Animals ; History, 20th Century ; Hong Kong ; epidemiology ; Humans ; Influenza A Virus, H3N2 Subtype ; classification ; genetics ; isolation & purification ; Influenza, Human ; epidemiology ; history ; virology ; Molecular Sequence Data ; Phylogeny

To optimize the ethanol extraction technology parameters of Fengyin Decoction by orthogonal experiment combined with beetle antennae search(BAS)-genetic algorithm(GA)-back propagation neural network(BPNN). Based on single factor investigation, the extraction temperature, ethanol volume, extraction time, and ethanol concentration were used as orthogonal experiment factors, and entropy weight method was used to calculate the comprehensive scores of aloe-emodin, glycyrrhizic acid ammonium salt, rhein, emodin, chrysophanol, physcion, cinnamaldehyde, 6-gingerol, extraction ratio and fingerprint similarity. BAS-BPNN model was established, and then, GA was used to predict the optimal extraction process. The results showed that BAS-BPNN was optimized to obtain the optimal ethanol extraction process of Fengyin Decoction as follows: extraction temperature of 87 ℃, adding 9 times of 75 % ethanol, and extracting for 47 minutes, with a comprehensive score of 1.052 9. Meanwhile, the optimal process parameters obtained by orthogonal design were as follows: the extraction temperature of 80 ℃, adding 10 times of 75% ethanol, extracting for 30 minutes, with a comprehensive score of 1.003 7. The comprehensive score of the process obtained from the BAS-BPNN model was slightly better than that from the orthogonal test, indicating that the optimized process from BAS-BPNN model was more ideal, so it was finally determined as the best extraction process for Fengyin Decoction. The process of Fengyin Decoction obtained from BAS-GA-BPNN has high extraction efficiency and good stability, which provides reference for the subsequent development and quality control.
Drugs, Chinese Herbal ; Entropy ; Ethanol ; Neural Networks, Computer ; Quality Control

BACKGROUNDTo establish a method for H5N1 RNA detection and laboratory diagnosis of suspected human avian influenza (H5N1) virus infected cases.

METHODSThe typing and sub-typing primers were designed according to M and H5 and N1 gene respectively, and the RT-PCR and real-time PCR were developed using these primers.

RESULTSThe RT-PCR and real-time PCR could be used for H5N1 detection specifically, and there was no cross reaction with other influenza subtypes such as H1 and H3. The sensitivity for RT-PCR and real-time PCR was 1 TCID50 and 0.01 TCID50 respectively. Thirteen laboratory confirmed human H5N1 cases were detected from 42 suspected cases by using these methods.

CONCLUSIONThe established RT-PCR and real-time PCR methods can be used for laboratory detection of suspected human H5N1 cases.

Animals ; Chick Embryo ; DNA Primers ; genetics ; Humans ; Influenza A Virus, H5N1 Subtype ; genetics ; isolation & purification ; Influenza, Human ; diagnosis ; virology ; Reproducibility of Results ; Reverse Transcriptase Polymerase Chain Reaction ; methods ; Sensitivity and Specificity ; Viral Proteins ; genetics

BACKGROUNDTo study the incidence of adamantane resistance among influenza A (H3N2) viruses isolated from the mainland of China since 1989 through our influenza surveillance system, and to provide more information for the clinical usage of adamantane drugs.

METHODSTotally 584 influenza A (H3N2) virus strains were randomly selected from our surveillance network since 1989, the adamantane drug resistance related gene M2 of all 584 strains was sequenced, and the drug sensitivity of viruses was also assayed by using biological methods in cells.

RESULTSNo adamantane resistant strains were detected among the strains isolated from 1989 to 1999, but there was a surprisingly increased resistance rate of 56% in 2003 compared with 3.4% in 2002, and in 2005 the resistance rate increased to 77.6%.

CONCLUSIONOver 50% of virus among the strains isolated showed adamantane resistance since 2003, and the incidence rate is increasing.

Adamantane ; pharmacology ; Animals ; Antiviral Agents ; pharmacology ; Chick Embryo ; China ; Drug Resistance, Viral ; Influenza A Virus, H3N2 Subtype ; drug effects ; genetics ; isolation & purification ; RNA, Viral ; genetics ; isolation & purification ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Analysis, DNA ; Viral Matrix Proteins ; genetics

BACKGROUNDTo analyze the genetic and antigenic characteristics of human H5N1 virus isolated from the mainland of China.

METHODSThe hemagglutinin (HA) gene of human H5N1 virus were sequenced and analyzed.

RESULTSThe results of HA gene sequencing showed that all the virus isolates belong to the same group because of the high similarity, but they were different from the virus isolated from Thailand and Vietnam. The sequence data also showed that the receptor specificity and the connecting peptide between HA1 and HA2 are still avian influenza origin.

CONCLUSIONThe virus isolates from mainland of China until now belong to the same group and are different from the virus isolated from Thailand and Vietnam, and there is no evidence showing the human-avian influenza reassortant and recombination.

