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1.
Med. oral patol. oral cir. bucal (Internet) ; 24(5): e652-e658, sept. 2019. ilus, graf
Artigo em Inglês | IBECS | ID: ibc-185684

RESUMO

Background: The aim of this study was to assess the effect of local application of IGF-I on osseointegration of dental implants placed in osteoporotic bones. Material and Methods: 16 rabbits were randomly distributed into two groups: eight animals were ovariectomized and fed a low-calcium diet for six weeks, in order to induce experimental osteoporosis, and the others were sham-operated and fed a standard diet. A titanium implant was inserted into the tibiae in both groups. In half of the rabbits, 4 μg of IGF-I was applied into the ostectomy, prior to the implant insertion. A total of 32 implants were placed. Animals were sacrificed two weeks after surgery and decalcified samples were processed for Bone-To-Implant Contact (BIC) and Bone Area Density (BAD) measurements. Analysis of variance (ANOVA) was used for statistical evaluation. P < 0.05 was considered to be significant. Results: Ovariectomy induced statistically significant lower BAD values (p = 0.008) and a tendency towards lower BIC values when compared osteoporotic and healthy groups. The administration of 4 μg of IGF-I did not produce statistically significant differences neither on BIC nor on BAD values, neither in the osteoporotic animals nor in healthy. Conclusions: Within the limitations of this experimental study, local administration of 4 μg of IGF-I was not able to induce any changes in the osseointegration process two weeks after surgery, neither in healthy rabbits nor in the osteoporotic group


No disponible


Assuntos
Humanos , Animais , Feminino , Coelhos , Implantes Dentários , Osteoporose , Densidade Óssea , Fator de Crescimento Insulin-Like I , Osseointegração , Titânio
2.
Med. oral patol. oral cir. bucal (Internet) ; 24(4): e502-e510, jul. 2019. ilus, tab, graf
Artigo em Inglês | IBECS | ID: ibc-185664

RESUMO

Background: To evaluate the effect of two different implant macro-designs on the sequential osseointegration at bicortically installed implants in the rabbit tibia. A further aim is to compare the osseointegration at different topographic zones. Material and Methods: 27 New Zealand rabbits were implemented. Two implants, one for each macro-design (Ticare Inhex(R) or Ticare Quattro(R), Mozo-Grau, Valladolid, Spain), were randomly implanted in the diaphysis or metaphysis of each tibia. The flaps were sutured to allow a submerged healing. The animals were sacrificed after 2, 4 or 8 weeks. Ground sections were prepared and analyzed. Results: No statistically significant differences were found between the two groups for newly formed bone in contact with the implant surface, being about 16%, 19% and 33% in both groups, after 2, 4, and 8 weeks of healing. Bone apposition was slightly higher in the diaphysis, reaching values of 36.4% in the diaphysis, and 29.3% in the metaphysis at 8 weeks of healing. It was observed that the implant position showed a statistical significance regarding BIC values at 4 and 8 weeks (p < 0.05). Multivariate analysis fails to detect statistical significant differences for the interaction between implant designs and topographic site. Ticare Quattro(R) design had a slight better BIC values at diaphysis sites across healing stages, but without reaching a statistical significance. Conclusions: The both implant macro-designs provided similar degrees of osseointegration. Bone morphometry and density may affect bone apposition onto the implant surface. The apposition rates were slightly better in diaphysis compared to metaphysis


No disponible


Assuntos
Animais , Coelhos , Implantes Dentários , Osseointegração , Implantação Dentária Endo-Óssea , Propriedades de Superfície , Tíbia , Titânio
3.
Rev. esp. cir. ortop. traumatol. (Ed. impr.) ; 63(2): 146-154, mar.-abr. 2019. ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-188897

RESUMO

La fractura de la extremidad proximal de fémur es objeto de interés en investigación. La complejidad del entramado óseo y la ineficiencia estructural asociada al envejecimiento hacen que existan muchas variables todavía por comprender desde el punto de vista experimental, pero no existe un modelo de investigación estructural y biomecánico de la fractura de cadera claramente definido. La hipótesis de este trabajo es que es posible desarrollar un modelo de experimentación computacional que caracterice el hueso de la extremidad proximal del fémur como un material heterogéneo a partir de la traslación directa de los parámetros mecánicos obtenidos de piezas anatómicas de experimentación. Material y método: Trabajo experimental que compara la experimentación real en cadáver y un modelo numérico basado en análisis de elementos finitos (AEF). Las variables que se han empleado son: punto de inicio de la fractura, su propagación, carga progresiva y la carga máxima hasta fractura. Al modelo computacional se trasladaron los parámetros mecánicos reales obtenidos de las piezas anatómicas basándose en la relación entre las unidades Hounsfield de la TAC de alta resolución y la densidad mineral ósea de cada elemento virtual, mientras que la propagación de la fractura se modeló mediante desarrollo computacional propio del equipo investigador, con disminución de las propiedades mecánicas de los elementos dañados conforme avanza la línea fractuaria. Resultados: El modelo computacional fue capaz de determinar el punto de inicio de la fractura, con una discreta tendencia a la medialización anatómica de dicho punto respecto a lo ocurrido de manera experimental. El grado de correlación fue muy alto al comparar el valor real de deformación progresiva de las muestras frente al obtenido por el modelo computacional. Sobre 32 puntos analizados, se obtuvo una pendiente de 1,03 en regresión lineal, con un error relativo entre las deformaciones del 6% y un coeficiente de Pearson de R2=0,99. El modelo computacional infraestimó discretamente la carga máxima de fractura, con un error relativo aproximado al 10%. Conclusión: El modelo computacional de AEF desarrollado por este equipo investigador multidisciplinar se puede considerar, en conjunto, un modelo completo de AEF de la extremidad proximal del fémur con aplicabilidad clínica futura al ser capaz de simular e imitar el comportamiento biomecánico de fémures humanos contrastado con un modelo experimental clásico realizado en piezas anatómicas. Sobre esta base podrán evaluarse interacciones cualitativas y cuantitativas que lo consoliden como un potente banco de ensayos de experimentación computacional sobre el fémur proximal humano


Fracture of the proximal extremity of the femur is the subject of research interest. The complexity of the bone framework and the structural inefficiency associated with ageing leave many variables yet to be understood from an experimental perspective. However, there is no clearly defined structural and biomechanical research model for hip fracture. The hypothesis of this paper is that it is possible to create a computational experimentation model that characterises the bone of the proximal extremity of the femur as a heterogeneous material from directly translating the mechanical parameters obtained from anatomical experimentation specimens. Material and method: An experimental paper comparing real experimentation on cadavers and a numerical model based on finite element analysis (FEA). The variables uses were: the start point of the fracture, propagation of the fracture, progressive load and maximum load until fracture. The real mechanical parameters obtained from the anatomical specimens were translated to the computational model based on the relationship between the Hounsfield units of the high resolution CAT scan and the bone mineral density of each virtual element, whereas the propagation of the fracture was modelled by the research team's own computational design, reducing the mechanical properties of the damaged elements as the fracture line advanced. Results: The computational model was able to determine the start point of the fracture, with a slight tendency towards anatomical medialisation of this point compared to what happened experimentally. The degree of correlation was very high on comparing the real value of progressive deformation of the samples compared to that obtained by the computational model. Over 32 points analysed, a slope of 1.03 in lineal regression was obtained, with a relative error between the deformations of 16% and a Pearson's coefficient of R2=.99. The computational model slightly underestimated the maximum fracture load, with a relative error of approximately 10%. Conclusion: The FEA computational model developed by this multi-disciplinary research team could be considered, as a whole, a complete FEA model of the proximal extremity of the femur with future clinical applicability since it was able to simulate and imitate the biomechanical behaviour of human femurs contrasted with a traditional experimental model made from anatomical specimens. On this basis, qualitative and quantitative interactions can be assessed which consolidate it as a powerful computational experimentation test bench for the human proximal femur


