720 research outputs found

    Mechanics and Mathematical Modeling of Class III Treatment with Orthodontic Appliances with a Movable Ramp

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    Treatment of class III is a current problem in orthodontics that requires constant improvement of its methods, development of new or modifications of known methods and techniques. We have developed and studied the modification of removable functionally-directing orthodontic appliances for treatment of Class III, which consists of a plastic base, vestibular arc, retaining clasps, ramp, which is connected with the base by means of two torsion springs. Its usage ensures a prolonged contact of ramp with the teeth. We studied two types of club-shaped springs (torsion springs): one spring, which create an amortization effect during the action of the ramp, but do not change its inclination angle and second one – spring that seek to increase the angle of the ramp inclination due to the disclosure of its curl

    Amino acid substitution equivalent to human chorea-acanthocytosis I2771R in yeast Vps13 protein affects its binding to phosphatidylinositol 3-phosphate

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    The rare human disorder chorea-acanthocytosis (ChAc) is caused by mutations in hVPS13A gene. The hVps13A protein interacts with actin and regulates the level of phosphatidylinositol 4-phosphate (PI4P) in the membranes of neuronal cells. Yeast Vps13 is involved in vacuolar protein transport and, like hVps13A, participates in PI4P metabolism. Vps13 proteins are conserved in eukaryotes, but their molecular function remains unknown. One of the mutations found in ChAc patients causes amino acids substitution I2771R which affects the localization of hVps13A in skeletal muscles. To dissect the mechanism of pathogenesis of I2771R, we created and analyzed a yeast strain carrying the equivalent mutation. Here we show that in yeast, substitution I2749R causes dysfunction of Vps13 protein in endocytosis and vacuolar transport, although the level of the protein is not affected, suggesting loss of function. We also show that Vps13, like hVps13A, influences actin cytoskeleton organization and binds actin in immunoprecipitation experiments. Vps13-I2749R binds actin, but does not function in the actin cytoskeleton organization. Moreover, we show that Vps13 binds phospholipids, especially phosphatidylinositol 3-phosphate (PI3P), via its SHR_BD and APT1 domains. Substitution I2749R attenuates this ability. Finally, the localization of Vps13-GFP is altered when cellular levels of PI3P are decreased indicating its trafficking within the endosomal membrane system. These results suggest that PI3P regulates the functioning of Vps13, both in protein trafficking and actin cytoskeleton organization. Attenuation of PI3P-binding ability in the mutant hVps13A protein may be one of the reasons for its mislocalization and disrupted function in cells of patients suffering from ChAc

    Phosphatidylinositol-3-phosphate regulates response of cells to proteotoxic stress

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    Human Nedd4 ubiquitin ligase, or its variants, inhibit yeast cell growth by disturbing the actin cytoskeleton organization and dynamics, and lead to an increase in levels of ubiquitinated proteins. In a screen for multicopy suppressors which rescue growth of yeast cells producing Nedd4 ligase with an inactive WW4 domain (Nedd4w4), we identified a fragment of ATG2 gene encoding part of the Atg2 core autophagy protein. Expression of the Atg2-C1 fragment (aa 1074-1447) improved growth, actin cytoskeleton organization, but did not significantly change the levels of ubiquitinated proteins in these cells. The GFP-Atg2-C1 protein in Nedd4w4-producing cells primarily localized to a single defined structure adjacent to the vacuole, surrounded by an actin filament ring, containing Hsp42 and Hsp104 chaperones. This localization was not affected in several atg deletion mutants, suggesting that it might be distinct from the phagophore assembly site (PAS). However, deletion of ATG18 encoding a phosphatidylinositol-3-phosphate (PI3P)-binding protein affected the morphology of the GFP-Atg2-C1 structure while deletion of ATG14 encoding a subunit of PI3 kinase suppressed toxicity of Nedd4w4 independently of GFP-Atg2-C1. Further analysis of the Atg2-C1 revealed that it contains an APT1 domain of previously uncharacterized function. Most importantly, we showed that this domain is able to bind phosphatidylinositol phosphates, especially PI3P, which is abundant in the PAS and endosomes. Together our results suggest that human Nedd4 ubiquitinates proteins in yeast and causes proteotoxic stress and, with some Atg proteins, leads to formation of a perivacuolar structure, which may be involved in sequestration, aggregation or degradation of proteins

