Flow cytometry application in the assessment of sperm DNA integrity of men with asthenozoospermia.

Sperm genomic integrity and ultrastructural features of ejaculated spermatozoa contributing to the assessment of gamete fertility potential in patients with asthenozoospermia are discussed. The proportion of TUNEL-positive cells was significantly higher in the semen of patients with low sperm motility (n=40; p4% of TUNEL-positive sperm cells. Low sperm motility seems to be accompanied by serious defects of gamete chromatin expressed as diminished sperm genomic integrity and abnormal DNA condensation and by defects of sperm midpiece. These abnormalities may reflect developmental failure during the spermatogenic remodeling process. The DNA fragmentation test may be considered as an additional assay for the evaluation of spermatozoa beside standard analysis and taken together with electron microscopy may help to determine the actual number of "healthy" spermatozoa thereby playing an important role during diagnosis and treatment of male infertility

MicroRNA expression profiles in liver and colon of sexually immature gilts after exposure to Fusarium mycotoxins

To improve our knowledge of the role of microRNAs (miRs) in responses of the porcine digestive system to two Fusarium mycotoxins, zearalenone (ZEN) and deoxynivalenol (DON), we examined the expression of 7 miRs (miR-9, miR-15a, miR-21, miR-34a, miR-122, miR-125b, and miR-192), previously found to be deregulated in diseased liver and colon cells. In this study, immature gilts were exposed to NOEL doses of ZEN (40 μg/kg/d), DON (12 μg/kg/d), ZEN+DON (40+12 μg/kg/d), and placebo (negative control group) for 7, 14, 21, 28, 35, and 42 days. Before the treatment, expression levels of the selected miRs were measured in the liver, the duodenum, the jejunum, and the ascending and the descending colon of the gilts. Hierarchical clustering of the tissues by their miR expression profiles was consistent with what would be expected based on the anatomical locations and the physiological functions of the organs, suggesting that functions of the miRs are related to the specificities of the tissues in which they are expressed. A subset of 2 pairs of miRs (miR-21+miR-192 and miR-15a+miR-34a), which were assigned to two distinct clusters based on their tissue abundance, was then evaluated in the liver and the ascending and the descending colon during the treatment. The most meaningful results were obtained from the ascending colon, where a significant effect of the treatment was observed, suggesting that during the exposure to mycotoxins, the pathways involved in cell proliferation and survival were disordered. Changes in miR expression in the liver and the descending colon of the treated gilts were smaller, and were associated more with treatment duration than the exposure to ZEN, DON, or ZEN+DON. Further research should focus on identification of genes whose expression is regulated by these aberrantly expressed miRs. This should facilitate understanding of the miRNA-regulated biological effects of mycotoxins

Structural and Dynamic Regulation of TFIID-Mediated Transcription Initiation Complex Assembly by the Tumor Suppressor P53 Protein

Data aproximada de realització del reportatg

Tryptophan metabolism and bacterial commensals prevent fungal dysbiosis in Arabidopsis roots

In nature, roots of healthy plants are colonized by multikingdom microbial communities that include bacteria, fungi, and oomycetes. A key question is how plants control the assembly of these diverse microbes in roots to maintain host–microbe homeostasis and health. Using microbiota reconstitution experiments with a set of immunocompromised Arabidopsis thaliana mutants and a multikingdom synthetic microbial community (SynCom) representative of the natural A. thaliana root microbiota, we observed that microbiota-mediated plant growth promotion was abolished in most of the tested immunocompromised mutants. Notably, more than 40% of between-genotype variation in these microbiota-induced growth differences was explained by fungal but not bacterial or oomycete load in roots. Extensive fungal overgrowth in roots and altered plant growth was evident at both vegetative and reproductive stages for a mutant impaired in the production of tryptophan-derived, specialized metabolites (cyp79b2/b3). Microbiota manipulation experiments with single- and multikingdom microbial SynComs further demonstrated that 1) the presence of fungi in the multikingdom SynCom was the direct cause of the dysbiotic phenotype in the cyp79b2/b3 mutant and 2) bacterial commensals and host tryptophan metabolism are both necessary to control fungal load, thereby promoting A. thaliana growth and survival. Our results indicate that protective activities of bacterial root commensals are as critical as the host tryptophan metabolic pathway in preventing fungal dysbiosis in the A. thaliana root endosphere

