; Kidson, C.; Inoue, T.

    1985-01-01

    In a number of laboratories genetic analysis of ataxia-telangiectasia (AT) has been performed by studying the expression of the AT phenotype in fused somatic cells or mixtures of cell-free extracts from different patients. Complementation of the defective response to ionizing radiation was observed frequently, considering four different parameters for radiosensitivity in AT. The combined results from studies on cultured fibroblasts or lymphoblastoid cells from 17 unrelated families revealed the presence of at least four and possibly nine complementation groups. These findings suggest that there is an extensive genetic heterogeneity in AT. More extensive studies are needed for an integration of these data and to provide a set of genetically characterized cell strains for future research of the AT genetic defect

  17. 78 FR 66700 - Toxic Substances Control Act Chemical Testing; Receipt of Test Data

    Science.gov (United States)

    2013-11-06

    ... additive for food Rat--Up-and-Down processing, and as Procedure. ingredient in aluminum Micronucleus Test... Toxicity to Fish; Acute Toxicity to Daphnia; Toxicity to Algae; Acute Toxicity to Mammals; Bacterial..., cold Study in Zebra Fish set, and sheet-fed (Brachydanio rerio). applications. Acute Toxicity Study in...

  18. Complementing the sugar code: role of GAGs and sialic acid in complement regulation

    Directory of Open Access Journals (Sweden)

    Alex eLangford-Smith

    2015-02-01

    Full Text Available Sugar molecules play a vital role on both microbial and mammalian cells, where they are involved in cellular communication, govern microbial virulence and modulate host immunity and inflammatory responses. The complement cascade, as part of a host’s innate immune system, is a potent weapon against invading bacteria but has to be tightly regulated to prevent inappropriate attack and damage to host tissues. A number of complement regulators, such as factor H and properdin, interact with sugar molecules, such as glycosaminoglycans and sialic acid, on host and pathogen membranes and direct the appropriate complement response by either promoting the binding of complement activators or inhibitors. The binding of these complement regulators to sugar molecules can vary from location to location, due to their different specificities and because distinct structural and functional subpopulations of sugars are found in different human organs, such as the brain, kidney and eye. This review will cover recent studies that have provided important new insights into the role of glycosaminoglycans and sialic acid in complement regulation and how sugar recognition may be compromised in disease

  19. Testing the usefulness of 222Rn to complement conventional hydrochemical data to trace groundwater provenance in complex multi-layered aquifers. Application to the Úbeda aquifer system (Jaén, SE Spain).

    Science.gov (United States)

    Ortega, L; Manzano, M; Rodríguez-Arévalo, J

    2017-12-01

    The Úbeda aquifer system is a multi-layered aquifer intensively exploited for irrigation. It covers 1100km 2 and consists of piled up sedimentary aquifer and aquitard layers from Triassic sandstones and clays at the bottom, to Jurassic carbonates (main exploited layer) in the middle, and Miocene sandstones and marls at the top. Flow network modification by intense exploitation and the existence of deep faults favour vertical mixing of waters from different layers and with distinct chemical composition. This induces quality loss and fosters risk of quantity restrictions. To support future groundwater abstraction management, a hydrogeochemical (major and some minor solutes) and isotopic ( 222 Rn) study was performed to identify the chemical signatures of the different layers and their mixing proportions in mixed samples. The study of 134 groundwater samples allowed a preliminary identification of hydrochemical signatures and mixtures, but the existence of reducing conditions in the most exploited sector prevents the utility of sulphate as a tracer of Triassic groundwater in the Jurassic boreholes. The potential of 222 Rn to establish isotopic signatures and to trace groundwater provenance in mixtures was tested. 222 Rn was measured in 48 samples from springs and boreholes in most aquifer layers. At first, clear correlations were observed between 222 Rn, Cl and SO 4 in groundwater. Afterwards, very good correlations were observed between 222 Rn and the chemical facies of the different layers established with End Member Mixing Analysis (EMMA). Using 222 Rn as part of the signatures, EMMA helped to identify end-member samples, and to quantify the mixing proportions of water from the Triassic and the Deep Miocene layers in groundwater pumped by deep agricultural wells screened in the Jurassic. The incorporation of 222 Rn to the study also allowed identifying the impact of irrigation returns through the association of moderate NO 3 , Cl, and Br contents with very low 222

  20. Functional assay of the alternative complement pathway of rat serum

    International Nuclear Information System (INIS)

    Coonrod, J.D.; Jenkins, S.D.

    1979-01-01

    Two functional assays of the alternative pathway of complement activation in rat serum were developed. In the first assay, conditions were established for titration of alternative pathway activity by use of the 50% hemolytic end-point of rabbit red blood cells (RaRBC) in serum treated with ethyleneglycol-bis-(beta-aminoethyl ether)-N, N'-tetraacetic acid (EGTA). The second assay of alternative pathway activity was based on the opsonization of heat-killed radiolabeled pneumococci of serotype 25 (Pn25). Opsonization of Pn25 was shown to proceed entirely via the alternative pathway in rat serum. There was excellent correlation between the results obtained with the RaRBC lysis test and those obtained with the opsonization test. Because of its technical simplicity, the RaRBC lysis test appeared to be the single most useful test of alternative pathway activity in rat serum. (Auth.)

  1. A novel method for direct measurement of complement convertases activity in human serum.

    Science.gov (United States)

    Blom, A M; Volokhina, E B; Fransson, V; Strömberg, P; Berghard, L; Viktorelius, M; Mollnes, T E; López-Trascasa, M; van den Heuvel, L P; Goodship, T H; Marchbank, K J; Okroj, M

    2014-10-01

    Complement convertases are enzymatic complexes that play a central role in sustaining and amplification of the complement cascade. Impairment of complement function leads directly or indirectly to pathological conditions, including higher infection rate, kidney diseases, autoimmune- or neurodegenerative diseases and ischaemia-reperfusion injury. An assay for direct measurement of activity of the convertases in patient sera is not available. Existing assays testing convertase function are based on purified complement components and, thus, convertase formation occurs under non-physiological conditions. We designed a new assay, in which C5 blocking compounds enabled separation of the complement cascade into two phases: the first ending at the stage of C5 convertases and the second ending with membrane attack complex formation. The use of rabbit erythrocytes or antibody-sensitized sheep erythrocytes as the platforms for convertase formation enabled easy readout based on measurement of haemolysis. Thus, properties of patient sera could be studied directly regarding convertase activity and membrane attack complex formation. Another advantage of this assay was the possibility to screen for host factors such as C3 nephritic factor and other anti-complement autoantibodies, or gain-of-function mutations, which prolong the half-life of complement convertases. Herein, we present proof of concept, detailed description and validation of this novel assay. © 2014 British Society for Immunology.

  2. Testing the effectiveness of an innovative information package on practitioner reported behaviour and beliefs: The UK Chiropractors, Osteopaths and Musculoskeletal Physiotherapists Low back pain ManagemENT (COMPLeMENT trial [ISRCTN77245761

    Directory of Open Access Journals (Sweden)

    Vogel Steven

    2005-07-01

    Full Text Available Abstract Background Low back pain (LBP is a common and costly problem. Initiatives designed to assist practitioner and patient decisions about appropriate healthcare for LBP include printed evidence-based clinical guidelines. The three professional groups of chiropractic, osteopathy and musculoskeletal physiotherapy in the UK share common ground with their approaches to managing LBP and are amongst those targeted by LBP guidelines. Even so, many seem unaware that such guidelines exist. Furthermore, the behaviour of at least some of these practitioners differs from that recommended in these guidelines. Few randomised controlled trials evaluating printed information as an intervention to change practitioner behaviour have utilised a no-intervention control. All these trials have used a cluster design and most have methodological flaws. None specifically focus upon practitioner behaviour towards LBP patients. Studies that have investigated other strategies to change practitioner behaviour with LBP patients have produced conflicting results. Although numerous LBP guidelines have been developed worldwide, there is a paucity of data on whether their dissemination actually changes practitioner behaviour. Primarily because of its low unit cost, sending printed information to large numbers of practitioners is an attractive dissemination and implementation strategy. The effect size of such a strategy, at an individual practitioner level, is likely to be small. However, if large numbers of practitioners are targeted, this strategy might achieve meaningful changes at a population level. Methods The primary aim of this prospective, pragmatic randomised controlled trial is to test the short-term effectiveness (six-months following intervention of a directly-posted information package on the reported clinical behaviour (primary outcome, attitudes and beliefs of UK chiropractors, osteopaths and musculoskeletal physiotherapists. We sought to randomly allocate a

  3. Genetic Association of the Porcine C9 Complement Component with Hemolytic Complement Activity

    Directory of Open Access Journals (Sweden)

    D. V. A. Khoa

    2015-09-01

    Full Text Available The complement system is a part of the natural immune regulation mechanism against invading pathogens. Complement activation from three different pathways (classical, lectin, and alternative leads to the formation of C5-convertase, an enzyme for cleavage of C5 into C5a and C5b, followed by C6, C7, C8, and C9 in membrane attack complex. The C9 is the last complement component of the terminal lytic pathway, which plays an important role in lysis of the target cells depending on its self-polymerization to form transmembrane channels. To address the association of C9 with traits related to disease resistance, the complete porcine C9 cDNA was comparatively sequenced to detect single nucleotide polymorphisms (SNPs in pigs of the breeds Hampshire (HS, Duroc (DU, Berlin miniature pig (BMP, German Landrace (LR, Pietrain (PIE, and Muong Khuong (Vietnamese potbelly pig. Genotyping was performed in 417 F2 animals of a resource population (DUMI: DU×BMP that were vaccinated with Mycoplasma hyopneumoniae, Aujeszky diseases virus and porcine respiratory and reproductive syndrome virus at 6, 14 and 16 weeks of age, respectively. Two SNPs were detected within the third exon. One of them has an amino acid substitution. The European porcine breeds (LR and PIE show higher allele frequency of these SNPs than Vietnamese porcine breed (MK. Association of the substitution SNP with hemolytic complement activity indicated statistically significant differences between genotypes in the classical pathway but not in the alternative pathway. The interactions between eight time points of measurement of complement activity before and after vaccinations and genotypes were significantly different. The difference in hemolytic complement activity in the both pathways depends on genotype, kind of vaccine, age and the interaction to the other complement components. These results promote the porcine C9 (pC9 as a candidate gene to improve general animal health in the future.

  4. Acute antibody-mediated rejection of skin grafts without involvement of granulocytes or complement

    International Nuclear Information System (INIS)

    Bogman, M.J.; Cornelissen, I.M.; Koene, R.A.

    1984-01-01

    In immunosuppressed mice that carry rat skin xeno-grafts, acute antibody-mediated graft rejection (AAR) can be induced by intravenous administration of mouse anti-rat globulin. Dependent on the amount of antibody injected and on the complement status of the recipient, an Arthus-like or a Shwartzman-like pattern of vasculitis occurs. The role of polymorphonuclear granulocytes (PMNs) in either type of vasculitis was tested by inducing AAR in recipients depleted of PMNs by total body irradiation. Despite the absence of PMNs in the graft vessels, AAR occurred both in the Arthus-like and in the Shwartzman-like type. Moreover, AAR could be elicited in PMN-depleted recipients that were complement-depleted by cobra venom factor treatment or were congenitally C5-deficient. We conclude that neither the PMN nor complement is an essential mediator the PMN nor complement is an essential mediator in this form of antibody-mediated vasculitis

  5. Language and Theory of Mind in Autism Spectrum Disorder: The Relationship between Complement Syntax and False Belief Task Performance

    Science.gov (United States)

    Lind, Sophie E.; Bowler, Dermot M.

    2009-01-01

    This study aimed to test the hypothesis that children with autism spectrum disorder (ASD) use their knowledge of complement syntax as a means of "hacking out" solutions to false belief tasks, despite lacking a representational theory of mind (ToM). Participants completed a "memory for complements" task, a measure of receptive vocabulary, and…

  6. Genetic, molecular and functional analyses of complement factor I deficiency

    DEFF Research Database (Denmark)

    Nilsson, S.C.; Trouw, L.A.; Renault, N.

    2009-01-01

    Complete deficiency of complement inhibitor factor I (FI) results in secondary complement deficiency due to uncontrolled spontaneous alternative pathway activation leading to susceptibility to infections. Current genetic examination of two patients with near complete FI deficiency and three patie...

  7. Use of the fluorescent micronucleus assay to detect the genotoxic effects of radiation and arsenic exposure in exfoliated human epithelial cells

    International Nuclear Information System (INIS)

    Moore, L.E.; Warner, M.L.; Smith, A.H.

    1996-01-01

    The exfoliated cell micronucleus (MN) assay using fluorescent in situ hybridization (FISH) with a centromeric probe is a rapid method for determining the mechanism of MN formation in epithelial tissues exposed to carcinogenic agents. Here, we describe the use of this assay to detect the presence or absence of centromeric DNA in MN induced in vivo by radiation therapy and chronic arsenic (As) ingestion. We examined the buccal cells of an individual receiving 6,500 rads of photon radiation to the head and neck. Exfoliated cells were collected before, during, and after treatment. After radiation exposure a 16.6-fold increase in buccal cell MN frequency was seen. All induced MN were centromere negative (MN-) resulting from chromosome breakage. This finding is consistent with the clastogenic action of radiation and confirmed the reliability of the method. Three weeks post-therapy, MN frequencies returned to baseline. The assay was used on 18 people chronically exposed to high levels of inorganic arsenic (In-As) in drinking water (average level, 1,312 μg As/L) and 18 matched controls (average level, 16 μg As/L). The combined increase in MN frequency was 1.8-fold (P = 0.001, Fisher's exact test). Frequencies of micronuclei containing acentric fragments (MN-) and those containing whole chromosomes (MN+) both increased, suggesting that arsenic may have both clastogenic and weak aneuploidogenic properties in vivo. After stratification on sex, the effect was stronger in male than in female bladder cells. In males the MN-frequency increased 2.06-fold (P =0.07) while the frequency of MN+ increased 1.86-fold (P = 0.08). In addition, the frequencies of MN and MN+ were positively associated with urinary arsenic and its metabolites. The association was stronger for micronuclei containing acentric fragments. By using FISH with centromeric probes, the mechanism of chemically induced genotoxicity can not be determined in epithelial tissues. 35 refs., 4 tabs

  8. Nongenotoxic effects and a reduction of the DXR-induced genotoxic effects of Helianthus annuus Linné (sunflower) seeds revealed by micronucleus assays in mouse bone marrow.

    Science.gov (United States)

    Boriollo, Marcelo Fabiano Gomes; Souza, Luiz Silva; Resende, Marielly Reis; Silva, Thaísla Andrielle da; Oliveira, Nelma de Mello Silva; Resck, Maria Cristina Costa; Dias, Carlos Tadeu dos Santos; Fiorini, João Evangelista

    2014-04-02

    This research evaluated the genotoxicity of oil and tincture of H. annuus L. seeds using the micronucleus assay in bone marrow of mice. The interaction between these preparations and the genotoxic effects of doxorubicin (DXR) was also analysed (antigenotoxicity test). Experimental groups were evaluated at 24-48 h post treatment with N-Nitroso-N-ethylurea (positive control - NEU), DXR (chemotherapeutic), NaCl (negative control), a sunflower tincture (THALS) and two sources of sunflower oils (POHALS and FOHALS). Antigenotoxic assays were carried out using the sunflower tincture and oils separately and in combination with NUE or DXR. For THALS, analysis of the MNPCEs showed no significant differences between treatment doses (250-2,000 mg.Kg-1) and NaCl. A significant reduction in MNPCE was observed when THALS (2,000 mg.Kg-1) was administered in combination with DXR (5 mg.Kg-1). For POHALS or FOHALS, analysis of the MNPCEs also showed no significant differences between treatment doses (250-2,000 mg.Kg-1) and NaCl. However, the combination DXR + POHALS (2,000 mg.Kg-1) or DXR + FOHALS (2,000 mg.Kg-1) not contributed to the MNPCEs reduction. This research suggests absence of genotoxicity of THALS, dose-, time- and sex-independent, and its combination with DXR can reduce the genotoxic effects of DXR. POHALS and FOHALS also showed absence of genotoxicity, but their association with DXR showed no antigenotoxic effects.

  9. Cytogenetic Monitoring By Use Of The Micronucleus Assay Among Nuclear Malaysia Radiation Workers-A Preliminary Result

    International Nuclear Information System (INIS)

    Rahimah Abdul Rahim; Mohd Rodzi Ali; Noraisyah Mohd Yusof; Juliana Mahamad Napiah; Yahaya Talib; Rehir Dahalan

    2014-01-01

    Biological dosimetry based on the analysis of micronuclei in the cytokinesis-block micronucleus (CBMN) assay can be used as an alternative method for scoring dicentric chromosomes in the field of radiation protection. Bio dosimetry is mainly performed, in addition to physical dosimetry, with the aim of individual dose assessment. Aim of this study was to assess occupationally induced chromosomal damage in radiation workers exposed to ionizing radiation. The CBMN assay was used in the peripheral blood lymphocytes of 50 exposed workers. Number of bi-nucleated cell and micronuclei were scored and statistical analysis was done to see the effect and correlation of micronuclei with gender, age and time of worked. In conclusion, scoring of micronuclei is a useful cytogenetic monitoring for radiation workers. (author)

  10. Does Host Complement Kill Borrelia burgdorferi within Ticks?

    OpenAIRE

    Rathinavelu, Sivaprakash; Broadwater, Anne; de Silva, Aravinda M.

    2003-01-01

    The Lyme disease spirochete, Borrelia burgdorferi, inhabits the gut lumen of the tick vector. At this location the spirochete is exposed to host blood when a tick feeds. We report here on studies that were done with normal and complement-deficient (C3-knockout) mice to determine if the host complement system killed spirochetes within the vector. We found that spirochete numbers within feeding nymphs were not influenced by complement, most likely because host complement was inactivated within ...

  11. Fish eco-genotoxicology: Comet and micronucleus assay in fish erythrocytes as in situ biomarker of freshwater pollution

    Directory of Open Access Journals (Sweden)

    Bilal Hussain

    2018-02-01

    Full Text Available Owing to white meat production Labeo rohita have vast economic importance, but its population has been reduced drastically in River Chenab due to pollution. Atomic absorption spectrophotometry showed a merciless toxicity level of Cd, Cu, Mn, Zn, Pb, Cr, Sn and Hg. Comet assay results indicated significant (p < .05 DNA fragmentation in Labeo rohita as 42.21 ± 2.06%, 31.26 ± 2.41% and 21.84 ± 2.21% DNA in comet tail, tail moment as 17.71 ± 1.79, 10.30 ± 1.78 and 7.81 ± 1.56, olive moment as 13.58 ± 1.306, 8.10 ± 1.04 and 5.88 ± 0.06, respectively, from three different polluted sites on the river. Micronucleus assay showed similar findings of single micronucleus induction (MN as 50.00 ± 6.30‰, double MN 14.40 ± 2.56‰, while nuclear abnormalities (NA were found as 150.00 ± 2.92‰. These higher frequencies of MN induction and NA were found to be the cause of reduction of 96% of the population of this fish species in an experimental area of the River Chenab. This fish species has been found near extinction through the length of the river Chenab and few specimens in rainy seasons if restored by flood, may die in sugarcane mill season. Due to sweeping extinction Labeo rohita showed the highest sensitivity for pollution and could be used as bioindicator and DNA fragmentation in this column feeder fish species as a biomarker of the pollution load in freshwater bodies.

  12. The buccal cytome and micronucleus frequency is substantially altered in Down's syndrome and normal ageing compared to young healthy controls

    International Nuclear Information System (INIS)

    Thomas, Philip; Harvey, Sarah; Gruner, Tini; Fenech, Michael

    2008-01-01

    The buccal micronucleus cytome assay was used to investigate biomarkers for DNA damage, cell death and basal cell frequency in buccal cells of healthy young, healthy old and young Down's syndrome cohorts. With normal ageing a significant increase in cells with micronuclei (P < 0.05, average increase +366%), karyorrhectic cells (P < 0.001, average increase +439%), condensed chromatin cells (P < 0.01, average increase +45.8%) and basal cells (P < 0.001, average increase +233%) is reported relative to young controls. In Down's syndrome we report a significant increase in cells with micronuclei (P < 0.001, average increase +733%) and binucleated cells (P < 0.001, average increase +84.5%) and a significant decrease in condensed chromatin cells (P < 0.01, average decrease -52%), karyolytic cells (P < 0.001, average decrease -51.8%) and pyknotic cells (P < 0.001, average decrease -75.0%) relative to young controls. These changes show distinct differences between the cytome profile of normal ageing relative to that for a premature ageing syndrome, and highlight the diagnostic value of the cytome approach for measuring the profile of cells with DNA damage, cell death and proportion of cells with proliferative potential (i.e., basal cells). Significant correlations amongst cell death biomarkers observed in this study were used to propose a new model of the inter-relationship of cell types scored within the buccal micronucleus cytome assay. This study validates the use of a cytome approach to investigate DNA damage, cell death and cell proliferation in buccal cells with ageing

  13. The paralogous salivary anti-complement proteins IRAC I and IRAC II encoded by Ixodes ricinus ticks have broad and complementary inhibitory activities against the complement of different host species.

    Science.gov (United States)

    Schroeder, Hélène; Daix, Virginie; Gillet, Laurent; Renauld, Jean-Christophe; Vanderplasschen, Alain

    2007-02-01

    Several observations suggest that inhibition of the host complement alternative pathway by Ixodes tick saliva is crucial to achieve blood feeding. We recently described two paralogous anti-complement proteins called Ixodes ricinus anti-complement (IRAC) proteins I and II co-expressed in I. ricinus salivary glands. Phylogenetic analyses suggested that these sequences were diversifying by a process of positive Darwinian selection, possibly leading to molecules with different biological properties. In the present study, we tested the hypothesis that each paralogue may have different inhibitory activities against the complement of different natural host species, thereby contributing to broaden the host range of I. ricinus ticks. IRAC I and IRAC II were tested against the complement of eight I. ricinus natural host species (six mammals and two birds). The results demonstrate that IRAC I and IRAC II have broad and complementary inhibition activities against the complement of different host species. This report is the first description of paralogous anti-complement molecules encoded by a pathogen with broad and complementary inhibitory activities against the complement of different host species.

  14. High-throughput selection for cellulase catalysts using chemical complementation.

    Science.gov (United States)

    Peralta-Yahya, Pamela; Carter, Brian T; Lin, Hening; Tao, Haiyan; Cornish, Virginia W

    2008-12-24

    Efficient enzymatic hydrolysis of lignocellulosic material remains one of the major bottlenecks to cost-effective conversion of biomass to ethanol. Improvement of glycosylhydrolases, however, is limited by existing medium-throughput screening technologies. Here, we report the first high-throughput selection for cellulase catalysts. This selection was developed by adapting chemical complementation to provide a growth assay for bond cleavage reactions. First, a URA3 counter selection was adapted to link chemical dimerizer activated gene transcription to cell death. Next, the URA3 counter selection was shown to detect cellulase activity based on cleavage of a tetrasaccharide chemical dimerizer substrate and decrease in expression of the toxic URA3 reporter. Finally, the utility of the cellulase selection was assessed by isolating cellulases with improved activity from a cellulase library created by family DNA shuffling. This application provides further evidence that chemical complementation can be readily adapted to detect different enzymatic activities for important chemical transformations for which no natural selection exists. Because of the large number of enzyme variants that selections can now test as compared to existing medium-throughput screens for cellulases, this assay has the potential to impact the discovery of improved cellulases and other glycosylhydrolases for biomass conversion from libraries of cellulases created by mutagenesis or obtained from natural biodiversity.

  15. Mutations in complement regulatory proteins predispose to preeclampsia: a genetic analysis of the PROMISSE cohort.

    Directory of Open Access Journals (Sweden)

    Jane E Salmon

    2011-03-01

    Full Text Available Pregnancy in women with systemic lupus erythematosus (SLE or antiphospholipid antibodies (APL Ab--autoimmune conditions characterized by complement-mediated injury--is associated with increased risk of preeclampsia and miscarriage. Our previous studies in mice indicate that complement activation targeted to the placenta drives angiogenic imbalance and placental insufficiency.We use PROMISSE, a prospective study of 250 pregnant patients with SLE and/or APL Ab, to test the hypothesis in humans that impaired capacity to limit complement activation predisposes to preeclampsia. We sequenced genes encoding three complement regulatory proteins--membrane cofactor protein (MCP, complement factor I (CFI, and complement factor H (CFH--in 40 patients who had preeclampsia and found heterozygous mutations in seven (18%. Five of these patients had risk variants in MCP or CFI that were previously identified in atypical hemolytic uremic syndrome, a disease characterized by endothelial damage. One had a novel mutation in MCP that impairs regulation of C4b. These findings constitute, to our knowledge, the first genetic defects associated with preeclampsia in SLE and/or APL Ab. We confirmed the association of hypomorphic variants of MCP and CFI in a cohort of non-autoimmune preeclampsia patients in which five of 59 were heterozygous for mutations.The presence of risk variants in complement regulatory proteins in patients with SLE and/or APL Ab who develop preeclampsia, as well as in preeclampsia patients lacking autoimmune disease, links complement activation to disease pathogenesis and suggests new targets for treatment of this important public health problem.ClinicalTrials.gov NCT00198068.

  16. Hijacking Complement Regulatory Proteins for Bacterial Immune Evasion.

    Science.gov (United States)

    Hovingh, Elise S; van den Broek, Bryan; Jongerius, Ilse

    2016-01-01

    The human complement system plays an important role in the defense against invading pathogens, inflammation and homeostasis. Invading microbes, such as bacteria, directly activate the complement system resulting in the formation of chemoattractants and in effective labeling of the bacteria for phagocytosis. In addition, formation of the membrane attack complex is responsible for direct killing of Gram-negative bacteria. In turn, bacteria have evolved several ways to evade complement activation on their surface in order to be able to colonize and invade the human host. One important mechanism of bacterial escape is attraction of complement regulatory proteins to the microbial surface. These molecules are present in the human body for tight regulation of the complement system to prevent damage to host self-surfaces. Therefore, recruitment of complement regulatory proteins to the bacterial surface results in decreased complement activation on the microbial surface which favors bacterial survival. This review will discuss recent advances in understanding the binding of complement regulatory proteins to the bacterial surface at the molecular level. This includes, new insights that have become available concerning specific conserved motives on complement regulatory proteins that are favorable for microbial binding. Finally, complement evasion molecules are of high importance for vaccine development due to their dominant role in bacterial survival, high immunogenicity and homology as well as their presence on the bacterial surface. Here, the use of complement evasion molecules for vaccine development will be discussed.

  17. Masturbation and Partnered Sex: Substitutes or Complements?

    Science.gov (United States)

    Regnerus, Mark; Price, Joseph; Gordon, David

    2017-10-01

    Drawing upon a large, recent probability sample of American adults ages 18-60 (7648 men and 8090 women), we explored the association between sexual frequency and masturbation, evaluating the evidence for whether masturbation compensates for unavailable sex, complements (or augments) existing paired sexual activity, or bears little association with it. We found evidence supporting a compensatory relationship between masturbation and sexual frequency for men, and a complementary one among women, but each association was both modest and contingent on how content participants were with their self-reported frequency of sex. Among men and women, both partnered status and their sexual contentment were more obvious predictors of masturbation than was recent frequency of sex. We conclude that both hypotheses as commonly evaluated suffer from failing to account for the pivotal role of subjective sexual contentment in predicting masturbation.

  18. Endogenous Natural Complement Inhibitor Regulates Cardiac Development

    DEFF Research Database (Denmark)

    Mortensen, Simon A; Skov, Louise L; Kjaer-Sorensen, Kasper

    2017-01-01

    mechanisms during fetal development and adult homeostasis. In this article, we describe the function of an endogenous complement inhibitor, mannan-binding lectin (MBL)-associated protein (MAp)44, in regulating the composition of a serine protease-pattern recognition receptor complex, MBL-associated serine...... of MAp44 caused impaired cardiogenesis, lowered heart rate, and decreased cardiac output. These defects were associated with aberrant neural crest cell behavior. We found that MAp44 competed with MASP-3 for pattern recognition molecule interaction, and knockdown of endogenous MAp44 expression could...... be rescued by overexpression of wild-type MAp44. Our observations provide evidence that immune molecules are centrally involved in the orchestration of cardiac tissue development....

  19. Interpain A, a cysteine proteinase from Prevotella intermedia, inhibits complement by degrading complement factor C3.

    Directory of Open Access Journals (Sweden)

    Michal Potempa

    2009-02-01

    Full Text Available Periodontitis is an inflammatory disease of the supporting structures of the teeth caused by, among other pathogens, Prevotella intermedia. Many strains of P. intermedia are resistant to killing by the human complement system, which is present at up to 70% of serum concentration in gingival crevicular fluid. Incubation of human serum with recombinant cysteine protease of P. intermedia (interpain A resulted in a drastic decrease in bactericidal activity of the serum. Furthermore, a clinical strain 59 expressing interpain A was more serum-resistant than another clinical strain 57, which did not express interpain A, as determined by Western blotting. Moreover, in the presence of the cysteine protease inhibitor E64, the killing of strain 59 by human serum was enhanced. Importantly, we found that the majority of P. intermedia strains isolated from chronic and aggressive periodontitis carry and express the interpain A gene. The protective effect of interpain A against serum bactericidal activity was found to be attributable to its ability to inhibit all three complement pathways through the efficient degradation of the alpha-chain of C3 -- the major complement factor common to all three pathways. P. intermedia has been known to co-aggregate with P. gingivalis, which produce gingipains to efficiently degrade complement factors. Here, interpain A was found to have a synergistic effect with gingipains on complement degradation. In addition, interpain A was able to activate the C1 complex in serum, causing deposition of C1q on inert and bacterial surfaces, which may be important at initial stages of infection when local inflammatory reaction may be beneficial for a pathogen. Taken together, the newly characterized interpain A proteinase appears to be an important virulence factor of P. intermedia.

  20. Evaluation of DNA by the micronucleus test of the samples Allium cepa germinated in the presence of uranium

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Ayrton Nascimento de; Oliveira, Andressa L.; Gennari, Roseli F.; Maffei, Eliane M.D.; Campos, Simara S., E-mail: simaracampos@gmail.com [Universidade Estadual do Sudoeste da Bahia (UESB), Vitoria da Conquista, BA, (Brazil). Departamento de Ciencias Exatas e Tecnologicas; Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Instituto de Fisica. Departamento de Fisica Nuclear

    2017-11-01

    Although Brazil composes the seventh position in the world ranking of uranium reserves, the ore is still little explored in Brazil, considering its vast existing arsenal. On the one hand, despite nuclear energy has brought great benefits, technological and socio-economic development, it generates controversy about environmental contamination and risks to public health. Studies on this subject indicate that areas where uranium ore concentration is high, natural environmental radiation exposure levels are already higher than in other regions. The aim of this study is to observe the simple germination of the bio-indicator (Allium cepa), typically used to assess potential chromosomal aberrations, suffer any adverse effect caused by natural radiation uranium. The choice of this bio-indicator is based on its potential for evaluating the mutation caused by innumerous chemical compounds. Four treatments with three replicates were designed. In each treatment, 10 seeds of onion A. cepa without any pesticides were packed in the Petri dish lined with germination paper and room temperature (25°C) was kept until the root reaches approximately 1cm long and 0, 5 g of the U. As a result 3000 cells were counted during the interphase, and structural changes were observed in the chromosomes, elongated nuclei and loose chromosomes of the spindle fiber, concluding that U possibly affected the cell cycle da Allium cepa. (author)

  1. Assessment of the mutagenic and antimutagenic activity of Synadenium umbellatum Pax latex by micronucleus test in mice

    Directory of Open Access Journals (Sweden)

    PR. Melo-Reis

    Full Text Available Synadenium umbellatum Pax, popularly known as "cola-nota", is a medicinal plant that grows in tropical regions. The latex of this plant is used against various diseases, such as diabetes mellitus, leprosy, tripanosomiasis, leukemia, and several malignant tumors. The mutagenic, antimutagenic, and cytotoxic effects of the latex of this plant were investigated by measuring the frequency of micronuclei in mice bone marrow cells. To evaluate mutagenicity, the animals were treated with four doses of latex (10, 30, 50, and 100 mg/kg body weight. To study the antimutagenic activity, the animals were simultaneously treated with latex and mitomycin C (4 mg/kg. The cytotoxicity was evaluated by polychromatic and normochromatic erythrocytes ratio. Our results showed a significant increase of frequency of micronucleated polychromatic erythrocytes (MNPCE compared to the negative control group (p 0.05 was detected at the doses of 50 and 100 mg/kg. Under our experimental conditions, the results obtained indicate strong mutagenic and cytotoxic activity of S. umbellatum latex except the dose of 10 mg/kg and moderate antimutagenic effect at lower doses.

  2. Comparison of radiation sensitivity for three cell lines as measured by the cloning assay and the micro-nucleus test

    NARCIS (Netherlands)

    Stap, J.; Aten, J. A.

    1990-01-01

    The correlation between cell killing and the induction of micro-nuclei was studied for three cell lines after treatment with gamma radiation to investigate whether the frequency of micro-nucleated cells can be used to determine the radiation sensitivity of a cell type. R1 rat rhabdomyosarcoma cells

  3. DNA Damage Potential of Engine Emissions Measured In Vitro by Micronucleus Test in Human Bronchial Epithelial Cells

    Czech Academy of Sciences Publication Activity Database

    Červená, Tereza; Rössnerová, Andrea; Sikorová, Jitka; Beránek, V.; Vojtíšek-Lom, M.; Cigánek, M.; Topinka, Jan; Rössner ml., Pavel

    2017-01-01

    Roč. 121, SI (2017), s. 102-108 ISSN 1742-7835 R&D Projects: GA MŠk(CZ) LO1508; GA MŠk(CZ) LM2015073; GA ČR(CZ) GA13-01438S Institutional support: RVO:68378041 Keywords : saliva DNA * methylation patterns * cancer-patients Subject RIV: DN - Health Impact of the Environment Quality OBOR OECD: Public and environmental health Impact factor: 3.176, year: 2016

  4. Evaluation of DNA by the micronucleus test of the samples Allium cepa germinated in the presence of uranium

    International Nuclear Information System (INIS)

    Souza, Ayrton Nascimento de; Oliveira, Andressa L.; Gennari, Roseli F.; Maffei, Eliane M.D.; Campos, Simara S.; Universidade de Sao Paulo

    2017-01-01

    Although Brazil composes the seventh position in the world ranking of uranium reserves, the ore is still little explored in Brazil, considering its vast existing arsenal. On the one hand, despite nuclear energy has brought great benefits, technological and socio-economic development, it generates controversy about environmental contamination and risks to public health. Studies on this subject indicate that areas where uranium ore concentration is high, natural environmental radiation exposure levels are already higher than in other regions. The aim of this study is to observe the simple germination of the bio-indicator (Allium cepa), typically used to assess potential chromosomal aberrations, suffer any adverse effect caused by natural radiation uranium. The choice of this bio-indicator is based on its potential for evaluating the mutation caused by innumerous chemical compounds. Four treatments with three replicates were designed. In each treatment, 10 seeds of onion A. cepa without any pesticides were packed in the Petri dish lined with germination paper and room temperature (25°C) was kept until the root reaches approximately 1cm long and 0, 5 g of the U. As a result 3000 cells were counted during the interphase, and structural changes were observed in the chromosomes, elongated nuclei and loose chromosomes of the spindle fiber, concluding that U possibly affected the cell cycle da Allium cepa. (author)

  5. Changes of chromosome aberration rate and micronucleus frequency along with accumulated dose in continuously irradiated mice with a low dose rate of γ-rays

    International Nuclear Information System (INIS)

    Tanaka, Kimio; Izumi, Jun; Yanai, Takanori; Ichinohe, Kazuaki; Matsumoto, Tsuneya

    2003-01-01

    Chromosome aberrations in chronically exposed workers in nuclear facilities and medical radiologists have been reported. However chronological change of chromosome aberration rates along with accumulated dose has not been well studied. Chromosome aberrations and micronuclei in spleen lymphocytes were observed serially in mice continuously irradiated with a low dose rate of 20 mGy/day up to 400 days. Chromosome aberration rates were rapidly increased to 11.1% at 1 Gy, while micronucleus incidence increased at 5 Gy. After these doses their increase rates were saturated. Micronucleus incidence in bone marrow erythroblasts was higher than in spleen cells. These chronological changes of cytogenetic aberrations seem to be induced through a balance between developments of chromosome aberrations and micronuclei, and life span of spleen lymphocytes. These results will be helpful for risk assessment in low dose rate radiation exposure. (author)

  6. Use of the micronucleus assay for the selective detection of radiosensitivity in BUdR-unincorporated cells after pulse-labelling of exponentially growing tumour cells

    Energy Technology Data Exchange (ETDEWEB)

    Masunaga, S.; Ono, K.; Fushiki, M.; Abe, M. (Kyoto Univ. (Japan). Faculty of Medicine); Wandl, E.O. (Vienna Univ. (Austria). Klinik fuer Strahlentherapie und Strahlenbiologie)

    1990-08-01

    To determine the radiosensitivity of non S-phase tumour cells in vitro, survival curves of SCC VII tumour cells were obtained after a short block with hydroxyurea. Dose-response curves of micronucleus (MN) frequency appearing in non-S-phase cells were also determined by excluding S-phase cells with immunofluorescence staining to 5-bromo-2'-deoxyuridine (BUdR). Both the dose response curves of MN frequency and survival curves were analysed by a linear-quadratic model (surviving fraction =exp (-{alpha}D-{beta}D{sup 2}), MN frequency =aD+bD{sup 2}+c). A good correlation between the {alpha}/{beta} and a/b ratios was observed. In both BUdR-unincorporated and asynchronous cell cultures, the regression lines between the surviving fraction and micronucleus frequency were statistically identical. (author).

  7. Complement-mediated solubilization of immune complexes and their interaction with complement C3 receptors

    DEFF Research Database (Denmark)

    Petersen, Ivan; Baatrup, Gunnar; Jepsen, H H

    1985-01-01

    Some of the molecular events in the complement (C)-mediated solubilization of immune complexes (IC) have been clarified in recent years. The solubilization is primarily mediated by alternative C pathway proteins whereas factors in the classical pathway accelerate the process. Components of the me......Some of the molecular events in the complement (C)-mediated solubilization of immune complexes (IC) have been clarified in recent years. The solubilization is primarily mediated by alternative C pathway proteins whereas factors in the classical pathway accelerate the process. Components...... of the cellular localization, expression and structure of the C3 receptors, especially the C3b (CR1) receptor, has been considerably extended in the last few years, whereas our understanding of the physiological role of these receptors is still fragmentary. However, it is becoming increasingly evident...

  8. [Fanconi Anemia, Complementation Group D1 Caused by Biallelic Mutations of BRCA2 Gene--Case Report].

    Science.gov (United States)

    Puchmajerová, A; Švojgr, K; Novotná, D; Macháčková, E; Sumerauer, D; Smíšek, P; Kodet, R; Kynčl, M; Křepelová, A; Foretová, L

    2016-01-01

    Fanconi anemia is a rare autosomal recessive disorder, clinically and genetically heterogeneous, characterized by typical clinical features, such as short stature, microcephaly, skeletal abnormalities, abnormal skin pigmentations, developmental delay and congenital heart, kidney anomalies etc. Pancytopenia leading to bone marrow failure occurs in the first decade. Patients with Fanconi anemia have a high risk of hematologic malignancies and solid tumors. The diagnosis of Fanconi anemia is based on cytogenetic testing for increased rates of spontaneous chromosomal breakage and increased sensitivity to diepoxybutane or mitomycin C. Fanconi anemia is a heterogeneous disorder, at least 15 complementation groups are described, and 15 genes in which mutations are responsible for all of the 15 Fanconi anemia complementation groups have been identified. Unlike other Fanconi anemia complementation groups, for complementation group D1 (FANCD1), the bone marrow failure is not a typical feature, but early-onset leukemia and specific solid tumors, most often medulloblastoma and Wilms tumor, are typical for this complementation group.

  9. Serum complement changes during double-blind food challenges in children with a history of food sensitivity.

    Science.gov (United States)

    Martin, M E; Guthrie, L A; Bock, S A

    1984-04-01

    Serum levels of C3, C4, factor B, properdin, total hemolytic complement and alternative-pathway hemolytic activity were measured before and after double-blind food challenge in 23 children with impressive histories of adverse reactions to foods. The 23 subjects had 11 positive food challenges and 12 negative food challenges. Nine patients with reagin-mediated positive food challenges showed increases in all six complement assays after double-blind food challenge, while the group with negative food challenges showed decreases in five of the six assays. The difference between the two groups for complement changes after double-blind food challenge was significant only for the alternative-pathway assay. Individual subject analysis revealed markedly heterogeneous changes in direction and magnitude within both groups for all complement assays. Therefore, it is concluded that measurement of serum complement levels is not a useful test for the clinical evaluation of a patient with suspected food sensitivity.

