Ecological risk assessment of heavy metals in urban dust in Iran: A systematic review and meta-analysis.

Background: Heavy metals in street dust are one of the most important sources of pollutants in urban areas. This urban dust can be caused by industrial activities, traffic, erosion of buildings, and fossil fuels. The aim of this systematic review is to evaluate the ecological risk of heavy metals in the dust of Iran's provinces. Methods: This study was conducted in February 2023 in order to investigate the environmental risks associated with heavy metals associated with dust particles in Iran. The present study was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Finally, 9 studies were extracted from the search databases. Results: The ecological risk of heavy metals in the present study was as follows: Cd (258.26؛ CI: 83.53, 433) >Pb (52.58؛ CI: 37.15, 68.02) >Cu (24.44؛ CI: 16.74, 32.14)>Ni (14.75؛ CI: 12.68, 16.82)>As (13.53؛ CI: 10.20, 16.85)>Zn (6.32؛ CI: 3.76, 8.87)>V (3.18؛ CI: 2.65, 3.72)>Cr (2.73؛ CI: 2.19, 3.27)>Co (1.94؛ CI: 1.13, 2.74). The mean ranking of the studied Pb ecological risk is as follows: Shiraz.> Tehran > Ahvaz > Ilam > Abadan > Dezful. Conclusion: The ecological risk potential of Cd in Tehran was also much higher than the standard. Therefore, Tehran was the most polluted city studied in terms of the ecological risk potential of Cd (1611.41؛ CI: 1605.98, 1616.84) and Pb (86.54؛ CI: 71.46, 101.62). The average concentration as well as the ecological risk of Cr, Co, and V metals were lower than the standard. Therefore, controlling the sources of heavy metal emissions (especially lead and cadmium) is highly recommended.

A single injection of vitamin D3 improves insulin sensitivity and ß-cell function but not muscle damage or the inflammatory and cardiovascular responses to an acute bout of resistance exercise in vitamin D-deficient resistance-trained males.

Vitamin D deficiency is now a recognised problem affecting multiple physiological functions. The aim of the present study was to evaluate the effect of a single dose of vitamin D3 injection on the inflammatory, muscular damage, metabolic and cardiovascular responses to an acute bout of resistance exercise (RE) in vitamin D-deficient resistance-trained males. Blood samples from fourteen vitamin D-deficient resistance-trained males were obtained during two separate trials: lower vitamin D (LVD) and higher vitamin D (HVD, after vitamin D3 injection). Metabolic, inflammatory, muscle damage and cardiovascular markers were evaluated at baseline, immediately and 1 h after RE. There were significant trial-by-time interactions for insulin and homeostatic model assessment of insulin resistance (HOMA-IR) which significantly (P < 0·05) declined for 1 h after RE in the HVD trial compared with the LVD trial. Homeostasis model assessment of ß-cell function (HOMA-ß) declines at 1 h post-RE in the HVD trial. There was also a time effect for blood sugar which significantly (P < 0·05) decreased and for creatine kinase, lactate dehydrogenase and IL-6 which increased significantly 1 h post-RE in both trials. There were no significant changes in other inflammatory and cardiovascular markers following both trials. A single injection of vitamin D3 improved insulin resistance and ß-cell function following RE in previously vitamin D-deficient resistance-trained males. Conversely, the injection did not change muscle damage and the inflammatory response to acute RE. Intramuscular vitamin D replacement may have key implications for the promotion of glucose metabolism and lowering the risk of diabetes in vitamin D-deficient individuals.

Evaluation of Antibiotic Susceptibility Pattern and Distribution of coa Genes in Coagulase-negative S. aureus from Ahvaz, Iran.

BACKGROUND: Staphylococcus aureus is one of the important causes of clinical infections that can be more destructive by its antibiotic resistant strains. OBJECTIVE: This study aimed to determine the antibiotic susceptibility pattern and distribution of mecA and coa genes in clinical isolates of S. aureus. METHODS: Two hundred seventy-three specimens suspected to S. aureus were taken from hospitals of Ahvaz, southwest of Iran. Isolates were identified by standard microbiologic tests and confirmed by the molecular method. Antimicrobial susceptibility testing was carried out by disk diffusion method. The presence of mecA and coa genes was determined by PCR method. RESULTS: Of a total of 200 isolates which were tested for coagulase tube test, 143 (71.5%) showed coagulase positive, and 57 (28.5%) showed a coagulase-negative reaction. Antibacterial susceptibility pattern of 200 S. aureus isolates showed the highest and lowest susceptibility rate to linezolid (98%) and ciprofloxacin (42%), respectively. The prevalence of methicillin-resistant S. aureus (MRSA) by detection of mecA gene was estimated as 47.5 % (95/200), of which the rate of MRSA in coagulase positive and negative isolates was 35% (50/143), and 65% (45/57), respectively. Meanwhile, coa gene was detected in 100% of coagulase positive and 28.1% of coagulasenegative isolates. CONCLUSION: The results of this study showed that the number of atypical CNSA in our area is high. Since the coagulase test is an essential test for diagnosis of S. aureus, our findings regarding the emergence of CNSA are a warning about the misdiagnosis and selection of appropriate treatment approach for S. aureus isolates.