Tumor fibroso solitario (TFS) parafaríngeo: reporte de caso y revisión de literatura / Parapharyngeal solitary fibrous tumor (SFT): case report and literature review

El espacio parafaríngeo es una región donde puede surgir un amplio espectro de tumores, que son poco frecuentes y comprenden solo el 0,5 al 1,5% de las neoplasias de cabeza y cuello. Generalmente, son hallazgos y suelen presentarse como masas asintomáticas. Incluye neoplasias primarias, extensión directa de regiones adyacentes y enfermedad metastásica. La literatura describe múltiples patologías e histologías que pueden surgir de esta zona, entre ellas, tenemos los tumores fibrosos solitarios, que son un espectro de neoplasias mesenquimatosas fibroblásticas de histogénesis incierta, que generalmente involucran la pleura. Son lesiones muy poco frecuentes y su localización parafaríngea es excepcional, siendo su primer reporte en la literatura en 1993. Se presenta el caso de un tumor fibroso solitario del espacio parafaríngeo evaluado en nuestro centro, con su enfrentamiento diagnóstico, resolución quirúrgica y seguimiento respectivo, con el objetivo de presentar esta patología poco frecuente a nuestros colegas y contribuir al conocimiento médico.

The parapharyngeal space is a region where a wide spectrum of tumors can arise, which are rare and comprise only 0.5% to 1.5% of head and neck neoplasms. They are generally findings and usually present as asymptomatic masses. Includes primary neoplasms, direct extension from adjacent regions, and metastatic disease. The literature describes multiple pathologies and histologies that can arise from this area, among them, we have solitary fibrous tumors, which are a spectrum of fibroblastic mesenchymal neoplasms of uncertain histogenesis, which are generally the pleura. It is a very rare lesion and its parapharyngeal location is exceptional, being its first report in the literature in 1993. We present the case of a solitary fibrous tumor of the parapharyngeal space evaluated in our center, with its diagnos- tic confrontation, surgical resolution and respective follow-up, with the aim of presenting this rare pathology to our colleagues and contributing to medical knowledge.

Inactivation of SARS-CoV-2 isolates from lineages B.1.1.7 (Alpha), P.1 (Gamma) and B.1.110 by heating and UV irradiation.

Currently, the rapid global spread of SARS-CoV-2 is related to G clade (including GH, GR, GRY and GV clades), which are associated with more than 98 % of sequenced viral isolates worldwide. The unprecedented velocity of spread of SARS-CoV-2 outbreak represents a critical need for prevention strategies. Vaccines are recently being available and antiviral drugs have shown limited efficacy in COVID-19 patients. Thus, it is needed to know how to reduce the infectivity of the virus by different physicochemical conditions in order to prevent exposure to contaminated material. This work describes heating and irradiating UV-C light procedures to reduce the infectivity of SARS-CoV-2 belonging to different three lineages. Results of physicochemical treatment showed no differences among viral lineages. Analytical conditions for efficient inactivation of SARS-CoV-2 were determined.

A simple method for SARS-CoV-2 detection by rRT-PCR without the use of a commercial RNA extraction kit.

The World Health Organization (WHO) has declared a pandemic caused by a new coronavirus named SARS-CoV-2. The growing demand for commercial kits used for automated extraction of SARS-CoV-2 RNA, a key step before rRT-PCR diagnosis, could cause a shortage of stocks that hinders the rapid processing of samples. Although the recommendation is to use automated methods for nucleic acid extraction, alternatives are necessary to replace commercial kits. However, these alternatives should be as reliable as automated methods. This work describes a simple method to detect SARS-CoV-2 from specimens collected in different preservation media. Samples were previously inactivated by heating and precipitating with a PEG/NaCl solution before rRT-PCR assays for Orf1ab, N and S genes. The new method was compared with an automated protocol of nucleic acid extraction. Both procedures showed similar analytical results. Consequently, this simple and inexpensive method is a suitable procedure for laboratory diagnosis of SARS-CoV-2 infection.

