Evaluation of low-viscosity bulk-fill composites regarding marginal and internal adaptation

This study aimed at evaluating the marginal and internal adaptation of low-viscosity bulk-fill composites to enamel and dentin using a self-etch or an etch-and-rinse adhesive without and with artificial ageing. Hundred and twenty-eight MOD cavities in extracted molars were assigned to eight groups (n = 16), restored with the adhesives OptiBond FL (OFL) or Xeno V+ (X) and two low-viscosity bulk-fill composites SDR or x-tra base, covered with Premise. Tetric EvoCeram Bulk Fill and Premise served as a control. n = 8 per group were subjected to prolonged water storage (180 days) and thermocycling (2500×). Scanning electron microscopy was used to determine marginal gaps (MG) and interfacial adhesive defects (IAD). There were no significant differences between composite types in 44 out of 48 (MG) or 43/48 (IAD) comparisons. More MG were observed with X than with OFL (14 out of 16 comparisons, two significant), while in 16 of 16 comparisons with X more IAD were observed (14 significant). After artificial ageing, MG generally increased (9/16 significant), compared to IAD (one significant). The performance of the investigated composite types concerning the integrity of the tooth-composites interface was comparable. Compared to the 1-step self-etch system, the bond with the 3-step etch-and-rinse adhesive was raised.

     

Molecular and cellular events of dopamine D1 receptor‐mediated tau phosphorylation in SK‐N‐MC cells

Microtubules are involved in the formation of axons and dendrites, maintenance of neuronal morphology, and cellular trafficking. Recent studies suggest that drugs affecting dopamine activity in the brain can induce cytoskeletal modifications. For instance, we have demonstrated in acute rat brain slices a molecular chain of events connecting dopamine D1 receptor to aberrant phosphorylation of the microtubule‐associated protein tau. However, the molecular and cellular effects of tau phosphorylated by means of the activation of dopamine receptors were unexplored. Here we used SK‐N‐MC cells, which express endogenously functional D1 receptors, to demonstrate that levels of phosphorylated tau at serines 199–202 or 214 are increased by a calcium‐dependent pathway subsequent to D1 receptor stimulation. Using selective pharmacological tools, we showed that enhanced intracellular calcium lead to cyclin‐dependent kinase 5 (cdk5) activation, by calpain proteolysis of p35 to p25, as well as glycogen synthase kinase 3β (GSK3β) activation, by its phosphorylation at tyrosine 216. Interestingly, while the activation of protein kinase A (PKA) led directly to the phosphorylation of tau at serine 214, tau phosphorylation at serines 199–202 was independent of PKA. In addition, inhibition of cdk5 or GSK3β prevented the decrease in cell viability induced by D1 receptor stimulation whereas PKA inhibition had no influence. Our data demonstrate that activation of cdk5 and GSK3β following D1 receptor stimulation could have profound influence on both the neuronal cytoskeletal constituent tau and cell survival in SK‐N‐MC cells. Synapse 65:69–76, 2011. © 2010 Wiley‐Liss, Inc.     

Diagnosis and Management of Dural Sinus Thrombosis following Resection of Cerebellopontine Angle Tumors

Objective Lateral sinus thrombosis is a potentially devastating but seldom studied complication of cerebellopontine angle (CPA) tumor surgery. Systemic anticoagulation in the early postoperative period has often been avoided due to the potential risks of intracranial hemorrhage. Design Retrospective review. Setting Tertiary referral center. Main Outcome Measures The goal of this study was to identify the frequency, treatment, and outcomes in patients who develop postoperative venous sinus thrombosis following CPA tumor surgery and receive early systemic anticoagulation. Results Of 43 patients with CPA tumors, we report five patients (11.6%) with transverse and/or sigmoid sinus thrombosis following resection of the tumor, four of which were detected on routine early postoperative noncontrast computed tomography (CT) scan. The thrombosis was confirmed in all cases with CT venography or magnetic resonance venography. Affected patients had significantly larger tumors than controls and tended to undergo longer operations. These patients were treated with immediate anticoagulation (intravenous heparin, followed by Coumadin for 6 months) without complication. Conclusion Venous sinus thrombosis is an underrecognized complication of CPA surgery, but it can be diagnosed in the early postoperative period by noncontrast CT imaging. Early postoperative initiation of systemic anticoagulation appears safe and effective to prevent the progression of thrombosis and its consequences.     

Effects of Sauna Alone and Postexercise Sauna Baths on Blood Pressure and Hemodynamic Variables in Patients With Untreated Hypertension

J Clin Hypertens (Greenwich). 2012;00:00–00 ©2012 Wiley Periodicals, Inc. The effects of sauna alone vs exercise and sauna on ambulatory blood pressure monitoring and central hemodynamic variables were measured in 16 patients with untreated hypertension assigned to a control period, sauna, or exercise and sauna. Exercise and sauna had positive effects on 24‐hour systolic and mean blood pressure in patients with untreated hypertension. Exercise and sauna and sauna alone reduce total vascular resistance, with positive effects lasting up to 120 minutes after heat exposure.