Pretreatment with phenoxybenzamine attenuates the radial artery's vasoconstrictor response to α-adrenergic stimuli

AbstractBackgroundAlthough the radial artery bypass conduit has excellent intermediate-term patency, it has a proclivity to vasospasm. We tested the hypothesis that brief pretreatment of a radial artery graft with the irreversible adrenergic antagonist phenoxybenzamine attenuates the vasoconstrictor response to the vasopressors phenylephrine and norepinephrine compared with the currently used papaverine/lidocaine.MethodsSegments of human radial artery grafts were obtained after a 30-minute intraoperative pretreatment with a solution containing 20 mL of heparinized blood, 0.4 mL of papaverine (30 mg/mL), and 1.6 mL of lidocaine (1%). The segments were transported to the laboratory and placed into a bath containing Krebs-Henseleit solution and 10, 100, or 1000 μmol/L phenoxybenzamine or vehicle. The segments were tested in organ chambers for contractile responses to increasing concentrations of phenylephrine and norepinephrine (0.5-15 μmol/L).ResultsContractile responses to 15 μmol/L phenylephrine in control radial artery segments averaged 44.2% ± 9.1% of the maximal contractile response to 30 mmol/L KCl. Papaverine/lidocaine modestly attenuated contraction to 15 μmol/L phenylephrine (32.1% ± 5.9%; P = .22), but 1000 μmol/L phenoxybenzamine completely abolished radial artery contraction (−7.2% ± 4.4%; P < .001). The effect of 10 and 100 μmol/L phenoxybenzamine on attenuating vasocontraction was intermediate between 1000 μmol/L phenoxybenzamine and papaverine/lidocaine. Responses to 15 μmol/L norepinephrine in control radial artery segments averaged 54.7% ± 7.5% of maximal contraction to 30 mmol/L KCl. Papaverine/lidocaine modestly attenuated the contraction response of radial artery segments (35.6% ± 5.1%; P = .04). In contrast, 1000 μmol/L phenoxybenzamine showed the greatest attenuation of norepinephrine-induced contraction (−10.5% ± 2.0%; P < .001).ConclusionsA brief pretreatment of the human radial artery bypass conduit with 1000 μmol/L phenoxybenzamine completely attenuates the vasoconstrictor responses to the widely used vasopressors norepinephrine and phenylephrine. Papaverine/lidocaine alone did not block vasoconstriction to these α-adrenergic agonists

Holistic process development to mitigate proteolysis of a subunit rotavirus vaccine candidate produced in Pichia pastoris by means of an acid pH pulse during fed-batch fermentation.

To meet the challenges of global health, vaccine design and development must be reconsidered to achieve cost of goods as low as 15¢ per dose. A new recombinant protein-based rotavirus vaccine candidate derived from non-replicative viral subunits fused to a P2 tetanus toxoid CD4(+) T cell epitope is currently under clinical development. We have sought to simplify the existing manufacturing process to meet these aims. To this end, we have taken a holistic process development approach to reduce process complexity and costs while producing a product with the required characteristics. We have changed expression system from Escherichia coli to Pichia pastoris, to produce a secreted product, thereby reducing the number of purification steps. However, the presence of proteases poses challenges to product quality. To understand the effect of fermentation parameters on product quality small-scale fermentations were carried out. Media pH and fermentation duration had the greatest impact on the proportion of full-length product. A novel acidic pH pulse strategy was used to minimize proteolysis, and this combined with an early harvest time significantly increased the proportion of full-length material (60-75%). An improved downstream process using a combination of CIEX and AIEX to further reduce proteases, resulted in maintaining product quality (95% yield)

Plan de negocios de una plataforma digital que vincule a los prestadores de servicios veterinarios con los due?os de mascotas en distritos emergentes

En la presente tesis se defini? una plataforma digital que integre tanto a los usuarios quienes son due?os de mascotas (demanda) y a los clientes quienes son proveedores de productos y/o servicios (oferta) como una soluci?n viable para mejorar la experiencia de los amantes de mascotas y satisfacer ese mercado que presenta un crecimiento constante en los ?ltimos a?os. Con esta soluci?n los due?os de mascotas (conscientes del cuidado que necesitan los ?engre?dos de casa?) tendr?n una mayor visibilidad de ofertas. Como parte del estudio para determinar la viabilidad del modelo de negocio se desarroll? una investigaci?n de mercado a trav?s de entrevistas a expertos, referentes del sector, y encuestas al p?blico objetivo de los distritos de Jes?s Mar?a, Lince, Pueblo Libre, San Miguel, Surquillo y Bre?a. Con el enfoque de ofrecer una experiencia ?nica y de valor tanto a los usuarios due?os de mascotas y clientes proveedores, nace ?BuscaPatas? enfoc?ndose en un modelo ?Ecommerce? y con la oportunidad de escalar y hacer sostenible el negocio a trav?s de una gesti?n que integre de manera eficiente la estrategia digital, los canales de comunicaci?n, canales de marketing y que aproveche la tecnolog?a para garantizar la operaci?n del modelo de negocio, satisfacer altamente a los clientes y garantizar una rentabilidad en las operaciones

Resistance to autosomal dominant Alzheimer's disease in an APOE3 Christchurch homozygote: a case report.

