En la enfermedad reumática con afectación mitral, la insuficiencia es la forma de presentación más frecuente en gente joven. La posibilidad de reparación quirúrgica en la insuficiencia reumática ...depende fundamentalmente de factores anatómicos de la válvula, como son la flexibilidad del velo anterior y la presencia de lesiones calcificadas a nivel del aparato subvalvular, pero también de la experiencia del centro en reparación mitral compleja. Todo ello hace que esta patología infradiagnosticada haya quedado relegada a la sustitución protésica, ya que en muchos casos es remitida de forma tardía con una calcificación avanzada. Con el fin de desmitificar esta entidad, en el siguiente artículo abordaremos la insuficiencia mitral reumática y su tratamiento con las técnicas específicas reparadoras, así como la presentación de nuestra experiencia y una discusión de la patología con revisión de la literatura publicada hasta la fecha.
In rheumatic disease with mitral involvement, regurgitation is the most common form of presentation in young people. The possibility of surgical repair in rheumatic regurgitation depends on anatomical factors of the valve, such as the flexibility of the anterior leaflet and the presence of calcified lesions at the level of the subvalvular apparatus, but also on the experience of the center in complex mitral repair. All this means that this underdiagnosed pathology has been relegated to prosthetic replacement, since in many cases it is remitted late with advanced calcification. In order to demystify this entity, in the following article we will address rheumatic mitral regurgitation and its treatment with specific repair techniques, as well as the presentation of our experience and a discussion of the pathology with a review of the literature.
Generalist versus Specialist Self‐Replicators Komáromy, Dávid; Monzón, Diego M.; Marić, Ivana ...
Chemistry : a European journal,
April 5, 2024, Letnik:
30, Številka:
20
Journal Article
Recenzirano
Odprti dostop
Darwinian evolution, including the selection of the fittest species under given environmental conditions, is a major milestone in the development of synthetic living systems. In this regard, ...generalist or specialist behavior (the ability to replicate in a broader or narrower, more specific food environment) are of importance. Here we demonstrate generalist and specialist behavior in dynamic combinatorial libraries composed of a peptide‐based and an oligo(ethylene glycol) based building block. Three different sets of macrocyclic replicators could be distinguished based on their supramolecular organization: two prepared from a single building block as well as one prepared from an equimolar mixture of them. Peptide‐containing hexamer replicators were found to be generalists, i. e. they could replicate in a broad range of food niches, whereas the octamer peptide‐based replicator and hexameric ethyleneoxide‐based replicator were proven to be specialists, i. e. they only replicate in very specific food niches that correspond to their composition. However, sequence specificity cannot be demonstrated for either of the generalist replicators. The generalist versus specialist nature of these replicators was linked to their supramolecular organization. Assembly modes that accommodate structurally different building blocks lead to generalist replicators, while assembly modes that are more restrictive yield specialist replicators.
Whether assembly‐driven self‐replicators that emerge from a mixture of two building blocks specialize on one resource or are generalists was found to depend on their supramolecular organization.
Gallic acid efficiently catalyses radical arylations in water-acetone at room temperature. This methodology proved to be versatile and scalable. Therefore, it constitutes a greener alternative to ...arylation. Moreover, considering that gallic acid is an abundant vegetable tannin, this work also unleashes an alternative method for the reutilisation of bio-wastes.
Transition metal-free oxidation with air at room temperature has been achieved by simply using ascorbate (vitamin C) and catalytic amounts of menadione (vitamin K3). A combination of the mentioned ...vitamins transforms atmospheric oxygen into hydrogen peroxide, which is able to oxidize arylboronic acids and other chemical moieties.
La cirugía del arco aórtico en neonatos ha pasado de la hipotermia profunda con paro circulatorio a la perfusión cerebral en 25°C. Un paso más supone la perfusión cerebral y miocárdica simultánea, ...facilitando la cirugía a corazón latiendo.
Una cánula en «Y» desde la línea arterial proporciona sangre oxigenada al cerebro y al corazón. El arco es reparado latiendo. A continuación se administra cardioplejía por raíz para la corrección intracardíaca. Sesenta y ocho pacientes son distribuidos en 3 grupos: a) Norwood (9 neonatos); b) arco aórtico (20 niños); y c) arco más afectación intracardíaca (39 pacientes). Cardiopatía asociada en el grupo c): comunicación interventricular (15), switch arterial (9), comunicación interauricular (6), cor triatriatum (3), comisurotomía aórtica (2), comprehensive repair (2), ostium primum (1) y Yasui (1). Catorce de los últimos pacientes recibieron una canulación adicional en la aorta descendente, alcanzando una perfusión corporal total.
El tiempo medio de circulación extracorpórea fue de 155minutos (63-353). La perfusión cerebral-miocárdica duró 36 minutos (18-60) y la isquemia miocárdica alcanzó 34 minutos (0-160), siendo de cero en el grupo «b». El seguimiento fue completo con una media de 52 meses (2-78). Cinco pacientes fallecieron y 3 precisaron angioplastia por recoartación.
