No abstract is provided for this article.
No abstract is provided for this article.
No abstract is provided for this article.
Acute exacerbations of COPD are the commonest cause of acute medical admissions in the UK, with ∼50% associated with bacterial infection. An acute bacterial insult is usually associated with increased recruitment and activation of neutrophils. COPD is characterized by airway neutrophilia; however, despite increased numbers of these cells, bacterial colonization persists. This study examined whether neutrophil phagocytosis was altered in COPD. Neutrophils were obtained from COPD, smoking and healthy subjects and phagocytosis of fluorescently-labelled polystyrene beads, Haemophilus influenzae (HI) or Streptococcus pneumoniae (SP) measured by flow cytometry. Neutrophils from all subjects ingested beads similarly showing that all cells were capable of phagocytosis. Neutrophils from all subjects phagocytosed SP with a maximum response at 5 min, however COPD neutrophils ingested significantly less SP (p
Although the standard model of star formation has served us well for over 20 years, its details are still a matter of debate. In particular, questions related to the effect of environment on star formation efficiency and the relative and absolute lifetimes of the different evolutionary phases are best answered by observations of large samples of cores. Such observations are only now becoming available, thanks to an impressive suite of new instruments that allow mapping studies in a reasonable time. Essential information such as whether cores are gravitationally bound or unbound, whether they are dominated by thermal or turbulent motions, and whether they are contracting or collapsing, or expanding, can only be obtained through molecular line observations. Isolated cores are the best places in which to study the star formation process, due to their simple nature and freedom from the confusing effects of crowded regions. We propose to map in N2H+, CS, and C18O, 40 cores that we have observed in the MIR and mm continuum. When combined with our existing data on 90 cores that probe different evolutionary stages, these data will provide the most complete, unbiased view of core evolution and the initial conditions for star formation.
Autonomic nerves influence airway tone by activating specific receptors on the target cells in the airways. The different components of the autonomic nervous system interact with each other, by affecting release of neurotransmitter, at ganglia in the airways, and by interaction at postjunctional receptors. Muscarinic receptors regulate mucus secretion from both submucosal glands and airway epithelial goblet cells. In the cholinergic pathway, acetylcholine released from postganglionic nerve endings stimulates muscarinic cholinergic receptors. Adrenergic mechanisms include sympathetic nerves that release noradrenaline and circulating adrenaline secreted from the adrenal medulla; these catecholamines activate α- and ß-adrenoceptors. Autoradiographic studies have revealed that ß-receptors are localized to many different cell types within the lung, including smooth muscle of all airways from trachea to terminal bronchioles, submucosal glands, airway epithelium and alveolar walls. Evidence has been found for a ß-receptor-mediated inhibition of cholinergic transmission in human and in dog airways. Changes in ß2-receptor function have been reported to occur in lung diseases, such as asthma.
