47 research outputs found

    A study of the oxidation-induced conformational and functional changes in neuroserpin

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    Background: Neuroserpin, a member of the Serine Proteinase Inhibitor (Serpin) superfamily, is known to be a neuroprotective factor in the focal ischemic stroke followed by reducing the microglial activation. Neuroserpin is a protein rich of methionine residues that can scavenge the free radical species which may increase its neuroprotective effect. On the other hand, the oxidative modifications of the amino acid residues in neuroserpin may lead to changes in its conformation and function. In this study, it was investigated the changes in the conformation and the function of the oxidized neuroserpin. Methods: Neuroserpin expressed in E. coli, BL21 or M15 harboring plasmid pQE81L containing neuroserpin cDNA. Expressed neuroserpin was purified by resin sulfopropyl A50 precharged with 0.1 M NiSO4 under denaturing condition. Neuroserpin was oxidized under oxidative stress condition in the presence of different concentration of hydrogen peroxide. The oxidation of neuroserpin was conveniently detected by a carbonyl content assay using 2, 4 dinitrophenylhydrazine. Changes in tertiary structure of neuroserpin were monitored by spectrofluorimeter to study the alteration of intrinsic fluorescence and also fluorescence of 8-anilinonaphthalin-1 sulfonic acid (ANS) in native and oxidized form of neuroserpin. Results: Total expressed neuroserpin was estimated 4-5 mg/lit in 2XYT culture media. SDS-PAGE analysis of purified neuroserpin showed a single band which reflects the efficiency of the resin SP A50 for purification of the proteins containing 6xHis tag. Carbonyl content of oxidized and native neuroserpin was estimated 12.3 ± 0.3 and 0.45 ± 0.05, respectively. The inhibitory activity of oxidized neuroserpin decreased up to 40-60 as compared with native form of neuroserpin. Intrinsic fluorescence and also the emission of ANS bind to the hydrophobic region of the protein altered from 380 to 85 and in the case of ANS from 105 to 150 in oxidized and native form of neuroserpin, respectively. Conclusion: The decreased intrinsic fluorescence intensity, an enhancement in the fluorescence of ANS, and loss of the inhibitory activity up to 40-60 in neuroserpin, all suggested a conformational modification in the protein under the oxidative stress condition. Remaining the inhibitory activity of neuroserpin reflects that the protein tolerates the oxidative stress condition effectively

    Recombinant Lysyl Oxidase Propeptide Protein Inhibits Growth and Promotes Apoptosis of Pre-Existing Murine Breast Cancer Xenografts

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    Lysyl oxidase propeptide (LOX-PP) ectopic overexpression inhibits the growth of cancer xenografts. Here the ability and mode of action of purified recombinant LOX-PP (rLOX-PP) protein to inhibit the growth of pre-existing xenografts was determined. Experimental approaches employed were direct intratumoral injection (i.t.) of rLOX-PP protein into murine breast cancer NF639 xenografts, and application of a slow release formulation of rLOX-PP implanted adjacent to tumors in NCR nu/nu mice (n = 10). Tumors were monitored for growth, and after sacrifice were subjected to immunohistochemical and Western blot analyses for several markers of proliferation, apoptosis, and for rLOX-PP itself. Direct i.t. injection of rLOX-PP significantly reduced tumor volume on days 20, 22 and 25 and tumor weight at harvest on day 25 by 30% compared to control. Implantation of beads preloaded with 35 micrograms rLOX-PP (n = 10) in vivo reduced tumor volume and weight at sacrifice when compared to empty beads (p<0.05). A 30% reduction of tumor volume on days 22 and 25 (p<0.05) and final tumor weight on day 25 (p<0.05) were observed with a reduced tumor growth rate of 60% after implantation. rLOX-PP significantly reduced the expression of proliferation markers and Erk1/2 MAP kinase activation, while prominent increases in apoptosis markers were observed. rLOX-PP was detected by immunohistochemistry in harvested rLOX-PP tumors, but not in controls. Data provide pre-clinical findings that support proof of principle for the therapeutic anti-cancer potential of rLOX-PP protein formulations

