Micro-vibration results in vitro-derived bovine blastocysts with greater cryotolerance, epigenetic abnormalities, and a massive transcriptional change.

Much effort has been employed to improve the quality of embryos obtained by in vitro production (IVP) given the relevance of this technology to current livestock systems. In this context, dynamic IVP systems have proved beneficial to the embryo once they mimic fluid flows and mechanical forces resulting from the movement of ciliated cells and muscle contraction in the reproductive tract. In the present study, we sought to confirm these initial findings as well as assess potential molecular consequences to the embryo by applying micro-vibration (45 Hz for 5 s once per 60 min) during both oocyte maturation and embryo culture in cattle. As a result, micro-vibration led to lower incidence of apoptosis in blastocysts following vitrification-thawing. Further analyses revealed epigenetic and transcriptional changes in blastocysts derived from the micro-vibration treatment, with a total of 502 differentially expressed genes. Enrichment analyses linked differentially expressed genes to 'Oxidative phosphorylation', 'Cytokine-cytokine receptor interaction', and 'Signaling pathways regulating pluripotency of stem cells'. Yet, a meta-analysis indicated that the transcriptional changes induced by micro-vibration were not toward that of in vivo-derived embryos. In conclusion, micro-vibration increases the cryoresistance of bovine embryos, but caution should be taken given the unclear consequences of epigenetic and transcriptional abnormalities induced by the treatment.

Diluent Containing Dimethylformamide Added With Sucrose Improves In Vitro Quality After Freezing/Thawing Stallion Sperm.

The aim of this study was to investigate the effects of sucrose on post-thawed equine semen quality. Semen samples (n = 24) were collected from six stallions. They were diluted (200 × 106 sperm/mL) in a freezing medium based on skimmed milk, egg yolk, dimethylformamide, and supplemented with sucrose at concentrations of 0 (Control), 25, 50, and 100 mM and in a commercial extender (BotuCrio). Subsequently, they were filled in straws (0.5 mL) and subjected to freezing and storage (-196°C). Immediately after thawing (37°C, 30 seconds), semen samples were evaluated for kinetics (CASA), plasma and acrosomal membrane integrity, and mitochondrial membrane potential (flow cytometry). The addition of 50 and 100mM sucrose to the freezing extender increased (P < .05) the parameters of TM, PM, VCL, VSL, and VAP, compared to the control group. The WOB parameter of the group supplemented with 100 mM sucrose was higher (P < .05) than the control group. Higher values ​​(P < .05) of ALH and BCF were observed in groups treated with sucrose (25, 50, and 100 mM), compared to BotuCrio. The semen frozen in the presence of 100 mM sucrose presented higher percentages (P < .05) of sperm with intact plasma and acrosomal membranes, and high mitochondrial membrane potential in relation to the other groups. It is concluded that the addition of sucrose to equine semen freezing extender increase motility (50 and 100 mM), plasma and acrosomal membrane integrity preserve, and high sperm mitochondrial membrane potential (100 mM) after thawing.

Influence of silane and solvated bonding agents on the bond strength to glass-fibre posts.

The combined use of silane and solvated bonding agents on the bond strength to glass-fibre posts was investigated. A model Bis-GMA/HEMA adhesive was formulated with no solvent, 30% of ethanol or 80% of acetone. The surfaces of rectangular-shaped posts were silanated or not and one of the agents was applied, except for the control group. Cylinders of resin cement (RelyX ARC, 3M ESPE, Saint Paul, MN, USA) were built-up on the surfaces (n = 20) and submitted to shear testing. All groups showed higher bond strengths when the surfaces were silanated. When no silanization was carried out, the use of bonding agents, either solvated or non-solvated, increased the bond strengths. All groups treated with both silane and bonding agent showed higher bond strengths than the group that was only silanated. Control and ethanol-based adhesives were similar, whereas the acetone-based agent yielded higher bond strengths. Adhesive failures were predominant. Combination of silane and adhesive enhanced the bond to fibre posts.

Polymerization efficiency through translucent and opaque fiber posts and bonding to root dentin.

PURPOSE: To investigate the polymerization efficiency through translucent and opaque glass fiber posts and the bond strength of a self-adhesive resin to root dentin. METHODS: Translucent and opaque silanated conical posts, identical in length, diameter and shape (n=8), were cemented to incisor bovine roots using RelyX Unicem Clicker. Photoactivation was performed only through the posts. The roots were transversally sectioned (cervical, middle and apical thirds) and the push-out test was carried out. Data were analyzed using two-way ANOVA and Fisher's LSD method (5%). Failure modes were classified under magnification. An elastomer mold of a bovine incisor root was filled with flowable composite and the posts inserted into the mold. After photoactivation through the post and removal of unpolymerized material, the polymerization efficiency was estimated by percentage of mass gain (n=5). Data were analyzed using t-test (5%). RESULTS: The bond strength of the translucent post was higher than the opaque post for all root thirds. For both posts the bond strength at the cervical third was higher than at the middle and apical thirds. A predominance of adhesive failures was detected for all conditions. Mixed failures were more frequently observed for the opaque post. Almost all the composite polymerized and bonded to the extension of the translucent post, whereas polymerization of the composite was restricted to the cervical area of the opaque post. CONCLUSIONS: The use of translucent post may positively influence the polymerization efficiency and bond strength of resin cement to intraradicular dentin.

