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1.
Am J Physiol Gastrointest Liver Physiol ; 318(5): G966-G979, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32308038

RESUMO

Iron overload induces intestinal-permeability defect (gut leakage), and gut translocation of organismal molecules might enhance systemic inflammation and sepsis severity in patients with thalassemia (Thal). Hence, iron administration in Hbbth3/+ mice, heterozygous ß-globin-deficient Thal mice, was explored. Oral iron administration induced more severe secondary hemochromatosis and gut leakage in Thal mice compared with wild-type (WT) mice. Gut leakage was determined by 1) FITC-dextran assay, 2) spontaneous serum elevation of endotoxin (LPS) and (1→3)-ß-d-glucan (BG), molecular structures of gut-organisms, and 3) reduction of tight-junction molecules with increased enterocyte apoptosis (activated caspase-3) by immunofluorescent staining. Iron overload also enhanced serum cytokines and increased Bacteroides spp. (gram-negative bacteria) in feces as analyzed by microbiome analysis. LPS injection in iron-overloaded Thal mice produced higher mortality and prominent cytokine responses. Additionally, stimulation with LPS plus iron in macrophage from Thal mice induced higher cytokines production with lower ß-globin gene expression compared with WT. Furthermore, possible gut leakage as determined by elevated LPS or BG (>60 pg/mL) in serum without systemic infection was demonstrated in 18 out of 41 patients with ß-thalassemia major. Finally, enhanced LPS-induced cytokine responses of mononuclear cells from these patients compared with cells from healthy volunteers were demonstrated. In conclusion, oral iron administration in Thal mice induced more severe gut leakage and increased fecal gram-negative bacteria, resulting in higher levels of endotoxemia and serum inflammatory cytokines compared with WT. Preexisting hyperinflammatory cytokines in iron-overloaded Thal enhanced susceptibility toward infection.NEW & NOTEWORTHY Although the impact of iron accumulation in several organs of patients with thalassemia is well known, the adverse effect of iron accumulation in gut is not frequently mentioned. Here, we demonstrated iron-induced gut-permeability defect, impact of organismal molecules from gut translocation of, and macrophage functional defect upon the increased sepsis susceptibility in thalassemia mice.


Assuntos
Citocinas/metabolismo , Duodeno/metabolismo , Microbioma Gastrointestinal , Hemocromatose/metabolismo , Mediadores da Inflamação/metabolismo , Ferro/metabolismo , Macrófagos/metabolismo , Sepse/metabolismo , Talassemia beta/metabolismo , Adulto , Animais , Estudos de Casos e Controles , Células Cultivadas , Modelos Animais de Doenças , Duodeno/imunologia , Duodeno/microbiologia , Feminino , Óxido de Ferro Sacarado , Hemocromatose/induzido quimicamente , Hemocromatose/imunologia , Hemocromatose/microbiologia , Heterozigoto , Humanos , Lipopolissacarídeos , Macrófagos/imunologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Permeabilidade , Sepse/induzido quimicamente , Sepse/imunologia , Sepse/microbiologia , Adulto Jovem , Globinas beta/genética , Talassemia beta/genética , Talassemia beta/imunologia , Talassemia beta/microbiologia
2.
J Biol Chem ; 291(38): 19858-72, 2016 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-27445333

RESUMO

Iron transfer across the basolateral membrane of an enterocyte into the circulation is the rate-limiting step in iron absorption and is regulated by various pathophysiological factors. Ferroportin (FPN), the only known mammalian iron exporter, transports iron from the basolateral surface of enterocytes, macrophages, and hepatocytes into the blood. Patients with genetic mutations in FPN or repeated blood transfusion develop hemochromatosis. In this study, non-mutagenic ribosomal inactivation was assessed as an etiological factor of FPN-associated hemochromatosis in enterocytes. Non-mutagenic chemical ribosomal inactivation disrupted iron homeostasis by regulating expression of the iron exporter FPN-1, leading to intracellular accumulation in enterocytes. Mechanistically, a xenobiotic insult stimulated the intracellular sentinel p38 MAPK signaling pathway, which was positively involved in FPN-1 suppression by ribosomal dysfunction. Moreover, ribosomal inactivation-induced iron accumulation in Caenorhabditis elegans as a simplified in vivo model for gut nutrition uptake was dependent on SEK-1, a p38 kinase activator, leading to suppression of FPN-1.1 expression and iron accumulation. In terms of gene regulation, ribosomal stress-activated p38 signaling down-regulated NRF2 and NF-κB, both of which were positive transcriptional regulators of FPN-1 transcription. This study provides molecular evidence for the modulation of iron bioavailability by ribosomal dysfunction as a potent etiological factor of non-mutagenic environmental hemochromatosis in the gut-to-blood axis.