  10. Marketplace Clinics Complementing Diabetes Care for Urban Residing American Indians.

    Science.gov (United States)

    Rick, Robert; Hoye, Robert E; Thron, Raymond W; Kumar, Vibha

    2017-10-01

    For several decades, the Minneapolis American Indian population has experienced limited health care access and threefold diabetes health disparity. As part of an urban health initiative, the marketplace clinics located in nearby CVS, Target, and Supervalu stores committed financial support, providers, certified educators, and pharmacy staff for a community-based diabetes support group. To measure the extent to which collaborating marketplace clinics and the community-based support group expanded diabetes care and provided self-management education for this largely urban Indian neighborhood. A controlled quasi-experimental study and 3-years retrospective analysis of secondary data were used to test whether the Minneapolis marketplace clinics and the community diabetes support group participants (n = 48) had improved diabetes health outcomes relative to the comparison group (n = 87). The marketplace complemented intervention group employed motivational interviewing and the patient activation measure (PAM®) in coaching diabetes self-care and behavioral modification. The federally funded comparison group received only basic self-management education. T tests and effect sizes were used to quantify the difference between the study intervention and comparison groups. Statistical significance was determined for the following outcome variables: A1C ( P < .01), body mass index ( P < .04), and PAM® ( P < .001). Includes strengths, limitations, and future study recommendations. Positive effects of marketplace clinics and community health complementation were found with regard to improved blood glucose control, weight loss, and healthful lifestyle adaptation. Primary care and community health improvements could be realized by incorporating patient activation with diabetes prevention programs for the urban Indian two-thirds majority of the United States 5 million American Indian population.

  11. HUMN project initiative and review of validation, quality control and prospects for further development of automated micronucleus assays using image cytometry systems

    Czech Academy of Sciences Publication Activity Database

    Fenech, M.; Kirsch-Volders, M.; Rössnerová, Andrea; Šrám, Radim; Romm, H.; Bolognesi, C.; Ramakumar, A.; Soussaline, F.; Schunck, CH.; Elhajouji, A.; Anwar, W.; Bonassi, S.

    2013-01-01

    Roč. 216, č. 5 (2013), s. 541-552 ISSN 1438-4639 R&D Projects: GA ČR GAP503/11/0084 Grant - others:Project NewGenesis(XE) FOOD -CT-2005-016320 Institutional support: RVO:68378041 Keywords : Micronucleus * Cytokinesis-block * Automation Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 3.276, year: 2013

  12. Mobile MSN Messenger: Still a Complement?

    Directory of Open Access Journals (Sweden)

    Marcus Nyberg

    2008-10-01

    Full Text Available In order to understand how mobile instant messaging services can fit into the users’ current communication behavior, Ericsson Research performed a qualitative user study in Sweden in May 2007. The results showed that the respondents were positive towards (free of charge mobile MSN Messenger and perceived it as an ex¬tension of the computer-based version that could be used anywhere. However, although MSN Messenger on the com¬puter definitely was considered as a ‘must-have’ application, the mobile version was only perceived as a ‘nice-to-have’ application and a complement to text mes¬saging (SMS. Almost one year later, in April 2008, Ericsson Research performed a short qualita¬tive follow-up study with the same set of respondents to un¬derstand if and how the mobile MSN Messenger usage had changed. The results actually revealed that none of the re¬spondents used mobile MSN Messenger anymore as the application no longer was free of charge. On a general level, the study highlights important considera¬tions when intro¬ducing computer-based concepts and Internet services in a mo¬bile environment.

  13. Complement, a target for therapy in inflammatory and degenerative diseases.

    Science.gov (United States)

    Morgan, B Paul; Harris, Claire L

    2015-12-01

    The complement system is a key innate immune defence against infection and an important driver of inflammation; however, these very properties can also cause harm. Inappropriate or uncontrolled activation of complement can cause local and/or systemic inflammation, tissue damage and disease. Complement provides numerous options for drug development as it is a proteolytic cascade that involves nine specific proteases, unique multimolecular activation and lytic complexes, an arsenal of natural inhibitors, and numerous receptors that bind to activation fragments. Drug design is facilitated by the increasingly detailed structural understanding of the molecules involved in the complement system. Only two anti-complement drugs are currently on the market, but many more are being developed for diseases that include infectious, inflammatory, degenerative, traumatic and neoplastic disorders. In this Review, we describe the history, current landscape and future directions for anti-complement therapies.

  14. Evaluation of the repeated-dose liver micronucleus assay using 2,4-dinitrotoluene: a report of a collaborative study by CSGMT/JEMS.MMS.

    Science.gov (United States)

    Maeda, Akihisa; Tsuchiyama, Hiromi; Asaoka, Yoshiji; Hirakata, Mikito; Miyoshi, Tomoya; Oshida, Keiyu; Miyamoto, Yohei

    2015-03-01

    The liver micronucleus assay using young adult rats has the potential to detect liver carcinogens by repeated dosing, and could be expected to be integrated into repeated-dose toxicity studies using a hepatocyte isolation method without the traditional in situ collagenase perfusion. In this study, to assess the performance of the repeated-dose liver micronucleus assay, 2,4-dinitrotoluene (DNT), which is a rodent liver carcinogen, was administered orally to male rats at doses of 50, 100 and 200 mg/kg/day once daily for 14 or 28 consecutive days, and the frequencies of micronucleated hepatocytes (MNHEPs) and micronucleated immature erythrocytes (MNIMEs) were examined. Significant increases in the MNHEPs were observed at 50 mg/kg/day or more in the 14-day treatment, and 50 and 100 mg/kg/day in the 28-day treatment. These increases were dependent on both the dose and the number of administrations, which indicates the possibility that the MNHEPs accumulate as a result of repeated dosing. In contrast, no increase in the MNIMEs was observed. In conclusion, the repeated-dose liver micronucleus assay using young adult rats is sufficiently sensitive to detect the genotoxicity of 2,4-DNT at a low dose.

  15. The effect of gamma radiation on the Common carp (Cyprinus carpio): In vivo genotoxicity assessment with the micronucleus and comet assays.

    Science.gov (United States)

    M K, Praveen Kumar; Soorambail K, Shyama; Bhagatsingh Harisingh, Sonaye; D'costa, Avelyno; Ramesh Chandra, Chaubey

    2015-10-01

    Radioactive wastes may be leached into freshwater, either accidentally or in industrial effluents. We have studied gamma radiation-induced DNA damage in the freshwater fish Cyprinus carpio. Fish were irradiated with 2-10Gy gamma radiation and genotoxic effects in blood cells were studied with the micronucleus (MN) and comet assays. Micronuclei and a dose-dependent increase in comet-tail DNA were seen in dose- and time-dependent studies. The highest % tail DNA was observed at 24h, declining until 72h, which may indicate the repair of radiation-induced DNA single-strand breaks after gamma radiation. However, double-stranded DNA damage may not have been repaired, as indicated by increased micronuclei at later periods. A positive correlation was observed between the comet and micronucleus assay results. This study confirms the mutagenic/genotoxic potential of gamma radiation in the Common carp, as well as the possible combined use of the micronucleus and comet assays for in vivo laboratory studies with fresh-water fish for screening the genotoxic potential of radioactive pollution. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. The complement system: a gateway to gene-environment interactions in schizophrenia pathogenesis.

    Science.gov (United States)

    Nimgaonkar, V L; Prasad, K M; Chowdari, K V; Severance, E G; Yolken, R H

    2017-11-01

    The pathogenesis of schizophrenia is considered to be multi-factorial, with likely gene-environment interactions (GEI). Genetic and environmental risk factors are being identified with increasing frequency, yet their very number vastly increases the scope of possible GEI, making it difficult to identify them with certainty. Accumulating evidence suggests a dysregulated complement pathway among the pathogenic processes of schizophrenia. The complement pathway mediates innate and acquired immunity, and its activation drives the removal of damaged cells, autoantigens and environmentally derived antigens. Abnormalities in complement functions occur in many infectious and autoimmune disorders that have been linked to schizophrenia. Many older reports indicate altered serum complement activity in schizophrenia, though the data are inconclusive. Compellingly, recent genome-wide association studies suggest repeat polymorphisms incorporating the complement 4A (C4A) and 4B (C4B) genes as risk factors for schizophrenia. The C4A/C4B genetic associations have re-ignited interest not only in inflammation-related models for schizophrenia pathogenesis, but also in neurodevelopmental theories, because rodent models indicate a role for complement proteins in synaptic pruning and neurodevelopment. Thus, the complement system could be used as one of the 'staging posts' for a variety of focused studies of schizophrenia pathogenesis. They include GEI studies of the C4A/C4B repeat polymorphisms in relation to inflammation-related or infectious processes, animal model studies and tests of hypotheses linked to autoimmune diseases that can co-segregate with schizophrenia. If they can be replicated, such studies would vastly improve our understanding of pathogenic processes in schizophrenia through GEI analyses and open new avenues for therapy.

  17. Kupffer cell complement receptor clearance function and host defense.

    Science.gov (United States)

    Loegering, D J

    1986-01-01

    Kupffer cells are well known to be important for normal host defense function. The development of methods to evaluate the in vivo function of specific receptors on Kupffer cells has made it possible to assess the role of these receptors in host defense. The rationale for studying complement receptors is based on the proposed important role of these receptors in host defense and on the observation that the hereditary deficiency of a complement receptor is associated with recurrent severe bacterial infections. The studies reviewed here demonstrate that forms of injury that are associated with depressed host defense including thermal injury, hemorrhagic shock, trauma, and surgery also cause a decrease in complement receptor clearance function. This decrease in Kupffer cell receptor clearance function was shown not to be the result of depressed hepatic blood flow or depletion of complement components. Complement receptor function was also depressed following the phagocytosis of particulates that are known to depress Kupffer cell host defense function. Endotoxemia and bacteremia also were associated with a depression of complement receptor function. Complement receptor function was experimentally depressed in uninjured animals by the phagocytosis of IgG-coated erythrocytes. There was a close association between the depression of complement receptor clearance function and increased susceptibility to the lethal effects of endotoxin and bacterial infection. These studies support the hypotheses that complement receptors on Kupffer cells are important for normal host defense and that depression of the function of these receptors impairs host defense.

  18. The role of complement in the acquired immune response

    DEFF Research Database (Denmark)

    Nielsen, C H; Fischer, E M; Leslie, R G

    2000-01-01

    Studies over the past three decades have clearly established a central role for complement in the promotion of a humoral immune response. The primary function of complement, in this regard, is to opsonize antigen or immune complexes for uptake by complement receptor type 2 (CR2, CD21) expressed...... on B cells, follicular dendritic cells (FDC) and some T cells. A variety of mechanisms appear to be involved in complement-mediated promotion of the humoral response. These include: enhancement of antigen (Ag) uptake and processing by both Ag-specific and non-specific B cells for presentation...

  19. Ultrastructural changes of the UV-irradiated micronucleus in vegetative cells of paramecium bursaria and its functional importance

    International Nuclear Information System (INIS)

    Borkhsenius, O.N.; Fokin, S.I.

    1982-01-01

    Ultrastructural micronucleus (MI) changes of vegetative cells in Paramecium bursaria in 0.5-7 h after MI ultraviolet irradiation and cell posterity with irradiated MI after different periods (2.6 and 30 days, three years) after ultraviolet irradiation have been studied. It is established that MI irradiation at a dose of 306J/m 2 doesn't result in its loss in postradiation generations however in posterity MI considerable ultrastructural changes occur. In two days after operation the shell of descendant MI of irradiated Paramecium bursaria forms multiple blades; small chromatin blocks considerably increase in sizes and, as a rule, occupy the central position in a nucleus. During later periods afeter irradiation (6 days) density of chromatin elements in MI begins to change. By the 30-st day in MI fine-fibrillar karyoplasm detected are only not numerous chromatin structures scattered in disorder. The results obtained point to the existence of the ''cryptic'' type MIs are not revealed at the light-optical level but preserved in a series of postradiation generations. The presence of such MIs in viable cultures of P. bursaria confirms indirectly MI significance in vegetatic life of P. bursaria

  20. Ultrastructural changes of the UV-irradiated micronucleus in vegetative cells of Paramecium bursaria and its functional importance

    Energy Technology Data Exchange (ETDEWEB)

    Borkhsenius, O.N.; Fokin, S.I. (Leningradskij Gosudarstvennyj Univ. (USSR). Biologicheskij Nauchno-Issledovatel' skij Inst.)

    1982-01-01

    Ultrastructural micronucleus (MI) changes of vegetative cells in Paramecium bursaria in 0.5-7 h after MI ultraviolet irradiation and cell posterity with irradiated MI after different periods (2.6 and 30 days, three years) after ultraviolet irradiation have been studied. It is established that MI irradiation at a dose of 306J/m/sup 2/ doesn't result in its loss in postradiation generations however in posterity MI considerable ultrastructural changes occur. In two days after operation the shell of descendant MI of irradiated Paramecium bursaria forms multiple blades; small chromatin blocks considerably increase in sizes and, as a rule, occupy the central position in a nucleus. During later periods after irradiation (6 days) density of chromatin elements in MI begins to change. By the 30th day in MI fine-fibrillar karyoplasm detected are only not numerous chromatin structures scattered in disorder. The results obtained point to the existence of the ''cryptic'' type MIs are not revealed at the light-optical level but preserved in a series of postradiation generations. The presence of such MIs in viable cultures of P. bursaria confirms indirectly MI significance in vegetatic life of P. bursaria.

  1. Micronucleus frequency and hematologic index in Colossoma macropomum (Pisces, Ariidae) for environmental impact assessment at a protected area in Brazil

    International Nuclear Information System (INIS)

    Sousa, Debora Batista Pinheiro; Neta, Raimunda Nonata Fortes Carvalho

    2014-01-01

    This study used micronucleus assays and erythrocyte indices in the freshwater fish tambaqui, Colossoma macropomum, to assess environmental impacts in the Environmental Protection Area at Maracanã, São Luis, Brazil. Fish were sampled from two locations within the protected area, Serena Lagoon and Ambude River, on four occasions. Biometric data (length and weight) and an aliquot of blood were collected from each fish for analysis. Erythrocyte indices including: mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration were calculated, and blood samples were examined for micronuclei and nuclear morphological changes. Micronuclei were found in fish from both locations, although the frequency was higher in fish from Ambude River. Nuclear morphological changes were identified only in fish collected from Ambude River. Several nuclear morphological changes were found in erythrocytes stained with Giemsa, including: micronuclei and binucleate nuclei. On average, erythrocyte indices were lower in fish collected from Ambude River than in those from Serena Lagoon. Our results indicate that micronuclei and erythrocyte indices can be used in C. macropomum as indicators of environmental health

  2. Micronucleus frequency and hematologic index in Colossoma macropomum (Pisces, Ariidae) for environmental impact assessment at a protected area in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, Debora Batista Pinheiro, E-mail: deborabpsousa@gmail.com [Postgraduate Program of Aquatic Resources and Fishery (PPGRAP/UEMA), State University of Maranhão (Brazil); Neta, Raimunda Nonata Fortes Carvalho [Department of Chemistry and Biology, State University of Maranhão (Brazil)

    2014-10-06

    This study used micronucleus assays and erythrocyte indices in the freshwater fish tambaqui, Colossoma macropomum, to assess environmental impacts in the Environmental Protection Area at Maracanã, São Luis, Brazil. Fish were sampled from two locations within the protected area, Serena Lagoon and Ambude River, on four occasions. Biometric data (length and weight) and an aliquot of blood were collected from each fish for analysis. Erythrocyte indices including: mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration were calculated, and blood samples were examined for micronuclei and nuclear morphological changes. Micronuclei were found in fish from both locations, although the frequency was higher in fish from Ambude River. Nuclear morphological changes were identified only in fish collected from Ambude River. Several nuclear morphological changes were found in erythrocytes stained with Giemsa, including: micronuclei and binucleate nuclei. On average, erythrocyte indices were lower in fish collected from Ambude River than in those from Serena Lagoon. Our results indicate that micronuclei and erythrocyte indices can be used in C. macropomum as indicators of environmental health.

  3. Techniques for induction of premature chromosome condensation (PCC) by Calyculin-A and micronucleus assay for biodosimetry in Vietnam

    International Nuclear Information System (INIS)

    Pham Ngoc Duy; Tran Que; Hoang Hung Tien; Bui Thi Kim Luyen; Nguyen Thi Kim Anh; Ha Thi Ngoc Lien

    2014-01-01

    The International Atomic Energy Agency (IAEA) and World Health Organization are interested in biological dosimetry method for radiation emergency medicine currently. Some cytogenetic techniques such as premature chromosome condensation (PCC) induced by Calyculin-A and micronucleus (MN) assay are necessary to develop biodosimetry in Vietnam. In this study, we optimized the condition for MN assay with 6 µg/ml Cytochalasin-B concentration and 72.5 hours for peripheral lymphocyte blood culture. The optimization for PCC method is 50 nM Calyculin-A concentration for 45 minutes peripheral lymphocyte blood treatment. For samples exposed to 3.0 Gy gamma 60 Co (dose rate 0.0916 Gy/s), the frequency of MN is 19.02 ± 0.38%, NBP is 1.95 ± 0.28%, dicentric and ring is 41.43 ± 8.12% and frag and min is 63.33 ± 5.16%. For samples exposed to 6.0 Gy gamma 60 Co (dose rate 0.0916 Gy/s), the frequency of ring-PCC is 17.73 ± 2.46%, extra unite is 218.91± 7.58%, dicentric is 83.81 ± 1.09%, ring is 10.75 ± 1.74%, fragment and minute is 193.17 ± 13.10%. MN and ring-PCC are specific marker applying for biodosimetry. (author)

  4. Cytogenetic radiosensitivity of G0-lymphocytes of breast and esophageal cancer patients as determined by micronucleus assay

    International Nuclear Information System (INIS)

    Mozdarani, H.; Mansouri, Z.; Haeri, S.A.

    2005-01-01

    Enhanced chromosomal radiosensitivity is a feature of many cancer predisposition conditions, indicative of the important role of chromosomal alterations in carcinogenesis. In this study the cytokinesis-blocked micronucleous assay was used to compare the radiosensitivity of blood lymphocytes obtained from Iranian breast or esophageal cancer patients (n=50, n=16; respectively) with that of control individuals (n=40). For each sample, one thousand binucleate lymphocytes were analyzed before and after in vitro exposure to 3 Gy of γ rays. The radiation-induced frequency of micronucleus was significantly higher in the breast cancer group (261/1,000 binucleated cells) than in esophageal cancer group (241/1,000 binucleated cells, P<0.01) or in the control group (240/1,000 binucleated cells, P<0.01). The results indicate that breast cancer patients are more radiosensitive compared to normal healthy individuals or esophageal cancer patients. Increased radiosensitivity could be due to defects in DNA repair genes involved in breast cancer formation. Since patients with esophageal cancer did not show elevated radiosensitivity, it is assumed that the contribution of radiosensitivity-related genes to the development of esophageal cancer may be smaller than the contribution of those genes to breast cancer. (author)

  5. In vitro biosynthesis of complement protein D

    International Nuclear Information System (INIS)

    Barnum, S.R.

    1985-01-01

    The aim of this study was twofold: to determine site(s) of complement protein D biosynthesis and to examine D biosynthesis with respect to the kinetics of D secretion, the post-translational modification of D and the tissue-specific differences in D secretion and processing. Antigenic D was detected in the culture supernatants of two cell lines, U937 and HepG2, and adherent blood monocytes by a solid-phase radioimmunoassay. D secreted by U937 cells was hemolytically active with a specific activity comparable to D in serum. De novo synthesis of D by U937 cells was demonstrated with the use of cycloheximide. Biosynthetic labeling using 35 S labeled methionine or cysteine, followed by immunoprecipitation demonstrated a single d band intra- and extra-cellularly in all three cell types as analyzed by SDS-PAGE and auto-radiography. Elevated serum D levels in individuals with IgA nephropathy led to studies on the D levels in serum and urine of individuals with chronic renal failure and an individual with Fanconi's syndrome. The former group had elevated serum D levels, compared to normals, and insignificant levels of D in their urine while the patient with Fanconi's syndrome had normal serum D levels but markedly elevated urinary D levels. These studies demonstrate that the monocyte and hepatocyte are both sites of D synthesis and that there are no apparent differences in the secretion rates and processing of D produced by these cell types. The results also suggest that D is not synthesized or secreted as a precursor molecule. Additionally, these studies suggest that the kidney is a major site of D catabolism

  6. Site-targeted complement inhibition by a complement receptor 2-conjugated inhibitor (mTT30) ameliorates post-injury neuropathology in mouse brains.

    Science.gov (United States)

    Rich, Megan C; Keene, Chesleigh N; Neher, Miriam D; Johnson, Krista; Yu, Zhao-Xue; Ganivet, Antoine; Holers, V Michael; Stahel, Philip F

    2016-03-23

    Intracerebral complement activation after severe traumatic brain injury (TBI) leads to a cascade of neuroinflammatory pathological sequelae that propagate host-mediated secondary brain injury and adverse outcomes. There are currently no specific pharmacological agents on the market to prevent or mitigate the development of secondary cerebral insults after TBI. A novel chimeric CR2-fH compound (mTT30) provides targeted inhibition of the alternative complement pathway at the site of tissue injury. This experimental study was designed to test the neuroprotective effects of mTT30 in a mouse model of closed head injury. The administration of 500 μg mTT30 i.v. at 1 h, 4 h and 24 h after head injury attenuated complement C3 deposition in injured brains, reduced the extent of neuronal cell death, and decreased post-injury microglial activation, compared to vehicle-injected placebo controls. These data imply that site-targeted alternative pathway complement inhibition may represent a new promising therapeutic avenue for the future management of severe TBI. Copyright © 2016. Published by Elsevier Ireland Ltd.

  7. Complement Syntax, Mental Verbs, and Theory of Mind in Children Who Are Deaf

    Science.gov (United States)

    Keddington, Holly B.

    2013-01-01

    The present study was conducted in three parts. Each part analyzed theory of mind (ToM) development in children who are deaf in relation to mental verb and complement syntax understanding. In the first part, participants were given a series of tests for the purpose of correlational analysis of ToM, mental verb understanding, and memory for…

  8. Ahn and Son Afr J Tradit Complement Altern Med. (2014) 11(1):28 ...

    African Journals Online (AJOL)

    cadewumi

    Ahn and Son Afr J Tradit Complement Altern Med. (2014) 11(1):28-29 ... The comparisons of the frequency and choice of functional supplements were analysed using Chi-square test with. SPSS (SPSSs 18.0K for ... Significant difference of choice for functional supplements was observed between male and female (p < 0.01) ...

  9. Study of the optimal reaction conditions for assay of the mouse alternative complement pathway

    NARCIS (Netherlands)

    Dijk, H. van; Rademaker, P.M.; Klerx, J.P.A.M.; Willers, J.M.M.

    1985-01-01

    The optimal reaction conditions for hemolytic assay of alternative complement pathway activity in mouse serum were investigated. A microtiter system was used, in which a number of 7.5×106 rabbit erythrocytes per test well appeared to be optimal. Rabbit erythrocytes were superior as target cells over

  10. Complement-coagulation cross-talk: a potential mediator of the physiological activation of complement by low pH

    Directory of Open Access Journals (Sweden)

    Hany Ibrahim Kenawy

    2015-05-01

    Full Text Available The complement system is a major constituent of the innate immune system. It not only bridges innate and adaptive arms of the immune system but also links the immune system with the coagulation system. Current understanding of the role of complement has extended far beyond fighting of infections, and now encompasses maintenance of homeostasis, tissue regeneration and pathophysiology of multiple diseases. It has been known for many years that complement activation is strongly pH sensitive, but only relatively recently has the physiological significance of this been appreciated. Most complement assays are carried out at the physiological pH 7.4. However, pH in some extracellular compartments, for example renal tubular fluid in parts of the tubule, and extracellular fluid at inflammation loci, is sufficiently acidic to activate complement. The exact molecular mechanism of this activation is still unclear, but possible cross talk between the contact system and complement may exist at low pH with subsequent complement activation. The current article reviews the published data on the effect of pH on the contact system and complement activity, the nature of the pH sensor molecules, and the clinical implications of these effects. Of particular interest is chronic kidney disease (CKD accompanied by metabolic acidosis, in which therapeutic alkalinisation of urine has been shown significantly to reduce tubular complement activation products, an effect which may have important implications for slowing progression of CKD.

  11. Complement activation in leprosy: a retrospective study shows elevated circulating terminal complement complex in reactional leprosy.

    Science.gov (United States)

    Bahia El Idrissi, N; Hakobyan, S; Ramaglia, V; Geluk, A; Morgan, B Paul; Das, P Kumar; Baas, F

    2016-06-01

    Mycobacterium leprae infection gives rise to the immunologically and histopathologically classified spectrum of leprosy. At present, several tools for the stratification of patients are based on acquired immunity markers. However, the role of innate immunity, particularly the complement system, is largely unexplored. The present retrospective study was undertaken to explore whether the systemic levels of complement activation components and regulators can stratify leprosy patients, particularly in reference to the reactional state of the disease. Serum samples from two cohorts were analysed. The cohort from Bangladesh included multi-bacillary (MB) patients with (n = 12) or without (n = 46) reaction (R) at intake and endemic controls (n = 20). The cohort from Ethiopia included pauci-bacillary (PB) (n = 7) and MB (n = 23) patients without reaction and MB (n = 15) patients with reaction. The results showed that the activation products terminal complement complex (TCC) (P ≤ 0·01), C4d (P ≤ 0·05) and iC3b (P ≤ 0·05) were specifically elevated in Bangladeshi patients with reaction at intake compared to endemic controls. In addition, levels of the regulator clusterin (P ≤ 0·001 without R; P < 0·05 with R) were also elevated in MB patients, irrespective of a reaction. Similar analysis of the Ethiopian cohort confirmed that, irrespective of a reaction, serum TCC levels were increased significantly in patients with reactions compared to patients without reactions (P ≤ 0·05). Our findings suggests that serum TCC levels may prove to be a valuable tool in diagnosing patients at risk of developing reactions. © 2016 British Society for Immunology.

  12. A vital role for complement in heart disease

    DEFF Research Database (Denmark)

    Lappegård, Knut T; Garred, Peter; Jonasson, Lena

    2014-01-01

    fibrillation often share risk factors both with coronary heart disease and heart failure, and there is some evidence implicating complement activation in atrial fibrillation. Moreover, Chagas heart disease, a protozoal infection, is an important cause of heart failure in Latin America, and the complement...

  13. Schur complements of matrices with acyclic bipartite graphs

    DEFF Research Database (Denmark)

    Britz, Thomas Johann; Olesky, D.D.; van den Driessche, P.

    2005-01-01

    Bipartite graphs are used to describe the generalized Schur complements of real matrices having nos quare submatrix with two or more nonzero diagonals. For any matrix A with this property, including any nearly reducible matrix, the sign pattern of each generalized Schur complement is shown to be ...

  14. Demand Heterogeneity and the Adoption of Platform Complements

    NARCIS (Netherlands)

    G.J. Rietveld (Joost); J.P. Eggers

    2016-01-01

    textabstractThis paper offers a demand-based theory of how platform maturity affects the adoption of platform complements. We argue that differences between early and late adopters of the platform include willingness to pay for the platform-and-complement bundle, risk preferences, preference for

  15. Complement evasion by Bordetella pertussis: implications for improving current vaccines.

    Science.gov (United States)

    Jongerius, Ilse; Schuijt, Tim J; Mooi, Frits R; Pinelli, Elena

    2015-04-01

    Bordetella pertussis causes whooping cough or pertussis, a highly contagious disease of the respiratory tract. Despite high vaccination coverage, reported cases of pertussis are rising worldwide and it has become clear that the current vaccines must be improved. In addition to the well-known protective role of antibodies and T cells during B. pertussis infection, innate immune responses such as the complement system play an essential role in B. pertussis killing. In order to evade this complement activation and colonize the human host, B. pertussis expresses several molecules that inhibit complement activation. Interestingly, one of the known complement evasion proteins, autotransporter Vag8, is highly expressed in the recently emerged B. pertussis isolates. Here, we describe the current knowledge on how B. pertussis evades complement-mediated killing. In addition, we compare this to complement evasion strategies used by other bacterial species. Finally, we discuss the consequences of complement evasion by B. pertussis on adaptive immunity and how identification of the bacterial molecules and the mechanisms involved in complement evasion might help improve pertussis vaccines.

  16. Complement Attack against Aspergillus and Corresponding Evasion Mechanisms

    Directory of Open Access Journals (Sweden)

    Cornelia Speth

    2012-01-01

    Full Text Available Invasive aspergillosis shows a high mortality rate particularly in immunocompromised patients. Perpetually increasing numbers of affected patients highlight the importance of a clearer understanding of interactions between innate immunity and fungi. Innate immunity is considered to be the most significant host defence against invasive fungal infections. Complement represents a crucial part of this first line defence and comprises direct effects against invading pathogens as well as bridging functions to other parts of the immune network. However, despite the potency of complement to attack foreign pathogens, the prevalence of invasive fungal infections is increasing. Two possible reasons may explain that phenomenon: First, complement activation might be insufficient for an effective antifungal defence in risk patients (due to, e.g., low complement levels, poor recognition of fungal surface, or missing interplay with other immune elements in immunocompromised patients. On the other hand, fungi may have developed evasion strategies to avoid recognition and/or eradication by complement. In this review, we summarize the most important interactions between Aspergillus and the complement system. We describe the various ways of complement activation by Aspergillus and the antifungal effects of the system, and also show proven and probable mechanisms of Aspergillus for complement evasion.

  17. Assessing reprogramming by chimera formation and tetraploid complementation.

    Science.gov (United States)

    Li, Xin; Xia, Bao-long; Li, Wei; Zhou, Qi

    2015-01-01

    Pluripotent stem cells can be evaluated by pluripotent markers expression, embryoid body aggregation, teratoma formation, chimera contribution and even more, tetraploid complementation. Whether iPS cells in general are functionally equivalent to normal ESCs is difficult to establish. Here, we present the detailed procedure for chimera formation and tetraploid complementation, the most stringent criterion, to assessing pluripotency.

  18. Inactivation of complement by Loxosceles reclusa spider venom.

    Science.gov (United States)

    Gebel, H M; Finke, J H; Elgert, K D; Cambell, B J; Barrett, J T

    1979-07-01

    Zymosan depletion of serum complement in guinea pigs rendered them highly resistant to lesion by Loxosceles reclusa spider venom. Guinea pigs deficient in C4 of the complement system are as sensitive to the venom as normal guinea pigs. The injection of 35 micrograms of whole recluse venom intradermally into guinea pigs lowered their complement level by 35.7%. Brown recluse spider venom in concentrations as slight as 0.02 micrograms protein/ml can totally inactivate one CH50 of guinea pig complement in vitro. Bee, scorpion, and other spider venoms had no influence on the hemolytic titer of complement. Fractionation of recluse spider venom by Sephadex G-200 filtration separated the complement-inactivating property of the venom into three major regions which could be distinguished on the basis of heat stability as well as size. None was neutralized by antivenom. Polyacrylamide gel electrophoresis of venom resolved the complement inactivators into five fractions. Complement inactivated by whole venom or the Sephadex fractions could be restored to hemolytic activity by supplements of fresh serum but not by heat-inactivated serum, pure C3, pure C5, or C3 and C5 in combination.

  19. Von Neumann algebras as complemented subspaces of B(H)

    DEFF Research Database (Denmark)

    Christensen, Erik; Wang, Liguang

    2014-01-01

    Let M be a von Neumann algebra of type II1 which is also a complemented subspace of B( H). We establish an algebraic criterion, which ensures that M is an injective von Neumann algebra. As a corollary we show that if M is a complemented factor of type II1 on a Hilbert space H, then M is injective...

  20. Novel Evasion Mechanisms of the Classical Complement Pathway.

    Science.gov (United States)

    Garcia, Brandon L; Zwarthoff, Seline A; Rooijakkers, Suzan H M; Geisbrecht, Brian V

    2016-09-15

    Complement is a network of soluble and cell surface-associated proteins that gives rise to a self-amplifying, yet tightly regulated system with fundamental roles in immune surveillance and clearance. Complement becomes activated on the surface of nonself cells by one of three initiating mechanisms known as the classical, lectin, and alternative pathways. Evasion of complement function is a hallmark of invasive pathogens and hematophagous organisms. Although many complement-inhibition strategies hinge on hijacking activities of endogenous complement regulatory proteins, an increasing number of uniquely evolved evasion molecules have been discovered over the past decade. In this review, we focus on several recent investigations that revealed mechanistically distinct inhibitors of the classical pathway. Because the classical pathway is an important and specific mediator of various autoimmune and inflammatory disorders, in-depth knowledge of novel evasion mechanisms could direct future development of therapeutic anti-inflammatory molecules. Copyright © 2016 by The American Association of Immunologists, Inc.

  1. [Renal risks of dietary complements: a forgotten cause].

    Science.gov (United States)

    Dori, Olympia; Humbert, Antoine; Burnier, Michel; Teta, Daniel

    2014-02-26

    The use of dietary complements like vitamins, minerals, trace elements, proteins, aminoacids and plant-derived agents is prevalent in the general population, in order to promote health and treat diseases. Dietary complements are considered as safe natural products and are easily available without prescription. However, these can lead to severe renal toxicity, especially in cases of unknown pre-existing chronic kidney disease (CKD). In particular, Chinese herbs including aristolochic acid, high doses of vitamine C, creatine and protein complements may lead to acute and chronic renal failure, sometimes irreversible. Dietary complement toxicity should be suspected in any case of unexplained renal impairement. In the case of pre-existing CKD, the use of potentially nephrotoxic dietary complements should be screened for.

  2. Mechanisms of complement activation by dextran-coated superparamagnetic iron oxide (SPIO) nanoworms in mouse versus human serum

    DEFF Research Database (Denmark)

    Banda, Nirmal K; Mehta, Gaurav; Chao, Ying

    2014-01-01

    BACKGROUND: The complement system is a key component of innate immunity implicated in the neutralization and clearance of invading pathogens. Dextran coated superparamagnetic iron oxide (SPIO) nanoparticle is a promising magnetic resonance imaging (MRI) contrast agent. However, dextran SPIO has...... the mechanisms of human complement activation. Mouse data were analyzed by non-paired t-test, human data were analyzed by ANOVA followed by multiple comparisons with Student-Newman-Keuls test. RESULTS: In mouse sera, SPIO NW triggered the complement activation via the LP, whereas the AP contributes via...... the CP, but that did not affect the total level of C3 deposition on the particles. CONCLUSIONS: There were important differences and similarities in the complement activation by SPIO NW in mouse versus human sera. Understanding the mechanisms of immune recognition of nanoparticles in mouse and human...

  3. Peroxisome biogenesis disorders: identification of a new complementation group distinct from peroxisome-deficient CHO mutants and not complemented by human PEX 13

    NARCIS (Netherlands)

    Shimozawa, N.; Suzuki, Y.; Zhang, Z.; Imamura, A.; Tsukamoto, T.; Osumi, T.; Tateishi, K.; Okumoto, K.; Fujiki, Y.; Orii, T.; Barth, P. G.; Wanders, R. J.; Kondo, N.

    1998-01-01

    Ten complementation groups of generalized peroxisome biogenesis disorders (PBD), (excluding rhizomelic chondrodysplasia punctata) have been identified using complementation analysis. Four of the genes involved have been identified using two different methods of (1) genetic functional complementation

  4. Age and smoking habit influence on the spontaneous and radiation induced frequencies of the micronucleus in human lymphocytes

    International Nuclear Information System (INIS)

    Di Giorgio, M.; Nasazzi, N.; Heredia, M.L.

    1996-01-01

    Several endpoints have been used for monitoring human population that have been exposed at work or in the environment to genotoxic agents, particularly to ionizing radiation. The cytokinesis-block micronucleus (MN) assay in peripheral lymphocytes is a reliable method for evaluating radiation induced chromosomal damage (DNA breaks and mitotic spindle disturbances) and thus, a suitable dosimeter for estimating in vivo whole body exposures. A research to determine the influence of age, sex and life style factors (smoking habits) on the MN spontaneous and radiation induced frequencies was carried out in order to define the use of this assay in Biological Dosimetry. The estimation of MN frequencies was analyzed in lymphocytes cultures from 50 health donors aged between 4 and 60 years. Based on the smoking habits, they were divided into 2 groups. A fraction of the sample was irradiated in vitro with γ-rays in the range of 0.35 Gy to 4 Gy. A statistically significant influence on the spontaneous MN frequency was observed (R 2 = 0.59) when the variables age and smoking habit were analyzed, and a statistically significant influence on the radiation induced MN frequency was also obtained (R 2 = 0.86) when dose, age and smoking habit were studied. Sex did not influence significantly MN variability, but there was a greater dispersion in the results obtained from female donors, when compared to males, possibly due to the loss of X chromosomes. The comparison of the data from smoking donors to the data from non smoking donors supports the convenience of taking into account the smoking habit for estimating in vivo whole body exposure to γ-rays for doses below 2 Gy. (authors). 8 refs., 3 figs., 2 tabs

  5. Evaluation of spontaneous and radiation-induced micronucleus frequency in cultured human peripheral blood lymphocytes depending on age and sex

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, H. J.; Kang, C. M.; Chung, H. C. [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)] (and others)

    2002-12-15

    The goal of this study was to provide data on the dose-dependent production of MicroNucleus (MN) in human lymphocytes irradiated with {sup 60}Co {gamma}-rays and 50MeV neutron, and to evaluate predictive markers of intrinsic radiosensitivity in individuals for monitoring occupational or environmental radiation exposure. For the dose-response study, heparinized whole blood of 10 healthy volunteers was irradiated with {sup 60}Co {gamma}-rays employing of 0.25-8Gy. The MNs were observed all doses, and the numerical changes according to doses. In dose-response curves fit linear-quadratic form (alpha =0.31{+-}0.049, beta =0.0022{+-}0.0022) for {gamma}-rays, but (alpha=0.99{+-}0.528, beta =0.0093{+-}0.0047) for neutron. Neutrons were than {gamma}-rays effective in producing MN with dose-dependent manner. The frequency of MN varies with dose. The RBE (Relative Biological Effectiveness) for micronuclei was 2.370.17. Further studies were carried out to provide evidence for the existence of individual variations in age-dependent responses to radiation. Spontaneous and radiation-induced MN varies greatly among individuals, and little is known about the molecular mechanisms of this variability. It was shown that the increased level of spontaneous cell with MN was observed with increasing age. The relationship between radiosensitivity and the increased spontaneous level of MN may be in inverse proportion. These studies indicated that the MN assay have a high potential as a rapid, sensitive and accurate method which can be used to monitor a large population exposed to radiation for rapid triage in the case of a large-scale accident.

  6. Evaluation of spontaneous and radiation-induced micronucleus frequency in cultrued human peripheral blood lymphocytes depending on age and sex

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, H. J.; Kang, C. M.; Chung, H. C. [Korea Cancer Center Hospital, Seoul (Korea, Republic of)] [and others

    2002-07-01

    The goal of this study was to provide data on the dose-dependent production of micronucleus (MN) in human lymphocytes irradiated with {sub 60} Co {gamma} -rays and 50MeV neutron, and to evaluate predictive markers of intrinsic radiosensitivity in individuals for monitoring occupational or environmental radiation exposure. For the dose-response study, heparinized whole blood of 10 healthy volunteers was irradiated with {sub 60} Co {gamma} -rays employing of 0.25-8Gy. The MNs were observed all doses, and the numerical changes according to doses. In dose-response curves fit linear- quadratic form (alpha =0.31{+-}0.049, beta =0.0022{+-}0.0022) for {gamma} -rays, but (alpha =0.99{+-}0.528, beta =0.0093{+-}0.0047) for neutron. Neutrons were than {gamma} -rays effective in producing MN with dose-dependent manner. The frequency of MN varies with dose. The RBE for micronuclei was 2.37{+-}0.17. Further studied are carried out to provide evidence for the existence of individual variations in age-dependent responses to radiation. Spontaneous and radiation-induced MN varies greatly between individuals, and little is known about the molecular mechanisms of this variability. It was shown that the increased level of spontaneous cell with MN was observed with increasing age. The relationship between radiosensitivity and the increased spontaneous level of MN may be in inverse proportion. These studies indicates that the MN assay have a high potential as a rapid, sensitive and accurate method which can be used to monitor a large population exposed to radiation for rapid triage in the case of a large-scale accident.

  7. In situ monitoring of urban air in Córdoba, Argentina using the Tradescantia-micronucleus (Trad-MCN) bioassay

    Science.gov (United States)

    Carreras, H. A.; Pignata, M. L.; Saldiva, P. H. N.

    During the last decades, a significant deterioration of ambient air quality has been observed in Argentina. However, the availability of air pollution monitoring stations is still limited to only few cities. In this study, we investigated the genotoxicity of ambient levels of air pollution in Córdoba using the Tradescantia micronucleus assay. The experiment was performed from October, 2004 to April 2005. Pots with Tradescantia pallida were placed in three sites: Córdoba city center, characterized by important avenues with high traffic activity (cars, taxis, and public transport vehicles); the university campus, along a side road with heavy traffic of gasoline and diesel powered vehicles, buses and trucks; and a residential area, with no significant local sources of air pollution. Twenty young T. pallida inflorescences were collected from each sampling site in November, February and April. Micronuclei frequencies were determined in early tetrads of pollen mother cells and expressed as MCN/100 tetrads. Simultaneously, the environmental levels of total suspended particles (24 h mean) were determined for each site. A significant difference in micronuclei frequency was observed among sites ( p=0.036). Post-hoc analysis revealed that the residential area exhibited a lower micronuclei frequency than the university and city center areas. In conclusion, we found that the gradients of ambient air pollution of Córdoba are associated with changes in the spontaneous micronuclei frequency of Tradescantia pollen mother cells. These results indicate that in situ biomonitoring with higher plants may be useful for characterizing air pollution in areas without instrumental monitoring techniques, or for exploring the distribution of air contaminants at a microscale.

