Bicuspid Aortic Valve in 2 Model Species and Review of the Literature.

Bicuspid aortic valve (BAV) is the most common human congenital cardiac malformation. Although the etiology is unknown for most patients, formation of the 2 main BAV anatomic types (A and B) has been shown to rely on distinct morphogenetic mechanisms. Animal models of BAV include 2 spontaneous hamster strains and 27 genetically modified mouse strains. To assess the value of these models for extrapolation to humans, we examined the aortic valve anatomy of 4340 hamsters and 1823 mice from 8 and 7 unmodified strains, respectively. In addition, we reviewed the literature describing BAV in nonhuman mammals. The incidences of BAV types A and B were 2.3% and 0.03% in control hamsters and 0% and 0.3% in control mice, respectively. Hamsters from the spontaneous model had BAV type A only, whereas mice from 2 of 27 genetically modified strains had BAV type A, 23 of 27 had BAV type B, and 2 of 27 had both BAV types. In both species, BAV incidence was dependent on genetic background. Unlike mice, hamsters had a wide spectrum of aortic valve morphologies. We showed interspecific differences in the occurrence of BAV between humans, hamsters, and mice that should be considered when studying aortic valve disease using animal models. Our results suggest that genetic modifiers play a significant role in both the morphology and incidence of BAV. We propose that mutations causing anomalies in specific cardiac morphogenetic processes or cell lineages may lead to BAV types A, B, or both, depending on additional genetic, environmental, and epigenetic factors.

Myosin heavy chain isoforms in the myocardium of the atrioventricular junction of Scyliorhinus canicula (Chondrichthyes, Carcharhiniformes).

The atrioventricular junction of the fish heart, namely the segment interposed between the single atrium and the single ventricle, has been studied anatomically and histologically in several chondrichthyan and teleost species. Nonetheless, knowledge about myosin heavy chain (MyHC) in the atrioventricular myocardium remains scarce. The present report is the first one to provide data on the MyHC isoform distribution in the myocardium of the atrioventricular junction in chondrichthyans, specifically in the lesser spotted dogfish, Scyliorhinus canicula, a shark species whose heart reflects the primitive cardiac anatomical design in gnathostomes. Hearts from five dogfish were examined using histochemical and immunohistochemical techniques. The anti-MyHC A4.1025 antibody was used to detect differences in the occurrence of MyHC isoforms in the dogfish, as the fast-twitch isoforms MYH2 and MYH6 have a higher affinity for this antibody than the slow-twitch isoforms MYH7 and MYH7B. The histochemical findings show that myocardium of the atrioventricular junction connects the trabeculated myocardium of the atrium with the trabeculated layer of the ventricular myocardium. The immunohistochemical results indicate that the distribution of MyHC isoforms in the atrioventricular junction is not homogeneous. The atrial portion of the atrioventricular myocardium shows a positive reactivity against the A4.1025 antibody similar to that of the atrial myocardium. In contrast, the ventricular portion of the atrioventricular junction is not labelled, as is the case with the ventricular myocardium. This dual condition suggests that the myocardium of the atrioventricular junction has two contraction patterns: the myocardium of the atrial portion contracts in line with the atrial myocardium, whereas that of the ventricular portion follows the contraction pattern of the ventricular myocardium. Thus, the transition of the contraction wave from the atrium to the ventricle may be established in the atrioventricular segment because of its heterogeneous MyHC isoform distribution. The findings support the hypothesis that a distinct MyHC isoform distribution in the atrioventricular myocardium enables a synchronous contraction of inflow and outflow cardiac segments in vertebrates lacking a specialized cardiac conduction system.

Linkage to care strategy for the micro-elimination of hepatitis C among parenteral drug users on methadone replacement therapy in Gipuzkoa.

