Brain susceptibility changes in neurologically asymptomatic pediatric patients with Wilson's disease: evaluation with quantitative susceptibility mapping.

Background Wilson's disease (WD) is a copper metabolism disorder that causes hepatolenticular degeneration. It is important to diagnose WD before central nervous system involvement. Purpose To demonstrate the early susceptibility changes associated with the copper accumulation in the brain of neurologically asymptomatic pediatric patients with WD using quantitative susceptibility mapping (QSM). Material and Methods Twelve patients with neurologically asymptomatic WD (mean age = 13.7 ± 3.3 years) and 14 age-matched controls were prospectively examined using a 1.5-T clinical scanner. Routine magnetic resonance (MR) sequences and a three-dimensional multi-echo spoiled gradient echo (GRE) sequence were used and QSM maps were reproduced. The quantitative susceptibility of corpus striatum, thalamus, substantia nigra, and pons were analyzed with the region of interest analysis on QSM maps. The susceptibility values of two groups were statistically compared using a two-sample t-test. Results Conventional MR images of the patients and control group were similar. However increased magnetic susceptibility in the thalamus, pons and left posterior putamen were observed in the patients compared to the control group ( p < 0.05). Conclusion We observed statistically increased susceptibility values in the brains of neurologically asymptomatic patients with WD although the conventional MR images were normal. This might be compatible with early brain impairment, before neurological symptoms occur.

Determination of some trace elements in food and soil samples by atomic absorption spectrometry after coprecipitation with holmium hydroxide.

The determination of trace elements in food and soil samples by atomic absorption spectrometry was investigated. A coprecipitation procedure with holmium hydroxide was used for separation-preconcentration of trace elements. Trace amounts of copper(II), manganese(II), cobalt(II), nickel(ll), chromium(lll), iron(Ill), cadmium(ll), and lead(ll) ions were coprecipitated with holmium hydroxide in 2.0 M NaOH medium. The optimum conditions for the coprecipitation process were investigated for several commonly tested experimental parameters, such as amount of coprecipitant, effect of standing time, centrifugation rate and time, and sample volume. The precision, based on replicate analysis, was lower than 10% for the analytes. In order to verify the accuracy of the method, the certified reference materials BCR 141 R calcareous loam soil and CRM 025-050 soil were analyzed. The procedure was successfully applied for separation and preconcentration of the investigated ions in various food and soil samples. An amount of the solid samples was decomposed with 15 mL concentrated hydrochloric acid-concentrated nitric acid (3 + 1). The preconcentration procedure was then applied to the final solutions. The concentration of trace elements in samples was determined by atomic absorption spectrometry.

Identifying the effects of excess weight, metabolic syndrome and insulin resistance on liver stiffness using ultrasound elastography in children.

BACKGROUND: Metabolic syndrome (MetS) and insulin resistance (IR) are known predictors of nonalcoholic fatty liver disease (NAFLD) which is one of the significant comorbidities of obesity. Obese children with MetS and IR are reported to be more likely to have advanced liver fibrosis compared to those without MetS or IR. The aim of this study is to determine the effects of excess weight, MetS and IR on liver fibrosis assessing liver stiffness in children using ultrasound elastography and compare gray scale ultrasonographic findings of hepatic steatosis (HS) with liver fibrosis. METHODS: The study group involved 131 overweight/obese children. The control group involved 50 healthy lean children. Groups were adjusted according to body mass index (BMI) and BMI-standard deviation scores (SDS). Liver stiffness measurements which are expressed by shear wave velocity (SWV) were performed for each individual. The study group was further subgrouped as children with MetS and without MetS, with IR and without IR. RESULTS: The mean SWV of liver was 1,07 ± 0,12 m/s in the control group and 1,15 ± 0,51 m/s in the study group. The difference was significant (p=0,047). SWV of liver was weakly correlated with age, BMI, BMI-SDS, Homeostatic Model Assessment-Insulin Resistance and high-density lipoprotein cholesterol. The mean SWV of the liver in the study group for children without MetS was 1,1 ± 0,44 m/s, with MetS was 1,23 ± 0,70 m/s. The difference was not significant (p=0,719). The mean SWV of the liver in the study group for children without IR was 1,02 ± 0,29 m/s, with IR was 1,24 ± 0,61 m/s. The difference was not significant (p=0,101). In multivariate regression analysis, the only independent factor affecting liver stiffness was BMI-SDS (OR:2,584, 95% CI: 1,255- 5,318, p=0,010). CONCLUSIONS: Obesity itself, regardless of MetS or IR seems to be the major problem affecting liver stiffness in this study. However, large scale longitudinal studies might clarify this issue.

