[Challenges in the management of analgesia and sedation in critically ill patients with COVID-19 in Chile]. / Desafíos en el manejo de la sedación, analgesia y bloqueo neuromuscular en el paciente crítico COVID-19 en Chile.

Approximately 5% of COVID-19 patients will have a severe disease requiring invasive or non-invasive mechanical ventilation. In this conditions, sedatives and analgesics are fundamental to promote tolerance, comfort and synchrony with the mechanical ventilator. High and unusual requirements for sedation, analgesics and neuromuscular blockers have been reported in these patients, contributing to prolonged exposure, a high rate of delirium and prolongation of mechanical ventilation. These factors, added to the progressive shortage of these drugs, a high demand for care and less capacity for personalized attention, have created an adverse scenario for their proper and rational use. This paper proposes different pharmacotherapeutic optimization strategies for a rational management of sedation, analgesia and neuromuscular block in critically ill patients with COVID-19, with the therapeutic alternatives available in Chile.

Desafíos en el manejo de la sedación, analgesia y bloqueo neuromuscular en el paciente crítico COVID-19 en Chile / Challenges in the management of analgesia and sedation in critically ill patients with COVID-19 in Chile

Approximately 5% of COVID-19 patients will have a severe disease requiring invasive or non-invasive mechanical ventilation. In this conditions, sedatives and analgesics are fundamental to promote tolerance, comfort and synchrony with the mechanical ventilator. High and unusual requirements for sedation, analgesics and neuromuscular blockers have been reported in these patients, contributing to prolonged exposure, a high rate of delirium and prolongation of mechanical ventilation. These factors, added to the progressive shortage of these drugs, a high demand for care and less capacity for personalized attention, have created an adverse scenario for their proper and rational use. This paper proposes different pharmacotherapeutic optimization strategies for a rational management of sedation, analgesia and neuromuscular block in critically ill patients with COVID-19, with the therapeutic alternatives available in Chile.

Cell-fate determination in Myxococcus xanthus development: Network dynamics and novel predictions.

Myxococcus xanthus is a myxobacterium that exhibits aggregation and cellular differentiation during the formation of fruiting bodies. Therefore, it has become a valuable model system to study the transition to multicellularity via cell aggregation. Although there is a vast set of experimental information for the development on M. xanthus, the dynamics behind cell-fate determination in this organism's development remain unclear. We integrate the currently available evidence in a mathematical network model that allows to test the set of molecular elements and regulatory interactions that are sufficient to account for the specification of the cell types that are observed in fruiting body formation. Besides providing a dynamic mechanism for cell-fate determination in the transition to multicellular aggregates of M. xanthus, this model enables the postulation of specific mechanisms behind some experimental observations for which no explanations have been provided, as well as new regulatory interactions that can be experimentally tested. Finally, this model constitutes a formal basis on which the continuously emerging data for this system can be integrated and interpreted.

An Evo-Devo Perspective on Multicellular Development of Myxobacteria.

The transition to multicellularity, recognized as one the major transitions in evolution, has occurred independently several times. While multicellular development has been extensively studied in zygotic organisms including plant and animal groups, just a few aggregative multicellular organisms have been employed as model organisms for the study of multicellularity. Studying different evolutionary origins and modes of multicellularity enables comparative analyses that can help identifying lineage-specific aspects of multicellular evolution and generic factors and mechanisms involved in the transition to multicellularity. Among aggregative multicellular organisms, myxobacteria are a valuable system to explore the particularities that aggregation confers to the evolution of multicellularity and mechanisms shared with clonal organisms. Moreover, myxobacteria species develop fruiting bodies displaying a range of morphological diversity. In this review, we aim to synthesize diverse lines of evidence regarding myxobacteria development and discuss them in the context of Evo-Devo concepts and approaches. First, we briefly describe the developmental processes in myxobacteria, present an updated comparative analysis of the genes involved in their developmental processes and discuss these and other lines of evidence in terms of co-option and developmental system drift, two concepts key to Evo-Devo studies. Next, as has been suggested from Evo-Devo approaches, we discuss how broad comparative studies and integration of diverse genetic, physicochemical, and environmental factors into experimental and theoretical models can further our understanding of myxobacterial development, phenotypic variation, and evolution.

