4,846 research outputs found

    In vivo ratiometric optical mapping enables high-resolution cardiac electrophysiology in pig models

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    AIMS: Cardiac optical mapping is the gold standard for measuring complex electrophysiology in ex vivo heart preparations. However, new methods for optical mapping in vivo have been elusive. We aimed at developing and validating an experimental method for performing in vivo cardiac optical mapping in pig models. METHODS AND RESULTS: First, we characterized ex vivo the excitation-ratiometric properties during pacing and ventricular fibrillation (VF) of two near-infrared voltage-sensitive dyes (di-4-ANBDQBS/di-4-ANEQ(F)PTEA) optimized for imaging blood-perfused tissue (n = 7). Then, optical-fibre recordings in Langendorff-perfused hearts demonstrated that ratiometry permits the recording of optical action potentials (APs) with minimal motion artefacts during contraction (n = 7). Ratiometric optical mapping ex vivo also showed that optical AP duration (APD) and conduction velocity (CV) measurements can be accurately obtained to test drug effects. Secondly, we developed a percutaneous dye-loading protocol in vivo to perform high-resolution ratiometric optical mapping of VF dynamics (motion minimal) using a high-speed camera system positioned above the epicardial surface of the exposed heart (n = 11). During pacing (motion substantial) we recorded ratiometric optical signals and activation via a 2D fibre array in contact with the epicardial surface (n = 7). Optical APs in vivo under general anaesthesia showed significantly faster CV [120 (63-138) cm/s vs. 51 (41-64) cm/s; P = 0.032] and a statistical trend to longer APD90 [242 (217-254) ms vs. 192 (182-233) ms; P = 0.095] compared with ex vivo measurements in the contracting heart. The average rate of signal-to-noise ratio (SNR) decay of di-4-ANEQ(F)PTEA in vivo was 0.0671 ± 0.0090 min-1. However, reloading with di-4-ANEQ(F)PTEA fully recovered the initial SNR. Finally, toxicity studies (n = 12) showed that coronary dye injection did not generate systemic nor cardiac damage, although di-4-ANBDQBS injection induced transient hypotension, which was not observed with di-4-ANEQ(F)PTEA. CONCLUSIONS: In vivo optical mapping using voltage ratiometry of near-infrared dyes enables high-resolution cardiac electrophysiology in translational pig models.The CNIC is supported by the Ministry of Science, Innovation and Universities and the Pro CNIC Foundation. The CNIC is a Severo Ochoa Center of Excellence (SEV-2015-0505). This study was supported by grants from Fondo Europeo de Desarrollo Regional (CB16/11/00458), the Spanish Ministry of Science, Innovation and Universities (SAF2016-80324-R, PI16/02110, and DTS17/00136), and by the European Commission (ERA-CVD Joint Call [JTC2016/APCIN-ISCIII-2016], grant#AC16/00021). The study was also partially supported by the Fundacio´n Interhospitalaria para la Investigacio´n Cardiovascular (FIC) and the Heart Rhythm section of the Spanish Society of Cardiology. The work at the University of Connecticut was supported by grant EB001963 from the National Institutes of Health.S

    Single instrument for hemostatic control in laparoscopic partial nephrectomy in a porcine model without renal vascular clamping

