Potential mediation effect of insulin resistance on the association between iron metabolism indicators and non-alcoholic fatty liver disease.

OBJECTIVES: Iron metabolism and insulin resistance (IR) are closely related to non-alcoholic fatty liver disease (NAFLD). However, the interplay between them on the occurrence and progression of NAFLD is not fully understood. We aimed to disentangle the crosstalk between iron metabolism and IR and explore its impact on NAFLD. METHODS: We analyzed data from the National Health and Nutritional Examination Survey (NHANES) 2017-2018 to evaluate the association between serum iron metabolism indicators (ferritin, serum iron, unsaturated iron-binding capacity [UIBC], total iron-binding capacity [TIBC], transferrin saturation, and transferrin receptor) and NAFLD/non-alcoholic steatohepatitis (NASH). Mediation analysis was conducted to explore the role of IR played in these relationship. RESULTS: A total of 4812 participants were included, among whom 43.7% were diagnosed with NAFLD and 13.2% were further diagnosed with NASH. After adjusting the covariates, the risk of NAFLD increases with increasing serum ferritin (adjusted odds ratio [aOR] 1.71, 95% confidence interval [CI] 1.37-2.14), UIBC (aOR 1.45, 95% CI 1.17-1.79), and TIBC (aOR 1.36, 95% CI 1.11-1.68). Higher levels of serum ferritin (aOR 3.70, 95% CI 2.25-6.19) and TIBC (aOR 1.69, 95% CI 1.13-2.56) were also positively associated with NASH. Participants with IR were more likely to have NAFLD/NASH. Moreover, IR-mediated efficacy accounted for 85.85% and 64.51% between ferritin and NAFLD and NASH, respectively. CONCLUSION: Higher levels of serum ferritin and TIBC are closely associated with the occurrence of NAFLD and NASH. IR may be considered a possible link between NAFLD or NASH and increased serum ferritin levels.

[Characterization and Health Risk of Heavy Metals in PM2.5 from Road Fugitive Dust in Five Cities of Yunnan Province].

In order to study the contents, sources, and health risk of PM2.5 in road fugitive dust in Yunnan, road fugitive dust samples were collected from five typical cities including Kunming, Baoshan, Wenshan, Zhaotong, and Yuxi. Particulate matter resuspension technology was used to levitate the dust samples and collect PM2.5. Eight heavy metals including chromium (Cr), manganese (Mn), nickel (Ni), copper (Cu), zinc (Zn), selenium (As), cadmium (Cd), and lead (Pb) in PM2.5 were detected using ICP-MS. The results showed that the contents of Cr, Ni, Cu, Zn, and Pb in road fugitive dust seriously exceeded the background values of Yunnan soil. The enrichment factors showed that most of the heavy metals in PM2.5 of road fugitive dust in the five cities of Yunnan were moderately enriched and strongly enriched, which were greatly influenced by human activities. The results of correlation analysis and principal component analysis showed that the heavy metals in PM2.5 of road fugitive dust in Yunnan were all affected by soil and traffic sources. The other sources varied greatly in different cities:Kunming was affected by iron and steel melting sources, Baoshan and Yuxi were affected by non-ferrous metal smelting sources, and Zhaotong was affected by coal sources. Health risk analysis showed that Cr, Pb, and As in road fugitive dust PM2.5 had non-carcinogenic risk in children in Kunming, Yuxi, and Zhaotong, respectively, and Cr in Kunming also had a lifetime carcinogenic risk.

Identification of linear epitopes and their major role in the immunoglobulin E-binding capacity of tropomyosin from Alectryonella plicatula.

Tropomyosin (TM) is an important allergen in molluscans. However, there was a lack of information about TM as an allergen in oysters. TM was purified and identified from Alectryonella plicatula (ATM), and its primary sequence was cloned and encoded with 284 amino acids (AAs). Chemical denaturants were used to destroy the structure to confirm that linear epitopes played a major role in the immunoglobulin E-binding capacity of ATM. Subsequently, nine linear epitopes were identified using a serological test. The peptide with AA27-41 was regarded as the key epitope because it could be recognized strongly by most sera of oyster-sensitive individuals in comparison to other epitope peptides. Finally, the epitopes and the primary sequence of TM among shellfish were aligned to find the two conserved epitopes (AA117-132 and AA164-178) in oyster, octopus, abalone, scallop, clam, shrimp, and crab. Overall, these data provide a foundation for the allergenicity and cross-reactivity of TM.

