Hintergrund: Es wird vermutet, dass oxidativer Stress zu Erkrankungen des sehr unreifen Frühgeborenen, wie bronchopulmonale Dysplasie (BPD), Hirnblutung (IVH), Retinopathia prematurorum (ROP) und nekrotisierende Enterokolitis (NEC) führt. Ziel unserer Studie war es, zu untersuchen, ob diese Erkrankungen bei Frühgeborenen mit einem Geburtsgewicht von <1000g zu einer Erniedrigung der Aktivität der antioxidativen Enzyme und der Konzentrationen der Spurenelemente führen. Methoden: 209 Frühgeborene wurden in die randomisierte Erythropoietin- Studie der Europäischen Multizentrischen Erythropoietin Beta-Studiengruppe eingeschlossen; 155 entwickelten die o.g. Frühgeborenenerkrankungen. Wir analysierten Zn, Cu, Fe, Se im Serum und in Erythrozyten (RBC), sowie die Glutathionperoxidase (GSH-Px), Superoxiddismutase (SOD), Katalase (CAT) and Karboanhydrase (CA) I/II in RBC am 3. und 68. Lebenstag. Zn, Cu, Fe und Se in Serum und RBC wurden mit der Induktiv gekoppelten Plasma- Massenspektrometrie (ICP-MS, Perkin Elmer) gemessen. Die Enzymaktivitäten wurden spektrophotometrisch (Beckmann DU 650, München) mittels verschiedener Methoden analysiert. Ergebnisse: Zn, Fe und Se im Serum und Se im RBC fielen bis zu 10 Lebenswochen ab (p<0,001), während SOD (p<0,05) und CA (p<0,01) anstiegen. Verglichen mit einer Referenzgruppe (ohne o.g. Frühgeborenenerkrankungen) von 54 Frühgeborenen <1000g Geburtsgewicht, war am 3. Lebenstag Fe niedriger in Serum und RBC (p<0,05) und CAT höher (p<0,01). Am 68. Lebenstag fanden wir Zn und Cu im Serum niedriger und SOD und CAT höher (p<0,05) als in der Referenzgruppe. Diskussion: Je unreifer die Frühgeborenen waren, umso häufiger traten die o.g. Erkrankungen auf. Das war nicht verbunden mit postnatalen Unterschieden in den antioxidativen Enzymen. Im Vergleich zur Referenzgruppe zeigen erhöhte Werte von SOD und CAT bei den erkrankten Frühgeborenen die Aktivierung des antioxidativen Systems an. Diese Aktivitätssteigerung war jedoch kleiner als erwartet. SOD und CA stiegen bei den meisten kranken Frühgeborenen in den ersten 10 Wochen an, während die Spurenelementspiegel abfielen.

BACKGROUND:Very low birth weight infants (<1500 g) have high nutritional needs. Deficiencies of minerals, trace elements (especially zinc) may develop as a result of rapid growth, low body stores and low content of these substances in human milk We hypothesized that fortification of human milk might prevent deficiencies.METHODS:Prospective, randomized trial to evaluate mineral, trace element, thyroid status and growth of infants fed human milk fortified with different amounts of calcium, phosphorus and protein, with (BMF) or without (FM 85) trace elements. Sixty-two infants, 1000 to 1499 g birth weight, were randomized. Minerals and trace elements in serum, red blood cells and human milk and alkaline phosphatase activity, TSH, T4 and FT4 in serum were measured once until the fifth day and at 3 and 6 weeks of life. Clinical course and anthropometric measurements were recorded.RESULTS:Intake of zinc, copper, manganese, calcium, phosphorus and magnesium was higher in the BMF group (P < 0.001). Serum zinc concentrations <0.49 mg/L occurred in 12% of the FM 85 group and 7% of the BMF group at 6 weeks (not significant). Median alkaline phosphatase activity was 436/379 IU/L in the FM 85/BMF group at 6 weeks (P < 0.01). The FM 85 group showed a higher weight gain (P < 0.05), possibly because of higher caloric (P < 0.01) and protein intake (P < 0.05) at 3 weeks.CONCLUSIONS:Zinc deficiency was rare. Elevated intake of calcium, phosphorus and zinc was associated with lower serum alkaline phosphatase activity but did not influence serum zinc concentration.

