Surveillance of drug abuse in Hong Kong by hair analysis using LC-MS/MS.

The aim of this study is to reveal the habits of drug abusers in hair samples from drug rehabilitation units in Hong Kong. With the application of liquid chromatography-tandem mass spectrometry (LC-MS/MS) technology, a total of 1771 hair samples were analyzed during the period of hair testing service (January 2012 to March 2016) provided to 14 drug rehabilitation units including non-governmental organizations (NGOs), rehabilitation centers, and medical clinics. Hair samples were analyzed for abused drugs and their metabolites simultaneously, including ketamine, norketamine, cocaine, benzoylecgonine, cocaethylene, norcocaine, codeine, MDMA, MDA, MDEA, amphetamine, methamphetamine, morphine, 6-acetylmorphine, phencyclidine, and methadone.

Determination of hair ketamine cut-off value from Hong Kong ketamine users by LC-MS/MS analysis.

Ketamine is one of the most frequent abused drugs in Hong Kong and South-East Asia, and the cases of ketamine abused have been reported worldwide. Hair has been commonly used as a specimen for the proof of chronic drug abused because of its non-invasiveness and long detection windows. The determinations of ketamine in hair with varieties of state-of-the-art instruments and detection methods have been developed in the past decade; however, the cut-off value for ketamine abuser has not been developed according to the international guidelines.

Two-dimensional ultrasound measurement of thyroid gland volume: a new equation with higher correlation with 3-D ultrasound measurement.

This study aimed to develop a new two-dimensional (2-D) ultrasound thyroid volume estimation equation using three-dimensional (3-D) ultrasound as the standard of reference, and to compare the thyroid volume estimation accuracy of the new equation with three previously reported equations. 2-D and 3-D ultrasound examinations of the thyroid gland were performed in 150 subjects with normal serum thyrotropin (TSH, thyroid-stimulating hormone) and free thyroxine (fT4) levels (63 men and 87 women, age range: 17 to 71 y). In each subject, the volume of both thyroid lobes was measured by 3-D ultrasound.