The Experts below are selected from a list of 89346 Experts worldwide ranked by ideXlab platform
Jin Ho Chung - One of the best experts on this subject based on the ideXlab platform.
-
silver nanoparticles promote procoagulant activity of red blood cells a potential risk of thrombosis in Susceptible Population
Particle and Fibre Toxicology, 2019Co-Authors: Yiying Bian, Jin Ho ChungAbstract:Background Silver nanoparticles (AgNP) are widely used in medical practices owing to their distinct antibacterial, antiviral and anticancer activities. However, with increasing use of AgNP, concerns over its potential toxicity are also escalating. Here, we demonstrated the potential thrombotic effect of AgNP which was mediated by the procoagulant activity of red blood cells (RBCs).
-
Silver nanoparticles promote procoagulant activity of red blood cells: a potential risk of thrombosis in Susceptible Population
Particle and Fibre Toxicology, 2019Co-Authors: Yiying Bian, Jin Ho ChungAbstract:Background Silver nanoparticles (AgNP) are widely used in medical practices owing to their distinct antibacterial, antiviral and anticancer activities. However, with increasing use of AgNP, concerns over its potential toxicity are also escalating. Here, we demonstrated the potential thrombotic effect of AgNP which was mediated by the procoagulant activity of red blood cells (RBCs). Results In freshly isolated human RBCs, AgNP, but not silver microparticles (AgMP), elicited morphological changes, phosphatidylserine (PS) exposure and microvesicles (MV) generation, the key indicators of procoagulant activity in RBCs at concentration ranges (≤ 100 μg/mL) that were free of significant hemolysis. In line with this, AgNP potentiated thrombin generation and adherence of RBCs to endothelial cells, while AgMP did not. Oxidative stress, intracellular calcium increase and ATP depletion were found to underlie the procoagulant effects of AgNP, which led to altered activity of membrane aminophospholipid translocases. These in vitro findings were well reproduced in rat in vivo, where intravenously exposure to AgNP promoted venous thrombosis significantly. Of note, RBCs isolated from cancer patients, who inherently convey the risk of thrombogenesis, were more sensitive to the procoagulant effects of AgNP. In addition, AgNP significantly potentiated the procoagulant effects of a chemotherapeutic drug, paclitaxel. Conclusion Collectively, these results suggest that AgNP may have prothrombotic risks by promoting procoagulant activity of RBCs and caution shall be taken for its use in the Population sensitive to thrombosis like cancer patients.
-
silver nanoparticles promote procoagulant activity of red blood cells a potential risk of thrombosis in Susceptible Population
Particle and Fibre Toxicology, 2019Co-Authors: Yiying Bian, Keunyoung Kim, Thien Ngo, Inho Kim, Oknam Bae, Kyungmin Lim, Jin Ho ChungAbstract:Silver nanoparticles (AgNP) are widely used in medical practices owing to their distinct antibacterial, antiviral and anticancer activities. However, with increasing use of AgNP, concerns over its potential toxicity are also escalating. Here, we demonstrated the potential thrombotic effect of AgNP which was mediated by the procoagulant activity of red blood cells (RBCs). In freshly isolated human RBCs, AgNP, but not silver microparticles (AgMP), elicited morphological changes, phosphatidylserine (PS) exposure and microvesicles (MV) generation, the key indicators of procoagulant activity in RBCs at concentration ranges (≤ 100 μg/mL) that were free of significant hemolysis. In line with this, AgNP potentiated thrombin generation and adherence of RBCs to endothelial cells, while AgMP did not. Oxidative stress, intracellular calcium increase and ATP depletion were found to underlie the procoagulant effects of AgNP, which led to altered activity of membrane aminophospholipid translocases. These in vitro findings were well reproduced in rat in vivo, where intravenously exposure to AgNP promoted venous thrombosis significantly. Of note, RBCs isolated from cancer patients, who inherently convey the risk of thrombogenesis, were more sensitive to the procoagulant effects of AgNP. In addition, AgNP significantly potentiated the procoagulant effects of a chemotherapeutic drug, paclitaxel. Collectively, these results suggest that AgNP may have prothrombotic risks by promoting procoagulant activity of RBCs and caution shall be taken for its use in the Population sensitive to thrombosis like cancer patients.
