The Experts below are selected from a list of 33 Experts worldwide ranked by ideXlab platform
M. Breward - One of the best experts on this subject based on the ideXlab platform.
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In-Vitro Determination of Arsenic Bioavailability in Contaminated Soil and Mineral Beneficiation Waste from Ron Phibun, Southern Thailand: A Basis for Improved Human Risk Assessment
Environmental Geochemistry and Health, 1998Co-Authors: T.m. Williams, B.g. Rawlins, B. Smith, M. BrewardAbstract:The post-ingestion bioavailability of arsenic (As) in alluvial soil and mineral beneficiation waste from Ron Phibun, Nakhon Si Thammarat Province, Thailand has been investigated using a physiologically-based extraction test (PBET). The method utilises synthetic leaching fluids closely analogous to those of the human Stomach and small intestine, upon which the leaching duration and ambient temperature of the experimental procedure are also directly based. Replicate analyses of Ron Phibun alluvium samples holding 1406 and 2123 μg As g-1 respectively indicated an average Stomach Absorption of 11.2% (of total soil As). Gross Absorption increased to 18.9% following translocation through a simulated small-intenstine regime. Higher gross Absorption (35.7%) was recorded during PBET analysis of a flotation waste sample holding c. 2% total As. Within- and between-site variations of As bioavailability can principally be ascribed to mineralogical factors, notably the relative abundances of sulphide, arsenide, arsenate and oxide hosts within the soil/flotation waste matrix. The PBET provides a potentially valuable mechanism for refining risk assessments of sites subject to natural or anthropogenic As contamination. Through the substitution of total soil As values with input data which relate specifically to bioavailable As, risk calculations derived using established models such as the US-EPA package Risk Assistant may prove more realistic, thus facilitating improved cost-benefit analysis of site remediation options. Assessment of the relative human risks associated with potable water consumption and contaminated soil ingestion at Ron Phibun has signified that the latter could constitute a more significant As exposure pathway than recognised previously. Further evaluation of the precise soil ingestion levels of inhabitants residing on the As-rich alluvium which covers much of the district is, therefore, warranted.
Rikke K Kirk - One of the best experts on this subject based on the ideXlab platform.
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transcellular Stomach Absorption of a derivatized glucagon like peptide 1 receptor agonist
Science Translational Medicine, 2018Co-Authors: Stephen T Buckley, Tine A Baekdal, Andreas Vegge, Stine Maarbjerg, Charles Pyke, Jonas Ahnfeltronne, Kim G Madsen, Susanne Scheele, Tomas Alanentalo, Rikke K KirkAbstract:Oral administration of therapeutic peptides is hindered by poor Absorption across the gastrointestinal barrier and extensive degradation by proteolytic enzymes. Here, we investigated the Absorption of orally delivered semaglutide, a glucagon-like peptide-1 analog, coformulated with the Absorption enhancer sodium N -[8-(2-hydroxybenzoyl) aminocaprylate] (SNAC) in a tablet. In contrast to intestinal Absorption usually seen with small molecules, clinical and preclinical dog studies revealed that Absorption of semaglutide takes place in the Stomach, is confined to an area in close proximity to the tablet surface, and requires coformulation with SNAC. SNAC protects against enzymatic degradation via local buffering actions and only transiently enhances Absorption. The mechanism of Absorption is shown to be compound specific, transcellular, and without any evidence of effect on tight junctions. These data have implications for understanding how highly efficacious and specific therapeutic peptides could be transformed from injectable to tablet-based oral therapies.
T.m. Williams - One of the best experts on this subject based on the ideXlab platform.