Assuntos
Caenorhabditis elegans/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Hemocromatose/metabolismo , Ferro/metabolismo , Sistema de Sinalização das MAP Quinases , Ribossomos/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Transporte de Cátions/genética , Modelos Animais de Doenças , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Hemocromatose/induzido quimicamente , Hemocromatose/genética , Células Hep G2 , Humanos , MAP Quinase Quinase 4/genética , MAP Quinase Quinase 4/metabolismo , NF-kappa B/genética , NF-kappa B/metabolismo , Ribossomos/genética , Células U937 , Xenobióticos/efeitos adversos , Xenobióticos/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/genética
3.
Medicina (B Aires) ; 77(6): 458-464, 2017.
Artigo em Espanhol | MEDLINE | ID: mdl-29223935

RESUMO

Excess iron (Fe) intake in subjects carrying certain mutations in the HFE gene may result in Fe overload. To estimate risk of Fe overload, 166 male blood donors (19-65 years) from Buenos Aires city were investigated. Daily Fe intake (FeI), hem Fe intake, and Fe intake from SO4Fe enriched flours were estimated (SARA Computer Program and Food Composition Table, USDA). Serum ferritin and transferrin saturation were determined; criteria for Fe overload was serum ferritin > 300 ng/ml and transferrin saturation = 50%. HFE genotypes C282Y, H63D and S65C were analyzed by PCR-RFLP in blood samples. No participant presented FeI lower than the estimated average requirement (6 mg Fe/day) and 3.0% was over the upper level (45 mg Fe/day). Hem Fe and Fe from flour enrichment were 9.4% and 47.7% of daily Fe intake, respectively. A significant association was observed between the increase in serum ferritin (ng/ml) and the increase in FeI (p = 0.0472); 2.3% of the donors presented serum ferritin > 300 ng/ml and transferrin saturation = 50%. Genotypes associated with hereditary hemochromatosis (H63D, S65C and C282Y) were found in 29.3% of the donors. The percentage of transferrin saturation was higher in subjects carrying mutation than in wild type subjects (p = 0.0167). Although penetrance of hereditary hemochromatosis in the studied group was only 1.2%, an excessive Fe intake could enhance adverse effects in individuals unaware of any family history of Fe overload.


Assuntos
Doadores de Sangue/estatística & dados numéricos , Ferritinas/sangue , Proteína da Hemocromatose/genética , Hemocromatose/induzido quimicamente , Hemocromatose/genética , Ferro da Dieta/administração & dosagem , Adulto , Genótipo , Humanos , Ferro/sangue , Masculino , Mutação , Polimorfismo de Fragmento de Restrição , Transferrina/análise
4.
J Lipid Res ; 54(5): 1484-92, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23471031

RESUMO

Hereditary hemochromatosis (HH) is characterized by accumulation of iron, oxidative stress, inflammation, and fibrogenesis in liver tissue. In this setting, research on the protection afforded by intracellular antioxidants is of clinical relevance. Paraoxonase-1 (PON1) is an enzyme that degrades lipid peroxides. This study investigates the alterations in serum PON1 status, PON1 gene polymorphisms, and PON1 hepatic expression in patients with HH. We performed a case-control study in 77 patients with HH (80.5% men, 22-70 years of age) and 408 healthy individuals (43.1% men, 26-74 years of age). Serum PON1 activities against different substrates and PON1192 and PON155 polymorphisms were analyzed. PON1 protein expression was investigated in 20 liver biopsies. HH patients had significantly lower serum PON1 activity, which was inversely correlated with ferritin (marker of iron stores) and serum 8-isoprostane concentrations (index of oxidative stress). PON1 protein expression in liver tissue was higher in patients and showed stronger staining in hepatocytes surrounding the areas of inflammation. Our study provides preliminary evidence that PON1 may play a role in protecting against iron-induced oxidative stress in hereditary hemochromatosis.


