¿El diseño de sistemas de anclaje mini cabestrillo realmente importa? Una comparación biomecánica entre Mini ArcTMy OphiraTM / Does the design of mini slings anchoring systems really matter? A biomechanical comparison between Mini ArcTM and OphiraTM

Introducción e hipótesis: En la actualidad un implante de cabestrillo es el tratamiento estándar para la incontinencia urinaria de esfuerzo en mujeres. Para ser eficaces requieren un sistema de anclaje adecuado. El objetivo de este estudio es comparar las características biomecánicas de los sistemas de fijación de 2 modelos de mini cabestrillos disponibles en el mercado (OphiraTM y Mini ArcTM) a través de un ensayo de tracción. Materiales y métodos: Los dispositivos de anclaje de cada cabestrillo se implantaron quirúrgicamente en la pared abdominal de 15 ratas divididas en 3 grupos de 5 animales que se organizaron de acuerdo a la fecha de la eutanasia después del implante en los días 7, 14 y 30. Las paredes abdominales de las ratas fueron extraídas en bloque, conteniendo el sistema de anclaje, y se sometieron a una prueba de resistencia tensil para medir la carga máxima y el alargamiento hasta la avulsión del dispositivo desde el tejido. Los resultados se compararon mediante la prueba «t» de Student y un punto de corte del 5% fue considerado significativo. Resultados: El sistema de fijación mini cabestrillo OphiraTM requirió una mayor carga máxima y desarrolló un tramo más largo de la avulsión del sitio implantado en todos los momentos evaluados (valor de p inferior a 0,05). Conclusión: Hubo diferencias significativas en los patrones de fijación de los sistemas de anclaje, que fueron exclusivamente relacionadas con sus diseños. El dispositivo de fijación de mini cabestrillo OphiraTM proporcionó una mejor fijación a la pared abdominal de ratas en comparación con el dispositivo Mini ArcTM, incluso en el período posterior al implante tardío

Introduction and hypothesis: Currently, a sling implant is the standard treatment for stress urinary incontinence in women. To be effective, they require an adequate anchoring system. The aim of this study is compare biomechanical features of fixation systems of two mini slings models available on the market (OphiraTM and Mini ArcTM) through a tensile test. Materials and methods: Anchoring devices of each sling were surgically implanted in abdominal wall of 15 rats divided into three groups of five animals which were arranged according to the date of post implant euthanasia on 7, 14 and 30 days. Abdominal walls of rats were extracted on bloc containing the anchoring system and were submitted to a tensile strength test to measure the maximum load and elongation until device avulsion from the tissue. The results were compared using Student test t and a 5% cut off was considered significant. Results: The OphiraTM mini sling fixation system demanded a greater maximum load and developed a longer stretch for avulsion from the implanted site at all moments evaluated (p value less than 0.05). Conclusion: There were significant differences in fixation patterns of the anchoring systems, which were exclusively related to their designs. The OphiraTM mini sling fixation device provided better fixation to the abdominal wall of rats compared to the Mini ArcTM device, even in the late post implant period

Does the design of mini slings anchoring systems really matter? A biomechanical comparison between Mini Arc™ and Ophira™. / ¿El diseño de sistemas de anclaje mini cabestrillo realmente importa? Una comparación biomecánica entre Mini Arc™y Ophira™.

INTRODUCTION AND HYPOTHESIS: Currently, a sling implant is the standard treatment for stress urinary incontinence in women. To be effective, they require an adequate anchoring system. The aim of this study is compare biomechanical features of fixation systems of two mini slings models available on the market (Ophira™ and Mini Arc™) through a tensile test. MATERIALS AND METHODS: Anchoring devices of each sling were surgically implanted in abdominal wall of 15 rats divided into three groups of five animals which were arranged according to the date of post implant euthanasia on 7, 14 and 30 days. Abdominal walls of rats were extracted on bloc containing the anchoring system and were submitted to a tensile strength test to measure the maximum load and elongation until device avulsion from the tissue. The results were compared using Student test t and a 5% cut off was considered significant. RESULTS: The Ophira™ mini sling fixation system demanded a greater maximum load and developed a longer stretch for avulsion from the implanted site at all moments evaluated (p value less than 0.05). CONCLUSION: There were significant differences in fixation patterns of the anchoring systems, which were exclusively related to their designs. The Ophira™ mini sling fixation device provided better fixation to the abdominal wall of rats compared to the Mini Arc™ device, even in the late post implant period.

