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Yan Gao

Publications and source records attributed to Yan Gao.

At least 73 records · Page 4Linked to original sources
PubMed2005

[MGB probes detect Streptococcus mutans and Streptococcus sobrinus in real time].

OBJECTIVE: To detect and distinguish Streptococcus mutans (S. mutans) and Streptococcus sobrinus (S. sobrinus) quickly in epidemiology and investigate the distribution of S. mutans in the oral of children with rampant caries. METHODS: Designed minor groove binder (MGB) probes according to the gtf gene of S. mutans and S. sobrinus. Detected 9 reference strains of Streptococcus mutans group by MGB probes in real time and after cultivation. Evaluated the results of these two methods. 92 dental plaques from pre-school children with rampant caries were detected in real time with MGB probes. RESULTS: The primers could amplify the target sequences specificity and distinguished S. mutans and S. sobrinus from each other using MGB probes. Though the fluorescence occurred earlier in S. mutans than in S. sobrinus, they had the same results in nature. In 92 children with rampant caries, the detective ratio of S. mutans was 96.7% and that of S. sobrinus was 32.6%. All the samples which could detect S. sobrinus were positive for S. mutans. CONCLUSION: The primers and probe designed from gtf genes of S. mutans and S. sobrinus can amplify the target sequence and distinguish them from each other in real time.

Child↗
PubMed2005

[The epitope analysis of beta Netrin and preparation and characterization of its antibodies].

AIM: To prepare and characterize anti-human beta-Netrin antibodies. METHODS: B cell dominant epitopes of human beta-Netrin C-terminal 114 amino acid sequences were predicated by the GoldKey software. One of the epitopes was synthesized and coupled with bovine serum album (BSA) by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). The BALB/c mice were immunized with the coupled protein. The splenocytes of immunized mice were fused with Sp2/0 cells by routine method and the hybridomas were selected in HAT medium. The hybridoma cells secreting specific antibody were detected by ELISA and cloned by limiting dilution. The titer specificity, and Ig subclass of anti-beta-Netrin mAbs were characterized by ELISA, Western blot and immunocytochemical staining. In addition, New Zealand rabbits were immunized with the coupled protein to prepare polyclonal antibody against beta-Netrin. The specificity of the antiserum was verified by Western blot. RESULTS: A 16-mer peptide NH2-FRGKRTLYPES-WTDRG-COOH was the dominant epitope of the B cells. Synthesized peptide coupled with BSA was used as the immunogen to immunize BALB/c mice. Three hybridoma cell lines that stably secrete specific mAbs were obtained. The result of immunocytochemical staining showed that prepared mAb specifically recognize the antigen in the neuronal cells. The polyclonal antibody against beta-Netrin had high specificity. Western blot analysis showed that the antiserum bind with the prokaryotically expressed beta-Netrin specifically. CONCLUSION: Using the synthesized peptides as hapten, we have prepared epitope-specific mAbs and pAb against beta-Netrin successfully.

Amino Acid Sequence↗
PubMed2005

[Studies on chemical constituents from Salvia roborowskii Maxim].

OBJECTIVE: To study the chemical constituents from Salvia roborowskii Maxim. METHODS: Chromatography and spectroscopic analysis were employed to isolate and elucidate the chemical constituents in the plant. RESULTS: Three compounds were isolated and elucidated as 1 beta-hydroxy-lupeol (I), quercetin-3-O-beta-D-glucoside (II), rutin (III). CONCLUSION: I - III were isolated from this plant for the first time.

Chromatography, Thin Layer↗
PubMed2005

[Combined bio-process for treatment of municipal wastewater containing Cu2+].

A combined bioprocess consisting of biosorption section with P. putida 5-x cell as biosorbent followed by a SBR is developed to treat Cu2+ containing municipal wastewater. The optimal preparing technique of P. putida 5-x cell as biosorbent is studied. Under the optimal condition, adsorption capacity of the P. putida 5-x cell to Cu2+ reached 87.3 mg x g(-1). The performance of the combined bioprocess for treating Cu2+ containing wastewater is assessed. The experimental results indicate that after treatment by the biosorption section, the Cu2+ concentration in wastewater reduced to the level that did not inhibit COD removal efficiency of subsequent SBR activated sludge process, although it still affectes the COD adsorption capacity of activated sludge. In terms of COD removal, the biosorption section is efficient for reducing Cu2+ concentration to provide biodegradable wastewater for subsequent SBR activated sludge process.

Adsorption↗
PubMed2005

[Histopathological features of oral pemphigus vegetans].