Efecto antifúngico de diferentes concentraciones del extracto de Uncaria Tomentosa sobre Candida albicans: Estudio in vitro / Efeito antifúngico de diferentes concentrações hidroalcoólicas de UncariaTomentosa em Candida albicans: Estudo in vitro / Antifungal effect of different hydroalcoholic concentrations of Uncaria Tomentosa against Candida Albicans: In vitro study

En la actualidad el uso de la fitoterapia adquiere mayor demanda por parte de los pacientes y muchos profesionales de la salud debido a su fácil acceso, bajo costo y por presentar reacciones adversas mínimas. Objetivo: Determinar el efecto antifúngico de diferentes concentraciones hidroalcohólicas de la Uncaria tomentosa (UT) sobre Cándida albicans ATCC 10231, Mate-riales y métodos: Estudio experimental in vitro. La muestra estuvo constituida por 24 cajas petri con agar Sabourand, cada una con seis discos correspondientes a los 6 grupos de estudio siendo: G1 Nistatina de 21 ul (Control Positivo); G2 extracto hidroalcohólico de UT al 100%; G3 extracto hidroalcohólico de UT al 75%; G4 extracto hidroalcohólico de UT al 50%; G5 extracto hidroalcohólico de UT al 25%; G6 Alcohol etílico de 70° (Control negativo). Se elaboró un extracto hidroalcohólico por maceración, utilizando 75mg de planta micropulverizada y 250ml de alcohol etílico de 70°, se obtuvo 150ml de extracto, el mismo que fue diluido para obtener tres concentraciones secundarias al 75%, 50% y 25%. Los datos fueron procesados y analizados a través del test de ANOVA y de Bonferroni con un nivel de significancia de 5%. Resultados: Fue observado un halo de inhibición de 6.46 mm, 10.96 mm, 14.75 mm y 16,5 mm para los extractos hidroalcohólicos al 25%, 50%, 75% y 100% respectivamente. La Nistatina mostró un halo de inhibición de 23,42 mm y el alcohol etílico de 70° no obtuvo ningún efecto antifúngico. Fue observado diferencia estadísticamente significativa entre los grupos (< 0.001). Conclusión: El extrac-to hidroalcohólico al 100% de UT como la nistatina mostraron ser sensible, mientras que las concentraciones al 50% y 75% presentaron sensibilidad intermedia y la concentración al 25% fue resistente contra Candida albicans.

At present, the use of phytotherapy is in greater demand by patients and many health professionals due to its easy access, low cost and because of adverse reactions. Objective: To determine the antifungal effect of different hydroalcoholic concentrations of Uncaria tomentosa (UT) about Candida albicans ATCC 10231, Materials and methods: In vitro experimental study. The sample consisted of 24 box of petri dishes with Sabourand agar, each with six discs corresponding to the 6 study groups being: G1 Nistatin 21 ul (Positive Control); G2 hydroalcoholic extract of 100% UT; G3 hydroalcoholic extract of 75% UT; G4 hydroalcoholic extract of 50% UT; G5 hydroalcoholic extract of 25% UT; G6 70 ° Ethyl Alcohol (Negative Control) A hydroalcoholic extract was elaborated by maceration, using 75mg of micropulverized plant and 250ml of ethyl alcohol of 70 °, 150ml of extract was obtained, the same one that was diluted to obtain three secondary concentrations at 75%, 50% and 25%. The data were processed and analyzed through the ANOVA and Bonferroni test with a level of significance of 5%. Results: A halo of inhibition of 6.46 mm, 10.96 mm, 14.75 mm and 16.5 mm was observed for the hydroalcoholic extracts at 25%, 50%, 75% and 100% respectively. Nistatin showed a halo of inhibition of 23.42 mm and ethyl alcohol of 70 ° did not have any antifungal effect. A statistically significant difference was observed between the groups (<0.001). Conclusion: The 100% hydroalcoholic extract of UT such as nystatin showed to be sensitive, while the concentrations at 50% and 75% showed intermediate sensitivity and the concentration at 25% was resistant against Candida albicans.

