The Experts below are selected from a list of 9012 Experts worldwide ranked by ideXlab platform
Patrick F Kiser - One of the best experts on this subject based on the ideXlab platform.
-
Engineering a segmented dual-reservoir polyurethane intravaginal ring for simultaneous prevention of HIV transmission and Unwanted Pregnancy. PLoS One 2014
2016Co-Authors: Justin T. Clark, Meredith R. Clark, Namdev B. Shelke, Todd J. Johnson, Eric M. Smith, Andrew K. Andreasen, Joel S. Nebeker, Judit Fabian, David R. Friend, Patrick F KiserAbstract:The HIV/AIDS pandemic and its impact on women prompt the investigation of prevention strategies to interrupt sexual transmission of HIV. Long-acting drug delivery systems that simultaneously protect womenfrom sexual transmission of HIV and Unwanted Pregnancy could be important tools in combating the pandemic. We describe the design, in silico, in vitro and in vivo evaluation of a dual-reservoir intravaginal ring that delivers the HIV-1 reverse transcriptase inhibitor tenofovir and the contraceptive levonorgestrel for 90 days. Two polyether urethanes with two different hard segment volume fractions were used to make coaxial extruded reservoir segments with a 100 mm thick rate controlling membrane and a diameter of 5.5 mm that contain 1.3 wt % levonorgestrel. A new mechanistic diffusion model accurately described the levonorgestrel burst release in early time points and pseudo-steady state behavior at later time points. As previously described, tenofovir was formulated as a glycerol paste and filled into a hydrophilic polyurethane, hollow tube reservoir that was melt-sealed by induction welding. These tenofovir-eluting segments and 2 cm long coaxially extruded levonorgestrel eluting segments were joined by induction welding to form rings that released an average of 7.5 mg tenofovir and 21 mg levonorgestrel per day in vitro for 90 days. Levonorgestrel segments placed intravaginally in rabbits resulted in sustained, dose-dependent levels of levonorgestrel in plasma and cervical tissue for 90 days. Polyurethane caps placed between segments successfully prevented diffusion of levonorgestrel into the tenofovir-releasing segment during storage.Hydrate
-
engineering a segmented dual reservoir polyurethane intravaginal ring for simultaneous prevention of hiv transmission and Unwanted Pregnancy
2014Co-Authors: Justin T. Clark, Meredith R. Clark, Namdev B. Shelke, Todd J. Johnson, Andrew K. Andreasen, Joel S. Nebeker, Judit Fabian, David R. Friend, Eric Smith, Patrick F KiserAbstract:The HIV/AIDS pandemic and its impact on women prompt the investigation of prevention strategies to interrupt sexual transmission of HIV. Long-acting drug delivery systems that simultaneously protect womenfrom sexual transmission of HIV and Unwanted Pregnancy could be important tools in combating the pandemic. We describe the design, in silico, in vitro and in vivo evaluation of a dual-reservoir intravaginal ring that delivers the HIV-1 reverse transcriptase inhibitor tenofovir and the contraceptive levonorgestrel for 90 days. Two polyether urethanes with two different hard segment volume fractions were used to make coaxial extruded reservoir segments with a 100 µm thick rate controlling membrane and a diameter of 5.5 mm that contain 1.3 wt% levonorgestrel. A new mechanistic diffusion model accurately described the levonorgestrel burst release in early time points and pseudo-steady state behavior at later time points. As previously described, tenofovir was formulated as a glycerol paste and filled into a hydrophilic polyurethane, hollow tube reservoir that was melt-sealed by induction welding. These tenofovir-eluting segments and 2 cm long coaxially extruded levonorgestrel eluting segments were joined by induction welding to form rings that released an average of 7.5 mg tenofovir and 21 µg levonorgestrel per day in vitro for 90 days. Levonorgestrel segments placed intravaginally in rabbits resulted in sustained, dose-dependent levels of levonorgestrel in plasma and cervical tissue for 90 days. Polyurethane caps placed between segments successfully prevented diffusion of levonorgestrel into the tenofovir-releasing segment during storage.Hydrated rings endured between 152 N and 354 N tensile load before failure during uniaxial extension testing. In summary, this system represents a significant advance in vaginal drug delivery technology, and is the first in a new class of long-acting multipurpose prevention drug delivery systems.
Justin T. Clark - One of the best experts on this subject based on the ideXlab platform.
