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Iron Concentration (iron + concentration)
Kinds of Iron Concentration Selected AbstractsSerum Zinc, Chromium, and Iron Concentrations in Dogs with Lymphoma and OsteosarcomaJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 6 2001Kathy J. Kazmierski We compared serum concentrations of zinc, chromium, and iron in dogs with cancer to those of normal dogs. Dogs with lymphoma (n = 50) and osteosarcoma (n = 52) were evaluated. Dogs with lymphoma had significantly lower (P= .0028) mean serum zinc concentrations (mean ± SD; 1.0 ± 0.3 mg/L) when compared to normal dogs (1.2 ± 0.4 mg/L). Dogs with osteosarcoma also had lower mean serum zinc concentrations (1.1 ± 0.4 mg/L), but this difference was not significant (P= .075). Serum chromium concentrations were significantly lower in dogs with lymphoma (2.6 ± 2.6 ,g/L, P= .0007) and osteosarcoma (2.4 ± 3.1 ,g/L, P= .0001) compared to normal dogs (4.7 ± 2.8 ,g/L). Serum iron concentrations and total iron-binding capacity were significantly lower in dogs with lymphoma (110.8 ± 56.7 ,g/dL, P < .0001, and 236.6 ± 45.6 ,g/dL, P < .0001, respectively) and osteosarcoma (99.6 ± 49.3 ,g/dL, P < .0001, and 245.0 ± 43.8 ,g/dL, P= .0011, respectively) when compared to normal dogs (175.1 ± 56.7 ,g/dL and 277.1 ± 47.4 ,g/dL). Mean ferritin concentration was significantly higher in dogs with lymphoma (1291.7 ± 63.0 ,g/L) than in normal dogs (805.8 ± 291.1 ,g/L, P < .0001) and dogs with osteosarcoma (826.5 ± 309.2 ,g/L, P < .0001). Further investigation is needed to explore the clinical significance of these mineral abnormalities in dogs with cancer. [source] Variable-field relaxometry of iron-containing human tissues: a preliminary studyCONTRAST MEDIA & MOLECULAR IMAGING, Issue 4 2009Aline Hocq Abstract Excess iron is found in brain nuclei from neurodegenerative patients (with Parkinson's, Alzheimer's and Huntington's diseases) and also in the liver and spleen of cirrhosis, hemochromatosis and thalassaemia patients. Ferritin, the iron-storing protein of mammals, is known to darken T2 -weighted MR images. Understanding NMR tissue behavior may make it possible to detect those diseases, to follow their evolution and finally to establish a protocol for non-invasive measurement of an organ's iron content using MRI methods. In this preliminary work, the MR relaxation properties of embalmed iron-containing tissues were studied as well as their potential correlation with the iron content of these tissues. Relaxometric measurements (T1 and T2) of embalmed samples of brain nuclei (caudate nucleus, dentate nucleus, globus pallidus, putamen, red nucleus and substantia nigra), liver and spleen from six donors were made at different magnetic fields (0.00023,14 T). The influence of the inter-echo time on transverse relaxation was also studied. Moreover, iron content of tissues was determined by inductively coupled plasma atomic emission spectroscopy. In brain nuclei, 1/T2 increases quadratically with the field and depends on the inter-echo time in CPMG sequences at high fields, both features compatible with an outer sphere relaxation theory. In liver and spleen, 1/T2 increases linearly with the field and depends on the inter-echo time at all fields. In our study, a correlation between 1/T2 and iron concentration is observed. Explaining the relaxation mechanism for these tissues is likely to require a combination of several models. The value of 1/T2 at high field could be used to evaluate iron accumulation in vivo. In the future, confirmation of those features is expected to be achieved from measurements of fresh (not embalmed) human tissues. Copyright © 2009 John Wiley & Sons, Ltd. [source] Oxidation of ferrous iron by Thiobacillus ferrooxidans in a full-scale rotating biological contactorENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 4 2001L. Nikolov The performance of a full-scale rotating biological contactor used for the oxidation of ferrous iron by Thiobacillus ferrooxidans in drainage waters was studied. It has been shown that high volumetric rates, up to 2.5 g/Lh can be obtained. We also examined the effects of input ferrous iron concentration and liquid retention time on reactor performance. It has been shown that when the input iron concentration increased, volumetric reaction rate increased while substrate conversion decreased. In general, the rotating biological contractor is a promising tool for the biological treatment of acid mine drainage containing ferrous iron. [source] The relationship between local and regional diatom richness is mediated by the local and regional environmentGLOBAL ECOLOGY, Issue 3 2009Sophia I. Passy ABSTRACT Aim, In this continental study, species richness at local (LSR) and regional (RSR) scales was correlated and examined as a function of stream (local) and watershed (regional) environment in an effort to elucidate what factors control diatom biodiversity across scales. Location, Conterminous United States. Methods, Data on diatom richness, stream conditions and watershed properties were generated by the US Geological Survey. In the present investigation, RSR was estimated as the total diatom richness in a hydrologic study unit and, together with stream and watershed characteristics, was included in stepwise multiple regressions of LSR. The unique and shared contributions of RSR, stream and watershed environment to the explained variance in LSR were determined by variance partitioning. RSR was regressed against stream and basin features averaged per study unit. Results, LSR responded most strongly to variability in stream manganese concentration and RSR. Other predictors included stream discharge and iron concentration, soil organic matter content and fertilization, and proportions of open water, barren land and forest in the watershed. Variance partitioning revealed that RSR had the lowest independent contribution to explained variance in LSR. Multiple regressions identified average stream iron concentration as the most important predictor of RSR. Main conclusions, Local micronutrient concentration was the major predictor of LSR, followed by RSR. Since average micronutrient supply in the region was the chief determinant of RSR, it is proposed that micronutrients had both a direct effect on LSR and an indirect effect through RSR. The same argument is extended to watershed features with an impact on stream trophic status, because of their substantial contributions to the explained variance in both LSR and RSR. Considering that the major proportion of LSR variance explained by RSR originated from the covariance of RSR with stream and watershed properties, it is concluded that the LSR,RSR relationship was mediated by the local and regional environment. [source] Oxidative damage is increased in human liver tissue adjacent to hepatocellular carcinomaHEPATOLOGY, Issue 6 2004Christoph Jüngst Accumulation of genetic alterations in hepatocarcinogenesis is closely associated with chronic inflammatory liver disease. 