INTRODUCTION: parenteral drug users (PDUs) are a population with a high prevalence of infection with the hepatitis C virus (HCV) and significant difficulties to access to treatment. Opioid replacement therapy programs regularly monitor these individuals. OBJECTIVE: to effectively treat this population using a directly observed therapy (DOT) and bringing resources closer to the methadone dispensing center in Gipuzkoa (Bitarte). METHODS: all methadone users that were positive for anti-HCV antibodies were included in the study. Using a simplified circuit, a hepatologist visits the center with a Fibroscan® device and requests treatment following assessment. Treatment is dispensed at the addict center, under the supervision of a psychiatrist and nursing staff. Prevalence, population characteristics and circuit effectiveness were assessed. RESULTS: Bitarte monitors 660 individuals. Of these, 73.6 % were positive for antibodies against HCV. The prevalence of viremic infection is 62.5 %. The predominant genotype was 1a, followed by 3. A total of 38.5 % had advanced fibrosis (F3 and F4) and 38 % of users admitted to active heroin use. In all, 82.07 % (174/212) of the population received treatment and 97 % had sustained viral response (SVR) after 12 weeks. No re-infections were recorded. CONCLUSIONS: the prevalence of viremic HCV infection among PDUs under treatment with methadone is 62 %. The linkage to care strategy was effective and > 80 % of the population with an active infection have been treated so far.

Differential expression of myosin heavy chain isoforms in cardiac segments of gnathostome vertebrates and its evolutionary implications.

BACKGROUND: Immunohistochemical studies of hearts from the lesser spotted dogfish, Scyliorhinus canicula (Chondrichthyes) revealed that the pan-myosin heavy chain (pan-MyHC) antibody MF20 homogeneously labels all the myocardium, while the pan-MyHC antibody A4.1025 labels the myocardium of the inflow (sinus venosus and atrium) but not the outflow (ventricle and conus arteriosus) cardiac segments, as opposed to other vertebrates. We hypothesized that the conventional pattern of cardiac MyHC isoform distribution present in most vertebrates, i.e. MYH6 in the inflow and MYH7 in the outflow segments, has evolved from a primitive pattern that persists in Chondrichthyes. In order to test this hypothesis, we conducted protein detection techniques to identify the MyHC isoforms expressed in adult dogfish cardiac segments and to assess the pan-MyHC antibodies reactivity against the cardiac segments of representative species from different vertebrate groups. RESULTS: Western and slot blot results confirmed the specificity of MF20 and A4.1025 for MyHC in dogfish and their differential reactivity against distinct myocardial segments. HPLC-ESI-MS/MS and ESI-Quadrupole-Orbitrap revealed abundance of MYH6 and MYH2 in the inflow and of MYH7 and MYH7B in the outflow segments. Immunoprecipitation showed higher affinity of A4.1025 for MYH2 and MYH6 than for MYH7 and almost no affinity for MYH7B. Immunohistochemistry showed that A4.1025 signals are restricted to the inflow myocardial segments of elasmobranchs, homogeneous in all myocardial segments of teleosts and acipenseriforms, and low in the ventricle of polypteriforms. CONCLUSIONS: The cardiac inflow and outflow segments of the dogfish show predominance of fast- and slow-twitch MyHC isoforms respectively, what can be considered a synapomorphy of gnathostomes. The myocardium of the dogfish contains two isomyosins (MYH2 and MYH7B) not expressed in the adult heart of other vertebrates. We propose that these isomyosins lost their function in cardiac contraction during the evolution of gnathostomes, the later acquiring a regulatory role in myogenesis through its intronic miRNA. Loss of MYH2 and MYH7B expression in the heart possibly occurred before the origin of Osteichthyes, being the latter reacquired in polypteriforms. We raise the hypothesis that the slow tonic MYH7B facilitates the peristaltic contraction of the conus arteriosus of fish with a primitive cardiac anatomical design and of the vertebrate embryo.

The prion protein inhibits monocytic cell migration by stimulating ß1 integrin adhesion and uropod formation.

