242 research outputs found
Evaluation of sperm genomic integrity of normozoospermic men: a prospective study.
The objective of our study was to evaluate the incidence of spermatozoa with nuclear DNA strand breaks in patients with normal routine sperm parameters (26 subjects). Sperm DNA fragmentation was measured using TUNEL test assessed in flow cytometer. Variable percentages of sperm with damaged DNA (9.42 +/- 7.68%; range: 2-36) were found. Two categories of patients were distinguished: (1) patients (8 out of 26 subjects) with 4% of TUNEL-positive sperm. A significantly lower percentage of normal sperm forms was found in patients with > 4% of TUNEL-positive sperm than in patients with 4% of TUNEL-positive cells (11 out of 18 subjects). Our results suggest that in some patients with normal routine sperm parameters, DNA fragmentation may be associated with poor sperm morphology. The diminished sperm genomic integrity may result from molecular disturbances in nuclear remodeling process during spermiogenesis. TUNEL assay is a screening tool that may help to discriminate between fertile and infertile men and may help to predict successful in vitro fertilization
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
The hourglass and the early conservation models--co-existing patterns of developmental constraints in vertebrates.
Developmental constraints have been postulated to limit the space of feasible phenotypes and thus shape animal evolution. These constraints have been suggested to be the strongest during either early or mid-embryogenesis, which corresponds to the early conservation model or the hourglass model, respectively. Conflicting results have been reported, but in recent studies of animal transcriptomes the hourglass model has been favored. Studies usually report descriptive statistics calculated for all genes over all developmental time points. This introduces dependencies between the sets of compared genes and may lead to biased results. Here we overcome this problem using an alternative modular analysis. We used the Iterative Signature Algorithm to identify distinct modules of genes co-expressed specifically in consecutive stages of zebrafish development. We then performed a detailed comparison of several gene properties between modules, allowing for a less biased and more powerful analysis. Notably, our analysis corroborated the hourglass pattern at the regulatory level, with sequences of regulatory regions being most conserved for genes expressed in mid-development but not at the level of gene sequence, age, or expression, in contrast to some previous studies. The early conservation model was supported with gene duplication and birth that were the most rare for genes expressed in early development. Finally, for all gene properties, we observed the least conservation for genes expressed in late development or adult, consistent with both models. Overall, with the modular approach, we showed that different levels of molecular evolution follow different patterns of developmental constraints. Thus both models are valid, but with respect to different genomic features
Metformin and Its Sulfenamide Prodrugs Inhibit Human Cholinesterase Activity
The results of epidemiological and pathophysiological studies suggest that type 2 diabetes mellitus (T2DM) may predispose to Alzheimer’s disease (AD). The two conditions present similar glucose levels, insulin resistance, and biochemical etiologies such as inflammation and oxidative stress. The diabetic state also contributes to increased acetylcholinesterase (AChE) activity, which is one of the factors leading to neurodegeneration in AD. The aim of this study was to assess in vitro the effects of metformin, phenformin, and metformin sulfenamide prodrugs on the activity of human AChE and butyrylcholinesterase (BuChE) and establish the type of inhibition. Metformin inhibited 50% of the AChE activity at micromolar concentrations (2.35 μmol/mL, mixed type of inhibition) and seemed to be selective towards AChE since it presented low anti-BuChE activity. The tested metformin prodrugs inhibited cholinesterases (ChE) at nanomolar range and thus were more active than metformin or phenformin. The cyclohexyl sulfenamide prodrug demonstrated the highest activity towards both AChE (IC50 = 890 nmol/mL, noncompetitive inhibition) and BuChE (IC50 = 28 nmol/mL, mixed type inhibition), while the octyl sulfenamide prodrug did not present anti-AChE activity, but exhibited mixed inhibition towards BuChE (IC50 = 184 nmol/mL). Therefore, these two bulkier prodrugs were concluded to be the most selective compounds for BuChE over AChE. In conclusion, it was demonstrated that biguanides present a novel class of inhibitors for AChE and BuChE and encourages further studies of these compounds for developing both selective and nonselective inhibitors of ChEs in the future
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
Psychiatric and neurocognitive consequences of endogenous hypercortisolism
Psychiatric and neurocognitive symptoms due to hypercortisolism were already described by Harvey Cushing in his original paper on patients with Cushing's syndrome (CS). Nowadays, it is well known that psychiatric and cognitive complaints are two of the most common, and most distressing, symptoms in patients with CS. Psychiatric symptoms are indeed a major clinical manifestation of CS. The most commonly observed psychiatric conditions are depression and anxiety, whilst mania and psychosis are less common. Several domains of cognitive function are impaired at diagnosis, including episodic and working memory, executive function and attention. Following treatment, one-fourth of the patients still experience depressed mood, and the cognitive impairments are only partially restored. Consequently, quality of life in patients with CS is severely and persistently affected. Neuroimaging studies have also illustrated the deleterious effects of hypercortisolism on the brain by demonstrating reduced grey matter volumes and cortical thickness, altered resting-state functional responses and during cognitive tasks, as well as widespread reduced white matter integrity, especially in structures important for cognitive function and emotional processing, both before and after successful abrogation of hypercortisolism. In this paper, we summarize the current knowledge on the psychiatric and neurocognitive consequences of hypercortisolism in patients with CS, both before, and after successful treatment. In addition, we review the structural and functional brain abnormalities associated with hypercortisolism and discuss the influence of these factors on quality of life
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
Aplinkos įtaka duoninių (Triticum aestivum L.) ir kietųjų (Triticum durum Desf.) kviečių albuminų kiekiui
Albumins or water soluble proteins (wsp) in wheat are important as nutrients containing high content of essential amino acids such as lysine, tryptophan, methionine, and also asparagine, glutamine, arginine, and proline in comparison to storage proteins-glutenins and gliadins. Fifteen bread wheat (Triticum aestivum L.) and 15 durum wheat (Triticum durum Desf.) genotypes were evaluated across six different environments for two years to determine the content of albumins in grains. The purpose of this research was to determine the variability of the albumins content of the tested bread wheat and durum wheat genotypes, effects of environment, genotype and their interaction (GEI) on the trait of interest, heritability in a broad sense, stability, and also to interpret GEI by climatic factors modelling. The statistical procedure included analysis of variance, sites regression and factorial regression. The mean content of albumins was 20.23 g kg-1 in bread wheat and 23.12 g kg-1 in durum wheat. Environment followed by GEI was the most important in determining albumins content. The heritability in a broad sense was low, i.e. 31.3% for bread wheat and only 2.4% for durum wheat. GEI for the albumins content was explained with the efficacy of 94.7% and 94.2% of sum of squares, for bread wheat and durum wheat, respectively, by the following models: mean temperature in May, winter moisture reserves, minimum temperature in April and March for bread wheat; and precipitation sum in April, sunshine hours sum in March, maximum temperature in May, and winter moisture reserves for durum wheat. The simultaneous selection for high albumins content and good stability proved to be possible for bread wheat genotypes, but less for durum wheat genotypes due to unsatisfactory stability
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
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