K T Goh - One of the best experts on this subject based on the ideXlab platform.
-
prevalence of diphtheria and tetanus antibodies among adults in singapore a national serological study to identify most Susceptible Population groups
Journal of Public Health, 2016Co-Authors: L W Ang, Lyn James, K T GohAbstract:BACKGROUND In view of waning antitoxin titres over time after the last vaccine dose against diphtheria and tetanus, we determined the immunity levels in adults to identify most Susceptible groups for protection in Singapore. METHODS Our study involved residual sera from 3293 adults aged 18-79 who had participated in a national health survey in 2010. IgG antibody levels were determined using commercial enzyme-linked immunosorbent assay. RESULTS Overall, 92.0% (95% confidence interval [CI]: 91.1-92.9%) had at least basic protection against diphtheria (antibody levels ≥0.01 IU/ml), while 71.4% (95% CI: 69.8-72.9%) had at least short-term protection against tetanus (antibody levels >0.1 IU/ml). The seroprevalence declined significantly with age for both diseases; the drop was most marked in the 50- to 59-year age group for diphtheria and 60- to 69-year age group for tetanus. There was a significant difference in seroprevalence by residency for diphtheria (92.8% among Singapore citizens versus 87.1% among permanent residents; P = 0.001). The seroprevalence for tetanus was significantly higher among males (83.2%) than females (62.4%) (P < 0.0005). CONCLUSIONS It may be of value to consider additional vaccination efforts to protect older adults at higher risk for exposure against diphtheria and tetanus, particularly those travelling to areas where diphtheria is endemic or epidemic.
Sherri Dennis - One of the best experts on this subject based on the ideXlab platform.
-
listeria monocytogenes dose response revisited incorporating adjustments for variability in strain virulence and host susceptibility
Risk Analysis, 2015Co-Authors: Régis Pouillot, Yuhuan Chen, Karin Hoelzer, Sherri DennisAbstract:Evaluations of Listeria monocytogenes dose-response relationships are crucially important for risk assessment and risk management, but are complicated by considerable variability across Population subgroups and L. monocytogenes strains. Despite difficulties associated with the collection of adequate data from outbreak investigations or sporadic cases, the limitations of currently available animal models, and the inability to conduct human volunteer studies, some of the available data now allow refinements of the well-established exponential L. monocytogenes dose response to more adequately represent extremely Susceptible Population subgroups and highly virulent L. monocytogenes strains. Here, a model incorporating adjustments for variability in L. monocytogenes strain virulence and host susceptibility was derived for 11 Population subgroups with similar underlying comorbidities using data from multiple sources, including human surveillance and food survey data. In light of the unique inherent properties of L. monocytogenes dose response, a lognormal-Poisson dose-response model was chosen, and proved able to reconcile dose-response relationships developed based on surveillance data with outbreak data. This model was compared to a classical beta-Poisson dose-response model, which was insufficiently flexible for modeling the specific case of L. monocytogenes dose-response relationships, especially in outbreak situations. Overall, the modeling results suggest that most listeriosis cases are linked to the ingestion of food contaminated with medium to high concentrations of L. monocytogenes. While additional data are needed to refine the derived model and to better characterize and quantify the variability in L. monocytogenes strain virulence and individual host susceptibility, the framework derived here represents a promising approach to more adequately characterize the risk of listeriosis in highly Susceptible Population subgroups.
