The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
J E Parkin - One of the best experts on this subject based on the ideXlab platform.
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route of decomposition of Thiomersal thimerosal
International Journal of Pharmaceutics, 2000Co-Authors: M Tan, J E ParkinAbstract:The route of formation and identification of the principal degradation products of thimerosal (Thiomersal) has been undertaken. The initial oxidation to dithiosalicylic acid is followed by cleavage of the disulphide bond of the dithiosalicylic acid by the ethylmercuric ion to reform 1.5 mol of thimerosal with concurrent oxidation to form 0.5 mol of 2-sulfinobenzoic acid for each mole of dithiosalicylic acid. In the presence of copper ions 2-sulfobenzoic acid was also formed. A mechanism has been proposed which accounts for the stoichiometry of the cleavage reaction observed and the significance of the reaction is discussed.
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the effect of disodium edetate and sodium chloride on the stability of ethylmercury arising from the decomposition of thimerosal Thiomersal
Drug Development and Industrial Pharmacy, 1995Co-Authors: Faridah Mcdonald, J E ParkinAbstract:The effect of disodium edetate and sodium chloride on the stability of the ethylmercuric ion arising from the decomposition of thiomerosal has been investigated using species-specific chromatographic assays. Disodium edetate stabilises both the ethylmercuric ion and thimerosal whereas chloride stabilises the ethylmercuric ion but promotes decomposition of the thimerosal.
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assay for Thiomersal thimerosal with adaptation to the quantitation of total ethylmercury available in degraded samples
Journal of Chromatography A, 1991Co-Authors: J E ParkinAbstract:Abstract A simple adaptation of a previously reported chromatographic procedure for Thiomersal (thimerosal) is reported. This involves the sequential analysis of a degraded sample of Thiomersal with and without the addition of excess thiosalicylic acid. This enables the total amount of available ethylmercuric ion and Thiomersal to be quantitated and by difference the amount of free ethylmercuric ion. The antimicrobial significance of the results is briefly discussed.
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high performance liquid chromatographic assay of Thiomersal thimerosal as the ethylmercury dithiocarbamate complex
Journal of Chromatography A, 1991Co-Authors: J E ParkinAbstract:Abstract A high-performance liquid chromatographic (HPLC) assay has been developed for the ethyimercury ligand of Thiomersal (thimerosal) as either the morpholine or piperidinedithiocarbamate complexes. The assay has been compared with a previously reported HPLC assay of Thiomersal for organomercurical degraded both thermally and photochemically, and significant differences are noted.
Michael Young - One of the best experts on this subject based on the ideXlab platform.
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Thiomersal enhances the binding of histamine to the h1 receptor but not histamine stimulated inositol phosphate formation
Journal of Pharmacy and Pharmacology, 2010Co-Authors: Vandana Jain, Emma Mcwilliams, Michael YoungAbstract:Thiomersal (thimerosal) was a weak inhibitor of the binding of [(3)H]mepyramine to histamine H(1) receptors in guinea-pig cerebellar membranes (11 +/- 1% inhibition at 10 microM, 32 +/- 3% inhibition at 300 microM). However, in the concentration range 3-30 microM, Thiomersal enhanced the binding of histamine to the H(1) receptor, as reflected by the displacement of curves of histamine inhibition of [(3)H]mepyramine binding to lower concentrations, without any change in the Hill coefficient. The ratio of the IC50 values (the concentration giving 50% inhibition) in the absence and presence of Thiomersal increased from 1.8 with 3 microM to 3.6 with 30 microM Thiomersal. There was no consistent effect of Thiomersal at concentrations of 30 microM and below on curves of mepyramine inhibition of [(3)H]mepyramine binding. In the presence of 10 microM Thiomersal histamine-induced accumulation of inositol phosphates in U373 MG astrocytoma cells was partially inhibited (37 +/- 8% inhibition of the maximum response), without any significant change in the EC50 (the concentration giving the half maximal response) for histamine. Thus although histamine binding was potentiated by Thiomersal, there was no potentiation of an H(1) receptor-mediated functional response.
