dUTPase activity is critical to maintain genetic stability in Saccharomyces cerevisiae

We identified a viable allele (dut1-1) of the DUT1 gene that encodes the dUTPase activity in Saccharomyces cerevisiae. The Dut1-1 protein possesses a single amino acid substitution (Gly82Ser) in a conserved motif nearby the active site and exhibits a greatly reduced dUTPase activity. The dut1-1 single mutant exhibits growth delay and cell cycle abnormalities and shows a strong spontaneous mutator phenotype. All phenotypes of the dut1-1 mutant are suppressed by the simultaneous inactivation of the uracil DNA N-glycosylase, Ung1. However, the ung1 dut1-1 double mutant accumulates uracil in its genomic DNA. The viability of the dut1-1 mutant is greatly impaired by the simultaneous inactivation of AP endonucleases. These data strongly suggest that the phenotypes of the dut1-1 mutant result from the incorporation of dUMPs into DNA subsequently converted into AP sites. The analysis of the dut1-1 strain mutation spectrum showed that cytosines are preferentially incorporated in front of AP sites in a Rev3-dependent manner during translesion synthesis. These results point to a critical role of the Dut1 protein in the maintenance of the genetic stability. Therefore, the normal cellular metabolism, and not only its byproducts, is an important source of endogenous DNA damage and genetic instability in eukaryotic cells

Diffuse laser illumination for Maxwellian view Doppler holography of the retina

We describe the advantages of diffuse illumination in laser holography for ophthalmology. The presence of a diffusing element introduces an angular diversity of the optical radiation and reduces its spatial coherence, which spreads out the energy distribution of the illumination beam in the focal plane of the eyepiece. The field of view of digitally computed retinal images can easily be increased as the eyepiece can be moved closer to the cornea to obtain a Maxwellian view of the retina without compromising ocular safety. Compliance with American and European safety standards for ophthalmic devices is more easily obtained by preventing the presence of a laser hot spot observed in front of the cornea in the absence of a scattering element. Diffuse laser illumination does not introduce any adverse effects on digitally computed laser Doppler images.Comment: 9 page

LES DECHETS D'ACTIVITES DE SOINS SOLIDES A RISQUES

RENNES1-BU Santé (352382103) / SudocSudocFranceF

The post-replication repair RAD18 and RAD6 genes are involved in the prevention of spontaneous mutations caused by 7,8-dihydro-8-oxoguanine in Saccharomyces cerevisiae

7,8-Dihydro-8-oxoguanine (8-oxoG) is an abundant and mutagenic lesion produced in DNA exposed to free radicals and reactive oxygen species. In Saccharomyces cerevisiae, the OGG1 gene encodes the 8-oxoG DNA N-glycosylase/AP lyase (Ogg1), which is the functional homologue of the bacterial Fpg. Ogg1-deficient strains are spontaneous mutators that accumulate GC to TA transversions due to unrepaired 8-oxoG in DNA. In yeast, DNA mismatch repair (MMR) and translesion synthesis (TLS) by DNA polymerase η also play a role in the prevention of the mutagenic effect of 8-oxoG. In the present study, we show the RAD18 and RAD6 genes that are required to initiate post-replication repair (PRR) are also involved in the prevention of mutations by 8-oxoG. Consistently, a synergistic increase in spontaneous Can(R) and Lys(+) mutation rates is observed in the absence of Rad6 or Rad18 proteins in ogg1 mutant strains. Spectra of Can(R) mutations in ogg1 rad18 and ogg1 rad6 double mutants show a strong bias in the favor of GC to TA transversions, which are 137- and 189-fold higher than in the wild-type, respectively. The results also show that Polη (RAD30 gene product) plays a critical role on the prevention of mutations at 8-oxoG, whereas Polζ (REV3 gene product) does not. Our current model suggests that the Rad6–Rad18 complex targets Polη at DNA gaps that result from the MMR-mediated excision of adenine mispaired with 8-oxoG, allowing error-free dCMP incorporation opposite to this lesion

PCNA monoubiquitylation and DNA polymerase h ubiquitin-binding domain are required to prevent 8-oxoguanine-induced mutagenesis in Saccharomycese cerevisiae

International audienc

Prognostic value of the 12-lead surface electrocardiogram in sarcomeric hypertrophic cardiomyopathy data from the REMY French register

International audienceTo identify independent electrocardiogram (ECG) predictors of long-term clinical outcome based on standardized analysis of the surface ECG in a large multicentre cohort of patients with sarcomeric hypertrophic cardiomyopathy (HCM)

Effect of bag-mask ventilation vs endotracheal intubation during cardiopulmonary resuscitation on neurological outcome after out-of-hospital cardiorespiratory arrest a randomized clinical trial

IMPORTANCE Bag-mask ventilation (BMV) is a less complex technique than endotracheal intubation (ETI) for airway management during the advanced cardiac life support phase of cardiopulmonary resuscitation of patients with out-of-hospital cardiorespiratory arrest. It has been reported as superior in terms of survival. OBJECTIVES To assess noninferiority of BMV vs ETI for advanced airway management with regard to survival with favorable neurological function at day 28. DESIGN, SETTINGS, AND PARTICIPANTS Multicenter randomized clinical trial comparingBMVwith ETI in2043patientswithout-of-hospital cardiorespiratoryarrest inFranceandBelgium.Enrollment occurred from March 9, 2015, to January 2, 2017, and follow-up ended January 26, 2017. INTERVENTION Participants were randomized to initial airway management with BMV (n = 1020) or ETI (n = 1023). MAIN OUTCOMES AND MEASURES The primary outcomewas favorable neurological outcome at 28 days defined as cerebral performance category 1 or 2. A noninferiority margin of 1% was chosen. Secondary end points included rate of survival to hospital admission, rate of survival at day 28, rate of return of spontaneous circulation, and ETI and BMV difficulty or failure. RESULTS Among 2043 patients who were randomized (mean age, 64.7 years; 665 women [32%]), 2040 (99.8%) completed the trial. In the intention-To-Treat population, favorable functional survival at day 28 was 44 of 1018 patients (4.3%) in the BMV group and 43 of 1022 patients (4.2%) in the ETI group (difference, 0.11% [1-sided 97.5%CI, 1.64%to infinity]; P for noninferiority = .11). Survival to hospital admission (294/1018 [28.9%] in the BMV group vs 333/1022 [32.6%] in the ETI group; difference, 3.7%[95%CI, 7.7%to 0.3%]) and global survival at day 28 (55/1018 [5.4%] in the BMV group vs 54/1022 [5.3%] in the ETI group; difference, 0.1%[95%CI, 1.8%to 2.1%]) were not significantly different. Complications included difficult airway management (186/1027 [18.1%] in the BMV group vs 134/996 [13.4%] in the ETI group; difference, 4.7%[95%CI, 1.5%to 7.9%]; P = .004), failure (69/1028 [6.7%] in the BMV group vs 21/996 [2.1%] in the ETI group; difference, 4.6%[95%CI, 2.8% to 6.4%]; P < .001), and regurgitation of gastric content (156/1027 [15.2%] in the BMV group vs 75/999 [7.5%] in the ETI group; difference, 7.7%[95%CI, 4.9% to 10.4%]; P < .001). CONCLUSIONS AND RELEVANCE Among patients with out-of-hospital cardiorespiratory arrest, the use of BMV compared with ETI failed to demonstrate noninferiority or inferiority for survival with favorable 28-day neurological function, an inconclusive result. A determination of equivalence or superiority between these techniques requires further research.SCOPUS: ar.jinfo:eu-repo/semantics/publishe