Evaluation of apoptosis and osteopontin expression in osteocytes exposed to orthodontic forces of different magnitudes.

The in vivo response of osteocytes to different force magnitudes soon after they are applied remains to be elucidated. The aim of this study was to examine the early effects of applying a very light (LF: 0,16 N) and a very strong (SF: 2,26 N) orthodontic force during one hour on apoptosis and osteopontin (OPN) expression on alveolar bone osteocytes, in rats. Results: LF: compared to the control group, they showed a significant increase in OPN expression, and a significant decrease in the number of TUNELpositive osteocytes. SF: compared to the control group, they showed a significant increase in OPN expression and a significant decrease in the number of TUNELpositive osteocytes. Our results show that osteocytes respond very early to the application of tension and pressure forces of different magnitudes, and application of forces decreases the number of apoptotic osteocytes and increases OPN expression. These results allow concluding that osteocytes activate rapidly when subjected to locally applied forces, whether these forces be pressure or tension, light or strong forces.

Hasta el momento no se ha dilucidado la respuesta temprana in vivo de los osteocitos a la aplicación de fuerzas de diferentes magnitudes sobre el hueso. El objetivo de este estudio fue examinar la respuesta temprana de la aplicación de una fuerza ortodóncica muy liviana (FL: 0,16 N) y muy fuerte (FF: 2,26 N) durante una hora sobre la expresión de apoptosis y osteopontina (OPN) en los osteocitos del hueso alveolar, en ratas. Resultados: FL: en comparación con el grupo control, mostraron un aumento significativo en la expresión de OPN y una disminución significativa en el número de osteocitos TUNELpositivos. FF: en comparación con el grupo control, mostraron un aumento significativo en la expresión de OPN y una disminución signi ficativa en el número de osteocitos TUNELpositivos. Nuestros resultados muestran que los osteocitos responden muy temprano a la aplicación de fuerzas de tensión y presión de diferentes magnitudes, y la aplicación de fuerzas disminuye el número de osteocitos apoptóticos y aumenta la expresión de OPN. Estos resultados permiten concluir que los osteocitos se activan rápidamente cuando se los somete a fuerzas aplicadas localmente, ya sean estas fuerzas de presión o tensión, livianas o fuertes.

Evaluation of apoptosis and osteopontin expression in osteocytes exposed to orthodontic forces of different magnitudes

The in vivo response of osteocytes to different force magnitudes soon after they are applied remains to be elucidated. The aim of this study was to examine the early effects of applying a very light (LF: 0,16 N) and a very strong (SF: 2,26 N) orthodontic force during one hour on apoptosis and osteopontin (OPN) expression on alveolar bone osteocytes, in rats. Results: LF: compared to the control group, they showed a significant increase in OPN expression, and a significant decrease in the number of TUNELpositive osteocytes. SF: compared to the control group, they showed a significant increase in OPN expression and a significant decrease in the number of TUNELpositive osteocytes. Our results show that osteocytes respond very early to the application of tension and pressure forces of different magnitudes, and application of forces decreases the number of apoptotic osteocytes and increases OPN expression. These results allow concluding that osteocytes activate rapidly when subjected to locally applied forces, whether these forces be pressure or tension, light or strong forces. Grants: UBACyT 200201301002270 BA and School of Dentistry, University of Buenos Aires (AU)

Hasta el momento no se ha dilucidado la respuesta temprana in vivo de los osteocitos a la aplicación de fuerzas de diferentes magnitudes sobre el hueso. El objetivo de este estudio fue examinar la respuesta temprana de la aplicación de una fuerza ortodóncica muy liviana (FL: 0,16 N) y muy fuerte (FF: 2,26 N) durante una hora sobre la expresión de apoptosis y osteopontina (OPN) en los osteocitos del hueso alveolar, en ratas. Resultados: FL: en comparación con el grupo control, mostraron un aumento significativo en la expresión de OPN y una disminución significativa en el número de osteocitos TUNELpositivos. FF: en comparación con el grupo control, mostraron un aumento significativo en la expresión de OPN y una disminución signi ficativa en el número de osteocitos TUNELpositivos. Nuestros resultados muestran que los osteocitos responden muy temprano a la aplicación de fuerzas de tensión y presión de diferentes magnitudes, y la aplicación de fuerzas disminuye el número de osteocitos apoptóticos y aumenta la expresión de OPN. Estos resultados permiten concluir que los osteocitos se activan rápidamente cuando se los somete a fuerzas aplicadas localmente, ya sean estas fuerzas de presión o tensión, livianas o fuertes (AU)

An experimental model of disuse in the alveolar rat bone: A histomorphometrical study.