Capillary zone electrophoresis, with its high resolution capability in the separation of different compounds, is well suited for the investigation of metal-containing proteins, especially when elemental detection is conducted using hyphenated inductively coupled plasma-mass spectrometry. A major problem in the separation of proteins in body fluids is caused by the effects of different sample matrix composition. The migration time of proteins varies significantly, depending on the nature of the matrix. Electropherograms are consequently difficult to compare and the peak identification is uncertain. Pre-analytical steps for the reduction of matrix compounds enhance the quality of the data, but the results are still unsatisfactory. This paper describes a technique for obtaining electropherograms that can be used for comparison purposes by correction of the data with the aid of time markers. A mixture of five substances (caesium chloride, arsenocholine, arsenobetaine, dimethylarsinic acid and monomethylarsonic acid) was added in a separate injection step. Ionic caesium eluted at the start of the separation and the other four markers appeared throughout and at the end of the electropherogram. All electropherograms were normalized to a reference run by recalculation of the time axis using the time markers. The method was applied to the analysis of human brain cytosols. Samples were separated after different pre-treatment steps and were compared, with special emphasis on the detection of the isoform metallothionein-3.

Objective: Extremely low birthweight (<1000 g) infants are growing rapidly and their nutritional requirements for calcium, phosphorus, magnesium are high. Design: Prospective, mineral balance. Setting: The study was carried out at the Department of Neonatology, Virchow-Hospital, Charité Berlin and the Department of Molecular Trace Element Research, Hahn-Meitner-Institute Berlin. Subjects: Nineteen infants <1000 g birthweight were admitted, nine infants dropped out and 10 infants (birthweight 730–995 g), fed fortified human milk were included. Intervention: We collected infant's urine and feces for 72 h, a sample of human milk and infant's blood at 7 and 12 weeks of age. Elements were measured by inductively coupled plasma atomic emission spectrophotometry. Results: Mean (s.d.) mineral concentration in milk was low especially at 12 weeks: calcium 9.88 (±3.58) mmol/l, phosphorus 7.02 (±3.81) mmol/l, magnesium 1.59 (±0.54) mmol/l. Calcium retention was minimal or negative during the study, whereas phosphorus and magnesium balances were positive. Caffeine and diuretics increased mineral excretion. Serum alkaline phosphatase was mostly <800 U/l, and 162 U/l in one infant with zinc deficiency at 12 weeks. Alkaline phosphatase correlated with absorption and retention of phosphorus, and with longitudinal growth. Conclusions: Infants <1000 g have high nutritional needs for calcium, phosphorus and magnesium, which are not met by a human milk fortifier widely used in Europe. Controlled trials are needed to assess requirements, duration and risks of mineral supplementation.

ABSTRACT Background Zinc is important for metabolism, cell growth, immunity, and defense against oxygen radicals. Extremely low‐birth‐weight (< 1000 g) infants have higher nutritional needs, but information on zinc is scarce. The authors performed nutritional balances in 10 infants with birth weights of 500 to 999 g and who were fed with fortified human milk. Methods The authors collected infant feces, urine, and blood and human milk samples during 72 hours at 7 and 12 weeks of age. Zinc concentration was measured by inductively coupled plasma–mass spectrophotometry, atomic emission spectro‐photometry, and instrumental neutron activation analysis. Results Mean (SD) intake via human milk was 379 (± 373) μg · kg −1 · d −1 during both balances. Urinary excretion was high at 7 weeks of age, decreased to half at 12 week, and was negatively correlated ( P < 0.01) with weight gain. Mean absorption was slightly positive at 7 weeks of age but zero or negative in most infants at 12 weeks of age. Retention was negative in all infants at both observation periods, except in one infant during the second balance. Clinical zinc deficiency developed in one infant at 12 weeks of age. Conclusions Zinc balances in extremely low‐birth‐weight infants are highly variable and usually negative. Controlled trials are needed to assess need for and benefits and risks of zinc supplementation.