  8. Functional analysis of the putative peroxidase domain of FANCA, the Fanconi anemia complementation group A protein.

    Science.gov (United States)

    Ren, J; Youssoufian, H

    2001-01-01

    Fanconi anemia (FA) is an autosomal recessive disorder manifested by chromosomal breakage, birth defects, and susceptibility to bone marrow failure and cancer. At least seven complementation groups have been identified, and the genes defective in four groups have been cloned. The most common subtype is complementation group A. Although the normal functions of the gene products defective in FA cells are not completely understood, a clue to the function of the FA group A gene product (FANCA) was provided by the detection of limited homology in the amino terminal region to a class of heme peroxidases. We evaluated this hypothesis by mutagenesis and functional complementation studies. We substituted alanine residues for the most conserved FANCA residues in the putative peroxidase domain and tested their effects on known biochemical and cellular functions of FANCA. While the substitution mutants were comparable to wild-type FANCA with regard to their stability, subcellular localization, and interaction with FANCG, only the Trp(183)-to-Ala substitution (W183A) abolished the ability of FANCA to complement the sensitivity of FA group A cells to mitomycin C. By contrast, TUNEL assays for apoptosis after exposure to H2O2 showed no differences between parental FA group A cells, cells complemented with wild-type FANCA, and cells complemented with the W183A of FANCA. Moreover, semiquantitative RT-PCR analysis for the expression of the peroxide-sensitive heme oxygenase gene showed appropriate induction after H2O2 exposure. Thus, W183A appears to be essential for the in vivo activity of FANCA in a manner independent of its interaction with FANCG. Moreover, neither wild-type FANCA nor the W183A mutation appears to alter the peroxide-induced apoptosisor peroxide-sensing ability of FA group A cells. Copyright 2001 Academic Press.

  9. More than just immune evasion: Hijacking complement by Plasmodium falciparum.

    Science.gov (United States)

    Schmidt, Christoph Q; Kennedy, Alexander T; Tham, Wai-Hong

    2015-09-01

    Malaria remains one of the world's deadliest diseases. Plasmodium falciparum is responsible for the most severe and lethal form of human malaria. P. falciparum's life cycle involves two obligate hosts: human and mosquito. From initial entry into these hosts, malaria parasites face the onslaught of the first line of host defence, the complement system. In this review, we discuss the complex interaction between complement and malaria infection in terms of hosts immune responses, parasite survival and pathogenesis of severe forms of malaria. We will focus on the role of complement receptor 1 and its associated polymorphisms in malaria immune complex clearance, as a mediator of parasite rosetting and as an entry receptor for P. falciparum invasion. Complement evasion strategies of P. falciparum parasites will also be highlighted. The sexual forms of the malaria parasites recruit the soluble human complement regulator Factor H to evade complement-mediated killing within the mosquito host. A novel evasion strategy is the deployment of parasite organelles to divert complement attack from infective blood stage parasites. Finally we outline the future challenge to understand the implications of these exploitation mechanisms in the interplay between successful infection of the host and pathogenesis observed in severe malaria. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Complement and the control of HIV infection: an evolving story.

    Science.gov (United States)

    Frank, Michael M; Hester, Christopher; Jiang, Haixiang

    2014-05-01

    Thirty years ago, investigators isolated and later determined the structure of HIV-1 and its envelope proteins. Using techniques that were effective with other viruses, they prepared vaccines designed to generate antibody or T-cell responses, but they were ineffective in clinical trials. In this article, we consider the role of complement in host defense against enveloped viruses, the role it might play in the antibody response and why complement has not controlled HIV-1 infection. Complement consists of a large group of cell-bound and plasma proteins that are an integral part of the innate immune system. They provide a first line of defense against microbes and also play a role in the immune response. Here we review the studies of complement-mediated HIV destruction and the role of complement in the HIV antibody response. HIV-1 has evolved a complex defense to prevent complement-mediated killing reviewed here. As part of these studies, we have discovered that HIV-1 envelope, on administration into animals, is rapidly broken down into small peptides that may prove to be very inefficient at provident the type of antigenic stimulation that leads to an effective immune response. Improving complement binding and stabilizing envelope may improve the vaccine response.

  11. Cyclosporine Induces Endothelial Cell Release of Complement-Activating Microparticles

    Science.gov (United States)

    Renner, Brandon; Klawitter, Jelena; Goldberg, Ryan; McCullough, James W.; Ferreira, Viviana P.; Cooper, James E.; Christians, Uwe

    2013-01-01

    Defective control of the alternative pathway of complement is an important risk factor for several renal diseases, including atypical hemolytic uremic syndrome. Infections, drugs, pregnancy, and hemodynamic insults can trigger episodes of atypical hemolytic uremic syndrome in susceptible patients. Although the mechanisms linking these clinical events with disease flares are unknown, recent work has revealed that each of these clinical conditions causes cells to release microparticles. We hypothesized that microparticles released from injured endothelial cells promote intrarenal complement activation. Calcineurin inhibitors cause vascular and renal injury and can trigger hemolytic uremic syndrome. Here, we show that endothelial cells exposed to cyclosporine in vitro and in vivo release microparticles that activate the alternative pathway of complement. Cyclosporine-induced microparticles caused injury to bystander endothelial cells and are associated with complement-mediated injury of the kidneys and vasculature in cyclosporine-treated mice. Cyclosporine-induced microparticles did not bind factor H, an alternative pathway regulatory protein present in plasma, explaining their complement-activating phenotype. Finally, we found that in renal transplant patients, the number of endothelial microparticles in plasma increases 2 weeks after starting tacrolimus, and treatment with tacrolimus associated with increased C3 deposition on endothelial microparticles in the plasma of some patients. These results suggest that injury-associated release of endothelial microparticles is an important mechanism by which systemic insults trigger intravascular complement activation and complement-dependent renal diseases. PMID:24092930

  12. Functional analysis of Ficolin-3 mediated complement activation

    DEFF Research Database (Denmark)

    Hein, Estrid; Honoré, Christian; Skjoedt, Mikkel-Ole

    2010-01-01

    Ficolin-3 mediated complement activation that could be applicable for research and clinical use. Bovine serum albumin (BSA) was acetylated (acBSA) and chosen as a solid phase ligand for Ficolins in microtiter wells. Binding of Ficolins on acBSA was evaluated, as was functional complement activation...... was applied to the samples that inhibited interference from the classical pathway due to the presence of anti-BSA antibodies in some sera. We describe a novel functional method for measuring complement activation mediated by Ficolin-3 in human serum up to the formation of TCC. The assay provides...

  13. The role of the complement system in diabetic nephropathy

    DEFF Research Database (Denmark)

    Flyvbjerg, Allan

    2017-01-01

    -threatening disease. An increasing body of evidence points toward a role of the complement system in the pathogenesis of diabetic nephropathy. For example, circulating levels of mannose-binding lectin (MBL), a pattern recognition molecule of the innate immune system, have emerged as a robust biomarker...... for the development and progression of this disease, and evidence suggests that MBL, H-ficolin, complement component C3 and the membrane attack complex might contribute to renal injury in the hyperglycaemic mileu. New approaches to modulate the complement system might lead to the development of new agents to prevent...

  14. Is mobile phone radiation genotoxic? An analysis of micronucleus frequency in exfoliated buccal cells.

    Science.gov (United States)

    de Oliveira, F M; Carmona, A M; Ladeira, C

    2017-10-01

    Electromagnetic fields (EMF) are classified as "possibly carcinogenic" by the International Agency for Research on Cancer (IARC). Some publications have reported associations between EMF exposure and DNA damage, but many other studies contradict such findings. Cytomorphological changes, such as micronuclei (MN), indicative of genomic damage, are biomarkers of genotoxicity. To test whether mobile phone-associated EMF exposure affects the MN frequency in exfoliated buccal cells, we obtained cells smears from the left and right inner cheeks of healthy mobile phone users, aged 18-30 (n=86), who also completed a characterization survey. MN frequencies were tested for potential confounding factors and for duration of phone use and preferential side of mobile phone use. No relationship was observed between MN frequency and duration of mobile phone use in daily calls. Cells ipsilateral to mobile phone use did not present a statistically significantly higher MN frequency, compared to cells contralateral to exposure. A highly statistically significant (pphone-associated EMF do not to induce MN formation in buccal cells at the observed exposure levels. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Radiation risk assessment in professionals working in dental radiology area using buccal micronucleus cytome assay.

    Science.gov (United States)

    Sadatullah, Syed; Dawasaz, Ali Azhar; Luqman, Master; Assiry, Ali A; Almeshari, Ahmed A; Togoo, Rafi Ahmad

    2013-11-01

    The aim of this study was to assess the incidence of micronuclei (MN) in buccal mucosal cells of professionals working in radiology area to determine the risk of stochastic effects of radiation. All the professionals and students working in King Khalid University - College of Dentistry radiology area were included in the Risk Group (RG = 27). The Control Group (CG = 27) comprised of healthy individual matching the gender and age of the RG. Buccal mucosal scraping from all the 54 subjects of RG and CG were stained with Papanicolaou stain and observed under oil immersion lens (×100) for the presence of micronuclei (MN) in the exfoliated epithelial cells. There was no significant difference between the incidence of MN in RG and CG (p = >0.05) using t-test. Routine radiation protection protocol does minimize the risk of radiation induced cytotoxicity, however, screening of professionals should be carried out at regular intervals.

  16. Plasma complement and vascular complement deposition in patients with coronary artery disease with and without inflammatory rheumatic diseases

    Science.gov (United States)

    2017-01-01

    Purpose Inflammatory rheumatic diseases (IRD) are associated with accelerated coronary artery disease (CAD), which may result from both systemic and vascular wall inflammation. There are indications that complement may be involved in the pathogenesis of CAD in Systemic Lupus Erythematosus (SLE) and Rheumatoid Arthritis (RA). This study aimed to evaluate the associations between circulating complement and complement activation products with mononuclear cell infiltrates (MCI, surrogate marker of vascular inflammation) in the aortic media and adventitia in IRDCAD and non-IRDCAD patients undergoing coronary artery bypass grafting (CABG). Furthermore, we compared complement activation product deposition patterns in rare aorta adventitial and medial biopsies from SLE, RA and non-IRD patients. Methods We examined plasma C3 (p-C3) and terminal complement complexes (p-TCC) in 28 IRDCAD (SLE = 3; RA = 25), 52 non-IRDCAD patients, and 32 IRDNo CAD (RA = 32) from the Feiring Heart Biopsy Study. Aortic biopsies taken from the CAD only patients during CABG were previously evaluated for adventitial MCIs. The rare aortic biopsies from 3 SLE, 3 RA and 3 non-IRDCAD were assessed for the presence of C3 and C3d using immunohistochemistry. Results IRDCAD patients had higher p-TCC than non-IRDCAD or IRDNo CAD patients (prheumatic disease, and, in particular, SLE with the complement system. Exaggerated systemic and vascular complement activation may accelerate CVD, serve as a CVD biomarker, and represent a target for new therapies. PMID:28362874

  17. Language and theory of mind in autism spectrum disorder: the relationship between complement syntax and false belief task performance.

    Science.gov (United States)

    Lind, Sophie E; Bowler, Dermot M

    2009-06-01

    This study aimed to test the hypothesis that children with autism spectrum disorder (ASD) use their knowledge of complement syntax as a means of "hacking out" solutions to false belief tasks, despite lacking a representational theory of mind (ToM). Participants completed a "memory for complements" task, a measure of receptive vocabulary, and traditional location change and unexpected contents false belief tasks. Consistent with predictions, the correlation between complement syntax score and location change task performance was significantly stronger within the ASD group than within the comparison group. However, contrary to predictions, complement syntax score was not significantly correlated with unexpected contents task performance within either group. Possible explanations for this pattern of results are considered.

  18. Complement: a key system for immune surveillance and homeostasis.

    Science.gov (United States)

    Ricklin, Daniel; Hajishengallis, George; Yang, Kun; Lambris, John D

    2010-09-01

    Nearly a century after the significance of the human complement system was recognized, we have come to realize that its functions extend far beyond the elimination of microbes. Complement acts as a rapid and efficient immune surveillance system that has distinct effects on healthy and altered host cells and foreign intruders. By eliminating cellular debris and infectious microbes, orchestrating immune responses and sending 'danger' signals, complement contributes substantially to homeostasis, but it can also take action against healthy cells if not properly controlled. This review describes our updated view of the function, structure and dynamics of the complement network, highlights its interconnection with immunity at large and with other endogenous pathways, and illustrates its multiple roles in homeostasis and disease.

  19. Defining the complement biomarker profile of c3 glomerulopathy

    DEFF Research Database (Denmark)

    Zhang, Yuzhou; Nester, Carla M; Martin, Bertha

    2014-01-01

    BACKGROUND AND OBJECTIVES: C3 glomerulopathy (C3G) applies to a group of renal diseases defined by a specific renal biopsy finding: a dominant pattern of C3 fragment deposition on immunofluorescence. The primary pathogenic mechanism involves abnormal control of the alternative complement pathway......, although a full description of the disease spectrum remains to be determined. This study sought to validate and define the association of complement dysregulation with C3G and to determine whether specific complement pathway abnormalities could inform disease definition. DESIGN, SETTING, PARTICIPANTS......, & MEASUREMENTS: This study included 34 patients with C3G (17 with C3 glomerulonephritis [C3GN] and 17 with dense deposit disease [DDD]) diagnosed between 2008 and 2013 selected from the C3G Registry. Control samples (n=100) were recruited from regional blood drives. Nineteen complement biomarkers were assayed...

  20. Effects of radiographic contrast media on the serum complement system

    International Nuclear Information System (INIS)

    Tirone, P.; Boldrini, E.

    1983-01-01

    The authors explored the activation of the complement system produced by a nonionic organic iodine compound, namely iopamidol, which is proposed as a contrast medium for radiographic examination by intravenous and intra-arterial injection. The study was conducted in vitro versus established ionic contrasts (diatrizoate, iothalamate, acetrizoate) and a nonionic compound (metrizamide). The adopted experimental model was the immunohemolytic detector system, in which the immune complex consisted of goat erythrocytes sensitized with the corresponding antibody (hemolysin), and complement (C') was supplied by guinea pig serum. All the products caused complement activation. The results show that nonionic contrast media produce less activation of the complement system than the traditional ionic contrast. Thus the use of nonionic contrast for radiological procedures necessitating the introduction of contrast material into the blood compartment would imply a reduced risk of anaphylactoid reactions. (orig.)

  1. Complement C4 phenotypes in dementia of the Alzheimer type

    NARCIS (Netherlands)

    Eikelenboom, P.; Goetz, J.; Pronk, J. C.; Hauptmann, G.

    1988-01-01

    Complement C4 phenotype distribution was studied in 64 patients with dementia of the Alzheimer type. In contrast to reported findings we failed to find a significant association between C4B2 gene frequency and Alzheimer's dementia

  2. Complement Involvement in Periodontitis: Molecular Mechanisms and Rational Therapeutic Approaches.

    Science.gov (United States)

    Hajishengallis, George; Maekawa, Tomoki; Abe, Toshiharu; Hajishengallis, Evlambia; Lambris, John D

    2015-01-01

    The complement system is a network of interacting fluid-phase and cell surface-associated molecules that trigger, amplify, and regulate immune and inflammatory signaling pathways. Dysregulation of this finely balanced network can destabilize host-microbe homeostasis and cause inflammatory tissue damage. Evidence from clinical and animal model-based studies suggests that complement is implicated in the pathogenesis of periodontitis, a polymicrobial community-induced chronic inflammatory disease that destroys the tooth-supporting tissues. This review discusses molecular mechanisms of complement involvement in the dysbiotic transformation of the periodontal microbiome and the resulting destructive inflammation, culminating in loss of periodontal bone support. These mechanistic studies have additionally identified potential therapeutic targets. In this regard, interventional studies in preclinical models have provided proof-of-concept for using complement inhibitors for the treatment of human periodontitis.

  3. Evaluation of complement proteins as screening markers for colorectal cancer

    DEFF Research Database (Denmark)

    Storm, Line; Christensen, Ib J; Jensenius, Jens C

    2015-01-01

    BACKGROUND: Colorectal cancer (CRC) is a leading cause of cancer death worldwide. Lack of symptoms results in late detection and increased mortality. Inflammation, including complement activation, plays an important role in tumorigenesis. EXPERIMENTAL DESIGN: The concentrations of nine proteins...

  4. Intracistronic complementation in the simian virus 40 A gene.

    Science.gov (United States)

    Tornow, J; Cole, C N

    1983-01-01

    A set of eight simian virus 40 mutants was constructed with lesions in the A gene, which encodes the large tumor (T) antigen. These mutants have small deletions (3-20 base pairs) at either 0.497, 0.288, or 0.243 map units. Mutants having both in-phase and frameshift mutations at each site were isolated. Neither plaque formation nor replication of the mutant DNAs could be detected after transfection of monkey kidney cells. Another nonviable mutant, dlA2459, had a 14-base-pair deletion at 0.193 map unit and was positive for viral DNA replication. Each of the eight mutants were tested for ability to form plaques after cotransfection with dlA2459 DNA. The four mutants that had in-phase deletions were able to complement dlA2459. The other four, which had frameshift deletions, did not. No plaques were formed after cotransfection of cells with any other pair of group A mutants. This suggests that the defect in dlA2459 defines a distinct functional domain of simian virus 40 T antigen. Images PMID:6312452

  5. Complement receptor expression and activation of the complement cascade on B lymphocytes from patients with systemic lupus erythematosus (SLE)

    DEFF Research Database (Denmark)

    Marquart, H V; Svendsen, A; Rasmussen, J M

    1995-01-01

    It has previously been reported that the expression of the complement receptors, CR1 on erythrocytes and blood leucocytes and CR2 on B cells, is reduced in patients with SLE, and that the reduced expression of CR1 on erythrocytes is related to disease activity. We have earlier demonstrated...... that normal B cells are capable of activating the alternative pathway (AP) of complement in a CR2-dependent fashion. In this study we have investigated whether disturbances in this activity may be related to the altered phenotype of SLE B cells. Flow cytometry was used to measure expression of complement...

  6. Anti-complement activities of human breast-milk.

    Science.gov (United States)

    Ogundele, M O

    1999-08-01

    It has long been observed that the human milk possesses significant anti-inflammatory properties, while simultaneously protecting the infant against many intestinal and respiratory pathogens. There is, however, a paucity of information on the degree and extent of this anti-inflammatory activity. In the present study, the inhibitory effects of different fractions of human milk on serum complement activity were analysed. Colostrum and milk samples from healthy voluntary lactating donors at different postpartum ages were obtained and pooled normal human serum was used as source of complement in a modified CH50 assay. Inherent complement activity in human milk was also investigated by measuring the deposition of an activated C3 fragment on a serum-sensitive bacteria, and by haemolytic assays. Most whole- and defatted-milk samples consistently showed a dose-dependent inhibition of the serum complement activity. This inhibition was greater in mature milk compared to transitional milk samples. It was enhanced by inactivation of milk complement, and diminished by centrifugation of milk samples, which partly removed fat and larger protein components including casein micelles. Inherent complement activity in human milk was also demonstrated by haemolysis of sensitised sheep erythrocytes and deposition of C3 fragments on solid-phase bacteria. These activities were highest in the colostrum and gradually decreased as lactation proceeded. Several natural components abundant in the fluid phase of the human breast-milk have been shown to be inhibitors of complement activation in vitro. Their physiological significance probably reside in their ability to prevent inflammatory-induced tissue damage of the delicate immature gastrointestinal tract of the new-born as well as the mammary gland itself, which may arise from ongoing complement activation.

  7. Hepatic macrophage complement receptor clearance function following injury.

    Science.gov (United States)

    Cuddy, B G; Loegering, D J; Blumenstock, F A; Shah, D M

    1986-03-01

    Previous work has demonstrated that in vivo hepatic macrophage complement receptor clearance function is depressed following thermal injury. The present study was carried out to determine if complement receptor function depression is associated with other states of depressed host defense. Hepatic complement receptor clearance function was determined from the hepatic uptake of rat erythrocytes coated with antierythrocyte IgM (EIgM) in rats. Receptor function was determined following cannulation of a carotid artery, laparotomy plus enterotomy, hemorrhagic shock, trauma, thermal injury, acute bacteremia, acute endotoxemia, and injection of erythrocyte stroma, gelatinized lipid emulsion, or colloidal carbon. Hepatic uptake of EIgM was depressed following each of these experimental interventions except arterial cannulation. This effect was shown not to be due to a decrease in hepatic blood flow or depletion of complement and was therefore due to a depression in hepatic macrophage complement receptor clearance function. Thus, impairment of hepatic macrophage complement receptor function is associated with several states of depressed host defense.

  8. Does host complement kill Borrelia burgdorferi within ticks?

    Science.gov (United States)

    Rathinavelu, Sivaprakash; Broadwater, Anne; de Silva, Aravinda M

    2003-02-01

    The Lyme disease spirochete, Borrelia burgdorferi, inhabits the gut lumen of the tick vector. At this location the spirochete is exposed to host blood when a tick feeds. We report here on studies that were done with normal and complement-deficient (C3-knockout) mice to determine if the host complement system killed spirochetes within the vector. We found that spirochete numbers within feeding nymphs were not influenced by complement, most likely because host complement was inactivated within the vector. The Lyme disease outer surface protein A (OspA) vaccine is a transmission-blocking vaccine that targets spirochetes in the vector. In experiments with mice hyperimmunized with OspA, complement was not required to kill spirochetes within nymphs and to block transmission from nymphs to the vaccinated host. However, host complement did enhance the ability of OspA antibody to block larvae from acquiring spirochetes. Thus, the effects of OspA antibody on nymphal transmission and larval acquisition appear to be based on different mechanisms.

  9. Gonadal sex chromosome complement in individuals with sex chromosomal and/or gonadal disorders

    Energy Technology Data Exchange (ETDEWEB)

    Bridge, J.A.; Sanger, W.G.; Seemayer, T. [Univ. of Nebraska Medical Center, Omaha, NE (United States)] [and others

    1994-09-01

    Gonadal abnormalities are characteristically seen in patients with sex chromosomal aneuploidy. Morphologically these abnormalities can be variable and are hypothesized to be dependent on the sex chromosomal consititution of the gonad (independent of the chromosomal complement of other tissues, such as peripheral blood lymphocytes). In this study, the gonadal sex chromosome complement was evaluated for potential mosaicism and correlated with the histopathology from 5 patients with known sex chromosomal and/or gonadal disorders. FISH techniques using X and Y chromosome specific probes were performed on nuclei extracted from paraffin embedded tissue. Gonadal tissue obtained from case 1 (a true hemaphroditic newborn) consisted of ovotestes and epididymis (left side) and ovary with fallopian tube (right side). Cytogenetic and FISH studies performed on blood, ovotestes and ovary revealed an XX complement. Cytogenetic analysis of blood from case 2, a 4-year-old with suspected Turner syndrome revealed 45,X/46,X,del(Y)(q11.21). FISH analysis of the resected gonads (histologically = immature testes) confirmed an X/XY mosaic complement. Histologically, the gonadal tissue was testicular. Severe autolysis prohibited successful analysis in the 2 remaining cases. In summary, molecular cytogenetic evaluation of gonadal tissue from individuals with sex chromosomal and/or gonadal disorders did not reveal tissue-specific anomalies which could account for differences observed pathologically.

  10. Interspecies complementation analysis of xeroderma pigmentosum and UV-sensitive Chinese hamster cells

    International Nuclear Information System (INIS)

    Stefanini, M.; Keijzer, W.; Westerveld, A.; Bootsma, D.

    1985-01-01

    Complementation analysis was performed 24 h after fusion of UV-sensitive CHO cells (CHO 12 RO) with XP cells of complementation groups A, B, C, D, F and G. The parental cells are characterized by low levels of unscheduled DNA synthesis (UDS). In all combinations, the UDS levels observed in heterokaryons were higher than those in parental mutant cells, clearly indicating cooperation of human and Chinese hamster repair functions. In heterokaryons of CHO 12 RO with XP-A and XP-C cells, the UDS values reached about the normal human level, whereas in heterokaryons with XP-B, XP-D and XP-F, UDS was restored at a level approaching that in wild-type CHO cells. The results obtained after fusion of CHO cells with two representative cell strains from the XP-G group, XP 2 BI and XP 3 BR, were inconsistent. Fusion with XP 3 BR cells yielded UDS levels ranging from wild-type Chinese hamster to normal human, whereas fusion with XP 2 BI cells resulted in a slight increase in UDS which even after 48 h remained below the level found in wild-type CHO cells. The occurrence of complementation in these interspecies heterokaryons indicates that the genetic defect in the CHO 12 RO cells is different from the defects in the XP complementation groups tested

  11. Dengue-Immune Humans Have Higher Levels of Complement-Independent Enhancing Antibody than Complement-Dependent Neutralizing Antibody.

    Science.gov (United States)

    Yamanaka, Atsushi; Konishi, Eiji

    2017-09-25

    Dengue is the most important arboviral disease worldwide. We previously reported that most inhabitants of dengue-endemic countries who are naturally immune to the disease have infection-enhancing antibodies whose in vitro activity does not decrease in the presence of complement (complement-independent enhancing antibodies, or CiEAb). Here, we compared levels of CiEAb and complement-dependent neutralizing antibodies (CdNAb) in dengue-immune humans. A typical antibody dose-response pattern obtained in our assay system to measure the balance between neutralizing and enhancing antibodies showed both neutralizing and enhancing activities depending on serum dilution factor. The addition of complement to the assay system increased the activity of neutralizing antibodies at lower dilutions, indicating the presence of CdNAb. In contrast, similar dose-response curves were obtained with and without complement at higher dilutions, indicating higher levels of CiEAb than CdNAb. For experimental support for the higher CiEAb levels, a cocktail of mouse monoclonal antibodies against dengue virus type 1 was prepared. The antibody dose-response curves obtained in this assay, with or without complement, were similar to those obtained with human serum samples when a high proportion of D1-V-3H12 (an antibody exhibiting only enhancing activity and thus a model for CiEAb) was used in the cocktail. This study revealed higher-level induction of CiEAb than CdNAb in humans naturally infected with dengue viruses.

  12. Effects of β-glucan polysaccharide revealed by the dominant lethal assay and micronucleus assays, and reproductive performance of male mice exposed to cyclophosphamide

    Directory of Open Access Journals (Sweden)

    Rodrigo Juliano Oliveira

    2014-01-01

    Full Text Available β-glucan is a well-known polysaccharide for its chemopreventive effect. This study aimed to evaluate the chemopreventive ability of β-glucan in somatic and germ cells through the dominant lethal and micronucleus assays, and its influence on the reproductive performance of male mice exposed to cyclophosphamide. The results indicate that β-glucan is capable of preventing changes in DNA in both germ cells and somatic ones. Changes in germ cells were evaluated by the dominant lethal assay and showed damage reduction percentages of 46.46% and 43.79% for the doses of 100 and 150 mg/kg. For the somatic changes, evaluated by micronucleus assay in peripheral blood cells in the first week of treatment, damage reduction percentages from 80.63-116.32% were found. In the fifth and sixth weeks, the percentage ranged from 10.20-52.54% and -0.95-62.35%, respectively. Besides the chemopreventive efficiency it appears that the β-glucan, when combined with cyclophosphamide, is able to improve the reproductive performance of males verified by the significant reduction in rates of post-implantation losses and reabsorption in the mating of nulliparous females with males treated with cyclophosphamide.

  13. Changes in buccal micronucleus cytome parameters associated with smokeless tobacco and pesticide exposure among female tea garden workers of Assam, India.

    Science.gov (United States)

    Kausar, Afifa; Giri, Sarbani; Roy, Prasenjit; Giri, Anirudha

    2014-03-01

    Assam is the highest tea producing state in India. A large number of workers are engaged in various units of tea industry. There are few reports on the health status of the tea garden workers. The present cytogenetic biomonitoring study was undertaken to investigate the genotoxic effect associated with workers in tea industries in southern Assam. Smokeless tobacco chewing along with betel nut is very common practice among the workers. Workers also get exposed periodically to mixture of pesticides. Employing buccal micronucleus cytome assay, exfoliated buccal cells were analyzed in 90 female tea garden and compared to 90 age and sex matched non-chewer control as well as 70 chewers who are not tea garden workers. Statistically significant (pworkers compared to both the control groups. The frequency of cell proliferation biomarkers was highest in the chewer controls whereas genotoxic and cell death parameters were highest in tea garden workers. Linear correlation analysis revealed strong positive correlation between the duration of occupation and the frequency of micronucleus (r=0.597; pworkers was relatively lower compared to the control group. Pesticide exposure and chewing areca nut along with smokeless tobacco use may be responsible for changes in cytome parameters in exfoliated buccal cells. Copyright © 2013 Elsevier GmbH. All rights reserved.

  14. Human Secretory IgM Antibodies Activate Human Complement and Offer Protection at Mucosal Surface.

    Science.gov (United States)

    Michaelsen, T E; Emilsen, S; Sandin, R H; Granerud, B K; Bratlie, D; Ihle, O; Sandlie, I

    2017-01-01

    IgM molecules circulate in serum as large polymers, mainly pentamers, which can be transported by the poly-Ig receptor (pIgR) across epithelial cells to mucosal surfaces and released as secretory IgM (SIgM). The mucosal SIgM molecules have non-covalently attached secretory component (SC), which is the extracellular part of pIgR which is cleaved from the epithelial cell membrane. Serum IgM antibodies do not contain SC and have previously been shown to make a conformational change from 'a star' to a 'staple' conformation upon reaction with antigens on a cell surface, enabling them to activate complement. However, it is not clear whether SIgM similarly can induce complement activation. To clarify this issue, we constructed recombinant chimeric (mouse/human) IgM antibodies against hapten 5-iodo-4-hydroxy-3-nitro-phenacetyl (NIP) and in addition studied polyclonal IgM formed after immunization with a meningococcal group B vaccine. The monoclonal and polyclonal IgM molecules were purified by affinity chromatography on a column containing human SC in order to isolate joining-chain (J-chain) containing IgM, followed by addition of excess amounts of soluble SC to create SIgM (IgM J+ SC+). These SIgM preparations were tested for complement activation ability and shown to be nearly as active as the parental IgM J+ molecules. Thus, SIgM may offer protection against pathogens at mucosal surface by complement-mediated cell lysis or by phagocytosis mediated by complement receptors present on effector cells on mucosa. © 2016 The Foundation for the Scandinavian Journal of Immunology.

  15. A novel method for direct measurement of complement convertases activity in human serum

    NARCIS (Netherlands)

    Blom, A.M.; Volokhina, E.B.; Fransson, V.; Stromberg, P.; Berghard, L.; Viktorelius, M.; Mollnes, T.E.; Lopez-Trascasa, M.; Heuvel, B. van den; Goodship, T.H.; Marchbank, K.J.; Okroj, M.

    2014-01-01

    Complement convertases are enzymatic complexes that play a central role in sustaining and amplification of the complement cascade. Impairment of complement function leads directly or indirectly to pathological conditions, including higher infection rate, kidney diseases, autoimmune- or

  16. Complement in the Initiation and Evolution of Rheumatoid Arthritis

    Science.gov (United States)

    Holers, V. Michael; Banda, Nirmal K.

    2018-01-01

    The complement system is a major component of the immune system and plays a central role in many protective immune processes, including circulating immune complex processing and clearance, recognition of foreign antigens, modulation of humoral and cellular immunity, removal of apoptotic and dead cells, and engagement of injury resolving and tissue regeneration processes. In stark contrast to these beneficial roles, however, inadequately controlled complement activation underlies the pathogenesis of human inflammatory and autoimmune diseases, including rheumatoid arthritis (RA) where the cartilage, bone, and synovium are targeted. Recent studies of this disease have demonstrated that the autoimmune response evolves over time in an asymptomatic preclinical phase that is associated with mucosal inflammation. Notably, experimental models of this disease have demonstrated that each of the three major complement activation pathways plays an important role in recognition of injured joint tissue, although the lectin and amplification pathways exhibit particularly impactful roles in the initiation and amplification of damage. Herein, we review the complement system and focus on its multi-factorial role in human patients with RA and experimental murine models. This understanding will be important to the successful integration of the emerging complement therapeutics pipeline into clinical care for patients with RA. PMID:29892280

  17. Determinism and Contingency Shape Metabolic Complementation in an Endosymbiotic Consortium.

    Science.gov (United States)

    Ponce-de-Leon, Miguel; Tamarit, Daniel; Calle-Espinosa, Jorge; Mori, Matteo; Latorre, Amparo; Montero, Francisco; Pereto, Juli

    2017-01-01

    Bacterial endosymbionts and their insect hosts establish an intimate metabolic relationship. Bacteria offer a variety of essential nutrients to their hosts, whereas insect cells provide the necessary sources of matter and energy to their tiny metabolic allies. These nutritional complementations sustain themselves on a diversity of metabolite exchanges between the cell host and the reduced yet highly specialized bacterial metabolism-which, for instance, overproduces a small set of essential amino acids and vitamins. A well-known case of metabolic complementation is provided by the cedar aphid Cinara cedri that harbors two co-primary endosymbionts, Buchnera aphidicola BCc and Ca . Serratia symbiotica SCc, and in which some metabolic pathways are partitioned between different partners. Here we present a genome-scale metabolic network (GEM) for the bacterial consortium from the cedar aphid i BSCc. The analysis of this GEM allows us the confirmation of cases of metabolic complementation previously described by genome analysis (i.e., tryptophan and biotin biosynthesis) and the redefinition of an event of metabolic pathway sharing between the two endosymbionts, namely the biosynthesis of tetrahydrofolate. In silico knock-out experiments with i BSCc showed that the consortium metabolism is a highly integrated yet fragile network. We also have explored the evolutionary pathways leading to the emergence of metabolic complementation between reduced metabolisms starting from individual, complete networks. Our results suggest that, during the establishment of metabolic complementation in endosymbionts, adaptive evolution is significant in the case of tryptophan biosynthesis, whereas vitamin production pathways seem to adopt suboptimal solutions.

  18. Micrurus snake venoms activate human complement system and generate anaphylatoxins

    Directory of Open Access Journals (Sweden)

    Tanaka Gabriela D

    2012-01-01

    Full Text Available Abstract Background The genus Micrurus, coral snakes (Serpentes, Elapidae, comprises more than 120 species and subspecies distributed from the south United States to the south of South America. Micrurus snake bites can cause death by muscle paralysis and further respiratory arrest within a few hours after envenomation. Clinical observations show mainly neurotoxic symptoms, although other biological activities have also been experimentally observed, including cardiotoxicity, hemolysis, edema and myotoxicity. Results In the present study we have investigated the action of venoms from seven species of snakes from the genus Micrurus on the complement system in in vitro studies. Several of the Micrurus species could consume the classical and/or the lectin pathways, but not the alternative pathway, and C3a, C4a and C5a were generated in sera treated with the venoms as result of this complement activation. Micrurus venoms were also able to directly cleave the α chain of the component C3, but not of the C4, which was inhibited by 1,10 Phenanthroline, suggesting the presence of a C3α chain specific metalloprotease in Micrurus spp venoms. Furthermore, complement activation was in part associated with the cleavage of C1-Inhibitor by protease(s present in the venoms, which disrupts complement activation control. Conclusion Micrurus venoms can activate the complement system, generating a significant amount of anaphylatoxins, which may assist due to their vasodilatory effects, to enhance the spreading of other venom components during the envenomation process.

  19. Complement activation in astrocytomas: deposition of C4d and patient outcome

    International Nuclear Information System (INIS)

    Mäkelä, Katri; Helén, Pauli; Haapasalo, Hannu; Paavonen, Timo

    2012-01-01

    C4d is a cleavage product of complement component C4 and is considered to serve as a marker for the site of complement activation. In this study C4d staining of grade I-IV astrocytic tumors was studied to explore if there is an association between complement activation and the grade of tumor, or patient survival. Tissue micro-array samples of 102 astrocytomas were stained immunohistochemically. The material consisted of 9 pilocytic astrocytomas and 93 grade II-IV astrocytomas, of which 67 were primary resections and 26 recurrent tumors. The intensity of C4d staining as well as extent of C4d and CD34 staining were evaluated. The intensity of C4d staining was scored semiquantitatively. The extent of the staining was counted morphometrically with a point counting grid yielding a percent of C4d and CD34 positive area of the sample. The intensity and extent of C4d staining increased in grade II-IV diffusely infiltrating astrocytoma tumors in line with the malignancy grade (p = 0.034 and p = 0.016, respectively, Kruskal-Wallis test). However, C4d positive tumor area percentages were higher in grade I pilocytic astrocytomas than in grade II-IV diffusely infiltrating astrocytomas (p = 0.041, Mann–Whitney test). There was a significant correlation between CD34 positive and C4d positive endothelial area fraction in diffusely infiltrating astrocytomas (p < 0.001, Pearson correlation). In these tumors, the increasing intensity of C4d staining was also associated with worsened patient outcome (p = 0.014, log-rank test). The worsening of patient outcome and malignant progression of tumor cells seem to be connected to microenvironmental changes evoked by chronically activated complement

  20. Atypical haemolytic uraemic syndrome associated with a hybrid complement gene.

    Directory of Open Access Journals (Sweden)

    Julian P Venables

    2006-10-01

    Full Text Available BACKGROUND: Sequence analysis of the regulators of complement activation (RCA cluster of genes at chromosome position 1q32 shows evidence of several large genomic duplications. These duplications have resulted in a high degree of sequence identity between the gene for factor H (CFH and the genes for the five factor H-related proteins (CFHL1-5; aliases CFHR1-5. CFH mutations have been described in association with atypical haemolytic uraemic syndrome (aHUS. The majority of the mutations are missense changes that cluster in the C-terminal region and impair the ability of factor H to regulate surface-bound C3b. Some have arisen as a result of gene conversion between CFH and CFHL1. In this study we tested the hypothesis that nonallelic homologous recombination between low-copy repeats in the RCA cluster could result in the formation of a hybrid CFH/CFHL1 gene that predisposes to the development of aHUS. METHODS AND FINDINGS: In a family with many cases of aHUS that segregate with the RCA cluster we used cDNA analysis, gene sequencing, and Southern blotting to show that affected individuals carry a heterozygous CFH/CFHL1 hybrid gene in which exons 1-21 are derived from CFH and exons 22/23 from CFHL1. This hybrid encodes a protein product identical to a functionally significant CFH mutant (c.3572C>T, S1191L and c.3590T>C, V1197A that has been previously described in association with aHUS. CONCLUSIONS: CFH mutation screening is recommended in all aHUS patients prior to renal transplantation because of the high risk of disease recurrence post-transplant in those known to have a CFH mutation. Because of our finding it will be necessary to implement additional screening strategies that will detect a hybrid CFH/CFHL1 gene.

  1. The atmospheric escape at Mars: complementing the scenario

    Science.gov (United States)

    Lilensten, Jean; Simon, Cyril; Barthélémy, Mathieu; Thissen, Roland; Ehrenreich, David; Gronoff, Guillaume; Witasse, Olivier

    2013-04-01

    In the recent years, the presence of dications in the atmospheres of Mars, Venus, Earth and Titan has been modeled and assessed. These studies also suggested that these ions could participate to the escape of the planetary atmospheres because a large fraction of them is unstable and highly ener- getic. When they dissociate, their internal energy is transformed into kinetic energy which may be larger than the escape energy. This study assesses the impact of the doubly-charged ions in the escape of CO2-dominated planetary atmospheres and to compare it to the escape of thermal photo-ions.We solve a Boltzmann transport equation at daytime taking into account the dissociative states of CO++ for a simplified single constituent atmosphere of a 2 case-study planet. We compute the escape of fast ions using a Beer-Lambert approach. We study three test-cases. On a Mars-analog planet in today's conditions, we retrieve the measured electron escape flux. When comparing the two mechanisms (i.e. excluding solar wind effects, sputtering ...), the escape due to the fast ions issuing from the dissociation of dications may account for up to 6% of the total and the escape of thermal ions for the remaining. We show that these two mechanisms cannot explain the escape of the atmosphere since the magnetic field vanished but complement the other processes and allow writing the scenario of the Mars escape. We show that the atmosphere of a Mars analog planet would empty in another giga years and a half. At Venus orbit, the contribution of the dications in the escape rate is negligible.When simulating the hot Jupiter HD209458b, the two processes cannot explain the measured escape flux of C+.

  2. Alcohol and cannabis use among college students: Substitutes or complements?

    Science.gov (United States)

    O'Hara, Ross E; Armeli, Stephen; Tennen, Howard

    2016-07-01

    Economists debate whether changes in availability of alcohol or cannabis are positively or negatively related to changes in use of the other substance. Implicit in these arguments are two competing, individual-level hypotheses-that people use alcohol and cannabis either as complements or substitutes for one another. This is the first study to test these hypotheses using micro-longitudinal data on individuals' alcohol and cannabis use on a given evening. United States college students who use alcohol and cannabis (n=876) were selected from a larger sample who participated in a 30-day online daily diary study. At baseline, students reported their proclivity to use alcohol/drugs to cope with stress. Each day students reported their level of alcohol use from the prior evening as well as whether they had used cannabis. Evening levels of alcohol use and mean levels of alcohol use positively predicted the likelihood of evening cannabis use, results indicative of complementary use. This relation, however, was moderated by coping style, such that students who were more likely to use alcohol/drugs to cope were less likely to use cannabis as their evening or mean alcohol use levels increased, results indicative of substitution. Substance-using college students showed evidence for complementary alcohol and cannabis use at both the within- and between-person levels. Students with a proclivity toward using alcohol/drugs to cope, however, showed evidence of substitution. These findings suggest that studies based on economic theories of substance use should take into account individual differences in substance use motives. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. How regional non-proliferation arrangements complement international verification

    International Nuclear Information System (INIS)

    Carlson, J.

