The Experts below are selected from a list of 5652 Experts worldwide ranked by ideXlab platform
Daniel A Garcia - One of the best experts on this subject based on the ideXlab platform.
-
Dapsone associated fixed drug eruption
2017Co-Authors: Daniel A GarciaAbstract:ABSTRACTIntroduction: Dapsone is a sulfone drug used to treat infectious conditions and also numerous dermatologic diseases. Fixed drug eruption is a distinctive adverse cutaneous reaction associated with the initial administration and subsequent delivery of a specific agent.Areas covered: The authors preformed a literature search using the following keywords: Dapsone, fixed drug eruption, and adverse cutaneous drug reaction. Bibliographies were also reviewed for pertinent articles. The results were combed for relevant papers and reviewed. Articles pertaining to Dapsone-associated fixed drug eruption were included.Expert commentary: The majority of cases of Dapsone-associated fixed drug eruption in the literature come from Africa or India where there is a high prevalence of patients treated for leprosy. Characteristics of these cases are similar to fixed drug eruption described in the western literature, with differences in frequency of multiple versus solitary lesions. Dapsone-associated fixed drug erupt...
-
Dapsone-associated fixed drug eruption
2017Co-Authors: Daniel A GarciaAbstract:Dapsone is a sulfone drug used to treat infectious conditions and also numerous dermatologic diseases. Fixed drug eruption is a distinctive adverse cutaneous reaction associated with the initial administration and subsequent delivery of a specific agent. Areas covered: The authors preformed a literature search using the following keywords: Dapsone, fixed drug eruption, and adverse cutaneous drug reaction. Bibliographies were also reviewed for pertinent articles. The results were combed for relevant papers and reviewed. Articles pertaining to Dapsone-associated fixed drug eruption were included. Expert commentary: The majority of cases of Dapsone-associated fixed drug eruption in the literature come from Africa or India where there is a high prevalence of patients treated for leprosy. Characteristics of these cases are similar to fixed drug eruption described in the western literature, with differences in frequency of multiple versus solitary lesions. Dapsone-associated fixed drug eruption should be considered when reviewing the drug history of a patient with fixed drug eruption. In the case of darker pigmented individuals, multiple fixed drug eruption lesions may be more common. Multiple lesions may mimic Kaposi's sarcoma in human immunodeficiency virus positive patients. Dapsone-associated fixed drug eruption should be considered in the differential diagnosis of multiple hyperpigmented lesions.
Marinković, Aleksandar D. - One of the best experts on this subject based on the ideXlab platform.
-
Structural Properties of the Multiwall Carbon Nanotubes/Poly(Methyl Methacrylate) Nanocomposites: Effect of the Multiwall Carbon Nanotubes Covalent Functionalization
2017Co-Authors: Brković Danijela, Pavlović, Vladimir B., Pavlović, Vera P., Obradović Nina, Mitrić Miodrag, Stevanović Sanja, Vlahović Branislav, Uskoković, Petar S., Marinković, Aleksandar D.Abstract:The structural characteristics of polymer nanocomposites with functionalized multiwall carbon nanotubes (MWCNTs) in poly(methyl methacrylate) matrix have been studied in relation to nanofiller loading and surface functionality. Different functional groups have been covalently attached on the MWCNTs sidewalls in order to induce interfacial interactions at nanofiller/polymer interface, which resulted in an improved nanomechanical features. Structural properties of nanocomposites, studied with XRD and Raman analysis, indicated the most pronounced decrease in a degree of amorphousness for samples containing 0.5 and 1 wt% of MWCNTs functionalized with Dapsone (dapson-MWCNT) and diethyl malonate (dem-MWCNT). SEM and TEM micrographs confirmed improved dispersibility of the MWCNTs modified with aromatic structure of Dapsone inside PMMA matrix. A significant increase in a glass transition temperature of over 60°C has been found for the 1 wt% dapson-MWCNT nanocomposite. Additional modification of dapson-MWCNT by further increasing aromaticity and voluminosity of attached moiety (fid-MWCNT), showed 30°C increases in a glass transition temperature at 4 wt% of nanofiller loading, which is similar to shift of 37°C with loading of MWCNTs modified with ester terminal group. A maximum increase of 56% of reduced modulus and 86% of hardness was obtained for 1 wt% loading of dapson-MWCNT nanofiller
