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Sample records for chloramines

  1. Inactivation of Helicobacter pylori by Chloramination

    Science.gov (United States)

    Three strains of Helicobacter pylori (H. pylori) were studied to determine their resistance to chloramination. H. pylori is an organism listed on the U.S. Environmental Protection Agency’s (USEPA) Contaminant Control List (CCL). H. pylori was exposed to 2ppm of pre-formed monoc...

  2. Chloramine-induced anaphylaxis while showering: a case report

    Directory of Open Access Journals (Sweden)

    D’Alò Simona

    2012-09-01

    Full Text Available Abstract Introduction Sodium-N-chlorine-p-toluene sulfonamide, commonly known as chloramine-T, is a derivative of chlorine which is widely used as a disinfectant. For many years, chloramine-T has been described as a cause of immediate-type hypersensitivity, especially with regard to asthma and rhinitis, and as a cause of occupational dermatoses in cleaning personnel in hospitals, although no anaphylactic reaction has yet been reported. Hence, to the best of our knowledge we present the first case of anaphylaxis to chloramine-T with evidence of specific immunoglobulin E antibodies. Case presentation We describe the case of a 25-year-old Caucasian woman who was in good health and with a negative history for atopy, including no respiratory symptoms of rhinitis or asthma, and with no professional exposure to chloramine-T. She, while showering, applied a chloramine-T solution to a skin area with folliculitis on her leg, and within a few minutes developed generalized urticaria and angioedema, followed by vomiting and collapse with loss of consciousness. A skin prick test with a chloramine-T solution at 10mg/mL concentration was positive, and specific immunoglobulin E to chloramine-T was quantified at a value of 2.9 optical density as measured by the enzyme allergosorbent test technique. Conclusion The strict cause-effect relationship and the results of the skin test and the in vitro test make certain the causative role of chloramine-T in this case of anaphylaxis. This suggests that chloramine-T, based on its wide use as a disinfectant, should be considered a possible cause in anaphylaxis of unknown origin.

  3. Chloramination of Organophosphorus Pesticides Found in Drinking Water Sources

    Science.gov (United States)

    The degradation of commonly detected organophosphorus (OP) pesticides, in drinking water sources, was investigated under simulated chloramination conditions. Due to monochloramine autodecomposition, it is difficult to observe the direct reaction of monochloramine with each OP pe...

  4. Reaction of protein chloramines with DNA and nucleosides

    DEFF Research Database (Denmark)

    Hawkins, Clare L; Pattison, David I; Davies, Michael Jonathan

    2002-01-01

    Stimulated phagocyte cells produce the oxidant HOCl, via the release of the enzyme myeloperoxidase and hydrogen peroxide. HOCl is important in bacterial cell killing, but excessive or misplaced generation can damage the host tissue and may lead to the development of certain diseases such as cance......, 50-80% of the HOCl is predicted to react with histone lysine and histidine residues to yield chloramines. The yield and stability of such chloramines predicted by these modelling studies agrees well with experimental data. Decomposition of these species gives protein-derived, nitrogen......-centred radicals, probably on the lysine side chains, as characterized by the EPR and spin-trapping experiments. It is shown that isolated lysine, histidine, peptide and protein chloramines can react with plasmid DNA to cause strand breaks. The protection against such damage afforded by the radical scavengers...

  5. NDMA formation by chloramination of ranitidine: Kinetics and mechanism

    KAUST Repository

    Le Roux, Julien

    2012-10-16

    The kinetics of decomposition of the pharmaceutical ranitidine (a major precursor of NDMA) during chloramination was investigated and some decomposition byproducts were identified by using high performance liquid chromatography coupled with mass spectrometry (HPLC-MS). The reaction between monochloramine and ranitidine followed second order kinetics and was acid-catalyzed. Decomposition of ranitidine formed different byproducts depending on the applied monochloramine concentration. Most identified products were chlorinated and hydroxylated analogues of ranitidine. In excess of monochloramine, nucleophilic substitution between ranitidine and monochloramine led to byproducts that are critical intermediates involved in the formation of NDMA, for example, a carbocation formed from the decomposition of the methylfuran moiety of ranitidine. A complete mechanism is proposed to explain the high formation yield of NDMA from chloramination of ranitidine. These results are of great importance to understand the formation of NDMA by chloramination of tertiary amines. © 2012 American Chemical Society.

  6. Inhibition of tubulin polymerization by hypochlorous acid and chloramines

    OpenAIRE

    Landino, Lisa M.; Hagedorn, Tara D.; Kim, Shannon B.; Hogan, Katherine M.

    2011-01-01

    Protein thiol oxidation and modification by nitric oxide and glutathione are emerging as common mechanisms to regulate protein function and to modify protein structure. Also, thiol oxidation is a probable outcome of cellular oxidative stress and is linked to degenerative disease progression. We assessed the effect of the oxidants hypochlorous acid and chloramines on the cytoskeletal protein tubulin. Total cysteine oxidation by the oxidants was monitored by labeling tubulin with the thiol-sele...

  7. Taurine chloramine protects RAW 264.7 macrophages against hydrogen peroxide-induced apoptosis by increasing antioxidants

    OpenAIRE

    Piao, Shuyu; Cha, Young-Nam; Kim, Chaekyun

    2011-01-01

    Taurine chloramine is the major chloramine generated in activated neutrophils via the reaction between the overproduced hypochlorous acid and the stored taurine. Taurine chloramine has anti-inflammatory and cytoprotective effects in inflamed tissues by inhibiting the production of inflammatory mediators. Taurine chloramine increases heme oxygenase activity and also protects against hydrogen peroxide (H2O2)-derived necrosis in macrophages. In this study, we examined further whether taurine chl...

  8. CYCLIC VOLTAMMETRY OF ORGANIC AND INORGANIC N-CHLORAMINES IN AQUEOUS SOLUTION

    Science.gov (United States)

    Aqueous solutions or organic and inorganic N-chloramines as well as hypochlorite were examined by cyclic voltammetry at DH 8 and in strong acid (pH<2) with platinum and glassy carbon electrodes. The inorganic N-chloramines were characterized in 1 M HC104. NHC12 is reduced at abou...

  9. EFFECTS OF CHLORAMINATION AND SITE SPECIFIC ISSUES ON NANOFILTRATION FLUX LOSS AND FOULANT CHARACTERISTICS

    Science.gov (United States)

    The presence of chloramines or free ammonium ion was found to have little effect on the final specific flux and fouling cake-layer characteristics of nanofiltration membrances fed pretreated Little Miami Aquifer water. The system fed chloraminated water had the greatest amount o...

  10. Effect of X-ray Contrast Media, Chlorination, and Chloramination on Zebrafish Development

    Science.gov (United States)

    Effect of X-ray Contrast Media, Chlorination, and Chloramination on Zebrafish Development Little is known about the vertebrate developmental toxicity of chlorinated or chloraminated drinking water (DW), iodinated X-ray contrast media (ICM, a common contaminate of DW) or how the c...

  11. Relative Importance of Nitrite Oxidation by Hypochlorous Acid under Chloramination Conditions

    Science.gov (United States)

    The importance of nitrite’s oxidation by tree chlorine under chloramination conditions was evaluated using batch kinetic experiments and a chloramine model implemented into the computer program AWUASIM. The experimental data was best represented with the inclusion of a reaction b...

  12. Kinetics of the Oxidation of N-Aminopiperidine with Chloramine

    OpenAIRE

    Darwich, Chaza; Elkhatib, Mazen; Steinhauser, Georg; Delalu, Henri

    2009-01-01

    The kinetics of the oxidation of N-aminopiperidine with chloramine was studied at different temperatures, with variable concentrations of the two reactants and at a pH ranging between 12 and 13.5. The reaction showed to be involving two steps: the first corresponded to the formation of a diazene intermediate, the second to the evolution of this intermediate into numerous compounds within a complex reactional chain. The rate law of the first step was determined by the Ostwald method and found ...

  13. Draft Genome Sequences of Six Mycobacterium immunogenum, Obtained from a Chloraminated Drinking Water Distribution System Simulator

    Science.gov (United States)

    We report the draft genome sequences of six Mycobacterium immunogenum isolated from a chloraminated drinking water distribution system simulator subjected to changes in operational parameters. M. immunogenum, a rapidly growing mycobacteria previously reported as the cause of hyp...

  14. Preparation and evaluation of radio labelled recombinant human interleukin 2 by improved chloramine T method

    International Nuclear Information System (INIS)

    Iodination by improved chloramine T method was investigated. Iodine was activated with very small quantity of chloramine T (21 fold excess to iodine in molar ratio) and then recombinant interleukin-2 (rIL-2) was added to the mixture. Characteristics of the labelled rIL-2 after purification by reversed-phase HPLC was superior to those by usual chloramine T method or lactoperoxidase method. The specific activity was 0.74-1.11 MBq/μg and the immunoreactivity, biological activity and binding ability to rIL-2 receptors were similar to the intrinsic rIL-2. The improved chloramine T method is useful for iodination of unstable peptides and proteins. (author)

  15. Effects of operating conditions on trihalomethanes formation and speciation during chloramination in reclaimed water.

    Science.gov (United States)

    Wang, Fang; Gao, Baoyu; Ma, Defang; Li, Ruihua; Sun, Shenglei; Yue, Qinyan; Wang, Yan; Li, Qian

    2016-01-01

    In this study, a hybrid powdered activated carbon-membrane bioreactor (PAC-MBR) system was used to treat municipal wastewater in northern China intended for recycle. In order to control microbiological hazards in PAC-MBR effluent, chloramine was chosen as the disinfectant which could reduce the disinfection by-product yields. Effects of reaction time, chloramines dose, pH value, and bromide ion concentration on trihalomethanes (THMs) formation and speciation during chloramination of the reclaimed effluent were investigated. Study results indicated that the yield of total THMs (TTHM) increased at higher reaction time and chloramines dose. The trend of growth showed that slow reacting precursors were the main components of dissolved organic matter (DOM) in PAC-MBR effluent. THMs formation potential of PAC-MBR effluent achieved the maximum at chloramines dosage of 20 mg/L. Meanwhile, THMs formation was enhanced evidently under alkaline conditions. The yields of THMs species were in following order: CHCl3 > CHBrCl2 > CHBr2Cl > CHBr3, although in different reaction time, chloramines dose, and pH value. Furthermore, the formation of Br-THMs was promoted by the increasing concentration of bromide ion. PMID:26377970

  16. MECANISME DE FORMATION DES NITROSAMINES ET SOUS-PRODUITS HALOGENES LORS DE LA CHLORAMINATION DE CONTAMINANTS ORGANIQUES AZOTES EMERGENTS

    OpenAIRE

    Le Roux, Julien

    2011-01-01

    The aim of this study was to investigate the mechanisms of formation of N nitrosodimethylamine (NDMA) by chloramination of nitrogenous organic contaminants. First, the formation of NDMA was demonstrated by chloramination of several anthropogenic compounds such as pharmaceuticals and pesticides. Especially, the pharmaceutical ranitidine was the most important precursor of NDMA. NDMA formation by chloramination of ranitidine reaches a maximum around pH 8, and is not favored by the presence of d...

  17. Durability of amide N-chloramine biocides to ethylene oxide sterilization.

    Science.gov (United States)

    Zhao, Nan; Logsetty, Sarvesh; Liu, Song

    2012-01-01

    The objective of this work is to study the stability of three novel topical antimicrobial dressings consisting of amide N-chloramine structures against ethylene oxide sterilization. Cotton gauze samples bonded with one of three amide N-chloramine structures were subjected to standard ethylene oxide (EtO) sterilization. The amounts of amide N-chloramine structures before and after the sterilization were quantified to indicate the stabilities of these amide N-chloramine structures to the sterilization. The samples after sterilization were challenged with a clinical isolate of healthcare-associated multidrug-resistant Escherichia coli. N-Chloramine structure converted from polymethacrylamide (dressing 2) had the highest durability (89.7% retained active chlorine) toward EtO sterilization; that from hydantoin (dressing 3; 86.3% retained active chlorine) followed; and poly(N-chloroacrylamide) (dressing 1) had the lowest (64.0% retained active chlorine). After EtO sterilization, all the samples still reduced E. coli presence at 5 minutes of contact, with dressing 2 retaining a log 6 reduction. The three tested amide N-chloramine structures could all survive EtO sterilization while retaining percentages of active chlorine ranging from 64.0 to 89.7%. Dressing 2 showed the best durability, whereas dressing 1 had the poorest durability. With the remaining amounts of amide N-chloramine structures after EtO sterilization, all the dressings could still reduce E. coli numbers within 5 minutes of contact, and dressing 2 resulted in a log 6 reduction in colony count. PMID:22157019

  18. 40 CFR 141.535 - What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection?

    Science.gov (United States)

    2010-07-01

    ..., ozone, or chlorine dioxide for primary disinfection? 141.535 Section 141.535 Protection of Environment... § 141.535 What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection? If your system uses chloramines, ozone, or chlorine dioxide for primary disinfection, you must...

  19. 40 CFR 141.544 - What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection?

    Science.gov (United States)

    2010-07-01

    ..., ozone, or chlorine dioxide for primary disinfection? 141.544 Section 141.544 Protection of Environment... Benchmark § 141.544 What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection? If your system uses chloramines, ozone or chlorine dioxide for primary disinfection your system...

  20. Impact of Chloramination on the Development of Laboratory-Grown Biofilms Fed with Filter-Pretreated Groundwater

    KAUST Repository

    Ling, Fangqiong

    2013-01-01

    This study evaluated the continuous impact of monochloramine disinfection on laboratory-grown biofilms through the characterization of biofilm architecture and microbial community structure. Biofilm development and disinfection were achieved using CDC (Centers for Disease Control and Prevention) biofilm reactor systems with polyvinyl chloride (PVC) coupons as the substratum and sand filter-pretreated groundwater as the source of microbial seeding and growth nutrient. After 2 weeks of growth, the biofilms were subjected to chloramination for 8 more weeks at concentrations of 7.5±1.4 to 9.1±0.4 mg Cl2 L-1. Control reactors received no disinfection during the development of biofilms. Confocal laser scanning microscopy and image analysis indicated that chloramination could lead to 81.4-83.5% and 86.3-95.6% reduction in biofilm biomass and thickness, respectively, but could not eliminate biofilm growth. 16S rRNA gene terminal restriction fragment length polymorphism analysis indicated that microbial community structures between chloraminated and non-chloraminated biofilms exhibited different successional trends. 16S rRNA gene pyrosequencing analysis further revealed that chloramination could select members of Actinobacteria and Acidobacteria as the dominant populations, whereas natural development leads to the selection of members of Nitrospira and Bacteroidetes as dominant biofilm populations. Overall, chloramination treatment could alter the growth of multi-species biofilms on the PVC surface, shape the biofilm architecture, and select a certain microbial community that can survive or proliferate under chloramination.

  1. Pyridinium hydrobromide perbromide: a versatile catalyst for aziridination of olefins using Chloramine-T.

    Science.gov (United States)

    Ali, S I; Nikalje, M D; Sudalai, A

    1999-09-01

    [reaction: see text] Pyridinium hydrobromide perbromide (Py x HBr3) catalyzes effectively the aziridination of electron-deficient as well as electron-rich olefins using Chloramine-T (N-chloro-N-sodio-p-toluenesulfonamide) as a nitrogen source to afford the corresponding aziridines in moderate to good yields. PMID:16118868

  2. Microbial Community Dynamics of a Simulated Chloraminated Drinking Water Distribution System Subjected to Episodes of Nitrification

    Science.gov (United States)

    Bacterial populations were examined in a simulated chloraminated drinking water distribution system (i.e. loop). The loop (BW-AB-I) received chlorinated municipal water (BW-C) amended with ammonia (2mg/L monochloramine). After six years of continuous operation, the operational ...

  3. OCCURRENCE AND TOXICITY OF IODO-ACID AND IODO-THM DBPS IN CHLORAMINATED DRINKING WATER

    Science.gov (United States)

    As part of a recent Nationwide Disinfection By-Product (DBP) Occurrence Study, iodo-acids were identified for the first time as DBPs in drinking water disinfected with chloramines. The iodo-acids identified included iodoacetic acid, bromoiodoacetic acid, (E)-3-bromo-3-iodo-prope...

  4. OCCURRENCE AND TOXICITY OF IODO-ACID DISINFECTION BY-PRODUCTS IN CHLORAMINATED DRINKING WATER

    Science.gov (United States)

    As part of a recent Nationwide Disinfection By-Product (DBP) Occurrence Study, iodo-acids were identified for the first time as DBPs in drinking water disinfected with chloramines. The iodo-acids identified included iodoacetic acid (IAA), bromoiodoacetic acid, (E)-3-bromo-3-iodo...

  5. OCCURRENCE OF IODO-ACID AND IODO-THM DBPS IN U. S. CHLORAMINATED DRINKING WATERS

    Science.gov (United States)

    Iodo-acids were recently identified for the first time as DBPs in drinking water disinfected with chloramines. The iodo-acids identified included iodoacetic acid (IAA), bromoiodoacetic acid, (E)-3-bromo-3-iodo-propenoic acid, (Z)-3-bromo-3-iodo-propenoic acid, and (E)-2-iodo-3...

  6. Comparison of Microbial Communities in a Simulated Chloraminated Drinking Water Distribution System Subjected to Episodes of Nitrification

    Science.gov (United States)

    Bacterial populations were examined in a simulated chloraminated drinking water distribution system. After six months of continuous operation, coupons were incubated in CDC reactors receiving water from the simulated system to study biofilm development. The study was organized ...

  7. Simulations and Experiments Reveal the Relative Significance of the Free Chlorine/Nitrite Reaction in Chloraminated Systems

    Science.gov (United States)

    Nitrification can be a problem in distribution systems where chloramines are used as secondary disinfectants. A very rapid monochloramine residual loss is often associated with the onset of nitrification. During nitrification, ammonia-oxidizing bacteria biologically oxidize fre...

  8. Simulations and Experiments Reveal the Relative Significance of the Free Chlorine/Nitrite Reaction in Chloraminated Systems - slides

    Science.gov (United States)

    Nitrification can be a problem in distribution systems where chloramines are used as secondary disinfectants. A very rapid monochloramine residual loss is often associated with the onset of nitrification. During nitrification, ammonia-oxidizing bacteria biologically oxidize fre...

  9. Draft Genome Sequences of Six Mycobacterium immunogenum, Strains Obtained from a Chloraminated Drinking Water Distribution System Simulator

    Science.gov (United States)

    We report the draft genome sequences of six Mycobacterium immunogenum isolated from a chloraminated drinking water distribution system simulator subjected to changes in operational parameters. M. immunogenum, a rapidly growing mycobacteria previously reported as the cause of hyp...

  10. Kinetic determination of iodide by the oxidation reaction of benzidine with chloramine B

    International Nuclear Information System (INIS)

    Iodide catalyzed oxidation of benzidine with Chloramine B is studied for its possible application to kinetic determination of iodides. Based on the results of kinetic studies performed, optimal conditions for the catalytic reaction are revealed and a kinetic method for iodide determination is developed. The determination limit of iodide is 2x10-4 μg/ml. It was demonstrated that the proposed method can be used for the determination of iodides in water, soil, and kelp

  11. Radioiodination of interleukin 2 to high specific activities by the vapor-phase chloramine T method

    International Nuclear Information System (INIS)

    Recombinant human interleukin 2 (IL-2) was radioiodinated utilizing the vapor phase chloramine T method of iodination. The method is rapid, reproducible, and allows the efficient radioiodination of IL-2 to specific activities higher than those previously attained with full retention of biological activity. IL-2 radioiodinated by this method binds with high affinity to receptors present on phytohemagglutinin-stimulated peripheral blood lymphocytes and should be useful for the study of receptor structure and function

  12. Chloramination of nitrogenous contaminants (pharmaceuticals and pesticides): NDMA and halogenated DBPs formation

    KAUST Repository

    Le Roux, Julien

    2011-05-01

    Disinfection with chloramines is often used to reduce the production of regulated disinfection by-products (DBPs) such as trihalomethanes (THMs) and haloacetic acids (HAAs). However, chloramination can lead to the formation of N-nitrosamines, including N-nitrosodimethylamine (NDMA), a probable human carcinogen. Previous research used dimethylamine (DMA) as a model precursor of NDMA, but certain widely used tertiary dimethylamines (e.g. the pharmaceutical ranitidine) show much higher conversion rates to NDMA than DMA. This study investigates the NDMA formation potential of several tertiary amines including pharmaceuticals and herbicides. The reactivity of these molecules with monochloramine (NH2Cl) is studied through the formation of NDMA, and other halogenated DBPs such as haloacetonitriles (HANs) and AOX (Adsorbable Organic Halides). Several compounds investigated formed NDMA in greater amounts than DMA, revealing the importance of structural characteristics of tertiary amines for NDMA formation. Among these compounds, the pharmaceutical ranitidine showed the highest molar conversion to NDMA. The pH and dissolved oxygen content of the solution were found to play a major role for the formation of NDMA from ranitidine. NDMA was formed in higher amounts at pH around pH 8 and a lower concentration of dissolved oxygen dramatically decreased NDMA yields. These findings seem to indicate that dichloramine (NHCl2) is not the major oxidant involved in the formation of NDMA from ranitidine, results in contradiction with the reaction mechanisms proposed in the literature. Dissolved oxygen was also found to influence the formation of other oxygen-containing DBPs (i.e. trichloronitromethane and haloketones). The results of this study identify several anthropogenic precursors of NDMA, indicating that chloramination of waters impacted by these tertiary amines could lead to the formation of significant amounts of NDMA and other non-regulated DBPs of potential health concern (e

  13. Using chloramine as a coagulant aid in enhancing coagulation of Yellow River water in China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Considering that contaminated raw water mostly contains high Ammonia-N and a majority of water treatment plants use prechlorination process in China, efficiency of chloramines as a coagulant aid in enhancing coagulation was investigated by Jar stirring and pilot-scale tests, using Yellow River water containing high concentration of natural organic matters (NOM) and bromide in winter. The jar tests results showed that, compared with no preoxidation, preformed chloramine apparently decreased the turbidity of settled and filtered water with low dosage (2.0 mg/L), and the aid-coagulation efficiency was further enhanced with the increase of chlorine (Cl2) to Ammonia-N (N) ratio. Pilot-scale studies indicated that, in comparison to the case without preoxidation, the turbidity removal efficiency of flotation and filtration effluent water was significantly improved, the particle counts of filtered water were decreased 63.4%, the average rate of filter head loss was reduced 18.2%, and filter run time was prolonged 15.7%. Therefore, chloramine preoxidation may substantially enhance the particle separation efficiency.

  14. The role of aromatic precursors in the formation of haloacetamides by chloramination of dissolved organic matter

    KAUST Repository

    Le Roux, Julien

    2015-10-21

    Water treatment utilities are diversifying their water sources and often rely on waters enriched in nitrogen-containing compounds (e.g., ammonia, organic nitrogen such as amino acids). The disinfection of waters exhibiting high levels of nitrogen has been associated with the formation of nitrogenous disinfection byproducts (N-DBPs) such as haloacetonitriles (HANs) and haloacetamides (HAcAms). While the potential precursors of HANs have been extensively studied, only few investigations are available regarding the nature of HAcAm precursors. Previous research has suggested that HAcAms are hydrolysis products of HANs. Nevertheless, it has been recently suggested that HAcAms can be formed independently, especially during chloramination of humic substances. When used as a disinfectant, monochloramine can also be a source of nitrogen for N-DBPs. This study investigated the role of aromatic organic matter in the formation of N-DBPs (HAcAms and HANs) upon chloramination. Formation kinetics were performed from various fractions of organic matter isolated from surface waters or treated wastewater effluents. Experiments were conducted with 15N-labeled monochloramine (15NH2Cl) to trace the origin of nitrogen. N-DBP formation showed a two-step profile: (1) a rapid formation following second-order reaction kinetics and incorporating nitrogen atom originating from the organic matrix (e.g., amine groups); and (2) a slower and linear increase correlated with exposure to chloramines, incorporating inorganic nitrogen (15N) from 15NH2Cl into aromatic moieties. Organic matter isolates showing high aromatic character (i.e., high SUVA) exhibited high reactivity characterized by a major incorporation of 15N in N-DBPs. A significantly lower incorporation was observed for low-aromatic-content organic matter. 15N-DCAcAm and 15N-DCAN formations exhibited a linear correlation, suggesting a similar behavior of 15N incorporation as SUVA increases. Chloramination of aromatic model compounds (i

  15. Role of NOM molecular size on iodo-trihalomethane formation during chlorination and chloramination.

    Science.gov (United States)

    Zhang, Jie; Chen, Dan-Dan; Li, Lei; Li, Wen-Wei; Mu, Yang; Yu, Han-Qing

    2016-10-01

    Natural organic matter (NOM) is the major precursor for the generation of disinfection byproducts (DBPs) during disinfection, but the role of the NOM molecular size on the formation of iodinated DBPs (I-DBPs) is still unclear. The objective of this study was to evaluate the function of the NOM molecular size on the formation of iodo-trihalomethane (I-THMs) during chlorination and chloramination. Humic acid was adopted as the NOM matrix and fractionated into four molecular weight (MW) groups. Various parameters, including iodide, bromide, NOM concentrations, pH, and pre-chlorination time, were investigated for each MW fraction. During chlorination, high MW fractions (i.e., MW > 100 K Da and 50 K < MW < K00 K Da) produced more I-THMs compared with small MW fractions (i.e., MW < 3 K Da and 3 K < MW < 50 K Da). With the increase in the I(-) or NOM concentration, the formation of I-THMs increased for small MW fractions, while a slight reduction occurred for high MW fractions during chlorination. Higher pH resulted in more I-THM formation for small MW fractions, while the opposite was true for high MW fractions during chlorination. Compared to small MW fractions, bromide was relatively more reactive with high MW fractions in the formation of I-THMs during chlorination. During chloramination, the I-THM yields decreased with the increasing NOM concentration for high MW fractions. The concentration of bromine-containing I-THMs decreased with increasing pH for all MW fractions during chloramination. Additionally, with the prolongation of pre-chlorination time, the total amount of I-THMs decreased remarkably for MWs higher than 3 K Da, while a slight change for MW lower than 3 K Da occurred during chloramination. The results from this study suggest that the molecular weight of the NOM plays an important role in the formation of I-THMs during chlorination and chloramination. PMID:27423047

  16. Acid-base and ionic fluxes in rainbow trout (Oncorhynchus mykiss) during exposure to chloramine-T

    Energy Technology Data Exchange (ETDEWEB)

    Powell, M.D.; Perry, S.F. [Department of Biology, University of Ottawa, 30 Marie Curie Ottawa, Ontario, K1N 6N5 (Canada)

    1998-09-01

    The effects of chloramine-T and its degradation products, sodium hypochlorite (NaOCl) and para-toluenesulphonamide (pTSA), on whole body acid-base and branchial and renal ion (Na{sup +}and Cl{sup -}) fluxes were examined in rainbow trout (Oncorhynchus mykiss). Exposure to chloramine-T (3.5 h, 18 mg l{sup -1}) resulted in increases in plasma total CO{sub 2} but no coincident rise in P{sub a}CO{sub 2} or reduction in blood pH. Exposure of fish to 2, 9 or 18 mg l{sup -1} chloramine-T (3.5 h duration) resulted in a reduction in net acid uptake suggesting the development of a metabolic alkalosis. Exposure to the chloramine-T breakdown product pTSA (dissolved in DMSO) resulted in increased net acid uptake (decreased acid excretion) suggesting a metabolic acidosis. Whole body ion fluxes demonstrated increases in the losses of both Na{sup +}and Cl{sup -} with chloramine-T, NaOCl and pTSA. However, the effect of DMSO alone could not be isolated. Confirmatory studies using fish in which the urinary bladder (to allow collection of urine) and dorsal aorta (to allow injection of [{sup 14}C]polyethylene glycol 4000 ([{sup 14}C]PEG), an extracellular fluid marker) were catheterised, revealed that changes in whole body ion fluxes during chloramine-T exposure could not be explained by increased renal efflux through urine flow, glomerular filtration or renal clearance. Branchial effluxes of [{sup 14}C]PEG were not significantly affected by chloramine-T exposure suggesting that the changes in whole body ionic fluxes were caused by transcellular rather than paracellular processes. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  17. Formation and cytotoxicity of a new disinfection by-product (DBP) phenazine by chloramination of water containing diphenylamine

    Institute of Scientific and Technical Information of China (English)

    Wenjun Zhou; Linjie Lou; Lifang Zhu; Zhimin Li; Lizhong Zhu

    2012-01-01

    Disinfection by-products (DBPs) in drinking water have caused worldwide concern due to their potential earcinogenic effects.The formation of phenazine from diphenylamine (DPhA) chloramination was studied and its cytotoxicities for two human cancer cells were also investigated.Phenazine was detected synchronously with the consumption of DPhA by chloramination,which further confirmed that the new DBP phenazine can be produced along with N-nitrosodiphenylamine (NDPhA) from DPhA chloramination.The formation of phenazine had a maximum molar yield with solution pH increasing from 5.0 to 9.0,with phernazine as the main product for DPhA chloramination at lower pH,but higher pH favored the formation of NDPhA.Thus,solution pH is the key factor in controlling the formation of phenazine and NDPhA.Both the initial DPhA and chloramine concentrations did not show a significant effect on the molar yields of phenazine,although increasing the chloramine concentration could speed up the reacdon rate of DPhA with chloramines.The cytotoxicity assays showed that phenazine had significant cell-specific toxicity towards T24 (bladder cancer cell lines) and HepG2 (hepatic tumor cell lines) cells with IC50 values of 0.50 and 2.04 mmol/L,respectively,and T24 ceils being more sensitive to phenazine than HepG2 ceils.The IC50 values of phenazine,DPhA,and NDPhA for T24 cells were of the same order of magnitude and the cytotoxicity of phenazine for T24 cells was slightly lower than that of NDPhA (IC50,0.16 mmol/L),suggesting that phenazine in drinking water may have an adverse effect on human health.

  18. Succession of Biofilm Microbial Community during Nitrification in Lab-Scale Reactors Simulating Chloraminated Drinking Water Distribution System Conditions: the Impact of Simultaneously Increasing Monochloramine and Chlorine to Nitrogen Mass Ratios

    Science.gov (United States)

    Chloramination has been shown to promote nitrifying bacteria and 30 to 63% of utility plants using secondary chloramine disinfection experience nitrification episodes. Although nitrifying bacteria are not considered human pathogens, nitrification can affect drinking water qualit...

  19. Effect of chloramine-T labeling conditions on the stability of monoclonal antibodies and their fragments

    International Nuclear Information System (INIS)

    Rapid in vivo degradation of radioiodinated monoclonal antibodies (MAb) has been reported. Conditions for radioiodination have varied. The purposes of this study were to compare the stability of MAb and their fragments when iodinated with chloramine-T (CT) under different conditions, and to compare methods for quality assessment of the radioiodinated molecules. A B-cell lymphoma MAb (Lym-1, IgG2a) and its FAb fragment, and a mammary cancer MAb(B6.01, IgG1) and its F(Ab')/sub 2/ fragment were iodinated with I-125 at CT:AB and I:Ab ratios of 1:1 and 1:10. Molecular sieving (TSK-3000) high performance liquid chromatography (HPLC), cellulose acetate electrophoresis (CAE) at 11 and 45 minutes and solid phase immunoreactivity (IRA) were used to observe stability of the molecules when stored at 40C. Radiochemical yield was greater than 95% in all instances. Iodination at CT:Ab and I:Ab ratios of 1:1 induced progressive degradation in all species which was most marked for the fragments. Iodination at CT:Ab and I:Ab ratios of 1:10 resulted in no observable degradation over 21 days. There was no significant difference in degradation between the IgG2a and IgG1 antibody when iodinated under identical circumstances. HPLC, CAE for 11 minutes and IRA, but not CAE for 45 minutes, revealed comparable changes. The authors conclude that lesser amounts of chloramine-T can be used to iodinate MAb and their fragments without loss of radiochemical efficiency and with improved stability of the species. MAb fragments are more vulnerable to chloramine-T. These observations may explain, at least in part, rapid in vivo degradation of radioiodinated MAb

  20. Chlorine transfert reactions between chloramine and piperidine: Kinetic reactivity and characterization in a Raschig medium

    OpenAIRE

    Darwich, Chaza; Elkhatib, Mazen; Steinhauser, Georg; Delalu, Henri

    2009-01-01

    the kinetics of the Cl-transfert reaction between chloramine and piperidine in a Raschig medium was studied at various temperatures, with variable concentrations of the two reactants. The influence of the pH on the interaction was examined at a pH ranging between 8.25 and 12.89. The Cl-transfert reaction resulted in the formation of 1-chloropiperidine, which, in the presence of NaOH, underwent a dehydrohalogenation leading to an endocyclic imine derivative: 2,3,4,5-tetrahydropyridine. The kin...

  1. Chloramine-T as labelling agent for oleic acid and olive oil

    International Nuclear Information System (INIS)

    Olive oil and its main constituent, oleic acid, have been labelled with 125I using chloramine-T (CAT) as an oxidizing agent. The maximum yields of labelling in different organic solvents were found to vary between 10 to 50% for oleic acid. The values for olive oil were 70% of those of oleic acid. The labelled compounds were stable in organic solvents except acetone where they start to decompose after 20 minutes of starting the experiments. The low yields could be attributed partly to a possible labelling of CAT or to the reaction of CAT with labelled compounds or their precursors. (author)

  2. Iodine-Catalyzed Decarboxylative Amidation of β,γ-Unsaturated Carboxylic Acids with Chloramine Salts Leading to Allylic Amides.

    Science.gov (United States)

    Kiyokawa, Kensuke; Kojima, Takumi; Hishikawa, Yusuke; Minakata, Satoshi

    2015-10-26

    The iodine-catalyzed decarboxylative amidation of β,γ-unsaturated carboxylic acids with chloramine salts is described. This method enables the regioselective synthesis of allylic amides from various types of β,γ-unsaturated carboxylic acids containing substituents at the α- and β-positions. In the reaction, N-iodo-N-chloroamides, generated by the reaction of a chloramine salt with I2 , function as a key active species. The reaction provides an attractive alternative to existing methods for the synthesis of useful secondary allylic amine derivatives. PMID:26493878

  3. Using micro-quantity of chloramine T in chicken pro-latin labelling and radioimmunoassay

    International Nuclear Information System (INIS)

    A radioimmunoassay was developed for measurement of chicken plasma prolactin. The assay used chPRL(AFP-10328B) as reference standard, chPRL(AFP-4444B) as the radio labelled ligand, rabbit anti-chicken PRL (AFP-151040789) as first antibody, and donkey anti-rabbit IgG antiserum as second antibody. For iodide ratio labelling of chicken PRL, a modified chloramine T method which reduced the amount of chloramine T and omitted sodium metabisulfite, and produced the labelled hormone with a specific activity of 29μCi/μg was used. The assay sensitivity was 0.34 ng/ml. the ED75, ED50 and ED25 of standard curve were 1.30, 3.71 and 10.60 ng/ml, respectively. Both coefficients of variations between and within assay were less than 15%. Serial dilutions of chicken samples showed a parallel inhibition curve to that of the standards. Plasma PRL concentrations of samples from hens at different reproductive states measured by this assay revealed significant differences and rational changing trends. These results validate the assay

  4. Comparison of Microbial Communities in a Simulated Chloraminated Drinking Water Distribution System Subjected to Episodes of Nitrification (poster)

    Science.gov (United States)

    Bacterial populations were examined in a simulated chloraminated drinking water distribution system (i.e. PVC pipe loop). After six months of continuous operation, coupons were incubated in CDC reactors receiving water from the simulated system to study biofilm development. The s...

  5. Preparation of bromine-77 labelled monoclonal anti-hPLAP [human placental alkaline phosphatase] antibody using chloramine-T

    International Nuclear Information System (INIS)

    A tumor-associated monoclonal antibody, named 7E8 and raised against human placental alkaline phosphatase (hPLAP), is labelled with bromine-77 by means of chloramine-T. The paper describes optimum radiobromination conditions resulting in 34 % radiochemical yield of labelled antibody with more than 90 % immunoreactivity. (author)

  6. OCCURRENCE OF IODO-ACID AND IODO-THM DISINFECTION BY-PRODUCTS IN CHLORAMINATED DRINKING WATER

    Science.gov (United States)

    Iodo-acids were recently identified for the first time as DBPs in drinking water disinfected with chloramines. The iodo-acids identified included iodoacetic acid (IAA), bromoiodoacetic acid, (E)-3-bromo-3-iodo-propenoic acid, (Z)-3-bromo-3-iodo-propenoic acid, and (E)-2-iodo-3...

  7. Optimization of the chloramine T method for radioiodination of prostate gland by acid phosphatase

    International Nuclear Information System (INIS)

    Optimal conditions for preparation of [125I]-labelled human prostatic acid phosphatase (PAP) by chloramin T method were developed which make it possible to increase the radiochemical yield and immunoreactivity of labelled PAP. The influence of buffer system, pH of reaction mixture and molarity of borate buffer was investigated. Iodination in 0.2 M borate buffer, pH 8.0 make it possible to prepare [125I]-PAP with 90-98 immunoreactivity. Under storage of labelled PAP during 2 month immunoreactivity is decreased only by 10%. On the base of prepared 125I]-PAP high-sensitive competitive radioimmunoassay of PAP in human serum have developed

  8. Microbial community response to chlorine conversion in a chloraminated drinking water distribution system.

    Science.gov (United States)

    Wang, Hong; Proctor, Caitlin R; Edwards, Marc A; Pryor, Marsha; Santo Domingo, Jorge W; Ryu, Hodon; Camper, Anne K; Olson, Andrew; Pruden, Amy

    2014-09-16

    Temporary conversion to chlorine (i.e., "chlorine burn") is a common approach to controlling nitrification in chloraminated drinking water distribution systems, yet its effectiveness and mode(s) of action are not fully understood. This study characterized occurrence of nitrifying populations before, during and after a chlorine burn at 46 sites in a chloraminated distribution system with varying pipe materials and levels of observed nitrification. Quantitative polymerase chain reaction analysis of gene markers present in nitrifying populations indicated higher frequency of detection of ammonia oxidizing bacteria (AOB) (72% of samples) relative to ammonia oxidizing archaea (AOA) (28% of samples). Nitrospira nitrite oxidizing bacteria (NOB) were detected at 45% of samples, while presence of Nitrobacter NOB could not be confirmed at any of the samples. During the chlorine burn, the numbers of AOA, AOB, and Nitrospira greatly reduced (i.e., 0.8-2.4 log). However, rapid and continued regrowth of AOB and Nitrospira were observed along with nitrite production in the bulk water within four months after the chlorine burn, and nitrification outbreaks appeared to worsen 6-12 months later, even after adopting a twice annual burn program. Although high throughput sequencing of 16S rRNA genes revealed a distinct community shift and higher diversity index during the chlorine burn, it steadily returned towards a condition more similar to pre-burn than burn stage. Significant factors associated with nitrifier and microbial community composition included water age and sampling location type, but not pipe material. Overall, these results indicate that there is limited long-term effect of chlorine burns on nitrifying populations and the broader microbial community. PMID:25118569

  9. Occurrences of nitrosamines in chlorinated and chloraminated drinking water in three representative cities, China

    International Nuclear Information System (INIS)

    An investigation of the occurrence of nine nitrosamines in drinking water following different water treatment processes was conducted using samples from seven drinking water treatment plants in three cities and tap waters in one city in China. The total nitrosamine levels ranged from not detected (n.d.) to 43.45 ng/L. The species and concentrations of the nine nitrosamines varied with disinfection methods and source waters. N-nitrosodimethylamine (NDMA), which is the nitrosamines of greatest concern, was identified in raw water, disinfecting water, finished water and tap water samples, ranging from 0.8 to 21.6, 0.12 to 24.2, n.d. to 8.8, and n.d. to 13.3 ng/L, respectively. Chloramination alone produced the most significant amounts of NDMA, while ozonation followed by chloramination led to moderately reduced levels. Additionally, chlorination produced relatively less NDMA, while low pressure ultraviolet radiation followed by chlorination could also significantly reduce them. Total organic carbon is one of the most important factors influencing nitrosamines formation in disinfecting water. In contrast, the addition of chlorine following any other disinfection was found to increase the formation of the other eight species of nitrosamines. The three nitrosamines recommended for monitoring by the US EPA were detected in the tap water samples, but most were present at levels below those that pose a risk to human health. Nevertheless, the occurrence and concentration of nitrosamines regulated in the Drinking Water Contaminant Candidate List could cause some potential human effects and therefore warrant attention. Highlights: ► Nitrosamines in disinfected drinking water in three Chinese cities were investigated. ► Some nitrosamines could be detected in raw water. ► Advanced treatment affects nitrosamine levels both positively and negatively. ► Organic matters contribute to increased nitrosamine level. ► Nitrosamine levels in this study were below the EPA MAC but

  10. Comparative Genomic Analysis of Nontuberculous Mycobacteria (NTM) and Environmental Isolates Associated with a Simulated Chloraminated Drinking Water Distribution System Subjected to Episodes of Nitrification - poster #2168

    Science.gov (United States)

    Bacterial populations were examined in a simulated chloraminated drinking water distribution system. After six months of continuous operation, coupons were incubated in CDC reactors receiving water from the simulated system to study biofilm development. The distribution system wa...

  11. Comparative Genomic Analysis of Nontuberculous Mycobacteria (NTM) and Environmental isolates associated with a Simulated Chloraminated Drinking Water Distribution System Subjected to Episodes of Nitrification

    Science.gov (United States)

    Bacterial populations were examined in a simulated chloraminated drinking water distribution system. After six months of continuous operation, coupons were incubated in CDC reactors receiving water from the simulated system to study biofilm development. The distribution system ...

  12. Microbial Community Dynamics of an Urban Drinking Water Distribution System Subjected to Phases of Chloramination and Chlorination Treatments

    OpenAIRE

    Hwang, Chiachi; Ling, Fangqiong; Andersen, Gary L.; LeChevallier, Mark W.; Liu, Wen-Tso

    2012-01-01

    Water utilities in parts of the U.S. control microbial regrowth in drinking water distribution systems (DWDS) by alternating postdisinfection methods between chlorination and chloramination. To examine how this strategy influences drinking water microbial communities, an urban DWDS (population ≅ 40,000) with groundwater as the source water was studied for approximately 2 years. Water samples were collected at five locations in the network at different seasons and analyzed for their chemical a...

  13. Effects of ozone and ozone/peroxide pretreatments on disinfection byproduct formation during subsequent chlorination and chloramination.

    Science.gov (United States)

    Yang, Xin; Peng, Jinfeng; Chen, Baiyang; Guo, Wanhong; Liang, Yongmei; Liu, Wei; Liu, Lu

    2012-11-15

    Ozone (O3) and ozone/hydrogen peroxide (O3/H2O2) can be used in water treatment facilities to remove many organic micropollutants with taste, odor, and color implications. The effects of O3 and O3/H2O2 on the formation of disinfection byproducts (DBPs) in subsequent chlorination and chloramination processes, however, are not well determined. In this study, we compared the yields of a series of regulated and emerging DBPs during sequenced O3-Cl2, O3/H2O2-Cl2, O3-NH2Cl, and O3/H2O2-NH2Cl oxidation of 11 samples, each with different hydrophobicity, bromide concentration, soluble microbial products, and humic substances. For most water, pretreatment with O3 and O3/H2O2 increased the formation of chloral hydrate (CH), trichloronitromethane (TCNM) and haloketones (HKs) but lowered the yields of haloacetonitriles (HANs) during chlorination processes. Compared with O3 alone, O3/H2O2 in combination generated more CH and HKs during chlorination, and their extents of formation appeared to depend on the O3 doses. In terms of chloramination, both O3 and O3/H2O2 reduced THM, HAA, and HAN formation significantly without increasing CH, TCNM, or HKs. These results suggest that O3 or O3/H2O2 pretreatments may provide some benefits for the chloramination process in controlling regulated and emerging DBPs in waters without high bromide content. PMID:23009791

  14. Oxidation of Tetracaine Hydrochloride by Chloramine-B in Acid Medium: Kinetic Modeling

    Directory of Open Access Journals (Sweden)

    Jayachamarajapura Pranesh Shubha

    2014-01-01

    Full Text Available Tetracaine hydrochloride (TCH is one of the potent local anaesthetics. A kinetic study of oxidation of tetracaine hydrochloride by sodium N-chlorobenzenesulfonamide (chloramine-B or CAB has been carried in HClO4 medium at 303 K. The rate shows first-order dependence on [CAB]o, shows fractional–order dependence on [substrate]o, and is self-governing on acid concentration. Decrease of dielectric constant of the medium, by adding methanol, increased the rate. Variation of ionic strength and addition of benzenesulfonamide or NaCl have no significant effect on the rate. The reaction was studied at different temperatures and the activation parameters have been evaluated. The stoichiometry of the reaction was found to be 1 : 5 and the oxidation products were identified by spectral analysis. The conjugate free acid C6H5SO2NHCl of CAB is postulated as the reactive oxidizing species. The observed results have been explained by plausible mechanism and the related rate law has been deduced.

  15. Spectrophotometric determination of bio-active compounds with chloramine-T and gallocyanine.

    Science.gov (United States)

    Sastry, C S; Srinivas, K R; Prasad, K M

    1996-10-01

    A simple, sensitive and selective method for the spectrophotometric determination of drugs, viz., sulphamethoxazole, tetracycline HCl, amidopyrine, nifurtimox and isoniazid and biologically important amino acids, cysteine, aspartic acid and arginine based on their reactivity with chloramine-T (CAT) is proposed. The method involves the addition of excess CAT of a known concentration in the presence of 0.25 M HCl and the determination of the unreacted CAT by measurement of the decrease in the absorbance of the dye, gallocyanine (lambda(max): 540 nm), the most suitable of several dyes that were tested. This method was applied to the determination of drug contents in pharmaceutical formulations and to the measurement of the aspartic acid content of some protein hydrolysates. The method is useful for the determination of the target compounds in microgram quantities from 0.4-5.6 microg mL(-1) with the exceptions of arginine (1.0-8.0 microg mL(-1)) and nifurtimox (0.8-5.6 microg mL(-1)). Standard deviations were typically 0.5 mg per dose (RSD 0.5-1.2%). No interferences were observed from common excipients in formulations, and detailed interference studies of other amino acids in the determination of cysteine, aspartic acid and arginine are reported. The validity of the method was tested against spectrophotometric and titrimetric reference methods. Recoveries were 99.8-102.1%. PMID:18966644

  16. Kinetics and Mechanistic Chemistry of Oxidation of Butacaine Sulfate by Chloramine-B in Acid Medium

    Energy Technology Data Exchange (ETDEWEB)

    Shubha, Jayachamarajapura Pranesh; Kotabagi, Vinutha [Bosco Institute of Technology, Bangalore (India); Puttaswamy [Bangalore Univ., Bangalore (India)

    2012-11-15

    Butacaine sulfate is an ester of p-aminobenzoic acid which has been widely used as a local anaesthetic and it is a long standing agent particularly for spinal anaesthesia. For this reason, a kinetic study of oxidation of butacaine sulfate by sodium N-chlorobenzenesulfonamide (chloramine-B or CAB) has been carried out in HClO{sub 4} medium at 303 K in order to explore this redox system mechanistic chemistry. The rate shows a first-order dependence on both [CAB]{sub o}, and [substrate]{sub o}, and a fractional-order dependence on acid concentration. Decrease of dielectric constant of the medium, by adding methanol, increases the rate of the reaction. Variation of ionic strength and addition of benzenesulfonamide or NaCl have no significant effect on the rate. The reaction was studied at different temperatures and the activation parameters have been evaluated. The stoichiometry of the reaction has been found to be 1:2 and the oxidation products have been identified by spectral analysis. The observed results have been explained by plausible mechanism and the related rate law has been deduced.

  17. Influence Factors of Chloramine Decay in Bulk Water%氯胺在管网中水相衰减影响因素研究

    Institute of Scientific and Technical Information of China (English)

    张永吉; 曾果; 周玲玲; 宋正国; 邓慧萍

    2012-01-01

    Water quality parameters including chlorine to ammonia nitrogen application ratio w(Cl)∶w(N),initial chloramine concentration,organic compound level,nitrite concentration,temperature and pH,which affect chloramines decay,are investigated in pure water and the water of a distribution system.Results show that chloramine can autodecompose in pure water.w(Cl)∶w(N) and initial chloramine concentration influence its decay rate.The rate of chloramine decay is higher in bulk water of the distribution system than that in pure water.Chloramine is more stable with w Cl∶w(N)=4∶1 than that of w(Cl)∶w(N)=3∶1.Initial chloramine concentration is an important factor inducing the high rate of chloramines decay with high initial chloramine concentration.The rate of Chloramines decay increases with increasing organic compound and nitrite concentration.The temperature inpacts on the rate of chloramines decay,which means high decay rate in bulk water with increasing temperature.In addition,the reaction of chloramines decay is a type of acid-catalysis,and lower pH elevates the rate of chloramines decay.%以纯水和管网水为研究对象,分别考察了氯氨比、氯胺质量浓度、总有机碳(total organic carbon,TOC)浓度、NO2--N质量浓度、温度θ和pH等水质参数对氯胺衰减的影响.研究结果表明,氯胺在纯水中存在自衰减现象,氯氨比和初始氯胺质量浓度对其自衰减都有一定影响.管网水中氯胺的衰减速率则明显大于同条件下纯水中氯胺的衰减速率,w(Cl)∶w(N)=4∶1的氯氨比w(Cl)∶w(N)=3∶1的氯胺具有更好的稳定性.氯胺初始质量浓度是氯胺衰减的重要因素,初始质量浓度越大,氯胺衰减的速率越快;水中有机物和NO2--N质量浓度的增加会提高氯胺衰减速率;温度对氯胺的衰减有明显影响,随温度升高,氯胺在水相中消耗变快;氯胺的衰减属于酸催化反应,pH的降低会增加氯胺的衰减速率.

  18. Radioiodination of olive oil VIA iodinemonochloride and chloramine-T in organic medium

    International Nuclear Information System (INIS)

    Olive oil is one of the neutral oils, composed of many fatty acids, some are saturated while others are unsaturated. This paper reports the results of comparative radioiodination study performed using iodine mono chloride I CI and chloramine-T as oxidising agents in organic solvents. On labelling using 125 I Cl in different solvents, benzene, petroleum ether, diethyl ether and n-heptane a yield of > 70% was found in case of diethyl ether within 5 minutes for olive oil while it was 80% for oleic acid under the same conditions. In case of benzene as a solvent the labelling yield was reached a maximum labelling of 37% and > 43% for olive oil and oleic acid respectively within 60 minutes after which labelling decreased with time. So benzene was chosen as the solvent for labelling of oleic acid using commercial 125 I Cl to compare with I CI prepared in the laboratory. Using unpurified commercial 125 I CI as labelling agent a yield of 65% was reached within 15 minutes while purified commercial I CI gave ∼ 40% after 15 minutes and 22% using the prepared 125 I CI. This reduction in the yield in case of purified I CI indicates that other iodine species I2, I-3 and I OH plays great role in the labelling process depending on the medium used. Further studies were carried out using method for labelling olive oil as well as oleic acid in organic solvents n-heptane, benzene, acetone and methyl n-butyl ketone (MnBK) at a temperature just below the boiling point of each solvent. A maximum labelling yield of 28% for olive oil in the n-heptane solvent against 50% labelling yield of oleic acid under the same conditions of solvent, temperature and reaction time. Using actions as solvent it was found that the labelling yield decreases with reaction time.4 fig

  19. Formation of disinfection byproducts upon chlorine dioxide preoxidation followed by chlorination or chloramination of natural organic matter.

    Science.gov (United States)

    Yang, Xin; Guo, Wanhong; Lee, Wontae

    2013-06-01

    Chlorine dioxide (ClO2) is often used as an oxidant to remove taste, odor and color during water treatment. Due to the concerns of the chlorite formation, chlorination or chloramination is often applied after ClO2 preoxidation. We investigated the formation of regulated and emerging disinfection byproducts (DBPs) in sequential ClO2-chlorination and ClO2-chloramination processes. To clarify the relationship between the formation of DBPs and the characteristics of natural organic matter (NOM), changes in the properties of NOM before and after ClO2 oxidation were characterized by fluorescence, Fourier transform infrared spectroscopy (FTIR), and size and resin fractionation techniques. ClO2 preoxidation destroyed the aromatic and conjugated structures of NOM and transformed large aromatic and long aliphatic chain organics to small and hydrophilic organics. Treatment with ClO2 alone did not produce significant amount of trihalomethanes (THMs) and haloacetic acids (HAAs), but produced chlorite. ClO2 preoxidation reduced THMs, HAAs, haloacetonitriles (HANs) and chloral hydrate (CH) during subsequent chlorination, but no reduction of THMs was observed during chloramination. Increasing ClO2 doses enhanced the reduction of most DBPs except halonitromethanes (HNMs) and haloketones (HKs). The presence of bromide increased the formation of total amount of DBPs and also shifted DBPs to more brominated ones. Bromine incorporation was higher in ClO2 treated samples. The results indicated that ClO2 preoxidation prior to chlorination is applicable for control of THM, HAA and HAN in both pristine and polluted waters, but chlorite formation is a concern and HNMs and HKs are not effectively controlled by ClO2 preoxidation. PMID:23312737

  20. Changes in dissolved organic matter fluorescence and disinfection byproduct formation from UV and subsequent chlorination/chloramination

    Energy Technology Data Exchange (ETDEWEB)

    Lyon, Bonnie A.; Cory, Rose M.; Weinberg, Howard S., E-mail: howard_weinberg@unc.edu

    2014-01-15

    Highlights: • DBP formation from UV-chlorine/chloramine drinking water treatment was measured. • The effect of UV on DBP precursors was evaluated by fluorescence and PARAFAC. • UV alone decreased protein/tryptophan- and humic-like fluorescence. • Loss of two components correlated with cyanogen chloride formation (R{sup 2} = 0.79–0.91). • Loss of the components also correlated with chloral hydrate formation (R{sup 2} = 0.95–1.000). -- Abstract: Ultraviolet (UV) irradiation is being increasingly used to help drinking water utilities meet finished water quality regulations, but its influence on disinfection byproduct (DBP) precursors and DBP formation is not completely understood. This study investigated the effect of medium pressure (MP) UV combined with chlorination/chloramination on the fluorescent fraction of dissolved organic matter (DOM) isolated from a United States surface water with median total organic carbon content. Parallel factor analysis was used to understand how UV may alter the capacity of DOM to form DBPs of potential human health concern. The production of chloral hydrate and cyanogen chloride from MP UV followed by chlorine or chloramine, respectively, correlated with a decrease in fluorescence intensity of a protein/tryptophan-like component (R{sup 2} = 0.79–0.99) and a humic-like component (R{sup 2} = 0.91–1.00). This suggests that the UV-induced precursors to these compounds originated from DOM with similar characteristics to these components. The fluorescent DOM components identified in this study are similar to reoccurring components that have been previously identified in a range of raw and treated waters, and this work demonstrates the value of using fluorescence analysis of DOM to understand the relationships between DOM source and DBP formation under a range of treatment conditions.

  1. Formation of emerging DBPs from the chlorination and chloramination of seawater algal organic matter and related model compounds

    KAUST Repository

    Nihemaiti, Maolida

    2014-05-01

    Limited studies focused on reactions occurring during disinfection and oxidation processes of seawater. The aim of this work was to investigate disinfection by-products (DBPs) formation from the chlorination and chloramination of seawater algal organic matter and related model compounds. Simulated algal blooms directly growing in Red Sea, red tide samples collected during an algal bloom event and Hymenomonas sp. monoculture were studied as algal organic matter sources. Experiments were conducted in synthetic seawater containing bromide ion. A variety of DBPs was formed from the chlorination and chloramination of algal organic matter. Brominated DBPs (bromoform, DBAA, DBAN and DBAcAm) were the dominant species. Iodinated DBPs (CIAcAm and iodinated THMs) were detected, which are known to be highly toxic compared to their chlorinated or brominated analogues. Algal organic matter was found to incorporate important precursors of nitrogenous DBPs (N-DBPs), which have been reported to be more toxic than regulated THMs and HAAs. Isotopically-labeled monochloramine (15N- NH2Cl) was used in order to investigate the nitrogen source in N-DBPs. High formation of N-DBPs was found from Hymenomonas sp. sample in exponential growth phase, which was enriched in nitrogen-containing organic compounds. High inorganic nitrogen incorporation was found from the algal samples enriched in humic-like compounds. HAcAms formation was studied from chlorination and chloramination of amino acids. Asparagine, aspartic acid and other amino acids with an aromatic structure were found to be important precursors of HAcAms and DCAN. Factors affecting HAcAms formation (Cl2/ amino acid molar ratio and pH) were evaluated. Studies on the formation kinetics of DCAcAm and DCAN from asparagine suggested a rapid formation of DCAcAm from organic nitrogen (amide group) and a slower incorporation of inorganic nitrogen coming from monochloramine to form DCAN. High amounts of DCAN and DCAcAm were detected from the

  2. Secondary radicals derived from chloramines of apolipoprotein B-100 contribute to HOCl-induced lipid peroxidation of low-density lipoproteins

    DEFF Research Database (Denmark)

    Hazell, L J; Davies, Michael Jonathan; Stocker, R

    depleted of alpha-tocopherol. The initial reaction of low concentrations of HOCl (400-fold or 800-fold molar excess) with LDL therefore seems to occur primarily by two-electron reactions with side-chain sites on apolipoprotein B-100. Some of the initial reaction products, identified as lysine......-residue-derived chloramines, subsequently undergo homolytic (one-electron) reactions to give radicals that initiate antioxidant consumption and lipid oxidation via tocopherol-mediated peroxidation. The identification of these chloramines, and the radicals derived from them, as initiating agents in LDL lipid peroxidation...

  3. Characterization of iodinated disinfection by-products in chlorinated and chloraminated waters using Orbitrap based gas chromatography-mass spectrometry.

    Science.gov (United States)

    Postigo, Cristina; Cojocariu, Cristian I; Richardson, Susan D; Silcock, Paul J; Barcelo, Damia

    2016-05-01

    Recent developments in gas chromatography (GC)-mass spectrometry (MS) have opened up the possibility to use the high resolution-accurate mass (HRAM) Orbitrap mass analyzer to further characterize the volatile and semivolatile fractions of environmental samples. This work describes the utilization of GC Orbitrap MS technology to characterize iodine-containing disinfection by-products (iodo-DBPs) in chlorinated and chloraminated DBP mixture concentrates. These DBP mixtures were generated in lab-scale disinfection reactions using Llobregat river water and solutions containing Nordic Lake natural organic matter (NOM). The DBPs generated were concentrated using XAD resins, and extracts obtained were analyzed in full scan mode with the GC Orbitrap MS. Integration of high resolution accurate mass information and fragment rationalization allowed the characterization of up to 11 different iodo-DBPs in the water extracts analyzed, including one new iodo-DBP reported for the first time. Overall, formation of iodo-DBPs was enhanced during chloramination reactions. As expected, NOM characteristics and iodide and bromide content of the tested waters affected the amount and type of iodo-DBPs generated. Graphical Abstract Characterization of iodo-DBPs in DBP mixtures based on high resolution accurate mass data obtained by means of GC Orbitrap MS analysis. PMID:27007731

  4. Evidence for rapid inter- and intramolecular chlorine transfer reactions of histamine and carnosine chloramines: implications for the prevention of hypochlorous-acid-mediated damage.

    Science.gov (United States)

    Pattison, David I; Davies, Michael J

    2006-07-01

    Hypochlorous acid (HOCl) is a powerful oxidant generated from H(2)O(2) and Cl(-) by the heme enzyme myeloperoxidase, which is released from activated leukocytes. HOCl possesses potent antibacterial properties, but excessive production can lead to host tissue damage that is implicated in a wide range of human diseases (e.g., atherosclerosis). Histamine and carnosine have been proposed as protective agents against such damage. However, as recent studies have shown that histidine-containing compounds readily form imidazole chloramines that can rapidly chlorinate other targets, it was hypothesized that similar reactions may occur with histamine and carnosine, leading to propagation, rather than prevention, of HOCl-mediated damage. In this study, the reactions of HOCl with histamine, histidine, carnosine, and other compounds containing imidazole and free amine sites were examined. In all cases, rapid formation (k, 1.6 x 10(5) M(-)(1) s(-)(1)) of imidazole chloramines was observed, followed by chlorine transfer to yield more stable, primary chloramines (R-NHCl). The rates of most of these secondary reactions are dependent upon substrate concentrations, consistent with intermolecular mechanisms (k, 10(3)-10(4) M(-)(1) s(-)(1)). However, for carnosine, the imidazole chloramine transfer rates are independent of the concentration, indicative of intramolecular processes (k, 0.6 s(-)(1)). High-performance liquid chromatography studies show that in all cases the resultant R-NHCl species can slowly chlorinate N-alpha-acetyl-Tyr. Thus, the current data indicate that the chloramines formed on the imidazole and free amine groups of these compounds can oxidize other target molecules but with limited efficiency, suggesting that histamine and particularly carnosine may be able to limit HOCl-mediated oxidation in vivo. PMID:16800640

  5. Mechanistic chemistry of oxidation of balsalazide with acidic chloramine-T and bromamine-T: A comparative spectrophotometric kinetic study

    Indian Academy of Sciences (India)

    Puttaswamy; S Dakshayani

    2014-11-01

    Balsalazide (BSZ) belongs to a class of non-steroidal anti-inflammatory drugs. Kinetics and mechanism of oxidation of BSZ with sodium N-halo-p-toluenesulfonamides viz., chloramine-T(CAT) and bromamine-T(BAT) in HClO4 medium have been spectrophotometrically investigated (max =357nm) at 303 K. Under comparable experimental conditions, reactions with both the oxidants follow a first-order dependence of rate on [BSZ] and fractional-order dependence on each [oxidant] and [HClO4]. Activation parameters and reaction constants have been computed. 2-hydroxy-5-nitroso-benzoic acid and 3-(4-nitroso-benzoylamino)-propionic acid are identified as the oxidation products of BSZ with both CAT and BAT. The rate of oxidation of BSZ is about five-fold faster with BAT than with CAT. Plausible mechanism and related rate law have been deduced for the observed kinetics.

  6. N-nitrosodimethylamine (NDMA) formation potential of amine-based water treatment polymers: Effects of in situ chloramination, breakpoint chlorination, and pre-oxidation.

    Science.gov (United States)

    Park, Sang Hyuck; Padhye, Lokesh P; Wang, Pei; Cho, Min; Kim, Jae-Hong; Huang, Ching-Hua

    2015-01-23

    Recent studies show that cationic amine-based water treatment polymers may be important precursors that contribute to formation of the probable human carcinogen N-nitrosodimethylamine (NDMA) during water treatment and disinfection. To better understand how water treatment parameters affect NDMA formation from the polymers, the effects of in situ chloramination, breakpoint chlorination, and pre-oxidation on the NDMA formation from the polymers were investigated. NDMA formation potential (NDMA-FP) as well as dimethylamine (DMA) residual concentration were measured from poly(epichlorohydrin dimethylamine) (polyamine) and poly(diallyldimethylammonium chloride) (polyDADMAC) solutions upon reactions with oxidants including free chlorine, chlorine dioxide, ozone, and monochloramine under different treatment conditions. The results supported that dichloramine (NHCl2) formation was the critical factor affecting NDMA formation from the polymers during in situ chloramination. The highest NDMA formation from the polymers occurred near the breakpoint of chlorination. Polymer chain breakdown and transformation of the released DMA and other intermediates were important factors affecting NDMA formation from the polymers in pre-oxidation followed by post-chloramination. Pre-oxidation generally reduced NDMA-FP of the polymers; however, the treatments involving pre-ozonation increased polyDADMAC's NDMA-FP and DMA release. The strategies for reducing NDMA formation from the polymers may include the avoidance of the conditions favorable to NHCl2 formation and the avoidance of polymer exposure to strong oxidants such as ozone. PMID:25112551

  7. Precursors and factors affecting formation of haloacetonitriles and chloropicrin during chlor(am)ination of nitrogenous organic compounds in drinking water.

    Science.gov (United States)

    Jia, Aiyin; Wu, Chunde; Duan, Yan

    2016-05-01

    This study investigated the precursors and factors affecting formation of haloacetonitriles (HANs) and chloropicrin (TCNM) during chlorination/chloramination of eight amino acids in the effluent water of V-type clarifying filtration from a drinking water treatment plant. The yields of trichloroacetonitrile (TCAN), dichloroacetonitrile (DCAN) and TCNM were higher during chlorination than during chloramination. Tyrosine and tryptophan produced the greatest amount of DCAN and also generated a small amount of TCAN during chlorination process. Besides, the yields of DCAN were higher than TCNM during chlorination/chloramination. Contact time, Cl2:org-N molar ratios, pH, temperature and bromide ion affected nitrogenous disinfection by-products (N-DBPs) formation during chlorination of tryptophan in different degrees. TCAN, DCAN and TCNM formation showed the increasing and then decreasing with prolonged contact time. Higher Cl2:org-N molar ratios improved N-DBPs formation within a certain range. The pH affected N-DBPs formation differently. HANs increased with increasing pH from 5 to 6 and decreased with increasing pH from 6 to 9, while TCNM increased with increasing pH from 5 to 9. Higher temperatures enhanced TCNM formation, but reduced the formation of TCAN and DCAN. The presence of bromide ions improved the yields of HANs and TCNM and shifted N-DBPs to more brominated ones. PMID:26859617

  8. OXIDATION OF PROPRANOLOL USING CHLORAMINE – T IN HClO4 MEDIUM: A KINETIC AND MECHANISTIC STUDY

    Directory of Open Access Journals (Sweden)

    Range Gowda Ramachandrappa

    2012-06-01

    Full Text Available Kinetics and oxidation of Propranolol (PPL ((RS-1-(1-methylethylamino-3-(1-naphthyloxypropan-2-ol by sodium – N- chloro – p- toluenesulphonamide (Chloramine – T or CAT in HClO4 medium at 298K have been studied. The rate was first order in [CAT]o, fractional order in [PPL] and zero order in [H+]. Addition of p-toluenesulphonamide, NaCl and NaBr did not affect the rate of the reaction. Variation in ionic strength did not affect the rate of the reaction indicating that non – ionic species are involved in the rate limiting step. The dielectric effect of the medium was positive. Rate increased with increase in temperature from 288K to 318K. From the linear Arrhenius plot, activation parameters were computed. Addition of reaction mixture to aqueous acrylonitrile solution did not initiate polymerization, showing the absence of free radicals species. Oxidation products were identified. TsNClNa, the reactive species, oxidizes the substrate. Based on kinetic results, reaction stoichiometry and oxidation products, a suitable mechanism have been proposed.

  9. Formation of halogenated C-, N-DBPs from chlor(am)ination and UV irradiation of tyrosine in drinking water

    International Nuclear Information System (INIS)

    The formation of regulated and emerging halogenated carbonaceous (C-) and nitrogenous disinfection by-products (N-DBPs) from the chlor(am)ination and UV irradiation of tyrosine (Tyr) was investigated. Increased chlorine contact time and/or Cl2/Tyr ratio increased the formation of most C-DBPs, with the exception of 4-chlorophenol, dichloroacetonitrile, and dichloroacetamideChloroform and dichloroacetic acid increased with increasing pH, dichloroacetonitrile first increased and then decreased, and other DBPs had maximum yields at pH 7 or 8. The addition of ammonia significantly reduced the formation of most C-DBPs but increased 4-chlorophenol, dichloroacetonitrile, dichloroacetamide, and trichloroacetonitrile yields for short prechlorination contact times before dosing ammonia. When UV irradiation and chlorination were performed simultaneously, the concentrations of the relatively stable C-DBPs increased, and the concentrations of dichloroacetonitrile, dichloroacetamide, and 4-chlorophenol decreased with increasing UV dose. This information was used to develop a mechanistic model for the formation of intermediate DBPs and end products from the interaction of disinfectants with tyrosine. Highlights: ► Increased contact time and/or Cl2/Tyr decreased the formation of some N-DBPs. ► Changing the pH of disinfection decreases the formation of some N-DBPs. ► N-DBP yields increased for short prechlorination contact time before dosing ammonia. ► Low pressure UV before chlorination did not impact the formation of DBPs from Tyr. ► A novel integrated formation pathway of halogenated C-, N-DBPs is proposed. - Exploring the integrated formation mechanism of regulated and emerging highly toxic DBPs, which is expected to preferably reduce their occurrence in drinking water.

  10. Influence of chloramine T iodination on the biological and immunological activity or the molecular radius of the human growth hormone molecule

    International Nuclear Information System (INIS)

    Potential alterations of the somatotropic activity of human growth hormone (hGH) resulting from Chloramine T labelling reaction, iodination up to 2.7 atoms/molecule and indirect radiation effects, have been studied. Three 2X2 factorial assays, performed in hypophysectomized rats, failed to reveal any significant difference (P greater than 0.05) in true growth promoting activity between hGH and (127-I)hGH, even after storing the latter with 125-I. Similar results were obtained applying a sensitive and precise gel filtration technique for Stokes Radius determination and radioimmunoassay

  11. Identification, toxicity and control of iodinated disinfection byproducts in cooking with simulated chlor(am)inated tap water and iodized table salt.

    Science.gov (United States)

    Pan, Yang; Zhang, Xiangru; Li, Yu

    2016-01-01

    Chlorine/chloramine residuals are maintained in drinking water distribution systems to prevent microbial contamination and microorganism regrowth. During household cooking processes (e.g., soup making), the residual chlorine/chloramines in tap water may react with the iodide in iodized table salt to form hypoiodous acid, which could react with remaining natural organic matter in tap water and organic matter in food to generate iodinated disinfection byproducts (I-DBPs). However, I-DBPs formed during cooking with chloraminated/chlorinated tap water are almost completely new to researchers. In this work, by adopting precursor ion scan of m/z 127 using ultra performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry, many new polar I-DBPs formed during cooking with chloraminated/chlorinated tap water were detected and proposed with structures, of which 3-iodo-4-hydroxybenzaldehyde, 3-iodo-4-hydroxybenzoic acid, 3-iodo-4-hydroxy-5-methylbenzoic acid, diiodoacetic acid, 3,5-diiodo-4-hydroxybenzaldehyde, 3,5-diiodo-4-hydroxybenzoic acid, 2,6-diiodo-4-nitrophenol, 2,4-diiodo-6-nitrophenol, and 2,4,6-triiodophenol were confirmed with standard compounds. With the aid of ultra fast liquid chromatography/ion trap-time of flight-mass spectrometry, molecular formula identification of five new I-DBPs (C8H5O4I, C7H4NO4I, C8H5O5I, C7H4NO5I, and C8H6O3I2) was achieved. A developmental toxicity with a recently developed sensitive bioassay was conducted for the newly identified I-DBPs, suggesting that phenolic I-DBPs (except for iodinated carboxyphenols) were about 50-200 times more developmentally toxic than aliphatic I-DBPs. The major I-DBPs in a baseline simulated cooking water sample were determined to be from 0.72 to 7.63 μg/L. Polar I-DBPs formed under various disinfection and cooking conditions were compared, and suggestions for controlling their formation were provided. PMID:26474150

  12. Effects of sub lethal concentration of Chloramin T on growth, survival, haematocrit and some blood biochemical parameters in common carp fry (Cyprinus carpio

    Directory of Open Access Journals (Sweden)

    Mohamad R. Imanpoor

    2011-07-01

    Full Text Available This study was done in Gorgan University of Agricultural Sciences and Natural Resources, in 2009, during 8 weeks to survey effects of different concentrations of Chloramin T on fry common carp (Cyprinus carpio (Linnaeus, 1758. According to the pre experiment data, lethal concentration, the lowest observed effect concentration, maximum allowable toxicant concentration and No Observed Effect Concentration of Chloramin T (Halamid in common carp (C. carpio fry were respectively 40.9, 27.1, 4.90 and 11.28 mg/L-1. Hence, the range of our experiment was between 0 to 25 mg L-1 which was divided to five treatments (0, 5, 10, 15 and 25 mg/L-1. At the end of experiment we calculated growth factor (special growth rate and food conversion ratio and stress indices (glucose total protein and percent of haematocrit and then they were compared with the controlled group. Our study results showed no significant difference between percentage of increase in body weight (280.4±25.79 - 200.4±10.16, special growth rate (2.34±0.25 - 1.96±0.06 and food conversion ratio (0.84±0.05 - 0.60±0.12 in experimental lots of fishes. There is also no significant difference between glucose (146.82±0.79 - 99.54±1.89 and total protein (3.61±0.45 - 2.82±0.06 in experimental groups (P>.05. However there is a significant difference between the percentages of haematocrit (57.34±4.99 - 40.74±2.17 and cholesterol (362.05±24.38 - 134.92±17.59 in these groups (P<0.05.

  13. Fluorous Analogue of Chloramine-T: Preparation, X-ray Structure Determination, and Use as an Oxidant for Radioiodination and s-Tetrazine Synthesis.

