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Biomedical subjects

Yan Sun

Publications and source records attributed to Yan Sun.

At least 109 records · Page 6Linked to original sources
PubMed2005

[Relationship between the R219K polymorphism of ATP-binding cassette transporter 1 gene and coronary heart disease].

To study the distribution of R219K polymorphism in ATP-Binding Cassette Transporter 1 (ABCA1) gene in Chinese Han population and the association of this polymorphism with coronary heart disease (CHD) . Genotypes were determined by PCR-RFLP approach in 417 unrelated healthy controls and 396 CHD patients. The frequencies of K allele and KK genotype for controls (0.465, 0.228) were significantly higher than those (0.381, 0.162) for patients (P<0.05). When the patients were divided into two subgroups by onset-age, the frequencies of K allele and KK genotype for early-onset patients (0.34, 0.111) were lower than those (0.419, 0.205) for late-onset patients and those for controls (P<0.05) , while there were no such differences between late-onset patients and controls. Patients with RR genotype had a higher plasma concentration of triglycerides (TG) when compared with that of KK genotype (P<0.05) . No significant differences of plasma high-density lipoprotein cholesterol (HDL-C) level were observed among patients with different genotypes. These data suggest that the R219K polymorphism in ABCA1 gene is correlated with CHD, and the ABCA1 gene KK genotype may has a function against atherosclerosis without detectable change of plasma HDL-C level in Chinese Han population.

ATP Binding Cassette Transporter 1↗
PubMed2005

[Recombinant adenovirus-p53 gene therapy combined with radiotherapy for head and neck squamous-cell carcinoma].

OBJECTIVE: To evaluate the efficacy and safety of recombinant adenovirus-p53 gene (Gendicine) therapy combined with radiotherapy for head and neck squamous-cell carcinoma (HNSCC). METHODS: From Oct. 2001 to May 2003, a randomized controlled clinical trial on Gendicine combined with radiation in 36 patients (gene therapy + radiotherapy, GTRT) vs. radiotherapy alone in 33 patients (RT) with HNSCC was completed. In the GTRT group, Gendicine 1 x 10(12) VP (virus particle) was injected intratumorally once a week for eight weeks, and concurrently followed by irradiation. For both groups, the conventional fractionation 2 Gy/f, five fractions a week to a total dose of 70 Gy, was given to either primary tumor or neck lymph nodes. Tumor response was assessed by CT image at 40 Gy, 70 Gy, 2 months after treatment to evaluate the response rate of CR, PR, SD and PD. RESULTS: Wild-type p53 gene significantly enhanced radiotherapeutic effectiveness in patients with HNSCC (P < 0.05). The CR rate of tumors treated by GTRT was increased by nearly 2.31 times more than that of tumors treated by RT alone. No dose-limiting toxicity and adverse events were noted, except transient fever after Gendicine administration. CONCLUSION: Intratumoral injection of Gendicine to HNSCC patients is safe and effective. The apparent improved results of combined therapy with Gendicine and radiation suggest that p53 gene therapy has promising therapeutic potential in cancer treatment.

Adenoviridae↗
PubMed2005

[A Chinese autosomal dominant polycystic kidney disease family probably related to PKD2 gene].

OBJECTIVE: To study the genetic heterogeneity of autosomal dominant polycystic kidney disease (ADPKD) in Chinese. METHODS: Using polymerase chain reaction (PCR) and non-denatured polyacrylamide gel electrophoresis, the authors analyzed eight microsatellite markers closely linked to PKD1 or PKD2 genes respectively in a Chinese ADPKD family. RESULTS: Seven informative markers were found in this family, including KG8, SM6, CW4 and CW2 which are tightly linked to PKD1, and D4S1563, D4S414 and D4S423 which are linked to PKD2. After the process of genotyping, the haplotypes were estimated with Cyrillic 2.0, and the linkage-based analysis suggested that the disease is not linked to PKD1 other than PKD2. CONCLUSION: In China this non-PKD1 family is the second one, but it is the first reported PKD2 family showing the genetic heterogeneity of ADPKD in Chinese. In the family the affected mother transmits the disease and the affected members' phenotypes are eterogeneous. In addition, the existing "anticipation" and the presence of the disease in a child of this family suggest that non-PKD1 linked families may have early-onset of the disease in child.

