89 research outputs found
Effect of iloprost on contractile impairment and mitochondrial degeneration in ischemia-reperfusion of skeletal muscle
Purpose Acute lower extremity ischemia is still a main cause of mortality and morbidity in orthopedic traumatology and reconstructive surgery. In acute lower extremity ischemia, the skeletal muscles are the tissues that are the most vulnerable to ischemia. The aim of this study was to evaluate the effects of iloprost (IL) therapy on skeletal muscle contractile impairment and mitochondrial degeneration in an acute lower extremity ischemia-reperfusion rat model. Main Methods Forty Wistar albino rats were randomly divided into a control group and four experimental groups. Experimental groups were either subjected to 2Â h of lower extremity ischemia followed by a 4-h reperfusion period or to 4Â h of ischemia followed by an 8-h reperfusion period. Except for the animals in the control group, all animals received IL (1Â ng/kg/min) or saline (1Â ml/kg) by intraperitoneal infusion for 10Â min immediately before reperfusion. At the end of the recording of skeletal muscle electrical activity and contractility, all rats were sacrificed by decapitation and muscle samples of lower extremity were immediately harvested for histopathologic analyses. Results After ischemia-reperfusion, a breakdown in the forceâfrequency curves of extensor digitorum longus muscle was observed, showing the diminished muscle contractility. However, IL significantly improved muscle contractility following injury induced by 2Â h of ischemia followed by a 4-h reperfusion period. In addition, IL partially ameliorated mitochondrial degeneration in the muscle cells of ischemia groups. Conclusion This study indicates that immediate IL therapy repairs muscle damage especially after 2Â h of ischemia and 4Â h of reperfusion and therefore that IL improves contractile function
Managing hyperemesis gravidarum: a multimodal challenge
Up to 90% of pregnant women experience nausea and vomiting. When prolonged or severe, this is known as hyperemesis gravidarum (HG), which can, in individual cases, be life threatening. In this article the aetiology, diagnosis and treatment strategies will be presented based on a selective literature review. Treatment strategies range from outpatient dietary advice and antiemetic drugs to hospitalization and intravenous (IV) fluid replacement in persistent or severe cases. Alternative methods, such as acupuncture, are not yet evidence based but sometimes have a therapeutic effect
Fracture strengths of chairâsideâgenerated veneers cemented with glass fibers
Introduction: CAD/CAM (computerâaided design and computerâaided manufacturing) systems have refreshed the idea of chairâside production of restorations, but the fracture of ceramic veneers remains a problem. Cementation with glass fibers may improve the fracture strengths and affect the failure modes of CAD/CAMâgenerated ceramic veneers. Therefore, this study compared the fracture strengths of ceramic veneers produced at chair side and cemented with or without glass fibers with those of composite veneers. Methodology: Thirty intact mandibular incisors were randomly divided into three groups (n = 10) and treated with CAD/CAMâfabricated veneers cemented with dualâcure composite resin luting cement (CRLC; Group 1), CAD/CAMâfabricated veneers cemented with a glass fiber network (GFN) and dualâcure CRLC (Group 2), and a direct particulate filler composite veneer constructed utilizing fiber and a restorative composite resin (Group 3). The specimens were tested with a universal testing machine after thermal cycling treatment. Result: The loads at the start of fracture were the lowest for traditionally fabricated composite veneers and higher for CAD/CAMâgenerated. Veneers cemented either without or with the GFN. The failure initiation loads (N) for the veneers were 798.92 for Group 1, 836.27 for Group 2, and 585.93 for Group 3. The predominant failure mode is adhesive failure between the laminates and teeth for Group 1, cohesive failure in the luting layer for Group 2, and cohesive laminate failure for Group 3, which showed chipping and small fractures. Conclusion: Ceramic material is a reliable alternative for veneer construction at chair side. Fibers at the cementation interface may improve the clinical longevity and provide higher fracture strength values.Key words: Computer-aided design and computer-aided manufacturing, cementation, fracture strength, glass fiber, laminate venee
Microhardness of dual-polymerized resin cement around a translucent fiber post in the intraradicular environment
AIM: In this study, we evaluated the effect of photopolymerization on Vickers microhardness of dual-polymerized resin cement at three locations when a translucent quartz fiber post was used. MATERIALS AND METHODS: Single-rooted bovine teeth received quartz fiber post systems (length: 12 mm) using a dual-polymerized resin cement. In Group 1, the posts were cemented but not photopolymerized, and in Group 2, the posts were both cemented and photopolymerized. After cementation, approximately 1.5-mm thick sections were obtained (two cervical, two middle, and two apical) for regional microhardness evaluations. STATISTICAL ANALYSIS: Statistical analyses were performed using the SPSS software (ver. 11.0 for Windows; SPSS, Inc., Chicago, IL, USA). Microhardness (kg/mm(2)) data were submitted to two-way analysis of variance (two-way ANOVA) and repeated measures with microhardness values as the dependent variable and polymerization status (two levels: with and without) and root region (three levels: cervical, middle, and apical) as independent variables. Multiple comparisons were made using Dunnett's T3 post-hoc test. P values of <0.05 were considered to indicate statistical significance in all tests. RESULTS: Photopolymerization did not significantly change the microhardness values when compared with no photopolymerization. Microhardness values also showed no significant difference between the three regions in the root canals in both groups. CONCLUSIONS: The mode of polymerization of the cement tested in combination with the translucent quartz fiber post system did not affect the microhardness of the cement at the cervical, middle, or apical regions of the root
Comparative effect of different polymerization techniques on residual monomer and hardness properties of PMMA-based denture resins
Purpose: The aim of this study was to compare the residual monomer and microhardness of poly(methyl methacrylate) (PMMA)âbased denture resins processed by using autoclave and conventional water bath techniques. Methods: To determine the amount of residual methyl methacrylate (MMA) monomer, disk-shaped specimens (n=5) were prepared from 3 different acrylic resins (Meliodent, Paladent and Qc-20). Control groups were polymerized in water bath for 30 minutes at 100°C. The study groups were prepared in an autoclave device for 60°C/30 min followed 130°C/10 min and the other group for 60°C/30 min followed by 130°C/20 min. According to standard calibration curves, ultraviolet spectrophotometry at 230 nm was used to determine the residual monomer. For the Vickers hardness measurements, disk-shaped specimens (n=5) were prepared for each test group. Hardness measurements were performed with a Vickers hardness tester under a 4.91-N press load for a 30 seconds, after immersion in distilled water at 37ÂșC for 48 hours. The data were analyzed by ANOVA and Tukey HSD test (p0.05). Conclusions: The autoclave polymerization technique exhibited significantly lower residual monomer content and greater hardness than conventional heat polymerization. © 2014 SocietĂ Italiana Biomateriali
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