La perfusión cerebral-miocárdica selectiva es factible y fácil de reconvertir a protección cardiopléjica convencional. Notablemente se reduce la isquemia miocárdica, siendo nula en casos de cirugía aislada del arco. Mediante la perfusión corporal total puede reducirse la morbilidad en cirugía neonatal del arco.
Aortic arch repair has shifted from deep hypothermia plus circulatory arrest to cerebral perfusion at tepid temperatures. A step forward is simultaneous brain-coronary perfusion, allowing beating-heart arch surgery.
A “Y” cannula from the arterial line delivers oxigenated blood to brain and heart. The arch is repaired on a beating heart at 25°C. Intracardiac repair is performed after running cardioplegia through the root line. 68 patients are classified into three groups. A: Norwood (9 neonates); B: aortic arch (20 children); C: aortic arch plus intracardiac repair (39 patients). Associated anomalies in group C: ventricular septal defect (15), arterial switch (9), atrial septal defect (6), cor triatriatum (3), aortic commissurotomy (2), comprehensive repair (2), ostium primum (1), Yasui (1). Fourteen lately patients had their descending aorta additionally cannulated to achieve a total body perfusion strategy.
Mean by-pass time was 155minutes (range 63-353). Mean brain-coronary perfusion was 36minutes (18-60). Mean coronary ischemia was 34minutes (0-160). The heart was not arrested in group B patients. Follow-up was complete for a mean of 52 months (2-78). Five patients died in the postop. Three requiered angioplasty for recoarctation.
Selective brain-coronary perfusion is feasible and easy to switch to conventional cardioplegia delivery. Coronary ischemia can be notably reduced, being even zero minutes in isolated arch surgery. Total body perfusion may reduce morbidity in neonatal arch surgery.
Cyclic products can be obtained through the intramolecular version of the Nicholas reaction, which requires having the nucleophile connected to the alkyne unit. Here, we report the synthesis of ...1-oxa-3-cyclooctynes starting from commercially available (1
,3
)-camphoric acid. The strategy is based on the initial preparation of propargylic alcohols, complexation of the triple bond with Co
(CO)
, and treatment with BF
·Et
O to induce an intramolecular Nicholas reaction with the free hydroxyl group as nucleophile. Finally, oxidative deprotection of the alkyne afforded the cyclooctynes in good yields. Notably, large-sized R substituents at the chiral center connected to the O atom were oriented in such a way that steric interactions were minimized in the cyclization, allowing the formation of cyclooctynes exclusively with
configuration, in good agreement with theoretical predictions. Moreover, preliminary studies demonstrated that these cyclooctynes were reactive in the presence of azides yielding substituted triazoles.
Estimar el flujo sanguíneo en intestino delgado e hígado mediante la administración de microesferas coloreadas en la aurícula izquierda, comparando dicha estimación con flujo continuo y flujo ...pulsátil, para confirmar o rechazar como causa del síndrome de Heyde la hipoperfusión e hipoxia en estos órganos atribuidos a la pérdida de la amplitud del pulso arterial.
Se utilizaron 22 cerdos minipig de ambos sexos con un peso 29,5±9,6 kg, implantándose 11 asistencias mecánicas circulatorias de flujo continuo y 11 de flujo pulsátil, monitorizados hemodinámica y analíticamente. La perfusión sanguínea en hígado e íleon terminal fue estimada mediante la administración de microesferas coloreadas en situación basal, a los 30 min de asistencia total y a los 30 min de asistencia parcial.
Los datos fueron referidos en tanto por ciento de la perfusión de estos órganos estimada en situación basal. Se realizó el estudio estadístico mediante el análisis de la varianza para medidas repetidas con una significación α de 0,05. En el hígado, el tipo asistencia (total o parcial), el tipo de bomba (continua o pulsátil) y la interacción entre ambas, arrojó la siguiente significación estadística: 0,518, 0,364 y 0,237, respectivamente. En el íleon terminal los resultados fueron: 0,264, 0,193 y 0,141.
Analíticamente se observaron diferencias significativas en el nivel de bilirrubina relacionadas con la bomba de flujo continuo, así como pH y urea.
No observamos diferencias significativas en la estimación de la perfusión en íleon ni hígado cuando comparamos asistencia mecánica circulatoria de flujo continuo y flujo pulsátil.
To estimate blood flow in the small intestine and liver by administration of coloured microspheres in the left atrium, comparing this estimate with continuous flow perfusion and pulsatile flow, in order to confirm or reject hypoperfusion and hypoxia in these organs attributed to loss of pulse amplitude as the cause of Heyde's syndrome.
