Methyl Parathion Masks Withdrawal from Physical Dependence on Morphine

OpenAIRE

Zhu, Hong; Ho, Ing K.; Kramer, Robert E.; Baker, Rodney C.; Rockhold, Robin W.

2002-01-01

Abstract: The cholinergic system has been proposed to participate in the development of dependence on opioids. The present study examined effects of dermal pretreatment with methyl parathion (MP), an acetylcholinesterase inhibitor, on the development of physical dependence on morphine. Opioid dependence was induced by continuous intracerebroventricular (i.c.v.) infusion of morphine (26 nmol/μl/h) for 3 days in adult male Sprague-Dawley rats. Each rat received two doses of MP, 12.5 mg/kg, d...

Photocatalytic degradation of Acephate, Omethoate, and Methyl parathion by Fe_3O_4@SiO_2@mTiO_2 nanomicrospheres

International Nuclear Information System (INIS)

Zheng, Lingling; Pi, Fuwei; Wang, Yifan; Xu, Hui; Zhang, Yinzhi; Sun, Xiulan

2016-01-01

Highlights: • An efficient photocatalyst Fe_3O_4@SiO_2@mTiO_2 with high magnetic response and large specific surface area was synthesized. • Photocatalytic efficiency of Fe_3O_4@SiO_2@mTiO_2 on Acephate, Omethoate, and Methyl Parathion was higher than TiO_2 P-25. • Possible photocatalytic degradation mechanisms for the Acephate, Omethoate, and Methyl Parathion were proposed. - Abstract: A novel magnetic mesoporous nanomicrospheres Fe_3O_4@SiO_2@mTiO_2 were synthetized and characterized by a series of techniques including FE-TEM, EDS, FE-SEM, PXRD, XPS, BET, TGA as well as VSM, and subsequently tested as a photocatalyst for the degradation of Acephate, Omethoate, and Methyl parathion under UV irradiation. The well-designed nanomicrospheres exhibit a pure and highly crystalline anatase TiO_2 layer, large specific surface area, and high-magnetic-response. Photocatalytic degradation of the three organophosphorus pesticides (OPPs) and the formation intermediates were identified using HPLC, TOC-V_c_p_n, IC, pH meter and GC–MS. Acephate, Omethoate, and Methyl parathion disappeared after 45 min, 45 min, and 80 min UV illumination, respectively. At the end of the treatment, the total organic carbon (TOC) of the OPPs was reduced 80–85%. The main mineralization products were SO_4"2"−, NO_3"− and PO_4"3"− and Omethoate additionally formed NO_2"−. Based on the results, we proposed the photocatalytic degradation pathways for Acephate, Omethoate, and Methyl parathion.

Covalent Coupling of Organophosphorus Hydrolase Loaded Quantum Dots to Carbon Nanotube/Au Nanocomposite for Enhanced Detection of Methyl Parathion

Energy Technology Data Exchange (ETDEWEB)

Du, Dan; Chen, Wenjuan; Zhang, Weiying; Liu, Deli; Li, Haibing; Lin, Yuehe

2010-02-15

An amperometric biosensor for highly selective and sensitive determination of methyl parathion (MP) was developed based on dual signal amplification: (1) a large amount of introduced enzyme on the electrode surface and (2) synergistic effects of nanoparticles towards enzymatic catalysis. The fabrication process includes (1) electrochemical deposition of gold nanoparticles by a multi-potential step technique at multiwalled carbon nanotube (MWCNT) film pre-cast on a glassy carbon electrode and (2) immobilization of methyl parathion degrading enzyme (MPDE) onto a modified electrode through CdTe quantum dots (CdTe QDs) covalent attachment. The introduced MWCNT and gold nanoparticles significantly increased the surface area and exhibited synergistic effects towards enzymatic catalysis. CdTe QDs are further used as carriers to load a large amount of enzyme. As a result of these two important enhancement factors, the proposed biosensor exhibited extremely sensitive, perfectly selective, and rapid response to methyl parathion in the absence of a mediator.

Toxicity of sodium chloride and methyl parathion on the macrophyte Lemna minor (Linnaeus, 1753 with respect to frond number and chlorophyll

Directory of Open Access Journals (Sweden)

Erlei Cassiano Keppeler

2009-09-01

Full Text Available Duckweed, Lemna minor L., is a suitable plant model for toxicity evaluation of many contaminants due to its small size and rapid growth. Methyl parathion is a toxic compound which is utilized to eliminate aquatic insect larvae, among other purposes. Its toxicity was evaluated with the use of L. minor in this study. Methyl parathion was added to Hoagland’s nutrient medium at concentrations of 0, 8, 16, 22, 28 and 32mg.L–1. Lemna minor is used as a tool in evaluating chemical test products for toxic effects. The sensitivity of Lemna to sodium chloride, the reference substance, at concentrations of 0, 2, 4, 6, 7 and 8 g.L–1, was determined for comparison and resulted in an IC50 of 6.87g.L–1. Methyl parathion in L. minor showed an IC50 of 49.48mg.L–1.

Optimization of Fenton oxidation for the removal of methyl parathion in aqueous solution

Directory of Open Access Journals (Sweden)

Roli Saini

2016-09-01

Full Text Available In the present study, for the treatment of methyl parathion, Fenton oxidation is adopted. The aims of this study were (a to assess the removal efficiency in terms of chemical oxygen demand (COD, (b to scrutinize the influence of different parameters: initial pH, concentrations of H2O2 and Fe2+ and, (c response surface methodology (RSM was used to design the Fenton process. Three-level central composite design (CCD was applied in designing the experiments to observe the effects of most important operating factors. The enactment of the model was judged with the analysis of variance (ANOVA. A quadratic model was used to represent the experimental data. The predicted values and experimental values were found to be in good agreement with the (R2 = 0.9891 and Adj-R2 = 0.9877, which define the propriety of the model. The characteristic of methyl parathion bearing wastewater was concentration 30 mg/L, COD 440 mg/L, pH 6.5. Maximum removal efficiency was perceived at acidic pH value 3.

Toxicity of sodium chloride and methyl parathion on the macrophyte Lemna minor (Linnaeus, 1753 with respect to frond number and chlorophyll

Directory of Open Access Journals (Sweden)

Erlei Cassiano Keppeler

2009-06-01

Full Text Available http://dx.doi.org/10.5007/2175-7925.2009v22n3p27 Duckweed, Lemna minor L., is a suitable plant model for toxicity evaluation of many contaminants due to its small size and rapid growth. Methyl parathion is a toxic compound which is utilized to eliminate aquatic insect larvae, among other purposes. Its toxicity was evaluated with the use of L. minor in this study. Methyl parathion was added to Hoagland’s nutrient medium at concentrations of 0, 8, 16, 22, 28 and 32mg.L–1. Lemna minor is used as a tool in evaluating chemical test products for toxic effects. The sensitivity of Lemna to sodium chloride, the reference substance, at concentrations of 0, 2, 4, 6, 7 and 8 g.L–1, was determined for comparison and resulted in an IC50 of 6.87g.L–1. Methyl parathion in L. minor showed an IC50 of 49.48mg.L–1.

75 FR 22402 - Methyl Parathion; Notice of Receipt of Request to Voluntarily Cancel Pesticide Registrations

Science.gov (United States)

2010-04-28

... Receipt of Request to Voluntarily Cancel Pesticide Registrations AGENCY: Environmental Protection Agency... registrants to voluntarily cancel their registrations of products containing the pesticide methyl parathion... will be permitted after the registration has been cancelled only if such sale, distribution, or use is...

Preparation of acryloyl β-cyclodextrin-silica hybrid monolithic column and its application in pipette tip solid-phase extraction and HPLC analysis of methyl parathion and fenthion.

Science.gov (United States)

Chen, Ling; Dang, Xueping; Ai, Youhong; Chen, Huaixia

2018-05-07

An acryloyl β-cyclodextrin-silica hybrid monolithic column for pipette tip solid-phase extraction and high-performance liquid chromatography determination of methyl parathion and fenthion have been prepared through a sol-gel polymerization method. The synthesis conditions, including the volume of cross-linker and the ratio of inorganic solution to organic solution, were optimized. The prepared monolithic column was characterized by thermogravimetric analysis, scanning electron microscopy and Fourier transform infrared spectroscopy. The eluent type, volume and flow rate, sample volume, flow rate, acidity and ionic strength were optimized in detail. Under the optimized conditions, a simple and sensitive pipette tip solid-phase extraction with high-performance liquid chromatography method was developed for the determination of methyl parathion and fenthion in lettuce. The method yielded a linear calibration curve in the concentration ranges of 15-400 μg/kg for methyl parathion and 20-400 μg/kg for fenthion with correlation coefficients of above 0.9957. The limits of detection were 4.5 μg/kg for methyl parathion and 6.0 μg/kg for fenthion, respectively. The recoveries of methyl parathion and fenthion spiked in lettuce ranged from 96.0 to 104.2% with relative standard deviations less than 8.4%. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

75 FR 78243 - Propionic Acid and Salts, Urea Sulfate, Methidathion, and Methyl Parathion; Registration Review...

Science.gov (United States)

2010-12-15

... ENVIRONMENTAL PROTECTION AGENCY [EPA-HQ-OPP-2010-0650; FRL-8855-5] Propionic Acid and Salts, Urea.... 4078, urea sulfate, case no. 7213, methidathion, case no. 0034, and methyl parathion, case no. 0153... pesticides in the table below--propionic acid and salts, case 4078, urea sulfate, case no. 7213, methidathion...

Improving the capacity of biodegradation of two pesticides (methyl parathion, methomyl) by irradiated

International Nuclear Information System (INIS)

Gdoura, Meriem

2013-01-01

Radio-resistant strains isolated from mining sites in Khouribgua, have been identified following a morphological, biochemical and molecular level. The scope of the study is biodegradability of the two pesticides namely methyl parathion and methomyl through these identified strains .The objective of this research is to improve the biodegradability potential of pesticides by identified strains via ionizing radiation Gamma known for its mutagenic potential.

Photocatalytic degradation of Acephate, Omethoate, and Methyl parathion by Fe{sub 3}O{sub 4}@SiO{sub 2}@mTiO{sub 2} nanomicrospheres

Energy Technology Data Exchange (ETDEWEB)

Zheng, Lingling, E-mail: zllyslngj@126.com [State Key Laboratory of Food Science and Technology, School of Food Science of Jiangnan University, School of Food Science Synergetic Innovation Center of Food Safety and Quality Control, Wuxi, Jiangsu 214122 (China); Pi, Fuwei; Wang, Yifan [State Key Laboratory of Food Science and Technology, School of Food Science of Jiangnan University, School of Food Science Synergetic Innovation Center of Food Safety and Quality Control, Wuxi, Jiangsu 214122 (China); Xu, Hui [Key Laboratory of Healthy & Intelligent Kitchen System Integration, Ningbo, Zhejiang 315336 (China); Zhang, Yinzhi [State Key Laboratory of Food Science and Technology, School of Food Science of Jiangnan University, School of Food Science Synergetic Innovation Center of Food Safety and Quality Control, Wuxi, Jiangsu 214122 (China); Sun, Xiulan, E-mail: sxlzzz@jiangnan.edu.cn [State Key Laboratory of Food Science and Technology, School of Food Science of Jiangnan University, School of Food Science Synergetic Innovation Center of Food Safety and Quality Control, Wuxi, Jiangsu 214122 (China)

2016-09-05

Highlights: • An efficient photocatalyst Fe{sub 3}O{sub 4}@SiO{sub 2}@mTiO{sub 2} with high magnetic response and large specific surface area was synthesized. • Photocatalytic efficiency of Fe{sub 3}O{sub 4}@SiO{sub 2}@mTiO{sub 2} on Acephate, Omethoate, and Methyl Parathion was higher than TiO{sub 2} P-25. • Possible photocatalytic degradation mechanisms for the Acephate, Omethoate, and Methyl Parathion were proposed. - Abstract: A novel magnetic mesoporous nanomicrospheres Fe{sub 3}O{sub 4}@SiO{sub 2}@mTiO{sub 2} were synthetized and characterized by a series of techniques including FE-TEM, EDS, FE-SEM, PXRD, XPS, BET, TGA as well as VSM, and subsequently tested as a photocatalyst for the degradation of Acephate, Omethoate, and Methyl parathion under UV irradiation. The well-designed nanomicrospheres exhibit a pure and highly crystalline anatase TiO{sub 2} layer, large specific surface area, and high-magnetic-response. Photocatalytic degradation of the three organophosphorus pesticides (OPPs) and the formation intermediates were identified using HPLC, TOC-V{sub cpn}, IC, pH meter and GC–MS. Acephate, Omethoate, and Methyl parathion disappeared after 45 min, 45 min, and 80 min UV illumination, respectively. At the end of the treatment, the total organic carbon (TOC) of the OPPs was reduced 80–85%. The main mineralization products were SO{sub 4}{sup 2−}, NO{sub 3}{sup −} and PO{sub 4}{sup 3−} and Omethoate additionally formed NO{sub 2}{sup −}. Based on the results, we proposed the photocatalytic degradation pathways for Acephate, Omethoate, and Methyl parathion.

Cerium dioxide as a new reactive sorbent for fast degradation of parathion methyl and some other organophosphates

Czech Academy of Sciences Publication Activity Database

Janos, P.; Kuráň, P.; Kormunda, M.; Štengl, Václav; Matys Grygar, Tomáš; Došek, M.; Šťastný, M.; Ederer, J.; Pilařová, V.; Vrtoch, L.

2014-01-01

Roč. 32, č. 4 (2014), s. 360-370 ISSN 1002-0721 Institutional support: RVO:61388980 Keywords : cerium dioxide * carbonate precursor * lanthanides * organophosphate pesticide * parathion methyl * chemical warfare agents Subject RIV: CA - Inorganic Chemistry Impact factor: 1.261, year: 2014

Effecy of parathion-methyl on Amazonian fish and freshwater invertebrates: A comparison of sensivity with temperate data

NARCIS (Netherlands)

Rico Artero, A.; Geber, R.; Campos Souto, P.; Garcia, M.V.B.; Brink, van den P.J.

2010-01-01

Parathion-methyl is an organophosphorous insecticide that is widely used in agricultural production sites in the Amazon. The use of this pesticide might pose a potential risk for the biodiversity and abundance of fish and invertebrate species inhabiting aquatic ecosystems adjacent to the

Distribution of 14C- labelled methyl parathion in the house sparrow, Passer domesticus L

International Nuclear Information System (INIS)

Bhatia, P.; Garg, A.K.; Kochhar, V.

1994-01-01

The activity of an insecticide when evaluated on dynamic basis is largely explained by differences in the rate of penetration, distribution and excretion. These mechanisms determine the fate of insecticides in the living system. The distribution of an organophosphorus insecticide i.e. 14 C-methyl parathion, based studies conducted on various aspects of it in relation to house sparrow, is presented. 9 refs., 1 fig

Identification of a Marine Bacillus Strain C5 and Parathion-Methyl Degradation Characteristics of the Extracellular Esterase B1

Directory of Open Access Journals (Sweden)

Jianhua Hao

2014-01-01

Full Text Available A bacterial strain C5 that can produce new type of marine esterase was isolated and screened from marine sludge. According to 16S rRNA sequence analysis and physiological and biochemical experiments, the strain was identified as Bacillus subtilis. A single isozyme with a molecular weight of 86 kDa was observed by SDS-PAGE and native-PAGE. On this basis, the mechanism of esterase B1 secreted by strain C5 degrading parathion-methyl was explored, and the effects of temperature and pH on the degradation rate were investigated. From the results, p-nitrophenol was one of the degradation products of B1 degrading parathion-methyl, and the best degradation effect could be achieved at the temperature of 40°C and the neutral pH value.

The Vital Function of Fe3O4@Au nanocomposites for Hydrolase Biosensor Design and Its Application in Detection of Methyl Parathion

Energy Technology Data Exchange (ETDEWEB)

Zhao, Yuting; Zhang, Weiying; Lin, Yuehe; Du, Dan

2013-02-04

A nanocomposite of gold nanoparticles (AuNPs) decorating a magnetic Fe3O4 core was synthesized using cysteamine (SH–NH2) as linker, and characterized by TEM, XPS, UV and electrochemistry. Then a hydrolase biosensor, based on self-assembly of methyl parathion hydrolase (MPH) on the Fe3O4@Au nanocomposite, was developed for sensitive and selective detection of the organophosphorus pesticide (OP) methyl parathion. The magnetic nanocomposite provides an easy way to construct the enzyme biosensor by simply exerting an external magnetic field, and also provides a simple way to renew the electrode surface by removing the magnet. Unlike inhibition-based enzyme biosensors, the hydrolase is not poisoned by OPs and thus is reusable for continuous measurement. AuNPs not only provide a large surface area, high loading efficiency and fast electron transfer, but also stabilize the enzyme through electrostatic interactions. The MPH biosensor shows rapid response and high selectivity for detection of methyl parathion, with a linear range from 0.5 to 1000 ng/mL and a detection limit of 0.1 ng/mL. It also shows acceptable reproducibility and stability. The simplicity and ease of operation of the proposed method has great potential for on-site detection of P–S containing pesticides and provides a promising strategy to construct a robust biosensor.

Influence of agronomic amendments on the fate of bound methyl parathion residues in soils

International Nuclear Information System (INIS)

Gerstl, Z.; Helling, C.S.

1984-01-01

The fate of [ring- 14 C] methyl parathion in a silt loam soil was monitored during a 49-day incubation period. At this point, 54% of the initial 14 C remained in the soil; of this, 13% was extractable with MeOH and 87% was bound residue. Soils were then treated with inorganic and organic amendments and incubated an additional 70 days. Release of methyl parathion bound residues could not be demonstrated, but mineralization of both bound and extractable 14 C to 14 CO 2 was seen. Slow, continuous production of CO 2 , all at comparable rates, occurred with the controls and with amendments H 2 SO 4 , (NH 4 ) 2 SO 4 , NH 4 OH, chitin, oat seedlings, and oat straw. Glucose and asparagine caused high rates of 14 CO 2 production. HgCl 2 gave very high initial rates of 14 CO 2 loss; the rate declined to that of the control only after 9-10 weeks. The lime treatment exceeded the controls after 1 week, declining only slightly with time. The effects of sewage sludge and dairy manure were similar to the controls except that: (a) sludge caused a very high initial loss of 14 CO 2 , and (b) both treatments gave an unaccountable loss of 14 C, perhaps as 14 CH 4 from anaerobic conditions. By 70 days, levels of extractable 14 C and bound 14 C had both declined twice as rapidly in certain amended soils as in unamended controls. (author)

Water-based synthesis of TiO2/CeO2 composites supported on plasma-treated montmorillonite for parathion methyl degradation

Czech Academy of Sciences Publication Activity Database

Henych, Jiří; Kormunda, M.; Šťastný, Martin; Janoš, P.; Vomáčka, Petr; Matoušek, J.; Štengl, Václav

2017-01-01

Roč. 144, AUG (2017), s. 26-35 ISSN 0169-1317 R&D Projects: GA MŠk(CZ) LM2015073 Institutional support: RVO:61388980 Keywords : Montmorillonite * Parathion methyl * Plasma treatment * TiO2 /CeO2 composites Subject RIV: CA - Inorganic Chemistry OBOR OECD: Inorganic and nuclear chemistry Impact factor: 3.101, year: 2016

Effects of the organophosphorous methyl parathion on the branchial epithelium of a freshwater fish Metynnis roosevelti

Directory of Open Access Journals (Sweden)

Machado Marcelo Rubens

2003-01-01

Full Text Available Gills are vital structures for fish, since they are the main site for gaseous exchange as well as partially responsible for osmorregulation, acid-basic balance, excretion of nitrogenous compounds and taste. Chemicals in the water may alter the morphology of branchial cells of fish that are, therefore, a useful model for environmental impact and ecotoxicology studies. In order to investigate the effects of an organophosphorous compound, methyl parathion, on the gills of the fish, samples of Metynnis roosevelti were exposed to lethal (7ppm and sublethal (1ppm doses of Mentox 600 CE. Through light and scanning electron microscopy, shrinking of the branchial epithelium, followed by detachment and hyperplasia were observed. Externally, the branchial filaments presented the gradual disappearance of microridges. Even in sublethal doses, the organophosphorous reduced the health and fitness of these fish, as consequence of secondary effects derived from changes in the branchial epithelium, impairing oxygenation and ionic balance of the organism.

Twofold role of calcined hydrotalcites in the degradation of methyl parathion pesticide

Directory of Open Access Journals (Sweden)

Alvaro Sampieri

2011-02-01

Full Text Available Methyl parathion (MP is a very toxic organophosphate pesticide used as a non-systematic insecticide and acaricide on many corps. As MP and its by-products are highly toxic, they have to be retained to avoid pollution of rivers and lakes. Highly efficient sorbents are hydrotalcites (HTs (or anionic clays. We have correlated the degradation of an aqueous solution of MP at room temperature, with the basicity of the adsorbing materials. It was found that the metal composition of hydrotalcites determines both the surface electronic properties (basic or acidic and the sorption capacity. Depending on the basic strength, some calcined hydrotalcites can catalyze the transformation of MP to p-nitrophenol (p-NP and retain its by-products. Such a process has the advantage of being able to be carried out at room temperature and at the pH of the pesticide solution.

Development of a Novel Optical Biosensor for Detection of Organophoshorus Pesticides Based on Methyl Parathion Hydrolase Immobilized by Metal-Chelate Affinity

Science.gov (United States)

Lan, Wensheng; Chen, Guoping; Cui, Feng; Tan, Feng; Liu, Ran; Yushupujiang, Maolidan

2012-01-01

We have developed a novel optical biosensor device using recombinant methyl parathion hydrolase (MPH) enzyme immobilized on agarose by metal-chelate affinity to detect organophosphorus (OP) compounds with a nitrophenyl group. The biosensor principle is based on the optical measurement of the product of OP catalysis by MPH (p-nitrophenol). Briefly, MPH containing six sequential histidines (6× His tag) at its N-terminal was bound to nitrilotriacetic acid (NTA) agarose with Ni ions, resulting in the flexible immobilization of the bio-reaction platform. The optical biosensing system consisted of two light-emitting diodes (LEDs) and one photodiode. The LED that emitted light at the wavelength of the maximum absorption for p-nitrophenol served as the signal light, while the other LED that showed no absorbance served as the reference light. The optical sensing system detected absorbance that was linearly correlated to methyl parathion (MP) concentration and the detection limit was estimated to be 4 μM. Sensor hysteresis was investigated and the results showed that at lower concentration range of MP the difference got from the opposite process curves was very small. With its easy immobilization of enzymes and simple design in structure, the system has the potential for development into a practical portable detector for field applications. PMID:23012501

Methyl parathion inhibits the nuclear maturation, decreases the cytoplasmic quality in oocytes and alters the developmental potential of embryos of Swiss albino mice

Energy Technology Data Exchange (ETDEWEB)

Nair, Ramya; Singh, Vikram Jeet; Salian, Sujith Raj [Division of Clinical Embryology, Department of Obstetrics and Gynecology, Kasturba Medical College, Manipal University, Manipal 576 104 (India); Kalthur, Sneha Guruprasad; D' Souza, Antony Sylvan [Department of Anatomy, Kasturba Medical College, Manipal University, Manipal 576 104 (India); Shetty, Pallavi K.; Mutalik, Srinivas [Department of Pharmaceutics, Manipal College of Pharmaceutical Sciences, Manipal University, Manipal 576 104 (India); Kalthur, Guruprasad, E-mail: guru.kalthur@manipal.edu [Division of Clinical Embryology, Department of Obstetrics and Gynecology, Kasturba Medical College, Manipal University, Manipal 576 104 (India); Adiga, Satish Kumar [Division of Clinical Embryology, Department of Obstetrics and Gynecology, Kasturba Medical College, Manipal University, Manipal 576 104 (India)

2014-09-15

Methyl parathion (MP) is one of the most commonly used and extremely toxic organophosphorous group of pesticide. A large number of studies in the literature suggest that it has adverse effects on the male reproductive system. However, there is limited information about its toxicity to the female reproductive system. In the present study we report the toxic effects of methyl parathion on the female reproductive system using Swiss albino mice as the experimental model. The female mice were administered orally with 5, 10 and 20 mg/kg of MP. One week later, the mice were superovulated with pregnant mare serum gonadotrophin (PMSG) and human chorionic gonadotrophin (hCG) to study the quality of the oocytes, spindle organization, developmental potential of early embryos and the DNA integrity in blastocysts. MP exposure resulted in a non-significant decrease in the number of primordial follicles and increased DNA damage in granulosa cells. Though MP did not have any effect on the ovulation it had a significant inhibitory effect on the nuclear maturity of oocytes which was associated with spindle deformity. In addition, the oocytes had higher cytoplasmic abnormalities with depleted glutathione level. Even though it did not have any effect on the fertilization and blastocyst rate at lower doses, at 20 mg/kg MP it resulted in a significant decrease in blastocyst hatching, decrease in cell number and high DNA damage. While low body weight gain was observed in F1 generation from 5 mg/kg group, at higher dose, the body weight in F1 generation was marginally higher than control. Post-natal death in F1 generation was observed only in mice treated with 20 mg/kg MP. In conclusion, we report that MP has adverse effects on the oocyte quality, developmental potential of the embryo and reproductive outcome. - Highlights: • Methyl parathion induces severe cytoplasmic abnormalities in oocytes. • Inhibits nuclear maturation and spindle damage • Poor blastocyst quality and high DNA

Methyl parathion inhibits the nuclear maturation, decreases the cytoplasmic quality in oocytes and alters the developmental potential of embryos of Swiss albino mice

International Nuclear Information System (INIS)

Nair, Ramya; Singh, Vikram Jeet; Salian, Sujith Raj; Kalthur, Sneha Guruprasad; D'Souza, Antony Sylvan; Shetty, Pallavi K.; Mutalik, Srinivas; Kalthur, Guruprasad; Adiga, Satish Kumar

2014-01-01

Methyl parathion (MP) is one of the most commonly used and extremely toxic organophosphorous group of pesticide. A large number of studies in the literature suggest that it has adverse effects on the male reproductive system. However, there is limited information about its toxicity to the female reproductive system. In the present study we report the toxic effects of methyl parathion on the female reproductive system using Swiss albino mice as the experimental model. The female mice were administered orally with 5, 10 and 20 mg/kg of MP. One week later, the mice were superovulated with pregnant mare serum gonadotrophin (PMSG) and human chorionic gonadotrophin (hCG) to study the quality of the oocytes, spindle organization, developmental potential of early embryos and the DNA integrity in blastocysts. MP exposure resulted in a non-significant decrease in the number of primordial follicles and increased DNA damage in granulosa cells. Though MP did not have any effect on the ovulation it had a significant inhibitory effect on the nuclear maturity of oocytes which was associated with spindle deformity. In addition, the oocytes had higher cytoplasmic abnormalities with depleted glutathione level. Even though it did not have any effect on the fertilization and blastocyst rate at lower doses, at 20 mg/kg MP it resulted in a significant decrease in blastocyst hatching, decrease in cell number and high DNA damage. While low body weight gain was observed in F1 generation from 5 mg/kg group, at higher dose, the body weight in F1 generation was marginally higher than control. Post-natal death in F1 generation was observed only in mice treated with 20 mg/kg MP. In conclusion, we report that MP has adverse effects on the oocyte quality, developmental potential of the embryo and reproductive outcome. - Highlights: • Methyl parathion induces severe cytoplasmic abnormalities in oocytes. • Inhibits nuclear maturation and spindle damage • Poor blastocyst quality and high DNA

Development of a Novel Optical Biosensor for Detection of Organophoshorus Pesticides Based on Methyl Parathion Hydrolase Immobilized by Metal-Chelate Affinity

Directory of Open Access Journals (Sweden)

Wensheng Lan

2012-06-01

Full Text Available We have developed a novel optical biosensor device using recombinant methyl parathion hydrolase (MPH enzyme immobilized on agarose by metal-chelate affinity to detect organophosphorus (OP compounds with a nitrophenyl group. The biosensor principle is based on the optical measurement of the product of OP catalysis by MPH (p-nitrophenol. Briefly, MPH containing six sequential histidines (6× His tag at its N-terminal was bound to nitrilotriacetic acid (NTA agarose with Ni ions, resulting in the flexible immobilization of the bio-reaction platform. The optical biosensing system consisted of two light-emitting diodes (LEDs and one photodiode. The LED that emitted light at the wavelength of the maximum absorption for p-nitrophenol served as the signal light, while the other LED that showed no absorbance served as the reference light. The optical sensing system detected absorbance that was linearly correlated to methyl parathion (MP concentration and the detection limit was estimated to be 4 μM. Sensor hysteresis was investigated and the results showed that at lower concentration range of MP the difference got from the opposite process curves was very small. With its easy immobilization of enzymes and simple design in structure, the system has the potential for development into a practical portable detector for field applications.

Vitamin K3 (menadione) redox cycling inhibits cytochrome P450-mediated metabolism and inhibits parathion intoxication.

Science.gov (United States)

Jan, Yi-Hua; Richardson, Jason R; Baker, Angela A; Mishin, Vladimir; Heck, Diane E; Laskin, Debra L; Laskin, Jeffrey D

2015-10-01

Parathion, a widely used organophosphate insecticide, is considered a high priority chemical threat. Parathion toxicity is dependent on its metabolism by the cytochrome P450 system to paraoxon (diethyl 4-nitrophenyl phosphate), a cytotoxic metabolite. As an effective inhibitor of cholinesterases, paraoxon causes the accumulation of acetylcholine in synapses and overstimulation of nicotinic and muscarinic cholinergic receptors, leading to characteristic signs of organophosphate poisoning. Inhibition of parathion metabolism to paraoxon represents a potential approach to counter parathion toxicity. Herein, we demonstrate that menadione (methyl-1,4-naphthoquinone, vitamin K3) is a potent inhibitor of cytochrome P450-mediated metabolism of parathion. Menadione is active in redox cycling, a reaction mediated by NADPH-cytochrome P450 reductase that preferentially uses electrons from NADPH at the expense of their supply to the P450s. Using human recombinant CYP 1A2, 2B6, 3A4 and human liver microsomes, menadione was found to inhibit the formation of paraoxon from parathion. Administration of menadione bisulfite (40mg/kg, ip) to rats also reduced parathion-induced inhibition of brain cholinesterase activity, as well as parathion-induced tremors and the progression of other signs and symptoms of parathion poisoning. These data suggest that redox cycling compounds, such as menadione, have the potential to effectively mitigate the toxicity of organophosphorus pesticides including parathion which require cytochrome P450-mediated activation. Copyright © 2015 Elsevier Inc. All rights reserved.

Vitamin K3 (menadione) redox cycling inhibits cytochrome P450-mediated metabolism and inhibits parathion intoxication

Energy Technology Data Exchange (ETDEWEB)

Jan, Yi-Hua [Department of Environmental and Occupational Medicine, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ (United States); Richardson, Jason R., E-mail: jricha3@eohsi.rutgers.edu [Department of Environmental and Occupational Medicine, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ (United States); Baker, Angela A. [Department of Environmental and Occupational Medicine, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ (United States); Mishin, Vladimir [Department of Pharmacology and Toxicology, Rutgers University, Piscataway, NJ (United States); Heck, Diane E. [Department of Environmental Health Science, New York Medical College, Valhalla, NY (United States); Laskin, Debra L. [Department of Pharmacology and Toxicology, Rutgers University, Piscataway, NJ (United States); Laskin, Jeffrey D., E-mail: jlaskin@eohsi.rutgers.edu [Department of Environmental and Occupational Medicine, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ (United States)

2015-10-01

Parathion, a widely used organophosphate insecticide, is considered a high priority chemical threat. Parathion toxicity is dependent on its metabolism by the cytochrome P450 system to paraoxon (diethyl 4-nitrophenyl phosphate), a cytotoxic metabolite. As an effective inhibitor of cholinesterases, paraoxon causes the accumulation of acetylcholine in synapses and overstimulation of nicotinic and muscarinic cholinergic receptors, leading to characteristic signs of organophosphate poisoning. Inhibition of parathion metabolism to paraoxon represents a potential approach to counter parathion toxicity. Herein, we demonstrate that menadione (methyl-1,4-naphthoquinone, vitamin K3) is a potent inhibitor of cytochrome P450-mediated metabolism of parathion. Menadione is active in redox cycling, a reaction mediated by NADPH-cytochrome P450 reductase that preferentially uses electrons from NADPH at the expense of their supply to the P450s. Using human recombinant CYP 1A2, 2B6, 3A4 and human liver microsomes, menadione was found to inhibit the formation of paraoxon from parathion. Administration of menadione bisulfite (40 mg/kg, ip) to rats also reduced parathion-induced inhibition of brain cholinesterase activity, as well as parathion-induced tremors and the progression of other signs and symptoms of parathion poisoning. These data suggest that redox cycling compounds, such as menadione, have the potential to effectively mitigate the toxicity of organophosphorus pesticides including parathion which require cytochrome P450-mediated activation. - Highlights: • Menadione redox cycles with cytochrome P450 reductase and generates reactive oxygen species. • Redox cycling inhibits cytochrome P450-mediated parathion metabolism. • Short term administration of menadione inhibits parathion toxicity by inhibiting paraoxon formation.

Vitamin K3 (menadione) redox cycling inhibits cytochrome P450-mediated metabolism and inhibits parathion intoxication

International Nuclear Information System (INIS)

Jan, Yi-Hua; Richardson, Jason R.; Baker, Angela A.; Mishin, Vladimir; Heck, Diane E.; Laskin, Debra L.; Laskin, Jeffrey D.

2015-01-01

Parathion, a widely used organophosphate insecticide, is considered a high priority chemical threat. Parathion toxicity is dependent on its metabolism by the cytochrome P450 system to paraoxon (diethyl 4-nitrophenyl phosphate), a cytotoxic metabolite. As an effective inhibitor of cholinesterases, paraoxon causes the accumulation of acetylcholine in synapses and overstimulation of nicotinic and muscarinic cholinergic receptors, leading to characteristic signs of organophosphate poisoning. Inhibition of parathion metabolism to paraoxon represents a potential approach to counter parathion toxicity. Herein, we demonstrate that menadione (methyl-1,4-naphthoquinone, vitamin K3) is a potent inhibitor of cytochrome P450-mediated metabolism of parathion. Menadione is active in redox cycling, a reaction mediated by NADPH-cytochrome P450 reductase that preferentially uses electrons from NADPH at the expense of their supply to the P450s. Using human recombinant CYP 1A2, 2B6, 3A4 and human liver microsomes, menadione was found to inhibit the formation of paraoxon from parathion. Administration of menadione bisulfite (40 mg/kg, ip) to rats also reduced parathion-induced inhibition of brain cholinesterase activity, as well as parathion-induced tremors and the progression of other signs and symptoms of parathion poisoning. These data suggest that redox cycling compounds, such as menadione, have the potential to effectively mitigate the toxicity of organophosphorus pesticides including parathion which require cytochrome P450-mediated activation. - Highlights: • Menadione redox cycles with cytochrome P450 reductase and generates reactive oxygen species. • Redox cycling inhibits cytochrome P450-mediated parathion metabolism. • Short term administration of menadione inhibits parathion toxicity by inhibiting paraoxon formation.

Effect of Methyl Parathion on Survival and Development of Tadpoles of Indian Cricket frog Fejervarya limnocharis

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Hunasanahalli Puttaswamygowda Gurushankara

2016-04-01

Full Text Available Amphibian populations are declining due to various causes including pesticide contamination in natural habitat. We evaluated the effect of Methyl Parathion (MPT an organophosphate pesticide on survival and development of common paddy field frog Fejervarya limnocharis in a laboratory condition. Effect of 0 µg MPT/L, 500 µg MPT/L,1000 µg MPT/L, 1500 µg MPT/L, 2000 µg MPT/L and 3000 µg MPT/L was studied using static toxicity test for a duration of 28 days. MPT reduced the survival of tadpole. The mortality was increased with the increased concentration of pesticide. The development decreased with increased MPT concentrations. At higher concentrations, MPT induced slow development and tadpoles failed to metamorphose. It is assumed that slow development could affect the early larval life and amphibian population in the agroecosystem.

Impact of long term applications of cotton pesticides on soil biological properties, dissipation of [14C]-methyl parathion and persistence of multi-pesticide residues

International Nuclear Information System (INIS)

Andrea, M.M.; Peres, T.B.; Luchini, L.C.; Marcondes, M.A.; Pettinelli, A. Jr.; Nakagawa, L.E.

2001-01-01

Biological parameters were followed in soils from a cotton farm (Tatui) where the recommended pesticides have been used for years, and from an experimental field (Sao Paulo) which was subdivided in two areas: one received the recommended pesticides and the other was maintained untreated. The soil bioactivities monitored from 1995 to 1998, after different pesticide applications, were: basal and glucose-induced respiration; anaerobic activity; nitrification rate; activity of the enzymes: dehydrogenase, aryl sulfatase and arginine deaminase; the soil capacity to mineralize an aromatic pesticide molecule ([ 14 C]-2,4-D), fungal and bacterial contributions for soil respiration until the beginning of 1998, and fungal and bacterial numbers from the beginning of 1998. The dissipation of [ 14 C]-methyl parathion - one of the recommended pesticides - was followed by radiometric techniques only in Sao Paulo, but persistence of multi-residues was determined in both soils by gas-liquid chromatography. All the biological parameters varied each sampling time and values also varied among soil samples, being inhibited or stimulated by the different pesticide applications, but they mostly recovered the initially detected activity. Dissipation of methyl parathion was fast and not affected by the other pesticide applications. Pesticide residues varied between the two soils but were mostly low after all applications, which indicates their dissipation. (author)

Adsorption and desorption characteristics of lindane, carbofuran and methyl parathion on various Indian soils

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Rama Krishna, K. [Department of Civil Engineering, Indian Institute of Technology Madras, Chennai 600036 (India)], E-mail: ramakrishnaiitm@gmail.com; Philip, Ligy [Department of Civil Engineering, Indian Institute of Technology Madras, Chennai 600036 (India)], E-mail: ligy@iitm.ac.in

2008-12-30

Adsorption and desorption characteristics of three insecticides on four Indian soils were studied. Insecticides used were representative of organochlorine, organophosphate, and carbomate groups. The order of adsorption of pesticides on soils was: lindane > methyl parathion > carbofuran. Compost soil had shown the maximum adsorption capacity. The order of adsorption capacity of various soils were: compost soil > clayey soil > red soil > sandy soil. Adsorption isotherms were better fitted to Freundlich model and K{sub f} values increased with increase in organic matter content of the soils. Thermodynamic parameters indicated favorable adsorption of all the three pesticides in four different soils. Adsorption was exothermic in nature. Distilled water desorbed 30-60% of adsorbed pesticides whereas; organic solvents were able to affect 50-80% of sorbed pesticides. Clay content and organic matter played a significant role in pesticide adsorption and desorption processes. Hysteresis effect was observed in red, clayey and compost soils. Hysteresis effect increased with increase in organic matter and clay content of the soils.

Adsorption and desorption characteristics of lindane, carbofuran and methyl parathion on various Indian soils

International Nuclear Information System (INIS)

Rama Krishna, K.; Philip, Ligy

2008-01-01

Adsorption and desorption characteristics of three insecticides on four Indian soils were studied. Insecticides used were representative of organochlorine, organophosphate, and carbomate groups. The order of adsorption of pesticides on soils was: lindane > methyl parathion > carbofuran. Compost soil had shown the maximum adsorption capacity. The order of adsorption capacity of various soils were: compost soil > clayey soil > red soil > sandy soil. Adsorption isotherms were better fitted to Freundlich model and K f values increased with increase in organic matter content of the soils. Thermodynamic parameters indicated favorable adsorption of all the three pesticides in four different soils. Adsorption was exothermic in nature. Distilled water desorbed 30-60% of adsorbed pesticides whereas; organic solvents were able to affect 50-80% of sorbed pesticides. Clay content and organic matter played a significant role in pesticide adsorption and desorption processes. Hysteresis effect was observed in red, clayey and compost soils. Hysteresis effect increased with increase in organic matter and clay content of the soils

Simultaneous detection of imidacloprid and parathion by the dual-labeled time-resolved fluoroimmunoassay.

Science.gov (United States)

Shi, Haiyan; Sheng, Enze; Feng, Lu; Zhou, Liangliang; Hua, Xiude; Wang, Minghua

2015-10-01

A highly sensitive direct dual-labeled time-resolved fluoroimmunoassay (TRFIA) to detect parathion and imidacloprid simultaneously in food and environmental matrices was developed. Europium (Eu(3+)) and samarium (Sm(3+)) were used as fluorescent labels by coupling separately with L1-Ab and A1P1-Ab. Under optimal assay conditions, the half-maximal inhibition concentration (IC50) and limit of detection (LOD, IC10) were 10.87 and 0.025 μg/L for parathion and 7.08 and 0.028 μg/L for imidacloprid, respectively. The cross-reactivities (CR) were negligible except for methyl-parathion (42.4 %) and imidaclothiz (103.4 %). The average recoveries of imidacloprid ranged from 78.9 to 104.2 % in water, soil, rice, tomato, and Chinese cabbage with a relative standard deviation (RSD) of 2.4 to 11.6 %, and those of parathion were from 81.5 to 110.9 % with the RSD of 3.2 to 10.5 %. The results of TRFIA for the authentic samples were validated by comparison with gas chromatography (GC) analyses, and satisfactory correlations (parathion: R (2) = 0.9918; imidacloprid: R (2) = 0.9908) were obtained. The results indicate that the dual-labeled TRFIA is convenient and reliable to detect parathion and imidacloprid simultaneously in food and environmental matrices.

Burkholderia jiangsuensis sp. nov., a methyl parathion degrading bacterium, isolated from methyl parathion contaminated soil.

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Liu, Xu-Yun; Li, Chun-Xiu; Luo, Xiao-Jing; Lai, Qi-Liang; Xu, Jian-He

2014-09-01

A methyl parathion (MP) degrading bacterial strain, designated MP-1(T), was isolated from a waste land where pesticides were formerly manufactured in Jiangsu province, China. Polyphasic taxonomic studies showed that MP-1(T) is a Gram-stain-negative, non-spore-forming, rod-shaped and motile bacterium. The bacterium could grow at salinities of 0-1 % (w/v) and temperatures of 15-40 °C. Strain MP-1(T) could reduce nitrate to nitrite, utilize d-glucose and l-arabinose, but not produce indole, or hydrolyse gelatin. Phylogenetic analysis based on 16S rRNA gene sequences demonstrated that MP-1(T) belongs to the genus Burkholderia, showing highest sequence similarity to Burkholderia grimmiae DSM 25160(T) (98.5 %), and similar strains including Burkholderia zhejiangensis OP-1(T) (98.2 %), Burkholderia choica LMG 22940(T) (97.5 %), Burkholderia glathei DSM 50014(T) (97.4 %), Burkholderia terrestris LMG 22937(T) (97.2 %) and Burkholderia telluris LMG 22936(T) (97.0 %). In addition, the gyrB and recA gene segments of strain MP-1(T) exhibited less than 89.0 % and 95.1 % similarities with the most highly-related type strains indicated above. The G+C content of strain MP-1(T) was 62.6 mol%. The major isoprenoid quinone was ubiquinone Q-8. The predominant polar lipids comprised phosphatidyl ethanolamine, phosphatidyl glycerol, aminolipid and phospholipid. The principal fatty acids in strain MP-1(T) were C18 : 1ω7c/C18 : 1ω6c (23.3 %), C16 : 0 (16.8 %), cyclo-C17 : 0 (15.0 %), C16 : 1ω7c/C16 : 1ω6 (8.5 %), cyclo-C19 : 0ω8c (8.1 %), C16 : 1 iso I/C14 : 0 3-OH (5.7 %), C16 : 0 3-OH (5.6 %) and C16 : 02-OH (5.1 %). The DNA-DNA relatedness values between strain MP-1(T) and the three type strains (B. grimmiae DSM 25160(T), B. zhejiangensis OP-1(T) and B. glathei DSM 50014(T)) ranged from 24.6 % to 37.4 %. In accordance with phenotypic and genotypic characteristics, strain MP-1(T) represents a novel

Effects of the organophosphorus pesticide Folisuper 600 (methyl parathion on the heart function of bullfrog tadpoles, Lithobates catesbeianus (Shaw, 1802

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M. J. Costa

Full Text Available Abstract The aim of this work was to evaluate whether the heart function of bullfrog tadpoles (25 Gosner stage is affected by their acute exposure (48 h to a sub-lethal concentration (10 µg.L–1 of the active principle of the organophosphorus pesticide Folisuper 600R (methyl parathion - MP. Our results demonstrated that MP causes not only a reduction in tadpoles’ cardiac ventricular mass, resulting in a marked reduction in their cardiac twitch force, but also impairs their swimming performance, irrespective of increasing their heart rate. Together, these findings indicate that low and realistic concentration of MP have a negative impact on tadpoles’ performance, jeopardizing their survival.

Magnetically separable reactive sorbent based on the CeO2/γ-Fe2O3 composite and its utilization for rapid degradation of the organophosphate pesticide parathion methyl and certain nerve agents

Czech Academy of Sciences Publication Activity Database

Janoš, P.; Kuráň, P.; Pilařová, V.; Trögl, J.; Šťastný, M.; Pelant, O.; Henych, Jiří; Bakardjieva, Snejana; Životský, O.; Kormunda, M.; Mazanec, K.; Skoumal, M.

2015-01-01

Roč. 262, FEB (2015), s. 747-755 ISSN 1385-8947 R&D Projects: GA ČR(CZ) GAP106/12/1116 Institutional support: RVO:61388980 Keywords : Magnetically separable sorbent * Destructive sorption * Cerium oxide * Parathion methyl * Toxic organophosphates Subject RIV: CA - Inorganic Chemistry Impact factor: 5.310, year: 2015

Methyl Parathion Masks Withdrawal from Physical Dependence on Morphine

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Robin W. Rockhold

2002-10-01

Full Text Available Abstract: The cholinergic system has been proposed to participate in the development of dependence on opioids. The present study examined effects of dermal pretreatment with methyl parathion (MP, an acetylcholinesterase inhibitor, on the development of physical dependence on morphine. Opioid dependence was induced by continuous intracerebroventricular (i.c.v. infusion of morphine (26 nmol/μl/h for 3 days in adult male Sprague-Dawley rats. Each rat received two doses of MP, 12.5 mg/kg, dermally, initially, 3 days prior to initiation of i.c.v. morphine infusion and again on the first day of infusion. Withdrawal was precipitated after 3 days of infusion by administering an opioid antagonist, naloxone (48 nmol/5 μl, i.c.v.. Twelve of 23 MP-treated rats exhibited signs of acetylcholinesterase inhibitor intoxication (mild tremors and showed reduced spontaneous locomotor activity (tested by an open field test, prior to naloxone. The brain cholinesterase activity in these 12 rats was 13% of levels in control rats. Eleven rats that did not show toxic signs, exhibited cholinesterase activities that were 20% of control (not significant versus toxic group. The group that showed signs of MP intoxication exhibited a significantly lower incidence of opioid withdrawal jumping, rearing and wet dog shakes compared with the non-toxic group. No differences between quantal withdrawal signs (ptosis, penis-licking, and vocalization were noted between the two groups. The results suggest that toxic inhibition of acetylcholinesterase non-specifically reduces locomotor activity and may obscure certain behavioral signs of withdrawal from opioid dependence. This indicates that caution should be used in interpreting a direct involvement of acetylcholinesterase inhibition in preventing opioid dependence.

Facile green synthesis of graphene-Au nanorod nanoassembly for on-line extraction and sensitive stripping analysis of methyl parathion

International Nuclear Information System (INIS)

Zhu, Wenxin; Liu, Wei; Li, Tianbao; Yue, Xiaoyue; Liu, Tao; Zhang, Wentao; Yu, Shaoxuan; Zhang, Daohong; Wang, Jianlong

2014-01-01

Graphical abstract: Schematic illustration for the facile green fabrication of GN-AuNRs/GCE and its application for the extraction and electroanalysis of MP. - Highlights: • This paper described a facile green electrochemical approach to synthesize graphene-AuNRs nanocomposite. • The as-synthesized sensor shows low LOD and wide linear concentration range towards MP. • The sensor can be well used for the determination of MP in water and kiwi fruits samples. • This paper further enlarges the scope of facile green synthetic methods of GN-based hybrids. - Abstract: This paper described a facile green electrochemical approach to synthesize graphene-AuNRs nanocomposite (GN-AuNRs) onto glassy carbon electrode (GCE) for electrocatalytic analysis of methyl parathion (MP). This electrochemical synthesis of GN-AuNRs hybrid is environmentally friendly for not involving the chemical reduction of graphene oxide (GO) and facile for just on the basis of electrostatic interaction between GO and AuNRs, as well as electrochemical reduction of GO-AuNRs to GN-AuNRs. Combined the high conductivity, large surface area, good adsorption capacity towards aromatic rings and high catalytic ability of graphene with the excellent electronic properties and adsorption capacity of AuNRs, the high sensitive methyl parathion sensor was fabricated with the GN-AuNRs nanocomposite. The limit of detection (LOD) of the proposed sensor was calculated to be 0.82 ng/mL, which was lower than many previously reported enzyme or nonenzyme-based sensors. In the meantime, the linear detection range of this sensor was from 10 to 500 ng/mL and 750 to 4000 ng/mL, which was also wider than many other enzyme or enzymeless sensors. Furthermore, the facile and green electrochemical reduction strategy provided here could also be used to construct more GN-based hybrids. And the GN-based hybrid might be a new and highly efficient SPE factor, which opens new opportunities for green, facile and sensitive analysis of

Parathion poisoning of Mississippi kites in Oklahoma

Science.gov (United States)

Franson, J. Christian

1994-01-01

Parathion(phosphorothioic acid O, O-diethyl O-[4-nitrophenyl] ester) is a broad spectrum organophosphorus insecticide, used on a variety of crops and occasionally for mosquito control, and is highly toxic to birds (Smith 1987). Intentional poisoning with parathion is reported to have killed more than 8000 red-winged blackbirds (Agelaius phoeniceus), common grackles (Quiscalus quiscula), brown-headed cowbirds (Molothrus ater) and European starlings (Sturnus vulgaris) in two separate instances (Stone et al. 1984). Use of parathion on wheat fields has resulted in the mortality of about 1600 Canada geese (Branta canadensis) and other waterfowl in one instance (White et al. 1982) and about 200 Canada geese in another (Flickinger et al. 1991). More than 200 laughing gulls (Larus atricilla) died near cotton fields treated with parathion (White et al. 1979). Secondary poisoning of raptors resulting from the consumption of prey exposed to parathion, has been reported experimentally and in the field. Stone et al. (1984) found two dead red-tailed hawks (Buteo jamaicensis), a Cooper's hawk (Accipiter cooperii) and an American kestrel (Falco sparverius) that had fed on blackbirds killed by parathion. One of four American kestrels died after being fed cricket frogs (Acris crepitans) that had been exposed to 10ppm parathion for 96 hr (Fleming et al. 1982). The Mississippi kite (Ictinia mississippensis) is highly insectivorous (Brown and Amadon 1968) and is thus subject to secondary poisoning resulting from consumption of insects exposed to pesticides. I report here an instance of secondary parathion poisoning in wild Mississippi kites.

Effect of subchronic administration of methyl parathion on in vivo protein synthesis in pregnant rats and their conceptuses

International Nuclear Information System (INIS)

Gupta, R.C.; Thornburg, J.E.; Stedman, D.B.; Welsch, F.

1984-01-01

Pregnant rats received daily po doses of the organophosphate methyl parathion (MPTH) from Day 6 through Day 15 or 19 of gestation at doses causing no (1.0 mg/kg) or minimal (1.5 mg/kg) signs of maternal toxicity. Following the dose of MPTH on Day 15 or 19, in vivo protein synthesis was measured 0.5, 1.0, and 2.0 hr after sc injection of L-[1- 14 C]valine at a dose of 5 microCi/mmol/100 g body wt. The specific activity of [ 14 C]valine in the free amino acid pool and protein bound pool was significantly reduced in various regions of maternal brain and in maternal viscera, placenta, and whole embryos (Day 15), and in fetal brain and viscera (Day 19). The inhibitory effect of MPTH on net protein synthesis was dose dependent, greater on Day 19 than 15 of gestation and more pronounced in fetal than in maternal tissues

Characterization of methyl parathion degradation by a Burkholderia zhejiangensis strain, CEIB S4-3, isolated from agricultural soils.

Science.gov (United States)

Popoca-Ursino, Elida C; Martínez-Ocampo, Fernando; Dantán-González, Edgar; Sánchez-Salinas, Enrique; Ortiz-Hernández, Ma Laura

2017-12-01

Through the use of an enrichment technique, we isolated from the agricultural soils of Morelos in central México a strain of Burkholderia zhejiangensis identified as CEIB S4-3, it's could use the pesticide methyl parathion (MP) as the only source of carbon and degrade completely p-nitrophenol (PNP). For more efficient MP and PNP degradation by the CEIB S4-3 strain, the absence of an extra carbon source, a large inoculum and an MP concentration up to 50 mg/l are required. Sequence and annotation analysis of the draft genome, showed presence of mpd functional gene, which was expressed and its activity on the MP was confirmed. Additionally, the genes coding for enzymes in the benzoquinone pathway (conducted by Gram-negative bacteria) and the benzenotriol pathway (conducted by Gram-positive bacteria) were found, which was corroborated by identification of intermediary metabolites by HPLC. Thus, we propose that B. zhejiangensis CEIB S4-3 uses both degradation pathways.

Improving the secretion of a methyl parathion hydrolase in Pichia pastoris by modifying its N-terminal sequence.

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Ping Wang

Full Text Available Pichia pastoris is commonly used to express and secrete target proteins, although not all recombinant proteins can be successfully produced. In this study, we used methyl parathion hydrolase (MPH from Ochrobactrum sp. M231 as a model to study the importance of the N-terminus of the protein for its secretion. While MPH can be efficiently expressed intracellularly in P. pastoris, it is not secreted into the extracellular environment. Three MPH mutants (N66-MPH, D10-MPH, and N9-MPH were constructed through modification of its N-terminus, and the secretion of each by P. pastoris was improved when compared to wild-type MPH. The level of secreted D10-MPH was increased to 0.21 U/mL, while that of N9-MPH was enhanced to 0.16 U/mL. Although N66-MPH was not enzymatically active, it was secreted efficiently, and was identified by SDS-PAGE. These results demonstrate that the secretion of heterologous proteins in P. pastoris may be improved by modifying their N-terminal structures.

Mechanism and kinetics of parathion degradation under ultrasonic irradiation

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Yao Juanjuan, E-mail: yao_juanjuan@yahoo.cn [State Key laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai, 200092 (China); Gao Naiyun; Li Cong; Li Lei; Xu Bin [State Key laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai, 200092 (China)

2010-03-15

The parathion degradation under ultrasonic irradiation in aqueous solution was investigated. The results indicate that at the conditions in question, degradation rate of parathion decreased with increasing initial concentration and decreasing power. The optimal frequency for parathion degradation was 600 kHz. The free radical reactions predominate in the sonochemical degradation of parathion and the reaction zones are predominately at the bubble interface and, to a much lesser extent, in bulk solution. The gas/liquid interfacial regions are the real effective reaction sites for sonochemical degradation of parathion. The reaction can be well described as a gas/liquid heterogeneous reaction which obeys a kinetic model based on Langmuir-Hinshelwood model. The main pathways of parathion degradation by ultrasonic irradiation were also proposed by qualitative and quantitative analysis of organic and inorganic byproducts. It is indicated that the N{sub 2} in air takes part in the parathion degradation through the formation of {center_dot}NO{sub 2} under ultrasonic irradiation. Parathion is decomposed into paraoxon and 4-nitrophenol in the first step via two different pathways, respectively, which is in agreement with the theoretical molecular orbital (MO) calculations.

Degradation of Parathion by Microorganisms from Cranberry Bogs

International Nuclear Information System (INIS)

Gorder, G.W.; Lichtenstein, E.P.

1981-01-01

Full text: Oxygen concentration and different carbon sources drastically altered parathion degradation in culture media inoculated with microorganisms from Wisconsin cranberry (Vaccinium macrocarpon Ait.) growing soils. These microorganisms also grew in basal salts media utilizing parathion as a sole carbon source. 14 CO 2 was produced only from phenyl-labelled parathion while 14 C-(ethyl)-parathion derived radiocarbon remained in the stale media of the soil-free cultures. Addition of 0.05% glucose to basal salts medium inhibited 14 C-(phenyl)-parathion degradation while the addition of 0.05% yeast extract to basal salts medium also inhibited microbiological degradation of the insecticide to 14 CO 2 , but to a lesser extent. Aminoparathion and aminoparaoxon were formed only in basal salts medium with 0.05% yeast extract. Aerobic cultures produced more 14 CO 2 from 14 C-(phenyl)-parathion and less aminoparathion than anaerobic cultures. Aminoparathion was more abundant in cultures with inocula obtained from the 18- to 23-cm layer than with culture inocula obtained from the 0- to 5-cm soil layer under both aerobic and anaerobic conditions. (author)

Dual-opposite multi-walled carbon nanotube modified carbon fiber microelectrode for microfluidic chip-capillary electrophoresis determination of methyl parathion metabolites in human urine.

Science.gov (United States)

Du, Fuying; Fung, Ying-Sing

2018-03-03

Methyl parathion (MP) is a highly toxic organophosphate and its exposure may lead to substantial adverse effects to human health. The existence of 4-nitrophenol (4-NP) in the form of free phenol, glucuronide (4-NP-G) or as a sulfate ester (4-NP-S) can be used as biomarkers to assess the duration and extent of MP exposure. In this work, a MC-CE device incorporating post-CE amperometric detection using multi-walled carbon nanotubes (MWNTs) modified carbon fiber microelectrode (CFME) was fabricated and assessed for simultaneous determination of 4-NP, 4-NP-G, and 4-NP-S in human urine. The detection sensitivity and stability was greatly enhanced by the modification of MWNTs. The capability of the MC-CE device with dual MWNTs modified CFME for detecting impurity was assessed and reliability established by high recoveries from 95 to 97% for spiked MP biomarkers. The method developed is shown to provide a simple, sensitive, and reliable means for monitoring 4-NP, 4-NP-G, and 4-NP-S in human urine. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dietary modulation of parathion-induced neurotoxicity in adult and juvenile rats.

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Liu, Jing; Karanth, Subramanya; Pope, Carey

2005-06-01

Previous studies indicated that dietary glucose (15% in drinking water) could markedly exacerbate the toxicity of parathion in adult rats. The present study evaluated the effect of consumption of the commonly used sweetener, high fructose corn syrup (HFCS), on parathion toxicity in adult and juvenile rats. Animals were given free access to either water or 15% HFCS in drinking water for a total of 10 days and challenged with parathion (6 or 18 mg/kg, s.c., for juveniles or adults, respectively) on the 4th day. Signs of cholinergic toxicity, body weight and chow/fluid intake were recorded daily. Acetylcholinesterase (AChE) activity and immunoreactivity (AChE-IR) in frontal cortex and diaphragm were measured at 2, 4, and 7 days after parathion. As HFCS was associated with significant reduction in chow intake, adult rats were also pair-fed to evaluate the effect of similar reduced chow intake alone on parathion toxicity. The results indicated that the cholinergic toxicity of parathion was significantly increased by HFCS feeding in both age groups. The excess sugar consumption, however, did not significantly affect parathion-induced AChE inhibition in either tissue or either age group. Enzyme immunoreactivity in frontal cortex was generally not affected in either age group while diaphragm AChE-IR was significantly reduced by parathion and HFCS alone in adult animals at 2 and 4 days timepoints, and more so by the combination of sugar feeding and parathion exposure in both age groups. Food restriction alone did not exacerbate parathion toxicity. While the mechanism(s) remains unclear, we conclude that voluntary consumption of the common sweetener HFCS can markedly amplify parathion acute toxicity in both juvenile and adult rats.

Modulation of parathion toxicity by glucose feeding: Is nitric oxide involved?

International Nuclear Information System (INIS)

Liu Jing; Gupta, Ramesh C.; Goad, John T.; Karanth, Subramanya; Pope, Carey

2007-01-01

Glucose feeding can markedly exacerbate the toxicity of the anticholinesterase insecticide, parathion. We determined the effects of parathion on brain nitric oxide and its possible role in potentiation of toxicity by glucose feeding. Adult rats were given water or 15% glucose in water for 3 days and challenged with vehicle or parathion (18 mg/kg, s.c.) on day 4. Functional signs, plasma glucose and brain cholinesterase, citrulline (an indicator of nitric oxide production) and high-energy phosphates (HEPs) were measured 1-3 days after parathion. Glucose feeding exacerbated cholinergic toxicity. Parathion increased plasma glucose (15-33%) and decreased cortical cholinesterase activity (81-90%), with no significant differences between water and glucose treatment groups. In contrast, parathion increased brain regional citrulline (40-47%) and decreased HEPs (18-40%) in rats drinking water, with significantly greater changes in glucose-fed rats (248-363% increase and 31-61% decrease, respectively). We then studied the effects of inhibiting neuronal nitric oxide synthase (nNOS) by 7-nitroindazole (7NI, 30 mg/kg, i.p. x4) on parathion toxicity and its modulation by glucose feeding. Co-exposure to parathion and 7NI led to a marked increase in cholinergic signs of toxicity and lethality, regardless of glucose intake. Thus, glucose feeding enhanced the accumulation of brain nitric oxide following parathion exposure, but inhibition of nitric oxide synthesis was ineffective at counteracting increased parathion toxicity associated with glucose feeding. Evidence is therefore presented to suggest that nitric oxide may play both toxic and protective roles in cholinergic toxicity, and its precise contribution to modulation by glucose feeding requires further investigation

Clinical observation on parathion poisoning

Energy Technology Data Exchange (ETDEWEB)

Park, Heung Il; Kwun, Chung Sik [Chonnam University Medical School, Kwangju (Korea, Republic of)

1972-09-15

A total of 158 cases of parathion poisoning were clinically observed in Chonnam University Hospital from January, 1968 to June, 1972 with the following results. 1. The males were 133 and the females, 25 (radio, about 5:1) with 93 patients (58.9%) in the age group of 21 to 40 years old and the majority of the patients were farmers. 2. 158 cases could be divided into 38 cases of inhalation group (group I) and 120 cases of ingestion group (group II). The group I entirely occurred by accident during spraying the parathion, whereas the group II mostly developed by ingestion of the parathion for the suicide purpose. 3. During the period from 1968 to 1972, more frequent incidence of parathion poisoning showed up in 1971 and 1972. Inhalation group mostly occurred on July, August, and September, but several cases appeared sporadically in the rest of the months. 4. Most patients came to our Hospital within 4 hours after parathion poisoning and were discharged from the Hospital within one or two days after admission. Mortality was 2 cases (5.3%) out of 38 cases in inhalation group and was 26 cases (21.7%) out of 120 cases in ingestion group. 5. Clinical signs and symptoms showing high incidence were bronchorrhoea (incidence of 38.6%), dyspnea (57.6%), vomiting (62.0%), abdominal cramps (20.0%), sialorrhoea (53.8%), tachycardia (32.2%), miosis (67.7%), fasciculation (19.0%), hypertension (27.9%), drowsiness and confusion (50.0%), leukocytosis (58.3%), elevation of SGOT (23.0%), whereas mydriasis (5.7%), and proteinuria (4.0%) were low in incidence. All the ten cases (6.3%) showing involuntary defecation expired. 6. Roentgenographs of the chest were taken to 39 cases out of a total of 158 cases and revealed 21 cases (54.0%) of normal chest, 11 cases (28.0%) of bilateral pulmonary congestion, 7 cases (18.0%) of pulmonary edema or pneumonic consolidation.

Hapten design and indirect competitive immunoassay for parathion determination: Correlation with molecular modeling and principal component analysis

Energy Technology Data Exchange (ETDEWEB)

Liu Yihua [Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou 310029 (China); Jin Maojun [Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou 310029 (China); Gui Wenjun [Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou 310029 (China); Cheng Jingli [Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou 310029 (China); Guo Yirong [Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou 310029 (China); Zhu Guonian [Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou 310029 (China)]. E-mail: zhugn@zju.edu.cn

2007-05-22

A novel procedure for parathion hapten design is described. The optimal antigen for parathion was selected after molecular modeling studies of six types of potentially immunizing haptens with the aim to identify the best mimicking target analyte. Heterologous competitive indirect enzyme-linked immunosorbent assay (ELISA) was developed after screening a battery of competitors as coating antigens. The relationship between the heterology degree of the competitor and the resulting immunoassay detectability was investigated according to the electronic similarities of the competitor haptens and the target analyte. Molecular modeling and principal component analysis were performed to understand the electronic distribution and steric parameters of the haptens at their minimum energetic levels. The results suggested that the competitors should have a high heterology to produce assays with good detectability values. An indirect competitive ELISA was finally selected for further investigation. The immunoassay had an IC{sub 50} value of 4.79 ng mL{sup -1} and a limit of detection of 0.31 ng mL{sup -1}. There was little or no cross-reactivity to similar compounds tested except for the insecticide parathion-methyl, which showed a cross-reactivity of 7.8%.

DDE increased the toxicity of parathion to coturnix quail

Science.gov (United States)

Ludke, J.L.

1977-01-01

Adult male Japanese quail (Coturnix coturnix) were exposed to DDE or chlordane in the diet and subsequently dosed with parathion or paraoxon. Pretreatment with 5 or 50 ppm DDE in the diet for 12 weeks resulted in increased cholinesterase (ChE) activity in plasma, but not in the brain. Dietary concentrations of 5 and 50 ppm DDE caused increased susceptibility of quail that were challenged with parathion or paraoxon. The increased mortality resulting from DDE pretreatment was reflected in brain ChE inhibition. The synergistic action of DDE was apparent after 3 days of exposure to 50 ppm DDE and 1 week of exposure to 5 ppm DDE. Birds exposed for 3 weeks to 5 or 50 ppm DDE retained their DDE-potentiated sensitivity to parathion after 2 weeks on clean diet. Chlordane pretreatment resulted in decreased susceptibility (antagonism) to parathion, but not to paraoxon dosage. Implications of differing responses in ChE and mortality among controls, DDE-, and chlordane-pretreated birds after parathion or paraoxon dosage are discussed.

Methyl-parathion decreases sperm function and fertilization capacity after targeting spermatocytes and maturing spermatozoa

Energy Technology Data Exchange (ETDEWEB)

Pina-Guzman, Belem; Sanchez-Gutierrez, M.; Marchetti, Francesco; Hernandez-Ochoa, I.; Solis-Heredia, M.J .; Quintanilla-Vega, B.

2009-05-03

Paternal germline exposure to organophosphorous pesticides (OP) has been associated with reproductive failures and adverse effects in the offspring. Methyl parathion (Me-Pa), a worldwide-used OP, has reproductive adverse effects and is genotoxic to sperm. Oxidative damage has been involved in the genotoxic and reproductive effects of OP. The purpose of this study was to determine the effects of Me-Pa on spermatozoa function and ability to fertilize. Male mice were exposed to Me-Pa (20 mg/kg bw, i.p.) and spermatozoa from epididymis-vas deferens were collected at 7 or 28 days post-treatment (dpt) to assess the effects on maturing spermatozoa and spermatocytes, respectively. DNA damage was evaluated by nick translation (NT-positive cells) and SCSA (percentDFI); lipoperoxidation (LPO) by malondialdehyde production; sperm function by spontaneous- and induced-acrosome reactions (AR); mitochondrial membrane potential (MMP) by using the JC-1 flurochrome; and, fertilization ability by an in vitro assay and in vivo mating. Results showed alterations in DNA integrity (percentDFI and NT-positive cells) at 7 and 28 dpt, in addition to decreased sperm quality and a decrease in induced-AR; reduced MMP and LPO was observed only at 7 dpt. We found negative correlations between LPO and all sperm alterations. Altered sperm functional parameters were associated with reduced fertilization rates at both times, evaluated either in vitro or in vivo. These results show that Me-Pa exposure of maturing spermatozoa and spermatocytes affects many sperm functional parameters that result in a decreased fertilizing capacity. Oxidative stress seems to be a likely mechanism ofthe detrimental effects of Me-Pa in male germ cells.

