A Mini Review: Mucormycosis in Coronavirus Disease-19, Host-Iron Assimilation, and Probiotics as Novel Therapy

Mucormycosis is an acute fungal infection with 90% of cases in the form of rhino-orbito-cerebellar. It is an aggressive and life-threatening fungal infection causing 50% mortality in people with coronavirus disease 2019 (COVID-19). In COVID-infected patients due to, diabetic ketoacidosis, epithelial damage, ciliary dysfunction, dysfunctional phagocytic mechanism, and immunosuppression, there is impaired chemotaxis and defective intracellular killing leads to fungal spores to invade, germinate and penetrate in surrounding tissues. The use of broad-spectrum antibiotics disrupts the normal microbiomes and increases the probability of growth of Rhizopus spp. Commercially available probiotics such as Lactobacillus, Bifidobacterium, Enterococcus, Streptococcus, and Saccharomyces when administered in adequate quantities form siderophores which induces iron stress in fungus and inhibits spore germination.

Efecto del EDTAC y del ácido cítrico sobre la pared dentinaria. Variación del tiempo de exposición y la edad dentaria / Effect of EDTAC and citric acid on dentinal walls. Variation of exposure time and dental age

The aim of this study was to find a formula and application time for chelators effective in cleaning the root canal without causing erosion and considering dental age. The sample included 120 teeth: 60 taken from young patients and 60 from adult patients. They were instrumented and irrigated with 2.5% sodium hypochlorite (NaOCl). Each subgroup was divided randomly into six groups: 4 groups of 12 teeth and 2 control groups of 6 teeth. In the final irrigation, 17% ethylenediaminetetraacetic acid plus Cetavlón (EDTAC) or 10% citric acid was applied for 1 or 3 minutes according to each group. The results showed a high level of cleanliness, and a few showed erosion of the dentinal tubules. Satisfactory results were obtained in the removal of the smear layer when applying EDTAC or citric acid combined with NaOCl. Erosion was present in different degrees regardless of dental age, but it was indeed affected by the irrigant exposure time.

O objetivo deste estudo foi obter uma fórmula e um tempo de aplicação dos quelantes efetivos que permitam a limpeza das paredes do canal sem causar erosões, levando em consideração a idade dental. A amostra foi composta por 120 dentes, 60 de pacientes jovens e 60 de pacientes adultos, foram instrumentados e irrigados com hipoclorito de sódio (NaOCl) a 2,5%. Cada subgrupo foi dividido aleatoriamente em 6 grupos: 4 grupos de 12 dentes e 2 grupos de controle com 6 dentes cada um. Na irrigação final, ácido etilenodiaminotetracético com Cetavlón (EDTAC) 17% ou ácido cítrico 10% foi aplicado por 1 ou 3 minutos, dependendo do grupo. Os resultados mostraram um bom nível de limpeza com algumas amostras com erosão dos túbulos dentinários. Com EDTAC ou ácido cítrico combinado com NaOCl, resultados satisfatórios foram obtidos na remoção da camada de esfregaço . A erosão esteve presente em seus diferentes graus independentemente da idade dentária, mas não do tempo de exposição do irrigante.

Evolución clínica de pacientes en hemodiálisis en tratamiento con oxihidróxido sucroférrico / Clinical evolution of patients treated with sucroferric oxyhydroxide in hemodialysis

