6 research outputs found
Defining the Biological Identity of the Unborn: A Scientific Approach to The Human Zygote
The humanity (or lack thereof) of the zygote is one of the most prevalent and fundamental questions in science now. Past the philosophical, moral, ethical and legal objections and implications behind this issue, the question of the humanity of the unborn is at its most fundamental level a scientific one. After all, human beings are simply rational animals, whose reproductive processes we understand now better than ever. This paper will serve as an insight into dealing with the often controversial and politically-charged topic of the unborn from a purely scientific perspective
Experience in Spain with the first patients in home hemodialysis treated with low-flow dialysate monitors
La hemodiálisis domiciliaria (HDD) con monitores de bajo flujo de líquido de diálisis ha ganado popularidad en los últimos años gracias a su sencillez de diseño, portabilidad y capacidad de desplazamiento. No obstante, existen dudas respecto a la adecuación que este tipo de técnica ofrece, pues utiliza monitores con baño a flujos bajos y lactato. El objetivo de este estudio fue demostrar los beneficios clínicos de la HDD con el monitor NxStage System One® introducido recientemente en España. Presentamos los resultados de un estudio observacional, retrospectivo que incluyó de manera no seleccionada a los primeros pacientes con HDD corta mediante este monitor en 12 centros en España. Se analizó la evolución clínica de 86 pacientes a 0, 6 y 12 meses, incluyendo datos relacionados con la prescripción, evolución de parámetros analíticos de dosis de diálisis, anemia, metabolismo óseo-mineral, evolución de la diuresis residual, utilización de fármacos y datos relacionados con permanencia en la técnica, y causas de salida a lo largo del seguimiento. Pudimos demostrar que este monitor proporcionó una adecuada dosis de diálisis, con tasa óptima de ultrafiltración, con mejoría de los principales marcadores bioquímicos de adecuación en diálisis. El uso de esta técnica se asoció con una disminución de antihipertensivos, captores del fósforo y agentes eritropoyéticos, observándose, además, muy buenos resultados de supervivencia tanto del paciente como de la técnica. La sencillez de este monitor unida a sus buenos resultados clínicos debería facilitar el crecimiento y utilización de la HDD, tanto en pacientes incidentes como prevalentes
Rational Design and Characterization of D-Phe-Pro-D-Arg-Derived Direct Thrombin Inhibitors
The tremendous social and economic impact of thrombotic disorders, together with the considerable risks associated to the currently available therapies, prompt for the development of more efficient and safer anticoagulants. Novel peptide-based thrombin inhibitors were identified using in silico structure-based design and further validated in vitro. The best candidate compounds contained both l- and d-amino acids, with the general sequence d-Phe(P3)-Pro(P2)-d-Arg(P1)-P1′-CONH2. The P1′ position was scanned with l- and d-isomers of natural or unnatural amino acids, covering the major chemical classes. The most potent non-covalent and proteolysis-resistant inhibitors contain small hydrophobic or polar amino acids (Gly, Ala, Ser, Cys, Thr) at the P1′ position. The lead tetrapeptide, d-Phe-Pro-d-Arg-d-Thr-CONH2, competitively inhibits α-thrombin's cleavage of the S2238 chromogenic substrate with a Ki of 0.92 µM. In order to understand the molecular details of their inhibitory action, the three-dimensional structure of three peptides (with P1′ l-isoleucine (fPrI), l-cysteine (fPrC) or d-threonine (fPrt)) in complex with human α-thrombin were determined by X-ray crystallography. All the inhibitors bind in a substrate-like orientation to the active site of the enzyme. The contacts established between the d-Arg residue in position P1 and thrombin are similar to those observed for the l-isomer in other substrates and inhibitors. However, fPrC and fPrt disrupt the active site His57-Ser195 hydrogen bond, while the combination of a P1 d-Arg and a bulkier P1′ residue in fPrI induce an unfavorable geometry for the nucleophilic attack of the scissile bond by the catalytic serine. The experimental models explain the observed relative potency of the inhibitors, as well as their stability to proteolysis. Moreover, the newly identified direct thrombin inhibitors provide a novel pharmacophore platform for developing antithrombotic agents by exploring the conformational constrains imposed by the d-stereochemistry of the residues at positions P1 and P1′
Experiencia en España con los primeros pacientes en hemodiálisis domiciliaria tratados con monitores de bajo flujo de líquido de diálisis