Extractable trace metals content of dust from vehicle air filters as determined by sequential extraction and flame atomic absorption spectrometry.

A modified four-step sequential extraction procedure developed within the Standards, Measurement, and Testing Program (formally the Community Bureau of Reference) of the European Commission was applied to determine the distribution of Cd, Cu, Fe, and Mn in air filter dust samples collected from vehicles. The four fractions were acid-soluble, reducible, oxidizable, and residual. These fractions have the advantage of providing better insight into the mechanism of association of metals in the dust. The determination of trace metals in dust samples was performed by flame atomic absorption spectrometry. The results obtained after applying the sequential extraction scheme indicated that Cu was the most abundant metal in the organic and residual fractions of the dust matrix. Fe was found mainly in the residual fraction, and the major amounts of Mn and Cd were present in the acid-soluble and bound-to-carbonate fraction. The mean values of Cd, Cu, Fe, and Mn were found to be 15.58, 33.54, 1625, and 180 microg/g, respectively. The results obtained are in agreement with data reported in the literature.

Evaluation of various digestion procedures for trace element contents of some food materials.

The levels of trace elements in different types of food material consumed in Turkey were determined by flame and graphite furnace atomic absorption spectrometry. Food samples were digested with dry ashing, wet ashing and microwave digestion procedures in this study. The microwave digestion procedure was chosen for the digestion of all the food samples because it required shorter time and made higher recovery (specially for Se). Fe, Cu, Mn, Zn, Al and Se were determined by flame and graphite furnace atomic absorption spectrometry, respectively. Relative standard deviations (RSD) were found below 10%. The accuracy of the procedure was confirmed by certified reference materials. Moreover, this procedure was easier to use when compared with dry and wet digestions.

Apparent diffusion coefficient in differentiation of pediatric posterior fossa tumors.

PURPOSE: To investigate the contribution of preoperative apparent diffusion coefficient (ADC) values in the differential diagnosis of pediatric posterior fossa tumors. METHODS: Forty-two pediatric patients (mean age 7.76 ± 4.58 years) with intra-axial tumors in the infra-tentorial region underwent magnetic resonance imaging. ADC measurement was performed using regions of interest, obtained from the solid component of the mass lesions. ADC ratios were calculated by dividing the ADC values from the mass lesions by the ADC values from normal cerebellar parenchyma. Lesions were categorized as juvenile pilocytic astrocytoma (JPA), ependymoma and medulloblastoma based on histopathological diagnosis. ADC values of the lesions and histopathological diagnoses were statistically correlated. RESULTS: Histopathological diagnosis showed that 14 lesions were JPA, 10 were ependymoma; 18 were medulloblastoma. Both ADC values and ADC ratios were significantly correlated with tumor types (p <0.05). Astrocytoma was distinguished from ependymoma with sensitivity 85.7% and specificity 90% using an ADC ratio ≥1.7 and medulloblastoma was distinguished from ependymoma with sensitivity 100% and specificity 88.89% using an ADC ratio ≤1.18. CONCLUSION: Preoperative ADC values could differentiate the main histological subtypes of pediatric posterior fossa tumors with high sensitivity and specificity.

Speciation of antimony using chromosorb 102 resin as a retention medium.

The selective retention of the Sb(III) chelate with ammonium pyrrolidine dithiocarbamate (APDC) on a column of Chromosorb 102 resin from a buffered sample solution including Sb(V) was used for the determination of Sb(III). The retained antimony was eluted with acetone. The retention of the Sb(III)-iodide compounds with sodium iodide on the Chromosorb 102 resin column from the same solution after reducing Sb(V) to Sb(III) by iodide in acidic solution was used to preconcentrate the total antimony. The retained antimony was eluted with 0.25 mol l(-1) HNO3. The antimony in the effluent was determined by flame atomic-absorption spectrometry. Also, the total antimony was determined directly by graphite-furnace atomic absorption spectrometry. The Sb(V) concentration could be calculated by the difference. The recoveries were > or = 95%. The detection limits of a combination of the column procedure and flame AAS for antimony were 6 - 61 microg l(-1) and comparable to 4 microg l(-1) for a direct GFAAS measurement. The relative standard deviations were <6%. The procedure was applied to the determination of Sb(III) and Sb(V) in spiked tap water, waste-water samples and a certified copper metal with the satisfactory results.

Carrier element-free coprecipitation (CEFC) method for separation and pre-concentration of some metal ions in natural water and soil samples.