Resumen Introducción: la hiperfosfatemia es una complicación común de la enfermedad renal crónica (ERC) y empeora progresivamente a medida que disminuye la función renal. Actualmente disponemos de diversas moléculas farmacéuticas para su tratamiento. Dentro de ellas, existen quelantes que contienen hierro, como es el caso del oxihidróxido sucroférrico. Su uso se ha extendido fundamentalmente entre pacientes en hemodiálisis, en sustitución de otros quelantes. Objetivo: describir la tolerabilidad, la aparición de efectos secundarios, la adherencia terapéutica y las cifras de fósforo sérico en pacientes en tratamiento con oxihidróxido sucroférrico en nuestro centro. Materiales y métodos: se analizaron 5 pacientes de la unidad de hemodiálisis del Servicio de Nefrologia del Hospital Universitario de Burgos, España, en el periodo comprendido entre enero de 2017 a mayo de 2018, todos ellos en tratamiento con oxihidróxido sucroférrico. Se evaluaron las concentraciones plasmáticas de fósforo, calcio y hormona paratiroidea durante el tratamiento con oxihidróxido sucroférrico, además de los efectos secundarios y las causas de abandono. El análisis de los datos se realizó mediante el software estadístico IBM SPSS 22 con un intervalo de confianza del 95 %. Se evaluaron las posibles diferencias con el análisis de la t-Student. Resultados: se evidenció una reducción media del 12,27 % de la hiperfosforemia y una reducción en el número de comprimidos diarios del 15,79 %, con buena tolerancia del fármaco en todos los casos. No se evidenció reducción estadísticamente significativa en los niveles plasmáticos de calcio, ni de hormona paratiroidea (PTH). Conclusiones: el oxihidróxido sucroférrico es un fármaco bien tolerado, que generó una disminución de los niveles séricos de fósforo en la población estudiada. Sin embargo, dado el bajo número de casos analizados, no es posible recomendar el uso terapéutico de este fármaco como primera línea de tratamiento de la hiperfosforemia.

Abstract Introduction: Hyperphosphatemia is a common complication of CKD and progressively worsens as renal function decreases. Currently we have several pharmaceutical molecules for its treatment. Among them, there are chelators that contain iron, as is the case of sucroferric oxyhydroxide. Its use has been extended mainly among those on hemodialysis, replacing other chelators. Objective: Describe the tolerability, the appearance of side effects, therapeutic adherence and serum phosphorus levels in patients undergoing treatment with sucroferric oxyhydroxide in our center. Materials and methods: Five patients were analyzed from the hemodialysis unit of the Nephrology Service of the University Hospital of Burgos, from January 2017 to May 2018, all of them under treatment with sucroferric oxyhydroxide. Plasma concentrations of phosphorus, calcium and parathyroid hormone were evaluated during treatment with sucroferric oxyhydroxide, in addition to side effects and causes of abandonment. For the analysis of the data, they were processed using the IBM SPSS 22 statistical software with a confidence interval of 95%. Possible differences were evaluated with the t-Student analysis. Results: There was an average reduction of 12.27% in hyperphosphataemia and a reduction in the number of daily tablets of 15.79%, with good tolerance of the drug in all cases. There was no statistically significant reduction in plasma levels of calcium or parathyroid hormone (PTH). Conclusions: Sucroferric oxyhydroxide is a well-tolerated drug, which generated a decrease in serum phosphorus levels in the population studied. However, given the low number of cases analyzed, it is not possible to recommend the therapeutic use of this drug as the first line of treatment for hyperphosphatemia.

Antioxidant Activities of Chicken Egg White Hydrolysates Obtained by New Purified Protease of Aspergillus avenaceus URM 6706

Abstract Protein hydrolysates originating from egg white have already been reported to be bioactive and, among their biological activities, possess the antioxidant property that protects the body from early ageing and diseases linked to oxidation. Therefore, the objective of this work was to evaluate the antioxidant activity of hydrolysates obtained by the hydrolysis of egg white from hen poultry. The protease produced by Aspergillus avenaceus URM 6706 was purified and subsequently applied to hydrolysate the egg white, and the degree of hydrolysis was verified during the protease exposure time (4-24 h). The hydrolysis was intensified over time of exposure to the protease. It was possible to detect the antioxidant activities of eliminating the 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) radical (ABTS•+) from 97% to 99% and 2,2-diphenyl-1-picrylhydrazyl (DPPH•) up to 27%, as well as the chelation of Cu2+ metal ions up to 62% and Fe2+ up to 54%. The elimination of ABTS•+ radical had a positive correlation with the degree of hydrolysis; however, all the other activities tested showed a negative correlation with the degree of hydrolysis. The results obtained suggest that the egg white of hen chicken represents a food source of animal origin with potential application in the functional food industry.