Assuntos
Arildialquilfosfatase/sangue , Hemocromatose/genética , Fígado/enzimologia , Estresse Oxidativo , Adulto , Idoso , Arildialquilfosfatase/genética , Biópsia , Dinoprosta/análogos & derivados , Dinoprosta/metabolismo , Feminino , Ferritinas/metabolismo , Regulação da Expressão Gênica , Hemocromatose/sangue , Hemocromatose/induzido quimicamente , Humanos , Ferro/toxicidade , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Pessoa de Meia-Idade
5.
Kidney Int ; 84(4): 756-66, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23615502

RESUMO

Hepcidin, the key regulatory hormone of iron homeostasis, and iron carriers such as transferrin receptor1 (TFR1), divalent metal transporter1 (DMT1), and ferroportin (FPN) are expressed in kidney. Whether hepcidin plays an intrinsic role in the regulation of renal iron transport is unknown. Here, we analyzed the renal handling of iron in hemochromatosis Hepc(-/-) and Hjv(-/-) mouse models, as well as in phenylhydrazine (PHZ)-treated mice. We found a marked medullary iron deposition in the kidneys of Hepc(-/-) mice, and iron leak in the urine. The kidneys of Hepc(-/-) mice exhibited a concomitant decrease in TFR1 and increase in ferritin and FPN expression. Increased FPN abundance was restricted to the thick ascending limb (TAL). DMT1 protein remained unaffected despite a significant decrease of its mRNA level, suggesting that DMT1 protein is stabilized in the absence of hepcidin. Treatment of kidney sections from Hepc(-/-) mice with hepcidin decreased DMT1 protein, an effect confirmed in renal cell lines where hepcidin markedly decreased (55)Fe transport. In the kidneys of Hjv(-/-) mice exhibiting low hepcidin expression, the iron overload was similar to that in the kidneys of Hepc(-/-) mice. However, in PHZ mice, iron accumulation resulting from hemoglobin leak was detected in the proximal tubule. Thus, kidneys exhibit a tissue-specific handling of iron that depends on the extra iron source. Hepcidin may control the expression of iron transporters to prevent renal iron overload.


Assuntos
Hemocromatose/metabolismo , Hepcidinas/metabolismo , Homeostase/fisiologia , Ferro/metabolismo , Túbulos Renais Distais/metabolismo , Animais , Proteínas de Transporte de Cátions/metabolismo , Linhagem Celular , Células Cultivadas , Modelos Animais de Doenças , Proteínas Ligadas por GPI , Hemocromatose/induzido quimicamente , Hemocromatose/genética , Proteína da Hemocromatose , Hepcidinas/deficiência , Hepcidinas/genética , Técnicas In Vitro , Túbulos Renais Distais/patologia , Alça do Néfron/metabolismo , Proteínas de Membrana/deficiência , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Knockout , Gambás , Fenil-Hidrazinas/efeitos adversos , Receptores da Transferrina/metabolismo
6.
Alcohol Clin Exp Res ; 37(10): 1619-31, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23742171

RESUMO

BACKGROUND: Combined iron overload and alcohol may promote synergistic chronic liver injury and toxicity. The role of specific dietary fats in influencing the development of co-toxic alcoholic liver disease needs further evaluation and is investigated in this study. METHODS: Wild-type (WT) and the iron-loaded Hfe-null (Hfe(-/-) ) mice were fed chow (CC), a AIN-93G standard control (SC), or a corn oil-modified, AIN-93G-based (CO) diet with or without the addition of 20% ethanol (EtOH) in the drinking water for 8 weeks and assessed for liver injury. RESULTS: WT mice on CC, SC, and CO diets had no liver injury, although mild steatosis developed in the SC and CO groups. The addition of EtOH resulted in mild steatohepatitis in WT mice fed SC but not those on a CO diet. EtOH administration in Hfe(-/-) animals on the CC and SC diets caused marked oxidative stress, inflammatory activity, and subsinusoidal and portal-portal tract linkage fibrosis with significant up-regulation of genes involved in cellular stress signaling and fibrogenic pathways. These effects were abrogated in the CO-fed mice, despite elevated serum EtOH levels and hepatic iron concentrations, reduced hepatic glutathione and mitochondrial superoxide dismutase activities. Feeding with the CO diet led to increased hepatic glutathione peroxidase and catalase activities and attenuated alcohol-induced hepatic steatosis in the Hfe(-/-) animals. Iron and EtOH feeding markedly reduced p-STAT3 and p-AMPK protein levels, but this effect was significantly attenuated when a CO diet was consumed. CONCLUSIONS: A CO-based diet is protective against combined EtOH- and iron-induced liver toxicity, likely via attenuation of hepatic steatosis and oxidative stress and may have a role in the prevention of fibrosis development in chronic liver disease.