The broad tissue distribution and evolutionary conservation of the glycosylphosphatidylinositol (GPI)-anchored prion protein (PrP, also known as PRNP) suggests that it plays a role in cellular homeostasis. Given that integrin adhesion determines cell behavior, the proposed role of PrP in cell adhesion might underlie the various in vitro and in vivo effects associated with PrP loss-of-function, including the immune phenotypes described in PrP(-/-) mice. Here, we investigated the role of PrP in the adhesion and (transendothelial) migration of human (pro)monocytes. We found that PrP regulates ß1-integrin-mediated adhesion of monocytes. Additionally, PrP controls the cell morphology and migratory behavior of monocytes: PrP-silenced cells show deficient uropod formation on immobilized VCAM and display bleb-like protrusions on the endothelium. Our data further show that PrP regulates ligand-induced integrin activation. Finally, we found that PrP controls the activation of several proteins involved in cell adhesion and migration, including RhoA and its effector cofilin, as well as proteins of the ERM family. We propose that PrP modulates ß1 integrin adhesion and migration of monocytes through RhoA-induced actin remodeling mediated by cofilin, and through the regulation of ERM-mediated membrane-cytoskeleton linkage.

Unusual anatomical origins of the coronary arteries in C57BL/6 mice. Are they strain-specific?

A previous manuscript [Fernández B, et al. (2008) J Anat 212, 12] reported on the unusual coronary artery patterns in mice belonging to the C57BL/6 strain. The aim here was to elucidate whether this pattern is unique to C57BL/6 mice or appears in other laboratory mouse strains and in wild-living mice. Stereomicroscopy, scanning electron microscopy, light microscopy and a corrosion cast technique were used to examine 597 adult mice belonging to three inbred strains (C57BL/6, Balb/c, DBA/2), three outbred stocks (CD1, OF1, NMRI) two hybrid lines (129sv × BL/6, CD2F1) and wild mice. It was shown that lock-like ostium is an exclusive trait of C57BL/6 mice, whereas left septal artery, accessory ostium, high take-off, intramural course and solitary ostium in aorta are all present in the different laboratory strains and wild mice included in the present study. However, each mouse population shows a specific incidence of these coronary conditions. Several clinically relevant human coronary artery anomalies are present in healthy mice from different strains that may serve as animal models for humans. These results should be taken into consideration in research concerning the murine coronary system, especially in coronary artery occlusion experiments and in studies on cardiovascular developmental biology using murine mutant lines.

STXBP1 promotes Weibel-Palade body exocytosis through its interaction with the Rab27A effector Slp4-a.

Vascular endothelial cells contain unique rod-shaped secretory organelles, called Weibel-Palade bodies (WPBs), which contain the hemostatic protein von Willebrand factor (VWF) and a cocktail of angiogenic and inflammatory mediators. We have shown that the Rab27A effector synaptotagmin-like protein 4-a (Slp4-a) plays a critical role in regulating hormone-evoked WPB exocytosis. Using a nonbiased proteomic screen for targets for Slp4-a, we now identify syntaxin-binding protein 1 (STXBP1) and syntaxin-2 and -3 as endogenous Slp4-a binding partners in endothelial cells. Coimmunoprecipitations showed that STXBP1 interacts with syntaxin-2 and -3, but not with syntaxin-4. Small interfering RNA-mediated silencing of STXBP1 expression impaired histamine- and forskolin-induced VWF secretion. To further substantiate the role of STXBP1, we isolated blood outgrowth endothelial cells (BOECs) from an early infantile epileptic encephalopathy type 4 (EIEE4) patient carrying a de novo mutation in STXBP1. STXBP1-haploinsufficient EIEE4 BOECs contained similar numbers of morphologically normal WPBs compared with control BOECs of healthy donors; however, EIEE4 BOECs displayed significantly impaired histamine- and forskolin-stimulated VWF secretion. Based on these findings, we propose that the Rab27A-Slp4-a complex on WPB promotes exocytosis through an interaction with STXBP1, thereby controlling the release of vaso-active substances in the vasculature.

Structure and vascularization of the ventricular myocardium in Holocephali: their evolutionary significance.

