Pulmonary Dysfunction in Transfusion-Dependent Thalassemia and Response to Intensive Chelation Therapy

Objectives: To evaluate pulmonary functions in children with transfusion-dependent thalassemia, and its reversal (lung dysfunction) using intensive intravenous chelation with desferrioxamine (DFO) (4 weeks). Methods: This descriptive study enrolled 77 children with transfusion-dependent thalassemia. Pulmonary function test (PFT) and iron load (serum ferritin (SF) & T2* MRI of heart and liver) were done. PFT included spirometry, total lung capacity (TLC) by helium dilution test and diffusion capacity by carbon monoxide (DLCO). Follow-up PFT was available for 13 children with moderate to severe lung dysfunction given intravenous DFO. Results: 50 (68.8%) patients had lung dysfunction, most commonly diffusional impairment (48; 96%), and reduced TLC (11; 22%); and none had obstructive pattern. 9 (81.8%) patients with restrictive defect had moderate to severely deranged DLCO. PFT and T2* MRI values were inversely correlated with serum ferritin. Among 13 patients receiving intensive chelation for 4 weeks, significant improvement was noticed in forced expiratory volume in one minute/ forced vital capacity ratio (?FEV1/FVC) (P=0.009), ?DLCO (P=0.006) and ?SF (P=0.01). Conclusions: Pulmonary dysfunction is common in children with multi-transfused thalassemia, and routine screening by PFT needs to be part of the management guidelines.

Prospecção de sideróforos do tipo hidroxamato e quinona para terapia de sobrecarga de ferro / Prospection of hydroxamate and quinone-type siderophores for iron overload chelation therapy

A sobrecarga de ferro é uma condição prejudicial para os pacientes, que apresentam uma diminuição significativa na qualidade de vida. Os fármacos quelantes são moléculas que têm capacidade de uso clínico para atuar como atenuadores da sobrecarga de metais. Neste trabalho apresentamos uma análise de sideróforos do tipo hidroxamato e quinona, com o objetivo de ampliar a gama de terapia de sobrecarga de ferro. Para cada composto foi realizado um ensaio competitivo com a sonda calce- ína para verificar a capacidade de ligação do ferro, e um ensaio antioxidante baseado na supressão da oxidação dependente de ferro da dihidrorrodamina (DHR) sob ascorbato. Foi observado que o hidroxamato cíclico piridoxatina apresentou capacidade de sequestrar ferro de substratos de alta afinidade, tanto em meio tamponado quanto em meio intracelular. Em ambas as situações também se mostrou um antioxidante eficiente. Entretanto, parece ser o mais tóxico do grupo dos hidroxamatos (que ainda continha o hidroxamato linear desferricoprogênio e o aromático desferriastercromo). Outros compostos naturais também foram estudados como possíveis candidatos a fármacos para sobrecarga de ferro. Complexos de ferro foram caracterizados por espectrofotometria para avaliar a estequiometria possível, considerando os sítios de ligação para cada composto. Ensaios de fluorescência revelaram que entre os quatro compostos em estudo (ácido clorogênico, lapachol, hemateína e hematoxilina), o complexo entre ferro e hemateína apresenta maior estabilidade relativa do que outros

Iron overload is a harmful condition for patients, who have a significant decrease in life quality. Chelating drugs are molecules that have the capacity for clinical use to act as attenuators of metal overload. In this work we present an analysis of hydroxamate and quinone-type siderophores, intending to broaden the range of iron overload therapy. For each compound it was conducted a competitive assay with the fluorescent probe calcein to verify the iron binding ability, and an antioxidant assay based on suppression of the iron-dependent oxidation of dihydrorhodamine (DHR) under ascorbate. It was observed that cyclic hydroxamate pyridoxatin displayed good ability to scavenge iron from high affinity substrates both in buffer and in intracellular medium. It was also an efficient antioxidant in both setups. However, pyridoxatin seems to be the most toxic from the hydroxamate group (composed also by the linear desferricoprogen and the aromatic desferriasterchrome). Other natural compounds have also been studied as possible candidates for iron-overload drug therapy. Iron complexes were characterized by spectrophotometry to assess the possible stoichiometry considering the binding sites for each compound. Fluorescence assays revealed that among the four compounds in study (chlorogenic acid, lapachol, hematein and hematoxylin), the complex between iron and hematein has higher relative stability than others

Experimental study on the effect of desferrioxamine on targeted homing and angiogenesis of bone marrow mesenchymal stem cells / 中国修复重建外科杂志