Presencia y biometría de bazo accesorio en individuos chilenos: estudio por tomografía computarizada / Presence and biometry of accessory spleen in Chilean individuals: study by computerized tomography

El bazo se localiza en el cuadrante superior izquierdo del abdomen, relacionándose posteriormente con la 9a a 11a costilla, de las que se separa por el diafragma y el receso costodiafragmático, se localiza por detrás del estómago y lateralmente al riñón izquierdo. Por alteraciones en su desarrollo pueden generarse bazos accesorios (BA), considerándose un tejido ectópico del bazo. Se consideran tejido normal, con los mismos procesos fisiológicos que el bazo principal. Con el propósito de localizar y determinar aspectos biométricos de los mismos, se realizó un estudio de corte transversal y de carácter descriptivo, sobre una muestra de 220 exámenes de TC pertenecientes a pacientes mayores de 18 años del Hospital Regional Hernán Henríquez Aravena, Temuco, Chile. Para este estudio se excluyeron toda aquellas TC con antecedentes de esplenectomía y lesiones de Bazo o peri-esplénicas. El análisis de los datos mostró una prevalencia de 32,3 % de BA, pudiendo ser de una única presencia, dos e incluso tres BA por paciente.De un total de 71 personas que tienen al menos un BA, 34 (47,89 %) fueron de sexo femenino y 37 (52,11 %) de sexo masculino. Hubo 56 pacientes (78,9 %) con un BA, 29 (40,85 %) del sexo femenino y 27 (38,03 %) del masculino; 15 (21,1 %) presentaron más de un BA, 5 (7,04 %) de sexo femenino y 10 (14,08 %) de sexo masculino, si bien se puede observar variación en la cantidad de BA según sexo, no existe una relación estadísticamente significativa entre dichas variables. La ubicación más frecuente encontrada en el plano axial fue la zona antero-medial con 59 casos (66,29 %); asimismo, en el plano sagital, la localización más frecuente fue en el polo inferior con 40 casos (44,44 %). Datos biométricos de estos BA son mostrados en Tablas. Esta información será de gran valor morfológico y médico debido a la escasa literatura existente sobre esta materia en individuos chilenos.

The spleen is located in the upper left quadrant of the abdomen, subsequently related to the 9th to 11th rib, from which it is separated by the diaphragm and the cost-diaphragmatic recess, it is located behind the stomach and laterally to the left kidney. Due to alterations in its development, accessory spleens (AS) can be generated, being considered an ectopic tissue of the spleen. The AS are considered normal tissue, with the same physiological processes as the main spleen. With the purpose of locating and determining biometric aspects of them, a cross-sectional and descriptive study was carried out on a sample of 220 CT scans belonging to patients over 18 years of age at the Hernán Henríquez Aravena Regional Hospital, Temuco, Chile. For this study, all CT scans with a history of splenectomy and spleen or peri-splenic lesions were excluded. The analysis of the data showed a prevalence of 32.3 % of AS, being able to be of a single presence, two and even three AS per patient. Of a total of 71 people who have at least one AS, 34 (47.89 %) were female and 37 (52.11 %) male. There were 56 patients (78.9 %) with a one AS, 29 (40.85 %) of the female sex and 27 (38.03 %) of the male; 15 (21.1 %) presented more than one AS, 5 (7.04 %) female and 10 (14.08 %) male, although variation in the amount of AS according to sex can be observed, no there is a statistically significant relationship between these variables. The most frequent location found in the axial plane was the anteromedial zone with 59 cases (66.29 %); also, in the sagittal plane, the most frequent location was in the lower pole with 40 cases (44.44 %). Biometric data of these AS are shown in tables. This information will be of great morphological and medical value due to the limited existing literature on this subject in Chilean individuals.

Lymnaeid Snail Vectors of Fascioliasis, Including the First Finding of Lymnaea neotropica in Ecuador, Assessed by Ribosomal DNA Sequencing in the Southern Zone Close to the Peru Border.

