Stable Laboratory Culture System for the Ctenophore Mnemiopsis leidyi.

Ctenophores are marine organisms attracting significant attention from evolutionary biology, molecular biology, and ecological research. Here, we describe an easy and affordable setup to maintain a stable culture of the ctenophore Mnemiopsis leidyi. The challenging delicacy of the lobate ctenophores can be met by monitoring the water quality, providing the right nutrition, and adapting the handling and tank set-up to their fragile gelatinous body plan. Following this protocol allows stable laboratory lines, a continuous supply of embryos for molecular biological studies, and independence from population responses to environmental fluctuations.

Odd family reunion: DNA barcoding reveals unexpected relationship between three hydrozoan species.

Knowledge of life histories is crucial for understanding ecological and evolutionary processes, but for many hydrozoan species only incomplete life cycles have been described due to challenges in linking hydromedusae with their polyp stages. Using a combination of DNA barcoding, morphology, and ecological information, we describe for the first time the polyp stage of Halopsis ocellata Agassiz, 1865 and re-describe that of Mitrocomella polydiademata (Romanes, 1876). Campanulinid hydroids referable to Lafoeina tenuis Sars, 1874 and collected in the same biogeographic region as the type locality of this species are shown to be the polyp stage of these two mitrocomid hydromedusae. The nominal species L. tenuis thus is a species complex that includes the polyp stage of medusae belonging to at least two genera currently placed in a different family. Consistent morphological and ecological differences were found between the polyps linked to each of these two hydromedusae, but molecular results suggest that yet other species may have morphologically similar hydroids. Polyps morphologically identified to L. tenuis are therefore better referred to as Lafoeina tenuis-type until further associations are resolved, particularly when occurring outside of the area of distribution of H. ocellata and M. polydiademata. Molecular identification integrated with traditional taxonomy is confirmed as an effective approach to link inconspicuous stages of marine invertebrates with hitherto unknown life cycles, especially in often-overlooked taxa. Disentangling the relationships between L. tenuis, H. ocellata, and M. polydiademata lays the ground for future research aimed at resolving the taxonomy and systematics of the enigmatic families Mitrocomidae and Campanulinidae.

Syncytial nerve net in a ctenophore adds insights on the evolution of nervous systems.

A fundamental breakthrough in neurobiology has been the formulation of the neuron doctrine by Santiago Ramón y Cajal, which stated that the nervous system is composed of discrete cells. Electron microscopy later confirmed the doctrine and allowed the identification of synaptic connections. In this work, we used volume electron microscopy and three-dimensional reconstructions to characterize the nerve net of a ctenophore, a marine invertebrate that belongs to one of the earliest-branching animal lineages. We found that neurons in the subepithelial nerve net have a continuous plasma membrane that forms a syncytium. Our findings suggest fundamental differences of nerve net architectures between ctenophores and cnidarians or bilaterians and offer an alternative perspective on neural network organization and neurotransmission.

Neuropeptide repertoire and 3D anatomy of the ctenophore nervous system.

Ctenophores are gelatinous marine animals famous for locomotion by ciliary combs. Due to the uncertainties of the phylogenetic placement of ctenophores and the absence of some key bilaterian neuronal genes, it has been hypothesized that their neurons evolved independently. Additionally, recent whole-body, single-cell RNA sequencing (scRNA-seq) analysis failed to identify ctenophore neurons using any of the known neuronal molecular markers. To reveal the molecular machinery of ctenophore neurons, we have characterized the neuropeptide repertoire of the ctenophore Mnemiopsis leidyi. Using the machine learning NeuroPID tool, we predicted 129 new putative neuropeptide precursors. Sixteen of them were localized to the subepithelial nerve net (SNN), sensory aboral organ (AO), and epithelial sensory cells (ESCs), providing evidence that they are neuropeptide precursors. Four of these putative neuropeptides had a behavioral effect and increased the animals' swimming speed. Intriguingly, these putative neuropeptides finally allowed us to identify neuronal cell types in single-cell transcriptomic data and reveal the molecular identity of ctenophore neurons. High-resolution electron microscopy and 3D reconstructions of the nerve net underlying the comb plates confirmed a more than 100-year-old hypothesis of anastomoses between neurites of the same cell in ctenophores and revealed that they occur through a continuous membrane. Our work demonstrates the unique ultrastructure of the peptidergic nerve net and a rich neuropeptide repertoire of ctenophores, supporting the hypothesis that the first nervous system(s) evolved as nets of peptidergic cells.

Benthic hydroids (Cnidaria, Hydrozoa) from the Weddell Sea (Antarctica).

