Estudio del déficit de habituación en pacientes con migraña episódica mediante reflejo de parpadeo nociceptivo / Habituation deficit study in patients with episodic migraine thru nociceptive blink reflex

Introducción. La falta de habituación es el fenómeno neurofisiológico interictal más reproducible en la migraña episódica. El objetivo de este estudio es evaluar el fenómeno de habituación mediante el estudio del reflejo de parpadeo nociceptivo en pacientes con migraña episódica. Sujetos y métodosEstudio observacional transversal de casos y controles. Los pacientes con migraña episódica fueron seleccionados de manera consecutiva, estudiados durante la fase interictal. Se estudió el reflejo de parpadeo nociceptivo, y se realizó un estudio comparativo de simetría, análisis de distancias euclidianas y valoración de prolongación de latencias entre bloques de estimulación. Resultados Se incluyó a 31 pacientes y 16 controles sanos, con una edad media de 32,25 y 32,35 años, respectivamente. Los controles mostraron simetría izquierda-derecha. Las distancias euclidiana y Manhattan demostraron que las medias de las latencias por bloque de los grupos son diferentes y se incrementan según el número de bloques que se comparen. Las medias de las latencias de los bloques no difieren significativamente en el grupo de pacientes con migraña, a diferencia del grupo de sanos. Conclusión Se observó un déficit de habituación en la fase intercrítica en pacientes con migraña episódica frente a controles, medido por la ausencia de prolongación de latencias en el reflejo de parpadeo nociceptivo. (AU)

Introduction. Lack of habituation is the most reproducible interictal neurophysiological phenomenon in episodic migraine. The aim of this study is to evaluate the habituation phenomenon by examining the nociceptive blink reflex in patients with episodic migraine. Subjects and methods. We conducted a cross-sectional observational case-control study. Patients with episodic migraine were selected consecutively and studied during the interictal phase. The nociceptive blink reflex was examined and a study was conducted comparing symmetry, analysis of the Euclidean distances and assessment of latency prolongation between stimulation blocks. Results. Thirty-one patients and 16 healthy controls were included, their mean ages being 32.25 and 32.35 years, respectively. The controls displayed left-right symmetry. The Euclidean and Manhattan distances showed that the means of the block latencies of the groups are different and increase according to the number of blocks being compared. The means of the block latencies do not differ significantly in the migraine patient group, in contrast to what is seen in the healthy group. Conclusion. Habituation deficit was observed in the interictal phase in patients with episodic migraine compared to controls, as measured by the absence of latency prolongation in the nociceptive blink reflex. (AU)

[Habituation deficit study in patients with episodic migraine thru nociceptive blink reflex]. / Estudio del déficit de habituación en pacientes con migraña episódica mediante reflejo de parpadeo nociceptivo.

INTRODUCTION: Lack of habituation is the most reproducible interictal neurophysiological phenomenon in episodic migraine. The aim of this study is to evaluate the habituation phenomenon by examining the nociceptive blink reflex in patients with episodic migraine. SUBJECTS AND METHODS: We conducted a cross-sectional observational case-control study. Patients with episodic migraine were selected consecutively and studied during the interictal phase. The nociceptive blink reflex was examined and a study was conducted comparing symmetry, analysis of the Euclidean distances and assessment of latency prolongation between stimulation blocks. RESULTS: Thirty-one patients and 16 healthy controls were included, their mean ages being 32.25 and 32.35 years, respectively. The controls displayed left-right symmetry. The Euclidean and Manhattan distances showed that the means of the block latencies of the groups are different and increase according to the number of blocks being compared. The means of the block latencies do not differ significantly in the migraine patient group, in contrast to what is seen in the healthy group. CONCLUSION: Habituation deficit was observed in the interictal phase in patients with episodic migraine compared to controls, as measured by the absence of latency prolongation in the nociceptive blink reflex.