Assuntos
Óleo de Milho/administração & dosagem , Gorduras na Dieta/administração & dosagem , Modelos Animais de Doenças , Etanol/toxicidade , Hemocromatose/dietoterapia , Ferro/toxicidade , Animais , Hemocromatose/induzido quimicamente , Hemocromatose/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Distribuição Aleatória
7.
J Chemother ; 35(5): 404-410, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36322121

RESUMO

Linezolid (LZD) is an effective drug in treating multidrug-resistant tuberculosis and extensively drug-resistant tuberculosis. This study aimed to evaluate the safety of LZD in the treatment of patients with rifampicin resistant tuberculosis. This was a multicenter retrospective study. A total of 184 patients of the rifampicin resistant tuberculosis patients treated with LZD from Jan 2018 to Apr 2020 in three hospitals were involved, and their clinical symptoms were recorded and analyzed. Meanwhile, the types and incidence of adverse effects associated with LZD were evaluated. It showed that peripheral neuritis (51, 27.7%) and hemochromatosis (42, 22.8%) were the most common adverse effects observed among these patients. The median time of symptoms after LZD treatment was 45.5 and 120.0 days, respectively. Furthermore, female patients had a significantly higher risk for leukopenia (P = 0.002) and hemochromatosis (P = 0.033) when compared with male patients. History of underlying disease was the risk factor for thrombocytopenia (P = 0.022). Patients with long duration of medication (RR = 1.004, 95%CI: 1.002-1.006, P < 0.001) and daily dosage ≥600mg (RR = 3.059, 95%CI: 1.238-7.558, P = 0.015) were at higher risk of hemochromatosis. Age was the risk factor for rash (P = 0.008) and nausea and vomiting (P = 0.018). In addition, LZD administration time was the risk factor for optic neuritis (P < 0.001) and peripheral neuritis (P < 0.001). LZD can cause adverse symptoms in patients with rifampicin resistant tuberculosis. Gender, history of underlying disease, LZD use time, LZD dosage, and age are the risk factors in the LZD treatment of these patients. During medication, bone marrow suppression and neuropathy should be closely monitored. This study could potentially provide useful information for the clinical practice.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Hemocromatose , Neurite (Inflamação) , Tuberculose Resistente a Múltiplos Medicamentos , Humanos , Masculino , Feminino , Linezolida/efeitos adversos , Rifampina/efeitos adversos , Estudos Retrospectivos , Hemocromatose/induzido quimicamente , Hemocromatose/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Neurite (Inflamação)/induzido quimicamente , Neurite (Inflamação)/tratamento farmacológico , Antituberculosos/efeitos adversos
8.
J Biomed Sci ; 19: 83, 2012 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-22998440

RESUMO

BACKGROUND: Iron homeostasis is chiefly regulated by hepcidin whose expression is tightly controlled by inflammation, iron stores, and hypoxia. Hemojuvelin (HJV) is a bone morphogenetic protein co-receptor that has been identified as a main upstream regulator of hepcidin expression; HJV mutations are associated with a severe form of iron overload (Juvenile haemochromatosis). Currently however, there is no information on how HJV is regulated by inflammation. METHODS: To study the regulation of Hjv expression by inflammation and whether Hfe has a role in that regulation, control and LPS-injected wild type and Hfe KO mice were used. Moreover, human hepatoma cells (HuH7) were used to study the effect of IL-6 and TNF-α on HJV mRNA expression. RESULTS: Here we show that LPS repressed hepatic Hjv and BMPs, while it induced hepcidin 1 expression in wild-type and Hfe KO mice with no effect on hepatic pSMAD 1, 5, 8 protein levels. In addition, exogenous TNF-α (20 ng/mL) decreased HJV mRNA and protein expression to 40% of control with no effect on hepcidin mRNA expression in 24 hours. On the other hand, IL-6 induced hepcidin mRNA and protein expression with no effect on HJV mRNA expression levels. Moreover, using the HJV promoter-luciferase reporter fusion construct (HJVP1.2-luc), we showed that the basal luciferase activity of HJVP1.2-luc was inhibited by 33% following TNF-α treatment of HuH7 transfected cells suggesting that the TNF-α down-regulation is exerted at the transcriptional level. Additionally, mutation of a canonical TNF- alpha responsive element (TNFRE) within HJVP1.2-luc abolished TNF-α response suggesting that this TNFRE is functional. CONCLUSIONS: From these results, we conclude that TNF-α suppresses HJV transcription possibly via a novel TNFRE within the HJV promoter. In addition, the results suggest that the proposed link between inflammation and BMP-SMAD signalling is independent of HJV and BMP ligands.


