Forest buffer-strips mitigate the negative impact of oil palm plantations on stream communities.

The global area cultivated with oil palm has doubled in the past two decades, causing deforestation, land-use change, freshwater pollution, and species loss in tropical ecosystems worldwide. Despite the palm-oil industry been linked to severe deterioration of freshwater ecosystems, most studies have focused on terrestrial environments, while freshwaters have been significantly less studied. We evaluated these impacts by contrasting freshwater macroinvertebrate communities and habitat conditions in 19 streams from primary forests (7), grazing lands (6), and oil palm plantations (6). In each stream, we measured environmental characteristics, e.g., habitat composition, canopy cover, substrate, water temperature, and water quality; and we identified and quantified the assemblage of macroinvertebrates. Streams in oil palm plantations lacking riparian forest strips showed warmer and more variable temperatures, higher turbidity, lower silica content, and poorer macroinvertebrate taxon richness than primary forests. Grazing lands showed higher conductivity and temperature, and lower dissolved oxygen and macroinvertebrate taxon richness than primary forests. In contrast, streams in oil palm plantations that conserved a riparian forest, showed a substrate composition, temperature, and canopy cover more similar to the ones in primary forests. These habitat improvements by riparian forests in the plantations increased macroinvertebrate taxon richness and maintained a community resembling more the one in primary forests. Therefore, the conversion of grazing lands (instead of primary forests) to oil palm plantations can increase freshwater taxon richness only if riparian native forests are safeguarded.

Prevalencia de infección por Chlamydia trachomatis y relación con el perfil de conductas sexuales en adolescentes y mujeres jóvenes de la Provincia de Osorno, Chile / Prevalence of Chlamydia trachomatis infection and relationship with the profile of sexual behaviors in adolescents and young women in the Province of Osorno, Chile

INTRODUCCIÓN: La infección por Chlamydia trachomatis es la ITS bacteriana más frecuente del mundo. En el cervix se presenta mayormente de forma asintomática y afecta especialmente a mujeres jóvenes y adolescentes. Puede producir daño permanente en el tracto reproductor femenino, se asocia a parto prematuro, infecciones neonatales transmitidas vía vertical y mayor riesgo de adquirir otras ITS como VIH Y VPH. Por estos motivos se han establecido estrategias de tamizaje para detectar y tratar precozmente la infección asintomática por C. trachomatis en diferentes países. En nuestro país no contamos con un programa nacional de tamizaje. OBJETIVO: Determinar la prevalencia de infección asintomática por Chlamydia trachomatis en mujeres entre 12 y 21 años de la Provincia de Osorno, Región de Los Lagos, Chile. PACIENTES Y MÉTODOS: Se desarrolló un estudio de diseño transversal con una cohorte única de mujeres adolescentes y jóvenes consultantes en el Policlínico de Alto Riesgo Obstétrico y de Ginecología Infantil y Adolescente, del Hospital Base de Osorno, entre enero de 2019 y enero 2020. Se determinó el estado de infección asintomática mediante RPC en tiempo real para C. trachomatis. Se realizó una encuesta a fin de determinar características demográficas, hábitos y conductas sexuales de las pacientes estudiadas. RESULTADOS: Fueron reclutadas 124 mujeres entre 12 a 21 años de edad, de las cuales, 36 (29,3%) se encontraban embarazadas al momento del estudio. La prevalencia de infección asintomática por C. trachomatis fue de 14/124 (11,3%). En las mujeres gestantes se encontraron 6/36 (16,7%) casos positivos de infección por C. trachomatis y 8/88 (9,1%) en las no gestantes. Existe una mayor frecuencia de infección asintomática a menor edad de inicio de actividad sexual (33,3% en aquellas que inician entre 11-12 años vs. 16,2% en las que inician entre 1314 años, 7,4% entre 15-16 y 8% entre 17-21 años; p < 0,05). Esta tendencia no fue observada al comparar el estado de infección con el tiempo de vida sexual activa. Sólo 15,7% de las pacientes utilizó preservativo en todas sus relaciones sexuales. DISCUSIÓN: La infección asintomática por C. trachomatis es frecuente en las mujeres adolescentes y jóvenes sexualmente activas. Las pacientes con inicio más temprano de la actividad sexual coital (bajo 13 años de edad) podrían estar en mayor riesgo. Se requiere con urgencia establecer la frecuencia nacional de infección para desarrollar una estrategia sanitaria para su pesquisa y manejo oportuno en nuestro país.