    The origin of paramagnetic magnetization in field-cooled YBa2Cu3O7 films

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    Temperature dependences of the magnetic moment have been measured in YBa_2Cu_3O_{7-\delta} thin films over a wide magnetic field range (5 <= H <= 10^4 Oe). In these films a paramagnetic signal known as the paramagnetic Meissner effect has been observed. The experimental data in the films, which have strong pinning and high critical current densities (J_c ~ 2 \times 10^6 A/cm^2 at 77 K), are quantitatively shown to be highly consistent with the theoretical model proposed by Koshelev and Larkin [Phys. Rev. B 52, 13559 (1995)]. This finding indicates that the origin of the paramagnetic effect is ultimately associated with nucleation and inhomogeneous spatial redistribution of magnetic vortices in a sample which is cooled down in a magnetic field. It is also shown that the distribution of vortices is extremely sensitive to the interplay of film properties and the real experimental conditions of the measurements.Comment: RevTex, 8 figure

    Melatonin and its metabolites ameliorate UVR-induced mitochondrial oxidative stress in human MNT-1 melanoma cells

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    Melatonin (Mel) is the major biologically active molecule secreted by the pineal gland. Mel and its metabolites, 6-hydroxymelatonin (6(OH)Mel) and 5-methoxytryptamine (5-MT), possess a variety of functions, including the scavenging of free radicals and the induction of protective or reparative mechanisms in the cell. Their amphiphilic character allows them to cross cellular membranes and reach subcellular organelles, including the mitochondria. Herein, the action of Mel, 6(OH)Mel, and 5-MT in human MNT-1 melanoma cells against ultraviolet B (UVB) radiation was investigated. The dose of 50 mJ/cm2 caused a significant reduction of cell viability up to 48%, while investigated compounds counteracted this deleterious effect. UVB exposure increased catalase activity and led to a simultaneous Ca++ influx (16%), while tested compounds prevented these disturbances. Additional analysis focused on mitochondrial respiration performed in isolated mitochondria from the liver of BALB/cJ mice where Mel, 6(OH)Mel, and 5-MT significantly enhanced the oxidative phosphorylation at the dose of 10&#8722;6 M with lower effects seen at 10&#8722;9 or 10&#8722;4 M. In conclusion, Mel, 6(OH)Mel and 5-MT protect MNT-1 cells, which express melatonin receptors (MT1 and MT2) against UVB-induced oxidative stress and mitochondrial dysfunction, including the uncoupling of oxidative phosphorylation