Home hemodialysis (HHD) with low-flow dialysate devices has gained popularity in recent years due to its simple design, portability, and ability to provide greater freedom of movement for our patients. However, there are doubts about the adequacy that this technology offers, since it uses monitors with low-flow bath and lactate. The aim of this study was to demonstrate the clinical benefits of low-flow HHD with the NxStage System One® recently introduced in Spain. We present the results of an observational, retrospective cohort study that included the first patients who started short daily HHD with this device in 12 Spanish centers. We analyzed the evolution of 86 patients at 0, 6 and 12 months, including data related to prescription, and evolution of biochemical parameters related to dialysis dose, anemia, mineral-bone metabolism; evolution of residual renal function, medication usage, and causes of withdrawal during the followup. We were able to demonstrate that this NxStage System One® monitor, in patients with HHD, have provided an adequate dialysis dose, with optimal ultrafiltration rate, with improvement of main biochemical markers of dialysis adequacy. The usage of this technique was associated to a decrease of antihypertensive drugs, phosphate binders and erythropoietin agents, with very good results both patient and technique survival. The simplicity of the technique, together with its good clinical outcomes, should facilitate the growth and utilization of HHD, both in incident and prevalent patients.La hemodiálisis domiciliaria (HDD) con monitores de bajo flujo de líquido de diálisis ha ganado popularidad en los últimos años gracias a su sencillez de diseño, portabilidad y capacidad de desplazamiento. No obstante, existen dudas respecto a la adecuación que este tipo de técnica ofrece, pues utiliza monitores con baño a flujos bajos y lactato. El objetivo de este estudio fue demostrar los beneficios clínicos de la HDD con el monitor NxStage System One® introducido recientemente en España. Presentamos los resultados de un estudio observacional, retrospectivo que incluyó de manera no seleccionada a los primeros pacientes con HDD corta mediante este monitor en 12 centros en España. Se analizó la evolución clínica de 86 pacientes a 0, 6 y 12 meses, incluyendo datos relacionados con la prescripción, evolución de parámetros analíticos de dosis de diálisis, anemia, metabolismo óseo-mineral, evolución de la diuresis residual, utilización de fármacos y datos relacionados con permanencia en la técnica, y causas de salida a lo largo del seguimiento. Pudimos demostrar que este monitor proporcionó una adecuada dosis de diálisis, con tasa óptima de ultrafiltración, con mejoría de los principales marcadores bioquímicos de adecuación en diálisis. El uso de esta técnica se asoció con una disminución de antihipertensivos, captores del fósforo y agentes eritropoyéticos, observándose, además, muy buenos resultados de supervivencia tanto del paciente como de la técnica. La sencillez de este monitor unida a sus buenos resultados clínicos debería facilitar el crecimiento y utilización de la HDD, tanto en pacientes incidentes como prevalentes
Experience in Spain with the first patients in home hemodialysis treated with low-flow dialysate monitors Experiencia en España con los primeros pacientes en hemodiálisis domiciliaria tratados con monitores de bajo flujo de líquido de diálisis
Home hemodialysis (HHD) with low-flow dialysate devices has gained popularity in recent years due to its simple design, portability, and ability to provide greater freedom of movement for our patients. However, there are doubts about the adequacy that this technology offers, since it uses monitors with low-flow bath and lactate. The aim of this study was to demonstrate the clinical benefits of low-flow HHD with the NxStage System One® recently introduced in Spain. We present the results of an observational, retrospective cohort study that included the first patients who started short daily HHD with this device in 12 Spanish centers. We analyzed the evolution of 86 patients at 0, 6 and 12 months, including data related to prescription, and evolution of biochemical parameters related to dialysis dose, anemia, mineral-bone metabolism; evolution of residual renal function, medication usage, and causes of withdrawal during the followup. We were able to demonstrate that this NxStage System One® monitor, in patients with HHD, have provided an adequate dialysis dose, with optimal ultrafiltration rate, with improvement of main biochemical markers of dialysis adequacy. The usage of this technique was associated to a decrease of antihypertensive drugs, phosphate binders and erythropoietin agents, with very good results both patient and technique survival. The simplicity of the technique, together with its good clinical outcomes, should facilitate the growth and utilization of HHD, both in incident and prevalent patients