This study was designed to investigate the surface properties especially surface porosity of polyhydroxybutyrate (PHB) using scanning electron microscopy. PHB granules were sprinkled on the double-sided sticky tape attached on a SEM aluminium stub and sputtered with gold(10nm thickness) in a Polaron SC515 Coater, following which the samples were placed into the SEM specimen chamber for viewing and recording. Scanning electron micrographs with different magnification of PHB surface revealed multiple pores with different sizes.
Biocompatible Materials/*analysis ; Hydroxybutyrates/*analysis ; *Materials Testing ; *Microscopy, Electron, Scanning ; Porosity ; Surface Properties

OBJECTIVE: A rapid color test for screening gamma-hydroxybutyric acid (GHB) and its precursor gamma-butyrolactone(GBL) was investigated in drink and urine samples. METHODS: In an acidic solution, GHB was converted to GBL, which reacted with hydroxylamine hydrochloride in presence of sodium hydroxide, forming hydroxamate. A purple complex was formed when hydroxamate reacted with ferric chloride in acidic condition. RESULTS: Detection limit concentrations of GHB in drinks were between 0.5-2 mg/mL, less than the popular abuse concentrations of GHB. This method was usable for urine, with detection limit concentration 0.5 mg/mL. Interferences of common organic solvents and narcotics and depressants were surveyed. CONCLUSION This method is simple, safe, and rapid; it facilitates rapid screening of GHB and GBL in clinic and forensic laboratories.
4-Butyrolactone/urine* ; Alcoholic Beverages/analysis* ; Anesthetics/urine* ; Beverages/analysis* ; Forensic Medicine/methods* ; Humans ; Hydrogen-Ion Concentration ; Hydroxybutyrates/urine* ; Solvents/chemistry* ; Sulfuric Acids/chemistry*

OBJECTIVES: To find a method to distinguish exogenous gamma-hydroxybutyrate (GHB) from endogenous GHB by establishing ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS) based on exosome for quantitative detection of GHB in the rat blood. METHODS: Adult male SD rats were divided into 1 h, 5 h, 10 h administration group and control group. After 1 h, 5 h and 10 h of single precursor of GHB gamma-butyrolactone (GBL) intraperitoneal injection in administration groups, 5 mL blood was collected from the abdominal aorta. Meanwhile, the control group was given a same dose of normal saline, and 5 mL blood was collected at 1 h. Among the 5 mL blood, 0.5 mL was directly detected by HPLC-MS after pretreatment, and exosomes were extracted from the remaining blood by differential centrifugation and detected. RESULTS: The concentration of GHB in the control group was (87.36±33.48) ng/mL, and the concentration with administration at 1 h, 5 h and 10 h was (110 400.00±1 766.35) ng/mL, (1 479.00±687.01) ng/mL and (133.60±12.17) ng/mL, respectively. The results of exosome detection showed that no peak GHB signal was detected in the control group and the 10 h administration group, and the concentrations of GHB at 1 h and 5 h administration groups were (91.47±33.44) ng/mL and (49.43±7.05) ng/mL, respectively. CONCLUSIONS GHB was detected in blood exosome by UPLC-MS, which indicated that exogenous GHB could be detected in plasma exosomes, while endogenous GHB could not be detected, suggesting that this method may be used as a basis to determine whether there is exogenous drug intake.
4-Butyrolactone/chemistry* ; Animals ; Chromatography, Liquid ; Exosomes/chemistry* ; Hydroxybutyrates/chemistry* ; Male ; Rats ; Rats, Sprague-Dawley ; Sodium Oxybate/analysis* ; Tandem Mass Spectrometry/methods*

OBJECTIVETo observe metabolomic changes in urine of chronic superficial gastritis (CSG) patients with Pi-qi deficiency syndrome (PQDS) or Pi-Wei dampness-heat syndrome (PWDHS), thereby providing scientific evidence for syndrome typing of them.

METHODSUrine samples were collected from CSG patients with PQDS/PWDHS and healthy volunteers, 10 in each group. Proton nuclear magnetic resonance spectroscopy (1H-NMR) based metabonomic analysis was performed on urine samples. Contents of related biomarkers were analyzed by principal component analysis (PCA), partial least square discriminant analysis (PLS-DA), and urivariate statistical analysis.

RESULTSPLS-DA analysis showed that metabolites among CSG patients with PQDS/PWDHS and healthy volunteers could be mutually distinguished. Seven differentially identified metabolites were screened from urines of CSG patients with PQDS and healthy volunteers included glutamate, methionine, α-oxoglutarate, dimethylglycine, creatinine, taurine, and glucose. Four differentially identified metabolites were screened from urines of CSG patients with PWDHS and healthy volunteers included 2-hydroxybutyric acid, trimethylamine oxide, taurine, and hippuric acid. Eleven differentially identified metabolites were screened from urines of CSG patients with PQDS and PWDHS included fucose, β-hydroxybutyric acid, alanine, glutamate, methionine, succinic acid, citric acid, creatinine, glucose, hippuric acid, and lactic acid.

CONCLUSIONThe metabolic differences of CSG patients PQDS and PWDHS mainly manifested in glycometabolism, lipid metabolism, and amino acids catabolism, and 1H-NMR based metabonomics may be used in classified study of Chinese medical syndrome typing.

Biomarkers ; urine ; Discriminant Analysis ; Gastritis ; urine ; Hot Temperature ; Humans ; Hydroxybutyrates ; Ketoglutaric Acids ; Least-Squares Analysis ; Medicine, Chinese Traditional ; Metabolome ; physiology ; Metabolomics ; Principal Component Analysis ; Proton Magnetic Resonance Spectroscopy ; Qi ; Syndrome

OBJECTIVE: The possibility for the identification of GHB administration through hair analysis was investigated to provide method and information for toxicology examination of GHB. METHODS A GC/MS assay for GHB in hair was developed. Endogenous levels of GHB in hair, time course of GHB in hair, relationship between GHB levels in hair and hair color or administration dose were also established by guinea pig model. RESULTS: Endogenous levels of GHB in guinea pig black hair and human black hair were (3.01 +/- 1.41) ng/mg (n=28) and (1.02 +/- 0.27) ng/mg (n=20), respectively. GHB levels in black hair were increased by GHB administration and related with drug dosage, and also much higher than in brown and white hair. CONCLUSION Analysis of GHB in hair is suitable for investigation of GHB abuse in forensic toxicology and GHB level in segmental analysis compared with endogenous level of GHB may provide useful information about GHB administration.
Animals ; Dose-Response Relationship, Drug ; Forensic Toxicology/methods* ; Gas Chromatography-Mass Spectrometry/methods* ; Guinea Pigs ; Hair/chemistry* ; Hair Color ; Humans ; Hydroxybutyrates/analysis* ; Male ; Substance Abuse Detection/methods* ; Time Factors