-
Listeria monocytogenes Dose Response Revisited—Incorporating Adjustments for Variability in Strain Virulence and Host Susceptibility
Risk Analysis, 2014Co-Authors: Régis Pouillot, Yuhuan Chen, Karin Hoelzer, Sherri DennisAbstract:Evaluations of Listeria monocytogenes dose-response relationships are crucially important for risk assessment and risk management, but are complicated by considerable variability across Population subgroups and L. monocytogenes strains. Despite difficulties associated with the collection of adequate data from outbreak investigations or sporadic cases, the limitations of currently available animal models, and the inability to conduct human volunteer studies, some of the available data now allow refinements of the well-established exponential L. monocytogenes dose response to more adequately represent extremely Susceptible Population subgroups and highly virulent L. monocytogenes strains. Here, a model incorporating adjustments for variability in L. monocytogenes strain virulence and host susceptibility was derived for 11 Population subgroups with similar underlying comorbidities using data from multiple sources, including human surveillance and food survey data. In light of the unique inherent properties of L. monocytogenes dose response, a lognormal-Poisson dose-response model was chosen, and proved able to reconcile dose-response relationships developed based on surveillance data with outbreak data. This model was compared to a classical beta-Poisson dose-response model, which was insufficiently flexible for modeling the specific case of L. monocytogenes dose-response relationships, especially in outbreak situations. Overall, the modeling results suggest that most listeriosis cases are linked to the ingestion of food contaminated with medium to high concentrations of L. monocytogenes. While additional data are needed to refine the derived model and to better characterize and quantify the variability in L. monocytogenes strain virulence and individual host susceptibility, the framework derived here represents a promising approach to more adequately characterize the risk of listeriosis in highly Susceptible Population subgroups.
Lyn James - One of the best experts on this subject based on the ideXlab platform.
-
prevalence of diphtheria and tetanus antibodies among adults in singapore a national serological study to identify most Susceptible Population groups
Journal of Public Health, 2016Co-Authors: L W Ang, Lyn James, K T GohAbstract:BACKGROUND In view of waning antitoxin titres over time after the last vaccine dose against diphtheria and tetanus, we determined the immunity levels in adults to identify most Susceptible groups for protection in Singapore. METHODS Our study involved residual sera from 3293 adults aged 18-79 who had participated in a national health survey in 2010. IgG antibody levels were determined using commercial enzyme-linked immunosorbent assay. RESULTS Overall, 92.0% (95% confidence interval [CI]: 91.1-92.9%) had at least basic protection against diphtheria (antibody levels ≥0.01 IU/ml), while 71.4% (95% CI: 69.8-72.9%) had at least short-term protection against tetanus (antibody levels >0.1 IU/ml). The seroprevalence declined significantly with age for both diseases; the drop was most marked in the 50- to 59-year age group for diphtheria and 60- to 69-year age group for tetanus. There was a significant difference in seroprevalence by residency for diphtheria (92.8% among Singapore citizens versus 87.1% among permanent residents; P = 0.001). The seroprevalence for tetanus was significantly higher among males (83.2%) than females (62.4%) (P < 0.0005). CONCLUSIONS It may be of value to consider additional vaccination efforts to protect older adults at higher risk for exposure against diphtheria and tetanus, particularly those travelling to areas where diphtheria is endemic or epidemic.
-
Prevalence of diphtheria and tetanus antibodies among adults in Singapore: a national serological study to identify most Susceptible Population groups
Journal of Public Health, 2015Co-Authors: Lyn JamesAbstract:Background In view of waning antitoxin titres over time after the last vaccine dose against diphtheria and tetanus, we determined the immunity levels in adults to identify most Susceptible groups for protection in Singapore. Methods Our study involved residual sera from 3293 adults aged 18–79 who had participated in a national health survey in 2010. IgG antibody levels were determined using commercial enzyme-linked immunosorbent assay. Results Overall, 92.0% (95% confidence interval [CI]: 91.1–92.9%) had at least basic protection against diphtheria (antibody levels 0.01 IU/ml), while 71.4% (95% CI: 69.8–72.9%) had at least short-term protection against tetanus (antibody levels .0.1 IU/ml). The seroprevalence declined significantly with age for both diseases; the drop was most marked in the 50- to 59-year age group for diphtheria and 60- to 69-year age group for tetanus. There was a significant difference in seroprevalence by residency for diphtheria (92.8% among Singapore citizens versus 87.1% among permanent residents; P ¼ 0.001). The seroprevalence for tetanus was significantly higher among males (83.2%) than females (62.4%) (P , 0.0005).
Yiying Bian - One of the best experts on this subject based on the ideXlab platform.
