Molecular Identification of Bupleurum chinense Seeds Based on DNA Barcoding Technology / 中国实验方剂学杂志

Objective:To establish a molecular identification method for Bupleurum chinense seeds based on ribosomal DNA internal transcribed spacer (ITS) sequence, ensuring the species authenticity of the cultivated seeds of B. chinense. Method:A total of 59 seeds samples of B. chinense and its main cultivated species, marketed B. chinense were collected. The effect of different sampling amounts and different water bath conditions on DNA extraction quality of the seeds was investigated, a DNA extraction method for seeds of Bupleurum was established. Their ITS sequences were obtained by polymerase chain reaction (PCR) and bidirectional sequencing. In addition, 34 ITS sequences of main cultivated Bupleurum species, such as B. chinense, B. scorzonerifolium, B. falcatum and B. smithii, were downloaded from GenBank to enrich identification database of B. chinense seeds. The neighbor-joining (NJ) dendrogram were constructed by MEGA-X 10.0.5 software to investigate the the species identification ability of ITS sequences for B. chinense seeds. And DNA barcoding identification of marketed B. chinense seeds was conducted based on BLAST method and NJ dendrogram method. Result:In total, 59 ITS sequences were obtained. ITS sequences of B. chinense could be divided into six haplotypes, including seven variable sites. The NJ dendrogram indicated that all the haplotypes of B. chinense could form independent branches, which could be distinguished from other cultivated species of Bupleurum in the collected samples, and possessed the ability to identify species of B. chinense seeds. Based on ITS sequence barcoding identification, 3 of the 19 marketed B. chinense seeds were B. falcatum with a counterfeit rate of 15.8%. Conclusion:DNA barcoding technology based on ITS sequence can accurately and reliably identify B. chinense seeds and its adulterants, providing reference for the standardization construction of Chinese medicinal materials seeds.

Studies on biological characteristics and germination conditions of Thladiantha dubia seeds / 中国中药杂志

<p><b>OBJECTIVE</b>To study the biological characteristics and find out the optimum condition for germination of seed of Thladiantha dubia Bunge for its standardized culturing.</p><p><b>METHOD</b>The weight per 1 000 seeds, seed moisture content and seed viability were determined. The biological characteristics were studied and germination conditions of seed of T. dubia were tested under following conditions: different seed soaking time, different temperatures (15, 20, 25, 30, 35 degrees C) and different irradiation time (0, 5, 10, 15, 20 min).</p><p><b>RESULT</b>The average length, width and thickness of T. Dubia seed were 4.96, 3.25 and 1.08 mm, respectively. The weight per 1 000 seeds was 14.03 g; the seed moisture content was 10.10%; the seed viability was 90.33%. Under the same condition of light, temperature and other factors, the seed germination percentage and germination energy were the highest after seed soaking 24 h. The suitable temperature range of seeds was form 25 degrees C to 35 degrees C. Under different irradiation time, the seed germination percentage and germination energy were the highest after irradiation 10 min. In different germinating beds, the seeds germination percentage and germination energy were the highest on paper (TP), which was 89.33%.</p><p><b>CONCLUSION</b>The optimum condition for the germination of the seed of T. dubia is seed soaking 12 h, irradiation 10 min, 25-30 degrees C on filter paper.</p>

Analysis of EGFR mutations in 176 cases of non-small cell lung cancer / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To analyze the incidence and profile of mutations in epidermal growth factor receptor (EGFR) in Chinese patients with non-small cell lung cancer (NSCLC).</p><p><b>METHODS</b>A total of 176 cases of NSCLC tissue was enrolled in this study, among which 123 normal lung samples were also included. The tissue DNA was extracted and the EGFR gene in exon 19 to 21 was subjected for PCR amplification and direct sequencing.</p><p><b>RESULTS</b>The EGFR gene in exon 19-21 was of wild type in all normal lung tissues detected. Mutations were found in 57 cases of 176 lung cancer samples, with an incidence of 32. 4%. Mutations were mainly detected in the exon 19 (37/57 cases, 64. 9% ) and exon 21 (18/57 cases, 31. 6% ) , while that in the exon 20 was rare (2/57 cases, 3. 5% ). There were 7 types of EGFR mutation in the exon 19, resulting in the deletion of codon 746 to 753. A missense mutation was detected in exon 20, dealing with codon 789 to 793. The mutation in exon 21 belonged to the single missense substitution in codon 858. The EGFR mutations were more frequent in female patients than male ones, in adenocarcinoma and adenosquamous cell carcinoma versus cancer of other histologies.</p><p><b>CONCLUSION</b>EGFR mutation is a tumor-specific somatic abnormality. Some one third of Chinese NSCLC tumors harbor EGFR mutations, especially in exons 19 and 21. These mutations are more frequently detected in female, adenocarcinoma and adenosquamous cell carcinoma.</p>