1,720,965 research outputs found
In vitro prediction of response to hCG therapy in patients with cryptorchidism and testicular torsion in a gubernaculum-based model
Full text linkLe malattie andrologiche che colpiscono i pazienti in età pediatrica rappresentano un importante fattore di rischio per l’alterazione del loro potenziale fertile in età adulta e, pertanto, la diagnosi ed il trattamento precoce, anche chirurgico e/o terapeutico, sono estremamente importanti. Il fattore di rischio meglio caratterizzato per l’infertilità in età adulta, così come per lo sviluppo del cancro testicolare, è rappresentato dal criptorchidismo, in cui si verifica l’assenza di uno o entrambi i testicoli nella sacca scrotale alla nascita. L'approccio più efficace per il trattamento del criptorchidismo è l'orchidopessi seguita dalla terapia con gonadotropina corionica umana (hCG); tuttavia, non tutti i pazienti mostrano un miglioramento significativo del volume e della vascolarizzazione dei testicoli dopo la terapia adiuvante. In questo studio, abbiamo generato un modello in vitro per prevedere la risposta del paziente all'hCG, attraverso la coltura e il trattamento di cellule primarie derivate da biopsie di gubernaculum testis - il legamento che collega il testicolo allo scroto - di quattro pazienti criptorchidi. Il gubernaculum condivide molte proprietà con le cellule testicolari, inclusa l'espressione del recettore dell’hCG (LHCGR), data la loro comune origine embrionale. In questo lavoro, mostriamo che l'hCG stimola le cellule gubernacolari a proliferare e a formare strutture simili a vasi con un'entità diversa tra le cellule derivate dai 4 pazienti, insieme ad una riduzione sia del consumo di ossigeno che di generazione delle specie reattive dell'ossigeno. Con queste osservazioni, mostriamo che la diversa risposta dei pazienti all'hCG può essere attribuibile alla loro età, poiché i pazienti più giovani rispondono meglio in vitro all'ormone. Oltre al criptorchidismo, anche la torsione testicolare rappresenta una condizione urgente che può influenzare negativamente il potenziale di fertilità. Questa patologia si manifesta in soggetti giovani generalmente prima dei 25 anni per i quali attualmente non è prevista alcuna terapia nella fase postoperatoria. In questo studio mostriamo anche che le cellule gubernacolari derivate da pazienti affetti da torsione testicolare possono essere coltivate e amplificate in vitro per testare l'efficacia della terapia con hCG, la cui applicazione è quindi adeguata anche in questa condizione patologica per recuperare la funzionalità testicolare. Infine, per comprendere meglio le proprietà del tessuto testicolare e le sue funzionalità, abbiamo generato e caratterizzato un sistema di coltura tridimensionale di organoidi testicolari umani, a partire da un pezzo di biopsia del tessuto testicolare. Nel complesso, i risultati di questa tesi aprono la strada alla futura applicazione del nostro modello di gubernaculum in vitro – preservando il prezioso tessuto testicolare – per prevedere la migliore terapia personalizzata per i pazienti criptorchidi e per supportare il recupero dei testicoli nei pazienti affetti da torsione testicolare.Andrological diseases that affect patients in pediatric age represent important risk factors for alterations of their fertile potential in adulthood and, therefore, early diagnosis and treatment, even surgical and/or therapeutic treatments, are extremely important. The best-characterized risk factor for infertility in adulthood but also for testicular cancer development is represented by cryptorchidism, which is the absence of one or both testicles in the scrotal sac at birth. The most effective approach to treat cryptorchidism is orchidopexy followed by human chorionic gonadotropin (hCG) therapy; however, not all patients show a significant improvement of testis volume and vascularization after adjuvant therapy. In this study, we generated an in vitro model to predict the patient response to hCG by cultivating and treating primary cells derived from four cryptorchid patients’ biopsies of gubernaculum testis, the ligament that connects the testicle to the scrotum. Gubernaculum shares many properties with testicular cells, including the expression of the hCG receptor (LHCGR), due to their common embryonic origin. Here, we show that hCG stimulates gubernacular cells to proliferate and to form vessel-like structures with a different extent among the four patients derived cells, together with a decrease of both oxygen consumption and reactive oxygen species generation. Hereby, we show that the diverse patient response to hCG may be ascribable to their age, as younger patients respond better in vitro to the hormone. In addition to cryptorchidism, testicular torsion also represents an urgent condition that may negatively influence the fertility potential. This pathology occurs in young men generally before the age of 25 for which a therapeutic approach is not currently considered in the postoperative phase. In this study, we also show that gubernacular cells derived from patients affected by testicular torsion can be cultured and amplified in vitro to test the efficacy of hCG therapy, which can also be used in this pathological condition to recover function of the testes. Finally, to better understand the properties of testicular tissue and its functionalities, we generated and characterized a three-dimensional human testicular organoid culture system, starting from a piece of testicular tissue biopsy. Altogether, the findings of this thesis pave the way to the future application of our in vitro gubernaculum model – preserving precious testicular tissue - to predict the best personalized therapy for cryptorchid patients and to support the testis recover in patients affected by testicular torsion
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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
Testicular Torsion: Preliminary Results of In Vitro Cell Stimulation Using Chorionic Gonadotropin
Full text linkTesticular torsion is a pathology that occurs in young males generally before the age of 25. Despite surgery representing the only effective approach, there is still a need to identify a marker that can predict whether a preserved testicle will be functional. In addition, no therapeutic approach is currently considered in the post-operative phase. Through an approach based on the in vitro culture of a tissue strictly linked to the testicle, the gubernaculum, we defined the healthy state of the organ and the possible responsiveness to a therapy used in the andrology field, chorionic gonadotropin (hCG). Firstly, we optimized a protocol to obtain viable cells starting from a small piece of gubernacular tissue harvested during surgery with the aim to amplify cells in vitro. Intriguingly, only for a patient whose testicle had been removed during surgery due to an excessive necrotic area, gubernacular cells were not able to grow in culture. These data support the possibility of exploiting the gubernaculum to evaluate the healthy state of the testicle. Then, as we demonstrate that gubernacular cells express a luteinizing hormone receptor, to which hCG is specific, we analyzed the cellular response to hCG treatment on in vitro cultured cells derived from patients affected by testicular torsion. Our study opens the way for the possibility of evaluating testicle wellbeing after derotation through in vitro culture of a small piece of gubernaculum together with predicting the response to the treatment with hCG, which can have a positive effect on cell proliferation and vascularization
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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