Assuntos
Animais , Coelhos , Antibacterianos/administração & dosagem , Cimentos para Ossos , Linezolida/administração & dosagem , Osteomielite/tratamento farmacológico , Osteomielite/microbiologia , Infecções Estafilocócicas/tratamento farmacológico , Vancomicina/administração & dosagem , Modelos Animais de Doenças
4.
Eur. j. anat ; 23(2): 103-111, mar. 2019. ilus, graf
Artigo em Inglês | IBECS | ID: ibc-182420

RESUMO

Degeneration of the intervertebral discs is strongly implicated as the main cause of low back pain. To determine the preventive potential of D-Ribose-L-Cysteine in annular punctured intervertebral disc degeneration in rabbit model. Twenty New Zealand white rabbits (1.5 to 3.0 kg each) underwent annular puncture of the L2-L3, L3-L4, and L4-L5 discs. Group 1 (non-punctured control) were given phosphate-buffered saline; group 2 (model control) were given phosphate-buffered saline immediately after puncture for 4 weeks ; group 3 (punctured treated) were given 150 mg/kg/bw of D-Ribose-L-Cysteine solution immediately after puncture for 4 weeks; group 4 (punctured treated) were given 300 mg/kg/bw of D-Ribose-L-Cysteine solution immediately after puncture for 4 weeks. Rabbits were sacrificed at 4 weeks after puncture. The animals were housed individually in a meshed wire bottom cages with access to water and standard chow ad libitum. The serial X-rays were performed at 0 and 4 weeks for the rabbits and whole spinal column and discs were extracted and analyzed for various histological staining techniques (H&E and HVG), biochemical and immunohistochemical analysis. The X-rays showed a progressive decrease in disc height over timewhich was significantly prevented by the D-Ribose-L-Cysteine administration. The histological grade, collagen type 1 and 2, aggrecan, and matrix metalloprotease-13 mRNA expression and histological analysis were consistently indicative of degeneration, supporting the results of the X-ray data. This study has now documented that D-Ribose-L-Cysteine halts the progression of intervertebral disc degeneration and can be useful as prophylactic agents especially in people prone to disc degeneration


No disponible


Assuntos
Animais , Coelhos , Degeneração do Disco Intervertebral/etiologia , Degeneração do Disco Intervertebral/veterinária , Disco Intervertebral/anatomia & histologia , Modelos Animais , Expressão Gênica , Cisteína/administração & dosagem , Suplementos Nutricionais , Degeneração do Disco Intervertebral/tratamento farmacológico , Disco Intervertebral/efeitos dos fármacos , Imuno-Histoquímica
5.
Cir. plást. ibero-latinoam ; 45(1): 11-18, ene.-mar. 2019. ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-182673

RESUMO

Introducción y Objetivo: Existen diferentes tipos de injertos autólogos y materiales aloplásticos para el tratamiento de las diversas deformidades faciales. El politetrafluoroetileno (PTFE) tiene varias ventajas debido a su propiedad hidrofóbica, que induce menor reacción inflamatoria. Presentamos un estudio que evalúa y compara la reacción inflamatoria inducida por los implantes faciales de silicona y de PTFE. Material y Método: Colocamos fragmentos de implantes de silicona y de PTFE en orejas de conejos mediante incisión y disección de un bolsillo subcutáneo. Realizamos análisis histológico a las 8 semanas: tinción de las muestras con hematoxilina / eosina y calificación del grado de reacción inflamatoria crónica, presencia de neutrófilos, linfocitos, eosinófilos, neoangiogénesis, fibroblastos y edema, presencia o no de hemorragia y valoración de la cicatriz. Hicimos la recolección de muestras para análisis microbiológico y evaluación de la presencia de hematoma y absceso en el momento del sacrificio. Resultados: La prevalencia de abscesos en el sacrificio, el hematoma y el edema durante las primeras semanas, fueron significativamente menores (p <0.05) en el grupo de PTFE. Conclusiones: El PTFE indujo reacción inflamatoria crónica al igual que la silicona, pero con menos absceso, edema y formación de hematomas


Background and Objective: The treatment for many facial deformities uses many kinds of autologous grafts or alloplastic materials. Polytetrafluoroethylene (PTFE) has several advantages due to its hydrophobic properties, inducing less inflammatory reaction. Our study evaluates and compares the inflammatory reaction induced by silicone and PTFE stripes. Methods: Fragments of silicone and PTFE implants were placed in rabbits ears using an incision and a subcutaneous gap. The histological analysis was made 8 weeks later. The samples were stained with hematoxylin/eosin and classified as chronic inflammatory reaction graduation, the presence of neutrophils, lymphocytes, eosinophils, neoangiogenesis, fibroblasts, edema and presence of bleeding and scar. Samples to microbiological analysis and evaluation of bruise and abs- cess were collected at the moment of sacrifice. Results: Prevalence of abscess at sacrifice and hematoma during the first weeks were significantly higher (p>0.05) in the silicon group. Conclusions: PTFE induced as much inflammatory reaction as the silicon but with less abscess and hematoma formation


Assuntos
Animais , Coelhos , Próteses e Implantes/efeitos adversos , Inflamação/induzido quimicamente , Inflamação/veterinária , Politetrafluoretileno/uso terapêutico , Implantes Experimentais/veterinária , Silicones/efeitos adversos , Abscesso/induzido quimicamente , Edema/induzido quimicamente , Hematoma/induzido quimicamente , Fotomicrografia , Implantes de Medicamento/efeitos adversos
6.
J. physiol. biochem ; 74(4): 531-538, nov. 2018. ilus, graf
Artigo em Inglês | IBECS | ID: ibc-179031

RESUMO

Squalene is the main unsaponifiable component of virgin olive oil, the main source of dietary fat in Mediterranean diet, traditionally associated with a less frequency of cardiovascular diseases. In this study, two experimental approaches were used. In the first, New Zealand rabbits fed for 4 weeks with a chow diet enriched in 1% sunflower oil for the control group, and in 1% of sunflower oil and 0.5% squalene for the squalene group. In the second, APOE KO mice received either Western diet or Western diet enriched in 0.5% squalene for 11 weeks. In both studies, liver samples were obtained and analyzed for their squalene content by gas chromatography-mass spectrometry. Hepatic distribution of squalene was also characterized in isolated subcellular organelles. Our results show that dietary squalene accumulates in the liver and a differential distribution according to studied model. In this regard, rabbits accumulated in cytoplasm within small size vesicles, whose size was not big enough to be considered lipid droplets, rough endoplasmic reticulum, and nuclear and plasma membranes. On the contrary, mice accumulated in large lipid droplets, and smooth reticulum fractions in addition to nuclear and plasma membranes. These results show that the squalene cellular localization may change according to experimental setting and be a starting point to characterize the mechanisms involved in the protective action of dietary squalene in several pathologies


