95 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
Metastatic melanoma of the heart.
BACKGROUND: Malignant melanoma has an unpredictable biologic behavior and is the neoplasm with the greatest propensity for cardiac involvement. Although relatively frequent at autopsy, cardiac metastases are rarely identified antemortem. METHODS: We reviewed 2,810 patients with histologically confirmed malignant melanoma, who were diagnosed and followed up by our clinic. Clinical, histological, and imaging data are presented. RESULTS: Five cases of metastatic melanoma of the heart were identified out of 314 melanoma patients with visceral involvement. One case of a 53-year-old woman, who died unexpectedly during her first chemotherapy course, is described in detail. Postmortem examination determined the cause of death to be the presence of multiple melanoma metastases in the heart, even though the patient had shown no signs of cardiac involvement. CONCLUSIONS: The unpredictable biologic behavior of melanoma may lead to unusual metastatic sites, and, therefore, the heart also should be included in routine examinations
Disseminated Kaposi's sarcoma associated with idiopathic CD4+ lymphocytopenia and low dose steroid therapy
A case of disseminated Kaposi sarcoma in a 76-year-old woman treated with low-dose steroids for a seronegative polyarthritis is described. HIV serology was negative, whereas PCR for HHV-8 was positive. The patient presented with a profound reduction in the peripheral blood CD4+ cell count and a decrease in serum immunoglobulins and was diagnosed as having idiopathic CD4+ lymphocytopenia. The clinical picture was characterized by limited cutaneous lesions with typical features of KS associated with widespread visceral involvement and unusually aggressive behaviour
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