PURPOSE: Fascioliasis is a freshwater snail-borne zoonotic trematodiasis of high pathogenicity and wide veterinary repercussions. In South America, moreover, it causes serious public health problems, with high human infection rates in Andean countries. Ecuador offers a worrying risky scenario due to its physiography, including many human infection reports and animal endemicity throughout its Andean highlands. METHODS: Endemic areas with increasing animal fascioliasis were surveyed for lymnaeid snails in the province of Loja, southern Ecuador, close to the border of Peru, the country known to present the widest human fascioliasis endemic zone. The altitude of the sampling sites ranged between 150 and 1770 m a.s.l., and their location was close to human villages. Biotopes surveyed were characterized according to fascioliasis transmission needs. RESULTS: The species Lymnaea schirazensis and L. neotropica were identified by rDNA ITS-2 and ITS-1 sequencing. The non-transmitting L. schirazensis combined haplotype agreed with populations of this species previously reported from northern Ecuador. The finding of the efficient vector L. neotropica is reported for the first time in Ecuador and suggests a passive introduction from neighbouring Peru by uncontrolled livestock transport. CONCLUSIONS: Rice irrigation system implementation, lymnaeid finding on Taraxacum (dandelion) plants which are consumed fresh in salads by people, and Saccharum (sugarcane), whose bark is peeled off with the teeth, represent potential infection sources for humans. The closeness to the Cajamarca human hyperendemic area in northern Peru, where the same two lymnaeids have been also found and triclabendazole resistance reported, is an additional risk to be considered regarding the livestock transborder exchange.

Tunable Spin-Polarized Edge Currents in Proximitized Transition Metal Dichalcogenides.

We explore proximity-induced ferromagnetism on transition metal dichalcogenides (TMDs), focusing on molybdenum ditelluride ribbons with zigzag edges, deposited on ferromagnetic europium oxide (EuO). A tight-binding model incorporates exchange and Rashba fields induced by proximity to EuO or similar substrates. For in-gap Fermi levels, electronic modes in the nanoribbon are localized along the edges, acting as one-dimensional (1D) conducting channels with tunable spin-polarized currents. TMDs on magnetic substrates can become very useful in spintronics, providing versatile platforms to study the proximity effects and electronic interactions in complex 1D systems.

Lateral heterostructures and one-dimensional interfaces in 2D transition metal dichalcogenides.

The growth and exfoliation of two-dimensional (2D) materials have led to the creation of edges and novel interfacial states at the juncture between crystals with different composition or phases. These hybrid heterostructures (HSs) can be built as vertical van der Waals stacks, resulting in a 2D interface, or as stitched adjacent monolayer crystals, resulting in one-dimensional (1D) interfaces. Although most attention has been focused on vertical HSs, increasing theoretical and experimental interest in 1D interfaces is evident. In-plane interfacial states between different 2D materials inherit properties from both crystals, giving rise to robust states with unique 1D non-parabolic dispersion and strong spin-orbit effects. With such unique characteristics, these states provide an exciting platform for realizing 1D physics. Here, we review and discuss advances in 1D heterojunctions, with emphasis on theoretical approaches for describing those between semiconducting transition metal dichalcogenides MX 2 (with M = Mo, W and X = S, Se, Te), and how the interfacial states can be characterized and utilized. We also address how the interfaces depend on edge geometries (such as zigzag and armchair) or strain, as lattice parameters differ across the interface, and how these features affect excitonic/optical response. This review is intended to serve as a resource for promoting theoretical and experimental studies in this rapidly evolving field.

Tumores de glándula submandibular: experiencia clínica del Hospital Guillermo Grant Benavente / Submandibular gland tumors: clinical experience of Guillermo Grant Benavente Hospital

RESUMEN Introducción: Los tumores de la glándula submandibular son poco frecuentes. Representan menos del 1% de todos los tumores de cabeza y cuello. Corresponden al 10% de los tumores de las glándulas salivales. Aproximadamente el 50% son malignos. Objetivos: Analizar la experiencia clínica con las submandibulectomias realizadas en el Servicio de Otorrinolaringología y Cirugía de Cabeza y Cuello del Hospital Guillermo Grant Benavente. Material y método: Estudio descriptivo retrospectivo. Revisión de fichas clínicas de pacientes intervenidos de submandibulectomía entre el 01 de enero de 2011 y el 31 de diciembre de 2016 en nuestro servicio. Resultados: Se realizaron 28 submandibulectomías por patología tumoral. La edad promedio fue de 54 años, siendo el 71% de sexo femenino. 21 tumores fueron benignos (75%), siendo el más frecuente el adenoma pleomorfo (14 casos), y 7 tumores malignos (25%), siendo el más frecuente el carcinoma adenoidequístico. Se reportaron dos complicaciones transitorias (7%), una paresia de la rama marginal del nervio facial y una paresia del nervio hipogloso. El 42% de los tumores malignos presentó recurrencia. Conclusión: Nuestra serie presenta resultados acordes a la literatura en cuanto a edad de presentación, distribución por sexo, tipos histológicos, tasa de complicaciones y recurrencia; sin embargo, difiere en la menor frecuencia de tumores malignos, siendo en nuestra serie de 25%. Patología poco frecuente. La presencia de una masa indolora submandibular debe ser derivada a los centros de referencia para estudio y eventual resolución quirúrgica por el riesgo de malignidad.