Adult↗
PubMed2005

[Cell differentiation during carcinogenesis of cervical epithelia].

BACKGROUND & OBJECTIVE: The disturbance of cell differentiation is an important characteristic of tumor, but, up to date, the researches on this aspect are not as deep as those on cell proliferation of tumor. This study was to detect the alterations of cell differentiation and relative regulating factors during the carcinogenesis of cervical epithelia. METHODS: The protein expression of keratin (KT) 10, 14, 19 and beta1-integrin and beta-catenin in 20 specimens of normal squamous epithelium (NSE), 19 specimens of dysplasia squamous epithelial hyperplasia (DSEH), 39 specimens of squamous carcinoma in situ (SCIS), and 20 specimens of invasive squamous epithelial carcinoma (ISEC) were detected by inmmunohistochemistry; the mRNA expression of of beta1-integrin and beta-catenin were detected by in situ hybridization. RESULTS: The strong positive rates of KT10 in NSE, DSEH, SCIS, and ISEC were 85.0%, 52.6%, 18.0% and 0, respectively, with a descending trend; it was significantly lower in SCIS and ISEC than in NSE and DSEH (Chi(2)=11.28, P<0.05; Chi(2)=8.53, P<0.05). The expression of KT14 and KT19 showed a heterogeneity in SCIS and ISEC: the proteins were negative in some cases, but overexpressed in other cases with positive cells moved upwards from the basal layer; positive cells scattered at the full epithelial layer of SCIS. The expression of beta1-integrin also showed a descending trend in NSE, DSEH, SCIS, and ISEC. The positive rate of beta1-integrin was significantly lower in ISEC than in NSE and DSEH (Chi(2)=7.62, P <0.05; value of exact probability=0.014, P < 0.05); the mRNA expression of beta1-integrin showed the same trend as its protein expression in the samples although the difference were not significant. The protein and mRNA expression of beta-catenin was located in nuclei or cytoplasm of SCIS and ISEC; increased positive cells moved upwards from the basal layer. CONCLUSIONS: Restraint of terminal differentiation of epithelial cells may relate to the abnormal expression of beta1-integrin and the dysfunction of Wnt signaling pathway on regulating cell differentiation during the carcinogenesis of cervical epithelia. The expression of KT10 and beta1-integrin in SCIS is not obviously different from that in ISEC.

Carcinoma in Situ↗
PubMed2005

[Effects of soil compactness stress on root activity and leaf photosynthesis of cucumber].

Responses of root activity and leaf photosynthesis to soil compactness stress were studied in cucumber plants grown in pots. Soil compaction was expressed by soil bulk density. There were three compactness treatments with soil bulk densities, 1.2, 1.4 and 1.6 g/cm(3). The results showed that when the soil compactness increased, the dry weight and activity of roots reduced (Fig. 1); the relative electrical conductivity and malondialdehyde (MDA) content of cucumber leaf (Fig. 2) increased; the soluble protein content decreased (Fig. 3); the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) increased (Fig. 4); net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (E) and specific leaf weight (SLW) decreased, but intercellular CO(2) concentration (Ci) increased (Fig. 5). These results mean that high soil compaction brings stress to cucumber plants.

Catalase↗
PubMed2005

[The study of phonatory function in myasthenia gravis patients].