Twenty-two minipig pigs of both sexes weighing 29.5±9.6kg were implanted with 11 continuous and 11 pulsatile mechanical circulatory assist devices were implanted in 22 minipig. Haemodynamic and analytic parameter were measured. Liver and terminal ileum blood perfusión was estimated by administration of stained microspheres previus to circulatory support, at 30minutes of full assist and at 30minutes of partial assist.
Data were reported as percent of estimated perfusion at baseline. The study was performed by analysis of variance for repeated measures with a significance α of 0.05. In the liver, type of assistance (total or partial), type of pump (continuous or pulsatile) and the interaction between the 2had the following statistical significance: 0.518. 0.364 and 0.237 respectively. In the terminal ileum the results were: 0.264. 0.193 and 0.141.
Analytically significant differences were observed in bilirubin level related to the continuous flow pump, as well as pH and urea.
We observed no significant differences in the estimation of perfusion in ileum and liver when comparing continuous flow and pulsatile flow CMA.
El músculo papilar gigante y de inserción anómala en la valva anterior de la válvula mitral es una presentación rara, pero con importante repercusión. La obstrucción del tracto de salida del ...ventrículo izquierdo de dicha anomalía, sumada a la presencia de miocardiopatía hipertrófica obstructiva tiene como consecuencia insuficiencia cardiaca. Este artículo es un reporte de caso de un paciente de 49 años con miocardiopatía hipertrófica obstructiva y sintomatología, a pesar de un tratamiento médico óptimo. El ecocardiograma transesofágico demostró engrosamiento septal asimétrico con grosor de 21mm, aceleración de flujo con interposición de un músculo papilar y SAM, que condicionaban insuficiencia mitral severa. La cardiorresonancia evidenció la inserción de un músculo papilar anterolateral aberrante en la valva anterior de la válvula mitral, que junto con el septo condicionaban una obstrucción severa. Se decidió intervención quirúrgica confirmándose la anatomía, y se procedió a la resección y amputación del músculo papilar aberrante y miectomía ampliada del septo interventricular, quedando una válvula mitral sin insuficiencia. Durante su estancia en la unidad postoperatoria el paciente no presentó ninguna complicación. Actualmente permanece sin insuficiencia mitral residual ni comunicación interventricular.
La miectomía estándar en este paciente dejaría obstrucción del tracto de salida, al mantener la interrupción al flujo secundaria a la presencia del músculo papilar mesoventricular. En conclusión, la miocardiopatía hipertrófica obstructiva con insuficiencia mitral secundaria asociada a la presencia de músculo papilar aberrante puede ser tratada de manera exitosa con resección septal, amputación papilar y sin realizar sustitución valvular mitral.
A giant and aberrant papillary muscle inserted in the anterior leaflet of the mitral valve is a rare presentation of obstructive hypertrophic myocardiopathy but with an important repercussion. The obstruction of the outflow tract of the left ventricle in addition with this giant and aberrant muscle has as a consequence the development of heart failure. The objective of this paper is to describe the diagnosis and surgical technique in a patient with this anatomic alteration and severe mitral regurgitation.
We present a case report of a 49 year old patient with symptomatic and progressive obstructive hypertrophic myocardiopathy despite medical treatment. In the transesophageal echocardiogram, asymmetrical thickening (21mm.) of the interventricular septum and acceleration of the outflow tract of the left ventricle with severe mitral regurgitation were observed in relationship with an aberrant papillary muscle. As well, in the cardiac magnetic resonance was observed that this aberrant and giant papillary muscle was inserted in the anterior leaflet of the mitral valve. Surgical treatment was decided and a resection and amputation of the aberrant papillary muscle and mitral repair were made. While recovering from the procedure, the patient didn’t present any complications. The patient remains without ventricular septal defect nor mitral regurgitation.
In this case, the standard myectomy would lead to obstruction of the outflow tract by maintaining the interruption of flow secondary to the presence of the mesoventricular papillary muscle. In conclusion, obstructive hypertrophic myocardiopathy and severe mitral regurgitation with the presence of aberrant papillary muscle, can be treated through septal resection, papillary amputation and without performing mitral valve replacement.
Las complicaciones mecánicas del infarto de miocardio hoy día son una entidad poco frecuente, sin embargo, su diagnóstico precoz y el manejo terapéutico adecuado resultan fundamentales para la ...supervivencia del paciente, que implican al médico de urgencias, el cardiólogo y el cirujano cardiaco. Una vez que existe sospecha de rotura cardiaca o pseudoaneurisma ventricular el traslado a quirófano debe ser rápido, donde con circulación extracorpórea y la técnica quirúrgica adecuada el paciente tiene opción de sobrevivir.
The mechanical complications of myocardial infarction today are a rare entity, however, early diagnosis and adequate therapeutic management are essential for patient survival, involving the emergency physician, cardiologist and cardiac surgeon. Once there is suspicion of cardiac rupture or ventricular pseudoaneurysm, the transfer to the operating room should be quick, where with extracorporeal circulation and the appropriate surgical technique the patient has the option of surviving.
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