Photogenerated Radical in Phenylglyoxylic Acid for in Vivo Hyperpolarized 13C MR with Photosensitive Metabolic Substrates

Whether for 13C magnetic resonance studies in chemistry, biochemistry or biomedicine, hyperpolarization methods based on dynamic nuclear polarization (DNP) have become ubiquitous. DNP requires a source of unpaired electrons, which are commonly added to the sample to be hyperpolarized in the form of stable free radicals. Once polarized, the presence of these radicals is unwanted. These radicals can be replaced by nonpersistent radicals created by photo-irradiation of pyruvic acid (PA), which are annihilated upon dissolution or thermalization in the solid state. However, since PA is readily metabolized by most cells, its presence may be undesirable for some metabolic studies. In addition, some 13C substrates are photo-sensitive and, therefore, may degrade during photo-generation of PA radical, which requires ultraviolet (UV) light. We show here that photoirradiation of phenylglyoxylic acid (PhGA) using visible light produces a non-persistent radical that, in principle, can be used to hyperpolarize any molecule. We compare radical yields in samples containing PA and PhGA upon photo-irradiation with broadband and narrowband UV-visible light sources. To demonstrate the suitability of PhGA as a radical precursor for DNP, we polarized the gluconeogenic probe 13C-dihydroxyacetone, which is UV-sensitive, using a commercial 3.35 T DNP polarizer and then injected this into a mouse and followed its metabolism in vivo.This work is part of a project that has received funding from the European Union’s Horizon 2020 European Research Council (ERC Consolidator Grant) under grant agreement no. 682574 (ASSIMILES). Funding was also received from a Cancer Research UK Programme grant (17242) and from the CRUK-EPSRC Imaging Centre in Cambridge and Manchester (16465). F.K. and S.P. received funding from the European Union’s Horizon 2020 Research and Innovation Program under Marie Sklodowska-Curie grant agreement no. 642773 (EUROPOL). A. Capozzi received funding from the European Union’s Horizon 2020 Research and Innovation Program under Marie Sklodowska-Curie grant agreement no. 713683 (COFUNDfellowsDTU)

O HIPOTÁLAMO DORSOMEDIAL E A ORGANIZAÇÃO DA RESPOSTA CARDIOVASCULAR AO ESTRESSE EMOCIONAL: UMA PERSPECTIVA FUNCIONAL

Emotional stress results in activation of specific pathways into central nervous system, which produces autonomic, behavioral and endocrine responses. It is known that repetitive or continuous exposition to stress situations may result in various pathologic states, for example, arterial hypertension. Classically, the hypothalamus plays an essential role in the integration of physiological responses to emotional stress. Recent studies demonstrate that a specific nucleus from hypothalamus, the dorsomedial hypothalamus (DMH), is an essential component of central pathways that mediate the cardiovascular response to emotional stress. Inhibition of neurons in this area reduces the increases in heart rate and blood pressure in rats submitted to emotional stress paradigms. Conversely, pharmacological activation of DMH neurons evokes increases on heart rate, blood pressure, adrenocorticotrophic hormone, locomotor activity and sympathetic activity. The similarity of this response with that produced during emotional stress suggests that this area is crucial in the integration of the physiological responses to emotional stress. The present review will discuss the central pathways used by DMH in the organization of the cardiovascular response to emotional stress.O estresse emocional resulta em ativação de vias específicas do sistema nervoso central, que produzem respostas autonômicas, comportamentais e endócrinas. Sabe-se que situações de estresse recorrentes ou prolongadas podem resultar em vários estados patológicos, como por exemplo, a hipertensão arterial. O Hipotálamo tem papel fundamental na integração das respostas fisiológicas ao estresse emocional. Particularmente, estudos têm mostrado que um núcleo específico do hipotálamo, o hipotálamo dorsomedial (DMH), é um componente fundamental das vias centrais mediadoras das respostas cardiovasculares ao estresse emocional. A inibição dos neurônios dessa área reduz os aumentos de freqüência cardíaca e de pressão arterial em ratos quando submetidos à situações de estresse emocional. Ao contrário, a ativação farmacológica dos neurônios do DMH produz aumento na frequência cardíaca, pressão arterial, hormônio adrenocorticotrópico (ACTH), atividade locomotora e na atividade simpática para diversos leitos vasculares. A similaridade dessa resposta com aquela produzida durante a situação real de estresse emocional sugere que esta área é fundamental na integração da resposta fisiológica ao estresse. A presente revisão tem como objetivo mostrar, através de resultados de estudos recentes, as vias centrais utilizadas pelo DMH na organização da resposta cardiovascular ao estresse emocional

Inflamación crónica granulomatosa en el pez teleósteo Piaractus mesopotamicus: modelo de estudio histopatológico