Objective: To investigate whether desferrioxamine (DFO) can enhance the homing of bone marrow mesenchymal stem cells (BMSCs) and improve neovascularization in random flaps of rats. Methods: BMSCs and fibroblasts (FB) of luciferase transgenic Lewis rats were isolated and cultured. Forty 4-week-old Lewis male rats were used to form a 10 cm×3 cm rectangular flap on their back. The experimental animals were randomly divided into 4 groups with 10 rats in each group: in group A, 200 μL PBS were injected through retrobulbar venous plexus; in group B, 200 μL FB with a concentration of 1×10 6 cells/mL were injected; in group C, 200 μL BMSCs with a concentration of 1×10 6 cells/mL were injected; in group D, cells transplantation was the same as that in group C, after cells transplantation, DFO [100 mg/(kg·d)] were injected intraperitoneally for 7 days. On the 7th day after operation, the survival rate of flaps in each group was observed and calculated; the blood perfusion was observed by laser speckle imaging. Bioluminescence imaging was used to detect the distribution of transplanted cells in rats at 30 minutes and 1, 4, 7, and 14 days after operation. Immunofluorescence staining was performed at 7 days after operation to observe CD31 staining and count capillary density under 200-fold visual field and to detect the expressions of stromal cell derived factor 1 (SDF-1), epidermal growth factor (EGF), fibroblast growth factor (FGF), and Ki67. Transplanted BMSCs were labeled with luciferase antibody and observed by immunofluorescence staining whether they participated in the repair of injured tissues. Results: The necrosis boundary of ischemic flaps in each group was clear at 7 days after operation. The survival rate of flaps in groups C and D was significantly higher than that in groups A and B, and in group D than in group C ( P<0.05). Laser speckle imaging showed that the blood perfusion units of flaps in groups C and D was significantly higher than that in groups A and B, and in group D than in group C ( P<0.05). Bioluminescence imaging showed that BMSCs gradually migrated to the ischemia and hypoxia area and eventually distributed to the ischemic tissues. The photon signal of group D was significantly stronger than that of other groups at 14 days after operation ( P<0.05). CD31 immunofluorescence staining showed that capillary density in groups C and D was significantly higher than that in groups A and B, and in group D than in group C ( P<0.05). The expressions of SDF-1, EGF, FGF, and Ki67 in groups C and D were significantly stronger than those in groups A and B, and in group D than in group C. Luciferase-labeled BMSCs were expressed in the elastic layer of arteries, capillaries, and hair follicles at 7 days after transplantation. Conclusion: DFO can enhance the migration and homing of BMSCs to the hypoxic area of random flap, accelerate the differentiation of BMSCs in ischemic tissue, and improve the neovascularization of ischemic tissue.

Hypoxia Enhances Osteogenic Differentiation in Retinoic Acid-Treated Murine-Induced Pluripotent Stem Cells

Hypoxic condition influences biological responses in various cell types. However, a hypoxic regulating osteogenic differentiation remains controversy. Here, an influence of short-term culture in hypoxic condition on osteogenic marker gene expression by retinoic acid-treated murine gingival fibroblast-derived induced pluripotent stem cells (RA-miPS) was investigated. Results demonstrated that hypoxic condition significantly upregulated Vegf, Runx2, Osx, and Ocn mRNA expression by RA-miPS in normal culture medium at day 3. Further, desferrioxamine significantly downregulated pluripotent marker (Nanog and Oct4) and enhanced osteogenic marker (Runx2, Osx, Dlx5, and Ocn) gene expression as well as promoted in vitro mineral deposition. However, the effect of cobalt chloride on osteogenic differentiation of RA-miPS was not robust. In summary, the results imply that hypoxic condition may be useful in the enhancement of osteogenic differentiation in RA-miPS.

Effect of iron chelator desferrioxamine on serum zinc levels in patients with beta thalassemia major

β-thalassemia is the most common genetic disorder worldwide with an increased prevalence around the Mediterranean, Indian subcontinent and in South-East Asia. Various siderotic and non-siderotic complications significantly impact the quality of life. Thalassemic patients are also at risk of zinc deficiency due to diverse causes including desferrioxamine chelation. This study sought to investigate the prevalence of zinc deficiency in beta thalassemia major patients on desferrioxamine for iron chelation. Study design: This was a descriptive, prospective, cross-sectional study over a 6-month period. 63 cases of beta thalassemia major within the age group of 5-15 years on desferrioxamine for at least 1 year, were included. Basic patient demographics such as age, gender and duration of disease were recorded. Serum zinc levels were determined by atomic absorption spectrophotometry. Results: The mean age of patients was 10.84±3.47 (5 to 15) years. There were 35 (55.6%) males and 28(44.4%) females. The prevalence of zinc deficiency (zinc levels < 50 μg / dl) was 22.2%. Proportions of deficiency were higher in males with a duration of disease beyond 10 years. Conclusions: Zinc deficiency is not uncommon in beta thalassemia patients on desferrioxamine. We suggest that zinc levels be regularly monitored in these patients.