OBJECTIVE: To investigate the phonatory function in myasthenia gravis patients and the role of acoustic analysis technique in the diagnosis and the assessment of therapeutic effect on treatment of myasthenia gravis. METHOD: Eighty-three myasthenia gravis patients diagnosed definitely in neurology were divided into two groups, ocular group and generalized group. Each group included male group and female group. Acoustic measures were carried out before and after neostigmine test and treatment. Forty healthy subjects including twenty male and twenty female served as control groups. The basic parameters of the voice using computed voice analysis included F0, shimmer, jitter and NNE. Independent-Samples T Test and Paired-Samples T Test were used. RESULT: The value of F0 and NNE increased in generalized group. The changes of F0 and NNE in generalized group were found to be statistically significant (P < 0.01, 0.05). Neostigmine resulted in an improvement in the parameters of F0 and NNE, the same condition happened after the treatment (P < 0.01). CONCLUSION: Phonatory function of generalized myasthenia gravis patients is abnormal. F0 and NNE increase in generalized myasthenia gravis patients and decrease after the treatment or the intake of neostigmine. Acoustic analysis is a useful method in the diagnosis and assessment of generalized myasthenia gravis patients.

Adolescent↗
PubMed2005

[Application of partial laryngectomy in laryngeal cancer treatment and reconstruction with epiglottic flap and bi-pedicle muscle flap].

OBJECTIVE: To explore and evaluate the surgical method of partial laryngectomy and the laryngeal defects were reconstructed. METHOD: Two hundreds and sixty-five patients with laryngeal cancer were treated by partial laryngectomy and the laryngeal defects were reconstructed by epiglottic flap, bi-pedicle sternohyoid muscle fascia flap and epiglottic flap plus bi-pedicle sternohyoid muscle fascia flap from January 1990 to December 2000. There were 256 males and 9 females,ranging in age from 48 to 75 years old. Neck dissection were performed in 79 patients. RESULT: The total cases began to eat between 10 to 15 days after operation. Two hundreds and eighteen cases were decannulated with a decannulation rate of 82.26%. Wound infection occurred in 12 cases and 2 pharyngocutaneous fistula was found. The three and five years survival rates were 74.72% and 70. 88% respectively. CONCLUSION: After partial laryngectomy in laryngeal cancer epiglottic flap and bi-pedicle muscle fascia flap were performed reconstruction of laryngeal function in a single-stage. These procedures which were relative simplicity, expediency, small injury and high rate of survival present ideal effects and are worthy to be recommended.

Aged↗
PubMed2005

[A method for DNA template preparation using a single embryo].

We established a simple method for the preparation of DNA template from a single oocyte or early embryo by KOH/DTT-Triton X disintegration. The PCR amplification efficiency of DNA template prepared by this method was compared with that prepared by TE-proteinase K. Single oocyte, 2-cell embryo, 8-cell embryo, morula or blastocyst were separately treated by KOH/DTT-Triton X, then the DNA template was directly used to amplify mitochondrial DNA segment by PCR. The overall PCR success rate of the 3 pairs of primers was 100% (70/70), while the overall PCR success rate of single oocyte treated by TE-proteinase K was 92.9% (65/70). Difference between the two results was significant (P<0.05), and the PCR false positive rates in both groups were 0. The designed KOH/DTT-Triton X disintegrate method was efficient to the preparation of DNA template of a single early embryo. It needed only one cycle of PCR amplification to get clear aimed DNA stripe and the efficiency was high enough to meet the need of early embryonic genetic material detection.

Animals↗
PubMed2005

[Multiplex RT-PCR for the rapid detection of influenza virus types and subtypes].

OBJECTIVE: To establish a sensitive and specific multiplex RT-PCR(MRT-PCR) for the simultaneous detection of influenza virus types and subtypes. METHODS: Primers were designed from highly conserved region of the hemagglutinin(HA) gene of influenza H1N1H3N2 and B virus and MRT-PCR was performed. Additional two pairs of primers were designed to determine the N1 and N2 subtypes of neuramidinase NA of influenza H1N1 and H3N2 virus. RESULTS: The fragments of HA gene of all types of influenza virus were amplified and there was no cross reaction. The sensitivity of detection of influenza H1N1 and H3N2 virus was 0.10 TCID50/50 microliter by the second PCR and that was 0.01 TCID50/50 microliter for influenza B virus. The NA gene of influenza H1N1 and H3N2 virus was also amplified by this method. CONCLUSION: The sensitivity of detection of influenza virus from clinical patients' throat washing specimens by MRT-PCR was higher than that by MDCK cell culture or egg embryo isolation. This method was highly sensitive and timely for detection of influenza virus types and subtypes.