TITLE: Estudio del déficit de habituación en pacientes con migraña episódica mediante reflejo de parpadeo nociceptivo.Introducción. La falta de habituación es el fenómeno neurofisiológico interictal más reproducible en la migraña episódica. El objetivo de este estudio es evaluar el fenómeno de habituación mediante el estudio del reflejo de parpadeo nociceptivo en pacientes con migraña episódica. Sujetos y métodos. Estudio observacional transversal de casos y controles. Los pacientes con migraña episódica fueron seleccionados de manera consecutiva, estudiados durante la fase interictal. Se estudió el reflejo de parpadeo nociceptivo, y se realizó un estudio comparativo de simetría, análisis de distancias euclidianas y valoración de prolongación de latencias entre bloques de estimulación. Resultados. Se incluyó a 31 pacientes y 16 controles sanos, con una edad media de 32,25 y 32,35 años, respectivamente. Los controles mostraron simetría izquierda-derecha. Las distancias euclidiana y Manhattan demostraron que las medias de las latencias por bloque de los grupos son diferentes y se incrementan según el número de bloques que se comparen. Las medias de las latencias de los bloques no difieren significativamente en el grupo de pacientes con migraña, a diferencia del grupo de sanos. Conclusión. Se observó un déficit de habituación en la fase intercrítica en pacientes con migraña episódica frente a controles, medido por la ausencia de prolongación de latencias en el reflejo de parpadeo nociceptivo.

Regulation of Tau protein phosphorylation by glucosamine-induced O-GlcNAcylation as a neuroprotective mechanism in a brain ischemia-reperfusion model.

Purpose:Tau hyperphosphorylation is a modification frequently observed after brain ischemia which has been related to the aggregation of this protein, with subsequent cytoskeletal damage, and cellular toxicity. The present study tests the hypothesis of using glucosamine, an agent that increases protein O-GlcNAcylation, to decrease the levels of phosphorylation in Tau during ischemia-reperfusion.Material and methods: Transient focal ischemia was artificially induced in male Wistar rats by occlusion of the middle cerebral artery (MCAO) with an intraluminal monofilament. A single dose of intraperitoneal glucosamine of 200 mg/kg diluted in normal saline (SSN) was administered 60 min before ischemia. Histological brain sections were processed using indirect immunofluorescence with primary antibodies (anti-O-GlcNAc and anti pTau-ser 396). The Image J software was used to calculate the immunofluorescence signal intensity.Results: The phosphorylation of Tau at the serine residue 396 had a significant decrease with the administration of glucosamine during ischemia-reperfusion compared with the administration of placebo.Conclusions: These results show that glucosamine can reduce the phosphorylation levels of Tau in rodents subjected to ischemia and cerebral reperfusion, which implies a neuroprotective role of glucosamine.

Implementación del método simplificado Apnealink™Air® por médicos de atención primaria para el diagnóstico del síndrome de apnea-hipopnea durante el sueño / Implementation of simplified diagnostic method Apnealink™Air® to diagnose sleep apnea by general practioners of primary care

Objetivo: Valorar la interpretación de ApnealinkTM® (AL) por médicos de atención primaria (MAP), y la alcanzada mediante poligrafía respiratoria (PGR) en la Unidad de Sueño Hospitalaria (USH) en pacientes con alta probabilidad de síndrome de apnea e hipopnea del sueño (SAHS). Métodos: Se recogen aleatoriamente, durante tres meses, pacientes seleccionados en USH para estudio mediante PGR, con elevada probabilidad de SAHS que aceptaron repetir estudio mediante AL. La USH corregía la PGR según normativa SEPAR; el MAP corregía el AL y planteaba manejo. Se analizaron los pacientes con estudios válidos(tiempo registro ≥ 240 min) para ambos dispositivos, comparándose resultados. Se consideró el estudio AL automático y corregido, considerando un índice de desaturación de oxihemoglobina (ODI) al 4% (ODI 4%), (AL 4%) y al 3% (ODI 3%), (AL 3%). Cuando ODI 4% era ≥ 12/h, se estableció diagnóstico SAHS moderado/grave, suponiendo un IAH ≥ 15/h. Para interpretar AL con ODI 3% y tratamiento, se siguieron criterios SEPAR. Se compararon los resultados para las mismas variables del AL frente a PGR. Resultados: Se incluyeron 43 pacientes válidos para AL, 45 para PGR y 41 válidos para ambos estudios. El estudio AL 4% mostró 27 (62,8%) positivos (OR 5,5, p < 0,05), que el AL 3% corroboró con IAH ≥ 15/h. La PGR detectó 19 (42,2%) con IAH ≥ 15/h; el AL 3% detectó 31 (72%). El análisis del AL 4% y AL 3% comparado con PGR no mostró diferencias de diagnóstico o manejo. Se compararon los resultados para las mismas variables del AL frente a PGR.Conclusiones: Existe equivalencia entre las decisiones del MAP y la USH. El AL sería un buen método diagnóstico de SAHS en atención primaria, en pacientes seleccionados con alta probabilidad de SAHS (AU)

