Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: DrugBank:APRD00691 (EE2)
 7,802 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

HCV infections are diagnosed by determining the circulating antibodies to the C 100 recombinant viral antigen using the ELISA method. Cut-off analysis from normal subjects and well documented NANBH patients suggests that screening of a low risk group such as blood donors might yield a relatively high ratio of false positives. An immunoblot assay (Chiron RIBA) using 3 recombinant antigens, C 100, 5-1-1 and SOD has been developed for evaluating the ELISA reactives as an additional, more specific assay. In the RIBA testing 51.5% were reactive and 28.5% were indeterminate in ELISA positive donor specimens, and 79.5% were reactive and 8.0% were indeterminate in ELISA positive non-A, non-B hepatitis patients specimens. These findings coincide with the ratio of theoretically calculated true positive. In a study done by Ortho U.S.A. viral RNA were detected in 70% of RIBA reactive, 33% of indeterminate and 3.6% non-reactive specimens by polymerase chain reaction (PCR). Furthermore, an advanced system using another immunogenic region of viral polyprotein including c33c encoded in NS3 has been on trial to evaluate the possibility of confirming HCV infection and detecting seroconversion at an earlier stage.
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PMID:[Interpretation of Ortho HCV Ab ELISA test results by chiron HCV recombinant immunoblot assay]. 184 12

Chromatography's functional versatility, separation efficiency, gentle non-denaturing separating process and ease of automation and scale-up make it attractive for industrial scale protein purification. The Winnipeg Rh Institute's new Plasma Fractionation facility is an example of the use of chromatography for the large scale purification of plasma protein fractions. The fractionation facility has a capacity to process 800 litres of plasma per batch into blood clotting factor VIII and IX, albumin and intravenous immune serum globulin (i.v. ISG). Albumin and i.v. ISG are purified using ion exchange columns of DEAE-Sepharose (230 litre size), DEAE-Biogel (150 litre size) and CM-Sepharose (150 litre size). The chromatographic process is automated using a Modicon 584 Programmable Logic Controller to regulate valves, pumps and sensors which control plasma flow during fractionation. The stainless steel tanks and piping are automatically cleaned-in-place. The high degree of automation and cleaning provides efficient operation and sanitary processing. Chromatographic methods (DEAE-Sepharose and metal chelation) are also being used at the pilot scale to purify the human blood products superoxide dismutase and hemoglobin from outdated red blood cells. Characterization of the protein fractions produced by chromatography has shown them to be of equal or higher quality than fractions produced by other techniques.
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PMID:Chromatographic methods of fractionation. 360 84

Estrogen is a known risk factor for human breast cancer, although the mechanism by which estrogens induce cancer remains unestablished. We have demonstrated that DNA strand breakage is induced synergistically when pBR322 plasmid DNA is incubated in the presence of both a nitric oxide (NO)-releasing compound (diethylamine NONOate, etc.) and a catechol-estrogen (2- or 4-hydroxyestradiol or -hydroxyestrone). Either the NO-releasing compound or the catechol-estrogen alone induced much fewer strand breaks. Estradiol, estrone, O-methylated catechol-estrogens, and diethylstilbestrol did not exert such DNA damaging effects. Strand breakage induced by NO plus 2- or 4-hydroxyestradiol was inhibited by carboxy-PTIO (an NO-trapping agent) and, to a lesser extent, by superoxide dismutase. Antioxidants (e.g., N-acetylcysteine, ascorbate), but not HO. scavengers, exhibited inhibitory effects. A possible mechanism for this strand breakage would be: (1) NO mediates conversion of catechol-estrogens to quinones, (2) the quinone/hydroquinone redox system produces O2.-, and (3) O2.- reacts with NO to form peroxynitrite, which causes DNA strand breaks. Our results imply that interaction of catechol-estrogens and NO, both known to be formed in human breast and uterus, leads to production of a potent oxidant(s), which could cause damage in cells and DNA, thus playing an important role in hormonal carcinogenesis.
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PMID:Synergistic induction of DNA strand breakage by catechol-estrogen and nitric oxide: implications for hormonal carcinogenesis. 943 10