    1999-01-01

    This presentation focuses on international verification in the form of IAEA Safeguards, and discusses the relationship between IAEA safeguards and the relevant regional arrangements, both the existing and the future. For most States the political commitment against acquisition of nuclear weapons has been carefully reached and strongly held. Their observance of treaty commitments does not depend on the deterrent effect of verification activities. Safeguards serve to assist States who recognise it is in their own interest to demonstrate their compliance to others. Thus safeguards are a vital confidence building measure in their own right, as well as being a major complement to the broader range of international confidence building measures. Safeguards can both complement other confidence building measures and in turn be complemented by them. Within consideration of how it could work it is useful to consider briefly current developments of IAEA safeguards, i.e. existing regional arrangements and nuclear weapon free zones

  4. Lessons learned from mice deficient in lectin complement pathway molecules

    DEFF Research Database (Denmark)

    Genster, Ninette; Takahashi, Minoru; Sekine, Hideharu

    2014-01-01

    in turn activate downstream complement components, ultimately leading to elimination of the pathogen. Mice deficient in the key molecules of lectin pathway of complement have been generated in order to build knowledge of the molecular mechanisms of the lectin pathway in health and disease. Despite......The lectin pathway of the complement system is initiated when the pattern-recognition molecules, mannose-binding lectin (MBL), ficolins or collectin-11, bind to invading pathogens or damaged host cells. This leads to activation of MBL/ficolin/collectin-11 associated serine proteases (MASPs), which...... differences in the genetic arrangements of murine and human orthologues of lectin pathway molecules, the knockout mice have proven to be valuable models to explore the effect of deficiency states in humans. In addition, new insight and unexpected findings on the diverse roles of lectin pathway molecules...

  5. Role of complement in porphyrin-induced photosensitivity

    International Nuclear Information System (INIS)

    Lim, H.W.; Gigli, I.

    1981-01-01

    Addition of porphyrins to sera of guinea pigs in vitro, followed by irradiation with 405 nm light, resulted in dose-dependent inhibitions of hemolytic activity of complement. With guinea pig as an animal model, we also found that systemically administered porphyrins, followed by irradiation with 405 nm light, resulted in dose-dependent inhibition of CH50 in vivo. The erythrocytes from porphyrin-treated guinea pigs showed an increased susceptibility to hemolysis induced by 405 nm irradiation in vitro. Clinical changes in these animals were limited to light-exposed areas and consisted of erythema, crusting, and delayed growth of hair. Histologically, dermal edema, dilation of blood vessels, and infiltration of mononuclear and polymorphonuclear cells were observed. Guinea pigs irradiated with ultraviolet-B developed erythema, but had no alteration of their complement profiles. It is suggested that complement products may play a specific role in the pathogenesis of the cutaneous lesions of some porphyrias

  6. Physical properties of the Schur complement of local covariance matrices

    International Nuclear Information System (INIS)

    Haruna, L F; Oliveira, M C de

    2007-01-01

    General properties of global covariance matrices representing bipartite Gaussian states can be decomposed into properties of local covariance matrices and their Schur complements. We demonstrate that given a bipartite Gaussian state ρ 12 described by a 4 x 4 covariance matrix V, the Schur complement of a local covariance submatrix V 1 of it can be interpreted as a new covariance matrix representing a Gaussian operator of party 1 conditioned to local parity measurements on party 2. The connection with a partial parity measurement over a bipartite quantum state and the determination of the reduced Wigner function is given and an operational process of parity measurement is developed. Generalization of this procedure to an n-partite Gaussian state is given, and it is demonstrated that the n - 1 system state conditioned to a partial parity projection is given by a covariance matrix such that its 2 x 2 block elements are Schur complements of special local matrices

  7. Variants in Complement Factor H and Complement Factor H-Related Protein Genes, CFHR3 and CFHR1, Affect Complement Activation in IgA Nephropathy.

    Science.gov (United States)

    Zhu, Li; Zhai, Ya-Ling; Wang, Feng-Mei; Hou, Ping; Lv, Ji-Cheng; Xu, Da-Min; Shi, Su-Fang; Liu, Li-Jun; Yu, Feng; Zhao, Ming-Hui; Novak, Jan; Gharavi, Ali G; Zhang, Hong

    2015-05-01

    Complement activation is common in patients with IgA nephropathy (IgAN) and associated with disease severity. Our recent genome-wide association study of IgAN identified susceptibility loci on 1q32 containing the complement regulatory protein-encoding genes CFH and CFHR1-5, with rs6677604 in CFH as the top single-nucleotide polymorphism and CFHR3-1 deletion (CFHR3-1∆) as the top signal for copy number variation. In this study, to explore the clinical effects of variation in CFH, CFHR3, and CFHR1 on IgAN susceptibility and progression, we enrolled two populations. Group 1 included 1178 subjects with IgAN and available genome-wide association study data. Group 2 included 365 subjects with IgAN and available clinical follow-up data. In group 1, rs6677604 was associated with mesangial C3 deposition by genotype-phenotype correlation analysis. In group 2, we detected a linkage between the rs6677604-A allele and CFHR3-1∆ and found that the rs6677604-A allele was associated with higher serum levels of CFH and lower levels of the complement activation split product C3a. Furthermore, CFH levels were positively associated with circulating C3 levels and negatively associated with mesangial C3 deposition. Moreover, serum levels of the pathogenic galactose-deficient glycoform of IgA1 were also associated with the degree of mesangial C3 deposition in patients with IgAN. Our findings suggest that genetic variants in CFH, CFHR3, and CFHR1 affect complement activation and thereby, predispose patients to develop IgAN. Copyright © 2015 by the American Society of Nephrology.

  8. Functional analysis of Ficolin-3 mediated complement activation

    DEFF Research Database (Denmark)

    Hein, Estrid; Honoré, Christian Le Fèvre; Skjoedt, Mikkel-Ole

    2010-01-01

    assessed by C4, C3 and terminal complement complex (TCC) deposition. Serum Ficolin-3 bound to acBSA in a calcium dependent manner, while only minimal binding of Ficolin-2 and no binding of Ficolin-1 were observed. No binding to normal BSA was seen for any of the Ficolins. Serum C4, C3 and TCC deposition...... was applied to the samples that inhibited interference from the classical pathway due to the presence of anti-BSA antibodies in some sera. We describe a novel functional method for measuring complement activation mediated by Ficolin-3 in human serum up to the formation of TCC. The assay provides...

  9. The Complement System: A Prey of Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Kárita C. F. Lidani

    2017-04-01

    Full Text Available Trypanosoma cruzi is a protozoan parasite known to cause Chagas disease (CD, a neglected sickness that affects around 6–8 million people worldwide. Originally, CD was mainly found in Latin America but more recently, it has been spread to countries in North America, Asia, and Europe due the international migration from endemic areas. Thus, at present CD represents an important concern of global public health. Most of individuals that are infected by T. cruzi may remain in asymptomatic form all lifelong, but up to 40% of them will develop cardiomyopathy, digestive mega syndromes, or both. The interaction between the T. cruzi infective forms and host-related immune factors represents a key point for a better understanding of the physiopathology of CD. In this context, the complement, as one of the first line of host defense against infection was shown to play an important role in recognizing T. cruzi metacyclic trypomastigotes and in controlling parasite invasion. The complement consists of at least 35 or more plasma proteins and cell surface receptors/regulators, which can be activated by three pathways: classical (CP, lectin (LP, and alternative (AP. The CP and LP are mainly initiated by immune complexes or pathogen-associated molecular patterns (PAMPs, respectively, whereas AP is spontaneously activated by hydrolysis of C3. Once activated, several relevant complement functions are generated which include opsonization and phagocytosis of particles or microorganisms and cell lysis. An important step during T. cruzi infection is when intracellular trypomastigotes are release to bloodstream where they may be target by complement. Nevertheless, the parasite uses a sequence of events in order to escape from complement-mediated lysis. In fact, several T. cruzi molecules are known to interfere in the initiation of all three pathways and in the assembly of C3 convertase, a key step in the activation of complement. Moreover, T. cruzi promotes secretion

  10. Reincarnation of ancient links between coagulation and complement.

    Science.gov (United States)

    Conway, E M

    2015-06-01

    Throughout evolution, organisms have developed means to contain wounds by simultaneously limiting bleeding and eliminating pathogens and damaged host cells via the recruitment of innate defense mechanisms. Disease emerges when there is unchecked activation of innate immune and/or coagulation responses. A key component of innate immunity is the complement system. Concurrent excess activation of coagulation and complement - two major blood-borne proteolytic pathways - is evident in numerous diseases, including atherosclerosis, diabetes, venous thromboembolic disease, thrombotic microangiopathies, arthritis, cancer, and infectious diseases. Delineating the cross-talk between these two cascades will uncover novel therapeutic insights. © 2015 International Society on Thrombosis and Haemostasis.

  11. Graphistrength© C100 MultiWalled Carbon Nanotubes (MWCNT): thirteen-week inhalation toxicity study in rats with 13- and 52-week recovery periods combined with comet and micronucleus assays

    International Nuclear Information System (INIS)

    Régnier, Jean-François; Pothmann-Krings, Daniela; Simar, Sophie; Dony, Eva; Net, Jean-Loïc Le; Beausoleil, Julien

    2017-01-01

    Graphistrength© C100 provides superior electrical and mechanical properties for various applications and is one of the industrial MWCNT referenced in the OECD sponsorship program for the safety testing of nanomaterials. Graphistrength© C100 is formed of MWCNT (ca. 12 walls, outer mean diameter ca. 12 nm, length ca. 1 µm) agglomerated in particles with a granulometry centered on 400 µm. A general feature of MWCNT after inhalation or intratracheal exposures is the induction of an inflammatory reaction in the lungs sometimes associated with local genotoxic effects. Most of the in vitro and in vivo genotoxicity data available on Graphistrength© C100 are negative. However, a weak DNA damage activity in the in vitro and in vivo FPG-modified Comet assays and a weak clastogenic effect in the in vitr o micronucleus test were reported. After investigating different parameters for the aerosol generation, male and female Wistar rats were exposed by nose-only inhalation (6h/day, 5d/week) to target concentrations of 0.05, 0.25 and 5.0 mg/m 3 air of a respirable aerosol (MMAD < 3 µm) and sacrificed immediately after 4 and 13 weeks of exposure and 13 and 52 weeks of recovery after the 13-week exposure. Clinical, biological and histological evaluations were performed according to the OECD TG 413. Broncho-alveolar lavage fluid (BALF) was collected and analysed for cytokines and inflammatory parameters. Immediately after 13 weeks of exposure, chromosomal aberrations in the bone marrow cells of males and females were evaluated by the micronucleus test (OECD TG 474) and DNA damage in the lung, kidney and liver cells of males were assessed by both the standard and the human 8-oxoguanine DNA N-glycosylase 1 (hOGG1)-modified comet assay (OECD TG 489). Concentration-related deposition of black particles (MWCNT) was observed in lungs. At all sacrifice periods, an inflammatory lung reaction was observed in rats exposed to 5.0 mg/m 3 associated with changes in the differential white

  12. Graphistrength© C100 MultiWalled Carbon Nanotubes (MWCNT): thirteen-week inhalation toxicity study in rats with 13- and 52-week recovery periods combined with comet and micronucleus assays

    Science.gov (United States)

    Régnier, Jean-François; Pothmann-Krings, Daniela; Simar, Sophie; Dony, Eva; Le Net, Jean-Loïc; Beausoleil, Julien

    2017-06-01

    Graphistrength© C100 provides superior electrical and mechanical properties for various applications and is one of the industrial MWCNT referenced in the OECD sponsorship program for the safety testing of nanomaterials. Graphistrength© C100 is formed of MWCNT (ca. 12 walls, outer mean diameter ca. 12 nm, length ca. 1 µm) agglomerated in particles with a granulometry centered on 400 µm. A general feature of MWCNT after inhalation or intratracheal exposures is the induction of an inflammatory reaction in the lungs sometimes associated with local genotoxic effects. Most of the in vitro and in vivo genotoxicity data available on Graphistrength© C100 are negative. However, a weak DNA damage activity in the in vitro and in vivo FPG-modified Comet assays and a weak clastogenic effect in the in vitro micronucleus test were reported. After investigating different parameters for the aerosol generation, male and female Wistar rats were exposed by nose-only inhalation (6h/day, 5d/week) to target concentrations of 0.05, 0.25 and 5.0 mg/m3 air of a respirable aerosol (MMAD males and females were evaluated by the micronucleus test (OECD TG 474) and DNA damage in the lung, kidney and liver cells of males were assessed by both the standard and the human 8-oxoguanine DNA N-glycosylase 1 (hOGG1)-modified comet assay (OECD TG 489). Concentration-related deposition of black particles (MWCNT) was observed in lungs. At all sacrifice periods, an inflammatory lung reaction was observed in rats exposed to 5.0 mg/m3 associated with changes in the differential white blood cells counts. The lung inflammation was characterized by changes in the cytological, biochemical and cytokine parameters of the BALF, an increase of the lung weight, an interstitial inflammation mainly around the alveolar ducts at the bronchiole-alveolar junction and a cell hypertrophy/hyperplasia in the terminal and respiratory bronchioles. The slight changes in BALF parameters observed at 0.25 mg/m3 recovered after

  13. Diprosopus tetraophthalmus: CT as a complement to autopsy

    OpenAIRE

    Laor, T; Stanek, J; Leach, J L

    2012-01-01

    Diprosopus is the rarest form of conjoined twinning. This anomaly is characterised by craniofacial duplication to varying degrees and is associated with anomalies of the central nervous, cardiac, respiratory and musculoskeletal systems. We present an infant characterised as diprosopus tetraophthalmus who underwent post-mortem CT, which served as a highly useful complement to autopsy.

  14. Diprosopus tetraophthalmus: CT as a complement to autopsy.

    Science.gov (United States)

    Laor, T; Stanek, J; Leach, J L

    2012-01-01

    Diprosopus is the rarest form of conjoined twinning. This anomaly is characterised by craniofacial duplication to varying degrees and is associated with anomalies of the central nervous, cardiac, respiratory and musculoskeletal systems. We present an infant characterised as diprosopus tetraophthalmus who underwent post-mortem CT, which served as a highly useful complement to autopsy.

  15. Schizophrenia risk from complex variation of complement component 4

    DEFF Research Database (Denmark)

    Sekar, Aswin; Bialas, Allison R; de Rivera, Heather

    2016-01-01

    to identify. Here we show that this association arises in part from many structurally diverse alleles of the complement component 4 (C4) genes. We found that these alleles generated widely varying levels of C4A and C4B expression in the brain, with each common C4 allele associating with schizophrenia...

  16. Staphylococcal Proteases Aid in Evasion of the Human Complement System

    DEFF Research Database (Denmark)

    Jusko, Monika; Potempa, Jan; Kantyka, Tomasz

    2014-01-01

    Staphylococcus aureus is an opportunistic pathogen that presents severe health care concerns due to the prevalence of multiple antibiotic-resistant strains. New treatment strategies are urgently needed, which requires an understanding of disease causation mechanisms. Complement is one of the first...

  17. The complemental role of dryland cultivated pastures in market ...

    African Journals Online (AJOL)

    The complemental role of dryland cultivated pastures in market-related beef production from semi-arid rangeland. ... Abstract. Rangeland condition is a decisive factor in determining the income/cost ratio of production hence in the profitability of any beef production enterprise. Cultivated pastures can play an important role in ...

  18. Construction of a bimolecular fluorescence complementation (BiFC ...

    African Journals Online (AJOL)

    Protein–protein interactions are essential for signal transduction in cells. Bimolecular fluorescence complementation (BiFC) is a novel technology that utilises green fluorescent proteins to visualize protein–protein interactions and subcellular protein localisation. BiFC based on pSATN vectors are a good system for ...

  19. The Importance of Being a Complement: CED Effects Revisited

    Science.gov (United States)

    Jurka, Johannes

    2010-01-01

    This dissertation revisits subject island effects (Ross 1967, Chomsky 1973) cross-linguistically. Controlled acceptability judgment studies in German, English, Japanese and Serbian show that extraction out of specifiers is consistently degraded compared to extraction out of complements, indicating that the Condition on Extraction domains (CED,…

  20. Complement Levels and Haemate-Biochemical Parameters as ...

    African Journals Online (AJOL)

    Complement levels and haemato-biochemical parameters in West African Dwarf (WAD) and Borno White (BW) goats experimentally infected with Trypanosoma congolense were investigated. Parasitaemia was established in both breeds of goats by day 7 post-infection. Peak parasitaemia of 7.5 x 103/µL for WAD goats was ...

  1. X-linked inheritance of Fanconi anemia complementation group B.

    NARCIS (Netherlands)

    Meetei, AR; Levitus, M.; Xue, Y; Medhurst, A.L. dr.; Zwaan, M.; Ling, C; Rooimans, M.A.; Bier, P; Hoatlin, M.; Pals, G.; Winter, de J.P.; Joenje, H.

    2004-01-01

    Fanconi anemia is an autosomal recessive syndrome characterized by diverse clinical symptoms, hypersensitivity to DNA crosslinking agents, chromosomal instability and susceptibility to cancer. Fanconi anemia has at least 11 complementation groups (A, B, C, D1, D2, E, F, G, I, J, L); the genes

  2. Deciphering complement mechanisms: The contributions of structural biology.

    NARCIS (Netherlands)

    Arlaud, G.J.; Barlow, P.N.; Gaboriaud, C.; Gros, P.; Narayana, S.V.L.

    2007-01-01

    Since the resolution of the first three-dimensional structure of a complement component in 1980, considerable efforts have been put into the investigation of this system through structural biology techniques, resulting in about a hundred structures deposited in the Protein Data Bank by the beginning

  3. Multiple complementizers in Modern Danish and Middle English

    DEFF Research Database (Denmark)

    Nyvad, Anne Mette

    2016-01-01

    This paper expands the empirical coverage of the cP/CP-distinction proposed by Nyvad, Christensen & Vikner (2015) by applying it to a range of embedded clause types involving multiple complementizers in Middle English and Modern Danish, and offering a uniform analysis. Due to the fact that a number...

  4. Complement activation by cholesterol crystals triggers a subsequent cytokine response

    DEFF Research Database (Denmark)

    Niyonzima, Nathalie; Halvorsen, Bente; Sporsheim, Bjørnar

    2017-01-01

    beneficial effects on atherosclerosis and a large clinical trial with an IL-1β inhibitor is currently in progress (the CANTOS study). However, upstream inhibition of CC-induced inflammation by using a complement inhibitor may be more efficient in treating atherosclerosis since this will block initiation...

  5. Dynamics of human complement-mediated killing of Klebsiella pneumoniae.

    Science.gov (United States)

    Nypaver, Christina M; Thornton, Margaret M; Yin, Suellen M; Bracho, David O; Nelson, Patrick W; Jones, Alan E; Bortz, David M; Younger, John G

    2010-11-01

    With an in vitro system that used a luminescent strain of Klebsiella pneumoniae to assess bacterial metabolic activity in near-real-time, we investigated the dynamics of complement-mediated attack in healthy individuals and in patients presenting to the emergency department with community-acquired severe sepsis. A novel mathematical/statistical model was developed to simplify light output trajectories over time into two fitted parameters, the rate of complement activation and the delay from activation to the onset of killing. Using Factor B-depleted serum, the alternative pathway was found to be the primary bactericidal effector: In the absence of B, C3 opsonization as measured by flow cytometry did not progress and bacteria proliferated near exponentially. Defects in bacterial killing were easily demonstrable in patients with severe sepsis compared with healthy volunteers. In most patients with sepsis, the rate of activation was higher than in normal subjects but was associated with a prolonged delay between activation and bacterial killing (P < 0.05 for both). Theoretical modeling suggested that this combination of accentuated but delayed function should allow successful bacterial killing but with significantly greater complement activation. The use of luminescent bacteria allowed for the development of a novel and powerful tool for assessing complement immunology for the purposes of mechanistic study and patient evaluation.

  6. Children's Understanding of the Addition/Subtraction Complement Principle

    Science.gov (United States)

    Torbeyns, Joke; Peters, Greet; De Smedt, Bert; Ghesquière, Pol; Verschaffel, Lieven

    2016-01-01

    Background: In the last decades, children's understanding of mathematical principles has become an important research topic. Different from the commutativity and inversion principles, only few studies have focused on children's understanding of the addition/subtraction complement principle (if a - b = c, then c + b = a), mainly relying on verbal…

  7. Consequences of dysregulated complement regulators on red blood cells

    NARCIS (Netherlands)

    Thielen, Astrid J. F.; Zeerleder, Sacha; Wouters, Diana

    2018-01-01

    The complement system represents the first line of defense that is involved in the clearance of pathogens, dying cells and immune complexes via opsonization, induction of an inflammatory response and the formation of a lytic pore. Red blood cells (RBCs) are very important for the delivery of oxygen

  8. Activation of the lectin complement pathway on human renal ...

    African Journals Online (AJOL)

    This study aimed to investigate the roles of high glucose and mannose-binding lectin (MBL) on the activation of the lectin complement pathway (LCP) on human renal glomerular endothelial cells (HRGECs) in vitro. Flow cytometry analysis, immunofluorescence staining and Western blot were used to detect the cell surface ...

  9. High protein complementation with high fiber substrates for oyster ...

    African Journals Online (AJOL)

    Agricultural residues have been world widely accepted for oyster mushroom culture. In this study, we used wheat straw, barley straw, maize stem residue, and lawn residue as substrates coupled with wheat bran, rice bran and soybean powder as complements for the growth of Pleurotus florida and Pleurotus ostreatus as ...

  10. Word order variation and foregrounding of complement clauses

    DEFF Research Database (Denmark)

    Christensen, Tanya Karoli; Jensen, Torben Juel

    2015-01-01

    Through mixed models analyses of complement clauses in a corpus of spoken Danish we examine the role of sentence adverbials in relation to a word order distinction in Scandinavian signalled by the relative position of sentence adverbials and finite verb (V>Adv vs. Adv>V). The type of sentence...

  11. Comparison of complement fixation and ELISA for diagnosis of foot-and-mouth disease

    International Nuclear Information System (INIS)

    Caballero, P.H.; Gonzalez, S.; Orue, P.M.; Vergara, N.N.

    1998-01-01

    Foot-and-mouth disease (FMD) virus is characterised by its rapid transmission and its great antigenic variability which require a requires a rapid and accurate diagnosis in the laboratory, in order to initiate an immediate response for control. From these studies it is clear that Enzyme linked immunosorbent assay (ELISA) has the advantage over the Complement fixation test (CFT) of being a test of high sensitivity and specificity. Therefore, this technique is now used in our laboratory for diagnosis to detect FMD virus (O-A-C) in epithelia from animals affected by the disease. (author)

  12. Complement drives glucosylceramide accumulation and tissue inflammation in Gaucher disease.

    Science.gov (United States)

    Pandey, Manoj K; Burrow, Thomas A; Rani, Reena; Martin, Lisa J; Witte, David; Setchell, Kenneth D; Mckay, Mary A; Magnusen, Albert F; Zhang, Wujuan; Liou, Benjamin; Köhl, Jörg; Grabowski, Gregory A

    2017-03-02

    Gaucher disease is caused by mutations in GBA1, which encodes the lysosomal enzyme glucocerebrosidase (GCase). GBA1 mutations drive extensive accumulation of glucosylceramide (GC) in multiple innate and adaptive immune cells in the spleen, liver, lung and bone marrow, often leading to chronic inflammation. The mechanisms that connect excess GC to tissue inflammation remain unknown. Here we show that activation of complement C5a and C5a receptor 1 (C5aR1) controls GC accumulation and the inflammatory response in experimental and clinical Gaucher disease. Marked local and systemic complement activation occurred in GCase-deficient mice or after pharmacological inhibition of GCase and was associated with GC storage, tissue inflammation and proinflammatory cytokine production. Whereas all GCase-inhibited mice died within 4-5 weeks, mice deficient in both GCase and C5aR1, and wild-type mice in which GCase and C5aR were pharmacologically inhibited, were protected from these adverse effects and consequently survived. In mice and humans, GCase deficiency was associated with strong formation of complement-activating GC-specific IgG autoantibodies, leading to complement activation and C5a generation. Subsequent C5aR1 activation controlled UDP-glucose ceramide glucosyltransferase production, thereby tipping the balance between GC formation and degradation. Thus, extensive GC storage induces complement-activating IgG autoantibodies that drive a pathway of C5a generation and C5aR1 activation that fuels a cycle of cellular GC accumulation, innate and adaptive immune cell recruitment and activation in Gaucher disease. As enzyme replacement and substrate reduction therapies are expensive and still associated with inflammation, increased risk of cancer and Parkinson disease, targeting C5aR1 may serve as a treatment option for patients with Gaucher disease and, possibly, other lysosomal storage diseases.

  13. A follow-up survey of the lymphocyte micronucleus for three victims seventheen years after Shanghai '6.25' 60Co radiation accident

    International Nuclear Information System (INIS)

    Du Jie; Chen Ying; Zhang Xueqing; Liu Xiulin; Yan Xuekun

    2008-01-01

    Objective: To study the long-term effect on lymphocyte micronucleus and its clinical significance for the three victims seventheen years after Shanghai '6.25' 60 Co radiation accident. Method: The MN and MNC frequency were observed by CBMN method. Results: The MN and MNC frequency were still higher than normal even 17 years after the expo- sure. The MN frequency is related with the former radiation dose. The MNC consisting of ≥2MN is the hightest for 'Long', but for 'Jun' it consisted of 1 MN. The MN frequency is lower 17 years after the exposure than that of 5 years, but higher than 10 years. Conclusions: The MN is one of important signs for long-term radiation effect. Special attention should be payed to the high level of MN remaining in the body for so long time. (authors)

  14. Protection of nucleated bone marrow cells of mice against effect of radiation-induced micronucleus formation by using polysaccharides extracted from 'Zi Zhi' (a ganoderma)

    International Nuclear Information System (INIS)

    Chu Fang; Luo Houliang; Luo Gui; Chen Shunle; Liu Zhifang

    1988-01-01

    This paper describes the influence of polysaccharides extracted from 'Zi Zhi' (Ganoderma Sinese Zhao, Xu et Zhang) on the frequency of micronucleated cells induced by 60 Co gamma irradiation at different doses in bone marrow of mice. These polysaccharides of 'Zi Zhi' were shown to be of ability to protect nucleated bone marrow cells from micronucleus formation in irradiated mice. For Swiss mice, a dose reduction factor (DRF) was found to be 1.72 in the range of 0 to 4.728 Gy and for LACA mice, to be 1.73 in the range of 0 to 3.152 Gy. Such findings indicate that these polysaccharides are comparable to L-cysteine in their effeciency of protection

  15. Development of a data-processing method based on Bayesian k-means clustering to discriminate aneugens and clastogens in a high-content micronucleus assay.

    Science.gov (United States)

    Huang, Z H; Li, N; Rao, K F; Liu, C T; Huang, Y; Ma, M; Wang, Z J

    2018-03-01

    Genotoxicants can be identified as aneugens and clastogens through a micronucleus (MN) assay. The current high-content screening-based MN assays usually discriminate an aneugen from a clastogen based on only one parameter, such as the MN size, intensity, or morphology, which yields low accuracies (70-84%) because each of these parameters may contribute to the results. Therefore, the development of an algorithm that can synthesize high-dimensionality data to attain comparative results is important. To improve the automation and accuracy of detection using the current parameter-based mode of action (MoA), the MN MoA signatures of 20 chemicals were systematically recruited in this study to develop an algorithm. The results of the algorithm showed very good agreement (93.58%) between the prediction and reality, indicating that the proposed algorithm is a validated analytical platform for the rapid and objective acquisition of genotoxic MoA messages.

  16. The assessment of micronucleus frequency in lymphocytes in the cohort of coal-miners characterized by different polymorphisms of double strand break reparation genes

    Directory of Open Access Journals (Sweden)

    Maxim Yur'yevich Sinitsky

    2015-12-01

    Full Text Available Background: Coal-miners are exposed to a lot of number of harmful factors (chemical agents, ionizing radiation, heavy metals, coal dust etc.. Material and methods: Venous blood samples extracted from 129 coal-miners. Assessment of cytogenetic damage was performed using the cytokinesis-block micronucleus assay (CBMN on peripheral blood lymphocytes. PCR and gel electrophoresis were used to determine polymorphisms in the genes Lig4 (rs1805388 and XRCC4 (rs6869366. Results: We found a significant increase in the frequency of binucleated lymphocytes with micronuclei (MN and protrusions in carriers of the Ile/ Ile genotype of the Lig4 gene Thr9Ile polymorphism in comparison to Thr/Thr and Thr/Ile genotypes. Conclusions: Thr9Ile polymorphism within Lig4 gene can be used as potential molecular genetic markers of increased individual susceptibility to the complex of harmful factors in coal-mining conditions.

  17. Human genetic deficiencies reveal the roles of complement in the inflammatory network: lessons from nature

    DEFF Research Database (Denmark)

    Lappegård, Knut Tore; Christiansen, Dorte; Pharo, Anne

    2009-01-01

    on CD14 and inversely regulated by complement, that is, complement deficiency and complement inhibition enhanced their release. Granulocyte responses were mainly complement-dependent, whereas monocyte responses were more dependent on CD14. Notably, all responses were abolished by combined neutralization...

  18. Complement factor H deficiency results in decreased neuroretinal expression of Cd59a in aged mice

    DEFF Research Database (Denmark)

    Faber, Carsten; Williams, Jennifer; Juel, Helene Bæk

    2012-01-01

    Purpose. The complement system is closely linked to the pathogenesis of AMD. Several complement genes are expressed in RPE, and complement proteins accumulate in drusen. Further, a common variant of complement factor H (CFH) confers increased risk of developing AMD. Because the mechanisms by which...

  19. The buccal cytome and micronucleus frequency is substantially altered in Down's syndrome and normal ageing compared to young healthy controls

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Philip [CSIRO Human Nutrition, PO Box 10041, Adelaide BC, Adelaide, SA 5000 (Australia); Discipline of Physiology, School of Molecular and Biomedical Sciences, The University of Adelaide, Adelaide, SA 5005 (Australia)], E-mail: philip.thomas@csiro.au; Harvey, Sarah; Gruner, Tini [Southern Cross University, PO Box 157, Lismore, NSW 2480 (Australia); Fenech, Michael [CSIRO Human Nutrition, PO Box 10041, Adelaide BC, Adelaide, SA 5000 (Australia)], E-mail: michael.fenech@csiro.au

    2008-02-01

    The buccal micronucleus cytome assay was used to investigate biomarkers for DNA damage, cell death and basal cell frequency in buccal cells of healthy young, healthy old and young Down's syndrome cohorts. With normal ageing a significant increase in cells with micronuclei (P < 0.05, average increase +366%), karyorrhectic cells (P < 0.001, average increase +439%), condensed chromatin cells (P < 0.01, average increase +45.8%) and basal cells (P < 0.001, average increase +233%) is reported relative to young controls. In Down's syndrome we report a significant increase in cells with micronuclei (P < 0.001, average increase +733%) and binucleated cells (P < 0.001, average increase +84.5%) and a significant decrease in condensed chromatin cells (P < 0.01, average decrease -52%), karyolytic cells (P < 0.001, average decrease -51.8%) and pyknotic cells (P < 0.001, average decrease -75.0%) relative to young controls. These changes show distinct differences between the cytome profile of normal ageing relative to that for a premature ageing syndrome, and highlight the diagnostic value of the cytome approach for measuring the profile of cells with DNA damage, cell death and proportion of cells with proliferative potential (i.e., basal cells). Significant correlations amongst cell death biomarkers observed in this study were used to propose a new model of the inter-relationship of cell types scored within the buccal micronucleus cytome assay. This study validates the use of a cytome approach to investigate DNA damage, cell death and cell proliferation in buccal cells with ageing.

  20. Ontwikkeling van een alternatief voor de Radio Immuno Assay kit ter bepaling van humaan complement factor C3A

    NARCIS (Netherlands)

    Orzechowski TJH; Bisschop A

    1989-01-01

    Due to the present developments in the field of biocompatibility of medical devices, the need for the availability of sensitive test methods with a high predictive value becomes more and more urgent. Commercial available RIA-testkits for measurement of complement activation are very expensive

  1. A potent complement factor C3 specific nanobody inhibiting multiple functions in the alternative pathway of human and murine complement.

    Science.gov (United States)

    Jensen, Rasmus K; Pihl, Rasmus; Gadeberg, Trine A F; Jensen, Jan K; Andersen, Kasper R; Thiel, Steffen; Laursen, Nick S; Andersen, Gregers Rom

    2018-03-01

    The complement system is a complex, carefully regulated proteolytic cascade for which suppression of aberrant activation is of increasing clinical relevance and inhibition of the complement alternative pathway is a subject of intense research. Here, we describe the nanobody hC3Nb1 that binds to multiple functional states of C3 with sub-nanomolar affinity. The nanobody causes a complete shutdown of alternative pathway activity in human and murine serum when present in concentrations comparable to C3, and hC3Nb1 is shown to prevent both proconvertase assembly as well as binding of the C3 substrate to C3 convertases. Our crystal structure of the C3b-hC3Nb1 complex and functional experiments demonstrate that proconvertase formation is blocked by steric hindrance between the nanobody and an Asn-linked glycan on complement factor B. In addition, hC3Nb1 is shown to prevent factor H binding to C3b rationalizing its inhibition of factor I activity. Our results identify hC3Nb1 as a versatile, inexpensive, and powerful inhibitor of the alternative pathway in both human and murine in vitro model systems of complement activation. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

  2. Pasteurella pneumotropica evades the human complement system by acquisition of the complement regulators factor H and C4BP.

    Directory of Open Access Journals (Sweden)

    Alfredo Sahagún-Ruiz

    Full Text Available Pasteurella pneumotropica is an opportunist Gram negative bacterium responsible for rodent pasteurellosis that affects upper respiratory, reproductive and digestive tracts of mammals. In animal care facilities the presence of P. pneumotropica causes severe to lethal infection in immunodeficient mice, being also a potential source for human contamination. Indeed, occupational exposure is one of the main causes of human infection by P. pneumotropica. The clinical presentation of the disease includes subcutaneous abscesses, respiratory tract colonization and systemic infections. Given the ability of P. pneumotropica to fully disseminate in the organism, it is quite relevant to study the role of the complement system to control the infection as well as the possible evasion mechanisms involved in bacterial survival. Here, we show for the first time that P. pneumotropica is able to survive the bactericidal activity of the human complement system. We observed that host regulatory complement C4BP and Factor H bind to the surface of P. pneumotropica, controlling the activation pathways regulating the formation and maintenance of C3-convertases. These results show that P. pneumotropica has evolved mechanisms to evade the human complement system that may increase the efficiency by which this pathogen is able to gain access to and colonize inner tissues where it may cause severe infections.

  3. Test

    DEFF Research Database (Denmark)

    Bendixen, Carsten

    2014-01-01

    Bidrag med en kortfattet, introducerende, perspektiverende og begrebsafklarende fremstilling af begrebet test i det pædagogiske univers.......Bidrag med en kortfattet, introducerende, perspektiverende og begrebsafklarende fremstilling af begrebet test i det pædagogiske univers....

  4. Triatoma infestans Calreticulin: Gene Cloning and Expression of a Main Domain That Interacts with the Host Complement System.

    Science.gov (United States)

    Weinberger, Katherine; Collazo, Norberto; Aguillón, Juan Carlos; Molina, María Carmen; Rosas, Carlos; Peña, Jaime; Pizarro, Javier; Maldonado, Ismael; Cattan, Pedro E; Apt, Werner; Ferreira, Arturo

    2017-02-08

    Triatoma infestans is an important hematophagous vector of Chagas disease, a neglected chronic illness affecting approximately 6 million people in Latin America. Hematophagous insects possess several molecules in their saliva that counteract host defensive responses. Calreticulin (CRT), a multifunctional protein secreted in saliva, contributes to the feeding process in some insects. Human CRT (HuCRT) and Trypanosoma cruzi CRT (TcCRT) inhibit the classical pathway of complement activation, mainly by interacting through their central S domain with complement component C1. In previous studies, we have detected CRT in salivary gland extracts from T. infestans We have called this molecule TiCRT. Given that the S domain is responsible for C1 binding, we have tested its role in the classical pathway of complement activation in vertebrate blood. We have cloned and characterized the complete nucleotide sequence of CRT from T. infestans , and expressed its S domain. As expected, this S domain binds to human C1 and, as a consequence, it inhibits the classical pathway of complement, at its earliest stage of activation, namely the generation of C4b. Possibly, the presence of TiCRT in the salivary gland represents an evolutionary adaptation in hematophagous insects to control a potential activation of complement proteins, present in the massive blood meal that they ingest, with deleterious consequences at least on the anterior digestive tract of these insects. © The American Society of Tropical Medicine and Hygiene.

  5. A zebrafish model for uremic toxicity: role of the complement pathway.

    Science.gov (United States)

    Berman, Nathaniel; Lectura, Melisa; Thurman, Josh; Reinecke, James; Raff, Amanda C; Melamed, Michal L; Reinecke, James; Quan, Zhe; Evans, Todd; Meyer, Timothy W; Hostetter, Thomas H

    2013-01-01

    Many organic solutes accumulate in end-stage renal disease (ESRD) and some are poorly removed with urea-based prescriptions for hemodialysis. However, their toxicities have been difficult to assess. We have employed an animal model, the zebrafish embryo, to test the toxicity of uremic serum compared to control. Serum was obtained from stable ESRD patients predialysis or from normal subjects. Zebrafish embryos 24 h postfertilization were exposed to experimental media at a water:human serum ratio of 3:1. Those exposed to serum from uremic subjects had significantly reduced survival at 8 h (19 ± 18 vs. 94 ± 6%, p 50 kDa, respectively). Heating serum abrogated its toxicity. EDTA, a potent inhibitor of complement by virtue of calcium chelation, reduced the toxicity of uremic serum compared to untreated uremic serum (96 ± 5 vs. 28 ± 20% survival, p < 0.016, chelated vs. nonchelated serum, respectively). Anti-factor B, a specific inhibitor of the alternative complement pathway, reduced the toxicity of uremic serum, compared to untreated uremic serum (98 ± 6 vs. 3 ± 9% survival, p < 0.016, anti-factor B treated vs. nontreated, respectively). Uremic serum is thus more toxic to zebrafish embryos than normal serum. Furthermore, this toxicity is associated with a fraction of large size, is inactivated by heat, and is reduced by both specific and nonspecific inhibitors of complement activation. Together these data lend support to the hypothesis that at least some uremic toxicities may be mediated by complement. Copyright © 2013 S. Karger AG, Basel.

  6. Genotoxicity test of irradiated foods

    International Nuclear Information System (INIS)

    Tanaka, Noriho

    2004-01-01

    Safety tests of radiation irradiated foods started as early as from 1967 in Japan and genotoxicity tests in the Hatano Res. Inst., from 1977. The latter is unique in the world and is reviewed in this paper. Tests included those for the initial injury of DNA, mutagenicity, chromosomal aberration and transformation with use of bacteria, cultured mammalian cells and animals (for chromosomal aberration, micronucleus formation and dominant lethality). Foods tested hitherto were onion, rice, wheat and flour, Vienna sausage, fish sausage (kamaboko), mandarian orange, potato, black pepper and red capsicum, of which extract or powder was subjected to the test. Irradiation doses and its purposes were 0.15-6 kGy γ-ray ( 60 Co) or electron beam by the accelerator (only for the orange), and suppression of germination, pesticide action or sterilization, respectively. Genotoxicity of all foods under tested conditions is shown negative. (N.I.)

  7. M. leprae components induce nerve damage by complement activation: identification of lipoarabinomannan as the dominant complement activator.

    Science.gov (United States)

    Bahia El Idrissi, Nawal; Das, Pranab K; Fluiter, Kees; Rosa, Patricia S; Vreijling, Jeroen; Troost, Dirk; Morgan, B Paul; Baas, Frank; Ramaglia, Valeria

    2015-05-01

    Peripheral nerve damage is the hallmark of leprosy pathology but its etiology is unclear. We previously identified the membrane attack complex (MAC) of the complement system as a key determinant of post-traumatic nerve damage and demonstrated that its inhibition is neuroprotective. Here, we determined the contribution of the MAC to nerve damage caused by Mycobacterium leprae and its components in mouse. Furthermore, we studied the association between MAC and the key M. leprae component lipoarabinomannan (LAM) in nerve biopsies of leprosy patients. Intraneural injections of M. leprae sonicate induced MAC deposition and pathological changes in the mouse nerve, whereas MAC inhibition preserved myelin and axons. Complement activation occurred mainly via the lectin pathway and the principal activator was LAM. In leprosy nerves, the extent of LAM and MAC immunoreactivity was robust and significantly higher in multibacillary compared to paucibacillary donors (p = 0.01 and p = 0.001, respectively), with a highly significant association between LAM and MAC in the diseased samples (r = 0.9601, p = 0.0001). Further, MAC co-localized with LAM on axons, pointing to a role for this M. leprae antigen in complement activation and nerve damage in leprosy. Our findings demonstrate that MAC contributes to nerve damage in a model of M. leprae-induced nerve injury and its inhibition is neuroprotective. In addition, our data identified LAM as the key pathogen associated molecule that activates complement and causes nerve damage. Taken together our data imply an important role of complement in nerve damage in leprosy and may inform the development of novel therapeutics for patients.