Methyl-parathion decreases sperm function and fertilization capacity after targeting spermatocytes and maturing spermatozoa

International Nuclear Information System (INIS)

Pina-Guzman, B.; Sanchez-Gutierrez, M.; Marchetti, F.; Hernandez-Ochoa, I.; Solis-Heredia, M.J.; Quintanilla-Vega, B.

2009-01-01

Paternal germline exposure to organophosphorous pesticides (OP) has been associated with reproductive failures and adverse effects in the offspring. Methyl-parathion (Me-Pa), a worldwide-used OP, has reproductive adverse effects and is genotoxic to sperm, possibly via oxidative damage. This study investigated the stages of spermatogenesis susceptible to be targeted by Me-Pa exposure that impact on spermatozoa function and their ability to fertilize. Male mice were exposed to Me-Pa (20 mg/kg bw, i.p.) and spermatozoa from epididymis-vas deferens were collected at 7 or 28 days post-treatment (dpt) to assess the effects on maturing spermatozoa and spermatocytes, respectively. Spermatozoa were examined for DNA damage by nick translation (NT-positive cells) and SCSA (%DFI), lipoperoxidation (LPO) by malondialdehyde production, sperm function by spontaneous- and induced-acrosome reactions (AR), mitochondrial membrane potential (MMP) by using the JC-1 fluorochrome, and fertilization ability by an in vitro assay and in vivo mating. Alterations on DNA integrity (%DFI and NT-positive cells) in spermatozoa collected at 7 and 28 dpt, and decreases in sperm quality and induced-AR were observed; reduced MMP and LPO were observed at 7 dpt only. Negative correlations between LPO and sperm alterations were found. Altered sperm functional parameters evaluated either in vitro or in vivo were associated with reduced fertilization rates at both times. These results show that Me-Pa exposure of maturing spermatozoa and spermatocytes affects many sperm functional parameters that result in a decreased fertilizing capacity. Oxidative stress seems to be a likely mechanism of the detrimental effects of Me-Pa exposure in male germ cells.

Parathion alters incubation behavior of laughing gulls

Science.gov (United States)

White, D.H.; Mitchell, C.A.; Hill, E.F.

1983-01-01

One member of each pair of incubating laughing gulls at 9 nests was trapped, orally dosed with either 6 mg/kg parathion in corn oil or corn oil alone, and marked about the neck with red dye. Each nest was marked with a numbered stake and the treatment was recorded. A pilot study with captive laughing gulls had determined the proper dosage of parathion that would significantly inhibit their brain AChE activity (about 50% of normal) without overt signs of poisoning. After dosing, birds were released and the nests were observed for 2 1/2 days from a blind on the nesting island. The activities of the birds at each marked nest were recorded at 10-minute intervals. Results indicated that on the day of treatment there was no difference (P greater than 0.05, Chi-square test) in the proportion of time spent on the nest between treated and control birds. However, birds dosed with 6 mg/kg parathion spent significantly less time incubating on days 2 and 3 than did birds receiving only corn oil. By noon on the third day, sharing of nest duties between pair members in the treated group had approached normal, indicating recovery from parathion intoxication. These findings suggest that sublethal exposure of nesting birds to an organophosphate (OP) insecticide, such as parathion, may result in decreased nest attentiveness, thereby making the clutch more susceptible to predation or egg failure. Behavioral changes caused by sublethal OP exposure could be especially detrimental in avian species where only one pair member incubates or where both members are exposed in species sharing nest duties.

Hormonal responses and tolerance to cold of female quail following parathion ingestion

Science.gov (United States)

Rattner, B.A.; Sileo, L.; Scanes, C.G.

1982-01-01

Thirty-week-old female bobwhite quail (Colinus virginianus), maintained at 26 + 1?C, were provided diets containing 0,25, or 100 ppm parathion ad libitum. After 10 days, birds were exposed to mild cold (6 + 1?C) for 4,8, 12, 24, or 48 hr. Brain acetylcholinesterase activity was inhibited in a dose-dependent manner in birds receiving 25 and 100 ppm parathion. Body weight, egg production, and plasma luteinizing hormone and progesterone concentrations were reduced in birds receiving 100 ppm parathion compared with other groups. Cold exposure did not alter plasma corticosterone levels in the 0- and 25-ppm parathion groups, but a two- to five fold elevation of plasma corticosterone was observed in birds fed 100 ppm parathion. These findings indicate that (i) short-term ingestion of parathion can impair reproduction possibly by altering gonadotropin or steroid secretion, and (ii) tolerance to cold may be reduced following ingestion of this organophosphate.

Novel approaches to mitigating parathion toxicity: targeting cytochrome P450-mediated metabolism with menadione.

Science.gov (United States)

Jan, Yi-Hua; Richardson, Jason R; Baker, Angela A; Mishin, Vladimir; Heck, Diane E; Laskin, Debra L; Laskin, Jeffrey D

2016-08-01

Accidental or intentional exposures to parathion, an organophosphorus (OP) pesticide, can cause severe poisoning in humans. Parathion toxicity is dependent on its metabolism by the cytochrome P450 (CYP) system to paraoxon (diethyl 4-nitrophenyl phosphate), a highly poisonous nerve agent and potent inhibitor of acetylcholinesterase. We have been investigating inhibitors of CYP-mediated bioactivation of OPs as a method of preventing or reversing progressive parathion toxicity. It is well recognized that NADPH-cytochrome P450 reductase, an enzyme required for the transfer of electrons to CYPs, mediates chemical redox cycling. In this process, the enzyme diverts electrons from CYPs to support chemical redox cycling, which results in inhibition of CYP-mediated biotransformation. Using menadione as the redox-cycling chemical, we discovered that this enzymatic reaction blocks metabolic activation of parathion in rat and human liver microsomes and in recombinant CYPs important to parathion metabolism, including CYP1A2, CYP2B6, and CYP3A4. Administration of menadione to rats reduces metabolism of parathion, as well as parathion-induced inhibition of brain cholinesterase activity. This resulted in inhibition of parathion neurotoxicity. Menadione has relatively low toxicity and is approved by the Food and Drug Administration for other indications. Its ability to block parathion metabolism makes it an attractive therapeutic candidate to mitigate parathion-induced neurotoxicity. © 2016 New York Academy of Sciences.

EFECTO DE LA CONCENTRACIÓN DEL METIL PARATIÓN Y EL EXTRACTO DE LEVADURA COMO FACTORES DE SELECCIÓN DE MICROORGANISMOS DEGRADADORES DEL PESTICIDA A PARTIR DE SUELOS CONTAMINADOS Effect of Methyl Parathion Concentration and Yeast Extract as Factors for Selecting Pesticide Degrading Microorganisms from Polluted Soils

Directory of Open Access Journals (Sweden)

L. R. Botero

2011-12-01

Full Text Available El aislamiento y cultivo de microorganismos con capacidades para degradar los contaminantes ambientales es importante para implementar planes de biorremediación. En este estudio se evaluó el efecto del extracto de levadura tanto en la capacidad de asimilación microbiana del pesticida organofosforado metil paratión, como en los procesos de aislamiento de microorganismos útiles para de degradar este pesticida. Los microorganismos evaluados fueron obtenidos de suelo fresco fumigado históricamente con este pesticida. Los ensayos se efectuaron con medios sólidos definidos enriquecidos con metil paratión (0-60 mg L-1 y extracto de levadura (0-0.5 g L -1. Se encontró que los microorganismos fueron capaces de asimilar hasta 5 mg L -1 del metil paratión en ausencia de extracto de levadura sin evidenciar efectos tóxicos. La capacidad de asimilación aumentó a 10 mg L-1 en los cultivos enriquecidos con 0.5 g L-1 de extracto de levadura. El extracto de levadura en las dosis usadas no afectó el aislamiento de microorganismos. Sin embargo, el aislamiento por siembra directa en medios enriquecidos con metil paratión como única fuente de carbono se dificultó por el aporte de la materia orgánica del suelo que permitió el crecimiento de cepas tolerantes sin capacidad para degradar el pesticida.Isolation and culture of microorganisms with capacity to degrade environmental pollutants are important for implementing bioremediation plans. This study is an evaluation of the yeast extract effect on both the microbial capacity to assimilate the organo-phosphorous pesticide methyl parathion and the isolation processes of microorganisms useful for degrading this pesticide. Microorganisms evaluated were obtained from fresh soil historically fumigate with this pesticide. Trials were conducted with defined solid means enriched with methyl parathion (0-60 mg L-1 and yeast extract (0-0.5 g L-1. It was found that microorganisms were able to assimilate up to 5

Genetic damage caused by methyl-parathion in mouse spermatozoa is related to oxidative stress

International Nuclear Information System (INIS)

Pina-Guzman, B.; Solis-Heredia, M.J.; Rojas-Garcia, A.E.; Uriostegui-Acosta, M.; Quintanilla-Vega, B.

2006-01-01

Organophosphorous (OP) pesticides are considered genotoxic mainly to somatic cells, but results are not conclusive. Few studies have reported OP alterations on sperm chromatin and DNA, and oxidative stress has been related to their toxicity. Sperm cells are very sensitive to oxidative damage which has been associated with reproductive dysfunctions. We evaluated the effects of methyl-parathion (Me-Pa; a widely used OP) on sperm DNA, exploring the sensitive stage(s) of spermatogenesis and the relationship with oxidative stress. Male mice (10-12-weeks old) were administered Me-Pa (3-20 mg/kg bw/i.p.) and euthanized at 7- or 28-days post-treatment. Mature spermatozoa were obtained and evaluated for chromatin structure through SCSA (Sperm Chromatin Structure Assay; DNA Fragmentation Index parameters: Mean DFI and DFI%) and chromomycin-A 3 (CMA 3 )-staining, for DNA damage through in situ-nick translation (NT-positive) and for oxidative stress through lipid peroxidation (LPO; malondialdehyde production). At 7-days post-treatment (mature spermatozoa when Me-Pa exposure), dose-dependent alterations in chromatin structure (Mean DFI and CMA 3 -staining) were observed, as well as increased DNA damage, from 2-5-fold in DFI% and NT-positive cells. Chromatin alterations and DNA damage were also observed at 28-days post-treatment (cells at meiosis at the time of exposure); suggesting that the damage induced in spermatocytes was not repaired. Positive correlations were observed between LPO and sperm DNA-related parameters. These data suggest that oxidative stress is related to Me-Pa alterations on sperm DNA integrity and cells at meiosis (28-days post-treatment) and epididymal maturation (7-days post-treatment) are Me-Pa targets. These findings suggest a potential risk of Me-Pa to the offspring after transmission

Efecto del enriquecimiento con nutrientes en la degradación de clorpirifos, malatión y metil paratión Inorganic nutrients effect addition over the chlorpyrifos, malathion and methyl parathion degradation

Directory of Open Access Journals (Sweden)

S. A. Upegui

2011-01-01

Full Text Available Con el fin de evaluar el efecto del enriquecimiento con nutrientes (una sal de fósforo o un fertilizante comercial con N, P y K como alternativa para mejorar la capacidad de degradación de los microorganismos en una matriz sólida, contaminada con los pesticidas organofosforados: clorpirifos, malatión y metil paratión, se realizaron experimentos de cultivo bajo condiciones controladas de oscuridad, temperatura y humedad por 30 días. En todos los tratamientos hubo degradación de los pesticidas; sin embargo, en el tratamiento con fósforo los tiempos para degradar el clorpirifos y el metil paratión fueron mayores. La presencia de los pesticidas no generó efectos tóxicos detectables sobre la microflora en ninguno de los tratamientos evaluados. La actividad biológica de las matrices no presentó una relación directa con la capacidad de degradación.In order to evaluate the effect of inorganic nutrient addition (phosphorus or commercial fertilizer over the microbial degradation capacity present in a solid matrix contaminated with chlorpyrifos, malathion and methyl parathion, microcosms assays were held under controlled conditions of light, moisture and temperature for 30 days. Results showed that even though three treatments microorganisms were able to degrade the three organophosphorus pesticides, microorganisms of phosphorus-enrichment treatment were less efficient to degrade Chlorpyrifos and Methyl Parathion than microorganisms of Fertilizer-enrichment treatment. It was not observed a direct relation between mineralization and microbial pesticides degradation capacity. The microbial activity was not affected by the presence of organophosphorus pesticides.

Novel approaches to mitigating parathion toxicity: targeting cytochrome P450–mediated metabolism with menadione

Science.gov (United States)

Jan, Yi-Hua; Richardson, Jason R.; Baker, Angela A.; Mishin, Vladimir; Heck, Diane E.; Laskin, Debra L.; Laskin, Jeffrey D.

2016-01-01

Accidental or intentional exposures to parathion, an organophosphorus (OP) pesticide, can cause severe poisoning in humans. Parathion toxicity is dependent on its metabolism by the cytochrome P450 (CYP) system to paraoxon (diethyl 4-nitrophenyl phosphate), a highly poisonous nerve agent and potent inhibitor of acetylcholinesterase (AChE). We have been investigating inhibitors of CYP-mediated bioactivation of OPs as a method of preventing or reversing progressive parathion toxicity. It is well recognized that NADPH–cytochrome P450 reductase, an enzyme required for the transfer of electrons to CYPs, mediates chemical redox cycling. In this process, the enzyme diverts electrons from CYPs to support chemical redox cycling, which results in inhibition of CYP-mediated biotransformation. Using menadione as the redox-cycling chemical, we discovered that this enzymatic reaction blocks metabolic activation of parathion in rat and human liver microsomes and in recombinant CYPs important to parathion metabolism, including CYP1A2, CYP2B6, and CYP3A4. Administration of menadione to rats reduces metabolism of parathion, as well as parathion-induced inhibition of brain cholinesterase activity. This resulted in inhibition of parathion neurotoxicity. Menadione has relatively low toxicity and is approved by the FDA for other indications. Its ability to block parathion metabolism makes it an attractive therapeutic candidate to mitigate parathion-induced neurotoxicity. PMID:27441453

Bioaccumulation of methyl parathion and its toxicology in several species of the freshwater community in Ignacio Ramirez dam in Mexico.

Science.gov (United States)

De La Vega Salazar, M Y; Tabche, L M; García, C M

1997-10-01

Environmental contamination by pesticides, including the presence of chemical residues in aquatic wildlife, is a widespread ecological problem. Methyl parathion (MP), a widely used organophosphorate insecticide, is a potent neurotoxic in both vertebrates and invertebrates. The effect of a subchronic exposure to MP in aquatic organisms was evaluated in a natural ecosystem measuring acetyl cholinesterase (AChE) and gamma glutamil transpeptidase (GGT) activity. Two samples were conducted. Physicochemical characterization was done at each sampling time and organisms were collected. MP and metabolite 4-nitrophenol (4-NP) concentrations were measured in water sediment and organisms. The major differences in physical features between season were an increase of turbidity and salinity and depletion of dissolved oxygen in the rainy season. MP and 4-NP are bioconcentrated in organisms in response to environmental stress. MP concentration was measured in different size/age and reproductive stages separately. A significant concentration in reproductive tissues (plants)/unborn progeny (animals) was always found, and this can affect egg viability. The metabolite 4-NP is bioaccumulated and is toxic because it causes an increase of AChE activity. GGT activity was higher than that in controls. The increase in enzymatic activity provides a detoxification mechanism from chronic sublethal exposure, when hepatic glutation depletion occurs, and may be an indicator of liver damage.

Electrochemical Sensor for Determination of Parathion Based on Electropolymerization Poly(Safranine Film Electrode

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Xingyuan Liu

2011-01-01

Full Text Available Parathion has been determined with voltammetric technique based on a novel sensor fabricated by electropolymerization of safranine on a glassy carbon electrode (GCE. The electrochemical behavior of poly(safranine film electrode and its electrocatalytic activity toward parathion were studied in detail by cyclic voltammetry (CV and linear sweep voltammetry (LSV. All experimental parameters were optimized, and LSV was proposed for its determination. In optimal working conditions, the reduction current of parathion at this poly(safranine-modified electrode exhibited a good linear relationship with parathion concentration in the range of 3.43×10−8 to 3.43×10−5 mol L−1. The detection limit was 1.0×10−8 mol L−1. The high sensitivity and selectivity of the sensor were demonstrated by its practical application for the determination of trace amounts of parathion in fruit samples.

Volatilization of parathion and chlorothalonil after spraying onto a potato crop

NARCIS (Netherlands)

Berg, van den F.; Bor, G.; Smidt, R.A.; Peppel-Groen, van de A.E.; Smelt, J.H.; Müller, T.; Maurer, T.

1995-01-01

At fourteen times after application of parathion and chlorothalonil to a potato crop their rates of volatilization were determined by the aerodynamic and Bowen ratio methods. The highest volatilization rate of parathion occurred shortly after application. In the first hours after application its

para-Sulfonatocalix[6]arene-modified silver nanoparticles electrodeposited on glassy carbon electrode: preparation and electrochemical sensing of methyl parathion.

Science.gov (United States)

Bian, Yinghui; Li, Chunya; Li, Haibing

2010-05-15

In this paper, a new electrochemical sensor, based on modified silver nanoparticles, was fabricated using one-step electrodeposition approach. The para-sulfonatocalix[6]arene-modified silver nanoparticles coated on glassy carbon electrode (pSC(6)-Ag NPs/GCE) was characterized by attenuated total reflection IR spectroscopy (ATR-IR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), etc. The pSC(6) as the host are highly efficient to capture organophosphates (OPs), which dramatically facilitates the enrichment of nitroaromatic OPs onto the electrochemical sensor surface. The combination of the host-guest supramolecular structure and the excellent electrochemical catalytic activities of the pSC(6)-Ag NPs/GCE provides a fast, simple, and sensitive electrochemical method for detecting nitroaromatic OPs. In this work, methyl parathion (MP) was used as a nitroaromatic OP model for testing the proposed sensor. In comparison with Ag NPs-modified electrode, the cathodic peak current of MP was amplified significantly. Differential pulse voltammetry was used for the simultaneous determination of MP. Under optimum conditions, the current increased linearly with the increasing concentration of MP in the range of 0.01-80microM, with a detection limit of 4.0nM (S/N=3). The fabrication reproducibility and stability of the sensor is better than that of enzyme-based electrodes. The possible underlying mechanism is discussed.

The degradation of [14C] parathion in two Brazilian soils

International Nuclear Information System (INIS)

Andrea, M.M. de; Lord, K.A.; Bromilow, R.H.; Ruegg, E.F.

1980-01-01

Loss of [ 14 C] parathion from two Brazilian soils was studied by measuring the parathion which could be extracted by a mixture of hexane and propanol and the 14 CO 2 evolved. Recovery of unchanged parathion decreased faster in the soil richer in organic matter (soil 1) from which more radiocarbon was evolved as CO 2 than from the soil poorerin organic matter (soil 2). Evolution of CO 2 from soil 1 decreased rapidly when the soil dried out but little effect of moisture content was observed in soil 2. Radiocarbon remaining in the soils was assayed by combustion after 234 days and the total recovered in soil 1 was 95.6% and, in soil 2,78.7%, sufficient to give almost complete recovery from both soils. (Author) [pt

Enhancement of parathion toxicity to quail by heat and cold exposure

Science.gov (United States)

Rattner, B.A.; Becker, J.M.; Nakatsugawa, T.

1987-01-01

Effects of ambient temperature on the acute oral toxicity of parathion were investigated in Japanese quail (Coturnix japonica) maintained at thermoneutral temperature (26.degree. C) or exposed to elevated (37.degree. C) or reduced (4.degree. C) temperatures commonly encountered by free-ranging wild birds. Based upon estimates of the median lethal dosage, there was up to a two-fold enhancement of parathion toxicity in birds chronically exposed to heat or cold. Twenty-four hours after administration of a low dosage (4 mg/kg body wt, po), there was markedly greater cholinesterase inhibition in surviving heat-exposed quail compared with those reared at 26.degree. C (e.g., brain acetylcholinesterase depression of 42% versus 12%). There were no differences in hepatic activities of parathion oxidase, paraoxonase, or paraoxon deethylase which could account for greater toxicity to chronically heat-exposed birds. In contrast, 4 mg parathion/kg wt elicited less plasma cholinesterase inhibition in cold-exposed quail compared to thermoneutral controls (e.g., birds is substantially influenced by environmental temperature.

Fungal bio-degradation of 14C-parathion

International Nuclear Information System (INIS)

Mohamed, G. A.; Abo-El Seoud, M. A.

2012-12-01

1 4 'C-parathion (670 Bq) was applied to mineral salt medium (MSM) to examine and evaluate its biodegradation by some fungi. The studied isolates were Alternaria alternate, Fusarium oxysporim and trichoderma viride. The inoculated media were incubated at 30 o C for periods of 2, 4, 6 and 8 days. Ta each interval, mycelia were separated from nutrient solution and extracted for its radioactivity. However, non extractable compounds were liberated by combustion. Quantitative and qualitative analysis were carried out for the radioactive compound in mycelia l extracts and residues as well as the fungal culture filtrate. Balance sheet for total recovered radioactive compounds was concluded 1 4 'C-parathion metabolism was expressed as original compound, polar metabolite, non polar metabolites and non extractable residues and then degradation rate was calculated. araesults indicated that there was continuous penetration for the radioactivity into mycelia tissues and the maximum, accumulation was recorded by Fusarium Oxysporium. The fungi under investigation showed considerable variations regarding their capacity to degrade the radioactive pesticide. Trichoderma viride exhibited the maximum capability to catabolism the the 1 4C -parathion as it exerted the maximum degradation rate. Fusarium and Alternate alter nata showed less degradation rates for the 1 4C - pesticide under investigation. (Author)

Simultaneous Determination of Parathion, Malathion, Diazinon, and Pirimiphos Methyl in Dried Medicinal Plants Using Solid-Phase Microextraction Fibre Coated with Single-Walled Carbon Nanotubes

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Reza Ahmadkhaniha

2012-01-01

Full Text Available A reliable and sensitive headspace solid-phase microextraction gas chromatography-mass spectrometry method for simultaneous determination of different organophosphorus pesticides in dried medicinal plant samples is described. The analytes were extracted by single-walled carbon nanotubes as a new solid-phase microextraction adsorbent. The developed method showed good performance. For diazinon and pirimiphos methyl calibration, curves were linear (r2≥0.993 over the concentration ranges from 1.5 to 300 ng g−1, and the limit of detection at signal-to-noise ratio of 3 was 0.3 ng g−1. For parathion and malathion, the linear range and limit of detection were 2.5–300 (r2≥0.991 and 0.5 ng g−1, respectively. In addition, a comparative study between the single-walled carbon nanotubes and a commercial polydimethylsiloxane fibre for the determination of target analytes was carried out. Single-walled carbon nanotubes fibre showed higher extraction capacity, better thermal stability (over 350∘C, and longer lifespan (over 250 times than the commercial polydimethylsiloxane fibre. The developed method was successfully applied to determine target organophosphorus pesticides in real samples.

Genetically engineered Pseudomonas putida X3 strain and its potential ability to bioremediate soil microcosms contaminated with methyl parathion and cadmium.

Science.gov (United States)

Zhang, Rong; Xu, Xingjian; Chen, Wenli; Huang, Qiaoyun

2016-02-01

A multifunctional Pseudomonas putida X3 strain was successfully engineered by introducing methyl parathion (MP)-degrading gene and enhanced green fluorescent protein (EGFP) gene in P. putida X4 (CCTCC: 209319). In liquid cultures, the engineered X3 strain utilized MP as sole carbon source for growth and degraded 100 mg L(-1) of MP within 24 h; however, this strain did not further metabolize p-nitrophenol (PNP), an intermediate metabolite of MP. No discrepancy in minimum inhibitory concentrations (MICs) to cadmium (Cd), copper (Cu), zinc (Zn), and cobalt (Co) was observed between the engineered X3 strain and its host strain. The inoculated X3 strain accelerated MP degradation in different polluted soil microcosms with 100 mg MP kg(-1) dry soil and/or 5 mg Cd kg(-1) dry soil; MP was completely eliminated within 40 h. However, the presence of Cd in the early stage of remediation slightly delayed MP degradation. The application of X3 strain in Cd-contaminated soil strongly affected the distribution of Cd fractions and immobilized Cd by reducing bioavailable Cd concentrations with lower soluble/exchangeable Cd and organic-bound Cd. The inoculated X3 strain also colonized and proliferated in various contaminated microcosms. Our results suggested that the engineered X3 strain is a potential bioremediation agent showing competitive advantage in complex contaminated environments.

Degradation of the insecticide ethyl parathion in different environmental matrices by gamma radiation from Cobalt-60

International Nuclear Information System (INIS)

Luchini, Luiz Carlos

1995-01-01

This work studies the use of gamma radiation from cobalt-60 to induce parathion degradation in different matrices, as well as, quantified GC-NPD and identified by GC-MS, the radiolysis resulting products. Results show that the insecticide was completely degraded in aqueous solution after treatment with 1.0 kGy dosis in a dosis rate of 3.12 kGy h -1 . In methanol, parathion was completely degraded only with 30 kGy at 3.12 kGy h -1 . The metabolites detected after radiolysis were the same formed by biological degradation, i.e, p-nitrophenol, p-aminophenol, paraoxon and aminoparathion. The gamma radiation also degraded paraoxon which is the most toxic metabolite of parathion. It was verified that, not only the total radiation, but also the dosis rate supplied to the aqueous solution had a significant effect on the insecticide degradation, and the formation of metabolites occurred in a selective way respecting the dosis and dosis rate. Otherwise, the gamma radiation did almost not degraded the parathion adsorbed in solid matrices as rice, moist and dry soil, even using dosis of 5,30 and 50 kGy, respectively. The parathion yield and the dosis of gamma radiation needed for 50% reduction of the insecticide initial concentration in aqueous solution were also calculated and presented. Thus, it was verified that irradiation of parathion besides to be an important instrument for environmental decontamination of this pesticide in aqueous matrix, it allows the production of parathion metabolites for ecotoxicological studies. (author)

Interactions Between Agricultural Chemicals and the Soil Microflora and Their Effects on {sup 14}C-Parathion Metabolism in Cranberry Soils

Energy Technology Data Exchange (ETDEWEB)

Ferris, I. G.; Lichtenstein, E. P. [Department of Entomology, University of Wisconsin, Madison, Wisconsin 53706 (United States)

1981-05-15

Full text: The fate of {sup 14}C-parathion in a loam and ''cranberry soil'' was investigated utilizing a closed system to enable monitoring of {sup 14}CO{sub 2} evolution, and to obtain a total {sup 14}C balance. Soils were treated with {sup 14}C-parathion at rates equivalent to about 3 ppm and incubated at 23 ± 2°C. After 3 weeks of soil incubation differences in the persistence of {sup 14}C-parathion were evident: 76% of applied radiocarbon remained as unchanged parathion in loam soil compared with only 4% in a cranberry soil; conversely, {sup 14}C-degradation products amounted to 26% and 91% of applied radiocarbon, respectively. Interactions were found to occur between fungicides and the biodegradation of {sup 14}C-(ring)-parathion in cranberry soil. Captafol (Difolatan® inhibited the metabolism of {sup 14}C-parathion. The inhibition was a linear function of the applied captafol concentration with a no effect concentration of 1 ppm. On the other hand, 100 ppm of Manzate®(maneb) or Benlate® (benomyl) altered the pathway of {sup 14}C-parathion degradation in favour of bound {sup 14}C-residues. In soil-free medium inoculated with cranberry soil microorganisms {sup 14}C-(ring)- parathion was degraded within 4 days principally to volatile {sup 14}C-compounds (presumably {sup 14}CO{sub 2}). On the -contrary, no degradation of {sup 14}C-parathion occurred in an inoculated medium that also contained a 100-ppm benomyl suspension, apparently benomyl inhibited the hydrolysis/oxidation of {sup 14}C-parathion. Soil amendments of 100 ppm nitrogen (N) as (NH{sub 4}){sub 2}SO{sub 4}, or to a lesser extent KNO{sub 3}, inhibited the metabolism of {sup 14}C-( ring)-parathion to {sup 14}CO{sub 2}. In summary, some agricultural chemicals have an effect on parathiondegrading microorganisms resulting in an increase in bound {sup 14}C-residues and an increased persistence of toxic parathion residues.

The reactivation effect of pralidoxime in human blood on parathion and paraoxon–induced cholinesterase inhibition

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Mahvash Jafari

2006-03-01

Full Text Available In this investigation the reactivation of cholinesterases by pralidoxime in parathion and paraoxon intoxication in plasma and erythrocytes were studied. For this purpose, human plasma and erythrocytes were incubated with various concentrations of parathion (0.1-10 µM and paraoxon (0.03-0.3 µM at 37 oC for 10 min. Then, pralidoxime (10-300 µM was added to the samples and incubated for 10 min before cholinesterases assay. The results showed that effects of parathion and paraoxon were dose dependent. These agents inhibited more than 85% of butyrylcholinesterase (BChE and acetylcholinesterase (AChE activity and the inhibitory effect of paraoxon was 10 times more than parathion. BChE activity was significantly higher than the control at 100 µM of pralidoxime and it reduced inhibitory effects of parathion to less than 50% and of paraoxon to 42% of control. When pralidoxime (10 µM was added to erythrocytes, the inhibitory effects of two organophosphates were reduced to less than 15%. At higher concentrations of pralidoxime (>100 µM, both BChE and AChE activities were inhibited.

Involvement of glial cells in the neurotoxicity of parathion and chlorpyrifos

International Nuclear Information System (INIS)

Zurich, M.-G.; Honegger, P.; Schilter, B.; Costa, L.G.; Monnet-Tschudi, F.

2004-01-01

An in vitro model, the aggregating brain cell culture of fetal rat telencephalon, has been used to investigate the influence of glial cells on the neurotoxicity of two organophosphorus pesticides (OPs), chlorpyrifos and parathion. Mixed-cell aggregate cultures were treated continuously for 10 days between DIV 5 and 15. Parathion induced astrogliosis at concentration at which MAP-2 immunostaining, found here to be more sensitive than neuron-specific enzyme activities, was not affected. In contrast, chlorpyrifos induced a comparatively weak gliotic reaction, and only at concentrations at which neurons were already affected. After similar treatments, increased neurotoxicity of parathion and chlorpyrifos was found in aggregate cultures deprived of glial cells. These results suggest that glial cells provide neuroprotection against OPs toxicity. To address the question of the difference in toxicity between parathion and chlorpyrifos, the toxic effects of their leaving groups, p-nitrophenol and trichloropyridinol, were studied in mixed-cell aggregates. General cytotoxicity was more pronounced for trichloropyridinol and both compounds had similar toxic effects on neuron-specific enzyme activities. In contrast, trichloropyridinol induced a much stronger decrease in glutamine synthetase activity, the enzymatic marker of astrocytes. Trichloropyridinol may exert a toxic effect on astrocytes, compromising their neuroprotective function, thus exacerbating the neurotoxicity of chlorpyrifos. This is in line with the suggestion that glial cells may contribute to OPs neurotoxicity, and with the view that OPs may exert their neurotoxic effects through different mechanisms

Impact of parathion exposure on some biochemical parameters in rabbit as a non target organism

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Nagat Aly

2015-03-01

Conclusion: The results indicated that changes in body and organ weights have been used as indicators of adverse effects of parathion and also alteration in tested enzymes activity can be used as relevant biomarkers for monitoring toxicity due to parathion exposure in non target organisms.

Comparative effects of parathion and chlorpyrifos on endocannabinoid and endocannabinoid-like lipid metabolites in rat striatum.

Science.gov (United States)

Liu, Jing; Parsons, Loren; Pope, Carey

2015-09-01

Parathion and chlorpyrifos are organophosphorus insecticides (OPs) that elicit acute toxicity by inhibiting acetylcholinesterase (AChE). The endocannabinoids (eCBs, N-arachidonoylethanolamine, AEA; 2-arachidonoylglycerol, 2AG) are endogenous neuromodulators that regulate presynaptic neurotransmitter release in neurons throughout the central and peripheral nervous systems. While substantial information is known about the eCBs, less is known about a number of endocannabinoid-like metabolites (eCBLs, e.g., N-palmitoylethanolamine, PEA; N-oleoylethanolamine, OEA). We report the comparative effects of parathion and chlorpyrifos on AChE and enzymes responsible for inactivation of the eCBs, fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), and changes in the eCBs AEA and 2AG and eCBLs PEA and OEA, in rat striatum. Adult, male rats were treated with vehicle (peanut oil, 2 ml/kg, sc), parathion (27 mg/kg) or chlorpyrifos (280 mg/kg) 6-7 days after surgical implantation of microdialysis cannulae into the right striatum, followed by microdialysis two or four days later. Additional rats were similarly treated and sacrificed for evaluation of tissue levels of eCBs and eCBLs. Dialysates and tissue extracts were analyzed by LC-MS/MS. AChE and FAAH were extensively inhibited at both time-points (85-96%), while MAGL activity was significantly but lesser affected (37-62% inhibition) by parathion and chlorpyrifos. Signs of toxicity were noted only in parathion-treated rats. In general, chlorpyrifos increased eCB levels while parathion had no or lesser effects. Early changes in extracellular AEA, 2AG and PEA levels were significantly different between parathion and chlorpyrifos exposures. Differential changes in extracellular and/or tissue levels of eCBs and eCBLs could potentially influence a number of signaling pathways and contribute to selective neurological changes following acute OP intoxications. Copyright © 2015 Elsevier Inc. All rights reserved.

Effects on parathion on the ecology of a eutrophic aquatic ecosystem: limnocorral experiment

International Nuclear Information System (INIS)

Gasith, A.; Perry, A.S.; Mozel, Y.; Albright, J.L.

1983-01-01

Repetitive exposure of a eutrophic fish pond ecosystem, enclosed in limnocorrals, to 30 ppb parathion resulted in elimination of the potentially dominant zooplankton species, Moina micrura. Consequently, the populations of the rotifers Brachionus and Asplanchna markedly increased. Changes in the zooplankton composition and abundance were followed by increased fluctuations in phytoplankton biomass, phytoplankton photosynthesis, plankton respiration and community metabolism. Similar responses to parathion treatment were observed in previous studies under fish pond conditions. In the presence of fish the effect of parathion on the ecosystem was generally less pronounced and not uniform. The collapse of the zooplankton community and the rapid changes in limnological conditions in the control (untreated) limnocorrals severely limited the duration of the experiment. The results suggest that under eutrophic conditions, small enclosures may be useful for evaluation of the effect of toxicants on the ecosystem only in short term experiments with short lived chemicals. (author)

Effects of GST Polymorphism on Ameliorative Effect of Curcumin and Carvacrol against DNA Damage Induced by Combined Treatment of Malathion and Parathion

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Neeraj Kumar

2016-04-01

Full Text Available Background: Organophosphorus pesticides has been widely used in agriculture fields to control various crop insects and their extensive use pose human life at threat because of their adverse effects on human health. In this study, we checked the effects of GST polymorphism on ameliorative effect of curcumin and carvacrol against DNA damages. Methods: Comet assay was used to assess the DNA damage and results were expressed as Tail moment. Heparinised fresh blood from healthy individuals was treated with combined concentration of malathion and parathion (i.e. 30 µg/ml of malathion and 2.5 µg/ml of parathion in presence of combination of curcumin and carvacrol (25 µg/ml curcumin + 2.5 µg/ml carvacrol and 50 µg/ml curcumin + 5.0 µg/ml carvacrol in order to observe the ameliorative role of curcumin and carvacrol. Multiplex PCR was performed for GSTM1 and GSTT1 genotyping. Results: Curcumin in combination with carvacrol (i.e. 25 µg/ml curcumin + 2.5 µg/ml carvacrol and 50 µg/ml curcumin + 5.0 µg/ml carvacrol significantly reduced the DNA damage caused by combined action of malathion and parathion which supports their antigenotoxic property. No significant relationship of GSTT1 and GSTM1 polymorphism with genotoxicity of both the pesticides and antigenotoxic potential of curcumin and carvacrol was observed. Conclusion: Malathion and parathion were genotoxic in human PBL. Curcumin and carvacrol had an antigenotoxic effect against the malathion and parathion while there was not any significant effect of GSTT1 and GSTM1 polymorphism on genotoxicity of these pesticides and antigenotoxicity of curcumin and carvacrol.

Dynamics of penetration of 14C-labelled parathion in desert locust, Schistocerca gregaria Forskal

International Nuclear Information System (INIS)

Garg, A.K.; Bhatia, Parvathy; Sethi, G.R.

1991-01-01

Studies on the rate of disappearance of 14 C ring labelled parathion, after topical application on the mesosternum of desert locust, Schistocerca gregaria Forskal, indicated that penetration of the toxicant was linear and followed first order kinetics. The first order constant (k) for parathion on desert locust was 18.42x10 -2 per hr and half-life (Tsub(0.5)) was about 226 min. (author). 26 refs ., 1 fig

Homogeneous and heterogeneous catalysts of Fe3+, Co2+ and Cu2+ for the degradation of methyl parathion in diluted aqueous medium

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Cindy A. Vela-Monroy

2016-07-01

Full Text Available Degradation of pesticides (plaguicides, herbicides, fungicides, among others in aqueous media is a subject of great importance for ensuring the water quality into numerous hydric sources. This work reports the assessment of homogeneous (metal ion solutions and heterogeneous (oxides supported on alumina systems that are based on Fe3+, Co2+ y Cu2+, which were used as catalysts for oxidation (degradation of methyl parathion (a plaguicide in aqueous solution. Hydrogen peroxide was herein used as oxidizing molecule under mild condition of reaction (25 ºC and atmospheric pressure. The solids were characterized by X-ray diffraction (XRD and scanning electron microscopy (SEM. Fe3+/H2O2 (Fenton system was the most active homogeneous catalyst compared to Co2+/H2O2 and Cu2+/H2O2 systems. Solids catalysts such as cobalt, copper or iron oxides as well as mixed oxides supported on alumina were active at pH close to neutrality. Fe-Co-Cu/Al2O3, Co-Cu/Al2O3 and FeCo/Al2O3 mixed systems were solids with the highest catalytic activity. In addition, an important effect of the support (-Al2O3 on the reaction pH was observed, allowing to reach values close to that of the neutrality, and thus increasing the catalytic activity of both cobalt oxide and copper oxide species. These results allow advancing on a new pathway for searching catalysts to remove organophosphorous pesticides from residual waters.

Interactive toxicity of chlorpyrifos and parathion in neonatal rats: Role of esterases in exposure sequence-dependent toxicity

International Nuclear Information System (INIS)

Kacham, R.; Karanth, S.; Baireddy, P.; Liu, J.; Pope, C.

2006-01-01

We previously reported that sequence of exposure to chlorpyrifos and parathion in adult rats can markedly influence toxic outcome. In the present study, we evaluated the interactive toxicity of chlorpyrifos (8 mg/kg, po) and parathion (0.5 mg/kg, po) in neonatal (7 days old) rats. Rats were exposed to the insecticides either concurrently or sequentially (separated by 4 h) and sacrificed at 4, 8, and 24 h after the first exposure for biochemical measurements (cholinesterase activity in brain, plasma, and diaphragm and carboxylesterase activity in plasma and liver). The concurrently-exposed group showed more cumulative lethality (15/24) than either of the sequential dosing groups. With sequential dosing, rats treated initially with chlorpyrifos prior to parathion (C/P) exhibited higher lethality (7/23) compared to those treated with parathion before chlorpyrifos (P/C; 1/24). At 8 h after initial dosing, brain cholinesterase inhibition was significantly greater in the C/P group (59%) compared to the P/C group (28%). Diaphragm and plasma cholinesterase activity also followed a relatively similar pattern of inhibition. Carboxylesterase inhibition in plasma and liver was relatively similar among the treatment groups across time-points. Similar sequence-dependent differences in brain cholinesterase inhibition were also noted with lower binary exposures to chlorpyrifos (2 mg/kg) and parathion (0.35 mg/kg). In vitro and ex vivo studies compared relative oxon detoxification of carboxylesterases (calcium-insensitive) and A-esterases (calcium-sensitive) in liver homogenates from untreated and insecticide pretreated rats. Using tissues from untreated rats, carboxylesterases detoxified both chlorpyrifos oxon and paraoxon, while A-esterases only detoxified chlorpyrifos oxon. With parathion pretreatment, A-esterases still detoxified chlorpyrifos oxon while liver from chlorpyrifos pretreated rats had little apparent effect on paraoxon. We conclude that while neonatal rats are less

Competition of a parathion-hydrolyzing Flavobacterium with bacteria from ditch water in carbon-, nitrate- and phosphate-limited continuous cultures

NARCIS (Netherlands)

Sprenger, W.; Dijkstra, A.; Zwart, G.; Van Agterveld, M.P.; Van Noort, P.C.M.; Parsons, J.R.

2003-01-01

The effect of competition for macroelements with bacteria from ditch water on the parathion-hydrolyzing Flavobacterium sp. ATCC 27551 (FB) was investigated within mixed continuous cultures under carbon-, nitrate- or phosphate-limited conditions. The high initial rate of parathion hydrolysis

Removal of Parathion from Aqueous Media Through p-tert-Butylcalix[4]arene Based Modified Silica

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Sibghatullah Memon

2013-12-01

Full Text Available This study explores, adsorption efficiency of p-tert-butylcalix[4]arene based modified silica to remove parathion from aqueous environment. The adsorption parameters, i.e. pH, concentration of pesticide solution, contact time and adsorbent dosage were optimized, as 10, 1 mg L-1, 40 min and 0.04 g, respectively. Langmuir, Freundlich and Dubinin-Radushkevich (D-R isotherm models were used to evaluate the adsorption mechanism. Adsorption constants values of these models suggest that the adsorption of parathion is favorable and were found to be best fit with Freundlich isotherm. From the kinetic study it can be predicted that adsorption of parathion follows Ho and McKay model (pseudo-second order. Thermodynamic parameters, enthalpy (ΔH, entropy (ΔS and Gibbs free energy (ΔG have also been evaluated and were found as -132.25, 0.45, -4.14 Jmol-1, respectively.

Effect of rice straw on the degradation of 14C-parathion in flooded alluvial soil

International Nuclear Information System (INIS)

Rajaram, K.P.; Sethunathan, N.

1975-01-01

Organic matter, either native or applied, influences the persistence of soil-applied pesticides. The effect of rice straw on the metabolism of parathion in an alluvial soil under flooded condition was investigated. Residues were extracted from the soil at periodic intervals after application of ethoxy 14 C-parathion to rice straw amended and unamended soil employing chloroform-diethyl ether. The radioactivity in the solvent and water fractions were estimated. The activity in the solvent phase decreased more rapidly in the rice straw amended than in unamended soil indicating enhanced degradation of parathion by rice straw amendment. The autoradiograph of thin layer chromatograms of solvent phase revealed the rapid formation of aminoparathion and an unidentified metabolite possessing P-S bond and ethoxy label in amended soil within 3 days. A polar unidentified metabolite was detected in the water phase of the unamended soil at 14 days. (author)

The Effect of Parathion on Red Blood Cell Acetylcholinesterase in the Wistar Rat

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Naofumi Bunya

2016-01-01

Full Text Available Organophosphorus (OP pesticide poisoning is a significant problem worldwide. Research into new antidotes for these acetylcholinesterase inhibitors, and even optimal doses for current therapies, is hindered by a lack of standardized animal models. In this study, we sought to characterize the effects of the OP pesticide parathion on acetylcholinesterase in a Wistar rat model that included comprehensive medical care. Methods. Male Wistar rats were intubated and mechanically ventilated and then poisoned with between 20 mg/kg and 60 mg/kg of intravenous parathion. Upon developing signs of poisoning, the rats were treated with standard critical care, including atropine, pralidoxime chloride, and midazolam, for up to 48 hours. Acetylcholinesterase activity was determined serially for up to 8 days after poisoning. Results. At all doses of parathion, maximal depression of acetylcholinesterase occurred at 3 hours after poisoning. Acetylcholinesterase recovered to nearly 50% of baseline activity by day 4 in the 20 mg/kg cohort and by day 5 in the 40 and 60 mg/kg cohorts. At day 8, most rats’ acetylcholinesterase had recovered to roughly 70% of baseline. These data should be useful in developing rodent models of acute OP pesticide poisoning.

Degradation of 14C-parathion 'in vitro' by microorganisms isolated from a gley humic soil

International Nuclear Information System (INIS)

Andrea, M.M. de; Ruegg, E.F.

1982-01-01

It was determined 'in vitro' the degradation of Parathion by a bacterium and a fungus isolated from a sample of Gley Humic soil previously treated with repeated applications of the insecticide. In a qualitative colorimetric assay hydrolisis of parathion to p-nitrophenol just the bacterium gave a positive answer. In quantitative assays of 14 C-parathion degradation in culture media containing both microorganisms, organic solvents extractions resulted in organic and aqueous phases, which were analysed by liquid scintillation counting and thin-layer chromatography. In a mineral salts medium plus buffer, the bacterium and the fungus behaved differently from the control, because part of the 14 C-insecticide was metabolized to, at least, one metabolite and besides, the microorganisms presented smaller percentages of total recovery. The largest percentage of the radio carbon recovery from the extracts of the medium containing the fungus plus extract of yeast, was obtained from the aqueous phase and the existence of other metabolite was demonstrated by chromatograms of the organic phase. (Author) [pt

Rapid biodegradation of organophosphorus pesticides by Stenotrophomonas sp. G1

International Nuclear Information System (INIS)

Deng, Shuyan; Chen, Yao; Wang, Daosheng; Shi, Taozhong; Wu, Xiangwei; Ma, Xin; Li, Xiangqiong; Hua, Rimao; Tang, Xinyun; Li, Qing X.

2015-01-01

Highlights: • Stenotrophomonas sp. G1 was isolated from chlorpyrifos contaminated sludge. • Strain G1 is closest to Stenotrophomonas acidaminiphila. • Strain G1 can efficiently degrade 8 organophosphorus pesticides (OPs). • Intracellular methyl parathion hydrolase is responsible for the OP degradation. • Three factors were orthogonally optimized for degradation of methyl parathion. - Abstract: Organophosphorus insecticides have been widely used, which are highly poisonous and cause serious concerns over food safety and environmental pollution. A bacterial strain being capable of degrading O,O-dialkyl phosphorothioate and O,O-dialkyl phosphate insecticides, designated as G1, was isolated from sludge collected at the drain outlet of a chlorpyrifos manufacture plant. Physiological and biochemical characteristics and 16S rDNA gene sequence analysis suggested that strain G1 belongs to the genus Stenotrophomonas. At an initial concentration of 50 mg/L, strain G1 degraded 100% of methyl parathion, methyl paraoxon, diazinon, and phoxim, 95% of parathion, 63% of chlorpyrifos, 38% of profenofos, and 34% of triazophos in 24 h. Orthogonal experiments showed that the optimum conditions were an inoculum volume of 20% (v/v), a substrate concentration of 50 mg/L, and an incubation temperature in 40 °C. p-Nitrophenol was detected as the metabolite of methyl parathion, for which intracellular methyl parathion hydrolase was responsible. Strain G1 can efficiently degrade eight organophosphorus pesticides (OPs) and is a very excellent candidate for applications in OP pollution remediation

Rapid biodegradation of organophosphorus pesticides by Stenotrophomonas sp. G1

Energy Technology Data Exchange (ETDEWEB)

Deng, Shuyan; Chen, Yao [Key Laboratory of Agri-food Safety of Anhui Province, Lab of Quality & Safety and Risk Assessment for Agro-products on Storage and Preservation (Hefei), Ministry of Agriculture, School of Resource and Environment, Anhui Agricultural University, Hefei 230036 (China); Wang, Daosheng [School of Life Science, Anhui Agricultural University, Hefei 230036 (China); Shi, Taozhong; Wu, Xiangwei; Ma, Xin; Li, Xiangqiong [Key Laboratory of Agri-food Safety of Anhui Province, Lab of Quality & Safety and Risk Assessment for Agro-products on Storage and Preservation (Hefei), Ministry of Agriculture, School of Resource and Environment, Anhui Agricultural University, Hefei 230036 (China); Hua, Rimao, E-mail: rimaohua@ahau.edu.cn [Key Laboratory of Agri-food Safety of Anhui Province, Lab of Quality & Safety and Risk Assessment for Agro-products on Storage and Preservation (Hefei), Ministry of Agriculture, School of Resource and Environment, Anhui Agricultural University, Hefei 230036 (China); Tang, Xinyun [School of Life Science, Anhui Agricultural University, Hefei 230036 (China); Li, Qing X. [Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, 1955 East–West Road, Honolulu, HI 957822 (United States)

2015-10-30

Highlights: • Stenotrophomonas sp. G1 was isolated from chlorpyrifos contaminated sludge. • Strain G1 is closest to Stenotrophomonas acidaminiphila. • Strain G1 can efficiently degrade 8 organophosphorus pesticides (OPs). • Intracellular methyl parathion hydrolase is responsible for the OP degradation. • Three factors were orthogonally optimized for degradation of methyl parathion. - Abstract: Organophosphorus insecticides have been widely used, which are highly poisonous and cause serious concerns over food safety and environmental pollution. A bacterial strain being capable of degrading O,O-dialkyl phosphorothioate and O,O-dialkyl phosphate insecticides, designated as G1, was isolated from sludge collected at the drain outlet of a chlorpyrifos manufacture plant. Physiological and biochemical characteristics and 16S rDNA gene sequence analysis suggested that strain G1 belongs to the genus Stenotrophomonas. At an initial concentration of 50 mg/L, strain G1 degraded 100% of methyl parathion, methyl paraoxon, diazinon, and phoxim, 95% of parathion, 63% of chlorpyrifos, 38% of profenofos, and 34% of triazophos in 24 h. Orthogonal experiments showed that the optimum conditions were an inoculum volume of 20% (v/v), a substrate concentration of 50 mg/L, and an incubation temperature in 40 °C. p-Nitrophenol was detected as the metabolite of methyl parathion, for which intracellular methyl parathion hydrolase was responsible. Strain G1 can efficiently degrade eight organophosphorus pesticides (OPs) and is a very excellent candidate for applications in OP pollution remediation.

Kinetics of penetration of methyl parthion in desert locust, Schistocerca gregaria Forskal

International Nuclear Information System (INIS)

Sethi, G.R.; Garg, A.K.; Bhatia, P.; Mehrotra, K.N.; Bigley, W.S.

1985-01-01

Studies on the rate of disappearance of 14 C-methyl parathion, applied topically on the mesonotum of desert locust, Schistocerca gregaria Forskal revealed that the penetration of this insecticide did not follow the first order kinetics and showed a biphasic pattern. The faster phase of penetration lasted upto 120 min from the time of application (half-life 74+-18 min) whereas, the slower phase which was observed from 120 min to 24 hr had a half-life of 338+-130 min. (author)

Studies on dissipation and degradation of 14 C-DDT and 14 C-parathion in egyptian soil under field conditions

International Nuclear Information System (INIS)

Ezz El-Arab, A.; Mostafa, I.Y.

1991-01-01

The rates of dissipation and degradation of the insecticides DDT and parathion were studied under field conditionsm using 14 C-labelled chemicals. Over a period of 12 weeks, extractable, soil-bound and total 14 C-activity were recorded. In case of DDT, dissipation of 14 C-activity from soil showed a continuous and gradual increase reaching about 30% after 8 weeks and remained constant up to 12 weeks. The formation of DDE as a principal metabolite seems to be increasing with time ans accounted for approximately 25% of the extractable residues after 12 weeks. There was also a gradual significant increase in the formation of soil 14 C-bound residues which reached 12% of the total residues after the same period. On the other hand, parathion dissipation from the soil under the same conditions did not exceed 10% up to 12 weeks. The amount of 14 C-bound residues was found to contribute 33% of the applied dose. Analysis of the extractable fraction revealed that parathion was partly degraded by soil microorganisms into p-amino phenol, p-nitrophenol, paraoxon, amino parathion and aminoparaoxon in different percentages depending on the depth of soil. 2 fig.,1 tab

The influence of the organophosphorus insecticides acephate and parathion upon the heterotrophic bacteria of two freshwater ecosystems

International Nuclear Information System (INIS)

Albright, L.J.; Geen, G.H.; Gasith, A.; Mozel, Y.; Perry, A.S.

1983-01-01

The effect of acephate and parathion on the heterotrophic bacteria of freshwater ecosystems was studied in a dystrophic west coast Canadian lake and in an eutrophic Israeli fish pond. The limnocorrals were treated with 1-25 ppm of acephate and 30-40 ppb of parathion respectively. Bacterial populations, glucose heterotrophic activities and bacterial and algal productivities were studied using 3 H and 14 C radioisotopes. It is concluded that the two ecosystems are not extensively affected by the pesticide concentrations used

Distribution of 14C in soil and rice plants following application of 14C - parathion to soil

International Nuclear Information System (INIS)

Andrea, M.M. de; Ruegg, E.F.

1983-01-01

Amount of residues of 14 C-parathion in soil rice plants after application of the insecticide to soil were determined in four systems studied during five weeks: pots of soil with and without plants and open or enclosed by a transparent cover. Measurements of amounts volatilized and 14 CO 2 evolution from the pesticide were made in closed system without plants. The bound residues in soil and plants were also determined. Results indicated that parathion half life in a Gley Humic soil was about two weeks. Very little radiocarbon was taken up by rice plants; of this, more was found in shoots of plants enclosed, probably by collection of the volatilized material by plants. About 6% and 4% of the 14 C-parathion were found as volatilized material and 14 CO 2 , respectively after five weeks. Bound residues varied very little and reached a maximum of 22% in soil and in plants amounted to less than 2% at the final of the experiment. (Author) [pt

Antioxidant Evaluation of Methanolic Extract of Black Nightshades Ripe Fruits against Technical and Formulated Parathion-Induced Damage in Albino Rats

International Nuclear Information System (INIS)

Abdel-Rahiml, E.A.; Abdel-Rahim, G.A.; Atia, A.I.

2009-01-01

Parathion in technical or formulated form at a sub-lethal dose of 1/20 LD 50 was applied orally or dermally at 2-day interval for three months to determine its effect on RNA, DNA and protein content as well as RNA ase and DNA ase activity in different organs liver, brain and kidneys of adult male albino rats. Also, serum GOT, GPT and ALP activity as well as serum total soluble protein, albumin, globulin, bilirubin and uric acid content were determined in adult male albino rats (Rattus norvegicus). In addition, the present studies were undertaken to investigate different biological activities of the above parameters of black nightshades (Solanum nigrum L) methanolic extract. Two kinds of experimental works were taken off (antioxidants and protective). The results showed that technical and formulated parathion increased RNA and protein content but the content of DNA was insignificantly decreased in all rat organs tissue (liver, brain and kidneys) relative to control. The activity of RNA ase was also stimulated. In case of liver and kidney functions the present data observed that serum GOT, GPT and ALP activity was stimulated but total soluble protein, albumin and globulin content was decreased but the urea, uric acid and bilirubin content of serum was increased. Also, liver lipid peroxidation was elevated significantly either by technical or formulated parathion (ingested orally or induced dermally). It should be noted that formulated parathion ingested orally was the most effective, but the technical one had the lowest toxicity. The results of the present studies showed that crude methanolic extract of black nightshades ripe fruits has a strong antioxidant activity as showed by DPPH, nitric oxide scavenging, total reducing power, Fenton's reaction and total antioxidant capacity assay. Finally the the methanolic extract of the present medicinal plant observed a valuable influence as a protective agent in vivo in serum, liver, brain and kidneys damage of parathion

Comparative effects of parathion and chlorpyrifos on extracellular endocannabinoid levels in rat hippocampus: Influence on cholinergic toxicity

International Nuclear Information System (INIS)

Liu, Jing; Parsons, Loren; Pope, Carey

2013-01-01

Parathion (PS) and chlorpyrifos (CPF) are organophosphorus insecticides (OPs) that elicit acute toxicity by inhibiting acetylcholinesterase (AChE). Endocannabinoids (eCBs, N-arachidonoylethanolamine, AEA; 2-arachidonoylglycerol, 2AG) can modulate neurotransmission by inhibiting neurotransmitter release. We proposed that differential inhibition of eCB-degrading enzymes (fatty acid amide hydrolase, FAAH, and monoacylglycerol lipase, MAGL) by PS and CPF leads to differences in extracellular eCB levels and toxicity. Microdialysis cannulae were implanted into hippocampus of adult male rats followed by treatment with vehicle (peanut oil, 2 ml/kg, sc), PS (27 mg/kg) or CPF (280 mg/kg) 6–7 days later. Signs of toxicity, AChE, FAAH and MAGL inhibition, and extracellular levels of AEA and 2AG were measured 2 and 4 days later. Signs were noted in PS-treated rats but not in controls or CPF-treated rats. Cholinesterase inhibition was extensive in hippocampus with PS (89–90%) and CPF (78–83%) exposure. FAAH activity was also markedly reduced (88–91%) by both OPs at both time-points. MAGL was inhibited by both OPs but to a lesser degree (35–50%). Increases in extracellular AEA levels were noted after either PS (about 2-fold) or CPF (about 3-fold) while lesser treatment-related 2-AG changes were noted. The cannabinoid CB1 receptor antagonist/inverse agonist AM251 (3 mg/kg, ip) had no influence on functional signs after CPF but markedly decreased toxicity in PS-treated rats. The results suggest that extracellular eCBs levels can be markedly elevated by both PS and CPF. CB1-mediated signaling appears to play a role in the acute toxicity of PS but the role of eCBs in CPF toxicity remains unclear. - Highlights: • Chlorpyrifos and parathion both extensively inhibited hippocampal cholinesterase. • Functional signs were only noted with parathion. • Chlorpyrifos and parathion increased hippocampal extracellular anandamide levels. • 2-Arachidonoylglycerol levels were

Comparative effects of parathion and chlorpyrifos on extracellular endocannabinoid levels in rat hippocampus: Influence on cholinergic toxicity

Energy Technology Data Exchange (ETDEWEB)

Liu, Jing [Department of Physiological Sciences, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK (United States); Parsons, Loren [Committee on Neurobiology of Affective Disorders, The Scripps Research Institute, La Jolla, CA (United States); Pope, Carey, E-mail: carey.pope@okstate.edu [Department of Physiological Sciences, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK (United States)

2013-11-01

Parathion (PS) and chlorpyrifos (CPF) are organophosphorus insecticides (OPs) that elicit acute toxicity by inhibiting acetylcholinesterase (AChE). Endocannabinoids (eCBs, N-arachidonoylethanolamine, AEA; 2-arachidonoylglycerol, 2AG) can modulate neurotransmission by inhibiting neurotransmitter release. We proposed that differential inhibition of eCB-degrading enzymes (fatty acid amide hydrolase, FAAH, and monoacylglycerol lipase, MAGL) by PS and CPF leads to differences in extracellular eCB levels and toxicity. Microdialysis cannulae were implanted into hippocampus of adult male rats followed by treatment with vehicle (peanut oil, 2 ml/kg, sc), PS (27 mg/kg) or CPF (280 mg/kg) 6–7 days later. Signs of toxicity, AChE, FAAH and MAGL inhibition, and extracellular levels of AEA and 2AG were measured 2 and 4 days later. Signs were noted in PS-treated rats but not in controls or CPF-treated rats. Cholinesterase inhibition was extensive in hippocampus with PS (89–90%) and CPF (78–83%) exposure. FAAH activity was also markedly reduced (88–91%) by both OPs at both time-points. MAGL was inhibited by both OPs but to a lesser degree (35–50%). Increases in extracellular AEA levels were noted after either PS (about 2-fold) or CPF (about 3-fold) while lesser treatment-related 2-AG changes were noted. The cannabinoid CB1 receptor antagonist/inverse agonist AM251 (3 mg/kg, ip) had no influence on functional signs after CPF but markedly decreased toxicity in PS-treated rats. The results suggest that extracellular eCBs levels can be markedly elevated by both PS and CPF. CB1-mediated signaling appears to play a role in the acute toxicity of PS but the role of eCBs in CPF toxicity remains unclear. - Highlights: • Chlorpyrifos and parathion both extensively inhibited hippocampal cholinesterase. • Functional signs were only noted with parathion. • Chlorpyrifos and parathion increased hippocampal extracellular anandamide levels. • 2-Arachidonoylglycerol levels were

METIER (Modular Ecotoxicity Tests Incorporating Ecological Relevance) for difficult substances--III. Effects of medium renewal and use of a carrier on the bioavailability of parathion.

Science.gov (United States)

Guilhermino, L; Ribeiro, R; Gonçalves, F; Soares, A M

1996-01-01

In this work we compared the effects of medium renewal and use of a carrier (ethanol) in the lethal toxicity of parathion to Daphnia magna Straus. Actual concentrations measured in test solutions with and without ethanol were not significantly different, indicating that there is no need for a carrier solution to assist dissolution of parathion, up to a concentration of 5 mg litre(-1). LC50 values at 48 h from bioassays with and without medium renewal were identical, indicating that in our experimental conditions, degradation of parathion was not a significant consideration. Similar 48-h LC50 values were obtained in all tests, with or without ethanol present. Thus, potential interactions between carrier and toxicant had no effect on the lethal toxicity of parathion to D. magna.

Vervluchtiging van EPTC, tri-allaat en parathion na bespuiting van een kleigrond

NARCIS (Netherlands)

Bor, G.; Berg, van den F.; Smelt, J.H.; Peppel-Groen, van de A.E.; Leistra, M.

1995-01-01

Op tien tijdstippen na de bespuiting van een onbegroeide kleigrond met EPTC, tri-allaat en parathion werden de snelheden van vervluchtiging van deze middelen bepaald met de kapmethode en de theoretisch-profielmethode (TP-methode). De vervluchtiging was het hoogst op de dag van toepassing. In de

Degradation of /sup 14/C-parathion 'in vitro' by microorganisms isolated from a gley humic soil

Energy Technology Data Exchange (ETDEWEB)

Andrea, M.M. de; Ruegg, E.F. (Instituto Biologico, Sao Paulo (Brazil). Centro de Radioisotopos)

It was determined 'in vitro' the degradation of Parathion by a bacterium and a fungus isolated from a sample of Gley Humic soil previously treated with repeated applications of the insecticide. In a qualitative colorimetric assay hydrolysis of parathion to p-nitrophenol just the bacterium gave a positive answer. In quantitative assays of /sup 14/C-parathion degradation in culture media containing both microorganisms, organic solvents extractions resulted in organic and aqueous phases, which were analysed by liquid scintillation counting and thin-layer chromatography. In a mineral salts medium plus buffer, the bacterium and the fungus behaved differently from the control, because part of the /sup 14/C-insecticide was metabolized to, at least, one metabolite and besides, the microorganisms presented smaller percentages of total recovery. The largest percentage of the radio carbon recovery from the extracts of the medium containing the fungus plus extract of yeast, was obtained from the aqueous phase and the existence of other metabolite was demonstrated by chromatograms of the organic phase.

Determination of parathion in biological fluids by means of direct solid-phase microextraction.

Science.gov (United States)

Gallardo, E; Barroso, M; Margalho, C; Cruz, A; Vieira, D N; López-Rivadulla, M

2006-11-01

A new and simple procedure for the determination of parathion in human whole blood and urine using direct immersion (DI) solid-phase microextraction (SPME) and gas chromatography/mass spectrometry (GC/MS) is presented. This technique was developed using only 100 microL of sample, and ethion was used as internal standard (IS). A 65-microm Carbowax/divinylbenzene (CW/DVB) SPME fibre was selected for sampling, and the main parameters affecting the SPME process such as extraction temperature, adsorption and desorption time, salt addition, agitation and pH effect were optimized to enhance the sensitivity of the method. This optimization was also performed to allow the qualitative determination of parathion's main metabolite, paraoxon, in blood. The limits of detection and quantitation for parathion were 3 and 10 ng/mL for urine and 25 and 50 ng/mL for blood, respectively. For paraoxon, the limit of detection was 50 ng/mL in blood. The method showed linearity between the LOQ and 50 microg/mL for both matrices, with correlation coefficients ranging from 0.9954 to 0.9999. Precision and accuracy were in conformity with the criteria normally accepted in bioanalytical method validation. The mean absolute recoveries were 35.1% for urine and 6.7% for blood. Other parameters such as dilution of sample and stability were also validated. Its simplicity and the fact that only 100 microL of sample is required to accomplish the analysis make this method useful in forensic toxicology laboratories to determine this compound in intoxications, and it can be considered an alternative to other methods normally used for the determination of this compound in biological media.

Effective antibodies immobilization and functionalized nanoparticles in a quartz-crystal microbalance-based immunosensor for the detection of parathion.

Directory of Open Access Journals (Sweden)

Bartolomeo Della Ventura

Full Text Available Biosensor-based detection provides a rapid and low-cost alternative to conventional analytical methods for revealing the presence of the contaminants in water as well as solid matrices. Although important to be detected, small analytes (few hundreds of Daltons are an issue in biosensing since the signal they induce in the transducer, and specifically in a Quartz-Crystal Microbalance, is undetectable. A pesticide like parathion (M = 292 Da is a typical example of contaminant for which a signal amplification procedure is desirable.The ballasting of the analyte by gold nanoparticles has been already applied to heavy target as proteins or bacteria to improve the limit of detection. In this paper, we extend the application of such a method to small analytes by showing that once the working surface of a Quartz-Crystal Microbalance (QCM has been properly functionalized, a limit of detection lower than 1 ppb is reached for parathion. The effective surface functionalization is achieved by immobilizing antibodies upright oriented on the QCM gold surface by a simple photochemical technique (Photonic Immobilization Technique, PIT based on the UV irradiation of the antibodies, whereas a simple protocol provided by the manufacturer is applied to functionalize the gold nanoparticles. Thus, in a non-competitive approach, the small analyte is made detectable by weighing it down through a "sandwich protocol" with a second antibody tethered to heavy gold nanoparticles. The immunosensor has been proved to be effective against the parathion while showing no cross reaction when a mixture of compounds very similar to parathion is analyzed.The immunosensor described in this paper can be easily applied to any small molecule for which polyclonal antibodies are available since both the functionalization procedure of the QCM probe surface and gold nanoparticle can be applied to any IgG, thereby making our device of general application in terms of target analyte.

Metabolism of carbaryl, chloropyrifos, DDT, and parathion in the European corn borer: effects of microsporidiosis on toxicity and detoxication

International Nuclear Information System (INIS)

Tetreault, G.E.

1985-01-01

An investigation was conducted to examine the effects of microsporidiosis on an insect's response to insecticide intoxication. Healthy European corn borer, Ostrinia nubilalis, larvae and those heavily infected with the microsporidian pathogen, Nosema pyrausta, were bioassayed with ten insecticides. The compounds used were carbaryl, carbofuran, chlorophrifos, DDT, diazinon, fonofos, methomyl, parathion, permethrin, and terbufos. Third instar larvae were used for topical bioassays. The compounds carbaryl, carbofuran, chlorophrifos, methomyl and terbufos were found to be significantly more toxic to diseased insects than healthy insects at the 0.05 probability level. To examine the effect of Nosema pyrausta infection on the European corn borer's ability to detoxify insecticides, 14 C ring-labeled carbaryl, chlorophrifos, DDT, and parathion were topically applied to fourth instar larvae. Qualitative differences between healthy and diseased insects were found in the metabolic pathways of carbaryl, DDT, and parathion. The degradative fate of chlorophrifos was the same in both groups. Quantitatively, each insecticide penetrated diseased larvae faster. This resulted in larger amounts of the applied dose of parent compound and metabolites being found in the feces from diseased insects. Conversely, healthy insects had more of these materials present in the body and associated with the cuticle

Zero valent iron reduces toxicity and concentrations of organophosphate pesticides in contaminated groundwater

DEFF Research Database (Denmark)

Fjordbøge, Annika Sidelmann; Baun, Anders; Vastrup, Troels

2013-01-01

including synthesis intermediates and degradation products of organophosphates. The ZVI treatment showed that all the contaminants were degraded with the exception of two diesters (phosphorothioates). The most rapid reduction was found for methyl parathion, ethyl parathion and malathion, which had first...

