Centrolene savagei

Number of Pages: 11Geological SciencesIntegrative Biolog

Evaluación del Rendimiento, Composición y Actividad Antioxidante de Aceite de Semillas de Mora (Rubus glaucus) Extraído con CO2 Supercrítico

En este trabajo se estudió el efecto de los parámetros de extracción del aceite de semillas de mora (Rubus glaucus), utilizando CO2 supercrítico como solvente. Se evaluaron diferentes condiciones de presión y temperatura, que permitieron analizar el rendimiento, la composición y la actividad antioxidante del producto extraído. La identificación de los componentes del aceite se realizó a través de cromatografía de gases y la actividad antioxidante se determinó aplicando el método de ABTS. El rendimiento más alto fue 14.5%, obtenido bajo las mejores condiciones de trabajo: 350 bar de presión y 60°C de temperatura. El aceite proveniente de semillas de R. glaucus se caracteriza por contener un 96% de ácidos grasos insaturados, de los cuales el ácido linoléico es el más abundante (61.6%) y por la presencia de sustancias como β-sitosterol, 24-metil-cicloartanol, α-tocoferol, γ-tocoferol, δ-tocoferol, además de una capacidad antioxidante equivalente al trolox de 604 µmol/100 g aceite

Diversidad genética de aislados de pseudomonas aeruginosa multirresistentes portadores de los genes blavim-2 y blakpc-2 que se propagan en diferentes entornos genéticos en colombia

Pseudomonas aeruginosa es un patógeno Gram negativo oportunista con un aumento de la frecuencia de infecciones causadas por cepas multirresistentes (MDR) y extremadamente resistentes (XDR), lo que limita las opciones terapéuticas disponibles. La resistencia más problemática es la adquisición y producción de carbapenemasas, como las metalo-β-lactamasas codificadas por integrones de Verona (VIM), las más frecuentes y extendidas, y las carbapenemasas de Klebsiella pneumoniae (KPC), que no han dejado de propagarse en la última década. Su diseminación está ligada a su localización en elementos genéticos móviles (EGM). En Colombia, VIM y KPC han venido aumentando en su frecuencia mostrando una importante diseminación exitosa. En este artículo, caracterizamos molecularmente y analizamos el contexto genético de blaVIM y blaKPC en aislamientos de P. aeruginosa resistente a carbapenemasas (CRPA) provenientes de pacientes infectados y colonizados en dos hospitales de tercer nivel de atención, uno en Medellín y el otro en un municipio cercano a Medellín, ambas zonas con alta endemicidad de carbapenemasas en Colombia (2013-2015). Usando secuenciación del genoma completo (WGS), identificamos una notable variedad de antecedentes genéticos en estos aislados de P. aeruginosa MDR portadores de blaKPC-2 y blaVIM-2. Se observó una diversidad de integradores de clase 1 en los aislados de P. aeruginosa MDR. Hubo diversidad de integrones de clase 1 y variaciones en los casetes génicos asociados a blaVIM-2, así como un posible evento de diseminación de blaKPC-2 mediado por un plásmido que contenía parte de Tn4401b en un caso de infección. La diseminación de blaVIM-2 y blaKPC-2 en P. aeruginosa en esta área en Colombia ha estado fuertemente influenciada por clones internacionales exitosos, portadores de estos genes y determinantes adicionales de resistencia en MGEs, acompañados de reordenamiento génico bajo una presión de selección antimicrobiana. Estos hallazgos enfatizan la necesidad de implementar estrategias de control basadas en el uso racional de antibióticos.Pseudomonas aeruginosa is an opportunistic Gram-negative pathogen with an increase in the frequency of infections caused by multidrug resistant (MDR) and extensively drug resistant (XDR) strains, limiting the available therapeutic options. The most troublesome resistance is the acquisition and production of carbapenemases such as Verona integron-encoded metallo-β-lactamases (VIM), the most frequent and widespread, and the Klebsiella pneumoniae carbapenemases (KPC), which has continuously spread in the last decade. Its dissemination is linked to their location on mobile genetic elements (MGEs). In Colombia, VIM and KPC have been increasing in its frequency showing major successful dissemination. In this article, we molecularly characterized and analyzed the genetic context of blaVIM and blaKPC in carbapenem-resistant P. aeruginosa (CRPA) isolates from infected and colonized patients in two tertiary-care hospitals, one in Medellín and the other in a municipality close to Medellín, both areas with high carbapenemase endemicity in Colombia (2013–2015). Using whole-genome sequencing (WGS), we identified a remarkable variety of genetic backgrounds in these MDR P. aeruginosa isolates carrying blaKPC–2 and blaVIM–2. There were a diversity of class 1 integron and variations in the gene cassettes associated to blaVIM–2, as well as a possible event of spread of blaKPC–2 mediated by a plasmid that contained part of Tn4401b in one infection case. The dissemination of blaVIM–2 and blaKPC–2 in P. aeruginosa in this area in Colombia has been strongly influenced by successful international clones, carrying these genes and additional determinants of resistance on MGEs, accompanied by gene rearrangement under an antimicrobial selection pressure. These findings emphasize the need to implement control strategies based on rational antibiotic us

