Evolutionary Dynamics of Multigene Families in Triportheus (Characiformes, Triportheidae): A Transposon Mediated Mechanism?

Triportheus (Characiformes, Triportheidae) is a freshwater fish genus with 18 valid species. These fishes are widely distributed in the major river drainages of South America, having commercial importance in the fishing market, mainly in the Amazon basin. This genus has diverged recently in a complex process of speciation carried out in different river basins. The use of repetitive sequences is suitable to trace the genomic reorganizations occured along the speciation process. In this work, the 5S rDNA multigene family has been characterized at molecular and phylogenetic level. The results showed that other multigene family has been found within the non-transcribed spacer (NTS): the U1 snRNA gene. Double-FISH with 5S and U1 probes were also performed, confirming the close linkage between these two multigene families. Moreover, evidences of different transposable elements (TE) were detected within the spacer, thus suggesting a transposon-mediated mechanism of 5S-U1 evolutionary pathway in this genus. Phylogenetic analysis demonstrated a species-specific grouping, except for Triportheus pantanensis, Triportheus aff. rotundatus and Triportheus trifurcatus. The evolutionary model of the 5S rDNA in Triportheus species has been discussed. In addition, the results suggest new clues for the speciation and evolutionary trend in these species, which could be suitable to use in other Characiformes species

Protection by ozone preconditioning is mediated by the antioxidant system in cisplatin-induced nephrotoxicity in rats.

BACKGROUND: Acute renal failure is a dose-limiting factor of cisplatin chemotherapy. Here, we show the protective effect of ozone oxidative preconditioning against cisplatin-induced renal dysfunction in rats. Ozone oxidative preconditioning is a prophylactic approach, which favors the antioxidant-pro-oxidant balance for preservation of the cell redox state by increasing antioxidant endogenous systems in various in vivo and in vitro experimental models. AIMS: To analyze the protective role of ozone oxidative preconditioning against cisplatin-induced nephrotoxicity. METHODS: Male Sprague-Dawley rats were pretreated with 15 intrarectal applications of ozone/oxygen mixture at 0.36, 0.72, 1.1, 1.8 and 2.5 mg/kg before cisplatin intraperitoneal injection (6 mg/kg). Serum and kidneys were extracted and analyzed 5 days after cisplatin treatment for determinations of the renal content of glutathione, thiobarbituric acid-reactive substances, renal concentration and enzymatic activities of catalase, superoxide dismutase and glutathione peroxidase. RESULTS: Ozone pretreatment prevented the increase in serum creatinine levels, the glutathione depletion and the inhibition of superoxide dismutase, catalase and glutathione peroxidase activities induced by cisplatin in the rat kidney. Also, the renal content of thiobarbituric acid-reactive substances was decreased by ozone therapy. These protective effects of ozone were dose dependent. CONCLUSIONS: Intrarectal ozone therapy prevented effectively the renal antioxidant unbalance induced by cisplatin treatment

Effects of Ozone Oxidative Preconditioning on TNF-α Release and Antioxidant-Prooxidant Intracellular Balance in Mice During Endotoxic Shock

Ozone oxidative preconditioning is a prophylactic approach, which favors the antioxidant-prooxidant balance for preservation of cell redox state by the increase of antioxidant endogenous systems in both in vivo and in vitro experimental models. Our aim is to analyze the effect of ozone oxidative preconditioning on serum TNF-α levels and as a modulator of oxidative stress on hepatic tissue in endotoxic shock model (mice treated with lipopolysaccharide (LPS)). Ozone/oxygen gaseous mixture which was administered intraperitoneally (0.2, 0.4, and 1.2 mg/kg) once daily for five days before LPS (0.1 mg/kg, intraperitoneal). TNF-α was measured by cytotoxicity on L-929 cells. Biochemical parameters such as thiobarbituric acid reactive substances (TBARS), enzymatic activity of catalase, glutathione peroxidase, and glutathione-S transferase were measured in hepatic tissue. One hour after LPS injection there was a significant increase in TNF-α levels in mouse serum. Ozone/oxygen gaseous mixture reduced serum TNF-α levels in a dose-dependent manner. Statistically significant decreases in TNF-α levels after LPS injection were observed in mice pretreated with ozone intraperitoneal applications at 0.2 (78%), 0.4 (98%), and 1.2 (99%). Also a significant increase in TBARS content was observed in the hepatic tissue of LPS-treated mice, whereas enzymatic activity of glutathion-S transferase and glutathione peroxidase was decreased. However in ozone-treated animals a significant decrease in TBARS content was appreciated as well as an increase in the activity of antioxidant enzymes. These results indicate that ozone oxidative preconditioning exerts inhibitory effects on TNF-α production and on the other hand it exerts influence on the antioxidant-prooxidant balance for preservation of cell redox state by the increase of endogenous antioxidant systems

Achromobacter marplatensis sp. nov., isolated from a pentachlorophenol contaminated soil

A polyphasic taxonomic approach was applied to the study of a Gram-negative bacterium (B2T) isolated from soil by selective enrichment with pentachlorophenol. 16S rRNA gene sequence analysis of strain B2T showed that the strain belongs to the genus Achromobacter within the Betaproteobacteria. The 16S rRNA gene sequence displayed more than 99 % similarity to the sequences of the type strains of all species of Achromobacter, with the highest sequence similarity to those of Achromobacter spanius CCM 7183T and A. piechaudii CCM 2986T (99.8 %). On the basis of phylogenetic analysis, genomic DNA–DNA relatedness and phenotypic characteristics, including chemotaxonomic (cellular fatty acid profile) analysis, a novel species is proposed, Achromobacter marplatensis sp. nov., with the type strain B2T ( = CCM 7608T = CCUG 56371T = CECT 7342T)