Fractions containing metallothioneins (MT's), extracted from the liver cytosol of humans, were analysed to determine the complete distribution pattern of the metals copper, cadmium and zinc. Samples of cirrhotic livers which had come from organs removed during transplantation were examined for differences in the trace-element binding pattern. After the extraction of supernatants from the tissue samples, membrane ultrafiltration of the cytosolic solution was carried out to separate all high-molecular proteins with molecular weights >100 kDa. This procedure retains the metal content of the MT's in its initial form, in contrast to the often-used heat treatment of samples, which changes the copper distribution significantly. The MT's themself were isolated using size exclusion and anion exchange chromatography. Their metal content was determined simultaneously on-line by combination with an ICP-AES as element detector. Calibration of the procedure was performed by means of a column by-pass-injection of elemental standards into the separation system. The MT content in the samples was calculated using the determined metal concentrations and the generally accepted metal/protein ratios for Cu (12:1), Cd (7:1) and Zn (7:1). These values were compared with values resulting from a 109Cd-saturation-assay. When various liver samples of different pathogenesis were compared, the highest level of Cu-MT was found in primary biliary cirrhosis.

Objectives. This study was conducted to examine the assessment of abrasion of two different materials after neutron activation.Methods. A fissure sealant material (Fissurit F/VOCO with a compressive strength of 235 MPa) and a glass ionomer cement (Aqua Ionofil/VOCO with a compressive strength of 170 MPa) were activated by irradiation with neutrons. Subsequent measurements of the full-energy-peak (FEP) (1368.55 keV of Na-24) were mode of the sample materials before and after abrasion via exposure to the air-powder polishing to accurately describe substance loss.Results. Abrasion varied more than three-fold between the two materials.Significance. Neutron activation and radiotracer measurement allows the quantification of abrasion effects in different materials. in comparison with other current methods its use may allow a superior measurement accuracy and precision in determining the abraded mass. (C) 1999 Academy of Dental Materials. Published by Elsevier Science Ltd. All rights reserved.

The aim of this work was twofold: to study the binding pattern of trace elements in formulas as compared with breast milk and the relationship between trace elements in breast milk and in maternal dietary intake. To investigate the binding form of trace elements in these nutritive fluids, methods for protein separation were combined with methods for trace element determination in the eluted fractions. HPLC and ICP-AES or ICP-MS were coupled on-line for the simultaneous speciation of elements of nutritional interest, viz., Ca, K, Mg, P, S, Co, Cu, Fe, I, Mn, Mo, Se and Zn, and also the heavy metals Cd and Pb in both human mild whey and formulas. In order to minimize interactions between the labile metal protein complexes and the column material, size-exclusion chromatography was used for protein separation. The binding pattern of trace elements in formulas is significantly different from that in breast milk and depends on its main component (cow's milk or soy), its processing (hydrolysis) and the chemical form (inorganic) of the added compounds. For example, compared with breast-fed infants the iron supply of formula-fed infants is much higher (up to 20-fold); in addition, the binding forms of Fe are very different in the two fluids. This has to be evaluated with respect to interactions with other elements during intestinal uptake. The investigation of breast milk samples from different regions of the world showed comparable shapes for teh elution profiles and for Mo and Se a dependence on the regional maternal dietary intake. Speciation studies carried out on breast milk samples as a function of the selenium content showed significant changes in the zinc-binding pattern. In particular, citrate (as a zinc-binding component) was found to decrease with increasing dietary selenium intake of the mother.

Because there is a lack of data on blood and tissue levels in acute Cd poisoning we investigated a case of suicidal Cd intoxication with fatal outcome. The male patient survived 9d in the ICU. Kidney, adrenal gland, heart, liver, lung, spleen muscle, small intestine, colon, testis, pancreas, salivary gland, thyroid and brain collected at autopsy was analysed by atomic absorption spectrometry (Cd,Se), neutron activation analysis (Cd,Co,Fe,Rb,Se,Zn) and mass spectrometry using inductively coupled plasma (Cd, Se, Zn, Pb). As a reference Cd was determined in liver, kidney heart, lung and peripheral muscle tissues from subjects (non-smoker and smoker) who died as consequence of cardiogenic shock. The Cd-ingestion resulted in blood levels a factor 1740 higher than normal. The highest Cd-concentrations were found in kidney (200 mg/kg dry), liver and pancreas followed by thyroid spleen and heart (range 25-50 mg/kg dry). On the other hand, the accumulation rate was highest in heart tissue (factor 737) followed by lung (135) liver (98), thyroid (42) and skeletal muscle (28) when compared with the none-smoker group. Because of the high accumulation in myocardium, cardiotoxicity of cadmium might be considered. Quality control was carried out by comparing the results of the independent analytical methods and the analysis of certified reference material.