  8. Hepatitis C virus NS3/4A protease inhibits complement activation by cleaving complement component 4.

    Directory of Open Access Journals (Sweden)

    Seiichi Mawatari

    Full Text Available BACKGROUND: It has been hypothesized that persistent hepatitis C virus (HCV infection is mediated in part by viral proteins that abrogate the host immune response, including the complement system, but the precise mechanisms are not well understood. We investigated whether HCV proteins are involved in the fragmentation of complement component 4 (C4, composed of subunits C4α, C4β, and C4γ, and the role of HCV proteins in complement activation. METHODS: Human C4 was incubated with HCV nonstructural (NS 3/4A protease, core, or NS5. Samples were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and then subjected to peptide sequencing. The activity of the classical complement pathway was examined using an erythrocyte hemolysis assay. The cleavage pattern of C4 in NS3/4A-expressing and HCV-infected cells, respectively, was also examined. RESULTS: HCV NS3/4A protease cleaved C4γ in a concentration-dependent manner, but viral core and NS5 did not. A specific inhibitor of NS3/4A protease reduced C4γ cleavage. NS3/4A protease-mediated cleavage of C4 inhibited classical pathway activation, which was abrogated by a NS3/4A protease inhibitor. In addition, co-transfection of cells with C4 and wild-type NS3/4A, but not a catalytic-site mutant of NS3/4A, produced cleaved C4γ fragments. Such C4 processing, with a concomitant reduction in levels of full-length C4γ, was also observed in HCV-infected cells expressing C4. CONCLUSIONS: C4 is a novel cellular substrate of the HCV NS3/4A protease. Understanding disturbances in the complement system mediated by NS3/4A protease may provide new insights into the mechanisms underlying persistent HCV infection.

  9. Sodium polyanethole sulfonate as an inhibitor of activation of complement function in blood culture systems

    DEFF Research Database (Denmark)

    Palarasah, Yaseelan; Skjoedt, Mikkel-Ole; Vitved, Lars

    2010-01-01

    complement activation pathways: the classical, alternative, and lectin pathways, respectively. Inhibition of complement activity by SPS is caused by a blocking of complement activation and is not a result of complement consumption. The classical pathway is inhibited at SPS concentrations greater than 0.1 mg...... findings also open up the possibility of a new assay for the assessment of the functional capacity of the lectin complement pathway....

  10. Complement inhibitors for age-related macular degeneration.

    Science.gov (United States)

    Williams, Michael A; McKay, Gareth J; Chakravarthy, Usha

    2014-01-15

    Given the relatively high prevalence of age-related macular degeneration (AMD) and the increased incidence of AMD as populations age, the results of trials of novel treatments are awaited with much anticipation. The complement cascade describes a series of proteolytic reactions occurring throughout the body that generate proteins with a variety of roles including the initiation and promotion of immune reactions against foreign materials or micro-organisms. The complement cascade is normally tightly regulated, but much evidence implicates complement overactivity in AMD and so it is a logical therapeutic target in the treatment of AMD. To assess the effects and safety of complement inhibitors in the prevention or treatment of advanced AMD. We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2013, Issue 11), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to November 2013), EMBASE (January 1980 to November 2013), Allied and Complementary Medicine Database (AMED) (January 1985 to November 2013), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to November 2013), OpenGrey (System for Information on Grey Literature in Europe) (www.opengrey.eu/), Web of Science Conference Proceedings Citation Index - Science (CPCI-S) (January 1990 to November 2013), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 21 November 2013. We also performed handsearching of proceedings, from 2012 onwards, of meetings and conferences of specific professional organisations. We planned to include randomised controlled trials (RCTs) with

  11. Guinea pig complement potently measures vibriocidal activity of human antibodies in response to cholera vaccines.

    Science.gov (United States)

    Kim, Kyoung Whun; Jeong, Soyoung; Ahn, Ki Bum; Yang, Jae Seung; Yun, Cheol-Heui; Han, Seung Hyun

    2017-12-01

    The vibriocidal assay using guinea pig complement is widely used for the evaluation of immune responses to cholera vaccines in human clinical trials. However, it is unclear why guinea pig complement has been used over human complement in the measurement of vibriocidal activity of human sera and there have not been comparison studies for the use of guinea pig complement over those from other species. Therefore, we comparatively investigated the effects of complements derived from human, guinea pig, rabbit, and sheep on vibriocidal activity. Complements from guinea pig, rabbit, and human showed concentration-dependent vibriocidal activity in the presence of quality control serum antibodies. Of these complements, guinea pig complement was the most sensitive and effective over a wide concentration range. When the vibriocidal activity of complements was measured in the absence of serum antibodies, human, sheep, and guinea pig complements showed vibriocidal activity up to 40-fold, 20-fold, and 1-fold dilution, respectively. For human pre- and post-vaccination sera, the most potent vibriocidal activity was observed when guinea pig complement was used. In addition, the highest fold-increases between pre- and post- vaccinated sera were obtained with guinea pig complement. Furthermore, human complement contained a higher amount of V. cholerae- and its lipopolysaccharide-specific antibodies than guinea pig complement. Collectively, these results suggest that guinea pig complements are suitable for vibriocidal assays due to their high sensitivity and effectiveness to human sera.

  12. Complements and the Wound Healing Cascade: An Updated Review

    Directory of Open Access Journals (Sweden)

    Hani Sinno

    2013-01-01

    Full Text Available Wound healing is a complex pathway of regulated reactions and cellular infiltrates. The mechanisms at play have been thoroughly studied but there is much still to learn. The health care system in the USA alone spends on average 9 billion dollars annually on treating of wounds. To help reduce patient morbidity and mortality related to abnormal or prolonged skin healing, an updated review and understanding of wound healing is essential. Recent works have helped shape the multistep process in wound healing and introduced various growth factors that can augment this process. The complement cascade has been shown to have a role in inflammation and has only recently been shown to augment wound healing. In this review, we have outlined the biology of wound healing and discussed the use of growth factors and the role of complements in this intricate pathway.

  13. Therapeutic inhibition of the complement system. Y2K update.

    Science.gov (United States)

    Asghar, S S; Pasch, M C

    2000-09-01

    Activation of complement is an essential part of the mechanism of pathogenesis of a large number of human diseases; its inhibition by pharmacological means is likely to suppress disease processes in complement mediated diseases. From this point of view low molecular weight synthetic inhibitors of complement are being developed and high molecular weight natural inhibitors of human origin present in plasma or embedded in cell membrane are being purified or produced in their recombinant forms. This review is concerned with high molecular weight inhibitors, some of which are already in clinical use but may be efficacious in many other diseases in which they have not yet been tried. C1-esterase inhibitor (C1-INH) concentrate prepared from human plasma is being successfully used for the treatment of hereditary angioneurotic edema. Recently, C1-INH has been found to be consumed in severe inflammation and has been shown to exert beneficial effects in several inflammatory conditions such as human sepsis, post-operative myocardial dysfunction due to reperfusion injury, severe capillary leakage syndrome after bone marrow transplantation, reperfusion injury after lung transplantation, burn, and cytotoxicity caused by IL-2 therapy in cancer. Factor I has been used for the treatment of factor I deficiency. Recombinant soluble forms of membrane cofactor protein (MCP), and decay accelerating factor (DAF) have not yet been tried in humans but have been shown to be effective in immune complex mediate inflammation in animals. Organs of pigs transgenic for one or more of human membrane regulators of complement namely membrane cofactor protein (MCP), decay accelerating factor (DAF) or CD59, are being produced for transplantation into humans. They have been shown to be resistant to hyperacute rejection in non-human primates; acute vascular rejection is still a problem in their clinical use. It is hoped that these observations together with future developments will make xeno

  14. Complementation in spaces of continuous functions on compact lines

    Czech Academy of Sciences Publication Activity Database

    Kalenda, O.F.K.; Kubiś, Wieslaw

    2012-01-01

    Roč. 386, č. 1 (2012), s. 241-257 ISSN 0022-247X R&D Projects: GA AV ČR IAA100190901 Institutional research plan: CEZ:AV0Z10190503 Keywords : compact linearly ordered space * averagign operator * continuous separable complementation property * projectional skeleton Subject RIV: BA - General Mathematics Impact factor: 1.050, year: 2012 http://www.sciencedirect.com/science/article/pii/S0022247X11007128

  15. Almost disjoint families of countable sets and separable complementation properties

    Czech Academy of Sciences Publication Activity Database

    Ferrer, J.; Koszmider, P.; Kubiś, Wieslaw

    2013-01-01

    Roč. 401, č. 2 (2013), s. 939-949 ISSN 0022-247X R&D Projects: GA ČR(CZ) GAP201/12/0290 Institutional support: RVO:67985840 Keywords : almost disjoint family * separable complementation property Subject RIV: BA - General Mathematics Impact factor: 1.119, year: 2013 http://www.sciencedirect.com/science/article/pii/S0022247X13000139

  16. Non-kinetic capabilities: complementing the kinetic prevalence to targeting

    OpenAIRE

    Ducheine, P.

    2014-01-01

    Targeting is used in military doctrine to describe a military operational way, using (military) means to influence a target (or addressee) in order to achieve designated political and/or military goals. The four factors italicized are used to analyse non-kinetic targeting, complementing our knowledge and understanding of the kinetic prevalence. Paradoxically, non-kinetic targeting is not recognized as a separate concept: kinetic and non-kinetic are intertwined facets of targeting. Kinetic tar...

  17. Tobacco and alcohol: complements or substitutes? ; a structural model approach

    OpenAIRE

    Tauchmann, Harald; Göhlmann, Silja; Requate, Till; Schmidt, Christoph M.

    2008-01-01

    The question of whether two drugs – namely alcohol and tobacco – are used as complements or substitutes is of crucial interest if side-effects of anti-smoking policies are considered. Numerous papers have empirically addressed this issue by estimating demand systems for alcohol and tobacco and subsequently calculating cross-price effects. However, this traditional approach often is seriously hampered by insufficient price-variation observed in survey data. We therefore suggest an alternative ...

  18. Complement pathway biomarkers and age-related macular degeneration

    Science.gov (United States)

    Gemenetzi, M; Lotery, A J

    2016-01-01

    In the age-related macular degeneration (AMD) ‘inflammation model', local inflammation plus complement activation contributes to the pathogenesis and progression of the disease. Multiple genetic associations have now been established correlating the risk of development or progression of AMD. Stratifying patients by their AMD genetic profile may facilitate future AMD therapeutic trials resulting in meaningful clinical trial end points with smaller sample sizes and study duration. PMID:26493033

  19. Complement-dependent transport of antigen into B cell follicles

    DEFF Research Database (Denmark)

    Gonzalez, Santiago F.; Lukacs-Kornek, Veronika; Kuligowski, Michael P.

    2010-01-01

    an additional novel pathway in which complement C3 and its receptors enhance humoral immunity through delivery of Ag to the B cell compartment. In this review, we discuss this pathway and highlight several novel exceptions recently found with a model influenza vaccine, such as mannose-binding lectin...... opsonization of influenza and uptake by macrophages, and the capture of virus by dendritic cells residing in the medullary compartment of peripheral lymph nodes....

  20. Early Intra-Articular Complement Activation in Ankle Fractures

    Directory of Open Access Journals (Sweden)

    Hagen Schmal

    2014-01-01

    Full Text Available Cytokine regulation possibly influences long term outcome following ankle fractures, but little is known about synovial fracture biochemistry. Eight patients with an ankle dislocation fracture were included in a prospective case series and matched with patients suffering from grade 2 osteochondritis dissecans (OCD of the ankle. All fractures needed external fixation during which joint effusions were collected. Fluid analysis was done by ELISA measuring aggrecan, bFGF, IL-1β, IGF-1, and the complement components C3a, C5a, and C5b-9. The time periods between occurrence of fracture and collection of effusion were only significantly associated with synovial aggrecan and C5b-9 levels (P<0.001. Furthermore, synovial expressions of both proteins correlated with each other (P<0.001. Although IL-1β expression was relatively low, intra-articular levels correlated with C5a (P<0.01 and serological C-reactive protein concentrations 2 days after surgery (P<0.05. Joint effusions were initially dominated by neutrophils, but the portion of monocytes constantly increased reaching 50% at day 6 after fracture (P<0.02. Whereas aggrecan and IL-1β concentrations were not different in fracture and OCD patients, bFGF, IGF-1, and all complement components were significantly higher concentrated in ankle joints with fractures (P<0.01. Complement activation and inflammatory cell infiltration characterize the joint biology following acute ankle fractures.

  1. Structural Basis for Eculizumab-Mediated Inhibition of the Complement Terminal Pathway

    DEFF Research Database (Denmark)

    Schatz-Jakobsen, Janus Asbjørn; zhang, yuchun; Johnson, Krista

    2016-01-01

    the structural observations of the interaction are supported by the reduced ability of a subset of these mutated antibodies to inhibit MAC formation as tested in a hemolysis assay. Our results suggest that eculizumab functions by sterically preventing C5 from binding to convertases and explain the exquisite......Eculizumab is a humanized monoclonal antibody approved for treatment of patients with paroxysmal nocturnal hemoglobinuria (PNH) and atypical hemolytic uraemic syndrome. Eculizumab binds complement component C5 and prevents its cleavage by C5 convertases, inhibiting release of both...

  2. Complement-dependent pathogenicity of brain-specific antibodies in cerebrospinal fluid

    DEFF Research Database (Denmark)

    Asgari, Nasrin; Khorooshi, Reza; Lillevang, Søren T

    2013-01-01

    The specificity and potential pathogenicity of autoantibodies vary between neurological diseases. It is often unclear whether their detection in cerebrospinal fluid (CSF) is a consequence or a cause of pathology. The goal was to test whether administration of brain-specific antibodies into CSF...... would be sufficient for pathology. Purified immunoglobulin G from a neuromyelitis optica patient was injected intrathecally with complement to naive mice. Histopathological analysis at 7 days revealed damage to the ependyma, disruption of the CSF parenchymal barrier and pathologic lesions, distant from...

  3. Complement inhibitory proteins expression in placentas of thrombophilic women Complement inhibitory proteins expression in placentas of thrombophilic women

    Directory of Open Access Journals (Sweden)

    Przemysław Krzysztof Wirstlein

    2012-10-01

    Full Text Available Factors controlling complement activation appear to exert a protective effect on pregnancy. This is
    particularly important in women with thrombophilia. The aim of this study was to determine the transcript and
    protein levels of complement decay-accelerating factor (DAF and membrane cofactor protein (MCP in the
    placentas of women with acquired and inherited thrombophilia. Also, we assessed immunohistochemistry staining
    of inhibitors of the complement cascade, DAF and MCP proteins, in the placentas of thrombophilic women.
    Placentas were collected from eight women with inherited thrombophilia and ten with acquired thrombophilia.
    The levels of DAF and MCP transcripts were evaluated by qPCR, the protein level was evaluated by Western
    blot. We observed a higher transcript (p < 0.05 and protein (p < 0.001 levels of DAF and MCP in the placentas
    of thrombophilic women than in the control group. DAF and MCP were localized on villous syncytiotrophoblast
    membranes, but the assessment of staining in all groups did not differ. The observed higher expression level of
    proteins that control activation of complement control proteins is only seemingly contradictory to the changes
    observed for example in the antiphospholipid syndrome. However, given the hitherto known biochemical changes
    associated with thrombophilia, a mechanism in which increased expression of DAF and MCP in the placentas is
    an effect of proinflammatory cytokines, which accompanies thrombophilia, is probable.Factors controlling complement activation appear to exert a protective effect on pregnancy. This is
    particularly important in women with thrombophilia. The aim of this study was to determine the transcript and
    protein levels of complement decay-accelerating factor (DAF and membrane cofactor protein (MCP in the
    placentas of women with acquired and inherited thrombophilia. Also, we assessed immunohistochemistry

  4. A potent complement factor C3 specific nanobody inhibiting multiple functions in the alternative pathway of human and murine complement

    DEFF Research Database (Denmark)

    Jensen, Rasmus K; Pihl, Rasmus; Gadeberg, Trine A F

    2018-01-01

    The complement system is a complex, carefully regulated proteolytic cascade for which suppression of aberrant activation is of increasing clinical relevance and inhibition of the complement alternative pathway is a subject of intense research. Here, we describe the nanobody hC3Nb1 that binds...... to multiple functional states of C3 with sub-nanomolar affinity. The nanobody causes a complete shutdown of alternative pathway activity in human and murine serum when present in concentrations comparable to C3, and hC3Nb1 is shown to prevent both proconvertase assembly as well as binding of the C3 substrate...... to C3 convertases. Our crystal structure of the C3b-hC3Nb1 complex and functional experiments demonstrate that proconvertase formation is blocked by steric hindrance between the nanobody and an Asn-linked glycan on complement factor B. In addition, hC3Nb1 is shown to prevent factor H binding to C3b...

  5. Yersinia enterocolitica serum resistance proteins YadA and ail bind the complement regulator C4b-binding protein.

    Directory of Open Access Journals (Sweden)

    Vesa Kirjavainen

    Full Text Available Many pathogens are equipped with factors providing resistance against the bactericidal action of complement. Yersinia enterocolitica, a Gram-negative enteric pathogen with invasive properties, efficiently resists the deleterious action of human complement. The major Y. enterocolitica serum resistance determinants include outer membrane proteins YadA and Ail. Lipopolysaccharide (LPS O-antigen (O-ag and outer core (OC do not contribute directly to complement resistance. The aim of this study was to analyze a possible mechanism whereby Y. enterocolitica could inhibit the antibody-mediated classical pathway of complement activation. We show that Y. enterocolitica serotypes O:3, O:8, and O:9 bind C4b-binding protein (C4bp, an inhibitor of both the classical and lectin pathways of complement. To identify the C4bp receptors on Y. enterocolitica serotype O:3 surface, a set of mutants expressing YadA, Ail, O-ag, and OC in different combinations was tested for the ability to bind C4bp. The studies showed that both YadA and Ail acted as C4bp receptors. Ail-mediated C4bp binding, however, was blocked by the O-ag and OC, and could be observed only with mutants lacking these LPS structures. C4bp bound to Y. enterocolitica was functionally active and participated in the factor I-mediated degradation of C4b. These findings show that Y. enterocolitica uses two proteins, YadA and Ail, to bind C4bp. Binding of C4bp could help Y. enterocolitica to evade complement-mediated clearance in the human host.

  6. Multiple activities of LigB potentiate virulence of Leptospira interrogans: inhibition of alternative and classical pathways of complement.

    Directory of Open Access Journals (Sweden)

    Henry A Choy

    Full Text Available Microbial pathogens acquire the immediate imperative to avoid or counteract the formidable defense of innate immunity as soon as they overcome the initial physical barriers of the host. Many have adopted the strategy of directly disrupting the complement system through the capture of its components, using proteins on the pathogen's surface. In leptospirosis, pathogenic Leptospira spp. are resistant to complement-mediated killing, in contrast to the highly vulnerable non-pathogenic strains. Pathogenic L. interrogans uses LenA/LfhA and LcpA to respectively sequester and commandeer the function of two regulators, factor H and C4BP, which in turn bind C3b or C4b to interrupt the alternative or classical pathways of complement activation. LigB, another surface-proximal protein originally characterized as an adhesin binding multiple host proteins, has other activities suggesting its importance early in infection, including binding extracellular matrix, plasma, and cutaneous repair proteins and inhibiting hemostasis. In this study, we used a recent model of ectopic expression of LigB in the saprophyte, L. biflexa, to test the hypothesis that LigB also interacts with complement proteins C3b and C4b to promote the virulence of L. interrogans. The surface expression of LigB partially rescued the non-pathogen from killing by 5% normal human serum, showing 1.3- to 48-fold greater survival 4 to 6 d following exposure to complement than cultures of the non-expressing parental strain. Recombinant LigB7'-12 comprising the LigB-specific immunoglobulin repeats binds directly to human complement proteins, C3b and C4b, with respective K(ds of 43±26 nM and 69±18 nM. Repeats 9 to 11, previously shown to contain the binding domain for fibronectin and fibrinogen, are also important in LigB-complement interactions, which interfere with the alternative and classical pathways measured by complement-mediated hemolysis of erythrocytes. Thus, LigB is an adaptable interface

  7. Genotoxic evaluation of [DOTA,Tyr3]octreotate labeled with 131I and 177Lu in human peripheral lymphocytes in vitro by micronucleus assay

    International Nuclear Information System (INIS)

    Suzauki, Miriam Fussae; Silva, Marcia Augusta da; Caldeira Filho, Jose de Souza; Colturato, Maria Tereza; Araujo, Elaine Bortoleti de; Bartolini, Paolo; Okazaki, Kayo

    2005-01-01

    The radiolabeled receptor-binding peptides have being used for cancer diagnosis and therapy. The octreotate, a somatostatin analogue peptide, bound to various tumors expressing sst receptors (thyroid, pancreas, prostrate, melanoma and lymphomas). The amount and the type of receptors for somatostatin influence the tissue uptake. The [DOTA, Tyr 3 ]octreotate has been used because of its high affinity to somatostatin subtype receptors sstr 2 and sstr 5 . The pharmacokinetic study showed that the blood clearance is rapid and only 9% of the intravenous injected activity remains in human blood after one hour. The aim of this study was to evaluate the cytogenetic effect of radiolabeled [DOTA, Tyr 3 ]octreotate in blood cells in vitro, using the cytokinesis-block micronucleus (MN) assay. This technique allows evaluating the mutagenic effects of both endogenous and exogenous agents at chromosome level. Blood samples of healthy donors were collected in heparinized syringes and exposed to different activities of [DOTA, Tyr 3 ]octreotate labeled with with 131 I (n=3) and 177 Lu (n=3), where radioactive concentration ranged from 600 to 5600 kBq/mL, corresponding to an injected activity of 3.1 to 28.9 GBq in a reference man of 70 kg weight. 131 I and 177 Lu are beta- and gamma-emitters. After one-hour exposition to radiopharmaceuticals at 37 deg C, the cells were washed with culture medium for removing the non internalised octreotate and cultivated for 72 hours, according to criteria adopted by the IAEA. The results showed a positive correlation between radioactive concentrations (X) and the frequency of binucleated cells with micronuclei (Y) (P 131 I-DOTA, Tyr 3 ]octreotate was Y = (1.634 ± 0.236) + (0.912 ± 0.137) 10 -3 X and for [ 177 Lu-DOTA, Tyr 3 ]octreotate was Y = (1.715 ± 0.342) + (0.743 ± 0.135) 10 -3 X. The non labeled molecule, [DOTA, Tyr 3 ]octreotate, has no influence in the induction of cytogenetic damage. The micronucleus assay with rat pancreatic tumor cells

  8. Complement activation, endothelial dysfunction, insulin resistance and chronic heart failure

    DEFF Research Database (Denmark)

    Bjerre, M.; Kistorp, C.; Hansen, T.K.

    2010-01-01

    Objectives. Patients with chronic heart failure (CHF) have an exaggerated immune response, endothelial damage/dysfunction, and increased risk of diabetes mellitus (DM). The inter-relationship(s) between indices of complement activation (soluble membrane attack complex, sMAC), inflammation (hs...... to ischemic heart disease (IHD) as compared with CHF patients with non-ischemic ethiology (p = 0.02), but were not predictive of survival or progression of CHF. A moderate strong relation between sMAC and sEsel levels was found beta = 0.33 (p ... damaging of the heart tissue...

  9. Malaria parasite evasion of classical complement pathway attack

    DEFF Research Database (Denmark)

    Larsen, Mads Delbo; Ditlev, Sisse; Olmos, Rafael Bayarri

    2017-01-01

    of the protective antibodies that are gradually acquired in response to P. falciparum-IEs. Although this response is dominated by IgG1 and IgG3, complement-mediated attack following activation of the classical pathway does not appear to be a major effector mechanism. We hypothesized that this is related to the knob...... is that the knob-restricted expression of PfEMP1 on the IE surface may serve as a hitherto unappreciated immune evasion mechanism employed by P. falciparum parasites....

  10. Structural and functional characterization of human complement factor P

    DEFF Research Database (Denmark)

    Pedersen, Dennis

    not yet been resolved. This PhD-thesis provide structural understanding of the FP mediated stabilization of the AP C3 convertase. Furthermore, functional studies involving oligomeric and monomeric FP variants have helped us to understand the importance of FP oligomerization for the primary functions of FP...... of complement by stabilizing the C3 convertase complex (C3bBb). FP has also been suggested to serve as a pattern recognition molecule for the initiation of the alternative pathway. However, the molecular mechanisms of FP remain unclear due to its oligomeric nature and hence the atomic structure of FP has...

  11. A seventh complementation group in excision-deficient xeroderma pigmentosum

    International Nuclear Information System (INIS)

    Keijzer, W.; Jaspers, N.G.J.; Bootsma, D.; Abrahams, P.J.; Taylor, A.M.R.; Arlett, C.F.; Zelle, B.; Kinmont, P.D.S.

    1979-01-01

    Cells from a xeroderma pigmentosum patient XP2B1 who has reached 17 years of age with no keratoses or skin tumours constitute a new, 7th complementation group G. These cells exhibit a low residual level of excision repair, 2% of normal after a UV dose of 5 J/m 2 and an impairment of post-replication repair characteristic of excision-defective XPs. They are also sensitive to the lethal effects of UV and defective in host-cell reactivation of UV-irradiated SV40 DNA. (Auth.)

  12. Approximate Schur complement preconditioning of the lowest order nodal discretizations

    Energy Technology Data Exchange (ETDEWEB)

    Moulton, J.D.; Ascher, U.M. [Univ. of British Columbia, Vancouver, British Columbia (Canada); Morel, J.E. [Los Alamos National Lab., NM (United States)

    1996-12-31

    Particular classes of nodal methods and mixed hybrid finite element methods lead to equivalent, robust and accurate discretizations of 2nd order elliptic PDEs. However, widespread popularity of these discretizations has been hindered by the awkward linear systems which result. The present work exploits this awkwardness, which provides a natural partitioning of the linear system, by defining two optimal preconditioners based on approximate Schur complements. Central to the optimal performance of these preconditioners is their sparsity structure which is compatible with Dendy`s black box multigrid code.

  13. Identification and functional characterisation of Complement Regulator Acquiring Surface Protein-1 of serum resistant Borrelia garinii OspA serotype 4

    Directory of Open Access Journals (Sweden)

    Zipfel Peter F

    2010-02-01

    Full Text Available Abstract Background B. burgdorferi sensu lato (sl is the etiological agent of Lyme borreliosis in humans. Spirochetes have adapted themselves to the human immune system in many distinct ways. One important immune escape mechanism for evading complement activation is the binding of complement regulators Factor H (CFH or Factor H-like protein1 (FHL-1 to Complement Regulator-Acquiring Surface Proteins (CRASPs. Results We demonstrate that B. garinii OspA serotype 4 (ST4 PBi resist complement-mediated killing by binding of FHL-1. To identify the primary ligands of FHL-1 four CspA orthologs from B. garinii ST4 PBi were cloned and tested for binding to human CFH and FHL-1. Orthologs BGA66 and BGA71 were found to be able to bind both complement regulators but with different intensities. In addition, all CspA orthologs were tested for binding to mammalian and avian CFH. Distinct orthologs were able to bind to CFH of different animal origins. Conclusions B. garinii ST4 PBi is able to evade complement killing and it can bind FHL-1 to membrane expressed proteins. Recombinant proteins BGA66 can bind FHL-1 and human CFH, while BGA71 can bind only FHL-1. All recombinant CspA orthologs from B. garinii ST4 PBi can bind CFH from different animal origins. This partly explains the wide variety of animals that can be infected by B. garinii.

  14. A new location to split Cre recombinase for protein fragment complementation.

    Science.gov (United States)

    Rajaee, Maryam; Ow, David W

    2017-11-01

    We have previously described a recombinase-mediated gene stacking system in which the Cre recombinase is used to remove lox-site flanked DNA no longer needed after each round of Bxb1 integrase-mediated site-specific integration. The Cre recombinase can be conveniently introduced by hybridization with a cre-expressing plant. However, maintaining an efficient cre-expressing line over many generations can be a problem, as high production of this DNA-binding protein might interfere with normal chromosome activities. To counter this selection against high Cre activity, we considered a split-cre approach, in which Cre activity is reconstituted after separate parts of Cre are brought into the same genome by hybridization. To insure that the recombinase-mediated gene stacking system retains its freedom to operate, we tested for new locations to split Cre into complementing fragments. In this study, we describe testing four new locations for splitting the Cre recombinase for protein fragment complementation and show that the two fragments of Cre split between Lys244 and Asn245 can reconstitute activity that is comparable to that of wild-type Cre. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  15. Complement Factor H as a potential atherogenic marker in chronic Chagas disease.

    Science.gov (United States)

    Lidani, Kárita Cláudia Freitas; Sandri, Thaisa Lucas; Andrade, Fabiana Antunes; Bavia, Lorena; Nisihara, Renato; Reason, Iara J Messias

    2018-05-19

    We aimed to investigate the association between plasma levels of complement Factor H (FH) with cardiac involvement, inflammatory and cardiometabolic parameters in patients with chronic Chagas disease (CD). FH plasmatic levels were determined in 80 chronic CD patients. Glycemic index, lipidogram (high-density lipoprotein cholesterol HDL-C, low-density lipoprotein cholesterol LDL-C, triglycerides and total cholesterol), and Ultrasensitive C-Reactive Protein (uCRP) values were obtained from medical records. Height, weight, body mass index (BMI) blood pressure and left ventricular ejection fraction (LVEF) were obtained from echocardiography exams. Comparisons between chronic CD clinical forms were performed using Mann-Whitney test and correlation Spearman test. FH levels were correlated positively with triglycerides (p=0.001, r=0.39), LDL-C (p=0.009, r=0.3), cholesterol (p=0.02, r=0.28), uCRP (p=0.029, r=0.31) and BMI (p=0.008, r=0.34); and negatively with HDL-C (p=0.03, r=-0.25) levels. Dyslipidemic patients showed higher FH levels compared to normolipidemic, although no difference for FH levels were observed between chronic CD clinical forms. Alternative pathway of complement may be a link between immune response and metabolic disorders, with important immunoregulatory role in chronic CD. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  16. Complement-Mediated Enhancement of Monocyte Adhesion to Endothelial Cells by HLA Antibodies, and Blockade by a Specific Inhibitor of the Classical Complement Cascade, TNT003

    Science.gov (United States)

    Valenzuela, Nicole M.; Thomas, Kimberly A.; Mulder, Arend; Parry, Graham C.; Panicker, Sandip; Reed, Elaine F.

    2017-01-01

    Background Antibody-mediated rejection (AMR) of most solid organs is characterized by evidence of complement activation and/or intragraft macrophages (C4d + and CD68+ biopsies). We previously demonstrated that crosslinking of HLA I by antibodies triggered endothelial activation and monocyte adhesion. We hypothesized that activation of the classical complement pathway at the endothelial cell surface by HLA antibodies would enhance monocyte adhesion through soluble split product generation, in parallel with direct endothelial activation downstream of HLA signaling. Methods Primary human aortic endothelial cells (HAEC) were stimulated with HLA class I antibodies in the presence of intact human serum complement. C3a and C5a generation, endothelial P-selectin expression, and adhesion of human primary and immortalized monocytes (Mono Mac 6) were measured. Alternatively, HAEC or monocytes were directly stimulated with purified C3a or C5a. Classical complement activation was inhibited by pretreatment of complement with an anti-C1s antibody (TNT003). Results Treatment of HAEC with HLA antibody and human complement increased the formation of C3a and C5a. Monocyte recruitment by human HLA antibodies was enhanced in the presence of intact human serum complement or purified C3a or C5a. Specific inhibition of the classical complement pathway using TNT003 or C1q-depleted serum significantly reduced adhesion of monocytes in the presence of human complement. Conclusions Despite persistent endothelial viability in the presence of HLA antibodies and complement, upstream complement anaphylatoxin production exacerbates endothelial exocytosis and leukocyte recruitment. Upstream inhibition of classical complement may be therapeutic to dampen mononuclear cell recruitment and endothelial activation characteristic of microvascular inflammation during AMR. PMID:28640789

  17. The Emerging Role of Complement Lectin Pathway in Trypanosomatids: Molecular Bases in Activation, Genetic Deficiencies, Susceptibility to Infection, and Complement System-Based Therapeutics

    Directory of Open Access Journals (Sweden)

    Ingrid Evans-Osses

    2013-01-01

    Full Text Available The innate immune system is evolutionary and ancient and is the pivotal line of the host defense system to protect against invading pathogens and abnormal self-derived components. Cellular and molecular components are involved in recognition and effector mechanisms for a successful innate immune response. The complement lectin pathway (CLP was discovered in 1990. These new components at the complement world are very efficient. Mannan-binding lectin (MBL and ficolin not only recognize many molecular patterns of pathogens rapidly to activate complement but also display several strategies to evade innate immunity. Many studies have shown a relation between the deficit of complement factors and susceptibility to infection. The recently discovered CLP was shown to be important in host defense against protozoan microbes. Although the recognition of pathogen-associated molecular patterns by MBL and Ficolins reveal efficient complement activations, an increase in deficiency of complement factors and diversity of parasite strategies of immune evasion demonstrate the unsuccessful effort to control the infection. In the present paper, we will discuss basic aspects of complement activation, the structure of the lectin pathway components, genetic deficiency of complement factors, and new therapeutic opportunities to target the complement system to control infection.

  18. Is complement good, bad, or both? New functions of the complement factors associated with inflammation mechanisms in the central nervous system.

    Science.gov (United States)

    Tahtouh, Muriel; Croq, Françoise; Lefebvre, Christophe; Pestel, Joël

    2009-09-01

    The complement system is well known as an enzyme cascade that helps to defend against infections. Indeed, this ancestral system bridges innate and adaptive immunity. Its implication in diseases of the central nervous system (CNS), has led to an increased number of studies. Complement activation in the CNS has been generally considered to contribute to tissue damage. However, recent studies suggest that complement may be neuroprotective, and can participate in maintenance and repair of the adult brain. Here, we will review this dual role of complement proteins and some of their functional interactions with part of the chemokine and cytokine network associated with the protection of CNS integrity.

  19. Identification of the Fanconi Anemia Complementation Group I Gene, FANCI

    Directory of Open Access Journals (Sweden)

    Josephine C. Dorsman

    2007-01-01

    Full Text Available To identify the gene underlying Fanconi anemia (FA complementation group I we studied informative FA-I families by a genome-wide linkage analysis, which resulted in 4 candidate regions together encompassing 351 genes. Candidates were selected via bioinformatics and data mining on the basis of their resemblance to other FA genes/proteins acting in the FA pathway, such as: degree of evolutionary conservation, presence of nuclear localization signals and pattern of tissue-dependent expression. We found a candidate, KIAA1794 on chromosome 15q25-26, to be mutated in 8 affected individuals previously assigned to complementation group I. Western blots of endogenous FANCI indicated that functionally active KIAA1794 protein is lacking in FA-I individuals. Knock-down of KIAA1794 expression by siRNA in HeLa cells caused excessive chromosomal breakage induced by mitomycin C, a hallmark of FA cells. Furthermore, phenotypic reversion of a patient-derived cell line was associated with a secondary genetic alteration at the KIAA1794 locus. These data add up to two conclusions. First, KIAA1794 is a FA gene. Second, this gene is identical to FANCI, since the patient cell lines found mutated in this study included the reference cell line for group I, EUFA592.

  20. Complement activation in emergency department patients with severe sepsis.

    Science.gov (United States)

    Younger, John G; Bracho, David O; Chung-Esaki, Hangyul M; Lee, Moonseok; Rana, Gurpreet K; Sen, Ananda; Jones, Alan E

    2010-04-01

    This study assessed the extent and mechanism of complement activation in community-acquired sepsis at presentation to the emergency department (ED) and following 24 hours of quantitative resuscitation. A prospective pilot study of patients with severe sepsis and healthy controls was conducted among individuals presenting to a tertiary care ED. Resuscitation, including antibiotics and therapies to normalize central venous and mean arterial pressure (MAP) and central venous oxygenation, was performed on all patients. Serum levels of Factor Bb (alternative pathway), C4d (classical and mannose-binding lectin [MBL] pathway), C3, C3a, and C5a were determined at presentation and 24 hours later among patients. Twenty patients and 10 healthy volunteer controls were enrolled. Compared to volunteers, all proteins measured were abnormally higher among septic patients (C4d 3.5-fold; Factor Bb 6.1-fold; C3 0.8-fold; C3a 11.6-fold; C5a 1.8-fold). Elevations in C5a were most strongly correlated with alternative pathway activation. Surprisingly, a slight but significant inverse relationship between illness severity (by sequential organ failure assessment [SOFA] score) and C5a levels at presentation was noted. Twenty-four hours of structured resuscitation did not, on average, affect any of the mediators studied. Patients with community-acquired sepsis have extensive complement activation, particularly of the alternative pathway, at the time of presentation that was not significantly reversed by 24 hours of aggressive resuscitation.

  1. Phenotypic complementation of genetic immunodeficiency by chronic herpesvirus infection.

    Science.gov (United States)

    MacDuff, Donna A; Reese, Tiffany A; Kimmey, Jacqueline M; Weiss, Leslie A; Song, Christina; Zhang, Xin; Kambal, Amal; Duan, Erning; Carrero, Javier A; Boisson, Bertrand; Laplantine, Emmanuel; Israel, Alain; Picard, Capucine; Colonna, Marco; Edelson, Brian T; Sibley, L David; Stallings, Christina L; Casanova, Jean-Laurent; Iwai, Kazuhiro; Virgin, Herbert W

    2015-01-20

    Variation in the presentation of hereditary immunodeficiencies may be explained by genetic or environmental factors. Patients with mutations in HOIL1 (RBCK1) present with amylopectinosis-associated myopathy with or without hyper-inflammation and immunodeficiency. We report that barrier-raised HOIL-1-deficient mice exhibit amylopectin-like deposits in the myocardium but show minimal signs of hyper-inflammation. However, they show immunodeficiency upon acute infection with Listeria monocytogenes, Toxoplasma gondii or Citrobacter rodentium. Increased susceptibility to Listeria was due to HOIL-1 function in hematopoietic cells and macrophages in production of protective cytokines. In contrast, HOIL-1-deficient mice showed enhanced control of chronic Mycobacterium tuberculosis or murine γ-herpesvirus 68 (MHV68), and these infections conferred a hyper-inflammatory phenotype. Surprisingly, chronic infection with MHV68 complemented the immunodeficiency of HOIL-1, IL-6, Caspase-1 and Caspase-1;Caspase-11-deficient mice following Listeria infection. Thus chronic herpesvirus infection generates signs of auto-inflammation and complements genetic immunodeficiency in mutant mice, highlighting the importance of accounting for the virome in genotype-phenotype studies.

  2. Complement-mediated killing of Borrelia burgdorferi by nonimmune sera from sika deer.

    Science.gov (United States)

    Nelson, D R; Rooney, S; Miller, N J; Mather, T N

    2000-12-01

    Various species of cervid deer are the preferred hosts for adult, black-legged ticks (Ixodes scapularis and Ixodes pacificus) in the United States. Although frequently exposed to the agent of Lyme disease (Borrelia burgdorferi), these animals, for the most part, are incompetent as transmission reservoirs. We examined the borreliacidal activity of normal and B. burgdorferi-immune sera from sika deer (Cervus nippon) maintained in a laboratory setting and compared it to that of similar sera from reservoir-competent mice and rabbits. All normal deer sera (NDS) tested killed > 90% of B. burgdorferi cells. In contrast, normal mouse and rabbit sera killed feeding exhibited IFA titers of 1:256, whereas sera from mice and rabbits similarly exposed had titers of > 1:1,024. Heat treatment (56 C, 30 min) of NDS reduced borreliacidal activity, with complement-mediated killing. The chelators EGTA and EDTA were used to block the classical or both the classical and alternative complement pathways, respectively. Addition of 10 mM EGTA to NDS had a negligible effect on borreliacidal activity, with > 90% of the cells killed. Addition of 10 mM EDTA reduced the killing to approximately 30%, whereas the addition of Mg2+ (10 mM) restored borreliacidal activity to NDS. The addition of zymosan A, an activator of the alternative pathway, increased the survival of B. burgdorferi cells to approximately 80% in NDS. These data suggest that the alternative complement activation pathway plays a major role in the borreliacidal activity of NDS. Additionally, 10 mM EGTA had almost no effect on the killing activity of B. burgdorferi-exposed deer sera, suggesting that the classical pathway is not involved in Borrelia killing, even in sera from B. burgdorferi-exposed deer.

  3. DMPD: Complement-mediated phagocytosis--the role of Syk. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16754322 Complement-mediated phagocytosis--the role of Syk. Tohyama Y, Yamamura H. ...IUBMB Life. 2006 May-Jun;58(5-6):304-8. (.png) (.svg) (.html) (.csml) Show Complement-mediated phagocytosis-...-the role of Syk. PubmedID 16754322 Title Complement-mediated phagocytosis--the role of Syk. Authors Tohyama

  4. Genotoxic and antigenotoxic properties of selenium compounds in the in vitro micronucleus assay with human whole blood lymphocytes and tk6 lymphoblastoid cells

    Directory of Open Access Journals (Sweden)

    Eduard Cemeli

    2006-01-01

    Full Text Available Selenium is known to possess both genotoxic and antigenotoxic properties. In the present study, we have evaluated the genotoxicity and antigenotoxicity of three selenium compounds (sodium selenate, sodium selenite and selenous acid by measuring in vitro micronucleus induction. Assays were conducted in whole blood lymphocytes and in the TK6 lymphoblastoid cell line, with and without co-treatment with potassium dichromate, a known genotoxic compound. In general, the compounds were more active in TK6 cells than they were in blood lymphocytes. Only 1 μM selenous acid increased the frequency of binucleated cells containing micronuclei (BNMN in blood lymphocytes, while all three selenium compounds increased BNMN in TK6 cells. In addition, combinations of selenous acid and potassium dichromate resulted in lower frequencies of BNMN than potassium dichromate alone in blood lymphocytes, while combinations of sodium selenate and potassium dichromate produced lower frequencies of BNMN than potassium dichromate alone in TK6 cells. The concentrations of selenium compounds that were used, in combination with the medium components and the biological physiology of the whole blood lymphocytes and TK6 cells, could have affected the redox potential of the compounds, switching the chemicals from a pro-oxidant to antioxidant status and vice-versa. The lower activities of the compounds in blood lymphocytes may be due to the protective effects of blood components. The results indicate that the genotoxic and antigenotoxic properties of selenium compounds are highly dependent upon the conditions under which they are evaluated.

