OBJECTIVE To investigate the effect of pulsed radiofrequency (PRF) applied proximal to the injured peripheral nerve on the expression of tumor necrosis factor-α (TNF-α) in a neuropathic pain rat model. METHODS Nineteen male Sprague-Dawley rats were used in the study. All rats underwent chronic constriction injury (CCI) procedure. After 7 days of CCI, withdrawal frequency of affected hind paw ...

The -1 programmed ribosomal frameshifts (PRF), which are used by many viruses, occur at a heptanucleotide slippery sequence and are currently thought to involve the tRNAs interacting with the ribosomal P- and A-site codons. We investigated here whether the tRNA occupying the ribosomal E site that precedes a slippery site influences -1 PRF. Using the human immunodeficiency virus type 1 (HIV-1) f...

The logistic person response function (PRF) models the probability of a correct response as a function of the item locations. Reise (2000) proposed to use the slope parameter of the logistic PRF as a person-fit measure. He reformulated the logistic PRF model as a multilevel logistic regression model and estimated the PRF parameters from this multilevel framework. An advantage of the multilevel ...

A goal of computational models is not only to explain experimental data but also to make new predictions. A current focus of computational neuroimaging is to predict features of the presented stimulus from measured brain signals. These computational neuroimaging approaches may be agnostic about the underlying neural processes or may be biologically inspired. Here, we use the biologically inspir...

HYPOTHESIS The complication and success rates in patients treated with either percutaneous cryosurgery (PCS) or percutaneous radiofrequency (PRF) for unresectable hepatic malignancies are similar. DESIGN Retrospective study. SETTING University hospital. PATIENTS AND METHODS Sixty-four patients were treated with either PCS (n = 31) or PRF (n = 33). Patient treatment was based on the random...

BACKGROUND AND OBJECTIVES Autologous platelet-rich fibrin (PRF(®)) is prepared by the automatic Vivostat(®) system. Conflicting results with Vivostat PRF in acute wound healing prompted us to examine its cellular and biomolecular composition. Specifically, platelets, selected growth factors and matrix metalloproteinase (MMP)-9 were quantified using novel analytical methods. MATERIALS AND METH...

INTRODUCTION The aim of this study was the comparision of postoperative outcomes in impacted mandibular third molars that were treated using either platelet-rich fibrin (PRF), a combination of PRF and piezosurgery, or conventional rotatory osteotomy. PATIENT AND METHODS The study included 20 patients; 40 extractions of impacted mandibular third molars were performed. Patients were divided int...

Platelet-rich fibrin (PRF) belongs to a new generation of platelet concentrates, with simplified processing and without biochemical blood handling. In this third article, we investigate the immune features of this biomaterial. During PRF processing, leucocytes could also secrete cytokines in reaction to the hemostatic and inflammatory phenomena artificially induced in the centrifuged tube. We t...

PURPOSE To investigate the effect of platelet rich fibrin (PRF) and beta tricalcium phosphate (β-TCP), alone or in combination, on bone regeneration in pig tibial defects. METHODS Four standardized defects were prepared in both tibias of three adult male pigs. The first defect was left unfilled as a control; the others were grafted with either PRF, β-TCP or PRF mixed with β-TCP. All animals w...

Several important viruses including the human immunodeficiency virus type 1 (HIV-1) and the SARS-associated Coronavirus (SARS-CoV) employ programmed -1 ribosomal frameshifting (PRF) for their protein expression. Here, a kinetic framework is developed to describe -1 PRF. The model reveals three kinetic pathways to -1 PRF that yield two possible frameshift products: those incorporating zero frame...