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Biomedical subjects

Yan Zhao

Publications and source records attributed to Yan Zhao.

At least 73 records · Page 4Linked to original sources
PubMed2006

Physical and genetic map of the Spiroplasma kunkelii CR2-3x chromosome.

Spiroplasma kunkelii (class Mollicutes) is the characteristically helical, wall-less bacterium that causes corn stunt disease. A combination of restriction enzyme analysis, pulsed-field gel electrophoresis (PFGE), and Southern hybridization analysis was used to construct a physical and genetic map of the S. kunkelii CR2-3x chromosome. The order of restriction fragments on the map was determined by analyses of reciprocal endonuclease double digests employing I-CeuI, AscI, ApaI, EagI, SmaI, BssHII, BglI, and SalI; adjacent fragments were identified on two-dimensional pulsed-field electrophoresis gels. The size of the chromosome was estimated at 1550 kb. Oligonucleotide pairs were designed to prime the amplification of 26 S. kunkelii gene sequences in the polymerase chain reaction (PCR). Using PCR amplicons as probes, the locations of 27 S. kunkelii putative single-copy genes were positioned on the map by Southern hybridization analyses of chromosomal fragments separated in PFGE. The nucleotide sequence of the single ribosomal RNA operon was determined and its location mapped to a chromosomal segment bearing recognition sites for SalI, SmaI, EagI, and I-CeuI.

Blotting, Southern↗
PubMed2006

[Y-SNP analysis of Bouyei, Gelao, Mulao, Maonan, and Zhuang populations in Guizhou].

To understand the patrilineal genetic structure of Baiyue ethnic group in Guizhou province, we studied the frequencies of Y-chromosome haplotypes which consisted of 10 single nucleotide polymorphisms (SNPs) by using the PCR-RFLP method. Five haplotypes were found in Baiyue ethnic group in Guizhou, among which H8 was the most common, whereas that of Miao in Guizhou tended to be H8, H11 and H12 haplotypes. Compared with Miao in Guizhou, the Guizhou Baiyue (excluding Sui and Dong) was significantly different and could be regarded as an independent ethnic group. Differences were also found in the same ethnic group among different areas.

Asian People↗
PubMed2006

A fluorescent chemosensor for copper(II) based on a carboxylic acid-functionalized tris(2,2'-bipyridine)-ruthenium(II) complex.

In this research, bis(2,2'-bipyridine)(4-methyl-2,2'-bipyridine-4'-carboxylic acid)ruthenium(II).2PF(6)- complex (1), was first used as a fluorescent chemosensor to recognize Cu(II) in EtOH/H(2)O (1:1, v/v) solution. The response of the sensor is based on the fluorescence quenching of complex 1 by binding with Cu(II). The analytical performance characteristics of the proposed Cu(II)-sensitive chemosensor were investigated. The sensor can be applied to the quantification of Cu(II) with a linear range covering from 5.0 x 10(-8) to 1.0 x 10(-4) M and a detection limit of 4.2 x 10(-8) M. The experiment results show that the response behavior of 1 to Cu(II) is pH independent in medium condition (pH 4.0 - 8.0), and show excellent selectivity for Cu(II) over other transition metal cations.

2,2'-Dipyridyl↗
PubMed2006

Chiral separation of synthetic vicinal diol compounds by capillary zone electrophoresis with borate buffer and beta-cyclodextrin as buffer additive.

The investigation on capillary electrophoretic enantioseparation of six synthetic compounds containing vicinal diol groups has been undertaken to acquire the optimum conditions using native beta-cyclodextrin (beta-CD) as chiral selector and borate as a background electrolyte. The separation was carried out in an uncoated capillary (58.5 cm x 75 microm i.d., effective length 48.5 cm) and the effects of several important factors were investigated in detail. The results showed that beta-CD as a chiral selector exhibited good enantioselectivity and that the enantioseparation was greatly influenced by the structure of the diols, the borate concentration and the buffer pH. The optimum performance was obtained for the chiral vicinal diols under the conditions of 200 mM borate buffer of pH 9.8 containing 1.7% beta-CD at an applied voltage of 15 kV and a capillary temperature of 20 degrees C. Under the conditions, four diols were baseline separated with fast analysis time and the good theoretical plate numbers (above 10 x 10(4)) and favorable migration-time reproducibilities (RSDs below 3.0%) were obtained. The separation results were satisfactory.

