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Roy E. Pounder - One of the best experts on this subject based on the ideXlab platform.
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Transmucosal penetration of Bismuth particles in the human stomach
Gastroenterology, 2016Co-Authors: Chuka U. Nwokolo, J Lewin, M. Hudson, Roy E. PounderAbstract:Abstract Electron microscopic examination of upper gastrointestinal biopsies with x-ray microanalysis was used to detect electron-dense particles of Bismuth in the mucosa of the upper gastrointestinal tract, 30–60 minutes after oral dosing with either tripotassium dicitrato Bismuthate [De-Noltab; Brocades (Great Britain) Ltd., Weybridge, UK; five patients] or Bismuth salicylate (Pepto-Bismol; Richardson Vicks Ltd., Egham, UK; five patients), or without dosing (two patients). Transmucosal penetration of Bismuth particles was observed in the gastric antral mucosa of all patients who had been dosed with tripotassium dicitrato Bismuthate, but there was no penetration after oral dosing with Bismuth salicylate. Persorption of Bismuth particles through the gastric mucosa to the vascular endothelium provides an explanation for the rapid rise of plasma Bismuth concentration observed only after oral dosing with tripotassium dicitrato Bismuthate.
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Bismuth accumulates in the body during treatment with tripotassium dicitrato Bismuthate
Alimentary Pharmacology & Therapeutics, 2007Co-Authors: C J Gavey, M L Szeto, J Sercombe, Chuka U. Nwokolo, Roy E. PounderAbstract:: Bismuth concentration was measured in plasma, dried leucocytes and urine in nine patients before, during and after treatment with tripotassium dicitrato Bismuthate (De-Noltab 2 b.d.) for 6 weeks. During treatment there was an 8.5-fold rise in median plasma Bismuth concentration (P less than 0.01), a non-significant doubling of leucocyte Bismuth content, and a 349-fold rise in 24-h urinary Bismuth excretion (P less than 0.01). The significantly increased urinary Bismuth excretion continued for at least 3 months after cessation of treatment with tripotassium dicitrato Bismuthate, indicating accumulation of Bismuth during treatment with this drug.
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the absorption of Bismuth and salicylate from oral doses of pepto bismol Bismuth salicylate
Alimentary Pharmacology & Therapeutics, 2007Co-Authors: Chuka U. Nwokolo, P Mistry, Roy E. PounderAbstract:SUMMARY Plasma Bismuth and plasma salicylate concentrations were measured before and after three 30-ml oral doses of Bismuth salicylate (Pepto-Bismol liquid) in 10 fasting healthy subjects. From 0 to 120 min following the first dose of Bismuth salicylate, the plasma Bismuth concentration was less than 1 ng/ml. The peak median plasma Bismuth concentration was at + 240 min (1.7 ng/ml; range 0.8–5.3 ng/ml). Salicylate appeared in the plasma of all subjects at + 30 min, and it reached a peak at + 120 min (median 61 mg/L; range 46–104 mg/L). The study demonstrates that, despite rapid and substantial absorption of salicylate, there is negligible absorption of Bismuth into the bloodstream from standard oral doses of Bismuth salicylate.
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the absorption of Bismuth from oral doses of tripotassium dicitrato Bismuthate
Alimentary Pharmacology & Therapeutics, 2007Co-Authors: Chuka U. Nwokolo, C J Gavey, J T L Smith, Roy E. PounderAbstract:SUMMARY Two studies measured plasma concentrations of Bismuth during dosing with tripotassium dicitrato Bismuthate (De-Noltab). The first study compared 24 h plasma Bismuth concentration and urinary Bismuth excretion in six patients who had already received 29–131 days (median 47 days) of treatment with De-Noltab 2 b.d., and six healthy subjects who only received De-Noltab 2 b.d. on the day of study. There was a prompt rise in plasma Bismuth concentration after each dose of De-Noltabs. The median 24 h integrated plasma Bismuth concentration was similar in both groups, but the median 24 h urinary Bismuth excretion was 5.4-fold higher in the patients. The second study compared the plasma Bismuth concentrations after the first and third doses of De-Noltab 2 b.d. in 16 healthy subjects. The median peak Bismuth concentration occurred 30 min (range 15–105 min) post-dosing. The peak plasma Bismuth concentration was greater than 50 ng/ml in 14 of the 16 subjects, and greater than 100 ng/ml in nine of the subjects. There was no significant difference in the median integrated 10-h plasma Bismuth concentration after the first or third dose of De-Noltabs. The results of these studies confirm that Bismuth is absorbed and sequestrated during dosing with De-Noltabs. Bismuth is absorbed rapidly after oral dosing with De-NoItabs, to produce peak plasma Bismuth concentrations hitherto considered to be in the range associated with Bismuth neurotoxicity.