OBJECTIVE: To investigate the clinicopathological features of oral pemphigus vegetans. METHODS: Seven cases of pemphigus vegetans involving oral mucosa were included in this study. The paraffin sections were analyzed by routine light microscope. RESULTS: There were 5 females and 2 males in this group, with an average age of 52.7 years. The course of diseases was from 3 months to 10 years. Oral manifestations included verrucous or papilliform hyperplasia of oral mucosa, with extensive edema and exudation. Similar skin lesions were found in 5 patients. Under the microscope, pemphigus vegetans showed epithelial thickening with prolonged rete pegs, intraepithelial clefts in suprabasal cells. Eosinophilic microabscesses was often seen within the epithelium. Other microscopic changes were intraepithelial edema and eosinophils infiltration, chronic inflammatory cells infiltration in the lamina propria. CONCLUSION: The microscopic features pemphigus vegetans described in this study are of valuable for pathological diagnosis of oral pemphigus vegetans.

Adult↗
PubMed2005

[Clinical and pathological analysis of oral manifestations of 40 patients with secondary syphilis].

OBJECTIVE: To analyze the clinical and pathological features of 40 patients with secondary syphilis. METHODS: A total of 40 cases of secondary syphilis confirmed by serology were collected during 1994-2004 and were first diagnosed on presentation with oral lesions. RESULTS: The white patch in oral mucosa was found in 32 cases with painless or slight pain in most cases. The most common site of the lesion was the tongue. The histological examination on eight cases was initially misdiagnosed as oral candidosis or lichen planus, but confirmed as syphilis after serology revealed nonspecific inflammation with intraepithelial microabscess and dense perivascular infiltration of lymphocytes and plasma cells in connective tissue. The symptoms showed dramatic improvement in 16 cases after benzathine penicillin treatment. CONCLUSIONS: The oral manifestations of syphilis have specific clinical and pathological feature and attention should be paid to the suspicious oral lesions when patients are first presented in a dental office.

Adult↗
PubMed2005

Evaluation of international classification criteria (2002) for primary Sjögren's syndrome in Chinese patients.

OBJECTIVE: To evaluate the sensitivity and specificity of international classification criteria (2002) for primary Sjögren's syndrome (pSS) and the role of lower lip biopsy in diagnosis of pSS in Chinese patients. METHODS: Patients who were diagnosed by the experts/rheumatologists as pSS during 1990-2002 from the Department of Rheumatology, Peking Union Medical College Hospital were retrospectively collected as experimental group. Patients who were diagnosed as non-pSS connective tissue diseases or non-connective tissue diseases served as control group. Those with a history of head-neck radiation, hepatitis C virus infection, AIDS, lymphoma, sarcoidosis, graft versus host disease (GVHD), and anti-acetylcholine drug use were exempted. Both groups were required to complete questionnaires about symptoms such as dry eyes and dry mouth, and complete the objective tests of keratoconjunctivitis and xerostomia including Schirmer test, corneal staining, unstimulated salivary flow, sialography, lower lip biopsy, and antinuclear antibodies (including anti-SSA/SSB antibodies) test. RESULTS: A total of 330 pSS patients were included in experimental group and 185 non-pSS patients in control group. The mean age of both groups matched (47.8 +/- 10.9 years vs. 46.2 +/- 13.6 years, P > 0.05). The sensitivities of the criteria in pSS patients with lower lip biopsy and in pSS patients without lower lip biopsy were 89.2% and 87.2%, respectively; the overall sensitivity was 88.5%. The specificity was 97.3%. A total of 11.3% pSS patients with negative anti-SSA/SSB anti- bodies were diagnosed as pSS by lower lip biopsy. CONCLUSION: The international classification criteria (2002) for pSS is feasible in Chinese patients. It has high sensitivity and specificity, and may serve as diagnosis criteria in routine clinical practice.

Adolescent↗
PubMed2005

[Roles of Wnt-1, beta-catenin and adenomatous polyposis coli in the differentiation and proliferation of oral squamous cell carcinoma].