Gene expression evolution in pattern-triggered immunity within Arabidopsis thaliana and across Brassicaceae species

Plants recognize surrounding microbes by sensing microbe-associated molecular patterns (MAMPs) to activate pattern-triggered immunity (PTI). Despite their significance for microbial control, the evolution of PTI responses remains largely uncharacterized. Here, by employing comparative transcriptomics of six Arabidopsis thaliana accessions and three additional Brassicaceae species to investigate PTI responses, we identified a set of genes that commonly respond to the MAMP flg22 and genes that exhibit species-specific expression signatures. Variation in flg22-triggered transcriptome responses across Brassicaceae species was incongruent with their phylogeny, while expression changes were strongly conserved within A. thaliana. We found the enrichment of WRKY transcription factor binding sites in the 5′-regulatory regions of conserved and species-specific responsive genes, linking the emergence of WRKY-binding sites with the evolution of gene expression patterns during PTI. Our findings advance our understanding of the evolution of the transcriptome during biotic stress

Efficacy and safety of dapagliflozin in heart failure with reduced ejection fraction according to age: insights from DAPA-HF

Background: The DAPA-HF trial (Dapagliflozin and Prevention of Adverse-Outcomes in Heart Failure) showed that dapagliflozin added to other guideline-recommended therapies reduced the risk of mortality and heart failure hospitalization and improved symptoms in patients with heart failure and reduced ejection fraction. We examined the effects of dapagliflozin according to age, given potential concerns about the efficacy and safety of therapies in the elderly. Methods: Patients in New York Heart Association functional class II or greater with a left ventricular ejection fraction ≤40% and a modest elevation of NT-proBNP (N-terminal pro-B-type natriuretic peptide) were eligible. Key exclusion criteria included systolic blood pressure <95 mm Hg and estimated glomerular filtration rate <30 mL·min−1·1.73 m−2. The primary outcome was the composite of an episode of worsening heart failure (heart failure hospitalization or urgent heart failure visit) or cardiovascular death, whichever occurred first. Results: A total of 4744 patients 22 to 94 years of age (mean age, 66.3 [SD 10.9] years) were randomized: 636 patients (13.4%) were <55 years of age, 1242 (26.2%) were 55 to 64 years of age, 1717 (36.2%) were 65 to 74 years of age, and 1149 (24.2%) were ≥75 years of age. The rate of the primary outcome (per 100 person-years, placebo arm) in each age group was 13.6 (95% CI, 10.4–17.9), 15.7 (95% CI, 13.2–18.7), 15.1 (95% CI, 13.1–17.5), and 18.0 (95% CI, 15.2–21.4) with corresponding dapagliflozin/placebo hazard ratios of 0.87 (95% CI, 0.60–1.28), 0.71 (95% CI, 0.55–0.93), 0.76 (95% CI, 0.61–0.95), and 0.68 (95% CI, 0.53–0.88; P for interaction=0.76). Consistent benefits were observed for the components of the primary outcome, all-cause mortality, and symptoms. Although adverse events and study drug discontinuation increased with age, neither was significantly more common with dapagliflozin in any age group. Conclusions: Dapagliflozin reduced the risk of death and worsening heart failure and improved symptoms across the broad spectrum of age studied in DAPA-HF. There was no significant imbalance in tolerability or safety events between dapagliflozin and placebo, even in elderly individuals

Experimental and Numerical Investigation of Micro/Mini Channel Flow-Boiling Heat Transfer with Non-Uniform Circumferential Heat Fluxes at Different Rotational Orientations

