Bufadienolides and polyhydroxycholestane derivatives from Bufo bufo gargarizans.

A new polyhydroxycholestane sulfate ester, 3α,12β,25,26-tetrahydroxy-7-oxo-5β-cholestane 26-O-sulfate (1), was isolated from dried skin of Bufo bufo gargarizans Cantor and its structure was elucidated on the basis of extensive 1D and 2D NMR as well as HR-ESI-MS analysis. A comparison of steroidal metabolite profiles, based on HPLC and LC-MS analyses, indicates that the chemical compositions of the various parts of toads, such as venom, skin and stratum corneum, are significantly different.

[Optimization of sperm alkaline single-cell gel electrophoresis].

Objective: To investigate the main factors that influence the results of sperm alkaline single-cell gel electrophoresis (SCGE), optimize the conditions, and standardize its procedures.

Methods: Using alkaline SCGE, we detected the DNA fragments of sperm treated with different concentrations of H2O2 and determined the influences of the number of agarose gel layers, pH during DNA unwinding and electrophoresis, the time of DNA unwinding and electrophoresis, and cumulative sperm number on the results of sperm alkaline SCGE. Then we optimized the procedures, analyzed the repeatability of the optimized method, and examined 40 semen samples using the method.

[Screening for congenital hypothyroidism in 106 224 neonates in Hunan Province].

Objective: Diagnosing congenital hypothyroidism (CH) early was studied in this paper through neonatal screening to prevent children's mental retardation.

Methods: The first step is mensurating the concentration of thyroid stimulating hormone (TSH) with the method of time-distinguished fluorometry immunoassay. If the result is positive, then it is necessary to mensurate the serum TSH, free triiodothyronine (FT3),free thyroxin (FT4) with chemiluminescence immunoassay (CLIA) and execute clinical diagnosis.