Lack of mechanical stimulation is known to cause disuse osteopenia in bones. However, experimental models for disuse osteopenia on bones other than jawbones are not applicable to jawbones. The little available information in this field has been applied to the study of overeruption of teeth lacking antagonists. However, the absence of an antagonist in the opposite jaw means that there is no stimulation by occlusion. Our hypothesis is that the lack of stimulation due to the absence of teeth causes disuse osteopenia in the interradicular bone of the antagonist teeth. Our aim was to develop a model of disuse osteopenia due to the absence of occlusal forces. We used male Wistar rats with 215-230 g body weight, divided into 2 groups: one absolute control group (C) and one experimental group in which the three right lower molars were extracted (E). The left side of the jaw in the experimental group was used as a paired control (PC). The animals were euthanized 7 days after extraction. The jaws were placed in occlusion, fastened and fixed in 10% formalin. The heads were cut in half and radiographs made of both jaws. The upper jaws were processed histologically. After decalcification, bucco-palatine oriented sections were cut at the level of the mesial root and distal roots of the first upper molars. On the radiographs, the distance from the tip of the cusp on the first upper molar to the antagonist edentulous ridge (DA) was measured. On the microphotographs, the following parameters were measured: passive eruption degree (PED), height of periodontal ligament at the level of the furcation (HPL) and interradicular bone volume (BVI). The data were compared statistically using ANOVA and Bonferroni's post-hoc test, considering p<0.05 as statistically significant. DA in experimental animals was 0.34}0.048 mm. PED in experimental animals was significantly greater than in the control groups, both for the buccal plate and for the palatal plate. HPL showed no significant difference between groups. BVI was significantly lower in the experimental group than in the control group. The results showed that the model used produces a condition of disuse osteopenia, shown by the statistically significant reduction in interradicular bone volume. The use of this model at different experimental times will enable the evaluation of cell responses in periodontal tissues, particularly bone tissue, e.g. to compare them to known responses such as the application of orthodontic forces.

Ultrastructure of the surface of dental enamel with molar incisor hypomineralization (MIH) with and without acid etching.

The aim of the present work was to analyze the ultrastructure and mineral composition of the surface of the enamel on a molar with MIH, with and without acid etching. A permanent tooth without clinical MIH lesions (control) and a tooth with clinical diagnosis of mild and moderate MIH, with indication for extraction, were processed with and without acid etching (H3PO4 37%, 20") for observation with scanning electron microscope (SEM) ZEISS (Supra 40) and mineral composition analysis with an EDS detector (Oxford Instruments). The control enamel showed normal prismatic surface and etching pattern. The clinically healthy enamel on the tooth with MIH revealed partial loss of prismatic pattern. The mild lesion was porous with occasional cracks. The moderate lesion was more porous, with larger cracks and many scales. The mineral composition of the affected surfaces had lower Ca and P content and higher O and C. On the tooth with MIH, even on normal looking enamel, the demineralization does not correspond to an etching pattern, and exhibits exposure of crystals with rods with rounded ends and less demineralization in the inter-prismatic spaces. Acid etching increased the presence of cracks and deep pores in the adamantine structure of the enamel with lesion. In moderate lesions, the mineral composition had higher content of Ca, P and Cl. Enamel with MIH, even on clinically intact adamantine surfaces, shows severe alterations in the ultrastructure and changes in ionic composition, which affect the acid etching pattern and may interfere with adhesion.

Effectiveness of preventive and corrective surgical intervention on hip disorders in severe cerebral palsy: a systematic review.

