Evaluación de un implante de células madre mesenquimales modificadas genéticamente con proteínas morfogenéticas de huesos para la osteogénesis en ovis aries

Propósito y Método del Estudio: Introducción. La generación de implantes para el tratamiento y regeneración de afecciones del tejido óseo representan una enorme oportunidad de desarrollo e innovación para muchos campos de la salud humana. Metodología: nosotros generamos un implante de tres componentes (I-3C) constituido por células madre mesenquimales (CMMs), transducidas ex vivo con un vector adenoviral que expresa una combinación de las proteínas morfogenéticas de hueso 2 y 7 (AdBMP2/7), embebidas en una matriz ósea desmineralizada (MOD). Este implante fue probado en un modelo ovino (Ovis aries) en una lesión sometida a carga. Resultados: los ensayos in vitro demostraron que el tratamiento seleccionado con mayor potencial osteogénico es el que contiene la combinación AdBMP2/7 comprobado por PCR en tiempo real, Western Blot y tinciones histológicas e inmunohistoquímicas para las proteínas marcadoras de inducción a hueso, osteocalcina y colágeno tipo I. El implante fue colocado en la zona de la lesión, creada por una distracción en la diáfisis media de la tibia. Se probaron tres grupos de experimentación: control 1 sin implante (S-I); control 2 implante con CMMs (I-CMMs); implante de 3 componentes CMMs modificadas genéticamente con adenovirus que expresan proteínas morfogenéticas de hueso 2 y 7 que se encuentran embebidas en una matriz de hueso desmineralizado (I-3C). Resultados: el seguimiento radiográfico por 10 semanas después de la distracción ósea demostró una reducción en el tiempo de consolidación del grupo I-3C. La tomografía computarizada demostró en ese mismo grupo, una forma y estructura del hueso postmortem muy parecida a la de una tibia sin lesión. Estos hallazgos fueron corroborados por los ensayos de compresión e histológicos, demostrando que la calidad del hueso nuevo formado fue mayor que la de los grupos sin implante y con CMMs sin modificación genética. Contribuciones y Conclusiones: se logró desarrollar un implante de tres componentes constituido por células madre mesenquimales (CMMs), transducidas ex vivo con un vector adenoviral que expresa una combinación de las proteínas morfogenéticas de hueso 2 y 7 (AdBMP2/7), que nos permitirá continuar con los estudios clínicos necesarios para evaluar principalmente defectos en huesos y enfermedades relacionadas con el sistema óseo.

Desenvolvimento e caracterização de um compósito matriz metálica (CMM): aço EUROFER97 reforçado com Carbeto de Tântalo - TaC

Steel is an alloy EUROFER promising for use in nuclear reactors, or in applications where the material is subjected to temperatures up to 550 ° C due to their lower creep resistance under. One way to increase this property, so that the steel work at higher temperatures it is necessary to prevent sliding of its grain boundaries. Factors that influence this slip contours are the morphology of the grains, the angle and speed of the grain boundaries. This speed can be decreased in the presence of a dispersed phase in the material, provided it is fine and homogeneously distributed. In this context, this paper presents the development of a new material metal matrix composite (MMC) which has as starting materials as stainless steel EUROFER 97, and two different kinds of tantalum carbide - TaC, one with average crystallite sizes 13.78 nm synthesized in UFRN and another with 40.66 nm supplied by Aldrich. In order to improve the mechanical properties of metal matrix was added by powder metallurgy, nano-sized particles of the two types of TaC. This paper discusses the effect of dispersion of carbides in the microstructure of sintered parts. Pure steel powders with the addition of 3% TaC UFRN and 3% TaC commercial respectively, were ground in grinding times following: a) 5 hours in the planetary mill for all post b) 8 hours of grinding in the mill Planetary only for steel TaC powders of commercial and c) 24 hours in the conventional ball mill mixing the pure steel milled for 5 hours in the planetary mill with 3% TaC commercial. Each of the resulting particulate samples were cold compacted under a uniaxial pressure of 600MPa, on a cylindrical matrix of 5 mm diameter. Subsequently, the compressed were sintered in a vacuum furnace at temperatures of 1150 to 1250 ° C with an increment of 20 ° C and 10 ° C per minute and maintained at these isotherms for 30, 60 and 120 minutes and cooled to room temperature. The distribution, size and dispersion of steel and composite particles were determined by x-ray diffraction, scanning electron microscopy followed by chemical analysis (EDS). The structures of the sintered bodies were observed by optical microscopy and scanning electron accompanied by EDS beyond the x-ray diffraction. Initial studies sintering the obtained steel EUROFER 97 a positive reply in relation to improvement of the mechanical properties independent of the processing, because it is obtained with sintered microhardness values close to and even greater than 100% of the value obtained for the HV 333.2 pure steel as received in the form of a bar