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Thiomersal enhances the binding of histamine to the h1 receptor but not histamine stimulated inositol phosphate formation
Journal of Pharmacy and Pharmacology, 2003Co-Authors: Vandana Jain, Emma Mcwilliams, Michael YoungAbstract:: Thiomersal (thimerosal) was a weak inhibitor of the binding of [(3)H]mepyramine to histamine H(1) receptors in guinea-pig cerebellar membranes (11 +/- 1% inhibition at 10 microM, 32 +/- 3% inhibition at 300 microM). However, in the concentration range 3-30 microM, Thiomersal enhanced the binding of histamine to the H(1) receptor, as reflected by the displacement of curves of histamine inhibition of [(3)H]mepyramine binding to lower concentrations, without any change in the Hill coefficient. The ratio of the IC50 values (the concentration giving 50% inhibition) in the absence and presence of Thiomersal increased from 1.8 with 3 microM to 3.6 with 30 microM Thiomersal. There was no consistent effect of Thiomersal at concentrations of 30 microM and below on curves of mepyramine inhibition of [(3)H]mepyramine binding. In the presence of 10 microM Thiomersal histamine-induced accumulation of inositol phosphates in U373 MG astrocytoma cells was partially inhibited (37 +/- 8% inhibition of the maximum response), without any significant change in the EC50 (the concentration giving the half maximal response) for histamine. Thus although histamine binding was potentiated by Thiomersal, there was no potentiation of an H(1) receptor-mediated functional response.
Vandana Jain - One of the best experts on this subject based on the ideXlab platform.
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Thiomersal enhances the binding of histamine to the h1 receptor but not histamine stimulated inositol phosphate formation
Journal of Pharmacy and Pharmacology, 2010Co-Authors: Vandana Jain, Emma Mcwilliams, Michael YoungAbstract:Thiomersal (thimerosal) was a weak inhibitor of the binding of [(3)H]mepyramine to histamine H(1) receptors in guinea-pig cerebellar membranes (11 +/- 1% inhibition at 10 microM, 32 +/- 3% inhibition at 300 microM). However, in the concentration range 3-30 microM, Thiomersal enhanced the binding of histamine to the H(1) receptor, as reflected by the displacement of curves of histamine inhibition of [(3)H]mepyramine binding to lower concentrations, without any change in the Hill coefficient. The ratio of the IC50 values (the concentration giving 50% inhibition) in the absence and presence of Thiomersal increased from 1.8 with 3 microM to 3.6 with 30 microM Thiomersal. There was no consistent effect of Thiomersal at concentrations of 30 microM and below on curves of mepyramine inhibition of [(3)H]mepyramine binding. In the presence of 10 microM Thiomersal histamine-induced accumulation of inositol phosphates in U373 MG astrocytoma cells was partially inhibited (37 +/- 8% inhibition of the maximum response), without any significant change in the EC50 (the concentration giving the half maximal response) for histamine. Thus although histamine binding was potentiated by Thiomersal, there was no potentiation of an H(1) receptor-mediated functional response.
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Thiomersal enhances the binding of histamine to the h1 receptor but not histamine stimulated inositol phosphate formation
Journal of Pharmacy and Pharmacology, 2003Co-Authors: Vandana Jain, Emma Mcwilliams, Michael YoungAbstract:: Thiomersal (thimerosal) was a weak inhibitor of the binding of [(3)H]mepyramine to histamine H(1) receptors in guinea-pig cerebellar membranes (11 +/- 1% inhibition at 10 microM, 32 +/- 3% inhibition at 300 microM). However, in the concentration range 3-30 microM, Thiomersal enhanced the binding of histamine to the H(1) receptor, as reflected by the displacement of curves of histamine inhibition of [(3)H]mepyramine binding to lower concentrations, without any change in the Hill coefficient. The ratio of the IC50 values (the concentration giving 50% inhibition) in the absence and presence of Thiomersal increased from 1.8 with 3 microM to 3.6 with 30 microM Thiomersal. There was no consistent effect of Thiomersal at concentrations of 30 microM and below on curves of mepyramine inhibition of [(3)H]mepyramine binding. In the presence of 10 microM Thiomersal histamine-induced accumulation of inositol phosphates in U373 MG astrocytoma cells was partially inhibited (37 +/- 8% inhibition of the maximum response), without any significant change in the EC50 (the concentration giving the half maximal response) for histamine. Thus although histamine binding was potentiated by Thiomersal, there was no potentiation of an H(1) receptor-mediated functional response.
R. J. Pinney - One of the best experts on this subject based on the ideXlab platform.
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survival of plasmid containing strains of escherichia coli pseudomonas aeruginosa and staphylococcus aureus in phenylmercuric nitrate and Thiomersal
Journal of Pharmacy and Pharmacology, 2011Co-Authors: R. J. PinneyAbstract:Strains of Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus harbouring plasmids that confer mercury resistance grew in nutrient broth containing concentrations of phenylmercuric nitrate (PMN) that were inhibitory to isogenic plasmid-less strains. Decimal reduction times of P. aeruginosa and S. aureus in aqueous PMN solution were also increased by the presence of plasmids. The viable count of a plasmid-containing P. aeruginosa strain in Davis and Mingioli's minimal medium (DM) containing 10 microgram ml-1 PMN fell by approximately 99% after 5 h. The count then remained constant for two weeks, when growth recommenced. This pattern of death followed by growth was also observed with the P. aeruginosa strain in DM + 10 microgram ml-1 Thiomersal.