    Science.gov (United States)

    Dzandzi, James P K; Beckford Vera, Denis R; Genady, Afaf R; Albu, Silvia A; Eltringham-Smith, Louise J; Capretta, Alfredo; Sheffield, William P; Valliant, John F

    2015-07-17

    A fluorous oxidant that can be used to introduce radioiodine into small molecules and proteins and generate iodinated tetrazines for bioorthogonal chemistry has been developed. The oxidant was prepared in 87% overall yield by combining a fluorous amine with tosyl chloride, followed by chlorination using aqueous sodium hypochlorite. A crystal structure of the oxidant, which is a fluorous analogue of chloramine-T, was obtained. The compound was shown to be stable for 7 days in EtOH and for longer than three months as a solid. The oxidant was effective at promoting the labeling of arylstannanes using [(125)I]NaI, where products were isolated in high specific activity in yields ranging from 46% to 86%. Similarly, iodinated biologically active proteins (e.g., thrombin) were successfully produced, as well as a radioiodinated tetrazine, through a concomitant oxidation-halodemetalation reaction. Because of its fluorous nature, unreacted oxidant and associated reaction byproducts can be removed quantitatively from reaction mixtures by passing solutions through fluorous solid phase extraction cartridges. This feature enables rapid and facile purification, which is critical when working with radionuclides and is similarly beneficial for general synthetic applications. PMID:26030355

  14. Critical evaluation of the radioiodination of follicle-stimulating-and luteinizing hormones by lactoperoxidase and its comparison with chloramine-T classical method

    International Nuclear Information System (INIS)

    A method is described for the enzymatic radioiodination of human gonadotropins by a system consisting of lactoperoxidase, hydrogen peroxide and Na125I. A comparison witth the clhloramine-T modified technique was done a satisfactory specific activity (100 μCi/μg) of the labeled hormone was obtained with the enzymatic iodination, with much greater immunoreactivity and stability than after chloramine-T. As aqueous polyethylene glycol causes precipitation of antibody-bound peptide hormones with radioactive iodine with little or no precipitation of free hormones, a method of separation was developed and applied to radioimmunoassay of gonadotropins, providing several advantages over te double-antibody precipitation method. It was demonstrated that, in humans, the intravenous administration of synthetic LH-FSH/RH, stimulates the pituitary release of both LH and FSH. Results are reported now for normal women, infused with an acute load of 25μg of synthetic LH/FSH-RH and 8 hours infusion of 100μg, during the mid-follicular and luteal phases. The greatest gonadotropin responsiveness to LH/FSH-RH are found in the luteal phase during acute testing. No differences were noticed during chronic infusion as well as acute post-chronic, performed in both phases of the menstrual cycle. The possible modulating effects of steroidal secretion by the ovaries are discussed. (Author)

  15. Surto de reações hemolíticas associado a residuais de cloro e cloraminas na água de hemodiálise Outbreak of hemolytic reactions associated with chlorine and chloramine residuals in hemodialysis water

    Directory of Open Access Journals (Sweden)

    Rachel VV Calderaro

    2001-10-01

    Full Text Available OBJETIVO: Relatar o processo de investigação da contaminação da água e a conseqüente avaliação do surto ocorrido no serviço de hemodiálise. MÉTODOS: Em setembro de 2000, 16 pacientes sob terapia de hemodiálise de um hospital em Minas Gerais apresentaram reações hemolíticas compatíveis a sintomas de intoxicação por cloro e cloramina em água. Foi feita a medição das concentrações de cloro e cloramina em amostras coletadas em diversos pontos do sistema de tratamento e distribuição de água do serviço inspecionado. A identificação dos casos ocorridos durante o período de estudo foi feita pela revisão das anotações de prontuários dos pacientes. Foi feita a revisão dos procedimentos da equipe técnica, médica e de enfermagem por meio de entrevistas. RESULTADOS: A taxa de sintomas foi significativamente alta (pOBJECTIVE: To investigate the process of water contamination and to assess the subsequent outbreak in the hemodialysis center. METHODS: In September 2000, sixteen patients undergoing chronic hemodialysis at a dialysis center in Minas Gerais, Brazil, experienced hemolytic reactions compatible with toxic symptoms due to chlorine and chloramine water contamination. Chlorine and chloramine concentrations in samples obtained from various sites of the dialysis center's water treatment and distribution system were measured. Case-patients were identified by reviewing medical records and nursing notes for all dialysis sessions carried out during the study period. Interviews with technicians, nursing and medical staff members were conducted. RESULTS: Reaction rate was significantly higher (p£0.5 mg/L for chlorine and £ 0.1 mg/L for chloramine. Individuals exposed to high chlorine and chloramine concentrations presented a relative risk of 2.58 (1.0-6.28 of having hemolytic reactions. CONCLUSION: There is a need to observe surveillance procedures to secure that the maximum allowable concentrations of regulated substances

  16. Influence of Natural Organic Matter (NOM) Character on the Distribution of Chlorinated and Chloraminated Disinfection By-Products (DBPs) at Rand Water

    Science.gov (United States)

    Marais, Savia S.; Ncube, Esper J.; Haarhoff, Johannes; Msagati, Titus AM; Mamba, Bhekie B.; Nkambule, Thabo I.

    2016-04-01

    Certain disinfection by-products (DBPs) are likely human carcinogens or present mutagenic effects while many DBPs are unidentified. Considering the possibility of DBPs being harmful to human health and the fact that trihalomethanes (THMs) are the only regulated DBP in the South African National Standard (SANS:241) for drinking water, special interest in the precursors to these DBPs' formation is created. It is essential to understand the reactivity and character of the precursors responsible for the formation of DBPs in order to enhance precursor removal strategies during the treatment of drinking water. In this study the character of NOM within surface water and the subsequent distribution of THMs formed in the drinking water from Rand Waters' full scale treatment plant were investigated. Molecular size distribution (MSD) of NOM within the surface water was determined by high performance size exclusion chromatography (HPSEC). Specific ultraviolet absorbance (SUVA) and UV254 measurements formed part of the NOM character study as they provide an indication of the aromaticity of organic matter. The four THMs; bromoform, chloroform, dibromochloromethane (DBCM) and bromodichloromethane (BDCM)were measured by gas chromatography. The sum of these four THMs was expressed as total trihalomethane (TTHM). On average the chloroform constituted 76.2% of the total TTHM, BDCM 22.5% while DBCM and bromoform measured below the detection limit. THM speciation after chlorination and chloramination concentrations increased in the sequence bromoform < DBCM < BDCM < chloroform. Results of the MSD showed a significant correlation between NOM of high molecular size (peak I) and TTHM formation specifically during the summer months (R2= 0.971, p < 0.05). High molecular weight (HMW) NOM also related well to chloroform formation (R2 = 0.963, p < 0.05) however, the formation of BDCM was not due to HWM fraction as indicated by weak regression coefficient. A positive correlation existed between

  17. Effect of Chloramine Auxiliary Disinfection and Organic Halide Content Change in Drinking Water%饮用水氯胺辅助消毒的效果及有机卤化物含量变化

    Institute of Scientific and Technical Information of China (English)

    李为兵; 陈雪芳; 袁哲; 陈卫

    2011-01-01

    Compared with chlorine disinfection, chloramine disinfection can effectively reduce the formation of disinfection byproducts.After chlorination in clear water tank, chloramine is used as auxiliary disinfectant to maintain the water quality in water distribution network in Kunshan City.The qualified rate of water quality at monitoring points rises from 92.8% to 99.5%, and the disinfection effect in water distribution network is distinctly improved.When the organic content is high, using chloramine auxiliary disinfection can reduce adsorbable organic halogens in drinking water by 48% comparing with the chlorine disinfection.Under the premise of ensuring the disinfection effect of treated water and water in clear water tank, the chlorine dosage in clear water tank should be reduced as far as possible to control the chlorine disinfection byproduct at a low level.Through the analysis of content of disinfection byproducts,such as trihalomethanes, chlorobenzene and haloacetic acids, it is confirmed that the chloramine disinfection may largely reduce the organic halide content in drinking water, which is consistent with the determination result of adsorbable organic halogen compounds.%与氯消毒相比,氯胺消毒能有效降低消毒副产物的生成量.昆山市在水厂清水池加氯消毒后,将氯胺用作维持管网水质的辅助消毒剂,使管网水质监测点的消毒剂余量和细菌总数合格率从92.8%上升到99.5%,管网消毒效果得到明显改善.在有机物含量较高的情况下,与氯消毒相比,采用氯胺辅助消毒可降低饮用水中可吸附有机卤素(AOX)含量达48%,因而在保证清水池和出厂水消毒效果的前提下,应尽量降低清水池的投氯量,以使氯消毒副产物含量控制在较低水平.通过对三卤甲烷、氯苯和卤乙酸等氯化消毒副产物含量的测定分析,证实氯胺消毒可大幅降低饮用水中的有机卤化物含量,这与对可吸附有机卤素的测定结果是一致的.

  18. Use of chloramine-T and two dyes in the sensitive determination of stavudine in pharmaceuticals Uso de cloramina-T e de dois corantes na determinação sensível de estavudina em medicamentos

    Directory of Open Access Journals (Sweden)

    Kanakapura Basavaiah

    2007-09-01

    Full Text Available Three new methods are described for the assay of stavudine (STV in bulk drug and in dosage forms using chloramine-T (CAT and two dyes, methyl orange and indigocarmine, as reagents. Titrimetry involves treating STV with a measured excess of CAT in hydrochloric acid medium, and after the oxidation of STV is judged to be complete, the unreacted oxidant is determined iodometrically. Spectrophotometric methods entail the addition of a known excess of CAT to STV in hydrochloric acid medium followed by determination of residual oxidant by reacting with a fixed amount of either methyl orange and measuring the absorbance at 520 nm (Method A or indigo carmine and measuring the absorbance at 610 nm (Method B. In all the methods, the amount of CAT reacted corresponds to the amount of STV. In titrimetric method, the reaction follows 1:1 stoichiometry (STV: CAT, and is applicable over the range 1.5-10 mg of STV. In spectrophotometric methods, the absorbance is found to increase linearly with concentration of STV. The systems obey Beer's law for 0.2-2.0 and 1.0-10.0 mg/mL for method A and method B, respectively. The apparent molar absorptivities are calculated to be 5.7x10(4 and 1.5x10(4 L/mol/cm for method A and method B, respectively, and the corresponding Sandell sensitivity values are 0.004 and 0.015 µg/cm². The limits of detection and quantification are reported for both methods. Intra-day and inter-day precision and accuracy of the developed methods were evaluated as per the current ICH guidelines. The methods were successfully applied to the assay of STV in tablet and capsule formulations and the results were compared with those of a reference method by applying Student's t-test and F-test. No interference was observed from common tablet adjuvants. The accuracy and reliability of the methods were further ascertained by performing recovery experiments via standard-addition method.Descrevem-se três novos métodos para o ensaio de estavudina (STV na mat

  19. Chlorine, Chloramine, Chlorine Dioxide, and Ozone Susceptibility of Mycobacterium avium

    OpenAIRE

    Taylor, Robert H.; Joseph O. Falkinham; Norton, Cheryl D.; LeChevallier, Mark W.

    2000-01-01

    Environmental and patient isolates of Mycobacterium avium were resistant to chlorine, monochloramine, chlorine dioxide, and ozone. For chlorine, the product of the disinfectant concentration (in parts per million) and the time (in minutes) to 99.9% inactivation for five M. avium strains ranged from 51 to 204. Chlorine susceptibility of cells was the same in washed cultures containing aggregates and in reduced aggregate fractions lacking aggregates. Cells of the more slowly growing strains wer...

  20. EFFECT OF CHLORAMINATION AND SEASONAL WATER CHANGES ON NANOFILTRATION FOULING

    Science.gov (United States)

    Nanofiltraton membrane studies conducted with Little Miami Aquifer water from the Indian Hill Water Works (OH) showed tht flux loss was highly seasonal in nature with the greatest fouling occurring during the highest water temperatures during drought conditions. The reason for th...

  1. Preparation of iodine - 125 - labeled insulin for radioimmunoassay: comparison of chloramine T and iodogen iodination

    International Nuclear Information System (INIS)

    Stoichiometric iodination of porcine insulin was performed to the general method of Hunter and Greenwood with modifications recommended by Roth. These method was compared with radioidination using Iodogen. Films of Iodogen react rapidly in the solid phase with aqueous mixtures of I -and proteins. For two methods satisfactory activity of the labeled porcine insulin was obtained and characteristics of the radioimmunoassay were studied. (author)

  2. Biofilm Community Dynamics in Bench-Scale Annular Reactors Simulating Arrestment of Chloraminated Drinking Water Nitrification

    Science.gov (United States)

    Annular reactors (ARs) were used to study biofilm community succession and provide an ecological insight during nitrification arrestment through simultaneously increasing monochloramine (NH2Cl) and chlorine to nitrogen mass ratios, resulting in four operational periods (I to IV)....

  3. The effect of taurine chloramine on human osteosarcoma cell-lines

    International Nuclear Information System (INIS)

    Osteosarcoma is the most frequent nonhaematogenic primary malignant tumor of the bone. The rather rare tumour occurs mainly in children and adolescents. This osteogenic tumour is a high-aggressive mesenchymal neoplasm typically producing osteoid. The surgical resection of the complete tumour must be carried out with wide or radical margins to prevent recurrence. Even though the combination of surgery with chemotherapy has noticeably improved the survival rate of osteosarcoma patients, the application of anticancer drugs is still associated with significant adverse reactions, for example the common acquisition of drug-resistant phenotypes, indicating the need of new chemotherapeutical substances. Taurine is a sulfur-containing β-amino acid, which is present in high concentrations in mammalian cells and plasma, in granulocytes and lymphocytes. Large quantities of taurine are released by stimulated neutrophiles and rapidly chlorinated by the reaction with hypochlorous acid (HOCl) generating taurine monochloramine (NCT). NCT is noted to play quite a few roles in the modulation of the immune response and sizeably decreases the production of plenty proinflammatory mediators from adherent as well as non-adherent leucocytes. NCT inhibits the intracellular transcription of nitric-oxide synthase and the production of nitric oxide and switches cell death from the less advantageous necrosis to the more physiologically beneficial apoptosis. Aim of this study was to research, if different concentrations of NCT are capable to induce apoptosis in the human osteosarcoma cell lines HOS, MG-63 and SAOS-2. Therefore the cell proliferation assay EZ4U, a fluorescence staining with acridine-orange, an ELISA for the detection of DNA-fragments and a JC-1 mitochondrial FACS-analysis were performed. The results of these four independent experiments show, that NCT has a pro-apoptotic effect on these osteosarcoma cell lines. (author)

  4. Changes in physicochemical and transport properties of a reverse osmosis membrane exposed to chloraminated seawater

    KAUST Repository

    Valentino, Lauren

    2015-02-17

    This study contributed to improving our understanding of how disinfectants, applied to control biofouling of reverse osmosis (RO) membranes, result in membrane performance degradation. We investigated changes in physicochemical properties and permeation performance of a RO membrane with fully aromatic polyamide (PA) active layer. Membrane samples were exposed to varying concentrations of monochloramine, bromide, and iodide in both synthetic and natural seawater. Elemental analysis of the membrane active layer by Rutherford backscattering spectrometry (RBS) revealed the incorporation of bromine and iodine into the polyamide. The kinetics of polyamide bromination were first order with respect to the concentration of the secondary oxidizing agent Br2 for the conditions investigated. Halogenated membranes were characterized after treatment with a reducing agent and heavy ion probes to reveal the occurrence of irreversible ring halogenation and an increase in carboxylic groups, the latter produced as a result of amide bond cleavage. Finally, permeation experiments revealed increases in both water permeability and salt passage as a result of oxidative damage.

  5. KINETICS OF OXIDATION OF SALBUTAMOL BY CHLORAMINE-B IN NaOH MEDIUM: A MECHANISTIC APPROACH

    Directory of Open Access Journals (Sweden)

    Iyengar Pushpa

    2012-04-01

    Full Text Available The kinetics of oxidation of salbutamol (SBL by N-chlorobenzenesulphonamide (CAB in NaOH medium has been investigated at 303K. The reaction rate shows a first order dependence on [CAB]0 , fractional order with respect to [SBL]0 and a negative fractional order with respect to [OH-] . The addition of the reduction product, benzenesulphonamide , retards the reaction rate. The effect of dielectric constant of the medium by varying [MeOH] shows an inverse effect. The addition of chloride ions and variation of ionic strength of the medium have no significant effect on the rate of the reaction. The reaction fails to initiate polymerization of acrylamide. The oxidation products were identified. The Michaelis – Menten type of kinetics has been proposed. The reaction was studied at different temperatures and the values of thermodynamic parameters were computed. A mechanism consistent with the observed kinetics is proposed.

  6. Impact of Chloramination on the Development of Laboratory-Grown Biofilms Fed with Filter-Pretreated Groundwater

    OpenAIRE

    Ling, Fangqiong; Liu, Wen-Tso

    2012-01-01

    This study evaluated the continuous impact of monochloramine disinfection on laboratory-grown biofilms through the characterization of biofilm architecture and microbial community structure. Biofilm development and disinfection were achieved using CDC (Centers for Disease Control and Prevention) biofilm reactor systems with polyvinyl chloride (PVC) coupons as the substratum and sand filter-pretreated groundwater as the source of microbial seeding and growth nutrient. After 2 weeks of growth, ...

  7. SENSITIVITY OF THREE ENCEPHALITOZOON SPECIES TO CHLORINE AND CHLORAMINE TREATMENT AS DETECTED BY AN IN-VITRO MICROWELL PLATE ASSAY (POSTER PRESENTATION)

    Science.gov (United States)

    Microsporidia are obligate intracellular parasites that form environmentally resistant, infectious spores. These parasites are ubiquitous in the environment, infecting members of almost every class of verebrates and invertebrates. At least 14 microsporidian species that infect th...

  8. LJFO00000000, LJFQ00000000, LJFT00000000, LJFU00000000, LJFX00000000, LJFY00000000

    Data.gov (United States)

    U.S. Environmental Protection Agency — Draft genome sequences of six Mycobacterium immunogenum strains isolated from a chloraminated drinking water distribution system simulator subjected to changes in...

  9. Preparation of high-quality iodine-125-labelled pituitary human follicle-stimulating hormone (hFSH) for radioimmunoassay

    International Nuclear Information System (INIS)

    A method is described for the enzymatic radioiodination of human follice-stimulating hormone (hFSH) by a system consisting of lactoperoxidase, hydrogen peroxide and Na125I. It is compared with the chloramine-T modified technique. A satisfactory specific activity of the labelled hormone is obtained with the enzymatic iodination, with much greater immunoreactivity and stability than with chloramine-T

  10. Formation of trichloronitromethane and dichloroacetonitrile in natural waters: Precursor characterization, kinetics and interpretation

    Energy Technology Data Exchange (ETDEWEB)

    Chuang, Yi-Hsueh; Tung, Hsin-hsin, E-mail: htung@ntu.edu.tw

    2015-02-11

    Graphical abstract: - Highlights: • Aromatic NOM is the important precursor for TCNM and DCAN in chloramination. • TCNM and DCAN originated from DON followed 2nd order reaction kinetics. • TCNM and DCAN formation was faster when precursors were originated from DON than from chloramine. • DCAN formation kinetics equations were confirmed by tyrosine {sup 15}N-chloramination study. • 4-Hydroxybenzaldehyde is an important DCAN precursor during chloramination of natural water. - Abstract: During the chloramination of natural waters, both chloramines and dissolved organic nitrogen (DON) can serve as nitrogen sources for the formation of trichloronitromethane (TCNM) and dichloroacetonitrile (DCAN). The present study investigated the formation kinetics and precursor characteristics of TCNM and DCAN. {sup 15}N-Isotopic monochloramination of the organic fractions produced both {sup 15}N- and {sup 14}N-DCAN and TCNM. Nitrogenous disinfection byproduct (N-DBP) formation, in which the nitrogen precursor originated from DON ({sup 14}N-DCAN and {sup 14}N-TCNM), followed a second-order reaction kinetics (k = 3.2 × 10{sup −5} to 9.4 × 10{sup −5} μM{sup −1} h{sup −1}). The formation of N-DBP where the nitrogen atoms originated from chloramines (e.g. {sup 15}N-DCAN and {sup 15}N-TCNM) correlated linearly with chloramine exposure. The discrepancy in formation kinetics results in that the {sup 14}N-DCAN concentrations were two to ten times higher than {sup 15}N-DCAN in the beginning of the reaction (<12 h). Possible rate equations are proposed in this study. The results of a model compound study support the results of the chloramination of natural waters. In addition, 4-hydroxybenzaldehyde, an oxidative product commonly found during chlorination/chloramination of natural organic matters, gave a 10-fold greater yield of DCAN than that produced from tyrosine; 4-hydroxybenzaldehyde is thus an important precursor in DCAN formation by chloramine incorporation during the

  11. 氯胺消毒对饮用水消毒副产物形成和致突变性的影响%Effect of Chloramine Disinfection on the Formation of Drinking Water Disinfection By-Products and Their Mutagenicity

    Institute of Scientific and Technical Information of China (English)

    衡正昌; 李朝晖; 姜维华; 谢海英

    2003-01-01

    目的评价氯胺消毒对饮用水消毒副产物形成和致突变性的影响.方法分别于2001年8月(丰水期)和2002年3月(枯水期)对成都市某水厂氯胺消毒和液氯消毒饮用水的细菌学指标以及氯仿、四氯化碳含量进行了检测,对其水样的有机浓集物进行了Ames试验,然后比较两种消毒饮用水的消毒副产物含量和致突变性.结果用氯胺消毒的饮用水中余氯量约1 mg/L时均未检出细菌总数和大肠菌群,且氯仿含量较用液氯消毒减少了81%~84%,两种消毒方式的饮水中四氯化碳含量均小于0.2μg/L.对于TA98菌株,液氯消毒的出厂水1.5 L检出阳性反应,而氯胺消毒检出阳性反应的水样量≥6.0 L.结论采用氯胺消毒可以明显降低饮用水氯化副产物的含量和致突变性,其消毒效果不亚于氯化消毒,因此,氯胺是较好的替代消毒剂.

  12. Hypochlorite-induced damage to nucleosides

    DEFF Research Database (Denmark)

    Hawkins, C L; Davies, Michael Jonathan

    2001-01-01

    Stimulated monocytes and neutrophils generate hypochlorite (HOCl) via the release of the enzyme myeloperoxidase and hydrogen peroxide. HOCl is a key bactericidal agent, but can also damage host tissue. As there is a strong link between chronic inflammation and some cancers, we have investigated...... the propensity for radical formation is cytidine > adenosine = guanosine > uridine = thymidine. These data are inconsistent with the selectivity of HOCl attack and the stability of the resulting chloramines, but can be rationalized if chlorine transfer between bases is rapid and yields the most stable...... chloramine, with such transfer preceding radical formation. Thus, though thymidine is the major initial site of chloramine formation, rapid chlorine atom transfer generates cytidine and adenosine chloramines. These reactions rationalize the preferential formation of chlorinated cytidine and adenosine in DNA....

  13. TOXICITY OF RESIDUAL CHLORINE COMPOUNDS TO AQUATIC ORGANISMS

    Science.gov (United States)

    Laboratory studies on the acute and chronic toxicity of chlorine and inorganic chloramines to trout, salmon, minnows, bullhead, largemouth bass, and bluegill were conducted. Acute toxicity under continuous and intermittent patterns of exposure as well as behavioral, reproduction,...

  14. MONITORING FOR AEROMONAS SPECIES AFTER TREATMENT WITH COMMON DRINKING WATER DISINFECTANTS

    Science.gov (United States)

    The sensitivity of Aeromonas spp. To free chlorine, chloramine and ultraviolet (UV) disinfection was determined. Aeromonas hydrophila is a contaminant listed on the USEPA's 1998 Contaminant Candidate List (CCL). Experiments using free chlorine indicated that the Aeromonas spp. ...

  15. Draft Genome of Two Sphingopyxis sp. Strains, Dominant Members of the Bacterial Community Associated with a Drinking Water Distribution System Simulator

    Science.gov (United States)

    We report the draft genome of two Sphingopyxis spp. strains isolated from a chloraminated drinking water distribution system simulator. Both strains are ubiquitous residents and early colonizers of water distribution systems. Genomic annotation identified a class 1 integron (in...

  16. ALTERNATIVE DISINFECTANTS FOR DRINKING WATER TREATMENT

    Science.gov (United States)

    During a one-year study at Jefferson Parish, Louisiana the chemical, microbiological, and mutagenic effects of using the major drinking water disinfectants (chlorine, chlorine dioxide, chloramine, ozone) were evaluated. ests were performed on samples collected from various treatm...

  17. ALTERNATIVE DISINFECTION FOR DRINKING WATER TREATMENT

    Science.gov (United States)

    During a one-yr study at Jefferson Parish, La., the chemical, microbiological, and mutagenic effects os using the major drinkgin water disinfectants (chlorine, chlorine dioxide, chloramine, ozone) were evaluated. Tests were performed on samples collected from various treatment s...

  18. Variations of the pharmakocinetic in rabbits of the monoclonal antibody ior t1 produced by the radioiodonation with the chloramina T and iodogen methods

    International Nuclear Information System (INIS)

    The monoclonal antibody ior t1, an IgG2a was labeled with 125I, using the chloramine T and iodogen methods. Immunoreactivity against human lymphocites in vitro was affected in a significant way, mostly with chloramine T methods. In F1 male rabbits, the plasma radioactivity declined in apparently bioexponential manner in the administration of unlabeled ior t1, measured by an specific ELISA to murine IgG, and with the use of chloramine T. A monoexponential declined with the iodogen reagent was observed. We consider the possible of an unspecific binding in blood in the experiment with iodogen reagent. The t-tes student analysis show significant differences between the unlabeled protein and both methods of radioiodination, that differences must be have their origin in the high specific activity when labeled with chloramine T and in the probably of non-specific binding when we employs the iodogen reagents

  19. Carbon-Fiber Nitrite Microsensor for In Situ Biofilm Monitoring

    Science.gov (United States)

    During nitrification, nitrite is produced as an intermediate when ammonia is oxidized to nitrate. It is well established that nitrifying biofilm are involved in nitrification episodes in chloraminated drinking water distribution systems with nitrite accumulation occurring during ...

  20. Radioiodination of melagenine-II with I-125 (preliminary study)

    International Nuclear Information System (INIS)

    Radioiodination of Melagenine-II with I-125 farmacokinetic studies was made, using Chloramine-T method. Radiochemical purity and stability of the labelled product were determined by radiochromatography. The labelled Melagenine-II showed two radioactive fractions

  1. Draft Genome Sequence of Two Sphingopyxis sp. Strains, Dominant Members of the Bacterial Community Associated with a Drinking Water Distribution System Simulator

    Science.gov (United States)

    We report the draft genome of two Sphingopyxis spp. strains isolated from a chloraminated drinking water distribution system simulator. Both strains are ubiquitous residents and early colonizers of water distribution systems. Genomic annotation identified a class 1 integron (in...

  2. Changes to Campus Water

    OpenAIRE

    Owczarski, Mark

    2005-01-01

    Beginning June 27, 2005 the Blacksburg-Christiansburg-VPI Water Authority will change its method of disinfecting drinking water, from free chlorine to chloramination, a process in which ammonia is added to chlorinated water. Water supplied to customers at Virginia Tech, and the Towns of Blacksburg and Christiansburg, will be affected by this change, as well as some Montgomery County residents on public water systems that purchase water from the towns. Chloraminated water is perfectly safe for...

  3. Nitrification in premise plumbing and its effect on corrosion and water quality degradation

    OpenAIRE

    Zhang, Yan

    2008-01-01

    Nitrification is increasingly of concern in US potable water systems, due to changes from chlorine to chloramine as a secondary disinfectant in order to comply with new regulations for disinfectant by-products. The ammonia that is released from the chloramine decay supports nitrification. A comprehensive literature review systematically examined the complex inter-relationships between nitrification, materials corrosion and metals release. That analysis suggested that nitrification ...

  4. Radio-labeling of polyethylene glycol modification of recombinant human interleukin-6

    International Nuclear Information System (INIS)

    Iodine-125 was used as labeling nuclide, and the PEG-rhIL-6 was labeled by the common used chloramines-T and the two-phase chloramines-T, respectively. The labeled compound was purified by both methods of gel filtration and ultrafiltration respectively. The purity of the labeled PEG-rhIL-6 was determined by both trichloroacetic acid (TCA) and SDS-PAGE, and the biological activity was determined by MTT method. The results demonstrated that the labeling rate and specific radioactivity were 74.5% and 5.513 x 105 Bq/μg for PEG-rhIL-6 by the two-phase chloramines-T method, higher than that by the common used chloramines-T method, which was 62.3% and 4.610 x 105 Bq/μg respectively. The purity of labeled PEG-rhIL-6, purified by both gel filtration and ultrafiltration methods, was over 99% with TCA method. The labeled PEG-rhIL-6 by two-phase chloramines-T method showed two bands, which was identical to that of standard PEG-rhIL-6 though SDS-PAGE, but the labeled PEG-rhIL-6 by common used chloramines-T method had one more band compared with standard PEG-rhIL-6. When determined by MTT, it shown that the biological activity of PEG-rhIL-6 iodinated by common used chloramines-T method was lower than that by two-phase chloramines-T method. (authors)

  5. The effect of chemical anti-inhibitors on fibrinolytic enzymes and inhibitors

    DEFF Research Database (Denmark)

    Sidelmann, Johannes Jakobsen; Jespersen, J; Kluft, C;

    1997-01-01

    proteases. We studied the influence of chemical anti-inhibitors (chloramine T, flufenamate, sodium lauryl sulfate, and methylamine) on fibrinolytic serine proteases and fibrinolytic enzyme inhibitors using the physiological substrate fibrin as plasmin substrate. Low concentrations of chloramine T (0.01 mmol...... plasminogen activators (apparent recovery > 200%). Sodium lauryl sulfate eliminates the major fibrinolytic enzyme inhibitors, but increases the activity of plasmin (apparent recovery > 200%) and plasminogen activator, urokinase type (apparent recovery 130%). Methylamine affects only plasmin inhibition. We...

  6. FATE OF REVERSE OSMOSIS (RO) MEMBRANES DURING OXIDATION BY DISINFECTANTS USED IN WATER TREATMENT: IMPACT ON MEMBRANE STRUCTURE AND PERFORMANCES

    KAUST Repository

    Maugin, Thomas

    2013-12-01

    Providing pretreatment prior RO filtration is essential to avoid biofouling and subsequent loss of membrane performances. Chlorine is known to degrade polymeric membrane, improving or reducing membrane efficiency depending on oxidation conditions. This study aimed to assess the impact of alternative disinfectant, NH2Cl, as well as secondary oxidants formed during chloramination of seawater, e.g. HOBr, HOI, or used in water treatment e.g. ClO2, O3, on membrane structure and performances. Permeability, total and specific rejection (Cl-, SO4 2-, Br-, Boron), FTIR profile, elemental composition were analyzed. Results showed that each oxidant seems to react differently with the membrane. HOCl, HOBr, ClO2 and O3 improved membrane permeability but decreased rejection in different extent. In comparison, chloramines resulted in identical trends but oxidized membrane very slowly. On the contrary, iodine improved membrane rejection e.g. boron, but decreased permeability. Reaction conducted with chlorine, bromine, iodine and chloramines resulted in the incorporation of halogen in the membrane structure. All oxidant except iodine were able to break amide bonds of the membrane structure in our condition. In addition, chloramine seemed to react with membrane differently, involving a potential addition of nitrogen. Chloramination of seawater amplified membrane performances evolutions due to generation of bromochloramine. Moreover, chloramines reacted both with NOM and membrane during oxidation in natural seawater, leading to additional rejection drop.

  7. Effect of pipe material and low level disinfectants on biofilm development in a simulated drinking water distribution system

    Institute of Scientific and Technical Information of China (English)

    Ling-ling ZHOU; Yong-ji ZHANG; Gui-bai LI

    2009-01-01

    The efficiency of chlorine and chloramines disinfection on biofilm development in a simulated drinking water distribution system was investigated by using heterotrophic bacterial spread plate technique.The experiments were carried out with four annular reactors(ARs)with stainless steel(SS)or copper(Cu)material slides.The results showed that there were fewer bacteria attached to Cu slides without a disinfectant compared with those attached to SS slides.When the water was disinfected with chloramines,the heterotrophic plate counts(HPCs)on the biofilm attached to the Cu slides were significantly lower(by 3.46 log CFU/cm2)than those attached to the SS slides.Likewise,the biofilm HPC numbers on the Cu slides were slightly lower(by 1.19log CFU/cm2) than those on the SS slides disinfected with chlorine.In a quasi-steady state.the HPC levels on Cu slides can be reduced to 3.0 log CFU/cm2 with chlorine and to about 0.9 log CFU/cm2 with chloramines.The addition of chloramines resulted in a more efficient reduction of biofilm heterotrophic bacteria than did chlorine.We concluded that the chlorine and chloramines levels usually employed in water distribution system were not SUfficient to prevent the growth and development of microbial biofilm.The combination of copper pipe slides and chlorarnincs as the disinfectant was the most efficient combination to bring about diminished bacterial levels.

  8. Redox gradients in distribution systems influence water quality, corrosion, and microbial ecology.

    Science.gov (United States)

    Masters, Sheldon; Wang, Hong; Pruden, Amy; Edwards, Marc A

    2015-01-01

    Simulated distribution systems (SDSs) defined the interplay between disinfectant type (free chlorine and chloramines), water age (1-10.2 days), and pipe material (PVC, iron and cement surfaces) on water chemistry, redox zones and infrastructure degradation. Redox gradients developed as a function of water age and pipe material affected the quality of water consumers would receive. Free chlorine was most stable in the presence of PVC while chloramine was most stable in the presence of cement. At a 3.6 day water age the residual in the chlorinated PVC SDS was more than 3.5 times higher than in the chlorinated iron or cement systems. In contrast, the residual in the chloraminated cement SDS was more than 10 times greater than in the chloraminated iron or PVC systems. Near the point of entry to the SDSs where disinfectant residuals were present, free chlorine tended to cause as much as 4 times more iron corrosion when compared to chloramines. Facultative denitrifying bacteria were ubiquitous, and caused complete loss of nitrogen at distal points in systems with iron, and these bacteria co-occurred with very severe pitting attack (1.6-1.9 mm/year) at high water age. PMID:25462724

  9. Biological stability in drinking water: a regression analysis of influencing factors

    Institute of Scientific and Technical Information of China (English)

    LU Wei; ZHANG Xiao-jian

    2005-01-01

    Some parameters, such as assimilable organic carbon(AOC), chloramine residual, water temperature, and water residence time, were measured in drinking water from distribution systems in a northern city of China. The measurement results illustrate that when chloramine residual is more than 0.3 mg/L or AOC content is below 50 tμg/L, the biological stability of drinking water can be controlled.Both chloramine residual and AOC have a good relationship with Heterotrophic Plate Counts(HPC)(log value), the correlation coefficient was -0.64 and 0.33, respectively. By regression analysis of the survey data, a statistical equation is presented and it is concluded that disinfectant residual exerts the strongest influence on bacterial growth and AOC is a suitable index to assess the biological stability in the drinking water.

  10. Reactivity of selenium-containing compounds with myeloperoxidase-derived chlorinating oxidants

    DEFF Research Database (Denmark)

    Carroll, Luke; Pattison, David I.; Fu, Shanlin;

    2015-01-01

    and N-chloramines, causes damage to host tissue. Low molecular mass thiol compounds, including glutathione (GSH) and methionine (Met), have demonstrated efficacy in scavenging MPO-derived oxidants, which prevents oxidative damage in vitro and ex vivo. Selenium species typically have greater reactivity...... toward oxidants compared to the analogous sulfur compounds, and are known to be efficient scavengers of HOCl and other hypohalous acids produced by MPO. In this study, we examined the efficacy of a number of sulfur and selenium compounds to scavenge a range of biologically relevant N-chloramines and...... oxidants produced by both isolated MPO and activated neutrophils and characterized the resulting selenium-derived oxidation products in each case. A dose-dependent decrease in the concentration of each N-chloramine was observed on addition of the sulfur compounds (cysteine, methionine) and selenium...

  11. Differences in the pharmacokinetic and biodistribution in rates of the monoclonal antibody 125I-ior t1 due to I use of different methods of iodogen direct

    International Nuclear Information System (INIS)

    The monoclonal antibody ior t1, an IgG2a, was labeled with 125I, using the chloramine T, iodogen and iodine monochloride methods produce an important deiodination, demonstrated by ascending paper chromatography and the similarities between his serum profile respect to the radioactivity serum profile of the free 125I in Wistar rats. The plasma radioactivity declined in apparently bioexponential manner with the use of chloramine T and iodine monochloride, and show a monoexponential declined with the iodogen reagent. The pharmacokinetic of 125I ior t1, in the chloramine T methods, was very erractic. We consider the possible of an unspecific binding in blood in the experiment with iodogen reagents. The biodistribution show a similar pattern with other IgG2a in rats

  12. 125I radiolabelling of 1-34 N-terminal tetratiacontapeptide of bPTH with high specific activity and without destroying biological activity

    International Nuclear Information System (INIS)

    Radiolabelling of 1-34 N terminal synthetic biological active fragment of bovine parathormone (1-34 b PTH) with high specific activity and without loss of biological activity was studied. Chloramine T and lactoperoxydase methods were used. To assess biological activity of 125I 1-34 bPTH labelled fragment, their ability to activate renal cortical adenylate cyclase was used. The results show that enzymatic labelling method preserved the biological activity. With the chloramine T method it is possible to keep the biological activity by using DMSO

  13. Labelling of human follicle stimulant hormone with 125I, for radioimmunoassay

    International Nuclear Information System (INIS)

    An efficient labeling of human Follicle Stimulant Harmone is essential to development of sensitive radioimmunoassays. Iodination by Chloramine T method frequently is subject to severe iodination damage and some preparations are unaccetable for radioimmunoassays. Modifications to the Hunter method, changing incubation time, reaction temperature and reducing Chloramine T amount used in the reaction, were performed in obtaining a more effective labeling. FSH-125 I fraction obtained from Sephadex G-75 column purification presented excellent immunoreactivity and quality control of the steps of the reaction demonstrated a high percentage (90%) of intact Follicle Stimulant Hormone

  14. Comparison of the ribonucleoproteins of different rabies virus serotypes by radioimmunoassay

    International Nuclear Information System (INIS)

    Radioimmunoassay (RIA) provides a sensitive serological procedure for detecting rabies virus ribonucleoprotein (RNP) as well as its specific antibodies. RIA was carried out using highly purified RNPs labelled by the chloramine-T method. This paper describes optimal conditions for iodination of RNP with high specific activity. The optimal concentrations of 125I, RNP, chloramine-T, and reducing agent as well as the effect of pH on the reaction were investigated. RIA proved to be extremely sensitive for detection of homologous antibodies. In competition experiments the part-relationship of the group-specific RNPs of the three rabies virus serotypes (HEP, MOK and LBV) was confirmed

  15. Microelectrode investigation of the reactions between metallic pipe materials and monochloramine

    Science.gov (United States)

    Water quality parameters (i.e., pH, dissolved oxygen [DO], and phosphate) are known to impact metal reactivity with disinfectants and therefore corrosion and metals release into drinking water supplies. With various water utilities switching from free chlorine to chloramines for ...

  16. Superoxide radicals can act synergistically with hypochlorite to induce damage to proteins

    DEFF Research Database (Denmark)

    Hawkins, Clare L; Rees, Martin D; Davies, Michael Jonathan

    2002-01-01

    Activated phagocytes generate both superoxide radicals via a respiratory burst, and HOCl via the concurrent release of the haem enzyme myeloperoxidase. Amine and amide functions on proteins and carbohydrates are major targets for HOCl, generating chloramines (RNHCl) and chloramides (RC(O)NClR'), ...

  17. Using prechloramination to control trihalomethanes formation in River Huang water with high bromide

    Institute of Scientific and Technical Information of China (English)

    TAO Hui; CHEN Wei; LIN Tao; LIU Cheng; CHEN Jie; LI Gui-bai

    2008-01-01

    An effective technology in controlling trihalomethanes (THMs)formation in the case of large amounts of bromide presenting wag proposed,and the water of River Huang seriously polluted by bromide in winter in Tianjin City wag studied.The THMs formation characteristics during prechloramination using preformed chloramines and convened chloramines were studied through jar tests.Results show that,in prechloramination process,the formation of THMs by preformed chloramines is very few,while that by converted chloramines is a little higher.And the formation of THMs,especially Br-substituted THMs,increases with tIle increase of time and Cl2:N ratio as well as the decrease of pH.The result obtained in a pilot plant shows that compared with preehlorination,the prechlommination process can efficiendy control the formation of THMs,especially the Br-substituted species.With equal chlorine dosage.the prechloramination can maintain a hrser chlorine residue which offers a larger CT value than prechlorination.

  18. Preparation of 125I-protein A usable for up to 10 months in immunoassays

    DEFF Research Database (Denmark)

    Dyrberg, T; Billestrup, Nils

    1984-01-01

    Chloramine-T iodination of protein A from Staphylococcus aureus and gel electrophoretic purification of the iodination mixture results in a stable tracer of high specific and functional activity. Following repeated gel electrophoresis of the tracer only a single component was observed. The specif...

  19. OVERVIEW: DISINFECTION OF HELICOBACTER PYLORI AND AEROMONAS SPECIES

    Science.gov (United States)

    Helicobacter pylori and Aeromonas hydrophila are contaminants listed on the USEPA's 1998 Contaminant Candidate List (CCL).The sensitivity of H. pylori to chlorine and of Aeromonas spp. to inactivation by free chlorine, chloramine and ultraviolet (UV) was examined. Selective and...

  20. Improved radioimmunotherapy of hematologic malignancies. Progress report, November 1, 1993--October 31, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Press, O.W.

    1994-08-04

    This report summaries progress made during the time interval between November 1, 1993 and October 31, 1994 and briefly describes studies on the metabolism of antibodies targeting B cell antigens, retention of labeled antibodies by human B cell lymphocytes, and tissue distribution of Chloramine T and tyramine cellobiose labeled antibodies in mice harboring a human erythroleukemia tumor transplant.

  1. Comparison and evaluation of different methods for α-MSH labelling

    International Nuclear Information System (INIS)

    The authors have studied the behaviour of 125I-labelled α-MSH under different experimental conditions. Until now, the chloramine T method had been used by most investigators with variable results. They have tested three other labelling techniques based on 125I mild oxidation: (1) an enzymatic method with lactoperoxidase, (2) a sparingly soluble chloramine method (T.D.G.U.), and (3) modified chloramine T procedure, 'the iodine volatilization method'. Labelled hormone obtained after each kind of iodination was assayed for immunoreactivity. In addition, time course degradation was measured by classical RIA incubation procedures. Charcoal-dextran was used to separate bound and free antigen. The authors have found chloramine T-iodinated α-MSH to be significantly more damaged than preparations obtained by other methods and to be less stable when stored at -180C. No differences were found between the differently labelled 125I-labelled α-MSH fresh preparations in binding to surface receptors of human melanoma cell lines in culture. (Auth.)

  2. Synthesis of biologically active porcine secretin and [ITyr10] porcine secretin

    DEFF Research Database (Denmark)

    Kofod, Hans

    1991-01-01

    Porcine secretin, [Tyr10] secretin, and [Tyr13] secretin were synthesized by solid phase methodology and purified by stepwise gradient elution from a short reversed-phase column with ethanol and acetic acid as organic modifiers. [Tyr10] secretin and [Tyr13] secretin were iodinated by the chloramine...

  3. Treatment of trichodiniasis in eel ( Anguilla anguilla ) reared in recirculation systems in Denmark : alternatives to formaldehyde

    DEFF Research Database (Denmark)

    Madsen, H.C.K.; Buchmann, Kurt; Mellergaard, Stig

    2000-01-01

    parasiticidal effect: acriflavin (25 ppm), bithionol (0.1 ppm), chloramine T (50 ppm), Detarox AP(R) (45 ppm), malachite green (1 ppm), raw garlic (200 ppm), potassium permanganate (20 ppm) and Virkon PF(R) vet. (20 ppm). Preliminary screening revealed that the anthelmintic, bithionol, and the decomposable...

  4. Immunoreactivity of 125I-papain labelled by different methods

    International Nuclear Information System (INIS)

    Three different methods of papain iodination (with chloramine-T, lactoperoxidase and conjugation with Bolton-Hunter reagent) have been compared. The highest yield of 125I-papain could be obtained using lactoperoxidase which enabled to achieve the highest immunoreactivity. 125I-papain, labelled this way, is suitable for the radioimmunoassay of papain. (author)

  5. The dinoflagellates Pfiesteria shumwayae and Luciella masanensis cause fish kills in recirculation fish farms in Denmark

    DEFF Research Database (Denmark)

    Moestrup, Øjvind; Hansen, Gert; Daugbjerg, Niels;

    2014-01-01

    apparently the first RAS farms in which serious fish kills have been reported. In the marine farm (Luciella) fish mortality increased dramatically despite treatment of the water with peracetic acid and chloramine-T. The plant was temporarily closed down pending investigation into the cause of mortality and...

  6. Photolytic removal of DBPs by medium pressure UV in swimming pool water

    DEFF Research Database (Denmark)

    Hansen, Kamilla Marie Speht; Zortea, R.; Piketty, A.;

    2013-01-01

    Medium pressure UV is used for controlling the concentration of combined chlorine (chloramines) in many public swimming pools. Little is known about the fate of other disinfection by-products (DBPs) in UV treatment. Photolysis by medium pressure UV treatment was investigated for 12 DBPs reported to...

  7. One-pot synthesis of new series 3,4,5-trisubstituted-dihydroisoxazoline derivatives via 1,3-dipolar cycloaddition of nitrile oxides with chalcones

    Indian Academy of Sciences (India)

    Raad Kasim Yhya; K M Lokanatha Rai; Ebraheem Abdu Musad

    2013-07-01

    We have synthesized a series of novel isoxazolines via 1,3-dipolar cycloaddition reaction. Aromatic aldoximes undergo oxidative-dehydrogenation with chloramine-T to give nitrile oxides, which were reacted with chalcones to afford of 3,4,5-trisubstituted 4,5-dihydroisoxazolines in a good yield.

  8. Synthesis of new series of 4, 5-dihydroisoxazole-5-carboxylate derivatives for the study of their liquid crystalline properties

    Indian Academy of Sciences (India)

    SUMANA Y KOTIAN; NARAYANA U KUDVA N; K M LOKANATHA RAI; K BYRAPPA

    2016-07-01

    A new series of 4,5-dihydroisoxazole-5-carboxylate derivatives were synthesized via [3+2] cycloaddition reaction between ethyl acrylate and nitrile oxide generated in situ in presence of Chloramine-T. The synthesized derivatives were characterized by Mass, IR and NMR Spectroscopy and their mesomorphic behavior were studied using DSC and Polarising Optical Microscopy.

  9. Fragmentation of extracellular matrix by hypochlorous acid

    DEFF Research Database (Denmark)

    Woods, Alan A; Davies, Michael Jonathan

    2003-01-01

    /chloramide decomposition, with copper and iron ions being effective catalysts, and decreased by compounds which scavenge chloramines/chloramides, or species derived from them. The effect of such matrix modifications on cellular behaviour is poorly understood, though it is known that changes in matrix materials can have...

  10. IODO-ACID DISINFECTION BY-PRODUCTS IN DRINKING WATER: DOES LC/ESI-MS/MS OFFER AN ADVANTAGE OVER GC/NCI-MS?

    Science.gov (United States)

    As part of a recent Nationwide Disinfection By-Product (DBP) Occurrence Study, iodo-acids were identified for the first time as DBPs in drinking water disinfected with chloramines. The iodo-acids identified included iodoacetic acid, bromoiodoacetic acid, (E)-3-bromo-3-iodo-prope...

  11. OCCURRENCE OF IODO-ACID AND IODO-THM DISINFECTION BY-PRODUCTS IN DRINKING WATER

    Science.gov (United States)

    As part of a recent Nationwide Disinfection By-product (DBP) Occurrence Study, iodo-acids were identified for the first time as DBPs in drinking water disinfected with chloramines. The iodo-acids identified included iodoacetic acid, bromoiodoacetic acid, (E)-3-bromo-3-iodo- prope...

  12. Whole-Genome Sequences of Four Strains Closely Related to Members of the Mycobacterium chelonae Group, Isolated from Biofilms in a Drinking Water Distribution System Simulator

    Science.gov (United States)

    We report the draft genome sequences of four Mycobacterium chelonae group strains from biofilms obtained after a ‘chlorine burn’ in a chloraminated drinking water distribution system simulator. These opportunistic pathogens have been detected in drinking and hospital water distr...

  13. Hypochlorite-induced damage to DNA, RNA, and polynucleotides

    DEFF Research Database (Denmark)

    Hawkins, Clare L; Davies, Michael Jonathan

    2002-01-01

    Stimulated monocytes and neutrophils generate hypochlorite (HOCl) via the release of the enzyme myeloperoxidase and hydrogen peroxide. HOCl is a key bactericidal agent, but can also damage host tissue. As there is a strong link between chronic inflammation and some cancers, we have investigated...... nature of the nucleobase on which they are formed, with chloramines formed from ring heterocyclic amine groups being less stable than those formed on exocyclic amines (RNH2 groups). Evidence is presented for chlorine transfer from the former, kinetically favored, sites to the more thermodynamically...... rationalize the preferential formation of chlorinated 2'-deoxycytidine and 2'-deoxyadenosine in DNA and suggest that DNA damage induced by HOCl, and preformed chloramines, occurs at sequence-specific sites....

  14. Synthesis and radioiodination of analogues of substance P for the building up of a radioimmunoassay

    International Nuclear Information System (INIS)

    The substance P (SP) analogs [Lys(MSOC)3]-SP, [Tyr8]-SP, [Tyr8,Nle11]-SP and [p-HPA1]-SP have been synthesized by classical methods of peptide synthesis as well as by the liquid phase peptide synthesis (LPPS) to allow conjugation with protein in the Nα-position and radioiodination. [Tyr8]-SP and [p-HPA-Arg1]-SP have been radioiodinated by the chloramine T- and the lactoperoxidase method. A complete S-oxidation of SP was observed, when the chloramine T procedure was used, but this modification does not disturb the assay. The introduction of the [125I-pHPA-Arg1]-SP-tracer led to considerable improvements of our SP-radioimmunoassay. (author)

  15. Labelling of human serum albumin with iodine-131 for diagnosis in nuclear medicine

    International Nuclear Information System (INIS)

    Labelling of 131I-human serum albumin with I-131 from a solution of 131I-sodium iodide using chloramine T as an oxidant agent is studied. Parameters which can influence on the labelling yield like mass of human serum albumin, and chloramine T, pH of the reaction, reaction time and activity of 131I are also studied. The purification of the labeled product by means of IRA-410 Amberlite ion-exchange resin in chloride form and the sterilization of the 131I-human serum albumin by its passage through a 0,22μ millipore filter are carried out. The radiochemistry control of the final product by paper chromatography and the microbiological control by cultivation of microorganisms in fluid medium: nutrient broth, sodium thioglycollate broth and Sabouraud, are performed. The stability of the radiopharmaceutical until ten days after its preparation is analysed by means of radiochemical control. (Author)

  16. Preparation and Evaluation of (125I) Daunorubicin as a Potential Agent for Tumor Detection and radiotherapy

    International Nuclear Information System (INIS)

    In this study, the optimization of daunorubicin labeling with iodine-125 and its biological evaluation were described. Daunorubicin was labeled via direct electrophilic substitution using chloramine-T as oxidizing agent. The optimum amounts of reactants were: 40μg daunorubicin, 30μg Chloramine-T and ∼ 19 KBq carrier free Na125I. The labeled daunorubicin was stable for more than 24 hours. Results of the in-vivo evaluation revealed that the tracer, [125I] daunorubicin, tends to localize in tissues with high proliferation rate with preferential accumulation in cancerous tissues. Imaging should be carried at 3 hours post injection. The in-vitro cell growth inhibition assay showed that the effect of [125I] Daunorubicin was stronger than the effect of cold daunorubicin which strongly suggested that its cytotoxicity was mainly due to radiotoxicity rather than chemotherapeutic activity.

  17. The efficiency of different disinfecting agents in inactivating microorganisms detected in natural and treated waters; Eficiencia de diferentes agentes desinfectantes en la inactivacion de microorganismos detectados en aguas naturales y tratadas

    Energy Technology Data Exchange (ETDEWEB)

    Perez Recuerda, R.; Sanchez, J.M.; Borrego, J.J.

    1998-12-01

    The efficiency of microbial inactivation and sublethal injury of six disinfectants (chlorine, chloramines, uV-light, potassium permanganate, fluor and ozone) applied at different dose on several bacterial strains, yeast and viruses has been studied comparatively. Disinfectant effect was higher on Gramnegative bacteria (Salmonella, Pseudomonas, Escherichia and Klebsiella) than on Gram-positive (Clostridium, Enterococcus and Stanphylococcus); although the least inactivation effect was obtained on the MS-2 bacteriophage. The global efficiency ranking of the disinfectants assayed to produce the microbial inactivation was as follows; ozone>chlorine>UV-light>chloramines>permanganate>fluor. On the other hand, on Escherichia coli and Pseudomonas aerugionosa were observed the highest sublethal injuries provokes by the disinfectants and dose assayed. Therefore, these microorganisms are the main candidates to regrow and to form biofilm in drinking water distribution systems. 34 refs. (Author)

  18. Kinetics and Mechanism of Electron Transfer Reaction: Oxidation of Sulfanilic Acid by N-Chloro-p-Toluene Sulfonamide in Acid Perchlorate Medium

    Energy Technology Data Exchange (ETDEWEB)

    Sailani, Riya; Bhasin, Meneka; Khandelwal, C. L.; Sharma, P. D. [Univ. of Rajasthan, Jaipur (India)

    2014-01-15

    The kinetics and mechanism of oxidation of sulfanilic acid by N-chloro-p-toluene sulfonamide (chloramine-T) have been studied in acid medium. The species of chloramine-T were analysed on the basis of experimental observations and predominantly reactive species was taken into account for proposition of most plausible reaction mechanism. The derived rate law (1) conforms to such a mechanism. All kinetic parameters were evaluated. Activation parameters such as energy and entropy of activation were calculated to be (61.67 ± 0.47) kJ mol{sup -1} and (-62.71 ± 2.48) JK{sup -1}mol{sup -1} respectively employing Eyring equation.

  19. Development and applications of a radioimmunoassay to human plasma kallikrein

    International Nuclear Information System (INIS)

    A radioimmunoassay to human plasma kallikrein (Hu PK) was developed using specific antibodies against the purified activates enzyme. The antiserum showed identity in the precipitation, double immuno-diffusion, immobility, immuno-electrophoresis, using as normal plasma as purified kallikrein. The protein 125 I-kallikrein was prepared by chloramine-t method and presented homogeneity, stability, immunoactivity and high specific activity, so that a sensitive assay was assured. 193 refs., 19 figs., 4 tabs

  20. Use of mechanism-based structure-activity relationships analysis in carcinogenic potential ranking for drinking water disinfection by-products.

    OpenAIRE

    Woo, Yin-Tak; Lai, David; McLain, Jennifer L; Manibusan, Mary Ko; Dellarco, Vicki

    2002-01-01

    Disinfection by-products (DBPs) are formed when disinfectants such as chlorine, chloramine, and ozone react with organic and inorganic matter in water. The observations that some DBPs such as trihalomethanes (THMs), di-/trichloroacetic acids, and 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) are carcinogenic in animal studies have raised public concern over the possible adverse health effects of DBPs. To date, several hundred DBPs have been identified. To prioritize research effor...

  1. Human growth hormone (HGH), ch. 6

    International Nuclear Information System (INIS)

    A radioimmunoassay method for the human growth hormone (HGH) is described. The requirements are discussed in detail and a scheme for the preparation of incubation mixtures is given. HGH is labelled with 125I by the chloramine T method and purified by gel filtration or electrophoresis. Separation of bound and free-labelled hormones is performed by absorption of the free hormone, using talc or charcoal

  2. Occurrence of by-products of strong oxidants reacting with drinking water contaminants--scope of the problem.

    OpenAIRE

    Rice, R G; Gomez-Taylor, M

    1986-01-01

    This paper describes results of a detailed literature review of the organic and inorganic by-products that have been identified as being formed in aqueous solution with four of the strong oxidizing/disinfecting agents commonly employed in drinking water treatment. These agents are: chlorine, chlorine dioxide, chloramine, and ozone. Significant findings include the production of similar nonchlorinated organic oxidation products from chlorine, chlorine dioxide, and ozone. In addition, all three...

  3. Detachment of cultured cells from the substratum induced by the neutrophil-derived oxidant NH2Cl: synergistic role of phosphotyrosine and intracellular Ca2+ concentration

    OpenAIRE

    1995-01-01

    The neutrophil-derived, membrane-permeating oxidant, NH2Cl, (but not the non-membrane-permeating chloramine, taurine-NHCl) induced detachment of fetal mouse cardiac myocytes and other cell types (fibroblasts, epithelial cells, and endothelial cells) from the culture dish, concomitant with cell shrinkage ("peeling off"). Stimulated human neutrophils also induced peeling off of cultured mouse cardiac myocytes when the latter were pretreated with inhibitors of .OH and elastase. Immunofluorescenc...

  4. Exhaled nitric oxide and airway hyperresponsiveness in workers: a preliminary study in lifeguards

    OpenAIRE

    Massin Nicole; Bohadana Abraham; Demange Valérie; Wild Pascal

    2009-01-01

    Abstract Background Airway inflammation and airway hyperresponsiveness (AHR) are two characteristic features of asthma. Fractional exhaled nitric oxide (FENO) has shown good correlation with AHR in asthmatics. Less information is available about FENO as a marker of inflammation from work exposures. We thus examined the relation between FENO and AHR in lifeguards undergoing exposure to chloramines in indoor pools. Methods 39 lifeguards at six indoor pools were given a respiratory health questi...

  5. The effect of pre-oxidation on NDMA formation and the influence of pH.

    Science.gov (United States)

    Selbes, Meric; Kim, Daekyun; Karanfil, Tanju

    2014-12-01

    N-nitrosodimethylamine (NDMA), a probable human carcinogen, is a disinfection by-product that has been detected in chloraminated drinking water systems. Pre-oxidation of the NDMA precursors prior to chloramination can be a viable approach for water utilities to control the NDMA levels. This study examined the effects of (i) commonly used oxidants (i.e., chlorine, chlorine dioxide and ozone) in water treatment, (ii) oxidant concentration and contact time (CT), and (iii) pre-oxidation pH on the formation of NDMA from subsequent chloramination. Fifteen model precursors with NDMA molar yields ranging from approximately 0.1%-90% were examined. Pre-chlorination reduced NDMA formation from most precursors by 10%-50% except quaternary amine polymers (i.e., PolyDADMAC, PolyACRYL, PolyAMINE). Pre-oxidation with chlorine dioxide and ozone achieved the same or higher deactivation of NDMA precursors (e.g., ranitidine) while increasing NDMA formation for some other precursors (e.g., daminozid). The increases with chlorine dioxide exposure were attributed to the release of oxidation products with dimethylamine (DMA) moiety, which may form more NDMA upon chloramination than the unoxidizied parent compound. On the other hand, chlorine dioxide was effective, if a precursors NDMA yield were higher than DMA. The ozone-triggered increases could be related to direct NDMA formation from DMA which are released by ozonation of amines with DMA moiety, amides or hydrazines. However, hydroxyl radicals formed from the decomposition of ozone would be also involved in decomposition of formed NDMA, reducing the overall NDMA levels at longer contact times. pH conditions influenced significantly the effectiveness of deactivation of precursors depending on the type of precursor and oxidant used. PMID:25203542

  6. Chlorination of Taurine by Human Neutrophils: EVIDENCE FOR HYPOCHLOROUS ACID GENERATION

    OpenAIRE

    Weiss, Stephen J; Klein, Roger; Slivka, Adam; Wei, Maria

    1982-01-01

    The model hydrogen peroxide-myeloperoxidase-chloride system is capable of generating the powerful oxidant hypochlorous acid, which can be quantitated by trapping the generated species with the β-amino acid, taurine. The resultant stable product, taurine chloramine, can be quantitated by its ability to oxidize the sulfhydryl compound, 5-thio-2-nitro-benzoic acid to the disulfide, 5,5′-dithiobis(2-nitroben-zoic acid) or to oxidize iodide to iodine. Using this system, purified myeloperoxidase in...

  7. Ethyl 4,4''-Difluoro-5'-hydroxy-1,1':3',1''-terphenyl-4'-carboxylate

    Directory of Open Access Journals (Sweden)

    Badiadka Narayana

    2011-11-01

    Full Text Available A simple and novel route for the synthesis of new terphenyl derivative as well as oxidative aromatization of α,β-unsaturated cyclohexenone to the corresponding phenol derivative is developed. The present work involves the condensation of ethylacetoacetate with 4,4'-difluoro chalcone followed by the aromatization using chloramine-T in acetic acid to yield the title compound (3. The synthesized compound (3 is well characterized by IR, NMR, LCMS and elemental analysis.

  8. Ethyl 4,4''-Difluoro-5'-hydroxy-1,1':3',1''-terphenyl-4'-carboxylate

    OpenAIRE

    Badiadka Narayana; Balladka Kunhanna Sarojini; Seranthimata Samshuddin

    2011-01-01

    A simple and novel route for the synthesis of new terphenyl derivative as well as oxidative aromatization of α,β-unsaturated cyclohexenone to the corresponding phenol derivative is developed. The present work involves the condensation of ethylacetoacetate with 4,4'-difluoro chalcone followed by the aromatization using chloramine-T in acetic acid to yield the title compound (3). The synthesized compound (3) is well characterized by IR, NMR, LCMS and elemental analysis.

  9. New aquaculture drugs under FDA review

    Science.gov (United States)

    Bowker, James D.; Gaikowski, Mark P.

    2012-01-01

    Only eight active pharmaceutical ingredients available in 18 drug products have been approved by the U.S. Food and Drug Administration for use in aquaculture. The approval process can be lengthy and expensive, but several new drugs and label claims are under review. Progress has been made on approvals for Halamid (chloramine-T), Aquaflor (florfenicol) and 35% PeroxAid (hydrogen peroxide) as therapeutic drugs. Data are also being generated for AQUI-S 20E, a fish sedative.

  10. Synthetic heparinoids labelled with 125I and 35S

    OpenAIRE

    Sederel, L.C.; Kolar, Z.; Does, van der, Leen; Bantjes, A.

    1982-01-01

    The labelling of a water-soluble synthetic polyelectrolyte, having anticoagulant activity, has been studied. The polyelectrolyte is derived from cis-1,4-polyisoprene and contains N-sulfate and carboxylate groups. [125I]-Iodination of the polyelectrolyte, using the Chloramine-T method and an electrolytic method, resulted in a [125I]-labelled polyelectrolyte from which release of the label occurred. Resulfation of a partially desulfated polyelectrolyte with a [35S]-sulfur trioxide trimethylamin...

  11. Combined toxicity effects of chlorine, ammonia, and temperature on marine plankton. Progress report, February 1, 1975--September 15, 1975

    Energy Technology Data Exchange (ETDEWEB)

    Ryther, J. H.; Goldman, J. C.

    1975-10-01

    Research on the combined effects of chlorine, ammonia, and temperature on marine plankton have been carried out for 7/sup 1///sub 2/ months. Continuous-flow bioassay units have been constructed for larval species, juvenile fish, and phytoplankton. A detailed study on lobster (Homarus americanus) larvae and other studies on killifish (Fundulus heteroclitus) larvae and juveniles, and juvenile scup (Stenotomus versicolor) and winter flounder (Pseudopleuronectes americanus) have been performed. Results to date indicate that there is an apparent and, as yet undetermined, chlorine demand of seawater; there is a differential toxic effect of chlorine and chloramines--lobsters were more sensitive to chloramines, whereas the fish species were more affected by free chlorine; respiration results indicate that significant stress occurs at toxicant levels below the onset of mortality, thus raising questions regarding the applicability of standard bioassay data; temperature elevation exerts a strong synergistic effect on chlorine-chloramine toxicity; and effects of exposure to halogen toxicity appear irreversible as revealed by persistent reductions in metabolic activity. It appears that chlorine toxicity to marine biota can occur even though chlorine residuals cannot be detected by current analytical techniques. These results support the findings of others that chlorine toxicity is a serious environmental pollutant. (auth)

  12. Hypochlorite-induced oxidation of proteins in plasma

    DEFF Research Database (Denmark)

    Hawkins, C L; Davies, Michael Jonathan

    1999-01-01

    Activated phagocyte cells generate hypochlorite (HOCl) via the release of H2O2 and the enzyme myeloperoxidase. Plasma proteins are major targets for HOCl, although little information is available about the mechanism(s) of oxidation. In this study the reaction of HOCl (at least 50 microM) with dil......Activated phagocyte cells generate hypochlorite (HOCl) via the release of H2O2 and the enzyme myeloperoxidase. Plasma proteins are major targets for HOCl, although little information is available about the mechanism(s) of oxidation. In this study the reaction of HOCl (at least 50 micro......M) with diluted fresh human plasma has been shown to generate material that oxidizes 5-thio-2-nitrobenzoic acid; these oxidants are believed to be chloramines formed from the reaction of HOCl with protein amine groups. Chloramines have also been detected with isolated plasma proteins treated with HOCl. In both....... These results are consistent with protein-derived chloramines, and the radicals derived from them, as contributing agents in HOCl-induced plasma protein oxidation....

  13. Pituitary human growth hormone: small-scale purification method and application to radioimmunoassay

    International Nuclear Information System (INIS)

    Human growth hormone (hGH) extracted from pituitary glands is often heterogeneous, presenting, besides the native isohormone - B (IH-B) up to four different isohormones. To obtain more homogeneous preparations, essential for reproduceble radioligand assay results, the original method was modified, on a small scale, and by adding bacteriostatic and enzime inhibiting agents to all buffers (NaN3, EDTA, Trasylol) in order to minimize isohormone formation. After 3 to 4 homogeneizations and extractions of the frozen glands (10-20), hGH is precipitated, by 50% ammonium sulphate immediatly purified by Sephadex G 100 molecular sieve chromatography and hGH fractions are lyophilized. The whole process is completed in one week. Using 20 hypophises, 1.3 mg/gland was obtained. Several labellings with 125-I were performed using this purified hGH stored for more than one year. Two labelling techniques were employed: the classical method which uses 50 μg of Chloramine T and the stoichiometric iodination, which uses limiting amounts of chloramine T. For this preparation only 1.5 μg Chloramine T were necessary to achieve the desired specific activity. (author)

  14. Detection of sewage organic chlorination products that are resistant to dechlorination with sulfite

    Energy Technology Data Exchange (ETDEWEB)

    MacCrehan, W.A. [National Inst. of Standards and Technology, Gaithersburg, MD (United States). Analytical Chemistry Div.; Jensen, J.S.; Helz, G.R. [Univ. of Maryland, College Park, MD (United States). Dept. of Chemistry and Biochemistry

    1998-11-15

    Most of the 36 billion gal of treated sewage wastewater discharged daily into the environment in the United States is disinfected via chlorination. To minimize toxicity. dechlorination with sulfite or sulfur dioxide is often performed. Although dechlorination is considered instantaneous and complete, several studies have found residual toxicity of chlorinated/dechlorinated effluent to aquatic life. The authors investigated chlorination/dechlorination of the organic nitrogen components of sewage wastewater using both iodometric titration and a novel LC method. For LC, a postcolumn reaction with iodide rendered submicromolar chloramine concentrations detectable with amperometry. Using a gradient-elution LC separation, the retention and dechlorination behavior of a suite of model amines was determined, representing primary and secondary aliphatic, peptide, and protein-N. Chlorination/dechlorination experiments on freshly collected, tertiary-treated wastewater showed a fraction of the organic N-chloramines are dechlorinated slowly by sulfite with half-lives of >20 min. Chromatographic retention and kinetic behavior of the sewage N-chloramines was consistent with the behavior of the model peptides and proteins. Proteolytic hydrolysis markedly increased the peptide fraction observed upon chlorination of the wastewater. These results suggest that peptides and proteins contribute to slow dechlorination of sewage and may be a factor in the toxicity noted for chlorine-disinfected wastewater.

  15. Formation and occurrence of new polar iodinated disinfection byproducts in drinking water.

    Science.gov (United States)

    Pan, Yang; Li, Wenbin; An, Hao; Cui, Hao; Wang, Ying

    2016-02-01

    During drinking water disinfection, iodinated disinfection byproducts (I-DBPs) can be generated through reactions between iodide, disinfectants, and natural organic matter. Drinking water I-DBPs have been increasingly attracting attention as emerging organic pollutants as a result of their significantly higher toxicity and growth inhibition than their chloro- and bromo-analogues. In this study, by adopting ultra performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry precursor ion scan, multiple reaction monitoring, and product ion scan analyses, 11 new polar I-DBPs with confirmed structures and eight new polar I-DBPs with proposed structures were detected in simulated drinking water samples. Chloramination of simulated raw waters containing natural organic matter with higher aromaticity produced higher levels of new phenolic I-DBPs. Formation of new polar I-DBPs and total organic iodine (TOI) was most favored in chloramination, followed by chlorine dioxide treatment, and relatively minor in chlorination. Lower pH in chloramination substantially enhanced the formation of new polar I-DBPs and TOI. NH2Cl and dissolved organic nitrogen could be important nitrogen sources and precursors for formation of the two new nitrogenous phenolic I-DBPs. Notably, in tap water samples collected from nine major cities located in the Yangtze River Delta region of China, seven of the 11 new polar I-DBPs with confirmed structures were detected at levels from 0.11 to 28 ng/L, and the two new nitrogenous phenolic I-DBPs were ubiquitous with concentrations from 0.12 to 24 ng/L, likely due to the relatively high dissolved organic nitrogen levels in regional source waters. PMID:26606185

  16. Tissue culture of horse-radish (Cochlearia armoracia L. meristems: sterilization of buds and comparison of media

    Directory of Open Access Journals (Sweden)

    K. Górecka

    2015-06-01

    Full Text Available The attempt was made to cultivate horse-radish meristems taken from buds removed from roots. The lowest per cent of contamination was found after the buds had been soaiked in 80% ethanol for 6 minutes and then in 5%, 7.5% or 10% chloramine for 30, 30 or 15 minutes, respectively. Both agar media: Murashige-Skoog and Linsmaier-Skoog, were equally good, providing a moderate number of developing plants. The Linsmaier-Skoog medium was more satisfactory when solidified with agar; the results with liquid medium and filter-paper bridges were not as good.

  17. The distribution and excretion of nerve growth factor in mice

    International Nuclear Information System (INIS)

    Nerve growth factor (NGF) was iodolabelled with chloramine-T method and its distribution and excretion in mice were investigated. The results showed that the highest levels were found in superior cervical ganglia, thyroid, bile, kidneys and adrenals between 20-30 min after injection, and the peak time in most tissues was also found at 20-30 min. About 72.55% of the injected dose was excreted in stool and urine, among them 65.6% was excreted in urine and only 7.0% in stool within 72 h after intramuscular injection

  18. Radioiodination of the protein complex of the VA-MENGOC-BC vaccine

    International Nuclear Information System (INIS)

    In this work was made the labelling of the protein complex of the vaccine VA-MEMGOC-BC with I-125 in order to study its immunological responses. These proteins were in both forms: dissolved and conjugated with polisacarids of the C-group. There were used three methods of iodination: chloramine-T iodogen and lactoperoxidase. Was found out that dissolved proteins can be iodinated using these methods with 0,1 mCi of I-125, and the obtained specific activities were similar

  19. Studies on the Radioimmunoassay of Human Growth Hormone - 1. Evaluation of the method of determination

    International Nuclear Information System (INIS)

    Utilizing the commercial radioimmunoassay kit, the author assayed HGH and evaluated the problems of the method. The method had the sensitivity of 0.5 mug/ml degree and could determine the plasma HGH concentration directly without the help of plasma extraction. Also it was specific for the HGH, when tested by a dilution method using test utilizing the plasma of the acromegalic patient. The author also obtained the 125I labelled HGH of specific activity of 156. 3 μCi/μg, performing the chloramine-T method.

  20. The tritium kinetic isotope effect for the iodination of L-(5-3H) -3-iodotyrosine

    International Nuclear Information System (INIS)

    The kinetic tritium isotope effect k(subH)/k(subT) for the iodination of L-(5-3H)-3-iodotyrosine at pH 7.5 was found to be 4.29 +-0.25 with molecular iodine and 4.50 +- 0.26 with chloramine-T/potassium iodide. This effect establishes that the rate-limiting step is proton removal by the general base. A novel method for measuring the fraction of tritiated water by high performance liquid chromatography is described

  1. Comparison of 131I-TYR3-octreotate and 131I-DOTA-TYR3-octreotate: The effect of DOTA on pharmacokinetics and stability

    International Nuclear Information System (INIS)

    The authors compared the biodistribution, and in vivo and in vitro stabilities of 131I-Tyr3-octreotate and 131I-DOTA-Tyr3-octreotate. The peptides were radioiodinated by the chloramine T method and high radiochemical yields were obtained (greater than 97%). Both labelled compounds showed high stability when incubated in human plasma at 37 deg C. The 131I-Tyr3-octreotate showed significant hepatic uptake and biliary excretion. The biodistribution of 131I-DOTA-Tyr3-octreotate, however, can be compared with the distribution of radiometal labelled octreotide analogues. (author)

  2. Qualitative and quantitative evaluation of donkeys responses to immunization by rabbits' IgG

    International Nuclear Information System (INIS)

    In this study two apparently healthy donkeys were immunized with highly pure rabbit's 1gG using a revised protocol. Qualitative test using the same immuno gen was done as a primary test to eva lute the immune system response. However, the same 1gG was iodinated with 125I using chloramine T method and the labeled 1gG was used to quantitatively study the immune response. The two donkeys showed good response with the younger one having the best response. The obtained donkey anti rabbit sera was used as separating agent for RIA assay for human PRL. (Author)

  3. optimization of insulin radioreceptor assay in human erythrocytes in normal and some disease status

    International Nuclear Information System (INIS)

    This study is concerned with the evaluation of a new optimized technique for the principle of chloramine-T method used for insulin iodination by 125I-radioisotope with some modifications. The modified procedure can be carried out under normal condition of room temperature, employed longer reaction times and omitted the addition of inorganic reducing salts, maintaining efficient iodination and avoiding denaturations to obtain labels of exceedingly high specific activity on a small quantities of insulin for in vitro usage in the investigation of human erythrocytes 125 I-insulin binding capacity in normal and some disease status

  4. Gradient polyacrylamide electrophoretic analysis of radioiodinated proteins from synaptosomes and mitochondria

    International Nuclear Information System (INIS)

    Fractions enriched in synaptosomes or mitochondria from swine brain, and mitochondria from beef heart were 125I-iodinated using either lactoperoxidase (LP) or chloramine= T catalysis. The labelled proteins were analysed by radioautography after high resolution gradient polyacrylamide gel electrophoresis. More radiolabelled protein bands were found in the brain mitochondrial fraction than in the synaptosomal fraction after LP catalysed iodination, but the protein labelling patterns of the brain organelles were similar. Comparison of the results of the two labelling procedures cannot therefore be used for the unambiguous determination of the topographic organization of the proteins in synaptic membranes. (U.K.)

  5. Preparation of iodine-123 labeled AM251: a potential SPECT radioligand for the brain cannabinoid CB1 receptor

    International Nuclear Information System (INIS)

    We report the synthesis and labeling with iodine-123 of N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2, 4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM251). This compound is an analog of the recently described cannabinoid receptor antagonist, SR141716A, in which a 4-chlorophenyl group is replaced by 4-iodophenyl. Labeling in good yield (62%) and radiochemical purity (> 95%), and high specific activity (> 2500 Ci/mmol) was achieved by an iododestannylation reaction using the tributyltin precursor, no carrier added I-123 iodide, and chloramine-T. (author)

  6. Die Auswirkung der Applikationszeit und Applikationsart eines selbst-ätzenden Adhäsivsystems auf die Randständigkeit von Klasse-V-Füllungen im Schmelz und Dentin

    OpenAIRE

    Lübke, Fabian Alexander

    2010-01-01

    The purpose of this study was to evaluate the effect of different application procedures, such as time and method of application, or number of the application layers, using a self-etching all-in-one adhesive on the marginal integrity of Class V cavities in enamel and dentin. Therefore standardized Class V cavities were labially prepared into 136 extracted human caries-free maxillary-middle incisors, stored in a 0.5 % chloramine solution. The extension of each cavity was 4.0 mm in coronal-a...

  7. Radioimmunological determination of procollagen (type III) and procollagen peptide (type III)

    International Nuclear Information System (INIS)

    The detection of antigens circulating in the blood enables the early recognition of fibrotic processes e.g. liver cirrhosis and hepatitis. One thus uses an anti procollagen (type III) labelled with iodine 125 by the chloramine-T method, or an anti-procollagen peptide (type III) serum which is brought together with a sample of unknown contents. The separation of the antigen-antibody complex is carried out by means of a highly specific antiserum. The procollagen peptide (type III) is produced from calf skin of a foetus or from human aszites fluid. (DG)

  8. Radioiodinated iodophenyl maleimide: A potential radioimmunoconjugate with low in vivo deiodination

    International Nuclear Information System (INIS)

    The conceptual design and feasibility of a new sulfhydryl radiolabeled agent, N-(4-[125I]iodophenyl)maleimide, as a potential radioimmunoconjugate is described. The distribution of bovine serum albumin when labeled with 131I by the chloramine-T oxidation procedure or with 125I by maleimide conjugation was studied in normal female Fischer rats. The 125I-iodophenylmaleimide labeled bovine serum albumin showed significantly lower thyroid uptake (1.03% injected dose) and hence greater stability than the 131I labeled bovine serum albumin (4.85% injected dose) at 24 h. This promising result indicates need for further evaluation of iodophenylmaleimide as a potential radioimmunoconjugate. (orig.)

