Chromatographic purification of the plasmin-like enzyme from clamworm (Perinereis aibuhitensis Grub) and its fibrinolytic activity by metal ions.

In this study, fibrinolytic protease was isolated and purified from Perinereis aibuhitensis Grub, and the extraction process was optimized. The properties of the enzyme, such as the amino acid composition, thermal stability, optimal temperature, and pH, were investigated. After detoxification, proteins collected from fresh Clamworm (Perinereis aibuhitensis Grub) were concentrated via ammonium sulfate precipitation. The crude protease was purified using gel filtration resin (Sephadex G-100), anion exchange resin (DEAE-Sepharose FF), and hydrophobic resin (Phenyl Sepharose 6FF). The molecular weight of the protease was determined by polyacrylamide gel electrophoresis (SDS-PAGE). The optimum temperature and optimum pH of the protease were determined. The activity of crude protease in the 40-60% salt-out section was the highest, reaching 467.53 U/mg. The optimal process for purifying crude protein involved the application of DEAE-Sepharose FF and Phenyl Sepharose 6FF, which resulted in the isolation of a single protease known as Asp60-D1-P1 with the highest fibrinolytic activity; additionally, the enzyme activity was measured at 3367.76 U/mg. Analysis by Native-PAGE and SDS-PAGE revealed that the molecular weight of Asp60-D1-P1 was 44.5 kDa, which consisted of two subunits with molecular weights of 6.5 and 37.8 kDa, respectively. The optimum temperature for Asp60-D1-P1 was 40°C, and the optimal pH was 8.0.

Intoxicación por ácido acetilsalicílico, fisiopatología y manejo / Physiopathology and management of acetylsalicylic acid intoxication

Acetylsalicylic acid (ASA) intoxication is potentially lethal. After ingestion, AAS is rapidly transformed into salicylic acid that dissociates into an hydrogen ion plus salicylate. Salicylate is the main form of AAS in the body and produces multiple alterations. Initially, the stimulation of the ventilatory center promotes a respiratory alkalosis. Then, the mitochondrial dysfunction induced by salicylate, will generate a progressive metabolic acidosis due to the accumulation of ketoacids, lactic acid and dicarboxylic acids among others. Another alterations include hydro electrolytic disorders, gastrointestinal lesions, neurological involvement, ototoxicity and coagulopathy. The correct handling of acetylsalicylic acid intoxication requires an thorough knowledge of its pharmacokinetics and pharmacodynamics. Treatment consists in life support measures, gastric lavage, activated charcoal and urinary alkalization to promote the excretion of salicylates. In some occasions, it will be necessary to start renal replacement therapy as soon as possible.

Riesgo de sangrado en la colangiopancreatografía retrógrada endoscópica: impacto del uso de fármacos antitrombóticos / Bleeding risk in endoscopic retrograde cholangiopancreatography. Impact of the use of antithrombotic drugs

Objetivos: analizar los factores de riesgo de hemorragia en la colangiopancreatografía retrógrada endoscópica así como el impacto sobre la misma del uso de los fármacos antitrombóticos. Material y métodos: fuentes de datos: valoración de los artículos indexados en PubMed así como de los detectados en el análisis de la bibliografía de metaanálisis y revisiones. Criterios de elegibilidad del estudio, participantes e intervenciones: se valoraron los artículos por los abstracts y, al detectar los más significativos (principalmente ensayos clínicos aleatorizados y series de casos bien diseñadas), se analizaron los estudios completos. Métodos de evaluación del estudio y síntesis: para el análisis de la bibliografía y la elaboración de los diferentes niveles de evidencia se han utilizado los criterios establecidos por el Centro de Medicina Basada en Evidencia de Oxford. Resultados: se han encontrado 765 referencias, de las cuales 753 fueron obtenidas de la búsqueda en PubMed y Cochrane Library. Doce trabajos fueron seleccionados a partir del análisis de otros estudios publicados (revisiones sistemáticas, metaanálisis y guías clínicas). Después de analizar el título o el resumen de los estudios, fueron eliminados 655 trabajos. Definitivamente, se han incluido en el análisis final 83 ensayos clínicos o estudios descriptivos de calidad. Conclusiones: se han definido siete conclusiones con referencia a los factores de riesgo de sangrado y al impacto de los fármacos antitrombóticos (AU)

Aims: To analyze the risk factors for hemorrhage during endoscopic retrograde cholangiopancreatography and the impact of antithrombotic drugs. Material and methods: Data sources: papers indexed in PubMed have been reviewed, as well as those found during the analysis of the bibliography of meta-analysis and reviews. Selection criteria: the references have been firstly evaluated by review of the abstract. After selecting the most significant articles (mainly randomized trials and well-designed case series) these have been deeply analyzed. Evaluation of the studies and synthesis: criteria by the Oxford Centre for Evidence-Based Medicine have been used for the analysis of the references and elaboration of evidence levels. Results: Seven hundred and sixty-five references were found, 753 in PubMed and the Cochrane Library. Twelve studies were selected during the analysis of other published articles (systematic reviews, meta-analysis and clinical practice guidelines). After analyzing the title or the abstract, 655 studies were excluded. Finally, 83 high quality trials or descriptive studies have been included in the analysis. Conclusion: Seven conclusions regarding the risk factors for bleeding and the impact of antithrombotic drugs have been defined (AU)

