Detection and analysis of gene polymorphism in hepatitis B virus C region / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To explore the variations of gene C in hepatitis B viruses between hepatitis B patients and healthy carriers, and provide experimental evidences for analysis of virus gene mutations acting on the virus material science and response of the body to the virus.</p><p><b>METHODS</b>The virus DNA load in hepatitis B patients and healthy blood donors was investigated by real-time polymerase chain reaction (PCR). Gene sequence analysis was taken to detect gene polymorphism, and all the success samples were compaired with standard strain by DNAstar.</p><p><b>RESULTS</b>(1)G Compared with standard strain, C region in all samples had mutations, there were 31 mutations in at least 2 samples (3 mutations in gene PreC and 28 mutations in gene C), including 9 missense mutations, 1 chain termination mutation and 21 synonymous mutation. Mutations nt 1827 c-->a and nt 2221 c-->t existed in all the samples, and most samples had 6 synonymous mutations. Four hepatitis B patients had mutation nt1896 g-->a, and another 4 patients had 2 mutations, namely, S87G and I97F (or 197L) in HBcAg CTL recognition episome. (2) The success ratio of amplification and sequencing of HBV DNA was closely associated with its copy numbers. In the present study, copy numbers of HBV DNA which were successfully amplified and sequenced were almost more than 40 193/ml.</p><p><b>CONCLUSIONS</b>HBV genome were easily affected by nucleotide mutations, 2 residues had mutations in gene of C region, which is firstly reported, suggesting these mutations may be geographical restricted. Mutations in gene of C region may either change the structure and function of HBeAg and HBcAg, which may further induce the escape of immune clearance for HBV or influence the detection of HBsAg or HBeAg, which may creat new problems for the prevention, diagnosis and treatment of hepatitis B.</p>

Clinical detection and movement recognition of neuro signals / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Neuro signal has many more advantages than myoelectricity in providing information for prosthesis control, and can be an ideal source for developing new prosthesis. In this work, by implanting intrafascicular electrode clinically in the amputee's upper extremity, collective signals from fascicules of three main nerves (radial nerve, ulnar nerve and medium nerve) were successfully detected with sufficient fidelity and without infection. Initial analysis of features under different actions was performed and movement recognition of detected samples was attempted. Singular value decomposition features (SVD) extracted from wavelet coefficients were used as inputs for neural network classifier to predict amputee's movement intentions. The whole training rate was up to 80.94% and the test rate was 56.87% without over-training. This result gives inspiring prospect that collective signals from fascicules of the three main nerves are feasible sources for controlling prosthesis. Ways for improving accuracy in developing prosthesis controlled by neuro signals are discussed in the end.