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Sample records for ovarian microsomal epoxide

  1. Ovarian expressed microsomal epoxide hydrolase: Role in detoxification of 4-vinylcyclohexene diepoxide and regulation by phosphatidylinositol-3 kinase signaling

    Bhattacharya, Poulomi, E-mail: poulomib@iastate.edu [Department of Animal Science, Iowa State University, Ames, IA 50011 (United States); Sen, Nivedita, E-mail: nsen@email.arizona.edu [Department of Physiology, University of Arizona, Tucson, AZ 85724 (United States); Hoyer, Patricia B., E-mail: Hoyer@u.arizona.edu [Department of Physiology, University of Arizona, Tucson, AZ 85724 (United States); Keating, Aileen F., E-mail: akeating@iastate.edu [Department of Animal Science, Iowa State University, Ames, IA 50011 (United States)

    2012-01-01

    4-vinylcyclohexene diepoxide (VCD) is a metabolite of 4-vinylcyclohexene (VCH) which has the potential to be formed in the ovary through CYP2E1 activity. VCD specifically destroys primordial and small primary follicles in the rodent ovary. Mouse ovaries exposed to VCD demonstrate increased mRNA and protein expression of microsomal epoxide hydrolase (mEH), and an inactive tetrol metabolite (4-(1,2-dihydroxy)ethyl-1,2-dihydroxycyclohexane) can be formed in mouse ovarian follicles, potentially through detoxification action of mEH. In contrast, mEH can bioactivate another ovotoxic chemical, 7,12-dimethylbenz[a]anthracene (DMBA) to a more toxic compound, DMBA-3,4-diol-1,2-epoxide. Thus, the present study evaluated a functional role for mEH during detoxification of VCD. Additionally, because inhibition of the phosphatidyinositol-3 kinase (PI3K) signaling pathway in a previous study protected primordial follicles from VCD-induced destruction, but accelerated DMBA-induced ovotoxicity, a role for PI3K in ovarian mEH regulation was evaluated. Using a post-natal day (PND) 4 Fischer 344 rat whole ovary culture system inhibition of mEH using cyclohexene oxide during VCD exposure resulted in a greater (P < 0.05) loss of primordial and small primary follicles relative to VCD-treated ovaries. Also, relative to controls, meh mRNA was increased (P < 0.05) on day 4 of VCD (30 μM) exposure, followed by increased (P < 0.05) mEH protein after 6 days. Furthermore, inhibition of PI3K signaling increased mEH mRNA and protein expression. Thus, these results support a functional role for mEH in the rat ovary, and demonstrate the involvement of PI3K signaling in regulation of ovarian xenobiotic metabolism by mEH. -- Highlights: ► Ovarian mEH functions to metabolize VCD to a less toxic compound. ► mEH expression is increased in a temporal pattern in response to VCD exposure. ► PI3K signaling is involved in regulation of ovarian mEH expression.

  2. The rabbit liver microsomal biotransformation of 1,1-dialkylethylenes: enantioface selection of epoxidation and enantioselectivity of epoxide hydrolysis.

    Bellucci, G; Chiappe, C; Cordoni, A; Marioni, F

    1994-01-01

    The rabbit liver microsomal biotransformation of alpha-methylstyrene (1a), 2-methyl-1-hexene (1b), 2,4,4-trimethyl-1-pentene (1c), and 1,3,3-trimethyl-1-butene (1d) has been investigated with the aim at establishing the enantioface selection of the cytochrome P-450-promoted epoxidation of the double bond and the enantioselectivity of microsomal epoxide hydrolase(mEH)-catalyzed hydrolysis of the resulting epoxides. GLC on a Chiraldex G-TA (ASTEC) column was used to determine the enantiomeric composition of the products. The epoxides 2 first produced in incubations carried out in the presence of an NADPH regenerating system were not detected, being rapidly hydrolyzed by mEH to diols 3. The enantiomeric composition of the latter showed that no enantioface selection occurred in the epoxidation of 1c and 1d, and a very low (8%) ee of the (R)-epoxide was formed from 1b. Incubation of racemic epoxides 2b-d with the microsomal fraction showed that the mEH-catalyzed hydrolysis of 2c and 2d was practically nonenantioselective, while that of 2b exhibited a selectivity E = 4.9 favoring the hydrolysis of the (S)-enantiomer. A comparison of these results with those previously obtained for linear and branched chain alkyl monosubstituted oxiranes shows that the introduction of the second alkyl substituent suppresses the selectivity of the mEH reaction of the latter and reverses that of the former substrates.

  3. Microsomal epoxide hydrolase gene polymorphisms and risk of chronic obstructive pulmonary disease: A comprehensive meta-analysis

    LI, HUI; FU, WEI-PING; HONG, ZE-HUI

    2012-01-01

    Microsomal epoxide hydrolase (EPHX1) is an enzyme involved in the detoxification the products of smoking and is proposed to be a genetic factor for the development of chronic obstructive pulmonary disease (COPD). Two functional polymorphisms of EPHX1, T113C and A139G, have been analyzed in numerous studies to assess the COPD risk attributed to these variants. However, the conclusions were controversial. We performed a comprehensive meta-analysis to clarify these findings. A total of 24 studie...

  4. Meta-analysis of microsomal epoxide hydrolase gene polymorphism and risk of hepatocellular carcinoma.

    Zhong, Jian-Hong; Xiang, Bang-De; Ma, Liang; You, Xue-Mei; Li, Le-Qun; Xie, Gui-Sheng

    2013-01-01

    Hepatocarcinogenesis is a complex process that may be influenced by many factors, including polymorphism in microsomal epoxide hydrolase (mEH). Previous work suggests an association between the Tyr113His and His139Arg mEH polymorphisms and susceptibility to hepatocellular carcinoma (HCC), but the results have been inconsistent. PubMed, EMBASE, Google Scholar and the Chinese National Knowledge Infrastructure databases were systematically searched to identify relevant studies. A meta-analysis was performed to examine the association between Tyr113His and His139Arg mEH polymorphism and susceptibility to HCC. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. Eleven studies were included in the meta-analysis, involving 1,696 HCC cases and 3,600 controls. The 113His- mEH allele was significantly associated with increased risk of HCC based on allelic contrast (OR = 1.35, 95% CI = 1.04-1.75, p = 0.02), homozygote comparison (OR = 1.65, 95% CI = 1.07-2.54, p = 0.02) and a recessive genetic model (OR = 1.54, 95% CI = 1.21-1.96, penvironment to modulate risk of HCC. Further large and well-designed studies are needed to confirm these conclusions.

  5. Meta-analysis of microsomal epoxide hydrolase gene polymorphism and risk of hepatocellular carcinoma.

    Jian-Hong Zhong

    Full Text Available BACKGROUND: Hepatocarcinogenesis is a complex process that may be influenced by many factors, including polymorphism in microsomal epoxide hydrolase (mEH. Previous work suggests an association between the Tyr113His and His139Arg mEH polymorphisms and susceptibility to hepatocellular carcinoma (HCC, but the results have been inconsistent. METHODS: PubMed, EMBASE, Google Scholar and the Chinese National Knowledge Infrastructure databases were systematically searched to identify relevant studies. A meta-analysis was performed to examine the association between Tyr113His and His139Arg mEH polymorphism and susceptibility to HCC. Odds ratios (ORs and 95% confidence intervals (95% CIs were calculated. RESULTS: Eleven studies were included in the meta-analysis, involving 1,696 HCC cases and 3,600 controls. The 113His- mEH allele was significantly associated with increased risk of HCC based on allelic contrast (OR = 1.35, 95% CI = 1.04-1.75, p = 0.02, homozygote comparison (OR = 1.65, 95% CI = 1.07-2.54, p = 0.02 and a recessive genetic model (OR = 1.54, 95% CI = 1.21-1.96, p<0.001, while individuals carrying the Arg139Arg mEH genotype had no association with increased or decreased risk of HCC. CONCLUSION: The 113His- allele polymorphism in mEH may be a risk factor for hepatocarcinogenesis, while the mEH 139Arg- allele may not be a risk or protective factor. There is substantial evidence that mEH polymorphisms interact synergistically with other genes and the environment to modulate risk of HCC. Further large and well-designed studies are needed to confirm these conclusions.

  6. Development of monoclonal antibodies to human microsomal epoxide hydrolase and analysis of “preneoplastic antigen”-like molecules

    Duan, Hongying [Department of Microbiology, Faculty of Medicine, Saitama Medical University, Moroyama-cho, Iruma-gun, Saitama 350-0495 (Japan); Yoshimura, Kazunori [Department of Physiology, Faculty of Medicine, Saitama Medical University, Moroyama-cho, Iruma-gun, Saitama 350-0495 (Japan); Kobayashi, Nobuharu; Sugiyama, Kazuo [Department of Microbiology, Faculty of Medicine, Saitama Medical University, Moroyama-cho, Iruma-gun, Saitama 350-0495 (Japan); Sawada, Jun-ichi; Saito, Yoshiro [Division of Biochemistry and Immunochemistry, National Institute of Health Sciences, Kamiyoga 1-18-1, Setagaya-ku, Tokyo 158-8501 (Japan); Morisseau, Christophe; Hammock, Bruce D. [Department of Entomology and Cancer Center, University of California, Davis, One Shields Avenue, Davis, CA 95616-8584 (United States); Akatsuka, Toshitaka, E-mail: akatsuka@saitama-med.ac.jp [Department of Microbiology, Faculty of Medicine, Saitama Medical University, Moroyama-cho, Iruma-gun, Saitama 350-0495 (Japan)

    2012-04-01

    Microsomal epoxide hydrolase (mEH) is a drug metabolizing enzyme which resides on the endoplasmic reticulum (ER) membrane and catalyzes the hydration of reactive epoxide intermediates that are formed by cytochrome P450s. mEH is also thought to have a role in bile acid transport on the plasma membrane of hepatocytes. It is speculated that efficient execution of such multiple functions is secured by its orientation and association with cytochrome P450 enzymes on the ER membrane and formation of a multiple transport system on the plasma membrane. In certain disease status, mEH loses its association with the membrane and can be detected as distinct antigens in the cytosol of preneoplastic foci of liver (preneoplastic antigen), in the serum in association with hepatitis C virus infection (AN antigen), or in some brain tumors. To analyze the antigenic structures of mEH in physiological and pathological conditions, we developed monoclonal antibodies against different portions of mEH. Five different kinds of antibodies were obtained: three, anti-N-terminal portions; one anti-C-terminal; and one, anti-conformational epitope. By combining these antibodies, we developed antigen detection methods which are specific to either the membrane-bound form or the linearized form of mEH. These methods detected mEH in the culture medium released from a hepatocellular carcinoma cell line and a glioblastoma cell line, which was found to be a multimolecular complex with a unique antigenic structure different from that of the membrane-bound form of mEH. These antibodies and antigen detection methods may be useful to study pathological changes of mEH in various human diseases. -- Highlights: ► Monoclonal antibodies against different portions of mEH were developed. ► They discriminate between the membrane-bound and the linearized forms of mEH. ► We analyze the antigenic structure of the altered form of mEH in tumor cells. ► Preneoplastic antigen is a multimolecular complex of mEH with

  7. Comparison of epoxide and free-radical mechanisms for activation of benzo[a]pyrene by Sprague-Dawley rat liver microsomes

    Selkirk, J.K.

    1980-01-01

    Coincubation of [6- 3 H]benzo[a]pyrene ([6- 3 H]BP) and [ 14 C]BP with SD rat liver microsomes produced metabolic profiles that showed that the C-6 of BP was not affected by formation of 4,5-dihydro-4,5-dihydroxy-BP, 7,8-dihydro-7,8-dihydroxy-BP, and 9,10-dihydro-9,10-dihydroxy-BP nor the 3- and 9-phenols of BP. Complete retention of tritium at C-6, except in the three quinones, confirmed the radical-cation model for formation of the 6-oxo-radical followed by oxidation to quinone. Epoxide formation at the carcinogenically active regions of BP appeared to biochemically isolate from 6-position activation and suggested that the microsomal epoxide pathway is unrelated to the radicalcation scheme. These molar ratios derived from double-label experiments reinforced the current literature that indicates the epoxide mechanism as the major pathway toward carcinogenic forms of BP

  8. Hepatitis B spliced protein (HBSP) promotes the carcinogenic effects of benzo [alpha] pyrene by interacting with microsomal epoxide hydrolase and enhancing its hydrolysis activity

    Chen, Jin-Yan; Chen, Wan-Nan; Jiao, Bo-Yan; Lin, Wan-Song; Wu, Yun-Li; Liu, Ling-Ling; Lin, Xu

    2014-01-01

    The risk of hepatocellular carcinoma (HCC) increases in chronic hepatitis B surface antigen (HBsAg) carriers who often have concomitant increase in the levels of benzo[alpha]pyrene-7,8-diol-9,10-epoxide(±) (BPDE)-DNA adduct in liver tissues, suggesting a possible co-carcinogenesis of Hepatitis B virus (HBV) and benzo[alpha]pyrene in HCC; however the exact mechanisms involved are unclear. The interaction between hepatitis B spliced protein (HBSP) and microsomal epoxide hydrolase (mEH) was confirmed using GST pull-down, co-immunoprecipitation and mammalian two-hybrid assay; the effects of HBSP on mEH-mediated B[alpha]P metabolism was examined by high performance liquid chromatography (HPLC); and the influences of HBSP on B[alpha]P carcinogenicity were evaluated by bromodeoxyuridine cell proliferation, anchorage-independent growth and tumor xenograft. HBSP could interact with mEH in vitro and in vivo, and this interaction was mediated by the N terminal 47 amino acid residues of HBSP. HBSP could greatly enhance the hydrolysis activity of mEH in cell-free mouse liver microsomes, thus accelerating the metabolism of benzo[alpha]pyrene to produce more ultimate carcinnogen, BPDE, and this effect of HBSP requires the intact HBSP molecule. Expression of HBSP significantly increased the formation of BPDE-DNA adduct in benzo[alpha]pyrene-treated Huh-7 hepatoma cells, and this enhancement was blocked by knockdown of mEH. HBSP could enhance the cell proliferation, accelerate the G1/S transition, and promote cell transformation and tumorigenesis of B[alpha]P-treated Huh-7 hepatoma cells. Our results demonstrated that HBSP could promote carcinogenic effects of B[alpha]P by interacting with mEH and enhancing its hydrolysis activity

  9. Stereo-selectivity and regio-selectivity in the metabolism of 7,8-dihydrobenzo[a]pyrene by cytochrome P450, epoxide hydrolase and hepatic microsomes from 3-methylcholanthrene-treated rats.

    Adams, J D; Yagi, H; Levin, W; Jerina, D M

    1995-03-30

    The active site of cytochrome P450 1A1 has been probed with the substrate 7,8-dihydrobenzo[a]pyrene using a purified, reconstituted system composed of cytochrome P450 1A1, NADPH-cytochrome c reductase and lipid in the presence or absence of epoxide hydrolase. The turnover of the substrate was found to be 38 nmol/nmol of cytochrome P450/min. The metabolic products that were identified are: a phenolic 7,8-dihydrobenzo[a]pyrene (20-29%); 9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (17-28%); benzo[a]pyrene (12-19%); 7-hydroxy-7,8-dihydrobenzo[a]pyrene (13-16%); 8-hydroxy-7,8-dihydrobenzo[a]pyrene (7-15%); 3-hydroxybenzo[a]pyrene (7-15%); 4,5-epoxy-4,5,7,8-tetrahydrobenzo[a]pyrene (0-4%); and a triol of 7,8,9,10-tetrahydrobenzo[a]pyrene (0-4%). 9,10-Epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene undergoes rapid hydrolysis to cis- and trans-9,10-dihydroxy-dihydroxy-7,8,9,10-tetrahydrobenzo[a]pyrene (2:1) by benzylic attack of water at C-10. Approximately 71% of the trans diols are derived from (+)-(9S,10R)-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene, indicating that cytochrome P450 1A1 has more than a 2:1 preference for selective epoxidation of an enantiotopic face of 7,8-dihydrobenzo[a]pyrene. This stereo-selectivity agrees with the postulated stereo-selectivity predicted by a previously described active site model for cytochrome P450 1A1. Epoxide hydrolase in pure form or in hepatic microsomes catalyzes the hydrolysis of 9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene, which is inhibited by 1,1,1-trichloropropane 2,3-oxide. The (+)-(9S,10R)-isomer of the epoxide is slightly preferred as a substrate over its enantiomer and is cleaved by benzylic and nonbenzylic attack. Only benzylic attack was found with (-)-(9R,10S)-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene.

  10. Comparative metabolism of methacrylonitrile and acrylonitrile to cyanide using cytochrome P4502E1 and microsomal epoxide hydrolase-null mice

    El Hadri, L.; Chanas, B.; Ghanayem, B.I.

    2005-01-01

    Methacrylonitrile (MAN) and acrylonitrile (AN) are metabolized via glutathione (GSH) conjugation or epoxide formation. We have recently shown that CYP2E1 is essential for AN epoxidation and subsequent cyanide liberation. Current studies were designed to compare the enzymatic basis of MAN vs. AN metabolism to cyanide using wild-type (WT), CYP2E1-, and mEH-null mice. Mice received a single gavage dose of 0.047, 0.095, 0.19, or 0.38 mmol/kg of MAN or AN, and blood cyanide was measured at 1 or 3 h later. Blood cyanide levels in WT mice treated with AN or MAN were dose and time dependent. At equimolar doses, significantly higher levels of cyanide were detected in the blood of MAN- vs. AN-treated mice. Further, while significant reduction in blood cyanide levels occurred in MAN-treated CYP2E1-null vs. WT mice, AN metabolism to cyanide was largely abolished in CYP2E1-null mice. Pretreatment of mice with 1-aminobenzotriazole (ABT, CYP inhibitor) demonstrated that CYPs other than CYP2E1 also contribute to MAN metabolism to cyanide. Blood cyanide levels in mEH-null mice treated with aliphatic nitriles are generally lower than levels in similarly treated WT mice. Western blot analysis showed that expression of sEH was greater in male vs. female mice. The role of various epoxide hydrolases (EHs) in the production of cyanide from aliphatic nitriles is apparently structure and dose dependent. Regardless of genotype, significantly higher levels of cyanide were measured in the blood of male vs. female mice treated with MAN or AN. In conclusion, these data showed that (1) at equimolar doses, higher blood cyanide levels were detected in mice treated with MAN vs. AN; (2) while CYP2E1 is the only enzyme responsible for AN metabolism to cyanide, other CYPs also contribute to MAN metabolism; and (3) significantly higher levels of cyanide were measured in the blood of male vs. female treated with either nitrile. Higher blood cyanide levels in male vs. female mice and in MAN- vs. AN

  11. Epoxide hydrolase affects estrogen production in the human ovary.

    Hattori, N; Fujiwara, H; Maeda, M; Fujii, S; Ueda, M

    2000-09-01

    To investigate the mechanisms of ovarian cell differentiation, we raised a new monoclonal antibody, HCL-3, which reacted with human luteal cells. It also reacted with human and porcine hepatocytes. The immunoaffinity-purified HCL-3 antigen from human corpora lutea (CL) was shown to be a 46-kDa protein. The N-terminal 22 amino acids of the 46-kDa protein from porcine liver exhibited high homology (82%) to human microsomal epoxide hydrolase (mEH). The purified HCL-3 antigen from human CL or porcine liver showed EH enzyme activity, confirming that HCL-3 antigen is identical to mEH, which is reported to detoxify the toxic substrates in the liver. In human follicles, mEH was immunohistochemically detected on granulosa and theca interna cells. In the menstrual and pregnant CL, mEH was also expressed on large and small luteal cells. A competitive inhibitor of EH, 1,2-epoxy-3,3,3-trichloropropane, inhibited the conversion of estradiol from testosterone by granulosa cells cultured in vitro, indicating the involvement of mEH in ovarian estrogen production. Because anticonvulsant sodium valproate and its analogues were reported to inhibit EH enzyme activity, these findings provide a new insight into the etiology of endocrine disorders that are frequently observed among epileptic patients taking anticonvulsant drugs.

  12. Antithyroid microsomal antibody

    Thyroid antimicrosomal antibody; Antimicrosomal antibody; Microsomal antibody; Thyroid peroxidase antibody; TPOAb ... Granulomatous thyroiditis Hashimoto thyroiditis High levels of these antibodies have also been linked with an increased risk ...

  13. The role of epoxide hydrolase Y113H gene variant in pancreatic diseases.

    Ockenga, J.; Strunck, S.; Post, C.; Schulz, H.U.; Halangk, J.; Pfutzer, R.H.; Lohr, M.; Oettle, H.; Kage, A.; Rosendahl, J.; Keim, V.; Drenth, J.P.H.; Jansen, J.B.M.J.; Lochs, H.; Witt, H.

    2009-01-01

    OBJECTIVES: Chronic pancreatitis (CP) and pancreatic adenocarcinoma (pCA) are associated with risk factors such as alcohol intake and tobacco smoking. Microsomal epoxide hydrolase (EPHX1) is a phase II detoxifying enzyme capable of tobacco-borne toxicant inactivation. We studied the role of the

  14. Epoxidation catalyst and process

    Linic, Suljo; Christopher, Phillip

    2010-10-26

    Disclosed herein is a catalytic method of converting alkenes to epoxides. This method generally includes reacting alkenes with oxygen in the presence of a specific silver catalyst under conditions suitable to produce a yield of the epoxides. The specific silver catalyst is a silver nanocrystal having a plurality of surface planes, a substantial portion of which is defined by Miller indices of (100). The reaction is performed by charging a suitable reactor with this silver catalyst and then feeding the reactants to the reactor under conditions to carry out the reaction. The reaction may be performed in batch, or as a continuous process that employs a recycle of any unreacted alkenes. The specific silver catalyst has unexpectedly high selectivity for epoxide products. Consequently, this general method (and its various embodiments) will result in extraordinarily high epoxide yields heretofore unattainable.

  15. Catalytic Epoxidation of Limonene

    E. Herrero

    2000-03-01

    Full Text Available The epoxidation of limonene with hidrogen peroxide was studied over zeolite Tibeta (a large pore material and heteropoly acids on carbono and alumina supported. PW11/C was catalyst the best tested.

  16. Mechanism of microsomal metabolism of benzene to phenol

    Hinson, J.A.; Freeman, J.P.; Potter, D.W.; Mitchum, R.K.; Evans, F.E.

    1985-05-01

    The mechanism of microsomal hydroxylation of benzene to phenol has been studied by examining the microsomal metabolism of the specifically deuterated derivative 1,3,5-(/sub 2/H/sup 3/)benzene. Evidence for the formation of the following four products was obtained: 2,3,5-(/sub 2/H/sup 3/)phenol, 3,5-(/sub 2/H/sup 2/)phenol, 2,4,6-(/sub 2/H/sup 3/)phenol, and 2,4-(/sub 2/H/sup 2/)phenol. The presence of 2,3,5-(2H3)phenol and 2,4-(/sub 2/H/sup 2/)phenol shows that, in the microsomal metabolism of benzene to phenol, a NIH shift had occurred. A deuterium isotope effect (kH/kD) of approximately 4 was detected in both the meta- and para-deuterated phenols. This finding indicates that cyclohexadienone, formed either by isomerization of the epoxide or directly from the enzyme-substrate complex, is a major intermediate in the metabolism of benzene to phenol.

  17. Generation and characterization of epoxide hydrolase 3 (EPHX3-deficient mice.

    Samantha L Hoopes

    Full Text Available Cytochrome P450 (CYP epoxygenases metabolize arachidonic acid into epoxyeicosatrienoic acids (EETs, which play an important role in blood pressure regulation, protection against ischemia-reperfusion injury, angiogenesis, and inflammation. Epoxide hydrolases metabolize EETs to their corresponding diols (dihydroxyeicosatrienoic acids; DHETs which are biologically less active. Microsomal epoxide hydrolase (EPHX1, mEH and soluble epoxide hydrolase (EPHX2, sEH were identified >30 years ago and are capable of hydrolyzing EETs to DHETs. A novel epoxide hydrolase, EPHX3, was recently identified by sequence homology and also exhibits epoxide hydrolase activity in vitro with a substrate preference for 9,10-epoxyoctadecamonoenoic acid (EpOME and 11,12-EET. EPHX3 is highly expressed in the skin, lung, stomach, esophagus, and tongue; however, its endogenous function is unknown. Therefore, we investigated the impact of genetic disruption of Ephx3 on fatty acid epoxide hydrolysis and EET-related physiology in mice. Ephx3-/- mice were generated by excising the promoter and first four exons of the Ephx3 gene using Cre-LoxP methodology. LC-MS/MS analysis of Ephx3-/- heart, lung, and skin lysates revealed no differences in endogenous epoxide:diol ratios compared to wild type (WT. Ephx3-/- mice also exhibited no change in plasma levels of fatty acid epoxides and diols relative to WT. Incubations of cytosolic and microsomal fractions prepared from Ephx3-/- and WT stomach, lung, and skin with synthetic 8,9-EET, 11,12-EET, and 9,10-EpOME revealed no significant differences in rates of fatty acid diol formation between the genotypes. Ephx3-/- hearts had similar functional recovery compared to WT hearts following ischemia/reperfusion injury. Following intranasal lipopolysaccharide (LPS exposure, Ephx3-/- mice were not different from WT in terms of lung histology, bronchoalveolar lavage fluid cell counts, or fatty acid epoxide and diol levels. We conclude that genetic

  18. Characterization of an epoxide hydrolase from the Florida red tide dinoflagellate, Karenia brevis.

    Sun, Pengfei; Leeson, Cristian; Zhi, Xiaoduo; Leng, Fenfei; Pierce, Richard H; Henry, Michael S; Rein, Kathleen S

    2016-02-01

    Epoxide hydrolases (EH, EC 3.3.2.3) have been proposed to be key enzymes in the biosynthesis of polyether (PE) ladder compounds such as the brevetoxins which are produced by the dinoflagellate Karenia brevis. These enzymes have the potential to catalyze kinetically disfavored endo-tet cyclization reactions. Data mining of K. brevis transcriptome libraries revealed two classes of epoxide hydrolases: microsomal and leukotriene A4 (LTA4) hydrolases. A microsomal EH was cloned and expressed for characterization. The enzyme is a monomeric protein with molecular weight 44kDa. Kinetic parameters were evaluated using a variety of epoxide substrates to assess substrate selectivity and enantioselectivity, as well as its potential to catalyze the critical endo-tet cyclization of epoxy alcohols. Monitoring of EH activity in high and low toxin producing cultures of K. brevis over a three week period showed consistently higher activity in the high toxin producing culture implicating the involvement of one or more EH in brevetoxin biosynthesis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Chromium Salen Mediated Alkene Epoxidation

    Petersen, Kaare Brandt; Norrby, Per-Ola; Daly, Adrian M.

    2002-01-01

    The mechanism of alkene epoxidation by chromium(v) oxo salen complexes has been studied by DFT and experimental methods. The reaction is compared to the closely related Mn-catalyzed process in an attempt to understand the dramatic difference in selectivity between the two systems. Overall......-spin surface. The low-spin addition of metal oxo species to an alkene leads to an intermediate which forms epoxide either with a barrier on the low-spin surface or without a barrier after spin inversion. Supporting evidence for this intermediate was obtained by using vinylcyclopropane traps. The chromium...

  20. Overexpression of Catalase Enhances Benzo(a)pyrene Detoxification in Endothelial Microsomes.

    Yang, Fang; Yang, Hong; Ramesh, Aramandla; Goodwin, J Shawn; Okoro, Emmanuel U; Guo, ZhongMao

    2016-01-01

    We previously reported that overexpression of catalase upregulated xenobiotic- metabolizing enzyme (XME) expression and diminished benzo(a)pyrene (BaP) intermediate accumulation in mouse aortic endothelial cells (MAECs). Endoplasmic reticulum (ER) is the most active organelle involved in BaP metabolism. To examine the involvement of ER in catalase-induced BaP detoxification, we compared the level and distribution of XMEs, and the profile of BaP intermediates in the microsomes of wild-type and catalase transgenic endothelial cells. Our data showed that endothelial microsomes were enriched in cytochrome P450 (CYP) 1A1, CYP1B1 and epoxide hydrolase 1 (EH1), and contained considerable levels of quinone oxidoreductase-1 (NQO1) and glutathione S-transferase-pi (GSTP). Treatment of wild-type MAECs with 1μM BaP for 2 h increased the expression of microsomal CYP1A1, 1B1 and NQO1 by ~300, 64 and 116%, respectively. However, the same treatment did not significantly alter the expression of EH1 and GSTP. Overexpression of catalase did not significantly increase EH1, but upregulated BaP-induced expression of microsomal CYP1A1, 1B1, NQO1 and GSTP in the following order: 1A1>NQO1>GSTP>1B1. Overexpression of catalase did not alter the distribution of each of these enzymes in the microsomes. In contrast to our previous report showing lower level of BaP phenols versus BaP diols/diones in the whole-cell, this report demonstrated that the sum of microsomal BaP phenolic metabolites were ~60% greater than that of the BaP diols/diones after exposure of microsomes to BaP. Overexpression of catalase reduced the concentrations of microsomal BaP phenols and diols/diones by ~45 and 95%, respectively. This process enhanced the ratio of BaP phenol versus diol/dione metabolites in a potent manner. Taken together, upregulation of phase II XMEs and CYP1 proteins, but not EH1 in the ER might be the mechanism by which overexpression of catalase reduces the levels of all the BaP metabolites, and

  1. Solar Synthesis of Limonene Epoxide

    Ciriminna, Rosaria; Parrino, Francesco; Pasquale, Claudio De; Palmisano, Leonardo; Pagliaro, Mario

    2017-01-01

    The silylation of crystalline titania P25, commonly used for photocatalytic degradation of pollutants, results in an exceptionally selective catalyst for the aerobic limonene epoxidation to 1,2-limonene oxide under solar light irradiation. The hypothesized mechanism involves the singlet oxygen generated through energy transfer from the excited TiO2 to adsorbed O2 molecules. The reaction product is the valued precursor of bio-based poly(limonene carbonate), a thermoplastic po...

  2. Monoclonal antibodies reveal multiple forms of expression of human microsomal epoxide hydrolase

    Duan, Hongying; Takagi, Akira [Department of Microbiology, Faculty of Medicine, Saitama Medical University, Moroyama-cho, Iruma-gun, Saitama 350-0495 (Japan); Kayano, Hidekazu [Department of Pathology, Faculty of Medicine, Saitama Medical University, Moroyama-cho, Iruma-gun, Saitama 350-0495 (Japan); Koyama, Isamu [Department of Digestive and General Surgery, Saitama International Medical Center, Faculty of Medicine, Saitama Medical University, 1397-1 Yamane, Hidaka, Saitama 350-1298 (Japan); Morisseau, Christophe; Hammock, Bruce D. [Department of Entomology and Cancer Center, University of California, Davis, One Shields Avenue, Davis, CA 95616-8584 (United States); Akatsuka, Toshitaka, E-mail: akatsuka@saitama-med.ac.jp [Department of Microbiology, Faculty of Medicine, Saitama Medical University, Moroyama-cho, Iruma-gun, Saitama 350-0495 (Japan)

    2012-04-01

    In a previous study, we developed five kinds of monoclonal antibodies against different portions of human mEH: three, anti-N-terminal; one, anti-C-terminal; one, anti-conformational epitope. Using them, we stained the intact and the permeabilized human cells of various kinds and performed flow cytometric analysis. Primary hepatocytes and peripheral blood mononuclear cells (PBMC) showed remarkable differences. On the surface, hepatocytes exhibited 4 out of 5 epitopes whereas PBMC did not show any of the epitopes. mEH was detected inside both cell types, but the most prominent expression was observed for the conformational epitope in the hepatocytes and the two N-terminal epitopes in PBMC. These differences were also observed between hepatocyte-derived cell lines and mononuclear cell-derived cell lines. In addition, among each group, there were several differences which may be related to the cultivation, the degree of differentiation, or the original cell subsets. We also noted that two glioblastoma cell lines reveal marked expression of the conformational epitope on the surface which seemed to correlate with the brain tumor-associated antigen reported elsewhere. Several cell lines also underwent selective permeabilization before flow cytometric analysis, and we noticed that the topological orientation of mEH on the ER membrane in those cells was in accordance with the previous report. However, the orientation on the cell surface was inconsistent with the report and had a great variation between the cells. These findings show the multiple mode of expression of mEH which may be possibly related to the multiple roles that mEH plays in different cells. -- Highlights: ► We examine expression of five mEH epitopes in human cells. ► Remarkable differences exist between hepatocytes and PBMC. ► mEH expression in cell lines differs depending on several factors. ► Some glioblastoma cell lines reveal marked surface expression of mEH. ► Topology of mEH on the cell surface has great variation between the cells.

  3. MICROSOMAL EPOXIDE HYDROLASE (EPHX) POLYMORPHISM AND RISK OF SPONTANEOUS ABORTION. (R825818)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  4. Epoxidation of linseed oil-Alkyd resins

    Motawie, A.M.; Ismail, E.A.; Mazroua, A.M.; Abd EI Aziem, M.S.; Ramadan, A.M.

    2004-01-01

    Three types of different linseed oil-alkyd resin ( Alk (I), Alk (II), and Alk (III) ) were prepared with the calculated amounts of mono glycerides and adipic acid (1:1, 1:2, and 2:1 Eq.Wt) respectively via monoglyceride method. The obtained alkyd resins were epoxidized via reaction with the calculated quantities of peracetic acid, which was prepared by the reaction of acetic anhydride with H 2 O 2 . Epoxidation occurred with the ratio (1: 1, 1 :3, and 1:6 Eq. Wt) of alkyd to peracetic acid. The effect of reaction time on the epoxy group content was measured during the epoxidation process. The prepared alkyd resins were analyzed by IR and H 1 NMR. The metal coated film properties of epoxidized alkyd resins were compared with those of unmodified alkyd resins. It was observed that the coating films of epoxidized alkyd resins have better in drying properties, hardness, adhesion, impact and flexibility than those of un epoxidized alkyd resins. The flammability properties of the paper coated films for the prepared brominated epoxidized alkyd resins were found to be fire retardant

  5. Diastereoselectivity in scalemic tartrate/titanium epoxidations.

    Brown, J M; Leppard, S J; Oakes, J; Thornthwaite, D

    2000-06-01

    Nonlinearity in the diastereoselectivity of epoxidation of allylic alcohols with mixtures of titanium isopropoxide, tertbutyl hydroperoxide, and diethyl tartrate was observed. Racemic and enantiomerically pure alcohols E-2-methyl-4-hexen-3-ol and E-1-methoxy-5-(O-tertbutyldimethylsilyloxy)-2-penten-4-ol were prepared. Epoxidation reactions were carried out with Ti(OPri)4 and ButOOH accompanied by diethyl tartrate of varying enantiomeric purity. The simplest explanation of these results is that a dimeric epoxidation reagent is involved, with significantly different reactivity for the homochiral and racemic forms. Copyright 2000 Wiley-Liss, Inc.

  6. Reaction of cyclic epoxide compounds with triphenylphosphine

    Kas'yan, L.I.; Stepanova, N.V.; Galafeeva, M.F.; Boldeskul, I.E.; Trachevskii, V.V.; Zefirov, N.S.

    1987-01-01

    Significant differences were found in the reactivity of a series of epoxides of cycloalkenes and methylenecycloalkanes and diepoxides in reaction with triphenylphosphine, depending both on the steric effects of the cyclic fragments and on their strain. The level of the strain can be judged indirectly from the chemical shifts of the 1 H and 13 C nuclei and the spin-spin coupling constants of the C-H bonds in the epoxide ring

  7. Cycloaliphatic epoxide resins for cationic UV - cure

    Verschueren, K.; Balwant Kaur

    1999-01-01

    This paper introduces the cyclo - aliphatic epoxide resins used for the various applications of radiation curing and their comparison with acrylate chemistry. Radiation curable coatings and inks are pre - dominantly based on acrylate chemistry but over the last few years, cationic chemistry has emerged successfully with the unique properties inherent with cyclo - aliphatic epoxide ring structures. Wide variety of cationic resins and diluents, the formulation techniques to achieve the desired properties greatly contributes to the advancement of UV - curing technology

  8. Ovarian Disorders

    ... a pregnancy can occur. Ovaries also make the female hormones estrogen and progesterone. When a woman goes through menopause, her ovaries stop making those hormones and releasing eggs. Problems with the ovaries include Ovarian cancer Ovarian ...

  9. Metabolism and binding of cyclophosphamide and its metabolite acrolein to rat hepatic microsomal cytochrome P-450

    Marinello, A.J.; Bansal, S.K.; Paul, B.; Koser, P.L.; Love, J.; Struck, R.F.; Gurtoo, H.L.

    1984-01-01

    The hepatic cytochrome P-450-mediated metabolism and metabolic activation of [chloroethyl-3H]cyclophosphamide [( chloroethyl-3H]CP) and [4-14C]cyclophosphamide [( 4-14C]CP) were investigated in vitro in the reconstituted system containing cytochrome P-450 isolated from phenobarbital-treated rats. In addition, hepatic microsomal binding and the hepatic microsome-mediated metabolism of [14C]acrolein, a metabolite of [4-14C]CP, were also investigated. The metabolism of [chloroethyl-3H]CP and [4-14C]CP to polar metabolites was found to depend on the presence of NADPH and showed concentration dependence with respect to cytochrome P-450 and NADPH:cytochrome P-450 reductase. Km and Vmax values were essentially similar. The patterns of inhibition by microsomal mixed-function oxidase inhibitors, anti-cytochrome P-450 antibody, and heat denaturation of the cytochrome P-450 were essentially similar, with subtle differences between [4-14C]CP and [chloroethyl-3H]CP metabolism. The in vitro metabolic activation of CP in the reconstituted system demonstrated predominant binding of [chloroethyl-3H]CP to nucleic acids and almost exclusive binding of [4-14C]CP to proteins. Gel electrophoresis-fluorography of the proteins in the reconstituted system treated with [4-14C]CP demonstrated localization of the 14C label in the cytochrome P-450 region. To examine this association further, hepatic microsomes were modified with [14C]acrolein in the presence and the absence of NADPH. The results confirmed covalent association between [14C]acrolein and cytochrome P-450 in the microsomes and also demonstrated further metabolism of [14C]acrolein, apparently to an epoxide, which is capable of binding covalently to proteins. The results of these investigations not only confirm the significance of primary metabolism but also emphasize the potential role of the secondary metabolism of cyclophosphamide in some of its toxic manifestations

  10. Deep Eutectic Solvents Enable More Robust Chemoenzymatic Epoxidation Reactions

    Zhou, Pengfei; Wang, Xuping; Zeng, Chaoxi; Wang, Weifei; Yang, Bo; Hollmann, F.; Wang, Yonghua

    2017-01-01

    A chemoenzymatic method for the production of epoxidized vegetable oils was developed. The unique combination of the commercial lipase G from Penicillieum camembertii with certain deep eutectic solvents enabled the efficient production of epoxidized vegetable oils.

  11. Enantioselectivity of a recombinant epoxide hydrolase from Agrobacterium radiobacter

    Lutje Spelberg, Jeffrey H.; Rink, Rick; Kellogg, Richard M.; Janssen, Dick B.

    1998-01-01

    The recombinant epoxide hydrolase from Agrobacterium radiobacter AD1 was used to obtain enantiomerically pure epoxides by means of a kinetic resolution. Epoxides such as styrene oxide and various derivatives thereof and phenyl glycidyl ether were obtained in high enantiomeric excess and in

  12. 21 CFR 172.723 - Epoxidized soybean oil.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Epoxidized soybean oil. 172.723 Section 172.723... CONSUMPTION Other Specific Usage Additives § 172.723 Epoxidized soybean oil. Epoxidized soybean oil may be... reacting soybean oil in toluene with hydrogen peroxide and formic acid. (b) It meets the following...

  13. Microsomal metabolism of trenbolone acetate metabolites ...

    Trenbolone acetate (TBA) is a synthetic growth promoter widely used in animal agriculture, and its metabolites are suspected endocrine disrupting compounds in agriculturally impacted receiving waters. However, beyond the three widely recognized TBA metabolites (17-trenbolone, 17-trenbolone and trendione), little is known about other metabolites formed in vivo and subsequently discharged into the environment, with some evidence suggesting these unknown metabolites comprise a majority of the TBA mass dosed to the animal. Here, we explored the metabolism of the three known TBA metabolites using rat liver microsome studies. All TBA metabolites are transformed into a complex mixture of monohydroxylated products. Based on product characterization, the majority are more polar than the parent metabolites but maintain their characteristic trienone backbone. A minor degree of interconversion between known metabolites was also observed, as were higher order hydroxylated products with a greater extent of reaction. Notably, the distribution and yield of products were generally comparable across a series of variably induced rat liver microsomes, as well as during additional studies with human and bovine liver microsomes. Bioassays conducted with mixtures of these transformation products suggest that androgen receptor (AR) binding activity is diminished as a result of the microsomal treatment, suggesting that the transformation products are generally less potent than

  14. Abetalipoproteinemia: A novel mutation of microsomal triglyceride ...

    Hager Barakizou

    2016-01-25

    Jan 25, 2016 ... Abetalipoproteinemia: A novel mutation of microsomal triglyceride transfer protein (MTP) gene in a young Tunisian patient. Hager Barakizou a,. *, Souha Gannouni a. , Khalil Messaoui a. , Mathilde Difilippo b. ,. Agne`s Sassolas b. , Fethi Bayoudh a a Department of Pediatrics, Military Hospital of Tunis, ...

  15. Zeaxanthin epoxidation - an in vitro approach.

    Kuczyńska, Paulina; Latowski, Dariusz; Niczyporuk, Sylvia; Olchawa-Pajor, Monika; Jahns, Peter; Gruszecki, Wiesław I; Strzałka, Kazimierz

    2012-01-01

    Zeaxanthin epoxidase (ZE) is an enzyme operating in the violaxanthin cycle, which is involved in photoprotective mechanisms. In this work model systems to study zeaxanthin (Zx) epoxidation were developed. Two assay systems are presented in which epoxidation of Zx was observed. In these assays two mutants of Arabidopsis thaliana which have active only one of the two xanthophyll cycle enzymes were used. The npq1 mutant possesses an active ZE and is thus able to convert Zx to violaxanthin (Vx) but the violaxanthin de-epoxidase (VDE) is inactive, so that Vx cannot be converted to Zx. The other mutant, npq2, possesses an active VDE and can convert exogenous Vx to Zx under strong light conditions but reverse reaction is not possible. The first assay containing thylakoids from npq1 and npq2 mutants of A. thaliana gave positive results and high efficiency of epoxidation reaction was observed. The amount of Zx was reduced by 25%. To optimize high efficiency of epoxidation reaction additional factors facilitating both fusion of the two types of thylakoids and incorporation of Zx to their membranes were also studied. The second kind of assay contained npq1 mutant thylakoids of A. thaliana supplemented with exogenous Zx and monogalactosyldiacylglycerol (MGDG). Experiments with different proportions of Zx and MGDG showed that their optimal ratio is 1:60. In such system, due to epoxidation, the amount of Zx was reduced by 38% of its initial level. The in vitro systems of Zx epoxidation described in this paper enable analysis some properties of the ZE without necessity of its isolation.

  16. Structure-Based Optimization of Arylamides as Inhibitors of Soluble Epoxide Hydrolase

    Eldrup, Anne B.; Soleymanzadeh, Fariba; Taylor, Steven J.; Muegge, Ingo; Farrow, Neil A.; Joseph, David; McKellop, Keith; Man, Chuk C.; Kukulka, Alison; De Lombaert, Stephane; (Boehringer)

    2009-11-04

    Inhibition of soluble epoxide hydrolase (sEH) is hypothesized to lead to an increase in circulating levels of epoxyeicosatrienoic acids, resulting in the potentiation of their in vivo pharmacological properties. As part of an effort to identify inhibitors of sEH with high and sustained plasma exposure, we recently performed a high throughput screen of our compound collection. The screen identified N-(3,3-diphenyl-propyl)-nicotinamide as a potent inhibitor of sEH. Further profiling of this lead revealed short metabolic half-lives in microsomes and rapid clearance in the rat. Consistent with these observations, the determination of the in vitro metabolic profile of N-(3,3-diphenyl-propyl)-nicotinamide in rat liver microsomes revealed extensive oxidative metabolism and a propensity for metabolite switching. Lead optimization, guided by the analysis of the solid-state costructure of N-(3,3-diphenyl-propyl)-nicotinamide bound to human sEH, led to the identification of a class of potent and selective inhibitors. An inhibitor from this class displayed an attractive in vitro metabolic profile and high and sustained plasma exposure in the rat after oral administration.

  17. Polymerization of epoxidized triglycerides with fluorosulfonic acid

    The use of triglycerides as agri-based renewable raw materials for the development of new products is highly desirable in view of uncertain future petroleum prices. A new method of polymerizing epoxidized soybean oil has been devised with the use of fluorosulfonic acid. Depending on the reaction con...

  18. Determination of the kinetics of ethene epoxidation

    Schouten, E.P.S.; Schouten, E.P.S.; Borman, P.C.; Borman, P.C.; Westerterp, K.R.

    1996-01-01

    Several problems and pitfalls in the use of laboratory reactors for the determination of the kinetics of ethene epoxidation over industrial silver on α-alumina catalyst are discussed. Also, commonly used methodologies for kinetic studies are dealt with because of the general nature of some problems.

  19. Efficient epoxidation of propene using molecular catalysts

    Markovits, Iulius I. E.; Anthofer, Michael H.; Kolding, Helene

    2014-01-01

    The epoxidation of propene is performed in homogeneous phase using various molecular catalysts and H2O2 or tert-butyl hydroperoxide as oxidants. A comparison between some molybdenum catalysts and methyltrioxorhenium (MTO) shows that the well known Re catalyst is the best among the examined...

  20. Titanium impregnated borosilicate zeolites for epoxidation catalysis

    Přech, Jan; Vitvarová, Dana; Lupínková, Lenka; Kubů, Martin; Čejka, Jiří

    2015-01-01

    Roč. 212, AUG 2015 (2015), s. 28-34 ISSN 1387-1811 R&D Projects: GA ČR GAP106/11/0819 Institutional support: RVO:61388955 Keywords : borosilicate * titanium impregnation * epoxidation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.349, year: 2015

  1. Teaching Green Chemistry with Epoxidized Soybean Oil

    Barcena, Homar; Tuachi, Abraham; Zhang, Yuanzhuo

    2017-01-01

    The synthesis of epoxidized soybean oil (ESO) provides students a vantage point on the application of green chemistry principles in a series of experiments. Qualitative tests review the reactions of alkenes, whereas spectroscopic analyses provide insight in monitoring functional group transformations.

  2. Metabolism of polyunsaturated (n-3) fatty acids by monkey seminal vesicles: isolation and biosynthesis of omega-3 epoxides.

    Oliw, E H; Sprecher, H W

    1991-11-27

    Monooxygenases of monkey seminal vesicles can metabolize arachidonic acid (20:4(n-6)) by w3-hydroxylation to 18(R)-hydroxyeicosatetraenoic acid (18(R)-HETE) and eicosapentaenoic acid (20:5(n-3)) to 17,18-dihydroxyeicosatetraenoic acid (Oliw, E.H. (1989) J. Biol. Chem. 264, 17845-17853). The present study aimed to further characterize the oxygenation of (n-3) polyunsaturated fatty acids. 14C-Labelled 22:6(n-3), 20:5(n-3), 20:4-(n-3) and 18:3(n-3) were incubated with microsomes of seminal vesicles of the cynomolgus monkey, NADPH and a cyclooxygenase inhibitor, diclofenac, and the main metabolites were identified by capillary gas chromatography-mass spectrometry. 22:6(n-3) was slowly metabolized to 19,20-dihydroxy-4,7,10,13,16-docosapentaenoic acid, while 20:5(n-3), 20:4(n-3) and 18:3(n-3) were metabolized more efficiently to the corresponding w4,w3-diols. The w3 epoxides, which were obtained from 20:5(n-3) and 18:3(n-3), were isolated in the presence of an epoxide hydrolase inhibitor, 1(2)epoxy-3,3,3-trichloropropane, and the geometry of the epoxides was determined to be 17S, 18R and 15S, 16R, respectively. While 20:5(n-3) was metabolized almost exclusively to the epoxide and diol pair of metabolites, 18:3(n-3) was metabolized not only to the w3 epoxide and the corresponding diol, but also to the w2 alcohol, 17(R)-hydroxy-9,12,15-octadecatrienoic acid. 22:6(n-3) and 5,8,11,14-eicosatetraynoic acid inhibited the biosynthesis of 18(R)-HETE from arachidonic acid (IC50 0.16 and 0.14 mM, respectively). In comparison with 20:4 or 18:3(n-3), 18:1(n-9) and 22:5(n-6) appeared to be slowly metabolized by seminal monooxygenases, while 18:2(n-6) was converted to the w3 alcohol and to smaller amounts of the w2 alcohol (4:1). Together, the results indicate that the w3-hydroxylase and w3-epoxygenase enzyme(s) metabolize 20:4(n-6) and 20:5(n-3) almost exclusively to the w3(R) alcohol and the w3(R, S) epoxide, respectively, while longer and shorter fatty acids either are poor

  3. Sequential enzymatic epoxidation involved in polyether lasalocid biosynthesis.

    Minami, Atsushi; Shimaya, Mayu; Suzuki, Gaku; Migita, Akira; Shinde, Sandip S; Sato, Kyohei; Watanabe, Kenji; Tamura, Tomohiro; Oguri, Hiroki; Oikawa, Hideaki

    2012-05-02

    Enantioselective epoxidation followed by regioselective epoxide opening reaction are the key processes in construction of the polyether skeleton. Recent genetic analysis of ionophore polyether biosynthetic gene clusters suggested that flavin-containing monooxygenases (FMOs) could be involved in the oxidation steps. In vivo and in vitro analyses of Lsd18, an FMO involved in the biosynthesis of polyether lasalocid, using simple olefin or truncated diene of a putative substrate as substrate mimics demonstrated that enantioselective epoxidation affords natural type mono- or bis-epoxide in a stepwise manner. These findings allow us to figure out enzymatic polyether construction in lasalocid biosynthesis. © 2012 American Chemical Society

  4. Ovarian lymphoma

    Bonet Fonseca, Ivan; Diaz Anaya, Amnia; Francis, Tabu

    2012-01-01

    50 % of pediatric oncologic pathology corresponds to mass or solid tumors, reaching about 20 % of total abdomen. The tumors that most frequently occur in the abdomen are nephroblastoma or Wilms tumor, Burkitts lymphoma, neuroblastoma, and ovarian germ cell tumors

  5. Ovarian cancer

    ... injected directly into the abdominal cavity (intraperitoneal, or IP). Radiation therapy is rarely used to treat ovarian ... About MedlinePlus Site Map FAQs Customer Support Get email updates Subscribe to RSS Follow us Disclaimers Copyright ...

  6. Ovarian Cancer

    ... I find more information about ovarian and other gynecologic cancers? Centers for Disease Control and Prevention: 800-CDC-INFO or www. cdc. gov/ cancer/ gynecologic National Cancer Institute: 800-4-CANCER or www. ...

  7. Prediction of metabolites of epoxidation reaction in MetaTox.

    Rudik, A V; Dmitriev, A V; Bezhentsev, V M; Lagunin, A A; Filimonov, D A; Poroikov, V V

    2017-10-01

    Biotransformation is a process of the chemical modifications which may lead to the reactive metabolites, in particular the epoxides. Epoxide reactive metabolites may cause the toxic effects. The prediction of such metabolites is important for drug development and ecotoxicology studies. Epoxides are formed by some oxidation reactions, usually catalysed by cytochromes P450, and represent a large class of three-membered cyclic ethers. Identification of molecules, which may be epoxidized, and indication of the specific location of epoxide functional group (which is called SOE - site of epoxidation) are important for prediction of epoxide metabolites. Datasets from 355 molecules and 615 reactions were created for training and validation. The prediction of SOE is based on a combination of LMNA (Labelled Multilevel Neighbourhood of Atom) descriptors and Bayesian-like algorithm implemented in PASS software and MetaTox web-service. The average invariant accuracy of prediction (AUC) calculated in leave-one-out and 20-fold cross-validation procedures is 0.9. Prediction of epoxide formation based on the created SAR model is included as the component of MetaTox web-service ( http://www.way2drug.com/mg ).

  8. Recent trends in ring opening of epoxides with sulfur nucleophiles.

    Ahmad, Sajjad; Zahoor, Ameer Fawad; Naqvi, Syed Ali Raza; Akash, Muhammad

    2018-02-01

    Thiolysis of epoxides offers an efficient and simple synthetic approach to access [Formula: see text]-hydroxy sulfides which are valuable scaffold in the synthesis of various important molecules in medicinal chemistry. This review article presents a recent compilation of the synthetic approaches developed after 2000 for the thiolysis of epoxides.

  9. Ring opening of epoxides with C-nucleophiles.

    Faiz, Sadia; Zahoor, Ameer Fawad

    2016-11-01

    Ring opening of epoxides has been an area of interest for organic chemists, owing to their reactivity toward nucleophiles. Such reactions yield important products depending on the type of nucleophiles used. This review article covers the synthetic approaches (1991-2015) used for the ring opening of epoxides via carbon nucleophiles.

  10. Mechanism of titanocene-mediated epoxide opening through homolytic substitution

    Gansäuer, Andreas; Barchuk, Andriy; Keller, Florian

    2007-01-01

    −titanocene complexes, the transition states of epoxide opening, and the β-titanoxy radicals formed. The results obtained provide a structural basis for the understanding of the factors determining the regioselectivity of ring opening and match the experimentally determined values. By employing substituted titanocenes...... of monomeric and dimeric Ti(III) species was found to be strongly affected by the exact steric conditions. The overall rate constants of the reductive epoxide opening were determined for the first time. These data were employed as the basis for computational studies of the structure and energies of the epoxide...... even more selective epoxide openings could be realized. Moreover, by properly adjusting the steric demands of the catalysts and the substrates the first examples of reversible epoxide openings were designed....

  11. Induction of hepatic aryl hydrocarbon hydroxylase and epoxide hydrase in Wistar rats pretreated with oral methadone hydrochloride.

    Bellward, G D; Gontovnick, L S; Otten, M

    1977-01-01

    Methadone-HCl added to the drinking water of adult female Wistar rats for 4 weeks produced an increase in the aryl hydrocarbon hydroxylase activity of the hepatic microsomal fraction to 222% of control levels. No change was seen in epoxide hydrase activity. In contrast, when male rats were treated similarly, there was an increase in epoxide hydrase activity to 212% of controls with no change in aryl hydrocarbon hydroxylase activity. No such changes were observed when the subcutaneous route of administration or chronic, low-dose, intraperitoneal injections were used. There were no differences in hepatic cytochrome P-450 or protein concentrations in treated animals as compared to their respective control groups. Control studies were carried out with quinine sulfate in the drinking water to decrease water intake to the level of the methadone-treated group. No elevation in either enzyme activity occurred in this control group. Similarly, paired-feeding studies showed the elevation of enzyme activity to be due to the methadone, not food deprivation. The effects of concurrent therapy of methadone with phenobarbital sodium or 3-methylcholanthrene were compared.

  12. Construction and characterisation of a genetically engineered Escherichia coli strain for the epoxide hydrolase-catalysed kinetic resolution of epoxides

    Visser, H.; Oliveira Vil Filho, de M.; Liese, A.; Weijers, C.A.G.M.; Verdoes, J.C.

    2003-01-01

    The Rhodotorula glutinis epoxide hydrolase, Eph1, was produced in the heterologous host Escherichia coli BL21(DE3) in order to develop a highly effective epoxide hydrolysis system. A 138-fold increase in Eph1 activity was found in cell extracts of the recombinant E. coli when compared to cell

  13. Omeprazole increases the efficacy of a soluble epoxide hydrolase inhibitor in a PGE2 induced pain model

    Goswami, Sumanta Kumar; Inceoglu, Bora; Yang, Jun; Wan, Debin; Kodani, Sean D.; Trindade da Silva, Carlos Antonio; Morisseau, Christophe; Hammock, Bruce D.

    2015-01-01

    Epoxyeicosatrienoic acids (EETs) are potent endogenous analgesic metabolites produced from arachidonic acid by cytochrome P450s (P450s). Metabolism of EETs by soluble epoxide hydrolase (sEH) reduces their activity, while their stabilization by sEH inhibition decreases both inflammatory and neuropathic pain. Here, we tested the complementary hypothesis that increasing the level of EETs through induction of P450s by omeprazole (OME), can influence pain related signaling by itself, and potentiate the anti-hyperalgesic effect of sEH inhibitor. Rats were treated with OME (100 mg/kg/day, p.o., 7 days), sEH inhibitor TPPU (3 mg/kg/day, p.o.) and OME (100 mg/kg/day, p.o., 7 days) + TPPU (3 mg/kg/day, p.o., last 3 days of OME dose) dissolved in vehicle PEG400, and their effect on hyperalgesia (increased sensitivity to pain) induced by PGE 2 was monitored. While OME treatment by itself exhibited variable effects on PGE 2 induced hyperalgesia, it strongly potentiated the effect of TPPU in the same assay. The significant decrease in pain with OME + TPPU treatment correlated with the increased levels of EETs in plasma and increased activities of P450 1A1 and P450 1A2 in liver microsomes. The results show that reducing catabolism of EETs with a sEH inhibitor yielded a stronger analgesic effect than increasing generation of EETs by OME, and combination of both yielded the strongest pain reducing effect under the condition of this study. - Highlights: • The soluble epoxide hydrolase (sEH) inhibitor TPPU is anti-hyperalgesic. • Omeprazole potentiates the anti-hyperalgesic actions of TPPU. • This potentiation is associated with increased P450 activity. • The potentiation is associated with an increase in fatty acid epoxide/diol ratio. • Joint use of sEH inhibitors and P450 inducers could result in drug–drug interactions.

  14. Microdroplets Accelerate Ring Opening of Epoxides

    Lai, Yin-Hung; Sathyamoorthi, Shyam; Bain, Ryan M.; Zare, Richard N.

    2018-03-01

    The nucleophilic opening of an epoxide is a classic organic reaction that has widespread utility in both academic and industrial applications. We have studied the reaction of limonene oxide with morpholine to form 1-methyl-2-morpholino-4-(prop-1-en-2-yl) cyclohexan-1-ol in bulk solution and in electrosprayed microdroplets with a 1:1 v/v water/methanol solvent system. We find that even after 90 min at room temperature, there is no product detected by nuclear magnetic resonance spectroscopy in bulk solution whereas in room-temperature microdroplets (2-3 μm in diameter), the yield is already 0.5% in a flight time of 1 ms as observed by mass spectrometry. This constitutes a rate acceleration of 105 in the microdroplet environment, if we assume that as much as 5% of product is formed in bulk after 90 min of reaction time. We examine how the reaction rate depends on droplet size, solvent composition, sheath gas pressure, and applied voltage. These factors profoundly influence the extent of reaction. This dramatic acceleration is not limited to just one system. We have also found that the nucleophilic opening of cis-stilbene oxide by morpholine is similarly accelerated. Such large acceleration factors in reaction rates suggest the use of microdroplets for ring opening of epoxides in other systems, which may have practical significance if such a procedure could be scaled. [Figure not available: see fulltext.

  15. Microdroplets Accelerate Ring Opening of Epoxides

    Lai, Yin-Hung; Sathyamoorthi, Shyam; Bain, Ryan M.; Zare, Richard N.

    2018-05-01

    The nucleophilic opening of an epoxide is a classic organic reaction that has widespread utility in both academic and industrial applications. We have studied the reaction of limonene oxide with morpholine to form 1-methyl-2-morpholino-4-(prop-1-en-2-yl) cyclohexan-1-ol in bulk solution and in electrosprayed microdroplets with a 1:1 v/ v water/methanol solvent system. We find that even after 90 min at room temperature, there is no product detected by nuclear magnetic resonance spectroscopy in bulk solution whereas in room-temperature microdroplets (2-3 μm in diameter), the yield is already 0.5% in a flight time of 1 ms as observed by mass spectrometry. This constitutes a rate acceleration of 105 in the microdroplet environment, if we assume that as much as 5% of product is formed in bulk after 90 min of reaction time. We examine how the reaction rate depends on droplet size, solvent composition, sheath gas pressure, and applied voltage. These factors profoundly influence the extent of reaction. This dramatic acceleration is not limited to just one system. We have also found that the nucleophilic opening of cis-stilbene oxide by morpholine is similarly accelerated. Such large acceleration factors in reaction rates suggest the use of microdroplets for ring opening of epoxides in other systems, which may have practical significance if such a procedure could be scaled. [Figure not available: see fulltext.

  16. Epoxidation of the methamphetamine pyrolysis product, trans-phenylpropene, to trans-phenylpropylene oxide by CYP enzymes and stereoselective glutathione adduct formation

    Sanga, Madhu; Younis, Islam R.; Tirumalai, Padma S.; Bland, Tina M.; Banaszewska, Monica; Konat, Gregory W.; Tracy, Timothy S.; Gannett, Peter M.; Callery, Patrick S.

    2006-01-01

    Pyrolytic products of smoked methamphetamine hydrochloride are well established. Among the various degradation products formed, trans-phenylpropene (trans-β-methylstyrene) is structurally similar to styrene analogues known to be bioactivated by CYP enzymes. In human liver microsomes, trans-phenylpropene was converted to the epoxide trans-phenylpropylene oxide (trans-2-methyl-3-phenyloxirane) and cinnamyl alcohol. Incubation of trans-phenylpropene with microsomes in the presence of enzyme-specific P450 enzyme inhibitors indicated the involvement of CYP2E1, CYP1A2, and CYP3A4 enzymes. Both (R,R)-phenylpropylene oxide and (S,S)-phenylpropylene oxide were formed in human liver microsomal preparations. Enantiomers of trans-phenylpropylene oxide were stereoselectively and regioselectively conjugated in a Phase II drug metabolism reaction catalyzed by human liver cytosolic enzymes consisting of conjugation with glutathione. The structure of the phenylpropylene oxide-glutathione adduct is consistent with nucleophilic ring-opening by attack at the benzylic carbon. Exposure of cultured C6 glial cells to (S,S)-phenylpropylene oxide produced a cytotoxic response in a concentration-dependent manner based on cell degeneration and death

  17. Microsomal lipid peroxidation as a mechanism of cellular damage. [Dissertation

    Kornbrust, D.J.

    1979-01-01

    The NADPH/iron-dependent peroxidation of lipids in rat liver microsomes was found to be dependent on the presence of free ferrous ion and maintains iron in the reduced Fe/sup 2 +/ state. Chelation of iron by EDTA inhibited peroxidation. Addition of iron, after preincubation of microsomes in the absence of iron, did not enhance the rate of peroxidation suggesting that iron acts by initiating peroxidative decomposition of membrane lipids rather than by catalyzing the breakdown of pre-formed hydroperoxides. Liposomes also underwent peroxidation in the presence of ferrous iron at a rate comparable to intact microsomes and was stimulated by ascorbate. Carbon tetrachloride initiated lipid peroxidation in the absence of free metal ions. Rates of in vitro lipid peroxidation of microsomes and homogenates were found to vary widely between different tissues and species. The effects of paraquat on lipid peroxidation was also studied. (DC)

  18. Swelling behaviour in n-pentane and mechanical properties of epoxidized natural rubber with different epoxide content

    Kinasih, N. A.; Fathurrohman, M. I.; Winarto, D. A.

    2017-07-01

    Epoxidized natural rubber (ENR) with different level of epoxidation (i.e. 10, 20, 30, 40 and 50 mol% indicated as ENR ENR10, ENR20, ENR30, ENR40 and ENR50, respectively) were prepared. They were then vulcanized by using efficient system vulcanization. The effect of epoxide content on curing characteristic, swelling and mechanical properties in N-pentane was investigated. The Attenuated Resonance Fourier Transform Infrared (ATR-FTIR) and H-Nuclear Magnetic Resonance (H-NMR) were used to determine the epoxidation level. Glass transition (Tg) of ENR samples was determined by using Direct Scanning Calorimetry (DSC). The result revealed that the resistance of ENR in N-pentane increased with increasing epoxidation level, which indicated by decreasing equilibrium mol uptake and diffusion coefficient. The compression set of ENR and aging resistance increased with increasing epoxide content, except ENR50 was due to ENR 50 have two Tg value. However, the value of hardness and tensile strength were not effected by epoxidation level.

  19. Metabolic activation of 2-methylfuran by rat microsomal systems

    Ravindranath, V.; Boyd, M.R.