Hydrozoans are a conspicuous component of Antarctic benthic communitites. Recent taxonomic effort has led to a substantial increase in knowledge on the diversity of benthic hydroids from some areas of the Southern Ocean, including the Weddell Sea, the largest sea in the Antarctic region. However, the study of many hydrozoan taxa are still pending, and the diversity in this huge region is expected to be higher than currently known. In order to contribute to the knowledge of taxonomy, ecology and distribution of these cnidarians, a study of unpublished material collected by several German Antarctic expeditions aboard the RV Polarstern in the eastern sector of the Weddell Sea has been conducted. A total of 77 species belonging to 22 families and 28 genera of benthic hydroids have been inventoried, constituting the most prolific collection hitherto analyzed. Most species (81%) belong to Leptothecata, but the observed share of Anthoathecata (19%) is higher than in previous Antarctic hydrozoan studies. Symplectoscyphidae was the most speciose family with 16 representatives (22%), followed by Haleciidae with 10 (14%) and Staurothecidae with 8 (11%). The number of species known in the area was increased with 27 new records, including several species rarely documented. As a result, the Weddell Sea becomes the second Antarctic region in terms of hydrozoan diversity, with 89 species known to date. Novel data on the use of substrate, reproductive phenology, and bathymetric range are provided for the inventoried species.

Clinical and procedural evaluation of the Nile Croco® dedicated stent for bifurcations: a single centre experience with the first 151 consecutive non-selected patients.

AIMS: To evaluate the feasibility and safety of the Nile Croco® coronary bifurcation stent system (Minvasys, Gennevilliers, France). METHODS AND RESULTS: The primary endpoint was to assess the acute device success and angiographic success with the use of the Nile Croco® stent system. Secondary endpoints included in-hospital and six month major cardiac events (MACE).There were 151 consecutive patients enrolled in the Nile Croco Study at Vall Hebrón Hospital. The Nile Croco® stent was successfully implanted in 144 patients (95.4%) and final angiographic success was obtained in 100% of the patients. 138 out of the 151 (91%) patients included have accomplished the six month follow-up. There was one in-hospital MACE in the 151 recruited patients. The MACE rate at six months in the 138 patients with follow-up was 14% and the ischaemia-driven TLR rate was 7.2 %. CONCLUSIONS: The results of our Nile Croco® Study are the first to demonstrate the safety and high performance of this dedicated stent system for the treatment of bifurcation lesions. The device can be successfully implanted in more than 95% of all cases, with a high procedural success rate and low in-hospital and six month MACE rates.

MRI discriminates thrombus composition and ST resolution after percutaneous coronary intervention in patients with ST-elevation myocardial infarction.

Histological composition of material obtained by thrombus aspiration during percutaneous coronary intervention (PCI) in patients with ST-segment elevation acute myocardial infarction (STEMI) is highly variable. We aimed to characterize this material using magnetic resonance imaging (MRI) and to correlate MRI findings with the success of PCI in terms of ST-segment resolution. Thrombus aspiration during primary or rescue PCI was attempted in 100 consecutive STEMI patients, of whom enough material for MRI was obtained in 59. MR images were obtained at 9.4T and T1 and T2 values were measured. Patients with (n = 31) and without (n = 28) adequate ST resolution 120 min after PCI (≥70% of pre-PCI value) had similar baseline characteristics except for a higher prevalence of diabetes mellitus in the latter (10 vs. 43%, p = 0.003). T1 values were similar in both groups (1248±112 vs. 1307±85 ms, respectively, p = 0.7). T2 values averaged 31.2±10.3 and 36.6±12.2 ms; in thrombus from patients with and without adequate ST resolution (p = 0.09). After adjusting for diabetes and other baseline characteristics, lower T2 values were significantly associated with inadequate ST resolution (odds ratio for 1 ms increase 1.08, CI 95% 1.01-1.16, p = 0.027). Histology classified thrombus in 3 groups: coagulated blood (n = 38), fibrin rich (n = 9) and lipid-rich (n = 3). Thrombi composed mostly of coagulated blood were characterized as being of short (n = 10), intermediate (n = 15) or long evolution (n = 13), T2 values being 34.0±13.2, 31.9±8.3 and 31.5±7.9 ms respectively (p = NS). In this subgroup, T2 was significantly higher in specimens from patients with inadequate perfusion (35.9±10.3 versus 28.6±6.7 ms, p = 0.02). This can be of clinical interest as it provides information on the probability of adequate ST resolution, a surrogate for effective myocardial reperfusion.