A simple, rapid and sensitive separation/pre-concentration procedure for Cd(II), Cr(III), Co(II), Cu(II), Fe(III), Pb(II) and Mn(II) ions in environmental samples has been established. The present procedure is based on a combination of carrier element-free coprecipitation (CEFC) and flame atomic absorption spectrometric (FAAS) determinations of understudy trace metal ions. A cationic surfactant (N-cetyl N,N,N trimethyl ammonium bromide (CTAB)) as coprecipitant was used without adding any carrier element for coprecipitation of understudy ions. The optimum conditions for the coprecipitation process were investigated on several commonly tested experimental parameters, such as pH of the solution, amount of coprecipitant. The pre-concentration factor was found to be 10. The detection limits corresponding to three times the standard deviation of the blank (N=20) for Cd(II), Cr(III), Co(II), Cu(II), Fe(III), Pb(II) and Mn(II) ions were found as 0.61, 16.8, 12.7, 1.36, 2.08, 4.30 and 0.22 microg L(-1), respectively. The present procedure was successfully applied for separation and pre-concentration of investigated ions in several liquid environmental samples. In order to support the accuracy of the method, the certified reference materials (BCR 141 R calcareous loam soil and CRM025-050 soil) were analyzed. The experimental results are in good agreement with the certified values.

Evaluation of trace element contents of dried apricot samples from Turkey.

The trace and toxic elements (TEs) were determined in apricot samples by flame and graphite furnace atomic absorption spectrometry, prior to microwave-assisted acid digestion. Among all determined TEs, iron was found to be the dominant elemental ion as compared with other TEs in apricots followed by zinc and manganese ions. The concentration of essential TEs were observed in the range of 10.4-80.1, 0.92-6.49, 0.97-8.27, 2.96-12.0 microg g(-1), 4.76-28.9 microg kg(-1) and 0.32-0.64 microg g(-1) for iron, copper, manganese, zinc, chromium and selenium ions, respectively. While the toxic elemental contents were observed in the range of 0.02-0.72, 0.72-3.77, 2.30-5.83 and 0.08-0.22 microg g(-1) for cadmium, lead, nickel and aluminium ions, respectively. The results were compared with the literature reported values.

Membrane filtration - atomic absorption spectrometry combination for copper, cobalt, cadmium, lead and chromium in environmental samples.

Cellulose nitrate membrane filter was used for the preconcentration-separation of Cu, Co, Cd, Pb and Cr ions. The analyte ions were collected on the membrane filter by the aid of carmine. Then membrane filter was dissolved by using nitric acid. The levels of the analytes in the final solutions were determined by flame atomic absorption spectrometry (FAAS). The analytical parameters including pH, amounts of carmine, sample volumes etc. have been optimized. No influences have been observed from the matrix ions. The detection limits for analytes were in the range of 0.08 microg/l-0.93 microg/l. The validation of the procedure was checked by the analysis of standard reference sediment (GBW 07309). The present method has been successfully applied for the FAAS determinations of analyte ions in real samples including black tea and magnesium salts.

Coprecipitation of heavy metals with erbium hydroxide for their flame atomic absorption spectrometric determinations in environmental samples.

Trace amounts of copper, manganese, cobalt, chromium, iron and lead were quantitatively coprecipitated with erbium hydroxide on 0.05M NaOH medium. The coprecipitant could be easily dissolved with 1M nitric acid. The presence of up to 15g/l of erbium ions did not interfere with the atomic absorption spectrometric determination of analyte ions. The recovery values for analyte ions were higher than 95%. The concentration factor was 25-fold. Coprecipitation parameters including reagent amounts and matrix effects are discussed. The relative standard deviations of the determinations were below 9%. The time required for the coprecipitation was about 30min. The proposed method was successfully applied for the determination of trace amounts of analyte ions in urine, soil and sediment, natural water samples.

Separation/preconcentration of trace heavy metals in urine, sediment and dialysis concentrates by coprecipitation with samarium hydroxide for atomic absorption spectrometry.

Multi-element determination of trace elements in urine and dialysis solutions by atomic absorption spectrometry has been investigated. Coprecipitation with samarium hydroxide was used for preconcentration of trace elements and elimination of matrix elements. To 10 ml of each sample was added 500 mul of 2 mgml(-1) samarium solutions; the pH was then adjusted to 12.2 in order to collect trace heavy metals on samarium hydroxide. The precipitate was separated by centrifugation and dissolved in 1 ml of 1 moll(-1) HNO(3). Coprecipitation parameters and matrix effects are discussed. The precision, based on replicate analysis, is around 5% for the analytes, and recovery is quantitative, based on analysis of spiked samples and solutions including matrix components. The time required for the coprecipitation and determination was about 30 min.