It was generally assumed that the ventricle of the primitive vertebrate heart was composed of trabeculated, or spongy, myocardium, supplied by oxygen-poor luminal blood. In addition, it was presumed that the mixed ventricular myocardium, consisting of a compacta and a spongiosa, and its supply through coronary arteries appeared several times throughout fish evolution. Recent work has suggested, however, that a fully vascularized, mixed myocardium may be the primitive condition in gnathostomes. The present study of the heart ventricles of four holocephalan species aimed to clarify this controversy. Our observations showed that the ventricular myocardium of Chimaera monstrosa and Harriotta raleighana consists of a very thin compacta overlying a widespread spongiosa. The ventricle of Hydrolagus affinis is composed exclusively of trabeculated myocardium. In these three species there is a well-developed coronary artery system. The main coronary artery trunks run along the outflow tract, giving off subepicardial ventricular arteries. The trabeculae of the spongiosa are irrigated by branches of the subepicardial arteries and by penetrating arterial vessels arising directly from the main coronary trunks at the level of the conoventricular junction. The ventricle of Rhinochimaera atlantica has only spongy myocardium supplied by luminal blood. Small coronary arterial vessels are present in the subepicardium, but they do not enter the myocardial trabeculae. The present findings show for the first time that in a wild living vertebrate species, specifically H. affinis, an extensive coronary artery system supplying the whole cardiac ventricle exists in the absence of a well-developed compact ventricular myocardium. This is consistent with the notion derived from experimental work that myocardial cell proliferation and coronary vascular growth rely on distinct developmental programs. Our observations, together with data in the literature on elasmobranchs, support the view that the mixed ventricular myocardium is primitive for chondrichthyans. The reduction or even lack of compacta in holocephali has to be regarded as a derived anatomical trait. Our findings also fit in with the view that the mixed myocardium was the primitive condition in gnathostomes, and that the absence of compact ventricular myocardium in different actinopterygian groups is the result of a repeated loss of such type of cardiac muscle during fish evolution.

Quadricuspid aortic valves in Syrian hamsters and their formation according to current knowledge on valvulogenesis.

Occurrence of quadricuspid aortic valves has been reported in humans, in nine dogs and in a greater white-toothed shrew. Moreover, two cases of developing aortic valves with four anticipated leaflets have been described in Syrian hamster embryos. Currently, however, no case of quadricuspid aortic valve in adult hamsters has been recorded. The aim here is to present four adults of this rodent species, two of them with unequivocally quadricuspid aortic valves and the other two with quadricuspid-like aortic valves. The four anomalous aortic valves were detected among 4,190 Syrian hamsters examined in our laboratory, representing an incidence of 0.09%. None of the affected hamsters showed apparent signs of disease. The present findings are considered on the light of current empirical knowledge about the morphogenesis of quadricuspid and bicuspid aortic and pulmonary valves. Quadricuspid aortic valves result from the partition of one of the normal mesenchymal cushions which normally give rise to normal (tricuspid) valves, while quadricuspid-like valves might be the product of a combined mechanism of fusion and partition of the cushions at the onset of the valvulogenesis. The presence of aortic valves with four leaflets in ancient mammalian lineages such as insectivors and rodents suggest that quadricuspid aortic valves, although showing almost certainly a low incidence, may be widespread among the different groups of mammals, including domestic animals.

[Summary: International consensus statement on nomenclature and classification of the congenital bicuspid aortic valve and its aortopathy, for clinical, surgical, interventional and research purposes]. / Resumen: Consenso internacional para la nomenclatura y clasificación de la válvula aórtica bicúspide congénita y su aortopatía, con fines clínicos, quirúrgicos, intervencionistas y de investigación.

This consensus of nomenclature and classification for congenital bicuspid aortic valve and its aortopathy is evidence-based and intended for universal use by physicians (both pediatricians and adults), echocardiographers, advanced cardiovascular imaging specialists, interventional cardiologists, cardiovascular surgeons, pathologists, geneticists, and researchers spanning these areas of clinical and basic research. In addition, as long as new key and reference research is available, this international consensus may be subject to change based on evidence-based data1.