  9. Methods for labelling triiodo thyroxin (T3) and L-thyroxin (T4) with I-125 used in radioimmunoassay

    International Nuclear Information System (INIS)

    A rapid and sensitive radioimmunoassay has been developed for the measurement of T3 and T4 in human serum. This method is particularly useful for evaluating hyperthyroidism and hypothyroidism in patient with thyroid disease. T3 and T4 has been labelled with I-125 using chloramin-T method to attain tracers with specific activity 2500-3000μCi/μg. Iodinated products have radiochemical purity more than 98% (by paper electrophoresis of purified pooled fraction), immunoreactivity above 70%, non specific binding (NSB) less than 10%, used as tracer in RIA. (author)

  10. The experience with setting-up radioimmunoassay for alpha-1 fetoprotein

    International Nuclear Information System (INIS)

    The decisive factor in the preparation of radioimmunological alpha-1-fetoprotein determination, provided sufficient commercial or own antisera and standards are available for calibration, is the quality of the preparation for labelling. Alpha-1-fetoprotein was separated by affinity chromatography using Sepharose with alpha-1-fetoprotein-bound antibodies. The isolates thus obtained were labelled with 125I using enzyme and chloramine T and Iodogen techniques. The labelled alpha-1-fetoprotein can be used for RIA. In view of reduced immunoreactivity of the preparation, however, the performance of the radioimmunological determination has so far not matched the quality of imported kits. The technique is currently being optimized. (author)

  11. Preparation of iodine-123 labeled AM251: a potential SPECT radioligand for the brain cannabinoid CB1 receptor

    Energy Technology Data Exchange (ETDEWEB)

    Lan, Ruoxi; Makriyannis, Alexandros [Connecticut Univ., Molecular and Cell Biology Dept., Storrs, CT (United States); Gatley, S.J. [Brookhaven National Lab., Medical Dept., Upton, NY (United States)

    1996-10-01

    We report the synthesis and labeling with iodine-123 of N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2, 4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM251). This compound is an analog of the recently described cannabinoid receptor antagonist, SR141716A, in which a 4-chlorophenyl group is replaced by 4-iodophenyl. Labeling in good yield (62%) and radiochemical purity (> 95%), and high specific activity (> 2500 Ci/mmol) was achieved by an iododestannylation reaction using the tributyltin precursor, no carrier added I-123 iodide, and chloramine-T. (author).

  12. Fungicidal effect of 15 disinfectants against 24 fungal contaminants commonly found in bread and cheese manufacturing

    DEFF Research Database (Denmark)

    Bundgaard-Nielsen, Kirsten; Nielsen, Per Væggemose

    1996-01-01

    Resistance of 19 mold- and 6 yeast- species against 15 commercial disinfectants was investigated by a suspension-method in which the fungicidal effect and germination time were determined at 20 °C. Disinfectants containing 0.5 % dodecyldiethylentriaminacetic acid, 10 g/l chloramine-T, 2....... The examined isolates of P. roqueforti var. carneum, P. discolor, Aspergillus versicolor and Eurotium repens were resistant to different quaternary ammonium compounds. Conidia and vegetative cells were killed by alcohols, whereas ascospores were resistant. Resistance of ascospore to 70% ethanol...

  13. Isolation of a somatomedin binding protein from human preterm amniotic fluid: development of a radioimmunoassay

    International Nuclear Information System (INIS)

    This thesis investigates the nature and biological behaviour of a somatomedin binding protein, identified in preterm amniotic fluid (AF). For that purpose a double antibody radioimmunoassay was developed. Purified AF binding protein (AFBP) was iodinated by the chloramine-T method, and dilutions of partially purified AFBP were designated as the standard, with the results expressed in μg equivalent protein/ml. The sensitivity of the assay was improved by adoption of the nonequilibrium procedure. AFBP values were twice as high in preterm AF as in term AF. (Auth.)

  14. Preparation of stable 125I cyclic GMP tyrosine methyl ester suitable for 3',5' cyclic GMP radioimmunoassay by HPLC

    International Nuclear Information System (INIS)

    Determination of the concentration of cyclic guanosine monophosphate (cGMP) by radioimmunoassay (RIA) depends upon the availability of suitable radiolabeled tracers and antibody to detect the product. Reverse phase chromatographic techniques can easily separate the reaction products of chloramine-T iodination of succinyl cGMP tyrosine methyl ester. The binding characteristics of the iodination reaction products to anti-cGMP antibody have been determined. Purified succinyl cyclic nucleotide 125I-tyrosine methyl ester binds to cGMP antisera identically as commercially available tracer. The tracer is stable for greater than three months

  15. Contribution of N-Nitrosamines and Their Precursors to Domestic Sewage by Greywaters and Blackwaters.

    Science.gov (United States)

    Zeng, Teng; Mitch, William A

    2015-11-17

    N-nitrosamines and their precursors are significant concerns for water utilities exploiting wastewater-impacted water supplies, particularly those practicing potable reuse of wastewater. Previous efforts to identify specific precursors in municipal wastewater accounting for N-nitrosamine formation have met with limited success. As an alternative, we quantified the relative importance of greywater (i.e., shower, kitchen sink, bathroom washbasin, and laundry) and blackwater (i.e., urine and feces) streams in terms of their loadings of ambient specific and total N-nitrosamines and chloramine-reactive and ozone-reactive N-nitrosamine precursors to domestic sewage. Accounting for the volume fractions of individual greywater and blackwater streams, laundry water represented the most significant source of N-nitrosamines and their precursors, followed by shower water and urine. Laundry water was particularly important for ozone-reactive N-nitrosamine precursors, accounting for ∼99% of N-nitrosodimethylamine (NDMA) precursors and ∼69% of precursors for other uncharacterized N-nitrosamines. For the other greywater streams, consumer products contributed additional N-nitrosamines and precursors, but the remarkable uniformity across different products suggested the importance of common macroconstituents. The consumption of a standard dose of the antacid ranitidine substantially increased NDMA and its chloramine-reactive precursors in urine. Nevertheless, nearly 40% of the American population would need to consume ranitidine daily to match the NDMA loadings from laundry water. PMID:26496512

  16. Monochloramine Cometabolism by Mixed-Culture Nitrifiers under Drinking Water Conditions.

    Science.gov (United States)

    Maestre, Juan P; Wahman, David G; Speitel, Gerald E

    2016-06-21

    Chloramines are the second most used secondary disinfectant by United States water utilities. However, chloramination may promote nitrifying bacteria. Recently, monochloramine cometabolism by the pure culture ammonia-oxidizing bacteria, Nitrosomonas europaea, was shown to increase monochloramine demand. The current research investigated monochloramine cometabolism by nitrifying mixed cultures grown under more relevant drinking water conditions and harvested from sand-packed reactors before conducting suspended growth batch kinetic experiments. Four types of batch kinetic experiments were conducted: (1) positive controls to estimate ammonia kinetic parameters, (2) negative controls to account for biomass reactivity, (3) utilization associated product (UAP) controls to account for UAP reactivity, and (4) cometabolism experiments to estimate cometabolism kinetic parameters. Kinetic parameters were estimated in AQUASIM with a simultaneous fit to the experimental data. Cometabolism kinetics were best described by a first-order model. Monochloramine cometabolism kinetics were similar to those of ammonia metabolism, and monochloramine cometabolism accounted for 30% of the observed monochloramine loss. These results demonstrated that monochloramine cometabolism occurred in mixed cultures similar to those found in drinking water distribution systems; therefore, monochloramine cometabolism may be a significant contribution to monochloramine loss during nitrification episodes in drinking water distribution systems. PMID:27196729

  17. Transformation of pharmaceuticals during oxidation/disinfection processes in drinking water treatment

    Energy Technology Data Exchange (ETDEWEB)

    Postigo, Cristina [Institute for Environmental Assessment and Water Research (IDAEA)—Spanish National Research Council (CID-CSIC), Barcelona (Spain); Richardson, Susan D., E-mail: richardson.susan@sc.edu [Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC (United States)

    2014-08-30

    Graphical abstract: - Highlights: • Review of transformation pathways of pharmaceuticals during disinfection processes. • DBPs are formed with chlorine, chloramine, ozone, chlorine dioxide, UV, or UV/H{sub 2}O{sub 2}. • Chlorine reacts with amine and reduced sulfur groups and activated aromatic systems. • Chlorine dioxide and ozone react with electron-rich functional groups. • Potential health effects are noted for some pharmacuetical DBPs when available. - Abstract: Pharmaceuticals are emerging contaminants of concern and are widespread in the environment. While the levels of these substances in finished drinking waters are generally considered too low for human health concern, there are now concerns about their disinfection by-products (DBPs) that can form during drinking water treatment, which in some cases have been proven to be more toxic than the parent compounds. The present manuscript reviews the transformation products of pharmaceuticals generated in water during different disinfection processes, i.e. chlorination, ozonation, chloramination, chlorine dioxide, UV, and UV/hydrogen peroxide, and the main reaction pathways taking place. Most of the findings considered for this review come from controlled laboratory studies involving reactions of pharmaceuticals with these oxidants used in drinking water treatment.

  18. Preparation of 125I-labelled thyroid hormones for use in radioimmunoassay. Part of a coordinated programme on quality control of techniques in-vitro assay of thyroid-related hormones (Latin America)

    International Nuclear Information System (INIS)

    The primary objective was to prepare 125I labelled thyroid hormones for use in radioimmunoassays. T4 and T3 of very high specific activity was obtained by just labelling T2. With a molar relation of T2:125I as 1:2 and Chloramine T:125I as 60:1 it was possible to produce T4125I of approximately 3,300 to 3,800 uc/ug and T3125I of 1,800 and 2,500 uc/ug with reaction times of 60'' to 90''. Simultaneous production from T2 of both labelled T4 and T3 of high specific activity appears to be the best choice for routine radioimmunoassays. Various permutations of the molar relations between T2 and 125I and between chloramine T and 125I it was possible to produce labelled T3 and T4 of varying degrees of specificities. The labelled products can be separated by sephadex G25 chromatography with good resolution. The separation is still improved if sephadex LH-20 is used. T4 and T3 of very high specific activity is preserved best for about a month in Cyst-PG-Alb. Low specific activity material can be preserved in the same medium for about 3 months

  19. Immunoradiometric assay (IRMA) for hTSH - anti -hTSH monoclonal antibody (MAb) radioiodination

    International Nuclear Information System (INIS)

    Thyroid-stimulating hormone (TSH) is a glycoprotein secreted by pituitary gland and has a specific site of action which is the thyroid gland. Its main function is to regulate the release of thyroxine (T4) and of triiodothyronine (T3) and to control different stages of their synthesis. The test of measuring TSH levels is a screening test for the diagnosis of thyroid disease. An IRMA - TSH procedure was developed in order to determine the concentration of TSH in human serum samples. Two antibodies are involved in this assay system, one of which is 125 I radiolabelled. The aim of this work is to report the method of monoclonal antibody TSH 125 I radioiodination. Anti - TSH monoclonal antibody obtained from Medix Biochemica Finland was labelled by the Chloramine T method, using 10 mg of Chloramine T and 1 mCi of 125 I; the reaction time was 1 minute and the reaction was stopped by addition of 20 mg of sodium metabisulphite. Purification of radioiodinated anti - TSH monoclonal antibody was performed on a Sephadex G - 150 column, using for elution 0.05 M phosphate buffer. The studies in order to produce a IRMA -TSH kit are in progress. (authors)

  20. Transformation of pharmaceuticals during oxidation/disinfection processes in drinking water treatment

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Review of transformation pathways of pharmaceuticals during disinfection processes. • DBPs are formed with chlorine, chloramine, ozone, chlorine dioxide, UV, or UV/H2O2. • Chlorine reacts with amine and reduced sulfur groups and activated aromatic systems. • Chlorine dioxide and ozone react with electron-rich functional groups. • Potential health effects are noted for some pharmacuetical DBPs when available. - Abstract: Pharmaceuticals are emerging contaminants of concern and are widespread in the environment. While the levels of these substances in finished drinking waters are generally considered too low for human health concern, there are now concerns about their disinfection by-products (DBPs) that can form during drinking water treatment, which in some cases have been proven to be more toxic than the parent compounds. The present manuscript reviews the transformation products of pharmaceuticals generated in water during different disinfection processes, i.e. chlorination, ozonation, chloramination, chlorine dioxide, UV, and UV/hydrogen peroxide, and the main reaction pathways taking place. Most of the findings considered for this review come from controlled laboratory studies involving reactions of pharmaceuticals with these oxidants used in drinking water treatment

  1. Preparation of 131I-epidepride and biodistribution study in SD rats

    International Nuclear Information System (INIS)

    The purpose is to study the preparation and biodistribution in animals of dopamine D2 receptor ligand 131I-epidepride. Epidepride was 131I radioiodinated with hydroperoxide or chloramine-T method. The purity and stability of 131I-epidepride were studied by HPLC and TLC, the dynamic distribution in brain and critical organs of SD rats were studied. The radiolabelling yields of 131I-epidepride were 97.4% and 52.9% respectively. With no more purification, the hydroperoxide method is better than the chloramine-T method. After 4 hours in room temperature, the radiochemical purity of 131I-epidepride was still over 90%. The striatum uptake was good, the striatum/cerebellum ratio reached 237:1 at 320 min. Among the critical organs, lung had the first and the highest uptake. All organs had quick clearance (T1/2131I-epidepride has a high striatum uptake and a high striatum/cerebellum ratio. 131I-epidepride is a good dopamine D2 receptor agent

  2. Optimization of the preparation conditions of radioiodoepidepride. A dopamine D2receptor antagonist radioligand

    International Nuclear Information System (INIS)

    [125I]iodepidepride, (s)-(-)-[(1-ethyl-2-pyrrolidinyl)methyl]-5-[125I]-iodo-2,3- dimethoxybenzamide is the iodine substituted analogue of isoremoxipride, both of which are very potent dopamine D2-antagonists. Epidepride was radioiodinated using different oxidizing agents such as chloramine-T, iodogen, iodogen glass frit and hydrogen peroxide. Chloramine-T is a powerful oxidizing agent compared to both iodogen and hydrogen peroxide so that the side products, especially the chlorinated epidepride, decreases the radiochemical yield. This chlorinated epidepride is minimized in the case of iodogen and iodogen glass frit and are not observed in case of the non-chlorinated oxidizing agent hydrogen peroxide. TLC and HPLC were used to analyze the reaction components and to estimate both the radiochemical yield and purity. The reaction parameters such as reaction time, pH, epidepride and oxidizing agent concentrations and the stabilty of the final product were studied to optimize the radiochemical yield and purity. The optimized radiochemical yield was about 90% and the radiochemical purity of the final product was 99.9%. (author)

  3. Using digital flow cytometry to assess the degradation of three cyanobacteria species after oxidation processes.

    Science.gov (United States)

    Wert, Eric C; Dong, Mei Mei; Rosario-Ortiz, Fernando L

    2013-07-01

    Depending on drinking water treatment conditions, oxidation processes may result in the degradation of cyanobacteria cells causing the release of toxic metabolites (microcystin), odorous metabolites (MIB, geosmin), or disinfection byproduct precursors. In this study, a digital flow cytometer (FlowCAM(®)) in combination with chlorophyll-a analysis was used to evaluate the ability of ozone, chlorine, chlorine dioxide, and chloramine to damage or lyse cyanobacteria cells added to Colorado River water. Microcystis aeruginosa (MA), Oscillatoria sp. (OSC) and Lyngbya sp. (LYN) were selected for the study due to their occurrence in surface water supplies, metabolite production, and morphology. Results showed that cell damage was observed without complete lysis or fragmentation of the cell membrane under many of the conditions tested. During ozone and chlorine experiments, the unicellular MA was more susceptible to oxidation than the filamentous OSC and LYN. Rate constants were developed based on the loss of chlorophyll-a and oxidant exposure, which showed the oxidants degraded MA, OSC, and LYN according to the order of ozone > chlorine ~ chlorine dioxide > chloramine. Digital and binary images taken by the digital flow cytometer provided qualitative insight regarding cell damage. When applying this information, drinking water utilities can better understand the risk of cell damage or lysis during oxidation processes. PMID:23726712

  4. Studies on human proinsulin.C-peptide radioimmunoassay method

    International Nuclear Information System (INIS)

    125I-labelled human.C-peptide was prepared by the chloramin T method, the enzymic method and the active ester method, respectively. Using respective 125I-labelled human.C-peptides in human proinsulin.C-peptide RIA, we compared the binding (B0/T %) to antibody, displacement by standard human.C-peptide, recovery, and stability. The usable 125I-labelled antigen for human proinsulin.C-peptide RIA could be prepared by the chloramin T method and the enzymic method which labelled 125I to tyrosyl human proinsulin connecting peptide, and by an active ester method which conjugates 125I-labelled active ester to human proinsulin connecting peptide. No differences among those 125I-labelled antigens were observed in displacement (B/B0 %) by standard human.C-peptide or the recovery test. In the case of constant preparation of 125I-labelled antigen for RIA, the enzymic method was the best from the viewpoint that reaction ratio is stable and the stability of B0/T % was good. (auth.)

  5. Occurrence of nitrifying bacteria and nitrification in Finnish drinking water distribution systems.

    Science.gov (United States)

    Lipponen, Mari T T; Suutari, Merja H; Martikainen, Pertti J

    2002-10-01

    Microbiological nitrification process may lead to chemical, microbiological and technical problems in drinking water distribution systems. Nitrification activity is regulated by several physical, and chemical, and operational factors. However, the factors affecting nitrification in the distribution systems in boreal region, having its specific environmental characteristics, are poorly known. We studied the occurrence and activity of nitrifying bacteria in 15 drinking water networks distributing water with very different origin and treatment practices. The waters included chloraminated surface water, chlorinated surface water, and non-disinfected groundwater. The networks were located in eight towns in different parts of Finland. Our results showed that nitrifying bacteria are common in boreal drinking water distribution systems despite their low temperature. Surprisingly high numbers and activities of nitrifiers were detected in pipeline sediment samples. The numbers of ammonia-oxidizing bacteria and their oxidation potentials were highest in chloraminated drinking water delivering networks, whereas the nitrite-oxidizing bacteria were present in the greatest numbers in those networks that used non-disinfected groundwater. The occurrence of nitrifying bacteria in drinking water samples correlated positively with the numbers of heterotrophic bacteria and turbidity, and negatively with the content of total chlorine. Although nitrifying bacteria grew well in drinking water distribution systems, the problems with nitrite accumulation are rare in Finland. PMID:12420937

  6. Effect of Taurine on Acinar Cell Apoptosis and Pancreatic Fibrosis in Dibutyltin Dichloride-induced Chronic Pancreatitis

    Directory of Open Access Journals (Sweden)

    Sawa,Kiminari

    2012-08-01

    Full Text Available The relationship between pancreatic fibrosis and apoptosis of pancreatic acinar cells has not been fully elucidated. We reported that taurine had an anti-fibrotic effect in a dibutyltin dichloride (DBTC-chronic pancreatitis model. However, the effect of taurine on apoptosis of pancreatic acinar cells is still unclear. Therefore, we examined apoptosis in DBTC-chronic pancreatitis and in the AR42J pancreatic acinar cell line with/without taurine. Pancreatic fibrosis was induced by a single administration of DBTC. Rats were fed a taurine-containing diet or a normal diet and were sacrificed at day 5. The AR42J pancreatic acinar cell line was incubated with/without DBTC with taurine chloramines. Apoptosis was determined by using terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick end labeling (TUNEL assay. The expression of Bad and Bcl-2 proteins in the AR42J cells lysates was detected by Western blot analysis. The apoptotic index of pancreatic acinar cells in DBTC-administered rats was significantly increased. Taurine treatment inhibited pancreatic fibrosis and apoptosis of acinar cells induced by DBTC. The number of TUNEL-positive cells in the AR42J pancreatic acinar cell lines was significantly increased by the addition of DBTC. Incubation with taurine chloramines ameliorated these changes. In conclusion, taurine inhibits apoptosis of pancreatic acinar cells and pancreatitis in experimental chronic pancreatitis.

  7. Simultaneous Control of Microorganisms and Disinfection By-products by Sequential Chlorination

    Institute of Scientific and Technical Information of China (English)

    CHAO CHEN; XIAO-JIAN ZHANG; WEN-JIE HE; HONG-DA HAN

    2007-01-01

    Objective To introduce a new sequential chlorination disinfection process in which short-term free chlorine and chloramine are sequentially added. Methods Pilot tests of this sequential chlorination were carried out in a drinking water plant. Results The sequential chlorination disinfection process had the same or better efficiency on microbe (including virus)inactivation compared with the free chlorine disinfection process. There seemed to be some synergetic disinfection effect between free chlorine and monochloramine because they attacked different targets. The sequential chlorination disinfection process resulted in 35.7%-77.0% TTHM formation and 36.6%-54.8% THAA5 formation less than the free chlorination process.The poorer the water quality was, the more advantage the sequential chlorination disinfection had over the free chlorination.Conclusion This process takes advantages of free chlorine's quick inactivation of microorganisms and chloramine's low disinfection by-product (DBP) yield and long-term residual effect, allowing simultaneous control of microbes and DBPs in an effective and economic way.

  8. Continuous formation of N-chloro-N,N-dialkylamine solutions in well-mixed meso-scale flow reactors.

    Science.gov (United States)

    Blacker, A John; Jolley, Katherine E

    2015-01-01

    The continuous flow synthesis of a range of organic solutions of N,N-dialkyl-N-chloramines is described using either a bespoke meso-scale tubular reactor with static mixers or a continuous stirred tank reactor. Both reactors promote the efficient mixing of a biphasic solution of N,N-dialkylamine in organic solvent, and aqueous sodium hypochlorite to achieve near quantitative conversions, in 72-100% in situ yields, and useful productivities of around 0.05 mol/h with residence times from 3 to 20 minutes. Initial calorimetric studies have been carried out to inform on reaction exotherms, rates and safe operation. Amines which partition mainly in the organic phase require longer reaction times, provided by the CSTR, to compensate for low mass transfer rates in the biphasic system. The green metrics of the reaction have been assessed and compared to existing procedures and have shown the continuous process is improved over previous procedures. The organic solutions of N,N-dialkyl-N-chloramines produced continuously will enable their use in tandem flow reactions with a range of nucleophilic substrates. PMID:26734089

  9. Free radical reactions of monochloramine and hydroxylamine in aqueous solution

    International Nuclear Information System (INIS)

    The use of Advanced Oxidation Technologies to destroy organic contaminants in drinking water may be impacted by the presence of disinfection chemicals such as monochloramine (NH2Cl). To allow a quantitative evaluation of the effect of NH2Cl on the destruction of organics in water rate constants for its reaction with the hydrated electron, the hydroxyl radical and the hydrogen atom were determined in this study. The corresponding values of (2.2±0.2)x1010, (2.8±0.2)x109, and (1.2±0.1)x109 M-1 s-1, respectively, were incorporated into a kinetic computer model whose predictions were in good agreement with experimental chloramine removal under large scale, steady-state electron-beam irradiation conditions. Rate constants were also determined for the reaction of the hydroxyl radical and hydrogen atom with the chloramine hydration product hydroxylamine to supplement established literature data. Hydroxyl radical rate constants for the basic (NH2OH) and acidic (NH3OH+) forms were determined as (8.5±0.4)x109 and ≤5x107 M-1 s-1, respectively, while for hydrogen atom reaction, corresponding rate constants of (4.5±0.1)x107 and (3.6±1.5)x105 M-1 s-1 were found

  10. The In vitro Inhibitory Effects of Some Disinfectants on Enzyme Activity of Carbonic Anhydrase from Rainbow Trout (Oncorhynchus Mykiss Gills

    Directory of Open Access Journals (Sweden)

    ??kriye Aras Hisar

    2005-01-01

    Full Text Available Traditional treatments of parasitic and bacterial disease in aquaculture are based on chemotherapeutic compounds. Although, a lot of compounds are used on fish treatment, their undesirable effects are not known in detail. In this study, the effects of some disinfectants - malachite green, methylene blue, potassium permanganate, chloramine-T, copper sulphate and formalin - on Rainbow Trout (RT gill Carbonic Anhydrase (CA which plays a key role in gas exchange, acid-base balance, osmoregulation and ionoregulation were investigated in vitro. For this purpose, CA was purified from RT gills by using sepharose-4$-L tyrosine-sulfanylamide affinity gel chromatography method at initial. CA enzyme with 55.56 (EU/mg proteins specific activity was purified with a yield of 40 % and 104.8-fold finally. I (inhibition values of malachite green, 50 methylene blue, potassium permanganate, chloramine-T and copper sulphate were determined as 0.05 mM, 0.023 mM, 0.15 mM, 0.32 mM and 5.39nM by means of activity % [disinfectant] graphs, respectively. In conclusion our data showed that all the disinfectants except formalin had the in vitro inhibitory effects on the rainbow trout gill CA enzyme whose inhibition could be hazardous to physiological functions such as osmoregulation and acid-base balance in fish.

  11. Study on novel peptide probe 131I-RRL for tumor molecular imaging

    International Nuclear Information System (INIS)

    To study the potential application value of Ary-Ary-Leu(RRL) specially combined with tumor derived endothelial cells in tumor molecular imaging for melanoma bearing mice, a novel peptide RRL was designed and labeled with 131I by chloramine-T method, and mice bearing melanoma tumor were injected 131I-RRL to imaging. The labeling results showed that the optimized condition were following: 50 μg RRL, 10 μL (74 MBq) Na 131I, 90 μg chloramine-T, total reaction volume 100 μL, and reaction time 3 min, the labeling yield was over 69%. The labeling compound was purified by Sephadex G25, its radiochemical purity was > 95%. In vitro binding experiments, FITC-RRL was mainly combine with tumor cells and tumor angiogenesis endothelial cells, and in the SPECT imaging, 131I-RRL peptide could successfully image the tumor in nude mice bearing melanoma tumor for 24 h after injection. The results indicated that small molecular peptide RRL was a promising carrier for tumor molecular imaging and radioimmunotherapy. (authors)

  12. Radioiodine labelling of insulin using dimethylsulfoxide as a labelling-aid

    International Nuclear Information System (INIS)

    Using dimethylsulfoxide (DMSO) as a labelling aid, insulin 126I of radioimmunoassay use has been effectively prepared. A small amount of DMSO was added to usual labelling mixture and the reaction time was controlled. The labelled insulin obtained in such a way showed improved bindabilities to the antibody and thus expressed larger dose-gradients in the plots of standard dose-response curves even though the labelling rate was decreased to some extent. However, by extending the reaction time to about 1 min, average labelling yield of 30% could be obtained. The average increase of bindability (B/F) in definite antiserum dilution was 2.5 comparing with 1.5 obtained in the absence of DMSO. Thus, the net bindability increase was 70% of those obtained in the absence of DMSO. By means of NMR spectrometry, it has been confirmed that the DMSO in the labelling mixture is converted to dimethylsulfone by chloramine-T. The results, generally agreed with the Stagg's postulation, were discussed in view of a competitive oxidation of DMSO with disulfide linkages of the insulin molecule by the chloramine-T. (author)

  13. Radioiodination and biological evaluation of levalbuterol as a new selective radiotracer. A β{sub 2}-adrenoceptor agonist

    Energy Technology Data Exchange (ETDEWEB)

    Sanad, Mahmoud Hamdi; Abelrahman, Mohamed Abdelmotelb; Marzook, Fawzy Mohamed Abdelmaged [Atomic Energy Authority, Cairo (Egypt). Radioisotopes Production and Radioactive Sources Div.

    2016-08-01

    Levalbuterol was successfully radiolabeled with iodine using chloramine-T as an oxidizing agent via an electrophilic substitution reaction. The reaction parameters that affecting the labeling yield such as levalbuterol concentration, chloramine-T concentration, pH of the reaction medium and reaction time were studied in details. The radiochemical yield was 97.5 ± 0.5% and the radioiodinated compound was separated by HPLC. In vitro studies showed that the iodinated levalbuterol was stable for up to 24 h. The biodistribution in experimental animals showed that the lung uptake was 68.18 ± 0.17% at 5 min post injection which decreased with time until reached to 18.7 ± 0.12% at 2 h which was higher than other recent developed radiopharmaceuticals for lung imaging. The clearance pathways from the mice appear to proceed via both hepatobiliary and renal pathways. Predosing the mice with cold levalbuterol reduced the lung uptake to 20 ± 1.3% and further confirms the high specificity and selectivity of {sup 125}I-levalbuterol for the lung.

  14. Labeling Lanreotide with 125I and 188Re

    International Nuclear Information System (INIS)

    Lanreotide is a new somatostatin analogue. It can bind to human somatostatin receptor (hSSTR) subtype 2 through 5 with high affinity and to hSSTR subtype I with low affinity. We investigate labeling condition, quality control and stability in vitro of 125I-Lanreotide and 188Re-lanreotide respectively. (A) Lanreotide is labeled with 125I using Chloramine T. The effect of reaction condition (such as reaction time, pH value, Lanreotide amount, quantity of Chloramine T and reaction volume) on labeling yield is investigated in detail. (B) The labeling yield and radiochemical purity (RP) is measured with paper chromatography (PC) and Sep-Pak C18 Cartridge. (C) The stability of 125I-Lanreotide in vitro is investigated by labeling compound incubating for 48 hours at 37 deg C in the 0.9% sodium chloride solution and RP is tested by PC at specific time intervals. (D) Lanreotide is labeled directly with 188Re via the mixture of citrate and tartate using stannous chloride as reduced agent. The influence of reaction conditions such as pH, temperature, amount of stannous chloride, amount of Lanreotide and reaction time on labeling yield is investigated in detail. At the time, the stability in vitro quality control and animal test are evaluated

  15. Continuous formation of N-chloro-N,N-dialkylamine solutions in well-mixed meso-scale flow reactors

    Directory of Open Access Journals (Sweden)

    A. John Blacker

    2015-12-01

    Full Text Available The continuous flow synthesis of a range of organic solutions of N,N-dialkyl-N-chloramines is described using either a bespoke meso-scale tubular reactor with static mixers or a continuous stirred tank reactor. Both reactors promote the efficient mixing of a biphasic solution of N,N-dialkylamine in organic solvent, and aqueous sodium hypochlorite to achieve near quantitative conversions, in 72–100% in situ yields, and useful productivities of around 0.05 mol/h with residence times from 3 to 20 minutes. Initial calorimetric studies have been carried out to inform on reaction exotherms, rates and safe operation. Amines which partition mainly in the organic phase require longer reaction times, provided by the CSTR, to compensate for low mass transfer rates in the biphasic system. The green metrics of the reaction have been assessed and compared to existing procedures and have shown the continuous process is improved over previous procedures. The organic solutions of N,N-dialkyl-N-chloramines produced continuously will enable their use in tandem flow reactions with a range of nucleophilic substrates.

  16. Enhanced formation of disinfection byproducts in shale gas wastewater-impacted drinking water supplies.

    Science.gov (United States)

    Parker, Kimberly M; Zeng, Teng; Harkness, Jennifer; Vengosh, Avner; Mitch, William A

    2014-10-01

    The disposal and leaks of hydraulic fracturing wastewater (HFW) to the environment pose human health risks. Since HFW is typically characterized by elevated salinity, concerns have been raised whether the high bromide and iodide in HFW may promote the formation of disinfection byproducts (DBPs) and alter their speciation to more toxic brominated and iodinated analogues. This study evaluated the minimum volume percentage of two Marcellus Shale and one Fayetteville Shale HFWs diluted by fresh water collected from the Ohio and Allegheny Rivers that would generate and/or alter the formation and speciation of DBPs following chlorination, chloramination, and ozonation treatments of the blended solutions. During chlorination, dilutions as low as 0.01% HFW altered the speciation toward formation of brominated and iodinated trihalomethanes (THMs) and brominated haloacetonitriles (HANs), and dilutions as low as 0.03% increased the overall formation of both compound classes. The increase in bromide concentration associated with 0.01-0.03% contribution of Marcellus HFW (a range of 70-200 μg/L for HFW with bromide = 600 mg/L) mimics the increased bromide levels observed in western Pennsylvanian surface waters following the Marcellus Shale gas production boom. Chloramination reduced HAN and regulated THM formation; however, iodinated trihalomethane formation was observed at lower pH. For municipal wastewater-impacted river water, the presence of 0.1% HFW increased the formation of N-nitrosodimethylamine (NDMA) during chloramination, particularly for the high iodide (54 ppm) Fayetteville Shale HFW. Finally, ozonation of 0.01-0.03% HFW-impacted river water resulted in significant increases in bromate formation. The results suggest that total elimination of HFW discharge and/or installation of halide-specific removal techniques in centralized brine treatment facilities may be a better strategy to mitigate impacts on downstream drinking water treatment plants than altering

  17. Full-scale studies of factors related to coliform regrowth in drinking water.

    Science.gov (United States)

    LeChevallier, M W; Welch, N J; Smith, D B

    1996-07-01

    An 18-month survey of 31 water systems in North America was conducted to determine the factors that contribute to the occurrence of coliform bacteria in drinking water. The survey included analysis of assimilable organic carbon (AOC), coliforms, disinfectant residuals, and operational parameters. Coliform bacteria were detected in 27.8% of the 2-week sampling periods and were associated with the following factors: filtration, temperature, disinfectant type and disinfectant level, AOC level, corrosion control, and operational characteristics. Four systems in the study that used unfiltered surface water accounted for 26.6% of the total number of bacterial samples collected but 64.3% (1,013 of 1,576) of the positive coliform samples. The occurrence of coliform bacteria was significantly higher when water temperatures were > 15 degrees C. For filtered systems that used free chlorine, 0.97% of 33,196 samples contained coliform bacteria, while 0.51% of 35,159 samples from chloraminated systems contained coliform bacteria. The average density of coliform bacteria was 35 times higher in free-chlorinated systems than in chloraminated water (0.60 CFU/100 ml for free-chlorinated water compared with 0.017 CFU/100 ml for chloraminated water). Systems that maintained dead-end free chlorine levels of systems that maintained higher disinfectant residuals. Free-chlorinated systems with AOC levels greater than 100 micrograms/liter had 82% more coliform-positive samples and 19 times higher coliform levels than free-chlorinated systems with average AOC levels less than 99 micrograms/liter. Systems that maintained a phosphate-based corrosion inhibitor and limited the amount of unlined cast iron pipe had fewer coliform bacteria. Several operational characteristics of the treatment process or the distribution system were also associated with increased rates of coliform occurrence. The study concludes that the occurrence of coliform bacteria within a distribution system is dependent upon

  18. Labelling and quality control of somatostatin analogues with 99mTc

    International Nuclear Information System (INIS)

    Techniques and methodologies for labelling peptides with 99mTc and methods for their purification, chemical, radiochemical and biological controls were evaluated. With the purpose of gaining experience, labelling with 125I was also studied. RC-160 was labelled with 125I using iodogen as well as chloramine-T method. Higher yields were obtained with chloramine-T method (60%), rendering 125I-peptide with 98% of radiochemical purity, with specific activity of 240 μCi/μg - 274 μCi/μg. The product was stable for five weeks (at -20 deg. C). For somatostatin receptors studies rat brain cortex membrane was prepared. Maximum binding capacity was 24.7% and Kaff for the binding of RC-160 to receptor was estimated as 2.0x1010 M-1. Other peptides as β-(2-Naphthyl)-DAla-Cys-Tyr-DTrp-Lys-Val-Cys-Thr amide (N-9642, Σ) and mouse epidermal growth factor (mEGF) were also labelled by means of limiting chloramine-T method. In case of mEGF the availability of membrane receptors allowed us to experiment in mice as well as in vitro. The reaction yields were up to 60% and 70% respectively. Biodistribution of 125I-mEGF in a mouse with adenoma demonstrated preferential uptake in tumour (21,7% injected dose). The radioimmunoassay system gave 39% maximum binding (MB) and 50% displacement (ED50) for 10 ng/mL unlabelled mEGF. Direct method and BFC's for labelling peptides with 99mTc were investigated and purification and quality controls studies were performed by TLC, HPLC (UV and gamma detection). RC-160 was labelled by a direct method using sodium dithionite as reducing agent with radiochemical purity >95%. The product was stable up to six hours (at RT). Considerable adsorption problems were observed. Biological behavior was in accordance with the compounds' lipophilicity. The synthesis of TOC conjugates with HYNIC as BFC was done with 45%±5% (n=3) yield. Labelling of HYNIC-TOC with tricine as co-ligand was conducted with up to 90% yield. Studies of RC-160 labelling using 99m

  19. Plasma levels of vitellogenin in Chrysemys picta during the annual gonadal cycle: Measurement by specific radioimmunoassay

    International Nuclear Information System (INIS)

    A RIA for turtle (Chrysemys picta) vitellogenin is described. After dimethylformamide precipitation of vitellogenin from the plasma of estrogen-treated female turtles, antibodies were developed in rabbits. The dimethylformamide precipitate was further purified by o-triethylaminoethyl cellulose column chromatography; the vitellogenin component eluted as a single peak. This material was used for iodination by a mild chloramine method. Antibodies to turtle vitellogenin did not cross-react with plasma from male turtles or vitellogenic females of other vertebrate groups, including lizards and snakes. Limited cross-reactivity exists among the chelonians, however. Using a 1:5000 dilution of antiserum, the limit of detection was 15 ng, and the midrange was 320 +- 45 ng. For an antiserum dilution of 1:1000, these figures were 30 and 600 +- 37 ng, respectively. Using this assay, the seasonal pattern of plasma vitellogenin in the turtle has been described, and preliminary studies on in vitro hepatic vitellogenesis have been performed

  20. Separation of sup 125 I-labelled triiodothyronine (T3) and thyroxine (T4) on a sephadex G25 column with the elution of sodium hydroxide buffer

    International Nuclear Information System (INIS)

    Radioiodine labelled triiodothyronine and thyroxine hormones were obtained by iodinating T3 with NaI sup 125 by using chloramine-T method. sup 125 I-T3 and sup 125 I- T4 separated on a sephadex gel G25 filtration column eluted with 0.015 M NaOH, pH 12.0 or 0.05M NaHCO sub 3, pH 9.0 buffer. The percentage of radioiodine incorporated to T3 was 40-60% and to T4 between 25-40% The separation of sup 125 I-T3 and sup 125 I-T4 were completed within 5 hours following elution with NaOH buffer whereas the separation using carbonate buffer required about 12 hours. The radiolabelled T3 and T4 eluted with NaOH buffer bound to the anti T3 and anti T4 antibodies

  1. Homologous radioimmunoassay of human prolactin

    International Nuclear Information System (INIS)

    Gelfiltration on Sephadex G-75 showed a heterogenity of prolactin in serum of patients with prolactinoma and in culture medium of a prolactinoma. Serum of patients with prolactinoma and culture medium of a prolactinoma were examined as possible sources of prolactin by gel filtration and ion exchange chromatography. Polyacrylamide electrophoresis revealed both preparations as contaminated by other proteins. Nevertheless prolactin isolated form culture medium of a prolactinoma is good enough as a tracer in our radioimmunoassay because contaminating proteins in this preparation do not inferfere in our system. An hPRL antiserum created in a rabbit against a crude fraction of human serum of a patient with prolactinoma was tested by titration, saturation studies, and ion exchange chromatography. In comparison with lactoperoxidase-iodinated prolactin Chloramine T iodinated prolactin showed higher loss of immunochemical properity, however higher specific activity. Specifity and precision in our radioimmunoassay system were described and the conditions of optimal sensitivity in our assay were evaluated. (orig.)

  2. Rapid method for the preparation of 125I-labelled human growth hormone for receptor studies, using reverse-phase high performance liquid chromatography

    International Nuclear Information System (INIS)

    Human growth hormone was labelled with 125 Iodine by the stoichiometric modification of the chloramine-T method to a specific activity of 50-80 microCi/microgram, and the iodinated mixture was purified by reverse-phase high performance liquid chromatography using a C18 column (SynChropak RP-P) and a linear gradient. Compared with the usual Sephadex G-100 chromatography, HPLC gave a much better separation, with a higher yield and a considerably reduced analysis time (30 min vs 5 h). The [125I]-labelled preparation had normal binding to IM-9 lymphocyte receptors. The maximum bindability of the HPLC-purified preparation approximated 90%, which is the best value so far reported for human growth hormone. It is concluded that HPLC is a fast, convenient and reproducible method for obtaining an improved [125I]-labelled human growth hormone for receptor studies

  3. Development of the kits for RIA simultaneous determination of polypeptide hormones

    International Nuclear Information System (INIS)

    A simple and universal modification of chloramine T technique has been developed for the radioactive iodination of several polypeptide hormones such as insulin, human growth hormone (HGH), human TSH, synthetic human gastrin and beta-endorphine. The prepared products proved to have good immunoreactivity suitable for RIA purposes. The technique is inexpensive and quick. A new procedure has also been worked out utilizing horse myeloperoxidase in solid state as catalyser. The hormones iodinated with this technique show better parameters (e.g. longer stability, better binding to antibody, more favourable adsorption on dextran-coated charcoal); however the specific activities achieved were lower. The possibilities of simultaneous measurement of insulin and HGH have been studied. In this connection, a comparatively simple method for the determination of the endogenous anti-insulin antibodies was developed and used for the control of patients with diabetes and for the checking of new insulin preparations. However, the technique requires relatively sophisticated equipment and computerized calculations

  4. Immunoradiometric assay for human thyrotropin (h-TSH) monoclonal antibody radioiodination

    International Nuclear Information System (INIS)

    125 I labelled monoclonal antibody (MAb) TSH was prepared to be used for determination of h-TSH in clinical assay laboratory by an immunoradiometric assay (IRMA). Determination of h-TSH by this method helps to confirm the diagnosis of thyroid toxic adenoma or hypophysis tumours. In this study, the preparation and characterization of this reagent is described. The radioiodination of monoclonal antibody TSH was carried out by chloramine T method and the reaction mixture was purified by chromatography on a Sephadex G150 column. The reaction yields were around 80 % and 125 I - MAb anti h-TSH has the following characteristics: specific activity = 20-24 μCi μg and radioactive concentration ≅ 25 μCi/ml. Also, the immunological properties of the tracer were verified. 125 I labelled monoclonal antibody anti h-TSH will be used as reagent for direct immunometric assay of h-TSH. (authors)

  5. Synthesis of 131I labeled diiodothyronine (131I-T2)

    International Nuclear Information System (INIS)

    Objective: To synthesise 131I-T2 as the basis for future synthesis of 131I-T2S with sulfation. Methods: Firstly 3-T1 was radiolabeled with 131I with chloramine-T(Ch-T) labeling method. Then gel column chromatography and paper chromatography were used for separation and purification. Measurement of the labeling efficiency, radiochemical purity,stability of labeled compound, and identification of the product of immune activity were carried out. Results: The radiolabeling yield of the labeled compound produced with the modified Ch-T method was about 65.1%±4.5% (n=5) and the radiochemical purity was about 96.5%±1.1% (n=5). After 10d storage at -20 degree C, the radiochemical purity of the product still remained above 90%. Conclusion: High rate of labeling efficiency and good stability could be obtained with Ch-T labeling method. (authors)

  6. Physico-chemical technologies for nitrogen removal from wastewaters: a review

    Directory of Open Access Journals (Sweden)

    Andrea G. Capodaglio

    2015-07-01

    Full Text Available The paper examines the main physico-chemical processes for nitrogen removal from wastewaters, considering both those that have been long known and still widely applied at the industrial scale, and those that are still at the research level. Special attention is paid to the latest technological developments, as well as to operational problems and fields of application. The processes considered are briefly summarized as follows: ammonia air and steam stripping; ammonia vacuum distillation; ammonia precipitation as struvite; ammonia and nitrate removal by selected ion exchange; breakpoint chlorination; chloramine removal by selected activated carbon; ammonia adsorption on charcoal; chemical reduction of nitrate; advanced oxidation processes to convert ammonia and organic-N into nitrogen gas or nitrate. Special attention is given to advanced oxidation processes, as great research efforts are currently addressed to their implementation. These specifically include ozonation, peroxon oxidation, catalytic wet air oxidation, photo-catalytic oxidation and electrochemical oxidation.

  7. Feasibility of iodine-125 labeled anti-human hemoglobin antibody in the detection of bleeding sites from the large bowel-A preliminary study

    International Nuclear Information System (INIS)

    A monoclonal anti-human hemoglobin antibody that cross-reacts with mouse hemoglobin was labeled with Iodine-125 through the Chloramine-T method. The labeled antibody was used in an attempt to recognize bleeding sites from the large bowel in a mouse model, through a non-invasive enema-like study. In vitro experiments after double column chromatography of the labeled antibody and 10% trichloroacetic acid conjugation revealed that about 80% of the radioactivity was incorporated into protein. Inhibition assay containing could (non-radiolabeled) antibody showed that Iodine-125 radiolabeled antibody preserved its immunoreactivity. Autoradiographs exquisitely demonstrated accumulation of isotope in the corresponding intestinal bleeding areas. These findings suggest that this method can be useful for scintigraphic localization of bleeding sites in the large bowel. (author)

  8. UP-REGULATION OF HEPATIC RECEPTOR FOR GROWTH HORMONE IN THE FLOUNDER (PARALICHTHYS OLIVACEUS) AFTER ORAL ADMINISTRATION WITH EXOGENOUS GH

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The iodination efficiency of salmon GH(Sgh) was 38.82%,using a modification of the chloramine-T method. The specific activity of the 125I-Sgh was about 40 μCi/μg protein. The results of binding assay showed a single class of high affinity and low-capacity binding site in flounder liver. Long-term administration with exogenous GH can induce the up-regulation of hepatic GH receptor in total binding capacity though there was no significant difference of association constant among any groups. Considering that there was no significant difference in capacity of free binding sites of livers from control and experimental fish, this result also indicated that the liver from experimental fish, compared to that from control fish, had more occupied binding sites.

  9. UP-REGULATION OF HEPATIC RECEPTOR FOR GROWTH HORMONE IN THE FLOUNDER (PARALICHTHYS OLIVACEUS) AFTER ORAL ADMINISTRATION WITH EXOGENOUS GH

    Institute of Scientific and Technical Information of China (English)

    刘宗柱; 王金宝; 徐永立; 王勇; 张培军

    2001-01-01

    The iodination efficiency of salmon GH (sGH) was 38.82%,using a modification of the chloramine-T method. The specific activity of the 125I-sGH was about 40 μCi/μg protein. The results of binding assay showed a single class of high affinity and low-capacity binding site in flounder liver. Long-term administration with exogenous GH can induce the up-regulation of hepatic GH receptor in total binding capacity though there was no significant difference of association constant among any groups. Con-sidering that there was no significant difference in capacity of free binding sites of livers from control and experimental fish, this result also indicated that the liver from experimental fish, compared to that from control fish, had more occupied binding sites.

  10. Direct astatination of a tumour-binding protein, human epidermal growth factor, using nido-carborane as a prosthetic group

    International Nuclear Information System (INIS)

    A method for direct astatine labeling of proteins has been investigated. Binding sites for astatine were created by coupling of a nido-carborane derivative to a protein, the human epidermal growth factor (hEGF), using two different conjugation methods - by glutaraldehyde cross-linking or by introduction of sulfohydryl groups by Traut's reagent with subsequent linking of ANC-1 with m-maleimidobenzoyl-N-hydroxysulfosuccinimide ester. The conjugates were astatinated using the Chloramine-T method in high yield. The best labeling was obtained by the glutaraldehyde conjugate with an average yield of 68 ± 9%. In vitro stability tests indicated that the glutaraldehyde conjugated label was as stable as hEGF labeled with astatobenzoate. (author)

  11. Preparation of [123I]- and [125I]epidepride: a dopamine D-2 receptor antagonist radioligand

    International Nuclear Information System (INIS)

    (S)-(-)-N-[(1-ethyl-2-pyrrolidinyl)methyl]-5-[123I] iodo-2,3-dimethoxybenzamide (TDP 517) (proposed generic name, [123I]epidepride) is the iodine-123 substituted analogue of isoremoxipride (FLB 457), both of which are very potent dopamine D-2 antagonists (epidepride KD 0.024 nM). [123I] Epidepride was radioiodinated in 60-70% radiochemical yields in 35 min from the corresponding 5-(tributyltin) derivative using Na123I with a specific radioactivity of 3000 Ci/mmol, and oxidized in situ with chloramine-T. The aryltin precursor was prepared from non-labelled epidepride by palladium-catalyzed stannylation using bis(tri-n-butyltin) in triethylamine. Alternatively, using no carrier-added Na125I as the radioisotope, [125I] epidepride at 2000 Ci/mmol specific radioactivity was prepared in 86% radiochemical yield and 99% radiochemical purity after purification by reverse phase HPLC in ethanolic phosphate buffer. (author)

  12. Recent advances in drinking water disinfection: successes and challenges.

    Science.gov (United States)

    Ngwenya, Nonhlanhla; Ncube, Esper J; Parsons, James

    2013-01-01

    , it is recommended that water disinfection should never be compromised by attempting to control DBPs. The reason for this is that the risks of human illness and death from pathogens in drinking water are much greater than the risks from exposure to disinfectants and disinfection by-products. Nevertheless, if DBP levels exceed regulatory limits, strategies should focus on eliminating organic impurities that foster their formation, without compromising disinfection. As alternatives to chlorine, disinfectants such as chloramines, ozone, chlorine dioxide, and UV disinfection are gaining popularity. Chlorine and each of these disinfectants have individual advantage and disadvantage in terms of cost, efficacy-stability, ease of application, and nature of disinfectant by-products (DBPs). Based on efficiency, ozone is the most efficient disinfectant for inactivating bacteria, viruses, and protozoa. In contrast, chloramines are the least efficient and are not recommended for use as primary disinfectants. Chloramines are favored for secondary water disinfection, because they react more slowly than chlorine and are more persistent in distribution systems. In addition, chloramines produce lower DBP levels than does chlorine, although microbial activity in the distribution system may produce nitrate from monochloramine, when it is used as a residual disinfectant, Achieving the required levels of water quality, particularly microbial inactivation levels, while minimizing DBP formation requires the application of proper risk and disinfection management protocols. In addition, the failure of conventional treatment processes to eliminate critical waterborne pathogens in drinking water demand that improved and/or new disinfection technologies be developed. Recent research has disclosed that nanotechnology may offer solutions in this area, through the use of nanosorbents, nanocatalysts, bioactive nanoparticles, nanostructured catalytic membranes, and nanoparticle-enhanced filtration

  13. Transformation of pharmaceuticals during oxidation/disinfection processes in drinking water treatment.

    Science.gov (United States)

    Postigo, Cristina; Richardson, Susan D

    2014-08-30

    Pharmaceuticals are emerging contaminants of concern and are widespread in the environment. While the levels of these substances in finished drinking waters are generally considered too low for human health concern, there are now concerns about their disinfection by-products (DBPs) that can form during drinking water treatment, which in some cases have been proven to be more toxic than the parent compounds. The present manuscript reviews the transformation products of pharmaceuticals generated in water during different disinfection processes, i.e. chlorination, ozonation, chloramination, chlorine dioxide, UV, and UV/hydrogen peroxide, and the main reaction pathways taking place. Most of the findings considered for this review come from controlled laboratory studies involving reactions of pharmaceuticals with these oxidants used in drinking water treatment. PMID:25156529

  14. Development and Optimization of Sepharose Solid Phase Radioimmunoassay for Estimation of Thyroid Stimulating Hormone

    International Nuclear Information System (INIS)

    The aim of the present study was oriented to develop, optimize and validate solid phase radioimmunoassay, through many studies on Sepharose, for estimation of thyroid stimulating hormone in humane serum. Preparation of polyclonal antibodies was carried out in host rabbit animals against TSH antigen followed by partial purification of 1gG. Linkage of antibody 1gG to activated Sepharose CL-4B was carried out after activation of Sepharose with 1,1- carbonyldiimidazole. Labeling of TSH was carried out using chloramine-T as an oxidizing agent and the labeled tracer was purified through PD-10 column. Extensive studies were carried out to obtain the optimum conditions of using solid phase Sepharose to reach higher separation efficiency. The results of validation tests reveal that the local solid phase system is precise and accurate for evaluation of thyroid disorders

  15. development of solid phase anti-T3 and anti-T4 coated beads for detection of T3 and T4 hormones

    International Nuclear Information System (INIS)

    the thyroid secretes two significant hormones thyroxin and triiodothyronine, commonly called T4 and T3, respectively. both of these hormones have profound effect of increasing the metabolic rate of the body. in the present study a radioimmunoassay system was developed to detect T3 and T4 hormones. the solid phase anti-T3 and anti-T4 coated beads was prepared also the radiolabeled T3 and T4 was prepared using diiodothyronine (T2) and I125 with chloramine-T method. the system was developed and characterized according to the terms of accuracy, sensitivity, specificity, cross- reactivity and dilution effect. also the results of patient serum obtained by the developed system were compared with that of commercially used kit. from the obtained results it was found that the prepared system was closely similar to that of commercially used one

  16. Iodination of monoclonal antibodies, proteins and peptide using iodogen

    International Nuclear Information System (INIS)

    The use of the iodinating reagent 1,3,4,6-tetrachloro-3α, 6α-diphenylglycholuril (Iodogen) to label monoclonal antibodies (McAbs). Proteins and peptides was invesrigated with McAbs identified as mouse IgG and IgM, arginine-vasopressin (AVP), glucagon (Glu), human insulin(hI) and albumin(Alb). The labeled products were purified by gel chromatography and their immunoreactivity were detected by RIA or IRMA> Comparison of the Iodogen method with the lactoperoxides and chloramine-T methods showed that the Iodogen method had a number of advantages: 1) technically simpler ; 2) a high labeling efficiency could be obtained; 3) the immunoreactivity of the products was minimally affected; 4) the products were stable for up to 4 months

  17. Standardisation of radioimmunoassay for human insulin employing magnetizable cellulose particles

    International Nuclear Information System (INIS)

    We describe a convenient and flexible solid phase radioimmunoassay for human insulin employing magnetizable cellulose particles. Anti-porcine insulin antibody was covalently linked to magnetizable cellulose particles to form a stable and economical solid phase immunosorbent system. The tracer was prepared by radioiodinating insulin with 125I using Chloramine-T oxidation method. The analytical sensitivity of assay observed was 5.5 μIU/mL. Intra-assay and inter-assay variations were found to be <12 % along with analytical recovery of 93-109 %. The developed assay can be used for the routine analysis of clinical samples. In addition, concentration of the solid phase magnetizable immunosorbent can be easily varied as per the specific requirement for research purposes. (author)

  18. Preparation and Validation of Double Antibody Radioimmunoassay for Thyroglobulin (Tg) using Balb/C Mice as Host Animals

    International Nuclear Information System (INIS)

    The preparation and development of primary reagents of thyroglobulin (Tg) radioimmunoassay technique with low cost is considered to be the main objective of present study. The production of polyclonal antibodies of thyroglobulin was undertaken by immunizing three bulb/C mice intraperitoneal through primary injection and two booster doses. The preparation of 125I-Tg radiotracer was carried out using chloramine-T as oxidizing agent. The preparation of thyroglobulin standards were carried out. Optimization and validation of the assay were studied out. The results obtained provide a highly sensitive, specific and accurate RIA system for thyroglobulin based on liquid phase separation. In conclusion, this assay could be used for diagnosis of thyroid cancer.

  19. Measurement of plasma canine C peptide by radioimmunoassay

    International Nuclear Information System (INIS)

    A sensitive radioimmunoassay for canine C peptide (CCP) was established using synthetic CCP, a specific antiserum, and rabbit anti-guinea pig serum. Radioiodination was performed according to a modified chloramine T method. Tracer preparations have been used for 6 weeks after iodination. The standard curve ranges from 0.028 to 3.0 nmol/l. The intra-assay coefficient of variation (CV) was 3-5% and the inter-assay CV was 6-9% in the optimal range between 0.3 and 0.8 nmol/l. The average recovery of CCP added to plasma samples was 100.6% (n = 9). Canine insulin, porcine proinsulin, bovine proinsulin, and human C peptide exhibited no cross-reactivity. The mean fasting plasma CCP concentration was 0.089 +- 0.021 nmol/l in normal dogs and -0.005 +- 0.007 nmol/l (mean +- SEM) in diabetic dogs, respectively. (author)

  20. Standardization of human thyrotropin radioimmunoassay and its application to the purification of this hormone to the preparation of the assay reagents

    International Nuclear Information System (INIS)

    The various steps that are necessary for setting up the thyrotropin radioimmunoassay are presented below. Radioiodination was carried out through the Chloramine T method and the labeled purification performed on Sephadex G-100. Purification of human thyrotropin from side fractions obtained during the purification of growth hormone was carried out in order to obtain a pure reagent for use in the radioimmunoassay. The employment of the hormone obtained was evaluated as the radioimmunoassay tracer in comparison with that prepared from the hormone received from the NIDDKD, U.S.A. The results indicated that although it was not possible to obtain a hormone with a purity degree adequate to be used as the tracer, enough experience was acquired for the isolation of thyrotropin. (author)

  1. Development of a radioimmunoassay for pig pancreatic kallikrein

    International Nuclear Information System (INIS)

    A radioimmunoassay for the determination of pig pancreatic kallikrein was developed. The chloramine-T method was employed for the labelling of the antigen with 125I. The assay allows the determination of kallikrein in concentrations as low as 0.4 μg/l. Pig urinary and pig submandibular kallikreins are indistinguishable from pig pancreatic kallikrein by the assay. No cross reactivity was observed for bovine trypsin and chymotrypsin, porcine trypsin and kallikreins of guinea pig submandibular glands and guinea pig coagulation glands. Because of the high specificity of the assay, which is not attainable with conventional assays based on the enzymatic activity, the radioimmunoassay is highly suited for investigations into the physiological role and the pharmacological mechanism of action of pig glandular kallikreins. (orig.)

  2. Retention of biological activity following radioiodination of human interleukin 2: comparison with biosynthetically labeled growth factor in receptor binding assays

    International Nuclear Information System (INIS)

    Human interleukin 2 (IL-2) was radioiodinated by a modified form of the chloramine-T reaction. Comparison with biosynthetically radiolabeled IL-2 demonstrated that the iodinated molecule retained similar receptor binding characteristics and proliferation-inducing ability. The iodinated molecule also possessed the distinct advantages of a higher specific radioactivity and a reduced processing time for the assay samples. The majority of the iodine was incorporated at the tyrosine in position 45 of the polypeptide chain. Evidently, this residue is unimportant for the molecule's association with its receptor. The development of active radioiodinated IL-2 should facilitate routine measurement of the high-affinity IL-2 binding sites which mediate the physiological response to this lymphokine. (Auth.)

  3. 3H and 125I radioimmunoassays of haloperidol compared with fluoroimmunoassay involving antibody coupled to magnetizable solid phase

    International Nuclear Information System (INIS)

    Radioimmunoassays for haloperidol are described, involving use of tritium-or 125I-labeled drug or tritium-labeled spiroperidol, and a rabbit antiserum to a drug/bovine serum albumin conjugate. The 125I-labeled drug was prepared by the Chloramine T iodination technique. A fluoroimmunoassay for haloperidol is also described in which the antiserum is coupled to magnetizable solid-phase medium, and fluorescein-labeled haloperidol is used. The assays have acceptable accuracy, precision, and reproducibility, and are specific for haloperidol and similar butyrophenones, with no significant interference from known metabolites and other drugs. Only the radioimmunoassays have sufficient sensitivity to cover the whole range of haloperidol concentrations in serum. The fluoroimmunoassay can be used to monitor high concentrations of haloperidol in 150 μL samples or the complete concentration range of 1-mL serum samples that are extracted and concentrated before assay

  4. 3H and 125I radioimmunoassays of haloperidol compared with fluoroimmunoassay involving antibody coupled to magnetizable solid phase

    International Nuclear Information System (INIS)

    Radioimmunoassays for haloperidol are described, involving use of tritium- or 125I-labeled drug or tritium-labeled spiroperidol, and a rabbit antiserum to a drug/bovine serum albumin conjugate. The 125I-labeled drug was prepared by the Chloramine T iodination technique. A fluoroimmunoassay for haloperidol is also described in which the antiserum is coupled to magnetizable solid-phase medium, and fluorescein-labeled haloperidol is used. The assays have acceptable accuracy, precision, and reproducibility, and are specific for haloperidol and similar butyrophenones, with no significant interference from known metabolites and other drugs. Only the radioimmunoassays have sufficient sensitivity to cover the whole range of haloperidol concentrations in serum. The fluoroimmunoassay can be used to monitor high concentrations of haloperidol in 150-microL samples or the complete concentration range of 1-mL serum samples that are extracted and concentrated before assay

  5. Preparation of Double Antibody Radioimmunoassay for Determination of Alpha fetoprotein as a Tumor Marker using BALB/C Mice as Host Animals

    International Nuclear Information System (INIS)

    The aim of the present work was to prepare liquid phase radioimmunoassay system (RIA) reagents. Development as well as optimization and validation of this RIA system for the measurement of alpha fetoprotein (AFP) in human serum are described. The production of polyclonal antibodies was carried out by immunizing four BALB/C mice subcutaneously. The preparation of 125I-AFP tracer was performed using chloramine-T oxidation method. The preparation of AFP standards was done by diluting cord sera using assay buffer. The results obtained provide a highly sensitive,precise and accurate RIA system of AFP based on liquid phase separation. In conclusion, this assay could be used for the diagnosis and management of patients with certain malignant diseases and in prenatal diagnosis of neural tube defects

  6. Kinetic Model for the Radical Degradation of Tri-Halonitromethane Disinfection Byproducts in Water

    Energy Technology Data Exchange (ETDEWEB)

    Stephen P. Mezyk; Bruce J. Mincher; William J. Cooper; S. Kirkham Cole; Robert V. Fox; Pieror R. Gardinali

    2012-10-01

    The halonitromethanes (HNMs) are byproducts of the ozonation and chlorine/chloramine treatment of drinking waters. Although typically occurring at low concentrations HNMs have high cytotoxicity and mutagenicity, and may therefore represent a significant human health hazard. In this study, we have investigated the radical based mineralization of fully-halogenated HNMs in water using the congeners bromodichloronitromethane and chlorodibromonitromethane. We have combined absolute reaction rate constants for their reactions with the hydroxyl radical and the hydrated electron as measured by electron pulse radiolysis and analytical measurements of stable product concentrations obtained by 60Co steady-state radiolysis with a kinetic computer model that includes water radiolysis reactions and halide/nitrogen oxide radical chemistry to fully elucidate the reaction pathways of these HNMs. These results are compared to our previous similar study of the fully chlorinated HNM chloropicrin. The full optimized computer model, suitable for predicting the behavior of this class of compounds in irradiated drinking water is provided.

  7. Radioiodination of monoclonal antibodies, proteins and peptides for diagnosis and therapy. A review of standardized, reliable and safe procedures for clinical grade levels kBq to GBq in the Goettingen/Marburg experience

    Energy Technology Data Exchange (ETDEWEB)

    Behr, Th.M.; Gotthardt, M.; Behe, M. [Marburg Univ. (Germany). Dept. of Nuclear Medicine; Becker, W. [Goettingen Univ. (Germany). Dept. of Nuclear Medicine

    2002-04-01

    Simple and reliable methodologies for radioiodination of proteins and peptides are described. The labeling systems are easy to assemble, capable of radioiodinating any protein or, with slight modifications, also peptide (molecular mass 1000-300,000) from kBq to GBq levels of activity for use in diagnosis and/or therapy. Furthermore, the procedures are feasible in any nuclear medicine department. Gigabecquerel amounts of activity can be handled safely. The most favored iodination methodology relies on the lodogen system, a mild oxidating agent without reducing agents. Thus, protein degradation is minimized. Labeling yields are between 60 and 90%, and immunoreactivities remain {>=}85%. Other radioiodination methods (chloramine-T, Bolton-Hunter) are described and briefly discussed. (orig.)

  8. Radioiodination of monoclonal antibodies, proteins and peptides for diagnosis and therapy. A review of standardized, reliable and safe procedures for clinical grade levels kBq to GBq in the Goettingen/Marburg experience

    International Nuclear Information System (INIS)

    Simple and reliable methodologies for radioiodination of proteins and peptides are described. The labeling systems are easy to assemble, capable of radioiodinating any protein or, with slight modifications, also peptide (molecular mass 1000-300,000) from kBq to GBq levels of activity for use in diagnosis and/or therapy. Furthermore, the procedures are feasible in any nuclear medicine department. Gigabecquerel amounts of activity can be handled safely. The most favored iodination methodology relies on the lodogen system, a mild oxidating agent without reducing agents. Thus, protein degradation is minimized. Labeling yields are between 60 and 90%, and immunoreactivities remain ≥85%. Other radioiodination methods (chloramine-T, Bolton-Hunter) are described and briefly discussed. (orig.)

  9. Fetal antigen 2: an amniotic protein identified as the aminopropeptide of the alpha 1 chain of human procollagen type I

    DEFF Research Database (Denmark)

    Teisner, B; Rasmussen, H B; Højrup, P;

    1992-01-01

    Fetal antigen (FA2) was purified from second trimester human amniotic fluid by immunospecific chromatography, gel filtration and reversed-phase chromatography. Gel filtration revealed two molecular forms of FA2 eluting at volumes corresponding to an M(r) of approximately 100 kDa and 30 kDa. SDS...... aminopropeptide of the alpha 1 chain of human procollagen type I as determined by nucleotide sequences. After oxidative procedures normally employed for radio-iodination (iodogen and chloramine-T), FA2 lost its immunoreactivity. An antigen which cross-reacted with polyclonal rabbit anti-human FA2 was demonstrated...... in fetal calf serum. Gel filtration with analysis of fractions by inhibition ELISA showed that the bovine homologue was present in the same molecular forms as those in human amniotic fluid, and immunohistochemical analysis with anti-human FA2 showed that its distribution in bovine skin was identical...

  10. Receptor-purified, Bolton-Hunter radioiodinated, recombinant, human epidermal growth factor: An improved radioligand for receptor studies

    International Nuclear Information System (INIS)

    We report an assessment of the applicability of the Bolton-Hunter method to the radioiodination of epidermal growth factor (EGF). Recombinant human EGF (hEGF) could be radioiodinated successfully by this method, whereas murine EGF could not. Bolton-Hunter 125I-labeled hEGF was compared with commercial 125I-labeled hEGF prepared by the chloramine-T radioiodination method. Neither radioligand was sufficiently pure for a detailed characterization of the purportedly heterogeneous pattern of binding of EGF to its receptors. A procedure based on receptor adsorption was thus developed for repurification of the Bolton-Hunter 125I-labeled hEGF. This provided a much purer radioligand suitable for detailed studies of receptor-binding heterogeneity

  11. Evaluation of the efficacy and influence of the decontamination and sterilization of FBGs exposed to S. aureus and E. coli

    Science.gov (United States)

    Karam, Leandro Z.; Franco, Ana Paula G. O.; Tomazinho, Paulo; Signorini, Luciana; Carvalho, Lídia; Fernandes, Maria H.; Hecke, Mildred B.; Kalinowski, Hypolito J.

    2011-05-01

    The FBGs (Fibre Bragg Grating) are adequate sensors for measuring strain in biomedical applications. This work evaluates the efficacy of some products and processes, which are used for the decontamination and sterilization of these sensors. Fibre optic samples, partially stripped of the primary coating, were contaminated by E. coli and S. aureus and suffered decontamination processes by autoclave heating, immersion in ethylene oxide, sodium hypochlorite, chloramine T or peracetic acid and illumination ultra-violet radiation. After each process fibre samples were removed, washed in sterile saline and placed individually in BHI broth tubes. Tubes that showed turbidity of the BHI broth were considered positive. The sterilization practices by heating and immersionand avoided the formation of bacteria colonies, whereas illumination processes were not effective to avoid the bacteria colony growth.

  12. Preparation of 125I-protein A usable for up to 10 months in immunoassays

    International Nuclear Information System (INIS)

    Chloramine-T iodination of protein A from Staphylococcus aureus and gel electrophoretic purification of the iodination mixture results in a stable tracer of high specific and functional activity. Following repeated gel electrophoresis of the tracer only a single component was observed. The specific activity of the 125I-protein A was between 30 and 55 μCi/μg. The binding of 125I-protein A to rabbit immunoglobulin exceeded 90% and the tracer competed effectively with unlabelled protein A in binding to cells incubated with sera containing surface antibodies. Storage of the tracer for up to 46 weeks resulted in a moderate decrease in maximal binding to immunoglobulin (from 91% to 64%), in TCA precipitable radioactivity (from 97% to 80%) and an approx. 30% decrease in the ability to detect cell bound immunoglobulin. It is concluded that gel electrophoretic purification of 125I-protein A produces a tracer with a very long shelf life. (Auth.)

  13. Spectrophotometric determination of azathioprine in pharmaceutical formulations.

    Science.gov (United States)

    Lakshmi, C S; Reddy, M N

    1998-12-01

    Four simple and sensitive visible spectrophotometric methods (A-D) have been described for the assay of azathioprine (ATP) either in pure form or in pharmaceutical formulations. Methods A and B are based on the oxidation of ATP with excess N-bromosuccinimide (NBS) or chloramine-T (CAT) and determining the consumed NBS or CAT with a decrease in colour intensity of celestine blue (CB) (method A) or gallocyanine (GC) (method B), respectively. Methods C and D are based on the diazotisation of reduced azathioprine (RATP) with excess nitrous acid and estimating either the consumed nitrous acid (HNO(2)) with cresyl fast violet acetate (CFVA) (method C) or by coupling reaction of the diazonium salt formed with N-1-naphthyl ethylene diamine dihydrochloride (NED) (method D). All of the variables have been optimized and the reactions presented. The concentration measurements are reproducible within a relative standard deviation of 1.0%. Recoveries are 99.2-100.3%. PMID:18967434

  14. Pharmacodynamics of benziadarone labelled with 131-I

    International Nuclear Information System (INIS)

    Regarding the importance of benziodarone (Retrangor) - 2-ethyl-3-(3',5'-diiodo-4'-hidrovibenzoyl)benzofuran - in medical practice in respect of its vasodilator and uricosuric action, a working plan was developed intending to study the biological distribution of the drug rats Wistar and, using the plasmatic curve, to find out the existence of other compartments besides the intravascular one. With these data, the rhythms of benziodarone exchange were established, simulating its distribution in the organism. It was possible to develop this working project because the benziodarone structure could be labelled with iodine-131, using an isotopic exchange reaction, having chloramine T as an oxidant agent. The labelled compound was employed as radioactive tracer, and its specific activities varied from 18 uCi/mg to 20 uCi/mg

  15. In vitro evaluation of the disinfection efficacy on Eimeria tenella unsporulated oocysts isolated from broilers.

    Science.gov (United States)

    Guimarães, José S; Bogado, Alexey L Gomel; da Cunha, Thiago Cezar B; Garcia, João Luis

    2007-01-01

    The objective of this study was to evaluate in vitro the action of eight chemical principles by disinfection efficacy (DE) of Eimeria tenella oocysts. Disinfection efficacy was evaluated by either destruction or sporulation inhibition of the oocysts. Eight treatments were performed: T1 (Glutaraldehyde 42.5 g + Benzalkonium Chloride 7.5 g); T2 (Benzalkonium chloride + quaternary ammonium salt); T3 (formol 37% + Sodium Dodecylbenzene Sulfonate 12%); T4 (sodium hypochlorite 2%); T5 (Orthodichlorobenzene 60% + Xylene 30%); T6 (Polyoctyl polyamino ethyl glycine + Polyoxyethylene alkylphenol ether + Sodium Chloride); T7 (Chloramine T) and finally T8 (free iodine 2.25% + Phosphoric acid 15 g). The control test was carried out with distilled water (T9). The best DE were observed, respectively, in T3 (79.49%), T5 (75.60%) and T4 (65.56%) treatments. PMID:17706006

  16. Study and development of a radioimmunoassay of antidiuretic hormone sensitive at 10/sup -12/M

    Energy Technology Data Exchange (ETDEWEB)

    Caillens, H.; Rousselet, F. (Faculte des Sciences Pharmaceutiques, (France)); Paillard, F. (Hopital Tenon, Paris (France))

    1982-07-01

    A radioimmunoassay of antidiuretic hormone is described. The antiserum was obtained by immunization of rabbits with lysine vasopressin conjugated to hemocyanine. The specificity of the antibody was selective and directed against the pentapeptide ring of the vasopressin molecule: oxytocin showed no cross-reactivity at 10/sup -9/M. The labelled hormone (/sup 125/I-AVP) prepared using the chloramine-T method had a high specific activity (1860 Ci/mmol). Incubation was performed in an equilibrium system. Comparative studies of different separation methods of bounds and free /sup 125/I-AVP showed that the sensitivity and the precision of the standard curve were better using charcoal dextran. The limit of detection of the assay was 1,6 pg per ml.

  17. Invertase immobilization by adsorption on polymer microspheres studied by radioiodination technique

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, Alvaro A.A. de [Universidade Federal de Itajuba, MG (Brazil). Inst. de Ciencias Exatas. Dept. de Fisica e Quimica]. E-mail: alencar@unifei.edu.br; Pontin, Luiz F. [Universidade Federal de Itajuba, MG (Brazil). Inst. de Ciencias Exatas. Dept. de Matematica e Computacao]. E-mail: pontin@unifei.edu.br; Higa, Olga Z.; Ribela, Maria Tereza C.P. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Lab. de Biologia Molecular]. E-mail: ozahiga@ipen.br; Tomotani, Ester J.; Vitolo, Michele [Sao Paulo Univ., SP (Brazil). Faculdade de Ciencias Farmaceuticas. Dept. de Tecnologia Bioquimico-Farmaceutica]. E-mail: michenzi@usp.br

    2005-07-01

    In this paper, we report the study of the diffusion behavior of invertase onto polystyrene-divinylbenzene (PS-DVB) microspheres. To detect the surface concentration of protein adsorbed on the microspheres, the chloramine-T method was used to label invertase and has been applied to the study of protein sorption properties on the microspheres. The sorption isotherms and the diffusion coefficient (D{sub f}) were computed from experimental results and the concentration of bound invertase was determined in terms of the Fick's law. The Hill equation was applied to the data and the binding capacity of the microspheres were estimated. The results of adsorption show that the radiolabelling invertase method are efficacious at the protein surface concentration detection and can be used to investigate the enzyme immobilization by sorption properties of polymer microspheres. (author)

  18. Preparation of a 125I labelled [1,3H]imidazole: 2-n-butyl-4(5)-125I-iodo-5(4)-hydroxymethylene imidazole

    International Nuclear Information System (INIS)

    A method for the introduction of 125I in a substituted imidazole has been devised. 2-n-Butyl-4(5)-hydroxymethylene imidazole undergoes rapid and selective electrophilic substitution on the ring when treated with a halogenating agent such as, i.a., N-chlorosuccinimide. This reaction has been adapted to the preparation of 2-n-butyl-4(5)-125I-iodo-5(4)-hydroxymethylene imidazole by treatment of 2-n-butyl-4(5)-hydroxymethylene imidazole by chloramine-T in the presence of sodium iodide. The radiolabelled product purified and isolated by HPLC is obtained at a high specific activity (2200Ci/mmol) with good chemical and radiochemical yields (∼70%). (author)

  19. A radioimmunoassay for chicken avidin

    International Nuclear Information System (INIS)

    A double-antibody solid-phase radioimmunoassay for chicken avidin is reported. Avidin was labelled with 125I by the chloramine-T method. The bound and free avidin were separated with a second antibody bound to a solid matrix. In the logit-log scale the standard curve was linear from 1-2 to 100-200ng of avidin/ml. Cross-reaction of ovalbumin was less than 0.015%. Saturation of biotin-binding sites of avidin with an excess of biotin decreased radioimmunoassay values by about 15%. Recovery studies indicated that avidin can be assayed from all chicken tissues studied with radioimmunoassay, whereas the [14C]biotin/bentonite method gave poor recoveries for avidin in the liver and kidney. Radioimmunoassay and the [14C]biotin/bentonite method gave similar concentrations for oviduct avidin. (author)

  20. Clinical scale preparation and evaluation of 131I-Rituximab for Non-Hodgkin's lymphoma

    International Nuclear Information System (INIS)

    Radioimmunotherapy (RIT) with anti CD20 MoAb conjugated to a β- emitting radioisotope like 131I or 90Y has the added advantage of delivering radiation not only to tumor cells that bind the antibody but also due to a crossfire effect, to neighboring tumor cells inaccessible to the antibody. In order to make available an indigenous radioimmunotherapeutic agent for Non Hodgkin's Lymphoma (NHL), radioiodinated Rituximab has been prepared and evaluated at a clinical scale. Radioiodination of Rituximab was performed by the conventional Chloramine T method using 7.4 GBq Na131I in a lead shielded plant. Six batches of radioiodination were prepared and characterized by electrophoresis and HPLC to evaluate the reproducibility of the product. The product remained stable retaining the radiochemical purity > 95% upto 5 days after radioiodination. In vitro cell binding studies and biodistribution studies in normal Swiss mice have indicated the potential of this molecule as a radioimmunotherapeutic agent for NHL. (orig.)

