34 research outputs found
Genome-wide data from medieval German Jews show that the Ashkenazi founder event pre-dated the 14th century
We report genome-wide data for 33 Ashkenazi Jews (AJ), dated to the 14th century, following a salvageexcavation at the medieval Jewish cemetery of Erfurt, Germany. The Erfurt individuals are geneticallysimilar to modern AJ and have substantial Southern European ancestry, but they show more variabilityin Eastern European-related ancestry than modern AJ. A third of the Erfurt individuals carried the samenearly-AJ-specific mitochondrial haplogroup and eight carried pathogenic variants known to affect AJtoday. These observations, together with high levels of runs of homozygosity, suggest that the Erfurtcommunity had already experienced the major reduction in size that affected modern AJ. However, theErfurt bottleneck was more severe, implying substructure in medieval AJ. Together, our results suggestthat the AJ founder event and the acquisition of the main sources of ancestry pre-dated the 14th centuryand highlight late medieval genetic heterogeneity no longer present in modern AJ
Sympathetic Activation and Baroreflex Function during Intradialytic Hypertensive Episodes
BACKGROUND: The mechanisms of intradialytic increases in blood pressure are not well defined. The present study was undertaken to assess the role of autonomic nervous system activation during intradialytic hypertensive episodes. METHODOLOGY/PRINCIPAL FINDINGS: Continuous interbeat intervals (IBI) and systolic blood pressure (SBP) were monitored during hemodialysis in 108 chronic patients. Intradialytic hypertensive episodes defined as a period of at least 10 mmHg increase in SBP between the beginning and the end of a dialysis session or hypertension resistant to ultrafiltration occurring during or immediately after the dialysis procedure, were detected in 62 out of 113 hemodialysis sessions. SBP variability, IBI variability and baroreceptor sensitivity (BRS) in the low (LF) and high (HF) frequency ranges were assessed using the complex demodulation technique (CDM). Intradialytic hypertensive episodes were associated with an increased (n = 45) or decreased (n = 17) heart rate. The maximal blood pressure was similar in both groups. In patients with increased heart rate the increase in blood pressure was associated with marked increases in SBP and IBI variability, with suppressed BRS indices and enhanced sympatho-vagal balance. In contrast, in those with decreased heart rate, there were no significant changes in the above parameters. End-of-dialysis blood pressure in all sessions associated with hypertensive episode was significantly higher than in those without such episodes. In logistic regression analysis, predialysis BRS in the low frequency range was found to be the main predictor of intradialytic hypertension. CONCLUSION/SIGNIFICANCE: Our data point to sympathetic overactivity with feed-forward blood pressure enhancement as an important mechanism of intradialytic hypertension in a significant proportion of patients. The triggers of increased sympathetic activity during hemodialysis remain to be determined. Intradialytic hypertensive episodes are associated with higher end-of-dialysis blood pressure, suggesting that intradialytic hypertension may play a role in generation of interdialytic hypertension
Modeling Motor Learning Using Heteroscedastic Functional Principal Components Analysis
<p>We propose a novel method for estimating population-level and subject-specific effects of covariates on the variability of functional data. We extend the functional principal components analysis framework by modeling the variance of principal component scores as a function of covariates and subject-specific random effects. In a setting where principal components are largely invariant across subjects and covariate values, modeling the variance of these scores provides a flexible and interpretable way to explore factors that affect the variability of functional data. Our work is motivated by a novel dataset from an experiment assessing upper extremity motor control, and quantifies the reduction in movement variability associated with skill learning. The proposed methods can be applied broadly to understand movement variability, in settings that include motor learning, impairment due to injury or disease, and recovery. Supplementary materials for this article are available online.</p
MA04.07 Comparative Clinical Outcomes for Patients with NSCLC Harboring EGFR Exon 20 Insertion Mutations and Common EGFR Mutations
Introduction: Approximately 85–90% of the mutations seen in EGFR-mutant non-small cell lung cancers (NSCLCs) are common mutations (cEGFR), Exon 19 deletions and Exon 21 L858R. Up to 10% of EGFR-mutant NSCLC harbors Exon 20 insertion mutations (Exon20ins). We conducted a retrospective cohort study using real-world data to compare clinical outcomes between patients harboring Exon20ins and cEGFR.
Methods: This retrospective cohort study included patients from the Flatiron Health database (1 January 2011 through 31 May 2020) who had advanced NSCLC. The objectives of the study were to assess the prognostic value of Exon20ins compared with cEGFR (start date of first-line therapy as the index date) and the effect of tyrosine kinase inhibitor (TKI) treatment between the groups (start date of first TKI line as the index date). Analysis was stratified by line of TKI use. Endpoints included real-world overall survival (rwOS), progression-free survival (rwPFS), and time to next therapy (rwTTNT) and were analyzed using multivariable Cox proportional hazards model and summarized by Kaplan-Meier method.
Results: Among 62,464 patients with advanced NSCLC, 181 with Exon20ins and 2833 with cEGFR met eligibility criteria. Population demographics between the groups were comparable with minor exceptions. With median 34-month follow-up, Exon20ins was associated with a 75% increased risk of death (adjusted hazard ratio [adjHR] of 1.75 [95%CI, 1.45–2.13]; p˂0.0001); median rwOS was 16.23 (95%CI, 11.04–19.38) for Exon20ins and 25.49 months (95%CI, 24.48–27.04) for cEGFR (Table). The estimated 5-year survival rate for Exon20ins is 8% compared with 19% for cEGFR. The predictive value of TKI treatment, stratified by line, was assessed in 76 Exon20ins and 2749 cEGFR patients who were treated with TKIs. With median 20.6-month follow-up, there was a 170% increase in risk of progression or death associated with Exon20ins (adjHR of 2.7 [95% CI, 2.06–3.55]; p˂0.0001); median rwPFS was 2.86 months (95%CI, 2.14–3.91) compared with 10.45 months (95%CI: 10.05–10.94) for cEGFR. Furthermore, there was a 170% increased risk of death (adjHR of 2.70 [95% CI, 2.04–3.57]; p˂0.0001) associated with Exon20ins; median rwOS was 7.46 months (95%CI, 5.45–13.34) for Exon20ins and 25.49 months (95%CI, 24.28–26.81) for cEGFR (Table).
Conclusion: Patients with Exon20ins have a worse prognosis compared with patients with cEGFR. Furthermore, EGFR TKI treatment was substantially less effective for patients with Exon20ins, as the risk of disease progression and mortality was higher compared with patients with cEGFR. These findings highlight the need for new treatment options for Exon20ins