Objective:The methylation status is considered as powerful diagnostic, prognostic, and predictive biomarkers. However, the limited DNA amount and conversion efficiency after bisulfite treatment are considerable hindrances in quantitative methylation analysis. In this study, we designed an artificial internal control (IC) system that contained the cytosine-free fragment (CFF) following CpG sequences of the SHOX2 promoter whose methylation status has been described as a valuable biomarker of lung cancer. Its performance in quantifying DNA recovery and bisulfite conversion efficiency as well as in detecting false-positive SHOX2 methylation was determined on samples from lung cancer patients. Material and Methods:The IC system is composed of two pConIC and pUnIC plasmids that both contain a cytosine-free (CF) sequence derived from the CFF and the CpG containing SHOX2 sequences. They are identical in sequence, except that in the ConIC insert, all cytosines have been converted into thymines. Thus, the ConIC can be used as calibrator of 100% bisulfite conversion efficiency, while the UnIC is the indicator in order to evaluate the DNA recovery, bisulfite conversion efficiency of the SHOX2 promoter sequence by quantitative real time PCR. Results:The copy number of the target sequences impacted on both DNA recovery rates and bisulfite conversion efficiency. An amount of 0.005 ng pUnIC (106 copies) showed recovery rate of 18%, similar to that of pConIC, and a bisulfite conversion efficiency of the SHOX2 reaching 98.7%. On the contrary, higher copy number of pUnIC showed incomplete conversion (<85%) and over recovery (~42%). Using this calibrator/indicator couple, we were able to detect false-positive SHOX2 methylation (3.77% instead of 0.03%) due to incomplete bisulfite conversion.Conclusion:Our results proposed a customizable internal control using the ConIC/UnIC as calibrator/indicator to quantify simultaneously and accurately the DNA recovery and bisulfite conversion efficiencies of individual sequence as well as whole genome in methylation assays, thus promoting the validation of standardized clinical DNA methylation biomarker values to progress toward clinical applications.

Epigenetic alterations play a main role in the initiation and progression of lung cancer.  CpG methylation in the promoter of the Short Stature Homeobox 2 (SHOX2) gene has been evaluated and validated at different stages of this malignant disease. Several approaches for measuring DNA methylation have been established, including quantitative methylation-specific PCR (qMSP). This is a simple, fast, and cost-effective technique that can be easily applied to clinical practice. In this study, formalin-fixed, paraffin-embedded (FFPE) tissue samples were collected from 30 lung cancer patients and 30 patients suffering from non-cancerous pulmonary diseases.  The methylation level of SHOX2 was evaluated in two CpG-riched regions by using qMSP and one of them could be conferred as a potential biomarker to lung cancer.

This study was conducted to investigate the species composition of Chlorophyta and Charophyta in Bach Ma National Park, Thua Thien Hue province. Here, we identified 45 species and subspecies, belonging to 17 genera, 7 families, and 4 orders. Charophyta was the most diverse phylum, with 75.56% total species. The dominant orders and families are Desmidiales and Desmidiaceae. The most diverse genus belongs to Cosmarium (15), Euastrum (5) and Scenedesmus (5). Micrasterias foliacea Bailey ex Ralfs and Cosmarium pardalis Cohn are tropical algae, while transitional species and temperate species are also present such as Cosmarium pachydermum Lund. var. indicum Iyenf. et Vim Bai and Euastrum jenneri W. Archer, respectively. The dominant group is described as Desmidiales with Chlorococcales (Ch. I) index ranging from 0.087 to 0.19 in Thuy dien Dam and Thuy dien bridge, while there are several species of Sphaeropleales with Ch. I index of 0.67 in Hoang Yen stream.  

Nghiên cứu này được thực hiện nhằm đánh giá mức độ ảnh hưởng của các yếu tố đến chất lượng huấn luyện khối khách hàng doanh nghiệp tại Ngân hàng Kỹ thương Việt Nam (Techcombank- TCB) Chi nhánh Thành phố Hồ Chí Minh (TPHCM), bằng việc khảo sát 259 nhân viên đã tham gia các khóa huấn luyện, công cụ Cronbach’s alpha, EFA và phân tích hồi quy bội được sử dụng, với phần mềm SPSS 20.0. Kết quả đã đưa ra được mô hình chất lượng huấn luyện khối khách hàng doanh nghiệp tại TCB TPHCM gồm 6 nhân tố, sắp xếp theo thứ tự độ mạnh giảm dần: (1) Cơ sở vật chất, (2) Chương trình huấn luyện, (3) Khối lượng công việc, (4) Chất lượng huấn luyện viên, (5) Sự hỗ trợ về công nghệ và (6) Sự hỗ trợ về chính sách. Từ đó, nghiên cứu đề xuất các hàm ý quản trị đến Ban Lãnh đạo Techcombank TPHCM nhằm nâng cao chất lương huấn luyện nhân viên.