No disponible


Assuntos
Animais , Masculino , Coelhos , Membrana Celular/metabolismo , Dieta Mediterrânea , Modelos Animais de Doenças , Fígado/metabolismo , Hepatopatia Gordurosa não Alcoólica/prevenção & controle , Transporte Biológico , Membrana Celular/patologia , Vesículas Citoplasmáticas/metabolismo , Vesículas Citoplasmáticas/patologia , Citosol/metabolismo , Citosol/patologia , Fígado/patologia , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia
7.
Clín. investig. arterioscler. (Ed. impr.) ; 30(5): 209-216, sept.-oct. 2018. ilus, tab, graf
Artigo em Espanhol | IBECS | ID: ibc-175438

RESUMO

Introducción: El resveratrol tiene propiedades antiinflamatorias y antiaterogénicas; sin embargo, se desconoce su efecto sobre el factor de crecimiento endotelial vascular (VEGF) en la aterosclerosis. Objetivo: Evaluar el efecto del resveratrol sobre las concentraciones séricas del VEGF durante la progresión y evolución de la aterosclerosis y su evolución en el tiempo en conejos alimentados con dieta enriquecida con colesterol. Materiales y métodos: Cuarenta y ocho conejos machos divididos en cuatro grupos de 12 conejos recibieron: grupo 1 (control): conejarina; grupo 2: conejarina suplementada con 0,5% colesterol; grupo 3 (control resveratrol): conejarina y resveratrol (2 mg/kg); grupo 4: conejarina suplementada con 0,5% colesterol y resveratrol, durante 12 semanas. Se realizaron determinaciones séricas de triglicéridos, colesterol y sus fracciones, VEGF y proteína C reactiva (PCR) al inicio, a la 6.a y a la 12.a semana de experimentación. La mitad de los conejos fueron sacrificados a la 6.a y a la 12.a semana y se realizó estudio histológico de su aorta. Resultados: El VEGF y la PCR aumentaron en los grupos2 y 4 desde la 6.a semana de experimentación con respecto a los grupos 1 y 3, respectivamente (p < 0,001). En la duodécima semana se observó una disminución de los niveles de VEGF y PCR en el grupo 4 con respecto al grupo 2 (p < 0,004). El tratamiento con resveratrol disminuyó la formación de ateromas. Conclusiones: El VEGF y la PCR séricos constituyen marcadores tempranos no invasivos de inflamación y aterosclerosis. La suplementación oral de resveratrol ejerce efectos antiinflamatorios y antiateroscleróticos, disminuyendo las concentraciones séricas de VEGF y PCR, y la formación y evolución de las lesiones ateroscleróticas


Introduction: Although it is known that resveratrol has anti-inflammatory and anti-atherogenic actions, its effect on vascular endothelial growth factor (VEGF) in atherosclerosis is unknown. Objective: To evaluate the effect of resveratrol on serum concentrations of VEGF during the progression and evolution of atherosclerosis, as well as and its evolution over time in rabbits fed with a cholesterol diet. Materials and methods: A total of 48 New Zealand white male rabbits were randomly divided into four groups of 12 rabbits: group 1 (control): standard diet (commercial rabbit food); group 2: cholesterol diet (0.5% cholesterol); group 3 (control resveratrol): standard diet (commercial rabbit food) and resveratrol (2 mg/Kg); group 4: cholesterol diet (0.5% cholesterol) and resveratrol (2 mg/Kg), for 12 weeks. Blood samples of overnight-fasted rabbits were collected at baseline and the sixth and twelfth weeks, and the lipid profile, VEGF, and C-reactive protein (CRP) levels were determined. Half of the animals were sacrificed on the sixth or twelfth week, and the aorta was dissected for histological studies. Results: VEGF and CRP levels were significantly higher in groups 2 and 4 than in groups1 and 3, respectively, from the 6th week (p < 0.001). VEGF and CRP were significantly lower in group 4 than in group 2 on 12 th week (p < 0.004). Supplementation of resveratrol reduced the formation of atherosclerotic lesions. Conclusions: Serum VEGF and CRP levels are early markers of atherosclerosis. Oral supplementation of resveratrol exerts anti-inflammatory and anti-atherosclerotic effects, decreasing serum concentrations of VEGF and CRP and the formation and evolution of atherosclerotic lesions


Assuntos
Animais , Coelhos , Aterosclerose/fisiopatologia , Fatores de Crescimento do Endotélio Vascular/sangue , Anti-Inflamatórios não Esteroides/uso terapêutico , Aterosclerose/tratamento farmacológico , Fatores de Crescimento do Endotélio Vascular , Colesterol na Dieta , Coelhos/metabolismo , Triglicerídeos/análise , Proteína C-Reativa/análise , Biomarcadores
8.
Av. odontoestomatol ; 34(3): 141-149, mayo-jun. 2018. ilus
Artigo em Espanhol | IBECS | ID: ibc-173005

RESUMO

La superficie de los implantes es muy importante para conseguir la oseointegración. Existen muchos tipos de superficies en los implantes dentales. La investigación en superficie de implantes comienza con la superficie mecanizada. La superficie rugosa incrementa la adherencia celular y muestra una mayor área de contacto hueso-implante. El recubrimiento con plasma de titanio e hidroxiapatita fueron métodos comunes para modificar la rugosidad de la superficie. Más recientemente, el arenado (ej. alúmina) y el grabado ácido (ej. chorhídrico, sulfúrico, nítrico) son otros procesos que pueden incrementar la superficie rugosa de los implantes. Más recientemente, la tecnología ha comenzado en la implantología oral con el desarrollo de superficies porosas que manifiestan una mejor respuesta osteogénica e incrementa la unión mecánica hueso-titanio. La oseointegración parece estar influenciada por los modelos de especies animales. En el conejo el proceso es más rápido que en el perro, y en el perro es más rápido que en el hombre. La incorporación de nuevos materiales y procesos técnicos en la investigación sobre superficies de implantes ofrecen nuevas posibilidades de mejorar su respuesta tisular y su potencial óseo regenerativo. Conclusiones: El tratamiento de la superficie de los implantes constituye un importante campo en futuras investigaciones de la implantología oral mediante los estudios de experimentación


Implant surface is very important for enhance the osseointegration. They are many types of dental implant surfaces. Implant surface research begins with machined surface. Roughened surface titanium increase cell adhesion and exhibit stronger bone-implant contact area. Plasma-spray and hydroxyapatite coating were common methods for rough surface modification. Most recently, blasting (i.e. alumina) and acid-etching (i.e. hydrochloric, sulphuric and nitric) are another process by which surface roughness can be increased. Most recently, technology begins in implant dentistry with the development of porous surfaces that manifest better osteogenic response and increase bone-titanium mechanical interlocking. Osseointegration appeared to be strongly influenced by the animal species model. The rabbit model was faster compared to the dog model, and the dog model was faster the human model. The introduction of new materials and new technical process in dental surfaces research offering new possibilities for better tissue response and bone regenerative potential. Conclusions: The surface modifications of titanium constitute an important field for future research of implant dentistry by experimental studies