Compósitos de matriz metálica à base níquel com adição de TaC e NbC produzidos via metalurgia do pó

Carbide reinforced metallic alloys potentially improve some important mechanical properties required for the overall use of important engineering materials such as steel and nickel. Nevertheless, improved performance is achieved not only by composition enhancement but also by adequate processing techniques, such as novel sintering methods in the case of powder metallurgy. The method minimizes energy losses in addition to providing uniform heating during sintering. Thus, the general objective of this study was to evaluate the density, hardness, flexural strength, dilatometric behavior and to analyze the microstructure of metal matrix composites based nickel with addition of carbides of tantalum and / or niobium when sintered in a conventional furnace and Plasma assisted debinding and sintering (PADS). Initially, were defineds best parameters of granulation, screening and mixing procedure. After, mixtures of carbonyl Ni and 5%, 10% and 15 wt.% NbC and TaC were prepared in a Y-type mixer under wet conditions during 60 minutes. The mixtures were then dried and granulated using 1.5 wt. % paraffin diluted in hexane. Granulates were cold pressed under 600 MPa. Paraffin was then removed from the pressed pellets during a pre-sintering process carried out in a tubular furnace at 500 °C during 30 min. The heating rate was 3 ºC/min. The pellets were then sintered using either a plasma assisted reactor or a conventional resistive tubular furnace. For both methods, the heating rate was set to 8 ºC/min up to 1150 °C. The holding time was 60 minutes. The microstructure of the sintered samples was evaluated by SEM. Brinell hardness tests were also carried out. The results revealed that higher density and higher hardness values were observed in the plasma-assisted sintered samples. Hardness increased with the concentration of carbides in the Ni-matrix. The flexural strength also increased by adding the carbides. The decline was larger for the sample with addition of 5% 5% TaC and NbC. In general, compositions containing added carbide 10% showed less porous and more uniform distribution of carbides in the nickel matrix microstructural appearance. Thus, both added carbide and plasma sintering improved density, hardness, flexural strength and microstructural appearance of the composites

Reabsorción radicular externa apical en incisivos y caninos superiores e inferiores sometidos a tratamiento de Ortodoncia en etapa inicial

La Reabsorción radicular externa apical es un proceso inflamatorio común asociado con el tratamiento de ortodoncia. El objetivo de este estudio fue comparar la magnitud de la RREA de los incisivos y caninos superiores e inferiores en pacientes sometidos a la fase inicial del tratamiento de ortodoncia con tres diferentes tipos de brackets. La muestra consistió en 23 casos de pacientes con edades comprendidas entre 12 y 27 años, fueron divididos aleatoriamente en 3 grupos. Grupo I (n=9; 5 mujeres y 4 varones), utilizando brackets pasivos de autoligado Damon Q Grupo II (n= 8; 4 mujeres y 4 varones) utilizando brackets convencionales prescripción Roth y MBT. Grupo III (n=6; 4 mujeres y 2 varones) utilizando brackets Biofuncional QR. Se analizaron 264 dientes (caninos e incisivos superiores e inferiores) mediante el uso de tomografía computarizada de haz cónico (NewTom VGi Cone Beam 3D Imaging), con el escáner NNT Viewer (versión 4.6 NewTom). Los resultados obtenidos indican que la media de reabsorción se mostró distinta para los diferentes protocolos de tratamiento, así como diferente de acuerdo a la pieza analizada, sin embargo, la prueba de ANOVA no encontró diferencias estadísticamente significativas al comparar la media de reabsorción de cada pieza por tipo de brackets empleados o tratamiento realizado (p >0,05). Se concluye que la RREA se ha producido en todos los dientes evaluados, durante los 6 primeros meses de tratamiento y el diseño del bracket (autoligado pasivo, convencional o QR) no influye en el grado de reabsorción radicular.

Manual pedagógico de queratometría y refracción convencional y computarizada (equipo huvitz hrk 7000)

Tesis (Optometra). -- Universidad de La Salle, Facultad de Ciencias de La Salud. Programa de Optometria, 2015

Lattice pulling effect and strain relaxation in axial (In, Ga)N/GaN nanowire heterostructures grown on GaN-buffered Si(111) substrate

Transmission electron microscopy and spatially resolved electron energy-loss spectroscopy have been applied to investigate the indium distribution and the interface morphology in axial (In,Ga)N/GaN nanowire heterostructures. The ordered axial (In,Ga)N/GaN nanowire heterostructures with an indium concentration up to 80% are grown by molecular beam epitaxy on GaN-buffered Si(111) substrates. We observed a pronounced lattice pulling effect in all the nanowire samples given in a broad transition region at the interface. The lattice pulling effect becomes smaller and the (In,Ga)N/GaN interface width is reduced as the indium concentration is increased in the (In,Ga)N section. The result can be interpreted in terms of the increased plastic strain relaxation via the generation of the misfit dislocations at the interface.