Atualmente, o uso de fitoterapia está em maior demanda pelos pacientes e muitos profissionais da saúde devido ao seu fácil aces-so, baixo custo e por apresentar reações adversas mínimas. Objetivo: Determinar o efeito antifúngico de diferentes concentrações hidroalcoólicas de Uncaria tomentosa (UT) em Candida albicans ATCC 10231, Materiais e métodos: Estudo experimental in vitro. A amostra esteve constituída por 24 placas de Petri com agar Sabourand, cada uma com seis discos correspondentes aos 6 grupos de estudo: G1 Nistatina 21 ul (Controle Positivo); extracto hidroalcoólico G2 de 100% UT; extracto hidroalcoólico G3 de 75% UT; extracto hidroalcoólico G4 de 50% UT; extrato hidroalcoólico G5 de 25% UT; G6 álcool etílico a 70 ° (controle negativo). O extrato hidroalcoólico foi elaborado por maceração, utilizando 75 mg de planta micropulverizada e 250 ml de álcool etílico de 70 °, obteve-se 150 ml de extrato, o mesmo que foi diluído para obter três concentrações secundárias de 75%, 50% e 25%. Os dados foram processados e analisados através do teste ANOVA e Bonferroni com um nível de significância de 5%. Resultados: Observou-se um halo de inibição de 6,46 mm, 10,96 mm, 14,75 mm e 16,5 mm para os extratos hidroalcoólicos a 25%, 50%, 75% e 100%, respectivamente. A nistatina mostrou um halo de inibição de 23,42 mm e álcool etílico de 70 ° não teve nenhum efeito antifúngico. Observou-se diferença estatisticamente significativa entre os grupos (<0,001). Conclusão: O extracto hidroalcoólico 100% de UT assim como a nistatina mostraram ser sensíveis, enquanto as concentrações de 50% e 75% mostraram sensibilidade intermédia e a concentração de 25% foi resistente contra a Candida albicans.

Distinctive expression and functional regulation of the maize (Zea mays L.) TOR kinase ortholog.

TOR (Target of rapamycin) kinase is a central component of a signal transduction pathway that regulates cellular growth in response to nutrients, mitogens and growth factors in eukaryotes. Knowledge of the TOR pathway in plants is scarce, and reports in agronomical relevant plants are lacking. Previous studies indicate that Arabidopsis thaliana TOR (AtTOR) activity is resistant to rapamycin whereas maize TOR (ZmTOR) is not, suggesting that plants might have different regulation mechanisms for this signal transduction pathway. In the present work maize ZmTOR cDNA was identified and its expression regulation was analyzed during germination on different tissues at various stages of differentiation and by the main ZmTOR regulators. Our results show that ZmTOR contains all functional domains characteristic of metazoan TOR kinase. ZmTOR expression is highly regulated during germination, a critical plant development period, but not on other tissues of contrasting physiological characteristics. Bioinformatic analyses indicated that maize FKBP12 and rapamycin form a functional structure capable of targeting the ZmTOR protein, similar to other non-plant eukaryotes, further supporting its regulation by rapamycin (in contrast with the rapamycin insensitivity of Arabidopsis thaliana) and the conservation of rapamycin regulation through plant evolution.

Functional diversification of B MADS-box homeotic regulators of flower development: Adaptive evolution in protein-protein interaction domains after major gene duplication events.