Iron-Chelating Property of Phytic Acid in Thalassaemia: An In vitro Study.

Aims: The aim of this study is to report an oral iron chelator phytic acid (PA), on blood samples from different types of thalassaemic patients of various age groups and physical conditions. Study Design: The In vitro iron chelating effect was evaluated by ferritin assay using ELISA. Methodology: Blood from the iron-overloaded 30 Thalassaemic patients of different age groups, body weights and heights were collected and the serum was separated. Patients without any history of blood transfusion and chelation therapy were taken as control group. The ELISA based ferritin assay was performed with standard phytic acid (40% water solution, Fluka), using Desferrioxamine (DFO) as control (0.5g Deferoxamine mesylate USP, Novartis, USA). The serum ferritin levels were recorded in two different conditions (treated with DFO and PA) at different time intervals (10, 30 and 60 min) by measuring absorbance at 450 nm. Results: The Kolmogorov-Smirnov test of patient samples in two different conditions showed that the ferritin concentration, treated by DFO and PA, was significantly decrease in PA treated group compared to DFO, when used in equivalent concentrations, at intervals of 10 min (P=0.760),30 min (P=0.537) and 60 min (P=0.055). Conclusion: The common iron chelators DFO or Deferiprone used as monotherapy may lead to transient and incomplete removal of iron, while PA showed a more complete and sustained removal of ferritin due to specific chemical binding at a wider pH range. However, further trial is required to establish its maintenance dose, comparative efficacy and mechanism of action.

An anti-fibrosis mechanism study on effects of difference in iron load levels on activation and apoptosis of hepatic stellate cells / 中国中西医结合急救杂志

Objective To investigate the anti-fibrosis mechanism from effects of difference in iron load levels on activation and apoptosis of hepatic stellate cells(HSCs). Methods According to the difference in iron load levels in HSCs,HSC-T6 cells were divided into four groups:blank control,iron deposition model,50μmol/L desferrioxamine and 25 μmol/L desferrioxamine groups. Quantitative polymerase chain reaction(PCR)was applied for the detection of collagen type Ⅰ and transforming growth factor-β1(TGF-β1)mRNA expressions of HSC-T6 cells. Immunohistochemical assay was used for the detection of α-smooth muscle actin(α-SMA)expression. The method of terminal deoxynucleotidyl transferase(TdT)-mediated dUTP nick end labeling(TUNEL)was used for the examination of apoptosis of HSC-T6 cells. Under electron microscope,the ultrastructures of HSC-T6 cells were observed. Results Compared with the blank control group,despite the TGF-β1 mRNA expression in iron deposition model group was increased,no statistical significant difference was seen(1.594±0.168 vs. 1.477±0.126, P>0.05),whereas collagen type I mRNA expression was significantly enhanced(1.354±0.076 vs. 1.197±0.104, P<0.01). Both 50μmol/L and 25μmol/L desferrioxamine could down-regulate collagen type I and TGF-β1 mRNA expressions,and the action of 50μmol/L desferrioxamine was superior to that of 25μmol/L desferrioxamine(collagen typeⅠmRNA:0.391±0.076 vs. 0.688±0.060,TGF-β1 mRNA:0.421±0.068 vs. 0.714±0.090,both P<0.01). Iron deposition could induce HSCs to expressα-SMA in great amount,while apoptosis could be seen scarcely in iron deposited HSCs. By desferrioxamine therapy,α-SMA expression of HSCs was decreased significantly,but some of the cells underwent apoptosis. Conclusion Different iron load levels inside HSCs can induce activation or apoptosis of the cells,showing that iron plays an important role in regulating the process of HSCs activation and apoptosis and revealing that desferrioxamine possesses the potential action for treatment of liver fibrosis.

Influence and mechanism of mitochondrial permeability transition pore and cytochrome C in process of HL-60 cell apoptosis induced by desferrioxamine / 中华实用儿科临床杂志

Objective To explore the influence of mitochondrial permeability transition pore opening and cytochrome C (Cyt C) being discharged on the apoptotic mechanism of HL-60 cell induced by desferrioxamine (DFO),so as to provide scientific basis for the clinicians to adopt the strategy of iron deprivation to treat human leukemia.Methods HL-60 cells were co-cultivated with various concentration of DFO for 24-72 hours,then the apoptotic cells and the changes of mitochondrial membrane potential(△Ψm) were examined by means of flow cytometry(FCM),and Cyt C in cytoplasm was detected by way of celluar immunohistochemistry.Results The cell apoptotic rate assumed rising tendency as the highest rate could be up to (44.10 ± 6.3 1) ％,and the effect was of time-and-dose dependence (P ＜0.01).FCM could detect the △Ψm declining(P ＜ 0.05),and the Cyt C positive cell rate was higher than the controls,the differences were of statistical significance(P ＜ 0.05).Conclusions DFO can induce the HL-60 cells apoptosis,and the possible mechanism is that DFO make the mitochondrial permeability transition pore open and get Cyt C discharged from the mitochondria.