Hepatic and Cardiac Iron-load in Children on Long-term Chelation with Deferiprone for Thalassemia Major

Objective: To evaluate the efficacy of prolonged deferiprone monotherapy in patients with ?-thalassemia major. Methods: This cross-sectional study included 40 patients (age range 9 to38 years) with thalassemia major receiving deferiprone for ?5 years. Serum ferritin, andmyocardial iron concentration (MIC) and liver iron concentration (LIC) assessed by T2*MRIwere recorded. Results: The patients were receiving deferiprone for a mean (SD) duration of12.1 (4.7) years. The median (IQR) dose of deferiprone was 85 (74.3, 95) mg/kg/day. TheMIC was normal or had a mild, moderate or severe elevation in 29 (72.5%), 3 (7.5%), 3(7.5%), and 5 (12.5%) patients. The LIC was normal or had a mild, moderate or severeelevation in 2 (5%), 4 (10%), 11 (27.5%) and 23 (57.5%) patients. Conclusions: The majorityof patients receiving deferiprone had a moderate/severe hepatic but normal cardiac iron load.Prolonged deferiprone monotherapy was suboptimal for hepatic iron load in the majority.

A concurrent parallel study to compare the efficacy and safety of oral iron chelators, defrasirox and defriprone in patients of beta thalassaemia major

Background: This study was planned to evaluate all the cases of ? thalassaemia major, already receiving one of the oral iron chelators for a comparison among the efficacy, safety and economy of deferasirox and deferiprone to establish the better option in an Indian scenario.Methods: We identified two groups of patients: 38 treated with deferasirox and 35 treated with deferiprone. Laboratory parameters such as serum ferritin, creatinine, SGPT, Hb, CBC and urine were recorded at the time of inclusion and at 1, 3 and 6 months after the inclusion. The primary outcome variable was serum Ferritin level at the start and at the end of study. Serum ferritin level was carried out by microparticle enzyme linked immunoassay.Results: Before the study, the mean hemoglobin level was 7.32±1.50mg/dL ranged from 4 to 10.8 in deferasirox group and 7.54±1.15mg/dL ranged from 5.5 to 8.8 in deferiprone group. At the time of inclusion, study population was characterized by a mean serum ferritin value of 4735.11±450.01 SE in deferasirox and 4315.97±340.75 SE in deferiprone group. After one month the mean serum ferritin increases to 4578.66±371.96 in deferasirox and 4388.82±316.16 in deferiprone group. After three month the mean serum ferritin reduces to 4295.60±377.37 in deferasirox and 3988.88±349.84 in Deferiprone group.Conclusions: Thus, we conclude that deferasirox and deferiprone are well tolerated, have few adverse effects and almost have a comparable effect in lowering of the patient's serum ferritin level. Deferiprone is more cost effective but needs a strict control on compliance owing to requirement in three divided doses per day.

Influence of iron and copper on the activity of laccases in Fusarium oxysporum f. sp. lycopersici

ABSTRACT Fusarium oxysporum f. sp. lycopersici is a phytopathogenic fungus that causes vascular wilt in tomato plants. In this work we analyze the influence of metal salts such as iron and copper sulphate, as well as that of bathophenanthrolinedisulfonic acid (iron chelator) and bathocuproinedisulfonic acid (copper chelator) on the activity of laccases in the intra (IF) and extracellular fractions (EF) of the wild-type and the non-pathogenic mutant strain (rho1::hyg) of F. oxysporum. The results show that laccase activity in the IF fraction of the wild and mutant strain increased with the addition of iron chelator (53.4 and 114.32%; respectively). With copper, it is observed that there is an inhibition of the activity with the addition of CuSO4 for the EF of the wild and mutant strain (reduction of 82 and 62.6%; respectively) and for the IF of the mutant strain (54.8%). With the copper chelator a less laccase activity in the IF of the mutant strain was observed (reduction of 53.9%). The results obtained suggest a different regulation of intracellular laccases in the mutant strain compared with the wild type in presence of CuSO4 and copper chelator which may be due to the mutation in the rho gene.

