Prevalence Of Lead Research Articles

Effects of food-borne cholesterol supplementation on lead-induced neurodevelopmental impairments of rats based on BDNF signaling pathway and cholesterol metabolism

Despite the ubiquity and prevalence of lead (Pb) in the environment and industry, the mechanism of lead-induced neurotoxicity in the brain remains unclear, let alone its prevention and treatment. In this study, we hypothesized that exogenous cholesterol supplementation acts as an effective remedy for lead-induced neurodevelopmental impairments caused by lead. Forty 21-day-old male rats were randomly divided into four groups and administered 0.1 % lead water and/or 2 % cholesterol-containing feed for 30 d. Ultimately, rats in the lead group lost weight, accompanied by spatial learning and memory impairments as verified by the Morris water maze test, in which the escape latency of rats was prolonged, and the number of crossings in the target platform and the residence time in the target quadrant were significantly diminished compared to the control group. Hematoxylin-Eosin (H&E) staining and Nissl staining illustrated that typical pathological morphology occurred in the brain tissue of the lead group, where the tissue structure was loose, the number of hippocampal neurons and granulosa cells decreased significantly and were arranged loosely, along with enlarged intercellular space, light matrix staining, and decline in Nissl bodies. In addition, inflammatory response and oxidative stress were significantly induced by lead. Immunofluorescence experiments showed apparent activation of astrocytes and microglia, followed by the enhancement of TNF-α and IL-β levels. Moreover, the MDA content in the lead group was elevated dramatically, whereas the activities of SOD and GSH were significantly inhibited. As for the mechanism, western blot and qRT-PCR experiments were performed, where lead could significantly inhibit the BDNF-TrkB signaling pathway, lowering the protein expression of BDNF and TrkB. Cholesterol metabolism was also affected by lead exposure, in which cholesterol metabolism-related protein expression and gene transcription, including SREBP2, HMGCR, and LDLR, were downregulated. However, cholesterol supplementation efficiently detoxified the negative effects of lead-induced neurotoxicity, reversing the inflammatory response, oxidative stress, inactivation of the BDNF signaling pathway, and imbalance of cholesterol metabolism, thus improving the learning and memory ability of rats. In brief, our study demonstrated that cholesterol supplementation could ameliorate the deficiency of learning and memory induced by lead, which is closely associated with the initiation of the BDNF/TrkB signaling pathway and regulation of cholesterol metabolism.

Investigation of changes in rat’s blood metabolomic profile, caused by lead exposure

Introduction. The prevalence of lead in the environment, due to human production and economic activities, and the xenobiotic nature of the element substantiate the relevance of studying the changes caused by the action of this metal. Materials and methods. A non-target metabolomic screening of the blood of rats exposed to intraperitoneal administration of lead acetate by HPLC-mass spectrometry was carried out. The expression of the selected masses was compared with those for the control group of animals. The masses that significantly changed the intensity compared to the control were subjected to fragmentation to obtain characteristic fragments. The annotation of metabolites was performed by searching in MS/MS databases and by comparison with in silico fragmentation spectra. The involvement of annotated metabolites in metabolic processes was established by literature analyzing. Results. Non-target metabolomic screening revealed 37 m/z values for the exposed group, significantly changing the intensity compared to the control. Annotation using fragmentation spectra and in silico fragmentation allows establishing the structure of eight metabolites, including an epoxy derivative of linolic acid, 15-hydroxyeicosatetraenoic acid, four oxo- and hydroxyacylcarnitine derivatives of long-chain fatty acids, one acylcarnitine derivatives of medium-chain fatty acids and one lysophosphoserine. Conclusion. Analyzing the literature, the known functions of the identified metabolites were established and attributed to the known metabolic processes. So, oxo- and hydroxyacylcarnitines are derivatives for intermediate products of β-oxidation fatty acids - it is increased concentration compared to the control indicates a violation of this process under the influence of oxidative stress caused by lead. Epoxy and 15-hydroxy derivatives of fatty acids (increased content relative to the control group) act as regulatory metabolites (vasodynamic activity), on the one hand, and markers of lead-induced hypoxia on the other hand. The increase of the concentration for the lysophosphatidylserine derivative indicates the intensification of apoptotic processes in the organism of the exposed group in contrast to the control.