    1985-01-01

    2-Methylfuran (2-MF), a constituent of cigarette smoke and coffee, causes necrosis of liver, lungs, and kidneys in rodents. 2-MF is metabolically activated by mixed-function oxidases to acetylacrolein, a reactive metabolite that binds covalently to microsomal protein. The hepatic microsomal metabolism of 2-MF to reactive metabolite required the presence of NADPH and oxygen and was dependent on incubation time and substrate concentration. The microsomal metabolism of 2-MF was inducible by pretreatment of rats with phenobarbital and was inhibited by piperonyl butoxide and N-octyl imidazole, which indicates that the metabolism of 2-MF may be mediated by cytochrome P-450. Acetylacrolein was a potent inhibitor of mixed-function oxidase and completely inhibited the microsomal metabolism of 2-MF, indicating that 2-MF is a suicide substrate for the enzyme. The sulfhydryl nucleophile cysteine was a better trapping agent of the reactive metabolite of 2-MF than N-acetylcysteine or glutathione. Lysine decreased the covalent binding of 2-MF metabolites, presumably by reacting with the aldehyde group of acetylacrolein. In addition, in the presence of NADPH, 2-MF was bioactivated by both pulmonary and renal cortical microsomes to reactive metabolites that were covalently bound to microsomal proteins

  20. Enantioselective Epoxide Polymerization Using a Bimetallic Cobalt Catalyst

    Thomas, Renee M.

    2010-11-24

    A highly active enantiopure bimetallic cobalt complex was explored for the enantioselective polymerization of a variety of monosubstituted epoxides. The polymerizations were optimized for high rates and stereoselectivity, with s-factors (kfast/kslow) for most epoxides exceeding 50 and some exceeding 300, well above the threshold for preparative utility of enantiopure epoxides and isotactic polyethers. Values for mm triads of the resulting polymers are typically greater than 95%, with some even surpassing 98%. In addition, the use of a racemic catalyst allowed the preparation of isotactic polyethers in quantitative yields. The thermal properties of these isotactic polyethers are presented, with many polymers exhibiting high T m values. This is the first report of the rapid synthesis of a broad range of highly isotactic polyethers via the enantioselective polymerization of racemic epoxides. © 2010 American Chemical Society.

  1. Epoxide reduction with hydrazine on graphene: a first principles study.

    Kim, Min Chan; Hwang, Gyeong S; Ruoff, Rodney S

    2009-08-14

    Mechanisms for epoxide reduction with hydrazine on a single-layer graphene sheet are examined using quantum mechanical calculations within the framework of gradient-corrected spin-polarized density-functional theory. We find that the reduction reaction is mainly governed by epoxide ring opening which is initiated by H transfer from hydrazine or its derivatives. In addition, our calculations suggest that the epoxide reduction by hydrazine may predominantly follow a direct Eley-Rideal mechanism rather than a Langmuir-Hinshelwood mechanism. We also discuss the generation of various hydrazine derivatives during the reduction of graphene oxide with hydrazine and their potential contribution to lowering the barrier height of epoxide ring opening.

  2. Novel microbial epoxide hydrolases for biohydrolysis of glycidyl derivatives

    Kotík, Michael; Břicháč, Jiří; Kyslík, Pavel

    2005-01-01

    Roč. 120, - (2005), s. 364-375 ISSN 0168-1656 Institutional research plan: CEZ:AV0Z5020903 Keywords : screening * epoxide hydrolase * biotransformation Subject RIV: EE - Microbiology, Virology Impact factor: 2.687, year: 2005

  3. Alternating copolymerization of epoxides with anhydrides initiated by organic bases

    Hošťálek, Z.; Trhlíková, Olga; Walterová, Zuzana; Martinez, T.; Peruch, F.; Cramail, H.; Merna, J.

    2017-01-01

    Roč. 88, March (2017), s. 433-447 ISSN 0014-3057 Institutional support: RVO:61389013 Keywords : copolymerization * epoxides * anhydrides Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 3.531, year: 2016

  4. Enantioselective Epoxide Polymerization Using a Bimetallic Cobalt Catalyst

    Thomas, Renee M.; Widger, Peter C. B.; Ahmed, Syud M.; Jeske, Ryan C.; Hirahata, Wataru; Lobkovsky, Emil B.; Coates, Geoffrey W.

    2010-01-01

    A highly active enantiopure bimetallic cobalt complex was explored for the enantioselective polymerization of a variety of monosubstituted epoxides. The polymerizations were optimized for high rates and stereoselectivity, with s-factors (kfast/kslow) for most epoxides exceeding 50 and some exceeding 300, well above the threshold for preparative utility of enantiopure epoxides and isotactic polyethers. Values for mm triads of the resulting polymers are typically greater than 95%, with some even surpassing 98%. In addition, the use of a racemic catalyst allowed the preparation of isotactic polyethers in quantitative yields. The thermal properties of these isotactic polyethers are presented, with many polymers exhibiting high T m values. This is the first report of the rapid synthesis of a broad range of highly isotactic polyethers via the enantioselective polymerization of racemic epoxides. © 2010 American Chemical Society.

  5. Roles of different forms of cytochrome P450 in the activation of the promutagen 6-aminochrysene to genotoxic metabolites in human liver microsomes.

    Yamazaki, H; Mimura, M; Oda, Y; Inui, Y; Shiraga, T; Iwasaki, K; Guengerich, F P; Shimada, T

    1993-07-01

    activation of 6-aminochrysene in liver microsomes from phenobarbital-treated rats and from human samples HL-4, HL-13 and HL-18 but not HL-16. In contrast, 1,1,1-trichloropropane-2,3-oxide, an inhibitor of epoxide hydrolase activity, enhanced the activation of 6-aminochrysene catalyzed by liver microsomes from beta-naphthoflavone-treated rats and from human samples HL-16 but not HL-4, HL-13 and HL-18. Inclusion of purified rat epoxide hydrolase to the reconstituted system containing rat and human P4501A enzymes caused a decrease in the rates of 6-aminochrysene activation.(ABSTRACT TRUNCATED AT 400 WORDS)

  6. Ovarian Autoantibodies Predict Ovarian Cancer

    2010-11-01

    Expression of thymidine 459 phosphorylase in epithelial ovarian cancer: correlation with angiogenesis, apoptosis , and 460 ultrasound-derived peak...trafficking, activation of S1P1 can promote or inhibit apoptosis of 41 immune cells depending on the balance of cytokines [7]. Knockout of S1P1 (LP(B1...EDG-1) in 42 mice is embryologically lethal [8]. S1P1 also has a role in inflammatory disease such as graft 43 versus host disease and multiple

  7. Microsomal receptor for steroid hormones: functional implications for nuclear activity.

    Muldoon, T G; Watson, G H; Evans, A C; Steinsapir, J

    1988-01-01

    Target tissues for steroid hormones are responsive by virtue of and to the extent of their content of functional intracellular receptors. Recent years have seen a shift in considerations of the cellular dynamics and distribution of these receptors, with current views favoring predominant intranuclear localization in the intact cell. This paper summarizes our analyses of the microsomal estrogen and androgen binding capability of rat uterine and ventral prostate tissue, respectively; these studies have revealed a set of high affinity sites that may act as a conduit for estrogen traversing the cell en route to the nucleus. These sites have many properties in common with cytosolic receptors, with the salient difference of a failure to activate to a more avid DNA-binding form under conditions which permit such activation of cytosolic receptors. The microsomal estrogen-binding proteins also have appreciable affinity for progesterone, another distinction from other known cellular estrogen receptor species. Various experimental approaches were employed to demonstrate that the microsomal receptors were not simply cytosol contaminants; the most convincing evidence is the recent successful separation of the cytosolic and microsomal forms by differential ammonium sulfate precipitation. Discrete subfractionation of subcellular components on successive sucrose gradients, with simultaneous assessments of binding capability and marker enzyme concentrations, indicates that the major portion of the binding is localized within the vesicles of the endoplasmic reticulum free of significant plasma membrane contamination. The microsomal receptors are readily solubilized by extraction with high- or low-salt-containing buffers or with steroid. The residual microsomes following such extraction have the characteristics of saturable acceptor sites for cytosolic estrogen-receptor complexes. The extent to which these sites will accept the cytosolic complexes is equal to the concentration of

  8. Ovarian maldescent

    Trinidad, Carmen; Tardaguila, Francisco; Fernandez, Gabriel C.; Martinez, Concepcion; Chavarri, Elena; Rivas, Isabel [Departments of Radiology and Gynecology, Povisa Medical Center, Salamanca St. 5, 36211, Vigo (Pontevedra) (Spain)

    2004-05-01

    Undescended ovary is a rare disorder that can be associated with muellerian malformations. There is an unclear association with infertility and malignant disease. When an ovary is not in its normal location, it is sought in other locations above the pelvic brim. This is important in cases of undetermined cyclical abdominal pain, follicle aspiration and surgical castration. MRI has proven to be the best imaging method for finding an ovary in an anomalous position and for disregarding associated malformations. We report two patients with unilateral ovarian maldescent, one of them with Rokitansky-Kuester-Hauser syndrome. A review of the literature is included. (orig.)

  9. The iron-responsive microsomal proteome of Aspergillus fumigatus.

    Moloney, Nicola M; Owens, Rebecca A; Meleady, Paula; Henry, Michael; Dolan, Stephen K; Mulvihill, Eoin; Clynes, Martin; Doyle, Sean

    2016-03-16

    Aspergillus fumigatus is an opportunistic fungal pathogen. Siderophore biosynthesis and iron acquisition are essential for virulence. Yet, limited data exist with respect to the adaptive nature of the fungal microsomal proteome under iron-limiting growth conditions, as encountered during host infection. Here, we demonstrate that under siderophore biosynthetic conditions--significantly elevated fusarinine C (FSC) and triacetylfusarinine C (TAFC) production (pproteome remodelling occurs. Specifically, a four-fold enrichment of transmembrane-containing proteins was observed with respect to whole cell lysates following ultracentrifugation-based microsomal extraction. Comparative label-free proteomic analysis of microsomal extracts, isolated following iron-replete and -deplete growth, identified 710 unique proteins. Scatterplot analysis (MaxQuant) demonstrated high correlation amongst biological replicates from each growth condition (Pearson correlation >0.96 within groups; biological replicates (n=4)). Quantitative and qualitative comparison revealed 231 proteins with a significant change in abundance between the iron-replete and iron-deplete conditions (pAspergillus fumigatus must acquire iron to facilitate growth and pathogenicity. Iron-chelating non-ribosomal peptides, termed siderophores, mediate iron uptake via membrane-localised transporter proteins. Here we demonstrate for the first time that growth of A. fumigatus under iron-deplete conditions, concomitant with siderophore biosynthesis, leads to an extensive remodelling of the microsomal proteome which includes significantly altered levels of 231 constituent proteins (96 increased and 135 decreased in abundance), many of which have not previously been localised to the microsome. We also demonstrate the first synthesis of a fluorescent version of fusarinine C, an extracellular A. fumigatus siderophore, and its uptake and localization under iron-restricted conditions. This infers the use of an A. fumigatus

  10. Catalytic asymmetric epoxidation of alpha,beta-unsaturated amides: efficient synthesis of beta-aryl alpha-hydroxy amides using a one-pot tandem catalytic asymmetric epoxidation-Pd-catalyzed epoxide opening process.

    Nemoto, Tetsuhiro; Kakei, Hiroyuki; Gnanadesikan, Vijay; Tosaki, Shin-Ya; Ohshima, Takashi; Shibasaki, Masakatsu

    2002-12-11

    The catalytic asymmetric epoxidation of alpha,beta-unsaturated amides using Sm-BINOL-Ph3As=O complex was succeeded. Using 5-10 mol % of the asymmetric catalyst, a variety of amides were epoxidized efficiently, yielding the corresponding alpha,beta-epoxy amides in up to 99% yield and in more than 99% ee. Moreover, the novel one-pot tandem process, one-pot tandem catalytic asymmetric epoxidation-Pd-catalyzed epoxide opening process, was developed. This method was successfully utilized for the efficient synthesis of beta-aryl alpha-hydroxy amides, including beta-aryllactyl-leucine methyl esters. Interestingly, it was found that beneficial modifications on the Pd catalyst were achieved by the constituents of the first epoxidation, producing a more suitable catalyst for the Pd-catalyzed epoxide opening reaction in terms of chemoselectivity.

  11. UPLC/MS MS data of testosterone metabolites in human and zebrafish liver microsomes and whole zebrafish larval microsomes

    Moayad Saad

    2018-02-01

    Full Text Available This article represents data regarding a study published in Toxicology in vitro entitled “ in vitro CYP-mediated drug metabolism in the zebrafish (embryo using human reference compounds” (Saad et al., 2017 [1]. Data were acquired with ultra-performance liquid chromatography – accurate mass mass spectrometry (UPLC-amMS. A full spectrum scan was conducted for the testosterone (TST metabolites from the microsomal stability assay in zebrafish and humans. The microsomal proteins were extracted from adult zebrafish male (MLM and female (FLM livers, whole body homogenates of 96 h post fertilization larvae (EM and a pool of human liver microsomes from 50 donors (HLM. Data are expressed as the abundance from the extracted ion chromatogram of the metabolites.

  12. Synergistic dual activation catalysis by palladium nanoparticles for epoxide ring opening with phenols.

    Seth, Kapileswar; Roy, Sudipta Raha; Pipaliya, Bhavin V; Chakraborti, Asit K

    2013-07-04

    Synergistic dual activation catalysis has been devised for epoxide phenolysis wherein palladium nanoparticles induce electrophilic activation via coordination with the epoxide oxygen followed by nucleophilic activation through anion-π interaction with the aromatic ring of the phenol, and water (reaction medium) also renders assistance through 'epoxide-phenol' dual activation.

  13. Sulfuric acid as a catalyst for ring-opening of biobased bis-epoxides

    Vegetable oils can be relatively and easily transformed into bio-based epoxides. Because of this, the acid-catalyzed epoxide ring-opening has been explored for the preparation of bio-based lubricants and polymers. Detailed model studies are carried out only with mono-epoxide made from methyl oleate,...

  14. Biocompatibility of epoxidized styrene-butadiene-styrene block copolymer membrane

    Yang, Jen Ming; Tsai, Shih Chang

    2010-01-01

    Styrene-butadiene-styrene block copolymer (SBS) membrane was prepared by solution casting method and then was epoxidized with peroxyformic acid generated in situ to yield the epoxidized styrene-butadiene-styrene block copolymer membrane (ESBS). The structure and properties of ESBS were characterized with infrared spectroscopy, Universal Testing Machine, differential scanning calorimetry (DSC), and thermogravimetry analysis (TGA). The performances of contact angle, water content, protein adsorption, and water vapor transmission rate on ESBS membrane were determined. After epoxidation, the hydrophilicity of the membrane increased. The water vapor transmission rate of ESBS membrane is similar to human skin. The biocompatibility of ESBS membrane was evaluated with the cell culture of fibroblasts on the membrane. It revealed that the cells not only remained viable but also proliferated on the surface of the various ESBS membranes and the population doubling time for fibroblast culture decreased.

  15. Electrocatalytic aerobic epoxidation of alkenes: Experimental and DFT investigation

    Magdesieva, Tatiana V.; Borisova, Nataliya E.; Dolganov, Alexander V.; Ustynyuk, Yuri A.

    2012-01-01

    A new method for electrocatalytic aerobic epoxidation of alkenes catalyzed by binuclear Cu(II) complexes with azomethine ligands based on 2,6-diformyl-4-tert-butylphenol is described. In acetonitrile–water (5%), at the potential of Cu II /Cu I redox couple (–0.8 V vs. Ag/AgCl/KCl) at room temperature the epoxide is obtained in an average yield of around 50%. Contrary to the majority of known epoxidations, no strong oxidants are involved and no free hydrogen peroxide is formed in the reaction, thus making it ecologically friendly. The DFT quantum-chemical modeling of the reaction mechanism revealed that a copper hydroperoxo-complex rather than hydrogen peroxide or a copper oxo-complex oxidizes alkene. The process is very selective since neither products of hydroxylation of benzene ring in styrene nor of allylic oxidation of cyclohexene were detected.

  16. Synthesis and Tribological Studies of Branched Alcohol Derived Epoxidized Biodiesel

    Qinggong Ren

    2015-09-01

    Full Text Available The optimization and kinetics of the ring-opening reaction of an epoxidized biodiesel (epoxidized rapeseed oil methyl ester (EBD with 2-ethyl hexanol (2-EH were studied. The determined optimum conditions were 4:1 2-EH/oil molar ratio, 90 °C, 18 h, and 7 wt % of Amberlyst D001 (dry catalyst; the product’s oxirane oxygen content was 0.081% with 38.32 mm2/s viscosity at 40 °C. The catalyst retained its high catalytic power after recycling five times. Furthermore, the determined non-catalyzed activation energy was 76 kJ·mol−1 and 54 kJ·mol−1 with the D001 resin catalyst. The product’s chemical structure was investigated through FT-IR and 1H NMR. The viscosity, flash point, pour point, and anti-wear properties of the product were improved compared with those of epoxidized biodiesel.

  17. The oxidation of copper catalysts during ethylene epoxidation.

    Greiner, M T; Jones, T E; Johnson, B E; Rocha, T C R; Wang, Z J; Armbrüster, M; Willinger, M; Knop-Gericke, A; Schlögl, R

    2015-10-14

    The oxidation of copper catalysts during ethylene epoxidation was characterized using in situ photoemission spectroscopy and electron microscopy. Gas chromatography, proton-transfer reaction mass spectrometry and electron-ionization mass spectrometry were used to characterize the catalytic properties of the oxidized copper. We find that copper corrodes during epoxidation in a 1 : 1 mixture of oxygen and ethylene. The catalyst corrosion passes through several stages, beginning with the formation of an O-terminated surface, followed by the formation of Cu2O scale and eventually a CuO scale. The oxidized catalyst exhibits measurable activity for ethylene epoxidation, but with a low selectivity of 8/2500) Cu2O forms and eventually covers the surface.

  18. Epoxidation of limonene over Ti MCM 41 and Ti BETA

    Cubillos Lobo, Jairo Antonio; Gonzalez Rodriguez, Lina Maria; Montes de Correa, Consuelo

    2002-01-01

    Ti MCM 41 were synthesized and evaluated in the epoxidation of limonene, using peroxide of hydrogen (H 2 O) as agent oxidizer. The characteristic hexagonal phase of Ti MCM 41 was obtained by heating the precursor gel during three days at 100 centigrade degrees. Further heating up to ten days leads to a decrease of this phase. The increase (Ti) in the synthesis gel also decreases that phase. The increase of Ti in the synthesis gel also decreases that phase UV VIS and FTIR spectroscopy indicates that Ti was incorporated in the lattice of Ti MCM 41 as well as, in Ti BETA. SEM micrographs of Ti MCM 41 show that the morphology changes with the Ti loading. Ti MCM 41 was most active than Ti BETA for limonene epoxidation even though both show high selectivity to epoxides

  19. A strategy for position-selective epoxidation of polyprenols.

    Gnanadesikan, Vijay; Corey, E J

    2008-06-25

    An effective strategy has been developed for the efficient site-selective epoxidation of poylolefinic isoprenoid alcohols, based on the use of an internal control element for intramolecular reaction. The approach is illustrated by application to a series of polyisoprenoid alcohols (polyprenols) at substrate concentration of 0.5 mM. With polyprenol substrates having the hydroxyl function at one terminus, the internal epoxidation can be directed at the double bond of the polyprenol, which is either four or five away from the terminal hydroxyprenyl subunit.

  20. Omeprazole increases the efficacy of a soluble epoxide hydrolase inhibitor in a PGE{sub 2} induced pain model

    Goswami, Sumanta Kumar; Inceoglu, Bora; Yang, Jun; Wan, Debin; Kodani, Sean D. [Department of Entomology and Nematology, UC Davis Comprehensive Cancer Center, University of California, Davis, CA (United States); Trindade da Silva, Carlos Antonio [Department of Entomology and Nematology, UC Davis Comprehensive Cancer Center, University of California, Davis, CA (United States); Department of Genetics and Biochemistry, Federal University of Uberlandia, MG (Brazil); Morisseau, Christophe [Department of Entomology and Nematology, UC Davis Comprehensive Cancer Center, University of California, Davis, CA (United States); Hammock, Bruce D., E-mail: bdhammock@ucdavis.edu [Department of Entomology and Nematology, UC Davis Comprehensive Cancer Center, University of California, Davis, CA (United States)

    2015-12-15

    Epoxyeicosatrienoic acids (EETs) are potent endogenous analgesic metabolites produced from arachidonic acid by cytochrome P450s (P450s). Metabolism of EETs by soluble epoxide hydrolase (sEH) reduces their activity, while their stabilization by sEH inhibition decreases both inflammatory and neuropathic pain. Here, we tested the complementary hypothesis that increasing the level of EETs through induction of P450s by omeprazole (OME), can influence pain related signaling by itself, and potentiate the anti-hyperalgesic effect of sEH inhibitor. Rats were treated with OME (100 mg/kg/day, p.o., 7 days), sEH inhibitor TPPU (3 mg/kg/day, p.o.) and OME (100 mg/kg/day, p.o., 7 days) + TPPU (3 mg/kg/day, p.o., last 3 days of OME dose) dissolved in vehicle PEG400, and their effect on hyperalgesia (increased sensitivity to pain) induced by PGE{sub 2} was monitored. While OME treatment by itself exhibited variable effects on PGE{sub 2} induced hyperalgesia, it strongly potentiated the effect of TPPU in the same assay. The significant decrease in pain with OME + TPPU treatment correlated with the increased levels of EETs in plasma and increased activities of P450 1A1 and P450 1A2 in liver microsomes. The results show that reducing catabolism of EETs with a sEH inhibitor yielded a stronger analgesic effect than increasing generation of EETs by OME, and combination of both yielded the strongest pain reducing effect under the condition of this study. - Highlights: • The soluble epoxide hydrolase (sEH) inhibitor TPPU is anti-hyperalgesic. • Omeprazole potentiates the anti-hyperalgesic actions of TPPU. • This potentiation is associated with increased P450 activity. • The potentiation is associated with an increase in fatty acid epoxide/diol ratio. • Joint use of sEH inhibitors and P450 inducers could result in drug–drug interactions.

  1. Hepatic mitochondrial and microsomal recovery of rats intoxicated with CCl/sub 4/

    Hasegawa, T.; Hirai, Y.; Koga, N.; Tomokuni, K.

    1983-01-01

    The hepatic mitochondrial and microsomal recovery of rats intoxicated with CCl/sub 4/ was investigated with specific reference to the oxygen utilization of liver slices. In control rats, the major oxygen utilization of the liver slices was attributed to mitochondrial particles. Since the mitochondrial oxygen utilization was inhibited by cyanide, the microsomal oxygen utilization was induced by NADPH and phenobarbital (a substrate for microsomal mixed function oxidase). Changes in oxygen utilization were observed in the recovery course of rats intoxicated with CCl/sub 4/, and the recovery of mitochondria was found to be faster than that of microsomes. A sex difference was present in the recovery mechanism of the microsomes.

  2. Primary ovarian leiomyoma

    Mathew, Marian; Krolikowski, Anderzj; Al-Haddabi, Ibrahim; Nirmala, Vadakkepat

    2005-01-01

    Ovarian leiomyoma is a rare and incidentally detected neoplasm, clinically indistinguishable from subserous leiomyomas and ovarian fibromas, until histopathological confirmation. We present a case of leiomyoma arising primarily from the ovary in a 35 year old woman. (author)

  3. Ovarian cancer and smoking

    Beral, V; Gaitskell, K; Hermon, C

    2012-01-01

    Smoking has been linked to mucinous ovarian cancer, but its effects on other ovarian cancer subtypes and on overall ovarian cancer risk are unclear, and the findings from most studies with relevant data are unpublished. To assess these associations, we review the published and unpublished evidence....

  4. Bakers yeast-mediated transformations of alpha-keto epoxides

    Meth-Cohn, O

    1994-06-07

    Full Text Available Alpha beta-Epoxy ketones on treatment with baker's yeast yield different types of products depending on their substitution. Small groups such as H or Me attached at the epoxy end protect that end from attack. Thus, 1-acyl epoxides with H, methyl...

  5. Enzymatic epoxidation of biodiesel optimized by response surface ...

    During the enzymatic epoxidation of biodiesel, stearic acid was selected as oxygen carrier. Enzyme screening and the load of stearic acid were investigated. The effects of four main reaction conditions including reaction time, temperature, enzyme load, and mole ratio of H2O2/C=C-bonds on the epoxy oxygen group content ...

  6. Effects of experimental variables on the degree of epoxidation of ...

    Results show that the acid treatment of the bentonite clay improved its support characteristics by achieving some increase in surface area and optimum treatment condition was found to be 10g bentonite clay treated with 30cm3 sulphuric acid for 6 hours. It was found that higher epoxidation was achieved with treated ...

  7. Properties of epoxide hydrolase from the yeast Rhodotorula glutinis

    Ariës-Kronenburg, N.A.E.

    2002-01-01

    Epoxide hydrolases are ubiquitous enzymes that can be found in nearly all living organisms. Some of the enzymes play an important role in detoxifying xenobiotic and metabolic compounds. Others are important in the growth of organisms like

  8. Epoxidation and oxidation reactions using 1,4-butanediol ...

    Unknown

    and aryl halides to hydroxy compounds through a .... Epoxidation of olefins using 1,4-BDDMA-crosslinked polystyrene supported t- butyl hydroperoxide. Reaction. Isolated. Olefina timeb (h). Productc yield (%). Cinnamic acid. 39 ... aCinnamic acid; bcyclohexene; csubstrate to resin 1 : 2; solvent, dioxan, temperature, 70°C.

  9. Highly efficient epoxidation of alkenes with m-chloroperbenzoic acid ...

    on a solid support such as polymer, zeolite and silica have recently been reported as innovation in the cat- alytic properties of such compounds.19 23 ..... the homogeneous phases, the Co(III) complex was used ..... solvent-extraction and catalase-like activity studies J. ... 15 as highly active catalysts for epoxidation of styrene.

  10. Propene epoxidation over Au/Ti-SBA-15 catalysts

    Sacaliuc, E.; Beale, A.M.; Weckhuysen, B.M.; Nijhuis, T.A.

    2007-01-01

    Highly dispersed gold nanoparticles were synthesized within the channels of a mesoporous Ti-SBA-15 support, followed by thorough catalyst characterization and testing in the selective epoxidation of propene to propene oxide. For this purpose, two series of Ti-SBA-15 materials differing in their Ti

  11. Synthesis of Dinaphtho-dioxaphosphocin-8-oxides, Epoxides and ...

    South African Journal of Chemistry ... Preparation of 8-substituted-16H-dinaphtho [2,1-d:1',2'-g] [1,3,2] dioxaphosphocin 8-oxides (5a–g) with an eight-membered phosphorus heterocyclic system (2) and their epoxides and bisphosphonates ... Some of these compounds are found to possess moderate antimicrobial activity.

  12. Synthesis of aluminum nanoparticles capped with copolymerizable epoxides

    Thomas, Brandon J. [Saint Louis University, Department of Chemistry (United States); Bunker, Christopher E. [Air Force Research Laboratory, Wright-Patterson Air Force Base, Propulsion Directorate (United States); Guliants, Elena A. [University of Dayton Research Institute, Department of Electrical and Computer Engineering (United States); Hayes, Sophia E. [Washington University, Department of Chemistry (United States); Kheyfets, Arthur [Saint Louis University, Department of Chemistry (United States); Wentz, Katherine M. [Washington University, Department of Chemistry (United States); Buckner, Steven W., E-mail: buckners@slu.edu; Jelliss, Paul A., E-mail: jellissp@slu.edu [Saint Louis University, Department of Chemistry (United States)

    2013-06-15

    We report on the synthesis of air-stable aluminum nanoparticles (Al NPs) capped with 1,2-epoxy-9-decene. Long-chain epoxides have proven to be effective capping agents for Al NPs as the epoxide ring is highly susceptible to ring-opening polymerization, leading to the formation of putative polyether loops on the nascent Al NP surface. However, these materials are observed to degrade within several hours to days following exposure to ambient air. By inducing polymerization of the additional terminal alkene functionality on the epoxide, we have produced Al NPs that exhibit both a shelf life of {approx}6 weeks and a high active Al content. Transmission electron microscopy confirms that these spherical nanostructures, {approx}25 nm in diameter, are embedded in a covalently bound polymer matrix that serves as a prophylactic barrier against water/air (H{sub 2}O/O{sub 2}) degradation, and {sup 27}Al solid-state NMR is used to nondestructively confirm the presence of both metallic Al{sup 0} and oxidized Al{sup 3+}. In addition, we have induced polymerization of the epoxide terminal alkene functionality with a long-chain diene monomer, 1,13-tetradecadiene, leading to the formation of Al NPs protected by an extremely hydrophobic polymer matrix. These core-shell nanomaterials also have high active Al contents along with extremely long shelf lives (up to 6 months upon air exposure).

  13. Epoxidation of bulky organic molecules over pillared titanosilicates

    Přech, Jan; Eliášová, Pavla; Aldhayan, D.; Kubů, Martin

    2015-01-01

    Roč. 243, APR 2014 (2015), s. 134-140 ISSN 0920-5861 R&D Projects: GA ČR GBP106/12/G015 Institutional support: RVO:61388955 Keywords : Cyclooctene * Epoxidation * Layered TS-1 zeolite Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.312, year: 2015

  14. New mechanistic insight in the gold-based propene epoxidation

    Parvulescu, E.

    2009-01-01

    Propene oxide is a very important intermediate for the synthesis of commercial products, including adhesives, paints, and cosmetics. The gas-phase epoxidation of propene over Au/Ti-based catalysts is an intriguing scientific topic, not only because of the industrial importance of the production of

  15. Effect of epoxidation level on thermal properties and ionic conductivity of epoxidized natural rubber solid polymer nanocomposite electrolytes

    Harun, Fatin; Chan, Chin Han; Winie, Tan [Faculty of Applied Sciences, UniversitiTeknologi MARA (UiTM), Shah Alam, 40450 Selangor Darul Ehsan (Malaysia); Sim, Lai Har; Zainal, Nurul Fatahah Asyqin [Center of Foundation Studies, PuncakAlam Campus, UniversitiTeknologi MARA, 40430 Selangor Darul Ehsan (Malaysia)

    2015-08-28

    Effect of epoxide content on the thermal and conductivity properties of epoxidized natural rubber (ENR) solid polymer nanocomposite electrolytes was investigated. Commercial available epoxidized natural rubber having 25 (ENR25) and 50 mole% (ENR50) epoxide, respectively were incorporated with lithium perchlorate (LiClO{sub 4}) salt and titanium dioxide (TiO{sub 2}) nanofiller via solution casting method. The solid polymer nanocomposite electrolytes were characterized by differential scanning calorimetry (DSC) and impedance spectroscopy (IS) for their thermal properties and conductivity, respectively. It was evident that introduction of LiClO{sub 4} causes a greater increase in glass transition temperature (T{sub g}) and ionic conductivity of ENR50 as compared to ENR25. Upon addition of TiO{sub 2} in ENR/LiClO{sub 4} system, a remarkable T{sub g} elevation was observed for both ENRs where ENR50 reveals a more pronounced changes. It is interesting to note that they exhibit different phenomenon in ionic conductivity with TiO{sub 2} loading where ENR25 shows enhancement of conductivity while ENR50 shows declination.

  16. In vitro biotransformation of flavonoids by rat liver microsomes

    Nielsen, S. E.; Breinholt, V.; Justesen, U.

    1998-01-01

    1. Sixteen naturally occurring flavonoids were investigated as substrates for cytochrome P450 in uninduced and Aroclor 1254-induced rat liver microsomes. Naringenin, hesperetin, chrysin, apigenin, tangeretin, kaempferol, galangin and tamarixetin were all metabolized extensively by induced rat liver...... pathway leading to the corresponding 3',4'-dihydroxylated flavonoids either by hydroxylation or demethylation. Structural requirements for microsomal hydroxylation appeared to be a single or no hydroxy group on the B-ring of the flavan nucleus. The presence of two or more hydroxy groups on the B......-ring seemed to prevent further hydroxylation. The results indicate that demethylation only occurs in the B-ring when the methoxy group is positioned at C-4'-, and not at the C-3'-position. 3. The CYP1A isozymes were found to be the main enzymes involved in flavonoid hydroxylation, whereas other cytochrome P...

  17. Evaluation of the ovarian reserve in women transplanted with frozen and thawed ovarian cortical tissue

    Greve, Tine; Schmidt, Kirsten Tryde; Kristensen, Stine Gry

    2012-01-01

    To investigate ovarian reserve and ovarian function in women transplanted with frozen/thawed ovarian tissue.......To investigate ovarian reserve and ovarian function in women transplanted with frozen/thawed ovarian tissue....

  18. Microsomal protein synthesis inhibition: an early manifestation of gentamicin nephrotoxicity

    Bennett, W.M.; Mela-Riker, L.M.; Houghton, D.C.; Gilbert, D.N.; Buss, W.C.

    1988-01-01

    Aminoglycoside antibiotics achieve bacterial killing by binding to bacterial ribosomes and inhibiting protein synthesis. To examine whether similar mechanisms could be present in renal tubular cells prior to the onset of overt proximal tubular necrosis due to these drugs, we isolated microsomes from Fischer rats given 20 mg/kg gentamicin every 12 h subcutaneously for 2 days and from vehicle-injected controls. Concomitant studies of renal structure, function, and mitochondrial respiration were carried out. [3H]leucine incorporation into renal microsomes of treated animals was reduced by 21.9% (P less than 0.01), whereas brain and liver microsomes from the same animals were unaffected. Gentamicin concentration in the renal microsomal preparation was 56 micrograms/ml, a value 7- to 10-fold above concentrations necessary to inhibit bacterial growth. Conventional renal function studies were normal (blood urea, serum creatinine, creatinine clearance). Treated animals showed only a mild reduction of inulin clearance, 0.71 compared with 0.93 ml.min-1.100 g-1 in controls (P less than 0.05), and an increase in urinary excretion of N-acetylglucosaminidase of 20 compared with 14.8 units/l (P less than 0.05). Renal slice transport of p-aminohippuric acid, tetraethylammonium, and the fractional excretion of sodium were well preserved. There was no evidence, as seen by light microscopy, of proximal tubular necrosis. Mitochondrial cytochrome concentrations were normal and respiratory activities only slightly reduced. Processes similar to those responsible for bacterial killing could be involved in experimental gentamicin nephrotoxicity before overt cellular necrosis

  19. Oxidation of esterified arachidonate by rat liver microsomes

    Davis, H.W.; Suzuki, T.; Schenkman, J.B.

    1986-01-01

    The authors have previously demonstrated a relationship between phospholipid arachidonate in liver microsomes and malondialdehyde (MDA) formation during lipid peroxidation. In this study arachidonic acid (U- 14 C) was incorporated into rat liver microsomes and NADPH-supported peroxidation was carried out at 37 0 C for 15 minutes. The microsomes were pelleted by centrifugation and the labeled products in the supernatant were isolated by a solid phase method. Pellets were hydrolyzed with phospholipase A 2 and extracted with diethyl ether and the products from both fractions were separated by reverse phase HPLC. The results show that (1) oxidation occurs in all of the major phospholipids but that phosphatidylethanolamine is the most susceptible; (2) a linear correlation exists between MDA formation and supernatant radioactivity; (3) several different polar products are found in both the supernatant and the hydrolyzed pellet but that the ratios of product peaks in HPLC do not change during the peroxidation, indicating no secondary metabolism or propagation; and (4) cytochrome P-450 is not involved in the peroxidative reactions since no oxidation occurs in the absence of Fe 3+ and since product formation is unaffected in the presence of carbon monoxide

  20. Evaluation of fish models of soluble epoxide hydrolase inhibition.

    Newman, J W; Denton, D L; Morisseau, C; Koger, C S; Wheelock, C E; Hinton, D E; Hammock, B D

    2001-01-01

    Substituted ureas and carbamates are mechanistic inhibitors of the soluble epoxide hydrolase (sEH). We screened a set of chemicals containing these functionalities in larval fathead minnow (Pimphales promelas) and embryo/larval golden medaka (Oryzias latipes) models to evaluate the utility of these systems for investigating sEH inhibition in vivo. Both fathead minnow and medaka sEHs were functionally similar to the tested mammalian orthologs (murine and human) with respect to substrate hydrol...

  1. A New Mn–Salen Micellar Nanoreactor for Enantioselective Epoxidation of Alkenes in Water

    Francesco P. Ballistreri

    2018-03-01

    Full Text Available A new chiral Mn–salen catalyst, functionalized with a long aliphatic chain and a choline group, able to act as surfactant catalyst for green epoxidation in water, is here described. This catalyst was employed with a commercial surfactant (CTABr leading to a nanoreactor for the enantioselective epoxidation of some selected alkenes in water, using NaClO as oxidant. This is the first example of a nanoreactor for enantioselective epoxidation of non-functionalized alkenes in water.

  2. Markedly Elevated Carbamazepine-10,11-epoxide/Carbamazepine Ratio in a Fatal Carbamazepine Ingestion

    Jason L. Russell

    2015-01-01

    Full Text Available Carbamazepine is a widely used anticonvulsant. Its metabolite, carbamazepine-10,11-epoxide, has been found to display similar anticonvulsant and neurotoxic properties. While the ratio of parent to metabolite concentration varies significantly, at therapeutic doses the epoxide concentration is generally about 20% of the parent. We report a case of fatal carbamazepine overdose in which the epoxide metabolite concentration was found to be 450% higher than the parent compound, suggesting a potential role for metabolite quantification in severe toxicity.

  3. Lysophosphatidic acids are new substrates for the phosphatase domain of soluble epoxide hydrolase[S

    Oguro, Ami; Imaoka, Susumu

    2012-01-01

    Soluble epoxide hydrolase (sEH) is a bifunctional enzyme that has a C-terminus epoxide hydrolase domain and an N-terminus phosphatase domain. The endogenous substrates of epoxide hydrolase are known to be epoxyeicosatrienoic acids, but the endogenous substrates of the phosphatase activity are not well understood. In this study, to explore the substrates of sEH, we investigated the inhibition of the phosphatase activity of sEH toward 4-methylumbelliferyl phosphate by using lecithin and its hyd...

  4. Preliminary studies of epoxidized palm oil as sizing chemical for carbon fibers

    Salleh, S.N.M.; Ubaidillah, E.A.E.; Abidin, M.F.Z.

    2010-01-01

    Epoxidized palm oil is derived from palm oil through chemical reaction with peracetic acid. Preliminary studies to coat carbon fibers have shown promising result towards applying natural product in carbon fibre composites. Mechanical studies of sized carbon fibers with epoxidized palm oil showed significant increase in tensile and interfacial shear strength. Surface morphology of sized or coated carbon fibers with epoxidized palm oil reveals clear increase in root means square-roughness (RMS). This indicates the change of the surface topography due to sized or coated carbon fibers with epoxidized palm oil. (author)

  5. Epoxide hydrolase-lasalocid a structure provides mechanistic insight into polyether natural product biosynthesis.

    Wong, Fong T; Hotta, Kinya; Chen, Xi; Fang, Minyi; Watanabe, Kenji; Kim, Chu-Young

    2015-01-14

    Biosynthesis of some polyether natural products involves a kinetically disfavored epoxide-opening cyclic ether formation, a reaction termed anti-Baldwin cyclization. One such example is the biosynthesis of lasalocid A, an ionophore antibiotic polyether. During lasalocid A biosynthesis, an epoxide hydrolase, Lsd19, converts the bisepoxy polyketide intermediate into the tetrahydrofuranyl-tetrahydropyran product. We report the crystal structure of Lsd19 in complex with lasalocid A. The structure unambiguously shows that the C-terminal domain of Lsd19 catalyzes the intriguing anti-Baldwin cyclization. We propose a general mechanism for epoxide selection by ionophore polyether epoxide hydrolases.

  6. Premature ovarian failure

    Persani Luca

    2006-04-01

    Full Text Available Abstract Premature ovarian failure (POF is a primary ovarian defect characterized by absent menarche (primary amenorrhea or premature depletion of ovarian follicles before the age of 40 years (secondary amenorrhea. It is a heterogeneous disorder affecting approximately 1% of women e.g. Turner syndrome represent the major cause of primary amenorrhea associated with ovarian dysgenesis. Despite the description of several candidate genes, the cause of POF remains undetermined in the vast majority of the cases. Management includes substitution of the hormone defect by estrogen/progestin preparations. The only solution presently available for the fertility defect in women with absent follicular reserve is ovum donation.

  7. Kinetics of naphthalene metabolism in target and non-target tissues of rodents and in nasal and airway microsomes from the Rhesus monkey

    Buckpitt, Alan, E-mail: arbuckpitt@ucdavis.edu [Department of Molecular Biosciences, School of Veterinary Medicine, UC Davis, Davis, CA 95616 (United States); Morin, Dexter [Department of Molecular Biosciences, School of Veterinary Medicine, UC Davis, Davis, CA 95616 (United States); Murphy, Shannon; Edwards, Patricia; Van Winkle, Laura [Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, UC Davis, Davis, CA 95616 (United States); Center for Health and the Environment, UC Davis, Davis, CA 95616 United States (United States)

    2013-07-15

    Naphthalene produces species and cell selective injury to respiratory tract epithelial cells of rodents. In these studies we determined the apparent K{sub m}, V{sub max}, and catalytic efficiency (V{sub max}/K{sub m}) for naphthalene metabolism in microsomal preparations from subcompartments of the respiratory tract of rodents and non-human primates. In tissues with high substrate turnover, major metabolites were derived directly from naphthalene oxide with smaller amounts from conjugates of diol epoxide, diepoxide, and 1,2- and 1,4-naphthoquinones. In some tissues, different enzymes with dissimilar K{sub m} and V{sub max} appeared to metabolize naphthalene. The rank order of V{sub max} (rat olfactory epithelium > mouse olfactory epithelium > murine airways ≫ rat airways) correlated well with tissue susceptibility to naphthalene. The V{sub max} in monkey alveolar subcompartment was 2% that in rat nasal olfactory epithelium. Rates of metabolism in nasal compartments of the monkey were low. The catalytic efficiencies of microsomes from known susceptible tissues/subcompartments are 10 and 250 fold higher than in rat airway and monkey alveolar subcompartments, respectively. Although the strong correlations between catalytic efficiencies and tissue susceptibility suggest that non-human primate tissues are unlikely to generate metabolites at a rate sufficient to produce cellular injury, other studies showing high levels of formation of protein adducts support the need for additional studies. - Highlights: • Naphthalene is metabolized with high catalytic efficiency in susceptible tissue. • Naphthalene is metabolized at low catalytic efficiency in non-susceptible tissue. • Respiratory tissues of the non human primate metabolize naphthalene slowly.

  8. Microsomal prostaglandin E synthase-1 in rheumatic diseases

    Marina eKorotkova

    2011-01-01

    Full Text Available Microsomal prostaglandin E synthase-1 (mPGES-1 is a well recognized target for the development of novel anti-inflammatory drugs that can reduce symptoms of inflammation in rheumatic diseases and other inflammatory conditions. In this review, we focus on mPGES-1 in rheumatic diseases with the aim to cover the most recent advances in the understanding of mPGES-1 in rheumatoid arthritis, osteoarthritis and inflammatory myopathies. Novel findings regarding regulation of mPGES1 cell expression as well as enzyme inhibitors are also summarized.

  9. Ectopic ovarian pregnancy

    Sachdev, P.S.; Jatoi, N.; Memon, R.A.; Sachdev, C.S.

    2003-01-01

    A case of ectopic ovarian pregnancy is presented occurring in a 24 years old woman after natural conception. The clinical diagnosis was ruptured tubal pregnancy. Gross findings were suggestive of ruptured corpus luteum cyst on exploration. The histopathological examination of specimen brought forward the diagnosis of ovarian pregnancy. (author)

  10. Autoimmune premature ovarian failure

    Beata Komorowska

    2017-02-01

    Full Text Available Premature ovarian failure (POF, also termed as primary ovarian insufficiency (POI, is a highly heterogenous condition affecting 0.5-3.0% of women in childbearing age. These young women comprise quite a formidable group with unique physical and psychological needs that require special attention. Premature ovarian senescence (POS in all of its forms evolves insidiously as a basically asymptomatic process, leading to complete loss of ovarian function, and POI/POF diagnoses are currently made at relatively late stages. Well-known and well-documented risk factors exist, and the presence or suspicion of autoimmune disorder should be regarded as an important one. Premature ovarian failure is to some degree predictable in its occurrence and should be considered while encountering young women with loss of menstrual regularity, especially when there is a concomitant dysfunction in the immune system.

  11. Prevention of ovarian cancer.

    Hanna, Louise; Adams, Malcolm

    2006-04-01

    Ovarian cancer is the leading cause of death from gynaecological malignancy. The incidence is high in the Western world. The incidence of ovarian cancer is reduced by pregnancy, lactation, the oral contraceptive pill and tubal ligation. Lifestyle factors are important in the aetiology of ovarian cancer and current evidence suggests the risk can be reduced by eating a diet rich in fruit and vegetables, taking regular exercise, avoiding smoking, avoiding being overweight and avoiding long-term use of hormonal replacement therapy (HRT). Familial ovarian cancer is responsible for about 10% of ovarian cancer cases. Strategies available to high-risk women include screening (covered elsewhere) and prophylactic salpingo-oophorectomy. The precise role of chemoprevention for high-risk women in the form of the oral contraceptive pill is unclear.

  12. Modification of olefinic double bonds of unsaturated fatty acids and other vegetable oil derivatives via epoxidation: A review

    Noor Armylisas, A.H.; Siti Hazirah, M.F.; Yeong, S.K.; Hazimah, A.H.

    2017-01-01

    The highly strained ring in epoxides makes these compounds very versatile intermediates. Epoxidized vegetable oils are gaining a lot of attention as renewable and environmentally friendly feedstock with various industrial applications such as plasticizers, lubricant base oils, surfactants, etc. Numerous papers have been published on the development of the epoxidation methods and the number is still growing. This review reports the synthetic approaches and applications of epoxidized vegetable oils. [es

  13. Stereospecificity (ST) of the microsomal ethanol oxidizing system (MEOS)

    Alderman, J.; Kato, S.; Lasker, J.; Lieber, C.S.

    1987-01-01

    The ST of MEOS for the ethanol 1R hydrogen has been variously reported as absolute, partial or absent, with free radical involvement postulated in the latter case. To determine both the ST of MEOS and the participation of free radicals in the reaction, they investigated MEOS ST using 1R[1- 3 H] ethanol as substrate. ST is expressed as the fraction of 3 H labeling in acetaldehyde formed, relative to that in ethanol, and ranges from 0.5 to 0. Partial ST was observed using liver microsomes from both rats and hamsters; it significantly decreased after ethanol feeding. 0.1 mM desferrioxamine (dfx) did not increase ST in any of these microsomal preparations while ferric EDTA decreased it, suggesting that ethanol treatment induces a cytochrome P-450 with lower ST rather than increasing free radical involvement. This is supported by a virtual absence of ST observed in a reconstituted system containing purified hamster P-450/sub ALC/, a liver cytochrome P-450 isozyme induced in hamsters by ethanol treatment. Their results indicate that, unlike other enzymes that oxidize ethanol, MEOS has only partial ST. Thus, ST alone cannot be used as an index of free radical involvement but, when evaluated with the response of ST to dfx, it indicated that MEOS is unlikely to involve free radical attack on ethanol in solution

  14. PHOTOMETRIC EVIDENCE FOR THE OSMOTIC BEHAVIOR OF RAT LIVER MICROSOMES

    Tedeschi, Henry; James, Joseph M.; Anthony, William

    1963-01-01

    Electron microscope observations are consistent with the interpretation that the elements of the endoplasmic reticulum are osmotically active in situ as well as after isolation. More recently, it has been reported that microsomal suspensions equilibrate almost completely with added C14-sucrose and that no osmotic behavior is evident from photometric data. These findings were considered at variance with the electron microscope data. However, equilibration with added label simply attests to a relatively high permeability, and, in addition, the photometric data need not be critical. Osmotic volume changes, measured photometrically, may be masked by concomitant events (e.g., changes in the refractive index of the test solutions at varying osmotic pressures, breakdown of the particles, and agglutination). For these reasons the photometric experiments were repeated. In this work, the reciprocal of optical density of microsomal suspensions was found to vary linearly with the reciprocal of concentration of the medium at constant refractive index. These changes probably correspond to osmotic volume changes, since the effect was found to be (a) independent of substance used and (b) osmotically reversible. The transmission of the suspension was found to vary with the refractive index of the medium, the concentration of particles, and the wavelength of incident light, according to relationships that are similar to or identical with those obtained for mitochondrial suspensions. PMID:14064105

  15. Effect of ethionine on hepatic mitochondrial and microsomal calcium uptake

    Agarwal, A.K.; Zinermon, W.D.; Latoni, L.

    1988-01-01

    Ethionine, an ethyl analog of methionine, produces a variety of physiological and pathological effects in animals. These range from acute effects in the liver, kidney, pancreas, and other organs to liver carcinogenesis. Female rats when injected with ethionine exhibit a rapid decrease in hepatic adenosine triphosphate levels followed by a marked inhibition of RNA and protein synthesis and accumulation of triglycerides. Since calcium transport in mitochondria and microsomes is ATP dependent, it becomes interesting to find out if ethionine administration has any effect on subcellular calcium transport. Calcium has recently gained an increased controversy regarding its role in chemical induced lethal cell damage. Certain groups believe that influx of extracellular calcium across the damaged plasma membrane might actually mediate the irreversible damage to the cell, whereas according to other, entry of calcium into the cell is secondary to the damage. The present study was carried out to investigate the calcium [ 45 Ca] transport in mitochondria and microsomes following ethionine administration. The effect of carbon tetrachloride on calcium uptake in ethionine treated rats was also studied

  16. Calmodulin stimulation of calcium transport in carrot microsomal vesicles

    Pierce, W.S.; Sze, H.

    1987-01-01

    ATP-dependent 45 Ca 2+ uptake into microsomal vesicles isolated from cultured carrot cells (Daucus carota Danvers) was stimulated 2-3 fold by 5 ug/ml calmodulin (CaM). Microsomal vesicles separated with a linear sucrose gradient showed two peaks with CaM-stimulated Ca 2+ uptake activities. One peak (at 1.12 g/cc) comigrated with the activity of the antimycin A-insensitive NADH-dependent cytochrome c reductase. This transport activity was enhanced 10-20 fold by 10 mM oxalate and appeared to be associates with vesicles derived primarily from the ER. The other peak of CaM-stimulated Ca 2+ uptake (at 1.17 g/cc) was not affected by oxalate. These vesicles are probably derived from the plasma membrane. Preliminary experiments with the low-density vesicles (ER) vesicles, indicate that inositol-1,4,5-trisphosphate caused a transient reduction in intravesicular Ca 2+ . These results are consistent with the ER being an important site of intracellular Ca 2+ regulation

  17. Studies on the transverse localization of lysophospholipase II in bovine liver microsomes by immunological techniques

    Moonen, H.; Bosch, H. van den

    1979-01-01

    1. 1. Lysophospholipase activity solubilized from bovine liver microsomes could be precipitated for more than 80% by antibodies evoked in rabbits against the purified bovine liver lysophospholipase II. 2. 2. After solubilization of the microsomes in 1.5% sodium deoxycholate, an immunoprecipitate

  18. Microsomal UDP-glucuronyltransferase-catalyzed bilirubin diglucuronide formation in human liver

    Peters, W. H.; Jansen, P. L.

    1986-01-01

    Human liver microsomal bilirubin UDP-glucuronyltransferase catalyzes formation of bilirubin mono- and diglucuronide. KmUDPGA and Vmax of the enzyme are 0.6 mM and 1.69 nmol/mg protein X min. In vitro, bilirubin readily dissolves in the microsomal lipid phase. Taking this into account a Kmbilirubin

  19. Characterization of the Chicken Ovarian Cancer Model

    Rodriguez, Gustavo

    2002-01-01

    .... Unlike other ovarian cancer models, which require experimental induction of ovarian tumors, chickens develop ovarian adenocarcinoma spontaneously, with an incidence ranging from 13 to 40 percent...

  20. Characterization of the Chicken Ovarian Cancer Model

    Rodriguez, Gustavo C

    2004-01-01

    .... Unlike other ovarian cancer models, which require experimental induction of ovarian tumors, chickens develop ovarian adenocarcinoma spontaneously, with an incidence ranging from 13 to 40 percent...

  1. Characterization of the Chicken Ovarian Cancer Model

    Rodriguez, Gustavo C

    2005-01-01

    .... Unlike other ovarian cancer models, which require experimental induction of ovarian tumors, chickens develop ovarian adenocarcinoma spontaneously, with an incidence ranging from 13 to 40 percent...

  2. Characterization of the Chicken Ovarian Cancer Model

    Rodriguez, Gustavo

    2003-01-01

    .... Unlike other ovarian cancer models, which require experimental induction of ovarian tumors, chickens develop ovarian adenocarcinoma spontaneously, with an incidence ranging from 13 to 40 percent...

  3. Characterization of the Chicken Ovarian Cancer Model

    Rodriquez, Gustavo

    2001-01-01

    .... Unlike other ovarian cancer models, which require experimental induction of ovarian tumors, chickens develop ovarian adenocarcinoma spontaneously, with an incidence ranging from 13 to 40 percent...

  4. Differential metabolism of acrylonitrile to cyanide is responsible for the greater sensitivity of male vs female mice: role of CYP2E1 and epoxide hydrolases

    Chanas, Brian; Wang, Hongbing; Ghanayem, Burhan I.

    2003-01-01

    Acrylonitrile (AN) is a potent toxicant and a known rodent carcinogen. AN epoxidation to cyanoethylene oxide (CEO) via CYP2E1 and its subsequent metabolism via epoxide hydrolases (EH) to yield cyanide is thought to be responsible for the acute toxicity and mortality of AN. Recent reports showed that male mice are more sensitive than females to the acute toxicity/mortality of AN. The present work was undertaken to assess the metabolic and enzymatic basis for the greater sensitivity of male vs female mice to AN toxicity. Male and female wild-type and CYP2E1-null mice received AN at 0, 2.5, 10, 20, or 40 mg/kg by gavage. Cyanide concentrations were measured at 1 or 3 h after dosing. Current data demonstrated that cyanide levels in blood and tissues of AN-treated wild-type mice of both sexes were significantly greater than in vehicle-treated controls and increased in a dose-dependent manner. In contrast, cyanide levels in AN-treated CYP2E1-null mice were not statistically different from those measured in vehicle-treated controls. Furthermore, higher levels of cyanide were detected in male wild-type mice vs females in association with greater sensitivity of males to the acute toxicity/mortality of this chemical. Using Western blot analysis, negligible difference in CYP2E1 expression with higher levels of soluble and microsomal EH (sEH and mEH) was detected in the liver of male vs female mice. In kidneys, male mice exhibited higher expression of both renal CYP2E1 and sEH than did female mice. In conclusion, higher blood and tissue cyanide levels are responsible for the greater sensitivity of male vs female mice to AN. Further, higher expression of CYP2E1 and EH in male mice may contribute to greater formation of CEO and its subsequent metabolism to yield cyanide, respectively

  5. Resolution of limonene 1,2-epoxide diastereomers by mercury(II) ions

    Werf, M. van der; Jongejan, H.; Franssen, M.C.R.

    2001-01-01

    When HgCl2 was added to a diastereomeric mixture of cis- and trans-(4S)-limonene 1,2-epoxide, the Hg(II) ions stereoselectively complexed to the cis epoxide, enabling ring opening by water. The resulting mercuric salt could be demetalated by treatment with NaBH4, giving a mixture of diastereomeric

  6. Derivatization of castor oil based estolide esters: Preparation of epoxides and cyclic carbonates

    Estolides that are based on castor oil and oleic acid are versatile starting points for the production of industrial fluids with new properties. A variety of unsaturated estolides were derivatized by epoxidation with hydrogen peroxide. The epoxidized estolides were further modified using supercritic...

  7. Monolignol biosynthesis in microsomal preparations from lignifying stems of alfalfa (Medicago sativa L.).

    Guo, Dianjing; Chen, Fang; Dixon, Richard A

    2002-11-01

    Microsomal preparations from lignifying stems of alfalfa (Medicago sativa L.) contained coniferaldehyde 5-hydroxylase activity and immunodetectable caffeic acid 3-O-methyltransferase (COMT), and catalyzed the S-adenosyl L-methionine (SAM) dependent methylation of caffeic acid, caffeyl aldehyde and caffeyl alcohol. When supplied with NADPH and SAM, the microsomes converted caffeyl aldehyde to coniferaldehyde, 5-hydroxyconiferaldehyde, and traces of sinapaldehyde. Coniferaldehyde was a better precursor of sinapaldehyde than was 5-hydroxyconiferaldehyde. The alfalfa microsomes could not metabolize 4-coumaric acid, 4-coumaraldehyde, 4-coumaroyl CoA, or ferulic acid. No metabolism of monolignol precursors was observed in microsomal preparations from transgenic alfalfa down-regulated in COMT expression. In most microsomal preparations, the level of the metabolic conversions was independent of added recombinant COMT. Taken together, the data provide only limited support for the concept of metabolic channeling in the biosynthesis of S monolignols via coniferaldehyde.

  8. Effect of epoxide equivalent on microstructure of epoxy/rectorite nanocomposite studied by positrons

    Liu, L.M.; Fang, P.F.; Zhang, S.P.; Wang, S.J.

    2005-01-01

    The epoxy/rectorite nanocomposites with different epoxide equivalent ranging from 188 to 1110 were prepared and the effects of epoxide equivalent on microstructure of materials were studied by X-ray diffraction (XRD) and positron annihilation lifetime spectroscope (PALS). In nanocomposites, the formation of exfoliated structure was observed from XRD pattern at epoxide equivalent >263. The PALS measurements reveal that the fractional free volume in nanocomposites was strongly affected by epoxide equivalent, in particular, the free-volume concentration was dramatically decreased with the increasing epoxide equivalent from 188 to 263, and the S parameter indicates the rectorite structure change and the high sensitivity of positron annihilation to the entry of rectorite into epoxy. These results indicate that positron annihilation characteristics are useful for study the microstructure of epoxy/rectorite nanocomposites

  9. Epoxidation of polybutadiene rubber in non polar solvent

    Schneider, Luciane K. de A.; Jacobi, Marly A.M.

    2005-01-01

    The epoxidation of polybutadiene rubber in cyclohexane, at 50 deg C, by the method of performic acid generated in situ, at different reagent concentration was investigated. The epoxy degree was determined by 1 H-RMN, and because of the gelation and coagulation of modified rubber during the reaction, only a maximum of 30 mol % of epoxy degree could be achieved. The reaction followed a first order kinetic in relation to hydrogen peroxide and acid concentration showing a rate constant of 4,0 (± 0,5) x 10 -5 L.mol-1.seg -1 . (author)

  10. Ovarian volume throughout life

    Kelsey, Thomas W; Dodwell, Sarah K; Wilkinson, A Graham

    2013-01-01

    conception to 82 years of age. This model shows that 69% of the variation in ovarian volume is due to age alone. We have shown that in the average case ovarian volume rises from 0.7 mL (95% CI 0.4-1.1 mL) at 2 years of age to a peak of 7.7 mL (95% CI 6.5-9.2 mL) at 20 years of age with a subsequent decline...... to about 2.8 mL (95% CI 2.7-2.9 mL) at the menopause and smaller volumes thereafter. Our model allows us to generate normal values and ranges for ovarian volume throughout life. This is the first validated normative model of ovarian volume from conception to old age; it will be of use in the diagnosis......The measurement of ovarian volume has been shown to be a useful indirect indicator of the ovarian reserve in women of reproductive age, in the diagnosis and management of a number of disorders of puberty and adult reproductive function, and is under investigation as a screening tool for ovarian...

  11. 3,3′,4,4′,5-Pentachlorobiphenyl (PCB 126) Decreases Hepatic and Systemic Ratios of Epoxide to Diol Metabolites of Unsaturated Fatty Acids in Male Rats

    Wu, Xianai; Yang, Jun; Morisseau, Christophe; Robertson, Larry W.; Hammock, Bruce; Lehmler, Hans-Joachim

    2016-01-01

    Disruption of the homeostasis of oxygenated regulatory lipid mediators (oxylipins), potential markers of exposure to aryl hydrocarbon receptor (AhR) agonists, such as 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126), is associated with a range of diseases, including nonalcoholic fatty liver disease and nonalcoholic steatohepatitis. Here we test the hypothesis that PCB 126 exposure alters the levels of oxylipins in rats. Male Sprague-Dawley rats (5-weeks old) were treated over a 3-month period every 2 weeks with intraperitoneal injections of PCB 126 in corn oil (cumulative doses of 0, 19.8, 97.8, and 390 µg/kg b.w.; 6 injections total). PCB 126 treatment caused a reduction in growth rates at the highest dose investigated, a dose-dependent decrease in thymus weights, and a dose-dependent increase in liver weights. Liver PCB 126 levels increased in a dose-dependent manner, while levels in plasma were below or close to the detection limit. The ratios of several epoxides to diol metabolites formed via the cytochrome P450 (P450) monooxygenase/soluble epoxide hydrolase (sEH) pathway from polyunsaturated fatty acids displayed a dose-dependent decrease in the liver and plasma, whereas levels of oxylipins formed by other metabolic pathways were generally not altered by PCB 126 treatment. The effects of PCB 126 on epoxide-to-diol ratios were associated with an increased CYP1A activity in liver microsomes and an increased sEH activity in liver cytosol and peroxisomes. These results suggest that oxylipins are potential biomarkers of exposure to PCB 126 and that the P450/sEH pathway is a therapeutic target for PCB 126-mediated hepatotoxicity that warrants further attention. PMID:27208083

  12. Premature ovarian failure and ovarian autoimmunity

    J.A. Schoemaker (Joop); H.A. Drexhage (Hemmo); A. Hoek (Annemieke)

    1997-01-01

    textabstractPremature ovarian failure (POF) is defined as a syndrome characterized by menopause before the age of 40 yr. The patients suffer from anovulation and hypoestrogenism. Approximately 1% of women will experience menopause before the age of 40 yr. POF is a

  13. Metabolism of fatty acids in rat brain in microsomal membranes

    Aeberhard, E.E.; Gan-Elepano, M.; Mead, J.F.

    1980-01-01

    Using a technique in which substrate fatty acids are incorporated into microsomal membranes followd by comparison of their rates of desaturation or elongation with those of exogenous added fatty acids it has been found that the desaturation rate is more rapid for the membrane-bound substrate than for the added fatty acid. Moreover, the product of the membrane-bound substrate is incorporated into membrane phospholipid whereas the product of the exogenous substrate is found in di- and triacyl glycerols and in free fatty acids as well. These and other findings point to a normal sequence of reaction of membrane liqids with membrane-bound substrates involving transfer of fatty acid from phospholipid to the coupled enzyme systems without ready equilibration with the free fatty acid pool

  14. Coupled motions direct electrons along human microsomal P450 Chains.

    Christopher R Pudney

    2011-12-01

    Full Text Available Protein domain motion is often implicated in biological electron transfer, but the general significance of motion is not clear. Motion has been implicated in the transfer of electrons from human cytochrome P450 reductase (CPR to all microsomal cytochrome P450s (CYPs. Our hypothesis is that tight coupling of motion with enzyme chemistry can signal "ready and waiting" states for electron transfer from CPR to downstream CYPs and support vectorial electron transfer across complex redox chains. We developed a novel approach to study the time-dependence of dynamical change during catalysis that reports on the changing conformational states of CPR. FRET was linked to stopped-flow studies of electron transfer in CPR that contains donor-acceptor fluorophores on the enzyme surface. Open and closed states of CPR were correlated with key steps in the catalytic cycle which demonstrated how redox chemistry and NADPH binding drive successive opening and closing of the enzyme. Specifically, we provide evidence that reduction of the flavin moieties in CPR induces CPR opening, whereas ligand binding induces CPR closing. A dynamic reaction cycle was created in which CPR optimizes internal electron transfer between flavin cofactors by adopting closed states and signals "ready and waiting" conformations to partner CYP enzymes by adopting more open states. This complex, temporal control of enzyme motion is used to catalyze directional electron transfer from NADPH→FAD→FMN→heme, thereby facilitating all microsomal P450-catalysed reactions. Motions critical to the broader biological functions of CPR are tightly coupled to enzyme chemistry in the human NADPH-CPR-CYP redox chain. That redox chemistry alone is sufficient to drive functionally necessary, large-scale conformational change is remarkable. Rather than relying on stochastic conformational sampling, our study highlights a need for tight coupling of motion to enzyme chemistry to give vectorial electron

  15. Ovarian Cancer and Comorbidity

    Noer, Mette Calundann; Sperling, Cecilie Dyg; Ottesen, Bent

    2017-01-01

    OBJECTIVES: Comorbidity influences survival in ovarian cancer, but the causal relations between prognosis and comorbidity are not well characterized. The aim of this study was to investigate the associations between comorbidity, system delay, the choice of primary treatment, and survival in Danish...... ovarian cancer patients. METHODS: This population-based study was conducted on data from 5317 ovarian cancer patients registered in the Danish Gynecological Cancer Database. Comorbidity was classified according to the Charlson Comorbidity Index and the Ovarian Cancer Comorbidity Index. Pearson χ test...... and multivariate logistic regression analyses were used to investigate the association between comorbidity and primary outcome measures: primary treatment ("primary debulking surgery" vs "no primary surgery") and system delay (more vs less than required by the National Cancer Patient Pathways [NCPPs]). Cox...

