Endocardial-mesenchymal transition underlies fusion of the conotruncal ridges during embryonic cardiac outflow tract septation

The embryonic cardiac outflow tract (conotruncus) is a single tubular chamber that connects the right ventricle with the aortic arch arteries. It contains two opposite, long and helical mesenchymal cushions covered by endocardial cells (conotruncal ridges). Conotruncal division (septation) gives rise to the adult right and left outflows together with the aortic and pulmonary valves. It takes place by fusion of the two opposite ridges and formation of the conotruncal septum. Although the participation of neural crest cells in septation is well established, the mechanism of fusion of the conotruncal ridges remains unknown. Defects in fusion have been shown to produce bicuspid aortic valve, the most prevalent human congenital cardiac malformation, in a hamster model. Three fusion mechanisms have been proposed to operate during embryonic development: epithelial adhesion, epithelial apoptosis and epithelial-mesenchymal transition (EMT). The first mechanism entails the expression of adhesion molecules and the maintenance of the identity of cells in contact, whereas in the other two, epithelial cells covering the fusing structures disappear by apoptosis or by transforming into mesenchymal cells. The objective of this study is to elucidate the mechanism involved in the fusion of the conotruncal ridges. Immunofluorecence techniques were used in ED 11-12 hamster embryos. The results indicate that the mechanism of EMT, but not epithelial adhesion or apoptosis, is involved in the process of fusion of the conotruncal ridges. The EMT mechanism associated with conotruncal septation seems to be uncoupled from the process of formation of the endocardial cushions, which takes place at early stages. With these results, we can raise the hypothesis that defects in the EMT process may lead to different morphological types of bicuspid aortic valve.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. This study was supported by P10-CTS-6068 (Junta de Andalucía), CGL2014-52356-P and CGL2017-85090-P (Ministerio de Economía y Competitividad), contract UMAJI75 (Junta de Andalucía, European Social Fund), and Universidad de Málaga

Is the bulbus arteriosus of fish homologous to the mamalian intrapericardial thoracic arteries?

El resumen aparece en el Program & Abstracts of the 10th International Congress of Vertebrate Morphology, Barcelona 2013.Anatomical Record, Volume 296, Special Feature — 1: P-089.Two major findings have significantly improved our understanding of the embryology and evolution of the arterial pole of the vertebrate heart (APVH): 1) a new embryonic presumptive cardiac tissue, named second heart field (SHF), forms the myocardium of the outflow tract, and the walls of the ascending aorta (AA) and the pulmonary trunk (PT) in mammals and birds; 2) the bulbus arteriosus (BA), previously thought to be an actinopterygian apomorphy, is present in all basal Vertebrates, and probably derives from the SHF. We hypothesized that the intrapericardial portions of the AA and the PT of mammals are homologous to the BA of basal vertebrates. To test this, we performed 1) a literature review of the anatomy and embryology of the APVH; 2) novel anatomical, histomorphological, and embryological analyses of the APVH, comparing basal (Galeus atlanticus), with apical (Mus musculus and Mesocricetus auratus) vertrebrates. Evidence obtained: 1) Anatomically, BA, AA, and PT are muscular tubes into the pericardial cavity, which connect the distal myocardial outflow tracts with the aortic arch system. Coronary arteries run through or originate at these anatomical structures; 2) Histologically, BA, AA, and PT show an inner layer of endothelium covered by circumferentially oriented smooth muscle cells, collagen fibers, and lamellar elastin. The histomorphological differences between the BA and the ventral aorta parallel those between intrapericardial and extrapericardial great arteries; 3) Embryologically, BA, AA, and PT are composed of smooth muscle cells derived from the SHF. They show a similar mechanism of development: incorporation of SHF‐derived cells into the pericardial cavity, and distal‐to‐proximal differentiation into an elastogenic cell linage. In conclusion, anatomical, histological and embryological evidence supports the hypothesis that SHF is a developmental unit responsible for the formation of the APVH. The BA and the intrapericardial portions of the great arteries must be considered homologous structures.Proyecto P10-CTS-6068 (Junta de Andalucía); proyecto CGL-16417 (Ministerio de Ciencia e Innovación); Fondos FEDER