Short-term and long-term changes in corneal power are not correlated with axial elongation of the eye induced by orthokeratology in children

PURPOSE: To assess the relationship between short-term and long-term changes in power at different corneal locations relative to the change in central corneal power and the 2-year change in axial elongation relative to baseline in children fitted with orthokeratology contact lenses (OK). METHODS: Thirty-one white European subjects 6 to 12 years of age and with myopia −0.75 to −4.00 DS and astigmatism ≤1.00 DC were fitted with OK. Differences in refractive power 3 and 24 months post-OK in comparison with baseline and relative to the change in central corneal power were determined from corneal topography data in eight different corneal regions (i.e., N[nasal]1, N2, T[temporal]1, T2, I[inferior]1, I2, S[superior]1, S2), and correlated with OK-induced axial length changes at two years relative to baseline. RESULTS: After 2 years of OK lens wear, axial length increased by 0.48±0.18 mm (P0.05). CONCLUSION: The reduction in central corneal power and relative increase in paracentral and pericentral power induced by OK over 2 years were not significantly correlated with concurrent changes in axial length of white European children.

Asociación entre la escala de riesgo Framingham y el puntaje de calcio coronario

Introducción: Entre las diferentes herramientas clínicas para evaluar la presencia de enfermedad coronaria mediante puntajes, la más usada es la Escala de Riesgo cardiovascular de Framingham. Desde hace unos años, se creó el puntaje de calcio coronario el cual mide el riesgo cardiovascular según la presencia de placas ateromatosas vistas por tomografía computarizada. Se evaluó la asociación entre la escala de Framigham y el puntaje de calcio coronario en una población de sujetos sanos asintomáticos. Metodología: Se realizó un estudio transversal para evaluar la asociación entre el puntaje de calcio coronario y la escala de Framingham en sujetos asintomáticos que se practicaron exámen médico preventivo en la Fundación Cardioinfantil- Instituto de Cardiología (FCI-IC) en el periodo comprendido entre 1 de Julio 2011 hasta el 31 de octubre de 2015. Resultados: Se evaluaron 262 pacientes en total. La prevalencia de riesgo cardiovascular fue bajo en un 77.86% de la población, medio en 18.70% y alto en 3.44%, según la escala de Framingham. El riesgo cardiovascular según el puntaje de Calcio coronario fue nulo 70.99%, bajo en 21.75%, medio en 4.19%, severo en 3.05%. Se encontró una asociación entre ambos puntajes para riesgo estadísticamente significativa (p0,00001) Discusión: El riesgo cardiovascular establecido por escala de Framingham se relaciona de forma significativa con la presencia de placas aterioscleróticas. El estudio demostró que en una muestra de sujetos asintomáticos, hay una alteración estructural coronaria temprana.

Índice acumulativo de riesgo (nice) como prueba diagnóstica con base en tomografía corneal por elevación en la prevención de ectasia corneal post-lasik

Antecedentes La ectasia corneal post-lasik (ECPL) es una complicación infrecuente, pero devastadora en la cirugía lasik (queratomileusis asistida con éxcimer láser) para el tratamiento de la miopía con o sin astigmatismo. Con base en la tomografía corneal por elevación por imágenes de Scheimpflug (Sistema Pentacam HR, Oculus Wetzlar, Alemania), se propone un novedoso índice acumulativo de riesgo para ser utilizado como prueba diagnóstica de tamizaje y así prevenir esta complicación. Metodología Se realizó un estudio observacional analítico, de corte transversal tipo pruebas diagnósticas, con el fin de evaluar las características operativas del índice NICE teniendo como estándar de referencia el módulo de Belin-Ambrosio (Pentacam HR) utilizando un modelo de regresión logística binaria, tablas de contingencia y estimando el área bajo la curva ROC. Resultados Se evaluaron 361 ojos de los cuales el 59,3% provenían de pacientes de sexo femenino, la edad media global fue de 30 años (RIC 11,0). El modelo logístico binario aplicado se construyó con base en cuatro variables independientes cuantitativas (K2, PAQUI, EP e I-S) y una cualitativa (SEXO), y se determinó su relación con la variable dependiente, NICE (puntaje final). Las variables predictoras fueron estadísticamente significativas clasificando adecuadamente el 92,9% de los ojos evaluados según presencia o ausencia de riesgo. El coeficiente de Nagelkerke fue de 74,4%. Conclusiones El índice acumulativo de riesgo NICE es una herramienta diagnóstica novedosa en la evaluación de candidatos a cirugía refractiva lasik para prevenir la ectasia secundaria.