Assuntos
Hemocromatose , Inflamação , Proteínas de Membrana , Fator de Necrose Tumoral alfa , Animais , Peptídeos Catiônicos Antimicrobianos/genética , Peptídeos Catiônicos Antimicrobianos/metabolismo , Linhagem Celular Tumoral , Proteínas Ligadas por GPI , Regulação da Expressão Gênica/efeitos dos fármacos , Hemocromatose/induzido quimicamente , Hemocromatose/genética , Hemocromatose/metabolismo , Proteína da Hemocromatose , Hepcidinas , Humanos , Inflamação/induzido quimicamente , Inflamação/genética , Inflamação/metabolismo , Interleucina-6/metabolismo , Interleucina-6/farmacologia , Ferro/metabolismo , Ligantes , Lipopolissacarídeos/toxicidade , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Knockout , Fosforilação , Regiões Promotoras Genéticas , Elementos de Resposta/genética , Proteínas Smad/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/farmacologia
9.
J Mol Med (Berl) ; 100(12): 1673-1689, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36214835

RESUMO

Alcohol-associated liver disease (ALD) is one of the most common chronic liver diseases. Its pathological spectrum includes the overlapping stages of hepatic steatosis/steatohepatitis that can progress to liver fibrosis and cirrhosis; both are risk factors for hepatocellular carcinoma. Moreover, ALD diagnosis and management pose several challenges. The early pathological stages are reversible by alcohol abstinence, but these early stages are often asymptomatic, and currently, there is no specific laboratory biomarker or diagnostic test that can confirm ALD etiology. Alcohol consumers frequently show dysregulation of iron and iron-related proteins. Examination of iron-related parameters in this group may aid in early disease diagnosis and better prognosis and management. For this, a coherent overview of the status of iron and iron-related proteins in alcohol consumers is essential. Therefore, here, we collated and reviewed the alcohol-induced alterations in iron and iron-related proteins. Reported observations include unaltered, increased, or decreased levels of hemoglobin and serum iron, increments in intestinal iron absorption (facilitated via upregulations of duodenal divalent metal transporter-1 and ferroportin), serum ferritin and carbohydrate-deficient transferrin, decrements in serum hepcidin, decreased or unaltered levels of transferrin, increased or unaltered levels of transferrin saturation, and unaltered levels of soluble transferrin receptor. Laboratory values of iron and iron-related proteins in alcohol consumers are provided for reference. The causes and mechanisms underlying these alcohol-induced alterations in iron parameters and anemia in ALD are explained. Notably, alcohol consumption by hemochromatosis (iron overload) patients worsens disease severity due to the synergistic effects of excess iron and alcohol.


Assuntos
Fígado Gorduroso , Hemocromatose , Sobrecarga de Ferro , Hepatopatias Alcoólicas , Humanos , Ferro/metabolismo , Hepcidinas , Sobrecarga de Ferro/etiologia , Sobrecarga de Ferro/metabolismo , Hemocromatose/induzido quimicamente , Hemocromatose/complicações , Hemocromatose/metabolismo , Receptores da Transferrina/metabolismo , Hepatopatias Alcoólicas/metabolismo , Fígado Gorduroso/etiologia , Etanol
10.
Environ Sci Pollut Res Int ; 25(3): 2007-2013, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27628916

RESUMO

Many environmental agents, such as excessive alcohol intake, xenobiotics, and virus, are able to damage the human body, targeting especially the liver. Metal excess may also assault the liver. Thus, chronic iron overload may cause, especially when associated with cofactors, diffuse organ damage that is a source of significant morbidity and mortality. Iron excess can be either of acquired (mostly transfusional) or of genetic origin. Hemochromatosis is the archetype of genetic iron overload diseases and represents a serious health problem. A better understanding of iron metabolism has deeply modified the hemochromatosis field which today benefits from much more efficient diagnostic and therapeutic approaches.