Borates↗
PubMed2006

[Analysis of polymorphisms in Y-DNA haplotypes and mtDNA haplogroups in Yao ethnic group from Guizho].

The frequencies of Y-chromosome haplotypes consisting of 12 single nucleotide polymorphisms (SNP) and mitochondrial DNA (mtDNA) haplotypes consisting of 9 SNPs were investigated using PCR-RFLP in 97 Yaos from Guizhou to study the patrilineal and matrilineal genetic structure and the origin of Yao Ethnic Group from Guizhou. Results showed that all 97 samples were classified into 4 Y-DNA haplotypes (H7, H8, H9 and H11). The major haplotype H7 of Hmong-Mien Population was highly prevalent (92.4%) in Yaos from Guizhou. Eight mtDNA haplotypes were identified through mtDNA analysis and all the haplotypes could be classified into 5 haplogroups (B4, B5, D4, D5 and N*) that were defined previously. The frequency of a 9-bp deletion in the human mtDNA Co II/tRNALys intergenic region was 58.2% in the 97 samples. These data suggest that the patrilineal genetic structure of Yao ethnic group from Guizhou was simple and Yaos from Guizhou had the typical genetic character of the Hmong-Mien Population and some admixture with other populations. The matrilineal genetic structure of Yaos from Guizhou was relatively complex and the 9-bp deletion was a characteristic genetic marker of the matrilineal genetic structure of Yaos from Guizhou.

Asian People↗
PubMed2006

[The relationship between lymphangiogenesis and lymphatic metastasis in murine hepatic carcinoma of high and low metastatic potentialities].

OBJECTIVES: To study the relationship between lymphangiogenesis and lymphatic metastasis in mice bearing hepatic carcinoma and analyze the mechanism of the lymphatic metastasis. METHODS: Hepatic carcinoma cell lines of high and low potentialities of lymphatic metastasis were injected into the footpads of Balb/c mice. Their metastases to lymph nodes were examined. The tumor tissues of each group were stained with 5'-nucleotidase-ALP to observe the lymphoangiogenesis. The total RNA of high and low metastatic potential cell lines were extracted for metastasis gene DNA array. The vascular endothelial cell growth factor C (VEGF-C) and VEGF-D of each cell line were detected using semi-quantitative RT-PCR and were further quantatively analyzed using real time PCR. RESULTS: The para-common iliac a. and renal hilar lymph nodes metastases of the high metastatic potential cells were significantly higher than in the controls (P>0.05). The quantity of lymphatic vessels in the high metastasis group was significantly larger than that of the control group (P<0.05). The expressions of CD44, E-cadherin, HER2/neu, H-Ras and VEGF-C in the high metastasis group were higher than those in the low metastasis group shown by the cDNA micro array experiment but the expressions of nm23A, nm23-E4, p16ink4a, CD61 were lower. The VEGF-C expression was higher and the VEGF-D was lower in the high metastasis group compared to those of the low metastasis group shown by semi-quantitative RT-PCR. The secretion of VEGF-D was significantly lower and the ratio of VEGF-C/VEGF-D was significantly higher in the high metastasis group than the low metastasis group (P<0.05). CONCLUSIONS: The lymphatic metastasis of hepatic carcinoma is related to lymphoangiogenesis. The changes of VEGF-C and VEGF-D expressions might be a cause influencing the lymphoangiogenesis. VEGF-C/VEGF-D might be an effective parameter in affecting lymphatic metastases.

Animals↗
PubMed2006

[Prevalence of sensitization to aeroallergens in Beijing patients with allergic rhinitis].

OBJECTIVES: The purpose of this study was to determine which aeroallergens were prevalent in patients with allergic rhinitis in Beijing. METHOD: A total of 554 cases (female: 212, male: 342, aged between 4-69 years) who were diagnosed with allergic rhinitis by history and clinical presentation, underwent a skin prick test with 20 standardized aeroallergens, and the important sensitizing allergens were assessed. The samples were stratified on two age groups: 4-18-year-olds (children group, n = 81) and 19-60-year-olds (adults group, n = 401). Difference of SPT responses of the two groups was investigated. RESULT: The percent of patients with positive skin tests were follow:D. farinae (64.6%), D. pteronyssinus (64.3%), Flowers pollen (28.7%), Herbs (26.5%), Lamb's Quarters (13.7%) ,Tree II (13.5%), Giant Ragweed (12.5%). Tree I (12.5%) There were significantly higher sensitivity to dust mite among children group compared to adults group (P < 0.01). CONCLUSION: The study shows that the dust mite, Flowers pollen and Herbs are the most important three aeroallergens in Beijing region.