Catecholestrogens are postulated to contribute to carcinogenesis by causing DNA damage mediated by reactive oxygen species generated during redox cycling between catechol and quinone estrogens, and by quinone estrogens that can form depurinating adducts. The above hypothesis is based principally on studies of the cancers that develop in renal cortex of hamsters treated with primary estrogens: Hamster kidney can catalyze 2- and 4-hydroxylation of estrogens and support their redox cycling, and the kidneys of estradiol-treated hamsters show evidence of oxidative cellular and DNA damage. Here we used immunocytochemisty to test the postulate that catechol-O-methyltransferase (COMT), the enzyme that can prevent oxidation of catecholestrogens to their quinone derivatives, would be induced in renal cortex of hamsters treated with estradiol or ethinyl estradiol. In kidneys of control hamsters, COMT was localized in cytoplasm of epithelial cells of proximal convoluted tubules, predominantly in the juxtamedullary region where the estrogen-induced cancers arise. After 2- or 4-weeks of treatment with either estrogen, COMT was seen in epithelial cells of proximal convoluted tubules throughout the cortex, and many cells also showed intense nuclear COMT immunoreactivity. Estradiol-induced renal cancers were negative for COMT, but were surrounded by tubules with intense cytoplasmic and nuclear immunostaining. The nucleus-associated COMT was shown by immunoblot analysis to be the soluble form of the enzyme. Using reverse transcription-polymerase chain reaction amplification, hamster kidney COMT was shown to lack the putative nuclear localization signal sequence present in human COMT. A second phase II enzyme, CuZn-superoxide dismutase (CuZnSOD), was shown by immunocytochemistry to remain extranuclear in proximal convoluted tubules of estrogen-treated hamsters, which indicates entry of COMT into the nucleus to be selective. The findings are consistent with the catechol/quinone estrogen hypothesis of estrogen-induced cancer, while the translocation of the enzyme to the nucleus following estrogen treatment suggests a response to a threat to the genome by electrophilic products of catechols.
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PMID:Induction of nuclear catechol-O-methyltransferase by estrogens in hamster kidney: implications for estrogen-induced renal cancer. 968 93

In this study, we examined the effect of 17 beta-estradiol and selected antiestrogens on uterine NADPH-oxidase activity, superoxide dismutase (SOD) activity, hydride (H.-), dienyl radical and O2 -radical generation, and membrane fluidity. NADPH oxidase activity was positively modulated in estradiol-treated animals and negatively regulated in animals that received injections of AF-45, RU-39411, tamoxifen, or ICI-182780. The SOD activity was markedly reduced in estradiol-treated animals when compared with the control animals. A positive modulation of SOD activity was observed upon treatment with AF45, RU39411, tamoxifen, and ICI 182780, though the potency varied among the individual test compounds. We observed detectable H(.-)-radical generation as evidenced from MNP H.- adduct formation in the uterine cell preparations from untreated control animals. Estradiol produced a tremendous augmentation in the superoxide radical profiles in uterine cell preparations compared to the control levels. All the other compounds that were tested significantly lowered the superoxide levels in the test set-up. AF-45, RU-39411, tamoxifen, and ICI-182780 induced varying orders of suppression of H(.-)-radical generation in the test subjects. There was a significant enhancement in membrane fluidity, hydride radical levels, and dienyl radical generation in the estradiol-treated group. All the antiestrogens did not exhibit a similar action on these parameters. RU-39411 exhibited antiestrogen-like activity in modulating hydride levels and membrane fluidity, whereas it stimulated dienyl radical generation. Thus our tests showed that the selected antiestrogens failed to show estrogen-like activity in these assays. It appears that estradiol exerts feedback control over pro- and antioxidant pathways and that markers of oxidative status could be used as a measure to evaluate the antiestrogenic activity of estradiol agonists/antagonists.
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PMID:Effect of estradiol and selected antiestrogens on pro- and antioxidant pathways in mammalian uterus. 1059 59