PENSAR UNIVERSAL: SAMBA DE COCO PARELHA TROCADA E O TIC TAC DO TEMPO

O trabalho tem como objetivo discutir através da dança o resgate da identidade cultural da comunidade quilombola Estrela, localizada no nordeste do Brasil, analisada nos seus respectivos contextos sócio históricos, abordados a partir da dança: Samba de Coco Parelha Trocada como elemento da trajetória histórica dessa comunidade afro descendente, marco nas lutas em defesa da identidade dessa comunidade. Para discutir a temática, necessário se faz entender criticamente o significado dos conceitos: aprender a conhecer aprender a fazer, aprender a ser e aprender a conviver, superando o individualismo e dando ênfase ao coletivo como entendimento principal às questões culturais. Para o desenvolvimento do trabalho se faz necessário uma abordagem metodológica ancorada na perspectiva dialógica, etnográfica, com o aporte do referencial teórico histórico materialista, na perspectiva de investigar e mediar um processo de construção de conhecimentos que ressalte e permita o estabelecimento de relações entre a teoria e a realidade social em que vive essa comunidade. Como achados iniciais destacamos a compreensão da comunidade a partir da identidade cultural advinda do samba de coco de parelha trocada.

The role of CD8+CCR4+ T-cells in axial spondyloarthritis

Axial spondyloarthritis (AxSpA) is an inflammatory disease affecting the axial skeleton. The infiltrate of T-cells in the structural lesions has been found to contribute to bone remodeling, but consensus relating the functional contribution of different T-cell subsets to pathogenesis has not been reached yet. Aim of the project was to characterize circulating T-cells and their homing markers from axSpA patients in order to identify cellular populations that could migrate to inflamed tissues and be implicated in axSpA. We found an altered proportion of circulating naïve and memory T-cells in axSpA patients, and a skew in favor of CD8+ T-cells expressing the chemokine receptor CCR4. Since CCL17 and CCL22, the two ligands for CCR4, are found to be elevated in the sera of axSpA patients, we investigated in details the role of CD8+CCR4+ T cells in axSpA. Our data showed that circulating CD8+CCR4+ T-cells display an effector memory phenotype and express homing markers for tissues that are target of the disease. Noteworthy, CD8+CCR4+ T cells from axSpA patients were activated, expressed markers of proliferation and acquired a cytotoxic phenotype, as demonstrated by the increased production of granzyme and perforin. CD8+CCR4+ T cells from axSpA patients upregulate the transcription of genes involved in bone mineralization and downregulate genes involved in osteoclast differentiation, indicating their possible involvement in bone remodeling. Furthermore, CD8+CCR4+ T cells stimulated with PMA and ionomycin were able to produce and release TNF and IL-8, two cytokines involved in osteoclastogenesis, indicating that CD8+CCR4+ T-cells after stimulation would be able to promote osteoclasts differentiation and neutrophils recruitment. Taken together our data suggest that CD8+CCR4+ T cells might exert a pathogenic role in axSpA, by releasing mediators of tissue damage, bone remodeling and recruitment of other pro inflammatory cells.

Structural Connectivity Of The Default Mode Network And Cognition In Alzheimer׳s Disease.

Disconnectivity between the Default Mode Network (DMN) nodes can cause clinical symptoms and cognitive deficits in Alzheimer׳s disease (AD). We aimed to examine the structural connectivity between DMN nodes, to verify the extent in which white matter disconnection affects cognitive performance. MRI data of 76 subjects (25 mild AD, 21 amnestic Mild Cognitive Impairment subjects and 30 controls) were acquired on a 3.0T scanner. ExploreDTI software (fractional Anisotropy threshold=0.25 and the angular threshold=60°) calculated axial, radial, and mean diffusivities, fractional anisotropy and streamline count. AD patients showed lower fractional anisotropy (P=0.01) and streamline count (P=0.029), and higher radial diffusivity (P=0.014) than controls in the cingulum. After correction for white matter atrophy, only fractional anisotropy and radial diffusivity remained significantly lower in AD compared to controls (P=0.003 and P=0.05). In the parahippocampal bundle, AD patients had lower mean and radial diffusivities (P=0.048 and P=0.013) compared to controls, from which only radial diffusivity survived for white matter adjustment (P=0.05). Regression models revealed that cognitive performance is also accounted for by white matter microstructural values. Structural connectivity within the DMN is important to the execution of high-complexity tasks, probably due to its relevant role in the integration of the network.

