ResearchPad - full-length-articles https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Smooth Muscle in Cardiac Chambers is Common in Turtles and Extensive in the Emydid Turtle, <i>Trachemys scripta</i> ]]> https://www.researchpad.co/article/elastic_article_6775 A prominent layer of smooth muscle lining the luminal side of the atria of freshwater turtles (Emydidae) was described more than a century ago. We recently demonstrated that this smooth muscle provides a previously unrecognized mechanism to change cardiac output in the emydid red‐eared slider (Trachemys scripta) that possibly contributes to their tremendous diving capacity. The purpose of the present immunohistochemical study was firstly to screen major groups of vertebrates for the presence of cardiac smooth muscle. Secondly, we investigated the phylogenetic distribution of cardiac smooth muscle within the turtle order (Testudines), including terrestrial and aquatic species. Atrial smooth muscle was not detected in a range of vertebrates, including Xenopus laevis, Alligator mississippiensis, and Caiman crocodilus, all of which have pronounced diving capacities. However, we confirmed earlier reports that traces of smooth muscle are found in human atrial tissue. Only within the turtles (eight species) was there substantial amounts of nonvascular smooth muscle in the heart. This amount was greatest in the atria, while the amount in proportion to cardiac muscle was greater in the sinus venosus than in other chambers. T. scripta had more smooth muscle in the sinus venosus and atria than the other turtles. In some specimens, there was some smooth muscle in the ventricle and the pulmonary vein. Our study demonstrates that cardiac smooth muscle likely appeared early in turtle evolution and has become extensive within the Emydidae family, possibly in association with diving. Across other tetrapod clades, cardiac smooth muscle might not associate with diving. Anat Rec, 303:1327–1336, 2020. © 2019 The Authors. The Anatomical Record published by Wiley Periodicals, Inc. on behalf of American Association for Anatomy.

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<![CDATA[The genomes of three coronaviruses]]> https://www.researchpad.co/article/N442bd022-a9fb-4e17-92b2-c883a540a48b ]]> <![CDATA[Putative papain-related thiol proteases of positive-strand RNA viruses Identification of rubi- and aphthovirus proteases and delineation of a novel conserved domain associated with proteases of rubi-, α- and coronaviruses]]> https://www.researchpad.co/article/Nd2064473-2547-4782-a8ee-182e74f7d259

A computer‐assisted comparative analysis of the amino acid sequences of (putative) thiol proteases encoded by the genomes of several diverse groups or positive‐stranded RNA viruses and distantly related to the family of cellular papain‐like proteases is presented. A high level of similarity was detected between the leader protease of foot‐and‐mouth‐disease virus and the protease of murine hepatitis coronavirus which cleaves the N‐terminal p28 protein from the polyprotein. Statistically significant alignment of a portion of the rubella virus polyprotein with cellular papain‐like proteases was obtained, leading to tentative identification of the papain‐like protease as the enzyme mediating processing of the non‐structural proteins of this virus. Specific grouping between the sequences of the proteases of α‐viruses, and poty‐ and bymoviruses was revealed. It was noted that papain‐like proteases of positive‐stranded RNA viruses are much more variable both in their sequences and in genomic locations than chymotrypsin‐related proteases found in the same virus class. A novel conserved domain of unknown function has also been identified which flanks the papain‐like proteases of α‐, rubi‐ and coronaviruses.

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<![CDATA[Endosomal association of a protein phosphatase with high dephosphorylating activity against a coronavirus nucleocapsid protein]]> https://www.researchpad.co/article/N020c7222-9555-416d-be56-a8a0619e2c74

On the assumption that dephosphorylation of the neurotropic coronavirus JHM (JHMV) nucleocapsid protein (N) may be connected with initiation of the infectious cycle we searched for a relevant host enzyme activity. Analysis of subcellular fractions from L‐2 murine fibroblasts, separated by dual Percoll density gradients, revealed the presence of a phosphoprotein phosphatase (PPPase), co‐sedimenting with the endososomal/prelysosomal material, which possesses high activity against N. With purified [22P]N as substrate it was demonstrated that this PPPase, distinguishable from acid and alkaline phosphatases, acts optimally at neutral pH in the presence of Mn2+ following treatment with a detergent. Complete inhibition with okadaic acid at 0.9–4.5 μM but not at 1–10 nM relegates this PPase to a type I protein phosphatase. Similar PPPase activity for N was present in the endosome fraction of a rat Roc‐1 astrocytoma‐oligodendrocyte cell line and in homogenates of brain and cultured oligodendrocytes. Our data suggest that the phosphorylated N of the inoculum may be modified by the endosomal PPPase in host cells, including those from the CNS so as to facilitate the JHMV infectious process.