PURPOSE: This review presents an overview of the effectiveness of preventive and corrective surgical interventions to treat hip displacement in patients with severe cerebral palsy (CP). METHOD: A systematic literature search was applied to identify studies concerning surgical procedures in hip(sub)luxations in severe CP (GMFCS IV and V). A qualitative analysis and a best evidence synthesis were performed for soft tissue surgery and osteotomies. RESULTS: The literature search identified 15 studies, all of which were observational. Five studies involved soft tissue surgery and 10 involved osteotomies. Only one study involving soft tissue surgery was of sufficient quality. Nine of the 10 studies involving osteotomies were of sufficient quality, including a total of 189 patients. The mean MP (migration percentage) at follow-up ranged from 6 to 29%. No relationship could be established between the effect of the surgical procedure and the patients' age or the duration of follow-up. The percentage of patients reporting pain decreased from 81% preoperatively to 5% at follow-up. Twenty-five percent had complications such as osteoarthritis, ulcers or fractures. CONCLUSIONS: There is insufficient evidence for the effectiveness of soft tissue surgery to stabilize the hip, due to insufficient quality of the retrospective observational studies. This review shows indicative findings (provided by consistent, statistically significant findings on outcome and/or process measures in at least two Observational Studies with sufficient quality) for an effect of bony surgery in stabilizing the hip. Timing of the procedure remains an issue. Multicenter trials could shed further light on this complicated subject.

An experimental model of disuse in the alveolar rat bone: A histomorphometrical study

Lack of mechanical stimulation is known to cause disuse osteopenia in bones. However, experimental models for disuse osteopenia on bones other than jawbones are not applicable to jawbones. The little available information in this field has been applied to the study of overeruption of teeth lacking antagonists. However, the absence of an antagonist in the opposite jaw means that there is no stimulation by occlusion. Our hypothesis is that the lack of stimulation due to the absence of teeth causes disuse osteopenia in the interradicular bone of the antagonist teeth. Our aim was to develop a model of disuse osteopenia due to the absence of occlusal forces. We used male Wistar rats with 215-230 g body weight, divided into 2 groups: one absolute control group (C) and one experimental group in which the three right lower molars were extracted (E). The left side of the jaw in the experimental group was used as a paired control (PC). The animals were euthanized 7 days after extraction. The jaws were placed in occlusion, fastened and fixed in 10% formalin. The heads were cut in half and radiographs made of both jaws. The upper jaws were processed histologically. After decalcification, bucco-palatine oriented sections were cut at the level of the mesial root and distal roots of the first upper molars. On the radiographs, the distance from the tip of the cusp on the first upper molar to the antagonist edentulous ridge (DA) was measured. On the microphotographs, the following parameters were measured: passive eruption degree (PED), height of periodontal ligament at the level of the furcation (HPL) and interradicular bone volume (BVI). The data were compared statistically using ANOVA and Bonferroni's post-hoc test, considering p<0.05 as statistically significant. DA in experimental animals was 0.34}0.048 mm. PED in experimental animals was significantly greater than in the control groups, both for the buccal plate and for the palatal plate. HPL showed no significant difference between groups. BVI was significantly lower in the experimental group than in the control group. The results showed that the model used produces a condition of disuse osteopenia, shown by the statistically significant reduction in interradicular bone volume. The use of this model at different experimental times will enable the evaluation of cell responses in periodontal tissues, particularly bone tissue, e.g. to compare them to known responses such as the application of orthodontic forces.

