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

Change in platelet endothelial cell adhesion molecule-1 immunoreactivity in the dentate gyrus in gerbils fed a folate-deficient diet

Folate deficiency increases stroke risk. We examined whether folate deficiency affects platelet endothelial cell adhesion molecule-1 (PECAM-1), which is an immunoglobulin-associated cell adhesion molecule and mediates the final common pathway of neutrophil transendothelial migration, in blood vessels in the gerbil dentate gyrus after transient forebrain ischemia. Gerbils were exposed to a folic acid-deficient diet (FAD) for 3 months and then subjected to common carotid artery occlusion for 5 min. In the control diet (CD)- and FAD-treated sham-operated groups, weak PECAM-1 immunoreactivity was detected in the blood vessels located in the dentate gyrus. PECAM-1 immunoreactivity in both groups was increased by 4 days after ischemic insult. PECAM-1 immunoreactivity in the FAD-treated group was twice as high that in the CD-treated-sham-operated group 4 days after ischemic insult. Western blot analyses showed that the change patterns in PECAM-1 protein levels in the dentate gyrus in both groups after ischemic insult were similar to changes in PECAM-1 immunohistochemistry in the ischemic dentate gyrus. Our results suggest that folate deficiency enhances PECAM-1 in the dentate gyrus induced by transient ischemia

Political exchange and the voting franchise: universal democracy as an emergent process

Democracy, Voting franchise, Political exchange, Constrained government, H4, D7,

Natural law, state formation and the foundations of social theory

This article proceeds from the claim that the earliest examples of sociological method were linked by a critique of the theories of natural law proposed in the Enlightenment. It illustrates this point by surveying the rise of social theory in the aftermath of the French Revolution and by examining approaches to natural law in key texts in the history of sociology. However, the article claims that natural law remains a blind spot for sociological method, and the original sociological dismissal of natural law as a formal body of normative postulates has prevented the formation of sociology as a comprehensive system of social interpretation. Using a series of historical examples, the article then argues that natural law theory needs in itself to be viewed sociologically, and, throughout modern history, ius-natural thinking has served not only to establish formal norms for evaluating social and political practices, but also to form the positive preconditions for the evolution of contemporary society in its distinctive differentiated form. The article concludes by arguing that a sociological reconstruction of natural law points the way towards a sociological theory of theory, which has typically proved elusive for sociological methodologies