Blood lead concentration among oral/inhaled opium users: systematic review and meta-analysis.

Lead is a poisonous heavy metal with various known side effects. The effect of opium on raising blood lead concentration (BLC) has been investigated with no general agreement. In Iran, the number of lead poisoning cases has raised among the opium-addicted population. This systematic review and meta-analysis aim to combine the results of previous studies with the Iranian population to investigate the effect of opium on BLC. In this systematic review, PubMed/Medline, Web of Sciences, Embase, and Scopus were searched for studies using the Iranian population to compare the BLC of opium-addicted cases and non-addicted controls till January 2020. A random-effects model was used to pool the results. I-square test was used to assess the heterogeneity of the studies. The effect sizes were standardized mean differences (proxied by Hedges' g) followed by a 95% confidence interval. Of 417 initial articles, 13 studies met the inclusion criteria to be considered in the meta-analysis. The sample size of eligible studies ranged from 40 to 131 (mean 81.83, SD 27.6). All studies were focused on adults with mean age ranged from 33.5 to 65.15 years old (overall mean 49.0, SD 7.66). There were 13 studies included with 18 Hedges' g effect sizes. Using a random effect model, the pooled effect size was gw = 2.48 (95% CI: 1.58-3.39) and statistically significant in favor of opium-addicted participants. Moreover, heterogeneity was 96.6% (I2=96.6, Q(17) = 504.95, p < 0.001). For studies with large Hedges' g effect sizes (> 4) identified as outliers and removed from meta-analysis. The pooled Hedges' g effect size reduced to 1.39 (95% CI: 0.94-1.85), still highly significant in favor of higher levels of lead in the opium-addicted group. The funnel plot appeared symmetrical confirmed by Egger's test (t = 1.87, p = 0.088), indicating no publication bias present.

Biomonitorization of metal ions in the serum of Iranian patients treated with fixed orthodontic appliances in comparison with controls in eastern Iran.

The present study aimed to assess the level of metal ions [chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), and zinc (Zn)] in the serum of patients with fixed orthodontic appliances. One hundred samples (32 males, 68 females) were collected from patients undergoing fixed orthodontic treatment for different periods. A reference (control) group (24 males, 16 females) who had no appliances was used to properly evaluate the changes in the level of these elements in orthodontic appliance users. The element concentrations were measured using inductively coupled plasma mass spectrometry (ICP-MS). Higher concentrations of metal ions (except for Cr) were found in the serum of the orthodontic group. Bivariate scatter plot showed a highly significant (p < 0.001) correlation between Ni and other elements. The duration of orthodontic treatment increased significantly the Ni levels whereas the bracket type was found to have no significant impact on altering the concentration level of metal ions. The results of the SEM-EDS showed a high variation in the level of metal ions in the brackets and wires. In conclusion, fixed orthodontic appliances increased serum levels of Ni, Zn, Mn, Fe, and Cu but did not change Cr levels.

Toxicological effects of transition metal-doped titanium dioxide nanoparticles on goldfish (Carassius auratus) and common carp (Cyprinus carpio).

The aim of present study was to assess the toxicological effects of transition metal-doped titanium dioxide nanoparticles (TiO2 NPs) on histopathological changes, behavioral patterns, and antioxidant responses of goldfish (Carassius auratus) and common carp (Cyprinus carpio). The synthesized nanoparticles were confirmed by Transmission Electron Microscopy, Field Emission Scanning Electron Microscopy, X-ray diffraction, UV-visible, and Vibration Sample Magnetometer. Fish in four experimental groups exposed to sub-lethal concentrations of pure TiO2 NPs (10 mg L-1), chromium (Cr), iron (Fe), and nickel (Ni) doped TiO2 NPs for seven days. Statistical analysis of oxidative stress responses in gills showed significant differences in superoxide dismutase, total antioxidant capacity, and malondialdehyde parameters between two species and in all parameters than glutathione peroxidase between experimental groups and control group. In intestine, no significant difference was observed among groups, but oxidative responses were markedly different in all parameters among fish species. The histopathological analysis showed hyperplasia, fusion, and aneurism in the gills as well as degeneration, integration of villi, necrosis and erosion of the intestine. Our findings indicated that compare to pure TiO2 NPs, exposure to transition metals-doped TiO2 NPs induced oxidative stress and histopathological changes in both fish species.