Estudio de la selectividad de flavonoides sobre la 12- y 15- Lipoxigenasa Humana (hLOX) a traves de “docking” y Simulacion Molecular Dirigida (SMD)

40 p.Este trabajo representa un estudio bibliográfico, teórico y práctico, realizado en el laboratorio de Simulación Molecular de la Facultad de Química y Biología de la Universidad de Santiago de Chile. En este establecimiento se cuenta con importante información de ensayos IC50 de alrededor 40 compuestos (flavonoides, flavonas, isoflavonoides, catecoles, etc) evaluando la actividad frente a las enzimas 12- y 15-hLOX. Estos datos son fundamentales para postular los objetivos y las hipótesis del trabajo, centrando el esfuerzo en las metodologías de “docking” y Simulación Molecular Dirigida.El objetivo principal del trabajo fue estudiar la selectividad de los diferentes compuestos, proponiendo una metodología valida como diseño racional de fármacos.Las metodologías utilizadas permiten comprobar la actividad y selectividad mostrada por los ensayos experimentales, permitiendo una futura modificación de los compuestos a través de técnicas de Bioinformática con el objetivo de potenciar la actividad de los mismo

Derivados de 3H-espiro1-benzofurano-2, 1’-ciclohexanos: inmunoestimulantes de uso veterinario

Cuatro 3H-spiro1-benzofuran-2, 1'-ciclohexanos se sintetizaron a partir de filifolinol, dos de los cuales son reportados por  primera vez. Se llevaron a cabo estudios de docking molecular para determinar in silico si estos derivados tienen actividad inmunoestimu-  lante similar a la reportada para filifolinol y su producto de oxidación, filifolinona. A través del estudio de las interacciones de estos com-  puestos con el heterodímero de la proteína presente en teleósteos TLR1-TLR2 se estableció que el filifolinol, 3'-cloruro de filifolinilo y  acetato de filifolinilo tienen interacciones similares con el heterodímero, lo que permite predecir que entre ellos tendrían una actividad simi-  lar, pero diferente a la de la filifolinona y filifolinano o que estos últimos actuarían por diferentes mecanismos

Molecular phylodynamics and protein modeling of infectious salmon anemia virus (ISAV)

<p>Abstract</p> <p>Background</p> <p>ISAV is a member of the <it>Orthomyxoviridae </it>family that affects salmonids with disastrous results. It was first detected in 1984 in Norway and from then on it has been reported in Canada, United States, Scotland and the Faroe Islands. Recently, an outbreak was recorded in Chile with negative consequences for the local fishing industry. However, few studies have examined available data to test hypotheses associated with the phylogeographic partitioning of the infecting viral population, the population dynamics, or the evolutionary rates and demographic history of ISAV. To explore these issues, we collected relevant sequences of genes coding for both surface proteins from Chile, Canada, and Norway. We addressed questions regarding their phylogenetic relationships, evolutionary rates, and demographic history using modern phylogenetic methods.</p> <p>Results</p> <p>A recombination breakpoint was consistently detected in the Hemagglutinin-Esterase (<it>he</it>) gene at either side of the Highly Polymorphic Region (HPR), whereas no recombination breakpoints were detected in Fusion protein (<it>f</it>) gene. Evolutionary relationships of ISAV revealed the 2007 Chilean outbreak group as a monophyletic clade for <it>f </it>that has a sister relationship to the Norwegian isolates. Their tMRCA is consistent with epidemiological data and demographic history was successfully recovered showing a profound bottleneck with further population expansion. Finally, selection analyses detected ongoing diversifying selection in <it>f </it>and <it>he </it>codons associated with protease processing and the HPR region, respectively.</p> <p>Conclusions</p> <p>Our results are consistent with the Norwegian origin hypothesis for the Chilean outbreak clade. In particular, ISAV HPR0 genotype is not the ancestor of all ISAV strains, although SK779/06 (HPR0) shares a common ancestor with the Chilean outbreak clade. Our analyses suggest that ISAV shows hallmarks typical of RNA viruses that can be exploited in epidemiological and surveillance settings. In addition, we hypothesized that genetic diversity of the HPR region is governed by recombination, probably due to template switching and that novel fusion gene proteolytic sites confer a selective advantage for the isolates that carry them. Additionally, protein modeling allowed us to relate the results of phylogenetic studies with the predicted structures. This study demonstrates that phylogenetic methods are important tools to predict future outbreaks of ISAV and other salmon pathogens.</p

