ABSTRACT The carapace of the tortoise Chinemys reevesii is an ingredient of “Guijia”, a traditional Chinese medicine. However, C. reevesii is difficult to raise in aquaculture and is rare in the wild. Counterfeit tablets are made from carapaces of other species. In addition to C. reevesii, other species including Mauremys sinensis, Indotestudo elongate and Trachemys scripta have been used in Plastrum Testudinis as well. After processing, these carapaces are difficult to identify on the basis of morphological characteristics, which impedes law enforcement. Our study used DNA barcoding technology to identify C. reevesii and its substitutes. We extracted concentrated genomic DNA for PCR amplification. Based on the analysis of 61 full-length COI sequences, we designed four pairs of mini-barcode primers: Tu-A, Tu-B, Tu-C and Tu-D. The Tu-B primers sequenced genomic DNA with a success rate of 76.47%, and the Tu-D primers sequenced genomic DNA with a success rate of 88.24%. The identification efficiency of these two mini-barcodes was 70.59% and 64.71%, and the overall identification efficiency was approximately 76.47%. Similarly, a set of mini barcode systems was generated, which may provide an effective and low-cost method for the identification of authentic tortoise shells.

A facile sensing platform for the detection of L-dopa has been developed by electropolymerizing glutathione disulfide (PGSSG) on the surface of glass carbon electrodes (GCE) which were modified by multi-walled carbon nanotubes (MWCNTs). The electrochemical behaviour of the proposed electrodes were investigated via cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The morphology of the PGSSG and PGSSG/MWCNTs were characterized by scanning electron microscopy (SEM). Under the optimized experimental conditions, the sensing platform showed the linear response to L-Dopa in a range from 1.0 X 10-6 to 1.2X10-3 M with a detection limit of 3.3 X 10-7 M (S/N = 3). Moreover, with the merits of high sensitivity and selectivity, good stability and reproducibility, the sensor was successfully applied for the determination of L-dopa in a real sample.

Hypoxia-ischemia (HI) occurring in immature brains stimulates the expression of tissue-type plasminogen activator (tPA). Neuroserpin is a selected inhibitor of tPA in the central nerves system. However, the role that neuroserpin plays and the possible mechanisms involved during neonatal HI are poorly defined. In this study, an oxygen-glucose deprivation and reoxygenation (OGD/R) model was generated with cultured rat cortical neurons mimicking neonatal HI injury ex vivo, and an acute neuronal excitatory injury was induced by exposure to a high concentration of N-methyl-D-aspartic acid (NMDA). Cells received either neuroserpin or MK-801, an antagonist of the NMDA receptor, during OGD/R, and were incubated with or without neuroserpin after NMDA exposure. Cell viability and morphology were detected by a Cell Counting Kit-8 and immunohistochemical staining, respectively. TPA expression and activity were also assessed. We found that MK-801 alleviated injuries induced by OGD/R, suggesting an excitatory damage involvement. Neuroserpin provided a dose-dependent neuroprotective effect in both OGD/R and acute excitatory injuries by inhibiting the activity of tPA, without affecting neuronal tPA expression. Neuroserpin protected neurons against OGD/R even after a delayed administration of 3h. Collectively, our data indicate that neuroserpin protects neurons against OGD/R. mainly by inhibiting tPA-mediated acute neuronal excitotoxicity.