Pierre Yves Robidoux - One of the best experts on this subject based on the ideXlab platform.
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bioavailability and chronic toxicity of Bismuth citrate to earthworm eisenia andrei exposed to natural sandy soil
Ecotoxicology and Environmental Safety, 2018Co-Authors: Zohra Omouri, Pierre Yves Robidoux, Jalal Hawari, Michel FournierAbstract:Abstract The present study describes bioavailability and chronic effects of Bismuth to earthworms Eisenia andrei using OECD reproduction test. Adult earthworms were exposed to natural sandy soil contaminated artificially by Bismuth citrate. Average total concentrations of Bismuth in soil recovered by HNO3 digestion ranged from 75 to 289 mg/kg. Results indicate that Bismuth decreased significantly all reproduction parameters of Eisenia andrei at concentrations ≥ 116 mg/kg. However, number of hatched cocoons and number of juveniles seem to be more sensitive than total number of cocoons, as determined by IC50; i.e., 182, 123 and > 289 mg/kg, respectively. Bismuth did not affect Eisenia andrei growth and survival, and had little effect on phagocytic efficiency of coelomocytes. The low immunotoxicity effect might be explained by the involvement of other mechanisms i.e. Bismuth sequestered by metal-binding compounds. After 28 days of exposure Bismuth concentrations in earthworms tissue increased with increasing Bismuth concentrations in soil reaching a stationary state of 21.37 mg/kg dry tissue for 243 mg Bi/kg dry soil total content. Data indicate also that after 56 days of incubation the average fractions of Bismuth available extracted by KNO3 aqueous solution in soil without earthworms varied from 0.0051 to 0.0229 mg/kg, while in soil with earthworms Bismuth concentration ranged between 0.310–1.347 mg/kg dry soil. We presume that mucus and chelating agents produced by earthworms and by soil or/and earthworm gut microorganisms could explain this enhancement, as well as the role of dermal and ingestion routes of earthworms uptake to soil contaminant.
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bioavailability and chronic toxicity of Bismuth citrate to earthworm eisenia andrei exposed to natural sandy soil
Ecotoxicology and Environmental Safety, 2018Co-Authors: Zohra Omouri, Pierre Yves Robidoux, Jalal Hawari, Michel FournierAbstract:Abstract The present study describes bioavailability and chronic effects of Bismuth to earthworms Eisenia andrei using OECD reproduction test. Adult earthworms were exposed to natural sandy soil contaminated artificially by Bismuth citrate. Average total concentrations of Bismuth in soil recovered by HNO3 digestion ranged from 75 to 289 mg/kg. Results indicate that Bismuth decreased significantly all reproduction parameters of Eisenia andrei at concentrations ≥ 116 mg/kg. However, number of hatched cocoons and number of juveniles seem to be more sensitive than total number of cocoons, as determined by IC50; i.e., 182, 123 and > 289 mg/kg, respectively. Bismuth did not affect Eisenia andrei growth and survival, and had little effect on phagocytic efficiency of coelomocytes. The low immunotoxicity effect might be explained by the involvement of other mechanisms i.e. Bismuth sequestered by metal-binding compounds. After 28 days of exposure Bismuth concentrations in earthworms tissue increased with increasing Bismuth concentrations in soil reaching a stationary state of 21.37 mg/kg dry tissue for 243 mg Bi/kg dry soil total content. Data indicate also that after 56 days of incubation the average fractions of Bismuth available extracted by KNO3 aqueous solution in soil without earthworms varied from 0.0051 to 0.0229 mg/kg, while in soil with earthworms Bismuth concentration ranged between 0.310–1.347 mg/kg dry soil. We presume that mucus and chelating agents produced by earthworms and by soil or/and earthworm gut microorganisms could explain this enhancement, as well as the role of dermal and ingestion routes of earthworms uptake to soil contaminant.