Development and validation of a risk score model for prediction of lower extremity arterial disease in Chinese with type 2 diabetes aged over 50 years.

BackgroundLower extremity arterial disease (LEAD) is highly prevalent in people with diabetes in China, but half of cases are underdiagnosed due to diversities of clinical presentations and complexities of diagnosis approaches. The purpose of this study was to develop a risk score model for LEAD to facilitate early screening among type 2 diabetes (T2DM) patients.MethodsA total of 8313 participants with T2DM from the China DIA-LEAD study, a multicenter, cross-sectional epidemiological study, were selected as the training dataset to develop a risk score model for LEAD by logistic regression. The area under receiver operating characteristic curve (AUC) and bootstrapping were utilized for internal validation. A dataset of 287 participants consecutively enrolled from a teaching hospital between July 2017 and November 2017 was used as external validation for the risk score model.ResultsA total of 931 (11.2%) participants were diagnosed as LEAD in the training dataset. Factors including age, current smoking, duration of diabetes, blood pressure control, low density lipoprotein cholesterol, estimated glomerular filtration rate, and coexistence of cardio and/or cerebrovascular disease correlated with LEAD in logistic regression analysis and resulted in a weighed risk score model of 0–13. A score of ≥5 was found to be the optimal cut-off for discriminating moderate–high risk participants with AUC of 0.786 (95% CI: 0.778–0.795). The bootstrapping validation showed that the AUC was 0.784. Similar performance of the risk score model was observed in the validation dataset with AUC of 0.731 (95% CI: 0.651–0.811). The prevalence of LEAD was 3.4, 12.1, and 27.6% in the low risk (total score 0–4), moderate risk (total score 5–8), and high risk (total score 9–13) groups of LEAD in the training dataset, respectively, which were 4.3, 19.6, and 30.2% in the validation dataset.ConclusionThe weighed risk score model for LEAD could reliably discriminate the presence of LEAD in Chinese with T2DM aged over 50 years, which may be helpful for a precise risk assessment and early diagnosis of LEAD.

Impact of lead acetate and sodium and potassium stearates on lipid peroxidation processes in the body of experimental animals

Introduction. Given the significant prevalence of lead in the environment, research in this area has significant social and economic importance. Lead compounds are characterized by high toxicity and increased ability to cumulate in ecosystems, humans, and animals. Lead enters the human body with food, drinking water, atmospheric air, and smoking. Lead causes pathological changes in the nervous system, blood-forming organs, kidneys, etc. Materials and methods. The experiments were carried out on four groups of white female rats, each included seven animals, weighing 150-200 g. The first group of animals was a control. The second group consumed dechlorinated water from the city water supply, followed by lead acetate. The animals from the third and fourth groups drank the same water with sodium stearate and potassium stearate content in a dose of 1/250 LD50. After the 40th-day of the use of these waters, the animals were orally administered lead acetate at a dose of 7 mg/kg. The levels of lipid peroxidation biomarkers were studied by studying the content of diene conjugates (DC) and malondialdehyde (MDA) in blood serum, liver, and kidney homogenates. Results. The administration of 1/2 acetate LD50 to lead in experimental rats drinking water with stearates was accompanied by a significant increase in the DCs concentration and (MDA) in animals. Higher concentrations of LPO products were observed in the group of animals that consumed water from potassium stearate. Conclusions. 1. With the oral administration of lead acetate against the background of drinking water containing stearates at a dose of 1/250 LD50, an increase in lipid peroxidation indices was noted compared with the control group. 2. Higher concentrations of LPO products were observed in the group of animals consuming water from potassium stearate.