Chamber specific expression of Myosin heavy chain 7b in the heart of vertebrates

In extant vertebrates, myosin heavy chain (MyHC) 6 and 7 are the main isoforms of atrial and ventricular myocardium respectively, whereas MyHC7b has been proposed to be an ancient cardiac isoform only expressed during embryonic development in modern species. In preliminary immunohistochemical studies of the heart of the lesser spotted dogfish (Scyliorhinus canicula; Chondrichthyes), we have observed that while MF20 labels homogeneously all the myocardium, A4.1025 labels the inflow cardiac segments (sinus venosus and atrium) but not the outflow segments (ventricle and conus arteriosus). In order to interpret these results, we have performed western and slot blots from samples of dogfish and hamster (Mesocricetus auratus) hearts, HPLC-ESI-MS/MS from dogfish samples, and immunohistochemistry in hearts of representative species of vertebrates, namely elasmobranchs, polypteriforms, acipenseriforms, teleosts and mammals, using MF20 and A4.1025 antibodies. Western and slot blot results confirmed the specificity of MF20 and A4.1025 for MyHC in dogfish, as well as their differential reactivity against different myocardial segments. HPLC-ESI-MS/MS using protein databases from Callorhinchus milii (Chondrichthyes) and Chordata revealed the presence of MyHC6 and 7 in all the dogfish myocardial segments, and of MyHC7b only in the outflow segments. Immunohistochemistry showed that while MF20 signals were homogeneous in all the myocardial segments of all the species studied, A4.1025 signals were restricted to the inflow myocardial segments in elasmobranchs, homogeneous in teleosts and acipenseriforms, and low in the ventricle of polypteriforms. It can be inferred that the A4.1025 antibody, as opposed to MF20, has a low affinity for MyHC7b, at least in the dogfish. In addition, we show that MyHC distribution in the cardiac chambers has changed during the evolution of gnathostomes.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.Study supported by grants CGL2017-85090-P and CGL2014-52356-P (Ministerio de Economía y Competitividad), FPU15/03209 (Ministerio de Educación, Cultura y Deporte), contract UMAJI75 (Junta de Andalucía, European Social Found), FEDER and Universidad de Málaga

Myocardial trabeculation in embryos of Scyliorhinus canicula (Elasmobranchii, Chondrichthyans)

Currently, three types of ventricular myoarchitecture are recognized in vertebrates, namely compact, spongy (trabeculated) and mixed myocardium. Mixed myocardium, which has been recently proposed as the primitive condition in gnathostomes, is composed of two myocardial layers: an inner trabeculated and an outer compact one. The trabeculation process has been studied in teleosts, showing exclusively spongy myocardium, and mammals and birds, characterized by a compact myocardial ventricular wall. In zebrafish, mouse and chicken embryos, the trabeculae develop as luminal myocardial ridges protruding into the lumen. In mammals and birds, further compactation of trabeculae leads to the formation of a compact layer. The potential mechanisms that may contribute to the formation of the ridges are under discussion and include myocardial proliferation, endocardial invagination, and bending of the entire myocardial layer. However, no description of the development of the mixed myocardium is available. To shed some light on this issue, we have studied the heart development of an elasmobranch species with mixed myocardium, the lesser spotted dogfish (Scyliorhinus canicula; Chondrichthyes), by means of histological and immunohistochemical techniques for light microscopy, semithin sections, scanning electron microscopy and transmission electron microscopy. Our results suggest that in the dogfish the intertrabecular spaces develop by connections between early intramyocardial spaces and the lumen of the ventricle through invaginations of the endocardial line. Chondrichthyans are the earliest diverged lineage of gnathostomes and, consequently, they have the most primitive cardiac design. Although chicken, mouse, and recently zebrafish have been considered powerful vertebrate models to study heart development, we propose that the trabeculation process in the dogfish is representative of the early steps of the ventricular morphogenesis in vertebrates.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.Study supported by grant CGL2017-85090-P and CGL2014-52356-P (Ministerio de Economía y Competitividad), FPU15/03209 (Ministerio de Educación, Cultura y Deporte), FEDER, and Universidad de Málaga

