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Neuropatie ottiche
No full textLe neuropatie ottiche sono condizioni degenerative ereditarie o acquisite che coinvolgono il secondo paio dei nervi cranici. Si tratta di affezioni su base ischemica, demienilizzante, parainfettiva, tossica, carenziale, compressiva, infiltrativa ed eredo-familiare. A causa del danno diretto ed indiretto delle cellule ganglionari retiniche e dei loro assoni, il risultato comune delle neuropatie ottiche è una modificazione della testa del nervo ottico e del circostante strato delle fibre nervose retiniche. Gli Autori descrivono le forme più comuni di neuropatie ottiche soffermandosi sugli aspetti clinici e diagnostici
Neuroprotezione nel glaucoma: ruolo dell’epigallocatechinagallato (ECGg)
No full textIl glaucoma, seconda causa di cecità nei paesi industrializzati, è una sindrome caratterizzata da neuropatia ottica ad evoluzione progressiva e tipici difetti del campo visivo, nella quale l’aumento della pressione intraoculare (IOP) è
il principale fattore di rischio.
Essendo la patologia glaucomatosa una malattia
multifattoriale si è cercato di individuare gli altri fattori di rischio, tra i quali è emerso che lo stress ossidativo e i radicali liberi sono importanti agenti eziologici coinvolti nei cambiamenti morfologici e funzionali riscontrati
nel glaucoma e tipici delle patologie degenerative.
La scoperta dell’importanza dei radicali liberi come agenti eziologici ha aperto il campo a molte sperimentazioni con agenti antiossidanti e scavenger atti a ridurre lo
stress ossidativo con effetto neuroprotettivo
tra cui prendiamo in considerazione l’epigallocatechinagallato
Neuroprotezione nel glaucoma: ruolo della citicolina
No full textIl glaucoma è una patologia degenerativa che colpisce le cellule gangliari retiniche del nervo ottico dando luogo ad una progressiva escavazione della papilla ottica, dal punto di vista
anatomopatologo, che si traduce nella progressiva perdita del campo visivo.
Essendo una patologia ad andamento progressivo gli sforzi clinici e medici mirano a raggiungere l’arresto della degenerazione cellulare attraverso quella che viene chiamata neuroprotezione.
Numerose sostanze sono state e sono tutt’ora oggetto di studio per raggiungere tale scopo in modi e tempi differenti.
La citicolina, a questo proposito, sembra avere un’azione neuroprotettiva, confermata, da studi in vivo ed in vitro, nei confronti delle cellule gangliari retiniche che vanno incontro ad
apoptosi. Questa molecola è un nucleoside endogeno
precursore della fosfatidilcolina, componente indispensabile per la sintesi dei fosfolipidi, che ha varie azioni all’interno della cellula, tra cui il mantenimento di una membrana
plasmatica e mitocondriale strutturalmente integre e l’azione antiossidante che impedisce la degradazione della fosfatidilcolina in acidi grassi con conseguente produzione dei radicali liberi dell’ossigeno
Neuroprotezione nel glaucoma: ruolo della acetil-L-carnitina
No full textIl glaucoma è un’importante causa di cecità nel mondo e si presenta come una sindrome caratterizzata da neurotticopatia progressiva e difetti del campo visivo. Dal punto di vista eziopatogenetico, il glaucoma è una malattia
multifattoriale di cui è stata individuata un’ampia varietà di fattori causali importanti nella genesi dell’insulto a cui vengono esposte le cellule gangliari retiniche accanto al fattore
di rischio più importante quale la pressione intraoculare (IOP).
In primo luogo gli astrociti, normali costituenti del tessuto nervoso del nervo ottico, che possono andare incontro ad attivazione eccessiva provocando morte dei neuroni.
Importante è il ruolo delle eccitotossine e in particolar modo del glutammato che provocando un’eccessiva stimolazione del neurone post-sinaptico, ne determina la sua morte.
L’ossido nitrico e le endoteline possono partecipare
alla cascata di eventi che determinano apoptosi cellulare agendo sulla vascolarizzazione, sulla IOP e direttamente nelle vie intracellulari di attivazione dell’apoptosi. Anche lo
stress ossidativo sembra essere implicato nella morte dei neuroni determinando denaturazione proteica, perossidazione lipidica e produzione di fattori chemiotattici.