-
Engineering a segmented dual-reservoir polyurethane intravaginal ring for simultaneous prevention of HIV transmission and Unwanted Pregnancy. PLoS One 2014
2016Co-Authors: Justin T. Clark, Meredith R. Clark, Namdev B. Shelke, Todd J. Johnson, Eric M. Smith, Andrew K. Andreasen, Joel S. Nebeker, Judit Fabian, David R. Friend, Patrick F KiserAbstract:The HIV/AIDS pandemic and its impact on women prompt the investigation of prevention strategies to interrupt sexual transmission of HIV. Long-acting drug delivery systems that simultaneously protect womenfrom sexual transmission of HIV and Unwanted Pregnancy could be important tools in combating the pandemic. We describe the design, in silico, in vitro and in vivo evaluation of a dual-reservoir intravaginal ring that delivers the HIV-1 reverse transcriptase inhibitor tenofovir and the contraceptive levonorgestrel for 90 days. Two polyether urethanes with two different hard segment volume fractions were used to make coaxial extruded reservoir segments with a 100 mm thick rate controlling membrane and a diameter of 5.5 mm that contain 1.3 wt % levonorgestrel. A new mechanistic diffusion model accurately described the levonorgestrel burst release in early time points and pseudo-steady state behavior at later time points. As previously described, tenofovir was formulated as a glycerol paste and filled into a hydrophilic polyurethane, hollow tube reservoir that was melt-sealed by induction welding. These tenofovir-eluting segments and 2 cm long coaxially extruded levonorgestrel eluting segments were joined by induction welding to form rings that released an average of 7.5 mg tenofovir and 21 mg levonorgestrel per day in vitro for 90 days. Levonorgestrel segments placed intravaginally in rabbits resulted in sustained, dose-dependent levels of levonorgestrel in plasma and cervical tissue for 90 days. Polyurethane caps placed between segments successfully prevented diffusion of levonorgestrel into the tenofovir-releasing segment during storage.Hydrate
-
engineering a segmented dual reservoir polyurethane intravaginal ring for simultaneous prevention of hiv transmission and Unwanted Pregnancy
2014Co-Authors: Justin T. Clark, Meredith R. Clark, Namdev B. Shelke, Todd J. Johnson, Andrew K. Andreasen, Joel S. Nebeker, Judit Fabian, David R. Friend, Eric Smith, Patrick F KiserAbstract:The HIV/AIDS pandemic and its impact on women prompt the investigation of prevention strategies to interrupt sexual transmission of HIV. Long-acting drug delivery systems that simultaneously protect womenfrom sexual transmission of HIV and Unwanted Pregnancy could be important tools in combating the pandemic. We describe the design, in silico, in vitro and in vivo evaluation of a dual-reservoir intravaginal ring that delivers the HIV-1 reverse transcriptase inhibitor tenofovir and the contraceptive levonorgestrel for 90 days. Two polyether urethanes with two different hard segment volume fractions were used to make coaxial extruded reservoir segments with a 100 µm thick rate controlling membrane and a diameter of 5.5 mm that contain 1.3 wt% levonorgestrel. A new mechanistic diffusion model accurately described the levonorgestrel burst release in early time points and pseudo-steady state behavior at later time points. As previously described, tenofovir was formulated as a glycerol paste and filled into a hydrophilic polyurethane, hollow tube reservoir that was melt-sealed by induction welding. These tenofovir-eluting segments and 2 cm long coaxially extruded levonorgestrel eluting segments were joined by induction welding to form rings that released an average of 7.5 mg tenofovir and 21 µg levonorgestrel per day in vitro for 90 days. Levonorgestrel segments placed intravaginally in rabbits resulted in sustained, dose-dependent levels of levonorgestrel in plasma and cervical tissue for 90 days. Polyurethane caps placed between segments successfully prevented diffusion of levonorgestrel into the tenofovir-releasing segment during storage.Hydrated rings endured between 152 N and 354 N tensile load before failure during uniaxial extension testing. In summary, this system represents a significant advance in vaginal drug delivery technology, and is the first in a new class of long-acting multipurpose prevention drug delivery systems.
Nori Takei - One of the best experts on this subject based on the ideXlab platform.
-
psychosocial determinants of mistimed and Unwanted Pregnancy the hamamatsu birth cohort hbc study
2012Co-Authors: Shun Takahashi, Kenji J Tsuchiya, Kaori Matsumoto, Katsuaki Suzuki, Norio Mori, Nori TakeiAbstract:The terms mistimed Pregnancy (MP) and Unwanted Pregnancy (UWP) refer to a woman’s intentions regarding childbearing. Determinants for each type of Pregnancy have not been well understood. The present study aims to investigate whether MP and UWP have different sets of psychosocial determinants compared to intended Pregnancy, with a particular emphasis on any difference in the history of maternal psychiatric diagnosis. Using an ongoing birth cohort study, we consecutively enrolled parturients who were at mid-Pregnancy (n = 780) and were expected to give birth at either of our two research sites. MP and UWP were defined according to previous studies. To avoid multiple testing, we adopted multinomial logistic regression to estimate the independent contribution of the determinants while simultaneously allowing for other variables. The dependent variable in the model had three classes: Intended Pregnancy, MP and UWP. Determinants of MP included younger age (<25 years: OR = 2.6), currently working (OR = 1.6), and history of major depression (OR = 2.0). Determinants for UWP were multiparity (OR = 3.9), short (≤12 years, OR = 1.7) and long period of education (≥17 years, OR = 3.3), history of anxiety disorder (OR = 2.5), currently working (OR = 0.6) and high income (≥8 million JPY, OR = 0.4). Different sets of psychosocial determinants contribute to formulate MP and UWP. A history of mental illness plays a role in predicting Pregnancy intention.