The anatomical components of the cardiac outflow tract of the bichir, polypterus senegalus. Evolutionary significance

El resumen aparece en el Program & Abstracts of the 10th International Congress of Vertebrate Morphology, Barcelona 2013.Anatomical Record, Volume 296, Special Feature — 1: P-077.In chondrichthyans and actinopterygians, the outflow tract of the heart, namely, the cardiac portion intercalated between the ventricle and the ventral aorta, consists of two anatomical components: conus arteriosus and bulbus arteriosus. In chondrichthyans and extant representatives of phylogenetically ancient actinopterygian groups, the conus and bulbus are well-developed in size, whereas in most teleosts, the bulbus is markedly larger than the conus. Current knowledge about the cardiac outflow tract of the polypteriformes is scarce and highly contradictory, a fact that contrasts with their crucial phylogenetic position at the source of the actinopterygian lineage. In fact, it remains uncertain whether they have a bulbus at the arterial pole of the heart. The present study aimed to elucidate the anatomical arrangement of the cardiac outflow tract of the bichir in an attempt to improve our understanding of the evolution of the vertebrate heart. We examined the hearts from 12 bichirs using histochemical and immunohistochemical techniques. Our findings showed that the outflow tract of the bichir consists of two components, namely, a long conus arteriosus, largely composed of myocardial tissue and furnished with a variable number of valves at its luminal side, and a very short, elastin rich bulbus arteriosus, devoid of myocardium. The bulbus has an arterial-like histological composition. However, it differs from the aorta because it has a thicker wall, shows a different arrangement of the histological elements, is covered by the epicardium and is crossed by coronary arteries. The present observations are consistent with the notion that the conus arteriosus and the bulbus arteriosus have coexisted from the beginning of the jawed vertebrate radiation. This is of particular interest, because there is evidence that the bulbus arteriosus, which is a second heart field derivative, is homologous with the intrapericardial portions of the aorta and pulmonary artery of birds and mammals.Proyecto CGL2010-16417/BOS; Fondos FEDER

Cartilage in pulmonary valves of Syrian Hamsters

En el campo "Centro"(centro de origen del ítem) he seleccionado la Facultad de Ciencias ya que este artículo se publicó durante mi adscripción al departamento de Biología Animal.El cartílago y/o el hueso se desarrollan en el esqueleto cardíaco de varias especies de mamíferos. Se observó depósitos cartilaginosos en la válvula aórtica, trígonos fibrosos y tabique interventricular. También se conoce la presencia de cartílago en la válvula pulmonar en aves, pero no en mamíferos. En este trabajo se describe la aparición de tejido cartilaginoso en las válvulas pulmonares de 40 de 351 hámsteres sirios examinados mediante técnicas histológicas, histoquímicas y/o inmunohistoquímicas. Los depósitos cartilaginosos se localizaron en las uniones fibrosas de las valvas de la válvula a la pared del tronco de la arteria pulmonar. Nuestros hallazgos indican que las uniones proximales de las valvas a sus respectivos senos, y especialmente la de la valva ventral, son las regiones valvulares más propensas a desarrollar focos cartilaginosos. No obstante, la posible función de estos focos sigue siendo una cuestión sin resolver. La formación de cartílago en la válvula pulmonar comienza durante el primer mes de vida, es decir en el período en el que la válvula alcanza la maduración histológica. La evidencia más temprana de condrogénesis es la presencia de pequeños grupos de células incrustadas en una matriz extracelular positiva para colágeno tipo II. Estos grupos celulares aumentan de tamaño y se diferencian en tejido cartilaginoso hialino. Se supone que los precursores de las células cartilaginosas son elementos derivados de la cresta neural. Sin embargo, se desconoce el factor o factores implicados en la diferenciación de estos precursores en condrocitos. Cabe destacar que, tanto en aves como en mamíferos, la formación de cartílago en las válvulas aórtica y pulmonar son eventos independientes. Esto encaja con la hipótesis de que la morfogénesis de las válvulas semilunares cardíacas puede estar mediada por subpoblaciones específicas de células de la cresta neural cardíaca, que actúan por separado en ambos lados del tracto de salida cardíaco embrionario.D.G.E.S. (Ministerio de Educaci6n y Cultura, España): PB98-1418-C02-0