    ALGORITHM FOR SPEECH DISORDERS CORRECTION USING PROPRIETARY CONSTRUCTION DEVICE

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    Currently, there is a tendency in Ukraine to increase the number of children with speech disorders. One of the most common disorders of speech function is dyslalia. Speech therapists are the main form of correctional training, children are assigned certain and consistent stages of speech therapy. Along with that, various individual and standard devices are used. The aim of the study – to conduct logopedic correction of speech disorders in patients with physiologic occlusion using the in-house designed device according to the proposed algorithm. Materials and Methods. A survey was conducted on 73 children (24 – aged 3 to 6 years, 49 – from 6 to 12 years old) without significant orthodontic pathology in the presence of speech impairment with normal hearing and intelligence and speech correction. In addition to logopedic exercises, it was recommended to use vestibular plates Dr. Hinz - MUPPY-P with beads, removable orthodontic devices with beads, Bluegrass appliances, devices for elimination and prevention of unhealthy tongue habits. In order to identify early risk factors for major dental diseases, the hygienic state of the cavity of the mouth, the intensity of caries, the presence or absence of inflammatory processes in the tissues of periodontal disease were determined. Results and Discussion. The first step in the algorithm for successful correction of speech disorders were to explain its necessity. The second stage involved the phonetic diagnosis of all aspects of speech, logic, intelligence, memory and thinking. Polymorphic dyslalia was diagnosed in all subjects of reporting panel. The third stage of the algorithm is to carry out work to overcome the abnormalities of the phonetic side of speech was a direct speech correction. The proposed device for elimination and prevention of unhealthy tongue habits was used in 6 cases. Conclusions. After the speech therapy correction correct articulation and sound were formed. The proposed device for the elimination and prevention unhealthy tongue habits should be used in conjunction with speech therapy, in particular, dyslalia. In addition to the positive logopedic effect of the proposed therapeutic and prophylactic measures, we have also received improvement of the hygienic state of the oral cavity, the absence of an increase in the intensity of the caries of permanent teeth and increased motivation in patients

    Healthcare practitioner views and experiences of patients self-monitoring blood pressure: vignette study

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    Background Home self-monitoring of blood pressure is widely used in primary care to assist in the diagnosis of hypertension, as well as to improve clinical outcomes and support adherence to medication. The National Institute for Health and Care Excellence (NICE) care pathways for hypertension recommend specific guidelines, although they lack detail on supporting patients to self-monitor. Aim To elicit primary care practitioners’ experiences of managing patients’ home blood pressure self-monitoring, across surgeries located in different socioeconomic areas. Design & setting A qualitative focus group study was conducted with a total of 21 primary care professionals. Method Participants were GPs and practice nurses (PNs), purposively recruited from surgeries in areas of low and high deprivation, according to the English indices of multiple deprivation. Six vignettes were developed featuring data from interviews with people who self-monitor and these were used in five focus groups. Results were thematically analysed. Results Themes derived in the thematic analysis largely reflected topics covered by the vignettes. These included: advice on purchase of a device; supporting home monitoring; mitigating patient anxiety experienced as a result of home monitoring; valuing patients’ data; and effect of socioeconomic factors. Conclusion The work provides an account of methods used by primary care practitioners in the management of home blood pressure self-monitoring, where guidance may be lacking and primary care practitioners act on their own judgement. Findings complement recent policy documentation, which recognises the need to adopt new ways of working to empower patients (for example, additional support from healthcare assistants), but lacks detail on how this should be done

    DETERMINATION OF OPTIMIZATION WAYS OF RE-PROTHESIS USING VARIOUS SCHEMES GNATHOLOGICAL SUPPORT OF PATIENTS AT THE PREPARATORY STAGE TO THE ORTHOPEDIC CORRECTION OF PATIENTS WITH OCCLUSIVE IATROGENIC DISORDERS OF TOOTH-JAW APPARATUS

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    We brought to the light that one of the the most controversial issues is the moment of adaptation to reconstructive procedures. Often it becomes unclear which and in which order to use medical diagnostic equipment, to training for fixed prosthetic stages. Our studies make it possible to predict not only the treatment time, but the amount of occlusal adjustment in conjunction with the reconstruction of the position of the mandible.One of the most debated issues is the time of adaptation to reconstructive manipulation. Often it becomes unclear how and in what order medical diagnostic equipment should be used in the preparatory stages of the stationary prosthetics. Our studies make it possible to predict not only the treatment time, and the amount of occlusal adjustment in conjunction with the reconstruction of the lower jaw. Keywords: tooth-jaw apparatus, temporomandibular joint, violation functional occlusion, dental surgery, medical diagnostic devices, muscle disorders, adaptation, occlusal splint, occlusal adjustment, chewing muscles, provisional design

    Функціональний стан м’язів зубощелепного апарату до та після лікування дітей з аномаліями прикусу та мовленнєвими порушеннями