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    This is a copy of an article published in the Journal of Endourology Š2011 copyright Mary Ann Liebert, Inc.; Journal of Endourology is available online at: http://www.liebertpub.com/end[EN] Materials and Methods: We performed a comparative experimental study between a new radiofrequency (RF)-assisted device consisting of a handheld instrument that simultaneously conducts coagulation and cutting tasks without hilar clamping vs a standard technique with hilar clamping. A porcine model was used (10 animals per group) with survival of 17 days. Results: The estimated blood loss with the new device was significantly lower than with the standard technique (15.5 +/- 23.7 vs 79.4 +/- 76.3 mL). Although transection time was longer with the new device (10.7 +/- 13.7 vs 2.1 +/- 1.2 min), the total operative time was significantly shorter (35.3 +/- 13.7 vs 60.2 +/- 10.5 min). Evidence of localized urinary extravasation (urinoma) was identical in both groups (five cases). The group subjected to the new device, however, showed a significantly higher number of cases of leakage after conducting the methylene-blue test: eight (80%) cases vs only one (11%) with the standard technique. Necrosis depth was significantly greater with the new device (6.6 +/- 0.9 vs <1 mm). Conclusions: The experimental results suggest that the proposed RF-assisted device provides adequate hemostatic control during transection of the renal parenchyma without additional instruments or surgical maneuvers and could therefore be a valuable adjunct for LPN without vascular clamping. The device was unsuccessful in effectively sealing the collecting system.This work received financial support from the Spanish "Plan Nacional de I + D + I del Ministerio de Ciencia e Innovacion," Grant No. TEC2008-01369/TEC. The translation of this paper was funded by the Universidad Politecnica de Valencia, Valencia, Spain.Subira Rios, J.; Sanchez Zalabardo, JM.; Burdio, F.; Berjano, E.; Moros, M.; Gonzalez, A.; Navarro, A.... (2011). Single instrument for hemostatic control in laparoscopic partial nephrectomy in a porcine model without renal vascular clamping. Journal of Endourology and Part B, Videourology. 25(6):1005-1011. https://doi.org/10.1089/end.2010.0557S1005101125

    Stellar Population gradients in galaxy discs from the CALIFA survey

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    While studies of gas-phase metallicity gradients in disc galaxies are common, very little has been done in the acquisition of stellar abundance gradients in the same regions. We present here a comparative study of the stellar metallicity and age distributions in a sample of 62 nearly face-on, spiral galaxies with and without bars, using data from the CALIFA survey. We measure the slopes of the gradients and study their relation with other properties of the galaxies. We find that the mean stellar age and metallicity gradients in the disc are shallow and negative. Furthermore, when normalized to the effective radius of the disc, the slope of the stellar population gradients does not correlate with the mass or with the morphological type of the galaxies. Contrary to this, the values of both age and metallicity at ∟\sim2.5 scale-lengths correlate with the central velocity dispersion in a similar manner to the central values of the bulges, although bulges show, on average, older ages and higher metallicities than the discs. One of the goals of the present paper is to test the theoretical prediction that non-linear coupling between the bar and the spiral arms is an efficient mechanism for producing radial migrations across significant distances within discs. The process of radial migration should flatten the stellar metallicity gradient with time and, therefore, we would expect flatter stellar metallicity gradients in barred galaxies. However, we do not find any difference in the metallicity or age gradients in galaxies with without bars. We discuss possible scenarios that can lead to this absence of difference.Comment: 24 pages, 17 figures, accepted for publication in A&

    Human adaptations to multiday saturation on NASA NEEMO

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    Human adaptation to extreme environments has been explored for over a century to understand human psychology, integrated physiology, comparative pathologies, and exploratory potential. It has been demonstrated that these environments can provide multiple external stimuli and stressors, which are sufficient to disrupt internal homeostasis and induce adaptation processes. Multiday hyperbaric and/or saturated (HBS) environments represent the most understudied of environmental extremes due to inherent experimental, analytical, technical, temporal, and safety limitations. National Aeronautic Space Agency (NASA) Extreme Environment Mission Operation (NEEMO) is a space-flight analog mission conducted within Florida International University's Aquarius Undersea Research Laboratory (AURL), the only existing operational and habitable undersea saturated environment. To investigate human objective and subjective adaptations to multiday HBS, we evaluated aquanauts living at saturation for 9-10 days via NASA NEEMO 22 and 23, across psychologic, cardiac, respiratory, autonomic, thermic, hemodynamic, sleep, and body composition parameters. We found that aquanauts exposed to saturation over 9-10 days experienced intrapersonal physical and mental burden, sustained good mood and work satisfaction, decreased heart and respiratory rates, increased parasympathetic and reduced sympathetic modulation, lower cerebral blood flow velocity, intact cerebral autoregulation and maintenance of baroreflex functionality, as well as losses in systemic bodyweight and adipose tissue. Together, these findings illustrate novel insights into human adaptation across multiple body systems in response to multiday hyperbaric saturation

    An SiO Toroid and Wide-angle Outflow associated with the Massive Protostar W75N(B)-VLA2