8-oxo-2,-deoxyguanosine (8-oxo-dG), the major promutagenic DNA adduct caused by reactive oxygen species (ROS), leads to G:C , T:A transversions. These lesions can be enzymatically repaired mainly by human MutT homolog 1 (hMTH1), human 8-oxo-guanine DNA glycosylase (hOGG1) and human MutY homolog (hMYH). The aim of this study was to evaluate the extent of oxidative damage and its dependence on the cellular antioxidative capacity and the expression of specific DNA repair enzymes in tumor (tu) and corresponding adjacent nontumor (ntu) liver tissue of 23 patients with histologically confirmed hepatocellular carcinoma. 8-oxo-dG levels, as detected by high-pressure liquid chromatography with electrochemical detection, were significantly (P = .003) elevated in ntu tissue (median, 129 fmol/,g DNA) as compared to tu tissue (median, 52 fmol/,g DNA), and were closely associated with inflammatory infiltration. In ntu tissue, the hepatic iron concentration and malondialdehyde levels were significantly (P = .001) higher as compared to tu tissue. Glutathione content, glutathione peroxidase activity and manganese superoxide dismutase messenger RNA (mRNA) expression did not show statistical differences between ntu and tu tissue. Real-time reverse transcription polymerase chain reaction revealed in tu tissue significantly (P = .014) higher hMTH1 mRNA expression compared to ntu tissue. In contrast, hMYH mRNA expression was significantly (P < .05) higher in ntu tissue. No difference in hOGG1 mRNA expression was seen between tu and ntu. In conclusion, these data suggest that ROS generated by chronic inflammation contribute to human hepatocarcinogenesis. The role of DNA repair enzymes appears to be of reactive rather than causative manner. (HEPATOLOGY 2004;39:1663,1672.) [source] Evaluating the transport and removal of chromate using pyrite and biotite columnsHYDROLOGICAL PROCESSES, Issue 14 2007Chul-Min Chon Abstract To remove chromate from a wastewater, a porous permeable reactive barrier system (PRBS), using pyrite and biotite, was adapted. This study included bench-scale column experiments to evaluate the efficiency of the PRBS and investigate the reaction process. The total chromium concentration of the effluent from the biotite and pyrite columns reached the influent concentration of 0·10 mM after passing through more than 150 pore volumes (PVs) and 27 PVs respectively, and remained constant thereafter. The CrVI concentration in the effluent from the biotite column became constant at about 0·08 mM, accounting for approximately 80% of the influent concentration, after passing through 200 PVs. Moreover, in the pyrite column, the CrVI concentration remained at about 0·01 mM, 10% of the input level, after passing through 116 PVs. This shows that both columns maintained their levels of chromate reduction once the CrVI breakthrough curves (BTCs) had reached the steady state, though the steady-state output concentration of total chromium had reached the influent level. The variances of the iron concentration closely followed those of the chromium. The observed data for both columns were fitted to the predicted BTCs calculated by CXTFIT, a program for estimating the solute transport parameters from experimental data. The degradation coefficient µ of the total chromium BTCs for both columns was zero, suggesting the mechanisms for the removal of chromate limit the µ of the CrVI BTCs. The CrVI degradation of the pyrite column (6·60) was much greater than that of the biotite column (0·27). In addition, the CrVI retardation coefficient R of the pyrite column (253) was also larger than that of the biotite column (125). The R values for the total chromium BTCs from both columns were smaller than those of the CrVI BTC. Whereas the total chromium BTC for the pyrite column showed little retardation (1·5), the biotite column showed considerable retardation (80). The results for the 900 °C heat-treated biotite column were analogous to those of the control column (quartz sand). This suggests that the heat-treated biotite played no role in the retardation and removal of hexavalent chromium. The parameters of the heat-treated biotite were calculated to an R of 1·2 and µ of 0·01, and these values confirmed quantitatively that the heated biotite had little effect on the transport of CrVI. These solute transport parameters, calculated by CXTFIT from the data obtained from the column tests, can provide quantitative information for the evaluation of bench- or field-scale columns as a removal technology for CrVI in wastewater or contaminated groundwater. Copyright © 2006 John Wiley & Sons, Ltd. [source] Iron-induced oxidative stress up-regulates calreticulin levels in intestinal epithelial (Caco-2) cellsJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 4 2001Marco T. Núñez Abstract Calreticulin, a molecular chaperone involved in the folding of endoplasmic reticulum synthesized proteins, is also a shock protein induced by heat, food deprivation, and chemical stress. Mobilferrin, a cytosolic isoform of calreticulin, has been proposed to be an iron carrier for iron recently incoming into intestinal cells. To test the hypothesis that iron could affect calreticulin expression, we investigated the possible associations of calreticulin with iron metabolism. To that end, using Caco-2 cells as a model of intestinal epithelium, the mass and mRNA levels of calreticulin were evaluated as a function of the iron concentration in the culture media. Increasing the iron content in the culture from 1 to 20 ,M produced an increase in calreticulin mRNA and a two-fold increase in calreticulin. Increasing iron also induced oxidative damage to proteins, as assessed by the formation of 4-hydroxy-2-nonenal adducts. Co-culture of cells with the antioxidants quercetin, dimethyltiourea and N-acetyl cysteine abolished both the iron-induced oxidative damage and the iron-induced increase in calreticulin. We postulate that the iron-induced expression of calreticulin is part of the cellular response to oxidative stress generated by iron. J. Cell. Biochem. 