Objectives: To assess diagnosis and therapeutic decisions-making by General Practitioners (GP) using ApnealinkTM® (AL) in patients with high suspicion of obstructive sleep apnea (OSA), in comparison with conclusions of Hospital Sleep Unit (HSU) specialists based on home respiratory polygraphy (PGR) results. Methods: This study involved patients previously selected by HSU for sleep testing by PGR. After it, patients were offered to complete AL test. PGR was checked at HSU; AL was checked by hemoglobin desaturation index of 4% (4% ODI), (4% AL) and 3% (3% ODI) patients with positive test to proceed with CPAP; and those with negative test for further testing. Automatically adjusted 4% AL, was considered valid as it was demonstrated to be equivalent to manual AL. Results were compared by automatically adjusted 3%AL against PGR results. Results: 48 patients were collected. 43 had AL valid test, 45 had PGR valid study, and 41 had both valid test. 27 patients (62,8%) had positive 4% AL (OR 5,51, p < 0,05), that showed AHI ≥ 15/h at 3% AL test; and 19 patients (42,2%) had a positive PGR test. 31 (72%) patients had a positive 3% AL. AL had shown to be a good screening method of SAHS. Conclusions: There is equivalence between the decisions of GP and HSU. AL is a good diagnostic tool and screening method for OSA in primary care when it is used in patients with high suspicion of moderate-severe OSA (AU)

[Implementation of simplified diagnostic method Apnealink™Air® to diagnose sleep apnea by general practioners of primary care]. / Implementación del método simplificado Apnealink™Air® por médicos de atención primaria para el diagnóstico del síndrome de apnea-hipopnea durante el sueño.

OBJECTIVES: To assess diagnosis and therapeutic decisions-making by General Practitioners (GP) using ApnealinkTM® (AL) in patients with high suspicion of obstructive sleep apnea (OSA), in comparison with conclusions of Hospital Sleep Unit (HSU) specialists based on home respiratory polygraphy (PGR) results. METHODS: This study involved patients previously selected by HSU for sleep testing by PGR. After it, patients were offered to complete AL test. PGR was checked at HSU; AL was checked by hemoglobin desaturation index of 4% (4% ODI), (4% AL) and 3% (3% ODI) patients with positive test to proceed with CPAP; and those with negative test for further testing. Automatically adjusted 4% AL, was considered valid as it was demonstrated to be equivalent to manual AL. Results were compared by automatically adjusted 3%AL against PGR results. RESULTS: 48 patients were collected. 43 had AL valid test, 45 had PGR valid study, and 41 had both valid test. 27 patients (62,8%) had positive 4% AL (OR 5,51, p < 0,05), that showed AHI ≥ 15/h at 3% AL test; and 19 patients (42,2%) had a positive PGR test. 31 (72%) patients had a positive 3% AL. AL had shown to be a good screening method of SAHS. CONCLUSIONS: There is equivalence between the decisions of GP and HSU. AL is a good diagnostic tool and screening method for OSA in primary care when it is used in patients with high suspicion of moderate-severe OSA.

Understanding quantum emitters in plasmonic nanocavities with conformal transformation: Purcell enhancement and forces.