Correlation between permanent tooth eruption pattern and the predominance of the motor function laterality

Objectives: To asses whether dental eruption order can play a role in the early diagnosis of crossed laterality. Study Design: Dental eruption pattern along with eye, ear, hand and foot lateralism were examined on 131 chil - dren between 6 to 8 years old from public schools from a multietnic population area of Barcelona city. Statistic methods (Statgraphics Plus 5.1 program) were used to evaluate data recollected. Results: Only foot and dentition lateralities behave as independent variables regarding hand laterality. So dental eruption laterality (along with the foot one) would be one of the parameters more related to hand laterality given that dentition variable relationship is greater that the foot one. This suggests that tooth eruption could be more clinically relevant. Crossed laterality hand-foot is significantly more predominant in men (13%) than in women (1,6%). Meanwhile, the relationship between hand and dentition didn't show any influence of sex. Conclusions: Dental eruption order, can be used as a good parameter in the determination of the patient's laterality

Construction and validation of a self-discrepancies scale of competence in nursing care

Objetivos: Diseñar y validar una escala para estudiantes de enfermería que identifica las concepciones en las competencias de cuidado y determina las discrepancias que puedan derivarse entre las experiencias actuales en la adquisición de competencias y los estándares o guías establecidos por la propia profesión. Métodos: Estudio transversal con una muestra de 349 estudiantes de primero y cuarto de Enfermería. Se elaboró una primera versión de la escala que fue depurada siguiendo criterios estadísticos y de jueces expertos. La escala definitiva contempla 24 ítems de competencias de cuidado. Resultados: Se aporta una escala con adecuadas propiedades psicométricas. Incluye dos subescalas con dos dominios independientes entre sí (Yo real, Yo debería). Discusión: Se plantea una línea de trabajo que introduce nuevos elementos para el análisis del bienestar y el éxito académico y profesional de los estudiantes de enfermería en función de la concepción real y normativa de las competencias de cuidado.Objectives: To design and to validate a scale for nursing students, that allows to identify the conceptions on nursing care competences and determine any possible discrepancies that may arise between their current experiences in the acquisition of competence and the standards or guidelines established by the own profession. Methods: Cross-sectional study with a sample of 349 first- and fourth-year students of Nursing. A first version of the scale according statistical criteria and expert judges was refined. The final 24-item scale provides nursing care competences. Results: It provides a scale with adequate psychometric properties. It includes two subscales with two domains independent from each other (actual self, ought self). Discussion: There is a line of work, which introduces a new way of analysis to determine the well-being and the academic and professional success of nursing students, based on their actual and normative conception of nursing care competences

Specific Relapse Predictors: Could Cognitive-Behavioral Treatment for Smoking Cessation Be Improved?