Zohra Omouri - One of the best experts on this subject based on the ideXlab platform.
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bioavailability and chronic toxicity of Bismuth citrate to earthworm eisenia andrei exposed to natural sandy soil
Ecotoxicology and Environmental Safety, 2018Co-Authors: Zohra Omouri, Pierre Yves Robidoux, Jalal Hawari, Michel FournierAbstract:Abstract The present study describes bioavailability and chronic effects of Bismuth to earthworms Eisenia andrei using OECD reproduction test. Adult earthworms were exposed to natural sandy soil contaminated artificially by Bismuth citrate. Average total concentrations of Bismuth in soil recovered by HNO3 digestion ranged from 75 to 289 mg/kg. Results indicate that Bismuth decreased significantly all reproduction parameters of Eisenia andrei at concentrations ≥ 116 mg/kg. However, number of hatched cocoons and number of juveniles seem to be more sensitive than total number of cocoons, as determined by IC50; i.e., 182, 123 and > 289 mg/kg, respectively. Bismuth did not affect Eisenia andrei growth and survival, and had little effect on phagocytic efficiency of coelomocytes. The low immunotoxicity effect might be explained by the involvement of other mechanisms i.e. Bismuth sequestered by metal-binding compounds. After 28 days of exposure Bismuth concentrations in earthworms tissue increased with increasing Bismuth concentrations in soil reaching a stationary state of 21.37 mg/kg dry tissue for 243 mg Bi/kg dry soil total content. Data indicate also that after 56 days of incubation the average fractions of Bismuth available extracted by KNO3 aqueous solution in soil without earthworms varied from 0.0051 to 0.0229 mg/kg, while in soil with earthworms Bismuth concentration ranged between 0.310–1.347 mg/kg dry soil. We presume that mucus and chelating agents produced by earthworms and by soil or/and earthworm gut microorganisms could explain this enhancement, as well as the role of dermal and ingestion routes of earthworms uptake to soil contaminant.
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bioavailability and chronic toxicity of Bismuth citrate to earthworm eisenia andrei exposed to natural sandy soil
Ecotoxicology and Environmental Safety, 2018Co-Authors: Zohra Omouri, Pierre Yves Robidoux, Jalal Hawari, Michel FournierAbstract:Abstract The present study describes bioavailability and chronic effects of Bismuth to earthworms Eisenia andrei using OECD reproduction test. Adult earthworms were exposed to natural sandy soil contaminated artificially by Bismuth citrate. Average total concentrations of Bismuth in soil recovered by HNO3 digestion ranged from 75 to 289 mg/kg. Results indicate that Bismuth decreased significantly all reproduction parameters of Eisenia andrei at concentrations ≥ 116 mg/kg. However, number of hatched cocoons and number of juveniles seem to be more sensitive than total number of cocoons, as determined by IC50; i.e., 182, 123 and > 289 mg/kg, respectively. Bismuth did not affect Eisenia andrei growth and survival, and had little effect on phagocytic efficiency of coelomocytes. The low immunotoxicity effect might be explained by the involvement of other mechanisms i.e. Bismuth sequestered by metal-binding compounds. After 28 days of exposure Bismuth concentrations in earthworms tissue increased with increasing Bismuth concentrations in soil reaching a stationary state of 21.37 mg/kg dry tissue for 243 mg Bi/kg dry soil total content. Data indicate also that after 56 days of incubation the average fractions of Bismuth available extracted by KNO3 aqueous solution in soil without earthworms varied from 0.0051 to 0.0229 mg/kg, while in soil with earthworms Bismuth concentration ranged between 0.310–1.347 mg/kg dry soil. We presume that mucus and chelating agents produced by earthworms and by soil or/and earthworm gut microorganisms could explain this enhancement, as well as the role of dermal and ingestion routes of earthworms uptake to soil contaminant.