ABSTRACT Introduction: Submandibular gland tumors are rare. They represent less than 1% of all head and neck tumors. They correspond to 10% of the tumors of the salivary glands. Approximately 50% are malignant. Aim: To analyze the clinical experience with the submandibulectomies performed in the Otorhinolaryngology and Head and Neck Surgery Service of the Guillermo Grant Benavente Hospital. Material and Method: Retrospective descriptive study. Review of clinical records of patients treated with a submandibulectomy between January 1,2011 and December 31, 2016 in our service. Results: 28 submandibulectomies were performed due to tumor pathology. The average age was 54 years, being 71% female. 21 tumors were benign (75%), being the most frequent the pleomorphic adenoma (14 cases), and 7 malignant tumors (25%), being the most frequent the adenoidequistic carcinoma. Two transient complications (7%) were reported, a paresis of the marginal branch of the facial nerve and a paresis of the hypoglossal nerve. 42% of malignant tumors presented recurrence. Conclusion: Our series presents results according to the literature regarding age of presentation, distribution by sex, histological types, complication rate and recurrence; however, it differs in the lower frequency of malignant tumors, being in our series of 25%. Uncommon pathology. The presence of a submandibular painless mass must be referred to the reference centers for study and possible surgical resolution due to the risk of malignancy.

Paratiroidectomía transoral endoscópica por acceso vestibular oral: cirugía de paratiroides sin cicatriz: primer caso realizado en Sudamérica / Transoral endoscopic parathyroidectomy vestibular approach (TOEPVA)

Introducción: El abordaje de elección de la glándula tiroides y paratiroides, desde su descripción, ha sido la cervicotomía transversal. En el hiperparatiroidismo, con la optimización de los métodos de localización preoperatoria de las glándulas anómalas, se han creado técnicas abiertas mínimamente invasivas, con un mejor resultado estético y un menor tiempo de recuperación. Con el objetivo de eliminar las cicatrices externas se ha implementado una nueva técnica quirúrgica que utiliza abordajes endoscópicos a través de orificios naturales (NOTES). En los últimos años se ha hecho conocida una técnica de tiroidectomía y paratiroidectomía transoral endoscópica a través de incisiones en el vestíbulo oral. Caso clínico: Paciente de 65 años con hiperparatiroidismo primario con nódulo hiperfuncionante superior derecho que se somete a una paratiroidectomía parcial transoral endoscópica por abordaje vestibular. Resultados: El procedimiento se realiza sin incidentes con buena evolución posoperatoria de la paciente. Discusión: La paratiroidectomía transoral endoscópica por abordaje vestibular (TOEPVA) ha demostrado ser una técnica bastante segura, con resultados similares a los de la técnica abierta, pero sin dejar cicatrices visibles.

Introduction: The approach of choice of the thyroid and parathyroid glands, since its description, has been the transverse cervicotomy. In hyperparathyroidism, with the optimization of the preoperative localization methods of the anomalous glands, minimally invasive open techniques have been created, with a better aesthetic result and a shorter recovery time. With the aim of eliminating external scars, a new surgical technique has been implemented that uses endoscopic approaches through natural orifices (NOTES). In recent years, a transoral endoscopic thyroidectomy and parathyroidectomy technique through incisions in the oral vestibule has been known. Clinical case: A 65-year-old patient with primary hyperparathyroidism with right upper hyperfunctioning nodule who underwent partial transoral endoscopic parathyroidectomy due to vestibular approach. Results: The procedure is performed without incidents with good postoperative evolution of the patient. Discussion: Transoral endoscopic parathyroidectomy by vestibular approach (TOEPVA) has proven to be a fairly safe technique, with results similar to open technique, but without leaving visible scars.