Assuntos
Animais , Coelhos , Implantação Dentária Endo-Óssea/métodos , Implantes Dentários/efeitos adversos , Titânio/uso terapêutico , Osseointegração , Materiais Revestidos Biocompatíveis , Interface Osso-Implante/anatomia & histologia , Propriedades de Superfície
9.
J. optom. (Internet) ; 11(2): 69-74, abr.-jun. 2018. graf, tab
Artigo em Inglês | IBECS | ID: ibc-172719

RESUMO

Purpose/aim: Glaucoma consists of a group of progressive optic neuropathies that are characterized by degeneration of the optic nerve and irreversible visual filed loss. Elevated intraocular pressure is the only proven treatable risk factor and commercial products used for glaucoma treatment are focused in lowering intraocular pressure. These drugs can have various undesirable side effects and this invites to look for new strategies. The purpose of this work is to study the use of a siRNA (small interfering RNA) to selectively silence beta2 adrenergic receptors and to see whether it reduces IOP (intraocular pressure). Material and methods: Topical instillation of beta2 adrenergic receptors small-interfering RNA (siRNA, 25-250 g) was applied and IOP was measured with a Tonopen XL up to 9 consecutive days. The effect of such siRNA was compared to commercial compounds such as Timoftlol, Trusopt and Xalatan, and it was also analyzed if some anatomical changes occurred by microscopy. Results: siRNA designed for beta2 adrenergic receptor induced a reduction of intraocular pressure (IOP) of 30 ± 5%, compared to a control (scrambled siRNA). The results in terms of IOP decrease were similar to that found with commercial compounds but a long-lasting hypotensive action was shown by beta2 adrenergic receptor siRNA treatment as compared to commercial drugs. No apparent side effects were observed in the ocular structures. Conclusion: The use of siRNA against the beta2 adrenergic receptors could provide an interesting therapeutic strategy for glaucoma treatment


Objetivo: El glaucoma consiste en un grupo de neuropatías ópticas progresivas caracterizadas por degeneración del nervio óptico y pérdida irreversible del campo visual. La elevación de la presión intraocular es el único factor de riesgo tratable probado, centrándose los productos comerciales para el tratamiento del glaucoma en la reducción de la presión intraocular. Estos fármacos pueden tener diversos efectos secundarios indeseados, lo cual invita a buscar nuevas estrategias. El objetivo de este trabajo es estudiar el uso de un ARNip (ARN pequeño de interferencia) para silenciar selectivamente los receptores adrenérgicos beta2, y comprobar si reduce la PIO (presión intraocular). Material y métodos: Se realizó instilación tópica de ARN pequeño de interferencia para los receptores adrenérgicos beta2 (ARNip, 25-250 g), midiéndose la PIO con Tonopen XL hasta nueve días consecutivos. Se comparó el efecto de dicho ARNip con componentes comerciales tales como Timoftlol, Trusopt y Xalatan, analizándose asimismo mediante microscopio si se producía cualquier cambio anatómico. Resultados: ARNip diseñado para el receptor adrenérgico beta2 indujo una reducción de la presión intraocular (PIO) de 30 ± 5%, en comparación al control (ARNip de secuencia aleatoria). Los resultados en términos de reducción de la PIO fueron similares a los encontrados utilizando componentes comerciales, aunque el tratamiento con ARNip para el receptor adrenérgico beta2 reflejó una acción hipotensora de larga duración en comparación con los fármacos comerciales. No se observaron efectos secundarios aparentes en las estructuras oculares. Conclusión: El uso de ARNip contra los receptores adrenérgicos beta2 podría aportar una estrategia terapéutica interesante para el tratamiento del glaucoma


Assuntos
Animais , Coelhos , Pressão Intraocular/genética , Glaucoma/genética , Inativação Gênica , RNA Interferente Pequeno/genética , Modelos Animais de Doenças , Glaucoma/fisiopatologia , Antagonistas de Receptores Adrenérgicos beta 2/farmacocinética , Pressão Intraocular , Glaucoma/tratamento farmacológico
10.
J. physiol. biochem ; 74(1): 57-67, feb. 2018. graf
Artigo em Inglês | IBECS | ID: ibc-178918

RESUMO

Rate-dependent repolarization (RDR) of action potential (AP) in cardiomyocyte plays a critical role in the genesis of arrhythmias and RDR in atrium has been linked with atrial fibrillation. However, detailed studies focusing on the role of RDR in rabbit atrium are scant. In this study, atrial cells were isolated from rabbit heart and rate-dependent property was explored in single atrial cell to elucidate the underlying mechanism. Our results indicated that rate-dependent prolongation was evident at the action potential duration at 20% (APD20) and 50% (APD50) repolarization but not at 90% repolarization (APD90) under control condition. Using transient outward potassium current (Ito) inhibitor 4-Aminopyridine (4-AP, 2 mM) effectively eliminated the changes in APD20 and APD50, and unmasked the rate-dependent reduction of APD90 which could be diminished by further adding L-type calcium current (ICaL) inhibitor nifedipine (30 μM). However, using the selective late sodium current (INaL) inhibitor GS-458967 (GS967, 1 μM) caused minimal effect on APD90 of atrial cells both in the absence and presence of 4-AP. In consistence with results from APs, Ito and ICaL displayed significant rate-dependent reduction because of their slow reactivation kinetics. In addition, the magnitude of INaL in rabbit atrium was so small that its rate-dependent changes were negligible. In conclusion, our study demonstrated that Ito and ICaL mediate RDR of AP in rabbit atrium, while minimal effect of INaL was seen


No disponible


Assuntos
Animais , Coelhos , Canais de Cálcio Tipo L/metabolismo , Átrios do Coração/metabolismo , Miócitos Cardíacos/metabolismo , Canais de Sódio/metabolismo , 4-Aminopiridina/farmacologia , Potenciais de Ação , Antiarrítmicos/farmacologia , Bloqueadores dos Canais de Cálcio/farmacologia , Átrios do Coração/citologia , Átrios do Coração , Miócitos Cardíacos/citologia , Miócitos Cardíacos , Nifedipino/farmacologia , Canais de Sódio/química
11.
Rev. toxicol ; 34(2): 124-129, jul.-dic. 2017. tab, graf
Artigo em Espanhol | IBECS | ID: ibc-169822

RESUMO

En el presente estudio se investigó la sensibilidad de la actividad colinesterasa del sistema nervioso del conejo (Orictolagus cuniculus) al insecticida diazinón tanto in vivo como in vitro. En el ensayo in vivo, los animales fueron expuestos oralmente a dosis únicas de diazinón (25 o 125 mg/kg) y tras 10 días fueron sacrificados para obtener el cerebro, el cerebelo y la médula espinal. En ellos se determinó la actividad colinesterasa con el fin de conocer sus valores basales en conejo (grupo control) al igual que el potencial de inhibición in vivo originado por exposición a este pesticida (grupos expuestos). Los valores basales de actividad colinesterasa, usando la acetiltiocolina como sustrato, fueron 258.5 ± 38.0, 242.4 ± 32.0 y 235.1 ± 27.2 nmol/min.mg proteínas para el cerebro, el cerebelo y la médula espinal, respectivamente. En los grupos expuestos a diazinón no se observó inhibición de la actividad colinesterasa en comparación con la actividad del grupo control. En el ensayo in vitro se expusieron homogeneizados de los tres tejidos nerviosos de conejos control a distintas concentraciones de diazinón (0.025, 0.05, 0.1, 0.2 y 0.4 mg/l). La actividad colinesterasa permaneció constantemente deprimida en relación concentración y tiempo dependiente a lo largo del periodo experimental (30 minutos, 9, 24 y 48 horas) en todos los tejidos evaluados. La Concentración Inhibitoria Media (CI50) de la actividad AChE para el diazinón se estimó en 0.154, 0.138 y 0.159 mg/l para el cerebro, el cerebelo y la médula espinal, respectivamente. Se concluye la necesidad de establecimiento de una actividad basal o de referencia en cada laboratorio cuando se pretenda utilizar esta actividad con fines diagnósticos de exposición a plaguicidas anticolinesterásicos (AU)