Persistence of DDT and parathion residues on a plant surface as influenced by weather factors

NARCIS (Netherlands)

Fahmy, H.S.M.

1961-01-01

The decay of DDT and parathion deposits under the influence of temperature, rain and ultraviolet radiation was described. Temperature and solar radiation were the main factors limiting the residual effect. High mean temperatures were more important than high maxima.

DDT residues were more

Pesticide-Biota Interactions in Tropical Soils

International Nuclear Information System (INIS)

Sethunathan, N.; Wahid, P.A.; Rao, T.R.; Adhya, T.K.; Ramakrishna, C.; Ray, R.C.; Pal, S.S.; Chendrayan, K.; Sudhakar-Barik; Venkateswarlu, K.; Nayak, D.N.; Charyulu, P.B.B.N.; Rao, V.R.

1981-01-01

Studies using radiotracer techniques and gas-liquid chromatography showed that instantaneous degradation of parathion, methyl parathion and fenitrothion occurred upon their equilibration with soils pre-reduced by flooding with water; amino analogues of the respective insecticides were formed as major degradation products

Pesticide-Biota Interactions in Tropical Soils

Energy Technology Data Exchange (ETDEWEB)

Sethunathan, N.; Wahid, P. A.; Rao, T. R.; Adhya, T. K.; Ramakrishna, C.; Ray, R. C.; Pal, S. S.; Chendrayan, K.; Sudhakar-Barik,; Venkateswarlu, K.; Nayak, D. N.; Charyulu, P. B.B.N.; Rao, V. R. [Laboratory of Soil Microbiology, Division of Soil Science and Microbiology, Central Rice Research Institute, Cuttack-753006 (India)

1981-05-15

Studies using radiotracer techniques and gas-liquid chromatography showed that instantaneous degradation of parathion, methyl parathion and fenitrothion occurred upon their equilibration with soils pre-reduced by flooding with water; amino analogues of the respective insecticides were formed as major degradation products.

Burrowing and avoidance behaviour in marine organisms exposed to pesticide-contaminated sediment

DEFF Research Database (Denmark)

Møhlenberg, Flemming; Kiørboe, Thomas

1983-01-01

Behavioural effects of marine sediment contaminated with pesticides (6000 ppm parathion, 200 ppm methyl parathion, 200 ppm malathion) were studied in a number of marine organisms in laboratory tests and in situ. The burrowing behaviour in Macoma baltica, Cerastoderma edule, Abra alba, Nereis...

Antigenotoxic Effect of Curcumin and Carvacrol against Parathion Induced DNA Damage in Cultured Human Peripheral Blood Lymphocytes and Its Relation to GSTM1 and GSTT1 Polymorphism

Directory of Open Access Journals (Sweden)

Neeraj Kumar

2014-01-01

Full Text Available In recent years, the use of organophosphorus pesticides has been extensively increased and these compounds signify a major class of agricultural pesticides today. We studied antigenotoxic potential of curcumin and carvacrol against the parathion induced DNA damage in cultured peripheral blood lymphocytes using sister chromatid exchanges as a biomarker of genotoxicity. Heparinised fresh blood from healthy individuals was treated with 2.5 μg/mL concentration of parathion in presence of curcumin and carvacrol in order to observe the antigenotoxic potential of both curcumin and carvacrol. Significant reduction (P0.05 of GSTT1 and GSTM1 polymorphism on genotoxicity of parathion and antigenotoxic potential of curcumin and carvacrol.

Degradation of the insecticide ethyl parathion in different environmental matrices by gamma radiation from Cobalt-60; Degradacao do inseticida paration etilico em diversas matrizes ambientais por meio de radiacao ionizante gama do cobalto-60

Energy Technology Data Exchange (ETDEWEB)

Luchini, Luiz Carlos

1995-07-01

This work studies the use of gamma radiation from cobalt-60 to induce parathion degradation in different matrices, as well as, quantified GC-NPD and identified by GC-MS, the radiolysis resulting products. Results show that the insecticide was completely degraded in aqueous solution after treatment with 1.0 kGy dosis in a dosis rate of 3.12 kGy h{sup -1}. In methanol, parathion was completely degraded only with 30 kGy at 3.12 kGy h{sup -1}. The metabolites detected after radiolysis were the same formed by biological degradation, i.e, p-nitrophenol, p-aminophenol, paraoxon and aminoparathion. The gamma radiation also degraded paraoxon which is the most toxic metabolite of parathion. It was verified that, not only the total radiation, but also the dosis rate supplied to the aqueous solution had a significant effect on the insecticide degradation, and the formation of metabolites occurred in a selective way respecting the dosis and dosis rate. Otherwise, the gamma radiation did almost not degraded the parathion adsorbed in solid matrices as rice, moist and dry soil, even using dosis of 5,30 and 50 kGy, respectively. The parathion yield and the dosis of gamma radiation needed for 50% reduction of the insecticide initial concentration in aqueous solution were also calculated and presented. Thus, it was verified that irradiation of parathion besides to be an important instrument for environmental decontamination of this pesticide in aqueous matrix, it allows the production of parathion metabolites for ecotoxicological studies. (author)

Effects of fertilizers, fungicides and herbicides on the fate of 14C-parathion and 14C-fonofos in soils and crops

International Nuclear Information System (INIS)

Lichtenstein, E.P.; Ferris, I.; Liang, T.T.; Koeppe, M.

1983-01-01

The fate of 14 C-parathion and 14 C-fonofos in soil is significantly affected by the presence of organic and inorganic fertilizers, fungicides and herbicides, possibly via the effect of soil microflora. Soil microorganisms are responsible for the oxidative as well as the reductive degradation of the insecticide. Using 14 carbon, the authors studied the effects of selected fungicides (benlate, captafol and manzate) herbicides (2,4-D parathion) and fertilizers ((NH 4 ) 6 SO 4 , KNO 3 , urea) on pesticides in Cromberry soils. Results of the study stress the importance of investigating the environmental fate of a particular pesticide in relation to the presence of the agricultural chemicals

Concentration of Organochlorine and Organophosphorus Pesticides in Different Molluscs from Tighra Reservoir, Gwalior, India.

Science.gov (United States)

Mamta; Rao, R J; Wani, Khursheed Ahmad

2015-09-01

Concentration of organochlorine and organophosphorus pesticides and their metabolites were determined in whole body homogenate of L. acuminata, I. exustus, V. dissimilis, V. bengalensis, from Tighra Reservoir during summer and post monsoon season using GC-MS technique. The different types of pesticides viz., HCB, heptachlor, aldrin, endosulfan, dieldrin, p,p-DDT, choloropyrifos, methyl parathion, dicholorovos, ethion, malathion, parathion were found in resident molluscs studied. Concentration of these pesticides varied independently during the summer and the post monsoon season at monitored sites. The study concluded that presence of pesticides in Tighra Reservoir is a major concern on public and ecosystem health and use of biopesticides in the adjacent area of Reservoir is highly recommended.

Volatilization of tri-allate, ethoprophos and parathion measured with four methods after spraying on a sandy soil

NARCIS (Netherlands)

Bor, G.; Berg, van den F.; Smelt, J.H.; Smidt, R.A.; Peppel-Groen, van de A.E.; Leistra, M.

1995-01-01

At about eleven times after application of tri-allate, ethoprophos and parathion to a sandy soil, their rates of volatilization were determined by the aerodynamic method (AD), the Bowen-ratio method (BR), the theoretical-profile method (TP) and the Box method. The volatilization was highest for

Determination of parathion in biological fluids by means of direct Solid Phase Microextraction.

OpenAIRE

Gallardo, Eugenia; Barroso, Mário; Margalho, C.; Cruz, Angelines; Vieira, Duarte Nuno; López-Rivadulla, Manuel

2010-01-01

A new and simple procedure for the determination of parathion in human whole blood and urine using direct immersion (DI) solid-phase microextraction (SPME) and gas chromatography/mass spectrometry (GC/MS) is presented. This technique was developed using only 100 ìL of sample, and ethion was used as internal standard (IS). A 65-ìm Carbowax/divinylbenzene (CW/DVB) SPME fibre was selected for sampling, and the main parameters affecting the SPME process such as extraction ...

Maternal Methyl Supplemented Diets and Effects on Offspring Health

Directory of Open Access Journals (Sweden)

Rachel J. O'Neill

2014-08-01

Full Text Available Women seeking to become pregnant and pregnant women are currently advised to consume high amounts of folic acid and other methyl donors to prevent neural tube defects in their offspring. These diets can alter methylation patterns of several biomolecules, including nucleic acids and histone proteins. Limited animal model data suggests that developmental exposure to these maternal methyl supplemented (MS diets leads to beneficial epimutations. However, other rodent and humans studies have yielded opposing findings with such diets leading to promiscuous epimutations that are likely associated with negative health outcomes. Conflict exists to whether these maternal diets are preventative or exacerbate the risk for ASD in children. This review will discuss the findings to date on the potential beneficial and aversive effects of maternal MS diets. We will also consider how other factors might influence the effects of MS diets. Current data suggest that there is cause for concern as maternal MS diets may lead to epimutations that underpin various diseases, including neurobehavioral disorders. Further studies are needed to explore the comprehensive effects maternal MS diets have on the offspring epigenome and subsequent overall health.

Pneumonitis and lethal pulmonary fibrosis (Hamman-Rich syndrome) due to Parathione (E605) poisoning

International Nuclear Information System (INIS)

Lotz, W.; Fasske, E.; Forschungsinstitut Borstel

1986-01-01

A patient with chronic Parathione (E 605) poisoning was observed over a period of 55 days. During that time he developed progressive changes, which were identical to those of progressive idiopathic pulmonary fibrosis. The rapid development of an alveolitis, followed by a lethal pulmonary fibrosis, differed in no way, macroscopically nor microscopically, from the lung changes in paraquat poisoning (paraquat lung). The radiologic course has been correlated with the clinical and post mortem findings. (orig.) [de

Long-range transport and multimedia partitioning of semivolatile organic compounds: a case study on two modern agrochemicals

Energy Technology Data Exchange (ETDEWEB)

Lammel, G.; Feichter, J. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany); Leip, A. [Hamburg Univ. (Germany). Meteorologisches Inst.

2001-08-01

The global environmental fate of two modern pesticides was studied using a multimedia model based on a three-dimensional atmosphere general circulation model. The emissions are predicted dynamically based on agricultural application inventories. The insecticide methyl parathion, when assuming properties at the high mobility end of the respective data uncertainties, was found to be distributed on continental and even global scales. This finding implies that based on present knowledge one cannot exclude that methyl parathion reaches regions as far from the sources as e.g. the Arctic. Two scenarios of the environmental cycling of the herbicide atrazine were studied which reflect a lower and an upper estimate of the substance' mobility. Atrazine largely remains in the source (application) regions and the neighbouring seas. But also atrazine seems to have an albeit limited potential for long-range transport. The findings on substance mobilities are quantified by indicators which address spatial range in the zonal direction in individual media. The seasonal variability of the total environmental burden of both pesticides is governed by the degradation in soil and vegetation which together host 73% of methyl parathion and 90-99% of atrazine. Also, the cycling between compartments was studied. Methyl parathion undergoes more deposition and re-emission cycles than atrazine, a characteristics of the environmental fate of semivolatile substances. Persistence is addressed by determination of global total environmental decay times during periods without introduction of new substance into the environment. These are in the range 4-7 months. It is found that the seasonal variability of persistence is pronounced. (orig.)

A sensitive chemiluminescence enzyme immunoassay based on molecularly imprinted polymers solid-phase extraction of parathion.

Science.gov (United States)

Chen, Ge; Jin, Maojun; Du, Pengfei; Zhang, Chan; Cui, Xueyan; Zhang, Yudan; She, Yongxin; Shao, Hua; Jin, Fen; Wang, Shanshan; Zheng, Lufei; Wang, Jing

2017-08-01

The chemiluminescence enzyme immunoassay (CLEIA) method responds differently to various sample matrices because of the matrix effect. In this work, the CLEIA method was coupled with molecularly imprinted polymers (MIPs) synthesized by precipitation polymerization to study the matrix effect. The sample recoveries ranged from 72.62% to 121.89%, with a relative standard deviation (RSD) of 3.74-18.14%.The ratio of the sample matrix-matched standard curve slope rate to the solvent standard curve slope was 1.21, 1.12, 1.17, and 0.85 for apple, rice, orange and cabbage in samples pretreated with the mixture of PSA and C 18 . However, the ratio of sample (apple, rice, orange, and cabbage) matrix-matched standard-MIPs curve slope rate to the solvent standard curve was 1.05, 0.92, 1.09, and 1.05 in samples pretreated with MIPs, respectively. The results demonstrated that the matrices of the samples greatly interfered with the detection of parathion residues by CLEIA. The MIPs bound specifically to the parathion in the samples and eliminated the matrix interference effect. Therefore, the CLEIA method have successfully applied MIPs in sample pretreatment to eliminate matrix interference effects and provided a new sensitive assay for agro-products. Copyright © 2017 Elsevier Inc. All rights reserved.

Metabolism of (phenyl-U-14C)-parathion and its metabolite p-nitrophenol in the rat

International Nuclear Information System (INIS)

Schmidt-Sonnenschein, B.

1977-08-01

(Phenyl-U- 14 C)-parathion was orally given to rats in doses of 2.7 or 3.5 mg per kg body weight. Within 24 h, more than 95 % of the dose applied had left the body renally and about 7 % faecally. Resorption of the agent started early. Most of it was resorbed between 2 and 4 h after application. 2 h after application, there were still 85 % 14 C residues in the gastrointestinal tract, but only about 10 % was left 8 h later. Radioactivity contents in the blood and the internal organs, on the other hand, never exceeded 1 % of the applied dose. With radioactivity displacement into deeper intestinal sections, the fraction of water-soluble metabolites increased from about 1-3 % in the stomach to about 60 % in the large intestine. Using thin film chromatography and autoradiography, the following compounds were detected in the urine and tissues: The initial agent parathion, its oxidation product paraoxon and the hydrolysis product p-nitrophenol as organic-soluble compounds, and deethyl-paraoxon, p-nitrophenyl glucuronide and p-nitrophenyl sulphate as water-soluble metabolites. In urine, 65-80% of the radioactivity content was represented by a substance which may be the sulphate ester of p-nitrophenol. A total of 58 % of the applied dose was excreted in the form of this metabolite within 8 h. (orig./MG) [de

Photocatalytic degradation of an organophosphorus pesticide from agricultural waste by immobilized TiO2 under solar radiation

Directory of Open Access Journals (Sweden)

Marcia Regina Assalin

2016-11-01

Full Text Available This paper describes solar heterogeneous photocatalysis using immobilized TiO2 applied in the treatment of agricultural waste resulting from the application of commercial formulations of methyl parathion. The disappearance of the insecticide, as well as the formation of its metabolite, was monitored by high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS, while mineralization efficiency was monitored by measurements of total organic carbon (TOC. Toxicity studies were performed using the microcrustacean Artemia salina. The TOC removal efficiency by photocatalytic process was 48.5%. After 45 minutes of treatment, the removal efficiency of methyl parathion was 90%, being completely mineralized at the end of treatment. The formation and removal of the metabolite methyl paraoxon was observed during the photocatalytic process. The photocatalytic treatment resulted in increased microcrustacean mobility, indicating a reduction of acute toxicity.

Aberrant DNA Methylation: Implications in Racial Health Disparity.

Directory of Open Access Journals (Sweden)

Xuefeng Wang

Full Text Available Incidence and mortality rates of colorectal carcinoma (CRC are higher in African Americans (AAs than in Caucasian Americans (CAs. Deficient micronutrient intake due to dietary restrictions in racial/ethnic populations can alter genetic and molecular profiles leading to dysregulated methylation patterns and the inheritance of somatic to germline mutations.Total DNA and RNA samples of paired tumor and adjacent normal colon tissues were prepared from AA and CA CRC specimens. Reduced Representation Bisulfite Sequencing (RRBS and RNA sequencing were employed to evaluate total genome methylation of 5'-regulatory regions and dysregulation of gene expression, respectively. Robust analysis was conducted using a trimming-and-retrieving scheme for RRBS library mapping in conjunction with the BStool toolkit.DNA from the tumor of AA CRC patients, compared to adjacent normal tissues, contained 1,588 hypermethylated and 100 hypomethylated differentially methylated regions (DMRs. Whereas, 109 hypermethylated and 4 hypomethylated DMRs were observed in DNA from the tumor of CA CRC patients; representing a 14.6-fold and 25-fold change, respectively. Specifically; CHL1, 4 anti-inflammatory genes (i.e., NELL1, GDF1, ARHGEF4, and ITGA4, and 7 miRNAs (of which miR-9-3p and miR-124-3p have been implicated in CRC were hypermethylated in DNA samples from AA patients with CRC. From the same sample set, RNAseq analysis revealed 108 downregulated genes (including 14 ribosomal proteins and 34 upregulated genes (including POLR2B and CYP1B1 [targets of miR-124-3p] in AA patients with CRC versus CA patients.DNA methylation profile and/or products of its downstream targets could serve as biomarker(s addressing racial health disparity.

Differential DNA Methylation in Relation to Age and Health Risks of Obesity

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María Luisa Mansego

2015-07-01

Full Text Available The aim of this study was to evaluate whether genome-wide levels of DNA methylation are associated with age and the health risks of obesity (HRO; defined according to BMI categories as “Low HRO” (overweight and class 1 obesity versus “High HRO” (class 2 and class 3 obesity. Anthropometric measurements were assessed in a subsample of 48 volunteers from the Metabolic Syndrome Reduction in Navarra (RESMENA study and 24 women from another independent study, Effects of Lipoic Acid and Eicosapentaenoic Acid in Human Obesity (OBEPALIP study. In the pooled population; the methylation levels of 55 CpG sites were significantly associated with age after Benjamini-Hochberg correction. In addition, DNA methylation of three CpG sites located in ELOVL2; HOXC4 and PI4KB were further negatively associated with their mRNA levels. Although no differentially methylated CpG sites were identified in relation to HRO after multiple testing correction; several nominally significant CpG sites were identified in genes related to insulin signaling; energy and lipid metabolism. Moreover, statistically significant associations between BMI or mRNA levels and two HRO-related CpG sites located in GPR133 and ITGB5 are reported. As a conclusion, these findings from two Spanish cohorts add knowledge about the important role of DNA methylation in the age-related regulation of gene expression. In addition; a relevant influence of age on DNA methylation in white blood cells was found, as well as, on a trend level, novel associations between DNA methylation and obesity.

Rapid treatment of water contaminated with Atrazine and Parathion with sero-valent iron

International Nuclear Information System (INIS)

Rima, Jamil; Amine, Charbel; Ghauch, Antoine; Martin-Bouyer, Michel

1999-01-01

Full text.Experiments were conducted in order to assess the utility of fine-grained iron metal in the remediation of water contaminated with pesticides. The two pesticides that were chosen for this study were Atrazine and Parathion. batch procedures under water treatment conditions (ambient temperature and circumneutral pH) indicated that these pesticides degrade rapidly in the presence of iron powder (40-60 mes, 40 g/L). The decline in the concentration of pesticide was monitored by HPLC analysis supplemented with programmable multiwavelength UV/VIS detector. Experiments were run in buffered solutions. Tests were also performed on an industrial effluent solution containing a variety of pesticides. Our HPLC results indicating the disappearance of all the parent pollutants

Prostate cancer and toxicity from critical use exemptions of methyl bromide: Environmental protection helps protect against human health risks

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Budnik Lygia T

2012-01-01

Full Text Available Abstract Background Although ozone-depleting methyl bromide was destined for phase-out by 2005, it is still widely applied as a consequence of various critical-use-exemptions and mandatory international regulations aiming to restrict the spread of pests and alien species (e.g. in globalized transport and storage. The withdrawal of methyl bromide because of its environmental risk could fortuitously help in the containment of its human toxicity. Methods We performed a systematic review of the literature, including in vitro toxicological and epidemiological studies of occupational and community exposure to the halogenated hydrocarbon pesticide methyl bromide. We focused on toxic (especially chronic or carcinogenic effects from the use of methyl bromide, on biomonitoring data and reference values. Eligible epidemiological studies were subjected to meta-analysis. Results Out of the 542 peer reviewed publications between 1990-2011, we found only 91 referring to toxicity of methyl bromide and 29 using the term "carcinogenic", "neoplastic" or "mutagenic". Several studies provide new additional data pertaining to the mechanistic aspects of methyl bromide toxicity. Few studies have performed a detailed exposure assessment including biomonitoring. Three evaluated epidemiological studies assessed a possible association between cancer and methyl bromide. Overall, exposure to methyl bromide is associated with an increased risk of prostate cancer OR, 1.21; 95% CI (0,98-1.49, P = 0.076. Two epidemiological studies have analyzed environmental, non-occupational exposure to methyl bromide providing evidence for its health risk to the general public. None of the epidemiological studies addressed its use as a fumigant in freight containers, although recent field and case reports do refer to its toxic effects associated with its use in shipping and storage. Conclusions Both the epidemiological evidence and toxicological data suggest a possible link between methyl

Toxic Chemicals in the Soil Environment. Volume 2. Interactions of Some Toxic Chemicals/Chemical Warfare Agents and Soils

Science.gov (United States)

1985-06-01

K., S. Barik , and N. Sethunathan. 1981. Stability of commercial formulations of fenitrothion, methyl parathion, and parathion in anaero- bic soils. J ...34 D(Cl - C2 )L where; J - rate of flow or flWx, or the 4mount of solute (chemical) diffuisiguuit ti= across a unit crossý-ectional area, D difffuoion...surfaces (coatentrations C, aud C2) varies vith the concentration gradient, tlus’: 3 - -D(dC/dx) Where: J * the flux in grams or moles in cm%1s- acroeas a

Formation and bio release of bound residues of [14 C]-lindane and [14 C]-parathion in two Brazilian soils

International Nuclear Information System (INIS)

Andrea, M.M. de.

1992-01-01

This work studied the extractable and bound residues formation of 14 C-lindane and 14 C-parathion immediately after application and after 3 months of interaction of the pesticides with the soils. Metabolism, bio release, and the possible bioavailability of bound residues were studied by employing bio meter flasks which allowed a relative comparison of the behaviour of the two different 14 C-pesticides, by a balance of the applied or present radiocarbon in the soils after the bio tests. (author)

Immobilization of acetylcholinesterase via biocompatible interface of silk fibroin for detection of organophosphate and carbamate pesticides

Energy Technology Data Exchange (ETDEWEB)

Xue Rui [College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China); Kang Tianfang, E-mail: kangtf@yahoo.cn [College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China); Lu Liping; Cheng Shuiyuan [College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China)

2012-06-01

An amperometric biosensor for the detection of organophosphate and carbamate pesticides was developed based on the immobilization of acetylcholinesterase (AChE) on regenerated silk fibroin (SF) matrix by non-covalent adsorption. SF and AChE were coated sequentially on the surface of the glassy carbon electrode (GCE) which was modified with multiwall carbon nanotube (MWNTs). The obtained biosensor was denoted as AChE-SF/MWNTs/GCE. The atomic force microscopy images showed that the SF matrix provided a more homogeneous interface for the AChE immobilization. The aggregation of immobilizing AChE was therefore avoided. The cyclic voltammogram of thiocholine at this biosensor exhibited a well defined oxidation peak at 0.667 V (vs. SCE). The inhibition rate of methyl parathion to the immobilized AChE was proportional to the logarithm of the concentration of methyl parathion over the range of the concentration of methyl parathion from 3.5 Multiplication-Sign 10{sup -6} to 2.0 Multiplication-Sign 10{sup -3} M with a detection limit of 5.0 Multiplication-Sign 10{sup -7} M. Similarly, the linearly response range of carbaryl was from 1.0 Multiplication-Sign 10{sup -7} to 3.0 Multiplication-Sign 10{sup -5} M with a detection limit of 6.0 Multiplication-Sign 10{sup -8} M. The experimental results indicate that AChE not only can be immobilized steadily on the SF matrix, but also the bioactivity of immobilizing AChE can be preserved effectively.

Pesticide Degrading Bacteria in Aquatic Environment: Bioprospecting and Evaluation of Biotechnological Potential

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Daniel Rodrigues dos Santos

2016-07-01

Full Text Available Pesticides play an important role in the increase of productivity in agro-industry and the extensive use of these substances cause environmental, economic and social damage in time. Microbial activity is an essential part in the dynamics and the destination of pesticides in the environment. This research focuses in prospecting and characterizing bacterial strains which are potentially able to degrade/tolerate Atrazine, Chlorpyrifos, Methyl parathion and Picloram. Bacteria were isolated from water samples collected according to the degree of salinity along the Pacoti River's estuary (Ceara, located in the semi-arid region of northeastern Brazil. A total of 49 bacterial strains were isolated, all of which tolerated/ downgraded concentrations up to 200mg/L of picloram, atrazine and methyl parathion. Tested in pesticide mixtures, the percentage and tolerance level showed that 73% grew in concentrations up to 200mg/L, 17,4% tolerated/ downgraded up to 150ml/L and the remainder only grew in concentrations under 100ml/L. The strains which had the best performance against pesticides, by points, were P1 (13Db e 14D; P2 (10E; P3 (2M, 9M, 10M, 12Mb, 14M, 17M 18Mp 19M e 20M. A high percentage of isolates (67% expressed luminescence when exposed to the pesticides atrazine and methyl parathion in concentrations between 150 and 200ml/L. DOI: http://dx.doi.org/10.17807/orbital.v8i4.748

Concentration-mortality responses of Myzus persicae and natural enemies to selected insecticides.

Science.gov (United States)

Bacci, Leandro; Rosado, Jander F; Picanço, Marcelo C; Pereira, Eliseu J G; Silva, Gerson A; Martins, Júlio C

2012-01-01

The toxicity of six insecticides was determined for the peach-potato aphid, Myzus persicae (Hemiptera: Aphididae), and some of its natural enemies - the predatory beetles Cycloneda sanguinea (Coccinellidae) and Acanthinus sp. (Anthicidae), and the wasp parasitoid Diaeretiella rapae (Aphidiidae). Natural enemies from these groups are important natural biological control agents in a number of agroecosystems, and insecticides potentially safe to these non-target organisms should be identified using standardized tests. Thus, concentration-mortality bioassays were carried out with both the aphid and its natural enemies to assess the toxicity and selectivity of acephate, deltamethrin, dimethoate, methamidophos, methyl parathion, and pirimicarb. The latter insecticide was highly selective to all natural enemies tested, and its LC(90) for M. persicae was 14-fold lower than the field rate recommended for control of the aphid in brassica crops. Methyl parathion also showed selectivity to C. sanguinea and Acanthinus sp., but not to D. rapae. Acephate was the least potent insecticide against M. persicae and was equally or more toxic to the natural enemies relative to the aphid. Pirimicarb and methyl parathion were efficient against M. persicae and selective in favor of two of the natural enemies tested. Acanthinus sp. and C. sanguinea were more tolerant to the insecticides than was the parasitoid D. rapae. This study shows that there are selective insecticides that may be compatible with conservation of natural enemies in brassica crops, which is important practical information to improve integrated pest management systems in these crops.

Electrochemical monitoring of methyl parathion degradation based ...

African Journals Online (AJOL)

... been investigated by using carbon fiber microelectrodes (CFME) as working electrode and acetate buffer pH 5.2 as supporting electrolyte. pnitrophenol (PNP) and p-aminophenol (PAP) recognized as by-products of MP degradation process have been detected and identified in real time using square wave voltammetry.

Toxicity and bioaccumulation of xenobiotic organic compounds in the presence of aqueous suspensions of aggregates of nano-C60

DEFF Research Database (Denmark)

Baun, Anders; Sørensen, Sara Nørgaard; Rasmussen, R.F.

2008-01-01

The potential of C60-nanoparticles (Buckminster fullerenes) as contaminant carriers in aqueous systems was studied in a series of toxicity tests with algae (Pseudokirchneriella subcapitata) and crustaceans (Daphnia magna). Four common environmental contaminants (atrazine, methyl parathion, pentac...

of Several Organophosphorus Insecticide Metabolites

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Russell L. Carr

2015-01-01

Full Text Available Paraoxonase (PON1 is a calcium dependent enzyme that is capable of hydrolyzing organophosphate anticholinesterases. PON1 activity is present in most mammals and previous research established that PON1 activity differs depending on the species. These studies mainly used the organophosphate substrate paraoxon, the active metabolite of the insecticide parathion. Using serum PON1 from different mammalian species, we compared the hydrolysis of paraoxon with the hydrolysis of the active metabolites (oxons of two additional organophosphorus insecticides, methyl parathion and chlorpyrifos. Paraoxon hydrolysis was greater than that of methyl paraoxon, but the level of activity between species displayed a similar pattern. Regardless of the species tested, the hydrolysis of chlorpyrifos-oxon was significantly greater than that of paraoxon or methyl paraoxon. These data indicate that chlorpyrifos-oxon is a better substrate for PON1 regardless of the species. The pattern of species differences in PON1 activity varied with the change in substrate to chlorpyrifos-oxon from paraoxon or methyl paraoxon. For example, the sex difference observed here and reported elsewhere in the literature for rat PON1 hydrolysis of paraoxon was not present when chlorpyrifos-oxon was the substrate.

Polineuropatia por Parathion: estudo clinico, eletrofisiológico e histológico de um caso

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José L. Alonso

1983-09-01

Full Text Available Estudamos um paciente com quadro clínico rebelde, produzido por intoxicação pelo Parathion. Foi observado um fenômeno miotônico transitório, não descrito na literatura revisada. A constatação de cifras de AchE eritrocitária baixas e de colinesterase plasmática normais, indicou que era portador de déficit congênito de AchE, esclarecendo-se a evolução crônica do seu quadro. O fenômeno miotônico associado ao quadro clínico, eletrofisiológico, histológico e bioquímico fazem deste paciente um modelo clínico, de etiologia conhecida, da discutida síndrome de Isaacs.

Experimental vapor pressures (from 1 Pa to 100 kPa) of six saturated Fatty Acid Methyl Esters (FAMEs): Methyl hexanoate, methyl octanoate, methyl decanoate, methyl dodecanoate, methyl tetradecanoate and methyl hexadecanoate

International Nuclear Information System (INIS)

Sahraoui, Lakhdar; Khimeche, Kamel; Dahmani, Abdallah; Mokbel, Ilham; Jose, Jacques

2016-01-01

Highlight: • Vapor-liquid equilibria, Enthalpy of Vaporization, saturated Fatty Acid Methyl Ester. - Abstract: Vapor pressures of six saturated Fatty Acid Methyl Esters (FAMEs), methyl hexanoate (or methyl caproate), methyl octanoate (or methyl caprylate), Methyl decanoate (or methyl caprate), methyl dodecanoate (or methyl laurate), methyl tetradecanoate (or methyl myristate), and methyl hexadecanoate (or methyl palmitate) were measured from 1 Pa to 100 kPa and at temperature range between 262 and 453 K using a static apparatus. The experimental data (P-T) were compared with the available literature data.

Accelerated dephosphorylation of adenosine phosphates and related compounds in the presence of nanocrystalline cerium oxide

Czech Academy of Sciences Publication Activity Database

Janoš, P.; Lovászová, I.; Pfeifer, J.; Ederer, J.; Došek, M.; Loučka, T.; Henych, Jiří; Kolská, Z.; Milde, D.; Opletal, T.

2016-01-01

Roč. 3, č. 4 (2016), s. 847-856 ISSN 2051-8153 R&D Projects: GA MŠk(CZ) LM2015073 Institutional support: RVO:61388980 Keywords : reactive sorbent * parathion methyl * nanoparticles * hydrolysis Subject RIV: CA - Inorganic Chemistry Impact factor: 6.047, year: 2016

Acetylcholinesterase biosensor based on SnO2 nanoparticles-carboxylic graphene-nafion modified electrode for detection of pesticides.

Science.gov (United States)

Zhou, Qing; Yang, Long; Wang, Guangcan; Yang, Yun

2013-11-15

A sensitive amperometric acetylcholinesterase (AChE) biosensor, based on SnO2 nanoparticles (SnO2 NPs), carboxylic graphene (CGR) and nafion (NF) modified glassy carbon electrode (GCE) for the detection of methyl parathion and carbofuran has been developed. The nanocomposites of SnO2 NPs and CGR was synthesized and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR), respectively. Chitosan (CS) was used to immobilize AChE on SnO2 NPs-CGR-NF/GCE and to improve electronic transmission between AChE and SnO2 NPs-CGR-NF/GCE. NF was used as the protective membrane for the AChE biosensor. The SnO2 NPs-CGR-NF nanocomposites with excellent conductivity, catalysis and biocompatibility offered an extremely hydrophilic surface for AChE adhesion. The AChE biosensor showed favorable affinity to acetylthiocholine chloride (ATCl) and could catalyze the hydrolysis of ATCl with an apparent Michaelis-Menten constant value of 131 μM. The biosensor detected methyl parathion in the linear range from 10(-13) to 10(-10)M and from 10(-10) to 10(-8)M. The biosensor detected carbofuran in the linear range from 10(-12) to 10(-10)M and from 10(-10) to 10(-8)M. The detection limits of methyl parathion and carbofuran were 5 × 10(-14)M and 5 × 10(-13)M, respectively. The biosensor exhibited low applied potential, high sensitivity and acceptable stability, thus providing a promising tool for analysis of pesticides. Copyright © 2013 Elsevier B.V. All rights reserved.

A derivative photoelectrochemical sensing platform for 4-nitrophenolate contained organophosphates pesticide based on carboxylated perylene sensitized nano-TiO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Li, Hongbo [College of Chemistry and Engineering, Yangzhou University, 88 South University Avenue, Yangzhou 225002 (China); College of Chemistry and Biology Engineering, Yancheng Institute of Technology, 9 Yingbin Avenue, Yancheng 224051 (China); Li, Jing [College of Chemistry and Biology Engineering, Yancheng Institute of Technology, 9 Yingbin Avenue, Yancheng 224051 (China); Xu, Qin; Yang, Zhanjun [College of Chemistry and Engineering, Yangzhou University, 88 South University Avenue, Yangzhou 225002 (China); Hu, Xiaoya, E-mail: xyhu@yzu.edu.cn [College of Chemistry and Engineering, Yangzhou University, 88 South University Avenue, Yangzhou 225002 (China)

2013-03-05

Highlights: ► A novel enzymeless photoelectrochemical sensor for 4-nitrophenolate contained OPs. ► Sensors have performances of rapid response, good sensitivity and selectivity. ► PTCA as sensitizer can form ultrastable thin film and is economic as well. ► The strategy extends the application of PTCA for photoelectrochemical sensor. - Abstract: A novel visible light sensitized photoelectrochemical sensing platform was constructed based on the perylene-3,4,9,10-tetracarboxylic acid/titanium dioxide (PTCA/TiO{sub 2}) heterojunction as the photoelectric beacon. PTCA was synthesized via facile steps of hydrolysis and neutralization reaction, and then the PTCA/TiO{sub 2} heterojunction was easily prepared by coating PTCA on nano-TiO{sub 2} surface. The resulting photoelectric beacon was characterized by transmission electron microscope, scanning electron microscopy, X-ray diffractometry, FTIR spectroscopy, and ultraviolet and visible spectrophotometer. Using parathion-methyl as a model, after a simple hydrolyzation process, p-nitrophenol as the hydrolysate of parathion-methyl could be obtained, the fabricated derivative photoelectrochemical sensor showed good performances with a rapid response, instrument simple and portable, low detection limit (0.08 nmol L{sup −1}) at a signal-to-noise ratio of 3, and good selectivity against other pesticides and possible interferences. It had been successfully applied to the detection of parathion-methyl in green vegetables and the results agreed well with that by GC–MS. This strategy not only extends the application of PTCA, but also presents a simple, economic and novel methodology for photoelectrochemical sensing.

Determinação eletroquímica do pesticida parationa metílica em águas de reservatório por voltametria de redissolução catódica

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Silvanito A. Barbosa

2011-12-01

Full Text Available Methyl parathion is an organophosphorus compound widely used in Brazilian agriculture as antifouling agent. Given its importance, this paper presents the development and application of an electrochemical method for determination of the compound in natural waters. Results obtained during an initial optimization stage demonstrated the suitability of the technique for trace analysis, with limits of detection and quantification of 1.3 µg L-1 and 4.3 µg L-1, respectively. Samples were collected from the Jabiberi River (Tobias Barreto, State of Sergipe and were shown to contain methyl parathion concentrations of 96.9 µg L-1 (location 1 and 34.7 µg L-1 (location 2. These measurements are indicative of levels of contamination above those permitted by Brazilian legislation (CONAMA. Hence, in addition to assisting in the validation of the electroanalytical method as a tool for pesticide analysis, the results highlight the need for regulation and control of pesticide levels in natural waters.

Levels of organophosphorus pesticides in medicinal plants commonly consumed in Iran

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Sarkhail Parisa

2012-08-01

Full Text Available Abstract The frequent occurrence of pesticide residues in herbal materials was indicated by previous studies. In this study, the concentration of some of the organophosphorus pesticides including parathion, malathion, diazinon and pirimiphos methyl in different kinds of medicinal plants were determined. The samples were collected randomly from ten local markets of different areas of Iran. At the detection limit of 0.5 ng g-1, parathion and pirimiphos methyl were not detected in any of the samples. Some amounts of malathion and diazinon were found in Zataria, Matricaria chamomile, Spearmint and Cumin Seed samples while, the concentrations of target organophosphorus pesticides in Borage samples were below the detection limits of the methods which could be a result of intensive transformation of organophosphorus pesticides by Borage. In addition the organophosphorus pesticides were detected in all of the samples below the maximum residue levels (MRLs proposed by the international organizations.

VALIDACIÓN DE UN MÉTODO PARA EL ANÁLISIS DE RESIDUALIDAD DE PLAGUICIDAS EN GULUPA (Passiflora edulis f. edulis

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Sara Juliana Olivo-Taborda

2016-01-01

Full Text Available La gulupa perteneciente a la familia Passifloraceae, es nativa del trópico americano, y se caracteriza por su exótico y distintivo aroma, cualidad que la hace atractiva para el mercado europeo, para lo cual debe de cumplir estándares de inocuidad sanitaria. Para ello, se evaluó un método para el análisis simultáneo de residualidad de parathion-methyl, malathion, deltamethrina y chlorothalonil en esta matriz. Se aplicó la técnica de QuEChERS, siguiendo una modificación del protocolo EN 15662, formado por tres etapas, la primera, consiste en una extracción con acetonitrilo (MeCN que incluye un proceso de precipitación salina de la muestra en medio acuoso. En el segundo paso, se realiza una limpieza utilizando diversos sorbentes para remover la mayoría de componentes coextraídos con los analitos, y por último se realiza el análisis instrumental empleando la cromatografía gaseosa. En el análisis de linealidad se obtuvieron correlaciones de 0,9991; 0,9998 y 0,9992 para parathion-methyl, malatihon y deltametrina respectivamente; que cumplieron las pruebas de significancia, pues chlorothalonil no cumplió con los parámetros requeridos para la validación. Se lograron límites de cuantificación de 0,035 mg/kg para parathion-methyl y 0,02 mg/kg para los otros dos compuestos validados con estimaciones de incertidumbre menores al 50%. Se cumplieron los criterios de precisión y exactitud establecidos en SANCO 12571, 2013, logrando una validación exitosa

Computerized tomography-guided neurolytic splanchnic nerve block

International Nuclear Information System (INIS)

Henriquet, Franco; De Martini, Giuseppe; Roy, Maria Teresa; Pretrolesi, Fabio; Martinoli, Carlo; Cariati, Maurizio; Fiorentini, Franco.

1997-01-01

Computerized tomography-guided neurolytic splanchnic nerve block is a technique for relieving abdominal cancer pain; the goal is the alcoholic neurolytic interruption of the sensitive structures in retroperitoneal space. Computerized tomography yields accurate anatomical detailing and the course for needle placement and alcohol spread. January, 1993, to July, 1996, twenty-one bilateral splanchnic nerve blocks were performed through the posterior access. Forty-eight hours after alcoholism. 14 patients (66%) had complete pain regression; 52% of the patients needed no analgesics for 6 to 54 days and only 9 patients (42%) needed another low opioid therapy. Complications included hypotension and diarrhea in all cases. One had a cardiac arrest and diet 8 days after the procedure. There were no other complications. The whole procedure usually lasted 60 min (range: 45 to 90 min). Splanchnic nerve neurolysis is a useful treatment in the patients with severe chronic abdominal pain. It is used as a second line treatment when large lesions change celia anatomy and complicate the percutaneous block of the celiac plexus. Endosulfan, Malathion and Methyl parathion, on the metabolic rate of the estuarine clam, Villorita cyprinoides var. cochinensis, have been investigated. The animals exposed to the lower sublethal concentrations of Endosulfan, Malthion and Methyl parathion consumed oxygen at the rate of 1.60, 1.98 and 2.09 ml. 0 2 g - 1 h -1 respectively, while at the higher concentrations of the pesticides, consumption of oxygen by the animal dropped to nearly half the control value. When compared to Malathion and Methyl parathion. Endosulfan induced animals recorded a greater reduction in her percentage deviation (from control) of oxygen consumption, possibly due to hypoxia induced by the pollutants

ENSAIO DE CONTROLE QUÍMICO ÀS PRINCIPAIS LAGARTAS E PERCEVEJOS DA SOJA EM GOIÁS ESSAY ON CHEMICAL CONTROL OF THE MAIN LARVAS AND CHINCH BUGS OF SOYBEAN IN GOIÁS

Directory of Open Access Journals (Sweden)

Valquíria da R. S. Veloso

2007-09-01

Full Text Available

Foi realizado em 1979/80, um ensaio de campo visando a avaliar a eficiência e adequar as doses dos inseticidas Bacillus thuringienses, Carbaryl , Clorpirifos , Deltametrina, Deltametrina + S 339, Endosulfan, Metil Paration, monocrotofos e triclorfon no combate a Anticarsia gemmatalis e Pseudoplusia includens. No mesmo ano, usaram-se os inseticidas Carbaryl Cyanamid AC 222 705, Deltametrina, Deltametrina + S 339, Dimetoato, Endosulfan, FMC 35001, Metil Paration, Monocrotofos, Permetrina, Phosalone + Paration Etil e Triciorfon, para o controle de Piezodorus guildinii, Nezara viridula e Euschistus heros. Todos os tratamentos foram aplicados em blocos ao acaso com quatro repetições. As avaliações de controle para lagartas foram efetuadas em 1, 2 e 7 dias após aplicação e para percevejos foram efetuadas em 2 e 7 dias após aplicação. Pelos resultados obtidos, verificou-se o seguinte: aA. gemmatalis foi sensível à maioria dos produtos; bapenas Clorpirifos Etil, Hetil Paration e Triclorfon não apresentaram eficiência acima de 80% para P. includens sete dias após a aplicação; c os inseticidas Monocrotofos, Metil Paration, Carbaryl e FMC 35001 mostraram eficiência acima de 80% para as espécies N. viridula e P. guildinii; Endosulfon e Dimetoato foram eficientes para controlar P. guildinii e E. heros.

During the 1979/80 planting period, a field test was performed to estimate the insecticides efficiency and adjust their doses in order to control Anticarsia qemmatalis and Pseudoplusia includens and also Piezodorus guildinii, Nezara viridula and Euschistus heros. For A. gemmatalis and P. includens control, the following insecticides were used: Baccilus thuringienses, Carbaryl, Clorpirifos, Decamethrin + S 339, Dimetoate, Endosulfan, Methyl Parathion, Monocrotophos and Triclorfon. For stink bugs, the

Methyl-Analyzer--whole genome DNA methylation profiling.

Science.gov (United States)

Xin, Yurong; Ge, Yongchao; Haghighi, Fatemeh G

2011-08-15

Methyl-Analyzer is a python package that analyzes genome-wide DNA methylation data produced by the Methyl-MAPS (methylation mapping analysis by paired-end sequencing) method. Methyl-MAPS is an enzymatic-based method that uses both methylation-sensitive and -dependent enzymes covering >80% of CpG dinucleotides within mammalian genomes. It combines enzymatic-based approaches with high-throughput next-generation sequencing technology to provide whole genome DNA methylation profiles. Methyl-Analyzer processes and integrates sequencing reads from methylated and unmethylated compartments and estimates CpG methylation probabilities at single base resolution. Methyl-Analyzer is available at http://github.com/epigenomics/methylmaps. Sample dataset is available for download at http://epigenomicspub.columbia.edu/methylanalyzer_data.html. fgh3@columbia.edu Supplementary data are available at Bioinformatics online.

Organophosphate insecticide poisoning of Canada geese in the Texas panhandle

Science.gov (United States)

White, D.H.; Mitchell, C.A.; Wynn, L.D.; Flickinger, Edward L.; Kolbe, E.J.

1982-01-01

Sixteen hundred waterfowl, mostly Canada Geese, died near Etter, Texas, in late January 1981 from anticholinesterase poisoning. Winter wheat in the area of the die-off had been treated with organophosphate insecticides to control greenbugs. Cholinesterase (ChE) levels in brains of a sample of geese found dead were 75% below normal, enough to account for death (Ludke et al. 1975). The gastrointestinal (G I) tracts of geese found dead were packed with winter wheat; gas chromatography techniques identified parathion and methyl parathion in the GI tract contents. Residues of both chemicals were confirmed by mass spectrometry. We recommend that less toxic materials, such as malathion, be used on grain crops when waterfowl are in the vicinity of treatment.

Cord blood buffy coat DNA methylation is comparable to whole cord blood methylation.

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Dou, John; Schmidt, Rebecca J; Benke, Kelly S; Newschaffer, Craig; Hertz-Picciotto, Irva; Croen, Lisa A; Iosif, Ana-Maria; LaSalle, Janine M; Fallin, M Daniele; Bakulski, Kelly M

2018-01-01

Cord blood DNA methylation is associated with numerous health outcomes and environmental exposures. Whole cord blood DNA reflects all nucleated blood cell types, while centrifuging whole blood separates red blood cells, generating a white blood cell buffy coat. Both sample types are used in DNA methylation studies. Cell types have unique methylation patterns and processing can impact cell distributions, which may influence comparability. We evaluated differences in cell composition and DNA methylation between cord blood buffy coat and whole cord blood samples. Cord blood DNA methylation was measured with the Infinium EPIC BeadChip (Illumina) in eight individuals, each contributing buffy coat and whole blood samples. We analyzed principal components (PC) of methylation, performed hierarchical clustering, and computed correlations of mean-centered methylation between pairs. We conducted moderated t-tests on single sites and estimated cell composition. DNA methylation PCs were associated with individual (P PC1 = 1.4 × 10 -9 ; P PC2 = 2.9 × 10 -5 ; P PC3 = 3.8 × 10 -5 ; P PC4 = 4.2 × 10 -6 ; P PC5 = 9.9 × 10 -13 , P PC6 = 1.3 × 10 -11 ) and not with sample type (P PC1-6 >0.7). Samples hierarchically clustered by individual. Pearson correlations of mean-centered methylation between paired samples ranged from r = 0.66 to r = 0.87. No individual site significantly differed between buffy coat and whole cord blood when adjusting for multiple comparisons (five sites had unadjusted Pcoat and whole cord blood are much lower than inter-individual variation, demonstrating that both sample preparation types can be analytically combined and compared.

Maternal intake of methyl-group donors affects DNA methylation of metabolic genes in infants.

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Pauwels, Sara; Ghosh, Manosij; Duca, Radu Corneliu; Bekaert, Bram; Freson, Kathleen; Huybrechts, Inge; Langie, Sabine A S; Koppen, Gudrun; Devlieger, Roland; Godderis, Lode

2017-01-01

Maternal nutrition during pregnancy and infant nutrition in the early postnatal period (lactation) are critically involved in the development and health of the newborn infant. The Maternal Nutrition and Offspring's Epigenome (MANOE) study was set up to assess the effect of maternal methyl-group donor intake (choline, betaine, folate, methionine) on infant DNA methylation. Maternal intake of dietary methyl-group donors was assessed using a food-frequency questionnaire (FFQ). Before and during pregnancy, we evaluated maternal methyl-group donor intake through diet and supplementation (folic acid) in relation to gene-specific ( IGF2 DMR, DNMT1 , LEP , RXRA ) buccal epithelial cell DNA methylation in 6 months old infants ( n  = 114) via pyrosequencing. In the early postnatal period, we determined the effect of maternal choline intake during lactation (in mothers who breast-fed for at least 3 months) on gene-specific buccal DNA methylation ( n  = 65). Maternal dietary and supplemental intake of methyl-group donors (folate, betaine, folic acid), only in the periconception period, was associated with buccal cell DNA methylation in genes related to growth ( IGF2 DMR), metabolism ( RXRA ), and appetite control ( LEP ). A negative association was found between maternal folate and folic acid intake before pregnancy and infant LEP (slope = -1.233, 95% CI -2.342; -0.125, p  = 0.0298) and IGF2 DMR methylation (slope = -0.706, 95% CI -1.242; -0.107, p  = 0.0101), respectively. Positive associations were observed for maternal betaine (slope = 0.875, 95% CI 0.118; 1.633, p  = 0.0241) and folate (slope = 0.685, 95% CI 0.245; 1.125, p  = 0.0027) intake before pregnancy and RXRA methylation. Buccal DNMT1 methylation in the infant was negatively associated with maternal methyl-group donor intake in the first and second trimester of pregnancy and negatively in the third trimester. We found no clear association between maternal choline intake

Nanocrystalline cerium oxide prepared from a carbonate precursor and its ability to breakdown biologically relevant organophosphates

Czech Academy of Sciences Publication Activity Database

Janoš, P.; Henych, Jiří; Pfeifer, J.; Zemanová, N.; Pilařová, V.; Milde, D.; Opletal, T.; Tolasz, Jakub; Malý, M.; Štengl, Václav

2017-01-01

Roč. 4, č. 6 (2017), s. 1283-1293 ISSN 2051-8153 R&D Projects: GA MŠk(CZ) LM2015073 Institutional support: RVO:61388980 Keywords : chemical warfare agents * parathion methyl * nanoparticles * hydrolysis * phosphopeptides * dephosphorylation Subject RIV: CA - Inorganic Chemistry OBOR OECD: Inorganic and nuclear chemistry Impact factor: 6.047, year: 2016

21 CFR 573.660 - Methyl glucoside-coconut oil ester.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Methyl glucoside-coconut oil ester. 573.660 Section 573.660 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... ANIMALS Food Additive Listing § 573.660 Methyl glucoside-coconut oil ester. Methyl glucoside-coconut oil...

21 CFR 173.250 - Methyl alcohol residues.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Methyl alcohol residues. 173.250 Section 173.250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD.... Methyl alcohol may be present in the following foods under the conditions specified: (a) In spice...

Pesticide resistance from historical agricultural chemical exposure in Thamnocephalus platyurus (Crustacea: Anostraca)

Energy Technology Data Exchange (ETDEWEB)

Brausch, John M. [Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, 1207 Gilbert Dr, Lubbock, TX 79416 (United States)], E-mail: john.brausch@ttu.edu; Smith, Philip N. [Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, 1207 Gilbert Dr, Lubbock, TX 79416 (United States)

2009-02-15

Extensive pesticide usage in modern agriculture represents a considerable anthropogenic stressor to freshwater ecosystems throughout the United States. Acute toxicity of three of the most commonly used agricultural pesticides (Methyl Parathion 4ec, Tempo SC Ultra, Karmex DF, and DDT) was determined in two different wild-caught strains of the fairy shrimp Thamnocephalus platyurus. Fairy shrimp collected from playas surrounded by native grasslands were between 200% and 400% more sensitive than fairy shrimp derived from playas in agricultural watersheds for Methyl Parathion 4ec, Tempo SC Ultra, and Karmex DF, likely due to the development of resistance. Additionally, reduced sensitivity to DDT was observed among fairy shrimp from agriculturally-impacted playas as compared to those from native grassland-dominated playas. These data suggest that fairy shrimp inhabiting playas in agricultural regions have developed some degree of resistance to a variety of agrochemicals in response to historical usage. - This manuscript discusses the potential effects of long-term pesticide usage on the development of resistance and cross-resistance on a non-target aquatic invertebrate.

Reduced expression of exocytotic proteins caused by anti-cholinesterase pesticides in Brachionus calyciflorus (Rotifera: Monogononta

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IA Pérez-Legaspi

Full Text Available AbstractThe organophosphate and carbamate pesticides methyl-parathion and carbaryl have a common action mechanism: they inhibit acetylcholinesterase enzyme by blocking the transmission of nerve impulses. However, they can alter the expression of exocytotic membrane proteins (SNARE, by modifying release of neurotransmitters and other substances. This study evaluated the adverse effects of the pesticides methyl-parathion and carbaryl on expression of SNARE proteins: Syntaxin-1, Syntaxin-4 and SNAP-23 in freshwater rotifer Brachionus calyciflorus. Protein expression of these three proteins was analyzed before and after exposure to these two pesticides by Western Blot. The expression of Syntaxin-1, Syntaxin-4 and SNAP-23 proteins in B. calyciflorussignificantly decreases with increasing concentration of either pesticides. This suggests that organophosphates and carbamates have adverse effects on expression of membrane proteins of exocytosis by altering the recognition, docking and fusion of presynaptic and vesicular membranes involved in exocytosis of neurotransmitters. Our results demonstrate that the neurotoxic effect of anticholinesterase pesticides influences the interaction of syntaxins and SNAP-25 and the proper assembly of the SNARE complex.

Identifying the cause of sediment toxicity in agricultural sediments: the role of pyrethroids and nine seldom-measured hydrophobic pesticides.

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Weston, Donald P; Ding, Yuping; Zhang, Minghua; Lydy, Michael J

2013-01-01

Few currently used agricultural pesticides are routinely monitored for in the environment. Even if concentrations are known, sediment LC(50) values are often lacking for common sediment toxicity testing species. To help fill this data gap, sediments in California's Central Valley were tested for nine hydrophobic pesticides seldom analyzed: abamectin, diazinon, dicofol, fenpropathrin, indoxacarb, methyl parathion, oxyfluorfen, propargite, and pyraclostrobin. Most were detected, but rarely at concentrations acutely toxic to Hyalella azteca or Chironomus dilutus. Only abamectin, fenpropathrin, and methyl parathion were found at concentrations of potential concern, and only in one or two samples. One-quarter of over 100 samples from agriculture-affected waterways exhibited toxicity, and in three-fourths of the toxic samples, pyrethroids exceeded concentrations expected to cause toxicity. The pyrethroid Bi-fen-thrin in particular, as well as lambda-cyhalothrin, cypermethrin, esfenvalerate, permethrin, and the organophosphate chlorpyrifos, were primarily responsible for the observed toxicity, rather than the more novel analytes, despite the fact that much of the sampling targeted areas of greatest use of the novel pesticides. Copyright © 2012 Elsevier Ltd. All rights reserved.

Structure, bioactivity, and synthesis of methylated flavonoids.

Science.gov (United States)

Wen, Lingrong; Jiang, Yueming; Yang, Jiali; Zhao, Yupeng; Tian, Miaomiao; Yang, Bao

2017-06-01

Methylated flavonoids are an important type of natural flavonoid derivative with potentially multiple health benefits; among other things, they have improved bioavailability compared with flavonoid precursors. Flavonoids have been documented to have broad bioactivities, such as anticancer, immunomodulation, and antioxidant activities, that can be elevated, to a certain extent, by methylation. Understanding the structure, bioactivity, and bioavailability of methylated flavonoids, therefore, is an interesting topic with broad potential applications. Though methylated flavonoids are widely present in plants, their levels are usually low. Because developing efficient techniques to produce these chemicals would likely be beneficial, we provide an overview of their chemical and biological synthesis. © 2017 New York Academy of Sciences.

Dietary and supplemental maternal methyl-group donor intake and cord blood DNA methylation.

Science.gov (United States)

Pauwels, Sara; Ghosh, Manosij; Duca, Radu Corneliu; Bekaert, Bram; Freson, Kathleen; Huybrechts, Inge; A S Langie, Sabine; Koppen, Gudrun; Devlieger, Roland; Godderis, Lode

2017-01-02

Maternal nutrition is critically involved in the development and health of the fetus. We evaluated maternal methyl-group donor intake through diet (methionine, betaine, choline, folate) and supplementation (folic acid) before and during pregnancy in relation to global DNA methylation and hydroxymethylation and gene specific (IGF2 DMR, DNMT1, LEP, RXRA) cord blood methylation. A total of 115 mother-infant pairs were enrolled in the MAternal Nutrition and Offspring's Epigenome (MANOE) study. The intake of methyl-group donors was assessed using a food-frequency questionnaire. LC-MS/MS and pyrosequencing were used to measure global and gene specific methylation, respectively. Dietary intake of methyl-groups before and during pregnancy was associated with changes in LEP, DNMT1, and RXRA cord blood methylation. Statistically significant higher cord blood LEP methylation was observed when mothers started folic acid supplementation more than 6 months before conception compared with 3-6 months before conception (34.6 ± 6.3% vs. 30.1 ± 3.6%, P = 0.011, LEP CpG1) or no folic acid used before conception (16.2 ± 4.4% vs. 13.9 ± 3%, P = 0.036 for LEP CpG3 and 24.5 ± 3.5% vs. 22.2 ± 3.5%, P = 0.045 for LEP mean CpG). Taking folic acid supplements during the entire pregnancy resulted in statistically significantly higher cord blood RXRA methylation as compared with stopping supplementation in the second trimester (12.3 ± 1.9% vs. 11.1 ± 2%, P = 0.008 for RXRA mean CpG). To conclude, long-term folic acid use before and during pregnancy was associated with higher LEP and RXRA cord blood methylation, respectively. To date, pregnant women are advised to take a folic acid supplement of 400 µg/day from 4 weeks before until 12 weeks of pregnancy. Our results suggest significant epigenetic modifications when taking a folic acid supplement beyond the current advice.

Genome-wide methylation analysis identifies differentially methylated CpG loci associated with severe obesity in childhood.

Science.gov (United States)

Huang, R C; Garratt, E S; Pan, H; Wu, Y; Davis, E A; Barton, S J; Burdge, G C; Godfrey, K M; Holbrook, J D; Lillycrop, K A

2015-01-01

Childhood obesity is a major public health issue. Here we investigated whether differential DNA methylation was associated with childhood obesity. We studied DNA methylation profiles in whole blood from 78 obese children (mean BMI Z-score: 2.6) and 71 age- and sex-matched controls (mean BMI Z-score: 0.1). DNA samples from obese and control groups were pooled and analyzed using the Infinium HumanMethylation450 BeadChip array. Comparison of the methylation profiles between obese and control subjects revealed 129 differentially methylated CpG (DMCpG) loci associated with 80 unique genes that had a greater than 10% difference in methylation (P-value obesity were validated using sodium bisulfite pyrosequencing across loci within the FYN, PIWIL4, and TAOK3 genes in individual subjects. Three CpG loci within FYN were hypermethylated in obese individuals (all P obesity was associated with lower methylation of CpG loci within PIWIL4 (P = 0.003) and TAOK3 (P = 0.001). After building logistic regression models, we determined that a 1% increase in methylation in TAOK3, multiplicatively decreased the odds of being obese by 0.91 (95% CI: 0.86 - 0.97), and an increase of 1% methylation in FYN CpG3, multiplicatively increased the odds of being obese by 1.03 (95% CI: 0.99 - 1.07). In conclusion, these findings provide evidence that childhood obesity is associated with specific DNA methylation changes in whole blood, which may have utility as biomarkers of obesity risk.

LIQUID CULTURE FOR ISOLATING MICROORGANISMS WITH POTENTIAL TO DEGRADE METHYL PARATHION FROM AGRICULTURAL SOILS AND ORGANIC WASTE CULTIVO LÍQUIDO PARA AISLAR MICROORGANISMOS CON POTENCIAL PARA DEGRADAR METIL PARATIÓN A PARTIR DE SUELOS AGRÍCOLAS Y RESIDUOS ORGÁNICOS

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L. R. Botero

2012-12-01

Full Text Available The search for microorganisms with high capacity for pesticide degradation is a very interesting attempt to approach bioremediation strategies in order to prevent contamination. This study evaluates the potential of agricultural soils and solid organic waste cultures microbial isolation as a strategy for screening microorganisms with potential for Methyl parathion (MP degradation. For the study, microbial consortia were recovered from the liquid fraction of suspension cultures of agricultural soils and solid organic waste. Then, the MP degradation ability and its toxic effect on microbial activity were determined during microbial incubations under laboratory controlled conditions. The results showed that it is not possible to recover the active microorganisms that have potential to degrade the MP from the agricultural soils. However, an active consortium that would degrade both MP and its degradation products was isolated from the organic solid waste.La búsqueda de microorganismos con alta capacidad de degradación de los plaguicidas es un intento muy interesante de acercarse a las estrategias de biorremediación con el fin de evitar la contaminación. Este estudio evalúa el potencial del cultivo de microorganismos de suelos agrícolas y de residuos sólidos orgánicos como una estrategia para la detección de microorganismos con potencial para el metil paratión (MP la degradación. Para el estudio, consorcios microbianos fueron recuperados de la fracción líquida de los cultivos en suspensión de los suelos agrícolas y los residuos sólidos orgánicos. La capacidad de degradación de la MP y su efecto tóxico sobre la actividad microbiana se determinó durante las incubaciones de los microorganismos en condiciones controladas de laboratorio. Los resultados mostraron que no es posible recuperar los microorganismos activos que tienen potencial para degradar el MP de los suelos agrícolas. Sin embargo, un consorcio activo que degradar

Halloysite nanotubes-titanium dioxide as a solid-phase microextraction coating combined with negative corona discharge-ion mobility spectrometry for the determination of parathion.

Science.gov (United States)

Saraji, Mohammad; Jafari, Mohammad Taghi; Mossaddegh, Mehdi

2016-07-05

Halloysite nanotubes-titanium dioxide (HNTs-TiO2) as a biocompatible environmentally friendly solid-phase microextraction (SPME) fiber coating was prepared. HNTs-TiO2 was chemically coated on the surface of a fused-silica fiber using a sol-gel process. Parathion as an organophosphorus pesticide was selected as a model compound to investigate the extraction efficiency of the fiber. The extracted analyte was detected by negative corona discharge-ion mobility spectrometer (NCD-IMS). The effective parameters on the extraction efficiency, such as salt effect, extraction temperature and extraction time were investigated and optimized. The extraction efficiency of HNTs-TiO2 fiber was compared with bare-silica (sol-gel based coating without HNTs-TiO2), HNTs, carbon nanotubes and commercial SPME fibers (PA, PDMS, and PDMS-DVB). The HNTs-TiO2 fiber showed highest extraction efficiency among the studied fibers. The intra- and inter-day relative standard deviations were found to be 4.3 and 6.3%, respectively. The limit of detection and limit of quantification values were 0.03 and 0.1 μg L(-1), respectively. The dynamic range of the method was in the range of 0.1-25 μg L(-1). The spiking recoveries were between 85 (±9) and 97 (±6). The SPME-HNTs-TiO2 combined with NCD-IMS was successfully applied for the determination of parathion in apple, strawberry, celery and water samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Health Risk Assessment of Pesticide Residues via Dietary Intake of Market Vegetables from Dhaka, Bangladesh

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Md. Shakhaoat Hossain

2013-02-01

Full Text Available The present study was designed to assess the health risk of pesticide residues via dietary intake of vegetables collected from four top agro-based markets of Dhaka, Bangladesh. High performance liquid chromatography with a photo diode array detector (HPLC-PDA was used to determine six organophosphorus (chlorpyrifos, fenitrothion, parathion, ethion, acephate, fenthion, two carbamate (carbaryl and carbofuran and one pyrethroid (cypermethrin pesticide residues in twelve samples of three common vegetables (tomato, lady’s finger and brinjal. Pesticide residues ranged from below detectable limit (<0.01 to 0.36 mg/kg. Acephate, chlorpyrifos, ethion, carbaryl and cypermethrin were detected in only one sample, while co-occurrence occurred twice for fenitrothion and parathion. Apart from chlorpyrifos in tomato and cypermethrin in brinjal, all pesticide residues exceeded the maximum residue limit (MRL. Hazard risk index (HRI for ethion (10.12 and carbaryl (1.09 was found in lady’s finger and tomato, respectively. Rest of the pesticide residues were classified as not a health risk. A continuous monitoring and strict regulation should be enforced regarding control of pesticide residues in vegetables and other food commodities.

DNA methylation-based variation between human populations.

Science.gov (United States)

Kader, Farzeen; Ghai, Meenu

2017-02-01

Several studies have proved that DNA methylation affects regulation of gene expression and development. Epigenome-wide studies have reported variation in methylation patterns between populations, including Caucasians, non-Caucasians (Blacks), Hispanics, Arabs, and numerous populations of the African continent. Not only has DNA methylation differences shown to impact externally visible characteristics, but is also a potential biomarker for underlying racial health disparities between human populations. Ethnicity-related methylation differences set their mark during early embryonic development. Genetic variations, such as single-nucleotide polymorphisms and environmental factors, such as age, dietary folate, socioeconomic status, and smoking, impacts DNA methylation levels, which reciprocally impacts expression of phenotypes. Studies show that it is necessary to address these external influences when attempting to differentiate between populations since the relative impacts of these factors on the human methylome remain uncertain. The present review summarises several reported attempts to establish the contribution of differential DNA methylation to natural human variation, and shows that DNA methylation could represent new opportunities for risk stratification and prevention of several diseases amongst populations world-wide. Variation of methylation patterns between human populations is an exciting prospect which inspires further valuable research to apply the concept in routine medical and forensic casework. However, trans-generational inheritance needs to be quantified to decipher the proportion of variation contributed by DNA methylation. The future holds thorough evaluation of the epigenome to understand quantification, heritability, and the effect of DNA methylation on phenotypes. In addition, methylation profiling of the same ethnic groups across geographical locations will shed light on conserved methylation differences in populations.

Are one or two dangerous? Methyl salicylate exposure in toddlers.

Science.gov (United States)

Davis, Jonathan E

2007-01-01

Serious toxicity can result from exposure to small amounts of methyl salicylate. Methyl salicylate is widely available as a component in many over-the-counter brands of creams, ointments, lotions, liniments and medicated oils intended for topical application to relieve musculoskeletal aches and pains. Among the most potent forms of methyl salicylate is oil of wintergreen (98% methyl salicylate). Other products with varying concentrations of methyl salicylate are ubiquitous throughout many parts of the world, including a number of products marketed as Asian herbal remedies. The toxic potential of all of these formulations is often underestimated by health care providers and the general public. A comprehensive review of the existing medical literature on methyl salicylate poisoning was performed, and data compiled over the past two decades by the American Association of Poison Control Centers (AAPCC) was examined. Methyl salicylate continues to be a relatively common source of pediatric exposures. Persistent reports of life-threatening and fatal toxicity were found. In children less than 6 years of age, a teaspoon (5 mL) or less of oil of wintergreen has been implicated in several well-documented deaths. More needs to be done to educate both health care providers and the general public regarding the dangers of these widely available formulations.

