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001-es BibID:	BIBFORM023040
Első szerző:	Balla József (belgyógyász, nephrológus)
Cím:	Ferriporphyrins and endothelium : a 2-edged sword-promotion of oxidation and induction of cytoprotectants / Balla, J., Balla, G., Jeney, V., Kakuk, G., Jacob, H. S., Vercellotti, G. M.
Dátum:	2000
ISSN:	0006-4971
Megjegyzések:	Heme arginate infusions blunt the symptoms of patients with acute intermittent porphyria without evidence of the vascular or thrombotic side effects reported for hematin, To provide a rationale for heme arginate's safety, the present study examined the effects of various ferriporphyrins to sensitize human endothelial cells to free radical injury and to induce heme oxygenase and ferritin expression. Heme arginate, unlike hematin, did not amplify oxidant-induced cytotoxicity mediated by hydrogen peroxide (5.3 +/- 2.4 versus 62.3 +/- 5.3% Cr-51 release, P < .0001) or by activated neutrophils (14.4 +/- 2.9 versus 41.1 +/- 6.0%, P < .0001), Nevertheless, heme arginate efficiently entered endothelial cells similarly to hematin, since both markedly induced heme oxygenase mRNA (more than 20-fold increase) and enzyme activity. Even with efficient permeation, endothelial cell ferritin content was only minimally increased by heme arginate compared with a 10-fold induction by hematin; presumably less free iron was derived from heme arginate despite up-regulation of heme oxygenase, Hematin is potentially vasculopathic by its marked catalysis of oxidation of low-density lipoprotein (LDL) to endothelial-toxic moieties, Heme arginate was significantly less catalytic. Heme arginate-conditioned LDL was less than half as cytotoxic to endothelial cells as hematin-conditioned LDL (P < .004), It is concluded that heme arginate may be less vasculotoxic than hematin since it is an effective heme oxygenase gene regulator but a less efficient free radical catalyst.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Blood. - 95 : 11 (2000), p. 3442-3450. -
További szerzők:	Balla György (1953-) (csecsemő és gyermekgyógyász, neonatológus) Jeney Viktória (1971-) (vegyész, kémia tanár) Kakuk György (1938-2018) (belgyógyász) Jacob, Harry S. Vercellotti, Gregory M.
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM023038
Első szerző:	Jeney Viktória (vegyész, kémia tanár)
Cím:	Pro-oxidant and cytotoxic effects of circulating heme / Jeney V., Balla J., Yachie A., Varga Zs., Vercellotti G. M., Eaton J. W., Balla G.
Dátum:	2002
ISSN:	0006-4971
Megjegyzések:	Numerous pathologies may involve toxic side effects of free heme and hemederived iron. Deficiency of the hemecatabolizing enzyme, heme oxygenase-1 (HO-1), in both a human patient and transgenic knockout mice leads to an abundance of circulating heme and damage to vascular endothelium. Although heme can be directly cytotoxic, the present investigations examine the possibility that hemoglobin-derived heme and iron might be indirectly toxic through the generation of oxidized forms of low-density lipoprotein (LDL). In support, hemoglobin in plasma, when oxidized to methemoglobin by oxidants such as leukocyte-derived reactive oxygen, causes oxidative modification of LDL. Heme, released from methemogiobin, catalyzes the oxidation of LDL, which in turn induces endothelial cytolysis primarily caused by lipid hydroperoxides. Exposure of endothelium to sublethal concentrations of this oxidized LDL leads to induction of both HO-1 and ferritin. Similar endothelial cytotoxicity was caused by LDL isolated from plasma of an HO-1-deficient child. Spectral analysis of the child's plasma revealed a substantial oxidation of plasma hemoglobin to methemoglobin. Iron accumulated in the HO-1-deficient child's LDL and several independent assays revealed oxidative modification of the LDL. We conclude that hemoglobin, when oxidized in plasma, can be. indirectly cytotoxic through the generation of oxidized LDL by released heme and that, in response, the intracellular defense-HO-1 and ferritin-Is induced. These results may be relevant to a variety of disorders-such as renal failure associated with intravascular hemolysis, hemorrhagic injury to the central nervous system, and, perhaps, atherogenesis-in which hemoglobin-derived heme may promote the formation of fatty acid hydroperoxides.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk
Megjelenés:	Blood. - 100 : 3 (2002), p. 879-887. -
További szerzők:	Balla József (1959-) (belgyógyász, nephrológus) Yachie, Akihiro Varga Zsuzsa (1951-) (biokémikus, nephrológus) Vercellotti, Gregory M. Eaton, John W. Balla György (1953-) (csecsemő és gyermekgyógyász, neonatológus)
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001-es BibID:	BIBFORM040452
035-os BibID:	PMID:8087243
Első szerző:	Vercellotti, Gregory M.
Cím:	Heme and the vasculature : an oxidative hazard that induces antioxidant defenses in the endothelium / Gregory M. Vercellotti, György Balla, József Balla, Karl Nath, John W. Eaton, Harry S. Jacob
Dátum:	1994
ISSN:	1073-1199
Megjegyzések:	Heme proteins transport oxygen and facilitate redox reactions. Heme, however, may be dangerous, especially when free in biologic systems. For example, iron released from hemoglobin-derived heme can catalyze oxidative injury to neuronal cell membranes and may be a factor in post-traumatic damage to the central nervous system. We have shown that heme catalyzes the oxidation of low density lipoproteins which can damage vascular endothelial cells. The endothelium is susceptible to damage by oxidants generated by activated phagocytes, and this has been invoked as an important mechanism in a number of pathologies including the Adulte Respiratory Distress Syndrome (ARDS), acute tubular necrosis, reperfusion injury and atherosclerosis. Because of its highly hydrophobic nature, heme readily intercalates into endothelial membranes and potentiates oxidant-mediated damage. This injury is dependent on the iron content of heme and is completely blocked when concomitant hemopexin is added. Ferrohemoglobin, when added to cultured endothelial cells, is without deleterious effects, but if oxidized to ferrihemoglobin (methemoglobin), it greatly amplifies oxidant damage. Methemoglobin, but not ferrohemoglobin, releases its hemes which can then be incorporated into endothelial cells. Cultured endothelial cells, when exposed to methemoglobin but not ferrohemoglobin, cytochrome c or metmyoglobin, potentiate this oxidant injury. Stabilization of the methemoglobin by cyanide, haptoglobin or capture of the heme by hemopexin abrogates this effect. Paradoxically, more prolonged exposure of endothelium to heme or methemoglobin renders them remarkably resistant to oxidant challenge. Endothelium defends itself from heme by induction of the heme degrading enzyme heme oxygenase and the concomitant production of large amounts of the iron binding protein ferritin.
Tárgyszavak:	Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban külföldön készült közlemény
Megjelenés:	Artificial Cells, Blood Substitutes, and Immobilization Biotechnology 22 : 2 (1994), p. 207-213. -
További szerzők:	Balla György (1953-) (csecsemő és gyermekgyógyász, neonatológus) Balla József (1959-) (belgyógyász, nephrológus) Nath, Karl Eaton, John W. Jacob, Harry S.
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