Lyonsmatthews8979

What is the relationship between sperm DNA fragmentation and oxidative stress (OS) with increasing male age?

Sperm DNA fragmentation increases with age and is likely related to both defective spermatogenesis and increasing OS levels.

Sperm quality declines with age. The presence of DNA damage in a high fraction of spermatozoa from a raw semen sample is associated with lower male fertility in natural conception and intrauterine insemination.

A retrospective cohort study of 16 945 semen samples analysed at a single reference laboratory between January 2010 and December 2018.

All males were undergoing an infertility evaluation. The cohort was divided into seven age categories <30, 30-34, 35-39, 40-44, 45-49, 50 to <54 and ≥55 years. The mean age was 37.6 years (SD 6.8). Sperm DNA fragmentation index (DFI) and high DNA stainability (HDS) were calculated using flow cytometry. OS levels were measured using the oxidative stress adducts (OSA) test, by spectrophotometry. ANOVA with weighted polynomial er studies are needed to evaluate the effect of advancing paternal age on the male genome and, ultimately, on the health of the offspring.

No funding was obtained for this study. V.D. is an employee of Reprosource/Quest Diagnostics. D.S. reports he was a Scientific Advisor to Cooper Surgical.

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N/A.Kinetochores are large multi-subunit complexes that attach centromeric chromatin to microtubules of the mitotic spindle, enabling sister chromatid segregation in mitosis. The inner kinetochore constitutive centromere associated network (CCAN) complex assembles onto the centromere-specific Cenp-A nucleosome (Cenp-ANuc), thereby coupling the centromere to the microtubule-binding outer kinetochore. CCAN is a conserved 14-16 subunit complex composed of discrete modules. Here, we determined the crystal structure of the Saccharomyces cerevisiae Cenp-HIKHead-TW sub-module, revealing how Cenp-HIK and Cenp-TW interact at the conserved Cenp-HIKHead-Cenp-TW interface. A major interface is formed by the C-terminal anti-parallel α-helices of the histone fold extension (HFE) of the Cenp-T histone fold domain (HFD) combining with α-helix H3 of Cenp-K to create a compact three α-helical bundle. We fitted the Cenp-HIKHead-TW sub-module to the previously determined cryo-EM map of the S. cerevisiae CCAN-Cenp-ANuc complex. This showed that the HEAT repeat domain of Cenp-IHead and C-terminal HFD of Cenp-T of the Cenp-HIKHead-TW sub-module interact with the nucleosome DNA gyre at a site close to the Cenp-ANuc dyad axis. Our structure provides a framework for understanding how Cenp-T links centromeric Cenp-ANuc to the outer kinetochore through its HFD and N-terminal Ndc80-binding motif, respectively.The triple-negative breast cancer (TNBC), a subtype of breast cancer which lacks of targeted therapies, exhibits a poor prognosis. It was shown recently that the PIM1 oncogene is highly related to the proliferation of TNBC cells. A quadruplex-duplex hybrid (QDH) forming sequence was recently found to exist near the transcription start site of PIM1. This structure could be an attractive target for regulation of the PIM1 gene expression and thus the treatment of TNBC. Here, we present the solution structures of two QDHs that could coexist in the human PIM1 gene. Form 1 is a three-G-tetrad-layered (3+1) G-quadruplex containing a propeller loop, a lateral loop and a stem-loop made up of three G•C Watson-Crick base pairs. On the other hand, Form 2 is an anti-parallel G-quadruplex comprising two G-tetrads and a G•C•G•C tetrad; the structure has three lateral loops with the middle stem-loop made up of two Watson-Crick G•C base pairs. These structures provide valuable information for the design of G-quadruplex-specific ligands for PIM1 transcription regulation.Smoking may modify the lung response to silica exposure including cancer and silicosis. Nevertheless, the precise role of exposure to tobacco smoke (TS) on the lung response to crystalline silica (CS) exposure and the underlying mechanisms need further clarification. The objectives of the present study were to determine the role of TS on lung response to CS exposure and the underlying mechanism(s). Male Fischer 344 rats were exposed by inhalation to air, CS (15 mg/m3, 6 h/day, 5 days), TS (80 mg/m3, 3 h/day, twice weekly, 6 months), or CS (15 mg/m3, 6 h/day, 5 days) followed by TS (80 mg/m3, 3 h/day, twice weekly, 6 months). The rats were euthanized 6 months and 3 weeks following initiation of the first exposure and the lung response was assessed. Silica exposure resulted in significant lung toxicity as evidenced by lung histological changes, enhanced neutrophil infiltration, increased lactate dehydrogenase levels, enhanced oxidant production, and increased cytokine levels. The TS exposure alone had only a minimal effect on these toxicity parameters. However, the combined exposure to TS and CS exacerbated the lung response, compared with TS or CS exposure alone. Tamoxifen mouse Global gene expression changes in the lungs correlated with the lung toxicity severity. Bioinformatic analysis of the gene expression data demonstrated significant enrichment in functions, pathways, and networks relevant to the response to CS exposure which correlated with the lung toxicity detected. Collectively our data demonstrated an exacerbation of CS-induced lung toxicity by TS exposure and the molecular mechanisms underlying the exacerbated toxicity.