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Epidemiology and susceptibilities to mercury preservatives of staphylococci isolated from used eye-drops preserved with Thiomersal.
The Journal of pharmacy and pharmacology, 1995Co-Authors: S. K. Du Bois, A. L. Davison, R. J. PinneyAbstract:Minimum inhibitory concentrations (MICs) of seven independent isolates of Staphylococcus hominis isolated in the same week from used eye-drops, preserved with Thiomersal and collected from wards and clinics in the same hospital, ranged between 1 and 0·03 mg L−1 for Thiomersal, 1 and 0·01 mg L−1 for phenyl mercuric nitrate and 10 and 3 mg L−1 for mercuric chloride. Although MIC values determined on solid nutrient medium indicated a 100-fold variation in susceptibility to the bacteriostatic effect of phenyl mercuric nitrate, after 5 h in an aqueous solution containing the bactericidal concentration of 10 mg L−1 phenyl mercuric nitrate, the survival levels of the six S. hominis isolates were similar, with a mean of 13·4% (s.d. 11·0), compared with 100 and 0·8%, respectively, for the most resistant and most sensitive control staphylococcal strains tested. Antibiotic susceptibilities and plasmid profiles of the S. hominis isolates indicated they were the same strain. It is concluded that laboratory indicators of preservative efficacy, such as MIC determination or susceptibility to bactericidal concentrations of preservatives, do not necessarily correlate with the epidemiology of contaminating bacterial strains or their survival in preserved pharmaceuticals.
Emma Mcwilliams - One of the best experts on this subject based on the ideXlab platform.
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Thiomersal enhances the binding of histamine to the h1 receptor but not histamine stimulated inositol phosphate formation
Journal of Pharmacy and Pharmacology, 2010Co-Authors: Vandana Jain, Emma Mcwilliams, Michael YoungAbstract:Thiomersal (thimerosal) was a weak inhibitor of the binding of [(3)H]mepyramine to histamine H(1) receptors in guinea-pig cerebellar membranes (11 +/- 1% inhibition at 10 microM, 32 +/- 3% inhibition at 300 microM). However, in the concentration range 3-30 microM, Thiomersal enhanced the binding of histamine to the H(1) receptor, as reflected by the displacement of curves of histamine inhibition of [(3)H]mepyramine binding to lower concentrations, without any change in the Hill coefficient. The ratio of the IC50 values (the concentration giving 50% inhibition) in the absence and presence of Thiomersal increased from 1.8 with 3 microM to 3.6 with 30 microM Thiomersal. There was no consistent effect of Thiomersal at concentrations of 30 microM and below on curves of mepyramine inhibition of [(3)H]mepyramine binding. In the presence of 10 microM Thiomersal histamine-induced accumulation of inositol phosphates in U373 MG astrocytoma cells was partially inhibited (37 +/- 8% inhibition of the maximum response), without any significant change in the EC50 (the concentration giving the half maximal response) for histamine. Thus although histamine binding was potentiated by Thiomersal, there was no potentiation of an H(1) receptor-mediated functional response.
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Thiomersal enhances the binding of histamine to the h1 receptor but not histamine stimulated inositol phosphate formation
Journal of Pharmacy and Pharmacology, 2003Co-Authors: Vandana Jain, Emma Mcwilliams, Michael YoungAbstract:: Thiomersal (thimerosal) was a weak inhibitor of the binding of [(3)H]mepyramine to histamine H(1) receptors in guinea-pig cerebellar membranes (11 +/- 1% inhibition at 10 microM, 32 +/- 3% inhibition at 300 microM). However, in the concentration range 3-30 microM, Thiomersal enhanced the binding of histamine to the H(1) receptor, as reflected by the displacement of curves of histamine inhibition of [(3)H]mepyramine binding to lower concentrations, without any change in the Hill coefficient. The ratio of the IC50 values (the concentration giving 50% inhibition) in the absence and presence of Thiomersal increased from 1.8 with 3 microM to 3.6 with 30 microM Thiomersal. There was no consistent effect of Thiomersal at concentrations of 30 microM and below on curves of mepyramine inhibition of [(3)H]mepyramine binding. In the presence of 10 microM Thiomersal histamine-induced accumulation of inositol phosphates in U373 MG astrocytoma cells was partially inhibited (37 +/- 8% inhibition of the maximum response), without any significant change in the EC50 (the concentration giving the half maximal response) for histamine. Thus although histamine binding was potentiated by Thiomersal, there was no potentiation of an H(1) receptor-mediated functional response.
