Role of the C-terminus of the Catalytic Subunit of Translesion Synthesis Polymerase ζ (Zeta) in UV-induced Mutagensis

Cellular DNA is under constant attack by endogenous and exogenous DNA damaging agents that threaten genome integrity. Unrepaired DNA lesions often stall replicative DNA polymerases and are bypassed by translesion synthesis (TLS) to prevent replication fork collapse. TLS mechanisms are lesion- and species-specific, with prominent roles of specialized DNA polymerases with relaxed active sites. After incorporation of nucleotide(s) across from the lesion, the distorted primer termini are typically extended by DNA polymerase ζ (Pol ζ). As a result, Pol ζ is responsible for most DNA damage-induced mutations. Mechanisms of sequential polymerase switches and regulation of Pol ζ access to DNA in vivo remain unclear. Pol ζ shares two accessory subunits, called Pol31/Pol32 in yeast, with replicative Pol δ. Inclusion of Pol31/Pol32 in both holoenzymes requires a [4Fe-4S] cluster in the catalytic subunit C-terminal domains (CTDs). Disruption of the Pol ζ cluster or deletion of the POL32 gene attenuates induced mutagenesis. Here we describe a novel mutation affecting Pol ζ, rev3ΔC. Rev3∆C lacks the entire CTD, the binding platform for Pol31/Pol32. This mutation provides insight into regulation of polymerase switches and further defines regulatory roles of the Pol ζ CTD. rev3ΔC strains are partially proficient in Pol32-dependent UV-induced mutagenesis. This suggests a role for Pol32 in TLS beyond binding Pol ζ, related to Pol δ. We examined several TLS regulatory proteins, including Mgs1 which can compete with Pol32 for binding PCNA. Overproduction of Mgs1 suppressed induced mutagenesis, but had no effect in rev3ΔC suggesting Mgs1 exerts its inhibitory effect by acting specifically on Pol32 of Pol ζ. This evidence for differential regulation of Pol δ/ζ Pol32 emphasizes complexity of polymerase switches. Spectra of mutations induced by UV in rev3∆C were examined to further define the regulatory role of Pol ζ CTD. Rev3∆C produced different mutational spectra than WT, progressively deficient first in transversions/frameshifts, then transitions, and altered upon increasing UV doses. This supports a fine-tuned role for the CTD in regulating Pol ζ function and highlights differential mechanisms activated by different UV doses

The use of embolic signal detection in multicenter trials to evaluate antiplatelet efficacy: signal analysis and quality control mechanisms in the CARESS (Clopidogrel and Aspirin for Reduction of Emboli in Symptomatic carotid Stenosis) trial

<p><b>Background and Purpose:</b> The CARESS (Clopidogrel and Aspirin for Reduction of Emboli in Symptomatic carotid Stenosis) trial proved the effectiveness of the combination of clopidogrel and aspirin compared with aspirin alone in reducing presence and number of microembolic signals (MES) in patients with recently symptomatic carotid stenosis. The present study aimed at installing primary and secondary quality control measures in CARESS because MES evaluation relies on subjective judgment by human experts.</p> <p><b>Methods:</b> As primary quality control, centers participating in CARESS evaluated a reference digital audio tape (DAT) before the study containing both MES and artifacts. Interobserver agreement of classifying signals as MES was expressed as proportions of specific agreement of positive ratings (ps±values). For all DATs included in CARESS (n=300), online number of MES and off-line number of MES read by the central reader were compared using correlation coefficients. As secondary control, a sample of 16 of 300 DATs was cross-validated by another independent reader (post-trial validator).</p> <p><b>Results:</b> For the reference tape, the cumulative ps±value was 0.894 based on 12 of 14 observers. Two observers with very different results improved after a training procedure. Agreement between post-trial validator and central reader was ps+=0.805, indicating very good agreement. Correlation between online evaluation and off-line evaluation of DATs was very good overall (cumulative ρ=0.84; P<0.001).</p> <p><b>Conclusion:</b> Multicenter studies using MES as outcome parameter are feasible. However, primary and secondary quality control procedures are important.</p&gt