Adolescent↗
PubMed2006

[Isolation and physiological characterization of mesenteric arterial smooth muscle cells].

Vascular smooth muscle cells (VSMCs) are crucial for studying the mechanism and regulation of vasogenic response, but so far no ideal method has been reported for their isolation. We established a VMSC isolation method based on two-step digestion, with which a large population of single smooth muscle cells could be obtained. After cell isolation, the potassium current, cytosolic calcium concentration, reactivity to caffeine were measured, and the results demonstrated that the cells were highly viable and exhibited reactivity to the vascular constrictor to meet various needs in experimental research.

Animals↗
PubMed2006

[Microbial community structure in different wastewater treatment processes characterized by single-strand-conformation polymorphism (SSCP) technique].

In order to investigate microbial community structures in different wastewater treatment processes and understand the relationship between the structures and the status of processes, the microbial community diversity, variety and distribution in five wastewater treatment processes were studied by a culture-independent genetic fingerprinting technique single-strand-conformation polymorphism (SSCP). The five processes included a denitrification and phosphorus removal bioreactor (N), Chinese traditional medicine wastewater treatment bioreactor (P), beer wastewater treatment bioreactor (W), fermentative biohydrogen production bioreactor (H) and sulfate-reduction bioreactor (S). The results indicate that the microbial community profiles in the same wastewater bioreactors are very similar. The diversity of microbial populations is correlated with the complexity of organic contaminants in wastewater. Chinese traditional medicine wastewater contains more complex organic components, so the population diversity is higher than that of simple nutrient bioreactors fed with molasses wastewater. Compared with the strain bands in a simulated community, the relative proportion of some functional microbial populations in bioreactors was not dominant, namely, fermentative biohydrogen producer Ethanologenbacterium sp. in the better condition bioreactor had only 5% band density, and the Desulfovibrio sp. in the sulfate-reducing bioreactor had less than 1.5% band density. SSCP profiles can define the difference in microbial community structures in wastewater treatment processes and monitor some of the functional microbes in these processes, providing useful guidance for improving its efficiency.

Bacteria↗
PubMed2006

[The relationship between early childhood caries and child temperament].

OBJECTIVE: To evaluate the differences in temperament between children with early childhood caries (ECC) and an age-matched children without ECC. METHODS: A total of 219 3-year-old children were selected in urban areas of Beijing, who were physically and mentally healthy. There were 109 children in ECC group, who had unfilled caries in 1 or more surfaces in primary maxillary anterior teeth, and 110 children without caries. The children were examined for ECC levels, and their parents were asked to complete the NYLS Temperament Scale questionnaire. Then the data was collected and analyzed. RESULTS: Children with difficult, intermediate high or slow-to-warm-up temperament had more severe caries than children with easy or intermediate low temperament. There was a significant difference in temperament attribute "Activity level" between male children with ECC and without ECC. There was a significant difference in temperament attribute "Rhythmicity" between female children with ECC and without ECC. CONCLUSIONS: There were some differences in temperament between 3-year-old children with ECC and without ECC in urban areas of Beijing.

Child, Preschool↗
PubMed2006

[Comparison of immunological profiles between pediatric and adult patients with AIDS in China].

OBJECTIVE: To compare the immunological profiles of pediatric and adult patients with AIDS in China. METHODS: Totally 103 pediatric AIDS patients, 38 adult patients, 88 healthy children, and 72 healthy adults were enrolled. CD4 + T lymphocyte counts were determined by four-color flow cytometer and HIV-RNA levels were measured in EDTA plasma by quantitative reverse-transcription polymerase chain reaction (RT-PCR). Plasma levels of interleukin (IL)-10, IL-16, IL-18, regulated upon activation, normal T-cell expressed and secreted (RANTES), monocyte chemoattractant protein 1 (MCP-1), stromal cell-derived factor-(SDF-1) alpha, SDF-1 beta, and macrophage stimulate protein (MSP) were quantified by enzyme-linked immunosorbent assay (ELISA). The levels of beta 2-microglobulin (beta 2-MG) and soluble Fas (sFas) were measured to indicate the activation of immune system. RESULTS: The mean CD4 + T cell count in pediatric patients with AIDS was significantly lower than in healthy children (P < 0.01), as between the adult AIDS patients and healthy adults (P < 0.01). The mean levels of these cytokines in pediatric patients were significantly higher than in healthy children (P < 0.01). The level of MSP in adult patients was significantly lower than in healthy adults and other cytokines were significantly higher (P < 0.01). The mean levels of these cytokines, except SDF1 alpha and beta 2-MG, were significantly higher in pediatric patients than in adult patients (P < 0.01). CONCLUSION: Abnormal immune activation is induced in both pediatric and adult patients with HIV-1 infection. The level of immune activation is higher in pediatric patients than in adult patients.