Bromophenol concentrations in fish from Salvador, BA, Brazil.

The main objective of this work is to evaluate the occurrence of bromophenols (2bromophenol, 4bromophenol, 2,4dibromophenol, 2,6dibromophenol and 2,4,6tribromophenol), in the flesh and guts in two species of the LutjanidaeFamily: Lutjanus synagris and Ocyurus chrysurus. The bromophenols were extracted by steam distillation with pentaneether (7:3 v/v), identified by reverse phase High Performance Liquid Chromatography (HPLCUV), and quantified bythe externalstandard method. Total bromophenol concentrations were similar in the muscle of both species, rangingfrom 36 ng g(1) to 349 ng g(1). The total bromophenol concentrations in stomach (ranging from 12 ng g(1) to 586 ng g(1))were slightly higher than in muscle. The presence of bromophenol in the muscles of the species under study may occuras a result of their diet. The results of this work are therefore expected to contribute toward a better understanding ofthe path of bromophenol absorption from the fish's stomach to the rest of its body.

Bromophenol concentrations in fish from Salvador, BA, Brazil

The main objective of this work is to evaluate the occurrence of bromophenols (2bromophenol, 4bromophenol, 2,4dibromophenol, 2,6dibromophenol and 2,4,6tribromophenol), in the flesh and guts in two species of the LutjanidaeFamily: Lutjanus synagris and Ocyurus chrysurus. The bromophenols were extracted by steam distillation with pentaneether (7:3 v/v), identified by reverse phase High Performance Liquid Chromatography (HPLCUV), and quantified bythe externalstandard method. Total bromophenol concentrations were similar in the muscle of both species, rangingfrom 36 ng g¹ to 349 ng g¹. The total bromophenol concentrations in stomach (ranging from 12 ng g¹ to 586 ng g¹)were slightly higher than in muscle. The presence of bromophenol in the muscles of the species under study may occuras a result of their diet. The results of this work are therefore expected to contribute toward a better understanding ofthe path of bromophenol absorption from the fish's stomach to the rest of its body.

O principal objetivo do presente trabalho foi o estudo de bromofenóis (2bromofenol, 4bromofenol, 2,4dibromofenol,2,6dibromofenol and 2,4,6tribromofenol), no músculo e estômago de duas espécies de peixes da Familia Lutjanidae: Lutjanus synagris e Ocyurus chrysurus. Os bromofenóis foramextraídos através de destilação por arraste a vapor com pentanoéter (7:3 v/v), analisados por Cromatografia Líquida de AltaEficiência e quantificados por padronização externa. As concentrações totais de bromofenóis no músculo de ambas as espécies foram similares e estiveram na faixa de 36 ng g¹ a349 ng g¹. As concentrações totais de bromofenóis no estômago (na faixa de 12 ng g¹ a 586 ng g¹) foram mais altas queno músculo. A presença de bromofenóis no músculo das espécies estudadas pode ter origem na dieta. Os resultados destetrabalho contribuirão para o melhor entendimento das rotas deabsorção de bromofenóis nos peixes.

Determination of simple bromophenols in marine fishes by reverse-phase high performance liquid chromatography (RP-HPLC).

Brominated phenols 2- and 4-bromophenol (2-BP and 4-BP); 2,4- and 2,6-dibromophenol (2,4-DBP and 2,6-DBP) and 2,4,6-tribromophenol (2,4,6-TBP) have been identified as key flavor compounds found in seafoods. Depending on their concentrations, they were responsible for marine or ocean flavor (shrimp/crab/fish/sea salt-like) or for phenolic/iodine/iodoform-like off-flavor. In this work a new analytical methodology was developed to determine, simultaneously, such bromophenols in fish meats, based on reversed-phased high-performance liquid chromatographic separation (RP-HPLC). The separation of bromophenols was made onto a Lichrospher 100 RP-18 column using water:acetonitrile gradient at a flow rate of 1.0mLmin(-1), using absorbance detection at 286nm, were the 2-BP, 4-BP, 2,4- and 2,6-DBP show significant absorbtivity values and at 297nm for 2,4,6-TBP. They were separated in 20min with a good chromatographic resolution (Rs) for the isomeric compounds: 2- and 4-BP, Rs=1.23; 2,4- and 2,6-DBP, Rs=1.63. The calibration curves were linear in the bromophenols concentration range of 200.0-1000ngmL(-1). Under optimized conditions, the detection limit of the HPLC method was 127ngmL(-1) for 2-BP; 179ngmL(-1) for 4-BP; 89.0ngmL(-1) for 2,4-DBP; 269ngmL(-1) for 2,6-DBP and 232ngmL(-1) for 2,4,6-TBP. This method has been applied in determination of bromophenols, isolated by combined steam distillation-solvent extraction with 2mL of pentane/diethyl ether (6:4), from Brazilian fishes samples, collected on the Atlantic coast of Bahia (13 degrees 01'S and 38 degrees 31'W), Brazil. The concentration range determined were 0.20ngg(-1) (2-BP) to 299ngg(-1) (2,4,6-TBP). The method proposed here is rapid and suitable for simultaneous quantification of simple bromophenols in fish meat. As long as we know, it is the first analytical methodology, using RP-HPLC/UV, which was developed to determine simple bromophenols in fish meat.