B-class MADS-box genes have been shown to be the key regulators of petal and stamen specification in several eudicot model species such as Arabidopsis thaliana, Antirrhinum majus, and Petunia hybrida. Orthologs of these genes have been found across angiosperms and gymnosperms, and it is thought that the basic regulatory function of B proteins is conserved in seed plant lineages. The evolution of B genes is characterized by numerous duplications that might represent key elements fostering the functional diversification of duplicates with a deep impact on their role in the evolution of the floral developmental program. To evaluate this, we performed a rigorous statistical analysis with B gene sequences. Using maximum likelihood and Bayesian methods, we estimated molecular substitution rates and determined the selective regimes operating at each residue of B proteins. We implemented tests that rely on phylogenetic hypotheses and codon substitution models to detect significant differences in substitution rates (DSRs) and sites under positive adaptive selection (PS) in specific lineages before and after duplication events. With these methods, we identified several protein residues fixed by PS shortly after the origin of PISTILLATA-like and APETALA3-like lineages in angiosperms and shortly after the origin of the euAP3-like lineage in core eudicots, the 2 main B gene duplications. The residues inferred to have been fixed by positive selection lie mostly within the K domain of the protein, which is key to promote heterodimerization. Additionally, we used a likelihood method that accommodates DSRs among lineages to estimate duplication dates for AP3-PI and euAP3-TM6, calibrating with data from the fossil record. The dates obtained are consistent with angiosperm origins and diversification of core eudicots. Our results strongly suggest that novel multimer formation with other MADS proteins could have been crucial for the functional divergence of B MADS-box genes. We thus propose a mechanism of functional diversification and persistence of gene duplicates by the appearance of novel multimerization capabilities after duplications. Multimer formation in different combinations of regulatory proteins can be a mechanistic basis for the origin of novel regulatory functions and a gene regulatory mechanism for the appearance of morphological innovations.

Adaptive evolution in the Arabidopsis MADS-box gene family inferred from its complete resolved phylogeny.

Gene duplication is a substrate of evolution. However, the relative importance of positive selection versus relaxation of constraints in the functional divergence of gene copies is still under debate. Plant MADS-box genes encode transcriptional regulators key in various aspects of development and have undergone extensive duplications to form a large family. We recovered 104 MADS sequences from the Arabidopsis genome. Bayesian phylogenetic trees recover type II lineage as a monophyletic group and resolve a branching sequence of monophyletic groups within this lineage. The type I lineage is comprised of several divergent groups. However, contrasting gene structure and patterns of chromosomal distribution between type I and II sequences suggest that they had different evolutionary histories and support the placement of the root of the gene family between these two groups. Site-specific and site-branch analyses of positive Darwinian selection (PDS) suggest that different selection regimes could have affected the evolution of these lineages. We found evidence for PDS along the branch leading to flowering time genes that have a direct impact on plant fitness. Sites with high probabilities of having been under PDS were found in the MADS and K domains, suggesting that these played important roles in the acquisition of novel functions during MADS-box diversification. Detected sites are targets for further experimental analyses. We argue that adaptive changes in MADS-domain protein sequences have been important for their functional divergence, suggesting that changes within coding regions of transcriptional regulators have influenced phenotypic evolution of plants.

Lesiones pseudotumorales de la mucosa oral / Pseudotumorlike Lesiones of the oral mucosa

Analiza cada una de las terminologías empleadas, además las definiciones, etiologías, características clínicas e histopatológicas, diagnósticos presuntivos, diferenciales y definitivos así como también su pronóstico acompañadas de su respectivo plan de tratamiento, para cada una de las entidades patológicas consideradas como pseudotumorales de la mucosa oral. Además describimos un caso clínico-quirúrgico en el que podemos observar las características clínicas del épulis fisural y cada uno de los tiempos quirúrgicamente que son necesarios para su tratamiento...