Objective. This study evaluated the cell kinetic and formation of granuloma during chronic inflammation induced by Bacillus Calmette-Guérin (BCG) in the skeletal muscle of Piaractus mesopotamicus, as a histopathology model to study innate immunity. Materials and methods. Sixty fish were divided in two groups: BCG-inoculated and non-inoculated fish and the inflammatory response analyzed 3, 7, 14, 21 and 33 days post-inoculation (DPI) by histopathology after hematoxylin-eosin and Ziehl-Neelsen staining. Results. 3 DPI of BCG showed a diffuse inflammatory reaction mostly composed by mononuclear cells. The inflammation continued diffuse 7 DPI initiating the cellular organization surrounding the inoculum and have continued at 14 DPI with discrete presence of epithelioid-like type cells with acidophilic cytoplasm and floppy chromatin. Higher cellular organization (21 DPI) surrounding the granuloma with intense peripheral mononuclear inflammatory infiltrate and nevertheless, an increase in the number of fibroblasts and macrophage-like cells was observed. The inflammatory process became less diffuse 33 DPI with formation of small amount of granuloma surrounded by the same type of reaction found in bigger granuloma. Both the young and old granuloma presented typical characteristic around the inoculum composed by a layer of epithelioid-like type cells, besides macrophages, some lymphocytes and abundant fibroblasts. Conclusions. This study showed the feasibility in the use of pacus to study chronic granulomatous inflammatory response induced by BCG, characterized by changes in the kinetics of inflammatory cells in skeletal muscle classifying as immune-epithelioid type, similar to granulomatous inflammation caused by M. marinum in teleost fish.Objetivo. Este estudio evaluó la cinética celular y la formación de granuloma durante la inflamación crónica inducida por el Bacilo Calmette-Guérin (BCG) en el músculo esquelético de Piaractus mesopotamicus, como modelo histopatológico para estudiar la inmunidad innata. Materiales y métodos. Sesenta peces fueron divididos en dos grupos: peces inoculados con BCG y no inoculados y la respuesta inflamatoria analizada en 3, 7, 14, 21 y 33 días post-inóculo (DPI) por medio del análisis histopatológico y tinciones de hematoxilina-eosina y Ziehl-Neelsen. Resultados. 3 DPI de BCG se observó reacción inflamatoria difusa principalmente formada por infiltrado celular mononuclear. Al 7° DPI la inflamación continuaba difusa con inicio de organización celular alrededor del inoculo, que se observó hasta el 14° DPI con discreta presencia de células de tipo epiteliodes con citoplasma acidófilo y cromatina laxa. Para el 21° DPI se observó alta organización celular alrededor del granuloma con intenso infiltrado mononuclear periférico e incremento en el número de fibroblastos y macrófagos. El proceso inflamatorio se tornó menos difuso a los 33 DPI con formación de pequeños granulomas contenidos dentro de uno más grande. Los granulomas formados más rápidamente así como los formados tardíamente, presentaron características típicas alrededor del inóculo compuesta por una camada de células tipo epitelioides, macrófagos, linfocitos y fibroblastos. Conclusiones. Este estudio mostró la viabilidad del uso del P. mesopotamicus para estudiar la respuesta inflamatoria crónica granulomatosa inducida con BCG, caracterizado por la evolución de la cinética de células inflamatorias en el músculo esquelético clasificándolo como de tipo inmune-epitelioide, similar a la inflamación granulomatosa causada por M. marinum en peces teleósteos

Preliminary reference values for electrocardiography, echocardiography and myocardial morphometry in the European brown hare (Lepus europaeus)

The study aimed at defining reference values for electrocardiographic (ECG) and echocardiographic parameters as well as macroscopic dimensions of the heart and microscopic dimensions of cardiomyocytes in the European brown hare. The studies were conducted on 30 adult, clinically healthy hares of either sex caught in Poland. ECG and echocardiography were performed supravitally on anaesthetized hares. After euthanasia, gross and microscopic myocardial and cardiomyocyte dimensions were determined. Heart rate amounted to 140 ± 37.5 beats/min, the leading rhythm involved the sinus rhythm. P wave time was 26 ± 5 ms, PQ time was 80 ms, QRS time was 29 ± 3.5 ms, and ST was 97.5 ± 7 ms. Echocardiography determined a left ventricular wall end-diastolic diameter of 8.6 ± 2.0 mm and an intraventricular septum end-diastolic diameter of 5.75 ± 1.0 mm. The thickness of the interventricular septum corresponded to that of the free wall of the left ventricle, a finding consistent with physiological hypertrophy. Preliminary reference values were established for echocardiography. The findings were similar to those obtained at necropsy. The ECG and echocardiographic studies represent the first supravital examination of cardiac function in the hare. The obtained results illustrate adaptation of hare's myocardium to its mode of life. The cardiac findings resemble the athlete's heart syndrome described in humans. The findings may prove useful in further studies on the physiology of the cardio-vascular system in the hare

Management of Bleeding in Exclusive Endoscopic Ear Surgery: Pilot Clinical Experience.

