63 research outputs found

    Stent-in-Stent Endovascular Correction in Right Internal Carotid Artery Restenosis: a Clinical Case

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    Background. Carotid artery restenosis is a rare complication of carotid stenting. The Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) reveals an in-stent restenosis rate of 0–6 %, a fairly low value given an extensive study sampling of patients. Restenosis still lacks an adequate explanation in endovascular carotid surgery. Intravascular ultrasound visualisation, drug-coated balloons, stent reimplantation or reconstructive surgery have actively been used since relatively recently to tackle restenosis. Drug-coated balloons may fail in certain cases due to hampered restenosis angioplasty in a markedly rigid neointimal hyperplasia. Surgical reconstruction also possessed drawbacks, mostly due to obstacles in the stent removal and the procedure infeasibility in high-risk surgical patients.Materials and methods. The article describes a clinical case of stent-in-stent restenosis correction with drug-coated balloon-expandable re-stenting of right internal carotid artery and a long-term prognosis estimation with optical coherence tomography.Results and discussions. This tactic was adopted due to haemodynamically and clinically significant internal carotid artery restenosis, the patient’s denial of carotid endarterectomy and insufficiently effective balloon angioplasty. The choice of the correction technique was conclusive basing on a negative stent deformation testing that showed the lack of deforming stress factors at internal carotid artery restenosis. Intravascular imaging greatly enhances our ability to understand and assess endovascular processes.Conclusion. We consider clinically significant restenoses in previously stented carotid arteries as requiring further research effort, with the clinical case presented describing an individual solution

    Case of applying allogenic mesenchymal stem cells of adipogenic origin in veterinary dentistry

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    © Medwell Journals, 2015. After drawing a permanent tooth (canine tooth) in a dog because of complicated caries, an oroantral fistula was formed in the upper jaw right. Multiple surgeries gave no results and there was a relapse of fistulous tract along the mucogingival junction in the upper jaw right. We performed an operation for guided tissue regeneration in the area of oroantral fistula with simultaneous plastics of soft tissue. We used osteoinductive material was used as allogeneic mesenchymal stem cells in combination with nickelide titanium granules (nitigran). Adipogenic stem cells were isolated from subcutaneous adipose tissue of an adult female dog. The difficulty in using a suspension of mesenchymal stem cells in vivo lies in its spreading into the surrounding tissue in the absence of any carrier material. The three-dimensional porous-permeable nickelide titanium incubators that we use have unique features such as porous-permeable structure with widely open pores, excellent wettability with body fluids, a high biological, biochemical and biomechanical compatibility at the cellular level. We prepared the cellular therapeutic preparation immediately prior to transplantation. We used nickelide titanium granules as a matrix for the local retention of cells. The result of the conducted surgery was a complete closure of oroantral fistula in a dog

    Comparative Analysis of Bacterial Communities Associated with Healthy and Inflamed Peri-implant Tissues

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    © 2016, Springer Science+Business Media New York.Dental implants are used to restore dentition defects. However, despite the high efficiency of the method of placing dental implants, their integration can be accompanied by peri-implant diseases (peri-implant mucositis and peri-implantitis), which are inflammatory reactions induced by the bacterial activity. In the present pilot study, we described and compared the bacterial communities associated with healthy and inflamed peri-implant mucosal tissues using 16S rRNA gene amplicon pyrosequencing approach. It was revealed that various representatives of the phyla Firmicutes, Bacteroidetes, Fusobacteria, and Proteobacteria were found at significant levels in healthy and peri-implant mucositis sites but in different proportions. Furthermore, it was shown that the genus Fusobacterium was the only group present in higher proportions on inflamed tissues than on healthy tissues surrounding dental implants of all patients. In addition, unclassified Methylobacteriaceae and the genus Veillonella as well as some other phylotypes were present at higher levels in peri-implant mucositis sites of some patients. This study indicates that several microbial agents may play important roles during the development of oral peri-implant diseases

    Observation of the radiative decay mode of the free neutron

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    The theory of quantum electrodynamics (QED) predicts that beta decay of the neutron into a proton, electron and antineutrino should be accompanied by a continuous spectrum of soft photons. While this inner bremsstrahlung branch has been previously measured in nuclear beta and electron capture decay, it has never been observed in free neutron decay. Recently, the photon energy spectrum and branching ratio for neutron radiative decay have been calculated using two approaches: a standard QED framework(1-3) and heavy baryon chiral perturbation theory(4) (an effective theory of hadrons based on the symmetries of quantum chromodynamics). The QED calculation treats the nucleons as point-like, whereas the latter approach includes the effect of nucleon structure in a systematic way. Here we observe the radiative decay mode of free neutrons, measuring photons in coincidence with both the emitted electron and proton. We determined a branching ratio of (3.13 +/- 0.34) x 10(-3) (68 per cent level of confidence) in the energy region between 15 and 340 keV, where the uncertainty is dominated by systematic effects. The value is consistent with the predictions of both theoretical approaches; the characteristic energy spectrum of the radiated photons, which differs from the uncorrelated background spectrum, is also consistent with the calculated spectrum. This result may provide opportunities for more detailed investigations of the weak interaction processes involved in neutron beta decay.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62639/1/nature05390.pd

    A candidate ion-retaining state in the inward-facing conformation of sodium/galactose symporter: Clues from atomistic simulations