Midazolam vs. ketamina por vía rectal como premedicación en anestesia pediátrica

En el hospital de SOLCA y Hospital Vozandes de Quito, Ecuador, se realizó una investigación prospectiva, comparativa y multicéntrica para elvaluar la premedicación anestésica con ketamina o midazolam, administrados por vía rectal, en veinte pacientes pediátricos. Los parámetros considerados fueron: tolerancia a la vía de administración, tranquilidad, sedación, respuesta al dolor, requerimiento de gases anestésicos, estabilidad hemodinámica, despertar y efectos secundarios. Se demuestra la ventaja de estos fármacos administrados por vía rectal en cuanto a su tolerancia, ambos resultados útiles para los fines propuestos, existen diferencias en cuanto al requerimiento de gases anestésicos y a la rapidez del despertar. Los efectos secundarios fueron mínimos e infrecuentes con ambas drogas.

Atar-analgesia en cirugía oncológica

La atar analgesia fue descrita como técnica anestésica que aprovechaba los efectos ataráxicos de una combinación medicamentosa a base de benzodiacepínicos, analgésicos y relajantes musculares. El resultado más importante de este procedimiento consiste en la pronta recuperación, pero la intubación endotraqueal y la descurarización son pasos imprescindibles. En el Instituto de la Sociedad de Lucha contra el Cáncer (S.O.L.C.A) de Quito-Ecuador, hemos implementado una técnica que aprovecha la capacidad analgésica del procedimiento, en la realización de 25 intervenciones quirúrgicas cortas. No hemos empleado relajantes musculares ni tampoco intubación endotraqueal. Todos los pacientes fueron sometidos a un protocolo prospectivo-comparativo. El grupo control fue sometido a anestesia raquídea o peridural. Los beneficios de nuestra técnica fueron superiores a los de este grupo.

Psiquiatria infanto - juvenil: taller de pediatría conductual / Infant-adolescent psychiatry: behavioral pediatry workshop

A workshop for training pediatricians and primary cary physicians in psychosocial aspects of pediatric care is described. It's application fdor three groups of doctors is assessed, through an objective knowledge test, and an instrument designed to measure changes in lcinical practice 6 months after. Results are considered promising. Implications for assistance and post graduate teaching are discussed

Técnicas de revascularización renal: experiencia en 70 pacientes / Surgical renal revascularization: results in 70 patients

Entre Mayo de 1982 y Agosto de 1989 realizamos revascularización quirúrgica en 94 riñones de 70 pacientes con enfermedad renovascular. (68,6% por ateroesclerosis, 11,4% por arteritis, 12,8% debida a displasia fibrosa). La indicación de revascularización, en más de 2/3 de los pacientes fue preservar o recuperar la función renal. 25 pts. requirieron reconstrucción aórtica simultánea. La técnica preferida fue el by-pass aorto renal (71,3%), aunque recientemente hemos preferido la técnica extra-anatómica. En el grupo de 59 pts. que tuvieron reconstrucción aórtica simultánea hubo 2 muertos (8%, una post cirugía y otra ocurrida meses más tarde). Sólo 1 pt. tuvo oclusión precoz, y la función renal mejoró o se estabilizó en la mayoría de los pts. En la actualidad la revascularización renal es el tratamiento de elección de la enfermedad ostial ateromatosa, debe ser considerada en pts. con enfermedad renovascular avanzada para preservar la función renal

Revascularización vertebral distal: requerimientos diagnósticos y aspectos técnicos / Distal vertebral revascularization: diagnostic requirements and technical aspects

Se presenta un caso de insuficiencia vascular cerebral por hipoperfusión, manifestada por síntomas deficitarios del hemisferio derecho, en un paciente portador de oclusión antigua de la carótida interna ipsilateral, y obstrucción de sus vías colaterales desde el área vertebrobasilar, por obstrucción completa de ambas arterias vertebrales. La demostración angiográfica de la permeabilidad distal de la arteria vertebral izquierda, y la perfusión del hemisferio derecho desde el territorio posterior, permitió practicar la revascularización mediante un puente subclaviovertebral con vena safena, a la altura de C1 - C2. La reconstrucción de la circulación posterior extracraneana, está indicada en casos seleccionados de insuficiencia vertebrobasilar, siendo posible efectuar la revascularización de la arteria vertebral hasta su posición distal (C1 - C2)