Assuntos
Hemocromatose/induzido quimicamente , Ferro/toxicidade , Hemocromatose/metabolismo , Humanos , Ferro/metabolismo , Sobrecarga de Ferro , Fígado/efeitos dos fármacos , Fígado/metabolismo
11.
Free Radic Biol Med ; 24(2): 239-44, 1998 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-9433898

RESUMO

Hemichrome formation resulting from oxidation of heme proteins has been proposed as sensitive indicator of iron-induced oxidative stress. The Heme Protein Spectra Analysis Program was used to quantitate oxidized heme proteins (OHP) in chronic hepatic iron overload in vivo. Rats were fed a diet containing carbonyl iron for 14 months with or without vitamin E supplementation. A 30-fold increase in hepatic iron concentration was observed in rats fed the iron-containing diet. At baseline, total OHP and TBARS were significantly elevated in iron-loaded livers but no increase in hemichrome was seen. During 3 h of spontaneous oxidation, hemichrome formation increased significantly in iron-loaded livers compared to controls. Although supplemental vitamin E was associated with lower levels of OHP and TBARS in iron-loaded livers at baseline, it did not significantly inhibit hemichrome formation during in vitro oxidation. In conclusion, an increase in hemichrome formation in iron-loaded livers was observed only during oxidation in vitro. These results suggest that total OHP is more sensitive than hemichrome formation as an indicator of oxidative stress in this in vivo model of iron overload.


Assuntos
Modelos Animais de Doenças , Hemeproteínas/metabolismo , Hemocromatose/metabolismo , Animais , Dieta , Hemocromatose/induzido quimicamente , Ferro/administração & dosagem , Ferro/metabolismo , Cinética , Fígado/metabolismo , Masculino , Oxirredução , Ratos , Ratos Sprague-Dawley , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Vitamina E/administração & dosagem , Vitamina E/sangue , Vitamina E/metabolismo
12.
Transplantation ; 65(7): 993-5, 1998 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-9565106

RESUMO

Spur cell anemia is an acquired hemolytic anemia, characterized by an increased percentage of abnormally shaped erythrocytes that are known as acanthocytes. The erythrocytes have numerous spicules irregularly distributed over the cell surface. Spur cell anemia has been described to occur in several conditions, including cirrhosis. We present an unusual case of a young patient with hemochromatosis, alcohol abuse, decompensated cirrhosis, and spur cell anemia who had a spontaneous resolution of the spur cell anemia after orthotopic liver transplantation. This finding suggests that the diseased liver may contribute to transformation of the erythrocyte to the spur cell.


Assuntos
Anemia Hemolítica/terapia , Transplante de Fígado , Adulto , Anemia Hemolítica/sangue , Anemia Hemolítica/complicações , Hemocromatose/sangue , Hemocromatose/induzido quimicamente , Humanos , Hepatopatias/sangue , Hepatopatias/complicações , Masculino
13.
Biochem Pharmacol ; 44(6): 1023-7, 1992 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-1417929

RESUMO

The oral efficacy of the oral iron chelators 1,2-dimethyl-3-hydroxypyrid-4-one (CP20), 1,2-diethyl-3-hydroxypyrid-4-one (CP94) and desferrioxamine B (DFO) has been compared with intraperitoneal DFO in an experimental model of iron overload with similar biochemical and biophysical characteristics to those observed for human genetic haemochromatosis. The hepatic iron stores in the ferrocene-loaded rat were relatively stable and did not decrease at the end of the loading period. In contrast, the iron dextran rat model showed a rapid depletion of its iron stores 2 weeks after cessation of intraperitoneal injection. When CP20 and CP94 were administered to the ferrocene-loaded rat model in combination with an iron-free diet there were significant decreases in (i) total homogenate iron and (ii) hepatic ferritin iron when compared to the iron-loaded rat receiving the iron-free diet alone. Desferrioxamine, when administered by gavage, only showed chelation of ferritin iron, while intraperitoneal injection of desferrioxamine showed significant depletion of iron both in the total homogenate and ferritin. Subcellular fractionation of the hepatic organelle clearly showed that where there was depletion of homogenate iron there was a net decrease in the lysosomal fraction, while changes in ferritin iron were reflected by decreases in the cytosolic iron content. Although no assessment of net iron excretion was made, we suggest that the use of this animal model should ascertain the site of chelation by iron chelators.