  16. Ovarian Cancer FAQ

    ... vein thrombosis (DVT) , heart attack, and stroke. Current theories suggest that some types of ovarian cancer may ... Annual Meeting CME Overview CREOG Meetings Calendar Congressional Leadership Conference Advocacy Legislative Priorities GR & Outreach State Advocacy ...

  17. Management of ovarian cysts

    Knudsen, Ulla Breth; Tabor, Ann; Mosgaard, Berit Jul

    2004-01-01

    BACKGROUND: The treatment of an ovarian cyst relies on its nature, and accurate preoperative discrimination of benign and malignant cysts is therefore of crucial importance. This study was undertaken to review the literature concerning the preoperative diagnosis and treatment of ovarian cysts....... METHODS: Articles concerning ovarian cysts from a medline literature search during the period 1985-2003 were included in addition to articles found as references in the initial publications. RESULTS: Different methods for discriminating between benign and malignant ovarian cysts are discussed....... The diagnosis and the treatment are assessed in relation to age, menopausal status, pregnancy, and whether the cyst is presumed to be benign or malignant. In general, expectant management is the choice in premenopausal and pregnant women with non-suspicious cysts and normal levels of CA-125. In postmenopausal...

  18. Primary ovarian malignant melanoma

    Kostov Miloš

    2010-01-01

    Full Text Available Background. Primary ovarian malignant melanoma is extremely rare. It usually appears in the wall of a dermoid cyst or is associated with another teratomatous component. Metastatic primary malignant melanoma to ovary from a primary melanoma elsewhere is well known and has been often reported especially in autopsy studies. Case report. We presented a case of primary ovarian malignant melanoma in a 45- year old woman, with no evidence of extraovarian primary melanoma nor teratomatous component. The tumor was unilateral, macroscopically on section presented as solid mass, dark brown to black color. Microscopically, tumor cells showed positive immunohistochemical reaction for HMB-45, melan-A and S-100 protein, and negative immunoreactivity for estrogen and progesteron receptors. Conclusion. Differentiate metastatic melanoma from rare primary ovarian malignant melanoma, in some of cases may be a histopathological diagnostic problem. Histopathological diagnosis of primary ovarian malignant melanoma should be confirmed by immunohistochemical analyses and detailed clinical search for an occult primary tumor.

  19. Study of epoxidation and its influence on the poly dienes behavior

    Rocha, Tatiana L.A.C.; Schuster, Robert H.; Meier, Jens; Jacobi, Marly M.; Samios, Dimitrios

    2001-01-01

    The poly dienes epoxidation is a good method to modify the backbone chain, improving some of its properties. The epoxidation rate changes with the time and reaction temperature, epoxidize agent and polymer microstructure. There are two kinds of different kinetic behavior during the reaction of epoxidation, which are related to the epoxidation of trans 1,4 and cis 1,4 double bonds. An increase in the epoxidation content leads to an increase in the glass temperature (Tg) in all materials studied. Tailor-made linear poly dienes modified by epoxidation also show shifts of the flow region of the viscoelastic spectra to lower frequencies and significant changes in the dynamic mechanical storage and loss moduli. With higher side group density, the plateau modulus decreases due to lower entanglement density and the frequency limits of the rubber elastic region shift to lower values. Higher molecular weights shift the onset of the flow region towards lower frequencies extending the rubbery plateau. The predictions of refined tube models, which are derived directly from molecular considerations are in good correlation with the experimental data. (author)

  20. Physio-pharmacological Investigations About the Anti-inflammatory and Antinociceptive Efficacy of (+)-Limonene Epoxide.

    de Almeida, Antonia Amanda Cardoso; Silva, Renan Oliveira; Nicolau, Lucas Antonio Duarte; de Brito, Tarcísio Vieira; de Sousa, Damião Pergentino; Barbosa, André Luiz Dos Reis; de Freitas, Rivelilson Mendes; Lopes, Luciano da Silva; Medeiros, Jand-Venes Rolim; Ferreira, Paulo Michel Pinheiro

    2017-04-01

    D-limonene epoxidation generates (+)-limonene epoxide, an understudied compound in the pharmacologically point of view. Herein, we investigated the anti-inflammatory and antinociceptive potentialities of (+)-limonene epoxide and suggested a mechanism of action. The anti-inflammatory potential was analyzed using agents to induce paw edema, permeability, and myeloperoxidase (MPO) activity. Pro-inflammatory cytokines and cell migration of peritoneal cells were also assessed. Antinociceptive effects were evaluated by writhing test induced by acetic acid, formalin, and hot plate assays and contribution of opioid pathways. Pretreated animals with (+)-limonene epoxide showed reduced carrageenan-induced paw edema in all doses (25, 50, and 75 mg/kg) (P Limonene epoxide diminished abdominal contortions induced by acetic acid (78.9%) and paw licking times in both 1 (41.8%) and 2 (51.5%) phases and a pretreatment with naloxone (3 mg/kg) reverted the antinociceptive action in morphine- and (+)-limonene epoxide-treated groups (P limonene epoxide inhibited release/activity of inflammatory mediators, vascular permeability, migration of neutrophils and displayed systemic and peripheral analgesic-dependent effects of the opioid system.

  1. [Immunosuppressant effect of cyclophosphamide activated in vitro by liver microsomes from different strains of mice].

    Telegin, L Iu; Zhirnov, G F; Mazurov, A V; Pevnitskiĭ, L A

    1981-07-01

    The paper is concerned with activation of cyclophosphamide by mouse liver microsomes in vitro. Liver microsomes from BALB/c mice metabolize cyclophosphamide more effectively as compared with those from DBA/2 mice, which manifested by a more intense output of products having alkylating or immunodepressant properties. This seems likely to be a consequence of the increased P-450 cytochrome content in liver microsomes from BALB/c mice, as well as of its structural characteristics in the mouse. The relationship between the immunodepressant effect of cyclophosphamide in vivo and in vitro in mice of varied genotypes is discussed.

  2. Modification of radiation-induced oxidative damage in liposomal and microsomal membrane by eugenol

    Pandey, B.N. [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Lathika, K.M. [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Mishra, K.P. [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)]. E-mail: kpm@magnum.barc.ernet.in

    2006-03-15

    Radiation-induced membrane oxidative damage, and their modification by eugenol, a natural antioxidant, was investigated in liposomes and microsomes. Liposomes prepared with DPH showed decrease in fluorescence after {gamma}-irradiation, which was prevented significantly by eugenol and correlated with magnitude of oxidation of phospholipids. Presence of eugenol resulted in substantial inhibition in MDA formation in irradiated liposomes/microsomes, which was less effective when added after irradiation. Similarly, the increase in phospholipase C activity observed after irradiation in microsomes was inhibited in samples pre-treated with eugenol. Results suggest association of radio- oxidative membrane damage with alterations in signaling molecules, and eugenol significantly prevented these membrane damaging events.

  3. Methods of producing epoxides from alkenes using a two-component catalyst system

    Kung, Mayfair C.; Kung, Harold H.; Jiang, Jian

    2013-07-09

    Methods for the epoxidation of alkenes are provided. The methods include the steps of exposing the alkene to a two-component catalyst system in an aqueous solution in the presence of carbon monoxide and molecular oxygen under conditions in which the alkene is epoxidized. The two-component catalyst system comprises a first catalyst that generates peroxides or peroxy intermediates during oxidation of CO with molecular oxygen and a second catalyst that catalyzes the epoxidation of the alkene using the peroxides or peroxy intermediates. A catalyst system composed of particles of suspended gold and titanium silicalite is one example of a suitable two-component catalyst system.

  4. Technological aspects of vegetable oils epoxidation in the presence of ion exchange resins: a review

    Milchert Eugeniusz

    2016-09-01

    Full Text Available A review paper of the technology basics of vegetable oils epoxidation by means of peracetic or performic acid in the presence of acidic ion exchange resins has been presented. The influence of the following parameters: temperature, molar ratio of acetic acid and hydrogen peroxide to ethylenic unsaturation, catalyst loading, stirring intensity and the reaction time on a conversion of ethylenic unsaturation, the relative percentage conversion to oxirane and the iodine number was discussed. Optimal technological parameters, mechanism of epoxidation by carboxylic peracids and the possibilities of catalyst recycling have been also discussed. This review paper shows the application of epoxidized oils.

  5. Compositional profile of α / β-hydrolase fold proteins in mangrove soil metagenomes: prevalence of epoxide hydrolases and haloalkane dehalogenases in oil-contaminated sites.

    Jiménez, Diego Javier; Dini-Andreote, Francisco; Ottoni, Júlia Ronzella; de Oliveira, Valéria Maia; van Elsas, Jan Dirk; Andreote, Fernando Dini

    2015-05-01

    The occurrence of genes encoding biotechnologically relevant α/β-hydrolases in mangrove soil microbial communities was assessed using data obtained by whole-metagenome sequencing of four mangroves areas, denoted BrMgv01 to BrMgv04, in São Paulo, Brazil. The sequences (215 Mb in total) were filtered based on local amino acid alignments against the Lipase Engineering Database. In total, 5923 unassembled sequences were affiliated with 30 different α/β-hydrolase fold superfamilies. The most abundant predicted proteins encompassed cytosolic hydrolases (abH08; ∼ 23%), microsomal hydrolases (abH09; ∼ 12%) and Moraxella lipase-like proteins (abH04 and abH01; mangroves BrMgv01-02-03. This suggested selection and putative involvement in local degradation/detoxification of the pollutants. Seven sequences that were annotated as genes for putative epoxide hydrolases and five for putative haloalkane dehalogenases were found in a fosmid library generated from BrMgv02 DNA. The latter enzymes were predicted to belong to Actinobacteria, Deinococcus-Thermus, Planctomycetes and Proteobacteria. Our integrated approach thus identified 12 genes (complete and/or partial) that may encode hitherto undescribed enzymes. The low amino acid identity (< 60%) with already-described genes opens perspectives for both production in an expression host and genetic screening of metagenomes. © 2014 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  6. Compositional profile of α/β-hydrolase fold proteins in mangrove soil metagenomes: prevalence of epoxide hydrolases and haloalkane dehalogenases in oil-contaminated sites

    Jiménez, Diego Javier; Dini-Andreote, Francisco; Ottoni, Júlia Ronzella; de Oliveira, Valéria Maia; van Elsas, Jan Dirk; Andreote, Fernando Dini

    2015-01-01

    The occurrence of genes encoding biotechnologically relevant α/β-hydrolases in mangrove soil microbial communities was assessed using data obtained by whole-metagenome sequencing of four mangroves areas, denoted BrMgv01 to BrMgv04, in São Paulo, Brazil. The sequences (215 Mb in total) were filtered based on local amino acid alignments against the Lipase Engineering Database. In total, 5923 unassembled sequences were affiliated with 30 different α/β-hydrolase fold superfamilies. The most abundant predicted proteins encompassed cytosolic hydrolases (abH08; ∼ 23%), microsomal hydrolases (abH09; ∼ 12%) and Moraxella lipase-like proteins (abH04 and abH01; mangroves BrMgv01-02-03. This suggested selection and putative involvement in local degradation/detoxification of the pollutants. Seven sequences that were annotated as genes for putative epoxide hydrolases and five for putative haloalkane dehalogenases were found in a fosmid library generated from BrMgv02 DNA. The latter enzymes were predicted to belong to Actinobacteria, Deinococcus-Thermus, Planctomycetes and Proteobacteria. Our integrated approach thus identified 12 genes (complete and/or partial) that may encode hitherto undescribed enzymes. The low amino acid identity (< 60%) with already-described genes opens perspectives for both production in an expression host and genetic screening of metagenomes. PMID:25171437

  7. Premature ovarian failure and ovarian autoimmunity

    Schoemaker, Joop; Drexhage, Hemmo; Hoek, Annemieke

    1997-01-01

    textabstractPremature ovarian failure (POF) is defined as a syndrome characterized by menopause before the age of 40 yr. The patients suffer from anovulation and hypoestrogenism. Approximately 1% of women will experience menopause before the age of 40 yr. POF is a heterogeneous disorder with a multicausal pathogenesis involving chromosomal, genetic, enzymatic, infectious, and iatrogenic causes. There remains, however, a group of POF patients without a known etiology, the so-called "idiopathic...

  8. Multiple metastases from ovarian cancer

    Ovarian cancer affects women in the age group >60 years much ... ovarian cancer presenting with liver and thoracic vertebral metastases 4 months after ... manifested by parenchymal liver or lung ... categorised as stage Ic as per International.

  9. Hepatic microsomal phospholipids in rats exposed intratracheally to coal fly ash

    Srivastava, P.K.; Chauhan, S.S.; Misra, U.K.

    1986-01-01

    The effects of intratracheal administration of fly ash (50 mg/kg body weight, daily for 7 days) on hepatic microsomal phospholipid metabolism has been studied in rats using various phospholipid precursors, viz NaH 2 32 PO 4 , (methyl- 14 C)-choline, and (methyl- 14 C)-methionine. Fly ash administration significantly increased microsomal phosphatidylcholine (PC), and lysophosphatidylcholine (LPC). The incorporation of NaH 2 32 PO 4 into total liver phospholipids, PC and Phosphatidyl ethanolamine (PE) was significantly increased in fly ash-treated rats as compared to the control. Fly ash administration also increased the incorporation of (methyl- 14 C)-choline into microsomal PC. Incorporation of (methyl- 14 C)-methionine into microsomal PC was not affected. Fly ash administration decreased the per cent distribution of arachidonic acid in PC and PE and increased that of oleic acid in PC and of linoleic acid in PE. (orig.)

  10. Synthesis of Biolubricant Basestocks from Epoxidized Soybean Oil

    Rosa Turco

    2017-10-01

    Full Text Available This work deals with the preparation of biolubricant basestocks through the ring-opening reaction of epoxidized soybean oil (ESO by alcohols in presence of solid acid catalysts (SAC-13 resin. To this end, different experimental runs were carried out in a lab-scale reactor, analyzing the effect of the alcohol (methanol, ethanol, 2-propanol, 2-butanol, catalyst mass loading (from 1 to 10 wt % with respect to the oil mass and operating temperature (60–90 °C. The main focus of investigation was oxirane conversion. The study was complemented by FT-IR, 1H NMR and kinematic viscosity characterization of the different products of the ring-opening reaction. Experimental conversion data were fitted through a suitable kinetic model. Values of the best-fitting parameters in terms of rate constant, activation energy and catalyst reaction order were obtained, and were potentially useful for the design of an industrial process.

  11. Microwave absorption properties of barium titanate/epoxide resin composites

    Chen Xiaodong; Wang Guiqin; Duan Yuping; Liu Shunhua

    2007-01-01

    Nano-barium titanate (BT) was prepared by a sol-gel method. The prepared powders were characterized by x-ray powder diffraction and transmission electron microscopy. The complex relative dielectric permittivity (ε = ε' - jε-prime) and magnetic permeability (μ = μ' - jμ-prime) of the BT powders were measured in the frequency range 8 ∼ 18 GHz. The BT/epoxide resin (EP) composite with different volume contents was investigated. The effects of thickness on the BT/EP composite were studied. It was found that an optimum thickness and contents of the absorber can yield the maximum reflection loss which could be obtained over a broad frequency region in the X and Ku bands. Our results indicate that BT could be a promising microwave absorption material

  12. Enantioselective metabolism of hydroxychloroquine employing rats and mice hepatic microsomes

    Carmem Dickow Cardoso

    2009-12-01

    Full Text Available Hydroxychloroquine (HCQ is an important chiral drug used, mainly, in the treatment of rheumatoid arthritis, systemic lupus erythematosus and malaria, and whose pharmacokinetic and pharmacodynamic properties look to be stereoselective. Respecting the pharmacokinetic properties, some previous studies indicate that the stereoselectivity could express itself in the processes of metabolism, distribution and excretion and that the stereoselective metabolism looks to be a function of the studied species. So, the in vitro metabolism of HCQ was investigated using hepatic microsomes of rats and mice. The microsomal fraction of livers of Wistar rats and Balb-C mice was separated by ultracentrifugation and 500 μL were incubated for 180 minutes with 10 μL of racemic HCQ 1000 μg mL-1. Two stereospecific analytical methods, high performance liquid chromatography (HPLC and capillary electrophoresis (CE, were used to separate and quantify the formed metabolites. It was verified that the main formed metabolite is the (--(R-desethyl hydroxychloroquine for both animal species.A hidroxicloroquina (HCQ é um importante fármaco quiral usado, principalmente, no tratamento de artrite reumatóide, lupus eritematoso sistêmico e malária e cujas propriedades farmacocinéticas e farmacodinâmicas parecem ser estereosseletivas. Em relação às propriedades farmacocinéticas, alguns estudos prévios indicam que a estereosseletividade pode se expressar nos processos de metabolismo, distribuição e excreção e que o metabolismo estereosseletivo parece ser função da espécie estudada. Sendo assim, o metabolismo in vitro da HCQ foi investigado usando microssomas de fígado de ratos e de camundongos. A fração microssômica de fígados de ratos Wistar e de camundongos Balb-C foi isolada por ultracentrifugação e 500 μL foram incubados por 180 minutos com 10 μL de HCQ racêmica 1000 μg mL-1. Dois métodos analíticos estereoespecíficos, por cromatografia líquida de

  13. Age dependent in vitro metabolism of bifenthrin in rat and human hepatic microsomes.

    Nallani, Gopinath C; Chandrasekaran, Appavu; Kassahun, Kelem; Shen, Li; ElNaggar, Shaaban F; Liu, Zhiwei

    2018-01-01

    Bifenthrin, a pyrethroid insecticide, undergoes oxidative metabolism leading to the formation of 4'-hydroxy-bifenthrin (4'-OH-BIF) and hydrolysis leading to the formation of TFP acid in rat and human hepatic microsomes. In this study, age-dependent metabolism of bifenthrin in rats and humans were determined via the rates of formation of 4'-OH-BIF and TFP acid following incubation of bifenthrin in juvenile and adult rat (PND 15 and PND 90) and human (18years) liver microsomes. Furthermore, in vitro hepatic intrinsic clearance (CL int ) of bifenthrin was determined by substrate consumption method in a separate experiment. The mean V max (±SD) for the formation of 4'-OH-BIF in juvenile rat hepatic microsomes was 25.0±1.5pmol/min/mg which was significantly lower (pbifenthrin occurs primarily via oxidative pathway with relatively lesser contribution (~30%) from hydrolytic pathway in both rat and human liver microsomes. The CL int values for bifenthrin, determined by monitoring the consumption of substrate, in juvenile and adult rat liver microsomes fortified with NADPH were 42.0±7.2 and 166.7±20.5μl/min/mg, respectively, and the corresponding values for human liver microsomes were 76.0±4.0 and 21.3±1.2μl/min/mg, respectively. The data suggest a major species difference in the age dependent metabolism of bifenthrin. In human liver microsomes, bifenthrin is metabolized at a much higher rate in juveniles than in adults, while the opposite appears to be true in rat liver microsomes. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Stimulation of NADH-dependent microsomal DNA strand cleavage by rifamycin SV.

    Kukiełka, E; Cederbaum, A I

    1995-01-01

    Rifamycin SV is an antibiotic anti-bacterial agent used in the treatment of tuberculosis. This drug can autoxidize, especially in the presence of metals, and generate reactive oxygen species. A previous study indicated that rifamycin SV can increase NADH-dependent microsomal production of reactive oxygen species. The current study evaluated the ability of rifamycin SV to interact with iron and increase microsomal production of hydroxyl radical, as detected by conversion of supercoiled plasmid...

  15. Comparative Metabolism Study of Five Protoberberine Alkaloids in Liver Microsomes from Rat, Rhesus Monkey, and Human.

    Li, Yan; Zhou, Yanyan; Si, Nan; Han, Lingyu; Ren, Wei; Xin, Shaokun; Wang, Hongjie; Zuo, Ran; Wei, Xiaolu; Yang, Jian; Zhao, Haiyu; Bian, Baolin

    2017-11-01

    Protoberberine alkaloids including berberine, palmatine, jatrorrhizine, coptisine, and epiberberine are major components in many medicinal plants. They have been widely used for the treatment of cancer, inflammation, diabetes, depression, hypertension, and various infectious areas. However, the metabolism of five protoberberine alkaloids among different species has not been clarified previously. In order to elaborate on the in vitro metabolism of them, a comparative analysis of their metabolic profile in rat, rhesus monkey, and human liver microsomes was carried out using ultrahigh-performance liquid chromatography coupled with a high-resolution linear trap quadrupole-Orbitrap mass spectrometer (UHPLC-electrospray ionization-Orbitrap MS) for the first time. Each metabolite was identified and semiquantified by its accurate mass data and peak area. Fifteen metabolites were characterized based on accurate MS/MS spectra and the proposed MS/MS fragmentation pathways including demethylation, hydroxylation, and methyl reduction. Among them, the content of berberine metabolites in human liver microsomes was similar with those in rhesus monkey liver microsomes, whereas berberine in rat liver microsomes showed no demethylation metabolites and the content of metabolites showed significant differences with that in human liver microsomes. On the contrary, the metabolism of palmatine in rat liver microsomes resembled that in human liver microsomes. The content of jatrorrhizine metabolites presented obvious differences in all species. The HR-ESI-MS/MS fragmentation behavior of protoberberine alkaloids and their metabolic profile in rat, rhesus monkey, and human liver microsomes were investigated for the first time. The results demonstrated that the biotransformation characteristics of protoberberine alkaloids among different species had similarities as well differences that would be beneficial for us to better understand the pharmacological activities of protoberberine alkaloids

  16. Biobased composites from thermoplastic polyurethane elastomer and cross-linked acrylated-epoxidized soybean oil

    Soybean oil is an important sustainable material. Crosslinked acrylated epoxidized soybean oil (AESO) is brittle without flexibility and the incorporation of thermoplastic polyurethane improves its toughness for industrial applications. The hydrophilic functional groups from both oil and polyurethan...

  17. Dysregulation of soluble epoxide hydrolase and lipidomic profiles in anorexia nervosa

    Shih, P. B.; Yang, J.; Morisseau, C.; German, J. B.; Scott-Van Zeeland, A. A.; Armando, A. M.; Quehenberger, O.; Bergen, A. W.; Magistretti, Pierre J.; Berrettini, W.; Halmi, K. A.; Schork, N.; Hammock, B. D.; Kaye, W.

    2015-01-01

    Individuals with anorexia nervosa (AN) restrict eating and become emaciated. They tend to have an aversion to foods rich in fat. Because epoxide hydrolase 2 (EPHX2) was identified as a novel AN susceptibility gene, and because its protein product

  18. General regularities of olefin epoxidation by hydroperoxide catalyzed by V, W and Ti compounds

    Sapunov, V.N.; Sharykin, V.G.; Logvinov, A.S.; Litvintsev, I.Yu.; Lebedev, N.N.

    1983-01-01

    The kinetic analysis of cyclohexane epoxidation by ethylbenzene hydroperoxide when catalyzed by titanium- and tungsten cyclohexandiolates has shown that the reaction follows the main regularities of hydroperoxide epoxidation previously established for catalysis by molybdenum- and vanadiUm compounds. The catalyst activity varies depending on the metal nature and forms the following series: Mo>V>W>Ti, which agrees with their π-acceptor capacity. During the cyclohexane epoxidation on all catalysts the hydroperoxide activities vary according to the following series: ethylbenzene hydroperoxide>cumene>tertiarybutyl>tertiaryamyl. Correlation relationships between the olefine structure, characterized by th constants, and the reactivity of olefines are foUnd. The reaction sensitivity during catalysis by WV, and Ti cyclohexandiolates is -1.2, -1.0- and -1.3, respectively. The mechanism of hydroperoxide epoxidation of olefine is discussed

  19. Purification and characterisation of a novel enantioselective epoxide hydrolase from Aspergillus niger M200

    Kotík, Michael; Kyslík, Pavel

    2006-01-01

    Roč. 1760, - (2006), s. 245-252 ISSN 0006-3002 Institutional research plan: CEZ:AV0Z50200510 Keywords : epoxide hydrolase * enantioselectivity * aspergillus niger Subject RIV: EE - Microbiology, Virology

  20. High-temperature epoxidation of soybean oil in flow : speeding up elemental reactions wanted and unwanted

    Cortese, B.; Croon, de M.H.J.M.; Hessel, V.

    2012-01-01

    The soybean oil epoxidation reaction is investigated theoretically through kinetic modeling of temperature effects enabled through flow processing under superheated conditions. Different from previous studies on such processing, here a complex reaction network superimposed by multiphase transport is

  1. Photoeffects of near ultraviolet light upon a polycyclic aromatic hydrocarbon exposed to mouse skin microsomes

    Peirano, W.B.

    1991-01-01

    Near ultraviolet (UV) light has been reported to both enhance and inhibit the tumor incidence in mice dermally exposed to benzo(a)pyrene (BaP) or polycyclic aromatic hydrocarbon (PAH) mixtures. Near UV light interacts with PAHs producing a variety of oxygenated products such as phenols, endoperoxides and quinones. However, little is known about BaP products formed from near UV irradiation of BaP-exposed mouse skin. Therefore, 14 C-BaP was incubated with 3-methylcholanthrene (3-MC) induced C 3 H/HeJ and DBA/2J mouse skin microsomes with or without a 365 nm light source. The results indicated that the concurrent 365 nm light irradiation of induced mouse skin microsomes and BaP greatly enhanced the total conversion of BaP to its products, approximately 3-fold for the C 3 H/HeJ and approximately 7-fold for the DBA/2J mouse microsomes, compared to the induced mouse skin microsomes and BaP alone. HPLC analyses of organic extracts indicated a more than additive enhancement of the formation of most of the individual cochromatographed BaP metabolites due to the combined interaction of 365 nm light with BaP and skin microsomes. Similar interactions were observed using benz(a)anthracene (BaA) in this system. These data show that near UV light alters the metabolic profile of PAHs produced by mouse skin microsomes

  2. Development of cationically initiated UV curable coating systems based on cyclo-aliphatic diepoxide, ENR, epoxidized poly-butadiene and epoxidized soybean oil

    Kumar, R.N.; Quah, S.H.; Kong, K.W.; Rozman, H.D.; Tin, W.C.

    1999-01-01

    Epoxidized Natural Rubber (ENR) had been earlier found to impart toughness to otherwise brittle epoxy resin. Since the high viscosity of solutions of ENR in reactive solvent glycidyl methacrylate,imposed a limitation to the incorporation of higher percentages of the elastomer to the epoxy systems, experiments were initiated to employ the liquid elastomer, namely, epoxidized polybutadiene In the formulations. 'Mixture Design', a statistical experimental design, was adopted to study the effect of compositional and process variables on the curing of surface coatings formulated from the above system by UV radiation initiated by cationic photo-initiators. This paper also reports the results of the experiments carded out with epoxidized soybean oil Employed as a flexibilizer in the cycloaliphatic epoxy-ENR system

  3. MWCNTs-Reinforced Epoxidized Linseed Oil Plasticized Polylactic Acid Nanocomposite and Its Electroactive Shape Memory Behaviour

    Alam, Javed; Alam, Manawwer; Raja, Mohan; Abduljaleel, Zainularifeen; Dass, Lawrence

    2014-01-01

    A novel electroactive shape memory polymer nanocomposite of epoxidized linseed oil plasticized polylactic acid and multi-walled carbon nanotubes (MWCNTs) was prepared by a combination of solution blending, solvent cast technique, and hydraulic hot press moulding. In this study, polylactic acid (PLA) was first plasticized by epoxidized linseed oil (ELO) in order to overcome the major limitations of PLA, such as high brittleness, low toughness, and low tensile elongation. Then, MWCNTs were inc...

  4. Hydroxyl-substituted ladder polyethers via selective tandem epoxidation/cyclization sequence.

    Czabaniuk, Lara C; Jamison, Timothy F

    2015-02-20

    A new and highly selective method for the synthesis of hydroxyl-substituted tetrahydropyrans is described. This method utilizes titanium(IV) isopropoxide and diethyl tartrate to perform a diastereoselective epoxidation followed by in situ epoxide activation and highly selective endo-cyclization to form the desired tetrahydropyran ring. The HIJ ring fragment of the marine ladder polyether yessotoxin was synthesized using this two-stage tactic that proceeds with high efficiency and excellent regioselectivity.

  5. Selective epoxidation of allylic alcohols with a titania-silica aerogel

    Dusi, M.; Mallat, T.; Baiker, A. [Lab. of Technical Chemistry, Swiss Federal Inst. of Technology, ETH-Zentrum, Zuerich (Switzerland)

    1998-12-31

    An amorphous mesoporous titania-silica aerogel (20 wt%TiO{sub 2} - 80 wt% SiO{sub 2}) and tert.-butylhydroperoxide (TBHP) have been used for the epoxidation of various allylic alcohols. Allylic alcohols possessing an internal double bond were more reactive than those with a terminal C=C bond. Epoxide selectivities could be improved by addition of (basic) zeolite 4 A and NaHCO{sub 3} to the reaction mixture. (orig.)

  6. A Dynamic Supramolecular System Exhibiting Substrate Selectivity in the Catalytic Epoxidation of Olefins

    Jonsson, Stefan; Odille, Fabrice G. J.; Norrby, Per-Ola

    2005-01-01

    A dynamic supramolecular system involving hydrogen bonding between a Mn(III) salen catalyst and a Zn(II) porphyrin receptor exhibits selectivity for pyridine appended cis-beta-substituted styrene derivatives over phenyl appended derivatives in a catalytic epoxidation reaction.......A dynamic supramolecular system involving hydrogen bonding between a Mn(III) salen catalyst and a Zn(II) porphyrin receptor exhibits selectivity for pyridine appended cis-beta-substituted styrene derivatives over phenyl appended derivatives in a catalytic epoxidation reaction....

  7. Ovarian Stem Cell Nests in Reproduction and Ovarian Aging.

    Ye, Haifeng; Zheng, Tuochen; Li, Wei; Li, Xiaoyan; Fu, Xinxin; Huang, Yaoqi; Hu, Chuan; Li, Jia; Huang, Jian; Liu, Zhengyv; Zheng, Liping; Zheng, Yuehui

    2017-01-01

    The fixed primordial follicles pool theory, which monopolized reproductive medicine for more than one hundred years, has been broken by the discovery, successful isolation and establishment of ovarian stem cells. It has brought more hope than ever of increasing the size of primordial follicle pool, improving ovarian function and delaying ovarian consenescence. Traditional view holds that stem cell aging contributes to the senility of body and organs. However, in the process of ovarian aging, the main factor leading to the decline of the reproductive function is the aging and degradation of ovarian stem cell nests, rather than the senescence of ovarian germ cells themselves. Recent studies have found that the immune system and circulatory system are involved in the formation of ovarian germline stem cell niches, as well as regulating the proliferation and differentiation of ovarian germline stem cells through cellular and hormonal signals. Therefore, we can improve ovarian function and delay ovarian aging by improving the immune system and circulatory system, which will provide an updated program for the treatment of premature ovarian failure (POF) and infertility. © 2017 The Author(s). Published by S. Karger AG, Basel.

  8. Ovarian tubercular abscess mimicking ovarian carcinoma: A rare case report

    Abinash Agarwala

    2015-01-01

    Full Text Available Although genito-urinary tuberculosis is common, reports of isolated ovarian tubercular abscess are rare. Ovarian tubercular abscess may mimics that of an ovarian tumor, leading to diagnostic difficulties. We reported a case report of 35 years woman presented with chronic pain abdomen, weight loss, low-grade fever and a right ovarian mass on ultrasound, with a significantly elevated CA-125 level. On clinical and radiological evidence, diagnosis of ovarian carcinoma was made, and laparotomy was performed with resection of the ovary. Postoperative specimen sent for histological examination that revealed classic epithelioid granuloma and acid-fast bacilli were present in Ziehl-Neelsen stain. Patient was put on antitubercular regimen from our Dots center. She is improving clinical after taking antitubercular drug and is on regular follow up at our chest outpatient department. Ovarian tubercular abscess is common in young women living in endemic zones, but case report of isolated tubercular abscess is rarely reported. CA-125 can be raised in both ovarian tubercular abscess and ovarian carcinoma, and only imaging is not always conclusive. Laparotomy followed by tissue diagnosis can be helpful in this situation. As the prognosis and treatment outcome of ovarian tubercular abscess and ovarian carcinoma is different, proper diagnosis by laparotomy should be done. Early diagnosis of ovarian tubercular abscess is vital as untreated disease can lead to infertility.

  9. Ultrasound-assisted chemoenzymatic epoxidation of soybean oil by using lipase as biocatalyst.

    Bhalerao, Machhindra S; Kulkarni, Vaishali M; Patwardhan, Anand V

    2018-01-01

    The present work reports the use of ultrasonic irradiation for enhancing lipase catalyzed epoxidation of soybean oil. Higher degree of unsaturated fatty acids, present in the soybean oil was converted to epoxidized soybean oil by using an immobilized lipase, Candida antarctica (Novozym 435). The effects of various parameters on the relative percentage conversion of the double bond to oxirane oxygen were investigated and the optimum conditions were established. The parameters studied were temperature, hydrogen peroxide to ethylenic unsaturation mole ratio, stirring speed, solvent ratio, catalyst loading, ultrasound frequency, ultrasound input power and duty cycle. The main objective of this work was to intensify chemoenzymatic epoxidation of the soybean oil by using ultrasound, to reduce the time required for epoxidation. Epoxidation of the soybean oil was achieved under mild reaction conditions by indirect ultrasonic irradiations (using ultrasonic bath). The relative percentage conversion to oxirane oxygen of 91.22% was achieved within 5h. The lipase was remarkably stable under optimized reaction conditions, later was recovered and reused six times to produce epoxidized soybean oil (ESO). Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Ovarian cancer surgery

    Seibaek, Lene; Blaakaer, Jan; Petersen, Lone Kjeld

    2013-01-01

    PURPOSE: The study objective was to survey general health and coping in women undergoing ovarian cancer surgery, and subsequently to develop and test a supportive care intervention. METHODS/MATERIALS: Women who underwent surgery on the suspicion of ovarian cancer participated in a follow...... standard levels. Concerning mental health, levels were below standard during the entire period, but did improve with time, also in women in whom the potential cancer diagnosis was refuted. The preoperative differences between these groups leveled out postoperatively in terms of physical health. At the end...

  11. Impact of Stereochemistry on Ligand Binding: X-ray Crystallographic Analysis of an Epoxide-Based HIV Protease Inhibitor.

    Benedetti, Fabio; Berti, Federico; Campaner, Pietro; Fanfoni, Lidia; Demitri, Nicola; Olajuyigbe, Folasade M; De March, Matteo; Geremia, Silvano

    2014-09-11

    A new pseudopeptide epoxide inhibitor, designed for irreversible binding to HIV protease (HIV-PR), has been synthesized and characterized in solution and in the solid state. However, the crystal structure of the complex obtained by inhibitor-enzyme cocrystallization revealed that a minor isomer, with inverted configuration of the epoxide carbons, has been selected by HIV-PR during crystallization. The structural characterization of the well-ordered pseudopeptide, inserted in the catalytic channel with its epoxide group intact, provides deeper insights into inhibitor binding and HIV-PR stereoselectivity, which aids development of future epoxide-based HIV inhibitors.

  12. Premature ovarian failure

    Pacheco, José

    2011-01-01

    Premature ovarian failure is characterized by secondary amenorrhea affecting a woman before the age of 40, leading to hypoestrogenism, infertility, and consequences of premature menopause, such as osteoporosis, cardiovascular disease, neurovegetative alterations, and others. Follicular exhaustion is due to either follicles shortage or oocytes accelerated destruction. Main causes are genetic, autoimmune and iatrogenic. Among genetic causes Xq and Xp deletions, translocations, numeric aberratio...

  13. Polycystic ovarian syndrome

    Nina Madnani; Kaleem Khan; Phulrenu Chauhan; Girish Parmar

    2013-01-01

    Polycystic ovarian syndrome (PCOS) is a "multispeciality" disorder suspected in patients with irregular menses and clinical signs of hyperandrogenism such as acne, seborrhoea, hirsutism, irregular menses, infertility, and alopecia. Recently, PCOS has been associated with the metabolic syndrome. Patients may develop obesity, insulin resistance, acanthosis nigricans, Type 2 diabetes, dyslipidemias, hypertension, non-alcoholic liver disease, and obstructive sleep apnoea. Good clinical examinatio...

  14. Xyloglucan galactosyl- and fucosyltransferase activity from pea epicotyl microsomes

    Faik, A.; Chileshe, C.; Sterling, J.; Maclachlan, G.

    1997-01-01

    Microsomal membranes from growing tissue of pea (Pisum sativum L.) epicotyls were incubated with the substrate UDP-[14C]galactose (Gal) with or without tamarind seed xyloglucan (XG) as a potential galactosyl acceptor. Added tamarind seed XG enhanced incorporation of [14C]Gal into high-molecular-weight products (eluted from columns of Sepharose CL-6B in the void volume) that were trichloroacetic acid-soluble but insoluble in 67% ethanol. These products were hydrolyzed by cellulase to fragments comparable in size to XG subunit oligosaccharides. XG-dependent galactosyltransferase activity could be solubilized, along with XG fucosyltransferase, by the detergent 3-[(3-cholamidopropyl)-dimethylammonio]-1 propanesulfonate. When this enzyme was incubated with tamarind (Tamarindus indica L.) seed XG or nasturtium (Tropaeolum majus L.) seed XG that had been partially degalactosylated with an XG-specific beta-galactosidase, the rates of Gal transfer increased and fucose transfer decreased compared with controls with native XG. The reaction products were hydrolyzed by cellulase to 14C fragments that were analyzed by gel-filtration and high-performance liquid chromatography fractionation with pulsed amperometric detection. The major components were XG subunits, namely one of the two possible monogalactosyl octasaccharides (-XXLG-) and digalactosyl nonasaccharide (-XLLG-), whether the predominant octasaccharide in the acceptor was XXLG (as in tamarind seed XG) or XLXG (as in nasturtium seed XG). It is concluded that the first xylosylglucose from the reducing end of the subunits was the Gal acceptor locus preferred by the solubilized pea transferase. These observations are incorporated into a model for the biosynthesis of cell wall XGs

  15. Ovarian chocolate cysts

    Sugimura, Kazuro; Ishida, Tetsuya; Takemori, Masayuki; Kitagaki, Hajime; Tanaka, Yutaka; Yamasaki, Katsuhito; Shimizu, Tadafumi; Kono, Michio.

    1988-01-01

    Accurate preoperative staging of ovarian chocolate cysts is very important because recent hormonal therapy has been effective in low stage patients. However, it has been difficult to assess the preoperative stage of ovarian chocolate cysts. We evaluated the diagnostic potential of MRI in preoperative staging of 15 overian chocolate cysts. It was well known that the older the ovarian chocolate cyst was the more iron content it had. We examined the iron contents effect on T1 and T2 relaxation times in surgically confirmed chocolate cysts (stage II: 3 cases, stage III: 3 cases and stage IV: 9 cases by AFS classification, 1985) employing the 0.15-T MR system and 200 MHz spectrometer. There was a positive linear relation between T1 of the lesion using the MR system (T1) and T1 of the resected contents using the spectrometer (sp-T1); r = 0.93. The same relation was revealed between T2 and sp-T2; r = 0.87. It was indicated that T1 and T2 using the MR system was accurate. There was a negative linear relation between T1 and the iron contents ( r = -0.81) but no relation between T2 and the iron contents. T1 was 412 ± 91 msec for stage II, 356 ± 126 msec for stage III and 208 ± 30 msec for stage IV. T1 for stage IV was shorter than that for stage II and III, statistically significant differences were noted (p < 0.05). Thus, T1 was useful in differentiating a fresh from an old ovarian chocolate cyst. We concluded that T1 relaxation time using the MR system was useful for the staging of an ovarian chocolate cyst without surgery. (author)

  16. Epoxide-mediated differential packaging of Cif and other virulence factors into outer membrane vesicles.

    Ballok, Alicia E; Filkins, Laura M; Bomberger, Jennifer M; Stanton, Bruce A; O'Toole, George A

    2014-10-01

    Pseudomonas aeruginosa produces outer membrane vesicles (OMVs) that contain a number of secreted bacterial proteins, including phospholipases, alkaline phosphatase, and the CFTR inhibitory factor (Cif). Previously, Cif, an epoxide hydrolase, was shown to be regulated at the transcriptional level by epoxides, which serve as ligands of the repressor, CifR. Here, we tested whether epoxides have an effect on Cif levels in OMVs. We showed that growth of P. aeruginosa in the presence of specific epoxides but not a hydrolysis product increased Cif packaging into OMVs in a CifR-independent fashion. The outer membrane protein, OprF, was also increased under these conditions, but alkaline phosphatase activity was not significantly altered. Additionally, we demonstrated that OMV shape and density were affected by epoxide treatment, with two distinct vesicle fractions present when cells were treated with epibromohydrin (EBH), a model epoxide. Vesicles isolated from the two density fractions exhibited different protein profiles in Western blotting and silver staining. We have shown that a variety of clinically or host-relevant treatments, including antibiotics, also alter the proteins packaged in OMVs. Proteomic analysis of purified OMVs followed by an analysis of transposon mutant OMVs yielded mutants with altered vesicle packaging. Finally, epithelial cell cytotoxicity was reduced in the vesicles formed in the presence of EBH, suggesting that this epoxide alters the function of the OMVs. Our data support a model whereby clinically or host-relevant signals mediate differential packaging of virulence factors in OMVs, which results in functional consequences for host-pathogen interactions. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  17. Nitrite-mediated hydrolysis of epoxides catalyzed by halohydrin dehalogenase from Agrobacterium radiobacter AD1 : A new tool for the kinetic resolution of epoxides

    Hasnaoui, Ghania; Lutje Spelberg, Jeffrey H.; de Vries, Erik; Tang, Lixia; Hauer, Bernhard; Janssen, Dick B.

    2005-01-01

    Halohydrin dehalogenase obtained from Agrobacterium radiobacter AD1, has been tested for the nitrite-mediated ring opening of epoxides. This reaction mainly leads to the formation of unstable hydroxynitrite ester intermediates, which can be further hydrolyzed to the corresponding diols. This

  18. Stimulation of NADH-dependent microsomal DNA strand cleavage by rifamycin SV.

    Kukiełka, E; Cederbaum, A I

    1995-04-15

    Rifamycin SV is an antibiotic anti-bacterial agent used in the treatment of tuberculosis. This drug can autoxidize, especially in the presence of metals, and generate reactive oxygen species. A previous study indicated that rifamycin SV can increase NADH-dependent microsomal production of reactive oxygen species. The current study evaluated the ability of rifamycin SV to interact with iron and increase microsomal production of hydroxyl radical, as detected by conversion of supercoiled plasmid DNA into the relaxed open circular state. The plasmid used was pBluescript II KS(-), and the forms of DNA were separated by agarose-gel electrophoresis. Incubation of rat liver microsomes with plasmid plus NADH plus ferric-ATP caused DNA strand cleavage. The addition of rifamycin SV produced a time- and concentration-dependent increase in DNA-strand cleavage. No stimulation by rifamycin SV occurred in the absence of microsomes, NADH or ferric-ATP. Stimulation occurred with other ferric complexes besides ferric-ATP, e.g. ferric-histidine, ferric-citrate, ferric-EDTA, and ferric-(NH4)2SO4. Rifamycin SV did not significantly increase the high rates of DNA strand cleavage found with NADPH as the microsomal reductant. The stimulation of NADH-dependent microsomal DNA strand cleavage was completely blocked by catalase, superoxide dismutase, GSH and a variety of hydroxyl-radical-scavenging agents, but not by anti-oxidants that prevent microsomal lipid peroxidation. Redox cycling agents, such as menadione and paraquat, in contrast with rifamycin SV, stimulated the NADPH-dependent reaction; menadione and rifamycin SV were superior to paraquat in stimulating the NADH-dependent reaction. These results indicate that rifamycin SV can, in the presence of an iron catalyst, increase microsomal production of reactive oxygen species which can cause DNA-strand cleavage. In contrast with other redox cycling agents, the stimulation by rifamycin SV is more pronounced with NADH than with NADPH as the

  19. Inhibition of rat liver microsomal lipid peroxidation by N-acyldehydroalanines: An in vitro comparative study

    Buc-Calderon, P.; Roberfroid, M. (Universite Catholique de Louvain, Brussels (Belgium))

    1989-09-01

    Captodative substituted olefins are radical scavengers which react with free radicals to form stabilized radical adducts. One of those compounds, N-(paramethoxyphenylacetyl)dehydroalanine (AD-5), may react and scavenge both superoxide anion (O-2) and alk-oxyl radicals (RO.), and in this way prevent the appearance of their mediated biological effects. Nitrofurantoin and tert-butyl hydroperoxide were used as model compounds to stimulate free radical production and their mediated lipid peroxidation in rat liver microsomes. In addition, lipid peroxidation was also initiated by exposure of rat liver microsomal suspensions to ionizing radiation (gamma rays). The microsomal lipid peroxidation induced by these chemicals and physical agents was inhibited by the addition of AD-5. These effects were dose-dependent in a millimolar range of concentration. In addition, AD-5 has no effect on microsomal electron transport, showing that NADPH-cytochrome P450 reductase activity was not modified. These data, together with the comparisons of the effects of AD-5 and some antioxidant molecules such as superoxide dismutase, uric acid, and mannitol, support the conclusion that inhibition of lipid peroxidation by AD-5 is the result of its free radical scavenger activity. In addition, the inhibitory effect of AD-5 on microsomal lipid peroxidation was dependent of the nature of the free radical species involved in the initiation of the process, suggesting that O-2 is scavenged more efficiently than RO.

  20. Soluble epoxide hydrolase inhibitory activity of anthraquinone components from Aloe.

    Sun, Ya Nan; Kim, Jang Hoon; Li, Wei; Jo, A Reum; Yan, Xi Tao; Yang, Seo Young; Kim, Young Ho

    2015-10-15

    Aloe is a short-stemmed succulent herb widely used in traditional medicine to treat various diseases and as raw material in cosmetics and heath foods. In this study, we isolated and identified two new anthraquinone derivatives, aloinoside C (6) and aloinoside D (7), together with six known compounds from an aqueous dissolved Aloe exudate. Their structures were identified by spectroscopic analysis. The inhibitory effects of the isolated compounds on soluble epoxide hydrolase (sEH) were evaluated. Compounds 1-8 inhibited sEH activity potently, with IC50 values ranging from 4.1±0.6 to 41.1±4.2 μM. A kinetic analysis of compounds 1-8 revealed that the inhibitory actions of compounds 1, 6 and 8 were non-competitive, whereas those of compounds 2-5 and 7 were the mixed-type. Molecular docking increases our understanding of receptor-ligand binding of all compounds. These results demonstrate that compounds 1-8 from Aloe are potential sEH inhibitors. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Interspecies differences in the enantioselectivity of epoxide hydrolases in Cryptococcus laurentii (Kufferath) C.E. Skinner and Cryptococcus podzolicus (Bab'jeva & Reshetova) Golubev

    Botes, AL

    2005-01-01

    Full Text Available Isolates representing Cryptococcus laurentii and Cryptococcus podzolicus, originating from soil of a heath land indigenous to South Africa, were screened for the presence of enantioselective epoxide hydrolases for 2, 2-disubstituted epoxides...

  2. In vitro metabolism of benzo[a]pyrene-7,8-dihydrodiol and dibenzo[def,p]chrysene-11,12 diol in rodent and human hepatic microsomes

    Smith, Jordan N.; Mehinagic, Denis; Nag, Subhasree; Crowell, Susan R.; Corley, Richard A.

    2017-03-01

    Polycyclic aromatic hydrocarbons (PAHs) are contaminants that are ubiquitously found in the environment, produced through combustion of organic matter or petrochemicals, and many of which are procarcinogens. The prototypic PAH, benzo[a]pyrene (B[a]P) and the highly carcinogenic dibenzo[def,p]chrysene (DBC) are metabolically activated by isoforms of the P450 enzyme superfamily producing benzo[a]pyrene-7,8-dihydrodiol (B[a]P diol), dibenzo[def,p]chrysene-11,12 diol (DBC diol). Each of these diols can be further metabolized by cytochrome P450 enzymes to highly reactive diol-epoxide metabolites that readily react with DNA or by phase II conjugation facilitating excretion. To complement prior in vitro metabolism studies with parent B[a]P and DBC, both phase I metabolism and phase II glucuronidation of B[a]P diol and DBC diol were measured in hepatic microsomes from female B6129SF1/J mice, male Sprague-Dawley rats, and female humans. Metabolic parameters, including intrinsic clearance and Michaelis-Menten kinetics were calculated from substrate depletion data. Mice and rats demonstrated similar B[a]P diol phase I metabolic rates. Compared to rodents, human phase I metabolism of B[a]P diol demonstrated lower overall metabolic capacity, lower intrinsic clearance at higher substrate concentrations (>0.14 µM), and higher intrinsic clearance at lower substrate concentrations (<0.07 µM). Rates of DBC diol metabolism did not saturate in mice or humans and were highest overall in mice. Higher affinity constants and lower capacities were observed for DBC diol glucuronidation compared to B[a]P diol glucuronidation; however, intrinsic clearance values for these compounds were consistent within each species. Kinetic parameters reported here will be used to extend physiologically based pharmacokinetic (PBPK) models to include the disposition of B[a]P and DBC metabolites in animal models and humans to support future human health risk assessments.

  3. Occurrence of neoxanthin and lutein epoxide cycle in parasitic Cuscuta species.

    Kruk, Jerzy; Szymańska, Renata

    2008-01-01

    In the present study, xanthophyll composition of eight parasitic Cuscuta species under different light conditions was investigated. Neoxanthin was not detected in four of the eight species examined, while in others it occurred at the level of several percent of total xanthophylls. In C. gronovii and C. lupuliformis it was additionally found that the neoxanthin content was considerably stimulated by strong light. In dark-adapted plants, lutein epoxide level amounted to 10-22% of total xanthophylls in only three species, the highest being for C. lupuliformis, while in others it was below 3%, indicating that the lutein epoxide cycle is limited to only certain Cuscuta species. The obtained data also indicate that the presence of the lutein epoxide cycle and of neoxanthin is independent and variable among the Cuscuta species. The xanthophyll cycle carotenoids violaxanthin, antheraxanthin and zeaxanthin were identified in all the examined species and occurred at the level found in other higher plants. The xanthophyll and lutein epoxide cycle pigments showed typical response to high light stress. The obtained results also suggest that the ability of higher plants to synthesize lutein epoxide probably does not depend on the substrate specificity of zeaxanthin epoxidase but on the availability of lutein for the enzyme.

  4. Kinetics of the Epoxidation of Geraniol and Model Systems by Dimethyldioxirane

    B. S. Crow

    2004-02-01

    Full Text Available The mono-epoxidation of geraniol by dimethyldioxirane was carried out invarious solvents. In all cases, the product ratios for the 2,3 and 6,7 mono-epoxides werein agreement with literature values. Kinetic studies were carried out at 23 oC in thefollowing dried solvent systems: acetone (k2 = 1.49 M-1s-1, carbon tetrachloride/acetone(9/1, k2=2.19 M-1s-1, and methanol/acetone (9/1, k2 = 17 M-1s-1. Individual k2 valueswere calculated for epoxidation of the 2,3 and 6,7 positions in geraniol. The non-conjugated diene system was modeled employing two simple independent alkenes:2-methyl-2-pentene and 3-methyl-2-buten-1-ol by determining the respective k2 valuesfor epoxidation in various solvents. The kinetic results for each independent alkeneshowed that the relative reactivity of the two epoxidation sites in geraniol as a function ofsolvent was not simply a summation of the independent alkene systems.

  5. Cycloadditions to Epoxides Catalyzed by GroupIII-V Transition-Metal Complexes

    D'Elia, Valerio

    2015-05-25

    Complexes of groupIII-V transition metals are gaining increasing importance as Lewis acid catalysts for the cycloaddition of dipolarophiles to epoxides. This review examines the latest reports, including homogeneous and heterogeneous applications. The pivotal step for the cycloaddition reactions is the ring opening of the epoxide following activation by the Lewis acid. Two modes of cleavage (C-C versus C-O) have been identified depending primarily on the substitution pattern of the epoxide, with lesser influence observed from the Lewis acid employed. The widely studied cycloaddition of CO2 to epoxides to afford cyclic carbonates (C-O bond cleavage) has been scrutinized in terms of catalytic efficiency and reaction mechanism, showing that unsophisticated complexes of groupIII-V transition metals are excellent molecular catalysts. These metals have been incorporated, as well, in highly performing, recyclable heterogeneous catalysts. Cycloadditions to epoxides with other dipolarophiles (alkynes, imines, indoles) have been conducted with scandium triflate with remarkable performances (C-C bond cleavage). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Cycloadditions to Epoxides Catalyzed by GroupIII-V Transition-Metal Complexes

    D'Elia, Valerio; Pelletier, Jeremie; Basset, Jean-Marie

    2015-01-01

    Complexes of groupIII-V transition metals are gaining increasing importance as Lewis acid catalysts for the cycloaddition of dipolarophiles to epoxides. This review examines the latest reports, including homogeneous and heterogeneous applications. The pivotal step for the cycloaddition reactions is the ring opening of the epoxide following activation by the Lewis acid. Two modes of cleavage (C-C versus C-O) have been identified depending primarily on the substitution pattern of the epoxide, with lesser influence observed from the Lewis acid employed. The widely studied cycloaddition of CO2 to epoxides to afford cyclic carbonates (C-O bond cleavage) has been scrutinized in terms of catalytic efficiency and reaction mechanism, showing that unsophisticated complexes of groupIII-V transition metals are excellent molecular catalysts. These metals have been incorporated, as well, in highly performing, recyclable heterogeneous catalysts. Cycloadditions to epoxides with other dipolarophiles (alkynes, imines, indoles) have been conducted with scandium triflate with remarkable performances (C-C bond cleavage). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Anti-Leishmania and cytotoxic activities of perillaldehyde epoxide synthetic positional isomers.

    Keesen, Tatjana Souza Lima; da Silva, Larisse Virgolino; da Câmara Rocha, Juliana; Andrade, Luciana Nalone; Lima, Tamires Cardoso; de Sousa, Damião Pergentino

    2018-03-13

    Leishmaniasis belongs to a complex of zoonotic disease caused by protozoa of the genus Leishmania and is considered a major public health problem. Several essential oil chemical components have inhibitory effect against protozoa, including Leishmania donovani. Thus, the aim of this study was to evaluate for the first time the anti-Leishmania activity of two p-menthane monoterpene isomers (EPER-1: perillaldehyde 1,2-epoxide and EPER-2: perillaldehyde 8,9-epoxide) against L. donovani promastigotes as well as evaluating cytotoxic effect on mononuclear peripheral blood cells. Results of anti-Leishmania assay revealed that EPER-2 (IC 50  = 3.8 μg.mL -1 ) was 16-fold more potent than its isomer EPER-1 (IC 50  = 64.6 μg.mL -1 ). In contrast to PBMC cells, EPER-2 was not cytotoxic (IC 50  > 400 μg.mL -1 ) when compared to positive control. These data suggest that the disposition of epoxide group into the p-menthane skeleton affects the anti-Leishmania activity, being that the presence of the exocyclic epoxide group considerably increased potency. Thus, it was possible to observe that the location of the epoxide group into the p-menthane skeleton resulted in different potencies.

  8. Chemo-enzymatic epoxidation of olefins by carboxylic acid esters and hydrogen peroxide

    Ruesch gen. Klaas, M.; Warwel, S. [Inst. for Biochemistry and Technology of Lipids, H.P. Kaufmanm-Inst., Federal Centre for Cereal, Potato and Lipid Research, Muenster (Germany)

    1998-12-31

    Ethylen and, recently, butadiene can be epoxidized directly with oxygen and for the epoxidation of propylene, the use of heterogeneous transition metals and organic peroxides (Halcon-Process) is the major player. But, beside from those notable exceptions, all other epoxidations, including large ones like the epoxidation of plant oils as PVC-stabilizers (about 200.000 t/year), are carried out with peroxy acids. Because mcpba is far to expensive for most applications, short chain peracids like peracetic acid are used. Being much less stable than mcpba and thus risky handled in large amounts and high concentrations, these peroxy acids were preferably prepared in-situ. However, conventional in-situ formation of peracids has the serious drawback, that a strong acid is necessary to catalyze peroxy acid formation from the carboxylic acid and hydrogen peroxide. The presence of a strong acid in the reaction mixture often results in decreased selectivity because of the formation of undesired by-products by opening of the oxirane ring. Therefore, we propose a new method for epoxidation based on the in-situ preparation of percarboxylic acids from carboxylic acid esters and hydrogen peroxide catalyzed by a commercial, immobilized lipase. (orig.)

  9. Towards prevention of ovarian cancer.

    Ali, Aus Tariq

    2018-01-01

    Ovarian cancer is the leading cause of death of all gynaecological cancers. To date, there is no reliable, specific screening procedure for detecting ovarian cancer. The risk factors of ovarian cancer include modifiable and non-modifiable factors. The main goal of the ovarian cancer prevention program is to significantly reduce the risk of development of ovarian cancer and other cancers such as breast and/or peritoneal cancer. The application of non-surgical preventive approaches such as oral contraceptives, parity and breastfeeding has been shown to be highly protective against ovarian cancer development. Targeting inflammation has been also reported to be associated with a protective trend against ovarian cancer and can be achieved through either non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin or lifestyle modifications or both. Lifestyle modification that includes regular exercise, healthy diet supplemented with anti-oxidants and anti-inflammatory elements reduces the risk of the disease even further. Surgical protective approaches include; tubal ligation, hysterectomy and prophylactic bilateral salpingo-oophorectomy and the former is the most effective approach to protect against ovarian cancer. A better understanding of the risk factors of ovarian cancer and the current approaches to prevent it may increase the awareness and help to decrease the incidence of ovarian cancer, increase the five-year survival rate and decrease the mortality rate significantly in the general population especially among those at high risk for ovarian cancer. This review is an attempt to outline a potential program of ovarian cancer prevention and the potential challenges. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  10. Automation of metabolic stability studies in microsomes, cytosol and plasma using a 215 Gilson liquid handler.

    Linget, J M; du Vignaud, P

    1999-05-01

    A 215 Gilson liquid handler was used to automate enzymatic incubations using microsomes, cytosol and plasma. The design of automated protocols are described. They were based on the use of 96 deep well plates and on HPLC-based methods for assaying the substrate. The assessment of those protocols was made with comparison between manual and automated incubations, reliability and reproducibility of automated incubations in microsomes and cytosol. Examples of the use of those programs in metabolic studies in drug research, i.e. metabolic screening in microsomes and plasma were shown. Even rapid processes (with disappearance half lives as low as 1 min) can be analysed. This work demonstrates how stability studies can be automated to save time, render experiments involving human biological media less hazardous and may be improve inter-laboratory reproducibility.

  11. Cranberry juice suppressed the diclofenac metabolism by human liver microsomes, but not in healthy human subjects

    Ushijima, Kentarou; Tsuruoka, Shu-ichi; Tsuda, Hidetoshi; Hasegawa, Gohki; Obi, Yuri; Kaneda, Tae; Takahashi, Masaki; Maekawa, Tomohiro; Sasaki, Tomohiro; Koshimizu, Taka-aki; Fujimura, Akio

    2009-01-01

    AIM To investigate a potential interaction between cranberry juice and diclofenac, a substrate of CYP2C9. METHODS The inhibitory effect of cranberry juice on diclofenac metabolism was determined using human liver microsome assay. Subsequently, we performed a clinical trial in healthy human subjects to determine whether the repeated consumption of cranberry juice changed the diclofenac pharmacokinetics. RESULTS Cranberry juice significantly suppressed diclofenac metabolism by human liver microsomes. On the other hand, repeated consumption of cranberry juice did not influence the diclofenac pharmacokinetics in human subjects. CONCLUSIONS Cranberry juice inhibited diclofenac metabolism by human liver microsomes, but not in human subjects. Based on the present and previous findings, we think that although cranberry juice inhibits CYP2C9 activity in vitro, it does not change the pharmacokinetics of medications metabolized by CYP2C9 in clinical situations. PMID:19694738

  12. Influence of whole body irradiation on induction of the hepatic microsomal system metabolizing drugs

    Szyszko, A.; Bitny-Szlachto, S.

    1977-01-01

    Effects of whole body irradiation (600 R) on rat liver aminophenazone demethylase activities of the liver homogenate 10,000 X g supernatant and its microsomal fraction were compared. Either activities were found to be decreased by irradiation by some 35%. The phenobarbital treatment (3 x 100 mg/kg i.p.) has turned out to provide higher relative augmentation of the liver demethylase activity in irradiated than in unirradiated rats. The cytoplasmic activity was found to be augmented by phenobarbital treatment 2,21-fold in unirradiated, and 3,20-fold in irradiated rats, and the microsomal activity increased 3,28-fold and 3,77-fold, respectively. Microsomal levels of cytochrome P-450 were found to be not affected by irradiation. (author)

  13. Ovarian hormones and obesity.

    Leeners, Brigitte; Geary, Nori; Tobler, Philippe N; Asarian, Lori

    2017-05-01

    Obesity is caused by an imbalance between energy intake, i.e. eating and energy expenditure (EE). Severe obesity is more prevalent in women than men worldwide, and obesity pathophysiology and the resultant obesity-related disease risks differ in women and men. The underlying mechanisms are largely unknown. Pre-clinical and clinical research indicate that ovarian hormones may play a major role. We systematically reviewed the clinical and pre-clinical literature on the effects of ovarian hormones on the physiology of adipose tissue (AT) and the regulation of AT mass by energy intake and EE. Articles in English indexed in PubMed through January 2016 were searched using keywords related to: (i) reproductive hormones, (ii) weight regulation and (iii) central nervous system. We sought to identify emerging research foci with clinical translational potential rather than to provide a comprehensive review. We find that estrogens play a leading role in the causes and consequences of female obesity. With respect to adiposity, estrogens synergize with AT genes to increase gluteofemoral subcutaneous AT mass and decrease central AT mass in reproductive-age women, which leads to protective cardiometabolic effects. Loss of estrogens after menopause, independent of aging, increases total AT mass and decreases lean body mass, so that there is little net effect on body weight. Menopause also partially reverses women's protective AT distribution. These effects can be counteracted by estrogen treatment. With respect to eating, increasing estrogen levels progressively decrease eating during the follicular and peri-ovulatory phases of the menstrual cycle. Progestin levels are associated with eating during the luteal phase, but there does not appear to be a causal relationship. Progestins may increase binge eating and eating stimulated by negative emotional states during the luteal phase. Pre-clinical research indicates that one mechanism for the pre-ovulatory decrease in eating is a

  14. Lipid peroxidation in microsomes of murine bone marrow after low-dose γ-irradiation

    Schwenke, K.; Coslar, S.; Muehlensiepen, H.; Altman, K.I.; Feinendegen, L.E.

    1994-01-01

    The principal aim of the study was to investigate the effect of low-dose γ-irradiation on lipid peroxidation (LPO) in murine bone marrow. To this end, the degree of LPO in suspensions of microsomes of murine bone marrow cells (BMC) was determined in terms of malondialdehyde (MDA) formation after whole-body or in vitro exposure to various doses of γ-radiation. These effects were compared to some extent with similar effects in liver and spleen preparations. As to the effect of γ-irradiation on LPO in BMC, the response depends on the dose level and on whether whole-body or in vitro exposures are involved. Whole-body irradiation did not result in an increase in LPO in BMC microsomes, even at such high doses as 15 Gy, although hepatic microsomes showed a marked increase. In contrast, in vitro irradiation of BMC microsomes with 0.1, 10 and 50 Gy brought about an increase in LPO. This increase was already significant (P < 0.05) at 0.1 Gy following a post-irradiation incubation and substantial at 50 Gy, even without subsequent incubation. The results show that low doses of γ-irradiation are able to induce an elevation of LPO in murine BMC microsomes, but only after in vitro irradiation. In the case of whole-body irradiation cellular radical scavengers and other metabolic reactions may prevent a measurable increase in LPO. This is partly illustrated by the case of vitamin-E deficiency, where a substantial increase in LPO in BMC microsomes is observed even without γ-irradiation in comparison with euvitaminotic mice because normally occurring radicals are not scavenged sufficiently. (orig.)

  15. Inhibition of rat microsomal lipid peroxidation by the oral administration of D002

    Menéndez R.

    2000-01-01

    Full Text Available The effect of D002, a defined mixture of higher primary alcohols purified from bee wax, on in vivo and in vitro lipid peroxidation was studied. The extent of lipid peroxidation was measured on the basis of the levels of thiobarbituric acid reactive substances (TBARS. When D002 (5-100 mg/kg body weight was administered orally to rats for two weeks, a partial inhibition of the in vitro enzymatic and non-enzymatic lipid peroxidation was observed in liver and brain microsomes. Maximal protection (46% occurred at a dose of 25 mg/kg. D002 behaved differently depending on both the presence of NADPH and the integrity of liver microsomes, which suggests that under conditions where microsomal metabolism was favored the protective effect of D002 was increased. D002 (25 mg/kg also completely inhibited carbon tetrachloride- and toluene-induced in vivo lipid peroxidation in liver and brain. Also, D002 significantly lowered in a dose-dependent manner the basal level of TBARS in liver (19-40% and brain (28-44% microsomes. We conclude that the oral administration of D002 (5, 25 and 100 mg/kg for two weeks protected rat liver and brain microsomes against microsomal lipid peroxidation in vitro and in vivo. Thus, D002 could be useful as a dietary natural antioxidant supplement. More studies are required before these data can be extrapolated to the recommendation for the use of D002 as a dietary antioxidant supplement for humans.