Sex-Specific Regulation of miR-29b in the Myocardium Under Pressure Overload is Associated with Differential Molecular, Structural and Functional Remodeling Patterns in Mice and Patients with Aortic Stenosis

Pressure overload in patients with aortic stenosis (AS) induces an adverse remodeling of the left ventricle (LV) in a sex-specific manner. We assessed whether a sex-specific miR-29b dysregulation underlies this sex-biased remodeling pattern, as has been described in liver fibrosis. We studied mice with transverse aortic constriction (TAC) and patients with AS. miR-29b was determined in the LV (mice, patients) and plasma (patients). Expression of remodeling-related markers and histological fibrosis were determined in mouse LV. Echocardiographic morpho-functional parameters were evaluated at baseline and post-TAC in mice, and preoperatively and 1 year after aortic valve replacement (AVR) in patients with AS. In mice, miR-29b LV regulation was opposite in TAC-males (down-regulation) and TAC-females (up-regulation). The subsequent changes in miR-29b targets (collagens and GSK-3?) revealed a remodeling pattern that was more fibrotic in males but more hypertrophic in females. Both systolic and diastolic cardiac functions deteriorated more in TAC-females, thus suggesting a detrimental role of miR-29b in females, but was protective in the LV under pressure overload in males. Clinically, miR-29b in controls and patients with AS reproduced most of the sexually dimorphic features observed in mice. In women with AS, the preoperative plasma expression of miR-29b paralleled the severity of hypertrophy and was a significant negative predictor of reverse remodeling after AVR; therefore, it may have potential value as a prognostic biomarker

Evolutionary Dynamics of rDNAs and U2 Small Nuclear DNAs in Triportheus (Characiformes, Triportheidae): High Variability and Particular Syntenic Organization.

Agradecer a ª Mary Ann Liebert, Inc.Las familias multigénicas corresponden a un grupo de genes repetidos en tándem, mostrando una enorme diversidad tanto en el número de unidades como en la organización genómica. En los peces, a diferencia del ADNr que ha sido bien explorado en estudios citogenéticos, los genes del ARN nuclear pequeño (ARNsn) U2 están poco investigados en cuanto a su localización cromosómica. Todas las especies de Triportheus (Characiformes, Triportheidae) estudiadas hasta ahora llevan un sistema de cromosomas sexuales ZZ/ZW, donde el cromosoma W contiene un enorme cistrón de ADNr 18S. En algunas especies también se verificó la organización sinténica de los ADNr en los autosomas. Para explorar esta organización particular, realizamos una hibridación in situ con fluorescencia de tres colores utilizando los genes 5S, 18S rDNA y U2 snRNA como sondas en ocho especies de Triportheus. Este trabajo representa el primero que analiza la distribución cromosómica de genes de ARNsn U2 en genomas de Triportheidae. La variabilidad en el número de grupos de ADNr y las sintenias divergentes de estas tres familias multigénicas ponen en evidencia su dinamismo evolutivo, revelando una organización mucho más compleja de estos genes de lo que se suponía anteriormente para especies estrechamente relacionadas. Nuestro estudio también proporciona datos adicionales sobre la acumulación de secuencias repetitivas en el cromosoma específico del sexo. Además, también se revisa la organización cromosómica de los snDNA U2 entre especies de peces. ​Multigene families correspond to a group of genes tandemly repeated, showing enormous diversity in both number of units and genomic organization. In fishes, unlike rDNAs that have been well explored in cytogenetic studies, U2 small nuclear RNA (snRNA) genes are poorly investigated concerning their chromosomal localization. All Triportheus species (Characiformes, Triportheidae) studied so far carry a ZZ/ZW sex chromosomes system, where the W chromosome contains a huge 18S rDNA cistron. In some species the syntenic organization of rDNAs on autosomes was also verified. To explore this particular organization, we performed three-color-fluorescence in situ hybridization using 5S, 18S rDNA, and U2 snRNA genes as probes in eight Triportheus species. This work represents the first one analyzing the chromosomal distribution of U2 snRNA genes in genomes of Triportheidae. The variability in number of rDNA clusters, and the divergent syntenies for these three multigene families, put in evidence their evolutionary dynamism, revealing a much more complex organization of these genes than previously supposed for closely related species. Our study also provides additional data on the accumulation of repetitive sequences in the sex-specific chromosome. Besides, the chromosomal organization of U2 snDNAs among fish species is also reviewed.Este estudio fue apoyado por las agencias brasileñas CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico—proc. no 306896/2014-1), FAPESP (Fundacao de Amparo a` Pesquisa do Estado de Sa˜o Paulo—Proc. no 2014/ 22532 -7), y CAPES (Coordenac¸a˜o de Aperfeic¸oamento de Pessoal de Nı ´vel Superior—proc. no BEX 11744/13-8)

Analysis and optimization of the virtual teaching practice of Applied Physicochemistry

Se analiza la estrategia empleada para el dictado virtual de la asignatura Fisicoquímica Aplicada de la Carrera de Especialización en Esterilización para Farmacéuticos. Se describe el programa de actividades desarrollado puntualizando las Fortalezas/Debilidades y Oportunidades/Amenazas del empleo del Aula Virtual, comparando las observaciones de docentes y alumnos en varias cohortes. Se proponen acciones a implementarse con el objetivo de enriquecer el dictado de la asignatura.Universidad de Buenos AiresInstituto de Fisiología Vegeta