Animals↗
PubMed2005

[Correlation of genetic polymorphisms in nucleotide excision repair system to sensitivity of advanced non-small cell lung cancer patients to platinum-based chemotherapy].

BACKGROUND & OBJECTIVE: DNA repair system plays an important role in tumor sensitivity to platinum-based chemotherapy. This study was to examine the correlations of polymorphisms in nucleotide excision repair system to sensitivity of advanced non-small cell lung cancer (NSCLC) to platinum-based chemotherapy. METHODS: Treatment outcomes of 200 advanced NSCLC patients, treated with platinum-based chemotherapy, were evaluated. XPC-PAT, XPD Lys751Gln (rs1052559), and ERCC1 C8092A (rs1052559) were genotyped by polymerase chain reaction-amplified fragment length polymorphism (PCR-AFLP) or PCR-restrictive fragment length polymorphism (PCR-RFLP) methods in the 200 patients. Unconditional logistic regression model was used to analyze the correlation of genetic polymorphisms to clinical response. RESULTS: The distributions of XPC-PAT genotypes differed significantly between response group (complete response + partial response) and un-response group (stable disease + progressive disease)(P=0.023). The XPC LL genotype carriers had higher response rate than the SS genotype carriers (OR=3.04; 95% CI=1.25-7.41, P= 0.015). The XPD Lys751Gln and ERCC1 C8092A polymorphisms were not found to be associated with platinum-based chemotherapy. However, these 3 genetic polymorphisms in nucleotide excision repair system had interaction in the drug sensitivity (P=0.021). CONCLUSION: The genetic polymorphisms of XPC-PAT, XPD Lys751Gln, and ERCC1 C8092A in nucleotide excision repair system may be associated with sensitivity of NSCLC patients to platinum-based chemotherapy.

Adult↗
PubMed2005

[Expressions and significance of E-cadherin and beta-catenin in synovial sarcoma].

OBJECTIVE: To explore the expression and significance of E-cadherin (E-cad) and beta-catenin (beta-cat) in synovial sarcoma. METHODS: Expression of E-cad and beta-cat in 72 cases of synovial sarcoma were detected by tissue microarray technique and immunohistochemistry. The relationships between E-cad and beta-cat expression and clinicopathological data and survival rate were analyzed. RESULTS: (1) 95.1% of dots on the tissue microarrays were observable morphologically. The background was clear and the contrast was vivid after immunohistochemistry. (2) The expression of E-cad was reduced in 56 patients (77.8%) and that of beta-cat was reduced in 51 patients (70.8%). (3) In patients with synovial sarcoma of monophasic fibrous type, grade III, and in patients with recurrence or metastasis, CK-negative and EMA-negative the rates of reduced expression of E-cad and beta-cat were significantly higher than those with primary sarcoma of biphasic type, grade II, CK-positive and EMA positive (P < 0.05 for all). (4) The survival of synovial sarcoma patients with E-cad and beta-cat expressions preserved was significantly better than those with reduced expressions (P = 0.012, P = 0.047). CONCLUSION: The expression of E-cad and beta-cat is correlated with cell differentiation. Reduced expression of E-cad and beta-cat may indicate a high potential of recurrence or metastasis and poor prognosis. Tissue microarray technique is applicable for retrospective studies of large sample size.

Adult↗
PubMed2004

Novel biporous polymeric stationary phase for high-speed protein chromatography.

