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The airway and cardiovascular effects of intravenous neurokinin A (NKA) and substance P (SP) were compared in six normal subjects. Both SP and NKA increased skin temperature (SkT) and heart rate (HR), but SP was more potent than NKA by factors of 6 and 20 respectively. No change in systolic blood pressure (BP) occurred with either peptide, but diastolic BP fell significantly with SP infusion. SP caused bronchodilation and NKA bronchoconstriction. NKA and SP have differing physiological roles and may activate different receptor populations.
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Increased concentrations of exhaled nitric oxide (NO) occur in patients with asthma, and exhaled NO may be useful for assessing the effect of drug therapy on airway inflammation. Beta2-agonists have been proposed to have both proinflammatory and anti-inflammatory effects. We therefore assessed exhaled NO after beta2-agonists in asthmatic patients. Two randomized, double-blind, placebo-controlled studies were conducted. Firstly, exhaled NO was measured in 18 asthmatics (9 taking inhaled glucocorticosteroids (GCS)) before and after nebulized salbutamol (5 mg), or identical placebo (0.9% saline). Exhaled NO and forced expiratory volume in one second (FEV1) were measured at 15 min intervals for 1 h (Study 1). Secondly, the effect of 1 week of treatment with the long-acting beta2-agonist, salmeterol (50 microg b.i.d.), added to either budesonide (800 microg b.i.d.) or placebo, was studied in eight mild asthmatic subjects (Study 2). Exhaled NO was measured by a chemiluminescence analyser, adapted for on-line recording. In Study 1, exhaled NO showed no significant change at any time-point in patients not taking inhaled GCS. In asthmatics on inhaled GCS, exhaled NO increased compared to placebo at 15 and 30 min, but this did not reach statistical significance. In Study 2, treatment with salmeterol increased FEV1, but exhaled NO levels were not significantly changed, either after budesonide treatment (143+/-35 to 179+/-67 ppb), or after placebo (201+/-68 to 211+/-65 ppb). Our results confirm that single high dose salbutamol does not increase exhaled nitric oxide in asthmatics not taking inhaled glucocorticosteroids. Salbutamol may increase exhaled nitric oxide in asthmatics taking inhaled glucocorticosteroids. However, regular use of salmeterol resulted in no change in exhaled nitric oxide, either used alone or in combination with inhaled glucocorticosteroids.
Chronic obstructive pulmonary disease (COPD) ranges amongst the commonest diseases in the world. The relentless progression of the disease causes a pressing need for a better understanding of and ther
Severe asthma is an important topic in respiratory diseases, due to its high impact on morbidity and mortality as well as on health-care resources. The many challenges that still exist in the management of the most difficult-to-treat forms of the disease, and the acknowledgement of the existence of unexplored areas in the pathophysiological mechanisms and the therapeutic targets represent an opportunity to gather experts in the field with the immediate goals to summarize current understanding about the natural history of severe asthma and to identify gaps in knowledge and research opportunities, with the aim to contribute to improved medical care and health outcomes. This article is a consensus document from the “International Course on Severe Asthma” that took place in Palermo, Italy, on May 10–11, 2019. Emerging topics in severe asthma were addressed and discussed among experts, with special focus on patient’s needs and research opportunities, with the aim to highlight the unanswered questions in the diagnostic process and therapeutic approach.
Chronic obstructive pulmonary disease (COPD) is a major global health problem which is increasing throughout the world and a major cause of death. However, current therapies fail to prevent disease progression or mortality. The mainstay of current drug therapy are long-acting bronchodilators; several longer-acting inhaled β<sub>2</sub>-agonists and muscarinic antagonists (and combinations) are now in development. No treatments have so far been shown to suppress chronic inflammation in COPD lungs. With better understanding of the inflammatory and destructive process in the pathophysiology of COPD, several new targets have been identified. Several mediator antagonists tested in COPD have so far been disappointing, but CXCR2 antagonists that block pulmonary neutrophil and monocyte recruitment may be more promising. Broad-spectrum anti-inflammatory drugs may be more effective, and include inhibitors of the enzymes phosphodiesterase-4, p38 mitogen-activated protein kinase, NF-ĸB kinase and phosphoinositide 3 kinase-γ and -δ, but side effects will be a major limitation so that inhaled delivery may be necessary. Perhaps the most promising approach is reversal of corticosteroid resistance through increasing histone deacetylase-2 activity. This might be achieved by theophylline-like drugs, phosphoinositide 3 kinase-δ inhibitors, more effective antioxidants and non-antibiotic macrolides.