Calcium and Lead Levels in the Biological Samples and Their Effect on the Biochemical Parameters of Indoor and Outdoor Workers of Five Zonal Areas of Coal Mining Field

Workers of the Lakhra coal mining Sindh Pakistan were affected by a multi-factorial exposure of heavy metals. The prevalence of lead (Pb) exposures in work-related symptoms among workers of indoor and outdoor mining of Lakhra coal mining was evaluated in detail. The biological samples (scalp hair and blood) of 270 workers of Lakhra coal mining {official and control subjects} (indoor and outdoor) 18 to 55 years age group and 70 referent subjects of same age-groups were examined. The biological samples (blood and scalp hair) of workers of Lakhra coal mining and referent subjects were analyzed for calcium (Ca) and lead (Pb). Flame atomic absorption spectrometry was applied for the determination of the Ca in digested samples of studied subjects by the microwave oven whereas, the Pb contents were measured by electrothermal atomic absorption spectrometry. The validity of the methodology was checked by using the certified human hair material (BCR 397) and lyophilized human blood (Clincheck). The results indicated the higher contents of Pb in biological samples of indoor and outdoor mining workers than referents. However, the levels of Ca were found to be lower in indoor and outdoor mining workers than those of referents. It can be concluded that immediate action should be taken by recommended authorities to improve the ventilation and hygiene practices inside the industries, mines, and other workplaces.

Determination of size-segregated elements in diesel-biodiesel blend exhaust emissions.

This study was based on the determination of metals in particulate matter emitted by a typical diesel engine used by busses and trucks in Brazil. Emissions were sampled using a cascade impactor, and the engine was operated using diesel with 5% (B5), 10% (B10), 15% (B15), and 20% (B20) of biodiesel. The particulate matter was stratified in different sizes, i.e., 18, 5.6, 3.2, 1.8, 1.0, 0.560, 0.320, 0.180, 0.100, and 0.056μm. Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, V, and Zn with concentrations within 10 to 1000ngm-3 were determined. The results indicate a trend in the prevalence of lead, nickel, and chromium in coarse particles and nanoparticles in all blends of fuels. By comparing the results of B5, B10, B15, and B20 fuels, we can confirm that the addition of biodiesel to diesel promotes a reduction of emissions, and by comparing the behavior of the concentration of all elements analyzed, emissions by B10 and B15 fuels are similar, while B5 and B20 suffer significant changes during the process of combustion. Multivariate statistical analysis was used, and it indicates possible sources in three clusters, one for Ni, other for Cr-Mn, and the last one for other metals.

The evolution of electrocardiographic changes in patients with Duchenne muscular dystrophies.

PurposeMyocardial dysfunction and dysrhythmias are inevitable consequences of Duchenne muscular dystrophy. We aimed to evaluate specific trends of electrocardiographic changes that reflect the progress of cardiomyopathy in patients with Duchenne muscular dystrophy.MethodsFifty electrocardiograms (ECGs) of 30 patients (ages 1 to 27 years) who had not been prescribed medications for heart failure treatment at the time of examination were retrospectively analyzed and compared with 116 ECGs of age-matched healthy 116 controls. Heart rate, leads with fragmented QRS (fQRS), corrected QT, Tpeak-to-Tend, and Tpeak-to-Tend/QT were analyzed.ResultsThe patients with Duchenne muscular dystrophy failed to show a normal age-related decline in heart rate but showed an increasing trend in the prevalence of fQRS, corrected QT, corrected Tpeak-to-Tend, and Tpeak-to-Tend/QT over time. In the ≤10-year-old patient group, a significant difference was found only in the prevalence of fQRS between the patients and the controls. The prevalence of fQRS, heart rate, Tpeak-to-Tend/QT, and corrected Tpeak-to-Tend demonstrated significant differences between the patients and the controls in the middle age group (11 to 15 years old). All the indexes were statistically significantly different in the ≥16-year-old patient group.ConclusionThe prevalence of lead with fQRS representing regional wall motion abnormalities was higher in the young patients than in the young healthy controls, and this might be one of the first signs of myocardial change in the patients. Markers of depolarization and repolarization abnormalities were gradually prominent in the patients aged >10 years. Further studies are needed to confirm these findings.