Desferrioxamine-related ocular toxicity: A case report.

A 29-year-old lady receiving repeated blood transfusions for β thalassemia since childhood, presented with rapidly deteriorating symptoms of night blindness and peripheral visual field loss. She was recently commenced on high-dose intravenous desferrioxamine for reducing the systemic iron overload. Clinical and investigative findings were consistent with desferrioxamine-related pigmentary retinopathy and optic neuropathy. Recovery was partial following cessation of desferrioxamine. This report highlights the ocular side-effects of desferrioxamine mesylate and the need to be vigilant in patients on high doses of desferrioxamine.

A clinical audit of thalassaemia management at the Lady Ridgeway Hospital for Children, Colombo.

Objective: To assess the adherence of management of beta thalassaemia major patients at Lady Ridgeway Hospital to an established standard treatment protocol Method: A clinical audit was carried out in all six medical wards of Lady Ridgeway Hospital from 1st February 2008 to 31st March 2008 with retrospective data collected over the period 1st January 2005 to 31st December 2007. The study population comprised all beta thalassaemia major patients admitted to the wards during the study period. Patients who did not give consent and those having other transfusion dependant anaemias were excluded from the study. The study instrument used was a pretested structured data collection form. Data collection was done by referring the past medical records. Data on ‘compliance’ was based on recall by the parent. Data analysis was done on a Microsoft Excel worksheet. Results: During the study period data was collected from 61 patients. Age at time of diagnosis ranged from 2 months to 5 years. All patients had their diagnosis confirmed by haemoglobin electrophoresis, high performance liquid chromatography or both tests. Pre-transfusion haemoglobin levels ranged from 4.1 mg/dl to 11.2 mg/dl. Number of blood transfusions per year ranged from 4–18 per year. Almost 50% of the patients had serum ferritin levels above the potentially cardiotoxic level of 2500 µg/l. Conclusions: Compliance of the patients with the treatment protocol was unsatisfactory. A high proportion of patients had cardiotoxic levels of serum ferritin.

Chelation therapy with desferrioxamine does not normalize ferritin level but attenuates oxidative damage and improves total antioxidant level in malaysian Chinese β-thalassaemia major patients / La terapia de quelación con deferoxamina no normaliza los niveles de ferritinaa pero atenúa el daño oxidativo y mejora el nivel antioxidante total en los pacientes sinomalayos que padecen de talasemia β

Beta-thalassaemia major causes severe anaemia and patients with it may be transfusion-dependent for life. Regular blood transfusions cause iron-overload that leads to oxidative damage which can hasten mortality. The objective of this research was to study the oxidant-antioxidant indices in β-thalassaemia major patients at the University of Malaya Medical Centre (UMMC) who were on desferrioxaminechelation or without chelation therapy. Blood was collected from 39 Chinese patients and 20 controls. Plasma and peripheral blood mononuclear cell lysates (PBMC) were extracted and biochemical tests to evaluate oxidative stress were performed. Oxidative stress was evident in these patients as advanced oxidized protein products (AOPP) and lipid hydroperoxides were elevated, whereas glutathione peroxidase activity and the ferric reducing antioxidant power (FRAP) were reduced. The catalase activity in the patients' PBMC was elevated, possibly as a compensatory mechanism for the reduced glutathione peroxidase activity in both red blood cells and PBMC. The lower FRAP and higher AOPP levels in the non-chelated patients compared with the chelated patients were indicative of a lower oxidative stress level in the chelated patients. The ferritin levels in the chelated and non-chelated patients were high and the mean levels of liver enzyme activities in the majority of patients were elevated regardless of chelation therapy. In conclusion, this study indicates that desferrioxamine chelation therapy does not normalize ferritin level but attenuates oxidative damage and improves total antioxidant level in Malaysian Chinese β-thalassaemia major patients.

