OBJECTIVEThe strains of Yersinia pestis isolated in different period and different natural foci in China were analyzed.

METHODSTraditional and molecular biological methods were used. Rhamnose fermentation, rRNA gene copy number, nitrite reduction, and the glycerol fermentation were important characters for typing, and pulse field gel electrophoresis (PFGE) and random amplified polymorphic DNA (RAPD) profile could reflect the genetic distance between the strains.

RESULTSThe strains could be divided into 15 genetic types by those 6 characters with each of them covered an isolated geographical territories.

CONCLUSIONThe characters of strains were described; the genetic relationship of different types, their evolution, and the forming and shift of plague natural foci were analyzed.

China ; Databases, Genetic ; Electrophoresis, Gel, Pulsed-Field ; Genetic Drift ; Geography ; Mutation ; Random Amplified Polymorphic DNA Technique ; Yersinia pestis ; classification ; genetics ; isolation & purification

OBJECTIVETo analyze the drift of the complementarity-determining region 3 (CDR3) of T cell receptor beta (TCRbeta) chain variable region in T cells of healthy volunteers cultured with interleukin-2 (IL-2).

METHODST cells were isolated from the peripheral blood and cultured in vitro in the presence of IL-2. The non-specific killing effect of the cells was analyzed by LDH releasing assay, and the distribution of TCRbeta chain CDR3 in healthy volunteers by immunoscope spectratyping method to evaluate the clonality of the T cells.

RESULTSThe results showed Gaussian distribution of TCR Vbeta gene CDR3 in healthy volunteers. The T cell cultured with IL-2, however, displayed some anomalous and oligoclonal expansion in different TCR Vbeta families without killing effect against nasophargngal carcinoma cell line CNE2.

CONCLUSIONIL-2 may affect TCRbeta chain CDR3 distribution in T cells cultured in vitro.

Cells, Cultured ; Complementarity Determining Regions ; genetics ; Genetic Drift ; Humans ; Interleukin-2 ; metabolism ; Leukocytes, Mononuclear ; metabolism ; Receptors, Antigen, T-Cell, alpha-beta ; genetics ; T-Lymphocytes ; immunology ; metabolism

OBJECTIVETo determine the epidemiological characteristics of seasonal influenza in Shenzhen from 2005 to 2007 and the molecular variation of HA1 domain of influenza H3N2 viruses.

METHODSThe consultation rate for influenza-like illness (ILI) were calculated weekly for indicating the influenza activities (the Shenzhen Influenza Surveillance System mainly consisted of 16 institutions with 9 hospitals, 6 districts and one municipal centers of disease control and prevention). Pharyngeal swabs from the cases of ILI, which were collected during 2005 to 2007 from the city-wide and quality-controlled surveillance network, were used to propagate the viruses. The HA1 region of the influenza A/H3N2 viruses were detected by RT-PCR and sequenced subsequently. The analyses of pairwise amino acid variations, genetic clustering and phylogenetics was performed.

RESULTSThe activity levels of influenza showed certain changes during each year from 2005 to 2007, and there were summer peaks from May to July in 2006 and 2007. The positive rates of influenza virus were 4.78% (114/2385), 5.77% (212/3674) and 12.12% (343/2831) from 2005 to 2007 respectively. The weekly isolating rates changed accordingly with the trend of the percentages of ILI. The proportions of influenza H3N2 virus were 25.46% (28/114) and 2.83% (6/212) in 2005 and in 2006 respectively, but the proportion increased to 62.68% (215/343), which indicated that H3N2 virus became the predominant strain in 2007. Phylogenetic clustering analysis of influenza H3N2 virus revealed that there were 5 clades. The viruses which were isolated in 2005 contained in the clade I and II, the viruses in 2006 were comprised in clade III, and clade IV and V included the viruses isolated in 2007. Although the stem of cladogram developed with one accord of the time isolated viruses, the viruses which were similar to vaccine strains had circulated in Shenzhen before a given strain was determined as vaccine strain by WHO. It was also noticed that more amino acid changes at antigenic sites, especially at sites A and B in the H3N2 viruses, were found in 2007 than that in 2005 and in 2006. But the sequences at the receptor-binding sites and disulphide bond sites were conserved and no new circulating strain for genetic reassortment had been found in the period.

CONCLUSIONShenzhen might be one of areas where the ongoing genetic drift of influenza H3N2 viruses appeared earlier in China. The changes of influenza H3N2 virus showed the active status in the population. The results suggested that monitoring seasonal influenza viruses by sequence analysis could provide important and timely information on the appearance of strains with epidemiologic significance.