Relapse remains a frequent and complex phenomenon that is not yet well understood. An under-researched area of study that may provide relevant information concerns the assessment of specific post-treatment variables, rather than the composite measures commonly used to predict smoking relapse. The current study sought to examine the effects of post-treatment smoking-related variables, including withdrawal symptomatology, abstinence self-efficacy, and smoking urgency in negative-affect situations and smoking relapse at the 3 month follow-up. The sample comprised 130 participants who achieved abstinence for at least 24 h through a cognitive-behavioral smoking cessation treatment. Regression analysis was conducted for both composite measures and specific subscales and items. Data showed that composite measures of tobacco withdrawal, self-efficacy, and smoking urgency in negative-affect situations were not significant predictors of smoking relapse. However, the analysis including subscales, and specific items showed that lower self-efficacy in negative-affect-related situations (OR = 1.36) and three withdrawal symptoms—irritability/frustration/anger (OR = 2.99), restlessness/impatience (OR = 1.87), and craving (OR = 2.31)—were significant predictors of relapse. These findings offer new insights into the role of different smoking-related post-treatment variables in short-term relapse. Considering and specifically targeting these variables after achieving abstinence may potentially contribute to reducing smoking relapseThis research was supported by the Spanish Ministry of Economy and Competitiveness (Project reference: PSI2015–66755-R) and co-financed by FEDER (European Regional Development Fund; pluri-annual plan 2014–2020)S

Brooding rumination and anxiety sensitivity: associations with depressive and anxiety symptoms in treatment-seeking smokers

This study explores the shared and specific associations of brooding rumination and anxiety sensitivity to depression and anxiety symptomatology in a sample of treatment-seeking smokers. Methods: The sample was composed of 275 treatment-seeking adult smokers. Hierarchical linear regression analyses were conducted to examine the relations of both variables with depressive and anxiety symptoms. Results: Greater brooding rumination and anxiety sensitivity predicted higher levels of depression and anxiety symptoms. A specific relationship emerged after controlling for comorbid symptoms (depressive or anxiety symptoms) where brooding rumination was associated with depressive symptoms and anxiety sensitivity with anxiety symptoms. Conclusions: The findings showed that the variables examined are transdiagnostically related to emotional symptoms, but this relationship was symptomatology specific when controlling for comorbid symptoms (depressive or anxiety symptoms). Due to the impact of affective symptoms on abstinence outcomes, these findings have relevant clinical implications. In the context of smoking cessation treatment, identifying shared and specific vulnerabilities might contribute to tailoring and designing more precise and effective interventions for quitting smokingAntecedentes: este estudio explora las asociaciones compartidas y específicas entre el factor reproches de la rumiación y la sensibilidad a la ansiedad con la sintomatología depresiva y ansiosa en una muestra de fumadores. Método: la muestra estaba formada por 275 fumadores adultos que demandaron tratamiento para dejar de fumar. Se realizó un análisis de regresión lineal jerárquica para examinar las relaciones de ambas variables con los síntomas depresivos y ansiosos. Resultados: mayores puntuaciones en rumiación-reproches y en sensibilidad a la ansiedad predijeron niveles más elevados de síntomas depresivos y ansiosos. Sin embargo, cuando se controlaron los síntomas comórbidos (depresivos o ansiosos), emergieron relaciones específicas entre la rumiación-reproches y los síntomas depresivos y entre la sensibilidad a la ansiedad y los síntomas ansiosos. Conclusiones: las variables examinadas se relacionan transdiagnósticamente con la sintomatología emocional, pero esta relación pasa a ser específica cuando se controlan los síntomas comórbidos (depresivos o ansiosos). Debido al impacto negativo que tienen los síntomas emocionales en la abstinencia, estos resultados pueden aportar implicaciones clínicas relevantes. La identificación de vulnerabilidades compartidas y específicas podría contribuir a adaptar y diseñar intervenciones más precisas y eficaces para dejar de fumarThis research was supported by the Spanish Ministry of Economy and Competiveness (Project reference: PSI2015-66755-R) and co-fi nanced by FEDER (European Regional Development Fund; pluri-annual plan 2014-2020)S