Extent of myocardial ischemia during coronary occlusion in single vessel disease. A comparison between patients with exercise-induced angina and patients with recurrent angina at rest.

Patients with exercise angina >2 months (n:13) showed significantly lower SigmaST elevation during 120 s balloon coronary occlusion than those with =<2 months (n:7), or those with angina at rest <=2 days (n:8) but similar to patients with angina at rest >2 days (n:7). These results underscore the importance of the kind and duration of angina in limiting the extent of ischemia during coronary occlusion.

Revascularización coronaria en el paciente diabético / Coronary revascularization in diabetic patients

La enfermedad cardiovascular es la principal causa de morbilidad y mortalidad en los pacientes con diabetes mellitus. Se ha demostrado que los pacientes diabéticos presentan una mayor incidencia de enfermedad coronaria multivaso, con mayor frecuencia de lesiones complejas, pobres lechos distales y una progresión de la enfermedad más rápida que la población general no diabética. La revascularización coronaria percutánea (ICP) ha demostrado su utilidad en los pacientes diabéticos. Sin embargo, aunque los resultados angiográficos iniciales son buenos, hay una mayor incidencia de reestenosis, un riesgo más elevado de complicaciones y una menor supervivencia a largo plazo. Los stents farmacoactivos han reducido notablemente el riesgo de reestenosis y complicaciones tardías. En espera de los resultados de los estudios actualmente en marcha, en los pacientes diabéticos con enfermedad multivaso, la cirugía de derivación aortocoronaria sigue siendo el tratamiento de primera elección. Sin embargo, hay que destacar que, desde un punto de vista práctico, a la hora de indicar cirugía de derivación aortocoronaria o ICP deberemos basarnos en las características particulares del paciente (p. ej., comorbilidad asociada) y en la experiencia del propio centro, ya que hay notables diferencias en función de la experiencia del equipo quirúrgico y de cardiología intervencionista. Por último, es muy importante destacar que, en los pacientes diabéticos en los que se realiza revascularización coronaria, con independencia del método utilizado, es de trascendental importancia establecer un tratamiento médico enérgico que incluya modificaciones en el estilo de vida (tabaquismo, síndrome metabólico, etc.), antiagregación plaquetaria, tratamiento con estatinas en las dosis adecuadas (objetivo terapéutico con un valor de colesterol unido a lipoproteínas de baja densidad < 70 mg/dl), bloqueadores beta, inhibidores de la enzima de conversión de la angiotensina-inhibidores de los receptores de la angiotensina II, control glicérico-metabólico, etc., ya que en estos pacientes la progresión de la enfermedad es mucho más rápida que en la población no diabética y el riesgo de complicaciones, a pesar de la revascularización, sigue siendo elevado (AU)

Cardiovascular disease is the principle cause of morbidity and mortality in patients with diabetes mellitus. It has been observed that diabetic patients usually present with a higher incidence of coronary artery disease involving multiple vessels, complex lesions, poor distal vascular beds, and more rapid disease progression than does the general nondiabetic population. Percutaneous coronary revascularization has been shown to be useful in diabetic patients. However, although initial angiographic results are good, there is a high incidence of restenosis, a increased risk of complications, and a low long-term survival rate. Drugeluting stent have markedly reduced the risk of restenosis and late complications. While the results of ongoing studies are still awaited, bypass surgery remains the treatment of first choice in diabetic patients with multivessel disease. Nevertheless, it is important to remember that, from a practical point of view, the decision on when to carry out bypass surgery or percutaneous coronary intervention must be based on the individual patient’s characteristics (e.g., associated comorbid conditions) and on the experience of the center involved. The level of experience of surgical teams and interventional cardiologists varies widely. Finally, it should be emphasized that the administration of aggressive medical treatment is of paramount importance in diabetic patients who are undergoing coronary revascularization, irrespective of the technique used. Treatment should include lifestyle modification (e.g., for smoking and metabolic syndrome), and, for example, antiplatelet therapy, an adequate statin dose (with the aim of achieving a low-density lipoprotein cholesterol level < 70 mg/dL), beta-blockers, angiotensinconverting enzyme inhibitors, and angiotensin II receptor antagonists because disease progression is much more rapid in these patients than in the nondiabetic population and the risk of complications remains elevated, despite revascularization (AU)

Three-dimensional fusion of coronary arteries with myocardial perfusion distributions: clinical validation.