La beta-talasemia mayor causa anemia severa, y los pacientes con este padecimiento pueden hacerse dependientes de las transfusiones de sangre por el resto de sus vidas. Las transfusiones regulares de sangre dan lugar a una sobrecarga de hierro que conduce al dano oxidativo, el cual a su vez puede acelerar la mortalidad. El objetivo de esta investigación fue estudiar las tasas de oxidantesantioxidantes en pacientes de beta-talasemia mayor en el Centro Médico de la Universidad de Malaya, tanto aquellos bajo tratamiento de quelación con deferoxamina, como aquellos sin terapia de quelación alguna. Se recogieron muestras de sangre de 39 pacientes chinos y 20 controles. Se extrajeron plasma y lisados de celulas mononucleares perifericas (CMSP), y se realizaron pruebas bioquimicas para evaluar el estrés oxidativo. El estrés oxidativo era evidente en estos pacientes en forma de productos avanzados de oxidación de proteinas (PAOP), y los hidroperoxidos de lipidos eran elevados, en tanto que la actividad de glutatión peroxidasa y el poder reductor ferrico/antioxidante (FRAP) era reducida. La actividad de la catalasa en los pacientes de CMSP era elevada, posiblemente como un mecanismo compensatorio frente a la actividad de glutatión peroxidasa reducida tanto en los globulos rojos como en las CMSP. Los niveles más bajos de FRAP y los más altos de PAOP en los pacientes no quelados en comparación con los pacientes quelados, indicaban un bajo nivel de estrés oxidativo en los pacientes quelados. Los niveles de ferritina tanto en los pacientes quelados como en los no quelados, eran altos, y los niveles promedio de actividades enzimaticas del higado fueron elevados en la mayoria de los pacientes, independientemente de la terapia de quelación. En conclusión, este estudio indica que la terapia de quelación con deferoxamina no normaliza el nivel de ferritina, pero en cambio atenua el daño oxidativo, y mejora el nivel antioxidante total en los pacientes sinomalayos afectados por la betatalasemia mayor.

Comparison between Pseudomonas aeruginosa siderophores and desferrioxamine for iron acquisition from ferritin

Background: Siderophore is an iron chelator produced by microorganism. Pseudomonas aeruginosa produces two siderophores (pyoverdin and pyochelin). Desferrioxamine is a siderophore used in thalassemia patients to treat an iron overload of vital organs. Objective: Compare the ability of pyoverdin, pyochelin, and desferrioxamine for iron mobilization from ferritin. Materials and Methods: In vitro experiment, the ability of P. aeruginosa siderophores and desferrioxamine for iron mobilization from ferritin was compared by using a dialysis membrane assay at pH values of 7.4 and 6.0. Stimulation of P. aeruginosa PAO1 growth by all siderophores was studied in glucose minimum medium. Results: All three compounds were capable of iron mobilization at both pHs. At pH 6.0, the most effectiveness compound was desferrioxamine (31.6%), followed by pyoverdin (21.5%) and pyochelin (13.7%) compared on weight basis, each at 10 μg/mL. At equimolar concentration, their activities were desferrioxamine (38.5±1.2%), followed by pyoverdin (32.0±4.8%) and pyochelin (26.7±1.9%), respectively. Conclusion: The most effective compound in iron mobilization from ferritin was desferrioxamine, followed by pyoverdin and pyochelin respectively.

Multiple transfused thalassemia major: Ocular manifestations in a hospital-based population.

Purpose: To study the ocular manifestations in multiple transfused beta-thalassemia major patients and assess the ocular side-effects of iron chelating agents. Materials and Methods: In this prospective observational study, 45 multiple transfused beta-thalassemia major children between six months and 21 years of age were enrolled and assigned groups according to the treatment regimens suggested. Group A received only blood transfusions, Group B blood transfusions with subcutaneous desferrioxamine, Group C blood transfusions with desferrioxamine and oral deferriprone and Group D blood transfusions with deferriprone. Ocular status at the time of enrolment was documented. Subjects were observed quarterly for one year for changes in ocular status arising due to the disease process and due to iron chelation therapy. Children with hemoglobinopathies other than beta-thalassemia major, congenital ocular anomalies and anemia due to other causes were excluded. Results: Ocular involvement was observed in 58% of patients. Lenticular opacities were the most common ocular finding (44%), followed by decreased visual acuity (33%). An increased occurrence of ocular changes was observed with increase of serum ferritin and serum iron levels as well as with higher number of blood transfusions received. Desferrioxamine seemed to have a protective influence on retinal pigment epithelium (RPE) mottling. Occurrence of lenticular opacities and RPE degeneration correlated positively with use of desferrioxamine and deferriprone respectively. Follow-up of patients for one year did not reveal any change in ocular status. Conclusion: Regular ocular examinations can aid in preventing, delaying or ameliorating the ocular complications of thalassemia.