Se sabe que la falta de estimulo mecanico produce un cuadro de osteopenia por desuso en huesos de la economia. Los modelos experimentales de osteopenia por desuso utilizados en otros huesos no son aplicables a los huesos maxilares. La escasa informacion que existe en este campo se aplico al estudio de la sobreerupcion de dientes sin antagonista. Sin embargo, la ausencia de antagonista en el maxilar opuesto hace que falte el estimulo de la oclusion. Por tal razon, nuestra hipotesis es que la falta de estimulo por ausencia de piezas dentarias provoca un cuadro de osteopenia por desuso en el hueso interradicular de los dientes antagonistas. Nuestro objetivo fue poner a punto un modelo de osteopenia por desuso debido a la ausencia de fuerzas oclusales. Se emplearon ratas Wistar machos de entre 215-230 g de peso corporal divididas en 2 grupos, un grupo control absoluto (C) y un grupo experimental al que se le extrajeron los tres molares inferiores derechos (E). El lado izquierdo del maxilar del grupo experimental, fue utilizado como control apareado (CA). A los 7 dias de efectuadas las extracciones se realizo la eutanasia de los animales. Los maxilares se colocaron en oclusion, se precintaron y asi ubicados se fijaron en formol 10%. Se dividieron las hemicabezas y tomaron radiografias de ambos maxilares siendo procesados histologicamente los maxilares superiores. Luego de la descalcificacion se obtuvieron cortes orientados en sentido buco-palatino a nivel de la raiz mesial y de las raices distales de los 1o molares superiores. Sobre las radiografias se midio la distancia desde el vertice cuspideo del 1o molar superior al reborde antagonista desdentado (DA), y sobre microfotografias se midieron los siguientes parametros: grado de erupcion pasiva (GE), altura del ligamento periodontal a nivel de la furcacion (ALP) y volumen oseo interradicular (VOI). Los datos se compararon estadisticamente mediante el test ANOVA y prueba post hoc de Bonferroni, considerando una p<0,05 como estadisticamente significativa. La DA en los animales experimentales fue de 0,34}0,048 mm. La GE en los animales experimentales fue significativamente mayor que en los grupos control, tanto a nivel de la tabla vestibular como de la tabla palatina. La ALP no mostro diferencias significativas entre los grupos. El VOi fue significativamente menor en el grupo experimental con respecto a los controles. Los resultados mostraron que el modelo empleado logra una condicion de osteopenia por desuso manifestada por la disminucion del volumen oseo interradicular. La utilizacion de este modelo de desuso a diferentes tiempos experimentales permitira evaluar las respuestas celulares de los tejidos periodontales, especial - mente del tejido oseo, permitiendo por ejemplo, compararlas con respuestas conocidas como la aplicacion de fuerzas ortodoncicas.

Ultrastructure of the surface of dental enamel with molar incisor hypomineralization (MIH) with and without acid etching / Ultraestructura de la superficie del esmalte dental con hipomineralización molar incisiva (mih) con y sin grabado ácido

El objetivo del presente trabajo fue analizar la ultraestructura y composición mineral de la superficie del esmalte de un molar con MIH, con y sin tratamiento de grabado ácido. Se analizaron una pieza dentaria permanente sin lesiones clínicas de MIH (controles) y una pieza con diagnóstico clínico de MIH leve y moderada, con indicación de extracción con y sin grabado acido (H3PO4 37 por ciento, 20”). Fueron procesadas para su observación con microscopio electrónico de barrido (SEM) ZEISS (Supra 40) y análisis de la composición mineral con detector EDS (Oxford Instruments). El esmalte del control mostró superficie prismática y patrón de grabado normales. El esmalte clínicamente sano en la pieza con MIH reveló una pérdida parcial del patrón prismático. La lesión leve se presentó porosa con ocasional esgrietas. La moderada presentó mayor porosidad, con grietas de mayor tamaño y presencia de gran cantidad de escamas. La composición mineral de las superficies afectadas mostró menor contenido de Ca y P y aumento de O y C. En la muestra con MIH, inclusive con aspecto normal, las desmineralizaciones no responden a un patrón de grabado, mostrando exposición de cristales con redondeamiento en los extremos de las varillas y menor desmineralización en los espacios interprismáticos. El grabado ácido incrementó la aparición de grietas y profundos poros en la estructura adamantina del esmalte con lesión. La composición mineral mostró en las lesiones moderadas una mayor disminución del contenido de Ca, P y Cl.El esmalte con MIH, inclusive en la superficie adamantina clínicamente intacta, presenta severas alteraciones ultraestructurales y cambios en la composición iónica afectando el patrónde grabado ácido, que podría interferir con los mecanismos de adhesión.