BACKGROUND: Chlamydia trachomatis infection is the world most common bacterial STI. At uterine cervix it presents mostly asymptomatically and especially affects young women and adolescents. It can cause permanent damage to the female reproductive tract and is associated with premature birth, connatal infections and increased risk of acquiring other STIs such as HIV and HPV. For these reasons, other countries have established screening strategies to detect and treat asymptomatic C. trachomatis infection. Our country don't have a national screening program. AIM: To determine the prevalence of C. trachomatis asymptomatic infection in adolescent and young women in Osorno province, Los Lagos Region, Chile. METHODS: A crosssectional study was performed in adolescent and young women who consult at Hospital Base Osorno in the MaternoFetal and PediatricAdolescent Gynecology ambulatory clinics, between January 2019 and January 2020. The status of asymptomatic infection was determined by PCR for C. trachomatis. A survey was carried out to determine the demographic characteristics, habits and sexual behaviors. RESULTS: 124 women between 12 and 21 years of age were recruited, of which 36 (29,3%) were pregnant at the time of the study. The prevalence of asymptomatic infection by C. trachomatis was 11.3.%. In pregnant women, there were 6/36 (16.7%) positive cases for C. trachomatis and 8/88 (9.1%) in nonpregnant women. We found a higher frequency of asymptomatic infection at younger age of first sexual intercourse (33% in adolescents at 11-12 years old vs. 16.2% at 13-14, 7.4% at 15-16 and 8% at 17-21; p<0.05). Only 15.7% of the patients utilized condoms in all their intercourses. DISCUSSION: Asymptomatic C. trachomatis infection is common in adolescent and young women, with a higher risk in those who onset sexual activity at an early age (less than 13 years old). It is urgently required to determine the national frequency of asymptomatic C. trachomatis infection to develop a national strategy for screening and timely treatment.

Unusual Magnetic Hysteresis and Transition between Vortex and Double Pole States Arising from Interlayer Coupling in Diamond-Shaped Nanostructures.

Controlling the magnetic ground states at the nanoscale is a long-standing basic research problem and an important issue in magnetic storage technologies. Here, we designed a nanostructured material that exhibits very unusual hysteresis loops due to a transition between vortex and double pole states. Arrays of 700 nm diamond-shaped nanodots consisting of Py(30 nm)/Ru(tRu)/Py(30 nm) (Py, permalloy (Ni80Fe20)) trilayers were fabricated by interference lithography and e-beam evaporation. We show that varying the Ru interlayer spacer thickness (tRu) governs the interaction between the Py layers. We found this interaction mainly mediated by two mechanisms: magnetostatic interaction that favors antiparallel (antiferromagnetic, AFM) alignment of the Py layers and exchange interaction that oscillates between ferromagnetic (FM) and AFM couplings. For a certain range of Ru thicknesses, FM coupling dominates and forms magnetic vortices in the upper and lower Py layers. For Ru thicknesses at which AFM coupling dominates, the magnetic state in remanence is a double pole structure. Our results showed that the interlayer exchange coupling interaction remains finite even at 4 nm Ru thickness. The magnetic states in remanence, observed by magnetic force microscopy (MFM), are in good agreement with corresponding hysteresis loops obtained by the magneto-optic Kerr effect (MOKE) and micromagnetic simulations.

Electrical Cochlear Response as an Objective Measure of Hearing Threshold and Hearing Performance Evaluation in Pediatric Cochlear Implant Users / Respuesta Coclear Eléctrica como Medida Objetiva del Umbral Auditivo y la Evaluación del Rendimiento Auditivo en Usuarios Pediátricos de Implante Coclear

ABSTRACT The difficulties of applying the audiometry in pediatric populations and its methodological limitations in implanted patients have spurred the development of new alternative auditory evaluation methods. This study aimed to show an objective method to estimate hearing thresholds in pediatric cochlear implanted patients through Electrical Cochlear Response (ECR) and to quantify the hearing performance by using an Auditory Skills Questionnaire (ASQ) and a Calibrated Sounds Test (CST) designed on purpose. Eighteen implanted patients, 1-6 years old underwent standard audiometry, ECR, and ASQ in two evaluation sessions T1 and T2. At T2, in addition, patients underwent CST. For patients ≤3 years old (G1), Pure Tone Averages (PTA and PTAECR)showed a statistically significant difference between them at T1 and T2. At T2 improvements in audiometric and ECR thresholds were observed (p<0.05), regarding T1. Patients older than 3 years (G2) had significantly better ASQ and CST scores. CST detection scores at 40 dBHL for groups G1 and G2, 36% and 70% respectively, showed a better relationship to ECR thresholds. The relationship observed between ECR thresholds and CST detection scores seems to confirm that ECR brings the feasibility of objective hearing threshold estimation and provides a better frequency resolution than audiometry.