  5. Hydrocortisone Increases the Vinblastine-Induced Chromosomal Damages in L929 Cells Investigated by the Micronucleus Assay on Cytokinesis-Blocked Binucleated Cells

    Directory of Open Access Journals (Sweden)

    Tahere Ebrahimipour

    2017-03-01

    Full Text Available Background: Stress may cause damages to DNA or/and change the ability of the cells to overcome these damages. It may also cause irregularities in the cell cycle and induce abnormal cell divisions through glucocorticoid-dependent functions. The abnormal cell divisions, in turn, lead to chromosomal mal-segregation and aneuploidy. In this study, the effects of the stress hormone, hydrocortisone (HYD, were investigated on the induced chromosomal abnormalities by vinblastine (VIN during cell cycle in L929 cells. Methods: This work was performed in winter 2013 at Department of Biology, University of Ferdowsi, Mashhad, Iran. Cultured cells were divided into different groups including control, VIN-treated, HYD treated and VIN+HYD co-treated cells. The induced chromosomal damages were investigated by micronucleus assay in cytokinesis-blocked binucleated cells. Results: Although HYD by itself did not increase the micronuclei (Mn frequency, co-treatment of cells with VIN and HYD led to significant increase (P<0.05 in the frequency of Mn in comparison to control and VIN treated groups. Conclusion: Cells treated with stress hormone are more sensitive to damages induced by VIN. Therefore, stress may not directly result in genetic instability, it can increase the harmful effects associated with other genotoxic agents.

  6. Evaluation of apoptosis and apoptosis proteins as possible markers of radiation at doses 0.1-2 Gy, in comparison to the micronucleus assay in three cell lines

    International Nuclear Information System (INIS)

    Jaworska, A.; Angelis, P. de

    1997-01-01

    In recent years the interest in apoptosis as possible indicator of radiation damage has increased. Studies have been done to examine the induction of apoptosis after ionizing radiation using morphological criteria, characteristic DNA damage pattern(ladders), early DNA damage using flow cytometry and/or expression of the proteins involved in apoptosis. But the picture which emerges from these investigations is unclear. Some researchers suggest that apoptosis studies can be used as potential assays of biological dosimetry, others doubt if apoptosis can be used as a marker of irradiation at all. Most studies have been done using relatively high doses of radiation. In this study we focus on apoptosis induction after relatively small doses (0,1-2 Gy). We detected apoptosis with the in situ terminal deoxynucleotidyl transferase assay by flow cytometry, and measured the expression of proteins that regulate apoptosis (Bcl-2, Bax, P53) with Western blotting. As comparison we used the cytokinesis-block micronucleus assay as a reference. The studies were carried out in three lymphoid cell lines: the mouse lymphoma L5178Y resistant and sensitive cell lines widely used in radiobiological studies, and the human pre-B cell leukemia Reh cells. Our results indicate that we can not consider the examined parameters of apoptosis as markers of radiation in these cell lines. (author)

  7. Enhanced micronucleus formation in the descendants of {gamma}-ray-irradiated tobacco cells: Evidence for radiation-induced genomic instability in plant cells

    Energy Technology Data Exchange (ETDEWEB)

    Yokota, Yuichiro, E-mail: yokota.yuichiro@jaea.go.jp [Life Science and Biotechnology Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Funayama, Tomoo; Hase, Yoshihiro [Life Science and Biotechnology Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Hamada, Nobuyuki [Radiation Safety Research Center, Nuclear Technology Research Laboratory, Central Research Institute of Electric Power Industry, 2-11-1 Iwado-kita, Komae, Tokyo 201-8511 (Japan); Kobayashi, Yasuhiko; Tanaka, Atsushi; Narumi, Issay [Life Science and Biotechnology Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan)

    2010-09-10

    Ionizing radiation-induced genomic instability has been documented in various end points such as chromosomal aberrations and mutations, which arises in the descendants of irradiated mammalian or yeast cells many generations after the initial insult. This study aimed at addressing radiation-induced genomic instability in higher plant tobacco cells. We thus investigated micronucleus (MN) formation and cell proliferation in tobacco cells irradiated with {gamma}-rays and their descendants. In {gamma}-irradiated cells, cell cycle was arrested at G{sub 2}/M phase at around 24 h post-irradiation but released afterward. In contrast, MN frequency peaked at 48 h post-irradiation. Almost half of 40 Gy-irradiated cells had MN at 48 h post-irradiation, but proliferated as actively as sham-irradiated cells up to 120 h post-irradiation. Moreover, the descendants that have undergone at least 22 generations after irradiation still showed a two-fold MN frequency compared to sham-irradiated cells. This is the direct evidence for radiation-induced genomic instability in tobacco cells.

  8. Evaluation of repeated dose micronucleus assays of the liver and gastrointestinal tract using potassium bromate: a report of the collaborative study by CSGMT/JEMS.MMS.

    Science.gov (United States)

    Okada, Emiko; Fujiishi, Yohei; Narumi, Kazunori; Kado, Shoichi; Wako, Yumi; Kawasako, Kazufumi; Kaneko, Kimiyuki; Ohyama, Wakako

    2015-03-01

    The food additive potassium bromate (KBrO3) is known as a renal carcinogen and causes chromosomal aberrations in vitro without metabolic activation and in vivo in hematopoietic and renal cells. As a part of a collaborative study by the Mammalian Mutagenicity Study group, which is a subgroup of the Japanese Environmental Mutagen Society, we administered KBrO3 to rats orally for 4, 14, and 28 days and examined the micronucleated (MNed) cell frequency in the liver, glandular stomach, colon, and bone marrow to confirm whether the genotoxic carcinogen targeting other than liver and gastrointestinal (GI) tract was detected by the repeated dose liver and GI tract micronucleus (MN) assays. In our study, animals treated with KBrO3 showed some signs of toxicity in the kidney and/or stomach. KBrO3 did not increase the frequency of MNed cells in the liver and colon in any of the repeated dose studies. However, KBrO3 increased the frequency of MNed cells in the glandular stomach and bone marrow. Additionally, the MNed cell frequency in the glandular stomach was not significantly affected by the difference in the length of the administration period. These results suggest that performing the MN assay using the glandular stomach, which is the first tissue to contact agents after oral ingestion, is useful for evaluating the genotoxic potential of chemicals and that the glandular stomach MN assay could be integrated into general toxicity studies. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Spores of Mucor ramosissimus, Mucor plumbeus and Mucor circinelloides and their ability to activate human complement system in vitro.

    Science.gov (United States)

    Granja, Luiz Fernando Zmetek; Pinto, Lysianne; Almeida, Cátia Amancio; Alviano, Daniela Sales; Da Silva, Maria Helena; Ejzemberg, Regina; Alviano, Celuta Sales

    2010-03-01

    Complement activation by spores of Mucor ramosissimus, Mucor plumbeus and Mucor circinelloides was studied using absorbed human serum in the presence or absence of chelators (EGTA or EDTA). We found that the spore caused full complement activation when incubated with EGTA-Mg2+ or without chelators, indicating that the alternative pathway is mainly responsible for this response. In order to compare activation profiles from each species, ELISAs for C3 and C4 fragments, mannan binding lectin (MBL), C-reactive protein (CRP) and IgG studies were carried out. All proteins were present on the species tested. Immunofluorescence tests demonstrated the presence of C3 fragments on the surface of all samples, which were confluent throughout fungal surfaces. The same profile of C3, C4, MBL, CRP and IgG deposition, observed in all species, suggests a similar activation behavior for these species.

  10. Spontaneous complement activation on human B cells results in localized membrane depolarization and the clustering of complement receptor type 2 and C3 fragments

    DEFF Research Database (Denmark)

    Løbner, Morten; Leslie, Robert G Q; Prodinger, Wolfgang M

    2009-01-01

    While our previous studies have demonstrated that complement activation induced by complement receptors type 2 (CR2/CD21) and 1 (CR1/CD35) results in C3-fragment deposition and membrane attack complex (MAC) formation in human B cells, the consequences of these events for B-cell functions remain u...

  11. Regulation of Cre recombinase by ligand-induced complementation of inactive fragments.

    Science.gov (United States)

    Jullien, Nicolas; Sampieri, François; Enjalbert, Alain; Herman, Jean-Paul

    2003-11-01

    Cre recombinase is extensively used to engineer the genome of experimental animals. However, its usefulness is still limited by the lack of an efficient temporal control over its activity. To overcome this, we have developed DiCre, a regulatable fragment complementation system for Cre. The enzyme was split into two moieties that were fused to FKBP12 (FK506-binding protein) and FRB (binding domain of the FKBP12-rapamycin-associated protein), respectively. These can be efficiently heterodimerized by rapamycin. Several variants, based on splitting Cre at different sites and using different linker peptides, were tested in an indicator cell line. The fusion proteins, taken separately, had no recombinase activity. Stable transformants, co-expressing complementing fragments based on splitting Cre between Asn59 and Asn60, displayed low background activity affecting 0.05-0.4% of the cells. Rapamycin induced a rapid recombination, reaching 100% by 48-72 h, with an EC50 of 0.02 nM. Thus, ligand-induced dimerization can efficiently regulate Cre, and should be useful to achieve a tight temporal control of its activity, such as in the case of the creation of conditional knock-out animals.

  12. Isolation of the thymidylate synthetase gene (TMP1) by complementation in Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Taylor, G.R.; Barclay, B.J.; Storms, R.K.; Friesen, J.D.; Haynes, R.H.

    1982-01-01

    The structural gene (TMP1) for yeast thymidylate synthetase (thymidylate synthase; EC 2.1.1.45) was isolated from a chimeric plasmid bank by genetic complementation in Saccharomyces cerevisiae. Retransformation of the dTMP auxotroph GY712 and a temperature-sensitive mutant (cdc21) with purified plasmid (pTL1) yielded Tmp/sup +/ transformants at high frequency. In addition, the plasmid was tested for the ability to complement a bacterial thyA mutant that lacks functional thymidylate synthetase. Although it was not possible to select Thy/sup +/ transformants directly, it was found that all pTL1 transformants were phenotypically Thy/sup +/ after several generations of growth in nonselective conditions. Thus, yeast thymidylate synthetase is biologically active in Escherichia coli. Thymidylate synthetase was assayed in yeast cell lysates by high-pressure liquid chromatography to monitor the conversion of [6-/sup 3/H]dUMP to [6-/sup 3/H]dTMP. In protein extracts from the thymidylate auxotroph (tmpl-6) enzymatic conversion of dUMP to dTMP was barely detectable. Lysates of pTL1 transformants of this strain, however, had thymidylate synthetase activity that was comparable to that of the wild-type strain

  13. Possible role of complement activation in renal impairment in trichloroethylene-sensitized guinea pigs

    International Nuclear Information System (INIS)

    Yu, Jun-Feng; Leng, Jing; Shen, Tong; Zhou, Cheng-Fan; Xu, Hui; Jiang, Tao; Xu, Shu-Hai; Zhu, Qi-Xing

    2012-01-01

    Recent studies have revealed that trichloroethylene (TCE) can induce occupational medicamentosa-like dermatitis (OMLD) with multi-system injuries, including liver, kidney and skin injuries, which can subsequently cause multiple organ failure later. But the mechanism of immune dysfunction leading to organ injury was rarely clarified. The present study was initiated to analyze the influence of trichloroethylene on renal injury and study the relevant mechanism in guinea pigs. Guinea pig maximization test (GPMT) was carried out. Inflammation on the guinea pigs’ skin was scored. Kidney function, urine protein and ultra-structural change of kidney were determined by biochemical detection and electron microscope. Deposition of complement 3 and membrane attack complex (MAC, C5b-9) were determined by immunohistochemistry. Erythema and edema of skin impairment were observed in TCE sensitized groups, and sensitization rate was 63.16%. Through electron microscope, tubular epithelial cell mitochondrial swelling, vacuolar degeneration and atrophy of microvillus were observed in TCE sensitized groups. The parameters of urease and urinary protein elevated markedly, and a high degree of C3 and MAC deposition was found in the renal tubular epithelial cells in TCE sensitized groups. By demonstrating that TCE and its metabolites can cause the deposition of C3 and MAC in renal epithelial cells, we found that activated complement system may be the mechanism of the acceleration and the development of TCE-induced kidney disease.

  14. A High-throughput Selection for Cellulase Catalysts Using Chemical Complementation

    Science.gov (United States)

    Peralta-Yahya, Pamela; Carter, Brian T.; Lin, Hening; Tao, Haiyan; Cornish, Virginia W.

    2010-01-01

    Efficient enzymatic hydrolysis of lignocellulosic material remains one of the major bottlenecks to cost-effective conversion of biomass to ethanol. Improvement of glycosylhydrolases however is limited by existing medium-throughput screening technologies. Here, we report the first high-throughput selection for cellulase catalysts. This selection was developed by adapting chemical complementation to provide a growth assay for bond cleavage reactions. First, a URA3 counter selection was adapted to link chemical dimerizer activated gene transcription to cell death. Next, the URA3 counter selection was shown to detect cellulase activity based on cleavage of a tetrasaccharide chemical dimerizer substrate and decrease in expression of the toxic URA3 reporter. Finally, the utility of the cellulase selection was assessed by isolating cellulases with improved activity from a cellulase library created by family DNA shuffling. This application provides further evidence that chemical complementation can be readily adapted to detect different enzymatic activities for important chemical transformations for which no natural selection exists. Due to the large number of enzyme variants selections can test compared to existing medium-throughput screens for cellulases, this assay has the potential to impact the discovery of improved cellulases and other glycosylhydrolases for biomass conversion from libraries of cellulases created by mutagenesis or obtained from natural biodiversity. PMID:19053460

  15. Atypical hemolytic uremic syndrome: Laboratory characteristics, complement-amplifying conditions, renal biopsy, and genetic mutations

    Directory of Open Access Journals (Sweden)

    Mohammad A Hossain

    2018-01-01

    Full Text Available Atypical hemolytic uremic syndrome (aHUS is characterized by microangiopathic hemolytic anemia, consumptive thrombocytopenia, and widespread damage to multiple organs including the kidney. The syndrome has a high mortality necessitating the need for an early diagnosis to limit target organ damage. Because thrombotic microangiopathies present with similar clinical picture, accurate diagnosis of aHUS continues to pose a diagnostic challenge. This article focuses on the role of four distinct aspects of aHUS that assist clinicians in making an accurate diagnosis of aHUS. First, because of the lack of a single specific laboratory test for aHUS, other forms of thrombotic microangiopathies such as thrombotic thrombocytopenic purpura and Shiga toxin-associated HUS must be excluded to successfully establish the diagnosis of aHUS. Second, application of the knowledge of complement-amplifying conditions is critically important in making an accurate diagnosis. Third, when available, a renal biopsy can reveal changes consistent with thrombotic microangiopathy. Fourth, genetic mutations are increasingly clarifying the underlying complement dysfunction and gaining importance in the diagnosis and management of patients with aHUS. This review concentrates on the four aspects of aHUS and calls for heightened awareness in making an accurate diagnosis of aHUS.

  16. The frequency of allelic lethals and complementation maps in natural populations of drosophila melanogaster from Mexico

    Directory of Open Access Journals (Sweden)

    Salceda Victor M.

    2004-01-01

    Full Text Available Departing from a previous study on the genetic loads affecting the second chromosome of Drosophila melanogaster in four natural populations, 171 lethal chromosomes were recovered and maintained as a balanced stocks in the condition Cy L / 1 (l=lethal; of those lethais 24 correspond to population A, 50 to populations B and C and 47 to population D. later on an intra-population allelism test for the four populations was performed for each one. A total of 3807 inter lethal crosses were done yielding a total of i 10 allelic combinations, from them the respective percentage of allelism for each population was calculated and they are as follow: 3.98 % for population A, 1.80 % for population B, 3.67 % for population C and 2.96 % for population D. the observed values for the frequency of allelism in these populations are not significantly different from those reported by other authors in similar studies in natural and/or experimental populations. Beside these values the frequency for singles, doubles, triplets and even quadruplets present in each population were determined, they shown the presence of various complementation maps due to the clustering of few different lethals: also a large complementation map formed by a large cluster involving the presence of 26 different lethals found in population D all of them combined constituting a single unit was found.

  17. Graphs cospectral with a friendship graph or its complement

    Directory of Open Access Journals (Sweden)

    Alireza Abdollahi

    2013-12-01

    Full Text Available Let $n$ be any positive integer and let $F_n$ be the friendship (or Dutch windmill graph with $2n+1$ vertices and $3n$ edges. Here we study graphs with the same adjacency spectrum as the $F_n$. Two graphs are called cospectral if the eigenvalues multiset of their adjacency matrices are the same. Let $G$ be a graph cospectral with $F_n$. Here we prove that if $G$ has no cycle of length $4$ or $5$, then $Gcong F_n$. Moreover if $G$ is connected and planar then $Gcong F_n$.All but one of connected components of $G$ are isomorphic to $K_2$.The complement $overline{F_n}$ of the friendship graph is determined by its adjacency eigenvalues, that is, if $overline{F_n}$ is cospectral with a graph $H$, then $Hcong overline{F_n}$.

  18. Southeast Asia-South America interregionalism: a complement to bilateralism

    Directory of Open Access Journals (Sweden)

    M. Florencia Rubiolo

    2016-09-01

    Full Text Available Inter-state relations between the countries of South America and Southeast Asia (SEA have blossomed in the past 15 years, arousing the interest of a growing number of academics. Their interregional relations, on the other hand, have been less well examined, due, probably, to the fact that their development remains incipient, as well as sporadic and poorly institutionalised. The starting point for this work is the premise that in the case of non-central regions this level of connection complements and works as a feedback mechanism for bilateral links and encourages State-State, State-region and region-region rapprochement. It introduces notions of South American regionalism and centres on concepts related to non-triadic interregionalism in the initiatives between South America and SEA since 1999.

  19. AMD and the alternative complement pathway: genetics and functional implications.

    Science.gov (United States)

    Tan, Perciliz L; Bowes Rickman, Catherine; Katsanis, Nicholas

    2016-06-21

    Age-related macular degeneration (AMD) is an ocular neurodegenerative disorder and is the leading cause of legal blindness in Western societies, with a prevalence of up to 8 % over the age of 60, which continues to increase with age. AMD is characterized by the progressive breakdown of the macula (the central region of the retina), resulting in the loss of central vision including visual acuity. While its molecular etiology remains unclear, advances in genetics and genomics have illuminated the genetic architecture of the disease and have generated attractive pathomechanistic hypotheses. Here, we review the genetic architecture of AMD, considering the contribution of both common and rare alleles to susceptibility, and we explore the possible mechanistic links between photoreceptor degeneration and the alternative complement pathway, a cascade that has emerged as the most potent genetic driver of this disorder.

  20. Electroencephalography Is a Good Complement to Currently Established Dementia Biomarkers

    DEFF Research Database (Denmark)

    Ferreira, Daniel; Jelic, Vesna; Cavallin, Lena

    2016-01-01

    , 135 Alzheimer's disease (AD), 15 dementia with Lewy bodies/Parkinson's disease with dementia (DLB/PDD), 32 other dementias]. The EEG data were recorded in a standardized way. Structural imaging data were visually rated using scales of atrophy in the medial temporal, frontal, and posterior cortex......BACKGROUND/AIMS: Dementia biomarkers that are accessible and easily applicable in nonspecialized clinical settings are urgently needed. Quantitative electroencephalography (qEEG) is a good candidate, and the statistical pattern recognition (SPR) method has recently provided promising results. We......EEG to the diagnostic workup substantially increases the detection of AD pathology even in pre-dementia stages and improves differential diagnosis. EEG could serve as a good complement to currently established dementia biomarkers since it is cheap, noninvasive, and extensively applied outside academic centers....

  1. Chromosome-based genetic complementation system for Xylella fastidiosa.

    Science.gov (United States)

    Matsumoto, Ayumi; Young, Glenn M; Igo, Michele M

    2009-03-01

    Xylella fastidiosa is a xylem-limited, gram-negative bacterium that causes Pierce's disease of grapevine. Here, we describe the construction of four vectors that facilitate the insertion of genes into a neutral site (NS1) in the X. fastidiosa chromosome. These vectors carry a colE1-like (pMB1) replicon and DNA sequences from NS1 flanking a multiple-cloning site and a resistance marker for one of the following antibiotics: chloramphenicol, erythromycin, gentamicin, or kanamycin. In X. fastidiosa, vectors with colE1-like (pMB1) replicons have been found to result primarily in the recovery of double recombinants rather than single recombinants. Thus, the ease of obtaining double recombinants and the stability of the resulting insertions at NS1 in the absence of selective pressure are the major advantages of this system. Based on in vitro and in planta characterizations, strains carrying insertions within NS1 are indistinguishable from wild-type X. fastidiosa in terms of growth rate, biofilm formation, and pathogenicity. To illustrate the usefulness of this system for complementation analysis, we constructed a strain carrying a mutation in the X. fastidiosa cpeB gene, which is predicted to encode a catalase/peroxidase, and showed that the sensitivity of this mutant to hydrogen peroxide could be overcome by the introduction of a wild-type copy of cpeB at NS1. Thus, this chromosome-based complementation system provides a valuable genetic tool for investigating the role of specific genes in X. fastidiosa cell physiology and virulence.

  2. Effect of dialyzer geometry on granulocyte and complement activation.

    Science.gov (United States)

    Schaefer, R M; Heidland, A; Hörl, W H

    1987-01-01

    During hemodialysis with cuprophan membranes, the complement system as well as leukocytes become activated. In order to clarify the role of dialyzer geometry, the effect of hollow-fiber versus flat-sheet dialyzers and of different surface areas on C3a generation and leukocyte degranulation was investigated. Plasma levels of leukocyte elastase in complex with alpha 1-proteinase inhibitor were significantly increased after 1 h (+55%) and 3 h (+62%) of hemodialysis with flat-sheet dialyzers as compared to hollow-fiber devices. In addition, plasma levels of lactoferrin, released from the specific granules of leukocytes during activation, were significantly higher (+42%) 3 h after the onset of dialysis treatment with flat-sheet than with hollow-fiber dialyzers. With respect to surface area, larger dialyzers tended to cause more release of leukocyte elastase as compared to dialyzers with smaller surface areas, irrespectively of the configuration of the dialyzer used. On the other hand, activation of the complement system, as measured by the generation of C3a-desarg, did not differ with both types of configurations. The same held true for leukopenia, which was almost identical for hollow-fiber and flat-sheet dialyzers. From these findings two lines of evidence emerge: First, not only the type of membrane material used in a dialyzer may influence its biocompatibility, but the geometry of the extracorporeal device also determines the degree of compatibility. Hence, the extent of leukocyte activation correlated with both configuration of the dialyzer and surface area of the membrane.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Lupus anticoagulant, disease activity and low complement in the first trimester are predictive of pregnancy loss.

    Science.gov (United States)

    Mankee, Anil; Petri, Michelle; Magder, Laurence S

    2015-01-01

    Multiple factors, including proteinuria, antiphospholipid syndrome, thrombocytopenia and hypertension, are predictive of pregnancy loss in systemic lupus erythematosus (SLE). In the PROMISSE study of predictors of pregnancy loss, only a battery of lupus anticoagulant tests was predictive of a composite of adverse pregnancy outcomes. We examined the predictive value of one baseline lupus anticoagulant test (dilute Russell viper venom time) with pregnancy loss in women with SLE. From the Hopkins Lupus Cohort, there were 202 pregnancies from 175 different women after excluding twin pregnancies and pregnancies for which we did not have a first trimester assessment of lupus anticoagulant. We determined the percentage of women who had a pregnancy loss in groups defined by potential risk factors. The lupus anticoagulant was determined by dilute Russell viper venom time with appropriate mixing and confirmatory testing. Generalised estimating equations were used to calculate p values, accounting for repeated pregnancies in the same woman. The age at pregnancy was 40 (3%). 55% were Caucasian and 34% African-American. Among those with lupus anticoagulant during the first trimester, 6/16 (38%) experienced a pregnancy loss compared with only 16/186 (9%) of other pregnancies (p=0.003). In addition, those with low complement or higher disease activity had a higher rate of pregnancy loss than those without (p=0.049 and 0.005, respectively). In contrast, there was no association between elevated anticardiolipin in the first trimester and pregnancy loss. The strongest predictor of pregnancy loss in SLE in the first trimester is the lupus anticoagulant. In addition, moderate disease activity by the physician global assessment and low complement measured in the first trimester were predictive of pregnancy loss. These data suggest that treatment of the lupus anticoagulant could be considered, even in the absence of history of pregnancy loss.

  4. Micronucleus assay for human peripheral blood lymphocytes as a biomarker of individual sensitivity to assessing radiation health risk in different population

    International Nuclear Information System (INIS)

    Kang, C.-M.; Jeon, H.-J.; Lee, Y.-S.; Lee, S.-J.; Jin, Y.-H.; Kim, Y.-H.; Kim, T.-W.; Cho, C.-K.

    2003-01-01

    Full text: Our studies were to evaluate micronucleus (MN) assay for human peripheral blood lymphocytes (HPBL) as a biomarker of individual sensitivity to assessing radiation health risk in different population in Korea. Further studied are carried out to provide evidence for the existence of individual variations in age-dependent responses. For the MN assay, HPBLs were irradiated with doses of 0, 1, 2, 4, 8Gy 60 Co γ-rays. Spontaneous frequencies not only vary greatly between individuals, but also working or living areas because of the groups with different lifestyle living in different ecological situation and the reaction to radiation exposure. It was shown that the increased level of spontaneous cell with MN was observed with increased age. The relationship between radiosensitivity and the increased spontaneous level of MN may be in inverse proportion. Age and gender are the most important demographic variables impact on MN index with MN frequencies in female being greater than those in male by a factor of depending on the age group. For both sexes, MN frequency was significantly and positively correlated with age. The main lifestyle factors influencing the MN index in subjects are significantly and positively correlated with smoking in measuring the spontaneous frequencies of micronuclei. The described results show that the genetic damaged rate like MN index in human populations is correlated significantly with age, sex and lifestyle factors. So far, it is evident that with regard to the application of MN assay all future studies to evaluate radiation health risks in different population have to take into account the influence of age, gender, and lifestyle. The results suggested that the MN assay have a high potential to ensure appropriate quality control and standard documentation protocol which can be used to monitor a large population exposed to radiation epidemiologically. We conclude that the determination of individual radiosensitivity with MN assay is

  5. Differences in micronucleus induction in peripheral blood reticulocytes of mice exposed to N-ethyl-N-nitrosourea at light and dark dosing times.

    Science.gov (United States)

    Itoh, Keiichi; Masumori, Shoji; Nakajima, Madoka; Hayashi, Makoto; Sakakibara, Hiroyuki; Shimoi, Kayoko

    2012-01-01

    Mammals, including human beings, have a circadian clock system to regulate behavioral and physiological processes. In this study, we investigated the effect of dosing time on micronucleus induction in the bone marrow by evaluating the frequencies of micronucleated peripheral reticulocytes (MNRETs) in mice exposed to N-ethyl-N-nitrosourea (ENU) to assess any difference in genotoxic sensitivity to chemicals between light and dark periods (inactive phase for rodents and active phase for rodents). Male C3H/He mice were treated intraperitoneally with ENU (12.5 or 25 mg/kg body weight) at zeitgeber time (ZT) 3 in the light period or ZT15 in the dark period, and then the time courses of the frequencies of the MNRETs were determined. The frequencies of the MNRETs induced by ENU increased time-dependently and peaked at 48 hr after treatment for ZT3 and ZT15, and were obviously higher in the ZT15 treatment group than the ZT3 treatment group. The MNRETs were measured at 48 hr after treatment with ENU (25 mg/kg body weight) at various dosing times (ZT0, 3, 6, 12, 15 and 18). The frequencies of the MNRETs in mice treated at ZT0, 15 and 18 were significantly higher than those in mice treated at ZT3, 6 and 12. These results suggest that genotoxic sensitivity to chemicals in mouse bone marrow is different between light and dark periods maybe due to different biological responses (detoxification, cell cycle, DNA repair, etc.) related to circadian rhythms.

  6. Duodenal crypt health following exposure to Cr(VI): Micronucleus scoring, γ-H2AX immunostaining, and synchrotron X-ray fluorescence microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Chad M.; Wolf, Jeffrey C.; Elbekai, Reem H.; Paranjpe, Madhav G.; Seiter, Jennifer M.; Chappell, Mark A.; Tappero, Ryan V.; Suh, Mina; Proctor, Deborah M.; Bichteler, Anne; Haws, Laurie C.; Harris, Mark A.

    2015-08-01

    Lifetime exposure to high concentrations of hexavalent chromium [Cr(VI)] in drinking water results in intestinal damage and an increase in duodenal tumors in B6C3F1 mice. To assess whether these tumors could be the result of a direct mutagenic or genotoxic mode of action, we conducted a GLP-compliant 7-day drinking water study to assess crypt health along the entire length of the duodenum. Mice were exposed to water (vehicle control), 1.4, 21, or 180 ppm Cr(VI) via drinking water for 7 consecutive days. Crypt enterocytes in Swiss roll sections were scored as normal, mitotic, apoptotic, karyorrhectic, or as having micronuclei. A single oral gavage of 50 mg/kg cyclophosphamide served as a positive control for micronucleus induction. Exposure to 21 and 180 ppm Cr(VI) significantly increased the number of crypt enterocytes. Micronuclei and γ-H2AX immunostaining were not elevated in the crypts of Cr(VI)-treated mice. In contrast, treatment with cyclophosphamide significantly increased numbers of crypt micronuclei and qualitatively increased γ-H2AX immunostaining. Synchrotron-based X-ray fluorescence (XRF) microscopy revealed the presence of strong Cr fluorescence in duodenal villi, but negligible Cr fluorescence in the crypt compartment. Together, these data indicate that Cr(VI) does not adversely effect the crypt compartment where intestinal stem cells reside, and provide additional evidence that the mode of action for Cr(VI)-induced intestinal cancer in B6C3F1 mice involves chronic villous wounding resulting in compensatory crypt enterocyte hyperplasia.

  7. No evidence of chromosome damage in children and adolescents with differentiated thyroid carcinoma after receiving {sup 131}I radiometabolic therapy, as evaluated by micronucleus assay and microarray analysis

    Energy Technology Data Exchange (ETDEWEB)

    Federico, Giovanni; Fiore, Lisa; Massart, Francesco; Saggese, Giuseppe [Azienda Ospedaliero-Universitaria Pisana, Department of Pediatrics, Unit of Pediatric Endocrinology and Diabetes, Pisa (Italy); Boni, Giuseppe; Lazzeri, Patrizia; Mariani, Giuliano [Azienda Ospedaliero-Universitaria Pisana, Unit of Nuclear Medicine, Pisa (Italy); Fabiani, Barbara; Verola, Carmela; Scarpato, Roberto [University of Pisa, Department of Biology, Unit of Genetics, Mutagenesis and Environmental Epidemiology, Pisa (Italy); Traino, Claudio [Azienda Ospedaliero-Universitaria Pisana, Health Physics Service, Pisa (Italy)

    2008-11-15

    As {sup 131}I therapy, used to achieve ablation of thyroid gland remnant, can cause chromosome damage in cultured peripheral lymphocytes especially, we investigated whether administration of radioiodine may induce early genome damage in peripheral T lymphocytes of adolescents with differentiated thyroid carcinoma (DTC). We studied 11 patients, aged 14.8 {+-} 3.1 years, who assumed {sup 131}I (range: 1.11-4.44 GBq) to ablate thyroid remnant. A blood sample for micronucleus assay and for evaluating expression of some genes involved in the DNA repair or the apoptosis pathways was obtained from each patient 1 h before (T{sub 0}) and 24 (T{sub 1}) and 48 h (T{sub 2}) post-radioiodine administration. Compared to T{sub 0}, we did not find any difference in the number of micronucleated cells at both T{sub 1} and T{sub 2} in any subject. Nine out of 11 patients had altered expression levels in a majority of the DNA repair and apoptosis genes at T{sub 1}, which decreased at T{sub 2}. We demonstrated for the first time that peripheral cells of DTC children and adolescents who received {sup 131}I at a mean dosage of 3.50 {+-} 0.37 GBq did not show chromosome damage within 48 h from the end of radiometabolic therapy. This may be due to a prompt activation of the cell machinery that maintains the integrity of the genome to prevent harmful double-strand breaks from progressing to chromosome mutations, either by repairing the lesions or by eliminating the most seriously damaged cells via apoptosis. (orig.)

  8. The effect of an optimized imaging flow cytometry analysis template on sample throughput in the reduced culture cytokinesis-block micronucleus assay

    International Nuclear Information System (INIS)

    Rodrigues, M.A.; Beaton-Green, L.A.; Wilkins, R.C.; Probst, C.E.

    2016-01-01

    In cases of overexposure to ionizing radiation, the cytokinesis-block micronucleus (CBMN) assay can be performed in order to estimate the dose of radiation to an exposed individual. However, in the event of a large-scale radiation accident with many potentially exposed casualties, the assay must be able to generate accurate dose estimates to within ±0.5 Gy as quickly as possible. The assay has been adapted to, validated and optimized on the ImageStream"X imaging flow cyto-meter. The ease of running this automated version of the CBMN assay allowed investigation into the accuracy of dose estimates after reducing the volume of whole blood cultured to 200 μl and reducing the culture time to 48 h. The data analysis template used to identify binucleated lymphocyte cells (BNCs) and micronuclei (MN) has since been optimized to improve the sensitivity and specificity of BNC and MN detection. This paper presents a re-analysis of existing data using this optimized analysis template to demonstrate that dose estimations from blinded samples can be obtained to the same level of accuracy in a shorter data collection time. Here, we show that dose estimates from blinded samples were obtained to within ±0.5 Gy of the delivered dose when data collection time was reduced by 30 min at standard culture conditions and by 15 min at reduced culture conditions. Reducing data collection time while retaining the same level of accuracy in our imaging flow cytometry-based version of the CBMN assay results in higher throughput and further increases the relevancy of the CBMN assay as a radiation bio-dosimeter. (authors)

  9. The role of complement in CD4⁺ T cell homeostasis and effector functions.

    Science.gov (United States)

    Kolev, Martin; Le Friec, Gaëlle; Kemper, Claudia

    2013-02-01

    The complement system is among the evolutionary oldest 'players' of the immune system. It was discovered in 1896 by Jules Bordet as a heat-labile fraction of the serum responsible for the opsonisation and subsequent killing of bacteria. The decades between the 1920s and 1990s then marked the discovery and biochemical characterization of the proteins comprising the complement system. Today, complement is defined as a complex system consisting of more than 30 membrane-bound and soluble plasma proteins, which are activated in a cascade-like manner, very similarly to the caspase proteases and blood coagulation systems. Complement is engrained in the immunologist's mind as a serum-effective, quintessential part of innate immunity, vitally required for the detection and removal of pathogens or other dangerous entities. Three decades ago, this rather confined definition was challenged and then refined when it was shown that complement participates vitally in the induction and regulation of B cell responses, thus adaptive immunity. Similarly, research work published in more recent years supports an equally important role for the complement system in shaping T cell responses. Today, we are again facing paradigm shifts in the field: complement is actively involved in the negative control of T cell effector immune responses, and thus, by definition in immune homeostasis. Further, while serum complement activity is without doubt fundamental in the defence against invading pathogens, local immune cell-derived production of complement emerges as key mediator of complement's impact on adaptive immune responses. And finally, the impact of complement on metabolic pathways and the crosstalk between complement and other immune effector systems is likely more extensive than previously anticipated and is fertile ground for future discoveries. In this review, we will discuss these emerging new roles of complement, with a focus on Th1 cell biology. Copyright © 2013 Elsevier Ltd. All

  10. Complement in patients receiving maintenance hemodialysis: functional screening and quantitative analysis

    Directory of Open Access Journals (Sweden)

    Horikoshi Satoshi

    2010-12-01

    Full Text Available Abstract Background The complement system is vital for innate immunity and is implicated in the pathogenesis of inflammatory diseases and the mechanism of host defense. Complement deficiencies occasionally cause life-threatening diseases. In hemodialysis (HD patients, profiles on complement functional activity and deficiency are still obscure. The objectives of the present study were to measure the functional complement activities of the classical pathway (CP, lectin pathway (LP and alternative pathway (AP using a novel method and consequently to elucidate the rates of deficiencies among HD patients. Methods In the present study, 244 HD patients at one dialysis center and 204 healthy controls were enrolled. Functional complement activities were measured simultaneously using the Wielisa®-kit. The combination of the results of these three pathway activities allows us to speculate which candidate complement is deficient; subsequently, the deficient complement was determined. Results All three functional complement activities were significantly higher in the HD patients than in the control group (P ®-kit, 16 sera (8.8% with mannose-binding lectin (MBL deficiency, 1 serum (0.4% with C4 deficiency, 1 serum (0.4% with C9 deficiency, and 1 serum (0.4% with B deficiency were observed in the HD group, and 18 sera (8.8% with MBL deficiency and 1 serum (0.5% with B deficiency were observed in the control group. There were no significant differences in the 5-year mortality rate between each complement-deficient group and the complement-sufficient group among the HD patients. Conclusion This is the first report that profiles complement deficiencies by simultaneous measurement of functional activities of the three complement pathways in HD patients. Hemodialysis patients frequently suffer from infections or malignancies, but functional complement deficiencies do not confer additional risk of mortality.

  11. Complementing theoretical biochemistry with the uso of computer aids (Symposium

    Directory of Open Access Journals (Sweden)

    R Herrera

    2012-05-01

    Full Text Available Teaching  biochemistry  in  the  current  state  of  science  and  society  requires  a  special motivation for learning, especially for students where Biochemistry is one of the courses on  their  careers.  The  traditional  way  of  teaching,  based  on  the  teacher-student relationship,  mostly  unidirectional,  does  not  fulfil  the  needs  imposed  in  this  era. Considering  the  current  situation,  University  students  require  new  abilities  in  their training  and  the  use  of  computers  can  be  a  facility  for  discovering  and  research, enabling the experience of new and  diverse situations. The design of teaching material for undergraduate students who take biochemistry as complementary course should be seen  as  an  opportunity  to  complement  theoretical  aspect  on  the  current  courses.  We have used three different approaches: (I Modelling proteins indicating key motifs at the three-dimensional structure and residues where inhibitors can be attach. (II Generation of  activities  by  the  use  of  sensors.  And  (III  elaborating  active  quizzes  where  students can  be  drive  on  their  learning.  Building  knowledge  based  on  practical  experience  can improve  student’s  competence  on  basic  science  and  the  learning  process  can  be complemented in the use of dynamics models.

  12. Genetic disorders of vitamin B12 metabolism: eight complementation groups – eight genes

    Science.gov (United States)

    Froese, D. Sean; Gravel, Roy A.

    2010-01-01

    Vitamin B12 (cobalamin, Cbl) is an essential nutrient in human metabolism. Genetic diseases of vitamin B12 utilisation constitute an important fraction of inherited newborn disease. Functionally, B12 is the cofactor for methionine synthase and methylmalonyl CoA mutase. To function as a cofactor, B12 must be metabolised through a complex pathway that modifies its structure and takes it through subcellular compartments of the cell. Through the study of inherited disorders of vitamin B12 utilisation, the genes for eight complementation groups have been identified, leading to the determination of the general structure of vitamin B12 processing and providing methods for carrier testing, prenatal diagnosis and approaches to treatment. PMID:21114891

  13. Automotive airborne brake wear debris nanoparticles and cytokinesis-block micronucleus assay in peripheral blood lymphocytes: A pilot study.

