Publications by authors named "Varga P"

Background: The Spinal Instability Neoplastic Score (SINS) categorizes tumor related spinal instability. It has the potential to streamline the referral of patients with established or potential spinal instability to a spine surgeon. This study aims to define the inter- and intra-observer reliability and validity of SINS among radiation oncologists.

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Osteonecrosis of the jaw, in association with bisphosphonates (BRONJ) used for treating osteoporosis or cancer, is a severe and most often irreversible side effect whose underlying pathophysiological mechanisms remain largely unknown. Osteocytes are involved in bone remodeling and mineralization where they orchestrate the delicate equilibrium between osteoclast and osteoblast activity and through the active process called osteocytic osteolysis. Here, we hypothesized that (i) changes of the mineralized tissue matrix play a substantial role in the pathogenesis of BRONJ, and (ii) the osteocyte lacunar morphology is altered in BRONJ.

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A liquid droplet sitting on top of a pillar is crucially important for semiconductor nanowire growth via a vapor-liquid-solid (VLS) mechanism. For the growth of long and straight nanowires, it has been assumed so far that the droplet is pinned to the nanowire top and any instability in the droplet position leads to nanowire kinking. Here, using real-time in situ scanning electron microscopy during germanium nanowire growth, we show that the increase or decrease in the droplet wetting angle and subsequent droplet unpinning from the growth interface may also result in the growth of straight nanowires.

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Bone fragility due to osteopenia, osteoporosis or debilitating focal skeletal dysplasias is a frequent observation in the Mendelian disease Neurofibromatosis type 1 (NF1). To determine the mechanisms underlying bone fragility in NF1 we analyzed two conditional mouse models, Nf1Prx1 (limb knock-out) and Nf1Col1 (osteoblast specific knock-out), as well as cortical bone samples from individuals with NF1. We examined mouse bone tissue with micro-computed tomography, qualitative and quantitative histology, mechanical tensile analysis, small-angle X-ray scattering (SAXS), energy dispersive X-ray spectroscopy (EDX), and scanning acoustic microscopy (SAM).

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The key parameters influencing the elastic properties of the mineralized turkey leg tendon (MTLT) were investigated. Two structurally different tissue types appearing in the MTLT were considered: circumferential and interstitial tissue. These differ in their amount of micropores and their average diameter of the mineralized collagen fibril bundles.

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Study Type Retrospective cohort. Introduction The treatment of rare neoplastic conditions is challenging, especially because studies providing high levels of evidence are often lacking. Such is the case with primary tumors of the spine (PTS), which have a low incidence, are pathologically heterogeneous, and have diverse treatment approaches.

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Finite element (FE) analysis has been applied for the past 40 years to simulate the mechanical behavior of bone. Although several validation studies have been performed on specific anatomical sites and load cases, this study aims to review the predictability of human bone strength at the three major osteoporotic fracture sites quantified in recently completed in vitro studies at our former institute. Specifically, the performance of FE analysis based on clinical computer tomography (QCT) is compared with the ones of the current densitometric standards, bone mineral content, bone mineral density (BMD) and areal BMD (aBMD).

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Introduction: It has been shown previously that a history of low back pain often begins in childhood or adulthood. Indeed, the prevalence of severe back symptoms among schoolchildren is not insignificant. Possibilities for the primary prevention of intervertebral disc degeneration-related conditions are poorly reported in the literature despite the assumed socio-economical impact of the prevention of these conditions.

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Background: The spontaneous osteoporotic fracture of the sacrum, known as a sacral insufficiency fracture (SIF) was first described as an unrecognized syndrome of the elderly by Laurie, in 1982. Numerous case histories and a few series of cases have been discussed in medical journals; however, none have been reported in Hungary.

Goal: To delineate the leading diagnostic steps in the recognition of SIF and review the therapeutic guidelines.

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The phenotype, or observable trait of interest, is at the core of studies identifying associated genetic variants and their functional pathways, as well as diagnostics. Yet, despite remarkable technological developments in genotyping and progress in genetic research, relatively little attention has been paid to the equally important issue of phenotype. This is especially true for disc degeneration-related disorders, and the concept of degenerative disc disease, in particular, where there is little consensus or uniformity of definition.