Estudio de migracion de sondas solvatocromicas en un sistema micelar, mediante Simulacion de Dinamica Molecular

48 p.Cálculos de dinámica molecular fueron utilizadas para simular sistemas constituidos de una betaína solvatocrómica en una solución acuosa de un copolímero de tipo A-BA (“poloxámero”) formado por bloques de polietillenoxi (PEO) y polipropilenoxi (PPO), de fórmula (PEO)11-(PPO)16-(PEO)11 (Stuart y col., 2009). Tres betaínas fueron estudiadas en presencia de este copolímero, la N-metil-2,4-difenil-6-(4- oxifenil)piridinio (1a), la N-octil-2,4-difenil-6-(4- oxifenil)piridinio (1b) y la N-(3,5-difenil- 4-oxi)fenil-2,4,6-trifenilpiridinio (ET(30) de Reichardt) (2). Los resultados teóricos fueron comparados con el comportamiento espectral de estos compuestos solvatocrómicos en presencia de algunos poloxámeros. La diferencia en la respuesta espectral del par de betaínas 1a-b se había racionalizado en base a los diferentes grados de inserción de estas sondas dentro del núcleo hidrofóbico micelar. Esta interpretación fue ratificada por los resultados de las simulaciones teóricas, las cuales demostraron que las sondas con un nivel mayor de lipofilia penetran más profundamente dentro de la cavidad hidrofóbica de la micela con respecto a las sondas con un nivel menor de lipofília. En lo que se refiere a la betaína de Reichardt, evidencias espectrales habían sugerido la existencia de dos microambientes distintos para esta sonda, uno originado de la interacción de 2 con unímeros aislados en solución, y el otro correspondiendo al interior más hidrofóbico de la micela formada por varios unímeros (Anexo 10.2). La simulación de estos sistemas permitió definir más claramente estos ambientes y estimar el grado de solvatación acuosa de 2 dentro de la micela polimérica./ ABSTRACT: Molecular dynamics calculations were employed to mimic systems comprising an aqueous solution of a solvatochromic betaine in the presence of a copolymer of the type A-B-A ( “poloxamers”), formed of a polyethyleneoxy (PEO) and a polypropyleneoxy (PPO) block, with the formula (PEO)11-(PPO)16-(PEO)11 (Stuart et al.,2009). Three betaines were studied in the presence of this copolymer, the N-methyl- 2,4-diphenyl-6-(4-oxyphenyl)pyridinium (1a), the N-octyl-2,4- diphenyl-6-(4- oxyphenyl)pyridinium (1b) and the N-(3,5-diphenyl-4-oxyphenyl)- ,4,6- triphenylpyridinium (Reichardt’s ET(30) dye ) (2). The theoretical results were compared with the spectral behaviour of these solvatochromic compounds in the presence of some poloxamers. The differences in the spectral responses of the betaine pair 1a-b had been rationalized as arising from the different degrees of insertion of these probes inside the hydrophobic micellar nucleus. This interpretation found support in the results of the theoretical simulations, which showed that the probe with the greater lipophilicity was more deeply buried inside the hydrophobic cavity of the micelle than that with a smaller lipophilicity. As for Reichardt’s betaine, spectral evidences had suggested the existence of two different microenvironments for this probe, one originating from the interaction of 2 with isolated unimers in solution, and the other corresponding to the more hydrophobic micellar core, formed by aggregation of several unimers (Anexo 10.2). The simulation of these systems yielded a clearer picture of these environments, and allowed the estimation of the aqueous solvation of 2 inside the polymeric micelle

Modelamiento e identificación de sitios de interés de las subunidades de la Polimerasa y Nucleoproteína del virus de la Anemia Infecciosa del Salmón (ISAV)