    Science.gov (United States)

    Kazimirova, Alena; Peikertova, Pavlina; Barancokova, Magdalena; Staruchova, Marta; Tulinska, Jana; Vaculik, Miroslav; Vavra, Ivo; Kukutschova, Jana; Filip, Peter; Dusinska, Maria

    2016-07-01

    Motor vehicle exhaust and non-exhaust processes play a significant role in environmental pollution, as they are a source of the finest particulate matter. Emissions from non-exhaust processes include wear-products of brakes, tires, automotive hardware, road surface, and traffic signs, but still are paid little attention to. Automotive friction composites for brake pads are composite materials which may consist of potentially hazardous materials and there is a lack of information regarding the potential influence of the brake wear debris (BWD) on the environment, especially on human health. Thus, we focused our study on the genotoxicity of the airborne fraction of BWD using a brake pad model representing an average low-metallic formulation available in the EU market. BWD was generated in the laboratory by a full-scale brake dynamometer and characterized by Raman microspectroscopy, scanning electron microscopy, and transmission electron microscopy showing that it contains nano-sized crystalline metal-based particles. Genotoxicity tested in human lymphocytes in different testing conditions showed an increase in frequencies of micronucleated binucleated cells (MNBNCs) exposed for 48h to BWD nanoparticles (NPs) (with 10% of foetal calf serum in culture medium) compared with lymphocytes exposed to medium alone, statistically significant only at the concentration 3µg/cm(2) (p=0.032). Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Large Covariance Estimation by Thresholding Principal Orthogonal Complements

    Science.gov (United States)

    Fan, Jianqing; Liao, Yuan; Mincheva, Martina

    2012-01-01

    This paper deals with the estimation of a high-dimensional covariance with a conditional sparsity structure and fast-diverging eigenvalues. By assuming sparse error covariance matrix in an approximate factor model, we allow for the presence of some cross-sectional correlation even after taking out common but unobservable factors. We introduce the Principal Orthogonal complEment Thresholding (POET) method to explore such an approximate factor structure with sparsity. The POET estimator includes the sample covariance matrix, the factor-based covariance matrix (Fan, Fan, and Lv, 2008), the thresholding estimator (Bickel and Levina, 2008) and the adaptive thresholding estimator (Cai and Liu, 2011) as specific examples. We provide mathematical insights when the factor analysis is approximately the same as the principal component analysis for high-dimensional data. The rates of convergence of the sparse residual covariance matrix and the conditional sparse covariance matrix are studied under various norms. It is shown that the impact of estimating the unknown factors vanishes as the dimensionality increases. The uniform rates of convergence for the unobserved factors and their factor loadings are derived. The asymptotic results are also verified by extensive simulation studies. Finally, a real data application on portfolio allocation is presented. PMID:24348088

  15. Yersinia pestis targets neutrophils via complement receptor 3

    Science.gov (United States)

    Merritt, Peter M.; Nero, Thomas; Bohman, Lesley; Felek, Suleyman; Krukonis, Eric S.; Marketon, Melanie M.

    2015-01-01

    Yersinia species display a tropism for lymphoid tissues during infection, and the bacteria select innate immune cells for delivery of cytotoxic effectors by the type III secretion system. Yet the mechanism for target cell selection remains a mystery. Here we investigate the interaction of Yersinia pestis with murine splenocytes to identify factors that participate in the targeting process. We find that interactions with primary immune cells rely on multiple factors. First, the bacterial adhesin Ail is required for efficient targeting of neutrophils in vivo. However, Ail does not appear to directly mediate binding to a specific cell type. Instead, we find that host serum factors direct Y. pestis to specific innate immune cells, particularly neutrophils. Importantly, specificity towards neutrophils was increased in the absence of bacterial adhesins due to reduced targeting of other cell types, but this phenotype was only visible in the presence of mouse serum. Addition of antibodies against complement receptor 3 and CD14 blocked target cell selection, suggesting that a combination of host factors participate in steering bacteria toward neutrophils during plague infection. PMID:25359083

  16. Exclusivity structures and graph representatives of local complementation orbits

    Science.gov (United States)

    Cabello, Adán; Parker, Matthew G.; Scarpa, Giannicola; Severini, Simone

    2013-07-01

    We describe a construction that maps any connected graph G on three or more vertices into a larger graph, H(G), whose independence number is strictly smaller than its Lovász number which is equal to its fractional packing number. The vertices of H(G) represent all possible events consistent with the stabilizer group of the graph state associated with G, and exclusive events are adjacent. Mathematically, the graph H(G) corresponds to the orbit of G under local complementation. Physically, the construction translates into graph-theoretic terms the connection between a graph state and a Bell inequality maximally violated by quantum mechanics. In the context of zero-error information theory, the construction suggests a protocol achieving the maximum rate of entanglement-assisted capacity, a quantum mechanical analogue of the Shannon capacity, for each H(G). The violation of the Bell inequality is expressed by the one-shot version of this capacity being strictly larger than the independence number. Finally, given the correspondence between graphs and exclusivity structures, we are able to compute the independence number for certain infinite families of graphs with the use of quantum non-locality, therefore highlighting an application of quantum theory in the proof of a purely combinatorial statement.

  17. Large Covariance Estimation by Thresholding Principal Orthogonal Complements.

    Science.gov (United States)

    Fan, Jianqing; Liao, Yuan; Mincheva, Martina

    2013-09-01

    This paper deals with the estimation of a high-dimensional covariance with a conditional sparsity structure and fast-diverging eigenvalues. By assuming sparse error covariance matrix in an approximate factor model, we allow for the presence of some cross-sectional correlation even after taking out common but unobservable factors. We introduce the Principal Orthogonal complEment Thresholding (POET) method to explore such an approximate factor structure with sparsity. The POET estimator includes the sample covariance matrix, the factor-based covariance matrix (Fan, Fan, and Lv, 2008), the thresholding estimator (Bickel and Levina, 2008) and the adaptive thresholding estimator (Cai and Liu, 2011) as specific examples. We provide mathematical insights when the factor analysis is approximately the same as the principal component analysis for high-dimensional data. The rates of convergence of the sparse residual covariance matrix and the conditional sparse covariance matrix are studied under various norms. It is shown that the impact of estimating the unknown factors vanishes as the dimensionality increases. The uniform rates of convergence for the unobserved factors and their factor loadings are derived. The asymptotic results are also verified by extensive simulation studies. Finally, a real data application on portfolio allocation is presented.

  18. Antibodies Against Complement Components: Relevance for the Antiphospholipid Syndrome-Biomarkers of the Disease and Biopharmaceuticals.

    Science.gov (United States)

    Bećarević, Mirjana

    2017-07-01

    Laboratory criterion for the diagnosis of antiphospholipid syndrome (APS) is the presence of antiphospholipid antibodies (aPL Abs). Complement system has a role in mediating aPL Abs-induced thrombosis in animal models. The importance of antibodies against complement components (potential biomarkers of APS) and the importance of antibodies with beneficial anti-complement effects in APS (as biopharmaceuticals) are reviewed. Antibodies against complement components described in APS patients, so far, are anti-C1q and anti-factor H Abs, although anti-factor B Abs and anti-C5a Abs were described in animal models of APS. Clinical studies in APS patients are limited to a small number of case reports. Studies that would confirm potential role of Abs against complement components (as potential biomarkers of APS) are lacking. Lack of randomized clinical trials (that would provide complete data for confirmation of beneficial effects of biopharmaceuticals in complement inhibition) in APS is alarming.

  19. Practical aspects of mutagenicity testing strategy: an industrial perspective.

    Science.gov (United States)

    Gollapudi, B B; Krishna, G

    2000-11-20

    Genetic toxicology studies play a central role in the development and marketing of new chemicals for pharmaceutical, agricultural, industrial, and consumer use. During the discovery phase of product development, rapid screening tests that require minimal amounts of test materials are used to assist in the design and prioritization of new molecules. At this stage, a modified Salmonella reverse mutation assay and an in vitro micronucleus test with mammalian cell culture are frequently used for screening. Regulatory genetic toxicology studies are conducted with a short list of compounds using protocols that conform to various international guidelines. A set of four assays usually constitutes the minimum test battery that satisfies global requirements. This set includes a bacterial reverse mutation assay, an in vitro cytogenetic test with mammalian cell culture, an in vitro gene mutation assay in mammalian cell cultures, and an in vivo rodent bone marrow micronucleus test. Supplementary studies are conducted in certain instances either as a follow-up to the findings from this initial testing battery and/or to satisfy a regulatory requirement. Currently available genetic toxicology assays have helped the scientific and industrial community over the past several decades in evaluating the mutagenic potential of chemical agents. The emerging field of toxicogenomics has the potential to redefine our ability to study the response of cells to genetic damage and hence our ability to study threshold phenomenon.

  20. Automotive airborne brake wear debris nanoparticles and cytokinesis-block micronucleus assay in peripheral blood lymphocytes: A pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Kazimirova, Alena, E-mail: alena.kazimirova@szu.sk [Department of Biology, Faculty of Medicine, Slovak Medical University, Limbova 12, 833 03 Bratislava (Slovakia); Peikertova, Pavlina [Nanotechnology Centre, VŠB – Technical University of Ostrava, 17. listopadu 15, 708 00 Ostrava (Czech Republic); IT4Innovations, VŠB – Technical University of Ostrava, 17. listopadu 15, 708 33 Ostrava-Poruba (Czech Republic); Barancokova, Magdalena; Staruchova, Marta; Tulinska, Jana [Department of Biology, Faculty of Medicine, Slovak Medical University, Limbova 12, 833 03 Bratislava (Slovakia); Vaculik, Miroslav [Nanotechnology Centre, VŠB – Technical University of Ostrava, 17. listopadu 15, 708 00 Ostrava (Czech Republic); Vavra, Ivo [Nanotechnology Centre, VŠB – Technical University of Ostrava, 17. listopadu 15, 708 00 Ostrava (Czech Republic); Institute of Electrical Engineering, Slovak Academy of Sciences, Dúbravská Cesta 9, 841 03 Bratislava (Slovakia); Kukutschova, Jana [Nanotechnology Centre, VŠB – Technical University of Ostrava, 17. listopadu 15, 708 00 Ostrava (Czech Republic); Filip, Peter [Department of Mechanical Engineering and Energy Processes, Southern Illinois University, Lincoln Drive 1263, 62901 Carbondale (United States); Dusinska, Maria [Health Effects Laboratory, Department of Environmental Chemistry, NILU-Norwegian Institute for Air Research, Instituttveien 18, 2007 Kjeller (Norway)

    2016-07-15

    Motor vehicle exhaust and non-exhaust processes play a significant role in environmental pollution, as they are a source of the finest particulate matter. Emissions from non-exhaust processes include wear-products of brakes, tires, automotive hardware, road surface, and traffic signs, but still are paid little attention to. Automotive friction composites for brake pads are composite materials which may consist of potentially hazardous materials and there is a lack of information regarding the potential influence of the brake wear debris (BWD) on the environment, especially on human health. Thus, we focused our study on the genotoxicity of the airborne fraction of BWD using a brake pad model representing an average low-metallic formulation available in the EU market. BWD was generated in the laboratory by a full-scale brake dynamometer and characterized by Raman microspectroscopy, scanning electron microscopy, and transmission electron microscopy showing that it contains nano-sized crystalline metal-based particles. Genotoxicity tested in human lymphocytes in different testing conditions showed an increase in frequencies of micronucleated binucleated cells (MNBNCs) exposed for 48 h to BWD nanoparticles (NPs) (with 10% of foetal calf serum in culture medium) compared with lymphocytes exposed to medium alone, statistically significant only at the concentration 3 µg/cm{sup 2} (p=0.032). - Highlights: • BWD was characterized by Raman microspectroscopy, scanning electron microscopy, and transmission electron microscopy. • Our result showed that BWD contains crystalline metal NPs. • Two different protocols for CBMN assay were used to study of genotoxicity of BWD. • We found significantly increased frequency of MNBNCs after 48 h exposure of BWD (with 10% of foetal calf serum in culture media) at the concentration 3 µg/cm{sup 2}.

  1. Automotive airborne brake wear debris nanoparticles and cytokinesis-block micronucleus assay in peripheral blood lymphocytes: A pilot study

    International Nuclear Information System (INIS)

    Kazimirova, Alena; Peikertova, Pavlina; Barancokova, Magdalena; Staruchova, Marta; Tulinska, Jana; Vaculik, Miroslav; Vavra, Ivo; Kukutschova, Jana; Filip, Peter; Dusinska, Maria

    2016-01-01

    Motor vehicle exhaust and non-exhaust processes play a significant role in environmental pollution, as they are a source of the finest particulate matter. Emissions from non-exhaust processes include wear-products of brakes, tires, automotive hardware, road surface, and traffic signs, but still are paid little attention to. Automotive friction composites for brake pads are composite materials which may consist of potentially hazardous materials and there is a lack of information regarding the potential influence of the brake wear debris (BWD) on the environment, especially on human health. Thus, we focused our study on the genotoxicity of the airborne fraction of BWD using a brake pad model representing an average low-metallic formulation available in the EU market. BWD was generated in the laboratory by a full-scale brake dynamometer and characterized by Raman microspectroscopy, scanning electron microscopy, and transmission electron microscopy showing that it contains nano-sized crystalline metal-based particles. Genotoxicity tested in human lymphocytes in different testing conditions showed an increase in frequencies of micronucleated binucleated cells (MNBNCs) exposed for 48 h to BWD nanoparticles (NPs) (with 10% of foetal calf serum in culture medium) compared with lymphocytes exposed to medium alone, statistically significant only at the concentration 3 µg/cm 2 (p=0.032). - Highlights: • BWD was characterized by Raman microspectroscopy, scanning electron microscopy, and transmission electron microscopy. • Our result showed that BWD contains crystalline metal NPs. • Two different protocols for CBMN assay were used to study of genotoxicity of BWD. • We found significantly increased frequency of MNBNCs after 48 h exposure of BWD (with 10% of foetal calf serum in culture media) at the concentration 3 µg/cm 2 .

  2. Relationship of Circulating C5a and Complement Factor H Levels With Disease Control in Pregnant Women With Asthma.

    Science.gov (United States)

    Bohács, Anikó; Bikov, András; Ivancsó, István; Czaller, Ibolya; Böcskei, Renáta; Müller, Veronika; Rigó, János; Losonczy, György; Tamási, Lilla

    2016-04-01

    Asthma often complicates pregnancy and represents a risk of serious pregnancy complications. The complement system contributes to asthma pathogenesis and is up-regulated in healthy gestation as well. The anaphylatoxin C5a has a major pro-inflammatory role, and the complement factor H is a main soluble regulator protein both in asthma and during pregnancy; however, peripheral levels of these complement factors and their relationship to disease control have not yet been evaluated in pregnant subjects with asthma. The present study aimed to investigate circulating C5a and complement factor H levels in asthma (non-pregnant subjects with asthma; n = 19) and in pregnancy with asthma (pregnant subjects with asthma; n = 22), compared with healthy non-pregnant (n = 21) and healthy pregnant women (n = 13) and to test their relationship to clinical parameters of asthma (lung function, airway inflammation, and symptoms). Circulating C5a levels were higher in the pregnant asthma subject group compared with the healthy non-pregnant, healthy pregnant, and non-pregnant asthma groups: median 2.629 (interquartile range [IQR] 2.257-3.052) ng/mL versus 1.84 (IQR 1.576-2.563), 1.783 (IQR 0.6064-2.786), and 2.024 (IQR 1.232-2.615) ng/mL, respectively (P = .02 in all cases). C5a correlated negatively with FEV1 (r = -0.44, P = .039) and FVC values (r = -0.64, P = .001) in the pregnant asthma group and positively with fraction of exhaled nitric oxide levels in the non-pregnant asthma group (n = 12, r = 0.78, P = .004). Complement factor H levels were elevated in both the healthy pregnant and pregnant asthma subject groups compared with the healthy non-pregnant group (median 1,082 [IQR 734.9-1,224] and 910.7 [IQR 614.5-1076] μg/mL vs. 559.7 [IQR 388.7-783.1] μg/mL, P = .002 and P = .004, respectively) but not in the pregnant asthma group compared with the non-pregnant asthma group (median 687.4 [IQR 441.6-947.6] μg/mL, P = .10). Asthma during pregnancy increases the circulating level of

  3. Complement-mediated bactericidal activity of anti-factor H binding protein monoclonal antibodies against the meningococcus relies upon blocking factor H binding.

    Science.gov (United States)

    Giuntini, Serena; Reason, Donald C; Granoff, Dan M

    2011-09-01

    Binding of the complement-downregulating protein factor H (fH) to the surface of the meningococcus is important for survival of the organism in human serum. The meningococcal vaccine candidate factor H binding protein (fHbp) is an important ligand for human fH. While some fHbp-specific monoclonal antibodies (MAbs) block binding of fH to fHbp, the stoichiometry of blocking in the presence of high serum concentrations of fH and its effect on complement-mediated bactericidal activity are unknown. To investigate this question, we constructed chimeric antibodies in which the human IgG1 constant region was paired with three murine fHbp-specific binding domains designated JAR 3, JAR 5, and MAb502. By surface plasmon resonance, the association rates for binding of all three MAbs to immobilized fHbp were >50-fold higher than that for binding of fH to fHbp, and the MAb dissociation rates were >500-fold lower than that for fH. While all three MAbs elicited similar C1q-dependent C4b deposition on live bacteria (classical complement pathway), only those antibodies that inhibited binding of fH to fHbp (JAR 3 and JAR 5) had bactericidal activity with human complement. MAb502, which did not inhibit fH binding, had complement-mediated bactericidal activity only when tested with fH-depleted human complement. When an IgG1 anti-fHbp MAb binds to sparsely exposed fHbp on the bacterial surface, there appears to be insufficient complement activation for bacteriolysis unless fH binding also is inhibited. The ability of fHbp vaccines to elicit protective antibodies, therefore, is likely to be enhanced if the antibody repertoire is of high avidity and includes fH-blocking activity.

  4. Influence of complement on neutrophil extracellular trap release induced by bacteria

    DEFF Research Database (Denmark)

    Palmer, Lisa Joanne; Damgaard, Christian; Holmstrup, Palle

    2016-01-01

    by Staphylococcus aureus and three oral bacteria: Actinomyces viscosus, Aggregatibacter actinomycetemcomitans and Fusobacterium nucleatum subsp. vincettii. Material and Methods Bacteria-stimulated NET release from the neutrophils of healthy donors was measured fluorometrically. Various complement containing...... In conclusion, complement opsonization promotes NET release induced by a variety of bacteria, including A. actinomycetemcomitans, and CR1 plays a dominant role in the process. Complement consumption or deficiency may compromise NETosis induced by some bacterial species, including A. actinomycetemcomitans....... Within biofilms, the complement-inactivating abilities of some bacteria may protect other species against NETosis, while these are more vulnerable when adopting a planktonic lifestyle....

  5. The complement system and its role in the pathogenesis of periodontitis

    DEFF Research Database (Denmark)

    Damgaard, Christian; Holmstrup, Palle; Van Dyke, Thomas E.

    2015-01-01

    Periodontitis is a highly prevalent inflammatory disease in tooth supporting tissues, induced by bacteria growing in a biofilm on tooth surfaces. Components of the complement system are present in the periodontal tissue and the system is activated in periodontitis. Continuous complement activation...... and modulation by bacteria within the biofilm in periodontal pockets, however, may enhance local tissue destruction, providing the biofilm with both essential nutrients and space to grow. A more profound understanding of the mechanisms involved in complement-derived tissue degradation may facilitate...... with an emphasis on interaction of complement with bacteria from periodontitis-associated biofilm....

  6. Novel roles of complement in renal diseases and their therapeutic consequences.

    Science.gov (United States)

    Wada, Takehiko; Nangaku, Masaomi

    2013-09-01

    The complement system functions as a part of the innate immune system. Inappropriate activation of the complement pathways has a deleterious effect on kidneys. Recent advances in complement research have provided new insights into the pathogenesis of glomerular and tubulointerstitial injury associated with complement activation. A new disease entity termed 'C3 glomerulopathy' has recently been proposed and is characterized by isolated C3 deposition in glomeruli without positive staining for immunoglobulins. Genetic and functional studies have demonstrated that several different mutations and disease variants, as well as the generation of autoantibodies, are potentially associated with its pathogenesis. The data from comprehensive analyses suggest that complement dysregulation can also be associated with hemolytic uremic syndrome and more common glomerular diseases, such as IgA nephropathy and diabetic kidney disease. In addition, animal studies utilizing genetically modified mice have begun to elucidate the molecular pathomechanisms associated with the complement system. From a diagnostic point of view, a noninvasive, MRI-based method for detecting C3 has recently been developed to serve as a novel tool for diagnosing complement-mediated kidney diseases. While novel therapeutic tools related to complement regulation are emerging, studies evaluating the precise roles of the complement system in kidney diseases will still be useful for developing new therapeutic approaches.

  7. SALO, a novel classical pathway complement inhibitor from saliva of the sand fly Lutzomyia longipalpis

    OpenAIRE

    Viviana P. Ferreira; Vladimir Fazito Vale; Michael K. Pangburn; Maha Abdeladhim; Antonio Ferreira Mendes-Sousa; Iliano V. Coutinho-Abreu; Manoochehr Rasouli; Elizabeth A. Brandt; Claudio Meneses; Kolyvan Ferreira Lima; Ricardo Nascimento Araújo; Marcos Horácio Pereira; Michalis Kotsyfakis; Fabiano Oliveira; Shaden Kamhawi

    2016-01-01

    Blood-feeding insects inject potent salivary components including complement inhibitors into their host's skin to acquire a blood meal. Sand fly saliva was shown to inhibit the classical pathway of complement; however, the molecular identity of the inhibitor remains unknown. Here, we identified SALO as the classical pathway complement inhibitor. SALO, an 11 kDa protein, has no homology to proteins of any other organism apart from New World sand flies. rSALO anti-complement activity has the sa...

  8. European Union funded project on the development of a whole complement deficiency screening ELISA

    DEFF Research Database (Denmark)

    Würzner, Reinhard; Tedesco, Francesco; Garred, Peter

    2015-01-01

    A whole complement ELISA-based assay kit, primarily designed to screen for deficiencies in components of the complement system was developed during a European Union grant involving more than a dozen European scientists and a small-medium enterprise company (Wieslab, which later merged into Eurodi......A whole complement ELISA-based assay kit, primarily designed to screen for deficiencies in components of the complement system was developed during a European Union grant involving more than a dozen European scientists and a small-medium enterprise company (Wieslab, which later merged...

  9. Tuning complement activation and pathway through controlled molecular architecture of dextran chains in nanoparticle corona.

    Science.gov (United States)

    Coty, Jean-Baptiste; Eleamen Oliveira, Elquio; Vauthier, Christine

    2017-11-05

    The understanding of complement activation by nanomaterials is a key to a rational design of safe and efficient nanomedicines. This work proposed a systematic study investigating how molecular design of nanoparticle coronas made of dextran impacts on mechanisms that trigger complement activation. The nanoparticles used for this work consisted of dextran-coated poly(isobutylcyanoacrylate) (PIBCA) nanoparticles have already been thoroughly characterized. Their different capacity to trigger complement activation established on the cleavage of the protein C3 was also already described making these nanoparticles good models to investigate the relation between the molecular feature of their corona and the mechanism by which they triggered complement activation. Results of this new study show that complement activation pathways can be selected by distinct architectures formed by dextran chains composing the nanoparticle corona. Assumptions that explain the relation between complement activation mechanisms triggered by the nanoparticles and the nanoparticle corona molecular feature were proposed. These results are of interest to better understand how the design of dextran-coated nanomaterials will impact interactions with the complement system. It can open perspectives with regard to the selection of a preferential complement activation pathway or prevent the nanoparticles to activate the complement system, based on a rational choice of the corona configuration. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Complementing xeroderma pigmentosum fibroblasts restore biological activity to UV-damaged DNA

    International Nuclear Information System (INIS)

    Day, R.S. III; Kraemer, K.H.; Robbins, J.H.

    1975-01-01

    UV survival curves of adenovirus 2 using fused complementing xeroderma pigmentosum fibroblast strains as virus hosts showed a component with an inactivation slope identical to that given by normal cells. This component was not observed when the fibroblasts were not fused or when fusions involved strains in the same complementing group. Extrapolation to zero dose indicated that three percent of the viral plaque-forming units had infected cells capable of normal repair; this suggested that three percent of the cells were complementing heterokaryons. Thus, heterokaryons formed from xeroderma pigmentosum fibroblasts belonging to different complementation groups are as capable of restoring biological activity to UV-damaged adenovirus 2 as are normal cells

  11. Assembly and activation of alternative complement components on endothelial cell-anchored ultra-large von Willebrand factor links complement and hemostasis-thrombosis.

    Directory of Open Access Journals (Sweden)

    Nancy A Turner

    Full Text Available Vascular endothelial cells (ECs express and release protein components of the complement pathways, as well as secreting and anchoring ultra-large von Willebrand factor (ULVWF multimers in long string-like structures that initiate platelet adhesion during hemostasis and thrombosis. The alternative complement pathway (AP is an important non-antibody-requiring host defense system. Thrombotic microangiopathies can be associated with defective regulation of the AP (atypical hemolytic-uremic syndrome or with inadequate cleavage by ADAMTS-13 of ULVWF multimeric strings secreted by/anchored to ECs (thrombotic thrombocytopenic purpura. Our goal was to determine if EC-anchored ULVWF strings caused the assembly and activation of AP components, thereby linking two essential defense mechanisms.We quantified gene expression of these complement components in cultured human umbilical vein endothelial cells (HUVECs by real-time PCR: C3 and C5; complement factor (CF B, CFD, CFP, CFH and CFI of the AP; and C4 of the classical and lectin (but not alternative complement pathways. We used fluorescent microscopy, monospecific antibodies against complement components, fluorescent secondary antibodies, and the analysis of >150 images to quantify the attachment of HUVEC-released complement proteins to ULVWF strings secreted by, and anchored to, the HUVECs (under conditions of ADAMTS-13 inhibition. We found that HUVEC-released C4 did not attach to ULVWF strings, ruling out activation of the classical and lectin pathways by the strings. In contrast, C3, FB, FD, FP and C5, FH and FI attached to ULVWF strings in quantitative patterns consistent with assembly of the AP components into active complexes. This was verified when non-functional FB blocked the formation of AP C3 convertase complexes (C3bBb on ULVWF strings.AP components are assembled and activated on EC-secreted/anchored ULVWF multimeric strings. Our findings provide one possible molecular mechanism for clinical

  12. Complement factor H protects mice from ischemic acute kidney injury but is not critical for controlling complement activation by glomerular IgM.

    Science.gov (United States)

    Goetz, Lindsey; Laskowski, Jennifer; Renner, Brandon; Pickering, Matthew C; Kulik, Liudmila; Klawitter, Jelena; Stites, Erik; Christians, Uwe; van der Vlag, Johan; Ravichandran, Kameswaran; Holers, V Michael; Thurman, Joshua M

    2018-05-01

    Natural IgM binds to glomerular epitopes in several progressive kidney diseases. Previous work has shown that IgM also binds within the glomerulus after ischemia/reperfusion (I/R) but does not fully activate the complement system. Factor H is a circulating complement regulatory protein, and congenital or acquired deficiency of factor H is a strong risk factor for several types of kidney disease. We hypothesized that factor H controls complement activation by IgM in the kidney after I/R, and that heterozygous factor H deficiency would permit IgM-mediated complement activation and injury at this location. We found that mice with targeted heterozygous deletion of the gene for factor H developed more severe kidney injury after I/R than wild-type controls, as expected, but that complement activation within the glomeruli remained well controlled. Furthermore, mice that are unable to generate soluble IgM were not protected from renal I/R, even in the setting of heterozygous factor H deficiency. These results demonstrate that factor H is important for limiting injury in the kidney after I/R, but it is not critical for controlling complement activation by immunoglobulin within the glomerulus in this setting. IgM binds to glomerular epitopes after I/R, but it is not a significant source of injury. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. SOLARNET: a high resolution mission to complement the ILWS programme

    Science.gov (United States)

    Dame, L.; Clade, S.; Malherbe, J. M.

    SOLARNET is a medium size high resolution solar physics mission proposed to CNES for a new start in 2006 and a possible launch in 2010. Partnerships with Germany, Belgium, China and India are under discussion. At the center of the SOLARNET mission is a 3-telescopes interferometer of 1 meter baseline capable to provide 50 times the best ever spatial resolution achieved in Space with previous, current or even planned solar missions: 20 mas - 20 km on the Sun in the FUV. The interferometer is associated to an on-axis subtractive double monochromator (imaging spectrograph) capable of high spectral (0.01 nm) and high temporal resolutions (50 ms) on a field of view of 40 arcsec and over the FUV and UV spectral domains (from 117.5 to 400 nm). This will allow to access process scales of magnetic reconnection, dissipation, emerging flux and much more, from the high chromosphere to the low corona with emphasis on the transition zone where the magnetic confinement is expected to be maximum. A whole new chapter of the physics of solar magnetic field structuring and evolution will be opened. The interferometer is complemented by several other instruments providing larger field of view and higher temperature (EUV-XUV coronal imaging) to define the context and extension of the solar phenomena. Helioseismology, a strong asset of SOHO, is also intended with both velocity and diameter measures, allowed by a non-eclipsing Sun synchronous orbit. The SOLARNET interferometer design results of an extensive laboratory demonstration program of interferometric imaging of extended objects. It started 10 years ago and culminates this year with the first interferometric observations (images) of the Sun at Meudon Observatory at the "Grand Siderostat de Foucault" with a complete 3 telescopes cophased interferometer representative of SOLARNET. We will review the scientific program of SOLARNET, describe the interferometer concept and design, present the first solar imaging results of the

  14. The small RNA complement of adult Schistosoma haematobium.

    Directory of Open Access Journals (Sweden)

    Andreas J Stroehlein

    2018-05-01

    Full Text Available Blood flukes of the genus Schistosoma cause schistosomiasis-a neglected tropical disease (NTD that affects more than 200 million people worldwide. Studies of schistosome genomes have improved our understanding of the molecular biology of flatworms, but most of them have focused largely on protein-coding genes. Small non-coding RNAs (sncRNAs have been explored in selected schistosome species and are suggested to play essential roles in the post-transcriptional regulation of genes, and in modulating flatworm-host interactions. However, genome-wide small RNA data are currently lacking for key schistosomes including Schistosoma haematobium-the causative agent of urogenital schistosomiasis of humans.MicroRNAs (miRNAs and other sncRNAs of male and female adults of S. haematobium and small RNA transcription levels were explored by deep sequencing, genome mapping and detailed bioinformatic analyses.In total, 89 transcribed miRNAs were identified in S. haematobium-a similar complement to those reported for the congeners S. mansoni and S. japonicum. Of these miRNAs, 34 were novel, with no homologs in other schistosomes. Most miRNAs (n = 64 exhibited sex-biased transcription, suggestive of roles in sexual differentiation, pairing of adult worms and reproductive processes. Of the sncRNAs that were not miRNAs, some related to the spliceosome (n = 21, biogenesis of other RNAs (n = 3 or ribozyme functions (n = 16, whereas most others (n = 3798 were novel ('orphans' with unknown functions.This study provides the first genome-wide sncRNA resource for S. haematobium, extending earlier studies of schistosomes. The present work should facilitate the future curation and experimental validation of sncRNA functions in schistosomes to enhance our understanding of post-transcriptional gene regulation and of the roles that sncRNAs play in schistosome reproduction, development and parasite-host cross-talk.

  15. The small RNA complement of adult Schistosoma haematobium.

    Science.gov (United States)

    Stroehlein, Andreas J; Young, Neil D; Korhonen, Pasi K; Hall, Ross S; Jex, Aaron R; Webster, Bonnie L; Rollinson, David; Brindley, Paul J; Gasser, Robin B

    2018-05-01

    Blood flukes of the genus Schistosoma cause schistosomiasis-a neglected tropical disease (NTD) that affects more than 200 million people worldwide. Studies of schistosome genomes have improved our understanding of the molecular biology of flatworms, but most of them have focused largely on protein-coding genes. Small non-coding RNAs (sncRNAs) have been explored in selected schistosome species and are suggested to play essential roles in the post-transcriptional regulation of genes, and in modulating flatworm-host interactions. However, genome-wide small RNA data are currently lacking for key schistosomes including Schistosoma haematobium-the causative agent of urogenital schistosomiasis of humans. MicroRNAs (miRNAs) and other sncRNAs of male and female adults of S. haematobium and small RNA transcription levels were explored by deep sequencing, genome mapping and detailed bioinformatic analyses. In total, 89 transcribed miRNAs were identified in S. haematobium-a similar complement to those reported for the congeners S. mansoni and S. japonicum. Of these miRNAs, 34 were novel, with no homologs in other schistosomes. Most miRNAs (n = 64) exhibited sex-biased transcription, suggestive of roles in sexual differentiation, pairing of adult worms and reproductive processes. Of the sncRNAs that were not miRNAs, some related to the spliceosome (n = 21), biogenesis of other RNAs (n = 3) or ribozyme functions (n = 16), whereas most others (n = 3798) were novel ('orphans') with unknown functions. This study provides the first genome-wide sncRNA resource for S. haematobium, extending earlier studies of schistosomes. The present work should facilitate the future curation and experimental validation of sncRNA functions in schistosomes to enhance our understanding of post-transcriptional gene regulation and of the roles that sncRNAs play in schistosome reproduction, development and parasite-host cross-talk.

  16. Global Autorecognition and Activation of Complement by Mannan-Binding Lectin in a Mouse Model of Type 1 Diabetes

    Directory of Open Access Journals (Sweden)

    Esben Axelgaard

    2017-01-01

    Full Text Available Increasing evidence links mannan-binding lectin (MBL to late vascular complications of diabetes. MBL is a complement-activating pattern recognition molecule of the innate immune system that can mediate an inflammation response through activation of the lectin pathway. In two recent animal studies, we have shown that autoreactivity of MBL is increased in the kidney in diabetic nephropathy. We hypothesize that long-term exposure to uncontrolled high blood glucose in diabetes may mediate formation of neoepitopes in several tissues and that MBL is able to recognize these structures and thus activate the lectin pathway. To test this hypothesis, we induced diabetes by injection of low-dose streptozotocin in MBL double-knockout (MBL/DKO mice. Development of diabetes was followed by measurements of blood glucose and urine albumin-to-creatinine ratio. Fluorophore-labelled recombinant MBL was injected intravenously in diabetic and nondiabetic mice followed by ex vivo imaging of several organs. We observed that MBL accumulated in the heart, liver, brain, lung, pancreas, and intestines of diabetic mice. We furthermore detected increased systemic complement activation after administration of MBL, thus indicating MBL-mediated systemic complement activation in these animals. These new findings indicate a global role of MBL during late diabetes-mediated vascular complications in various tissues.

  17. Early decrease in total hemolytic complement activity (CH100) after fasting or intestinal bypass in the rat.

    Science.gov (United States)

    Montanari, M; Violi, V; Muri, M; Roncoroni, L; Mora, G; Ronzoni, M

    1986-01-01

    An evaluation of total hemolytic complement activity (CH100) after fasting or intestinal bypass was performed in rats. The experiment lasted 6 days. Three groups, of 5 animals each, were studied. On the 1st day, basal values of total complement (TC), albumin and body weight were determined. Group A received normal, ad libitum feeding, group B started on a 'water only' diet, group C underwent intestinal bypass. On the 4th and 6th day the parameters were assessed. TC mean values were significantly lower in groups B and C, as compared to group A, on the 4th as well as on the 6th day (p less than 0.01 by Mann-Whitney's U test). Body weight showed a similar trend. Differences in albumin were never statistically significant. Limitations of the analytical method are discussed. The data show that fasting or bypass-induced malabsorption may determine an early decrease in total hemolytic complement activity, though a development of an immune deficiency is not proved.

  18. Comparison of serum C3 complement levels between young women ...

    African Journals Online (AJOL)

    Maimun Syukri

    2014-05-29

    May 29, 2014 ... between young women with recurrent urinary tract ... test and Fisher's exact test or t-test as appropriate with data. .... immunosuppressive diseases, use of immunosuppressive drug, ... Serums were removed and stored at А70 °C and used .... Urinary tract infections: new insights into a common problem.

  19. Enhanced CDC of B cell chronic lymphocytic leukemia cells mediated by rituximab combined with a novel anti-complement factor H antibody.

    Directory of Open Access Journals (Sweden)

    Mark T Winkler

    Full Text Available Rituximab therapy for B cell chronic lymphocytic leukemia (B-CLL has met with mixed success. Among several factors to which resistance can be attributed is failure to activate complement dependent cytotoxicity (CDC due to protective complement regulatory proteins, including the soluble regulator complement factor H (CFH. We hypothesized that rituximab killing of non-responsive B-CLL cells could be augmented by a novel human monoclonal antibody against CFH. The B cells from 11 patients with B-CLL were tested ex vivo in CDC assays with combinations of CFH monoclonal antibody, rituximab, and a negative control antibody. CDC of rituximab non-responsive malignant B cells from CLL patients could in some cases be augmented by the CFH monoclonal antibody. Antibody-mediated cytotoxicity of cells was dependent upon functional complement. In one case where B-CLL cells were refractory to CDC by the combination of rituximab plus CFH monoclonal antibody, additionally neutralizing the membrane complement regulatory protein CD59 allowed CDC to occur. Inhibiting CDC regulatory proteins such as CFH holds promise for overcoming resistance to rituximab therapy in B-CLL.

  20. Elevated levels of the complement activation product C4d in bronchial fluids for the diagnosis of lung cancer.

    Directory of Open Access Journals (Sweden)

    Daniel Ajona

    Full Text Available Molecular markers in bronchial fluids may contribute to the diagnosis of lung cancer. We previously observed a significant increase of C4d-containing complement degradation fragments in bronchoalveolar lavage (BAL supernatants from lung cancer patients in a cohort of 50 cases and 22 controls (CUN cohort. The present study was designed to determine the diagnostic performance of these complement fragments (hereinafter jointly referred as C4d in bronchial fluids. C4d levels were determined in BAL supernatants from two independent cohorts: the CU cohort (25 cases and 26 controls and the HUVR cohort (60 cases and 98 controls. A series of spontaneous sputum samples from 68 patients with lung cancer and 10 controls was also used (LCCCIO cohort. Total protein content, complement C4, complement C5a, and CYFRA 21-1 were also measured in all cohorts. C4d levels were significantly increased in BAL samples from lung cancer patients. The area under the ROC curve was 0.82 (95%CI = 0.71-0.94 and 0.67 (95%CI = 0.58-0.76 for the CU and HUVR cohorts, respectively. In addition, unlike the other markers, C4d levels in BAL samples were highly consistent across the CUN, CU and HUVR cohorts. Interestingly, C4d test markedly increased the sensitivity of bronchoscopy in the two cohorts in which cytological data were available (CUN and HUVR cohorts. Finally, in the LCCCIO cohort, C4d levels were higher in sputum supernatants from patients with lung cancer (area under the ROC curve: 0.7; 95%CI = 0.56-0.83. In conclusion, C4d is consistently elevated in bronchial fluids from lung cancer patients and may be used to improve the diagnosis of the disease.

  1. Detection and characterisation of Complement protein activity in bovine milk by bactericidal sequestration assay.

    Science.gov (United States)

    Maye, Susan; Stanton, Catherine; Fitzgerald, Gerald F; Kelly, Philip M

    2015-08-01

    While the Complement protein system in human milk is well characterised, there is little information on its presence and activity in bovine milk. Complement forms part of the innate immune system, hence the importance of its contribution during milk ingestion to the overall defences of the neonate. A bactericidal sequestration assay, featuring a Complement sensitive strain, Escherichia coli 0111, originally used to characterise Complement activity in human milk was successfully applied to freshly drawn bovine milk samples, thus, providing an opportunity to compare Complement activities in both human and bovine milks. Although not identical in response, the levels of Complement activity in bovine milk were found to be closely comparable with that of human milk. Differential counts of Esch. coli 0111 after 2 h incubation were 6.20 and 6.06 log CFU/ml, for raw bovine and human milks, respectively - the lower value representing a stronger Complement response. Exposing bovine milk to a range of thermal treatments e.g. 42, 45, 65, 72, 85 or 95 °C for 10 min, progressively inhibited Complement activity by increasing temperature, thus confirming the heat labile nature of this immune protein system. Low level Complement activity was found, however, in 65 and 72 °C heat treated samples and in retailed pasteurised milk which highlights the outer limit to which high temperature, short time (HTST) industrial thermal processes should be applied if retention of activity is a priority. Concentration of Complement in the fat phase was evident following cream separation, and this was also reflected in the further loss of activity recorded in low fat variants of retailed pasteurised milk. Laboratory-based churning of the cream during simulated buttermaking generated an aqueous (buttermilk) phase with higher levels of Complement activity than the fat phase, thus pointing to a likely association with the milk fat globule membrane (MFGM) layer.

  2. Differences in immunoglobulin subclasses between dye exclusion and 51Cr release complement-dependent lymphocytotoxicity assays

    International Nuclear Information System (INIS)

    McConnachie, P.R.; Denegri, J.F.; Lower, F.E.; Torry, D.S.; McIntyre, J.A.

    1986-01-01

    Paradoxical differences previously noted between lymphocytotoxicity detected by dye exclusion at room temperature (CDCE) or by 51 Cr release (CDC 51 Cr) at 37 0 C in maternal antipaternal complement-dependent lymphocytotoxicity have suggested that CDCE and CDC 51 Cr at 37 0 C, but not at 20 degrees C, may detect different immunological antibody-antigen interactions. Reactions in the two test systems against the same target cells were compared in sera from known immune dialysis patients, secondary aborting women, and refractory platelet recipients before and after heat treatment of sera, absorption with solid-phase heparin, anti-light-chain augmentation, and the addition of murine monoclonal anti-IgG subclass antibodies. The results demonstrate significant differences between the two tests using the same target and sera. Further, the results imply the presence of an inhibitor and an inhibitor of inhibitor in sera. The involvement of different immunoglobulin subclasses was shown in the two tests. These data demonstrate the necessity for further study of the nature of the differences in the mechanisms of these clinically important antibody-detecting systems

  3. Virtual test bench as a complement to study thermal area: application in vapor compression systems

    Directory of Open Access Journals (Sweden)

    Juan Manuel Belman-Flores

    2015-01-01

    Full Text Available Este artículo describe un simulador educativo desarrollado en el software Engineering Equation Solver para representar el comportamiento de un sistema de compresión de vapor. La aplicación está enfocada con propósitos educativos, particularmente para que estudiantes de ingeniería adquieran habilidades en el manejo de instalaciones de refrigeración. Mediante el uso de este simulador, los estudiantes tendrán la capacidad de analizar fácilmente la infl uencia que tienen parámetros medidos experimentalmente (como la velocidad de rotación del compresor, el fl ujo volumétrico y la temperatura de fl uidos secundarios sobre la efi ciencia energética del sistema y sus componentes principales. El banco virtual consta de una pantalla principal que muestra un esquema general del sistema de compresión de vapor con parámetros de entrada y de salida. Desde la pantalla principal, el desempeño de los componentes principales puede ser analizado. Finalmente, este banco de pruebas virtual ha sido probado por estudiantes de ingeniería, concluyendo que el simulador es una herramienta de apoyo que permite mejorar el aprendizaje de las diferentes áreas del conocimiento.