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In-Vitro Determination of Arsenic Bioavailability in Contaminated Soil and Mineral Beneficiation Waste from Ron Phibun, Southern Thailand: A Basis for Improved Human Risk Assessment
Environmental Geochemistry and Health, 1998Co-Authors: T.m. Williams, B.g. Rawlins, B. Smith, M. BrewardAbstract:The post-ingestion bioavailability of arsenic (As) in alluvial soil and mineral beneficiation waste from Ron Phibun, Nakhon Si Thammarat Province, Thailand has been investigated using a physiologically-based extraction test (PBET). The method utilises synthetic leaching fluids closely analogous to those of the human Stomach and small intestine, upon which the leaching duration and ambient temperature of the experimental procedure are also directly based. Replicate analyses of Ron Phibun alluvium samples holding 1406 and 2123 μg As g-1 respectively indicated an average Stomach Absorption of 11.2% (of total soil As). Gross Absorption increased to 18.9% following translocation through a simulated small-intenstine regime. Higher gross Absorption (35.7%) was recorded during PBET analysis of a flotation waste sample holding c. 2% total As. Within- and between-site variations of As bioavailability can principally be ascribed to mineralogical factors, notably the relative abundances of sulphide, arsenide, arsenate and oxide hosts within the soil/flotation waste matrix. The PBET provides a potentially valuable mechanism for refining risk assessments of sites subject to natural or anthropogenic As contamination. Through the substitution of total soil As values with input data which relate specifically to bioavailable As, risk calculations derived using established models such as the US-EPA package Risk Assistant may prove more realistic, thus facilitating improved cost-benefit analysis of site remediation options. Assessment of the relative human risks associated with potable water consumption and contaminated soil ingestion at Ron Phibun has signified that the latter could constitute a more significant As exposure pathway than recognised previously. Further evaluation of the precise soil ingestion levels of inhabitants residing on the As-rich alluvium which covers much of the district is, therefore, warranted.
Stephen T Buckley - One of the best experts on this subject based on the ideXlab platform.
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transcellular Stomach Absorption of a derivatized glucagon like peptide 1 receptor agonist
Science Translational Medicine, 2018Co-Authors: Stephen T Buckley, Tine A Baekdal, Andreas Vegge, Stine Maarbjerg, Charles Pyke, Jonas Ahnfeltronne, Kim G Madsen, Susanne Scheele, Tomas Alanentalo, Rikke K KirkAbstract:Oral administration of therapeutic peptides is hindered by poor Absorption across the gastrointestinal barrier and extensive degradation by proteolytic enzymes. Here, we investigated the Absorption of orally delivered semaglutide, a glucagon-like peptide-1 analog, coformulated with the Absorption enhancer sodium N -[8-(2-hydroxybenzoyl) aminocaprylate] (SNAC) in a tablet. In contrast to intestinal Absorption usually seen with small molecules, clinical and preclinical dog studies revealed that Absorption of semaglutide takes place in the Stomach, is confined to an area in close proximity to the tablet surface, and requires coformulation with SNAC. SNAC protects against enzymatic degradation via local buffering actions and only transiently enhances Absorption. The mechanism of Absorption is shown to be compound specific, transcellular, and without any evidence of effect on tight junctions. These data have implications for understanding how highly efficacious and specific therapeutic peptides could be transformed from injectable to tablet-based oral therapies.
B.g. Rawlins - One of the best experts on this subject based on the ideXlab platform.
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In-Vitro Determination of Arsenic Bioavailability in Contaminated Soil and Mineral Beneficiation Waste from Ron Phibun, Southern Thailand: A Basis for Improved Human Risk Assessment
Environmental Geochemistry and Health, 1998Co-Authors: T.m. Williams, B.g. Rawlins, B. Smith, M. BrewardAbstract:The post-ingestion bioavailability of arsenic (As) in alluvial soil and mineral beneficiation waste from Ron Phibun, Nakhon Si Thammarat Province, Thailand has been investigated using a physiologically-based extraction test (PBET). The method utilises synthetic leaching fluids closely analogous to those of the human Stomach and small intestine, upon which the leaching duration and ambient temperature of the experimental procedure are also directly based. Replicate analyses of Ron Phibun alluvium samples holding 1406 and 2123 μg As g-1 respectively indicated an average Stomach Absorption of 11.2% (of total soil As). Gross Absorption increased to 18.9% following translocation through a simulated small-intenstine regime. Higher gross Absorption (35.7%) was recorded during PBET analysis of a flotation waste sample holding c. 2% total As. Within- and between-site variations of As bioavailability can principally be ascribed to mineralogical factors, notably the relative abundances of sulphide, arsenide, arsenate and oxide hosts within the soil/flotation waste matrix. The PBET provides a potentially valuable mechanism for refining risk assessments of sites subject to natural or anthropogenic As contamination. Through the substitution of total soil As values with input data which relate specifically to bioavailable As, risk calculations derived using established models such as the US-EPA package Risk Assistant may prove more realistic, thus facilitating improved cost-benefit analysis of site remediation options. Assessment of the relative human risks associated with potable water consumption and contaminated soil ingestion at Ron Phibun has signified that the latter could constitute a more significant As exposure pathway than recognised previously. Further evaluation of the precise soil ingestion levels of inhabitants residing on the As-rich alluvium which covers much of the district is, therefore, warranted.