-
Structural Properties of the Multiwall Carbon Nanotubes/Poly(Methyl Methacrylate) Nanocomposites: Effect of the Multiwall Carbon Nanotubes Covalent Functionalization
2017Co-Authors: Brković Danijela, Pavlović, Vladimir B., Pavlović, Vera P., Mitrić Miodrag, Stevanović Sanja, Vlahović Branislav, Uskoković, Petar S., Obradovic Nina, Marinković, Aleksandar D.Abstract:The structural characteristics of polymer nanocomposites with functionalized multiwall carbon nanotubes (MWCNTs) in poly(methyl methacrylate) matrix have been studied in relation to nanofiller loading and surface functionality. Different functional groups have been covalently attached on the MWCNTs sidewalls in order to induce interfacial interactions at nanofiller/polymer interface, which resulted in an improved nanomechanical features. Structural properties of nanocomposites, studied with XRD and Raman analysis, indicated the most pronounced decrease in a degree of amorphousness for samples containing 0.5 and 1 wt% of MWCNTs functionalized with Dapsone (dapson-MWCNT) and diethyl malonate (dem-MWCNT). SEM and TEM micrographs confirmed improved dispersibility of the MWCNTs modified with aromatic structure of Dapsone inside PMMA matrix. A significant increase in a glass transition temperature of over 60 degrees C has been found for the 1 wt% dapson-MWCNT nanocomposite. Additional modification of dapson-MWCNT by further increasing aromaticity and voluminosity of attached moiety (fid-MWCNT), showed 30 degrees C increases in a glass transition temperature at 4 wt% of nanofiller loading, which is similar to shift of 37 degrees C with loading of MWCNTs modified with ester terminal group. A maximum increase of 56% of reduced modulus and 86% of hardness was obtained for 1 wt% loading of dapson-MWCNT nanofiller
-
Structural Properties of the Multiwall Carbon Nanotubes/Poly(Methyl Methacrylate) Nanocomposites: Effect of the Multiwall Carbon Nanotubes Covalent Functionalization
2017Co-Authors: Brković Danijela, Pavlović, Vladimir B., Pavlović, Vera P., Mitrić Miodrag, Vlahović Branislav, Obradovic Nina, Stevanovic Sanja, Uskokovic, Petar S., Marinković, Aleksandar D.Abstract:The structural characteristics of polymer nanocomposites with functionalized multiwall carbon nanotubes (MWCNTs) in poly(methyl methacrylate) matrix have been studied in relation to nanofiller loading and surface functionality. Different functional groups have been covalently attached on the MWCNTs sidewalls in order to induce interfacial interactions at nanofiller/polymer interface, which resulted in an improved nanomechanical features. Structural properties of nanocomposites, studied with XRD and Raman analysis, indicated the most pronounced decrease in a degree of amorphousness for samples containing 0.5 and 1 wt% of MWCNTs functionalized with Dapsone (dapson-MWCNT) and diethyl malonate (dem-MWCNT). SEM and TEM micrographs confirmed improved dispersibility of the MWCNTs modified with aromatic structure of Dapsone inside PMMA matrix. A significant increase in a glass transition temperature of over 60 degrees C has been found for the 1 wt% dapson-MWCNT nanocomposite. Additional modification of dapson-MWCNT by further increasing aromaticity and voluminosity of attached moiety (fid-MWCNT), showed 30 degrees C increases in a glass transition temperature at 4 wt% of nanofiller loading, which is similar to shift of 37 degrees C with loading of MWCNTs modified with ester terminal group. A maximum increase of 56% of reduced modulus and 86% of hardness was obtained for 1 wt% loading of dapson-MWCNT nanofiller. (C) 2016 Society of Plastics Engineer