In the current study, the in vivo and in vitro sensitivity of nervous system cholinesterase activity to pesticide diazinon in rabbits (Orictolagus cuniculus) was investigated. In the in vivo assay, animals were orally exposed to single doses of diazinon (25 or 125 mg/kg) and after 10 days were sacrificed to obtain the brain, cerebellum and spinal cord. The cholinesterase activity in these tissues was determined to know its basal values in rabbits (control group) as well as the potential in vivo inhibition caused by exposure to this pesticide (exposed groups). The basal values of cholinesterase activity were 258.5 ± 38.0, 242.4 ± 32.0 and 235.1 ± 27.2 nmol/min.mg protein to brain, cerebellum and spinal cord,respectively, using acetylthiocholine as substrate. No inhibition of cholinesterase activity in the exposed groups compared with the control group was observed at the end of the assay. In the in vitro assay, the supernatants of the homogenized of tissues were exposed to 0.025, 0.05, 0.1, 0.2 and 0.4 mg/l of diazinon. The cholinesterase activity remained steadily depressed in a concentration and time dependent relationship throughout the experimental period (30 minutes, 9, 24 and 48 hours) in all tissues assessed. The Mean Inhibitory Concentration (IC50) of cholinesterase activity to diazinon was estimated in 0.154, 0.138 and 0.159 mg/l to brain, cerebellum and spinal cord, respectively. To determine a basal activity in each laboratory is necessary to use this enzymatic activity for diagnostic purposes of exposure to anticholinesterase pesticides (AU)


Assuntos
Animais , Inseticidas Organofosforados/efeitos adversos , Sistema Nervoso , Colinesterases , Diazinon/farmacocinética , Coelhos , Compostos Organofosforados/toxicidade , Síndromes Neurotóxicas/fisiopatologia
12.
Rev. esp. patol. torac ; 29(3): 179-187, oct. 2017. tab, ilus
Artigo em Espanhol | IBECS | ID: ibc-167914

RESUMO

Uno de los principales problemas que plantea el tratamiento quirúrgico de las lesiones traqueales es la limitación existente en la longitud del segmento que es posible resecar. Actualmente, se puede extirpar con seguridad el 50% de la tráquea como máximo. Lesiones más extensas no se pueden beneficiar de este tratamiento y es necesario utilizar técnicas alternativas, en la mayoría de los casos paliativas. Una posible solución a este problema es la interposición de algún elemento que sustituya el segmento traqueal resecado. Se ha realizado un estudio experimental en animales, sustituyendo segmentos traqueales de distinta longitud por prótesis cilíndricas de politetrafluoroetileno. Posteriormente, se ha realizado un seguimiento y sacrificio de los animales estudiando los cambios histológicos. Los resultados obtenidos muestran la posibilidad técnica de la sustitución de la vía aérea por segmentos de material protésico. En el seguimiento evolutivo de los animales, parece existir una relación directa entre la longitud del implante y la aparición de estenosis traqueal a dicho nivel, tanto en los estudios morfológicos macroscópicos como en los estudios realizados con microscopía óptica. Sin embargo, por el momento, la mortalidad perioperatoria es elevada y, si bien se puede atribuir a la curva de aprendizaje, la traslación de los resultados a una posible práctica clínica no es recomendable


One of the main problems arising from the surgical treatment of tracheal lesions is the existing limitation in the length of segment that can be resected. Currently, a maximum of 50% of the trachea can be safely removed. More extensive lesions cannot benefit from this treatment and alternative techniques must be used, which are palliative in most cases. The interposition of an element which substitutes the segment of resected trachea is a possible solution for this problem. An experimental animal study has been conducted, substituting tracheal segments varying in length with cylindrical polytetrafluoroethylene prostheses. Later, a follow-up was done and the animals were sacrificed to study histological changes. The results show the technical possibility of substituting the airway with segments of prosthetic material. In the monitoring of the animals, there seems to be a direct relationship between the length of the implant and the appearance of tracheal stenosis at the implant site, both in the macroscopic morphological studies and the studies completed with optical microscopy. However, for the time being, perioperative mortality is high and, although it can be attributed to the learning curve, applying the results to possible clinical practice is not recommended


Assuntos
Animais , Masculino , Coelhos , Estenose Traqueal/cirurgia , Estenose Traqueal/veterinária , Cuidados Paliativos/métodos , Prótese Vascular , Prótese Vascular/veterinária , Traqueia/lesões , Traqueia/cirurgia , Análise Estatística , Anastomose Cirúrgica/métodos , Anastomose Cirúrgica/veterinária , Traqueia/anatomia & histologia
13.
Med. intensiva (Madr., Ed. impr.) ; 41(3): 135-142, abr. 2017. tab, graf, ilus
Artigo em Inglês | IBECS | ID: ibc-161520

RESUMO

Objective: A study is made of the influence of preemptive hemodynamic intervention restricting fluid administration upon the development of oleic acid-induced lung injury. Design: A randomized in vivo study in rabbits was carried out. Setting: University research laboratory. Subjects: Sixteen anesthetized, mechanically ventilated rabbits. Variables: Hemodynamic measurements obtained by transesophageal Doppler signal. Respiratory mechanics computed by a least square fitting method. Lung edema assessed by the ratio of wet weight to dry weight of the right lung. Histological examination of the left lung. Interventions: Animals were randomly assigned to either the early protective lung strategy (EPLS) (n=8) or the early protective hemodynamic strategy (EPHS) (n=8). In both groups, lung injury was induced by the intravenous infusion of oleic acid (OA) (0.133mlkg−1h−1 for 2h). At the same time, the EPLS group received 15mlkg−1h−1 of Ringer lactate solution, while the EPHS group received 30mlkg−1h−1. Measurements were obtained at baseline and 1 and 2h after starting OA infusion. Results: After 2h, the cardiac index decreased in the EPLS group (p<0.05), whereas in the EPHS group it remained unchanged. Lung compliance decreased significantly only in the EPHS group (p<0.05). Lung edema was greater in the EPHS group (p<0.05). Histological damage proved similar in both groups (p=0.4). Conclusions: In this experimental model of early lung injury, lung edema progression was attenuated by preemptively restricting the administration of fluids (AU)