Modeling and analysis of an ankle-foot orthosis (AFO) using multibody methodologies

Biomechanics is the scientific domain which deals with the study of biological systems, such as the human body, using physical concepts and mechanical engineering methodologies. It allows the development of new medical devices and provides a quantitative analysis of the subject being studied. In the present work, the effect of an ankle foot orthosis (AFO) was studied on a healthy male subject. For this purpose, a biomechanical multibody 2D- model was developed in code MOBILE. The model was made of 9 rigid bodies connected by 9 frictionless hinged joints. Three additional degrees-of- freedom (DOFs) were added so the model can move freely in the plane. Kinematic data acquired in a gait lab were used as time functions to drive the joints and a foot model was designed based on three Hunt-Crossley’s spheres-plane contact model. The measured ankle kinematics was successfully reproduced using forward dynamics principles, for the stance phase period. In a first approach, barefoot kinematics was reproduced to define the foot model properties by adjusting manually the foot parameters and fitting the ankle angle. The ankle moment obtained in the gait lab was used to power the ankle joint. Then, the ankle-foot orthosis was added as a linear torsional spring element acting at the ankle joint and the moment powering the ankle joint was diminished. A manual optimization process was performed in order to fit the ankle ankle and it was concluded that the AFO reduces the muscle moment developed at the ankle in 15% and it can be simulated as a spring with k = 50 N.m/rad.Fundação para a Ciência e a Tecnologia (FCT

Seasonal variation of hip fractures in patients with Benign Paroxysmal Positional Vertigo

Introduction: Seasonal variation of benign paroxysmal positional vertigo (BPPV) presentation has been reported, with higher rates of presentation in months associated with times of lower serum vitamin D levels. The purpose of this study was to examine the association between the timing of hip fracture in patients with BPPV. Methods: A retrospective review (2013 to 2019) of adult patients was performed at a tertiary care academic center to identify patients with hip fracture due to ground level fall (ICD-10 code S72) and a previously established diagnosis of vestibular disorder (ICD-10 codes H81-83, A88.1, and R42). Included patients were matched by age and sex to control for patients who had hip fracture without a vestibular diagnosis. Patient charts were reviewed, and demographic and clinical data were extracted related to hip fracture and prior vestibular diagnosis. Groups were subdivided based on whether patients had a hip fracture from January to June versus July to December. Fisher’s exact test was used to evaluate for a difference in seasonal variation between groups. Results: There were 201 patients with vestibular disorders of whom 27 patients carried the diagnosis of BPPV, with a mean age of 80.4 years. The rates of hip fracture among patients with BPPV was higher in the period extending from January to June (63.0%) versus July to December (37.0%), [odds ratio 1.59, 95% CI 0.66-4.00]. The rate of hip fracture was not significantly different between these time periods for the control group (51.7% versus 48.3%) or the vestibular group (53.2% versus 46.8%). Conclusion: These results offer preliminary evidence that, in addition to an increased presentation for BPPV during months associated with decreased serum vitamin D, injuries due to BPPV may be increased as well. The present study is limited by the statistical power afforded by the small number of patients with BPPV and hip fracture that were identified

The pseudokinase MLKL mediates programmed hepatocellular necrosis independently of RIPK3 during hepatitis

Although necrosis and necroinflammation are central features of many liver diseases, the role of programmed necrosis in the context of inflammation-dependent hepatocellular death remains to be fully determined. Here, we have demonstrated that the pseudokinase mixed lineage kinase domain-like protein (MLKL), which plays a key role in the execution of receptor interacting protein (RIP) lcinase-dependent necroptosis, is upregulated and activated in human autoimmune hepatitis and in a murine model of inflammation-dependent hepatitis. Using genetic and pharmacologic approaches, we determined that hepatocellular necrosis in experimental hepatitis is driven by an MLKL-dependent pathway that occurs independently of RIPK3. Moreover, we have provided evidence that the cytotoxic activity of the proinflammatory cytokine IFN-gamma in hepatic inflammation is strongly connected to induction of MLKL expression via activation of the transcription factor STAT1. In summary, our results reveal a pathway for MLKL-dependent programmed necrosis that is executed in the absence of RIPK3 and potentially drives the pathogenesis of severe liver diseases