Angiofibroma de fosa temporal: reporte de un caso / Temporal fossa angiofibroma: a case report

RESUMEN El angiofibroma nasofaríngeo es el tumor benigno más frecuente de la nasofaringe, representando el 0,05% del total de las neoplasias de cabeza y cuello. Los angiofibromas en localizaciones distintas a la nasofaringe son entidades raras. Ellos son descritos esporádicamente en la literatura, ubicándose principalmente en el seno maxilar. En este artículo presentamos un caso de fibroangioma extranasofaríngeo localizado en fosa temporal derecha seguido de una revisión de literatura.

ABSTRACT Nasopharyngeal angiofibroma is the most common benign tumor of the nasopharynx, representing 0.05% of total neoplasms of the head and neck. Extranasopharyngeal angiofibromas are rare entities described sporadically in the literature, being located mainly in the maxillary sinus. We present a case of an extra-nasopharyngeal fibroangioma located in the right temporal fossa followed by a literature review.

Flea market finds and global exports: Four multistate outbreaks of human Salmonella infections linked to small turtles, United States-2015.

Zoonotic transmission of Salmonella infections causes an estimated 11% of salmonellosis annually in the United States. This report describes the epidemiologic, traceback and laboratory investigations conducted in the United States as part of four multistate outbreaks of Salmonella infections linked to small turtles. Salmonella isolates indistinguishable from the outbreak strains were isolated from a total of 143 ill people in the United States, pet turtles, and pond water samples collected from turtle farm A, as well as ill people from Chile and Luxembourg. Almost half (45%) of infections occurred in children aged <5 years, underscoring the importance of the Centers for Disease Control and Prevention recommendation to keep pet turtles and other reptiles out of homes and childcare settings with young children. Although only 43% of the ill people who reported turtle exposure provided purchase information, most small turtles were purchased from flea markets or street vendors, which made it difficult to locate the vendor, trace the turtles to a farm of origin, provide education and enforce the United States federal ban on the sale and distribution of small turtles. These outbreaks highlight the importance of improving public awareness and education about the risk of Salmonella from small turtles not only in the United States but also worldwide.

Carcinoma adenoide quístico de cavidad nasal y senos paranasales: experiencia de 5 años en Clínica Las Condes de Santiago de Chile / Adenoid cystic carcinoma of nasal cavity and paranasal sinuses: 5 years experience in las Condes Clinic of Santiago of Chile

RESUMEN Introducción: El carcinoma adenoide quístico es una neoplasia originada en glándulas exocrinas de todo el cuerpo, principalmente en glándulas salivales mayores. En cavidad nasal y senos paranasales es poco frecuente y se caracteriza por presentar una alta frecuencia de recurrencia y de metástasis a distancia posterior a su remisión y a pesar de su tratamiento. Objetivo: Describir características de una serie de casos de pacientes con carcinoma adenoide quístico de cavidad nasal y senos paranasales operados. Material y método: Estudio descriptivo-retrospectivo. Período enero de 2012 y enero de 2017. La información se obtuvo a partir de las fichas electrónicas de la Clínica Las Condes. Se describen procedencia, edad y sexo, características clínicas, hallazgos anatomopatológicos, métodos diagnósticos, tratamiento, evolución. Resultados: Total de 5 pacientes operados, 3 mujeres y 2 hombres. La edad promedio fue de 63 años, con rango de 33 años a 90 años de edad. 100% de los casos sin factores asociados. La presentación clínica más frecuente fue la obstrucción nasal unilateral, seguida por el dolor facial. Dos pacientes se presentaron con diagnóstico inicial, dos por recurrencia y uno por persistencia. En tres casos el tumor se origina de seno maxilar y en dos en seno etmoidal. Todos presentaron enfermedad avanzada, etapa IV y III. Tres pacientes histológicamente fueron de bajo grado y dos de alto grado. En los cinco casos el tratamiento primario fue quirúrgico, en el 60% endoscópico, 20% abierto y 20% combinado. En cuatro casos se usó radioterapia posoperatoria y en tres de éstos, quimioterapia concomitante. Todos se encuentran sin signos de recidiva tumoral en último control. Conclusiones: El carcinoma adenoide quístico de cavidad nasal y senos paranasales es bastante infrecuente, su incidencia es menor a 1/100.000 casos por año. Es más frecuente en mujeres entre 40 y 50 años. Se identifica más con su origen en el seno maxilar (50%) y de patrón cribiforme. Clínicamente se presenta en estadíos avanzados ya que en etapa precoz es asintomático o presenta clínica inespecífica inflamatoria. El diagnóstico se realiza con biopsia complementada con imagenología. El tratamiento más utilizado es la cirugía endoscópica o abierta asociado a radioterapia posoperatoria, a pesar de la cual, se presentan con alta recurrencia a largo plazo.