Instrumental Neutron Activation Analysis was used in order to measure iodine, selenium and zinc concentration in thyroid samples. A pair of samples of normal and nodular tissue were collected from the thyroid gland from 72 patients selected on the basis of pathological criteria (44 cases of multinodular goiter, 12 of chronic lymphocytic thyroiditis (CLT), 6 of thyroid adenoma (TA) and 12 of thyroid cancer (TC)). The check for tissue homogeneity and sampling error was performed by means of the coefficient of variation (CV%) of the elements in replicate samples of normal and altered tissues. High CV% values (> 15%) for iodine reflected a functional variability in thyroid follicles, while low CV% values (< 10%) for selenium and zinc indicated that the composition of selected tissues was rather homogeneous. The variation of the element's concentration was compared in normal and altered tissues. The mean element concentrations had values close to those already reported in the literature; furthermore, our patients had marginal iodine and selenium deficiency. Both normal and nodular tissues in CLT showed statistically significant lower zinc values as compared with the other thyroid diseases. To evaluate the thyroid function, thyroid stimulating hormone (TSH) and thyroxine (T-4) levels were measured in the serum of patients. Two arbitrary serum-TSH threshold levels (TSH < 1.0 and > 4.0 mU/L) were introduced in order to classify, respectively, hyperthyroidism and hypothyroidism, as well as euthyroid conditions (1.0 < TSH < 4.0 mU/L), and each patient was assigned to one of these groups. The influence of TSH in the Variation of the concentration of iodine, selenium and zinc in normal and altered human thyroid tissues was significant.

To study the health effects of high dietary maternal selenium intake breast milk, blood and toe-nails were collected from 143 women (20-24 day of lactation) living in the Venezuelan states of Yaracuy and Portuguesa. Depending on the regional selenium intake level three regions were defined within the total range of 90-980 μg per day. The samples were analyzed by means of INAAfor the determination of trace elements, including selenium and zinc. The significant inverse correlation between Se and Zn in breast milk found in former studies was confirmed. Investigation of the Zn-binding pattern in milk whey was carried out by an on-line combination HPLC (SEC) for protein separation and ICP-AES for element detection. Six Zn-binding compounds including citrate were detected. A highly significant negative correlation was found between the citrate, which is the main low-molecular Zn-binding compound, and the maternal daily selenium intake. We determined that the decrease in zinc concentration is due to a decrease in the citrate level, which depends on the selenium concentration in breast milk. The selenium concentration in breast milk is, in turn, proportional to the dietary intake. In addition, significant changes in the UV- and Zn-profiles were observed in the milk whey with the highest selenium content, indicating that above a certain maternal intake level substantial changes in the composition of mammary secretory cells occur. This effect can be of interest for estimation of the safe dietary intake level of selenium.

High selenium concentrations (7-12 g/kg dry mass) were found in the seeds of the selenium-accumulator plant coco de mono (Lecythis ollaria). In order to obtain information on the protein-bound part of selenium in extracts of these seeds, dialysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) were used combined with neutron activation analysis. Extractions were carried out at pH 4.5 and 7.5. In both cases about 90 % of the element was dissolved. Of the extracted selenium only 9 % was shown to be firmly bound to proteins at pH 4.5 and 29 % at pH 7.5. For the protein-bound selenium, concentrations of 0.7 g and 2.4 g per kg of seeds and 40 and 25 g per kg of extractable protein were determined at pH 4.5 and 7.5, respectively. By analyzing the protein fractions separated by SDS-PAGE the element was found to be present in extremely selenium-rich proteins with molecular masses below 20 kDa.