  1. Kinetic model for predicting the concentrations of active halogen species in chlorinated saline cooling waters

    Energy Technology Data Exchange (ETDEWEB)

    Lietzke, M. H.; Haag, W. R.

    1979-01-01

    A kinetic model for predicting the composition of chlorinated water discharged from power plants using fresh water for cooling was previously reported. The model has now been extended to be applicable to power plants located on estuaries or on the seacoast where saline water is used for cooling purposes. When chloride is added to seawater to prevent biofouling in cooling systems, bromine is liberated. Since this reaction proceeds at a finite rate there is a competition between the bromine (i.e., hypobromous acid) and the added chlorine (i.e., hypochlorous acid) for halogenation of any amine species present in the water. Hence not only chloramines but also bromamines and bromochloramines will be formed, with the relative concentrations a function of the pH, temperature, and salinity of the water. The kinetic model takes into account the chemical reactions leading to the formation and disappearance of the more important halamines and hypohalous acids likely to be encountered in chlorinated saline water.

  2. Strategies for chemically healthy public swimming pools

    DEFF Research Database (Denmark)

    Hansen, Kamilla Marie Speht

    overview of the strategies which can be used to achieve microbiological safe water with low levels of DBPs to ensure healthy environment for bathers. There are different approaches to achieve healthy environment in public swimming pools which in this thesis are divided into three strategies: alternatives...... to chlorination, removal of precursors and DBPs, and inhibition of the DBP formation. None of the alternative disinfection agents which are used for private swimming pools are applicable for public swimming pools. Thus chlorine is the most likely future disinfectant in public swimming pools. The...... compound which is less reactive towards chlorine. Ozone is also able to remove combined chlorine and other DBPs but the reaction is slow. Activated carbon is able to adsorb precursors and DBPs except chloramines which are removed by catalytic reaction. Formation of DBPs is unavoidable. However, the...

  3. Labelling of some amino acids with radioiodine

    International Nuclear Information System (INIS)

    Some radioiodine labelled compounds which have application in nuclear medicine have been prepared. Two common techniques were employed. A comparative study on the radioiodination of the amino acids, L - tyrosine, L - a - methyl tyrosine and L-tyrosine methyl ester has been carried out by the electrophilic radioiodination technique. The blood flow reagent, antipyrine, also has been prepared by this technique using chloramine - T, iodogen and H2 O2 as oxidizing agents to generate electrophilic iodine. Radio chromatograms revealed side product impurities at long reaction times and high oxidizing agent concentrations. Comparison between the different oxidizing agents was done. Optimization of the radioiodination conditions, such as Ph of the medium, reaction time, oxidizing agent and substrate concentrations and carrier KI concentration was performed resulting in high radiochemical yields of 97% L - 3 -(131) iodotyrosine, 95% L -3-(131) iodo-a-methyl tyrosine, 88% L-3-(131) iodotyrosine methyl ester and 96% 4-(131) iodoantipyrine within short reaction times at room temperature when chloramine - T was used as oxidizing agent. Purification by high pressure liquid chromatography resulted in high radiochemically pure products suitable for medical application. Radioiodinated 3- iodotyrosine and 4- iodophenyl alanine have been prepared by the isotopic exchange technique using cuprous chloride as catalyst for the exchange reaction. The effect of solvents and the different parameters affecting the labelling yield were investigated to optimize the conditions for labelling of these compounds. Kinetic study indicated a second order reaction with an activation energy of 9.6 and 12.20 Kcal/mole for 3- iodotyrosine and 4-iodophenyl alanine respectively. Reducing agents were added to the Cu CI catalyzed reactions to improve the yield and decrease side products formation. Applying the results obtained to the radioiodination of the phenyl fatty acid 15(p-iodophenyl) pentadecanoic acid

  4. Exercise but not mannitol provocation increases urinary Clara cell protein (CC16) in elite swimmers.

    Science.gov (United States)

    Romberg, Kerstin; Bjermer, Leif; Tufvesson, Ellen

    2011-01-01

    Elite swimmers have an increased risk of developing asthma, and exposure to chloramine is believed to be an important trigger factor. The aim of the present study was to explore pathophysiological mechanisms behind induced bronchoconstriction in swimmers exposed to chloramine, before and after swim exercise provocation as well as mannitol provocation. Urinary Clara cell protein (CC16) was used as a possible marker for epithelial stress. 101 elite aspiring swim athletes were investigated and urinary samples were collected before and 1 h after completed exercise and mannitol challenge. CC16, 11β-prostaglandin (PG)F(2α) and leukotriene E(4) (LTE(4)) were measured. Urinary levels of CC16 were clearly increased after exercise challenge, while no reaction was seen after mannitol challenge. Similar to CC16, the level of 11β-PGF(2α) was increased after exercise challenge, but not after mannitol challenge, while LTE(4) was reduced after exercise. There was no significant difference in urinary response between those with a negative compared to positive challenge, but a tendency of increased baseline levels of 11β-PGF(2α) and LTE(4) in individuals with a positive mannitol challenge. The uniform increase of CC16 after swim exercise indicates that CC16 is of importance in epithelial stress, and may as such be an important pathogenic factor behind asthma development in swimmers. The changes seen in urinary levels of 11β-PGF(2α) and LTE(4) indicate a pathophysiological role in both mannitol and exercise challenge. PMID:20696561

  5. Chloramphenicol Biosynthesis: The Structure of CmlS, a Flavin-Dependent Halogenase Shwing a Covalent Flavin-Aspartate Bond

    International Nuclear Information System (INIS)

    Chloramphenicol is a halogenated natural product bearing an unusual dichloroacetyl moiety that is critical for its antibiotic activity. The operon for chloramphenicol biosynthesis in Streptomyces venezuelae encodes the chloramphenicol halogenase CmlS, which belongs to the large and diverse family of flavin-dependent halogenases (FDH's). CmlS was previously shown to be essential for the formation of the dichloroacetyl group. Here we report the X-ray crystal structure of CmlS determined at 2.2 (angstrom) resolution, revealing a flavin monooxygenase domain shared by all FDHs, but also a unique 'winged-helix' C-terminal domain that creates a T-shaped tunnel leading to the halogenation active site. Intriguingly, the C-terminal tail of this domain blocks access to the halogenation active site, suggesting a structurally dynamic role during catalysis. The halogenation active site is notably nonpolar and shares nearly identical residues with Chondromyces crocatus tyrosyl halogenase (CndH), including the conserved Lys (K71) that forms the reactive chloramine intermediate. The exception is Y350, which could be used to stabilize enolate formation during substrate halogenation. The strictly conserved residue E44, located near the isoalloxazine ring of the bound flavin adenine dinucleotide (FAD) cofactor, is optimally positioned to function as a remote general acid, through a water-mediated proton relay, which could accelerate the reaction of the chloramine intermediate during substrate halogenation, or the oxidation of chloride by the FAD(C4α)-OOH intermediate. Strikingly, the 8α carbon of the FAD cofactor is observed to be covalently attached to D277 of CmlS, a residue that is highly conserved in the FDH family. In addition to representing a new type of flavin modification, this has intriguing implications for the mechanism of FDHs. Based on the crystal structure and in analogy to known halogenases, we propose a reaction mechanism for CmlS.

  6. NEW ANALYTICAL METHODS AND THEIR VALIDATION FOR THE ESTIMATION OF METOPROLOL SUCCINATE IN BULK AND MARKETED FORMULATION

    Directory of Open Access Journals (Sweden)

    Viral Bechara

    2015-02-01

    Full Text Available Metoprolol succinate is cardiovascular agent. Mainly used for the treatment of hypertension, heart failure, and cardiovascular diseases. Purpose: Analytical methods are required to characterize drug substances and drug products composition during all phases of pharmaceutical development. Development of methods to achieve the final goal of ensuring the quality of drug substances and drug products must be implemented in conjunction with an understanding of the chemical behavior and physicochemical properties of the drug substance. This determination requires highly sophisticated instruments and methods like HPLC, HPTLC and Spectrophotometer. Hence there was a need for the development of newer, simple, sensitive, rapid, accurate and reproducible analytical methods for the routine estimation of metoprolol succinate in bulk and pharmaceutical dosage form. Methods: The present work describes two new spectrophotometric methods for the determination of metoprolol succinate in bulk and marketed formulations. Method A is based on oxidation reaction. Metoprolol succinate in presence of acidic medium reacts with excess amount of chloramine-T and remaining chloramine-T react with malachite green to produce orange colour chromogen which showed λmax at 516 nm. In Method B, the drug was diazotised with sodium nitrite in presence of hydrochloric acid and then it was coupled with β-naphthol in alkaline medium. Which produce red colour chromogen which showed λmax at 688 nm. Results: The linearity was found in concentration range of 5-30μg/ml for both method A and method B. The correlation coefficient was found to be 0.9983 and 0.9993 for method A and method B respectively. The methods were validated as per ICH guidelines. The LOD and LOQ for estimation of Metoprolol succinate were found as 0.0773, 0.2343 for method A and 0.0667, 0.2021 for method B respectively. Conclusion: Proposed methods were successfully applied for the quantitative estimation of

  7. Labeling of the Recombinant Streptokinase Using Iodine-131 as a New Thrombolytic Agent

    International Nuclear Information System (INIS)

    Stroke and acute myocardial infarction is a disease with the highest mortality in the world. WHO has estimated in 2008, 30% of deaths from heart disease and more than 80% of this cases have been occurred in developing countries. Streptokinase (SK) as an effective thrombolytic agent has been used as a drug of choice for about forty years ago. SK is plasminogen (PG) activator that converts plasminogen to active protease, called plasmin (PN) which degrades fibrin to soluble products. Recombinant streptokinase (SKA) from genetic engineering has been developed at School of Pharmacy ITB to reduce or eliminate immunogenicity of SK. However, scientific disclosures relating to dynamic and its kinetic studies in the body have still to be proven. One method that can explain this phenomenon is the pharmacological studies using radionuclide labeled compounds. Radioiodine labeled compound is used extensively and most suitable for biological studies. This paper describes the preparation of 131I-SKA and its characterization. The labeling conditions of SKA, such as chloramine-T as an oxidizing agent, amount of SKA, incubation time, and size of resin to purify the labeling yield have been observed. The result showed that the optimum condition of labeling (35.11%) was obtained using 10 µg of chloramine-T and 60 seconds of incubation time. The highest radiochemical purity (97.46 ± 1.14%) has also been obtained by passing through the resin chromatography column using 100 mg Dowex 1x8, size 50-100 mesh. The characterization of 131I-SKA with SDS PAGE method and autoradiography showed the similar performance with unlabeled-SKA (author)

  8. Removal of cyclops in pre-oxidizing cooperation water treatment process

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Zooplankton cyclops propagates profusely in waterbody, cannot be effectively inactivated by conventional disinfection process, and becomes a troublesome drinking water treatment problem. In this work, the qualitative and quantitative experimental studies were carried out on inactivation of zooplankton cyclops using oxidants, such as chlorine (Cl2), chlorine dioxide (ClO2), ozone (O3), hydrogen peroxide (H2O2), ozone/hydrogen peroxide (O3/H2O2), chloramines (Cl2-NH3) and potassium permanganate (KMnO4). The influences of various factors include different oxidant dosages, organic substance contents and pH values. The results showed that currently available oxidants used all might inactivate cyclops in some extent. According to the experimental results, chlorine dioxide, ozone, ozone/hydrogen peroxide and chloramines can be selected as effective oxidants for inactivating cyclops because of their strong inactivation abilities. Then the synergic removal effects on cyclops with ozone,ozone/hydrogen peroxide pre-oxidation followed by conventional water treatment processes were investigated. The results showed that ozone and ozone/hydrogen peroxide pre-oxidation can inactivate cyclops effectively, which then can be removed thoroughly by conventional water treatment processes. Cyclops cannot appear in water after filtration with 1.65 mg/L of ozone and 6 mg/L of hydrogen peroxide, with the inactivation rate being 62% before conventional water treatment processes. Cyclops cannot appear in water after filtration with 1.8 mg/L of ozone, with the inactivation rate being 50% before conventional water treatment processes. For different oxidants, when removal rate was the best, the inactivation rate was not the same. These results may provide reference and model for actual waterworks.

  9. Radioiodination of vasoactive intestinal peptide (VIP) using different oxidative electrophilic substitution agents

    International Nuclear Information System (INIS)

    Vasoactive Intestinal Peptide (VIP) is a linear 28 residue polypeptide with a wide range of biological activities. Various tumor cells express significant amounts of VIP receptors and this became the basis for use of radiolabelled VIP for the in vivo localization of adenocarcinomas. The VIP molecule contains two tyrosine residues, in positions 10 and 22, susceptible to iodination. This work describes the influence of the oxidation agent in the radiochemical purity and in the production of different labelled forms of VIP, analysed by high performance liquid chromatography (HPLC). Three labelling procedures using oxidant agent were employed. In the first one, Iodogen was prepared in the form of pre-coated reaction vial. In the second procedure, Iodogen was introduced as a suspension and the iodination were allowed to proceed for 30 minutes at room temperature with gentle stirring. The third labelling procedure used Chloramine T as oxidant agent after a few minutes of reaction (less than 3 minutes) at room temperature and with gentle stirring, the reaction was terminated by the addition of sodium metabisulfite solution. The radiochemical purity was determined by HPLC (R P C 18, 5 μm, 4.6 x 50 mm) eluted isocratically with 73:27 % TFA (trifluoroacetic acid 0.1% aqueous solution: acetonitrile) with a flow rate of 0.5 m L/minute. Free radioiodine was also determined by horizontal zone electrophoresis. Radioiodinated VIP was obtained with high labelling yield and radiochemical purity, in a short reaction time, when using Chloramine T as oxidant agent. The proposed isocratic HPLC system allows the separation of labelled VIP of high specific activity, necessary for receptor-mediated diagnostic procedures with radiopharmaceuticals. (author)

  10. Particle size distribution and property of bacteria attached to carbon fines in drinking water treatment

    Institute of Scientific and Technical Information of China (English)

    Wang Leilei; Chen Wei; Lin Tao

    2008-01-01

    The quantitative change and size distribution of particles in the effluents from a sand filter and a granular activated carbon (GAC) filter in a drinking water treatment plant were investigated. The average total concentration of particles in the sand filter effluent during a filter cycle was 148 particles/mL, 27 of which were larger than 2 μm in size. The concentration in the GAC effluent (561 particles/mL) was significantly greater than that in the sand filter effluent. The concentration of particles larger than 2 μm in the GAC filter effluent reached 201 particles/mL, with the amount of particles with sizes between 2 μm and 15 μm increasing. The most probable number (MPN) of carbon fines reached 43 unit/L after six hours and fines between 0.45 μm and 8.0 μm accounted for more than 50%. The total concentration of outflowing bacteria in the GAC filter effluent, 350 CFU (colony-forming units) /mL, was greater than that in the sand filter effluent, 210 CFU/mL. The desorbed bacteria concentration reached an average of 310 CFU/mg fines. The disinfection efficiency of desorbed bacteria was lower than 40% with 1.5 mg/L of chlorine. The disinfection effect showed that the inactivation rate with 2.0 mg/L of chloramine (90%) was higher than that with chlorine (70%). Experimental results indicated that the high particle concentration in raw water and sedimentation effluent led to high levels of outflowing particles in the sand filter effluent. The activated carbon fines in the effluent accounted for a small proportion of the total particle amount, but the existing bacteria attached to carbon fines may influence the drinking water safety. The disinfection efficiency of desorbed bacteria was lower than that of free bacteria with chlorine, and the disinfection effect on bacteria attached to carbon fines with chloramine was better than that with only chlorine.

  11. Modification of low-density lipoprotein by different radioiodination methods

    International Nuclear Information System (INIS)

    Scintigraphic imaging of radiolabeled low-density lipoproteins (LDL) is an interesting tool for the understanding of its role in pathomechanism of atherosclerosis. Metabolism of native LDL shows quite different pattern and kinetics as compared to that of modified LDL which is not mediated by classical LDL-receptor and accumulates in atherosclerotic lesions to form lipid-laden foam cells. Therefore we were interested whether radiolabelling of LDL induces structural modifications. We performed the iodine labeling of LDL for scintigraphic imaging of atherosclerosis by three different methods: chloramine-T (A), iodine monochloride (B) and iodogen (C). The highest radiolabelling yield of 125I was obtained by the iodogen method (75.44±13.52%) and the lowest (49.01±12.74%) by iodine monochloride. Chloramine T showed a labeling yield of 62.82±6.17%. The stability of the tracer was very high with all the methods, persisting up to 6 h (98.83±1.2% - 91.38±4.7%, 15 min vs 6 h after labeling). For the first time we not only investigated the influence of radiolabelling on relative electrophoretic mobility (REM), but also various oxidation parameters such as baseline dienes (BD), thiobarbituric acid reactive substances (TBARS), endogenous peroxides (POX) and oxidation resistance in the copper-mediated oxidation system (expressed as lag-time) were measured. Furthermore, oxidation- derived fragmentation of the lipoproteins was examined with SDS-PAGE electrophoresis. Data are expressed as % change compared to native LDL before radiolabeling. BD were reduced by 32% using the method (A), but increased by 33% and 47% with the monochloride (B) and iodogen method (C), respectively. The effect on lag-time was comparable for all the three methods, ranging from 25 to 36% reduction in lag-time. TBARS were strongly increased 5-7 fold by all the methods. REM was changed by all three methods. While by methods A and C we have found a moderate increase in REM by 1.75 and 2.0 fold

  12. Modification of low-density lipoprotein by different radioiodination methods

    Energy Technology Data Exchange (ETDEWEB)

    Sobal, G. E-mail: grazyna.sobal@akh-wien.ac.at; Resch, U.; Sinzinger, H

    2004-04-01

    Scintigraphic imaging of radiolabeled low-density lipoproteins (LDL) is an interesting tool for the understanding of its role in pathomechanism of atherosclerosis. Metabolism of native LDL shows quite different pattern and kinetics as compared to that of modified LDL which is not mediated by classical LDL-receptor and accumulates in atherosclerotic lesions to form lipid-laden foam cells. Therefore we were interested whether radiolabelling of LDL induces structural modifications. We performed the iodine labeling of LDL for scintigraphic imaging of atherosclerosis by three different methods: chloramine-T (A), iodine monochloride (B) and iodogen (C). The highest radiolabelling yield of {sup 125}I was obtained by the iodogen method (75.44{+-}13.52%) and the lowest (49.01{+-}12.74%) by iodine monochloride. Chloramine T showed a labeling yield of 62.82{+-}6.17%. The stability of the tracer was very high with all the methods, persisting up to 6 h (98.83{+-}1.2% - 91.38{+-}4.7%, 15 min vs 6 h after labeling). For the first time we not only investigated the influence of radiolabelling on relative electrophoretic mobility (REM), but also various oxidation parameters such as baseline dienes (BD), thiobarbituric acid reactive substances (TBARS), endogenous peroxides (POX) and oxidation resistance in the copper-mediated oxidation system (expressed as lag-time) were measured. Furthermore, oxidation- derived fragmentation of the lipoproteins was examined with SDS-PAGE electrophoresis. Data are expressed as % change compared to native LDL before radiolabeling. BD were reduced by 32% using the method (A), but increased by 33% and 47% with the monochloride (B) and iodogen method (C), respectively. The effect on lag-time was comparable for all the three methods, ranging from 25 to 36% reduction in lag-time. TBARS were strongly increased 5-7 fold by all the methods. REM was changed by all three methods. While by methods A and C we have found a moderate increase in REM by 1.75 and 2

  13. Labeling Lanreotide with 125I and 188Re. China

    International Nuclear Information System (INIS)

    Lanreotide (D-β-Nal-Cys-Try-D-Trp-Lys-Val-Cys-Thr-NH2) is a new somatostatin analogue. It can bind to human somatostatin receptor (hSSTR) subtype 2 through 5 with high affinity and to hSSTR subtype 1 with low affinity. We investigate labeling condition, quality control and stability in vitro of 125I-Lanreotide and 188Re-lanreotide respectively. (A) Lanreotide is labeled with 125I using Chloramine T. The effect of reaction condition (such as reaction time, pH value, Lanreotide amount, quantity of Chloramine T and reaction volume) on labeling yield is investigated in detail. (B) The labeling yield and radiochemical purity (RP) is measured with paper chromatography (PC) and Sep-Pak C18 Cartridge. For PC method, 125I-Lanreotide is spotted on the Whatman No.1 paper and developed in the mixture of CH3CH2CH2CH2OH and CH3CH2OH and NH4OH (v/v/v=5:2:1), the Rf value of every component in the mobile phase is given in table 1. For Sep-Pak C18 Cartridge methods each cartridge is washed with 10 ml of ethanol followed by 10 ml of iso-CH3CH2CH2OH solution. Aliquots of 0.1 mI sample is loaded onto the cartridge, unbound peptide (sodium iodine-125) is eluted with 5 ml of 0.5mol/L sodium acetate solution, 125I-Lanreotide is eluted with 5 mI of 95% aqueous ethanol solution. (C) The stability of 125I-Lanreotide in vitro is investigated by labeling compound incubating for 48 hours at 37 deg. C in the 0.9% sodium chloride solution and RP is tested by PC at specific time intervals. (D) Lanreotide is labeled directly with 188Re via the mixture of citrate and tartate using stannous chloride as reduced agent. The influence of reaction conditions such as pH, temperature, amount of stannous chloride, amount of Lanreotide and reaction time on labeling yield is investigated in detail. At the time, the stability in vitro quality control and animal test are evaluated

  14. Synthesis and radioimmunological characterization of testosterone-3-carboxymethyloxime-tyramine-125 I (T-3-Cmo-Ty-125 I)

    International Nuclear Information System (INIS)

    The paper presents the synthesis and radioimmunological characterization of testosterone-3-carboxymethyloxime-tyramine-15 I (T-3-CMO-Ty-125 I), a reagent used as marker in radioimmunoassay (RIA) of steroid hormones. Some of the most adequate techniques of analyzing the steroid hormones are RIA and ELISA (enzyme linked immunosorbent assay) due to their sensitivity and specificity. These techniques do not require advanced purification of the sample. In the view of developing a sensitive RIA technique for assaying the testosterone-3-carboxymethyloxime-tyramine-125 I it is necessary to obtain the reagents as anti-testosterone antibody and radioactive labeled testosterone. The carboxy derivative of the steroid hormone was activated with ethylchloroformiate and tributylamine in dioxan and coupled with tyramine-125 I. Tyramine was labelled by chloramine method. The marker was purified by thin layer chromatography and extracted in methylic alcohol. Radioimmunological characterization of the marker was carried out with the help of the anti testosterone antibody obtained in our laboratory. (authors)

  15. Sample Enrichment for Bioanalytical Assessment of Disinfected Drinking Water: Concentrating the Polar, the Volatiles, and the Unknowns.

    Science.gov (United States)

    Stalter, Daniel; Peters, Leon I; O'Malley, Elissa; Tang, Janet Yat-Man; Revalor, Marion; Farré, Maria José; Watson, Kalinda; von Gunten, Urs; Escher, Beate I

    2016-06-21

    Enrichment methods used in sample preparation for the bioanalytical assessment of disinfected drinking water result in the loss of volatile and hydrophilic disinfection byproducts (DBPs) and hence likely tend to underestimate biological effects. We developed and evaluated methods that are compatible with bioassays, for extracting nonvolatile and volatile DBPs from chlorinated and chloraminated drinking water to minimize the loss of analytes. For nonvolatile DBPs, solid-phase extraction (SPE) with TELOS ENV as solid phase performed superior compared to ten other sorbents. SPE yielded >70% recovery of nonpurgeable adsorbable organic halogens (AOX). For volatile DBPs, cryogenic vacuum distillation performed unsatisfactorily. Purge and cold-trap with crushed ice serving as condensation nuclei achieved recoveries of 50-100% for trihalomethanes and haloacetonitriles and approximately 60-90% for purged AOX from tap water. We compared the purgeable versus the nonpurgeable fraction by combining purge-and-trap extraction with SPE. The purgeable DBP fraction enriched with the purge-and-trap method exerted a lower oxidative stress response in mammalian cells than the nonpurgeable DBPs enriched with SPE after purging, while contributions of both fractions to bacterial cytotoxicity was more variable. 37 quantified DBPs explained almost the entire AOX in the purge-and-trap extracts, but <16% in the SPE extracts demonstrating that the nonpurgeable fraction is dominated by unknown DBPs. PMID:27153244

  16. Radioimmunoassay of triiodothyronine in urine

    International Nuclear Information System (INIS)

    In 21 cases of hypothyroidism, in 39 cases of hyperthyroidism, in 54 healthy subjects, in 23 pregnant women, and in certain internal diseases determinations of triiodothyronine were carried out in urine by radioimmunoassay. Anti-T3 antibodies were obtained in rabbits and sheep immunized with a complex of bovine albumin with triiodothyronine ester. Labelled triiodothyronine of high specific activity was obtained by iodinating triodothyronine by the chloramine method. Determinations of triiodothyronine were performed in morning urine and the obtained values were calculated for one-hour excretion. In healthy subjects the excretion of T3 was from 20 to 95 ng/hour, in hyperthyroidism it was significantly raised to from 120 to over 600 ng/hour, while in most cases of hypothyroidism it was decreased. In pregnancy the urinary excretion of T3 was normal amounting to from 34 to 87 ng/hour, although in most cases the serum T3 concentration was raised. In cases of anorexia nervosa and in obese starving subjects the excretion of T3 fell significantly, and similarly low excretion was found in some cases of debilitating diseases and myocardial infarction. (author)

  17. Selective mono-radioiodination and characterization of a cell-penetrating peptide. L-Tyr-maurocalcine

    International Nuclear Information System (INIS)

    Mono-and poly-iodinated peptides form frequently during radioiodination procedures. However, the formation of a single species in its mono-iodinated form is essential for quantitative studies such as determination of tissue concentration or image quantification. Therefore, the aim of the present study was to define the optimal experimental conditions in order to exclusively obtain the mono-iodinated form of L-maurocalcine (L-MCa). L-MCa is an animal venom toxin which was shown to act as a cell-penetrating peptide. In order to apply the current direct radioiodination technique using oxidative agents including chloramine T, Iodo-Gen registered or lactoperoxidase, an analogue of this peptide containing a tyrosine residue (Tyr-L-MCa) was synthesized and was shown to fold/oxidize properly. The enzymatic approach using lactoperoxidase/H2O2 was found to be the best method for radioiodination of Tyr-L-MCa. MALDI-TOF mass spectrometry analyses were then used for identification of the chromatographic eluting components of the reaction mixtures. We observed that the production of different radioiodinated species depended upon the reaction conditions. Our results successfully described the experimental conditions of peptide radioiodination allowing the exclusive production of the mono-iodinated form with high radiochemical purity and without the need for a purification step. Mono-radioiodination of L-Tyr-MCa will be crucial for future quantitative studies, investigating the mechanism of cell penetration and in vivo biodistribution.

  18. Preparation, purification and primary bioevaluation of radioiodinated ofloxacin. An imaging agent

    Energy Technology Data Exchange (ETDEWEB)

    Kandil, Shaban; Seddik, Usama; Hussien, Hiba; Shaltot, Mohamed [Atomic Energy Authority, Cairo (Egypt). Cyclotron Project; El-Tabl, Abdou [Monofia Univ. (Egypt). Faculty of Science

    2015-07-01

    The broad-spectrum antibiotic agents have been demonstrated as promising diagnostic tools for early detection of infectious lesions. We set out ofloxacin (Oflo), a second-generation fluoroquinolone, for the radioiodination process. In particular, this was carried out with {sup 125}I via an electrophilic substitution reaction. The radiochemical yield was influenced by different factors; drug concentration, different oxidizing agents, e.g. chloramine-T, iodogen and n-bromosuccinimide, pH of medium, reaction time, temperature and different organic media. These parameters were studied to optimize the best conditions for labeling with ofloxacin. We found that radiolabeling in ethanol medium showed a 70% radiochemical yield of {sup 125}I-ofloxacin. The radioiodination was determined by means of TLC and HPLC. The cold labeled Oflo ({sup 127}I-Oflo) was prepared and controlled by HPLC. The cold labeled Oflo was also confirmed by NMR and MS techniques. Furthermore, biodistribution studies for labeled {sup 125}I-Oflo were examined in two independent groups (3 mice in each one); control and E. Coli-injected (inflamed). The radiotracer showed a good localization in muscle of thigh for inflamed group as compared to control. In conclusion, ofloxacine might be a promising target as an anti-inflammatory imaging agent.

  19. {sup 99m}Tc-labeled chimeric anti-NCA 95 antigranulocyte monoclonal antibody for bone marrow imaging

    Energy Technology Data Exchange (ETDEWEB)

    Sarwar, M.; Higuchi, Tetsuya; Tomiyoshi, Katsumi [Gunma Univ., Maebashi (Japan). School of Medicine] [and others

    1998-09-01

    Chimeric mouse-human antigranulocyte monoclonal antibody (ch MAb) against non-specific cross-reacting antigen (NCA-95) was labeled with {sup 99m}Tc (using a direct method) and {sup 125}I (using the chloramine T method), and its binding to human granulocytes and LS-180 colorectal carcinoma cells expressing carcinoembryonic antigen on their surfaces, cross-reactive with anti-NCA-95 chimeric monoclonal antibody, increased in proportion to the number of cells added and reached more than 80% and 90%, respectively. In biodistribution studies, {sup 99m}Tc and {sup 125}I-labeled ch anti-NCA-95 MAb revealed high tumor uptake, and the tumor-to-blood ratio was 2.9 after 24 hours. The tumor-to-normal-organ ratio was also more than 3.0 in all organs except for the tumor-to-kidney ratio. Scintigrams of athymic nude mice confirmed the results of biodistribution studies that showed higher radioactivity in tumor and kidney of the mice administered with {sup 99m}Tc-labeled ch MAb. A normal volunteer injected with {sup 99m}Tc-labeled ch anti-NCA-95 antigranulocyte MAb showed clear bone marrow images, and a patient with aplastic anemia revealed irregular uptake in his lumbar spine, suggesting its utility for bone marrow scintigraphy and for the detection of hematological disorders, infections, and bone metastasis. (author)

  20. Characterization of tumour virus proteins. I. radioimmunoassay of the P27 protein of avian viruses

    International Nuclear Information System (INIS)

    The major structural protein of avian oncornaviruses, a core component of about 27000 daltons, has been measured by radioimmunoassay. The purified protein was labelled with 125Iodine by chloramine-T method. The immune serum titer was defined as the highest serum dilution able to precipitate 50% of the labelled antigon present in the system. Standard competition curve was constructed in order to determine the equivalents of protein, in a system with limiting antibody concentration. In the experimental conditions used, 0.14 ng of AMV-P27 inhibited 50% of 125I-AMV-P27 (1.0 ng) precipitation. The 125I-AMV-P27 vs anti-AMV-P27 system was used to study the competition of normal cells, purified virus suspension, productive cells and supernatant fluids. Most of the chicken ombryo fibroblast showed expression of this viral component. The phenomena of cell transformation, the increase in total protein, and the expression of P27 were studied in rapid transformation of CEF by RSV-SR sub(A)

  1. Proteins labelling with 125I and experimental determination of their specific activity

    International Nuclear Information System (INIS)

    A standardization of the labelling technique of proteins with 125I and the control of the obtained products, principally their specific activities was performed, in order to utilize them correctly in radioimmunoassays. The quantities of chloramine-T and sodium metabisulphite were lowered, with regard to the original method, to 3.6 and 9.6 μg respectively. Under these conditions, optimal yields and radioiodinated proteins with good immunological activities were obtained. It was found that the specific activity calculated, as usual, from the yield obtained by electrophoresis, is higher than the real value. For these reasons the yields and the corresponding specific activities were determined from ascending chromatographies performed with 70 per cent methanol as solvent, during two hours in darkness. The radioimmunoassay displacement curves obtained with proteins labelled which the proposed method and the specific activities of which were calculated from their radiochromatographic patterns, were reproducible and gave a percentage of bound radioiodinated protein in the absence of cold protein of 50 +- 4. (author)

  2. Free Radical Chemistry of Disinfection Byproducts. 3. Degradation Mechanisms of Chloronitromethane, Bromonitromethane and Dichloronitromethane

    International Nuclear Information System (INIS)

    Halonitromethanes (HNMs) are byproducts formed through ozonation and chlorine/ chloramine disinfection processes in drinking waters that contain dissolved organic matter and bromide ions. These species occur at low concentration, but have been determined to have high cytotoxicity and mutagenicity and therefore may represent a human health hazard. In this study, we have investigated the chemistry involved in the mineralization of HNMs to non-hazardous inorganic products through the application of advanced oxidation and reduction processes. We have combined measured absolute reaction rate constants for the reactions of chloronitromethane, bromonitromethane and dichloronitromethane with the hydroxyl radical and the hydrated electron with a kinetic computer model in an attempt to elucidate the reaction pathways of these HNMs. The results are compared to measurements of stable products resulting from steady-state 60Co y-irradiations of the same compounds. The model predicted the decomposition of the parent compounds and ingrowth of chloride and bromide ions with excellent accuracy, but the prediction of the total nitrate ion concentration was slightly in error, reflecting the complexity of nitrogen oxide species reactions in irradiated solution.

  3. Development of an 'In vitro' system for the caption essay of T3; Desarrollo de un sistema 'In vitro' para el ensayo de captacion de T3

    Energy Technology Data Exchange (ETDEWEB)

    Lavalley, C.; Ferro, G.; Zambrano, F.; Lezama, J

    1990-02-15

    Triiodothyronine uptake (T3U) is a qualitative technique for evaluation of the unsaturation capacity of thyroid binding globulin (TBG). This paper presents results related to a T3 standardized serum and the integration of T3-I-125, and adsorbent for labelled hormone. Labelled hormone were prepared by the chloramine T method and then purified by high performance liquid chromatography. The specific activity was 500 {mu} Ci/ {mu} g. Various adsorbents such as: Norit A Charcoal, calcium silicate, talc, bovine serum albumin macroaggregated (BSAM) were used in different buffers as: Tris-HCl, barbital and Michaelis. Standardized serum was prepared by mixing different euthyroid sera. Best conditions for T3U assays were achieved with 15 mg/ml. BSAM at pH 8.6 in presence of Tris-HCl buffer for hypothyroid and hyperthyroid sera, for which we obtained < 0.9 {+-} 0.04 and > 1.1 {+-} 0.05 respectively as a T3U index with a 3.0 % of coefficient variation. The reagents so prepared can be conveniently used for T3U assays. (Author)

  4. The characters of 125I-VIP binding to the receptors derived from human gastrointestinal adenocarcinoma and their adjacent tissues

    International Nuclear Information System (INIS)

    To investigate the characteristics of 125I-VIP binding to human gastrointestinal adenocarcinoma and their adjacent tissue. VIP was labelled with Na 125I using chloramine -T method, separated by Sephadex G-50 column chromatography and examined by silica 60F254 thin layer chromatography. The effects of time and temperature on the specific binding were examined, saturable binding and competitive binding between 125I-VIP and VIP receptors in membranes from gastrointestinal adenocarcinoma and their adjacent tissue were carried out. The results showed that labelling rate was 70%, the specific activity of 125I-VIP was 18TBq/mmol, the radiochemical purity was better than 98%. A single specific binding sites of high affinity were present in gastric adenocarcinoma and its adjacent tissue as well as in colon adenocarcinoma and its adjacent tissue. The Kd and Bmax values were 1.19 nmol/L and 339 fmol/mg protein, 1.26 nmol/L and 156 fmol/mg protein, 0.97 nmol/L and 304 fmol/mg protein, 1.53 nmol/L and 151 fmol/mg protein respectively. The present study demonstrated that the binding sites of VIP on human gastrointestinal adenocarcinoma were more abundant than their adjacent tissue membrane, which provide valuable experimental evidence for VIP receptor imaging

  5. Preparation of 125I-labeled human growth hormone of high quality binding properties endowed with long-term stability

    International Nuclear Information System (INIS)

    125I-labeled human growth hormone (125I-labeled.hGH) was prepared by using two variants of the chloramine T labelling procedure and purified by polyacrylamide gel electrophoresis (PAGE) of the reaction mixture. Variant A produced a tracer with high specific activity (100 +/- 10 microCi/microgram), high maximal binding capacity to antibodies (93%) and long-term stability (at least 150 days at -20/degree/C). No diiodinated tyrosil residues could be detected in this tracer. Variant B was devised to obtain higher yields of labeled hormone. The electrophoresis of the iodination mixture revealed two radioactive components with Rm values of 0.49 and 0.55 which result from the iodination of hGH variants preexisting in the starting material. Both tracers had similar specific activities (70 +/- 10 microCi/microgram), high maximal binding capacity to antibodies or receptors (80-100%, after 80 days of their obtention) and high stability (at least 100 days at -20/degree/C). It is concluded that the iododerivatives of hGH obtained by either method are adequate to perform radioimmunoassay and receptor studies and have long-term stability

  6. Iodine-125 Chitosan-Vitamin C complex. Preparation, characterization and application

    Energy Technology Data Exchange (ETDEWEB)

    Elbarbary, Ahmed M. [National Center for Radiation Research and Technology, Cairo (Egypt). Polymer Chemistry Dept.; Shafik, H.M.; Ebeid, N.H.; Ayoub, S.M. [Atomic Energy Authority, Cairo (Egypt). Hot Lab. Center; Othman, Sameh H. [Atomic Energy Authority, Cairo (Egypt). Nuclear Research Center

    2015-07-01

    In heterogeneous conditions, water soluble Chitosan-Vitamin C Complex (CSVC) is successfully synthesized via the ionic interaction between γ-degraded CS and VC. Chitosan (CS) of low molecular weight (MW) is prepared using γ-irradiation method. The coupling of CS and vitamin C (VC) is carried out by the chemical treatment of VC with the γ-degraded CS. The formation of CSVC complex instead of physical mixture is confirmed by FT-IR and UV spectrometry. Characterization by transmission electron microscope (TEM) and dynamic light scattering (DLS) shows the formation of a nanostructure in 40 nm range. The preparation of labeled CSVC was performed using chloramines-T oxidation method. The labeling feasibility of CSVC nanostructure by Iodine-125 ({sup 125}I) is investigated. The optimized conditions of labeling are thought to be 50 μg of oxidizing agent, pH 3, and one minute reaction time. The Biodistribution activity of {sup 125}I radiolabeled CSVC nanostructure ({sup 125}I-CSVC) is examined on a group of different ascites tumor bearing mice. Calculation of the biodistribution percentages shows that the tumor, liver, and kidney are the targeting organs of {sup 125}I-CSVC nanostructure.

  7. Composition of cross-linked 125I-follitropin-receptor complexes

    International Nuclear Information System (INIS)

    Both of the alpha and beta subunits of intact human follitropin (FSH) were radioiodinated with 125I-sodium iodide and chloramine-T and could be resolved on sodium dodecyl sulfate-polyacrylamide gels. Radioiodinated FSH was affinity-cross-linked with a cleavable (nondisulfide) homobifunctional reagent to its membrane receptor on the porcine granulosa cell surface as well as to a Triton X-100-solubilized form of the receptor. Cross-linked samples revealed three additional bands of slower electrophoretic mobility, corresponding to 65, 83, and 117 kDa, in addition to the hormone bands. The hormone alpha beta dimer band corresponded to 43 kDa. Formation of the three bands requires the 125I-hormone to bind specifically to the receptor with subsequent cross-linking. Binding was prevented by an excess of the native hormone but not by other hormones. A monofunctional analog of the cross-linking reagent failed to produce the three bands. Reagent concentration-dependent cross-linking revealed that their formation was sequential; smaller complexes formed first and then larger ones. When gels of cross-linked complexes were treated to cleave covalent cross-links and then electrophoresed in a second dimension, 18-, 22-, and 34-kDa components were released, in addition to the alpha and beta subunits of the hormone

  8. Oxidative radioiodination damage to human lactoferrin

    International Nuclear Information System (INIS)

    Oxidative iodination of human lactoferrin (Lf) commonly performed by using the chloramine-T, the Iodogen or the lactoperoxidase method produces an unreliable tracer protein because of excessive and heterogeneous polymer formation. Before iodination a minor tetramer fraction may be demonstrable in iron-saturated Lf only. 125I-Lf polymers are mainly covalently linked, as suggested by the lack of substantial dissociation in SDS/polyacrylamide-gel electrophoresis. Damage to the 125I-Lf monomer may be another consequence of oxidative iodination. This is demonstrated in SDS/polyacrylamide-gel electrophoresis where 50% of the radioactivity of apparently normal monomer (Msub(r) 75000) is displaced to a lower-Msub(r) region (30000-67000) after reduction with dithiothreitol. Non-oxidative iodination by the Bolton-Hunter technique produces an antigenetically stable tracer that is not being subjected to polymerization and monomer degradation as judged by high performance gel chromatography and SDS/polyacrylamide-gel electrophoresis with and without dithiothreitol treatment. It is concluded that oxidation in itself leads to covalent non-disulphide cross-linking between human Lf molecules and, possibly, to intramolecular peptide-bond breaking becoming unmasked under reducing conditions. (author)

  9. Preparation of 5-Iodo-2'- deoxyuridine labelled with 125 I

    International Nuclear Information System (INIS)

    5-Iodo-2'-deoxyuridine (IUdR), an analogue of thymidine is taken up by the proliferating cells during DNA synthesis. When IUdR is labelled with 125 I, due to Auger electrons from 125 I, this analogue of thymidine is very effective in cell destruction when is internalized. Recently, radioiodinated (125 I and 123 I) IUdR is considered a potential therapeutic agent, for treatment of cancer.125 I-IUdR was prepared by direct radioiodination of 2'-deoxyuridine (UdR), using chloramine T method. The radioiodination reaction was studied by varying the reaction parameters such as temperature and reaction time. The yield was improved by heating the reaction mixture to 65 deg. C for 10 min. Purification of 125 I-IUdR was carried out by gel filtration over a Sephadex G 25 column using 0.05 M citrate buffer (pH = 6). The yield of the reaction as well as the radiochemical purity were determined by paper electrophoresis using Whatman chromatography paper No.1, 0.05 M phosphate buffer at 13 V/cm. The analyse time was 1 h. The yield of radioiodination reaction was ≅70% and the radiochemical purity of 125 I-IUdR prepared by this method was: 91-92%. (authors)

  10. An immunoradiometric assay (IRMA) using an iodinized monoclonal antibody in the determination of two glycoprotein hormones, thyrotropine (TSH) and human choriongonadotropine (HCG)

    International Nuclear Information System (INIS)

    An immunoradiometric assay was developed for the determination of thyrotropine that uses an iodinized monoclonal antibody and a double-antibody separation technique. A monoclonal antibody to TSH served for a tracer, which was labelled with iodine-125 using the chloramine-T method and found to be sufficiently stable. The 1st antibody was rabbit anti-TSH made into a 1:500 dilution. Anti-rabbit globulin was chosen as the 2nd antibody. The basic concept of combining a monoclonal antibody tracer and a double-antibody separation technique proved to be an unfortunate one, as far as the development of an IRMA for hCG was concerned. In the determination of TSH, the IRMA's lower limit of detection was found to be 0.3 μIU/ml. By contrast with a RIA used on a routine basis in the same laboratory, the IRMA under investigation appeared to more susceptible to fluctuations. Further tests will be needed to gain better insights into the causative factors. (orig./MG)

  11. Radioimmunoassay of Human Thyrotropin - Part 1. Plasma TSH levels in various thyroid functions

    International Nuclear Information System (INIS)

    The radioimmunoassay of human thyrotropin was performed in various thyroid states, utilizing the anti-h-T.S.H. antibody and purified human thyrotropin supplied from National Institute of Arthritis and Metabolic Diseases, Bethesda, Ma., U.S.A., and human thyrotropin standard-A obtained from National Institute for Biologic Standards, Mill Hill, London, England. 131I labelled h-TSH was prepared after the Chloramine-T method of Greenwood et al. This double antibody system had a assay sensitivity of about l. 0 μU/ml of plasma HTS-A and could detect the plasma h-TSH level in the euthyroid patients. Plasma h-TSH level of the normal 26 Korean was l.1±0. 83 μU/ml, and that of the 8 hypothyroidisms were 8.3 to 67.5 μU/ml. In hyperthyroidisms, no cases showed the plasma h-TSH levels over l. 0 μU/ ml. Between the hypothyroidism and euthyroidism, no overlap is noticed on plasma h-TSH levels. A case of transient hypothyroid state identified by determination of plasma h-TSH level is presented. These results revealed that the radioimmunoassay of h-TSH in plasma could be a sensitive method to diagnose the hypothyroidism, if not caused by a pituitary disease.

  12. Preparation of directly iodinated steroid hormones and related directly halogenated compounds

    International Nuclear Information System (INIS)

    The preparation of directly iodinated radioactive steroid hormones is described for use in radioimmunoassays or radiolocalization and treatment of human breast tumours. The radioactive iodinated steroid hormone is prepared by reacting a parent steroid hormone with an alkali metal iodide containing radioactive 123I, 125I, 130I or 131I in the presence of hydrogen peroxide or chloramine-T. The parent steroid hormones include the adrenal corticosteroids, the estrogens, the progestogens, the progestins and the diuretic and antidiuretic agents. The radioactive iodinated steroid hormone is prepared by iodinating the parent steroid hormone directly on the cyclopentanophenanthrene nucleus. The radioactive iodinated steroid hormones have the same antigenicity and receptor site specificity as the parent steroid hormone. The invention is illustrated by 1) the method of iodination of estradiol-17β, 2) results for the percentage labelling of several steroids and steroid hormones, 3) results for the radioimmunoassay of 125I-estradiol and 4) results for the binding of directly iodinated estradiol-17β in an estrogen receptor assay of human breast cancer. (U.K.)

  13. The contribution of mediated oxidation mechanisms in the electrolytic degradation of cyanuric acid using diamond anodes.

    Science.gov (United States)

    Bensalah, Nasr; Dbira, Sondos; Bedoui, Ahmed

    2016-07-01

    In this work, the contribution of mediated oxidation mechanisms in the electrolytic degradation of cyanuric acid using boron-doped diamond (BDD) anodes was investigated in different electrolytes. A complete mineralization of cyanuric acid was obtained in NaCl; however lower degrees of mineralization of 70% and 40% were obtained in Na2SO4 and NaClO4, respectively. This can be explained by the nature of the oxidants electrogenerated in each electrolyte. It is clear that the contribution of active chlorine (Cl2, HClO, ClO(-)) electrogenerated from oxidation of chlorides on BDD is much more important in the electrolytic degradation of cyanuric acid than the persulfate and hydroxyl radicals produced by electro-oxidation of sulfate and water on BDD anodes. This could be explained by the high affinity of active chlorine towards nitrogen compounds. No organic intermediates were detected during the electrolytic degradation of cyanuric acid in any the electrolytes, which can be explained by their immediate depletion by hydroxyl radicals produced on the BDD surface. Nitrates and ammonium were the final products of electrolytic degradation of cyanuric acid on BDD anodes in all electrolytes. In addition, small amounts of chloramines were formed in the chloride medium. Low current density (≤10mA/cm(2)) and neutral medium (pH in the range 6-9) should be used for high efficiency electrolytic degradation and negligible formation of hazardous chlorate and perchlorate. PMID:27372125

  14. Synthesis of 125 I - Salicyl Hydroxamic Acid for Urinary Bladder Imaging

    International Nuclear Information System (INIS)

    Salicylhydroxamic acid is a salicylate derivative. Radiolabeling of Salicyl hydroxamic acid ( SHA ) with iodine-125 may have considerable interest for imaging of urinary bladder. This study is aimed to optimize the radiolabeling yield of Salicyl hydroxamic with radio iodine (125-123) using chloramine - T (CAT) as an oxidizing agent with respect to factors that affect the reaction conditions such as SHA amount, CAT amount, reaction time and ph of the reaction mixture. In - vitro stability of the radiolabeled complex was checked and it was found to be stable for up to 24 h. 125 I-SHA was injected via intravenous administration routes into normal male Sprague – Dawley rats. Bio - distribution studies have revealed that 125I-SHA was excreted in urine with extent that it could give a clear image for urinary bladder especially if the bladder it tightly closed. The amount of 125 I - Salicyl hydroxamic excreted was increased in case of giving potassium bicarbonate to rat before injection of 125 I-SHA. The result of biodistribution study of 125 I - SHA in experimental animal suggest ed the possibility of using 123 I-SHA to image the urinary bladder

  15. Spectrophotometric Determination of Trace Cyanide in Fruit Wines by the Catalytic Reaction of Ninhydrin Following Micro-Distillation

    Directory of Open Access Journals (Sweden)

    Saksit Chanthai

    2014-03-01

    Full Text Available Trace analysis of cyanide (CN based on the absorbance of the catalytic reaction of ninhydrin (NH in the presence of CN- was developed. This reaction was investigated consisting of 0.08 M NH, 0.4 M Na2CO3, 1% (v/v Tween 20 and 2.5 M NaOH in 5-mL final volume. The absorbance of the CN-NH complex was measured against the reagent blank at 598 nm. The calibration curve was widely linear over the range of 40-160 µg/L with r2 >0.99. The method recoveries of free cyanide, bound cyanide and total cyanide for wine samples were found in the range of 76.2-89.2%, 73.2-91.2% and 76.8-94.8%, respectively, at 250 µg/L CN- spiked level. Limit of detection was 6 µg/L. The reproducibility of the proposed method was less than 4.44%. This method was then applied for local Thai fruit wines. No trace amount of cyanide was detected, as if high recovery (88.4% of the micro-distillation was guaranteed. The obtained results were in agreement with those of the chloramine-T/barbituric acid-pyridine method with no statistically significant difference at 95% confidence level.

  16. Heterotrophic bacteria in drinking water distribution system: a review.

    Science.gov (United States)

    Chowdhury, Shakhawat

    2012-10-01

    The microbiological quality of drinking water in municipal water distribution systems (WDS) depends on several factors. Free residual chlorine and/or chloramines are typically used to minimize bacterial recontamination and/or regrowth in WDS. Despite such preventive measures, regrowth of heterotrophic (HPC) and opportunistic bacteria in bulk water and biofilms has yet to be controlled completely. No approach has shown complete success in eliminating biofilms or HPC bacteria from bulk water and pipe surfaces. Biofilms can provide shelter for pathogenic bacteria and protect these bacteria from disinfectants. Some HPC bacteria may be associated with aesthetic and non-life threatening diseases. Research to date has achieved important success in understanding occurrence and regrowth of bacteria in bulk water and biofilms in WDS. To achieve comprehensive understanding and to provide efficient control against bacteria regrowth, future research on bacteria regrowth dynamics and their implications is warranted. In this study, a review was performed on the literature published in this area. The findings and limitations of these papers are summarized. Occurrences of bacteria in WDS, factors affecting bacteria regrowth in bulk water and biofilms, bacteria control strategies, sources of nutrients, human health risks from bacterial exposure, modelling of bacteria regrowth and methods of bacteria sampling and detection and quantification are investigated. Advances to date are noted, and future research needs are identified. Finally, research directions are proposed to effectively control HPC and opportunistic bacteria in bulk water and biofilms in WDS. PMID:22076103

  17. Biodistribution and radioimmunoimage of iodine-125 labeled anti-human ADAM15 polyclonal antibody in nude mice bearing human gastric carcinoma xenografts

    International Nuclear Information System (INIS)

    Objective: To investigate the biodistribution of Iodine-125 labeled anti-human ADAM15 polyclonal antibody in nude mice bearing human gastric carcinoma xenografts. Methods: The anti-human ADAM15 polyclonal antibody was labeled with I-125 using Chloramine-T method. The labeling efficiency and radiochemical purity of 125I-anti-ADAM15 antibody were measured. The SPECT planar imaging of nude mice bearing gastric carcinoma xenografts were performed at 1, 4, 8, 24, and 48 h post-injection and the biodistribution of 125I-anti-ADAM15 antibody was measured at 48 h after injection. Results: The labeling efficiency of 125I-anti-ADAM15 antibody was (75.16±9.43)% and its radiochemical purity was (99.44±0.21)% . Tumors could be cleanly visualized in SPECT planar images, and the radioactivity ratio of tumor to non-tumor tissue was 3.84±0.43 at 48 h post-injection. Conclusion: 125I-anti-ADAM15 antibody can target the gastric carcinoma in vivo, and provide good radioimmunoimages. (authors)

  18. Pilot plant studies on the treatment of El Atshan Uranium Ores, Eastern Desert, Egypt

    International Nuclear Information System (INIS)

    The present work deals with studying the different processes leading to the preparation of commercial uranium concentrate (yellow cake) from El Atshan granitic ore material (0.077%U) after acid leading of the latter, the two common extraction techniques of uranium from the obtained sulphate leach liquor; namely, anion exchange rein and solvent extraction have been studied. The studied leaching and extraction conditions-realized on the lab scale-were applied to inches pilot plant unit (capacity 150 kg ore). An average leaching leaching efficiency exceeding 88% has been achieved. Using anion exchange resin, it has been possible to prepare a uranium peroxide concentrate assaying a uranium content of about 67% U3 O8. Only trace amount of Ca, Fe, Po4, Cr and Pb have been detected. On the other hand, sodium uranate, as a uranium precipitate was prepared from the strip solution of the loaded solvent (di-2-ethyl phosphoric acid concerned with the evaluation of a new optimized technique for the principle of chloramine-T method used for insulin iodination for the modified procedure can be carried out under normal condition of room temperature, employed longer reaction times and omitted the addition of inorganic reducing salts maintaining efficient iodination and avoiding denaturation to obtain labels of exceedingly high specific activity and small quantities of insulin for in vitro usage in the investigation of human erythrocytes 125 I-inulin binding capacity in normal and in some disease status. 9 figs., 2 tabs

  19. Radioimmunoassay of chicken growth hormone using growth hormone produced by recombinant DNA technology: validation and observations of plasma hormone variations in genetically fat and lean chickens

    Energy Technology Data Exchange (ETDEWEB)

    Picaper, G.; Leclercq, B.; Saadoun, A.; Mongin, P.

    1986-01-01

    A radioimmunoassay (RIA) of chicken growth hormone (c-GH) has been developed using growth hormone produced by recombinant DNA technology. The best rabbit antiserum was used at 1/300,000 final dilution. Hormone labelling by iodine-125, achieved by chloramine T, allowed a specific activity of 3.7 MBq/..mu..g. The equilibrium curves show that optimal conditions of incubation were reached at room temperature for 24h. This RIA used a second sheep antibody which precipitated the whole c-GH bound to the first antibody in the presence of polyethylene glycol solution (6%) at room temperature for 30 min. In our conditions, sensitivity was about 30 pg of c-GH per tube. Coefficient of variation was around 10%. No cross reaction was found with avian LH and prolactin. Thyrotrophin-releasing hormone (TRH) injection to young chickens induced 20-fold higher plasma c-GH concentrations. Simultaneous injection of somatostatin and TRH slightly reduced these concentrations. Hypoglycemia induced by insulin led to a drop of the plasma c-GH concentration. Conversely, refeeding or glucose load induced slight increases of the c-GH level. Genetically fat chickens tended to exhibit higher plasma c-GH concentrations than lean chickens.

  20. Occurrence of disinfection byproducts in United States wastewater treatment plant effluents

    KAUST Repository

    Krasner, Stuart W.

    2009-11-01

    Effluents from wastewater treatment plants (WWTPs) contain disinfection byproducts (DBPs) of health concern when the water is utilized downstream as a potable water supply. The pattern of DBP formation was strongly affected by whether or not the WWTP achieved good nitrification. Chlorine addition to poorly nitrified effluents formed low levels of halogenated DBPs, except for (in some cases) dihalogenated acetic acids, but often substantial amounts of N-nitrosodimethyamine (NDMA). Chlorination of well-nitrified effluent typically resulted in substantial formation of halogenated DBPs but much less NDMA. For example, on a median basis after chlorine addition, the well-nitrified effluents had 57 μg/L of trihalomethanes [THMs] and 3 ng/L of NDMA, while the poorly nitrified effluents had 2 μg/L of THMs and 11 ng/L of NDMA. DBPs with amino acid precursors (haloacetonitriles, haloacetaldehydes) formed at substantial levels after chlorination of well-nitrified effluent. The formation of halogenated DBPs but not that of NDMA correlated with the formation of THMs in WWTP effluents disinfected with free chlorine. However, THM formation did not correlate with the formation of other DBPs in effluents disinfected with chloramines. Because of the relatively high levels of bromide in treated wastewater, bromine incorporation was observed in various classes of DBPs. © 2009 American Chemical Society.

  1. Biochemical assays with radio-iodinated substrates

    International Nuclear Information System (INIS)

    A sensitive radiochemical method for the measurement of nanogram amounts of ammonia applicable to studies of enzymatic or other processes releasing or utilizing ammonia was developed. The method is based on a modified Berthelot reaction between ammonia and an aqueous alkaline solution of phenol and sodium hypochloride to yield indophenol. The radioactive tracer used is 125I-o-iodophenol, prepared by iodination of phenol with 125I by the chloramine-T method. A chloroform/carbon tetrachloride mixture is used to extract unreacted 125I-o-iodophenol from the reaction mixture; the 125I-labelled product remains in the aqueous phase and is measured by scintillation counting. Non-protein nitrogenous substances and certain other compounds interfere with the reaction, which cannot thus be used to measure ammonia directly in biological fluids. The glass Conway microdiffusion cell may, however, be utilized to isolate small amounts of ammonia from such fluids for measurement. The fluid is placed in the centre well of the cell and cold water in the outer well. Warm saturated potassium carbonate solution is then added to the centre well to expel the ammonia gas which is absorbed by the water. Technical details of the method are given

  2. Preparation of a 125I-labelled conjugate of pteroylglutamic acid and its use in a radio ligand assay of folate in blood

    International Nuclear Information System (INIS)

    The synthesis of a 125I-labelled folate derivative is described for use in the radioassay of folate in serum and whole blood haemolysate. Pteroylglutamic acid (PGA) was conjugated with tyramine in dimethylformamide solution using a mixed anhydride procedure. The product was characterised by its ultra-violet absorption spectrum and its electrophoretic mobility. Iodination of this conjugate with 125I, using Chloramine-T as oxidant, was carried out and gave high incorporation of label. The iodinated product, which was separated from other reactants by a simple and rapid Amberlite-IRA-400 resin separation technique, bound avidly to the folate-binding protein of cow's milk, enabling dose response curves to be constructed which provided a sensitive and precise assay for folate in serum and whole blood haemolysates. Comparison of the results obtained on serum and whole blood haemolysates with an established microbiological procedure gave good agreement. The radioassay described had improved precision at low folate levels where the discriminating need of the assay is greatest. (author)

  3. Preparation of ( sup 123 I)- and ( sup 125 I)epidepride: a dopamine D-2 receptor antagonist radioligand

    Energy Technology Data Exchange (ETDEWEB)

    Clanton, J.A.; Schmidt, D.E.; Ansari, M.S.; Manning, R.G.; Kessler, R.M. (Vanderbilt Univ., Nashville, TN (United States). School of Medicine); Paulis, T. de (Vanderbilt Univ., Nashville, TN (United States). School of Medicine Vanderbilt Univ., Nashville, TN (United States). Dept. of Chemistry); Baldwin, R.M. (Yale Univ., West Haven, CT (United States). Veterans Administration Medical Center Research)

    1991-07-01

    (S)-(-)-N-((1-ethyl-2-pyrrolidinyl)methyl)-5-({sup 123}I) iodo-2,3-dimethoxybenzamide (TDP 517) (proposed generic name, ({sup 123}I)epidepride) is the iodine-123 substituted analogue of isoremoxipride (FLB 457), both of which are very potent dopamine D-2 antagonists (epidepride K{sub D} 0.024 nM). ({sup 123}I) Epidepride was radioiodinated in 60-70% radiochemical yields in 35 min from the corresponding 5-(tributyltin) derivative using Na{sup 123}I with a specific radioactivity of 3000 Ci/mmol, and oxidized in situ with chloramine-T. The aryltin precursor was prepared from non-labelled epidepride by palladium-catalyzed stannylation using bis(tri-n-butyltin) in triethylamine. Alternatively, using no carrier-added Na{sup 125}I as the radioisotope, ({sup 125}I) epidepride at 2000 Ci/mmol specific radioactivity was prepared in 86% radiochemical yield and 99% radiochemical purity after purification by reverse phase HPLC in ethanolic phosphate buffer. (author).

  4. Asthma is more prevalent in elite swimming adolescents despite better mental and physical health.

    Science.gov (United States)

    Romberg, K; Tufvesson, E; Bjermer, L

    2012-06-01

    An increased risk of developing asthma has been reported among swimmers exposed to chloramine in pool arenas. The aim of the present study was to compare the prevalence of asthma and respiratory symptoms among elite aspiring swimmers compared with age-matched controls with different degrees of physical activity. We also aimed to relate these findings to mental and psychosocial factors. One hundred and one elite swimmers and 1628 age-matched controls answered a questionnaire containing questions about respiratory symptoms, lifestyle factors, mental and physical well-being. The controls were divided into three different groups according to the degree of physical activity, no physical activity, recreational training and elite training. Swimmers reported significantly more asthma symptoms, with 36.6% having physician-diagnosed asthma, compared with 16.2% among the controls. Use of regular medication was more common (14.9% vs 8.0%) and more swimmers reported an exacerbation of their asthma during the previous 12 months (16.8%) vs (5.8%) for the controls. Despite an increased prevalence of asthma symptoms, the swimmers reported best physical performance and best mental and physical well-being. They also had a healthier lifestyle without smoking and low alcohol consumption. PMID:20807384

  5. Removal of the cyanotoxin anatoxin-a by drinking water treatment processes: a review.

    Science.gov (United States)

    Vlad, Silvia; Anderson, William B; Peldszus, Sigrid; Huck, Peter M

    2014-12-01

    Anatoxin-a (ANTX-a) is a potent alkaloid neurotoxin, produced by several species of cyanobacteria and detected throughout the world. The presence of cyanotoxins, including ANTX-a, in drinking water sources is a potential risk to public health. This article presents a thorough examination of the cumulative body of research on the use of drinking water treatment technologies for extracellular ANTX-a removal, focusing on providing an analysis of the specific operating parameters required for effective treatment and on compiling a series of best-practice recommendations for owners and operators of systems impacted by this cyanotoxin. Of the oxidants used in drinking water treatment, chlorine-based processes (chlorine, chloramines and chlorine dioxide) have been shown to be ineffective for ANTX-a treatment, while ozone, advanced oxidation processes and permanganate can be successful. High-pressure membrane filtration (nanofiltration and reverse osmosis) is likely effective, while adsorption and biofiltration may be effective but further investigation into the implementation of these processes is necessary. Given the lack of full-scale verification, a multiple-barrier approach is recommended, employing a combination of chemical and non-chemical processes. PMID:25473970

  6. Disinfection by-product formation during seawater desalination: A review.

    Science.gov (United States)

    Kim, Daekyun; Amy, Gary L; Karanfil, Tanju

    2015-09-15

    Due to increased freshwater demand across the globe, seawater desalination has become the technology of choice in augmenting water supplies in many parts of the world. The use of chemical disinfection is necessary in desalination plants for pre-treatment to control both biofouling as well as the post-disinfection of desalinated water. Although chlorine is the most commonly used disinfectant in desalination plants, its reaction with organic matter produces various disinfection by-products (DBPs) (e.g., trihalomethanes [THMs], haloacetic acids [HAAs], and haloacetonitriles [HANs]), and some DBPs are regulated in many countries due to their potential risks to public health. To reduce the formation of chlorinated DBPs, alternative oxidants (disinfectants) such as chloramines, chlorine dioxide, and ozone can be considered, but they also produce other types of DBPs. In addition, due to high levels of bromide and iodide concentrations in seawater, highly cytotoxic and genotoxic DBP species (i.e., brominated and iodinated DBPs) may form in distribution systems, especially when desalinated water is blended with other source waters having higher levels of organic matter. This article reviews the knowledge accumulated in the last few decades on DBP formation during seawater desalination, and summarizes in detail, the occurrence of DBPs in various thermal and membrane plants involving different desalination processes. The review also identifies the current challenges and future research needs for controlling DBP formation in seawater desalination plants and to reduce the potential toxicity of desalinated water. PMID:26099832

  7. [Inactivation of the chlorine-resistant bacteria isolated from the drinking water distribution system].

    Science.gov (United States)

    Chen, Yu-Qiao; Duan, Xiao-Di; Lu, Pin-Pin; Wang, Qian; Zhang, Xiao-Jian; Chen, Chao

    2012-01-01

    Inactivation experiments of seven strains of chlorine-resistant bacteria, isolated from a drinking water distribution system, were conducted with four kinds of disinfectants. All the bacteria showed high resistance to chlorine, especially for Mycobacterium mucogenicum. The CT value of 99.9% inactivation for M. mucogenicum, Sphingomonas sanguinis and Methylobacterium were 120 mg x (L x min)(-1), 7 mg x (L x min)(-1) and 4 mg x (L x min)(-1), respectively. The results of inactivation experiments showed that chlorine dioxide and potassium monopersulfate could inactive 5 lg of M. mucogenicum within 30 min, which showed significantly higher efficiency than free chlorine and monochloramine. Free chlorine was less effective because the disinfectant decayed very quickly. Chloramination needed higher concentration to meet the disinfection requirements. The verified dosage of disinfectants, which could effectively inactivate 99.9% of the highly chlorine-resistant M. mucogenicum within 1 h, were 3.0 mg/L monochloramine, 1.0 mg/L chlorine dioxide (as Cl2), and 1.0 mg/L potassium monopersulfate (as Cl2). It was suggested that the water treatment plants increase the concentration of monochloramine or apply chlorine dioxide intermittently to control the disinfectant-resistant bacteria. PMID:22452196

  8. Treatment of poly- and perfluoroalkyl substances in U.S. full-scale water treatment systems.

    Science.gov (United States)

    Appleman, Timothy D; Higgins, Christopher P; Quiñones, Oscar; Vanderford, Brett J; Kolstad, Chad; Zeigler-Holady, Janie C; Dickenson, Eric R V

    2014-03-15

    The near ubiquitous presence of poly- and perfluoroalkyl substances (PFASs) in humans has raised concerns about potential human health effects from these chemicals, some of which are both extremely persistent and bioaccumulative. Because some of these chemicals are highly water soluble, one major pathway for human exposure is the consumption of contaminated drinking water. This study measured concentrations of PFASs in 18 raw drinking water sources and 2 treated wastewater effluents and evaluated 15 full-scale treatment systems for the attenuation of PFASs in water treatment utilities throughout the U.S. A liquid-chromatography tandem mass-spectrometry method was used to enable measurement of a suite of 23 PFASs, including perfluorocarboxylic acids (PFCAs) and perfluorosulfonic acids (PFSAs). Despite the differences in reporting levels, the PFASs that were detected in >70% of the source water samples (n = 39) included PFSAs, perfluorobutane sulfonic acid (74%), perfluorohexane sulfonic acid (79%), and perfluorooctane sulfonic acid (84%), and PFCAs, perfluoropentanoic acid (74%), perfluorohexanoic acid (79%), perfluoroheptanoic acid (74%), and perfluorooctanoic acid (74%). More importantly, water treatment techniques such as ferric or alum coagulation, granular/micro-/ultra- filtration, aeration, oxidation (i.e., permanganate, ultraviolet/hydrogen peroxide), and disinfection (i.e., ozonation, chlorine dioxide, chlorination, and chloramination) were mostly ineffective in removing PFASs. However, anion exchange and granular activated carbon treatment preferably removed longer-chain PFASs and the PFSAs compared to the PFCAs, and reverse osmosis demonstrated significant removal for all the PFASs, including the smallest PFAS, perfluorobutanoic acid. PMID:24275109

  9. Effect of bipolar electrode material on the reclamation of urban wastewater by an integrated electrodisinfection/electrocoagulation process.

    Science.gov (United States)

    Llanos, Javier; Cotillas, Salvador; Cañizares, Pablo; Rodrigo, Manuel A

    2014-04-15

    This work presents an integrated electrodisinfection/electrocoagulation (ED-EC) process for urban wastewater reuse that employs iron bipolar electrodes. Boron doped diamond (BDD) was used as the anode and stainless steel (SS) as the cathode. A perforated iron plate was introduced between the anode and cathode to function as a bipolar electrode. This ED-EC combined cell makes it possible to conduct the simultaneous removal of microbiological content and elimination of turbidity from urban wastewater. The results show that current densities greater than or equal to 6.70 A m(-2) enable complete disinfection of the effluent and the removal of more than 90% of its initial turbidity. Hypochlorite and chloramines formed during the ED-EC process were found to be the main compounds responsible for the disinfection process. Furthermore, a cell configuration of cathode (inlet)-anode (outlet) improves the process performance by enhancing turbidity removal. Finally, the influence of the bipolar electrode material (iron or aluminium) was assessed. The results indicate that the efficiency of the electrodisinfection process depends mainly on the anodic material and is not influenced by the material of the bipolar electrode. In contrast, the removal of turbidity is more efficient when using iron as a bipolar electrode, especially at low current densities, due to the formation of a passive layer on the aluminium that hinders the dissolution of the bipolar electrode. PMID:24531029

  10. The transport of humic and fulvic acids through sand

    International Nuclear Information System (INIS)

    The objective of this work was to produce stable iodine-125 labelled humic and fulvic acids for use in field tests at the BGS borehole array at Drigg in Cumbria. The first part of the report describes iodine-125 labelling of humic and fulvic acids by oxidation of iodide-125 by chloramine-T. Although the apparent efficiency of labelling was high, some of the iodinated humic dissociated on standing and during passage through sand columns. The second part of the report describes the production of a more stable iodinated humic and fulvic acid. This was achieved by adding reducing agent to the reaction mixture after iodination of the humic material. The addition of reducing agent decreased the apparent labelling efficiency of the humic materials but increased the stability. The third part of the report describes the preparation of iodinated-fulvic acid for use in a field test. Gel column separation showed that 95% of the activity was bound to fulvic acid on the day of the field experiment. Samples of this material were passed through 55 cm long sand columns. I-125 breakthrough occurred simultaneously with tritium but a proportion remained on the column. This sorbed, or deposited, material then eluted very slowly from the column. (author)

  11. A radioimmunoassay of chicken growth hormone using growth hormone produced by recombinant DNA technology: validation and observations of plasma hormone variations in genetically fat and lean chickens

    International Nuclear Information System (INIS)

    A radioimmunoassay (RIA) of chicken growth hormone (c-GH) has been developed using growth hormone produced by recombinant DNA technology. The best rabbit antiserum was used at 1/300,000 final dilution. Hormone labelling by iodine-125, achieved by chloramine T, allowed a specific activity of 3.7 MBq/μg. The equilibrium curves show that optimal conditions of incubation were reached at room temperature for 24h. This RIA used a second sheep antibody which precipitated the whole c-GH bound to the first antibody in the presence of polyethylene glycol solution (6%) at room temperature for 30 min. In our conditions, sensitivity was about 30 pg of c-GH per tube. Coefficient of variation was around 10%. No cross reaction was found with avian LH and prolactin. Thyrotrophin-releasing hormone (TRH) injection to young chickens induced 20-fold higher plasma c-GH concentrations. Simultaneous injection of somatostatin and TRH slightly reduced these concentrations. Hypoglycemia induced by insulin led to a drop of the plasma c-GH concentration. Conversely, refeeding or glucose load induced slight increases of the c-GH level. Genetically fat chickens tended to exhibit higher plasma c-GH concentrations than lean chickens

  12. iodine 125 -tamoxifen (125ITX); radioligand for visualization of estrogen receptors: preparation and tissue distribution

    International Nuclear Information System (INIS)

    Tamoxifen,(Z) 2-[4-(1,2-diphenyl-1-butenyl) phenoxy] -N,N-dimethylethethanamine 2-hydroxy-1,2,3-propane tricarboxylate (TX) is a selective estrogen receptor antagonist for use in the treatment of breast cancer and other non-malignant estrogen dependant conditions. direct radioiodination of tamoxifen was done using chloramine-t as oxidizing agent and yielded 97% of 125ITX. the reaction mixture was heated at 50 c for 10 minutes . the ph of the reaction mixture was the most critical factor during this labeling reaction . iodine -125-tamoxifen was localized in the organs of interest with a percentage sufficient to produce a good image whereas their ratios to backgrounds were high (9.1 for breast/blood,6.4 for ovaries an uterus/blood at 8 h post injection). 125ITX was cleared by both the kidneys and the liver. at 8 post injection the excretion in urine was 28.5% and that in faeces was 22% . the thyroid uptake was very low (0.1%) indicating the in - vivo stability of 125ITX tracer. a specificity of the tracer to the breast and ovaries/uterus was established via prior administration of cold tamoxifen and estradiol that significantly reduced the localizing activity of the tracer

  13. Iodine-125 Nilutamide as Novel Radio-therapeutic Ligand for Androgen Receptor in Prostate Cancer

    International Nuclear Information System (INIS)

    Nilutamide is potent anti-androgen that is used in patients with metastatic prostate carcinoma. The labeling of nilutamide with iodine radioisotopes give an advantage to localize these radionuclides in prostate for imaging and/or therapy depending on the radionuclide used. During this study, nilutamide was labeled successfully with iodine-125 in a neutral ph medium using chloramine-T as oxidizing agent and the radiochemical yield obtained was greater than 96%. The biodistribution of the iodine-125-nilutamide in normal mice indicated the ability of the tracer to bind with specific receptors in prostate and other male organs with 3.5 % at 4 hours post injection. The clearance of the tracer from the blood pool was slow and equal to 40% of the initial blood uptake at 4 hours post injection. The in vivo stability of the tracer was established by the absence of the thyroid uptake. The competition binding was achieved via 1M injection of testosterone and IV injection of non-labeled nilutamide 2 hours before the administration of the tracer. The results referred to a significant reduction in the uptake of the tracer by the prior administration of testosterone and non-labeled nilutamide by 60% and 30%, respectively at 4 hours post injection

  14. Immunoradiometric assay of subunit H of human acidic isoferritin

    International Nuclear Information System (INIS)

    Acidic isoferritin (AIF) was isolated and purified from human heart muscle. Antisera against AIF were generated by immunizing rabbits and purified in affinity chromatography column which was conjugated with AIF. The immunoglobulins against AIF were made in solid-phase. 125I-monoclonal antibodies against H subunit of AIF(AIF-H) was prepared by the chloramine-T method. The AIF-H solid-phase IRMA was established and the data were processed by the automatic Spline function. The intra- and interbatch coefficients of variation were 2.443% and 10.160% respectively. The sensitivity was 0.736 μg/L and the recovery was 92.293%. The measuring range was 1.472-320 μg/L and ED50 was 23.05 μg/L. No cross-reaction was observed with AFP, CEA and LF, but there was 3.125% with ferritin. A parallel experiment demonstrated that serum matrix had no interference with this method. The level of serum AIF-H in 40 healthy men and women was 3.75 +- 1.85 μg/L and 2.92 +- 0.96 μg/L respectively while it was 8.39 +-3.87 μg/L in 10 patients with hepatoma. This method may therefore provide a valuable tool for diagnosis of tumor, especially for basic and clinical study of hepatoma

  15. Establishment of RIA for human obestatin and its primary application

    International Nuclear Information System (INIS)

    To establish a RIA method for human Obestatin and find out the expression changes and meaning of Obestatin during metabolic disorder diseases, synthetic human Obestatin was immunized and obtained anti-serum and chloramines-T method was used to radiolabel Obestatin with 125I, thus a RIA for Obestatin was established. The serum Obestatin levels of 50 patients with coronary heart disease, 50 patients with diabetes and in 50 healthy controls were determined by using self-established RIA. The results showed that both the shape of standard curve and metrical results of the Obestatin RIA established in this study were well. The serum Obestatin levels in patients with diabetes and coronary heart disease were significantly higher than that of healthy controls (P<0.001), while the serum Obestatin levels in patients with coronary heart disease were significantly higher than that of patients with diabetes (P<0.001). The results suggested that the established human Obestatin RIA was highly sensitive, concise and reliable. It can be used to detect human serum samples. The Obestatin may be a stress factor participating in the modulation of metabolic disorder diseases. (authors)

  16. Solid Phase Radioimmunoassay for Measuring Serum Triiodothyronine and Thyroxine using Different Preparations of Their Labeled Hormones

    International Nuclear Information System (INIS)

    The goal of the present work was oriented to prepare stable polystyrene coated tubes for direct radioimmunoassay (RIA) of triiodothyronine (T3) and thyroxine (T4) in human serum or plasma. Coating process was performed using sheep polyclonal antisera specific for each of T3 and T4. The stability study showed that these tubes could be stored for up to one year at 4 degree without any appreciable reduction in their binding. The preparations of 25I-T3 and 125I-T4 were carried out by two different methods [chloramine-T(Ch-T) and iodogen] . It was found that Ch-T method gave approximately the same results as iodogen method. Twenty five samples of different thyroid status were assayed for T3 and T4 using the present systems and with commerically available kits (coated tubes, DPC). The statistical analysis revealed good correlations between the results from the present systems using T3 and T4 tracers prepared by Ch-T and iodogen methods and The DPC kits. This may be extremely helpful in diagnosis and proper management of thyroid dysfunctions

  17. Comparison of fipronil sources in North Carolina surface water and identification of a novel fipronil transformation product in recycled wastewater.