Chromosome-wide mapping of DNA methylation patterns in normal and malignant prostate cells reveals pervasive methylation of gene-associated and conserved intergenic sequences

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De Marzo Angelo M

2011-06-01

Full Text Available Abstract Background DNA methylation has been linked to genome regulation and dysregulation in health and disease respectively, and methods for characterizing genomic DNA methylation patterns are rapidly emerging. We have developed/refined methods for enrichment of methylated genomic fragments using the methyl-binding domain of the human MBD2 protein (MBD2-MBD followed by analysis with high-density tiling microarrays. This MBD-chip approach was used to characterize DNA methylation patterns across all non-repetitive sequences of human chromosomes 21 and 22 at high-resolution in normal and malignant prostate cells. Results Examining this data using computational methods that were designed specifically for DNA methylation tiling array data revealed widespread methylation of both gene promoter and non-promoter regions in cancer and normal cells. In addition to identifying several novel cancer hypermethylated 5' gene upstream regions that mediated epigenetic gene silencing, we also found several hypermethylated 3' gene downstream, intragenic and intergenic regions. The hypermethylated intragenic regions were highly enriched for overlap with intron-exon boundaries, suggesting a possible role in regulation of alternative transcriptional start sites, exon usage and/or splicing. The hypermethylated intergenic regions showed significant enrichment for conservation across vertebrate species. A sampling of these newly identified promoter (ADAMTS1 and SCARF2 genes and non-promoter (downstream or within DSCR9, C21orf57 and HLCS genes hypermethylated regions were effective in distinguishing malignant from normal prostate tissues and/or cell lines. Conclusions Comparison of chromosome-wide DNA methylation patterns in normal and malignant prostate cells revealed significant methylation of gene-proximal and conserved intergenic sequences. Such analyses can be easily extended for genome-wide methylation analysis in health and disease.

Identification of Differentially Methylated Sites with Weak Methylation Effects

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Hong Tran

2018-02-01

Full Text Available Deoxyribonucleic acid (DNA methylation is an epigenetic alteration crucial for regulating stress responses. Identifying large-scale DNA methylation at single nucleotide resolution is made possible by whole genome bisulfite sequencing. An essential task following the generation of bisulfite sequencing data is to detect differentially methylated cytosines (DMCs among treatments. Most statistical methods for DMC detection do not consider the dependency of methylation patterns across the genome, thus possibly inflating type I error. Furthermore, small sample sizes and weak methylation effects among different phenotype categories make it difficult for these statistical methods to accurately detect DMCs. To address these issues, the wavelet-based functional mixed model (WFMM was introduced to detect DMCs. To further examine the performance of WFMM in detecting weak differential methylation events, we used both simulated and empirical data and compare WFMM performance to a popular DMC detection tool methylKit. Analyses of simulated data that replicated the effects of the herbicide glyphosate on DNA methylation in Arabidopsis thaliana show that WFMM results in higher sensitivity and specificity in detecting DMCs compared to methylKit, especially when the methylation differences among phenotype groups are small. Moreover, the performance of WFMM is robust with respect to small sample sizes, making it particularly attractive considering the current high costs of bisulfite sequencing. Analysis of empirical Arabidopsis thaliana data under varying glyphosate dosages, and the analysis of monozygotic (MZ twins who have different pain sensitivities—both datasets have weak methylation effects of <1%—show that WFMM can identify more relevant DMCs related to the phenotype of interest than methylKit. Differentially methylated regions (DMRs are genomic regions with different DNA methylation status across biological samples. DMRs and DMCs are essentially the same

Evaluation of ozonation technique for pesticide residue removal and its effect on ascorbic acid, cyanidin-3-glucoside, and polyphenols in apple (Malus domesticus) fruits.

Science.gov (United States)

Swami, Saurabh; Muzammil, Raunaq; Saha, Supradip; Shabeer, Ahammed; Oulkar, Dasharath; Banerjee, Kaushik; Singh, Shashi Bala

2016-05-01

Ozonated water dip technique was evaluated for the detoxification of six pesticides, i.e., chlorpyrifos, cypermethrin, azoxystrobin, hexaconazole, methyl parathion, and chlorothalonil from apple fruits. Results revealed that ozonation was better than washing alone. Ozonation for 15 min decreased residues of the test pesticides in the range of from 26.91 to 73.58%, while ozonation for 30 min could remove the pesticide residues by 39.39-95.14 % compared to 19.05-72.80 % by washing. Cypermethrin was the least removed pesticide by washing as well as by ozonation. Chlorothalonil, chlorpyrifos, and azoxystrobin were removed up to 71.45-95.14 % in a 30-min ozonation period. In case of methyl parathion removal, no extra advantage could be obtained by ozonation. The HPLC analysis indicated that ozonation also affected adversely the ascorbic acid and cyanidin-3-glucoside content of apples. However, 11 polyphenols studied showed a mixed trend. Gallic acid, 3,4-dihydroxybenzoic acid, catechin, epicatechin, p-coumaric acid, quercetin-3-O-glucoside, quercetin, and kaempferol were found to decrease while syringic acid, rutin, and resveratrol were found to increase in 30-min ozonation.

Insufficient DNA methylation affects healthy aging and promotes age-related health problems.

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Liu, Liang; van Groen, Thomas; Kadish, Inga; Li, Yuanyuan; Wang, Deli; James, Smitha R; Karpf, Adam R; Tollefsbol, Trygve O

2011-08-01

DNA methylation plays an integral role in development and aging through epigenetic regulation of genome function. DNA methyltransferase 1 (Dnmt1) is the most prevalent DNA methyltransferase that maintains genomic methylation stability. To further elucidate the function of Dnmt1 in aging and age-related diseases, we exploited the Dnmt1+/- mouse model to investigate how Dnmt1 haploinsufficiency impacts the aging process by assessing the changes of several major aging phenotypes. We confirmed that Dnmt1 haploinsufficiency indeed decreases DNA methylation as a result of reduced Dnmt1 expression. To assess the effect of Dnmt1 haploinsufficiency on general body composition, we performed dual-energy X-ray absorptiometry analysis and showed that reduced Dnmt1 activity decreased bone mineral density and body weight, but with no significant impact on mortality or body fat content. Using behavioral tests, we demonstrated that Dnmt1 haploinsufficiency impairs learning and memory functions in an age-dependent manner. Taken together, our findings point to the interesting likelihood that reduced genomic methylation activity adversely affects the healthy aging process without altering survival and mortality. Our studies demonstrated that cognitive functions of the central nervous system are modulated by Dnmt1 activity and genomic methylation, highlighting the significance of the original epigenetic hypothesis underlying memory coding and function.

Whole-genome methylation caller designed for methyl- DNA ...

African Journals Online (AJOL)

etchie

2013-02-20

Feb 20, 2013 ... Our method uses a single-CpG-resolution, whole-genome methylation ... Key words: Methyl-DNA immunoprecipitation, next-generation sequencing, ...... methylation is prevalent in embryonic stem cells andmaybe mediated.

Role of methionine on epigenetic modification of DNA methylation and gene expression in animals

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Naifeng Zhang

2018-03-01

Full Text Available DNA methylation is one of the main epigenetic phenomena affecting gene expression. It is an important mechanism for the development of embryo, growth and health of animals. As a key nutritional factor limiting the synthesis of protein, methionine serves as the precursor of S-adenosylmethionine (SAM in the hepatic one-carbon metabolism. The dietary fluctuation of methionine content can alter the levels of metabolic substrates in one-carbon metabolism, e.g., the SAM, S-adenosylhomocysteine (SAH, and change the expression of genes related to the growth and health of animals by DNA methylation reactions. The ratio of SAM to SAH is called ‘methylation index’ but it should be carefully explained because the complexity of methylation reaction. Alterations of methylation in a specific cytosine-guanine (CpG site, rather than the whole promoter region, might be enough to change gene expression. Aberrant methionine cycle may provoke molecular changes of one-carbon metabolism that results in deregulation of cellular hemostasis and health problems. The importance of DNA methylation has been underscored but the mechanisms of methionine affecting DNA methylation are poorly understood. Nutritional epigenomics provides a promising insight into the targeting epigenetic changes in animals from a nutritional standpoint, which will deepen and expand our understanding of genes, molecules, tissues, and animals in which methionine alteration influences DNA methylation and gene expression. Keywords: Epigenetics, Methionine, DNA methylation, Gene expression, Epigenetic modification

Identification of endometrial cancer methylation features using combined methylation analysis methods.

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Michael P Trimarchi

Full Text Available DNA methylation is a stable epigenetic mark that is frequently altered in tumors. DNA methylation features are attractive biomarkers for disease states given the stability of DNA methylation in living cells and in biologic specimens typically available for analysis. Widespread accumulation of methylation in regulatory elements in some cancers (specifically the CpG island methylator phenotype, CIMP can play an important role in tumorigenesis. High resolution assessment of CIMP for the entire genome, however, remains cost prohibitive and requires quantities of DNA not available for many tissue samples of interest. Genome-wide scans of methylation have been undertaken for large numbers of tumors, and higher resolution analyses for a limited number of cancer specimens. Methods for analyzing such large datasets and integrating findings from different studies continue to evolve. An approach for comparison of findings from a genome-wide assessment of the methylated component of tumor DNA and more widely applied methylation scans was developed.Methylomes for 76 primary endometrial cancer and 12 normal endometrial samples were generated using methylated fragment capture and second generation sequencing, MethylCap-seq. Publically available Infinium HumanMethylation 450 data from The Cancer Genome Atlas (TCGA were compared to MethylCap-seq data.Analysis of methylation in promoter CpG islands (CGIs identified a subset of tumors with a methylator phenotype. We used a two-stage approach to develop a 13-region methylation signature associated with a "hypermethylator state." High level methylation for the 13-region methylation signatures was associated with mismatch repair deficiency, high mutation rate, and low somatic copy number alteration in the TCGA test set. In addition, the signature devised showed good agreement with previously described methylation clusters devised by TCGA.We identified a methylation signature for a "hypermethylator phenotype" in

Delivery type not associated with global methylation at birth

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Virani Shama

2012-06-01

Full Text Available Abstract Background Birth by cesarean delivery (CD as opposed to vaginal delivery (VD is associated with altered health outcomes later in life, including respiratory disorders, allergies and risk of developing type I diabetes. Epigenetic gene regulation is a proposed mechanism by which early life exposures affect later health outcomes. Previously, type of delivery has been found to be associated with differences in global methylation levels, but the sample sizes have been small. We measured global methylation in a large birth cohort to identify whether type of delivery is associated with epigenetic changes. Methods DNA was isolated from cord blood collected from the University of Michigan Women’s & Children Hospital and bisulfite-converted. The Luminometric Methylation Assay (LUMA and LINE-1 methylation assay were run on all samples in duplicate. Results Global methylation data at CCGG sites throughout the genome, as measured by LUMA, were available from 392 births (52% male; 65% CD, and quantitative methylation levels at LINE-1 repetitive elements were available for 407 births (52% male; 64% CD. LUMA and LINE-1 methylation measurements were negatively correlated in this population (Spearman’s r = −0.13, p =0.01. LUMA measurements were significantly lower for total CD and planned CD, but not emergency CD when compared to VD (median VD = 74.8, median total CD = 74.4, p = 0.03; median planned CD = 74.2, p = 0.02; median emergency CD = 75.3, p = 0.39. However, this association did not persist when adjusting for maternal age, maternal smoking and infant gender. Furthermore, total CD deliveries, planned CD and emergency CD deliveries were not associated with LINE-1 measurements as compared to VD (median VD = 82.2, median total CD = 81.9, p = 0.19; median planned CD = 81.9, p = 0.19; median emergency CD = 82.1, p = 0.52. This lack of association held when adjusting for maternal age

Methylation of food commodities during fumigation with methyl bromide

International Nuclear Information System (INIS)

Starratt, A.N.; Bond, E.J.

1990-01-01

Sites of methylation in several commodities (wheat, oatmeal, peanuts, almonds, apples, oranges, maize, alfalfa and potatoes) during fumigation with 14 C-methyl bromide were studied. Differences were observed in levels of the major volatiles: methanol, dimethyl sulphide and methyl mercaptan, products of O- and S-methylation, resulting from treatment of the fumigated materials with 1N sodium hydroxide. In studies of maize and wheat, histidine was the amino acid which underwent the highest level of N-methylation. (author). 24 refs, 3 tabs

Longitudinal changes in glucocorticoid receptor exon 1F methylation and psychopathology after military deployment.

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Schür, R R; Boks, M P; Rutten, B P F; Daskalakis, N P; de Nijs, L; van Zuiden, M; Kavelaars, A; Heijnen, C J; Joëls, M; Kahn, R S; Geuze, E; Vermetten, E; Vinkers, C H

2017-07-25

Several cross-sectional studies have demonstrated the relevance of DNA methylation of the glucocorticoid receptor exon 1 F region (GR-1 F ) for trauma-related psychopathology. We conducted a longitudinal study to examine GR-1 F methylation changes over time in relation to trauma exposure and the development of post-deployment psychopathology. GR-1 F methylation (52 loci) was quantified using pyrosequencing in whole blood of 92 military men 1 month before and 6 months after a 4-month deployment period to Afghanistan. GR-1 F methylation overall (mean methylation and the number of methylated loci) and functional methylation (methylation at loci associated with GR exon 1 F expression) measures were examined. We first investigated the effect of exposure to potentially traumatic events during deployment on these measures. Subsequently, changes in GR-1 F methylation were related to changes in mental health problems (total Symptom Checklist-90 score) and posttraumatic stress disorder (PTSD) symptoms (Self-Report Inventory for PTSD). Trauma exposure during deployment was associated with an increase in all methylation measures, but development of mental health problems 6 months after deployment was only significantly associated with an increased functional methylation. Emergence of post-deployment PTSD symptoms was not related to increased functional methylation over time. Pre-deployment methylation levels did not predict post-deployment psychopathology. To our knowledge, this is the first study to prospectively demonstrate trauma-related increases in GR-1 F methylation, and it shows that only increases at specific functionally relevant sites predispose for post-deployment psychopathology.

Microsomal biotransformation of chlorpyrifos, parathion and fenthion in rainbow trout (Oncorhynchus mykiss) and coho salmon (Oncorhynchus kisutch): mechanistic insights into interspecific differences in toxicity

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Lavado, Ramon

2010-01-01

Rainbow trout often serve as a surrogate species evaluating xenobiotic toxicity in cold-water species including other salmonids of the same genus, which are listed as threatened or endangered. Biotransformation tends to show species-specific patterns that influence susceptibility to xenobiotic toxicity, particularly organophoshpate insecticides (OPs). To evaluate the contribution of biotransformation in the mechanism of toxicity of three organophosphate (phosphorothionate) insecticides, chlorpyrifos, parathion and fenthion, microsomal bioactivation and detoxification pathways were measured in gills, liver and olfactory tissues in juvenile rainbow trout (Oncorhynchus mykiss) and compared to juvenile coho salmon (Oncorhynchus kisutch). Consistent with species differences in acute toxicity, significantly higher chlorpyrifos bioactivation was found in liver microsomes of rainbow trout (up to 2-fold) when compared with coho salmon. Although bioactivation to the oxon was observed, the catalytic efficiency towards chlorpyrifos dearylation (detoxification) was significantly higher in liver for both species (1.82 and 0.79 for trout and salmon, respectively) when compared to desulfuration (bioactivation). Bioactivation of parathion to paraoxon was significantly higher (up to 2.2-fold) than detoxification to p-nitrophenol in all tissues of both species with rates of conversion in rainbow trout, again significantly higher than coho salmon. Production of fenoxon and fenthion sulfoxides from fenthion was detected only in liver and gills of both species with activities in rainbow trout significantly higher than coho salmon. NADPH-Dependent hydrolysis of fenthion was observed in all tissues, and was the only activity detected in olfactory tissues. These results indicate rainbow trout are more sensitive than coho salmon to the acute toxicity of OP pesticides because trout have higher catalytic rates of oxon formation. Thus, rainbow trout may serve as a conservative surrogate

Genome-Wide DNA Methylation Profiles of Phlegm-Dampness Constitution

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Haiqiang Yao

2018-03-01

Full Text Available Background/Aims: Metabolic diseases are leading health concerns in today’s global society. In traditional Chinese medicine (TCM, one body type studied is the phlegm-dampness constitution (PC, which predisposes individuals to complex metabolic disorders. Genomic studies have revealed the potential metabolic disorders and the molecular features of PC. The role of epigenetics in the regulation of PC, however, is unknown. Methods: We analyzed a genome-wide DNA methylation in 12 volunteers using Illumina Infinium Human Methylation450 BeadChip on peripheral blood mononuclear cells (PBMCs. Eight volunteers had PC and 4 had balanced constitutions. Results: Methylation data indicated a genome-scale hyper-methylation pattern in PC. We located 288 differentially methylated probes (DMPs. A total of 256 genes were mapped, and some of these were metabolic-related. SQSTM1, DLGAP2 and DAB1 indicated diabetes mellitus; HOXC4 and SMPD3, obesity; and GRWD1 and ATP10A, insulin resistance. According to Ingenuity Pathway Analysis (IPA, differentially methylated genes were abundant in multiple metabolic pathways. Conclusion: Our results suggest the potential risk for metabolic disorders in individuals with PC. We also explain the clinical characteristics of PC with DNA methylation features.

MethylMix 2.0: an R package for identifying DNA methylation genes.

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Cedoz, Pierre-Louis; Prunello, Marcos; Brennan, Kevin; Gevaert, Olivier

2018-04-14

DNA methylation is an important mechanism regulating gene transcription, and its role in carcinogenesis has been extensively studied. Hyper and hypomethylation of genes is a major mechanism of gene expression deregulation in a wide range of diseases. At the same time, high-throughput DNA methylation assays have been developed generating vast amounts of genome wide DNA methylation measurements. We developed MethylMix, an algorithm implemented in R to identify disease specific hyper and hypomethylated genes. Here we present a new version of MethylMix that automates the construction of DNA-methylation and gene expression datasets from The Cancer Genome Atlas (TCGA). More precisely, MethylMix 2.0 incorporates two major updates: the automated downloading of DNA methylation and gene expression datasets from TCGA and the automated preprocessing of such datasets: value imputation, batch correction and CpG sites clustering within each gene. The resulting datasets can subsequently be analyzed with MethylMix to identify transcriptionally predictive methylation states. We show that the Differential Methylation Values created by MethylMix can be used for cancer subtyping. olivier.gevaert@stanford.edu. https://bioconductor.org/packages/release/bioc/manuals/MethylMix/man/MethylMix.pdf. MethylMix 2.0 was implemented as an R package and is available in bioconductor.

Global DNA methylation analysis using methyl-sensitive amplification polymorphism (MSAP).

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Yaish, Mahmoud W; Peng, Mingsheng; Rothstein, Steven J

2014-01-01

DNA methylation is a crucial epigenetic process which helps control gene transcription activity in eukaryotes. Information regarding the methylation status of a regulatory sequence of a particular gene provides important knowledge of this transcriptional control. DNA methylation can be detected using several methods, including sodium bisulfite sequencing and restriction digestion using methylation-sensitive endonucleases. Methyl-Sensitive Amplification Polymorphism (MSAP) is a technique used to study the global DNA methylation status of an organism and hence to distinguish between two individuals based on the DNA methylation status determined by the differential digestion pattern. Therefore, this technique is a useful method for DNA methylation mapping and positional cloning of differentially methylated genes. In this technique, genomic DNA is first digested with a methylation-sensitive restriction enzyme such as HpaII, and then the DNA fragments are ligated to adaptors in order to facilitate their amplification. Digestion using a methylation-insensitive isoschizomer of HpaII, MspI is used in a parallel digestion reaction as a loading control in the experiment. Subsequently, these fragments are selectively amplified by fluorescently labeled primers. PCR products from different individuals are compared, and once an interesting polymorphic locus is recognized, the desired DNA fragment can be isolated from a denaturing polyacrylamide gel, sequenced and identified based on DNA sequence similarity to other sequences available in the database. We will use analysis of met1, ddm1, and atmbd9 mutants and wild-type plants treated with a cytidine analogue, 5-azaC, or zebularine to demonstrate how to assess the genetic modulation of DNA methylation in Arabidopsis. It should be noted that despite the fact that MSAP is a reliable technique used to fish for polymorphic methylated loci, its power is limited to the restriction recognition sites of the enzymes used in the genomic

Systemic effects of chronically administered methyl prednisolonate and methyl 17-deoxyprednisolonate.

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Olejniczak, E; Lee, H J

1984-06-01

The systemic activities of methyl prednisolonate and methyl 17-deoxyprednisolonate (1) were studied in rats. Methyl 17-deoxyprednisolonate produced significant changes in the amount of sodium ion (decreased) and potassium ion (increased) in urine; however, methyl prednisolonate had no effect on electrolyte balance. Both methyl prednisolonate and methyl 17-deoxyprednisolonate had no effect on liver glycogen content, plasma corticosterone level and relative adrenal weight. In contrast, the parent compound prednisolone caused a significant decrease in liver glycogen content, plasma corticosterone level and relative adrenal weight.

Methyl Jasmonate: An Alternative for Improving the Quality and Health Properties of Fresh Fruits

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Marjorie Reyes-Díaz

2016-05-01

Full Text Available Methyl jasmonate (MeJA is a plant growth regulator belonging to the jasmonate family. It plays an important role as a possible airborne signaling molecule mediating intra- and inter-plant communications and modulating plant defense responses, including antioxidant systems. Most assessments of this compound have dealt with post-harvest fruit applications, demonstrating induced plant resistance against the detrimental impacts of storage (chilling injuries and pathogen attacks, enhancing secondary metabolites and antioxidant activity. On the other hand, the interactions between MeJA and other compounds or technological tools for enhancing antioxidant capacity and quality of fruits were also reviewed. The pleiotropic effects of MeJA have raisen numerous as-yet unanswered questions about its mode of action. The aim of this review was endeavored to clarify the role of MeJA on improving pre- and post-harvest fresh fruit quality and health properties. Interestingly, the influence of MeJA on human health will be also discussed.

Influência do meio reacional no comportamento fotoquímico do inseticida paration etílico Influence of reaction mean in the behavior photochemical of insecticide ethyl parathion

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Francismário Ferreira Santos

2002-02-01

Full Text Available The photodegradation of parathion in natural and dezionised waters was studied under irradiation at two different wavelengths: 280 nm and 313 nm. The influence of humic acids was evaluated. The results demonstrated that the degradation occurred only due to photochemical processes. The chemical hydrolysis and biological processes can be neglected in this case. The addition of humic acids did not increase the photodegradation rate in either water samples (natural or dezionised. In alkaline solutions the photodegradation rate was higher in dezionised water when compared to natural waters. The kinetic degradation in all experiments obeyed a first order reaction pattern.

DNA methylation signatures of educational attainment

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van Dongen, Jenny; Bonder, Marc Jan; Dekkers, Koen F.; Nivard, Michel G.; van Iterson, Maarten; Willemsen, Gonneke; Beekman, Marian; van der Spek, Ashley; van Meurs, Joyce B. J.; Franke, Lude; Heijmans, Bastiaan T.; van Duijn, Cornelia M.; Slagboom, P. Eline; Boomsma, Dorret I.; BIOS consortium

2018-03-01

Educational attainment is a key behavioural measure in studies of cognitive and physical health, and socioeconomic status. We measured DNA methylation at 410,746 CpGs (N = 4152) and identified 58 CpGs associated with educational attainment at loci characterized by pleiotropic functions shared with neuronal, immune and developmental processes. Associations overlapped with those for smoking behaviour, but remained after accounting for smoking at many CpGs: Effect sizes were on average 28% smaller and genome-wide significant at 11 CpGs after adjusting for smoking and were 62% smaller in never smokers. We examined sources and biological implications of education-related methylation differences, demonstrating correlations with maternal prenatal folate, smoking and air pollution signatures, and associations with gene expression in cis, dynamic methylation in foetal brain, and correlations between blood and brain. Our findings show that the methylome of lower-educated people resembles that of smokers beyond effects of their own smoking behaviour and shows traces of various other exposures.

Self-assembly Ag nanoparticle monolayer film as SERS Substrate for pesticide detection

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Zhang, Li, E-mail: zhlisuzh@163.com [School of Chemistry and Life Science, Anhui Key Laboratory of Spin Electron and Nanomaterials (Cultivating Base), Suzhou University, SuZhou 234000 (China)

2013-04-01

A self-assembled protocol is introduced to provide effective platforms for the fabrication of ordered Ag nanosized monolayer film. The assembled Ag nanosized monolayer film was characterized using scanning electronic microscopy and surface-enhanced Raman scattering (SERS). The results show that the assembled SERS substrate own excellent Raman enhancement and reproducibility. The synthesized SERS-active substrate was further used to detect methyl-parathion, and the limitation of detection can reach 10{sup −7} M.

DNA methylation and healthy human aging.

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Jones, Meaghan J; Goodman, Sarah J; Kobor, Michael S

2015-12-01

The process of aging results in a host of changes at the cellular and molecular levels, which include senescence, telomere shortening, and changes in gene expression. Epigenetic patterns also change over the lifespan, suggesting that epigenetic changes may constitute an important component of the aging process. The epigenetic mark that has been most highly studied is DNA methylation, the presence of methyl groups at CpG dinucleotides. These dinucleotides are often located near gene promoters and associate with gene expression levels. Early studies indicated that global levels of DNA methylation increase over the first few years of life and then decrease beginning in late adulthood. Recently, with the advent of microarray and next-generation sequencing technologies, increases in variability of DNA methylation with age have been observed, and a number of site-specific patterns have been identified. It has also been shown that certain CpG sites are highly associated with age, to the extent that prediction models using a small number of these sites can accurately predict the chronological age of the donor. Together, these observations point to the existence of two phenomena that both contribute to age-related DNA methylation changes: epigenetic drift and the epigenetic clock. In this review, we focus on healthy human aging throughout the lifetime and discuss the dynamics of DNA methylation as well as how interactions between the genome, environment, and the epigenome influence aging rates. We also discuss the impact of determining 'epigenetic age' for human health and outline some important caveats to existing and future studies. © 2015 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

The Effect of Metabolic and Bariatric Surgery on DNA Methylation Patterns.

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Morcillo, Sonsoles; Macías-González, Manuel; Tinahones, Francisco J

2017-08-30

Metabolic and bariatric surgery (MBS) is considered to be the most effective treatment for obesity. Not only due to the significant weight reduction but also because of the many health benefits associated with it. In the last 5 years, several studies have suggested that epigenetic modifications could be involved in the mechanisms underlying the response to bariatric surgery. In this review, we will compile the different studies (2012-2017) concerning the effect of this surgical procedure on DNA methylation patterns (the most studied epigenetic marker) and its association with metabolic improvement. This is an emerging area, and currently, there are not many studies in the literature. The aim is to show what has been done so far and what the future direction in this emerging area might be. Recent findings have shown how metabolic and bariatric surgery modifies the DNA methylation profile of the specific genes associated with the pathophysiology of the disease. The studies were performed in morbidly obese subjects, mainly in women, with the aim of reducing weight and improving the obesity-associated comorbidities. DNA methylation has been measured both in specific tissue and in peripheral blood samples. In general, studies about site-specific DNA methylation have shown a change in the methylation profile after surgery, whereas the studies analyzing global DNA methylation are not so conclusive. Summing up, metabolic and bariatric surgery can modify the DNA methylation profile of different genes and contributes to the metabolic health benefits that are often seen after metabolic and bariatric surgery. Although there are still many issues to be resolved, the capacity to revert the DNA methylation profile of specific sites opens a window for searching for target markers to treat obesity-related comorbidities.

Seletividade fisiológica de inseticidas a Vespidae predadores de Ascia monuste orseis Insecticide physiological selectivity to Vespidae predators of Ascia monuste orseis

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André Luiz Barreto Crespo

2002-03-01

Full Text Available Este trabalho objetivou estudar a seletividade dos inseticidas carbaril, deltametrina, paratiom metílico, permetrina e triclorfom em relação a Ascia monuste orseis (Godart (Lepidoptera: Pieridae e a seus predadores Brachygastra lecheguana Latreille e Protonectarina sylveirae (Saussure (Hymenoptera: Vespidae. Por meio de curvas de concentração-mortalidade e das concentrações letais para 90% da população (CL90, calcularam-se os índices de seletividade diferencial (ISD90, de toxicidade relativa, e de tolerância relativa (ITRe90. O paratiom metílico e triclorfom apresentaram seletividade em favor de B. lecheguana (ISD90 = 2,83 e 1,75 e P. sylveirae (ISD90 = 2,95 e 3,59 em relação a A. monuste orseis. Deltametrina e permetrina apresentaram seletividade em favor de P. sylveirae (ISD90 = 1,98 e 2,70 em relação a A. monuste orseis, mas não apresentaram seletividade em favor de B. lecheguana (ISD90 = 0,21 e 0,64. B. lecheguana foi menos tolerante a deltametrina, permetrina e triclorfom do que P. sylveirae (ITRe90 = 9,36, 4,23 e 2,05, e mais tolerante ao carbaril (ITRe90 = 0,14. Os predadores apresentaram tolerância semelhante ao paratiom metílico (ITRe90 = 1,04. As curvas de concentração-mortalidade do carbaril, permetrina e triclorfom em ambos os predadores, de deltametrina em B. lecheguana, e de paratiom metílico em P. sylveirae, apresentaram maiores inclinações do que as curvas em A. monuste orseis.This work aimed to study the selectivity of the insecticides carbaryl, deltamethrin, methyl parathion, permethrin and trichlorfon in relation to Ascia monuste orseis (Godart (Lepidoptera: Pieridae and to their predators Brachygastra lecheguana Latreille and Protonectarina sylveirae (Saussure (Hymenoptera: Vespidae. Based on concentration-response curves and lethal concentrations for 90% of the population (LC90, the differential selectivity index (DSI90, relative toxicity index and relative tolerance index (ReTI90 were calculated

Prenatal phthalate exposure and altered patterns of DNA methylation in cord blood.

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Solomon, Olivia; Yousefi, Paul; Huen, Karen; Gunier, Robert B; Escudero-Fung, Maria; Barcellos, Lisa F; Eskenazi, Brenda; Holland, Nina

2017-07-01

Epigenetic changes such as DNA methylation may be a molecular mechanism through which environmental exposures affect health. Phthalates are known endocrine disruptors with ubiquitous exposures in the general population including pregnant women, and they have been linked with a number of adverse health outcomes. We examined the association between in utero phthalate exposure and altered patterns of cord blood DNA methylation in 336 Mexican-American newborns. Concentrations of 11 phthalate metabolites were analyzed in maternal urine samples collected at 13 and 26 weeks gestation as a measure of fetal exposure. DNA methylation was assessed using the Infinium HumanMethylation 450K BeadChip adjusting for cord blood cell composition. To identify differentially methylated regions (DMRs) that may be more informative than individual CpG sites, we used two different approaches, DMRcate and comb-p. Regional assessment by both methods identified 27 distinct DMRs, the majority of which were in relation to multiple phthalate metabolites. Most of the significant DMRs (67%) were observed for later pregnancy (26 weeks gestation). Further, 51% of the significant DMRs were associated with the di-(2-ethylhexyl) phthalate metabolites. Five individual CpG sites were associated with phthalate metabolite concentrations after multiple comparisons adjustment (FDR), all showing hypermethylation. Genes with DMRs were involved in inflammatory response (IRAK4 and ESM1), cancer (BRCA1 and LASP1), endocrine function (CNPY1), and male fertility (IFT140, TESC, and PRDM8). These results on differential DNA methylation in newborns with prenatal phthalate exposure provide new insights and targets to explore mechanism of adverse effects of phthalates on human health. Environ. Mol. Mutagen. 58:398-410, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

DNA methylation analysis reveals distinct methylation signatures in pediatric germ cell tumors

International Nuclear Information System (INIS)

Amatruda, James F; Frazier, A Lindsay; Poynter, Jenny N; Ross, Julie A; Christensen, Brock; Fustino, Nicholas J; Chen, Kenneth S; Hooten, Anthony J; Nelson, Heather; Kuriger, Jacquelyn K; Rakheja, Dinesh

2013-01-01

Aberrant DNA methylation is a prominent feature of many cancers, and may be especially relevant in germ cell tumors (GCTs) due to the extensive epigenetic reprogramming that occurs in the germ line during normal development. We used the Illumina GoldenGate Cancer Methylation Panel to compare DNA methylation in the three main histologic subtypes of pediatric GCTs (germinoma, teratoma and yolk sac tumor (YST); N = 51) and used recursively partitioned mixture models (RPMM) to test associations between methylation pattern and tumor and demographic characteristics. We identified genes and pathways that were differentially methylated using generalized linear models and Ingenuity Pathway Analysis. We also measured global DNA methylation at LINE1 elements and evaluated methylation at selected imprinted loci using pyrosequencing. Methylation patterns differed by tumor histology, with 18/19 YSTs forming a distinct methylation class. Four pathways showed significant enrichment for YSTs, including a human embryonic stem cell pluripotency pathway. We identified 190 CpG loci with significant methylation differences in mature and immature teratomas (q < 0.05), including a number of CpGs in stem cell and pluripotency-related pathways. Both YST and germinoma showed significantly lower methylation at LINE1 elements compared with normal adjacent tissue while there was no difference between teratoma (mature and immature) and normal tissue. DNA methylation at imprinted loci differed significantly by tumor histology and location. Understanding methylation patterns may identify the developmental stage at which the GCT arose and the at-risk period when environmental exposures could be most harmful. Further, identification of relevant genetic pathways could lead to the development of new targets for therapy

Modeling of the oxidation of methyl esters—Validation for methyl hexanoate, methyl heptanoate, and methyl decanoate in a jet-stirred reactor

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Glaude, Pierre Alexandre; Herbinet, Olivier; Bax, Sarah; Biet, Joffrey; Warth, Valérie; Battin-Leclerc, Frédérique

2013-01-01

The modeling of the oxidation of methyl esters was investigated and the specific chemistry, which is due to the presence of the ester group in this class of molecules, is described. New reactions and rate parameters were defined and included in the software EXGAS for the automatic generation of kinetic mechanisms. Models generated with EXGAS were successfully validated against data from the literature (oxidation of methyl hexanoate and methyl heptanoate in a jet-stirred reactor) and a new set of experimental results for methyl decanoate. The oxidation of this last species was investigated in a jet-stirred reactor at temperatures from 500 to 1100 K, including the negative temperature coefficient region, under stoichiometric conditions, at a pressure of 1.06 bar and for a residence time of 1.5 s: more than 30 reaction products, including olefins, unsaturated esters, and cyclic ethers, were quantified and successfully simulated. Flow rate analysis showed that reactions pathways for the oxidation of methyl esters in the low-temperature range are similar to that of alkanes. PMID:23710076

Modeling of the oxidation of methyl esters-Validation for methyl hexanoate, methyl heptanoate, and methyl decanoate in a jet-stirred reactor.

Science.gov (United States)

Glaude, Pierre Alexandre; Herbinet, Olivier; Bax, Sarah; Biet, Joffrey; Warth, Valérie; Battin-Leclerc, Frédérique

2010-11-01

The modeling of the oxidation of methyl esters was investigated and the specific chemistry, which is due to the presence of the ester group in this class of molecules, is described. New reactions and rate parameters were defined and included in the software EXGAS for the automatic generation of kinetic mechanisms. Models generated with EXGAS were successfully validated against data from the literature (oxidation of methyl hexanoate and methyl heptanoate in a jet-stirred reactor) and a new set of experimental results for methyl decanoate. The oxidation of this last species was investigated in a jet-stirred reactor at temperatures from 500 to 1100 K, including the negative temperature coefficient region, under stoichiometric conditions, at a pressure of 1.06 bar and for a residence time of 1.5 s: more than 30 reaction products, including olefins, unsaturated esters, and cyclic ethers, were quantified and successfully simulated. Flow rate analysis showed that reactions pathways for the oxidation of methyl esters in the low-temperature range are similar to that of alkanes.

A review on environmental factors regulating arsenic methylation in humans

International Nuclear Information System (INIS)

Tseng, C.-H.

2009-01-01

Subjects exposed to arsenic show significant inter-individual variation in urinary patterns of arsenic metabolites but insignificant day-to-day intra-individual variation. The inter-individual variation in arsenic methylation can be partly responsible for the variation in susceptibility to arsenic toxicity. Wide inter-ethnic variation and family correlation in urinary arsenic profile suggest a genetic effect on arsenic metabolism. In this paper the environmental factors affecting arsenic metabolism are reviewed. Methylation capacity might reduce with increasing dosage of arsenic exposure. Furthermore, women, especially at pregnancy, have better methylation capacity than their men counterparts, probably due to the effect of estrogen. Children might have better methylation capacity than adults and age shows inconsistent relevance in adults. Smoking and alcohol consumption might be associated with a poorer methylation capacity. Nutritional status is important in the methylation capacity and folate may facilitate the methylation and excretion of arsenic. Besides, general health conditions and medications might influence the arsenic methylation capacity; and technical problems can cause biased estimates. The consumption of seafood, seaweed, rice and other food with high arsenic contents and the extent of cooking and arsenic-containing water used in food preparation may also interfere with the presentation of the urinary arsenic profile. Future studies are necessary to clarify the effects of the various arsenic metabolites including the trivalent methylated forms on the development of arsenic-induced human diseases with the consideration of the effects of confounding factors and the interactions with other effect modifiers

Oxidative stress and repetitive element methylation changes in artisanal gold miners occupationally exposed to mercury

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Diana M. Narváez

2017-09-01

Full Text Available Mercury (Hg exposure is a public health concern due to its persistence in the environment and its high toxicity. Such toxicity has been associated with the generation of oxidative stress in occupationally exposed subjects, such as artisanal gold miners. In this study, we characterize occupational exposure to Hg by measuring blood, urine and hair levels, and investigate oxidative stress and DNA methylation associated with gold mining. To do this, samples from 53 miners and 36 controls were assessed. We show higher levels of oxidative stress marker 8-OHdG in the miners. Differences in LINE1 and Alu(Yb8 DNA methylation between gold miners and control group are present in peripheral blood leukocytes. LINE1 methylation is positively correlated with 8-OHdG levels, while XRCC1 and LINE1 methylation are positively correlated with Hg levels. These results suggest an effect of Hg on oxidative stress and DNA methylation in gold miners that may have an impact on miners’ health.

Quantitative structure activity relationship and risk analysis of some pesticides in the goat milk

OpenAIRE

Muhammad, Faqir; Awais, Mian Muhammad; Akhtar, Masood; Anwar, Muhammad Irfan

2013-01-01

The detection and quantification of different pesticides in the goat milk samples collected from different localities of Faisalabad, Pakistan was performed by HPLC using solid phase microextraction. The analysis showed that about 50% milk samples were contaminated with pesticides. The mean+/-SEM levels (ppm) of cyhalothrin, endosulfan, chlorpyrifos and cypermethrin were 0.34+/-0.007, 0.063+/-0.002, 0.034+/-0.002 and 0.092+/-0.002, respectively; whereas, methyl parathion was not detected in an...

Monitoring of organochlorine and organophosphorus pesticide residues in water during different seasons of Tighra reservoir Gwalior, Madhya Pradesh, India.

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Mamta; Rao, R J; Wani, Khursheed Ahmad

2015-11-01

Analysis of pesticides during different seasons for pesticidal contamination in water samples of Tighra reservoir was carried out on gas chromatograph-electron capture detector with capillary columns following multiresidual analytical technique. Organochlorine pesticides, viz., hexachlorobenzene (HCB), alpha-benzene hexachloride (BHC), beta-BHC, γ-BHC, heptachlor, aldrin, alpha-endosulfan, beta-endosulfan, p,p-DDE, dieldrin, o,p-dichlorodiphenyldichloroethane (DDD), p,p-DDD, p,p-dichlorodiphenyltrichloroethane (DDT), and endrin, and organophosphorus pesticides, viz., choloropyrifos, methyl parathion, diazion, dicholorovos, ethion, malathion, and parathion, were detected in water samples during different seasons. However, the pesticide concentration varied during different seasons at different sites. The prominent reason of contamination is the use of pesticides (both organochlorine and organophosphorus) in the agricultural fields near Tighra reservoir. On the basis of our observations, more extensive monitoring studies need to be carried out, covering all wetlands of Madhya Pradesh to enforce the policies for the restricted application of pesticides in agricultural fields adjacent to wetlands.

Arsenic (+3 oxidation state) methyltransferase and the inorganic arsenic methylation phenotype

International Nuclear Information System (INIS)

Li Jiaxin; Waters, Stephen B.; Drobna, Zuzana; Devesa, Vicenta; Styblo, Miroslav; Thomas, David J.

2005-01-01

Inorganic arsenic is enzymatically methylated; hence, its ingestion results in exposure to the parent compound and various methylated arsenicals. Both experimental and epidemiological evidences suggest that some of the adverse health effects associated with chronic exposure to inorganic arsenic may be mediated by these methylated metabolites. If i As methylation is an activation process, then the phenotype for inorganic arsenic methylation may determine risk associated with exposure to this metalloid. We examined inorganic arsenic methylation phenotypes and arsenic (+3 oxidation state) methyltransferase genotypes in four species: three that methylate inorganic arsenic (human (Homo sapiens), rat (Rattus norwegicus), and mouse (Mus musculus)) and one that does not methylate inorganic arsenic (chimpanzee, Pan troglodytes). The predicted protein products from arsenic (+3 oxidation state) methyltransferase are similar in size for rat (369 amino acid residues), mouse (376 residues), and human (375 residues). By comparison, a 275-nucleotide deletion beginning at nucleotide 612 in the chimpanzee gene sequence causes a frameshift that leads to a nonsense mutation for a premature stop codon after amino acid 205. The null phenotype for inorganic arsenic methylation in the chimpanzee is likely due to the deletion in the gene for arsenic (+3 oxidation state) methyltransferase that yields an inactive truncated protein. This lineage-specific loss of function caused by the deletion event must have occurred in the Pan lineage after Homo-Pan divergence about 5 million years ago

Using Sulfate-Amended Sediment Slurry Batch Reactors to Evaluate Mercury Methylation

International Nuclear Information System (INIS)

Harmon, S.M.

2003-01-01

In the methylated form, mercury represents a concern to public health primarily through the consumption of contaminated fish tissue. Research conducted on the methylation of mercury strongly suggests the process is microbial in nature and facilitated principally by sulfate-reducing bacteria. This study addressed the potential for mercury methylation by varying sulfate treatments and wetland-based soil in microbial slurry reactors with available inorganic mercury. Under anoxic laboratory conditions conducive to growth of naturally occurring sulfate-reducing bacteria in the soil, it was possible to evaluate how various sulfate additions influenced the methylation of inorganic mercury added to overlying water. Treatments included sulfate amendments ranging FR-om 25 to 500 mg/L (0.26 to 5.2 mM) above the soil's natural sulfate level. This study also provided an assessment of mercury methylation relative to sulfate-reducing bacterial population growth and subsequent sulfide production. Mercury methylation in sulfate treatments did not exceed that of the non-amended control during a 35-day incubation. However, increases in methylmercury concentration were linked to bacterial growth and sulfate reduction. A time lag in methylation in the highest treatment correlated with an equivalent lag in bacterial growth

Altered placental DNA methylation patterns associated with maternal smoking: current perspectives

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Maccani JZ

2015-05-01

Full Text Available Jennifer ZJ Maccani, Matthew A Maccani Penn State Tobacco Center of Regulatory Science, College of Medicine, Department of Public Health Sciences, Hershey, PA, USA Abstract: The developmental origins of health and disease hypothesis states that adverse early life exposures can have lasting, detrimental effects on lifelong health. Exposure to maternal cigarette smoking during pregnancy is associated with morbidity and mortality in offspring, including increased risks for miscarriage, stillbirth, low birth weight, preterm birth, asthma, obesity, altered neurobehavior, and other conditions. Maternal cigarette smoking during pregnancy interferes with placental growth and functioning, and it has been proposed that this may occur through the disruption of normal and necessary placental epigenetic patterns. Epigenome-wide association studies have identified a number of differentially methylated placental genes that are associated with maternal smoking during pregnancy, including RUNX3, PURA, GTF2H2, GCA, GPR135, and HKR1. The placental methylation status of RUNX3 and NR3C1 has also been linked to adverse infant outcomes, including preterm birth and low birth weight, respectively. Candidate gene analyses have also found maternal smoking-associated placental methylation differences in the NR3C1, CYP1A1, HTR2A, and HSD11B2 genes, as well as in the repetitive elements LINE-1 and AluYb8. The differential methylation patterns of several genes have been confirmed to also exhibit altered gene expression patterns, including CYP1A1, CYP19A1, NR3C1, and HTR2A. Placental methylation patterns associated with maternal smoking during pregnancy may be largely gene-specific and tissue-specific and, to a lesser degree, involve global changes. It is important for future research to investigate the mechanistic roles that these differentially methylated genes may play in mediating the association between maternal smoking during pregnancy and disease in later life, as well

Automated sequence- and stereo-specific assignment of methyl-labeled proteins by paramagnetic relaxation and methyl-methyl nuclear overhauser enhancement spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Venditti, Vincenzo; Fawzi, Nicolas L.; Clore, G. Marius, E-mail: mariusc@mail.nih.gov [National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Laboratory of Chemical Physics (United States)

2011-11-15

Methyl-transverse relaxation optimized spectroscopy is rapidly becoming the preferred NMR technique for probing structure and dynamics of very large proteins up to {approx}1 MDa in molecular size. Data interpretation, however, necessitates assignment of methyl groups which still presents a very challenging and time-consuming process. Here we demonstrate that, in combination with a known 3D structure, paramagnetic relaxation enhancement (PRE), induced by nitroxide spin-labels incorporated at only a few surface-exposed engineered cysteines, provides fast, straightforward and robust access to methyl group resonance assignments, including stereoassignments for the methyl groups of leucine and valine. Neither prior assignments, including backbone assignments, for the protein, nor experiments that transfer magnetization between methyl groups and the protein backbone, are required. PRE-derived assignments are refined by 4D methyl-methyl nuclear Overhauser enhancement data, eliminating ambiguities and errors that may arise due to the high sensitivity of PREs to the potential presence of sparsely-populated transient states.

Metformin regulates global DNA methylation via mitochondrial one-carbon metabolism.

Science.gov (United States)

Cuyàs, E; Fernández-Arroyo, S; Verdura, S; García, R Á-F; Stursa, J; Werner, L; Blanco-González, E; Montes-Bayón, M; Joven, J; Viollet, B; Neuzil, J; Menendez, J A

2018-02-15

The anti-diabetic biguanide metformin may exert health-promoting effects via metabolic regulation of the epigenome. Here we show that metformin promotes global DNA methylation in non-cancerous, cancer-prone and metastatic cancer cells by decreasing S-adenosylhomocysteine (SAH), a strong feedback inhibitor of S-adenosylmethionine (SAM)-dependent DNA methyltransferases, while promoting the accumulation of SAM, the universal methyl donor for cellular methylation. Using metformin and a mitochondria/complex I (mCI)-targeted analog of metformin (norMitoMet) in experimental pairs of wild-type and AMP-activated protein kinase (AMPK)-, serine hydroxymethyltransferase 2 (SHMT2)- and mCI-null cells, we provide evidence that metformin increases the SAM:SAH ratio-related methylation capacity by targeting the coupling between serine mitochondrial one-carbon flux and CI activity. By increasing the contribution of one-carbon units to the SAM from folate stores while decreasing SAH in response to AMPK-sensed energetic crisis, metformin can operate as a metabolo-epigenetic regulator capable of reprogramming one of the key conduits linking cellular metabolism to the DNA methylation machinery.

Methylation diet and methyl group genetics in risk for adenomatous polyp occurrence

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Mark Lucock

2015-06-01

Conclusion: A methylation diet influences methyl group synthesis in the regulation of blood homocysteine level, and is modulated by genetic interactions. Methylation-related nutrients also interact with key genes to modify risk of AP, a precursor of colorectal cancer. Independent of diet, two methylation-related genes (A2756G-MS and A66G-MSR were directly associated with AP occurrence.

Reactions of guanine with methyl chloride and methyl bromide: O6-methylation versus charge transfer complex formation

Science.gov (United States)

Shukla, P. K.; Mishra, P. C.; Suhai, S.

Density functional theory (DFT) at the B3LYP/6-31+G* and B3LYP/AUG-cc-pVDZ levels was employed to study O6-methylation of guanine due to its reactions with methyl chloride and methyl bromide and to obtain explanation as to why the methyl halides cause genotoxicity and possess mutagenic and carcinogenic properties. Geometries of the various isolated species involved in the reactions, reactant complexes (RCs), and product complexes (PCs) were optimized in gas phase. Transition states connecting the reactant complexes with the product complexes were also optimized in gas phase at the same levels of theory. The reactant complexes, product complexes, and transition states were solvated in aqueous media using the polarizable continuum model (PCM) of the self-consistent reaction field theory. Zero-point energy (ZPE) correction to total energy and the corresponding thermal energy correction to enthalpy were made in each case. The reactant complexes of the keto form of guanine with methyl chloride and methyl bromide in water are appreciably more stable than the corresponding complexes involving the enol form of guanine. The nature of binding in the product complexes was found to be of the charge transfer type (O6mG+ · X-, X dbond Cl, Br). Binding of HCl, HBr, and H2O molecules to the PCs obtained with the keto form of guanine did not alter the positions of the halide anions in the PCs, and the charge transfer character of the PCs was also not modified due to this binding. Further, the complexes obtained due to the binding of HCl, HBr, and H2O molecules to the PCs had greater stability than the isolated PCs. The reaction barriers involved in the formation of PCs were found to be quite high (?50 kcal/mol). Mechanisms of genotoxicity, mutagenesis and carcinogenesis caused by the methyl halides appear to involve charge transfer-type complex formation. Thus the mechanisms of these processes involving the methyl halides appear to be quite different from those that involve the

Trans-methylation reactions in plants: focus on the activated methyl cycle.

Science.gov (United States)

Rahikainen, Moona; Alegre, Sara; Trotta, Andrea; Pascual, Jesús; Kangasjärvi, Saijaliisa

2018-02-01

Trans-methylation reactions are vital in basic metabolism, epigenetic regulation, RNA metabolism, and posttranslational control of protein function and therefore fundamental in determining the physiological processes in all living organisms. The plant kingdom is additionally characterized by the production of secondary metabolites that undergo specific hydroxylation, oxidation and methylation reactions to obtain a wide array of different chemical structures. Increasing research efforts have started to reveal the enzymatic pathways underlying the biosynthesis of complex metabolites in plants. Further engineering of these enzymatic machineries offers significant possibilities in the development of bio-based technologies, but necessitates deep understanding of their potential metabolic and regulatory interactions. Trans-methylation reactions are tightly coupled with the so-called activated methyl cycle (AMC), an essential metabolic circuit that maintains the trans-methylation capacity in all living cells. Tight regulation of the AMC is crucial in ensuring accurate trans-methylation reactions in different subcellular compartments, cell types, developmental stages and environmental conditions. This review addresses the organization and posttranslational regulation of the AMC and elaborates its critical role in determining metabolic regulation through modulation of methyl utilization in stress-exposed plants. © 2017 Scandinavian Plant Physiology Society.

Exposure assessment of traditional and IPM farmers on using pesticides: A case study at Bang Rieng Sub District, Khuan Nieng District, Songkhla Province

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Viris Jirachaiyabhas

2004-02-01

Full Text Available A questionnaire was developed to quantitatively evaluate the exposure to pesticides and to gauge the concentration of organophosphate pesticides such as chlorpyrifos and methyl-parathion while the farmers of Bang Rieng were spraying these pesticides. The results were applied to the exposure assessment and to compare the quantity of exposure to these pesticides between 33 traditional and 40 integrated pest management (IPM farmers of Bang Rieng. There was a significant difference in the level of exposure between the traditional farmers, who had the average pesticide exposure scores of 58.30 points and the IPM farmers, whose average scores were 53.50 points, (p < 0.015. Concentrations of organophosphate pesticides chlorpyrifos and methyl-parathion were measured. Thirty-three air samples were collected by personal sampling during the period of pesticide spraying. Traditional farmers were exposed to higher levels of the pesticide(s with a mean concentration of 0.1865 mg/m compared to the IPM farmers who were exposed to a mean pesticide concentration of 0.037 mg/m3. It was estimated that the farmers of Bang Rieng would be exposed to 186-19,616.6 mg of the organophosphatepesticide(s via inhalation throughout their lifetime (65 years. Moreover, according to the exposure assessment, the traditional farmers exposed to a greater amount of the pesticide(s via inhalation compared to the IPM farmers.

Embryo yolk sac membrane kynurenine formamidase of l-tryptophan to NAD+ pathway as a primary target for organophosphorus insecticides (OPI) in OPI-induced NAD-associated avian teratogenesis.

Science.gov (United States)

Seifert, Josef

2017-10-01

The objective of this study was to provide in ovo evidence for the proposed role of kynurenine formamidase of l-tryptophan to NAD + pathway in embryo yolk sac membranes as a primary target for organophosphorus insecticide (OPI) teratogens in OPI-induced NAD-associated avian teratogenesis. Slices prepared from yolk sac membranes or embryo livers of chicken eggs treated with the OPI dicrotophos and/or methyl parathion were incubated with l-tryptophan. Yolk sac membrane slices metabolized l-tryptophan in the pathway to NAD + before that function was established in livers. OPI interfered in ovo with the second step of l-tryptophan to NAD + biosynthesis by inhibiting kynurenine formamidase. Its inhibition due to the teratogen dicrotophos occurred in yolk sac membranes during the period of embryo highest susceptibility to OPI teratogens in contrast to delayed and lower inhibition caused by the nonteratogen methyl parathion. Both OPI affected liver kynurenine formamidase in a similar manner. The onsets of liver enzyme inhibition, however, were delayed by about two days and occurred at the time of the reduced embryo susceptibility to teratogens. The early disruption of l-tryptophan metabolism and higher inhibition of kynurenine formamidase in yolk sac membranes may be the factors that determine action of OPI as teratogens in chicken embryos. Copyright © 2017 Elsevier Ltd. All rights reserved.

Agrochemical loading in drains and rivers and its connection with pollution in coastal lagoons of the Mexican Pacific.

Science.gov (United States)

Arellano-Aguilar, Omar; Betancourt-Lozano, Miguel; Aguilar-Zárate, Gabriela; Ponce de Leon-Hill, Claudia

2017-06-01

The state of Sinaloa in Mexico is an industrialized agricultural region with a documented pesticide usage of 700 t year -1 ; which at least 17 of the pesticides are classified as moderately to highly toxic. Pollutants in the water column of rivers and drains are of great concern because the water flows into coastal lagoons and nearshore waters and thereby affects aquatic organisms. This study was done in four municipalities in the state of Sinaloa that produce food intensively. To investigate the link between pollution in the lagoons and their proximity to agricultural sites, water was sampled in three coastal lagoons and in the rivers and drains that flow into them. Seawater from the Gulf of California, 10 km from the coast, was also analyzed. Concentrations of nutrients, organochlorines, and organophosphorus pesticides were determined. Nutrient determination showed an unhealthy environment with N/P ratios of pollution of the coastal lagoon of Pabellones could be traced mainly to the drains from the agricultural sites. Accumulation of OC pesticides was also observed in the Gulf of California. Tests for 22 organophosphates revealed only five (diazinon, disulfoton, methyl parathion, chlorpyrifos, and mevinphos); diazinon was detected at all the sites, although methyl parathion was present at some sites at concentrations one order of magnitude higher than diazinon.

Development, validation and application of a SDME/GC-FID methodology for the multiresidue determination of organophosphate and pyrethroid pesticides in water.

Science.gov (United States)

Pinheiro, Anselmo de Souza; de Andrade, Jailson B

2009-10-15

A single-drop microextraction (SDME) procedure was developed for the analysis of organophosphorus and pyrethroid pesticides in water by gas chromatography (GC) with flame ionization detection (GC-FID). The significant parameters that affect SDME performance, such as the selection of microextraction solvent, solvent volume, extraction time, and stirring rate, were studied and optimized using a tool screening factorial design. The limits of detection (LODs) in water for the four investigated compounds were between 0.3 and 3.0 microgL(-1), with relative standard deviations ranging from 7.7 to 18.8%. Linear response data were obtained in the concentration range of 0.9-6.0 microg L(-1) (lambda-cyhalothrin), 3.0-60.0 microg L(-1) (methyl parathion), 9.0-60.0 microg L(-1) (ethion), and 9.0-30.0 microg L(-1) (permethrin), with correlation coefficients ranging from 0.9337 to 0.9977. The relative recoveries for the spiked water ranged from 73.0 to 104%. Environmental water samples (n=26) were successfully analyzed using the proposed method and methyl parathion presented concentration up to 2.74 microg L(-1). The SDME method, coupled with GC-FID analysis, provided good precision, accuracy, and reproducibility over a wide linear range. Other highlights of the method include its ease of use and its requirement of only small volumes of both organic solvent and sample.

21 CFR 177.2000 - Vinylidene chloride/methyl acrylate/methyl methacrylate polymers.

Science.gov (United States)

2010-04-01

... methacrylate polymers. 177.2000 Section 177.2000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF...: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.2000 Vinylidene chloride/methyl acrylate/methyl methacrylate polymers. The vinylidene chloride/methyl acrylate...

Methyl-Donor and Cofactor Nutrient Intakes in the First 2–3 Years and Global DNA Methylation at Age 4: A Prospective Cohort Study

Directory of Open Access Journals (Sweden)

Rachael M. Taylor

2018-02-01

Full Text Available Background: During the early postnatal period, the impact of nutrition on DNA methylation has not been well studied in humans. The aim was to quantify the relationship between one-carbon metabolism nutrient intake during the first three years of life and global DNA methylation levels at four years. Design: Childhood dietary intake was assessed using infant feeding questionnaires, food frequency questionnaires, 4-day weighed food records and 24-h food records. The dietary records were used to estimate the intake of methionine, folate, vitamins B2, B6 and B12 and choline. The accumulative nutrient intake specific rank from three months to three years of age was used for analysis. Global DNA methylation (%5-methyl cytosines (%5-mC was measured in buccal cells at four years of age, using an enzyme-linked immunosorbent assay (ELISA commercial kit. Linear regression models were used to quantify the statistical relationships. Results: Data were collected from 73 children recruited from the Women and their Children’s Health (WATCH study. No association was found between one-carbon metabolism nutrient intake and global DNA methylation levels (P > 0.05. Global DNA methylation levels in males were significantly higher than in females (median %5-mC: 1.82 vs. 1.03, males and females respectively, (P < 0.05. Conclusion: No association was found between the intake of one-carbon metabolism nutrients during the early postnatal period and global DNA methylation levels at age four years. Higher global DNA methylation levels in males warrants further investigation.

Methyl-Donor and Cofactor Nutrient Intakes in the First 2–3 Years and Global DNA Methylation at Age 4: A Prospective Cohort Study

Science.gov (United States)

Taylor, Rachael M.; Smith, Roger; Collins, Clare E.; Mossman, David; Wong-Brown, Michelle W.; Chan, Eng-Cheng; Evans, Tiffany-Jane; Attia, John R.; Smith, Tenele; Butler, Trent

2018-01-01

Background: During the early postnatal period, the impact of nutrition on DNA methylation has not been well studied in humans. The aim was to quantify the relationship between one-carbon metabolism nutrient intake during the first three years of life and global DNA methylation levels at four years. Design: Childhood dietary intake was assessed using infant feeding questionnaires, food frequency questionnaires, 4-day weighed food records and 24-h food records. The dietary records were used to estimate the intake of methionine, folate, vitamins B2, B6 and B12 and choline. The accumulative nutrient intake specific rank from three months to three years of age was used for analysis. Global DNA methylation (%5-methyl cytosines (%5-mC)) was measured in buccal cells at four years of age, using an enzyme-linked immunosorbent assay (ELISA) commercial kit. Linear regression models were used to quantify the statistical relationships. Results: Data were collected from 73 children recruited from the Women and their Children’s Health (WATCH) study. No association was found between one-carbon metabolism nutrient intake and global DNA methylation levels (P 0.05). Global DNA methylation levels in males were significantly higher than in females (median %5-mC: 1.82 vs. 1.03, males and females respectively, (P 0.05)). Conclusion: No association was found between the intake of one-carbon metabolism nutrients during the early postnatal period and global DNA methylation levels at age four years. Higher global DNA methylation levels in males warrants further investigation. PMID:29495543

Whole-genome methylation caller designed for methyl- DNA ...

African Journals Online (AJOL)

etchie

2013-02-20

Feb 20, 2013 ... Key words: Methyl-DNA immunoprecipitation, next-generation sequencing, Hidden ... its response to environmental cues. .... have a great potential to become the most cost-effective ... hg18 reference genome (set to 0 if not present in retrieved reads). ..... DNA methylation patterns and epigenetic memory.

DNA Methylation and Methylation Polymorphism in Genetically Stable In vitro Regenerates of Jatropha curcas L. Using Methylation-Sensitive AFLP Markers.

Science.gov (United States)

Rathore, Mangal S; Jha, Bhavanath

2016-03-01

The present investigation aimed to evaluate the degree and pattern of DNA methylation using methylation-sensitive AFLP (MS-AFLP) markers in genetically stable in vitro regenerates of Jatropha curcas L.. The genetically stable in vitro regenerates were raised through direct organogenesis via enhanced axillary shoot bud proliferation (Protocol-1) and in vitro-derived leaf regeneration (Protocol-2). Ten selective combinations of MS-AFLP primers produced 462 and 477 MS-AFLP bands in Protocol-1 (P-1) and Protocol-2 (P-2) regenerates, respectively. In P-1 regenerates, 15.8-31.17 % DNA was found methylated with an average of 25.24 %. In P-2 regenerates, 15.93-32.7 % DNA was found methylated with an average of 24.11 %. Using MS-AFLP in P-1 and P-2 regenerates, 11.52-25.53 % and 13.33-25.47 % polymorphism in methylated DNA was reported, respectively. Compared to the mother plant, P-1 regenerates showed hyper-methylation while P-2 showed hypo-methylation. The results clearly indicated alternation in degree and pattern of DNA methylation; hence, epigenetic instability in the genetically stable in vitro regenerates of J. curcas, developed so far using two different regeneration systems and explants of two different origins. The homologous nucleotide fragments in genomes of P-1 and P-2 regenerates showing methylation re-patterning might be involved in immediate adaptive responses and developmental processes through differential regulation of transcriptome under in vitro conditions.

Analysis of DNA methylation in Arabidopsis thaliana based on methylation-sensitive AFLP markers.

Science.gov (United States)

Cervera, M T; Ruiz-García, L; Martínez-Zapater, J M

2002-12-01

AFLP analysis using restriction enzyme isoschizomers that differ in their sensitivity to methylation of their recognition sites has been used to analyse the methylation state of anonymous CCGG sequences in Arabidopsis thaliana. The technique was modified to improve the quality of fingerprints and to visualise larger numbers of scorable fragments. Sequencing of amplified fragments indicated that detection was generally associated with non-methylation of the cytosine to which the isoschizomer is sensitive. Comparison of EcoRI/ HpaII and EcoRI/ MspI patterns in different ecotypes revealed that 35-43% of CCGG sites were differentially digested by the isoschizomers. Interestingly, the pattern of digestion among different plants belonging to the same ecotype is highly conserved, with the rate of intra-ecotype methylation-sensitive polymorphisms being less than 1%. However, pairwise comparisons of methylation patterns between samples belonging to different ecotypes revealed differences in up to 34% of the methylation-sensitive polymorphisms. The lack of correlation between inter-ecotype similarity matrices based on methylation-insensitive or methylation-sensitive polymorphisms suggests that whatever the mechanisms regulating methylation may be, they are not related to nucleotide sequence variation.

The global DNA methylation surrogate LINE-1 methylation is correlated with MGMT promoter methylation and is a better prognostic factor for glioma.

Directory of Open Access Journals (Sweden)

Fumiharu Ohka

Full Text Available Gliomas are the most frequently occurring primary brain tumor in the central nervous system of adults. Glioblastoma multiformes (GBMs, WHO grade 4 have a dismal prognosis despite the use of the alkylating agent, temozolomide (TMZ, and even low grade gliomas (LGGs, WHO grade 2 eventually transform to malignant secondary GBMs. Although GBM patients benefit from promoter hypermethylation of the O(6-methylguanine-DNA methyltransferase (MGMT that is the main determinant of resistance to TMZ, recent studies suggested that MGMT promoter methylation is of prognostic as well as predictive significance for the efficacy of TMZ. Glioma-CpG island methylator phenotype (G-CIMP in the global genome was shown to be a significant predictor of improved survival in patients with GBM. Collectively, we hypothesized that MGMT promoter methylation might reflect global DNA methylation. Additionally in LGGs, the significance of MGMT promoter methylation is still undetermined. In the current study, we aimed to determine the correlation between clinical, genetic, and epigenetic profiles including LINE-1 and different cancer-related genes and the clinical outcome in newly diagnosed 57 LGG and 54 GBM patients. Here, we demonstrated that (1 IDH1/2 mutation is closely correlated with MGMT promoter methylation and 1p/19q codeletion in LGGs, (2 LINE-1 methylation levels in primary and secondary GBMs are lower than those in LGGs and normal brain tissues, (3 LINE-1 methylation is proportional to MGMT promoter methylation in gliomas, and (4 higher LINE-1 methylation is a favorable prognostic factor in primary GBMs, even compared to MGMT promoter methylation. As a global DNA methylation marker, LINE-1 may be a promising marker in gliomas.

Recognition of methylated DNA through methyl-CpG binding domain proteins

DEFF Research Database (Denmark)

Zou, Xueqing; Ma, Wen; Solov'yov, Ilia

2012-01-01

DNA methylation is a key regulatory control route in epigenetics, involving gene silencing and chromosome inactivation. It has been recognized that methyl-CpG binding domain (MBD) proteins play an important role in interpreting the genetic information encoded by methylated DNA (mDNA). Although...... the function of MBD proteins has attracted considerable attention and is well characterized, the mechanism underlying mDNA recognition by MBD proteins is still poorly understood. In this article, we demonstrate that the methyl-CpG dinucleotides are recognized at the MBD-mDNA interface by two MBD arginines...

A genome-wide methylation study on obesity Differential variability and differential methylation

NARCIS (Netherlands)

Xu, Xiaojing; Su, Shaoyong; Barnes, Vernon A.; De Miguel, Carmen; Pollock, Jennifer; Ownby, Dennis; Shi, Huidong; Zhu, Haidong; Snieder, Harold; Wang, Xiaoling

2013-01-01

Besides differential methylation, DNA methylation variation has recently been proposed and demonstrated to be a potential contributing factor to cancer risk. Here we aim to examine whether differential variability in methylation is also an important feature of obesity, a typical non-malignant common

Neural Tube Defects, Folic Acid and Methylation

Science.gov (United States)

Imbard, Apolline; Benoist, Jean-François; Blom, Henk J.