ABSTRACT Introduction: Adenoid Cystic Carcinoma is a neoplasm originating in exocrine glands throughout the body, mainly in the major salivary glands. In the nasal cavity and paranasal sinuses is rare and characterized by a high frequency of recurrence and distant metastasis after remission and despite its treatment. Aim: To describe characteristics of a series of patients with operated adenoid cystic carcinoma of the nasal cavity and paranasal sinuses. Material and method: Descriptive-retrospective study. Period January 2012 and January 2017. The information was obtained from the electronic tabs of the Las Condes Clinic. It describes origin, age and sex, clinical characteristics, anatomopathological findings, diagnostic methods, treatment, evolution. Results: Total 5 patients operated, 3 women and 2 men. The average age was 63 years, ranging from 33 years to 90 years of age. 100% of the cases without associated factors. The most frequent clinical presentation was unilateral nasal obstruction, followed by facial pain. 2 patients presented with initial diagnosis, 2 due to recurrence and 1 due to persistence. In 3 cases the tumor originates from the maxillary sinus and in 2 in the ethmoidal sinus. All had advanced disease, stage IV and III. 3 patients were histologically low grade and 2 high grade. In all 5 cases, the primary treatment was surgical, 60% endoscopic, 20% open and 20% combined. In 4 cases, postoperative radiotherapy was used and in 3 of this concomitant chemotherapy. All are without signs of tumor recurrence in the last control. Conclusion: Adenoid Cystic Carcinoma of the nasal cavity and paranasal sinuses is quite infrequent; its incidence is less than 1/100,000 cases per year. It is more common in women between 40 and 50 years. It is identified more with its origin in the maxillary sinus (50%) and cribriform pattern. Clinically it presents in advanced stages since at an early stage, it is asymptomatic or it presents nonspecific inflammatory clinic. Diagnosis is performed with biopsy supplemented with imaging. The most commonly used treatment is endoscopic or open surgery associated with postoperative radiotherapy, despite which, they present with high recurrence in the long term.

Long range of indirect exchange interaction on the edges of MoS2 flakes.

We study the Ruderman-Kittel-Kasuya-Yosida interaction between two magnetic impurities connected to the edges of zigzag-terminated MoS2 flakes. When the impurities lie on the edges of the flake, the effective exchange interaction exhibits sizable noncollinear Dzyaloshinskii-Moriya character that competes with a strong Ising coupling. We analyze the characteristic decay exponent for doping levels inside the band gap of the infinite layer, corresponding to edge states of the flake at the Fermi level. The characteristic exponents show sub-two-dimensional behavior for these band fillings, with decays much slower than quadratic. The Ising interaction has effectively one-dimensional long range, while the noncollinear component that grows for short impurity separation becomes comparable in magnitude. The resulting tunable exchange interaction on these systems opens the way for the study of interesting phases of impurity arrays with long-range stable helical order.

Detecting coupling of Majorana bound states with an Aharonov-Bohm interferometer.

We study the transport properties of an interferometer composed by a quantum dot (QD) coupled with two normal leads and two one-dimensional topological superconductor nanowires (TNWs) hosting Majorana bound states (MBS) at their ends. The geometry considered is such that one TNW has both ends connected with the QD, forming an Aharonov-Bohm (AB) interferometer threaded by an external magnetic flux, while the other TNW is placed near the interferometer TNW. This geometry can alternatively be seen as a long wire contacted across a local defect, with possible coupling between independent-MBS. We use the Green's function formalism to calculate the conductance across normal current leads on the QD. We find that the conductance exhibits a half-quantum value regardless of the AB phase and location of the dot energy level, whenever the interferometer configuration interacts with the neighboring TNW. These findings suggest that such a geometry could be used for a sensitive detection of MBS interactions across TNWs, exploiting the high sensitivity of conductance to the AB phase in the interferometer.

Satellite DNA methylation status and expression of selected genes in Bos indicus blastocysts produced in vivo and in vitro.