-
erratum to psychosocial determinants of mistimed and Unwanted Pregnancy the hamamatsu birth cohort hbc study
2012Co-Authors: Shun Takahashi, Kenji J Tsuchiya, Kaori Matsumoto, Katsuaki Suzuki, Norio Mori, Nori TakeiAbstract:In the article ‘‘Psychosocial Determinants of Mistimed and Unwanted Pregnancy: The Hamamatsu Birth Cohort (HBC) Study’’ by S. Takahashi et al., the Method section contained an error in the text. In the first paragraph, under the subheading of Measurement, the fourth and fifth sentences should read as follows: ‘‘Among those who answered negatively to this question, a second question was posed—namely, was the Pregnancy wanted or not? If no, the parturients were categorized into the UWP group.’’
Andrew K. Andreasen - One of the best experts on this subject based on the ideXlab platform.
-
Engineering a segmented dual-reservoir polyurethane intravaginal ring for simultaneous prevention of HIV transmission and Unwanted Pregnancy. PLoS One 2014
2016Co-Authors: Justin T. Clark, Meredith R. Clark, Namdev B. Shelke, Todd J. Johnson, Eric M. Smith, Andrew K. Andreasen, Joel S. Nebeker, Judit Fabian, David R. Friend, Patrick F KiserAbstract:The HIV/AIDS pandemic and its impact on women prompt the investigation of prevention strategies to interrupt sexual transmission of HIV. Long-acting drug delivery systems that simultaneously protect womenfrom sexual transmission of HIV and Unwanted Pregnancy could be important tools in combating the pandemic. We describe the design, in silico, in vitro and in vivo evaluation of a dual-reservoir intravaginal ring that delivers the HIV-1 reverse transcriptase inhibitor tenofovir and the contraceptive levonorgestrel for 90 days. Two polyether urethanes with two different hard segment volume fractions were used to make coaxial extruded reservoir segments with a 100 mm thick rate controlling membrane and a diameter of 5.5 mm that contain 1.3 wt % levonorgestrel. A new mechanistic diffusion model accurately described the levonorgestrel burst release in early time points and pseudo-steady state behavior at later time points. As previously described, tenofovir was formulated as a glycerol paste and filled into a hydrophilic polyurethane, hollow tube reservoir that was melt-sealed by induction welding. These tenofovir-eluting segments and 2 cm long coaxially extruded levonorgestrel eluting segments were joined by induction welding to form rings that released an average of 7.5 mg tenofovir and 21 mg levonorgestrel per day in vitro for 90 days. Levonorgestrel segments placed intravaginally in rabbits resulted in sustained, dose-dependent levels of levonorgestrel in plasma and cervical tissue for 90 days. Polyurethane caps placed between segments successfully prevented diffusion of levonorgestrel into the tenofovir-releasing segment during storage.Hydrate
-
engineering a segmented dual reservoir polyurethane intravaginal ring for simultaneous prevention of hiv transmission and Unwanted Pregnancy
2014Co-Authors: Justin T. Clark, Meredith R. Clark, Namdev B. Shelke, Todd J. Johnson, Andrew K. Andreasen, Joel S. Nebeker, Judit Fabian, David R. Friend, Eric Smith, Patrick F KiserAbstract:The HIV/AIDS pandemic and its impact on women prompt the investigation of prevention strategies to interrupt sexual transmission of HIV. Long-acting drug delivery systems that simultaneously protect womenfrom sexual transmission of HIV and Unwanted Pregnancy could be important tools in combating the pandemic. We describe the design, in silico, in vitro and in vivo evaluation of a dual-reservoir intravaginal ring that delivers the HIV-1 reverse transcriptase inhibitor tenofovir and the contraceptive levonorgestrel for 90 days. Two polyether urethanes with two different hard segment volume fractions were used to make coaxial extruded reservoir segments with a 100 µm thick rate controlling membrane and a diameter of 5.5 mm that contain 1.3 wt% levonorgestrel. A new mechanistic diffusion model accurately described the levonorgestrel burst release in early time points and pseudo-steady state behavior at later time points. As previously described, tenofovir was formulated as a glycerol paste and filled into a hydrophilic polyurethane, hollow tube reservoir that was melt-sealed by induction welding. These tenofovir-eluting segments and 2 cm long coaxially extruded levonorgestrel eluting segments were joined by induction welding to form rings that released an average of 7.5 mg tenofovir and 21 µg levonorgestrel per day in vitro for 90 days. Levonorgestrel segments placed intravaginally in rabbits resulted in sustained, dose-dependent levels of levonorgestrel in plasma and cervical tissue for 90 days. Polyurethane caps placed between segments successfully prevented diffusion of levonorgestrel into the tenofovir-releasing segment during storage.Hydrated rings endured between 152 N and 354 N tensile load before failure during uniaxial extension testing. In summary, this system represents a significant advance in vaginal drug delivery technology, and is the first in a new class of long-acting multipurpose prevention drug delivery systems.