The impact of gender ideologies on men's and women's desire for a traditional or non-traditional partner

Two studies examine preferences for a long-term partner who conforms to traditional or non- traditional gender roles. The studies both demonstrate a link between benevolent sexism and preference for a traditional partner. However, Study 1 also demonstrates a strong preference among women for a non-traditional partner. We measured ambivalent sexist ideologies before introducing participants to either a stereotypically traditional or stereotypically non-traditional character of the opposite sex. In Study 1, women high in benevolence toward men reported a preference for a traditional man when compared to women low in benevolence toward men. We found no such link for hostility toward men. Study 2 showed that men high in benevolent sexism preferred a traditional woman more than men low in benevolent sexism. Again, this was not the case for hostile sexism. The studies provide evidence using both the Ambivalence Toward Men Inventory and the Ambivalent Sexism Inventory and demonstrate a relationship between benevolent ideology and partner choice that adds to a literature on partner preference which has to date been focused on preference dimensions of attractiveness and resources

Measurement of the proton and deuteron structure functions, F2p and F2d, and of the ratio sigma(L)/sigma(T)

The muon-proton and muon-deuteron inclusive deep inelastic scattering cross sections were measured in the kinematic range 0.002 < x < 0.60 and 0.5 < Q2 < 75 GeV2 at incident muon energies of 90, 120, 200 and 280 GeV. These results are based on the full data set collected by the New Muon Collaboration, including the data taken with a small angle trigger. The extracted values of the structure functions F2p and F2d are in good agreement with those from other experiments. The data cover a sufficient range of y to allow the determination of the ratio of the longitudinally to transversely polarised virtual photon absorption cross sections, R= sigma(L)/sigma(T), for 0.002 < x < 0.12 . The values of R are compatible with a perturbative QCD prediction; they agree with earlier measurements and extend to smaller x.Comment: In this replacement the erroneously quoted R values in tables 3-6 for x>0.12, and R1990 values in tables 5-6 for all x, have been corrected, and the cross sections in tables 3-4 have been adapted. Everything else, including the structure functions F2, remained unchanged. 22 pages, LateX, including figures, with two .sty files, and three separate f2tab.tex files for the F2-tables. Accepted for publication in Nucl.Phys.B 199

Length of carotid stenosis predicts peri-procedural stroke or death and restenosis in patients randomized to endovascular treatment or endarterectomy.

BACKGROUND: The anatomy of carotid stenosis may influence the outcome of endovascular treatment or carotid endarterectomy. Whether anatomy favors one treatment over the other in terms of safety or efficacy has not been investigated in randomized trials. METHODS: In 414 patients with mostly symptomatic carotid stenosis randomized to endovascular treatment (angioplasty or stenting; n = 213) or carotid endarterectomy (n = 211) in the Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS), the degree and length of stenosis and plaque surface irregularity were assessed on baseline intraarterial angiography. Outcome measures were stroke or death occurring between randomization and 30 days after treatment, and ipsilateral stroke and restenosis ≥50% during follow-up. RESULTS: Carotid stenosis longer than 0.65 times the common carotid artery diameter was associated with increased risk of peri-procedural stroke or death after both endovascular treatment [odds ratio 2.79 (1.17-6.65), P = 0.02] and carotid endarterectomy [2.43 (1.03-5.73), P = 0.04], and with increased long-term risk of restenosis in endovascular treatment [hazard ratio 1.68 (1.12-2.53), P = 0.01]. The excess in restenosis after endovascular treatment compared with carotid endarterectomy was significantly greater in patients with long stenosis than with short stenosis at baseline (interaction P = 0.003). Results remained significant after multivariate adjustment. No associations were found for degree of stenosis and plaque surface. CONCLUSIONS: Increasing stenosis length is an independent risk factor for peri-procedural stroke or death in endovascular treatment and carotid endarterectomy, without favoring one treatment over the other. However, the excess restenosis rate after endovascular treatment compared with carotid endarterectomy increases with longer stenosis at baseline. Stenosis length merits further investigation in carotid revascularisation trials