A Comparative Study on the Enhancement Efficacy of Specific and Non-specific Iron Chelators for Protoporphyrin IX Production and Photosensitization in HaCat Cells / 华中科技大学学报（医学）（英德文版）

The iron chelators can be utilized in target cells to improve 5-aminolaevulinic acid (ALA)-based photodynamic therapy (PDT). The purpose of this study is to compare the effect of two kinds of iron chelators,desferrioxamine (DFO) and ethylenediaminetetraacetic acid (EDTA) on the enhancement of ALA-PDT. HaCat cells were cultured in medium containing 2.0 mmol/L of ALA and 0.5 mmol/L of DFO or EDTA. After 3-h incubation in the dark,the concentration of cellular protoporphyrin IX (PpIX) was detected by high performance liquid chromatography (HPLC),and the fluorescence of PpIX was observed at 630 nm emission under confocal laser scanning microscope.For PDT,HaCat cells were irradiated using 632.8 nm laser,and the fractions of apoptotic and necrotic cells were flow cytometricaUy assayed. Related differences in morphology and ultrastructure of HaCat cells were observed using optical microscope or transmission electron microscope. Compared to incubation with ALA alone,the addition of DFO or EDTA increased the concentration of cellular PpIX and the fluorescent density of PpIX,and also increased cell death ratio after PDT. PDT using ALA plus DFO produced the highest cellular PpIX level,greatest cell death ratio and most severe structural damage to the cells. It was concluded that both DFO and EDTA could enhance ALA-based PpIX production and PDT. Compared to the non-specific iron chelator of EDTA,the specific chelator,DFO,showed more potential for the enhancement.

The Effect of Iron Depletion on the Monocytic Adhesion, Differentiation and SR-A Expression / 대한해부학회지

Maintenance of cellular iron homeostasis is a prerequisite for proliferation and differentiation of cells, and is also a central role in the regulation of immune function. Monocyte-macrophages play an important roles in host defense, particularly in the inflammatory process of acute and chronic disease. The reason that an iron is important in these cell is because an iron is indispensable in a generation of hydroxyl radical for bacterium killing. Because of the role of iron in the monocytic THP-1 cell differentiation is not become clear, we investigated whether THP-1 cell can differentiate to macrophage-like cell using of iron and iron chelator which cause iron depletion. The cell differentiation was not able to observe by iron treatment, by the way, the cell adhesion was increased in DFO treated monocyte and cellular pseodopodial extension, change of a nucleus-cytoplasmic ratio were showed in Differential interference contrast (DIC) and Giemsa staining, and it was inhibited by ferric citrate (FC). Increased polystyrene bead phagocytosis by DFO treatment of THP-1 cell were detected through FACS and rhodamine-phallodin staining. The SR-A expression, which was a cell differentiation marker, was increased by DFO treatment of THP-1 cell. These results suggest that iron depletion by DFO can promote THP-1 cell diffentiation into macrophage-like cell, and this may carrying out important role in the immune response.

Pathologic Scoring and Postoperative Liver Function in Canine Partial Liver Transplantation: after Desferrioxamine Exposure / 대한이식학회지

PURPOSE: Liver biopsy plays an important role in the histopathological evaluation of the transplanted liver, but till now pretransplant graft biopsy has limited role in predicting primary non function of the graft. Desferrioxamine (DFO), the iron chelating agent, has been known to be effective in reducing rat liver ischemia-reperfusion injury. We tried desferrioxamine in canine partial liver transplantation, and pathologic scores were compared. METHODS: ~70% partial liver was harvested and reimplanted in same mongrel dog weighing about 25 kg. Desferrioxamine (20 mg/kg) was infused via splenic vein just from the beginning of reperfusion of the partial liver graft (n=5). Serum aspartate aminotransferase (AST) Alkaline phosphatase (ALP), Lactate dehydrogenase (LDH) were checked and compared with the control group (n=5). Morphological liver injury score were compared to the control group. Statistical analysis was done with independent T-test. RESULTS: Total ischemic time was 4 hours and 42 minutes in average. AST level was significantly lower in Desferrioxamine group at 1 hour and 48 hours after reperfusion, (P=0.4) ALP level was significantly lower in desferrioxamine group at 48 hours after reperfusion (P=0.4). LDH level in desferrioxamine group was lower than that of control group but without statistical significance. The pathologic score at 1 hour after reperfusion showed a reduced degree of sinusoidal injury among the DFO group but the difference was not statistically significant. The pathologic score just before harvest of the graft showed no correlation with serum AST, ALP, LDH levels at that time or at 1 hour or 48 hours after reperfusion. Only the pathologic score at 1 hour after reperfusion had significant correlation with the serum LDH levels at 48 hours after reperfusion. CONCLUSION: In canine live donor partial liver transplantation, desferrioxamine infusion just before reperfusion might be an effective way of reducing ischemia-reperfusion injury. And the pathologic grading on samples obtained at 1 hour after reperfusion showed a significant correlation with subsequent liver function

A Study for Improvement of Erythropoietin Responsiveness in Hemodialysis Patients / 영남의대학술지