Prespawning, adult male and female carp, Cyprinus carpio, were intraperitoneally injected with a single dose of 500 microg/kg of 17alpha-ethynylestradiol (EE2). Blood samples were taken and vitellogenin levels were recorded previous to the injection and 8 days afterward. Western blot analysis of plasma VTG showed a marked response in both males (90-fold) and females (67-fold) after EE2 injection. Also, a significant inhibition of the cytochrome P450 monooxygenase system, namely, 7-ethoxyresorufin O-deethylase (EROD) activity, as well as immunodetected CYP1A protein was observed in the EE2-injected fish. Other cytochrome P450 isozymes, such as CYP3A or NADH cyt (b5) reductase, did not indicate any particular trend; whereas NADPH cyt (P450) reductase was significantly induced in EE2-injected animals. Total cytochrome P450, glutathion S-transferase (GST), and total glutathion peroxidase (GPX) fluctuated in a similar manner, but differences among treated and nontreated animals were not statistically significant. UDP glucuronyl transferase (UDPGT), similar to the antioxidant enzymes catalase, superoxide dismutase (SOD), and Se-GPX, progressively decreased in carrier and injected animals in comparison to the controls, although this trend did not reach statistical significance either.
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PMID:Vitellogenin induction and other biochemical responses in carp, Cyprinus carpio, after experimental injection with 17 alpha-ethynylestradiol. 1078 1

Free radical reactions are involved in processes connected with aging. Estradiol acts as antioxidant and free radical scavenger, but the mechanism of this action remains unknown. Estradiol has a hydroxyphenolic structure and may donate hydrogen atoms to lipid peroxyradicals to terminate chain reactions. There are a few reports concerning the influence of estradiol on natural antioxidant enzyme activity, such as superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT). The aim of this study was to estimate the relationship between the levels of estradiol and lipid peroxide (LPO), a marker of membrane lipid peroxidation, and the correlation between estradiol and erythrocyte SOD and GSH-Px activity. The study included 13 premenopausal and 13 postmenopausal healthy women. Serum levels of estradiol, follicle-stimulating hormone (FSH) and LPO, and erythrocyte SOD and GSH-Px activity were estimated in all subjects. Premenopausal women revealed significantly higher estradiol levels and lower LPO concentrations, as well as significantly higher GSH-Px activity than the postmenopausal group. SOD activity did not differ between the two groups. There was a negative correlation between serum estradiol and LPO levels as well as a positive correlation between estradiol and GSH-Px activity. These results support the hypothesis that estradiol exerts its antioxidant action not only through its chemical structure but probably also through its influence on natural cellular antioxidant enzyme activity.
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PMID:Serum lipid peroxide levels and erythrocyte glutathione peroxidase and superoxide dismutase activity in premenopausal and postmenopausal women. 1156 Jan 4

This study was designed to investigate the effects of melatonin and estradiol (E2) on lipid peroxidation and antioxidant defense enzymes in blood and liver tissue when administered in vivo. Wistar albino rats were divided into three experimental groups and treated with either estradiol (25 mg/kg bw, s.c.), melatonin (i. p.), or melatonin plus E2, whereas control animals had diluent injections only. Melatonin was given 10 mg/kg bw x 2 intraperitoneally 30 min before and 60 min after E2 treatment to the melatonin plus E2 group. Animals were sacrificed three hours after the estradiol injection, and their blood and liver tissues were prepared for biochemical analyses. Tissue malondialdehyde (MDA) levels and antioxidant enzyme activities--superoxide dismutase (SOD) and glutathione peroxidase (GPx)--were determined in the postmitochondrial fraction, and the results were compared. Estradiol injection caused significant increases in both MDA levels and GPx activity in liver. When melatonin was administered in combination with E2, the effect of estradiol on MDA levels was abolished. A significant decrement in SOD activity occurred in melatonin-treated animals. GPx activity in the blood of E2 plus melatonin-injected animals was significantly higher than those in control animals. Melatonin-treated animals exhibited relatively lower levels of SOD activity than those from the control and E2 plus melatonin groups. This indicates that estradiol could exert oxidant action resulting in an increment in tissue malondialdehyde levels. Enhanced activity of GPx in both liver and blood following melatonin injection may indicate the contribution of this neurohormone on the antioxidant defense.
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PMID:Coadministration of melatonin and estradiol in rats: effects on oxidant status. 1160 81