2013-01-01

Neural tube defects (NTDs) are common complex congenital malformations resulting from failure of the neural tube closure during embryogenesis. It is established that folic acid supplementation decreases the prevalence of NTDs, which has led to national public health policies regarding folic acid. To date, animal studies have not provided sufficient information to establish the metabolic and/or genomic mechanism(s) underlying human folic acid responsiveness in NTDs. However, several lines of evidence suggest that not only folates but also choline, B12 and methylation metabolisms are involved in NTDs. Decreased B12 vitamin and increased total choline or homocysteine in maternal blood have been shown to be associated with increased NTDs risk. Several polymorphisms of genes involved in these pathways have also been implicated in risk of development of NTDs. This raises the question whether supplementation with B12 vitamin, betaine or other methylation donors in addition to folic acid periconceptional supplementation will further reduce NTD risk. The objective of this article is to review the role of methylation metabolism in the onset of neural tube defects. PMID:24048206

Seletividade de inseticidas a Doru luteipes (Scudder, 1876 (Dermaptera: Forficulidae e Cotesia sp. (Hymenoptera: Braconidae inimigos naturais de Ascia monuste orseis (Godart, 1818 (Lepdoptera: Pieridae Selectivity of insecticides to Doru luteipes (Scudder, 1876 (Dermaptera: Forficulidae and Cotesia sp. (Hymenoptera: Braconidae natural enemies of Ascia monuste orseis (Godart, 1818 (Lepdoptera: Pieridae

Directory of Open Access Journals (Sweden)

Marcelo Coutitnho Picanço

2003-04-01

Full Text Available Este trabalho objetivou estudar a seletividade dos inseticidas carbaril, deltametrina, paratiom metílico, permetrina e triclorfom em favor do predador Doru luteipes (Scudder (Dermaptera: Forficulidae e do parasitóide Cotesia sp. (Hymenoptera: Braconidae, em relação ao controle do curuquerê Ascia monuste orseis (Godart (Lepidoptera: Pieridae. Foram determinadas as CL90 para A. monuste orseis e estas foram utilizadas como doses discriminatórias para se avaliar o grau de seletividade dos inseticidas. Deltametrina e permetrina foram altamente seletivos em favor de D. luteipes. Deltametrina foi medianamente seletiva em favor de Cotesia sp. e a permetrina não apresentou seletividade em favor deste parasitóide. Triclorfom foi altamente seletivo em favor de ninfas de quarto estádio e adultos de D. luteipes e mediamente seletivo em favor de Cotesia sp. e de ninfas de primeiro estádio do predador. Carbaril foi medianamente seletivo em favor de Cotesia sp. mas não apresentou seletividade em favor de D. luteipes. Paratiom metílico não foi seletivo em favor de Cotesia sp. e D. luteipes. Adultos de D. luteipes foram menos sensíveis a deltametrina, permetrina e triclorfom do que adultos de Cotesia sp., sendo que o inverso ocorreu com o carbaril. Esses inimigos naturais apresentaram alta sensibilidade ao paratiom metílico. Ninfas de quarto estádio e adultos de D. luteipes foram mais sensíveis ao paratiom metílico e triclorfom que ninfas de primeiro estádio. Ninfas e adultos de D. luteipes apresentaram semelhante sensibilidade ao carbaril, deltametrina e permetrina.This work aimed to study the selectivity of the insecticides carbaryl, deltamethrin, methyl parathion, permethrin and trichlorfon in favor of the predator Doru luteipes (Scudder (Dermaptera: Forficulidae and of the parasitoid Cotesia sp. (Hymenoptera; Braconidae in relation to the control of the kale leafworm Ascia monuste orseis (Godart (Lepidoptera: Pieridae. LC90 were determined

Protein methylation in pea chloroplasts

International Nuclear Information System (INIS)

Niemi, K.J.; Adler, J.; Selman, B.R.

1990-01-01

The methylation of chloroplast proteins has been investigated by incubating intact pea (Pisum sativum) chloroplasts with [ 3 H-methyl]-S-adenosylmethionine. Incubation in the light increases the amount of methylation in both the thylakoid and stromal fractions. Numerous thylakoid proteins serve as substrates for the methyltransfer reactions. Three of these thylakoid proteins are methylated to a significantly greater extent in the light than in the dark. The primary stromal polypeptide methylated is the large subunit of ribulose bisphosphate carboxylase/oxygenase. One other stromal polypeptide is also methylated much more in the light than in the dark. Two distinct types of protein methylation occur. One methylinkage is stable to basic conditions whereas a second type is base labile. The base-stable linkage is indicative of N-methylation of amino acid residues while base-lability is suggestive of carboxymethylation of amino acid residues. Labeling in the light increases the percentage of methylation that is base labile in the thylakoid fraction while no difference is observed in the amount of base-labile methylations in light-labeled and dark-labeled stromal proteins. Also suggestive of carboxymethylation is the detection of volatile [ 3 H]methyl radioactivity which increases during the labeling period and is greater in chloroplasts labeled in the light as opposed to being labeled in the dark; this implies in vivo turnover of the [ 3 H]methyl group

Genome-wide methylation analysis identified sexually dimorphic methylated regions in hybrid tilapia

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Wan, Zi Yi; Xia, Jun Hong; Lin, Grace; Wang, Le; Lin, Valerie C. L.; Yue, Gen Hua

2016-01-01

Sexual dimorphism is an interesting biological phenomenon. Previous studies showed that DNA methylation might play a role in sexual dimorphism. However, the overall picture of the genome-wide methylation landscape in sexually dimorphic species remains unclear. We analyzed the DNA methylation landscape and transcriptome in hybrid tilapia (Oreochromis spp.) using whole genome bisulfite sequencing (WGBS) and RNA-sequencing (RNA-seq). We found 4,757 sexually dimorphic differentially methylated regions (DMRs), with significant clusters of DMRs located on chromosomal regions associated with sex determination. CpG methylation in promoter regions was negatively correlated with the gene expression level. MAPK/ERK pathway was upregulated in male tilapia. We also inferred active cis-regulatory regions (ACRs) in skeletal muscle tissues from WGBS datasets, revealing sexually dimorphic cis-regulatory regions. These results suggest that DNA methylation contribute to sex-specific phenotypes and serve as resources for further investigation to analyze the functions of these regions and their contributions towards sexual dimorphisms. PMID:27782217

DNA sequence explains seemingly disordered methylation levels in partially methylated domains of Mammalian genomes.

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Dimos Gaidatzis

2014-02-01

Full Text Available For the most part metazoan genomes are highly methylated and harbor only small regions with low or absent methylation. In contrast, partially methylated domains (PMDs, recently discovered in a variety of cell lines and tissues, do not fit this paradigm as they show partial methylation for large portions (20%-40% of the genome. While in PMDs methylation levels are reduced on average, we found that at single CpG resolution, they show extensive variability along the genome outside of CpG islands and DNase I hypersensitive sites (DHS. Methylation levels range from 0% to 100% in a roughly uniform fashion with only little similarity between neighboring CpGs. A comparison of various PMD-containing methylomes showed that these seemingly disordered states of methylation are strongly conserved across cell types for virtually every PMD. Comparative sequence analysis suggests that DNA sequence is a major determinant of these methylation states. This is further substantiated by a purely sequence based model which can predict 31% (R(2 of the variation in methylation. The model revealed CpG density as the main driving feature promoting methylation, opposite to what has been shown for CpG islands, followed by various dinucleotides immediately flanking the CpG and a minor contribution from sequence preferences reflecting nucleosome positioning. Taken together we provide a reinterpretation for the nucleotide-specific methylation levels observed in PMDs, demonstrate their conservation across tissues and suggest that they are mainly determined by specific DNA sequence features.

Aberrant TET1 Methylation Closely Associated with CpG Island Methylator Phenotype in Colorectal Cancer.

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Ichimura, Norihisa; Shinjo, Keiko; An, Byonggu; Shimizu, Yasuhiro; Yamao, Kenji; Ohka, Fumiharu; Katsushima, Keisuke; Hatanaka, Akira; Tojo, Masayuki; Yamamoto, Eiichiro; Suzuki, Hiromu; Ueda, Minoru; Kondo, Yutaka

2015-08-01

Inactivation of methylcytosine dioxygenase, ten-eleven translocation (TET) is known to be associated with aberrant DNA methylation in cancers. Tumors with a CpG island methylator phenotype (CIMP), a distinct subgroup with extensive DNA methylation, show characteristic features in the case of colorectal cancer. The relationship between TET inactivation and CIMP in colorectal cancers is not well understood. The expression level of TET family genes was compared between CIMP-positive (CIMP-P) and CIMP-negative (CIMP-N) colorectal cancers. Furthermore, DNA methylation profiling, including assessment of the TET1 gene, was assessed in colorectal cancers, as well as colon polyps. The TET1 was silenced by DNA methylation in a subset of colorectal cancers as well as cell lines, expression of which was reactivated by demethylating agent. TET1 methylation was more frequent in CIMP-P (23/55, 42%) than CIMP-N (2/113, 2%, P CIMP-P, 16/40, 40%; CIMP-N, 2/24, 8%; P = 0.002), suggesting that TET1 methylation is an early event in CIMP tumorigenesis. TET1 methylation was significantly associated with BRAF mutation but not with hMLH1 methylation in the CIMP-P colorectal cancers. Colorectal cancers with TET1 methylation have a significantly greater number of DNA methylated genes and less pathological metastasis compared to those without TET1 methylation (P = 0.007 and 0.045, respectively). Our data suggest that TET1 methylation may contribute to the establishment of a unique pathway in respect to CIMP-mediated tumorigenesis, which may be incidental to hMLH1 methylation. In addition, our findings provide evidence that TET1 methylation may be a good biomarker for the prediction of metastasis in colorectal cancer. ©2015 American Association for Cancer Research.

Evaluating genome-wide DNA methylation changes in mice by Methylation Specific Digital Karyotyping

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Maruoka Shuichiro

2008-12-01

Full Text Available Abstract Background The study of genome-wide DNA methylation changes has become more accessible with the development of various array-based technologies though when studying species other than human the choice of applications are limited and not always within reach. In this study, we adapted and tested the applicability of Methylation Specific Digital Karyotyping (MSDK, a non-array based method, for the prospective analysis of epigenetic changes after perinatal nutritional modifications in a mouse model of allergic airway disease. MSDK is a sequenced based method that allows a comprehensive and unbiased methylation profiling. The method generates 21 base pairs long sequence tags derived from specific locations in the genome. The resulting tag frequencies determine in a quantitative manner the methylation level of the corresponding loci. Results Genomic DNA from whole lung was isolated and subjected to MSDK analysis using the methylation-sensitive enzyme Not I as the mapping enzyme and Nla III as the fragmenting enzyme. In a pair wise comparison of the generated mouse MSDK libraries we identified 158 loci that are significantly differentially methylated (P-value = 0.05 after perinatal dietary changes in our mouse model. Quantitative methylation specific PCR and sequence analysis of bisulfate modified genomic DNA confirmed changes in methylation at specific loci. Differences in genomic MSDK tag counts for a selected set of genes, correlated well with changes in transcription levels as measured by real-time PCR. Furthermore serial analysis of gene expression profiling demonstrated a dramatic difference in expressed transcripts in mice exposed to perinatal nutritional changes. Conclusion The genome-wide methylation survey applied in this study allowed for an unbiased methylation profiling revealing subtle changes in DNA methylation in mice maternally exposed to dietary changes in methyl-donor content. The MSDK method is applicable for mouse models

Plant methyl salicylate induces defense responses in the rhizobacterium Bacillus subtilis.

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Kobayashi, Kazuo

2015-04-01

Bacillus subtilis is a rhizobacterium that promotes plant growth and health. Cultivation of B. subtilis with an uprooted weed on solid medium produced pleat-like architectures on colonies near the plant. To test whether plants emit signals that affect B. subtilis colony morphology, we examined the effect of plant-related compounds on colony morphology. Bacillus subtilis formed mucoid colonies specifically in response to methyl salicylate, which is a plant-defense signal released in response to pathogen infection. Methyl salicylate induced mucoid colony formation by stimulating poly-γ-glutamic acid biosynthesis, which formed enclosing capsules that protected the cells from exposure to antimicrobial compounds. Poly-γ-glutamic acid synthesis depended on the DegS-DegU two-component regulatory system, which activated DegSU-dependent gene transcription in response to methyl salicylate. Bacillus subtilis did not induce plant methyl salicylate production, indicating that the most probable source of methyl salicylate in the rhizosphere is pathogen-infected plants. Methyl salicylate induced B. subtilis biosynthesis of the antibiotics bacilysin and fengycin, the latter of which exhibited inhibitory activity against the plant pathogenic fungus Fusarium oxysporum. We propose that B. subtilis may sense plants under pathogen attack via methyl salicylate, and express defense responses that protect both B. subtilis and host plants in the rhizosphere. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

A crucial role for maternal dietary methyl donor intake in epigenetic programming and fetal growth outcomes.

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McGee, Meghan; Bainbridge, Shannon; Fontaine-Bisson, Bénédicte

2018-06-01

The fetal origins of health and disease framework has identified extremes in fetal growth and birth weight as factors associated with the lifelong generation of chronic diseases such as obesity, diabetes, cardiovascular disease, and hypertension. Maternal nutrition plays a critical role in fetal and placental development, in part by providing the methyl groups required to establish the fetus's genome structure and function, notably through DNA methylation. The goal of this narrative review is to describe the role of maternal dietary methyl donor (methionine, folate, and choline) and cofactor (zinc and vitamins B2, B6, and B12) intake in one-carbon metabolism and DNA methylation in the fetus and placenta, as well as their impacts on fetal growth and lifelong health outcomes, with specific examples in animals and humans. Based on the available evidence, it is concluded that intake of different amounts of dietary methyl donors and cofactors during pregnancy may alter fetal growth and development, thus establishing a major link between early environmental exposure and disease development in the offspring later in life.

Determination of pesticide residues in fruits of Nawabshah district, Sindh, Pakistan

International Nuclear Information System (INIS)

Anwar, T.; Ahmad, I.; Tahir, S.

2011-01-01

Eight fruit samples of apple, guava, orange, grapes, pear, persimmon, banana and pear purchased from the local markets of Nawabshah district, Sindh and residues of pesticide of organophosphate (OP), pyrethroid and organochlorine (OC) (i.e., dichlorvos, fenvalerate, dimethoate, methyl parathion, fenitrothion, cypermethrin, endosulfan, deltamethrin, mevinphos, chlorpyriphos, profenofos and dicofol) were monitored in fruit samples by Gas Chromatography (GC). All the fruit samples were found contaminated except banana and among these only apple samples were found exceeding the maximum residue limits (MRL) of Codex Alimentarius Commission. (author)

MethylMeter(®): bisulfite-free quantitative and sensitive DNA methylation profiling and mutation detection in FFPE samples.

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McCarthy, David; Pulverer, Walter; Weinhaeusel, Andreas; Diago, Oscar R; Hogan, Daniel J; Ostertag, Derek; Hanna, Michelle M

2016-06-01

Development of a sensitive method for DNA methylation profiling and associated mutation detection in clinical samples. Formalin-fixed and paraffin-embedded tumors received by clinical laboratories often contain insufficient DNA for analysis with bisulfite or methylation sensitive restriction enzymes-based methods. To increase sensitivity, methyl-CpG DNA capture and Coupled Abscription PCR Signaling detection were combined in a new assay, MethylMeter(®). Gliomas were analyzed for MGMT methylation, glioma CpG island methylator phenotype and IDH1 R132H. MethylMeter had 100% assay success rate measuring all five biomarkers in formalin-fixed and paraffin-embedded tissue. MGMT methylation results were supported by survival and mRNA expression data. MethylMeter is a sensitive and quantitative method for multitarget DNA methylation profiling and associated mutation detection. The MethylMeter-based GliomaSTRAT assay measures methylation of four targets and one mutation to simultaneously grade gliomas and predict their response to temozolomide. This information is clinically valuable in management of gliomas.

CpG island methylator phenotype-low (CIMP-low) colorectal cancer shows not only few methylated CIMP-high-specific CpG islands, but also low-level methylation at individual loci.

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Kawasaki, Takako; Ohnishi, Mutsuko; Nosho, Katsuhiko; Suemoto, Yuko; Kirkner, Gregory J; Meyerhardt, Jeffrey A; Fuchs, Charles S; Ogino, Shuji

2008-03-01

The CpG island methylator phenotype (CIMP or CIMP-high) with widespread promoter methylation is a distinct phenotype in colorectal cancer. However, the concept of CIMP-low with less extensive CpG island methylation is still evolving. Our aim is to examine whether density of methylation in individual CpG islands was different between CIMP-low and CIMP-high tumors. Utilizing MethyLight technology and 889 population-based colorectal cancers, we quantified DNA methylation (methylation index, percentage of methylated reference) at 14 CpG islands, including 8 CIMP-high-specific loci (CACNA1G, CDKN2A (p16), CRABP1, IGF2, MLH1, NEUROG1, RUNX3 and SOCS1). Methylation positivity in each locus was defined as methylation index>4. Low-level methylation (methylation index>0, CIMP-high-specific locus was significantly more common in 340 CIMP-low tumors (1/8-5/8 methylation-positive loci) than 133 CIMP-high tumors (> or =6/8 methylation-positive loci) and 416 CIMP-0 tumors (0/8 methylation-positive loci) (PCIMP-high, low-level methylation, was not persistently more prevalent in CIMP-low tumors. In conclusion, compared to CIMP-high and CIMP-0 tumors, CIMP-low colorectal cancers show not only few methylated CIMP-high-specific CpG islands, but also more frequent low-level methylation at individual loci. Our data may provide supporting evidence for a difference in pathogenesis of DNA methylation between CIMP-low and CIMP-high tumors.

Origin and fate of 4-methyl steroid hydrocarbons. I. Diagenesis of 4-methyl sterenes

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Wolff, G.A.; Lamb, N.A.; Maxwell, J.R.

1986-03-01

Treatment of 4-methylcholest-4-ene under mild acid conditions at low temperatures gives chemical evidence for certain features seen in the distributions of sedimentary 4-methyl steroid hydrocarbons, and further indicates that many low temperature diagenetic reactions of steroids are explicable in terms of acid catalyzed rearrangements. Specifically, the results provide: (i) Indirect evidence that the 4-ene skeleton is a key intermediate in the dehydration of 4-methyl stanols in sediments. (ii) An explanation for the distribution of 4-methyl sterenes and A-nor sterenes in the lacustrine Messel shale (Eocene). (iii) An explanation for the presence of 4..beta..-methyl steranes in relatively immature sedimentary rocks, despite the precursor stanols having the 4..cap alpha..-methyl configuration. With increasing maturity in the Paris Basin shales (Lower Toarcian), the less stable 4..beta..-methyl steranes decrease gradually in abundance relative to their 4..cap alpha..-methyl counterparts, at a rate fairly similar to the change in pristane stereochemistry.

Analysis of DNA Cytosine Methylation Patterns Using Methylation-Sensitive Amplification Polymorphism (MSAP).

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Guevara, María Ángeles; de María, Nuria; Sáez-Laguna, Enrique; Vélez, María Dolores; Cervera, María Teresa; Cabezas, José Antonio

2017-01-01

Different molecular techniques have been developed to study either the global level of methylated cytosines or methylation at specific gene sequences. One of them is the methylation-sensitive amplified polymorphism technique (MSAP) which is a modification of amplified fragment length polymorphism (AFLP). It has been used to study methylation of anonymous CCGG sequences in different fungi, plants, and animal species. The main variation of this technique resides on the use of isoschizomers with different methylation sensitivity (such as HpaII and MspI) as a frequent-cutter restriction enzyme. For each sample, MSAP analysis is performed using both EcoRI/HpaII- and EcoRI/MspI-digested samples. A comparative analysis between EcoRI/HpaII and EcoRI/MspI fragment patterns allows the identification of two types of polymorphisms: (1) methylation-insensitive polymorphisms that show common EcoRI/HpaII and EcoRI/MspI patterns but are detected as polymorphic amplified fragments among samples and (2) methylation-sensitive polymorphisms which are associated with the amplified fragments that differ in their presence or absence or in their intensity between EcoRI/HpaII and EcoRI/MspI patterns. This chapter describes a detailed protocol of this technique and discusses the modifications that can be applied to adjust the technology to different species of interest.

Evidence for methyl group transfer between the methyl-accepting chemotaxis proteins in Bacillus subtilis

International Nuclear Information System (INIS)

Bedale, W.A.; Nettleton, D.O.; Sopata, C.S.; Thoelke, M.S.; Ordal, G.W.

1988-01-01

The authors present evidence for methyl (as methyl or methoxy) transfer from the methyl-accepting chemotaxis proteins H1 and possibly H3 of Bacillus subtilis to the methyl-accepting chemotaxis protein H2. This methyl transfer, which has been observed in vitro was strongly stimulated by the chemoattractant aspartate and thus may plan an important role in the sensory processing system of this organism. Although radiolabeling of H1 and H3 began at once after the addition of [ 3 H] methionine, radiolabeling of H2 showed a lag. Furthermore, the addition of excess nonradioactive methionine caused immediate exponential delabeling of H1 and H3 while labeling of H2 continued to increase. Methylation of H2 required the chemotactic methyltransferase, probably to first methylate H1 and H3. Aspartate caused increased labeling of H2 and strongly decreased labeling of H1 and H3 after the addition of nonradioactive methionine. Without the addition of nonradioactive methionine, aspartate caused demethylation of H1 and to a lesser extent H3, with an approximately equal increase of methylation of H2

[Analysis of genomic DNA methylation level in radish under cadmium stress by methylation-sensitive amplified polymorphism technique].

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Yang, Jin-Lan; Liu, Li-Wang; Gong, Yi-Qin; Huang, Dan-Qiong; Wang, Feng; He, Ling-Li

2007-06-01

The level of cytosine methylation induced by cadmium in radish (Raphanus sativus L.) genome was analysed using the technique of methylation-sensitive amplified polymorphism (MSAP). The MSAP ratios in radish seedling exposed to cadmium chloride at the concentration of 50, 250 and 500 mg/L were 37%, 43% and 51%, respectively, and the control was 34%; the full methylation levels (C(m)CGG in double strands) were at 23%, 25% and 27%, respectively, while the control was 22%. The level of increase in MSAP and full methylation indicated that de novo methylation occurred in some 5'-CCGG sites under Cd stress. There was significant positive correlation between increase of total DNA methylation level and CdCl(2) concentration. Four types of MSAP patterns: de novo methylation, de-methylation, atypical pattern and no changes of methylation pattern were identified among CdCl(2) treatments and the control. DNA methylation alteration in plants treated with CdCl(2) was mainly through de novo methylation.

Reaction products from N-methyl-N-nitrosourea and deoxyribonucleic acid containing thymidine residues. Synthesis and identification of a new methylation product, O4-methyl-thymidine

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Lawley, P. D.; Orr, D. J.; Shah, S. A.; Farmer, P. B.; Jarman, M.

1973-01-01

1. DNA was treated with N-methyl-N-nitrosourea at pH7–8, 37°C, degraded to yield 3- and 7-methylpurines and deoxyribonucleosides and the reaction products were separated by chromatography on ion-exchange resins. The following methods for identification and determination of products were used: with unlabelled N-methyl-N-nitrosourea, u.v. absorption; use of methyl-14C-labelled N-methyl-N-nitrosourea and use of [14C]thymine-labelled DNA. 2. The synthesis of O4-methylthymidine and its identification by u.v. and mass spectroscopy are reported. 3. 3-Methylthymidine and O4-methylthymidine were found as methylation products from N-methyl-N-nitrosourea with thymidine and with DNA, in relatively small yields. Unidentified products containing thymine were found in enzymic digests of N-methyl-N-nitrosourea-treated DNA, which may be phosphotriesters. 4. The possible role of formation of methylthymines in mutagenesis by N-methyl-N-nitrosourea is discussed. PMID:4798180

Sensitive Detection of Organophosphorus Pesticides in Medicinal Plants Using Ultrasound-Assisted Dispersive Liquid-Liquid Microextraction Combined with Sweeping Micellar Electrokinetic Chromatography.

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Wei, Jin-Chao; Hu, Ji; Cao, Ji-Liang; Wan, Jian-Bo; He, Cheng-Wei; Hu, Yuan-Jia; Hu, Hao; Li, Peng

2016-02-03

A simple, rapid, and sensitive method using ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) combined with sweeping micellar electrokinetic chromatography (sweeping-MEKC) has been developed for the determination of nine organophosphorus pesticides (chlorfenvinphos, parathion, quinalphos, fenitrothion, azinphos-ethyl, parathion-methyl, fensulfothion, methidathion, and paraoxon). The important parameters that affect the UA-DLLME and sweeping efficiency were investigated. Under the optimized conditions, the proposed method provided 779.0-6203.5-fold enrichment of the nine pesticides compared to the normal MEKC method. The limits of detection ranged from 0.002 to 0.008 mg kg(-1). The relative standard deviations of the peak area ranged from 1.2 to 6.5%, indicating the good repeatability of the method. Finally, the developed UA-DLLME-sweeping-MEKC method has been successfully applied to the analysis of the investigated pesticides in several medicinal plants, including Lycium chinense, Dioscorea opposite, Codonopsis pilosula, and Panax ginseng, indicating that this method is suitable for the determination of trace pesticide residues in real samples with complex matrices.

Synthesis of [methyl-14C]crotonobetaine from DL-[methyl-14C]carnitine

International Nuclear Information System (INIS)

Loester, H.; Seim, H.

1996-01-01

The causes of carnitine deficiency syndromes are not completely understood, but decomposition of L-carnitine in vivo is likely to be involved. Carnitine is metabolized to γ-butyrobetaine, and crotonobetaine is probably an intermediate in this pathway. To validate experimentally the precursor-product relationship between the three physiologically occuring γ-betaines - L-carnitine, crotonobetaine, γ-butyrobetaine - labelling with stable or radioactive isotopes became necessary. Methyl-labelled carnitine isomers (L(-)-, D(+)- or DL-) or γ-butyrobetaine can be easily synthesized by methylation of 4-amino-3-hydroxybutyric acid isomers or 4-aminobutyric acid, respectively. Because of problems with the 4-aminocrotonic acid, we synthesized labelled crotonbetaine from labelled carnitine. Thus, DL-[methyl- 14 C]carnitine was dehydrated by reaction with concentrated sulfuric acid. After removal of the latter the products were separated and purified by ion exchange chromatography on DOWEX 50 WX8 (200 - 400 mesh) and gradient elution with hydrochloric acid. In addition to the labelled main product [methyl- 14 C]crotonobetaine (yield about 50 %), [methyl- 14 C]glycine betaine and [methyl- 14 C]acetonyl-trimethylammonium (ATMA) were formed. The end products were identified by combined thin layer chromatography/autoradiography and quantified by liquid scintillation counting. (Author)

Traumatic stress and accelerated DNA methylation age: A meta-analysis.

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Wolf, Erika J; Maniates, Hannah; Nugent, Nicole; Maihofer, Adam X; Armstrong, Don; Ratanatharathorn, Andrew; Ashley-Koch, Allison E; Garrett, Melanie; Kimbrel, Nathan A; Lori, Adriana; Va Mid-Atlantic Mirecc Workgroup; Aiello, Allison E; Baker, Dewleen G; Beckham, Jean C; Boks, Marco P; Galea, Sandro; Geuze, Elbert; Hauser, Michael A; Kessler, Ronald C; Koenen, Karestan C; Miller, Mark W; Ressler, Kerry J; Risbrough, Victoria; Rutten, Bart P F; Stein, Murray B; Ursano, Robert J; Vermetten, Eric; Vinkers, Christiaan H; Uddin, Monica; Smith, Alicia K; Nievergelt, Caroline M; Logue, Mark W

2018-06-01

Recent studies examining the association between posttraumatic stress disorder (PTSD) and accelerated aging, as defined by DNA methylation-based estimates of cellular age that exceed chronological age, have yielded mixed results. We conducted a meta-analysis of trauma exposure and PTSD diagnosis and symptom severity in association with accelerated DNA methylation age using data from 9 cohorts contributing to the Psychiatric Genomics Consortium PTSD Epigenetics Workgroup (combined N = 2186). Associations between demographic and cellular variables and accelerated DNA methylation age were also examined, as was the moderating influence of demographic variables. Meta-analysis of regression coefficients from contributing cohorts revealed that childhood trauma exposure (when measured with the Childhood Trauma Questionnaire) and lifetime PTSD severity evidenced significant, albeit small, meta-analytic associations with accelerated DNA methylation age (ps = 0.028 and 0.016, respectively). Sex, CD4T cell proportions, and natural killer cell proportions were also significantly associated with accelerated DNA methylation age (all ps age. There was no evidence of moderation of the trauma or PTSD variables by demographic factors. Results suggest that traumatic stress is associated with advanced epigenetic age and raise the possibility that cells integral to immune system maintenance and responsivity play a role in this. This study highlights the need for additional research into the biological mechanisms linking traumatic stress to accelerated DNA methylation age and the importance of furthering our understanding of the neurobiological and health consequences of PTSD. Published by Elsevier Ltd.

Methyl methacrylate oligomerically-modified clay and its poly(methyl methacrylate) nanocomposites

International Nuclear Information System (INIS)

Zheng Xiaoxia; Jiang, David D.; Wilkie, Charles A.

2005-01-01

A methyl methacrylate oligomerically-modified clay was used to prepare poly(methyl methacrylate) clay nanocomposites by melt blending and the effect of the clay loading level on the modified clay and corresponding nanocomposite was studied. These nanocomposites were characterized by X-ray diffraction, transmission electron microscopy, thermogravimetric analysis and cone calorimetry. The results show a mixed intercalated/delaminated morphology with good nanodispersion. The compatibility between the methylacrylate-subsituted clay and poly(methyl methacrylate) (PMMA) are greatly improved compared to other oligomerically-modified clays

Usability of human Infinium MethylationEPIC BeadChip for mouse DNA methylation studies.

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Needhamsen, Maria; Ewing, Ewoud; Lund, Harald; Gomez-Cabrero, David; Harris, Robert Adam; Kular, Lara; Jagodic, Maja

2017-11-15

The advent of array-based genome-wide DNA methylation methods has enabled quantitative measurement of single CpG methylation status at relatively low cost and sample input. Whereas the use of Infinium Human Methylation BeadChips has shown great utility in clinical studies, no equivalent tool is available for rodent animal samples. We examined the feasibility of using the new Infinium MethylationEPIC BeadChip for studying DNA methylation in mouse. In silico, we identified 19,420 EPIC probes (referred as mEPIC probes), which align with a unique best alignment score to the bisulfite converted reference mouse genome mm10. Further annotation revealed that 85% of mEPIC probes overlapped with mm10.refSeq genes at different genomic features including promoters (TSS1500 and TSS200), 1st exons, 5'UTRs, 3'UTRs, CpG islands, shores, shelves, open seas and FANTOM5 enhancers. Hybridization of mouse samples to Infinium Human MethylationEPIC BeadChips showed successful measurement of mEPIC probes and reproducibility between inter-array biological replicates. Finally, we demonstrated the utility of mEPIC probes for data exploration such as hierarchical clustering. Given the absence of cost and labor convenient genome-wide technologies in the murine system, our findings show that the Infinium MethylationEPIC BeadChip platform is suitable for investigation of the mouse methylome. Furthermore, we provide the "mEPICmanifest" with genomic features, available to users of Infinium Human MethylationEPIC arrays for mouse samples.

A novel method to quantify local CpG methylation density by regional methylation elongation assay on microarray

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Qiao Yingjuan

2008-01-01

Full Text Available Abstract Background DNA methylation based techniques are important tools in both clinical diagnostics and therapeutics. But most of these methods only analyze a few CpG sites in a target region. Indeed, difference of site-specific methylation may also lead to a change of methylation density in many cases, and it has been found that the density of methylation is more important than methylation of single CpG site for gene silencing. Results We have developed a novel approach for quantitative analysis of CpG methylation density on the basis of microarray-based hybridization and incorporation of Cy5-dCTP into the Cy3 labeled target DNA by using Taq DNA Polymerase on microarray. The quantification is achieved by measuring Cy5/Cy3 signal ratio which is proportional to methylation density. This methylation-sensitive technique, termed RMEAM (regional methylation elongation assay on microarray, provides several advantages over existing methods used for methylation analysis. It can determine an exact methylation density of the given region, and has potential of high throughput. We demonstrate a use of this method in determining the methylation density of the promoter region of the tumor-related gene MLH1, TERT and MGMT in colorectal carcinoma patients. Conclusion This technique allows for quantitative analysis of regional methylation density, which is the representative of all allelic methylation patterns in the sample. The results show that this technique has the characteristics of simplicity, rapidness, specificity and high-throughput.

Maternal Methyl-Group Donor Intake and Global DNA (HydroxyMethylation before and during Pregnancy

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Sara Pauwels

2016-08-01

Full Text Available It is still unclear to which extent methyl-group intake during pregnancy can affect maternal global DNA (hydroxylmethylation. Pregnancy methylation profiling and its link with methyl-group intake in a healthy population could enhance our understanding of the development of pregnancy related disorders. One hundred forty-eight women were enrolled in the MANOE (MAternal Nutrition and Offspring’s Epigenome study. Thiry-four women were enrolled before pregnancy and 116 during the first trimester of pregnancy. Global DNA (hydroxymethylation in blood using LC-MS/MS and dietary methyl-group intake (methionine, folate, betaine, and choline using a food-frequency questionnaire were estimated pre-pregnancy, during each trimester, and at delivery. Global DNA (hydroxymethylation levels were highest pre-pregnancy and at weeks 18–22 of pregnancy. We observed a positive relation between folic acid and global DNA methylation (p = 0.04 and hydroxymethylation (p = 0.04. A high intake of methionine pre-pregnancy and in the first trimester showed lower (hydroxymethylation percentage in weeks 11–13 and weeks 18–22, respectively. Choline and betaine intake in the first weeks was negatively associated with hydroxymethylation. Women with a high intake of these three methyl groups in the second and third trimester showed higher hyrdoxymethylation/methylation levels in the third trimester. To conclude, a time trend in DNA (hydroxymethylation was found and women with higher methyl-group intake showed higher methylation in the third trimester, and not in earlier phases of pregnancy.

21 CFR 177.1830 - Styrene-methyl methacrylate copolymers.

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2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Styrene-methyl methacrylate copolymers. 177.1830 Section 177.1830 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and Repeated Us...

Effects of nickel, chromate, and arsenite on histone 3 lysine methylation

International Nuclear Information System (INIS)

Zhou Xue; Li Qin; Arita, Adriana; Sun Hong; Costa, Max

2009-01-01

Occupational exposure to nickel (Ni), chromium (Cr), and arsenic (As) containing compounds has been associated with lung cancer and other adverse health effects. Their carcinogenic properties may be attributable in part, to activation and/or repression of gene expression induced by changes in the DNA methylation status and histone tail post-translational modifications. Here we show that individual treatment with nickel, chromate, and arsenite all affect the gene activating mark H3K4 methylation. We found that nickel (1 mM), chromate (10 μM), and arsenite (1 μM) significantly increase tri-methyl H3K4 after 24 h exposure in human lung carcinoma A549 cells. Seven days of exposure to lower levels of nickel (50 and 100 μM), chromate (0.5 and 1 μM) or arsenite (0.1, 0.5 and 1 μM) also increased tri-methylated H3K4 in A549 cells. This mark still remained elevated and inherited through cell division 7 days following removal of 1 μM arsenite. We also demonstrate by dual staining immunofluorescence microscopy that both H3K4 tri-methyl and H3K9 di-methyl marks increase globally after 24 h exposure to each metal treatment in A549 cells. However, the tri-methyl H3K4 and di-methyl H3K9 marks localize in different regions in the nucleus of the cell. Thus, our study provides further evidence that a mechanism(s) of carcinogenicity of nickel, chromate, and arsenite metal compounds may involve alterations of various histone tail modifications that may in turn affect the expression of genes that may cause transformation

Detection of DNA methylation changes in micropropagated banana plants using methylation-sensitive amplification polymorphism (MSAP).

Science.gov (United States)

Peraza-Echeverria, S; Herrera-Valencia, V A.; Kay, A -J.

2001-07-01

The extent of DNA methylation polymorphisms was evaluated in micropropagated banana (Musa AAA cv. 'Grand Naine') derived from either the vegetative apex of the sucker or the floral apex of the male inflorescence using the methylation-sensitive amplification polymorphism (MSAP) technique. In all, 465 fragments, each representing a recognition site cleaved by either or both of the isoschizomers were amplified using eight combinations of primers. A total of 107 sites (23%) were found to be methylated at cytosine in the genome of micropropagated banana plants. In plants micropropagated from the male inflorescence explant 14 (3%) DNA methylation events were polymorphic, while plants micropropagated from the sucker explant produced 8 (1.7%) polymorphisms. No DNA methylation polymorphisms were detected in conventionally propagated banana plants. These results demonstrated the usefulness of MSAP to detect DNA methylation events in micropropagated banana plants and indicate that DNA methylation polymorphisms are associated with micropropagation.

DNA methylation profiling reveals the presence of population-specific signatures correlating with phenotypic characteristics.

Science.gov (United States)

Giri, Anil K; Bharadwaj, Soham; Banerjee, Priyanka; Chakraborty, Shraddha; Parekatt, Vaisak; Rajashekar, Donaka; Tomar, Abhishek; Ravindran, Aarthi; Basu, Analabha; Tandon, Nikhil; Bharadwaj, Dwaipayan

2017-06-01

Phenotypic characteristics are known to vary substantially among different ethnicities around the globe. These variations are mediated by number of stochastic events and cannot be attributed to genetic architecture alone. DNA methylation is a well-established mechanism that sculpts our epigenome influencing phenotypic variation including disease manifestation. Since DNA methylation is an important determinant for health issues of a population, it demands a thorough investigation of the natural differences in genome wide DNA methylation patterns across different ethnic groups. This study is based on comparative analyses of methylome from five different ethnicities with major focus on Indian subjects. The current study uses hierarchical clustering approaches, principal component analysis and locus specific differential methylation analysis on Illumina 450K methylation data to compare methylome of different ethnic subjects. Our data indicates that the variations in DNA methylation patterns of Indians are less among themselves compared to other global population. It empirically correlated with dietary, cultural and demographical divergences across different ethnic groups. Our work further suggests that Indians included in this study, despite their genetic similarity with the Caucasian population, are in close proximity with Japanese in terms of their methylation signatures.

DNA methylation

DEFF Research Database (Denmark)

Williams, Kristine; Christensen, Jesper; Helin, Kristian

2012-01-01

DNA methylation is involved in key cellular processes, including X-chromosome inactivation, imprinting and transcriptional silencing of specific genes and repetitive elements. DNA methylation patterns are frequently perturbed in human diseases such as imprinting disorders and cancer. The recent...... discovery that the three members of the TET protein family can convert 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC) has provided a potential mechanism leading to DNA demethylation. Moreover, the demonstration that TET2 is frequently mutated in haematopoietic tumours suggests that the TET...... proteins are important regulators of cellular identity. Here, we review the current knowledge regarding the function of the TET proteins, and discuss various mechanisms by which they contribute to transcriptional control. We propose that the TET proteins have an important role in regulating DNA methylation...

Litigation Technical Support and Services, Rocky Mountain Arsenal. Biota Remedial Investigation (Version 3.2). Volume 2

Science.gov (United States)

1989-05-01

Quantificationnf oLIxi1Xffacs .5-73 5.1.18 METHYL PARATHION 5-73 5.1.18.1 Agua ±c-Ecasystems 5-74 5.1. 18.2 larXesrial-Ecasystems 5-74 5.1.18.3... situ exposure. The data were compiled primarily for later use in the endangerment assessments, and will be modified as the Phase II data for abiotic...el al., 1984). In situ - in the natural or original position: in an organism’s natural environment or habitat. Instar - growth stage or period of

Social Crowding during Development Causes Changes in GnRH1 DNA Methylation.

Science.gov (United States)

Alvarado, Sebastian G; Lenkov, Kapa; Williams, Blake; Fernald, Russell D

2015-01-01

Gestational and developmental cues have important consequences for long-term health, behavior and adaptation to the environment. In addition, social stressors cause plastic molecular changes in the brain that underlie unique behavioral phenotypes that also modulate fitness. In the adult African cichlid, Astatotilapia burtoni, growth and social status of males are both directly regulated by social interactions in a dynamic social environment, which causes a suite of plastic changes in circuits, cells and gene transcription in the brain. We hypothesized that a possible mechanism underlying some molecular changes might be DNA methylation, a reversible modification made to cytosine nucleotides that is known to regulate gene function. Here we asked whether changes in DNA methylation of the GnRH1 gene, the central regulator of the reproductive axis, were altered during development of A. burtoni. We measured changes in methylation state of the GnRH1 gene during normal development and following the gestational and developmental stress of social crowding. We found differential DNA methylation within developing juveniles between 14-, 28- and 42-day-old. Following gestational crowding of mouth brooding mothers, we saw differential methylation and transcription of GnRH1 in their offspring. Taken together, our data provides evidence for social control of GnRH1 developmental responses to gestational cues through DNA methylation.

The origin and fate of 4-methyl steroid hydrocarbons. I. Diagenesis of 4-methyl sterenes

Science.gov (United States)

Wolff, George A.; Lamb, Neil A.; Maxwell, James R.

1986-03-01

Treatment of 4-methylcholest-4-ene under mild acid conditions at low temperatures gives chemical evidence for certain features seen in the distributions of sedimentary 4-methyl steroid hydrocarbons, and further indicates that many low temperature diagenetic reactions of steroids are explicable in terms of acid catalysed rearrangements. Specifically, the results provide: (i) Indirect evidence that the 4-ene skeleton is a key intermediate in the dehydration of 4-methyl stanols in sediments. (ii) An explanation for the distribution of 4-methyl sterenes and A-nor sterenes in the lacustrine Messel shale (Eocene). (iii) An explanation for the presence of 4β-methyl steranes in relatively immature sedimentary rocks, despite the precursor stanols having the 4α-methyl configuration. With increasing maturity in the Paris Basin shales (Lower Toarcian), the less stable 4β-methyl steranes decrease gradually in abundance relative to their 4α-methyl counterparts, at a rate fairly similar to the change in pristane stereochemistry.

A genome-wide methylation study on obesity: differential variability and differential methylation.

Science.gov (United States)

Xu, Xiaojing; Su, Shaoyong; Barnes, Vernon A; De Miguel, Carmen; Pollock, Jennifer; Ownby, Dennis; Shi, Hidong; Zhu, Haidong; Snieder, Harold; Wang, Xiaoling

2013-05-01

Besides differential methylation, DNA methylation variation has recently been proposed and demonstrated to be a potential contributing factor to cancer risk. Here we aim to examine whether differential variability in methylation is also an important feature of obesity, a typical non-malignant common complex disease. We analyzed genome-wide methylation profiles of over 470,000 CpGs in peripheral blood samples from 48 obese and 48 lean African-American youth aged 14-20 y old. A substantial number of differentially variable CpG sites (DVCs), using statistics based on variances, as well as a substantial number of differentially methylated CpG sites (DMCs), using statistics based on means, were identified. Similar to the findings in cancers, DVCs generally exhibited an outlier structure and were more variable in cases than in controls. By randomly splitting the current sample into a discovery and validation set, we observed that both the DVCs and DMCs identified from the first set could independently predict obesity status in the second set. Furthermore, both the genes harboring DMCs and the genes harboring DVCs showed significant enrichment of genes identified by genome-wide association studies on obesity and related diseases, such as hypertension, dyslipidemia, type 2 diabetes and certain types of cancers, supporting their roles in the etiology and pathogenesis of obesity. We generalized the recent finding on methylation variability in cancer research to obesity and demonstrated that differential variability is also an important feature of obesity-related methylation changes. Future studies on the epigenetics of obesity will benefit from both statistics based on means and statistics based on variances.

Detection and discrimination of maintenance and de novo CpG methylation events using MethylBreak.

Science.gov (United States)

Hsu, William; Mercado, Augustus T; Hsiao, George; Yeh, Jui-Ming; Chen, Chung-Yung

2017-05-15

Understanding the principles governing the establishment and maintenance activities of DNA methyltransferases (DNMTs) can help in the development of predictive biomarkers associated with genetic disorders and diseases. A detection system was developed that distinguishes and quantifies methylation events using methylation-sensitive endonucleases and molecular beacon technology. MethylBreak (MB) is a 22-mer oligonucleotide with one hemimethylated and two unmethylated CpG sites, which are also recognition sites for Sau96I and SacII, and is attached to a fluorophore and a quencher. Maintenance methylation was quantified by fluorescence emission due to the digestion of SacII when the hemimethylated CpG site is methylated, which inhibits Sau96I cleavage. The signal difference between SacII digestion of both MB substrate and maintenance methylated MB corresponds to de novo methylation event. Our technology successfully discriminated and measured both methylation activities at different concentrations of MB and achieved a high correlation coefficient of R 2 =0.997. Additionally, MB was effectively applied to normal and cancer cell lines and in the analysis of enzymatic kinetics and RNA inhibition of recombinant human DNMT1. Copyright © 2017 Elsevier B.V. All rights reserved.

Residential proximity to methyl bromide use and birth outcomes in an agricultural population in California.

Science.gov (United States)

Gemmill, Alison; Gunier, Robert B; Bradman, Asa; Eskenazi, Brenda; Harley, Kim G

2013-06-01

Methyl bromide, a fungicide often used in strawberry cultivation, is of concern for residents who live near agricultural applications because of its toxicity and potential for drift. Little is known about the effects of methyl bromide exposure during pregnancy. We investigated the relationship between residential proximity to methyl bromide use and birth outcomes. Participants were from the CHAMACOS (Center for the Health Assessment of Mothers and Children of Salinas) study (n = 442), a longitudinal cohort study examining the health effects of environmental exposures on pregnant women and their children in an agricultural community in northern California. Using data from the California Pesticide Use Reporting system, we employed a geographic information system to estimate the amount of methyl bromide applied within 5 km of a woman's residence during pregnancy. Multiple linear regression models were used to estimate associations between trimester-specific proximity to use and birth weight, length, head circumference, and gestational age. High methyl bromide use (vs. no use) within 5 km of the home during the second trimester was negatively associated with birth weight (β = -113.1 g; CI: -218.1, -8.1), birth length (β = -0.85 cm; CI: -1.44, -0.27), and head circumference (β = -0.33 cm; CI: -0.67, 0.01). These outcomes were also associated with moderate methyl bromide use during the second trimester. Negative associations with fetal growth parameters were stronger when larger (5 km and 8 km) versus smaller (1 km and 3 km) buffer zones were used to estimate exposure. Residential proximity to methyl bromide use during the second trimester was associated with markers of restricted fetal growth in our study.

Mobility and molecular ions of dimethyl methyl phosphonate, methyl salicylate and acetone

Science.gov (United States)

Nowak, D. M.

1983-06-01

The mobilities of positive and negative reactant ions are reported for (H2O)nH(+); (H2O)2O2 and (H2O)2CO3(-) ion clusters. The formation of positive DMMP monomer and dimer is reported, and equilbria molecular reactions are reported. Acetone is reported as forming a dimer at 81 ppb with a reduced mobility (K sub o) of 1.82, Methyl salicylate is shown to form a protonated and hydrated positive monomer. Mixtures of DMMP and methyl salicylate with acetone showed a substantial change in DMMP ion clustering and little or no change in the methyl salicylate mobility spectra. Negative ions were not observed for DMMP, methyl salicylate, acetone and the mixtures under the conditions reported.

Androgen receptor function links human sexual dimorphism to DNA methylation.

Directory of Open Access Journals (Sweden)

Ole Ammerpohl

Full Text Available Sex differences are well known to be determinants of development, health and disease. Epigenetic mechanisms are also known to differ between men and women through X-inactivation in females. We hypothesized that epigenetic sex differences may also result from sex hormone functions, in particular from long-lasting androgen programming. We aimed at investigating whether inactivation of the androgen receptor, the key regulator of normal male sex development, is associated with differences of the patterns of DNA methylation marks in genital tissues. To this end, we performed large scale array-based analysis of gene methylation profiles on genomic DNA from labioscrotal skin fibroblasts of 8 males and 26 individuals with androgen insensitivity syndrome (AIS due to inactivating androgen receptor gene mutations. By this approach we identified differential methylation of 167 CpG loci representing 162 unique human genes. These were significantly enriched for androgen target genes and low CpG content promoter genes. Additional 75 genes showed a significant increase of heterogeneity of methylation in AIS compared to a high homogeneity in normal male controls. Our data show that normal and aberrant androgen receptor function is associated with distinct patterns of DNA-methylation marks in genital tissues. These findings support the concept that transcription factor binding to the DNA has an impact on the shape of the DNA methylome. These data which derived from a rare human model suggest that androgen programming of methylation marks contributes to sexual dimorphism in the human which might have considerable impact on the manifestation of sex-associated phenotypes and diseases.

DNA Methylation in Embryo Development: Epigenetic Impact of ART (Assisted Reproductive Technologies).

Science.gov (United States)

Canovas, Sebastian; Ross, Pablo J; Kelsey, Gavin; Coy, Pilar

2017-11-01

DNA methylation can be considered a component of epigenetic memory with a critical role during embryo development, and which undergoes dramatic reprogramming after fertilization. Though it has been a focus of research for many years, the reprogramming mechanism is still not fully understood. Recent results suggest that absence of maintenance at DNA replication is a major factor, and that there is an unexpected role for TET3-mediated oxidation of 5mC to 5hmC in guarding against de novo methylation. Base-resolution and genome-wide profiling methods are enabling more comprehensive assessments of the extent to which ART might impair DNA methylation reprogramming, and which sequence elements are most vulnerable. Indeed, as we also review here, studies showing the effect of culture media, ovarian stimulation or embryo transfer on the methylation pattern of embryos emphasize the need to face ART-associated defects and search for strategies to mitigate adverse effects on the health of ART-derived children. © 2017 WILEY Periodicals, Inc.

Evolution of DNA Methylation across Insects.

Science.gov (United States)

Bewick, Adam J; Vogel, Kevin J; Moore, Allen J; Schmitz, Robert J

2017-03-01

DNA methylation contributes to gene and transcriptional regulation in eukaryotes, and therefore has been hypothesized to facilitate the evolution of plastic traits such as sociality in insects. However, DNA methylation is sparsely studied in insects. Therefore, we documented patterns of DNA methylation across a wide diversity of insects. We predicted that underlying enzymatic machinery is concordant with patterns of DNA methylation. Finally, given the suggestion that DNA methylation facilitated social evolution in Hymenoptera, we tested the hypothesis that the DNA methylation system will be associated with presence/absence of sociality among other insect orders. We found DNA methylation to be widespread, detected in all orders examined except Diptera (flies). Whole genome bisulfite sequencing showed that orders differed in levels of DNA methylation. Hymenopteran (ants, bees, wasps and sawflies) had some of the lowest levels, including several potential losses. Blattodea (cockroaches and termites) show all possible patterns, including a potential loss of DNA methylation in a eusocial species whereas solitary species had the highest levels. Species with DNA methylation do not always possess the typical enzymatic machinery. We identified a gene duplication event in the maintenance DNA methyltransferase 1 (DNMT1) that is shared by some Hymenoptera, and paralogs have experienced divergent, nonneutral evolution. This diversity and nonneutral evolution of underlying machinery suggests alternative DNA methylation pathways may exist. Phylogenetically corrected comparisons revealed no evidence that supports evolutionary association between sociality and DNA methylation. Future functional studies will be required to advance our understanding of DNA methylation in insects. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

DNA Methylation in Newborns and Maternal Smoking in Pregnancy : Genome-wide Consortium Meta-analysis

NARCIS (Netherlands)

Joubert, Bonnie R.; Felix, Janine F.; Yousefi, Paul; Bakulski, Kelly M.; Just, Allan C.; Breton, Carrie; Reese, Sarah E.; Markunas, Christina A.; Richmond, Rebecca C.; Xu, Chengjian; Kupers, Leanne K.; Oh, Sam S.; Hoyo, Cathrine; Gruzieva, Olena; Soderhal, Cilla; Salas, Lucas A.; Baiz, Nour; Zhang, Hongmei; Lepeule, Johanna; Ruiz, Carlos; Ligthart, Symen; Wang, Tianyuan; Taylor, Jack A.; Duijts, Liesbeth; Sharp, Gemma C.; Jankipersadsing, Soesma A.; Nilsen, Roy M.; Vaez, Ahmad; Fallin, M. Daniele; Hu, Donglei; Litonjua, Augusto A.; Fuemmeler, Bernard F.; Huen, Karen; Kere, Juha; Kull, Inger; Munthe-Kaas, Monica Cheng; Gehring, Ulrike; Bustamante, Mariona; Saurel-Coubizolles, Marie Jose; Quraishi, Bilal M.; Ren, Jie; Tost, Jorg; Gonzalez, Juan R.; Peters, Marjolein J.; Haberg, Siri E.; Xu, Zongli; van Meurs, Joyce B.; Gaunt, Tom R.; Kerkhof, Marjan; Corpeleijn, Eva; Feinberg, Andrew P.; Eng, Celeste; Baccarelli, Andrea A.; Neelon, Sara E. Benjamin; Bradman, Asa; Merid, Simon Kebede; Bergstrom, Anna; Herceg, Zdenko; Hernandez-Vargas, Hector; Brunekreef, Bert; Pinart, Mariona; Heude, Barbara; Ewart, Susan; Yao, Jin; Lemonnier, Nathanael; Franco, Oscar H.; Wu, Michael C.; Hofman, Albert; McArdle, Wendy; Van der Vlies, Pieter; Falahi, Fahimeh; Gillman, Matthew W.; Barcellos, Lisa F.; Kumar, Ashish; Wickman, Magnus; Guerra, Stefano; Charles, Marie-Aline; Holloway, John; Auffray, Charles; Tiemeier, Henning W.; Smith, George Davey; Postma, Dirkje; Hivert, Marie-France; Eskenazi, Brenda; Vrijheid, Martine; Arshad, Hasan; Anto, Josep M.; Dehghan, Abbas; Karmaus, Wilfried; Annesi-Maesano, Isabella; Sunyer, Jordi; Ghantous, Akram; Pershagen, Goran; Hollands, Nina; Murphy, Susan K.; DeMeo, Dawn L.; Burchard, Esteban G.; Ladd-Acosta, Christine; Snieder, Harold; Nystad, Wenche; Koppelman, Gerard H.; Relton, Caroline L.; Jaddoe, Vincent W. V.; Wilcox, Allen; Melen, Erik; London, Stephanie J.

2016-01-01

Epigenetic modifications, including DNA methylation, represent a potential mechanism for environmental impacts on human disease. Maternal smoking in pregnancy remains an important public health problem that impacts child health in a myriad of ways and has potential lifelong consequences. The

DNA Methylation in Newborns and Maternal Smoking in Pregnancy: Genome-wide Consortium Meta-analysis

NARCIS (Netherlands)

B.R. Joubert (Bonnie); J.F. Felix (Janine); P. Yousefi (Paul); K.M. Bakulski (Kelly M.); A.C. Just (Allan C.); C. Breton (Carrie); S.E. Reese (Sarah E.); C.A. Markunas (Christina A.); R.C. Richmond (Rebecca C.); C.-J. Xu (Cheng-Jian); L.K. Küpers (Leanne); S.S. Oh (Sam S.); C. Hoyo (Cathrine); O. Gruzieva (Olena); C. Söderhäll (Cilla); L.A. Salas (Lucas A.); N. Baïz (Nour); H. Zhang (Hongmei); J. Lepeule (Johanna); C. Ruiz (Carlos); S. Ligthart (Symen); T. Wang (Tianyuan); J.A. Taylor (Jack A.); L. Duijts (Liesbeth); G.C. Sharp (Gemma C.); S.A. Jankipersadsing (Soesma A.); R.M. Nilsen (Roy M.); A. Vaez (Ahmad); M.D. Fallin (M. Daniele); D. Hu (Donglei); A. Litonjua (Augusto); B.F. Fuemmeler (Bernard F.); K. Huen (Karen); J. Kere (Juha); C.A. Kull (Christian); M.C. Munthe-Kaas (Monica Cheng); U. Gehring (Ulrike); M. Bustamante (Mariona); M.J. Saurel-Coubizolles (Marie José); B.M. Quraishi (Bilal M.); J. Ren (Jie); J. Tost (Jörg); J.R. Gonzalez (Juan R.); M.J. Peters (Marjolein); S.E. Håberg (Siri E); Z. Xu (Zongli); J.B.J. van Meurs (Joyce); T.R. Gaunt (Tom); M. Kerkhof (Marjan); W.E. Corpeleijn (Willemijn); A.P. Feinberg (Andrew P.); C. Eng (Celeste); A.A. Baccarelli (Andrea A.); S.E. Benjamin Neelon (Sara E.); A. Bradman (Asa); S.K. Merid (Simon Kebede); A. Bergström (Anna); Z. Herceg (Zdenko); H. Hernandez-Vargas (Hector); B. Brunekreef (Bert); M. Pinart (Mariona); B. Heude (Barbara); S. Ewart (Susan); J. Yao (Jin); N. Lemonnier (Nathanaël); O.H. Franco (Oscar); M.C. Wu (Michael); A. Hofman (Albert); W.L. McArdle (Wendy); P. van der Vlies (P.); F. Falahi (Fahimeh); M.W. Gillman (Matthew W.); L.F. Barcellos (Lisa); A. Kumar (Ashish); M. Wickman (Magnus); S. Guerra (S.); M.-A. Charles (Marie-Aline); J. Holloway (John); C. Auffray (C.); H.W. Tiemeier (Henning); G.D. Smith; D.S. Postma (Dirkje); M.-F. Hivert (Marie-France); B. Eskenazi (Brenda); M. Vrijheid (Martine); H. Arshad (Hasan); J.M. Antó (Josep M.); A. Dehghan (Abbas); W. Karmaus (Wilfried); I. Annesi-Maesano; J. Sunyer (Jordi); A. Ghantous (Akram); G. Pershagen (Göran); N. Holland (Nina); S.K. Murphy (Susan K.); D.L. Demeo (Dawn L.); E.G. Burchard (Esteban); C. Ladd-Acosta (Christine); H. Snieder (Harold); W. Nystad (Wenche); G.H. Koppelman (Gerard); C.L. Relton (Caroline); V.W.V. Jaddoe (Vincent); A.J. Wilcox (Allen); E. Melén (Erik); S.J. London (Stephanie J.)

2016-01-01

textabstractEpigenetic modifications, including DNA methylation, represent a potential mechanism for environmental impacts on human disease. Maternal smoking in pregnancy remains an important public health problem that impacts child health in a myriad of ways and has potential lifelong consequences.

Isocitrate dehydrogenase 1 and 2 genes mutations and MGMT methylation in gliomas

Directory of Open Access Journals (Sweden)

D. V. Tabakov

2017-01-01

Full Text Available Gliomas are the most common brain tumors. It is difficult to detect them at early stages of disease and there is a few available therapies providing significant improvement in survival. Mutations of isocitrate dehydrogenase 1 and 2 genes (IDH1 and IDH2 play significant role in gliomogenesis, diagnostics and selection of patient therapy. We tested the distribution of IDH1 and IDH2 mutations in gliomas of different histological types and grades of malignancy by DNA melting analysis using our protocol with a sensitivity of 5 %. The results of this assay were confirmed by conventional Sanger sequencing. IDH1/2 mutations were detected in 74 % of lower grade gliomas (II and III, World Health Organization and in 14 % of glioblastomas (IV, World Health Organization. Mutation rate in gliomas with oligodendroglioma component were significantly higher then in other glioma types (р = 0.014. The IDH1 mutations was the most common (79 % of general mutation number. IDH1/2 mutations can induce aberrant gene methylation. Detection of methylation rate of the gene encoding for O6-methylguanine-DNA-methyltransferase (MGMT, predictive biomarker for treatment of gliomas with the alkylating agents, has demonstrated a partial association with IDH1/2 mutations. In 73 % of IDH1/2-mutant tumors MGMT promoter methylation were observed. At the same time IDH1/2 mutations were not revealed in 67 % tumors with MGMT promoter methylation. These results indicate existence of another mechanism of MGMT methylation in gliomas. Our data strong support for necessity of both markers testing when patient therapy is selected.

Relationship between methylation status of vitamin D-related genes, vitamin D levels, and methyl-donor biochemistry

Directory of Open Access Journals (Sweden)

Emma Louise Beckett

2016-12-01

Full Text Available Vitamin D is known for its role in the regulation of gene expression via the vitamin D receptor, a nuclear transcription factor. More recently, a role for vitamin D in regulating DNA methylation has been identified as an additional mechanism of modulation of gene expression. How methylation status influences vitamin D metabolism and response pathways is not yet clear. Therefore, we aimed to assess the relationship between plasma 25-hydroxycholecalciferol (25(OHD and the methylation status of vitamin D metabolism enzyme genes (CYP2R1, CYP27B1 and CYP24A1 and the vitamin D receptor gene (VDR. This analysis was conducted in the context of dietary vitamin D, and background methyl donor related biochemistry, with adjustment for several dietary and lifestyle variables. Percentage methylation at CpG sites was assessed in peripheral blood cells using methylation sensitive and dependent enzymes and qPCR. Standard analytical techniques were used to determine plasma 25(OHD and homocysteine, and serum folate and B12, with the relationship to methylation status assessed using multi-variable regression analysis. CYP2R1 and VDR methylation were found to be independent predictors of plasma 25(OHD, when adjusted for vitamin D intake and other lifestyle variables. CYP24A1 was related to plasma 25(OHD directly, but not in the context of vitamin D intake. Methyl-group donor biochemistry was associated with the methylation status of some genes, but did not alter the relationship between methylation and plasma 25(OHD. Modulation of methylation status of CYP2R1, CYP24A1 and VDR in response to plasma 25(OHD may be part of feedback loops involved in maintaining vitamin D homeostasis, and may explain a portion of the variance in plasma 25(OHD levels in response to intake and sun exposure. Methyl-group donor biochemistry, while a potential independent modulator, did not alter this effect.

Methylation screening of the TGFBI promoter in human lung and prostate cancer by methylation-specific PCR

International Nuclear Information System (INIS)

Shah, Jinesh N; Shao, Genze; Hei, Tom K; Zhao, Yongliang

2008-01-01

Hypermethylation of the TGFBI promoter has been shown to correlate with decreased expression of this gene in human tumor cell lines. In this study, we optimized a methylation-specific polymerase chain reaction (MSP) method and investigated the methylation status of the TGFBI promoter in human lung and prostate cancer specimens. Methylation-specific primers were designed based on the methylation profiles of the TGFBI promoter in human tumor cell lines, and MSP conditions were optimized for accurate and efficient amplification. Genomic DNA was isolated from lung tumors and prostatectomy tissues of prostate cancer patients, bisulfite-converted, and analyzed by MSP. Among 50 lung cancer samples, 44.0% (22/50) harbored methylated CpG sites in the TGFBI promoter. An analysis correlating gene methylation status with clinicopathological cancer features revealed that dense methylation of the TGFBI promoter was associated with a metastatic phenotype, with 42.9% (6/14) of metastatic lung cancer samples demonstrating dense methylation vs. only 5.6% (2/36) of primary lung cancer samples (p < 0.05). Similar to these lung cancer results, 82.0% (41/50) of prostate cancer samples harbored methylated CpG sites in the TGFBI promoter, and dense methylation of the promoter was present in 38.9% (7/18) of prostate cancer samples with the feature of locoregional invasiveness vs. only 19.4% (6/31) of prostate cancer samples without locoregional invasiveness (p < 0.05). Furthermore, promoter hypermethylation correlated with highly reduced expression of the TGFBI gene in human lung and prostate tumor cell lines. We successfully optimized a MSP method for the precise and efficient screening of TGFBI promoter methylation status. Dense methylation of the TGFBI promoter correlated with the extent of TGFBI gene silencing in tumor cell lines and was related to invasiveness of prostate tumors and metastatic status of lung cancer tumors. Thus, TGFBI promoter methylation can be used as a potential

A DNA methylation microarray-based study identifies ERG as a gene commonly methylated in prostate cancer.

Science.gov (United States)

Schwartzman, Jacob; Mongoue-Tchokote, Solange; Gibbs, Angela; Gao, Lina; Corless, Christopher L; Jin, Jennifer; Zarour, Luai; Higano, Celestia; True, Lawrence D; Vessella, Robert L; Wilmot, Beth; Bottomly, Daniel; McWeeney, Shannon K; Bova, G Steven; Partin, Alan W; Mori, Motomi; Alumkal, Joshi

2011-10-01

DNA methylation of promoter regions is a common event in prostate cancer, one of the most common cancers in men worldwide. Because prior reports demonstrating that DNA methylation is important in prostate cancer studied a limited number of genes, we systematically quantified the DNA methylation status of 1505 CpG dinucleotides for 807 genes in 78 paraffin-embedded prostate cancer samples and three normal prostate samples. The ERG gene, commonly repressed in prostate cells in the absence of an oncogenic fusion to the TMPRSS2 gene, was one of the most commonly methylated genes, occurring in 74% of prostate cancer specimens. In an independent group of patient samples, we confirmed that ERG DNA methylation was common, occurring in 57% of specimens, and cancer-specific. The ERG promoter is marked by repressive chromatin marks mediated by polycomb proteins in both normal prostate cells and prostate cancer cells, which may explain ERG's predisposition to DNA methylation and the fact that tumors with ERG DNA methylation were more methylated, in general. These results demonstrate that bead arrays offer a high-throughput method to discover novel genes with promoter DNA methylation such as ERG, whose measurement may improve our ability to more accurately detect prostate cancer.

DNA methylation and memory formation.

Science.gov (United States)

Day, Jeremy J; Sweatt, J David

2010-11-01

Memory formation and storage require long-lasting changes in memory-related neuronal circuits. Recent evidence indicates that DNA methylation may serve as a contributing mechanism in memory formation and storage. These emerging findings suggest a role for an epigenetic mechanism in learning and long-term memory maintenance and raise apparent conundrums and questions. For example, it is unclear how DNA methylation might be reversed during the formation of a memory, how changes in DNA methylation alter neuronal function to promote memory formation, and how DNA methylation patterns differ between neuronal structures to enable both consolidation and storage of memories. Here we evaluate the existing evidence supporting a role for DNA methylation in memory, discuss how DNA methylation may affect genetic and neuronal function to contribute to behavior, propose several future directions for the emerging subfield of neuroepigenetics, and begin to address some of the broader implications of this work.

DNA methylation in metabolic disorders

DEFF Research Database (Denmark)

Barres, Romain; Zierath, Juleen R

2011-01-01

DNA methylation is a major epigenetic modification that controls gene expression in physiologic and pathologic states. Metabolic diseases such as diabetes and obesity are associated with profound alterations in gene expression that are caused by genetic and environmental factors. Recent reports...... have provided evidence that environmental factors at all ages could modify DNA methylation in somatic tissues, which suggests that DNA methylation is a more dynamic process than previously appreciated. Because of the importance of lifestyle factors in metabolic disorders, DNA methylation provides...... a mechanism by which environmental factors, including diet and exercise, can modify genetic predisposition to disease. This article considers the current evidence that defines a role for DNA methylation in metabolic disorders....

Histone Lysine Methylation and Neurodevelopmental Disorders

Directory of Open Access Journals (Sweden)

Jeong-Hoon Kim

2017-06-01

Full Text Available Methylation of several lysine residues of histones is a crucial mechanism for relatively long-term regulation of genomic activity. Recent molecular biological studies have demonstrated that the function of histone methylation is more diverse and complex than previously thought. Moreover, studies using newly available genomics techniques, such as exome sequencing, have identified an increasing number of histone lysine methylation-related genes as intellectual disability-associated genes, which highlights the importance of accurate control of histone methylation during neurogenesis. However, given the functional diversity and complexity of histone methylation within the cell, the study of the molecular basis of histone methylation-related neurodevelopmental disorders is currently still in its infancy. Here, we review the latest studies that revealed the pathological implications of alterations in histone methylation status in the context of various neurodevelopmental disorders and propose possible therapeutic application of epigenetic compounds regulating histone methylation status for the treatment of these diseases.

Avocado and olive oil methyl esters

International Nuclear Information System (INIS)

Knothe, Gerhard

2013-01-01

Biodiesel, the mono-alkyl esters of vegetable oils, animal fats or other triacylglycerol-containing materials and an alternative to conventional petroleum-based diesel fuel, has been derived from a variety of feedstocks. Numerous feedstocks have been investigated as potential biodiesel sources, including commodity oils, however, the methyl esters of avocado and olive oil would likely be suitable as biodiesel fuel. In order to expand the database and comprehensive evaluation of the properties of vegetable oil esters, in this work the fuel-related properties of avocado and olive oil methyl esters, which exhibit similar fatty acid profiles including high oleic acid content, are determined. The cetane numbers of avocado oil methyl esters and olive oil methyl esters are relatively high, determined as 59.2 and 62.5, respectively, due to their elevated content of methyl oleate. Other properties are well within the ranges specified in biodiesel standards. The cloud points of both esters are slightly above 0 °C due to their content of saturated esters, especially methyl palmitate. Overall, avocado and olive oil yield methyl esters with fuel properties comparable to methyl esters from other commodity vegetable oils. The 1 H and 13 C NMR spectra of avocado and olive oil methyl esters are reported. -- Highlights: • Methyl esters of avocado and olive oil meet biodiesel fuel standards. • Provides comparison for methyl esters of other vegetable oils with high oleic content. • Discusses and compares present results with prior literature

Methylated site display (MSD)-AFLP, a sensitive and affordable method for analysis of CpG methylation profiles.

