[Molecular epidemiological analysis of ECHO7 virus isolated from sewage water in Yunnan Province, China]

To investigate the epidemic and evolutionary trends of enterovirus (EV) in the external environment of Yunnan Province, China, molecular typing was performed on 4 EV strains that were isolated from environmental sewage in Yunnan. The VP1 region of isolates was amplified by RT-PCR using universal enterovirus primers, and the amplified VP1 region was sequenced for GenBank BLAST search and genotype analysis. The 4 EV strains were identified as ECHO7. Their nucleotide and amino acid homologies with the VP1 sequences of 68 ECHO7 strains retrieved from GenBank were measured by Mega software analysis. Our findings showed that ECHO7 strains from environmental sewage and population samples were in different evolutionary branches. These strains showed typical geographical and temporal differences; In addition, there were different transmission chains at the same time and in the same area. ECHO7 strains isolated from sewage water and patients with acute flaccid paralysis during the same period in Yunnan belonged to different clusters and evolved at different speeds. Special concerns are needed for this problem. Continuous molecular biological surveillance of human EV in the external environment of Yunnan will provide strong support for early warning of EV diseases.

[Study on the molecular typing and epidemiology of non-polio enterovirus in Yunnan Province, China during 2006-2010]

In order to explore the genotype distribution and molecular evolution of non-polio enterovirus (NPEVs)in Yunnan Province,the People's Republic of China, we sequenced and analyzed the partial VP1 coding region of 105 NPEVs isolated from acute flaccid paralysis (AFP) surveillance in Yunnan province during a 5- year study period from 2006 to 2010. The viral genomes of 105 NPEVs were translated to corresponding amino acid sequences and compared with those of the prototype strains, and the phylogenetic tree was constructed among these VP1 nucleotide sequences and other prototype strains from GenBank. Analysis showed that 18 isolates were classified into 7 serotypes of human enterovirus A species, while 77 isolates into 22 serotypes of B and 10 isolates into 4 serotypes of C species. However, we did not isolate any viruses which belonged to human enterovirus D species. Thus, under AFP surveillance, human enterovirus B species accounted for 73. 3% of the 105 isolates and was considered as the predominant one,followed by human enterovirus A(17. 1%) and human enterovirus C(9. 5%). Phylogenetic analysis showed that various serotypes of the virus and the corresponding prototype strains or other representative strains clustered into the same grooup, however, Yunnan strains and prototype strains were located in the different branches (except CA2,EV90 and EV76). The degree of variation was different even among the same genotype strains. This report showed that different genotype strains spread widely in Yunnan Province.

[Genetic characteristics of EV71 in Yunnan Province from 2009 to 2010]

In order to learn about the genetic characteristic of human enterovirus type71 (HEV71) isolated from cases of Hand, Foot and Mouth Disease (HFMD) in Yunnan Province from 2009 to 2010. 50 isolates form HFMD cases were performed entire VP1 coding region amplification by reverse transcription-polymerase chain reaction and sequencing the nucleotide sequences; then the phylogenetic tree was constructed. The complete nucleotide sequences of region VP1 of the 50 strains were all 891nt length coding 297 amino acids. The result of molecular identification of the 50 strains is HEV71. Phylogenetic analysis indicated that 48 EV71 isolates belonged to subgenotype C4a and 2 EV71 isolates belonged to genotype A. From 2009 to 2010, the pathogen of HFMD cases were EV71 strains in Yunnan province, which were co-evolved with isolates from other provinces in mainland of China. There was no significant difference found in the whole sequence of VP1 gene of the strains isolated from different regions or under different diseases occurred, but the spread of genetype A appared in Yunnan Province in 2009.