The present study was undertaken to investigate the role of estrogen and progesterone in the expression of copper-zinc superoxide dismutase (Cu,Zn-SOD) and manganese SOD (Mn-SOD) in human endometrial stromal cells (ESC). ESC were incubated with estradiol (10(-8) mol/l), medroxyprogesterone acetate (MPA, 10(-6) mol/l), or estradiol + MPA for 18 days. MPA significantly increased Cu,Zn-SOD and Mn-SOD mRNA levels and enzyme activities as well as the mRNA level of insulin-like growth factor-binding protein-1 (IGFBP-1), a marker for decidualization. Estradiol only augmented the effects of MPA on Cu,Zn-SOD activity and IGFBP-1 mRNA level, and estradiol alone had no effect. To study the withdrawal of estrogen and progesterone (EP withdrawal), ESC that had been treated with estradiol + MPA for 12 days were washed and then incubated with or without estradiol + MPA for a further 11 days. Cu,Zn-SOD mRNA levels and activities declined after EP withdrawal, while they were gradually increased by the continuous treatment with estradiol + MPA. In contrast, Mn-SOD mRNA levels and activities were not affected by EP withdrawal. IGFBP-1 mRNA levels were significantly increased 4 days after EP withdrawal and decreased thereafter, whereas they were gradually increased by the continuous treatment with estradiol + MPA. In conclusion, Cu,Zn-SOD, Mn-SOD and IGFBP-1 are differently regulated by estrogen and progesterone in human ESC. The decrease in Cu,Zn-SOD after the ovarian steroid withdrawal may be involved in endometrial breakdown.
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PMID:Differential regulation of copper-zinc superoxide dismutase and manganese superoxide dismutase by progesterone withdrawal in human endometrial stromal cells. 1175 71

Number of studies indicate that the female gonadal hormone estrogen protects women against several neurodegenerative diseases and cerebral ischemia via various mechanisms. The possible protective effects of estrogen are mediated mainly by three ways; the activation of steroid receptors and/or modulation of a neurotransmitter and/or direct antioxidative action. Therefore we aimed to investigate the effects of estradiol and raloxifene on levels of nitric oxide (NO) and antioxidant enzymes in brain cortex of ovariectomized female rats. Ten Sprague-Dawley rats were used as naive controls while 32 rats were ovariectomized at 120-140 days of age. Twelve weeks after ovariectomy: (1). Ovariectomized Placebo group (n=11), was given physiologic saline. (2). Estrogen group (n=10) was given Ethynyl estradiol, 0.1 mg/kg sc. (3). Raloxifene group (n=10) was given raloxifene, 1 mg/kg sc. At the end of the treatment period (8 weeks), rats were decapitated and cortex samples were dissected. Results showed that ovariectomy caused a decrease in total nitrite-nitrate levels. The NO levels of both the estrogen and the raloxifene group were higher than the placebo group. Catalase activities did not show any significant difference between the groups, while superoxide dismutase (SOD) activities were elevated via ovariectomy. Estradiol and Raloxifene treatment had no statistically significant effect on SOD activity.
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PMID:The effects of estrogen and raloxifene treatment on the antioxidant enzymes and nitrite-nitrate levels in brain cortex of ovariectomized rats. 1258 35


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