  16. Changes induced by gamma radiation in microsomal membranes of storage of garlic

    Perez, M.B.; Croci, C.A.; Aveldano, M.I.

    2003-01-01

    This study evaluates the effects of the radio inhibition process on garlic bulbs in terms of phase properties of microsomal membranes and their lipid and fatty acid composition. Garlic bulbs were irradiated with an average dose of 60 Gy of 60 Co gamma rays 30-40 days after harvest. The treatment was carried out in the facilities of the National Atomic Energy Commission (CNEA). Rough and smooth microsomal membranes were isolated by ultracentrifugation from tissues of irradiated and non-irradiated storage leaves. Wide angle X-ray diffractograms of both fractions were recorded along 270 days of storage. Lipids were separated by thin layer chromatography. The fatty acid composition of major lipid fractions was studied by gas-liquid chromatography. The diffractograms featured peaks at Bragg spacing of 4.15 Armstrong and 3.75 Armstrong, revealing the presence of a gel (crystalline) phase, while the characteristic peak of the liquid-crystalline phase (4.6 Armstrong) was not observed in both sorts of membranes. Irradiation was found to bring about modifications in the intensity of 4.15 Armstrong and 3.75 Armstrong peaks from smooth microsomal membranes, but not in the behaviour along the studied period. Data from the rough microsomal fraction were erratic. Parallel to these changes, radiation induced significant modifications in the level of smooth microsomal membrane triacylglycerols in relation to phospholipids and their fatty acids. These findings indicate that the storage leaf tissues of garlic are radiosensitive both in terms of physical and chemical properties of their microsomal membranes. From the practical point of view, these results could be the basis for the development of techniques to be applied to storage garlic to evaluate if it was irradiated. (author)

  17. Isotope labelling study of CO oxidation-assisted epoxidation of propene. Implications for oxygen activation on Au catalysts.

    Jiang, Jian; Oxford, Sean M; Fu, Baosong; Kung, Mayfair C; Kung, Harold H; Ma, Jiantai

    2010-06-07

    (18)O isotope labelling studies of the CO oxidation-assisted epoxidation of propene, catalyzed by a mixture of Au/TiO(2) and TS-1, using a methanol-H(2)O solvent showed the O in the epoxide was exclusively from O(2) and not H(2)O or methanol.

  18. Tubo-ovarian actinomycosis.

    Shroff C

    1981-01-01

    Full Text Available Actinomycotic infection of the female genital tract is rare. Actinomycosis is a chronic suppurative granulomatous infection that is characterized by formation of abscesses, multiple draining sinuses and appearance of tangled mycelial masses or granules in the discharges and tissue sections. 2 cases of tubo-ovarian actinomycosis are reported. The 1st case presented clinical with gastrointestinal symptoms and a ventral scar hernia following an operation for a non-healing abdominal wound 6 months earlier. The 2nd case sought medical attention for backache and leucorrhea of 4 years′ duration. Exploratory laparotomy in the 1st case revealed tubo-ovarian masses; the vermiform appendix was not traceable. The uterine cavity in the 2nd case harbored a wooden stick. Direct extension from established ileocacal actinomycosis was believed to involve the female genital adnexae in the past. Association of tubo-ovarian actinomycosis with the presence of a foreign body in the female genital tract has been reported sporadically in the literature, yet an increase in the incidence may be expected because of the frequent use of intrauterine contraceptive devices in recent times. It is suggested that in women presenting clinically with vague abdominal symptoms, backache and discharge, actinomycosis should be considered and ruled out with the help of cytologic and proper microbial culture methods. Once the diagnosis is established, the infection can be treated with good results with penicillin.

  19. Intravital Microscopy in Evaluating Patients With Primary Peritoneal, Fallopian Tube, or Stage IA-IV Ovarian Cancer

    2018-06-04

    Fallopian Tube Carcinoma; Primary Peritoneal Carcinoma; Stage I Ovarian Cancer; Stage IA Ovarian Cancer; Stage IB Ovarian Cancer; Stage IC Ovarian Cancer; Stage II Ovarian Cancer; Stage IIA Ovarian Cancer; Stage IIB Ovarian Cancer; Stage IIC Ovarian Cancer; Stage III Ovarian Cancer; Stage IIIA Ovarian Cancer; Stage IIIB Ovarian Cancer; Stage IIIC Ovarian Cancer; Stage IV Ovarian Cancer

  20. Hepatic microsomal metabolism of BDE-47 and BDE-99 by lesser snow geese and Japanese quail.

    Krieger, Lisa K; Szeitz, András; Bandiera, Stelvio M

    2017-09-01

    In the present study, we investigated the oxidative biotransformation of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) and 2,2',4,4',5-pentabromodiphenyl ether (BDE-99) by liver microsomes from wild lesser snow geese (Chen caerulescens caerulescens) and domesticated Japanese quail (Coturnix japonica). Formation of hydroxy-metabolites was analyzed using an ultra-high performance liquid chromatography-tandem mass spectrometry-based method. Incubation of BDE-47 with avian liver microsomes produced sixteen hydroxy-metabolites, eight of which were identified using authentic standards. The major metabolites formed by liver microsomes from individual lesser snow geese were 4-hydroxy-2,2',3,4'-tetrabromodiphenyl ether (4-OH-BDE-42), 3-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (3-OH-BDE-47), and 4'-hydroxy-2,2',4,5'-tetrabromodiphenyl ether (4'-OH-BDE-49). By comparison, 4-OH-BDE-42 and 4'-OH-BDE-49, but not 3-OH-BDE-47, were major metabolites of Japanese quail liver microsomes. Unidentified metabolites included monohydroxy- and dihydroxy-tetrabromodiphenyl ethers. Incubation of BDE-99 with avian liver microsomes produced seventeen hydroxy-metabolites, twelve of which were identified using authentic standards. The major metabolites formed by lesser snow goose liver microsomes were 2,4,5-tribromophenol, 3-OH-BDE-47, 4'-OH-BDE-49, 4-hydroxy-2,2',3,4',5-pentabromodiphenyl ether (4-OH-BDE-90), and 5'-hydroxy-2,2',4,4',5-pentabromodiphenyl ether (5'-OH-BDE-99). By comparison, the major metabolites produced by liver microsomes from Japanese quail included 6-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (6-OH-BDE-47) and 2-hydroxy-2',3,4,4',5-pentabromodiphenyl ether (2-OH-BDE-123), but not 3-OH-BDE-47. Unidentified metabolites consisted of monohydroxy-pentabromodiphenyl ethers, monohydroxy-tetrabromodiphenyl ethers and dihydroxy-tetrabromodiphenyl ethers. Another difference between the two species was that formation rates of BDE-47 and BDE-99 metabolites were greater with liver

  1. Preparation of Epoxidized Palm Olein as Renewable Material by Using Peroxy Acids

    Darfizzi Derawi; Jumat Salimon; Waled Abdo Ahmed

    2014-01-01

    Epoxidized palm olein (EPO o ) was prepared through generated in situ of performic acid (HCOOOH), and peracetic acid (CH 3 COOOH) as epoxidation agent with the presence of sulphuric acid (H 2 SO 4 ) 3 % v/ wt as catalyst. Formic acid (HCOOH) or acetic acid (CH 3 COOH) as oxygen carrier and hydrogen peroxide (H 2 O 2 ) as oxygen donor in the reaction system. Highly conversion (95.5 %) of oxirane ring was obtained by using performic acid as epoxidation agent at 150 minutes of reaction time. The reaction yield was 90 % by weight. EPO o has showed good physicochemical properties as renewable material for industrial applications. Carbon ( 13 C-NMR) and proton ( 1 H-NMR) spectra showed the present of epoxy profile at 54 ppm and 2.9 ppm. Epoxy group was detected on 844 cm -1 by fourier transformation infra-red (FTIR) spectra. (author)

  2. Lead, selenium and nickel concentrations in epithelial ovarian cancer, borderline ovarian tumor and healthy ovarian tissues.

    Canaz, Emel; Kilinc, Metin; Sayar, Hamide; Kiran, Gurkan; Ozyurek, Eser

    2017-09-01

    Wide variation exists in ovarian cancer incidence rates suggesting the importance of environmental factors. Due to increasing environmental pollution, trace elements and heavy metals have drawn attention in studies defining the etiology of cancer, but scant data is available for ovarian cancer. Our aim was to compare the tissue concentrations of lead, selenium and nickel in epithelial ovarian cancer, borderline tumor and healthy ovarian tissues. The levels of lead, selenium and nickel were estimated using atomic absorption spectrophotometry in formalin-fixed paraffin-embedded tissue samples. Tests were carried out in 20 malignant epithelial ovarian cancer, 15 epithelial borderline tumor and 20 non-neoplastic healthy ovaries. Two samples were collected for borderline tumors, one from papillary projection and one from the smooth surface of cyst wall. Pb and Ni concentrations were found to be higher both in malignant and borderline tissues than those in healthy ovaries. Concentrations of Pb and Ni in malignant tissues, borderline papillary projections and capsular tissue samples were not different. Comparison of Se concentrations of malignant, borderline and healthy ovarian tissues did not reveal statistical difference. Studied metal levels were not found to be different in either papillary projection or in cyst wall of the borderline tumors. This study revealed the accumulation of lead and nickel in ovarian tissue is associated with borderline and malignant proliferation of the surface epithelium. Accumulation of these metals in epithelial ovarian cancer and borderline ovarian tumor has not been demonstrated before. Copyright © 2017 Elsevier GmbH. All rights reserved.

  3. Evaluation of fish models of soluble epoxide hydrolase inhibition.

    Newman, J W; Denton, D L; Morisseau, C; Koger, C S; Wheelock, C E; Hinton, D E; Hammock, B D

    2001-01-01

    Substituted ureas and carbamates are mechanistic inhibitors of the soluble epoxide hydrolase (sEH). We screened a set of chemicals containing these functionalities in larval fathead minnow (Pimphales promelas) and embryo/larval golden medaka (Oryzias latipes) models to evaluate the utility of these systems for investigating sEH inhibition in vivo. Both fathead minnow and medaka sEHs were functionally similar to the tested mammalian orthologs (murine and human) with respect to substrate hydrolysis and inhibitor susceptibility. Low lethality was observed in either larval or embryonic fish exposed to diuron [N-(3,4-dichlorophenyl), N'-dimethyl urea], desmethyl diuron [N-(3,4-dichlorophenyl), N'-methyl urea], or siduron [N-(1-methylcyclohexyl), N'-phenyl urea]. Dose-dependent inhibition of sEH was a sublethal effect of substituted urea exposure with the potency of siduron diuron = diuron, differing from the observed in vitro sEH inhibition potency of siduron > desmethyl diuron > diuron. Further, siduron exposure synergized the toxicity of trans-stilbene oxide in fathead minnows. Medaka embryos exposed to diuron, desmethyl diuron, or siduron displayed dose-dependent delays in hatch, and elevated concentrations of diuron and desmethyl diuron produced developmental toxicity. The dose-dependent toxicity and in vivo sEH inhibition correlated, suggesting a potential, albeit undefined, relationship between these factors. Additionally, the observed inversion of in vitro to in vivo potency suggests that these fish models may provide tools for investigating the in vivo stability of in vitro inhibitors while screening for untoward effects. PMID:11171526

  4. Pharmacokinetics: time-dependent changes--autoinduction of carbamazepine epoxidation

    Bertilsson, L.; Tomson, T.; Tybring, G.

    1986-01-01

    Drugs labeled with stable isotopes have been useful to study time-dependent changes in kinetics. Early studies suggested that carbamazepine (CBZ) may induce its own metabolism, but this could not be proved until tetradeuterium-labeled CBZ (CBZ-D4) was synthesized and then given to patients. CBZ-D4 was administered to three children during long-term treatment of epilepsy with CBZ. After 17 to 32 days of treatment, the plasma clearance of CBZ-D4 was doubled, but during the next four months, there was no further increase, indicating that autoinduction was complete within one month. Two patients with chronic alcoholism were treated with CBZ for five days. Half of the first dose of 600 mg was comprised of CBZ-D4. The half-life of this CBZ-D4 dose in the two patients (20 and 26 hr, respectively) was similar to the post-steady-state half-life of CBZ (23 hr in both patients) measured later. A single dose of CBZ given one week after the last maintenance dose had a longer half-life (46 and 45 hr, respectively), which probably is close to the disposition of the drug before starting the treatment with CBZ. This shows that autoinduction of CBZ metabolism was completed during the very first doses of CBZ. Autoinduction also disappeared rapidly after stopping the treatment. We have shown that it is mainly the epoxide-diol pathway that is induced, both during autoinduction and after induction with other antiepileptic agents

  5. Enantioselective epoxidation with chiral MN(III)(salen) catalysts: kinetic resolution of aryl-substituted allylic alcohols.

    Adam, W; Humpf, H U; Roschmann, K J; Saha-Möller, C R

    2001-08-24

    A set of aryl-substituted allylic alcohols rac-2 has been epoxidized by chiral Mn(salen*) complexes 1 as the catalyst and iodosyl benzene (PhIO) as the oxygen source. Whereas one enantiomer of the allylic alcohol 2 is preferentially epoxidized to give the threo- or cis-epoxy alcohol 3 (up to 80% ee) as the main product (dr up to >95:5), the other enantiomer of 2 is enriched (up to 53% ee). In the case of 1,1-dimethyl-1,2-dihydronaphthalen-2-ol (2c), the CH oxidation to the enone 4c proceeds enantioselectively and competes with the epoxidation. The absolute configurations of the allylic alcohols 2 and their epoxides 3 have been determined by chemical correlation or CD spectroscopy. The observed diastereo- and enantioselectivities in the epoxidation reactions are rationalized in terms of a beneficial interplay between the hydroxy-directing effect and the attack along the Katsuki trajectory.

  6. [The effect of alpha-tocopherol and ionol on the physical structure of the membranes of rat liver microsomes under conditions of antioxidant insufficiency].

    Gubskiĭ, Iu I; Boldeskul, A E; Primak, R G; Zadorina, O V

    1989-01-01

    Physiochemical conformity of the alpha-tocopherol interaction with hepatic microsomal membranes has been studied by means of fluorescent probes (pyrene and 1-anilinonaphthalene-8-sulphonate). The microsomal membrane microviscosity is shown to sharply decrease under conditions of the antioxidant deficiency with vitamin E expelled into animals normalizes microviscosity, but feebly influences the microsomal surface charge. Microcalorimetry has been used to establish that penetration of tocopherol into microsomal membranes was accompanied by the exothermic effect.

  7. Green chemistry: Efficient epoxides ring-opening with 1-butanol under microwave irradiation

    Garcia-Vidal, Jesus A.; Duran-Valle, Carlos J.; Ferrera-Escudero, Santiago

    2006-01-01

    Two activated carbons treated with mineral acids (HNO 3 and sulfonitric mixture) have been tested as acid catalysts in the epoxides (1,2-epoxyhexane and styrene oxide) ring-opening reaction with 1-butanol under microwave (MW) irradiation. The mayor obtained product is that resulting of the alcohol addition to the most substituted carbon in the epoxide ring. The most active catalyst is that treated with sulfonitric mixture. The use of a MW oven allows achieving to the complete conversion of styrene oxide in only 2 min

  8. Bonding two surfaces by exposing to actinic radiation an epoxide liquid composition

    Green, G.E.

    1981-01-01

    A method for preparing a film adhesive from an epoxide resin is described. A liquid containing an epoxide resin and a photopolymerizable compound is polymerized to form a solid continuous film by exposure to actinide radiation. A catalyst can be used but no thermal crosslinking should be allowed to occur. The film so obtained is used to bond surfaces together by the application of heat and pressure. The period of heating can be very short, as there need be no solvent to evaporate and the films need not be thick, typically 20 to 250 μm. (O.T.)

  9. Soybean epoxide production with in situ peracetic acid using homogeneous catalysis

    Luis Alejandro Boyacá Mendivelso

    2010-01-01

    Full Text Available Using vegetable oils has become an excellent option for petrochemical product substitution. The epoxides obtained from such oils have wide applications as plastifiers and PVC stabilisers and as raw material in polyol synthesis for the polyurethane industry. This paper presents soybean oil epoxidation using a homogeneous catalyst in a well-mixed, stirred reactor being operated in iso- thermal conditions. The best result achieved was a 6.4% oxyrane oxygen content using hydrogen peroxide (25% molar excess, a- cetic acid (5% p/p and sulphuric acid (2% p/p concentrations at 80°C.

  10. Synthesis of Marine Polycyclic Polyethers via Endo-Selective Epoxide-Opening Cascades

    Timothy F. Jamison

    2010-03-01

    Full Text Available The proposed biosynthetic pathways to ladder polyethers of polyketide origin and oxasqualenoids of terpenoid origin share a dramatic epoxide-opening cascade as a key step. Polycyclic structures generated in these biosynthetic pathways display biological effects ranging from potentially therapeutic properties to extreme lethality. Much of the structural complexity of ladder polyether and oxasqualenoid natural products can be traced to these hypothesized cascades. In this review we summarize how such epoxide-opening cascade reactions have been used in the synthesis of ladder polyethers and oxasqualenoid natural products.

  11. Epoxidation of cyclohexene by ethyl-benzene hydroperoxide in the presence of molybdenum catalyst

    Sapunov, V.N.; Litvintsev, I.Yu.; Margitfal'vi, J.; Lebedev, N.N.

    1977-01-01

    A study has been made of the kinetic experimental pattern and mechanism of epoxidation of cyclohexene by ethylbenzene hydroperoxide during catalysis by Mo(CO) 6 in various solvents. A first order of reaction with respect to the catalyst and complex order of reaction with respect to the hydroperoxide and olefine have been established. Simple (square and cross) inhibition by reaction products, cyclohexene oxide and methylphenylcarbinol, have been found. An increase in the dielectric constant of the solvent diminishes the epoxidation rate. The mechanism scheme of the process is proposed and main kinetic parameters calculated

  12. Green chemistry: Efficient epoxides ring-opening with 1-butanol under microwave irradiation

    Garcia-Vidal, Jesus A. [Departamento de Quimica Inorganica, Facultad de Ciencias, Universidad de Extremadura, Campus Universitario, Avda. de Elvas, s/n, E-06071-Badajoz (Spain); Duran-Valle, Carlos J. [Departamento de Quimica Inorganica, Facultad de Ciencias, Universidad de Extremadura, Campus Universitario, Avda. de Elvas, s/n, E-06071-Badajoz (Spain)]. E-mail: carlosdv@unex.es; Ferrera-Escudero, Santiago [Departamento de Quimica Inorganica y Quimica Tecnica, Universidad Nacional de Educacion a Distancia, C/Senda del Rey, 9, E-28040 Madrid (Spain)

    2006-06-30

    Two activated carbons treated with mineral acids (HNO{sub 3} and sulfonitric mixture) have been tested as acid catalysts in the epoxides (1,2-epoxyhexane and styrene oxide) ring-opening reaction with 1-butanol under microwave (MW) irradiation. The mayor obtained product is that resulting of the alcohol addition to the most substituted carbon in the epoxide ring. The most active catalyst is that treated with sulfonitric mixture. The use of a MW oven allows achieving to the complete conversion of styrene oxide in only 2 min.

  13. Characterization Study of EPDM Rubber Vulcanized by Gamma Radiation in The Presence of Epoxidized Soybean Oil

    Radi, H.; Mousaa, I.M.

    2015-01-01

    Composites based on ethylene-propylene-diene rubber (EPDM) were prepared. EPDM loaded with 40 phr fumed silica in the presence of different concentrations of epoxidized soybean oil ranging between 4 and 8 phr. The composites were subjected to various gamma irradiation doses up to 200 kGy. The physical, mechanical and thermal properties of rubber composition as a function of irradiation dose were investigated. Gamma irradiation led to a significant improvement in the properties of the all compositions. Besides, an improvement in the mechanical properties was attained with the addition of 4 phr of epoxidized soybean oil.

  14. Increased risk for ovarian cancer and borderline ovarian tumours in subfertile women with endometriosis

    Buis, C. C. M.; van Leeuwen, F. E.; Mooij, T. M.; Burger, C. W.; Lambalk, Cornelis B.; Kortman, Marian; Laven, Joop S. E.; Jansen, Cees A. M.; Helmerhorst, Frans M.; Cohlen, Ben J.; Willemsen, Wim N. P.; Smeenk, Jesper M. J.; Simons, Arnold H. M.; van der Veen, Fulco; Evers, Johannes L. H.; van Dop, Peter A.; Macklon, Nicholas S.

    2013-01-01

    Is ovarian or extra-ovarian endometriosis associated with an increased risk of ovarian cancer and borderline ovarian tumours (BOT)? We found a 3- to 8-fold increased risk of ovarian tumours associated with endometriosis: the magnitude of the risk increase depended on the definition of endometriosis.

  15. Primary ovarian insufficiency: an update

    Cox L

    2014-02-01

    Full Text Available Leticia Cox, James H LiuUH Case Medical Center, MacDonald Women's Hospital, Department of Obstetrics and Gynecology, Case Western Reserve University School of Medicine, Department of Reproductive Biology, Cleveland, OH, USAAbstract: Primary ovarian insufficiency is a condition that represents impaired ovarian function on a continuum with intermittent ovulation. This condition commonly leads to premature menopause, defined as cessation of ovulation prior to the age of 40 years. Because there are potential immediate and long-term consequences of hypoestrogenism, a timely diagnosis is invaluable. This comprehensive review will discuss identifiable causes for primary ovarian insufficiency, including genetic disorders and metabolic abnormalities, as well as review current strategies for diagnosis, evaluation, and management of women with this condition.Keywords: premature ovarian failure, premature menopause, ovarian dysfunction

  16. Pediatric ovarian torsion: an uncommon clinical entity

    Rajwani, Kapil M; Mahomed, Anies

    2014-01-01

    Key Clinical Message Pediatric ovarian torsion is an infrequent diagnosis and it often mimics acute appendicitis. Most cases are due to underlying ovarian pathology and if left untreated, ovarian torsion may eventually cause peritonitis. Emergency exploratory laparoscopy represents a valuable diagnostic and therapeutic tool in suspected ovarian torsion.

  17. Glutathione delays varies as-tocopherol oxidation and subsequent lipid peroxidation in rat liver microsomes

    Robey, S.; Mavis, R.

    1986-01-01

    A method has been developed for in vitro trace radiolabeling of rat liver microsomes with 3 H-α-tocopherol (αT*) which allows virtually complete oxidation of the αT* under oxidizing conditions. The supernatant of a 16,000 xg centrifugation of homogenized rat liver, containing the cytosolic rat liver vitamin E (VE) transfer protein, was incubated with an ethanolic solution of αT* for 10 minutes at 37 0 C. Labeled microsomes were collected in the washed 100,000 xg pellet. Microsomes were then incubated with 30 μM Fe 2+ in an NADPH-generating system, and both production of malondialdehyde (MDA) (a product of lipid peroxidation) and oxidation of αT* were monitored over a time course in the presence and absence of glutathione (GSH). The results indicate virtually complete oxidation of αT* precedes significant membrane lipid peroxidation, and that addition of 5 mM GSH delays both αT* oxidation and subsequent MDA production. This suggests that the previously observed VE-dependent heat labile inhibition of microsomal lipid peroxidation by GSH involves maintaining membrane levels of α-tocopherol

  18. Photoaffinity labeling of steroid 5 alpha-reductase of rat liver and prostate microsomes

    Liang, T.; Cheung, A.H.; Reynolds, G.F.; Rasmusson, G.H.

    1985-01-01

    21-Diazo-4-methyl-4-aza-5 alpha-pregnane-3,20-dione (Diazo-MAPD) inhibits steroid 5 alpha-reductase in liver microsomes of female rats with a K/sub i/ value of 8.7 +/- 1.7 nM, and the inhibition is competitive with testosterone. It also inhibits the binding of a 5 alpha-reductase inhibitor, [ 3 H] 17 beta-N,N-diethylcarbamoyl-4-methyl-4-aza-5 alpha-androstan-3-one ([ 3 H]4-MA), to the enzyme in liver microsomes. The inhibition of 5 alpha-reductase activity and of inhibitor binding activity by diazo-MAPD becomes irreversible upon UV irradiation. [1,2- 3 H]Diazo-MAPD binds to a single high affinity site in liver microsomes of female rats, and this binding requires NADPH. Without UV irradiation, this binding is reversible, and it becomes irreversible upon UV irradiation. Both the initial reversible binding and the subsequent irreversible conjugation after UV irradiation are inhibited by inhibitors (diazo-MAPD and 4-MA) and substrates (progesterone and testosterone) of 5 alpha-reductase, but they are not inhibited by 5 alpha-reduced steroids. Photoaffinity labeled liver microsomes of female rats were solubilized and fractionated by high performance gel filtration. The radioactive conjugate eluted in one major peak at Mr 50,000

  19. Fungal microsomes in a biotransformation perspective: protein nature of membrane-associated reactions

    Svobodová, Kateřina; Mikesková, Hana; Petráčková, Denisa

    2013-01-01

    Roč. 97, č. 24 (2013), s. 10263-10273 ISSN 0175-7598 R&D Projects: GA TA ČR TE01020218 Institutional support: RVO:61388971 Keywords : Fungal microsomes * Cytochrome P450 * Biodegradation Subject RIV: EE - Microbiology, Virology Impact factor: 3.811, year: 2013

  20. Rat liver microsomal cytochrome P450-dependent oxidation of 3,5-disubstituted analogues of paracetamol

    Bessems, J.G.M.; Koppele, J.M. te; Dijk, P.A. van; Stee, L.L.P. van; Commandeur, J.N.M.; Vermeulen, N.P.E.

    1996-01-01

    1. The cytochrome P450-dependent binding of paracetamol and a series of 3,5-disubstituted paracetamol analogues (R = -F, -Cl, -Br, -I, -C(H)3, -C2H5, -iC3H7) have been determined with β-naphthoflavone (βNF)-induced rat liver microsomes and produced reverse type I spectral changes. K(s,app) varied

  1. Biosynthesis of intestinal microvillar proteins. Processing of aminopeptidase N by microsomal membranes

    Danielsen, E M; Norén, Ove; Sjöström, H

    1983-01-01

    -bound rather than a soluble form, indicating that synthesis of the enzyme takes place on ribosomes attached to the rough endoplasmic reticulum. The microsomal fractions process the Mr-115 000 polypeptide, which is the primary translation product of aminopeptidase N, to a polypeptide of Mr 140 000...

  2. In vitro inactivation of hepatic microsomal phospholipase A2 by the marine natural product manoalide

    Master, M.M.; Jacobs, R.S.

    1986-01-01

    The effects of manoalide (MLD) and several analogs (isolated from the sponge Luffariella variabilis) on mouse hepatic microsomal phospholipase A 2 (PLA 2 ) activity was investigated. Microsomal PLA 2 , a membrane bound, Ca ++ dependent enzyme with an alkaline pH optimum, functions in intracellular phospholipid turnover. In vitro PLA 2 activity was assayed by preincubating MLD or analogs (2.5-100μM) with microsomes for 60 min. at 37 0 C, combining this mixture with 14 C-phosphatidylcholine and CaCl 2 , and incubating at 37 0 C for 40 minutes. Enzyme activity was quantitated by measurement of the extracted 14 C-arachidonic acid product. MLD inhibited PLA 2 in a dose-dependent manner, with an IC 50 = 94μM. Lineweaver-Burk analysis suggests that MLD inhibits PLA 2 noncompetitively. One of the analogs, producing a comparable dose-response curve to MLD, was found to be more potent (IC 50 = 33μM). Another analog facilitated PLA 2 activity (15%) at 25μM, followed by inactivation at higher doses (IC 50 > 100 μM). Facilitation of PLA 2 activity was seen with concentrations as low as 2.5μM of a third analog, and significant inactivation of PLA 2 was evident. These results indicate that MLD is not as potent against microsomal PLA 2 as has been shown with purified bee venom and cobra venom PLA 2 's

  3. Development of vitamin D3 25-hydroxylase activity in rat liver microsomes

    Thierry-Palmer, M.; Cullins, S.; Rashada, S.; Gray, T.K.; Free, A.

    1986-01-01

    The authors have determined the ontogeny of vitamin D 3 25-hydroxylase activity in rat liver microsomes. Microsomes from fetuses, neonates, and their mothers were incubated with 44 nM 3 H-vitamin D 3 in the presence of an NADPH generating system, oxygen, KCl, and MgCl 2 . Lipid extracts of the incubation samples were partially purified by thin-layer chromatography. Tritiated 25-hydroxy vitamin D 3 (250HD 3 ) was analyzed by high-pressure liquid chromatography using 94/6 hexane/isopropanol. Production rate for 250HD 3 in the mothers ranged from 0.22 to 0.30 pmol/mg protein/hr. Activities in the fetuses and neonates were 2.1, 12.9, 32.0, 35.8, and 71.0% of that of their mothers at -3, 0, 2, 7, and 15 days of age. The cytosolic fraction protected the substrate from degradation, stimulated the vitamin D 3 25-hydroxylase reaction in neonates and mothers (1.4 to 1.7 fold increase), and was absolutely required for 25-hydroxylase activity in fetuses. These data suggest that microsomal vitamin D 3 25-hydroxylase activity develops slowly and approaches full activity near the weaning stage. A cytosolic factor present as early as -3 days of age stimulates the activity of the microsomal vitamin D 3 25-hydroxylase

  4. Mutagenicity of anthraquinone and hydroxylated anthraquinones in the Ames/Salmonella microsome system.

    Liberman, D F; Fink, R C; Schaefer, F L; Mulcahy, R J; Stark, A A

    1982-01-01

    The mutagenicity of anthracene, anthraquinone, and four structurally similar compounds of each was evaluated in the Ames/Salmonella microsome assay. Anthraquinone was shown to be mutagenic for strains TA1537, TA1538, and TA98 in the absence of rat liver homogenate. The four anthraquinone derivatives tested were mutagenic for TA1537 exclusively. None of the anthracenes exhibited mutagenic activity. PMID:7103489

  5. Mutagenicity of anthraquinone and hydroxylated anthraquinones in the Ames/Salmonella microsome system.

    Liberman, D F; Fink, R C; Schaefer, F L; Mulcahy, R J; Stark, A A

    1982-01-01

    The mutagenicity of anthracene, anthraquinone, and four structurally similar compounds of each was evaluated in the Ames/Salmonella microsome assay. Anthraquinone was shown to be mutagenic for strains TA1537, TA1538, and TA98 in the absence of rat liver homogenate. The four anthraquinone derivatives tested were mutagenic for TA1537 exclusively. None of the anthracenes exhibited mutagenic activity.

  6. Subtypes of Ovarian Cancer and Ovarian Cancer Screening

    Masafumi Koshiyama

    2017-03-01

    Full Text Available Ovarian cancer is the foremost cause of gynecological cancer death in the developed world, as it is usually diagnosed at an advanced stage. In this paper we discuss current issues, the efficacy and problems associated with ovarian cancer screening, and compare the characteristics of ovarian cancer subtypes. There are two types of ovarian cancer: Type I carcinomas, which are slow-growing, indolent neoplasms thought to arise from a precursor lesion, which are relatively common in Asia; and Type II carcinomas, which are clinically aggressive neoplasms that can develop de novo from serous tubal intraepithelial carcinomas (STIC and/or ovarian surface epithelium and are common in Europe and the USA. One of the most famous studies on the subject reported that annual screening using CA125/transvaginal sonography (TVS did not reduce the ovarian cancer mortality rate in the USA. In contrast, a recent study in the UK showed an overall average mortality reduction of 20% in the screening group. Another two studies further reported that the screening was associated with decreased stage at detection. Theoretically, annual screening using CA125/TVS could easily detect precursor lesions and could be more effective in Asia than in Europe and the USA. The detection of Type II ovarian carcinoma at an early stage remains an unresolved issue. The resolving power of CA125 or TVS screening alone is unlikely to be successful at resolving STICs. Biomarkers for the early detection of Type II carcinomas such as STICs need to be developed.

  7. Subtypes of Ovarian Cancer and Ovarian Cancer Screening.

    Koshiyama, Masafumi; Matsumura, Noriomi; Konishi, Ikuo

    2017-03-02

    Ovarian cancer is the foremost cause of gynecological cancer death in the developed world, as it is usually diagnosed at an advanced stage. In this paper we discuss current issues, the efficacy and problems associated with ovarian cancer screening, and compare the characteristics of ovarian cancer subtypes. There are two types of ovarian cancer: Type I carcinomas, which are slow-growing, indolent neoplasms thought to arise from a precursor lesion, which are relatively common in Asia; and Type II carcinomas, which are clinically aggressive neoplasms that can develop de novo from serous tubal intraepithelial carcinomas (STIC) and/or ovarian surface epithelium and are common in Europe and the USA. One of the most famous studies on the subject reported that annual screening using CA125/transvaginal sonography (TVS) did not reduce the ovarian cancer mortality rate in the USA. In contrast, a recent study in the UK showed an overall average mortality reduction of 20% in the screening group. Another two studies further reported that the screening was associated with decreased stage at detection. Theoretically, annual screening using CA125/TVS could easily detect precursor lesions and could be more effective in Asia than in Europe and the USA. The detection of Type II ovarian carcinoma at an early stage remains an unresolved issue. The resolving power of CA125 or TVS screening alone is unlikely to be successful at resolving STICs. Biomarkers for the early detection of Type II carcinomas such as STICs need to be developed.

  8. Ultrasonography of ovarian hyperandrogenemia

    Kuzmina, Svetlana A.; Zharkin, Nikolay A.

    2001-05-01

    The method of ultrasonography is high informative and widely used in diagnostics of ovarian hyperandrogenaemia. The majority of authors consider that a hyperplasia of a stroma is the main pathognomonic marker of polycystic ovaries (PCO). Still recently swell of a stroma was valued visually, that had subjective nature. We offer for the first time a way of diagnostics of stromal hyperplasia grounded on measurement of a volume of a stroma and ovary with ultrasound method, calculation of the ratio of a volume of the ovary to a volume of a stroma for every patient.

  9. Pelvic Inflammatory Disease and the Risk of Ovarian Cancer and Borderline Ovarian Tumors

    Rasmussen, Christina B; Kjaer, Susanne K; Albieri, Vanna

    2017-01-01

    Inflammation has been implicated in ovarian carcinogenesis. However, studies investigating the association between pelvic inflammatory disease (PID) and ovarian cancer risk are few and inconsistent. We investigated the association between PID and the risk of epithelial ovarian cancer according to...

  10. Incubation of 14C-trichloroethylene vapor with rat liver microsomes: uptake of radioactivity and covalent protein binding of metabolites

    Bolt, H.M.; Wolowski, L.; Buchter, A.; Bolt, W.; Gil, D.L.

    1977-01-01

    Microsomal uptake irreversible protein binding of labelled trichloroehtylene was measured following incubation with rat liver microsomes in an all-glass vacuum system. If the cofactor for oxidative metabolism, NADPH, is not added, the gaseous trichloroethylene rapidly equilibrates with the microsomal suspension. Addition of NADPH results in a further uptake of 14 C-trichloroethylene from the gas phase, linearly with time, which is due to enzymic metabolism. This part of uptake is inhibited by some arylimidazoles and 1.2.3-benzothiadiazoles. The compounds of greatest inhibitory potency were 6-chloro-1.2.3-benzothiadiazole and 5.6-dimethyl-1.2.3-benzothiadiazole. Part of the metabolites of 14 C-trichloroethylene formed by rat liver microsomes were irreversibly bound to microsomal protein, amounting up to 1 nmol per mg microsomal protein per hour. Model experiments on uptake of 14 C-trichloroethylene from the gas phase by albumin solutions and liposomal suspensions (from lecithin) showed a rapid equilibration of trichloroethylene also with these systems. Comparison with previous analogous data on vinyl chloride revealed an about 10 times higher affinity of trichloroethylene to albumin and lipid, consistent with the behaviour of both compounds in the rat liver microsomal system. (orig.) [de

  11. Soluble epoxide hydrolase in the generation and maintenance of high blood pressure in spontaneously hypertensive rats

    Koeners, Maarten P.; Wesseling, Sebastiaan; Ulu, Arzu; Lopez Sepulveda, Rocio; Morisseau, Christophe; Braam, Branko; Hammock, Bruce D.; Joles, Jaap A.

    Koeners MP, Wesseling S, Ulu A, Sepulveda RL, Morisseau C, Braam B, Hammock BD, Joles JA. Soluble epoxide hydrolase in the generation and maintenance of high blood pressure in spontaneously hypertensive rats. Am J Physiol Endocrinol Metab 300: E691-E698, 2011. First published January 25, 2011; doi:

  12. Chemoenzymatic epoxidation of alkenes with Candida antarctica lipase B and hydrogen peroxide in deep eutectic solvents

    Zhou, Pengfei; Wang, Xuping; Yang, Bo; Hollmann, F.; Wang, Yonghua

    2017-01-01

    Epoxides are important synthetic intermediates for the synthesis of a broad range of industrial products. This study presents a promising solution to the current limitation of enzyme instability. By using simple deep eutectic solvents such as choline chloride/sorbitol, significant stabilization

  13. The epoxide-diol pathway in the metabolism of vinylbital in rat and man

    Vermeulen, N P; Bakker, B H; Eylers, D; Breimer, D D

    1. In urine of rats given vinylbital (5-vinyl-5-(1'-methylbutyl)barbituric acid) i.p., unchanged vinylbital and its devinylated metabolite, 5-(1'-methylbutyl)barbituric acid, were identified. Rats synthetic 1',2'-epoxyvinylbital excreted the same compound as a major metabolite. No unchanged epoxide,

  14. Synthesis and Absolute Configuration of Enantiomerically Pure Vitamin K3 2,3-Epoxide

    Snatzke, Günther; Wijnberg, Hans; Feringa, Bernard; Marsman, Bea G.; Greydanus, Ben; Pluim, Henk

    1980-01-01

    The 2,3-epoxide of vitamin K3 (menadione, 1) has been prepared in enantiomerically pure form, and the absolute configuration has been deduced from the CD spectrum. The compound with the negative Cotton effect between 340 and 400 nm has the 2R,3S configuration.

  15. Salphen-Co(III) complexes catalyzed copolymerization of epoxides with CO2

    Hošťálek, Z.; Mundil, R.; Císařová, I.; Trhlíková, Olga; Grau, E.; Peruch, F.; Cramail, H.; Merna, J.

    2015-01-01

    Roč. 63, 20 April (2015), s. 52-61 ISSN 0032-3861 Institutional support: RVO:61389013 Keywords : cobalt salphen catalyst * CO2 epoxide copolymerization * MALDI-TOF Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.586, year: 2015

  16. An efficient hybrid, nanostructured, epoxidation catalyst: titanium silsesquioxane-polystyrene copolymer supported on SBA-15

    Santen, van R.A.; Zhang, Lei; Abbenhuis, H.C.L.; Gerritsen, G.; Ní Bhriain, N.M.; Magusin, P.C.M.M.; Mezari, B.; Han, W.; Yang, Q.; Li, Can

    2007-01-01

    A novel interfacial hybrid epoxidation catalyst was designed with a new immobilization method for homogeneous catalysts by coating an inorganic support with an organic polymer film containing active sites. The titanium silsesquioxane (TiPOSS) complex, which contains a single-site titanium active

  17. An efficient hybrid, nanostructured, epoxidation catalyst: titanium silsesquioxane-polystyrene copolymer supported on SBA-15.

    Zhang, Lei; Abbenhuis, Hendrikus C L; Gerritsen, Gijsbert; Bhriain, Nollaig Ní; Magusin, Pieter C M M; Mezari, Brahim; Han, Wei; van Santen, Rutger A; Yang, Qihua; Li, Can

    2007-01-01

    A novel interfacial hybrid epoxidation catalyst was designed with a new immobilization method for homogeneous catalysts by coating an inorganic support with an organic polymer film containing active sites. The titanium silsesquioxane (TiPOSS) complex, which contains a single-site titanium active center, was immobilized successfully by in-situ copolymerization on a mesoporous SBA-15-supported polystyrene polymer. The resulting hybrid materials exhibit attractive textural properties (highly ordered mesostructure, large specific surface area (>380 m2 g-1) and pore volume (>or==0.46 cm3 g-1)), and high activity in the epoxidation of alkenes. In the epoxidation of cyclooctene with tert-butyl hydrogen peroxide (TBHP), the hybrid catalysts have rate constants comparable with that of their homogeneous counterpart, and can be recycled at least seven times. They can also catalyze the epoxidation of cyclooctene with aqueous H2O2 as the oxidant. In two-phase reaction media, the catalysts show much higher activity than their homogeneous counterpart due to the hydrophobic environment around the active centers. They behave as interfacial catalysts due to their multifunctionality, that is, the hydrophobicity of polystyrene and the polyhedral oligomeric silsesquioxanes (POSS), and the hydrophilicity of the silica and the mesoporous structure. Combination of the immobilization of homogeneous catalysts on two conventional supports, inorganic solid and organic polymer, is demonstrated to achieve novel heterogeneous catalytic ensembles with the merits of attractive textural properties, tunable surface properties, and optimized environments around the active sites.

  18. Enhancement of catalyst performance in the direct propene epoxidation: a study into gold-titanium synergy

    Chen, J.; Halin, S.J.A.; Pidko, E.A.; Verhoeven, M.W.G.M.; Perez Ferrandez, D.M.; Hensen, E.J.M.; Schouten, J.C.; Nijhuis, T.A.

    2013-01-01

    Enhanced productivity toward propene oxide in the direct propene epoxidation with hydrogen and oxygen over gold nanoparticles supported on titanium-grafted silica was achieved by adjusting the gold–titanium synergy. Highly isolated titanium sites were obtained by lowering the titanium loading

  19. Synthesis and properties of cross-linked polymers from epoxidized rubber seed oil and triethylenetetramine

    Abduh, Muhammad Yusuf; Iqbal, Muhammad; Picchioni, Francesco; Manurung, Robert; Heeres, Hero J.

    2015-01-01

    A series of epoxidized oils were prepared from rubber seed, soybean, jatropha, palm, and coconut oils. The epoxy content varied from 0.03 to 7.4 wt %, in accordance with the degree of unsaturation of the oils (lowest for coconut, highest for rubber seed oil). Bulk polymerization/curing of the

  20. Synthesis of Chiral Cyclic Carbonates via Kinetic Resolution of Racemic Epoxides and Carbon Dioxide

    Xiao Wu

    2016-01-01

    Full Text Available The catalytic synthesis of cyclic carbonates using carbon dioxide as a C1-building block is a highly active area of research. Here, we review the catalytic production of enantiomerically enriched cyclic carbonates via kinetic resolution of racemic epoxides catalysed by metal-containing catalyst systems.

  1. Epoxidation of Alkenes with Aqueous Hydrogen Peroxide and Quaternary Ammonium Bicarbonate Catalysts

    Mielby, Jerrik Jørgen; Kegnæs, Søren

    2013-01-01

    A range of solid and liquid catalysts containing bicarbonate anions were synthesised and tested for the epoxidation of alkenes with aqueous hydrogen peroxide. The combination of bicarbonate anions and quaternary ammonium cations opens up for new catalytic systems that can help to overcome...

  2. UTL titanosilicate: An extra-large pore epoxidation catalyst with tunable textural properties

    Přech, Jan; Čejka, Jiří

    2016-01-01

    Roč. 277, č. 1 (2016), s. 2-8 ISSN 0920-5861 R&D Projects: GA ČR GBP106/12/G015 Institutional support: RVO:61388955 Keywords : titanosilicate UTL * top-down synthesis * epoxidation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.636, year: 2016

  3. Dinuclear ru-aqua complexes for selective epoxidation catalysis based on supramolecular substrate orientation effects

    Di Giovanni, Carlo; Poater, Albert; Benet-Buchholz, Jordi; Cavallo, Luigi; Solà , Miquel; Llobet, Antoni A.

    2014-01-01

    Ru-aqua complex {[RuII(trpy)(H2O)] 2(μ-pyr-dc)}+ is a powerful epoxidation catalyst for a wide range of linear and cyclic alkenes. High turnover numbers (TNs), up to 17000, and turnover frequencies (TOF), up to 24120 h-1 (6.7 s -1), have been obtained using PhIO as oxidant. This species presents an outstanding stereospecificity for both cis and trans olefins towards the formation of their corresponding cis and trans epoxides. In addition, it shows different reactivity to cis and trans olefins due to a substrate orientation supramolecular effect transmitted by its ligand scaffold. This effect together with the impressive reaction rates are rationalized using electrochemical techniques and DFT calculations. A new Ru-aqua complex that behaves as a powerful epoxidation catalyst for a wide range of linear and cyclic alkenes is reported. High turnover numbers and frequencies are obtained by using PhIO as oxidant. The complex shows an outstanding stereospecificity for both cis and trans olefins towards the formation of their corresponding cis and trans epoxides (see figure). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Functionalization of multi-walled carbon nanotubes by epoxide ring-opening polymerization

    Jin Fanlong; Rhee, Kyong Yop; Park, Soo-Jin

    2011-01-01

    In this study, covalent functionalization of carbon nanotubes (CNTs) was accomplished by surface-initiated epoxide ring-opening polymerization. FT-IR spectra showed that polyether and epoxide group covalently attached to the sidewalls of CNTs. TGA results indicated that the polyether was successfully grown from the CNT surface, with the final products having a polymer weight percentage of ca. 14–74 wt%. The O/C ratio of CNTs increased significantly from 5.1% to 29.8% after surface functionalization of CNTs. SEM and TEM images of functionalized CNTs exhibited that the tubes were enwrapped by polymer chains with thickness of several nanometers, forming core–shell structures with CNTs at the center. - Graphical abstract: Functionalized CNTs were enwrapped by polymer chains with thickness of several nanometers, forming core–shell structures with CNTs at the center. Highlights: ► CNTs were functionalized by epoxide ring-opening polymerization. ► Polyether and epoxide group covalently attached to the sidewalls of CNTs. ► Functionalized CNTs have a polymer weight percentage of ca. 14–74 wt%. ► Functionalized CNTs were enwrapped by polymer chains with thickness of several nanometers.

  5. Crack resistance increasing in epoxide-rubber coatings of NPP room floors

    Khorenzhenko, V.I.

    1986-01-01

    Problems of crack resistance increasing in epoxide-rubber coatings for the floors are considered. Exploitation experience of the floors in the special rooms of NPP is given. Perspectivity of application of the compositions described as the building materials for nuclear power stations is pointed out

  6. Improvement of enantioselectivity by immobilized imprinting of epoxide hydrolase from Rhodotorula glutinis

    Kronenburg, N.A.E.; Bont, de J.A.M.; Fischer, L.

    2001-01-01

    The yeast Rhodotorula glutinis contains an enantioselective, membrane-associated epoxide hydrolase (EH). Partially purified EH was immobilized in a two-step procedure. In the first step, the proteins were derivatized with itaconic anhydride. In the second step, the derivatized proteins were

  7. Cloning and characterization of an epoxide hydrolase-encoding gene from Rhodotorula glutinis

    Visser, H.; Vreugdenhil, S.; Bont, de J.A.M.; Verdoes, J.C.

    2000-01-01

    We cloned and characterized the epoxide hydrolase gene, EPH1, from Rhodotorula glutinis. The EPH1 open reading frame of 1230 bp was interrupted by nine introns and encoded a polypeptide of 409 amino acids with a calculated molecular mass of 46.3 kDa. The amino acid sequence was similar to that of

  8. Synthesis of epoxidized cardanol and its antioxidative properties for vegetable oils and biodiesel

    A novel antioxidant epoxidized cardanol (ECD), derived from cardanol, was synthesized and characterized by FT-IR, 1H-NMR and 13C-NMR. Oxidative stability of ECD used in vegetable oils and biodiesel was evaluated by pressurized differential scanning calorimetry (PDSC) and the Rancimat method, respect...

  9. (SalenMn(III Catalyzed Asymmetric Epoxidation Reactions by Hydrogen Peroxide in Water: A Green Protocol

    Francesco Paolo Ballistreri

    2016-07-01

    Full Text Available Enantioselective epoxidation reactions of some chosen reactive alkenes by a chiral Mn(III salen catalyst were performed in H2O employing H2O2 as oxidant and diethyltetradecylamine N-oxide (AOE-14 as surfactant. This procedure represents an environmentally benign protocol which leads to e.e. values ranging from good to excellent (up to 95%.

  10. Dinuclear ru-aqua complexes for selective epoxidation catalysis based on supramolecular substrate orientation effects

    Di Giovanni, Carlo

    2014-03-03

    Ru-aqua complex {[RuII(trpy)(H2O)] 2(μ-pyr-dc)}+ is a powerful epoxidation catalyst for a wide range of linear and cyclic alkenes. High turnover numbers (TNs), up to 17000, and turnover frequencies (TOF), up to 24120 h-1 (6.7 s -1), have been obtained using PhIO as oxidant. This species presents an outstanding stereospecificity for both cis and trans olefins towards the formation of their corresponding cis and trans epoxides. In addition, it shows different reactivity to cis and trans olefins due to a substrate orientation supramolecular effect transmitted by its ligand scaffold. This effect together with the impressive reaction rates are rationalized using electrochemical techniques and DFT calculations. A new Ru-aqua complex that behaves as a powerful epoxidation catalyst for a wide range of linear and cyclic alkenes is reported. High turnover numbers and frequencies are obtained by using PhIO as oxidant. The complex shows an outstanding stereospecificity for both cis and trans olefins towards the formation of their corresponding cis and trans epoxides (see figure). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Organo-bridged silsesquioxane titanates for heterogeneous catalytic epoxidation with aqueous hydrogen peroxide

    Wang, Y.M.; Magusin, P.C.M.M.; Santen, van R.A.; Abbenhuis, H.C.L.

    2007-01-01

    Organo-bridged silsesquioxane titanates for heterogeneous catalytic epoxidation with aqueous hydrogen peroxide were synthesized through the acid-catalyzed hydrolysis and co-condensation of organotrialkoxysilane monomers and a,¿-bis(trialkoxysilyl) alkane cross-linkers in ethanol–water solution, with

  12. Strengths, Weaknesses, Opportunities and Threats: Computational Studies of Mn- and Fe-Catalyzed Epoxidations

    Filipe Teixeira

    2016-12-01

    Full Text Available The importance of epoxides as synthetic intermediates in a number of highly added-value chemicals, as well as the search for novel and more sustainable chemical processes have brought considerable attention to the catalytic activity of manganese and iron complexes towards the epoxidation of alkenes using non-toxic terminal oxidants. Particular attention has been given to Mn(salen and Fe(porphyrin catalysts. While the former attain remarkable enantioselectivity towards the epoxidation of cis-alkenes, the latter also serve as an important model for the behavior of cytochrome P450, thus allowing the exploration of complex biological processes. In this review, a systematic survey of the bibliographical data for the theoretical studies on Mn- and Fe-catalyzed epoxidations is presented. The most interesting patterns and trends are reported and finally analyzed using an evaluation framework similar to the SWOT (Strengths, Weaknesses, Opportunities and Threats analysis performed in enterprise media, with the ultimate aim to provide an overview of current trends and areas for future exploration.

  13. Fertility drugs and ovarian cancer.

    Ali, Aus Tariq

    2017-06-20

    The aetiology of ovarian cancer is multifactorial with both endogenous and exogenous risk factors playing an important role. The exact pathogenesis of ovarian cancer is still not well understood, despite the number of hypotheses published. Due to an increase in the number of women using fertility drugs, much attention has been focused on the long-term health effects of such drugs. Although fertility drugs facilitate the ovulation process, it is however associated with a significant increase in hormone concentrations, placing exposed women at increased risk of gynaecological cancer. Many clinical and epidemiological studies have examined the association between fertility drugs and ovarian cancer risk. Results from these studies have been contradictory, as some studies have reported an increased risk of ovarian cancer while others reported no increased risk. Nevertheless, recent studies have shown that women who used fertility drugs and did not conceive had a higher risk of developing ovarian cancer, compared to women who used fertility drugs and conceived and delivered successfully. This review discusses the effect of fertility drugs on the risk of developing ovarian cancer, providing details on four possible scenarios associated with fertility treatment. In addition, the limitations of previous studies and their impact on our understanding of the association between fertility drugs and ovarian cancer also have been highlighted. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  14. In vitro metabolism of [14C]-toluene by human and rat liver microsomes and liver slices

    Chapman, D.E.; Moore, T.J.; Michener, S.R.; Powis, G.

    1990-01-01

    Toluene metabolites produced by liver microsomes from six human donors included benzylalcohol (Balc), benzaldehyde (Bald) and benzoic acid (Bacid). Microsomes from only one human donor metabolized toluene to p-cresol and o-cresol. Human liver microsomes also metabolized Balc to Bald. Balc metabolism required NADPH, was inhibited by carbon monoxide, and was decreased at a buffer pH of 10. Balc metabolism was not inhibited by ADP-ribose or sodium azide. These results suggest that cytochrome P450 is responsible for the in vitro metabolism of Balc by human liver microsomes. Toluene metabolites formed by human liver slices and released into the incubation media included hippuric acid, and Bacid. Cresols or cresol-conjugates were not detected in liver slice incubation media from any human donor. Toluene metabolism by human liver was compared to metabolism by comparable liver preparations from male Fischer F344 rats. Rates of toluene metabolism by human liver microsomes and liver slices were 9-fold and 1.3-fold greater than for rat liver, respectively. Covalent binding of toluene to human liver microsomes and liver slices was 21-fold and 4-fold greater than for comparable rat liver preparations. Covalent binding of toluene to human microsomes required NADPH, was significantly decreased by coincubation with 4 mM cysteine or 4 mM glutathione, and radioactivity associated with microsomes was decreased by subsequent digestion of microsomes with protease. These results suggest that toluene metabolism and covalent binding of toluene are underestimated if the male Fischer 344 rat is used as a model for human toluene metabolism

  15. Dysregulation of soluble epoxide hydrolase and lipidomic profiles in anorexia nervosa

    Shih, P. B.

    2015-03-31

    Individuals with anorexia nervosa (AN) restrict eating and become emaciated. They tend to have an aversion to foods rich in fat. Because epoxide hydrolase 2 (EPHX2) was identified as a novel AN susceptibility gene, and because its protein product, soluble epoxide hydrolase (sEH), converts bioactive epoxides of polyunsaturated fatty acid (PUFA) to the corresponding diols, lipidomic and metabolomic targets of EPHX2 were assessed to evaluate the biological functions of EPHX2 and their role in AN. Epoxide substrates of sEH and associated oxylipins were measured in ill AN, recovered AN and gender- and race-matched controls. PUFA and oxylipin markers were tested as potential biomarkers for AN. Oxylipin ratios were calculated as proxy markers of in vivo sEH activity. Several free- and total PUFAs were associated with AN diagnosis and with AN recovery. AN displayed elevated n-3 PUFAs and may differ from controls in PUFA elongation and desaturation processes. Cytochrome P450 pathway oxylipins from arachidonic acid, linoleic acid, alpha-linolenic acid and docosahexaenoic acid PUFAs are associated with AN diagnosis. The diol:epoxide ratios suggest the sEH activity is higher in AN compared with controls. Multivariate analysis illustrates normalization of lipidomic profiles in recovered ANs. EPHX2 influences AN risk through in vivo interaction with dietary PUFAs. PUFA composition and concentrations as well as sEH activity may contribute to the pathogenesis and prognosis of AN. Our data support the involvement of EPHX2-associated lipidomic and oxylipin dysregulations in AN, and reveal their potential as biomarkers to assess responsiveness to future intervention or treatment.

  16. Kinetics and mechanism of styrene epoxidation by chlorite: role of chlorine dioxide.

    Leigh, Jessica K; Rajput, Jonathan; Richardson, David E

    2014-07-07

    An investigation of the kinetics and mechanism for epoxidation of styrene and para-substituted styrenes by chlorite at 25 °C in the pH range of 5-6 is described. The proposed mechanism in water and water/acetonitrile includes seven oxidation states of chlorine (-I, 0, I, II, III, IV, and V) to account for the observed kinetics and product distributions. The model provides an unusually detailed quantitative mechanism for the complex reactions that occur in mixtures of chlorine species and organic substrates, particularly when the strong oxidant chlorite is employed. Kinetic control of the reaction is achieved by the addition of chlorine dioxide to the reaction mixture, thereby eliminating a substantial induction period observed when chlorite is used alone. The epoxidation agent is identified as chlorine dioxide, which is continually formed by the reaction of chlorite with hypochlorous acid that results from ClO produced by the epoxidation reaction. The overall stoichiometry is the result of two competing chain reactions in which the reactive intermediate ClO reacts with either chlorine dioxide or chlorite ion to produce hypochlorous acid and chlorate or chloride, respectively. At high chlorite ion concentrations, HOCl is rapidly eliminated by reaction with chlorite, minimizing side reactions between HOCl and Cl2 with the starting material. Epoxide selectivity (>90% under optimal conditions) is accurately predicted by the kinetic model. The model rate constant for direct reaction of styrene with ClO2(aq) to produce epoxide is (1.16 ± 0.07) × 10(-2) M(-1) s(-1) for 60:40 water/acetonitrile with 0.20 M acetate buffer. Rate constants for para substituted styrenes (R = -SO3(-), -OMe, -Me, -Cl, -H, and -NO2) with ClO2 were determined. The results support the radical addition/elimination mechanism originally proposed by Kolar and Lindgren to account for the formation of styrene oxide in the reaction of styrene with chlorine dioxide.

  17. Pilot scale production, characterization, and optimization of epoxidized vegetable oil-based resins

    Monono, Ewumbua Menyoli

    Novel epoxidized sucrose soyate (ESS) resins perform much better than other vegetable oil-based resins; thus, they are of current interest for commercial scale production and for a wide range of applications in coatings and polymeric materials. However, no work has been published that successfully scaled-up the reaction above a 1 kg batch size. To achieve this goal, canola oil was first epoxidized at a 300 g scale to study the epoxidation rate and thermal profile at different hydrogen peroxide (H2O2) addition rates, bath temperatures, and reaction times. At least 83% conversion of double bonds to oxirane was achieved by 2.5 h, and the reaction temperature was 8-15 °C higher than the water bath temperature within the first 30-40 min of epoxidation. A 38 L stainless steel kettle was modified as a reactor to produce 10 kg of ESS. Twenty 7-10 kg batches of ESS were produced with an overall 87.5% resin yield and > 98% conversion after batch three. The conversion and resin quality were consistent across the batches due to the modifications on the reaction that improved mixing and reaction temperature control within 55-65 oC. The total production time was reduced from 8 to 4 days due to the fabrication of a 40 L separatory funnel for both washing and filtration. A math model was developed to optimize the epoxidation process. This was done by using the Box-Behnken design to model the conversion at various acetic acid, H2O2, and Amberlite ratios and at various reaction temperatures and times. The model had an adjusted R2 of 97.6% and predicted R2 of 96.8%. The model showed that reagent amounts and time can be reduced by 18% without compromising the desired conversion value and quality.

  18. Synthesis and essay of an Ionomer like catalyst of olefins epoxidation

    Boyaca Mendivelso, Alejandro; Tempesti, Ezio

    1995-01-01

    The purpose of the present work is the preparation of an ionomer with base in Molybdenum and to evaluate its activity like catalyst of olefins epoxidation like alternative of synthesis of catalysts of the Hawk process. A polymer is synthesized with available functional groups to stabilize the metal starting from sodium molybdate; the characterization is made by atomic absorption, spectroscopy to GO, and X.P.S. The characterization indicates that indeed it is possible to stabilize the Mo in the main polymeric. The evaluation in reaction in liquid phase allows similar conversions to those of a homogeneous catalyst. The selective epoxidation of olefins for alkyl hydroperoxides, it has acquired great importance inside the industrial processes obtaining of propylene oxide due to the recent use of the terbutilic alcohol (co-produced together with the epoxide), as preservative in gasoline free of lead. In the environment of these processes, and in particular in the Hawk process possibilities of technological innovation, in the concerning to the heterogenization of conventional catalysts, at the moment used in homogeneous phase. The present work collaborate to some tentative that look for to generate alternative of preparation of catalysts for the process Hawk, synthesizing and testing the activity of an ionomer like epoxidation catalyst, which tries to reproduce the chemical structure of the complexes organ-metallic pear to suppress the separation stages and necessary recovery facilitating its recurrent reutilization with eventual economic repercussions in the industrial process. It is described the procedure of synthesis of the ionomer, the characterization and the evaluation of the activity in reaction under diverse conditions. Of the made characterization it comes off that the heterogenization of catalysts for olefins epoxidation, according to the Hawk process, is possible by means of the preparation of polymers modified appropriately. Likewise the evaluation in

  19. Ovarian size and response to laparoscopic ovarian electro-cauterization in polycystic ovarian disease.

    Alborzi, S; Khodaee, R; Parsanejad, M E

    2001-09-01

    To evaluate endocrine and ovulatory changes in polycystic ovarian disease (PCOD) in relation to patients' ovarian size. Three hundred and seventy-one women with clomiphene citrate-resistant PCOD underwent laparoscopic ovarian cauterization [type I or typical with ovarian volume >8 cm(3) or cross-sectional area >10 cm(2) (n=211), type II with normal size ovary (n=160)]. Serum levels of LH, FSH, DHEAS, PRL, and T before and 10 days after ovarian cautery, spontaneous and induced ovulation and pregnancy rates were compared. Both groups responded to therapy in a similar manner, with a marked decrease in LH, FSH, DHEAS and T levels, with ovulation rates in type I 90.99%, type II 88.75% and pregnancy rates, 73.45% and 71.25%, respectively, with no statistical differences. Hormonal changes, ovulation and pregnancy rates were similar in the two types of PCOD, therefore it can be concluded that ovarian size is not a prognostic factor for response of PCOD patients to laparoscopic ovarian electro-cauterization.

  20. Potent inhibition of cytochrome P450 2B6 by sibutramine in human liver microsomes.

    Bae, Soo Hyeon; Kwon, Min Jo; Choi, Eu Jin; Zheng, Yu Fen; Yoon, Kee Dong; Liu, Kwang-Hyeon; Bae, Soo Kyung

    2013-09-05

    The present study was performed to evaluate the potency and specificity of sibutramine as an inhibitor of the activities of nine human CYP isoforms in liver microsomes. Using a cocktail assay, the effects of sibutramine on specific marker reactions of the nine CYP isoforms were measured in human liver microsomes. Sibutramine showed potent inhibition of CYP2B6-mediated bupropion 6-hydroxylation with an IC50 value of 1.61μM and Ki value of 0.466μM in a competitive manner at microsomal protein concentrations of 0.25mg/ml; this was 3.49-fold more potent than the typical CYP2B6 inhibitor thio-TEPA (Ki=1.59μM). In addition, sibutramine slightly inhibited CYP2C19 activity (Ki=16.6μM, noncompetitive inhibition) and CYP2D6 activity (Ki=15.7μM, noncompetitive inhibition). These observations indicated 35.6- and 33.7-fold decreases in inhibition potency, respectively, compared with that of CYP2B6 by sibutramine. However, no inhibition of CYP1A2, CYP2A6, CYP2C8, CYP2C9, CYP2D6, or CYP2E1 activities was observed. In addition, the CYP2B6 inhibitory potential of sibutramine was enhanced at a lower microsomal protein concentration of 0.05mg/ml. After 30min preincubation of human liver microsomes with sibutramine in the presence of NADPH, no shift in IC50 was observed in terms of inhibition of the activities of the nine CYPs, suggesting that sibutramine is not a time-dependent inactivator. These observations suggest that sibutramine is a selective and potent inhibitor of CYP2B6 in vitro, whereas inhibition of other CYPs is substantially lower. These in vitro data support the use of sibutramine as a well-known inhibitor of CYP2B6 for routine screening of P450 reversible inhibition when human liver microsomes are used as the enzyme source. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  1. Fifth Ovarian Cancer Consensus Conference of the Gynecologic Cancer InterGroup (GCIG): clinical trial design for rare ovarian tumours

    Leary, A. F.; Quinn, M.; Fujiwara, K.; Coleman, R. L.; Kohn, E.; Sugiyama, T.; Glasspool, R.; Ray-Coquard, I.; Colombo, N.; Bacon, M.; Zeimet, A.; Westermann, A.; Gomez-Garcia, E.; Provencher, D.; Welch, S.; Small, W.; Millan, D.; Okamoto, A.; Stuart, G.; Ochiai, K.

    2017-01-01

    This manuscript reports the consensus statements on designing clinical trials in rare ovarian tumours reached at the fifth Ovarian Cancer Consensus Conference (OCCC) held in Tokyo, November 2015. Three important questions were identified concerning rare ovarian tumours (rare epithelial ovarian

  2. Epigenetic Characterization of Ovarian Cancer

    Murphy, Susan K

    2005-01-01

    .... The approach is to use normal ovarian surface epithelium (NOSE) and malignant cells obtained directly from surgically removed specimens in order to most closely approximate the methylation status in vivo...