-
Structural [roperties of the multiwall carbon nanotubes/poly(methyl methacrylate) nanocomposites: effect of the multiwall carbon nanotubes covalent functionalization
2017Co-Authors: Brković Danijela, Pavlović, Vladimir B., Pavlović, Vera P., Obradović Nina, Mitrić Miodrag, Stevanović Sanja, Vlahović Branislav, Uskoković, Petar S., Marinković, Aleksandar D.Abstract:The structural characteristics of polymer nanocomposites with functionalized multiwall carbon nanotubes (MWCNTs) in poly(methyl methacrylate) matrix have been studied in relation to nanofiller loading and surface functionality. Different functional groups have been covalently attached on the MWCNTs sidewalls in order to induce interfacial interactions at nanofiller/polymer interface, which resulted in an improved nanomechanical features. Structural properties of nanocomposites, studied with XRD and Raman analysis, indicated the most pronounced decrease in a degree of amorphousness for samples containing 0.5 and 1 wt% of MWCNTs functionalized with Dapsone (dapson-MWCNT) and diethyl malonate (dem-MWCNT). SEM and TEM micrographs confirmed improved dispersibility of the MWCNTs modified with aromatic structure of Dapsone inside PMMA matrix. A significant increase in a glass transition temperature of over 60°C has been found for the 1 wt% dapson-MWCNT nanocomposite. Additional modification of dapson-MWCNT by further increasing aromaticity and voluminosity of attached moiety (fid-MWCNT), showed 30°C increases in a glass transition temperature at 4 wt% of nanofiller loading, which is similar to shift of 37°C with loading of MWCNTs modified with ester terminal group. A maximum increase of 56% of reduced modulus and 86% of hardness was obtained for 1 wt% loading of dapson-MWCNT nanofiller
Hong Liu - One of the best experts on this subject based on the ideXlab platform.
-
Dapsone and nitroso Dapsone specific activation of t cells from hypersensitive patients expressing the risk allele hla b 13 01
2019Co-Authors: Qing Zhao, Khetam Alhilali, Abdulaziz Alzahrani, Mubarak Almutairi, Juwaria Amjad, Hong LiuAbstract:BACKGROUND:Research into drug hypersensitivity associated with expression of specific HLA alleles has focussed on the interaction between parent drug and the HLA with no attention given to reactive metabolites. For this reason, we have studied HLA-B*13:01-linked Dapsone hypersensitivity to (1) explore whether the parent drug and/or nitroso metabolite activates T-cells and (2) determine whether HLA-B*13:01 is involved in the response. METHODS:PBMC from 6 patients were cultured with Dapsone and nitroso Dapsone and proliferative responses and IFN-γ release were measured. Dapsone- and nitroso Dapsone-specific T-cell clones were generated and phenotype, function, HLA allele restriction and cross-reactivity assessed. Dapsone intermediates were characterized by mass spectrometry. RESULTS:PBMC from 6 patients and cloned T-cells proliferated and secreted Th1/2/22 cytokines when stimulated with Dapsone (clones: n=395; 80% CD4+ CXCR3hi CCR4hi , 20% CD8+CXCR3hi CCR4hi CCR6hi CCR9hi CCR10hi ) and nitroso Dapsone (clones: n=399; 78% CD4+, 22% CD8+ with same chemokine receptor profile). CD4+ and CD8+ clones were HLA-class II and class I restricted, respectively, and displayed three patterns of reactivity: compound-specific, weakly crossreactive and strongly cross reactive. Nitroso Dapsone formed dimers in culture and was reduced to Dapsone, providing a rationale for the crossreactivity. T-cell responses to nitroso Dapsone were dependent on the formation of a cysteine-modified protein adduct, while Dapsone interacted in a labile manner with antigen presenting cells. CD8+ clones displayed an HLA-B*13:01-restricted pattern of activation. CONCLUSION:These studies describe the phenotype and function of Dapsone- and nitroso Dapsone-responsive CD4+ and CD8+ T-cells from hypersensitive patients. Discovery of HLA-B*13:01-restricted CD8+ T-cell responses indicates that drugs and their reactive metabolites participate in HLA allele-linked forms of hypersensitivity. This article is protected by copyright. All rights reserved.