Todd J. Johnson - One of the best experts on this subject based on the ideXlab platform.
-
Engineering a segmented dual-reservoir polyurethane intravaginal ring for simultaneous prevention of HIV transmission and Unwanted Pregnancy. PLoS One 2014
2016Co-Authors: Justin T. Clark, Meredith R. Clark, Namdev B. Shelke, Todd J. Johnson, Eric M. Smith, Andrew K. Andreasen, Joel S. Nebeker, Judit Fabian, David R. Friend, Patrick F KiserAbstract:The HIV/AIDS pandemic and its impact on women prompt the investigation of prevention strategies to interrupt sexual transmission of HIV. Long-acting drug delivery systems that simultaneously protect womenfrom sexual transmission of HIV and Unwanted Pregnancy could be important tools in combating the pandemic. We describe the design, in silico, in vitro and in vivo evaluation of a dual-reservoir intravaginal ring that delivers the HIV-1 reverse transcriptase inhibitor tenofovir and the contraceptive levonorgestrel for 90 days. Two polyether urethanes with two different hard segment volume fractions were used to make coaxial extruded reservoir segments with a 100 mm thick rate controlling membrane and a diameter of 5.5 mm that contain 1.3 wt % levonorgestrel. A new mechanistic diffusion model accurately described the levonorgestrel burst release in early time points and pseudo-steady state behavior at later time points. As previously described, tenofovir was formulated as a glycerol paste and filled into a hydrophilic polyurethane, hollow tube reservoir that was melt-sealed by induction welding. These tenofovir-eluting segments and 2 cm long coaxially extruded levonorgestrel eluting segments were joined by induction welding to form rings that released an average of 7.5 mg tenofovir and 21 mg levonorgestrel per day in vitro for 90 days. Levonorgestrel segments placed intravaginally in rabbits resulted in sustained, dose-dependent levels of levonorgestrel in plasma and cervical tissue for 90 days. Polyurethane caps placed between segments successfully prevented diffusion of levonorgestrel into the tenofovir-releasing segment during storage.Hydrate
-
engineering a segmented dual reservoir polyurethane intravaginal ring for simultaneous prevention of hiv transmission and Unwanted Pregnancy
2014Co-Authors: Justin T. Clark, Meredith R. Clark, Namdev B. Shelke, Todd J. Johnson, Andrew K. Andreasen, Joel S. Nebeker, Judit Fabian, David R. Friend, Eric Smith, Patrick F KiserAbstract:The HIV/AIDS pandemic and its impact on women prompt the investigation of prevention strategies to interrupt sexual transmission of HIV. Long-acting drug delivery systems that simultaneously protect womenfrom sexual transmission of HIV and Unwanted Pregnancy could be important tools in combating the pandemic. We describe the design, in silico, in vitro and in vivo evaluation of a dual-reservoir intravaginal ring that delivers the HIV-1 reverse transcriptase inhibitor tenofovir and the contraceptive levonorgestrel for 90 days. Two polyether urethanes with two different hard segment volume fractions were used to make coaxial extruded reservoir segments with a 100 µm thick rate controlling membrane and a diameter of 5.5 mm that contain 1.3 wt% levonorgestrel. A new mechanistic diffusion model accurately described the levonorgestrel burst release in early time points and pseudo-steady state behavior at later time points. As previously described, tenofovir was formulated as a glycerol paste and filled into a hydrophilic polyurethane, hollow tube reservoir that was melt-sealed by induction welding. These tenofovir-eluting segments and 2 cm long coaxially extruded levonorgestrel eluting segments were joined by induction welding to form rings that released an average of 7.5 mg tenofovir and 21 µg levonorgestrel per day in vitro for 90 days. Levonorgestrel segments placed intravaginally in rabbits resulted in sustained, dose-dependent levels of levonorgestrel in plasma and cervical tissue for 90 days. Polyurethane caps placed between segments successfully prevented diffusion of levonorgestrel into the tenofovir-releasing segment during storage.Hydrated rings endured between 152 N and 354 N tensile load before failure during uniaxial extension testing. In summary, this system represents a significant advance in vaginal drug delivery technology, and is the first in a new class of long-acting multipurpose prevention drug delivery systems.
