Research Progress on Detection Methods of Amphetamines in Human Hair / 法医学杂志

Amphetamines are chemical synthetic drugs that are becoming increasingly popular in China. As a common sample in the inspection of poisons, hair has the advantages of easy storage, good stability, and long detection time compared with traditional human body fluid samples （blood, urine）, thus possesses an unique application value in the field of forensic toxicology analysis. By now, methods for detecting amphetamines in human hair have been widely used, and validity of the results has been recognized and adopted by the court. This paper reviews domestic and foreign research progress of the detection of amphetamines in hair samples, including the pretreatment and analytic methods.

Expressiona of c-Jun and collagens I and III in cultured human skin fibroblasts are affected by infrared ray radiation / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effect of solar infrared ray (IR) radiation on the expressions of c-Jun and collagens I and III in cultured human skin fibroblasts (HSFs) and explore the molecular mechanism by which IR radiation causes aging of the skin.</p><p><b>METHODS</b>Primarily cultured HSFs exposed to IR radiation were examined for changes of the cell viability with MTT assay. The mRNA and protein expressions of c-Jun and collagens I and III was detected with real-time quantitative PCR and immunocytochemistry.</p><p><b>RESULTS</b>MTT assay showed that IR irradiation caused inhibition of cell proliferation compared with the control cells. The mRNA and protein expression of collagen I was decreased significantly by IR irradiation with the increase of the irradiation dose (P<0.01). HSFs irradiated by IR for 12 h showed a dose-dependent reduction of the expression of collagen type III mRNA and protein (P<0.05, P<0.01), but the expression increased dose-dependently in response to IR exposure for 24 h (P<0.05 or 0.01). IR irradiation enhanced the mRNA and protein expression of c-Jun in a dose-dependence manner (P<0.05 or 0.01).</p><p><b>CONCLUSIONS</b>IR irradiation can increase the expression of c-Jun, inhibit the expression of collagen I, and cause disturbance in collagen III expression in human skin fibroblasts, which may be one of the mechanism of IR radiation to initiate and promote skin photoaging.</p>