Ilse Steffan

Four‐year study of cobalt and chromium blood levels in patients managed with two different metal‐on‐metal total hip replacements

Background: Metal‐on‐metal total hip prostheses will produce a certain amount of wear debris. This results in increased whole‐blood metal levels, which may cause adverse effects. It is not known to what extent the problem has been overcome by advances in alloy technology.

Concentrations of Seven Trace Elements in Different Hematological Matrices in Patients with Type 2 Diabetes as Compared to Healthy Controls

This study aimed to compare the trace element status of patients with type 2 diabetes (n=53) with those of nondiabetic healthy controls (n=50). The concentrations of seven trace elements were determined in the whole blood, blood plasma, erythrocytes, and lymphocytes of the study subjects. Vanadium and iron levels in lymphocytes were significantly higher in diabetic patients as compared to controls (p<0.05 for iron and p<0.01 for vanadium). In contrast, lower manganese (p<0.01) and selenium (p<0.01) concentrations were detected in lymphocytes derived from patients with type 2 diabetes versus healthy subjects. Furthermore, significantly lower chromium levels (p<0.05) were found in the plasma of diabetic individuals as compared to controls. Trace element concentrations were not dependent on the degree of glucose control as determined by correlation analysis between HBA1c versus metal levels in the four blood fractions. In summary, this study primarily demonstrated that trace element levels in lymphocytes of patients with type 2 diabetes could deviate significantly from controls, whereas, in general, no considerable differences could be found when comparing the other fractions between both patient groups. Therefore, it seems reasonable to analyze metal levels in leukocytes to determine trace element status in patients with type 2 diabetes and perhaps in other diseases.

Determination of Cu, Fe, Mn, and Zn in blood fractions by SEC-HPLC-ICP-AES coupling.

The binding of Cu, Fe, Mn, and Zn to proteins in blood and in blood fractions was investigated, since their interactions in free radical metabolism in humans is of great interest. An HPLC-ICP-AES technique was developed allowing adequate separation of metalloproteins and of inorganic and organic metal species. For the separation of metalloproteins in erythrocytes and blood plasma a Merck Superformance Fractogel EMD BioSEC 650 (S) column was used. Size exclusion chromatography (SEC)-HPLC was hyphenated to ICP-AES both on-line and off-line for the detection of trace elements in the fractions resulting from HPLC separations. HPLC parameters, pH, temperature, flow rate and salt concentration were optimized for the protein separation and the optimal conditions were applied for the hyphenation to the ICP-AES detector. The separation column was calibrated with five standard proteins. For the element determination by ICP-AES a line selection with respect to the sensitivity was performed. Three different methods were used for the determination of trace elements in blood: direct determinations, on-line and off-line SEC-HPLC-ICP-AES measurements. For the optimizing experiments blood samples of one female subject were used. The direct determination by ICP-AES of the elements was performed in blood and blood fractions of ten different subjects to obtain the average concentration ranges. From the results the identification of the protein Cu/Zn superoxide dismutase in erythrocytes was possible. The LOD were 0.03 microgram mL-1 for Cu, 0.026 microgram mL-1 for Fe, 0.8 ng mL-1 for Mn, and 0.09 microgram mL-1 for Zn in a synthetic blood matrix.

Determination of trace elements in pumpkin seed oils and pumpkin seeds by ICP-AES

Inductively coupled plasma atomic emission spectrometry (ICP-AES) was used for the determination of the elements present in pumpkin seed oil and pumpkin seeds. After extraction of the oil from pumpkin seeds a residue was obtained. For the determination of elements three types of samples were used: oil, seeds and the residue (after oil extraction). Three different digestion types were applied: open vessel and closed vessel digestion in a steel bomb as well as microwave digestion in a closed system. For most elements of interest the measured concentration differs depending on the digestion method used. After microwave digestion a good reproducibility for ICP-AES measurements for all elements was found. Determination of Zn by ICP-AES is possible both after open and closed vessel digestion (steel bomb or microwave digestion). No loss of volatile compounds in pumpkin oil during preparation or microwave digestion prior to ICP-AES analysis could be observed. In general, the recoveries for all elements in pumpkin seed oils and seeds were >95%, for S only they were 0.8 µg g−1 for Al, Cr and P in pumpkin oil samples.

Toxic and biochemical effects of zinc in Caco-2 cells

Zinc (in relatively high concentrations) can be toxic to intestinal cells. The aim of the present study was to quanitfy cellular injury in preconfluent, colonic cancerous cells and in postconfluent, differentiating human intestinal Caco-2 cells. Cellular damage was measured by using cell proliferation, lactate dehydrogenase (LDH)-release, and apoptosis studies. Furthermore, the activities of the major antioxidative enzymes [superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase] and differentiation markers (alkaline phosphatase and aminopeptidase-N) were determined after exposure of the cells to increasing amounts of zinc sulfate. Proliferation and viability decreased in a concentration-dependent manner. A noticeable increase of LDH-release correlated to cell rounding and detachment at relatively high zinc levels (200 muM) was observed in both groups of cells. Above 100 muM of zinc, significant apoptotic activity was found in the preconfluent cells. Zinc supplementation did not alter SOD activities. However, GPx and, in part, catalase activities tended to be higher in zinc-treated cells (nevertheless the results were not significant). Differentiation markers were noticeably induced by increasing amounts of zinc, especially in the preconfluent cells. In conclusion, we suggest that the susceptibility to zinc induced damage is equal in both confluentation groups of Caco-2 cells. Risk assessment for high concentrations seems recommendable.