BACKGROUND:For patients with disturbed aluminum (Al) excretion, a high Al intake is not without risk. As main aluminum sources infusion solutions and solutions for parenteral nutrition have been identified. This study will give current survey of aluminum loading of the above-mentioned preparations.MATERIAL AND METHODS:The aluminum loading of 139 different infusion solutions and solutions for parenteral nutrition was determined. The solutions were from the clinical pharmacy of the Klinikum Steglitz of the Free University Berlin or were bought in a public pharmacy. The aluminum content was determined by means of two different, independent analytical methods: a) graphite furnace atomic absorption spectroscopy (GFAAS) and b) inductively coupled plasma atomic emission spectroscopy (ICP-AES). The agreement of the measured values was good except for five samples, where different values were found. Mistakes due to contamination were excluded on the basis of the results of measuring standard reference materials.RESULTS:Small-volume additives of TPN (total parenteral nutrition) formulations were highly contaminated with aluminum, e.g. Ca and phosphate solutions (29-12,000 micrograms/l), vitamin C solutions (700-1,200 micrograms/l) and trace element solutions (67-6,200 micrograms/l). Furthermore about 44% of the crystalline amino acid solutions and lipid emulsions had an aluminum content of 25 to 55 micrograms/l. Low aluminum levels were found in carbohydrate solutions, NaCl and KCl solutions and in distilled water (aqua ad injectabilia).CONCLUSIONS:Many of the solutions for parenteral nutritional support have an aluminum content which exceeds, in part considerably, the suggested threshold concentration of 25 micrograms/l (0.93 mumol/l), recommended by the American Society for Clinical Nutrition (ASCN) and the American Society for Parenteral and Enteral Nutrition (ASPEN). The pharmaceutical industry should be required to check the manufacturing process for avoidable sources of contamination, and threshold values for aluminum loading by intravenously applied pharmaceuticals should be laid down in the German and European pharmacopoeia. In cases where contaminations cannot be eliminated during the manufacturing process after careful checking, the aluminum content of the infusion solution should be declared for the user.

The Enschi district in Hubei province, Peoples Republic of China is geochemically one of the two seleniferous regions, producing both selenium (Se) black tea and the Se green tea. Three samples of green tea with different Se contents and one non-Se tea were analysed. The following mineral and trace elements were determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES): K, Ca, Mg, Na, P, S, Al, Mn, Fe, Ba, Sr, Co, Ni, Cu, Zn, Mo, and Cr. Except for Mo, Co, and Cr, all other elements in infusions of the samples analysed were also measured, since their concentrations are lying over their detection limits. The Se content in the tea samples and in the infusions were measured with graphite furnace atomic absorption spectrometry (GFAAS). The accuracy of Se determination was tested by measuring untreated tea samples with instrumental neutron activation analysis (INAA). The Se content in the measured samples was 1 to 8.5 mug/g. In addition to Se, 17 other elements were measured in the tea samples and 14 others in the infusions. With this data the extractible part of this elements in the infusion were calculated. Up to 10% of the Se was found in a first infusion.

Das Enschi-Gebiet in der Provinz Hubei ist geochemisch eine der beiden selenreichen Regionen Chinas. Hier werden die grünen und schwarzen Selen-Tees produziert. Drei Proben eines grünen Tees mit verschieden hohen Se-Gehalten sowie eine selenarme Probe wurden in dieser Arbeit untersucht. Die Mineralstoffe und Spurenelemente K, Ca, Mg, Na, P, S, Al, Mn, Fe, Ba, Sr, Co, Ni, Cu, Zn, Mo und Cr wurden mittels Atomemissionsspektrometrie mit induktiv gekoppelter Plasmaanregung (ICP-AES) bestimmt. Außer Mo, Co und Cr wurden alle oben genannten Elemente in den Aufgüssen der untersuchten Selen-Tees ebenfalls mit der ICP-AES gemessen. Die Se-Gehalte in den Teeproben sowie in den Aufgüssen wurden mit Graphitrohr-Atomabsorptionsspektrometrie (GFAAS) bestimmt. Zur Kontrolle der Richtigkeit der Se-Messung wurden die Se-Gehalte in unaufgeschlossenen Teeproben zusätzlich mit instrumenteller Neutronenaktivierungsanalyse (INAA) bestimmt. Es wurden Se-Gehalte im Bereich von 1 bis 8,5 μg/g Trockengewicht gemessen. Außer Se wurden insgesamt 17 Elemente im Tee und 14 in dessen Aufguß quantitativ bestimmt. Daraus wurde der Auslaugungsgrad für die einzelnen Elemente berechnet. Bis zu 10% des Se konnten in einem ersten Aufguß ausgelaugt werden.

Boron carbide (B4C) and boron nitride (BN) irradiation filters have been constructed and used for epithermal neutron activation analysis of biological materials. The major advantage offered by these filters in this application is the substantial reduction of interfering matrix activities. Consequently some trace elements of interest can be determined instrumentally with minimum delay. The filters are particulary beneficial if utilized in short reactor irradiations for rapid analysis of biological materials.