  4. Deficiency of the complement regulator CD59a exacerbates Wallerian degeneration

    NARCIS (Netherlands)

    Ramaglia, Valeria; King, Rosalind Helen Mary; Morgan, Bryan Paul; Baas, Frank

    2009-01-01

    The complement system is implicated in Wallerian degeneration (WD). We have previously shown that the membrane attack complex (MAC) the terminal activation product of the complement cascade, mediates rapid axonal degradation and myelin clearance during WD after peripheral nerve injury. In this study

  5. Complement fixation by solid phase immune complexes. Reduced capacity in SLE sera

    DEFF Research Database (Denmark)

    Baatrup, G; Jonsson, H; Sjöholm, A

    1988-01-01

    We describe an ELISA for assessment of complement function based on the capacity of serum to support fixation of complement components to solid phase immune complexes (IC). Microplates were coated with aggregated bovine serum albumin (BSA) followed by rabbit anti-BSA IgG. The solid phase IC were...

  6. Pseudomonas aeruginosa alkaline protease blocks complement activation via the classical and lectin pathways.

    Science.gov (United States)

    Laarman, Alexander J; Bardoel, Bart W; Ruyken, Maartje; Fernie, Job; Milder, Fin J; van Strijp, Jos A G; Rooijakkers, Suzan H M

    2012-01-01

    The complement system rapidly detects and kills Gram-negative bacteria and supports bacterial killing by phagocytes. However, bacterial pathogens exploit several strategies to evade detection by the complement system. The alkaline protease (AprA) of Pseudomonas aeruginosa has been associated with bacterial virulence and is known to interfere with complement-mediated lysis of erythrocytes, but its exact role in bacterial complement escape is unknown. In this study, we analyzed how AprA interferes with complement activation and whether it could block complement-dependent neutrophil functions. We found that AprA potently blocked phagocytosis and killing of Pseudomonas by human neutrophils. Furthermore, AprA inhibited opsonization of bacteria with C3b and the formation of the chemotactic agent C5a. AprA specifically blocked C3b deposition via the classical and lectin pathways, whereas the alternative pathway was not affected. Serum degradation assays revealed that AprA degrades both human C1s and C2. However, repletion assays demonstrated that the mechanism of action for complement inhibition is cleavage of C2. In summary, we showed that P. aeruginosa AprA interferes with classical and lectin pathway-mediated complement activation via cleavage of C2.

  7. Complement modulation of T cell immune responses during homeostasis and disease.

    Science.gov (United States)

    Clarke, Elizabeth V; Tenner, Andrea J

    2014-11-01

    The complement system is an ancient and critical effector mechanism of the innate immune system as it senses, kills, and clears infectious and/or dangerous particles and alerts the immune system to the presence of the infection and/or danger. Interestingly, an increasing number of reports have demonstrated a clear role for complement in the adaptive immune system as well. Of note, a number of recent studies have identified previously unknown roles for complement proteins, receptors, and regulators in T cell function. Here, we will review recent data demonstrating the influence of complement proteins C1q, C3b/iC3b, C3a (and C3aR), and C5a (and C5aR) and complement regulators DAF (CD55) and CD46 (MCP) on T cell function during homeostasis and disease. Although new concepts are beginning to emerge in the field of complement regulation of T cell function, future experiments should focus on whether complement is interacting directly with the T cell or is having an indirect effect on T cell function via APCs, the cytokine milieu, or downstream complement activation products. Importantly, the identification of the pivotal molecular pathways in the human systems will be beneficial in the translation of concepts derived from model systems to therapeutic targeting for treatment of human disorders. © 2014 Society for Leukocyte Biology.

  8. Complement-mediated tumour growth: implications for cancer nanotechnology and nanomedicines

    DEFF Research Database (Denmark)

    Moghimi, S. M.; Andresen, Thomas Lars

    2009-01-01

    The recent unexpected observation that complement activation helps turnout growth and progression has an important bearing on the future development of cancer nanomedicines for site-specific tumour targeting as these entities are capable of triggering complement. These issues are discussed and su...

  9. The Indicative and Subjunctive "da"-complements in Serbian A Syntactic-Semantic Approach

    Science.gov (United States)

    Todorovic, Natasa

    2012-01-01

    A syntactic-semantic investigation of subjunctive and indicative "da"-complements in Serbian is conducted in this project. After a careful comparison of Serbian sentence constructions with "da"-complements to the equivalent sentence structures in languages of the Balkans as well as other Slavic languages, it is clearly…

  10. Cristina et al., Afr J Tradit Complement Altern Med. (2014) 11(4):48 ...

    African Journals Online (AJOL)

    cadewumi

    Cristina et al., Afr J Tradit Complement Altern Med. (2014) .... New data about the multiple therapeutic valences of this plant will complement the gathered knowledge about the ..... days, on sheep initially treated with 10, 5 and 2%, respectively tincture concentrations, no fed ticks were found, demonstrating the repellent.

  11. SALO, a novel classical pathway complement inhibitor from saliva of the sand fly Lutzomyia longipalpis.

    Science.gov (United States)

    Ferreira, Viviana P; Fazito Vale, Vladimir; Pangburn, Michael K; Abdeladhim, Maha; Mendes-Sousa, Antonio Ferreira; Coutinho-Abreu, Iliano V; Rasouli, Manoochehr; Brandt, Elizabeth A; Meneses, Claudio; Lima, Kolyvan Ferreira; Nascimento Araújo, Ricardo; Pereira, Marcos Horácio; Kotsyfakis, Michalis; Oliveira, Fabiano; Kamhawi, Shaden; Ribeiro, Jose M C; Gontijo, Nelder F; Collin, Nicolas; Valenzuela, Jesus G

    2016-01-13

    Blood-feeding insects inject potent salivary components including complement inhibitors into their host's skin to acquire a blood meal. Sand fly saliva was shown to inhibit the classical pathway of complement; however, the molecular identity of the inhibitor remains unknown. Here, we identified SALO as the classical pathway complement inhibitor. SALO, an 11 kDa protein, has no homology to proteins of any other organism apart from New World sand flies. rSALO anti-complement activity has the same chromatographic properties as the Lu. longipalpis salivary gland homogenate (SGH)counterparts and anti-rSALO antibodies blocked the classical pathway complement activity of rSALO and SGH. Both rSALO and SGH inhibited C4b deposition and cleavage of C4. rSALO, however, did not inhibit the protease activity of C1s nor the enzymatic activity of factor Xa, uPA, thrombin, kallikrein, trypsin and plasmin. Importantly, rSALO did not inhibit the alternative or the lectin pathway of complement. In conclusion our data shows that SALO is a specific classical pathway complement inhibitor present in the saliva of Lu. longipalpis. Importantly, due to its small size and specificity, SALO may offer a therapeutic alternative for complement classical pathway-mediated pathogenic effects in human diseases.

  12. Complement plays a central role in Candida albicans-induced cytokine production by human PBMCs

    DEFF Research Database (Denmark)

    Cheng, Shih-Chin; Sprong, Tom; Joosten, Leo A B

    2012-01-01

    In experimental studies, the role of complement in antifungal host defense has been attributed to its opsonizing capability. In this study, we report that in humans an activated complement system mainly augments Candida albicans-induced host proinflammatory cytokine production via C5a-C5aR signal...

  13. Complement Set Reference after Implicitly Small Quantities: An Event-Related Potentials Study

    Science.gov (United States)

    Ingram, Joanne; Ferguson, Heather J.

    2018-01-01

    An anaphoric reference to the complement-set is a reference to the set that does not fulfil the predicate of the preceding sentence. Preferred reference to the complement-set has been found in eye movements when a character's implicit desire for a high amount has been denied using a negative emotion. We recorded event-related potentials to examine…

  14. Human keratinocytes produce the complement inhibitor factor H: synthesis is regulated by interferon-gamma

    NARCIS (Netherlands)

    Timár, Krisztina K.; Pasch, Marcel C.; van den Bosch, Norbert H. A.; Jarva, Hanna; Junnikkala, Sami; Meri, Seppo; Bos, Jan D.; Asghar, Syed S.

    2006-01-01

    Locally synthesized complement is believed to play an important role in host defense and inflammation at organ level. In the epidermis, keratinocytes have so far been shown to synthesize two complement components, C3 and factor B. Here, we studied the synthesis of factor H by human keratinocytes. We

  15. The C-type lectin of the aggrecan G3 domain activates complement.

    Directory of Open Access Journals (Sweden)

    Camilla Melin Fürst

    Full Text Available Excessive complement activation contributes to joint diseases such as rheumatoid arthritis and osteoarthritis during which cartilage proteins are fragmented and released into the synovial fluid. Some of these proteins and fragments activate complement, which may sustain inflammation. The G3 domain of large cartilage proteoglycan aggrecan interacts with other extracellular matrix proteins, fibulins and tenascins, via its C-type lectin domain (CLD and has important functions in matrix organization. Fragments containing G3 domain are released during normal aggrecan turnover, but increasingly so in disease. We now show that the aggrecan CLD part of the G3 domain activates the classical and to a lesser extent the alternative pathway of complement, via binding of C1q and C3, respectively. The complement control protein (CCP domain adjacent to the CLD showed no effect on complement initiation. The binding of C1q to G3 depended on ionic interactions and was decreased in D2267N mutant G3. However, the observed complement activation was attenuated due to binding of complement inhibitor factor H to CLD and CCP domains. This was most apparent at the level of deposition of terminal complement components. Taken together our observations indicate aggrecan CLD as one factor involved in the sustained inflammation of the joint.

  16. A method for functional trans-complementation of intracellular Francisella tularensis.

    Directory of Open Access Journals (Sweden)

    Shaun Steele

    Full Text Available Francisella tularensis is a highly infectious bacterial pathogen that invades and replicates within numerous host cell types. After uptake, F. tularensis bacteria escape the phagosome, replicate within the cytosol, and suppress cytokine responses. However, the mechanisms employed by F. tularensis to thrive within host cells are mostly unknown. Potential F. tularensis mutants involved in host-pathogen interactions are typically discovered by negative selection screens for intracellular replication or virulence. Mutants that fulfill these criteria fall into two categories: mutants with intrinsic intracellular growth defects and mutants that fail to modify detrimental host cell processes. It is often difficult and time consuming to discriminate between these two possibilities. We devised a method to functionally trans-complement and thus identify mutants that fail to modify the host response. In this assay, host cells are consistently and reproducibly infected with two different F. tularensis strains by physically tethering the bacteria to antibody-coated beads. To examine the efficacy of this protocol, we tested phagosomal escape, cytokine suppression, and intracellular replication for F. tularensis ΔripA and ΔpdpC. ΔripA has an intracellular growth defect that is likely due to an intrinsic defect and fails to suppress IL-1β secretion. In the co-infection model, ΔripA was unable to replicate in the host cell when wild-type bacteria infected the same cell, but cytokine suppression was rescued. Therefore, ΔripA intracellular growth is due to an intrinsic bacterial defect while cytokine secretion results from a failed host-pathogen interaction. Likewise, ΔpdpC is deficient for phagosomal escape, intracellular survival and suppression of IL-1β secretion. Wild-type bacteria that entered through the same phagosome as ΔpdpC rescued all of these phenotypes, indicating that ΔpdpC failed to properly manipulate the host. In summary, functional

  17. Evasion Mechanisms Used by Pathogens to Escape the Lectin Complement Pathway

    DEFF Research Database (Denmark)

    Rosbjerg, Anne; Genster, Ninette; Pilely, Katrine

    2017-01-01

    The complement system is a crucial defensive network that protects the host against invading pathogens. It is part of the innate immune system and can be initiated via three pathways: the lectin, classical and alternative activation pathway. Overall the network compiles a group of recognition...... the level of activity. The result is a pro-inflammatory response meant to combat foreign microbes. Microbial elimination is, however, not a straight forward procedure; pathogens have adapted to their environment by evolving a collection of evasion mechanisms that circumvent the human complement system....... Complement evasion strategies features different ways of exploiting human complement proteins and moreover features different pathogen-derived proteins that interfere with the normal processes. Accumulated, these mechanisms target all three complement activation pathways as well as the final common part...

  18. The Role of Properdin in Zymosan- and Escherichia coli-Induced Complement Activation

    DEFF Research Database (Denmark)

    Harboe, Morten; Garred, Peter; Lindstad, Julie K

    2012-01-01

    Properdin is well known as an enhancer of the alternative complement amplification loop when C3 is activated, whereas its role as a recognition molecule of exogenous pathogen-associated molecular patterns and initiator of complement activation is less understood. We therefore studied the role...... of properdin in activation of complement in normal human serum by zymosan and various Escherichia coli strains. In ELISA, microtiter plates coated with zymosan induced efficient complement activation with deposition of C4b and terminal complement complex on the solid phase. Virtually no deposition of C4b...... cytometry was used to further explore whether properdin acts as an initial recognition molecule reacting directly with zymosan and three E. coli strains. Experiments reported by other authors were made with EGTA Mg(2+) buffer, permitting autoactivation of C3. We found inhibition by compstatin...

  19. Virulence of Group A Streptococci Is Enhanced by Human Complement Inhibitors

    DEFF Research Database (Denmark)

    Ermert, David; Shaughnessy, Jutamas; Joeris, Thorsten

    2015-01-01

    Streptococcus pyogenes, also known as Group A Streptococcus (GAS), is an important human bacterial pathogen that can cause invasive infections. Once it colonizes its exclusively human host, GAS needs to surmount numerous innate immune defense mechanisms, including opsonization by complement and c...... in studies of GAS pathogenesis and for developing vaccines and therapeutics that rely on human complement activation for efficacy.......Streptococcus pyogenes, also known as Group A Streptococcus (GAS), is an important human bacterial pathogen that can cause invasive infections. Once it colonizes its exclusively human host, GAS needs to surmount numerous innate immune defense mechanisms, including opsonization by complement...... and consequent phagocytosis. Several strains of GAS bind to human-specific complement inhibitors, C4b-binding protein (C4BP) and/or Factor H (FH), to curtail complement C3 (a critical opsonin) deposition. This results in diminished activation of phagocytes and clearance of GAS that may lead to the host being...

  20. Soluble and immobilized graphene oxide activates complement system differently dependent on surface oxidation state

    DEFF Research Database (Denmark)

    Wibroe, Peter Popp; Petersen, Søren Vermehren; Bovet, Nicolas Emile

    2016-01-01

    on two related elements of innate immunity: the complement system and interleukin-6 (IL-6) release in human blood. In solution, there was a decrease in GO-mediated complement activation with decreasing surface oxygen content (and altered oxygen functionality), whereas with immobilized GO complement...... response were reversed and increased with decreasing oxygen content. GO solutions, at concentrations below complement activating threshold, did not induce IL-6 release from human blood leukocytes, and further dampened lipopolysaccharide-induced IL-6 release in the whole blood. The latter effect became more...... profound with GO's having higher oxygen content. This protective role of GO solutions, however, disappeared at higher concentrations above complement-activating threshold. We discuss these results in relation to GO surface structure and properties, and implications for local administration and development...

  1. Electroluminescent TCC, C3dg and fB/Bb epitope assays for profiling complement cascade activation in vitro using an activated complement serum calibration standard.

    Science.gov (United States)

    van Vuuren, B Jansen; Bergseth, G; Mollnes, T E; Shaw, A M

    2014-01-15

    Electroluminescent assays for epitopes on the complement components C3dg, terminal complement complex (TCC) and factor B/Bb (fB/Bb) have been developed with capture and detection antibodies to produce detection limits C3dg=91±9ng/mL, TCC=3±0.1ng/mL and fB=55.7±0.1ng/mL. The assay performance was assessed against a series of zymosan and heat aggregated IgG (HAIgG) in vitro activations of complement using a calibrated activated complement serum (ACS) as calibration standard. The ACS standard was stable within 20% accuracy over a 6-month period with freeze-thaw cycles as required. Differential activation of the complement cascade was observed for TCC showing a pseudo-first order formation half-life of 3.5h after activation with zymosan. The C3dg activation fragment indicates a 10% total activation for both activation agents. The kinetic-epitope analysis for fB indicates that the capture epitope is on the fB/Bb protein fragment which can then become covered by the formation of C3bBb or C3bBbP complexes during the time course of the cascade. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Further structural insights into the binding of complement factor H by complement regulator-acquiring surface protein 1 (CspA) of Borrelia burgdorferi

    International Nuclear Information System (INIS)

    Caesar, Joseph J. E.; Wallich, Reinhard; Kraiczy, Peter; Zipfel, Peter F.; Lea, Susan M.

    2013-01-01

    B. burgdorferi binds complement factor H using a dimeric surface protein, CspA (BbCRASP-1). Presented here is a new structure of CspA that suggests that there is a degree of flexibility between subunits which may have implications for complement regulator binding. Borrelia burgdorferi has evolved many mechanisms of evading the different immune systems across its range of reservoir hosts, including the capture and presentation of host complement regulators factor H and factor H-like protein-1 (FHL-1). Acquisition is mediated by a family of complement regulator-acquiring surface proteins (CRASPs), of which the atomic structure of CspA (BbCRASP-1) is known and shows the formation of a homodimeric species which is required for binding. Mutagenesis studies have mapped a putative factor H binding site to a cleft between the two subunits. Presented here is a new atomic structure of CspA which shows a degree of flexibility between the subunits which may be critical for factor H scavenging by increasing access to the binding interface and allows the possibility that the assembly can clamp around the bound complement regulators

  3. Activity and activation of the complement system in patients being operated on for cancer of the colon

    DEFF Research Database (Denmark)

    Baatrup, G; Qvist, N; Junker, A

    1994-01-01

    OBJECTIVE: To find out if there was any local activation of complement in the vicinity of a colonic cancer, and any fluctuation in the function of the complement system during operation. DESIGN: Prospective study. SETTING: One university and two district hospitals in Denmark. SUBJECTS: 29 selected...... patients undergoing emergency and elective operations for colonic cancer. INTERVENTIONS: Measurements of systemic and local complement fixation capacity and complement activation in samples of serum or plasma taken before, during, and after operation. MAIN OUTCOME MEASURES: Changes in complement fixation...... capacity and complement activation during operation. RESULTS: Haemodilution during operation caused a significant reduction in the complement fixation capacity of serum and in the activation of the complement system as measured by generation of C3c. We were unable to confirm the presence of complement...

  4. Complement or Contamination: A Study of the Validity of Multiple-Choice Items when Assessing Reasoning Skills in Physics

    OpenAIRE

    Anders Jönsson; David Rosenlund; Fredrik Alvén

    2017-01-01

    The purpose of this study is to investigate the validity of using multiple-choice (MC) items as a complement to constructed-response (CR) items when making decisions about student performance on reasoning tasks. CR items from a national test in physics have been reformulated into MC items and students’ reasoning skills have been analyzed in two substudies. In the first study, 12 students answered the MC items and were asked to explain their answers orally. In the second study, 102 students fr...

  5. Conglutinin exhibits a complement-dependent enhancement of the respiratory burst of phagocytes stimulated by E. coli

    DEFF Research Database (Denmark)

    Friis, P; Svehag, S E; Andersen, Ove

    1991-01-01

    . Conglutinin enhances, in a dose-dependent manner, the respiratory burst of spleen cells stimulated with serum-opsonized Escherichia coli. The enhancement was only demonstrable in the presence of a functional complement system. The conglutinin-mediated enhancement of the respiratory burst was inhibited......Conglutinin is a mammalian C-type lectin which shows anti-bacterial activity when tested in vivo and in vitro. This study concerns the effect of conglutinin on the respiratory burst of murine spleen cells, using a chemiluminescence assay for measurement of generated reactive oxygen metabolites...

  6. The prozone effect exerted by the complement-binding anti-Lea on anti-D.

    Science.gov (United States)

    Joshi, Sanmukh R; Parekh, Kamlesh H

    2017-01-01

    Prozone phenomenon is seen with very high-titer antibodies in an immune serum. The prozone effect on anti-D by a low-titer anti-Le a was investigated associated with neonatal jaundice. Standard methods were used in investigations. The child was born at full-term developed mild jaundice. With weak direct antiglobulin test+, her indirect serum bilirubin was progressed to 27.5 mg/dL in 48 h. Anti-D and anti-Le a were detected in the mother. Both these antibodies were detected in the child's serum though the eluate from red blood cells (RBCs) contained only anti-D. Mother's anti-D was masked by anti-Le a if the RBCs possessed both the antigens together. Anti-D was revealed only with D-positive RBCs lacking Le a or if the serum was modified by mixing with Le a+ saliva or was heated at 56°C or fortified with citrate solution. An anti-D showed prozone effect exerted by the complement-fixing anti-Le a in the test.

  7. Rivaroxaban limits complement activation compared with warfarin in antiphospholipid syndrome patients with venous thromboembolism.

    Science.gov (United States)

    Arachchillage, D R J; Mackie, I J; Efthymiou, M; Chitolie, A; Hunt, B J; Isenberg, D A; Khamashta, M; Machin, S J; Cohen, H

    2016-11-01

    Essentials Complement activation has a pathogenic role in thrombotic antiphospholipid syndrome (APS). Coagulation proteases such as factor Xa can activate complement proteins. Complement activation markers were elevated in anticoagulated thrombotic APS patients. Complement activation decreased in APS patients switching from warfarin to rivaroxaban. Background Complement activation may play a major role in the pathogenesis of thrombotic antiphospholipid syndrome (APS). Coagulation proteases such as factor Xa can activate complement proteins. Aims To establish whether rivaroxaban, a direct factor Xa inhibitor, limits complement activation compared with warfarin in APS patients with previous venous thromboembolism (VTE). Methods A total of 111 APS patients with previous VTE, on warfarin target INR 2.5, had blood samples taken at baseline and at day 42 after randomization in the RAPS (Rivaroxaban in Antiphospholipid Syndrome) trial. Fifty-six patients remained on warfarin and 55 switched to rivaroxaban. Fifty-five normal controls (NC) were also studied. Markers of complement activation (C3a, C5a, terminal complement complex [SC5b-9] and Bb fragment) were assessed. Results APS patients had significantly higher complement activation markers compared with NC at both time-points irrespective of the anticoagulant. There were no differences between the two patient groups at baseline, or patients remaining on warfarin at day 42. In 55 patients randomized to rivaroxaban, C3a, C5a and SC5b-9 were lower at day 42 (median (ng mL -1 ) [confidence interval] 64 [29-125] vs. 83 [35-147], 9 [2-15] vs. 12 [4-18] and 171 [56-245] vs. 201 [66-350], respectively) but levels of Bb fragment were unchanged. There were no correlations between rivaroxaban levels and complement activation markers. Conclusions APS patients with previous VTE on warfarin exhibit increased complement activation, which is likely to occur via the classical pathway and is decreased by rivaroxaban administration

  8. Complement activation as a bioequivalence issue relevant to the development of generic liposomes and other nanoparticulate drugs

    International Nuclear Information System (INIS)

    Szebeni, Janos; Storm, Gert

    2015-01-01

    Liposomes are known to activate the complement (C) system, which can lead in vivo to a hypersensitivity syndrome called C activation-related pseudoallergy (CARPA). CARPA has been getting increasing attention as a safety risk of i.v. therapy with liposomes, whose testing is now recommended in bioequivalence evaluations of generic liposomal drug candidates. This review highlights the adverse consequences of C activation, the unique symptoms of CARPA triggered by essentially all i.v. administered liposomal drugs, and the various features of vesicles influencing this adverse immune effect. For the case of Doxil, we also address the mechanism of C activation and the opsonization vs. long circulation (stealth) paradox. In reviewing the methods of assessing C activation and CARPA, we delineate the most sensitive porcine model and an algorithm for stepwise evaluation of the CARPA risk of i.v. liposomes, which are proposed for standardization for preclinical toxicology evaluation of liposomal and other nanoparticulate drug candidates. - Highlights: • Outlining of difficulties in generic development of liposomal drugs. • New regulatory requirements to evaluate CARPA in preclinical studies. • Review of complement activation by liposomes and its adverse consequences (CARPA). • Assays of C activation in vitro and CARPA in vivo, with the porcine test in focus. • Decision tree how to handle the risk of CARPA assessed by a battery of tests.

  9. Complement activation as a bioequivalence issue relevant to the development of generic liposomes and other nanoparticulate drugs

    Energy Technology Data Exchange (ETDEWEB)

    Szebeni, Janos, E-mail: jszebeni2@gmail.com [Nanomedicine Research and Education Center, Semmelweis University, Budapest & SeroScience Ltd, Budapest (Hungary); Storm, Gert [Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences (UIPS), Utrecht University, Utrecht (Netherlands)

    2015-12-18

    Liposomes are known to activate the complement (C) system, which can lead in vivo to a hypersensitivity syndrome called C activation-related pseudoallergy (CARPA). CARPA has been getting increasing attention as a safety risk of i.v. therapy with liposomes, whose testing is now recommended in bioequivalence evaluations of generic liposomal drug candidates. This review highlights the adverse consequences of C activation, the unique symptoms of CARPA triggered by essentially all i.v. administered liposomal drugs, and the various features of vesicles influencing this adverse immune effect. For the case of Doxil, we also address the mechanism of C activation and the opsonization vs. long circulation (stealth) paradox. In reviewing the methods of assessing C activation and CARPA, we delineate the most sensitive porcine model and an algorithm for stepwise evaluation of the CARPA risk of i.v. liposomes, which are proposed for standardization for preclinical toxicology evaluation of liposomal and other nanoparticulate drug candidates. - Highlights: • Outlining of difficulties in generic development of liposomal drugs. • New regulatory requirements to evaluate CARPA in preclinical studies. • Review of complement activation by liposomes and its adverse consequences (CARPA). • Assays of C activation in vitro and CARPA in vivo, with the porcine test in focus. • Decision tree how to handle the risk of CARPA assessed by a battery of tests.

  10. Lack of evidence from studies of soluble protein fragments that Knops blood group polymorphisms in complement receptor-type 1 are driven by malaria.

    Directory of Open Access Journals (Sweden)

    Patience B Tetteh-Quarcoo

    Full Text Available Complement receptor-type 1 (CR1, CD35 is the immune-adherence receptor, a complement regulator, and an erythroid receptor for Plasmodium falciparum during merozoite invasion and subsequent rosette formation involving parasitized and non-infected erythrocytes. The non-uniform geographical distribution of Knops blood group CR1 alleles Sl1/2 and McC(a/b may result from selective pressures exerted by differential exposure to infectious hazards. Here, four variant short recombinant versions of CR1 were produced and analyzed, focusing on complement control protein modules (CCPs 15-25 of its ectodomain. These eleven modules encompass a region (CCPs 15-17 key to rosetting, opsonin recognition and complement regulation, as well as the Knops blood group polymorphisms in CCPs 24-25. All four CR1 15-25 variants were monomeric and had similar axial ratios. Modules 21 and 22, despite their double-length inter-modular linker, did not lie side-by-side so as to stabilize a bent-back architecture that would facilitate cooperation between key functional modules and Knops blood group antigens. Indeed, the four CR1 15-25 variants had virtually indistinguishable affinities for immobilized complement fragments C3b (K(D = 0.8-1.1 µM and C4b (K(D = 5.0-5.3 µM. They were all equally good co-factors for factor I-catalysed cleavage of C3b and C4b, and they bound equally within a narrow affinity range, to immobilized C1q. No differences between the variants were observed in assays for inhibition of erythrocyte invasion by P. falciparum or for rosette disruption. Neither differences in complement-regulatory functionality, nor interactions with P. falciparum proteins tested here, appear to have driven the non-uniform geographic distribution of these alleles.

  11. The stability of complement-mediated bactericidal activity in human serum against Salmonella.

    Directory of Open Access Journals (Sweden)

    Colette M O'Shaughnessy

    Full Text Available The complement cascade includes heat-labile proteins and care is required when handling serum in order to preserve its functional integrity. We have previously used a whole human serum bactericidal assay to show that antibody and an intact complement system are required in blood for killing of invasive isolates of Salmonella. The aim of the present study was to evaluate the conditions under which human serum can be stored and manipulated while maintaining complement integrity. Serum bactericidal activity against Salmonella was maintained for a minimum of 35 days when stored at 4°C, eight days at 22°C and 54 hours at 37°C. Up to three freeze-thaw cycles had no effect on the persistence of bactericidal activity and hemolytic complement assays confirmed no effect on complement function. Delay in the separation of serum for up to four days from clotted blood stored at 22°C did not affect bactericidal activity. Dilution of serum resulted in an increased rate of loss of bactericidal activity and so serum should be stored undiluted. These findings indicate that the current guidelines concerning manipulation and storage of human serum to preserve complement integrity and function leave a large margin for safety with regards to bactericidal activity against Salmonella. The study provides a scheme for determining the requirements for serum handling in relation to functional activity of complement in other systems.

  12. Protective function of complement against alcohol-induced rat liver damage.

    Science.gov (United States)

    Bykov, Igor L; Väkevä, Antti; Järveläinen, Harri A; Meri, Seppo; Lindros, Kai O

    2004-11-01

    The complement system can promote tissue damage or play a homeostatic role in the clearance and disposal of damaged tissue. We assessed the role of the terminal complement pathway in alcohol-induced liver damage in complement C6 (C6-/-) genetically deficient rats. C6-/- and corresponding C6+/+ rats were continuously exposed to ethanol by feeding ethanol-supplemented liquid diet for six weeks. Liver samples were analyzed for histopathology and complement component deposition by immunofluorescence microscopy. Prostaglandin E receptors and cytokine mRNA levels were analyzed by RT-PCR and plasma cytokines by ELISA. Deposition of complement components C1, C3, C8 and C9 was observed in C6+/+ rats, but not in C6-/- animals. The histopathological changes, the liver weight increase and the elevation of the plasma pro-/anti-inflammatory TNF-alpha/IL-10 ratio were, on the other hand, more marked in C6-/- rats. Furthermore, ethanol enhanced the hepatic mRNA expression of the prostaglandin E receptors EP2R and EP4R exclusively in the C6-/- rats. Our results indicate that a deficient terminal complement pathway predisposes to tissue injury and promotes a pro-inflammatory cytokine response. This suggests that an intact complement system has a protective function in the development of alcoholic liver damage.

  13. Activation of the classical pathway of complement by tobacco glycoprotein (TGP).

    Science.gov (United States)

    Koethe, S M; Nelson, K E; Becker, C G

    1995-07-15

    Tobacco glycoprotein (TGP), a polyphenol-rich glycoprotein isolated from tobacco leaves, activates the classical complement pathway through a mechanism that appears to involve direct interaction with C1q. A binding site on C1q for TGP can be localized by competitive inhibition with DNA to a region located in the junction between the collagen-like and globular regions of the molecule. A protein with activity similar to TGP has also been isolated from cigarette smoke condensate (TGP-S); it shares a binding site on C1q with TGP and has similar functional activity, with the exception that complement activation does not proceed to formation of a C3 cleaving enzyme. The ability of TGP and TGP-S to activate complement can be partially duplicated using polyphenols associated with tobacco leaf and smoke, i.e., chlorogenic acid and rutin. These polyphenols also compete with TGP for a binding site on immobilized C1q, suggesting that the polyphenol portion of TGP is critical for activation of complement. These results provide an additional mechanism for complement activation by cigarette products that, in vivo, could result in a localized complement depletion, generation of biologically active complement cleavage products, and initiation of an inflammatory response.

  14. Breaking down the complement system: a review and update on novel therapies.

    Science.gov (United States)

    Reddy, Yuvaram N V; Siedlecki, Andrew M; Francis, Jean M

    2017-03-01

    The complement system represents one of the more primitive forms of innate immunity. It has increasingly been found to contribute to pathologies in the native and transplanted kidney. We provide a concise review of the physiology of the complement cascade, and discuss current and upcoming complement-based therapies. Current agents in clinical use either bind to complement components directly or prevent complement from binding to antibodies affixed to the endothelial surface. These include C1 esterase inhibitors, anti-C5 mAbs, anti-CD20 mAbs, and proteasome inhibitors. Treatment continues to show efficacy in the atypical hemolytic uremic syndrome and antibody-mediated rejection. Promising agents not currently available include CCX168, TP10, AMY-101, factor D inhibitors, coversin, and compstatin. Several new trials are targeting complement inhibition to treat antineutrophilic cystoplasmic antibody (ANCA)-associated vasculitis, C3 glomerulopathy, thrombotic microangiopathy, and IgA nephropathy. New agents for the treatment of the atypical hemolytic uremic syndrome are also in development. Complement-based therapies are being considered for targeted therapy in the atypical hemolytic uremic syndrome and antibody-mediated rejection, C3 glomerulopathy, and ANCA-associated vasculitis. A few agents are currently in use as orphan drugs. A number of other drugs are in clinical trials and, overall, are showing promising preliminary results.

  15. Guilty as charged: all available evidence implicates complement's role in fetal demise.

    Science.gov (United States)

    Girardi, Guillermina

    2008-03-01

    Appropriate complement inhibition is an absolute requirement for normal pregancy. Uncontrolled complement activation in the maternal-fetal interface leads to fetal death. Here we show that complement activation is a crucial and early mediator of pregnancy loss in two different mouse models of pregnancy loss. Using a mouse model of fetal loss and growth restriction (IUGR) induced by antiphospholipid antibodies (aPL), we examined the role of complement activation in fetal loss and IUGR. We found that C5a-C5aR interaction and neutrophils are key mediators of fetal injury. Treatment with heparin, the standard therapy for pregnant patients with aPL, prevents complement activation and protects mice from pregnancy complications induced by aPL, and anticoagulants that do not inhibit complement do not protect pregnancies. In an antibody-independent mouse model of spontaneous miscarriage and IUGR (CBA/JxDBA/2) we also identified C5a as an essential mediator. Complement activation caused dysregulation of the angiogenic factors required for normal placental development. In CBA/JxDBA/2 mice, we observed inflammatory infiltrates in placentas, functional deficiency of free vascular endothelial growth factor (VEGF), elevated levels of soluble VEGF receptor-1 (sVEGFR-1, also known as sFlt-1; a potent anti-angiogenic molecule), and defective placental development. Inhibition of complement activation blocked the increase in sVEGFR-1 and rescued pregnancies. Our studies in antibody-dependent and antibody-independent models of pregnancy complications identified complement activation as the key mediator of damage and will allow development of new interventions to prevent pregnancy loss and IUGR.

  16. Complement is activated in progressive multiple sclerosis cortical grey matter lesions.

    Science.gov (United States)

    Watkins, Lewis M; Neal, James W; Loveless, Sam; Michailidou, Iliana; Ramaglia, Valeria; Rees, Mark I; Reynolds, Richard; Robertson, Neil P; Morgan, B Paul; Howell, Owain W

    2016-06-22

    The symptoms of multiple sclerosis (MS) are caused by damage to myelin and nerve cells in the brain and spinal cord. Inflammation is tightly linked with neurodegeneration, and it is the accumulation of neurodegeneration that underlies increasing neurological disability in progressive MS. Determining pathological mechanisms at play in MS grey matter is therefore a key to our understanding of disease progression. We analysed complement expression and activation by immunocytochemistry and in situ hybridisation in frozen or formalin-fixed paraffin-embedded post-mortem tissue blocks from 22 progressive MS cases and made comparisons to inflammatory central nervous system disease and non-neurological disease controls. Expression of the transcript for C1qA was noted in neurons and the activation fragment and opsonin C3b-labelled neurons and glia in the MS cortical and deep grey matter. The density of immunostained cells positive for the classical complement pathway protein C1q and the alternative complement pathway activation fragment Bb was significantly increased in cortical grey matter lesions in comparison to control grey matter. The number of cells immunostained for the membrane attack complex was elevated in cortical lesions, indicating complement activation to completion. The numbers of classical (C1-inhibitor) and alternative (factor H) pathway regulator-positive cells were unchanged between MS and controls, whilst complement anaphylatoxin receptor-bearing microglia in the MS cortex were found closely apposed to cortical neurons. Complement immunopositive neurons displayed an altered nuclear morphology, indicative of cell stress/damage, supporting our finding of significant neurodegeneration in cortical grey matter lesions. Complement is activated in the MS cortical grey matter lesions in areas of elevated numbers of complement receptor-positive microglia and suggests that complement over-activation may contribute to the worsening pathology that underlies the

  17. Dissociable effects of Sry and sex chromosome complement on activity, feeding and anxiety-related behaviours in mice.

    Science.gov (United States)

    Kopsida, Eleni; Lynn, Phoebe M; Humby, Trevor; Wilkinson, Lawrence S; Davies, William

    2013-01-01

    Whilst gonadal hormones can substantially influence sexual differentiation of the brain, recent findings have suggested that sex-linked genes may also directly influence neurodevelopment. Here we used the well-established murine 'four core genotype' (FCG) model on a gonadally-intact, outbred genetic background to characterise the contribution of Sry-dependent effects (i.e. those arising from the expression of the Y-linked Sry gene in the brain, or from hormonal sequelae of gonadal Sry expression) and direct effects of sex-linked genes other than Sry ('sex chromosome complement' effects) to sexually dimorphic mouse behavioural phenotypes. Over a 24 hour period, XX and XY gonadally female mice (lacking Sry) exhibited greater horizontal locomotor activity and reduced food consumption per unit bodyweight than XX and XY gonadally male mice (possessing Sry); in two behavioural tests (the elevated plus and zero mazes) XX and XY gonadally female mice showed evidence for increased anxiety-related behaviours relative to XX and XY gonadally male mice. Exploratory correlational analyses indicated that these Sry-dependent effects could not be simply explained by brain expression of the gene, nor by circulating testosterone levels. We also noted a sex chromosome complement effect on food (but not water) consumption whereby XY mice consumed more over a 24hr period than XX mice, and a sex chromosome complement effect in a third test of anxiety-related behaviour, the light-dark box. The present data suggest that: i) the male-specific factor Sry may influence activity and feeding behaviours in mice, and ii) dissociable feeding and anxiety-related murine phenotypes may be differentially modulated by Sry and by other sex-linked genes. Our results may have relevance for understanding the molecular underpinnings of sexually dimorphic behavioural phenotypes in healthy men and women, and in individuals with abnormal sex chromosome constitutions.

  18. Dissociable effects of Sry and sex chromosome complement on activity, feeding and anxiety-related behaviours in mice.

    Directory of Open Access Journals (Sweden)

    Eleni Kopsida

    Full Text Available Whilst gonadal hormones can substantially influence sexual differentiation of the brain, recent findings have suggested that sex-linked genes may also directly influence neurodevelopment. Here we used the well-established murine 'four core genotype' (FCG model on a gonadally-intact, outbred genetic background to characterise the contribution of Sry-dependent effects (i.e. those arising from the expression of the Y-linked Sry gene in the brain, or from hormonal sequelae of gonadal Sry expression and direct effects of sex-linked genes other than Sry ('sex chromosome complement' effects to sexually dimorphic mouse behavioural phenotypes. Over a 24 hour period, XX and XY gonadally female mice (lacking Sry exhibited greater horizontal locomotor activity and reduced food consumption per unit bodyweight than XX and XY gonadally male mice (possessing Sry; in two behavioural tests (the elevated plus and zero mazes XX and XY gonadally female mice showed evidence for increased anxiety-related behaviours relative to XX and XY gonadally male mice. Exploratory correlational analyses indicated that these Sry-dependent effects could not be simply explained by brain expression of the gene, nor by circulating testosterone levels. We also noted a sex chromosome complement effect on food (but not water consumption whereby XY mice consumed more over a 24hr period than XX mice, and a sex chromosome complement effect in a third test of anxiety-related behaviour, the light-dark box. The present data suggest that: i the male-specific factor Sry may influence activity and feeding behaviours in mice, and ii dissociable feeding and anxiety-related murine phenotypes may be differentially modulated by Sry and by other sex-linked genes. Our results may have relevance for understanding the molecular underpinnings of sexually dimorphic behavioural phenotypes in healthy men and women, and in individuals with abnormal sex chromosome constitutions.

  19. Invisible anti-cloak with elliptic cross section using phase complement

    International Nuclear Information System (INIS)

    Yang Yu-Qi; Zhang Min; Yue Jian-Xiang

    2011-01-01

    Based on the theory of phase complement, an anti-cloak with circular cross section can be made invisible to an object outside its domain. As the cloak with elliptic cross section is more effective to make objects invisible than that with circular cross section, a scaled coordinate system is proposed to design equivalent materials of invisible anti-cloak with elliptic cross section using phase complement. The cloaks with conventional dielectric and double negative parameters are both simulated with the geometrical transformations. The results show that the cloak with elliptic cross section through phase complement can effectively hide the outside objects. (classical areas of phenomenology)

  20. Structural insight into the recognition of complement C3 activation products by integrin receptors

    DEFF Research Database (Denmark)

    Bajic, Goran

    2015-01-01

    fragment C3a called anaphylatoxin. Complement leads to opsonization as the proteolytic fragment C3b becomes covalently linked to the activator surface through a reactive thioester. Self-surfaces are protected by complement regulators, whereas complement activation vividly amplifies on pathogens...... and their clearance by dendritic cells is mediated by αMβ2. The central molecule in my project, αMβ2 integrin, recognizes many diverse ligands including iC3b, but the molecular basis for such recognition was lacking. During my PhD I have obtained a major breakthrough in the dissection of iC3b interaction with αMβ2. I...