Assuntos
Compostos Ferrosos , Quelantes de Ferro/farmacologia , Ferro/metabolismo , Compostos Organometálicos , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Deferiprona , Desferroxamina/farmacologia , Modelos Animais de Doenças , Coração/efeitos dos fármacos , Hemocromatose/induzido quimicamente , Hemocromatose/prevenção & controle , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Metalocenos , Piridonas/farmacologia , Ratos , Ratos Wistar , Baço/efeitos dos fármacos , Baço/metabolismo , Frações Subcelulares/metabolismo
14.
Invest Radiol ; 20(3): 267-71, 1985.
Artigo em Inglês | MEDLINE | ID: mdl-4030264

RESUMO

Hepatocellular neoplasms, including neoplastic nodules (NN), are the most commonly induced tumors resulting from chemical carcinogen evaluation. Our objective was to image neoplastic nodules using computed tomography. In a preliminary study using rats with diethylnitrosamine (DEN) induced tumors, lesions smaller than 1.5 cm were difficult to identify by CT. Since NN do not take up excess iron whereas normal liver does accumulate iron, we studied iron as a CT contrast material. Hemochromatosis was induced in 15 control rats by subcutaneous injections of iron dextran. A linear increase in iron-loading dose produces a linear CT liver enhancement (r = 0.97): 68, 80, 84, 94, and 104 HU at 0, one, two, four, and six weeks, respectively. No loss of enhancement was noted ten weeks later. Rat hepatic tissue was chemically analyzed after a similar iron-loading regimen. The iron concentration (microgram/g hepatic tissue) progressively increased during the first four weeks of loading and remained stable for three weeks following iron-loading. Four animals that had been given DEN and iron were examined by CT scanning to detect small NN. Iron-enhanced CT allowed the visualization of small lesions (less than 5 mm). Histopathologic sections confirmed a homogeneous pattern of iron uptake in normal liver with a deficiency of iron in NN. We conclude that CT scanning following iron-loading is a noninvasive method to detect small nodules and may provide a method to study the progression or regression of small liver nodules in rodents.


Assuntos
Dietilnitrosamina/toxicidade , Neoplasias Hepáticas Experimentais/diagnóstico por imagem , Nitrosaminas/toxicidade , Tomografia Computadorizada por Raios X/métodos , Animais , Hemocromatose/induzido quimicamente , Complexo Ferro-Dextran/administração & dosagem , Complexo Ferro-Dextran/toxicidade , Neoplasias Hepáticas Experimentais/induzido quimicamente , Masculino , Intensificação de Imagem Radiográfica/métodos , Ratos , Ratos Endogâmicos F344 , Fatores de Tempo
15.
Ann N Y Acad Sci ; 526: 290-300, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-3164602

RESUMO

The gene coding for idiopathic hemochromatosis is prevalent in Sweden, the country with the highest iron fortification of food (42%) in the world. We wanted to study if this highly iron-fortified diet had negative effects on the iron situation in carriers of the iron-loading genes. Iron stores averaged 6.7 grams in male homozygotes who were mainly identified through laboratory screening. It was 3.4 grams in female homozygotes. By HLA typing of family members of these homozygous probands, 39 additional homozygotes and 172 heterozygotes were detected. Serum ferritin averaged 620 micrograms/l in 20 male and 168 micrograms/l in 19 female homozygotes in the family screening. Storage iron as measured by serum ferritin concentration was slightly but significantly higher in male heterozygotes than controls (117 micrograms/l versus 87 micrograms/l, p less than 0.02). There was no further increase in serum ferritin concentration with age after 40 years. Heterozygotes showed no clinical signs of iron damage. These findings do not indicate that carriers of the iron-loading genes in Sweden have been adversely affected by the highly iron-fortified diet of the country.


Assuntos
Alimentos Fortificados/efeitos adversos , Hemocromatose/induzido quimicamente , Ferro/efeitos adversos , Administração Oral , Adolescente , Adulto , Biópsia por Agulha , Desferroxamina , Dieta , Feminino , Ferritinas/sangue , Marcadores Genéticos , Antígenos HLA/análise , Hemocromatose/diagnóstico , Hemocromatose/genética , Humanos , Ferro/administração & dosagem , Ferro/análise , Fígado/patologia , Masculino , Fatores Sexuais
16.
Nutrition ; 20(7-8): 615-9, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15212743

RESUMO

Although it generally does not improve performance, iron is often used by elite athletes. The physiologic changes induced by exercise can mimic iron deficiency and decrease hemoglobin and ferritin concentrations. Determination of serum transferrin receptor concentrations may identify true iron deficiency, which occurs particularly in young athletes. In contrast, increased iron stores in the body are a frequent finding in elite athletes who have used long-term iron supplementation. Elite runners have increased intestinal blood loss, but this usually can be compensated by enhanced absorption of dietary iron. The combination of exercise-induced hemolysis with enhanced intestinal blood loss in various endurance sports leads to severe abnormalities of routine tests, and extreme physical activity may be responsible for positive fecal occult blood determinations. Indiscriminate iron supplementation carries the risk of inducing hemochromatosis in individuals homozygous for the widespread C282Y allele of the HFE gene. This polymorphism is common and can be found in about 1% of individuals of Northern European descent; moreover, iron supplementation can modify the presentation of important underlying diseases such as celiac disease or colon carcinoma. In conclusion, iron supplements should be prescribed for athletes with iron-deficiency anemia and carefully monitored if given for prophylaxis; unless a therapeutic response occurs, investigations to establish the cause of iron deficiency should be initiated.


