In the pre-antiretroviral therapy (ART) era, markers of increased disease severity during an acut... more In the pre-antiretroviral therapy (ART) era, markers of increased disease severity during an acute opportunistic infection (OI) were associated with mortality. Even with ART, mortality remains high during the first year after an OI in persons with advanced HIV infection, but it is unclear whether previous predictors of mortality remain valid in the current era. To determine clinical and immunological predictors of death after an OI. We used clinical data and stored plasma from ACTG A5164, a multicenter study evaluating the optimal timing of ART during a nontuberculous OI. We developed Cox models evaluating associations between clinical parameters and plasma marker levels at entry and time to death over the first 48 weeks after the diagnosis of OI. We developed multivariable models incorporating only clinical parameters, only plasma marker levels, or both. The median CD4+ T-cell count in study participants at baseline was 29 cells/µL. Sixty-four percent of subjects had Pneumocystis j...
Proceedings of SPE Latin American and Caribbean Petroleum Engineering Conference, 2005
Sensa tube with fiber optic distributed temperature sensing (DTS) has provided useful real time i... more Sensa tube with fiber optic distributed temperature sensing (DTS) has provided useful real time information for Pemex in various wells through thermal analysis of distributed temperature data. Four case studies are presented in this paper: the first case corresponds to a water injection profile survey at a Northern project. The other cases are related to gas lift optimization in the Northern and Southern Mexican regions. As a part of the Pemex operated secondary recovery project in a Northern field, Fiber Optic Distributed Temperature Sensing technology has been used to monitor the water injection and warm-back temperature profiles across two perforated and fractured intervals, revealing the preferential flow into a one interval. The DTS thermal analysis provided important information to Pemex, which used the results as a guideline to take corrective action to increase the efficiency of their secondary oil recovery project. Pressure transient data was also collected to aid in the interpretation of the system using memory pressure gauges run on the fiber optic Sensa tube. The remaining case studies will demonstrate DTS gas lift systems optimization projects. One of these cases shows an example of an efficient gas lift system, meaning no need of post work-over well intervention. The other two case studies reveal issues with the gas lift system design, which compromised the lift efficiency and consequently the well productivity. Data acquisition using a portable fiber-optic Sensa tube unit has provided important information in a cost effective way. The DTS measurement provides a real-time and continuous temperature profile of the entire well, enabling the operator to monitor simultaneously all the gas lift valves, which is not possible to achieve with the usual time-consuming PLT surveys. Ultimately, the DTS monitoring has proven to be an efficient and reliable tool, saving the operator well intervention time and allowing immediate rectification of the issues observed.
Progress in Nuclear Magnetic Resonance Spectroscopy, 2014
Significant progress has been made over the last three decades in the field of NMR, a technique w... more Significant progress has been made over the last three decades in the field of NMR, a technique which has proven to have a variety of applications in many scientific disciplines, including nanotechnology. Herein we describe how NMR enables the characterization of nanosystems at different stages of their formation and modification (raw materials, bare or functionalized nanosystems), even making it possible to study in vivo nanoparticle interactions, thereby importantly contributing to nanoparticle design and subsequent optimization. Furthermore, the unique characteristics of nanosystems can open up new prospects for site-targeted, more specific contrast agents, contributing to the development of certain nuclear magnetic resonance applications such as MRI.
Here we report a new nanotechnology-based nasal vaccination concept intended to elicit both, spec... more Here we report a new nanotechnology-based nasal vaccination concept intended to elicit both, specific humoral and cellular immune responses. The concept relies on the use of a multifunctional antigen nanocarrier consisting of a hydrophobic nanocore, which can allocate lipophilic immunostimulants, and a polymeric corona made of chitosan (CS), intended to associate antigens and facilitate their transport across the nasal mucosa. The Toll-like receptor 7 (TLR7) agonist, imiquimod, and the recombinant hepatitis B surface antigen (HB), were selected as model molecules for the validation of the concept. The multifunctional nanocarriers had a nanometric size (around 200 nm), a high positive zeta potential (+45 mV) and a high antigen association efficiency (70%). They also exhibited the ability to enter macrophages in vitro and to effectively deliver the associated imiquimod intracellularly, as noted by the secretion of pro-inflammatory cytokines (i.e. IL-6 and TNF-α). However, the nanocarriers did not induce the in vitro activation of the complement cascade. Finally, the positive effect of the co-delivery of HB and imiquimod from the nanocapsules was evidenced upon intranasal administration to mice. The nanocapsules containing imiquimod elicited a protective immune response characterized by increasing IgG levels over time and specific immunological memory. Additionally, the levels of serum IgG subclasses (IgG1 and IgG2a) indicated a balanced cellular/humoral response, thus suggesting the capacity of the nanocapsules to modulate the systemic immune response upon nasal vaccination.