  3. The reactivity of linseed and soybean oil with different epoxidation degree towards vinyl acetate and impact of the resulting copolymer on the wood durability

    M. Jebrane

    2017-05-01

    Full Text Available Linseed (LO and soybean oil (SO were in–situ epoxidized with peracetic acid to produce different degree of epoxidized LO and epoxidized SO. For comparison purpose, commercial epoxidized linseed oil (ELO® and epoxidized soybean oil (ESO® were also included in the study. The effect of epoxidation degree on the copolymerization reaction between epoxidized oils and vinyl acetate (VAc was investigated. Results showed that a copolymer can be formed between VAc and epoxidized LO with high epoxy content, while no reaction occurred between VAc and SO or its epoxidized derivatives. As the most reactive monomer among the studied oils, the epoxidized LO with highest epoxy content (i.e. ELO® was mixed with VAc and then impregnated into the wood using three different ELO®/VAc formulations either as solution or as emulsions. After curing, the impact of the resulting copolymer issued from the three tested formulations on the wood durability was evaluated. Results showed that the formulation comprising VAc, ELO®, H2O, K2S2O8 and alkaline emulsifier (Formulation 3 can significantly improve wood’s durability against white rot- (Trametes versicolor and brown rot fungi (Postia placenta and Coniophora puteana. Treated wood of 8% weight percentage gain (WPG was sufficient to ensure decay resistance against the test fungi with less than 5% mass loss.

  4. Ovarian torsion: Echographic discoveries

    Triana R, Gustavo; Navas O, Claudia

    1994-01-01

    Patient of 31 years who consulted to the even service of urgencies to present of two hours of evolution intense pain in flank and region lumbar left, associated to vomit, present square similar 5 previous days to the entrance in the right side. Go Po, plans with DIU FUR, 8 previous days to the square. It is practiced Tran abdominal pelvic echography that shows left ovary of 6 x 5 x 3 cms, with multiple follicular images, of thick walls, with I liquidate free abdominal, highly suggestive of ovarian torsion although the patient didn't present square of sharp abdomen. It decides to suspend analgesic and to value it, presented sharp abdominal pain, reason why laparotomy was practiced, finding mass of 6 x 6 cms. of necrotic aspect, corresponding to the left ovary, which presented three turns on their axis. It is taken finish left salpingooferectomy

  5. Polycystic ovarian syndrome

    Nina Madnani

    2013-01-01

    Full Text Available Polycystic ovarian syndrome (PCOS is a "multispeciality" disorder suspected in patients with irregular menses and clinical signs of hyperandrogenism such as acne, seborrhoea, hirsutism, irregular menses, infertility, and alopecia. Recently, PCOS has been associated with the metabolic syndrome. Patients may develop obesity, insulin resistance, acanthosis nigricans, Type 2 diabetes, dyslipidemias, hypertension, non-alcoholic liver disease, and obstructive sleep apnoea. Good clinical examination with hematological and radiological investigations is required for clinical evaluation. Management is a combined effort involving a dermatologist, endocrinologist, gynecologist, and nutritionist. Morbidity in addition includes a low "self image" and poor quality of life. Long term medications and lifestyle changes are essential for a successful outcome. This article focuses on understanding the normal and abnormal endocrine functions involved in the pathogenesis of PCOS. Proper diagnosis and management of the patient is discussed.

  6. Polycystic ovarian syndrome.

    Madnani, Nina; Khan, Kaleem; Chauhan, Phulrenu; Parmar, Girish

    2013-01-01

    Polycystic ovarian syndrome (PCOS) is a "multispeciality" disorder suspected in patients with irregular menses and clinical signs of hyperandrogenism such as acne, seborrhoea, hirsutism, irregular menses, infertility, and alopecia. Recently, PCOS has been associated with the metabolic syndrome. Patients may develop obesity, insulin resistance, acanthosis nigricans, Type 2 diabetes, dyslipidemias, hypertension, non-alcoholic liver disease, and obstructive sleep apnoea. Good clinical examination with hematological and radiological investigations is required for clinical evaluation. Management is a combined effort involving a dermatologist, endocrinologist, gynecologist, and nutritionist. Morbidity in addition includes a low "self image" and poor quality of life. Long term medications and lifestyle changes are essential for a successful outcome. This article focuses on understanding the normal and abnormal endocrine functions involved in the pathogenesis of PCOS. Proper diagnosis and management of the patient is discussed.

  7. A human cytochrome P-450 is recognized by anti-liver/kidney microsome antibodies in autoimmune chronic hepatitis.

    Kiffel, L; Loeper, J; Homberg, J C; Leroux, J P

    1989-02-28

    1- Anti-liver/kidney microsome autoantibodies type 1 (anti-LKM1), observed in some children with chronic active hepatitis, were used to isolate their antigen in human liver microsomes. A protein, called P-LKM1 was thus purified. This protein was recognized by a rabbit antiserum directed against the related human cytochromes P-450 bufI and P-450 bufII. 2- A human liver microsomal protein immunoprecipitated with anti-LKM1 sera was also recognized by anti cytochromes P-450 bufI/II antibodies. 3- Anti-LKM1 antibodies potently inhibited microsomal bufuralol 1'-hydroxylation. These results displayed the possible identity between cytochrome P-450 bufI/II and LKM1 antigen.

  8. [Association between obesity and ovarian cancer].

    Valladares, Macarena; Corsini, Gino; Romero, Carmen

    2014-05-01

    Obesity is a risk factor for cancer. Epidemiological evidences associate ovarian cancer with obesity. Epithelial ovarian cancer (EOC) is the most common type of ovarian cancer and accounts for a high rate of mortality. The association between ovarian cancer and obesity could be explained by molecular factors secreted by adipose tissue such as leptin. In EOC, leptin increases cell proliferation and inhibits apoptosis. Additionally, adipose tissue synthesizes endogenous estrogens, which increase cell proliferation of epithelial ovarian cells. Also, obesity associated hyperinsulinism could increase ovarian estrogen secretion.

  9. Management of ovarian cysts in infants.

    Xue-Qiang, Yan; Nan-Nan, Zheng; Lei, Yu; Wei, Lu; Hong-Qiang, Bian; Jun, Yang; Xu-Fei, Duan; Xin-Ke, Qin

    2015-12-01

    To discuss the experience of diagnosis and treatment of ovarian cyst in infants. A retrospective review was conducted on 20 infants who suffered from ovarian cyst. There were no dysplasia ovarian was found in children which were preoperatively diagnosed simplex cyst. Within thirteen children preoperatively detected mixed cystic-solid lesion, six cases ovarian cysts disappeared and two cases underwent poor blood supply in the following time. Adverse effects for ovarian cyst in infants can be prevented by agressive surgical intervention. Harmful effects of ovarian cyst can be prevented by positive surgical intervention despite the diagnostic difficulties in children with clinical symptoms of this condition.

  10. Premature ovarian failure

    Vujović Svetlana

    2012-01-01

    Full Text Available Premature ovarian failure (POF is the occurrence of hypergonadotropic hypoestrogenic amenorrhea in women under the age of forty years. It is idiopathic in 74-90% patients. Known cases can be divided into primary and secondary POF. In primary POF genetic aberrations can involve the X chromosome (monosomy, trisomy, translocations, deletions or autosomes. Genetic mechanisms include reduced gene dosage and non-specific chromosome effects impairing meiosis, decreasing the pool of primordial follicles and increasing atresia due to apoptosis or failure of follicle maturation. Autoimmune ovarian damage is caused by alteration of T-cell subsets and T-cell mediated injury, increase of autoantibody producing B-cells, a low number of effector/cytotoxic lymphocyte, which decreases the number and activity of natural killer cells. Bilateral oophorectomy, chemotherapy, radiotherapy and infections cause the secondary POF. Symptoms of POF include irritability, nervousness, loss of libido, depression, lack of concentration, hot flushes, weight gaining, dry skin, vaginal dryness, frequent infections etc. The diagnosis is confirmed by the level of FSH of over 40 IU/L and estradiol below 50 pmol/L in women aged below 40 years. Biochemical and other hormonal analysis (free thyroxin, TSH, prolactin, testosterone, karyotype (<30 years of age, ultrasound of the breasts and pelvis are advisable. Optimal therapy is combined estrogen progestagen therapy given in a sequential rhythm, after excluding absolute contraindications. Testosterone can be added to adnexectomized women and those with a low libido. Sequential estrogen progestagen replacement therapy is the first line therapy for ovulation induction in those looking for pregnancy and after that oocyte donation will be advised. Appropriate estro-progestagen therapy improves the quality of life and prevents complications such as cardiovascular diseases, osteoporosis, stroke etc.

  11. Tamoxifen and ovarian function.

    Martine Berliere

    Full Text Available BACKGROUND: Some studies suggest that the clinical parameter "amenorrhea" is insufficient to define the menopausal status of women treated with chemotherapy or tamoxifen. In this study, we investigated and compared the ovarian function defined either by clinical or biological parameters in pre-menopausal breast cancer patients treated with tamoxifen administered as adjuvant therapy. MATERIALS AND METHODS: Between 1999 and 2003, 138 premenopausal patients consecutively treated for early breast cancer were included. Sixty-eight received tamoxifen in monotherapy as the only adjuvant systemic treatment (Group I and 70 were treated with tamoxifen after adjuvant chemotherapy (Group II. All patients had a confirmed premenopausal status based on clinical parameters and hormonal values at study entry. They were followed prospectively every 3 months for 3 years: menses data, physical examination and blood tests (LH, FSH, 17-beta-estradiol. Vaginal ultrasonography was carried out every 6 months. After 3 years, prospective evaluation was completed and monitoring of ovarian function was performed as usual in our institution (1x/year. All data were retrospectively evaluated in 2011. RESULTS: Three patients were excluded from the study in group I and 2 were excluded in group II. Patients were divided into 4 subgroups according to clinical data, i.e. menses patterns. These patterns were assessed by questionnaires. a: Regular menses (>10 cycles/year b: Oligomenorrhea (5 to 9 cycles/year c: Severe oligomenorrhea (1 to 4 cycles/year d: Complete amenorrhea Estrogen levels did not appear to have any impact on disease-free survival rates after 3 or 8 years. FSH values were also documented and analyzed. They exhibited the same profile as estradiol values. CONCLUSIONS: Amenorrhea is an insufficient parameter to define menopausal status in patients receiving tamoxifen. Low estradiol levels must be coupled with other biological parameters to characterize endocrine status

  12. Hormone therapy and ovarian cancer

    Mørch, Lina Steinrud; Løkkegaard, Ellen; Andreasen, Anne Helms

    2009-01-01

    CONTEXT: Studies have suggested an increased risk of ovarian cancer among women taking postmenopausal hormone therapy. Data are sparse on the differential effects of formulations, regimens, and routes of administration. OBJECTIVE: To assess risk of ovarian cancer in perimenopausal and postmenopau......CONTEXT: Studies have suggested an increased risk of ovarian cancer among women taking postmenopausal hormone therapy. Data are sparse on the differential effects of formulations, regimens, and routes of administration. OBJECTIVE: To assess risk of ovarian cancer in perimenopausal...... and postmenopausal women receiving different hormone therapies. DESIGN AND SETTING: Nationwide prospective cohort study including all Danish women aged 50 through 79 years from 1995 through 2005 through individual linkage to Danish national registers. Redeemed prescription data from the National Register...... bands included hormone exposures as time-dependent covariates. PARTICIPANTS: A total of 909,946 women without hormone-sensitive cancer or bilateral oophorectomy. MAIN OUTCOME MEASURE: Ovarian cancer. RESULTS: In an average of 8.0 years of follow-up (7.3 million women-years), 3068 incident ovarian...

  13. One pot 'click' reactions : tandem enantioselective biocatalytic epoxide ring opening and [3+2] azide alkyne cycloaddition

    Campbell-Verduyn, Lachlan S.; Szymanski, Wiktor; Postema, Christiaan P.; Dierckx, Rudi A.; Elsinga, Philip H.; Janssen, Dick B.; Feringa, Ben L.

    2010-01-01

    Halohydrin dehalogenase (HheC) can perform enantioselective azidolysis of aromatic epoxides to 1,2-azido alcohols which are subsequently ligated to alkynes producing chiral hydroxy triazoles in a one-pot procedure with excellent enantiomeric excess.

  14. Acetanilide 4-hydroxylase and acetanilide 2-hydroxylase activity in hepatic microsomes from induced mice.

    Lewandowski, M; Chui, Y C; Levi, P; Hodgson, E

    1991-02-01

    A simple and sensitive method for the separation of 14C-labelled acetanilide, 4-hydroxyacetanilide, 3-hydroxyacetanilide and 2-hydroxyacetanilide was developed using thin-layer chromatography. This separation is the basis for the assay of acetanilide 4-hydroxylase and acetanilide 2-hydroxylase activity in liver microsomes from DBA2/N male mice that had been treated with phenobarbital, 3-methylcholanthrene, isosafrole or n-butylbenzodioxole. Microsomes were incubated with [14C]acetanilide and extracted with benzene and ethyl acetate. The extract was applied to silica gel plates and developed with a hexane/isopropanol/ammonium hydroxide/water solvent system. The radiolabelled phenolic metabolites and the parent compound were detected using a Berthold Automatic TLC Linear Analyzer. Although the 4-hydroxylated metabolite was the primary product detected, this method can be used to detect other phenolic metabolites.

  15. Major antigen of liver kidney microsomal autoantibodies in idiopathic autoimmune hepatitis is cytochrome P450db1.

    Manns, M P; Johnson, E F; Griffin, K J; Tan, E M; Sullivan, K F

    1989-01-01

    Type 1, liver kidney microsomal autoantibodies (LKM-1) are associated with a subgroup of idiopathic autoimmune type, chronic active hepatitis (CAH). The antigenic specificity of LKM-1 autoantibodies from 13 patients was investigated by immunoblot analysis of human liver microsomal proteins. Polypeptides of 50, 55, and 64 kD were detected with these antisera. A high titer LKM-1 serum was selected to screen a human liver lambda gt11 cDNA expression library, resulting in the isolation of several...

  16. Effect of p-amino-diphenyl ethers on hepatic microsomal cytochrome P450.

    Jiang, Huidi; Xuan, Guida

    2003-09-01

    The present paper aims to investigate whether p-amino-2',4'-dichlorodiphenyl ether and p-amino-4'-methyldiphenyl ether are inhibitors as well as inducers of P450. Mice were given daily intraperitoneal (ip) injections of p-amino-2',4'-dichlorodiphenyl ether (0.25 mmol/kg) or p-amino-4'-methyldiphenyl ether (0.25 mmol/kg) for 4 days and tested at 24 h and 48 h after the last dose injection. The results showed the mice pentobarbital sleeping time was shorter and the P450 content of hepatic microsome increased significantly in the group pretreated with p-amino-4'-methyldiphenyl ether when compared with the control group, while in mice pretreated with p-amino-2',4'-dichlorodiphenyl ether the hepatic microsome P450 content increased but the pentobarbital sleeping time was extended in clear contrast to the control group. The sleeping time of the phenobarbital group (80 mg/kg daily ip injection for 4 days) was shortened at 24 h after the last injection with increased P450 content of hepatic microsome, but it showed no difference at 48 h. The zoxazolamine-paralysis times of mice treated with p-amino-2',4'-dichlorodiphenyl ether were longer than those of the control mice, while the same dose of zoxazolamine did not lead to paralysis in mice pretreated with BNF. p-Amino-2',4'-dichlorodiphenyl ether and p-amino-4'-methyldiphenyl ether inhibited the activity of 7-ethoxyresorufin O-deethylase from rat hepatic microsome induced by BNF in vitro by 70.0% and 50.1% respectively. These results suggest that p-amino-2',4'-dichlorodiphenyl ether and p-amino-4'-methyldiphenyl ether are inhibitors as well as inducers of P450.

  17. Photoaffinity labeling of rat liver microsomal morphine UDP-glucuronosyltransferase by ( sup 3 H)flunitrazepam

    Thomassin, J.; Tephly, T.R. (Univ. of Iowa, Iowa City (USA))

    1990-09-01

    Benzodiazepines have been shown to competitively inhibit morphine glucuronidation in rat and human hepatic microsomes. Flunitrazepam exerted a potent competitive inhibition of rat hepatic morphine UDP-glucuronosyltransferase (UDPGT) activity (Ki = 130 microM). It has no effect on the activity of p-nitrophenol, 17 beta-hydroxysteroid, 3 alpha-hydroxysteroid, or 4-hydroxybiphenyl UDPGTs. Because flunitrazepam is an effective photoaffinity label for benzodiazepine receptors, studied were performed in solubilized rat hepatic microsomes and with partially purified preparations of morphine UDPGT to determine the enhancement of flunitrazepam inhibition and binding to morphine UDPGT promoted by exposure to UV light. Under UV light, flunitrazepam inhibition was markedly enhanced. UV light exposure also led to a marked increase in binding of (3H)flunitrazepam to microsomal protein, which was protected substantially by preincubation with morphine. Testosterone, androsterone, and UDP-glucuronic acid did not protect against UV-enhanced flunitrazepam binding, and morphine did not reverse flunitrazepam binding once binding had occurred. As morphine UDPGT was purified, a good correlation was found between the increases in specific activity of morphine UDPGT and flunitrazepam binding to protein. Chromatofocusing chromatography showed that flunitrazepam bound only to fractions containing active morphine UDPGT, and no binding to 4-hydroxybiphenyl UDPGT was observed. Fluorography of a sodium dodecyl sulfate-polyacrylamide electrophoresis gel of solubilized hepatic microsomes that had been treated with (3H) flunitrazepam under UV light revealed a band with a monomeric molecular weight between 54,000 and 58,000. This monomeric molecular weight compares favorably with the reported monomeric molecular weight of homogeneous morphine UDPGT (56,000).

  18. Microsomal aryl hydrocarbon hydroxylase comparison of the direct, indirect and radiometric assays

    Denison, M.S.; Murray, M.; Wilkinson, C.F.

    1983-01-01

    The direct fluorometric assay of aryl hydrocarbon hydroxlyase has been compared to the more commonly used indirect fluorometric and radiometric assays. Although rat hepatic microsomal activities measured by the direct assay were consistently higher than those obtained by the other assays, the relative changes in activity following enzyme induction and/or inhibition were similar. The direct assay provides an accurate and rapid measure of aryl hydrocarbon hydroxylase activity and avoids several problems inherent in the indirect and radiometric assays. 2 tables

  19. Metabolism of tributyltin and triphenyltin by rat, hamster and human hepatic microsomes

    Ohhira, Shuji; Watanabe, Masatomo; Matsui, Hisao [Department of Hygiene, Dokkyo University School of Medicine, Mibu-machi, 321-0293, Tochigi (Japan)

    2003-03-01

    Tributyltin and triphenyltin are metabolized by cytochrome P-450 system enzymes, and their metabolic fate may contribute to the toxicity of the chemicals. In the current study, the in vitro metabolism of tributyltin and triphenyltin by rat, hamster and human hepatic microsomes was investigated to elucidate the metabolic competence for these compounds in humans. The metabolic reaction using microsome-NADPH system that is usually conducted was not applicable to in vitro metabolism of organotins, especially triphenyltin. We therefore examined the effects of dithiothreitol (DTT), one of the antioxidants for sulfhydryl groups, to determine the in vitro metabolism of tributyltin and triphenyltin. As a result, the treatment with 0.1 mM DTT in vitro increased the activity of the microsomal monooxygenase system for metabolism of tributyltin as well as triphenyltin; the total yield of tributyltin and triphenyltin metabolites as tin increased, respectively, by approximately 1.8 and 8.9 times for rat, 2.1 and 1.2 times for hamster, and 1.6 and 1.5 times for human. It is suggested that the organotins directly inactivate cytochrome P-450 because of the interaction with critical sulfhydryl groups of the hemoprotein. We confirmed the utility of this in vitro metabolic system using DTT in the hepatic microsomes of phenobarbital (PB)-pretreated and untreated hamsters. Thus, the in vitro metabolic system described here was applied to a comparative study of the metabolism of organotins in rats, hamsters and humans. Tributyltin was metabolized more readily than triphenyltin in all the species. In humans, the in vitro metabolic pattern resembled that of hamsters, which were susceptible to in vivo triphenyltin toxicity because of incompetent metabolism. It is possible that the hamster is a qualitatively and quantitatively suitable animal model for exploring the influence of tributyltin and triphenyltin in humans. (orig.)

  20. Effect of radio-detoxified endotoxin on the liver microsomal drug metabolizing enzyme system in rats

    Bertok, L.; Szeberenyi, S.

    1983-01-01

    E. coli endotoxin (LPS) depresses the hepatic microsomal mono-oxygenase activity. Radio-detoxified LPS (TOLERIN: 60 Co irradiated endotoxin preparation) decreases this biotransforming activity to a smaller extent. Phenobarbital, an inducer of this mono-oxygenase system, failed to induce in LPS-treated animals. In radio-detoxified LPS-treated rats, phenobarbital induced the mono-oxygenase and almost fully restored the biotransformation

  1. CHARACTERIZATION OF HUMAN LIVER MICROSOMAL UDP-GLYCOSYLTRANSFERASES USING PHOTOAFFINITY ANALOGS

    LITTLE, JM; DRAKE, RR; VONK, R; KUIPERS, F; LESTER, R; RADOMINSKA, A

    The photoaffinity analogs [beta-P-32]5-azido-UDP-glucuronic acid ([P-32]5N3UDP-GlcUA) and [beta-P-32]5-azido-UDP-glucose ([P-32]5N(3)UDP-Glc) were used to characterize UDP-glycosyl-transferases of microsomes prepared from human liver. Photoincorporation of both probes into proteins in the 50- to

  2. High affinity binding of [3H]cocaine to rat liver microsomes

    El-Maghrabi, E.A.; Calligaro, D.O.; Eldefrawi, M.E.

    1988-01-01

    ] 3 H]cocaine bound reversible, with high affinity and stereospecificity to rat liver microsomes. Little binding was detected in the lysosomal, mitochondrial and nuclear fractions. The binding kinetics were slow and the kinetically calculated K/sub D/ was 2 nM. Induction of mixed function oxidases by phenobarbital did not produce significant change in [ 3 H]cocaine binding. On the other hand, chronic administration of cocaine reduced [ 3 H]cocaine binding drastically. Neither treatment affected the affinity of the liver binding protein for cocaine. Microsomes from mouse and human livers had less cocaine-binding protein and lower affinity for cocaine than those from rat liver. Binding of [ 3 H]cocaine to rat liver microsomes was insensitive to monovalent cations and > 10 fold less sensitive to biogenic amines than the cocaine receptor in rat striatum. However, the liver protein had higher affinity for cocaine and metabolites except for norcocaine. Amine uptake inhibitors displaced [ 3 H]cocaine binding to liver with a different rank order of potency than their displacement of [ 3 H]cocaine binding to striatum. This high affinity [ 3 H]cocaine binding protein in liver is not likely to be monooxygenase, but may have a role in cocaine-induced hepatotoxicity

  3. [Comparative metabolism of three amide alkaloids from Piper longum in five different species of liver microsomes].

    He, Huan; Guo, Wei-Wei; Chen, Xiao-Qing; Zhao, Hai-Yu; Wu, Xia

    2016-08-01

    Piperine, piperlonguminine and pellitorine are three major amide alkaloids from Piper longum, showing a variety of pharmacological activities. In order to investigate the different metabolism pathways of these compounds in five species of liver microsomes in vitro, the data of full mass spectrum, and MS2, MS3 spectra of these three alkaloids were collected and analyzed by using ultra-high-performance liquid chromatography coupled with a LTQ-orbitrap mass spectrometer (UHPLC-LTQ-Orbitrap MS); gragment ion information was collected and combined with fragmentation regularities of mass spectra and accurate mass spectrometry data of metabolites, to compare the metabolism difference of three amide alkaloids in liver microsomes of human, rhesus monkey, Beagle dogs, rats and mice. 3 metabolites of piperine, 2 metabolites of piperlonguminine and 1 metabolite of pellitorine were identified quickly. The results showed that the major metabolic pathways of these amide alkaloids in liver microsomes were methylenedioxy group demethylation and oxidation reaction, and metabolic rates were different between species. This study provides basis for further research on in vivo metabolism of piperine analogues from Piper longum. Copyright© by the Chinese Pharmaceutical Association.

  4. The tobacco carcinogen NNK is stereoselectively reduced by human pancreatic microsomes and cytosols.

    Trushin, Neil; Leder, Gerhard; El-Bayoumy, Karam; Hoffmann, Dietrich; Beger, Hans G; Henne-Bruns, Doris; Ramadani, Marco; Prokopczyk, Bogdan

    2008-07-01

    Cigarette smoking increases the risk of cancer of the pancreas. The tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is the only known environmental compound that induces pancreatic cancer in laboratory animals. Concentrations of NNK are significantly higher in the pancreatic juice of smokers than in that of nonsmokers. The chiral NNK metabolite, (R,S)-4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) is itself a potent pancreatic carcinogen in rats. The carcinogenicity of NNAL is related to its stereochemistry; (S)-NNAL is a more potent lung tumorigen in the A/J mouse than is (R)-NNAL. In this study, we determined the potential of the human pancreas to convert NNK into NNAL. Human pancreatic microsomes and cytosols were incubated with [5-(3)H]NNK, and the metabolic products were determined by high-performance liquid chromatography (HPLC). (S)-NNAL was the predominant isomer formed in all cytosolic incubations. In ten microsomal samples, NNAL was formed at an average rate of 3.8 +/- 1.6 pmol/mg/min; (R)-NNAL was the predominant isomer in this group. The average rate of NNAL formation in 18 other microsomal samples was significantly lower, 0.13 +/- 0.12 pmol/mg/min (p < 0.001); (S)-NNAL was the predominant isomer formed in this group. In human pancreatic tissues, there is intraindividual variability regarding the capacity for, and stereoselectivity of, carbonyl reduction of NNK.

  5. Inhibition of rat mammary microsomal oxidation of ethanol to acetaldehyde by plant polyphenols.

    Maciel, María Eugenia; Castro, José Alberto; Castro, Gerardo Daniel

    2011-07-01

    We previously reported that the microsomal fraction from rat mammary tissue is able to oxidize ethanol to acetaldehyde, a mutagenic-carcinogenic metabolite, depending on the presence of NADPH and oxygen but not inhibited by carbon monoxide or other cytochrome P450 inhibitors. The process was strongly inhibited by diphenyleneiodonium, a known inhibitor of NADPH oxidase, and by nordihydroguaiaretic acid, an inhibitor of lipoxygenases. This led us to suggest that both enzymes could be involved. With the purpose of identifying natural compounds present in food with the ability to decrease the production of acetaldehyde in mammary tissue, in the present studies, several plant polyphenols having inhibitory effects on lipoxygenases and of antioxidant nature were tested as potential inhibitors of the rat mammary tissue microsomal pathway of ethanol oxidation. We included in the present screening study 32 polyphenols having ready availability and that were also tested against the rat mammary tissue cytosolic metabolism of ethanol to acetaldehyde. Several polyphenols were also able to inhibit the microsomal ethanol oxidation at concentrations as low was 10-50 μM. The results of these screening experiments suggest the potential of several plant polyphenols to prevent in vivo production and accumulation of acetaldehyde in mammary tissue.

  6. Defect Stabilized Gold Atoms on Graphene as Potential Catalysts for Ethylene Epoxidation: A First-principles Investigation

    Liu, Xin; Yang, Yang; Chu, Minmin; Duan, Ting; Meng, Changgong; Han, Yu

    2015-01-01

    We performed a first-principles based investigation on the potential role of Au atoms stabilized by defects on graphene in ethylene epoxidation. We showed that the interactions between the Au atoms and vacancies on graphene not only make the Au atomic diffusion a 2.10 eV endothermic process, but also tune the energy level of Au-d states for the activation of O2 and ethylene and promote the formation and dissociation of the peroxametallacycle intermediate. The catalytic cycle of ethylene epoxidation is initiated with the formation of a peroxametallacycle intermediate by the coadsorbed ethylene and O2, through the dissociation of which an ethylene epoxide molecule and an adsorbed O atom are formed. Then, gaseous ethylene reacts with the remnant O atom directly for the formation of another ethylene epoxide molecule. The desorption of ethylene epoxide is facilitated by the subsequent adsorption of O2 or ethylene and a new reaction cycle initiates. The calculated energy barriers for the formation and dissociation of the peroxametallacycle intermediate and the regeneration of Au sites are 0.30, 0.84 and 0.18 eV, respectively, and are significantly lower than those for aldehyde formation. These findings suggest the potential high catalytic performance of these Au atoms for ethylene epoxidation.

  7. Defect Stabilized Gold Atoms on Graphene as Potential Catalysts for Ethylene Epoxidation: A First-principles Investigation

    Liu, Xin

    2015-11-24

    We performed a first-principles based investigation on the potential role of Au atoms stabilized by defects on graphene in ethylene epoxidation. We showed that the interactions between the Au atoms and vacancies on graphene not only make the Au atomic diffusion a 2.10 eV endothermic process, but also tune the energy level of Au-d states for the activation of O2 and ethylene and promote the formation and dissociation of the peroxametallacycle intermediate. The catalytic cycle of ethylene epoxidation is initiated with the formation of a peroxametallacycle intermediate by the coadsorbed ethylene and O2, through the dissociation of which an ethylene epoxide molecule and an adsorbed O atom are formed. Then, gaseous ethylene reacts with the remnant O atom directly for the formation of another ethylene epoxide molecule. The desorption of ethylene epoxide is facilitated by the subsequent adsorption of O2 or ethylene and a new reaction cycle initiates. The calculated energy barriers for the formation and dissociation of the peroxametallacycle intermediate and the regeneration of Au sites are 0.30, 0.84 and 0.18 eV, respectively, and are significantly lower than those for aldehyde formation. These findings suggest the potential high catalytic performance of these Au atoms for ethylene epoxidation.

  8. [Peripubertal ovarian cyst torsion as an early complication of undiagnosed polycystic ovarian syndrome].

    Ságodi, László; Schmidt, Ildikó; Vámosi, Ildikó; Barkai, László

    2013-01-20

    The aim of the authors is to present two cases which raise the possibility of an association between polycystic ovarian syndrome/hyperandrogenism and ovarian cyst torsion in peripubertal girls. Androgen excess may cause more frequently ovarian cyst formation in premenarcheal or young adolescents with undiagnosed polycystic ovarian syndrome than in adults. The authors recommend that polycystic ovarian syndrome as well as late onset congenital adrenal hyperplasia should be considered in peripubertal adolescents with ovarian cyst torsion. In case polycystic ovarian syndrome is confirmed, adequate management according to age and pubertal development of the patients should be commenced.

  9. Stage at diagnosis and ovarian cancer survival

    Maringe, Camille; Walters, Sarah; Butler, John

    2012-01-01

    We investigate what role stage at diagnosis bears in international differences in ovarian cancer survival.......We investigate what role stage at diagnosis bears in international differences in ovarian cancer survival....

  10. Synthesis and characterization of new magnetically recoverable molybdenum nanocatalyst for epoxidation of olefins

    Masteri-Farahani, M., E-mail: mfarahany@yahoo.com [Faculty of Chemistry, University of Tarbiat Moallem, Tehran (Iran, Islamic Republic of); Kashef, Z. [Faculty of Chemistry, University of Tarbiat Moallem, Tehran (Iran, Islamic Republic of)

    2012-04-15

    New heterogeneous molybdenum catalyst was prepared through covalent attachment of a Schiff base ligand on the surface of silica coated magnetite nanoparticles via aminopropyl spacer and subsequent complexation with MoO{sub 2}(acac){sub 2}. The prepared nanocatalyst was characterized with Fourier transform infrared spectroscopy, X-ray diffraction, scanning and transmission electron microscopies and vibrating sample magnetometry. Catalytic epoxidation of some olefins and allylic alcohols by prepared nanocatalyst using tert-butyl hydroperoxide and cumene hydroperoxide as oxidants was achieved with good activities and selectivities. - Highlights: Black-Right-Pointing-Pointer Silica coated magnetite nanoparticles were modified with a Schiff base ligand. Black-Right-Pointing-Pointer Next reaction with MoO{sub 2}(acac){sub 2} afforded magnetically recoverable nanocatalyst. Black-Right-Pointing-Pointer The prepared nanocatalyst catalyzed the epoxidation of olefins with TBHP.

  11. An investigation into the Ti-grafting structure on MCM-41 and epoxidation catalysis

    Yuan, Q.C.; Hagen, A.; Roessner, F.

    2006-01-01

    The structure of titanium species grafted on a purely siliceous MCM-41 and their catalysis in the epoxidation of cyclohexene with tert-butyl hydroperoxide (TBHP) were investigated. FT-IR, XANES and UV-vis were used for the examination of the Ti-grafted MCM-41. The results indicated...... that the titanium atoms are grafted on the wall surface of the MCM-41 by four-fold coordination. The four-fold coordinated titanium species are mainly grafted by two or one -O-Si-O- bridges on the MCM-41, resulting in so-called bipodal or monopodal titanium centres in partially polymerised states. The ratio...... of monopodal to bipodal titanium increases with the increase in Ti-content. These partially polymerised titanium species considered as catalytic active centres have high activity and selectivity in the epoxidation reaction. The used Ti-grafted MCM-41 samples were regenerated by heating in nitrogen or air...

  12. Discovery and characterization of thermophilic limonene-1,2-epoxide hydrolases from hot spring metagenomic libraries

    Ferrandi, Erica Elisa; Sayer, Christopher; Isupov, Michail N.

    2015-01-01

    thermophilic sources, have higher optimal temperatures and apparent melting temperatures than Re-LEH. The new LEH enzymes have been crystallized and their structures solved to high resolution in the native form and in complex with the inhibitor valpromide for Tomsk-LEH and poly(ethylene glycol) for CH55-LEH......,2-epoxide hydrolase (LEH) family of enzymes. These two LEHs (Tomsk-LEH and CH55-LEH) show EH activities towards different epoxide substrates, differing in most cases from those previously identified for Rhodococcus erythropolis (Re-LEH) in terms of stereoselectivity. Tomsk-LEH and CH55-LEH, both from....... The structural analysis has provided insights into the LEH mechanism, substrate specificity and stereoselectivity of these new LEH enzymes, which has been supported by mutagenesis studies....

  13. Exploiting epoxidized natural rubber latex (ENRL) as a starting raw material for latex-based products

    Siti Nor Qamarina, M.; Fatimah Rubaizah, M. R.; Nurul Suhaira, A.; Norhanifah, M. Y.

    2017-12-01

    Epoxidized natural rubber latex (ENRL) is a chemically modified natural rubber latex produced from epoxidation process that involves usage of organic peracids. Conversion of the ENRL into dry rubber products has been known to exhibit many beneficial properties, however limited published works were found on diversifiying the ENRL latex-based products applications. In this preliminary work, different source of raw materials and neutralization systems were investigated. The objective was to explore possibilities in producing distinctive ENRL. Findings have demonstrated that different source of raw materials and neutralization systems influenced the typical ENRL specifications, stability behavior and particle size distribution. Morphological observations performed on these ENRL systems appeared to agree with the ENRL characteristics achieved. Since experimenting these two main factors resulted in encouraging ENRL findings, detailed work shall be further scrutinized to search for an optimum condition in producing marketable ENRL specifically for latex-based products applications.

  14. Stabilizing effect of epoxidized sunflower oil as a secondary stabilizer for Ca/Hg stabilized PVC

    2008-01-01

    Full Text Available Unsaturated triglyceride oil sunflower was epoxidized and characterized by chemical and spectroscopic methods. Epoxidized sunflower oil (ESO was used as an organic thermal co-stabilizer for rigid poly(vinyl chloride (PVC in the presence of tricalcium dicitrate (Ca3(C6H5O72 and mercury (II acetate (Hg(CH3COO2. The thermo-oxidative degradation of PVC was studied in the presence of these ternary stabilizer systems at 170, 180, 190 and 200°C in N2 atmosphere. The effects of metal carboxylate combination Ca/Hg in the absence and in the presence of epoxidized sunflower oil on static heat treatment of PVC have been studied. The formation of polyene sequences was investigated by UV-visible and FT-IR spectroscopy and by comparing viscosity data obtained in the presence and in the absence of the additives. It was found that the additives retard the rate of degradation and reduce the extent of polymer chain scission associated with the thermal degradation of poly(vinyl chloride. Synergistic effects were found when stabilizer was blended in 50:50 weight ratios with either. It was found that ESO exerted a stabilizing effect on the degradation of PVC. The activation energy for degraded PVC in absence of stabilizers was 38.6 kJ•mol–1 and in the presence of Ca/Hg and Ca/Hg/ESO were 53.3 and 64.7 kJ•mol–1 respectively. In order of compare the efficiency of the epoxidized sunflower oil with these metal soap stabilizers, thermal stabilities were evaluated on the basis of evolved hydrogen chloride determined by conductometry technique and degree of discoloration are discussed.

  15. Supported sub-nanometer Ta oxide clusters as model catalysts for the selective epoxidation of cyclooctene

    Zwaschka, Gregor; Rondelli, Manuel; Krause, Maximilian; Rö tzer, Marian David; Hedhili, Mohamed N.; Heiz, Ulrich; Basset, Jean-Marie; Schweinberger, Florian; D'Elia, Valerio

    2018-01-01

    The preparation of organic ligands-free, isolated tantalum oxide atoms (Ta1) and small clusters (Tan>1) on flat silicate supports was accomplished by ultra-high vacuum (UHV) techniques followed by oxidation in air. The resulting surface complexes were thoroughly characterized and tested as supported catalysts for the epoxidation of cycloalkenes. The observed catalytic performance highlights the potential of the applied method for the production of active catalysts and the study of well-defined, ligand-free metal oxide moieties.

  16. Supported sub-nanometer Ta oxide clusters as model catalysts for the selective epoxidation of cyclooctene

    Zwaschka, Gregor

    2018-01-22

    The preparation of organic ligands-free, isolated tantalum oxide atoms (Ta1) and small clusters (Tan>1) on flat silicate supports was accomplished by ultra-high vacuum (UHV) techniques followed by oxidation in air. The resulting surface complexes were thoroughly characterized and tested as supported catalysts for the epoxidation of cycloalkenes. The observed catalytic performance highlights the potential of the applied method for the production of active catalysts and the study of well-defined, ligand-free metal oxide moieties.

  17. The stability of the three transmembrane and the four transmembrane human vitamin K epoxide reductase models

    Wu, Sangwook

    2016-04-01

    The three transmembrane and the four transmembrane helix models are suggested for human vitamin K epoxide reductase (VKOR). In this study, we investigate the stability of the human three transmembrane/four transmembrane VKOR models by employing a coarse-grained normal mode analysis and molecular dynamics simulation. Based on the analysis of the mobility of each transmembrane domain, we suggest that the three transmembrane human VKOR model is more stable than the four transmembrane human VKOR model.

  18. An Update on Ovarian Aging and Ovarian Reserve Tests

    Migraci Tosun

    2016-12-01

    Full Text Available Ovaries are the female organs that age more quickly than other tissues such as the uterus, the pituitary gland or pancreas. Different from males, an interesting question is why and how the females lose fertility so rapidly. During the aging process, both the number and quality of the oocytes in the ovaries decrease and reach to a point beyond that no more viable offspring may be produced and the associated cyclic endocrinological activities cease, entering the menopause in females at an average age of 50 years. Females who delayed childbearing with or without their willing until their 30 years or 40 years constitute the largest portion of the total infertility population. Ovarian reserve tests (ORTs provide an indirect estimate of a female�s diminishing ovarian reserve or remaining follicular pool. This article briefly reviews recent progresses in relation to ovarian aging and ORTs.

  19. Anti-Mullerian hormone and ovarian dysfunction

    Broekmans, Frank J.; Visser, Jenny A.; Laven, Joop S. E.; Broer, Simone L.; Themmen, Axel P. N.; Fauser, Bart C.

    2008-01-01

    Anti-Mullerian hormone (AMH) has important roles in postnatal ovarian function. Produced by ovarian granulosa cells, AMH is involved in initial follicle development. In fact, serum AMH level correlates with ovarian follicle number. In patients with polycystic ovary syndrome (PCOS), AMH levels are

  20. Persistence and changes in bioavailability of dieldrin, DDE and heptachlor epoxide in earthworms over 45 years

    Beyer, W. Nelson; Gale, Robert W.

    2013-01-01

    The finding of dieldrin (88 ng/g), DDE (52 ng/g), and heptachlor epoxide (19 ng/g) in earthworms from experimental plots after a single moderate application (9 kg/ha) 45 years earlier attests to the remarkable persistence of these compounds in soil and their continued uptake by soil organisms. Half-lives (with 95 % confidence intervals) in earthworms, estimated from exponential decay equations, were as follows: dieldrin 4.9 (4.3-5.7) years, DDE 5.3 (4.7-6.1) years, and heptachlor epoxide 4.3 (3.8-4.9) years. These half-lives were not significantly different from those estimated after 20 years. Concentration factors (dry weight earthworm tissue/dry weight soil) were initially high and decreased mainly during the first 11 years after application. By the end of the study, average concentration factors were 1.5 (dieldrin), 4.0 (DDE), and 1.8 (heptachlor epoxide), respectively.

  1. Optimization of the In Situ Epoxidation of Linoleic Acid of Jatropha Curcas Oil With Performic Acid

    Hong, L.K.; Rahimi Mohd Yusop; Nadia Salih; Jumat Salimon

    2015-01-01

    The aim of this study is to optimise the epoxidation of linoleic acid of Jatropha curcas oil. This experiment was carried out with performic acid generated in situ by using hydrogen peroxide and formic acid. The method was evaluated on different parameters such as reaction temperature, mole ratios of formic acid to ethylenic unsaturation and hydrogen peroxide to ethylenic unsaturation. The optimum relative conversion into oxirane (80.4 %) and conversion of iodine (94.7 %) was achieved with ∼70 % yield at the condition of 45 degree Celsius reaction temperature, formic acid to ethylenic unsaturation mole ratio of 2.0, hydrogen peroxide to ethylenic unsaturation mole ratio of 12.0 for 2 hours of reaction time. The epoxidized linoleic acid was characterized by using Fourier transform infrared (FTIR) spectroscopy and NMR analysis. The result was also found that the formations of an epoxide and oxirane ring cleavage were both occurred at the same time if low amount of hydrogen peroxide was used. (author)

  2. Effects of partial hydrogenation, epoxidation, and hydroxylation on the fuel properties of fatty acid methyl esters

    Wadumesthrige, Kapila; Salley, Steven O.; Ng, K.Y. Simon [Department of Chemical Engineering and Materials Science, Wayne State University, 5050 Anthony Wayne Drive, Detroit, MI 48202 (United States)

    2009-10-15

    The properties of biodiesel depend on the chemical structure of individual fatty acid methyl esters (FAME). In this work the chemical structure of fatty acid chains was modified by catalytic hydrogenation, epoxidation and hydroxylation under controlled conditions. Hydrolysis of ester functionality or oxidation of fatty acid chain was not observed during these reactions. The properties of hydrogenated FAME strongly depend on the hydrogenation time. The total saturated fatty acid (SFA) percentage increased from 29.3% to 76.2% after 2 h of hydrogenation. This hydrogenated FAME showed higher oxidation stability and higher cetane number but poor cold flow properties. Formation of trans FAME was observed during hydrogenation. Both hydroxylation and epoxidation resulted in a decrease of unsaturated fatty acid methyl ester (UFA) fraction. The percentages of total unsaturated FAME decreased 39% in the epoxidation reaction and 44% in the hydroxylation reaction. The addition of hydroxyl groups to the unsaturated regions of the fatty acid chain yields biodiesel with better cold flow properties, increased lubricity and slightly increased oxidative stability. However, epoxy FAME shows some interesting properties such as higher oxidation stability, higher cetane number and acceptable cold flow properties, which met the limits of ASTM D6751 biodiesel specifications. (author)

  3. Epoxidized Vegetable Oils Plasticized Poly(lactic acid Biocomposites: Mechanical, Thermal and Morphology Properties

    Buong Woei Chieng

    2014-10-01

    Full Text Available Plasticized poly(lactic acid PLA with epoxidized vegetable oils (EVO were prepared using a melt blending method to improve the ductility of PLA. The plasticization of the PLA with EVO lowers the Tg as well as cold-crystallization temperature. The tensile properties demonstrated that the addition of EVO to PLA led to an increase of elongation at break, but a decrease of tensile modulus. Plasticized PLA showed improvement in the elongation at break by 2058% and 4060% with the addition of 5 wt % epoxidized palm oil (EPO and mixture of epoxidized palm oil and soybean oil (EPSO, respectively. An increase in the tensile strength was also observed in the plasticized PLA with 1 wt % EPO and EPSO. The use of EVO increases the mobility of the polymeric chains, thereby improving the flexibility and plastic deformation of PLA. The SEM micrograph of the plasticized PLA showed good compatible morphologies without voids resulting from good interfacial adhesion between PLA and EVO. Based on the results of this study, EVO may be used as an environmentally friendly plasticizer that can improve the overall properties of PLA.

  4. Lysophosphatidic acids are new substrates for the phosphatase domain of soluble epoxide hydrolase[S

    Oguro, Ami; Imaoka, Susumu

    2012-01-01

    Soluble epoxide hydrolase (sEH) is a bifunctional enzyme that has a C-terminus epoxide hydrolase domain and an N-terminus phosphatase domain. The endogenous substrates of epoxide hydrolase are known to be epoxyeicosatrienoic acids, but the endogenous substrates of the phosphatase activity are not well understood. In this study, to explore the substrates of sEH, we investigated the inhibition of the phosphatase activity of sEH toward 4-methylumbelliferyl phosphate by using lecithin and its hydrolyzed products. Although lecithin itself did not inhibit the phosphatase activity, the hydrolyzed lecithin significantly inhibited it, suggesting that lysophospholipid or fatty acid can inhibit it. Next, we investigated the inhibition of phosphatase activity by lysophosphatidyl choline, palmitoyl lysophosphatidic acid, monopalmitoyl glycerol, and palmitic acid. Palmitoyl lysophosphatidic acid and fatty acid efficiently inhibited phosphatase activity, suggesting that lysophosphatidic acids (LPAs) are substrates for the phosphatase activity of sEH. As expected, palmitoyl, stearoyl, oleoyl, and arachidonoyl LPAs were efficiently dephosphorylated by sEH (Km, 3–7 μM; Vmax, 150–193 nmol/min/mg). These results suggest that LPAs are substrates of sEH, which may regulate physiological functions of cells via their metabolism. PMID:22217705

  5. Lysophosphatidic acids are new substrates for the phosphatase domain of soluble epoxide hydrolase.

    Oguro, Ami; Imaoka, Susumu

    2012-03-01

    Soluble epoxide hydrolase (sEH) is a bifunctional enzyme that has a C-terminus epoxide hydrolase domain and an N-terminus phosphatase domain. The endogenous substrates of epoxide hydrolase are known to be epoxyeicosatrienoic acids, but the endogenous substrates of the phosphatase activity are not well understood. In this study, to explore the substrates of sEH, we investigated the inhibition of the phosphatase activity of sEH toward 4-methylumbelliferyl phosphate by using lecithin and its hydrolyzed products. Although lecithin itself did not inhibit the phosphatase activity, the hydrolyzed lecithin significantly inhibited it, suggesting that lysophospholipid or fatty acid can inhibit it. Next, we investigated the inhibition of phosphatase activity by lysophosphatidyl choline, palmitoyl lysophosphatidic acid, monopalmitoyl glycerol, and palmitic acid. Palmitoyl lysophosphatidic acid and fatty acid efficiently inhibited phosphatase activity, suggesting that lysophosphatidic acids (LPAs) are substrates for the phosphatase activity of sEH. As expected, palmitoyl, stearoyl, oleoyl, and arachidonoyl LPAs were efficiently dephosphorylated by sEH (Km, 3-7 μM; Vmax, 150-193 nmol/min/mg). These results suggest that LPAs are substrates of sEH, which may regulate physiological functions of cells via their metabolism.

  6. Properties of composite laminates based on basalt fibers with epoxidized vegetable oils

    Samper, M.D.; Petrucci, R.; Sanchez-Nacher, L.; Balart, R.; Kenny, J.M.

    2015-01-01

    Highlights: • New environmentally friendly composites from biobased epoxies and basalt fibers. • Improved performance with conventional silane treatment on basalt fabrics. • Composites with excellent appearance due to basalt shiny brown color. • Potential applications as substitute of glass fiber reinforced composites in engineering design. • Processing with conventional resin transfer molding (RTM) techniques. - Abstract: This paper deals with the development of polymeric materials derived from epoxidized vegetable oils which have been used in the manufacture of laminated composite materials with basalt fabrics. Epoxidized linseed oil (ELO) and epoxidized soybean oil (ESBO) were used as biobased matrices. The basalt fabrics were modified with amino-silane and glycidyl-silane to increase fiber–matrix interactions. The curing behavior of both resins was evaluated by differential scanning calorimetry (DSC) and oscillatory rheometry (OR). The evaluation of mechanical properties was made by tensile, flexural and Charpy tests. The extent of the fiber–matrix interactions among interface was evaluated by scanning electron microscopy (SEM). The obtained results revealed that surface modification of basalt fibers with glycidyl-silane clearly improves the mechanical properties of the composites. The use of the ELO resin as matrix for composite laminates improved substantially the mechanical performance compared to composites made with ESBO

  7. Comparative Study of Chemical, Mechanical, Thermal, and Barrier Properties of Poly(Lactic Acid Plasticized with Epoxidized Soybean Oil and Epoxidized Palm Oil

    Yee Bond Tee

    2015-12-01

    Full Text Available To investigate epoxidized palm oil’s (EPO potential as plasticizer for poly(lactic acid (PLA, its plasticizing effect was compared with commercialized epoxidized soybean oil (ESO. The plasticizers were respectively melt-compounded into PLA at 3, 5, 10, and 15 wt.%. As it was aimed for the blends to be characterized towards packaging appropriate for food products, they were hot-pressed into ~0.3-mm sheets, which is the approximate thickness of clamshell packaging. Fourier transform infrared spectroscopy (FTIR confirmed the plasticizers’ compatibility with PLA. At similar loadings, EPO was superior in reinforcing elongation at break (EAB, thermal, and barrier properties of PLA. The ductility of PLA was notably improved to 50.0% with addition of 3 wt.% of EPO. From thermogravimetric analysis (TGA, PLA/EPO5 improved PLA’s thermal stability, while all PLA/ESO blends reported reduced thermal stability. From differential scanning calorimetry (DSC, the increase in crystallinity and the shifts in enthalpy of fusions in all plasticized blends denoted facilitation of PLA to form thermally stable α-form crystals. The addition of EPO enabled PLA to become highly impermeable to oxygen, which can extend its potential in packaging extensive range of oxygen sensitive food.

  8. Highly selective sulfur ylide mediated asymmetric epoxidations and aziridinations using an inexpensive chiral sulfide and applications to the synthesis of quinine and quinidine (abstract)

    Arshad, M.; Illa, O.; Mcgarrigle, E.M.

    2011-01-01

    Asymmetric sulfur ylide mediated epoxidation, which is considered a complimentary method to asymmetric epoxidation of alkene has been utilized as a key step in the asymmetric total synthesis of complex cinchona alkaloids quinine and quinidine. Isothiocineole 1, which was readily available in one step from very inexpensive starting materials, is employed as a chiral sulfide to prepare the desired sulfonium salt 2. The semi-stabilised ylide derived from this salt on epoxidation with meroquinene aldehyde 3, afforded the required epoxide 4 in 81% yield and 89:11 diastereoselectivity (trans/cis). The epoxide was converted to the target quinine 5 in 73% yield over four steps in one pot. Similarly, the opposite enantiomer of isothiocineole was used to synthesise the corresponding sulfonium salt, which on reaction with meroquinene aldehyde gave epoxide in 73% yield and 84:16 diastereoselectivity (trans/cis). This epoxide was transformed to the target quinidine in 78% yield over four steps in one pot. The epoxidation reactions proceeded under reagent control with high trans selectivity. The effect of sulfide and ylide substituents on the stereochemical outcome of the epoxidation reaction is also prescribed. (author)

  9. Cryobanking of human ovarian tissue

    Ernst, Erik; Andersen, Anders Nyboe; Andersen, Claus Yding

    2014-01-01

    Cryopreservation of ovarian tissue is one way of preserving fertility in young women with a malignant disease or other disorders that require gonadotoxic treatment. The purpose of the study was to explore how many women remained interested in continued cryostorage of their ovarian tissue beyond...... an initial 5-year period. Between 1999 and 2006, a total of 201 girls and young women had one ovary cryopreserved for fertility preservation in Denmark. One hundred of these met our inclusion criteria, which included a follow-up period of at least 5 years, and were mailed a questionnaire. The response rate...... women with ovarian tissue cryobanked requested continued cryostorage after an initial period of at least 5 years. The main reason for requesting disposal was successful completion of a family....

  10. Testosterone for Poor Ovarian Responders

    Polyzos, Nikolaos P; Davis, Susan R; Drakopoulos, Panagiotis

    2016-01-01

    Testosterone, an androgen that directly binds to the androgen receptor, has been shown in previous small randomized controlled trials to increase the reproductive outcomes of poor ovarian responders. In most of these studies, transdermal testosterone in relatively high doses was administered before...... ovarian stimulation with a duration varying from 5 to 21 days. Nevertheless, the key question to be asked is whether, based on ovarian physiology and testosterone pharmacokinetics, a short course of testosterone administration of more than 10 mg could be expected to have any beneficial effect...... stages. In addition, extreme testosterone excess is not only likely to induce adverse events but has also the potential to be ineffective and even detrimental. Thus, evidence from clinical studies is not enough to either "reopen" or "close" the "androgen chapter" in poor responders, mainly because...

  11. Oophoropexy for Recurrent Ovarian Torsion

    Jennifer Hartley

    2018-01-01

    Full Text Available A 31-year-old nulliparous patient presents with a three-day history of right sided colicky abdominal pain and associated nausea. This patient has previously presented twice with right sided ovarian torsion with the background of polycystic ovaries in the last two consecutive years. Blood tests were normal. Due to previous history, there was a high index of clinical suspicion that this may be a further torsion. Therefore, the patient was taken to theatre for a diagnostic laparoscopy and a further right sided ovarian torsion was noted. At this time, oophoropexy was performed to the uterosacral ligament to prevent further torsion in order to preserve the patients’ fertility. In this article, we detail this case and also provide a discussion of ovarian torsion including risk factors, presentation, and current thoughts on management.

  12. Ovarian metastases: Computed tomographic appearances

    Megibow, A.J.; Hulnick, D.H.; Bosniak, M.A.; Balthazar, E.J.

    1985-01-01

    Computed tomographic scans of 34 patients with ovarian metastases were reviewed to assess the radiographic appearances and to correlate these with the primary neoplasms. Primary neoplasms were located in the colon (20 patients), breast (six), stomach (five), small bowel (one), bladder (one), and Wilms tumor of the kidney (one). The radiographic appearance of the metastatic lesions could be described as predominantly cystic (14 lesions), mixed (12 lesions), or solid (seven lesions). The cystic and mixed lesions tended to be larger in overall diameter than the solid. The metastases from gastric carcinoma appeared solid in four of five cases. The metastases from the other neoplasms had variable appearances simulating primary ovarian carcinoma

  13. Thrombosis of right ovarian vein

    Forner, J.; Talens, A.; Flores, M.; Mendez, M.

    2001-01-01

    Ovarian vein thrombosis is a rare postpartum complication (0.1%). It can be fatal, since it can lead to sepsis, pulmonary thromboembolisms and inferior vena cava or renal vein thrombosis. Computed tomography and magnetic resonance imaging are the techniques of choice for its diagnosis, while the value of ultrasound is limited due to its low sensitivity and specificity. We report the case of a woman who, during puerperium, developed thrombosis of right ovarian vein that presented clinical, ultrasonographic and computed tomographic features of appendicitis. We describe the radiological sings and stress the fact that this diagnosis should be suspected in puerperal women. (Author) 9 refs

  14. Polycystic ovarian syndrome management options.

    Bates, G Wright; Propst, Anthony M

    2012-12-01

    Polycystic ovarian syndrome (PCOS) is a disorder of androgen excess and ovarian dysfunction. Hirsutism and elevated free testosterone levels are the most consistent signs of the androgen excess. Irregular, infrequent, or absent menses and infertility are symptoms of ovulatory dysfunction. Obesity is also a feature of this syndrome and contributes to associated metabolic abnormalities. Lifestyle modification should be the first treatment and is effective in reducing the signs and symptoms. The ovulatory infertility associated with PCOS can be overcome in most cases with oral (clomiphene citrate or letrozole) or injectable (gonadotropins) agents. Surgical intervention is reserved for cases resistant to medical management. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Polycystic ovarian disease.

    Raj, S G; Talbert, L M

    1984-01-01

    Polycystic ovarian disease (PCOD) was first described as a single disease by Stein and Leventhal in 1935, but now has been separated into several distinct entities, comprising a symptom complex. The most frequent presenting symptoms associated with PCOD are obesity, hirsutism, amenorrhea or anovulation, dysfunctional uterine bleeding, irregular menses, and infertility. The common finding of hirsutism in PCOD patients is a reflection of the hyperandrogenism resulting from elevation of all the androgens, including testosterone, androstenediol, dehydroepiandrostrone sulfate (DHEA-S), and androstenedione. Some patients with all the clinical features of PCOD can be shown, through appropriate testing, to have an attenuated form of classic congenital adrenal hyperplasia (CAH). Serum follicle stimulating hormone (FSH) levels are usually low or in the normal range, and serum luteinizing hormone (LH) levels are usually elevated in patients with PCOD, resulting in an altered LH/FSH ratio. Treatment for PCOD must be based on the needs and desires of the individual patient, and on the pathophysiology of the patient's particular abnormalities. When pregnancy is desired, ovulation induction with clomiphene is indicated. Clomiphene is a weak estrogen that induces a transient rise in serum LH and FSH, followed by a gonadotropic pattern similar to normal cycles. A 72% ovulation rate and a 41.8% conception rate have been reported after treatment with clomiphene. In patients who do not respond to clomiphene, or clomiphene with added human chorionic gonadotropin (hCG), human menopausal gonadotropin (hMG) can be used to induce ovulation, but the patient should be closely monitored for multiple ovulation, multiple pregnancy, or hyperstimulation syndrome. For patients not interested in conception, regular menstrual cyclicity can be restored and hyperandrogenism reduced with oral contraceptives (OCs).

  16. Immunological comparison of ovarian and colonic CEA

    Burtin, P.; Gendron, M.C.; Maunoury, M.T.; Lamerz, R.; Schnabel, G.

    1982-01-01

    Ovarian and colonic CEA were compared immunologically by means of antisera prepared against each of them. CEAs of both origins were found identical by immunodiffusion methods. In radioimmunological experiments, slight differences were observed between some but not all ovarian CEAs and colonic CEAs and also between different preparations of colonic CEA: no organ specificity of ovarian CEA could be demonstrated. Finally, CEA level was measured in 41 sera of patients with ovarian carcinoma by two radioimmunoassays, one using colonic CEA as tracer and standard and anti-colonic CEA serum, the other using ovarian CEA and anti-ovarian CEA serum: the values given by the two assays were highly correlated (rsub(s) = 0.8107), meaning that an organ specific assay for ovarian CEA is not needed. (Auth.)

  17. Palliative Care in Improving Quality of Life and Symptoms in Patients With Stage III-IV Pancreatic or Ovarian Cancer

    2014-12-18

    Recurrent Ovarian Epithelial Cancer; Recurrent Ovarian Germ Cell Tumor; Recurrent Pancreatic Cancer; Stage III Pancreatic Cancer; Stage IIIA Ovarian Epithelial Cancer; Stage IIIA Ovarian Germ Cell Tumor; Stage IIIB Ovarian Epithelial Cancer; Stage IIIB Ovarian Germ Cell Tumor; Stage IIIC Ovarian Epithelial Cancer; Stage IIIC Ovarian Germ Cell Tumor; Stage IV Ovarian Epithelial Cancer; Stage IV Ovarian Germ Cell Tumor; Stage IV Pancreatic Cancer

  18. Formation of glutathione conjugates by reactive metabolites of vinylidene chloride in microsomes and isolated hepatocytes

    Liebler, D.C.; Meredith, M.J.; Guengerich, F.P.

    1985-01-01

    Oxidation of the vinyl halide carcinogen and hepatotoxin vinylidene chloride (VDC) by microsomal cytochrome P-450 yields 2,2-dichloroacetaldehyde, 2-chloroacetyl chloride, 2-chloroacetic acid, and 1,1-dichloroethylene oxide. The roles of these metabolites in covalent modification of proteins and reduced glutathione (GSH) were examined. 2-Chloroacetyl chloride reacted with model thiols at least 10(3)-fold faster than did 1,1-dichloroethylene oxide and at least 10(5)-fold faster than did 2,2-dichloroacetaldehyde or 2-chloroacetic acid. Microsomal covalent binding of [ 14 C]VDC was inhibited by GSH but not by lysine, suggesting that protein thiols, rather than amino groups, are major targets. Liver microsomes catalyzed the formation of three GSH:VDC metabolite conjugates, identified as S-(2,2-dichloro-1-hydroxy)ethylglutathione, 2-(S-glutathionyl)acetate, and S-(2-glutathionyl)acetylglutathione, a novel conjugate containing both stable (thioether) and labile (thioester) linkages. The latter two conjugates also were formed in isolated rat hepatocytes and measurable amounts of 2-(S-glutathionyl)acetate were released into the incubation medium. Both 2-(S-glutathionyl)acetate and S-(2-glutathionyl)acetylglutathione were formed with [ 35 S]GSH added to the hepatic medium, indicating that reactive VDC metabolites are capable of crossing the plasma membrane to react with extracellular targets. Unlabeled S-(2-glutathionyl)-acetylglutathione underwent carbonyl substitution with added [ 35 S]GSH, suggesting that this conjugate may participate in modification of protein thiols. This conjugate also underwent hydrolysis with a half-life of approximately 3 hr. GSH:VDC metabolite conjugates may serve as accessible models for labile covalent adducts formed between VDC metabolites and protein thiols

  19. Reductive metabolism of oxymatrine is catalyzed by microsomal CYP3A4

    Liu W

    2015-10-01

    Full Text Available Wenqin Liu,1,2,* Jian Shi,1,2,* Lijun Zhu,2 Lingna Dong,1 Feifei Luo,2 Min Zhao,2 Ying Wang,2 Ming Hu,2,3 Linlin Lu,2 Zhongqiu Liu1,2 1Department of Pharmaceutics, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, Guangdong, People’s Republic of China; 2International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People’s Republic of China; 3Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX, USA *These authors contributed equally to this work Abstract: Oxymatrine (OMT is a pharmacologically active primary quinolizidine alkaloid with various beneficial and toxic effects. It is confirmed that, after oral administration, OMT could be transformed to the more toxic metabolite matrine (MT, and this process may be through the reduction reaction, but the study on the characteristics of this transformation is limited. The aim of this study was to investigate the characteristics of this transformation of OMT in the human liver microsomes (HLMs and human intestinal microsomes (HIMs and the cytochrome P450 (CYP isoforms involved in this transformation. The current studies demonstrated that OMT could be metabolized to MT rapidly in HLMs and HIMs and CYP3A4 greatly contributed to this transformation. All HLMs, HIMs, and CYP3A4 isoform mediated reduction reaction followed typical biphasic kinetic model, and Km, Vmax, and CL were significant higher in HLMs than those in HIMs. Importantly, different oxygen contents could significantly affect the metabolism of OMT, and with the oxygen content decreased, the formation of metabolite was increased, suggesting this transformation was very likely a reduction reaction. Results of this in vitro study elucidated the metabolic pathways and characteristics of metabolism of OMT to MT and would provide a theoretical basis and guidance for the safe application of OMT

  20. Metabolism of ethylbenzene by human liver microsomes and recombinant human cytochrome P450s (CYP).

    Sams, Craig; Loizou, George D; Cocker, John; Lennard, Martin S

    2004-03-07

    The enzyme kinetics of the initial hydroxylation of ethylbenzene to form 1-phenylethanol were determined in human liver microsomes. The individual cytochrome P450 (CYP) forms catalysing this reaction were identified using selective inhibitors and recombinant preparations of hepatic CYPs. Production of 1-phenylethanol in hepatic microsomes exhibited biphasic kinetics with a high affinity, low Km, component (mean Km = 8 microM; V(max) = 689 pmol/min/mg protein; n = 6 livers) and a low affinity, high Km, component (Km = 391 microM; V(max) = 3039 pmol/min/mg protein; n = 6). The high-affinity component was inhibited 79%-95% (mean 86%) by diethyldithiocarbamate, and recombinant CYP2E1 was shown to metabolise ethylbenzene with low Km (35 microM), but also low (max) (7 pmol/min/pmol P450), indicating that this isoform catalysed the high-affinity component. Recombinant CYP1A2 and CYP2B6 exhibited high V(max) (88 and 71 pmol/min/pmol P450, respectively) and high Km (502 and 219 microM, respectively), suggesting their involvement in catalysing the low-affinity component. This study has demonstrated that CYP2E1 is the major enzyme responsible for high-affinity side chain hydroxylation of ethylbenzene in human liver microsomes. Activity of this enzyme in the population is highly variable due to induction or inhibition by physiological factors, chemicals in the diet or some pharmaceuticals. This variability can be incorporated into the risk assessment process to improve the setting of occupational exposure limits and guidance values for biological monitoring.