Efectos biomecánicos de la inclusión de orificios facilitadores de la integración en mallas de polipropileno monofilamento: estudio experimental / Biomechanical Effects of the Inclusion of Holes to Facilitate the Integration in Monofilament Polypropylene Meshes: An Experimental Study

Objetivo: Evaluar las propiedades biomecánicas de un tipo de malla de polipropileno monofilamento utilizada para la reparación de prolapsos vaginales y los efectos de la inclusión de orificios de tamaño estandarizado, que llamamos orificios facilitadores de la integración, sobre la resistencia en la interfaz con el lecho receptor. Material y métodos: En 40 ratas Wistar, de 3 meses de edad (adultas), se implantó en la pared abdominal del lado izquierdo una malla de polipropileno monofilamento que medía 24 x 11mm sin orificios (bloque 1) y del lado derecho una malla similar con dos orificios circulares de 6mm de diámetro (bloque 2). Después de 90 días las ratas se sacrificaron y se les retiró la pared abdominal, dividiéndola en dos bloques. El estudio biomecánico se realizó con un tensiómetro de precisión con el cual se traccionó la malla en sentido uniaxial hasta que se desprendiera de la interfaz tisular. Para cuantificar en cada grupo la adherencia y elasticidad tisular se analizaron las siguientes variables: carga máxima, deflexión hasta la carga máxima, trabajo hasta la carga máxima y consistencia del material, además de carga, deflexión y trabajo en el desprendimiento de la malla. Resultados: Exceptuando la variable consistencia del material, para el resto de las variables hubo diferencia estadísticamente significativa entre ambos grupos, siendo superior en las mallas con orificios (p<0,001). La inclusión de orificios de tamaño estandarizado redujo en un 30% el peso de la malla. Conclusión: La inclusión de orificios de tamaño estandarizado en mallas de polipropileno macroporosas monofilamento, además de reducir su peso y la cantidad de material, aumentó la elasticidad y la adherencia a los tejidos al implantarse en la interfaz de la pared abdominal de ratas adultas (AU)

Objective: To evaluate the biomechanical properties of a type of monofilament polypropylene mesh used to repair vaginal prolapse, as well as the effects of the inclusion of standard size orifices, called “helper orifices,” on the interface resistance in the receiving area. Material and methods: Forty female Wistar rats, 3 month-old, received an implant of monofilament polypropylene mesh, measuring 24 x 11mm with no orifices, on left side of the abdominal wall (block 1). On the right side, a similar mesh with two circular orifices (6mm diameter) was implanted (block 2). The rats were euthanized 90 days later and their abdominal walls were removed and divided into two blocks. The biomechanical study used a precision tensiometer in which the mesh was uniaxially tensioned until it was loosened from the tissue interface. In order to determine the tissue adherence and elasticity in each group, the following variables were analyzed: maximum load; deflection at maximum load; work to maximum load; stiffness as well as load, deflection and work at detachment the mesh. Results: With the exception of stiffness, all the other variables showed statistical differences between the groups, considering that they were increased in meshes with orifices (p<0.001). The inclusion of standard size orifices reduced 30% of the mesh weigth. Conclusion: Besides reducing the weight and amount of material, the inclusion of standard size orifices in the monofilament macroporous polypropylene mesh improved the elasticity and adherence to the tissues when implanted in the interface of the abdominal wall in adult female rats (AU)

[Biomechanical effects of the inclusion of holes to facilitate the integration in monofilament polypropylene meshes: an experimental study]. / Efectos biomecánicos de la inclusión de orificios facilitadores de la integración en mallas de polipropileno monofilamento: estudio experimental.

OBJECTIVE: To evaluate the biomechanical properties of a type of monofilament polypropylene mesh used to repair vaginal prolapse, as well as the effects of the inclusion of standard size orifices, called "helper orifices," on the interface resistance in the receiving area. MATERIAL AND METHODS: Forty female Wistar rats, 3 month-old, received an implant of monofilament polypropylene mesh, measuring 24 x 11 mm with no orifices, on left side of the abdominal wall (block 1). On the right side, a similar mesh with two circular orifices (6 mm diameter) was implanted (block 2). The rats were euthanized 90 days later and their abdominal walls were removed and divided into two blocks. The biomechanical study used a precision tensiometer in which the mesh was uniaxially tensioned until it was loosened from the tissue interface. In order to determine the tissue adherence and elasticity in each group, the following variables were analyzed: maximum load; deflection at maximum load; work to maximum load; stiffness as well as load, deflection and work at detachment the mesh. RESULTS: With the exception of stiffness, all the other variables showed statistical differences between the groups, considering that they were increased in meshes with orifices (p<0.001). The inclusion of standard size orifices reduced 30% of the mesh weigth. CONCLUSION: Besides reducing the weight and amount of material, the inclusion of standard size orifices in the monofilament macroporous polypropylene mesh improved the elasticity and adherence to the tissues when implanted in the interface of the abdominal wall in adult female rats.