Animals ; Chick Embryo ; China ; Hemagglutinin Glycoproteins, Influenza Virus ; genetics ; Humans ; Influenza A Virus, H5N1 Subtype ; classification ; genetics ; isolation & purification ; Influenza, Human ; virology ; Phylogeny ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Analysis, DNA

The NA genes of 395 strains of human H3N2 influenza virus isolated from 1996 to 2005 in China were sequenced, analyzed with bioinformatics tools. The NA nucleotide sequence of phylogenetic tree showed a main evolution branch with multiple short side branches. The strains in the same year may be divided into several branches. There was an obvious lag between vaccine strains recommended by WHO and the Chinese circulating strains in phylogenetic tree of the NA nucleotide. The result also showed no amino acid deletion and insertion in the NA. In NA antigen sites, where including residues 197-199 aa, 431-434 aa and 339-347aa the mutation was higher, in contrast, the residues including 153 aa, 328-336 aa, 367-370aa and 400-403 aa, the mutation was lower. Besides the antigenic determinant sites, there also had the other amino acid mutated highly, such as 18, 23, 30, 93, 143, 208, 216, 221, 249, 265, 267, 307, 385 and 437 aa, among them 143 and 267 mutation were higher than that in antigenic determinant sites, their biological significance are not clear yet. The neuraminidase active-site residues in NA were highly conservative and the same were the disulphide bond and the glycosylation sites in NA. In conclusion, our analysis provides some information for influenza prevention and control and the NA inhibitor medicine application.
China ; Genes, Viral ; Humans ; Influenza A Virus, H3N2 Subtype ; genetics ; Mutation ; Neuraminidase ; genetics ; Phylogeny ; Time Factors

To study the correlation of human influenza A/H3N2 hemagglutinin gene variation and the epidemic from 1995 to 2005 in China, 550 HA1 sequences of H3N2 viruses isolated in China were analyzed with phylogenetic tree. The results showed that the evolution of HA1 represented a long trunk with short side branches. The animo acid changes of HA1 mostly located at the antigenic sites or aside of them, but also may occur at the other sites simultaneously. The analysis also showed three possibilities of HA1 variation to cause H3N2 epidemic, the first is multiple site mutations happened simultaneously; the second is mutation sites happened gradually and then accumulated to multiple sites; the third is a single antigenic site mutation occurred simultaneously with the receptor binding site variation.
China ; Disease Outbreaks ; Genes, Viral ; Genetic Variation ; Hemagglutinin Glycoproteins, Influenza Virus ; genetics ; Humans ; Influenza A Virus, H3N2 Subtype ; genetics ; Influenza, Human ; epidemiology ; Mutation ; Time Factors

A new flu caused by a novel influenza A(H1N1) virus has spread over the United States, Mexico and more than 40 other countries. And because of the immediate global concern, WHO has announced that the current level of influenza pandemic alert is raised to phase 5, indicating approaching of an influenza pandemic. As patients suffering from the influenza A (H1N1) have the similar symptoms as patients with seasonal influenza, differential detection and identification of the influenza virus have to depend on specific laboratory tests. We have successfully developed a RT-PCR based method for detection of the influenza A (H1N1) virus, and had applied the method to detection of clinical samples.
Humans ; Influenza A Virus, H1N1 Subtype ; genetics ; isolation & purification ; Influenza, Human ; virology ; RNA, Viral ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; methods

The clinical throat swab specimen of an imported suspected case of influenza A (H1N1) was detec ted with real-time PCR, RT-PCR and subsequently confirmed by gene sequencing. The presence of influ enza A (H1N1) virus confirmed the first case with A (H1N1) infection in Mainland China.
China ; Humans ; Influenza A Virus, H1N1 Subtype ; classification ; genetics ; isolation & purification ; Influenza, Human ; virology ; Molecular Sequence Data ; Phylogeny

Chrysosplenium nudicaule,Tibetan name " Yajima",is recorded as an effective medicine for the treatment of liver and gallbladder diseases by Tibetan Pharmacopoeia published in the past dynasties,but its traditional efficacy has not yet been investigated by means of modern pharmacological research methods. In this paper,the protective effect of extract of C. nudicaule(ECN) on liver injury in mice was observed by using the mice model of intrahepatic cholestasis(IC) induced by α-naphthyl isothiocyanate(ANIT) and the possible mechanism by which ECN work as the therapeutic agent was discussed. The results showed that the serum levels of AST,ALT,ALP,DBIL,TBIL and TBA of the model mice were notably reduced in dose-dependent manner(P<0. 01,P<0. 05). The activity of SOD and GSH-Px in the liver homogenate of mice was increased,while the content of MDA was decreased(P<0. 01,P<0. 05).Pathological examination of liver in mice showed that ECN could improve the pathological changes of liver tissue in mice. The mRNA expression level of genes related to bile acid metabolism were detected by RT-PCR and the results suggested that ECN could significantly increase the expression of genes such as BSEP,FXR and MRP2(P<0. 01,P<0. 05),meanwhile significantly reduce the expression of CYP7 A1(P<0. 01,P<0. 05). These results confirmed the protective effect of ECN on intrahepatic cholestasis-induced liver injury in mice,and indicated that the mechanism may be related to activating FXR and its target genes,reducing bile acid synthesis and increasing bile acid excretion. This study provides a modern pharmacological basis for the clinical application of Yajima in Tibetan medicine.
Animals ; Cholestasis, Intrahepatic ; chemically induced ; drug therapy ; Liver ; Medicine, Tibetan Traditional ; Mice ; Plant Preparations ; pharmacology ; Saxifragaceae ; chemistry