82: 660,665, 2001. © 2001 Wiley-Liss, Inc. [source] Serum amino-terminal propeptide of type III procollagen and 7S domain of type IV collagen correlate with hepatic iron concentration in patients with chronic hepatitis C following ,-interferon therapyJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 2 2001Ichiro Shimizu Abstract Background: It has been reported that chronic infection with hepatitis C virus is associated with excess iron deposits in the liver of subjects who are neither alcoholics nor recipients of blood transfusions. However, little is known about the relationship between hepatic iron concentration (HIC) and the serum levels of hepatic fibrogenesis markers, which were caused by interferon therapy for chronic hepatitis C. Therefore, changes in the serum amino-terminal propeptide of type III procollagen (P-III-P) and the 7S domain of type IV collagen (7S-IV) in 16 patients treated with ,-interferon (IFN-,) were studied, and their HIC and histological assessment evaluated. Hepatic iron concentrations were measured by using liver biopsy specimens obtained before and 6 months after the cessation of treatment. Methods and Results: Eight subjects (50%) who had normal alanine transaminase levels at 6 months after therapy showed significantly lowered HIC, and attenuated hepatic iron staining with decreased serum levels of P-III-P and 7S-IV compared to the remaining subjects. The HIC was significantly correlated with the serum levels of P-III-P and 7S-IV in all subjects. Conclusions: These findings suggest that IFN-, treatment may decrease stimuli for fibrogenesis, at least in part, by reducing the hepatic iron deposition in patients with chronic hepatitis C. [source] Rat brain iron concentration is lower following perinatal copper deficiencyJOURNAL OF NEUROCHEMISTRY, Issue 3 2005Joseph R. Prohaska Abstract Experiments performed with Holtzman rats demonstrated that brain iron (Fe) was lower by postnatal day 13 (P13) in pups born and nursed by dams that began copper-deficient (,Cu) treatment at embryonic day 7. Transcardial perfusion of P24,P26 males and females to remove blood Fe contamination revealed that brain Fe was still 20% lower in ,Cu than +Cu rats. Estimated blood content of brain for ,Cu rats was greater than for +Cu rats; for all groups, values ranged between 0.43 and 1.03%. Using group-specific data and regression analyses, r = 0.99, relating blood Fe to hemoglobin, brain Fe in non-perfused rats in a replicate study was lower by 33% at P13 and 39% at P24 in ,Cu rats. Brain extracts from these rats and from P50 rats from a post-weaning model were compared by immunobloting for transferrin receptor (TfR1). P24 brain ,Cu/+Cu TfR1 was 3.08, suggesting that brains of ,Cu rats were indeed Fe deficient. This ratio in P13 rats was 1.44, p < 0.05. No change in P50 ,Cu rat brain TfR1 or Fe content was detected despite a 50% reduction in plasma Fe. The results suggest that brain Fe accumulation depends on adequate Cu nutriture during perinatal development. [source] Synthesis and stability of iron nanoparticles for lunar environment studiesMETEORITICS & PLANETARY SCIENCE, Issue 6 2010Ching-Cheh HUNG However, unlike the true lunar dust, today's simulants do not contain nanophase iron. Two different processes have been developed to fabricate nanophase iron to be used as part of a lunar dust simulant. (1) The first is to sequentially treat a mixture of ferric chloride, fluorinated carbon, and soda lime glass beads at about 300 °C in nitrogen, at room temperature in air, and then at 1050 °C in nitrogen. The product includes glass beads that are gray in color, can be attracted by a magnet, and contains ,-iron nanoparticles (which seem to slowly lose their lattice structure in ambient air during a period of 12 months). This product may have some similarity to the lunar glassy agglutinate, which contains FeO. (2) The second is to heat a mixture of carbon black and a lunar simulant (a mixed metal oxide that includes iron oxide) at 1050 °C in nitrogen. This process simulates lunar dust reactions with the carbon in a micrometeorite at the time of impact. The product contains a chemically modified simulant that can be attracted by a magnet and has a surface layer whose iron concentration increased during the reaction. The iron was found to be ,-iron and Fe3O4 nanoparticles, which appear to grow after the fabrication process. This growth became undetectable after 6 months of ambient air storage, but may last for several years or longer. [source] Compositional and lithological diversity among brecciated lunar meteorites of intermediate iron concentrationMETEORITICS & PLANETARY SCIENCE, Issue 9 2009Randy L. Korotev Most have iron concentrations intermediate to those of the numerous feldspathic lunar meteorites (3,7% FeO) and the basaltic lunar meteorites (17,23% FeO). All but one are polymict breccias. Some, as implied by their intermediate composition, are mainly mixtures of brecciated anorthosite and mare basalt, with low concentrations of incompatible elements such as Sm (1,3 ,g/g). These breccias likely originate from points on the Moon where mare basalt has mixed with material of the FHT (Feldspathic Highlands Terrane). Others, however, are not anorthosite-basalt mixtures. Three (17,75 ,/g Sm) consist mainly of nonmare mafic material from the nearside PKT (Procellarum KREEP Terrane) and a few are ternary mixtures of material from the FHT, PKT, and maria. Some contain mafic, nonmare lithologies like anorthositic norites, norites, gabbronorites, and troctolite. These breccias are largely unlike breccias of the Apollo collection in that they are poor in Sm as well