Functional gallic acid-based dendrimers as synthetic nanotools to remodel amyloid-β-42 into noncytotoxic forms

The self-assembly of amyloid-β (Aβ) generates cytotoxic oligomers linked to the onset and progression of Alzheimer’s disease (AD). As many fundamental molecular pathways that control Aβ aggregation are yet to be unraveled, an important strategy to control Aβ cytotoxicity is the development of bioactive synthetic nanotools capable of interacting with the heterogeneous ensemble of Aβ species and remodel them into noncytotoxic forms. Herein, the synthesis of nanosized, functional gallic acid (Ga)-based dendrimers with a precise number of Ga at their surface is described. It is shown that these Ga-terminated dendrimers interact by H-bonding with monomeric/oligomeric Aβ species at their Glu, Ala, and Asp residues, promoting their remodeling into noncytotoxic aggregates in a process controlled by the Ga units. The multivalent presentation of Ga on the dendrimer surface enhances their ability to interact with Aβ, inhibiting the primary and secondary nucleation of Aβ fibrillization and disrupting the Aβ preformed fibrils.The authors acknowledge the financial support from the EC (FORECAST-668983), “Programa Operacional Regional do Norte”, “Fundo Social Europeu”, Norte2020 TERM&SC, for the PhD grant NORTE-08-5369-FSE-000044, the Spanish Ministry of Science and Innovation (RTI2018-102212-B-I00), the Xunta de Galicia (ED431C 2018/30; Centro singular de investigación de Galicia accreditation 2019−2022, ED431G 2019/03), European Regional Development Fund-ERDF, and the Galician Supercomputing Centre (CESGA) and the MAT2016-80266-R of the Spanish Ministry of Science and Innovation

Valoración microclimática de propuestas de urbanización sustentable : El caso del piedemonte del área metropolitana de Mendoza

El desarrollo urbano del piedemonte del Área Metropolitana de Mendoza ha continuado con las  características  urbanas  de llanura, generando un impacto negativo sobre los  perfiles higrotérmicos  del sector. Por ello, se diseñaron un conjunto de esquemas  urbanos  orientados  a disminuir los  riesgos  naturales  y  preservar las  características  ambientales  del sector, con el fin de mitigar el efecto de las urbanizaciones sobre el microclima. Para verificar si las propuestas mejoran el comportamiento térmico de las  urbanizaciones  actuales, un esquema urbano existente y  dos esquemas de urbanizaciones adaptadas a condiciones de piedemonte fueron simulados utilizando el software ENVI-met. Los  resultados  muestran que el esquema urbano orgánico de tipo lineal con espacio verde público posee el mejor comportamiento térmico, logrando una  disminución de la temperatura máxima del aire de hasta 1,5°C con respecto al esquema urbano existente. Además, se pone en relevancia los beneficios de utilizar ENVI-met como herramienta de simulación, dado que se verifica que el modelo reproduce de manera confiable los principales procesos de cambio atmosféricos que afectan al microclima, dando valor a las predicciones que derivan de su uso. Esto facilita la labor de los  planificadores  urbanos  optimizando los  procesos  de toma de decisión durante la etapa de diseño.Urban development in the hillsides of the Metropolitan Area of Mendoza has continued urban characteristics of plain, generating a negative impact on the hygrothermal profiles of the sector. For this reason, a set of urban schemes were designed aimed at reducing natural hazards and preserving the environmental characteristics of the sector, in order to mitigate the effect of urbanization on the microclimate. To verify whether the proposals improve the thermal behavior of current developments, an existing urban scheme and two urbanization schemes adapted to hillside conditions were simulated using the ENVI-met software. The results show that the organic lineal urban scheme type with public green space has the best thermal behavior, achieving a decrease in the maximum air temperature of up to 1.5 °C with respect to the existing urban scheme. Also, the benefits of using ENVI-met as a simulation tool are highlighted, since it is verified that the model reliably reproduces the main atmospheric change processes that affect the microclimate, giving value to the predictions derived from its use. This facilitates the work of urban planners optimizing decision-making processes during the design stage.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Detection of virulence-associated genes in pathogenic and commensal avian Escherichia coli isolates