Flow-boiling of Perfluorohexane (FC-72) in horizontal micro/mini channels was investigated experimen- tally and numerically at different rotational orientations in terms of gravity. One-sided uniform channel heating was considered experimentally for rotational angles ranging from 0 °(heating from below) to 180 °(heating from above) in increments of 30 °. The micro/mini channel had a high aspect ratio of 10 (5 mm x 0.5 mm) and a hydraulic diameter of 909 μm. In-channel flow visualisations were recorded and heat transfer coefficients were determined for mass fluxes of 10, 20 and 40 kg/m 2 s at a saturation temperature of 56 °C. Suitable heat fluxes were applied to span the onset of nucleate boiling to near dry-out conditions within the channel. It was found that the rotational angle had a significant influence on the heat transfer performance due to its influence on bubble detachment. Bottom-heated cases (0 °orientation) resulted in local heat transfer coefficients that were up to 201% higher than for any other rotational orientation. Channel orientations of 60 °(slanted heating surface) and 90 °(heating from the side) generally produced the lowest local heat transfer coefficients. Insight into the influence of the grav- itational orientation on single-bubble growth within the nucleation and detachment region was obtained via two- and three-dimensional numerical simulations. Bubble behaviour after detachment and its effect on heat transfer were also investigated transiently until detachment. The numerical simulations mirrored the experimental trends and it was found that the presence of growing bubbles interrupted the velocity streamlines and the thermal boundary layer downstream of the nucleation sit

Roles of the DYRK Kinase Pom2 in Cytokinesis, Mitochondrial Morphology, and Sporulation in Fission Yeast

Pom2 is predicted to be a dual-specificity tyrosine-phosphorylation regulated kinase (DYRK) related to Pom1 in Schizosaccharomyces pombe. DYRKs share a kinase domain capable of catalyzing autophosphorylation on tyrosine and exogenous phosphorylation on serine/threonine residues. Here we show that Pom2 is functionally different from the well-characterized Pom1, although they share 55% identity in the kinase domain and the Pom2 kinase domain functionally complements that of Pom1. Pom2 localizes to mitochondria throughout the cell cycle and to the contractile ring during late stages of cytokinesis. Overexpression but not deletion of pom2 results in severe defects in cytokinesis, indicating that Pom2 might share an overlapping function with other proteins in regulating cytokinesis. Gain and loss of function analyses reveal that Pom2 is required for maintaining mitochondrial morphology independently of microtubules. Intriguingly, most meiotic pom2Δ cells form aberrant asci with meiotic and/or forespore membrane formation defects. Taken together, Pom2 is a novel DYRK kinase involved in regulating cytokinesis, mitochondrial morphology, meiosis, and sporulation in fission yeast

The chemical signatures underlying host plant discrimination by aphids

The diversity of phytophagous insects is largely attributable to speciation involving shifts between host plants. These shifts are mediated by the close interaction between insects and plant metabolites. However, there has been limited progress in understanding the chemical signatures that underlie host preferences. We use the pea aphid (Acyrthosiphon pisum) to address this problem. Host-associated races of pea aphid discriminate between plant species in race-specific ways. We combined metabolomic profiling of multiple plant species with behavioural tests on two A. pisum races, to identify metabolites that explain variation in either acceptance or discrimination. Candidate compounds were identified using tandem mass spectrometry. Our results reveal a small number of compounds that explain a large proportion of variation in the differential acceptability of plants to A. pisum races. Two of these were identified as L-phenylalanine and L-tyrosine but it may be that metabolically-related compounds directly influence insect behaviour. The compounds implicated in differential acceptability were not related to the set correlated with general acceptability of plants to aphids, regardless of host race. Small changes in response to common metabolites may underlie host shifts. This study opens new opportunities for understanding the mechanistic basis of host discrimination and host shifts in insects