Chuka U. Nwokolo - One of the best experts on this subject based on the ideXlab platform.
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Transmucosal penetration of Bismuth particles in the human stomach
Gastroenterology, 2016Co-Authors: Chuka U. Nwokolo, J Lewin, M. Hudson, Roy E. PounderAbstract:Abstract Electron microscopic examination of upper gastrointestinal biopsies with x-ray microanalysis was used to detect electron-dense particles of Bismuth in the mucosa of the upper gastrointestinal tract, 30–60 minutes after oral dosing with either tripotassium dicitrato Bismuthate [De-Noltab; Brocades (Great Britain) Ltd., Weybridge, UK; five patients] or Bismuth salicylate (Pepto-Bismol; Richardson Vicks Ltd., Egham, UK; five patients), or without dosing (two patients). Transmucosal penetration of Bismuth particles was observed in the gastric antral mucosa of all patients who had been dosed with tripotassium dicitrato Bismuthate, but there was no penetration after oral dosing with Bismuth salicylate. Persorption of Bismuth particles through the gastric mucosa to the vascular endothelium provides an explanation for the rapid rise of plasma Bismuth concentration observed only after oral dosing with tripotassium dicitrato Bismuthate.
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Bismuth accumulates in the body during treatment with tripotassium dicitrato Bismuthate
Alimentary Pharmacology & Therapeutics, 2007Co-Authors: C J Gavey, M L Szeto, J Sercombe, Chuka U. Nwokolo, Roy E. PounderAbstract:: Bismuth concentration was measured in plasma, dried leucocytes and urine in nine patients before, during and after treatment with tripotassium dicitrato Bismuthate (De-Noltab 2 b.d.) for 6 weeks. During treatment there was an 8.5-fold rise in median plasma Bismuth concentration (P less than 0.01), a non-significant doubling of leucocyte Bismuth content, and a 349-fold rise in 24-h urinary Bismuth excretion (P less than 0.01). The significantly increased urinary Bismuth excretion continued for at least 3 months after cessation of treatment with tripotassium dicitrato Bismuthate, indicating accumulation of Bismuth during treatment with this drug.
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the absorption of Bismuth and salicylate from oral doses of pepto bismol Bismuth salicylate
Alimentary Pharmacology & Therapeutics, 2007Co-Authors: Chuka U. Nwokolo, P Mistry, Roy E. PounderAbstract:SUMMARY Plasma Bismuth and plasma salicylate concentrations were measured before and after three 30-ml oral doses of Bismuth salicylate (Pepto-Bismol liquid) in 10 fasting healthy subjects. From 0 to 120 min following the first dose of Bismuth salicylate, the plasma Bismuth concentration was less than 1 ng/ml. The peak median plasma Bismuth concentration was at + 240 min (1.7 ng/ml; range 0.8–5.3 ng/ml). Salicylate appeared in the plasma of all subjects at + 30 min, and it reached a peak at + 120 min (median 61 mg/L; range 46–104 mg/L). The study demonstrates that, despite rapid and substantial absorption of salicylate, there is negligible absorption of Bismuth into the bloodstream from standard oral doses of Bismuth salicylate.