RESUMEN Las dificultades para la aplicación de la audiometría en la población pediátrica además de sus limitaciones metodológicas en pacientes usuarios de implante coclear, señalan la necesidad de métodos audiométricos alternos. En el presente trabajo se utiliza el potencial eléctrico, denominado Respuesta Coclear Eléctrica (ECR) observado solamente en usuarios de implante coclear, para la estimación de umbrales auditivos prescindiendo de la participación consiente del paciente, además de evaluar el desempeño auditivo mediante un Cuestionario de Habilidades Auditivas (ASQ) y la Prueba de Sonidos Calibrados (CST). A dieciocho participantes de 1 a 6 años, se les practicó Audiometría, ECR y ASQ en dos sesiones, T1 y T2; adicionalmente, en T2 se aplicó CST. En T1 y T2 los promedios de tonos puros, PTA y PTAECR, de pacientes ≤ 3 años (G1), mostraron una diferencia estadísticamente significativa entre ellos. En T2 los umbrales audiométricos y ECR (p <0.05), mejoraron respecto de T1. Pacientes > 3 años (G2) lograron puntuaciones ASQ y CST significativamente mejores. Los puntajes de detección CST a 40 dBHL, G1(36%) y G2(70%), mostraron mejor relación con los umbrales ECR. Esta relación entre los umbrales ECR y los puntajes de detección CST indican que la ECR permite estimar el umbral de audición, logrando adicionalmente mayor resolución en frecuencia que la audiometría.

Vascular Parameters for Ambulatory Monitoring of Congestive Heart Failure Patients: Proof of Concept.

PURPOSE: Prompt detection of congestion is an essential target in order to prevent heart failure (HF) related hospitalization, being ambulatory monitoring a promising strategy to do so. A successful non-invasive ambulatory monitoring system requires automatic devices for physiological data recording; these data must give information about HF deterioration early enough to predict HF-related adverse events. This work aims to evaluate seven vascular parameters for the ambulatory monitoring of congestive heart failure patients. METHODS: Seven vascular parameters are proposed as indicators of HF deterioration. These parameters are obtained using venous occlusion plethysmography; a technique that uses hardware able of being miniaturized and easily integrated into wearables for ambulatory monitoring. The ability of the proposed vascular parameters to detect congestion is evaluated in eight healthy volunteers and ten congestive heart failure patients with different congestion levels-mild, moderate and severe. RESULTS: Most parameters distinguish between healthy volunteers and heart failure patients, and some of them present significant differences between volunteers and low levels of congestion-mild or moderate. CONCLUSION: Home monitoring of some of the proposed parameters could detect HF deterioration on its onset and alert to health personnel.

Evaluación comparativa del proceso de conciliación medicamentosa realizado por el departamento de Enfermería y el de Farmacia en un hospital privado de Costa Rica / Comparative evaluation of the medication conciliation process performed by the Nursing and Pharmacy services at a private hospital in Costa Rica

Introducción: Los errores de medicación generan riesgos en el paciente hospitalizado y constituyen una de las principales causas del incremento en la morbi-mortalidad y costos económicos; por tanto la conciliación de medicamentos constituye una solución para reforzar la seguridad de los pacientes en los procesos de transición asistencial. Objetivos: Determinar la magnitud de los errores de conciliación en los servicios del ámbito hospitalario descrito y su impacto en el paciente. Métodos: Estudio observacional, prospectivo, con una muestra de pacientes ingresados a los servicios de internamiento del Hospital, que cumplieran con los criterios de inclusión; la información necesaria para comparar los resultados de la conciliación de medicamentos fue tomada de una entrevista, la Valoración Inicial de Enfermería y el expediente clínico. Resultados: Nueve de cada diez pacientes presentó al menos una discrepancia en su medicación. Entre el promedio de medicamentos conciliados por el departamento de Farmacia y mediante la Valoración Inicial de Enfermería existe una diferencia estadísticamente significativa (p=0.00001, IC 95%). La mayor discrepancia se presentó con medicamentos del sistema cardiovascular, tracto gastrointestinal y metabolismo, y sistema nervioso central. Se presentaron 151 casos de error tipo B, 376 de tipo C, y 138 de tipo D. Conclusiones:Sí existen discrepancias significativas entre la conciliación de medicamentos realizada por el servicio de Enfermería y por el de Farmacia, tanto en cantidad como en tipo. Se recomienda que la conciliación se dirija prioritariamente a pacientes mayores de 65 años, con pluripatologías y en tratamiento con fármacos que actúan sobre los sistemas fisiológicos mencionados (AU)

Introduction: Medication errors produce risks in the hospitalized patient and constitute one of the main causes in the raise of morbidity and mortality together with the economic costs associated. Therefore the medication conciliation can be a solution to reinforce patient safety in the transitional process of medical assistance. Objective: To determine the significance of conciliation’s errors in the described services and their impact in patients. Methods: It was carried out a prospective, observational study with a sample of admitted patients in the hospitalized services who met the inclusion criteria; the information needed for the comparison was obtained from a patient’s interview, the Nursing Initial Assessment and the clinical record. Results: Nine out of ten patients presented at least a discrepancy in their medication. There is a significant statistical difference between the average number of medications conciliated by the Pharmacy Service and the Nursing Initial Assessment (p=0.00001, CI 95%). The higher discrepancy was observed with medications used to treat ailments from the cardiovascular system, gastrointestinal system, metabolism and central nervous system. There were 151 cases of type B error, 376 for type C and 138 for type D. Conclusions: There are significant discrepancies between the medication conciliation performed by the Nursing Service and the Pharmacy Service both, in quantity and in type. Conciliation process is considered a priority for patients over 65 years old, with multiple ailments and treated with medications used for the above mentioned systems (AU)