A Systematic Comparative Evaluation of ⁶⁸Ga-Labeled RGD Peptides Conjugated with Different Chelators / 대한핵의학회잡지

PURPOSE: The present paper reports a systematic study on the effect of bifunctional chelators (BFC) namely, NOTA, DOTA, and DTPA, on the radiochemical formulation, in vitro stability, and in vivo biological properties of ⁶⁸Ga-labeled RGD peptide derivatives.METHODS: The three RGD conjugates namely, NOTA-Bn-E-[c(RGDfk)]₂, DOTA-Bn-E-[c(RGDfk)]₂, and DTPA-Bn-E-[c(RGDfk)]₂ were radiolabeled with ⁶⁸Ga and the radiolabeling was optimized with respect to the ligand amount, radiolabeling time, and temperature. Further, the ⁶⁸Ga complexes were assessed for their in vitro and in vivo stabilities. The biodistribution studies of the three radiolabeled conjugates were carried out in C57BL/6 mice bearing melanoma tumor at 30 min and 1 h post-adimistration.RESULTS: NOTA-Bn-E-[c(RGDfk)]₂ could be radiolabeled with ⁶⁸Ga at room temperature while DOTA-Bn-E-[c(RGDfk)]₂ and DTPA-Bn-E-[c(RGDfk)]₂ were radiolabeled at high temperature. ⁶⁸Ga-NOTA-Bn-E-[c(RGDfk)]₂ was found to be the most kinetically rigid in in vitro stability assay. The uptake of the three radiolabeled peptide conjugates in melanoma tumor was comparable at 1 h post-administration (NOTA; DOTA; DTPA (% I.D./g):: 2.78 ± 0.38; 3.08 ± 1.1; 3.36 ± 0.49). However, the tumor/background ratio of ⁶⁸Ga-NOTA-Bn-E-[c(RGDfk)]₂ was the best amongst the three radiotracers. ⁶⁸Ga-complexes of NOTA-Bn-E-[c(RGDfk)]₂ and DOTABn-E-[c(RGDfk)]₂ showed excellent in vivo stability while ⁶⁸Ga-DTPA-Bn-E-[c(RGDfk)]₂ showed significant metabolic degradation.CONCLUSION: These studies show that ⁶⁸Ga-NOTA-Bn-E-[c(RGDfk)]₂ would be the most appropriate ⁶⁸Ga-labeled radiotracer and the most amenable for kit formulation.

Influence of iron and copper on the activity of laccases in Fusarium oxysporum f. sp. lycopersici

ABSTRACT Fusarium oxysporum f. sp. lycopersici is a phytopathogenic fungus that causes vascular wilt in tomato plants. In this work we analyze the influence of metal salts such as iron and copper sulphate, as well as that of bathophenanthrolinedisulfonic acid (iron chelator) and bathocuproinedisulfonic acid (copper chelator) on the activity of laccases in the intra (IF) and extracellular fractions (EF) of the wild-type and the non-pathogenic mutant strain (rho1::hyg) of F. oxysporum. The results show that laccase activity in the IF fraction of the wild and mutant strain increased with the addition of iron chelator (53.4 and 114.32%; respectively). With copper, it is observed that there is an inhibition of the activity with the addition of CuSO4 for the EF of the wild and mutant strain (reduction of 82 and 62.6%; respectively) and for the IF of the mutant strain (54.8%). With the copper chelator a less laccase activity in the IF of the mutant strain was observed (reduction of 53.9%). The results obtained suggest a different regulation of intracellular laccases in the mutant strain compared with the wild type in presence of CuSO4 and copper chelator which may be due to the mutation in the rho gene.

