Relation between blood levels of heavy metals and some markers of oxidative stress among boys with neuropathic bladder and posterior urethral valve.

BACKGROUND: The status of heavy metals in children with lower urinary tract pathology that may harm the upper tract, e.g., neuropathic bladder and posterior urethral valve and its relationship with oxidative stress has not been adequately investigated. Therefore, the object of the current work was to evaluate the concentrations of copper, zinc, cadmium and lead and their relations with levels of catalase (CAT), malondialdehyde (MDA) and glutathione (GSH) in boys with neuropathic bladder and posterior urethral valve. METHODS: Thirty-six children with neuropathic bladder, 35 children with posterior urethral valve and 33 health controls were included in the study. In addition to routine laboratory tests, blood samples were collected from patients and controls to assess levels of Cu, Zn, Cd and Pb in addition to plasma concentrations of CAT, MDA and GSH. RESULTS: Significantly elevated levels of Cu, Pb, CAT, MDA and GSH and significantly lower concentration of blood Zn were found in the studied groups compared to the controls. In the posterior urethral valve group, blood level of Cu was positively correlated with GSH while a significantly negative relation was observed between blood Zn and CAT activity among the neuropathic bladder patients. CONCLUSION: Neuropathic bladder and posterior urethral valve may lead to abnormalities in the blood levels of heavy metals (i.e. Cu, Pb and Zn) and markers of oxidative stress (CAT, MDA and GSH). Therefore, the levels of theses metal ions should be monitored during the treatment course of neuropathic bladder and posterior urethral valve patients to prevent or minimize long-term oxidative injury.

Chemically modified rice husk as an effective adsorbent for removal of palladium ions.

Bio-matrix of rice husk and Mobil Composition of Matter No. 41 (MCM-41) was modified with alizarin red S for preconcentration of Pd2+ prior flame atomic absorption spectrometric determination. The prepared bio-matrix (RH@MCM-41@ARS) was characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope, energy dispersive X-ray spectrometer (SEM/EDX) and surface area studies. The impact of different parameters (solution pH, amount of sorbent, contact time, sample volume, initial Pd2+ concentration and diverse ions) on the uptake of Pd2+ were evaluated. The maximum adsorption capacity of Pd2+ onto RH@MCM-41@ARS was 198.2 mg g-1 at optimum conditions. Applying the optimized procedure as a preconcentration step led to limit of detection of 0.13 µg L-1 and dynamic analytical range up to 500 µg L-1. The sorbent was regenerated by 0.5 mol L-1 thiourea for at least 10 cycles without significant reduction of adsorption capacity. The method was applied for preconcentration of Pd2+ from real samples.

Impact of dialyzer membrane flux on metal clearance in hemodialysis patients.

Deficiency of essential trace elements (such as Cu or Zn) and accumulation of potentially toxic trace elements (as Cd or Pb) are both known to have adverse effects in hemodialysis (HD) patients. Up to our knowledge, no studies about the permeability of low and high flux polysulfone membranes on metal ions during hemodialysis are available. Therefore, the aim of the present study was to address this issue. Forty one hemodialysis patients (19 were using high flux polysulfone membrane while the remaining were using low flux one) participated in the study. Blood levels of Cu, Zn, Cd and Pb were determined by graphite furnace atomic absorption spectrometry among HD patients, before and after dialysis session, as well as among matched 40 healthy persons. Blood concentrations of Cu and Zn in the whole hemodialysis group was significantly lower than those of the healthy control group, on the other hand the toxic metals (Cd and Pb) levels were observed to be significantly higher among HD patients compared to the normal persons. Among the hemodialysis group, there were no significant differences between the low and high flux dialyzer groups in terms of pre-dialysis blood levels of Cu, Zn, Cd and Pb. In addition, significantly decreased levels of all metal ions were observed after dialysis sessions using either low or high flux membranes. An exception was Pb which did not show any difference between pre-dialysis and post-dialysis values in the low flux groupIn conclusion Zn and Cu deficiencies should be considered in the treatment of these patients. High flux membranes are more efficient than low flux ones in removing excess Cd and Pb. Therefore, when high flux membranes are used, chelation therapy might not be required for Cd and Pb overload.

Determination of Cu(2+), Zn(2+) and Pb(2+) in biological and food samples by FAAS after preconcentration with hydroxyapatite nanorods originated from eggshell.

Hydroxyapatite nanorods (HAPNRs) were prepared from recycled eggshell by using precipitation method. The structure of the HAPNRs was physicochemically and morphologically characterized by X-ray diffraction, transmission electron microscopy and Fourier transform infrared spectroscopy. The resulting HAPNRs were used for solid phase extractive preconcentration of Cu(2+), Zn(2+) and Pb(2+) prior to its determination by flame atomic absorption spectrometry. Experimental variables that influence the quantitative extraction of metal ions were optimized by both batch and column methods. The analytes were quantitatively sorbed on the matrix between pHs6 and 9. The maximum sorption capacity of the HAPNRs has been found to be 2.43, 2.37 and 2.53 mmol g(-1) for Cu(2+), Zn(2+) and Pb(2+), respectively, with the preconcentration factor of 250. The 3σ detection limit and 10σ quantification limit for Cu(2+), Zn(2+) and Pb(2+) were found to be 0.72, 0.55 and 5.12 µg L(-1) and 2.40, 1.83 and 17.06 µg L(-1), respectively. The calibration curves were linear up to 250 µg L(-1) for Cu(2+), 300 µg L(-1) for Zn(2+) and 400 µg L(-1) for Pb(2+). Accuracy of the proposed method was verified using certified reference materials (NCS ZC85006 Tomato, Seronorm Trace Elements Whole Blood L-1, Seronorm Trace Elements Whole Blood L-3 and Seronorm Trace Elements Urine). The present method was successfully applied to the analysis of these metal ions in sea water, biological and food samples.