Science.gov (United States)

Aiba, Toshiki; Saito, Toshiyuki; Hayashi, Akiko; Sato, Shinji; Yunokawa, Harunobu; Maruyama, Toru; Fujibuchi, Wataru; Kurita, Hisaka; Tohyama, Chiharu; Ohsako, Seiichiroh

2017-03-09

It has been pointed out that environmental factors or chemicals can cause diseases that are developmental in origin. To detect abnormal epigenetic alterations in DNA methylation, convenient and cost-effective methods are required for such research, in which multiple samples are processed simultaneously. We here present methylated site display (MSD), a unique technique for the preparation of DNA libraries. By combining it with amplified fragment length polymorphism (AFLP) analysis, we developed a new method, MSD-AFLP. Methylated site display libraries consist of only DNAs derived from DNA fragments that are CpG methylated at the 5' end in the original genomic DNA sample. To test the effectiveness of this method, CpG methylation levels in liver, kidney, and hippocampal tissues of mice were compared to examine if MSD-AFLP can detect subtle differences in the levels of tissue-specific differentially methylated CpGs. As a result, many CpG sites suspected to be tissue-specific differentially methylated were detected. Nucleotide sequences adjacent to these methyl-CpG sites were identified and we determined the methylation level by methylation-sensitive restriction endonuclease (MSRE)-PCR analysis to confirm the accuracy of AFLP analysis. The differences of the methylation level among tissues were almost identical among these methods. By MSD-AFLP analysis, we detected many CpGs showing less than 5% statistically significant tissue-specific difference and less than 10% degree of variability. Additionally, MSD-AFLP analysis could be used to identify CpG methylation sites in other organisms including humans. MSD-AFLP analysis can potentially be used to measure slight changes in CpG methylation level. Regarding the remarkable precision, sensitivity, and throughput of MSD-AFLP analysis studies, this method will be advantageous in a variety of epigenetics-based research.

Methylation-sensitive amplified polymorphism-based genome-wide analysis of cytosine methylation profiles in Nicotiana tabacum cultivars.

Science.gov (United States)

Jiao, J; Wu, J; Lv, Z; Sun, C; Gao, L; Yan, X; Cui, L; Tang, Z; Yan, B; Jia, Y

2015-11-26

This study aimed to investigate cytosine methylation profiles in different tobacco (Nicotiana tabacum) cultivars grown in China. Methylation-sensitive amplified polymorphism was used to analyze genome-wide global methylation profiles in four tobacco cultivars (Yunyan 85, NC89, K326, and Yunyan 87). Amplicons with methylated C motifs were cloned by reamplified polymerase chain reaction, sequenced, and analyzed. The results show that geographical location had a greater effect on methylation patterns in the tobacco genome than did sampling time. Analysis of the CG dinucleotide distribution in methylation-sensitive polymorphic restriction fragments suggested that a CpG dinucleotide cluster-enriched area is a possible site of cytosine methylation in the tobacco genome. The sequence alignments of the Nia1 gene (that encodes nitrate reductase) in Yunyan 87 in different regions indicate that a C-T transition might be responsible for the tobacco phenotype. T-C nucleotide replacement might also be responsible for the tobacco phenotype and may be influenced by geographical location.

DNA methylation in sugarcane somaclonal variants assessed through methylation-sensitive amplified polymorphism.

Science.gov (United States)

Francischini, J H M B; Kemper, E L; Costa, J B; Manechini, J R V; Pinto, L R

2017-05-04

Micropropagation is an important tool for large-scale multiplication of plant superior genotypes. However, somaclonal variation is one of the drawbacks of this process. Changes in DNA methylation have been widely reported as one of the main causes of somaclonal variations in plants. In order to investigate the occurrence of changes in the methylation pattern of sugarcane somaclonal variants, the MSAP (methylation-sensitive amplified polymorphism) technique was applied to micro-propagated plantlets sampled at the third subculture phase. The mother plant, in vitro normal plantlets, and in vitro abnormal plantlets (somaclonal variants) of four sugarcane clones were screened against 16 MSAP selective primers for EcoRI/MspI and EcoRI/HpaII restriction enzymes. A total of 1005 and 1200 MSAP-derived markers with polymorphism percentages of 28.36 and 40.67 were obtained for EcoRI/HpaII and EcoRI/MspI restriction enzyme combinations, respectively. The genetic similarity between the mother plant and the somaclonal variants ranged from 0.877 to 0.911 (EcoRI/MspI) and from 0.928 to 0.955 (EcoRI/HpaII). Most of the MASPs among mother plant and micro-propagated plantlets were derived from EcoRI/MspI restriction enzymes suggesting alteration due to gain or loss of internal cytosine methylation. A higher rate of loss of methylation (hypomethylation) than gain of methylation (hypermethylation) was observed in the abnormal in vitro sugarcane plantlets. Although changes in the methylation pattern were also observed in the in vitro normal plantlets, they were lower than those observed for the in vitro abnormal plantlets. The MASP technique proved to be a promising tool to early assessment of genetic fidelity of micro-propagated sugarcane plants.

Analysis of RET promoter CpG island methylation using methylation-specific PCR (MSP), pyrosequencing, and methylation-sensitive high-resolution melting (MS-HRM): impact on stage II colon cancer patient outcome.

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Draht, Muriel X G; Smits, Kim M; Jooste, Valérie; Tournier, Benjamin; Vervoort, Martijn; Ramaekers, Chantal; Chapusot, Caroline; Weijenberg, Matty P; van Engeland, Manon; Melotte, Veerle

2016-01-01

Already since the 1990s, promoter CpG island methylation markers have been considered promising diagnostic, prognostic, and predictive cancer biomarkers. However, so far, only a limited number of DNA methylation markers have been introduced into clinical practice. One reason why the vast majority of methylation markers do not translate into clinical applications is lack of independent validation of methylation markers, often caused by differences in methylation analysis techniques. We recently described RET promoter CpG island methylation as a potential prognostic marker in stage II colorectal cancer (CRC) patients of two independent series. In the current study, we analyzed the RET promoter CpG island methylation of 241 stage II colon cancer patients by direct methylation-specific PCR (MSP), nested-MSP, pyrosequencing, and methylation-sensitive high-resolution melting (MS-HRM). All primers were designed as close as possible to the same genomic region. In order to investigate the effect of different DNA methylation assays on patient outcome, we assessed the clinical sensitivity and specificity as well as the association of RET methylation with overall survival for three and five years of follow-up. Using direct-MSP and nested-MSP, 12.0 % (25/209) and 29.6 % (71/240) of the patients showed RET promoter CpG island methylation. Methylation frequencies detected by pyrosequencing were related to the threshold for positivity that defined RET methylation. Methylation frequencies obtained by pyrosequencing (threshold for positivity at 20 %) and MS-HRM were 13.3 % (32/240) and 13.8 % (33/239), respectively. The pyrosequencing threshold for positivity of 20 % showed the best correlation with MS-HRM and direct-MSP results. Nested-MSP detected RET promoter CpG island methylation in deceased patients with a higher sensitivity (33.1 %) compared to direct-MSP (10.7 %), pyrosequencing (14.4 %), and MS-HRM (15.4 %). While RET methylation frequencies detected by nested

Protection against de novo methylation is instrumental in maintaining parent-of-origin methylation inherited from the gametes.

Science.gov (United States)

Proudhon, Charlotte; Duffié, Rachel; Ajjan, Sophie; Cowley, Michael; Iranzo, Julian; Carbajosa, Guillermo; Saadeh, Heba; Holland, Michelle L; Oakey, Rebecca J; Rakyan, Vardhman K; Schulz, Reiner; Bourc'his, Déborah

2012-09-28

Identifying loci with parental differences in DNA methylation is key to unraveling parent-of-origin phenotypes. By conducting a MeDIP-Seq screen in maternal-methylation free postimplantation mouse embryos (Dnmt3L-/+), we demonstrate that maternal-specific methylation exists very scarcely at midgestation. We reveal two forms of oocyte-specific methylation inheritance: limited to preimplantation, or with longer duration, i.e. maternally imprinted loci. Transient and imprinted maternal germline DMRs (gDMRs) are indistinguishable in gametes and preimplantation embryos, however, de novo methylation of paternal alleles at implantation delineates their fates and acts as a major leveling factor of parent-inherited differences. We characterize two new imprinted gDMRs, at the Cdh15 and AK008011 loci, with tissue-specific imprinting loss, again by paternal methylation gain. Protection against demethylation after fertilization has been emphasized as instrumental in maintaining parent-of-origin methylation inherited from the gametes. Here we provide evidence that protection against de novo methylation acts as an equal major pivot, at implantation and throughout life. Copyright © 2012 Elsevier Inc. All rights reserved.

Structure, function and carcinogenicity of metabolites of methylated and non-methylated polycyclic aromatic hydrocarbons: a comprehensive review.

Science.gov (United States)

Flesher, James W; Lehner, Andreas F

2016-01-01

The Unified Theory of PAH Carcinogenicity accommodates the activities of methylated and non-methylated polycyclic aromatic hydrocarbons (PAHs) and states that substitution of methyl groups on meso-methyl substituted PAHs with hydroxy, acetoxy, chloride, bromide or sulfuric acid ester groups imparts potent cancer producing properties. It incorporates specific predictions from past researchers on the mechanism of carcinogenesis by methyl-substituted hydrocarbons, including (1) requirement for metabolism to an ArCH2X type structure where X is a good leaving group and (2) biological substitution of a meso-methyl group at the most reactive center in non-methylated hydrocarbons. The Theory incorporates strong inferences of Fieser: (1) The mechanism of carcinogenesis involves a specific metabolic substitution of a hydrocarbon at its most reactive center and (2) Metabolic elimination of a carcinogen is a detoxifying process competitive with that of carcinogenesis and occurring by a different mechanism. According to this outlook, chemical or biochemical substitution of a methyl group at the reactive meso-position of non-methylated hydrocarbons is the first step in the mechanism of carcinogenesis for most, if not all, PAHs and the most potent metabolites of PAHs are to be found among the meso methyl-substituted hydrocarbons. Some PAHs and their known or potential metabolites and closely related compounds have been tested in rats for production of sarcomas at the site of subcutaneous injection and the results strongly support the specific predictions of the Unified Theory.

Methylated genes as new cancer biomarkers.

LENUS (Irish Health Repository)

Duffy, M J

2012-02-01

Aberrant hypermethylation of promoter regions in specific genes is a key event in the formation and progression of cancer. In at least some situations, these aberrant alterations occur early in the formation of malignancy and appear to be tumour specific. Multiple reports have suggested that measurement of the methylation status of the promoter regions of specific genes can aid early detection of cancer, determine prognosis and predict therapy responses. Promising DNA methylation biomarkers include the use of methylated GSTP1 for aiding the early diagnosis of prostate cancer, methylated PITX2 for predicting outcome in lymph node-negative breast cancer patients and methylated MGMT in predicting benefit from alkylating agents in patients with glioblastomas. However, prior to clinical utilisation, these findings require validation in prospective clinical studies. Furthermore, assays for measuring gene methylation need to be standardised, simplified and evaluated in external quality assurance programmes. It is concluded that methylated genes have the potential to provide a new generation of cancer biomarkers.

Are clinicopathological features of colorectal cancers with methylation in half of CpG island methylator phenotype panel markers different from those of CpG island methylator phenotype-high colorectal cancers?

Science.gov (United States)

Bae, Jeong Mo; Rhee, Ye-Young; Kim, Kyung Ju; Wen, Xianyu; Song, Young Seok; Cho, Nam-Yun; Kim, Jung Ho; Kang, Gyeong Hoon

2016-01-01

CpG island methylator phenotype (CIMP)-high (CIMP-H) colorectal cancer (CRC) is defined when a tumor shows methylation at greater than or equal to 60% of CIMP panel markers. Although CRCs with methylation at 50% of panel markers are classified as CIMP-low/CIMP-0 tumors, little is known regarding the clinicopathological and molecular features of CRCs with methylation at 4/8 panel markers (4/8 methylated markers) and whether they are akin to CIMP-H or CIMP-low/CIMP-0 CRCs in terms of their clinicopathological or molecular features. A total of 1164 cases of surgically resected CRC were analyzed for their methylation status in 8 CIMP panel markers, and the frequencies of various clinicopathological and molecular features were compared between CRCs with 0/8, 1/8 to 3/8, 4/8, and 5/8 to 8/8 methylated markers. CRCs with 4/8 methylated markers were closer to CRCs with 5/8 to 8/8 methylated markers in terms of sex distribution, mucin production, serration, nodal metastasis, CK7 expression, CK20 loss, and CDX2 loss frequencies and overall survival rate. CRCs with methylation at 4/8 markers were closer to CRCs with 1/8 to 3/8 methylated markers in terms of less frequent right colon location and poor differentiation. CRCs with 4/8 methylated markers showed the shortest overall survival time compared with CRCs with 0/8, 1/8 to 3/8, 4/8, or 5/8 to 8/8 methylated markers. In terms of clinicopathological and molecular features, CRCs with 4/8 methylated markers appeared to be closer to CIMP-H than to CIMP-low/CIMP-0 and would thus be better classified as CIMP-H if the CRCs require classification into either CIMP-H or CIMP-low/CIMP-0. Copyright © 2015 Elsevier Inc. All rights reserved.

Residues and dissipation of kresoxim methyl in apple under field condition.

Science.gov (United States)

Malhat, Farag; Kamel, Essam; Saber, Ayman; Hassan, Ehab; Youssef, Ahmed; Almaz, Monir; Hassan, Ayman; Fayz, Abd El-Salam

2013-09-01

The dissipation and residual levels of kresoxim methyl in apple under field condition were determined by using HPLC-DAD with QuEChERS method. At fortification levels of 0.05, 0.1, 0.5 and 1.0 mg kg(-1) in apple, it was shown that recoveries were ranged from 91.1% to 96.9% with coefficient variation of the method (CV%) for repeatability ranged from 1.27% to 4.77%. The limit of quantification (LOQ) of the method was 0.05 mg kg(-1). The dissipation rates of kresoxim methyl were described by using first-order kinetics and its half-life, as they are ranged from 4.58 to 4.77 days in apple. The terminal residues of kresoxim methyl were below the FAO/WHO maximum residue limit (MRL, 0.2 mg kg(-1)) in apple when measured 14 days after the final application, which suggested that the use of this fungicide was safe for humans. This study would help in providing the basic information for developing regulation to guard a safe use of kresoxim methyl in apple orchard and to prevent health problem from consumers. Copyright © 2013 Elsevier Ltd. All rights reserved.

Methyl jasmonate affects phenolic metabolism and gene expression in blueberry (Vaccinium corymbosum).

Science.gov (United States)

Cocetta, Giacomo; Rossoni, Mara; Gardana, Claudio; Mignani, Ilaria; Ferrante, Antonio; Spinardi, Anna

2015-02-01

Blueberry (Vaccinium corymbosum) is a fruit very much appreciated by consumers for its antioxidant potential and health-promoting traits. Its beneficial potential properties are mainly due to a high content of anthocyanins and their amount can change after elicitation with methyl jasmonate. The aim of this work is to evaluate the changes in expression of several genes, accumulation of phenolic compounds and alterations in antioxidant potential in two different blueberry cultivars ('Duke' and 'Blueray') in response to methyl jasmonate (0.1 mM). Results showed that 9 h after treatment, the expression of phenylalanine ammonium lyase, chalcone synthase and anthocyanidin synthase genes was stimulated more in the 'Blueray' variety. Among the phenols measured an increase was recorded also for epicatechin and anthocyanin concentrations. 'Duke' is a richer sourche of anthocyanins compared to 'Blueray', treatment with methyl jasmonate promoted in 'Blueray' an increase in pigments as well as in the antioxidant potential, especially in fully ripe berries, but treated 'Duke' berries had greater levels, which were not induced by methyl jasmonate treatment. In conclusion, methyl jasmonate was, in some cases, an effective elicitor of phenolic metabolism and gene expression in blueberry, though with different intensity between cultivars. © 2014 Scandinavian Plant Physiology Society.

Omic personality: implications of stable transcript and methylation profiles for personalized medicine.

Science.gov (United States)

Tabassum, Rubina; Sivadas, Ambily; Agrawal, Vartika; Tian, Haozheng; Arafat, Dalia; Gibson, Greg

2015-08-13

Personalized medicine is predicated on the notion that individual biochemical and genomic profiles are relatively constant in times of good health and to some extent predictive of disease or therapeutic response. We report a pilot study quantifying gene expression and methylation profile consistency over time, addressing the reasons for individual uniqueness, and its relation to N = 1 phenotypes. Whole blood samples from four African American women, four Caucasian women, and four Caucasian men drawn from the Atlanta Center for Health Discovery and Well Being study at three successive 6-month intervals were profiled by RNA-Seq, miRNA-Seq, and Illumina Methylation 450 K arrays. Standard regression approaches were used to evaluate the proportion of variance for each type of omic measure among individuals, and to quantify correlations among measures and with clinical attributes related to wellness. Longitudinal omic profiles were in general highly consistent over time, with an average of 67 % variance in transcript abundance, 42 % in CpG methylation level (but 88 % for the most differentiated CpG per gene), and 50 % in miRNA abundance among individuals, which are all comparable to 74 % variance among individuals for 74 clinical traits. One third of the variance could be attributed to differential blood cell type abundance, which was also fairly stable over time, and a lesser amount to expression quantitative trait loci (eQTL) effects. Seven conserved axes of covariance that capture diverse aspects of immune function explained over half of the variance. These axes also explained a considerable proportion of individually extreme transcript abundance, namely approximately 100 genes that were significantly up-regulated or down-regulated in each person and were in some cases enriched for relevant gene activities that plausibly associate with clinical attributes. A similar fraction of genes had individually divergent methylation levels, but these did not overlap with the

How does methylation suppress the electron-induced decomposition of 1-methyl-nitroimidazoles?

Science.gov (United States)

Kossoski, F.; Varella, M. T. do N.

2017-10-01

The efficient decomposition of nitroimidazoles (NIs) by low energy electrons is believed to underlie their radiosensitizing properties. Recent dissociative electron attachment (DEA) measurements showed that methylation at the N1 site unexpectedly suppresses the electron-induced reactions in 4(5)-NI. We report theoretical results that provide a clear interpretation of that astounding finding. Around 1.5 eV, DEA reactions into several fragments are initiated by a π* resonance, not considered in previous studies. The autoionization lifetime of this anion state, which limits the predissociation dynamics, is considerably shorter in the methylated species, thereby suppressing the DEA signals. On the other hand, the lifetime of the π* resonance located around 3 eV is less affected by methylation, which explains why DEA is still observed at these energies. Our results demonstrate how even a simple methylation can significantly modify the probabilities for DEA reactions, which may be significant for NI-based cancer therapy.

Dissociation dynamics of methylal

Energy Technology Data Exchange (ETDEWEB)

Beaud, P; Frey, H -M; Gerber, T; Mischler, B; Radi, P P; Tzannis, A -P [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1999-08-01

The dissociation of methylal is investigated using mass spectrometry, combined with a pyrolytic radical source and femtosecond pump probe experiments. Based on preliminary results two reaction paths of methylal dissociation are proposed and discussed. (author) 4 fig., 3 refs.

DNA methylation changes detected by methylation-sensitive amplified polymorphism in two contrasting rice genotypes under salt stress.

Science.gov (United States)

Wang, Wensheng; Zhao, Xiuqin; Pan, Yajiao; Zhu, Linghua; Fu, Binying; Li, Zhikang

2011-09-20

DNA methylation, one of the most important epigenetic phenomena, plays a vital role in tuning gene expression during plant development as well as in response to environmental stimuli. In the present study, a methylation-sensitive amplified polymorphism (MSAP) analysis was performed to profile DNA methylation changes in two contrasting rice genotypes under salt stress. Consistent with visibly different phenotypes in response to salt stress, epigenetic markers classified as stable inter-cultivar DNA methylation differences were determined between salt-tolerant FL478 and salt-sensitive IR29. In addition, most tissue-specific DNA methylation loci were conserved, while many of the growth stage-dependent DNA methylation loci were dynamic between the two genotypes. Strikingly, salt stress induced a decrease in DNA methylation specifically in roots at the seedling stage that was more profound in IR29 than in the FL478. This result may indicate that demethylation of genes is an active epigenetic response to salt stress in roots at the seedling stage, and helps to further elucidate the implications of DNA methylation in crop growth and development. Copyright © 2011. Published by Elsevier Ltd.

MTHFR methylation moderates the impact of smoking on DNA methylation at AHRR for African American young adults.

Science.gov (United States)

Beach, Steven R H; Lei, Man Kit; Ong, Mei Ling; Brody, Gene H; Dogan, Meeshanthini V; Philibert, Robert A

2017-09-01

Smoking has been shown to have a large, reliable, and rapid effect on demethylation of AHRR, particularly at cg05575921, suggesting that methylation may be used as an index of cigarette consumption. Because the availability of methyl donors may also influence the degree of demethylation in response to smoking, factors that affect the activity of methylene tetrahydrofolate reductase (MTHFR), a key regulator of methyl group availability, may be of interest. In the current investigation, we examined the extent to which individual differences in methylation of MTHFR moderated the association between smoking and demethylation at cg05575921 as well as at other loci on AHRR associated with a main effect of smoking. Using a discovery sample (AIM, N = 293), and a confirmatory sample (SHAPE, N = 368) of young adult African Americans, degree of methylation of loci in the first exon of MTHFR was associated with amplification of the association between smoking and AHRR demethylation at cg05575921. However, genetic variation at a commonly studied MTHFR variant, C677T, did not influence cg05575921 methylation. The significant interaction between MTHFR methylation and the smoking-induced response at cg05575921 suggests a role for individual differences in methyl cycle regulation in understanding the effects of cigarette consumption on genome wide DNA methylation. © 2017 Wiley Periodicals, Inc.

Synthesis of [methyl-{sup 14}C]crotonobetaine from DL-[methyl-{sup 14}C]carnitine

Energy Technology Data Exchange (ETDEWEB)

Loester, H.; Seim, H. [Leipzig Univ. (Germany). Inst. of Clinical Chemistry and Pathobiochemistry

1996-02-01

The causes of carnitine deficiency syndromes are not completely understood, but decomposition of L-carnitine in vivo is likely to be involved. Carnitine is metabolized to {gamma}-butyrobetaine, and crotonobetaine is probably an intermediate in this pathway. To validate experimentally the precursor-product relationship between the three physiologically occuring {gamma}-betaines - L-carnitine, crotonobetaine, {gamma}-butyrobetaine - labelling with stable or radioactive isotopes became necessary. Methyl-labelled carnitine isomers (L(-)-, D(+)- or DL-) or {gamma}-butyrobetaine can be easily synthesized by methylation of 4-amino-3-hydroxybutyric acid isomers or 4-aminobutyric acid, respectively. Because of problems with the 4-aminocrotonic acid, we synthesized labelled crotonbetaine from labelled carnitine. Thus, DL-[methyl-{sup 14}C]carnitine was dehydrated by reaction with concentrated sulfuric acid. After removal of the latter the products were separated and purified by ion exchange chromatography on DOWEX 50 WX8 (200 - 400 mesh) and gradient elution with hydrochloric acid. In addition to the labelled main product [methyl-{sup 14}C]crotonobetaine (yield about 50 %), [methyl-{sup 14}C]glycine betaine and [methyl-{sup 14}C]acetonyl-trimethylammonium (ATMA) were formed. The end products were identified by combined thin layer chromatography/autoradiography and quantified by liquid scintillation counting. (Author).

Factors Affecting Arsenic Methylation in Arsenic-Exposed Humans: A Systematic Review and Meta-Analysis.

Science.gov (United States)

Shen, Hui; Niu, Qiang; Xu, Mengchuan; Rui, Dongsheng; Xu, Shangzhi; Feng, Gangling; Ding, Yusong; Li, Shugang; Jing, Mingxia

2016-02-06

Chronic arsenic exposure is a critical public health issue in many countries. The metabolism of arsenic in vivo is complicated because it can be influenced by many factors. In the present meta-analysis, two researchers independently searched electronic databases, including the Cochrane Library, PubMed, Springer, Embase, and China National Knowledge Infrastructure, to analyze factors influencing arsenic methylation. The concentrations of the following arsenic metabolites increase (piAs), monomethyl arsenic (MMA), dimethyl arsenic (DMA), and total arsenic. Additionally, the percentages of iAs (standard mean difference (SMD): 1.00; 95% confidence interval (CI): 0.60-1.40; p< 0.00001) and MMA (SMD: 0.49; 95% CI: 0.21-0.77; p = 0.0006) also increase, while the percentage of DMA (SMD: -0.57; 95% CI: -0.80--0.31; p< 0.0001), primary methylation index (SMD: -0.57; 95% CI: -0.94--0.20; p = 0.002), and secondary methylation index (SMD: -0.27; 95% CI: -0.46--0.90; p = 0.004) decrease. Smoking, drinking, and older age can reduce arsenic methylation, and arsenic methylation is more efficient in women than in men. The results of this analysis may provide information regarding the role of arsenic oxidative methylation in the arsenic poisoning process.

Process for the production of methyl methacrylate

NARCIS (Netherlands)

Eastham, G.R.; Johnson, D.W.; Straathof, A.J.J.; Fraaije, Marco; Winter, Remko

2015-01-01

A process of producing methyl methacrylate or derivatives thereof is described. The process includes the steps of; (i) converting 2-butanone to methyl propionate using a Baeyer-Villiger monooxygenase, and (ii) treating the methyl propionate produced to obtain methyl methacrylate or derivatives

Methylation patterns in marginal zone lymphoma.

Science.gov (United States)

Arribas, Alberto J; Bertoni, Francesco

Promoter DNA methylation is a major regulator of gene expression and transcription. The identification of methylation changes is important for understanding disease pathogenesis, for identifying prognostic markers and can drive novel therapeutic approaches. In this review we summarize the current knowledge regarding DNA methylation in MALT lymphoma, splenic marginal zone lymphoma, nodal marginal zone lymphoma. Despite important differences in the study design for different publications and the existence of a sole large and genome-wide methylation study for splenic marginal zone lymphoma, it is clear that DNA methylation plays an important role in marginal zone lymphomas, in which it contributes to the inactivation of tumor suppressors but also to the expression of genes sustaining tumor cell survival and proliferation. Existing preclinical data provide the rationale to target the methylation machinery in these disorders. Copyright © 2016 Elsevier Ltd. All rights reserved.

Isolation of the opdE gene that encodes for a new hydrolase of Enterobacter sp. capable of degrading organophosphorus pesticides.

Science.gov (United States)

Chino-Flores, Concepción; Dantán-González, Edgar; Vázquez-Ramos, Alejandra; Tinoco-Valencia, Raunel; Díaz-Méndez, Rafael; Sánchez-Salinas, Enrique; Castrejón-Godínez, Maria Luisa; Ramos-Quintana, Fernando; Ortiz-Hernández, Maria Laura

2012-06-01

Microbial enzymes that can hydrolyze organophosphorus compounds have been isolated, identified and characterized from different microbial species in order to use them in biodegradation of organophosphorus compounds. We isolated a bacterial strain Cons002 from an agricultural soil bacterial consortium, which can hydrolyze methyl-parathion (MP) and other organophosphate pesticides. HPLC analysis showed that strain Cons002 is capable of degrading pesticides MP, parathion and phorate. Pulsed-field gel electrophoresis and 16S rRNA amplification were performed for strain characterization and identification, respectively, showing that the strain Cons002 is related to the genus Enterobacter sp. which has a single chromosome of 4.6 Mb and has no plasmids. Genomic library was constructed from DNA of Enterobacter sp. Cons002. A gene called opdE (Organophosphate Degradation from Enterobacter) consists of 753 bp and encodes a protein of 25 kDa, which was isolated using activity methods. This gene opdE had no similarity to any genes reported to degrade organophosphates. When kanamycin-resistance cassette was placed in the gene opdE, hydrolase activity was suppressed and Enterobacter sp. Cons002 had no growth with MP as a nutrients source.

Improved Cholinergic Transmission is Detrimental to Behavioural Plasticity in Honeybees (Apis mellifera

Directory of Open Access Journals (Sweden)

Shao-Wu Zhang

2012-10-01

Full Text Available Unravelling the role of neuromessenger processes in learning and memory has long interested researchers. We investigated the effects of an acetylcholinesterase blocker, Methyl Parathion (MeP, on honeybee learning. We used visual and olfactory tasks to test whether MeP had a detrimental effect on the acquisition of new knowledge when this new knowledge contradicts previously acquired one. Our results indicate that treatment with MeP prior to conditioning was significantly detrimental to the acquisition of incongruous (but not irrelevant or congruous new knowledge due to improved recall. The neurobiological and ecotoxicological consequences of these results are discussed.

Rapid analysis of heterogeneously methylated DNA using digital methylation-sensitive high resolution melting: application to the CDKN2B (p15) gene

DEFF Research Database (Denmark)

Candiloro, Ida Lm; Mikeska, Thomas; Hokland, Peter

2008-01-01

ABSTRACT: BACKGROUND: Methylation-sensitive high resolution melting (MS-HRM) methodology is able to recognise heterogeneously methylated sequences by their characteristic melting profiles. To further analyse heterogeneously methylated sequences, we adopted a digital approach to MS-HRM (dMS-HRM) t......ABSTRACT: BACKGROUND: Methylation-sensitive high resolution melting (MS-HRM) methodology is able to recognise heterogeneously methylated sequences by their characteristic melting profiles. To further analyse heterogeneously methylated sequences, we adopted a digital approach to MS-HRM (d......MS-HRM) that involves the amplification of single templates after limiting dilution to quantify and to determine the degree of methylation. We used this approach to study methylation of the CDKN2B (p15) cell cycle progression inhibitor gene which is inactivated by DNA methylation in haematological malignancies...... the methylated alleles and assess the degree of methylation. Direct sequencing of selected dMS-HRM products was used to determine the exact DNA methylation pattern and confirmed the degree of methylation estimated by dMS-HRM. CONCLUSION: dMS-HRM is a powerful technique for the analysis of methylation in CDKN2B...

Inductive effect of methyl group in a series of methylated indoles: A ...

Indian Academy of Sciences (India)

Vol. 125, No. 4, July 2013, pp. 905–912. c Indian Academy of Sciences. Inductive effect of methyl group in a series of methylated indoles: A graph theoretical analysis in the light of density functional theory and correlation with experimental charge transfer transition energies. AMIT S TIWARYa,∗ and ASOK K MUKHERJEEb.

Methylation-Specific PCR Unraveled

Directory of Open Access Journals (Sweden)

Sarah Derks

2004-01-01

Full Text Available Methylation‐specific PCR (MSP is a simple, quick and cost‐effective method to analyze the DNA methylation status of virtually any group of CpG sites within a CpG island. The technique comprises two parts: (1 sodium bisulfite conversion of unmethylated cytosine's to uracil under conditions whereby methylated cytosines remains unchanged and (2 detection of the bisulfite induced sequence differences by PCR using specific primer sets for both unmethylated and methylated DNA. This review discusses the critical parameters of MSP and presents an overview of the available MSP variants and the (clinical applications.

Synthesis of 14C-labelled α-methyl tyrosine

International Nuclear Information System (INIS)

Rajagopal, S.; Venkatachalam, T.K.; Conway, T.; Diksic, M.

1992-01-01

A new route for the preparation of radioactively labelled α-methyl L-tyrosine is described. The labelling at the α position has been successfully achieved with 14 C-, 11 C- (very preliminary, unpublished), and 3 H-labelled methyl iodide. A detailed report on 14 C-labelling at the α position and the hydrolysis of 4-methoxy α-methyl phenylalanine is presented. The alkylation proceeds via the methylation of the carbanion of N-benzylidene 4-methoxy phenylalanine methyl ester 2. Hydrolysis of 4-O methyl tyrosine to tyrosine by HBr and HI were analysed and used in the optimization of the hydrolysis conditions of 4. Enantiomeric purity of the isolated L-isomer has been found to be 99% as judged by HPLC. Pseudo first-order rate constant for the hydrolysis of 14 C-labelled α-methyl 4-methoxy phenyl alanine methyl ester was determined. Preliminary findings of the 3 H- and 11 C-radiolabelled α-methyl tyrosine (methyl labelled) are also mentioned. For the first time it was shown that α-methyl D,L-tyrosine can be separated into enantiomerically pure α-methyl D- and L-tyrosine using a CHIRALPAK WH column. (author)

Liberation of methyl acrylate from metallalactone complexes via M-O ring opening (M = Ni, Pd) with methylation agents

KAUST Repository

Lee, S. Y Tina; Ghani, Amylia Abdul; D'Elia, Valerio; Cokoja, Mirza; Herrmann, Wolfgang A.; Basset, Jean-Marie; Kü hn, Fritz

2013-01-01

Ring opening of various nickela- and palladalactones induced by the cleavage of the M-O bond by methyl trifluoromethanesulfonate (MeOTf) and methyl iodide (MeI) is examined. Experimental evidence supports the mechanism of ring opening by the alkylating agent followed by β-H elimination leading to methyl acrylate and a metal-hydride species. MeOTf shows by far higher efficiency in the lactone ring opening than any other methylating agent including the previously reported methyl iodide. © 2013 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.

Genome-wide DNA methylation in 1-year-old infants of mothers with major depressive disorder.

Science.gov (United States)

Cicchetti, Dante; Hetzel, Susan; Rogosch, Fred A; Handley, Elizabeth D; Toth, Sheree L

2016-11-01

A genome-wide methylation study was conducted among a sample of 114 infants (M age = 13.2 months, SD = 1.08) of low-income urban women with (n = 73) and without (n = 41) major depressive disorder. The Illumina HumanMethylation450 BeadChip array with a GenomeStudio Methylation Module and Illumina Custom model were used to conduct differential methylation analyses. Using the 5.0 × 10-7 p value, 2,119 loci were found to be significantly different between infants of depressed and nondepressed mothers. Infants of depressed mothers had greater methylation at low methylation sites (0%-29%) compared to infants of nondepressed mothers. At high levels of methylation (70%-100%), the infants of depressed mothers were predominantly hypomethylated. The mean difference in methylation between the infants of depressed and infants of nondepressed mothers was 5.23%. Disease by biomarker analyses were also conducted using GeneGo MetaCore Software. The results indicated significant cancer-related differences in biomarker networks such as prostatic neoplasms, ovarian and breast neoplasms, and colonic neoplasms. The results of a process networks analysis indicated significant differences in process networks associated with neuronal development and central nervous system functioning, as well as cardiac development between infants of depressed and nondepressed mothers. These findings indicate that early in development, infants of mothers with major depressive disorder evince epigenetic differences relative to infants of well mothers that suggest risk for later adverse health outcomes.

Methylation pathways in schizophrenia

International Nuclear Information System (INIS)

Sargent, T.W. III.

1982-01-01

Research on the biochemical causes of human psychosis concentrates on investigating whether schizophremia is linked to abnormalities in the metabolism of methyl carbon groups in the body. The metabolism of C-14 labeled methyl groups in methionine is studied in animals, normal subjects and patient volunteers

Simultaneous Determination of Salicylic Acid, Jasmonic Acid, Methyl Salicylate, and Methyl Jasmonate from Ulmus pumila Leaves by GC-MS

Directory of Open Access Journals (Sweden)

Zhi-hong Huang

2015-01-01

Full Text Available Salicylic acid, jasmonic acid, methyl salicylate, and methyl jasmonate are important phytohormones and defensive signaling compounds, so it is of great importance to determine their levels rapidly and accurately. The study uses Ulmus pumila leaves infected by Tetraneura akinire Sasaki at different stages as materials; after extraction with 80% methanol and ethyl acetate and purification with primary secondary amine (PSA and graphitized carbon blacks (GCB, the contents of signal compounds salicylic acid, jasmonic acid, methyl salicylate, and methyl jasmonate were determined by GC-MS. The results showed that the level of salicylic acid, jasmonic acid, methyl salicylate, and methyl jasmonate increased remarkably in U. pumila once infected by T. akinire Sasaki, but the maximums of these four compounds occurred at different times. Salicylic acid level reached the highest at the early stage, and jasmonic acid level went to the maximum in the middle stage; by contrast, change of content of methyl salicylate and methyl jasmonate was the quite opposite.

Simultaneous Determination of Salicylic Acid, Jasmonic Acid, Methyl Salicylate, and Methyl Jasmonate from Ulmus pumila Leaves by GC-MS.

Science.gov (United States)

Huang, Zhi-Hong; Wang, Zhi-Li; Shi, Bao-Lin; Wei, Dong; Chen, Jian-Xin; Wang, Su-Li; Gao, Bao-Jia

2015-01-01

Salicylic acid, jasmonic acid, methyl salicylate, and methyl jasmonate are important phytohormones and defensive signaling compounds, so it is of great importance to determine their levels rapidly and accurately. The study uses Ulmus pumila leaves infected by Tetraneura akinire Sasaki at different stages as materials; after extraction with 80% methanol and ethyl acetate and purification with primary secondary amine (PSA) and graphitized carbon blacks (GCB), the contents of signal compounds salicylic acid, jasmonic acid, methyl salicylate, and methyl jasmonate were determined by GC-MS. The results showed that the level of salicylic acid, jasmonic acid, methyl salicylate, and methyl jasmonate increased remarkably in U. pumila once infected by T. akinire Sasaki, but the maximums of these four compounds occurred at different times. Salicylic acid level reached the highest at the early stage, and jasmonic acid level went to the maximum in the middle stage; by contrast, change of content of methyl salicylate and methyl jasmonate was the quite opposite.

Synthesis of DL-adrenaline (methyl C{sup 14}) (1961); Synthese de la DL-adrenaline (methyle {sup 14}C) (1961)

Energy Technology Data Exchange (ETDEWEB)

Pichat, L; Audinot, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

The sodium derivative of 5-3-4 dibenzyl oxyphenyl 2-oxazolidinone reacted with methyl iodide {sup 14}C, in stoichiometric quantity, gives rise to the corresponding N-methyl {sup 14}C derivative. The oxazolidinone ring is opened by concentrated hydrochloric acid and the benzyl groups removed by catalytic hydrogenolysis. Adrenaline methyl {sup 14}C is then purified on Dowex 50 X-12 exchange resin. Overall-yield is 45 per cent based upon methyl iodide {sup 14}C. (author) [French] Le derive sode de la (dibenzyloxy-3-4-phenyl)-5 oxazolidinone-2 traite par l'iodure de methyle {sup 14}C, en proportion stoechiometrique, fournit le derive N-methyle {sup 14}C correspondant. Apres ouverture du cycle oxazolidinone par HCL concentre et debenzylation par hydrogenation catalytique, on purifie l'adrenaline (methyle {sup 14}C) par chromatographie sur resine echangeuse Dowex 50 X-12. Le rendement est de 45 pour cent par rapport a l'iodure de methyle {sup 14}C. (auteurs)

Synthesis of DL-adrenaline (methyl C{sup 14}) (1961); Synthese de la DL-adrenaline (methyle {sup 14}C) (1961)

Energy Technology Data Exchange (ETDEWEB)

Pichat, L.; Audinot, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

The sodium derivative of 5-3-4 dibenzyl oxyphenyl 2-oxazolidinone reacted with methyl iodide {sup 14}C, in stoichiometric quantity, gives rise to the corresponding N-methyl {sup 14}C derivative. The oxazolidinone ring is opened by concentrated hydrochloric acid and the benzyl groups removed by catalytic hydrogenolysis. Adrenaline methyl {sup 14}C is then purified on Dowex 50 X-12 exchange resin. Overall-yield is 45 per cent based upon methyl iodide {sup 14}C. (author) [French] Le derive sode de la (dibenzyloxy-3-4-phenyl)-5 oxazolidinone-2 traite par l'iodure de methyle {sup 14}C, en proportion stoechiometrique, fournit le derive N-methyle {sup 14}C correspondant. Apres ouverture du cycle oxazolidinone par HCL concentre et debenzylation par hydrogenation catalytique, on purifie l'adrenaline (methyle {sup 14}C) par chromatographie sur resine echangeuse Dowex 50 X-12. Le rendement est de 45 pour cent par rapport a l'iodure de methyle {sup 14}C. (auteurs)

Transgenerational epigenetics: Inheritance of global cytosine methylation and methylation-related epigenetic markers in the shrub Lavandula latifolia.

Science.gov (United States)

Herrera, Carlos M; Alonso, Conchita; Medrano, Mónica; Pérez, Ricardo; Bazaga, Pilar

2018-04-01

The ecological and evolutionary significance of natural epigenetic variation (i.e., not based on DNA sequence variants) variation will depend critically on whether epigenetic states are transmitted from parents to offspring, but little is known on epigenetic inheritance in nonmodel plants. We present a quantitative analysis of transgenerational transmission of global DNA cytosine methylation (= proportion of all genomic cytosines that are methylated) and individual epigenetic markers (= methylation status of anonymous MSAP markers) in the shrub Lavandula latifolia. Methods based on parent-offspring correlations and parental variance component estimation were applied to epigenetic features of field-growing plants ('maternal parents') and greenhouse-grown progenies. Transmission of genetic markers (AFLP) was also assessed for reference. Maternal parents differed significantly in global DNA cytosine methylation (range = 21.7-36.7%). Greenhouse-grown maternal families differed significantly in global methylation, and their differences were significantly related to maternal origin. Methylation-sensitive amplified polymorphism (MSAP) markers exhibited significant transgenerational transmission, as denoted by significant maternal variance component of marker scores in greenhouse families and significant mother-offspring correlations of marker scores. Although transmission-related measurements for global methylation and MSAP markers were quantitatively lower than those for AFLP markers taken as reference, this study has revealed extensive transgenerational transmission of genome-wide global cytosine methylation and anonymous epigenetic markers in L. latifolia. Similarity of results for global cytosine methylation and epigenetic markers lends robustness to this conclusion, and stresses the value of considering both types of information in epigenetic studies of nonmodel plants. © 2018 Botanical Society of America.

Analysis of DNA methylation of perennial ryegrass under drought using the methylation-sensitive amplification polymorphism (MSAP) technique.

Science.gov (United States)

Tang, Xiao-Mei; Tao, Xiang; Wang, Yan; Ma, Dong-Wei; Li, Dan; Yang, Hong; Ma, Xin-Rong

2014-12-01

Perennial ryegrass (Lolium perenne), an excellent grass for forage and turf, is widespread in temperate regions. Drought is an important factor that limits its growth, distribution, and yield. DNA methylation affects gene expression and plays an important role in adaptation to adverse environments. In this study, the DNA methylation changes in perennial ryegrass under drought stress were assessed using methylation-sensitive amplified polymorphism (MSAP). After 15 days of drought stress treatment, the plant height was less than half of the control, and the leaves were smaller and darker. Genome-wide, a total of 652 CCGG sites were detected by MSAP. The total methylation level was 57.67 and 47.39 % in the control and drought treatment, respectively, indicating a decrease of 10.28 % due to drought exposure. Fifteen differentially displayed DNA fragments in MSAP profiles were cloned for sequencing analysis. The results showed that most of the genes involved in stress responses. The relative expression levels revealed that three demethylated fragments were up-regulated. The expression of a predicted retrotransposon increased significantly, changing from hypermethylation to non-methylation. Although the extent of methylation in two other genes decreased, the sites of methylation remained, and the expression increased only slightly. All of these results suggested that drought stress decreased the total DNA methylation level in perennial ryegrass and demethylation up-regulated related gene expressions and that the extent of methylation was negatively correlated with expression. Overall, the induced epigenetic changes in genome probably are an important regulatory mechanism for acclimating perennial ryegrass to drought and possibly other environmental stresses.

Microwave-assisted pyrolysis of methyl ricinoleate for continuous production of undecylenic acid methyl ester (UAME).

Science.gov (United States)

Nie, Yong; Duan, Ying; Gong, Ruchao; Yu, Shangzhi; Lu, Meizhen; Yu, Fengwen; Ji, Jianbing

2015-06-01

Undecylenic acid methyl ester (UAME) was continuously produced from methyl ricinoleate using a microwave-assisted pyrolysis system with atomization feeding. The UAME yield of 77 wt.% was obtained at 500°C using SiC as the microwave absorbent and heating medium. The methyl ricinoleate conversion and UAME yield from microwave-assisted pyrolysis process were higher than those from conventional pyrolysis. The effect of temperature on the pyrolysis process was also investigated. The methyl ricinoleate conversion increased but the cracking liquid yield decreased when the temperature increased from 460°C to 560°C. The maximum UAME yield was obtained at the temperature of 500°C. Copyright © 2015 Elsevier Ltd. All rights reserved.

Quantitative DNA methylation analyses reveal stage dependent DNA methylation and association to clinico-pathological factors in breast tumors

International Nuclear Information System (INIS)

Klajic, Jovana; Tost, Jörg; Kristensen, Vessela N; Fleischer, Thomas; Dejeux, Emelyne; Edvardsen, Hege; Warnberg, Fredrik; Bukholm, Ida; Lønning, Per Eystein; Solvang, Hiroko; Børresen-Dale, Anne-Lise

2013-01-01

Aberrant DNA methylation of regulatory genes has frequently been found in human breast cancers and correlated to clinical outcome. In the present study we investigate stage specific changes in the DNA methylation patterns in order to identify valuable markers to understand how these changes affect breast cancer progression. Quantitative DNA methylation analyses of 12 candidate genes ABCB1, BRCCA1, CDKN2A, ESR1, GSTP1, IGF2, MGMT, HMLH1, PPP2R2B, PTEN, RASSF1A and FOXC1 was performed by pyrosequencing a series of 238 breast cancer tissue samples from DCIS to invasive tumors stage I to IV. Significant differences in methylation levels between the DCIS and invasive stage II tumors were observed for six genes RASSF1A, CDKN2A, MGMT, ABCB1, GSTP1 and FOXC1. RASSF1A, ABCB1 and GSTP1 showed significantly higher methylation levels in late stage compared to the early stage breast carcinoma. Z-score analysis revealed significantly lower methylation levels in DCIS and stage I tumors compared with stage II, III and IV tumors. Methylation levels of PTEN, PPP2R2B, FOXC1, ABCB1 and BRCA1 were lower in tumors harboring TP53 mutations then in tumors with wild type TP53. Z-score analysis showed that TP53 mutated tumors had significantly lower overall methylation levels compared to tumors with wild type TP53. Methylation levels of RASSF1A, PPP2R2B, GSTP1 and FOXC1 were higher in ER positive vs. ER negative tumors and methylation levels of PTEN and CDKN2A were higher in HER2 positive vs. HER2 negative tumors. Z-score analysis also showed that HER2 positive tumors had significantly higher z-scores of methylation compared to the HER2 negative tumors. Univariate survival analysis identifies methylation status of PPP2R2B as significant predictor of overall survival and breast cancer specific survival. In the present study we report that the level of aberrant DNA methylation is higher in late stage compared with early stage of invasive breast cancers and DCIS for genes mentioned above

The ectopic expression of a pectin methyl esterase inhibitor increases pectin methyl esterification and limits fungal diseases in wheat.

Science.gov (United States)

Volpi, Chiara; Janni, Michela; Lionetti, Vincenzo; Bellincampi, Daniela; Favaron, Francesco; D'Ovidio, Renato

2011-09-01

Cell wall pectin methyl esterification can influence plant resistance because highly methyl-esterified pectin can be less susceptible to the hydrolysis by pectic enzymes such as fungal endopolygalacturonases (PG). Pectin is secreted into the cell wall in a highly methyl-esterified form and, here, is de-methyl esterified by pectin methyl esterase (PME). The activity of PME is controlled by specific protein inhibitors called PMEI; consequently, an increased inhibition of PME by PMEI might modify the pectin methyl esterification. In order to test the possibility of improving wheat resistance by modifying the methyl esterification of pectin cell wall, we have produced durum wheat transgenic lines expressing the PMEI from Actinidia chinensis (AcPMEI). The expression of AcPMEI endows wheat with a reduced endogenous PME activity, and transgenic lines expressing a high level of the inhibitor showed a significant increase in the degree of methyl esterification. These lines showed a significant reduction of disease symptoms caused by the fungal pathogens Bipolaris sorokiniana or Fusarium graminearum. This increased resistance was related to the impaired ability of these fungal pathogens to grow on methyl-esterified pectin and to a reduced activity of the fungal PG to hydrolyze methyl-esterified pectin. In addition to their importance for wheat improvement, these results highlight the primary role of pectin despite its low content in the wheat cell wall.

Association of oxidative stress with arsenic methylation in chronic arsenic-exposed children and adults

International Nuclear Information System (INIS)

Xu Yuanyuan; Wang Yi; Zheng Quanmei; Li Xin; Li Bing; Jin Yaping; Sun Xiance; Sun Guifan

2008-01-01

Though oxidative stress is recognized as an important pathogenic mechanism of arsenic, and arsenic methylation capacity is suggested to be highly involved in arsenic-related diseases, the association of arsenic methylation capacity with arsenic-induced oxidative stress remains unclear. To explore oxidative stress and its association with arsenic methylation, cross-sectional studies were conducted among 208 high and 59 low arsenic-exposed subjects. Levels of urinary arsenic species [inorganic arsenic (iAs), monomethylated arsenic (MMA) and dimethylated arsenic (DMA)] were determined by hydride generation atomic absorption spectrometry. Proportions of urinary arsenic species, the first methylation ratio (FMR) and the secondary methylation ratio (SMR) were used as indicators for arsenic methylation capacity. Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) concentrations were analyzed by enzyme-linked immunosorbent assay kits. Reduced glutathione (GSH) levels and superoxide dismutase (SOD) activity in whole blood were determined to reflect anti-oxidative status. The high arsenic-exposed children and adults were significantly increased in urinary 8-OHdG concentrations but decreased in blood GSH levels compared with the low exposed children and adults. In multiple linear regression models, blood GSH levels and urinary 8-OHdG concentrations of arsenic-exposed children and adults showed strong associations with the levels of urinary arsenic species. Arsenic-exposed subjects in the lower and the upper quartiles of proportions of urinary arsenic species, FMR or SMR were significantly different in urinary 8-OHdG, blood GSH and SOD. The associations of arsenic methylation capacity with 8-OHdG, GSH and SOD were also observed in multivariate regression analyses. These results may provide linkage between arsenic methylation capacity and oxidative stress in humans and suggest that adverse health effects induced by arsenic are related to arsenic methylation through oxidative stress

Cytosine methylation at CpCpG sites triggers accumulation of non-CpG methylation in gene bodies

OpenAIRE

Zabet, NR; Catoni, Marco; Prischi, F; Paszkowski, Jerzy Waclaw

2017-01-01

Methylation of cytosine is an epigenetic mark involved in the regulation of transcription, usually associated with transcriptional repression. In mammals, methylated cytosines are found predominantly in CpGs but in plants non-CpG methylation (in the CpHpG or CpHpH contexts, where H is A, C or T) is also present and is associated with the transcriptional silencing of transposable elements. In addition, CpG methylation is found in coding regions of active genes. In the absence of the demethylas...

Zebrafish embryos as a screen for DNA methylation modifications after compound exposure

Energy Technology Data Exchange (ETDEWEB)

Bouwmeester, Manon C.; Ruiter, Sander; Lommelaars, Tobias; Sippel, Josefine; Hodemaekers, Hennie M. [Center for Health Protection, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven (Netherlands); Brandhof, Evert-Jan van den [Center for Environmental Quality, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven (Netherlands); Pennings, Jeroen L.A. [Center for Health Protection, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven (Netherlands); Kamstra, Jorke H. [Institute for Environmental Studies (IVM), VU University, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands); Jelinek, Jaroslav [Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, PA (United States); Issa, Jean-Pierre J. [Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, PA (United States); Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX (United States); Legler, Juliette [Institute for Environmental Studies (IVM), VU University, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands); Ven, Leo T.M. van der, E-mail: leo.van.der.ven@rivm.nl [Center for Health Protection, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven (Netherlands)

2016-01-15

Modified epigenetic programming early in life is proposed to underlie the development of an adverse adult phenotype, known as the Developmental Origins of Health and Disease (DOHaD) concept. Several environmental contaminants have been implicated as modifying factors of the developing epigenome. This underlines the need to investigate this newly recognized toxicological risk and systematically screen for the epigenome modifying potential of compounds. In this study, we examined the applicability of the zebrafish embryo as a screening model for DNA methylation modifications. Embryos were exposed from 0 to 72 h post fertilization (hpf) to bisphenol-A (BPA), diethylstilbestrol, 17α-ethynylestradiol, nickel, cadmium, tributyltin, arsenite, perfluoroctanoic acid, valproic acid, flusilazole, 5-azacytidine (5AC) in subtoxic concentrations. Both global and site-specific methylation was examined. Global methylation was only affected by 5AC. Genome wide locus-specific analysis was performed for BPA exposed embryos using Digital Restriction Enzyme Analysis of Methylation (DREAM), which showed minimal wide scale effects on the genome, whereas potential informative markers were not confirmed by pyrosequencing. Site-specific methylation was examined in the promoter regions of three selected genes vasa, vtg1 and cyp19a2, of which vasa (ddx4) was the most responsive. This analysis distinguished estrogenic compounds from metals by direction and sensitivity of the effect compared to embryotoxicity. In conclusion, the zebrafish embryo is a potential screening tool to examine DNA methylation modifications after xenobiotic exposure. The next step is to examine the adult phenotype of exposed embryos and to analyze molecular mechanisms that potentially link epigenetic effects and altered phenotypes, to support the DOHaD hypothesis. - Highlights: • Compound induced effects on DNA methylation in zebrafish embryos • Global methylation not an informative biomarker • Minimal genome

Zebrafish embryos as a screen for DNA methylation modifications after compound exposure

International Nuclear Information System (INIS)

Bouwmeester, Manon C.; Ruiter, Sander; Lommelaars, Tobias; Sippel, Josefine; Hodemaekers, Hennie M.; Brandhof, Evert-Jan van den; Pennings, Jeroen L.A.; Kamstra, Jorke H.; Jelinek, Jaroslav; Issa, Jean-Pierre J.; Legler, Juliette; Ven, Leo T.M. van der

2016-01-01

Modified epigenetic programming early in life is proposed to underlie the development of an adverse adult phenotype, known as the Developmental Origins of Health and Disease (DOHaD) concept. Several environmental contaminants have been implicated as modifying factors of the developing epigenome. This underlines the need to investigate this newly recognized toxicological risk and systematically screen for the epigenome modifying potential of compounds. In this study, we examined the applicability of the zebrafish embryo as a screening model for DNA methylation modifications. Embryos were exposed from 0 to 72 h post fertilization (hpf) to bisphenol-A (BPA), diethylstilbestrol, 17α-ethynylestradiol, nickel, cadmium, tributyltin, arsenite, perfluoroctanoic acid, valproic acid, flusilazole, 5-azacytidine (5AC) in subtoxic concentrations. Both global and site-specific methylation was examined. Global methylation was only affected by 5AC. Genome wide locus-specific analysis was performed for BPA exposed embryos using Digital Restriction Enzyme Analysis of Methylation (DREAM), which showed minimal wide scale effects on the genome, whereas potential informative markers were not confirmed by pyrosequencing. Site-specific methylation was examined in the promoter regions of three selected genes vasa, vtg1 and cyp19a2, of which vasa (ddx4) was the most responsive. This analysis distinguished estrogenic compounds from metals by direction and sensitivity of the effect compared to embryotoxicity. In conclusion, the zebrafish embryo is a potential screening tool to examine DNA methylation modifications after xenobiotic exposure. The next step is to examine the adult phenotype of exposed embryos and to analyze molecular mechanisms that potentially link epigenetic effects and altered phenotypes, to support the DOHaD hypothesis. - Highlights: • Compound induced effects on DNA methylation in zebrafish embryos • Global methylation not an informative biomarker • Minimal genome

miRNAting control of DNA methylation

Indian Academy of Sciences (India)

DNA methylation is a type of epigenetic modification where a methyl group is added to the cytosine or adenine residue of a given DNA sequence. It has been observed that DNA methylation is achieved by some collaborative agglomeration of certain proteins and non-coding RNAs. The assembly of IDN2 and its ...

Analysis of DNA Methylation of Gracilariopsis lemaneiformis Under Temperature Stress Using the Methylation Sensitive Amplification Polymorphism (MSAP) Technique

Science.gov (United States)

Peng, Chong; Sui, Zhenghong; Zhou, Wei; Hu, Yiyi; Mi, Ping; Jiang, Minjie; Li, Xiaodong; Ruan, Xudong

2018-06-01

Gracilariopsis lemaneiformis is an economically important agarophyte, which contains high quality gel and shows a high growth rate. Wild population of G. lemaneiformis displayed resident divergence, though with a low genetic diversity as was revealed by amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) analyses. In addition, different strains of G. lemaneiformis are diverse in morphology. The highly inconsistence between genetic background and physiological characteristics recommends strongly to the regulation at epigenetic level. In this study, the DNA methylation change in G. lemaneiformis among different generation branches and under different temperature stresses was assessed using methylation sensitive amplified polymorphism (MSAP) technique. It was shown that DNA methylation level among different generation branches was diverse. The full and total methylated DNA level was the lowest in the second generation branch and the highest in the third generation. The total methylation level was 61.11%, 60.88% and 64.12% at 15°C, 22°C and 26°C, respectively. Compared with the control group (22°C), the fully methylated and totally methylated ratios were increased in both experiment groups (15°C and 26°C). All of the cytosine methylation/demethylation transform (CMDT) was further analyzed. High temperature treatment could induce more CMDT than low temperature treatment did.

Neighborhood characteristics influence DNA methylation of genes involved in stress response and inflammation: The Multi-Ethnic Study of Atherosclerosis.

Science.gov (United States)

Smith, Jennifer A; Zhao, Wei; Wang, Xu; Ratliff, Scott M; Mukherjee, Bhramar; Kardia, Sharon L R; Liu, Yongmei; Roux, Ava V Diez; Needham, Belinda L

2017-08-01

Living in a disadvantaged neighborhood is associated with poor health outcomes even after accounting for individual-level socioeconomic factors. The chronic stress of unfavorable neighborhood conditions may lead to dysregulation of the stress reactivity and inflammatory pathways, potentially mediated through epigenetic mechanisms such as DNA methylation. We used multi-level models to examine the relationship between 2 neighborhood conditions and methylation levels of 18 genes related to stress reactivity and inflammation in purified monocytes from 1,226 participants of the Multi-Ethnic Study of Atherosclerosis (MESA), a population-based sample of US adults. Neighborhood socioeconomic disadvantage, a summary of 16 census-based metrics, was associated with DNA methylation [False discovery rate (FDR) q-value ≤ 0.1] in 2 out of 7 stress-related genes evaluated (CRF, SLC6A4) and 2 out of 11 inflammation-related genes (F8, TLR1). Neighborhood social environment, a summary measure of aesthetic quality, safety, and social cohesion, was associated with methylation in 4 of the 7 stress-related genes (AVP, BDNF, FKBP5, SLC6A4) and 7 of the 11 inflammation-related genes (CCL1, CD1D, F8, KLRG1, NLRP12, SLAMF7, TLR1). High socioeconomic disadvantage and worse social environment were primarily associated with increased methylation. In 5 genes with significant associations between neighborhood and methylation (FKBP5, CD1D, F8, KLRG1, NLRP12), methylation was associated with gene expression of at least one transcript. These results demonstrate that multiple dimensions of neighborhood context may influence methylation levels and subsequent gene expression of stress- and inflammation-related genes, even after accounting for individual socioeconomic factors. Further elucidating the molecular mechanisms underlying these relationships will be important for understanding the etiology of health disparities.

Colorectal Cancer "Methylator Phenotype": Fact or Artifact?

Directory of Open Access Journals (Sweden)

Charles Anacleto

2005-04-01

Full Text Available It has been proposed that human colorectal tumors can be classified into two groups: one in which methylation is rare, and another with methylation of several loci associated with a "CpG island methylated phenotype (CIMP," characterized by preferential proximal location in the colon, but otherwise poorly defined. There is considerable overlap between this putative methylator phenotype and the well-known mutator phenotype associated with microsatellite instability (MSI. We have examined hypermethylation of the promoter region of five genes (DAPK, MGMT, hMLH1, p16INK4a, and p14ARF in 106 primary colorectal cancers. A graph depicting the frequency of methylated loci in the series of tumors showed a continuous, monotonically decreasing distribution quite different from the previously claimed discontinuity. We observed a significant association between the presence of three or more methylated loci and the proximal location of the tumors. However, if we remove from analysis the tumors with hMLH1 methylation or those with MSI, the significance vanishes, suggesting that the association between multiple methylations and proximal location was indirect due to the correlation with MSI. Thus, our data do not support the independent existence of the so-called methylator phenotype and suggest that it rather may represent a statistical artifact caused by confounding of associations.

Health Risk Assessment for Inhalation Exposure to Methyl Tertiary Butyl Ether at Petrol Stations in Southern China.

Science.gov (United States)

Hu, Dalin; Yang, Jianping; Liu, Yungang; Zhang, Wenjuan; Peng, Xiaowu; Wei, Qinzhi; Yuan, Jianhui; Zhu, Zhiliang

2016-02-06

Methyl tertiary butyl ether (MTBE), a well known gasoline additive, is used in China nationwide to enhance the octane number of gasoline and reduce harmful exhaust emissions, yet little is known regarding the potential health risk associated with occupational exposure to MTBE in petrol stations. In this study, 97 petrol station attendants (PSAs) in southern China were recruited for an assessment of the health risk associated with inhalation exposure to MTBE. The personal exposure levels of MTBE were analyzed by Head Space Solid Phase Microextraction GC/MS, and the demographic characteristics of the PSAs were investigated. Cancer and non-cancer risks were calculated with the methods recommended by the United States Environmental Protection Agency. The results showed that the exposure levels of MTBE in operating workers were much higher than among support staff (p < 0.01) and both were lower than 50 ppm (an occupational threshold limit value). The calculated cancer risks (CRs) at the investigated petrol stations was 0.170 to 0.240 per 10⁶ for operating workers, and 0.026 to 0.049 per 10⁶ for support staff, which are below the typical target range for risk management of 1 × 10(-6) to 1 × 10(-4); The hazard quotients (HQs) for all subjects were <1. In conclusion, our study indicates that the MTBE exposure of PSAs in southern China is in a low range which does not seem to be a significant health risk.

Health Risk Assessment for Inhalation Exposure to Methyl Tertiary Butyl Ether at Petrol Stations in Southern China

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Dalin Hu

2016-02-01

Full Text Available Methyl tertiary butyl ether (MTBE, a well known gasoline additive, is used in China nationwide to enhance the octane number of gasoline and reduce harmful exhaust emissions, yet  little is known regarding the potential health risk associated with occupational exposure to MTBE in petrol stations. In this study, 97 petrol station attendants (PSAs in southern China were recruited for an assessment of the health risk associated with inhalation exposure to MTBE. The personal exposure levels of MTBE were analyzed by Head Space Solid Phase Microextraction GC/MS, and the demographic characteristics of the PSAs were investigated. Cancer and non-cancer risks were calculated with the methods recommended by the United States Environmental Protection Agency. The results showed that the exposure levels of MTBE in operating workers were much higher than among support staff (p < 0.01 and both were lower than 50 ppm (an occupational threshold limit value. The calculated cancer risks (CRs at the investigated petrol stations was 0.170 to 0.240 per 106 for operating workers, and 0.026 to 0.049 per 106 for support staff, which are below the typical target range for risk management of 1 × 10−6 to 1 × 10−4; The hazard quotients (HQs for all subjects were <1. In conclusion, our study indicates that the MTBE exposure of PSAs in southern China is in a low range which does not seem to be a significant health risk.

Synthesis of N-methyl and N-11C-methyl spiperone by phase transfer catalysis in anhydrous solvent

International Nuclear Information System (INIS)

Omokawa, Hiroyoshi; Tanaka, Akira; Iio, Mayumi; Nishihara, Yoshiaki; Inoue, Osamu; Yamazaki, Toshio.

1985-01-01

Spiperone, a butyrophenone neuroleptic drug, has been used in binding studies of dopamine receptors. Langstrom et al. developed N- 11 C-methyl spiperone, and, in cooperate with Wagner et al., made it possible to visualize the distribution of dopamine receptors in the human brain in vivo. In this paper, we independently developed another synthetic method of N- 11 C-methyl spiperone using the phase transfer catalyst in an anhydrous solvent. Separation of the product is feasible only by passing the reactant solution through a Millipore filter and injecting it onto high pressure liquid chromatography (HPLC). The time required for the synthesis and purification of N- 11 C-methyl spiperone from 11 C-methyl iodide and spiperone was 20 min. Radiochemical yield exceeded 35 % against 11 C-methyl iodide without correcting decay of the radioactivity. (author)

Methylation profiling identified novel differentially methylated markers including OPCML and FLRT2 in prostate cancer.

Science.gov (United States)

Wu, Yu; Davison, Jerry; Qu, Xiaoyu; Morrissey, Colm; Storer, Barry; Brown, Lisha; Vessella, Robert; Nelson, Peter; Fang, Min

2016-04-02

To develop new methods to distinguish indolent from aggressive prostate cancers (PCa), we utilized comprehensive high-throughput array-based relative methylation (CHARM) assay to identify differentially methylated regions (DMRs) throughout the genome, including both CpG island (CGI) and non-CGI regions in PCa patients based on Gleason grade. Initially, 26 samples, including 8 each of low [Gleason score (GS) 6] and high (GS ≥7) grade PCa samples and 10 matched normal prostate tissues, were analyzed as a discovery cohort. We identified 3,567 DMRs between normal and cancer tissues, and 913 DMRs distinguishing low from high-grade cancers. Most of these DMRs were located at CGI shores. The top 5 candidate DMRs from the low vs. high Gleason comparison, including OPCML, ELAVL2, EXT1, IRX5, and FLRT2, were validated by pyrosequencing using the discovery cohort. OPCML and FLRT2 were further validated in an independent cohort consisting of 20 low-Gleason and 33 high-Gleason tissues. We then compared patients with biochemical recurrence (n=70) vs. those without (n=86) in a third cohort, and they showed no difference in methylation at these DMR loci. When GS 3+4 cases and GS 4+3 cases were compared, OPCML-DMR methylation showed a trend of lower methylation in the recurrence group (n=30) than in the no-recurrence (n=52) group. We conclude that whole-genome methylation profiling with CHARM revealed distinct patterns of differential DNA methylation between normal prostate and PCa tissues, as well as between different risk groups of PCa as defined by Gleason scores. A panel of selected DMRs may serve as novel surrogate biomarkers for Gleason score in PCa.

[Specific features of 2-methyl hydroxybenzene and 3-methyl hydroxybenzene distribution in the organism of warm-blooded animals].

Science.gov (United States)

Shormanov, B K; Grishenko, V K; Astashkina, A P; Elizarova, M K

2013-01-01

The present work was designed to study the specific features of 2-methyl hydroxybezene and 3-methyl hydroxybenzene distribution after intragastric administration of these toxicants to warm-blooded animals (rats). They were detected in the unmetabolized form in the internal organs and blood of the animals. The levels of 2-methyl hydroxybezene were especially high in the stomach and blood whereas the maximum content of 3-methyl hydroxybenzene was found in brain, blood, small intestines of the poisoned rats.

Genome-wide DNA methylation maps in follicular lymphoma cells determined by methylation-enriched bisulfite sequencing.