COVID-19 has rapidly evolved to become a global pandemic due largely to the transmission of its causative virus through asymptomatic carriers. Detection of SARS-CoV-2 in asymptomatic people is an urgent priority for the prevention and containment of disease outbreaks in communities. However, few data are available in asymptomatic persons regarding the accuracy of PCR testing. Additionally, although self-collected saliva has significant logistical advantages in mass screening, its utility as an alternative specimen in asymptomatic persons is yet to be determined.

We conducted a mass-screening study to compare the utility of nucleic acid amplification, such as reverse transcriptase polymerase chain reaction (RT-PCR) testing, using nasopharyngeal swabs (NPS) and saliva samples from each individual in two cohorts of asymptomatic persons the contact tracing cohort and the airport quarantine cohort.

In this mass-screening study including 1,924 individuals, the sensitivity of nucleic acid amplification testing with nasopharyngeal and saliva specimens were 86% (90%CI77-93%) and 92% (90%CI83-97%), respectively, with specificities greater than 99.9%. The true concordance probability between the nasopharyngeal and saliva tests was estimated at 0.998 (90%CI0.996-0.999) on the estimated airport prevalence at 0.3%. In positive individuals, viral load was highly correlated between NPS and saliva.

Both nasopharyngeal and saliva specimens had high sensitivity and specificity. Self-collected saliva is a valuable specimen to detect SARS-CoV-2 in mass screening of asymptomatic persons.

Both nasopharyngeal and saliva specimens had high sensitivity and specificity. Self-collected saliva is a valuable specimen to detect SARS-CoV-2 in mass screening of asymptomatic persons.Previous studies have confirmed that both non-reward objects (such as rectangles) and reward objects (such as banknotes) can guide the allocation of our attention; however, it is unclear whether the allocation mode of attention for reward objects is the same as for non-reward objects. This study aims to evaluate different modes of object-based attentional selection elicited by two types of objects reward objects and non-reward objects. In our analysis, we used a two-rectangle paradigm in which two objects were presented visually. In a series of four experiments, we found a constant object-based effect with non-reward objects, such as rectangles and umbrellas, as stimuli in all of the stimulus onset asynchrony (SOA) conditions (Experiments 1 and 4), but the object-based effect disappeared only at longer SOA with reward objects such as monetary and food objects as stimuli (Experiments 2 and 3). Moreover, we found that monetary and food objects induced similar object-based effects. These results suggest that the temporal dynamics of object-based attentional allocation are different with respect to reward and non-reward objects, and different types of reward objects can guide attentional allocation in a similar way.Saccadic eye movements are typically preceded by selective shifts of visual attention. Recent evidence, however, suggests that oculomotor selection can occur in the absence of attentional selection when saccades erroneously land in between nearby competing objects (saccade averaging). This study combined a saccade task with a visual discrimination task to investigate saccade target selection during episodes of competition between a saccade target and a nearby distractor. We manipulated the spatial predictability of target and distractor locations and asked participants to execute saccades upon variably delayed go-signals. This allowed us to systematically investigate the capacity to exert top-down eye movement control (as reflected in saccade endpoints) based on the spatiotemporal dynamics of visual attention during movement preparation (measured as visual sensitivity). Our data demonstrate that the predictability of target and distractor locations, despite not affecting the deployment of visual attention prior to movement preparation, largely improved the accuracy of short-latency saccades. Under spatial uncertainty, a short go-signal delay likewise enhanced saccade accuracy substantially, which was associated with a more selective deployment of attentional resources to the saccade target. Moreover, we observed a systematic relationship between the deployment of visual attention and saccade accuracy, with visual discrimination performance being significantly enhanced at the saccade target relative to the distractor only before the execution of saccades accurately landing at the saccade target. Our results provide novel insights linking top-down eye movement control to the operation of selective visual attention during movement preparation.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel member of the coronavirus family that caused the global coronavirus 2019 (COVID-19) pandemic. The prevalence remains largely unknown because of early testing supply shortages. Although it cannot currently be used to determine level of immunity, antibody testing can contribute to epidemiological studies, identify convalescent plasma donors, or satisfy curiosity about previous exposure to the virus.

407 samples collected from hospitalized inpatients with and without a confirmed SARS-CoV-2 infection, 170 remnant clinical specimens collected and frozen prior to the COVID-19 outbreak, and paired serum and plasma samples from 23 convalescent plasma donors were used to determine performance characteristics of the Abbott SARS-CoV-2 IgG and Roche Elecsys Anti-SARS-CoV-2 assays. The sensitivity, specificity, imprecision, interferences, and sample stability were determined. These assays were then used to characterize the antibody response in serial samples from 20 SARS-CoV-2 positive inpatients.