China ; epidemiology ; Genetic Drift ; Humans ; Influenza A Virus, H3N2 Subtype ; genetics ; isolation & purification ; Influenza, Human ; epidemiology ; virology ; Molecular Epidemiology ; Phylogeny ; Population Surveillance ; Sequence Analysis, RNA

Phenylketonuria is metabolic disorder that results from a deficiency of the hepatic phenylalanine hydroxylase. But among patients with hyperphenylalaninemia, the defect resides in one of the enzymes necessary for production or recycling of tetrahydrobiopterin (BH4). The reduction of BH4 affects not only phenylalanine metabolism but also formation of the tyrosine related neurotransmitter, dopamin and tryptophan related neurotransmitter, serotonin. Administration of L-dopa and 5-hydroxytriptophan seems to be the most effective treatment and may prevent irreversible neurologic damage if started early in life in hyperphenylalaninemia due to deficiency of cofactor BH4. Therefore, all patients with PKU and hyperphenylalaninemia should be tested for BH4 deficiency as early as passible. So we measured reduced forms of biopterin in urines of 19 phenylketonuria patients by Funkushima and Nixon method and 13 of PKU patients measured dihydropterin reductase (DHPR) in white blood cells by modified Narisawa method. We could not find abnormal pterin patterns of cofactor BH4 and normal value of DHPR. All Korean 19 PKU children were classic PKU. A missense mutation has been identified in the phenylalanine hydroxylase (PAH) gene of 16 Koran PKU patients. 5 mutations (IVS4, Y204 C, R243Q, Y356 X, R413 P) have been identified. The frequency of these mutations was found to be 50% of PKU alleles. The IVS4 mutation had a high frequency in Korea and southern China, due to the result of the founder effect and genetic drift. the R413 P mutation, which may have originated in the regions surrounding the Baikal, expanded to northen China and Japan. We were not able to find Caucasian mutations in Korean ptiets. PKU mutations occured after racial divergence between Caucasian and Mongoloids. We observed that PKU patients with Y 204 C and R413 P mutations showed mild mild clinical phenotype but IVS4 mutation had severe mental retardation. the establishment of genotype will therefore aid in the prediction of clinical phenotypes in patients with this disease. So, pterin and DHPR measurement and DNA analsis will be useful for prognosis and proper treatment of PKU patients.
Alleles ; Biopterin ; Child ; China ; DNA* ; Founder Effect ; Genetic Drift ; Genotype ; Humans ; Intellectual Disability ; Japan ; Korea ; Leukocytes ; Levodopa ; Metabolism ; Mutation, Missense ; Neurotransmitter Agents ; Oxidoreductases ; Phenotype ; Phenylalanine ; Phenylalanine Hydroxylase ; Phenylketonurias ; Prognosis ; Recycling ; Reference Values ; Serotonin ; Tryptophan ; Tyrosine

The identification and characterization of stem cells is a major focus of developmental biology and regenerative medicine. The advent of genetic inducible fate mapping techniques has made it possible to precisely label specific cell populations and to follow their progeny over time. When combined with advanced mathematical and statistical methods, stem cell division dynamics can be studied in new and exciting ways. Despite advances in a number of tissues, relatively little attention has been paid to stem cells in the oral epithelium. This review will focus on current knowledge about adult oral epithelial stem cells, paradigms in other epithelial stem cell systems that could facilitate new discoveries in this area and the potential roles of epithelial stem cells in oral disease.
Adult Stem Cells ; cytology ; physiology ; Animals ; Asymmetric Cell Division ; Biomarkers ; Cell Proliferation ; Clone Cells ; Epithelial Cells ; cytology ; Genetic Drift ; Humans ; Mouth Mucosa ; cytology ; Mouth Neoplasms ; pathology ; Neoplastic Stem Cells

OBJECTIVETo understand the molecular biological characteristics in order to analyse the genetic background of Yersinia pestis in China.

METHODSPrimary datum on ribotyping, pulsed field gene electrophoresis (PFGE), random amplified polymorphic DNA (RAPD) and insertion sequence (IS) of Yersinia pestis were used and under cluster analysis. Genetic interval and various methods of recognized molecular feature between different strains were evaluated.

RESULTSRibotypes the PFGE types seemed to be corresponding. Stains from Microtus fuscus and area in Tibet Zhongba belonged to 7 copy rRNA gene and the genetic interval were the far more with 6 copy rRNA gene stains, and not definite with RAPD, but with many exceptions. The genetic interval between strains were showed by resemble value.

CONCLUSIONYersinia pestis in China had its own manifold, particular molecular biological characteristics due to natural barriers, geographical complex, circumstances in Tianshan Mountains and Gandise Mountains areas. Yersinia pestis were limited to separateness, evoluted only in certain areas to form a great many gene types.

Animals ; China ; Cluster Analysis ; DNA, Bacterial ; genetics ; Electrophoresis, Gel, Pulsed-Field ; Genetic Drift ; Genotype ; Geography ; Humans ; Mice ; Random Amplified Polymorphic DNA Technique ; Ribotyping ; Yersinia pestis ; classification ; genetics ; isolation & purification