Este consenso de nomenclatura y clasificación para la válvula aórtica bicúspide congénita y su aortopatía está basado en la evidencia y destinado a ser utilizado universalmente por médicos (tanto pediatras como de adultos), médicos ecocardiografistas, especialistas en imágenes avanzadas cardiovasculares, cardiólogos intervencionistas, cirujanos cardiovasculares, patólogos, genetistas e investigadores que abarcan estas áreas de investigación clínica y básica. Siempre y cuando se disponga de nueva investigación clave y de referencia, este consenso internacional puede estar sujeto a cambios de acuerdo con datos basados en la evidencia1.

The Epac-Rap1 signaling pathway controls cAMP-mediated exocytosis of Weibel-Palade bodies in endothelial cells.

Endothelial cells contain specialized storage organelles called Weibel-Palade bodies (WPBs) that release their content into the vascular lumen in response to specific agonists that raise intracellular Ca(2+) or cAMP. We have previously shown that cAMP-mediated WPB release is dependent on protein kinase A (PKA) and involves activation of the small GTPase RalA. Here, we have investigated a possible role for another PKA-independent cAMP-mediated signaling pathway in the regulation of WPB exocytosis, namely the guanine nucleotide exchange factor Epac1 and its substrate, the small GTPase Rap1. Epinephrine stimulation of endothelial cells leads to Rap1 activation in a PKA-independent fashion. siRNA-mediated knockdown of Epac1 abolished epinephrine-induced activation of Rap1 and resulted in decreased epinephrine-induced WPB exocytosis. Down-regulation of Rap1 expression and prevention of Rap1 activation through overexpression of Rap1GAP effectively reduced epinephrine- but not thrombin-induced WPB exocytosis. Taken together, these data uncover a new Epac-Rap1-dependent pathway by which endothelial cells can regulate WPB exocytosis in response to agonists that signal through cAMP.

The F-BAR domain protein PACSIN2 associates with Rac1 and regulates cell spreading and migration.

The Rac1 GTPase controls cytoskeletal dynamics and is a key regulator of cell spreading and migration mediated by signaling through effector proteins, such as the PAK kinases and the Scar and WAVE proteins. We previously identified a series of regulatory proteins that associate with Rac1 through its hypervariable C-terminal domain, including the Rac1 activator ß-Pix (also known as Rho guanine-nucleotide-exchange factor 7) and the membrane adapter caveolin-1. Here, we show that Rac1 associates, through its C-terminus, with the F-BAR domain protein PACSIN2, an inducer of membrane tubulation and a regulator of endocytosis. We show that Rac1 localizes with PACSIN2 at intracellular tubular structures and on early endosomes. Active Rac1 induces a loss of PACSIN2-positive tubular structures. By contrast, Rac1 inhibition results in an accumulation of PACSIN2-positive tubules. In addition, PACSIN2 appears to regulate Rac1 signaling; siRNA-mediated loss of PACSIN2 increases the levels of Rac1-GTP and promotes cell spreading and migration in a wound healing assay. Moreover, ectopic expression of PACSIN2 reduces Rac1-GTP levels in a fashion that is dependent on the PACSIN2-Rac1 interaction, on the membrane-tubulating capacity of PACSIN2 and on dynamin. These data identify the BAR-domain protein PACSIN2 as a Rac1 interactor that regulates Rac1-mediated cell spreading and migration.

Proteomic screen identifies IGFBP7 as a novel component of endothelial cell-specific Weibel-Palade bodies.

