Sergio Costantini

Serum selenium concentration and disease progress in patients with HIV infection

The selenium concentration in the serum of 67 patients with HIV infection was measured to determine whether selenium deficiency occurred in the different stages of the disease. In the first stage of the study, patients were divided into four groups: symptom-free subjects, PGL (persistent generalized lymphadenopathy), ARC (AIDS related complex), and AIDS (acquired immunodeficiency syndrome). Selenium concentrations were normal in HIV antibody positive symptom-free subjects (1.18 +/- 0.27 mumol/L) and lower than normal in the other three groups (p less than 0.001). There was a significant correlation (p less than 0.001) between selenium levels and values of hemoglobin and erythrocyte sedimentation rate. Selenium deficiency was in no case associated with a lack of zinc in serum (also determined in all patients). In the second stage of the study, 12 patients were treated for a period of two months with low doses of selenium to assess whether such supplementation was able to restore their impaired immunological and hematological functions. The therapy increased serum selenium concentrations (from 0.77 +/- 0.23 to 1.44 +/- 0.41 mumol/L) and symptomatic improvements were noted. However, no changes were observed in the immunological and hematological parameters.

Renal Osteodystrophy in Predialysis and Hemodialysis Patients: Comparison of Histologic Patterns and Diagnostic Predictivity of Intact PTH

Background: Comparison of renal osteodystrophy in predialysis and hemodialysis has been rarely reported. Distinct patterns of renal osteodystrophy could be found in these conditions. In addition the use of parathyroid hormone (PTH) and other markers for noninvasive diagnosis may result in different predictive values in predialysis and hemodialysis patients. Methods: 79 consecutive patients with conservative chronic renal failure and 107 patients on hemodialysis were studied. All patients were subjected to bone biopsy for histological and histomorphometric evaluation. The patients had no exposure to aluminium before dialysis and relatively low exposure while on hemodialysis. Results: In the predialysis patients, bone biopsies showed 9 cases of adynamic bone disease (ABD) and 8 cases of osteomalacia (OM), 50 patients with mixed osteodystrophy and 2 cases of hyperparathyroidism. Among the hemodialysis patients 12 cases had ABD, 3 cases OM, 30 mixed osteodystrophy, and 61 patients hyperparathyroidism. In the predialysis patients with chronic renal failure, bone aluminium was on average 4.5 mg/kg dry weight, while in dialysis patients the average value was 35.4 mg/kg dry weight. Discriminant analysis of low turnover osteodystrophy (ABD and OM) by intact PTH showed higher accuracy in dialysis than in predialysis patients. Correlation studies of intact PTH versus bone formation rate, osteoblast surface/bone surface and osteoclast surface/bone surface showed significantly steeper slopes in dialysis than in predialysis patients, which indicates that bone resistance to PTH is more marked in predialysis patients. Conclusions: The prevalence of ABD and OM in the geographic area investigated is lower than in other reports. Aluminium exposure does not seem to be the cause of low turnover osteodystrophy in the present population. The predictive value of intact PTH in the noninvasive diagnosis of renal bone disease is higher in hemodialysis patients than in predialysis patients. Predialysis chronic renal failure, when compared to the dialysis stage, seems to be characterized by resistance of bone tissue to PTH.

Heavy metals in mussels and fish from Italian coastal waters

Abstract Concentrations of mercury, cadmium and lead were determined in the soft tissue of four types of marine organisms (Mytilus galloprovincialis Lmk., Murex trunculus, Serranus scribal and Serranus cabrilla), collected along the Italian coasts from Genoa (Ligurian Sea) to Termoli (Adriatic Sea) in the summer of 1986. The analyses were performed by the electrothermal (cadmium and lead) and cold vapour (mercury) atomic absorption techniques. Levels of metals in Mytilus galloprovincialis were for the most part low, except at a few sites. Murex trunculus contained higher mean concentrations of mercury and cadmium and lower concentrations of lead. In Serranus scriba and Serranus cabrilla, mean levels of mercury were 316±154 and 181±86 μg l−1 fresh weight, respectively, and the levels of cadmium and lead were generally below the detection limits calculated for both these elements.