In the pre-antiretroviral therapy (ART) era, markers of increased disease severity during an acut... more In the pre-antiretroviral therapy (ART) era, markers of increased disease severity during an acute opportunistic infection (OI) were associated with mortality. Even with ART, mortality remains high during the first year after an OI in persons with advanced HIV infection, but it is unclear whether previous predictors of mortality remain valid in the current era. To determine clinical and immunological predictors of death after an OI. We used clinical data and stored plasma from ACTG A5164, a multicenter study evaluating the optimal timing of ART during a nontuberculous OI. We developed Cox models evaluating associations between clinical parameters and plasma marker levels at entry and time to death over the first 48 weeks after the diagnosis of OI. We developed multivariable models incorporating only clinical parameters, only plasma marker levels, or both. The median CD4+ T-cell count in study participants at baseline was 29 cells/µL. Sixty-four percent of subjects had Pneumocystis j...
Proceedings of SPE Latin American and Caribbean Petroleum Engineering Conference, 2005
Sensa tube with fiber optic distributed temperature sensing (DTS) has provided useful real time i... more Sensa tube with fiber optic distributed temperature sensing (DTS) has provided useful real time information for Pemex in various wells through thermal analysis of distributed temperature data. Four case studies are presented in this paper: the first case corresponds to a water injection profile survey at a Northern project. The other cases are related to gas lift optimization in the Northern and Southern Mexican regions. As a part of the Pemex operated secondary recovery project in a Northern field, Fiber Optic Distributed Temperature Sensing technology has been used to monitor the water injection and warm-back temperature profiles across two perforated and fractured intervals, revealing the preferential flow into a one interval. The DTS thermal analysis provided important information to Pemex, which used the results as a guideline to take corrective action to increase the efficiency of their secondary oil recovery project. Pressure transient data was also collected to aid in the interpretation of the system using memory pressure gauges run on the fiber optic Sensa tube. The remaining case studies will demonstrate DTS gas lift systems optimization projects. One of these cases shows an example of an efficient gas lift system, meaning no need of post work-over well intervention. The other two case studies reveal issues with the gas lift system design, which compromised the lift efficiency and consequently the well productivity. Data acquisition using a portable fiber-optic Sensa tube unit has provided important information in a cost effective way. The DTS measurement provides a real-time and continuous temperature profile of the entire well, enabling the operator to monitor simultaneously all the gas lift valves, which is not possible to achieve with the usual time-consuming PLT surveys. Ultimately, the DTS monitoring has proven to be an efficient and reliable tool, saving the operator well intervention time and allowing immediate rectification of the issues observed.
Progress in Nuclear Magnetic Resonance Spectroscopy, 2014
Significant progress has been made over the last three decades in the field of NMR, a technique w... more Significant progress has been made over the last three decades in the field of NMR, a technique which has proven to have a variety of applications in many scientific disciplines, including nanotechnology. Herein we describe how NMR enables the characterization of nanosystems at different stages of their formation and modification (raw materials, bare or functionalized nanosystems), even making it possible to study in vivo nanoparticle interactions, thereby importantly contributing to nanoparticle design and subsequent optimization. Furthermore, the unique characteristics of nanosystems can open up new prospects for site-targeted, more specific contrast agents, contributing to the development of certain nuclear magnetic resonance applications such as MRI.
Here we report a new nanotechnology-based nasal vaccination concept intended to elicit both, spec... more Here we report a new nanotechnology-based nasal vaccination concept intended to elicit both, specific humoral and cellular immune responses. The concept relies on the use of a multifunctional antigen nanocarrier consisting of a hydrophobic nanocore, which can allocate lipophilic immunostimulants, and a polymeric corona made of chitosan (CS), intended to associate antigens and facilitate their transport across the nasal mucosa. The Toll-like receptor 7 (TLR7) agonist, imiquimod, and the recombinant hepatitis B surface antigen (HB), were selected as model molecules for the validation of the concept. The multifunctional nanocarriers had a nanometric size (around 200 nm), a high positive zeta potential (+45 mV) and a high antigen association efficiency (70%). They also exhibited the ability to enter macrophages in vitro and to effectively deliver the associated imiquimod intracellularly, as noted by the secretion of pro-inflammatory cytokines (i.e. IL-6 and TNF-α). However, the nanocarriers did not induce the in vitro activation of the complement cascade. Finally, the positive effect of the co-delivery of HB and imiquimod from the nanocapsules was evidenced upon intranasal administration to mice. The nanocapsules containing imiquimod elicited a protective immune response characterized by increasing IgG levels over time and specific immunological memory. Additionally, the levels of serum IgG subclasses (IgG1 and IgG2a) indicated a balanced cellular/humoral response, thus suggesting the capacity of the nanocapsules to modulate the systemic immune response upon nasal vaccination.
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