OBJECTIVE: To investigate the expressions of Wnt-1, beta-catenin and adenomatous polyposis coli (APC) in oral squamous cell carcinoma (OSCC). METHODS: Surgical specimens from 66 OSCC patients were examined for Wnt-1, beta-catenin, APC and MIB-1 expressions by immunohistochemical staining. RESULTS: Among all the 37 cases of well differentiated OSCCs, there were 30, 25 and 31 cases of high expressions of Wnt-1, APC and beta-catenin, respectively, 7, 12 and 6 cases of low expressions. Among all the 29 cases of moderate and poor differentiated OSCCs, there were 6, 9 and 11 cases of high expressions of Wnt-1, APC and beta-catenin respectively, 23, 20 and 18 cases of low expressions. Among all the 66 cases of OSCCs, there were 32 cases of high expressions of MIB-1 and 34 cases of low expressions. Expressions of Wnt-1, beta-catenin and APC showed significant difference in different differentiation of OSCC. CONCLUSIONS: Wnt-1, beta-catenin and APC expressions were related to the differentiation of OSCC.

Adenomatous Polyposis Coli Protein↗
PubMed2005

[Clinical value of ultrasound guided transperineal prostate biopsy in detecting prostate cancer].

OBJECTIVE: To report our experience of ultrasound guided transperineal 6-core prostate biopsy (UG6CPB) in the diagnosis of prostate cancer (PCa). METHODS: In a prospective study, we performed UG6CPB in 104 suspected PCa patients with tPSA more than 4 microg/L and analysed the positive rate and complications of the diagnostic approach. RESULTS: PCa was detected in 24 of the 104 patients (23%), with low grade Gleason 2 to 4 in 3 cases (12.5%), intermediate grade Gleason 5 to 7 in 15 (62.5%) and high grade Gleason 8 to 10 in the remaining 6 (25%). Complications included temporary hematuria in 5 patients (4.8%), mild postbiopsy perineal discomfort in 5 (4.8%) and fever in 4 (3.8%). TPSA > or =10 microg/L, fPSA > or = 2 microg/L, fPSA/tPSA < 0.16, PSAD > or = 0.2 and prostate volume < 40 ml were the significant influencing factors of biopsy positive rate (P < 0.05). CONCLUSION: UG6CPB is an exact and a safe way of detecting PCa.

Biopsy, Needle↗
PubMed2005

Regulatory effect of e2, IL-6 and IL-8 on the growth of epithelial ovarian cancer cells.

To determine the regulatory effects of estrogen and cytokine IL-6 and IL-8 on the growth of epithelial ovarian cancer (OVCA), we first examined the status of estrogen receptors (ERalpha and ERbeta ), IL-6 receptor (IL-6Ralpha and gp130), and IL-8 receptor (IL-8RA and IL-8RB) on five epithelial OVCA cell lines by semiquantitative RT-PCR and Western blot analysis. Results showed that the expressions of these receptors were variable on the five cells. Those OVCA cells expressing the receptors were selected to study related molecular mechanism. MTT assay was performed to observe the effects of 17beta-estradiol (E2), IL-6 and IL-8 on cell proliferation. We discovered that E2 markedly promoted the proliferation of CAOV-3 and OVCAR-3 cell in a time- and dose-dependent manner. Tamoxifen (Txf), an ER inhibitor, completely blocked the proliferation of the E2-induced cells, and IL-6- or/and IL-8-neutralizing antibody only showed partially blocking activity. IL-6 and IL-8 were able to significantly stimulate CAOV-3 and OVCAR-3 cell proliferation in a time- and dose-dependent manner, which had a potential synergistic effect on CAOV-3 cells but not on OVCAR-3 cells. The cell proliferation induced by these two cytokines was abolished completely by their specific neutralizing antibodies, partially by Txf, but not by unrelated goat IgG. Taken together, our results suggested that estrogen, IL-6 and IL-8 could modulate OVCA growth by forming a reciprocal cascade with amplifying effect.

Cell Line, Tumor↗
PubMed2005

[Preliminary study on the alpha-glucosidase inhibitor from Glycyrrhiza uralensis Fisch].

OBJECTIVE: To extract and isolate alpha-glucosidase inhibitor from Glycyrrhiza uralensis Fisch. METHODS: The aqueous extract of Glycyrrhiza uralensis Fisch. was extracted by petroleum, ethyl acetate and n-butanol. In addition, the inhibitory activity against alpha-glucosidase of every fraction was determined and the inhibitory kinetics of ethyl acetate fraction was investigated. RESULTS: The inhibitory activities of four fractions were 68.93%, 83.2%, 32.17% and 10.79% respectively. Compared with the aqueous extract (69.77%), the inhibitory activity of ethyl acetate fraction was higher. Ethyl acetate fraction was shown to be a fast-binding, dose-dependent and competitive model with a Ki value of 34 microg/ml. CONCLUSION: It is hoped to obtain good alpha-glucosidase inhibitors by separating ethyl acetate fraction of aqueous extract of Glycyrrhiza uralensis Fisch further.