Vascular endothelial cells contain unique storage organelles, designated Weibel-Palade bodies (WPBs), that deliver inflammatory and hemostatic mediators to the vascular lumen in response to agonists like thrombin and vasopressin. The main component of WPBs is von Willebrand factor (VWF), a multimeric glycoprotein crucial for platelet plug formation. In addition to VWF, several other components are known to be stored in WPBs, like osteoprotegerin, monocyte chemoattractant protein-1 and angiopoetin-2 (Ang-2). Here, we used an unbiased proteomics approach to identify additional residents of WPBs. Mass spectrometry analysis of purified WPBs revealed the presence of several known components such as VWF, Ang-2, and P-selectin. Thirty-five novel candidate WPB residents were identified that included insulin-like growth factor binding protein-7 (IGFBP7), which has been proposed to regulate angiogenesis. Immunocytochemistry revealed that IGFBP7 is a bona fide WPB component. Cotransfection studies showed that IGFBP7 trafficked to pseudo-WPB in HEK293 cells. Using a series of deletion variants of VWF, we showed that targeting of IGFBP7 to pseudo-WPBs was dependent on the carboxy-terminal D4-C1-C2-C3-CK domains of VWF. IGFBP7 remained attached to ultralarge VWF strings released upon exocytosis of WPBs under flow. The presence of IGFBP7 in WPBs highlights the role of this subcellular compartment in regulation of angiogenesis.

Focal-adhesion targeting links caveolin-1 to a Rac1-degradation pathway.

Directional cell migration is crucially dependent on the spatiotemporal control of intracellular signalling events. These events regulate polarized actin dynamics, resulting in protrusion at the front of the cell and contraction at the rear. The actin cytoskeleton is regulated through signalling by Rho-like GTPases, such as RhoA, which stimulates myosin-based contractility, and CDC42 and Rac1, which promote actin polymerization and protrusion. Here, we show that Rac1 binds the adapter protein caveolin-1 (Cav1) and that Rac1 activity promotes Cav1 accumulation at Rac1-positive peripheral adhesions. Using Cav1-deficient mouse fibroblasts and depletion of Cav1 expression in human epithelial and endothelial cells mediated by small interfering RNA and short hairpin RNA, we show that loss of Cav1 induces an increase in Rac1 protein and its activated, GTP-bound form. Cav1 controls Rac1 protein levels by regulating ubiquitylation and degradation of activated Rac1 in an adhesion-dependent fashion. Finally, we show that Rac1 ubiquitylation is not required for effector binding, but regulates the dynamics of Rac1 at the periphery of the cell. These data extend the canonical model of Rac1 inactivation and uncover Cav1-regulated polyubiquitylation as an additional mechanism to control Rac1 signalling.

Factors other than genotype account largely for the phenotypic variation of the pulmonary valve in Syrian hamsters.

Understanding of the aetiology of congenitally anomalous pulmonary valves remains incomplete. The aim of our study, therefore, was to elucidate the degree to which the phenotypic variation known to exist for the pulmonary valve relies on genotypic variation. Initially, we tested the hypothesis that genetically alike individuals would display similar valvar phenotypes if the phenotypic arrangement depended entirely, or almost entirely, on the genotype. Thus, we examined pulmonary valves from 982 Syrian hamsters belonging to two families subject to systematic inbreeding by crossing siblings. Their coefficient of inbreeding was 0.999 or higher, so they could be considered genetically alike. External environmental factors were standardized as much as possible. A further 97 Syrian hamsters from an outbred colony were used for comparative purposes. In both the inbred and outbred hamsters, we found valves with a purely trifoliate, or tricuspid, design, trifoliate valves with a more or less extensive fusion of the right and left leaflets, bifoliate, or bicuspid, valves with fused right and left leaflets, with or without a raphe located in the conjoined arterial sinus, and quadrifoliate, or quadricuspid, valves. The incidence of the different valvar morphological variants was similar in the outbred and inbred colonies, except for the bifoliate pulmonary valves, which were significantly more frequent in the hamsters from one of the two inbred families. Results of crosses between genetically alike hamsters revealed no significant association between the pulmonary valvar phenotypes as seen in the parents and their offspring. The incidence of bifoliate pulmonary valves, nonetheless, was higher than statistically expected in the offspring of crosses where at least one of the parents possessed a pulmonary valve with two leaflets. Our observations are consistent with the notion that the basic design of the pulmonary valve, in terms of whether it possesses three or two leaflets, relies on genotypic determinants. They also denote that the bifoliate condition of the valve is the consequence of complex inheritance, with reduced penetrance and variable expressivity. Moreover, in showing that the incidence of the bifoliate pulmonary valve significantly differs in two different isogenetic backgrounds, our data suggest that genetic modifiers might be implicated in directing the manifestation of such specific pulmonary valvar malformations. Finally, our findings indicate that factors other than the genotype, operating during embryonic life and creating developmental noise, or random variation, play a crucial role in the overall phenotypic variation involving the pulmonary valve.