as highly feldspathic anorthosite such as that common at the Apollo 16 site. Several have high Th/Sm compared to Apollo breccias. Dhofar 961, which is olivine gabbronoritic and moderately rich in Sm, has lower Eu/Sm than Apollo samples of similar Sm concentration. This difference indicates that the carrier of rare earth elements is not KREEP, as known from the Apollo missions. On the basis of our present knowledge from remote sensing, among lunar meteorites Dhofar 961 is the one most likely to have originated from South Pole-Aitken basin on the lunar far side. [source] New local hyperthermia using dextran magnetite complex (DM) for oral cavity: experimental study in normal hamster tongueORAL DISEASES, Issue 3 2001S Wada The possibility of dextran magnetite complex (DM) as a new hyperthermic material was examined in this study. DM suspension of 56 mg ml ,1 iron concentration was locally injected into the normal tongue of golden hamster. DM injected tongues were heated by 500 kHz alternating current (AC) magnetic field and its serial changes in temperature were recorded at 30-s intervals. The temperature of DM injected tongue was maintained at about 43.0,45.0°C for 30 min by changing the AC magnetic field intensity. While temperature elevations of the contralateral tongue and the rectum were only of minor degree. In experiment on the extent of heating area, there was correlation between volume of black stain area and amount of the injected DM suspension (Y =,18.1 + 1.94X, r= 0.931, P < 0.0001, n= 9). Histological examination after heating revealed brown uniform DM accumulation in the connective tissue between fibers of the tongue muscle. Except for vascular dilatations, no tissue damage was seen in the heated tongue. Thus, DM which has the possibility of selective and uniform heating in local hyperthermia might be useful for oral cancer therapy. [source] Transient elastography in the assessment of liver fibrosis in adult thalassemia patients,AMERICAN JOURNAL OF HEMATOLOGY, Issue 8 2010Mirella Fraquelli Transient elastography (TE) is a valuable noninvasive technique of measuring liver stiffness and a reliable tool for predicting hepatic fibrosis in patients with chronic liver disease. The role of TE in patients with ,-thalassemia has not been extensively investigated. The present study aimed to evaluate the role of TE in the assessment of hepatic fibrosis in 115 adult patients with ,-thalassemia major (TM) (#59) or intermedia (TI) (#56). TE was performed according to current practice. Histologic data were obtained in 14 cases. Liver iron concentration was assessed by atomic absorption spectrometry and T2* magnetic resonance. In patients with TM, the proportion of anti-HCV positive viremic patients, median serum ferritin levels, and TE values were significantly higher than in TI. In the group of 14 patients who underwent liver biopsy, a significant positive correlation was observed between liver stiffness and fibrosis stage (r = 0.73, P = 0.003). Severe fibrosis is diagnosed with a sensitivity of 60% and a specificity of 89%, whereas cirrhosis is detected with a sensitivity of 100% and a specificity of 92%. At multivariate analysis, the variables independently associated with TE were ALT, GGT, and bilirubin levels in both groups and, in patients with TM, HCV RNA positivity. In ,-thalassemia patients, TE is a reliable tool for assessing liver fibrosis even if the influence of iron overload has to be clarified. Am. J. Hematol. 85:564,568, 2010. © 2010 Wiley-Liss, Inc. [source] Severe iron overload in Blackfan-Diamond anemia: A case-control study,AMERICAN JOURNAL OF HEMATOLOGY, Issue 11 2009Simona Roggero Chronic iron overload is a serious complication in transfusion-dependent patients. Few studies have addressed this issue in Diamond-Blackfan anemia (DBA). We describe a retrospective analysis of iron overload, and its related complications in 31 transfusion-dependent Italian DBA patients whose records included one or more evaluation of liver iron concentration (LIC) by means of noninvasive magnetic liver susceptometry with a superconductive quantum interference device (SQUID). This cohort is also matched with a group of transfusion-dependent ,-thalassemia major patients to look for differences. A severe iron overload was observed in 54% patients, especially among those inadequately chelated. The DBA patients displayed a significantly higher LIC than the regularly chelated ,-thalassemics. This difference may have been attributable to nonoptimal chelation (late onset, type, dose, prescription, and compliance), or an unknown biological mechanism that lead to an early severe iron overload. We therefore suggest that all transfusion patients should have an accurate record of their iron intake, a regular monitoring of iron overload, in order to start chelation when a critical transfusion load is reached, and to test the efficacy/compliance of chelation treatment. Physicians taking care of transfusion-dependent DBA patients must be concerned about the frequent and early complications such as cardiac toxicity. Am. J. Hematol., 2009. © 2009 Wiley-Liss, Inc. [source] Deferasirox removes cardiac iron and attenuates oxidative stress in the iron-overloaded gerbil,AMERICAN JOURNAL OF HEMATOLOGY, Issue 9 2009Rabaa M. Al-Rousan Iron-induced cardiovascular disease is the leading cause of death in iron-overloaded patients. Deferasirox is a novel, once daily oral iron chelator that was recently approved for the treatment of transfusional iron overload. Here, we investigate whether deferasirox is capable of removing cardiac iron and improving iron-induced pathogenesis of the heart using the iron overload gerbil model. Animals were randomly divided into three groups: control, iron overload, and iron overload + deferasirox treatment. Iron-dextran was given 100 mg/kg per 5 days i.p for 10 weeks. Deferasirox treatment was taken post iron loading and was given at 100 mg/kg/day p.o for 1 or 3 months. Cardiac iron concentration was determined by inductively coupled plasma atomic emission spectroscopy. Compared with the untreated group, deferasirox treatment for 1 and 3 months decreased cardiac iron concentration 17.1% (P = 0.159) and 23.5% (P < 0.05), respectively. These treatment-associated reductions in cardiac iron were paralleled by decreases in tissue ferritin expression of 20% and 38% at 1 and 3 months, respectively (P < 0.05). Using oxyblot analysis and hydroethidine fluorescence, we showed that deferasirox significantly reduces cardiac protein oxidation and superoxide abundance by 36 and 47.1%, respectively (P < 0.05). Iron-induced increase in oxidative stress was also associated with increased phosphorylation of ERK-, p38-, and JNK-mitogen-activated protein kinase (MAPK). Interestingly, deferasirox treatment significantly diminished the phosphorylation of all three MAPK subfamilies. These results suggest that deferasirox may confer a cardioprotective effect against iron induced injury. Am. J. Hematol. 