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    We have carried out ALMA observations of the massive star-forming region W75N(B), which contains the massive protostars VLA1, VLA2, and VLA3. Particularly, VLA2 is an enigmatic protostar associated with a wind-driven H2_2O maser shell, which has evolved from an almost isotropic outflow to a collimated one in just 20 years. The shell expansion seemed to be halted by an obstacle located to the northeast of VLA2. Here we present our findings from observing the 1.3 mm continuum and H2_2CO and SiO emission lines. Within a region of ∼30"\sim 30" (∼39,000\sim 39,000 au) diameter, we have detected 40 compact mm-continuum sources, three of them coinciding with VLA1, VLA2, and VLA3. While the H2_2CO emission is mainly distributed in a fragmented structure around the three massive protostars, but without any of the main H2_2CO clumps spatially coinciding with them, the SiO is highly concentrated on VLA2, indicating the presence of very strong shocks generated near this protostar. The SiO emission is clearly resolved into an elongated structure (∼0.6"×0.3"\sim 0.6"\times0.3"; ∼780\sim 780 au×\times390 au) perpendicular to the major axis of the wind-driven maser shell. The structure and kinematics of the SiO emission are consistent with a toroid and a wide-angle outflow surrounding a central mass of ∼10\sim 10 M⊙_{\odot}, thus supporting previous theoretical predictions regarding the evolution of the outflow. Additionally, we have identified the expected location and estimated the gas density of the obstacle that is hindering the expansion of the maser shell.Comment: To be published in The Astrophysical Journal Letters. Sixteen pages, seven figures. Updated metadat

    Glioblastoma on a microfluidic chip: Generating pseudopalisades and enhancing aggressiveness through blood vessel obstruction events

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    Background: Glioblastoma (GBM) is one of the most lethal tumor types. Hypercellular regions, named pseudo- palisades, are characteristic in these tumors and have been hypothesized to be waves of migrating glioblastoma cells.These “waves” of cells are thought to be induced by oxygen and nutrient depletion caused by tumor-induced blood vessel occlusion. Although the universal presence of these structures in GBM tumors suggests that they may play an instrumental role in GBM’s spread and invasion, the recreation of these structures in vitro has remained challenging. Methods: Here we present a new microfluidic model of GBM that mimics the dynamics of pseudopalisade forma- tion.To do this, we embedded U-251 MG cells within a collagen hydrogel in a custom-designed microfluidic device. By controlling the medium flow through lateral microchannels, we can mimic and control blood-vessel obstruction events associated with this disease. Results: Through the use of this new system, we show that nutrient and oxygen starvation triggers a strong migratory process leading to pseudopalisade generation in vitro.These results validate the hypothesis of pseudo- palisade formation and show an excellent agreement with a systems-biology model based on a hypoxia-driven phenomenon. Conclusions: This paper shows the potential of microfluidic devices as advanced artificial systems capable of mod- eling in vivo nutrient and oxygen gradients during tumor evolution

    Targeted Next-Generation Sequencing in a Large Cohort of Genetically Undiagnosed Patients with Neuromuscular Disorders in Spain

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    This article belongs to the Special Issue Genetic Advances in Neuromuscular Disorders: From Gene Identification to Gene Therapy.The term neuromuscular disorder (NMD) includes many genetic and acquired diseases and differential diagnosis can be challenging. Next-generation sequencing (NGS) is especially useful in this setting given the large number of possible candidate genes, the clinical, pathological, and genetic heterogeneity, the absence of an established genotype-phenotype correlation, and the exceptionally large size of some causative genes such as TTN, NEB and RYR1. We evaluated the diagnostic value of a custom targeted next-generation sequencing gene panel to study the mutational spectrum of a subset of NMD patients in Spain. In an NMD cohort of 207 patients with congenital myopathies, distal myopathies, congenital and adult-onset muscular dystrophies, and congenital myasthenic syndromes, we detected causative mutations in 102 patients (49.3%), involving 42 NMD-related genes. The most common causative genes, TTN and RYR1, accounted for almost 30% of cases. Thirty-two of the 207 patients (15.4%) carried variants of uncertain significance or had an unidentified second mutation to explain the genetic cause of the disease. In the remaining 73 patients (35.3%), no candidate variant was identified. In combination with patients’ clinical and myopathological data, the custom gene panel designed in our lab proved to be a powerful tool to diagnose patients with myopathies, muscular dystrophies and congenital myasthenic syndromes. Targeted NGS approaches enable a rapid and cost-effective analysis of NMD- related genes, offering reliable results in a short time and relegating invasive techniques to a second tier.This study was granted by FIS PI15/01898, funded by ISCIII and FEDER, ‘Una manera de hacer Europa’ and by Fundación Mutua Madrileña in the “Convocatoria de ayudas a la Investigación en Salud 2015”. It was also funded by an ACCI grant from CIBERER. Daniel Natera-de Benito is the recipient of a grant from the Instituto de Salud Carlos III (Contrato Rio Hortega, CM17/00044)