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<![CDATA[Ultrastructural Characterization of Stem Cell‐Derived Replacement Vestibular Hair Cells Within Ototoxin‐Damaged Rat Utricle Explants]]> https://www.researchpad.co/article/N92e4b900-3257-4cda-89c5-e78f2b516ad3

ABSTRACT

The auditory apparatus of the inner ear does not show turnover of sensory hair cells (HCs) in adult mammals; in contrast, there are many observations supporting low‐level turnover of vestibular HCs within the balance organs of mammalian inner ears. This low‐level renewal of vestibular HCs exists during normal conditions and it is further enhanced after trauma‐induced loss of these HCs. The main process for renewal of HCs within mammalian vestibular epithelia is a conversion/transdifferentiation of existing supporting cells (SCs) into replacement HCs.In earlier studies using long‐term organ cultures of postnatal rat macula utriculi, HC loss induced by gentamicin resulted in an initial substantial decline in HC density followed by a significant increase in the proportion of HCs to SCs indicating the production of replacement HCs. In the present study, using the same model of ototoxic damage to study renewal of vestibular HCs, we focus on the ultrastructural characteristics of SCs undergoing transdifferentiation into new HCs. Our objective was to search for morphological signs of SC plasticity during this process. In the utricular epithelia, we observed immature HCs, which appear to be SCs transdifferentiating into HCs. These bridge SCs have unique morphological features characterized by formation of foot processes, basal accumulation of mitochondria, and an increased amount of connections with nearby SCs. No gap junctions were observed on these transitional cells. The tight junction seals were morphologically intact in both control and gentamicin‐exposed explants. Anat Rec, 303:506–515, 2020. © 2019 The Authors. The Anatomical Record published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists.

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<![CDATA[Trust in the European Union: Effects of the information environment]]> https://www.researchpad.co/article/5c973a60d5eed0c484965654

Over the past decade, the European Union has lost the trust of many citizens. This article investigates whether and how media information, in particular visibility and tonality, impact trust in the European Union among citizens. Combining content analysis and Eurobarometer survey data from 10 countries between 2004 and 2015, we study both direct and moderating media effects. Media tone and visibility have limited direct effects on trust in the European Union, but they moderate the relation between trust in national institutions and trust in the European Union. This relation is amplified when the European Union is more visible in the media and when media tone is more positive towards the European Union, whereas it is dampened when media tone is more negative. The findings highlight the role of news media in the crisis of trust in the European Union.

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<![CDATA[Prognostic factors for return to work and resumption of other daily activities after traumatic hand injury]]> https://www.researchpad.co/article/5c79af86d5eed0c4841e3204

The purpose of this study was to investigate prognostic factors for the time off work, the time to resumption of activities of daily living and hobbies, and duration of complaints in patients with a traumatic hand or wrist injury. In a 10-month longitudinal prospective cohort study, 383 patients were included and interviewed in person every 2 to 3 months. Several sociodemographic, psychological and work-related prognostic factors were investigated. For the time off work, job type, diagnosis, complication, blaming someone else for the trauma and gender were all found to be individual prognostic factors in Cox regression. For the time to resumption of activities of daily living and hobbies, and duration of complaints, gender, diagnosis, treatment and complications were found to be prognostic factors in univariate analysis. Age was solely correlated with resumption of activities of daily living and the duration of complaints. Considering these prognostic factors can help predict a patient’s recovery more accurately.

Level of evidence: II

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<![CDATA[Up with ecology, down with economy? The consolidation of the idea of climate change mitigation in the global public sphere]]> https://www.researchpad.co/article/5c2a77bed5eed0c484227906

Building on theories of valuation and evaluation, we develop an analytical framework that outlines six elements of the process of consolidation of an idea in the public sphere. We then use the framework to analyse the process of consolidation of the idea of climate change mitigation between 1997 and 2013, focusing on the interplay between ecological and economic evaluations. Our content analysis of 1274 articles in leading newspapers in five countries around the globe shows that (1) ecological arguments increase over time, (2) economic arguments decrease over time, (3) the visibility of environmental nongovernmental organizations as carriers of ecological ideas increases over time, (4) the visibility of business actors correspondingly decreases, (5) ecological ideas are increasingly adopted by political and business elites and (6) a compromise emerges between ecological and economic evaluations, in the form of the argument that climate change mitigation boosts, rather than hinders economic growth.

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