Nanogaps supporting cavity plasmonic modes with unprecedented small mode volume are attractive platforms for tailoring the properties of light-matter interactions at the nanoscale and revealing new physics. Hitherto, there is a concerning lack of analytical solutions to divide the complex interactions into their different underlying mechanisms to gain a better understanding that can foster enhanced designs. Bowtie apertures are viewed as an effective and appealing nanocavity and are studied here within the analytical frame of conformal transformation. We show how the non-radiative Purcell enhancement of a quantum emitter within the bowtie nanocavity depends strongly not only on the geometry of the nanocavity, but also on the position and orientation of the emitter. For a 20 nm diameter (∅ 20 nm) bowtie nanocavity, we report a change of up to two orders of magnitude in the maximum non-radiative Purcell enhancement and a shift in its peak wavelength from green to infra-red. The changes are tracked down to the overlap between the emitter field and the gap plasmon mode field distribution. This analysis also enables us to understand the self-induced trapping potential of a colloidal quantum dot inside the nanocavity. Since transformations can be cascaded, the technique introduced in this work can also be applied to a wide range of nanocavities found in the literature.

[Face protective patches do not reduce facial pressure ulcers in a simulated model of non-invasive ventilation]. / Uso de parches protectores faciales no reduce la presión facial en un modelo simulado de ventilación mecánica no invasiva.

Noninvasive ventilation (NIV) frequently involves the development of facial pressure ulcers (FPU). Its prevention considers the empirical use of protective patches between skin and mask, in order to reduce the pressure exerted by it. OBJECTIVES: To evaluate the effect of protective patches on the pressure exerted by the facial mask, and its impact on the programmed ventilatory parameters. METHOD: Bilevel NIV simulated model using full face mask in phantom with a physiological airway (ALS PRO +) in supine position. Forehead, chin and cheekbones pressure were measured using 3 types of standard protective patches versus a control group using pressure sensors (Interlinks Electronics®). The values obtained with the protective patches-mask model were evaluated in the programmed variables maximum inspiratory flow (MIF)), expired tidal volume (Vte) and positive inspiratory pressure (IPAP), with Trilogy 100 ventilator, Respironics®. The programming and recording of the variables was carried out in 8 opportunities in each group by independent operators. RESULTS: There was no decrease in facial pressure with any of the protective patches compared to the control group. Moltopren increased facial pressure at all support points (p < 0.001), increased leakage, it decreased MIF, Vte and IPAP (p < 0.001). Hydrocolloid patches increased facial pressure only in the left cheekbone, increased leakage and decreased MIF. Polyurethane patches did not produce changes in facial pressure or ventilatory variables. CONCLUSION: The use of protective patches of moltopren, hydrocolloid and polyurethane transparent did not contribute to the decrease of the facial pressure. A deleterious effect of the moltopren and hydrocolloid patches was observed on the administration of ventilatory variables, concluding that the non-use of the protective patches allowed a better administration of the programmed parameters.

Uso de parches protectores faciales no reduce la presión facial en un modelo simulado de ventilación mecánica no invasiva / Face protective patches do not reduce facial pressure ulcers in a simulated model of non-invasive ventilation

La ventilación mecánica no invasiva (VMNI) tiene como complicación frecuente el desarrollo de úlceras faciales por presión (UPP). Su prevención considera el uso empírico de parches protectores entre piel y mascarilla, para disminuir la presión ejercida por ésta. Objetivos: Evaluar el efecto de los parches protectores sobre la presión ejercida por la mascarilla facial, y su impacto en los parámetros ventilatorios programados. Método: Modelo simulado de VMNI binivelada usando mascarilla facial total en fantoma con vía aérea fisiológica (ALS PRO+) en posición supina. Se midió la presión en frente, mentón y pómulos, usando 3 tipos de parches protectores de uso habitual versus un grupo control, utilizando sensores de presión (Interlinks Electronics®). Se evaluaron los valores obtenidos con el modelo de mascarilla-parches protectores en las variables programadas flujo máximo inspiratorio (FMI), volumen corriente espirado (Vte) y presión positiva inspiratoria (IPAP), con ventilador Trilogy 100, Respironics®. La programación y registro de las variables fue efectuada en 8 oportunidades en cada grupo por operadores independientes. Resultados: No se observó disminución de la presión facial con ninguno de los parches protectores respecto al grupo control. Moltoprén aumentó la presión facial en todos los puntos de apoyo (p < 0,001), aumentó fuga, disminuyó FMI, Vte e IPAP (p < 0,001). Parches de hidrocoloide aumentaron la presión facial sólo en pómulo izquierdo, aumentaron la fuga y disminuyeron FMI. Parches de poliuretano no generaron cambios en la presión facial ni en variables ventilatorias. Conclusión: El uso de parches protectores de moltoprén, hidrocoloide y poliuretano transparente no contribuyó a la disminución de la presión facial. Se observó un efecto deletéreo de los parches de moltoprén e hidrocoloide sobre la administración de variables ventilatorias, concluyendo que el no uso de los parches protectores permitió una mejor administración de los parámetros programados.

