Hetero-association of aromatic molecules in aqueous solution

Knowledge of the physical chemistry of small molecules complexation (the hetero-association) in aqueous solution is increasingly important in view of the rapidly emerging branch of supramolecular chemistry dealing with the formation of heterogeneous polymeric structures having specific functional roles. In this paper, the 50-year history of scientific studies of hetero-association of heterocyclic aromatic molecules in aqueous solution has been reviewed. Some important correlations of structural and thermodynamic parameters of complexation have been reported based on large data-set of hetero-association parameters accumulated to date. The fundamental problem of ‘energetic composition’ of π-stacking is extensively discussed. The review has shown that there are some gaps in our understanding of heteroassociation, which provides a challenge for further studies in this are

Macrophages, neutrophils and tumour necrosis factor-α expression in bronchiectatic airways in vivo

Bronchiectasis is increasingly being recognized as an inflammatory condition of the airways in which pathological permanent dilation occurs. We have obtained endobronchial biopsies in 14 patients with stable bronchiectasis and 15 control subjects. Airway neutrophils, macrophages and tumour necrosis factor-α (TNFα)-positive cells were stained with monoclonal antibodies and the densities of positive cells in the lamina propria were determined by using a computer image analyser. There was significantly higher neutrophil, macrophage and TNFα-positive cell densities in the lamina propria of bronchiectatic than control airways (P<0·001, P<0·001 and P=0·0002, respectively). Airway neutrophil density, in bronchiectasis but not in controls, correlated with TNFα-positive cell density (r=0·71, P=0·004). A significant correlation between airway macrophage and TNFα-positive cell densities was demonstrated in both control and bronchiectatic airways (r=0·63, P=0·016 and r=0·60, P=0·02 respectively). Neutrophil density negatively correlated with per cent forced vital capacity (FVC%) predicted among patients with bronchiectasis (r=-0·53, P=0·04). Bronchiectasis patients who were regular sputum producers had a significantly higher macrophage, but not neutrophil density, than their counterparts (P=0·02 and P=0·48 respectively). Our original findings suggest that airway macrophages could contribute to neutrophil influx into airway walls through their production of TNFα and therefore play an important role in the pathogenesis of bronchiectasis. © 2001 Harcourt Publishers Ltd.link_to_subscribed_fulltex