Analysis of the shelf life of chitosan stored in different types of packaging, using colorimetry and dentin microhardness

OBJECTIVES: Chitosan has been widely investigated and used. However, the literature does not refer to the shelf life of this solution. This study evaluated, through the colorimetric titration technique and an analysis of dentin micro-hardness, the shelf life of 0.2% chitosan solution. MATERIALS AND METHODS: Thirty human canines were sectioned, and specimens were obtained from the second and third slices, from cemento-enamel junction to the apex. A 0.2% chitosan solution was prepared and distributed in 3 identical glass bottles (v1, v2, and v3) and 3 plastic bottles (p1, p2, and p3). At 0, 7, 15, 30, 45, 60, 90, 120, 150, and 180 days, the specimens were immersed in each solution for 5 minutes (n = 3 each). The chelating effect of the solution was assessed by micro-hardness and colorimetric analysis of the dentin specimens. 17% EDTA and distilled water were used as controls. Data were analyzed statistically by two-way and Tukey-Kramer multiple comparison (α = 0.05). RESULTS: There was no statistically significant difference among the solutions with respect to the study time (p = 0.113) and micro-hardness/time interaction (p = 0.329). Chitosan solutions and EDTA reduced the micro-hardness in a similar manner and differed significantly from the control group (p < 0.001). Chitosan solutions chelated calcium ions throughout the entire experiment. CONCLUSIONS: Regardless of the storage form, chitosan demonstrates a chelating property for a minimum period of 6 months.

Modulatory effect of iron chelators on adenosine deaminase activity and gene expression in Trichomonas vaginalis

Trichomonas vaginalis is a flagellate protozoan that parasitises the urogenital human tract and causes trichomoniasis. During the infection, the acquisition of nutrients, such as iron and purine and pyrimidine nucleosides, is essential for the survival of the parasite. The enzymes for purinergic signalling, including adenosine deaminase (ADA), which degrades adenosine to inosine, have been characterised in T. vaginalis. In the evaluation of the ADA profile in different T. vaginalisisolates treated with different iron sources or with limited iron availability, a decrease in activity and an increase in ADA gene expression after iron limitation by 2,2-bipyridyl and ferrozine chelators were observed. This supported the hypothesis that iron can modulate the activity of the enzymes involved in purinergic signalling. Under bovine serum limitation conditions, no significant differences were observed. The results obtained in this study allow for the assessment of important aspects of ADA and contribute to a better understanding of the purinergic system in T. vaginalis and the role of iron in establishing infection and parasite survival.

Facile synthesis of chelating bis ligands: spectroscopic, physicochemical and biological studies.

Seven bis-ligands of carbamides were synthesized and characterized on the basis of elemental analysis, Infrared spectroscopy, 1H NMR, mass spectra and UV-Visible studies. These bis-ligands were synthesized by condensation method, of acidic dichloride with 4-methoxyphenylcarbamide (4-MPC) in stoichiometric ratio of 1:2 respectively. It were found that, the behaviour of bis-ligands acting as chelating agents (chelators), therefore these were comparatively interpreted on the basis of physicochemical properties such as viscosity, surface tension, conductivity, pH and solubility. The antimicrobial activities of chelating ligands also have been studied. The results were revealing that, the activities of newly synthesized chelating ligands were found to be higher than its parent’s compound. The aromatic chelating compounds shows more activity in all physicochemical properties as compare to aliphatic chelators. The nanoparticle sizes of chelating ligands were significantly identified by scanning electron microscopy (SEM) and morphological result of each chelating compound were found totally different.

Time-dependent effects of chitosan on dentin structures

Complete debridement with smear layer removal are essential measures for achieving a successful outcome of root canal treatment. The aim of this study was to evaluate the effects of chitosan at different concentrations on the removal of the smear layer and on dentin structure after 3 and 5 min of application. Twelve recently extracted maxillary canine teeth were instrumented using the crown-down technique and irrigated with 1% sodium hypochlorite. The specimens were distributed according to the time and concentration of the final irrigating solution: G1: 0.1% chitosan for 3 min; G2: 0.2% chitosan for 3 min; G3: 0.37% chitosan for 3 min; G4: 0.1% chitosan for 5 min; G5: 0.2% chitosan for 5 min; G6: 0.37% chitosan for 5 min. All samples were prepared for SEM analysis. G1 exhibited removal of the smear layer, but not the smear plugs. G2 showed visible and open tubules with slight erosion of the peritubular dentin. Cleaning in G3 was similar to that in G2, however, the erosive effect was greater. There was expansion of the diameter of the tubules in G4; and in G5 and G6, there was severe erosion with deterioration of dentin surface. In conclusion, 0.2% chitosan for 3 min appeared to be efficient for removing the smear layer, causing little erosion of dentin.

