Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The biochemical diversity of the various porphyris often leads to incomplete investigation of photosensitive patients and porphyria may be excluded wrongly on the basis of normal urinary porphyrins alone. Establishing a biochemical referral centre for photosensitive patients suspected of having porphyria led to the diagnosis of 5 cases of porphyria cutanea tarda (PCT) and 2 cases of erythropoietic protoporphyria (EPP) among 34 patients referred by dermatologists over a period of 12 months. Iron overload was conformed in 3 the PCT patients by plasma ferritin assay. Studies on the available families of the two EPP patients revealed elevated red cell protoporphyrin levels in several clinically asymptomatic relatives.
 ...
PMID:The detection of porphyria in photosensitive patients. 64 17

Porphyria cutanea tarda (PCT) and experimental porphyria are characterized by a decreased activity of the enzyme uroporphyrinogen decarboxylase, and accumulation of uroporphyrins and heptacarboxylporphyrins in the liver. Iron (Fe) plays an important role in PCT and experimental porphyria. Biochemically and electron microscopically, we examined the relationship between Fe and porphyrins in liver tissue of C57BL/10 mice made porphyric by administration of iron dextran as Imferon (IMF), and in liver biopsies of patients with symptomatic PCT. Accumulation of uroporphyrins and heptacarboxylporphyrins, and an increased amount of Fe were observed in livers of mice treated with IMF and in liver biopsies of patients with PCT. In mice treated with IMF, the activity of uroporphyrinogen decarboxylase was decreased. Both in livers of mice treated with IMF and in livers of patients with PCT, needle-like structures, representing uroporphyrin crystals, were observed by electron microscopy. Uroporphyrin crystals and Fe (as ferritin) were observed in the same hepatocyte. Moreover, there was a striking morphological correlation between uroporphyrin crystals and ferritin-Fe, suggesting a role for (ferritin-)Fe in the pathogenesis of porphyria.
 ...
PMID:The role of iron in experimental porphyria and porphyria cutanea tarda. 138 28

The possibility of a metabolic chronic liver disease must always be borne in mind since in certain cases treatment can prevent the lesions from getting worse. The clinical and biochemical context should suggest either (1) genetic haemochromatosis when faced with high serum iron and ferritin levels and elevated transferrin saturation or with a suggestive clinical context (melanoderma, diabetes, hypogonadism, arthropathy, myocardiopathy); or (2) Wilson's disease in young subjects, especially in the presence of neurological and ocular signs or of haemolytic anaemia; or (3) porphyria in case of cutaneous manifestations caused by exposure to sun light. Hence the importance of full clinical examination in patients with chronic liver disease.
 ...
PMID:[Metabolic cirrhosis (hemochromatosis, Wilson's disease, erythropoietic protoporphyria)]. 206 17

A desferrioxamine (DFO) infusion test, using a DFO dose of 36.9 +/- 11.2 mg/kg (mean +/- SD), was performed in 50 consecutive dialysis patients undergoing diagnostic bone biopsy. In 30 patients whose bones stained positively for aluminium the serum aluminium level increased by an average of 373 +/- 250.4 ng/ml. The increase in 20 aluminium-negative patients was 231 +/- 179.2 ng/ml (p less than 0.05). Aluminium-positive patients had lower levels of immunoreactive parathyroid hormone (336 +/- 442 muleq/ml) than aluminium-negative patients (1278 +/- 1400 muleq/ml; p less than 0.05). A change in serum aluminium level of greater than 200 ng/ml after the administration of DFO was 73 percent sensitive and 50 percent specific, and had a positive predictive value of 69 percent for detecting positive bone aluminium staining. The combination of a baseline immunoreactive parathyroid hormone level less than 200 muleq/ml and a change in serum aluminium of greater than 200 ng/ml after DFO was 90 percent specific and had a positive predictive value of 85 percent. In the second phase of our study, 28 dialysis patients with aluminium toxicity received long-term therapy (11.0 +/- 4.3 months) with DFO at an average starting dose of 41.7 +/- 17.1 mg/kg, administered once weekly. The four deaths which occurred during this treatment involved the only patients who had advanced dialysis dementia. Seven patients with less severe neurological symptoms responded favourably. Fractures decreased from 1.7 fractures/patient/year to 0.1 fracture/patient/year. Muscular strength and overall functional class were improved or stable in 25 patients; myalgias and arthralgias were also stable or improved in 19 patients. After 5-7 months of treatment, serum aluminium levels decreased from 401 +/- 262 ng/ml to 245 +/- 217 ng/ml (p less than 0.01); erythrocyte mean corpuscular volume increased from 86.3 +/- 10.91 fl to 94.1 +/- 9.23 fl (p less than 0.02); and serum calcium decreased from 10.4 +/- 0.94 mg/dl to 9.9 +/- 0.70 mg/dl (p less than 0.02). Serum immunoreactive parathyroid hormone levels remained stable in 25 patients, but severe hyperparathyroidism developed rapidly in three patients. Eight patients with transfusional iron overload had no change in serum ferritin levels. Iron depletion developed in six patients, with a decrease in serum ferritin from 251 +/- 229.8 micrograms/l to 45 +/- 29.3 micrograms/l, and they required parenteral iron supplementation. Significant side-effects occurring during long-term DFO administration were hypotension (11 patients), gastrointestinal upset (seven patients), porphyria cutaneous tarda-like lesions (three patients), and transient visual disturbance (one patient). There was a decrease in stainable bone aluminium in all nine patients with paired bone biopsy specimens (pre- and post-DFO).(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Clinical experience with desferrioxamine in dialysis patients with aluminium toxicity. 211 95