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    During the examination of orthodontic patients, children with speech disorders were found. The myodynamic balance of antagonistic muscles and synergistic muscles is the relative stability of masticatory and mimic muscles, which for a long time persists without noticeable oscillations, contributes to the relatively stable state of dentoalveolar apparatus. The aim of the study – to determine the functional status of muscles of the dentoalveolar apparatus before and after treatment of children with anomalies of bite and speech disorders. Materials and Methods. To achieve study objectives for treatment we selected 44 patients with severe orthodontic pathology and speech disorders, with normal hearing and intellect. The method of a total (surface) electromyography was used to determine and analyze the indices of bioelectric activity of the muscles. Results and Discussion. There was normalization of parameters of bioelectric activity, decrease of parafunctional manifestations in muscles and decrease of the frequency of outbreaks of spontaneous activity of muscles at rest; normalization of the average amplitude of biopotentials in the state of activity, absence of fragmentation, improvement of synchronization and coordination of contractions of examined muscles in all pathologies of dental occlusion after the treatment. Conclusions. The orthodontic treatment performed provided the restoration of the neuromuscular balance of the dentoalveolar apparatus of patients with various dental occlusion pathologies, which has a beneficial effect on the correction of speech disorders.При обследовании ортодонтических пациентов были дети с речевыми нарушениями. Миодинамическое равновесие мышц-антагонистов и синергистов – это относительная устойчивость жевательных и мимических мышц, которая в течении длительного времени сохраняется без заметных изменений, способствует относительной стабильности зубочелюстного аппарата. Цель исследования – определить функциональное состояние мышц зубочелюстного аппарата до и после лечения детей с аномалиями прикуса и речевыми нарушениями. Материалы и методы. Для достижения поставленной цели было принято на лечение 44 пациента с выраженной ортодонтической патологией и речевыми нарушениями с нормальным слухом и интеллектом. Для определения и анализа показателей биоэлектрической активности мышц использован метод суммарной (поверхностной) электромиографии. Результаты исследований и их обсуждение. После проведённого лечения наблюдали нормализацию показателей биоэлектрической активности, уменьшение парафункциональних проявлений в мышцах и частоты вспышек спонтанной активности мышц в состоянии покоя, нормализация средней амплитуды биопотенциалов в состоянии активности, отсутствие фрагментаций, улучшение синхронности и координации сокращений обследованных мышц при всех патологиях прикуса. Выводы. Проведённое ортодонтическое лечение обеспечило восстановление нейромышечного баланса зубочелюстного аппарата пациентов с различными патологиями прикуса, что имеет благоприятное воздействие на коррекцию речевых нарушений.Під час обстеження ортодонтичних пацієнтів були діти з мовленнєвими порушеннями. Міодинамічна рівновага м’язів-антагоністів та синергістів – це відносна стійкість жувальних та мімічних м’язів, що протягом тривалого часу зберігається без помітних коливань, сприяє відносно стабільного стану зубощелепного апарату. Мета дослідження – визначити функціональний стан м’язів зубощелепного апарату до та після лікування дітей з аномаліями прикусу та мовленнєвими порушеннями. Матеріали і методи. Для досягнення поставленої мети було прийнято на лікування 44 пацієнти з вираженою ортодонтичною патологією та мовленнєвими порушеннями із нормальним слухом та інтелектом. Для визначення та аналізу показників біоелектричної активності м’язів використано метод сумарної (поверхневої) електроміографії. Результати досліджень та їх обговорення. Після проведеного лікування спостерігали нормалізацію показників біоелектричної активності, зменшення парафункціональних проявів у м’язах та частоти спалахів спонтанної активності м’язів у стані спокою, нормалізація середньої амплітуди біопотенціалів у стані активності, відсутність фрагментацій, покращення синхронності та координації скорочень обстежених м’язів при усіх патологіях прикусу. Висновки. Проведене ортодонтичне лікування забезпечило відновлення нейром’язового балансу зубощелепного апарату пацієнтів із різними патологіями прикусу, що має сприятливий вплив на корекцію мовленнєвих порушень
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