Completo debridamento dos canais radiculares com a remoção da smear layer são medidas essenciais no sucesso do tratamento endodôntico. O objetivo deste estudo foi avaliar os efeitos da quitosana, em diferentes concentrações, na remoção da smear layer e na estrutura da dentina, após 3 e 5 min de aplicação. Doze dentes caninos superiores, recém extraídos, foram instrumentados pela técnica crown-down e irrigados com hipoclorito de sódio 1%. Os espécimes foram distribuídos em seis grupos conforme o tempo e a concentração da solução irrigante final: G1: quitosana 0,1% por 3 min; G2: quitosana 0,2% por 3 min; G3: quitosana 0,37% por 3 min; G4: quitosana 0,1% por 5 min; G5: quitosana 0,2% por 5 min; G6: quitosana 0,37% por 5 min. Todas as amostras foram preparadas para avaliação em MEV. Os resultados mostraram que o G1 apresentou remoção da smear layer, mas não da smear plug. O G2 mostrou túbulos visíveis e abertos com ligeira erosão da dentina peritubular. A limpeza no G3 foi semelhante à do G2, no entanto, o efeito erosivo foi maior. No G4 houve ampliação do diâmetro dos túbulos e no G5 e G6, severa erosão com deterioração da superfície dentinária. Concluiu-se que a quitosana 0,2% por 3 min foi eficiente na remoção da smear layer, ocasionando pequena erosão.

Arsenic and fluoride: Two major ground water pollutants.

Increasing human activities have modified the global cycle of heavy metals, non metals and metalloids. Both arsenic and fluoride are ubiquitous in the environment. Thousands of people are suffering from the toxic effects of arsenicals and fluorides in many countries all over the world. These two elements are recognized worldwide as the most serious inorganic contaminants in drinking water. Many studies have reported as regards to simple fluorosis and arsenicosis, but the knowledge of the joint action of these two elements is lacking and the results derived from previous studies were inconclusive. Contradictory results were reported in experimental studies in which different joint actions such as independent, synergistic and antagonistic effects were observed. This indicates that interaction mechanism of these two elements is considerable complicated and requires extensive studies. When two different types of toxicants are simultaneously going inside a human body they may function independently or can act as synergistic or antagonistic to one another. Thus there is an urge to resolve the question that how arsenic and fluoride act in condition of concomitant exposure. Although there have been reports in literature of individual toxicity of arsenic and fluoride however, there is very little known about the effects following the combined exposure to these toxicants. This review focused on recent developments in the research on the condition of individual exposure to arsenic and fluoride along with the recent updates of their combined exposure to better understand the joint action of these two toxicants.

Idiopathic environmental intolerances (IEI): From molecular epidemiology to molecular medicine.

Inherited or acquired impairment of xenobiotics metabolism is a postulated mechanism underlying environment-associated pathologies such as multiple chemical sensitivity, fibromyalgia, chronic fatigue syndrome, dental amalgam disease, and others, also collectively named idiopathic environmental intolerances (IEI). In view of the poor current knowledge of their etiology and pathogenesis, and the absence of recognised genetic and metabolic markers of the diseases. They are often considered “medically unexplained syndromes”,. These disabling conditions share the features of poly-symptomatic multi-organ syndromes, considered by part of the medical community to be aberrant responses triggered by exposure to low-dose organic and inorganic chemicals and metals, in concentrations far below average reference levels admitted for environmental toxicants. A genetic predisposition to altered biotransformation of environmental chemicals, drugs, and metals, and of endogenous low-molecular weight metabolites, caused by polymorphisms of genes coding for xenobiotic metabolizing enzymes, their receptors and transcription factors appears to be involved in the susceptibility to these environment-associated pathologies, along with epigenetic factors. Free radical/antioxidant homeostasis may also be heavily implicated, indirectly by affecting the regulation of xenobiotic metabolizing enzymes, and directly by causing increased levels of oxidative products, implicated in the chronic damage of cells and tissues, which is in part correlated with clinical symptoms. More systematic studies of molecular epidemiology, toxico- and pharmaco-genomics, elucidating the mechanisms of regulation, expression, induction, and activity of antioxidant/detoxifying enzymes, and the possible role of inflammatory mediators, promise a better understanding of this pathologically increased sensitivity to low-level chemical stimuli, and a solid basis for effective individualized antioxidant- and/or chelator-based treatments.