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the absorption of Bismuth from oral doses of tripotassium dicitrato Bismuthate
Alimentary Pharmacology & Therapeutics, 2007Co-Authors: Chuka U. Nwokolo, C J Gavey, J T L Smith, Roy E. PounderAbstract:SUMMARY Two studies measured plasma concentrations of Bismuth during dosing with tripotassium dicitrato Bismuthate (De-Noltab). The first study compared 24 h plasma Bismuth concentration and urinary Bismuth excretion in six patients who had already received 29–131 days (median 47 days) of treatment with De-Noltab 2 b.d., and six healthy subjects who only received De-Noltab 2 b.d. on the day of study. There was a prompt rise in plasma Bismuth concentration after each dose of De-Noltabs. The median 24 h integrated plasma Bismuth concentration was similar in both groups, but the median 24 h urinary Bismuth excretion was 5.4-fold higher in the patients. The second study compared the plasma Bismuth concentrations after the first and third doses of De-Noltab 2 b.d. in 16 healthy subjects. The median peak Bismuth concentration occurred 30 min (range 15–105 min) post-dosing. The peak plasma Bismuth concentration was greater than 50 ng/ml in 14 of the 16 subjects, and greater than 100 ng/ml in nine of the subjects. There was no significant difference in the median integrated 10-h plasma Bismuth concentration after the first or third dose of De-Noltabs. The results of these studies confirm that Bismuth is absorbed and sequestrated during dosing with De-Noltabs. Bismuth is absorbed rapidly after oral dosing with De-NoItabs, to produce peak plasma Bismuth concentrations hitherto considered to be in the range associated with Bismuth neurotoxicity.
C J Gavey - One of the best experts on this subject based on the ideXlab platform.
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Bismuth accumulates in the body during treatment with tripotassium dicitrato Bismuthate
Alimentary Pharmacology & Therapeutics, 2007Co-Authors: C J Gavey, M L Szeto, J Sercombe, Chuka U. Nwokolo, Roy E. PounderAbstract:: Bismuth concentration was measured in plasma, dried leucocytes and urine in nine patients before, during and after treatment with tripotassium dicitrato Bismuthate (De-Noltab 2 b.d.) for 6 weeks. During treatment there was an 8.5-fold rise in median plasma Bismuth concentration (P less than 0.01), a non-significant doubling of leucocyte Bismuth content, and a 349-fold rise in 24-h urinary Bismuth excretion (P less than 0.01). The significantly increased urinary Bismuth excretion continued for at least 3 months after cessation of treatment with tripotassium dicitrato Bismuthate, indicating accumulation of Bismuth during treatment with this drug.
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the absorption of Bismuth from oral doses of tripotassium dicitrato Bismuthate
Alimentary Pharmacology & Therapeutics, 2007Co-Authors: Chuka U. Nwokolo, C J Gavey, J T L Smith, Roy E. PounderAbstract:SUMMARY Two studies measured plasma concentrations of Bismuth during dosing with tripotassium dicitrato Bismuthate (De-Noltab). The first study compared 24 h plasma Bismuth concentration and urinary Bismuth excretion in six patients who had already received 29–131 days (median 47 days) of treatment with De-Noltab 2 b.d., and six healthy subjects who only received De-Noltab 2 b.d. on the day of study. There was a prompt rise in plasma Bismuth concentration after each dose of De-Noltabs. The median 24 h integrated plasma Bismuth concentration was similar in both groups, but the median 24 h urinary Bismuth excretion was 5.4-fold higher in the patients. The second study compared the plasma Bismuth concentrations after the first and third doses of De-Noltab 2 b.d. in 16 healthy subjects. The median peak Bismuth concentration occurred 30 min (range 15–105 min) post-dosing. The peak plasma Bismuth concentration was greater than 50 ng/ml in 14 of the 16 subjects, and greater than 100 ng/ml in nine of the subjects. There was no significant difference in the median integrated 10-h plasma Bismuth concentration after the first or third dose of De-Noltabs. The results of these studies confirm that Bismuth is absorbed and sequestrated during dosing with De-Noltabs. Bismuth is absorbed rapidly after oral dosing with De-NoItabs, to produce peak plasma Bismuth concentrations hitherto considered to be in the range associated with Bismuth neurotoxicity.