-
silver nanoparticles promote procoagulant activity of red blood cells a potential risk of thrombosis in Susceptible Population
Particle and Fibre Toxicology, 2019Co-Authors: Yiying Bian, Jin Ho ChungAbstract:Background Silver nanoparticles (AgNP) are widely used in medical practices owing to their distinct antibacterial, antiviral and anticancer activities. However, with increasing use of AgNP, concerns over its potential toxicity are also escalating. Here, we demonstrated the potential thrombotic effect of AgNP which was mediated by the procoagulant activity of red blood cells (RBCs).
-
Silver nanoparticles promote procoagulant activity of red blood cells: a potential risk of thrombosis in Susceptible Population
Particle and Fibre Toxicology, 2019Co-Authors: Yiying Bian, Jin Ho ChungAbstract:Background Silver nanoparticles (AgNP) are widely used in medical practices owing to their distinct antibacterial, antiviral and anticancer activities. However, with increasing use of AgNP, concerns over its potential toxicity are also escalating. Here, we demonstrated the potential thrombotic effect of AgNP which was mediated by the procoagulant activity of red blood cells (RBCs). Results In freshly isolated human RBCs, AgNP, but not silver microparticles (AgMP), elicited morphological changes, phosphatidylserine (PS) exposure and microvesicles (MV) generation, the key indicators of procoagulant activity in RBCs at concentration ranges (≤ 100 μg/mL) that were free of significant hemolysis. In line with this, AgNP potentiated thrombin generation and adherence of RBCs to endothelial cells, while AgMP did not. Oxidative stress, intracellular calcium increase and ATP depletion were found to underlie the procoagulant effects of AgNP, which led to altered activity of membrane aminophospholipid translocases. These in vitro findings were well reproduced in rat in vivo, where intravenously exposure to AgNP promoted venous thrombosis significantly. Of note, RBCs isolated from cancer patients, who inherently convey the risk of thrombogenesis, were more sensitive to the procoagulant effects of AgNP. In addition, AgNP significantly potentiated the procoagulant effects of a chemotherapeutic drug, paclitaxel. Conclusion Collectively, these results suggest that AgNP may have prothrombotic risks by promoting procoagulant activity of RBCs and caution shall be taken for its use in the Population sensitive to thrombosis like cancer patients.
-
silver nanoparticles promote procoagulant activity of red blood cells a potential risk of thrombosis in Susceptible Population
Particle and Fibre Toxicology, 2019Co-Authors: Yiying Bian, Keunyoung Kim, Thien Ngo, Inho Kim, Oknam Bae, Kyungmin Lim, Jin Ho ChungAbstract:Silver nanoparticles (AgNP) are widely used in medical practices owing to their distinct antibacterial, antiviral and anticancer activities. However, with increasing use of AgNP, concerns over its potential toxicity are also escalating. Here, we demonstrated the potential thrombotic effect of AgNP which was mediated by the procoagulant activity of red blood cells (RBCs). In freshly isolated human RBCs, AgNP, but not silver microparticles (AgMP), elicited morphological changes, phosphatidylserine (PS) exposure and microvesicles (MV) generation, the key indicators of procoagulant activity in RBCs at concentration ranges (≤ 100 μg/mL) that were free of significant hemolysis. In line with this, AgNP potentiated thrombin generation and adherence of RBCs to endothelial cells, while AgMP did not. Oxidative stress, intracellular calcium increase and ATP depletion were found to underlie the procoagulant effects of AgNP, which led to altered activity of membrane aminophospholipid translocases. These in vitro findings were well reproduced in rat in vivo, where intravenously exposure to AgNP promoted venous thrombosis significantly. Of note, RBCs isolated from cancer patients, who inherently convey the risk of thrombogenesis, were more sensitive to the procoagulant effects of AgNP. In addition, AgNP significantly potentiated the procoagulant effects of a chemotherapeutic drug, paclitaxel. Collectively, these results suggest that AgNP may have prothrombotic risks by promoting procoagulant activity of RBCs and caution shall be taken for its use in the Population sensitive to thrombosis like cancer patients.