2009. © 2009 Wiley-Liss, Inc. [source] Liver biopsy results in patients with sickle cell disease on chronic transfusions: Poor correlation with ferritin levelsPEDIATRIC BLOOD & CANCER, Issue 1 2008Lina B. Karam MD Abstract Background: Chronic transfusions are effective in preventing stroke and other complications of sickle cell disease. The aim of this study was to determine whether serum ferritin levels correlated with liver iron content in sickle cell patients on chronic transfusion. Procedure: Forty-four liver biopsy specimens from 38 patients with homozygous sickle cell anemia (HbSS) and one patient with sickle thalassemia receiving chronic transfusions were studied. Five patients underwent a second liver biopsy for follow up. Three ferritin measurements were used to calculate a mean for each patient. The association between serum ferritin levels and liver iron quantitation was measured using the Spearman rank correlation, and sensitivity and specificity were determined for selected threshold values of serum ferritin. Results: Serum ferritin levels ranged from 515 to 6076 ng/ml, liver iron concentration ranged from 1.8 to 67.97 mg/g dry weight. The amount of iron per gram liver dry weight was moderately correlated with serum ferritin values (r,=,0.46). The correlation of duration of transfusion with serum ferritin (r,=,0.40) and with liver iron content (r,=,0.41) also indicated moderate correlation. Liver biopsy results led to changes in the management after 29/44 (66%) of the biopsies. Serum ferritin ,2500 ng/ml predicted high liver iron content (,7 mg/g), with a sensitivity of 62.5% and a specificity of 77.8%. Conclusion: We found a poor correlation between serum ferritin levels and liver iron content (LIC). Despite being on chelation therapy, many patients on chronic transfusion had high levels of liver iron. Measurement of LIC is highly recommended in these patients. Pediatr Blood Cancer 2008;50:62,65. © 2007 Wiley-Liss, Inc. [source] Serum ferritin underestimates liver iron concentration in transfusion independent thalassemia patients as compared to regularly transfused thalassemia and sickle cell patientsPEDIATRIC BLOOD & CANCER, Issue 3 2007Zahra Pakbaz MD Abstract Serum ferritin (SF) and liver iron concentration (LIC), as measured by SQUID biosusceptometry, were assessed in a convenience sample of transfusion independent thalassemia patients (nTx-Thal, n,=,26), regularly transfused thalassemia (Tx-Thal, n,=,89), or sickle cell patients (SCD, n,=,45) to investigate the severity of iron overload and the relationship between SF and LIC in nTx-Thal compared to SCD and Tx-Thal. SF correlated with LIC (RS,=,0.53, P,<,0.001), but was found to be a poor predictor for LIC. SF was significantly lower (P,<,0.001) in nTx-Thal patients than in other groups, despite similar LIC values. The SF-to-LIC ratio was significantly lower in nTx-Thal compared to Tx-Thal and SCD patients (median of 0.32, 0.87, and 1.2, respectively: P,<,0.001). Due to underestimation of LIC by ferritin levels, chelation treatment may be delayed or misdirected in patients with thalassemia intermedia. Pediatr Blood Cancer 2007;49:329,332. © 2007 Wiley-Liss, Inc. [source] Patterns of hepatic iron distribution in patients with chronically transfused thalassemia and sickle cell disease,AMERICAN JOURNAL OF HEMATOLOGY, Issue 8 2009Nilesh R. Ghugre Patients with sickle cell disease (SCD) appear to be at lower risk of endocrinopathies and cardiac dysfunction than those with thalassemia major (TM). Circulating redox active iron is lower in these patients, possibly due to increased systemic inflammation and circulating cytokines. Hepcidin synthesis is upregulated during chronic inflammation, reducing intestinal iron absorption and promoting retention of iron in the reticuloendothelial cells. Hence, we hypothesized that livers of patients with SCD would exhibit greater iron deposition in sinusoidal spaces relative to hepatocytes and less in portal tracts when compared to patients with TM. To test this hypothesis, iron scoring analysis was performed on 70 clinically indicated liver biopsy specimens from children and young adults with the two syndromes. Sinusoidal scores were lower in around 1 of 4 patients with TM but the relative iron loading in hepatocytes, and portal tracts was identical in both diseases. Sinusoidal iron burdens saturated at low hepatic iron concentration (HIC) while hepatocyte and portal iron depots increased proportionally to HIC. Liver fibrosis was increased in patients with TM regardless of their chronic hepatitis status. Overall, liver iron distribution was relatively insensitive to differences in disease type and to the presence or absence of hepatitis. Am. J. Hematol., 2009. © 2009 Wiley-Liss, Inc. [source] Photoluminescence and Hall studies of GaN:Fe and (Ga,Fe)N:Mg layersPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 1 2007M. Wegscheider Abstract Temperature dependent photoluminescence (PL) in the ultraviolet (UV) regime and Hall measurements at room temperature have been performed on Metal-Organic-Chemical-Vapour-Deposition (MOCVD) grown GaN:Fe and (Ga,Fe)N:Mg layers. PL measurements were employed in order to study the dopants' influence on the near-band edge excitonic emission and their tendency to provoke the formation and suppression of defects or incorporation of impurities. For their identification and for the understanding of the PL spectra the evaluation of the free carrier concentrations via Hall measurements were necessary. Depending on the iron concentration of the (Ga,Fe)N layers, the near-band edge emission goes through two different stages: at low Fe-concentration no excitonic emission can be seen whereas with higher doping levels, excitonic features develop. The (Ga,Fe)N films exhibit n-type behaviour. The Mg codoped samples show strong Mg and defect related luminescence bands, whose occurrence and intensity also strongly depends on whether high or low Fe concentration is present. The (Ga,Fe)N:Mg layers were semi insulating. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Formation of Boron-doped region using spin-on dopant: investigation on the impact of metallic impuritiesPROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 5 2008J. Jourdan Abstract Investigation on the electrical properties of p+ -doped regions formed by spin-on-dopant (SOD) technique was achieved. Using this technique, boron-diffused regions were formed on both p-type and n-type float zone wafers. Homogeneous sheet resistances were obtained for both types of wafers. Bulk properties were investigated by measuring effective carrier lifetime. An iron contamination was observed after the boron diffusion step and interstitial iron concentrations were deduced from lifetime measurements. More investigations proved that the iron was initially present within the SOD film. A phosphorus diffusion allows to remove this bulk contamination, leading to an improvement of effective lifetime values. Nevertheless, the corresponding emitter saturation current density was estimated on n-type wafers and presented a high value. It is likely that this poor electrical quality is the consequence of a high iron concentration which remains in the diffused region. Some possibilities are suggested to avoid or to limit this contamination. Copyright © 2008 John Wiley & Sons, Ltd. [source] Hematologic iron analyte values as an indicator of hepatic hemosiderosis in callitrichidaeAMERICAN JOURNAL OF PRIMATOLOGY, Issue 7 2008Kristine M. Smith Abstract Hepatic hemosiderosis is one of the most common postmortem findings in captive callitrichid species. Noninvasive evaluation of hematologic iron analytes has been used to diagnose hepatic iron storage disease in humans, lemurs, and bats. This study evaluated the relationship between hematologic iron analyte values (iron, ferritin, total iron binding capacity, and percent transferrin saturation) and hepatic hemosiderosis in callitrichids at the Wildlife Conservation Society's Central Park and Bronx Zoos. Results revealed that both ferritin and percent transferrin saturation levels had strong positive correlations with hepatic iron concentration (P<0.001, r=0.77, n=20; P<0.001, r=0.85, n=10, respectively). Serum iron levels positively correlated with hepatic iron concentration (P=0.06, r=0.56, n=11), but this finding was not significant. Serum total iron binding capacity did not significantly correlate with hepatic iron concentration (P=0.47, r=0.25, n=10). Both ferritin and hepatic iron concentration positively correlated with severity of hepatic iron deposition on histology (P<0.05, r=0.49, n=21; P<0.001, r=0.67, n=21, respectively). This study suggests that ferritin, serum iron concentration, and percent transferrin saturation are convenient, noninvasive, antemortem methods for assessing severity of hemosiderosis in callitrichids. Am. J. Primatol. 70:629,633, 2008. © 2008 Wiley-Liss, Inc. [source] Complex responses to culture conditions in Pseudomonas syringae pv. tomato DC3000 continuous cultures: The role of iron in cell growth and virulence factor inductionBIOTECHNOLOGY & BIOENGINEERING, Issue 5 2010Beum Jun Kim Abstract The growth of a model plant pathogen, Pseudomonas syringae pv. tomato DC3000, was investigated using a chemostat culture system to examine environmentally regulated responses. Using minimal medium with iron as the limiting nutrient, four different types of responses were obtained in a customized continuous culture system: (1) stable steady state, (2) damped oscillation, (3) normal washout due to high dilution rates exceeding the maximum growth rate, and (4) washout at low dilution rates due to negative growth rates. The type of response was determined by a combination of initial cell mass and dilution rate. Stable steady states were obtained with dilution rates ranging from 0.059 to 0.086,h,1 with an initial cell mass of less than 0.6,OD600. Damped oscillations and negative growth rates are unusual observations for bacterial systems. We have observed these responses at values of initial cell mass of 0.9,OD600 or higher, or at low dilution rates (<0.05,h,1) irrespectively of initial cell mass. This response suggests complex dynamics including the possibility of multiple steady states. Iron, which was reported earlier as a growth limiting nutrient in a widely used minimal medium, enhances both growth and virulence factor induction in iron-supplemented cultures compared to unsupplemented controls. Intracellular iron concentration is correlated to the early induction (6,h) of virulence factors in both batch and chemostat cultures. A reduction in aconitase activity (a TCA cycle enzyme) and ATP levels in iron-limited chemostat cultures was observed compared to iron-supplemented chemostat cultures, indicating that iron affects central metabolic pathways. We conclude that DC3000 cultures are particularly dependent on the environment and iron is likely a key nutrient in determining physiology. Biotechnol. Bioeng. 