Complicaciones de la nutrición parenteral pediátrica / Complications of pediatric parenteral nutrition

No disponible

Fibrinolytic protease production by new Streptomyces sp: DPUA 1576 from Amazon lichens

Background Streptomyces sp. DPUA 1576 from Amazon lichens was studied to protease and fibrinolytic production. A 2² factorial experimental design was applied to optimize its protease enzyme production using two independent variables, namely soybean flour and glucose concentrations. Results The optimal conditions to obtain high protease production (83.42 U/mL) were 1.26% soybean flour and 1.23% glucose concentration. A polynomial model was fitted to correlate the relationship between the two variables and protease activity. In relation to fibrinolytic activity, the highest activity of 706.5 mm² was obtained at 1.7% soybean flour and 1.0% glucose concentration, which was 33% higher than plasmin. Fibrinolytic production was not optimized in the studied conditions. Conclusions These results show that the optimization of the culture medium can enhance protease production, thus becoming a good process for further research. In addition, Streptomyces sp. DPUA 1576, isolated from Amazon lichens, might be a potential strain for fibrinolytic protease production.

¿Son útiles los antisecretores en el manejo de la hemorragia digestiva alta no varicosa? / Are anti-secretory drugs useful for the management of non-variceal upper gastrointestinal haemorrhage?

La hemorragia digestiva alta no varicosa supone la causa más importante de sangrado digestivo, siendo una consulta frecuente en los servicios de urgencias hospitalarios. El tratamiento médico basado en el uso de inhibidores de la bomba de protones (IBP), junto con el tratamiento endoscópico, ha demostrado disminuir de manera significativa las tasas de resangrado, mejorando la supervivencia de estos pacientes. Después de dos décadas desde la comercialización de los (IBP), a día de hoy sigue existiendo controversia en cuanto a su dosificación y forma de administración en los pacientes con hemorragia digestiva de origen péptico (AU)

Non-variceal upper gastrointestinal haemorrhage, is the most frequent cause of gastrointestinal bleeding and is a common presentation in emergency departments. Medical treatment based on the use of proton pump inhibitors (PPIs), together with endoscopic therapy, has been shown to significantly lower rates of rebleeding and improve survival in these patients. Two decades after the marketing of PPIs there is still controversy as to dosage and method of administration for patients with gastrointestinal bleeding of peptic origin (AU)

Tratamiento antitrombótico para la prevención del reinfarto tras la reperfusión: el precio del éxito / No disponible

No disponible

Mecanismo de acción de los fármacos antitrombóticos / Mechanism of action of antithrombotic drugs

Los fármacos antiplaquetarios y anticoagulantes desempeñan un papel fundamental en el tratamiento de los síndromes coronarios agudos, ya que la trombosis coronaria es el proceso que los desencadena. A su vez, el intervencionismo coronario percutáneo, el tratamiento de elección en un gran porcentaje de pacientes con este síndrome, supone también un potente estímulo para la activación de las plaquetas y de la coagulación. En este artículo se describe brevemente la activación y agregación plaquetarias y la activación de la coagulación. También se analizan los fármacos antitrombóticos utilizados en el intervencionismo coronario percutáneo y se describen sus mecanismos de acción, dosis, indicaciones y efectos secundarios, en pacientes con cardiopatía estable e inestable (AU)

Since acute coronary syndrome results from coronary thrombosis, antiplatelet and anticoagulant drugs play a fundamental role in its treatment. Moreover, percutaneous coronary intervention, the preferred form of treatment in a large percentage of patients with this syndrome, is also a potent stimulator of platelet activation and blood coagulation. In this article, the mechanisms of platelet adhesion and aggregation and of blood coagulation are reviewed briefly. In addition, there is also a review of the antithrombotic drugs used in percutaneous coronary intervention, which includes their mechanisms of action, dosages, indications, and side-effects in patients with both stable and unstable coronary artery disease (AU)

Drenaje de colecciones abscesificadas abdominales. Ventajas del uso de fibrinolíticos / Abdominal abscess drainage. Advantages of fibrinolytic agents