Protective action of deferiprone and deferoxamine in erythrocytes isolated from patients with B-thalassemias / Ação protetora de deferiprona e desferoxamina nos eritrócitos isolados de pacientes com B-talassemias

One of the most deleterious consequences of iron overload in thalassemia is the presence of non-transferrin bound iron (NTBI), a free radical that acts as a catalyst for free oxygen radicals, in particular for hydroxyl free radicals (OH.). These radicals oxidize both membrane lipids and proteins causing irreversible damage to biologically important molecules and cellular structures. Treatment with iron chelators has been important to improve survival of these individuals. The aim of this work was the study on the effects of deferoxamine (DFO) and deferiprone (DFP) on erythrocytes under the pro-oxidative action of TBHP isolated from normal individuals and patients with β-thalassemia. The in vitro action of deferoxamine and deferiprone on the oxidative metabolism of erythrocytes from β-thalassemic patients treated at the Centro de Hematologia e Hemoterapia do Paraná (HEMEPAR), Brazil, under the pro-oxidative action of TBHP was studied. Methemoglobin concentrations, reduced glutathione (GSH), hemolysis indexes and the enzyme activities of G6-PD and GR were determined. The oxidation indexes were higher in erythrocytes of β-thalassemic individuals than those from normal individuals. Treatment of the normal and β-thalassemic erythrocytes with DFO and/or DFP protected against the formation of GSH promoted by TBHP.

Uma das maiores consequências da sobrecarga do ferro na β-talassemia é a presença de ferro não ligado à transferrina (NTBI), um radical livre que age como um catalisador do radical livre do oxigênio, particularmente radical hidroxil (OH.). Estes radicais oxidam os lipídeos e as proteínas da membrana causando danos irreversíveis às moléculas biologicamente importantes e às estruturas celulares. O tratamento com quelantes do ferro é importante para a melhoria da sobrevivência destes indivíduos. O objetivo deste trabalho foi o estudo sobre o efeito da desferoxamina (DFO) e da deferiprona (DFP) em eritrócitos isolados de indivíduos normais e de pacientes com β-talassemias, sob a ação pró-oxidativa de TBHP. Neste trabalho foi estudada a ação in vitro da desferoxamina e o deferiprona no metabolismo oxidativo dos eritrócitos de pacientes β-talassêmicos atendidos no Centro de Hematologia e Hemoterapia do Paraná (Hemepar), Brasil, sob a ação pró-oxidativa de TBHP. Concentrações de metahemoglobina glutationa reduzida, índices de hemólises, atividades das enzimas G6PD e GR foram determinadas. Os índices de oxidação analisados foram maiores nos eritrócitos de indivíduos β-talassêmicos do que nos normais. Tratamentos dos eritrócitos normais e β-talassêmicos com DFO e/ou DFP protegem contra a oxidação de GSH promovida por TBHP.

