1,720,974 research outputs found
Rimodellamento dei complessi giunzionali dei cardiomiociti nelle cardiomiopatie: dal modello sperimentale all'uomo
Get PDFLe cardiomiopatie sono patologie del cuore associate a disfunzione cardiaca, caratterizzate da alterazioni strutturali a carico dei cardiomiociti e della loro organizzazione tessutale.
I dischi intercalari sono zone di contatto e adesione tra le membrane plasmatiche di cardiomiociti contigui e sono costituiti da giunzioni di membrana altamente specializzate: le giunzioni aderenti, i desmosomi e le giunzioni comunicanti.
In questo studio è stato analizzato il rimodellamento dei dischi intercalari in corso di cardiomiopatia ipertrofica e dilatativa ereditaria, utilizzando i modelli sperimentali di criceti cardiomiopatici UMX7.1 e TO2, geneticamente privi del δ-sarcoglicano.
L’analisi ultrastrutturale di cuori di criceti cardiomiopatici ha evidenziato la disorganizzazione tissutale nei cuori di criceti UMX7.1, con dischi intercalari disorganizzati e aumentati di numero. Nei cuori di criceti TO2 si è rivelata peculiare la presenza di desmosomi e giunzioni comunicanti anche a livello della membrana laterale di cardiomiociti adiacenti.
L’analisi immunoistochimica ha evidenziato un aumento di espressione di N-caderina e β-catenina nei criceti UMX7.1 rispetto ai controlli, mentre nei criceti TO2 è risultata peculiare la distribuzione di connessina 43 a livello delle membrane laterali dei cardiomiociti.
Sono stati quindi analizzati mediante immunoistochimica campioni di tessuto miocardico provenienti da quarantaquattro pazienti sottoposti a trapianto cardiaco affetti da cardiomiopatia dilatativa idiomatica, da cardiomiopatia dilatativa genetica nota; da cardiomiopatia dilatativa secondaria e infine da cardiomiopatia ipertrofica idiopatica.
L’analisi immunoistochimica ha rilevato un aumento di espressione di N-caderina importante nelle cardiomiopatie dilatative secondarie e meno diffuso negli altri casi, e un uniforme aumento di β-catenina. Inoltre nella maggior parte dei casi analizzati è stata osservata una delocalizzazione di connessina 43 a livello della superficie laterale dei cardiomiociti.
Considerate, infine, le evidenze cliniche e sperimentali che supportano il ruolo antiinfiammatorio e cardioprotettivo degli acidi grassi ω-3, in questo studio si è voluto analizzare l’effetto che una dieta arricchita di acidi grassi ω-3 ha sul rimodellamento cardiaco in modello sperimentale di criceti UMX7.1.
Criceti cardiomiopatici UMX7.1 e criceti sani sono stati nutriti con dieta standard, mentre un altro gruppo di criceti CMPH è stato invece nutrito con dieta arricchita in ALA. E’ stata analizzata l’espressione delle molecole del disco intercalare mediante western blotting, analisi immunoistochimica e analisi ultrastrutturale; tali analisi hanno mostrato complessivamente che la dieta arricchita in ALA ripristina almeno in parte l’organizzazione strutturale del tessuto miocardico in criceti cardiomiopatici.
In conclusione in questo studio è stato analizzato il rimodellamento dei cardiomiociti in corso di cardiomiopatia sperimentale e umana ed è stato dimostrato l’effetto benefico di una dieta arricchita in acidi grassi ω-3 sulla struttura dei dischi intercalari e sulla loro composizione molecolare, suggerendo, quindi, il potenziale uso di acidi grassi ω-3 nella prevenzione di aritmie potenzialmente dannose in corso di patologie cardiache.Cardiomyopathies are cardiac diseases associated to cardiac disfunction, caracterized by structural alterations of cardiomyocytes and their tissutal organization.
Intercalated disks are adhesion structures between plasmatic membranes of cardiomyocytes, made of highly specialized membrane junctions: adherens junctions, desmosomes and gap junctions.
The present investigation evaluated intercalated disks remodelling during hypertrophic and dilatative cardiomyopathies, in UMX7.1 and TO2 δ-sarcoglican-deficient hamsters.
Hamsters hearts ultrastructural analysis showed that the ordered organization is lost in UMX7.1 hearts, where intercalated disks appear chaotically located and structural swirling. In TO2 hamsters, desmosomes and gap junctions are located on the lateral plasmalemma.
Immunohistochemistry showed an increase in expression levels of N-cadherin and β-catenin in UMX7.1 hamsters, while connexin 43 appears located on the lateral plasmalemma in TO2 hamsters.
Myocardiac tissue samples from 44 patients affected by idiopathic dilatative cardiomyopathy, genetic dilatative cardiomyopathy, secondary dilatative cardiomyopathy and hypertrophic idiopathic cardiomyopathy were analized by immunohistochemistry.
The analysis showed a high increased in N-cadherin in secondary dilatatve cardiomyopathies and an uniform increase in β-catenin. Then, in most of the samples observed, connexin 43 appears located on the lateral plasmalemma.
Since a lot of clinical and experimental dates show omega-3 essential fatty acids anti-inflammatory and cardioprotective role, in the present investigation it the effect of an ALA- enriched diet on cardiac remodelling in UMX7.1 hamsters has been evaluated.
UMX7.1 hamsters and healthy hamsters were fed with standard diet, while a different group of UMX7.1 hamsters was fed with ALA-enriched diet.
Intercalated disk molecules expression was evaluated by western blotting, immunohistochemistry and ultrustructural analysis; on the whole, the ALA-enriched diet demonstrates its effects in counteracting the pathological alterations in cardiomyopathic hamsters.
Collectively, the present investigation evaluated cardiomyocytes remodelling during experimental and human cardiomyopathy and showed the beneficial effect of an ALA- enriched diet on cardiomyocyte intercalated disk structure and molecular composition; furthermore, it supported the potential use of ω-3 polyunsatured fatty acids in the prevention of potentially dangerous arrhytmias in cardiac diseases.
Key words: cardiomyopathy, intercalated disks, ω-3 polyunsatured fatty acids, arrhytmia, connexin 43
Actin cytoskeleton dynamics and type i ifn-mediated immune response: a dangerous liaison in cancer?
Get PDFChronic viral infection and cancer are closely inter-related and are both characterized by profound alteration of tissue homeostasis. The actin cytoskeleton dynamics highly participate in tissue homeostasis and act as a sensor leading to an immune-mediated anti-cancer and anti-viral response. Herein we highlight the crucial role of actin cytoskeleton dynamics in participating in a viral mimicry activation with profound effect in anti-tumor immune response. This still poorly explored field understands the cytoskeleton dynamics as a platform of complex signaling pathways which may regulate Type I IFN response in cancer. This emerging network needs to be elucidated to identify more effective anti-cancer strategies and to further advance the immuno-oncology field which has revolutionized the cancer treatment. For a progress to occur in this exciting arena we have to shed light on actin cytoskeleton related pathways and immune response. Herein we summarize the major findings, considering the double sword of the immune response and in particular the role of Type I IFN pathways in resistance to anti-cancer treatment
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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