  1. Binding of bilirubin and its structural analogues to hepatic microsomal bilirubin UDP glucuronyltransferase

    Vanstapel, F.; Blanckaert, N.

    1987-01-01

    Hepatic glucuronidation of the asymmetrical natural bilirubin molecule results in formation of two different positional isomers, bilirubin C-8 monoglucuronide and bilirubin C-12 monoglucuronide. In view of the existence of multiple isoforms of UDPglucuronyltransferase, which is the microsomal enzyme system responsible for bilirubin esterification, the authors performed kinetic analysis of microsomal glucuronidation of bilirubin and a number of its structural congeners to determine whether synthesis of the two monoglucuronide isomers involved two distinct substrate-binding sites or reflected two different modes of binding to a single catalytic site. Both isomers were found in all tested species (man, rat, guinea pig, sheep), but there were marked species differences in the C-8/C-12 ratio of monoglucuronide found in bile or formed by liver microsomes. Correspondence between in vivo and in vitro results for such regioselectivity of glucuronidation was excellent in each species. On the basis of these results of kinetic analysis of bilirubin esterification at variable pigment substrate concentrations and inhibition studies with alternative substrates, the authors postulate that both natural monoglucuronide isomers are synthesized at a single binding site. Possible mechanisms responsible for the markedly regioselective esterification of bilirubin by rat and sheep liver were investigated by study of glucuronidation of selected structural analgoues of the pigment. Collectively, their findings suggest that the molecular from(s) of bilirubin able to engage in catalytically effective binding to UDPglucuronyltransferase does (do) not correspond with intramolecularly hydrogen-bonded conformers and that the nature of the β-substituents of the outer pyrromethenone rings is a key determinant of glucuronidation rate

  2. Metabolism of ginger component [6]-shogaol in liver microsomes from mouse, rat, dog, monkey, and human.

    Chen, Huadong; Soroka, Dominique; Zhu, Yingdong; Sang, Shengmin

    2013-05-01

    There are limited data on the metabolism of [6]-shogaol (6S), a major bioactive component of ginger. This study demonstrates metabolism of 6S in liver microsomes from mouse, rat, dog, monkey, and human. The in vitro metabolism of 6S was compared among five species using liver microsomes from mouse, rat, dog, monkey, and human. Following incubations with 6S, three major reductive metabolites 1-(4'-hydroxy-3'-methoxyphenyl)-4-decen-3-ol (M6), 1-(4'-hydroxy-3'-methoxyphenyl)-decan-3-ol (M9), and 1-(4'-hydroxy-3'-methoxyphenyl)-decan-3-one (M11), as well as two new oxidative metabolites (1E,4E)-1-(4'-hydroxy-3'-methoxyphenyl)-deca-1,4-dien-3-one (M14) and (E)-1-(4'-hydroxy-3'-methoxyphenyl)-dec-1-en-3-one (M15) were found in all species. The kinetic parameters of M6 in liver microsomes from each respective species were quantified using Michaelis-Menten theory. A broad CYP-450 inhibitor, 1-aminobenzotriazole, precluded the formation of oxidative metabolites, M14 and M15, and 18β-glycyrrhetinic acid, an aldo-keto reductase inhibitor, eradicated the formation of the reductive metabolites M6, M9, and M11 in all species. Metabolites M14 and M15 were tested for cancer cell growth inhibition and induction of apoptosis and both showed substantial activity, with M14 displaying greater potency than 6S. We conclude that 6S is metabolized extensively in mammalian species mouse, rat, dog, monkey, and human, and that there are significant interspecies differences to consider when planning preclinical trials toward 6S chemoprevention. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Isolation and structural elucidation of tiamulin metabolites formed in liver microsomes of pigs

    Lykkeberg, Anne Kruse; Cornett, Claus; Halling-Sørensen, Bent

    2006-01-01

    Although the antimicrobial tiamulin is extensively metabolized in pigs, the metabolism is not well investigated. In this work the NADPH dependent metabolism of tiamulin in liver microsomes from pigs has been studied. The tiamulin metabolites formed in the incubations were analysed using LC-MS, an...... 20% of tiamulin was deethylated, 10% was hydroxylated in the 2beta-position and 7% was hydroxylated in the 8alpha-position. About 40% of tiamulin was metabolized during the incubation conditions used. The protein precipitation in the incubations was performed using perchloric acid...

  4. Environmentally persistent free radicals inhibit cytochrome P450 activity in rat liver microsomes

    Reed, James R., E-mail: rreed@lsuhsc.edu [Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States); The Stanley S. Scott Cancer Center, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States); Cawley, George F.; Ardoin, Taylor G. [Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States); The Stanley S. Scott Cancer Center, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States); Dellinger, Barry; Lomnicki, Slawomir M.; Hasan, Farhana; Kiruri, Lucy W. [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States); Backes, Wayne L. [Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States); The Stanley S. Scott Cancer Center, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States)

    2014-06-01

    Combustion processes generate particulate matter that affects human health. When incineration fuels include components that are highly enriched in aromatic hydrocarbons (especially halogenated varieties) and redox-active metals, ultrafine particulate matter containing air-stable, environmentally persistent free radicals (EPFRs) is generated. The exposure to fine EPFRs (less than 2.5 μm in diameter) has been shown to negatively influence pulmonary and cardiovascular functions in living organisms. The goal of this study was to determine if these EPFRs have a direct effect on cytochrome P450 function. This was accomplished by direct addition of the EPFRs to rat liver microsomal preparations and measurement of several P450 activities using form-selective substrates. The EPFRs used in this study were formed by heating vapors from an organic compound (either monochlorophenol (MCP230) or 1,2-dichlorobenzene (DCB230)) and 5% copper oxide supported on silica (approximately 0.2 μm in diameter) to 230 °C under vacuum. Both types of EPFRs (but not silica, physisorbed silica, or silica impregnated with copper oxide) dramatically inhibited the activities of CYP1A, CYP2B, CYP2E1, CYP2D2 and CYP3A when incubated at concentrations less than 0.1 mg/ml with microsomes and NADPH. Interestingly, at the same concentrations, the EPFRs did not inhibit HO-1 activity or the reduction of cytochrome c by NADPH-cytochrome P450 reductase. CYP2D2-selective metabolism by rat liver microsomes was examined in more detail. The inhibition of CYP2D2-selective metabolism by both DCB230- and MCP230-EPFRs appeared to be largely noncompetitive and was attenuated in the presence of catalase suggesting that reactive oxygen species may be involved in the mechanism of inhibition. - Highlights: • Combustion of organic pollutants generates long-lived particulate radicals (EPFRs). • EPFRs inhibit metabolism by all cytochromes P450 tested in rat liver microsomes. • EPFR-mediated inhibition is related to

  5. Environmentally persistent free radicals inhibit cytochrome P450 activity in rat liver microsomes

    Reed, James R.; Cawley, George F.; Ardoin, Taylor G.; Dellinger, Barry; Lomnicki, Slawomir M.; Hasan, Farhana; Kiruri, Lucy W.; Backes, Wayne L.

    2014-01-01

    Combustion processes generate particulate matter that affects human health. When incineration fuels include components that are highly enriched in aromatic hydrocarbons (especially halogenated varieties) and redox-active metals, ultrafine particulate matter containing air-stable, environmentally persistent free radicals (EPFRs) is generated. The exposure to fine EPFRs (less than 2.5 μm in diameter) has been shown to negatively influence pulmonary and cardiovascular functions in living organisms. The goal of this study was to determine if these EPFRs have a direct effect on cytochrome P450 function. This was accomplished by direct addition of the EPFRs to rat liver microsomal preparations and measurement of several P450 activities using form-selective substrates. The EPFRs used in this study were formed by heating vapors from an organic compound (either monochlorophenol (MCP230) or 1,2-dichlorobenzene (DCB230)) and 5% copper oxide supported on silica (approximately 0.2 μm in diameter) to 230 °C under vacuum. Both types of EPFRs (but not silica, physisorbed silica, or silica impregnated with copper oxide) dramatically inhibited the activities of CYP1A, CYP2B, CYP2E1, CYP2D2 and CYP3A when incubated at concentrations less than 0.1 mg/ml with microsomes and NADPH. Interestingly, at the same concentrations, the EPFRs did not inhibit HO-1 activity or the reduction of cytochrome c by NADPH-cytochrome P450 reductase. CYP2D2-selective metabolism by rat liver microsomes was examined in more detail. The inhibition of CYP2D2-selective metabolism by both DCB230- and MCP230-EPFRs appeared to be largely noncompetitive and was attenuated in the presence of catalase suggesting that reactive oxygen species may be involved in the mechanism of inhibition. - Highlights: • Combustion of organic pollutants generates long-lived particulate radicals (EPFRs). • EPFRs inhibit metabolism by all cytochromes P450 tested in rat liver microsomes. • EPFR-mediated inhibition is related to

  6. Lichen planus, liver kidney microsomal (LKM1) antibodies and hepatitis C virus antibodies.

    Divano, M C; Parodi, A; Rebora, A

    1992-01-01

    No anti-liver kidney microsomal (LKM1) antibodies were detected in 46 patients with LP, 16 of whom had also a chronic liver disease (CLD). In contrast, anti-hepatitis C virus (HCV) antibodies were found in 10% of patients with LP and in 50% of those with LP and CLD. Anti-HCV antibodies may be considered as a false-positive reaction in 56% of cases, especially when anti-LKM1 antibodies are present. Our findings do not support such a hypothesis, but suggest that CLD in LP patients is, at least in Italy, mostly a postviral chronic active hepatitis.

  7. In-Situ Generated Graphene as the Catalytic Site for Visible-Light Mediated Ethylene Epoxidation on AG Nanocatalysts

    Zhang, Xueqiang Alex; Jain, Prashant

    2017-06-01

    Despite the harsh conditions for chemical conversion, ethylene oxide produced from ethylene epoxidation on Ag-based heterogeneous catalyst constitutes one of the largest volume chemicals in chemical industry. Recently, photocatalytic epoxidation of ethylene over plasmonic Ag nanoparticles enables the chemical conversion under significantly decreased temperature and ambient pressure conditions. Yet a detailed understanding of the photocatalytic process at the reactant/catalyst interface is under debate. Surface enhanced Raman spectroscopy (SERS) is a powerful vibrational spectroscopy technique that enables the localized detection of rare and/or transient chemical species with high sensitivity under in situ and ambient conditions. Using SERS, we are able to monitor at individual sites of an Ag nanocatalyst the visible-light-mediated adsorption and epoxidation of ethylene. From detected intermediates, we find that the primary step in the photoepoxidation is the transient formation of graphene catalyzed by the Ag surface. Density functional theory (DFT) simulations that model the observed SERS spectra suggest that the defective edge sites of the graphene formed on Ag constitute the active site for C2H4 adsorption and epoxidation. Further studies with pre-formed graphene/Ag catalyst composites confirm the indispensable role of graphene in visible-light-mediated ethylene epoxidation. Carbon is often thought to be either an innocent support or a poison for metallic catalysts; however our studies reveal a surprising role for crystalline carbon layers as potential co-catalysts.

  8. Ovarian stimulation and embryo quality

    Baart, Esther; Macklon, Nick S.; Fauser, Bart J. C. M.

    To Study the effects of different ovarian stimulation approaches on oocyte and embryo quality, it is imperative to assess embryo quality with a reliable and objective method. Embryos rated as high quality by standardized morphological assessment are associated with higher implantation and pregnancy

  9. CA125 in ovarian cancer

    Duffy, M J; Bonfrer, J M; Kulpa, J

    2005-01-01

    women, however, may aid the differentiation of benign and malignant pelvic masses. Serial levels during chemotherapy for ovarian cancer are useful for assessing response to treatment. Although serial monitoring following initial chemotherapy can lead to the early detection of recurrent disease...

  10. Ovarian Cancer Risk Prediction Models

    Developing statistical models that estimate the probability of developing ovarian cancer over a defined period of time will help clinicians identify individuals at higher risk of specific cancers, allowing for earlier or more frequent screening and counseling of behavioral changes to decrease risk.

  11. Ovarian cancer and body size

    Mosgaard, Berit Jul

    2012-01-01

    Only about half the studies that have collected information on the relevance of women's height and body mass index to their risk of developing ovarian cancer have published their results, and findings are inconsistent. Here, we bring together the worldwide evidence, published and unpublished...

  12. Ultrasound in evaluating ovarian reserve

    Eman Ahmaed Shawky Sabek

    2015-12-01

    Full Text Available The objective of this study was to compare the diagnostic accuracy of transvaginal ultrasound (TVS, as a less invasive technique instead of hormonal assay to evaluate the ovarian reserve. This study included fifty-five females with breast cancer and we compared the ovarian reserve for these patients by hormonal assay through measuring the serum AntiMullerian Hormone (AMH level and follicular stimulating hormone (FSH level before and after chemotherapy, and by transvaginal ultrasound through the ovarian volume (OV calculation and counting the Antral follicles (AFC before and after chemotherapy treatment. There was decline in the AntiMullerian Hormone level after chemotherapy by 27 ± 11.19% and decrease in the Antral follicle counts by 21 ± 13.43%. In conclusion there was strong relation between AMH level and AFC which makes the use of transvaginal ultrasound is a reliable alternative method to the hormonal assay to detect the ovarian reserve.

  13. Ovarian irradiation in recurrent endometriosis

    Kochbati, L.; Chaari, N.; Besbes, M.; Maalej, M.; Neji, K.; Ben Amara, F.; Ben Romdhane, N.K.

    2005-01-01

    We describe a case of a young woman with a history of an aplastic anaemia in which pelvic radiotherapy was used successfully in the management of a recurrent and inoperable endometriosis. The use of therapeutic pelvic or ovarian irradiation in endometriosis may be considered, when surgical and medical treatments have been exhausted and have failed. (authors)

  14. Asymmetric aminolytic kinetic resolution of racemic epoxides using recyclable chiral polymeric Co(III)-salen complexes: a protocol for total utilization of racemic epoxide in the synthesis of (R)-Naftopidil and (S)-Propranolol.

    Kumar, Manish; Kureshy, Rukhsana I; Shah, Arpan K; Das, Anjan; Khan, Noor-ul H; Abdi, Sayed H R; Bajaj, Hari C

    2013-09-20

    Chiral polymeric Co(III) salen complexes with chiral ((R)/(S)-BINOL, diethyl tartrate) and achiral (piperazine and trigol) linkers with varying stereogenic centers were synthesized for the first time and used as catalysts for aminolytic kinetic resolution (AKR) of a variety of terminal epoxides and glycidyl ethers to get enantio-pure epoxides (ee, 99%) and N-protected β-amino alcohols (ee, 99%) with quantitative yield in 16 h at RT under optimized reaction conditions. This protocol was also used for the synthesis of two enantiomerically pure drug molecules (R)-Naftopidil (α1-blocker) and (S)-Propranolol (β-blocker) as a key step via AKR of single racemic naphthylglycidyl ether with Boc-protected isoproylamine with 100% epoxide utilization at 1 g level. The catalyst 1 was successfully recycled for a number of times.

  15. Cytochrome b5 and epoxide hydrolase contribute to benzo[a]pyrene-DNA adduct formation catalyzed by cytochrome P450 1A1 under low NADPH:P450 oxidoreductase conditions

    Stiborová, Marie; Moserová, Michaela; Černá, Věra; Indra, Radek; Dračínský, Martin; Šulc, Miroslav; Henderson, Colin J.; Wolf, C. Roland; Schmeiser, Heinz H.; Phillips, David H.; Frei, Eva; Arlt, Volker M.

    2014-01-01

    In previous studies we had administered benzo[a]pyrene (BaP) to genetically engineered mice (HRN) which do not express NADPH:cytochrome P450 oxidoreductase (POR) in hepatocytes and observed higher DNA adduct levels in livers of these mice than in wild-type mice. To elucidate the reason for this unexpected finding we have used two different settings for in vitro incubations; hepatic microsomes from control and BaP-pretreated HRN mice and reconstituted systems with cytochrome P450 1A1 (CYP1A1), POR, cytochrome b 5 , and epoxide hydrolase (mEH) in different ratios. In microsomes from BaP-pretreated mice, in which Cyp1a1 was induced, higher levels of BaP metabolites were formed, mainly of BaP-7,8-dihydrodiol. At a low POR:CYP1A1 ratio of 0.05:1 in the reconstituted system, the amounts of BaP diones and BaP-9-ol formed were essentially the same as at an equimolar ratio, but formation of BaP-3-ol was ∼1.6-fold higher. Only after addition of mEH were BaP dihydrodiols found. Two BaP-DNA adducts were formed in the presence of mEH, but only one when CYP1A1 and POR were present alone. At a ratio of POR:CYP1A1 of 0.05:1, addition of cytochrome b 5 increased CYP1A1-mediated BaP oxidation to most of its metabolites indicating that cytochrome b 5 participates in the electron transfer from NADPH to CYP1A1 required for enzyme activity of this CYP. BaP-9-ol was formed even by CYP1A1 reconstituted with cytochrome b 5 without POR. Our results suggest that in livers of HRN mice Cyp1a1, cytochrome b 5 and mEH can effectively activate BaP to DNA binding species, even in the presence of very low amounts of POR

  16. Activation and detoxification metabolism of urban air pollutants 2-nitrobenzanthrone and carcinogenic 3-nitrobenzanthrone by rat and mouse hepatic microsomes.

    Stiborova, Marie; Cechova, Tereza; Borek-Dohalska, Lucie; Moserova, Michaela; Frei, Eva; Schmeiser, Heinz H; Paca, Jan; Arlt, Volker M

    2012-01-01

    2-Nitrobenzanthrone (2-NBA) has recently been detected in ambient air particulate matter. Its isomer 3-nitrobenzanthrone (3-NBA) is a potent mutagen and suspected human carcinogen identified in diesel exhaust. Understanding which enzymes are involved in metabolism of these toxicants is important in the assessment of individual susceptibility. Here, metabolism of 2-NBA and 3-NBA by rat and mouse hepatic microsomes containing cytochromes P450 (CYPs), their reductase (NADPH:CYP reductase), and NADH:cytochrome b5 reductase was investigated under anaerobic and aerobic conditions. In addition, using the same microsomal systems, 2-NBA and 3-NBA were evaluated to be enzymatically activated under anaerobic conditions to species generating 2-NBA- and 3-NBA-derived DNA adducts. High performance liquid chromatography (HPLC) with ultraviolet (UV) detection was employed for the separation and characterization of 2-NBA and 3-NBA metabolites formed by hepatic microsomes of rats and mice under the anaerobic and aerobic conditions. Microsomal systems isolated from the liver of the control (untreated) rats and rats pretreated with Sudan I, β-naphthoflavone (β-NF), phenobarbital (PB), ethanol and pregnenolon 16α-carbonitrile (PCN), the inducers of cytochromes P450 (CYP) 1A1, 1A1/2, 2B, 2E1 and 3A, respectively, were used in this study. Microsomes of mouse models, a control mouse line (wild-type, WT) and Hepatic Cytochrome P450 Reductase Null (HRN) mice with deleted gene of NADPH:CYP reductase in the liver, thus absenting this enzyme in their livers, were also employed. To detect and quantify the 2-NBA- and 3-NBA-derived DNA adducts, the 32P postlabeling technique was used. Both reductive metabolite of 3-NBA, 3-aminobenzanthrone (3-ABA), found to be formed predominantly under the anaerobic conditions, and two 3-NBA oxidative metabolites, whose structures have not yet been investigated, were formed by several microsomal systems used in the study. Whereas a 3-NBA reductive metabolite

  17. Chromatographic separation of piracetam and its metabolite in a mixture of microsomal preparations, followed by an MS/MS analysis.

    Sahu, Kapendra; Siddiqui, Anees A; Shaharyar, Mohammad; Ahmad, Niyaz; Anwar, Mohammad; Ahmad, Farhan J

    2013-07-01

    A rapid bioanalytical method was evaluated for the simultaneous determination of piracetam and its metabolite (M1) in human microsomal preparations by fast ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS). In addition, a validated method of M1 in rat plasma was developed and successfully applied on pharmacokinetic studies. The present study was carried out to determine the metabolic pathways of piracetam for phase I metabolism and used cytochrome P450 isoforms responsible for the piracetam metabolism in human liver microsomes (HLMs). While additional potential metabolites of piracetam were suggested by computer-modeling. The resulting 2-(2-oxopyrrolidin-1-yl) acetic acid was the sole metabolite detected after the microsomal treatment. The amide hydrolysis mainly underwent to form a metabolite i.e., 2-(2-oxopyrrolidin-1-yl) acetic acid (M1). Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  18. Ovarian cysts on prenatal MRI

    Nemec, Ursula; Nemec, Stefan F.; Bettelheim, Dieter; Brugger, Peter C.; Horcher, Ernst; Schöpf, Veronika; Graham, John M.; Rimoin, David L.; Weber, Michael; Prayer, Daniela

    2012-01-01

    Objective: Ovarian cysts are the most frequently encountered intra-abdominal masses in females in utero. They may, at times, require perinatal intervention. Using magnetic resonance imaging (MRI) as an adjunct to ultrasonography (US) in prenatal diagnosis, we sought to demonstrate the ability to visualize ovarian cysts on prenatal MRI. Materials and methods: This retrospective study included 17 fetal MRI scans from 16 female fetuses (23–37 gestational weeks) with an MRI diagnosis of ovarian cysts after suspicious US findings. A multiplanar MRI protocol was applied to image and to characterize the cysts. The US and MRI findings were compared, and the prenatal findings were compared with postnatal imaging findings or histopathology. Results: Simple ovarian cysts were found in 10/16 cases and complex cysts in 7/16 cases, including one case with both. In 11/16 (69%) cases, US and MRI diagnoses were in agreement, and, in 5/16 (31%) cases, MRI specified or expanded the US diagnosis. In 6/16 cases, postnatal US showed that the cysts spontaneously resolved or decreased in size, and in 1/16 cases, postnatal imaging confirmed a hemorrhagic cyst. In 4/16 cases, the prenatal diagnoses were confirmed by surgery/histopathology, and for the rest, postnatal correlation was not available. Conclusion: Our results illustrate the MRI visualization of ovarian cysts in utero. In most cases, MRI will confirm the US diagnosis. In certain cases, MRI may provide further diagnostic information, additional to US, which is the standard technique for diagnosis, monitoring, and treatment planning.

  19. Ovarian cysts on prenatal MRI

    Nemec, Ursula [Department of Radiology, Division of Neuroradiology and Musculoskeletal Radiology, Medical University Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Nemec, Stefan F., E-mail: stefan.nemec@meduniwien.ac.at [Department of Radiology, Division of Neuroradiology and Musculoskeletal Radiology, Medical University Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Medical Genetics Institute, Cedars Sinai Medical Center, 8700 Beverly Boulevard, PACT Suite 400, Los Angeles, CA 90048 (United States); Bettelheim, Dieter [Department of Obstetrics and Gynaecology, Division of Prenatal Diagnosis and Therapy, Medical University Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Brugger, Peter C. [Center of Anatomy and Cell Biology, Integrative Morphology Group, Medical University Vienna, Waehringerstrasse 13, A-1090 Vienna (Austria); Horcher, Ernst [Department of Pediatric Surgery, Medical University Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Schoepf, Veronika [Department of Radiology, Division of Neuroradiology and Musculoskeletal Radiology, Medical University Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Graham, John M.; Rimoin, David L. [Medical Genetics Institute, Cedars Sinai Medical Center, 8700 Beverly Boulevard, PACT Suite 400, Los Angeles, CA 90048 (United States); Weber, Michael; Prayer, Daniela [Department of Radiology, Division of Neuroradiology and Musculoskeletal Radiology, Medical University Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria)

    2012-08-15

    Objective: Ovarian cysts are the most frequently encountered intra-abdominal masses in females in utero. They may, at times, require perinatal intervention. Using magnetic resonance imaging (MRI) as an adjunct to ultrasonography (US) in prenatal diagnosis, we sought to demonstrate the ability to visualize ovarian cysts on prenatal MRI. Materials and methods: This retrospective study included 17 fetal MRI scans from 16 female fetuses (23-37 gestational weeks) with an MRI diagnosis of ovarian cysts after suspicious US findings. A multiplanar MRI protocol was applied to image and to characterize the cysts. The US and MRI findings were compared, and the prenatal findings were compared with postnatal imaging findings or histopathology. Results: Simple ovarian cysts were found in 10/16 cases and complex cysts in 7/16 cases, including one case with both. In 11/16 (69%) cases, US and MRI diagnoses were in agreement, and, in 5/16 (31%) cases, MRI specified or expanded the US diagnosis. In 6/16 cases, postnatal US showed that the cysts spontaneously resolved or decreased in size, and in 1/16 cases, postnatal imaging confirmed a hemorrhagic cyst. In 4/16 cases, the prenatal diagnoses were confirmed by surgery/histopathology, and for the rest, postnatal correlation was not available. Conclusion: Our results illustrate the MRI visualization of ovarian cysts in utero. In most cases, MRI will confirm the US diagnosis. In certain cases, MRI may provide further diagnostic information, additional to US, which is the standard technique for diagnosis, monitoring, and treatment planning.

  20. Selective Propene Epoxidation on Immobilized Au6-10 Clusters: The Effect of Hydrogen and Water on Activity and Selectivity

    Lee, Sungsik; Molina, Luis M.; López, María J.

    2009-01-01

    Epoxidation made easy: Subnanometer gold clusters immobilized on amorphous alumina result in a highly active and selective catalyst for propene epoxidation. The highest selectivity is found for gas mixtures involving oxygen and water, thus avoiding the use of hydrogen. Ab initio DFT calculations ...

  1. Changes in ovarian reserve and ovarian blood flow in patients with polycystic ovary syndrome following laparoscopic ovarian drilling.

    Kamal, Nasser; Sanad, Zakaria; Elkelani, Osama; Rezk, Mohamed; Shawky, Mohamed; Sharaf, Abd-Elbar

    2018-04-10

    This prospective cohort study was conducted on 80 patients with clomiphene citrate (CC)-resistant polycystic ovary syndrome undergoing laparoscopic ovarian drilling (LOD). Pre- and post-LOD ovarian reserve parameters (anti-Mullerian hormone: AMH, ovarian volume: OV, and antral follicle count: AFC) and ovarian stromal blood flow indices (Vascularization index: VI, flow index: FI, and vascularization flow index: VFI) were measured to explore the effect of LOD and to find out the correlation between serum AMH and different clinical, hormonal, and ultrasonic variables. There was a highly significant reduction of the serum AMH (p ovarian reserve parameters (AMH, OV and AFC) and ovarian stromal blood flow indices (VI, FI and VFI) with no observed correlation between AMH levels and Doppler indices.

  2. A Bimetallic Aluminium(Salphen) Complex for the Synthesis of Cyclic Carbonates from Epoxides and Carbon Dioxide.

    Wu, Xiao; North, Michael

    2017-01-10

    A bimetallic aluminium(salphen) complex is reported as a sustainable, efficient and inexpensive catalyst for the synthesis of cyclic carbonates from epoxides and carbon dioxide. In the presence of this complex and tetrabutylammonium bromide, terminal and internal epoxides reacted at 50 °C and 10 bar carbon dioxide pressure to afford their corresponding cyclic carbonates in yields of 50-94 % and 30-71 % for terminal and internal cyclic carbonates, respectively. Mechanistic studies using deuterated epoxides and an analogous monometallic aluminium(salphen) chloride complex support a mechanism for catalysis by the bimetallic complex, which involves intramolecular cooperative catalysis between the two aluminium centres. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Photochemical epoxidation of olefins by visible light in a redox system involving Sb(V) tetraphenylporphyrin and water

    Inoue, Haruo; Hida, Mitsuhiko (Tokyo Metropolitan Univ. (Japan))

    1989-03-25

    The authors explore electron donors from the viewpoint of solar energy storage. Much attention has been focused on how a water molecule can be incorporated into electron donor system. In this paper, the authors describe a photochemical epoxidation of alkene sensitized by Sb(V)-, P(V)-, Sn(IV)-, Ge(IV)- tetraphenylporphyrin (TPP) with higher oxidation potential than 1.0 Volts vs. NHE in redox systems with a water molecule as an electron donor. The water molecule acts as an electron donor, and alkene acts as an oxygen atom acceptor in this photoredox system. Epoxidation of alkenes usually requires strong oxidizing agents either by the thermal or photochemical method. This is the first example of the photochemical epoxide formation from alkene and water without any strong oxidizing agent. 1 fig.

  4. Neurotoxicity and low paclitaxel clearance associated with concomitant clopidogrel therapy in a 60 year old Caucasian woman with ovarian carcinoma

    Bergmann, Troels K; Filppula, Anne M; Launiainen, Terhi

    2015-01-01

    % of the cohort geometric mean (385 L/h; range 176-726). She was hospitalised thrice, developed severe neuropathy and paclitaxel treatment was subsequently discontinued. In vitro, 30 min preincubation with 100 μM clopidogrel acyl-β-D-glucuronide inhibited the depletion rate of 0.5 μM paclitaxel by 51......AIM: The aim of this case report is to describe a novel pharmacokinetic drug-drug interaction between the antiplatelet agent clopidogrel and the antineoplastic agent paclitaxel. METHODS: The patient was identified in a previously described cohort of 93 patients with ovarian carcinoma treated...... with paclitaxel. The effect of clopidogrel acyl-β-D-glucuronide on the metabolism of paclitaxel was assessed in human liver microsomes. The analysis of clopidogrel in plasma and the quantification of paclitaxel and 6α-hydroxypaclitaxel in in vitro samples were performed by liquid chromatography tandem mass...

  5. Functional characterization of two microsomal fatty acid desaturases from Jatropha curcas L.

    Wu, Pingzhi; Zhang, Sheng; Zhang, Lin; Chen, Yaping; Li, Meiru; Jiang, Huawu; Wu, Guojiang

    2013-10-15

    Linoleic acid (LA, C18:2) and α-linolenic acid (ALA, C18:3) are polyunsaturated fatty acids (PUFAs) and major storage compounds in plant seed oils. Microsomal ω-6 and ω-3 fatty acid (FA) desaturases catalyze the synthesis of seed oil LA and ALA, respectively. Jatropha curcas L. seed oils contain large proportions of LA, but very little ALA. In this study, two microsomal desaturase genes, named JcFAD2 and JcFAD3, were isolated from J. curcas. Both deduced amino acid sequences possessed eight histidines shown to be essential for desaturases activity, and contained motif in the C-terminal for endoplasmic reticulum localization. Heterologous expression in Saccharomyces cerevisiae and Arabidopsis thaliana confirmed that the isolated JcFAD2 and JcFAD3 proteins could catalyze LA and ALA synthesis, respectively. The results indicate that JcFAD2 and JcFAD3 are functional in controlling PUFA contents of seed oils and could be exploited in the genetic engineering of J. curcas, and potentially other plants. Copyright © 2013 Elsevier GmbH. All rights reserved.

  6. Glucuronidation of trans-resveratrol by human liver and intestinal microsomes and UGT isoforms.

    Brill, Shirley S; Furimsky, Anna M; Ho, Mark N; Furniss, Michael J; Li, Yi; Green, Adam G; Bradford, Wallace W; Green, Carol E; Kapetanovic, Izet M; Iyer, Lalitha V

    2006-04-01

    Resveratrol (trans-resveratrol, trans-3,5,4'-trihydroxystilbene) is a naturally occurring stilbene analogue found in high concentrations in red wine. There is considerable research interest to determine the therapeutic potential of resveratrol, as it has been shown to have tumour inhibitory and antioxidant properties. This study was performed to investigate the glucuronidation of resveratrol and possible drug interactions via glucuronidation. Two glucuronide conjugates, resveratrol 3-O-glucuronide and resveratrol 4'-O-glucuronide, were formed by human liver and intestinal microsomes. UGT1A1 and UGT1A9 were predominantly responsible for the formation of the 3-O-glucuronide (Km = 149 microM) and 4'-O-glucuronide (Km = 365 microM), respectively. The glucuronide conjugates were formed at higher levels (up to 10-fold) by intestinal rather than liver microsomes. Resveratrol was co-incubated with substrates of UGT1A1 (bilirubin and 7-ethyl-10-hydroxycamptothecin (SN-38)) and UGT1A9 (7-hydroxytrifluoromethyl coumarin (7-HFC)). No major changes were noted in bilirubin glucuronidation in the presence of resveratrol. Resveratrol significantly inhibited the glucuronidation of SN-38 (Ki = 6.2 +/- 2.1 microM) and 7-HFC (Ki = 0.6 +/- 0.2 microM). Hence, resveratrol has the potential to inhibit the glucuronidation of concomitantly administered therapeutic drugs or dietary components that are substrates of UGT1A1 and UGT1A9.

  7. A Microsomal Proteomics View of H2O2- and ABA-Dependent Responses

    Alquraishi, May Majed; Thomas, Ludivine; Gehring, Chris; Marondedze, Claudius

    2017-01-01

    The plant hormone abscisic acid (ABA) modulates a number of plant developmental processes and responses to stress. In planta, ABA has been shown to induce reactive oxygen species (ROS) production through the action of plasma membrane-associated nicotinamide adenine dinucleotide phosphate (NADPH)-oxidases. Although quantitative proteomics studies have been performed to identify ABA- or hydrogen peroxide (H₂O₂)-dependent proteins, little is known about the ABA- and H₂O₂-dependent microsomal proteome changes. Here, we examined the effect of 50 µM of either H₂O₂ or ABA on the Arabidopsis microsomal proteome using tandem mass spectrometry and identified 86 specifically H₂O₂-dependent, and 52 specifically ABA-dependent proteins that are differentially expressed. We observed differential accumulation of proteins involved in the tricarboxylic acid (TCA) cycle notably in response to H₂O₂. Of these, aconitase 3 responded to both H₂O₂ and ABA. Additionally, over 30 proteins linked to RNA biology responded significantly to both treatments. Gene ontology categories such as 'response to stress' and 'transport' were enriched, suggesting that H₂O₂ or ABA directly and/or indirectly cause complex and partly overlapping cellular responses. Data are available via ProteomeXchange with identifier PXD006513.

  8. Stereoselective formation of a cholesterol ester conjugate from fenvalerate by mouse microsomal carboxyesterase(s).

    Miyamoto, J; Kaneko, H; Takamatsu, Y

    1986-06-01

    In accordance with in vivo findings, of the four chiral isomers of fenvalerate (S-5602 Sumicidin, Pydrin, [RS]-alpha-cyano-3-phenoxybenzyl [RS]-2-(4-chlorophenyl)isovalerate), only the [2R, alpha S]-isomer (B-isomer) yielded cholesteryl [2R]-2-(4-chlorophenyl)isovalerate (CPIA-cholesterol ester) in the in vitro study using several tissue homogenates of mice, rats, dogs, and monkeys. There were species differences in the extent of CPIA-cholesterol-ester formation, with mouse tissues showing relatively higher activity than those of other animals. The kidney, brain, and spleen of mice showed relatively higher capacities to form this ester compared to other tissues, and the enzyme activity was mainly localized in microsomal fractions. The CPIA-cholesterol ester did not seem to be produced by three known biosynthetic pathways of endogenous cholesterol esters--acyl-CoA:cholesterol O-acyltransferase (ACAT), lecithin:cholesterol O-acyltransferase (LCAT), and cholesterol esterase. Carboxyesterase(s) of mouse kidney microsomes solubilized by digitonin hydrolyzed only the B alpha-isomer of fenvalerate, yielding CPIA, whereas they yielded the corresponding cholesterol ester in the presence of artificial liposomes containing cholesterol. Thus, it appears that the stereoselective formation of the CPIA-cholesterol ester results from the stereoselective formation of the CPIA-carboxyesterase complex only from the B alpha-isomer, which subsequently undergoes cleavage by cholesterol to yield the CPIA-cholesterol ester.

  9. [Seric 21-hydroxilase antibodies in patients with anti-microsomal fraction antibodies. Autoimmune polyendocrine syndrome].

    Botta, Silvia; Roveto, Silvana; Rimoldi, Daniel

    2007-01-01

    Autoimmune polyendocrine syndrome (APS) is the association of autoimmune endocrine diseases, with other autoimmune nonendocrine disorders. APS types 1, 2 and 4 include autoimmune adrenalitis; this suggests the presence of autoantibodies. A specific serological marker for these is the anti 21- hydroxilase autoantibody (a21-OH). APS type 2 is the association of autoimmune adrenalitis, to autoimmune thyroid disease and/or diabetes mellitus, all these are induced by autoantibodies. Alopecia, vitiligo, myasthenia and other manifestations can be minor components. We sought to establish the prevalence of seric a21-OH in patients with positive anti-microsomal fraction autoantibodies, autoimmune thyroid disease and/or non-endocrine autoimmune diseases. We also aimed to diagnose incomplete forms of APS and to follow up patients at risk of progression to complete forms of APS. A population of 72 patients and another of 60 controls with negative anti-microsomal fraction autoantibodies were studied. Elevated seric a21-OH were found in two patients. Patient A with 47 U/ml had autoimmune hypothyroidism and myasthenia; and patient B with 8.75 U/ml had autoimmune hypothyrodism and vitiligo; they both lacked adrenal insufficiency. Seric a21-OH had a prevalence of 2.8%. Regarding the adrenal component, patients A and B had an incomplete and latent APS type 2. Considering a21-OH as markers of latent endocrine autoimmune diseases and taking into account the eventual risk of developing clinical manifestations, periodic biochemical and clinical follow-ups are recommended.

  10. A Microsomal Proteomics View of H2O2- and ABA-Dependent Responses

    Alquraishi, May Majed

    2017-08-21

    The plant hormone abscisic acid (ABA) modulates a number of plant developmental processes and responses to stress. In planta, ABA has been shown to induce reactive oxygen species (ROS) production through the action of plasma membrane-associated nicotinamide adenine dinucleotide phosphate (NADPH)-oxidases. Although quantitative proteomics studies have been performed to identify ABA- or hydrogen peroxide (H₂O₂)-dependent proteins, little is known about the ABA- and H₂O₂-dependent microsomal proteome changes. Here, we examined the effect of 50 µM of either H₂O₂ or ABA on the Arabidopsis microsomal proteome using tandem mass spectrometry and identified 86 specifically H₂O₂-dependent, and 52 specifically ABA-dependent proteins that are differentially expressed. We observed differential accumulation of proteins involved in the tricarboxylic acid (TCA) cycle notably in response to H₂O₂. Of these, aconitase 3 responded to both H₂O₂ and ABA. Additionally, over 30 proteins linked to RNA biology responded significantly to both treatments. Gene ontology categories such as \\'response to stress\\' and \\'transport\\' were enriched, suggesting that H₂O₂ or ABA directly and/or indirectly cause complex and partly overlapping cellular responses. Data are available via ProteomeXchange with identifier PXD006513.

  11. Risk of borderline ovarian tumors among women with benign ovarian tumors

    Guleria, Sonia; Jensen, Allan; Kjær, Susanne K

    2018-01-01

    tumors among women with a benign ovarian tumor. METHODS: This nationwide cohort study included all Danish women diagnosed with a benign ovarian tumor (n=139,466) during 1978-2012. The cohort was linked to the Danish Pathology Data Bank and standardized incidence ratios (SIR) with 95% confidence intervals...... (CI) were calculated. RESULTS: Women with benign ovarian tumors had increased risks for subsequent borderline ovarian tumors (SIR 1.62, 95% CI 1.43-1.82), and this applied to both serous (SIR 1.69, 95% CI 1.39-2.03) and mucinous (SIR 1.75, 95% CI 1.45-2.10) histotypes of borderline ovarian tumors....... The risk for borderline ovarian tumors was primarily increased for women diagnosed with a benign ovarian tumor before 40years of age. The risk remained increased up to 9years after a benign ovarian tumor diagnosis. Finally, the associations did not change markedly when analyzed for the different histotypes...

  12. Ovarian Cysts and Fertility: Is There a Connection?

    ... Is there a link between ovarian cysts and fertility? Answers from Charles Coddington, M.D. Some ovarian cysts can be associated with decreased fertility. However, it depends on the type of ovarian ...

  13. Bilateral synchronous benign ovarian neoplasm: A rare occurrence

    right ovarian mass, which revealed a left ovarian benign cystic teratoma and a right ovarian ... Women's reproductive health rights need to be encouraged and possibly legislated in our setting. ..... Med J Armed Forces India 2011;67(3):272-.

  14. Risks of Ovarian, Fallopian Tube, and Primary Peritoneal Cancer Screening

    ... black women. Different factors increase or decrease the risk of getting ovarian, fallopian tube, and primary peritoneal ... decrease the number of deaths from ovarian cancer. Risks of Ovarian, Fallopian Tube, and Primary Peritoneal Cancer ...

  15. Efficient Cycloaddition Reaction of Carbon Dioxide with Epoxide by Rhodamine Based Catalyst Under 1 atm Pressure

    Gong, Qing; Luo, Huadong; Cao, Di; Zhang, Haibo; Wang, Wenjing; Zhou, Xiaohai [Wuhan University, Wuhan (China)

    2012-06-15

    Rhodamine B (RhB) and rhodamine 6G (Rh6G) were employed as catalysts for the synthesis of cyclic carbonate from carbon dioxide and epoxide. It turned out that the catalytic activity of Rh6G was nearly 29 times higher than that of RhB at 1 atm pressure, 90 .deg. C. Furthermore, the catalytic efficiency of RhB and Rh6G was greatly enhanced with triethylamine as co-catalyst. Under the optimized conditions, the best isolated yield (93%) of cyclic carbonate was achieved without organic solvent and metal component

  16. Studies on whole cell fluorescence-based screening for epoxide hydrolases and Baeyer-Villiger monooxygenases

    Bicalho, Beatriz; Chen, Lu S.; Marsaioli, Anita J.; Grognux, Johann; Reymond, Jean-Louis

    2004-01-01

    Biocatalysis reactions were performed on microtiter plates (200 μL) aiming at the utilization of fluorogenic substrates (100 μmol L -1 ) for rapid whole cell screening for epoxide hydrolases (EHs) and Baeyer-Villiger monooxygenases (BVMOs). A final protocol was achieved for EHs, with 3 new enzymatic sources being detected (Agrobacterium tumefaciens, Pichia stipitis, Trichosporom cutaneum). The fluorogenic assay for BVMO did not work as expected. However, an approach to possible variables involved (aeration; pH) provided the first detection of a BVMO activity in T. cutaneum. (author)

  17. Direct gas-phase epoxidation of propylene to propylene oxide through radical reactions: A theoretical study

    Kizilkaya, Ali Can; Fellah, Mehmet Ferdi; Onal, Isik

    2010-03-01

    The gas-phase radical chain reactions which utilize O 2 as the oxidant to produce propylene oxide (PO) are investigated through theoretical calculations. The transition states and energy profiles were obtained for each path. The rate constants were also calculated. The energetics for the competing pathways indicate that PO can be formed selectively due to its relatively low activation barrier (9.3 kcal/mol) which is in a good agreement with the experimental value (11 kcal/mol) of gas-phase propylene epoxidation. The formation of the acrolein and combustion products have relatively high activation barriers and are not favored. These results also support the recent experimental findings.

  18. Catalytic applications of immobilized ionic liquids for synthesis of cyclic carbonates from carbon dioxide and epoxides

    Kim, Dong-Woo; Roshan, Roshith; Tharun, Jose; Cherian, Amal; Park, Dae-Won

    2013-01-01

    The catalytic applicability of ionic liquids immobilized on various support materials such as silica, polystyrene and biopolymers in the cycloaddition of carbon dioxide with epoxides is reviewed in this work. Comparisons of the catalytic efficiency of these various catalysts have been done from the aspect of turnover number and reusability. The studies revealed that ionic liquids or support materials possessing hydrogen bonding capable groups exhibited enhanced catalytic activity towards cyclic carbonate synthesis. Moreover, the increased quest towards environmentally benign materials has renewed the search for biocompatible materials as support for ionic liquids

  19. Synthesis of Carbasugars from Aldonolactones: Ritter-Type Epoxide Opening of Polyhydroxylated Aminocyclopentanes

    Lundt, Inge; Johansen, Steen Karsk; Kornø, Hanne Tøfting

    1999-01-01

    Using the cis-fused cyclopentane-1,4-lactone, 1(R),5(S)-7(R),8(R)-dihydroxy-2-oxabicyclo[3.3.0]oct-3-one (1), as starting material, 5-deoxycarba-*-L-xylo-hexofuranose (6) together with ?- (12) and ?-1-amino-1,5-dideoxycarba-L-xylo-hexofuranose (16) have been prepared using a number...... of stereoselective transformations. The key step was the regioselective opening of the epoxide 1(R),5(S)-7(R),8(R)-epoxy-2-oxabicyclo[3.3.0]oct-3-one (4) with different nucleophiles....

  20. Studying the iodine leaching from the compositions based on epoxide resin and lead iodide

    Kalinin, N.N.; Elizarova, A.N.

    1988-01-01

    When studying iodine leaching, the possibility to use solid compositions, produced by incorporation of dry powdered lead iodide and its aqueous suspension into epoxide resin for long-term immobilization of iodine-129 under conditions of monitored storage, is evaluated. Analysis of the results obtained has shown that leaching rate in the first 4 days has the maximum value and constitutes (4.2 - 2700.0) x 10 -6 cm/day. Then the process of leaching is determined by diffusion mechanism. For samples, prepared by wet lead iodide incorporation the rate of leaching is higher than that of the corresponding samples prepared by dry compound incorporation

  1. Quantum chemical study of the mechanism of action of vitamin K epoxide reductase (VKOR)

    Deerfield, David, II; Davis, Charles H.; Wymore, Troy; Stafford, Darrel W.; Pedersen, Lee G.

    Possible model, but simplistic, mechanisms for the action of vitamin K epoxide reductase (VKOR) are investigated with quantum mechanical methods (B3LYP/6-311G**). The geometries of proposed model intermediates in the mechanisms are energy optimized. Finally, the energetics of the proposed (pseudo-enzymatic) pathways are compared. We find that the several pathways are all energetically feasible. These results will be useful for designing quantum mechanical/molecular mechanical method (QM/MM) studies of the enzymatic pathway once three-dimensional structural data are determined and available for VKOR.

  2. Rapid epoxidation of palm acid oil with lipase action under microwave irradiation

    Saifuddin, N.; Wei Zhan Lee; Koh, X.N.; Ramesh, S.; Abdullah, S.F.

    2010-01-01

    In view of growing environmental concerns and tightened regulations over contaminants and pollution in the environment in recent years, calls for biodegradable and nontoxic vegetable oil-based lubricants are abound. They have very low volatility due to the higher molecular weight of the triacylglycerol molecule and a narrow range of viscosity changes with temperature. Polar ester groups in the molecule are able to adhere to metal surfaces, and therefore, possess good boundary lubrication properties. In addition, vegetable oils have high solubilising power for polar contaminants and additive molecules. However, vegetable oils show poor oxidative and thermal stability primarily due to the presence of unsaturation. The presence of ester functionality also renders these oils susceptible to hydrolytic breakdown. The proposed modification of the vegetable oils is an important manner to obtain potentially useful products using a renewable feedstock. In designing a green process to effectively carry out the epoxidation reaction, we report herein, an inexpensive, practical, safe and environmentally friendly method to epoxidize palm acid oil under extremely mild conditions. This work highlights the increased reaction rate of the epoxidation process when microwave irradiation is introduced. The starting material used is Palm Acid Oil, a by-product of the alkali refining process of palm oil. Acid oil can serve as an inexpensive raw materials and are very good substitute for neat vegetable oil such as palm oil for the production of bio lubricant. It is high in Free Fatty Acids (FFA) and is the ideal material for the epoxidation process due to the importance of FFAs in producing peroxy-acids as an oxygen carrier. The double bonds the triglycerides are reacted with a per acid, generated for safety reasons in situ using hydrogen peroxide. Novozym 435 acts as the catalyst in the process and with its good selectivity, the occurrence of by-products is controlled. The method and

  3. Epoxide resin coatings of cans - substance transfer to oil-containing foods possible

    German Federal Institute for Risk Assessment

    2016-01-01

    Oily foods in cans can contain levels of Cyclo-di-BADGE (CdB) that present a health risk for high consumers. This is the result of a health risk assessment of the Federal Institute for Risk Assessment (BfR) in which the institute analysed data on the CdB content of canned fish preserved in oil. CdB is a molecule consisting of Bisphenol A (BPA) and Bisphenol A diglycidyl ether (BADGE). It is formed as a by-product during the production of epoxide resins which are, for example, used for the int...

  4. Treatment Results of Ovarian Dysqerminoma

    Chung, Eun Ji; Suh, Chang Ok; Seong, Jin Sil; Keum, Ki Chang; Kim, Gwi Eon

    1996-01-01

    Purpose : We tried to evaluate the clinical characteristics, the treatment methods, the results of treatments, and the patterns of failure in ovarian dysgerminoma retrospectively. According to the results we would like to suggest the proper management guideline of stage la ovarian dysgerminoma patients who want to maintain fertility. Methods and Materials : Between 1975 and 1990, 34 patients with ovarian dysgerminoma were treated at the Yonsei University Hospital. The case records of these patients have been reviewed for presenting symptoms, treatment methods, local control, and survival following treatment. Excluded from analysis were five patients with mixed ovarian germ cell tumors and gonadoblastomas (46,XY). Treatment results of the twenty nine patients were analysed by each treatment modality. Twenty one patients were treated with surgery and postoperative adjuvant radiotherapy(group 1). The other eight patients were treated with operation alone (group 2). The median age of twenty-nine patients was 23 years with a range of 8 to 39 years. Presenting symptoms were abdominal mass(20), pelvic discomfort or pain(5) et al. Radiotherapy was performed by 10MV LINAC or Co-60 teletherapy unit. The total radiation dose of the whole abdomen was 20-25 Gy/3 weeks, 1-1.5 Gy/fraction with a boost to the whole pelvis 10-15 Gy / 1-2 weeks1.8-2.0 Gy/fraction. Advanced stage disease (stage II or stage III) patients received prophylactic mediastinal and supraclavicular irradiation to a dose of 16-26 Gy. Median duration of follow-up of living patients was 80 months (range : 13-201 months). Results : All of the twenty one patients of group 1 were alive without disease (100%). Among the eight patients who were not treated with radiotherapy (group 2), six patients developed local recurrence. Four patients referred with recurrent disease were treated with salvage radiotherapy. Three of four patients were salvaged and one patient who had recurrent intra-abdominal disease died of

  5. Exploration of Cocatalyst Effects on a Bimetallic Cobalt Catalyst System: Enhanced Activity and Enantioselectivity in Epoxide Polymerization

    Widger, Peter C. B.; Ahmed, Syud M.; Coates, Geoffrey W.

    2011-01-01

    Organic ionic compounds were synthesized and investigated as cocatalysts with a bimetallic cobalt complex for enantioselective epoxide polymerization. The identities of both the cation and the anion were systematically varied, and the subsequent reactivity was studied. The nature of the ionic cocatalyst dramatically impacted the rate and enantioselectivity of the catalyst system. The ionic cocatalyst [P(N=P(N(CH2)4)3) 4 +][tBuCO2 -] in combination with a bimetallic cobalt complex produced a catalyst system that exhibited the greatest activity and selectivity for a variety of monosubstituted epoxides. © 2011 American Chemical Society.

  6. Exploration of Cocatalyst Effects on a Bimetallic Cobalt Catalyst System: Enhanced Activity and Enantioselectivity in Epoxide Polymerization

    Widger, Peter C. B.

    2011-07-26

    Organic ionic compounds were synthesized and investigated as cocatalysts with a bimetallic cobalt complex for enantioselective epoxide polymerization. The identities of both the cation and the anion were systematically varied, and the subsequent reactivity was studied. The nature of the ionic cocatalyst dramatically impacted the rate and enantioselectivity of the catalyst system. The ionic cocatalyst [P(N=P(N(CH2)4)3) 4 +][tBuCO2 -] in combination with a bimetallic cobalt complex produced a catalyst system that exhibited the greatest activity and selectivity for a variety of monosubstituted epoxides. © 2011 American Chemical Society.

  7. Management of ovarian cysts in infants

    Yan Xue-qiang

    2015-01-01

    Full Text Available Background: To discuss the experience of diagnosis and treatment of ovarian cyst in infants. Materials and Methods: A retrospective review was conducted on 20 infants who suffered from ovarian cyst. Results: There were no dysplasia ovarian was found in children which were preoperatively diagnosed simplex cyst. Within thirteen children preoperatively detected mixed cystic-solid lesion, six cases ovarian cysts disappeared and two cases underwent poor blood supply in the following time. Conclusion: Adverse effects for ovarian cyst in infants can be prevented by agressive surgical intervention. Harmful effects of ovarian cyst can be prevented by positive surgical intervention despite the diagnostic difficulties in children with clinical symptoms of this condition.

  8. Ovarian cancer immunotherapy: opportunities, progresses and challenges

    Stevens Richard

    2010-02-01

    Full Text Available Abstract Due to the low survival rates from invasive ovarian cancer, new effective treatment modalities are urgently needed. Compelling evidence indicates that the immune response against ovarian cancer may play an important role in controlling this disease. We herein summarize multiple immune-based strategies that have been proposed and tested for potential therapeutic benefit against advanced stage ovarian cancer. We will examine the evidence for the premise that an effective therapeutic vaccine against ovarian cancer is useful not only for inducing remission of the disease but also for preventing disease relapse. We will also highlight the questions and challenges in the development of ovarian cancer vaccines, and critically discuss the limitations of some of the existing immunotherapeutic strategies. Finally, we will summarize our own experience on the use of patient-specific tumor-derived heat shock protein-peptide complex for the treatment of advanced ovarian cancer.

  9. Influence of ovarian manipulation on reproductive endocrinology in polycystic ovarian syndrome and regularly cycling women

    Hendriks, M.L.; König, T.E.; Soleman, R.S.; Korsen, T.; Schats, R.; Hompes, P.G.A.; Homburg, R.R.; Lambalk, C.B.

    2013-01-01

    Objective: Little is known about the function of the ovarian neuronal network in humans. In many species, copulation influences endocrinology through this network. As a first step, the possible influence of ovarian mechanical manipulation on pituitary and ovarian hormones was evaluated in polycystic

  10. Incipient ovarian failure and premature ovarian failure show the same immunological profile

    van Kasteren, YM; von Blomberg, M; Hoek, A; de Koning, C; Lambalk, N; van Montfrans, J; Kuik, J

    PROBLEM: Incipient ovarian failure (IOF) is characterized by regular menstrual cycles, infertility and a raised early-follicular FSH in women under 40. IOF might be a precursor or a mitigated form of premature ovarian failure (POF). Disturbances in the immune system may play a role in ovarian

  11. Screening of the residual normal ovarian tissue adjacent to orthotopic epithelial ovarian carcinomas in nude mice.

    Zhu, G H; Wang, S T; Yao, M Z; Cai, J H; Chen, C Y; Yang, Z X; Hong, L; Yang, S Y

    2014-04-16

    The objective of this study was to explore the feasibility and methods of screening the residual normal ovarian tissue adjacent to orthotopic ovarian carcinomas in nude mice. Human epithelial ovarian cancer cells (OVCAR3) were subcutaneously implanted for a tumor source and ovarian orthotopic transplantation. The cancer tissue, proximal paraneoplastic tissue, middle paraneoplastic tissue, remote paraneoplastic tissue, and normal ovarian tissue were removed. CK-7, CA125, p53, survivin, MMP-2, and TIMP-2 expression was detected by reverse transcription polymerase chain reaction. We obtained 35 paraneoplastic residual ovarian tissues with normal biopsies from 40 cases of an orthotopic epithelial ovarian carcinoma model (87.5%). CK-7, CA125, p53, survivin, MMP-2, and TIMP-2 expression was lower in proximal paraneoplastic tissue than in cancer tissue (P tissue (P tissue as well as among residual normal ovarian tissues with different severity (P > 0.05). In ovarian tissues of 20 normal nude mice, the expression of CK- 7, CA125, p53, survivin, MMP-2, and TIMP-2 was negative. Overall, the expression levels of CK-7, CA125, p53, survivin, MMP-2, TIMP-2, and other molecular markers showed a decreasing trend in the non-cancer tissue direction. The expression levels can be used as standards to screen residual normal ovarian tissue. We can obtain relatively safe normal ovarian tissues adjacent to epithelial ovarian cancer.

  12. Clinicoroentgenological diagnosis of chronic venous ovarian insufficiency

    Grakova, L.S.; Galkin, E.V.; Naumova, E.B.

    1989-01-01

    The paper is devoted to clinicoroentgenological correlations of venous renogonadal hemodynamics in 168 women of reproductive age (151 women with infertility, habitual abortion, disordered menstrual function and 17 patients without disorders of the reproductive tract). Clinicolaboratory investigation was followed by visceral and parietal flebography for the detection of a pathological venous reflux into the ovarian pampiniform plexus. Clinicoroentgenological semiotics of chronic venous ovarian insufficiency was analyzed. Infertility was shown to be the main clinical manifestation of ovarian varicocele

  13. Mechanisms and Chemoprevention of Ovarian Carcinogenesis

    Cvetkovic, Dusica

    2008-01-01

    .... We have demonstrated that DMBAinduced mutagenesis in the rat ovary, combined with gonadotropin hormone-mediated enhanced mitogenesis of the ovarian surface epithelium, produces lesions ranging...

  14. Vanishing large ovarian cyst with thyroxine therapy.

    Dharmshaktu, Pramila; Kutiyal, Aditya; Dhanwal, Dinesh

    2013-01-01

    A 21-year-old female patient recently diagnosed with severe hypothyroidism was found to have a large ovarian cyst. In view of the large ovarian cyst, she was advised to undergo elective laparotomy in the gynaecology department. She was further evaluated in our medical out-patient department (OPD), and elective surgery was withheld. She was started on thyroxine replacement therapy, and within a period of 4 months, the size of the cyst regressed significantly, thereby improving the condition of the patient significantly. This case report highlights the rare and often missed association between hypothyroidism and ovarian cysts. Although very rare, profound hypothyroidism that can cause ovarian cysts in an adult should always be kept in the differential diagnosis to avoid unnecessary ovarian surgery. Hypothyroidism should be considered in the differential diagnosis of adult females presenting with multicystic ovarian tumours.Adequate thyroid hormone replacement therapy can prevent these patients from undergoing unnecessary and catastrophic ovarian resection.Surgical excision should be considered only when adequate thyroid replacement therapy fails to resolve ovarian enlargement.In younger women with ovarian cysts, it is also desirable to avoid unnecessary surgery so as to not compromise fertility in the future.

  15. PARP Inhibitors in Ovarian Cancer.

    Mittica, Gloria; Ghisoni, Eleonora; Giannone, Gaia; Genta, Sofia; Aglietta, Massimo; Sapino, Anna; Valabrega, Giorgio

    2018-03-05

    Treatment of Epithelial Ovarian Cancer (EOC), historically based on surgery and platinum doublet chemotherapy, is associated with high risk of relapse and poor prognosis for recurrent disease. In this landscape, the innovative treatment with PARP inhibitors (PARPis) demonstrated an outstanding activity in EOC, and is currently changing clinical practice in BRCA mutant patients. To highlight the mechanism of action, pharmacokinetics, clinical activity, indications and current strategies of development of Olaparib, Niraparib, Rucaparib, Talazoparib and Veliparib, the 5 most relevant PARPis. We performed a review on Pubmed using 'ovarian cancer' and the name of each PARPi (PARP inhibitor) discussed in the review as Medical Subject Headings (MeSH) keywords. The same search was performed on "clinicaltrial.gov" to identify ongoing clinical trials and on "google.com/patents" and "uspto.gov" for recent patents exploring PARPIs in ovarian cancer. Olaparib, Niraparib and Rucaparib are already approved for treatment of recurrent EOC and their indications are partially overlapping. Talazoparib and Veliparib are promising PARPis, but currently under investigation in early phase trials. Several studies are evaluating PARPis in monotherapy or in associations, in a wide range of settings (i.e. first line, neoadjuvant, platinum-sensitive and resistant disease). PARPis are valuable options in patients with recurrent ovarian cancer with promising activity in different stages of this disease. Further studies are required to better define optimal clinical settings, predictors of response beyond BRCA mutations and strategies to overcome secondary resistance of PARPis therapy in EOC. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  16. Hereditary breast and ovarian cancer

    Nielsen, Finn Cilius; Hansen, Thomas van Overeem; Sørensen, Claus Storgaard

    2016-01-01

    Genetic abnormalities in the DNA repair genes BRCA1 and BRCA2 predispose to hereditary breast and ovarian cancer (HBOC). However, only approximately 25% of cases of HBOC can be ascribed to BRCA1 and BRCA2 mutations. Recently, exome sequencing has uncovered substantial locus heterogeneity among...... of putative causal variants and the clinical application of new HBOC genes in cancer risk management and treatment decision-making....

  17. Direct characterization of cotton fabrics treated with di-epoxide by nuclear magnetic resonance.

    Xiao, Min; Chéry, Joronia; Keresztes, Ivan; Zax, David B; Frey, Margaret W

    2017-10-15

    A non-acid-based, di-functional epoxide, neopentyl glycol diglycidyl ether (NPGDGE), was used to modify cotton fabrics. Direct characterization of the modified cotton was conducted by Nuclear Magnetic Resonance (NMR) without grinding the fabric into a fine powder. NaOH and MgBr 2 were compared in catalyzing the reaction between the epoxide groups of NPGDGE and the hydroxyl groups of cellulose. Possible reaction routes were discussed. Scanning electron microscopy (SEM) images showed that while the MgBr 2 -catalyzed reaction resulted in self-polymerization of NPGDGE, the NaOH-catalyzed reaction did not. Fourier transform infrared spectroscopy (FTIR) showed that at high NaOH concentration cellulose restructures from allomorph I to II. NMR studies verified the incorporation of NPGDGE into cotton fabrics with a clear NMR signal, and confirmed that at higher NaOH concentration the efficiency of grafting of NPGDGE was increased. This demonstrates that use of solid state NMR directly on woven fabric samples can simultaneously characterize chemical modification and crystalline polymorph of cotton. No loss of tensile strength was observed for cotton fabrics modified with NPGDGE. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. STUDY OF EPOXIDE DECYCLISATION OF CARYOPHYLENE OXIDE WITH SYNTHETIC ZEOLITE AS CATALYSTS

    Winarto Haryadi

    2010-06-01

    Full Text Available The reaction of epoxide ring opening of caryophillene oxide has been done using zeolite H-Y, H-sodalit, and H-ZSM-5 as catalysts. The reactions were done in two types, there were in dioxane solvent at temperature of 110 oC and without solvent at temperature of 175 oC. The catalyst weight was 10 % from caryophillene oxide weight, and the time of reaction was four hours. The product of reaction was analyzed using GC, FTIR, and GC-MS. The reactions of caryophillene oxide in dioxane solvent with the three kinds of zeolites did not give any targeted product. Whereas, the reactions without solvent gave three main products, there was one compound with one group of secondary hidroxyl (secondary alcohol, and two compounds of ketone from caryophillene. The reaction product of caryophillene oxide obtained without using solvent with the three type of catalysts were then compared. Conversion of three main products produced by H-ZSM-5 catalyst, H-sodalit catalyst and H-Y catalyst were 82.11 %, 54.92 % and 38.53 % respectively. For that reason, the transformation of caryophillene oxide using H-ZSM-5 catalyst was considered to be the best selective product. The alcohol product was resulted from reaction between caryophillene oxide and Bronsted acid, and  the ketone products was resulted from the reaction with Lewis acid in zeolite.   Keywords: Epoxide ring opening, HY, H-sodalit and HZSM-5

  19. Polymerization of Oriental Lacquer (Urushi with Epoxidized Linseed Oil as a New Reactive Diluent

    Takahisa Ishimura

    2015-01-01

    Full Text Available A hybrid lacquer (HBL paint prepared by combining a natural kurome lacquer (KL paint and an amino silane reagent, for example, N-(2-aminoethyl-3-aminopropyl triethoxysilane (AATES, produced a polymerized film faster than the KL paint alone. However, the viscosity of the HBL paint was too viscous for easy handling. Addition of 10 wt% of an epoxidized linseed oil, ELO-6, with 6.4 mol% epoxidation as a reactive diluent to the HBL paint decreased the viscosity by 1/2 from 25476 mPa·s to 12841 mPa·s and improved the ease of coatability. The polymerization mechanism was elucidated by NMR measurements of extracts from the resulting polymerization films, suggesting that amino groups in the HBL paint reacted with epoxy groups of ELO-6 in the lacquer matrix, and then the complex reacted with double bonds of the urushiol side-chain by autooxidation and cross-linking reactions to give a hard polymerized film with a high quality of color and gloss. These results indicate that the addition of ELO-6 improved the polymerizability of both KL and HBL paints without decreasing the quality of the resulting films.