The response of left ventricular function, coronary blood flow, and myocardial lactate metabolism during percutaneous transluminal coronary angioplasty (PTCA) was studied in a series of patients undergoing the procedure. From four to six balloon inflation procedures per patient were performed with an average duration per occlusion of 51 +/- 12 sec (mean +/- SD) and a total occlusion time of 252 +/- 140 sec. Analysis of left ventricular hemodynamics in 19 patients showed that the relaxation parameters, peak negative rate of change in pressure, and early time constants of relaxation, responded earliest to short-term coronary occlusion (peak effect at 17 +/- 7 sec) while other parameters, such as peak pressure, left ventricular end-diastolic pressure, and peak positive rate of change in pressure, responded more gradually, suggesting a progressive depression of myocardial mechanics throughout the procedure. Left ventricular angiograms, available for 14 patients, indicated an early onset of asynchronous relaxation concurrent with the early response in peak negative dP/dt and the time constant of early relaxation. All hemodynamic functions fully recovered within minutes after the end of PTCA. Mean blood flow in the great cardiac vein and proximal coronary sinus and the hyperemic response were measured in 20 patients. Before PTCA mean flow in the great cardiac vein was 69 +/- 17 ml/min and in the coronary sinus it was 129 +/- 34 ml/min. Reactive hyperemia (great cardiac vein) was 55% after the first PTCA and 91% after the third. A more pronounced reaction was observed when the residual functional coronary stenosis was reduced in subsequent dilatations. Arteriovenous lactate difference appeared constant during the first two occlusions (control +0.11 mmol/liter, first PTCA -0.87 mmol/liter, and second PTCA -0.82 mmol/liter) and did not increase during subsequent occlusions. Within minutes after the procedure lactate balance was again positive, demonstrating the reversibility of the metabolic disturbances after repeated ischemia. The results of this study indicate that there is no permanent dysfunction of global or regional myocardial mechanics, myocardial blood flow, or lactate metabolism after PTCA with four to six coronary occlusions of 40 to 60 sec.
We report Mopra Australia Telescope National Facility (ATNF), Anglo-Australian Telescope and Atacama Submillimeter Telescope Experiment observations of a molecular clump in Carina, BYF73 = G286.21+0.17, which give evidence of large-scale gravitational infall in the dense gas. From the millimetre and far-infrared data, the clump has a mass of ∼2 × 104 M⊙, luminosity of ∼2–3 × 104 L⊙ and diameter of ∼0.9 pc. From radiative transfer modelling, we derive a mass infall rate of ∼3.4 × 10−2 M⊙ yr−1. If confirmed, this rate for gravitational infall in a molecular core or clump may be the highest yet seen. The near-infrared K-band imaging shows an adjacent compact H ii region and IR cluster surrounded by a shell-like photodissociation region showing H2 emission. At the molecular infall peak, the K imaging also reveals a deeply embedded group of stars with associated H2 emission. The combination of these features is very unusual, and we suggest that they indicate the ongoing formation of a massive star cluster. We discuss the implications of these data for competing theories of massive star formation.
A new continuum map at 408 MHz is presented for a portion of the galactic plane near longitude 312°. Comparison with 5000-MHz measurements of similar angular resolution (several arcminutes), in both the radio continuum and hydrogen recombination lines, has allowed us to distinguish a hitherto unnoticed supernova remnant (SNR), G312.4–0.4, with angular diameter ~0°.5 and distance ~5 kpc. Other discrete sources on the map include: (i) a previously known SNR, G311.5–0.3; (ii) four sources that are non-thermal and most likely extragalactic; (iii) 16 H II regions, of which two are located in an extremely distant portion of the Carina spiral arm, ~ 16 kpc from the Sun, with galactocentric radius ~ 12.3 kpc.