Low-toxic, fluorescent labeled and size-controlled graphene oxide quantum dots@polystyrene nanospheres as reference material for quantitative determination and in vivo tracing.

Polystyrene (PS) is selected as a representative nanoplastic and persistent pollutant for its difficult degradation and wide application. The environmental risk assessment of PS is obstructed by the toxic dye-based fluorescent PS, which false positives could be induced by the leakage of dye. For high biocompatibility, low toxicity, hydrophilicity, good water dispersibility, strong fluorescent stability, graphene oxide quantum dots (o-CQDs) are selected and embedded into PS microspheres, i.e., o-CQDs@PS, by microemulsion polymerization and denoted as CPS. Meanwhile, the sizes of CPS, e.g., 100, 150, and 200 nm, could be controlled by optimizing the type and number of water-soluble initiators. The anti-interference, low toxicity, and in vivo fluorescent tracing of CPS are proven by the coexistence of metals (including Fe2+, Fe3+, K+, Ba2+, Al3+, Zn2+, Mg2+, Ca2+, and Na+) on the fluorescence intensity of CPS, the growth of Chlorella pyrenoidosa and Artemia cysts as aquatic phytoplankton and zooplankton cultured with CPS, and the transfer of CPS from water into brine shrimp. In the concentration range of 0.1-100 mg/L, CPS can be quantitatively determined, which is suitable for coastal water and wastewater treatment plants. Therefore, CPS with standard size is suitable as reference material of PS.

[Relation between insulin resistance and insulin receptor gene methylation in the endometrium of patients with polycystic ovary syndrome].

OBJECTIVE: To study the relationship between insulin resistance and methylation of insulin receptor (INSR) gene in the endometrium of women with polycystic ovary syndrome (PCOS). METHODS: Based on the HOMA index, 35 patients with PCOS were divided into insulin resistant group (IR group, n=18) and non-resistant group (NIR group, n=18). The patients age, serum estriol, testosterone, FSH and LH, fasting insulin and fasting blood glucose were compared between the two groups. The endometrial samples were obtained from the patients to examine DNA methylation status of INSR gene in the endometrial cells using methylation-specific PCR. RESULTS: The BMI, WHR, fasting glucose, fasting insulin, and HOMA index differed significantly between the two groups (P<0.05). PCR analysis showed partial methylation in the promoter region of INSR gene in 13 samples in IR group and 11 samples in NIR group, without detection of full methylation of the INSR gene in either group. The methylation status showed no significant difference between the two groups (P=0.328). CONCLUSION: Partial methylation of the INSR gene occurs in the endometria of PCOS patients, but this study does not provide a strong evidence supporting the relationship between insulin resistance and INSR gene methylation in women with PCOS.

[Correlations between preS1-antigen, HBV-DNA and HBV serum markers in patients with chronic hepatitis B].

OBJECTIVE: To study the correlations between preS1 antigen, HBV-DNA and hepatitis B virus (HBV) serum markers in patients with chronic hepatitis B. METHODS: The HBV markers, preS1 antigen and HBV-DNA were determined using enzyme- linked immunosorbent assay and quantitative PCR in 1158 patients with chronic hepatitis B. RESULTS: In these patients, the HBV-DNA positivity rate was 68.9%, significantly higher than preS1 antigen positivity (54.8%, chi2=53.24, P<0.005). The positivity rates of both HBV-DNA and PreS1-antigen were significantly higher in HBeAg-positive patients than in HBeAg-negative patients (P<0.005). The coincident rates of preS1-antigen and HBeAg with HBV-DNA were 56.9% and 63.3%, respectively. PreS1 antigen had higher sensitivity but lower specificity than HBeAg. The detection rates of preS1 antigen and HBeAg increased with the level of HBV-DNA, and preS1 antigen positivity was higher than that of HBeAg in patients with low HBV-DNA levels. CONCLUSION: Detection of HBV serum markers along with preS1 antigen and HBV-DNA may help assess the status of viral replication and therapeutic efficacy in patients with chronic hepatitis B. PreS1 antigen may serve as an auxiliary indicator in HBeAg-negative cases or when HBV-DNA detection is impossible.