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Jeong-Hyeon Choi

Full Text Available BACKGROUND: Follicular lymphoma (FL is a form of non-Hodgkin's lymphoma (NHL that arises from germinal center (GC B-cells. Despite the significant advances in immunotherapy, FL is still not curable. Beyond transcriptional profiling and genomics datasets, there currently is no epigenome-scale dataset or integrative biology approach that can adequately model this disease and therefore identify novel mechanisms and targets for successful prevention and treatment of FL. METHODOLOGY/PRINCIPAL FINDINGS: We performed methylation-enriched genome-wide bisulfite sequencing of FL cells and normal CD19(+ B-cells using 454 sequencing technology. The methylated DNA fragments were enriched with methyl-binding proteins, treated with bisulfite, and sequenced using the Roche-454 GS FLX sequencer. The total number of bases covered in the human genome was 18.2 and 49.3 million including 726,003 and 1.3 million CpGs in FL and CD19(+ B-cells, respectively. 11,971 and 7,882 methylated regions of interest (MRIs were identified respectively. The genome-wide distribution of these MRIs displayed significant differences between FL and normal B-cells. A reverse trend in the distribution of MRIs between the promoter and the gene body was observed in FL and CD19(+ B-cells. The MRIs identified in FL cells also correlated well with transcriptomic data and ChIP-on-Chip analyses of genome-wide histone modifications such as tri-methyl-H3K27, and tri-methyl-H3K4, indicating a concerted epigenetic alteration in FL cells. CONCLUSIONS/SIGNIFICANCE: This study is the first to provide a large scale and comprehensive analysis of the DNA methylation sequence composition and distribution in the FL epigenome. These integrated approaches have led to the discovery of novel and frequent targets of aberrant epigenetic alterations. The genome-wide bisulfite sequencing approach developed here can be a useful tool for profiling DNA methylation in clinical samples.

Modeling spatiotemporal dynamics of DNA methylation

DEFF Research Database (Denmark)

Lövkvist, Cecilia Elisabet

into how epigenetic marks are distributed in the human genome. In the first part of the thesis, we investigate DNA methylation and maintenance of methylation patterns throughout cell division. We argue that collaborative models, those where the methylation of CpG sites depends on the methylation status...... into the game more explicitly in another type of model that speaks out the duality of the two aspects. Using statistical analysis of experimental data, this thesis further explores a link between DNA methylation and nucleosome occupancy. By comparing the patterns on promoters to regions with similar Cp...... division. The patterns of epigentic marks depend on enzymes that ensure their maintenance and introduction. Using theoretical models, this thesis proposes new mechanisms for how enzymes operate to maintain patterns of epigenetic marks. Through analysis of experimental data this work gives new insight...

Experimental and chemical kinetic modeling study of small methyl esters oxidation: Methyl (E)-2-butenoate and methyl butanoate

Energy Technology Data Exchange (ETDEWEB)

Gail, S.; Sarathy, S.M.; Thomson, M.J. [Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON M5S 3G8 (Canada); Dievart, P.; Dagaut, P. [CNRS, 1C, Ave de la Recherche Scientifique, 45071 Orleans Cedex 2 (France)

2008-12-15

This study examines the effect of unsaturation on the combustion of fatty acid methyl esters (FAME). New experimental results were obtained for the oxidation of methyl (E)-2-butenoate (MC, unsaturated C{sub 4} FAME) and methyl butanoate (MB, saturated C{sub 4} FAME) in a jet-stirred reactor (JSR) at atmospheric pressure under dilute conditions over the temperature range 850-1400 K, and two equivalence ratios ({phi}=0.375,0.75) with a residence time of 0.07 s. The results consist of concentration profiles of the reactants, stable intermediates, and final products, measured by probe sampling followed by on-line and off-line gas chromatography analyses. The oxidation of MC and MB in the JSR and under counterflow diffusion flame conditions was modeled using a new detailed chemical kinetic reaction mechanism (301 species and 1516 reactions) derived from previous schemes proposed in the literature. The laminar counterflow flame and JSR (for {phi}=1.13) experimental results used were from a previous study on the comparison of the combustion of both compounds. Sensitivity analyses and reaction path analyses, based on rates of reaction, were used to interpret the results. The data and the model show that MC has reaction pathways analogous to that of MB under the present conditions. The model of MC oxidation provides a better understanding of the effect of the ester function on combustion, and the effect of unsaturation on the combustion of fatty acid methyl ester compounds typically found in biodiesel. (author)

Pleiotropic effects of a methyl donor diet in a novel animal model.

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Kimberly R Shorter

Full Text Available Folate and other methyl-donor pathway components are widely supplemented due to their ability to prevent prenatal neural tube defects. Several lines of evidence suggest that these supplements act through epigenetic mechanisms (e.g. altering DNA methylation. Primary among these are the experiments on the mouse viable yellow allele of the agouti locus (A(vy. In the Avy allele, an Intracisternal A-particle retroelement has inserted into the genome adjacent to the agouti gene and is preferentially methylated. To further test these effects, we tested the same diet used in the Avy studies on wild-derived Peromyscus maniculatus, a native North American rodent. We collected tissues from neonatal offspring whose parents were fed the high-methyl donor diet as well as controls. In addition, we assayed coat-color of a natural variant (wide-band agouti = A(Nb that overexpresses agouti as a phenotypic biomarker. Our data indicate that these dietary components affected agouti protein production, despite the lack of a retroelement at this locus. Surprisingly, the methyl-donor diet was associated with defects (e.g. ovarian cysts, cataracts and increased mortality. We also assessed the effects of the diet on behavior: We scored animals in open field and social interaction tests. We observed significant increases in female repetitive behaviors. Thus these data add to a growing number of studies that suggest that these ubiquitously added nutrients may be a human health concern.

Naturally occurring methyl salicylate glycosides.

Science.gov (United States)

Mao, Ping; Liu, Zizhen; Xie, Meng; Jiang, Rui; Liu, Weirui; Wang, Xiaohong; Meng, Shen; She, Gaimei

2014-01-01

As an important part of non steroids anti-inflammation drug (NSAIDs), salicylate has developed from natural substance salicylic acid to natrium salicylicum, to aspirin. Now, methyl salicylate glycoside, a new derivative of salicylic acid, is modified with a -COOH group integrated one methyl radical into formic ether, and a -OH linked with a monosaccharide, a disaccharide or a trisaccharide unit by glycosidic linkage. It has the similar pharmacological activities, anti-inflammatory, analgesic, antipyretic and antithrombotic as the previous salicylates' without resulting in serious side effects, particularly the gastrointestinal toxicity. Owing to the superiority of those significant bioactivities, methyl salicylate glycosides have became a hot research area in NSAIDs for several years. This paper compiles all 9 naturally occurring methyl salicylate glycosides, their distribution of the resource and pharmacological mechanism, which could contribute to the new drug discovery.

Protein methylation reactions in intact pea chloroplasts

International Nuclear Information System (INIS)

Niemi, K.J.

1989-01-01

Post-translational protein methylation was investigated in Pisum sativum chloroplasts. Intact pea chloroplasts were incubated with ( 3 H-methyl)-S-adenosylmethionine under various conditions. The chloroplasts were then separated into stromal and thylakoid fractions and analyzed for radioactivity transferred to protein. Light enhanced the magnitude of labeling in both fractions. One thylakoid polypeptide with an apparent molecular mass of 43 kDa was labeled only in the light. Several other thylakoid and stromal proteins were labeled in both light and dark-labeling conditions. Both base-labile methylation, carboxy-methylesters and base-stable groups, N-methylations were found. Further characterization of the methyl-transfer reactions will be presented

Molecular correlates with MGMT promoter methylation and silencing support CpG island methylator phenotype-low (CIMP-low) in colorectal cancer.

Science.gov (United States)

Ogino, Shuji; Kawasaki, Takako; Kirkner, Gregory J; Suemoto, Yuko; Meyerhardt, Jeffrey A; Fuchs, Charles S

2007-11-01

The CpG island methylator phenotype (CIMP or CIMP-high) with widespread promoter methylation is a distinct epigenetic phenotype in colorectal cancer. In contrast, a phenotype with less widespread promoter methylation (CIMP-low) has not been well characterised. O-6-methylguanine-DNA methyltransferase (MGMT) promoter methylation and silencing have been associated with G>A mutations and microsatellite instability-low (MSI-low). To examine molecular correlates with MGMT methylation/silencing in colorectal cancer. Utilising MethyLight technology, we quantified DNA methylation in MGMT and eight other markers (a CIMP-diagnostic panel; CACNA1G, CDKN2A (p16), CRABP1, IGF2, MLH1, NEUROG1, RUNX3 and SOCS1) in 920 population-based colorectal cancers. Tumours with both MGMT methylation and loss were correlated positively with MSI-low (p = 0.02), CIMP-high (>or=6/8 methylated CIMP markers, p = 0.005), CIMP-low (1/8-5/8 methylated CIMP markers, p = 0.002, compared to CIMP-0 with 0/8 methylated markers), KRAS G>A mutation (p = 0.02), and inversely with 18q loss of heterozygosity (p = 0.0002). Tumours were classified into nine MSI/CIMP subtypes. Among the CIMP-low group, tumours with both MGMT methylation and loss were far more frequent in MSI-low tumours (67%, 12/18) than MSI-high tumours (5.6%, 1/18; p = 0.0003) and microsatellite stable (MSS) tumours (33%, 52/160; p = 0.008). However, no such relationship was observed among the CIMP-high or CIMP-0 groups. The relationship between MGMT methylation/silencing and MSI-low is limited to only CIMP-low tumours, supporting the suggestion that CIMP-low in colorectal cancer may be a different molecular phenotype from CIMP-high and CIMP-0. Our data support a molecular difference between MSI-low and MSS in colorectal cancer, and a possible link between CIMP-low, MSI-low, MGMT methylation/loss and KRAS mutation.

Phytase production by Aspergillus niger NCIM 563 for a novel application to degrade organophosphorus pesticides.

Science.gov (United States)

Shah, Parin C; Kumar, V Ravi; Dastager, Syed G; Khire, Jayant M

2017-12-01

The production of phytase using Aspergillus niger NCIM 563 under submerged fermentation conditions was studied using protein rich chickpea flour as substrate. Employing a hybrid statistical media optimization strategy of Plackett-Burman and Box-Behnken experimental designs in shake-flasks gave an increased phytase activity from an initial 66 IU/mL in 216 h to 160 IU/mL in a reduced time of 132 h. Productivity, thus increased by 3.97 times from 7.3 to 29 IU/mL/day. Using the optimized media, the production was successfully scaled-up further and improved up to 164 IU/mL in 96 h by studies carried out employing 2 and 10-L fermenters. The enzyme supernatant was recovered using centrifugal separation of biomass and the stability of the produced phytase was tested for animal feed applications under gastric conditions. In vitro degradation studies of water soluble monocrotophos, methyl parathion and water insoluble chlorpyrifos, pesticides used extensively in agriculture was carried out. It was observed by HPLC analysis that phytase could degrade 72% of chlorpyrifos at pH 7.0, 35 °C. Comparable results were obtained with monocrotophos and methyl parathion. With chlorpyrifos at higher temperature 50 °C as much as 91% degradation could be obtained. The degradation of chlorpyrifos was further validated by spraying phytase on harvested green chilli (Capsicum annuum L) under normal conditions of pH 7.0, 35 °C and the degradation products obtained analyzed by LCMS. Thus, the present study brings out a potentially novel application of phytase for biodegradation of organophosphorus pesticides.

Degradation of pesticides with RSDL® (reactive skin decontamination lotion kit) lotion: LC-MS investigation.

Science.gov (United States)

Fentabil, Messele; Gebremedhin, Mulu; Purdon, J Garfield; Cochrane, Laura; Goldman, Virginia Streusand

2018-09-01

This study examined the degradation of organophosphate (OP) and carbamate pesticides using RSDL ® (Reactive Skin Decontamination Lotion Kit) lotion. Degradation occurs from a nucleophilic substitution (SN) reaction between an ingredient in the RSDL lotion, potassium 2,3-butanedione monoximate (KBDO), with susceptible sites in the pesticides. Evaluation at several molar ratios of KBDO:test articles using liquid chromatography-mass spectrometry (LC-MS) techniques was performed. The OP test articles, parathion, paraoxon, parathion-methyl, paraoxon-methyl and chlorpyrifos were effectively degraded at molar ratios of four and above in less than 6min contact time. Malathion and malaoxon were similarly converted to inactive by-products at molar ratios as low as two in less than 4min. A minimum molar ratio of nine was found to be effective against the carbamate pesticide carbofuran. In the case of aldicarb, complete destruction was achieved at a molar ratio of fifteen and a reaction time of one hour. It is important to note that these studies are based on a direct liquid phase RSDL lotion reaction with the toxic chemicals without the added physical removal decontamination efficacy component provided by the sponge component of the RSDL kit. The RSDL kit is intended to be used to remove or neutralize chemical warfare agents (CWA) and T-2 toxin from the skin. In actual use, the majority of the CWA decontamination occurs through the combined action of the sponge in both removing the chemical from the skin, and in rapidly mixing the chemicals at a high molar ratio of KBDO:CWA within the pores of the sponge to enhance rapid neutralization of the chemical. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of Methyl-Binding Domain Based Enrichment Approaches Revisited.

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Karolina A Aberg

Full Text Available Methyl-binding domain (MBD enrichment followed by deep sequencing (MBD-seq, is a robust and cost efficient approach for methylome-wide association studies (MWAS. MBD-seq has been demonstrated to be capable of identifying differentially methylated regions, detecting previously reported robust associations and producing findings that replicate with other technologies such as targeted pyrosequencing of bisulfite converted DNA. There are several kits commercially available that can be used for MBD enrichment. Our previous work has involved MethylMiner (Life Technologies, Foster City, CA, USA that we chose after careful investigation of its properties. However, in a recent evaluation of five commercially available MBD-enrichment kits the performance of the MethylMiner was deemed poor. Given our positive experience with MethylMiner, we were surprised by this report. In an attempt to reproduce these findings we here have performed a direct comparison of MethylMiner with MethylCap (Diagenode Inc, Denville, NJ, USA, the best performing kit in that study. We find that both MethylMiner and MethylCap are two well performing MBD-enrichment kits. However, MethylMiner shows somewhat better enrichment efficiency and lower levels of background "noise". In addition, for the purpose of MWAS where we want to investigate the majority of CpGs, we find MethylMiner to be superior as it allows tailoring the enrichment to the regions where most CpGs are located. Using targeted bisulfite sequencing we confirmed that sites where methylation was detected by either MethylMiner or by MethylCap indeed were methylated.

IGFBP3 Promoter Methylation in Colorectal Cancer: Relationship with Microsatellite Instability, CpG Island Methylator Phenotype, p53

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Takako Kawasaki

2007-12-01

Full Text Available Insulin-like growth factor binding protein 3 (IGFBP3, which is induced by wild-type p53, regulates IGF and interacts with the TGF-β pathway. IGFBP3 promoter methylation may occur in colorectal cancer with or without the CpG island methylator phenotype (CIMP, which is associated with microsatellite instability (MSI and TGFBR2 mutation. We examined the relationship between IGFBP3 methylation, p53 expression, CIMP and MSI in 902 population-based colorectal cancers. Utilizing real-time PCR (MethyLight, we quantified promoter methylation in IGFBP3 and eight other CIMP-high-specific promoters (CACNA1G, CDKN2A, CRABP1, IGF2, MLH1, NEUROG1, RUNX3, and SOCS1. IGFBP3 methylation was far more frequent in non-MSI-high CIMP-high tumors (85% = 35/41 than in MSI-high CIMPhigh (49% = 44/90, P < .0001, MSI-high non-CIMP-high (17% = 6/36, P < .0001, non-MSI-high non-CIMP-high tumors (22% = 152/680, P < .0001. Among CIMPhigh tumors, the inverse relationship between MSI and IGFBP3 methylation persisted in p53-negative tumors (P < .0001, but not in p53-positive tumors. IGFBP3 methylation was associated inversely with TGFBR2 mutation in MSI-high non-CIMP-high tumors (P = .02. In conclusion, IGFBP3 methylation is inversely associated with MSI in CIMP-high colorectal cancers, this relationship is limited to p53-negative tumors. Our data suggest complex relationship between global genomic/epigenomic phenomena (such as MSI/ CIMP, single molecular events (e.g., IGFBP3 methylation, TP53 mutation, TGFBR2 mutation, the related pathways.

Osteoponin Promoter Controlled by DNA Methylation: Aberrant Methylation in Cloned Porcine Genome

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Chih-Jie Shen

2014-01-01

Full Text Available Cloned animals usually exhibited many defects in physical characteristics or aberrant epigenetic reprogramming, especially in some important organ development. Osteoponin (OPN is an extracellular-matrix protein involved in heart and bone development and diseases. In this study, we investigated the correlation between OPN mRNA and its promoter methylation changes by the 5-aza-dc treatment in fibroblast cell and promoter assay. Aberrant methylation of porcine OPN was frequently found in different tissues of somatic nuclear transferred cloning pigs, and bisulfite sequence data suggested that the OPN promoter region −2615 to −2239 nucleotides (nt may be a crucial regulation DNA element. In pig ear fibroblast cell culture study, the demethylation of OPN promoter was found in dose-dependent response of 5-aza-dc treatment and followed the OPN mRNA reexpression. In cloned pig study, discrepant expression pattern was identified in several cloned pig tissues, especially in brain, heart, and ear. Promoter assay data revealed that four methylated CpG sites presenting in the −2615 to −2239 nt region cause significant downregulation of OPN promoter activity. These data suggested that methylation in the OPN promoter plays a crucial role in the regulation of OPN expression that we found in cloned pigs genome.

Developmental differences in posttranslational calmodulin methylation in pea plants

International Nuclear Information System (INIS)

Oh, Sukheung; Roberts, D.M.

1990-01-01

A calmodulin-N-methyltransferase was used to analyze the degree of lysine-115 methylation of pea calmodulin. Calmodulin was isolated from segments of developing roots of young etiolated and green pea plants and was tested for its ability to be methylated by the calmodulin methyltransferase in the presence of 3 H-methyl-S-adenosylmethionine. Calmodulin methylation levels were lower in apical root segments and in the young lateral roots compared with the mature, differentiated root tissues. The methylation of these calmodulin samples occurs specifically at lysine 115 since site-directed mutants of calmodulin with substitutions at this position were not methylated and competitively inhibited methylation. The present findings, combined with previous data showing differences in NAD kinase activation by methylated and unmethylated calmodulins, raise the possibility that posttranslational methylation could affect calmodulin action

Longitudinal study of DNA methylation during the first 5 years of life.

Science.gov (United States)

Urdinguio, Rocio G; Torró, María Isabel; Bayón, Gustavo F; Álvarez-Pitti, Julio; Fernández, Agustín F; Redon, Pau; Fraga, Mario F; Lurbe, Empar

2016-06-03

Early life epigenetic programming influences adult health outcomes. Moreover, DNA methylation levels have been found to change more rapidly during the first years of life. Our aim was the identification and characterization of the CpG sites that are modified with time during the first years of life. We hypothesize that these DNA methylation changes would lead to the detection of genes that might be epigenetically modulated by environmental factors during early childhood and which, if disturbed, might contribute to susceptibility to diseases later in life. The study of the DNA methylation pattern of 485577 CpG sites was performed on 30 blood samples from 15 subjects, collected both at birth and at 5 years old, using Illumina(®) Infinium 450 k array. To identify differentially methylated CpG (dmCpG) sites, the methylation status of each probe was examined using linear models and the Empirical Bayes Moderated t test implemented in the limma package of R/Bioconductor. Surogate variable analysis was used to account for batch effects. DNA methylation levels significantly changed from birth to 5 years of age in 6641 CpG sites. Of these, 36.79 % were hypermethylated and were associated with genes related mainly to developmental ontology terms, while 63.21 % were hypomethylated probes and associated with genes related to immune function. Our results suggest that DNA methylation alterations with age during the first years of life might play a significant role in development and the regulation of leukocyte-specific functions. This supports the idea that blood leukocytes experience genome remodeling related to their interaction with environmental factors, underlining the importance of environmental exposures during the first years of life and suggesting that new strategies should be take into consideration for disease prevention.

Patterns of cytosine methylation in an elite rice hybrid and its parental lines, detected by a methylation-sensitive amplification polymorphism technique.

Science.gov (United States)

Xiong, L Z; Xu, C G; Saghai Maroof, M A; Zhang, Q

1999-04-01

DNA methylation is known to play an important role in the regulation of gene expression in eukaryotes. In this study, we assessed the extent and pattern of cytosine methylation in the rice genome, using the technique of methylation-sensitive amplified polymorphism (MSAP), which is a modification of the amplified fragment length polymorphism (AFLP) method that makes use of the differential sensitivity of a pair of isoschizomers to cytosine methylation. The tissues assayed included seedlings and flag leaves of an elite rice hybrid, Shanyou 63, and the parental lines Zhenshan 97 and Minghui 63. In all, 1076 fragments, each representing a recognition site cleaved by either or both of the isoschizomers, were amplified using 16 pairs of selective primers. A total of 195 sites were found to be methylated at cytosines in one or both parents, and the two parents showed approximately the same overall degree of methylation (16.3%), as revealed by the incidence of differential digestion by the isoschizomers. Four classes of patterns were identified in a comparative assay of cytosine methylation in the parents and hybrid; increased methylation was detected in the hybrid compared to the parents at some of the recognition sites, while decreased methylation in the hybrid was detected at other sites. A small proportion of the sites was found to be differentially methylated in seedlings and flag leaves; DNA from young seedlings was methylated to a greater extent than that from flag leaves. Almost all of the methylation patterns detected by MSAP could be confirmed by Southern analysis using the isolated amplified fragments as probes. The results clearly demonstrate that the MSAP technique is highly efficient for large-scale detection of cytosine methylation in the rice genome. We believe that the technique can be adapted for use in other plant species.

Methylation sensitive amplified polymorphism (MSAP) reveals that ...

African Journals Online (AJOL)

ajl yemi

2011-12-19

Dec 19, 2011 ... Key words: Salt stress, alkali stress, Gossypium hirsutum L., DNA methylation, methylation sensitive amplified polymorphism (MSAP). INTRODUCTION. DNA methylation is one of the key epigenetic mecha- nisms among eukaryotes that can modulate gene expression without the changes of DNA sequence.

Thermal Decomposition of Potential Ester Biofuels. Part I: Methyl Acetate and Methyl Butanoate

Energy Technology Data Exchange (ETDEWEB)

Porterfield, Jessica P.; Bross, David H.; Ruscic, Branko; Thorpe, James H.; Nguyen, Thanh Lam; Baraban, Joshua H.; Stanton, John F.; Daily, John W.; Ellison, G. Barney

2017-06-09

Two methyl esters have been examined as models for the pyrolysis of biofuels. Dilute samples (0.06 - 0.13%) of methyl acetate (CH₃COOCH₃) and methyl butanoate (CH₃CH₂CH₂COOCH₃) were entrained in (He, Ar) carrier gas and decomposed in a set of flash-pyrolysis micro-reactors. The pyrolysis products resulting from the methyl esters were detected and identified by vacuum ultraviolet photoionization mass spectrometry. Complementary product identification was provided by matrix infrared absorption spectroscopy. Pyrolysis pressures in the pulsed micro-reactor were roughly 20 Torr and residence times through the reactors were approximately 25 - 150 µs. Reactor temperatures of 300 – 1600 K were explored. Decomposition of CH₃COOCH₃ commences at 1000 K and the initial products are (CH₂=C=O and CH₃OH). As the micro-reactor is heated to 1300 K, a mixture of (CH₂=C=O and CH₃OH, CH₃, CH₂=O, H, CO, CO₂) appears. The thermal cracking of CH₃CH₂CH₂COOCH₃ begins at 800 K with the formation of (CH₃CH₂CH=C=O, CH₃OH). By 1300 K, the pyrolysis of methyl butanoate yields a complex mixture of (CH₃CH₂CH=C=O, CH₃OH, CH₃, CH₂=O, CO, CO₂, CH₃CH=CH₂, CH₂CHCH₂, CH₂=C=CH₂, HCCCH₂, CH₂=C=C=O, CH₂=CH₂, HCΞCH, CH₂=C=O). Based on the results from the thermal cracking of methyl acetate and methyl butanoate, we predict several important decomposition channels for the pyrolysis of fatty acid methyl esters, R CH₂-COOCH₃. The lowest energy fragmentation will be a 4-center elimination of methanol to form the ketene, RCH=C=O. At higher temperatures, concerted

Electronic transport in methylated fragments of DNA

Energy Technology Data Exchange (ETDEWEB)

Almeida, M. L. de; Oliveira, J. I. N.; Lima Neto, J. X.; Gomes, C. E. M.; Fulco, U. L., E-mail: umbertofulco@gmail.com; Albuquerque, E. L. [Departamento de Biofísica e Farmacologia, Universidade Federal do Rio Grande do Norte, 59072-970 Natal-RN (Brazil); Freire, V. N. [Departamento de Física, Universidade Federal do Ceará, 60455-760 Fortaleza, CE (Brazil); Caetano, E. W. S. [Instituto Federal de Educação, Ciência e Tecnologia do Ceará, 60040-531 Fortaleza, CE (Brazil); Moura, F. A. B. F. de; Lyra, M. L. [Instituto de Física, Universidade Federal de Alagoas, 57072-900 Maceió-AL (Brazil)

2015-11-16

We investigate the electronic transport properties of methylated deoxyribonucleic-acid (DNA) strands, a biological system in which methyl groups are added to DNA (a major epigenetic modification in gene expression), sandwiched between two metallic platinum electrodes. Our theoretical simulations apply an effective Hamiltonian based on a tight-binding model to obtain current-voltage curves related to the non-methylated/methylated DNA strands. The results suggest potential applications in the development of novel biosensors for molecular diagnostics.

Electronic transport in methylated fragments of DNA

International Nuclear Information System (INIS)

Almeida, M. L. de; Oliveira, J. I. N.; Lima Neto, J. X.; Gomes, C. E. M.; Fulco, U. L.; Albuquerque, E. L.; Freire, V. N.; Caetano, E. W. S.; Moura, F. A. B. F. de; Lyra, M. L.

2015-01-01

We investigate the electronic transport properties of methylated deoxyribonucleic-acid (DNA) strands, a biological system in which methyl groups are added to DNA (a major epigenetic modification in gene expression), sandwiched between two metallic platinum electrodes. Our theoretical simulations apply an effective Hamiltonian based on a tight-binding model to obtain current-voltage curves related to the non-methylated/methylated DNA strands. The results suggest potential applications in the development of novel biosensors for molecular diagnostics

DNA Methylation Modulates Nociceptive Sensitization after Incision.

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Yuan Sun

Full Text Available DNA methylation is a key epigenetic mechanism controlling DNA accessibility and gene expression. Blockade of DNA methylation can significantly affect pain behaviors implicated in neuropathic and inflammatory pain. However, the role of DNA methylation with regard to postoperative pain has not yet been explored. In this study we sought to investigate the role of DNA methylation in modulating incisional pain and identify possible targets under DNA methylation and contributing to incisional pain. DNA methyltranferase (DNMT inhibitor 5-Aza-2'-deoxycytidine significantly reduced incision-induced mechanical allodynia and thermal sensitivity. Aza-2'-deoxycytidine also reduced hindpaw swelling after incision, suggesting an anti-inflammatory effect. Global DNA methylation and DNMT3b expression were increased in skin after incision, but none of DNMT1, DNMT3a or DNMT3b was altered in spinal cord or DRG. The expression of proopiomelanocortin Pomc encoding β-endorphin and Oprm1 encoding the mu-opioid receptor were upregulated peripherally after incision; moreover, Oprm1 expression was further increased under DNMT inhibitor treatment. Finally, local peripheral injection of the opioid receptor antagonist naloxone significantly exacerbated incision-induced mechanical hypersensitivity. These results suggest that DNA methylation is functionally relevant to incisional nociceptive sensitization, and that mu-opioid receptor signaling might be one methylation regulated pathway controlling sensitization after incision.

Methylation analysis of polysaccharides: Technical advice.

Science.gov (United States)

Sims, Ian M; Carnachan, Susan M; Bell, Tracey J; Hinkley, Simon F R

2018-05-15

Glycosyl linkage (methylation) analysis is used widely for the structural determination of oligo- and poly-saccharides. The procedure involves derivatisation of the individual component sugars of a polysaccharide to partially methylated alditol acetates which are analysed and quantified by gas chromatography-mass spectrometry. The linkage positions for each component sugar can be determined by correctly identifying the partially methylated alditol acetates. Although the methods are well established, there are many technical aspects to this procedure and both careful attention to detail and considerable experience are required to achieve a successful methylation analysis and to correctly interpret the data generated. The aim of this article is to provide the technical details and critical procedural steps necessary for a successful methylation analysis and to assist researchers (a) with interpreting data correctly and (b) in providing the comprehensive data required for reviewers to fully assess the work. Copyright © 2018 Elsevier Ltd. All rights reserved.

Two cases of methyl alcohol intoxication by sub-chronic inhalation and dermal exposure during aluminum CNC cutting in a small-sized subcontracted factory.

Science.gov (United States)

Ryu, Jia; Lim, Key Hwan; Ryu, Dong-Ryeol; Lee, Hyang Woon; Yun, Ji Young; Kim, Seoung-Wook; Kim, Ji-Hoon; Jung-Choi, Kyunghee; Kim, Hyunjoo

2016-01-01

Methyl alcohol poisoning has been mainly reported in community. Two cases of methyl alcohol poisoning occurred in a small-sized subcontracted factory which manufactured smartphone parts in Korea. One young female patient presented with dyspnea and visual disturbance. Another young male patient presented with visual disturbance and myalgia. They treated with sodium bicarbonate infusion and hemodialysis for metabolic acidosis. In addition, he received ethyl alcohol per oral treatment. Her and his urinary methyl alcohol concentration was detected as 7.632 mg/L, 46.8 mg/L, respectively, although they were treated hemodialysis. Results of the working environment measurement showed that the concentration of methyl alcohol (1030.1-2220.5 ppm) in the air exceeded the time weighted average (200 ppm). They were diagnosed with optic neuropathy due to methyl alcohol poisoning and still have visual impairment. Workers who hired as dispatched employees in a small-sized subcontracted factory were exposed to high concentrations of methyl alcohol. The workplace had poor ventilation system. In addition, workers did not wear proper personal protect equipment. Working environment measurement and annual chekups for workers were not performed. They were in a blind spot to occupational safety and health. More attention is needed to protect vulnerable workers' health.

CpG island methylator phenotype (CIMP) of colorectal cancer is best characterised by quantitative DNA methylation analysis and prospective cohort studies.

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Ogino, S; Cantor, M; Kawasaki, T; Brahmandam, M; Kirkner, G J; Weisenberger, D J; Campan, M; Laird, P W; Loda, M; Fuchs, C S

2006-07-01

The concept of CpG island methylator phenotype (CIMP) is not universally accepted. Even if specific clinicopathological features have been associated with CIMP, investigators often failed to demonstrate a bimodal distribution of the number of methylated markers, which would suggest CIMP as a distinct subtype of colorectal cancer. Previous studies primarily used methylation specific polymerase chain reaction which might detect biologically insignificant low levels of methylation. To demonstrate a distinct genetic profile of CIMP colorectal cancer using quantitative DNA methylation analysis that can distinguish high from low levels of DNA methylation. We developed quantitative real time polymerase chain reaction (MethyLight) assays and measured DNA methylation (percentage of methylated reference) of five carefully selected loci (promoters of CACNA1G, CDKN2A (p16), CRABP1, MLH1, and NEUROG1) in 460 colorectal cancers from large prospective cohorts. There was a clear bimodal distribution of 80 microsatellite instability-high (MSI-H) tumours according to the number of methylated promoters, with no tumours showing 3/5 methylated loci. Thus we defined CIMP as having >or=4/5 methylated loci, and 17% (78) of the 460 tumours were classified as CIMP. CIMP was significantly associated with female sex, MSI, BRAF mutations, and wild-type KRAS. Both CIMP MSI-H tumours and CIMP microsatellite stable (MSS) tumours showed much higher frequencies of BRAF mutations (63% and 54%) than non-CIMP counterparts (non-CIMP MSI-H (0%, pCIMP MSS tumours (6.6%, pCIMP is best characterised by quantitative DNA methylation analysis. CIMP is a distinct epigenotype of colorectal cancer and may be less frequent than previously reported.

Minimal methylation classifier (MIMIC): A novel method for derivation and rapid diagnostic detection of disease-associated DNA methylation signatures.

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Schwalbe, E C; Hicks, D; Rafiee, G; Bashton, M; Gohlke, H; Enshaei, A; Potluri, S; Matthiesen, J; Mather, M; Taleongpong, P; Chaston, R; Silmon, A; Curtis, A; Lindsey, J C; Crosier, S; Smith, A J; Goschzik, T; Doz, F; Rutkowski, S; Lannering, B; Pietsch, T; Bailey, S; Williamson, D; Clifford, S C

2017-10-18

Rapid and reliable detection of disease-associated DNA methylation patterns has major potential to advance molecular diagnostics and underpin research investigations. We describe the development and validation of minimal methylation classifier (MIMIC), combining CpG signature design from genome-wide datasets, multiplex-PCR and detection by single-base extension and MALDI-TOF mass spectrometry, in a novel method to assess multi-locus DNA methylation profiles within routine clinically-applicable assays. We illustrate the application of MIMIC to successfully identify the methylation-dependent diagnostic molecular subgroups of medulloblastoma (the most common malignant childhood brain tumour), using scant/low-quality samples remaining from the most recently completed pan-European medulloblastoma clinical trial, refractory to analysis by conventional genome-wide DNA methylation analysis. Using this approach, we identify critical DNA methylation patterns from previously inaccessible cohorts, and reveal novel survival differences between the medulloblastoma disease subgroups with significant potential for clinical exploitation.

DNA damage, homology-directed repair, and DNA methylation.

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Concetta Cuozzo

2007-07-01

Full Text Available To explore the link between DNA damage and gene silencing, we induced a DNA double-strand break in the genome of Hela or mouse embryonic stem (ES cells using I-SceI restriction endonuclease. The I-SceI site lies within one copy of two inactivated tandem repeated green fluorescent protein (GFP genes (DR-GFP. A total of 2%-4% of the cells generated a functional GFP by homology-directed repair (HR and gene conversion. However, approximately 50% of these recombinants expressed GFP poorly. Silencing was rapid and associated with HR and DNA methylation of the recombinant gene, since it was prevented in Hela cells by 5-aza-2'-deoxycytidine. ES cells deficient in DNA methyl transferase 1 yielded as many recombinants as wild-type cells, but most of these recombinants expressed GFP robustly. Half of the HR DNA molecules were de novo methylated, principally downstream to the double-strand break, and half were undermethylated relative to the uncut DNA. Methylation of the repaired gene was independent of the methylation status of the converting template. The methylation pattern of recombinant molecules derived from pools of cells carrying DR-GFP at different loci, or from an individual clone carrying DR-GFP at a single locus, was comparable. ClustalW analysis of the sequenced GFP molecules in Hela and ES cells distinguished recombinant and nonrecombinant DNA solely on the basis of their methylation profile and indicated that HR superimposed novel methylation profiles on top of the old patterns. Chromatin immunoprecipitation and RNA analysis revealed that DNA methyl transferase 1 was bound specifically to HR GFP DNA and that methylation of the repaired segment contributed to the silencing of GFP expression. Taken together, our data support a mechanistic link between HR and DNA methylation and suggest that DNA methylation in eukaryotes marks homologous recombined segments.

Wp specific methylation of highly proliferated LCLs

International Nuclear Information System (INIS)

Park, Jung-Hoon; Jeon, Jae-Pil; Shim, Sung-Mi; Nam, Hye-Young; Kim, Joon-Woo; Han, Bok-Ghee; Lee, Suman

2007-01-01

The epigenetic regulation of viral genes may be important for the life cycle of EBV. We determined the methylation status of three viral promoters (Wp, Cp, Qp) from EBV B-lymphoblastoid cell lines (LCLs) by pyrosequencing. Our pyrosequencing data showed that the CpG region of Wp was methylated, but the others were not. Interestingly, Wp methylation was increased with proliferation of LCLs. Wp methylation was as high as 74.9% in late-passage LCLs, but 25.6% in early-passage LCLs. From two Burkitt's lymphoma cell lines, Wp specific hypermethylation was also found (>80%). Interestingly, the expression of EBNA2 gene which located directly next to Wp was associated with its methylation. Our data suggested that Wp specific methylation may be important for the indicator of the proliferation status of LCLs, and the epigenetic viral gene regulation of EBNA2 gene by Wp should be further defined possibly with other biological processes

Environmental chemicals and DNA methylation in adults: a systematic review of the epidemiologic evidence

Science.gov (United States)

Current evidence supports the notion that environmental exposures are associated with DNA-methylation and expression changes that can impact human health. Our objective was to conduct a systematic review of epidemiologic studies evaluating the association between environmental chemicals with DNA met...

Biological effects of methyl and ethyl mercury compounds used as disinfectants for seed-grain on domestic and wild life

Energy Technology Data Exchange (ETDEWEB)

Tejning, S

1971-01-01

A short survey of the harmful effects of methyl and ethyl mercury on wild and domestic life and on man since the introduction of these compounds in plant protection is given. The biological effects of methyl mercury in birds are illustrated by experiments in hens concerning its accumulation in their organs and plumage, its elimination in eggs and excrements and its influence on the health of the birds, their laying habits and egg production including the occurrence of embryonic damages and the hatchability. Attention is drawn to the ability of methyl mercury to cause genetical disorders. 14 references, 1 figure, 1 table.

DNA Methylation Biomarkers: Cancer and Beyond

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Thomas Mikeska

2014-09-01

Full Text Available Biomarkers are naturally-occurring characteristics by which a particular pathological process or disease can be identified or monitored. They can reflect past environmental exposures, predict disease onset or course, or determine a patient’s response to therapy. Epigenetic changes are such characteristics, with most epigenetic biomarkers discovered to date based on the epigenetic mark of DNA methylation. Many tissue types are suitable for the discovery of DNA methylation biomarkers including cell-based samples such as blood and tumor material and cell-free DNA samples such as plasma. DNA methylation biomarkers with diagnostic, prognostic and predictive power are already in clinical trials or in a clinical setting for cancer. Outside cancer, strong evidence that complex disease originates in early life is opening up exciting new avenues for the detection of DNA methylation biomarkers for adverse early life environment and for estimation of future disease risk. However, there are a number of limitations to overcome before such biomarkers reach the clinic. Nevertheless, DNA methylation biomarkers have great potential to contribute to personalized medicine throughout life. We review the current state of play for DNA methylation biomarkers, discuss the barriers that must be crossed on the way to implementation in a clinical setting, and predict their future use for human disease.

Subsets of microsatellite-unstable colorectal cancers exhibit discordance between the CpG island methylator phenotype and MLH1 methylation status.

Science.gov (United States)

Kim, Jung H; Rhee, Ye-Y; Bae, Jeong-M; Kwon, Hyeong-J; Cho, Nam-Y; Kim, Mi J; Kang, Gyeong H

2013-07-01

Although the presence of MLH1 methylation in microsatellite-unstable colorectal cancer generally indicates involvement of the CpG island methylator phenotype (CIMP) in the development of the tumor, these two conditions do not always correlate. A minority of microsatellite-unstable colorectal cancers exhibit discordance between CIMP and MLH1 methylation statuses. However, the clinicopathological features of such microsatellite-unstable colorectal cancers with discrepant MLH1 methylation and CIMP statuses remain poorly studied. Microsatellite-unstable colorectal cancers (n=220) were analyzed for CIMP and MLH1 methylation statuses using the MethyLight assay. Based on the combinatorial CIMP and MLH1 methylation statuses, the microsatellite-unstable colorectal cancers were grouped into four subtypes (CIMP-high (CIMP-H) MLH1 methylation-positive (MLH1m+), CIMP-H MLH1 methylation-negative, CIMP-low/0 (CIMP-L/0) MLH1m+, and CIMP-L/0 MLH1 methylation-negative), which were compared in terms of their associations with clinicopathological and molecular features. The CIMP-L/0 MLH1 methylation-negative and CIMP-H MLH1m+ subtypes were predominant, comprising 63.6 and 24.1% of total microsatellite-unstable colorectal cancers, respectively. The discordant subtypes, CIMP-H MLH1 methylation-negative and CIMP-L/0 MLH1m+, were found in 5 and 7% of microsatellite-unstable colorectal cancers, respectively. The CIMP-H MLH1 methylation-negative subtype exhibited elevated incidence rates in male patients and was associated with larger tumor size, more frequent loss of MSH2 expression, increased frequency of KRAS mutation, and advanced cancer stage. The CIMP-L/0 MLH1m+ subtype was associated with onset at an earlier age, a predominance of MLH1 loss, and earlier cancer stage. None of the CIMP-L/0 MLH1m+ subtype patients succumbed to death during the follow-up. Our findings suggest that the discordant subtypes of colorectal cancers exhibit distinct clinicopathological and molecular features

The distribution of triclosan and methyl-triclosan in marine sediments of Barker Inlet, South Australia.

Science.gov (United States)

Fernandes, Milena; Shareef, Ali; Kookana, Rai; Gaylard, Sam; Hoare, Sonja; Kildea, Tim

2011-04-01

In this work, we investigated the transport and burial of triclosan and its methylated derivative, in surface sediments near the mouth of Barker Inlet in South Australia. The most likely source of this commonly used bactericide to the area is a wastewater outfall discharging at the confluence of the inlet with marine waters. Triclosan was detected in all samples, at concentrations (5-27 μg kg(-1)) comparable to values found in other surface sediments under the influence of marine wastewater outfalls. Its dispersal was closely associated with fine and organic-rich fractions of the sediments. Methyl-triclosan was detected in approximately half of the samples at concentrations compound was linked to both wastewater discharges and biological methylation of the parent compound. Wastewater-borne methyl-triclosan had a smaller spatial footprint than triclosan and was mostly deposited in close proximity to the outfall. In situ methylation of triclosan likely occurs at deeper depositional sites, whereas the absence of methyl-triclosan from shallower sediments was potentially explained by photodegradation of the parent compound. Based on partition equilibrium, a concentration of triclosan in the order of 1 μg L(-1) was estimated in sediment porewaters, a value lower than the threshold reported for harmful effects to occur in the couple of species of marine phytoplankton investigated to date. Methyl-triclosan presents a greater potential for bioaccumulation than triclosan, but the implications of its occurrence to aquatic ecosystem health are difficult to predict given the lack of ecotoxicological data in the current literature.

Production of Methyl Laurate from Coconut Cream through Fractionation of Methyl Ester

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Johnner P. Sitompul

2015-10-01

Full Text Available This paper concerns the production of methyl laurate from coconut cream through fractionation of methyl esters. Coconut oil was produced by wet processing of coconut cream. The esters were prepared by reacting coconut oil and methanol using homogeneous catalyst KOH in a batch reactor, followed by fractionation of fatty acid methyl esters (FAME at various reduced pressures applying differential batch vacuum distillation. Experimental data were compared with simulation of a batch distillation employing the simple Raoult’s model and modified Raoult’s model of phase equilibria. Activity coefficients (γi were determined by optimization to refine the models. The modified Rault’s model with activity coefficients gave better agreement with the experimental data, giving the value of γi between 0,56-0,73. For a given boiling temperature, lower operating pressure produced higher purity of C10 and C12 FAME for respective distillates.

Radiation effects on DNA methylation in mice

International Nuclear Information System (INIS)

Komura, J.; Kurishita, A.; Miyamura, Y.; Ono, T.; Tawa, R.; Sakurai, H.

1992-01-01

Effects of ionizing radiation on DNA methylation in liver, brain and spleen were examined by high performance liquid chromatography (HPLC). The total methylated cytosine level in the genome was reduced within 8 hours after 3.8 Gy of irradiation in liver of adult mice. But no appreciable effect was observed in brain and spleen. When mice were irradiated at newborn, liver DNA revealed no change in methylated cytosine level. Even though slight effects of radiation were detected in he methylation of the c-myc and c-fos genes, they were only temporary and no long-term effects were observed. These data suggest that the effect of radiation on DNA methylation in vivo is not prevailing a DNA damage, but rather influenced much through biological parameters. (author)

Methylation of ribonucleic acid by the carcinogens dimethyl sulphate, N-methyl-N-nitrosourea and N-methyl-N′-nitro-N-nitrosoguanidine. Comparisons of chemical analyses at the nucleoside and base levels

Science.gov (United States)

Lawley, P. D.; Shah, S. A.

1972-01-01

1. The following methods for hydrolysis of methyl-14C-labelled RNA, and for chromatographic isolation and determination of the products, were investigated: enzymic digestion to nucleosides at pH6 or 8; alkaline hydrolysis and conversion into nucleosides; hydrolysis by acid to pyrimidine nucleotides and purine bases, or completely to bases; chromatography on Dowex 50 (NH4+ form) at pH6 or 8.9, or on Dowex 50 (H+ form), or on Sephadex G-10. 2. The suitability of the various methods for determination of methylation products was assessed. The principal product, 7-methylguanosine, was unstable under the conditions used for determinations of nucleosides. 3- and 7-Methyladenine and 3- and 7-methylguanine are best determined as bases; 1-methyladenine and 3-methylcytosine can be isolated as either nucleosides or bases; O6-methylguanine is unstable under the acid hydrolysis conditions used and can be determined as the nucleoside; 3-methyluracil was detected, but may be derived from methylation of the ionized form of uracil. 3. Differences between the patterns of methylation of RNA and homopolyribonucleotides by the N-methyl-N-nitroso compounds and dimethyl sulphate were found: the nitroso compounds were able to methylate O-6 of guanine, were relatively more reactive at N-7 of adenine and probably at N-3 of guanine, but less reactive at N-1 of adenine, N-3 of cytosine and probably at N-3 of uridine. They probably reacted more with the ribose–phosphate chain, but no products from this were identified. 4. The possible influences of these differences on biological action of the methylating agents is discussed. Nitroso compounds may differ principally in their ability to induce miscoding in the Watson–Crick sense by reaction at O-6 of guanine. Both types of agent may induce miscoding to a lesser extent through methylation at N-3 of guanine; both can methylate N atoms, presumably preventing Watson–Crick hydrogen-bonding. N-Methyl-N-nitrosourea can degrade RNA, possibly

Methyl group turnover on methyl-accepting chemotaxis proteins during chemotaxis by Bacillus subtilis

International Nuclear Information System (INIS)

Thoelke, M.S.; Casper, J.M.; Ordal, G.W.

1990-01-01

The addition of attractant to Bacillus subtilis briefly exposed to radioactive methionine causes an increase of labeling of the methyl-accepting chemotaxis proteins. The addition of attractant to cells radiolabeled for longer times shows no change in the extent of methylation. Therefore, the increase in labeling for the briefly labeled cells is due to an increased turnover of methyl groups caused by attractant. All amino acids gave enhanced turnover. This turnover lasted for a prolonged time, probably spanning the period of smooth swimming caused by the attractant addition. Repellent did not affect the turnover when added alone or simultaneously with attractant. Thus, for amino acid attractants, the turnover is probably the excitatory signal, which is seen to extend long into or throughout the adaptation period, not just at the start of it

Modulation of histone methylation and MLH1 gene silencing by hexavalent chromium

International Nuclear Information System (INIS)

Sun Hong; Zhou Xue; Chen Haobin; Li Qin; Costa, Max

2009-01-01

Hexavalent chromium [Cr(VI)] is a mutagen and carcinogen, and occupational exposure can lead to lung cancers and other adverse health effects. Genetic changes resulting from DNA damage have been proposed as an important mechanism that mediates chromate's carcinogenicity. Here we show that chromate exposure of human lung A549 cells increased global levels of di- and tri-methylated histone H3 lysine 9 (H3K9) and lysine 4 (H3K4) but decreased the levels of tri-methylated histone H3 lysine 27 (H3K27) and di-methylated histone H3 arginine 2 (H3R2). Most interestingly, H3K9 dimethylation was enriched in the human MLH1 gene promoter following chromate exposure and this was correlated with decreased MLH1 mRNA expression. Chromate exposure increased the protein as well as mRNA levels of G9a a histone methyltransferase that specifically methylates H3K9. This Cr(VI)-induced increase in G9a may account for the global elevation of H3K9 dimethylation. Furthermore, supplementation with ascorbate, the primary reductant of Cr(VI) and also an essential cofactor for the histone demethylase activity, partially reversed the H3K9 dimethylation induced by chromate. Thus our studies suggest that Cr(VI) may target histone methyltransferases and demethylases, which in turn affect both global and gene promoter specific histone methylation, leading to the silencing of specific tumor suppressor genes such as MLH1.

Transcription factors as readers and effectors of DNA methylation.

Science.gov (United States)

Zhu, Heng; Wang, Guohua; Qian, Jiang

2016-08-01

Recent technological advances have made it possible to decode DNA methylomes at single-base-pair resolution under various physiological conditions. Many aberrant or differentially methylated sites have been discovered, but the mechanisms by which changes in DNA methylation lead to observed phenotypes, such as cancer, remain elusive. The classical view of methylation-mediated protein-DNA interactions is that only proteins with a methyl-CpG binding domain (MBD) can interact with methylated DNA. However, evidence is emerging to suggest that transcription factors lacking a MBD can also interact with methylated DNA. The identification of these proteins and the elucidation of their characteristics and the biological consequences of methylation-dependent transcription factor-DNA interactions are important stepping stones towards a mechanistic understanding of methylation-mediated biological processes, which have crucial implications for human development and disease.

RlmCD-mediated U747 methylation promotes efficient G748 methylation by methyltransferase RlmAII in 23S rRNA in Streptococcus pneumoniae; interplay between two rRNA methylations responsible for telithromycin susceptibility.

Science.gov (United States)

Shoji, Tatsuma; Takaya, Akiko; Sato, Yoshiharu; Kimura, Satoshi; Suzuki, Tsutomu; Yamamoto, Tomoko

2015-10-15

Adenine at position 752 in a loop of helix 35 from positions 745 to 752 in domain II of 23S rRNA is involved in binding to the ribosome of telithromycin (TEL), a member of ketolides. Methylation of guanine at position 748 by the intrinsic methyltransferase RlmA(II) enhances binding of telithromycin (TEL) to A752 in Streptococcus pneumoniae. We have found that another intrinsic methylation of the adjacent uridine at position 747 enhances G748 methylation by RlmA(II), rendering TEL susceptibility. U747 and another nucleotide, U1939, were methylated by the dual-specific methyltransferase RlmCD encoded by SP_1029 in S. pneumoniae. Inactivation of RlmCD reduced N1-methylated level of G748 by RlmA(II) in vivo, leading to TEL resistance when the nucleotide A2058, located in domain V of 23S rRNA, was dimethylated by the dimethyltransferase Erm(B). In vitro methylation of rRNA showed that RlmA(II) activity was significantly enhanced by RlmCD-mediated pre-methylation of 23S rRNA. These results suggest that RlmCD-mediated U747 methylation promotes efficient G748 methylation by RlmA(II), thereby facilitating TEL binding to the ribosome. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Dynamic Alu Methylation during Normal Development, Aging, and Tumorigenesis

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Yanting Luo

2014-01-01

Full Text Available DNA methylation primarily occurs on CpG dinucleotides and plays an important role in transcriptional regulations during tissue development and cell differentiation. Over 25% of CpG dinucleotides in the human genome reside within Alu elements, the most abundant human repeats. The methylation of Alu elements is an important mechanism to suppress Alu transcription and subsequent retrotransposition. Decades of studies revealed that Alu methylation is highly dynamic during early development and aging. Recently, many environmental factors were shown to have a great impact on Alu methylation. In addition, aberrant Alu methylation has been documented to be an early event in many tumors and Alu methylation levels have been associated with tumor aggressiveness. The assessment of the Alu methylation has become an important approach for early diagnosis and/or prognosis of cancer. This review focuses on the dynamic Alu methylation during development, aging, and tumor genesis. The cause and consequence of Alu methylation changes will be discussed.

Human Cell Line Activation Test of the Novel Energetics Methyl Trinitropryrazol (MTNP) and 1,3-Dimethylhexahydropyrimidine (DHP)

Science.gov (United States)

2017-11-01

costs, conserve physical resources, and sustain the health of those potentially exposed. The U.S. Army RDECOM, ETAP has been dedicated to finding...trinitropryrazol (MTNP) and 1,3-dimethylhexahydropyrimidine (DHP) Prepared by: Emily Reinke, Ph.D. Health Effects Division Toxicology...the Novel Energetics methyl trinitropyrazol (MTNP) and 1,3-dimethylhexahydropyrimidine (DHP) Emily N. Reinke, Ph.D. Army Public Health Center

Annotating the genome by DNA methylation.

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Cedar, Howard; Razin, Aharon

2017-01-01

DNA methylation plays a prominent role in setting up and stabilizing the molecular design of gene regulation and by understanding this process one gains profound insight into the underlying biology of mammals. In this article, we trace the discoveries that provided the foundations of this field, starting with the mapping of methyl groups in the genome and the experiments that helped clarify how methylation patterns are maintained through cell division. We then address the basic relationship between methyl groups and gene repression, as well as the molecular rules involved in controlling this process during development in vivo. Finally, we describe ongoing work aimed at defining the role of this modification in disease and deciphering how it may serve as a mechanism for sensing the environment.

Analysis of DNA methylation of maize in response to osmotic and salt stress based on methylation-sensitive amplified polymorphism.

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Tan, Ming-pu

2010-01-01

Water stress is known to alter cytosine methylation, which generally represses transcription. However, little is known about the role of methylation alteration in maize under osmotic stress. Here, methylation-sensitive amplified polymorphism (MSAP) was used to screen PEG- or NaCl-induced methylation alteration in maize seedlings. The sequences of 25 differentially amplified fragments relevant to stress were successfully obtained. Two stress-specific fragments from leaves, LP166 and LPS911, shown to be homologous to retrotransposon Gag-Pol protein genes, suggested that osmotic stress-induced methylation of retrotransposons. Three MSAP fragments, representing drought-induced or salt-induced methylation in leaves, were homologous to a maize aluminum-induced transporter. Besides these, heat shock protein HSP82, Poly [ADP-ribose] polymerase 2, Lipoxygenase, casein kinase (CK2), and dehydration-responsive element-binding (DREB) factor were also homologs of MSAP sequences from salt-treated roots. One MSAP fragment amplified from salt-treated roots, designated RS39, was homologous to the first intron of maize protein phosphatase 2C (zmPP2C), whereas - LS103, absent from salt-treated leaves, was homologous to maize glutathione S-transferases (zmGST). Expression analysis showed that salt-induced intron methylation of root zmPP2C significantly downregulated its expression, while salt-induced demethylation of leaf zmGST weakly upregulated its expression. The results suggested that salinity-induced methylation downregulated zmPP2C expression, a negative regulator of the stress response, while salinity-induced demethylation upregulated zmGST expression, a positive effecter of the stress response. Altered methylation, in response to stress, might also be involved in stress acclimation. Copyright 2009 Elsevier Masson SAS. All rights reserved.

DNA methylation in obesity

Directory of Open Access Journals (Sweden)

Małgorzata Pokrywka

2014-11-01

Full Text Available The number of overweight and obese people is increasing at an alarming rate, especially in the developed and developing countries. Obesity is a major risk factor for diabetes, cardiovascular disease, and cancer, and in consequence for premature death. The development of obesity results from the interplay of both genetic and environmental factors, which include sedentary life style and abnormal eating habits. In the past few years a number of events accompanying obesity, affecting expression of genes which are not directly connected with the DNA base sequence (e.g. epigenetic changes, have been described. Epigenetic processes include DNA methylation, histone modifications such as acetylation, methylation, phosphorylation, ubiquitination, and sumoylation, as well as non-coding micro-RNA (miRNA synthesis. In this review, the known changes in the profile of DNA methylation as a factor affecting obesity and its complications are described.

Methylation-Sensitive High Resolution Melting (MS-HRM).

Science.gov (United States)

Hussmann, Dianna; Hansen, Lise Lotte

2018-01-01

Methylation-Sensitive High Resolution Melting (MS-HRM) is an in-tube, PCR-based method to detect methylation levels at specific loci of interest. A unique primer design facilitates a high sensitivity of the assays enabling detection of down to 0.1-1% methylated alleles in an unmethylated background.Primers for MS-HRM assays are designed to be complementary to the methylated allele, and a specific annealing temperature enables these primers to anneal both to the methylated and the unmethylated alleles thereby increasing the sensitivity of the assays. Bisulfite treatment of the DNA prior to performing MS-HRM ensures a different base composition between methylated and unmethylated DNA, which is used to separate the resulting amplicons by high resolution melting.The high sensitivity of MS-HRM has proven useful for detecting cancer biomarkers in a noninvasive manner in urine from bladder cancer patients, in stool from colorectal cancer patients, and in buccal mucosa from breast cancer patients. MS-HRM is a fast method to diagnose imprinted diseases and to clinically validate results from whole-epigenome studies. The ability to detect few copies of methylated DNA makes MS-HRM a key player in the quest for establishing links between environmental exposure, epigenetic changes, and disease.

Heterogeneity of DNA methylation in multifocal prostate cancer.

Science.gov (United States)

Serenaite, Inga; Daniunaite, Kristina; Jankevicius, Feliksas; Laurinavicius, Arvydas; Petroska, Donatas; Lazutka, Juozas R; Jarmalaite, Sonata

2015-01-01

Most prostate cancer (PCa) cases are multifocal, and separate foci display histological and molecular heterogeneity. DNA hypermethylation is a frequent alteration in PCa, but interfocal heterogeneity of these changes has not been extensively investigated. Ten pairs of foci from multifocal PCa and 15 benign prostatic hyperplasia (BPH) samples were obtained from prostatectomy specimens, resulting altogether in 35 samples. Methylation-specific PCR (MSP) was used to evaluate methylation status of nine tumor suppressor genes (TSGs), and a set of selected TSGs was quantitatively analyzed for methylation intensity by pyrosequencing. Promoter sequences of the RASSF1 and ESR1 genes were methylated in all paired PCa foci, and frequent (≥75 %) DNA methylation was detected in RARB, GSTP1, and ABCB1 genes. MSP revealed different methylation status of at least one gene in separate foci in 8 out of 10 multifocal tumors. The mean methylation level of ESR1, GSTP1, RASSF1, and RARB differed between the paired foci of all PCa cases. The intensity of DNA methylation in these TSGs was significantly higher in PCa cases than in BPH (p epigenetic profile of recurrent tumors can be inferred from our data.

Methylated genes as new cancer biomarkers

DEFF Research Database (Denmark)

Brunner, Nils; Duffy, M.J; Napieralski, R.

2009-01-01

Aberrant hypermethylation of promoter regions in specific genes is a key event in the formation and progression of cancer. In at least some situations, these aberrant alterations occur early in the formation of malignancy and appear to be tumour specific. Multiple reports have suggested that meas......Aberrant hypermethylation of promoter regions in specific genes is a key event in the formation and progression of cancer. In at least some situations, these aberrant alterations occur early in the formation of malignancy and appear to be tumour specific. Multiple reports have suggested...... that measurement of the methylation status of the promoter regions of specific genes can aid early detection of cancer, determine prognosis and predict therapy responses. Promising DNA methylation biomarkers include the use of methylated GSTP1 for aiding the early diagnosis of prostate cancer, methylated PITX2...... for predicting outcome in lymph node-negative breast cancer patients and methylated MGMT in predicting benefit from alkylating agents in patients with glioblastomas. However, prior to clinical utilisation, these findings require validation in prospective clinical studies. Furthermore, assays for measuring gene...

Methylated spirit burns: an ongoing problem.

Science.gov (United States)

Jansbeken, J R H; Vloemans, A F P M; Tempelman, F R H; Breederveld, R S

2012-09-01

Despite many educational campaigns we still see burns caused by methylated spirit every year. We undertook a retrospective study to analyse the impact of this problem. We retrospectively collected data of all patients with burns caused by methylated spirit over twelve years from 1996 to 2008. Our main endpoints were: incidence, age, mechanism of injury, total body surface area (TBSA) burned, burn depth, need for surgery and length of hospital stay. Ninety-seven patients with methylated spirit burns were included. During the study period there was no decrease in the number of patients annually admitted to the burn unit with methylated spirit burns. 28% of the patients (n=27) were younger than eighteen years old, 15% (n=15) were ten years old or younger. The most common cause of burns was carelessness in activities involving barbecues, campfires and fondues. Mean TBSA burned was 16% (SD 12.4). 70% (n=68) had full thickness burns. 66% (n=64) needed grafting. Mean length of hospital stay was 23 days (SD 24.7). The use of methylated spirit is an ongoing problem, which continues to cause severe burns in adults and children. Therefore methylated spirit should be banned in households. We suggest sale only in specialised shops, clear labelling and mandatory warnings. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

Accounting for Life-Course Exposures in Epigenetic Biomarker Association Studies: Early Life Socioeconomic Position, Candidate Gene DNA Methylation, and Adult Cardiometabolic Risk.

Science.gov (United States)

Huang, Jonathan Y; Gavin, Amelia R; Richardson, Thomas S; Rowhani-Rahbar, Ali; Siscovick, David S; Hochner, Hagit; Friedlander, Yechiel; Enquobahrie, Daniel A

2016-10-01

Recent studies suggest that epigenetic programming may mediate the relationship between early life environment, including parental socioeconomic position, and adult cardiometabolic health. However, interpreting associations between early environment and adult DNA methylation may be difficult because of time-dependent confounding by life-course exposures. Among 613 adult women (mean age = 32 years) of the Jerusalem Perinatal Study Family Follow-up (2007-2009), we investigated associations between early life socioeconomic position (paternal occupation and parental education) and mean adult DNA methylation at 5 frequently studied cardiometabolic and stress-response genes (ABCA1, INS-IGF2, LEP, HSD11B2, and NR3C1). We used multivariable linear regression and marginal structural models to estimate associations under 2 causal structures for life-course exposures and timing of methylation measurement. We also examined whether methylation was associated with adult cardiometabolic phenotype. Higher maternal education was consistently associated with higher HSD11B2 methylation (e.g., 0.5%-point higher in 9-12 years vs. ≤8 years, 95% confidence interval: 0.1, 0.8). Higher HSD11B2 methylation was also associated with lower adult weight and total and low-density lipoprotein cholesterol. We found that associations with early life socioeconomic position measures were insensitive to different causal assumption; however, exploratory analysis did not find evidence for a mediating role of methylation in socioeconomic position-cardiometabolic risk associations. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Absolute photoionization cross-section of the methyl radical.

Science.gov (United States)

Taatjes, Craig A; Osborn, David L; Selby, Talitha M; Meloni, Giovanni; Fan, Haiyan; Pratt, Stephen T

2008-10-02

The absolute photoionization cross-section of the methyl radical has been measured using two completely independent methods. The CH3 photoionization cross-section was determined relative to that of acetone and methyl vinyl ketone at photon energies of 10.2 and 11.0 eV by using a pulsed laser-photolysis/time-resolved synchrotron photoionization mass spectrometry method. The time-resolved depletion of the acetone or methyl vinyl ketone precursor and the production of methyl radicals following 193 nm photolysis are monitored simultaneously by using time-resolved synchrotron photoionization mass spectrometry. Comparison of the initial methyl signal with the decrease in precursor signal, in combination with previously measured absolute photoionization cross-sections of the precursors, yields the absolute photoionization cross-section of the methyl radical; sigma(CH3)(10.2 eV) = (5.7 +/- 0.9) x 10(-18) cm(2) and sigma(CH3)(11.0 eV) = (6.0 +/- 2.0) x 10(-18) cm(2). The photoionization cross-section for vinyl radical determined by photolysis of methyl vinyl ketone is in good agreement with previous measurements. The methyl radical photoionization cross-section was also independently measured relative to that of the iodine atom by comparison of ionization signals from CH3 and I fragments following 266 nm photolysis of methyl iodide in a molecular-beam ion-imaging apparatus. These measurements gave a cross-section of (5.4 +/- 2.0) x 10(-18) cm(2) at 10.460 eV, (5.5 +/- 2.0) x 10(-18) cm(2) at 10.466 eV, and (4.9 +/- 2.0) x 10(-18) cm(2) at 10.471 eV. The measurements allow relative photoionization efficiency spectra of methyl radical to be placed on an absolute scale and will facilitate quantitative measurements of methyl concentrations by photoionization mass spectrometry.

Fate and persistence of 14C pesticide residues in different soils: effects of 14C pesticide contaminated run-off soil water on biological systems. Part of a coordinated programme on isotopic-tracer-aided studies of agrochemical residue - soil biota interactions

International Nuclear Information System (INIS)

Lichtenstein, E.

1982-09-01

The interaction of selected fungicides, herbicides and N-fertilizers with microorganisms in cranberry soils and their effects on the degradation of 14 C-phenyl-parathion were investigated. Incubation of soils with parathion of p-nitrophenol for 4 days, followed by the addition of 14 C-parathion resulted after 24 h in an enhanced degradation of the insecticide to 14 CO 2 (34-39% of the applied radiocarbon as opposed to 2% in controls) and also in an increased binding of 14 C to the soil. The fungicide captafol inhibited the degradation of soil-applied 14 C-parathion as evidenced by a reduction of both 14 CO 2 evolution and 14 C-bound residues. Maneb and benomyl suppressed the degradation of 14 C-parathion to 14 CO 2 but not the formation of bound residues. Addition of 2,4-D to 14 C-parathion treated soil also resulted in an increased persistence of the insecticide. Studies conducted with the insecticide and (NH 4 ) 2 SO 4 , NH 4 NO 3 , KNO 3 or urea showed that under all experimental conditions the total amounts of 14 C recovered were similar, yet the distribution of 14 C-compounds into benzene-soluble, water-soluble and bound residues was not. This possibly indicated a change in the pathway of 14 C-parathion degradation. The insecticide was most persistent in soils containing (NH 4 ) 2 SO 4 , as demonstrated by a recovery of 29% of the applied radiocarbon in benzene-soluble form. Analyses by TIC of this benzene extraction phase revealed the presence of 14 C-parathion, 14 C-p-aminophenol and 14 C-aminoparathion

Methyl Iodide Decomposition at BWR Conditions

International Nuclear Information System (INIS)

Pop, Mike; Bell, Merl

2012-09-01

Based on favourable results from short-term testing of methanol addition to an operating BWR plant, AREVA has performed numerous studies in support of necessary Engineering and Plant Safety Evaluations prior to extended injection of methanol. The current paper presents data from a study intended to provide further understanding of the decomposition of methyl iodide as it affects the assessment of methyl iodide formation with the application of methanol at BWR Plants. This paper describes the results of the decomposition testing under UV-C light at laboratory conditions and its effect on the subject methyl iodide production evaluation. The study as to the formation and decomposition of methyl iodide as it is effected by methanol addition is one phase of a larger AREVA effort to provide a generic plant Safety Evaluation prior to long-term methanol injection to an operating BWR. Other testing phases have investigated the compatibility of methanol with fuel construction materials, plant structural materials, plant consumable materials (i.e. elastomers and coatings), and ion exchange resins. Methyl iodide is known to be very unstable, typically preserved with copper metal or other stabilizing materials when produced and stored. It is even more unstable when exposed to light, heat, radiation, and water. Additionally, it is known that methyl iodide will decompose radiolytically, and that this effect may be simulated using ultra-violet radiation (UV-C) [2]. In the tests described in this paper, the use of a UV-C light source provides activation energy for the formation of methyl iodide. Thus is similar to the effect expected from Cherenkov radiation present in a reactor core after shutdown. Based on the testing described in this paper, it is concluded that injection of methanol at concentrations below 2.5 ppm in BWR applications to mitigate IGSCC of internals is inconsequential to the accident conditions postulated in the FSAR as they are related to methyl iodide formation

Homogalacturonan methyl-esterification and plant development.

