P67 195. Cirugía del tromboembolismo pulmonar masivo en el enfermo crítico

La extracción de los trombos pulmonares en el tromboembolismo pulmonar masivo antes de 1953 (operación de Trendelenburg) cosechó fracaso tras fracaso. Desde el advenimiento de la circulación extracorpórea (CEC) el porcentaje de éxito de esta operación mejoró notablemente, no habiendo dejado de aumentar hasta la actualidad, existiendo series que reflejan porcentajes de hasta el 94% de supervivencia inmediata, con 86 y 83% de supervivencia actuarial a 1 y 3años.Presentamos un caso de paciente varón de 35años sin enfermedad previa ni antecedentes familiares de enfermedad tromboembólica. Consulta por insuficiencia respiratoria, siendo diagnosticado por tomografía computarizada de tromboembolismo en AP izquierda, la cual ocluye. El ECO-Doppler de MMII descarta trombosis venosa profunda (TVP). Una nueva tomografía computarizada informa de persistencia de la obstrucción de AP izquierda y sus ramas, que parece haber aumentado. En ecocardiografía transtorácica (ETT) dilatación de cavidades derechas con función de ventrículo derecho (VD) normal y presión sistólica de la arteria pulmonar (PSAP) de 70 mmHg. Los estudios para investigar trombofilia fueron negativos.Tras unos días empeora su situación, produciéndose dos paradas cardiorrespiratorias, de las que es reanimado y tratado inmediatamente con TNK. La tomografía computarizada muestra la existencia de nuevo episodio de tromboembolismo pulmonar que afecta a la AP derecha gravemente.Es intervenido quirúrgicamente bajo CEC sin parada circulatoria, extrayéndose molde trombótico de tronco y ambas ramas de la AP. La evolución postoperatoria fue favorable. En tomografía computarizada de control se observan limpios el tronco y las ramas de la AP, con cierto compromiso en ramas subsegmentarias de la AP izquierda.Se muestran imágenes de la intervención y tomografía computarizada pre y posquirúrgicas

Early Stage Biomineralization in the Periostracum of the ‘Living Fossil’ Bivalve Neotrigonia

A detailed investigation of the shell formation of the palaeoheterodont ‘living fossil’ Neotrigonia concentrated on the timing and manufacture of the calcified ‘bosses’ which stud the outside of all trigonioid bivalves (extant and fossil) has been conducted. Electron microscopy and optical microscopy revealed that Neotrigonia spp. have a spiral-shaped periostracal groove. The periostracum itself is secreted by the basal cell, as a thin dark pellicle, becoming progressively transformed into a thin dark layer by additions of secretions from the internal outer mantle fold. Later, intense secretion of the internal surface of the outer mantle fold forms a translucent layer, which becomes transformed by tanning into a dark layer. The initiation of calcified bosses occurred at a very early stage of periostracum formation, deep within the periostracal groove immediately below the initialmost dark layer. At this stage, they consist of a series of polycyclically twinned crystals. The bosses grow as the periostracum traverse through the periostracal groove, in coordination with the thickening of the dark periostracal layer and until, upon reaching the mantle edge, they impinge upon each other and become transformed into large prisms separated by dark periostracal walls. In conclusion, the initial bosses and the external part of the prismatic layer are fully intraperiostracal. With later growth, the prisms transform into fibrous aggregates, although the details of the process are unknown. This reinforces the relationships with other groups that have the ability to form intraperiostracal calcifications, for example the unionoids with which the trigonioids form the clade Paleoheterodonta. The presence of similar structures in anomalodesmatans and other euheterodonts raises the question of whether this indicates a relationship or represents a convergence. The identification of very early calcification within an organic sheet has interesting implications for our understanding of how shells may have evolved.Coordinated Research Projects CGL2010-20748-C02-01 (AGC, EMH) and 02 (CS) (DGI, Spanish MICINN); the Research Group RNM363 (Consejería de Economía, Investigación, Ciencia y Empleo, Junta de Andalucía); and the FP7 COST Action TD0903 of the European Community

Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

EFFECTS OF LIGAMENT PRETENSION ON THE BIOMECHANICS OF THE KNEE: A FINITE ELEMENT ANALYSIS

INTRODUCTION A large number of finite element models have been developed to study the behaviour of the knee joint under different loading conditions. They have been used to study knee ligament function, knee prosthesis design and ligament reconstruction procedures. The terms pretension or prestrain of a knee ligament refer to the strain in the ligament when the joint is at full extension and little is known about its influence on the kinematics of the joint. In knee models, the ligament reference strains are usually merely estimated [1] and sometimes adapted by means of trial and error in order to get better agreement with experimental dat

Effects of ligament pretension on the biomechanics of the knee: a finite element analysis

A large number of finite element models have been developed to study the behaviour of the knee joint under different loading conditions. They have been used to study knee ligament function, knee prosthesis design and ligament reconstruction procedures. The terms pretension or prestrain of a knee ligament refer to the strain in the ligament when the joint is at full extension and little is known about its influence on the kinematics of the joint. In knee models, the ligament reference strains are usually merely estimated [1] and sometimes adapted by means of trial and error in order to get better agreement with experimental data [2]. As a consequence, very different values can be found in the literature. The purpose of this study was to analyze how ligament prestrains can affect the kinematics of the knee predicted with a FE model

Alignment of crystallographic <i>c</i>-axis throughout the four distinct microstructural layers of the oyster <i>Crassostrea gigas</i>

The superimposed layers of the true oyster shell have distinct morphology. The shells are mainly calcitic, comprising an outer prismatic region and inner foliated structure that is frequently interrupted by lenses of chalky calcitic deposits. Aragonite is restricted to the myostracum and ligament. Electron backscatter diffraction (EBSD) analysis has shown that despite the variations in structural morphology, the mineralized layers of the oyster shell maintain a single crystallographic orientation with the crystallographic c-axis orientated perpendicular to outer and inner shell surfaces. Varying crystal morphology, while maintaining crystallographic unity, may be an evolutionary trait that forms a crack-resistant shell with optimum strength and flexibility