A novel rigid biporous bead (BiPB) had been fabricated by double emulsification to prepare a (w/o)/w emulsion and a subsequent polymerization. The polymerization of monomers, glycidyl methacrylate and ethylene glycol dimethacrylate, was initiated with benzoin ethyl ether by ultraviolet irradiation. The BiPB with an average diameter of 42.8 microm was characterized to possess two types of pores, i.e., micropores (20-100nm) and superpores (300-4000nm). Its specific surface area was determined to be 41.9m2/g, about 20% smaller than that of a microporous bead (MiPB) (52.1 m2/g). Flow hydrodynamic experiments showed that the BiPB column had smaller backpressure and plate height than those of the MiPB column at a given flow rate. Derivatized with diethylamine (DEA), the static adsorption capacity of the DEA-BiPB was about 7% smaller than that of the DEA-MiPB for BSA (bovine serum albumin). However, frontal analysis demonstrated that the dynamic binding capacity of the DEA-BiPB column was 1.6-2.4 times higher than that of the DEA-MiPB at high flow rate range of 1200-2400cm/h. Moreover, separation of a model protein mixture (myoglobin and BSA) was conducted at mobile phase velocities up to 3000cm/h to compare the performance of the two stationary phases. All the results indicate that the BiPB contains interconnected flowthrough pores and the BiPB column is promising for high-speed protein chromatography.

Adsorption↗
PubMed2004

COBRA1 inhibits AP-1 transcriptional activity in transfected cells.

Mutations in the breast cancer susceptibility gene (BRCA1) account for a significant proportion of hereditary breast and ovarian cancers. Cofactor of BRCA1 (COBRA1) was isolated as a BRCA1-interacting protein and exhibited a similar chromatin reorganizing activity to that of BRCA1. However, the biological role of COBRA1 remains largely unexplored. Here, we report that ectopic expression of COBRA1 inhibited activator protein 1 (AP-1) transcriptional activity in transfected cells in a dose-dependent manner, whereas reduction of endogenous COBRA1 with a small interfering RNA significantly enhanced AP-1-mediated transcriptional activation. COBRA1 physically interacted with the AP-1 family members, c-Jun and c-Fos, and the middle region of COBRA1 bound to c-Fos. Lack of c-Fos binding site in the COBRA1 completely abolished the COBRA1 inhibition of AP-1 trans-activation. These findings suggest that COBRA1 may directly modulate AP-1 pathway and, therefore, may play important roles in cell proliferation, differentiation, apoptosis, and oncogenesis.

Binding Sites↗
PubMed2004

A liquid chromatographic method for simultaneous determination of amoxicillin sodium and sulbactam sodium in a combination formulation.

An isocratic liquid chromatographic method with UV detection at 210nm is described for simultaneous determination of amoxicillin sodium and sulbactam sodium in a new combination formulation. Chromatographic separation of the two drugs was achieved on a Hypersil C(18) column using a mobile phase consisting of a binary mixture of methanol and 0.01mol/l sodium acetate (5:95, v/v). The commonly used paired-ion aqueous mobile phase for the determination of penicillins was avoided in this study. The developed LC method offers symmetric peak shape, good resolution and reasonable retention time for both drugs. Linearity, accuracy and precision were found to be acceptable over the concentration ranges of 155.3-1553.0microg/ml for amoxicillin sodium and 45.0-450.0microg/ml for sulbactam sodium. The proposed LC method can be used for the quality control of formulated products containing these two drugs.

Amoxicillin↗
PubMed2004

Identification of cell surface and secreted proteins essential for tumor cell survival using a genetic suppressor element screen.

Survival factors play critical roles in regulating cell growth in normal and cancer cells. We designed a genetic screen to identify survival factors which protect tumor cells from apoptosis. A retroviral expression library of random cDNA fragments was constructed from cancer cells and used to transduce the colon carcinoma cell line HCT116. Recipient cells were functionally selected for induction of caspase 3-mediated apoptosis. Analyses of over 10,000 putative genetic suppression elements (GSEs) sequences revealed cognate gene candidates that are implicated in apoptosis. We further analysed 26 genes encoding cell surface and secreted proteins that can potentially serve as targets for therapeutic antibodies. Tetracycline-inducible GSEs from several gene candidates induced apoptosis in stable HCT 116 cell lines. Similar phenotypes were caused by RNAi derived from the same genes. Our data suggest requirement for the cell surface targets IGF2R, L1CAM and SLC31A1 in tumor cell growth in vitro, and suggests that IGF2R is required for xenograft tumor growth in a mouse model.

Animals↗