    Science.gov (United States)

    McMahen, Rebecca L; Strynar, Mark J; McMillan, Larry; DeRose, Eugene; Lindstrom, Andrew B

    2016-11-01

    Fipronil is a phenylpyrazole insecticide that is widely used in residential and agricultural settings to control ants, roaches, termites, and other pests. Fipronil and its transformation products have been found in a variety of environmental matrices, but the source[s] which makes the greatest contribution to fipronil in surface water has yet to be determined. A sampling effort designed to prioritize known fipronil inputs (golf courses, residential areas, biosolids application sites and wastewater facilities) was conducted in North Carolina to learn more about the origins of fipronil in surface water. High resolution mass spectrometry (HRMS) analysis indicated that fipronil and its known derivatives were routinely present in all samples, but concentrations were substantially elevated near wastewater treatment plant outfalls (range 10-500ng/L combined), suggesting that they predominate as environmental sources. Corresponding recycled wastewater samples, which were treated with NaOCl for disinfection, showed disappearance of fipronil and all known degradates. HRMS and nuclear magnetic resonance (NMR) analysis techniques were used to determine that all fipronil-related compounds are oxidized to a previously unidentified fipronil sulfone chloramine species in recycled wastewater. The implications of the presence of a new fipronil-related compound in recycled wastewater need to be considered. PMID:27378152

  18. Iodine-123 labeled derivatives of methylphenidate: potential SPECT radiopharmaceuticals for brain dopamine transporters

    International Nuclear Information System (INIS)

    Since dl-threo-[11C]methylphenidate (Ritalin) and especially the more active enantiomer, d-threo-[11C]methylphenidate, have favorable properties for PET studies, we prepared two radioiodinated analogs of methylphenidate, p-[123I]iodomethylphenidate and m-[123I]iodo-p-hydroxymethylphenidate with a view to evaluating them as potential SPECT tracers. To prepare p-[123I]iodomethylphenidate, the p-tributyltin derivative was prepared from the previously reported p-bromomethylphenidate and reacted under acidic conditions with I-123 iodide plus chloramine-T at room temperature for 90 seconds. The predomimant radioactive product was obtained in 85% radiochemical yield and > 10 Ci/μmol specific radioactivity after HPLC purification. It had the same HPLC retention time as a spectroscopically characterized non-radioactive p-iodomethylphenidate standard prepared via nitration of methylphenidate and diazotization, after protection of the secondary amino group by benzoylation. A second radioiodinated methylphenidate derivative, m-[123)I]iodop-hydroxymethylphenidate was prepared in 80% radiochemical yield by direct iodination of the known p-hydroxymethylphenidate. In this case the non-radioactive standard was prepared by iodination of p-hydroxyritalinic acid using I2 and iodic acid, followed by esterification. (author)

  19. Human C-peptide. Pt. 1

    International Nuclear Information System (INIS)

    Synthetic human C-peptide bearing a tyrosine group at its amino end is labelled with 125iodine using chloramin T or hydrogen peroxide and lactoperoxidase. The results of the two methods are compared. Antiserum to synthetic human C-peptide (without tyrosine), which was partially coupled to rabbit albumin, is raised in guinea pigs and goats. Goats show to be superior to guinea pips concerning antibody production. The so-called 'hook effect' phenomenon is observed when setting up the standard curves for the radioimmunoassay. Monotonically decreasing standard curves are obtained on dilution of antiserum with a high antibody titer which was produced by repeated immunization in goats. Free C-peptide and C-peptide bound to antiserum are separated using the anion exchange resin amberlite. Using this separation technique we excluded unspecific binding of labelled C-peptide to protein fractions in serum of diabetics. The sensitivity of our radioimmunoassay is approx. 0.3 ng C-peptide/ml serum. Intra- and interassay variability are below 10%. Human proinsulin is the only substance found to crossreact with the antiserum. (orig.)

  20. Measurement of insulin in human sera using a new RIA kit. 1

    International Nuclear Information System (INIS)

    A sensitive and versatile radioimmunoassay (RIA) for insulin was established using human insulin standard, a specific guinea pig anti-insulin antiserum and rabbit anti-guinea pig serum. Radioiodination was performed according to a modified chloramine T method. Tracer preparations were used for as long as 6 weeks after iodination. The standard curve ranges from 0.044 to 1.2 nmol/l. The intra-assay coefficient of variation (CV) was 3-5% and the inter-assay CV was 6-9% in the optimal range between 0.4 and 0.9 nmol/l. The average recovery of human insulin added to plasma or serum samples was 100.2 ± 2.0% (n = 38) and 100.1 ± 1.9% (n = 42), respectively. In addition to human insulin, procine, canine, rabbit and bovine insulin can also be determined but not rat or mouse insulin. The cross-reactivity of the antiserum with porcine proinsulin was found to be 40 % on the molar basis. The range of mean fasting plasma insulin concentrations in healthy subjects and under various pathological conditions were estimated. (author)

  1. Clinical scale preparation and evaluation of {sup 131}I-Rituximab for Non-Hodgkin's lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Kameswaran, Mythili; Vimalnath, K. Viswanathan; Rajeswari, Ardhi; Joshi, Prahlad Vasudeo; Samuel, Grace [Bhabha Atomic Research Centre, Mumbai (India). Radiopharmaceuticals Div.; Sarma, H.D. [Bhabha Atomic Research Centre, Mumbai (India). Radiation Biology and Health Sciences Div.

    2014-09-01

    Radioimmunotherapy (RIT) with anti CD20 MoAb conjugated to a β{sup -} emitting radioisotope like {sup 131}I or {sup 90}Y has the added advantage of delivering radiation not only to tumor cells that bind the antibody but also due to a crossfire effect, to neighboring tumor cells inaccessible to the antibody. In order to make available an indigenous radioimmunotherapeutic agent for Non Hodgkin's Lymphoma (NHL), radioiodinated Rituximab has been prepared and evaluated at a clinical scale. Radioiodination of Rituximab was performed by the conventional Chloramine T method using 7.4 GBq Na{sup 131}I in a lead shielded plant. Six batches of radioiodination were prepared and characterized by electrophoresis and HPLC to evaluate the reproducibility of the product. The product remained stable retaining the radiochemical purity > 95% upto 5 days after radioiodination. In vitro cell binding studies and biodistribution studies in normal Swiss mice have indicated the potential of this molecule as a radioimmunotherapeutic agent for NHL. (orig.)

  2. Treatment of ichthyophthiriasis after malachite green. I. Concrete tanks at salmonid farms.

    Science.gov (United States)

    Rintamäki-Kinnunen, Päivi; Rahkonen, Mika; Mannermaa-Keränen, Anna-Liisa; Suomalainen, Lotta-Riina; Mykrä, Heikki; Valtonen, E Tellervo

    2005-04-01

    Since the use of malachite green was banned in many European countries, new alternative treatments have been tested to prevent white spot disease caused by Ichthyophthirius multifiliis. We tested formalin, potassium permanganate (KMnO4), chloramine-T, hydrogen peroxide (H2O2) and Per Aqua or Desirox alone or in combinations of 2 chemicals, one of which was always formalin, in 50 m2 concrete tanks at 2 farms producing salmon Salmo salar smolt in 2001 and 2002. Both Per Aqua and Desirox are combinations of peracetic acid, acetic acid and hydrogen peroxide. The alternative chemicals or their combinations can be used successfully to lower the parasite burden to such a level that no high mortality occurs during the first 4 wk after the start of an infection. This period of time allows the fish to develop immunity against these ciliates, and treatments can be reduced and stopped in due course. I. multifiliis decreased in number 3 to 4 wk after the beginning of the infection in all the treatments. Large differences in parasite burden and mortality occurred among the replicates in all except the Desirox-formalin tanks, which means that they are not as reliable as the malachite green-formalin used previously. It was also evident that the chemicals and their concentrations must be planned carefully to suit the conditions on each farm. PMID:15900690

  3. Powerful colloidal silver nanoparticles for the prevention of gastrointestinal bacterial infections

    Science.gov (United States)

    Le, Anh-Tuan; Tam Le, Thi; Quy Nguyen, Van; Hoang Tran, Huy; Dang, Duc Anh; Tran, Quang Huy; Vu, Dinh Lam

    2012-12-01

    In this work we have demonstrated a powerful disinfectant ability of colloidal silver nanoparticles (NPs) for the prevention of gastrointestinal bacterial infections. The silver NPs colloid was synthesized by a UV-enhanced chemical precipitation. Two gastrointestinal bacterial strains of Escherichia coli (ATCC 43888-O157:k-:H7) and Vibrio cholerae (O1) were used to verify the antibacterial activity of the as-prepared silver NPs colloid by means of surface disinfection assay in agar plates and turbidity assay in liquid media. Transmission electron microscopy was also employed to analyze the ultrastructural changes of bacterial cells caused by silver NPs. Noticeably, our silver NPs colloid displayed a highly effective bactericidal effect against two tested gastrointestinal bacterial strains at a silver concentration as low as ∼3 mg l‑1. More importantly, the silver NPs colloid showed an enhancement of antibacterial activity and long-lasting disinfectant effect as compared to conventional chloramin B (5%) disinfection agent. These advantages of the as-prepared colloidal silver NPs make them very promising for environmental treatments contaminated with gastrointestinal bacteria and other infectious pathogens. Moreover, the powerful disinfectant activity of silver-containing materials can also help in controlling and preventing further outbreak of diseases.

  4. Disinfection by-products effect on swimmers oxidative stress and respiratory damage.

    Science.gov (United States)

    Llana-Belloch, Salvador; Priego Quesada, Jose Ignacio; Pérez-Soriano, Pedro; Lucas-Cuevas, Ángel G; Salvador-Pascual, Andrea; Olaso-González, Gloria; Moliner-Martinez, Yolanda; Verdú-Andres, Jorge; Campins-Falco, Pilar; Gómez-Cabrera, M Carmen

    2016-08-01

    Disinfection by-products (DBPs) are generated through the reaction of chlorine with organic and inorganic matter in indoor swimming pools. Different DBPs are present in indoor swimming pools. This study evaluated the effects of different chlorinated formations in oxidative stress and lung damage in 20 swimmers after 40 min of aerobic swimming in 3 indoor pools with different characteristics. Biological samples were collected to measure lung damage (serum-surfactant-associated proteins A and B), oxidative stress parameters (plasma protein carbonylation and malondialdehyde, and whole-blood glutathione oxidation), and swimming exertion values (blood lactate) before and after exercise. Free chlorine and combined chlorine in water, and chlorine in air samples were determined in all the swimming pools. Chlorination as disinfection treatment led to the formation of chloramines in water samples, mainly mono- and dichloramine. However, free chlorine was the predominate species in ultraviolet-treated swimming pool. Levels of total chlorine increased as a function of the swimming activity in chlorinated swimming pools. The lower quality of the installation resulted in a higher content of total chlorine, especially in air samples, and therefore a higher exposure of the swimmer to DBPs. However, the concentration level of chlorinated DBPs did not result in significant variation in serum-surfactant-associated proteins A and oxidative stress parameters in swimmers. In conclusion, the quality of the installation affected the DBPs concentration; however, it did not lead to lung epithelial damage and oxidative stress parameters in swimmers. PMID:26364906

  5. Iodine-125 Chitosan-Vitamin C complex. Preparation, characterization and application

    International Nuclear Information System (INIS)

    In heterogeneous conditions, water soluble Chitosan-Vitamin C Complex (CSVC) is successfully synthesized via the ionic interaction between γ-degraded CS and VC. Chitosan (CS) of low molecular weight (MW) is prepared using γ-irradiation method. The coupling of CS and vitamin C (VC) is carried out by the chemical treatment of VC with the γ-degraded CS. The formation of CSVC complex instead of physical mixture is confirmed by FT-IR and UV spectrometry. Characterization by transmission electron microscope (TEM) and dynamic light scattering (DLS) shows the formation of a nanostructure in 40 nm range. The preparation of labeled CSVC was performed using chloramines-T oxidation method. The labeling feasibility of CSVC nanostructure by Iodine-125 (125I) is investigated. The optimized conditions of labeling are thought to be 50 μg of oxidizing agent, pH 3, and one minute reaction time. The Biodistribution activity of 125I radiolabeled CSVC nanostructure (125I-CSVC) is examined on a group of different ascites tumor bearing mice. Calculation of the biodistribution percentages shows that the tumor, liver, and kidney are the targeting organs of 125I-CSVC nanostructure.

  6. Radioimmunoassay of TSH subunits in thyroid diseases and endocrine opthalmopahty

    International Nuclear Information System (INIS)

    Highly sensitive radioimmunoassays of hTSH sub-units were developed. The hormone preparations were labelled with 125-iodine according to a modified chloramine -T method, and purified by chromatography using biogel P6 and P60. Rabbit antisera were used as antibodies. Separation of the antibody-bound and of the free antigens was carried out via the double antibody method. The antiserum required for this purpose was obtained from a goat. The sensitivity of the assay was influenced by changing the protein content of the buffer, the incubation volume, the tracer amounts, the incubation time and the incubation temperature. For hTSH-α, the lowest detectable limit was found to be 50 pg/ml, for hTSH-#betta# 20 pg/ml. Thus, the sub-units could be determined for 98% of the patients under review. The #betta#-TSH radioimmunoassay is largely specific, TSH cross-reacts to a degree of 5%. The computerized evoluation was carried out by means of Spline approximation using the Siemens 4004 computer. Precision and accurateness are in compliance with generally accpted criteria. The serum levels of α and #betta# sub-units showed no discordancy with regard to TSH. In all groups of patients examined, the levels of the hormone-specific #betta#-chain were found to be exclusively dependent upon the actual thyroid activity. (orig.)

  7. Relationship between PLAP and high-risk pregnancy

    International Nuclear Information System (INIS)

    PLAP was isolated and purified from human placenta and the antiserum was obtained by immunizing the rabbits. A radioimmunoassay of PLAP (PLAP RIA) was established by labelling the antigen using the chloramine-T method. Its sensitivity was 1.54 μg/L, the recovery rate was between 96.7% and 105.2%, the intra- and inter-assay CV were 8.94% and 9.43%, respectively, the antiserum provided a linear response from 2 to 1000 μg/L. The assay has no cross-reactivity with liver AP. Serum level of PLAP were measured by PLAP RIA in 649 cases of normal pregnancy and 164 cases of high-risk pregnancy. The results indicated that the PLAP level increased proportionally with the advance of gestational age (r = 0.9843). In 33 cases of pregnancy induced hypertension and 21 cases of intrauterine fetal growth retardation, the PLAP were at significantly low level. In 7 cases of neonatal asphyxia and 26 cases of fetal distress, the PLAP level in the mother's serum were also low. In 53 cases of intrahepatic cholestasis of pregnancy, the PLAP level were similar to those of normal pregnancy. This study illustrated that PLAP RIA can play an important role in evaluation of placental function and fetal prognosis for cases of high-risk pregnancy

  8. Development of an 'In vitro' system for the caption essay of T3

    International Nuclear Information System (INIS)

    Triiodothyronine uptake (T3U) is a qualitative technique for evaluation of the unsaturation capacity of thyroid binding globulin (TBG). This paper presents results related to a T3 standardized serum and the integration of T3-I-125, and adsorbent for labelled hormone. Labelled hormone were prepared by the chloramine T method and then purified by high performance liquid chromatography. The specific activity was 500 μ Ci/ μ g. Various adsorbents such as: Norit A Charcoal, calcium silicate, talc, bovine serum albumin macroaggregated (BSAM) were used in different buffers as: Tris-HCl, barbital and Michaelis. Standardized serum was prepared by mixing different euthyroid sera. Best conditions for T3U assays were achieved with 15 mg/ml. BSAM at pH 8.6 in presence of Tris-HCl buffer for hypothyroid and hyperthyroid sera, for which we obtained 1.1 ± 0.05 respectively as a T3U index with a 3.0 % of coefficient variation. The reagents so prepared can be conveniently used for T3U assays. (Author)

  9. High levels of total ammonia nitrogen as NH4+ are stressful and harmful to the growth of Nile tilapia juveniles - doi: 10.4025/actascibiolsci.v35i4.17291

    Directory of Open Access Journals (Sweden)

    Francisco Jackes Rodrigues da Silva

    2013-07-01

    Full Text Available This study determined whether high levels of total ammonia nitrogen (TAN as NH4+ are harmful to the growth performance of Nile tilapia juveniles. Fingerlings (0.31 ± 0.04 g were assigned to 30 polyethylene 100-L tanks in a roofed room for 12 rearing weeks. There were increasing levels of TAN by increased NH4Cl application rates (0.0; 0.25 and 0.50 g tank-1 week-1 at three conditions of water pH (acidic, 6.2 ± 0.5; neutral, 7.2 ± 0.8 and alkaline, 8.8 ± 0.3. The application of HCl to acidic tanks caused 100% of TAN to be converted into NH4+. The poorest growth performance results were observed for the alkaline tanks subjected to the highest application of NH4Cl. In acidic tanks, fish survival has dropped in those tanks under the highest application rate of NH4Cl. Tilapia growth was lower in neutral tanks when the NH4Cl application rate increased to 0.50 g tank-1 week-1. It was concluded that waterborne ionized ammonia (NH4+ is indirectly toxic to tilapia due to the harmful metabolites derived from it, such as nitrite and chloramines as well as due to water acidification.

  10. Evaluation of 3-[123I]iodo- and 3-[76Br]bromo-methylphenidate as potential tracers for the study of the dopamine transporter using SPECT and PET

    International Nuclear Information System (INIS)

    Full text: The psychomotor stimulant methylphenidate (MP) and several derivatives have demonstrated high affinity binding to a site on the dopamine transporter (DAT). Here we report the pharmacological evaluation of 3-[123I]iodomethylphenidate (l23MP) and 3-[76Br]bromomethyl phenidate (76BrMP) as potential SPET and PET tracers for the study of the DAT. Racemic 123IIMP and 76BrMP were synthesized from the corresponding 3-tributylstannyl methylphenidate using Na123I or NH476Br in the presence of chloramine-T. In vivo biodistribution of the active enantiomers of 123IMP in rats indicated a striatum (STR) to cerebellum (CB) ratio of 2.4 at 30 min p.i. Pretreatment of the rats with MP, WIN 35,428 and GBR 12909 reduced the STR/CB ratio to unity. Similarly, in vivo biodistribution of 76BrMP in rats also indicated high uptake in the striatum with a STR/CB ratio of 5.5 at 120 min p.i. Administration of 123IMP and 76BrMP in primates and examination by SPET and PET indicated a high accumulation of radioactivity in the striatum with rapid washout in other non-dopaminergic tissue. These results indicate that the active enantiomers of 123IMP and of 76BrMP have the potential for further development as SPET and PET tracers for the study of neurodegenerative diseases such as Parkinson's disease

  11. Establishment of 131I, 99mTc Labeling Methods to In-house Anti-CEA Antibodies and Evaluation of the Immunological Characteristics

    International Nuclear Information System (INIS)

    Cancer cells have several tumor-associated antigens on the cell surfaces, and antibodies against these antigens have been developed by many investigators. Radiolabeled antibodies have been used as new methods to diagnose and treat malignant tumors. Especially anti-carcinoembryonic antigen (CEA) is the most popular antibody for these purposes. In this investigation, we tried to label 131I and 99mTc to anti-CEA monoclonal antibodies which were developed in the Seoul National University College of Medicine. We found CEA-79 and CEA-92 antibodies had the better immunological characteristics among 8 anti-CEA monoclonal antibodies. And radioiodination of CEA-79 could be performed by chloramine-T method, while radioiodination of CEA-92 by iodogen method. To label these antibodies with 99mTc, we used pretargeting transchelation as direct labeling method. At first, 99mTc was bound to glucaric acid, and monoclonal antibody was reduced by β-mercaptoethanol. When these were incubated together, 99mTc bound to glucarate was switched to monoclonal antibody because of higher affinity. We established conditions of several steps in this method. Anti-CEA monoclonal antibodies labeled with 131I and 99mTc are expected to be used valuably in the detection and treatment of malignant tumors.

  12. Potential cerebral perfusion agents: synthesis and evaluation of a radioiodinated vinylalkylbarbituric acid analogue

    International Nuclear Information System (INIS)

    A new iodinated barbiturate has been prepared. Treatment of 5-chloropentyne and propargyl bromide with diethyl 2-ethyl-2-sodiomalonate (DESM) provided diethyl 2-ethyl-2-(1-pentyn-5-yl)malonate (3) and diethyl 2-ethyl-2-propargylmalonate (4), respectively. Similar condensation of DESM with (E)-(5-iodo-1-penten-1-yl)boronic acid (9) or the reaction of catecholborane with 3 provided diethyl (E)-2-ethyl-2-(1-borono-1-penten-5-yl)malonate (8). The direct sodium iodide-chloramine-T iodination of 8 or the treatment of (E)-1,5-diiodo-1-pentene (10) with DESM provided diethyl (E)-2-ethyl-2-(1-iodo-1-penten-5-yl)malonate (11). The condensation of functionalized malonates 3, 4, and 11 with urea in the presence of a base provided the corresponding barbiturates, 5-ethyl-5-(1-pentyn-5-yl)-(5), 5-ethyl-5-propargyl- (6), and (E)-5-ethyl-5-(1-iodo-1-penten-5-yl)barbituric acid (12), respectively. (E)-6-(Ethoxycarbonyl)-1-iodo-1-octene-6-carboxylic acid (13) was isolated as the hydrolytic byproduct of 11. Compound 13 decarboxylated under vacuum to provide ethyl (E)-1-iodo-1-octene-6-carboxylate (14). The 125I-labeled congeners of 12 and 13 were synthesized in the same manner and evaluated in rats. The barbiturate 12 exhibited significant brain uptake (approximately 1% dose after 5 min), demonstrating that iodinated barbiturates freely cross the intact blood-brain barrier

  13. Potential cerebral perfusion agents: synthesis and evaluation of a radioiodinated vinylalkylbarbituric acid analogue

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, P.C.; Callahan, A.P.; Cunningham, E.B.; Knapp, F.F. Jr.

    1983-05-01

    A new iodinated barbiturate has been prepared. Treatment of 5-chloropentyne and propargyl bromide with diethyl 2-ethyl-2-sodiomalonate (DESM) provided diethyl 2-ethyl-2-(1-pentyn-5-yl)malonate (3) and diethyl 2-ethyl-2-propargylmalonate (4), respectively. Similar condensation of DESM with (E)-(5-iodo-1-penten-1-yl)boronic acid (9) or the reaction of catecholborane with 3 provided diethyl (E)-2-ethyl-2-(1-borono-1-penten-5-yl)malonate (8). The direct sodium iodide-chloramine-T iodination of 8 or the treatment of (E)-1,5-diiodo-1-pentene (10) with DESM provided diethyl (E)-2-ethyl-2-(1-iodo-1-penten-5-yl)malonate (11). The condensation of functionalized malonates 3, 4, and 11 with urea in the presence of a base provided the corresponding barbiturates, 5-ethyl-5-(1-pentyn-5-yl)-(5), 5-ethyl-5-propargyl- (6), and (E)-5-ethyl-5-(1-iodo-1-penten-5-yl)barbituric acid (12), respectively. (E)-6-(Ethoxycarbonyl)-1-iodo-1-octene-6-carboxylic acid (13) was isolated as the hydrolytic byproduct of 11. Compound 13 decarboxylated under vacuum to provide ethyl (E)-1-iodo-1-octene-6-carboxylate (14). The /sup 125/I-labeled congeners of 12 and 13 were synthesized in the same manner and evaluated in rats. The barbiturate 12 exhibited significant brain uptake (approximately 1% dose after 5 min), demonstrating that iodinated barbiturates freely cross the intact blood-brain barrier.

  14. Development and evaluation of a magnetic solid-phase radioimmunoassay for total human thyroxine (T4)

    International Nuclear Information System (INIS)

    In this study a simple and rapid magnetic solid-phase radioimmunoassay (RIA) for human thyroxine (T4) was developed using locally raised sheep thyroxine antibody and radioiodinated thyroxine (T4) tracer by chloramine-T method. The assay involves two hours incubation at ambient temperature rang (30 to 35 oC) associated with the antibody covalently linked by the easily performed carbonyldiimidazole (CDI) method to magnetic particles obtained from SIPAC. 0.1% triton with sodium azide used as a wash buffer. L-Thyroxine Na-salt peta hydrate from sigma was used for the preparation of standards and quality control sera. The coupled magnetic anti-T4 solid phase titrated in order to find out the suitable antibody concentration (titre) to be used in the assay. Optimizations followed by validation procedures were done. When correlated with kits imported from NETRIA and AMERSHAM, results were found to be highly comparable r=0.965 and p<0.05. Shelf life was also studied, so that the local prepared T4 RIA magnetic reagents can be used for the measurement of total human thyroxine with a very low cost compared to imported kits. (Author)

  15. Radioimmunoassay for determination of alpha subunit of pituitary glycoprotein hormones in patients with pituitary tumors

    International Nuclear Information System (INIS)

    A radioimmunoassay method for alpha subunit has been described and applied for serum alpha subunit determinations in normal subjects and 71 patients with pituitary tumors /45 acromegalic and 26 non-acromegalic/. The labelling of alpha subunit by the chloramine T technique yielded 125I-alpha subunit of high specific activity and high immuno-reactivity. Three purification methods of labelled 125I-alpha subunit were compared; the best separation of undamaged 125I-alpha subunit from impurities was achieved by gel filtration on Ultrogel AcA54 column, whereas gel filtration on Sephadex G-100 and adsorption chromatography on CF-11 cellulose gave less satisfactory results. Microheterogenity of 125I-alpha subunit was disclosed by chromatofocusing on PBE 94; the fractions of high immunoreactivitiy had isoelectric points of 6.0, 5.5 and 4.8. In normal subjects, radioimmunoassay of alpha subunit gave the following results /mean and SD/: 0.75 ng/ml +- 0.41 in males and 0.80 ng/ml +- 0.39 in females in reproductive age. In 9 acromegalic serum alpha subunit concentration were elevated up to 21 ng/ml, and in 8 non-acromegalic up to 30 ng/ml. One woman with acromegaly and high serum alpha subunit concentration had also elevated serum TSH associated with hyperthyroids. Our results disclosed that high serum alpha subunit concentration occurs in 25 % of patients with pituitary adenomas. (Author)

  16. Development and clinical application of human gastrin radioimmunoassay

    International Nuclear Information System (INIS)

    The determination of human gastrin levels in the blood is very important for diagnosis of gastrointestinal disorders. This work describes the radioimmunoassay of gastrin developed according to Russell et al. and its clinical application measuring fasting levels of this hormone in normal subjects, gastrectomized, chagasics, patients with chronic renal failure (CRF), pernicious anemia (PA) and Zollinger-Ellison syndrome (ZES). Synthetic human gastrin was used for radioiodination and as standard, while the specific antibody was raised in rabbits. Gastrin was radioiodinated by a modification of the chloramine T technique and purified by anion exchange chromatography in QAE-Sephadex A-25 to a specific activity around 200 uCi/ug. The assays were performed by incubation of 125I-gastrin, standard gastrin (zero to 500 pmol/l) or unknown samples with the antiserum for 4 days at 40C. The antibody bound and free 125 I-gastrin was separated by adsorption of the latter to the charcoal. The basal gastrin values of normal subjects ranged from 2 to 74 pmol/l, being these levels higher in the chagasics (from 6 to 261 pmol/l). Higher levels of gastrin were determined in patients with CRF (from 12 to 350 pmol/l), PA (from 160 to 680 pmol/l) and with ZES(1010 pmol/l), while very low levels were confirmed in gastrectomized (from 1 to 8 pmol/l). (author)

  17. IRMA for assessment of soluble platelet glycocalicin and its clinical application in coronary heart disease

    International Nuclear Information System (INIS)

    Objective: To establish the immunoradiometric assay (IRMA) method for assessment of soluble platelet glycocalicin (sGC) and its clinical use. Methods: The labeling of 125I-2D4 was by chloramine T method. IRMA method was established for assessment of sGC. The plasma sGC levels of 50 healthy mine T method. IRMA method was established for assessment of sGC. The plasma sGC levels of 50 healthy people, 15 unstable angina (UA) and 37 acute myocardial infraction (AMI) were measured by IRMA. Results: The assaying range was 31.25-2000 μg/L. The sensitivity was 15 μg/L. The intra assay coefficients of variation (CV) were 6.25%, 4.35% and 3.99% (n=6) and the inter assay CV were 8.55%, 4.82% and 4.48% for 50, 300, 1800 μg/L, respectively. The average recovery rate was 101/88%. The plasma sGC level in normal group was (824.50 ± 225.11) μg/L. The plasma sGC levels in both UA and AMI groups were significantly higher than that in normal group (P<0.01). Coxregression analysis revealed that sGC was significantly correlated with P-selectin in AMI and UA groups (r=0.652, P<0.01). Conclusion: The sGC may be an important molecular marker of platelet activation and destruction. (authors)

  18. Comparison of three radioligands, selenium-75, iodine-125, and tritium, in the radioimmunoassay of methotrexate

    International Nuclear Information System (INIS)

    Radioimmunoassays for methotrexate are described, involving use of a rabbit antiserum to a conjugate of the drug and bovine serum albumin and the drug labeled with tritium, selenium-75, or iodine-125. Of the two gamma emitters, the 75Se-labeled drug was prepared by the Radiochemical Centre, Amersham, England and the 125I-labeled drug in the laboratory, by the Chloramine T iodination technique. The stability of labels with both methods allows use of the faster, cheaper, and simpler gamma-counting techniques, with results available after 3 h. All three methods have acceptable sensitivity, accuracy, precision, and reproducibility, and are specific for methotrexate, with no significant interference from naturally occurring folates or leucovorin. The assays in which the gamma emitters are used have significant practical advantages over the beta emitter and are much better suited to automation and clinical application. The main advantage of 75Se-labeled methotrexate is its longer half-life, 121 days, as compared with 60 days for 125I

  19. Development of Solid Phase Radioimmunoassay for Measuring Methotrexate and 7-Hydroxy Methotrexate in Biological Fluids using Magnetizable Particles

    International Nuclear Information System (INIS)

    The objective of the present study was to prepare a solid phase magnetic particles radioimmunoassay (RIA) reagents. Development as well as optimization and validation of RIA system for the assessment of methotrexate (MTX) and its main metabolite 7-hydroxy methotrexate (7-OH MTX) in human serum were described. Preparation of 125 I-MTX and 125 I -7(OH) MTX were carried out using tyrosine methyl ester (TME) and chloramine-T (Ch-T) as oxidizing agent. HPLC column was used for purification of the prepared tracers. The production of polyclonal anti - bodies was carried out using six rabbits divided to two groups. The first one was immunized intraperitoneal through primary injection and three booster doses using MTX-BSA conjugate while the other group was immunized using 7(OH) MTX-BSA conjugate. Low density magnitizable cellulose iron oxide particles have been used to couple covalently to polyclonal antibody. The results obtained provide a low cost, simple, sensitive, specific, and accurate RIA system based on magnetizable solid phase separation.

  20. The metabolism of parathyroid hormone in kidney

    International Nuclear Information System (INIS)

    In order to investigate the mechanism and localization of parathyroid hormone (PTH), the degradation and the effects of calcium ion to PTH degradation in kidney, bovine PTH (b-PTH 1 - 84) and its synthetic N-terminal peptide (b-PTH 1 - 34) labeled with 125I by Chloramine T methods (125I-b-PTH 1 - 84 and 125I-b-PTH 1 - 34) or labeled with horse radish peroxidase (125I-POX-b-PTH 1 - 84 and 125I-POX-bPTH 1-34) were used to study the disappearance from the blood stream and degradation and retention in the kidney after intravenous injections in male Wistar rats, weighing approximately 350 - 450 g. Degradation of PTH was studied in vitro, using isolated cells and homogenates of the kidney, and the effects of calcium ion to PTH degradation were furthermore studied, using our kidney perfusion system. PTH labeled with 125I and POX was less degraded by the kidney than PTH labeled with 125I alone. PTH 1 - 34 was more delayed in blood stream than PTH 1 - 84. Isolated intact kidney cells degrade PTH less efficiently than homogenates, indicating the prominance of microsomal degradative system in the kidney. The degradation of PTH in kidney was supposed to be controlled by calcium ion in our kidney perfusion system. (author)

  1. Galanin inhibits acetylcholine release in the ventral hippocampus of the rat: histochemical, autoradiographic, in vivo, and in vitro studies

    International Nuclear Information System (INIS)

    A high density of galanin binding sites was found by using 125I-labeled galanin, iodinated by chloramine-T, followed by autoradiography in the ventral, but not in the dorsal, hippocampus of the rat. Lesions of the fimbria and of the septum caused disappearance of a major population of these binding sites, suggesting that a large proportion of them is localized on cholinergic nerve terminals of septal afferents. As a functional correlate to these putative galanin receptor sites, it was shown, both in vivo and in vitro, that galanin, in a concentration-dependent manner, inhibited the evoked release of acetylcholine in the ventral, but not in the dorsal, hippocampus. Intracerebroventricularly applied galanin fully inhibited the scopolamine stimulated release of acetylcholine in the ventral, but not in the dorsal, hippocampus, as measured by the microdialysis technique. In vitro, galanin inhibited the 25 mM K+-evoked release of [3H]acetylcholine from slices of the ventral hippocampus, with an IC50 value of ≅ 50 nM. These results are discussed with respect to the colocalization of galanin- and choline acetyltransferase-like immunoreactivity in septal somata projecting to the hippocampus

  2. Development of 123I-labelled NNC 13-8241 as a radioligand for SPECT visualization of benzodiazepine receptor binding

    International Nuclear Information System (INIS)

    [125I]- and [123I]NNC 13-8241 were prepared from the trimethyltin precursor and radioactive iodide using the chloramine-T method. The total radiochemical yields of [125I]- and [123I]NNC 13-8241 were 60-70% and 40-50% respectively, with radiochemical purity higher than 98%. In binding studies with [125I]NNC 13-8241 in rats in vitro and in vivo a high uptake of radioactivity was demonstrated in brain regions known to have a high density of benzodiazepine (BZ) receptors such as the occipital and frontal cortex. SPECT examination with [123I]NNC 13-8241 in a Cynomolgus monkey demonstrated a high uptake of radioactivity in the occipital and frontal cortex. After displacement with flumazenil radioactivity in these brain regions was reduced to the level of a central region including the pons. Four hours after injection about 80% of the radioactivity in monkey plasma represented unchanged radioligand. This low degree of metabolism indicates that NNC 13-8241 is metabolically more stable than the radioligands hitherto developed for imaging of BZ-receptors in the primate brain

  3. Emergency membrane contactor based absorption system for ammonia leaks in water treatment plants

    Institute of Scientific and Technical Information of China (English)

    SHAO Jiahui; FANG Xuliang; HE Yiliang; JIN Qiang

    2008-01-01

    Because of the suspected health risks of trihalomethanes (THMs), more and more water treatment plants have replaced traditionalchlorine disinfection process with chloramines but often without the proper absorption system installed in the case of ammonia leaksin the storage room. A pilot plant membrane absorption system was developed and installed in a water treatment plant for this purpose.Experimentally determined contact angle, surface tension, and corrosion tests indicated that the sulfuric acid was the proper choice as the absorbent for leaking ammonia using polypropylene hollow fiber membrane contactor. Effects of several operating conditionson the mass transfer coefficient, ammonia absorption, and removal efficiency were examined, including the liquid concentration,liquid velocity, and feed gas concentration. Under the operation conditions investigated, the gas absorption efficiency over 99.9%was achieved. This indicated that the designed pilot plant membrane absorption system was effective to absorb the leaking ammonia in the model storage room. The removal rate of the ammonia in the model storage room was also experimentally and theoretically foundto be primarily determined by the ammonia suction flow rate from the ammonia storage room to the membrane contactor. The ammoniaremoval rate of 99.9% was expected to be achieved within 1.3 h at the ammonia gas flow rate of 500 m3/h. The success of the pilot plantmembrane absorption system developed in this study illustrated the potential of this technology for ammonia leaks in water treatmentplant, also paved the way towards a larger scale application.

  4. Biologically active monoiodinated alpha-MSH derivatives for receptor binding studies using human melanoma cells

    International Nuclear Information System (INIS)

    Three different monoiodinated radioligands of alpha-MSH (alpha-melanocyte-stimulating hormone) were compared in a binding assay with human D10 melanoma cells: [Tyr(125I)2]-alpha-MSH, [Tyr(125I)2,NIe4]-alpha-MSH, and [Tyr(125I)2,NIe4,D-Phe7]-alpha-MSH. They were prepared either by the classical chloramine T method or by the Enzymobead method. A simple and rapid purification scheme was developed consisting of a primary separation on reversed-phase C18 silica cartridges immediately after the iodination, followed by HPLC purification before each binding experiment. Biological testing of the three radioligands showed that they all retained high melanotropic activity in the B16 melanin assay and the Anolis melanophore assay. However, in human D10 melanoma cells, [Tyr(125I)2,NIe4]-alpha-MSH led to a high degree of non-specific binding to the cells which could not be displaced by excess alpha-MSH and only partially by [NIe4]-alpha-MSH. The [Tyr(125I)2,NIe4,D-Phe7]-alpha-MSH tracer gave similar results but with a much lower proportion of non-specific binding. On the other hand, [Tyr(125I)2]-alpha-MSH proved to be an excellent radioligand whose non-specific binding to the D10 cells was not higher than 20% of the total binding

  5. Free Radical Chemistry of Disinfection Byproducts. 3. Degradation Mechanisms of Chloronitromethane, Bromonitromethane and Dichloronitromethane

    Energy Technology Data Exchange (ETDEWEB)

    Bruce J. Mincher; Stephen P. Mezyk; William J. Cooper; S. Kirkham Cole; Robert V. Fox; Piero R. Gardinali

    2010-01-01

    Halonitromethanes (HNMs) are byproducts formed through ozonation and chlorine/ chloramine disinfection processes in drinking waters that contain dissolved organic matter and bromide ions. These species occur at low concentration, but have been determined to have high cytotoxicity and mutagenicity and therefore may represent a human health hazard. In this study, we have investigated the chemistry involved in the mineralization of HNMs to non-hazardous inorganic products through the application of advanced oxidation and reduction processes. We have combined measured absolute reaction rate constants for the reactions of chloronitromethane, bromonitromethane and dichloronitromethane with the hydroxyl radical and the hydrated electron with a kinetic computer model in an attempt to elucidate the reaction pathways of these HNMs. The results are compared to measurements of stable products resulting from steady-state 60Co y-irradiations of the same compounds. The model predicted the decomposition of the parent compounds and ingrowth of chloride and bromide ions with excellent accuracy, but the prediction of the total nitrate ion concentration was slightly in error, reflecting the complexity of nitrogen oxide species reactions in irradiated solution.

  6. Influence of water quality on nitrifier regrowth in two full-scale drinking water distribution systems.

    Science.gov (United States)

    Scott, Daniel B; Van Dyke, Michele I; Anderson, William B; Huck, Peter M

    2015-12-01

    The potential for regrowth of nitrifying microorganisms was monitored in 2 full-scale chloraminated drinking water distribution systems in Ontario, Canada, over a 9-month period. Quantitative PCR was used to measure amoA genes from ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA), and these values were compared with water quality parameters that can influence nitrifier survival and growth, including total chlorine, ammonia, temperature, pH, and organic carbon. Although there were no severe nitrification episodes, AOB and AOA were frequently detected at low concentrations in samples collected from both distribution systems. A culture-based presence-absence test confirmed the presence of viable nitrifiers. AOB were usually present in similar or greater numbers than AOA in both systems. As well, AOB showed higher regrowth potential compared with AOA in both systems. Statistically significant correlations were measured between several water quality parameters of relevance to nitrification. Total chlorine was negatively correlated with both nitrifiers and heterotrophic plate count (HPC) bacteria, and ammonia levels were positively correlated with nitrifiers. Of particular importance was the strong correlation between HPC and AOB, which reinforced the usefulness of HPC as an operational parameter to measure general microbiological conditions in distribution systems. PMID:26518069

  7. Iodine-123 labeled derivatives of methylphenidate: potential SPECT radiopharmaceuticals for brain dopamine transporters

    Energy Technology Data Exchange (ETDEWEB)

    Pan, D.; Gatley, S.J.; Chen, R.; Ding, Y.-S. [Brookhaven National Lab., Upton, NY (United States)

    1996-06-01

    Since dl-threo-[{sup 11}C]methylphenidate (Ritalin) and especially the more active enantiomer, d-threo-[{sup 11}C]methylphenidate, have favorable properties for PET studies, we prepared two radioiodinated analogs of methylphenidate, p-[{sup 123}I]iodomethylphenidate and m-[{sup 123}I]iodo-p-hydroxymethylphenidate with a view to evaluating them as potential SPECT tracers. To prepare p-[{sup 123}I]iodomethylphenidate, the p-tributyltin derivative was prepared from the previously reported p-bromomethylphenidate and reacted under acidic conditions with I-123 iodide plus chloramine-T at room temperature for 90 seconds. The predomimant radioactive product was obtained in 85% radiochemical yield and > 10 Ci/{mu}mol specific radioactivity after HPLC purification. It had the same HPLC retention time as a spectroscopically characterized non-radioactive p-iodomethylphenidate standard prepared via nitration of methylphenidate and diazotization, after protection of the secondary amino group by benzoylation. A second radioiodinated methylphenidate derivative, m-[{sup 123}I]iodop-hydroxymethylphenidate was prepared in 80% radiochemical yield by direct iodination of the known p-hydroxymethylphenidate. In this case the non-radioactive standard was prepared by iodination of p-hydroxyritalinic acid using I{sub 2} and iodic acid, followed by esterification. (author).

  8. Factors Affecting Bacterial Growth in Drinking Water Distribution System

    Institute of Scientific and Technical Information of China (English)

    WEI LU; XIAO-JIAN ZHANG

    2005-01-01

    Objective To define the influence of some parameters, including assimilable organic carbon (AOC), chloramine residual, etc. on the bacterial growth in drinking water distribution systems. Methods Three typical water treatment plants in a northern city (City T) of China and their corresponding distribution systems were investigated. Some parameters of the water samples, such as heterotrophic plate content (HPC), AOC, CODMn, TOC, and phosphate were measured. Results The AOC in most water samples were more than 100 μg/L, or even more than 200 μg/L in some cases. The HPC in distribution systems increased significantly with the decrease of residual chlorine. When the residual chlorine was less than 0.1 mg/L, the magnitude order of HPC was 104 CFU/mL; when it was 0.5-0.7 mg/L, the HPC was about 500 CFU/mL. Conclusion For controlling the biostability of drinking water, the controlling of AOC and residual chlorine should be considered simultaneously. The influence of phosphors on the AOC tests of water is not significant. Phosphors may not be the limiting nutrient in the water distribution systems.

  9. Radioimmunoimaging of ovarian cancer with 131I labelled CEA monoclonal antibody

    International Nuclear Information System (INIS)

    Objective: To investigate radioimmunoimaging with 131I labelled CEA McAb and its value in diagnosis and treatment of ovarian cancer. Methods: CEA McAb was labelled with 131I by standard chloramine T procedure. The radiolabeled McAb was given intravenously to the patients. The scintigraphy was performed at different time. Results: In 105 patients with histopathology proved ovarian cancers, for 96 patients the lesions were well located with RII (true positives), for the remaining 9 patients, the results were false negative. 22/23 cases with RII diagnosed benign ovarian tumors were proved to be true negative by surgical pathology in RII. Of 96 ovarian cancers 87 were stratified into identical stages by surgical pathology all RII. 141/151 metastatic tumors were found in RII and the positive rate was as high as 93.4%. The smallest tumor defected by RII was of 1 cm in diameter. Conclusions: RII is as good as ultrasonography and CT in distinguishing benignancy and malignancy. The location, size and number of the lesions can also be determined with RII. RII of ovarian cancer with 131I-CEA McAb is valuable and helpful in early detection of ovarian cancer. It is also helpful for clinical staging, treatment programing and prognosticating

  10. Preparation, purification and primary bioevaluation of radioiodinated ofloxacin. An imaging agent

    International Nuclear Information System (INIS)

    The broad-spectrum antibiotic agents have been demonstrated as promising diagnostic tools for early detection of infectious lesions. We set out ofloxacin (Oflo), a second-generation fluoroquinolone, for the radioiodination process. In particular, this was carried out with 125I via an electrophilic substitution reaction. The radiochemical yield was influenced by different factors; drug concentration, different oxidizing agents, e.g. chloramine-T, iodogen and n-bromosuccinimide, pH of medium, reaction time, temperature and different organic media. These parameters were studied to optimize the best conditions for labeling with ofloxacin. We found that radiolabeling in ethanol medium showed a 70% radiochemical yield of 125I-ofloxacin. The radioiodination was determined by means of TLC and HPLC. The cold labeled Oflo (127I-Oflo) was prepared and controlled by HPLC. The cold labeled Oflo was also confirmed by NMR and MS techniques. Furthermore, biodistribution studies for labeled 125I-Oflo were examined in two independent groups (3 mice in each one); control and E. Coli-injected (inflamed). The radiotracer showed a good localization in muscle of thigh for inflamed group as compared to control. In conclusion, ofloxacine might be a promising target as an anti-inflammatory imaging agent.

  11. Kinetic and Mechanistic Studies of Oxidation of an Antiallergic Drug with Bromamine-T in Acid and Alkaline Media

    International Nuclear Information System (INIS)

    Cetrizine dihydrochloride (CTZH) is widely used as an anti-allergic drug. Sodium N-bromo-p-toluenesulfonamide or bromamine-T (BAT) is the bromine analogue of chloramine-T (CAT) and is found to be a better oxidizing agent than CAT. In the present research, the kinetics of oxidation of CTZH with BAT in acid and alkaline media was studied at 313 K. The experimental rate laws obtained are: -d[BAT]/dt = k[BAT] [CTZH]0.80[H+]-0.48 in acid medium and -d[BAT]/dt = k[BAT][CTZH]0.48[OH-]0.52[PTS]-0.40 in alkaline medium where PTS is p-toluenesulfonamide. Activation parameters and reaction constants were evaluated. The solvent isotope effect was studied using D2O. The dielectric effect is positive. The stoichiometry of the reaction was found to be 1:1 and the oxidation products were identified as 4-chlorobenzophenone and (2-piperazin-1-yl-ethoxy)-acetic acid in both media. The rate of oxidation of CTZH is faster in acid medium. Suitable mechanisms and related rate laws have been worked out

  12. A general method for the production of 125I-labelled low-molecular-weight tracers for radioimmunoassay

    International Nuclear Information System (INIS)

    A general method is described for the separation of low-molecular-weight 125I-labelled tracers from a chloramine-T labelling mixture, containing the starting material, the tracer, labelled by-products, free radioiodine and reagents used in the labelling procedure. Small molecules like tyrosine, thyronine and steroids as well as their tyrosine methyl ester conjugates are adsorbed on Sephadex LH-20 dextran gel. The introduction of iodine atoms increases the elution volume and the distribution coefficient in proportion to the number of iodine atoms per molecule. Organic solvents like ethanol are also adsorbed on dextran gel, which results in desorption of the starting material or its iodine-substituted derivatives. The elution order follows the number of iodine substituents per molecule, i.e. unsubstituted starting material, mono-, di-, tri- and tetra-substituted molecules. Using a water/ethanol binary eluent in which water can be considered as inert diluent, the elution is governed by the ethanol concentration. The finding that the logarithm of the distribution coefficient of the solutes is linearly correlated with the logarithm of the ethanol concentration permits an optimization of the separation. (author)

  13. Studies into the radiobromination and -iodination of aromatic compounds with n-halogen compounds without addition of carriers

    International Nuclear Information System (INIS)

    There is a special need for radiohalogenated compounds for diagnostic nuclear medicine, in particular for no-carrier-added (nca) short lived cyclotron products. In this study the applicability of chloramine-T (CAT) and dichloramine-T (DCT) has been demonstrated for nca-radiohalogenation with bromine-75, 77 and iodine-123 in aqueous and organic solvents. Radio gaschromatography and -HPLC are used for product analysis. In aqueous solution the optimum reaction conditions with respect to pH, concentration of CAT, reaction time and added bromide-carrier are determined using tyrosine as a model substrate. The suitability of the CAT method for radiobrominations under convenient and mild conditions is demonstrated for some biomolecules such as amino acids and nucleobases as well as for peptides and the proteins urokinase and HSA. Dichloramine-T is found to be a new efficient reagent for radiobromination and -iodination of aromatic compounds in various organic solvents such as acetic acid, dichloromethane or carbontetrachloride. A high para-selectivity is observed and the radiochemical yields (80%) are as high as in aqueous solution. A comparison of this reagent with different in-situ halogenation agents show that DCT is superior with respect to reaction time, concentration of the reagent and thus oxidative side reactions, and ease of handling. (orig./RB)

  14. Solid phase group specific absorbants in assays for glycoproteins

    International Nuclear Information System (INIS)

    The focus of this paper is on several technical advances in the assays for glycoprotein hormones and enzymes that have been achieved by use of the solid phase carbohydrate specific adsorbant concanavalin-A. Puriffication of glycoprotein radioligand after labelling by the chloramine-T method is readily accomplished using a small column of agarose bound concanavalin-A which separates glycoprotein radioligand from radioiodide and radiolabelled unadsorbed contaminants. After concanavalin-A column chromatography, radiolabelled glycoprotein hormone preparations exhibited improved binding to antibodies and tissue receptors. To increase the effective sensitivity of radioimmunoassays for glycoproteins, agarose bound concanavalin-A is used to extract and concentrate the glycoproteins from various biologic samples. For example, the effective sensitivity for the detection of human thyrotropin in serum was improved approximately 5 fold by using concanavalin-A concentrates of 1.5 ml of serum. Partial purification of the glycoprotein dopamine-β-hydroxylase from serum using agarose bound concanavalin-A resulted in separation of the serum factors that interfere with the measurement of enzyme activity. We conclude that in assays for glycoproteins, concanavalin-A is useful for purification of radioligand, for preparation of concentrates of glycoproteins from biologic samples, and for separation of glycoproteins from various interfering factors contained in biologic samples prior to radioligand or radioenzyme assay. (orig.)

  15. Solid-phase group-specific adsorbants in assays for glycoproteins

    International Nuclear Information System (INIS)

    The focus of the paper is on several technical advances in the assays for glycoprotein hormones and enzymes that have been achieved by the use of the solid-phase cabohydrate-specific adsorbant concanavalin-A. Purification of glycoprotein radioligand after labelling by the Chloramine-T method is readily accomplished using a small column of agarose-bound concanavalin-A which separates glycoprotein radioligand from radioiodide and radiolabelled unadsorbed contaminants. After concanavalin-A column chromatography, radiolabelled glycoprotein hormone preparations exhibited improved binding to antibodies and tissue receptors. To increase the effective sensitivity of radioimmunoassays for glycoproteins, agarose-bound concanavalin-A is used to extract and concentrate the glycoproteins from various biological samples. For example, the effective sensitivity for the detection of human thyrotropin in serum was improved approximately 5-fold by using concanavalin-A concentrates of 1.5ml of serum. Partial purification of the glycoprotein dopamine-β-hydroxylase from serum using agarose-bound concanavalin-A resulted in separation of the serum factors that interfere with the measurement of enzyme activity. We conclude that in assays for glycoproteins, concanavalin-A is useful for purification of radioligand, for preparation of concentrates of glycoproteins from biological samples and for separation of glycoproteins from various interfering factors contained in biological samples before radioligand or radioenzyme assay. (author)

  16. 125I Labelling of Protein Using Immobilized Enzyme

    International Nuclear Information System (INIS)

    For an effective solid-phase labelling of protein with 125I, studies on the immobilization of lactoperoxidase (LPO) on the inner wall of polystyrene tubes were carried out. Labelling of bovine serum albumin (BSA) and insulin was also practiced using the LPO immobilized tubes. The immobilized enzyme of about 2.5 μ g/tube was sufficient for small scale labelling since the results of radio-paper chromatography of the labelling mixture of insulin indicated that the yields were sufficiently high (80%) even in the reactions conducted at room temperature for 60 sec. The results of the Sephadex column chromatography indicated that the labelled products were not contaminated with LPO-125I, and the radiochemical purity of the products was more than 90%. In considering the general trend that the 125I labelled protein obtained by using LPO maintains its intactness better than those obtained by using chloramine-T, together with the tendency of yield enhancing with increase of reactants-concentration, the LPO immobilized tube method is estimated to be one of the simple methods of labelling. The product might be applicable without further purification.

  17. Experimental research for tumor VIP receptor imaging

    International Nuclear Information System (INIS)

    To study the possibility of radioactive labelled vasoactive intestinal peptide (VIP) for tumor VIP receptor imaging. 125I-VIP was prepared by chloramine-T method, and purified by Sephadex G-50 column chromatography. The bioactivity and stability of 125I-VIP were measured by silica 60 F254 TLC and competition test to SGC7901 cell in vitro. The biodistribution of 125I-VIP was studied in the nude mice bearing tumor. The results showed that labelled rate of 125I was 73.8%, the specific activity was 18.2 PBq/mol, the radiochemical purity (RCP) was over 98% and remained 96.3% after 48 days stored at -80 degree C. The specific binding of 125I-VIP to the SGC7901 cell was inhibited by VIP in dose dependence in the competition experiment. The radioactivity of tumor was higher than that of muscles in all phases (P<0.05-0.01), the peak activity of tumor occurred at 30 min (3.58 +- 0.48ID%/g) and the peak ratio of T/N occurred at 60 min after the injection. The activity of lungs was obviously higher than that of blood, the intestine was always in low level. Most of the activity in the body was mainly eliminated from kidney. The present study demonstrated that the radioactive labelled VIP is a promising agent for tumor VIP receptor scintigraphy

  18. Radioactive Iodo-azathioprine as a possible model for cancer imaging and therapy

    International Nuclear Information System (INIS)

    Azathioprine (Aza) is antimetabolite drug, could be labeled with the auger emitters iodine-125. Aza could be used an ideal vehicle to deliver radioactive decay energy to DNA of tumor cells causing DNA double strand break, thus stop DNA synthesis. In this study, the process of labeling was done via direct labeling technique using chloramine-T as an oxidizing agent and heating to 75 degree C, for 30 minutes at ph using 0.5 M phosphate buffer. The radiochemical purity of the labeled compound, at the above conditions, was determined using electrophoresis technique and was above 90%. About 2.5x106 of enrich ascites carcinoma (EAC) was injected intraperitoneally(i.p) to produce ascites and intramuscularly (i.m) in the right thigh to produce solid tumor in female mice. Biodistribution studies were carried out by injecting solution of 125I-aza in normal and tumor bearing mice. The uptake in ascites was over 40 % of the injected dose at 12 h post injection and above 20 % in solid tumor . These data revealed localization of the tracer in the tumor tissues with high percentage sufficient to give radiotherapeutic effect as well as promising tool for diagnosis.

  19. Powerful colloidal silver nanoparticles for the prevention of gastrointestinal bacterial infections

    International Nuclear Information System (INIS)

    In this work we have demonstrated a powerful disinfectant ability of colloidal silver nanoparticles (NPs) for the prevention of gastrointestinal bacterial infections. The silver NPs colloid was synthesized by a UV-enhanced chemical precipitation. Two gastrointestinal bacterial strains of Escherichia coli (ATCC 43888-O157:k-:H7) and Vibrio cholerae (O1) were used to verify the antibacterial activity of the as-prepared silver NPs colloid by means of surface disinfection assay in agar plates and turbidity assay in liquid media. Transmission electron microscopy was also employed to analyze the ultrastructural changes of bacterial cells caused by silver NPs. Noticeably, our silver NPs colloid displayed a highly effective bactericidal effect against two tested gastrointestinal bacterial strains at a silver concentration as low as ∼3 mg l−1. More importantly, the silver NPs colloid showed an enhancement of antibacterial activity and long-lasting disinfectant effect as compared to conventional chloramin B (5%) disinfection agent. These advantages of the as-prepared colloidal silver NPs make them very promising for environmental treatments contaminated with gastrointestinal bacteria and other infectious pathogens. Moreover, the powerful disinfectant activity of silver-containing materials can also help in controlling and preventing further outbreak of diseases. (paper)

  20. Preparation of 125I labelled nerve growth factor and study of its pharmacokinetics

    International Nuclear Information System (INIS)

    125I-Nerve growth factor (125I-NGF) with more than 95% of radiochemical purity is prepared by chloramine-T method. After I.V. and I.M. injection of 125I-NGF, pharmacokinetics of NGF in mice is determined by SDS-PAGE method. The results show that concentration-time curves after I.V. injection are fitted to a 2-compartment model are those after I.M. injection are fitted to a 1-compartment model. After I.V. injection of 25 μg/kg, the elimination half life (t1/2(β)) is 3.65 h. After I.M. injection of 75, 25, 10, 3.3 μg/kg, t1/2(β) is 1.79, 2.25, 2.30, 3.24 h, respectively. The mean plasma clearance (CLs) is 0.37 L/(h·kg), the appearance volume of distribution (Vd) is 1.18 L/kg and the mean residence time (tr-bar) in mice is 2.78 h. The pharmacokinetics of 125I-NGF in mice is useful for clinical trial

  1. Development of a radioimmunoassay for the measurement of human leptin in serum

    International Nuclear Information System (INIS)

    Leptin is a 16 kDa polypeptide hormone encoded by the obese gene (ob) and secreted by adipose tissue. This hormone plays a major role in energy homeostasis and regulation of food intake and body weight. It also affects the metabolic, neuroendocrine and reproductive systems. Labelling of recombinant human leptin with 125I was best performed by the Chloramine-T method. New Zealand white rabbits were immunised with recombinant human leptin, cross-reaction of obtained antisera was analyzed with 10 different antigens. The separation of bound and free fractions was performed using the second antibody - PEG method. The obtained tracer had specific activities of 2.8-3.3 kBq/μg and had a stability of 5 weeks. A highly specific polyclonal antibody was obtained without measurable cross-reaction against the analysed antigens. Concentrations of human leptin were measured by a single overnight incubation assay with a sensitivity of 0.5 ng/ml and a measuring range of 0.5-100 ng/ml. The intra-assay and inter-assay coefficient of variation was under 6% and 8%, respectively. Recovery ranged from 88% to 106%. Serum human leptin concentrations can be accurately and precisely measured by this new radioimmunoassay. Preliminary results obtained from the measurement of serum leptin in lean, overweight and obese patients are presented. Serum leptin concentrations correlated with body mass index and were significantly higher in women than in men, except for obese patients. (author)

  2. Development of radioimmunoassay for human leptin and its primary clinical application

    International Nuclear Information System (INIS)

    Leptin was a hormone synthesized and secreted by lipid cells which encoded and expressed by the obese gene. In this article, rabbit-anti-human leptin polyclonal antibodies (PcAb) was prepared by immunizing rabbits with recombined human leptin while 125I-leptin was obtained by chloramines-T method. A method of RIA for human leptin was developed, using these self-made preparations. The result of tests showed high sensitivity and specificity with reliable reproducibility, which proved that the quality of our preparations was no less good than that of the imported Linco product. The normal range (BMI 18-25) was 2.15 ± 1.46 ng/mL (male, 34 cases) and 7.86 ± 3.60 ng/mL(female, 36 cases). There was significant positive correlation (r=0.72, P<0.001) between serum leptin concentrations and body-mass-index (BMI), in the case of 112 healthy persons were separated to male group and female group. Tere was no significant correlation between serum leptin concentrations and ages. So did follicle-stimulating hormone, luteinizing hormone, prolactin, progesterone and estradiol in females. But in males, serum leptin concentrations correlated directly and negatively with testosterone concentrations. (authors)

  3. Antiseptics and microcosm biofilm formation on titanium surfaces

    Directory of Open Access Journals (Sweden)

    Georgia VERARDI

    2016-01-01

    Full Text Available Abstract Oral rehabilitation with osseointegrated implants is a way to restore esthetics and masticatory function in edentulous patients, but bacterial colonization around the implants may lead to mucositis or peri-implantitis and consequent implant loss. Peri-implantitis is the main complication of oral rehabilitation with dental implants and, therefore, it is necessary to take into account the potential effects of antiseptics such as chlorhexidine (CHX, chloramine T (CHT, triclosan (TRI, and essential oils (EO on bacterial adhesion and on biofilm formation. To assess the action of these substances, we used the microcosm technique, in which the oral environment and periodontal conditions are simulated in vitro on titanium discs with different surface treatments (smooth surface - SS, acid-etched smooth surface - AESS, sand-blasted surface - SBS, and sand-blasted and acid-etched surface - SBAES. Roughness measurements yielded the following results: SS: 0.47 µm, AESS: 0.43 µm, SB: 0.79 µm, and SBAES: 0.72 µm. There was statistical difference only between SBS and AESS. There was no statistical difference among antiseptic treatments. However, EO and CHT showed lower bacterial counts compared with the saline solution treatment (control group. Thus, the current gold standard (CHX did not outperform CHT and EO, which were efficient in reducing the biofilm biomass compared with saline solution.

  4. The use of protein A in solid-phase binding assays: a comparison of four radioiodination techniques

    International Nuclear Information System (INIS)

    Preparations of protein A radioiodinated by 4 different methods have been compared in indirect radioimmunoassays. The oxidative methods (chloramine-T and iodogen) for direct iodination of tyrosyl and histidyl residues were applied with high efficiency and gave a suitable product, provided the substitution ratio was kept low (1 iodine atom/molecule of protein A). Higher levels of modification tended to perturb the Fsub(c)-binding characteristics of the protein, especially with the use of iodogen. Introduction of the isotope via substitution of lysyl residues (Bolton-Hunter and Wood reagents) was also examined. The Bolton-Hunter modification of protein A gave an unsuitably low labelling efficiency: in contrast, the Wood reagent gave efficiencies approaching 50%. Protein A could be extensively substituted with the latter reagent (>5 diiodinated benzimidate molecules per protein molecule). Thus, the use of the Wood-labeled protein A could raise the sensitivity of the binding assay at least an order of magnitude compared to using protein A iodinated by the oxidative methods. The effects on the biological activity of protein A exerted by the different labeling procedures are rationalized on the basis of the amino acid composition and tertiary structure of the protein. (Auth.)

  5. Studies on porcine pancreatic elastase activity, 1

    International Nuclear Information System (INIS)

    An improved method of radioimmunoassay was devised to offer a successful formula for determining blood concentration of elastase. With porcine pancreatic elastase as the antigen, rabbits were immunized to obtain antiserum. Iodinated elastase labeled by the chloramine-T procedure using 131I (or 125I) had a specific activity of 200 - 300 mCi/mg. The double antibody method was used for BF separation. While the usual method of radioimmunoassay was not always successful in obtaining accurate serum concentration of elastase, the use of diisopropyl fluorophosphate (DFP) was able to eliminate the disturbing influence of intra-serous inhibitors, α1-AT and α2-M, eventually producing satisfactory results. With the use of DFP, the elastase standard curve and the porcine serum dilution curve had a statistically significant correlation; precision and recovery were both satisfactory; cross-reactivity of the antiserum with trypsin and chymotrypsin was less than 0.001%. The minimal detectable concentration of elastase was 5 ng/ml, and the range of normal fasting porcine serum level was 70 - 100 ng/ml. (author)

  6. [Update of DIN 19.643--treatment and disinfection of swimming pool and bathing tub water].

    Science.gov (United States)

    Hässelbarth, U

    1992-08-01

    German Standards Specification DIN 19,643 is at present under revision for health reasons and because of both negative and positive experiences gathered in practice. To enable adaptation of the standards specification to future developments, a Part I of the specification is being created comprising the demands to be made on the quality of the water and general demands on the construction and operation of swimming pools and tubs and basins in bath houses, e.g. in spas or municipal swimming pools. The subsequent parts of the new specification (Part 2 to Part n) concern the demands to be made on individual combinations of processes; these can be supplemented at any time in accordance with technical progress without requiring revision of the entire standards specification. Essential innovations are the reformulation of the required efficiency of disinfection, the introduction of the parameters Legionella pneumophila, trihalogen methane (THM) and the reduction of the limit value for chloramines. Technically speaking, the new features concern the automatic measurement of the auxiliary parameters of hygiene such as redox potential, pH value and free chlorine, automatic control of disinfectant additions, automatic filter rinsing with fluidization of the filter-bed to a prescribed minimum bed expansion, and the sight-glas at the filter container. The demands made on Jacuzzi and warm water spouted bed besins are integrated into the specification, thus obviating the need for German Standards Specification DIN 19,644. PMID:1392275

  7. Production of antibodies against secretin and their use for radioimmunoassay of secretin

    International Nuclear Information System (INIS)

    Synthetic thyroglobulin was bonded to bovine albunia and thyroglobulin according to the principle of the carbodiimide condensation reaction. 16 rabbits were immunized with these conjugates and with unconjugated secretin. Secretin labelling with 125I was carried out by the chloramin-T method. The tracer has a specific activity of 15.45 mCi/mg. A secretin RIA was developed using the double antibody method. The sensitivity of the system could be raised by variation of the specific activity of the tracer and optimisation of the incubation parameters. Antisera were compared. The titers of secretin/bovine albumine conjugate antisera were similar to the antisera against secretin thyroglobulin conjugate. The sensitivity of the standard curves was higher for secretin/bovine albumin conjugate antisera than for thyroglobulin conjugate antisera. Two antisera were tested for specificity. The detection threshold of antiserum S 5 IX was 12,43 pmol/l while the 50% intercept was at 55.45 pmol/l. This antiserum is particularly suitable for a secretin RIA. (orig./MS)

  8. Therapeutic effect of 131I-histamine-indomethacin in mice with Lewis pulmonary tumor

    International Nuclear Information System (INIS)

    Histamine-indomethacin (HIS-IN) was labeled with 131I by chloramine-T method. Thin-layer chromatography (TLC) was performed to evaluate the labeling ratio, radiochemical purity and stability of 131I-HIS-IN, using silicagel GF254 coated on glass plates, with chloroform and methanol being the mobile phase. The biodistributions of 131I-HIS-IN in Lewis pulmonary tumor model mice and normal mice were examined, and therapeutic effect of 131I-HIS-IN on mice with Lewis pulmonary tumor was studied. The results showed that radiochemical purity of the 131I-HIS-IN was 98%, and the highest %ID·g-1 of tumor tissue was 4.73±0.07 at 4 h, while the tumor/blood ratios were 2.95±0.30 at 8 h, 2.67±0.62 at 12 h and 3.54±0.54 at 16 h. The ratios, and the necrotic tissue cells, increased with the post-injection hours. Therefore, 131I-HIS-IN can be a new radioactive drug for tumor therapy. (authors)

  9. Luminal oxidants selectively modulate electrogenic ion transport in rat colon

    Institute of Scientific and Technical Information of China (English)

    Julio M Mayol; Yolanda Adame-Navarrete; Pilar Alarma-Estrany; Elena Molina-Roldan; Fernando Huete-Toral; Jesus A Fernandez-Represa

    2006-01-01

    AIM: To investigate the effects of luminal exposure to H2O2 and two related thiol oxidizing agents on basal and stimulated chloride secretion in native colon using electrophysiological and pharmacological approaches.METHODS: Unstripped rat distal colon segments were mounted in Ussing chambers. Potential difference, cal culated resistance and short-circuit current across unstripped colon segments were monitored with a dual voltage/current clamp. Paracellular permeability was assessed by measuring the mucosa-to-serosa flux of a fluorescent probe (FITC).RESULTS: Luminal exposure to hydrogen peroxide transitorily stimulated chloride secretion without altering barrier function. This stimulatory effect could be blocked by basolateral atropine but not indomethacin. The cysteine and methionine oxidizing compounds, phenylarsine oxide and chloramine T respectively, mimicked the effect of H2O2, except for a drop in transcolonic resistance after 30 min. In contrast to the observed stimulatory effect on basal secretion, cAMP-stimulated electrogenic ion trans port was blunted by luminal H2O2. However, the Ca2+-activated response remained unchanged.CONCLUSION: H2O2 may be an important selective modulator of intestinal ion and water secretion in certain pathologic conditions such as inflammation or ischemiareperfusion by multiple mechanisms.