Studies were carried out to elucidate if in the hexachlorobenzene (HCB) porphyria, total, nonhaem and haem iron contents in liver are altered and if any relation exists between these alterations and the hepatic porphyrinogen carboxy-lyase (PCL) decrease in rats treated with the drug. It was observed that in porphyric livers total and non-haem iron levels increased significantly as a consequence of HCB intoxication while this treatment produced a non significant decrease in the haem iron content. Enzymic preparations of porphyric livers filtered through Sephadex G-25 columns which separate the free iron and that has a content of iron-protein greater than those in normals, exhibited a strong inhibition of PCL. Chelating agents, alpha' alpha' bipyridyl and 8-hydroxyquinoline do not revert such inhibition. The effect in vitro of ferritin, haemin and inorganic iron at different concentrations on normal PCL activity was also assayed. So, it could be observed that inorganic iron and haemin produce slight inhibition of PCL when added in concentrations higher than those corresponding to a porphyric liver (0.08 mM and 10(-6) M, respectively, as mean in the incubation media). So, they have not physiological significance. Ferritin does not modify the decarboxylation process. From these results it arises that iron does not play a direct role in the decrease of PCL activity in the experimental porphyria by HCB, not being the inhibitor made evident by heating assays. Iron could perhaps stimulate the metabolization of HCB, giving rise to active metabolite.
 ...
PMID:The role of iron in the hexachlorobenzene induced porphyria. I. Studies on different types of iron and its relation with porphyrinogen carboxy-lyase decrease. 294 Aug 9

This study was designed to determine whether iron contents are altered in hexachlorobenzene (HCB)-induced porphyria, and whether there is any relation between these alterations and the effects of the drug on several enzymes of the haem pathway. To this end, the effect of HCB administration on total, non-haem and haem iron levels was studied. Further, the effects of the addition of: both heated and non-heated HCB-porphyric liver preparations, iron as sulfate, ferritin and haemin and alpha alpha'-bipyridyl and 8-hydroxyquinoline were studied on the following enzymes: delta-aminolaevulinic acid synthase, delta-aminolaevulinic acid dehydratase, porphobilinogenase and porphyrinogen carboxy-lyase. Total and non-haem iron levels increased significantly as a result of HCB intoxication, but there was a non-significant decrease in haem iron content. The increased iron levels did not appear to be directly involved in the increased activities of delta-aminolaevulinic acid synthase and delta-aminolaevulinic acid dehydratase observed in HCB-induced porphyria, since it was not possible to detect any activation in heating and crossed assays nor by the addition of inorganic iron, protein-iron or haemin. Results from heating and crossed assays suggested the existence of an activator for porphobilinogenase and an inhibitor for porphyrinogen carboxy-lyase, while results obtained with chelating agents suggested that iron could partly account for the activation of porphobilinogenase. Iron was not directly involved with the decreased activity of porphyrinogen carboxy-lyase, since neither iron chelators nor different types of iron produced physiologically significant effects.
 ...
PMID:Studies on the role of iron in the alterations observed in hexachlorobenzene-induced porphyria. 359 48