Genetically alike Syrian hamsters display both bifoliate and trifoliate aortic valves.

The bifoliate, or bicuspid, aortic valve (BAV) is the most frequent congenital cardiac anomaly in man. It is a heritable defect, but its mode of inheritance remains unclear. Previous studies in Syrian hamsters showed that BAVs with fusion of the right and left coronary leaflets are expressions of a trait, the variation of which takes the form of a phenotypic continuum. It ranges from a trifoliate valve with no fusion of the coronary leaflets to a bifoliate root devoid of any raphe. The intermediate stages are represented by trifoliate valves with fusion of the coronary aortic leaflets, and bifoliate valves with raphes. The aim of this study was to elucidate whether the distinct morphological variants rely on a common genotype, or on different genotypes. We examined the aortic valves from 1 849 Syrian hamsters belonging to a family subjected to systematic inbreeding by full-sib mating. The incidence of the different trifoliate aortic valve (TAV) and bifoliate aortic valve (BAV) morphological variants widely varied in the successive inbred generations. TAVs with extensive fusion of the leaflets, and BAVs, accounted for five-sixths of the patterns found in Syrian hamsters considered to be genetically alike or virtually isogenic, with the probability of homozygosity being 0.999 or higher. The remaining one-sixth hamsters had aortic valves with a tricuspid design, but in most cases the right and left coronary leaflets were slightly fused. Results of crosses between genetically alike hamsters, with the probability of homozygosity being 0.989 or higher, revealed no significant association between the valvar phenotypes in the parents and their offspring. Our findings are consistent with the notion that the BAVs of the Syrian hamster are expressions of a quantitative trait subject to polygenic inheritance. They suggest that the genotype of the virtually isogenic animals produced by systematic inbreeding greatly predisposes to the development of anomalous valves, be they bifoliate, or trifoliate with extensive fusion of the leaflets. We infer that the same underlying genotype may account for the whole range of valvar morphological variants, suggesting that factors other than genetic ones are acting during embryonic life, creating the so-called intangible variation or developmental noise, and playing an important role in the definitive anatomic configuration of the valve. The clinical implication from our study is that congenital aortic valves with a trifoliate design, but with fusion of coronary aortic leaflets, may harbour the same inherent risks as those already recognised for BAVs with fusion of right and left coronary leaflets.

Sunlight intensity based global positioning system for near-surface underwater sensors.

Water monitoring is important in domains including documenting climate change, weather prediction and fishing. This paper presents a simple and energy efficient localization strategy for near surface buoy based sensors. Sensors can be dropped randomly in the ocean and thus self-calibrate in terms of geographic location such that geo-tagged observations of water quality can be made without the need for costly and energy consuming GPS-hardware. The strategy is based on nodes with an accurate clock and light sensors that can regularly sample the level of light intensity. The measurements are fitted into a celestial model of the earth motion around the sun. By identifying the trajectory of the sun across the skies one can accurately determine sunrise and sunset times, and thus extract the longitude and latitude of the sensor. Unlike previous localization techniques for underwater sensors, the current approach does not rely on stationary or mobile reference points.

Experimental evidence of the genetic hypothesis on the etiology of bicuspid aortic valve aortopathy in the hamster model.