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    The recent Vibrio parahaemolyticus sodium/galactose (vSGLT) symporter crystal structure captures the protein in an inward-facing substrate-bound conformation, with the sodium ion placed, by structural alignment, in a site equivalent to the Na2 site of the leucine transporter (LeuT). A recent study, based on molecular dynamics simulations, showed that the sodium ion spontaneously leaves its initial position diffusing outside vSGLT, toward the intracellular space. This suggested that the crystal structure corresponds to an ion-releasing state of the transporter. Here, using metadynamics, we identified a more stable Na+ binding site corresponding to a putative ion-retaining state of the transporter. In addition, our simulations, consistently with mutagenesis studies, highlight the importance of D189 that, without being one of the NA(+)-coordinating residues, regulates its binding/release

    Insights into the Binding of Phenyltiocarbamide (PTC) Agonist to Its Target Human TAS2R38 Bitter Receptor

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    Humans' bitter taste perception is mediated by the hTAS2R subfamily of the G protein-coupled membrane receptors (GPCRs). Structural information on these receptors is currently limited. Here we identify residues involved in the binding of phenylthiocarbamide (PTC) and in receptor activation in one of the most widely studied hTAS2Rs (hTAS2R38) by means of structural bioinformatics and molecular docking. The predictions are validated by site-directed mutagenesis experiments that involve specific residues located in the putative binding site and trans-membrane (TM) helices 6 and 7 putatively involved in receptor activation. Based on our measurements, we suggest that (i) residue N103 participates actively in PTC binding, in line with previous computational studies. (ii) W99, M100 and S259 contribute to define the size and shape of the binding cavity. (iii) W99 and M100, along with F255 and V296, play a key role for receptor activation, providing insights on bitter taste receptor activation not emerging from the previously reported computational models

    Russian consensus statement on the diagnosis and treatment of patients with carotid stenosis

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    Carotid stenosis is a multidisciplinary problem that requires the involvement of a specialists’ team, including cardiovascular surgeons, neurosurgeons, endovascular surgeons, cardiologists, neurologists, and internists. In this consensus statement, a group of experts considered the main stages of diagnosing carotid stenosis, as well as discussed, the necessary prevention methods and features of choosing the optimal treatment approach. The aim was to provide concise and structured information on the management of patients with carotid stenosis. This document was developed based on the updated clinical guidelines of the European Society for Vascular Surgery and the American Association for Vascular Surgery, taking into account the consensus opinion of Russian experts

    The Morphological Description Automation of the Optic Nerve Head Boundary in Digital Fundus Images

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    Purpose. To develop the automating method for the description of the optic nerve head condition. The method allows to differentiate the optic nerve head with clear boundaries typical for the normal fundus and optic nerve head with blurred boundaries typical for different types of ophthalmopathology. Methods. The proposed method is based on integration algorithm of luminance samples along the diagonal. It shows that optic nerve head images with blurred boundaries are characterized by a more linear increase in brightness in the frontal region compared to the accumulation result for the case of normal optic nerve head. To identify this feature the firstorder derivative can be used. To reduce the effect of blood vessels on the result of processing luminance samples along the diagonal is performed in the red channel since the blood vessels effect on the optic nerve head border is minimized in the red color component. Results. The application of this method to images of optic nerve head with diffuse boundaries shows that the accumulation result is characterized by a slower brightness variation. Тhe analysis of 20 fundus images revealed that the value of the first-order derivative of the result of accumulation of luminance readings diagonally for images of optic nerve head with blurred boundaries is 2 times smaller than for images of optic nerve head with clear boundaries. Conclusions. Тhe presented method can be used to create expert systems which allow to automate the process of morphological description of the optic nerve head border from the fundus images and also can partially solve the diagnostic problem. Since the disappearance of the clarity of the optic nerve head borders and the appearance of their blurring are the main diagnostic criterions for various types of pathology this method can be used to create medical expert systems and software for the fundus images processing

    The Automated Expert Support System for Optic Nerve Head Morphological Description

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    Purpose. To develop the automated expert support system for optic nerve head morphological description in normal conditions and in pathology.Methods. The proposed expert support system is based on the integration algorithm of luminance samples along the diagonal, it allows to detect the optic nerve head border. On the basis of this algorithm the method for solving the following tasks of fundus image processing have been proposed: detecting of the optic nerve head border, method of the morphological description of the optic nerve head boundary, method of the determining the value of the disk excavation. An experimental study of the parameters effect on the effectiveness of the optic nerve head detecting method was made.Results. The effectiveness assessment of the proposed border detection algorithm on the optic nerve head model has showed that the amount of overlap averaged 0.985, which indicates high quality. It was found that the algorithm for estimating the diameter of the single-sided optic nerve head image is sufficiently resistant to changes in such parameters as the influence of the noise level in the scene and the offset of the strobe center coordinates of the samples accumulation from the image center coordinates. Evaluation of the efficiency of the optic nerve head borders morphological description has showed that the value of the first-order derivative of the result of accumulation of luminance readings diagonally for images of optic nerve head with blurred boundaries is 2 times smaller than for images of optic nerve head with clear boundaries. The effectiveness of the method of selecting the border for assessment the disk excavation size was examined. It was obtained that the error in estimating the magnitude of excavation amounted to an average of 8.43 %.Conclusions. Тhe presented expert support system allows to automate the process of optic disk morphological description, in particular, such parameters as the state of the border and the size of the disc excavation. This method can be used to create medical expert systems and software for fundus images processing
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