Noninvasive ventilation (NIV) frequently involves the development of facial pressure ulcers (FPU). Its prevention considers the empirical use of protective patches between skin and mask, in order to reduce the pressure exerted by it. Objectives: To evaluate the effect of protective patches on the pressure exerted by the facial mask, and its impact on the programmed ventilatory parameters. Method: Bilevel NIV simulated model using full face mask in phantom with a physiological airway (ALS PRO +) in supine position. Forehead, chin and cheekbones pressure were measured using 3 types of standard protective patches versus a control group using pressure sensors (Interlinks Electronics®). The values obtained with the protective patches-mask model were evaluated in the programmed variables maximum inspiratory flow (MIF)), expired tidal volume (Vte) and positive inspiratory pressure (IPAP), with Trilogy 100 ventilator, Respironics®. The programming and recording of the variables was carried out in 8 opportunities in each group by independent operators. Results: There was no decrease in facial pressure with any of the protective patches compared to the control group. Moltopren increased facial pressure at all support points (p < 0.001), increased leakage, it decreased MIF, Vte and IPAP (p < 0.001). Hydrocolloid patches increased facial pressure only in the left cheekbone, increased leakage and decreased MIF. Polyurethane patches did not produce changes in facial pressure or ventilatory variables. Conclusion: The use of protective patches of moltopren, hydrocolloid and polyurethane transparent did not contribute to the decrease of the facial pressure. A deleterious effect of the moltopren and hydrocolloid patches was observed on the administration of ventilatory variables, concluding that the non-use of the protective patches allowed a better administration of the programmed parameters.

Sectional matrix: Step-by-step directions for their clinical use.

The sectional matrix is the best way to achieve a strong contact point in Class II restorations with composite resin in the posterior dental sector. The pre-wedging is essential to get a separation between teeth which avoid the matrix deformation during its insertion. This article describes the clinical technique for restoring Class II cavities using a sectional matrix.

First freshwater coralline alga and the role of local features in a major biome transition.

Coralline red algae are significant components of sea bottom and up to now considered as exclusively marine species. Here we present the first coralline alga from a freshwater environment, found in the Cetina River (Adriatic Sea watershed). The alga is fully adapted to freshwater, as attested by reproductive structures, sporelings, and an inability to survive brackish conditions. Morphological and molecular phylogenetic analyses reveal the species belongs to Pneophyllum and is described as P. cetinaensis sp. nov. The marine-freshwater transition most probably occurred during the last glaciation. The brackish-water ancestor was preadapted to osmotic stress and rapid changes in water salinity and temperature. The particular characteristics of the karst Cetina River, such as hard water enriched with dissolved calcium carbonate and a pH similar to the marine environment, favoured colonization of the river by a marine species. The upstream advance and dispersal is facilitated by exceptionally pronounced zoochory by freshwater gastropods. Pneophyllum cetinaensis defies the paradigm of Corallinales as an exclusively marine group.

Diabetes mellitus secundario a episodio único de pancreatitis aguda: caso clínico y revisión de la literatura / Diabetes mellitus after a single episode of acute pancreatitis: report of one case

Diabetes mellitus secondary to pancreatic diseases is classified as type 3C and it can appear after a single episode of acute pancreatitis. We report a 25 years old female with a family history of diabetes. She was admitted to the hospital due to an acute pancreatitis of biliary origin. She received parenteral nutrition and required up to 82 units of insulin per day to maintain blood glucose levels. A CT scan showed a pseudocyst. A percutaneous drainage, followed by necrotic tissue debridement were performed. She was discharged two months after admission requiring insulin to maintain metabolic control.

