Altered Baroreflex-Mediated Cardiovascular Responses to Acute Hypotension in Heart Failure Patients Compared to Healthy Adults

Patients with heart failure (HF) exhibit baroreflex dysfunction, which is associated with increased morbidity and mortality. Orthostatic hypotension, a decrease in blood pressure (BP) upon standing, is a condition that often occurs in HF, and may be linked with altered baroreflex responsiveness in this population. However, data on baroreflex-mediated cardiovascular responses to acute hypotension in HF patients are limited. Therefore, 8 HF patients (7 men; mean±SEM 65±3y; ejection fraction 30.5±3.1%) and 7 healthy control (CON) adults (6 men; 65±2y) underwent 7.5 minutes of unilateral lower-limb ischemia via inflation of a thigh cuff on one leg to non-pharmacologically induce acute hypotension upon cuff deflation. Beat-to-beat systolic BP, diastolic BP, and mean arterial BP (MAP; photoplethysmographic finger cuff) and heart rate (HR; electrocardiogram) were recorded continuously before, during, and after cuff inflation. Statistical analysis involved independent-samples t-tests. Baseline values were not different between groups (systolic BP: 128±8 vs. 128±4mmHg; diastolic BP: 73±3 vs. 82±5mmHg; MAP: 90±3 vs. 97±4mmHg; HR: 62±2 vs. 56±2b.min-1 for HF and CON, respectively; P\u3e0.05). The magnitude of the induced decrease in MAP was similar in both groups (HF -11±1 vs. CON -12±2mmHg; P\u3e0.05). However, the time-to-peak MAP decrease was significantly longer in HF compared to CON (HF 11±2 vs. CON 6±1s; PP\u3e0.05). However, the time-to-peak HR increase was longer in HF compared to CON (HF 9±1 vs. CON 6±1s; PP\u3e0.05). However, the time-to-peak HR increase was longer in HF compared to CON (HF 9±1 vs. CON 6±1s;

Evolution of genes and genomes on the Drosophila phylogeny

Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species

Evolution of genes and genomes on the Drosophila phylogeny

Affiliations des auteurs : cf page 216 de l'articleInternational audienceComparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species