Determination of cadmium, chromium, lead and vanadium in six fish species from the Adriatic Sea

Concentrations of cadmium, chromium, lead and vanadium were determined in samples of six fish species collected along the coast of the Adriatic Sea. The concentrations of the elements studied were generally low, often below the detection limits of the analytical methods. The highest values (µg kg−1 fresh weight) were observed, mainly in the central area of the Adriatic Sea, for anchovy (Cd 20.2, Cr 82.9, Pb 45.9, V 89.9), red mullet (Cd 3.1, Cr 31.0, Pb 36.0, V 79.1) and mackerel (Cd 7.7, Cr 28.0, Pb 11.4, V 43.5). The concentrations of cadmium and lead in all the species examined were below the maximum levels indicated by the European Community for these two elements in seafood, and also would lead to exposure levels lower than the provisional tolerable daily intakes suggested by the FAO/WHO for Cd (420 µg week−1 for a 60-kg person) and Pb (1500 µg week−1 for a 60-kg person). The concentration of chromium was lower than the recommended daily amount (50–200 µg day−1 for a 60-kg person) indicated by the US National Research Council. An 11–34% contribution to the daily vanadium ingestion with fish was calculated for the population of the Adriatic coast.

Total contents and sequential extractions of mercury, cadmium, and lead in coastal sediments

Samples of sediments collected along Italian coasts were analysed for mercury, cadmium, and lead contents by means of atomic absorption spectrometry methods. Determinations of iron and organic carbon were also performed. In addition, selective extractions were applied to the samples in order to evaluate the presence of the elements investigated in different chemical fractions. The mean values of total metals, expressed on the basis of dry weight, were 0.23±0.41 mg kg−1 for Hg, 0.16±0.12 mg kg−1 for Cd, and 41.1±37.3 mg kg−1 for Pb. In general, the levels of metals found in the stations where there was not much shipping activity were quite low and typical of unpolluted coastal sediments, whereas the highest concentrations noted were in the stations placed inside harbours. The procedure of selective extractions evidenced high percentages of metals in the residual fraction. For lead and cadmium, the concentrations obtained through leaching showed the anomaly/background contrast better than the total concentrations.

Metals contained and leached from rubber granulates used in synthetic turf areas

The aim of this study was to quantify metals contained in and leached from different types of rubber granulates used in synthetic turf areas. To investigate the total content of metals, ca 0.5 g of material was added with HNO(3), HF and HClO(4) and microwave digested with power increasing from 250 W to 600 W. Leachates were prepared by extraction of about 5.0 g of material at room temperature for 24 h in an acidic environment (pH 5). Leaching with deionized water was also performed for comparison. Aluminium, As, Ba, Be, Cd, Co, Cr, Cu, Hg, Fe, Li, Mg, Mn, Mo, Ni, Pb, Rb, Sb, Se, Sn, Sr, Tl, V, W and Zn were quantified by high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) and ICP optical emission spectrometry (ICP-OES). Results indicated that the developed method was accurate and precise for the multi-element characterization of rubber granulates and leachates. The total amount and the amount leached during the acidic test varied from metal to metal and from granulate to granulate. The highest median values were found for Zn (10,229 mg/kg), Al (755 mg/kg), Mg (456 mg/kg), Fe (305 mg/kg), followed by Pb, Ba, Co, Cu and Sr. The other elements were present at few units of mg/kg. The highest leaching was observed for Zn (2300 microg/l) and Mg (2500 microg/l), followed by Fe, Sr, Al, Mn and Ba. Little As, Cd, Co, Cr, Cu, Li, Mo, Ni, Pb, Rb, Sb and V leached, and Be, Hg, Se, Sn, Tl and W were below quantification limits. Data obtained were compared with the maximum tolerable amounts reported for similar materials, and only the concentration of Zn (total and leached) exceeded the expected values.