Serum ferritin, an index of iron stores, was studied in 60 patients with porphyria cutanea tarda (PCT), in 21 patients who had other liver diseases without siderosis (cirrhosis [LC] and chronic active hepatitis [CAH]), and in 32 patients with associated liver siderosis (alcoholic LC, LC and CAH in minor thalassemia). Ferritin levels were higher in patients with porphyria than in healthy controls and patients without liver siderosis (P less than 0.001), whereas no statistical difference was observed between patients with porphyria and those with liver siderosis. Because iron removal is considered the treatment of choice for PCT, some patients with PCT underwent phlebotomy and others received chelating therapy with subcutaneous infusion of deferoxamine. Follow-up of the patients showed a correlation between serum ferritin level and urinary porphyrin excretion; when the clinical and biochemical syndrome became normal, serum iron and ferritin had fallen to normal values (t test pair data analysis before and after: P less than 0.001 in each group). No appreciable difference was found between controls and patients with PCT whose conditions had been normalized, irrespective of the chronic liver damage always present in PCT. Our results suggest that serum ferritin increase in PCT is related more to liver iron overload than to liver damage, and ferritin follow-up is recommended to indicate the exhaustion of hepatic iron stores during iron depletion therapy, as well as to detect an early replenishment after remission.
 ...
PMID:Serum ferritin in the assessment of liver iron overload and iron removal therapy in porphyria cutanea tarda. 394 Dec 93

Some parameters of iron metabolism in 26 patients with porphyria cutanea tarda (PCT) which is often associated with mild iron overload and hepatic siderosis, are studied. Serum iron, percent transferrin saturation and ferritin were pathologically increased. Statistical comparisons were performed between PCT patients and healthy controls, liver disease patients (cirrhosis, chronic active hepatitis) and patients with associated liver siderosis (alcoholic cirrhosis, cirrhosis and chronic active hepatitis in thalassemia). Ferritin levels are higher in patients with porphyria than in healthy controls (p less than 0,001) and in patients without liver siderosis (p less than 0,001). No statistical difference is observed between patients with porphyria and patients with siderosis. A significant decrease in ferritin levels is registered after venesection therapy. The conclusion is drawn that serum ferritin increase in PCT is related to hepatic iron store amounts rather than hepatic necrosis. It is assumed that ferritin follow-up during phlebotomy therapy and also during remission is useful to indicate the exhaustion or an early replenishment of hepatic iron stores.
 ...
PMID:[Determination of serum ferritin in porphyria cutanea tarda. A reliable sign of hepatic siderosis]. 670 23

Many patients with porphyria cutanea tarda (PCT) have been reported to be hepatitis C virus (HCV) carriers, suggesting that HCV infection plays a role in the pathogenesis of this type of porphyria. In this study, we report a patient with chronic hepatitis C-associated PCT. Therapy with interferon (IFN) transiently decreased HCV RNA levels, but levels of urinary porphyrins and serum transaminases and ferritin remained unchanged. Serum ferritin and urinary porphyrin levels improved after phlebotomy, but this therapy was not effective in improving serum transaminase levels. Although a physiopathological association between HCV infection and PCT has been suggested previously, IFN was not effective in this patient. The transient decrease in HCV RNA levels was a factor independent of porphyrin metabolism.
 ...
PMID:Ineffective interferon treatment of chronic hepatitis C-associated porphyria cutanea tarda, but with a transient decrease in HCV RNA levels. 1063 44

5-Aminolevulinic acid (ALA), a heme precursor that accumulates in acute intermittent porphyria (AIP) and lead poisoning, undergoes enolization and subsequent iron-catalyzed oxidation at neutral pH. Iron is released from horse spleen ferritin (HoSF) by both ALA-generated O(2)(.-) and enoyl radical (ALA(z.rad)), which amplifies the chain of ALA oxidation (autocatalysis). Iron chelators such as EDTA, ATP, but not citrate, and phosphate accelerate this process and ALA-promoted iron release from HoSF is faster in horse spleen isoferritins containing larger amounts of phosphate in the core. ALA (+0.377 V versus standard hydrogen electrode) is less effective in releasing iron from ferritin than are thioglycollic acid, 6-hydroxydopamine, and N,N,N', N'-tetramethyl-p-phenylenediamine. During electrochemical one electron oxidation of ALA in a nitrogen atmosphere, spin trapping experiments with 3,5-dibromo-4-nitrosobenzenesulfonic acid demonstrated the formation of a spin adduct characterized by a six line signal, indicating a secondary carbon-centered radical and attributed to a resonant ALA&z.rad; radical. Iron is also released in such anaerobic electrochemical oxidations of ALA in the presence of ferritin, suggesting that, in addition to O(2)(*-), ALA&z.rad; can promote iron mobilization from ferritin. Hence, ALA&z.rad; may amplify the metal-catalyzed oxidation of ALA, damaging ALA-accumulating cells and possibly contributing to the symptoms of porphyria.
 ...
PMID:Roles of phosphate and an enoyl radical in ferritin iron mobilization by 5-aminolevulinic acid. 1111 17


1 2 Next >>