Objective Transcanal exclusive endoscopic ear surgery requires the management of the endoscope and the surgical instruments in the external auditory canal. Bleeding in this narrow space is one of the most challenging issues, especially for novice endoscopic ear surgeons. We aim to assess the severity and occurrence of bleeding and describe strategies to control the bleeding during endoscopic ear surgery. We hypothesize that bleeding is reasonably controllable in endoscopic ear surgery. Study Design Case series with chart review. Setting Tertiary referral center. Subjects and Methods We retrospectively assessed 104 consecutive cases of exclusive endoscopic ear surgery at the University Hospital of Modena, Italy. The surgical videos and the patient charts were carefully investigated and analyzed. Results Hemostatic agents included injection of diluted epinephrine (1:200,000, 2% mepivacaine), cottonoids soaked with epinephrine (1:1000), mono- or bipolar cautery, washing with hydrogen peroxide, and self-suctioning instruments. The localization of bleeding in the external auditory canal was most frequently the posterior superior part, and inside of the middle ear, it was the pathology itself. Statistical analysis revealed significant differences comparing the mean arterial pressure and the type of intervention among bleeding scores. Conclusion The management of bleeding in endoscopic ear surgery is feasible through widely available hemostatic agents in reasonable frequency. This study gives an instructive overview on how to manage the bleeding in the exclusive endoscopic technique. Even the highest bleeding scores could be managed in an exclusively endoscopic technique

Identification of plastic constitutive parameters at large deformations from three dimensional displacement fields

The aim of this paper is to provide a general procedure to extract the constitutive parameters of a plasticity model starting from displacement measurements and using the Virtual Fields Method. This is a classical inverse problem which has been already investigated in the literature, however several new features are developed here. First of all the procedure applies to a general three-dimensional displacement field which leads to large plastic deformations, no assumptions are made such as plane stress or plane strain although only pressure-independent plasticity is considered. Moreover the equilibrium equation is written in terms of the deviatoric stress tensor that can be directly computed from the strain field without iterations. Thanks to this, the identification routine is much faster compared to other inverse methods such as finite element updating. The proposed method can be a valid tool to study complex phenomena which involve severe plastic deformation and where the state of stress is completely triaxial, e.g. strain localization or necking occurrence. The procedure has been validated using a three dimensional displacement field obtained from a simulated experiment. The main potentialities as well as a first sensitivity study on the influence of measurement errors are illustrated

Detection and localization of double compression in MP3 audio tracks

In this work, by exploiting the traces left by double compression in the statistics of quantized modified discrete cosine transform coefficients, a single measure has been derived that allows to decide whether an MP3 file is singly or doubly compressed and, in the last case, to devise also the bit-rate of the first compression. Moreover, the proposed method as well as two state-of-the-art methods have been applied to analyze short temporal windows of the track, allowing the localization of possible tampered portions in the MP3 file under analysis. Experiments confirm the good performance of the proposed scheme and demonstrate that current detection methods are useful for tampering localization, thus offering a new tool for the forensic analysis of MP3 audio tracks

Comparison of sequencing-based methods to profile DNA methylation and identification of monoallelic epigenetic modifications.

Analysis of DNA methylation patterns relies increasingly on sequencing-based profiling methods. The four most frequently used sequencing-based technologies are the bisulfite-based methods MethylC-seq and reduced representation bisulfite sequencing (RRBS), and the enrichment-based techniques methylated DNA immunoprecipitation sequencing (MeDIP-seq) and methylated DNA binding domain sequencing (MBD-seq). We applied all four methods to biological replicates of human embryonic stem cells to assess their genome-wide CpG coverage, resolution, cost, concordance and the influence of CpG density and genomic context. The methylation levels assessed by the two bisulfite methods were concordant (their difference did not exceed a given threshold) for 82% for CpGs and 99% of the non-CpG cytosines. Using binary methylation calls, the two enrichment methods were 99% concordant and regions assessed by all four methods were 97% concordant. We combined MeDIP-seq with methylation-sensitive restriction enzyme (MRE-seq) sequencing for comprehensive methylome coverage at lower cost. This, along with RNA-seq and ChIP-seq of the ES cells enabled us to detect regions with allele-specific epigenetic states, identifying most known imprinted regions and new loci with monoallelic epigenetic marks and monoallelic expression

Clustering and forecasting of dissolved oxygen concentration on a river basin

The aim of this contribution is to combine statistical methodologies to geographically classify homogeneous groups of water quality monitoring sites based on similarities in the temporal dynamics of the dissolved oxygen (DO) concentration, in order to obtain accurate forecasts of this quality variable. Our methodology intends to classify the water quality monitoring sites into spatial homogeneous groups, based on the DO concentration, which has been selected and considered relevant to characterize the water quality. We apply clustering techniques based on Kullback Information, measures that are obtained in the state space modelling process. For each homogeneous group of water quality monitoring sites we model the DO concentration using linear and state space models, which incorporate tendency and seasonality components in different ways. Both approaches are compared by the mean squared error (MSE) of forecasts