UNLABELLED: Clinical decisions regarding diagnosis and effective treatment of coronary artery disease frequently require integration of information from various imaging modalities, which are acquired, processed, and read at different physical locations and times. We have developed methods to integrate the information in 2 cardiac imaging studies, perfusion SPECT and coronary angiography. Three-dimensional (3D) models of the coronary artery tree created from biplane angiograms were automatically aligned with 3D models of the left ventricular epicardial surface created from perfusion SPECT. Myocardial mass at risk was used as a unique measure to validate the accuracy of the unification. METHODS: Thirty patients were injected with the perfusion agent (99m)Tc-tetrosfosmin during balloon occlusion while undergoing percutaneous transluminal coronary angioplasty for single-vessel coronary artery disease. Thus, a single, severe perfusion defect was induced by a single coronary artery occlusion of known severity and placement. The accuracy of the unification was measured by computing the overlap between physiologic area at risk, determined using SPECT perfusion quantification techniques only, and anatomic area at risk, determined using coronary artery anatomy aligned with the epicardial surface of the left ventricle. RESULTS: The unification resulted in an 80% overlap of areas at risk, and an overlap of 84% of normal areas, for all coronary artery distributions. The mass at risk measured based on the unified anatomic information correlated with the physiologically based mass at risk as y = 0.92x + 10.3 g; r = 0.76, SEE = 10.4 g. CONCLUSION: A unification algorithm for automatically registering 3D models of the epicardial surface from perfusion SPECT and 3D coronary artery trees from coronary angiography has been presented and validated in 30 patient studies.

[Unified three-dimensional images of myocardial perfusion and coronary angiography]. / Superposición en tres dimensiones de las imágenes de perfusión miocárdica y de la coronariografía.

INTRODUCTION AND OBJECTIVES: In everyday clinical practice, the cardiologist needs to integrate anatomical and functional information from patients with coronary artery disease. The aim of this study is to present a way to unify, in three-dimensional images, anatomical information from coronary angiography with physiological information from myocardial perfusion scintigraphy. METHODS: Three patients with one vessel disease (left anterior descending, right coronary and left circumflex arteries, respectively) scheduled for percutaneous coronary revascularization were selected. Two-dimensional angiographic images were obtained before and after revascularization. 99mTc-tetrofosmin was administered during coronary occlusion and tomographic images corresponding to the occlusion were detected after coronary dilatation. Control rest scintigraphic images were obtained after two days. The three-dimensional coronary tree from coronary angiography was superposed on the epicardial contours of the myocardial perfusion images following a method of our own. RESULTS: A correct three-dimensional reconstruction of myocardial contour and coronary tree was achieved for each patient. The three-dimensional unified images showed excellent concordance between the extent of perfusion defects and the anatomic distribution of the occluded vessel. CONCLUSIONS: Three-dimensional unification of myocardial perfusion images and coronary angiography is technically possible. This technology integrates anatomical and functional information to facilitate the cardiologist's decision-making and so improve coronary patient management.

Superposición en tres dimensiones de las imágenes de perfusión miocárdica y de la coronariografía / Unified three-dimensional images of myocardial perfusion and coronary angiography

Introducción y objetivos. Integrar la información anatómica y funcional en pacientes con cardiopatía isquémica es una tarea habitual en la práctica diaria del cardiólogo. El objetivo de este trabajo es presentar una metodología de unificación tridimensional de la información anatómica relativa a las coronarias epicárdicas, proveniente de la coronariografía, con la información fisiológica de perfusión tisular procedente de la tomogammagrafía de perfusión miocárdica. Métodos. Se seleccionaron 3 pacientes programados, por criterios clínicos, para revascularización coronaria percutánea y con enfermedad de un solo vaso (descendente anterior, coronaria derecha y circunfleja). Las imágenes coronariográficas biplanares se obtuvieron antes y después de la dilatación. Durante la oclusión coronaria se administró una dosis de 99mTc-tetrofosmina y, una vez finalizada la dilatación, se obtuvieron las imágenes de perfusión miocárdica correspondientes a la oclusión. La tomogammagrafía de control en reposo se repitió dos días después. Mediante una metodología propia se generaron los contornos epicárdicos de las imágenes de perfusión miocárdica y sobre ellos se superpuso el árbol coronario tridimensional proveniente de la coronariografía. Resultados. Se logró una correcta reconstrucción tridimensional del contorno epicárdico y del árbol coronario completo en los 3 pacientes. La imagen unificada en tres dimensiones presentó una excelente concordancia entre la extensión de los defectos de perfusión y la distribución anatómica del vaso ocluido. Conclusiones. La superposición tridimensional de las imágenes de perfusión miocárdica y de la coronariografía es técnicamente posible. Ello permite integrar la información anatómica y funcional de cara a facilitar la toma de decisiones por parte del cardiólogo y mejorar el manejo del paciente coronario (AU)