Riveste perciò particolare importanza la neuroprotezione
e le sostanze riconosciute come neuroprotettrici quali la acetil-L-carnitina (ALCAR), molecola endogena con molteplici
azioni fisiologiche che potenziando il metabolismo cellulare e la sua efficienza permette di rendere le cellule gangliare retiniche più resistenti agli insulti
Intracranial aneurysm and diplopia due to oculomotor nerve palsy: pre- and post operative study
No full textPurpose
The aim of this study was to analyze ocular signs and symptoms in patients with oculomotor nerve palsy due to compression exerted by an intracranial aneurysm. We compare the results of two surgical treatments (microsurgical clipping against endovascular embolisation) in relation with the size of the aneurysm and the time between diagnosis and therapeutical approach
Materials and Methods
The study involved 16 patients. Each patient underwent an ophthalmological evaluation at the baseline and immediately, 6 months and 1 year after surgery, including the study of eyelid ptosis, ocular motility, pupil function, non-concomitant strabismus, diplopia and visual acuity
Results
The best recovery was seen in the patients undergoing aneurysm clipping. Palpebral ptosis was the first sign to appear and the first to regress, followed by pupil and medial rectus function. Recovery of the other muscles was slower and often incomplete
Conclusions
Ophthalmological examination is essential for the correct treatment and follow-up of patients with intracranial aneurysmsPURPOSE: The aim of this study was to analyze ocular signs and symptoms in patients with oculomotor nerve palsy due to compression exerted by an intracranial aneurysm. We compare the results of two surgical treatments (microsurgical clipping against endovascular embolisation) in relation with the size of the aneurysm and the time between diagnosis and therapeutical approach.
MATERIALS AND METHODS: The study involved 16 patients. Each patient underwent an ophthalmological evaluation at the baseline and immediately, 6 months and 1 year after surgery, including the study of eyelid ptosis, ocular motility, pupil function, non-concomitant strabismus, diplopia and visual acuity.
RESULTS: The best recovery was seen in the patients undergoing aneurysm clipping. Palpebral ptosis was the first sign to appear and the first to regress, followed by pupil and medial rectus function. Recovery of the other muscles was slower and often incomplete.
CONCLUSIONS: Ophthalmological examination is essent
Role of Fluoroquinolones in Diplopia After Retinal Detachment Surgery
No full textIntroduction: to assess the role of systemic therapy with fluoroquinolones
in patients with diplopia after retinal detachment
surgery, considering the effects of these antibiotics on tendons and
muscles as evidenced in literature.
Methods or Study Design: 30 patients with diplopia after retinal
detachment surgery (P group) and 30 patients without diplopia
after surgery (N group) were examined retrospectively. Systemic
and ocular conditions, systemic and ocular therapy, type of surgical
procedures, refraction and visual acuity before and after surgery,
type of diplopia were evaluated. The survey has been particularly
concerned with the type of antibiotic and steroid systemic
therapy administered, the duration of both therapies and the appearance
of diplopia according to the time of administration. Statistical
analysis: Chi-squared Test, Anova one way and Mann-
Whitney test. In addition, we examined the Odds Ratio (OR), the
Confidence interval (CI) and we considered as significative p values
= 0.004.
Results: The risk of diplopia after retinal detachment surgery
is associated with fluoroquinolones and macrolides therapy. 11
patients of the P group and 3 of the N group underwent administration
of fluoroquinolones, while 7 patients in the P group and 1
patient in the N group took macrolides. The Odds Ratio in these
patients was 9.5 (CI} 95%, range 1.6–62), so the risk of developing
diplopia was eight times higher in the P group than in the N
group. Patients in the P group presented an early appearance of
diplopia; they also showed a longer period of antibiotic and steroid
therapy than those in N group (8.9 days vs 4.9 days for systemic
antibiotic therapy, 19.5 days vs 6.9 days for systemic steroid
therapy).
Conclusions: Diplopia after retinal detachment surgery can be
related not only to the kind of surgical procedure, but also to the
systemic administration of fluoroquinolones or macrolides and to
the period of antibiotic therapy
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
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