Comprehensive Stereoselectivity Assessment of Toxicokinetics, Tissue Distribution, Cytotoxicity, and Environmental Fate of Chiral Pesticide Propiconazole.

Propiconazole (PRO) has been widely used in the treatment of fungal infection in fruits, vegetables, cereals, and seeds. In this study, a newly established chiral liquid chromatography tandem mass spectrometry method was applied to the systemic stereoselectivity evaluation of PRO enantiomers, including toxicokinetics, tissue distributions, cytotoxicity, accumulation, and degradation. Our results showed that both trans (+)-2S,4S-PRO and cis (-)-2S,4R-PRO had lower Cmax and AUC0-∞ and higher CLz/F values in plasma and lower accumulation concentrations in the liver, heart, and brain. In cytotoxic assays, cis (-)-2S,4R-PRO exhibited the lowest cytotoxicity in PC12 neuronal, N9 microglia, SH-SY5Y neuroblastoma, and MRC5 lung fibroblast cell lines. Moreover, the Eisenia fetida incubation experiment revealed that the accumulations of both trans (+)-2S,4S-PRO and cis (-)-2S,4R-PRO were higher than those of their antipodes in E. fetida. In summary, our findings first suggested that the application of cis (-)-2S,4R-PRO for agriculture would hugely reduce the environmental risk.

[Distribution and Pollution Assessment of Nutrients in the Surface Sediments of a Macrophyte-Dominated Zone in Lake Taihu].

To clarify the spatial distribution and pollution status of nutrients in the surface sediments from a macrophyte-dominated zone in Lake Taihu, total nitrogen (TN), total phosphorus (TP), alkali nitrogen (AN), available phosphorus (AP), and organic matter (OM) were measured at 60 sampling sites in Xukou Bay. A pollution evaluation and source apportionment analysis of these nutrients was also carried out. The average contents of TN, TP, AN, AP, and OM in the surface sediments of Xukou Bay were 1027.5, 423.2, 46.4, 15.3, and 17096.6 mg·kg-1, respectively, with the OM content being significantly higher in the northeast zone than in other areas of the bay. The average value of STN and STP was 1.75 and 0.91, respectively, indicating that TN and TP represent moderate and mild levels of pollution, respectively. The average comprehensive pollution index (FF) was 1.57, indicated that the surface sediment was moderately polluted. The observed organic pollution index indicated that the surface sediments in Xukou Bay were generally clean. Based on C/N values, organic matter in the surface sediments is derived from the bio-deposition of non-fibrous plants and phytoplankton. Based on correlation analysis, OM and TN in the surface sediments of Xukou Bay are derived from the same source, while TP is derived from an alternative source.

Assessment of the incidence of squamous cell papilloma of the esophagus and the presence of high-risk human papilloma virus.

BACKGROUND AND AIMS: There has been a recent increase in the incidence of oropharyngeal cancer (OPC) associated with high-risk human papilloma virus (HPV) infection. We investigated the incidence of esophageal papilloma and the presence of high-risk HPV infection. METHODS: This is a cross-sectional study conducted at a County teaching hospital. Patients with esophageal papilloma between January 2000 and December 2013 were identified. Patients with sufficient specimens were tested for the HPV virus. RESULTS: Sixty patients with esophageal papilloma lesions were identified from 2000 to 2013. (31 males, age 51 ± 13 years). The incidence was 0.13% in 2000 and increased to 0.57% in 2013 (P < 0.0001). Twenty-nine patients (48.3%) had a papilloma that was more than 5 mm in size, and 20% had multiple lesions. The papilloma was located in the distal esophagus in 35 (58.3%) patients, mid esophagus in 17 (28.3%) patients, and proximal in 8 (13.3%) patients. Three (5%) patients had associated OPC, and 9 (47.4%) of the 19 patients tested were positive for high-risk HPV serotype 16. CONCLUSIONS: The incidence of esophageal papilloma has increased by fourfolds over the past 14 years. About half of the tested patients demonstrated high risk HPV. This may suggest a potential growing risk for esophageal squamous cell cancer in the future.