Association Between Serum Selenium Concentration and OPG/RANKL/RANK Axis in Patients with Arterial Hypertension.

The aim of the study was to determine the relationship between the serum selenium concentration (Se-S) and the blood concentrations of osteoprotegerin (OPG), receptor activator of nuclear factor kappa-Β ligand (RANKL) and the OPG/RANKL ratio in patients with arterial hypertension. The study group comprised 138 patients with arterial hypertension (age: 56.04 ± 11.59 years). Se-S was determined in all the subjects. Based on the Se-S, the following subgroups were distinguished: a subgroup of patients with a lower Se-S ("low-Se", Se-S < median) and a subgroup of patients with a higher Se-S ("high-Se", Se-S ≥ median). Moreover, the blood concentrations of the parameters of bone metabolism and extraskeletal calcification were assessed: OPG and RANKL. The OPG/RANKL ratio was calculated. In the "low-Se" subgroup, the RANKL concentration was statistically significantly lower, and the OPG/RANKL ratio was statistically significantly higher than in the patients in the "high-Se" subgroup. The correlation analysis showed the negative linear relationships between Se-S and OPG (r = - 0.25, p < 0.05) and between Se-S and OPG/RANKL (r = - 0.47, p < 0.05). Moreover, Se-S positively correlated with RANKL (r = 0.33, p < 0.05). In regression analysis, higher body mass index (BMI), smoking and lower Se-S were independently associated with a higher OPG/RANKL ratio, while lower BMI, use of diuretics, ß-blockers and ACE inhibitors and lower OPG/RANKL ratio with effective blood pressure control. In summary, in the group of patients with arterial hypertension, lower Se-S is associated with an unfavourable prognostic panel of parameters of bone metabolism and extraskeletal calcification. Lower Se-S is an independent risk factor for a higher OPG/RANKL ratio, which is an independent prediction factor of ineffective blood pressure control in patients with hypertension.

Total antioxidant status reduction conditioned by a serum selenium concentration decrease as a mechanism of the ultrasonographically measured brachial artery dilatation impairment in patients with arterial hypertension.

The objective of the study was to determine the relationship between serum concentrations of selenium (SeS) and zinc (ZnS), total antioxidant status (TAS) and endothelial function assessed by ultrasonographic method of dilatation of the brachial artery in 141 hypertensive patients. Patients with SeS < median were characterized by a statistically significantly lower flow-mediated dilation (FMD) than patients with SeS ≥ median. Patients with TAS < median were characterized by a significantly lower FMD than patients with TAS ≥ median. Older age, higher BMI, male gender, higher blood total cholesterol, ischemic heart disease, smoking and lower SeS constitute independent predictors of inferior endothelial function, expressed in lower FMD values. Smoking is an independent predictor of lower TAS, and the use of ß-blockers and higher serum selenium levels are independent predictors of higher TAS. In summary, a decrease in TAS should be considered as a mechanism of inferior endothelial function in hypertensive patients conditioned by a decrease in SeS.

Old and New Threats-Trace Metals and Fluoride Contamination in Soils at Defunct Smithy Sites.

The aim of this study was to investigate soil contamination with trace elements and fluoride at sites in Szczecin (NW Poland) where economic activity was historically associated with the use of trace metals. As the Polish legislation does not recognize the lasting impact of historical pollution on soils, land developers are not obliged to determine soil pollution in the new residential areas, including parks and playgrounds for children. Therefore, in this study, at the locations of defunct metalwork enterprises (smithies, foundries, chemical plants, and small metal production plants), which were closed down after World War II, we determined lead (Pb), chromium (Cr), copper (Cu), zinc (Zn), iron (Fe), manganese (Mn), nickel (Ni), mercury (Hg), cadmium (Cd), and cobalt (Co) levels in the soil. In addition, we also determined fluoride (F) levels due to the contemporary fluoride pollution in the area generated by a large chemical plant with a post-production phosphogypsum waste landfill and a power plant complex. Our results show that soil at the sites of now-defunct smithies can still act as a significant source of trace metals. Pb concentration in the surface (0⁻20 cm) and subsurface (20⁻40 cm) layers exceeded concentration thresholds for soils with first-degree pollution. The concentrations of Zn and Cu also exceeded their natural background limits. Furthermore, our research indicates an increased concentration of fluoride in surface layers of the soil; however, not exceeding the fluoride content threshold. These observations have important consequences for public health and safety because, presently, the studied sites function as housing estates and other public facilities. Therefore, contaminated soil at these sites may pose a threat to the health of local residents and should be closely monitored for trace metal contamination levels.

The effects of neat biodiesel and biodiesel and HVO blends in diesel fuel on exhaust emissions from a light duty vehicle with a diesel engine.