Insuficiencia hepática aguda fulminante por virus de la hepatitis B: reporte de caso / Acute liver failure due to hepatitis B: a case report

Se reporta el caso de una mujer de 37 años de edad sin antecedentes relevantes, que consulta por cuadro febril ictérico asociado con alteración hepática importante con patrón necroinflamatorio, se documenta hepatitis viral B y presenta una evolución tórpida rápida hasta la muerte. De esta forma, se exponen los posibles factores que influyen en la progresión hacia la insuficiencia hepática fulminante (IHF) descritos en la literatura.

We report the case of a 37 year old woman who came to the hospital because of jaundice and a fever. Her symptoms were associated with significant liver impairment and a necroinflammatory pattern due to viral hepatitis B although she had no relevant medical history. Her symptoms developed rapidly until death. We present the factors that may have influenced her progression to fulminant liver failure as described in the literature.

Neotropical Bats from Costa Rica harbour Diverse Coronaviruses.

Bats are hosts of diverse coronaviruses (CoVs) known to potentially cross the host-species barrier. For analysing coronavirus diversity in a bat species-rich country, a total of 421 anal swabs/faecal samples from Costa Rican bats were screened for CoV RNA-dependent RNA polymerase (RdRp) gene sequences by a pancoronavirus PCR. Six families, 24 genera and 41 species of bats were analysed. The detection rate for CoV was 1%. Individuals (n = 4) from four different species of frugivorous (Artibeus jamaicensis, Carollia perspicillata and Carollia castanea) and nectivorous (Glossophaga soricina) bats were positive for coronavirus-derived nucleic acids. Analysis of 440 nt. RdRp sequences allocated all Costa Rican bat CoVs to the α-CoV group. Several CoVs sequences clustered near previously described CoVs from the same species of bat, but were phylogenetically distant from the human CoV sequences identified to date, suggesting no recent spillover events. The Glossophaga soricina CoV sequence is sufficiently dissimilar (26% homology to the closest known bat CoVs) to represent a unique coronavirus not clustering near other CoVs found in the same bat species so far, implying an even higher CoV diversity than previously suspected.

The expanding fireball of Nova Delphini 2013.

A classical nova occurs when material accreting onto the surface of a white dwarf in a close binary system ignites in a thermonuclear runaway. Complex structures observed in the ejecta at late stages could result from interactions with the companion during the common-envelope phase. Alternatively, the explosion could be intrinsically bipolar, resulting from a localized ignition on the surface of the white dwarf or as a consequence of rotational distortion. Studying the structure of novae during the earliest phases is challenging because of the high spatial resolution needed to measure their small sizes. Here we report near-infrared interferometric measurements of the angular size of Nova Delphini 2013, starting one day after the explosion and continuing with extensive time coverage during the first 43 days. Changes in the apparent expansion rate can be explained by an explosion model consisting of an optically thick core surrounded by a diffuse envelope. The optical depth of the ejected material changes as it expands. We detect an ellipticity in the light distribution, suggesting a prolate or bipolar structure that develops as early as the second day. Combining the angular expansion rate with radial velocity measurements, we derive a geometric distance to the nova of 4.54 ± 0.59 kiloparsecs from the Sun.

Clinical and immunological features of common variable immunodeficiency in Mexican patients

BACKGROUND: Common variable immunodeficiency (CVID) is characterised by hypogammaglobulinaemia and a broad clinical spectrum, mainly showing recurrent bacterial infections accompanied sometimes by increased susceptibility to chronic lung disease, autoimmunity, and neoplastic diseases. OBJECTIVES: To evaluate the clinical and immunological characteristics of patients with CVID in Mexico. METHODS: This is a retrospective analysis of 43 patients with CVID from the Immunology Division of seven different reference centres in Mexico. Patients were diagnosed according to the diagnostic criteria of the European Society for Immunodeficiency Diseases. We collected demographics, clinical and immunological data from each patient and a statistical analysis was performed. RESULTS: There were 23 (53.5%) male and 20 (46.5%) female patients. Median age at onset of disease was 13.7 years, and median age at diagnosis was 19 years. Average delay in diagnosis was 12.5 years. The median total serum levels of IgG, IgM, and IgA at diagnosis were 175, 18, and 17.8 mg/dL, respectively. The mean percentage of CD19+ B cells was 8.15%. Sinusitis (83%), pneumonia (83%), gastrointestinal infection (70%), and acute otitis media (49%) were the most common manifestations. Bronchiectasis was present in 51% of the patients, 44% manifested non-infectious chronic diarrhoea, and 70% experienced weight loss. Autoimmunity was present in 23% of the patients; haemolytic anaemia and autoimmune thrombocytopenic purpura were the most common presentations. Allergy was present in 30.2% of patients, with allergic rhinitis and asthma being the most frequent types. Two patients developed malignancy. All the patients received Intravenous immunoglobulin (IVIG) as a fundamental part of the treatment at a mean dose of 408 mg/kg. CONCLUSION: This is the first cohort of CVID reported in Mexico We found that infection diseases were the most frequent presentations at onset. Moreover, patients had an average diagnosis delay of twelve years and thus a major prevalence of bronchiectasis. We suggest performing an extended analysis of patients with CVID patients in other Latin American countries