75 p.El virus de la anemia infecciosa del salmón (ISAV), corresponde a un patógeno asociado a brotes con altos índices de mortalidad en Chile, provocando un fuerte impacto económico y social en un país que para el año 2006 logra ser el segundo productor mundial de carne de salmón Atlántico, luego de Noruega. El género Isavirus, pertenece a la familia Orthomixoviridae, agrupado junto a otros 4 géneros virales entre los que se encuentra Influenzavirus A. En este trabajo se caracterizaron las estructuras probables de los productos protéicos codificados por los segmentos 1, 2, 3 y 4 del genoma de ISAV para el aislado chileno 752, correspondientes a las subunidades análogas de PA, PB1, PB2 y NP de Influenzavirus A, logrando modelos tridimensionales para estas proteínas de ISAV, las cuales fueron estudiados mediante cálculos de acoplamiento molecular y dinámicas moleculares con moléculas de RNA, de modo de analizar sus comportamientos en relación a Influenzavirus A. Para las análogas de PA y NP, los resultados obtenidos fueron que para la región amino terminal de PA, se logró un acoplamiento en el cual se observa la interacción del RNA con la proteína, resultando en una ubicación distinta a lo obtenido con la proteína PA de Influenza. Mientras que para la proteína NP de ISAV, se obtuvieron resultados de acoplamiento con moléculas de RNA con características bastante similares a los logrados en Influenza, confirmando que estas proteínas poseerían características estructurales y funcionales en común. En cuanto a la oligomerización de las NPs de ISAV, luego de las dinámicas moleculares realizadas, se obtuvo un comportamiento similar a lo obtenido en Influenza, donde el lazo indicado como el responsable en al interacción NP-NP, presentó un movimiento acorde a lo reportado por otros autores en estudios cristalográficos realizados. Todos estos resultados abren la posibilidad de desarrollar estudios posteriores de mutaciones sitio-dirigidas para los residuos identificados en esta investigación./ABSTRACT: Infectious salmon anemia virus (ISAV) is a viral pathogen associated with outbreaks with high mortality rates in Chile, causing a strong economic and social impact in a country that by the year 2006 achieved to be the second largest producer of meat Atlantic salmon after Norway. Isavirus gender, belongs to Orthomixoviridae family, grouped together with other 4 gender virus among which is Influenzavirus A. Here probable structures were characterized for protein products codify by segments 1, 2, 3 and 4 of the ISAV of the Chilean ISAV 752 genome, subunits PA, PB1, PB2 and NP as in Influenzavirus A, making 3D models for these proteins in ISAV , which were studied by molecular docking and molecular dynamics calculations with RNA molecules, in order to analyze their behavior in relation to Influenza A. For analogue proteins PA and NP, the results shows in the amino terminal region of PA, it was possible a docking in which we see the interaction of RNA with the protein, resulting in a different location to that obtained with PA protein of Influenzavirus A. While for the ISAV NP protein, coupling results were obtained with RNA molecules with very similar characteristics to those achieved in Influenza, confirming that these proteins possess a common structural and functional characteristic. About for the Oligomerization of NPs in ISAV, there were performed molecular dynamics simulations, resulting in a similar behavior to that obtained in Influenzavirus A, where the tail loop indicated as responsible for the NP-NP interaction, presenting a movement according to those reported by other authors in crystallographic studies performed. These results open the possibility of developing further studies of site-directed mutations to residues identified in this investigation as important

Estudio preliminar de Isoflavonoides sintéticos como posibles inhibidores del Virus de la Anemia Infecciosa del Salmón (ISAV).