-
evaluation of prospective hla b 13 01 screening to prevent Dapsone hypersensitivity syndrome in patients with leprosy
2019Co-Authors: Hong Liu, Qing Zhao, Zhenzhen Wang, Fangfang Bao, Chuan Wang, Lele Sun, Huimin Zhang, Zhenhua Yue, Wei Zhao, Jing CaoAbstract:Importance Dapsone hypersensitivity syndrome (DHS) is the most serious adverse reaction associated with Dapsone administration and one of the major causes of death in patients with leprosy, whose standard treatment includes multidrug therapy (MDT) with Dapsone, rifampicin, and clofazimine. Although theHLA-B*13:01polymorphism has been identified as the genetic determinant of DHS in the Chinese population, no studies to date have been done to evaluate whether prospectiveHLA-B*13:01screening could prevent DHS by identifying patients who should not receive Dapsone. Objective To evaluate the clinical use of prospectiveHLA-B*13:01screening for reduction of the incidence of DHS by excluding Dapsone from the treatment for patients withHLA-B*13:01–positive leprosy. Design, Setting, and Participants A prospective cohort study was conducted from February 15, 2015, to April 30, 2018, in 21 provinces throughout China. A total of 1539 patients with newly diagnosed leprosy were enrolled who had not received Dapsone previously. After excluding patients who had a history of allergy to sulfones or glucose-6-phosphate dehydrogenase deficiency, 1512 individuals underwentHLA-B*13:01genotyping. All of the patients were followed up weekly for the first 8 weeks after treatment to monitor for adverse events. Exposures Patients who wereHLA-B*13:01carriers were instructed to eliminate Dapsone from their treatment regimens, and noncarrier patients received standard MDT. Main Outcomes and Measures The primary outcome was the incidence of DHS. The historical incidence rate of DHS (1.0%) was used as a control. Results Among 1512 patients (1026 [67.9%] men, 486 [32.1%] women; mean [SD] age, 43.1 [16.2] years), 261 (17.3%) were identified as carriers of theHLA-B*13:01allele. A total of 714 adverse events in 384 patients were observed during the follow-up period. Dapsone hypersensitivity syndrome did not develop in any of the 1251 patients who wereHLA-B*13:01–negative who received Dapsone, while approximately 13 patients would be expected to experience DHS, based on the historical incidence rate of 1.0% per year (P = 2.05 × 10−5). No significant correlation was found between other adverse events, including dermatologic or other events, andHLA-B*13:01status. Conclusions and Relevance ProspectiveHLA-B*13:01screening and subsequent elimination of Dapsone from MDT for patients withHLA-B*13:01–positive leprosy may significantly reduce the incidence of DHS in the Chinese population.
Qing Zhao - One of the best experts on this subject based on the ideXlab platform.
-
Dapsone and nitroso Dapsone specific activation of t cells from hypersensitive patients expressing the risk allele hla b 13 01
2019Co-Authors: Qing Zhao, Khetam Alhilali, Abdulaziz Alzahrani, Mubarak Almutairi, Juwaria Amjad, Hong LiuAbstract:BACKGROUND:Research into drug hypersensitivity associated with expression of specific HLA alleles has focussed on the interaction between parent drug and the HLA with no attention given to reactive metabolites. For this reason, we have studied HLA-B*13:01-linked Dapsone hypersensitivity to (1) explore whether the parent drug and/or nitroso metabolite activates T-cells and (2) determine whether HLA-B*13:01 is involved in the response. METHODS:PBMC from 6 patients were cultured with Dapsone and nitroso Dapsone and proliferative responses and IFN-γ release were measured. Dapsone- and nitroso Dapsone-specific T-cell clones were generated and phenotype, function, HLA allele restriction and cross-reactivity assessed. Dapsone intermediates were characterized by mass spectrometry. RESULTS:PBMC from 6 patients and cloned T-cells proliferated and secreted Th1/2/22 cytokines when stimulated with Dapsone (clones: n=395; 80% CD4+ CXCR3hi CCR4hi , 20% CD8+CXCR3hi CCR4hi CCR6hi CCR9hi CCR10hi ) and nitroso Dapsone (clones: n=399; 78% CD4+, 22% CD8+ with same chemokine receptor profile). CD4+ and CD8+ clones were HLA-class II and class I restricted, respectively, and displayed three patterns of reactivity: compound-specific, weakly crossreactive and strongly cross reactive. Nitroso Dapsone formed dimers in culture and was reduced to Dapsone, providing a rationale for the crossreactivity. T-cell responses to nitroso Dapsone were dependent on the formation of a cysteine-modified protein adduct, while Dapsone interacted in a labile manner with antigen presenting cells. CD8+ clones displayed an HLA-B*13:01-restricted pattern of activation. CONCLUSION:These studies describe the phenotype and function of Dapsone- and nitroso Dapsone-responsive CD4+ and CD8+ T-cells from hypersensitive patients. Discovery of HLA-B*13:01-restricted CD8+ T-cell responses indicates that drugs and their reactive metabolites participate in HLA allele-linked forms of hypersensitivity. This article is protected by copyright. All rights reserved.