2010;105: 955,964. © 2009 Wiley Periodicals, Inc. [source] Noninvasive assessment of liver fibrosis in thalassaemia major patients by transient elastography (TE) , lack of interference by iron depositionBRITISH JOURNAL OF HAEMATOLOGY, Issue 3 2010Vito Di Marco Summary The correlation between liver stiffness, measured by transient elastography, liver fibrosis, using the histological METAVIR score, and iron overload, measured by atomic absorption spectrometry was evaluated in 56 homozygous-,-thalassaemics. Liver stiffness increased proportionally to liver fibrosis staging (r = 0·70; P > 0·001) independently of liver iron concentration (r = 0·01; P = 0·932). The area under the receiver-operating characteristic curve for prediction of cirrhosis was 0·997 (95% confidence interval [CI]: 0·925,1·000) with cut-off of 13 kPa with 100% sensitivity (95% CI: 69·0,100·0) and 95% specificity (95% CI: 84·2,99·3). Transient elastography is a reliable non-invasive tool for diagnosing advanced liver fibrosis in homozygous-,-thalassaemics, regardless of the degree of iron overload. [source] Laboratory to field validation in an integrative assessment of an acid mine drainage,impacted watershedENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2000David J. Soucek Abstract An integrative assessment was conducted in the Puckett's Creek watershed of southwestern Virginia, USA, to investigate the environmental impacts of acid mine drainage (AMD) inputs. Twenty-one sampling stations were categorized into groups based on five degrees of AMD input: (1) none, (2) intermittent acidic/circum-neutral AMD, (3) continuous acidic AMD, (4) continuous circum-neutral AMD, and (5) receiving system stations with at least two levels of dilution. Bioassessment techniques included water/sediment chemistry, benthic macroinvertebrate sampling, laboratory acute water column toxicity testing, laboratory chronic sediment toxicity testing, and in situ toxicity testing with Asian clams (Corbicula fluminea [Müller]). Group 3 stations had significantly altered water chemistry (low pH, high conductivity, and high water column metals) relative to the other groups and significantly higher sediment iron concentrations. Both group 3 and group 4 stations had significantly decreased ephemeroptera-plecoptera-trichoptera richness and percent ephemeroptera abundance relative to unimpacted stations. Group 3 stations also had decreased total taxon richness. Water column toxicity testing was sensitive to AMD impacts, with samples from group 3 stations being significantly more toxic than those from groups 2 and 4, which in turn were more toxic than those from groups 1 and 5. Similar results were observed for in situ toxicity testing. No differences in sediment toxicity test survival and impairment results were observed among the station groups. Stepwise multiple linear regression and simple bivariate correlation analyses were used to select parameters for use in an ecotoxicologic rating system, which was successful in differentiating between two levels of environmental impact relative to stations receiving no AMD input. [source] Dissimilatory ferrous iron oxidation at a low pH: a novel trait identified in the bacterial subclass RubrobacteridaeFEMS MICROBIOLOGY LETTERS, Issue 2 2008Christopher G. Bryan Abstract A novel iron-oxidizing acidophilic actinobacterium was isolated from spoil material at an abandoned copper mine. Phylogenetic analysis placed the isolate within the Rubrobacteridae subclass of the Actinobacteria. Its optimum temperature and pH for growth are 30,35 °C and pH 3.0, respectively. Although it could catalyze the dissimilatory oxidation of ferrous iron, growth yields declined progressively in media containing ferrous iron concentrations >100 ,M. The isolate, Pa33, did not grow or oxidize iron in the absence of organic carbon, and appeared to be an obligate heterotroph. Specific rates of iron oxidation were much smaller than those determined for the autotrophic iron-oxidizing proteobacterium Acidithiobacillus ferrooxidans and the heterotrophic iron-oxidizing actinobacterium Ferrimicrobium acidiphilum. Iron oxidation by isolate Pa33 appears to be a defensive mechanism, in which iron oxidation converts a soluble species to which the bacterium is sensitive to an oxidized species (ferric iron) that is highly insoluble in the spoil from which it was isolated. This is the first report of acidophily or dissimilatory iron oxidation within the Rubrobacteridae subclass and one of very few within the Actinobacteria phylum as a whole. [source] Genome-wide expression analysis of iron regulation in Burkholderia pseudomallei and Burkholderia mallei using DNA microarraysFEMS MICROBIOLOGY LETTERS, Issue 2 2005Apichai Tuanyok Abstract Burkholderia pseudomallei and B. mallei are the causative agents of melioidosis and glanders, respectively. As iron regulation of gene expression is common in bacteria, in the present studies, we have used microarray analysis to examine the effects of growth in different iron concentrations on the regulation of gene expression in B. pseudomallei and B. mallei. Gene expression profiles for these two bacterial species were similar under high and low iron growth conditions irrespective of growth phase. Growth in low iron led to reduced expression of genes encoding most respiratory metabolic systems and proteins of putative function, such as NADH-dehydrogenases, cytochrome oxidases, and ATP-synthases. In contrast, genes encoding siderophore-mediated iron transport, heme-hemin receptors, and a variety of metabolic enzymes for alternative metabolism were induced under low iron conditions. The overall gene expression profiles suggest that B. pseudomallei and B. mallei are able to adapt to the iron-restricted conditions in the host environment by up-regulating an iron-acquisition system and by using alternative metabolic pathways for energy production. The observations relative to the induction of specific metabolic enzymes during bacterial growth under low iron conditions warrants further experimentation. [source] Variability of Isotope and Major Ion Chemistry in the Allequash Basin, WisconsinGROUND WATER, Issue 7 2003John F. Walker As part of ongoing research conducted at one of the U.S. Geological Survey's Water, Energy, and Biogeochem-ical Budgets sites, work was undertaken to describe the spatial and temporal variability of stream and ground water isotopic composition and cation chemistry in the Trout Lake watershed, to relate the variability to the watershed flow system, and to identify the linkages of geochemical evolution and source of water in the watershed. The results are based on periodic sampling of sites at two scales along Allequash Creek, a small headwater stream in northern Wisconsin. Based on this sampling, there are distinct water isotopic and geochemical differences observed at a smaller hillslope scale and the larger Allequash Creek scale. The variability was larger than expected for this simple watershed, and is likely to be