[Molecular typing of enteroviruses from healthy children in the border areas of Yunnan Province and Myanmar and the genetic characteristics of ECHO7 and ECHO13 in 2009]

To explore the enteroviruses surveillance among healthy children under 15 years old in the border areas of Yunnan Province and Myanmar in 2009. The stool samples were collected from the healthy children under 15 years old who came from the border areas of Myanmar and Yunnan Province, virus isolation and sequencing were conducted for all the 271 samples. 6 strains of polioviruses (PVs) were detected from 271 stools with an isolation rate of 2.8%, which belonged to vaccine strains and 24 non-polioviruses (NPVs) were detected with an isolation rate of 8.9%. 24 NPVs belonged to human enterovirus group B (HEV-B) with 6 serotypes, HEV-A, HEV-C and HEV-D viruses were not isolated. Among them, 13 NPVs were E7 (54.17%) and 5 NPVs were E13 (20.83%). Our results showed that the enterovirus carrying rate in the border areas of Yunnan province was higher than the rate of routine acute flaccid paralysis (AFP) detection system. The HEV-B viruses were the only enteroviruses isolated. The phylogenetical analysis showed that Echovirus 7(E7) and 13 (E13) exhibited genetic polymorphism.

[Molecular identification of hepatitis B virus genotype I in Yunnan Province, the People's Republic of China]

Molecular typing was conducted according to the reported method for one HBsAg positive carrier who had a physical examination in Yunnan Province. The S gene of this HBV sample was amplified by nested PCR and the PCR products were directly sequenced. Blast searching was done on the Genbank database and the sequence were compared with the HBV reference sequences in database. The phylogenetic tree was constructed. Homology analysis of nucleotide and smino acid were performed between the sequences from the sample and the reference sequences corresponding to HBV genotype A to I. Analysis of nucleotide and amino acid identities suggested that the sample belonged to HBV genotype I. The HBV genotype I is the first reported in China.

[Investigation on one vaccine-derived poliovirus (VDPV) case in Yunnan Province]

To find out epidemiological feature of paralytic cases caused by type 2 vaccine-derived poliovirus (VDPV) and the excretion status of the case and to explore the enterovirus infection status among healthy children under five years old around the case in Zhaotong city, Yunnan Province in 2010. Field epidemiological studies at the epidemic area were conducted and a total of 108 stool samples were collected, three from the case, seven from the close contacts and 98 from the healthy children. VDPV was not isolated again from the case; Sabin-like PV strains or VDPV were not isolated from the close contacts and the healthy children; An active search for acute flaccid paralysis cases was conducted in the area, which indicated that the VDPV did not cause virus circulation in local area. Twenty one (20.0%) NPEVs were isolated from 105 stool samples. Among the 21 NPEV isolates, 11 isolates (52.4%) were HEV-A (3 serotypes), 10 isolates (47.6%) were HEV-B (4 serotypes).

[Molecular identification of human enterovirus 73 in Yunnan Province, the People's Republic of China]

Molecular typing was conducted according to the reported methods for 2 enteroviruses that were isolated from healthy children in the border areas of Yunnan Province with Myanmar. RT-PCR and sequencing were performed with 292/222 primers according to the Oberste's methods. The resulting sequences were blasted against the Genbank database and compared with all available enterovirus database. Analysis of homology at nucleotide and amino acid level identically suggested that the two enteroviruses are human enterovirus 73.

[Effects of ciwujia (Acanthopanax senticosus Harms) on reperfusion-induced arrhythmia and action potential alterations in the isolated rat heart]

By means of Langendorff method and standard microelectrode techniques the effects of Ciwujia on reperfusion induced arrhythmias and action potential alterations were studied in isolated rat heart with transient coronary occlusion. Inclusion of Ciwujia extract (equivalent to 1.2 and 2.4 mg crude drug/ml) was found helpful in reducing reperfusion induced ventricular fibrillation and ventricular tachycardia. Associated with this reduction in rhythm disturbances was an increase in the total duration of normal sinus rhythm during the 3 min reperfusion period. With the administration of Ciwujia the number of cells with abnormal action potential configurations was significantly reduced. This confirms that Ciwujia can protect myocardium from electrophysiological abnormalities, and therefore reduces the incidence of malignant arrhythmias.