Detection of Lead (Pb), Cadmium (Cd), Chromium (Cr) Nickel (Ni) and Magnesium Residue in Kidney and Liver of Slaughtered Cattle in Sokoto Central Abattoir, Sokoto State, Nigeria

Abstract The prevalence of lead, cadmium, chromium, nickel, and magnesium in liver and kidney samples of slaughtered cattle at Sokoto abattoir was determined using Atomic Absorption Spectrophotometer. A total of twenty four samples were collected for analyses. Among the samples 19, 21, 23, 16, and 24 were positive for Lead, cadmium, chromium, nickel, and magnesium respectively. The mean concentration of lead, cadmium, chromium, nickel, and magnesium in liver of the slaughtered cattle were 1.523 mg/kg, 2.687 mg/kg, 4.775 mg/kg, 0.938 mg/kg, and 76.167 mg/kg respectively, while the mean concentration of Lead, cadmium, chromium, nickel, and magnesium in kidney of slaughtered cattle were 0.8442 mg/kg, 2.058 mg/kg, , 4.894 mg/kg, 0.772 mg/kg, and 68.258 mg/kg respectively. There was significant difference in the concentration of lead, cadmium, chromium, nickel and magnesium in liver and kidney of slaughtered cattle (P< 0.05). The mean concentration of lead, cadmium, chromium, in both liver and kidney of slaughtered cattle were higher than the permissible limit recommended by Food and Agricultural Organization.

Prevalence of lead (pb) residues in kidney and liver of slaughtered pigs at Sabo-Wakama market of Akun development area of Nasarawa state, Nigeria.

The prevalence of Lead (Pb) in liver and kidney samples of slaughtered pigs at Sabo Wakama Market of Akun-Development Area of Nasarawa State was determined using Atomic Absorption Spectrophotometer. A total of thirty number of samples were collected for analyses and all the samples were positive for Lead residues. The highest and lowest concentration of Lead (Pb) residue in liver and kidney were found to be among the age groups of 0-2 years and those at 3-5 years respectively. There was a significant difference (P< 0.05) in the concentration of Lead in liver and kidney samples of the different age groups of the slaughtered pigs. The mean Lead concentration in liver and kidney of all the age ranges is higher than the maximum permissible level of Lead (0.5 mg/kg) in edible offal of pig recommended by Food and Agricultural Organisation (FAO, 2002). It is therefore obvious that the liver and kidney of the slaughtered pigs at Sabo Wakama Market of Akun-Development Area contain Lead residues. This finding needs an immediate attention of health regulatory authorities and the researchers as well. There is an urgent need of local database or risk assessment studies in local food animals to assess the potential risk to animals and humans from heavy metals residue.