The porcine reproductive and respiratory syndrome virus (PRRSV) is a globally ubiquitous swine viral pathogen that causes major economic losses worldwide. We previously reported an over-attenuated phenotype of cell-adapted PRRSV strain CA-2-P100 in vivo. In the present study, CA-2-P100 was serially propagated in cultured porcine alveolar macrophage (PAM) cells for up to 20 passages to obtain the derivative strain CA-2-MP120. Animal inoculation studies revealed that both CA-2-P100 and CA-2-MP120 had decreased virulence, eliciting weight gains, body temperatures, and histopathologic lesions similar to those in the negative control group. However, compared to CA-2-P100 infection, CA-2-MP120 yielded consistently higher viremia kinetics and enhanced antibody responses in pigs. All pigs inoculated with CA-2-MP120 developed viremia and seroconverted to PRRSV. During 20 passages in PAM cells, CA-2-MP120 acquired 15 amino acid changes that were mostly distributed in nsp2 and minor structural protein-coding regions. Among these changes, 6 mutations represented reversions to the sequences of the reference CA-2 and parental CA-2-P20 strains. These genetic drifts may be hypothetical molecular markers associated with PRRSV macrophage tropism and virulence. Our results indicate that the PAM-passaged CA-2-MP120 strain is a potential candidate for developing a live, attenuated PRRSV vaccine.
Animals ; Antibody Formation ; Body Temperature ; Genetic Drift ; Humans ; Kinetics ; Macrophages ; Macrophages, Alveolar ; Parents ; Phenotype ; Porcine Reproductive and Respiratory Syndrome ; Porcine respiratory and reproductive syndrome virus ; Swine ; Tropism ; Vaccines, Attenuated ; Viremia ; Virulence ; Weight Gain

OBJECTIVETo study the relationship between influenza epidemic and genetic characteristic on HA and NA regions of influenza virus subtype A3 isolates of Zhejiang province in the recent years.

METHODSRNA of 25 influenza virus subtype A3 isolates, circulated in Zhejiang province during 1998 to 2005, was extracted. HA1 and NA regions were amplified and sequenced. All the sequence data were analyzed using BioEdit.

RESULTSHA1 and NA regions of all the isolates belonged to 987nt and 1362nt, encoding protein of 329 and 454 amino acids respectively. Isolates shared amino acid homology of 90.9%-99.3% and 95.2%-99.5% on HA1 and NA regions, while divergence on HA1 was greater than that on NA region. During a period of 8 years, 30 amino acids on HA1 region were substituted and 14 of which refer to 4 antigenic determinant sites. Meanwhile,21 amino acids on NA region were substituted and 5 of which referred to 3 antigenic determinant sites. Significant divergences, both in HA1 and NA, were observed among isolates in 1998 and 2002, showing that they belonged to absolutely different branches. Additionally, influenza virus subtype A3 isolates identified in recent years, with 11 N-linked glyeosylation sites in HA1 region, had 5 sites more than early A/Aichi/2/68 strain. Since 1998,3 sites had been inserted in epidemic strains, indicating the accelerated trend of glyeosylation sites were increasing.

CONCLUSIONThere is a correlation between antigenic drift of influenza virus subtype A3 and the two epidemics in Zhejiang province in 1998 and 2002.

Amino Acid Sequence ; Antigens, Viral ; genetics ; China ; Epitopes ; genetics ; Evolution, Molecular ; Genetic Drift ; Hemagglutinin Glycoproteins, Influenza Virus ; genetics ; Humans ; Influenza A virus ; genetics ; isolation & purification ; Influenza, Human ; epidemiology ; Molecular Sequence Data ; Neuraminidase ; genetics ; RNA, Viral ; genetics ; Sequence Analysis, RNA ; Sequence Homology, Amino Acid

OBJECTIVETo understand the genotype characteristics and its evolution of patients with poor response to initial combined treatment of Lamivudine and Adefovir dipivoxil for chronic hepatitis B.

METHODSWe detected the HBV genotypes of three patients-S1, S2, S3, who with poor response to initial treatment of Lamivudine and Adefovir dipivoxil for chronic hepatitis B over 12 months by the application of cloning and sequencing method at the time point of baseline,4 weeks after treatment, 12 weeks, 24 weeks, 48 weeks, 60 weeks. 25 clones were randomly selected to identify and sequence at each time point.

RESULTSThe total number of clones from 3 patients with poor response to initial combined treatment of Lamivudine and Adefovir dipivoxil for chronic hepatitis B at each time point was 398. About patient S1 at baseline, genotype C accounting for 8.3%, genotype B, for 91.7%, so genotype B was in dominant (22/24). But genotype C has gradually developed to 100% after treatment for 60 weeks. About patient S2 and S3, genotype B was the only type at baseline. However type B has gradually "drift" to type C during treatment. When treatment for 60 weeks, type C has taken the absolute advantage 75% for S2, and 100% for S3.

CONCLUSIONSThe cloning and sequencing can represent the overall genotype level better. HBV genotype has performed the evolution trend that genotype has drifted from B to C during long-term drug pressure, which is the main reason for poor response to initial combined treatment of Lamivudine and Adefovir dipivoxil for chronic hepatitis B.

Adenine ; analogs & derivatives ; therapeutic use ; Adult ; Antiviral Agents ; therapeutic use ; Drug Resistance, Viral ; Evolution, Molecular ; Female ; Genetic Drift ; Genotype ; Hepatitis B virus ; drug effects ; genetics ; isolation & purification ; Hepatitis B, Chronic ; drug therapy ; virology ; Humans ; Lamivudine ; therapeutic use ; Male ; Middle Aged ; Organophosphonates ; therapeutic use