Tight junctions and the modulation of barrier function in disease

Tight junctions create a paracellular barrier in epithelial and endothelial cells protecting them from the external environment. Two different classes of integral membrane proteins constitute the tight junction strands in epithelial cells and endothelial cells, occludin and members of the claudin protein family. In addition, cytoplasmic scaffolding molecules associated with these junctions regulate diverse physiological processes like proliferation, cell polarity and regulated diffusion. In many diseases, disruption of this regulated barrier occurs. This review will briefly describe the molecular composition of the tight junctions and then present evidence of the link between tight junction dysfunction and disease

Quintus Mucius Scaevola. Opera

La figura e il pensiero di Quinto Mucio Scevola (140 circa - 82 a.C.; console nel 95), uno dei fondatori del pensiero giuridico romano, vengono presentati per la prima volta in questo volume, che inaugura una nuova Collana dell'Erma di Bretschneider dedicata agli Scriptores iuris Romani, inserita nel contesto di una ricerca finanziata dall'European Research Council (ERC Advanced Grant 2014, diretta da Aldo Schiavone; Host Institution il Dipartimento di Scienze Giuridiche della Sapienza, Universita di Roma). Quinto Mucio, giurista e teologo, protagonista della vita politica romana in uno dei periodi piu convulsi dell'eta repubblicana, e stato il primo autore di un trattato di diritto civile, in 18 libri, in cui rivelava sia la sua conoscenza della filosofia greca, sia il suo talento di innovatore rispetto alla tradizione giuridica precedente. Alla sensibilita interpretativa di Jean-Louis Ferrary, Aldo Schiavone, Emanuele Stolfi, si deve la ricostruzione della biografia di Quinto Mucio e dell'intera sua opera, realizzata attraverso un attento lavoro di restituzione testuale e resa accessibile grazie alla traduzione dei piu di cento frammenti tramandati, ciascuno dei quali e stato sottoposto ad un ampio commento analitico

Cochlear Implant Insertion Axis into the Basal Turn: A Critical Factor in Electrode Array Translocation

Hypothesis: An inappropriate insertion axis leads to intracochlear trauma during cochlear implantation (CI). Background: Few studies assessed the relationship between the insertion axis and the electrode scalar location. Methods: Preimplantation cone-beam CT (CBCT) was performed on 12 human temporal bones. In five temporal bones, an optimal insertion axis was planned, due to the impossibility to attain the ST centerline from the posterior tympanotomy, because of facial canal position. In the seven other temporal bones, an inaccurate insertion axis was intentionally planned (optimal axis+15 degrees). Automated CI array insertion according to the planned axis was performed with a motorized insertion tool driven by a navigated robot-based arm. The cochlea and basilar membrane were segmented from the preimplantation CBCT and the array segmented from the postimplantation CBCT to construct a merged final three-dimensional (3D) model. Microscopical and 3D analysis were performed to determine the intracochlear trauma at the level of each electrode. Results: A good agreement was observed in determining electrode position between microscopic analysis and the 3D model (Cohen's kappa k = 0.67). The angle of approach to the ST centerline was associated with the number of electrodes inserted into the ST (r = -0.65, p = 0.02, [95% CI -0.90 to -0.11] Spearman's rank correlation). Conclusion: A 3D reconstruction model was effective in determining the array position in the cochlea scalae. Our data indicate that the angle of approach to the ST centerline is a critical factor in intracochlear trauma. Additional studies should be conducted to assess the importance of the insertion axis with other array designs

Variability of the mental representation of the cochlear anatomy during cochlear implantation

The aim of this study was to assess the mental representation of the insertion axis of surgeons with different degrees of experience, and reproducibility of the insertion axis in repeated measures. A mastoidectomy and a posterior tympanotomy were prepared in five different artificial temporal bones. A cone-beam CT was performed for each temporal bone and the data were registered on a magnetic navigation system. In these five temporal bones, 16 surgeons (3 experts; >50 cochlear implant surgery/year; 7 fellows with few cochlear implant experience, and 6 residents) were asked to determine the optimal insertion axis according to their mental representation. Compared to a planned ideal axis, the insertion axis was better determined by the experts with higher accuracy (axial: 7° ± 1.5°, coronal: 6° ± 1.5°) than fellows (axial: 14° ± 1.7°, coronal: 13° ± 1.7°; p < 0.05), or residents (axial: 15° ± 1.5°; p < 0.001, coronal: 17° ± 1.9°; p < 0.001). This study suggests that mental representation of the cochlea is experience-dependent. A high variation of the insertion axis to the scala tympani can be observed due to the complexity of the temporal bone anatomy and lack of landmarks to determine scala tympani orientation. Navigation systems can be used to evaluate and improve mental representation of the insertion axis to the scala tympani for cochlear implant surgery