Injectable Glass Polyalkenoate Cements: Evaluation of their Rheological and Mechanical Properties with and Without the Incorporation of Lidocaine Hydrochloride

Lidocaine hydrochloride is used as an anesthetic in many clinical applications. This short communication investigates the effect of complete substitution of lidocaine hydrochloride for deionized (DI) water on the physico-chemical properties of two novel glass polyalkenoate cements. Substituting DI water with lidocaine hydrochloride resulted in cements with shorter working times but comparable setting times and mechanical properties. Fourier transform infrared spectroscopy confirmed that the setting reaction in cements containing DI water and lidocaine hydrochloride was completed within 24 h, post cement preparation and maturation. Further, it was explained that lidocaine hydrochloride binds to poly(acrylic) acid (PAA) due to electrostatic forces between the positively charged amino group of lidocaine hydrochloride and the carboxylic group of the PAA, resulting in a compact poly-complex precipitate

Does ligament balancing technique affect kinematics in rotating platform, PCL retaining knee arthroplasties?: A prospective randomized study

The goal of this prospective, randomized, blinded trial was to determine if ligament balancing techniques for rotating platform TKA affect postoperative knee kinematics. Sixteen patients with unilateral rotating platform TKA consented to participate in this institutional review board approved study. Eight patients were randomly selected to receive ligament balancing with an instrumented joint spreader device and eight patients received ligament balancing using fixed thickness spacer blocks. A single plane shape matching technique was used for kinematic analysis of static deep knee flexion and dynamic stair activities. There were no differences in knee kinematics between groups during static deep flexion activities. The spreader group demonstrated kinematics more similar to the normal knee during the ascending phase of the dynamic stair activity. Knee kinematics in static knee flexion were unaffected by ligament balancing technique, while knees balanced with the spreader demonstrated a medial pivot motion pattern during stair ascent. This medial pivot motion pattern may improve long-term results by more closely replicating normal knee kinematics

Adenovirus Gene Transfer to Amelogenesis Imperfecta Ameloblast-Like Cells

To explore gene therapy strategies for amelogenesis imperfecta (AI), a human ameloblast-like cell population was established from third molars of an AI-affected patient. These cells were characterized by expression of cytokeratin 14, major enamel proteins and alkaline phosphatase staining. Suboptimal transduction of the ameloblast-like cells by an adenovirus type 5 (Ad5) vector was consistent with lower levels of the coxsackie-and-adenovirus receptor (CAR) on those cells relative to CAR-positive A549 cells. To overcome CAR -deficiency, we evaluated capsid-modified Ad5 vectors with various genetic capsid modifications including “pK7” and/or “RGD” motif-containing short peptides incorporated in the capsid protein fiber as well as fiber chimera with the Ad serotype 3 (Ad3) fiber “knob” domain. All fiber modifications provided an augmented transduction of AI-ameloblasts, revealed following vector dose normalization in A549 cells with a superior effect (up to 404-fold) of pK7/RGD double modification. This robust infectivity enhancement occurred through vector binding to both αvβ3/αvβ5 integrins and heparan sulfate proteoglycans (HSPGs) highly expressed by AI-ameloblasts as revealed by gene transfer blocking experiments. This work thus not only pioneers establishment of human AI ameloblast-like cell population as a model for in vitro studies but also reveals an optimal infectivity-enhancement strategy for a potential Ad5 vector-mediated gene therapy for AI

Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

Angelų ikonografija Lietuvos bažnytinėje dailėje (XVI-XVIII a.) : daktaro disertacija : humanitariniai mokslai, menotyra (03 H)

Disertacija rengta 2006-2010 metais Vytauto Didžiojo universiteteBibliogr.: p. 130-144Menų fakultetasVytauto Didžiojo universiteta

Biofilms in Dental Unit Waterlines: Ultrastructural and Cytochemical Analysis

Dental unit waterlines are heavily colonized by bacteria which contaminate the water used to perform intra-oral, and sometimes invasive, procedures. There is little information on the nature of the biofilm colonizing the flexible plastic tubing used to supply water to the different handpieces. We have therefore undertaken quantitative microbial analysis and ultrastructural studies of these biofilms by direct counting with the epifluorescent filter technique and by transmission and scanning electron microscopy after staining with ruthenium red and periodic acid-thiosemicarbazide-silver proteinate to visualize the composition and the distribution of exopolysaccharides and intracellular polysaccharides. The biofilm was revealed as a non-uniform structure characterized by an uneven cell distribution in an extracellular matrix. The microbial community of the biofilm was composed of metabolically active Gram-negative, short rod and coccoid bacteria that formed microcolonies embedded in a multilayer exopolysaccharides envelope. Our results indicate that even though the biomass of dental unit waterlines biofilms increases with time there is no direct correlation with the concentration of free floating bacteria in the water. It can be concluded that the biofilm structure described herein is responsible for the high level of bacteria in some medical devices. The consequences are of clinical significance as it is known that this extracellular material limits the action of biocides and host defense

Quantitative Evaluation of the Adhesion of Bioactive Glasses Onto Ti6Al4V Substrates

This paper presents a new method for applying a uniform thickness bioactive glass coating to a Ti6Al4V substrate and postulates a fracture mechanics testing methodology to quantify the glass/metal adhesion in terms of a measured critical strain energy release rate (GIC). Bi-layer double cantilever beam (DCB) test specimens were developed for this purpose and were found to generate repeatable and consistent measures of GIC for the tested system. The measured GIC of the coating decreased significantly from 6.2 to 2.5 J/m2 with an increase in coating thickness from 90 to 390 μm. Since high temperature enamelling processes can potentially introduce significant residual stresses in the glass/metal system, the residual stresses were measured and their impact on the adhesion was assessed. Increases in the coating thickness were found to increase the residual stresses from 6.8 to 17.9 MPa, thus decreasing the adhesion between the glass and the Ti alloy. Finally, the directional stability of the crack within the coating was quantified by calculating the T-stress for coatings with different thicknesses and it was found that as the coating thickness increased, the crack destabilized and tended to kink rather than travel in a straight line