Research on Noninvasive Diagnosis for Coronary Heart Disease Based on Neural Network / 航天医学与医学工程

Objective To extract characteristic parameters of ECG signals a new method of non-invasive diagnosis for coronary heart disease with artificial neural network. Methods ECG signals were digitized with A/D converter and filtered to eliminating the noise. Span of QRS interval, R-R interval,and voltage of S-T segment of filtered ECG were detected. These 3 characteristics were as the input parameters of the input layer. Samples were trained with an improved 3-layers back propagation(BP) artificial neural network, as trained samples. The non-trained samples were recognized with these BP neural networks. Results After 12 samples had been trained about 1500 times, the BP neural network could accurately distinguish samples of coronary heart disease from the trained samples and also recognize 20 non-trained samples, 19 to be correct except one. Conclusion It is showed that based on BP network and characteristic parameters of ECG, a new and promising method of non-invasive diagnosis for coronary heart disease has been found.

Modification of HPV type 16 E6 and E7 genes, and analysis of stability and immunogenicity of the modified proteins / 中华实验和临床病毒学杂志

<p><b>BACKGROUND</b>To select the mutants of HPV type 16 E6 and E7 genes suitable for construction of vaccine for treatment of cervical cancer.</p><p><b>METHODS</b>E6 and E7 genes were modified by site-directed mutagenesis. Several recombinant vaccina viruses were constructed by inserting the E6 or E7 mutants into the genome of vaccina virus Tiantan strain and employed to study their antigenicity.</p><p><b>RESULTS</b>Western blot assay showed that the E6 ?mutant? with substitution of Gly for Leu at amino acid site 50 and E7 mutant with substitution of Gly for Cys-24 and Glu-26 had no effect on their stability and antigenicity, but change of the Cys at position 91 of E7 dramatically reduced its stability and antigencity. Conclusion The results confirmed that the Zinc-finger structure at the E7 C-terminal? plays an important role in the integrity and stability of E7 protein.</p>

Construction and identification of the replication-deficient recombinant vaccinia virus co-expressing HPV type 16 L1 and L2 proteins / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To generate an HPV16 prophylactic vaccine candidate for cervical cancer.</p><p><b>METHODS</b>HPV16 major capsid protein L1 gene and minor capsid protein L2 gene were amplified using PCR. These genes were mutated by PCR site-directed mutagenesis for removal of sequence motifs (TTTTTNT) which would cause transcription termination when expressed from a vaccinia virus early promoter, then inserted into a vaccinia virus expression vector. A strain replication-deficient recombinant vaccinia virus containing the mutant sequences was obtained through a homologous recombination and identified.</p><p><b>RESULTS</b>The nucleotide sequence remained the correct amino acid sequence of the L1 and L2 proteins after mutated. Full-length L1 and L2 proteins were generated in cells infected with the recombinant virus. The virus strain propagated at very low titer or could not reproduce in some kinds of cell derived from different human tissues.</p><p><b>CONCLUSIONS</b>The authors have generated a strain replication-deficient recombinant vaccinia virus expressing HPV16 L1 plus L2 proteins as an HPV16 prophylactic vaccine candidate for cervical cancer.</p>

Construction of recombinant vaccinia virus co-expressing mutant E6 plus E7 proteins and detection of its immunogenicity and antitumor response / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To generate a candidate HPV16 vaccine for experimental and therapeutical use for cervical cancer.</p><p><b>METHODS</b>The mutants of HPV16 early E6 and E7 genes were inserted into a vaccinia virus expression vector. A strain of recombinant vaccinia virus was constructed through homologous recombination.</p><p><b>RESULTS</b>Showed that the mutant E6 and E7 genes were located at TK gene region of vaccinia virus Tiantan strain in a head to head orientation under the control of early/late promoters, H6 and 7.5K respectively. Studies in mice indicated that VmE6E7 could elicit specific antibodies against E6 and E7, and retarded or prevented tumor development in a proportion of C57 BL/6 mice challenged by syngeneic HPV16E6 and E7 transformed tumor cells.</p><p><b>CONCLUSIONS</b>The success in constructing VmE6E7 provides a basis for the further development of HPV16 therapeutic vaccine.</p>

Inducing Effects of Retinamide (RII) on Tumor Cells with Different Metastatic Ability / 中国肿瘤生物治疗杂志

Newly synthesized retinoic acid derivative-retinamide (RII) was employed as differentiation inducing agent. Cultured tumor cells of epithelial origin were exposed to 10-5mol/L RII for 5 passages. These cells included mouse fore stomach carcinoma (MFC, lung metastatic rate 85%), human nasopharyngeal carcinoma (CNE-2Z, 56%), and clonal variants from CNE-2Z, CNE2L2 (100%) and CNE2L4 (13%) . The results of serial observation were as follows. The growth, clone-forming ability, motility, invasiveness of these tumor cells were obviously inhibted. Their adhesion to fibronectin and laminin was increased. Morphological ultrastructure changes, mainly of surface structure, were also observed. These changes suggested that RII made metastatic cells less aggressive and showed a tendency toward differentiation. After exposured to RII, different changes of oncogene and antioncogene expression of these tumor cells were detected. For example, RE caused expression of nm23in MFC cells, but down regulated (decreased) its expression in CNE2L2 cells and similar changes of rasH, fos, nm23, Rb. Expression were observed for CNE-2Z cells and its clonal variants CNE2L2 CNE2ZL2. RII down regulated both these oncogene and antioncogenes in both CNE-2Z and CNE2L2, but up regulated all of them in CNE2L4. The results indicated that oncogene and antioncogene may play different roles in different tumor cells, the same factor (RII) may lead to different changes of gene-expression in different metastatic tumor cells. So the function of oncogene and antioncogene may be of relativity and may be influenced by multifactors. Our data were mostly from in vitro experiments. It could not be deduced completely to a level as a whole in vivo.

Color Doppler ultrasonic and clinical analysis of elderly degenerative valvular disease / 第二军医大学学报

By use of color Doppler ultrasonography (ATLHDI 5000,made in USA),a prospective study was made in 362 aged (greater than or equal to 60 years) patients (252 males and 110 females) for a period of 3 years.There were 176 patients (48.2%,130 males and 46 females) had degenerative vavular disease (DVD).The incidence increased with the aging of the population.There were no evident differences between males and females.Degenerative aortic valvular deformation was most frequently found (in 171 cases),followed by mitral (in 24 cases).The complications were hypertension,diabetes and coronary heart disease.It suggests that the DVD in the elderly mainly occurs in aortic valves,then in mitral value.Its incidence increases with aging.Complications such as hypertension,diabetes and coronary heart disease are important risk factors of DVD.