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We investigate the three-dimensional (3-D) organization of mineralized collagen fibrils in human cortical bone based on synchrotron X-ray phase nano-tomography images. In lamellar bone the collagen fibrils are assumed to have a plywood-like arrangement, but due to experimental limitations the 3-D fibril structure has only been deduced from section surfaces so far and the findings have been controversial. Breakthroughs in synchrotron tomographic imaging have given access to direct 3-D information on the bone structure at the nanoscale level.

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The tailoring of electromagnetic near-field properties is the central task in the field of nanophotonics. In addition to 2D optics for optical nanocircuits, confined and enhanced electric fields are utilized in detection and sensing, photovoltaics, spatially localized spectroscopy (nanoimaging), as well as in nanolithography and nanomanipulation. For practical purposes, it is necessary to develop easy-to-use methods for controlling the electromagnetic near-field distribution.

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Introduction: Extracorporeal stool transport (recycling of chyme discharged from the proximal stoma end to the distal end of a high jejunostomy or ileostomy) is thought to be beneficial in preventing malabsoprtion, sodium loss, cholestasis and atrophy of the distal intestine until restoration of the intestinal continuity becomes possible. However little is known about its adverse effects. Our aim was to investigate the microbiological safety of recycling.

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The scaphoid is the most frequently fractured carpal bone. When investigating fixation stability, which may influence healing, knowledge of forces and moments acting on the scaphoid is essential. The aim of this study was to evaluate cartilage contact forces acting on the intact scaphoid in various functional wrist positions using finite element modeling.

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Purpose: Patient-reported outcome measurements (PROMs) are widely used in spine care. The development of reliable and valid National versions of spine-related disability questionnaires is strongly recommended from both the clinical and scientific points-of-view. The aims of this study were to adapt and validate the Oswestry Disability Index (ODI) and the Quebec back pain disability scale (QDS) for use with the Hungarian language.

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Colloidal gold nanoparticles represent technological building blocks which are easy to fabricate while keeping full control of their shape and dimensions. Here, we report on a simple two-step maskless process to assemble gold nanoparticles from a water colloidal solution at specific sites of a silicon surface. First, the silicon substrate covered by native oxide is exposed to a charged particle beam (ions or electrons) and then immersed in a HF-modified solution of colloidal nanoparticles.

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Classical antipsychotics, e.g. haloperidol, chlorpromazine, are potent at controlling the positive symptoms of schizophrenia but frequently elicit extrapyramidal motor side-effects.

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Objective: Contrast between not fully mineralized tissues is weak and limits conventional computed tomography (CT). An automated grayscale histogram-based analysis features could improve the sensitivity to tissue alterations during early bone healing.

Materials And Methods: Tissue formation in a rat osteotomy model was analyzed using in vivo micro-CT and classified histologically (mineralized, cartilage, and connective tissues).

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Background: Aging and degeneration of human intervertebral disc (IVD) are associated with biochemical changes, including racemization and glycation. These changes can only be counteracted by protein turnover. Little is known about the longevity of IVD elastin in health or disease.

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Aims: Primary spinal tumors are rare diseases and there are less objective data in the international literature. We analyzed the epidemiology and clinical consequences of primary spinal tumors based on the clinical experience of the National Center for Spinal Disorders.

Methods: Demographic and clinical data of 300 patients treated in our institute between 1995 and 2007 was collected retrospectively and analysed.

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The O adsorption on Rh(100) has been studied using high resolution core level spectroscopy, low energy electron diffraction and scanning tunnelling microscopy. In addition to the well known (2 × 2), (2 × 2)-pg and c(8 × 2) structures at coverages of 0.25, 0.

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Article Synopsis
  • * Out of 50 chordomas analyzed, a significant majority showed expression of IGF-1R (76%), IGF-1 (92%), and to a lesser extent IGF-2 (50%), indicating that these proteins play an important role in these tumors.
  • * The findings suggest that patients with high IGF-1R expression might be ideal candidates for targeted therapies, especially if they have large chordomas that cannot be surgically removed.
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Article Synopsis
  • This study is a retrospective analysis aimed at exploring the expression of ezrin, MMP-9, and COX-2 in chordomas, which are a type of tumor.
  • Researchers tested samples from 50 chordomas, looking for potential therapeutic targets that could improve clinical outcomes.
  • The findings suggest that ezrin, MMP-9, and COX-2 are commonly expressed in these tumors, and factors such as age, location, and tumor volume significantly affect patient survival, indicating a need for new treatment strategies.
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