Acetates↗
PubMed2004

Machinable long PVP-stabilized silver nanowires.

PVP-capped silver nanowires with a diameter range from 150 to 200 nm and a length range from 50 to 100 microm have been synthesized in large quantity by using a soft-template liquid-phase method. The so-obtained longer and thicker metallic nanowires exhibit fivefold-twinned structures bound by five [1 0 0] wall-planes and two spearlike ends around five [1 1 1] facets. X-ray photoelectron spectroscopy (XPS) investigations show that a strong interaction exists between the carboxyl oxygen atom (C=O) of PVP and the Ag core interface. The PVP-capped Ag nanowires can either self-assemble into ordered raft structures or form a complicated network, depending on the dispersive solvent employed. In addition, the Ag nanowires can also be specifically bent into various angles, demonstrating their excellent mechanical stability.

Journal Article↗
PubMed2004

Association of interleukin-12 p40 gene 3'-untranslated region polymorphism and outcome of HCV infection.

AIM: To investigate the effect of interleukin-12 p40 gene (IL12B) 3'-untranslated region polymorphism on the outcome of HCV infection. METHODS: A total of 133 patients who had been infected with HCV for 12-25 (18.2+/-3.8) years, were enrolled in this study. Liver biochemical tests were performed with an automated analyzer and HCV RNA was detected by fluorogenic quantitative polymerase chain reaction. B-mode ultrasound was used for liver examination. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used for the detection of IL12B (1188A/C) polymorphism. RESULTS: Self-limited infection was associated with AC genotype (OR = 3.48; P = 0.001) and persistent infection was associated with AA genotype (OR = 0.34; P = 0.014) at site 1188 of IL12B. In patients with persistent HCV infection, no significant differences were found regarding the age, gender, duration of infection and biochemical characteristics (P>0.05). According to B-mode ultrasound imaging and clinical diagnosis, patients with persistent infection were divided into groups based on the severity of infection. No significant differences were found in the frequency of IL-12 genotype (1188A/C) between different groups (P>0.05). CONCLUSION: The polymorphism of IL12B (1188A/C) appears to have some influence on the outcome of HCV infection.

3' Untranslated Regions↗
PubMed2004

[Nine-year follow-up of hepatitis C virus infection in a rural area of Hebei province, China].

OBJECTIVE: To investigate natural history of hepatitis C virus infection and related factors among plasma donors in China. METHODS: 172 plasma donors in a rural area of Hebei province had been diagnosed as HCV infection in 1993. No antiviral treatment was applied to them during the period of infection. In the present study, we investigated the outcome of HCV infection nine years later and related factors affecting the outcome. In fact, only 142 cases were followed up in the investigation. The mean age of 142 cases of blood donors was 46 +/- 9 and the mean age of infection was 37 +/- 9 years old. RESULTS: After nine-year follow-up, 1.2% died of end-stage liver disease. 130 (91.6%) of 142 cases under investigation were still positive for HCV RNA or anti-HCV in their blood and 12 cases (8.4%) were negative for both HCV RNA and anti-HCV. 3.1% developed liver cirrhosis among the patients with persistent infection. The mean level of ALT, AST, GGT among HCV RNA positive cases were significantly higher than that of HCV RNA negative cases (P < 0.001). The abnormal rates of ALT and/or AST in male patients were significantly higher than those of female patients (P = 0.005). The rate of progression to liver cirrhosis from chronic hepatitis C virus was significantly higher in patients co-infected with HCV/HBV than that of the cases of single HCV infection. CONCLUSION: Higher chronic rate was observed in this research. Superinfection of HBV/HCV may have worse clinical outcomes.

Adult↗
PubMed2004

G-protein-coupled receptor-mediated activation of rap GTPases: characterization of a novel Galphai regulated pathway.

Ras proteins mediate the proliferative effects of G-protein-coupled receptors (GPCRs), but the role of Rap proteins in GPCR signaling is unclear. We have developed a novel cellular proliferation assay for examining signal transduction to Rap utilizing Ras-rap chimeras that respond selectively to Rap-specific exchange factors, but which stimulate cellular proliferation through Ras effectors. Both the D1 dopamine receptor (Gs-coupled) and the 5HT1E serotonin receptor (Gi-coupled) mediated cellular proliferation in a Ras/rap chimera-dependent manner. Responses to both receptors were PKA-independent. Both receptors activated Ras/rap and full-length Rap as measured by activation-specific probes. Pertussis toxin blocked Ras/rap-dependent responses to 5HT1E but not D1. Ras/rap-dependent responses to both receptors were insensitive to beta-gamma scavengers. Responses to 5HT1E, but not D1, were sensitive to inhibition by a dominant-negative C3G fragment, by the Src-like kinase inhibitors PP1 and PP2, and by a dominant-negative mutant of Src. Very similar data were obtained for two other Gi-coupled receptors, the D2 dopamine receptor and the alpha2C adrenergic receptor. A constitutively active mutant of Galphai2 also mediated Ras/rap-dependent responses. These data indicate that GPCRs coupled to pertussis-toxin-sensitive G-proteins activate Rap through a Galpha subunit, C3G, and Src-dependent pathway.