Localized photonic jets from flat, three-dimensional dielectric cuboids in the reflection mode.

A photonic jet (a terajet at terahertz frequencies) commonly denotes a specific, spatially localized region in the near field on the front side of a dielectric particle with a diameter comparable with the wavelength illuminated by a plane wave on its back side (i.e., the jet emerges from the shadow surface of a dielectric particle). In this Letter, the formation of a photonic jet is demonstrated using the recently proposed three-dimensional (3D) dielectric cuboids working in the "reflection" mode when the specific, spatially localized region is localized in the direction of the incident wavefront. The results of the simulations based on the Finite Integration Technique are discussed. All dimensions are given in wavelength units so that all results can be scaled to any frequency of interest, including optical frequencies, thus simplifying the fabrication process compared with spherical dielectrics. The results presented here may be of interest for novel applications, including microscopy techniques and sensors.

Use of a Copper Band to Make Resin Cores in Endodontically Treated Teeth Lacking Coronal Structure.

This article describes the use of a copper band as a matrix to build up resin cores in endodontically treated teeth that have a partially subgingival margin. The copper band is adjusted to the contour of the remaining dental structure and extends beyond the margins to ensure complete isolation in order to provide a matrix to fabricate a core.

Exploiting the dispersion of the double-negative-index fishnet metamaterial to create a broadband low-profile metallic lens.

Metamaterial lenses with close values of permittivity and permeability usually display low reflection losses at the expense of narrow single frequency operation. Here, a broadband low-profile lens is designed by exploiting the dispersion of a fishnet metamaterial together with the zoning technique. The lens operates in a broadband regime from 54 GHz to 58 GHz, representing a fractional bandwidth ~7%, and outperforms Silicon lenses between 54 and 55.5 GHz. This broadband operation is demonstrated by a systematic analysis comprising Huygens-Fresnel analytical method, full-wave numerical simulations and experimental measurements at millimeter waves. For demonstrative purposes, a detailed study of the lens operation at two frequencies is done for the most important lens parameters (focal length, depth of focus, resolution, radiation diagram). Experimental results demonstrate diffraction-limited ~0.5λ transverse resolution, in agreement with analytical and numerical calculations. In a lens antenna configuration, a directivity as high as 16.6 dBi is achieved. The different focal lengths implemented into a single lens could be potentially used for realizing the front end of a non-mechanical zoom millimeter-wave imaging system.

Multifrequency focusing and wide angular scanning of terajets.

In the past, it has been demonstrated that it is possible to produce terajets with high resolution at its focus using 3D dielectric cuboids under plane-wave illumination. Here, a systematic study of the harmonic and angular response of terajets using cuboids is performed. Mutifrequency focusing is demonstrated at the fundamental frequency and two higher frequency harmonics showing an intensity enhancement of ∼10, ∼18, and ∼14 for each case. This capability to use 3D dielectric cuboids to produce terajets at the fundamental frequency and first harmonic is experimentally evaluated at sub-THz frequencies, with good agreement with numerical results. Moreover, a robust angular response is demonstrated numerically and experimentally showing that the intensity at the focal position is maintained in a wide angular range (from 0° to 45°), demonstrating the capability to work as a wide scanning terajet-focusing lens. The results here presented may be scaled at different frequency bands such as optical frequencies and may be used in microscopy techniques and sensors.

Experimental in vitro infection of rat osteoblasts with measles virus stimulates osteogenic differentiation.

In this work we characterized the infection of a primary culture of rat osteoblastic lineage cells (OBCs) with measles virus (MeV) and the effect of infection on cell differentiation and maturation. Infection of OBCs with MeV led to high titers of infectivity released early after infection. Also, analysis of mRNAs corresponding to osteogenic differentiation markers like alkaline phosphatase (ALP), bone sialo-protein (BSP) and bone morphogenetic proteins (BMPs) 1-4-5-7 in OBCs revealed higher values (2-75-fold of increment) for infected cells in comparison with uninfected controls. Differentiation of OBCs in osteogenic medium prior to infection influenced the level of stimulation induced by MeV. Furthermore, treatment of OBCs with Ly294002, a PI3K/AKT inhibitor, increased viral titers, whereas treatment with 10µM or 100µM ATPγS diminished MeV multiplication. In addition, increments of osteogenic differentiation markers induced by MeV infection were not modified either by treatment with Ly294002 or ATPγS. These data provide the first evidence demonstrating that MeV can infect osteoblasts in vitro leading to osteoblastic differentiation, a key feature in bone pathogenic processes like otosclerosis.