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Clinical and immunological features of common variable immunodeficiency in Mexican patients.

BACKGROUND: Common variable immunodeficiency (CVID) is characterised by hypogammaglobulinaemia and a broad clinical spectrum, mainly showing recurrent bacterial infections accompanied sometimes by increased susceptibility to chronic lung disease, autoimmunity, and neoplastic diseases. OBJECTIVES: To evaluate the clinical and immunological characteristics of patients with CVID in Mexico. METHODS: This is a retrospective analysis of 43 patients with CVID from the Immunology Division of seven different reference centres in Mexico. Patients were diagnosed according to the diagnostic criteria of the European Society for Immunodeficiency Diseases. We collected demographics, clinical and immunological data from each patient and a statistical analysis was performed. RESULTS: There were 23 (53.5%) male and 20 (46.5%) female patients. Median age at onset of disease was 13.7 years, and median age at diagnosis was 19 years. Average delay in diagnosis was 12.5 years. The median total serum levels of IgG, IgM, and IgA at diagnosis were 175, 18, and 17.8mg/dL, respectively. The mean percentage of CD19+ B cells was 8.15%. Sinusitis (83%), pneumonia (83%), gastrointestinal infection (70%), and acute otitis media (49%) were the most common manifestations. Bronchiectasis was present in 51% of the patients, 44% manifested non-infectious chronic diarrhoea, and 70% experienced weight loss. Autoimmunity was present in 23% of the patients; haemolytic anaemia and autoimmune thrombocytopenic purpura were the most common presentations. Allergy was present in 30.2% of patients, with allergic rhinitis and asthma being the most frequent types. Two patients developed malignancy. All the patients received Intravenous immunoglobulin (IVIG) as a fundamental part of the treatment at a mean dose of 408mg/kg. CONCLUSION: This is the first cohort of CVID reported in Mexico We found that infection diseases were the most frequent presentations at onset. Moreover, patients had an average diagnosis delay of twelve years and thus a major prevalence of bronchiectasis. We suggest performing an extended analysis of patients with CVID patients in other Latin American countries.

The suprachiasmatic nucleus changes the daily activity of the arcuate nucleus α-MSH neurons in male rats.

Timing of metabolic processes is crucial for balanced physiology; many studies have shown the deleterious effects of untimely food intake. The basis for this might be an interaction between the arcuate nucleus (ARC) as the main integration site for metabolic information and the suprachiasmatic nucleus (SCN) as the master clock. Here we show in male rats that the SCN influences ARC daily neuronal activity by imposing a daily rhythm on the α-MSH neurons with a peak in neuronal activity at the end of the dark phase. Bilateral SCN lesions showed a complete disappearance of ARC neuronal rhythms and unilateral SCN lesions showed a decreased activation in the ARC at the lesioned side. Moreover light exposure during the dark phase inhibited ARC and α-MSH neuronal activity. The daily inhibition of ARC neuronal activity occurred in light-dark conditions as well as in dark-dark conditions, demonstrating the inhibitory effect to be mediated by increased SCN (subjective) day neuronal activity. Injections into the SCN with the neuronal tracer cholera toxin B showed that α-MSH neurons receive direct projections from the SCN. The present study demonstrates that the SCN activates and possibly also inhibits depending on the moment of the circadian cycle ARC α-MSH neurons via direct neuronal input. The persistence of these activity patterns in fasted animals demonstrates that this SCN-ARC interaction is not necessarily satiety associated but may support physiological functions associated with changes in the sleep-wake cycle.

Perspectiva genética de los rayos UV y las nuevas alternativas de protección solar / Genetics perspective of UV rays and new alternatives for sun protection

La radiación ultravioleta (UV), posee tres diferentes longitudes de onda: la UVA (315- 400 nm), la UVB (280-315 nm) y la UVC (100-280 nm), que impactan de diversas formas en la piel. Pueden causar "envejecimiento cutáneo", quemaduras y cánceres. En la actualidad se cuenta con múltiples alternativas de protección solar, que van desde los métodos físicos convencionales, hasta complejos mecanismos moleculares e inductores de reparación celular, como el Polypodium leucotomos. El propósito de esta revisión es describir las implicaciones, que tienen los rayos ultravioleta en los seres humanos expuestos a la luz solar y las alternativas de protección disponibles, así como citar los avances en foto-protección.