  20. Development of SBR-Nano clay Composites with Epoxidized Natural Rubber as Compatibilizer

    Rajasekar, R.; Das, Ch.K.; Gert Heinrich, G.; Das, A.

    2009-01-01

    The significant factor that determines the improvement of properties in rubber by the incorporation of nano clay is its distribution in the rubber matrix. The simple mixing of nonpolar rubber and organically modified nano clay will not contribute for the good dispersion of nano filler in the rubbery matrix. Hence a polar rubber like epoxidized natural rubber (ENR) can be used as a compatibilizer in order to obtain a better dispersion of the nano clay in the matrix polymer. Epoxidized natural rubber and organically modified nano clay composites (EC) were prepared by solution mixing. The nano clay employed in this study is Cloisite 20A. The obtained nano composites were incorporated in styrene butadiene-rubber (SBR) compounds with sulphur as a curing agent. The morphology observed through X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HR-TEM) shows that the nano clay is highly intercalated in ENR, and further incorporation of EC in SBR matrix leads to partial exfoliation of the nano clay. Dynamic mechanical thermal analysis showed an increase in storage modulus and lesser damping characteristics for the compounds containing EC loading in SBR matrix. In addition, these compounds showed improvement in the mechanical properties.

  1. Aerobic methylcyclohexane-promoted epoxidation of stilbene over gold nanoparticles supported on Gd-doped titania

    Mendez, Violaine; Guillois, Kevin; Daniè le, Sté phane; Tuel, Alain; Caps, Valerie

    2010-01-01

    Aerobic partial oxidations of alkanes and alkenes are important processes of the petrochemical industry. The radical mechanisms involved can be catalyzed by soluble salts of transition metals (Co, Cu, Mn...). We show here that the model methylcyclohexane/stilbene co-oxidation reaction can be efficiently catalyzed at lower temperature by supported gold nanoparticles. The support has little influence on gold intrinsic activity but more on the apparent reaction rates which are a combination of catalytic activity and diffusion limitations. These are here minimized by using gadolinium-doped titania nanocrystallites as support for gold nanoparticles. This material is obtained by mild hydrolysis of a new Gd4TiO(OiPr)14 bimetallic oxoalkoxide. It leads to enhanced wettability of the < 3 nm gold particles in the tert-butyl hydroperoxide (TBHP)-initiated epoxidation of stilbene in methylcyclohexane; Au/TiO2:Gd3+ is in turn as active as the state-of-the-art hydrophobic Au/SiO2 catalyst. The rate-determining step of this reaction is identified as the gold-catalyzed homolytic decomposition of TBHP generating radicals and initiating the methylcyclohexane-mediated epoxidation of stilbene, yielding a methylcyclohexan-1-ol/trans-stilbene oxide mixture. Methylcyclohexan-1-ol can also be obtained in the absence of the alkene in the gold-catalyzed solvent-free autoxidation of methylcyclohexane, evidencing the catalytic potential of gold nanoparticles for low temperature C-H activation. © 2010 The Royal Society of Chemistry.

  2. Mechanistic aspects of the metal catalyzed alternating copolymerization of epoxides and carbon monoxide.

    Allmendinger, Markus; Molnar, Ferenc; Zintl, Manuela; Luinstra, Gerrit A; Preishuber-Pflügl, Peter; Rieger, Bernhard

    2005-09-05

    The cobalt-catalyzed alternating copolymerization of epoxides and CO is a novel, direct approach to aliphatic polyesters, such as poly(hydroxybutyrate) (PHB). This reaction was found to be catalyzed by Ph3Si[Co(CO)4] (4) and pyridine affording in a first step the stable mono-insertion product Ph3Si-O-CH(CH3)-CH2-CO-Co(CO)4 (5). However, a profound mechanistic understanding, especially of the role of pyridine as the key component for the polymerization reaction was missing. ATR-IR online monitoring under catalytic conditions and DFT calculations were used to show that an acylpyridinium cation is formed by cleavage of the cobalt-acyl bond of 5 in the presence of pyridine. The Lewis acid thus generated activates the next incoming epoxide monomer for ring opening through [Co(CO)4]-. The catalytic cycle is completed by a subsequent CO insertion in the new cobalt-alkyl bond. The calculations are used to explore the energetic hypersurface of the polymerization reaction and are complemented by extended experimental investigations that also support the mechanistic hypotheses.

  3. MWCNTs-reinforced epoxidized linseed oil plasticized polylactic acid nanocomposite and its electroactive shape memory behaviour.

    Alam, Javed; Alam, Manawwer; Raja, Mohan; Abduljaleel, Zainularifeen; Dass, Lawrence Arockiasamy

    2014-10-31

    A novel electroactive shape memory polymer nanocomposite of epoxidized linseed oil plasticized polylactic acid and multi-walled carbon nanotubes (MWCNTs) was prepared by a combination of solution blending, solvent cast technique, and hydraulic hot press moulding. In this study, polylactic acid (PLA) was first plasticized by epoxidized linseed oil (ELO) in order to overcome the major limitations of PLA, such as high brittleness, low toughness, and low tensile elongation. Then, MWCNTs were incorporated into the ELO plasticized PLA matrix at three different loadings (2, 3 and 5 wt. %), with the aim of making the resulting nanocomposites electrically conductive. The addition of ELO decreased glass transition temperature, and increased the elongation and thermal degradability of PLA, as shown in the results of differential scanning calorimetry (DSC), tensile test, and thermo gravimetric analysis (TGA). Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to observe surface morphology, topography, and the dispersion of MWCNTs in the nanocomposite. Finally, the electroactive-shape memory effect (electroactive-SME) in the resulting nanocomposite was investigated by a fold-deploy "U"-shape bending test. As per the results, the addition of both ELO and MWCNTs to PLA matrix seemed to enhance its overall properties with a great deal of potential in improved shape memory. The 3 wt. % MWCNTs-reinforced nanocomposite system, which showed 95% shape recovery within 45 s at 40 DC voltage, is expected to be used as a preferential polymeric nanocomposite material in various actuators, sensors and deployable devices.

  4. MWCNTs-Reinforced Epoxidized Linseed Oil Plasticized Polylactic Acid Nanocomposite and Its Electroactive Shape Memory Behaviour

    Javed Alam

    2014-10-01

    Full Text Available A novel electroactive shape memory polymer nanocomposite of epoxidized linseed oil plasticized polylactic acid and multi-walled carbon nanotubes (MWCNTs was prepared by a combination of solution blending, solvent cast technique, and hydraulic hot press moulding. In this study, polylactic acid (PLA was first plasticized by epoxidized linseed oil (ELO in order to overcome the major limitations of PLA, such as high brittleness, low toughness, and low tensile elongation. Then, MWCNTs were incorporated into the ELO plasticized PLA matrix at three different loadings (2, 3 and 5 wt. %, with the aim of making the resulting nanocomposites electrically conductive. The addition of ELO decreased glass transition temperature, and increased the elongation and thermal degradability of PLA, as shown in the results of differential scanning calorimetry (DSC, tensile test, and thermo gravimetric analysis (TGA. Scanning electron microscopy (SEM and atomic force microscopy (AFM were used to observe surface morphology, topography, and the dispersion of MWCNTs in the nanocomposite. Finally, the electroactive-shape memory effect (electroactive-SME in the resulting nanocomposite was investigated by a fold-deploy “U”-shape bending test. As per the results, the addition of both ELO and MWCNTs to PLA matrix seemed to enhance its overall properties with a great deal of potential in improved shape memory. The 3 wt. % MWCNTs-reinforced nanocomposite system, which showed 95% shape recovery within 45 s at 40 DC voltage, is expected to be used as a preferential polymeric nanocomposite material in various actuators, sensors and deployable devices.

  5. Precursor effect on the property and catalytic behavior of Fe-TS-1 in butadiene epoxidation

    Wu, Mei; Zhao, Huahua; Yang, Jian; Zhao, Jun; Song, Huanling; Chou, Lingjun

    2017-11-01

    The effect of iron precursor on the property and catalytic behavior of iron modified titanium silicalite molecular sieve (Fe-TS-1) catalysts in butadiene selective epoxidation has been studied. Three Fe-TS-1 catalysts were prepared, using iron nitrate, iron chloride and iron sulfate as precursors, which played an important role in adjusting the textural properties and chemical states of TS-1. Of the prepared Fe-TS-1 catalysts, those modified by iron nitrate (FN-TS-1) exhibited a significant enhanced performance in butadiene selective epoxidation compared to those derived from iron sulfate (FS-TS-1) or iron chloride (FC-TS-1) precursors. To obtain a deep understanding of their structure-performance relationship, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Temperature programmed desorption of NH3 (NH3-TPD), Diffuse reflectance UV-Vis spectra (DR UV-Vis), Fourier transformed infrared spectra (FT-IR) and thermal gravimetric analysis (TGA) were conducted to characterize Fe-TS-1 catalysts. Experimental results indicated that textural structures and acid sites of modified catalysts as well as the type of Fe species influenced by the precursors were all responsible for the activity and product distribution.

  6. Surface science study of selective ethylene epoxidation catalyzed by the Ag(110) surface: Structural sensitivity

    Campbell, C.T.

    1984-01-01

    The selective oxidation of ethylene to ethylene epoxide (C 2 H 4 +1/2O 2 →C 2 H 4 O) over Ag is the simplest example of kinetically controlled, selective heterogeneous catalysis. We have studied the steady-state kinetics and selectivity of this reaction for the first time on a clean, well-characterized Ag(110) surface by using a special apparatus which allows rapid (approx.20 s) transfer between a high-pressure catalytic microreactor and an ultrahigh vacuum surface analysis (AES, XPS, LEED, TDS) chamber. The effects of temperature and reactant pressures upon the rate and selectivity are virtually identical on Ag(110) and supported, high surface area Ag catalysts. The absolute specific rate (per Ag surface atom) is, however, some 100-fold higher for Ag(110) than for high surface area catalysts. This is related to the well-known structural sensitivity of this reaction. It is postulated that a small percentage of (110) planes (or [110]-like sites) are responsible for most of the catalytic activity of high surface area catalysts. The high activity of the (110) plane is attributed to its high sticking probability for dissociative oxygen adsorption, since the rate of ethylene epoxidation is shown in a related work [Ref. 1: C. T. Campbell and M. T. Paffett, Surf. Sci. (in press)] to be proportional to the coverage of atomically adsorbed oxygen at constant temperature and ethylene pressure

  7. Epoxides cross-linked hexafluoropropylidene polybenzimidazole membranes for application as high temperature proton exchange membranes

    Yang, Jingshuai; Xu, Yixin; Liu, Peipei; Gao, Liping; Che, Quantong; He, Ronghuan

    2015-01-01

    Covalently cross-linked hexafluoropropylidene polybenzimidazole (F 6 PBI) was prepared and used to fabricate high temperature proton exchange membranes with enhanced mechanical strength against thermoplastic distortion. Three different epoxides, i.e. bisphenol A diglycidyl ether (R 1 ), bisphenol A propoxylate diglycidyl ether (R 2 ) and poly(ethylene glycol) diglycidyl ether (R 3 ), were chosen as the cross-linkers to investigate the influence of their structures on the properties of the cross-linked F 6 PBI membranes. All the cross-linked F 6 PBI membranes displayed excellent stability towards the radical oxidation. Comparing with the pure F 6 PBI membrane, the cross-linked F 6 PBI membranes showed high acid doping level but less swelling after doping phosphoric acid at elevated temperatures. The mechanical strength at 130 °C was improved from 0.4 MPa for F 6 PBI membrane to a range of 0.8–2.0 MPa for the cross-linked F 6 PBI membranes with an acid doping level as high as around 14, especially for that crosslinking with the epoxide (R 3 ), which has a long linear structure of alkyl ether. The proton conductivity of the cross-linked membranes was increased accordingly due to the high acid doping levels. Fuel cell tests demonstrated the technical feasibility of the acid doped cross-linked F 6 PBI membranes for high temperature proton exchange membrane fuel cells

  8. Acetyl-L-Carnitine Hydrochloride in Preventing Peripheral Neuropathy in Patients With Recurrent Ovarian Epithelial Cancer, Primary Peritoneal Cavity Cancer, or Fallopian Tube Cancer Undergoing Chemotherapy

    2014-12-29

    Fatigue; Malignant Ovarian Mixed Epithelial Tumor; Neuropathy; Neurotoxicity Syndrome; Ovarian Brenner Tumor; Ovarian Clear Cell Cystadenocarcinoma; Ovarian Endometrioid Adenocarcinoma; Ovarian Mucinous Cystadenocarcinoma; Ovarian Serous Cystadenocarcinoma; Pain; Recurrent Fallopian Tube Carcinoma; Recurrent Ovarian Carcinoma; Recurrent Primary Peritoneal Carcinoma

  9. Effect of cholesterol feeding on tissue lipid perioxidation, glutathione peroxidase activity and liver microsomal functions in rats and guinea pigs

    TSAI, A. C.; THIE, G. M.; Lin, C. R.

    1977-01-01

    The effect of cholesterol feeding on liver and aortic nonenzymatic lipid peroxidation and glutathione peroxidase activities, and on liver microsomal NADPH-dependent lipid peroxidation, codeine hydroxylation and cytochrome P-450 levels was examined in rats and guinea pigs. One percent cholesterol was

  10. Activation of the microsomal glutathione-S-transferase and reduction of the glutathione dependent protection against lipid peroxidation by acrolein

    Haenen, G R; Vermeulen, N P; Tai Tin Tsoi, J N; Ragetli, H M; Timmerman, H; Blast, A

    1988-01-01

    Allyl alcohol is hepatotoxic. It is generally believed that acrolein, generated out of allyl alcohol by cytosolic alcohol dehydrogenase, is responsible for this toxicity. The effect of acrolein in vitro and in vivo on the glutathione (GSH) dependent protection of liver microsomes against lipid

  11. Cytotoxicity of MEIC chemicals Nos. 11-30 in 3T3 mouse fibroblasts with and without microsomal activation

    Rasmussen, Eva

    1999-01-01

    acid, propranolol, thioridazine, lithium sulfate, copper sulfate and thallium sulfate, whereas the cytotoxicity of 1,1,1-trichloroethylene, phenol, nicotine, and paraquat was significantly increased by use of the microsomal activation mixture. These cytotoxicity data are in line with observations...

  12. [Peroxide modification of membranes and isomorphic composition of cytochrome P-450 of rat liver microsomes during antioxidant deficiency].

    Gubskiy, Iu I; Paramonova, G I; Boldeskul, A E; Primak, R G; Bogdanova, L A; Zadorina, O V; Litvinova, N V

    1992-01-01

    Lipid peroxidation (LPO), physico-chemical properties of the membranes and isoformic composition of microsomal cytochrome P-450 from the rat liver were studied under conditions of antioxidant insufficiency (AOI) which was modelled by exclusion of alpha-tocopherol from the animals' ration. An insignificant accumulation of microsomal diene conjugates and schiff bases against a sharp increase of the ability to the prooxidant stimulated LPO in vitro took place. A significant decrease of membrane lipid microviscosity and a change in surface properties of microsomal membranes of rats with AOI was determined. Absence of alpha-tocopherol in the ration was accompanied by a significant change in the content of separate isoforms of cytochrome P-450 exhibited in growth of a polypeptide with m. w. 54 kDa and the lowering of proteins with m. w. 48 and 50 kDa. Less intensive quenching of tryptophan fluorescence by acrylamide was also revealed, which testified to a lower accessibility of the quencher to membrane proteins or their fluorophore sites. Modification of lipid composition and of physicochemical properties of the rat liver membrane microsomes which was observed at AOI was significantly correlated by pretreatment with the antioxidant 4-methyl-2,6-ditretbutylphenol (ionol).

  13. Expression of microsomal prostaglandin E synthase-1 in intestinal type gastric adenocarcinoma and in gastric cancer cell lines

    van Rees, Bastiaan P.; Sivula, Anna; Thorén, Staffan; Yokozaki, Hiroshi; Jakobsson, Per-Johan; Offerhaus, G. Johan A.; Ristimäki, Ari

    2003-01-01

    Gastrointestinal carcinomas synthesize elevated levels of prostaglandin E(2) (PGE(2)), which has been mechanistically linked to carcinogenesis. Recently, microsomal prostaglandin E synthase-1 (mPGES-1) was cloned, which seems to be inducible and linked to cyclooxygenase-2 (Cox-2) in the biosynthesis

  14. A reliable radiochromatographic assay technique for hepatic microsomal 16α-hydroxylase activity towards oestrone 3-sulphate

    Tsoutsoulis, C.J.; Hobkirk, R.

    1980-01-01

    A reliable procedure for the assay of liver microsomal 16α-hydroxylation of oestrone 3-sulphate has been developed for the guinea pig. It is based on the rapid, quantitative separation of oestradiol and oestriol by Sephadex LH-20 columns after the chemical reduction and enzymic hydrolysis of the incubation products. Microsomal preparations and incubation conditions that optimized 16α-hydroxylation of oestrone 3-sulphate were employed. Under these circumstances, reduction of the substrate at C-17 and hydrolysis of the sulphate were minimized. Conditions were established that yielded reaction linearity with respect to time and microsomal concentration. This hydroxylation had an absolute requirement for NADPH, which could not be satisfied by NADH. Apparent Ksub(m) values for oestrone 3-sulphate and NADPH, under the conditions used, were 14μM and 0.17mM respectively. 16α-hydroxylase activity was present in the liver microsomal fraction from heavily pigmented, female English Shorthaired guinea pigs. Much lower activity was detected in mature pigmented males and albino females. No activity could be demonstrated in mature, albino males. (author)

  15. RATE AND CAPACITY OF HEPATIC MICROSOMAL RING HYDROXYLATION OF PHENOL TO HYDROQUINONE AND CATECHOL IN RAINBOW TROUT (ONCORHYNCHUS MYKISS)

    Rainbow trout liver microsomes were used to study the rate of ring-hydroxylation of phenol (PH) by directly measuring the production of hydroquinone (HQ), the primary metabolite, and catechol (CAT), a secondary metabolite. An HPLC method with integrated ultroviolet (UV) and elect...

  16. Absence of cross-reactivity to myeloperoxidase of anti-thyroid microsomal antibodies in patients with autoimmune thyroid diseases

    Freire, BA; Paula, ID; Paula, F; Kallenberg, GGM; Limburg, PC; Queluz, TT

    Background: Thyroperoxidase is the major antigen of the thyroid microsomal antibodies (TMA) detected in autoimmune thyroid diseases. Its amino acid sequence has 44% homology with myeloperoxidase (MPO), an enzyme present in the primary granules of neutrophils and one of the major antineutrophil

  17. Validating genetic risk associations for ovarian cancer through the international Ovarian Cancer Association Consortium

    Pearce, C L; Near, A M; Van Den Berg, D J

    2009-01-01

    The search for genetic variants associated with ovarian cancer risk has focused on pathways including sex steroid hormones, DNA repair, and cell cycle control. The Ovarian Cancer Association Consortium (OCAC) identified 10 single-nucleotide polymorphisms (SNPs) in genes in these pathways, which had...... been genotyped by Consortium members and a pooled analysis of these data was conducted. Three of the 10 SNPs showed evidence of an association with ovarian cancer at P... and risk of ovarian cancer suggests that this pathway may be involved in ovarian carcinogenesis. Additional follow-up is warranted....

  18. α-Tocopherol incorporation in mitochondria and microsomes upon supranutritional vitamin E supplementation

    Lauridsen, Charlotte; Jensen, Søren Krogh

    2012-01-01

    Vitamin E (α-tocopherol) is a major lipid-soluble chain-breaking antioxidant in humans and mammals and plays an important role in normal development and physiology. The localization of α-tocopherol within the highly unsaturated phospholipid bilayer of cell membranes provides a means of controlling...... cellular compartments is important in order to maintain oxidative stability of the membrane-bound lipids and prevent damage from the reactive oxygen species. Many studies regarding mitochondrial disease and dysfunction have been performed in relation to deficiency of vitamin E and other antioxidants...... with antioxidants on their incorporation into mitochondria and other cellular membranes. The purpose of this review is therefore to briefly summarize experimental data performed with dietary vitamin E treatments in relation to the deposition of α-tocopherol in mitochondria and microsomes....

  19. Studies on the metabolism of chlorotrianisene to a reactive intermediate and subsequent covalent binding to microsomal proteins

    Juedes, M.J.

    1989-01-01

    The studies on chlorotrianisene were conducted to determine whether metabolism of chlorotrianisene occurs via the cytochrome P450 monooxygenase system and whether a reactive intermediate is being formed that is capable of binding covalently to microsomal proteins. [ 3 H]-chlorotrianisene was incubated with liver microsomes supplemented with NADPH. At the termination of the incubation, the protein was trapped on a glass filter and the unbound chlorotrianisene was removed by extensive washing of the protein with organic solvent. A dramatic stimulation of covalent binding was demonstrated in microsomes from rats treated with methylcholanthrene (60 fold increase) versus control or phenobarbital treatment. Verification of covalent binding was achieved by localization of radiolabeled bands following sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of the macromolecules in the incubation mixture. Further analysis of the radiolabeled macromolecules separated on SDS-PAGE revealed that these macromolecules were degraded by protease degradation indicating that the macromolecules were proteins. Further investigations were done to determine the cause of the dramatic stimulation of covalent binding detected in microsomes from methylcholanthrene treated rats versus control or phenobarbital treated rats. Further evidence for the participation of P-450c was obtained with a reconstituted cytochrome P-450 system. Incubations of chlorotrianisene with reconstituted P-450c and NADPH-cytochrome P-450 reductase exhibited covalent binding characteristics comparable to those seen in microsomal incubations. Investigations into the nature of the binding site and the reactive intermediate are currently being conducted. By analyzing the BSA adduct, the author intends to isolate the specific amino acid binding site(s)

  20. Aerobic Epoxidation of Olefins Catalyzed by the Cobalt‐Based Metal–Organic Framework STA‐12(Co)

    Beier, Matthias Josef; Kleist, Wolfgang; Wharmby, Michael T.

    2012-01-01

    , (E)‐stilbene was converted with high selectivities between 80 and 90 %. Leaching of Co was low and the reaction was found to proceed mainly heterogeneously. The catalyst was reusable with only a small loss of activity. The catalytic epoxidation of stilbene with the MOF featured an induction period...

  1. Benzo(a)pyrene diol epoxides as intermediates in nucleic acid binding in vivo and in vitro

    Weinstein, I.B.; Jeffrey, A.M.; Jennette, K.W.

    1976-01-01

    Evidence has been obtained that a specific isomer of a diol epoxide derivative of benzo(a)pyrene, (+/-)-7 beta,8alpha-dihydroxy-9alpha, 10alpha-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene, is an intermediate in the binding of benzo(a)pyrene to RNA in cultured bovine bronchial mucosa. An adduct is for...

  2. (Salen)Ti(Ⅳ)-Catalyzed Asymmetric Ring-opening of meso Epoxides Using Dithiophosphorus Acid as the Nucleophile

    Zheng Hong ZHOU; Zhao Ming LI; Bing LIU; Kang Ying LI; Li Xin WANG; Guo Feng ZHAO; Qi Lin ZHOU; Chu Chi TANG

    2006-01-01

    The asymmetric ring-opening of epoxides with dithiophosphorus acids catalyzed by a (salen)Ti(Ⅳ) complex formed in situ from the reaction of Ti(OPr-i)4 and the chiral Schiff base derived from (1R,2R)-(+)-diaminocyclohexane was realized. The resulting products were obtained with low to good enantioselectivity (up to 73% ee).

  3. Organic carbonates as solvents in macrocyclic Mn(III) salen catalyzed asymmetric epoxidation of non-functionalized olefins

    Maity, N. Ch.; Rao, G. V. S.; Prathap, Kaniraj Jeya; Abdi, S. H. R.; Kureshy, R. I.; Khan, N. H.; Bajaj, H. C.

    2013-01-01

    Roč. 366, January (2013), s. 380-389 ISSN 1381-1169 Institutional support: RVO:61388963 Keywords : asymmetric epoxidation * organic carbonate * macrocyclic Mn(III) salen complex Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.679, year: 2013

  4. Combination of supramolecular cross-linking with covalent cross-linking through epoxide ring-opening including gel studies

    Hofmeier, H.; El-Ghayoury, A.; Schubert, U.S.

    2003-01-01

    Terpolymers based on poly(methyl methacrylate), containing terpyridine-moieties as well as epoxide groups, were synthesized via free-radical polymeri-zation. The products were cross-linked non-covalently with iron(II) ions and cova-lently by treatment with AlCl3. Both steps could be combined in

  5. Combination of supramolecular cross-linking with covalent cross-linking through epoxide ring-opening including gel studies

    Hofmeier, H.; El-Ghayoury, A.; Schubert, U.S.

    2003-01-01

    Terpolymers based on poly(methyl methacrylate), containing terpyridinemoieties as well as epoxide groups, were synthesized via free-radical polymerization. The products were cross-linked non-covalently with iron(II) ions and covalently by treatment with AlCl3. Both steps could be combined in

  6. Anhydrous ZnCl2: A Highly Efficient Reagent for Facile and Regioselective Conversion of Epoxides to β-Chlorohydrins

    Ronak Eisavi

    2016-01-01

    Full Text Available Facile conversion of structurally different epoxides to the corresponding β-chlorohydrins was carried out successfully with anhydrous ZnCl2 in CH3CN. The reactions were carried out within 10-50 min to give β-chlorohydrins with perfect regioselectivity and high yields (80-97%.

  7. Developmental and growth temperature regulation of two different microsomal omega-6 desaturase genes in soybeans.

    Heppard, E P; Kinney, A J; Stecca, K L; Miao, G H

    1996-01-01

    The polyunsaturated fatty acid content is one of the major factors influencing the quality of vegetable oils. Edible oils rich in monounsaturated fatty acid provide improved oil stability, flavor, and nutrition for human and animal consumption. In plants, the microsomal omega-6 desaturase-catalyzed pathway is the primary route of production of polyunsaturated lipids. We report the isolation of two different cDNA sequences, FAD2-1 and FAD2-2, encoding microsomal omega-6 desaturase in soybeans and the characterization of their developmental and temperature regulation. The FAD2-1 gene is strongly expressed in developing seeds, whereas the FAD2-2 gene is constitutively expressed in both vegetative tissues and developing seeds. Thus, the FAD2-2 gene-encoded omega-6 desaturase appears to be responsible for production of polyunsaturated fatty acids within membrane lipids in both vegetative tissues and developing seeds. The seed-specifically expressed FAD2-1 gene is likely to play a major role in controlling conversion of oleic acid to linoleic acid within storage lipids during seed development. In both soybean seed and leaf tissues, linoleic acid and linolenic acid levels gradually increase as temperature decreases. However, the levels of transcripts for FAD2-1, FAD2-2, and the plastidial omega-6 desaturase gene (FAD 6) do not increase at low temperature. These results suggest that the elevated polyunsaturated fatty acid levels in developing soybean seeds grown at low temperature are not due to the enhanced expression of omega-6 desaturase genes. PMID:8587990

  8. In vitro metabolism of the anti-androgenic fungicide vinclozolin by rat liver microsomes.

    Sierra-Santoyo, Adolfo; Angeles-Soto, Esperanza; de Lourdes López-González, Ma; Harrison, Randy A; Hughes, Michael F

    2012-03-01

    Vinclozolin (V) is a fungicide used in agricultural settings. V administered to rats is hydrolyzed to 2-[[(3,5-dichlorophenyl)-carbamoyl]oxy]-2-methyl-3-butenoic acid (M1) and 3',5'-dichloro-2-hydroxy-2-methylbut-3-enanilide (M2). V, M1 and M2 have antiandrogenic properties by interacting with the androgen receptor. Data on V, M1 and M2 biotransformation are limited. Our objective was to characterize V metabolism by rat liver microsomes. V was incubated with non-treated adult male Long-Evans rat liver microsomes and NADPH. Several metabolites were detected following the extraction of incubate with acetonitrile and analysis by HPLC/DAD/MSD. One metabolite was identified as [3-(3,5-dichlorophenyl)-5-methyl-5-(1,2-dihydroxyethyl)-1,3-oxazolidine-2,4-dione] (M4), which was gradually converted to 3',5'-dichloro-2,3,4-trihydroxy-2-methylbutylanilide (M5). Both co-eluted in the same HPLC peak. Another metabolite ([M7]) was detected by UV but was unstable for mass spectral analysis. The K(M app) for co-eluted M4/M5 and [M7] was 53.7 and 135.4 μM, the V(max app) was 0.812 and 0.669 nmoles/min/mg protein, and CL(int) was 15.1 and 4.9 ml/min/g protein, respectively. Pilocarpine, orphenadrine and proadifen and anti-rat cytochrome P450 (CYP)2A, 2B and 3A antibodies inhibited M4/M5 and [M7] formation. These results indicate that V is efficiently metabolized by CYP. Determination of the metabolites of V will provide further insight into the relationship between toxicity and tissue dose of V and its metabolites.

  9. The Metabolism of Separase Inhibitor Sepin-1 in Human, Mouse, and Rat Liver Microsomes

    Feng Li

    2018-05-01

    Full Text Available Separase, a known oncogene, is widely overexpressed in numerous human tumors of breast, bone, brain, blood, and prostate. Separase is an emerging target for cancer therapy, and separase enzymatic inhibitors such as sepin-1 are currently being developed to treat separase-overexpressed tumors. Drug metabolism plays a critical role in the efficacy and safety of drug development, as well as possible drug–drug interactions. In this study, we investigated the in vitro metabolism of sepin-1 in human, mouse, and rat liver microsomes (RLM using metabolomic approaches. In human liver microsomes (HLM, we identified seven metabolites including one cysteine–sepin-1 adduct and one glutathione–sepin-1 adduct. All the sepin-1 metabolites in HLM were also found in both mouse and RLM. Using recombinant CYP450 isoenzymes, we demonstrated that multiple enzymes contributed to the metabolism of sepin-1, including CYP2D6 and CYP3A4 as the major metabolizing enzymes. Inhibitory effects of sepin-1 on seven major CYP450s were also evaluated using the corresponding substrates recommended by the US Food and Drug Administration. Our studies indicated that sepin-1 moderately inhibits CYP1A2, CYP2C19, and CYP3A4 with IC50 < 10 μM but weakly inhibits CYP2B6, CYP2C8/9, and CYP2D6 with IC50 > 10 μM. This information can be used to optimize the structures of sepin-1 for more suitable pharmacological properties and to predict the possible sepin-1 interactions with other chemotherapeutic drugs.

  10. Impaired rate of microsomal fatty acid elongation in undernourished neonatal rat brain

    Yeh, Y.Y.

    1986-01-01

    Hypomyelination caused by undernourishment in characterized by low concentrations of myelin lipids and marked reduction in lignocerate (C/sub 24:0/) and nervonate (C/sub 24:1/) moiety of cerebroside and sulfatide. Since microsomal elongation is the major source of long chain (22 to 24 carbons) fatty acids in the brain, the effect of neonatal undernourishment on acyl elongation was investigated. Undernourishment of suckling rats were induced after birth by restricting maternal dietary intake to 40% of that consumed by dams fed ad libitum. Neonates suckled by the normally fed dams served as controls. Microsomal elongation was measured as nmol from [2- 14 C] malonyl CoA incorporated/h per mg of protein. At 19 days of age, rates of behenoyl CoA (C/sub 22:0/) and erucoyl CoA (C/sub 22:1/) elongation in whole brain of undernourished neonates were 30-40% lower than that of the control, whereas the elongation rates of acyl CoA 16, 18 and 20 carbons in length either saturated or monounsaturated were similar in both groups. Undernourishment had no effect on cytoplasmic de novo fatty acid synthesis from acetyl CoA. If there are multiple elongation factors, the results indicate that the depressed activity of elongating enzyme(s) for C/sub 22:0/ and C/sub 22:1/ is an important contributing factor in lowering S/sub 24:0/ and C/sub 24:1/ content in cerebroside and sulfatide. This impairment may be a specific lesion leading to hypomyelination in undernourished rats

  11. MV-NIS or Investigator's Choice Chemotherapy in Treating Patients With Ovarian, Fallopian, or Peritoneal Cancer

    2018-04-27

    Fallopian Tube Transitional Cell Carcinoma; Malignant Ovarian Clear Cell Tumor; Malignant Ovarian Endometrioid Tumor; Malignant Ovarian Serous Tumor; Ovarian Seromucinous Carcinoma; Ovarian Transitional Cell Carcinoma; Primary Peritoneal Serous Adenocarcinoma; Recurrent Fallopian Tube Carcinoma; Recurrent Ovarian Carcinoma; Recurrent Primary Peritoneal Carcinoma; Undifferentiated Fallopian Tube Carcinoma; Undifferentiated Ovarian Carcinoma

  12. Modeling of Toxicity-Relevant Electrophilic Reactivity for Guanine with Epoxides: Estimating the Hard and Soft Acids and Bases (HSAB) Parameter as a Predictor.

    Zhang, Jing; Wang, Chenchen; Ji, Li; Liu, Weiping

    2016-05-16

    According to the electrophilic theory in toxicology, many chemical carcinogens in the environment and/or their active metabolites are electrophiles that exert their effects by forming covalent bonds with nucleophilic DNA centers. The theory of hard and soft acids and bases (HSAB), which states that a toxic electrophile reacts preferentially with a biological macromolecule that has a similar hardness or softness, clarifies the underlying chemistry involved in this critical event. Epoxides are hard electrophiles that are produced endogenously by the enzymatic oxidation of parent chemicals (e.g., alkenes and PAHs). Epoxide ring opening proceeds through a SN2-type mechanism with hard nucleophile DNA sites as the major facilitators of toxic effects. Thus, the quantitative prediction of chemical reactivity would enable a predictive assessment of the molecular potential to exert electrophile-mediated toxicity. In this study, we calculated the activation energies for reactions between epoxides and the guanine N7 site for a diverse set of epoxides, including aliphatic epoxides, substituted styrene oxides, and PAH epoxides, using a state-of-the-art density functional theory (DFT) method. It is worth noting that these activation energies for diverse epoxides can be further predicted by quantum chemically calculated nucleophilic indices from HSAB theory, which is a less computationally demanding method than the exacting procedure for locating the transition state. More importantly, the good qualitative/quantitative correlations between the chemical reactivity of epoxides and their bioactivity suggest that the developed model based on HSAB theory may aid in the predictive hazard evaluation of epoxides, enabling the early identification of mutagenicity/carcinogenicity-relevant SN2 reactivity.

  13. Obesity and risk of ovarian cancer subtypes

    Olsen, Catherine M; Nagle, Christina M; Whiteman, David C

    2013-01-01

    Whilst previous studies have reported that higher BMI increases a woman's risk of developing ovarian cancer, associations for the different histological subtypes have not been well defined. As the prevalence of obesity has increased dramatically, and classification of ovarian histology has improv...

  14. Ovarian cancer mortality and industrial pollution

    García-Pérez, Javier; Lope, Virginia; López-Abente, Gonzalo; González-Sánchez, Mario

    2015-01-01

    We investigated whether there might be excess ovarian cancer mortality among women residing near Spanish industries, according to different categories of industrial groups and toxic substances. An ecologic study was designed to examine ovarian cancer mortality at a municipal level (period 1997–2006). Population exposure to pollution was estimated by means of distance from town to facility. Using Poisson regression models, we assessed the relative risk of dying from ovarian cancer in zones around installations, and analyzed the effect of industrial groups and pollutant substances. Excess ovarian cancer mortality was detected in the vicinity of all sectors combined, and, principally, near refineries, fertilizers plants, glass production, paper production, food/beverage sector, waste treatment plants, pharmaceutical industry and ceramic. Insofar as substances were concerned, statistically significant associations were observed for installations releasing metals and polycyclic aromatic chemicals. These results support that residing near industries could be a risk factor for ovarian cancer mortality. - Highlights: • We studied excess mortality due to ovarian cancer near Spanish industries. • Integrated nested Laplace approximations were used as a Bayesian inference tool. • We found excess ovarian cancer mortality near all industrial groups as a whole. • Risk also was found in towns near industries releasing carcinogens and metals. • Risk was associated with plants releasing polycyclic aromatic chemicals and POPs. - Our results support that residing in the vicinity of pollutant industries could be a risk factor for ovarian cancer mortality

  15. Cigarette smoking and risk of ovarian cancer

    Faber, Mette T; Kjær, Susanne K; Dehlendorff, Christian

    2013-01-01

    The majority of previous studies have observed an increased risk of mucinous ovarian tumors associated with cigarette smoking, but the association with other histological types is unclear. In a large pooled analysis, we examined the risk of epithelial ovarian cancer associated with multiple...... measures of cigarette smoking with a focus on characterizing risks according to tumor behavior and histology....

  16. Ovarian damage due to cyst removal

    Perlman, Signe; Kjer, Jens J

    2016-01-01

    INTRODUCTION: Surgical treatment of endometriomas and potential damage to the ovary have been debated. Studies have described the inconsistent risk of unintended removal of ovarian tissue when a cystectomy of an endometrioma is performed. We evaluated the risk of inadvertently removed ovarian tis...

  17. Pathogenesis of ovarian cancer: current perspectives | Chesang ...

    Objective: To present a review of current knowledge of the pathogenesis of ovarian cancer and its clinical implications. Data Source: Extensive literature search was conducted to identify relevant studies. Study Selection: Studies in the English language about or related to pathogenesis of ovarian cancer were selected.

  18. Hormone therapy and ovarian borderline tumors

    Mørch, Lina Steinrud; Løkkegaard, Ellen; Andreasen, Anne Helms

    2012-01-01

    Little is known about the influence of postmenopausal hormone therapy on the risk of ovarian borderline tumors. We aimed at assessing the influence of different hormone therapies on this risk.......Little is known about the influence of postmenopausal hormone therapy on the risk of ovarian borderline tumors. We aimed at assessing the influence of different hormone therapies on this risk....

  19. Statin use and risk for ovarian cancer

    Baandrup, L; Dehlendorff, C; Friis, Søren

    2015-01-01

    BACKGROUND: Limited data suggest that statin use reduces the risk for ovarian cancer. METHODS: Using Danish nationwide registries, we identified 4103 cases of epithelial ovarian cancer during 2000-2011 and age-matched them to 58,706 risk-set sampled controls. Conditional logistic regression....... The inverse association between statin use and mucinous tumours merits further investigation....

  20. Si-Imidazole-HSO4 Functionalized Magnetic Fe3O4 Nanoparticles as an Efficient and Reusable Catalyst for the Regioselective Ring Opening of Epoxides in Water

    Eshagh Rezaee Nezhad

    2016-01-01

    Full Text Available An efficient and simple method for the preparation of Si-Imidazole-HSO4 functionalized magnetic Fe3O4 nanoparticles (Si-Im-HSO4 MNPs and used as an efficient and reusable magnetic catalysts for the regioselective ring opening of epoxides under green conditions in water. This catalyst was used for the ring opening of epoxide corresponding to the thiocyanohydrins and azidohydrines. Compared to the classical ring opening of epoxides, this new method consistently has the advantage of excellent yields, short reaction times, and methodological simplicity.

  1. Ovarian cancer mortality and industrial pollution.

    García-Pérez, Javier; Lope, Virginia; López-Abente, Gonzalo; González-Sánchez, Mario; Fernández-Navarro, Pablo

    2015-10-01

    We investigated whether there might be excess ovarian cancer mortality among women residing near Spanish industries, according to different categories of industrial groups and toxic substances. An ecologic study was designed to examine ovarian cancer mortality at a municipal level (period 1997-2006). Population exposure to pollution was estimated by means of distance from town to facility. Using Poisson regression models, we assessed the relative risk of dying from ovarian cancer in zones around installations, and analyzed the effect of industrial groups and pollutant substances. Excess ovarian cancer mortality was detected in the vicinity of all sectors combined, and, principally, near refineries, fertilizers plants, glass production, paper production, food/beverage sector, waste treatment plants, pharmaceutical industry and ceramic. Insofar as substances were concerned, statistically significant associations were observed for installations releasing metals and polycyclic aromatic chemicals. These results support that residing near industries could be a risk factor for ovarian cancer mortality. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Etiology and Pathogenesis of Epithelial Ovarian Cancer

    Samuel C. Mok

    2007-01-01

    Full Text Available Ovarian cancer is complex disease composed of different histological grades and types. However, the underlying molecular mechanisms involved in the development of different phenotypes remain largely unknown. Epidemiological studies identified multiple exogenous and endogenous risk factors for ovarian cancer development. Among them, an inflammatory stromal microenvironment seems to play a critical role in the initiation of the disease. The interaction between such a microenvironment, genetic polymorphisms, and different epithelial components such as endosalpingiosis, endometriosis, and ovarian inclusion cyst in the ovarian cortex may induce different genetic changes identified in the epithelial component of different histological types of ovarian tumors. Genetic studies on different histological grades and types provide insight into the pathogenetic pathways for the development of different disease phenotypes. However, the link between all these genetic changes and the etiological factors remains to be established.

  3. Massive ovarian edema, due to adjacent appendicitis.

    Callen, Andrew L; Illangasekare, Tushani; Poder, Liina

    2017-04-01

    Massive ovarian edema is a benign clinical entity, the imaging findings of which can mimic an adnexal mass or ovarian torsion. In the setting of acute abdominal pain, identifying massive ovarian edema is a key in avoiding potential fertility-threatening surgery in young women. In addition, it is important to consider other contributing pathology when ovarian edema is secondary to another process. We present a case of a young woman presenting with subacute abdominal pain, whose initial workup revealed marked enlarged right ovary. Further imaging, diagnostic tests, and eventually diagnostic laparoscopy revealed that the ovarian enlargement was secondary to subacute appendicitis, rather than a primary adnexal process. We review the classic ultrasound and MRI imaging findings and pitfalls that relate to this diagnosis.

  4. Targeted Therapies in Epithelial Ovarian Cancer

    Jurjees Hasan

    2010-02-01

    Full Text Available Molecularly targeted therapy is relatively new to ovarian cancer despite the unquestionable success with these agents in other solid tumours such as breast and colorectal cancer. Advanced ovarian cancer is chemosensitive and patients can survive several years on treatment. However chemotherapy diminishes in efficacy over time whilst toxicities persist. Newer biological agents that target explicit molecular pathways and lack specific chemotherapy toxicities such as myelosuppression offer the advantage of long-term therapy with a manageable toxicity profile enabling patients to enjoy a good quality of life. In this review we appraise the emerging data on novel targeted therapies in ovarian cancer. We discuss the role of these compounds in the front-line treatment of ovarian cancer and in relapsed disease; and describe how the development of predictive clinical, molecular and imaging biomarkers will define the role of biological agents in the treatment of ovarian cancer.

  5. Targeted Therapies in Epithelial Ovarian Cancer

    Dean, Emma; El-Helw, Loaie; Hasan, Jurjees, E-mail: jurjees.hasan@christie.nhs.uk [Christie Hospital NHS Foundation Trust / Wilmslow Road, Manchester, M20 4BX (United Kingdom)

    2010-02-23

    Molecularly targeted therapy is relatively new to ovarian cancer despite the unquestionable success with these agents in other solid tumours such as breast and colorectal cancer. Advanced ovarian cancer is chemosensitive and patients can survive several years on treatment. However chemotherapy diminishes in efficacy over time whilst toxicities persist. Newer biological agents that target explicit molecular pathways and lack specific chemotherapy toxicities such as myelosuppression offer the advantage of long-term therapy with a manageable toxicity profile enabling patients to enjoy a good quality of life. In this review we appraise the emerging data on novel targeted therapies in ovarian cancer. We discuss the role of these compounds in the front-line treatment of ovarian cancer and in relapsed disease; and describe how the development of predictive clinical, molecular and imaging biomarkers will define the role of biological agents in the treatment of ovarian cancer.

  6. Ovarian and tubal cancer in Denmark

    Gottschau, Mathilde; Mellemkjaer, Lene; Hannibal, Charlotte G

    2016-01-01

    INTRODUCTION: The Nordic countries are areas with a high-incidence of ovarian cancer; however, differences between the countries exist. MATERIAL AND METHODS: We used the Danish Cancer Registry to identify 11 264 cases of ovarian cancer and 363 cases of tubal cancer during 1993-2013. We calculated...... age-standardized (world standard population) incidence rates for overall and subtype-specific ovarian cancer, and for tubal cancer. We compared age-standardized incidence rates, and 1- and 5-year age-standardized relative survival rates, respectively, for ovarian and tubal cancer combined in four...... Nordic countries using the NORDCAN database. RESULTS: The incidence rate of ovarian cancer overall in Denmark decreased statistically significantly by approximately 2.3% per year among women aged

  7. Combination of natural fiber Boehmeria nivea (ramie) with matrix epoxide for bullet proof vest body armor

    Anggoro, Didi Dwi, E-mail: anggorophd@gmail.com; Kristiana, Nunung, E-mail: nuna.c631@gmail.com [Master of Chemical Engineering, Faculty of Engineering, Diponegoro University Jln. Prof. Sudharto, Tembalang, Semarang, 50239 (Indonesia)

    2015-12-29

    Ballistic protection equipment, such as a bulletproof vest, is a soldier’s most important means of preserving life and survivability in extreme combat conditions. The bulletproof vests are designed to protect the user’s chest from injury without disturbing the ability to perform his duties. Aromatic polyamide or aramid fibers known under the trade name Kevlar, Trawon and so is synthetic fiber materials commonly used in the manufacture of bulletproof vests. This synthetic fibers have high tensile strength and ductility. Kevlar is expensive and imported material. In this study, will introduce local natural raw materials, ramie fiber (Boehmeria nivea) which is cheaper and environmentally friendly. It has enough tenacity and tensile strength as a bulletproof vest. This experiment uses two panels, there are Panel A as front surface of Panel B. Panel A is a combination of ramie and epoxide matrix, while panel B is only ramie. From several variations of experimental combinations between Panel A and Panel B, optimal combination obtained with 16 layers of panel A and 31-34 layers of panel B which is able to protect againts cal. 7.65 mm × 17 mm (.32 ACP) bullet fired through pistol .32 Pindad from a distance of 20 meters. Panel with a size of 20 cm × 20 cm has a total thickness between 12,922 to13,745 mm and a total weight between 506,26 to 520,926gram. Scanning electron microscopy (SEM) observations indicated that the porosity and surface area of the ramie fiber is smooth, fiber surfaces showed topography with micropores. SEM also showed well-arranged structure of fibers bonding. Energy Dispersive X-ray (EDX) analysis indicated 100 % carbon contents in ramie fiber. Test result indicates that panel from composite ramie-epoxide can reach the level 1of International Standard of NIJ - 010104. Compared to panel from polyester fiber, the panel from composite ramie-epoxide (0,50-0,52 kg) is lighter weight than panel polyester fiber (1,642 kg)

  8. Further characterization of benzo[a]pyrene diol-epoxide (BPDE)-induced comet assay effects.

    Bausinger, Julia; Schütz, Petra; Piberger, Ann Liza; Speit, Günter

    2016-03-01

    The present study aims to further characterize benzo[a]pyrene diol-epoxide (BPDE)-induced comet assay effects. Therefore, we measured DNA effects by the comet assay and adduct levels by high-performance liquid chromatography (HPLC) in human lymphocytes and A549 cells exposed to (±)-anti-benzo[a]pyrene-7,8-diol 9,10-epoxide [(±)-anti-BPDE] or (+)-anti-benzo[a]pyrene-7,8-diol 9,10-epoxide [(+)-anti-BPDE]. Both, the racemic form and (+)-anti-BPDE, which is the most relevant metabolite with regard to mutagenicity and carcinogenicity, induced DNA migration in cultured lymphocytes in the same range of concentrations to a similar extent in the alkaline comet assay after exposure for 2h. Nevertheless, (+)-anti-BPDE induced significantly enhanced DNA migration after 16 and 18h post-cultivation which was not seen in response to (±)-anti-BPDE. Combination of the comet assay with the Fpg (formamidopyrimidine-DNA glycosylase) protein did not enhance BPDE-induced effects and thus indicated the absence of Fpg-sensitive sites (oxidized purines, N7-guanine adducts, AP-sites). The aphidicolin (APC)-modified comet assay suggested significant excision repair activity of cultured lymphocytes during the first 18h of culture after a 2 h-exposure to BPDE. In contrast to these repair-related effects measured by the comet assay, HPLC analysis of stable adducts did not reveal any significant removal of (+)-anti-BPDE-induced adducts from lymphocytes during the first 22h of culture. On the other hand, HPLC measurements indicated that A549 cells repaired about 70% of (+)-anti-BPDE-induced DNA-adducts within 22h of release. However, various experiments with the APC-modified comet assay did not indicate significant repair activity during this period in A549 cells. The conflicting results obtained with the comet assay and the HPLC-based adduct analysis question the real cause for BPDE-induced DNA migration in the comet assay and the reliability of the APC-modified comet assay for the

  9. Combination of natural fiber Boehmeria nivea (ramie) with matrix epoxide for bullet proof vest body armor

    Anggoro, Didi Dwi; Kristiana, Nunung

    2015-01-01

    Ballistic protection equipment, such as a bulletproof vest, is a soldier’s most important means of preserving life and survivability in extreme combat conditions. The bulletproof vests are designed to protect the user’s chest from injury without disturbing the ability to perform his duties. Aromatic polyamide or aramid fibers known under the trade name Kevlar, Trawon and so is synthetic fiber materials commonly used in the manufacture of bulletproof vests. This synthetic fibers have high tensile strength and ductility. Kevlar is expensive and imported material. In this study, will introduce local natural raw materials, ramie fiber (Boehmeria nivea) which is cheaper and environmentally friendly. It has enough tenacity and tensile strength as a bulletproof vest. This experiment uses two panels, there are Panel A as front surface of Panel B. Panel A is a combination of ramie and epoxide matrix, while panel B is only ramie. From several variations of experimental combinations between Panel A and Panel B, optimal combination obtained with 16 layers of panel A and 31-34 layers of panel B which is able to protect againts cal. 7.65 mm × 17 mm (.32 ACP) bullet fired through pistol .32 Pindad from a distance of 20 meters. Panel with a size of 20 cm × 20 cm has a total thickness between 12,922 to13,745 mm and a total weight between 506,26 to 520,926gram. Scanning electron microscopy (SEM) observations indicated that the porosity and surface area of the ramie fiber is smooth, fiber surfaces showed topography with micropores. SEM also showed well-arranged structure of fibers bonding. Energy Dispersive X-ray (EDX) analysis indicated 100 % carbon contents in ramie fiber. Test result indicates that panel from composite ramie-epoxide can reach the level 1of International Standard of NIJ - 010104. Compared to panel from polyester fiber, the panel from composite ramie-epoxide (0,50-0,52 kg) is lighter weight than panel polyester fiber (1,642 kg)

  10. Effect of ovarian endometrioma on uterine and ovarian blood flow in infertile women

    El-Mazny A

    2016-11-01

    Full Text Available Akmal El-Mazny, Ahmed Kamel, Wafaa Ramadan, Sherine Gad-Allah, Suzy Abdelaziz, Ahmed M Hussein Department of Obstetrics and Gynecology, Faculty of Medicine, Cairo University, Cairo, Egypt Background: Angiogenesis has been found to be among the most important factors in the pathogenesis of endometriosis. The formation of new blood vessels is critical for the survival of newly implanted endometriotic foci. The use of 3-D power Doppler allows for the demonstration of the dynamic vascular changes that occur during the process of in vitro fertilization (IVF. We aimed to evaluate the effect of ovarian endometrioma on uterine and ovarian blood flow in infertile women. Materials and methods: In a case–control study at a university teaching hospital, 138 women with unilateral ovarian endometrioma scheduled for IVF were compared to 138 women with male-factor or unexplained infertility. In the mid-luteal (peri-implantation phase of the cycle, endometrial thickness, uterine and ovarian artery pulsatility index and resistance index, endometrial and ovarian volume, 3-D power Doppler vascularization index (VI, flow index (FI, and vascularization FI (VFI values were measured in both groups. Results: There were no significant differences (P>0.05 in endometrial thickness, uterine ovarian artery pulsatility index and resistance index, endometrial and ovarian volume, or VI, FI, and VFI between the two groups. Furthermore, the endometrial and ovarian Doppler indices were not influenced by endometrioma size. No significant differences were observed in the ovarian Doppler indices between endometrioma-containing ovaries and contralateral ovaries. Conclusion: Ovarian endometrioma is not associated with impaired endometrial and ovarian blood flows in infertile women scheduled for IVF, and it is not likely to affect endometrial receptivity or ovarian function through a vascular mechanism. Keywords: 3-D power Doppler, endometrioma, IVF, uterine and ovarian blood flow

  11. Autotransplantation of cryopreserved ovarian tissue in 12 women with chemotherapy-induced premature ovarian failure: the Danish experience

    Schmidt, Kirsten Tryde; Rosendahl, Mikkel; Ernst, Erik

    2011-01-01

    To describe a cohort of 12 Danish women who received autotransplantation of frozen-thawed cryopreserved ovarian tissue because of premature ovarian failure after cancer treatment.......To describe a cohort of 12 Danish women who received autotransplantation of frozen-thawed cryopreserved ovarian tissue because of premature ovarian failure after cancer treatment....

  12. Polycystic ovarian disease: animal models.

    Mahajan, D K

    1988-12-01

    The reproductive systems of human beings and other vertebrates are grossly similar. In the ovary particularly, the biochemical and physiologic processes are identical not only in the formation of germ cells, the development of primordial follicles and their subsequent growth to Graafian follicles, and eventual ovulation but also in anatomic structure. In a noncarcinogenic human ovary, hypersecretion of androgen causes PCOD. Such hypersecretion may result from a nonpulsatile, constant elevated level of circulating LH or a disturbance in the action of neurotransmitters in the hypothalamus. In studying the pathophysiology of PCOD in humans, one must be aware of the limitations for manipulating the hypothalamic-pituitary axis. Although the rat is a polytocous rodent, the female has a regular ovarian cyclicity of 4 or 5 days, with distinct proestrus, estrus, and diestrus phases. Inasmuch as PCOD can be experimentally produced in the rat, that species is a good model for studying the pathophysiology of human PCOD. These PCOD models and their validity have been described: (1) estradiol-valerate, (2) DHA, (3) constant-light (LL), and (4) neonatally androgenized. Among these, the LL model is noninvasive and seems superior to the others for study of the pathophysiology of PCOD. The production of the polycystic ovarian condition in the rat by the injection of estrogens or androgens in neonate animals, or estradiol or DHA in adult rats, or the administration of antigonadotropins to these animals all cause a sudden appearance of the persistent estrus state by disturbing the metabolic and physiologic processes, whereas exposure of the adult rat to LL causes polycystic ovaries gradually, similar to what is seen in human idiopathic PCOD. After about 50 days of LL, the rat becomes anovulatory and the ovaries contain thickened tunica albuginea and many atretic follicles, and the tertiary follicles are considerably distended and cystic. The granulosa and theca cells appear normal

  13. Performance of magnetorheological elastomer based green epoxidized natural rubber/sucrose acetate isobutyrate hybrid matrix

    Khairi, Muntaz Hana Ahmad; Amri Mazlan, Saiful; Aziz, Siti Aishah Abdul; Ubaidillah; Tan Shilan, Salihah

    2018-04-01

    This study introduces a sucrose acetate isobutyrate (SAIB) as a novel additive of magnetorheological elastomers (MREs). The MREs utilized an epoxidized natural rubber (ENR) as the matrix and carbonyl iron particles (CIPs) as their filler. The CIPs were fixed at 60 wt%. The viscosity of the compound was observed using a viscometer. Meanwhile, the microstructures were observed by using field emission scanning electron microscope (FESEM). Rheological properties regarding shear storage modulus were measured by using a rheometer (MCR 302, Anton Paar). The experimental results demonstrated that the MREs-based ENR/SAIB had a decrement in their viscosity by 40% reduction. Moreover, the magnetorheological (MR) effect increased by 23% as the increment of magnetic fields. The morphological photograph showed that the CIPs embedded well within the matrix. The fabricated MREs samples were strain dependent, where all MREs samples exhibit the deteriorating trend when increasing the strain amplitude.

  14. Synthesis, Characterization and Epoxidation of cis-Enriched New Polycarbonates Catalyzed by Efficient Organotin Compound

    A. H. Massoudi

    2011-01-01

    Full Text Available Presence of active functional groups on polymer chain is a suitable aspect of polymer structure which allows performing next favourite reactions on polymer molecule. In this research a novel aromatic derivative of cis-but-2-endiol was synthesized as monomer. The synthesized monomer was polymerized using diphenyl carbonate and 1,4-butandiol as second and third monomer along with organotin catalyst. Polymerization reaction performed by using melt-phase transesterification process to produce a new terpolymer of polycarbonate. During the reaction the double bonds are preserved on polymer chain and epoxidized by m-chloroperbenzoic acid (MCBPA in good yield to demonstrate the reactivity and possibility of performing further reactions on double bonds of polymer.

  15. Effect of epoxidation on 30% poly(methyl methacrylate)-grafted natural rubber polymer electrolytes

    Nazir, Khuzaimah; Aziz, Ahmad Fairoz [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Adam, Nurul Ilham [Faculty of Applied Sciences, Universiti Teknologi MARA, KampusTapah, 35400 Tapah Road, Tapah, Perak (Malaysia); Yahya, Muhd Zu Azhan [Faculty of Defence Sciences and Technology, Universiti Pertahanan Nasional Malaysia, Kem Sungai Besi, 57000 Kuala Lumpur (Malaysia); Ali, Ab Malik Marwan [Institute of Science, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia)

    2015-08-28

    Epoxidized 30% poly(methyl methacrylate)-grafted natural rubber (EMG 30) as a polymer host in solid polymer electrolytes (SPEs) has been investigated. EMG30 was synthesized via performicepoxidation method onto 30% poly(methyl methacrylate)-grafted natural rubber (MG30) and the formations of epoxy group were discussed. The EMG30 were characterized by proton nuclear magnetic resonance ({sup 1}HNMR) to investigate their chemical structure and differential scanning calorimeter to determine their crystallinity. A new peak in {sup 1}HNMR spectra (2.71 ppm) confirmed the appearance of epoxy group. SPE based on EMG30 doped with 40 wt% LiCF{sub 3}SO{sub 3} show the highest conductivity. The complexation between EMG30 and LiCF{sub 3}SO{sub 3} were confirmed by attenuated total reflection Fourier transform infrared (ATR-FTIR)

  16. Effect of epoxidation on 30% poly(methyl methacrylate)-grafted natural rubber polymer electrolytes

    Nazir, Khuzaimah; Aziz, Ahmad Fairoz; Adam, Nurul Ilham; Yahya, Muhd Zu Azhan; Ali, Ab Malik Marwan

    2015-01-01

    Epoxidized 30% poly(methyl methacrylate)-grafted natural rubber (EMG 30) as a polymer host in solid polymer electrolytes (SPEs) has been investigated. EMG30 was synthesized via performicepoxidation method onto 30% poly(methyl methacrylate)-grafted natural rubber (MG30) and the formations of epoxy group were discussed. The EMG30 were characterized by proton nuclear magnetic resonance ( 1 HNMR) to investigate their chemical structure and differential scanning calorimeter to determine their crystallinity. A new peak in 1 HNMR spectra (2.71 ppm) confirmed the appearance of epoxy group. SPE based on EMG30 doped with 40 wt% LiCF 3 SO 3 show the highest conductivity. The complexation between EMG30 and LiCF 3 SO 3 were confirmed by attenuated total reflection Fourier transform infrared (ATR-FTIR)

  17. Effect of epoxidation on 30% poly(methyl methacrylate)-grafted natural rubber polymer electrolytes

    Nazir, Khuzaimah; Aziz, Ahmad Fairoz; Adam, Nurul Ilham; Yahya, Muhd Zu Azhan; Ali, Ab Malik Marwan

    2015-08-01

    Epoxidized 30% poly(methyl methacrylate)-grafted natural rubber (EMG 30) as a polymer host in solid polymer electrolytes (SPEs) has been investigated. EMG30 was synthesized via performicepoxidation method onto 30% poly(methyl methacrylate)-grafted natural rubber (MG30) and the formations of epoxy group were discussed. The EMG30 were characterized by proton nuclear magnetic resonance (1HNMR) to investigate their chemical structure and differential scanning calorimeter to determine their crystallinity. A new peak in 1HNMR spectra (2.71 ppm) confirmed the appearance of epoxy group. SPE based on EMG30 doped with 40 wt% LiCF3SO3 show the highest conductivity. The complexation between EMG30 and LiCF3SO3 were confirmed by attenuated total reflection Fourier transform infrared (ATR-FTIR).

  18. Zirconium(IV)-Catalyzed Ring Opening of on-DNA Epoxides in Water.

    Fan, Lijun; Davie, Christopher P

    2017-05-04

    DNA-encoded library technology (ELT) has spurred wide interest in the pharmaceutical industry as a powerful tool for hit and lead generation. In recent years a number of "DNA-compatible" chemical modifications have been published and used to synthesize vastly diverse screening libraries. Herein we report a newly developed, zirconium tetrakis(dodecyl sulfate) [Zr(DS) 4 ] catalyzed ring-opening of on-DNA epoxides in water with amines, including anilines. Subsequent cyclization of the resulting on-DNA β-amino alcohols leads to a variety of biologically interesting, nonaromatic heterocycles. Under these conditions, a library of 137 million on-DNA β-amino alcohols and their cyclization products was assembled. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Thermoset coatings from epoxidized sucrose soyate and blocked, bio-based dicarboxylic acids.

    Kovash, Curtiss S; Pavlacky, Erin; Selvakumar, Sermadurai; Sibi, Mukund P; Webster, Dean C

    2014-08-01

    A new 100% bio-based thermosetting coating system was developed from epoxidized sucrose soyate crosslinked with blocked bio-based dicarboxylic acids. A solvent-free, green method was used to block the carboxylic acid groups and render the acids miscible with the epoxy resin. The thermal reversibility of this blocking allowed for the formulation of epoxy-acid thermoset coatings that are 100% bio-based. This was possible due to the volatility of the vinyl ethers under curing conditions. These systems have good adhesion to metal substrates and perform well under chemical and physical stress. Additionally, the hardness of the coating system is dependent on the chain length of the diacid used, making it tunable. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Soluble Epoxide Hydrolase Inhibitory Activity of Selaginellin Derivatives from Selaginella tamariscina

    Jang Hoon Kim

    2015-12-01

    Full Text Available Selaginellin derivatives 1–3 isolated from Selaginella tamariscina were evaluated for their inhibition of soluble epoxide hydrolase (sEH to demonstrate their potential for the treatment of cardiovascular disease. All selaginellin derivatives (1–3 inhibited sEH enzymatic activity and PHOME hydrolysis, in a dose-dependent manner, with IC50 values of 3.1 ± 0.1, 8.2 ± 2.2, and 4.2 ± 0.2 μM, respectively. We further determined that the derivatives function as non-competitive inhibitors. Moreover, the predicted that binding sites and interaction between 1–3 and sEH were solved by docking simulations. According to quantitative analysis, 1–3 were confirmed to have high content in the roots of S. tamariscina; among them, selaginellin 3 exhibited the highest content of 189.3 ± 0.0 μg/g.

  1. Investigation on magnetic field dependent modulus of epoxidized natural rubber based magnetorheological elastomer

    Yunus, N. A.; Mazlan, S. A.; Ubaidillah; Aziz, S. A. A.; Khairi, M. H. Ahmad; Wahab, N. A. A.; Shilan, S. T.

    2016-01-01

    This paper presents an investigation on the use of epoxidized natural rubber (ENR) as a matrix of magnetorheological elastomers (MREs). Isotropic ENR-based MRE samples were synthesized by homogeneously mixed the ENR compound with carbonyl iron particles (CIPs). The microstructure of the sample was observed, and the magnetic field-dependent moduli were analyzed using rheometer. The influences of excitation frequency, CIPs content and magnetic field on the field-dependent moduli of ENR-based MREs were evaluated through dynamic shear test. The microstructure of MRE samples demonstrated the dispersed CIPs in the ENR matrix. The remarkable increment of storage and loss moduli of the ENR-based MREs has exhibited the magnetically controllable storage and loss moduli of the samples when exposed to the magnetic field. Consequently, the CIPs content, frequency and magnetic field were significantly influenced the dynamic moduli of the ENR-based MREs. (paper)

  2. Reaction of biscyclopentadienyl molybdendihalides with tert.-butyl hydroperoxide and its using for cyclohexene epoxidation

    Aleksandrov, Yu.A.; Fomin, V.M.; Kolmakov, A.O.