The aim of the present work was to analyze the ultrastructure and mineral composition of the surface of the enamel on amolar with MIH, with and without acid etching. A permanent tooth without clinical MIH lesions (control) and a tooth with clinical diagnosis of mild and moderate MIH, with indication for extraction, were processed with and without acid etching(H3PO437%, 20”) for observation with scanning electron microscope (SEM) ZEISS (Supra 40) and mineral composition analysis with an EDS detector (Oxford Instruments). The control enamel showed normal prismatic surface and etching pattern. The clinically health y enamel on the tooth with MIH revealed partial loss of prismatic pattern. The mild lesion wasporous with occasional cracks. The moderate lesion was moreporous, with larger cracks and many scales. The mineral composition of the affected surfaces had lower Ca and Pcontent and higher O and C. On the tooth with MIH, even on normal looking enamel, the demineralization does not correspond to an etching pattern, and exhibits exposure of crystals with rods with rounded ends and less demineralization in the inter-prismatic spaces. Acid etching increased the presence of cracks and deep pores in the adamantine structure of the enamel with lesion. In moderate lesions, the mineral composition had higher content of Ca, P and Cl. Enamel with MIH, even on clinically intact adamantine surfaces, shows severe alterations in the ultrastructure and changes in ionic composition, which affect the acid etching pattern and may interfere with adhesion.

Identification and characterization of mutant clones with enhanced propagation rates from phage-displayed peptide libraries.

A target-unrelated peptide (TUP) can arise in phage display selection experiments as a result of a propagation advantage exhibited by the phage clone displaying the peptide. We previously characterized HAIYPRH, from the M13-based Ph.D.-7 phage display library, as a propagation-related TUP resulting from a G→A mutation in the Shine-Dalgarno sequence of gene II. This mutant was shown to propagate in Escherichia coli at a dramatically faster rate than phage bearing the wild-type Shine-Dalgarno sequence. We now report 27 additional fast-propagating clones displaying 24 different peptides and carrying 14 unique mutations. Most of these mutations are found either in or upstream of the gene II Shine-Dalgarno sequence, but still within the mRNA transcript of gene II. All 27 clones propagate at significantly higher rates than normal library phage, most within experimental error of wild-type M13 propagation, suggesting that mutations arise to compensate for the reduced virulence caused by the insertion of a lacZα cassette proximal to the replication origin of the phage used to construct the library. We also describe an efficient and convenient assay to diagnose propagation-related TUPS among peptide sequences selected by phage display.

Palliative hip surgery in severe cerebral palsy: a systematic review.

We performed a systematic review of the results of palliative hip surgery in severe cerebral palsy. Individuals with severe cerebral palsy frequently suffer from pain and other impairments because of dislocation or malformation of the hips. When preventive or reconstructive surgery fails, palliative intervention is performed. A number of salvage interventions have been described. We found articles on resection surgery of the femoral head, arthrodesis of the hip joint, and total hip replacement. The published literature does not clearly favor one procedure over the others. The resection arthroplasty technique developed by Castle is reported to yield the best results and fewer complications, and seems to eventually lead to a good outcome.

Histomorphometric study and three-dimensional reconstruction of the osteocyte lacuno-canalicular network one hour after applying tensile and compressive forces.

The occurrence of very early morphological changes in the osteocyte lacuno-canalicular network following application of tensile and/or compressive forces remains unknown to date. Thus, the aim of this study was to perform a morphological and morphometric evaluation of the changes in the three-dimensional structure of the lacuno-canalicular network and the osteocyte network of alveolar bone that take place very early after applying tensile and compressive forces in vivo, conducting static histomorphometry on bright-field microscopy and confocal laser scanning microscopy images. Our results showed that both the tensile and compressive forces induced early changes in osteocytes and their lacunae, which manifested as an increase in lacunar volume and changes in lacunar shape and orientation. An increase in canalicular width and a decrease in the width and an increase in the length of cytoplasmic processes were also observed. The morphological changes in the lacuno-canalicular and osteocyte networks that occur in vivo very early after application of tensile and compressive forces would be an indication of an increase in permeability within the system. Thus, both compressive and tensile forces would cause fluid displacement very soon after being applied; the latter would in turn rapidly activate alveolar bone osteocytes, enhancing transmission of the signals to the entire osteocyte network and the effector cells located at the bone surface.

The lacuno-canalicular system (LCS) and osteocyte network of alveolar bone by confocal laser scanning microscopy (CLSM).