Ultraviolet (UV), has three different wavelengths: UVA (315-400 nm), UVB (280-315 nm) and UVC (100-280 nm), which impact in different ways on the skin of human beings, and may be responsible of skin aging, burns and cancers. Currently we have multiple sunscreen alternatives, ranging from conventional physical methods to complex molecular mechanisms and inducers of cell repair as Polypodium leucotomos. The purpose of this review is to show the implications of ultraviolet rays on human beings exposed to sunlight and the protection alternatives that are available and show what is to come in photo protection towards the future.

Perspectiva genética de los rayos UV y las nuevas alternativas de protección solar / Genetics perspective of UV rays and new alternatives for sun protection

La radiación ultravioleta (UV), posee tres diferentes longitudes de onda: la UVA (315- 400 nm), la UVB (280-315 nm) y la UVC (100-280 nm), que impactan de diversas formas en la piel. Pueden causar "envejecimiento cutáneo", quemaduras y cánceres. En la actualidad se cuenta con múltiples alternativas de protección solar, que van desde los métodos físicos convencionales, hasta complejos mecanismos moleculares e inductores de reparación celular, como el Polypodium leucotomos. El propósito de esta revisión es describir las implicaciones, que tienen los rayos ultravioleta en los seres humanos expuestos a la luz solar y las alternativas de protección disponibles, así como citar los avances en foto-protección.(AU)

Ultraviolet (UV), has three different wavelengths: UVA (315-400 nm), UVB (280-315 nm) and UVC (100-280 nm), which impact in different ways on the skin of human beings, and may be responsible of skin aging, burns and cancers. Currently we have multiple sunscreen alternatives, ranging from conventional physical methods to complex molecular mechanisms and inducers of cell repair as Polypodium leucotomos. The purpose of this review is to show the implications of ultraviolet rays on human beings exposed to sunlight and the protection alternatives that are available and show what is to come in photo protection towards the future.(AU)

Valor pronóstico de la respuesta patológica a la radioquimioterapia preoperatoria en el cáncer de recto bajo localmente avanzado / Prognostic value of pathological response to chemo radiotherapy of locally advanced low rectal cancer

Background: preoperative chemo radiotherapy improves the prognosis of locally advanced low rectal cancer and induces a pathological response in the tumor, which may have prognostic value. Aim: to assess the results of rectal cancer treatment according to the degree of pathological response of the tumor after chemo radiotherapy. Patients and Methods: all patients with a locally advanced rectal cancer located within 11 cm of the rectal margin, subjected to preoperative chemo radiotherapy followed by surgical treatment in a period of 13 years, were included. Pathological response was classified as complete, intermediate and poor. The tumor was staged according to TNM 2002 classification. Survival was analyzed with Kaplan Meier curves and Cox regression. Results: patients were followed for a mean of 50 months (range 18-156). Exclusive and global local relapse was observed in 3 and 9.6 percent of patients, respectively. Pathological response was complete in 13 patients (none died), intermediate in 23 (three died) and poor in 68 (22 died). Global five years survival was 74 percent. There was a concordance of 0.64 between survival and pathological response. The concordance between survival and TNM classification was 0.69. Conclusions: the pathological response of the tumor to chemo radiotherapy has a good concordance with prognosis, although it is not superior to the final pathological status.

Introducción: la radioquimioterapia (RQT) preoperatoria en el manejo del cáncer de recto bajo localmente avanzado mejora el control locoregional y es capaz de inducir en el tumor una respuesta patológica (RP) variable que podría tener implicancia pronóstica. El objetivo de este estudio es evaluar el grado de RP inducida por la RQT y comparar los resultados oncológicos de acuerdo al grado de RP luego de RQT neoadyuvante. Pacientes y Método: se incluyen todos los pacientes con un tumor de recto localmente avanzado por debajo de los 11 cm al margen anal sometidos a RQT seguida de cirugía radical con intención curativa en un período de 13 años. La RP fue categorizada como completa, intermedia y pobre. Para la etapificación patológica se utilizó la clasificación TNM 2002. Las curvas de sobrevida fueron estimadas según Kaplan-Meier, se empleó el modelo de regresión de Cox para el análisis multivariado y los coeficientes de concordancia fueron evaluados según el estadístico C de Harrell y el K de Gonen-Heller. Resultados: seguimiento promedio 50 meses (extremos 18-156). La recidiva local exclusiva fue 3 por ciento y la recidiva local global fue 9,6 por ciento. La RP fue completa en 13 pacientes (no fallecidos), Intermedia (ypT1-T2N0) en 23 (3 fallecidos) y fue pobre (ypT3/T4 y/o LN+) en 68 (22 fallecidos). Sobrevida global a 5 años 74 por ciento. Hubo una fuerte correlación entre la sobrevida y la RP, con un coeficiente de concordancia (0,64) ligeramente inferior al coeficiente de la etapificación patológica definitiva de acuerdo al TNM (0,69). Conclusión: el grado de RP es un marcador que se correlaciona bien con el pronóstico oncológico con un índice de concordancia de 0,69 cuando se asocia con la localización del tumor, aunque no supera al estadio patológico final que alcanza un valor de 0,74.

