The effect of nose clip on exercise-induced bronchoconstriction in adolescents.

BACKGROUND: Oral breathing is considered to increase hyper-responsiveness of the airways. Data on the need for nose clip (NC) during exercise challenge test (ECT) in children and adolescents is scarce. Ouraim was to evaluate the role of NC during ECT in children and adolescents. METHODS: A prospective, cohort study; children referred for ECT were evaluated on two separate visits, with and without a NC. Demographic, clinical data and measurements of lung functions were recorded. Allergy and asthma control were evaluated by Total Nasal Symptoms Score (TNSS) and Asthma Control Test (ACT) questionnaires. RESULTS: Sixty children and adolescents (mean age 16.7 ± 1.1 years, 38% Female,) performed ECT with NC and 48 (80%) completed visit 2 (ECT without NC), 8.7 ± 7.9 days after visit 1. Following exercise, 29/48 patients (60.4%) with NC had a decline of ≥12% in forced expiratory volume in the first second (FEV1 ) (positive ECT) compared to only 16/48 (33.3%) positive tests without NC (p = 0.0008). Test result was changed in 14 patients from positive ECT (with NC) to negative ECT (no NC) and in only one patient from negative to positive. The use of NC resulted in greater FEV1 decline (median 16.3% predicted, IQR 6.0-19.1% predicted vs. median 4.5% predicted, IQR 1.6-18.4% predicted, p = 0.0001), and better FEV1 increase after bronchodil at or inhalation compared to ECT without NC. Higher TNSS scores did not predict higher probability to positive ECT. CONCLUSIONS: The use of NC during ECT increases detection rate of exercise induced bronchoconstriction during ECT in the pediatric population. These findings strengthen the recommendation of nasal blockage during ECT in children and adolescents.

SARS-CoV-2 variants with reduced infectivity and varied sensitivity to the BNT162b2 vaccine are developed during the course of infection.

In-depth analysis of SARS-CoV-2 quasispecies is pivotal for a thorough understating of its evolution during infection. The recent deployment of COVID-19 vaccines, which elicit protective anti-spike neutralizing antibodies, has stressed the importance of uncovering and characterizing SARS-CoV-2 variants with mutated spike proteins. Sequencing databases have allowed to follow the spread of SARS-CoV-2 variants that are circulating in the human population, and several experimental platforms were developed to study these variants. However, less is known about the SARS-CoV-2 variants that are developed in the respiratory system of the infected individual. To gain further insight on SARS-CoV-2 mutagenesis during natural infection, we preformed single-genome sequencing of SARS-CoV-2 isolated from nose-throat swabs of infected individuals. Interestingly, intra-host SARS-CoV-2 variants with mutated S genes or N genes were detected in all individuals who were analyzed. These intra-host variants were present in low frequencies in the swab samples and were rarely documented in current sequencing databases. Further examination of representative spike variants identified by our analysis showed that these variants have impaired infectivity capacity and that the mutated variants showed varied sensitivity to neutralization by convalescent plasma and to plasma from vaccinated individuals. Notably, analysis of the plasma neutralization activity against these variants showed that the L1197I mutation at the S2 subunit of the spike can affect the plasma neutralization activity. Together, these results suggest that SARS-CoV-2 intra-host variants should be further analyzed for a more thorough characterization of potential circulating variants.

Changes in the monocytic subsets CD14(dim)CD16(+) and CD14(++)CD16(-) in chronic systolic heart failure patients.

Different monocytic subsets are important in inflammation and tissue remodelling, but although heart failure (HF) is associated with local and systemic inflammation, their roles in HF are yet unknown. We recruited 59 chronic systolic HF patients (aged 58 ± 13 years, 45 males and 14 females) and 29 age-matched controls with no pervious heart disease. Compared to the controls, we found no change in the distribution of the CD14(+)CD16(+) monocytic subset, whereas the classical CD14(++)CD16(-) subset was decreased by 11% (P < 0.001), and the nonclassical CD14(dim)CD16(+) subset was expanded by 4% (P < 0.001) in HF patients and was inversely associated with severe HF (P = 0.015), as assessed by increased end-diastolic dimension (EDD). Compared to the control group, serum TNFα, IL-1ß, IL-10, and IL-13 levels were significantly elevated in the HF patients. Specifically, IL-13 levels were positively correlated to the CD1CD14(dim)CD16(+) monocytic subset (r = 0.277, P = 0.017), and intracellular staining of IL-13 demonstrated that some of these monocytes produce the cytokine in HF patients, but not in the controls. We suggest that the inverse association between EDD values and the expansion of CD14(dim)CD16(+) monocytes that can produce IL-13 could be explained as a measure to counterbalance adverse remodelling, which is a central process in HF.