  10. Labeling of polyamidoamine with 125I and its biodistribution in mice

    International Nuclear Information System (INIS)

    Objective: To investigate the biodistribution of 125I labeled dendrimer nanomaterial--polyamidoamine (PAMAM) in mice. Methods: Tyrosine was conjugated to four generation PAMAM by N-Hydroxysuccinimide,then 125I was labeled on PAMAM with chloramines-T method,and purified by dialysis. Labeling rate,radiochemical purity and stability of 125I-PAMAM were detected by radioactive thin layer chromatography scanning. The gamma imaging and biodistribution were detected by in vivo imaging system and gamma counter at one, four, eight, twenty-four and forty-eight hours after intravenous injection. Results: The 1H nuclear magnetic resonance results showed that about two tyrosines were conjugated to PAMAM. The 125I labeling rate was about 56% and radiochemical purity was more than 98%. The radiochemical purity of labeled compound remained more than 90% at 72 hours in vitro. In vivo imaging results showed that PAMAM was mainly accumulated in liver periphery. The gamma counter results showed that PAMAM mainly accumulated in liver, kidney and spleen, the excretion of PAMAM was slow and there has high dose of PAMAM in mice at 48 hours. Conclusion: PAMAM with no chemical modification was mainly accumulated in liver, kidney and spleen, and the excretion of PAMAM was slow, so PAMAM is not fit as drug carrier. PAMAM need to chemical modification to accelerate excretion and prevent the emergence of toxicity caused by accumulation in body. (authors)

  11. In vivo detection of prostatic carcinoma with antibodies against prostatic acid phosphatase

    International Nuclear Information System (INIS)

    Serum prostatic acid phosphates (PAP) immunoassay is used to evaluate patients with prostatic carcinoma; however, as with other tumor markers, the enzyme levels do not necessarily reflect the presence or extent of tumor. The authors investigated the use of radiolabeled PAP antibodies for the in vivo detection of prostatic carcinoma by external scintillation imaging. Nine patients with prostatic carcinoma were entered into the study. Each received from 2.0 to 2.5 mCi of I-131 labeled antibody to PAP, administered i.v. The immunogen (PAP) was purified from normal human seminal fluid. Antiserum was prepared in rabbits by injecting the purified PAP. The antibodies were labeled with I-131 by chloramine-T method (10 to 20 Ci/g of IgG). Total body images were obtained at 24 and 48 hrs following administration of the labeled antibody. Nontarget I-131 activity was diminished by computer processing. Tumor sites detected by I-131 antibodies were correlated with other diagnostic procedures. In 7 of 9 patients primary and metastatic sites of cancer were detected by antibody imaging, however, no bone lesions were detected (6 cases). In 3 patients with concomitant pulmonary tumors, one was identified as of prostate origin. The serum PAP was normal in 4 patients; however, the primary tumor was identified in 3 of these. These findings suggest that the localization of prostatic carcinoma by means of in-vivo imaging of labeled antibodies to PAP is feasible and offers diagnostic opportunities based upon the functional characteristics

  12. A pigeon crop sac radioreceptor assay for prolactin

    International Nuclear Information System (INIS)

    Ovine prolactin, labelled with 125I by either lactoperoxidase or a mild chloramine T method, was bound to receptors from the pigeon crop sac mucosa cells of prolactin-injected pigeons. Binding was demonstrated in a crude homogenate of mucosal cells removed from the crop by scraping and in a subcellular fraction in which 5'- nucleotidase activity was enhanced two- to three-fold. The binding was specific, dependent on time, temperature and the concentration of receptors and had a dissociation constant of 7 x 10-10 mol/l. The binding capacity of the crop tissue was 71 fmol/mg membrane protein. Nine purified preparations of prolactin from four species were assayed by local pigeon crop sac bioassay and by radioreceptor assay. The two methods were highly correlated (r = 0.934). The regression equation was radioreceptor assay = 1.22 bioassay - 0.18 indicating a 1:1 correspondence between the two methods for prolactin purified from sheep, rat, horse and pig anterior pituitary glands. (author)

  13. Radioimmunoassay measurement of secretin half-life in man

    International Nuclear Information System (INIS)

    High titer antibodies to secretin were produced in rabbits by immunization with purified porcine secretin (from GIH) conjugated to bovine serum albumin in complete Freund's adjuvant. Synthetic porcine secretin (from Squibb) was radiolabeled with 125I using chloramine-T and radiosecretin was purified using talc-silica and fibrocellulose powder. Specificity of antibodies to secretin was extensively evaluated in studies examining (1) cross-reactivity with other naturally occurring hormones, (2) parallelism of serum dilutions and secretin standards, (3) quantitative recovery of secretin added to serum samples, and (4) changes in circulating immunoreactive secretin in response to intraduodenal acidification. The mean fasting serum secretin concentration in 10 dogs was 65 +- 5 (SEM) pg per ml and in 21 healthy human volunteers it was 69 +- 5 pg per ml. In response to intraduodenal instillation of 10 mEq of HCl, portal venous secretin concentrations increased from a mean fasting value of 52 to 450 pg per ml within 2 min; peripheral venous secretin increased from 66 to 229 pg per ml within 5 min. No significant changes in peripheral serum immunoreactive secretin concentrations were identified in dogs after a protein meal. Intravenously administered secretin in man disappeared from the circulation with mean half-life 4.06 +- 0.82 (SEM) min

  14. Immunolocalization of neuroblastoma using radiolabeled monoclonal antibody UJ13A

    International Nuclear Information System (INIS)

    The monoclonal antibody UJ13A, raised after immunization of mice with human fetal brain, recognized an antigen expressed on human neuroblastoma cell lines and fresh tumors. Antibody was purified and radiolabeled with iodine isotopes using chloramine-T. In preclinical studies, 125I-labeled UJ13A was injected intravenously into nude mice bearing xenografts of human neuroblastoma. Radiolabeled UJ13A uptake by the tumors was four to 23 times greater than that by blood. In control animals, injected with a similar quantity of a monoclonal antibody known not to bind to neuroblastoma cells in vitro (FD44), there was no selective tumor uptake. Nine patients with histologically confirmed neuroblastoma each received 100 to 300 micrograms UJ13A radiolabeled with 1 to 2.8 mCi 123I or 131I. Sixteen positive sites were visible on gamma scans 1 to 7 days after injection: 15 were primary or secondary tumor sites, and one was a false positive; there were two false negatives. In two of the 15 positive sites, tumor had not been demonstrated by other imaging techniques; these were later confirmed as areas of malignant infiltration. No toxicity was encountered

  15. Dynamic behavior of histone H1 microinjected into HeLa cells

    International Nuclear Information System (INIS)

    Histone H1 was purified from bovine thymus and radiolabeled with tritium by reductive methylation or with 125I using chloramine-T. Red blood cell-mediated microinjection was then used to introduce the labeled H1 molecules into HeLa cells synchronized in S phase. The injected H1 molecules rapidly entered HeLa nuclei, and a number of tests indicate that their association with chromatin was equivalent to that of endogenous histone H1. The injected molecules copurified with HeLa cell nucleosomes, exhibited a half-life of ∼100h, and were hyperphosphorylated at mitosis. When injected HeLa cells were fused with mouse 3T3 fibroblasts < 10% of the labeled H1 molecules migrated to mouse nuclei during the next 48 h. Despite their slow rate of migration between nuclei, the injected H1 molecules were evenly distributed on mouse and human genomes soon after mitosis of HeLa-3T3 heterokaryons. These results suggest that although most histone H1 molecules are stably associated with interphase chromatin, they undergo extensive redistribution after mitosis

  16. Effects of combined 131I- and CT-BAC5 immunotherapy on NPC CNE-2 multicellular spheroids

    International Nuclear Information System (INIS)

    Objective: To develop a new specific therapeutic method for treating nasopharyngeal carcinoma (NPC) and to evaluate its effects on an in vitro tumor spheroid model. Methods: The human NPC cell line CNE-2 spheroids were grown in culture medium, on a thin layer of 0.75% agarose. The average volume of the spheroids was estimated by 1/2 (short dimension)2 x (long dimension). Anti-NPC BAC5 MAb was labelled with 131I using chloramine-T method. Cytotoxin from Chinese cobra (CT) was conjugated with BAC5 by hetero bifunctional cross-linking reagent (SPDP). The spheroids were treated with either 131I-BAC5 or CT-BAC5 separately or with both of them together by incubating in culture medium. Results: The conjugated rate of BAC5 and CT was 32.4%. CT-BAC5 significantly inhibited the growth of CNE-2 multicellular spheroids comparing with control agent (normal saline) (P 131I-BAC5 did more than CT-BAC5 (P131I-BAC5 with CT-BAC5 treatment showed even stronger destructive effect on the spheroids (vs. normal saline, P 131I-BAC5 with CT-BAC5 is better than either of them working separately

  17. Development and characterization of radioimmunoassay methods for the measurement of iodothyronines (T4, T3 and rT3)

    International Nuclear Information System (INIS)

    The experience acquired in the development of radioimmunoassay for T4, T3 and rT3 in unextrated serum is described. Antisera were produced in rabbits using iodothyronines conjugated to bovine serum albumin: the antisera selected provided the development of sensitive and specific radioassay methods. Stable high activity T3, T4 and rT3 tracers were prepared by iodination of 3,5 T2, T3 and 3,3' T2 by the chloramine-T method, and purified by column chromatography on Sephadex G25. Binding of those iodothyronines to endogenous serum proteins was blocked by including 8-aniline-1-naphtalene sulphonic acid (ANSA) in the T4 and T3 assays and thymerosal in the rT3 assay. Normal values were defined in 46 healthy euthyroid adults of both sexes: T4 = 7,1 +- 1,3μg/dl; T3 = 139 +- 35ng/dl and rT3 = 18,0 +- 7,9ng/dl. (Author)

  18. Identification of nitrosamine precursors from urban drainage during storm events: A case study in southern China.

    Science.gov (United States)

    Bei, Er; Liao, Xiaobin; Meng, Xiangting; Li, Shixiang; Wang, Jun; Sheng, Deyang; Chao, Meng; Chen, Zhuohua; Zhang, Xiaojian; Chen, Chao

    2016-10-01

    The drinking water sources of many cities in southern China are frequently contaminated by upstream urban drainage during storm events, which brings high concentrations of N-nitrosamine (NA) precursors and poses a threat to the safety of drinking water. We conducted two sampling campaigns during the heavy rain season in 2015 in one representative city in southern China. We detected that the concentration of N-nitrosodimethylamine formation potential (NDMA FP) in urban drainage during two storm events was 80-115 ng/L and the total formation potential concentration of nine nitrosamines (TNA9 FP) was 145-165 ng/L. To address the deteriorated water quality, 30 mg/L of powdered activated carbon (PAC) was fed into the water intake. PAC adsorption alone could remove 52% of NDMA FP and 52% of TNA FP, while the subsequent conventional process only removed 8% of TNA FP. We isolated six chemicals (N,N-benzyldimethylamine, 5-[(dimethylamino)methyl]-2-furanmethanol, N,N-dimethyl-3-aminophenol, N,N-dimethylethylamine, Ziram, and N,N-dimethylaniline) and confirmed them to be NA precursors. Among these NA precursors, Ziram was identified for the first time as a NA precursor that is formed via chloramination; its molar yield for NDMA was 6.73 ± 0.40%. PMID:27393968

  19. Selective mono-radioiodination and characterization of a cell-penetrating peptide. L-Tyr-maurocalcine

    Energy Technology Data Exchange (ETDEWEB)

    Ahmadi, Mitra; Bacot, Sandrine; Perret, Pascale; Riou, Laurent; Ghezzi, Catherine [Universite Joseph Fourier, Grenoble (France); INSERM U1039, Grenoble (France). Radiopharmaceutiques Biocliniques; Poillot, Cathy; Cestele, Sandrine [INSERM U836, Grenoble (France). Grenoble Inst. of Neuroscience; Universite Joseph Fourier, Grenoble (France); Desruet, Marie-Dominique [INSERM U1039, Grenoble (France). Radiopharmaceutiques Biocliniques; Couvet, Morgane; Bourgoin, Sandrine; Seve, Michel [CRI-INSERM U823, Grenoble (France). Inst. of Albert Bonniot; Universite Joseph Fourier, Grenoble (France); Waard, Michel de [INSERM U836, Grenoble (France). Grenoble Inst. of Neuroscience; Universite Joseph Fourier, Grenoble (France); Smartox Biotechnologies, Grenoble (France)

    2014-07-01

    Mono-and poly-iodinated peptides form frequently during radioiodination procedures. However, the formation of a single species in its mono-iodinated form is essential for quantitative studies such as determination of tissue concentration or image quantification. Therefore, the aim of the present study was to define the optimal experimental conditions in order to exclusively obtain the mono-iodinated form of L-maurocalcine (L-MCa). L-MCa is an animal venom toxin which was shown to act as a cell-penetrating peptide. In order to apply the current direct radioiodination technique using oxidative agents including chloramine T, Iodo-Gen {sup registered} or lactoperoxidase, an analogue of this peptide containing a tyrosine residue (Tyr-L-MCa) was synthesized and was shown to fold/oxidize properly. The enzymatic approach using lactoperoxidase/H{sub 2}O{sub 2} was found to be the best method for radioiodination of Tyr-L-MCa. MALDI-TOF mass spectrometry analyses were then used for identification of the chromatographic eluting components of the reaction mixtures. We observed that the production of different radioiodinated species depended upon the reaction conditions. Our results successfully described the experimental conditions of peptide radioiodination allowing the exclusive production of the mono-iodinated form with high radiochemical purity and without the need for a purification step. Mono-radioiodination of L-Tyr-MCa will be crucial for future quantitative studies, investigating the mechanism of cell penetration and in vivo biodistribution.

  20. Studies on the mode of action of calciferol. XIII. Development of a radioimmunoassay for vitamin D-dependent chick intestinal calcium-binding protein and tissue distribution

    International Nuclear Information System (INIS)

    A RIA for chick intestinal calcium-binding protein (CaBP) has been developed with a sensitivity of 1 ng. The antiserum was generated in rabbits injected with highly purified vitamin D-dependent chick intestinal CaBP. The assay employs the double antibody technique, and 125I-labeled CaBP was prepared using chloramine T. Low molecular weight peptide hormones and normal rabbit, rat, and human serum proteins show no cross-reactivity in the assay. Measurements of chick intestinal and kidney CaBP by RIA showed a good correlation with measurements of CaBP by the radial immunodiffusion method. The assay is reproducible (interassay variability, 16.3%) and precise (intraassay variability, 4.0%). The concentration of immunoreactive CaBP (iCaBP) in chick serum (2.7 ng/ml serum) can now be measured as early as 8 h after the administration of 6.5 nmol 1,25-dihydroxyvitamin D3; a maximum of 11 ng/ml is reached at 20 h. The level of CaBP in chick serum was found to be dependent on the dose of vitamin D3 or 1,25-dihydroxyvitamin D3 administered to the animal

  1. Studies on the mode of action of calciferol. XIII. Development of a radioimmunoassay for vitamin D-dependent chick intestinal calcium-binding protein and tissue distribution

    Energy Technology Data Exchange (ETDEWEB)

    Christakos, S.; Friedlander, E.J.; Frandsen, B.R.; Norman, A.W.

    1979-05-01

    A RIA for chick intestinal calcium-binding protein (CaBP) has been developed with a sensitivity of 1 ng. The antiserum was generated in rabbits injected with highly purified vitamin D-dependent chick intestinal CaBP. The assay employs the double antibody technique, and /sup 125/I-labeled CaBP was prepared using chloramine T. Low molecular weight peptide hormones and normal rabbit, rat, and human serum proteins show no cross-reactivity in the assay. Measurements of chick intestinal and kidney CaBP by RIA showed a good correlation with measurements of CaBP by the radial immunodiffusion method. The assay is reproducible (interassay variability, 16.3%) and precise (intraassay variability, 4.0%). The concentration of immunoreactive CaBP (iCaBP) in chick serum (2.7 ng/ml serum) can now be measured as early as 8 h after the administration of 6.5 nmol 1,25-dihydroxyvitamin D/sub 3/; a maximum of 11 ng/ml is reached at 20 h. The level of CaBP in chick serum was found to be dependent on the dose of vitamin D/sub 3/ or 1,25-dihydroxyvitamin D/sub 3/ administered to the animal.

  2. Receiving of iodoinsulin with preserved biological activity

    International Nuclear Information System (INIS)

    The paper presents a method of receiving iodoinsulin with preserved biological activity. As a raw material recrystallized bovine insulin produced by ''Polfa'' was used. Chloramine T was used as an oxidizing agent in the iodize reaction. Insulin was marked with 125I or 127I in the rate of molar concentration of NaI and insulin 0.6. The obtained product contained about 0.3 of iodine atom per one insulin molecule. Specific radioactivity of the iodoinsulin was between 77 and 147 μCi/μg. Such an insulin was in over 95% precipitable with trichloroacetic acid. Its immunological reactivity varied from 89% to 100% while biological activity, determined with the consumption of glucose by the fatty tissue of epididymis of rat, was 92% +- 24% of the native insulin activity. Half-life time of 125I insulin in the rat blood circulation was determined. Curve of the isotope disappearance was biphasic. Half-life time of the first phase (shorter one) was 0.64 +- 0.2 minute while the longer phase 8.89 +- 2.16 minutes. (author)

  3. The study of labeling with Iodine-131 of monoclonal antibody anti-CD20 used for the treatment of non-Hodgkin lymphoma; Estudo de marcacao com Iodo-131 de anticorpo monoclonal anti-CD20 na terapia de linfoma nao-Hodgkin

    Energy Technology Data Exchange (ETDEWEB)

    Akanji, Akinkunmi Ganiyu

    2006-07-01

    Lymphomas are malignancies of the lymphatic system, described by Thomas Hodgkin in 1932. Traditionally, lymphomas are classified in two basic groups: Hodgkin disease and non-Hodgkin lymphoma (NHL). Patients with NHL were earlier treated with radiotherapy alone or in combination with immunotherapy using monoclonal antibody anti-CD20 (ex., Rituximab-Mabthera, Roche). However, Radioimmunotherapy is a new modality of treatment for patients with NHL, in which cytotoxic radiation from therapeutic radioisotopes is delivered to tumors through monoclonal antibodies. This study focused on labeling conditions of monoclonal antibody anti-CD20 (Rituximab-Mabthera, Roche) with iodine-131, by direct radioiodination method using Chloramine-T as oxidizing agent. Labeling parameters investigated were: Radiochemical purity (RP), method of purification, incubation time, antibody mass, oxidative agent mass, stability in vitro, stability in vivo, immunoreactivity and biological distribution performed in normal Swiss mouse. Product of high radiochemical purity was obtained with no notable difference between the methods applied. No clear evidence of direct influence of incubation time on radiochemical purity of the labeled antibody was observed. Whereas, a clear evidence of direct influence of activity on radiochemical purity of the labeled antibody was observed when antibody mass was varied. After purification, the labeled product presented radiochemical purity of approximately 100 %. Product of superior radiochemical yield was observed when standard condition of labeling was used. The labeled product presented variation in radiochemical purity using five different stabilizer conditions. The condition in which gentisic acid was combined with freeze appears more suitable and capable of minimizing autoradiolysis of the antibody labeled with high therapeutic activity of iodine-131. The labeled product presented low immunoreactivity when compared to the literature. Biological distribution in

  4. The study of labeling with iodine-131 of monoclonal antibody anti-CD20 used for the treatment of non-Hodgkin lymphoma

    International Nuclear Information System (INIS)

    Lymphomas are malignancies of the lymphatic system, described by Thomas Hodgkin in 1932. Traditionally, lymphomas are classified in two basic groups: Hodgkin disease and non-Hodgkin lymphoma (NHL). Patients with NHL were earlier treated with radiotherapy alone or in combination with immunotherapy using monoclonal antibody anti-CD20 (ex., Rituximab-Mabthera, Roche). However, Radioimmunotherapy is a new modality of treatment for patients with NHL, in which cytotoxic radiation from therapeutic radioisotopes is delivered to tumors through monoclonal antibodies. This study focused on labeling conditions of monoclonal anti-CD20 (ex., Rituximab-Mabthera, Roche) with iodine-131, by direct radioiodination method using Chloramine-T as oxidizing agent. Labeling parameters investigated were: Radiochemical purity (RP), method of purification, incubation time, antibody mass, oxidative agent mass, stability in vitro, immunoreactivity and biological distribution performed in normal Swiss mouse. Product of high radiochemical purity was obtained with no notable difference between the methods applied. No clear evidence of direct influence of incubation time on radiochemical purity of the labeled antibody was observed. Whereas, a clear evidence of direct influence of activity on radiochemical purity of the labeled antibody was varied. After purification the labeled product presented radiochemical purity of approximately 100 %. Product of superior radiochemical yield was observed when standard condition of labeling was used. The labeled product presented variation in radiochemical purity using five different stabilizer conditions. The condition in which gentisic acid combined with freeze appears more suitable and capable of minimizing autoradiolysis of the antibody labeled with freeze appears more suitable and capable of minimizing autoradiolysis of the antibody labeled with high therapeutic activity of iodine-131. The labeled product presented low immunoreactivity when compared to the

  5. The study of labeling with Iodine-131 of monoclonal antibody anti-CD20 used for the treatment of non-Hodgkin lymphoma

    International Nuclear Information System (INIS)

    Lymphomas are malignancies of the lymphatic system, described by Thomas Hodgkin in 1932. Traditionally, lymphomas are classified in two basic groups: Hodgkin disease and non-Hodgkin lymphoma (NHL). Patients with NHL were earlier treated with radiotherapy alone or in combination with immunotherapy using monoclonal antibody anti-CD20 (ex., Rituximab-Mabthera, Roche). However, Radioimmunotherapy is a new modality of treatment for patients with NHL, in which cytotoxic radiation from therapeutic radioisotopes is delivered to tumors through monoclonal antibodies. This study focused on labeling conditions of monoclonal antibody anti-CD20 (Rituximab-Mabthera, Roche) with iodine-131, by direct radioiodination method using Chloramine-T as oxidizing agent. Labeling parameters investigated were: Radiochemical purity (RP), method of purification, incubation time, antibody mass, oxidative agent mass, stability in vitro, stability in vivo, immunoreactivity and biological distribution performed in normal Swiss mouse. Product of high radiochemical purity was obtained with no notable difference between the methods applied. No clear evidence of direct influence of incubation time on radiochemical purity of the labeled antibody was observed. Whereas, a clear evidence of direct influence of activity on radiochemical purity of the labeled antibody was observed when antibody mass was varied. After purification, the labeled product presented radiochemical purity of approximately 100 %. Product of superior radiochemical yield was observed when standard condition of labeling was used. The labeled product presented variation in radiochemical purity using five different stabilizer conditions. The condition in which gentisic acid was combined with freeze appears more suitable and capable of minimizing autoradiolysis of the antibody labeled with high therapeutic activity of iodine-131. The labeled product presented low immunoreactivity when compared to the literature. Biological distribution in

  6. Choice of labeling and cell line influences interactions between the Fab fragment AbD15179 and its target antigen CD44v6

    International Nuclear Information System (INIS)

    Medical imaging by use of immunotargeting generally relies on a labeled molecule binding to a specific target on the cell surface. It is important to utilize both cell-based and time-resolved binding assays in order to understand the properties of such molecular interactions in a relevant setting. In this report we describe the detailed characterization of the interaction properties for AbD15179, a promising CD44v6-targeting antibody fragment for radio-immunotargeting. Influence of labeling and cell-line model on the protein interaction kinetics was assessed using three different labeling approaches (111In, 125I and FITC) on three different squamous carcinoma cell lines. Interactions were measured using time-resolved assays on living cells, and further analyzed with Interaction Map®. Results demonstrated a general biphasic appearance of a high- and a low-affinity binding event in all cases. The relative contribution from these two interactions differed between conjugates. For 125I-Fab, the population of low-affinity binders could be significantly increased by extending the chloramine T exposure during labeling, whereas the 111In-labeling predominantly resulted in a high-affinity interaction. Interactions were also shown to be cell line dependent, with e.g. SCC-25 cells generally mediating a faster dissociation of conjugates compared to the other cell lines. In conclusion, we report both cell line dependent and labeling associated variations in interaction kinetics for AbD15179 binding to CD44v6. This has implications for cell-based kinetic assays and applications based on labeled conjugates in general, as well as in a clinical setting, where each individual tumor may create different kinetic profiles for the same conjugate

  7. Theoretical Studies on F(-) + NH2Cl Reaction: Nucleophilic Substitution at Neutral Nitrogen.

    Science.gov (United States)

    Liu, Xu; Zhang, Jiaxu; Yang, Li; Sun, Rui

    2016-05-26

    The SN2 reactions at N center, denoted as SN2@N, has been recognized to play a significant role in carcinogenesis, although they are less studied and less understood. The potential energy profile for the model reaction of SN2@N, chloramine (NH2Cl) with fluorine anion (F(-)), has been characterized by extensive electronic structure calculations. The back-side SN2 channel dominates the reaction with the front-side SN2 channel becoming feasible at higher energies. The minimum energy pathway shows a resemblance to the well-known double-well potential model for SN2 reactions at carbon. However, the complexes involving nitrogen on both sides of the reaction barrier are characterized by NH---X (X = F or Cl) hydrogen bond and possess C1 symmetry, in contrast to the more symmetric ion-dipole carbon analogues. In the F(-) + NH2Cl system, the proton transfer pathway is found to become more competitive with the SN2 pathway than in the F(-) + CH3Cl system. The calculations reported here indicate that stationary point properties on the F(-) + NH2Cl potential energy surface are slightly perturbed by the theories employed. The MP2 and CAM-B3LYP, as well as M06-2X and MPW1K functionals give overall best agreement with the benchmark CCSD(T)/CBS energies for the major SN2 reaction channel, and are recommended as the preferred methods for the direct dynamics simulations to uncover the dynamic behaviors of the title reaction. PMID:27144809

  8. Transformation of acetaminophen during water chlorination treatment: kinetics and transformation products identification.

    Science.gov (United States)

    Cao, Fei; Zhang, Mengtao; Yuan, Shoujun; Feng, Jingwei; Wang, Qiquan; Wang, Wei; Hu, Zhenhu

    2016-06-01

    As a high-consumption drug in the world, acetaminophen (AAP) has been widely detected in natural waters and wastewaters. Its reactivity and the transformation products formed during chlorination may greatly threaten the safety of drinking water. The reaction kinetics of AAP during chlorination was investigated in this study. The results showed that the reaction kinetics could be well described with a kinetics model of -d[AAP]/dt = k app[AAP]t (0.63)[Cl2]t (1.37). The values of apparent rate constant (k app) were dependent on reaction temperature, ammonium, and pH. With the increase in reaction temperature from 5.0 ± 1.0 to 40.0 ± 1.0 °C, the removal efficiency of AAP increased from 60 to 100 %. When ammonium was present in the solution at 2.0 mg/L, the transformation of AAP was inhibited due to the rapid formation of chloramines. The maximum of k app was 0.58 × 10(2) M(-1) · min(-1) at pH 9.0, and the minimum was 0.27 M(-1) · min(-1) at pH 11.0. A low mineralization of AAP (about 7.2 %) with chlorination was observed through TOC analysis, implying the formation of plenty of transformation products during chlorination. The main transformation products, hydroquinone and two kinds of chlorinated compounds, monochlorinated acetaminophen and dichlorinated acetaminophen, were detected in gas chromatography-mass spectrometry analysis. PMID:26983813

  9. Two Fatal Intoxications with Cyanohydrins.

    Science.gov (United States)

    Zheng, Shuiqing; Yuan, Xiaoliang; Wang, Wei; Liang, Chen; Cao, Fangqi; Zhang, Runsheng

    2016-06-01

    Cyanohydrins, also be called cyanoalcohols, are important industrial precursors to carboxylic acids and some amino acids. Acetone cyanohydrin (ACH) and formaldehyde cyanohydrin (glycolonitrile, FCH), which are the typical examples of cyanohydrins, are classified as extremely hazardous substances. As the cyanohydrins can readily decompose, and it is hard to find cyanohydrins in gastric contents and heart blood, the determination study in biological samples can be divided into two parts: the first is the determination of HCN by using a Prussian blue reaction and the HS-GC-MSD after derivatization by chloramine-T. The second is the determination of acetone or formaldehyde. In this part, headspace gas chromatography with flame ionization detector (HS-GC-FID) and solid phase microextraction (SPME)-gas chromatography with mass spectrometric detectors (GC-MSD) had been used. In this report, we reported two fatal intoxication cases of ACH and FCH; one person was killed by his wife by poisoning his food and the other was suicide by poison. Two real cases of ACH and FCH in human blood and gastric contents have been analyzed by using the above-mentioned method. The Prussian blue reaction was positive in the two cases. The peaks of acetone with retention times of 0.998 min appear in specimens of the deceased are consistent with the retention times of pure acetone. The peaks of formaldehyde with a retention time of 1.658 min appear in heart blood of the deceased, and the retention time of formaldehyde of the liquid is 1.674 min, which are consistent with the retention times of pure formaldehyde (1.673 min). PMID:27026650

  10. The structure of flavin-dependent tryptophan 7-halogenase RebH

    Energy Technology Data Exchange (ETDEWEB)

    Bitto, Eduard; Huang, Yu; Bingman, Craig A.; Singh, Shanteri; Thorson, Jon S.; Phillips, Jr., George N. (UW)

    2010-02-19

    Enzyme catalyzed regio- and stereo-specific halogenations influence the biological activity of a diverse array of therapeutically important natural products, including the antibiotics vancomycin and chloramphenicol as well as the anticancer agents calicheamicin and rebeccamycin. The major class of enzymes responsible for this challenging synthetic reaction, the flavin-dependent halogenases, catalyzes the formation of carbon-halogen bonds using flavin, a halide ion (Cl{sup -}, Br{sup -} or I{sup -}), and O{sub 2}. Recent mechanistic and structural advances achieved with the model flavin-dependent tryptophan 7-halogenases PrnA and RebH have greatly enhanced the level of understanding of this unique reaction. According to these studies, the mechanism for tryptophan halogenation proceeds via FAD(C4a)-OOH activation of a chloride ion into the transient chlorinating species HOCl. The key evidence for the requirement of a transient chlorinating species is the discovery that a {approx}10-{angstrom}-long tunnel separates FAD and tryptophan in the ligand-bound form of PrnA. In a recent compelling study to elucidate the strategy by which RebH controls this highly reactive and indiscriminant oxidant, a Lys79-{var_epsilon}NH-Cl chloramine intermediate was implicated as the actual chlorinating species within RebH and a structural investigation of RebH was reported. Here we report our independent structural analysis of Lechevalieria aerocolonigenes RebH (Uni-Prot accession number Q8KHZ8, 530 amino acids) in its apo-form as well as in a complex with both tryptophan and FAD.

  11. Considerations in the radioiodination and chelation labeling of an antiplatelet monoclonal antibody

    International Nuclear Information System (INIS)

    Radiolabeling of antibodies in particular with iodine nuclides frequently alters their biological behavior and compromises the specificity of binding to the in vivo antigens. Sensitivity to labeling chemistry however, is quite variable for different antibodies. This study was carried out to investigate the various factors affecting the binding to platelets (P) of an anti-P monoclonal antibody, 7E3, following iodination with I-123, I-125, I-131 and chelation labeling with In-111 and Tc-99m. Parameters such as the nature and amount of oxidant, reaction times, substitution level, specific activity etc., were studied. Results showed that each factor in addition to affecting chemical labeling yields also affected the binding of labeled 7E3 to P in whole blood and their blood clearance and clot uptake. With increasing I/7E3 or DTPA/7E3 molar ratios, a progressive decrease in binding to P resulted. Chloramine T (5-10 μg/100 μg 7E3) was superior to other oxidizing agents but the reaction times had to be ≤2 min (labeling yields 70 +- 10%). 7E3 appeared unaffected by specific activities of up to 40 μCi/μg (I-131 and In-111) and 300 μCi/μg (I-123). Satisfactory In-111-, I-131-, or I-123-7E3-P preparations were obtained that show considerable promise for localizing in vivo thrombi. Results of this study and prior experience with other antibodies indicate that in order to achieve maximum efficacy in imaging or therapy applications, individual antibodies may require a careful optimization of labeling procedures with different radionuclides

  12. A study on the metabolic pathway of pregnancy specific beta1-glycoprotein (SP1), 2

    International Nuclear Information System (INIS)

    SP1 was purified from human placentae, and the metabolism of 125I labeled SP1 was studied in non-pregnant and pregnant mice of ICR strain. Purification of SP1 was carried out by the method of Bohn (1971) and Nose (1981) with modifications. A preparation of purified SP1 was labeled with 125I by the Chloramine-T method. 125I-SP1 (0.1 ml of approximately 2.5 x 106 C.P.M./ml radioactivity) was injected into the subcutaneous tissue of both non-pregnant and pregnant mice. The animals were killed at 0.5, 1, 2, 4, 8 and 16 hours after the injection. The organs and tissues were collected, weighed and analysed for accumulated radioactivity. Non-pregnant mice tissue radioactivity exhibited the highest count in the kidney, followed by blood, ovary and uterus, spleen, liver, muscle and fat at 30 min. after the injection; similar tendencies were observed at other times. Radioactivity of the kidney was more than twice that of blood. A blood disappearance curve showed a half life of 8 hours. The radioactive substance was excreted in urine at a very high level from 30 min. to 4 hours, and in the faeces, it peaked at 8 hours. Pregnant mice tissue exhibited the highest count in the kidney, followed by blood, spleen, ovary and uterus, placenta, fat, muscle and fetus at 30 min. A blood disappearance curve showed a half life of about 11 hours. Radioactivity of the placenta exceeded that of blood after about 1.5 hour from the injection and reached a peak at 4 hours. It is suggested from this study that SP1 has an affinity to the placenta and its surroundings and is excreted to urine from blood quickly. (J.P.N.)

  13. Sorafenib-induced hepatocellular carcinoma cell death depends on reactive oxygen species production in vitro and in vivo.

    Science.gov (United States)

    Coriat, Romain; Nicco, Carole; Chéreau, Christiane; Mir, Olivier; Alexandre, Jérôme; Ropert, Stanislas; Weill, Bernard; Chaussade, Stanislas; Goldwasser, François; Batteux, Frédéric

    2012-10-01

    Sorafenib is presently the only effective therapy in advanced hepatocellular carcinoma (HCC). Because most anticancer drugs act, at least in part, through the generation of reactive oxygen species, we investigated whether sorafenib can induce an oxidative stress. The effects of sorafenib on intracellular ROS production and cell death were assessed in vitro in human (HepG2) and murine (Hepa 1.6) HCC cell lines and human endothelial cells (HUVEC) as controls. In addition, 26 sera from HCC patients treated by sorafenib were analyzed for serum levels of advanced oxidation protein products (AOPP). Sorafenib significantly and dose-dependently enhanced in vitro ROS production by HCC cells. The SOD mimic MnTBAP decreased sorafenib-induced lysis of HepG2 cells by 20% and of Hepa 1.6 cells by 75% compared with HCC cells treated with 5 mg/L sorafenib alone. MnTBAP significantly enhanced by 25% tumor growth in mice treated by sorafenib. On the other hand, serum levels of AOPP were higher in HCC patients treated by sorafenib than in sera collected before treatment (P < 0.001). An increase in serum AOPP concentration ≥0.2 μmol/L chloramine T equivalent after 15 days of treatment is a predictive factor for sorafenib response with higher progression free survival (P < 0.05) and overall survival rates (P < 0.05). As a conclusion, sorafenib dose-dependently induces the generation of ROS in tumor cells in vitro and in vivo. The sera of Sorafenib-treated HCC patients contain increased AOPP levels that are correlated with the clinical effectiveness of sorafenib and can be used as a marker of effectiveness of the drug. . PMID:22902857

  14. 99mTc labelled peptides for imaging of peripheral receptors

    International Nuclear Information System (INIS)

    The first trials of 99mTc labelling by direct method using dithionite as a reducing agent (prepared in the freeze-dried form) gave the yields of around 30%. RC-160 labelling with 125I by chloramine-T method resulted in 40-80% labelling yield. Our efforts were focused on BFC approach. HYNIC-TOC and HYNIC-RC-160 conjugates obtained in our laboratory were successfully labelled with 99mTc with the yields over 90%. HPLC and TLC methods were applied for quality control (QC) of the labelled preparation. Methods of in vitro (stability and protein binding) testing of the labelled preparations were adopted to our laboratory conditions. First attempts on dry kit formulation based on HYNIC-TOC conjugates with tricine, tricine/nicotinic acid and EDDA were described. Various amounts of tin (II) (as SnCl2) were added to the kits. Incubation conditions (time, temperature) were investigated. The kits were tested for labelling yield and radiochemical purity. It was shown that the results are at the same level or better than obtained in liquid phase but the procedure of labelling is significantly easier. Kit produced with tricine as co-ligand was labelled with 97% labelling yield after 30 min of incubation at room temperature, which is considered acceptable for diagnostic radiopharmaceutical preparation. Tricine/nicotinic acid kit requires heating to get labelling of around 95%. Similarly EDDA kit gives around 70% labelling after 30 min incubation at 80 deg. C. Further experiments on optimal kit composition and stability are required. Results of DOTA-RC-160 labelling with 90Y show that this isotope, manufactured by Radioisotope Centre POLATOM, can be successfully used for medical applications. (author)

  15. Relation between chlorine with the quality of crude water

    International Nuclear Information System (INIS)

    Chlorine as disinfection agent in drinking water was used widely since it was successfully been practiced in drinking water in Jersey City, 1908. Mostly, water treatment plants in Malaysia were using chlorine as disinfection agent to kill pathogen and contaminated materials that can be dangerous to consumer. Because of chlorine was a strongly disinfection agent, it also can react with another chemical components such as manganese, hydrogen, sulfides, ammonia and phenol in water. These reactions happen very fast, and chlorine will not react as disinfection agent unless all the organic and inorganic substitution presented in water reacts with chlorine. These reactions between components will increase demand of chlorine in water. The demand of chlorine in water must be filled before the free radical chlorine occurred. These free radical chlorine will decay into hypochlorous acid and hypochlorite ion that so important in disinfection process to kill pathogens and pollutants in water. Most of water treatment plant to maintain free chlorine up to 0.2 mg/ L in distribution system to consumer. These researches involved determination of parameters that can be trusted to react with the chlorine in nine sampling station along Semenyih River and four stations in water treatment plants. These parameters were determined from ammonia, cyanides, sulfides, phenol, phosphorus, nitrite, manganese, iron and sum of organic carbons. Overall, these researches concluded that ammonia and sum of organic carbons were the most compounds that react with the chlorine to produce tryhalometane and chloramines. Besides that, the concentration of cyanides compounds, sulfide, phenol, phosphorus, nitrite, manganese and iron also decrease after the chlorination process. Results can used to evaluate demanding levels of chlorine in Semenyih River. (author)

  16. New bisphosphonate labeled with Iodine-131 for the palliative therapy for bone metastases pain

    International Nuclear Information System (INIS)

    The aim of this work was to obtain new bisphosphonate marked with 131I suitable for palliative treatment of bone metastases pain characteristics. Materials and Methods: It started with aromatic amino acids and the synthesis consisted of three stages: 1) Protection of amino groups by acetylation; 2) phosphonation protected amino acids with a mixture of phosphorous acid and phosphorus pentachloride; 3) Lack of protection of the amino groups by basic hydrolysis. The compounds obtained were characterized by IR, 1H NMR, RMN13-C mass. Los spectrometry bisphosphonic acids obtained were labeled with 131I using chloramine T and iodogen as oxidants. Stability of labeled compounds in aqueous solution was studied serum. 3 mg of 2-amino-3- (4-hydroxyphenyl) -1-hydroxypropyl-1,1-bisphosphonic acid labeled of 131I were administered to male wistar rats (170-190 g) through a lateral tail vein. The scintigraphic study was conducted at 2, 6 and 12 hours. Results: The yield of the reactions of the amino group protection four compounds ranged from 75 to 80%, while the phosphonation was between 50 and 60%. The radiochemical purity of 2-amino-3- (4-hydroxyphenyl) -1-hydroxypropyl-1,1- bisphosphonic acid labeled with 131I was (91.5 ± 1.4)% and its stability was satisfactory for 72h. Scintigraphic images suggest excretion by the kidneys of the compound and from 12 h post-administration begin to visualize bone structures of the animal, suggesting that the compound exhibits affinity for these tissues. Conclusions: A novel synthesis method with modifications that yielded the sodium salts of bisphosphonic acids starting from the respective aromatic amino acids was developed. 2-amino-3- (4-hydroxyphenyl) -1-hydroxypropyl-1,1-bisphosphonic acid 131I labeled was stable up to 72h and showed affinity for bone tissue. (author)

  17. Biochemical and pharmacological studies of native and irradiated crotamine with gamma radiation of Co60

    International Nuclear Information System (INIS)

    Ionizing radiation can change the molecular structure and affect the biological properties of biomolecules. This has been employed to attenuate animal toxins. Crotamine is a strongly basic polypeptide from South American rattlesnake venom, composed of 42 amino acid residues. It induces skeletal muscle spasms, leading to a spastic paralysis of hind limbs in mice. The objective was to carry out biochemical and pharmacological studies of native and irradiated crotamine with Co. Crotamine was purified from Crotalus durissus terrificus venom by Sephadex G-100 gel filtration followed by ion exchange chromatography, using a Fast performance Liquid Chromatography (FPLC) system. It was irradiated at 2 mg/ml in 0.15 m NaCl with 2.0 kGy gamma radiation emitted by a Co source. Native and irradiated crotamine were evaluated by biochemical characterization, toxic activity (LD50), and biodistribution. The native and irradiated crotamine were labeled with 29.6 MBq of I using chloramine T method and separated in a Sephadex G-50 column. Male Swiss mice (35 @ 5 g) were injected IP with 0.1 mL (2.4x10 cpm/mouse) of I native crotamine or with 0.4 mL (1.3 x 10 cpm/mouse) of I irradiated crotamine. The animals were sacrificed by ether inhalation at 0.08, 0.25, 0.5,1, 2, 3, 4, 8, 12, and 24 hours. Blood, spleen, liver, kidneys, brain, lungs, heart, and skeletal muscle were collected in order to determine radioactivity content. The results showed that gamma radiation did not change protein concentration, electrophoretic profile, or protein primary structure, although differences could be seen by spectroscopic techniques. Gamma radiation reduced crotamine toxicity, but did not eliminate bioactivity. Biodistribution studies showed that native and irradiated crotamine have hepatic metabolism and renal elimination. Native and irradiated crotamine have an affinity to skeletal muscle and did not cross the blood-brain barrier. (author)

  18. Biochemical and ultrastructural processing of [125I]epidermal growth factor in rat epidermis and hair follicles: accumulation of nuclear label

    International Nuclear Information System (INIS)

    Although the intracellular ultrastructural processing of epidermal growth factor (EGF) and its receptor have been described in cell culture systems, very few studies have examined this phenomenon in intact tissues. We have examined the ultrastructural and biochemical handling of [125I]EGF in the epidermis and hair follicle bulb of intact, viable, 3- to 5-day-old rat skin the EGF receptor distribution of which has already been documented and in which EGF has been shown to be biologically active. After incubation of explants with 10 nM [125I]EGF for 2.5 h at 25 degrees or 37 degrees C, radiolabel was detected over the basal cells of the epidermis and hair follicle outer root sheath, confirming previous light microscope observations. More specifically, silver grains were observed near coated and uncoated plasma membrane and coated membrane invaginations, Golgi apparatus, lysosomal structures, and nuclei. Sodium azide inhibited internalization of label, whereas a series of lysosomal inhibitors (chloroquine, monensin, and iodoacetamide) caused a slight increase in silver grains associated with lysosomal vesicles and a decrease in nuclear label. Biochemical analysis indicated that greater than 35% of radioactivity following incubation at 37 degrees C was in the form of degraded [125I]EGF fragments and that inclusion of chloroquine, monensin, and iodoacetamide reduced this value to 20.8%, 8.6%, and 4.0%, respectively. In addition, chloramine T-prepared [125I]EGF was found to be covalently cross-linked with low efficiency to a protein having the molecular weight of the EGF receptor. These data are discussed in the light of the effects of EGF on epithelial cell proliferation in skin

  19. Development of anti-CD30 radioimmunoconstructs (RICs) for treatment of Hodgkin's lymphoma. Studies with cell lines and animal studies

    International Nuclear Information System (INIS)

    Objectives: comparison of the binding affinity to a CD30-positive Hodgkin lymphoma (HL) cell line and biodistribution in HL bearing mice of new anti-CD30 radioimmunoconjugates (RICs) of varying structure and labelling nuclides. Methods: The antibodies Ki-4 and 5F11 were radioiodinated by the chloramine T method or labelled with 111In via p-NCS-Benzyl-DOTA. In addition, the Ki-4-dimer was investigated in the iodinated form. The RICs were analyzed for retained immunoreactivity by immunochromatography. In-vitro binding studies were performed on CD30-positive L540 cell lines. For in-vivo biodistribution studies, SCID mice bearing human HL xenografts were injected with the various radio-immunoconjugates. After 24 h, activities in the organs and tumour were measured for all 5 RICs. Tumour-free animals were studied in the same way with 131I-Ki-4 24 h p. i. The three RICs with the highest tumour/background ratios 24 h p.i. (131I-Ki-4, 131I-5F11, 111In-bz-DOTA-Ki-4) were analysed further at 48 h and 72 h. Results: all the RICs were successfully labelled with high specific activities (28-47 TBq/mmol) and sufficient radiochemical yields (> 80%). Scatchard plot analysis proved high tumour affinity (KD = 20-220 nmol/l). In-vivo tumour accumulation in % of injected dose per g tissue (% ID/g) lay between 2.6 (131I-5F11) and 12.3 % ID/g (131I-Ki-4) with permanently high background in blood. Tumour/blood-ratios of all RICs were below one at all time points. Conclusions: in-vitro tumour cell affinities of all RICs were promising. However, in-vivo biokinetics tested in the mouse model did not meet expectations. This highlights the importance of developing and testing further new anti-CD30 conjugates. (orig.)

  20. A radioimmunoassay detecting the borine leukaemia virus transmembrane protein gp30 and anti-gp30 antibodies in the serum of cattle

    International Nuclear Information System (INIS)

    From virus-infected fetal lamb kidney (FLK) cells a relatively homogeneous envelope transmembrane protein gp30 of bovine leukemia virus (BLV) was isolated. As shown by a partial sequence analysis of the N-terminus of this protein, the gp30 preparation contained only traces (less than 5%) of p24 gag protein: rabbit anti-gp30 serum did not cross react with the BLV proteins gp51, p12, p151, p152 and p10 but reacted weakly with the p24 polypeptide. 125I-labelled gp30 (chloramine-T) was precipitated with the serum of BLV-infected cattle. Nonlabelled preparation of gp30 competitively inhibited the reaction of 125I-labelled gp30 with natural antibodies. 193 cattle sera were investigated by liquid phase radioimmunoassay (RIA) using 125I-gp30, gp51 and p24 antigens. Sixteen noninfected cattle sera were negative in all tests. The 177 serum samples of BLV-infected animals were examined to the diagnostic value of the three tests. Of these, 175 were positive in gp51 RIA, 172 in p24 RIA and 164 in gp30 RIA. In all three tests, 159 sera were positive while 18 sera, mostly coming from animals with normal leukocyte counts, were positive only either with gp51 or p24, or were double positive with either gp51/p24 or gp51/gp30. It is concluded that gp51 RIA is superior to both gp30 and p24 RIA and that gp30 RIA will be useful for investigating the role of gp30 in virus pathogenicity. (author). 2 figs., 2 tabs., 33 refs

  1. Exhaled nitric oxide and airway hyperresponsiveness in workers: a preliminary study in lifeguards

    Directory of Open Access Journals (Sweden)

    Massin Nicole

    2009-12-01

    Full Text Available Abstract Background Airway inflammation and airway hyperresponsiveness (AHR are two characteristic features of asthma. Fractional exhaled nitric oxide (FENO has shown good correlation with AHR in asthmatics. Less information is available about FENO as a marker of inflammation from work exposures. We thus examined the relation between FENO and AHR in lifeguards undergoing exposure to chloramines in indoor pools. Methods 39 lifeguards at six indoor pools were given a respiratory health questionnaire, FENO measurements, spirometry, and a methacholine bronchial challenge (MBC test. Subjects were labeled MBC+ if the forced expiratory volume (FEV1 fell by 20% or more. The normalized linear dose-response slope (NDRS was calculated as the percentage fall in FEV1 at the last dose divided by the total dose given. The relation between MBC and FENO was assessed using logistic regression adjusting on confounding factors. The association between NDRS and log-transformed values of FENO was tested in a multiple linear regression model. Results The prevalence of lifeguards MBC+ was 37.5%. In reactors, the median FENO was 18.9 ppb (90% of the predicted value vs. 12.5 ppb (73% predicted in non-reactors. FENO values ≥ 60% of predicted values were 80% sensitive and 42% specific to identify subjects MBC+. In the logistic regression model no other factor had an effect on MBC after adjusting for FENO. In the linear regression model, NDRS was significantly predicted by log FENO. Conclusions In lifeguards working in indoor swimming pools, elevated FENO levels are associated with increased airway responsiveness.

  2. Evaluating fluorescence spectroscopy as a tool to characterize cyanobacteria intracellular organic matter upon simulated release and oxidation in natural water.

    Science.gov (United States)

    Korak, Julie A; Wert, Eric C; Rosario-Ortiz, Fernando L

    2015-01-01

    Intracellular organic matter (IOM) from cyanobacteria may be released into natural waters following cell death in aquatic ecosystems and during oxidation processes in drinking water treatment plants. Fluorescence spectroscopy was evaluated to identify the presence of IOM from three cyanobacteria species during simulated release into natural water and following oxidation processes (i.e. ozone, free chlorine, chloramine, chlorine dioxide). Peak picking and the fluorescence index (FI) were explored to determine which IOM components (e.g., pigments) provide unique and persistent fluorescence signatures with minimal interferences from the background dissolved organic matter (DOM) found in Colorado River water (CRW). When IOM was added to ultrapure water, the fluorescence signature of the three cyanobacteria species showed similarities to each other. Each IOM exhibited a strong protein-like fluorescence and fluorescence at Ex 370 nm and Em 460 nm (FDOM), where commercial fluorescence sensors monitor. All species also had strong phycobiliprotein fluorescence (i.e. phycocyanin or phycoerythrin) in the higher excitation range (500-650 nm). All three IOM isolates had FI values greater than 2. When IOM was added to CRW, phycobiliprotein fluorescence was quenched through interactions between IOM and CRW-DOM. Mixing IOM and CRW demonstrated that protein-like and FDOM intensity responses were not a simple superposition of the starting material intensities, indicating that interactions between IOM and CRW-DOM fluorescing moieties were important. Fluorescence intensity in all regions decreased with exposure to ozone, free chlorine, and chlorine dioxide, but the FI still indicated compositional differences compared to CRW-DOM. The phycobiliproteins in IOM are not promising as a surrogate for IOM release, because their fluorescence intensity is quenched by interactions with DOM and decreased during oxidation processes. Increases in both FDOM intensity and FI are viable qualitative

  3. Seasonal evaluation of the presence of 46 disinfection by-products throughout a drinking water treatment plant.

    Science.gov (United States)

    Serrano, Maria; Montesinos, Isabel; Cardador, M J; Silva, Manuel; Gallego, Mercedes

    2015-06-01

    In this work, we studied a total of 46 regulated and non-regulated disinfection by-products (DBPs) including 10 trihalomethanes (THMs), 13 haloacetic acids (HAAs), 6 halonitromethanes (HNMs), 6 haloacetonitriles (HANs) and 11 aldehydes at different points in a drinking water treatment plant (DWTP) and its distribution network. Determining an increased number of compounds and using accurate, sensitive analytical methodologies for new DBPs can be useful to overcome some challenges encountered in the comprehensive assessment of the quality and safety of drinking water. This paper provides a detailed picture of the spatial and seasonal variability of DBP concentrations from raw water to distribution network. Samples were collected on a monthly basis at seven different points in the four seasons of a year to acquire robust data for DBPs and supplementary quality-related water parameters. Only 5 aldehydes and 2 HAAs were found in raw water. Chlorine dioxide caused the formation of 3 new aldehydes (benzaldehyde included), 5 HAAs and chloroform. The concentrations of DBPs present in raw water were up to 6 times higher in the warmer seasons (spring and summer). The sedimentation process further increased their concentrations and caused the formation of three new ones. Sand filtration substantially removed aldehydes and HAAs (15-50%), but increased the levels of THMs, HNMs and HANs by up to 70%. Chloramination raised the levels of 8 aldehydes and 7 HAAs; also, it caused the formation of monoiodoacetic acid, dibromochloromethane, dichloroiodomethane and bromochloroacetonitrile. Therefore, this treatment increases the levels of existing DBPs and leads to the formation of new ones to a greater extent than does chlorine dioxide. Except for 5 aldehydes, the 23 DBPs encountered at the DWTP exit were found at increased concentrations in the warmer seasons (HAAs by about 50% and THMs by 350%). PMID:25771439

  4. Role of the metabolism of parathyroid hormone. [Rats

    Energy Technology Data Exchange (ETDEWEB)

    Teitelbaum, Anne P.

    1978-01-01

    The heterogeneity of parathyroid hormone (PTH) in plasma has prompted investigations of the metabolism of PTH and its relationship to hormone action. The time course of tissue distribution and metabolism of electrolytically iodinated PTH (E-PTH) previously shown to retain biological activity was compared with that of inactive PTH iodinated with Chloramine-T (CT-PTH). Labeled PTH (0.4 ..mu..g) was injected in the saphenous veins of anesthetized rats which were sacrificed at 1, 3, 5, 10, and 20 min. Tissue extracts from kidney, liver, and serum were chromatographed to separate intact PTH from its metabolites. In the kidney, the initial rate of degradation of E-PTH was greater than that of CT-PTH. The difference in initial rates of metabolism may be due, in part, to receptor-specific hydrolysis on peritubular cell membranes which selectively act on biologically active PTH molecules. PTH-responsive adenyl cyclase activity in isolated kidney cortex plasma membranes was measured and PTH metabolism was monitored simultaneously. When degradation was completely blocked by histone f/sub 3/ (1 mg/ml), adenyl cyclase activity was significantly increased over control. In addition, when adenyl cyclase activity was negligible, the rate of PTH degradation by the membranes was not significantly diminished. Consistent with the in vivo data was the observation that E-PTH is metabolized by these membranes at a greater rate than CT-PTH. The data demonstrate the existence of a receptor-specific metabolism at sites which are independent of PTH receptor mediated adenyl cyclase activity.

  5. Rhodamine-123: Radioiodination and evaluation as an agent for imaging and radiotherapy of certain tumors

    International Nuclear Information System (INIS)

    Rhodamine-123 (Rh-123) is a cationic lypophilic fluorescent dye which localizes in the mitochondria of living cells. The compound subsequently clears through normal cells but is selectively retained in carcinoma cells. As a result, the compound exhibits anticarcinoma activity both in vitro and in vivo. This high selectivity prompted us to evaluate Rhodamine-123 as an agent for imaging and radiotherapy. Accordingly in the present study Rh-123 was labeled with iodine-125 by chloramine-T. Tissue distributions were studied for C-3Hf/SED brown mice bearing 1 cm diameter implanted SCC VII carcinoma; CDF-1 mice with MB49 bladder carcinoma, nude mice with human CX-1 colon carcinoma and brown mice with murine mammary tumor. The results indicated that (i) initially the radioactivity was taken up by the liver (3.4%), thyroid (3.8%), kidney (2.3%) and tumor (0.8%); (ii) the radioactivity from all the normal tissues cleared within 24 hours but not from the tumors (iii) in tumors the radioactivity remained unchanged. This resulted in higher tumor/blood (1.2%) and tumor/muscle (4.2%) ratios which allows detection of the tumors by gamma camera imaging techniques. In the case of nude mice with human imaging CX-1 colon carcinoma and brown mice with murine mammary tumor the tumor/muscle ratios were interestingly much higher - 8.9% and 9.3%, respectively. These results clearly show that radioiodinated Rh-123 is a potential agent for imaging and radiotherapy of certain tumors

  6. Long-lived reactive species formed on proteins induce changes in protein and lipid turnover.

    Science.gov (United States)

    Davies, Michael

    2014-10-01

    Proteins are major targets for oxidative damage in vivo due to their high abundance and rapid rates of reaction with both one-electron (radical) and two-electron oxidants (e.g. singlet oxygen, hypochlorous acid, peroxynitrous acid, reactive aldehydes). The turnover of both native and modified proteins is critical for maintenance of cell homeostasis, with this occurring via multiple pathways including proteasomes (for cytosolic species), the Lon protease (in mitochondria), and the endo-lysosomal systems (both extra- and intra-cellular species). Evidence has been presented for both enhanced and diminished rates of catabolism of modified proteins, as well as altered turnover of native (unmodified) proteins as a result of damage to these systems, potentially as a result of the accumulation of damaged proteins. In recent studies we have shown that long-lived reactive species forms on proteins (hydroperoxides, chloramines and aldehydes) can modify the activity of proteasomal and lysosomal enzymes. Some of the above species are efficient inhibitors of the tryptic and chymotryptic activities of the 26S proteasome, as well as lysosomal cathepsin and acid lipase activities. These are key species in the turnover of both proteins and lipoproteins. The loss of enzyme activity is accompanied in many cases, by oxidation of critical thiol residues via molecular reactions. For reactive aldehydes (either free or protein-bound) direct enzyme inhibition can occur as well as modulation of protein levels and, in the case of lysosomes, changes in lysosomal numbers. Overall, these data indicate that the formation of reactive species on proteins can modulate cell function by multiple pathways including interference with the turnover of native proteins (including critical cell signalling molecules) and alterations in the rate of clearance of modified proteins. Both pathways may contribute to the development of a number of human pathologies associated with oxidative damage. PMID:26461411

  7. Occurrence and profiling of multiple nitrosamines in source water and drinking water of China.

    Science.gov (United States)

    Wang, Wanfeng; Yu, Jianwei; An, Wei; Yang, Min

    2016-05-01

    The occurrence of multiple nitrosamines was investigated in 54 drinking water treatment plants (DWTPs) from 30 cities across major watersheds of China, and the formation potential (FP) and cancer risk of the dominant nitrosamines were studied for profiling purposes. The results showed that N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA) and N-nitrosodi-n-butylamine (NDBA) were the most abundant in DWTPs, and the concentrations in source water and finished water samples were not detected (ND) -53.6ng/L (NDMA), ND -68.5ng/L (NDEA), ND -48.2ng/L (NDBA). The frequencies of detection in source waters were 64.8%, 61.1% and 51.8%, and 57.4%, 53.7%, and 37% for finished waters, respectively. Further study indicated that the FPs of the three main nitrosamines during chloramination were higher than those during chlorination and in drinking water. The results of Principal Components Analysis (PCA) showed that ammonia was the most closely associated factor in nitrosamine formation in the investigated source water; however, there was no significant correlation between nitrosamine-FPs and the values of dominant water-quality parameters. The advanced treatment units (i.e., ozonation and biological activated carbon) used in DWTPs were able to control the nitrosamine-FPs effectively after disinfection. The target pollutants posed median and maximum cancer risks of 2.99×10(-5) and 35.5×10(-5) to the local populations due to their occurrence in drinking water. PMID:26896577

  8. The development of a human calcitonin radioimunoassay, with 'in house' reagent production, for application to the early diagnosis of medullary thyroid carcioma

    International Nuclear Information System (INIS)

    Reagent production for human Calcitonin (hCT) Radioimmunoassay (RIA) was carried out in our laboratory starting from a kind donation of human synthetic preparation from CIBA (Basel, Switzerland). This product was used for anti-hCT antibody production in rabbits and guinea-pigs and for radioiodination, according to two different methods: classical and stoichiometric Chloramine T techniques. The use of Sephadex G-50 in tracer purification allowed the obtainement of 125I-hCT free of high molecular weight contaminats. A repurification on polyacrylamide gel electrophoresis provided 125I-hCT of higher specific activity that presented specific binginds, to good quality antisera, of the same order of imported tracers (∼ 45%). Different antisera were obtained in rabbits and quinea-pigs, but only one (GP2-IPEN) could be used in such a dilution (1:4000) to provide highly sensitive curves (minimal detectable concentration < 70 pg/ml) presenting, however, very low specific bindings (7-10%). For this reason, in order to be able to set up a regular quality control of our hCT-RIA technique, an antiserum kindly donated by the Karolinska Institute (Stockholm, Sweden) was used. This way, through the use of an higher antibody dilution (1:8000), higher specific bindings (20-30%), higher sensitivies (< 30 pg/ml) and satisfactory precision were obtained. We consider this study a first approach to a complete national production of hCT-RIA reagents, that, at present moment, depends practically only from the obtainement of a high avidity anti-hCT antiserum. More has to be done on accuracy and correct clinical application of this assay to the screening of the familial form of Medullary Thyroid Carcinoma. We also emphasize the fact, due to our limited financial possibilities, all the work was carried out with great economy, taking advantage of previously set up techniques and of the experience already acquired in this field of work. (author)

  9. Synthesis and enantiomeric evaluation of radiolabelled methyl phenidate for the study of dopamine reuptake sites

    International Nuclear Information System (INIS)

    Full text: Neurological diseases such as Parkinson's Disease and associated Movement Disorders have been characterised by reductions in the number of dopamine re-uptake sites or dopamine transporters (DAT) on presynaptic neurons in the striatum. Radiolabelled drugs which display specific and selective binding to the DAT has thus found clinical utility in medical imaging. The psychomotor stimulant methyl phenidate (MP) or Ritalin 1 and several derivatives have demonstrated high affinity binding to these DAT where they exert their pharmacological action. MP possesses two chiral centers with its pharmacological activity being attributed to the dl-threo diastereomer, the dl-erythro being inactive. Furthermore, imaging studies using Positron Emission Tomography (PET) with carbon-11 radiolabelled MP confirmed the d-threo enantiomer to be most active. In vitro studies indicate that compounds substituted with either bromine or iodine in the 3 position of the aromatic ring exhibit high affinity and selective binding to DAT and were thus targeted for radiolabelling with both the PET tracer Bromine-76 as well as the SPECT tracer lodione-123. Threo methyl phenidate and its halogenated derivatives were prepared by the condensation of 3-bromophenylacetonitrile and 2-bromopyridine according to modified literature methods. Radiohalogenation with either 76Br or 123I was achieved by halodestannylation reactions of the corresponding tributyl stannane precursor in the presence of chloramine-T as the oxidant. Purification by C-18 reverse phase HPLC gave the dl-threo product in 70-80% radiochemical yield and in greater than 95% radiochemical purity. Separation of the d and / enantiomers was achieved by chiral HPLC. Biodistribution studies in rodents indicated high uptake of radioactivity in tissues with known DAT sites. PET and SPECT imaging studies in primates indicated high uptake in the striatum compared to the cerebellum reference tissue. The synthesis, diastereomeric separation

  10. Role of the metabolism of parathyroid hormone

    International Nuclear Information System (INIS)

    The heterogeneity of parathyroid hormone (PTH) in plasma has prompted investigations of the metabolism of PTH and its relationship to hormone action. The time course of tissue distribution and metabolism of electrolytically iodinated PTH (E-PTH) previously shown to retain biological activity was compared with that of inactive PTH iodinated with Chloramine-T (CT-PTH). Labeled PTH (0.4 μg) was injected in the saphenous veins of anesthetized rats which were sacrificed at 1, 3, 5, 10, and 20 min. Tissue extracts from kidney, liver, and serum were chromatographed to separate intact PTH from its metabolites. In the kidney, the initial rate of degradation of E-PTH was greater than that of CT-PTH. The difference in initial rates of metabolism may be due, in part, to receptor-specific hydrolysis on peritubular cell membranes which selectively act on biologically active PTH molecules. PTH-responsive adenyl cyclase activity in isolated kidney cortex plasma membranes was measured and PTH metabolism was monitored simultaneously. When degradation was completely blocked by histone f3 (1 mg/ml), adenyl cyclase activity was significantly increased over control. In addition, when adenyl cyclase activity was negligible, the rate of PTH degradation by the membranes was not significantly diminished. Consistent with the in vivo data was the observation that E-PTH is metabolized by these membranes at a greater rate than CT-PTH. The data demonstrate the existence of a receptor-specific metabolism at sites which are independent of PTH receptor mediated adenyl cyclase activity

  11. In vitro selection of beans (Phaseolus vulgaris) from Costa Rica for resistance to fungal pathogen Thanatephorus cucumeris (Rhizoctonia solani)

    International Nuclear Information System (INIS)

    The research has been realized in the Laboratory of Plant Pathology and Laboratory of Plant Tissue Cultures of the Department of Botany in the Palacky University, Olomouc during the period 3 September - 21 December 2007. In vitro cultivation of beans seeds.The culture medium AC agar (Sigma) was used for Thanatephorus cucumeris. The next three isolates from Costa Rica were tested: 007-3242, 007-3241, 007-3077. For each pathogen isolate three different doses were evaluated: 1%, 5% and 10%. The medium was added before it was autoclaved. Two bean varieties (Brunca /black color/ and Bribri /red color/) were used during this procedure. In order to cultivate the bean seeds the Murashige/Skoog (MS) (Duchefa) culture medium was used. The bean seeds were sterilized with Chloramine B (2.5%) for 30 min, washing them three times with distilled sterile water and then leaving the seeds into distilled sterile water for 24 hours. The seed coat was eliminated, and then the embryos were extirpated, and placed in Petri dishes for two days, after two days of incubation the roots were cut and transferred to Erlenmeyer flasks. They were cultivated in the growth chamber at a temperature of 24 + 2 deg. C and a photoperiod of 16 hours /8 day/night. The evaluations were made during the 30, 40 and 50 days of incubation. The spray method was used in order to inoculate Thanatephorus cucumeris from the in vitro bean seedlings. After three weeks of incubation the seedlings were inoculated (by using a glass sprayer) with T. cucumeris (treatments of 1%, 5%, 10%, 2 ml per/ Erlenmeyer flask) in aseptic conditions. The evaluation was made 12 days after the inoculation. The results obtained so far are preliminary, the collected data needs to be analyzed statistically, so it can be published this year. (author)

  12. Subunit structure of the follitropin receptor

    International Nuclear Information System (INIS)

    Both of the α and β subunits of intact human follitropin (FSH) were radioiodinated with 125I-FSH-sodium iodide and chloramine-T, and could be resolved on polyacrylamide gels (SDS-PAGE). The electrophoretic mobility of radioiodinated FSH α and β subunits as well as the αβ dimer changed markedly depending on the concentration of reducing agents. 125I-FSH (Ka = 1.4 x 1010 M-1), complexes to the receptor on procine granulosa cells or in Triton X-100 extracts, was affinity-crosslinked with a cleavable (nondisulfide) homobifunctional reagent, bis[2-(succinimidooxycarbonyloxy)ethyl]sulfone, solubilized in sodium dodecyl sulfate with or without reducing agents, and electrophoresed. Crosslinked samples revealed three additional bands of slower electrophoretic mobility, corresponding to 65 (unreduced 62), 83 (unreduced 76) and 117 (unreduced 110)kDa, in addition to hormone bands. Formation of the three bands requires the 125I-FSH hormone to bind specifically to the receptor with subsequent cross-linking. The rate of formation and cleavage of the cross-linked complexes indicated a sequential and incremental addition of 22, 18, and 34 kDa components to the FSH αβ dimer. The results of reduction of cross-linked complexes demonstrated the existence of disulfide linkage between the three components. FSH was photoactively derivatized with N-hydroxysuccinimide ester of 4-azidobenzolyl-glycine and radioiodinated for photoaffinity labeling. When derivatized 125I-FSH (Ka = 1.12 1010 M-1) bound to the cell was photolyzed for cross-linking and resolved on the SDS-PAGE, two new bands (106 and 61 kDa) under reducing condition appeared in addition to the hormone bands. Upon reduction with dithiotheitol and second-dimensional electrophoresis, the unreduced 104 kDa (reduced 106 kDa) band released two small components 31 and 14 kDa

  13. 原料奶粉及乳饮料中L-羟脯氨酸的含量测定%Determination of L-hydroxyproline in raw milk powder and milk drink

    Institute of Scientific and Technical Information of China (English)

    陈铭中; 钟旭美; 胡洪森

    2011-01-01

    The method of P-dimethylaminobenzaldehyde spectrophotom etry was used to determine L-hydroxyproline in raw milk powder and milk drink.The result was stable and the recovery rate was high.After hydrolyzed with acid,L-hydroxyproline was released and oxidized by chloramine T.L-hydroxyproline oxide reacted with P-dimethylaminobenzaldehyde and formed red compounds,the absorbance was detected at 580 nm.The method was simple and accurate.Compared with other detecting methods,the expense of it was smaller.It could provide reference for enterprises to detect whether product was adulterated hydrolyzed protein in raw milk powder and milk drink.%采用对二甲氨基苯甲醛分光光度法测定奶粉及乳饮料中L-羟脯氨酸,具有较好的稳定性。奶粉及乳饮料经浓盐酸水解,得到的L-羟脯氨酸经过氯胺T氧化,与对二甲氨基苯甲醛反应生成红色物质,在558nm下测定吸光值。该方法操作简单、准确率高、检测费用相对少,可用于企业奶粉原料掺水解蛋白及产品中是否掺有水解蛋白的检测提供依据。

  14. Identification of the binding subunit of the D/sub 1/-dopamine receptor by photoaffinity crosslinking

    Energy Technology Data Exchange (ETDEWEB)

    Amlaiky, N.; Berger, J.G.; Chang, W.; McQuade, R.D.; Caron, M.G.

    1986-03-01

    A derivative of the potent D/sub 1/ antagonist SCH-23390 has been synthesized. This compound, (R,S)-1-(m-aminophenyl)-7-chloro-8-hydroxy-3-methyl-2,3,4,5-tetrahydro-1H-3-benzazepine (SCH-38548), has been radioiodinated by a chloramine T procedure yielding 3 radioiodinated products. One of these separated isomers (R/sub f/ = 0.35; CH/sub 2/Cl/sub 2/:MEOH:TEA; 82.5:17.5:0.1 on TLC) binds reversibly to rat striatal membranes with high affinity (K/sub D/ approx. 80 pM) appropriate stereoselectivity and D/sub 1/-dopaminergic specificity. (/sup 125/I)SCH-38548 can be covalently incorporated into a peptide of M/sub r/ approx. 72,000 using the heterobifunctional crosslinking reagent N-succinimidyl-6-(4'-azido-2'-nitro-phenylamino) hexanoate. Covalent incorporation of (/sup 125/I) SCH-38548 into the M/sub r/ approx. 72,000 peptide can be blocked by dopaminergic agents with D/sub 1/-dopaminergic specificity (for agonists: SKF 38393 > apomorphine > dopamine; for antagonists: SCH-23390 > cis-flupentixol >>> trans-flupentixol). The D/sub 1/-dopaminergic selectivity and specificity of the labeling was further demonstrated by the fact that other antagonists such as domperidone, ketanserin, phentolamine and alprenolol did not compete for the covalent labeling of the M/sub r/ approx. 72,000 peptide. This new radioligand should be useful in the molecular characterization of the D/sub 1/-dopaminergic receptor from various sources.

  15. Treatment of synthetic urine by electrochemical oxidation using conductive-diamond anodes.

    Science.gov (United States)

    Dbira, Sondos; Bensalah, Nasr; Bedoui, Ahmed; Cañizares, Pablo; Rodrigo, Manuel A

    2015-04-01

    In this work, the electrochemical oxidation of synthetic urine by anodic oxidation using boron-doped diamond as anode and stainless steel as cathode was investigated. Results show that complete depletion of chemical oxygen demand (COD) and total organic carbon (TOC) can be attained regardless of the current density applied in the range 20-100 mA cm(-2). Oxalic and oxamic acids, and, in lower concentrations, creatol and guanidine were identified as the main intermediates. Chloride ions play a very important role as mediators and contribute not only to obtain a high efficiency in the removal of the organics but also to obtain an efficient removal of nitrogen by the transformation of the various raw nitrogen species into gaseous nitrogen through chloramine formation. The main drawback of the technology is the formation of chlorates and perchlorates as final chlorine products. The increase of current density from 20 to 60 mA cm(-2) led to an increase in the rate of COD and TOC removals although the process becomes less efficient in terms of energy consumption (removals of COD and TOC after applying 18 Ah dm(-3) were 93.94 and 94.94 %, respectively, at 20 mA cm(-2) and 89.17 and 86.72 %, respectively, at 60 mA cm(-2)). The most efficient conditions are low current densities and high temperature reaching total mineralization at an applied charge as low as 20 kAh m(-3). This result confirmed that the electrolysis using diamond anodes is a very interesting technology for the treatment of urine. PMID:25399531

  16. Pharmacokinetics of Pegylated recombinant new human Interleukin-6 (PET-rhIL-6)

    International Nuclear Information System (INIS)

    In this study, the newly developed Pegylated recombinant human Interleukin-6 (PEG-rhIL-6) was investigated. With 125I labeled PEG-rhIL-6 by two-phase chloramine-T method. Thirty of the SD rats were randomly divided into 6 groups (group 1, 2, 3, 4, 5 and 6, respectively), with 5 animals (3 males and 2 females) each group. Group 1, 2 and 3 were injected subcutaneously with 125I-PEG-rhIL-6 at the dose of 40, 20 and 3 μg/kg, respectively. Group 4, 5 and 6 were injected intravenously with 125I-PEG-rhIL-6 with the same dose level, respectively. Blood samples were collected at different time intervals after injection. The plasma concentration (ng/ml) of 125I-PEG-rhIL-6 were determined by 125I isotope tracing method and then assessed with 3P87 software to obtain the pharmacokinetic parameters. Results clearly showed that 1/2 ke (20.41, 21.53, 19.77) and tl/2 ka (10.44, 11.26, 11.37) of group 1-3 are higher number than t1/2β (17.54, 18.78, 17.81) and t1/2α (1.93, 1.60, 1.78) of group 4-6. The pharmacological activity of 125I-PEG-rhIL-6 maintain longer time by subcutaneous injection; The pharmacokinetic of V/Fc after sc (694.96 ml/kg) is higher than those after iv (115.26 ml/kg), which showed that the excretion speed of 125-PEG-rhIL-6 given by sc was slowly. The above results obtained indicated that the pharmacokinetic characteristics of 125I-PEG-rhIL-6 would provide important information for clinical application and the subcutaneous injection is better. (authors)

  17. Electrochemical disinfection of toilet wastewater using wastewater electrolysis cell.

    Science.gov (United States)

    Huang, Xiao; Qu, Yan; Cid, Clément A; Finke, Cody; Hoffmann, Michael R; Lim, Keahying; Jiang, Sunny C

    2016-04-01

    The paucity of proper sanitation facilities has contributed to the spread of waterborne diseases in many developing countries. The primary goal of this study was to demonstrate the feasibility of using a wastewater electrolysis cell (WEC) for toilet wastewater disinfection. The treated wastewater was designed to reuse for toilet flushing and agricultural irrigation. Laboratory-scale electrochemical (EC) disinfection experiments were performed to investigate the disinfection efficiency of the WEC with four seeded microorganisms (Escherichia coli, Enterococcus, recombinant adenovirus serotype 5, and bacteriophage MS2). In addition, the formation of organic disinfection byproducts (DBPs) trihalomethanes (THMs) and haloacetic acids (HAA5) at the end of the EC treatment was also investigated. The results showed that at an applied cell voltage of +4 V, the WEC achieved 5-log10 reductions of all four seeded microorganisms in real toilet wastewater within 60 min. In contrast, chemical chlorination (CC) disinfection using hypochlorite [NaClO] was only effective for the inactivation of bacteria. Due to the rapid formation of chloramines, less than 0.5-log10 reduction of MS2 was observed in toilet wastewater even at the highest [NaClO] dosage (36 mg/L, as Cl2) over a 1 h reaction. Experiments using laboratory model waters showed that free reactive chlorine generated in situ during EC disinfection process was the main disinfectant responsible for the inactivation of microorganisms. However, the production of hydroxyl radicals [OH], and other reactive oxygen species by the active bismuth-doped TiO2 anode were negligible under the same electrolytic conditions. The formation of THMs and HAA5 were found to increase with higher applied cell voltage. Based on the energy consumption estimates, the WEC system can be operated using solar energy stored in a DC battery as the sole power source. PMID:26854604

  18. Occurrence of selected aliphatic amines in source water of major cities in China

    Institute of Scientific and Technical Information of China (English)

    Haifeng Zhang; Shuoyi Ren; Jianwei Yu; Min Yang

    2012-01-01

    The formation of toxic nitrogenous disinfection byproducts (N-DBPs),such as nitrosamines,halonitromethanes and haloacetonitriles,from reactions between chlorine/chloramine and dissolved organic nitrogen in drinking water has caused great concern with regarding public health.This study revealed the occurrence of 17 aliphatic amines,some of which have been confirmed to be the precursors of N-DBPs,in source water across China.A sensitive method based on benzenesulfonyl chloride derivatization and liquid-liquid extraction followed by GC-MS analysis was established for the simultaneous analysis of the selected amines in aqueous samples.In total,37 source water samples from the capital cities of 20 provinces were collected for the survey.Among the 17 amines,14 were detected with an average frequency of detection of 36%.The most relevant amines in terms of frequency and maximum concentrations detected were dimethylamine (100%,24.82 μg/L),methylamine (78%,0.92 μg/L),N-methylethylamine (70%,8.84 μg/L),propylamine (59%,10.69 μg/L),diethylamine (54%,3.76 μg/L),N-methylbutylamine (35%,3.07 μg/L),N-ethylpropylamine (35%,0.52 μg/L),and piperidine (32%,2.35 μg/L).This is the first large scale survey of the aliphatic amines occurrence in source water in the world.The wide presence of nitrosamine precursors like dimethylamine,N-methylethylamine and diethylamine,and the precursors of haloacetonitriles and halonitromethanes like methylamine and propylamine suggests that better source water management is required to ensure the safety of drinking water.