-
evaluation of prospective hla b 13 01 screening to prevent Dapsone hypersensitivity syndrome in patients with leprosy
2019Co-Authors: Hong Liu, Qing Zhao, Zhenzhen Wang, Fangfang Bao, Chuan Wang, Lele Sun, Huimin Zhang, Zhenhua Yue, Wei Zhao, Jing CaoAbstract:Importance Dapsone hypersensitivity syndrome (DHS) is the most serious adverse reaction associated with Dapsone administration and one of the major causes of death in patients with leprosy, whose standard treatment includes multidrug therapy (MDT) with Dapsone, rifampicin, and clofazimine. Although theHLA-B*13:01polymorphism has been identified as the genetic determinant of DHS in the Chinese population, no studies to date have been done to evaluate whether prospectiveHLA-B*13:01screening could prevent DHS by identifying patients who should not receive Dapsone. Objective To evaluate the clinical use of prospectiveHLA-B*13:01screening for reduction of the incidence of DHS by excluding Dapsone from the treatment for patients withHLA-B*13:01–positive leprosy. Design, Setting, and Participants A prospective cohort study was conducted from February 15, 2015, to April 30, 2018, in 21 provinces throughout China. A total of 1539 patients with newly diagnosed leprosy were enrolled who had not received Dapsone previously. After excluding patients who had a history of allergy to sulfones or glucose-6-phosphate dehydrogenase deficiency, 1512 individuals underwentHLA-B*13:01genotyping. All of the patients were followed up weekly for the first 8 weeks after treatment to monitor for adverse events. Exposures Patients who wereHLA-B*13:01carriers were instructed to eliminate Dapsone from their treatment regimens, and noncarrier patients received standard MDT. Main Outcomes and Measures The primary outcome was the incidence of DHS. The historical incidence rate of DHS (1.0%) was used as a control. Results Among 1512 patients (1026 [67.9%] men, 486 [32.1%] women; mean [SD] age, 43.1 [16.2] years), 261 (17.3%) were identified as carriers of theHLA-B*13:01allele. A total of 714 adverse events in 384 patients were observed during the follow-up period. Dapsone hypersensitivity syndrome did not develop in any of the 1251 patients who wereHLA-B*13:01–negative who received Dapsone, while approximately 13 patients would be expected to experience DHS, based on the historical incidence rate of 1.0% per year (P = 2.05 × 10−5). No significant correlation was found between other adverse events, including dermatologic or other events, andHLA-B*13:01status. Conclusions and Relevance ProspectiveHLA-B*13:01screening and subsequent elimination of Dapsone from MDT for patients withHLA-B*13:01–positive leprosy may significantly reduce the incidence of DHS in the Chinese population.
David E Fisher - One of the best experts on this subject based on the ideXlab platform.
-
Dapsone or Electric Shock Therapy of Brown Recluse Spider Envenomation
1994Co-Authors: Steven M. Barrett, Maxine Romine-jenkins, David E FisherAbstract:Abstract Study objectives: We tested the null hypothesis that no outcome differences exist among the treatment groups of animals with brown recluse spider envenomations. Study design: A prospective, placebo-controlled, experimental trial. Hartley guinea pigs were randomized into the following treatment groups: Dapsone, Parali/azer stun gun, Guardian stun gun, and control. Interventions: Brown recluse spider skin lesions were induced with intradermal injections of 30 μg spider venom and were treated beginning 16 hours after inoculation. Shock regimens consisted of four cross shocks of 1-second duration on anesthetized animals. Oral Dapsone treatment was 0.7 mg/kg twice daily for 3 days. Lesion areas were measured daily for 3 days. Results: The Dapsone therapy group demonstrated significantly less induration and necrosis ( P Conclusion: Dapsone therapy is more effective than either electric shock or no therapy for brown recluse spider envenomation in the guinea pig model. [Barrett SM, Romine-Jenkins M, Fisher DE: Dapsone or electric shock therapy of brown recluse spider envenomation? Ann Emerg Med July 1994;24:21-25.]