Poultry colibacillosis due to Avian Pathogenic Escherichia coli (APEC) is responsible for several extra-intestinal pathological conditions, leading to serious economic damage in poultry production. The most commonly associated pathologies are airsacculitis, colisepticemia, and cellulitis in broiler chickens, and salpingitis and peritonitis in broiler breeders. In this work a total of 66 strains isolated from dead broiler breeders affected with colibacillosis and 61 strains from healthy broilers were studied. Strains from broiler breeders were typified with serogroups O2, O18, and O78, which are mainly associated with disease. The serogroup O78 was the most prevalent (58%). All the strains were checked for the presence of 11 virulence genes: 1) arginine succinyltransferase A (astA); ii) E. coli hemeutilization protein A (chuA); iii) colicin V A/B (cvaA/B); iv) fimbriae mannose-binding type 1 (fimC); v) ferric yersiniabactin uptake A (fyuA); vi) iron-repressible high-molecular-weight proteins 2 (irp2); vii) increased serum survival (iss); viii) iron-uptake systems of E. coli D (iucD); ix) pielonefritis associated to pili C (papC); x) temperature sensitive haemaglutinin (tsh), and xi) vacuolating autotransporter toxin (vat), by Multiplex-PCR. The results showed that all genes are present in both commensal and pathogenic E. coli strains. The iron uptake-related genes and the serum survival gene were more prevalent among APEC. The adhesin genes, except tsh, and the toxin genes, except astA, were also more prevalent among APEC isolates. Except for astA and tsh, APEC strains harbored the majority of the virulence-associated genes studied and fimC was the most prevalent gene, detected in 96.97 and 88.52% of APEC and AFEC strains, respectively. Possession of more than one iron transport system seems to play an important role on APEC survival

Metabolic disruption of gold nanospheres, nanostars and nanorods in human metastatic prostate cancer cells

Nanomaterials offer a broad spectrum of applications in biomedicine. The shapes of gold nanoparticles could modulate tumor cell behavior. Spherical (AuNPsp), stars (AuNPst) and rods (AuNPr) shapes of polyethylene glycol coated-gold nanoparticles (AuNPs-PEG) were synthesized. Metabolic activity, cellular proliferation, and reactive oxygen species (ROS) were measured and the impact of AuNPs-PEG in metabolic enzymes function was evaluated by RT-qPCR in PC3, DU145, and LNCaP prostate cancer cells. All AuNPs were internalized, and the different morphologies of AuNPs showed to be an essential modulator of metabolic activity. For PC3 and DU145, the metabolic activity of AuNPs was found to rank in the following order from lowest to highest: AuNPsp-PEG, AuNPst-PEG, and AuNPr-PEG. Regarding LNCaP cells, the AuNPst-PEG were less toxic, followed by AuNPsp-PEG and AuNPr-PEG, but it seems not to be dose-dependent. The proliferation was lower in AuNPr-PEG in PC3 and DU145 cells but was stimulated around 10% in most conditions (0.001–0.1 mM) in LNCaP cells (not statistically significant). For 1 mM, LNCaP cells showed a significant decrease in proliferation only for AuNPr-PEG. The outcomes of the current study demonstrated that different AuNPs conformations influence cell behavior, and the correct size and shape must be chosen considering its final application in the field of nanomedicine.The author is grateful for the financial support of Foundation for Science and Technology (FCT) through project reference—2022.09032.PTDC and also to FCT through COMPETE to the project NORTE-01-0145-FEDER-024325.info:eu-repo/semantics/publishedVersio

Effects of oxidative stress during human and animal reproductions: A review

Given its high ability to damage important cellular components (lipids, proteins and deoxyribonucleic acid), oxidative stress is now recognized as one of the most common mechanisms associated with development of a variety of diseases and natural events such as pregnancy. During reproduction period, there is a change in the pro-oxidant and antioxidant balance due to the body and circulation modifications that are inherent to the pregnancy process. The present paper discusses the role of oxidative stress on the reproduction process. More effective defense strategies are needed to decrease the deleterious effects of oxidative-stress-induced gestation. This approach could be achieved by antioxidant status alteration. Further clinical and experimental studies are needed for better understanding of oxidative stress mechanism and the impact of antioxidant supplementation on reproduction