  19. SPECT of Transplanted Islets of Langerhans by Dopamine 2 Receptor Targeting in a Rat Model.

    Science.gov (United States)

    Willekens, Stefanie M A; van der Kroon, Inge; Joosten, Lieke; Frielink, Cathelijne; Boerman, Otto C; van den Broek, Sebastiaan A M W; Brom, Maarten; Gotthardt, Martin

    2016-01-01

    Pancreatic islet transplantation can be a more permanent treatment for type 1 diabetes compared to daily insulin administration. Quantitative and longitudinal noninvasive imaging of viable transplanted islets might help to further improve this novel therapy. Since islets express dopamine 2 (D2) receptors, they could be visualized by targeting this receptor. Therefore, the D2 receptor antagonist based tracer [(125/123)I][IBZM] was selected to visualize transplanted islets in a rat model. BZM was radioiodinated, and the labeling was optimized for position 3 of the aromatic ring. [(125)I]-3-IBZM was characterized in vitro using INS-1 cells and isolated islets. Subsequently, 1,000 islets were transplanted in the calf muscle of WAG/Rij rats and SPECT/CT images were acquired 6 weeks after transplantation. Finally, the graft containing muscle was dissected and analyzed immunohistochemically. Oxidative radioiodination resulted in 3 IBZM isomers with different receptor affinities. The use of 0.6 mg/mL chloramine-T hydrate resulted in high yield formation of predominantly [(125)I]-3-IBZM, the isomer harboring the highest receptor affinity. The tracer showed D2 receptor mediated binding to isolated islets in vitro. The transplant could be visualized by SPECT 6 weeks after transplantation. The transplants could be localized in the calf muscle and showed insulin and glucagon expression, indicating targeting of viable and functional islets in the transplant. Radioiodination was optimized to produce high yields of [(125)I]-3-IBZM, the isomer showing optimal D2R binding. Furthermore, [(123)I]IBZM specifically targets the D2 receptors on transplanted islets. In conclusion, this tracer shows potential for noninvasive in vivo detection of islets grafted in the muscle by D2 receptor targeting. PMID:26607139

  20. Development of simple immunoradiometric assays using avidin coupled to polystyrene beads as a common solid phase

    International Nuclear Information System (INIS)

    In this paper, we describe the preparation and application of avidin coupled polystyrene beads as a common solid phase for use in immunoradiometric assays (IRMAs). The assay system is based on two matched commercial monoclonal antibodies, of which, the capture antibody is biotinylated using biotinamidocaproate N-hydroxysuccinimide ester and the detection antibody is radiolabeled with 125I by conventional Chloramine-T method. Avidin was immobilized on the polystyrene beads through a primary coat of bovine serum albumin using glutaraldhyde activation method. Various factors, such as concentration of reagents, incubation time, etc. were optimised to obtain a simple assay protocol consisting of only two pipetting steps, namely, that of a mixture of the two labelled antibodies (radiolabelled and biotinylated) and of the standard or sample. The advantage of the Avidin-Biotin system is the improved sensitivity, economy of antibody and the possibility to use a common solid phase in assays for different analytes. Using the polystyrene beads along with the novel decanting device, it has been possible to achieve the convenience of the 'coated-tube' technology without the expensive automation necessary for large scale preparation of antibody coated tubes. This protocol has been successfully applied to Prolactin, LH and FSH assays. The sensitivity of the Prolactin assay is 8μIU/mL (0.3 ng/mL), that of the FSH assay is 1mIU/mL and that of the LH assay is 0.9 mIU/mL. The intra-assay and inter-assay variations were <10%. Shelf life of the avidin coupled beads was found to be about 8 months and that of the biotin labelled antibodies up to 18 months. (author)

  1. Radioimmunoassay of drugs: Phenytoin, clonidine and theophylline

    International Nuclear Information System (INIS)

    The development of radioimmunoassay procedures using 125I labelled tracers, for the drugs phenytoin, clonidine and theophylline is described. These drugs are conjugated to tyrosine methyl ester (TME) and bovine serum albumin (BSA) after suitable chemical modification, for preparation of radioiodinated drugs and antisera respectively. Phenytoin was modified to phenytoin valeric acid (P-VA) and phenytoin acetic acid (p-AA). In the case of clonidine, 4 carboxy clonidine (4-CLD) was used as the starting material, while for theophylline, 7-propionic acid (7-PAT) and 8-butyric acid (8-BAT) derivatives were made. Phenytoin and clonidine derivatives were coupled to BSA by the carbodiimide method. Theophylline derivatives were coupled to BSA by the mixed anhydride method. The drug-BSA conjugates were purified by dialysis and emulsified in complete Freund's adjuvant for immunization in rabbits. The different drug derivatives were coupled to TME using carbodiimide. The conjugates were purified by thin layer chromatography (TLC). Iodine-125 labelled tracers were prepared from the drug-TME derivatives using the chloramine-T method and purified by TLC or gel filtration. In phenytoin and theophylline good separation was obtained with TLC, while in clonidine, gel filtration was found to be better. Dextran coated charcoal was used as the separation system for clonidine, while polyethylene glycol was used for phenytoin and theophylline. Various factors such as time, temperature, concentration of reagents, serum interference and separation system were optimized to arrive at a suitable assay system for each of the drugs. The optimized assay systems were validated by precision profiles, interassay and intra-assay variations and specificity studies. These optimized systems have adequate sensitivity and can be used for the measurement of the drugs in serum without prior extraction of the samples. (author). 18 refs, 3 figs, 4 tabs

  2. RADIOCHEMICAL STUDIES ON ALPHA FETOPROTEIN RADIOIMMUNOASSAY SOLID PHASE COATED BEADS

    International Nuclear Information System (INIS)

    Alpha fetoprotein (AFP) is a marker for hepatocellular and germ cell carcinoma. There are many different techniques used for measuring AFP in blood where the most accurate one is the immunoassay technique. The aim of the present study was to evaluate, optimize and prepare anti-AFP solid phase coated beads and use it for the determination of AFP in serum. The anti-AFP polyclonal antibodies were prepared by immunization of five rats with a highly purified AFP antigen and the anti-sera obtained were used for coating polystyrene beads to obtain the solid phase coated beads. Also, the AFP antigen was labelled with 125 I using chloramin-T (Ch-T) as oxidizing agent and the tracer obtained was purified using sephadex G-25 (PD-10) chromatography. The assay was performed using a set of AFP standards prepared by diluting the cord blood. The suitable conditions for coating process were obtained which include pH 8, molarity of coating buffer 0.05 M, volume of coating buffer 100 ml and dilution of antibody 1:1000 for coating 1000 beads. Because the coated beads prepared using borate buffer is more suitable than prepared using carbonate or phosphate buffers, they were chosen to complete the optimization and validation study. The optimization and characterization of the assay were performed to evaluate the quality of the proposed system. The system prepared proved a low cost, simple, sensitive and accurate results. The prepared system can be used to evaluate AFP in the blood and this will be helpful in diagnosing some diseases such as hepatocellular carcinoma and neural tube defects

  3. Radioimmunoassay kit formulation and its validation for serum progesterone using progesterone radiotracer purified by gel filtration

    International Nuclear Information System (INIS)

    Purification of the radioiodinated progesterone tyrosine methyl ester conjugate by gel filtration and the development, optimization and clinical validation of a direct radioimmunoassay (RIA) of progesterone using this radiotracer are described. High purity radiotracer is essential for the error free performance of any RIA. Progesterone 11α hemisuccinate was conjugated to tyrosine methyl ester (TME) by the mixed anhydride method and this conjugate was then radioiodinated by the chloramine-T method. Purification of the radioiodinated product was carried out by gel filtration. About 12 batches of the radiotracer were prepared and purified. The purification by gel filtration gave reproducible elution pattern and purity. The radiotracer thus purified was found to have consistent quality as compared to that of any other purification methods. Non-specific binding of the radiotracer was found to be 95% as checked by paper electrophoresis. The stability (retention of the immunoreactivity) of the radiotracer was two to three months. No appreciable changes in the assay characteristics were observed during this period. The assay involved 3 hours incubation of progesterone antibody with individual standards or sample and radiotracer at room temperature. The optimized assay was then validated for internal and external quality control parameters. A RIA kit was then formulated with this radiotracer for estimation of progesterone in serum. The assay kit consisted of lyophilized individual standards ranging from 0.25 to 50 ng/ml. The clinical performance of the developed kit was compared with that of a commercial ELISA kit and a correlation of 0.94 was observed. (author)

  4. Fast determination of cyanide by paper disk method%氰化物纸片快速测定食品中的氰化物

    Institute of Scientific and Technical Information of China (English)

    杨俊; 陈亿展; 孟令兵; 赖小丽; 李意

    2012-01-01

    目的:建立食品中氰化物的纸片速测法并应用于重大活动保障中.方法:食品中的氰化物经水浸取后,与氯胺T反应生成氯化氰,继而与异烟酸反应,并经水解而成戊烯二醛,最后与1,3-二甲基巴比妥酸作用生成紫蓝色化合物,比色定量.结果:方法检出限为1.00 mg/kg,准确度和精密度都较为理想.结论:氰化物纸片速测法具有灵敏度高,快速,携带方便的特点,适合于重大活动保障中氰化物的快速测定.%Objective:To establish a method for fast determination of cyanide in food by paper disk method in important Activities. Methods: Cyanide in food was leached with water,and then reacted with chloramine T to form ey-anochloride which reacted with isonicotinic acid, the product was hydrolyed to glutaconaldehyde, and finally it reacted with 1,3- dimethyl barbituric acid to form a violet blue compound. The content of cyanide was quantitated colorime-trically. Results: The detection limit of the method was 1. 00 mg/kg, the recoveries and the precision were satisfactory. Conclusion: The method was sensitive, fast and convenient. It is suitable to determine cyanide in food in important Activities.

  5. Preparation of mono-radioiodinated tracers for study of the in vivo metabolism of atrial natriuretic peptide in humans

    International Nuclear Information System (INIS)

    The authors evaluate the optimum chemical conditions for labelling atrial natriuretic peptide (ANP) and its metabolites and for preparing highly purified radiotracers which can be used for in vivo kinetic studies of ANP in humans. Synthetic α h1-28ANP and some hormone metabolites were iodinated with Na125I or Na131I by means of the lactoperoxidase (ANP) or the chloramine-T (ANP metabolites) technique. The biological activity of labelled ANP was tested by means of a binding study using mouse cardiac membranes. A high-performance liquid chromatography (HPLC) procedure was used to purify the labelled hormone and the principal labelled metabolites in venous plasma samples collected up to 50 min after the injection of 125I-labelled ANP from nine healthy men. The main ANP kinetic parameters were derived from the disappearance curves of the [125I]ANP, which were satisfactorily fitted by a bi-exponential function in all subjects. The main advantages of this tracer technique are high accuracy, allowing the identification of the metabolites produced in vivo under steady-state conditions after injection of the precursor (labelled hormone) high sensitivity, allowing the detection of minimal quantities of metabolites high specificity, allowing the detection of possible in vitro artefactual generation of cleavage products of ANP using an internal labelled standard. Utilizing this tracer method, it was possible to estimate the principal parameters of ANP kinetics and also to plot the appearance curves of the labelled metabolites produced in vivo after the injection of the labelled precursor. (orig.). With 5 figs

  6. Problems in the application of labelled antibody techniques to communicable and parasitic diseases

    International Nuclear Information System (INIS)

    Two-site immunoradiometric and universal reagent techniques, using radiolabelled antibody, may be applied to communicable diseases. Labelled antibody techniques avoid the problems of purifying and then atraumatically radioiodinating the microorganismal antigens for radioimmunoassay. The application of solid-phase radiolabelled techniques to detect antigenaemia and circulating antibodies in mycobacterial diseases and amoebiasis caused by Mycobacterium tuberculosis and Entamoeba histolytica is described. Methods of antibody radioiodination (Chloramine-T, lactoperoxidase and iodogen) are compared, as well as the relative efficacy of labelling immunoglobulin sodium sulphate precipitate fractions vis-a-vis antibodies purified by affinity chromatography on antigen linked to immunoadsorbents (CNBr Sepharose 4B, diazocellulose). The problems of non-specific reactions because of interglobulin reactions or sticky IgM antibodies adhering to plastic solid phases are emphasized. Serious problems may arise if the antisera employed for labelling have themselves been raised against immunogens with complete Freund' s adjuvant because of anti-mycobacterial antibodies. A non-specific reaction in a communicable disease/infestation may represent a low level of exposure and a low level specific reaction, and the problem of obtaining non-infected non-exposed controls arises. Even neonatal blood may contain material IgG antibodies. Various methods of minimizing non-specific interglobulin reactions are stressed to obtain optimal sensitivity, as well as the need for 'matching' the specific antiserum and the universal reagent. Reference is made to the use of monoclonal antibodies derived from in vitro hybridomas in overcoming some of the problems at present limiting the labelled antibody techniques

  7. Prolactin-binding components in rabbit mammary gland: characterization by partial purification and affinity labeling

    International Nuclear Information System (INIS)

    The molecular characteristics of the PRL receptor isolated from rabbit mammary gland microsomes were investigated. Two approaches were employed: 1) affinity purification of PRL receptors and direct electrophoretic analysis, and 2) affinity cross-linking of microsomal receptors with [125I]ovine PRL [(125I]oPRL). PRL receptors were solubilized from mammary microsomes with 3-[(3-cholamidopropyl)dimethylammonio]1-propane sulfonate and purified using an oPRL agarose affinity column. Sodium dodecylsulfate-polyacrylamide gel electrophoresis and silver staining of the gel revealed at least nine bands, including a 32,000 mol wt band which was most intensively labeled with 125I using the chloramine-T method. Covalent labeling of PRL receptors with [125I]oPRL was performed using N-hydroxysuccinimidyl-4-azido benzoate, disuccinimidyl suberate, or ethylene glycol bis (succinimidyl succinate). A single band of 59,000 mol wt was produced by all three cross-linkers when sodium dodecylsulfate-polyacrylamide gel electrophoresis was performed under reducing conditions. Assuming 1:1 binding of hormone and binding subunit and by subtracting the mol wt of [125I]oPRL, which was estimated from the migration distance on the gel, the mol wt of the binding subunit was calculated as 32,000. In the absence of dithiothreitol during electrophoresis, only one major hormone-receptor complex band was observed. The same mol wt binding components were also detected in microsomal fractions of rabbit kidney, ovary, and adrenal. A slightly higher mol wt binding subunit was observed in rat liver microsomes. Rabbit liver microsomes revealed five [125I]oPRL-binding components, three of which were considered to be those of a GH receptor. Moreover, affinity labeling of detergent-solubilized and affinity purified mammary PRL receptors showed a similar major binding subunit

  8. Eradication of colon cancer cells before tumour formation in the peritoneal cavity of mice treated with intraperitoneal Re-186 radioimmunotherapy

    International Nuclear Information System (INIS)

    A treatment adjuvant to surgical resection of the primary lesion has been proven to be beneficial in improving the prognosis of patients with high risks of peritoneal dissemination of colon cancer. This study was performed to determine the comparative efficacy of intraperitoneal radioimmunotherapy (RIT) using Re-186 or I-131 labeled murine antibodies in the extermination of cancer cells. A murine anti-colorectal IgG1, A7 monoclonal antibody, was radio-labeled either with I-131 (by the chloramine-T method) or Re-186 (by the MAG3 pre-chelated method). A total number of 16 mice were subjected to RIT with Re-186 A7 (N=8) or I-131 A7 (N=8) at equitoxic doses in Balb/c bu/nu mice 10 min after intraperitoneal injection of LS180 human colon cancer cells. A third group of mice were subjected to chemotherapy with 5-fluorouracil at 30 mg/kg for 4 consecutive days following the intraperitoneal injection of the same LS180 human colon cancer cells. There were 19 mice in the control group who were not subjected to any form of therapy. The results revealed that the mean survival of mice in the control (N-19), I-131 A7 RIT (N=8) and Chemotherapy (N=6) groups were 33.8 ± 1.0, 80.1 ± 2.5 and 49.3 ± 5.3 days respectively. The eight mice who were subjected to Re-186 A7 RIT showed much better survival compared to the other groups. Two of the eight mice from this group died at 105 and 111 days following Re-186 A7 RIT. Other six mice were sacrificed at 172 days, and autopsy revealed no macroscopic peritoneal tumor growth. Based on this pilot study we concluded that individual tumor cells in the peritoneal cavity would be effectively exterminated by intraperitoneal RIT with Re-186 A7. (author)

  9. DRINKING WATER DISINFECTION BYPRODUCTS:CHEMICAL CHARACTERIZATION AND TOXICITY%饮用水消毒副产物:化学特征与毒性

    Institute of Scientific and Technical Information of China (English)

    赵玉丽; 李杏放

    2011-01-01

    Disinfection of drinking water is essential to and effective for the prevention of water-borne diseases.While achieving deactivation of microbial pathogens to minimize the acute risk, an unintentional consequence is the formation of disinfection byproducts (DBPs) resulting from reactions of disinfectants with natural organic materials (NOMs) in water. Epidemiological studies show potential associations of increased risk of bladder cancer and adverse health effects with DBPs. Balancing microbial risk with chemical risk is challenging for public health protection. Currently, the most commonly used disinfectants are chlorine, chlorine dioxide,chloramines and ozone. Here we provide an overview of chemical characterization, toxicity and analytical methods of 10 classes of DBPs, including trihalomethanes ( THMs), haloacefic acids ( HAAs), bromate ( BrO3- ), chlorite ( ClO2- ), haloacetonitriles (HANs), mutagen X (MX), halonitromethane ( HNMs), iodo acids (IAs), N-nitrosodimethylamines (NMs) and halobenzoquinones (HBQs). We will discuss the challenges and opportunities in the research of DBPs and health effects.%饮用水消毒过程中消毒剂与天然有机物(NOMs)反应生成消毒副产物(DBPs).本文针对氯、氯胺、二氧化氯、臭氧4种主要消毒方式产生的消毒副产物,综述了10类DBPs的化学特性、毒性和分析方法.具体包括:三卤甲烷(THMs)、卤乙酸(HAAs)、溴酸盐(BrO3-)、亚氯酸盐(CIO2-)、卤乙腈(HANs)、致诱变化合物(MX)、卤代硝基甲烷(HNMs)、碘代酸(Ias)、亚硝胺(NMs)以及卤代对苯醌(HBQs).

  10. A retrospective study of disease in elasmobranchs.

    Science.gov (United States)

    Garner, M M

    2013-05-01

    This report reviews diseases of 1546 elasmobranchs representing at least 60 species submitted to Northwest ZooPath from 1994 to 2010. Cownose rays (Rhinoptera bonasus) (78), southern rays (Dasyatis americana) (75), dusky smooth-hounds (Mustelus canis) (74), bonnethead sharks (Sphyrna tiburo) (66), and bamboo sharks (Hemiscylliidae) (56) were the most commonly submitted species. Infectious/inflammatory disease was most common (33.5%) followed by nutritional (11.9%, mostly emaciation), traumatic (11.3%), cardiovascular (5.5%, mostly shock), and toxin-associated disease (3.7%). Bacterial infections (518/1546, 15%) included sepsis (136/518, 26%), dermatitis (7%), branchitis (6%), and enteritis (4%). Fungal infections (10/1546, 0.6%) included dermatitis (30%), hepatitis (30%), and branchitis (20%). Viral or suspected viral infections or disease processes (15/1546, 1%) included papillomatosis (47%), herpesvirus (20%), and adenovirus (7%). Parasitic infections (137/1546, 9%) included nematodiasis (36/137, 26%), ciliate infections (23%), trematodiasis (20%), coccidiosis (6%), myxozoanosis (5%), amoebiasis (4%), cestodiasis (1%), and flagellate infections (1%). Inflammation of unknown cause (401/1546, 26%) included enteritis (55/401, 14%), branchitis (9%), encephalitis (9%), and dermatitis (7%). Traumatic diseases (174/1546, 11.3%) included skin trauma (103/174, 60%), stress/maladaptation (9%), and gut trauma (7%). Toxicoses (57/1546, 4%) included toxic gill disease (16/57, 26%), gas bubble disease (19%), fenbendazole (7%), ammonia (7%), chlorine (5%), and chloramine (3%). Species trends included visceral nematodiasis in black-nosed sharks (Carcharhinus acronotus) (55%); sepsis in dusky smooth-hounds (41%), blue-spotted stingrays (36%), southern rays (36%), and wobeggong sharks (Orectolobus spp) (69%); emaciation in bamboo (33%) and bonnethead (32%) sharks and freshwater stingrays (Potamotrygon motoro) (32%); and trauma in bonnethead sharks (30%). PMID:23528944

  11. Radioimmunotherapy in refractory b-cell nonhodgkins lymphoma with I-131-labeled chimeric anti cd-20 c2b8 (I-131 rituximab): preliminary result

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hye Jin; Park, Yeon Hee; Kim, Sung Eun and others [Korea University Medical School, Seoul (Korea, Republic of)

    2005-07-01

    Recently, the native chimeric human-mouse anti CD-20 antibody IDEC-C2B8 (Rituximab) has been widely applied in NHL. This ongoing phase study was to evaluate whether radioimmunotherapy (RIT) with I-131 rituximab is effective in refractory B-cell NHL. Inclusion criteria were as follows: B-cell NHL with relapsed or refractory to primary standard therapy, measurable disease, adequate hematologic, renal, and hepatic function, informed consent. The rituximab (Mabthera, Roach) was radiolabeled with iodine-131(I-131) using a modified chloramine T method with high radiochemical purity (95%) and preservation of immuno-reactivity. All patients received loading doses of unlabeled rituximab (median, 40 mg: range, 20{approx}70 mg) immediately prior to administration of therapeutic dose (51.4{approx}152.2 MBq/kg), and then underwent gamma camera scan. 11 patients were enrolled (4 low-grade B-cell NHL, 7 DLBCL, median age 63 years). Patients had received a median of three prior chemotherapy regimens. The objective response rate was 36.4% (1 CR, 3 PRs). These all responses were observed in low-grade B-cell NHL, except one with DLBCL. Adverse events were primarily hematologic toxicities; the incidence of grade 3/4 neutropenia, thrombocytopenia, and anemia was 27.3%, 45.5%, and 18.2%, respectively. The treatment-related mortality was observed in one patient, who had been previously treated with high-dose chemotherapy plus TBI with autologous stem cell transplantation. RIT with I-131 rituximab seems to be effective tolerable in refractory low-grade B-cell NHL, although modest activity in refractory DLBCL. Further studies to define the efficacy of I-131 rituximab in DLBCL are warranted.

  12. Development of radioimmunoassay for the measurement of leptin in human serum

    International Nuclear Information System (INIS)

    Leptin is a 16 KDa polypeptide hormone encoded by the obese gene (ob) and secreted by adipose tissue. This hormone plays a major role in energy homeostasis and regulation of food intake and body weight. It also affects the metabolic, neuroendocrine, reproductive and haematopoietic systems. In this study, we report the development and validation of a radioimmunoassay for the quantitative measurement of human leptin in serum. Labeling of recombinant human leptin with 125I was best performed by the chloramineT method, specific activities of 2.8-3.3 MBq/μg were obtained. New Zealand white rabbits were immunized with recombinant human leptin and a highly specific polyclonal antibody was obtained without measurable cross-reaction as analysed using 10 different antigens. Concentrations of human leptin from serum samples were measured by a single overnight incubation assay with a sensitivity of 0.5 ng/mL and a measuring range of 0.5-100 ng/mL. Separation of bound and free fractions was performed with a magnetizable immunosorbent suspension and in the liquid phase assay separation was performed by using a 1mL mixture of anti-rabbit IgG (second antibody raised in sheep) and 8% PEG-solution after 20 minutes incubation at room temperature. Intra-assay and inter-assay imprecision (coefficient of variation) was < 6% and 8%, respectively. Recoveries of leptin in four human serum specimens serially diluted ranged from 88% to 106%. It was concluded that serum human leptin concentrations can be accurately and precisely measured by this novel radioimmunoassay procedure. Preliminary results obtained from the measurement of serum leptin in lean, overweight and obese patients are presented. Serum leptin concentrations correlated with Body Mass Index (BMI) and were significantly higher in women than in men. Such good correlation helped in the follow-up of the treated obese patients. (author)

  13. Preparation of monoclonal antibodies against cardiac myosin and some radiolabelling studies

    International Nuclear Information System (INIS)

    Monoclonal antibodies were raised against myosin, a specific indicator of myocardial infarction and labelled with 125I and 99mTc. Human cardiac myosin was isolated from normal human heart and was used for raising the monoclonal antibodies by the hybridoma technique. Antibody producing clones were identified by ELISA and cloning was done by the limiting dilution technique. Of the 13 clones obtained, 4 were deemed suitable for further studies. The antibodies were grown in ascites, purified, isotyped and their cross reactions with other forms of myosin were estimated. All the clones showed negligible cross reaction with rabbit myosin, but reacted to different extents with bovine skeletal myosin. The most avid antibody Mab-4G4 was chosen for further labelling studies. Mab-4G4 was labelled with 125I using different oxidising agents such as iodogen, chloramine-T and lactoperoxidase. Purified radioiodinated antibody with radiochemical purity >95% could be obtained by gel filtration. Immunoreactivity was retained as tested by binding to myosin immobilised on a solid support. Mab-4G4 was also labelled with 99mTc using stannous tartrate as the reducing agent. Radiolabelling yield was ∼60%, the purity was >95% and the immunoreactivity was retained. Both the labelled preparations were tested for bio-distribution in normal and infarcted rats. The activity accumulation in the infarcted region was ∼ 1.5 and 3.5 times as that in normal heart muscle for 125I and 99mTc labelled Mab-4G4 respectively. The major problem with the iodinated antibody was the in vivo deiodination resulting in very high percentage of activity in the thyroid. Although the fraction of the total activity associated with the infarcted heart is not very impressive, the fact that the activities with the infarcted and normal hearths are significantly different is heartening. With further optimisation of labelling and use of F(ab)'2 fragments, better delineation of the infarct sites is aspired. (author)

  14. Removal of organic contaminants from secondary effluent by anodic oxidation with a boron-doped diamond anode as tertiary treatment

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Segura, Sergi, E-mail: sergigarcia@ub.edu [Advanced Water Management Centre, The University of Queensland, Level 4, Gehrmann Bld. (60), St Lucia, QLD 072 (Australia); Laboratori d’Electroquímica dels Materials i del Medi Ambient, Departament de Química Física, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona (Spain); Keller, Jürg [Advanced Water Management Centre, The University of Queensland, Level 4, Gehrmann Bld. (60), St Lucia, QLD 072 (Australia); Brillas, Enric [Laboratori d’Electroquímica dels Materials i del Medi Ambient, Departament de Química Física, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona (Spain); Radjenovic, Jelena, E-mail: j.radjenovic@awmc.uq.edu.au [Advanced Water Management Centre, The University of Queensland, Level 4, Gehrmann Bld. (60), St Lucia, QLD 072 (Australia)

    2015-02-11

    Graphical abstract: - Highlights: • Mineralization of secondary effluent by anodic oxidation with BDD anode. • Complete removal of 29 pharmaceuticals and pesticides at trace level concentrations. • Organochlorine and organobromine byproducts were formed at low μM concentrations. • Chlorine species evolution assessed to evaluate the anodic oxidation applicability. - Abstract: Electrochemical advanced oxidation processes (EAOPs) have been widely investigated as promising technologies to remove trace organic contaminants from water, but have rarely been used for the treatment of real waste streams. Anodic oxidation with a boron-doped diamond (BDD) anode was applied for the treatment of secondary effluent from a municipal sewage treatment plant containing 29 target pharmaceuticals and pesticides. The effectiveness of the treatment was assessed from the contaminants decay, dissolved organic carbon and chemical oxygen demand removal. The effect of applied current and pH was evaluated. Almost complete mineralization of effluent organic matter and trace contaminants can be obtained by this EAOP primarily due to the action of hydroxyl radicals formed at the BDD surface. The oxidation of Cl{sup −} ions present in the wastewater at the BDD anode gave rise to active chlorine species (Cl{sub 2}/HClO/ClO{sup −}), which are competitive oxidizing agents yielding chloramines and organohalogen byproducts, quantified as adsorbable organic halogen. However, further anodic oxidation of HClO/ClO{sup −} species led to the production of ClO{sub 3}{sup −} and ClO{sub 4}{sup −} ions. The formation of these species hampers the application as a single-stage tertiary treatment, but posterior cathodic reduction of chlorate and perchlorate species may reduce the risks associated to their presence in the environment.

  15. Therapeutic efficacy of intralesional 131I-labelled hyaluronectin in grafted human glioblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Girard, N.; Courel, M.N.; Vera, P.; Delpech, B. [Centre Henri-Becquerel, Rouen (France). Laboratoire d' Oncologie Moleculaire

    2000-07-01

    The grafted human glioblastoma cell CB109 was used as a model for intralesional therapy with 131I-labelled hyaluronectin glycoprotein (131I-HN). 131I-HN bound specifically to in situ hyaluronic acid (HA), a main component of the extracellular matrix which is involved in tumour invasion. Labelling experimental conditions were determined and, finally, 25 {mu}Ci/{mu}gHN, 1 {mu}g chloramine-T/{mu}gHN and a 60-s stirring period provided a 131I-HN preparation with an optimal affinity for HA (64% compared to unlabelled HN). Following intratumoral injection, 131I-HN was retained with a limited diffusion outside the tumour. On day 4 the radioactivity concentrated in the tumour was still 25 times greater than that in the liver, spleen and kidneys combined. For therapeutic assays, 65 {mu}Ci 131I-HN was injected into the tumour, resulting in a delivery of 6.8 Gy over a 7-day period. Controls received unlabelled HN, heat-inactivated HN, a mixture of inactivated HN plus free 131I or no treatment (six animals per group). Tumour volumes were evaluated every second day from treatment day and the rate of tumour growth was expressed as a ratio of tumour size at time intervals to the tumour size at the time of injection. Growth curves were compared: heat-inactivated with or without free 131I had no anti-tumour effect. Unlabelled HN-injected tumours had a slightly slower growth rate than untreated tumours (p < 0.02) and growth rate of 131I-HN-injected tumours was much lower (p < 0.00002). A pronounced inhibitory effect with intralesional 131I-labelled HN injection resulted from a combination of a) blockage of HA, a proliferation facilitating factor, and b) local irradiation of tumoral tissue, while uptake in normal tissues was minimized.

  16. Harvard--MIT research program in short-lived radiopharmaceuticals

    International Nuclear Information System (INIS)

    This report describes progress on five projects. The first project showed a 1000 fold concentration of the cationic complex 99mTc (MIBI) in heart cell mitochondria vs heart cell cytoplasm, as determined by high resolution electron probe microanalysis. Additional technetium-99m based complexes are being developed and tested. The second project involves evaluating technetium acetylacteonates as potential indicators of cerebral blood flow. An intermediate in the synthesis of a technetium porphyrin complex has been synthesized; an oxotechnetium(V)-2,4-pentanedione complex has been prepared and is currently being characterized. The third project involves using radio labelled antibodies for diagnosis and treatment of cancer. An early discovery was that chloramine-T based iodination protocols resulted in a reversal of the charge on mouse lgGs. Immunoperoxidase-labelled monoclonal antibody MOv 18 was shown to bind specifically to the most frequent ovarian aderon carcinomas, and not to healthy tissue, making this antibody a good candidate for immunotherapy or immunodetection. Work on a specific immunotherapy protocol suffered a setback when one reagent, a 125I-biotin complex, proved to be unstable in vivo. The fourth project involves labelling antibodies with positron emitting radionuclides. Radiofluorination was accomplished through reductive alkylation of 18F-aldehyde, or pentafluorophenyl esters. Radioiodination was accomplished using alkyl-tin derivation exchange. The fifth project examined antibody modification for use in radioimmune imaging. Technetium-99m-labelled lgG was shown to be biologically equivalent to Indium-III-labelled lgG for imaging focal sites of inflamation. Also, Indium III labelling of small bioactive peptides was examined as a means of imaging important physiological processes. 44 refs., 2 figs

  17. Health effects of disinfection by-products in chlorinated swimming pools.

    Science.gov (United States)

    Florentin, Arnaud; Hautemanière, Alexis; Hartemann, Philippe

    2011-11-01

    Increased attendance at swimming pools is correlated with higher input of organic and minerals pollutants introduced by swimmers in the swimming pool water. In most swimming pools, microbiological control is performed by disinfection with the addition of chlorine. Chlorine is now well-known to lead to the formation of many disinfection by-products (DBPs) including trihalomethanes and chloramines. The hypothesis of a link between the presence of eye and skin irritation syndromes in swimmers and contact with swimming pool water treated with chlorine was initially proposed by Mood (1953). During recent decades many epidemiological studies have described the importance of DBPs generated with natural or imported organic matter present in water. Many of these DBPs are suspected to be toxic or even carcinogenic. Trihalomethanes and haloacetic acid families are the most studied but others DBPs, like chloral hydrate, haloacetonitriles, N-nitrosodimethylamine and the bromate ion, are emerging compounds of interest. Epidemiological data about the risk of cancer are still controversial. However, numerous publications highlight a toxic risk especially the risk of allergy and respiratory symptoms for babies and elite swimmers. The few publications dedicated to risk assessment do not suggest increased risk, other than for elite swimmers. These publications are likely to underestimate the risk associated with DBPs because of the lack of data in the literature precludes the calculation of risk associated with certain compounds or certain pathways. Thus for regulations, the need to take into account the risks associated with disinfection by-products is now important without forgetting the need of the control of microbiological hazards in swimming pools. PMID:21885333

  18. Links between operating experience feedback of industrial accidents and nuclear safety

    International Nuclear Information System (INIS)

    Since 1992, the bureau for analysis of industrial risks and pollutions (BARPI) collects, analyzes and publishes information on industrial accidents. The ARIA database lists over 40.000 accidents or incidents, most of which occurred in French classified facilities (ICPE). Events occurring in nuclear facilities are rarely reported in ARIA because they are reported in other databases. This paper describes the process of selection, characterization and review of these accidents, as well as the following consultation with industry trade groups. It is essential to publicize widely the lessons learned from analyzing industrial accidents. To this end, a web site (www.aria.developpement-durable.gouv.fr) gives free access to the accidents summaries, detailed sheets, studies, etc. to professionals and the general public. In addition, the accidents descriptions and characteristics serve as inputs to new regulation projects or risk analyses. Finally, the question of the links between operating experience feedback of industrial accidents and nuclear safety is explored: if the rigorous and well-documented methods of experience feedback in the nuclear field certainly set an example for other activities, nuclear safety can also benefit from inputs coming from the vast diversity of accidents arisen into industrial facilities because of common grounds. Among these common grounds we can find: -) the fuel cycle facilities use many chemicals and chemical processes that are also used by chemical industries; -) the problems resulting from the ageing of equipment affect both heavy and nuclear industries; -) the risk of hydrogen explosion; -) the risk of ammonia, ammonia is a gas used by nuclear power plants as an ingredient in the onsite production of mono-chloramine and ammonia is involved in numerous accidents in the industry: at least 900 entries can be found in the ARIA database. The paper is followed by the slides of the presentation

  19. Radioimmunoassay for human myoglobin: methods and results in patients with skeletal muscle or myocardial disorders

    International Nuclear Information System (INIS)

    A sensitive and specific radioimmunoassay has been developed for the measurement of serum Mb. Immunization of rabbit with human Mb yielded anti-Mb antibody which was purified by affinity chromatography. Human hemoglobin, CK, and the component of serum per se did not appear to cross-react with the antibody. Mb was radiolabeled by the chloramine T method. The radioimmunoassay method could detect as little as 0.3 ng of Mb and was not affected by hemolysis. Information is also given on precision, recovery, and specimen preservation. Mb levels could be detected in all of 120 normal adults, and the values ranged between 1 and 28 ng/ml (mean, 13.1 +- 6.1). No sex difference was observed. Levels were markedly elevated in all the patients with progressive muscular dystrophy, especially in the Duchenne type at the level of 40 to 1700 ng/ml. It was also noticed that about 70% of female gene carriers of Duchenne type had a slightly increased Mb level. An elevated serum Mb was also noted in polymyositis. In every case of acute myocardial infarction, serum Mb levels were increased, peak values ranging from 175 to 4400 ng/ml and averaging 1162 +- 287.9 Mb levels were elevated faster and peaked earlier (within 6 to 12 hr after the attack) than serum CK activity and returned to nearly normal range within 3 to 4 days. The increase in serum Mb was also noticed in shock and surgery. These data indicate that radioimmunoassay of Mb is a useful test for judging the myolytic state of myogenic myopathies and for early detection of myocardial infarction

  20. Removal of organic contaminants from secondary effluent by anodic oxidation with a boron-doped diamond anode as tertiary treatment

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Mineralization of secondary effluent by anodic oxidation with BDD anode. • Complete removal of 29 pharmaceuticals and pesticides at trace level concentrations. • Organochlorine and organobromine byproducts were formed at low μM concentrations. • Chlorine species evolution assessed to evaluate the anodic oxidation applicability. - Abstract: Electrochemical advanced oxidation processes (EAOPs) have been widely investigated as promising technologies to remove trace organic contaminants from water, but have rarely been used for the treatment of real waste streams. Anodic oxidation with a boron-doped diamond (BDD) anode was applied for the treatment of secondary effluent from a municipal sewage treatment plant containing 29 target pharmaceuticals and pesticides. The effectiveness of the treatment was assessed from the contaminants decay, dissolved organic carbon and chemical oxygen demand removal. The effect of applied current and pH was evaluated. Almost complete mineralization of effluent organic matter and trace contaminants can be obtained by this EAOP primarily due to the action of hydroxyl radicals formed at the BDD surface. The oxidation of Cl− ions present in the wastewater at the BDD anode gave rise to active chlorine species (Cl2/HClO/ClO−), which are competitive oxidizing agents yielding chloramines and organohalogen byproducts, quantified as adsorbable organic halogen. However, further anodic oxidation of HClO/ClO− species led to the production of ClO3− and ClO4− ions. The formation of these species hampers the application as a single-stage tertiary treatment, but posterior cathodic reduction of chlorate and perchlorate species may reduce the risks associated to their presence in the environment

  1. Photolytic removal of DBPs by medium pressure UV in swimming pool water

    International Nuclear Information System (INIS)

    Medium pressure UV is used for controlling the concentration of combined chlorine (chloramines) in many public swimming pools. Little is known about the fate of other disinfection by-products (DBPs) in UV treatment. Photolysis by medium pressure UV treatment was investigated for 12 DBPs reported to be found in swimming pool water: chloroform, bromodichloromethane, dibromochloromethane, bromoform, dichloroacetonitrile, bromochloroacetonitrile, dibromoacetronitrile, trichloroacetonitrile, trichloronitromethane, dichloropropanone, trichloropropanone, and chloral hydrate. First order photolysis constants ranged 26-fold from 0.020 min−1 for chloroform to 0.523 min−1 for trichloronitromethane. The rate constants generally increased with bromine substitution. Using the UV removal of combined chlorine as an actinometer, the rate constants were recalculated to actual treatment doses of UV applied in a swimming pool. In an investigated public pool the UV dose was equivalent to an applied electrical energy of 1.34 kWh m−3 d−1 and the UV dose required to removed 90% of trichloronitromethane was 0.4 kWh m−3 d−1, while 2.6 kWh m−3 d−1 was required for chloral hydrate and the bromine containing haloacetonitriles and trihalomethanes ranged from 0.6 to 3.1 kWh m−3 d−1. It was predicted thus that a beneficial side-effect of applying UV for removing combined chlorine from the pool water could be a significant removal of trichloronitromethane, chloral hydrate and the bromine containing haloacetonitriles and trihalomethanes. - Highlights: ► UV irradiation is able to degrade all 12 investigated disinfection by-products. ► Bromine species are easier to remove than their chlorinated analogues. ► UV dose used for combined chlorine was comparable with doses required for DBP removal. ► Significant removal of some disinfection by-products in swimming pools is indicated

  2. Determination of 14 haloketones in treated water using solid-phase microextraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Serrano, Maria; Silva, Manuel; Gallego, Mercedes

    2015-08-14

    Haloketones (HKs) are unregulated volatile disinfection by-products that show some potential risk even at low concentrations. While EPA Method 551.1 involves conventional liquid-liquid extraction and a complex series of steps, the simple scientific principles of solid-phase microextraction (SPME) in the headspace (HS) mode can be applied to ensure a solvent-free method to control these substances at appropriate levels. The 14 HKs (12 mL of water at pH∼1.5) were extracted on a DVB/CAR/PDMS fibre in 15min. After extraction, the analytes were desorbed at 250 °C in the GC-MS inlet. Parameters affecting the extraction/desorption steps were investigated to select the most favourable conditions in short times. The HS-SPME/GC-MS method demonstrated high extraction efficiency with low limits of detection of between 15 and 600 ng/L, good linearity in the range 0.05-2 μg/L to 100-2000 μg/L, and good repeatability (RSD below 7%, n=11). The green method was validated with EPA 551.1, used for determining halogenated VOCs in water, with noticeable advantages in terms of sensitivity, simplicity and solvent consumption. The results obtained from the analysis of water taken from a treatment plant employing chlorine dioxide and chloramines as disinfectants showed that two HKs were formed after pre-oxidation and that the subsequent steps in the plant were ineffective for their removal. Finally, the analysis of tap and swimming pool water exhibited that the concentration and number of species formed is higher in the latter, which is in accordance with its higher concentration of residual chlorine and organic matter. PMID:26163928

  3. Assessment of thrombus imaging potency of thrombin-targeting recombinant hirudin in vitro and in vivo

    International Nuclear Information System (INIS)

    The purpose of this study is to evaluate the effect of recombinant hirudin HV2 (rHHV2) as a thrombus imaging agent. 125I-rHHV2 and 125I-Th were prepared with Chloramine method, the labeling rate were 86.64% and 62.20%, with the radioactive purity of 89.70% and 91.22%, with the specific activity of 22.4 TBq/mmol and 94.43 TBq/mmol respectively. The competitive radioassay showed that the Th-fibrin complex formation did not affect the ability of rHHV2 binding with Th. In the complex, the molecular binding ratio of rHHV2 to Th and fibrinogen was 14:14:1. 99mTc-rHHV2 was prepared by 2-iminothiolane modified method, the labeled rate was 94%, with the radioactive purity of 93.90%, with the specific activity of 2.30 TBq/mmol. It was used to image fresh thrombi on arteries and veins of dog or rabbit (30 μg/kg). In SPECT images, all thrombin were clearly visible, arterial thrombosis imaging can be seen clearly within 45 min after injection and fade away slowly, venous thrombosis imaging also can be seen within 30 min after injection and quantitative imaging ratios between the thrombus and opposite vessel increased following the time. Biodistribution studies in mouse demonstrated that rHHV2 was excreted from kidneys. These data indicate that Th in Th-fibrin complex could be a potent target for diagnosis of thrombus and 99mTc-rHHV2 could be a new thrombotic imaging agent. (authors)

  4. Development of radioiodine-labeled 4-hydroxyphenylcysteamine for specific diagnosis of malignant melanoma

    International Nuclear Information System (INIS)

    Introduction: A specific diagnosis for melanoma is strongly desired because malignant melanoma has poor prognosis. In a previous study, although radioiodine-125-labeled 4-hydroxyphenyl-L-cysteine (125I-L-PC) was found to have good substrate affinity for tyrosinase enzyme in the melanin metabolic pathway, 123/131I-L-PC had insufficient substrate affinity for tyrosinase to diagnose melanoma. In this study, we synthesized 4-hydroxyphenylcysteamine (4-PCA) and developed a novel radioiodine-125-labeled 4-hydroxyphenylcysteamine (125I-PCA) to increase affinity for the melanin biosynthesis pathway. Methods: 4-PCA was separated with 2-hydroxyphenylcysteamine (2-PCA), which is an isomer of 4-PCA, and was examined using melting point, proton nuclear magnetic resonance, mass spectrometry and elemental analysis. 125I-PCA was prepared using the chloramine-T method under no-carrier added conditions. We performed biodistribution experiments using B16 melanoma-bearing mice using 125I-PCA, 125I-L-PC, 125I-α-methyl-L-tyrosine, 123I-m-iodobenzylguanidine and 67Ga-citrate. In vitro assay was performed with B16 melanoma cells, and affinity for tyrosinase, DNA polymerase and amino acid transport was evaluated using phenylthiourea, thymidine, ouabine and L-tyrosine inhibitor. In addition, partition coefficients of 125I-PCA were evaluated. Results: In the synthesis of 4-PCA, analysis values did not differ between calculated and reported values, and 4-PCA was separated from 2-PCA at high purity. In biodistribution experiments, 125I-PCA was accumulated and retained in B16 melanoma cells when compared with 125I-L-PC. 125I-PCA showed the highest values at 60 min after radiotracer injection in melanoma-to-muscle ratios, melanoma-to-blood ratios and melanoma-to-skin ratios. Accumulation of 125I-PCA was significantly inhibited by phenylthiourea and thymidine. Partition coefficients of 125I-PCA were lower than those of N-isopropyl-p-[123I]iodoamphetamine and were not significantly different from

  5. Radioimmunoassay of protein C system

    International Nuclear Information System (INIS)

    Protein C system is an anticoagulation pathway which consists of protein C (PC), protein S (PS), thrombomodulator (TM) and protein C inhibitor (PCI). Using the McAb SZ-57, the authors have established SZ-57-Sepharose CL-6B affinity chromatography to purify human urinary TM. A procedure for isolation and purification of PC, PS and PCI from albumin-free human plasma by rivanol precipitation was also established. The isolation steps include adsorption onto and elution from barium, PEG precipitation, ion-exchange chromatography and preparative isoelectric focusing and so on. The molecular weight, isoelectric points, amino acid contents and the functional activity of these proteins were consistent with other previous reports. Four radioimmunoassays (RIAs) of PC, PS, TM and PCI were established using the equilibrium method. 125I-PC and 125I-PS were prepared using the chloramine-T method. 125I-PCI was prepared by iodogen method and 125I-TM by Bolton-Hunter method. Their sensitivities were 3.94 μg/L, 9.87 μg/L, 6.16 μg/L and 2.58 μg/L, respectively. The recovery rates were 104.28%, 94.30%, 105.22% and 101.89. Some antiserum provided a linear response from 6.25 to 1024 μg/L for PC, 21 to 700 μg/L for PS, 8.1 to 560 μg/L for TM and 4.8 to 1024 μg/L for PCI. The intra- and inter-assay CV were 4.4% and 9.68% for PC RIA, respectively, 4.99% and 13.14% for PS RIA, 5.10% and 10.94% for TM RIA, 2.73% and 8.62% for PCI RIA. The cross reactivity with factor II, thrombin, and antithrombin III was negligible. These methods can be used as effective tools especially for diagnosis of thrombosis and basic or clinical studies of protein C system. (20 refs., 8 figs., 6 tabs.)

  6. Structure and composition of arytenoid cartilage of the bullfrog (Lithobates catesbeianus) during maturation and aging.

    Science.gov (United States)

    Laureano, Priscila Eliane dos Santos; Oliveira, Kris Daiana Silva; de Aro, Andrea Aparecida; Gomes, Laurecir; Pimentel, Edson Rosa; Esquisatto, Marcelo Augusto Marretto

    2015-10-01

    The aging process induces progressive and irreversible changes in the structural and functional organization of animals. The objective of this study was to evaluate the effects of aging on the structure and composition of the extracellular matrix of the arytenoid cartilage found in the larynx of male bullfrogs (Lithobates catesbeianus) kept in captivity for commercial purposes. Animals at 7, 180 and 1080 days post-metamorphosis (n=10/age) were euthanized and the cartilage was removed and processed for structural and biochemical analysis. For the structural analyses, cartilage sections were stained with picrosirius, toluidine blue, Weigert's resorcin-fuchsin and Von Kossa stain. The sections were also submitted to immunohistochemistry for detection of collagen types I and II. Other samples were processed for the ultrastructural and cytochemical analysis of proteoglycans. Histological sections were used to chondrocyte count. The number of positive stainings for proteoglycans was quantified by ultrastructural analysis. For quantification and analysis of glycosaminoglycans were used the dimethyl methylene blue and agarose gel electrophoresis methods. The chloramine T method was used for hydroxyproline quantification. At 7 days, basophilia was observed in the pericellular and territorial matrix, which decreased in the latter over the period studied. Collagen fibers were arranged perpendicular to the major axis of the cartilaginous plate and were thicker in older animals. Few calcification areas were observed at the periphery of the cartilage specimens in 1080-day-old animals. Type II collagen was present throughout the stroma at the different ages. Elastic fibers were found in the stroma and perichondrium and increased with age in the two regions. Proteoglycan staining significantly increased from 7 to 180 days and reduced at 1080 days. The amount of total glycosaminoglycans was higher in 180-day-old animals compared to the other ages, with marked presence of

  7. Development of T3 radioimmunoassay kit

    International Nuclear Information System (INIS)

    Thyroxine T4 radioimmunoassay (RIA) kit has already been developed in this laboratory. For an efficient diagnosis of thyroid disease, however, it is well known that the T3 RIA should also be carried out in addition to the T4 RIA. Accordingly, the development of T3 RIA kit was urgently desired to match the T4 kit and to hold a sound domestic supply systems. The high specific activity T3125I about 3,000 μCi/μg T3) could be obtained by radioiodinating T2 with chloramine-T, and the labelled product could be stahilized. In the preparation of T3 free serum, charcoal was eliminated easily from serum by high speed centrifugation, and the resulting T3 free serum was used for the preparation of T3 standard serum solutions. RIA buffer system could be improved with the use of 0.025M barbital buffer, pH 8.2, containing 0.1% BSA, 0.5% bovine aamma globulin and 0.02% merthiolate. Antibody titer was increased threefold by using the 0.025M barbital buffer; the titer was 8,000: 1 in the 0.078M borbital buffer, pH 8.6, containing 0.1% BSA and 0.1% NaN3 while it was 26,000 : 1 in the above described 0.025M barbital buffer. The modified buffer system was also efficient for the use in T4 RIA since it increased the T4 antibody titer twofold. When the same buffer system was used in T3 RIA, no significant difference was observed between the use of HSA and of BSA in so far as 0.5% bovine gamma globulin was added to the buffer, contradicting those in the reference. The resalts indicated that the cost for the preparation of both kits can be saved. Quality guaranteed kits could be prepared by careful control of the assay values in comparing with those of the reference control sera. In consequence, there is not any technical difficulty in routine production. (Author)

  8. Development of anti-CD30 radioimmunoconstructs (RICs) for treatment of Hodgkin's lymphoma. Studies with cell lines and animal studies

    Energy Technology Data Exchange (ETDEWEB)

    Dietlein, M.; Boerner, S.M.; Fischer, T.; Zimmermanns, B.; Kobe, C.; Schicha, H.; Schomaecker, K. [Dept. of Nuclear Medicine, Univ. of Cologne (Germany); Hansen, H.; Schnell, R.; Tawadros, S.; Engert, A.; Staak, O.; Pogge von Strandmann, E. [Dept. of Internal Medicine I, Univ. of Cologne (Germany)

    2010-07-01

    Objectives: comparison of the binding affinity to a CD30-positive Hodgkin lymphoma (HL) cell line and biodistribution in HL bearing mice of new anti-CD30 radioimmunoconjugates (RICs) of varying structure and labelling nuclides. Methods: The antibodies Ki-4 and 5F11 were radioiodinated by the chloramine T method or labelled with {sup 111}In via p-NCS-Benzyl-DOTA. In addition, the Ki-4-dimer was investigated in the iodinated form. The RICs were analyzed for retained immunoreactivity by immunochromatography. In-vitro binding studies were performed on CD30-positive L540 cell lines. For in-vivo biodistribution studies, SCID mice bearing human HL xenografts were injected with the various radio-immunoconjugates. After 24 h, activities in the organs and tumour were measured for all 5 RICs. Tumour-free animals were studied in the same way with {sup 131}I-Ki-4 24 h p. i. The three RICs with the highest tumour/background ratios 24 h p.i. ({sup 131}I-Ki-4, {sup 131}I-5F11, {sup 111}In-bz-DOTA-Ki-4) were analysed further at 48 h and 72 h. Results: all the RICs were successfully labelled with high specific activities (28-47 TBq/mmol) and sufficient radiochemical yields (> 80%). Scatchard plot analysis proved high tumour affinity (K{sub D} = 20-220 nmol/l). In-vivo tumour accumulation in % of injected dose per g tissue (% ID/g) lay between 2.6 ({sup 131}I-5F11) and 12.3 % ID/g ({sup 131}I-Ki-4) with permanently high background in blood. Tumour/blood-ratios of all RICs were below one at all time points. Conclusions: in-vitro tumour cell affinities of all RICs were promising. However, in-vivo biokinetics tested in the mouse model did not meet expectations. This highlights the importance of developing and testing further new anti-CD30 conjugates. (orig.)

  9. New LHRH analogs for the detection of LHRH positive tumors

    International Nuclear Information System (INIS)

    Aim: Receptors for luteinizing hormone-releasing hormone (LHRH) can be found in various tumors including breast cancers as shown by previous studies on human specimens. Recently efforts were undertaken to target these receptors with cytotoxic peptide conjugates in experimental animal models (Schally et al.). However, LHRH receptor imaging in humans has not yet been reported. The aim of this study was to develop suitable analogs for this purpose and test the hypothesis that LHRH receptors can be detected and visualized by scintigraphic methods. Methods: Three radiolabeled analogs were prepared and evaluated in-vitro: Analog A is a radioiodinated derivative of the LHRH agonist D-Trp6-LHRH (Triptorelin). Analog B is a MAG-3 conjugate of D-Lys6-LHRH. (D-Lys6-LHRH is known to allow conjugation without substantial loss of receptor binding properties). Analog C is a HYNIC-conjugate of D-Lys6-LHRH. The latter 2 compounds allow for Tc-99m (and also Re-188) labeling. The iodinated compound was labeled using Chloramine-T methods and the Tc-labeled LHRH analogs were prepared by direct SnCl2 mediated labeling of the conjugates of chelator and peptide. (The conjugates were prepared using NHS-esters of the respective chelators, removal of protecting groups and final HPLC-purification.) High radiochemical yields and high specific activity can be obtained with all three compounds. However, first patient studies were carried out with the best characterized I-123-D-Trp6-LHRH. Results: Four patients (3 female, 1 male; mean age 53 y, 42-59) with newly diagnosed breast cancer underwent LHRH receptor scintigraphy after conventional imaging (US, mammography and MRI). After intravenous injection of 2-4 mCi HPLC-purified I-123-labeled D-Trp6-LHRH dynamic imaging was performed for 20 min with subsequent static imaging including whole body scans. The results were matched with conventional imaging. In 3/4 patients the breast cancer lesion was clearly visualized with tumoral tracer accumulation

  10. Seasonal evaluation of the presence of 46 disinfection by-products throughout a drinking water treatment plant

    International Nuclear Information System (INIS)

    In this work, we studied a total of 46 regulated and non-regulated disinfection by-products (DBPs) including 10 trihalomethanes (THMs), 13 haloacetic acids (HAAs), 6 halonitromethanes (HNMs), 6 haloacetonitriles (HANs) and 11 aldehydes at different points in a drinking water treatment plant (DWTP) and its distribution network. Determining an increased number of compounds and using accurate, sensitive analytical methodologies for new DBPs can be useful to overcome some challenges encountered in the comprehensive assessment of the quality and safety of drinking water. This paper provides a detailed picture of the spatial and seasonal variability of DBP concentrations from raw water to distribution network. Samples were collected on a monthly basis at seven different points in the four seasons of a year to acquire robust data for DBPs and supplementary quality-related water parameters. Only 5 aldehydes and 2 HAAs were found in raw water. Chlorine dioxide caused the formation of 3 new aldehydes (benzaldehyde included), 5 HAAs and chloroform. The concentrations of DBPs present in raw water were up to 6 times higher in the warmer seasons (spring and summer). The sedimentation process further increased their concentrations and caused the formation of three new ones. Sand filtration substantially removed aldehydes and HAAs (15–50%), but increased the levels of THMs, HNMs and HANs by up to 70%. Chloramination raised the levels of 8 aldehydes and 7 HAAs; also, it caused the formation of monoiodoacetic acid, dibromochloromethane, dichloroiodomethane and bromochloroacetonitrile. Therefore, this treatment increases the levels of existing DBPs and leads to the formation of new ones to a greater extent than does chlorine dioxide. Except for 5 aldehydes, the 23 DBPs encountered at the DWTP exit were found at increased concentrations in the warmer seasons (HAAs by about 50% and THMs by 350%). - Highlights: • Occurrence of 46 regulated and non-regulated DBPs through a DWTP was

  11. Development of a new radioimmunoassay for erythropoietin using recombinant erythropoietin

    Energy Technology Data Exchange (ETDEWEB)

    Mason-Garcia, M.; Beckman, B.S.; Brookins, J.W.; Powell, J.S.; Lanham, W.; Blaisdell, S.; Keay, L.; Li, S.C.; Fisher, J.W. (Tulane Univ. School of Medicine, New Orleans, LA (USA))

    1990-11-01

    The development of a 24 hour radioimmunoassay for erythropoietin (EPO) using EPO derived from recombinant DNA as both immunogen and ligand is described in the present paper. Mixed breed rabbits immunized with 10 micrograms/kg of EPO derived from a stably transfected cell line (MD) produced antibodies to EPO with high titer (up to 1:896,000 final dilution in the tube), high affinity (8.4 x 10(11) liter/M), and good specificity. Purified EPO from the above source or from AmGen Biologicals (AG) were successfully radioiodinated with the chloramine-T method and used as ligand in the radioimmunoassay. Standard dose-response curves prepared with EPO from both commercial sources were not significantly different and showed a sensitivity of 0.75 to 0.96 mU/tube. The dose-response curves in both systems also showed parallelism with serially diluted serum from a patient with aplastic anemia. Within-assay and between-assay precision were determined by assaying multiple replicates of a serum pool. Recovery of exogenous EPO added to a serum pool averaged 97% for both systems. The range of normal human serum EPO was determined by assaying the sera of 153 hematologically-normal adult subjects and was found to be 1.1 to 27.3 mU/ml for MD EPO and 0.5 to 16.7 mU/ml for AG EPO. Sera from several patients with hematologic abnormalities were also assayed, including those of 36 patients with anemia of end-stage renal disease (mean +/- SEM, 29.5 +/- 4.0 mU/ml; P less than 0.01). In conclusion, this new, more rapid and sensitive radioimmunoassay system can be used to measure EPO levels in sera from normal human subjects and patients with several types of anemia, and should also be very useful in therapeutic drug monitoring of patients receiving EPO from various commercial sources.

  12. Thrombus detection with a radiolabeled antiplatelet monoclonal antibody: Comparison with In-111-oxine technique in coronary and peripheral thrombi in dogs

    International Nuclear Information System (INIS)

    Platelets (P) labeled with low concentrations of an I-123 or In-111 labeled anti-P monoclonal antibody (7E3) were shown earlier to successfully image in-vivo thrombi. This study was carried out to compare this technique with In-111-oxine-P for localizing coronary and venous thrombi (CT and DVT) in dogs. Thrombi were induced using either transcatheter placement of a dacron pug, mechanical trauma, or electrocoagulation. 7E3 was labeled with I-131 in 70 +- 10% yield (labeling conditions: 100 μg 7E3; 5 μg chloramine T; I/sup -//7E3 ≤1; 2 min reaction; 200 μl pH 7 phosphate buffer; Sp. act. 10-30 μCi/μg). Binding of I-131-7E3 to dog P was 75 +- 10% after 1 hr incubation with whole blood. The dogs were injected with 0.5 mCi In-111-oxine-P and 1 mCi I-131-7E3-P in quick succession and data (blood clearance and imaging) were collected for 4 hr. In one experiment, DVT were clearly imaged within 10 min and CT in 30-60 min with I-131-7E3-P. In contrast, In-oxine-P required at least 30 min for imaging DVT and CT were only faintly visualized at 3-4 hr. The DVT to blood and CT to blood ratios at 2.4 hr were 16 and 12.3 for I-131-7E3-P and 9.4 and 6.5 for In-111-oxine-P respectively. In these preliminary studies, I-131-7E3-P thus appears to be superior to In-oxine-P for imaging venous and coronary thrombi. Additionally, 7E3 can be labeled with Tc-99m and I-123 for reduced dose and better imaging properties

  13. Functional expression of a single-chain antibody to ErbB-2 in plants and cell-free systems

    Directory of Open Access Journals (Sweden)

    Benevolo Maria

    2006-09-01

    Full Text Available Abstract Background Aberrant signaling by ErbB-2 (HER 2, Neu, a member of the human Epidermal Growth Factor (EGF receptor family, is associated with an aggressive clinical behaviour of carcinomas, particularly breast tumors. Antibodies targeting the ErbB-2 pathway are a preferred therapeutic option for patients with advanced breast cancer, but a worldwide deficit in the manufacturing capacities of mammalian cell bioreactors is foreseen. Methods Herein, we describe a multi-platform approach for the production of recombinant Single chain Fragments of antibody variable regions (ScFvs to ErbB-2 that involves their functional expression in (a bacteria, (b transient as well as stable transgenic tobacco plants, and (c a newly developed cell-free transcription-translation system. Results An ScFv (ScFv800E6 was selected by cloning immunoglobulin sequences from murine hybridomas, and was expressed and fully functional in all the expression platforms, thereby representing the first ScFv to ErbB-2 produced in hosts other than bacteria and yeast. ScFv800E6 was optimized with respect to redox synthesis conditions. Different tags were introduced flanking the ScFv800E6 backbone, with and without spacer arms, including a novel Strep II tag that outperforms conventional streptavidin-based detection systems. ScFv800E6 was resistant to standard chemical radiolabeling procedures (i.e. Chloramine T, displayed a binding ability extremely similar to that of the parental monovalent Fab' fragment, as well as a flow cytometry performance and an equilibrium binding affinity (Ka approximately 2 × 108 M-1 only slightly lower than those of the parental bivalent antibody, suggesting that its binding site is conserved as compared to that of the parental antibody molecule. ScFv800E6 was found to be compatible with routine reagents for immunohistochemical staining. Conclusion ScFv800E6 is a useful reagent for in vitro biochemical and immunodiagnostic applications in oncology

  14. A radioimmunoassay for erythropoietin: serum levels in normal human subjects and patients with hemopoietic disorders

    Energy Technology Data Exchange (ETDEWEB)

    Rege, A.B.; Brookins, J.; Fisher, J.W.

    1982-12-01

    An RIA for Ep has been developed that is highly sensitive and specific. A homogeneous Ep preparation was labeled with /sup 125/I by the chloramine-T method to a specific activity of 90 to 136 ..mu..Ci/..mu..g and immunoreactivity of 80%. Ep antiserum, which was produced to a human urinary Ep preparation (80 U/mg of protein), was adsorbed with normal human urinary and serum proteins without any loss in sensitivity of the RIA to increase the specificity of the assay. A good correlation was seen between the RIA and the exhypoxic polycythemic mouse assay (corr. coef. 0.967; slope 1.05 and ''y'' intercept 0.75). Ep titers in sera from 175 hematologically normal human subjects exhibited a normal frequency distribution and ranged between 5.8 and 36.6 mU/ml with a mean of 14.9 +/- 4.7 (S.D.) and median of 14.3. Serum Ep titers were markedly elevated in seven patients with aplastic anemia and one patient with pure red cell aplasia (1350 to 20,640 mU/ml) and were lower than normal in two patients with polycythemia vera (8.1 and 9.4 mU/ml). The serum Ep titers in a prenephrectomy patient with chronic glomerulonephritis (31.1 mU/ml) decreased to below normal levels (9.04 mU/ml) after nephrectomy. The cord serum erythropoietin titers in 10 IDM (90.82 +/- 134.1 (S.D.) mu/ml) returned to values within the normal range (13.86 +/- 5.55) on day 3 after birth, suggesting the utility of the RIA in elucidating the role of hypoxia and/or insulin in increased erythropoiesis in IDM. The serum Ep titers in patients with anemias and polycythemias were compared to those of normal human subjects and agreed well with pathophysiologic mechanisms of these hemopoietic disorders, confirming the validity of the RIA.

  15. A radioimmunoassay for erythropoietin: serum levels in normal human subjects and patients with hemopoietic disorders

    Energy Technology Data Exchange (ETDEWEB)

    Rege, A.B.; Brookins, J.; Fisher, J.W.

    1982-12-01

    An RIA for Ep has been developed that is highly sensitive and specific. A homogeneous Ep preparation was labeled with /sup 125/I by the chloramine-T method to a specific activity of 90 to 136 micro Ci/microgram and immunoreactivity of 80%. Ep antiserum, which was produced to a human urinary Ep preparation (80 U/mg of protein), was adsorbed with normal human urinary and serum proteins without any loss in sensitivity of the RIA to increase the specificity of the assay. A good correlation was seen between the RIA and the exhypoxic polycythemic mouse assay (corr. coef. 0.967; slope 1.05 and y intercept 0.75). Ep titers in sera from 175 hematologically normal human subjects exhibited a normal frequency distribution and ranged between 5.8 and 36.6 mU/ml with a mean of 14.9 +/- 4.7 (S.D.) and median of 14.3 Serum Ep titers were markedly elevated in seven patients with aplastic anemia and one patient with pure red cell aplasia (1350 to 20,640 mU/ml) and were lower than normal in two patients with polycythemia vera (8.1 and 9.4 mU/ml). The serum Ep titers in a prenephrectomy patient with chronic glomerulonephritis (32.1 mU/ml) decreased to below normal levels (9.04 mU/ml) after nephrectomy. The cord serum erythropoietin titers in 10 IDM (90.82 +/- 134.1 (S.D.) mu/ml) returned to values within the normal range (13.86 +/- 5.55) on day 3 after birth, suggesting the utility of the RIA in elucidating the role of hypoxia and/or insulin in increased erythropoiesis in IDM. The serum Ep titers in patients with anemias and polycythemias were compared to those of normal human subjects and agreed well with pathophysiologic mechanisms of these hemopoietic disorders, confirming the validity of the RIA.

  16. EFFECTS OF SODIUM AND CALCIUM IN LIGNITE ON THE PERFORMANCE OF ACTIVATED CARBON PRODUCTS; TOPICAL

    International Nuclear Information System (INIS)

    New federal drinking water regulations have been promulgated to restrict the levels of disinfection by-products (DBPs) in finished public water supplies. DBPs are suspected carcinogens and are formed when organic material is partially oxidized by disinfectants commonly used in the water treatment industry. Additional federal mandates are expected in the near future that will also affect public water suppliers with respect to DBPs. These new federal drinking water regulations may require public water suppliers to adjust treatment practices or incorporate additional treatment operations into their existing treatment trains. Many options have been identified, including membrane processes, granular activated carbon, powered activated carbon (PAC), enhanced coagulation and/or softening, and alternative disinfectants (e.g., chlorine dioxide, ozone, and chloramines). Of the processes being considered, PAC appears to offer an attractive benefit-to-cost advantage for many water treatment plants, particularly small systems (those serving fewer than 10,000 customers). PAC has traditionally been used by the water treatment industry for the removal of compounds contributing to taste and odor problems. PAC also has the potential to remove naturally occurring organic matter (NOM) from raw waters prior to disinfection, thus controlling the formation of regulated DBPs. Many small water systems are currently using PAC for taste and odor control and have the potential to use PAC for controlling DBPs. Activated carbons can be produced from a variety of raw materials, including wood, peat, coconut husks, and numerous types of coal. The Energy and Environmental Research Center (EERC) has been working on the development of a PAC product to remove NOM from surface water supplies to prevent the formation of carcinogenic DBPs during chlorination. During that study, the sodium and calcium content of the lignites showed a significant effect on the sorption capacity of the activated carbon

  17. EFFECTS OF SODIUM AND CALCIUM IN LIGNITE ON THE PERFORMANCE OF ACTIVATED CARBON PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    Edwin S. Olson; Kurt E. Eylands; Daniel J. Stepan

    2001-12-01

    New federal drinking water regulations have been promulgated to restrict the levels of disinfection by-products (DBPs) in finished public water supplies. DBPs are suspected carcinogens and are formed when organic material is partially oxidized by disinfectants commonly used in the water treatment industry. Additional federal mandates are expected in the near future that will also affect public water suppliers with respect to DBPs. These new federal drinking water regulations may require public water suppliers to adjust treatment practices or incorporate additional treatment operations into their existing treatment trains. Many options have been identified, including membrane processes, granular activated carbon, powered activated carbon (PAC), enhanced coagulation and/or softening, and alternative disinfectants (e.g., chlorine dioxide, ozone, and chloramines). Of the processes being considered, PAC appears to offer an attractive benefit-to-cost advantage for many water treatment plants, particularly small systems (those serving fewer than 10,000 customers). PAC has traditionally been used by the water treatment industry for the removal of compounds contributing to taste and odor problems. PAC also has the potential to remove naturally occurring organic matter (NOM) from raw waters prior to disinfection, thus controlling the formation of regulated DBPs. Many small water systems are currently using PAC for taste and odor control and have the potential to use PAC for controlling DBPs. Activated carbons can be produced from a variety of raw materials, including wood, peat, coconut husks, and numerous types of coal. The Energy & Environmental Research Center (EERC) has been working on the development of a PAC product to remove NOM from surface water supplies to prevent the formation of carcinogenic DBPs during chlorination. During that study, the sodium and calcium content of the lignites showed a significant effect on the sorption capacity of the activated carbon

  18. Distribution of 131 I- labeled Bothrops erythromelas venom in mice

    International Nuclear Information System (INIS)

    Bothrops erythromelas is responsible for many snake bites in northeastern Brazil. In the present study we determined the in vivo distribution of the venom following its subcutaneous injection into mice. B. erythromelas venom and albumin were labeled individually with 131 I by the chloramine T method, and separated in a Sephacryl S-200 column. The efficiency of labeling was 68%.Male Swiss mice (40-45 g), which had been provided with drinking water containing 0.05% KI over a period of 10 days prior to the experiment, were inoculated dorsally (sc) with 0.3 ml (2.35 x 105 cpm/mouse) of 131 I-venom (N = 42), 131 -albumin or 131 I (controls, N = 28 each). Thirty minutes and 1,3, 6, 12, 18 and 24 h after inoculation, the animals were perfused with 0.85% Na Cl and skin and various organs were collected in order to determine radioactivity content. There was a high rate of venom absorption int he skin (51%) within the first 30 min compared to albumin (20.1%) and free iodine (8.2%). Up to the third hour after injection there was a tendency for venom and albumin to concentrate in the stomach ( 3 rd h),small intestine (3 rd h) and large intestine (6th h). Both control groups had more radioactivity in the digestive tract, especially in the stomach, but these levels decreased essentially to baseline by 12-18 h postinjection. In the kidneys, the distribution profiles of venom, albumin and iodine were similar. Counts at 30 min postinjection were low in all three groups (1.37, 1.86 and 0.77, respectively), and diminished to essentially 0% by 12-18 h. Albumin tended to concentrate in muscle until the 3 rd h postinjection (1.98%).There was a low binding of labeled venom in the liver (B. erythromelas venom does not specifically target most internal organs. That is, the systemic effects of envenomation ar mainly due to an indirect action. (author)

  19. Photolytic removal of DBPs by medium pressure UV in swimming pool water

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Kamilla M.S. [Department of Environmental Engineering, Technical University of Denmark (Denmark); Zortea, Raissa [Department of Land, Environment and Geotechnology Engineering, Polytechnic University of Turin (Italy); Piketty, Aurelia [Institute of Chemistry, Industrial and Chemical Engineering and Technology (INP-ENCIACET), National Polytechnic Institute of Toulouse (France); Vega, Sergio Rodriguez [Chemical Engineering, Complutense University of Madrid (Spain); Andersen, Henrik Rasmus, E-mail: Henrik@ndersen.net [Department of Environmental Engineering, Technical University of Denmark (Denmark)

    2013-01-15

    Medium pressure UV is used for controlling the concentration of combined chlorine (chloramines) in many public swimming pools. Little is known about the fate of other disinfection by-products (DBPs) in UV treatment. Photolysis by medium pressure UV treatment was investigated for 12 DBPs reported to be found in swimming pool water: chloroform, bromodichloromethane, dibromochloromethane, bromoform, dichloroacetonitrile, bromochloroacetonitrile, dibromoacetronitrile, trichloroacetonitrile, trichloronitromethane, dichloropropanone, trichloropropanone, and chloral hydrate. First order photolysis constants ranged 26-fold from 0.020 min{sup −1} for chloroform to 0.523 min{sup −1} for trichloronitromethane. The rate constants generally increased with bromine substitution. Using the UV removal of combined chlorine as an actinometer, the rate constants were recalculated to actual treatment doses of UV applied in a swimming pool. In an investigated public pool the UV dose was equivalent to an applied electrical energy of 1.34 kWh m{sup −3} d{sup −1} and the UV dose required to removed 90% of trichloronitromethane was 0.4 kWh m{sup −3} d{sup −1}, while 2.6 kWh m{sup −3} d{sup −1} was required for chloral hydrate and the bromine containing haloacetonitriles and trihalomethanes ranged from 0.6 to 3.1 kWh m{sup −3} d{sup −1}. It was predicted thus that a beneficial side-effect of applying UV for removing combined chlorine from the pool water could be a significant removal of trichloronitromethane, chloral hydrate and the bromine containing haloacetonitriles and trihalomethanes. - Highlights: ► UV irradiation is able to degrade all 12 investigated disinfection by-products. ► Bromine species are easier to remove than their chlorinated analogues. ► UV dose used for combined chlorine was comparable with doses required for DBP removal. ► Significant removal of some disinfection by-products in swimming pools is indicated.

  20. Synthesis and evaluation of iodine-123 labelled tricyclic tropanes as radioligands for the serotonin transporter

    Energy Technology Data Exchange (ETDEWEB)

    Quinlivan, Mitchell; Mattner, Filomena; Papazian, Vahan; Zhou, Jia; Katsifis, Andrew; Emond, Patrick; Chalon, Sylvie; Kozikowski, Alan; Guilloteau, Denis; Kassiou, Michael E-mail: mkassiou@med.usyd.edu.au

    2003-10-01

    The tricyclic tropane analogues (1S,3S,6R,10S)-(Z)-10-(benzoyloxymethyl)-9-(3-chloro-4-iodobenzylidene)-7 -azatricyclo[4.3.1.0{sup 3,7}]decane, 1, and (1S,3S,6R,10S)-(Z)-9-(3-chloro-4-iodobenzylidene)-7-azatricyclo[4.3.1.0{sup 3,7}] = decane-10-carboxylic acid methyl ester, 2, have been shown to be potent and selective serotonin transporter (SERT) ligands. They possess nanomolar affinity for the SERT (Ki = 0.06 nM and 1.8 nM respectively) and are suitable for radiolabelling using iodine-123. In the present study we prepared [{sup 123}I]1 and [{sup 123}I]2 from the appropriate tributylstannane precursors using acidic media with chloramine-T as the oxidising agent. The radiochemical yield obtained for [{sup 123}I]1 varied between 50-60% while for [{sup 123}I]2 the range was 65-80%. Both radioligands were obtained with radiochemical purity > 97% and specific activity estimated to be > 185 GBq/{mu}mol. The biodistribution of [{sup 123}I]1 demonstrated low degree of brain penetration at 5 min (0.14%ID/g) with a homogenous distribution. The radioactivity cleared quickly from all brain regions with no preferential localization. In comparison, [{sup 123}I]2 demonstrated on average a higher brain uptake at 5 min (0.5%ID/g). However the distribution of radioactivity was homogenous and cleared to levels similar to [{sup 123}I]1 at 1 hr post-injection. Pre-administration of citalopram failed to show any significant inhibition of [{sup 123}I]2 uptake in the rat brain. The high lipophilicity of 1 and 2 (HPLC-derived log P{sub 7.4} values of 6.41 and 4.25 respectively) and in vivo metabolism, seen by high thyroid uptake would explain the absence of any specific binding observed in the rat brain. In view of these results [{sup 123}I]1 and [{sup 123}I]2 do not appear to be suitable radioligands for in vivo studies of the SERT.