BACKGROUND: Anemia in chronic renal failure plays an important rolr in increasing morbidity of dialysis patients. The causes of the anemia are multifactorial. With using of erythropoietin(EPO), most of uremia-induced anemia can be overcome. However, about 10% of renal failure patients shows EPO-resistant anemia. Hyporesponsiveness to EPO has been realted to many factors: iron deficiency, aluminum intoxication, inflammations, malignancies and secondary hyperparathyroidism. So I evailuated the improvement of EPO responsiveness after correction of above several factors. MATERIALS AND METHODS: Seventy-two patients on hemodialysis over 6 months were treated with intravenous ascorbic acid(IVAA, 300 mg t.i.w. for 12 weeks). After administration of IVAA for 12 weeks,patients were classified into several groups according to iron status, serum aluminum levels and i-PTH levels. Indivisualized treatments were performed; increased iron supplement for absolute iron deficiency, active vitamin D3 for secondary hyperparathyroidism and desferrioxamine(DFO, 5 mg/kg t.i.w.) for aluminum intoxication or hyperferritinemia. RESULTS: 1) Results of IVAA therapy for 12 weeks on all patients(n=72) Hemoglobin levels at 2,4,6 week were significantly elevated compared to baseline. but those of hemoglobin at 8, 10, 12 week were not significantly different. 2) Result of IVAA therapy for 20 weeks on patients with 100 microgram/1< or =ferritin<500 microgram/1 and transferrin saturation(Tsat) below 30%(n=30) After treatment of IVAA for 12 weeks, patients were evaluated the response of therapy according to iron status. Patient with 100 microgram/1< or =ferritin?500 microgram/1 and Tsat below 30% showed the most effective response. These patients were treated further for 8 weeks. Hemoglobin levels at 2, 4 week were significantly increased compared to baseline with significantly reduced doses of EPO at 2, 4, 10, 12, 16, 20 week. Concomitantly significantly improvement of Tsat at 2, 6, 16, 20 week compared to baseline were identified. 3) Result of IVAA therapy for 12 weeks followed by DFO therapy for 8 weeks on patients with serume aluminum above 4 microgram/1(n=12) Hemoglobin levels were not significantly increased during IVAA therapy for 12 weeks but dosages of EPO were significantly decreased at 2, 4, 6, 8 week during DFO therapy compared to pre-treatment status. CONCLUSION: IVAA can be helpful for the treatment of the anemia caused by functional iron deficiency and can reduce the dosage of EPO for anemia correction. And administration of low dose DFO, in cases of increased serum aluminum level, can reduce the requirment of EPO.

The Protective Effect of Vitamin E and Desferrioxamine on Cultured Cerebral Neurons of Neonatal Mouse Damaged by Ischemic Condition

PURPOSE: Perinatal asphyxia is an important cause of neurologic morbidity. Experiments in animal models of hypoxic-ischemic brain injury demonstrate that brain damage starts during hypoxia-ischemia. In order to evaluate the ischemic condition-induced neurotoxic effect in view of oxi-dative stress, we examined the cytotoxic effect in cultured cerebral neurons of neonatal mouse. METHODS: Dissociated cell cultures were prepared from cerebrum of neonatal mouse. Tissues were diced into small pieces and were incubated in phosphate buffered saline at 37degrees C. Isolated cells were resuspended in the medium and plated in poly-L-lysine coated 96 well multichambers at a cell density of 5x104cells/well. Cells were grown in a 5% CO2/95% air atmosphere at 37degrees C. Cytotoxic effects were examined in the cultured cerebral neurons with time interval in the ischemic condition with a 95% nitrogen/5% CO2. And the protective effect of vitamin E and desferrioxamine as an antioxidant was examined by MTT assay and neurofilament enzymeimmunoassay(EIA). Microscopic examinations were also done. RESULTS: Ischemic condition markedly decreased the cell viability in a time-dependent manner in cultured cerebral neurons. MTT50 value was estimated at 10 minutes, when cerebral neurons were incubated for various time intervals in ischemic condition. Under light microscopy, the number of cells and neurites were decreased when cerebral neurons were cultured for 10 minutes in the ischemic condition. Vitamin E was an effective antioxidant in blocking ischemic condition-induced neurotoxicity, while desferrioxamine was not in these cultures. CONCLUSION: It is suggested that ischemic conditions are neurotoxic and selective antioxidant such as vitamin E is effective in protecting against the neurotoxicity induced by ischemic condition in cultured cerebral neurons of neonatal mouse.