The osteocyte lacuno-canalicular system (OLCS) is a large network intercommunicating the lacunae and canaliculi which contain the osteocytes and their cytoplasmic processes within the mineralized bone matrix. The vitality and functioning of the osteocytes and cytoplasmic processes depend upon this intercommunication. To date, the 3-dimensional features of OLCS in the alveolar bone have not been studied; therefore the aim of this study was to use confocal scanning microscopy to do so. Samples of alveolar bone from male Wistar rats were fixed in buffer formalin and stained with basic fuchsin to visualize the lacuno-canalicular system. In decalcified samples of the same bone, the actin was labeled using fluorescent phallotoxin to visualize the osteocyte network. The samples were observed at the level of the mesial root of the first upper molar in bucco-palatal direction using a confocal laser scanning microscope. The results showed that in the area near the inner aspect (bundle bone) of the buccal plate, the osteocyte lacunae are oval-shaped and relatively uniform in size, aligned parallel to each other and with their major axes parallel to the periodontal bone surface, and the osteocytes are oval-shaped, with their main axes perpendicular to the periodontal bone surface, and the cytoplasmic processes irradiate in all directions. In the area near the inner aspect (bundle bone) of the palatal plate, the osteocyte lacunae are rounded, have different sizes and their orientation does not follow any specific pattern, and the osteocyte bodies have major axes parallel to the periodontal surface, a larger number of cytoplasmic processes, and run in a straighter direction than in the buccal plate. These results will contribute to the understanding of the changes that may occur in OLCS microarchitecture as a result of a pathological process, surgical technique or force applied to the alveolar bone.

The lacuno-canalicular system (LCS) and osteocyte network of alveolar bone by confocal laser scanning microscopy (CLSM) / Características del sistema lacuno-canalicular (lcs) y la red osteocitaria del hueso alveolar observadas por microscopía láser de barrido confocal (clsm)

El sistema lacuno-canalicularosteocitario (OLCS) comprende una amplia red de intercomunicación entre las lagunas y loscanalículos que contienen a los osteocitos y sus procesos citoplasmáticos dentro de la matriz ósea mineralizada, de lo que depende su vitalidad y funcionamiento. Hasta el momento no se han estudiado las características tridimensionales delOLCS en el hueso alveolar por lo que el objetivo del presente trabajo fue de eterminarla por microscopía de barrido co nfocal. Muestras de hueso alveolar de ratas Wistar machos, luego fijadas en formol buffer fueron teñidas con fucsina básicapar a visualizar el sistema lacuno-canalicular y a muestrasdescalcificadas del mismo hueso mediante una falotoxinafluorescente se les marcó la actina para visualizar la redosteocitaria. Las muestras se observaron a nivel de la raízmesial del primer molar superior en sentido buco-palatinocon un microscopio láser de barrido confocal. Los resultadosmostraron que en la zona aledaña a la cortical periodontal dela tabla ósea vestibular las lagunas osteocitarias presentanforma ovalada y tamaño relativamente uniforme, alinéandoseparalelas entre sí y con su eje mayor paralelo a la superficieósea periodontal en tanto que los osteocitos, de forma ovalada,presentan su eje mayor orientado perpendicularmente a dicha superficie y con los procesos citoplasmáticos irradiándose en todos los sentidos del espacio. En la zona aledaña ala cortical periodontal de la tabla ósea palatina las lagunas osteocitarias se presentan de forma redondeada y tienen distintos tamaños, sin seguir un patrón de orientación específico, y los cuerpos osteocitarios presentan su eje mayor paralelo a una dirección más recta que en la tabla vestibular.(AU)

The lacuno-canalicular system (LCS) and osteocyte network of alveolar bone by confocal laser scanning microscopy (CLSM) / Características del sistema lacuno-canalicular (lcs) y la red osteocitaria del hueso alveolar observadas por microscopía láser de barrido confocal (clsm)