We identified a PSEN1 (presenilin 1) mutation carrier from the world's largest autosomal dominant Alzheimer's disease kindred, who did not develop mild cognitive impairment until her seventies, three decades after the expected age of clinical onset. The individual had two copies of the APOE3 Christchurch (R136S) mutation, unusually high brain amyloid levels and limited tau and neurodegenerative measurements. Our findings have implications for the role of APOE in the pathogenesis, treatment and prevention of Alzheimer's disease

Engaging stakeholders across a socio-environmentally diverse network of water research sites in North and South America

Maintaining and restoring freshwater ecosystem services in the face of local and global change requires adaptive research that effectively engages stakeholders. However, there is a lack of understanding and consensus in the research community regarding where, when, and which stakeholders should be engaged and what kind of researcher should do the engaging (e.g., physical, ecological, or social scientists). This paper explores stakeholder engagement across a developing network of aquatic research sites in North and South America with wide ranging cultural norms, social values, resource management paradigms, and eco-physical conditions. With seven sites in six countries, we found different degrees of engagement were explained by differences in the interests of the stakeholders given the history and perceived urgency of water resource problems as well as differences in the capacities of the site teams to effectively engage given their expertise and resources. We categorized engagement activities and applied Hurlbert and Gupta's split ladder of participation to better understand site differences and distill lessons learned for planning comparative socio-hydrological research and systematic evaluations of the effectiveness of stakeholder engagement approaches. We recommend research networks practice deliberate engagement of stakeholders that adaptively accounts for variations and changes in local socio-hydrologic conditions. This, in turn, requires further efforts to foster the development of well-integrated research teams that attract and retain researchers from multiple social science disciplines and enable training on effective engagement strategies for diverse conditions

Engaging stakeholders across a socio-environmentally diverse network of water research sites in North and South America

Maintaining and restoring freshwater ecosystem services in the face of local and global change requires adaptive research that effectively engages stakeholders. However, there is a lack of understanding and consensus in the research community regarding where, when, and which stakeholders should be engaged and what kind of researcher should do the engaging (e.g., physical, ecological, or social scientists). This paper explores stakeholder engagement across a developing network of aquatic research sites in North and South America with wide ranging cultural norms, social values, resource management paradigms, and eco-physical conditions. With seven sites in six countries, we found different degrees of engagement were explained by differences in the interests of the stakeholders given the history and perceived urgency of water resource problems as well as differences in the capacities of the site teams to effectively engage given their expertise and resources. We categorized engagement activities and applied Hurlbert and Gupta's split ladder of participation to better understand site differences and distill lessons learned for planning comparative socio-hydrological research and systematic evaluations of the effectiveness of stakeholder engagement approaches. We recommend research networks practice deliberate engagement of stakeholders that adaptively accounts for variations and changes in local socio-hydrologic conditions. This, in turn, requires further efforts to foster the development of well-integrated research teams that attract and retain researchers from multiple social science disciplines and enable training on effective engagement strategies for diverse conditions.Fil: Smyth, Robyn L.. Bard College; Estados UnidosFil: Fatima, Uroosa. Bard College; Estados UnidosFil: Segarra, Monique. Bard College; Estados UnidosFil: Borre, Lisa. Cary Institute of Ecosystem Studies; Estados UnidosFil: Zilio, Mariana Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Económicas y Sociales del Sur. Universidad Nacional del Sur. Departamento de Economía. Instituto de Investigaciones Económicas y Sociales del Sur; ArgentinaFil: Reid, Brian. Universidad Austral de Chile; ChileFil: Pincetl, Stephanie. Institute of the Environment and Sustainability; Estados UnidosFil: Astorga, Anna. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Económicas y Sociales del Sur. Universidad Nacional del Sur. Departamento de Economía. Instituto de Investigaciones Económicas y Sociales del Sur; ArgentinaFil: Huamantinco Cisneros, María Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Geografía y Turismo; ArgentinaFil: Conde, Sergio Daniel. Universidad de la República; UruguayFil: Harmon, Thomas Christopher. University of California Merced; Estados UnidosFil: Hoyos, Natalia. Universidad del Norte; ColombiaFil: Escobar, Jaime. Universidad del Norte; Colombia. Smithsonian Tropical Research Institute; PanamáFil: Lozoya, Juan Pablo. Universidad de la República; UruguayFil: Perillo, Gerardo Miguel E.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Nacional del Sur. Departamento de Geología; ArgentinaFil: Piccolo, Maria Cintia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Nacional del Sur. Departamento de Geografía y Turismo; ArgentinaFil: Rusak, James A.. Dorset Environmental Science Centre; Canadá. Queens University; CanadáFil: Velez, Maria I.. University of Regina; Canad

Uncoupling the structure–activity relationships of β2 adrenergic receptor ligands from membrane binding

Ligand binding to membrane proteins may be significantly influenced by the interaction of ligands with the membrane. In particular, the microscopic ligand concentration within the membrane surface solvation layer may exceed that in bulk solvent, resulting in overestimation of the intrinsic protein−ligand binding contribution to the apparent/measured affinity. Using published binding data for a set of small molecules with the β2 adrenergic receptor, we demonstrate that deconvolution of membrane and protein binding contributions allows for improved structure−activity relationship analysis and structure-based drug design. Molecular dynamics simulations of ligand bound membrane protein complexes were used to validate binding poses, allowing analysis of key interactions and binding site solvation to develop structure−activity relationships of β2 ligand binding. The resulting relationships are consistent with intrinsic binding affinity (corrected for membrane interaction). The successful structure-based design of ligands targeting membrane proteins may require an assessment of membrane affinity to uncouple protein binding from membrane interactions