Inhibition of extracellular nucleotides hydrolysis intensifies the allergic bronchospasm. A novel protective role of ectonucleotidases.

BACKGROUND: Nucleotides released to the extracellular space stimulate purinergic receptors, and their effects are modulated by ectonucleotidases. The role of ATP in the allergic bronchospasm has been scantly studied. METHODS: We used several techniques (plethysmography, organ baths, confocal microscopy, RT-PCR, ATP measurement) to explore the role of nucleotides and ectonucleotidases in the allergic bronchospasm in guinea pigs. RESULTS: While allergenic challenge with a low-dose ovalbumin (OVA) only produced a small bronchospasm (~2-fold the basal lung resistance), previous inhibition of ectonucleotidases by ARL-67156 greatly intensified this response (~11-fold the basal lung resistance, with 44% mortality). Bronchoalveolar lavage fluid obtained during this bronchospasm contained increased ATP concentration. This potentiation was abolished by antagonism of purinergic receptors (suramin+RB2) or TXA2 receptor (SQ29548), or by intratracheal apyrase. In tracheal rings and lung parenchyma strips, OVA caused a concentration-dependent contraction. Suramin+RB2 or levamisole produced a significant rightward displacement of this response, and ARL-67156 did not modify it. Platelets stimulated with OVA released ATP. Confocal images of nonsensitized tracheas showed slight fluorescence for P2Y6 receptors in epithelium and none for P2Y4 . Sensitized animals showed strong fluorescence to both receptors and to alkaline phosphatase in the airway epithelium. This correlated with a large increment in mRNA for P2Y4 and P2Y6 receptors in sensitized animals. CONCLUSIONS: Nucleotides greatly potentiate the allergic bronchospasm when ectonucleotidases activity is diminished, and this effect is probably favored by the upregulation of P2Y4 and P2Y6 receptors in airway epithelium during sensitization. These results prompt for further research on these mechanisms in human asthma.

Amatoxin and phallotoxin composition in species of the genus Amanita in Colombia: a taxonomic perspective.

Some species in the genus Amanita have a great variety of toxic secondary metabolites. They are characterized macroscopically by having a white spore print and free gills, and microscopically by the presence of a divergent hymenophoral trama. Some species of Amanita present in Colombia were chemically characterized by analyzing their toxin composition using HPLC. Samples were collected in oak (Quercus humboldtii) and pine (Pinus radiata) forests. Twelve species were recovered, Amanita fuligineodisca, Amanita xylinivolva, Amanita flavoconia, Amanita rubescens, Amanita bisporigera, Amanita muscaria, Amanita humboldtii, Amanita sororcula, Amanita brunneolocularis, Amanita colombiana, Amanita citrina, Amanita porphyria as well as two unreported species. Results showed that most of the analyzed species have α -amanitin in concentrations ranging from 50 ppm to 6000 ppm. Concentrations of α-amanitin in the pileus were significantly greater than in the stipe. Phalloidin and phallacidin were only present in A. bisporigera. Chromatographic profiles are proposed as an additional taxonomic tool since specific peaks with similar retention times were conserved at the species level.

Biocompatibilidad de MTA-Angelus@ y cemento Portland blanco aditivado con cloruro de calcio y clorhexidina en tejido subcutáneo de ratas / Biocompatibility of MTA-Angelus® and White Portland cement with the addition of calcium chloride and chlorhexidine in subcutaneous tissue of rats

Objetivo: El propósito de este estudio fue determinar si la adición de cloruro de calcio (CaCl2) y clorhexidina (CHX) líquidos mexclados con MTA- Angelus@ y cemento Portland blanco (CBP) interfieren negativamente en el tejido subcutáneo de ratas. Material y Métodos: Se utilizaron 21 ratas tipo wistar (rattus novergicus) que se clasificaron en cuatro grupos experimentales, a los que se les implantaron 4 tubos de de dentina rellenos de MTA+CaCl2, MTA+-CHX, CPB+CaCl2 y CPB+CHX. Los animales fueron sacrificados a los 7,15 y 30 días por sobredosis, obteniéndose cortes microscópicos seriados de 5µm, tiñéndose con hematoxilina y eosina. Resultados: La prueba estadística de X2 de Pearson demostró que entre los grupos experimentales existió diferencia estadísticamente significativa, en los linfocitos a los 7 días, células gigantes multinucleadas a los 7 y 15 días, edema a los 7 días, proliferación fibroblastica y angioblástica a los 7 días. Conclusiones: Se concluye que los aditivos utilizados en ambos materiales no interfirieron respecto a la biocompatibilidad, por lo que sería factible su indicación en determinadas situaciones clínicas (AU)