Acquired Immunodeficiency Syndrome↗
PubMed2006

[Epidemiology of pediatric HIV infection in six provinces of China].

OBJECTIVE: To investigate the epidemiology of pediatric human immunodeficiency virus (HIV) infection in six provinces of China. METHODS: A cross-sectional study was conducted in six provinces with the highest HIV prevalence. Surveys on demographics and HIV-related questions (transmission modes, time of diagnosis, clinical stage, laboratory test) were distributed to clinicians in these provinces. Descriptive and bivariate analyses were performed on the completed surveys. RESULTS: Survey results of 650 children [405 males and 245 females; average age: (7.9 +/- 3.2) years] were eligible for analysis. The interval between possible transmission and diagnosis was (7.1 +/- 3.2) years. The location distribution was as follows: 570 cases (87.7%) in Henan Province, 23 cases (3.5%) in Guangxi Province, 21 cases (3.2%) in Yunnan Province, 19 cases (2.9%) in Hubei Province, 10 cases (1.5%) in Anhui Province, and 7 cases (1.1%) in Shanxi Province. Transmission routes included mother-to-child transmission (75.1%), blood transfusion/ plasma donation (15.7 %), and injecting drug use (IDU, 0.5%). Former plasma donation (FPD) was the main transmission route in some provinces (Henan, Shanxi, Hubei, and Anhui), while IDU was the main transmission route in other provinces (Guangxi and Yunnan). The average age in the FPD provinces was significantly higher than that in IDU provinces [(8.1 +/- 3.2) vs. (5.4 +/- 2.2) years, P <0.001]. Among 178 patients in all six provinces who required treatment (on the basis of CD4 count or WHO staging), 133 (74.7%) did not receive treatment and 45 (25.3%) received antiretroviral therapy. CONCLUSION: Mother-to-child transmission is the main transmission mode in pediatric patients. Efforts should be made to strengthen the diagnosis and treatment of pediatric HIV/AIDS patients.

Child↗
PubMed2005

[Experimental infection of mice with Blastocystis hominis].

OBJECTIVE: To seek a better pathway and proper number of parasites for Blastocystis hominis (B.h) infection in normal and immunocompromised ICR mice. METHODS: (1) 10(4), 10(5) and 10(6) B.h, cultured in RPMI 1640 medium from 3 generations were used to infect mice through oral and rectum; (2) 10(6) B.h were used to infect immunocompromised mice through rectum. The reproduction of B.h in gastrointestinal tract and the pathologic changes in the tissues were observed. RESULTS: Mice were infected by B.h through either oral or rectum. The infected immunocompromised mice showed slow locomotion, depressed, lethargy, and descended body weight. Some infected mice discharged mucus feces, a few of them died during the experiment. Parasites were found in the whole gastrointestinal tract. Severe edema, hyperemia and congestion were observed in the tissues of jejunum, ileum, cecum and colon. The epithelia of small intestine and colonic mucous membrane showed exfoliation, inflammatory cell infiltration in submucosa, and structural changes in glands. CONCLUSION: Mice were more susceptible to Blastocystis hominis infection through rectum than orally. The parasites can be found in the whole gastrointestinal tract of mice, and can breed rapidly and cause significant pathological change in the gastrointestinal mucosa in immunocompromised mice.

Animals↗
PubMed2005

Oligomeric cholates: amphiphilic foldamers with nanometer-sized hydrophilic cavities.

The hydroxyl at the C-3 of cholic acid was converted to an amino group, and the resulting amino-functionalized cholic acid was used as a monomer to prepare amide-linked oligomeric cholates. These cholate oligomers fold into helical structures with nanometer-sized hydrophilic internal cavities in solvent mixtures consisting of mostly nonpolar solvents such as carbon tetrachloride or ethyl acetate/hexane and 2-5% of a polar solvent such as methanol or DMSO. The conformations of the foldamers were studied by UV, fluorescence, fluorescence quenching, and fluorescence resonance energy transfer. The nature of the polar/nonpolar solvents and their miscibility strongly influenced the folding reaction. Folding was cooperative, as evidenced by the sigmoidal curves in solvent denaturation experiments. The folded conformers became more stable with an increase in the chain length. The folding/unfolding equilibrium was highly sensitive toward the amount of polar solvent. One percent variation in the solvent composition could change the folding free energies by 0.5-1.4 kcal/mol.