    1983-01-01

    As a result of reactions of biscyclopentadienyl molybden-dihalides (Cp 2 MoX 2 , X=Cl, Br or I) with tert.-butyl hydroperoxide, tert.-butylperoxides of biscyclopentadienyl molybdendichloride and-dibromide are synthesized for the first time, which are characterized by physico-chemical properties. Cyclohexene in the reaction mixture of Cp 2 MoX 2 with tert -butyl hydroperoxide is oxidated to form cyclohexene oxide, the reaction proceeding at a high rate and with a quantitative yield. Tert.-butylperoxide of biscyclopentadienyl molybdendihalide is responsible for the cyclohexene epoxidation reaction. The schemes for the mechanism of Cp 2 MoX 2 reactions with tert.-butyl hydroperoxide in the absence and presence of olefine are suggested

  3. Extremely efficient crystallization of HKUST-1 and Keggin-loaded related phases through the epoxide route.

    Oestreicher, Víctor; Jobbágy, Matías

    2017-03-25

    Highly crystalline HKUST-1 and COK-16-like phases were obtained based on a mild in situ alkalinization one-pot epoxide driven method. A slurry composed of finely ground trimesic acid, H 3 BTC, dispersed in a CuCl 2 aqueous solution quantitatively developed well crystallized HKUST-1 after the addition of propylene oxide. The use of solid H 3 BTC ensures a low concentration of free linker, favoring crystalline growth over the precipitation of amorphous or metastable impurities. An extreme space-time yield of 2.1 × 10 5 kg m -3 day -1 was reached, with no linker excess and minimum use of solvent. The method was equally efficient in the achievement of pure NENU/COK-16 phases, containing [PW 12 O 40 ] 3- , [PMo 12 O 40 ] 3- and [SiMo 12 O 40 ] 4- polyoxometalates.

  4. FTIR and morphology of liquid epoxidized natural rubber acrylate (LENRA)/silica hybrid composites

    Eda Yuhana Ariffin; Azizan Ahmad; Dahlan Mohd; Mahathir Mohamed

    2009-01-01

    Synthesis of organic-inorganic hybrid composites was carried out by combination of liquid epoxidized natural rubber acrylate (LENRA) and silica. Silica was introduce to the matrix by sol gel technique. The sol-gel technique was employed to prepare silica using tetraethyorthosilicate (TEOS) as precursor. HDDA and irga cure 184 were added to the formulations as reactive diluents and photosensitizer, respectively. The chemical modification was studied by Fourier Transform Infrared (FTIR) and energy dispersive X-ray analysis (EDAX). The morphological studies were conducted by the optical and scanning electron microscopes (SEM). It shows that silica was dispersed very well in the matrix for lower concentration of TEOS while agglomeration occurs at the higher concentration. The average particles size of silica were less than 100 nm. (Author)

  5. Ovarian transposition in young women and fertility sparing.

    Mossa, B; Schimberni, M; Di Benedetto, L; Mossa, S

    2015-09-01

    Ovarian transposition is a highly effective surgical procedure used to preserve ovarian function in premenopausal patients with cancers requiring postoperative or primary pelvic radiotherapy. Pelvic irradiation determines severe damage of ovarian DNA and iatrogenic ovarian failure with premature menopause, necessity of long-term hormone replacement therapy and infertility. We conducted an extensive research of the literature in Medline between January 2000 and April 2015 using the key-words "ovarian transposition radiotherapy", "radiotherapy gonadal function", radiotherapy fertility sparing". The population included young women with normal ovarian function affected by cancers that required pelvic radiotherapy. We have examined 32 articles reporting on 1189 women undergoing ovarian transposition. Median age was 32.5 years, follow up was median 48 months. The procedure has been performed in patients less than 40 years of age. Surgery has been achieved by laparotomy or laparoscoy. We have analyzed effects of radiotherapy on ovarian function. The proportion of women treated by ovarian transposition preserved ovarian function was 70%. About 86% of patients did not develop ovarian cysts and in 98-99% of cases did not occur any metastatic disease. Ovarian transposition is associated with significant preservation of ovarian function and a low frequency of complications as cysts and metastasis. In 31% of cases the procedure can fail. Further studies are needed to evaluate the efficacy of ovarian transposition and the follow up. Ovarian transposition should be discussed at the time of cancer diagnosis in every premenopausal woman requiring pelvic radiotherapy.

  6. Epoxide hydrolase-catalyzed enantioselective conversion of trans-stilbene oxide: Insights into the reaction mechanism from steady-state and pre-steady-state enzyme kinetics

    Archelas, A.; Zhao, W.; Faure, B.; Iacazio, G.; Kotík, Michael

    2016-01-01

    Roč. 591, FEB 2016 (2016), s. 66-75 ISSN 0003-9861 Institutional support: RVO:61388971 Keywords : Catalytic mechanism * Epoxide hydrolase * Electrophilic catalysis Subject RIV: CE - Biochemistry Impact factor: 3.165, year: 2016

  7. Persistent ovarian masses and pregnancy outcomes.

    Goh, William A; Rincon, Monica; Bohrer, Justin; Tolosa, Jorge E; Sohaey, Roya; Riaño, Rene; Davis, James; Zalud, Ivica

    2013-07-01

    To determine if persistent ovarian masses in pregnancy are associated with increased adverse outcomes. This is a retrospective cohort of 126 pregnant women with a persistent ovarian mass measuring 5 cm or greater who delivered at two university hospitals between 2001 and 2009. Maternal outcomes included gestational age (GA) at diagnosis, delivery and surgery as well as miscarriage, preterm birth (PTB), ovarian torsion and hospital admission for pain. Neonatal outcomes included birth weight, respiratory distress syndrome (RDS), intra-ventricular hemorrhage (IVH), death and sepsis. A total of 1225 ovarian masses were identified (4.9%) in 24,868 patients. A persistent ovarian mass was found in 0.7%. Average GA at diagnosis was 17.8 weeks. Miscarriage rate was 3.3%. Average GA at delivery was 37.9 weeks. Of the patients, 8.5% had ovarian torsion, 10.3% had admission for pain and 9.3% had PTBs. The mean cesarean delivery rate was 46.3%. The average neonatal weight was 3273 g. There was one neonatal death in this cohort. The rate of RDS was 2.8%, IVH 0.9% and neonatal sepsis 1.9%. The most common surgical pathologic diagnosis was dermoids (37.6%). No overt malignancies were seen. A persistent ovarian mass in pregnancy does not confer an increased risk of adverse pregnancy outcomes.

  8. Diminished ovarian reserve in patients with psoriasis

    Burcu Tuğrul Ayanoğlu

    2018-04-01

    Full Text Available Objective: Psoriasis is a multi-systemic chronic inflammatory skin disease. Previous data suggests that women with some chronic inflammatory diseases have diminished ovarian reserve. This study explores ovarian reserve in patients with psoriasis. Materials and methods: We prospectively analyzed 14 female patients with psoriasis and 35 healthy age and body mass index matched controls. An interview explored demographic characteristics, obstetrical history and menstrual characteristics. Psoriatic area severity index (PASI in patients was assessed. Estrogen, follicle-stimulating hormone (FSH, luteinizing hormone (LH, thyroid stimulating hormone and with gynecologic ultrasonography, ovarian volume and antral follicular count (AFC were measured in both study and control groups. These values were analyzed with changes of the PASI in the patient group. Results: Patients with psoriasis had significantly higher levels of FSH and FSH/LH ratio than healthy controls (p = 0.039, p = 0.005 respectively. AFC of psoriasis patients were significantly lower than healthy controls (p = 0.002.There were no significant difference among other hormone levels and ovarian volumes (p > 0.05. The hormone levels, ovarian volume and AFC were not correlated with PASI of the patients. Conclusion: The results of the study suggest that patients with psoriasis may have diminished ovarian reserve. Keywords: Psoriasis, Ovarian reserve, Psoriatic area severity index, Antral follicular count, Follicle-stimulating hormone

  9. An incidental ovarian mass: A case of ovarian hemangioma with prominent stromal luteinization

    Babak Shirazi

    2015-01-01

    Full Text Available Ovarian hemangioma is a rare benign tumor of female genital tract. Stromal luteinization in ovarian hemangioma is an uncommon process and the pathogenesis is controversial. In this regard, two hypotheses have been suggested whether luteinization is a reactive process or it is the stimulator for development of ovarian hemangioma. Here, we report a case of a 55-year-old woman who referred to our center due to incidental finding of left ovarian mass in pelvic sonography. Microscopically, the mass showed a mixed cavernous and capillary hemangioma and the peripheral stroma contained several small and large clusters of stromal cells, which were luteinized. It should be noted that an ovarian hemangioma could be associated with stromal luteinization although its pathogenesis is not clearly known. Yet, we believe the stromal luteinization around ovarian hemangioma could be a reactive phenomenon.

  10. Tubal ligation and salpingectomy and the risk of epithelial ovarian cancer and borderline ovarian tumors

    Madsen, C; Baandrup, Louise; Dehlendorff, Christian

    2015-01-01

    OBJECTIVE: According to the recent theories on the ovarian cancer origin, any protective effect of tubal ligation may vary with histologic subtype of ovarian cancer. Furthermore, bilateral salpingectomy may represent an opportunity for surgical prevention of serous ovarian cancer. DESIGN: Nationw......OBJECTIVE: According to the recent theories on the ovarian cancer origin, any protective effect of tubal ligation may vary with histologic subtype of ovarian cancer. Furthermore, bilateral salpingectomy may represent an opportunity for surgical prevention of serous ovarian cancer. DESIGN...... sampling. We required that cases and controls have no previous cancer and that controls have no previous bilateral oophorectomy. METHODS: Conditional logistic regression was used to estimate odds ratios and 95% confidence intervals, adjusting for potential confounders. MAIN OUTCOME MEASURES: Epithelial...

  11. The effect of ghee (clarified butter) on serum lipid levels and microsomal lipid peroxidation.

    Sharma, Hari; Zhang, Xiaoying; Dwivedi, Chandradhar

    2010-04-01

    Ghee, also known as clarified butter, has been utilized for thousands of years in Ayurveda as a therapeutic agent. In ancient India, ghee was the preferred cooking oil. In the last several decades, ghee has been implicated in the increased prevalence of coronary artery disease (CAD) in Asian Indians due to its content of saturated fatty acids and cholesterol and, in heated ghee, cholesterol oxidation products. Our previous research on Sprague-Dawley outbred rats, which serve as a model for the general population, showed no effect of 5 and 10% ghee-supplemented diets on serum cholesterol and triglycerides. However, in Fischer inbred rats, which serve as a model for genetic predisposition to diseases, results of our previous research showed an increase in serum total cholesterol and triglyceride levels when fed a 10% ghee-supplemented diet. In the present study, we investigated the effect of 10% dietary ghee on microsomal lipid peroxidation, as well as serum lipid levels in Fischer inbred rats to assess the effect of ghee on free radical mediated processes that are implicated in many chronic diseases including cardiovascular disease. Results showed that 10% dietary ghee fed for 4 weeks did not have any significant effect on levels of serum total cholesterol, but did increase triglyceride levels in Fischer inbred rats. Ghee at a level of 10% in the diet did not increase liver microsomal lipid peroxidation or liver microsomal lipid peroxide levels. Animal studies have demonstrated many beneficial effects of ghee, including dose-dependent decreases in serum total cholesterol, low density lipoprotein (LDL), very low density lipoprotein (VLDL), and triglycerides; decreased liver total cholesterol, triglycerides, and cholesterol esters; and a lower level of nonenzymatic-induced lipid peroxidation in liver homogenate. Similar results were seen with heated (oxidized) ghee which contains cholesterol oxidation products. A preliminary clinical study showed that high doses of

  12. Genetics of polycystic ovarian syndrome.

    Fratantonio, Enza; Vicari, Enzo; Pafumi, Carlo; Calogero, Aldo E

    2005-06-01

    Polycystic ovarian syndrome (PCOS) is a reproductive system disorder characterized by irregular menses, anovulation, clinical and/or biochemical signs of hyperandrogenism (hirsutism and/or acne), ovarian micropolycystic appearance and metabolic abnormalities, such as hyperinsulinaemia and obesity. The aetiopathogenesis of this syndrome is not well known. Several pathogenetic hypotheses have been proposed to explain the full array of symptoms and signs, but with elusive results. A genetic abnormality causing PCOS is supported by the observation that different members of the same family are often affected, and about half of the sisters of PCOS women have elevated serum testosterone concentrations. Therefore, the presence of gene abnormalities in women with PCOS has been widely explored in the attempt to establish whether their mutations or polymorphisms may cause PCOS. The main genes evaluated are those involved in steroidogenesis, steroid hormone effects, gonadotrophin release regulation and action, insulin secretion and action, and adipose tissue metabolism. Despite the vast body of literature produced, none of the genes evaluated seems to play a key role in PCOS pathogenesis. It is likely that PCOS may represent the final outcome of different, deeply inter-related genetic abnormalities that influence each other and perpetuate the syndrome.

  13. Heterogeneous catalytic epoxidation of C/sub 8/-C/sub 1/4 olefins by tert. -butyl hydroperoxide

    Dahlmann, J; Hoeft, E; Boeden, H F; Dilcher, H

    1979-09-01

    Heterogeneous catalytic epoxidation of C/sub 8/-C/sub 14/ olefins by tert.-butyl hydroperoxide (TBHP) avoids large product losses to side reactions, associated with the use of homogeneous catalysts, such as Mo(CO)/sub 6/. With an unsupported MoO/sub 3/ catalyst, 48% TBHP conversion was achieved after one hour (vs. 24% after two hours for Mo(CO)/sub 6/) in 1-octene epoxidation at 90/sup 0/C and 2:1:3 octene/TBHP/toluene (solvent) molar ratio. The use of silica-supported catalysts, such as Bi/sub 9/PMo/sub 12/O/sub 52//30% SiO/sub 2/ (ACN, an industrial catalyst for acrylonitrile), MoO/sub 3//30% SiO/sub 2/ (D-1), 3MoO/sub 3/-Sb/sub 2/O/sub 5//50% SiO/sub 2/ (D-2), or 2MoO/sub 3/-As/sub 2/O/sub 3//50% SiO/sub 2/ (D-3) increased the conversion to 68, 67, 70, and 73%, respectively, with up to 95-99% selectivities for the epoxide. Under optimum conditions of 3:1 olefin/TBHP, 110/sup 0/C, and 2-4 g/l. catalyst, TBHP conversions in epoxidation of 1-tetradecene in a batch reactor over ACN, D-2, and D-3 after two hours were 94, 88, and 91%, respectively, but they decreased to 52, 78, and 79%, respectively, after five two-hour operating cycles. In epoxidation of 1-decene or a mixture of decene isomers (a model for the industrial olefin mixtures obtained by paraffin dehydrogenation via the Parex process) carried out in a continuous flow reactor over the D-3 catalyst at 90/sup 0/-110/sup 0/C, stable catalytic activities with TBHP conversions of approx. 90% and 90-96% selectivities for epoxides were observed for about 900 hr.

  14. Role of keto–enol tautomerization in a chiral phosphoric acid catalyzed asymmetric thiocarboxylysis of meso-epoxide: a DFT study

    Ajitha, Manjaly John; Huang, Kuo-Wei

    2015-01-01

    The mechanism of a chiral phosphoric acid catalyzed thiocarboxylysis of meso-epoxide was investigated by density functional theory (DFT) calculations (M06-2X). The nucleophilic ring opening of epoxide by thiobenzoic acid was found to proceed via a concerted termolecular transition state with a simultaneous dual proton transfer to yield the β-hydroxy thioester product. Electrostatic interactions together with the steric environment inside the chiral catalyst play an important role in determining the enantioselectivity of the reaction.

  15. Role of keto–enol tautomerization in a chiral phosphoric acid catalyzed asymmetric thiocarboxylysis of meso-epoxide: a DFT study

    Ajitha, Manjaly John

    2015-09-15

    The mechanism of a chiral phosphoric acid catalyzed thiocarboxylysis of meso-epoxide was investigated by density functional theory (DFT) calculations (M06-2X). The nucleophilic ring opening of epoxide by thiobenzoic acid was found to proceed via a concerted termolecular transition state with a simultaneous dual proton transfer to yield the β-hydroxy thioester product. Electrostatic interactions together with the steric environment inside the chiral catalyst play an important role in determining the enantioselectivity of the reaction.

  16. SUPRESSION OF MICROSOMAL OXIDATION WEAKENS HISTOCHROME’S DIURETIC EFFECT AT RATS

    O. S. Talalaeva

    2013-01-01

    Full Text Available Histochrome is the medicinal form of echinochrome (2, 3, 5, 6, 8-pentahydroxy-7-ethyl-1,4-naphthoquinone. Arisen during clinical application of the drug questions concerning its biotransformation have predetermined the aim of this research: to study participation liver monooxygenase system in maintenance of histochrome’s pharmacological activity.Simple and informative method of the lifetime control of liver monooxygenase systems influence on a metabolism of a medical product is the estimation of changes of pharmacological effect of a r esearched preparation on a background microsomal oxidations i nhibitor. In experiments on rats chloramphenicol action on diuretic effect of histochrome, as the most convenient for screening, was i nvestigated.To control group of animals during 10 days were hypodermically entered by histochrome in a doze of 10 mg/kg (n = 15. Experimental animals preliminary oral received 50 mg/kg of chloramphenicol before three hours of histochrome introduction (n = 16. In both groups of animals measured volume daily excretion of water, creathinin, sodium and potassium ions excretions in experimental rats each two days. The initial level of parameters of excretory kidneys functions were estimated before introduction of preparations at animals.Long-term histochrome’s injection was followed by a fivefold increasing of water excretion and simultaneously creathinin growth one. Allocation of ions of sodium was statistically significantly increased by 11-th day of experiment, and potassium ions – since the ninth day of histochrome injection. In conditions preliminary chloramphenicol applications volume daily daily urine output and creathinin excretion were essentially less control parameters. Allocation with urine of ions of sodium was decreased almost twice in comparison with the values, fixed at introduction histochrome. Excretion potassium ions ware corresponded to an initial level during all period of supervision.Taking into

  17. Phospholipid fatty acids in mitochondria and microsomes of wheat and rice seedling roots during aeration and anaerobiosis

    Chirkova, T.V.; Sinyutina, N.F.; Blyudzin, Yu.A.; Barskii, I.E.; Smetannikova, S.V.

    1989-01-01

    Mitochondrial and microsomal fractions were isolated from the roots after residence of wheat and rice seedlings under conditions of aeration or anaerobiosis and used to determine the percentage ratio of phospholipid fatty acids (PFA), their content, and the rate of incorporation of [2- 14 C]-acetate into them. In rice mitochondria under anaerobic influence, the ratio of unsaturated to saturated PFA was higher than the level that occurred in the control plants and PFA content remained close to the control level throughout the entire course of exposure. On the other hand, these indices declined in wheat mitochondria and microsomes of both plants. Anoxia also powerfully inhibited incorporation of labelled acetate into PFA of both membrane fractions in wheat and rice seedlings alike. Probably indicating adaptive reorganizations in composition of the main groups of PFA and inhibition of their decomposition in rice mitochondria, the obtained data are discussed in relation to greater resistance to temporary anaerobiosis in rice as compared with wheat

  18. Petroleum distillates suppress in vitro metabolic activation: higher [S-9] required in the Salmonella/microsome mutagenicity assay.

    Carver, J H; Machado, M L; MacGregor, J A

    1985-01-01

    To determine if standard conditions used in the Salmonella/mammalian microsome mutagenicity assay could reliably screen complex petroleum samples, two high-boiling (700-1,070 degrees F) distillates and their separated aromatic fractions were tested. The initial mutagenic activities were inconsistent with the samples' known polyaromatic hydrocarbon (PAH) contents and observed potencies in a dermal carcinogenesis bioassay. A significant mutagenic response was observed only at S-9 concentrations 5 to 10 times higher than those used in the standard assay, supporting the use of elevated levels of S-9 in the Salmonella/microsome assay to assess the carcinogenic potential of petroleum-derived materials. All four samples masked the expected mutagenic activity of added PAHs (benzo[a]pyrene and perylene). Data suggested that petroleum distillates suppress the functional efficacy of the S-9; possible mechanisms are discussed.

  19. Ovarian failure following abdominal irradiation in childhood

    Shalet, S.M.; Beardwell, C.G.; Jones, P.H.M.; Pearson, D.; Orrell, D.H.

    1976-01-01

    Ovarian function was studied in 18 female patients treated for abdominal tumours during childhood. All received abdominal radiotherapy as part of their treatment and were studied between 1 and 26 years after irradiation. The serum gonadotrophins and oestradiol levels were consistent with ovarian failure in each case and there was a disproportionate elevation in serum follicle stimulating hormone (FSH) when compared to serum luteinizing hormone (LH) in 16. In 2 patients, the radiotherapeutic field extended downwards only as far as the sacral promontory. However, these 2 girls show similar evidence of ovarian failure to that in the other 16. (author)

  20. Elevated progesterone during ovarian stimulation for IVF

    Al-Azemi, M; Kyrou, D; Kolibianakis, E M

    2012-01-01

    of Medline and PubMed were searched to identify relevant publications. Good-quality evidence supports the negative impact on endometrial receptivity of elevated progesterone concentrations at the end of the follicular phase in ovarian stimulation. Future trials should document the cause and origin...... phase in ovarian stimulation. The databases of Medline and PubMed were searched to identify relevant publications. Good-quality evidence supports the negative impact on endometrial receptivity of elevated progesterone concentrations at the end of follicular phase in ovarian stimulation. Future trials...

  1. Catalytic Efficiency of Titanium Dioxide (TiO2) and Zeolite ZSM-5 Catalysts in the in-situ Epoxidation of Palm Olein

    Yunus, M. Z. Mohd; Jamaludin, S. K.; Abd. Karim, S. F.; Gani, A. Abd; Sauki, A.

    2018-05-01

    Titanium dioxide and zeolite ZSM-5 are the commonly used heterogeneous catalysts in many chemical reactions. They have several advantages such as low cost and environmental friendly. In this study, titanium dioxide and zeolite ZSM-5 act as catalyst in the in-situ epoxidation of palm olein. Epoxidation of palm olein was carried out by using in-situ generated performic acid to produce epoxidized palm olein in a semi-batch reactor at different temperatures (45°C and 60°C) and agitation speed of 400 rpm. The effects of both catalysts are studied to compare their efficiency in catalyzing the in-situ epoxidation. Epoxidized palm olein was analyzed by using percent of relative conversion to oxirane (RCO%) and fourier transform infrared spectroscopy (FTIR). Surface area of the catalysts used were then characterized by using BET. The results indicated that titanium dioxide is a better catalyst in the in-situ epoxidation of palm olein since it provides higher RCO% compared to Zeolite ZSM-5 at 45°C.

  2. In vitro inactivation of hepatic microsomal phospholipase A/sub 2/ by the marine natural product manoalide

    Master, M.M.; Jacobs, R.S.

    1986-03-01

    The effects of manoalide (MLD) and several analogs (isolated from the sponge Luffariella variabilis) on mouse hepatic microsomal phospholipase A/sub 2/ (PLA/sub 2/) activity was investigated. Microsomal PLA/sub 2/, a membrane bound, Ca/sup + +/ dependent enzyme with an alkaline pH optimum, functions in intracellular phospholipid turnover. In vitro PLA/sub 2/ activity was assayed by preincubating MLD or analogs (2.5-100..mu..M) with microsomes for 60 min. at 37/sup 0/C, combining this mixture with /sup 14/C-phosphatidylcholine and CaCl/sub 2/, and incubating at 37/sup 0/C for 40 minutes. Enzyme activity was quantitated by measurement of the extracted /sup 14/C-arachidonic acid product. MLD inhibited PLA/sub 2/ in a dose-dependent manner, with an IC/sub 50/ = 94..mu..M. Lineweaver-Burk analysis suggests that MLD inhibits PLA/sub 2/ noncompetitively. One of the analogs, producing a comparable dose-response curve to MLD, was found to be more potent (IC/sub 50/ = 33..mu..M). Another analog facilitated PLA/sub 2/ activity (15%) at 25..mu..M, followed by inactivation at higher doses (IC/sub 50/ > 100 ..mu..M). Facilitation of PLA/sub 2/ activity was seen with concentrations as low as 2.5..mu..M of a third analog, and significant inactivation of PLA/sub 2/ was evident. These results indicate that MLD is not as potent against microsomal PLA/sub 2/ as has been shown with purified bee venom and cobra venom PLA/sub 2/'s.

  3. Metabolism of lysergic acid diethylamide (LSD) to 2-oxo-3-hydroxy LSD (O-H-LSD) in human liver microsomes and cryopreserved human hepatocytes.

    Klette, K L; Anderson, C J; Poch, G K; Nimrod, A C; ElSohly, M A

    2000-10-01

    The metabolism of lysergic acid diethylamide (LSD) to 2-oxo-3-hydroxy lysergic acid diethylamide (O-H-LSD) was investigated in liver microsomes and cyropreserved hepatocytes from humans. Previous studies have demonstrated that O-H-LSD is present in human urine at concentrations 16-43 times greater than LSD, the parent compound. Additionally, these studies have determined that O-H-LSD is not generated during the specimen extraction and analytical processes or due to parent compound degradation in aqueous urine samples. However, these studies have not been conclusive in demonstrating that O-H-LSD is uniquely produced during in vivo metabolism. Phase I drug metabolism was investigated by incubating human liver microsomes and cryopreserved human hepatocytes with LSD. The reaction was quenched at various time points, and the aliquots were extracted using liquid partitioning and analyzed by liquid chromatography-mass spectrometry. O-H-LSD was positively identified in all human liver microsomal and human hepatocyte fractions incubated with LSD. In addition, O-H-LSD was not detected in any microsomal or hepatocyte fraction not treated with LSD nor in LSD specimens devoid of microsomes or hepatocytes. This study provides definitive evidence that O-H-LSD is produced as a metabolic product following incubation of human liver microsomes and hepatocytes with LSD.

  4. Identification of a tryptanthrin metabolite in rat liver microsomes by liquid chromatography/electrospray ionization-tandem mass spectrometry.

    Lee, Sang Kyu; Kim, Ghee Hwan; Kim, Dong Hyeon; Kim, Dong Hyun; Jahng, Yurngdong; Jeong, Tae Cheon

    2007-10-01

    Tryptanthrin originally isolated from Isatis tinctoria L. has been characterized to have anti-inflammatory activities through the dual inhibition of cyclooxygenase-2 and 5-lipoxygenase mediated prostaglandin and leukotriene syntheses. To characterize phase I metabolite(s), tryptanthrin was incubated with rat liver microsomes in the presence of NADPH-generating system. One metabolite was identified by liquid chromatography/electrospray ionization-tandem mass spectrometry. M1 could be identified as a metabolite mono-hydroxylated on the aromatic ring of indole moiety from the MS(2) spectra of protonated tryptanthrin and M1. The structure of metabolite was confirmed as 8-hydroxytryptanthrin with a chemically synthesized authentic standard. The formation of M1 was NADPH-dependent and was inhibited by SKF-525A, a general CYP-inhibitor, indicating the cytochrome P450 (CYP)-mediated reaction. In addition, it was proposed that M1 might be formed by CYP 1A in rat liver microsomes from the experiments with enriched rat liver microsomes.

  5. Hepatitis C virus infection associated with liver-kidney microsomal antibody type 1 (LKM1) autoantibodies in children.

    Bortolotti, Flavia; Muratori, Luigi; Jara, Paloma; Hierro, Loreto; Verucchi, Gabriella; Giacchino, Raffaella; Barbera, Cristiana; Zancan, Lucia; Guido, Maria; Resti, Massimo; Pedditzi, Sabrina; Bianchi, Francesco; Gatta, Angelo

    2003-02-01

    To evaluate the clinical pattern and evolution of chronic hepatitis C in children with liver/kidney microsomal antibody type 1 autoantibodies (LKM1). A multicenter, retrospective study, including the following groups of children with hepatitis C virus infection: (1). 21 consecutive LKM1-positive patients, (2). 42 age- and sex- matched LKM1-negative patients, and (3). 4 interferon-induced LKM1-positive cases. LKM1 reactivity to human microsomes and recombinant cytochrome P450IID6 (CYP2D6) was assayed by immunoblotting. Clinical and biochemical features overlapped in LKM1-positive and LKM1-negative children, but a fibrosis score >3 (range 0-6) was significantly more frequent (P =.04) in the former. Reactivity to microsomal protein and CYP2D6 was significantly (P =.02) associated with LKM1 titers >or=1:320 and was found in 39% of patients, including severe cases and both children (of 4 treated) who achieved a sustained alanine aminotransferase (ALT) normalization after steroid treatment. Five of 7 LKM1-positive children treated with interferon had an ALT exacerbation. LKM1-positive hepatitis C in children is characterized by a wide spectrum of biochemical, serologic, and histologic features. Whether autoimmunity may contribute to liver damage in a subgroup of patients with more severe liver disease, high LKM1 titers, and reactivity to CYP2D6 is a question deserving further investigation.

  6. Paradigm Shift in the Management Strategy for Epithelial Ovarian Cancer.

    Fujiwara, Keiichi; McAlpine, Jessica N; Lheureux, Stephanie; Matsumura, Noriomi; Oza, Amit M

    2016-01-01

    The hypothesis on the pathogenesis of epithelial ovarian cancer continues to evolve. Although epithelial ovarian cancer had been assumed to arise from the coelomic epithelium of the ovarian surface, it is now becoming clearer that the majority of serous carcinomas arise from epithelium of the distal fallopian tube, whereas clear cell and endometrioid cancers arise from endometriosis. Molecular and genomic characteristics of epithelial ovarian cancer have been extensively investigated. Our understanding of pathogenesis of the various histologic types of ovarian cancer have begun to inform changes to the strategies for management of epithelial ovarian cancer, which represent a paradigm shift not only for treatment but also for prevention, which previously had not been considered achievable. In this article, we will discuss novel attempts at the prevention of high-grade serous ovarian cancer and treatment strategies for two distinct entities in epithelial ovarian cancer: low-grade serous and clear cell ovarian carcinomas, which are relatively rare and resistant to conventional chemotherapy.

  7. Distinct ontogenic patterns of overt and latent DGAT activities of rat liver microsomes.

    Waterman, Ian J; Price, Nigel T; Zammit, Victor A

    2002-09-01

    We have studied the ontogeny of the two functional diacylglycerol acyltransferase (DGAT) activities (overt and latent) during postnatal development in rat liver. We find that the ontogenic patterns of the two are highly distinct. Overt DGAT shows a transient rise in activity up to day 4 postnatally, after which it declines until weaning; thereafter, it increases steadily to reach high adult values that may contribute to the high rates of turnover of cytosolic triacylglycerol (TAG). By contrast, latent DGAT activity increases continuously during the suckling period but falls sharply upon weaning onto chow but not onto a high-fat diet. Rates of TAG secretion by hepatocytes are higher than in the adult during the first 7 days after birth, and are largely dependent on the mobilization of the abundant intrahepatocyte TAG as a source of acyl moieties. When the hepatic steatosis is cleared (after day 7) the TAG secretion rate declines by 80% to reach adult values. Quantification of the content of mRNA for the DGAT1 and DGAT2 genes does not show correlation with either of the DGAT activities. We conclude that post-translational modification may play an important role in the overt and latent distribution of DGAT activity in the liver microsomal membrane.

  8. Isolation and structural elucidation of tiamulin metabolites formed in liver microsomes of pigs.

    Lykkeberg, Anne Kruse; Cornett, Claus; Halling-Sørensen, Bent; Hansen, Steen Honoré

    2006-09-18

    Although the antimicrobial tiamulin is extensively metabolized in pigs, the metabolism is not well investigated. In this work the NADPH dependent metabolism of tiamulin in liver microsomes from pigs has been studied. The tiamulin metabolites formed in the incubations were analysed using LC-MS, and three major metabolites were isolated using solid phase extraction and preparative HPLC. The final structure elucidations were performed by tandem mass spectrometry and (1)H and (13)C NMR. The structures of the metabolites were found to be 2beta-hydroxy-tiamulin, 8alpha-hydroxy-tiamulin and N-deethyl-tiamulin. In addition, the LC-MS chromatograms revealed two other minor metabolites. From their chromatography and from MS(2) analysis the structures were estimated to be 2beta-hydroxy-N-deethyl-tiamulin and 8alpha-hydroxy-N-deethyl-tiamulin, but the structures were not confirmed by NMR. In these studies approximately 20% of tiamulin was deethylated, 10% was hydroxylated in the 2beta-position and 7% was hydroxylated in the 8alpha-position. About 40% of tiamulin was metabolized during the incubation conditions used. The protein precipitation in the incubations was performed using perchloric acid, and the preparative purification was performed under alkaline conditions. Therefore, the stability of the metabolites under these conditions was studied. The metabolites were found to be stable in the acid solution, but under alkaline conditions, particularly at room temperature, the stability of especially 8alpha-hydroxy-tiamulin was considerably reduced (40% loss after 1 week).

  9. Microsomal detoxication enzyme responses of the marine snail, Thais haemastoma, to laboratory oil exposure

    Livingstone, D.R.; Stickle, W.B.; Kapper, M.; Wang, S.

    1986-01-01

    The cytochrome P-450 monooxygenase or mixed function oxidase (MFO) system is a widely distributed enzyme system involved in the detoxication of foreign organic compounds (xenobiotics) taken up by organisms. Increases in the activities of the MFO system, occur with exposure of the organism to organic xenobiotics and such responses in the field have been proposed as a means of identifying biological impact by organic pollution. The carnivorous marine gastropod Thais haemastoma, or southern oyster drill, rapidly accumulated polynuclear aromatic and other hydrocarbons from the environment, through both the food source and the water-column. In laboratory experiments T. haemastoma were exposed to the water soluble fraction (WSF) of South Louisiana crude oil and the responses of the MFO system examined. Preliminary characterization of the snail MFO system was carried out using methodology developed from studies on the common mussel Mytilus edulis. Microsomal benz[a]pyrene hydroxylase (BPH), NADH- and NADPH- dependent cytochrome c reductase (NAD(P)H-CYTCRED) and NADH-dependent ferricyanide reductase (NADH-FERRIRED) activities were measured but it was not possible to determine cytochrome P-450 or b 5

  10. Shotgun Proteomics of Aspergillus niger Microsomes upon d-Xylose Induction▿ †

    de Oliveira, José Miguel P. Ferreira; van Passel, Mark W. J.; Schaap, Peter J.; de Graaff, Leo H.

    2010-01-01

    Protein secretion plays an eminent role in cell maintenance and adaptation to the extracellular environment of microorganisms. Although protein secretion is an extremely efficient process in filamentous fungi, the mechanisms underlying protein secretion have remained largely uncharacterized in these organisms. In this study, we analyzed the effects of the d-xylose induction of cellulase and hemicellulase enzyme secretion on the protein composition of secretory organelles in Aspergillus niger. We aimed to systematically identify the components involved in the secretion of these enzymes via mass spectrometry of enriched subcellular microsomal fractions. Under each condition, fractions enriched for secretory organelles were processed for tandem mass spectrometry, resulting in the identification of peptides that originate from 1,081 proteins, 254 of which—many of them hypothetical proteins—were predicted to play direct roles in the secretory pathway. d-Xylose induction led to an increase in specific small GTPases known to be associated with polarized growth, exocytosis, and endocytosis. Moreover, the endoplasmic-reticulum-associated degradation (ERAD) components Cdc48 and all 14 of the 20S proteasomal subunits were recruited to the secretory organelles. In conclusion, induction of extracellular enzymes results in specific changes in the secretory subproteome of A. niger, and the most prominent change found in this study was the recruitment of the 20S proteasomal subunits to the secretory organelles. PMID:20453123

  11. Shotgun proteomics of Aspergillus niger microsomes upon D-xylose induction.

    Ferreira de Oliveira, José Miguel P; van Passel, Mark W J; Schaap, Peter J; de Graaff, Leo H

    2010-07-01

    Protein secretion plays an eminent role in cell maintenance and adaptation to the extracellular environment of microorganisms. Although protein secretion is an extremely efficient process in filamentous fungi, the mechanisms underlying protein secretion have remained largely uncharacterized in these organisms. In this study, we analyzed the effects of the d-xylose induction of cellulase and hemicellulase enzyme secretion on the protein composition of secretory organelles in Aspergillus niger. We aimed to systematically identify the components involved in the secretion of these enzymes via mass spectrometry of enriched subcellular microsomal fractions. Under each condition, fractions enriched for secretory organelles were processed for tandem mass spectrometry, resulting in the identification of peptides that originate from 1,081 proteins, 254 of which-many of them hypothetical proteins-were predicted to play direct roles in the secretory pathway. d-Xylose induction led to an increase in specific small GTPases known to be associated with polarized growth, exocytosis, and endocytosis. Moreover, the endoplasmic-reticulum-associated degradation (ERAD) components Cdc48 and all 14 of the 20S proteasomal subunits were recruited to the secretory organelles. In conclusion, induction of extracellular enzymes results in specific changes in the secretory subproteome of A. niger, and the most prominent change found in this study was the recruitment of the 20S proteasomal subunits to the secretory organelles.

  12. The role of microsomal enzyme inducers in the reduction of misonidazole neurotoxicity

    Jones, D.H.; Bleehen, N.M.; Workman, P.; Smith, N.C.

    1983-01-01

    It has been shown that phenytoin, 300 mg daily for one week, produces consistent hepatic microsomal enzyme induction, resulting in a decrease of 25% in misonidazole half-life, without causing any toxicity per se. A longer period of administration gives only a slightly greater induction. Phenobarbitone in a daily dose of 90 mg causes a reduction of 18% and 23% in misonidazole half-life after 1 and 2 weeks' pre-treatment respectively, but is less suitable clinically because of its sedative effect. A further series of studies using phenytoin as the inducing agent has shown that, despite adequate enzyme induction and increased misonidazole metabolism, it is impossible to increase the total dose of misonidazole beyond the usually accepted value of 12 g/m 2 because of unacceptable neuropathy (a rate of 50% at a dose of 14 g/m 2 over three weeks). In single doses of above 3.0-4.0 g of misonidazole, severe nausea and vomiting are prominent, so that this side effect is a determining factor in the treatment fractionation. Audiometric studies show no correlation between the incidence of peripheral neuropathy and abnormal audiograms, and have no value in the early prediction of neurotoxicity. (author)

  13. Antioxidant Capacity of Flavonoids in Hepatic Microsomes Is not Reflected by Antioxidant Effects In Vivo

    Garry Duthie

    2012-01-01

    Full Text Available Flavonoids are polyphenolic compounds with potential antioxidant activity via multiple reduction capacities. Oxidation of cellular lipids has been implicated in many diseases. Consequently, this study has assessed the ability of several dietary flavonoid aglycones to suppress lipid peroxidation of hepatic microsomes derived from rats deficient in the major lipid soluble antioxidant, dα-tocopherol. Antioxidant effectiveness was galangin > quercetin > kaempferol > fisetin > myricetin > morin > catechin > apigenin. However, none of the flavonoids were as effective as dα-tocopherol, particularly at the lowest concentrations used. In addition, there appears to be an important distinction between the in vitro antioxidant effectiveness of flavonoids and their ability to suppress indices of oxidation in vivo. Compared with dα-tocopherol, repletion of vitamin E deficient rats with quercetin, kaempferol, or myricetin did not significantly affect indices of lipid peroxidation and tissue damage. Direct antioxidant effect of flavonoids in vivo was not apparent probably due to low bioavailability although indirect redox effects through stimulation of the antioxidant response element cannot be excluded.

  14. Role of microsomal enzyme inducers in the reduction of misonidazole neurotoxicity

    Jones, D.H.; Bleehen, N.M.; Workman, P.; Smith, N.C. (Cambridge Univ. (UK). Dept. of Clinical Oncology and Radiotherapeutics; Addenbrooke' s Hospital, Cambridge (UK))

    1983-11-01

    It has been shown that phenytoin, 300 mg daily for one week, produces consistent hepatic microsomal enzyme induction, resulting in a decrease of 25% in misonidazole half-life, without causing any toxicity per se. A longer period of administration gives only a slightly greater induction. Phenobarbitone in a daily dose of 90 mg causes a reduction of 18% and 23% in misonidazole half-life after 1 and 2 weeks' pre-treatment respectively, but is less suitable clinically because of its sedative effect. A further series of studies using phenytoin as the inducing agent has shown that, despite adequate enzyme induction and increased misonidazole metabolism, it is impossible to increase the total dose of misonidazole beyond the usually accepted value of 12 g/m/sup 2/ because of unacceptable neuropathy (a rate of 50% at a dose of 14 g/m/sup 2/ over three weeks). In single doses of above 3.0-4.0 g of misonidazole, severe nausea and vomiting are prominent, so that this side effect is a determining factor in the treatment fractionation. Audiometric studies show no correlation between the incidence of peripheral neuropathy and abnormal audiograms, and have no value in the early prediction of neurotoxicity.

  15. Stereoselective in vitro metabolism of rhynchophylline and isorhynchophylline epimers of Uncaria rhynchophylla in rat liver microsomes.

    Wang, Xin; Qiao, Zhou; Liu, Jia; Zheng, Mei; Liu, Wenyuan; Wu, Chunyong

    2017-11-10

    1. The objective was to investigate the underlying mechanism of the stereoselectivity in the metabolism of rhynchophylline (RIN) and isorhynchophylline (IRN) epimers in rat liver microsomes (RLM). 2. After incubation, eight metabolites of RIN (M1-5) and IRN (M6-8) reacted at A- and C-ring were identified using LC-Q-TOF/MS. Metabolic pathways included oxidation, hydroxylation, N-oxidation and dehydrogenation. In addition, hydroxylation at A-ring was the major metabolic pathway for RIN whereas the oxidation at C-ring was the major one for IRN. 3. Enzyme kinetics showed that the intrinsic clearance (CL int ) for IRN elimination was 1.9-fold higher than RIN and the degradation half-life (T 1/2 ) of RIN was 4.7-fold higher than that of IRN, indicating IRN was more favorable to be metabolized than RIN in RLM. 4. Data from chemical inhibition study demonstrated CYP3A was the predominant isoform involved in the metabolic elimination of both epimers, as well as the formation of M1-8. 5. In conclusion, data revealed that due to the spatial configurations at C-7 position, RIN and IRN epimers possessed different hepatic metabolic pathways and elimination rates which were mainly mediated by CYP3A.

  16. Anti-liver-kidney microsome antibody type 1 recognizes human cytochrome P450 db1.

    Gueguen, M; Yamamoto, A M; Bernard, O; Alvarez, F

    1989-03-15

    Anti-liver-kidney microsome antibody type 1 (LKM1), present in the sera of a group of children with autoimmune hepatitis, was recently shown to recognize a 50 kDa protein identified as rat liver cytochromes P450 db1 and db2. High homology between these two members of the rat P450 IID subfamily and human P450 db1 suggested that anti-LKM1 antibody is directed against this human protein. To test this hypothesis, a human liver cDNA expression library in phage lambda GT-11 was screened using rat P450 db1 cDNA as a probe. Two human cDNA clones were found to be identical to human P450 db1 by restriction mapping. Immunoblot analysis using as antigen, the purified fusion protein from one of the human cDNA clones showed that only anti-LKM1 with anti-50 kDa reactivity recognized the fusion protein. This fusion protein was further used to develop an ELISA test that was shown to be specific for sera of children with this disease. These results: 1) identify the human liver antigen recognized by anti-LKM1 auto-antibodies as cytochrome P450 db1, 2) allow to speculate that mutation on the human P450 db1 gene could alter its expression in the hepatocyte and make it auto-antigenic, 3) provide a simple and specific diagnostic test for this disease.

  17. Detection of liver kidney microsomal type 1 antibody using molecularly based immunoassays.

    Kerkar, N; Ma, Y; Davies, E T; Cheeseman, P; Mieli-Vergani, G; Vergani, D

    2002-12-01

    To assess the diagnostic value of two commercial molecularly based immunoassays detecting liver kidney microsomal type 1 antibody (LKM1). The performance of Varelisa and LKM1 enzyme linked immunosorbent assay (ELISA) was compared with immunofluorescence, and two validated research techniques-an in house ELISA and a radioligand assay measuring antibodies to P4502D6. Thirty serum samples from three patients with autoimmune hepatitis type 2 covering immunofluorescence titres of 1/10 to 1/10 240 and 55 LKM1 negative controls were tested. All 30 sera that were LKM1 positive by immunofluorescence were positive by the in house ELISA, the radioligand assay, and LKM1-ELISA, and 29 were also positive by Varelisa. None of the 55 sera negative for LKM1 by immunofluorescence was positive by the in house ELISA and radioligand assay, but one was positive by Varelisa and 14 were positive using the LKM1-ELISA. Agreement between immunofluorescence, the in house ELISA, the radioligand assay, and Varelisa was high (kappa > 0.8), and agreement between immunofluorescence and LKM1-ELISA was moderate (kappa = 0.63). The assay kit marketed as Varelisa allows accurate detection of LKM1.

  18. Analytical approaches for the detection of epoxides and hydroperoxides in active pharmaceutical ingredients, drug products and herbals.

    Elder, D P; Snodin, D; Teasdale, A

    2010-04-06

    This review summarizes the analytical approaches reported in the literature relating to epoxide and hydroperoxide impurities. It is intended that it should provide guidance for analysts faced by the need to control such impurities, particularly where this is due to concerns relating to their potential genotoxicity. An extensive search of the literature relating to this class of impurities revealed a large number of references relating to analysis of epoxides/hydroperoxides associated with herbal remedies. Given the general applicability of the analytical methodology and due to the widespread use of herbal products the authors decided to include herbal medicines in this review. The review also reflects on the very different approaches taken in terms of the assessment/control of genotoxic impurities for such herbal remedies to that required for pharmaceutical products. Copyright 2009 Elsevier B.V. All rights reserved.

  19. Iron-functionalized nanoporous silica type SBA-15: Synthesis, characterization and application in alkene epoxidation in presence of hydrogen peroxide

    Mahdieh Ghazizadeh

    2017-05-01

    Full Text Available Fe(IIIsalophen complex on a SBA-15 support functionalized with (3-aminopropyltriethoxysilane as a linker. It has been synthesized and characterized by XRD, adsorption–desorption of nitrogen, SEM, FT-IR and UV–Vis. The formation of metal-salophen complex with the amino groups as connectors to the SBA-15 surface was confirmed. This material was successfully used as a heterogeneous catalyst for the epoxidation of alkenes and the effects of reaction time, different solvents and amount of catalyst on catalytic activity were investigated. This catalyst gave suitable and comparable yield and percentage conversion values. It is also stable and can be recycled and reused in the epoxidation of alkenes.

  20. Immersion calorimetry as a tool to evaluate the catalytic performance of titanosilicate materials in the epoxidation of cyclohexene.

    Vernimmen, Jarian; Guidotti, Matteo; Silvestre-Albero, Joaquin; Jardim, Erika O; Mertens, Myrjam; Lebedev, Oleg I; Van Tendeloo, Gustaaf; Psaro, Rinaldo; Rodríguez-Reinoso, Francisco; Meynen, Vera; Cool, Pegie

    2011-04-05

    Different types of titanosilicates are synthesized, structurally characterized, and subsequently catalytically tested in the liquid-phase epoxidation of cyclohexene. The performance of three types of combined zeolitic/mesoporous materials is compared with that of widely studied Ti-grafted-MCM-41 molecular sieve and the TS-1 microporous titanosilicate. The catalytic test results are correlated with the structural characteristics of the different catalysts. Moreover, for the first time, immersion calorimetry with the same substrate molecule as in the catalytic test reaction is applied as an extra means to interpret the catalytic results. A good correlation between catalytic performance and immersion calorimetry results is found. This work points out that the combination of catalytic testing and immersion calorimetry can lead to important insights into the influence of the materials structural characteristics on catalysis. Moreover, the potential of using immersion calorimetry as a screening tool for catalysts in epoxidation reactions is shown.

  1. Ovarian function after uterine artery embolisation

    2009-08-05

    Aug 5, 2009 ... Objective. To evaluate ovarian function in 29 patients who underwent uterine artery embolisation ... of FSH levels, kidney function, blood count and clotting time. .... Funding: Departmental funds and routine services in hospital;.

  2. Biological Basis for Chemoprevention of Ovarian Cancer

    Berchuck, Andrew

    2006-01-01

    To achieve a better understanding of the etiology of ovarian cancer we have initiated a case-control study that considers genetic susceptibility epidemiologic risk factors and acquired genetic alterations...

  3. Ovarian hyperstimulation, hyperprolactinaemia and LH gonadotroph adenoma.

    Castelo-Branco, Camil; del Pino, Marta; Valladares, Esther

    2009-08-01

    This report considers a highly exceptional case of ovarian hyperstimulation syndrome due to a gonadotroph adenoma secreting LH in a 31-year-old patient who presented with amenorrhoea and galactorrhoea syndrome and a complex bilateral ovarian mass. Magnetic resonance imaging revealed a pituitary adenoma, and laboratory tests corroborated the hyperprolactinaemia without other hormonal pituitary abnormalities. Ovarian hyperstimulation syndrome due to a gonadotroph adenoma with normal gonadotrophins is extremely rare. Most of the described cases are caused by FSH adenomas. Due to the originality of the case, it was considered useful for understanding the management of this entity, and it is proposed that LH adenomas should also be considered in the differential diagnosis of patients with spontaneous ovarian hyperstimulation syndrome.

  4. Evaluating the ovarian cancer gonadotropin hypothesis

    Lee, Alice W; Tyrer, Jonathan P; Doherty, Jennifer A

    2015-01-01

    OBJECTIVE: Ovarian cancer is a hormone-related disease with a strong genetic basis. However, none of its high-penetrance susceptibility genes and GWAS-identified variants to date are known to be involved in hormonal pathways. Given the hypothesized etiologic role of gonadotropins, an assessment...... of how variability in genes involved in the gonadotropin signaling pathway impacts disease risk is warranted. METHODS: Genetic data from 41 ovarian cancer study sites were pooled and unconditional logistic regression was used to evaluate whether any of the 2185 SNPs from 11 gonadotropin signaling pathway...... genes was associated with ovarian cancer risk. A burden test using the admixture likelihood (AML) method was also used to evaluate gene-level associations. RESULTS: We did not find any genome-wide significant associations between individual SNPs and ovarian cancer risk. However, there was some...

  5. Molecular Imaging of Ovarian Carcinoma Angiogenesis

    Chen, Xiaoyuan

    2007-01-01

    .... Ovarian cancer is angiogenesis dependent. Integrin , a key player in tumor angiogenesis and metastasis, has been identified as a target for diagnostic and therapeutic interventions for several highly proliferative and metastatic tumor types...

  6. Predictive and therapeutic markers in ovarian cancer

    Gray, Joe W.; Guan, Yinghui; Kuo, Wen-Lin; Fridlyand, Jane; Mills, Gordon B.

    2013-03-26

    Cancer markers may be developed to detect diseases characterized by increased expression of apoptosis-suppressing genes, such as aggressive cancers. Genes in the human chromosomal regions, 8q24, 11q13, 20q11-q13, were found to be amplified indicating in vivo drug resistance in diseases such as ovarian cancer. Diagnosis and assessment of amplification levels certain genes shown to be amplified, including PVT1, can be useful in prediction of poor outcome of patient's response and drug resistance in ovarian cancer patients with low survival rates. Certain genes were found to be high priority therapeutic targets by the identification of recurrent aberrations involving genome sequence, copy number and/or gene expression are associated with reduced survival duration in certain diseases and cancers, specifically ovarian cancer. Therapeutics to inhibit amplification and inhibitors of one of these genes, PVT1, target drug resistance in ovarian cancer patients with low survival rates is described.

  7. Hormone therapy and different ovarian cancers

    Mørch, Lina Steinrud; Løkkegaard, Ellen; Andreasen, Anne Helms

    2012-01-01

    Postmenopausal hormone therapy use increases the risk of ovarian cancer. In the present study, the authors examined the risks of different histologic types of ovarian cancer associated with hormone therapy. Using Danish national registers, the authors identified 909,946 women who were followed from...... 1995-2005. The women were 50-79 years of age and had no prior hormone-sensitive cancers or bilateral oophorectomy. Hormone therapy prescription data were obtained from the National Register of Medicinal Product Statistics. The National Cancer and Pathology Register provided data on ovarian cancers......, including information about tumor histology. The authors performed Poisson regression analyses that included hormone exposures and confounders as time-dependent covariates. In an average of 8.0 years of follow up, 2,681 cases of epithelial ovarian cancer were detected. Compared with never users, women...

  8. Novel Treatment Shrinks Ovarian Tumors in Mice

    Researchers have developed a new approach for treating tumors that express mutant versions of the p53 protein, which are present in more than half of all cancers, including an aggressive and common subtype of ovarian cancer.

  9. IP Chemo for Ovarian Cancer is Underused

    Use of intraperitoneal chemotherapy, along with intravenous chemotherapy, improves survival in some women with advanced ovarian cancer, but its use in clinical practice has been limited, according to a new study.

  10. Evaluation of unilateral versus bilateral ovarian drilling in clomiphene citrate resistant cases of polycystic ovarian syndrome.

    Roy, K K; Baruah, Jinee; Moda, Nidhi; Kumar, Sunesh

    2009-10-01

    Laparoscopic ovarian drilling (LOD) has been put forward as the treatment of choice in women with clomiphene citrate (CC)-resistant polycystic ovary syndrome (PCOS), with tubo-ovarian adhesion formation as the major disadvantage. Our study proposed to compare the efficacy of laparoscopic unilateral ovarian drilling with bilateral ovarian drilling in terms of ovulation and pregnancy rate with the expected advantage of decreasing postoperative adhesion rate and change in fimbiro ovarian relationship with unilateral drilling. This prospective randomized study included 44 patients with anovulatory infertility due to PCOS. Twenty-two patients underwent unilateral ovarian drilling in group-I and 22 patients underwent bilateral ovarian drilling in group-II between June 2005 and June 2007. The number of drilling site in each ovary was limited to five. The clinical and biochemical response, ovulation and pregnancy rates over a follow-up period of 1 year were compared. Tubo-ovarian adhesion rate was compared during cesarean section or during repeat laparoscopy. There was no statistical difference between the two groups in terms of clinical and biochemical response, ovulation rate and pregnancy rate. Postoperatively, tubo-ovarian adhesions could be assessed in 36.3% of the patients and no adhesions were found in a single case in either group. Unilateral drilling cauterization of ovary is equally efficacious as bilateral drilling in inducing ovulation and achieving pregnancy. Unilateral ovarian drilling may be a suitable option in clomiphene citrate resistant infertility patient of PCOS which can replace bilateral ovarian drilling with the potential advantage of decreasing the chances of adhesion formation.

  11. Benzo(a)pyrene diol epoxides as intermediates in nucleic acid binding in vitro and in vivo.

    Weinstein, I B; Jeffrey, A M; Jennette, K W; Blobstein, S H; Harvey, R G; Harris, C; Autrup, H; Kasai, H; Nakanishi, K

    1976-08-13

    Evidence has been obtained that a specific isomer of a diol epoxide derivative of benzo(a)pyrene, (+/-)-7 beta,8alpha-dihydroxy-9alpha, 10alpha-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene, is an intermediate in the binding of benzo(a)pyrene to RNA in cultured bovine bronchial mucosa. An adduct is formed between position 10 of this derivative and the 2-amino group of guanine.

  12. Enantioselective syntheses of aeruginosin 298-A and its analogues using a catalytic asymmetric phase-transfer reaction and epoxidation.

    Ohshima, Takashi; Gnanadesikan, Vijay; Shibuguchi, Tomoyuki; Fukuta, Yuhei; Nemoto, Tetsuhiro; Shibasaki, Masakatsu

    2003-09-17

    We developed a versatile synthetic process for aeruginosin 298-A as well as several attractive analogues, in which all stereocenters were controlled by a catalytic asymmetric phase-transfer reaction and epoxidation. Furthermore, drastic counteranion effects in phase-transfer catalysis were observed for the first time, making it possible to three-dimensionally fine-tune the catalyst (ketal part, aromatic part, and counteranion).

  13. Silica-supported, single-site titanium catalysts for olefin epoxidation. A molecular precursor strategy for control of catalyst structure.

    Jarupatrakorn, Jonggol; Don Tilley, T

    2002-07-17

    A molecular precursor approach involving simple grafting procedures was used to produce site-isolated titanium-supported epoxidation catalysts of high activity and selectivity. The tris(tert-butoxy)siloxy titanium complexes Ti[OSi(O(t)Bu)(3)](4) (TiSi4), ((i)PrO)Ti[OSi(O(t)Bu)(3)](3) (TiSi3), and ((t)BuO)(3)TiOSi(O(t)Bu)(3) (TiSi) react with the hydroxyl groups of amorphous Aerosil, mesoporous MCM-41, and SBA-15 via loss of HO(t)Bu and/or HOSi(O(t)Bu)(3) and introduction of titanium species onto the silica surface. Powder X-ray diffraction, nitrogen adsorption/desorption, infrared, and diffuse reflectance ultraviolet spectroscopies were used to investigate the structures and chemical natures of the surface-bound titanium species. The titanium species exist mainly in isolated, tetrahedral coordination environments. Increasing the number of siloxide ligands in the molecular precursor decreases the amount of titanium that can be introduced this way, but also enhances the catalytic activity and selectivity for the epoxidation of cyclohexene with cumene hydroperoxide as oxidant. In addition, the high surface area mesoporous silicas (MCM-41 and SBA-15) are more effective than amorphous silica as supports for these catalysts. Supporting TiSi3 on the SBA-15 affords highly active cyclohexene epoxidation catalysts (0.25-1.77 wt % Ti loading) that provide turnover frequencies (TOFs) of 500-1500 h(-1) after 1 h (TOFs are reduced by about half after calcination). These results demonstrate that oxygen-rich siloxide complexes of titanium are useful as precursors to supported epoxidation catalysts.

  14. Biological Basis for Chemoprevention of Ovarian Cancer

    2006-10-01

    Concealing Clothing” Sukru Hatun, Omer Islam, Filiz Cizmecioglu, Bulent Kara, Kadir Babaoglu, Fatma Berk,and Ayse Sevim Go¨ kalp J. Nutr. 135: 218–222...to studies in ovarian caner , analyses of the relationship between the short AR CAG repeat length polymorphism and prostate cancer risk also have...pregnant, months of OC use, BMI, tubal ligation, family history of breast or ovarian caner in a first degree relative, waist-to-hip ratio 23 Table 6

  15. Ovarian neoplasms in atomic bomb survivors

    Tokuoka, Shoji

    1986-01-01

    A recent pathological and epidemiological study on females with ovarian neoplasms among the Radiation Effects Research Foundation (RERF) Life Span Study (LSS) Extended Sample ascertained 194 malignant and 106 benign ovarian tumor cases which had occurred during the period 1950 - 80. Of the 194 cases of ovarian cancer, 128 (66 %) were reviewed microscopically and the age-adjusted incidence of ovarian cancer revealed a statistically significant linear increase with increasing exposure dose, both in microscopically reviewed and in all cases. The radiation-related excess of ovarian cancer appeared to be highest in women less than 20 years of age when exposed, with these women having the longest latent period for tumor development, compared to the older age groups. The histological distribution of cancer types among exposed individuals appeared not very different from that seen in the general population. The analysis of 106 autopsy subjects with benign ovarian tumors, of which 89 were reviewed microscopically, depicted a trend of increasing radiation-related tumor excess with increasing exposure dose among exposed cases, though the trend is not statistically significant when observation was limited to microscopically reviewed subjects. The histological distribution of benign tumor types among exposed cases appeared not very different from that seen in the general population. The findings are consistent with a hypothesis that radiation-injured ovaries in association with secondary excess of gonadotrophic hormones are important causative factors in the development of ovarian tumors, which has been suggested by experimental findings concerning the induction of ovarian tumors by ionizing radiation and by a recent analysis of breast carcinogenesis in exposed females of Hiroshima and Nagasaki. (author)

  16. Transient sexual precocity and ovarian cysts.

    Lyon, A J; De Bruyn, R; Grant, D B

    1985-01-01

    Nine girls presenting under the age of 7 years with unsustained sexual precocity are described. Large ovarian cysts were detected by ultrasound in three and laparotomy in one. In two girls the symptoms resolved after surgical removal of the cyst; the other seven had spontaneous remission of symptoms, but in two of these transient breast development and bleeding recurred: further ovarian cyst formation was found in one of these patients. Endocrine studies performed before resolution of the cys...

  17. Vanishing large ovarian cyst with thyroxine therapy

    Dharmshaktu, Pramila; Kutiyal, Aditya; Dhanwal, Dinesh

    2013-01-01

    Summary A 21-year-old female patient recently diagnosed with severe hypothyroidism was found to have a large ovarian cyst. In view of the large ovarian cyst, she was advised to undergo elective laparotomy in the gynaecology department. She was further evaluated in our medical out-patient department (OPD), and elective surgery was withheld. She was started on thyroxine replacement therapy, and within a period of 4 months, the size of the cyst regressed significantly, thereby improving the cond...

  18. [The molecular biology of epithelial ovarian cancer].

    Leary, Alexandra; Pautier, Patricia; Tazi, Youssef; Morice, Philippe; Duvillard, Pierre; Gouy, Sébastien; Uzan, Catherine; Gauthier, Hélène; Balleyguier, Corinne; Lhommé, Catherine

    2012-12-01

    Epithelial ovarian cancer frequently presents at an advanced stage where the cornerstone of management remains surgery and platinum-based chemotherapy. Unfortunately, despite sometimes dramatic initial responses, advanced ovarian cancer almost invariably relapses. Little progress has been made in the identification of effective targeted-therapies for ovarian cancer. The majority of clinical trials investigating novel agents have been negative and the only approved targeted-therapy is bevacizumab, for which reliable predictive biomarkers still elude us. Ovarian cancer is treated as a uniform disease. Yet, biological studies have highlighted the heterogeneity of this malignancy with marked differences in histology, oncogenesis, prognosis, chemo-responsiveness, and molecular profile. Recent high throughput molecular analyses have identified a huge number of genomic/phenotypic alterations. Broadly speaking, high grade serous carcinomas (type II) display significant genomic instability and numerous amplifications and losses; low grade (type I) tumors are genomically stable but display frequent mutations. Importantly, many of these genomic alterations relate to known oncogenes for which targeted-therapies are available or in development. There is today a real potential for personalized medicine in ovarian cancer. We will review the current literature regarding the molecular characterization of epithelial ovarian cancer and discuss the biological rationale for a number of targeted strategies. In order to translate these biological advances into meaningful clinical improvements for our patients, it is imperative to incorporate translational research in ovarian cancer trials, a number of strategies will be proposed such as the acquisition of quality tumor samples, including sequential pre- and post-treatment biopsies, the potential of liquid biopsies, and novel trial designs more adapted to the molecular era of ovarian cancer research.

  19. Seasonal variation in tissue estrogen-2/4-hydroxylases (EH) and in vitro effects of steroids on ovarian EH activity in the catfish Heteropneustes fossilis.

    Chourasia, T K; Joy, K P

    2010-12-12

    A radiometric assay was used to measure microsomal EH activity from tritiated H(2)O formed during the conversion of [2,4 (3)H] estradiol-17β into catecholestrogens in the microsomal fractions of liver, brain and ovary of the catfish Heteropneustes fossilis. The validation data show that enzyme activity increased with incubation time, and substrate and cofactor (NADPH) concentrations, elicited temperature optima of 30-37°C and pH optima of 6.8-7.8. EH activity was strongly NADPH-dependent and in its absence only 13.48% activity was recorded. Liver recorded the highest enzyme activity, followed by brain and ovary. EH activity showed a significant seasonal variation with the peak activity in spawning phase and the lowest activity in resting phase. In the ovary, the follicular layer (theca and granulosa) elicited the highest activity over that of the denuded oocytes. Modulatory effects of steroids on ovarian enzyme activity were further demonstrated. The incubation of postvitellogenic follicles with 1, 10 or 100 nM concentrations of various steroids for 24 h produced varied effects on EH activity. Progesterone and 2-hydroxyestradiol-17β elicited strong suppressive effects on enzyme activity. Estrogens (E(1), E(2) and E(3)) suppressed the activity in a concentration-dependent manner. Among the progestins tested, 17,20α-dihydroxy-4-pregnen-3-one, the isomer of 17,20β-dihydroxy-4-pregnen-3-one (a teleost maturation-inducing steroid) showed the lowest depressing effect. Among androgens, the testosterone metabolite 11-ketotestosterone (functional teleost androgen) showed a high suppressing effect. Corticosteroids elicited low activity with cortisol suppressed the activity at higher concentrations. The study will form a basis to understand the physiological role of catecholestrogens in ovarian functions. Copyright © 2010 Elsevier Inc. All rights reserved.

  20. Metal–organic framework-based catalysts: Chemical fixation of CO2 with epoxides leading to cyclic organic carbonates

    M. Hassan eBeyzavi

    2015-01-01

    Full Text Available As a C1 feedstock, CO2 has the potential to be uniquely highly economical in both a chemical and a financial sense. In particular, the highly atom-economical acid-catalyzed cycloaddition of CO2 to epoxides to yield cyclic organic carbonates (OCs, a functionality having many important industrial applications, is an attractive reaction for the utilization of CO2 as a chemical feedstock. Metal–organic frameworks (MOFs are promising candidates in catalysis as they are a class of crystalline, porous and functional materials with remarkable properties including great surface area, high stability, open channels and permanent porosity. MOFs structure tunability and their affinity for CO2, makes them great catalysts for the formation of OCs using CO2 and epoxides. In this review, we examine MOF-based catalytic materials for the cycloaddition of carbon dioxide to epoxides. Catalysts are grouped based on the location of catalytic sites, i.e., at the struts, nodes, defect sites, or some combination thereof. Additionally, important features of each catalyst system are critically discussed.