Attenuation of atrial natriuretic peptide response to sodium loading after cardiac operation

To evaluate the role of cardiac operation and the atrial appendage in secretion of atrial natriuretic peptide in response to sodium loading, we studied 44 patients who underwent heart operations with (28 patients; group I) or without (16 patients; group II) right atrial appendectomy and 16 patients who underwent lobectomy (group III). Before and after operation 1 ml/kg of 10% NaCl was infused for 15 minutes. Blood samples were taken before NaCl infusion and immediately after infusion and at 60 minutes after infusion. There were no significant changes in hemodynamics or hematocrit level throughout the study. Plasma and urine sodium levels and the fractional excretion of sodium were significantly increased by sodium loading. Before operation, plasma mean atrial natriuretic peptide levels increased markedly in response to sodium infusion in all groups. After operation, this atrial natriuretic peptide response disappeared in groups I and II, but remained present in group III. Elution profiles of plasma atrial natriuretic peptide showed that the major peak coincided with α-atrial natriuretic peptide before sodium loading, whereas a β-atrial natriuretic peptide peak appeared 60 minutes after sodium loading in all groups both before and after operation. The mean plasma arginine vasopressin levels were significantly increased by sodium loading both before and after operation in all groups. Sodium loading decreased the mean plasma aldosterone levels in all groups before operation, but did not after operation in groups I and II. Plasma renin activity and angiotensin II concentrations were not changed by sodium loading. We conclude that atrial natriuretic peptide response to sodium loading is attenuated by cardiac operation irrespective of right appendectomy, but not by lobectomy. Sodium loading augments secretion of β-atrial natriuretic peptide even in reduced atrial natriuretic peptide response states after heart operations

Th2-predominant inflammation and blockade of IFN-γ signaling induce aneurysms in allografted aortas

Abdominal aortic aneurysms (AAAs) cause death due to complications related to expansion and rupture. The underlying mechanisms that drive AAA development remain largely unknown. We recently described evidence for a shift toward T helper type 2 (Th2) cell responses in human AAAs compared with stenotic atheromas. To evaluate putative pathways in AAA formation, we induced Th1- or Th2-predominant cytokine environments in an inflammatory aortic lesion using murine aortic transplantation into WT hosts or those lacking the receptors for the hallmark Th1 cytokine IFN-γ, respectively. Allografts in WT recipients developed intimal hyperplasia, whereas allografts in IFN-γ receptor–deficient (GRKO) hosts developed severe AAA formation associated with markedly increased levels of MMP-9 and MMP-12. Allografts in GRKO recipients treated with anti–IL-4 antibody to block the characteristic IL-4 Th2 cytokine or allografts in GRKO hosts also congenitally deficient in IL-4 did not develop AAA and likewise exhibited attenuated collagenolytic and elastolytic activities. These observations demonstrate an important dichotomy between cellular immune responses that induce IFN-γ– or IL-4–dominated cytokine environments. The findings establish important regulatory roles for a Th1/Th2 cytokine balance in modulating matrix remodeling and have important implications for the pathophysiology of AAAs and arteriosclerosis

Salusins: Potential Use as a Biomarker for Atherosclerotic Cardiovascular Diseases

Human salusin-α and salusin-β are related peptides produced from prosalusin. Bolus injection of salusin-β into rats induces more profound hypotension and bradycardia than salusin-α. Central administration of salusin-β increases blood pressure via release of norepinephrine and arginine-vasopressin. Circulating levels of salusin-α and salusin-β are lower in patients with essential hypertension. Salusin-β exerts more potent mitogenic effects on human vascular smooth muscle cells (VSMCs) and fibroblasts than salusin-α. Salusin-β accelerates inflammatory responses in human endothelial cells and monocyte-endothelial adhesion. Human macrophage foam cell formation is stimulated by salusin-β but suppressed by salusin-α. Chronic salusin-β infusion into apolipoprotein E-deficient mice enhances atherosclerotic lesions; salusin-α infusion reduces lesions. Salusin-β is expressed in proliferative neointimal lesions of porcine coronary arteries after stenting. Salusin-α and salusin-β immunoreactivity have been detected in human coronary atherosclerotic plaques, with dominance of salusin-β in macrophage foam cells, VSMCs, and fibroblasts. Circulating salusin-β levels increase and salusin-α levels decrease in patients with coronary artery disease. These findings suggest that salusin-β and salusin-α may contribute to proatherogenesis and antiatherogenesis, respectively. Increased salusin-β and/or decreased salusin-α levels in circulating blood and vascular tissue are closely linked with atherosclerosis. Salusin-α and salusin-β could be candidate biomarkers and therapeutic targets for atherosclerotic cardiovascular diseases

Efficacy and safety of single-dose ivermectin in mild-to-moderate COVID-19: the double-blind, randomized, placebo-controlled CORVETTE-01 trial

BackgroundTo investigate whether ivermectin inhibits SARS-CoV-2 proliferation in patients with mild-to-moderate COVID-19 using time to a negative COVID-19 reverse transcription-polymerase chain reaction (RT-PCR) test.MethodsCORVETTE-01 was a double-blind, randomized, placebo-controlled study (August 2020–October 2021) conducted in Japan. Overall, 248 patients diagnosed with COVID-19 using RT-PCR were assessed for eligibility. A single oral dose of ivermectin (200  μg/kg) or placebo was administered under fasting. The primary outcome was time to a negative COVID-19 RT-PCR test result for SARS-CoV-2 nucleic acid, assessed using stratified log-rank test and Cox regression models.ResultsOverall, 112 and 109 patients were randomized to ivermectin and placebo, respectively; 106 patients from each group were included in the full analysis set (male [%], mean age: 68.9%, 47.9 years [ivermectin]; 62.3%, 47.5 years [placebo]). No significant difference was observed in the occurrence of negative RT-PCR tests between the groups (hazard ratio, 0.96; 95% confidence interval [CI] 0.70–1.32; p = 0.785). Median (95% CI) time to a negative RT-PCR test was 14.0 (13.0–16.0) and 14.0 (12.0–16.0) days for ivermectin and placebo, respectively; 82.1% and 84% of patients achieved negative RT-PCR tests, respectively.ConclusionIn patients with COVID-19, single-dose ivermectin was ineffective in decreasing the time to a negative RT-PCR test.Clinical Trial RegistrationClinicalTrials.gov, NCT04703205