Amides↗
PubMed2005

Density functionals for inorganometallic and organometallic chemistry.

We present a database of 21 bond dissociation energies for breaking metal-ligand bonds. The molecules in the metal-ligand bond energy database are AgH, CoH, CoO+, CoOH+, CrCH3+, CuOH2+, FeH, Fe(CO)5, FeO, FeS, LiCl, LiO, MgO, MnCH3NiCH2+, Ni(CO)4, RhC, VCO+, VO, and VS. We have also created databases of metal-ligand bond lengths and atomic ionization potentials. The molecules used for bond lengths are AgH, BeO, CoH, CoO+, FeH, FeO, FeS, LiCl, LiO, MgO, RhC, VO, and VS and the ionization potentials are for the following atoms: C, Co, Cr, Cu, Ni, O, and V. The data were chosen based on their diversity and expected reliability, and they are used along with three previously developed databases (transition metal dimer bond energies and bond lengths and main-group molecular atomization energies) for assessing the accuracy of several kinds of density functionals. In particular, we report tests for 42 previously defined functionals: 2 local spin density approximation (LSDA) functionals, 14 generalized gradient approximation (GGA) methods, 13 hybrid GGA methods, 7 meta GGA methods, and 8 hybrid meta GGA methods. In addition to these functionals, we also examine the effectiveness of scaling the correlation energy by testing 13 functionals with scaled or no gradient-corrected correlation energy, and we find that functionals of this kind are more accurate for metal-metal and metal-ligand bonds than any of the functionals already in the literature. We also present a readjusted GGA and a hybrid GGA with parameters adjusted for metals. When we consider these 57 functionals for metal-ligand and metal-metal bond energies simultaneously with main-group atomization energies, atomic ionization potentials, and bond lengths we find that the most accurate functional is G96LYP, followed closely by MPWLYP1M (new in this article), XLYP, BLYP, and MOHLYP (also new in this article). Four of these five functionals have no Hartree-Fock exchange, and the other has only 5%. As a byproduct of this work we introduce a convenient diagnostic, called the B1 diagnostic, for ascertaining the multireference character in a bond.

Journal Article↗
PubMed2005

[Prevalence of antiepithelial cell antibody in systemic vasculitis and identification of the target antigen thereof].

OBJECTIVE: To investigate the prevalence of antiepithelial cell antibody (AECA) in systemic vasculitis (SV) and the target antigen thereof. METHOD: Sera of 113 patients with SV of different kinds, 46 patients with Behcet's disease, 23 patients with Takayasu arteritis, 19 patients with Wegener's granulomatosis, 8 patients with polyarteritis nodosa, 7 patients with microscopic polyangiitis, and 10 patients with Churg-Strauss syndrome were collected to detect the protein expression of AECA by Western blotting, with the protein of the endothelial cells of the line EA. hy926 line as substrate. Two-dimensional electrophoresis combined with immunoblotting, liquid chromatography-electrospray ionization mass spectrography was used to detect the target antigens related to vasculitis. Sera of 57 patients with systemic lupus erythematosus (SLE), 25 patients with rheumatoid arthritis (RA), and 20 healthy persons were collected as controls. RESULTS: The AECA-positive rate of the SV patients was 69.0%, not significantly different from that of the SLE patients (66.7%), but significantly higher than those of the RA patients (6.7%, P < 0.01) and healthy persons (0, P < 0.01). The AECA from the SV patients reacted with the endothelial cell (EC) antigens with the molecular size of 26 to 125 kDa, and the AECA from the SLE patients reacted with the EC antigens with the molecular size of 15 to 97 kDa. The EC antigens with the molecular size of 47 kDa was commonly found in the sera of the AECA-positive SV patients and SLE patients, however, was not found in the RA, and polymyositis-dermatomyositis patients. The EC protein reacted by 47 kDa protein was identified by proteomic techniques as alpha-enolase. CONCLUSION: A group of heterogeneous antibodies, AECA can be found frequently in patients with SV and SLA. AECA reacts against a common EC antigen, alpha-enolase.

Adolescent↗