Science.gov (United States)

Wolf, Sebastian; Mouille, Grégory; Pelloux, Jérome

2009-09-01

The ability of a plant cell to expand is largely defined by the physical constraints imposed by its cell wall. Accordingly, cell wall properties have to be regulated during development. The pectic polysaccharide homogalacturonan is a major component of the plant primary walls. Biosynthesis and in muro modification of homogalacturonan have recently emerged as key determinants of plant development, controlling cell adhesion, organ development, and phyllotactic patterning. This review will focus on recent findings regarding impact of homogalacturonan content and methyl-esterification status of this polymer on plant life. De-methyl-esterification of homogalacturonan occurs through the action of the ubiquitous enzyme 'pectin methyl-esterase'. We here describe various strategies developed by the plant to finely tune the methyl-esterification status of homogalacturonan along key events of the plant lifecycle.

Analysis of DNA methylation related to rice adult plant resistance to bacterial blight based on methylation-sensitive AFLP (MSAP) analysis.

Science.gov (United States)

Sha, A H; Lin, X H; Huang, J B; Zhang, D P

2005-07-01

DNA methylation is known to play an important role in the regulation of gene expression in eukaryotes. The rice cultivar Wase Aikoku 3 becomes resistant to the blight pathogen Xanthomonas oryzae pv. oryzae at the adult stage. Using methylation-sensitive amplified polymorphism (MSAP) analysis, we compared the patterns of cytosine methylation in seedlings and adult plants of the rice cultivar Wase Aikoku 3 that had been inoculated with the pathogen Xanthomonas oryzae pv. oryzae, subjected to mock inoculation or left untreated. In all, 2000 DNA fragments, each representing a recognition site cleaved by either or both of two isoschizomers, were amplified using 60 pairs of selective primers. A total of 380 sites were found to be methylated. Of these, 45 showed differential cytosine methylation among the seedlings and adult plants subjected to different treatments, and overall levels of methylation were higher in adult plants than in seedlings. All polymorphic fragments were sequenced, and six showed homology to genes that code for products of known function. Northern analysis of three fragments indicated that their expression varied with methylation pattern, with hypermethylation being correlated with repression of transcription, as expected. The results suggest that significant differences in cytosine methylation exist between seedlings and adult plants, and that hypermethylation or hypomethylation of specific genes may be involved in the development of adult plant resistance (APR) in rice plants.

Search for methylation-sensitive amplification polymorphisms in mutant figs.

Science.gov (United States)

Rodrigues, M G F; Martins, A B G; Bertoni, B W; Figueira, A; Giuliatti, S

2013-07-08

Fig (Ficus carica) breeding programs that use conventional approaches to develop new cultivars are rare, owing to limited genetic variability and the difficulty in obtaining plants via gamete fusion. Cytosine methylation in plants leads to gene repression, thereby affecting transcription without changing the DNA sequence. Previous studies using random amplification of polymorphic DNA and amplified fragment length polymorphism markers revealed no polymorphisms among select fig mutants that originated from gamma-irradiated buds. Therefore, we conducted methylation-sensitive amplified polymorphism analysis to verify the existence of variability due to epigenetic DNA methylation among these mutant selections compared to the main cultivar 'Roxo-de-Valinhos'. Samples of genomic DNA were double-digested with either HpaII (methylation sensitive) or MspI (methylation insensitive) and with EcoRI. Fourteen primer combinations were tested, and on an average, non-methylated CCGG, symmetrically methylated CmCGG, and hemimethylated hmCCGG sites accounted for 87.9, 10.1, and 2.0%, respectively. MSAP analysis was effective in detecting differentially methylated sites in the genomic DNA of fig mutants, and methylation may be responsible for the phenotypic variation between treatments. Further analyses such as polymorphic DNA sequencing are necessary to validate these differences, standardize the regions of methylation, and analyze reads using bioinformatic tools.

Automated sequence- and stereo-specific assignment of methyl-labeled proteins by paramagnetic relaxation and methyl–methyl nuclear overhauser enhancement spectroscopy

International Nuclear Information System (INIS)

Venditti, Vincenzo; Fawzi, Nicolas L.; Clore, G. Marius

2011-01-01

Methyl-transverse relaxation optimized spectroscopy is rapidly becoming the preferred NMR technique for probing structure and dynamics of very large proteins up to ∼1 MDa in molecular size. Data interpretation, however, necessitates assignment of methyl groups which still presents a very challenging and time-consuming process. Here we demonstrate that, in combination with a known 3D structure, paramagnetic relaxation enhancement (PRE), induced by nitroxide spin-labels incorporated at only a few surface-exposed engineered cysteines, provides fast, straightforward and robust access to methyl group resonance assignments, including stereoassignments for the methyl groups of leucine and valine. Neither prior assignments, including backbone assignments, for the protein, nor experiments that transfer magnetization between methyl groups and the protein backbone, are required. PRE-derived assignments are refined by 4D methyl–methyl nuclear Overhauser enhancement data, eliminating ambiguities and errors that may arise due to the high sensitivity of PREs to the potential presence of sparsely-populated transient states.

Theoretical spectroscopic characterization at low temperatures of S-methyl thioformate and O-methyl thioformate

International Nuclear Information System (INIS)

Senent, M. L.; Puzzarini, C.; Hochlaf, M.; Domínguez-Gómez, R.; Carvajal, M.

2014-01-01

Highly correlated ab initio methods are employed to determine spectroscopic properties at low temperatures of two S-analogs of methyl formate: S-methyl thioformate CH 3 -S-CHO (MSCHO) and O-methyl thioformate CH 3 -O-CHS (MOCHS). Both species are detectable and they are expected to play an important role in Astrochemistry. Molecular properties are compared with those of the O-analog, methyl formate. Both isomers present two conformers cis and trans. cis-CH 3 -S-CHO represents the most stable structure lying 4372.2 cm −1 below cis-CH 3 -O-CHS. The energy difference between the cis and trans forms is drastically lower for MSCHO (1134 cm −1 ) than for MOCHS (1963.6 cm −1 ). Harmonic and anharmonic fundamentals and the corresponding intensities, as well as the rotational constants for the ground vibrational and first excited torsional states and the centrifugal distortions constants, are provided. Low torsional energy levels have been obtained by solving variationally a two dimensional Hamiltonian expressed in terms of the two torsional degrees of freedom. The corresponding 2D potential energy surfaces have been computed at the CCSD(T)/aug-cc-pVTZ level of theory. The methyl torsional barriers V 3 (cis) are determined to be 139.7 cm −1 (CH 3 -S-CHO) and 670.4 cm −1 (CH 3 -O-CHS). The A/E splitting of ground torsional state has been estimated to be 0.438 cm −1 for CH 3 -S-CHO and negligible for CH 3 -O-CHS

miRNAting control of DNA methylation

Indian Academy of Sciences (India)

miRNAting control of DNA methylation. ASHWANI ... function and biological process ... Enrichment analysis of the genes methylated by DRM2 for molecular function and biological ... 39(3), June 2014, 365–380, © Indian Academy of Sciences.

Allele-Specific DNA Methylation Detection by Pyrosequencing®

DEFF Research Database (Denmark)

Kristensen, Lasse Sommer; Johansen, Jens Vilstrup; Grønbæk, Kirsten

2015-01-01

DNA methylation is an epigenetic modification that plays important roles in healthy as well as diseased cells, by influencing the transcription of genes. In spite the fact that human somatic cells are diploid, most of the currently available methods for the study of DNA methylation do not provide......-effective protocol for allele-specific DNA methylation detection based on Pyrosequencing(®) of methylation-specific PCR (MSP) products including a single nucleotide polymorphism (SNP) within the amplicon....

Lethal and sublethal effects of selected insecticides and an insect growth regulator on the boll weevil (Coleoptera: Curculionidae) ectoparasitoid Catolaccus grandis (Hymenoptera: Pteromalidae).

Science.gov (United States)

Elzen, G W; Maldonado, S N; Rojas, M G

2000-04-01

A laboratory culture of Catolaccus grandis (Burks), an ectoparasitoid of the boll weevil, Anthonomus grandis grandis Boheman, was exposed to lethal and sublethal doses of insecticides and an insect growth regulator using a spray chamber bioassay. Materials tested were azinphos-methyl, endosulfan, fipronil, malathion, cyfluthrin, dimethoate, spinosad, methyl parathion, acephate, oxamyl, and tebufenozide. At full rates, spinosad was significantly less toxic to female C. grandis than other treatments except endosulfan. Fipronil and malathion were significantly more toxic to females than other treatments. Most of the chemicals tested were highly toxic to male C. grandis; spinosad was least toxic. At reduced rates, most of 4 selected chemicals tested were low in toxicity to C. grandis; however, a reduced rate of malathion was significantly more toxic to females than other treatments. No C. grandis pupae developed from parasitism during a 24-h treatment period with malathion or spinosad. The sex ratio of progeny from sprayed adults appeared to be unaffected by the treatments.

Methods for measuring specific rates of mercury methylation and degradation and their use in determining factors controlling net rates of mercury methylation

International Nuclear Information System (INIS)

Ramlal, P.S.; Rudd, J.W.M.; Hecky, R.E.

1986-01-01

A method was developed to estimate specific rates of demethylation of methyl mercury in aquatic samples by measuring the volatile 14 C end products of 14 CH 3 HgI demethylation. This method was used in conjuction with a 203 Hg 2+ radiochemical method which determines specific rates of mercury methylation. Together, these methods enabled us to examine some factors controlling the net rate of mercury methylation. The methodologies were field tested, using lake sediment samples from a recently flooded reservoir in the Southern Indian Lake system which had developed a mercury contamination problem in fish. Ratios of the specific rates of methylation/demethylation were calculated. The highest ratios of methylation/demethylation were calculated. The highest ratios of methylation/demethylation occurred in the flooded shorelines of Southern Indian Lake. These results provide an explanation for the observed increases in the methyl mercury concentrations in fish after flooding

Consumption study and identification of methyl salicylate in spicy cassava chips

International Nuclear Information System (INIS)

Nirjana, Marlene; Anggadiredja, Kusnandar; Damayanti, Sophi

2015-01-01

Spicy cassava chips is a popular snack. However, some news in electronic media reported addition of balsam which is a banned food additives in that product to give extra spicy flavor. This study aimed to determine ITB students’ pattern of consumption, health problems caused by spicy chips consumption, and knowledge about illicit use of food additives in that product, and identify the main content of balsam namely methyl salicylate in 10 samples of spicy cassava chips taken from inside and outside about ITB campus. A total of 300 questionnaires distributed to ITB students then data processing was performed. Spicy cassava chips sample macerated in 50 mL of methanol for 24 hours at room temperature, filtered and analyzed using gas chromatography capillary column with OV-1, nitrogen carrier gas and flame ionization detector. Based on questionnaires, 292 (97%) of 300 respondents had consumed spicy chips. A total of 247 (85%) from 292 respondents spicy chips consumed less than 3 times a week. A total of 195 respondents (67%) had experienced health problems after eating spicy chips. There were 137 (47%) of the 292 respondents who knew about the illicit addition of food additives into spicy chips; only 35 respondents (12%) who knew about balsam’s addition. There were 126 respondents (43%) who did not pay attention to their health because they will keep eating spicy chips despite the addition of banned food additives. Through the verification of the standard addition method in gas chromatography system with a hydrogen pressure of 1.5 bar, injector temperature 200 °C, detector temperature 230 °C, oven temperature 60 °C for 2 minutes and then increased to 230 °C with rate 6 °C/menit; linearity, limit of detection, limit of quantitation, accuracy, precision, and specificity parameters met the acceptance limits. From 10 spicy cassava chips samples which were analyzed, they did not reveal any content of methyl salicylate. Methyl salicylate contained in the positive

Consumption study and identification of methyl salicylate in spicy cassava chips

Energy Technology Data Exchange (ETDEWEB)

Nirjana, Marlene, E-mail: marlenenirjana@gmail.com; Anggadiredja, Kusnandar; Damayanti, Sophi [School of Pharmacy, Institut Teknologi Bandung Jalan Ganesha 10, Bandung 40132 (Indonesia)

2015-09-30

Spicy cassava chips is a popular snack. However, some news in electronic media reported addition of balsam which is a banned food additives in that product to give extra spicy flavor. This study aimed to determine ITB students’ pattern of consumption, health problems caused by spicy chips consumption, and knowledge about illicit use of food additives in that product, and identify the main content of balsam namely methyl salicylate in 10 samples of spicy cassava chips taken from inside and outside about ITB campus. A total of 300 questionnaires distributed to ITB students then data processing was performed. Spicy cassava chips sample macerated in 50 mL of methanol for 24 hours at room temperature, filtered and analyzed using gas chromatography capillary column with OV-1, nitrogen carrier gas and flame ionization detector. Based on questionnaires, 292 (97%) of 300 respondents had consumed spicy chips. A total of 247 (85%) from 292 respondents spicy chips consumed less than 3 times a week. A total of 195 respondents (67%) had experienced health problems after eating spicy chips. There were 137 (47%) of the 292 respondents who knew about the illicit addition of food additives into spicy chips; only 35 respondents (12%) who knew about balsam’s addition. There were 126 respondents (43%) who did not pay attention to their health because they will keep eating spicy chips despite the addition of banned food additives. Through the verification of the standard addition method in gas chromatography system with a hydrogen pressure of 1.5 bar, injector temperature 200 °C, detector temperature 230 °C, oven temperature 60 °C for 2 minutes and then increased to 230 °C with rate 6 °C/menit; linearity, limit of detection, limit of quantitation, accuracy, precision, and specificity parameters met the acceptance limits. From 10 spicy cassava chips samples which were analyzed, they did not reveal any content of methyl salicylate. Methyl salicylate contained in the positive

Consumption study and identification of methyl salicylate in spicy cassava chips

Science.gov (United States)

Nirjana, Marlene; Anggadiredja, Kusnandar; Damayanti, Sophi

2015-09-01

Spicy cassava chips is a popular snack. However, some news in electronic media reported addition of balsam which is a banned food additives in that product to give extra spicy flavor. This study aimed to determine ITB students' pattern of consumption, health problems caused by spicy chips consumption, and knowledge about illicit use of food additives in that product, and identify the main content of balsam namely methyl salicylate in 10 samples of spicy cassava chips taken from inside and outside about ITB campus. A total of 300 questionnaires distributed to ITB students then data processing was performed. Spicy cassava chips sample macerated in 50 mL of methanol for 24 hours at room temperature, filtered and analyzed using gas chromatography capillary column with OV-1, nitrogen carrier gas and flame ionization detector. Based on questionnaires, 292 (97%) of 300 respondents had consumed spicy chips. A total of 247 (85%) from 292 respondents spicy chips consumed less than 3 times a week. A total of 195 respondents (67%) had experienced health problems after eating spicy chips. There were 137 (47%) of the 292 respondents who knew about the illicit addition of food additives into spicy chips; only 35 respondents (12%) who knew about balsam's addition. There were 126 respondents (43%) who did not pay attention to their health because they will keep eating spicy chips despite the addition of banned food additives. Through the verification of the standard addition method in gas chromatography system with a hydrogen pressure of 1.5 bar, injector temperature 200 °C, detector temperature 230 °C, oven temperature 60 °C for 2 minutes and then increased to 230 °C with rate 6 °C/menit; linearity, limit of detection, limit of quantitation, accuracy, precision, and specificity parameters met the acceptance limits. From 10 spicy cassava chips samples which were analyzed, they did not reveal any content of methyl salicylate. Methyl salicylate contained in the positive control

Evidence for non-CpG methylation in mammals

DEFF Research Database (Denmark)

Yan, Jie; Zierath, Juleen R; Barres, Romain

2011-01-01

In mammals, the existence of cytosine methylation on non-CpG sequences is controversial. Here, we adapted a LuminoMetric-based Assay (LUMA) to determine global non-CpG methylation levels in rodent and human tissues. We observed that......In mammals, the existence of cytosine methylation on non-CpG sequences is controversial. Here, we adapted a LuminoMetric-based Assay (LUMA) to determine global non-CpG methylation levels in rodent and human tissues. We observed that...

DNA methylation in states of cell physiology and pathology.

Directory of Open Access Journals (Sweden)

Lech Chyczewski

2007-10-01

Full Text Available DNA methylation is one of epigenetic mechanisms regulating gene expression. The methylation pattern is determined during embryogenesis and passed over to differentiating cells and tissues. In a normal cell, a significant degree of methylation is characteristic for extragenic DNA (cytosine within the CG dinucleotide while CpG islands located in gene promoters are unmethylated, except for inactive genes of the X chromosome and the genes subjected to genomic imprinting. The changes in the methylation pattern, which may appear as the organism age and in early stages of cancerogenesis, may lead to the silencing of over ninety endogenic genes. It has been found, that these disorders consist not only of the methylation of CpG islands, which are normally unmethylated, but also of the methylation of other dinucleotides, e.g. CpA. Such methylation has been observed in non-small cell lung cancer, in three regions of the exon 5 of the p53 gene (so-called "non-CpG" methylation. The knowledge of a normal methylation process and its aberrations appeared to be useful while searching for new markers enabling an early detection of cancer. With the application of the Real-Time PCR technique (using primers for methylated and unmethylated sequences five new genes which are potential biomarkers of lung cancer have been presented.

21 CFR 172.872 - Methyl ethyl cellulose.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Methyl ethyl cellulose. 172.872 Section 172.872... CONSUMPTION Multipurpose Additives § 172.872 Methyl ethyl cellulose. The food additive methyl ethyl cellulose... a cellulose ether having the general formula [C6H(10 -x-y)O5(CH3)x(C2H5)y]n, where x is the number...

Analysis of DNA methylation in various swine tissues.

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Chun Yang

Full Text Available DNA methylation is known to play an important role in regulating gene expression during biological development and tissue differentiation in eukaryotes. In this study, we used the fluorescence-labeled methylation-sensitive amplified polymorphism (F-MSAP method to assess the extent and pattern of cytosine methylation in muscle, heart, liver, spleen, lung, kidney and stomach from the swine strain Laiwu, and we also examined specific methylation patterns in the seven tissues. In total, 96,371 fragments, each representing a recognition site cleaved by either or both EcoRI + HpaII and EcoRI + MspI, the HpaII and MspI are isoschizomeric enzymes, were amplified using 16 pairs of selective primers. A total of 50,094 sites were found to be methylated at cytosines in seven tissues. The incidence of DNA methylation was approximately 53.99% in muscle, 51.24% in the heart, 50.18% in the liver, 53.31% in the spleen, 51.97% in the lung, 51.15% in the kidney and 53.39% in the stomach, as revealed by the incidence of differential digestion. Additionally, differences in DNA methylation levels imply that such variations may be related to specific gene expression during tissue differentiation, growth and development. Three types of bands were generated in the F-MSAP profile, the total numbers of these three types of bands in the seven tissues were 46,277, 24,801 and 25,293, respectively.In addition, different methylation patterns were observed in seven tissues from pig, and almost all of the methylation patterns detected by F-MSAP could be confirmed by Southern analysis using the isolated amplified fragments as probes. The results clearly demonstrated that the F-MSAP technique can be adapted for use in large-scale DNA methylation detection in the pig genome.

SINE transcription by RNA polymerase III is suppressed by histone methylation but not by DNA methylation

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Varshney, Dhaval; Vavrova-Anderson, Jana; Oler, Andrew J.; Cowling, Victoria H.; Cairns, Bradley R.; White, Robert J.

2015-01-01

Short interspersed nuclear elements (SINEs), such as Alu, spread by retrotransposition, which requires their transcripts to be copied into DNA and then inserted into new chromosomal sites. This can lead to genetic damage through insertional mutagenesis and chromosomal rearrangements between non-allelic SINEs at distinct loci. SINE DNA is heavily methylated and this was thought to suppress its accessibility and transcription, thereby protecting against retrotransposition. Here we provide several lines of evidence that methylated SINE DNA is occupied by RNA polymerase III, including the use of high-throughput bisulphite sequencing of ChIP DNA. We find that loss of DNA methylation has little effect on accessibility of SINEs to transcription machinery or their expression in vivo. In contrast, a histone methyltransferase inhibitor selectively promotes SINE expression and occupancy by RNA polymerase III. The data suggest that methylation of histones rather than DNA plays a dominant role in suppressing SINE transcription. PMID:25798578

Acceleration of age-associated methylation patterns in HIV-1-infected adults.

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Tammy M Rickabaugh

Full Text Available Patients with treated HIV-1-infection experience earlier occurrence of aging-associated diseases, raising speculation that HIV-1-infection, or antiretroviral treatment, may accelerate aging. We recently described an age-related co-methylation module comprised of hundreds of CpGs; however, it is unknown whether aging and HIV-1-infection exert negative health effects through similar, or disparate, mechanisms. We investigated whether HIV-1-infection would induce age-associated methylation changes. We evaluated DNA methylation levels at >450,000 CpG sites in peripheral blood mononuclear cells (PBMC of young (20-35 and older (36-56 adults in two separate groups of participants. Each age group for each data set consisted of 12 HIV-1-infected and 12 age-matched HIV-1-uninfected samples for a total of 96 samples. The effects of age and HIV-1 infection on methylation at each CpG revealed a strong correlation of 0.49, p<1 x 10(-200 and 0.47, p<1 x 10(-200. Weighted gene correlation network analysis (WGCNA identified 17 co-methylation modules; module 3 (ME3 was significantly correlated with age (cor=0.70 and HIV-1 status (cor=0.31. Older HIV-1+ individuals had a greater number of hypermethylated CpGs across ME3 (p=0.015. In a multivariate model, ME3 was significantly associated with age and HIV status (Data set 1: βage=0.007088, p=2.08 x 10(-9; βHIV=0.099574, p=0.0011; Data set 2: βage=0.008762, p=1.27 x 10(-5; βHIV=0.128649, p=0.0001. Using this model, we estimate that HIV-1 infection accelerates age-related methylation by approximately 13.7 years in data set 1 and 14.7 years in data set 2. The genes related to CpGs in ME3 are enriched for polycomb group target genes known to be involved in cell renewal and aging. The overlap between ME3 and an aging methylation module found in solid tissues is also highly significant (Fisher-exact p=5.6 x 10(-6, odds ratio=1.91. These data demonstrate that HIV-1 infection is associated with methylation patterns that

Genetic and DNA methylation changes in cotton (Gossypium genotypes and tissues.

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Kenji Osabe

Full Text Available In plants, epigenetic regulation is important in normal development and in modulating some agronomic traits. The potential contribution of DNA methylation mediated gene regulation to phenotypic diversity and development in cotton was investigated between cotton genotypes and various tissues. DNA methylation diversity, genetic diversity, and changes in methylation context were investigated using methylation-sensitive amplified polymorphism (MSAP assays including a methylation insensitive enzyme (BsiSI, and the total DNA methylation level was measured by high-performance liquid chromatography (HPLC. DNA methylation diversity was greater than the genetic diversity in the selected cotton genotypes and significantly different levels of DNA methylation were identified between tissues, including fibre. The higher DNA methylation diversity (CHG methylation being more diverse than CG methylation in cotton genotypes suggest epigenetic regulation may be important for cotton, and the change in DNA methylation between fibre and other tissues hints that some genes may be epigenetically regulated for fibre development. The novel approach using BsiSI allowed direct comparison between genetic and epigenetic diversity, and also measured CC methylation level that cannot be detected by conventional MSAP.

Genetic and DNA methylation changes in cotton (Gossypium) genotypes and tissues.

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Osabe, Kenji; Clement, Jenny D; Bedon, Frank; Pettolino, Filomena A; Ziolkowski, Lisa; Llewellyn, Danny J; Finnegan, E Jean; Wilson, Iain W

2014-01-01

In plants, epigenetic regulation is important in normal development and in modulating some agronomic traits. The potential contribution of DNA methylation mediated gene regulation to phenotypic diversity and development in cotton was investigated between cotton genotypes and various tissues. DNA methylation diversity, genetic diversity, and changes in methylation context were investigated using methylation-sensitive amplified polymorphism (MSAP) assays including a methylation insensitive enzyme (BsiSI), and the total DNA methylation level was measured by high-performance liquid chromatography (HPLC). DNA methylation diversity was greater than the genetic diversity in the selected cotton genotypes and significantly different levels of DNA methylation were identified between tissues, including fibre. The higher DNA methylation diversity (CHG methylation being more diverse than CG methylation) in cotton genotypes suggest epigenetic regulation may be important for cotton, and the change in DNA methylation between fibre and other tissues hints that some genes may be epigenetically regulated for fibre development. The novel approach using BsiSI allowed direct comparison between genetic and epigenetic diversity, and also measured CC methylation level that cannot be detected by conventional MSAP.

Methyl esters from vegetable oils with hydroxy fatty acids: Comparison of lesquerella and castor methyl esters

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The search for alternative feedstocks for biodiesel as partial replacement for petrodiesel has recently extended to castor oil. In this work, the castor oil methyl esters were prepared and their properties determined in comparison to the methyl esters of lesquerella oil, which in turn is seen as alt...

Bridging the Gap Between Protein Carboxyl Methylation and Phospholipid Methylation to Understand Glucose-Stimulated Insulin Secretion From the Pancreatic β Cell

OpenAIRE

Kowluru, Anjaneyulu

2007-01-01

Recent findings have implicated post-translational modifications at C-terminal cysteines [e.g., methylation] of specific proteins [e.g., G-proteins] in glucose-stimulated insulin secretion [GSIS]. Furthermore, methylation at the C-terminal leucine of the catalytic subunit of protein phosphatase 2A [PP2Ac] has also been shown to be relevant for GSIS. In addition to these two classes of protein methyl transferases, a novel class of glucose-activated phospholipid methyl transferases have also be...

Biological meaning of the methyl eugenol to fruit flies

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Tachi, S.; Subahar, S

1998-12-16

The objective of this research is to test a hypothesis whether methyl eugenol has a benefit in sexual selection of fruit flies and to find at what age the male flies respond to methyl eugenol. This test was conducted using carambola fruit fly (Bractocera carambolae) at Inter University Center for Life Science of ITB. The results of the tests are summarized as follows ; 1. Males started to respond to methyl eugenol at the age of 11 days old and the maximum number of males were recorded on 14 and 15 days old. 2. Most of the carambola fruit fly start to respond to methyl eugenol before they become sexually mature. 3. A very small percentage of newly emerged males (less than 1%) survive to mate with females during treatment with methyl eugenol. Methyl eugenol has benefit in sexual selection of carabola fruit fly, i.e., males responded to methyl eugenol before they engage in sexual activities, while females responded to methyl eugenol only when males started their mating activities. (author)

Ascorbic acid surface modified TiO2-thin layers as a fully integrated analysis system for visual simultaneous detection of organophosphorus pesticides

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Li, Shunxing; Liang, Wenjie; Zheng, Fengying; Lin, Xiaofeng; Cai, Jiabai

2014-11-01

TiO2 photocatalysis and colorimetric detection are coupled with thin layer chromatography (TLC) for the first time to develop a fully integrated analysis system. Titania@polystyrene hybrid microspheres were surface modified with ascorbic acid, denoted AA-TiO2@PS, and used as the stationary phase for TLC. Because the affinity between AA-TiO2@PS and organophosphorus pesticides (OPs) was different for different species of OPs (including chlopyrifos, malathion, parathion, parathion-methyl, and methamidophos), OPs could be separated simultaneously by the mobile phase in 12.0 min with different Rf values. After surface modification, the UV-vis wavelength response range of AA-TiO2@PS was expanded to 650 nm. Under visible-light irradiation, all of the OPs could be photodegraded to PO43- in 25.0 min. Based on the chromogenic reaction between PO43- and chromogenic agents (ammonium molybdate and ascorbic acid), OPs were quantified from color intensity images using a scanner in conjunction with image processing software. So, AA-TiO2@PS was respectively used as the stationary phase of TLC for efficient separation of OPs, as a photocatalyst for species transformation of phosphorus, and as a colorimetric probe for on-field simultaneous visual detection of OPs in natural water. Linear calibration curves for each OP ranged from 19.3 nmol P L-1 to 2.30 μmol P L-1. This integrated analysis system was simple, inexpensive, easy to operate, and sensitive.TiO2 photocatalysis and colorimetric detection are coupled with thin layer chromatography (TLC) for the first time to develop a fully integrated analysis system. Titania@polystyrene hybrid microspheres were surface modified with ascorbic acid, denoted AA-TiO2@PS, and used as the stationary phase for TLC. Because the affinity between AA-TiO2@PS and organophosphorus pesticides (OPs) was different for different species of OPs (including chlopyrifos, malathion, parathion, parathion-methyl, and methamidophos), OPs could be separated

Supramolecular Affinity Chromatography for Methylation-Targeted Proteomics.

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Garnett, Graham A E; Starke, Melissa J; Shaurya, Alok; Li, Janessa; Hof, Fraser

2016-04-05

Proteome-wide studies of post-translationally methylated species using mass spectrometry are complicated by high sample diversity, competition for ionization among peptides, and mass redundancies. Antibody-based enrichment has powered methylation proteomics until now, but the reliability, pan-specificity, polyclonal nature, and stability of the available pan-specific antibodies are problematic and do not provide a standard, reliable platform for investigators. We have invented an anionic supramolecular host that can form host-guest complexes selectively with methyllysine-containing peptides and used it to create a methylysine-affinity column. The column resolves peptides on the basis of methylation-a feat impossible with a comparable commercial cation-exchange column. A proteolyzed nuclear extract was separated on the methyl-affinity column prior to standard proteomics analysis. This experiment demonstrates that such chemical methyl-affinity columns are capable of enriching and improving the analysis of methyllysine residues from complex protein mixtures. We discuss the importance of this advance in the context of biomolecule-driven enrichment methods.

Acceleration of Age-Associated Methylation Patterns in HIV-1-Infected Adults

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Sehl, Mary; Sinsheimer, Janet S.; Hultin, Patricia M.; Hultin, Lance E.; Quach, Austin; Martínez-Maza, Otoniel; Horvath, Steve; Vilain, Eric; Jamieson, Beth D.

2015-01-01

Patients with treated HIV-1-infection experience earlier occurrence of aging-associated diseases, raising speculation that HIV-1-infection, or antiretroviral treatment, may accelerate aging. We recently described an age-related co-methylation module comprised of hundreds of CpGs; however, it is unknown whether aging and HIV-1-infection exert negative health effects through similar, or disparate, mechanisms. We investigated whether HIV-1-infection would induce age-associated methylation changes. We evaluated DNA methylation levels at >450,000 CpG sites in peripheral blood mononuclear cells (PBMC) of young (20-35) and older (36-56) adults in two separate groups of participants. Each age group for each data set consisted of 12 HIV-1-infected and 12 age-matched HIV-1-uninfected samples for a total of 96 samples. The effects of age and HIV-1 infection on methylation at each CpG revealed a strong correlation of 0.49, pmodules; module 3 (ME3) was significantly correlated with age (cor=0.70) and HIV-1 status (cor=0.31). Older HIV-1+ individuals had a greater number of hypermethylated CpGs across ME3 (p=0.015). In a multivariate model, ME3 was significantly associated with age and HIV status (Data set 1: βage= 0.007088, p=2.08 x 10-9; βHIV= 0.099574, p=0.0011; Data set 2: βage= 0.008762, p=1.27x 10-5; βHIV= 0.128649, p= 0.0001). Using this model, we estimate that HIV-1 infection accelerates age-related methylation by approximately 13.7 years in data set 1 and 14.7 years in data set 2. The genes related to CpGs in ME3 are enriched for polycomb group target genes known to be involved in cell renewal and aging. The overlap between ME3 and an aging methylation module found in solid tissues is also highly significant (Fisher-exact p=5.6 x 10-6, odds ratio=1.91). These data demonstrate that HIV-1 infection is associated with methylation patterns that are similar to age-associated patterns and suggest that general aging and HIV-1 related aging work through some common cellular

Theoretical spectroscopic characterization at low temperatures of S-methyl thioformate and O-methyl thioformate

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Senent, M. L., E-mail: senent@iem.cfmac.csic.es [Departamento de Química y Física Teóricas, Instituto de Estructura de la Materia, IEM-C.S.I.C., Serrano 121, Madrid 28006 (Spain); Puzzarini, C., E-mail: cristina.puzzarini@unibo.it [Dipartimento di Chimica G. Ciamician, Università di Bologna, Via F. Selmi 2, I-40126 Bologna (Italy); Hochlaf, M., E-mail: hochlaf@univ-mlv.fr [Laboratoire de Modélisation et Simulation Multi Echelle, Université Paris-Est, MSME UMR 8208 CNRS, 5 boulevard Descartes, 77454 Marne-la-Vallée (France); Domínguez-Gómez, R., E-mail: rosa.dominguez@upm.es [Departamento de Ingeniería Civil, Cátedra de Química, E.U.I.T. Obras Públicas, Universidad Politécnica de Madrid, Madrid (Spain); Carvajal, M., E-mail: miguel.carvajal@dfa.uhu.es [Departamento de Física Aplicada, Facultad de Ciencias Experimentales, Unidad Asociada IEM-CSIC-U.Huelva, Universidad de Huelva, 21071 Huelva (Spain)

2014-09-14

Highly correlated ab initio methods are employed to determine spectroscopic properties at low temperatures of two S-analogs of methyl formate: S-methyl thioformate CH{sub 3}-S-CHO (MSCHO) and O-methyl thioformate CH{sub 3}-O-CHS (MOCHS). Both species are detectable and they are expected to play an important role in Astrochemistry. Molecular properties are compared with those of the O-analog, methyl formate. Both isomers present two conformers cis and trans. cis-CH{sub 3}-S-CHO represents the most stable structure lying 4372.2 cm{sup −1} below cis-CH{sub 3}-O-CHS. The energy difference between the cis and trans forms is drastically lower for MSCHO (1134 cm{sup −1}) than for MOCHS (1963.6 cm{sup −1}). Harmonic and anharmonic fundamentals and the corresponding intensities, as well as the rotational constants for the ground vibrational and first excited torsional states and the centrifugal distortions constants, are provided. Low torsional energy levels have been obtained by solving variationally a two dimensional Hamiltonian expressed in terms of the two torsional degrees of freedom. The corresponding 2D potential energy surfaces have been computed at the CCSD(T)/aug-cc-pVTZ level of theory. The methyl torsional barriers V{sub 3}(cis) are determined to be 139.7 cm{sup −1} (CH{sub 3}-S-CHO) and 670.4 cm{sup −1} (CH{sub 3}-O-CHS). The A/E splitting of ground torsional state has been estimated to be 0.438 cm{sup −1} for CH{sub 3}-S-CHO and negligible for CH{sub 3}-O-CHS.

Bridging the gap between protein carboxyl methylation and phospholipid methylation to understand glucose-stimulated insulin secretion from the pancreatic beta cell.

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Kowluru, Anjaneyulu

2008-01-15

Recent findings have implicated post-translational modifications at C-terminal cysteines [e.g., methylation] of specific proteins [e.g., G-proteins] in glucose-stimulated insulin secretion [GSIS]. Furthermore, methylation at the C-terminal leucine of the catalytic subunit of protein phosphatase 2A [PP2Ac] has also been shown to be relevant for GSIS. In addition to these two classes of protein methyl transferases, a novel class of glucose-activated phospholipid methyl transferases have also been identified in the beta cell. These enzymes catalyze three successive methylations of phosphatidylethanolamine to yield phosphatidylcholine. The "newly formed" phosphatidylcholine is felt to induce alterations in the membrane fluidity, which might favor vesicular fusion with the plasma membrane for the exocytosis of insulin. The objectives of this commentary are to: (i) review the existing evidence on the regulation, by glucose and other insulin secretagogues, of post-translational carboxylmethylation [CML] of specific proteins in the beta cell; (ii) discuss the experimental evidence, which implicates regulation, by glucose and other insulin secretagogues, of phosphatidylethanolamine methylation in the islet beta cell; (iii) propose a model for potential cross-talk between the protein and lipid methylation pathways in the regulation of GSIS and (iv) highlight potential avenues for future research, including the development of specific pharmacological inhibitors to further decipher regulatory roles for these methylation reactions in islet beta cell function.

Acute effect of methyl bromide on sleep-wakefulness and its

Energy Technology Data Exchange (ETDEWEB)

Tanaka, S; Arito, H; Abuku, S; Imamiya, S

1986-01-01

In an attempt to clarify the acute effects of methyl bromide on the central nervous system, abnormal electrocorticographic activity and changes in sleep-wakefulness and its circadian rhythms were investigated after a single injection of methyl bromide. The effects of possible hydrolyzed products of methyl bromide, methanol and bromine ions on sleep and its rhythms were also examined. It was found that the hydrolyzed products of methyl bromide, bromine ions and methanol exerted little effect on the amounts of wakefulness (W), non-REM sleep (NREMS) and REM sleep (REMS) at the same molar dose as 45 mg methyl bromide/kg. Thus, it can be concluded that the methyl bromide-induced changes in sleep-wakefulness and its circadian rhythms are due to methyl bromide and not to the hydrolyzed products. It was also found that amounts of W, NREMS and REMS were changed dose-dependently after a single injection of methyl bromide and that methyl bromide significantly disrupted the circadian REMS rhythm. 17 references, 1 figure, 1 table.

Abiotic Formation of Methyl Halides in the Terrestrial Environment

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Keppler, F.

2011-12-01

Methyl chloride and methyl bromide are the most abundant chlorine and bromine containing organic compounds in the atmosphere. Since both compounds have relatively long tropospheric lifetimes they can effectively transport halogen atoms from the Earth's surface, where they are released, to the stratosphere and following photolytic oxidation form reactive halogen gases that lead to the chemical destruction of ozone. Methyl chloride and methyl bromide account for more than 20% of the ozone-depleting halogens delivered to the stratosphere and are predicted to grow in importance as the chlorine contribution to the stratosphere from anthropogenic CFCs decline. Today methyl chloride and methyl bromide originate mainly from natural sources with only a minor fraction considered to be of anthropogenic origin. However, until as recently as 2000 most of the methyl chloride and methyl bromide input to the atmosphere was considered to originate from the oceans, but investigations in recent years have clearly demonstrated that terrestrial sources such as biomass burning, wood-rotting fungi, coastal salt marshes, tropical vegetation and organic matter degradation must dominate the atmospheric budgets of these trace gases. However, many uncertainties still exist regarding strengths of both sources and sinks, as well as the mechanisms of formation of these naturally occurring halogenated gases. A better understanding of the atmospheric budget of both methyl chloride and methyl bromide is therefore required for reliable prediction of future ozone depletion. Biotic and abiotic methylation processes of chloride and bromide ion are considered to be the dominant pathways of formation of these methyl halides in nature. In this presentation I will focus on abiotic formation processes in the terrestrial environment and the potential parameters that control their emissions. Recent advances in our understanding of the abiotic formation pathway of methyl halides will be discussed. This will

DNA methylation dynamics in muscle development and disease

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Elvira eCarrio

2015-03-01

Full Text Available DNA methylation is an essential epigenetic modification for mammalian development and is crucial for the establishment and maintenance of cellular identity. Traditionally, DNA methylation has been considered as a permanent repressive epigenetic mark. However, the application of genome-wide approaches has allowed the analysis of DNA methylation in different genomic contexts revealing a more dynamic regulation than originally thought, since active DNA methylation and demethylation occur during cellular differentiation and tissue specification. Satellite cells are the primary stem cells in adult skeletal muscle and are responsible for postnatal muscle growth, hypertrophy, and muscle regeneration. This review outlines the published data regarding DNA methylation changes along the skeletal muscle program, in both physiological and pathological conditions, to better understand the epigenetic mechanisms that control myogenesis

Dietary methyl donors, methyl metabolizing enzymes, and epigenetic regulators: Diet-gene interactions and promoter CpG island hypermethylation in colorectal cancer

NARCIS (Netherlands)

Vogel, S. de; Wouters, K.A.D.; Gottschalk, R.W.H.; Schooten, F.J. van; Goeij, A.F.P.M. de; Bruïne, A.P. de; Goldbohm, R.A.; Brandt, P.A. van den; Engeland, M. van; Weijenberg, M.P.

2011-01-01

Dietary methyl donors might influence DNA methylation during carcinogenesis of colorectal cancer (CRC). Among 609 CRC cases and 1,663 subcohort members of the Netherlands Cohort Study on diet and cancer (n = 120,852), we estimated CRC risk according to methyl donor intake across genotypes of folate

Different DNA methylation patterns detected by the Amplified Methylation Polymorphism Polymerase Chain Reaction (AMP PCR) technique among various cell types of bulls

OpenAIRE

Phutikanit, Nawapen; Suwimonteerabutr, Junpen; Harrison, Dion; D'Occhio, Michael; Carroll, Bernie; Techakumphu, Mongkol

2010-01-01

Abstract Background The purpose of this study was to apply an arbitrarily primed methylation sensitive polymerase chain reaction (PCR) assay called Amplified Methylation Polymorphism Polymerase Chain Reaction (AMP PCR) to investigate the methylation profiles of somatic and germ cells obtained from Holstein bulls. Methods Genomic DNA was extracted from sperm, leukocytes and fibroblasts obtained from three bulls and digested with a methylation sensitive endonuclease (HpaII). The native genomic ...

Active transport, substrate specificity, and methylation of Hg(II) in anaerobic bacteria

Science.gov (United States)

Schaefer, Jeffra K.; Rocks, Sara S.; Zheng, Wang; Liang, Liyuan; Gu, Baohua; Morel, François M. M.

2011-01-01

The formation of methylmercury (MeHg), which is biomagnified in aquatic food chains and poses a risk to human health, is effected by some iron- and sulfate-reducing bacteria (FeRB and SRB) in anaerobic environments. However, very little is known regarding the mechanism of uptake of inorganic Hg by these organisms, in part because of the inherent difficulty in measuring the intracellular Hg concentration. By using the FeRB Geobacter sulfurreducens and the SRB Desulfovibrio desulfuricans ND132 as model organisms, we demonstrate that Hg(II) uptake occurs by active transport. We also establish that Hg(II) uptake by G. sulfurreducens is highly dependent on the characteristics of the thiols that bind Hg(II) in the external medium, with some thiols promoting uptake and methylation and others inhibiting both. The Hg(II) uptake system of D. desulfuricans has a higher affinity than that of G. sulfurreducens and promotes Hg methylation in the presence of stronger complexing thiols. We observed a tight coupling between Hg methylation and MeHg export from the cell, suggesting that these two processes may serve to avoid the build up and toxicity of cellular Hg. Our results bring up the question of whether cellular Hg uptake is specific for Hg(II) or accidental, occurring via some essential metal importer. Our data also point at Hg(II) complexation by thiols as an important factor controlling Hg methylation in anaerobic environments. PMID:21555571

Novel methyl transfer during chemotaxis in Bacillus subtilis

International Nuclear Information System (INIS)

Thoelke, M.S.; Kirby, J.R.; Ordal, G.W.

1989-01-01

If Bacillus subtilis is incubated in radioactive methionine in the absence of protein synthesis, the methyl-accepting chemotaxis proteins (MCPs) become radioactively methylated. If the bacteria are further incubated in excess nonradioactive methionine (cold-chased) and then given the attractant aspartate, the MCPs lose about half of their radioactivity due to turnover, in which lower specific activity methyl groups from S-adenosylmethionine (AdoMet) replace higher specific activity ones. Due to the cold-chase, the specific activity of the AdoMet pool is reduced at least 2-fold. If, later, the attractant is removed, higher specific activity methyl groups return to the MCPs. Thus, there must exist an unidentified methyl carrier than can reversibly receive methyl groups from the MCPs. In a similar experiment, labeled cells were transferred to a flow cell and exposed to addition and removal of attractant and of repellent. All four kinds of stimuli were found to cause methanol production. Bacterial with maximally labeled MCPs were exposed to many cycles of addition and removal of attractant; the maximum amount of radioactive methanol was evolved on the third, not the first, cycle. This result suggests that there is a precursor-product relationship between methyl groups on the MCPs and on the unidentified carrier, which might be the direct source of methanol. However, since no methanol was produced when a methyltransferase mutant, whose MCPs were unmethylated, was exposed to addition and removal of attractant or repellent, the methanol must ultimately derive from methylated MCPs

Dynamic instability of genomic methylation patterns in pluripotent stem cells

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Ooi Steen KT

2010-09-01

Full Text Available Abstract Background Genomic methylation patterns are established during gametogenesis, and perpetuated in somatic cells by faithful maintenance methylation. There have been previous indications that genomic methylation patterns may be less stable in embryonic stem (ES cells than in differentiated somatic cells, but it is not known whether different mechanisms of de novo and maintenance methylation operate in pluripotent stem cells compared with differentiating somatic cells. Results In this paper, we show that ablation of the DNA methyltransferase regulator DNMT3L (DNA methyltransferase 3-like in mouse ES cells renders them essentially incapable of de novo methylation of newly integrated retroviral DNA. We also show that ES cells lacking DNMT3L lose DNA methylation over time in culture, suggesting that DNA methylation in ES cells is the result of dynamic loss and gain of DNA methylation. We found that wild-type female ES cells lose DNA methylation at a much faster rate than do male ES cells; this defect could not be attributed to sex-specific differences in expression of DNMT3L or of any DNA methyltransferase. We also found that human ES and induced pluripotent stem cell lines showed marked but variable loss of methylation that could not be attributed to sex chromosome constitution or time in culture. Conclusions These data indicate that DNA methylation in pluripotent stem cells is much more dynamic and error-prone than is maintenance methylation in differentiated cells. DNA methylation requires DNMT3L in stem cells, but DNMT3L is not expressed in differentiating somatic cells. Error-prone maintenance methylation will introduce unpredictable phenotypic variation into clonal populations of pluripotent stem cells, and this variation is likely to be much more pronounced in cultured female cells. This epigenetic variability has obvious negative implications for the clinical applications of stem cells.

Quantitative DNA methylation analysis of candidate genes in cervical cancer.

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Erin M Siegel

Full Text Available Aberrant DNA methylation has been observed in cervical cancer; however, most studies have used non-quantitative approaches to measure DNA methylation. The objective of this study was to quantify methylation within a select panel of genes previously identified as targets for epigenetic silencing in cervical cancer and to identify genes with elevated methylation that can distinguish cancer from normal cervical tissues. We identified 49 women with invasive squamous cell cancer of the cervix and 22 women with normal cytology specimens. Bisulfite-modified genomic DNA was amplified and quantitative pyrosequencing completed for 10 genes (APC, CCNA, CDH1, CDH13, WIF1, TIMP3, DAPK1, RARB, FHIT, and SLIT2. A Methylation Index was calculated as the mean percent methylation across all CpG sites analyzed per gene (~4-9 CpG site per sequence. A binary cut-point was defined at >15% methylation. Sensitivity, specificity and area under ROC curve (AUC of methylation in individual genes or a panel was examined. The median methylation index was significantly higher in cases compared to controls in 8 genes, whereas there was no difference in median methylation for 2 genes. Compared to HPV and age, the combination of DNA methylation level of DAPK1, SLIT2, WIF1 and RARB with HPV and age significantly improved the AUC from 0.79 to 0.99 (95% CI: 0.97-1.00, p-value = 0.003. Pyrosequencing analysis confirmed that several genes are common targets for aberrant methylation in cervical cancer and DNA methylation level of four genes appears to increase specificity to identify cancer compared to HPV detection alone. Alterations in DNA methylation of specific genes in cervical cancers, such as DAPK1, RARB, WIF1, and SLIT2, may also occur early in cervical carcinogenesis and should be evaluated.

Global DNA methylation of ischemic stroke subtypes.

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Carolina Soriano-Tárraga

Full Text Available Ischemic stroke (IS, a heterogeneous multifactorial disorder, is among the leading causes of mortality and long-term disability in the western world. Epidemiological data provides evidence for a genetic component to the disease, but its epigenetic involvement is still largely unknown. Epigenetic mechanisms, such as DNA methylation, change over time and may be associated with aging processes and with modulation of the risk of various pathologies, such as cardiovascular disease and stroke. We analyzed 2 independent cohorts of IS patients. Global DNA methylation was measured by luminometric methylation assay (LUMA of DNA blood samples. Univariate and multivariate regression analyses were used to assess the methylation differences between the 3 most common IS subtypes, large-artery atherosclerosis (LAA, small-artery disease (SAD, and cardio-aortic embolism (CE. A total of 485 IS patients from 2 independent hospital cohorts (n = 281 and n = 204 were included, distributed across 3 IS subtypes: LAA (78/281, 59/204, SAD (97/281, 53/204, and CE (106/281, 89/204. In univariate analyses, no statistical differences in LUMA levels were observed between the 3 etiologies in either cohort. Multivariate analysis, adjusted by age, sex, hyperlipidemia, and smoking habit, confirmed the lack of differences in methylation levels between the analyzed IS subtypes in both cohorts. Despite differences in pathogenesis, our results showed no global methylation differences between LAA, SAD, and CE subtypes of IS. Further work is required to establish whether the epigenetic mechanism of methylation might play a role in this complex disease.

Influence of prenatal arsenic exposure and newborn sex on global methylation of cord blood DNA.

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J Richard Pilsner

Full Text Available BACKGROUND: An emerging body of evidence indicates that early-life arsenic (As exposure may influence the trajectory of health outcomes later in life. However, the mechanisms underlying these observations are unknown. OBJECTIVE: The objective of this study was to investigate the influence of prenatal As exposure on global methylation of cord blood DNA in a study of mother/newborn pairs in Matlab, Bangladesh. DESIGN: Maternal and cord blood DNA were available from a convenience sample of 101 mother/newborn pairs. Measures of As exposure included maternal urinary As (uAs, maternal blood As (mbAs and cord blood As (cbAs. Several measures of global DNA methylation were assessed, including the [3H]-methyl-incorporation assay and three Pyrosequencing assays: Alu, LINE-1 and LUMA. RESULTS: In the total sample, increasing quartiles of maternal uAs were associated with an increase in covariate-adjusted means of newborn global DNA methylation as measured by the [3H]-methyl-incorporation assay (quartile 1 (Q1 and Q2 vs. Q4; p = 0.06 and 0.04, respectively. Sex-specific linear regression analyses, while not reaching significance level of 0.05, indicated that the associations between As exposures and Alu, LINE-1 and LUMA were positive among male newborns (N = 58 but negative among female newborns (N = 43; tests for sex differences were borderline significant for the association of cbAs and mbAs with Alu (p = 0.05 and 0.09, respectively and for the association between maternal uAs and LINE-1 (p = 0.07. Sex-specific correlations between maternal urinary creatinine and newborn methyl-incorporation, Alu and LINE-1 were also evident (p<0.05. CONCLUSIONS: These results suggest that prenatal As exposure is associated with global DNA methylation in cord blood DNA, possibly in a sex-specific manner. Arsenic-induced epigenetic modifications in utero may potentially influence disease outcomes later in life. Additional studies are needed to confirm

Infraspecific DNA methylation polymorphism in cotton (Gossypium hirsutum L.).

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Keyte, Anna L; Percifield, Ryan; Liu, Bao; Wendel, Jonathan F

2006-01-01

Cytosine methylation is important in the epigenetic regulation of gene expression and development in plants and has been implicated in silencing duplicate genes after polyploid formation in several plant groups. Relatively little information exists, however, on levels and patterns of methylation polymorphism (MP) at homologous loci within species. Here we explored the levels and patterns of methylation-polymorphism diversity at CCGG sites within allotetraploid cotton, Gossypium hirsutum, using a methylation-sensitive amplified fragment length polymorphism screen and a selected set of 20 G. hirsutum accessions for which we have information on genetic polymorphism levels and relationships. Methylation and MP exist at high levels within G. hirsutum: of 150 HpaII/MspI sites surveyed, 48 were methylated at the inner cytosine (32%) and 32 of these were polymorphic (67%). Both these values are higher than comparable measures of genetic diversity using restriction fragment length polymorphisms. The high percentage of methylation-polymorphic sites and potential relationship to gene expression underscore the potential significance of MP within and among populations. We speculate that biased correlation of methylation-polymorphic sites and genes in cotton may be a consequence of polyploidy and the attendant doubling of all genes.

Epigenetics in Alzheimer's Disease: Perspective of DNA Methylation.

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Qazi, Talal Jamil; Quan, Zhenzhen; Mir, Asif; Qing, Hong

2018-02-01

Research over the years has shown that causes of Alzheimer's disease are not well understood, but over the past years, the involvement of epigenetic mechanisms in the developing memory formation either under pathological or physiological conditions has become clear. The term epigenetics represents the heredity of changes in phenotype that are independent of altered DNA sequences. Different studies validated that cytosine methylation of genomic DNA decreases with age in different tissues of mammals, and therefore, the role of epigenetic factors in developing neurological disorders in aging has been under focus. In this review, we summarized and reviewed the involvement of different epigenetic mechanisms especially the DNA methylation in Alzheimer's disease (AD), late-onset Alzheimer's disease (LOAD), familial Alzheimer's disease (FAD), and autosomal dominant Alzheimer's disease (ADAD). Down to the minutest of details, we tried to discuss the methylation patterns like mitochondrial DNA methylation and ribosomal DNA (rDNA) methylation. Additionally, we mentioned some therapeutic approaches related to epigenetics, which could provide a potential cure for AD. Moreover, we reviewed some recent studies that validate DNA methylation as a potential biomarker and its role in AD. We hope that this review will provide new insights into the understanding of AD pathogenesis from the epigenetic perspective especially from the perspective of DNA methylation.

HIGHLY METHYL ESTERIFIED SEEDS is a pectin methyl esterase involved in embryo development.

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Levesque-Tremblay, Gabriel; Müller, Kerstin; Mansfield, Shawn D; Haughn, George W

2015-03-01

Homogalacturonan pectin domains are synthesized in a highly methyl-esterified form that later can be differentially demethyl esterified by pectin methyl esterase (PME) to strengthen or loosen plant cell walls that contain pectin, including seed coat mucilage, a specialized secondary cell wall of seed coat epidermal cells. As a means to identify the active PMEs in seed coat mucilage, we identified seven PMEs expressed during seed coat development. One of these, HIGHLY METHYL ESTERIFIED SEEDS (HMS), is abundant during mucilage secretion, peaking at 7 d postanthesis in both the seed coat and the embryo. We have determined that this gene is required for normal levels of PME activity and homogalacturonan methyl esterification in the seed. The hms-1 mutant displays altered embryo morphology and mucilage extrusion, both of which are a consequence of defects in embryo development. A significant decrease in the size of cells in the embryo suggests that the changes in embryo morphology are a consequence of lack of cell expansion. Progeny from a cross between hms-1 and the previously characterized PME inhibitor5 overexpression line suggest that HMS acts independently from other cell wall-modifying enzymes in the embryo. We propose that HMS is required for cell wall loosening in the embryo to facilitate cell expansion during the accumulation of storage reserves and that its role in the seed coat is masked by redundancy. © 2015 American Society of Plant Biologists. All Rights Reserved.

DNA methylation levels analysis in four tissues of sea cucumber Apostichopus japonicus based on fluorescence-labeled methylation-sensitive amplified polymorphism (F-MSAP) during aestivation.

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Zhao, Ye; Chen, Muyan; Storey, Kenneth B; Sun, Lina; Yang, Hongsheng

2015-03-01

DNA methylation plays an important role in regulating transcriptional change in response to environmental stimuli. In the present study, DNA methylation levels of tissues of the sea cucumber Apostichopus japonicus were analyzed by the fluorescence-labeled methylation-sensitive amplified polymorphism (F-MSAP) technique over three stages of the aestivation cycle. Overall, a total of 26,963 fragments were amplified including 9112 methylated fragments among four sea cucumber tissues using 18 pairs of selective primers. Results indicated an average DNA methylation level of 33.79% for A. japonicus. The incidence of DNA methylation was different across tissue types in the non-aestivation stage: intestine (30.16%), respiratory tree (27.61%), muscle (27.94%) and body wall (56.25%). Our results show that hypermethylation accompanied deep-aestivation in A. japonicus, which suggests that DNA methylation may have an important role in regulating global transcriptional suppression during aestivation. Further analysis indicated that the main DNA modification sites were focused on intestine and respiratory tree tissues and that full-methylation but not hemi-methylation levels exhibited significant increases in the deep-aestivation stage. Copyright © 2014 Elsevier Inc. All rights reserved.

Regulation and function of DNA methylation in plants and animals

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He, Xinjian

2011-02-15

DNA methylation is an important epigenetic mark involved in diverse biological processes. In plants, DNA methylation can be established through the RNA-directed DNA methylation pathway, an RNA interference pathway for transcriptional gene silencing (TGS), which requires 24-nt small interfering RNAs. In mammals, de novo DNA methylation occurs primarily at two developmental stages: during early embryogenesis and during gametogenesis. While it is not clear whether establishment of DNA methylation patterns in mammals involves RNA interference in general, de novo DNA methylation and suppression of transposons in germ cells require 24-32-nt piwi-interacting small RNAs. DNA methylation status is dynamically regulated by DNA methylation and demethylation reactions. In plants, active DNA demethylation relies on the repressor of silencing 1 family of bifunctional DNA glycosylases, which remove the 5-methylcytosine base and then cleave the DNA backbone at the abasic site, initiating a base excision repair (BER) pathway. In animals, multiple mechanisms of active DNA demethylation have been proposed, including a deaminase- and DNA glycosylase-initiated BER pathway. New information concerning the effects of various histone modifications on the establishment and maintenance of DNA methylation has broadened our understanding of the regulation of DNA methylation. The function of DNA methylation in plants and animals is also discussed in this review. © 2011 IBCB, SIBS, CAS All rights reserved.

Comprehensive analysis of preeclampsia-associated DNA methylation in the placenta.

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Tianjiao Chu

Full Text Available A small number of recent reports have suggested that altered placental DNA methylation may be associated with early onset preeclampsia. It is important that further studies be undertaken to confirm and develop these findings. We therefore undertook a systematic analysis of DNA methylation patterns in placental tissue from 24 women with preeclampsia and 24 with uncomplicated pregnancy outcome.We analyzed the DNA methylation status of approximately 27,000 CpG sites in placental tissues in a massively parallel fashion using an oligonucleotide microarray. Follow up analysis of DNA methylation at specific CpG loci was performed using the Epityper MassArray approach and high-throughput bisulfite sequencing.Preeclampsia-specific DNA methylation changes were identified in placental tissue samples irrespective of gestational age of delivery. In addition, we identified a group of CpG sites within specific gene sequences that were only altered in early onset-preeclampsia (EOPET although these DNA methylation changes did not correlate with altered mRNA transcription. We found evidence that fetal gender influences DNA methylation at autosomal loci but could find no clear association between DNA methylation and gestational age.Preeclampsia is associated with altered placental DNA methylation. Fetal gender should be carefully considered during the design of future studies in which placental DNA is analyzed at the level of DNA methylation. Further large-scale analyses of preeclampsia-associated DNA methylation are necessary.

Integrating Paper Chromatography with Electrochemical Detection for the Trace Analysis of TNT in Soil

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Patrick Ryan

2015-07-01

Full Text Available We report on the development of an electrochemical probe for the trace analysis of 2,4,6-trinitrotoluene (TNT in soil samples. The probe is a combination of graphite electrodes, filter paper, with ethylene glycol and choline chloride as the solvent/electrolyte. Square wave chromatovoltammograms show the probes have a sensitivity for TNT of 0.75 nA/ng and a limit of detection of 100 ng. In addition, by taking advantage of the inherent paper chromatography step, TNT can be separated in both time and cathodic peak potential from 4-amino-dinitrotolene co-spotted on the probe or in soil samples with the presence of methyl parathion as a possible interferent.

Genome-wide DNA methylation analyses in the brain reveal four differentially methylated regions between humans and non-human primates

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Wang Jinkai

2012-08-01

Full Text Available Abstract Background The highly improved cognitive function is the most significant change in human evolutionary history. Recently, several large-scale studies reported the evolutionary roles of DNA methylation; however, the role of DNA methylation on brain evolution is largely unknown. Results To test if DNA methylation has contributed to the evolution of human brain, with the use of MeDIP-Chip and SEQUENOM MassARRAY, we conducted a genome-wide analysis to identify differentially methylated regions (DMRs in the brain between humans and rhesus macaques. We first identified a total of 150 candidate DMRs by the MeDIP-Chip method, among which 4 DMRs were confirmed by the MassARRAY analysis. All 4 DMRs are within or close to the CpG islands, and a MIR3 repeat element was identified in one DMR, but no repeat sequence was observed in the other 3 DMRs. For the 4 DMR genes, their proteins tend to be conserved and two genes have neural related functions. Bisulfite sequencing and phylogenetic comparison among human, chimpanzee, rhesus macaque and rat suggested several regions of lineage specific DNA methylation, including a human specific hypomethylated region in the promoter of K6IRS2 gene. Conclusions Our study provides a new angle of studying human brain evolution and understanding the evolutionary role of DNA methylation in the central nervous system. The results suggest that the patterns of DNA methylation in the brain are in general similar between humans and non-human primates, and only a few DMRs were identified.

Methylation pattern of IFNG in periapical granulomas and radicular cysts.

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Campos, Kelma; Gomes, Carolina Cavaliéri; de Fátima Correia-Silva, Jeane; Farias, Lucyana Conceição; Fonseca-Silva, Thiago; Bernardes, Vanessa Fátima; Pereira, Cláudia Maria; Gomez, Ricardo Santiago

2013-04-01

Interferon-γ plays an important role in the pathogenesis of periapical lesions, and the methylation of IFNG has been associated with transcriptional inactivation. The purpose of the present study was to investigate IFNG promoter methylation in association with gene transcription and protein levels in periapical granulomas and radicular cysts. Methylation-specific polymerase chain reaction was used to assess the DNA methylation pattern of the IFNG gene in 16 periapical granulomas and 13 radicular cyst samples. The transcription levels of IFNG mRNA were verified by quantitative real-time polymerase chain reaction, and protein expression was evaluated by immunohistochemistry. All the periapical lesion samples exhibited partial or total methylation of the IFNG gene. In addition, an increased methylation profile was found in radicular cysts compared with periapical granulomas. Increased IFNG mRNA expression was observed in the partially methylated periapical lesion samples relative to the samples that were completely methylated. The present study provides the first evidence of the possible impact of IFNG methylation on IFNG transcription in periapical lesions. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

78 FR 32157 - Methyl 5-(dimethylamino)-2-methyl-5-oxopentanoate; Exemption from the Requirement of a Tolerance

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2013-05-29

... study showed no treatment- related effects on mating or fertility. There were no treatment-related... a petition to EPA under the Federal Food, Drug, and Cosmetic Act (FFDCA), requesting establishment... received and the nature of the adverse effects caused by methyl 5-(dimethylamino)-2-methyl-5- oxopentanoate...

Nutrient-dependent methylation of a membrane-associated protein of Escherichia coli

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Young, C.C.; Alvarez, J.D.; Bernlohr, R.W.

1990-01-01

Starvation of a mid-log-phase culture of Escherichia coli B/r for nitrogen, phosphate, or carbon resulted in methylation of a membrane-associated protein of about 43,000 daltons (P-43) in the presence of chloramphenicol and [methyl-3H]methionine. The in vivo methylation reaction occurred with a doubling time of 2 to 5 min and was followed by a slower demethylation process. Addition of the missing nutrient to a starving culture immediately prevented further methylation of P-43. P-43 methylation is not related to the methylated chemotaxis proteins because P-43 is methylated in response to a different spectrum of nutrients and because P-43 is methylated on lysine residues. The characteristics of P-43 are similar to those of a methylated protein previously described in Bacillus subtilis and B. licheniformis and are consistent with the proposal that methylation of this protein functions in nutrient sensing

Oxidative Stress and DNA Methylation in Prostate Cancer

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Krishna Vanaja Donkena

2010-01-01

Full Text Available The protective effects of fruits, vegetables, and other foods on prostate cancer may be due to their antioxidant properties. An imbalance in the oxidative stress/antioxidant status is observed in prostate cancer patients. Genome oxidative damage in prostate cancer patients is associated with higher lipid peroxidation and lower antioxidant levels. Oxygen radicals are associated with different steps of carcinogenesis, including structural DNA damage, epigenetic changes, and protein and lipid alterations. Epigenetics affects genetic regulation, cellular differentiation, embryology, aging, cancer, and other diseases. DNA methylation is perhaps the most extensively studied epigenetic modification, which plays an important role in the regulation of gene expression and chromatin architecture, in association with histone modification and other chromatin-associated proteins. This review will provide a broad overview of the interplay of oxidative stress and DNA methylation, DNA methylation changes in regulation of gene expression, lifestyle changes for prostate cancer prevention, DNA methylation as biomarkers for prostate cancer, methods for detection of methylation, and clinical application of DNA methylation inhibitors for epigenetic therapy.

Methylation of DNA Ligase 1 by G9a/GLP Recruits UHRF1 to Replicating DNA and Regulates DNA Methylation.

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Ferry, Laure; Fournier, Alexandra; Tsusaka, Takeshi; Adelmant, Guillaume; Shimazu, Tadahiro; Matano, Shohei; Kirsh, Olivier; Amouroux, Rachel; Dohmae, Naoshi; Suzuki, Takehiro; Filion, Guillaume J; Deng, Wen; de Dieuleveult, Maud; Fritsch, Lauriane; Kudithipudi, Srikanth; Jeltsch, Albert; Leonhardt, Heinrich; Hajkova, Petra; Marto, Jarrod A; Arita, Kyohei; Shinkai, Yoichi; Defossez, Pierre-Antoine

2017-08-17

DNA methylation is an essential epigenetic mark in mammals that has to be re-established after each round of DNA replication. The protein UHRF1 is essential for this process; it has been proposed that the protein targets newly replicated DNA by cooperatively binding hemi-methylated DNA and H3K9me2/3, but this model leaves a number of questions unanswered. Here, we present evidence for a direct recruitment of UHRF1 by the replication machinery via DNA ligase 1 (LIG1). A histone H3K9-like mimic within LIG1 is methylated by G9a and GLP and, compared with H3K9me2/3, more avidly binds UHRF1. Interaction with methylated LIG1 promotes the recruitment of UHRF1 to DNA replication sites and is required for DNA methylation maintenance. These results further elucidate the function of UHRF1, identify a non-histone target of G9a and GLP, and provide an example of a histone mimic that coordinates DNA replication and DNA methylation maintenance. Copyright © 2017 Elsevier Inc. All rights reserved.

The dynamics of smoking-related disturbed methylation: a two time-point study of methylation change in smokers, non-smokers and former smokers.

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Wilson, Rory; Wahl, Simone; Pfeiffer, Liliane; Ward-Caviness, Cavin K; Kunze, Sonja; Kretschmer, Anja; Reischl, Eva; Peters, Annette; Gieger, Christian; Waldenberger, Melanie

2017-10-18

The evidence for epigenome-wide associations between smoking and DNA methylation continues to grow through cross-sectional studies. However, few large-scale investigations have explored the associations using observations for individuals at multiple time-points. Here, through the use of the Illumina 450K BeadChip and data collected at two time-points separated by approximately 7 years, we investigate changes in methylation over time associated with quitting smoking or remaining a former smoker, and those associated with continued smoking. Our results indicate that after quitting smoking the most rapid reversion of altered methylation occurs within the first two decades, with reversion rates related to the initial differences in methylation. For 52 CpG sites, the change in methylation from baseline to follow-up is significantly different for former smokers relative to the change for never smokers (lowest p-value 3.61 x 10 -39 for cg26703534, gene AHRR). Most of these sites' respective regions have been previously implicated in smoking-associated diseases. Despite the early rapid change, dynamism of methylation appears greater in former smokers vs never smokers even four decades after cessation. Furthermore, our study reveals the heterogeneous effect of continued smoking: the methylation levels of some loci further diverge between smokers and non-smokers, while others re-approach. Though intensity of smoking habit appears more significant than duration, results remain inconclusive. This study improves the understanding of the dynamic link between cigarette smoking and methylation, revealing the continued fluctuation of methylation levels decades after smoking cessation and demonstrating that continuing smoking can have an array of effects. The results can facilitate insights into the molecular mechanisms behind smoking-induced disturbed methylation, improving the possibility for development of biomarkers of past smoking behavior and increasing the understanding of