92 p.La anemia infecciosa del salmón (ISA, Infectious Salmon Anaemia) es una enfermedad que afecta principalmente al salmón del atlántico (Salmo salar), la cual puede aparecer con carácter sistémico y letal. Se pueden observar síntomas llamativos como branquias pálidas, exoftalmia (“ojos saltones”) y abdomen distendido, además pueden ocurrir hemorragias internas y petequias abdominales. El agente viral responsable de la enfermedad (ISA), pertenece a la familia Orthomixoviridae, tal como los virus Influenza A, B y C y Thogotovirus, siendo el virus ISA prototipo del nuevo género denominado ISAVIRUS. Dentro de los 8 segmentos que conforman su genoma de RNA de simple hebra de polaridad negativa segmentado, se sabe que el segmento 3 codifica para la nucleoproteína (NP), la cual tiene un importante rol en la transcripción y replicación genómica viral. Siendo Chile el segundo productor de Salmones a nivel mundial, el virus ISA ha generado grandes pérdidas económicas significando una grave amenaza. Las consecuencias en algunos casos, pueden ser imperceptibles, no obstante los casos de brotes severos, pueden llevar al cultivo de salmones hasta un porcentaje de mortalidad acumulado del 90–100%. Debido a que, hasta la fecha no existe tratamiento eficaz contra el virus de la anemia infecciosa del salmón y las vacunas desarrolladas no presentan una protección adecuada, es necesaria la búsqueda de nuevos antivirales, los cuales ayuden a detener este problema, antes de que la industria se vea gravemente afectada. Debido a la similitud estructural con su homólogo viral Influenza A, este último es utilizado como modelo de estudio en este trabajo para el desarrollo de antivirales candidatos para ISAV. Esta tesis describe la búsqueda de compuestos que tengan similitudes estructura/actividad, con compuestos reportados para virus de influenza A, con la finalidad de encontrar aquellos que actúen como inhibidores para ISA en ensayos ex vivo. Los compuestos que se estudiarán provienen de la familia de los isoflavonoides. El interés de estos compuestos radica en sus variadas actividades farmacológicas reportadas, tales como antiinflamatorios, antioxidantes, anti cancerígenos y antivirales entre otros./ABSTRACT: Infectious salmon anemia (ISA) is a disease that mainly affects Atlantic salmon (Salmo salar), which may occur with systemic and lethal character. It can be see dramatic symptoms like pale gills, exophthalmos ("googly eyes ") and distended abdomen, furtherinternal bleeding and abdominal petechiae can occur. The viral agent responsible for the disease, belongs to the Orthomixoviridae family such as Influenza A, B and C and Thogoto virus, being ISA virus the prototype of new genus called Isavirus. Within the 8 genome segments of singlestranded RNA of negative polarity, it is known that segment 3 encodes for the nucleoprotein (NP) , which plays an important role in viral genomic replication and transcription. Being Chile the second largest producer of salmon in the world, the ISA virus has generated huge economic losses signifying a serious threat. The consequences in some cases, may be imperceptible, however cases of severe outbreaks can lead to farmed salmon to a cumulative 90- 100% percentage of mortality. Because, to date there is no effective treatment for ISAV virus and vaccine developed have not adequate protection, it is necessary to search for new antiviral drugs, which help stopthis problem before the industry will be severely affected. Due to the structural similarity to its viral homolog, Influenza A, the latter is used as a study model for developing potential antiviral for ISAV. This thesis describes the search of compounds that have structure / activity similarities with compounds with reported activity for influenza A virus , in order to find those that, in ex vivo assays act as inhibitors for ISA virus. The compound to be studied comes from the isoflavones family. The interest in these compounds lies in their various pharmacological activities reported, such as anti-inflammatory, antioxidant, anticancer and antiviral among others

El impacto de la pandemia de COVID-19 en la salud mental de los trabajadores de la salud en Chile: datos iniciales de The Health Care Workers Study

Background: Healthcare workers’ mental health was affected by SARS-CoV-2 pandemic. Aim: To evaluate healthcare workers’ mental health and its associated factors during the pandemic in Chile. Material and Methods: An online self-reported questionnaire was designed including the Goldberg Health Questionnaire, the Patient Health Questionnaire, (PHQ-9), and the Columbia-Suicide Severity Rating Scale among other questions. It was sent to 28,038 healthcare workers. Results: The questionnaire was answered by 1,934 participants, with a median age of 38 years (74% women). Seventy five percent were professionals, and 48% worked at a hospital. Fifty nine percent of respondents had a risk of having a mental health disorder, and 73% had depressive symptoms. Significant associations were found with sex, workplace, and some of the relevant experiences during the pandemic. Fifty one percent reported the need for mental health support, and 38% of them received it. Conclusions: There is a high percentage of health workers with symptoms of psychological distress, depression, and suicidal ideas. The gender approach is essential to understand the important differences found. Many health workers who required mental health care did not seek or received it

[Impact of COVID-19 pandemic on the mental health of healthcare workers].

BACKGROUND: Healthcare workers' mental health was affected by SARS-CoV-2 pandemic. AIM: To evaluate healthcare workers' mental health and its associated factors during the pandemic in Chile. MATERIAL AND METHODS: An online self-reported questionnaire was designed including the Goldberg Health Questionnaire, the Patient Health Questionnaire, (PHQ-9), and the Columbia-Suicide Severity Rating Scale among other questions. It was sent to 28,038 healthcare workers. RESULTS: The questionnaire was answered by 1,934 participants, with a median age of 38 years (74% women). Seventy five percent were professionals, and 48% worked at a hospital. Fifty nine percent of respondents had a risk of having a mental health disorder, and 73% had depressive symptoms. Significant associations were found with sex, workplace, and some of the relevant experiences during the pandemic. Fifty one percent reported the need for mental health support, and 38% of them received it. CONCLUSIONS: There is a high percentage of health workers with symptoms of psychological distress, depression, and suicidal ideas. The gender approach is essential to understand the important differences found. Many health workers who required mental health care did not seek or received it