82 research outputs found
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
Struktuurinflasie in Suid-Afrika
M.Com. (Economics)This study looked into the possible presence of structural inflation in South Africa. The South African rate of inflation has, by the time this study was undertaken, showed resistance to reduce in the face of several years of demand management policies. It was this resistance that led to the idea that the South African inflation rate might be the result of several structural factors in the economy. The study was done in three separate stages. In the first, a study of the conventional theories of inflation, the demand-pull and cost push theories, was done. The main objective was to establish whether inflation could be controlled by the medicine these theories prescribed. In section two, the different schools of thought as regards the structural approach to inflation were analyzed. The structuralist school, developed during the late 1950s, described inflation as the result of productivity discrepancies mainly between the agricultural and industrial sectors. The structural school, which developed during the early 1970s has two variations. The first, the Scandinavian variant, ascribes inflation to the existing productivity gap between the international competing sectors and the domestic sectors, whilst no corresponding gap in salaries between the relevant sectors exists. The second variant designates inflation to the gap existing between the labour productivity in the public and private sectors. Here again, no such salary gap exists between the sectors. The last structural inflation school of thought discussed was the one prevailing in the USA. This school saw inflation as the result of the unproductive use of capital and labour when measured against the incomes generated by the same factors of production. In section three of the study, the abovementioned theories of structural inflation were empirically applied in the South African context. In all cases very definite pointers, indicating the applicability ·of these theories in the South African situation were found. In all cases two main sector groups were constructed; each consisted as the sum of the weighted productivity of wages of the sectors belonging to that sector group i.e. internationally or domestically competitive and public or private competing groups. The constructed series for labour productivity and wages and salaries for the different sector groups were then compared
Life extension properties of superoxide dismutase mimics arise from 'calorie restriction'
AbstractManganese-salen superoxide dismutase mimics interfere with the mitochondrial electron transport chain by acting as antimetabolites and thus effect “calorie restriction,” leading to extended lifespan
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