Objective: The purpose of this study was to determine if the addiction of calcium chloride (CaCl2) and chlorhexidine (CHX) mixed the liquids with MT-Angelus@ and white Portland cement (CBP) do not interfere negatively in rats subcutaneous tissue. Material and Methodology: Twenty-one Wistar type rats (rattus novergicus) were used and were classified three experimental groups and one control group, to which the implanted 4 tubes of dentin filld with MTA+CaCl2, MTA+-CHX, CPB+CaCl2 y CPB+CHX. The animals were sacrifices by overdose on the 7th, 15th and the 30th day, getting microscopic shavings having the serial 5µn, dying its color with hematoxylin and cosin. Results: Pearson´s statistical X2 test showed that there was a significant statistical difference between the experimental groups, in the lymphocytes at 7 days, CGMi at 7 and 15 days, edema after 7 days, fibroblasts and angioblastical proliferation at 7 days. Conclusions: It is therefore concluded that the additives used in both materials do not interfere with the biocompatibility; they may be noticeable in clinical situations (AU)

Effects of 17beta-estradiol on the cytotoxicity of etoposide in a lung carcinoma cell line and its bioavailability in ovariectomized Sprague-Dawley rats.

BACKGROUND: The activity of steroid hormones for the efficacy of antineoplastic drugs used in lung cancer treatment has not been explored. We evaluated the influence of 17beta-estradiol on the cytotoxicity of etoposide in a lung cancer cell line (A-549) and determined systemic levels of etoposide in vivoafter pretreatment with this hormone. METHODS: The effect of 17beta-estradiol alone and combined with etoposide on cellular proliferation was evaluated. Blood levels of etoposide were studied in ovariectomized female rats previously treated with 17beta-estradiol. Etoposide levels were determined by high-performance liquid chromatography, and a pharmacokinetic analysis was performed. RESULTS: 17beta-Estradiol showed a tendency towards an increase in cellular proliferation but did not change the cytotoxic effect of etoposide. This in vivo study demonstrated that the blood levels of etoposide significantly decreased in the 17beta-estradiol-treated group. CONCLUSION: The clear reduction in the in vivo systemic levels of etoposide in the presence of 17beta-estradiol suggests a possible role of this hormone in drug resistance. However, as these data cannot be extrapolated to clinic situations, more research is necessary to understand the interaction between hormonal compounds and antineoplastic drugs.

Comparación del sellado apical de tres cementos endodónticos a base de resina (Estudio in vitro) / Comparison of the sealing apical of three resin-based root canal sealer (Study in vitro)

Objetivo. El propósito de este trabajo fue evaluar la capacidad de sellado apical de tres cementos endodóncicos a base de resina, Adseal®, EndoREZ ® y AH Plus®. Material y Métodos. Se utilizaron 68 raíces de dientes uniradiculares humanos extraídos, que se dividieron en 3 grupos experimentales de 20 cada uno y 8 para el control positivo y negativo. Se realizó tratamiento de conductos estandarizando la muestra 1 milímetro antes del ápice a un calibre 20 y obturando con la técnica de condensación latera y el cemento endodóntico correspondiente, posteriormente se incluyeron en una base de silicón, dejando libres 3 milímetros del tercio apical, que permanecieron en contacto con tinta china por 2 semanas a 37ºC. Resultados: Los resultados se obtuvieron por medio de observación directa, una vez que los dientes fueron diafanizados y la prueba estadística de Chi cuadrado (p<0,05) demostró una capacidad de sellado eficiente con el cemento Adseal® y AH Plus® presentaron un sellado apical similar en comparación con el cemento EndoREZ®. Conclusiones: Los cementos Adseal® y AH Plus® presentaron un sellado apical similar en comparación con el cemento EndoREZ® con diferencia estadísticamente significativa (AU)

Objective: The purpose in this work was to evaluate the ability of apical sealed in three endodontic cements Adseal®, EndoRez® and AH Plus® with resin base. Material and Methods: 68 extracted single root canal dentals organs humans were used, then divided in three experimental groups with 20 each one and 8 for the positive and negative control. Treatment in canals was performed standardizing the sample 1 millimeter before the apex at 20 gauge and obturing with lateral condensation technique and the endodontic cement corresponding, then were immersed in a silicon base, letting the apical third free for three millimeters, than remain in contact with Indian ink for 2 week at 37ºC. Results: The results were obtained by direct observation, once that the teeth were transparented and the square Chi statistical test (p<0,05) showed and efficient sealed capacity with ADSEAL® cement, that was similar with AH Plus® and inefficient in EndoREZ® cement. Conclusions; The apical seal of both ADSEAL and AH Plus were similar compared with EndoRez sealer (AU)