Bovine embryos produced in vivo and in vitro differ with respect to molecular profiles, including epigenetic marks and gene expression profiles. This study investigated the CpG methylation status in bovine testis satellite I (BTS) and Bos taurus alpha satellite I (BTαS) DNA sequences, and concomitantly the relative abundance of transcripts, critically involved in DNA methylation (DNMT1 and DNMT3A), growth and development (IGF2R) and pluripotency (POU5F1) in Bos indicus embryos produced in vitro or in vivo. Results revealed that methylation of BTS were higher (P < 0.05) in embryos produced in vitro compared with their in vivo produced counterparts, while the methylation status of BTαS was similar in both groups. There were no significant differences in transcript abundance for DNMT3A, IGF2R and POU5F1 between blastocysts produced in vivo and in vitro. However, a significantly lower amount of DNMT1 transcripts was found in the in vitro cultured embryos (P < 0.05) compared with their in vivo derived counterparts. In conclusion, this study reported only minor changes in the expression of developmentally important genes and satellite DNA methylation related to the in vitro embryo production system.

Experiencia clínica en tiroidectomía total del Servicio de Otorrinolaringología y Cirugía de Cabeza y Cuello Hospital Guillermo Grant Benavente / Clinical experience in total thyroidectomy of the Department of Otolaryngology and Head and Neck Surgery of Guillermo Grant Benavente Hospital

Introducción: La tiroidectomía es una de las cirugías más frecuentes realizadas en cabeza y cuello. Existen escasos reportes de experiencia en tiroidectomías en servicios de otorrinolaringología en Chile. Objetivo: Analizar la experiencia clínica con las tiroidectomías totales realizadas en el Servicio de ORL y Cirugía de Cabeza y Cuello de nuestro hospital. Material y método: Estudio descriptivo retrospectivo. Revisión de fichas clínicas de pacientes sometidos a tiroidectomías totales (TT) entre los años 2010 y 2014 en nuestro servicio. Resultados: Se realizaron 271 tiroidectomías totales. La indicación más frecuente fue por tamaño (51%). Los diagnósticos más frecuentes fueron carcinomas papilares (46%) e hiperplasia folicularcoloidea (37%). Se presentaron lesiones transitorias del nervio laríngeo recurrente en 2,9%, y lesiones persistentes en 2,5%. Hipocalcemia transitoria se presentó en el 25% de los pacientes. Discusión: Nuestra serie presenta resultados concordantes con la literatura, presenta una baja tasa de complicaciones, las cuales se observan principalmente en pacientes con vaciamiento cervical y/o en que se observaron 2 o menos paratiroides. Conclusiones: La tiroidectomía total es una técnica quirúrgica segura y nuestra experiencia presenta resultados concordantes a los publicados en la literatura internacional.

Introduction: Thyroidectomy is one of the most common surgeries performed in head and neck. There are few reports of experience in thyroidectomy in otolaryngology services in Chile. Aim: To analyze the clinical experience with total thyroidectomy performed in the service of ENT and Head and Neck Surgery of our hospital. Material and method: Retrospective descriptive study. Review of medical records of patients undergoing total thyroidectomy (TT) between 2010 and 2014 in our service records. Results: A total of 271 thyroidectomy were performed. The most frequent indication was size (51%). The most frequent diagnoses were papillary carcinomas (46%) and follicular colloid hyperplasia (37%). We found 2.5% of transient recurrent laryngeal nerve injury and 2.9% had persistent lesions. Transient hypocalcemia occurred in 25% of patients. Discussion: Our series shows good agreement with literature, it has a low rate of complications, which are mainly seen in patients with neck dissection and/or observed 2 or less parathyroid during surgery. Conclusions: Total thyroidectomy is a safe surgical technique, and our experience shows consistent results to those reported in international literature.

A report on the outbreak of Zika virus on Easter Island, South Pacific, 2014.