Objetivo: Conocer cómo influye una intervención hemodinámica preventiva basada en la restricción de fluidos sobre el desarrollo de la lesión pulmonar inducida por la administración de ácido oleico. Diseño: Estudio aleatorizado en animales vivos. Lugar: Laboratorio universitario de investigación experimental. Variables: Mecánica respiratoria (método de los mínimos cuadrados), medidas hemodinámicas (doppler esofágico), estimación del edema pulmonar (relación peso húmedo/seco del pulmón derecho) y daño histológico del pulmón izquierdo. Intervenciones: Ocho animales fueron asignados a un grupo con una estrategia protectora pulmonar (EPP), y otros 8 a otro grupo con una estrategia protectora hemodinámica (EPH). En ambos grupos la lesión pulmonar se desencadenó mediante la administración intravenosa de ácido oleico (0,133mL/kg−1/h−1 durante 2h), recibiendo simultáneamente los animales del grupo EPP 15mL/kg−1/h−1 de Ringer Lactato y los del grupo EPH 30mLKg−1h−1. Se obtuvieron medidas basales, a la hora y a las 2h. Resultados: Transcurridas las 2h de experimento el índice cardiaco permaneció estable en el grupo EPH, pero disminuyó en el grupo EPP (p<0,05). Por el contrario, la distensibilidad pulmonar disminuyó significativamente solo en el grupo EPH (p<0,05), en el cual el edema pulmonar estimado mediante la relación peso húmedo/seco del pulmón derecho fue mayor (p<0,05). El daño histológico fue similar en ambos grupos (p=0,4). Conclusiones: En este modelo experimental de lesión pulmonar aguda en fase inicial, la formación del edema pulmonar fue atenuada por la restricción preventiva en la administración de fluidos (AU)


Assuntos
Animais , Coelhos , Lesão Pulmonar Aguda/fisiopatologia , Ingestão de Líquidos/fisiologia , Edema Pulmonar/prevenção & controle , Síndrome do Desconforto Respiratório do Adulto/prevenção & controle , Ácido Oleico/efeitos adversos , Bebidas/efeitos adversos , Modelos Animais de Doenças
14.
Med. oral patol. oral cir. bucal (Internet) ; 22(2): e242-e250, mar. 2017. ilus, tab
Artigo em Inglês | IBECS | ID: ibc-161243

RESUMO

Background: The use of cold plasmas may improve the surface roughness of poly(lactic-co-glycolic) acid (PLGA) membranes, which may stimulate the adhesion of osteogenic mediators and cells, thus accelerating the biodegradation of the barriers. Moreover, the incorporation of metallic-oxide particles to the surface of these membranes may enhance their osteoinductive capacity. Therefore, the aim of this paper was to evaluate the reliability of a new PLGA membrane after being treated with oxygen plasma (PO2 ) plus silicon dioxide (SiO2 ) layers for guided bone regeneration (GBR) processes. Material and Methods: Circumferential bone defects (diameter: 11 mm; depth: 3 mm) were created on the top of eight experimentation rabbits’ skulls and were randomly covered with: (1) PLGA membranes (control), or (2) PLGA/ PO2 /SiO2 barriers. The animals were euthanized two months afterwards. A micromorphologic study was then performed using ROI (region of interest) colour analysis. Percentage of new bone formation, length of mineralised bone, concentration of osteoclasts, and intensity of ostheosynthetic activity were assessed and compared with those of the original bone tissue. The Kruskal-Wallis test was applied for between-group com a significance level of a=0.05 was considered. Results: The PLGA/PO2 /SiO2 membranes achieved the significantly highest new bone formation, length of mineralised bone, concentration of osteoclasts, and ostheosynthetic activity. The percentage of regenerated bone supplied by the new membranes was similar to that of the original bone tissue. Unlike what happened in the control group, PLGA/PO2 /SiO2 membranes predominantly showed bone layers in advanced stages of formation. Conclusions: The addition of SiO2 layers to PLGA membranes pre-treated with PO2 improves their bone-regeneration potential. Although further research is necessary to corroborate these conclusions in humans, this could be a promising strategy to rebuild the bone architecture prior to rehabilitate edentulous areas (AU)


No disponible


Assuntos
Animais , Coelhos , Regeneração Tecidual Guiada/métodos , Silicones/uso terapêutico , Plasma , Poliglactina 910/uso terapêutico , Modelos Animais de Doenças , Osso e Ossos/anormalidades , Nanocompostos/uso terapêutico
15.
Med. oral patol. oral cir. bucal (Internet) ; 22(2): e251-e257, mar. 2017. graf, ilus
Artigo em Inglês | IBECS | ID: ibc-161244

RESUMO

Background: In this study we examined the effects of two different repeated Extracorporeal Shock Waves (ESW) on the consolidation period of the distraction osteogenesis (DO) of the rabbit mandible using stereological, radiological and immunohistochemical methods. Material and Methods: DO was performed unilaterally in the mandible of 18 New Zealand rabbits (six months old, weighing between 2.5-3 kg). In the consolidation period, rabbits were divided into three groups randomly after the distraction period. The distraction zone of the mandible was received no treatment as controls (E0*2). Group 2 (E 500*2) received ESWT (twice 500 impulses at 14 kV and 0.19 mJ/mm2 energy) in the first and fourth days of the consolidation. Group 3 (E1000*2) treated with ESWT (twice 1000 impulses at 14 kV and 0.19 mJ/mm2 energy) in the first and fourth days of the consolidation period. After the sacrification, radiologically bone mineral density, new bone formation, new fibrous tissue and new vessel formation were analyzed by stereological. Results: It was found a statistically significant difference between the study groups and control group in the bone mineral density measurements and the highest value was in the E1000*2 group. In the stereological analysis, new bone formation was highest in the E1000*2 group and there was a significant difference compared to the other groups (E0*2 and E500*2) (p=0.000). The lowest connective tissue volume was found in the E500*2 and there was a significant difference compared to the other groups (E0*2 and E1000*2) (p=0.000). The volume of the new vessel was highest in the E500*2 and lowest in the E0*2 group. It was found statistically significant difference between the values of the study and control groups. Conclusions: Interestingly, we found that repetition of the 1000 impulses ESWT accelerated the consolidation, 500 impulses ESWT extended consolidation period of the DO (AU)


No disponible


Assuntos
Animais , Coelhos , Osteogênese por Distração/métodos , Ondas de Choque de Alta Energia/uso terapêutico , Osseointegração , Resultado do Tratamento , Modelos Animais de Doenças , Técnicas Estereotáxicas
16.
J. physiol. biochem ; 72(4): 711-719, dic. 2016. graf
Artigo em Inglês | IBECS | ID: ibc-168378