Un nuevo modelo experimental de inducción de cistitis intersticial mediante estrés oxidativo empleando instilación vesical de un gel donante de óxido nítrico / A new experimental model for inducing interstitial cystitis by oxidative stress using bladder instillation of a nitric oxide donor gel

Objetivo: La principal finalidad de este estudio es el desarrollo de un nuevo modelo experimental para la inducción de cistitis intersticial (CI) mediante la instilación vesical de una solución polimérica que contiene el S-nitrosoglutatión donante de óxido nítrico (GSNO), y su comparación con la cistitis intersticial experimental inducida por instilación vesical de protamina y cloruro potásico. Material y métodos: Para la consecución de nuestro objetivo utilizamos 40 hembras de rata Wistar divididas en cuatro grupos: a) solución salina + GSNO; b) solución salina + solución polimérica (sin GNSO); c) sulfato de protamina + KCl; y d) sulfato de protamina + GSNO. Se realizó bien una aplicación a las ratas (5 animales), bien 3 aplicaciones (5 animales) de la sustancia correspondiente mediante instilación vesical, y al cabo de 6 días (5 animales) o 9 días (5 animales)se les practicó la eutanasia y se les extrajeron las vejigas para su evaluación macroscópica y estudio histológico. Resultados: En términos de evaluación macroscópica observamos edema e hiperemia de la mucosa en dos (22%) de los animales del grupo 1, en 0 (0%) de los del grupo 2, en 10 (100%) de los del 3 y en 5 (50%) de los animales del grupo 4. En el grupo de protamina + KCl y en solución salina + GSNO se observaron efectos similares en la pared vesical. Los animales del grupo 2 (solución salina + polimérica) mostraban congestión vascular, bastante menos significativa que en el resto después de 9 días de instilaciones (p = 0,0035). Se observó un aumento de la fibrosis tras las instilaciones en los grupos 3 y 4 a los 6 días (p = 0,3781) y a los 9 días (p = 0,0459) respectivamente, en comparación con los controles (grupo 2). En todos los grupos aparecía un infiltrado de neutrófilos con intensidad variable a los 6 días de las instilaciones (p = 0,7277). Al cabo de 9 días se producía una regresión del infiltrado, y sin evidencias de reacción neutrofílica marcada en todos los grupos (p = 0,2301). Conclusión: La respuesta inflamatoria a la instilación vesical de una solución acuosa de Snitrosoglutatión fue muy parecida a la inducida por la instilación vesical de protamina y KCl. La instilación de una solución acuosa de GSNO puede considerarse un nuevo modelo para la inducción experimental de cistitis intersticial (AU)

Purpose: The aim of this study is to develop a new experimental model of inducing interstitial cystitis (IC) through vesical instillation of a polymeric solution containing the NO donor S-nitrousglutathione (GSNO) and to compare it to the experimental interstitial cystitis inducedby vesical instillation of protamine and potassium chloride. Material and method: For that purpose 40 female Wistar rats were used, divided in four groups: 1. saline solution + GSNO; 2. saline solution + polymeric solution (without GNSO); 3. Protamine sulphate + KCl; 4. protamine sulphate + GSNO. The rats received one application (5 animals) or 3 applications (5 animals) of the corresponding substance through intravesical instillation, and after 6 days (5 animals) or 9 days (5 animals) they were euthanized and their bladders were removed for macroscopic evaluation and histological study. Results: In the macroscopic evaluation we observed edema and hyperemia of the mucosa in2 (22%) of the animals in group 1, in 0 (0%) of the animals in group 2, in 10 (100%) of the animals in group 3, and in 5 (50%) of the animals in group 4. In the protamine + KCl group and in saline + GSNO similar effects were observed on the bladder wall. The animals in group2 (saline + polymeric) showed vascular congestion, significantly smaller than the rest after9 days instillations (p = 0.0035). Significant increased fibrosis was observed after instillations in groups 3 and 4, after 6 days (p = 0.3781) and 9 days (p = 0.0459) respectively, when compared to control (group 2). All groups presented neutrophilic infiltrate of variable intensity 6 days after instillations (p = 0.7277). After 9 days, there was a regression of the infiltrate, with no evidence of accentuated neutrophilic reaction in all the groups (p = 0.2301). Conclusion: The inflammatory response to bladder instillation of an aqueous solution of Snitrousglutathione was very similar to that induced by bladder instillation of protamine and KCl. Instillation of an aqueous solution of GSNO can be considered a new model for experimental induction of interstitial cystitis (AU)