Distribution of the silver in Bulgaria ore deposits

The content of silver in the different, in terms of genesis and macrochemism, endogenic mineralisations in Bulgaria varies from 1-2 to 200 g/t, most frequently 5-35 g/t. The highest concentrations of this element are registered in the West Balkan region (lead-silver ores near Chiprovtsi, gold-sulphide ores near Govezhda and polymetallic ores Iskar-Vratsa ore region as well as Kremikovtsi deposit); in the Central Rhodopes region (lead-zinc deposits in Laki, Madan and Davidkovo ore fields, Ardino silver-polymetallic deposit); in the lead-zinc ores in Ossogovo ore region; in the East Rhodopes ore region (gold-silver-polymetallic ores in Madzharovo ore field and Popsko, silver-gold ores in Sedefche and Sarnak); in the East Srednogorie (gold-copper-polymetallic ores near Bakadzhik and Zidarovo). Some of the more significant favourable geological prerequisites for the accumulation of silver in the ores are: Late Paleozoic or Tertiary (Oligocene-Miocene) age, geodynamic environments of collision and zones with thick earth crust, anticlinoria and big horst-like uplifts, WNW and NW host structures, close to the surface or flange sections of the mineralisations. The mineralisations with higher content of silver are, as a rule, related to granites. Their host rocks are carbonates with development of metasomatic processes such as dolomitisation and granitoids with periore alterations of the quartz-sericite, quartz-mica (beresite), adular-sericite or quartz-adularia metasomatites and argillizites. The composition of the ores includes lithophile-chalcophile geochemical associations with prevalence of antimony. A favourable factor for the accumulation of silver is the lead-zinc macrochemism with prevalence of lead in zones with thick earth crust and the polymetallic - in zones with basificated (subocean type) earth crust. The mineral composition of the ores includes galena, sulphosalt silver minerals, the especially high silver-bearing tetrahedrite-tennantite series with prevalence of tetrahedrite and participation of magnesium and iron carbonates (siderite, ankerite, dolomite). The character of the silver-bearing mineralisations in Bulgaria is medium to low-temperature and, according to their peculiarities, they can be related to the mesothermal, epithermal or telethermal genetic classes.

Gender Differences in Blood Lead and Hemoglobin Levels in Andean Adults with Chronic Lead Exposure

A field study of the prevalence of lead (Pb) intoxication was conducted in 158 adults (67 men and 91 women) living at 2,500-2,800 meters in Ecuadorian Andean villages with high Pb contamination from local small-scale Pb-glazing cottage industries. Venous blood samples showed mean blood lead (PbB) levels of 34.5 microg/dL (SD 22.2) for men and 27.0 microg/dL (SD 18.4) for women; this difference was significant (t-test, p = 0.022; Mann-Whitney U, p = 0.044). An ANOVA showed no significant main effect for gender (F = 0.118, p = 0.782) or age (F = 2.479, p = 0.117), and no significant gender-by-age interaction (F = 0.273, p = 0.602). In the Pb-glazing study group, 39% of the men had PbB levels > or = 40 microg/dL, while 41% of the women had PbB levels > or = 30 microg/dL (the WHO health-based biological limits). A reference group of 39 adults (24 men and 15 women) had a mean PbB level of 5.9 microg/dL (SD 2.8; range: 1.8-16.8), significantly different from that of the 158 subjects in the study group (t-test, p < 0.0001). The difference in mean PbB levels of men (6.8 microg/dL) and women (4.7 microg/dL) in the reference group was significant (t-test, p = 0.026; Mann-Whitney U, p = 0.019). The mean altitude-corrected hemoglobin levels in the study group were lower than normal, 11.3 g/dL for men and 10.9 g/dL for women.

Lead Hazards within the Range of the California Condor

The prevalence of lead in Golden Eagles (Aquila chrysaetos) occurring within the recent historical range of the California Condor (Gymnogyps californianus) was deter- mined by analyzing blood samples from 162 Golden Eagles captured between June 1985 and December 1986 at three sites. We found no significant differences between sex and age classes in blood lead levels nor were there differences between residents and migrants. Significant differences were found between months with the highest blood lead levels oc- curring during the fall/winter period. Approximately one-third (35.8%) of the Golden Eagle population sampled had elevated blood lead levels, values similar to those reported for free- flying California Condors. Given this rate of exposure, if the proposed releases of California Condors back to the wild are to succeed, whether in their former range or elsewhere, any potential for lead poisoning must be reduced. It is essential that we identify the sources of the lead, the seasonal and geographic distribution of these sources, and develop management strategies to reduce or eliminate the hazard.