Long-term Effect of Desferrioxamine to rHuEPO Regident Anemia in Hemodialysis Patients / 영남의대학술지

There are several factors concerning to anemia in chronic renal failure patients. But when rHuEPO is used, most of these factors can be overcome, and the levels of hemoglobin are increased, However, about 10% of the renal failure patients represent rHuEPO-resistant anemia eventhough high dosage of rHuEPO. For these cases, desferrioxamine can be applied to correct rHuEPO resistnacy, and many mechanism og DFO are arguing. So we are going to know whether DFO can applied to correct anemia of the such patients, how long its effect can continued. The seven patients as experimental group(DFO+EPO) who represent refractoriness to rHuEPO and the other seven patients as control group(EPO) were included. Experimental group has lower than 9 g/dL of hemoglobin levels despite high rHuEPO dosage (more than 4000U/Wk) and showed normochromic anemia. There were no definitive causes of anemia such as hemorrhage or iron deficiency. Control group patients has similar characteristics in age, mean dialysis duration but showed adequate response to rHuEPO. DFO was administered to experimental group for 8 weeks along with rHuEPO(the rHuEPO individual mean dosage had been determined by mean dosage of the previous 6 months. Total mean dosage; 123.5 U/Kg/Wk). After 8 weeks of DFO administration, the hemoglobin and rHuEPO dosage levels were checked for 15 consecutive months. It should be noted that the patients determined their own rHuEPO dosage levels according to hemoglobin levels and economic status. In control group, rHuEPO was administered by the same method used in experimental group without DFO through the same period. Fifteen months of ovservation period after DFO trial were divided as Time I(7 months after DFO trial) and Times II(8 months after Time I). The results are as follows: Before DFO trial, mean hemoglobin level of experimental group was 7.8 g/dL, which is similar level(p>0.05) to control group(mean Hb; 8.2 g/dL). But in experimental group, significantly(p<0.05) higher dosages of rHuEPO(mean; 123.5 U/Kg/Wk) than control group (mean;41.6 U/Kg/Wk) had been used. It means resistancy to rHuEPO of experimental group. But after DFO trial, the hemoglobin levels of the experimental group were increased significantly(p<0.05), and these effect were continued to II.(Time I; mean 8.6g/dL, Time II; mean 8.6g/dL) The effects of DFO to hemoglobin were continued for 15 months after DFO trial with simiral degree through Time I, Time II. Also, rHuEPO dosage used in the experimental group were decreased to simiral levels of the control group after DFO trial and these effect were also continued for 15 months(Time I; mean 48.1 U/Kg/Wk. Time II; mean 51.8 U/Kg/Wk). In the same period, hemoglobin levels and rHuEPO dosages used in the control group were not changed significantly. Notibly, hemoglobin increment and rHuEPO usage decrement in experimental group were showed maxilly in the 1st month after DFO trial. That is, after the use of DFO, erythropoiesis was enhanced with a reduced rHuEPO dosage. So we think rHuEPO reisistancy can be overcome by DFO therapy. In conclusion, the DFO can improve the anemia caused by chronic renal failure at least over 1 year, and hence, can reduce the dosage of rHuEPO for anemia correction. Additional studies in order to determined the mechanism of DFO on erythropoiesis and careful attention to potential side effects DFO will be needed.

Effect of Desferrioxamine Therapy in Patients with Transfusional Hemosiderosis Due to Severe Aplastic Anemia / 대한소아혈액종양학회지

BACKGROUND: This study was carried out to evaluate the efficacy of desferrioxamine as a chelating agent in iron overloaded patients with severe aplastic anemia due to multiple transfusion. METHODS AND MATERIALS: From Oct. 1995 to Aug. 1996, 15 patients with aplastic anemia, diagnosed from May 1995 to Jan. 1996 at St. Mary's Hospital, who had a transfusional hemosiderosis were included in this study. They received 19 courses of high-dose desfer-rioxamine therapy for 6 days(20 to 30 mg/kg daily as a 24-hour intravenous infusion) . Before and after treatment, we measured serum ferritin, iron, TIBC, 24-hour urinary excretion of iron. RESULTS: 1) The range of iron load before treatment was between 4.5 and 20.0 gram. 2) Because of limit of detection(1,800 microgram/L), it was difficult to compare the changes of serum ferritin level after therapy to those of before therapy. 3) There was no significant differences between the levels of serum iron before and after therapy(214.3+/-62.8 vs 220.0+/-53.3). And there was no significant differences between TIBC before and after therapy(235.8+/-64.6 vs 259.4+/-60.1). 4) Iron/TIBC ratios were significantly deceased after desferrioxamine treatment compared to those of before therapy(0.90+/-0.04 vs 0.85+/-0.04, P<0.001) and mean urinary excretions of iron were increased by high-dose desferrioxamine compared to those by test dose(6.5+/-7.6 vs 29.1+/-14.3, P<0.001) CONCLUSION: High-dose desferrioxamine therapy is very effective for chelating and excretion of iron in iron overloaded patients with severe aplastic anemia due to multiple transfusion. A repeat administration of desferrioxamine is necessary for the iron overloaded patient to eliminate the risk of a transfusional hemosidersis.