[Pollution Characteristics and Health Risk of Heavy Metals in Fugitive Dust Around Zhaotong City].

In order to explore the pollution characteristics and health risks of heavy metals in fugitive dust around the urban areas of Zhaotong City, road dust and soil dust samples were collected in the Zhaoyang District of Zhaotong City in May 2019. The dust samples were suspended using a particle resuspension system to obtain PM2.5 (particulate matter with an aerodynamic diameter less than or equal to 2.5 µm). The concentrations of Ca, Al, Fe, Mg, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, As, Cd, and Pb in PM2.5 were quantified by ICP-MS and ICP-OES. By analyzing 10 types of heavy metals in PM2.5, the results showed that the average concentration of Mn was the highest in the soil fugitive dust, followed by Cr, Ni, Zn, Cu, Co, Pb, V, As, and Cd. The average concentration of Zn in the road fugitive dust was the highest, followed by Mn, Cu, Cr, Pb, Ni, As, Co, V, and Cd. The enrichment factor (EF) indicated that Cd was strongly enriched in the two types of fugitive dust. The EFs of Cu, Zn, and Pb in road fugitive dust showed a moderate enrichment, and they were higher than those in soil fugitive dust. Correlation and principal component analysis showed that heavy metals in the two types of fugitive dust were affected by coal burning sources. At the same time, heavy metals in soil fugitive dust were affected by agricultural activity sources, and heavy metals in road fugitive dust were affected by traffic sources. The results of the health risk assessment indicated that the carcinogenic risks of Cr, Co, Ni, As, and Cd in soil fugitive dust were higher than those in road fugitive dust. The non-carcinogenic risks of heavy metals in the two types of fugitive dust for children were higher than those for adults, and the non-carcinogenic risks of Cu, Zn, and Pb in road fugitive dust were higher than those in soil fugitive dust.

[Pollution Characteristics and Health Risk Assessment of Heavy Metals in Road Dust from Non-ferrous Smelting Parks].

In order to explore the pollution characteristics and health risks of heavy metals in dust from roads around non-ferrous smelting activities in different regions, dust samples from urban roads, non-ferrous smelting industry park roads, and tunnel roads were collected from the Mengzi area of Yunnan Province. The dust samples were suspended on Teflon filters by re-suspension equipment to obtain PM2.5 and PM10 samples. Eight heavy metals (Cr, Mn, Ni, Cu, Zn, As, Cd, and Pb) were analyzed by ICP-MS. The results showed that the average content of the total heavy metals in PM2.5 was higher than that in PM10. The average contents of Pb, Cd, As, and Zn were highest in all three types of road dust, and the difference in the total average content in different types of road dust was ranked as:tunnel roads > non-ferrous smelting industrial park roads > urban roads. The average contents of Pb and As in PM2.5 from the tunnel road dust were higher than other heavy metals, and reached up to 92338.3 mg·kg-1 and 12457.7 mg·kg-1, respectively. The average contents of Pb and Zn in PM2.5 from the industrial park road dust were the highest of all heavy metals (4381.7 mg·kg-1 and 4685.0 mg·kg-1, respectively). The average content of Zn and Pb in PM2.5 were the highest of all the heavy metals in the urban road dust (1952.6 mg·kg-1 and 1944.8 mg·kg-1, respectively). The average contents of Cu, Zn, As, Cd, and Pb in the different types of road dust were all higher than their background values in Yunnan Province. The results of the enrichment factor analysis and principal component analysis indicated that Cu, Zn, As, Cd, and Pb were obviously enriched in all three types of road dust, which were significantly affected by the non-ferrous smelting industry and traffic sources. In contrast, Cr, Mn, and Ni were not obviously enriched in the three types of road dust and were less affected by anthropogenic sources. The results of the health risk assessment testified that ingestion was the main exposure route, and that the children's non-carcinogenic risk was higher than that of adults. In PM2.5, As, Cd, and Pb in all types of road dust were associated with non-carcinogenic risks for adults and children. In PM10, As, Cd, and Pb in dust from the non-ferrous smelting industry park roads and tunnel roads had non-carcinogenic risks for humans. As in PM10 from the urban road dust was associated with a non-carcinogenic risk for children, whereas As in dust from the tunnel roads had carcinogenic risks.