El sistema lacuno-canalicularosteocitario (OLCS) comprende una amplia red de intercomunicación entre las lagunas y loscanalículos que contienen a los osteocitos y sus procesos citoplasmáticos dentro de la matriz ósea mineralizada, de lo que depende su vitalidad y funcionamiento. Hasta el momento no se han estudiado las características tridimensionales delOLCS en el hueso alveolar por lo que el objetivo del presente trabajo fue de eterminarla por microscopía de barrido co nfocal. Muestras de hueso alveolar de ratas Wistar machos, luego fijadas en formol buffer fueron teñidas con fucsina básicapar a visualizar el sistema lacuno-canalicular y a muestrasdescalcificadas del mismo hueso mediante una falotoxinafluorescente se les marcó la actina para visualizar la redosteocitaria. Las muestras se observaron a nivel de la raízmesial del primer molar superior en sentido buco-palatinocon un microscopio láser de barrido confocal. Los resultadosmostraron que en la zona aledaña a la cortical periodontal dela tabla ósea vestibular las lagunas osteocitarias presentanforma ovalada y tamaño relativamente uniforme, alinéandoseparalelas entre sí y con su eje mayor paralelo a la superficieósea periodontal en tanto que los osteocitos, de forma ovalada,presentan su eje mayor orientado perpendicularmente a dicha superficie y con los procesos citoplasmáticos irradiándose en todos los sentidos del espacio. En la zona aledaña ala cortical periodontal de la tabla ósea palatina las lagunas osteocitarias se presentan de forma redondeada y tienen distintos tamaños, sin seguir un patrón de orientación específico, y los cuerpos osteocitarios presentan su eje mayor paralelo a una dirección más recta que en la tabla vestibular.

Comparison of surgical outcomes between canaloplasty and trabeculectomy at 12 months' follow-up.

PURPOSE: To compare operative outcomes of patients after canaloplasty and trabeculectomy through 12 months' follow-up. DESIGN: Retrospective, nonrandomized, comparative case series. PARTICIPANTS: We included 33 eyes of 33 patients who underwent canaloplasty and 46 eyes of 46 patients who underwent trabeculectomy with 12 months' of postoperative follow-up. METHODS: Patients with open-angle glaucoma who underwent either canaloplasty or trabeculectomy with mitomycin C to control the intraocular pressure (IOP) between January 2007 and December 2008 were included. All surgeries were performed by a single surgeon (R.S.A.). MAIN OUTCOME MEASURES: Change in IOP, visual acuity (VA), postoperative medications, failure based on IOP (>18 or <4 mmHg at 1 year) or second operative procedure (any eye requiring reoperation) and complication rates at 12 months. RESULTS: There were no differences in demographics, previous surgery, or preoperative and postoperative VA between the groups. The mean percentage reduction in IOP from preoperative values at 12 months after surgery was 32% (± 22%) for the canaloplasty group compared with 43% (± 28%) for the trabeculectomy group (P = 0.072, Student t test). The median reduction in the number of medications at 12 months' follow-up was 3 in the trabeculectomy group and 2 in the canaloplasty group (P = 0.064). A higher percentage of patients treated with canaloplasty than trabeculectomy (36% vs. 20%) required postoperative medications, although this did not attain significance (P = 0.12). Failure based on IOP (IOP >18 or <4 mmHg at 12 months) was 12.1% (4/33 patients) for the canaloplasty group and 4.3% (2/46 patients) for the trabeculectomy group (P = 0.23, Fisher exact test). There was no difference in surgical failure rates between the canaloplasty (n = 5; 15%) and trabeculectomy (n = 5; 11%) groups (P = 0.74). CONCLUSIONS: Canaloplasty and trabeculectomy both achieved significant reduction in IOP at 12 months. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Effects of roasting and boiling of quinoa, kiwicha and kañiwa on composition and availability of minerals in vitro.

BACKGROUND: Andean indigenous crops such as quinoa (Chenopodium quinoa), kiwicha (Amaranthus caudatus) and kañiwa (Chenopodium pallidicaule) seeds are good sources of minerals (calcium and iron). Little is known, however, about mineral bioavailability in these grains. Thus the aim of the present study was to determine the iron, calcium and zinc potential availability in raw, roasted and boiled quinoa, kañiwa and kiwicha seeds. Potential availability was estimated by dialyzability. RESULTS: These seeds are good sources of phenolic compounds and kañiwa of dietary fiber. Their calcium, zinc and iron content is higher than in common cereals. In general, roasting did not significantly affect mineral dialyzability. Conversely, in boiled grains there was an increase in dialyzability of zinc and, in the case of kañiwa, also in iron and calcium dialyzability. CONCLUSION: Taking into account the high content of minerals in Andean grains, the potential contribution of these minerals would not differ considerably from that of wheat flour. Further studies are required to research the effect of extrusion on mineral availability in Andean grains.