Animals↗
PubMed2004

Use of pyrosequencing to detect clinically relevant polymorphisms of genes in basal cell carcinoma.

BACKGROUND: Pyrosequencing is a new method to detect single nucleotide polymorphisms (SNPs). Basal cell carcinoma (BCC) is one of the most common neoplasms in the world, and its incidence has been increasing worldwide in recent years. BCC is caused by an interplay between genetic and environment factors. METHODS: Pyrosequencing and restrict fragment length polymorphism (RFLP) were used in the study. We conducted a case-control association study in BCC cases and controls from Sweden. For SNPs in IL-6, IL-10 and IL-1beta, 241 cases were at the age of 27-70 years (mean 50 years) and 260 healthy controls were 26-71 years (mean 48 years), 241 cases were 27-70 years (mean 50 years) and 574 healthy controls were 22-74 years (mean 52 years) for cyclin D1 G870A, 197 cases were 29-69 years (mean 47 years) and 574 healthy controls were 22-74 years (mean 52 years) for MTHFR C677T and A1298C. Nine SNPs for IL-6-174G/C, -634G/C and -597G/A; IL-10-1082G/A and -592C/A; IL-1beta-511C/T; cyclin D1 G870A; MTHFR C677T and A1298C were analyzed. RESULTS: Most genotype distributions were in accordance with Hardy-Weinberg equilibrium (HWE), except IL-10-1082G/A, which had a significantly deviation from HWE in BCC cases (P<0.05). Linkage disequilibrium was observed between the -174 and -597 alleles in the IL-6 gene in the studied populations. The differences for cyclin D1 G870A and methylenetetrahydrofolate reductase (MTHFR) C677T were found between BCC cases group and control group (P<0.05, OR=1.34, 95% CI, 1.00-1.74; P<0.05, OR=1.67, 95% CI, 1.13-2.47, respectively). CONCLUSIONS: Cyclin D1 G870A and MTHFR C677T were associated with BC cases from Sweden, the other SNPs studied here were not associated with BCC, but chance cannot be excluded.

Adult↗
PubMed2004

Activated Fps/Fes tyrosine kinase regulates erythroid differentiation and survival.

OBJECTIVE: A substantial body of evidence implicates the cytoplasmic protein tyrosine kinase Fps/Fes in regulation of myeloid differentiation and survival. In this study we wished to determine if Fps/Fes also plays a role in the regulation of erythropoiesis. METHODS: Mice tissue-specifically expressing a "gain-of-function" mutant fps/fes transgene (fps(MF)) encoding an activated variant of Fps/Fes (MFps), were used to explore the in vivo biological role of Fps/Fes. Erythropoiesis in these mice was assessed by hematological analysis, lineage marker analysis, bone-marrow colony assays, and biochemical approaches. RESULTS: fps(MF) mice displayed reductions in peripheral red cell counts. However, there was an accumulation of immature erythroid precursors, which displayed increased survival. Fps/Fes and the related Fer kinase were both detected in early erythroid progenitors/blasts and in mature red cells. Fps/Fes was also activated in response to erythropoietin (EPO) and stem cell factor (SCF), two critical factors in erythroid development. In addition, increased Stat5A/B activation and reduced Erk1/2 phosphorylation was observed in fps(MF) primary erythroid cells in response to EPO or SCF, respectively. CONCLUSIONS: These data support a role for Fps/Fes in regulating the survival and differentiation of erythroid cells through modulation of Stat5A/B and Erk kinase pathways induced by EPO and SCF. The increased numbers and survival of erythroid progenitors from fps(MF) mice, and their differential responsiveness to SCF and EPO, implicates Fps/Fes in the commitment of multilineage progenitors to the erythroid lineage. The anemic phenotype in fps(MF) mice suggests that downregulation of Fps/Fes activity might be required for terminal erythroid differentiation.

Anemia↗