The influence of fatty acid methyl esters (FAME) and hydrotreated vegetable oil (HVO) diesel blends on the exhaust emissions from a passenger car was examined. The impact of FAME for the cold urban phase (UDC) was increased CO and HC emissions, probably due to blend physical properties promoting incomplete combustion. The HVO blend caused the lowest CO and HC emissions for the UDC. NOx emissions did not change significantly with the fuel used, however the UDC was characterized by lower NOx emission for FAME blends. Particle emissions were highest with standard diesel. Emissions of carbonyl compounds increased as fuel biodiesel content increased, especially during the UDC. HVO in diesel fuel decreased carbonyl emissions. Formaldehyde and acetaldehyde were the most abundant carbonyl compounds in the exhaust gas. Total particle-bound PAH emissions were variable, the emission of heavier PAHs increased with blend biodiesel content. The HVO blend increased emission of lighter PAHs. Nitro-PAHs were identified only during the UDC and not for all blends; the highest emissions were measured for pure diesel. The results showed that emission of nitro-PAHs may be decreased to a greater extent by using biodiesel than using a HVO blend.

The influence of beta-carotene on homocysteine level and oxidative stress in lead-exposed workers.

BACKGROUND: Oxidative stress is involved in lead toxicity. This suggests that some antioxidants may play a role in the treatment of lead poisoning. In the light of this, the aim of the study was to determine whether beta-carotene administration reduces oxidative stress and homocysteine level in workers chronically exposed to lead. MATERIAL AND METHODS: The exposed population included healthy male workers exposed to lead who were randomly divided into 2 groups (mean blood lead level ca. 44 microg/dl). Workers in the 1st group (N = 49, reference group) had no antioxidants, drugs, vitamins or dietary supplements administered, while workers in the 2nd group (N = 33) had beta-carotene administered in a dose of 10 mg per day for 12 weeks. Biochemical analysis included markers of lead-exposure and the level of malondialdehyde (MDA), an oxidative stress biomarker. We also measured the level of homocysteine (Hcy) and thiol groups as well as the activity of superoxide dismutase (SOD) and its isoenzyme EC-SOD in serum. RESULTS: After supplementation, the level of MDA significantly decreased, compared to baseline, by 16%, and to the reference group. When compared to the reference group, Hcy level was also significantly decreased. However, the level of thiol groups was significantly higher after supplementation with beta-carotene compared to the reference group. Analogically, the activity of SOD and EC-SOD was significantly higher compared to the baseline and to the reference group. CONCLUSIONS: Despite some controversies over antioxidant properties of beta-carotene, our results indicate that its antioxidant action could provide some beneficial effects in lead poisoning independent of chelation.

The effect of occupational lead exposure on blood levels of zinc, iron, copper, selenium and related proteins.

The study objective was to evaluate the effect of occupational lead exposure on blood concentrations of zinc, iron, copper, selenium and proteins related to them, such as transferrin, caeruloplasmin and haptoglobin. The examined group consisted of 192 healthy male employees of zinc-lead works. By the degree of lead exposure, the exposed group was subdivided into three subgroups. The control group was composed of 73 healthy male administrative workers. The markers of lead exposure (blood levels of lead and zinc protoporphyrin) were significantly elevated in the exposed group compared with the control group. Additionally, concentrations of copper and caeruloplasmin were raised. The significant increase in haptoglobin level was observed only in the low exposure group. Selenium levels were significantly decreased, whereas iron, zinc and transferrin levels were unchanged in the exposed group compared with the control group. There were positive correlations between the lead toxicity parameters and the copper and caeruloplasmin levels. In conclusion, the effect of occupational exposure to lead on the metabolism of trace metals appears to be limited. However, significant associations between lead exposure and levels of copper and selenium were shown. Changed levels of positive acute-phase proteins, such as caeruloplasmin and haptoglobin, were also observed.

Blood selenium concentration in a selected population of children inhabiting industrial regions in Upper Silesia (Poland).

PURPOSE: Present study aimed at determining blood selenium concentration (Se-B) in a selected population of children inhabiting industrial regions. METHODS: The studies were conducted on a group of 267 children inhabiting industrial regions in Upper Silesia (Poland). Determination of Se-B was performed using hydride generation atomic absorption technique. RESULTS: In the studied group of children mean Se-B amounted to 76.75±12.52µg/L. Only in 38.20% of studied children the estimated Se-B could be regarded as an optimal. Children with underweight (BMI<15th centile) manifested a significantly lower Se-B than children with BMI within the normal range (BMI 15-85th centile). In the entire study group of children a significant positive linear correlation was disclosed between BMI and Se-B (r=0.16, p<0.05). Regression analysis demonstrated that in the studied subgroup of children (with normal height, body mass and BMI) a higher BMI represented an independent factor of Se-B increase and a more pronounced age an independent factor of Se-B decrease. Moreover, maternal education represented an independent factor of Se-B increase in the studied group of children (with normal height, body mass and BMI). CONCLUSIONS: Se-B in the studied group children from industrial area in Upper Silesia corresponded with the lower range of blood selenium concentrations noted in recent years in other populations. A negative relationship was documented between age and Se-B and a positive relationship between BMI of a child and maternal education on one hand and Se-B of a child on the other.