El drenaje percutáneo mediante catéter con guía de imagen es el tratamiento estándar de los abscesos abdominales. En muchos casos debería ser considerado el tratamiento de elección, pero hay circunstancias especiales que requieren otros tratamientos específicos. Los abscesos típicos localizados en órganos de parénquimas sólidos y en el seno del peritoneo son fácilmente diagnosticados por los diferentes medios de imagen y se pueden drenar de manera eficiente. Los abscesos múltiples, tabicados y grandes requieren una cuidadosa implantación de uno o varios catéteres. El manejo de catéteres requiere irrigación con suero para evitar su obstrucción. A pesar del uso adecuado de estas irrigaciones con suero y de que se utilicen catéteres grandes, en algunos casos falla el drenaje y es necesario recurrir a la cirugía convencional. En estos casos seleccionados donde ha fallado el drenaje convencional, los agentes fibrinolíticos han sido eficaces para acortar el tiempo de drenaje y la estancia hospitalaria. Hay controversia acerca del uso de fibrinolíticos en el drenaje de ciertas áreas anatómicas, como el páncreas y el bazo, por lo que se exige una selección cuidadosa de la técnica. La colaboración interdisciplinaria propicia el éxito. En este artículo se revisa el estado de la práctica con el uso de fibrinolíticos para mejorar el tratamiento percutáneo mediante catéter de abscesos abdominales (AU)

Image-guided percutaneous abscess drainage has become the standard method of treatment for most abdominal abscesses. In many cases, it should be considered the treatment of choice, but there are certain circumstances that require specific approaches and methods. Typical abscesses within solid parenchymal organs or those in the peritoneal spaces can be reliably detected by imaging techniques and efficiently drained. Abscesses that are multiple or long and circuitous require careful placement of one or more catheters. Management of the drainage catheters includes irrigation with saline solution to prevent obstruction. Despite the use of saline irrigations and large caliber catheters, catheter drainage sometimes fails and conventional surgery is required. In selected cases, fibrinolytic agents have been proved to be effective in shortening drainage times and length of hospital stay. The use of fibrinolytic agents in the drainage of some anatomical sites, such as the spleen and pancreas, is controversial and the technique should be meticulously selected. Successful treatment is most likely when an interdisciplinary approach is used. The present article reviews the state of the art of the use of fibrinolytic agents to improve percutaneous abdominal abscess drainage (AU)

Development of new heparin-like compounds and other antithrombotic drugs and their interaction with vascular endothelial cells

The anticlotting and antithrombotic activities of heparin, heparan sulfate, low molecular weight heparins, heparin and heparin-like compounds from various sources used in clinical practice or under development are briefly reviewed. Heparin isolated from shrimp mimics the pharmacological activities of low molecular weight heparins. A heparan sulfate from Artemia franciscana and a dermatan sulfate from tuna fish show a potent heparin cofactor II activity. A heparan sulfate derived from bovine pancreas has a potent antithrombotic activity in an arterial and venous thrombosis model with a negligible activity upon the serine proteases of the coagulation cascade. It is suggested that the antithrombotic activity of heparin and other antithrombotic agents is due at least in part to their action on endothelial cells stimulating the synthesis of an antithrombotic heparan sulfate.

A study of the interaction between Helicobacter pylori and components of the human fibrinolytic system

The interaction of plasminogen, tissue plasminogen activator (t-PA) and urokinase with a clinical strain of Helicobacter pylori was studied. Plasminogen bound to the surface of H. pylori cells in a concentration-dependent manner and could be activated to the enzymatic form, plasmin, by t-PA. Affinity chromatography assays revealed a plasminogen-binding protein of 58.9 kDa in water extracts of surface proteins. Surface-associated plasmin activity, detected with the chromogenic substrate CBS 00.65, was observed only when plasminogen and an exogenous activator were added to the cell suspension. The two physiologic plasminogen activators, t-PA and urokinase, were also shown to bind to and remain active on the surface of bacterial cells. epsilon-Aminocaproic acid caused partial inhibition of t-PA binding, suggesting that the kringle 2 structure of this activator is involved in the interaction with surface receptors. The activation of plasminogen by t-PA, but not urokinase, strongly depended on the presence of cells and a 25-fold enhancer effect on the initial velocity of activation by t-PA compared to urokinase was established. Furthermore, a relationship between cell concentration and the initial velocity of activation was demonstrated. These findings support the concept that plasminogen activation by t-PA on the bacterial surface is a surface-dependent reaction which offers catalytic advantages

Modulation of staphylokinase-dependent plasminogen activation by mono- and divalent ions

The effect of several ions (Cl-, Na+, K+, Ca2+) on the rate of plasminogen (Pg) activation by recombinant staphylokinase (rSTA) is reported. Both monovalent and divalent ions affect the rate at which Pg is activated by rSTA, in a concentration-dependent manner (range 0-100 mM). In almost all cases, a decrease of the initial velocity of activation was observed. Cl- showed the most striking inhibitory effect at low concentrations (64 percent at 10 mM). However, in the presence of a fibrin surface, this inhibition was attenuated to 38 percent. Surprisingly, 10 mM Ca2+ enhanced the Pg activation rate 21 percent when a polymerized fibrin matrix was present. These data support the idea that ions can modulate the rate of Pg activation through a mechanism that may be associated with changes in the molecular conformation of the zymogen. This effect is strongly dependent on the presence of a fibrin clot