seen in more complex basins. Based on evidence from multiple isotopes and stream chemistry, the flow system arises from three main source waters (terrestrial-, lake-, or wetland-derived recharge) that can be identified along any flowpath using water isotopes together with geochemical characteristics such as iron concentrations. The ground water chemistry demonstrates considerable spatial variability that depends mainly on the flow-path length and water mobility through the aquifer. Calcium concentrations increase with increasing flowpath length, whereas strontium isotope ratios increase with increasing extent of stagnation in either the unsaturated or saturated zones as waters move from source to sink. The flowpath distribution we identify provides important constraints on the calibration of ground water flow models such as that undertaken by Pint et al. (this issue). [source] The solute budget of a forest catchment and solute fluxes within a Pinus radiata and a secondary native forest site, southern ChileHYDROLOGICAL PROCESSES, Issue 13 2002Geertrui Y. P. Uyttendaele Abstract Solute concentrations and fluxes in rainfall, throughfall and stemflow in two forest types, and stream flow in a 90 ha catchment in southern Chile (39°44,S, 73°10,W) were measured. Bulk precipitation pH was 6·1 and conductivity was low. Cation concentrations in rainfall were low (0·58 mg Ca2+ l,1, 0·13 mg K+ l,1, 0·11 mg Mg2+ l,1 and <0·08 mg NH4,N l,1), except for sodium (1·10 mg l,1). Unexpected high levels of nitrate deposition in rainfall (mean concentration 0·38 mg NO3,N l,1, total flux 6·3 kg NO3,N ha,1) were measured. Concentrations of soluble phosphorous in bulk precipitation and stream flow were below detection limits (<0·09 mg l,1) for all events. Stream-flow pH was 6·3 and conductivity was 28·3 ,s. Stream-water chemistry was also dominated by sodium (2·70 mg l,1) followed by Ca, Mg and K (1·31, 0·70 and 0·36 mg l,1). The solute budget indicated a net loss of 3·8 kg Na+ ha,1 year,1, 5·4 kg Mg2+ ha,1 year,1, 1·5 kg Ca2+ ha,1 year,1 and 0·9 kg K+ ha,1 year,1, while 4·9 kg NO3,N ha,1 year,1 was retained by the ecosystem. Stream water is not suitable for domestic use owing to high manganese and, especially, iron concentrations. Throughfall and stemflow chemistry at a pine stand (Pinus radiata D. Don) and a native forest site (Siempreverde type), both located within the catchment, were compared. Nitrate fluxes within both forest sites were similar (1·3 kg NO3,N ha,1 year,1 as throughfall). Cation fluxes in net rainfall (throughfall plus stemflow) at the pine stand generally were higher (34·8 kg Na+ ha,1 year,1, 21·5 kg K+ ha,1 year,1, 5·1 kg Mg2+ ha,1 year,1) compared with the secondary native forest site (24·7 kg Na+ ha,1 year,1, 18·9 kg K+ ha,1 year,1 and 4·4 kg Mg2+ ha,1 year,1). However, calcium deposition beneath the native forest stand was higher (15·9 kg Ca2+ ha,1 year,1) compared with the pine stand (12·6 kg Ca2+ ha,1 year,1). Copyright © 2002 John Wiley & Sons, Ltd. [source] Bone Structural and Mechanical Properties Are Affected by Hypotransferrinemia But Not by Iron Deficiency in MiceJOURNAL OF BONE AND MINERAL RESEARCH, Issue 2 2000Elise A. Malecki Abstract Hypotransferrinemia is a genetic defect in mice resulting in <1% of normal plasma transferrin (Tf) concentrations; heterozygotes for this mutation (+/hpx) have low circulating Tf concentrations. We used this mutant mouse in conjunction with dietary iron deficiency to study the influence of Tf and iron on bone structural and mechanical properties. Twenty-one weanling wild-type BALB/cj +/+ mice and 21 weanling +/hpx mice were fed iron-deficient or iron-adequate diets for 8 weeks. Twelve hpx/hpx mice were fed the iron-adequate diet. Hypotransferrinemia resulted in increased tibia iron and calcium concentrations, lower femur failure load, and extrinsic stiffness. Because the femurs of the hpx/hpx mice were disproportionately small, these bones actually had increased tissue material properties (ultimate stress [US] and modulus of elasticity) than those of wild-type mice. This is the first report on the effect of dietary iron deficiency on bone structural and mechanical properties. Dietary iron deficiency in +/+ and +/hpx mice decreased tibia iron concentrations but had no effect on tibia calcium and phosphorus concentrations or femur structural or mechanical properties. Because the bones of the hpx/hpx mice were small, but had superior tissue mechanical properties, we conclude that Tf is important for normal bone mineralization. (J Bone Miner Res 2000; 15: 271,277) [source] Serum amino-terminal propeptide of type III procollagen and 7S domain of type IV collagen correlate with hepatic iron concentration in patients with chronic hepatitis C following ,-interferon therapyJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 2 2001Ichiro Shimizu Abstract Background: It has been reported that chronic infection with hepatitis C virus is associated with excess iron deposits in the liver of subjects who are neither alcoholics nor recipients of blood transfusions. However, little is known about the relationship between hepatic iron concentration (HIC) and the serum levels of hepatic fibrogenesis markers, which were caused by interferon therapy for chronic hepatitis C. Therefore, changes in the serum amino-terminal propeptide of type III procollagen (P-III-P) and the 7S domain of type IV collagen (7S-IV) in 16 patients treated with ,-interferon (IFN-,) were studied, and their HIC and histological assessment evaluated. Hepatic iron concentrations were measured by using liver biopsy specimens obtained before and 6 months after the cessation of treatment. Methods and Results: Eight subjects (50%) who had normal alanine transaminase levels at 6 months after therapy showed significantly lowered HIC, and attenuated hepatic iron staining with decreased serum levels of P-III-P and 7S-IV compared to the remaining subjects. The HIC was significantly correlated with the serum levels of P-III-P and 7S-IV in all subjects. Conclusions: These findings suggest that IFN-, treatment may decrease stimuli for fibrogenesis, at least in part, by reducing the hepatic iron deposition in patients with chronic hepatitis C. [source] | |||||||||||||||||||