Assuntos
Ferro da Dieta/administração & dosagem , Esportes/fisiologia , Adaptação Fisiológica , Suplementos Nutricionais , Exercício Físico/fisiologia , Ferritinas/sangue , Hemocromatose/induzido quimicamente , Hemoglobinas/análise , Humanos , Absorção Intestinal , Deficiências de Ferro , Ferro da Dieta/efeitos adversos , Ferro da Dieta/farmacocinética , Fatores de Risco
17.
Pathol Res Pract ; 196(1): 47-54, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10674272

RESUMO

The purpose of this study was to estimate the iron concentration in the liver, spleen and brain of control rats and rats overloaded with iron and to determine the distribution of iron and of transferrin (TF). Iron was administered to Wistar rats by food supplemented with 3% carbonyl iron for 3 months, or intraperitoneally, or intraveneously as iron polymaltose for 4 months (total administered dose: 300 or 350 mg/rat, respectively). Iron concentration was estimated by atomic absorption spectrophotometry and iron- and TF-distribution histochemically and immunohistochemically, respectively. In control rats the organ with the highest iron content was the spleen, followed by the liver and brain. After iron loading the increase of iron in the liver was greater than that of the spleen; iron concentration in the brain did not change significantly. Distribution of iron in the liver was in Kupffer cells throughout the lobule and in hepatocytes at its periphery. No difference in the number of positive cells or staining intensity for TF was observed between control rats and iron overloaded animals in the liver or central nervous system (CNS); the spleen was negative for TF. Distribution of TF in the liver showed a centrilobular localisation in hepatocytes. TF reaction in the brain occurred in oligodendrocytes, vessel walls, choroid plexus epithelial cells and some neurons. In conclusion, experimental iron overload in rats leads to iron uptake mainly by reticuloendothelial (RE) cells and hepatocytes, indicating that hepatocytes are of particular importance for iron metabolism. Iron uptake by the brain was not significant, probably because the brain is protected against iron overload. Iron overload did not influence location and quantity of TF in the liver and CNS, whereas the visualisation of iron and TF did not coincide. This indicates that TF may have other functions beyond iron transport.


Assuntos
Sistema Nervoso Central/metabolismo , Hemocromatose/metabolismo , Ferro/metabolismo , Fígado/metabolismo , Baço/metabolismo , Transferrina/metabolismo , Animais , Sistema Nervoso Central/patologia , Hemocromatose/induzido quimicamente , Hemocromatose/patologia , Técnicas Imunoenzimáticas , Ferro da Dieta/administração & dosagem , Células de Kupffer/metabolismo , Células de Kupffer/patologia , Fígado/patologia , Masculino , Ratos , Ratos Wistar , Baço/patologia
18.
Gematol Transfuziol ; 37(9-10): 25-8, 1992.
Artigo em Russo | MEDLINE | ID: mdl-1490567

RESUMO

Summation of negative effects of hypoxia and lysosome-tropic properties of Ferrum Lec was observed in patients with severe stage of iron-deficiency anemia (IDA), and in rabbits with experimental IDA, during treatment by intravenous injections of Ferrum Lec. These effects were expressed in exageration of the destabilizing action of hypoxia on lysosome membranes, and attended by a significant rise in the lysosomal enzyme levels of blood plasma, by the development of dystrophic processes in hepatocytes, and by a decrease in the number of sinusoidal cells. All these facts should be considered in clinical practice.


Assuntos
Anemia Hipocrômica/tratamento farmacológico , Hemocromatose/induzido quimicamente , Hipóxia/induzido quimicamente , Compostos Organometálicos/efeitos adversos , Polissacarídeos/efeitos adversos , Animais , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Avaliação de Medicamentos , Avaliação Pré-Clínica de Medicamentos , Hemocromatose/prevenção & controle , Humanos , Hipóxia/prevenção & controle , Injeções Intravenosas , Compostos Organometálicos/administração & dosagem , Polissacarídeos/administração & dosagem , Coelhos
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