Profile Of The Use Of Disease Modifying Drugs In The Brazilian Registry Of Spondyloarthritides.

Few studies have evaluated the profile of use of disease modifying drugs (DMD) in Brazilian patients with spondyloarthritis (SpA). A common research protocol was applied prospectively in 1505 patients classified as SpA by criteria of the European Spondyloarthropathies Study Group (ESSG), followed at 29 referral centers in Rheumatology in Brazil. Demographic and clinical variables were obtained and evaluated, by analyzing their correlation with the use of DMDs methotrexate (MTX) and sulfasalazine (SSZ). At least one DMD was used by 73.6% of patients: MTX by 29.2% and SSZ by 21.7%, while 22.7% used both drugs. The use of MTX was significantly associated with peripheral involvement, and SSZ was associated with axial involvement, and the two drugs were more administered, separately or in combination, in the mixed involvement (p < 0.001). The use of a DMD was significantly associated with Caucasian ethnicity (MTX , p = 0.014), inflammatory back pain (SSZ, p = 0.002) , buttock pain (SSZ, p = 0.030), neck pain (MTX, p = 0.042), arthritis of the lower limbs (MTX, p < 0.001), arthritis of the upper limbs (MTX, p < 0.001), enthesitis (p = 0.007), dactylitis (MTX, p < 0.001), inflammatory bowel disease (SSZ, p < 0.001) and nail involvement (MTX, p < 0.001). The use of at least one DMD was reported by more than 70% of patients in a large cohort of Brazilian patients with SpA, with MTX use more associated with peripheral involvement and the use of SSZ more associated with axial involvement.

Feasibility And Reproducibility Of Diffusion-weighted Magnetic Resonance Imaging Of The Fetal Brain In Twin-twin Transfusion Syndrome.

The aim of this study is to test the feasibility and reproducibility of diffusion-weighted magnetic resonance imaging (DW-MRI) evaluations of the fetal brains in cases of twin-twin transfusion syndrome (TTTS). From May 2011 to June 2012, 24 patients with severe TTTS underwent MRI scans for evaluation of the fetal brains. Datasets were analyzed offline on axial DW images and apparent diffusion coefficient (ADC) maps by two radiologists. The subjective evaluation was described as the absence or presence of water diffusion restriction. The objective evaluation was performed by the placement of 20-mm(2) circular regions of interest on the DW image and ADC maps. Subjective interobserver agreement was assessed by the kappa correlation coefficient. Objective intraobserver and interobserver agreements were assessed by proportionate Bland-Altman tests. Seventy-four DW-MRI scans were performed. Sixty of them (81.1%) were considered to be of good quality. Agreement between the radiologists was 100% for the absence or presence of diffusion restriction of water. For both intraobserver and interobserver agreement of ADC measurements, proportionate Bland-Altman tests showed average percentage differences of less than 1.5% and 95% CI of less than 18% for all sites evaluated. Our data demonstrate that DW-MRI evaluation of the fetal brain in TTTS is feasible and reproducible.

Management Of Severe Thoracic Impalement Trauma Against Two-wheeled Horse Carriage: A Case Report And Literature Review.

Thoracic injuries in general are of great importance due to their high incidence and high mortality. Thoracic impalement injuries are rare but severe due to the combination of cause, effect and result. This study's primary objective is to report the case of a young man who was impaled by a two-wheeled horse carriage shaft while crashing his motorcycle in a rural zone. An EMT-B ferry was called at the crash scene and a conscious patient was found, sustaining a severe impalement injury to the left hemithorax, suspended over the floor by the axial skeleton with the carriage shaft coming across his left chest. As a secondary objective, a literature review of thoracic impalement injuries is performed. Cases of thoracic impalement injury require unique and individualized care based on injury severity and affected organs. Reported protocols for managing impalement injuries are entirely anecdotal, with no uniformity on impaled patient's approach and management. In penetrating trauma, it is essential not to remove the impaled object, so that possible vascular lesions remain buffered by the object, avoiding major bleeding and exsanguination haemorrhage. Severed impaled thoracic patients should be transferred to a specialist centre for trauma care, as these lesions typically require complex multidisciplinary treatment. High-energy thoracic impalement injuries are rare and hold a high mortality rate, due to the complexity of trauma and associated injuries such as thoracic wall and lung lesions. Modern medicine still seems limited in cases of such seriousness, not always with satisfactory results.