[A new experimental model for inducing interstitial cystitis by oxidative stress using bladder instillation of a nitric oxide donor gel]. / Un nuevo modelo experimental de inducción de cistitis intersticial mediante estrés oxidativo empleando instilación vesical de un gel donante de óxido nítrico.

PURPOSE: The aim of this study is to develop a new experimental model of inducing interstitial cystitis (IC) through vesical instillation of a polymeric solution containing the NO donor S-nitrousglutathione (GSNO) and to compare it to the experimental interstitial cystitis induced by vesical instillation of protamine and potassium chloride. MATERIAL AND METHOD: For that purpose 40 female Wistar rats were used, divided in four groups: 1. saline solution + GSNO; 2. saline solution + polymeric solution (without GNSO); 3. protamine sulphate + KCl; 4. protamine sulphate + GSNO. The rats received one application (5 animals) or 3 applications (5 animals) of the corresponding substance through intravesical instillation, and after 6 days (5 animals) or 9 days (5 animals) they were euthanized and their bladders were removed for macroscopic evaluation and histological study. RESULTS: In the macroscopic evaluation we observed edema and hyperemia of the mucosa in 2 (22%) of the animals in group 1, in 0 (0%) of the animals in group 2, in 10 (100%) of the animals in group 3, and in 5 (50%) of the animals in group 4. In the protamine + KCl group and in saline + GSNO similar effects were observed on the bladder wall. The animals in group 2 (saline + polymeric) showed vascular congestion, significantly smaller than the rest after 9 days instillations (p=0.0035). Significant increased fibrosis was observed after instillations in groups 3 and 4, after 6 days (p=0.3781) and 9 days (p=0.0459) respectively, when compared to control (group 2). All groups presented neutrophilic infiltrate of variable intensity 6 days after instillations (p=0.7277). After 9 days, there was a regression of the infiltrate, with no evidence of accentuated neutrophilic reaction in all the groups (p=0.2301). CONCLUSION: The inflammatory response to bladder instillation of an aqueous solution of S-nitrousglutathione was very similar to that induced by bladder instillation of protamine and KCl. Instillation of an aqueous solution of GSNO can be considered a new model for experimental induction of interstitial cystitis.

Actin-associated proteins in ameloblast differentiation.

Focal contacts are systems of adherens junctions of the cell-extracellular matrix type, which allow the transfer of fundamental signals from the extracellular matrix to nuclear compartments, capable of regulating adhesion, proliferation, migration and differentiation of cells. Recently, many authors have concentrated their attention on epitheliomesenchymal interactions which guide organogenesis of dental germ, identifying numerous growth and differentiation factors and having the inner enamel epithelial cells of the enamel organ as a target. Given that the two cellular compartments in their tooth germ are separated by a basal membrane and by an extracellular matrix, which touches it, we wanted to evaluate the presence of focal contacts through the identification of talin and vinculin, proteins of the actin-associated protein complex. In this study we utilized the hemimandibles of young Wistar rats and we extracted the related odontogenic tooth organs present at their apical end. Specimens are processed with antibody against vinculin and talin. Results show that these junctional system proteins are present at the apical poles of both cellular compartments suggesting that putative epithelial-mesenchymal interactions, other than marker molecules, may use focal contacts as a system for transmission of signals.

The ameloblast movement in rat incisor. L.M., S.E.M. and C.L.S.M. study.

The internal epithelium of enamel organ and the below enamel surface during growth of the lower incisor, were examinated in ten Wistar rat 12-27 weeks old and weighing between 150/200 gr, by means of immuno histochemical, light and scanning electron microscopy techniques. Our specimens indicate that during the outer enamel secretion the anti-actin positivity goes from distal terminal web to infra nuclear region of cell body. The results of the present study do not support the active movement hypothesis, conversely they support the Warshawsky (1992) hypothesis, i.e. the distal terminal web permits the maintenance and the assembling of ameloblasts during enamel growth. Hence we do agree with Osborn (1970) who reported that, during secretion, ameloblasts move passively in response to secretory forces.