    Molecular characterization of multidrug resistant Enterobacterales strains isolated from liver and kidney transplant recipients in Spain

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    The objective of this study was to analyse the mechanisms of resistance to carbapenems and other extended-spectrum-?-lactams and to determine the genetic relatedness of multidrug-resistant Enterobacterales (MDR-E) causing colonization or infection in solid-organ transplantation (SOT) recipients. Prospective cohort study in kidney (n= 142), liver (n= 98) or kidney/pancreas (n= 7) transplant recipients between 2014 and 2018 in seven Spanish hospitals. We included 531 MDR-E isolates from rectal swabs obtained before transplantation and weekly for 4?6 weeks after the procedure and 10 MDR-E from clinical samples related to an infection. Overall, 46.2% Escherichia coli, 35.3% Klebsiella pneumoniae, 6.5% Enterobacter cloacae, 6.3% Citrobacter freundii and 5.7% other species were isolated. The number of patients with MDR-E colonization post-transplantation (176; 71.3%) was 2.5-fold the number of patients colonized pre-transplantation (71; 28.7%). Extended spectrum ?-lactamases (ESBLs) and carbapenemases were detected in 78.0% and 21.1% of MDR-E isolates respectively. In nine of the 247 (3.6%) transplant patients, the microorganism causing an infection was the same strain previously cultured from surveillance rectal swabs. In our study we have observed a low rate of MDR-E infection in colonized patients 4?6 weeks post-transplantation. E. coli producing blaCTX-M-G1 and K. pneumoniae harbouring blaOXA-48 alone or with blaCTX-M-G1 were the most prevalent MDR-E colonization strains in SOT recipients.Acknowledgements The authors thank Mª Jesús Lecea and Laura Álvarez for technical assistance. Tis research was supported by ‘Plan Nacional de I+D+i and Instituto de Salud Carlos III (Fondo de Investigaciones Sanitarias 13/01191), Subdirección General de Redes y Centros de Investigación Cooperativa, Ministerio de Ciencia, Innovación y Universidades, and the Spanish Network for Research in Infectious Diseases (REIPI RD16/0016/0007, RD16/0016/0010, RD16/0016/0012, RD16/0016/0011, RD16/0016/0008, RD16/0016/0002). Te study was co-fnanced by the European Development Regional Fund “A way to achieve Europe” and the Operative Program Intelligent Growth 2014‐2020

    A longitudinal assessment of alcohol intake and incident depression: the sun project

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    Background: Longitudinal studies assessing the long-term association between alcohol intake and depression are scarce. The type of beverage may also be important. Therefore we aimed to prospectively evaluate the influence of alcohol intake on incident depression in a Mediterranean cohort. Methods: We assessed 13,619 university graduates (mean age: 38 years, 42% men) participating in a Spanish prospective epidemiological cohort (the SUN Project), initially free of depression. They were recruited between 1999–2008 and biennially followed-up during 2001–2010. At baseline, a 136-item validated food–frequency questionnaire was used to assess alcohol intake. Wine was the preferred beverage. Participants were classified as incident cases of depression if they reported a new clinical diagnosis of depression by a physician and/or initiated the use of antidepressant drugs. Cox regression and restricted cubic splines analyses were performed over 82,926 person-years. Results: Only among women, an U-shaped relationship between total alcohol intake and depression risk was found (P=0.01). Moderate alcohol intake (5–15 g/day) was associated with lower risk (Hazard Ratio: 0.62; 95% Confidence Interval: 0.43-0.89). No association was apparent for higher intakes of alcohol or for any specific type of alcoholic beverage. Conclusions: Moderate alcohol intake might protect against depression among women. Further confirmatory studies are needed

    Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

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    A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE
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