Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference

Prospective study of measles in hospitalized, human immunodeficiency virus (HIV)-infected and HIV-uninfected children in Zambia.

Measles in persons coinfected with human immunodeficiency virus (HIV) has been reported to be unusual in its presentation and frequently fatal. To determine the effect of HIV coinfection on the clinical features and outcome of measles, a prospective study of hospitalized children with measles was conducted between January 1998 and October 2000 in Lusaka, Zambia. One-sixth (17%) of 546 children hospitalized with laboratory-confirmed measles were coinfected with HIV. One-third of the HIV-infected children hospitalized with confirmed measles were <9 months old, compared with 23% of HIV-uninfected children (P=.03). Few differences in clinical manifestations, complications, or mortality were found between HIV-infected and HIV-uninfected children with measles. HIV-infected children constitute a significant proportion of children hospitalized with measles in countries with high HIV prevalence and are more likely to be younger than the age for routine measles immunization