  1. Synthesis, in vitro binding, and tissue distribution of radioiodinated 2-[{sup 125}I]N-(N-benzylpiperidin-4-yl)-2-iodo benzamide, 2-[{sup 125}I]BP: a potential {sigma} receptor marker for human prostate tumors

    Energy Technology Data Exchange (ETDEWEB)

    John, Christy S.; Gulden, Mary E.; Li, Jinghua; Bowen, Wayne D.; McAfee, John G.; Thakur, Mathew L

    1998-04-01

    The preclinical evaluation of a {sigma} receptor-specific radiopharmaceutical that binds to human prostate tumor cells with a high affinity is described. We have synthesized and radioiodinated 2-[{sup 125}I]-N-(N-benzylpiperidin-4-yl)-2-iodobenzamide (2-[{sup 125}I]BP) that possesses high affinity for both {sigma}-1 and {sigma}-2 receptor subtypes that are expressed on a variety of tumor cells. 2-IBP was synthesized, purified and characterized by routine spectroscopic and analytical methods. Radioiodination was accomplished using an oxidative iododestannylation reaction in the presence of chloramine T in high yields (76%-93%) with a very high-specific activity (1700-1900 Ci/mmol). The in vitro competition binding studies of 2-[{sup 125}I]BP with various {sigma} receptor ligands in LnCAP human prostate tumor cells showed a dose-dependent saturable binding. The inhibition constants (K{sub i}, nM) for binding of 2-[{sup 125}I]BP to human prostate tumor cells for 4-IBP, haloperidol and 2-IBP were 4.09, 6.34 and 1.6 nM, respectively. The clearance of 2-[{sup 125}I]BP, in Sprague-Dawley rats, was rapid from the blood pool, other normal tissues and the total body. Tissue distribution studies in nude mice bearing human prostate tumor (DU-145) also showed a fast clearance from normal organs. The tumor had the highest percentage of injected dose per gram (%ID/g) of all tissues at 4 h as well as 24 h (2.0 {+-} 0.05 and 0.147 {+-} 0.038 ID/g, respectively) postinjection. The in vivo receptor binding specificity was demonstrated using haloperidol (a known high-affinity {sigma} receptor ligand). A significant decrease (>50%, p = 0.001) was observed in tumor concentration when haloperidol was used as a blocking agent. The high affinity of 2-[{sup 125}I]BP for {sigma} receptor-binding sites, its fast in vivo clearance from normal organs and its high uptake and retention in tumor implies that 2-[{sup 123}I]BP or 2-[{sup 131}I]BP may be a promising tracer for noninvasive imaging of

  2. Synthesis and evaluation of [{sup 123}I] ligands for the study of the peripheral benzodiazepine receptors using SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Mattner, F.; Katsifis, A.; Mardon, K.; Papazian, V.; Najdovski, L.; Dikic, B. [Australian Nuclear Science and technology Organisation, Lucas Heights, Sydney, NSW (Australia). Radiopharmaceuticals Division

    1998-06-01

    Full text: The peripheral benzodiazepine receptors (PBR), are distinct from the central benzodiazepine receptors in their pharmacology and subcellular location. PBR`s are predominantly found in the peripheral organs such as kidney, heart, adrenal cortex, as well as in the glial cells in the brain. PBR`s have been implicated in the control of cell proliferation and differentiation and shown to display increased levels in a variety of malignant tumours. Increased levels of PBR`s have also been implicated in a variety of neurodegenerative disorders. We have prepared and evaluated [{sup 123}I]N`N`-dimethyl-6-methyl-(4`iodophenyl) midazo[l,2-a]pyridine-3-acetamide (1), [{sup 123}I]N`N`-diethyl-6-chloro-(4`iodophenyl) imidazo[l,2-a]pyridine-3-acetamide (2) and [{sup 123}l]3-benzoimidomethyl-2- (4`-t-butylphenyl)-6-iodoimidazo[1,2-b]pyridazine (3) as potential probes for the study of the PBR`s in oncology and neurodegeneration using SPECT. The iodine-123 analogues 1 and 2 were prepared by iododestannylation with Na {sup 123}I in the presence of chloramine-T and HCI. Compound 3 was prepared from the bromo precursor with Na {sup 123}I using Cu{sup +} assisted halogen exchange. In vivo biodistribution of all three compounds in rodents indicated high uptake in tissues with known PBR sites. Pre-treatment of the rats with PK 11195, Ro 5-4864 and the cold material reduced significantly the uptake of activity in organs expressing the PBR`s. Other drugs including flumazenil and haloperidol, did not significantly reduce the uptake of activity in these organs. Metabolite studies on 1 and 2 indicated high in vivo stability, however significant deiodination in vivo was observed for 3. In conclusion, ligands 1, 2 and 3 indicated high and selective in vivo uptake in organs expressing the PBR whereas ligand 3 had reduced in vivo stability. Compounds 1 and 2 are therefore suitable candidates for further development as ligands for the study of the PBR`s using SPECT

  3. Synthesis, in vitro validation and in vivo pharmacokinetics of [125I]N-[2-(4-iodophenyl)ethyl]-N-methyl-2-(1-piperidinyl) ethylamine: A high-affinity ligand for imaging sigma receptor positive tumors

    International Nuclear Information System (INIS)

    N-[2-(4-iodophenyl)ethyl]-N-methyl-2-(1-piperidinyl)ethylamine, IPEMP, and the corresponding bromo derivative, BrPEMP, have been synthesized and characterized. Both BrPEMP and IPEMP were evaluated for sigma-1 and sigma-2 subtype receptor affinities and found to possess very high affinities for both receptor subtypes. The precursor for radioiodination n-tributylstannylphenylethylpiperidinylethylamine was prepared from its bromo derivative by palladium-catalyzed stannylation reaction. Radioiodinated 4-[125I]PEMP was readily prepared in high yields and high specific activity by oxidative iododestannylation reaction using chloramine-T as oxidizing agent. Sites labeled by 4-[125I]PEMP in guinea pig brain membranes showed high affinity for BD1008, haloperidol, and (+)-pentazocine (Ki = 5.06 ± 0.40, 32.6 ± 2.75, and 48.1 ± 8.60 nM, respectively), which is consistent with sigma receptor pharmacology. Competition binding studies of 4-[125I]PEMP in melanoma (A375) and MCF-7 breast cancer cells showed a high affinity, dose-dependent inhibition of binding with known sigma ligand N-[2-(3,4-dichlorophenyl)ethyl]-N-methyl-2-(1-pyrrolidinyl) ethylamine, BD1008 (Ki = 5, 11 nM, respectively), supporting the labeling of sigma sites in these cells. Haloperidol, however showed a weaker (Ki 100-200 nM) affinity for the sites labeled by 4-[125I]PEMP in these cells. Biodistribution studies of 4-[125I]PEMP in rats showed a fast clearance of this radiopharmaceutical from blood, liver, lung, and other organs. A co-injection of 4-IPEMP with 4-[125I]PEMP resulted in 37%, 69%, and 35% decrease in activity in liver, kidney, and brain (organs possessing sigma receptors), respectively at 1-h postinjection. These results suggest that 4-[125I]PEMP is a promising radiopharmaceutical for pursuing further studies in animal models with tumors

  4. Synthesis, in vitro binding, and tissue distribution of radioiodinated 2-[125I]N-(N-benzylpiperidin-4-yl)-2-iodo benzamide, 2-[125I]BP: a potential σ receptor marker for human prostate tumors

    International Nuclear Information System (INIS)

    The preclinical evaluation of a σ receptor-specific radiopharmaceutical that binds to human prostate tumor cells with a high affinity is described. We have synthesized and radioiodinated 2-[125I]-N-(N-benzylpiperidin-4-yl)-2-iodobenzamide (2-[125I]BP) that possesses high affinity for both σ-1 and σ-2 receptor subtypes that are expressed on a variety of tumor cells. 2-IBP was synthesized, purified and characterized by routine spectroscopic and analytical methods. Radioiodination was accomplished using an oxidative iododestannylation reaction in the presence of chloramine T in high yields (76%-93%) with a very high-specific activity (1700-1900 Ci/mmol). The in vitro competition binding studies of 2-[125I]BP with various σ receptor ligands in LnCAP human prostate tumor cells showed a dose-dependent saturable binding. The inhibition constants (Ki, nM) for binding of 2-[125I]BP to human prostate tumor cells for 4-IBP, haloperidol and 2-IBP were 4.09, 6.34 and 1.6 nM, respectively. The clearance of 2-[125I]BP, in Sprague-Dawley rats, was rapid from the blood pool, other normal tissues and the total body. Tissue distribution studies in nude mice bearing human prostate tumor (DU-145) also showed a fast clearance from normal organs. The tumor had the highest percentage of injected dose per gram (%ID/g) of all tissues at 4 h as well as 24 h (2.0 ± 0.05 and 0.147 ± 0.038 ID/g, respectively) postinjection. The in vivo receptor binding specificity was demonstrated using haloperidol (a known high-affinity σ receptor ligand). A significant decrease (>50%, p = 0.001) was observed in tumor concentration when haloperidol was used as a blocking agent. The high affinity of 2-[125I]BP for σ receptor-binding sites, its fast in vivo clearance from normal organs and its high uptake and retention in tumor implies that 2-[123I]BP or 2-[131I]BP may be a promising tracer for noninvasive imaging of human prostate tumors

  5. Monoclonal antibody RM2 as a potential ligand for a new immunotracer for prostate cancer imaging

    International Nuclear Information System (INIS)

    Objectives: To investigate the potential of monoclonal antibody (mAb) RM2 as a ligand for a radioimmunotracer for prostate cancer imaging. Methods: Labeling was conducted with mAb RM2 and 125I using the chloramine-T method. The cell study was conducted with PC-3 and LNCaP, which are prostate cancer cell lines, and MCF-7, which is a breast cancer cell line. The cells were treated or untreated with unlabeled mAb RM2 to block the haptoglobin-β chains expressed on the surface of the prostate cancer cells. 125I-mAb RM2 was added into the cell culture media and cellular uptake of 125I-mAb RM2 was evaluated at 1, 3 and 6 hours of incubation. For the in vivo biodistribution study, PC-3 cells were implanted in athymic male mice. The animals were injected intravenously with 125I-mAb RM2. At 24, 48 and 72 hours after tracer injection, the animals were sacrificed and the activity levels of blood and tissue samples were determined. Results: The uptake of 125I-mAb RM2 in the PC-3 and LNCaP cells increased according to the incubation time, while the uptake of 125I-mAb RM2 in MCF-7 cells did not show any increase up to 6 hours. The increase of 125I-RM2 uptake was not observed when the PC-3 and LNCaP cells were pre-treated with unlabeled RM2. In the biodistribution studies, 125I-mAb RM2 showed marked uptake into the implanted PC-3 cells. In PC-3 tumor-bearing mice, the tumor muscle ratio of 125I-RM2 was increased for up to 72 hours in a time-dependent manner. Conclusions: 125I-mAb RM2 showed excellent prostate cancer cell targeting in vitro and in vivo. Therefore, mAb RM2 seems to be a potential candidate for an immunoligand for prostate cancer imaging.

  6. Comparative Studies on the Radiolabeling and Chromatographic Purification of Some Medically Important Compounds

    International Nuclear Information System (INIS)

    The present thesis comprises five basic chapters: The first chapter includes the main idea of our study and its problems, also includes the aim of the work of our study. The second chapter includes the theoretical consideration of the subject. It deals with the general methods of labeling, factors that influence the integrity of labeled compounds, radionuclides used for diagnostic nuclear medicine, production methods and radioactive properties of 123I, 125I and 131I. It includes also the techniques used for the preparation of the radioiodinated compounds especially the electrophilic radioiodination technique. This chapter deals also with the medical imaging, techniques of diagnostic nuclear medicine and the purification of radioiodinated compounds using different chromatographic techniques. Since these radioiodinated compounds are used for diagnosis and therapeutic treatment of human diseases, quality control tests such as determination of chemical purity, radionuclidic purity, radiochemical purity, sterility, pyrogenicity and biodistribution are performed to ensure the purity, the safety and efficiency of these products for the intended nuclear medicine application. The third chapter describes the experimental section; comprising chemicals, reagents, the radionuclides, the equipments and the counting systems used in the study. It describes the electrophilic radioiodination using chloramine-T (CAT), iodogen and lactoperoxidase oxidizing agents and the factors affecting the radiochemical yield of the radioiodination of histamine and L-tyrosine methyl ester such as substrate concentration, ph of the medium, reaction time, temperature and stability of the labeled product. This chapter also includes the techniques used in the Purification of radioiodinated compounds, including paper electrophoresis, thin layer chromatography (TLC), Poly acrylamide-acrylic acid resin [P(AAm-AA) resin] and high performance liquid chromatography (HPLC), in addition, the quality control

  7. Radioiodination and biodistribution of the monoclonal antibody TU-20 and its scFv fragment

    International Nuclear Information System (INIS)

    The ability of the monoclonal antibody TU-20 and its scFv fragment to bind specifically to the C-end of the class III β-tubulin makes these substances useful as potential diagnostics for neurodegenerative diseases-especially peripheral neuropathies. TU-20 and its scFv were labeled with 125I and 123I by chloramine-T (with radiochemical yield 75 and 50%, respectively). Radiochemical purity and stability was revealed by gel filtration (decrease to 80 and 50% in 2 months, respectively). Immunoreactivity of the labeled TU-20 was determined by ELISA - the range of the preserved immunoreactivity varies from 60 to 95% in accordance to the used radiolabeling process. RIA and affinity coupling analytic methods were specifically designed with focusing on specifics of the antibody and its fragment. The results of RIA differ in dependence on the type of the reaction vessel (glass or polystyrene) and the affinity coupling results depend on the experimental arrangement - in the batch or on the column. Fragmentation of the labeled antibody and its fragment was estimated by bis-tris gel electrophoresis followed by silver staining and autoradiography (over 95% of radioactivity bound in the substances). The antibody binding in tissue slices was studied in vitro by immunohistochemistry. The Purkinje cells were observed conjugated with the radiolabeled substances, either TU-20 or its ScFv fragment in the area of the cerebellum. In vivo biodistribution of 125I-TU-20, 125I-scFv TU-20, 123I-scFv TU-20 and Na125I was proceeded in normal mice (wild type C57B/6/J). Both biomolecules labeled by 123I were also proved in an imaging biodistribution study with use of the SPECT camera. Finally, a transgene population G93A1 Gur was used for comparative study to show the different behaviour of the substances in a normal mouse and in the modified organism with amyotrophic lateral sclerosis. The most part of differences is observed in the area of the muscles, rostal and caudal spinal cord. In summary

  8. Acute Toxicity Evaluation of Ninety-one Pesticides to Silkworm%91种农药制剂对家蚕的急性毒性研究

    Institute of Scientific and Technical Information of China (English)

    孙新友; 袁善奎; 林荣华; 王晓军; 瞿唯钢; 张燕; 高希武; 姜天明

    2011-01-01

    The acute toxicity of ninety-one pesticides to silkworm, Bombyx mori L., was evaluated in laboratory using the intake toxic leaf method, the toxic grades were compartmentalizedaccording to the results and the safety evaluation was made for these pesticides. The LC50 values of thirty pesticides were lower than 0.5mg/kg mulberry (belonged to extremely toxic grade), including emamectin benzoate, abamectin, beta-cypermethrin, bifenthrin, tebufenozide and triazophos etc. ; The LC50 values of fifteen pesticides were between 0.5-20mg/kg mulberry (belonged to high toxic grade), including carbosulfan, chlorfenapyr, triflumuron, fipronil, buprofezin, chloramine phosphorus and trichlorfon etc. ; that of ninety pesticides were between 20-200mg/kg mulberry (belonged to moderate toxic grade) ; That of twenty-seven pesticides were higher than 200mg/kg mulberry (belonged to low toxic grade).%为评价农药对家蚕的环境安全性,作者采用毒叶饲喂法在室内测定了91种农药对家蚕(BombyxmoriL.)的急性毒性,并根据其毒性范围进行分级.结果表明:有30种药剂的LC50〈0.5mg/kg桑叶,属于剧毒级,包括甲氨基阿维菌素苯甲酸盐、阿维菌素、高效氯氰菊酯、联苯菊酯、虫酰肼、三唑磷等;有15种药剂的LC50为0.5~20mg/kg桑叶,属于高毒级.如丁硫克百威、虫螨腈、杀铃脲、氟虫腈、噻嗪酮、高渗氯胺磷、敌百虫;19种药剂的LC50为20~200mg/kg桑叶,属于中等毒级;27种药剂LC50〉200

  9. Study on Disinfection and Anti-microbial Technologies for Drinking Water%饮用水的消毒及杀菌技术研究

    Institute of Scientific and Technical Information of China (English)

    朱琨; 伏小勇

    2001-01-01

    饮用水处理消毒过程中可产生一系列致癌物质,主要是氯与水中的有机物和其它化学成分反应的结果,其中典型产物有三氯甲烷.通过对常用消毒剂液氯,臭氧,二氧化氯,高锰酸钾,氯胺及过氧化氢的实验对比,证明二氧化氯是高效,方便,廉价的消毒剂.它不仅对一般病原菌类有明显的抑制和杀菌作用,对清除难以灭杀的潜原性病毒也有理想的效果.在净化水中石油类有机物时,二氧化氯的效果受到反应时间,注入方式和pH值的影响.%Disinfection by-products produced by the reaction betweenchlorine and dissolved organic compounds and other chemicals are considered as a worrying problem in the drinking water treatment process since a series of mutagenic carcinogen substances are formed including trihalomethanes (THMs). Among the tested disinfectants (chlorine, ozone, chlorine dioxide, potassium permanganate, chloramines and hydrogen peroxide etc.), chlorine dioxide has proved to be the most feasible and effective oxidant for drinking water treatment and removal of pathogens due to its oxidation efficiency, low cost and simple way of utilization. A series of experiments indicate that chlorine dioxide can significantly restrain production of trihalomethanes (THMs) and control bacteria growth particularly for Cryptosporidium oocysts.The experiments verified that both ozone and chlorine dioxide are absolutely vital to ensure that any microorganisms arising from fecal contamination of water storage are destroyed. The paper discusses oxidation capacity of chlorine dioxide, especially for removing petroleum compounds, which is affected by reaction time, gas injection way, and pH of treated water.

  10. Taurine Bromamine: Reactivity of an Endogenous and Exogenous Anti-Inflammatory and Antimicrobial Amino Acid Derivative.

    Science.gov (United States)

    De Carvalho Bertozo, Luiza; Morgon, Nelson Henrique; De Souza, Aguinaldo Robinson; Ximenes, Valdecir Farias

    2016-01-01

    Taurine bromamine (Tau-NHBr) is produced by the reaction between hypobromous acid (HOBr) and the amino acid taurine. There are increasing number of applications of Tau-NHBr as an anti-inflammatory and microbicidal drug for topical usage. Here, we performed a comprehensive study of the chemical reactivity of Tau-NHBr with endogenous and non-endogenous compounds. Tau-NHBr reactivity was compared with HOBr, hypochlorous acid (HOCl) and taurine chloramine (Tau-NHCl). The second-order rate constants (k₂) for the reactions between Tau-NHBr and tryptophan (7.7 × 10² M(-1)s(-1)), melatonin (7.3 × 10³ M(-1)s(-1)), serotonin (2.9 × 10³ M(-1)s(-1)), dansylglycine (9.5 × 10¹ M(-1)s(-1)), tetramethylbenzidine (6.4 × 10² M(-1)s(-1)) and H₂O₂ (3.9 × M(-1)s(-1)) were obtained. Tau-NHBr demonstrated the following selectivity regarding its reactivity with free amino acids: tryptophan > cysteine ~ methionine > tyrosine. The reactivity of Tau-NHBr was strongly affected by the pH of the medium (for instance with dansylglycine: pH 5.0, 1.1 × 10⁴ M(-1)s(-1), pH 7.0, 9.5 × 10 M(-1)s(-1) and pH 9.0, 1.7 × 10 M(-1)s(-1)), a property that is related to the formation of the dibromamine form at acidic pH (Tau-NBr₂). The formation of singlet oxygen was observed in the reaction between Tau-NHBr and H₂O₂. Tau-NHBr was also able to react with linoleic acid, but with low efficiency compared with HOBr and HOCl. Compared with HOBr, Tau-NHBr was not able to react with nucleosides. In conclusion, the following reactivity sequence was established: HOBr > HOCl > Tau-NHBr > Tau-NHCl. These findings can be very helpful for researchers interested in biological applications of taurine haloamines. PMID:27110829

  11. Preparation of the radiopharmaceutical 131I-Anti-CD20 for the treatment of lymphomas

    International Nuclear Information System (INIS)

    At the present time they are considered to the lymphomas like a problem of first magnitude since has happened it is necessary to be the fifth cancer cause in the world. Different treatments focused to the lymphoma like the chemotherapy and the radiotherapy, have been employees to counteract the No-Hodgkin lymphoma, without these they don't exclude the healthy tissue of the toxicity. It is for it that is taking a new direction with the employment of the directed radioimmunotherapy since this it allows to kill wicked cells selectively with radiation dose joined to the apoptosis and cytotoxicity induced by the own one bio molecule. The radioimmunotherapy with radiolabelled antibodies directed to the surface antigen CD20 represents a new modality for the treatment of No-Hodgkin lymphoma and potentially other illnesses. In this work the parameters of optimization are presented for the preparation, control of quality and evaluation of the stability in vitro and in vivo of the monoclonal antibody anti-CD20 labelled with 131 I for the treatment of No-Hodgkin lymphoma. The anti-CD20 labelled by the chloramine-T method with high radiochemical purity (>98%), it is stable in solution for but of a half life of the radionuclide (8.04 days) The 131 I-anti-CD20 doesn't present dehalogenation in vitro (human serum) during 24 h of incubation at 37 C. According to the tests carried out to establish the immunoreactivity, a percentage of union to cells was obtained (B lymphocytes) bigger to 30%. The biodistribution in mice balb/c one hour after their administration, it shows that there is not high reception in mucous neither kidneys, what indicates that the complex is stable in vivo. In conclusion, the radiopharmaceutical 131 I-anti-CD20 was obtained in sterile injectable solution and free of pyrogens with a radiochemical purity bigger to 98% and a specific activity of 296 MBq. The radiolabelled molecule maintains its biological recognition for the receiving CD20 highly expressed in

  12. Seasonal evaluation of the presence of 46 disinfection by-products throughout a drinking water treatment plant

    Energy Technology Data Exchange (ETDEWEB)

    Serrano, Maria; Montesinos, Isabel; Cardador, M.J.; Silva, Manuel; Gallego, Mercedes, E-mail: mercedes.gallego@uco.es

    2015-06-01

    In this work, we studied a total of 46 regulated and non-regulated disinfection by-products (DBPs) including 10 trihalomethanes (THMs), 13 haloacetic acids (HAAs), 6 halonitromethanes (HNMs), 6 haloacetonitriles (HANs) and 11 aldehydes at different points in a drinking water treatment plant (DWTP) and its distribution network. Determining an increased number of compounds and using accurate, sensitive analytical methodologies for new DBPs can be useful to overcome some challenges encountered in the comprehensive assessment of the quality and safety of drinking water. This paper provides a detailed picture of the spatial and seasonal variability of DBP concentrations from raw water to distribution network. Samples were collected on a monthly basis at seven different points in the four seasons of a year to acquire robust data for DBPs and supplementary quality-related water parameters. Only 5 aldehydes and 2 HAAs were found in raw water. Chlorine dioxide caused the formation of 3 new aldehydes (benzaldehyde included), 5 HAAs and chloroform. The concentrations of DBPs present in raw water were up to 6 times higher in the warmer seasons (spring and summer). The sedimentation process further increased their concentrations and caused the formation of three new ones. Sand filtration substantially removed aldehydes and HAAs (15–50%), but increased the levels of THMs, HNMs and HANs by up to 70%. Chloramination raised the levels of 8 aldehydes and 7 HAAs; also, it caused the formation of monoiodoacetic acid, dibromochloromethane, dichloroiodomethane and bromochloroacetonitrile. Therefore, this treatment increases the levels of existing DBPs and leads to the formation of new ones to a greater extent than does chlorine dioxide. Except for 5 aldehydes, the 23 DBPs encountered at the DWTP exit were found at increased concentrations in the warmer seasons (HAAs by about 50% and THMs by 350%). - Highlights: • Occurrence of 46 regulated and non-regulated DBPs through a DWTP was

  13. Estimation of progesterone in bovine milk by liquid phase radioimmunoassay for veterinary applications

    International Nuclear Information System (INIS)

    Full text: Reproductive management is a major concern for the dairy industry which, with inefficient estrous detection, causes significant economic loses. The level of progesterone, which is a steroid hormone of molecular weight 314.5 D, as an early indicator of pregnancy, is becoming increasingly popular. This now has become an essential tool for the veterinarians and the farmers in making early diagnosis and decisions on culling and rebreeding for economic herd management. The standardization of a direct radioimmunoassay for the estimation of progesterone in bovine milk using 125I-labelled progesterone prepared by radio iodinating the tyrosine methyl ester (TME) conjugated to progesterone and a specific antibody is described. The conjugate was radioiodinated with 125I using chloramine-T and purified by gel-filtration. Radiochemical purity of the tracer was found to be >98%. A set of seven individual progesterone standards in buffer was prepared in lyophilized form. Milk samples for the preparation of progesterone free milk was collected during the heat period. After checking for the non-specific binding and specific binding, in these samples, they were further processed. Potassium dichromate was added to these samples for prolonged storage. Further, the milk was skimmed by centrifuging at 2000g for 15 minutes. Various assay parameters, such as, buffer, volume of the matrix, milk/sample/standard, incubation condition, total reaction volume, and separation system were studied in detail to optimize the assay. Non-specific binding was found to be <5% and specific binding was found to be 30-50%. No blocking agents were added in the milk sample during the assay. The assay involves the incubation of progesterone antibody along with individual standards or sample and radiolabelled tracer for 2 hours at room temperature. The assay range was 0-50ng/ml where the volume of standard/sample was 50μl. The developed assay was further validated where the intra and inter assay

  14. Biochemical and pharmacological studies of native and irradiated crotamine with gamma radiation of 60Co

    International Nuclear Information System (INIS)

    Ionizing radiation can change the molecular structure and affect the biological properties of biomolecules. This has been employed to attenuate animal toxins. Crotamine is a strongly basic polypeptide from the South American rattlesnake venom, composed of 42 amino acid residues. It induces skeletal muscle spasms leading to a spastic paralysis of hind limbs in mice. The objective of this thesis was carry out biochemical and pharmacological studies of native and irradiated crotamine with 60 Co. Crotamine was purified from Crotalus durissus terrificus venom by Sephadex G-100 gel filtration followed by ion exchange chromatography, using a Fast Performance Liquid Chromatography (FPLC) system. It was irradiated at 2 mg/ml in 0.15 M Na Cl with 2.0 kGy gamma radiation emitted by a 60 Co source. The native and irradiated crotamine were evaluated by biochemical characterization, toxic activity (LD50 and biodistribution. The native and irradiated crotamine were labelled with 29.6 MBq of 125 I using chloramine T method, and separated in a Sephadex G-50 column. Male Swiss mice (35± 5 g), were injected i.p. with o.1 mL (2.4 x 106 cpm/mouse) of 125 I native crotamine or with 0.4 mL (1.3 x 106 cpm/mouse) of 125 I irradiated crotamine. At 0.08; 0.25; 0.5; 1; 2; 4; 8; 12 and 24 hours the animal were killed by ether inhalation. Blood, spleen, liver, kidneys, brain, lungs, heart, and skeletal muscle were collected in order to determine radioactivity content. The results showed that gamma radiation did not change the protein concentration, the electroforetic profile or the primary structure of the protein, although differences were shown by spectroscopic techniques. The gamma radiation diminished the toxicity of crotamine, but it did not abolish bioactivity. Biodistribution studies showed that native and irradiated crotamine have hepatic metabolism and renal elimination. The native and irradiated crotamine have affinity by skeletal muscle and they did not pass the blood - brain

  15. Relation between human myocardial acidic isoferritin and hepatoma

    International Nuclear Information System (INIS)

    Acid iso ferritin (AIF), a ferritin isomer with a high proposition of H subunit, is different from basic iso ferritin (BIF) biochemically and immunologically. AIF was isolated and purified from human myocardium and the antiserum was obtained by immunizing the rabbits. A radioimmunoassay (RIA) of AIF and an immunoradiometric assay of AIF-H subunit were established by preparing 125I-AIF and 125I-AIF-H McAb using the chloramine-T method. The intra-and inter-assay CV of AIF RIA were 1.65% and 9.71%, respectively. The recovery rate was 102%. The antiserum provided a linear response from 7.0∼369.6μg/L, with ED50 of 27.50 μg/L. AIF-H IRMA methodological study found that the intra- and inter- assay CV were 2.44% and 10.16%, respectively. The sensitivity was 0.74 μg/L, the recovery rate was 92.29% and ED50 was 23.05 μg/L. The cross-reactivity of the two assays with AFP, CEA and lactoferrin was negligible, while that with BIF was 1.74% and 3.13%, respectively. The serum AIF concentration showed a considerable variation in different sexes and age groups. Its sensitivity for diagnosis of hepatic cancer was 73.05%, independent on the severity of hepatic injury. In eight kinds of malignant tumors studied, AIF was found to be most valuable in diagnosis of hepatic cancer, with its positive, negative false-positive and false-negative rates being all ideal. The patients with hepatoma had increased concentration of serum AIF-H subunit, so measuring the ratio of H/L subunits was valuable for studying the diseases. These results suggest that AIF may turn to be a rather specific index of hepatic cancer. Combination of monitoring both AIF and AFP would raise the rate of detection of positive cases and improve the specificity of method for the diagnosis of hepatic cancer. (15 refs., 4 figs., 6 tabs.)

  16. Modulation of the Pharmacological and Biochemical Actions of Leiurusquinquestriatus (L.q Scorpion Venom by Exposure to Gamma Radiation

    Directory of Open Access Journals (Sweden)

    Heba A. Mohamed*, Esmat A. Shaaban* , Aber M Amin** and Sanaa A. Kenawy

    2011-07-01

    Full Text Available This study was undertaken to evaluate the effect of gamma radiation (1.5 KGy & 3 KGy on L.q scorpion venom. This was carried out by studying the toxicological, biochemical & immunological properties of the venom before and after exposure to gamma radiation. Material and methods Animals, venom, antivenin, gamma radiation, 125I. Results Data revealed that the toxicity of irradiated venom (1.5 KGy & 3 KGy decreased as compared to that of the native one. LD50 of irradiated venom were 3.5 mg/kg & 7.5 mg/kg respectively while, that of the native venom was (0.39 mg/kg. Moreover, the distribution of 125I-labeled L.q venom was studied in male Swiss mice tissue using chloramine-T method by being injected intravenously. At various time intervals, urine and blood were collected and the animals were sacrificed. Brain, lungs, heart, liver, kidneys, spleen, intestine, bone and muscle were isolated in order to determine the radioactivity content. The highest contents of 125I-labeled L.q venom were found in the liver and kidney that were quickly excreted into the urinary tract. Trial to label irradiated (1.5 & 3 KGy L.q venom was unsuccessful due to its decomposition. For that reason the utilization of the labeled irradiated L.q venom is of no meaning. In immunodiffusion technique, both irradiated and native venoms exhibited prominent precipitin bands indicating high concentration of specific antibodies against polyvalent antivenin with venom. Furthermore, the effect of half the LD50 of native or irradiated (1.5 KGy L.q venom was studied on the activities of certain enzymes: ASAT, ALAT, LDH, CPK, CPK-MB, and the levels of total cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol and the oxidative stress biomarkers (plasma MDA & blood GSH. Biochemical measurements showed that scorpion venom envenomation caused significant (p < 0.05 elevation in serum ASAT, ALAT, LDH, CPK as well as CPK-MB activities, blood GSH level while, caused significant (p < 0

  17. The in vivo pharmacokinetics study of anti-ProGRP(31-98) monoclonal antibody E-B5

    International Nuclear Information System (INIS)

    Objective: Progastrin-releasing peptide(31-98) (ProGRP(31-98) is a specific tumor marker in patients with small cell lung cancer (SCLC). E-B5 antibody against ProGRP(31-98) was produced by China Institute for Radiation Protection. The aim of this study was to explore the 131I labeling methods, stability, immunological activity and biological distribution pattern of E-B5 antibody against ProGRP(31-98). Methods: Chloramine-T method was used for 131I labeling E-B5 antibody. Labeling efficiency, radiochemical purity and stability were estimated by using paper chromatography method. Immunological activity of 131I-E-B5 was detected with cell conjugation assay. After healthy Kunming mice were injected with 131I-E-B5 antibody through tail veil, the biodistribution and pharmacokinetics of 131l-E-B5 antibody in healthy Kunming mice were studied. Continuous images of the nude mice beating SCLC were carried out at different time points after injection of 131I-E-B5 antibody. Continuous variables were expressed as x-bar ± s and compared by t-test with SPSS 13.0 software. Results: The labeling efficiency and radiochemical purity of 131I-E-B5were 90.8%, 99.28%, respectively. The radiochemical purity still maintained above 70% after incubation in water bath at 37 degree C for 24 h. After incubation with healthy serum for 24 h, the radiochemical purity still reached 68.1%. The immunobinding ratios were 71.6% and 33.2% for NCI-H446 cells and A549 cells respectively. The in vivo distribution and elimination of 131I-E-B5 antibody were consistent with a first-order and two-compartment model, t1/2α =0.2 h, t1/2β = 8.35 h. The metabolism of 131I-E-B5 antibody mainly depended on liver and kidney and with rapid elimination in blood. Conclusions: 131I-E-B5 antibody not only has high labeling efficiency and radiochemical purity, but also has good stability and keeps good immunological activity. 131I-E-B5 is a promising agent of radioimmunoimaging and radioimmunotherapy of SCLC. (authors

  18. Vasoactive intestinal peptide receptor scintigraphy in patients with pancreatic adenocarcinomas or neuroendocrine tumours

    International Nuclear Information System (INIS)

    Human adenocarcinomas of the gastroenteropancreatic system overexpress vasoactive intestinal peptide (VIP) receptors and therefore represent logical diagnostic targets for receptor scintigraphy. Using iodine-123 labelled VIP, the newly employed diagnostic procedure termed VIP receptor scintigraphy (VIP-RS) appears to detect tumour tissue, especially pancreatic metastatic tumours, in almost all cases. So far, however, only a single centre has demonstrated convincing positive results. The aim of this study was to compare the sensitivity and specificity of VIP-RS with those of computer tomography (CT) and transabdominal ultrasound in patients with extensive pancreatic metastatic adenocarcinomas and neuroendocrine tumours. VIP was radiolabelled with carrier-free 123I using the chloramine T-method and preparative high-performance liquid chromatography for purification. Patients with metastatic pancreatic (n=12) and colorectal (n=3) carcinomas (adenocarcinoma: n=13, neuroendocrine tumour: n=2) were studied by VIP-RS, CT, ultrasound and, in one case, also by radioligand receptor autoradiography. Carrier-free radioiodinated VIP of maximum specific radioactivity maintained a high biological activity as determined by cAMP formation in receptor-expressing tumour cell lines. Intravenous injection of 123I-VIP did not cause any side-effects. Biodistribution, determined over 24 h, was high in the lungs and low in abdominal organs. Although all patients had extensive metastatic disease as evidenced by CT and ultrasound, VIP-RS was unable to detect either primaries or metastases in these patients. Only in two patients could a significant uptake of radiolabel be detected in organs directly infiltrated by the primary. To exclude false-negative findings, tumour tissue in one patient with a large primary, undetectable by VIP-RS, was analysed by radioligand receptor autoradiography and shown to be receptor positive. Moreover, in vitro receptor determinations showed that pancreatic

  19. Radioiodine-labeling of salidroside and its biodistribution in mice

    International Nuclear Information System (INIS)

    To investigate the preparation of radioiodinated salidroside and its cell uptake in SH-SY5Y and its biodistribution in mice, salidroside was labeled with 131I using the chloramine-T method and the radiolabeled compound was characterized by polyamide TLC, in which the substratum of Vtrichoromethane:Vmethanol:Vacetone:Vwater=6:3:1:1 was used as the developing agent. The uptake of 131I-salidroside in human neuroblast cells (SH-SY5Y) and mammary cancer cells (MCF-7) was then measured and the biodistribution studies were carried out in KM mice. At different time (5, 10, 30, 60, 120, and 240 min) after radiopharmaceutical i.v. administration (1.85 MBq 131I-salidroside/mouse), the animals were sacrificed (n=5 animals for each time). Blood and the interested tissues samples were collected, washed, weighted and counted. The percent injected dose per gram (%ID/g) was calculated for each sample. The labeling yield of 131I-salidroside was 98% and its RCPs were 98.5%, 97.3% and 97.1% after 1, 4 and 20 days, respectively. In SH-SY5Y, 131I-salidroside uptake kept at a low level of around 0.035% from 0.5 to 4h, while in MCF-7 a slightly higher uptake of 0.1% was reached. Biodistribution in mice demonstrated that 131I-salidroside was metabolized mainly in liver and rapid elimination through kidney, in which the % ID/g were 7.71% and 11.31% at 5 min, 0.36% and 0.3% at 4h, respectively. Rapid clearance was also found in blood, 6.43% at 5 min and 0.11% at 4h. In heart, lung, spleen, muscle, bone, and intestines, there were little distributions. It is concluded that labeling yield of 131I-salidroside was high and the radioiodinated salidroside was stable, but its uptake in neuroblast was little. (authors)

  20. Improved iodine radiolabels for monoclonal antibody therapy.

    Science.gov (United States)

    Stein, Rhona; Govindan, Serengulam V; Mattes, M Jules; Chen, Susan; Reed, Linda; Newsome, Guy; McBride, Bill J; Griffiths, Gary L; Hansen, Hans J; Goldenberg, David M

    2003-01-01

    A major disadvantage of (131)iodine (I)-labeled monoclonal antibodies (MAbs) for radioimmunotherapy has been the rapid diffusion of iodotyrosine from target cells after internalization and catabolism of the radioiodinated MAbs. We recently reported that a radioiodinated, diethylenetriaminepentaacetic acid-appended peptide, designated immunomedics' residualizing peptide 1 (IMP-R1), was a residualizing iodine label that overcame many of the limitations that had impeded the development of residualizing iodine for clinical use. To determine the factors governing the therapeutic index of the labeled MAb, as well as the factors required for production of radioiodinated MAb in high yield and with high specific activity, variations in the peptide structure of IMP-R1 were evaluated. A series of radioiodinated, diethylenetriaminepentaacetic acid-appended peptide moieties (IMP-R1 through IMP-R8) that differed in overall hydrophilicity and charge were compared. Radioiodinations of the peptides followed by conjugations to disulfide-reduced RS7 (an anti-epithelial glycoprotein-1 MAb) furnished radioimmunoconjugates in good overall incorporations, with immunoreactivities comparable to that of directly radioiodinated RS7. Specific activities of up to 8 mCi/mg and yields > 80% have been achieved. In vitro processing experiments showed marked increases in radioiodine retention with all of the adducts; radioiodine retention at 45 h was up to 86% greater in cells than with directly iodinated RS7. Each of the (125)I-peptide-RS7 conjugates was compared with (131)I-RS7 (labeled by the chloramine-T method) in paired-label biodistribution studies in nude mice bearing human lung tumor xenografts. All of the residualizing substrates exhibited significantly enhanced retention in tumor in comparison to directly radioiodinated RS7, but the nontarget uptakes differed significantly among the residualizing labels. The best labels were IMP-R4 and IMP-R8, showing superior tumor-to-non-tumor ratios

  1. Biochemical and pharmacological studies of native and irradiated crotamine with gamma radiation of {sup 60}Co; Estudo bioquimico e farmacologico das crotaminas nativa e irradiada com radiacao gama de {sup 60}Co

    Energy Technology Data Exchange (ETDEWEB)

    Mitake, Malvina Boni

    2000-07-01

    Ionizing radiation can change the molecular structure and affect the biological properties of biomolecules. This has been employed to attenuate animal toxins. Crotamine is a strongly basic polypeptide from the South American rattlesnake venom, composed of 42 amino acid residues. It induces skeletal muscle spasms leading to a spastic paralysis of hind limbs in mice. The objective of this thesis was carry out biochemical and pharmacological studies of native and irradiated crotamine with {sup 60} Co. Crotamine was purified from Crotalus durissus terrificus venom by Sephadex G-100 gel filtration followed by ion exchange chromatography, using a Fast Performance Liquid Chromatography (FPLC) system. It was irradiated at 2 mg/ml in 0.15 M Na Cl with 2.0 kGy gamma radiation emitted by a {sup 60} Co source. The native and irradiated crotamine were evaluated by biochemical characterization, toxic activity (LD{sub 50} and biodistribution. The native and irradiated crotamine were labelled with 29.6 MBq of {sup 125} I using chloramine T method, and separated in a Sephadex G-50 column. Male Swiss mice (35{+-} 5 g), were injected i.p. with o.1 mL (2.4 x 10{sup 6} cpm/mouse) of {sup 125} I native crotamine or with 0.4 mL (1.3 x 10{sup 6} cpm/mouse) of {sup 125} I irradiated crotamine. At 0.08; 0.25; 0.5; 1; 2; 4; 8; 12 and 24 hours the animal were killed by ether inhalation. Blood, spleen, liver, kidneys, brain, lungs, heart, and skeletal muscle were collected in order to determine radioactivity content. The results showed that gamma radiation did not change the protein concentration, the electroforetic profile or the primary structure of the protein, although differences were shown by spectroscopic techniques. The gamma radiation diminished the toxicity of crotamine, but it did not abolish bioactivity. Biodistribution studies showed that native and irradiated crotamine have hepatic metabolism and renal elimination. The native and irradiated crotamine have affinity by skeletal

  2. Preparation of the radiopharmaceutical {sup 131}I-Anti-CD20 for the treatment of lymphomas; Preparacion del radiofarmaco {sup 131}I-Anti-CD20 para el tratamiento de linfomas

    Energy Technology Data Exchange (ETDEWEB)

    Pantoja H, I.E

    2004-07-01

    At the present time they are considered to the lymphomas like a problem of first magnitude since has happened it is necessary to be the fifth cancer cause in the world. Different treatments focused to the lymphoma like the chemotherapy and the radiotherapy, have been employees to counteract the No-Hodgkin lymphoma, without these they don't exclude the healthy tissue of the toxicity. It is for it that is taking a new direction with the employment of the directed radioimmunotherapy since this it allows to kill wicked cells selectively with radiation dose joined to the apoptosis and cytotoxicity induced by the own one bio molecule. The radioimmunotherapy with radiolabelled antibodies directed to the surface antigen CD20 represents a new modality for the treatment of No-Hodgkin lymphoma and potentially other illnesses. In this work the parameters of optimization are presented for the preparation, control of quality and evaluation of the stability in vitro and in vivo of the monoclonal antibody anti-CD20 labelled with {sup 131} I for the treatment of No-Hodgkin lymphoma. The anti-CD20 labelled by the chloramine-T method with high radiochemical purity (>98%), it is stable in solution for but of a half life of the radionuclide (8.04 days) The {sup 131} I-anti-CD20 doesn't present dehalogenation in vitro (human serum) during 24 h of incubation at 37 C. According to the tests carried out to establish the immunoreactivity, a percentage of union to cells was obtained (B lymphocytes) bigger to 30%. The biodistribution in mice balb/c one hour after their administration, it shows that there is not high reception in mucous neither kidneys, what indicates that the complex is stable in vivo. In conclusion, the radiopharmaceutical {sup 131} I-anti-CD20 was obtained in sterile injectable solution and free of pyrogens with a radiochemical purity bigger to 98% and a specific activity of 296 MBq. The radiolabelled molecule maintains its biological recognition for the receiving

  3. Experimental study of radiotargeting-therapy with small molecular polypeptide in nude mice bearing lung adenocarcinoma

    International Nuclear Information System (INIS)

    Background: Integrin signal transduction pathways provide an important basis for molecular targeting therapy of cancer in tumor growth, infiltration and transfer. Existing research data have shown that small molecular peptide labeled with radionuclide has good clinical application prospects, but the successful researches on lung cancer have not been reported so far. It is considered that the main reason is the lack of small molecule peptide for specific targeting lung cancer. Purpose: Based on the small molecular peptide cNGQGEQc for specifically identifying integrin α3 and β1 found previously, polypeptide cNGQGEQc is selected and radiolabelled with 131I. And the inhibitory effect of 131I-cNGQGEQc in nude mice bearing lung adenocarcinoma is observed. Methods: The coupling of cNGQGEQc and tyrosine was done in the processing of solid phase synthesis of small molecular peptide. Chloramine-T method was used for radiolabelling of cNGQGEQc with 131I. Twenty nude mice bearing NCI-H1975 were built and randomly divided into four groups with five mice in each group, including the group of 131I-cNGQGEQc, the group of 131I-cNAQAEQc, the group of 131I and the saline control group. The general condition was observed in nude mice bearing tumor after tail vein injection of corresponding drugs. And the tumor sizes after grafting were measured per 3 days in 30 days. The inhibitory rate of tumor in each group was calculated. Results: The labeling efficiencies of 131I-cNGQGEQc and 131I-cNAQAEQc were greater than 90% with the radiochemical purity of more than 95%, and 131I-cNGQGEQc had obvious inhibitory effect for transplantation tumor in nude mice bearing NCI-H1975 adenocarcinoma of lung. After a treatment for 30 days the tumor inhibitory rates were 60.93% for the group of 131I-cNGQGEQc, 11.63% for the group of 131I-cNAQAEQ and 10.70% for the group of 131I. Conclusion: 131I-cNGQGEQC has a good affinity and effective inhibit effect for the NCI-H1975 lung adenocarcinoma. Integrin is

  4. Comparison of [131I]-Tyr3-octreotate and [131I]DOTA-Tyr3-octreotate: the effect of DOTA on the pharmacokinetics and stability

    International Nuclear Information System (INIS)

    The introduction of radiolabeled somatostatin analogs for peptide receptor imaging and therapy of neuroendocrine cancer have become a primary focus of interest in nuclear medicine. In this work we studied the possibility of preparing radioiodinated octreotate derivatives, with high stability and favourable kinetic in vivo, because 131I-iodide is most frequently used in therapeutic nuclear medicine and aviable. We studied molar peptide to radionuclide ratio in order to obtain the mono-iodinated peptide (di-iodinated no longer binds to the somatostatin receptor). Like other radioiodinated proteins labeled on constituent tyrosine residues, it was important to study the possibility of dehalogenation in vivo. Despite DOTA chelating group was not necessary to the radioiodination procedure, we intended to evaluate the influence of the chelating group on the pharmacokinetic and the in vivo stability of the labeled peptide. 131I radiolabeling of Tyr3-octreotate and DOTA-Tyr3-octreotate was performed using Chloramine T method. A solution of 10 μg of peptide/40 μL of PBS (0.05M phosphate-buffered saline pH 7.5) was transferred to an Eppendorf cap. After addition of 10 μL (74 MBq) radioiodine and 5 μL of chloramine T solution (1mg/mL PBS), the cap was carefully stirred and the labeling reaction was allowed to proceed for 3 minutes at room temperature; 5 μL of sodium methabisulfite solution (2mg/mL PBS) was introduced as reducing agent. Radiochemical purity was determined by HPLC (Waters) using a RP C18 column (4.2 x 50 mm, 5 μm, Waters) with UV (230 nm) and radioactivity (Packard Canberra) detection, flow rate of 0.5 mL/minute with a linear gradient of 40-80% (v/v) methanol in 50 mM sodium acetate buffer (pH 5.5) for 20 minutes, maintained for another 25 minutes. Free radioiodine was also determined by horizontal zone electrophoresis (Amershan Pharmacia) on Whatman 1 paper, 0.05M barbital buffer, pH 8.6, 300V, 40 minutes. The stability of the compounds were evaluated

  5. Iodine labelled diethylstilbestrol (DES) of high specific activity: A potential radiopharmaceutical for therapy of estrogen receptorpositive tumours and their metastases?

    International Nuclear Information System (INIS)

    After binding to the estrogen receptor (ER) estrogens are localized very close to the DNA. Therefore, radioactively labelled estrogens, especially in connection with Auger-electron emitters which have only a very short range (1-10 nm) of radiation, are excellent candidates to achieve high specific cytotoxicity, in combination with a low degree of side effects. Diethylstilbestrol (3,4-Di-(4'-hydroxyphenyl)-hexene-3) is a well-known, synthetic, non-steroidal estrogen, which has a higher affinity to the estrogen receptor than the natural hormone estradiol itself. The idea to use iodine labelled DES for imaging of ER positive tumours is not new. Several working groups successfully tried to label DES with different methods and investigated the diagnostic usefulness of the product. Most attempts for labelling with radioiodine have been made with a water soluble derivate of DES, the tetra-sodium salt of diethylstilbestrol-diphosphate (DES-2P). Former labelling methods had some disadvantages: low yield (20-30%), low specific activity (0.7 - 2.9 GBq/mmol), bad reproducibility, and time consuming procedures. Presumably, the low specific activity was the reason for the unsatisfying biodistribution data observed with this labelled compounds. In the present work a fast and simple labelling and purification method for *I-DES was used and its binding affinity for ER was determined. For testing its cytotoxic effects on MCF-7 mamma carcinoma cells different iodine isotopes bound to DES or in form of iodide were compared with regard to apoptosis, necrosis, and viability. Last but not least first animal experiments with tumour bearing mice were carried out. DES was iodinated by Chloramine T in methanolic solution. Purification and quality control was carried out with reversed phase HPLC (column: Column: Hypersil ODS, 250 x 4 mm, 10 Ym, Eluent A: Methanol G, Eluent B: Water G, Gradient: 20% A to 70% A within 5 min, Flow: 1 ml/min, UV-Detection: 254 nm). The dissociation constants for

  6. Administering of I-125 preparation from blood of tortoise into organs of rats with experimental ovarian carcinoma

    International Nuclear Information System (INIS)

    Full text: Complexes of substances of the peptide nature, received mainly from lymphoid bodies that normalize immune processes, are offered. The preparation 'Tortesin' can be related to this group. Tortesin is a drug isolated from the blood cells of the Central Asian tortoise, an animal with a unique radioresistance (LD50 = 100 Gy). During a short spring the tissues of tortoises produce biogenetic stimulators that can positively affect the organisms of irradiated animals. Tortesin acts by stimulating haemo- and immunopoietic systems and aids in recovery from radiation exposure. Thus, at animals treated with Tortesin, DNA and RNA synthesis in the bone marrow was enhanced, both antibody forming cells number and spleenic size increased, and haemopoietic parameters normalized. The survival rate also increased. That is why the determination of the point of initial application of the preparation is an important scientific objective. The research with the use of 125I was carried out for this purpose. The labeling was conducted via reaction with chloramine T. The preparation 125I issued by 'Radiopreparat' (Tashkent) was used. After the purification by chromatography the activity of 1000 impulse/min by 1 μg of protein was got. The experiment was carried out in the Center of oncology and radiology Republic of Uzbekistan. The including of the marker was being determined in young rats at the age of 1 month with an experimental ovarian carcinoma in 15 min, 1 hour and 1 day after the injection. The preparation was injected into the tail vein. The following 22 organs were examined: blood, ascitic fluid with cells, ascitic fluid without cells, tumor, liver, spleen, stomach, bowels, lungs, heart, testicles, kidneys, cerebral, marrow, thymus, fat, muscles, skin, thyroid gland, thigh-bone, tail, excrements. The results can be classified into three groups. The first group of organs (heart, cerebral, cells from tumor, thigh-bone, marrow, thyroid gland, thymus,) do not include the

  7. Utilization of N-X bonds in the synthesis of N-heterocycles.

    Science.gov (United States)

    Minakata, Satoshi

    2009-08-18

    Nitrogen-containing heterocycles--such as aziridines, pyrrolidines, piperidines, and oxazolines--frequently show up as substructures in natural products. In addition, some of these species show potent biological activities. Therefore, researchers would like to develop practical and convenient methods for constructing these heterocycles. Among the available methods, the transfer of N(1) units to organic molecules, especially olefins, is a versatile method for the synthesis of N-heterocycles. This Account reviews some of our recent work on the synthesis of N-heterocycles using the N-X bond. A nitrogen-halogen bond bearing an electron-withdrawing group on the nitrogen can be converted to a halonium ion. In the presence of C-C double bonds, these species produce three-membered cyclic halonium intermediates, which can be strong electrophiles and can produce stereocontrolled products. N-Halosuccinimides are representative sources of halonium ions, and the nitrogen of succinimide is rarely used in organic synthesis. If the nitrogen could act as a nucleophile, after releasing halonium ions to C-C double bonds, we expect great advances would be possible in the stereoselective functionalization of olefins. We chose N-chloro-N-sodio-p-toluenesulfonamide (chloramine-T, CT), an inexpensive and commercially available reagent, as our desired reactant. In the presence of a catalytic amount of CuCl or I(2) and AgNO(3), we achieved the direct aziridination of olefins with CT. The reaction catalyzed by I(2) could be carried out in water or silica-water as a green process. The reaction of iodoolefins with CT gave pyrrolidine derivatives under extremely mild conditions with complete stereoselectivity. We also extended the utility of the N-chloro-N-metallo reagent, which is often unstable and difficult to work with. Although CT does not react with electron-deficient olefins without a metal catalyst or an additive, we found that N-chloro-N-sodiocarbamates react with electron

  8. EDTA在后牙钙化闭塞根管预备中的应用研究%EDTA Application Research in the Calcified Block Root Canal Preparation of the Back Teeth

    Institute of Scientific and Technical Information of China (English)

    卢山; 黄昭毅; 郭宏剑

    2013-01-01

    Objective:The calcified block root canals have greatly influenced the curative effect to the root canals.To observe the EDTA paste in the application of calcified block root canal preparation,evaluate its clinical efficacy.Method:One hundred and twenty-four patients in our department from March 2009 to March 2012 were selected,140 back molar teeth,165 calcified block root canals and then divide them randomly into the group A and the group B,62 cases in each group.There were 62 cases,68 back molar teeth and 83 calcified block root canals in the group A.The group A was treated with the EDTA paste into root canal occlusion for root canal preparation,or temporary seal root canal EDTA root canal preparation a week later.There were 62 cases,72 back molar teeth and 82 calcified block root canals in the group B.The group B was treated with chloramine into the calcified block root canals and then had a root canal preparation.The preparatory effect of the root canals according to the X-ray and clinical examination were evaluated. Result:Eighty-three calcified block root canal in the group A with 72 root canal expansion,prepared well,the success rate was 86.75%.82 calcified block root canal in the group B only 18 root canal in root canal expansion,the success rate was 21.95%,and the breakage rate increased,the difference was statistically significant(P<0.01).Conclusion:The effect that EDTA paste has been used in the calcified block root canals is very good.It can raise remarkably the successful rate of root canal preparation.%目的:钙化闭塞根管严重影响根管治疗效果,通过观察EDTA糊剂在钙化闭塞根管预备中的应用,评价其临床疗效。方法:选取2009年3月-2012年3月本院牙体牙髓科就诊的124例患者,140颗后磨牙,165个钙化闭塞根管,所有的患者按照随机数字表法分为A组和B组各62例。A组62例68颗后磨牙83个钙化闭塞根管采用EDTA糊剂导入根管闭塞处进行根管预备,或根管

  9. Radiolabelled DOTA-TATE: Its evaluation for targeted radiotherapy

    International Nuclear Information System (INIS)

    The development of a radiopharmaceutical for cancer therapy based on a somatostatin analog peptide DOTATATE (DOTA-D-phe-cys-tyr-D-trp-lys-thr-cys-thr) labelled with I-125 was done and the biological properties were investigated. Labelling of the DOTA-TATE was achieved by oxidation of iodide with Chloramine-T. Purification was done by C18 separation cartridge using ethanol as the eluent and further reverse-phase chromatography (HPLC) on the eluate to increase specific activity. Stability of the labelled peptide at different time intervals as well as storing conditions was evaluated by RPHPLC and by chromatography in ITLC-SG or Whatman 3MM using different mobile phases: 2-butanone (MEK); NaCl 0.9%; EtOH-HCl 0.01N 90:10 and butanol:acetic:H O (4:1:5) (2). Also, electrophoresis was 2 done on Whatman 1 with Tris buffer, (pH 7.5, 200V, 80mA, 45 min). Biological behaviour of I-125 DOTA-TATE was evaluated through interaction with somatostatin receptors extracted from rat cortex membranes as well as from AR4- 2J cell membranes. In vitro binding of the peptide to viable AR4-2J was evaluated through internalization studies. The labelling yield obtained was higher than 95%. HPLC profile revealed that two radiochemical species were present having retention times of 23.5 and 25.0 min, while the unlabelled peptide eluted at 21.0 min. I-125 DOTATATE was obtained with very high yield even prior purification. The two radiochemical species evidenced by RP-HPLC could be interpreted as mono and diiodinated radio-conjugate species. Their retention times are slightly higher than the intact unlabelled peptide allowing the preparation of a labelled molecule with high specific activity. Stability of the radio-conjugate (at -4 deg. C and -80 deg. C) was determined over a period of more than 8 days. Maximum binding capacity (MBC) was found to be 23% for the species eluted at 25 min. Also MBC was lower for receptors obtained from AR 42J cells. 50% Inhibition dose was 9μg/mL (CV 20%). The

  10. Synthesis and biodistribution study of 3-iodo-4-hydroxyphenyl-cysteamine for detection of malignant melanoma based on specific enzyme of melanin formation

    International Nuclear Information System (INIS)

    Purpose: The aim of our study is to develop a new radiopharmaceutical labeled with radioiodine for detection and therapy of tumors, which have affinity to a characteristic metabolism in tumor. 3-Iodo-4-hydroxyphenyl-L-cysteine (I- L-PC), which we have reported previously, was found to have an interaction for tyrosinase, an essential and rate-limiting enzyme to melanin biosynthesis. In this study, considering higher affinity for tyrosinase, we synthesized 3-iodo-4-hydroxyphenylcysteamine (I-PCA) that was an amine derivative of I-L-PC and examined biodistribution study in melanoma-bearing mice. Method/Materials: 4-Hydroxyphenylcysteamine (4-PCA) was synthesized and radioiodinated in our laboratory. Synthesis of 4-PCA was confirmed by 1H-NMR, mass spectrometry and elemental analysis. 125I-PCA was prepared by conventional chloramine-T method under a no-carrier added condition. 125I-PCA was purified by Sep-Pak-C-18 cartridge and the labeling efficiency and radiochemical purity were examined by TLC analysis. Biodistribution study of I-PCA was performed using B16 melanoma-bearing C57BL6 mice. The radioactivities of each organ were measured and % injected dose / g wet tissue was determined. Moreover, the tumor-to-blood ratio (T/B ratio) and tumor-to-muscle ratios (T/M ratio) of 125I-PCA were also evaluated and were compared with 125I-L-PC, 67Ga-citrate, 125I-L-AMT and 123I-MIBG. Results: Radiosynthesis of 125I-PCA was carried out conveniently and efficiently within only 15 min. A labeling efficiency of more than 73 % resulted in the labeling of 4-PCA to 125I-PCA. After the simple Sep-Pak purification, no-carrier added 125I-PCA with radiochemical purity greater than 90 % was obtained. The biodistribution of 125I-PCA showed rapid blood clearance, renal excretion and low accumulation in normal tissue, while increase of accumulation in the tumor for 30 min. As a consequence, T/B ratio reached approximately 1.6 ± 0.3 and T/M ratio increased up to 8.7 ± 3.2 at 60 min after

  11. Comparative biodistribution profile of [131I]VIP and [131I]VIP10-28

    Directory of Open Access Journals (Sweden)

    Maria Tereza Colturato

    2005-10-01

    Full Text Available Various tumor cells express significantly higher amounts of VIP receptors (VIPR that provided the basis for the clinical use of radiolabeled VIP for the in vivo localization of tumors. This work studied the labeling of VIP and VIP10-28 with iodine-131 to compare the biological distribution of the labeled compounds in Nuce mice and the affinity for tumor cells. Both VIP and VIP10-28 peptides contain two tyrosine residues, in positions 10 and 22, that are theoretically equally susceptible to radioiodination employing oxidative electrophilic substitution using oxidizing agents like Chloramine T. Radiochemical purity of the reaction mixture was determined by electrophoresis and HPLC. The VIP peptide and the fragment were labeled with radioiodine with good radiochemical yield (above 96%. Suitable, but important differences can be observed in biological distribution studies. Comparatively, blood clearance was faster for labeled VIP and perhaps because of this, the uptake in tumor was lower, especially during the first hour. These differences observed in the biological distribution of the compounds can be related to the lipophilicity of the labeled compounds.Várias células tumorais expressam significantemente uma alta quantidade de receptores VIP (VIPR que determinam a base para o uso clínico de VIP radiomarcado para localização de tumores in vivo. Foi estudado neste trabalho a marcação do VIP e do fragmento VIP10-28 com iodo-131 comparando a distribuição biológica dos compostos marcados em camundongos Nude e sua afinidade pelas células tumorais. Ambos os peptídeos, VIP e VIP10-28. contém dois resíduos de tirosina nas posições 10 e 22, que teoricamente são igualmente susceptíveis pela substituição eletrofílica oxidativa do radioiodo utilizando Cloramina T como agente oxidante. A pureza radioquímica da mistura de reação foi determinada por eletroforese e cromatografia líquida de alta eficiência (CLAE. O VIP e fragmento foram

  12. I-131 rituximab (chimeric anti Cd 20 mab) radioimmunotherapy of non-Hodgkins lymphoma

    International Nuclear Information System (INIS)

    Full text: Commercially available anti-CD 20 monoclonal antibody, rituximab (MabThera) may be efficiently radioiodinated with 131I using standard Chloramine-T methodology in a hospital radiopharmacy, under appropriate regulatory authority approvals. Multicentre clinical trials of 131I-rituximab radioimmunotherapy have been performed in patients with relapsed or refractory low grade non-Hodgkins lymphoma with therapeutically effective administered activities being determined on the basis of individualised prospective patient dosimetry. A non-myeloablative regimen of 131I-radioimmunotherapy predicated upon a maximum prescribed dose of 0.75 Gy to whole body has been used to minimise myelotoxicity in patients undergoing radioimmunotherapy, even when they have been heavily pre-treated with chemotherapy and/or there is tumour infiltration of bone marrow greater than 25%. Provided that baseline leucocytes exceeded an absolute neutrophil count of 1.5 x 109/L and platelets > 100 x 109 /L, the incidence of grade IV haematological toxicity was 16% for neutrophils and 4 % for platelets which was self-limited. The red marrow radiation absorbed dose in selected patients receiving 131I activities estimated to deliver 0.75 Gy to whole body was calculated to be less than 2 Gy using Monte Carlo methodology on post therapy CT/SPECT imaging. Predictive dosimetry was performed by serial whole body imaging following IV administration of a standard 200 MBq 131I-rituximab tracer and determination of individual pharmacokinetics of the radiolabelled antibody in each patient. A standard dose of 375 mg/m2 unlabelled rituximab (MabThera) was administered IV immediately prior to the tracer and therapy doses of 131I-rituximab to minimise nonspecific uptake of the radiolabelled antibody and to optimise the tumour to background activity. The administration of a standard course of 4 cycles of cold rituximab (MabThera) in association with the prescribed maximum activity of 131I-rituximab constitutes

  13. Labelling and biological valuation of anti-CD-20 for treatment of non-Hodgkin's lymphoma

    International Nuclear Information System (INIS)

    Full text: Anti-CD20 monoclonal chimeric humanized murine antibodies (Rituximab), have been successfully applied for the treatment of Non Hodgkin's Lymphoma. However, upon labelling of the mab-CD20 with β-emitters as 90Y, the therapeutic efficacy has significantly increased due to radiological effects of ionizing radiation. Our objective was to develop reliable and efficient methods for labelling anti-CD20 with β-emitters of therapeutic interest and simple and rugged quality control methods to evaluate radiochemical purity, biological performance and immunoreactivity assessment. 131I and 188Re have been used for the labelling of anti-CD20 as two attractive alternatives due to decay properties and availability (188Re: Eβmax: 2.2MeV, Eγ 0,155MeV, T=17h, generator produced; 131I: Eβmax: 0,63MeV, Eγ 0,364MeV, T=8d). Labelling of anti-CD20 was optimized following the oxidation procedure of chloramine-T in the case of 131I and the synthesis of 188Re(IV) complex with the previously reduced monoclonal antibody. Quality control of the species obtained were done by physicochemical methods, including ITLC-SG and HPLC, non specific protein precipitation, biological distribution in normal mice and immunoreactivity studies with membrane antigens extracted from isolated leucocytes. 131I- (more than 3.7 GBq/mL) was introduced on tyrosyl residues of the protein chain by adding 28 MBq to 20μg of anti CD20 (Mab Thera, 10mg/mL) at pH 7.4 and 1.3μg of Choramine-T. Purification was done by gel-permeation with sephadex G-25 (PD-10, Pharmacia). For labelling with 188Re, anti CD20 was first reduced by incubation with 2- mercaptoethanol and purified over a PD10 column. Fractions of reduced antibody were pooled and formulated as kit for instant labelling. Each kit contained 1mg anti-CD20; 82.8mg of sodium tartrate; 1.67 mg of stannous fluoride and 0.25 mg gentisic acid. For the labelling, sodium perrhenate (1.5-1.9 GBq) was acidified, added to the kit and then incubated for 1 hour at

  14. Utilização do dióxido de cloro e do ácido peracético como substitutos do hipoclorito de sódio na sanitização do cheiro-verde minimamente processado Using chlorine dioxide and peracetic acid as substitutes for sodium hypocloride in the sanitization of minimally processed green seasoning

    Directory of Open Access Journals (Sweden)

    Silvana Mariana Srebernich

    2007-12-01

    propiciaram melhores resultados no controle microbiano. Entretanto, de acordo com os padrões existentes na legislação em vigor para Salmonella (ausência em 25 g de amostra e para E. coli (Minimally processed vegetables are ready to eat products that should be free of pathogenic microorganisms. These vegetables must be washed in good quality water, followed by the addition of a sanitizer to reduce the microbial count and minimize the product's deterioration, increasing its preservation and making it microbiologically safer. Sodium hypochlorite is the only sanitizer for this purpose allowed by Brazilian legislation. Although efficient, its use has been questioned because it is a precursor of organic chloramines, compounds of high carcinogenic potential. Many sanitizers have been proposed as substitutes of sodium hypochlorite in the disinfection of vegetables, including chlorine dioxide and peracetic acid. Therefore, based on microbial analyses, this research aimed to test the efficiency of chlorine dioxide (10, 25 and 50 ppm /2, 5 and 10 minutes and peracetic acid (60, 80 and 100 ppm/5, 10 and 15 minutes in comparison with sodium hypochlorite (120 ppm/15 minutes in the control of natural microbiota of minimally processed green seasoning. The green seasoning, which consists of fresh parsley and welsh onions, was washed in various concentrations of sanitizing solutions for given times and then processed to obtain sample of green seasoning. The control sample was washed only in tap water. The treatments were repeated on 3 distinct occasions at 4-month intervals, and 3 samples (packages of 150 g were collected from each treatment for microbial analysis of pathogenic Salmonella sp., total coliforms, Escherichia coli and total fungal count. The results of these analyses after statistical evaluation indicated that higher concentrations and longer sanitizing treatments led to better microbial control. However, according to the standards in the current legislation on Salmonella sp

  15. Preclinical study of radioiodinated glucose-Tyr3-octreotate: Comparison with 111In-DOTA-Tyr3-octreotate

    International Nuclear Information System (INIS)

    Full text: Targeted radionuclide imaging and treatment are based upon the interaction of radioligands with receptors in the target tissue (namely high density receptor specific tumours). As receptors for somatostatin (mainly somatostatin receptor subtype-2 /sstr2/) are over-expressed in several human tumours of endocrine origin, a number of radiolabeled somatostatin analogs have been recently introduced as the vectors for targeted imaging and therapy; commercially available 111In-DTPA-octreotide being a gold standard in this field. Several publications demonstrate that a substitution of Tyr instead of Phe in the peptide position 3 and oxidation of carboxyl end of octreotide significantly increased the affinity of the peptide to sstr2. More recently it has been shown that NH2-terminal carbohydration leads to a further improvement of the peptide receptor affinity and its retention in the tumour. In this study we present preclinical analysis of distribution profile and elimination pathways of radioiodinated glucose-Tyr3-octreotate (125I-gluc-TOCA) in comparison with that of another promising targeted radiopharmaceutical, namely 111In-DOTA-Tyr3-octreotate (111In- DOTA-TOCA). Gluc-TOCA was radioiodinated using chloramine-T method. For radiolabeling of DOTA-TOCA with radiometal, to 200 μl of 0.4 M acetate buffer with 0.24 M gentisic acid pH 5, 10μl of peptide solution in 0.1% TFA (1mg/ml) were added together with 0.5-1 mCi of 111InCl3 in 0.04 M HCl. Reaction mixture was heated 25 minutes to 90-95 deg. C. Pharmacokinetic studies were performed on male Wistar rats. Results confirmed that specific internalization of 125I-gluc-TOCA by sstr2 - expressing AR423 rat pancreatic carcinoma cells in vitro was about twice of that for 111In-DOTA-TOCA. In rats, 125I-gluc-TOCA exhibited prolonged plasma clearance in comparison with the other peptide. Slower decrease of plasma radioactivity after 125I-gluc-TOCA was due to its higher lipophilicity and thus higher plasma protein binding

  16. Effect of cardiac muscle collagen and actin on myocardiopathological change of diabetes mellitus%心肌胶原蛋白和肌动蛋白对糖尿病心肌病变的研究

    Institute of Scientific and Technical Information of China (English)

    吴伟; 张锦; 邱阳

    2005-01-01

    目的研究糖尿病大鼠不同病程心肌胶原蛋白和骨架蛋白含量的变化,阐明两者对糖尿病心肌病变发生的作用.方法制造糖尿病大鼠心肌模型随机分组.氯胺T法测定羟脯氨酸含量,代表心肌胶原总含量.心肌免疫组织化学染色测定心肌胶原蛋白(Collagen Ⅰ、Collagen Ⅲ)和心肌型α肌动蛋白(α-actin)及转化生长因子β1(TGF-β1)平均积分光密度(IOD).心肌病理改变的光镜和透射电镜观察.结果糖尿病痛程6个月组心肌胶原总含量明显高于病程3个月以内组(P<0.01).病程3个月之后Ⅰ型胶原蛋白表达伴随TGF-β1的表达开始较健康鼠明显增加(P<0.01).α-actin蛋白表达较健康鼠明显减少(P<O.01).糖尿病鼠心肌横切面可见粗大胶原纤维相互连接成网状,排列紊乱,分布不匀.心肌细胞心肌型α-actin蛋白分布不均匀,着色呈浅黄色,心肌纵切面可见α-actin蛋白表达主要分布于心肌肌膜处.病程3个月后大鼠心肌细胞核皱缩,线粒体肿胀、模糊,闰盘不连续,α-actin蛋白表达明显减少,有糖原沉积现象.结论Ⅰ型心肌胶原蛋白呈现持续性增加是糖尿病鼠心肌纤维化的主要原因.心肌细胞核皱缩,线粒体肿胀、模糊,闰盘不连续,糖原沉积和心肌型actin表达减少是糖尿病心肌病病理基础.%[Objective] To investigate the content changes of myocardial collagenprotein and actin at different stages of diabetes mellitus(DM) rats. So as to illustrate that they play a role in myocardial changes of DM. [Methods] Cardiac muscle model of DM rats was grouped randomly. The hydroxy proline contents were measured with the chloramine T method. The type Ⅰ collagen, type Ⅲ collagen,transforming factor beta1 (TGF-beta1) and cardiactype α-actin were determined by myocardial immunehistochemical stain. Myocardiopathological change were observed with light microscope and transmission electron microscope. [Results] The collagen contents

  17. DOTA-TATE alternative labellings with halogens and radiometals

    International Nuclear Information System (INIS)

    Full text: DOTA-D-phe-cys-tyr-D-trp-lys-thr-cys-thr (DOTA-TATE), a somatostatin analog with high affinity for somatostatin receptors expressed in cancer of neuroendocrine origin, may be labeled with different beta radionuclides for its use in targeted radiotherapy. This allows the obtanting of products with particular chemical, radiochemical and biological properties, which interact in specific way with cells that express somatostatin receptors. In this study the labelling of DOTA-TATE with 125I, 131I and 177Lu and their biological properties were investigated, with the aim of potential application as a tumour seeking agents. Radioiodine was introduced on the tyrosyl residue of the DOTA-TATE by oxidation of iodide with chloramine-T. The labeled peptide was isolated from the reaction mixture by sep-pak purification and/or by RP-HPLC. Lutetium-177 was introduced in the peptide via the DOTA ring. To 7,2μg of DOTA-TATE 1mg/mL, 2μL 177LuCl3 (7.2 mCi) and 7.2 μL of gentisic acid in CH3COONa 0.4M were added. The mixture was incubated 30 minutes at 100 deg. C. Purification by RP-HPLC was conducted on a C18 column eluted with a linear gradient from 10% to 40% B in 30 min (A: 0.1% TFA in water and B: 0.1% TFA in acetonitrile). Fractions containing the labeled peptide were pooled and most of the solvent removed by evaporation and re-suspended in 1 mL of saline. For the control of 131I-DOTA-TATE, different gradients were used in order to optimize the separation. In the case of 177Lu-DOTA-TATE analysis, gradient was from 5 to 95% B in 15 minutes. Stability at different time intervals was evaluated by RP-HPLC and by chromatography in ITLC-SG or Whatman 3MM using different mobile phases: 2-butanone (MEK); NaCl 0.9%; EtOH-HCl 0.01N 90:10 and butanol:acetic:H2O (4:1:5) for radioidinated peptides. For 177Lu-DOTA-TATE, the chromatographic systems were: CH3COONH4 10%/MeOH (30:70), BuOH-CH3COOH-H2O (5:2:1), TFA 0,1% in ACN- H2O (1:1) and Sodium citrate 0.1M, pH:5 in Whatman 3MM (Rf

  18. 益气养阴、活血化瘀中药对糖尿病大鼠脂代谢紊乱及蛋白质非酶糖基化的影响%Effect of Chinese herb for benefiting qi, nourishing yin, activating blood circulation and resolving stasis on lipid metabolic disturbance and protein nonenzyme glycosylation in diabetic rats

    Institute of Scientific and Technical Information of China (English)

    戴红

    2005-01-01

    administered once every day in above 6 groups,and the treating course was 8 weeks. ③ Before treatment, on the 3rd, 6th and 8th weeks after treatment, fasting blood sugar was tested with One Touch Ⅱ tester. 8 weeks later, automatic biochemistry analyzer was used to assay triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDLC) and high-density lipoprotein cholesterol (HDLC). Thoracic aorta was collected swiftly and chloramine-T method was used to assay hydroxyproline content in the extract from aorta. Hydroxyproline content ×7.14=collagen content. Fluorescence spectrometer was used to assay the fluorescence degree of AGEs in collagen extract. ④ t test was applied for difference comparison of measurement data.MAIN OUTCOME MEASURES: ① Comparison of fasting blood sugar before and after treatment in each group. ② Comparison of blood lipid,collagen content and fluorescence degree of collagen-protein AGEs in thoracic aorta in 8 weeks after treatment in each group.RESULTS: At the end of experiment, 8, 4, 2, 2 and 3 rats were died in model group, insulin group, HXY low, middle and high-dose groups respectively, due to which, 12, 8, 11, 13, 13 and 12 rats entered result analysis in various groups respectively. ① Fasting blood sugar: Before treatment, it was higher remarkably in model and various treating groups compared with normal control (P < 0.01) and 8 weeks after treatment, it was lower remarkably in insulin group and various HXY groups compared with model group and before treatment (P < 0.01). ② Levels of TC, TG, LDLC in serum: Those in insulin and model groups were higher remarkably than normal control (P < 0.05-0.01). Those in insulin group and various HXY groups were lower remarkably than normal group (P < 0.05-0.01). ③ Level of HDLC: It was lower remarkably in insulin group and model group compared with normal control (P < 0.05-0.01), it was higher remarkably in HXY low and middle-dose groups compared with model group (P