Applicability of anodic-stripping voltammetry and graphite furnace atomic-absorption spectrometry to the determination of antimony in biological matrices: a comparative study

Both anodic-stripping voltammetry (ASV) and graphite furnace atomic-absorption spectrometry (ETA-AAS) were used to measure levels of antimony in biological samples such as whole blood, urine and mosquito larvae. Depending on the kind of sample or technique used, the sample treatment consisted of an acid digestion or simple dilution with water. In ASV determination, interferences from foreign ions (Cu, Fe and Zn) were studied. In ETA-AAS, different furnace programmes and different types of graphite tubes were tried. The calibrations were always performed both by running adequate antimony standards and by the standard additions method.

Evaluation of aluminium concentrations in samples of chocolate and beverages by electrothermal atomic absorption spectrometry.

Samples of chocolate, cocoa, tea infusions, soft drinks and fruit juice have been examined by electrothermal atomic absorption spectrometry (ETA-AAS) for the presence of aluminium (Al). Fruit juices and chocolate were analysed after an adequate sample preparation; the other products were evaluated directly. Sampling was performed in duplicate for 248 independent samples. The mean Al concentration in chocolate was 9:2 ± 7:5 mg kg1, and individual values were correlated with the per cent of cocoa in samples (Y = 0:63 + 0:27X, r = 0:78, p < 0:0001). Al concentration in commercial tea infusions ranged from 0.9 to 3.3 mg l-1 (X = 1:80 ± 65 mg l-1), whereas in laboratory-prepared samples it was 2:7 ± 0:93mg l-1. In soft drinks, the concentrations of Al were lower, ranging from 9.1 to 179 μgl-1; the highest values were observed in samples of orange squash (X = 114 ± 56 μg l-1). Apricot juice showed the highest Al level (X = 602 ± 190 μgl-1), being statistically diOEerent from that of pear (X = 259 ± 102 μgl-1), but not diOEerent from that of peach juice (X = 486 ± 269 μgkg-1). Toxicologically, the amount of Al deriving from the consumption of these products is far below the acceptable daily intake of 1mg kg-1 body weight indicated by the FAO/WHO, and it is a very low percentage of the normal Al dietary intake.

Rapid determination of plasma ammonia using an ion specific electrode.

A method for measuring directly the ammonia concentration in plasma by the use of an ammonia gas sensitive electrode is proposed. The plasma pH is brought to a final value of 10.4; at which pH, no NH3 is released from other sources and the amount of NH3 measured is 92% of the total ammonia (pKa = 9.3). The potentiometric readings of the samples are referred to a standard curve. In normal subjects, the mean values of venous ammonia nitrogen are 23.9 ± 9.6 (SD) μg/100 ml of plasma. Reproducibility is ± 0.5 mV, or 2%. The method was also compared to the ion exchange method: The difference was constantly below 3%. The time required for the assay is less than 10 min. The method, when compared to others adopting the same electrode, is recommended for its simplicity, accuracy, and rapidity.

Major and trace elements in sediments from Terra Nova Bay, Antarctica

The concentrations of trace metals (Be, Bi, Cd, Cr, Mn, Ni, Pb, Sn, Zn), aluminium, iron and total organic carbon (TOC) were determined in sediments collected in Antarctica (Terra Nova Bay—Ross Sea). Samples were analysed by atomic absorption spectrometry with either flame or flameless techniques. Chemical data were evaluated taking into account the textural and compositional character of the sediments. The mean concentration levels of the elements in the <2 mm granulometric fraction were (mg/kg): Be: 2.04±0.25; Bi ≤0.8; Cd: 0.26±0.16; Cr: 20.3±8.3; Mn: 359±108; Ni: 6.31±3.5; Pb: 20.7±2.8; Sn: 2.12±0.71; Zn: 42.3±10.4; Al: 56 100±3900; Fe: 16 400±4800. The mean value of TOC was 0.34±0.20 g%. In the <63 μm fraction higher levels were observed for all the elements, with the exception of Al and Be. Both petrographic and chemical analyses showed differences between the samples collected in Terra Nova Bay and the sample from Wood Bay.