Zika virus (ZIKV) is an emerging mosquito-borne flavivirus circulating in Asia and Africa. In 2013, a large outbreak was reported on the archipelago of French Polynesia. In this study, we report the detection and molecular characterization of Zika virus for the first time in Chile from an outbreak among the inhabitants of Easter Island. A total of 89 samples from patients suspected of having ZIKV infection were collected between the period from January to May, 2014. Molecular diagnosis of the virus was performed by RT-PCR followed by the sequencing of the region containing the NS5 gene. A comparison of the viral nucleic acid sequence with those of other strains of ZIKA virus was performed using the MEGA software. Fifty-one samples were found positive for ZIKV by RT-PCR analysis. Further analysis of the NS5 gene revealed that the ZIKV strains identified in Easter Island were most closely related to those found in French Polynesia (99.8 to 99.9% nt and 100% aa sequence identity). These results strongly suggest that the transmission pathway leading to the introduction of Zika virus on Easter Island has its origin in French Polynesia.

Rapid spread of Clostridium difficile NAP1/027/ST1 in Chile confirms the emergence of the epidemic strain in Latin America.

Clostridium difficile infection has gained importance in recent years as a result of the rapid spread of epidemic strains, including hypervirulent strains. This study reports the molecular epidemiology of C. difficile obtained from hospitalized patients in Chile. Seven hundred and nineteen isolates of toxigenic C. difficile from 45 hospitals across the country were characterized through toxin profile, pulsed-field gel electrophoresis (PFGE), and sequencing of the tcdC gene. In addition, polymerase chain reaction (PCR) ribotyping and multilocus sequence typing (MLST) were performed on a subset of selected strains. PFGE typing of 719 isolates of C. difficile produced 60 PFGE patterns (subtypes). Subtype 1 was predominant (79% of isolates) and related to the hypervirulent strain (NAP1). Subtype 1 showed 73% relatedness with nine other subtypes, which had a similar tcdC deletion. Subtype 1 corresponded to ribotype 027 and ST1. This report shows the wide dissemination of the hypervirulent strain NAP1/027/ST1 in Chile.

Experiencia quirúrgica del Servicio de Otorrinolaringología y Cirugía de Cabeza y Cuello del Hospital Guillermo Grant Benavente durante el periodo 2007-2011 / Surgical experience of the Department of Otolaryngology and Head and Neck Surgery from Guillermo Grant Benavente Hospital

Introducción: Nuestra especialidad plantea una amplia gama de polos de perfeccionamiento medicoquirúrgico. Es necesario conocer la situación actual de nuestros servicios, en base a lo cual poder delinear futuras áreas de desarrollo. Objetivo: Conocer la experiencia quirúrgica del Servicio de Otorrinolaringología y Cirugía de Cabeza y Cuello del Hospital Guillermo Grant Benavente. Material y método: Estudio observacional retrospectivo. Análisis de libros de pabellón, protocolos quirúrgicos e información estadística del centro durante los años 2007-2011. Resultados: Se realizaron 8.262 cirugías durante el periodo estudiado, con un promedio de 1.921 cirugías anuales. Las áreas quirúrgicas más prevalentes son faringe (44%), rinosinusología (18%) y otología (17%). Discusión: En nuestro centro se desarrolla una amplia y variada gama de procedimientos quirúrgicos. Existen áreas de un significativo potencial de desarrollo, tales como la cirugía endoscópica rinosinusal y la cirugía de cabeza y cuello.

Introduction: Our specialty poses a wide range of medical and surgical areas of improvement. We need to know the current status of our services to delineate future development areas. Aim: To determine the surgical experience of the Department of Otolaryngology and Head and Neck Surgery from Guillermo Grant Benavente Hospital. Material and method: Retrospective observational study. Surgery room books, surgical protocols and statistical information center reviews. Results: We performed 8262 surgeries during the study period, with an average of 1921 surgeries annually. The most prevalent surgical areas are Pharynx (44%%), Rhinosinusal (18%) and Otology (17%). Conclusions: In our center, we developed a wide and varied range of surgical procedures. There are areas of significant development potential, such as endoscopic rhinosinusal and head and neck surgery.

Helicoidal fields and spin polarized currents in carbon nanotube-DNA hybrids.

We report on theoretical studies of electronic transport in the archetypical molecular hybrid formed by DNA wrapped around single-walled carbon nanotubes (CNTs). Using a Green's function formalism in a π-orbital tight-binding representation, we investigate the role that spin-orbit interactions play on the CNT in the case of the helicoidal electric field induced by the polar nature of the adsorbed DNA molecule. We find that spin polarization of the current can take place in the absence of magnetic fields, depending strongly on the direction of the wrapping and length of the helicoidal field. These findings open new routes for using CNTs in spintronic devices.