RESUMO

Restoration of blood flow to the ischemic myocardium is imperative to avoid demise of cardiomyocytes, but is paradoxically associated with irreversible damage to cardiac tissues due to the excessive generation of reactive oxygen species (ROS). We have previously reported that saffron, a natural antioxidant, attenuated ischemia-reperfusion (IR) injuries in vitro; however, its role in a meaningful cardiac recovery remains unknown. Here, we show that saffron supplement (oral administration for 6 weeks) reduced myocardial damage and restored cardiac function in an IR model of rabbit hearts. This was evidenced by improved left ventricle pressure, heart rate and coronary flow, and left ventricle end diastolic pressure (LVEDP) in IR hearts (isolated from rabbits pre-exposed to saffron (S/IR)). Electrophysiological recordings revealed a significant decline in both premature ventricle contraction and ventricle tachycardia/fibrillation in S/IR compared to IR hearts. This was paralleled by increased expression of the contractile proteins α-actinin and Troponin C in the myocardium of S/IR hearts. Histological examination combined to biochemical analysis indicated that hearts pre-exposed to saffron exhibited reduced infarct size, lower lipid peroxidation, with increased glutathione peroxidase activity, and oxidation of nitro blue tetrazolium (by reactive oxygen species). Furthermore, in contrast with IR hearts, saffron pretreatment induced restoration of the phosphorylation level of the survival proteins Akt and 4EBP1 and reduced activity of p38. Collectively, our data demonstrate that the natural antioxidant saffron plays a pivotal role in halting IR-associated cardiac injuries and emerges as a novel preventive tool for ischemic heart disease (AU)


No disponible


Assuntos
Animais , Masculino , Coelhos , Cardiotônicos/farmacologia , Extratos Vegetais/farmacologia , Miócitos Cardíacos , Crocus/química , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Espécies Reativas de Oxigênio/antagonistas & inibidores , Fenômenos Bioquímicos , Administração Oral , Regulação da Expressão Gênica , Glutationa Peroxidase , Velocidade do Fluxo Sanguíneo , Frequência Cardíaca , Proteínas Quinases p38 Ativadas por Mitógeno , Proteínas Proto-Oncogênicas c-akt , Técnicas de Cultura de Órgãos
17.
Angiología ; 68(2): 96-103, mar.-abr. 2016. ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-148294

RESUMO

Objetivo: Nanopartículas calcificantes (NP) se han detectado recientemente en muestras arteriales humanas y parecen estar involucradas en el proceso de calcificación. Este estudio fue diseñado para probar la hipótesis de que las NP de origen humano podrían agravar la respuesta a la lesión arterial endotelial e inducir la calcificación vascular. Métodos: La arteria carótida derecha de 24 conejos neozelandeses fue lesionada con un balón de angioplastia. Los animales fueron perfundidos por vía intravenosa con solución salina (100 ml) durante el experimento y se dividieron en 3 grupos: grupo A, control; grupo B, expuesto a NP (2 ml) obtenidas a partir de válvulas aórticas calcificadas y el grupo C, expuesto a NP (2 ml) y tratado después de la operación con atorvastatina (2,5 mg/kg/24 h). A los 30 días, los animales fueron sacrificados y se extirparon las 2 arterias carótidas, que fueron examinadas histológicamente. Análisis bioquímicos de sangre fueron realizados durante el estudio. Resultados: El área de hiperplasia intimal fue significativamente mayor en la arteria carótida derecha lesionada en comparación con la arteria carótida izquierda no operada, en todos los grupos. No hubo variación significativa en la zona medial entre los animales. Morfométricamente, la relación de íntima/media (IMR) fue significativamente mayor en las carótidas dañadas en comparación con los controles. Un aumento significativo de IMR se encontró en el grupo B (1,81 ± 0,41) en comparación con el grupo A (0,38 ± 0,59; p = 0,004) o el grupo C (0,89 ± 0,79; p = 0,035). Las diferencias entre los grupos C y A no fueron significativas (p = 0,064). Se observaron calcificaciones en 6 animales, todos los cuales habían sido expuestos a NP (4 en el grupo B, 2 en el grupo C, p = 0,027). Los niveles plasmáticos de colesterol y triglicéridos se mantuvieron estables. Conclusiones: Este estudio confirma la capacidad de las NP de origen humano de acelerar la hiperplasia y estimular la calcificación de zonas arteriales endoteliales previamente dañadas. Su administración sistémica resultó inofensiva en las arterias sanas. La atorvastatina demostró la capacidad de ralentizar este proceso (AU)


Objective: Calcifying nanoparticles (NP) have been detected recently in calcified human arterial specimens, and are involved in the process of calcification. This study was designed to test the hypothesis that human-derived NP could worsen the response to arterial endothelial injury and induce vascular calcification. Methods: The right carotid artery of 24 New Zealand rabbits was injured with an angioplasty balloon. Animals were perfused intravenously with saline (100 mL) during the experiment and divided into 3 groups: group A, control; group B, exposed to NP (2 mL) obtained from calcified aortic valves; and group C, exposed to NP (2 mL) and treated post-operatively with atorvastatin (2.5 mg/kg/24 h). At 30 days, both carotid arteries were removed and examined histologically. Blood measurements were monitored during the study. Results: The intimal hyperplasia area was significantly larger in the injured right carotid artery compared with the left un-operated carotid artery in all groups. There was no significant variation in medial area between groups. Morphometrically, the intima/media ratio (IMR) was significantly higher in damaged carotids compared with controls. A significant increase in the IMR was found in group B (1.81 ± 0.41) compared with group A (0.38 ± 0.59; P=.004) or group C (0.89 ± 0.79; P=.035). Differences between groups C and A were not significant (P=.064). Calcifications were observed in 6 animals, all of which had been exposed to NP (4 in group B, and 2 in group C, P=.027). Plasma levels of cholesterol and triglycerides remained stable. Conclusions: his study confirms the ability of systemic inoculation of human-derived NP to accelerate hyperplasia and stimulate calcification in localised areas of arteries previously submitted to endothelial damage, while it was harmless in healthy arteries. Atorvastatin was demonstrated to slow down this process (AU)


Assuntos
Animais , Masculino , Feminino , Coelhos , Nanopartículas Calcificantes/análise , Nanopartículas Calcificantes , Hiperplasia/diagnóstico , Hiperplasia/etnologia , Calcificação Vascular/induzido quimicamente , Calcificação Vascular/complicações , Calcificação Vascular/veterinária , Lesões das Artérias Carótidas/tratamento farmacológico , Lesões das Artérias Carótidas/veterinária , Aterosclerose/tratamento farmacológico , Aterosclerose/veterinária
18.
Arch. bronconeumol. (Ed. impr.) ; 52(3): 123-130, mar. 2016. ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-149910

RESUMO

Introducción: El objetivo de este estudio es evaluar l8mm frea reactividad traqueal tras la implantación de distintos stents metálicos autoexpandibles (SMAE). Material y métodos: Se utilizaron 40 conejos hembra de raza neozelandesa, que se dividieron en 4 grupos. En 3 grupos se implantaron SMAE: de acero (SA), de nitinol (NiTi) o stents liberadores de nitinol (SLF). El cuarto grupo fue el grupo de control (sin stent). Los stents se implantaron por vía percutánea bajo control fluoroscópico. Los animales se evaluaron mediante tomografía axial computarizada (TAC) multicorte y las tráqueas se extirparon para su estudio anatomopatológico (EAP). Los datos de la TAC y el EAP se analizaron estadísticamente y se correlacionaron. Resultados: El grupo que recibió SLF presentaba la mayor longitud de estenosis (20,51 ± 14,0nte a 5,84 ± 12,43 y 6,57 ± 6,54 mm en los grupos NiTi y SA, día 30; p < 0,05) y el mayor índice de formación de granulomas evidenciados mediante TAC (50% de los casos). El grupo al que se implantaron stents NiTi mostró el menor grado de estenosis (2,86 ± 6,91% frente a 11,28 ± 13,98 y 15,54 ± 25,95% en los grupos SLF y SA; p<0,05). En el estudio AP, el grupo SA presentó reactividad proliferativa intensa en comparación con los otros 2 grupos. En el grupo SLF se observó una respuesta destructiva en el 70% de animales, mientras que el stent NiTi fue el que menos reacción provocó. La TAC resultó ser superior para detectar el engrosamiento (correlación positiva de un 68,9%; p < 0,001) que para la observación de granulomas (n.s.). Conclusiones: El grupo SA desarrolló granulomas y estenosis significativas. El stent NiTi fue el que menos reacción indujo, mientras que el SLN provocó lesiones importantes que podrían estar relacionadas con la dosis de fármaco. Por consiguiente, este tipo de SLF no se recomienda para el tratamiento de la estenosis traqueobronquial