Are allergic reactions to skin clips associated with delayed wound healing

BACKGROUND Metal skin clips are used in surgery. They may contain metals that might cause allergic reactions and delayed wound healing. METHODS The metal composition of 18 different surgical clamps was examined. The allergy status of 184 patients was determined by patch tests and was correlated with the clinical outcome of wound healing after application of skin clips. RESULTS Skin clips contained chromium, nickel, molybdenum, cobalt, and titanium in concentrations high enough to cause allergic reactions. Eighteen percent of the men and 23% of the women were sensitive to nickel and 16% of the men to chromium. We found a positive correlation between the grade of nickel allergy and the reaction to the skin clips. CONCLUSIONS Our study suggests that allergic reactions and delayed wound healing can be caused by the use of surgical skin clips. Therefore skin clips are not recommended for patients with a history of contact dermatitis to metals and/or atopy.

Comparison of methods for the determination of vanadium in sea-water

Procedures for the determination of vanadium in sea-water have been independently developed at two laboratories. The separation and concentration steps were distinctly different and quantification was by neutron activation or atomic absorption. Both methods provide a reliable measurement of vanadium concentration at natural levels in sea-water.

Determination of 28 selected elements in textiles by axially viewed inductively coupled plasma optical emission spectrometry

A simple, robust and reliable analytical procedure for the determination of 28 selected elements, namely Al, As, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, K, Hg, Mg, Mn, Mo, Na, Ni, Pb, Sc, Si, Se, Sn, Sm, Sr, Tl, V, and Zn in textile materials by inductively coupled plasma optical emission spectrometry (ICP-OES) after microwave digestion of samples was optimized and validated in this work. The total amount of elements present in textile samples was determined after microwave digestion of materials in 7 mol/L nitric acid within the optimal working program: 5 min at 150°C (power 250 W), 15 min 180°C (300 W) and 20 min at the maximum temperature of 200°C (350 W). For the quality control reasons, which were ascertained by analysis of the certified cotton trace elements reference material IAEA-V9, the ICP-OES method was optimized through several parameters: by comparing Meinhard and Gemcone Low Flow nebulizers efficiency, ranging nebulizer gas flows from 0.6 to 1.0 L/min, ranging sample flows from 0.8 to 1.2 mL/min, testing RF power from 1200 to 1400 W, detecting data acquisition time (read time) from 0 to 527 s, ranging washing (delay) time from 0 to 408 s, as well as by checking the occurring interferences for the optimal line selection. Validation included determination of linearity, selectivity, accuracy, reproducibility, precision and limits of detection calculated for all 28 selected elements of interest. The developed analytical procedure was successfully applied on textile fibers (cotton, flax and hemp) as well as on standard knitted textile sample materials (cotton and wool).

Hydrophobic interaction chromatographic separation of proteins in human blood fractions hyphenated to atomic spectrometry as detector of essential elements

The binding of metals to proteins in blood fractions was investigated applying hydrophobic interaction chromatography (HIC) for protein separation and graphite furnace atomic absorption spectrometry (GFAAS) as the element specific detector. For the semi-preparative separation of metalloproteins in erythrocytes and blood plasma, a HIC column (Fractogel EMD Phenyl I (S) 150 mm x 10 mm I.D.) was adapted. The separation column was calibrated with the same four standard proteins as used in Pomazal et al. [Analyst 124 (1999) 657]. The sample injection volume and the ammonium sulphate gradient set-up were optimized: 20 or 200 microl, respectively, of blood plasma and of lysed erythrocytes were injected. The separated proteins were collected in 4-ml fractions and analyzed by GFAAS off-line. An optimization of the GFAAS measuring parameters for Cu, Mn, Fe, Zn, Co, Ni, and Cr was performed. For each element, a specific temperature program was optimized with respect to the matrix of the HIC eluate (0.02 M NaH2PO4, 1.8 M (NH4)2SO4). The obtained metal profiles of the eluate were compared with the HIC chromatograms. The limits of detection (LOD) for the elements by GFAAS were: 0.5 ng Cu/ml; 0.2 ng Mn/ml; 1 ng Fe/ml; 0.2 ng Zn/ml; 0.12 ng Co/ml; 0.2 ng Ni/ml; 0.16 ng Cr/ml. The GFAAS method enabled the detection of the proteins of interest via the metals.

Uranium series method applied to fossil bone

In connection with the application of the uranium series method for the dating of fossil bones, separation techniques were developed for the isolation of uranium and thorium from a bone matrix. These separations were achieved on columns of the strongly basic anion exchange resin Dowex 1, using media of hydrochloric acid (for the isolation of uranium) and nitric acid (for the isolation of thorium). For uranium and thorium, yields of about 100% and about 70%, respectively, were obtained. The measurement of the α-activities was carried out following the electrolytic preparation of thin-layers of uranium and thorium on stainless steel discs. The α-spectrometry was done by means of Si-surface barrier detectors. Results are presented for a sample of snake-bones found in an Austrian cave.