    ICAR: endoscopic skull‐base surgery

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    EFFECT OF HIGH TEMPERATURE OXIDATION ON THE CORROSION BEHAVIOR OF ALUMINIZED LOW CARBON STEEL IN MOLTEN ALUMINUM

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    Hot dip aluminizing was carried out on the low carbon steel rod under optimized conditions. The aluminized samples were further oxidized at 1000̊C in air atmosphere at two different times of 20 and 60 minutes. Microstructure study and phase analysis were studied by scanning electron microscopy and X-ray diffraction methods, respectively. The characterization of the coating showed that, Fe2 Al5 has been the major phase formed on the surface of specimen before heat treatment. Following the oxidation of the coating at high temperature, Al 2O3 was formed on the surface of coating while Fe 2 Al5 transformed into FeAl and Fe 3 Al which are favorable to the hot corrosion resistance of the coating. Corrosion resistance of aluminized samples before and after heat treatment was evaluated by rotating the samples in the molten aluminum at 700 ̊C for various times and the dissolution rate was determined. The obtained results showed that by oxidizing the coating at high temperature, the corrosion resistance of the samples in molten aluminum improves significantly

    Six-month follow-up of Iranian women in methadone treatment: drug use, social functioning, crime, and HIV and HCV seroincidence

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    Kate Dolan1, Shabnam Salimi2, Bijan Nassirimanesh3, Setareh Mohsenifar2, David Allsop1, Azarakhsh Mokri21Program of International Research and Training, National Drug and Alcohol Research Centre, University of New South Wales, Sydney, Australia; 2Iranian National Center for Addiction Studies, Tehran University of Medical Sciences, Tehran, Iran; 3Persepolis Centre, Tehran, IranBackground: In general, information about women who use drugs comes from studies performed in the West. Whether women in countries such as Iran are likely to enter drug treatment or how they will respond is not known.Purpose: To examine the short-term impact of methadone maintenance treatment (MMT) on drug use, dependence, social functioning, crime, and human immunodeficiency virus (HIV) and hepatitis C virus (HCV) risk behavior and seroincidence in female drug users in Iran.Methods: Women were eligible for inclusion in the study if they were assessed as dependent on opiates according to the International Statistical Classification of Diseases and Related Health Problems, tenth revision (ICD-10). The sample comprised 78 female heroin or opium users who attended the Persepolis women&amp;#39;s drug treatment clinic in Tehran between 2007 and 2008. Participants were followed up in 2009/2010. Heroin and the use of other drugs, social functioning, involvement in crime, and involvement in HIV and HCV risk behavior were measured by self-report. The prevalence and incidence of HIV and HCV were measured by serology and self-report.Findings: Of the 78 women recruited, 40 were followed up, and this occurred approximately 7 months later. One in four women reported a history of drug injection. At follow-up there were significant reductions in self-reported heroin use on ICD-10 dependence scores. Subjects with more severe drug dependence at baseline were significantly more likely to be criminally active than less severely dependent subjects. Baseline prevalence for HIV and HCV was 5% and 24%, respectively. At follow-up, no one had acquired HIV infection, but one participant had acquired HCV, giving an incidence rate of 7.1 per 100 person-years.Conclusion: This research provides the first evidence that Iranian female drug users can enter MMT and respond well. Within a few months of entering MMT, improvements occurred in heroin use, levels of dependence, social functioning, and HIV risk behavior. While the incidence of blood-borne viral infections was low, there was a serious risk of HIV transmission among this cohort and also to participants&amp;#39; needle and sexual contacts. In a country with high levels of drug use, the high levels of HCV among female drug users require more women to enter drug treatment if an HIV epidemic is to be avoided. Many participants had a chronic drug problem and had had little or no previous exposure to MMT. The introduction or expansion of women-only drug treatment services is urgently needed in order to engage more women in treatment.Keywords: women drug users, Iran, drug treatment clinic, risk behavio
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