Parental fever attitude and management: influence of parental ethnicity and child's age.

OBJECTIVE: The objective was to study parental fever management and attitude toward fever from the perspective of the child's ethnicity and age. PATIENTS AND SETTING: Children with fever presenting at the pediatric emergency department (PED) of the Erasmus MC-Sophia Children's Hospital, Rotterdam, the Netherlands, in the period from February 2002 to March 2004. DESIGN: Prospective observational. MAIN OUTCOME MEASURES: Parental fever attitude and management assessed by a questionnaire. RESULTS: Two hundred eleven children with fever (median age, 1.2 years; interquartile range, 0.7-2.0 years) were included, of whom 108 (55%) were boys. One hundred fourteen children (54%) were self-referrals at the PED. Accompanying symptoms were reported in 95% (50% had > or = 3); median temperature measured at PED was 39.5 degrees C (interquartile range, 38.9 degrees C-40.8 degrees C). One hundred fifty-five parents (74%) had used antipyretics to reduce fever, and 155 parents (74%) were worried about fever and its possible complications. Differences between Dutch and non-Dutch ethnicities were seen in temperature-reducing techniques, self-referral, and parental anxiety of fever and its complications. Age did not influence parental fever attitude and management. CONCLUSIONS: For most children in our population, the use of antipyretics was justified, as the majority of our children visiting the PED for an acute febrile episode are young infants, in particular with a high degree of fever and accompanying symptoms. We confirm and extend previous findings of ethnicity influencing parental fever management.

Revisión de la clasificación de los estilos de aprendizaje

El presente trabajo tienen como objetivo profundizar la noción del constructo estilo de aprendizaje y de los modelos más frecuentemente mencionados en la literatura, con el propósito de proporcionar bases teóricas contemporáneas, para facilitar la aplicación de dicho concepto en el aula. Se partirá de la definición propuesta por múltiples autores y posteriormente un ordenamiento del estilo de aprendizaje en función de la clasificación propuesta por Grigorenko y Stemberg y en mayor profundidad la propuesta de Curry con el modelo "ONION", se hará una breve descripción de los diferentes instrumentos de evaluación ideadas según el estilo de aprendizaje. El estudio permite analizar las diferentes propuestas de estilos de aprendizaje halladas y usadas comúnmente en la literatura concluyéndose que cada estudiante tiene características distintivas que definen los ejes de su proceso de aprendizaje; para el diagnóstico de los estilos de aprendizaje existen numerosos instrumentos que deben utilizarse en forma variada, debemos ayudarlos a conocer y mejorar sus propios estilos de aprendizaje, cada docente deberá ser capaz de adaptar su estilo de enseñanza a los estilos de aprendizaje de tal forma de no afectar negativamente el rendimiento del mismo.

Revisión de la clasificación de los estilos de aprendizaje

El presente trabajo tienen como objetivo profundizar la noción del constructo estilo de aprendizaje y de los modelos más frecuentemente mencionados en la literatura, con el propósito de proporcionar bases teóricas contemporáneas, para facilitar la aplicación de dicho concepto en el aula. Se partirá de la definición propuesta por múltiples autores y posteriormente un ordenamiento del estilo de aprendizaje en función de la clasificación propuesta por Grigorenko y Stemberg y en mayor profundidad la propuesta de Curry con el modelo "ONION", se hará una breve descripción de los diferentes instrumentos de evaluación ideadas según el estilo de aprendizaje. El estudio permite analizar las diferentes propuestas de estilos de aprendizaje halladas y usadas comúnmente en la literatura concluyéndose que cada estudiante tiene características distintivas que definen los ejes de su proceso de aprendizaje; para el diagnóstico de los estilos de aprendizaje existen numerosos instrumentos que deben utilizarse en forma variada, debemos ayudarlos a conocer y mejorar sus propios estilos de aprendizaje, cada docente deberá ser capaz de adaptar su estilo de enseñanza a los estilos de aprendizaje de tal forma de no afectar negativamente el rendimiento del mismo.