Excitatory actions of GABA in developing chick vestibular afferents: Effects on resting electrical activity

The aim of this study was to characterize the effect of γ-aminobutyric acid (GABA) in the resting multiunit activity of the vestibular afferents during development using the isolated inner ear of embryonic and postnatal chickens (E15-E21 and P5). GABA (10⁻³ to 10⁻⁵ M; n = 133) and muscimol (10⁻³M) elicited an increase in the frequency of the basal discharge of the vestibular afferents. We found that GABA action was dose-dependent and inversely related to animal age. Thus, the largest effect was observed in embryonic ages such as E15 and E17 and decreases in E21 and P5. The GABA_A receptor antagonists, bicuculline (10⁻⁵M; n = 10) and picrotoxin (10⁻⁴M; n = 10), significantly decreased the excitatory action of GABA and muscimol (10⁻³M). Additionally, CNQX 10⁻⁶M, MCPG 10⁻⁵M and 7ClKyn 10⁻⁵M (n = 5) were co-applied by bath substitution (n = 5). Both the basal discharge and the GABA action significantly decreased in these experimental conditions. The chloride channel blocker 9-AC 0.5 mM produced an important reduction in the effect of GABA 10⁻³ (n = 5) and 10⁻⁴M (n = 5). Thus, our results suggest an excitatory role of GABA in the resting activity of the vestibular afferents that can be explained by changes in the gradient of concentration of Cl⁻ during development. We show for the first time that the magnitude of this GABA effect decreases at later stages of embryonic and early postnatal development. Taking into account the results with glutamatergic antagonists, we conclude that GABA has a presynaptic action but is not the neurotransmitter in the vestibular afferent synapses, although it could act as a facilitator of the spontaneous activity and may regulate glutamate release. Synapse 67:374–381, 2013. © 2013 Wiley Periodicals, Inc.     

Influence of etiologic factors in peri-implantitis: literature review and case report

Peri-implantitis is a pathology that has been described in many clinical studies and case reports. However, it is still not clear how the roles of its etiologic agents work. This article is based on a review of the literature and a case report. It aims to offer data related to the factors that cause this pathology, and to analyze how these factors interact, leading to the contamination of the peri-implant tissue.     

Impact of the number of prior chemotherapy regimens on outcomes for patients with metastatic breast cancer treated with eribulin: A post hoc pooled analysis

In a pivotal phase 3 study (Study 305), eribulin mesylate improved overall survival (OS) in patients with previously treated metastatic breast cancer (MBC) compared with treatment of physician's choice (TPC). This post hoc, pooled subgroup analysis of two phase 3 studies (Study 305 and Study 301) reports the influence of the number of prior chemotherapy regimens (0‐6) on OS in patients with locally advanced/MBC randomized to eribulin versus TPC/capecitabine. Patients with ≤ 3 prior chemotherapies for locally advanced/MBC had longer median OS with eribulin (15.3 months) versus control (13.2 months; hazard ratio, 0.858; P = .01).     

Imaging and monitoring in minimally invasive valve surgery using an intra-aortic occlusion device: a single center experience

BackgroundMinimally invasive approach through a right mini-thoracotomy is a world-wide used procedure for mitral valve surgery. We performed a retrospective analysis based on our center experience in order to propose an effective, safe and reproducible method using an intra-aortic occlusion device.MethodsThis is a retrospective analysis on 48 consecutive patients undergoing mitral valve surgery through a right anterolateral mini-thoracotomy in our center. An intra-aortic occlusion device was used for aortic clamping and cardioplegia delivery. Simultaneous multi-plane three-dimensional echocardiography imaging was acquired to detect the venous cannulas position, the intra-aortic device location in the ascending aorta, the balloon inflation, the complete occlusion of the aorta, the cardioplegia delivery, the origin and the blood flow in the right coronary artery. Aortic root pressure was measured by the tip of the intra-aortic occlusion device. A bilateral upper extremity invasive arterial pressure monitoring was detected. Neuromonitoring was performed through bilateral cerebral oximetry.ResultsThe analysis has shown no aortic dissection, neurological damage type 1 and myocardial ischemia in the study population. In 3 cases a distal displacement of the intra-aortic occlusion device was promptly detected by the combined use of echocardiographic imaging and by a drop of the right cerebral oximetry saturation and of the right radial artery pressure.ConclusionsThe combined use of transesophageal simultaneous multi-plane three- dimensional echocardiography imaging, bilateral upper extremity invasive arterial pressure monitoring, aortic root pressure and cerebral oximetry is an effective, safe and reproducible method in patients undergoing minimally invasive valve surgery using an intra-aortic occlusion device.