Introduction: The objective of this study was to assess tracheal reactivity after the deployment of different self-expandable metal stents (SEMS). Material and methods: Forty female New Zealand rabbits were divided into four groups. Three groups received three different SEMS: steel (ST), nitinol (NiTi), or nitinol drug-eluting stent (DES); the fourth group was the control group (no stent). Stents were deployed percutaneously under fluoroscopic guidance. Animals were assessed by multi-slice, computed tomography (CT) scans, and tracheas were collected for anatomical pathology (AP) study. Data from CT and AP were statistically analyzed and correlated. Results: The DES group had the longest stenosis (20.51 ± 14.08 mm vs. 5.84 ± 12.43 and 6.57 ± 6.54 mm in NiTi and ST, respectively, day 30; P < .05), and higher granuloma formation on CT (50% of cases). The NiTi group showed the lowest grade of stenosis (2.86 ± 6.91% vs. 11.28 ± 13.98 and 15.54 ± 25.95% in DES and ST, respectively; P<.05). The AP study revealed that the ST group developed intense proliferative reactivity compared to the other groups. In the DES group, a destructive response was observed in 70% of the animals, while the NiTi was the least reactive stent. CT was more effective in detecting wall thickening (positive correlation of 68.9%; P < .001) than granuloma (not significant). Conclusions: The ST group developed granulomas and significant stenosis. NiTi was the least reactive stent, while DES caused significant lesions that may be related to drug dosage. This type of DES stent is therefore not recommended for the treatment of tracheobronchial stenosis


Assuntos
Animais , Feminino , Coelhos , Stents Farmacológicos/efeitos adversos , Stents Farmacológicos , Stents Farmacológicos/tendências , Estenose Traqueal/complicações , Estenose Traqueal/etiologia , Estenose Traqueal/prevenção & controle , Obstrução das Vias Respiratórias/induzido quimicamente , Obstrução das Vias Respiratórias/complicações , Obstrução das Vias Respiratórias/diagnóstico , Stents/efeitos adversos , Stents/classificação , Stents/tendências , Estenose Traqueal/classificação
19.
J. physiol. biochem ; 72(1): 45-57, mar. 2016. graf, tab, ilus
Artigo em Inglês | IBECS | ID: ibc-168206

RESUMO

We examined the coordination between contractile events at different sites in the basal portion of the rabbit caecum and its associated structures that were identified by electrophysiological recordings with simultaneous one-dimensional, and a novel two-dimensional, spatiotemporal mapping technique. The findings of this work provide evidence that the caecum and proximal colon/ampulla coli act reflexly to augment colonic outflow when the caecum is distended and mass peristalsis instituted, the action of the latter overriding the inherent rhythm and direction of haustral propagation in the adjacent portion of the proximal colon but not in the terminal ileum. Further, the findings suggest that the action of the sacculus rotundus may result from its distension with chyme by ileal peristalsis and that the subsequent propagation of contraction along the basal wall of the caecum towards the colon may be augmented by this local distensión (AU)


No disponible


Assuntos
Animais , Coelhos , Ceco/fisiologia , Eletrofisiologia
20.
Arch. Soc. Esp. Oftalmol ; 91(2): 65-68, feb. 2016. ilus
Artigo em Espanhol | IBECS | ID: ibc-148062

RESUMO

OBJETIVO: Valorar histopatológicamente si existe toxicidad en la retina de conejos, posterior a la aplicación intravítrea de memantina. MÉTODOS: Se utilizaron 16 ojos de 16 conejos raza Nueva Zelanda de 3 kg, divididos en 4 grupos de 4 conejos cada uno. Al grupo A se le aplicó una dosis de 70 ng/ml de memantina intravítrea, al grupo B se le aplicó una dosis de 150 ng/ml de memantina intravítrea, al grupo C se le aplicó una dosis de 400 ng/ml de memantina intravítrea, y al grupo D se le aplicó 1 ml de solución salina balanceada. Se enucleó el ojo inyectado en la mitad de cada grupo a los 15 días, y el resto del grupo se enucleó a los 30 días posterior a la inyección. Posterior a la enucleación, cada ojo fue colocado en formaldehido al 10%. Se realizó análisis histopatológico a cada uno de los ojos enucleados. Los animales fueron tratados de acuerdo a los estatutos de la Association for Research on Vision and Ophthalmology (ARVO). RESULTADOS: Los grupos A, B y D no presentaron alteraciones histopatológicas tras 15 y 30 días de enucleación. El grupo C presentó alteración a nivel de la capa de fotorreceptores a los 15 y 30 días posterior a la enucleación. CONCLUSIONES: La memantina intravítrea a dosis de 70 mg/dl y 150 mg/dl no es tóxica a nivel estructural en la retina. La memantina a dosis de 400 mg/dl es tóxica a nivel estructural en la retina. La memantina podría ser considerada en el futuro para el tratamiento de distrofias de retina. Diversos estudios deberán ser realizados al respecto


OBJECTIVE: To histologically evaluate whether the intravitreal application of memantine produces retinal toxicity in rabbits. METHODS: A cross-sectional design, experimental, descriptive study was performed on 16 eyes of 16 New Zealand rabbits of 3 kg, divided in 4 groups of 4 rabbits. A dose of 70 ng/ml of intravitreal memantine was administered in Group A, a dose of 150 ng/ml in Group B, a dose of 400 ng/ml in Group C, and Group D received 1 ml of balanced salt solution. The injected eye of half of each group was enucleated 15 days after the injection, and the rest within 30 days after injection. Following enucleation, each eye was placed in 10% formaldehyde. Histopathological analysis was performed on all enucleated eyes. The animals were treated according to the guidelines of the Association for Research on Vision and Ophthalmology (ARVO). RESULTS: Groups A, B and D did not show any histopathological changes after their enucleation at 15 and 30 days. Group C showed changes in the photoreceptor layer after enucleation at 15 and 30 days. CONCLUSIONS: In our study, it was observed that memantine concentrations at 70 ng/ml and 150 ng/ml are safe when administered intravitreally; however, doses of 400 ng/ml produced retinal structural changes. This research should continue to assess its clinical usefulness


Assuntos
Animais , Masculino , Feminino , Coelhos , Memantina/toxicidade , Injeções Intravítreas/efeitos adversos , Enucleação Ocular/métodos , Enucleação Ocular , Enucleação Ocular/veterinária , N-Metilaspartato/análise , N-Metilaspartato/toxicidade , Corpo Vítreo , Retina , Retina/cirurgia , Mutagênese
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