Cellular Zn depletion by metal ion chelators (TPEN, DTPA and chelex resin) and its application to osteoblastic MC3T3-E1 cells

Trace mineral studies involving metal ion chelators have been conducted in investigating the response of gene and protein expressions of certain cell lines but a few had really focused on how these metal ion chelators could affect the availability of important trace minerals such as Zn, Mn, Fe and Cu. The aim of the present study was to investigate the availability of Zn for the treatment of MC3T3-E1 osteoblast-like cells and the availability of some trace minerals in the cell culture media components after using chelexing resin in the FBS and the addition of N,N,N',N'-tetrakis-(2-pyridylmethyl)ethylenediamine (TPEN, membrane-permeable chelator) and diethylenetriaminepentaacetic acid (DTPA, membrane-impermeable chelator) in the treatment medium. Components for the preparation of cell culture medium and Zn-treated medium have been tested for Zn, Mn, Fe and Cu contents by atomic absorption spectrophotometer or inductively coupled plasma spectrophotometer. Also, the expression of bone-related genes (ALP, Runx2, PTH-R, ProCOL I, OPN and OC) was measured on the cellular Zn depletion such as chelexing or TPEN treatment. Results have shown that using the chelexing resin in FBS would significantly decrease the available Zn (p<0.05) (39.4 +/- 1.5 micrometer vs 0.61 +/- 10.15 micrometer) and Mn (p<0.05) (0.74 +/- 0.01 micrometer vs 0.12 +/- 0.04 micrometer). However, levels of Fe and Cu in FBS were not changed by chelexing FBS. The use of TPEN and DTPA as Zn-chelators did not show significant difference on the final concentration of Zn in the treatment medium (0, 3, 6, 9, 12 micrometer) except for in the addition of higher 15 micrometer ZnCl2 which showed a significant increase of Zn level in DTPA-chelated treatment medium. Results have shown that both chelators gave the same pattern for the expression of the five bone-related genes between Zn- and Zn+, and TPEN-treated experiments, compared to chelex-treated experiment, showed lower bone-related gene expression, which may imply that TPEN would be a stronger chelator than chelex resin. This study showed that TPEN would be a stronger chelator compared to DTPA or chelex resin and TPEN and chelex resin exerted cellular zinc depletion to be enough for cell study for Zn depletion.

Effects of Chelators on Liver Cadmium Contents in Chronic Cadmium Intoxication Rats / 대한간학회지

BACKGROUND/AIMS: The heavy metals like cadmium (Cd) are neither destroyed nor produced in human body and may infiltrated into air, water, soil, food, human body and redistributed by biological and geographical circulation. With advent of recent industrialization detrimental heavy metal poisoning in human body is increased by industrial pollution. We aimed to establish the relative abilities of chelators to mobilized liver cadmium contents in chronic cadmium intoxication rats. METHODS: Sprague-Dawley albino male rats weighing 200 to 250 mg were used. All animals were loaded with 3 intraperitoneal injections of cadmium chloride (1.5 mg/kg) given at % hourly interval. Intraperitoneal injection of chelators commenced 1 week after the last loading injection and continued every 72 hour for a total of 10 injections. Chelators were given at a level of 1 mmole/kg (except 0.01 mmol/kg of BAL). The chelators used in present experiment are 1,2-diaminocyclohexane tetra acetate (CDTA), disodium calcium ethylene diamine tetra acetate (EDTA), sodium 2.3-dimer capto propane sulfonate (DMPS), sodium di ethyl dithio carbamate (DDTC), dimercapto succinate (DMSA), 2,3-dimer capto propanol (BAL), diethylene triamine penta acetate (DTPA), triethylene tetr amine hexa acetate (TTHA), D-penicillamine(DPA), Nacetyl penicillamine (NAPA). RESULTS: 1) The residual liver cadmium content was reduced in rats administered DPA, EDTA, NAPA, CDTA, DDTC and DMSA (32%, 23%, 19%, 17%, 16% and 15% respectively) compared with control group. 2) The residual kidney cadmium content was reduced in rats administered DPA, DDTC, CDTA and EDTA (33%, 21%, 18% and 17% respectively) 3) The summation of residual cadmium content in liver and kidney was reduced in rats administered DPA, EDTA, DDTC and CDTA (33%, 20%, 18% and 17% respectively) compared with control group. CONCULUSIONS: We suggested that DPA, EDTA, CDTA and DDTC might have protective role against the toxic effects of cadmium.