Bicuspid aortopathy occurs in approximately 50% of patients with bicuspid aortic valve (BAV), the most prevalent congenital cardiac malformation. Although different molecular players and etiological factors (genetic and hemodynamic) have been suggested to be involved in aortopathy predisposition and progression, clear etiophysiopathological mechanisms of disease are still missing. The isogenic (genetically uniform) hamster (T) strain shows 40% incidence of BAV, but aortic dilatations have not been detected in this model. We have performed comparative anatomical, histological and molecular analyses of the ascending aorta of animals with tricuspid aortic valve (TAV) and BAV from the T strain (TTAV and TBAV, respectively) and with TAV from a control strain (HTAV). Aortic diameter, smooth muscle apoptosis, elastic waviness, and Tgf-ß and Fbn-2 expression were significantly increased in T strain animals, regardless of the valve morphology. Strain and aortic valve morphology did not affect Mmp-9 expression, whereas Mmp-2 transcripts were reduced in BAV animals. eNOS protein amount decreased in both TBAV and TTAV compared to HTAV animals. Thus, histomorphological and molecular alterations of the ascending aorta appear in a genetically uniform spontaneous hamster model irrespective of the aortic valve morphology. This is a direct experimental evidence supporting the genetic association between BAV and aortic dilatation. This model may represent a population of patients with predisposition to BAV aortopathy, in which increased expression of Tgf-ß and Fbn-2 alters elastic lamellae structure and induces cell apoptosis mediated by eNOS. Patients either with TAV or BAV with the same genetic defect may show the same risk to develop bicuspid aortopathy.

The Medical versus Zoological Concept of Outflow Tract Valves of the Vertebrate Heart.

The anatomical elements that in humans prevent blood backflow from the aorta and pulmonary artery to the left and right ventriclesare the aortic and pulmonary valves, respectively. Each valve regularly consists of three leaflets (cusps), each supported by its valvular sinus. From the medical viewpoint, each set of three leaflets and sinuses is regarded as a morpho-functional unit. This notion also applies to birds and non-human mammals. However, the structures that prevent the return of blood to the heart in other vertebrates are notably different. This has led to discrepancies between physicians and zoologists in defining what a cardiac outflow tract valve is. The aim here is to compare the gross anatomy of the outflow tract valvular system among several groups of vertebrates in order to understand the conceptual and nomenclature controversies in the field.

Risk Factors of DAIR Failure and Validation of the KLIC Score: A Multicenter Study of Four Hundred Fifty-Five Patients.

Background: Debridement, antibiotic agents, and implant retention (DAIR) is a currently accepted approach for the treatment of early prosthetic joint infections (PJI). The success of a DAIR procedure has shown variable results throughout the published literature. Scoring systems such as the Kidney, Liver, Index surgery, Cemented prosthesis, and C-reactive protein value (KLIC) score for the selection of patients that are likely to benefit from DAIR have proved to be helpful in decision making. Our study aims to further validate the KLIC score using a large external multicentric cohort and to evaluate other risk factors for failure. Patients and Methods: A retrospective analysis of patients with an early acute PJI who were treated with DAIR and recorded in a database of eight Spanish university hospitals was performed. According to pre-operative variables of the KLIC study, patients were categorized into five groups: group A, ≤2 points; group B, 2.5-3.5 points; group C, 4-5 points; group D, 5.5-6.5 points; and group E, ≥7 points. Failure rates were compared between groups at 60 days and after 60 days of DAIR. Further variables for risk of failure were also analyzed. Results: A total of 455 patients with early acute PJI were included in the analyses. At 60 days, patients presenting with pre-operative elevated C-reactive protein serum levels, Staphylococcus aureus, and polymicrobial infections were associated with failure. Failure rates recorded were 12% for group A (n = 210), 18% for group B (n = 83), 26% for group C (n = 89), 24% for group D (n = 66), and 0% for group E (n = 7). Univariable analysis between consecutive groups of the KLIC score showed no differences for failure before 60 days of the DAIR procedure. Scheduled surgery and having the procedure performed by a specialized unit were also identified as important factors for DAIR success. Conclusions: Our results suggest the KLIC score was not useful for predicting failure in our cohort. Furthermore, our results indicate a specialized unit should conduct DAIR procedures.