Search

An imbalance in autonomic nervous system (ANS) activity may play a role in asthma, but it is unclear whether this is associated with specific pathophysiology. This study assessed ANS activity by measuring heart rate variability (HRV) in eosinophilic (EA) and non-eosinophilic asthma (NEA) and people without asthma. HRV, combined hypertonic saline challenge/sputum induction, exhaled nitric oxide (FeNO), skin prick tests to measure atopy, and spirometry tests were conducted in teenagers and young adults (14–21 years) with (n = 96) and without (n = 72) generally well-controlled asthma. HRV parameters associated with sympathetic and parasympathetic ANS branches were analyzed. EA and NEA were defined using a 2.5% sputum eosinophil cut-point. Airway hyperreactivity (AHR) was defined as ≥15% reduction in FEV1 following saline challenge. HRV parameters did not differ between asthmatics and non-asthmatics or EA and NEA. They were also not associated with markers of inflammation, lung function or atopy. However, increased absolute low frequency (LFµs2; representing increased sympathetic nervous system (SNS) activity) was found in asthmatics who used β-agonist medication compared to those who did not (median: 1611, IQR 892–3036 vs 754, 565–1592; p < 0.05) and increased normalized low frequency (LF nu) was found in those with AHR compared to without AHR (64, 48–71 vs 53, 43–66; p < 0.05). ANS activity (as measured using HRV analysis) is not associated with pathophysiology or inflammatory phenotype in young asthmatics with generally well-controlled asthma. However, enhanced SNS activity can be detected in asthmatics with AHR or who use β-agonist medication. [ABSTRACT FROM AUTHOR]

One of the criteria for selecting a suitable natural enemy is its functional response to different densities of the host.Habrobracon hebetor(Say) is a larval ectoparasitoid of several species of lepidopteran. Functional response ofH. hebetor, after treatment with LC25of chlorpyrifos and fenpropathrin in three stages, was assessed to different densities of fifth instar ofEphestia kuehniella(2, 4, 8, 16, 32 and 64). LC25values were estimated to be 0.043, 5.36 and 2.00 and 0.38, 13.9 and 4.45 mg a.i. l−1for the larval, pupal and adult stages for chlorpyrifos and fenpropathrin, respectively. Host densities were offered to treated wasps for 24 h. Experiments were replicated 10 times. The results showed that the functional responses of wasps in control as well as immature stages treatments were Type III, whereas those of adult stage were Type II.a(Type II) orb(Type III) andThparameters were evaluated with Roger’s equation.bandThin control were assessed to be 0.0129 and 0.1723 h, respectively. These parameters were estimated in chlorpyrifos and fenpropathrin to be 0.0052, 0.00718 and 0.1945, 0.2492 h in larval stage; 0.00817, 0.00916 and 0.2736, 0.3108 h in pupal stage; andaandThwere 0.0064, 0.0137 h−1and 0.2492, 0.2242 h in the adult stage, respectively. The insecticide had no significant effect on the searching efficiency ofH. hebetorcompared with those treated in control; however, they had significant effect on the handling time of the parasitoid and increased it, except in the larval stage treated with chlorpyrifos treatment. [ABSTRACT FROM AUTHOR]