Randomized clinical trial on the efficacy and safety of four professional at-home tooth whitening gels.

OBJECTIVE: This randomized clinical trial evaluated the efficacy and safety of four gels of differing concentrations used for at-home vital bleaching. MATERIALS AND METHODS: Ninety-six volunteers participated in the study and were divided into four groups of 24 individuals. A gel of differing concentration was used for each group: 10% and 15% carbamide peroxide and 7.5% and 9.5% hydrogen peroxide. The patients used the whitening agent in a tray without reservoirs for one hour per day for two weeks. The measurement of the change in tooth color was made by two observers in the maxillary right central incisor and with a colorimeter in both upper central incisors and canines, using the CIE L*a*b* and CIE L*C*h* values. Sensitivity was evaluated by the participants on a scale with values as follows: 0 = absent, 1 = minor, 2 = moderate, 3 = considerable, 4 = severe. RESULTS: At the baseline, the observers noted darker colors than the colorimeter (p<0.01), and there were differences between incisors and canines in all the CIE L*a*b* and CIE L*C*h* values (p<0.001). In all of the groups and for all of the CIE L*a*b* and CIE L*C*h* parameters, there were color changes in the assessments made in the four maxillary teeth after treatment (p<0.001). There were no differences in ΔL* and ΔE* between the groups. The number of patients who experienced sensitivity and the intensity of the sensitivity were not significant. CONCLUSIONS: There were no differences in the degree of whitening among the different products. With all of the products there was an increase in L*, a decrease in chromatic intensity (C*), and an increase in the value (tone) or hue (h*).

Compromiso intestinal por quemadura eléctrica de alto voltaje. Caso clínico / Intestinal involvement by high voltage electrical burn. Case report

Las quemaduras son una de las causas más importantes de discapacidad y mortalidad en todo el mundo. En las producidas por electricidad de alto voltaje, las manifestaciones sistémicas más frecuentes son la insuficiencia renal y las arritmias. La lesión visceral secundaria a una quemadura eléctrica es infrecuente y su tratamiento quirúrgico constituye un desafío. En este artículo presentamos el caso clínico de un paciente con quemadura eléctrica de alto voltaje con compromiso de la pared abdominal y lesión intestinal secundaria (AU)

Burns are one of the leading causes of disability and mortality worldwide. In high-voltage electrical burns most common systemic manifestations are renal failure and arrhythmias. Visceral injury secondary to electrical burn is rare and its surgical management is challenging. This article presents a case of a patient with highvoltage electrical burn with involvement of the abdominal wall and secondary bowel injury (AU)

Prognostic factors for amputation in severe burn patients.

INTRODUCTION: Amputation is a rare procedure among burned patients. However, it has significant physical and psychological consequences which impact quality of life. OBJECTIVE: To study the incidence, etiology and prognostic factors associated with amputation among burned patients in Chile. METHODS: Cohort study of patients admitted to the Reference Burn Center of Chile from 2006 to 2011. Association of demographic, event and injury variables with the likelihood of amputation were evaluated by using multivariable analysis. RESULTS: Amputation incidence was 5.8% in 1090 admitted patients. Male amputee patients were significantly more frequent (p=0.01), with more electrical and high voltage burns (p<0.01) and had greater frequency of impaired consciousness (p=0.03). Multivariable analysis identified electrical burns (OR 13.7; 95% CI 6.7-28.1) and impaired consciousness (OR 2.8; 95% CI 1.4-5.7) as prognostic factors for amputation. CONCLUSION: Amputation is a low incidence procedure among burned patients. Patients who underwent amputations are frequently at working age. Patients with high-voltage electrical burns and impaired consciousness are more likely to undergo amputation. Since these are highly incapacitating injuries, it is very important to implement preventive measures.